PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 2804346-10 1989 The amount of radiolabeled vWF bound to platelets in the presence of either low concentration of ristocetin or asialo vWF was increased 30% compared with normal. Ristocetin 97-107 von Willebrand factor Homo sapiens 27-30 2533412-4 1989 We conclude that in acquired hypothyroidism the lowering of factor VIII:C and vWf:Ag (acquired von Willebrand disease) is associated with impaired platelet reactivity not only to ristocetin but also to collagen and especially adrenalin. Ristocetin 179-189 von Willebrand factor Homo sapiens 78-81 2621801-8 1989 These studies suggest that the abnormality of ristocetin-induced vWF-platelet interaction by IgA RIPA inhibitor and the reduction of all vWF multimers (like type IA von Willebrand disease) may have a relationship with the pathogenesis of bleeding diathesis in this case. Ristocetin 46-56 von Willebrand factor Homo sapiens 65-68 2557900-2 1989 Interaction of von Willebrand factor (vWF) with its platelet receptor only occurs in vitro in the presence of a modulator such as ristocetin. Ristocetin 130-140 von Willebrand factor Homo sapiens 15-36 2557900-2 1989 Interaction of von Willebrand factor (vWF) with its platelet receptor only occurs in vitro in the presence of a modulator such as ristocetin. Ristocetin 130-140 von Willebrand factor Homo sapiens 38-41 2557900-3 1989 We have recently confirmed that the human platelet membrane glycoprotein (GP) Ib-IX complex is the receptor involved in the ristocetin-dependent binding of vWF by reconstitution with the purified components [Berndt, M.C., Du, X., & Booth, W.J. Ristocetin 124-134 von Willebrand factor Homo sapiens 156-159 2557900-10 1989 Botrocetin-dependent binding of vWF was specific, saturable, and comparable to that observed with ristocetin. Ristocetin 98-108 von Willebrand factor Homo sapiens 32-35 2557900-11 1989 An anti-vWF monoclonal antibody, 3F8, inhibited ristocetin- but not botrocetin-dependent binding of vWF, suggesting the presence of distinct ristocetin and botrocetin modulator sites on vWF. Ristocetin 48-58 von Willebrand factor Homo sapiens 8-11 2557900-11 1989 An anti-vWF monoclonal antibody, 3F8, inhibited ristocetin- but not botrocetin-dependent binding of vWF, suggesting the presence of distinct ristocetin and botrocetin modulator sites on vWF. Ristocetin 141-151 von Willebrand factor Homo sapiens 8-11 2508742-4 1989 The functional activity of vWf was assessed by either Ristocetin Cofactor (vWf:RCo) or collagen binding methods (vWf:CBA) with typical vWf:RCo/vWf:Ag ratios ranging from 0.08 to 0.94. Ristocetin 54-64 von Willebrand factor Homo sapiens 27-30 2786916-1 1989 When platelets are stimulated with adenosine diphosphate (ADP), thrombin, or ristocetin, they bind soluble von Willebrand factor (vWF). Ristocetin 77-87 von Willebrand factor Homo sapiens 107-128 2659619-8 1989 The mean plasma vWF value also was significantly elevated initially [vWF antigen, 1.8 +/- 0.7; normal group, 0.9 +/- 0.1 x 10(3) U/L (P less than 0.01); vWF ristocetin cofactor activity, 1.9 +/- 0.9; normal group, 1.0 +/- 0.3 x 10(3) U/L (P less than 0.001)] and decreased significantly after only 1 week of therapy. Ristocetin 157-167 von Willebrand factor Homo sapiens 16-19 2787678-5 1989 More than 50% of the ristocetin cofactor activity was lost during a five-minute incubation of vWF with 0.56 U/mL porcine elastase when no detectable structural changes in the vWF molecule had occurred. Ristocetin 21-31 von Willebrand factor Homo sapiens 94-97 2787678-5 1989 More than 50% of the ristocetin cofactor activity was lost during a five-minute incubation of vWF with 0.56 U/mL porcine elastase when no detectable structural changes in the vWF molecule had occurred. Ristocetin 21-31 von Willebrand factor Homo sapiens 175-178 2786916-1 1989 When platelets are stimulated with adenosine diphosphate (ADP), thrombin, or ristocetin, they bind soluble von Willebrand factor (vWF). Ristocetin 77-87 von Willebrand factor Homo sapiens 130-133 2786916-11 1989 When used to stimulate the platelets, ADP, thrombin, and ristocetin all increased the platelet adhesion to solid-phase vWF. Ristocetin 57-67 von Willebrand factor Homo sapiens 119-122 2786916-16 1989 In addition, these platelets can be stimulated to increase their adherence to vWF by using ADP, thrombin, and ristocetin. Ristocetin 110-120 von Willebrand factor Homo sapiens 78-81 3064358-8 1988 A MAb to vWF (CLB-RAg 35), that inhibits ristocetin induced binding of vWF to platelets, decreased the CCo of normal plasma by 70%. Ristocetin 41-51 von Willebrand factor Homo sapiens 9-12 2657729-4 1989 vWF secreted constitutively by IIB cells into the culture medium bound to platelets at concentrations of ristocetin lower than those necessary for vWF from normal cells. Ristocetin 105-115 von Willebrand factor Homo sapiens 0-3 2657729-5 1989 vWF stored in the Weibel-Palade bodies of type IIB cells was released upon stimulation with phorbol ester and bound almost completely to platelets even in the absence of ristocetin. Ristocetin 170-180 von Willebrand factor Homo sapiens 0-3 2591151-4 1989 Platelet/vWF interaction induced by ristocetin is not enhanced in these cases and the platelet vWF shows the same aberrant multimer pattern as plasma vWF. Ristocetin 36-46 von Willebrand factor Homo sapiens 9-12 3263968-4 1988 Glycocalicin, as well as the 45- and 84-kDa fragments, inhibited the ristocetin-dependent binding of native vWF to platelet GP Ib. Ristocetin 69-79 von Willebrand factor Homo sapiens 108-111 3263968-6 1988 In contrast, the binding of asialo-vWF to platelet GP Ib, measured directly in the absence of ristocetin, was blocked by glycocalicin and the 45-kDa fragment with a similar IC50, but not by the 84-kDa fragment. Ristocetin 94-104 von Willebrand factor Homo sapiens 35-38 3263968-7 1988 Both glycocalicin and the 45-kDa fragment bound to purified surface-bound vWF in a ristocetin-dependent manner and with similar affinities. Ristocetin 83-93 von Willebrand factor Homo sapiens 74-77 3263968-10 1988 Whereas the ristocetin-dependent binding of vWF may involve also other domains in the macroglycopeptide region, the direct vWF-GP Ib interaction appears to be mediated only by a domain in the amino-terminal region of GP Ib alpha. Ristocetin 12-22 von Willebrand factor Homo sapiens 44-47 3264111-7 1988 In eight cases, the platelets of uremic patients were purified, and the thrombin- and ristocetin-induced binding of normal von Willebrand factor to these platelets was examined. Ristocetin 86-96 von Willebrand factor Homo sapiens 123-144 3264111-8 1988 RESULTS: The mean plasma von Willebrand factor antigen and activity (ristocetin cofactor assay) were elevated 2.77 mu/ml and 1.88 mu/ml, respectively (normal, 1.01 mu/ml and 1.07 mu/ml, respectively). Ristocetin 69-79 von Willebrand factor Homo sapiens 25-46 3264111-15 1988 Thrombin and ristocetin-induced binding of normal von Willebrand factor to uremic patients" platelets was indistinguishable from the binding to normal platelets. Ristocetin 13-23 von Willebrand factor Homo sapiens 50-71 3264193-4 1988 In a concentration-dependent manner, ATA also inhibits ristocetin-induced, vWF-mediated platelet clumping in both fresh and formaldehyde-fixed platelet suspensions. Ristocetin 55-65 von Willebrand factor Homo sapiens 75-78 3140912-2 1988 One monoclonal antibody, designated PP3-4C, blocked Ristocetin-induced platelet agglutination and caused 80% inhibition of Ristocetin-induced 125I-von Willebrand factor (vWF) binding to porcine platelets at a concentration of greater than or equal to 12 micrograms IgG/mL. Ristocetin 123-133 von Willebrand factor Homo sapiens 142-168 3140912-2 1988 One monoclonal antibody, designated PP3-4C, blocked Ristocetin-induced platelet agglutination and caused 80% inhibition of Ristocetin-induced 125I-von Willebrand factor (vWF) binding to porcine platelets at a concentration of greater than or equal to 12 micrograms IgG/mL. Ristocetin 123-133 von Willebrand factor Homo sapiens 170-173 3263711-1 1988 Native von Willebrand factor (N-vWF) binds to platelets activated by thrombin, ADP or ristocetin. Ristocetin 86-96 von Willebrand factor Homo sapiens 32-35 3064358-8 1988 A MAb to vWF (CLB-RAg 35), that inhibits ristocetin induced binding of vWF to platelets, decreased the CCo of normal plasma by 70%. Ristocetin 41-51 von Willebrand factor Homo sapiens 71-74 3142084-7 1988 Furthermore, the partial inhibition of CCo by monoclonal antibody CLB-RAg 35 that inhibits the binding of vWF to platelet in the presence of ristocetin, suggests that CCo is partly mediated through platelet membrane glycoprotein Ib. Ristocetin 141-151 von Willebrand factor Homo sapiens 106-109 3413736-5 1988 Furthermore, the von Willebrand factor (vWF) dependent platelet aggregation induced by 0.6 and 1.0 mg/ml ristocetin was clearly diminished after ASA. Ristocetin 105-115 von Willebrand factor Homo sapiens 17-38 3413736-5 1988 Furthermore, the von Willebrand factor (vWF) dependent platelet aggregation induced by 0.6 and 1.0 mg/ml ristocetin was clearly diminished after ASA. Ristocetin 105-115 von Willebrand factor Homo sapiens 40-43 3284916-7 1988 Endothelial cells as well as smooth muscle cells bound 125I-labeled vWF in a ristocetin-dependent manner, with a Kd of 7.9 nM. Ristocetin 77-87 von Willebrand factor Homo sapiens 68-71 2450575-0 1988 Ristocetin-dependent reconstitution of binding of von Willebrand factor to purified human platelet membrane glycoprotein Ib-IX complex. Ristocetin 0-10 von Willebrand factor Homo sapiens 50-71 3128354-3 1988 In 4 patients with type I vWF who were given a Ristocetin cofactor (Rcof) dose of 42-78 U/kg, there was a clear reduction of the bleeding time and an increase of F VIII: C, F VIII: Ag, Rcof and vWF: Ag for several hours. Ristocetin 47-57 von Willebrand factor Homo sapiens 26-29 3128354-3 1988 In 4 patients with type I vWF who were given a Ristocetin cofactor (Rcof) dose of 42-78 U/kg, there was a clear reduction of the bleeding time and an increase of F VIII: C, F VIII: Ag, Rcof and vWF: Ag for several hours. Ristocetin 47-57 von Willebrand factor Homo sapiens 194-197 3126793-4 1988 The inhibitor was able to inhibit the binding of 125I-vWf to platelets in the presence of ristocetin in both cases and to thrombin-stimulated platelets in one case. Ristocetin 90-100 von Willebrand factor Homo sapiens 54-57 3126081-3 1988 In 14 patients with type I vWd characterized by very low plasma levels of factor VIII coagulant activity (VIII:C) and vWf, measured as ristocetin cofactor activity (lower than 20% and 3% of normal respectively), but with a normal intraplatelet content of vWf, a test infusion of DDAVP (0.4 microgram/kg) elicited a very marked increase of VIII:C and vWf and normalized the bleeding time. Ristocetin 135-145 von Willebrand factor Homo sapiens 118-121 3258474-2 1988 Findings typical of type IIB vWD included enhanced ristocetin-induced binding of patient von Willebrand factor (vWF) to platelets of patients and normal individuals in association with the absence of larger multimers from plasma. Ristocetin 51-61 von Willebrand factor Homo sapiens 89-110 3258474-2 1988 Findings typical of type IIB vWD included enhanced ristocetin-induced binding of patient von Willebrand factor (vWF) to platelets of patients and normal individuals in association with the absence of larger multimers from plasma. Ristocetin 51-61 von Willebrand factor Homo sapiens 112-115 2450575-1 1988 Whether the human platelet membrane glycoprotein (GP) Ib-IX complex is the receptor for ristocetin-dependent binding of von Willebrand factor (vWF) has been examined by reconstitution with the purified components using a solid-phase bead assay. Ristocetin 88-98 von Willebrand factor Homo sapiens 120-141 2450575-1 1988 Whether the human platelet membrane glycoprotein (GP) Ib-IX complex is the receptor for ristocetin-dependent binding of von Willebrand factor (vWF) has been examined by reconstitution with the purified components using a solid-phase bead assay. Ristocetin 88-98 von Willebrand factor Homo sapiens 143-146 2450575-3 1988 Specific binding of 125I-labeled vWF to the GP Ib-IX complex coated beads was strictly ristocetin dependent with maximal binding occurring at ristocetin concentrations greater than or equal to 1 mg/mL. Ristocetin 87-97 von Willebrand factor Homo sapiens 33-36 2450575-3 1988 Specific binding of 125I-labeled vWF to the GP Ib-IX complex coated beads was strictly ristocetin dependent with maximal binding occurring at ristocetin concentrations greater than or equal to 1 mg/mL. Ristocetin 142-152 von Willebrand factor Homo sapiens 33-36 2450575-4 1988 Ristocetin-dependent specific binding of 125I-labeled vWF was saturable. Ristocetin 0-10 von Willebrand factor Homo sapiens 54-57 2450575-7 1988 Ristocetin-dependent binding of vWF to platelets and to GP Ib-IX complex coated beads was inhibited by monoclonal antibodies against a 45,000 molecular weight N-terminal region of GP Ib but not by monoclonal antibodies directed against other regions of the GP Ib-IX complex. Ristocetin 0-10 von Willebrand factor Homo sapiens 32-35 2450575-8 1988 Similar correspondence between platelets and purified GP Ib-IX complex with respect to the ristocetin-dependent binding of vWF was obtained with anti-vWF monoclonal antibodies. Ristocetin 91-101 von Willebrand factor Homo sapiens 123-126 2450575-8 1988 Similar correspondence between platelets and purified GP Ib-IX complex with respect to the ristocetin-dependent binding of vWF was obtained with anti-vWF monoclonal antibodies. Ristocetin 91-101 von Willebrand factor Homo sapiens 150-153 3122318-9 1987 Aggregation of washed fixed platelets in the presence of ristocetin or collagen is used for assessment of vWF"s biological activity. Ristocetin 57-67 von Willebrand factor Homo sapiens 106-109 3501312-10 1987 Thus, we deduce that vWF can spontaneously re-multimerize from its reduced subunits and regain a small but measurable quantity of ristocetin co-factor activity. Ristocetin 130-140 von Willebrand factor Homo sapiens 21-24 2822171-8 1987 Ristocetin-induced binding of vWf was inhibited by 6D1, and ADP-induced binding of fibrinogen was inhibited by LJ-CP8. Ristocetin 0-10 von Willebrand factor Homo sapiens 30-33 3116841-6 1987 The ratio of vWF:Ag to ristocetin cofactor was elevated in these patients. Ristocetin 23-33 von Willebrand factor Homo sapiens 13-16 3115333-0 1987 Asialo-von Willebrand factor inhibits platelet adherence to human arterial subendothelium: discrepancy between ristocetin cofactor activity and primary hemostatic function. Ristocetin 111-121 von Willebrand factor Homo sapiens 7-28 3115333-2 1987 Clinically, the ristocetin cofactor (RCof) activity is the only widely available assay for vWF function. Ristocetin 16-26 von Willebrand factor Homo sapiens 91-94 3499929-7 1987 Released vWF contained the higher molecular weight multimers observed in normal endothelial cells, and it possessed ristocetin cofactor activity. Ristocetin 116-126 von Willebrand factor Homo sapiens 9-12 3069641-10 1988 The storage vesicles contain von Willebrand factor that supports ristocetin-induced platelet aggregation. Ristocetin 65-75 von Willebrand factor Homo sapiens 29-50 3502200-0 1987 Calibration of lyophilized standards for ristocetin cofactor activity of von Willebrand Factor (vWF) requires vWF-deficient plasma as diluent for dose-response curves. Ristocetin 41-51 von Willebrand factor Homo sapiens 96-99 3502200-1 1987 Calibration of local standards for ristocetin cofactor activity of von Willebrand"s factor (vWF:Rcof) against reference preparations is required to achieve a better standardization of this measurement. Ristocetin 35-45 von Willebrand factor Homo sapiens 92-95 3500868-2 1987 Ristocetin promotes the binding of vWf to platelet membrane glycoprotein lb, whereas platelet activation by thrombin supports binding to the glycoprotein IIb/IIIa complex. Ristocetin 0-10 von Willebrand factor Homo sapiens 35-38 3500868-6 1987 Modification of vWf amino groups markedly impaired the ability of the protein to support ristocetin-dependent adhesion but did not alter its ability to support thrombin-enhanced adhesion. Ristocetin 89-99 von Willebrand factor Homo sapiens 16-19 3500868-7 1987 Reduction and carboxymethylation nearly abolished the ability of vWf to support adhesion via the ristocetin-dependent mechanism, but did not substantially impair its ability to support thrombin-enhanced adhesion. Ristocetin 97-107 von Willebrand factor Homo sapiens 65-68 2822169-1 1987 We used immunoelectron microscopic localization techniques to investigate whether platelets stimulated by ADP or ristocetin in the plasma milieu bind von Willebrand factor (vWF) to their surfaces. Ristocetin 113-123 von Willebrand factor Homo sapiens 150-171 2822169-1 1987 We used immunoelectron microscopic localization techniques to investigate whether platelets stimulated by ADP or ristocetin in the plasma milieu bind von Willebrand factor (vWF) to their surfaces. Ristocetin 113-123 von Willebrand factor Homo sapiens 173-176 2822169-2 1987 We found by both peroxidase- and ferritin-based methods that unstimulated platelets lack vWF on their surfaces, whereas platelets that are stimulated with ADP or ristocetin have vWF associated with their surfaces. Ristocetin 162-172 von Willebrand factor Homo sapiens 178-181 2822169-5 1987 Thus, in the plasma environment, in the presence of fibrinogen, vWF becomes associated with the platelet surface subsequent to stimulation with ADP or ristocetin. Ristocetin 151-161 von Willebrand factor Homo sapiens 64-67 3127926-4 1987 The PT-PAF activity was dependent on the multimer size of vWf, like in the case of ristocetin cofactor (RCof) activity. Ristocetin 83-93 von Willebrand factor Homo sapiens 58-61 3659809-1 1987 Both von Willebrand factor antigen and activity tested as ristocetin cofactor, were found to be increased in the 20 patients with hyperthyroidism, while changes detected on the 10 hypothyroid patients did not significantly differ from the mean values recorded in 19 healthy control subjects. Ristocetin 58-68 von Willebrand factor Homo sapiens 5-26 3116700-5 1987 The 125I-FVIII/vWF binding to platelets in presence of ristocetin is totally inhibited by low 211 A6 concentrations. Ristocetin 55-65 von Willebrand factor Homo sapiens 15-18 3116700-8 1987 The complete inhibition of platelet adhesion by 211 A6 questions the similarity or the interrelationship in vWF domains involved in ristocetin-induced platelet functions and platelet adhesion. Ristocetin 132-142 von Willebrand factor Homo sapiens 108-111 3116700-0 1987 Characterisation of a monoclonal antibody to von Willebrand factor as a potent inhibitor of ristocetin-mediated platelet interaction and platelet adhesion. Ristocetin 92-102 von Willebrand factor Homo sapiens 45-66 2946332-2 1986 The addition of 4.5 X 10(-7) mol/L plasmin to washed platelets caused a time-dependent decrease in ristocetin-induced, vWF-dependent platelet agglutination. Ristocetin 99-109 von Willebrand factor Homo sapiens 119-122 3101558-6 1987 Of the other 30 patients, a mild increase in ristocetin cofactor/vWF:Ag was seen in only 2 with secondary pulmonary hypertension and 1 with normal pulmonary artery pressure: these also had an abnormal vWF multimer pattern that was different from that observed in patients with primary pulmonary hypertension. Ristocetin 45-55 von Willebrand factor Homo sapiens 201-204 3492222-4 1987 A blood sample was taken from each subject for determination of the blood group and von Willebrand factor (vWf) level (measured as ristocetin cofactor and expressed in IU/dL after calibration of the internal pool against an international standard), and the parents were given a questionnaire concerning hemorrhagic symptoms in the members of the family in the last three generations. Ristocetin 131-141 von Willebrand factor Homo sapiens 74-105 3492222-4 1987 A blood sample was taken from each subject for determination of the blood group and von Willebrand factor (vWf) level (measured as ristocetin cofactor and expressed in IU/dL after calibration of the internal pool against an international standard), and the parents were given a questionnaire concerning hemorrhagic symptoms in the members of the family in the last three generations. Ristocetin 131-141 von Willebrand factor Homo sapiens 107-110 3123334-4 1987 We found that a commercially available factor VIII/vWf concentrate, Haemate P, contained the high-molecular-weight multimers of vWf and had a ratio of ristocetin cofactor (RCof) to vWf antigen (vWf:Ag) close to unity. Ristocetin 151-161 von Willebrand factor Homo sapiens 51-54 3492062-0 1986 A paradoxical effect of antibody concentration on vWF-dependent platelet agglutination distinguishes between botrocetin and ristocetin-induced agglutination. Ristocetin 124-134 von Willebrand factor Homo sapiens 50-53 3111088-0 1987 Assessment of multimeric structure and ristocetin-induced binding to platelets of von Willebrand factor present in cryoprecipitate and different factor VIII concentrates. Ristocetin 39-49 von Willebrand factor Homo sapiens 82-103 3492062-7 1986 Antisera to human vWF that showed this paradoxical inhibitory/enhancing effect on botrocetin-induced agglutination also inhibited ristocetin-induced platelet agglutination at high concentrations, but failed to enhance agglutination at any concentration. Ristocetin 130-140 von Willebrand factor Homo sapiens 18-21 3551182-1 1986 Previously we have studied the binding domains on von Willebrand factor (vWF) involved in ristocetin-induced binding to platelets (ristocetin binding domain, RBD) and in the binding of vWF to collagen (collagen binding domain, CBD) using tryptic fragments of 125I-labelled vWF (21, 23). Ristocetin 90-100 von Willebrand factor Homo sapiens 50-71 3551182-1 1986 Previously we have studied the binding domains on von Willebrand factor (vWF) involved in ristocetin-induced binding to platelets (ristocetin binding domain, RBD) and in the binding of vWF to collagen (collagen binding domain, CBD) using tryptic fragments of 125I-labelled vWF (21, 23). Ristocetin 90-100 von Willebrand factor Homo sapiens 73-76 3551182-1 1986 Previously we have studied the binding domains on von Willebrand factor (vWF) involved in ristocetin-induced binding to platelets (ristocetin binding domain, RBD) and in the binding of vWF to collagen (collagen binding domain, CBD) using tryptic fragments of 125I-labelled vWF (21, 23). Ristocetin 131-141 von Willebrand factor Homo sapiens 50-71 3551182-1 1986 Previously we have studied the binding domains on von Willebrand factor (vWF) involved in ristocetin-induced binding to platelets (ristocetin binding domain, RBD) and in the binding of vWF to collagen (collagen binding domain, CBD) using tryptic fragments of 125I-labelled vWF (21, 23). Ristocetin 131-141 von Willebrand factor Homo sapiens 73-76 3101223-6 1986 The adhesion of FWP was inhibited by fibronectin (FN) and the binding of ristocetin cofactor (vWF:RCo) to collagen fiber was also inhibited by FN; bound vWF:RCo to 50 micrograms/ml collagen in the absence or presence of 125 micrograms/ml FN were 60% and 8% respectively. Ristocetin 73-83 von Willebrand factor Homo sapiens 94-97 3101223-6 1986 The adhesion of FWP was inhibited by fibronectin (FN) and the binding of ristocetin cofactor (vWF:RCo) to collagen fiber was also inhibited by FN; bound vWF:RCo to 50 micrograms/ml collagen in the absence or presence of 125 micrograms/ml FN were 60% and 8% respectively. Ristocetin 73-83 von Willebrand factor Homo sapiens 153-156 3097817-3 1986 Activities of vWf in plasmas of 51 patients were measured with either collagen (ColCof) or ristocetin (RCof). Ristocetin 91-101 von Willebrand factor Homo sapiens 14-17 3489493-2 1986 The binding of vWF to platelets was mediated and regulated by ristocetin. Ristocetin 62-72 von Willebrand factor Homo sapiens 15-18 3489493-9 1986 With addition of vWF to this PRP an enhanced response was observed at a ristocetin concentration inversely proportional to the vWF level. Ristocetin 72-82 von Willebrand factor Homo sapiens 17-20 3489493-9 1986 With addition of vWF to this PRP an enhanced response was observed at a ristocetin concentration inversely proportional to the vWF level. Ristocetin 72-82 von Willebrand factor Homo sapiens 127-130 3489493-14 1986 A dose-response 125I-vWF-platelet binding occurred with increasing ristocetin concentrations which was unchanged by the addition of collagen. Ristocetin 67-77 von Willebrand factor Homo sapiens 21-24 3489493-16 1986 The in vitro-enhanced CIPA represents a vWF-dependent aggregation of sufficient magnitude to overcome the inhibitory effect of ristocetin. Ristocetin 127-137 von Willebrand factor Homo sapiens 40-43 3092393-3 1986 The level of ristocetin cofactor activity of vWF was between 70 and 144% in the control group. Ristocetin 13-23 von Willebrand factor Homo sapiens 45-48 3487353-4 1986 Addition of ristocetin to the patients" platelet-rich plasma resulted in the removal of vWF (and, more selectively, of the large multimers) at lower concentrations of ristocetin than normal, as in type IIB and pseudo-vWD. Ristocetin 12-22 von Willebrand factor Homo sapiens 88-91 3487353-5 1986 The defect in the patients was localized to their vWF, which had an enhanced capacity for aggregating washed normal platelets in the presence of low concentrations of ristocetin and for aggregating pseudo-vWD platelets (in the absence of ristocetin). Ristocetin 167-177 von Willebrand factor Homo sapiens 50-53 3487353-5 1986 The defect in the patients was localized to their vWF, which had an enhanced capacity for aggregating washed normal platelets in the presence of low concentrations of ristocetin and for aggregating pseudo-vWD platelets (in the absence of ristocetin). Ristocetin 238-248 von Willebrand factor Homo sapiens 50-53 3487975-6 1986 In four patients with abnormal ristocetin-induced aggregation, vWF:Ag, RCoF, and FVIII:C were all reduced. Ristocetin 31-41 von Willebrand factor Homo sapiens 63-66 3092393-5 1986 The vWF:Ag level closely paralleled the rise of ristocetin cofactor activity of vWF, with a peak of 336% on day 5. Ristocetin 48-58 von Willebrand factor Homo sapiens 4-7 3092393-5 1986 The vWF:Ag level closely paralleled the rise of ristocetin cofactor activity of vWF, with a peak of 336% on day 5. Ristocetin 48-58 von Willebrand factor Homo sapiens 80-83 3092393-8 1986 The ristocetin cofactor activity of vWF and vWF:Ag thus are sensitive biochemical indicators for recent AMI, and may serve as useful markers for up to 14 days following infarction, when the traditional enzymes have returned to normal levels. Ristocetin 4-14 von Willebrand factor Homo sapiens 36-39 3092393-8 1986 The ristocetin cofactor activity of vWF and vWF:Ag thus are sensitive biochemical indicators for recent AMI, and may serve as useful markers for up to 14 days following infarction, when the traditional enzymes have returned to normal levels. Ristocetin 4-14 von Willebrand factor Homo sapiens 44-47 3000477-3 1986 The binding to platelets of 6D1, a monoclonal antibody that recognizes an epitope on GpIb and blocks ristocetin-induced vWF binding to platelets, was inhibited by purified GC. Ristocetin 101-111 von Willebrand factor Homo sapiens 120-123 3008890-2 1986 SpII (215 kd) and SpIII (320 kd), the S aureus V-8 protease homodimeric fragments representing the carboxy-terminal and amino-terminal segments of the vWF subunit, competitively inhibited the binding of multimeric vWF to thrombin-stimulated or ristocetin-stimulated platelets, respectively. Ristocetin 244-254 von Willebrand factor Homo sapiens 151-154 3008890-7 1986 In contrast, M Ab H9, which blocks ristocetin-induced binding of vWF to platelets, inhibited binding of SpIII to platelets and bound to SpIII as well as to monomeric 33-kd and 28-kd subtilisin fragments. Ristocetin 35-45 von Willebrand factor Homo sapiens 65-68 3003157-7 1986 Complex formation was blocked by rabbit antiglycocalicin antiserum, but not by the monoclonal antibody 6D1, which is directed against the site on GPIb where von Willebrand factor (vWf) binds in the presence of ristocetin. Ristocetin 210-220 von Willebrand factor Homo sapiens 157-178 3003157-7 1986 Complex formation was blocked by rabbit antiglycocalicin antiserum, but not by the monoclonal antibody 6D1, which is directed against the site on GPIb where von Willebrand factor (vWf) binds in the presence of ristocetin. Ristocetin 210-220 von Willebrand factor Homo sapiens 180-183 3486014-0 1986 Identification of functional domains on von Willebrand factor by binding of tryptic fragments to collagen and to platelets in the presence of ristocetin. Ristocetin 142-152 von Willebrand factor Homo sapiens 40-61 3486014-1 1986 With the use of monoclonal antibodies that inhibit the ristocetin-induced binding of von Willebrand factor (VWF) to platelets and the binding to collagen, we have previously identified two distinct tryptic fragments. Ristocetin 55-65 von Willebrand factor Homo sapiens 85-106 3486014-1 1986 With the use of monoclonal antibodies that inhibit the ristocetin-induced binding of von Willebrand factor (VWF) to platelets and the binding to collagen, we have previously identified two distinct tryptic fragments. Ristocetin 55-65 von Willebrand factor Homo sapiens 108-111 3484979-3 1986 Analysis of the factor VIII molecular complex revealed that six patients had reduced vWF measured both immunologically (vW:Ag) and by ristocetin cofactor assay (vW:rist). Ristocetin 134-144 von Willebrand factor Homo sapiens 85-88 2934387-3 1986 After extensive treatment with denaturants, the 52/48-kDa polypeptide retained its ability to inhibit ristocetin-induced platelet aggregation in the presence of native vWF, as well as aggregation induced by desialylated vWF alone. Ristocetin 102-112 von Willebrand factor Homo sapiens 168-171 2934387-3 1986 After extensive treatment with denaturants, the 52/48-kDa polypeptide retained its ability to inhibit ristocetin-induced platelet aggregation in the presence of native vWF, as well as aggregation induced by desialylated vWF alone. Ristocetin 102-112 von Willebrand factor Homo sapiens 220-223 2435633-12 1986 Von Willebrand factor activity, expressed as its ability to induce platelet aggregation in the presence of the antibiotic Ristocetin, can be carried out using normal formalin fixed platelets, either with aggregometer or visual methods (glass slide test or tubes test and microtritation plate). Ristocetin 122-132 von Willebrand factor Homo sapiens 0-21 3000477-4 1986 In addition, purified GC inhibited ristocetin-dependent binding of 125I-labeled vWF to platelets. Ristocetin 35-45 von Willebrand factor Homo sapiens 80-83 3917314-1 1985 A monoclonal antibody directed against the von Willebrand factor moiety (vWF) of factor VIII-von Willebrand factor (FVIII-vWF), which blocks ristocetin-induced platelet aggregation as well as the binding of FVIII-vWF to platelets in the presence of ristocetin, inhibited platelet adherence to human artery subendothelium when present in normal flowing blood. Ristocetin 141-151 von Willebrand factor Homo sapiens 73-76 3927998-8 1985 The Ab was unable to bind isolated FVIII:C. The combined use of the new vWF-binding assay and a battery of tests for inhibition of vWF-dependent platelet aggregation with ristocetin (which detects high molecular weight vWF), with botrocetin (which detects high and low molecular weight vWF), and with platelet-aggregating factor (which detects high molecular weight vWF) provided a means of analysis of Ab effect on in vitro vWF function. Ristocetin 171-181 von Willebrand factor Homo sapiens 131-134 3927998-8 1985 The Ab was unable to bind isolated FVIII:C. The combined use of the new vWF-binding assay and a battery of tests for inhibition of vWF-dependent platelet aggregation with ristocetin (which detects high molecular weight vWF), with botrocetin (which detects high and low molecular weight vWF), and with platelet-aggregating factor (which detects high molecular weight vWF) provided a means of analysis of Ab effect on in vitro vWF function. Ristocetin 171-181 von Willebrand factor Homo sapiens 131-134 3927998-8 1985 The Ab was unable to bind isolated FVIII:C. The combined use of the new vWF-binding assay and a battery of tests for inhibition of vWF-dependent platelet aggregation with ristocetin (which detects high molecular weight vWF), with botrocetin (which detects high and low molecular weight vWF), and with platelet-aggregating factor (which detects high molecular weight vWF) provided a means of analysis of Ab effect on in vitro vWF function. Ristocetin 171-181 von Willebrand factor Homo sapiens 131-134 3927998-8 1985 The Ab was unable to bind isolated FVIII:C. The combined use of the new vWF-binding assay and a battery of tests for inhibition of vWF-dependent platelet aggregation with ristocetin (which detects high molecular weight vWF), with botrocetin (which detects high and low molecular weight vWF), and with platelet-aggregating factor (which detects high molecular weight vWF) provided a means of analysis of Ab effect on in vitro vWF function. Ristocetin 171-181 von Willebrand factor Homo sapiens 131-134 3927998-8 1985 The Ab was unable to bind isolated FVIII:C. The combined use of the new vWF-binding assay and a battery of tests for inhibition of vWF-dependent platelet aggregation with ristocetin (which detects high molecular weight vWF), with botrocetin (which detects high and low molecular weight vWF), and with platelet-aggregating factor (which detects high molecular weight vWF) provided a means of analysis of Ab effect on in vitro vWF function. Ristocetin 171-181 von Willebrand factor Homo sapiens 131-134 3927998-12 1985 The findings indicate that the vWS Ab binds to an epitope on the molecular vWF in such a way that causes only limited inhibition of vWF/ristocetin function and no inhibition of vWF/botrocetin function, suggesting that these two functional domains are at separate sites. Ristocetin 136-146 von Willebrand factor Homo sapiens 75-78 3878608-4 1985 Binding of two distinct antibodies at one of these epitopes was associated with enhancement of the rate of vWf-dependent platelet agglutination in the presence of ristocetin. Ristocetin 163-173 von Willebrand factor Homo sapiens 107-110 2414486-0 1985 [Studies on the effects of five monoclonal antibodies, polyclonal rabbit antibody and homologous antibody to human F VIII/vWF on ristocetin-induced platelet agglutination and platelet retention by glass bead column]. Ristocetin 129-139 von Willebrand factor Homo sapiens 122-125 2580547-2 1985 This antibody is a potent inhibitor of von Willebrand factor activity (VIII:vWF) in that it can totally neutralize ristocetin-induced aggregation of platelet rich plasma and inhibit platelet adhesion at high flow rates. Ristocetin 115-125 von Willebrand factor Homo sapiens 76-79 2580547-5 1985 Results obtained in these patients showed a high degree of correlation between the monoclonally-defined epitope and VIII:vWF levels measured by ristocetin-induced aggregation of washed platelets. Ristocetin 144-154 von Willebrand factor Homo sapiens 121-124 3918560-7 1985 The data derived from our study imply that perfusion experiments with reconstituted blood offer a new approach in characterization of these patients, which may be more relevant for the treatment of the patients than characterization by ristocetin induced adsorption of FVIII-VWF to platelets. Ristocetin 236-246 von Willebrand factor Homo sapiens 275-278 3876857-6 1985 Therefore, it is concluded that vWF is unlikely to play a major role in platelet aggregation induced by majority of TTP plasmas and that the site of platelet GP Ib, to which vWF binds in the presence of ristocetin, is not involved in TTP plasma-induced aggregation. Ristocetin 203-213 von Willebrand factor Homo sapiens 174-177 2932740-3 1985 Ristocetin-induced platelet aggregation was enhanced by purified IIB vWF. Ristocetin 0-10 von Willebrand factor Homo sapiens 69-72 2932740-4 1985 The aggregation of washed normal platelets mixed with IIB vWF (0.4 microgram/ml) required lower amounts of ristocetin than the aggregation of normal platelets mixed with the same concentrations of normal vWF. Ristocetin 107-117 von Willebrand factor Homo sapiens 58-61 2931492-2 1985 Isolated washed patient platelets bound more FVIII/vWF at high (1 and 0.75 mg/ml) and low (0.5 and 0.25 mg/ml) ristocetin concentrations than control platelets. Ristocetin 111-121 von Willebrand factor Homo sapiens 51-54 3936216-3 1985 Small molecular forms of FVIII/vWF from normal and variant type II plasma, and those derived by disulfide reduction of high-molecular weight FVIII/vWF, showed remarkably decreased reactivity in ristocetin-, botrocetin- and latex-assay. Ristocetin 194-204 von Willebrand factor Homo sapiens 31-34 3936216-3 1985 Small molecular forms of FVIII/vWF from normal and variant type II plasma, and those derived by disulfide reduction of high-molecular weight FVIII/vWF, showed remarkably decreased reactivity in ristocetin-, botrocetin- and latex-assay. Ristocetin 194-204 von Willebrand factor Homo sapiens 147-150 2864750-1 1985 This study compares the ability of unmodified and carbohydrate-modified forms of factor VIII/von Willebrand factor (FVIII/vWF) protein to bind to platelets in the presence of ristocetin or thrombin. Ristocetin 175-185 von Willebrand factor Homo sapiens 122-125 3155489-6 1985 Plasmin, 0.05 to 1.0 CU/mL, reduced ristocetin-mediated agglutination of washed platelets in the presence of von Willebrand factor (vWF) from 66% of control to 2% of control, following a one-hour incubation. Ristocetin 36-46 von Willebrand factor Homo sapiens 109-130 3155489-6 1985 Plasmin, 0.05 to 1.0 CU/mL, reduced ristocetin-mediated agglutination of washed platelets in the presence of von Willebrand factor (vWF) from 66% of control to 2% of control, following a one-hour incubation. Ristocetin 36-46 von Willebrand factor Homo sapiens 132-135 6241752-3 1984 In the presence of a small amount of normal vWF, ristocetin-induced agglutination of patient platelets was enhanced with low concentrations of ristocetin. Ristocetin 49-59 von Willebrand factor Homo sapiens 44-47 6241752-3 1984 In the presence of a small amount of normal vWF, ristocetin-induced agglutination of patient platelets was enhanced with low concentrations of ristocetin. Ristocetin 143-153 von Willebrand factor Homo sapiens 44-47 6440307-1 1984 Ristocetin, protamine and Polybrene promote factor VIII:vWF binding and agglutination of formalinized platelets. Ristocetin 0-10 von Willebrand factor Homo sapiens 56-59 6438823-2 1984 Limited reduction of disulfide bonds in this complex by NADPH, thioredoxin reductase and thioredoxin leads to partial disaggregation of the multimeric VIII:vWF with concomitant loss of its platelet agglutinating activity in the presence of ristocetin, and with dissociation of factor VIII:C from the complex. Ristocetin 240-250 von Willebrand factor Homo sapiens 156-159 6332119-4 1984 CLB-RAg 35 also inhibited the ristocetin-induced platelet aggregation and the binding of FVIII-VWF to the platelet in the presence of ristocetin but did not affect the binding of FVIII-VWF to collagen. Ristocetin 134-144 von Willebrand factor Homo sapiens 95-98 6239876-1 1984 To better define the role of carbohydrate in the structure and ristocetin cofactor activity of von Willebrand factor, we have removed up to 83% of total hexose by sequential treatment of the molecule with endo-beta-N-acetyl-glucosaminidase F (endo F), neuraminidase, and beta-galactosidase. Ristocetin 63-73 von Willebrand factor Homo sapiens 95-116 6239876-7 1984 Further treatment of von Willebrand factor with neuraminidase and beta-galactosidase reduced the D-galactose to 15% and ristocetin cofactor activity to 57%. Ristocetin 120-130 von Willebrand factor Homo sapiens 21-42 6239876-8 1984 A similar decrease in ristocetin cofactor activity was seen if von Willebrand factor was treated only with neuraminidase and beta-galactosidase. Ristocetin 22-32 von Willebrand factor Homo sapiens 63-84 6435280-6 1984 The combined results suggest that as well as the ristocetin-dependent, divalent cation-independent binding of FVIII/vWF to glycoprotein Ib, there is a divalent cation-dependent binding of FVIII/vWF to the activated platelet surface which is mediated via the glycoprotein IIb/IIIa complex. Ristocetin 49-59 von Willebrand factor Homo sapiens 116-119 6204681-10 1984 When these conclusions are considered within the context of a spatial map of the vWF protein surface developed by competitive displacement analysis, the epitopes related to platelet adhesion appear to be spaced and differ from those involved in ristocetin-induced platelet-platelet interaction. Ristocetin 245-255 von Willebrand factor Homo sapiens 81-84 3917314-1 1985 A monoclonal antibody directed against the von Willebrand factor moiety (vWF) of factor VIII-von Willebrand factor (FVIII-vWF), which blocks ristocetin-induced platelet aggregation as well as the binding of FVIII-vWF to platelets in the presence of ristocetin, inhibited platelet adherence to human artery subendothelium when present in normal flowing blood. Ristocetin 141-151 von Willebrand factor Homo sapiens 43-64 3917314-1 1985 A monoclonal antibody directed against the von Willebrand factor moiety (vWF) of factor VIII-von Willebrand factor (FVIII-vWF), which blocks ristocetin-induced platelet aggregation as well as the binding of FVIII-vWF to platelets in the presence of ristocetin, inhibited platelet adherence to human artery subendothelium when present in normal flowing blood. Ristocetin 141-151 von Willebrand factor Homo sapiens 122-125 3917314-1 1985 A monoclonal antibody directed against the von Willebrand factor moiety (vWF) of factor VIII-von Willebrand factor (FVIII-vWF), which blocks ristocetin-induced platelet aggregation as well as the binding of FVIII-vWF to platelets in the presence of ristocetin, inhibited platelet adherence to human artery subendothelium when present in normal flowing blood. Ristocetin 141-151 von Willebrand factor Homo sapiens 122-125 3917314-1 1985 A monoclonal antibody directed against the von Willebrand factor moiety (vWF) of factor VIII-von Willebrand factor (FVIII-vWF), which blocks ristocetin-induced platelet aggregation as well as the binding of FVIII-vWF to platelets in the presence of ristocetin, inhibited platelet adherence to human artery subendothelium when present in normal flowing blood. Ristocetin 249-259 von Willebrand factor Homo sapiens 73-76 3917314-1 1985 A monoclonal antibody directed against the von Willebrand factor moiety (vWF) of factor VIII-von Willebrand factor (FVIII-vWF), which blocks ristocetin-induced platelet aggregation as well as the binding of FVIII-vWF to platelets in the presence of ristocetin, inhibited platelet adherence to human artery subendothelium when present in normal flowing blood. Ristocetin 249-259 von Willebrand factor Homo sapiens 43-64 3917314-1 1985 A monoclonal antibody directed against the von Willebrand factor moiety (vWF) of factor VIII-von Willebrand factor (FVIII-vWF), which blocks ristocetin-induced platelet aggregation as well as the binding of FVIII-vWF to platelets in the presence of ristocetin, inhibited platelet adherence to human artery subendothelium when present in normal flowing blood. Ristocetin 249-259 von Willebrand factor Homo sapiens 122-125 3917314-1 1985 A monoclonal antibody directed against the von Willebrand factor moiety (vWF) of factor VIII-von Willebrand factor (FVIII-vWF), which blocks ristocetin-induced platelet aggregation as well as the binding of FVIII-vWF to platelets in the presence of ristocetin, inhibited platelet adherence to human artery subendothelium when present in normal flowing blood. Ristocetin 249-259 von Willebrand factor Homo sapiens 122-125 6324004-3 1984 Two apparently distinct mechanisms have now been identified for enhancing 125I-vWF interaction with stimulated platelets: one is induced by ristocetin and apparently mediated by platelet membrane glycoprotein Ib (GPIb); a second mechanism has been identified more recently and is induced by the physiological stimuli ADP and thrombin. Ristocetin 140-150 von Willebrand factor Homo sapiens 79-82 6087354-9 1984 A synthetic dodecapeptide (Mr, 1188), analogous with the specific platelet receptor recognition site of human fibrinogen gamma chain (gamma 400-411), inhibited binding of both 125I-labeled vWF and 125I-labeled fibrinogen to ADP-treated platelets, whereas it was without effect on binding of 125I-labeled vWF to ristocetin-treated platelets. Ristocetin 311-321 von Willebrand factor Homo sapiens 189-192 6426553-1 1984 We have studied the role of factor VIII-von Willebrand factor (FVIII-vWF) in both platelet adherence to subendothelium and ristocetin-induced platelet aggregation using monoclonal antibodies to human FVIII-vWF. Ristocetin 123-133 von Willebrand factor Homo sapiens 69-72 6426553-7 1984 These results demonstrate that a domain is present on the FVIII-vWF molecule that is associated both with ristocetin-induced aggregation and with the ability of FVIII-vWF to support platelet adherence to the subendothelium. Ristocetin 106-116 von Willebrand factor Homo sapiens 64-67 6426553-7 1984 These results demonstrate that a domain is present on the FVIII-vWF molecule that is associated both with ristocetin-induced aggregation and with the ability of FVIII-vWF to support platelet adherence to the subendothelium. Ristocetin 106-116 von Willebrand factor Homo sapiens 167-170 6426553-8 1984 Based on these observations, it is concluded that ristocetin-induced binding of FVIII-vWF to platelets reflects, at least in part, a physiologic mechanism regulating the function of FVIII-vWF in primary hemostasis. Ristocetin 50-60 von Willebrand factor Homo sapiens 86-89 6426553-8 1984 Based on these observations, it is concluded that ristocetin-induced binding of FVIII-vWF to platelets reflects, at least in part, a physiologic mechanism regulating the function of FVIII-vWF in primary hemostasis. Ristocetin 50-60 von Willebrand factor Homo sapiens 188-191 6424741-5 1984 Pretreatment of FVIII-vWF with the calcium chelator EGTA (10 mM) resulted in loss of the ability to facilitate platelet adherence, while the ristocetin cofactor activity remained intact. Ristocetin 141-151 von Willebrand factor Homo sapiens 22-25 6607757-2 1984 The amount of functional vWF activity was assessed by ristocetin-induced platelet aggregation and by a radioreceptor platelet assay. Ristocetin 54-64 von Willebrand factor Homo sapiens 25-28 6232731-4 1984 However, in the presence of 0.75 mg/ml ristocetin, added vWF (2.9 micrograms/ml) caused a further 6.3 +/- 3.8% decrease in control platelet EPM, but caused no significant decrease in the enzyme-treated platelets (p less than 0.05). Ristocetin 39-49 von Willebrand factor Homo sapiens 57-60 6232731-5 1984 In the presence of 0.3 mg/ml ristocetin, added vWF (2.9-14.5 micrograms/ml) caused a small but significant decrease in control platelet EPM, but caused no significant decrease in the enzyme-treated platelets. Ristocetin 29-39 von Willebrand factor Homo sapiens 47-50 6971912-1 1981 A patient with a reduced response to the platelet-aggregating agent ristocetin and a prolonged bleeding time was found to have an abnormally high level of vWf as measured by Laurell immunoelectrophoresis. Ristocetin 68-78 von Willebrand factor Homo sapiens 155-158 6084622-3 1984 Both monoclonal antibodies are capable of inhibiting strongly the FVIII.vWF associated ristocetin cofactor activity. Ristocetin 87-97 von Willebrand factor Homo sapiens 72-75 6419373-1 1983 Human Factor VIII associated von Willebrand factor (VIII:vWF) binds to human platelets in vitro only in the presence of a mediator such as ristocetin, thrombin or ADP. Ristocetin 139-149 von Willebrand factor Homo sapiens 57-60 6752879-16 1982 The ristocetin-induced platelet membrane receptor for vWF seems to be glycoprotein Ib, platelet adhesion being also abnormal in Giant Platelet Syndrome. Ristocetin 4-14 von Willebrand factor Homo sapiens 54-57 6752879-17 1982 The in vivo counterpart for ristocetin is unknown, but it is possible that collagen, microfibrils, thrombin (which also induces the platelet receptor for vWF or sialidases (asialo-human vWF is able to directly bind to the platelet membrane) could replace ristocetin. Ristocetin 255-265 von Willebrand factor Homo sapiens 186-189 6307433-1 1983 It is known that the antibiotic ristocetin exposes the platelet membrane receptor for factor VIII/von Willebrand glycoprotein (FVIII/vWF). Ristocetin 32-42 von Willebrand factor Homo sapiens 133-136 6307433-5 1983 With ristocetin present, the amount of 125I-FVIII/vWF that became platelet-bound correlated closely with the onset, rate, and extent of platelet aggregation. Ristocetin 5-15 von Willebrand factor Homo sapiens 50-53 6307433-6 1983 In contrast, at every thrombin concentration tested, the amount of 125I-FVIII/vWF that specifically bound to platelets was about 6% of that observed with ristocetin. Ristocetin 154-164 von Willebrand factor Homo sapiens 78-81 7164028-0 1982 Binding of porcine von Willebrand factor to human platelets in the presence of ristocetin. Ristocetin 79-89 von Willebrand factor Homo sapiens 19-40 7164028-1 1982 The interaction of porcine von Willebrand factor (vWF) with human platelets in the presence of ristocetin was examined. Ristocetin 95-105 von Willebrand factor Homo sapiens 27-48 7164028-1 1982 The interaction of porcine von Willebrand factor (vWF) with human platelets in the presence of ristocetin was examined. Ristocetin 95-105 von Willebrand factor Homo sapiens 50-53 7164028-3 1982 Assuming vWF to be a tetramer with a MW of 9.5 x 10(5), approximately 94,000 vWF binding sites per platelet were found with an average binding constant of 2.1 x 10(-8)M. Human vWF competed with the porcine protein for this site only in the presence of ristocetin. Ristocetin 252-262 von Willebrand factor Homo sapiens 9-12 6797459-8 1981 The binding of factor VIII/von Willebrand factor to platelet membrane in the presence of ristocetin was decreased in the binding site for factor VIII/von Willebrand factor to allow platelet adhesion to subendothelium. Ristocetin 89-99 von Willebrand factor Homo sapiens 27-48 6797459-8 1981 The binding of factor VIII/von Willebrand factor to platelet membrane in the presence of ristocetin was decreased in the binding site for factor VIII/von Willebrand factor to allow platelet adhesion to subendothelium. Ristocetin 89-99 von Willebrand factor Homo sapiens 150-171 6797089-3 1981 We have studied the in vitro effects of ticlopidine on fibrinogen binding induced by ADP and adrenaline as well as factor VIII/vWF binding induced by ristocetin. Ristocetin 150-160 von Willebrand factor Homo sapiens 127-130 6797089-5 1981 The binding of 125I-factor VIII/vWF in the presence of 1 mg/ml ristocetin was measured in both washed and paraformaldehyde-fixed platelets. Ristocetin 63-73 von Willebrand factor Homo sapiens 32-35 6779399-4 1980 When the same platelets were suspended in human plasma and ristocetin or collagen was added, more clumps were formed and more vWF (human) was associated with these clumps. Ristocetin 59-69 von Willebrand factor Homo sapiens 126-129 1086910-6 1976 The bleeding-time corrective factor and the ristocetin-related vWF or platelet-aggregating factor are dissociable, distinct activites. Ristocetin 44-54 von Willebrand factor Homo sapiens 63-66 6773982-11 1980 In subtype IIB, binding of factor VIII/von Willebrand factor to platelets occurred at lower concentrations of ristocetin than required for normal and multimers of smaller size than in normal bound. Ristocetin 110-120 von Willebrand factor Homo sapiens 39-60 6767976-2 1980 We have now identified 20 persons from five families whose qualitatively abnormal FVIII/vWF shows heightened responsiveness to ristocetin. Ristocetin 127-137 von Willebrand factor Homo sapiens 88-91 6767976-3 1980 We have classified this form of the disease as Type IIB and reclassified as Type IIA the form previously described as Type II, in which the interaction of the abnormal FVIII/vWF with platelets is decreased or absent in the presence of ristocetin. Ristocetin 235-245 von Willebrand factor Homo sapiens 174-177 6767976-4 1980 The enhanced reactivity of FVIII/vWF in Type IIB was evident in studies of ristocetin-induced platelet agglutination and of binding of FVIII/vWF to platelets in the presence of ristocetin. Ristocetin 75-85 von Willebrand factor Homo sapiens 33-36 6767976-4 1980 The enhanced reactivity of FVIII/vWF in Type IIB was evident in studies of ristocetin-induced platelet agglutination and of binding of FVIII/vWF to platelets in the presence of ristocetin. Ristocetin 177-187 von Willebrand factor Homo sapiens 33-36 6965350-4 1980 However, binding was highly dependent on ristocetin concentration, as the number of human factor VIII/von Willebrand factor molecules bound per platelet was a function of the ristocetin concentration. Ristocetin 41-51 von Willebrand factor Homo sapiens 102-123 6965350-4 1980 However, binding was highly dependent on ristocetin concentration, as the number of human factor VIII/von Willebrand factor molecules bound per platelet was a function of the ristocetin concentration. Ristocetin 175-185 von Willebrand factor Homo sapiens 102-123 6965350-5 1980 At a ristocetin concentration of 0.55 mg/ml, each platelet binds approximately 11,000 factor VIII/von Willebrand factor molecules per platelet. Ristocetin 5-15 von Willebrand factor Homo sapiens 98-119 6965350-8 1980 As with ristocetin-induced platelet agglutination, the carbohydrate content plays a significant role in the binding of the factor VIII/von Willebrand factor protein to the platelet. Ristocetin 8-18 von Willebrand factor Homo sapiens 135-156 317771-0 1979 von Willebrand factor: characterization of interaction among von Willebrand factor, ristocetin and platelet. Ristocetin 84-94 von Willebrand factor Homo sapiens 0-21 315561-4 1979 Our results demonstrate a highly significant linear correlation between the degree of FVIII/vWF receptor binding and the extent of ristocetin-induced platelet aggregation. Ristocetin 131-141 von Willebrand factor Homo sapiens 92-95 739056-3 1978 The most striking difference was a reduced or absent ristocetin-induced platelet aggregation in Nigerian platelet-rich plasma, probably due to a plasma component interacting with the von Willebrand activity (VWF), since factor VIII coagulant activity, factor VIII related antigen, and isolated VWF were normal or high by European standards. Ristocetin 53-63 von Willebrand factor Homo sapiens 208-211 739056-3 1978 The most striking difference was a reduced or absent ristocetin-induced platelet aggregation in Nigerian platelet-rich plasma, probably due to a plasma component interacting with the von Willebrand activity (VWF), since factor VIII coagulant activity, factor VIII related antigen, and isolated VWF were normal or high by European standards. Ristocetin 53-63 von Willebrand factor Homo sapiens 294-297 307006-1 1978 Ristocetin will induce the agglutination of platelets in the presence of von Willebrand factor. Ristocetin 0-10 von Willebrand factor Homo sapiens 73-94 307006-2 1978 In previous studies, an electrostatic mechanism was proposed for this phenomenon wherein first the platelet"s surface charge is reduced by the binding of ristocetin and then the von Willebrand factor acts as a bridge between platelets. Ristocetin 154-164 von Willebrand factor Homo sapiens 178-199 6967100-1 1980 Ristocetin induces platelet agglutination in the presence of human factor VIII-associated ristocetin cofactor (vWF). Ristocetin 0-10 von Willebrand factor Homo sapiens 111-114 6967100-1 1980 Ristocetin induces platelet agglutination in the presence of human factor VIII-associated ristocetin cofactor (vWF). Ristocetin 90-100 von Willebrand factor Homo sapiens 111-114 6967100-4 1980 Radioiodinated vWF, a disulfide-linked polymer of 230,000 dalton subunits, attached to formalinized human platelets only in the presence of ristocetin. Ristocetin 140-150 von Willebrand factor Homo sapiens 15-18 6967100-6 1980 Ristocetin-induced binding was inhibited by vancomycin, unlabeled-purified vWF polymers, normal and hemophilia A plasma, and rabbit anti-human vWF. Ristocetin 0-10 von Willebrand factor Homo sapiens 75-78 6967100-6 1980 Ristocetin-induced binding was inhibited by vancomycin, unlabeled-purified vWF polymers, normal and hemophilia A plasma, and rabbit anti-human vWF. Ristocetin 0-10 von Willebrand factor Homo sapiens 143-146 6967100-11 1980 These results indicate that (1) the initial binding of human vWF polymers to platelets is a specific interaction which requires the presence of ristocetin; (2) ristocetin and human vWF do not form persistent complexes in solution; and (3) the association of ristocetin and platelets is of low affinity. Ristocetin 144-154 von Willebrand factor Homo sapiens 61-64 6967100-11 1980 These results indicate that (1) the initial binding of human vWF polymers to platelets is a specific interaction which requires the presence of ristocetin; (2) ristocetin and human vWF do not form persistent complexes in solution; and (3) the association of ristocetin and platelets is of low affinity. Ristocetin 160-170 von Willebrand factor Homo sapiens 61-64 6967100-11 1980 These results indicate that (1) the initial binding of human vWF polymers to platelets is a specific interaction which requires the presence of ristocetin; (2) ristocetin and human vWF do not form persistent complexes in solution; and (3) the association of ristocetin and platelets is of low affinity. Ristocetin 160-170 von Willebrand factor Homo sapiens 61-64 316281-1 1979 An inexpensive assay for von Willebrand factor using microtitration plates, formalin-fixed platelets, and ristocetin is described. Ristocetin 106-116 von Willebrand factor Homo sapiens 25-46 307560-2 1978 The normal Factor VIII/von Willebrand factor protein has the ability to agglutinate or aggregate normal platelets in the presence of ristocetin (von Willebrand factor activity). Ristocetin 133-143 von Willebrand factor Homo sapiens 23-44 307560-2 1978 The normal Factor VIII/von Willebrand factor protein has the ability to agglutinate or aggregate normal platelets in the presence of ristocetin (von Willebrand factor activity). Ristocetin 133-143 von Willebrand factor Homo sapiens 145-166 309191-1 1978 The aggregation of platelets by the antibiotic, ristocetin, requires a plasma cofactor (VIII:vWF) and one or more specific binding sites on the platelet membrane. Ristocetin 48-58 von Willebrand factor Homo sapiens 93-96 309191-3 1978 In the presence of ristocetin (1.5 mg/ml), from 70 to 90% of the 125I-VIII:vWF became platelet-bound. Ristocetin 19-29 von Willebrand factor Homo sapiens 75-78 309191-7 1978 It is concluded that VIII:vWF binds to the platelet membrane in the presence of ristocetin. Ristocetin 80-90 von Willebrand factor Homo sapiens 26-29 1087117-3 1976 Ristocetin-induced platelet aggregation causes a consumption of vWF, Factor VIII procoagulant activity, and Factor VIII antigen from the supernatant plasma which is proportional to the number of platelets aggregated. Ristocetin 0-10 von Willebrand factor Homo sapiens 64-67 1080491-6 1975 However, the partially purified Factor VIII/von Willebrand factor protein had markedly reduced von Willebrand factor activity in a ristocetin assay. Ristocetin 131-141 von Willebrand factor Homo sapiens 44-65 1080491-6 1975 However, the partially purified Factor VIII/von Willebrand factor protein had markedly reduced von Willebrand factor activity in a ristocetin assay. Ristocetin 131-141 von Willebrand factor Homo sapiens 95-116 32774267-6 2020 The VWF ristocetin cofactor assay (VWF: RCo) was low, but VWF antigen level (VWF: Ag) was normal. Ristocetin 8-18 von Willebrand factor Homo sapiens 4-7 1168691-3 1975 The antibiotic ristocetin, which aggregates human platelets in the presence of von Willebrand factor, nonspecifically precipitates platelet membrane factor VIII antigen. Ristocetin 15-25 von Willebrand factor Homo sapiens 79-100 4542944-4 1973 In the present paper, we describe, an assay for this factor, the von Willebrand factor (VIII(VWF)), based on the observation that a log-log relationship exists between the amount of ristocetin-induced aggregation of washed, normal platelets and the concentration of normal plasma present in the test system. Ristocetin 182-192 von Willebrand factor Homo sapiens 65-86 4542944-4 1973 In the present paper, we describe, an assay for this factor, the von Willebrand factor (VIII(VWF)), based on the observation that a log-log relationship exists between the amount of ristocetin-induced aggregation of washed, normal platelets and the concentration of normal plasma present in the test system. Ristocetin 182-192 von Willebrand factor Homo sapiens 88-97 32607039-7 2020 PK parameters for VWF markers were generally comparable to adults but showed lower VWF:ristocetin cofactor (RCo) exposure. Ristocetin 87-97 von Willebrand factor Homo sapiens 18-21 32607039-7 2020 PK parameters for VWF markers were generally comparable to adults but showed lower VWF:ristocetin cofactor (RCo) exposure. Ristocetin 87-97 von Willebrand factor Homo sapiens 83-86 33387210-6 2021 These results were associated with higher agglutination rates induced by ristocetin, thereby indirectly indicating an increased capability of vWF to bind to platelets. Ristocetin 73-83 von Willebrand factor Homo sapiens 142-145 32774267-6 2020 The VWF ristocetin cofactor assay (VWF: RCo) was low, but VWF antigen level (VWF: Ag) was normal. Ristocetin 8-18 von Willebrand factor Homo sapiens 35-38 32774267-6 2020 The VWF ristocetin cofactor assay (VWF: RCo) was low, but VWF antigen level (VWF: Ag) was normal. Ristocetin 8-18 von Willebrand factor Homo sapiens 35-38 31229334-5 2019 More recently, the treatment of VWD has undergone a slow yet significant change from plasma-derived VWF/FVIII concentrates with VWF:ristocetin cofactor (RCo)/FVIII ratios <=1, to those with VWF:RCo/FVIII ratios >10, to a recombinant VWF. Ristocetin 132-142 von Willebrand factor Homo sapiens 128-131 31229334-5 2019 More recently, the treatment of VWD has undergone a slow yet significant change from plasma-derived VWF/FVIII concentrates with VWF:ristocetin cofactor (RCo)/FVIII ratios <=1, to those with VWF:RCo/FVIII ratios >10, to a recombinant VWF. Ristocetin 132-142 von Willebrand factor Homo sapiens 100-103 31229334-5 2019 More recently, the treatment of VWD has undergone a slow yet significant change from plasma-derived VWF/FVIII concentrates with VWF:ristocetin cofactor (RCo)/FVIII ratios <=1, to those with VWF:RCo/FVIII ratios >10, to a recombinant VWF. Ristocetin 132-142 von Willebrand factor Homo sapiens 128-131 31229334-5 2019 More recently, the treatment of VWD has undergone a slow yet significant change from plasma-derived VWF/FVIII concentrates with VWF:ristocetin cofactor (RCo)/FVIII ratios <=1, to those with VWF:RCo/FVIII ratios >10, to a recombinant VWF. Ristocetin 132-142 von Willebrand factor Homo sapiens 128-131 30849118-10 2019 In contrast, induction of binding of VWF to glycoprotein 1b on platelets using the VWF-activating protein ristocetin resulted in the removal of platelet sialic acid by translocation of platelet neuraminidase to the platelet surface. Ristocetin 106-116 von Willebrand factor Homo sapiens 37-40 30592326-1 2019 von Willebrand factor (VWF) ristocetin cofactor activity (VWF:RCo) by platelet aggregometry has been considered the gold standard for evaluating the ability of VWF to bind platelets for over 40 years. Ristocetin 28-38 von Willebrand factor Homo sapiens 0-21 30592326-1 2019 von Willebrand factor (VWF) ristocetin cofactor activity (VWF:RCo) by platelet aggregometry has been considered the gold standard for evaluating the ability of VWF to bind platelets for over 40 years. Ristocetin 28-38 von Willebrand factor Homo sapiens 23-26 30592326-1 2019 von Willebrand factor (VWF) ristocetin cofactor activity (VWF:RCo) by platelet aggregometry has been considered the gold standard for evaluating the ability of VWF to bind platelets for over 40 years. Ristocetin 28-38 von Willebrand factor Homo sapiens 58-61 30592326-1 2019 von Willebrand factor (VWF) ristocetin cofactor activity (VWF:RCo) by platelet aggregometry has been considered the gold standard for evaluating the ability of VWF to bind platelets for over 40 years. Ristocetin 28-38 von Willebrand factor Homo sapiens 58-61 30849118-10 2019 In contrast, induction of binding of VWF to glycoprotein 1b on platelets using the VWF-activating protein ristocetin resulted in the removal of platelet sialic acid by translocation of platelet neuraminidase to the platelet surface. Ristocetin 106-116 von Willebrand factor Homo sapiens 83-86 31359769-8 2019 However, VWF ristocetin cofactor activity or gain-of-function mutant glycoprotein Ib binding activity <36.5 IU/dL and VWF collagen binding activity <34.5 IU/dL could predict increased bleeding risk (BS >=3) by 92.3% specificity and 70.0% sensitivity (P < .0001). Ristocetin 13-23 von Willebrand factor Homo sapiens 9-12 30450617-7 2019 RESULTS: While vWF-ristocetin cofactor activity is significantly decreased (-41.13%; p < .0001) in SpDP, a model of vWF-mediated platelet adhesion to collagen under flow showed enhanced function (+13%; p < .01). Ristocetin 19-29 von Willebrand factor Homo sapiens 15-18 30450617-11 2019 The apparent paradox between vWF-ristocetin cofactor assay and vWF-mediated platelet adhesion may be explained by the increase in smaller multimers of vWF in SpDP, producing different outcomes in these assays. Ristocetin 33-43 von Willebrand factor Homo sapiens 29-32 30084138-4 2018 RESULTS: PFA-100 was always significantly prolonged, and ristocetin-induced platelet aggregation (RIPA) and VWF ristocetin cofactor (VWF:RCo) greatly reduced or absent. Ristocetin 112-122 von Willebrand factor Homo sapiens 108-111 30337247-8 2018 FINDINGS: Both rLep-vWA-I and rLep-vWA-II were able to bind to Hu-platelets and inhibit rHu-vWF/ristocetin-induced Hu-platelet aggregation, but Hu-GPIbalpha-IgG, rLep-vWA-I-IgG and rLep-vWA-II-IgG blocked this binding or inhibition. Ristocetin 96-106 von Willebrand factor Homo sapiens 92-95 29985231-0 2018 Perhaps it"s not the platelet: Ristocetin uncovers the potential role of von Willebrand factor in impaired platelet aggregation following traumatic brain injury. Ristocetin 31-41 von Willebrand factor Homo sapiens 73-94 29985231-2 2018 Ristocetin is an antimicrobial substance that induces vWF-mediated aggregation of platelets. Ristocetin 0-10 von Willebrand factor Homo sapiens 54-57 29985231-15 2018 The impaired platelet aggregation response to ristocetin stimulation and corresponding increase in factor VIII activity in TBI patients may be secondary to a TBI-induced effect on vWF quantity (due to injury-driven consumption of vWF) or vWF function with resultant increase in circulating factor VIII activity (due to impaired carrying capacity of vWF). Ristocetin 46-56 von Willebrand factor Homo sapiens 180-183 29985231-15 2018 The impaired platelet aggregation response to ristocetin stimulation and corresponding increase in factor VIII activity in TBI patients may be secondary to a TBI-induced effect on vWF quantity (due to injury-driven consumption of vWF) or vWF function with resultant increase in circulating factor VIII activity (due to impaired carrying capacity of vWF). Ristocetin 46-56 von Willebrand factor Homo sapiens 230-233 29985231-15 2018 The impaired platelet aggregation response to ristocetin stimulation and corresponding increase in factor VIII activity in TBI patients may be secondary to a TBI-induced effect on vWF quantity (due to injury-driven consumption of vWF) or vWF function with resultant increase in circulating factor VIII activity (due to impaired carrying capacity of vWF). Ristocetin 46-56 von Willebrand factor Homo sapiens 230-233 29985231-15 2018 The impaired platelet aggregation response to ristocetin stimulation and corresponding increase in factor VIII activity in TBI patients may be secondary to a TBI-induced effect on vWF quantity (due to injury-driven consumption of vWF) or vWF function with resultant increase in circulating factor VIII activity (due to impaired carrying capacity of vWF). Ristocetin 46-56 von Willebrand factor Homo sapiens 230-233 29355554-6 2018 Furthermore, a solid phase binding assay revealed that HY023016 inhibited ristocetin-induced washed platelets bind to von Willebrand factor (vWF). Ristocetin 74-84 von Willebrand factor Homo sapiens 118-139 29897666-6 2018 The new assays appear to have improved performance characteristics compared with the old reference standard, ristocetin cofactor activity (VWF:RCo), but information is limited about how they compare with VWF:RCo and each other. Ristocetin 109-119 von Willebrand factor Homo sapiens 139-142 29140542-4 2018 Accordingly, we observed that vWF-Ag and its activity-estimated by ristocetin cofactor measurement-increased immediately after induction of liver regeneration and was associated with platelet accumulation within the liver. Ristocetin 67-77 von Willebrand factor Homo sapiens 30-33 29355554-6 2018 Furthermore, a solid phase binding assay revealed that HY023016 inhibited ristocetin-induced washed platelets bind to von Willebrand factor (vWF). Ristocetin 74-84 von Willebrand factor Homo sapiens 141-144 29651351-5 2018 Ristocetin cofactor activity (VWF:RCo) was 0.09 IU/ml, and collagen binding activity (VWF:CB) was 0.10 IU/ml. Ristocetin 0-10 von Willebrand factor Homo sapiens 30-33 29168270-2 2018 Current VWF activity tests include ristocetin cofactor and collagen binding (VWF:CB) assays. Ristocetin 35-45 von Willebrand factor Homo sapiens 8-11 28957942-5 2018 The process resulted in a very highly purified vWF, with a mean specific activity of 95.3 IU of vWF:ristocetin cofactor assay/mg of total proteins. Ristocetin 100-110 von Willebrand factor Homo sapiens 47-50 28957942-5 2018 The process resulted in a very highly purified vWF, with a mean specific activity of 95.3 IU of vWF:ristocetin cofactor assay/mg of total proteins. Ristocetin 100-110 von Willebrand factor Homo sapiens 96-99 30046704-5 2018 Historically, VWF binding to platelet GPIbalpha was measured by the ristocetin cofactor assay (VWF:RCo); a new assay using platelet GPIbalpha in the absence of ristocetin (VWF:GPIbM) is gradually replacing the VWF:RCo due to improved accuracy in diagnosis. Ristocetin 68-78 von Willebrand factor Homo sapiens 14-17 28120508-2 2017 Diagnosis requires measurement of VWF-platelet binding function, for which VWF ristocetin cofactor activity (VWF:RCo) is the reference method. Ristocetin 79-89 von Willebrand factor Homo sapiens 75-78 29126301-20 2017 Testing the functional activity of VWF, utilizes the drug ristocetin.The state of multimerization of VWF is important and is assessed by electrophoresis on agarose gels. Ristocetin 58-68 von Willebrand factor Homo sapiens 35-38 29126301-20 2017 Testing the functional activity of VWF, utilizes the drug ristocetin.The state of multimerization of VWF is important and is assessed by electrophoresis on agarose gels. Ristocetin 58-68 von Willebrand factor Homo sapiens 101-104 28603902-12 2017 Results The phosphorylation levels of ERK5 were significantly enhanced in human platelets stimulated with botrocetin/VWF or ristocetin/VWF. Ristocetin 124-134 von Willebrand factor Homo sapiens 135-138 28640903-3 2017 The minimum aggregating dose of ristocetin was similarly reduced in both patient groups, and modulated by their underlying VWF mutations. Ristocetin 32-42 von Willebrand factor Homo sapiens 123-126 28120508-2 2017 Diagnosis requires measurement of VWF-platelet binding function, for which VWF ristocetin cofactor activity (VWF:RCo) is the reference method. Ristocetin 79-89 von Willebrand factor Homo sapiens 75-78 28279966-9 2017 Rather under shear stress conditions, or in the presence of denaturants, such as urea or ristocetin, plasmin cleaves the K1491-R1492 peptide bond within the VWF A1-A2 linker region. Ristocetin 89-99 von Willebrand factor Homo sapiens 157-160 26172561-1 2015 BACKGROUND: The ability of von Willebrand factor (VWF) to bind platelet GP Ib and promote platelet plug formation is measured in vitro using the ristocetin cofactor (VWF:RCo) assay. Ristocetin 145-155 von Willebrand factor Homo sapiens 27-48 28804843-5 2017 Classically, the most often used assay for measuring GPIb binding activity was the ristocetin cofactor assay (VWF:RCo), which historically measured agglutination of fixed human platelets by VWF in the presence of ristocetin. Ristocetin 83-93 von Willebrand factor Homo sapiens 110-113 28804843-5 2017 Classically, the most often used assay for measuring GPIb binding activity was the ristocetin cofactor assay (VWF:RCo), which historically measured agglutination of fixed human platelets by VWF in the presence of ristocetin. Ristocetin 83-93 von Willebrand factor Homo sapiens 190-193 28804843-5 2017 Classically, the most often used assay for measuring GPIb binding activity was the ristocetin cofactor assay (VWF:RCo), which historically measured agglutination of fixed human platelets by VWF in the presence of ristocetin. Ristocetin 213-223 von Willebrand factor Homo sapiens 110-113 28804846-4 2017 The current paper describes several protocols for assessment of VWF activity by means of VWF ristocetin cofactor (VWF:RCo). Ristocetin 93-103 von Willebrand factor Homo sapiens 64-67 28804846-4 2017 The current paper describes several protocols for assessment of VWF activity by means of VWF ristocetin cofactor (VWF:RCo). Ristocetin 93-103 von Willebrand factor Homo sapiens 89-92 28804846-4 2017 The current paper describes several protocols for assessment of VWF activity by means of VWF ristocetin cofactor (VWF:RCo). Ristocetin 93-103 von Willebrand factor Homo sapiens 89-92 28804846-5 2017 These assays identify VWF activity by quantitative assessment of VWF protein adhesion to platelets or other particles and subsequent detection of the adhered VWF as facilitated by inclusion of ristocetin. Ristocetin 193-203 von Willebrand factor Homo sapiens 22-25 28804847-3 2017 For many years, the most frequently used assay for measuring GPIb binding activity was the ristocetin cofactor assay (VWF:RCo), which measures the agglutination of fixed human platelets by VWF in the presence of ristocetin. Ristocetin 91-101 von Willebrand factor Homo sapiens 118-121 28804847-3 2017 For many years, the most frequently used assay for measuring GPIb binding activity was the ristocetin cofactor assay (VWF:RCo), which measures the agglutination of fixed human platelets by VWF in the presence of ristocetin. Ristocetin 91-101 von Willebrand factor Homo sapiens 189-192 28804847-3 2017 For many years, the most frequently used assay for measuring GPIb binding activity was the ristocetin cofactor assay (VWF:RCo), which measures the agglutination of fixed human platelets by VWF in the presence of ristocetin. Ristocetin 212-222 von Willebrand factor Homo sapiens 118-121 28804847-5 2017 One published method (now abbreviated VWF:GPIbR) uses wild-type GPIb for triggering the binding reaction in the presence of ristocetin. Ristocetin 124-134 von Willebrand factor Homo sapiens 38-41 28804847-6 2017 Another more widely used method (now abbreviated VWF:GPIbM) uses gain-of-function GPIb without ristocetin; this permits spontaneous binding of VWF to GPIb and avoids problems associated with the nonphysiological substance ristocetin. Ristocetin 95-105 von Willebrand factor Homo sapiens 49-52 28804847-6 2017 Another more widely used method (now abbreviated VWF:GPIbM) uses gain-of-function GPIb without ristocetin; this permits spontaneous binding of VWF to GPIb and avoids problems associated with the nonphysiological substance ristocetin. Ristocetin 222-232 von Willebrand factor Homo sapiens 49-52 28804849-1 2017 Ristocetin-induced platelet aggregation (RIPA) is used as an in vitro test to determine the presence and integrity of the platelet glycoprotein (GP) Ibalpha-V-IX complex and von Willebrand factor (VWF) interaction and is usually performed using platelet-rich plasma (PRP). Ristocetin 0-10 von Willebrand factor Homo sapiens 174-195 28804849-1 2017 Ristocetin-induced platelet aggregation (RIPA) is used as an in vitro test to determine the presence and integrity of the platelet glycoprotein (GP) Ibalpha-V-IX complex and von Willebrand factor (VWF) interaction and is usually performed using platelet-rich plasma (PRP). Ristocetin 0-10 von Willebrand factor Homo sapiens 197-200 28804849-2 2017 Impairment in the response of VWF/GPIbalpha-V-IX is measured with reference to several established concentrations of ristocetin and may indicate defects in VWF or in GPIbalpha-V-IX function. Ristocetin 117-127 von Willebrand factor Homo sapiens 30-33 28804849-4 2017 For example, the correction of an abnormal RIPA trace after mixing PRP with normal plasma and rechallenging with ristocetin at 1.0 mg/mL suggests VWF function/quantity defect. Ristocetin 113-123 von Willebrand factor Homo sapiens 146-149 27749315-5 2016 The clinical profile of this young girl and the findings of less than 5% for von Willebrand factor (VWF):Ag and 10% for VWF Ristocetin cofactor suggests a type 3 VWD. Ristocetin 124-134 von Willebrand factor Homo sapiens 120-123 27040683-8 2016 Finally, in a patient with IgG MM, maximally prolonged PFA-100 closure times and a specific defect in ristocetin-induced platelet agglutination, both of which resolved after remission induction, indicated interference of the paraprotein with VWF binding to platelet GPIb. Ristocetin 103-113 von Willebrand factor Homo sapiens 243-246 28142075-6 2017 METHODS: Platelet TF-PCA was induced by GPIbalpha activation with VWF-ristocetin. Ristocetin 70-80 von Willebrand factor Homo sapiens 66-69 27978591-1 2017 von Willebrand disease type 2B (VWD2B) expresses gain-of-function mutations that enhance binding of an individual"s von Willebrand factor (VWF) to its platelet ligand, glycoprotein Ib (GPIb), and which are usually identified by increased ristocetin-induced platelet aggregation (RIPA). Ristocetin 238-248 von Willebrand factor Homo sapiens 116-137 27978591-1 2017 von Willebrand disease type 2B (VWD2B) expresses gain-of-function mutations that enhance binding of an individual"s von Willebrand factor (VWF) to its platelet ligand, glycoprotein Ib (GPIb), and which are usually identified by increased ristocetin-induced platelet aggregation (RIPA). Ristocetin 238-248 von Willebrand factor Homo sapiens 139-142 27913545-3 2016 While VWF protein measurements by immunoassay are reasonably comparable between institutions, the measurement of VWF ristocetin cofactor activity (VWF:RCo) has significant variability. Ristocetin 117-127 von Willebrand factor Homo sapiens 113-116 27913545-3 2016 While VWF protein measurements by immunoassay are reasonably comparable between institutions, the measurement of VWF ristocetin cofactor activity (VWF:RCo) has significant variability. Ristocetin 117-127 von Willebrand factor Homo sapiens 113-116 27554083-5 2016 In A1-A2-A3 and full-length VWF, this macrophage-binding site is cryptic but becomes exposed following exposure to shear or ristocetin. Ristocetin 124-134 von Willebrand factor Homo sapiens 28-31 27716777-8 2016 In agreement with the proteomics data, small molecule inhibitors of thioredoxin selectively inhibited GPVI-mediated platelet activation, and attenuated ristocetin-induced GPIb-vWF-mediated platelet agglutination, thus validating the findings of the proteomics study. Ristocetin 152-162 von Willebrand factor Homo sapiens 176-179 27184018-5 2016 The functionality of stored platelets was determined employing aggregometry and ristocetin-induced VWF binding. Ristocetin 80-90 von Willebrand factor Homo sapiens 99-102 27184018-8 2016 Also, ristocetin-induced VWF binding was impaired in a small population of platelets. Ristocetin 6-16 von Willebrand factor Homo sapiens 25-28 27651919-5 2016 VWF function was determined by ristocetin-induced platelet aggregation (VWF ristocetin cofactor, VWF:RCo) and VWF levels by turbidimetric assay (VWF antigen, VWF:Ag). Ristocetin 31-41 von Willebrand factor Homo sapiens 0-3 27651919-5 2016 VWF function was determined by ristocetin-induced platelet aggregation (VWF ristocetin cofactor, VWF:RCo) and VWF levels by turbidimetric assay (VWF antigen, VWF:Ag). Ristocetin 76-86 von Willebrand factor Homo sapiens 0-3 27052467-6 2016 VWF binding to MMRN1 was enhanced by shear exposure and ristocetin, and required VWF A1A2A3 region, specifically the A1 and A3 domains. Ristocetin 56-66 von Willebrand factor Homo sapiens 0-3 27148840-1 2016 Type 2B von Willebrand disease (VWD2B) is a rare, autosomal-dominant inherited bleeding disorder, characterized by an enhanced ristocetin-induced platelet aggregation in platelet-rich plasma and often with variable degree of thrombocytopenia and loss of high-molecular-weight multimers von Willebrand factor (VWF). Ristocetin 127-137 von Willebrand factor Homo sapiens 286-307 27148840-1 2016 Type 2B von Willebrand disease (VWD2B) is a rare, autosomal-dominant inherited bleeding disorder, characterized by an enhanced ristocetin-induced platelet aggregation in platelet-rich plasma and often with variable degree of thrombocytopenia and loss of high-molecular-weight multimers von Willebrand factor (VWF). Ristocetin 127-137 von Willebrand factor Homo sapiens 309-312 27237807-4 2016 We compared the new assay with the reference assay: ristocetin cofactor activity (VWF:RCo) performed on the BCS-XP analyser by testing retrospectively samples from 82 healthy normal subjects and 61 patients with von Willebrand disease (VWD). Ristocetin 52-62 von Willebrand factor Homo sapiens 82-85 26172561-1 2015 BACKGROUND: The ability of von Willebrand factor (VWF) to bind platelet GP Ib and promote platelet plug formation is measured in vitro using the ristocetin cofactor (VWF:RCo) assay. Ristocetin 145-155 von Willebrand factor Homo sapiens 50-53 26172561-1 2015 BACKGROUND: The ability of von Willebrand factor (VWF) to bind platelet GP Ib and promote platelet plug formation is measured in vitro using the ristocetin cofactor (VWF:RCo) assay. Ristocetin 145-155 von Willebrand factor Homo sapiens 166-169 26172561-14 2015 This study indicates that the specific modifications - namely the combination of increased ristocetin concentration, reduced platelet content, VWF-depleted plasma as on-board diluent and a two-curve calculation mode - reduces the issues seen with current VWF:RCo activity assays. Ristocetin 91-101 von Willebrand factor Homo sapiens 255-258 26206100-1 2015 BACKGROUND: Diagnosis of von Willebrand disease (VWD) type 2 usually relies on the discrepancy between the von Willebrand factor (VWF) ristocetin cofactor activity (VWF:RCo) and VWF antigen (VWF:Ag). Ristocetin 135-145 von Willebrand factor Homo sapiens 130-133 26206100-1 2015 BACKGROUND: Diagnosis of von Willebrand disease (VWD) type 2 usually relies on the discrepancy between the von Willebrand factor (VWF) ristocetin cofactor activity (VWF:RCo) and VWF antigen (VWF:Ag). Ristocetin 135-145 von Willebrand factor Homo sapiens 107-128 26206100-1 2015 BACKGROUND: Diagnosis of von Willebrand disease (VWD) type 2 usually relies on the discrepancy between the von Willebrand factor (VWF) ristocetin cofactor activity (VWF:RCo) and VWF antigen (VWF:Ag). Ristocetin 135-145 von Willebrand factor Homo sapiens 165-168 26206100-1 2015 BACKGROUND: Diagnosis of von Willebrand disease (VWD) type 2 usually relies on the discrepancy between the von Willebrand factor (VWF) ristocetin cofactor activity (VWF:RCo) and VWF antigen (VWF:Ag). Ristocetin 135-145 von Willebrand factor Homo sapiens 165-168 26206100-1 2015 BACKGROUND: Diagnosis of von Willebrand disease (VWD) type 2 usually relies on the discrepancy between the von Willebrand factor (VWF) ristocetin cofactor activity (VWF:RCo) and VWF antigen (VWF:Ag). Ristocetin 135-145 von Willebrand factor Homo sapiens 165-168 25753785-4 2015 We have chosen to study the reliability of PFA-100 for screening VWF ristocetin cofactor (VWF:RCo) deficiency. Ristocetin 69-79 von Willebrand factor Homo sapiens 65-68 25753785-4 2015 We have chosen to study the reliability of PFA-100 for screening VWF ristocetin cofactor (VWF:RCo) deficiency. Ristocetin 69-79 von Willebrand factor Homo sapiens 90-93 25935884-6 2015 RESULTS: At baseline, a significant link between vWF abnormalities and the severity of AVS was evidenced: mean aortic transvalvular gradient was negatively correlated with the levels of vWF antigen (vWF:Ag) (r = -0.29; P < 0.05), vWF ristocetin cofactor activity (r = -0.402; P = 0.006), and vWF collagen-binding activity (vWF:CB; r = -0.441; P = 0.005). Ristocetin 237-247 von Willebrand factor Homo sapiens 49-52 25935884-6 2015 RESULTS: At baseline, a significant link between vWF abnormalities and the severity of AVS was evidenced: mean aortic transvalvular gradient was negatively correlated with the levels of vWF antigen (vWF:Ag) (r = -0.29; P < 0.05), vWF ristocetin cofactor activity (r = -0.402; P = 0.006), and vWF collagen-binding activity (vWF:CB; r = -0.441; P = 0.005). Ristocetin 237-247 von Willebrand factor Homo sapiens 186-189 25935884-6 2015 RESULTS: At baseline, a significant link between vWF abnormalities and the severity of AVS was evidenced: mean aortic transvalvular gradient was negatively correlated with the levels of vWF antigen (vWF:Ag) (r = -0.29; P < 0.05), vWF ristocetin cofactor activity (r = -0.402; P = 0.006), and vWF collagen-binding activity (vWF:CB; r = -0.441; P = 0.005). Ristocetin 237-247 von Willebrand factor Homo sapiens 186-189 25935884-6 2015 RESULTS: At baseline, a significant link between vWF abnormalities and the severity of AVS was evidenced: mean aortic transvalvular gradient was negatively correlated with the levels of vWF antigen (vWF:Ag) (r = -0.29; P < 0.05), vWF ristocetin cofactor activity (r = -0.402; P = 0.006), and vWF collagen-binding activity (vWF:CB; r = -0.441; P = 0.005). Ristocetin 237-247 von Willebrand factor Homo sapiens 186-189 25935884-6 2015 RESULTS: At baseline, a significant link between vWF abnormalities and the severity of AVS was evidenced: mean aortic transvalvular gradient was negatively correlated with the levels of vWF antigen (vWF:Ag) (r = -0.29; P < 0.05), vWF ristocetin cofactor activity (r = -0.402; P = 0.006), and vWF collagen-binding activity (vWF:CB; r = -0.441; P = 0.005). Ristocetin 237-247 von Willebrand factor Homo sapiens 186-189 24658160-9 2014 Decoration with VBP resulted in substantial construct adhesion to ristocetin-treated VWF even if the A1-domain was blocked by glycocalicin. Ristocetin 66-76 von Willebrand factor Homo sapiens 85-88 25728415-8 2015 As expected, full-length wt-VWF was unable to bind LRP1 under static conditions unless ristocetin was added. Ristocetin 87-97 von Willebrand factor Homo sapiens 28-31 25103956-1 2014 The ristocetin cofactor activity assay (VWF:RCo) is the reference method for assessing von Willebrand factor (VWF) activity but remains difficult to perform, and the coefficient of variation of the method is high (about 20-30%). Ristocetin 4-14 von Willebrand factor Homo sapiens 40-43 24978322-6 2014 The early 1970s saw a revolution in diagnostics when ristocetin was identified to induce platelet aggregation, and this formed the basis of the first consistent and reliable VWF "activity" test, permitting quantification of the platelet adhesive function missing in VWD. Ristocetin 53-63 von Willebrand factor Homo sapiens 174-177 24750680-2 2014 Technical innovations have been applied to improve the precision and lower limit of detection of von Willebrand factor (VWF) assays, including the ristocetin cofactor activity assay (VWF:RCo) that uses the antibiotic ristocetin to induce plasma VWF binding to glycoprotein (GP) IbIXV on target platelets. Ristocetin 147-157 von Willebrand factor Homo sapiens 183-186 24750680-2 2014 Technical innovations have been applied to improve the precision and lower limit of detection of von Willebrand factor (VWF) assays, including the ristocetin cofactor activity assay (VWF:RCo) that uses the antibiotic ristocetin to induce plasma VWF binding to glycoprotein (GP) IbIXV on target platelets. Ristocetin 147-157 von Willebrand factor Homo sapiens 183-186 24750680-2 2014 Technical innovations have been applied to improve the precision and lower limit of detection of von Willebrand factor (VWF) assays, including the ristocetin cofactor activity assay (VWF:RCo) that uses the antibiotic ristocetin to induce plasma VWF binding to glycoprotein (GP) IbIXV on target platelets. Ristocetin 217-227 von Willebrand factor Homo sapiens 183-186 24750680-2 2014 Technical innovations have been applied to improve the precision and lower limit of detection of von Willebrand factor (VWF) assays, including the ristocetin cofactor activity assay (VWF:RCo) that uses the antibiotic ristocetin to induce plasma VWF binding to glycoprotein (GP) IbIXV on target platelets. Ristocetin 217-227 von Willebrand factor Homo sapiens 183-186 24750680-5 2014 Some common polymorphisms in the VWF gene that do not cause bleeding are associated with falsely low VWF activity by ristocetin-dependent methods. Ristocetin 117-127 von Willebrand factor Homo sapiens 33-36 24750680-6 2014 To overcome the need for ristocetin, some new VWF activity assays use gain-of-function GPIbalpha mutants that bind VWF without the need for ristocetin, with an improved precision and lower limit of detection than measuring VWF:RCo by aggregometry. Ristocetin 25-35 von Willebrand factor Homo sapiens 46-49 24750680-6 2014 To overcome the need for ristocetin, some new VWF activity assays use gain-of-function GPIbalpha mutants that bind VWF without the need for ristocetin, with an improved precision and lower limit of detection than measuring VWF:RCo by aggregometry. Ristocetin 140-150 von Willebrand factor Homo sapiens 46-49 24750681-1 2014 INTRODUCTION: The development of an automated, von Willebrand factor (VWF) activity assay, Innovance( ) VWF Ac (VWF:Ac), which measures VWF binding to the platelet receptor glycoprotein Ibalpha without ristocetin, led us to evaluate the assay for diagnosing von Willebrand disease (VWD) and monitoring therapy. Ristocetin 202-212 von Willebrand factor Homo sapiens 47-68 24750681-1 2014 INTRODUCTION: The development of an automated, von Willebrand factor (VWF) activity assay, Innovance( ) VWF Ac (VWF:Ac), which measures VWF binding to the platelet receptor glycoprotein Ibalpha without ristocetin, led us to evaluate the assay for diagnosing von Willebrand disease (VWD) and monitoring therapy. Ristocetin 202-212 von Willebrand factor Homo sapiens 70-73 24750681-1 2014 INTRODUCTION: The development of an automated, von Willebrand factor (VWF) activity assay, Innovance( ) VWF Ac (VWF:Ac), which measures VWF binding to the platelet receptor glycoprotein Ibalpha without ristocetin, led us to evaluate the assay for diagnosing von Willebrand disease (VWD) and monitoring therapy. Ristocetin 202-212 von Willebrand factor Homo sapiens 104-107 24750681-1 2014 INTRODUCTION: The development of an automated, von Willebrand factor (VWF) activity assay, Innovance( ) VWF Ac (VWF:Ac), which measures VWF binding to the platelet receptor glycoprotein Ibalpha without ristocetin, led us to evaluate the assay for diagnosing von Willebrand disease (VWD) and monitoring therapy. Ristocetin 202-212 von Willebrand factor Homo sapiens 104-107 25661290-2 2015 Measurement of von Willebrand factor (VWF) activity in plasma is often based on platelet agglutination stimulated by the ristocetin cofactor activity. Ristocetin 121-131 von Willebrand factor Homo sapiens 15-36 25661290-2 2015 Measurement of von Willebrand factor (VWF) activity in plasma is often based on platelet agglutination stimulated by the ristocetin cofactor activity. Ristocetin 121-131 von Willebrand factor Homo sapiens 38-41 25192242-0 2014 Performance evaluation and multicentre study of a von Willebrand factor activity assay based on GPIb binding in the absence of ristocetin. Ristocetin 127-137 von Willebrand factor Homo sapiens 50-71 25192242-1 2014 The functional activity of von Willebrand factor (VWF) is most frequently measured by using the ristocetin cofactor assay (VWF:RCo). Ristocetin 96-106 von Willebrand factor Homo sapiens 27-48 25192242-1 2014 The functional activity of von Willebrand factor (VWF) is most frequently measured by using the ristocetin cofactor assay (VWF:RCo). Ristocetin 96-106 von Willebrand factor Homo sapiens 50-53 25192242-1 2014 The functional activity of von Willebrand factor (VWF) is most frequently measured by using the ristocetin cofactor assay (VWF:RCo). Ristocetin 96-106 von Willebrand factor Homo sapiens 123-126 24891215-1 2014 INTRODUCTION: Ristocetin cofactor activity of Von Willebrand factor (VWF:RCo) and the ratio VWF:RCo to its antigen VWF:Ag are used as routine screening to estimate VWF function and to detect types of Von Willebrand disease (VWD) caused by loss of high molecular weight multimers. Ristocetin 14-24 von Willebrand factor Homo sapiens 46-67 24891215-1 2014 INTRODUCTION: Ristocetin cofactor activity of Von Willebrand factor (VWF:RCo) and the ratio VWF:RCo to its antigen VWF:Ag are used as routine screening to estimate VWF function and to detect types of Von Willebrand disease (VWD) caused by loss of high molecular weight multimers. Ristocetin 14-24 von Willebrand factor Homo sapiens 69-72 24786773-4 2014 BS >10 and VWF:ristocetin cofactor activity <10 U/dL were associated with the risk of bleeding, but only a BS >10 remained highly associated in a multivariable Cox proportional hazard model (adjusted hazard ratio: 7.27 [95% confidence interval, 3.83-13.83]). Ristocetin 18-28 von Willebrand factor Homo sapiens 14-17 24750681-1 2014 INTRODUCTION: The development of an automated, von Willebrand factor (VWF) activity assay, Innovance( ) VWF Ac (VWF:Ac), which measures VWF binding to the platelet receptor glycoprotein Ibalpha without ristocetin, led us to evaluate the assay for diagnosing von Willebrand disease (VWD) and monitoring therapy. Ristocetin 202-212 von Willebrand factor Homo sapiens 104-107 24705415-1 2014 von Willebrand factor/ristocetin (vWF/R) induces GPIb-dependent platelet agglutination and activation of alphaIIbbeta3 integrin, which also binds vWF. Ristocetin 22-32 von Willebrand factor Homo sapiens 34-37 24705415-1 2014 von Willebrand factor/ristocetin (vWF/R) induces GPIb-dependent platelet agglutination and activation of alphaIIbbeta3 integrin, which also binds vWF. Ristocetin 22-32 von Willebrand factor Homo sapiens 146-149 23520336-1 2013 The diagnosis of von Willebrand disease (VWD) is complicated by issues with current laboratory testing, particularly the ristocetin cofactor activity assay (VWF:RCo). Ristocetin 121-131 von Willebrand factor Homo sapiens 157-160 23789907-4 2014 vWF was determined by measuring vWF antigen (vWF:Ag) and vWF ristocetin cofactor (vWF:RCo) and by multimer analysis. Ristocetin 61-71 von Willebrand factor Homo sapiens 0-3 24296552-6 2014 VWF multimer analysis showed a loss of high-molecular-weight multimers and his plasma aggregated normal platelets under low ristocetin concentration, consistent with type 2B von Willebrand disease (VWD). Ristocetin 124-134 von Willebrand factor Homo sapiens 0-3 23730809-2 2013 The VWF activity is usually assessed based on measurement of the ristocetin cofactor (VWF:RCo). Ristocetin 65-75 von Willebrand factor Homo sapiens 4-7 23730809-2 2013 The VWF activity is usually assessed based on measurement of the ristocetin cofactor (VWF:RCo). Ristocetin 65-75 von Willebrand factor Homo sapiens 86-89 23233321-4 2013 vWF inhibition was assessed by vWF antigen level (vWF:Ag) and activity by ristocetin test (vWF:RiCo). Ristocetin 74-84 von Willebrand factor Homo sapiens 0-3 23205618-1 2013 The ristocetin cofactor assay (VWF:RCo) is the reference method for assessing von Willebrand factor (VWF) activity in the diagnosis of von Willebrand"s Disease (VWD). Ristocetin 4-14 von Willebrand factor Homo sapiens 31-34 23570742-8 2013 From the immediate post-operative phase throughout the entire observation, the VWF ristocetin cofactor activity (Rco)/antigen (Ag) ratio of patients with HeartMate II and CircuLite devices was consistently lower compared with HTx patients. Ristocetin 83-93 von Willebrand factor Homo sapiens 79-82 23107512-2 2013 Current VWF activity tests include the ristocetin cofactor assay and the collagen-binding assay (VWF:CB). Ristocetin 39-49 von Willebrand factor Homo sapiens 8-11 23205618-1 2013 The ristocetin cofactor assay (VWF:RCo) is the reference method for assessing von Willebrand factor (VWF) activity in the diagnosis of von Willebrand"s Disease (VWD). Ristocetin 4-14 von Willebrand factor Homo sapiens 78-99 23205618-1 2013 The ristocetin cofactor assay (VWF:RCo) is the reference method for assessing von Willebrand factor (VWF) activity in the diagnosis of von Willebrand"s Disease (VWD). Ristocetin 4-14 von Willebrand factor Homo sapiens 101-104 22740102-7 2012 VWF ristocetin cofactor activity (VWF:RCo) showed a median 10-fold increase 8 hours after end of infusion, while the median VWF-antigen and FVIII increase was less (5-fold and 4-fold, respectively). Ristocetin 4-14 von Willebrand factor Homo sapiens 0-3 22922961-0 2012 Simultaneous exposure of sites in von Willebrand factor for glycoprotein Ib binding and ADAMTS13 cleavage: studies with ristocetin. Ristocetin 120-130 von Willebrand factor Homo sapiens 34-55 22922961-2 2012 Because ristocetin induces VWF to bind glycoprotein Ibalpha in the absence of shear stress, we evaluated whether it could also enhance ADAMTS13 proteolysis of VWF. Ristocetin 8-18 von Willebrand factor Homo sapiens 27-30 22922961-4 2012 Ristocetin accelerated ADAMTS13 cleavage of multimeric VWF and of each of the recombinant VWF fragments except for the A2 domain lacking the ristocetin-binding site. Ristocetin 0-10 von Willebrand factor Homo sapiens 55-58 22922961-4 2012 Ristocetin accelerated ADAMTS13 cleavage of multimeric VWF and of each of the recombinant VWF fragments except for the A2 domain lacking the ristocetin-binding site. Ristocetin 0-10 von Willebrand factor Homo sapiens 90-93 22896002-2 2012 Assessment of ristocetin cofactor activity (VWF:RCo) and von Willebrand factor (VWF) antigen (VWF:Ag) in 72 consecutive patients with WM showed a negative relation between VWF levels < 130 U/dL and both monoclonal immunoglobulin M concentration (mIgMC) and viscosity. Ristocetin 14-24 von Willebrand factor Homo sapiens 44-47 22517896-4 2012 The T1255A, Clus1, and DC variants caused increased ristocetin-mediated GPIbalpha binding to VWF. Ristocetin 52-62 von Willebrand factor Homo sapiens 93-96 23043782-10 2012 According to the sequence analysis and platelet aggregation tests, we propose that the function of GPIbalpha, especially regarding the ristocetin-vWF-GPIbalpha interaction, differs between pigs and humans. Ristocetin 135-145 von Willebrand factor Homo sapiens 146-149 22740102-7 2012 VWF ristocetin cofactor activity (VWF:RCo) showed a median 10-fold increase 8 hours after end of infusion, while the median VWF-antigen and FVIII increase was less (5-fold and 4-fold, respectively). Ristocetin 4-14 von Willebrand factor Homo sapiens 34-37 22740102-7 2012 VWF ristocetin cofactor activity (VWF:RCo) showed a median 10-fold increase 8 hours after end of infusion, while the median VWF-antigen and FVIII increase was less (5-fold and 4-fold, respectively). Ristocetin 4-14 von Willebrand factor Homo sapiens 34-37 22268616-0 2012 Development of an ELISA method for testing VWF ristocetin cofactor activity with improved sensitivity and reliability in the diagnosis of von Willebrand disease. Ristocetin 47-57 von Willebrand factor Homo sapiens 43-46 22487084-3 2012 VWF activity is classically assessed by using VWF ristocetin cofactor activity (VWF:RCo), although VWF collagen-binding (VWF:CB) and VWF mAb-based (VWF activity [VWF:Act]) assays are used by some laboratories. Ristocetin 50-60 von Willebrand factor Homo sapiens 0-3 22268616-4 2012 VWF was captured by rfGPIbalpha in the presence of ristocetin, and then detected by HRP-conjugated rabbit anti-human VWF IgG. Ristocetin 51-61 von Willebrand factor Homo sapiens 0-3 21917758-9 2011 HOCl-oxidized VWF was hyperfunctional, agglutinating platelets at ristocetin concentrations that induced minimal agglutination using unoxidized VWF and binding more of the nanobody AU/VWFa-11, which detects a gain-of-function conformation of the A1 domain. Ristocetin 66-76 von Willebrand factor Homo sapiens 14-17 22232560-6 2012 A selection of compounds showing good in silico docking scores into the predicted pockets was retained for testing their in vitro effect on VWF-GPIbalpha complex formation, by which we identified a compound that surprisingly stimulated the VWF-GPIbalpha binding in a ristocetin cofactor ELISA and increased platelet adhesion in whole blood to collagen under arterial shear rate but in contrast inhibited ristocetin-induced platelet aggregation. Ristocetin 267-277 von Willebrand factor Homo sapiens 140-143 22232560-6 2012 A selection of compounds showing good in silico docking scores into the predicted pockets was retained for testing their in vitro effect on VWF-GPIbalpha complex formation, by which we identified a compound that surprisingly stimulated the VWF-GPIbalpha binding in a ristocetin cofactor ELISA and increased platelet adhesion in whole blood to collagen under arterial shear rate but in contrast inhibited ristocetin-induced platelet aggregation. Ristocetin 267-277 von Willebrand factor Homo sapiens 240-243 22232560-6 2012 A selection of compounds showing good in silico docking scores into the predicted pockets was retained for testing their in vitro effect on VWF-GPIbalpha complex formation, by which we identified a compound that surprisingly stimulated the VWF-GPIbalpha binding in a ristocetin cofactor ELISA and increased platelet adhesion in whole blood to collagen under arterial shear rate but in contrast inhibited ristocetin-induced platelet aggregation. Ristocetin 404-414 von Willebrand factor Homo sapiens 140-143 22232560-6 2012 A selection of compounds showing good in silico docking scores into the predicted pockets was retained for testing their in vitro effect on VWF-GPIbalpha complex formation, by which we identified a compound that surprisingly stimulated the VWF-GPIbalpha binding in a ristocetin cofactor ELISA and increased platelet adhesion in whole blood to collagen under arterial shear rate but in contrast inhibited ristocetin-induced platelet aggregation. Ristocetin 404-414 von Willebrand factor Homo sapiens 240-243 21951857-2 2012 The VWF activity is usually assessed based on measurement of the ristocetin cofactor (VWF:RCo). Ristocetin 65-75 von Willebrand factor Homo sapiens 4-7 21951857-2 2012 The VWF activity is usually assessed based on measurement of the ristocetin cofactor (VWF:RCo). Ristocetin 65-75 von Willebrand factor Homo sapiens 86-89 22155434-4 2012 Supportive of our hypothesis, we found remarkably high levels of factor VIII activity, Von Willebrand factor (vWF) antigen and vWF ristocetin cofactor activity (268%, 740%, 590% respectively). Ristocetin 131-141 von Willebrand factor Homo sapiens 127-130 20724302-4 2011 In the first prospective study, we demonstrate that in most cases of VWD, VWF ristocetin cofactor activity (VWF:RCo) and VWF:Act are highly correlated but that they both cannot be considered a good screening assay when used alone, since they could miss about 25% of VWF abnormalities. Ristocetin 78-88 von Willebrand factor Homo sapiens 74-77 20724302-4 2011 In the first prospective study, we demonstrate that in most cases of VWD, VWF ristocetin cofactor activity (VWF:RCo) and VWF:Act are highly correlated but that they both cannot be considered a good screening assay when used alone, since they could miss about 25% of VWF abnormalities. Ristocetin 78-88 von Willebrand factor Homo sapiens 108-111 20724302-4 2011 In the first prospective study, we demonstrate that in most cases of VWD, VWF ristocetin cofactor activity (VWF:RCo) and VWF:Act are highly correlated but that they both cannot be considered a good screening assay when used alone, since they could miss about 25% of VWF abnormalities. Ristocetin 78-88 von Willebrand factor Homo sapiens 108-111 21643680-6 2011 VWD was diagnosed by comprehensive laboratory tests including factor VIII clotting activity, von Willebrand factor antigen assay, VWF:ristocetin cofactor activity (VWF:RCo) and platelet function analyzer (PFA)-100 closure times. Ristocetin 134-144 von Willebrand factor Homo sapiens 0-3 22102188-5 2011 Laboratory testing shows low VWF:ristocetin cofactor and low or normal VWF:antigen and characteristically an enhanced ristocetin-induced platelet agglutination (RIPA). Ristocetin 33-43 von Willebrand factor Homo sapiens 29-32 21822587-2 2011 We have previously reported two monoclonal antibodies (mAbs), SZ-123 and SZ-125, which specifically bind the VWF A3 domain and block the interaction of VWF with collagen type III and ristocetin- or botrocetin-induced platelet aggregation. Ristocetin 183-193 von Willebrand factor Homo sapiens 109-112 21822587-2 2011 We have previously reported two monoclonal antibodies (mAbs), SZ-123 and SZ-125, which specifically bind the VWF A3 domain and block the interaction of VWF with collagen type III and ristocetin- or botrocetin-induced platelet aggregation. Ristocetin 183-193 von Willebrand factor Homo sapiens 152-155 22102197-4 2011 There are 103 patients with VWF ristocetin (RCo) <=50 IU/dL: 38 (37%) severe (VWF:RCo <10 IU/dL), 28 (27%) moderate (VWF:RCo 10 to 29 IU/dL), and 37 (36%) mild (VWF:RCo 30 to 50 IU/dL). Ristocetin 32-42 von Willebrand factor Homo sapiens 28-31 21148813-7 2011 As previously reported, VWF:RCo/VWF:Ag ratio was decreased with a common A1 domain polymorphism, D1472H, as was direct binding to ristocetin for a 1472H A1 loop construct. Ristocetin 130-140 von Willebrand factor Homo sapiens 24-27 21070498-1 2011 von Willebrand"s disease (VWD) is regarded as the most common congenital bleeding disorder, and although not available in all laboratories von Willebrand factor (VWF) activity is most frequently assessed as ristocetin cofactor (VWF:RCo). Ristocetin 207-217 von Willebrand factor Homo sapiens 139-160 21070498-1 2011 von Willebrand"s disease (VWD) is regarded as the most common congenital bleeding disorder, and although not available in all laboratories von Willebrand factor (VWF) activity is most frequently assessed as ristocetin cofactor (VWF:RCo). Ristocetin 207-217 von Willebrand factor Homo sapiens 162-165 21186048-0 2011 A rapid, automated VWF ristocetin cofactor activity assay improves reliability in the diagnosis of Von Willebrand disease. Ristocetin 23-33 von Willebrand factor Homo sapiens 19-22 20738304-4 2010 In a multiple stepwise regression model, age- and sex-adjusted PFA-100 ADP and VWF ristocetin cofactor activity (VWF:RCo) were independently associated with BS. Ristocetin 83-93 von Willebrand factor Homo sapiens 79-82 21193108-3 2011 The classification is based on phenotypic assays including FVIII, VWF:Ag and VWF activity, typically by ristocetin cofactor (VWF:RCo), but also increasingly by collagen binding (VWF:CB). Ristocetin 104-114 von Willebrand factor Homo sapiens 77-80 21193108-3 2011 The classification is based on phenotypic assays including FVIII, VWF:Ag and VWF activity, typically by ristocetin cofactor (VWF:RCo), but also increasingly by collagen binding (VWF:CB). Ristocetin 104-114 von Willebrand factor Homo sapiens 77-80 21193108-3 2011 The classification is based on phenotypic assays including FVIII, VWF:Ag and VWF activity, typically by ristocetin cofactor (VWF:RCo), but also increasingly by collagen binding (VWF:CB). Ristocetin 104-114 von Willebrand factor Homo sapiens 77-80 20589372-0 2010 Ristocetin-induced self-aggregation of von Willebrand factor. Ristocetin 0-10 von Willebrand factor Homo sapiens 39-60 20589372-3 2010 Ristocetin also promotes the interaction of VWF with GpIb and is able to induce platelet aggregation, and thus is largely used to mimic this effect in vitro. Ristocetin 0-10 von Willebrand factor Homo sapiens 44-47 20589372-4 2010 In this research paper, we followed the time course of VWF self-association in solution induced by ristocetin binding by light scattering and at the same time we collected atomic force microscopy images to clarify the nature of the assembly that is formed. Ristocetin 99-109 von Willebrand factor Homo sapiens 55-58 20738304-4 2010 In a multiple stepwise regression model, age- and sex-adjusted PFA-100 ADP and VWF ristocetin cofactor activity (VWF:RCo) were independently associated with BS. Ristocetin 83-93 von Willebrand factor Homo sapiens 113-116 20727070-3 2010 RESULTS: Addition of extra ristocetin resulted in improved measurement of VWF recoveries from various VWF-containing concentrates that were underestimated using the standard automated protocol. Ristocetin 28-38 von Willebrand factor Homo sapiens 75-78 20727070-3 2010 RESULTS: Addition of extra ristocetin resulted in improved measurement of VWF recoveries from various VWF-containing concentrates that were underestimated using the standard automated protocol. Ristocetin 28-38 von Willebrand factor Homo sapiens 103-106 19647361-0 2009 Kinetic study of von Willebrand factor self-aggregation induced by ristocetin. Ristocetin 67-77 von Willebrand factor Homo sapiens 17-38 20979592-6 2010 Platelet adhesion to ristocetin-activated VWF was studied in the presence of reduced beta(2) GPI. Ristocetin 21-31 von Willebrand factor Homo sapiens 42-45 20231421-0 2010 Common VWF exon 28 polymorphisms in African Americans affecting the VWF activity assay by ristocetin cofactor. Ristocetin 90-100 von Willebrand factor Homo sapiens 7-10 20231421-0 2010 Common VWF exon 28 polymorphisms in African Americans affecting the VWF activity assay by ristocetin cofactor. Ristocetin 90-100 von Willebrand factor Homo sapiens 68-71 20231421-7 2010 Because the VWF:RCo assay depends on ristocetin binding to VWF, mutations (and polymorphisms) in VWF may affect the measurement of "VWF activity" by this assay and may not reflect a functional defect or true hemorrhagic risk. Ristocetin 37-47 von Willebrand factor Homo sapiens 12-15 20216992-6 2010 We conclude that the NTF change induced by 0/37 degrees C incubation reflects clustering of GPIbalpha supports VWF/ristocetin-induced agglutination and spreading and is sufficient to initiate platelet activation in the absence of VWF. Ristocetin 115-125 von Willebrand factor Homo sapiens 111-114 20179578-9 2010 Activities determined with HemosIL vWF:activity had good correlation with those determined as ristocetin cofactor, Imubind (vWF:Imubind) and collagen-binding. Ristocetin 94-104 von Willebrand factor Homo sapiens 35-38 20179578-11 2010 This automated HemosIL vWF:activity test could be included in routine determination of vWF activity in concentrate samples and supports traditional von Willebrand ristocetin cofactor because it is reliable, reproducible and sensitive. Ristocetin 163-173 von Willebrand factor Homo sapiens 23-26 19633908-5 2010 We measured the plasma concentration of von-Willebrand-factor-antigen (VWF:Ag), the activity of von-Willebrand-factor-Ristocetin-Cofactor (VWF:RiCo) and FVIII at several stress-levels and consecutively split up the different VWF-multimers. Ristocetin 118-128 von Willebrand factor Homo sapiens 96-117 20443704-9 2010 In vitro functional studies revealed that the chimeric antibody and its Fab fragment prevented platelet adhesion to VWF under high shear stress and inhibited ristocetin-induced platelet aggregation in a dose-dependent manner. Ristocetin 158-168 von Willebrand factor Homo sapiens 116-119 19811543-1 2010 The efficacy of highly purified VWF/FVIII concentrates with standardized ristocetin cofactor content (VWF:RCo) has been already proven in patients with von Willebrand"s disease (VWD). Ristocetin 73-83 von Willebrand factor Homo sapiens 32-35 19811543-1 2010 The efficacy of highly purified VWF/FVIII concentrates with standardized ristocetin cofactor content (VWF:RCo) has been already proven in patients with von Willebrand"s disease (VWD). Ristocetin 73-83 von Willebrand factor Homo sapiens 102-105 19694940-0 2009 Limitations of the ristocetin cofactor assay in measurement of von Willebrand factor function. Ristocetin 19-29 von Willebrand factor Homo sapiens 63-84 19694940-1 2009 BACKGROUND: Type 2M von Willebrand disease (VWD) is characterized by a qualitative defect in von Willebrand factor (VWF) and diagnosed by a disproportionate decrease in VWF ristocetin cofactor activity (VWF:RCo) as compared with VWF antigen (VWF:Ag). Ristocetin 173-183 von Willebrand factor Homo sapiens 169-172 19694940-1 2009 BACKGROUND: Type 2M von Willebrand disease (VWD) is characterized by a qualitative defect in von Willebrand factor (VWF) and diagnosed by a disproportionate decrease in VWF ristocetin cofactor activity (VWF:RCo) as compared with VWF antigen (VWF:Ag). Ristocetin 173-183 von Willebrand factor Homo sapiens 169-172 19694940-1 2009 BACKGROUND: Type 2M von Willebrand disease (VWD) is characterized by a qualitative defect in von Willebrand factor (VWF) and diagnosed by a disproportionate decrease in VWF ristocetin cofactor activity (VWF:RCo) as compared with VWF antigen (VWF:Ag). Ristocetin 173-183 von Willebrand factor Homo sapiens 169-172 19694940-1 2009 BACKGROUND: Type 2M von Willebrand disease (VWD) is characterized by a qualitative defect in von Willebrand factor (VWF) and diagnosed by a disproportionate decrease in VWF ristocetin cofactor activity (VWF:RCo) as compared with VWF antigen (VWF:Ag). Ristocetin 173-183 von Willebrand factor Homo sapiens 169-172 19694940-2 2009 OBJECTIVE: We report here on the spurious diagnosis of VWD in a patient with a sequence variation in the ristocetin-binding domain of VWF. Ristocetin 105-115 von Willebrand factor Homo sapiens 134-137 19694940-6 2009 RESULTS: Studies with recombinant VWF showed normal platelet binding with botrocetin, but a significant decrease in binding in response to ristocetin. Ristocetin 139-149 von Willebrand factor Homo sapiens 34-37 19694940-9 2009 CONCLUSIONS: The decreased VWF:RCo seen with the P1467S sequence variation likely represents an artifact as a result of the use of ristocetin to measure VWF activity. Ristocetin 131-141 von Willebrand factor Homo sapiens 27-30 19694940-9 2009 CONCLUSIONS: The decreased VWF:RCo seen with the P1467S sequence variation likely represents an artifact as a result of the use of ristocetin to measure VWF activity. Ristocetin 131-141 von Willebrand factor Homo sapiens 153-156 20635317-5 2010 The specific activity for binding to collagen and platelets mediated by ristocetin is higher in rVWF than in commercial plasma-derived VWF-FVIII complex products. Ristocetin 72-82 von Willebrand factor Homo sapiens 97-100 19875727-6 2009 MP-P also promoted GPIb-IX association with the membrane skeleton, and inhibited ristocetin-induced platelet agglutination, VWF binding to platelets and platelet adhesion to immobilized VWF. Ristocetin 81-91 von Willebrand factor Homo sapiens 186-189 19875727-7 2009 Furthermore, a GPIb-IX mutant replacing Ser559 of GPIbalpha with alanine showed an enhanced association with the membrane skeleton, reduced ristocetin-induced VWF binding, and diminished ability to mediate cell adhesion to VWF under flow conditions. Ristocetin 140-150 von Willebrand factor Homo sapiens 159-162 19647361-3 2009 Likewise, the binding of the glycopeptide antibiotic ristocetin to VWF triggers hemostatically relevant conformational transitions. Ristocetin 53-63 von Willebrand factor Homo sapiens 67-70 19647361-5 2009 In this study we investigated by a combined approach of light scattering spectroscopy and turbidimetry the ability of VWF to self-associate in solution in the presence of ristocetin and in the absence of any protein adsorbing surface. Ristocetin 171-181 von Willebrand factor Homo sapiens 118-121 19506360-3 2009 Typical laboratory features of VWD type 2 M are decreased ristocetin-induced platelet aggregation in the presence of a normal or near normal VWF multimeric pattern on a low-resolution agarose gel, a poor response to desmopressin (DDAVP) of VWF:RCo, and a good response of both VWF:CB and VWF:Ag to DDAVP. Ristocetin 58-68 von Willebrand factor Homo sapiens 240-243 19497443-5 2009 RESULTS: The von Willebrand factor (vWF)-dependent ristocetin-induced platelet aggregation was impaired in 11 of the 16 patients, of which 12 had experienced at least 1 minor or major bleeding episode. Ristocetin 51-61 von Willebrand factor Homo sapiens 13-34 19497443-5 2009 RESULTS: The von Willebrand factor (vWF)-dependent ristocetin-induced platelet aggregation was impaired in 11 of the 16 patients, of which 12 had experienced at least 1 minor or major bleeding episode. Ristocetin 51-61 von Willebrand factor Homo sapiens 36-39 19497443-6 2009 The impaired ristocetin-induced platelet aggregation was associated both with decreased specific activity of plasma vWF, presumably due to lack of high molecular weight vWF multimers, as well as with attenuated function of the platelets themselves. Ristocetin 13-23 von Willebrand factor Homo sapiens 116-119 19497443-6 2009 The impaired ristocetin-induced platelet aggregation was associated both with decreased specific activity of plasma vWF, presumably due to lack of high molecular weight vWF multimers, as well as with attenuated function of the platelets themselves. Ristocetin 13-23 von Willebrand factor Homo sapiens 169-172 19506359-4 2009 There is a good response to desmopressin (DDAVP) followed by rapid clearance of VWF:antigen (Ag), factor VIII coagulant activity (FVIII:C) and VWF:ristocetin cofactor activity (RCo) as the main cause of VWD type 1 or 2 with typical 2E multimeric pattern (VWD type 1/2E). Ristocetin 147-157 von Willebrand factor Homo sapiens 143-146 19506360-3 2009 Typical laboratory features of VWD type 2 M are decreased ristocetin-induced platelet aggregation in the presence of a normal or near normal VWF multimeric pattern on a low-resolution agarose gel, a poor response to desmopressin (DDAVP) of VWF:RCo, and a good response of both VWF:CB and VWF:Ag to DDAVP. Ristocetin 58-68 von Willebrand factor Homo sapiens 240-243 19506360-3 2009 Typical laboratory features of VWD type 2 M are decreased ristocetin-induced platelet aggregation in the presence of a normal or near normal VWF multimeric pattern on a low-resolution agarose gel, a poor response to desmopressin (DDAVP) of VWF:RCo, and a good response of both VWF:CB and VWF:Ag to DDAVP. Ristocetin 58-68 von Willebrand factor Homo sapiens 240-243 18600088-9 2008 Plasma von Willebrand factor levels were measured as ristocetin-cofactor activities. Ristocetin 53-63 von Willebrand factor Homo sapiens 7-28 19110525-4 2008 Ristocetin-cofactor activity (VWF: RCo) was between 7% and 14% by measurement with von Willebrand reagent (Dade Behring, Marburg, Germany). Ristocetin 0-10 von Willebrand factor Homo sapiens 30-33 18637125-5 2008 In vitro mutagenesis and expression in COS-7 cells confirmed the impairment of the mutant in botrocetin- and ristocetin-mediated VWF binding to GPIb. Ristocetin 109-119 von Willebrand factor Homo sapiens 129-132 18786009-6 2008 The HMW VWF multimer pattern in Haemate P/Humate-P is more similar to that of normal human plasma (94% for Haemate P/Humate-P vs. 100% for normal human plasma) than that of other VWF/FVIII concentrates and correlates with functional VWF activities including ristocetin cofactor activity (VWF:RCo) and collagen-binding activity. Ristocetin 258-268 von Willebrand factor Homo sapiens 8-11 18786010-5 2008 FVIII level and VWF ristocetin cofactor activity may both be used to determine concentrate potency and to monitor treatment. Ristocetin 20-30 von Willebrand factor Homo sapiens 16-19 18845909-3 2008 In this assay, fixed platelets bound to the vWF-R497 mutant, carrying the deletion of Glu497-Tyr508 and the missense mutation of Arg545 to Ala, without binding modulators such as ristocetin. Ristocetin 179-189 von Willebrand factor Homo sapiens 44-47 18485089-8 2008 VWF/ristocetin-mediated activation of the sGC/cGMP signaling pathway may contribute to feedback platelet inhibition. Ristocetin 4-14 von Willebrand factor Homo sapiens 0-3 18637125-0 2008 N1421K mutation in the glycoprotein Ib binding domain impairs ristocetin- and botrocetin-mediated binding of von Willebrand factor to platelets. Ristocetin 62-72 von Willebrand factor Homo sapiens 109-130 18637125-4 2008 Botrocetin- and ristocetin-mediated binding of plasma VWF to GPIb were reduced in the patients. Ristocetin 16-26 von Willebrand factor Homo sapiens 54-57 17786534-3 2008 METHODS: The aim of this study was to explore the correlation between VWF:Ag, VWF ristocetin cofactor activity (VWF:RCo) and FVIII in 213 consecutive patients undergoing screening for VWD. Ristocetin 82-92 von Willebrand factor Homo sapiens 78-81 17786534-3 2008 METHODS: The aim of this study was to explore the correlation between VWF:Ag, VWF ristocetin cofactor activity (VWF:RCo) and FVIII in 213 consecutive patients undergoing screening for VWD. Ristocetin 82-92 von Willebrand factor Homo sapiens 78-81 18445014-6 2008 In this group, pre-infusion FVIII:C, VWF:Ag and VWF: ristocetin cofactor (RCoF) level that were 19.5% (1-64), 20 U dL(-1) (0-96) and 12% (0-66) increased to 72% (54-198), 131 U dL(-1) (68-206) and 68% (27-108) postinfusion, respectively. Ristocetin 53-63 von Willebrand factor Homo sapiens 48-51 18521510-4 2008 VWF/ristocetin-induced platelet aggregation was delayed after treatment with methyl beta-cyclodextrin (mbCD), but the maximal aggregation response was not affected. Ristocetin 4-14 von Willebrand factor Homo sapiens 0-3 18282712-14 2008 Indeed, collagen binding capacity and ristocetin cofactor activity (which measures binding of VWF to platelets) were lower in VAD patients compared to HTX recipients. Ristocetin 38-48 von Willebrand factor Homo sapiens 94-97 17977030-0 2008 Evidence from limited proteolysis of a ristocetin-induced conformational change in human von Willebrand factor that promotes its binding to platelet glycoprotein Ib-IX-V. von Willebrand factor (VWF) does not normally interact with platelets in the bloodstream. Ristocetin 39-49 von Willebrand factor Homo sapiens 89-110 17977030-0 2008 Evidence from limited proteolysis of a ristocetin-induced conformational change in human von Willebrand factor that promotes its binding to platelet glycoprotein Ib-IX-V. von Willebrand factor (VWF) does not normally interact with platelets in the bloodstream. Ristocetin 39-49 von Willebrand factor Homo sapiens 171-192 17977030-0 2008 Evidence from limited proteolysis of a ristocetin-induced conformational change in human von Willebrand factor that promotes its binding to platelet glycoprotein Ib-IX-V. von Willebrand factor (VWF) does not normally interact with platelets in the bloodstream. Ristocetin 39-49 von Willebrand factor Homo sapiens 194-197 17977030-3 2008 Ristocetin also promotes interaction of VWF with GP Ib-IX-V; it thus provides a model for changes in VWF conformation and function that may occur in vivo. Ristocetin 0-10 von Willebrand factor Homo sapiens 40-43 17977030-3 2008 Ristocetin also promotes interaction of VWF with GP Ib-IX-V; it thus provides a model for changes in VWF conformation and function that may occur in vivo. Ristocetin 0-10 von Willebrand factor Homo sapiens 101-104 17977030-5 2008 Ristocetin markedly altered the pattern of VWF digestion by trypsin, increasing the prevalence of two major proteolytic fragments (109 and 160 kDa), and decreasing that of four fragments (130, 145, 181 and 199 kDa). Ristocetin 0-10 von Willebrand factor Homo sapiens 43-46 17977030-8 2008 Changes in prevalence of five of the tryptic fragments of VWF with ristocetin and vancomycin correlated closely with changes in VWF binding to GP Ib-IX-V. Heparin also partially inhibited the ristocetin-induced changes in tryptic digestion of VWF. Ristocetin 67-77 von Willebrand factor Homo sapiens 58-61 17977030-8 2008 Changes in prevalence of five of the tryptic fragments of VWF with ristocetin and vancomycin correlated closely with changes in VWF binding to GP Ib-IX-V. Heparin also partially inhibited the ristocetin-induced changes in tryptic digestion of VWF. Ristocetin 192-202 von Willebrand factor Homo sapiens 58-61 17977030-8 2008 Changes in prevalence of five of the tryptic fragments of VWF with ristocetin and vancomycin correlated closely with changes in VWF binding to GP Ib-IX-V. Heparin also partially inhibited the ristocetin-induced changes in tryptic digestion of VWF. Ristocetin 192-202 von Willebrand factor Homo sapiens 128-131 17977030-8 2008 Changes in prevalence of five of the tryptic fragments of VWF with ristocetin and vancomycin correlated closely with changes in VWF binding to GP Ib-IX-V. Heparin also partially inhibited the ristocetin-induced changes in tryptic digestion of VWF. Ristocetin 192-202 von Willebrand factor Homo sapiens 128-131 17977030-9 2008 These observations suggest that ristocetin may modulate VWF conformation in such a way as to expose its GP Ib-binding domain and enable it to interact with the platelet. Ristocetin 32-42 von Willebrand factor Homo sapiens 56-59 18312368-3 2008 Rise in ristocetin cofactor activity (VWF:RCo) > or = 40% at 90-min post-Stimate and 1-2 h after subcutaneous DDAVP was defined as initial response; response longevity was assessed only after subcutaneous dosing by measuring VWF:RCo levels at time-points 1, 2, 4 and 6 h. Eleven patients (five males, six females; age range: 20-56 years) participated in intranasal and 9/11 (four males, five females) in subcutaneous testing. Ristocetin 8-18 von Willebrand factor Homo sapiens 38-41 18055988-11 2007 INTERPRETATION AND CONCLUSIONS: The measurement of ristocetin-induced binding of VWF to platelets by flow cytometry is a sensitive, simple and rapid test for the diagnosis of VWD and for the monitoring of the effects of desmopressin therapy. Ristocetin 51-61 von Willebrand factor Homo sapiens 81-84 18327408-10 2008 This effect is likely to be mediated through VWF as Mg(++) partially inhibited ristocetin-induced platelet aggregation and VWF binding to collagen. Ristocetin 79-89 von Willebrand factor Homo sapiens 45-48 18055988-4 2007 DESIGN AND METHODS: Flow cytometric analysis of ristocetin-induced VWF binding to platelets was performed in platelet-rich plasma (PRP) samples from patients with VWD and from control subjects and in samples of formalin-fixed platelets in the presence of plasma from patients or controls. Ristocetin 48-58 von Willebrand factor Homo sapiens 67-70 18055988-7 2007 RESULTS: Ristocetin-induced VWF binding to platelets, evaluated by both flow cytometry-based assays, was significantly reduced in patients with type1, 2A and 2M VWD as compared with that in healthy subjects. Ristocetin 9-19 von Willebrand factor Homo sapiens 28-31 18064311-6 2007 Recombinant VWF carrying the I1372S mutation and showing a normal VWF multimer organisation was capable of inducing SPA on normal platelet-rich plasma (unlike wild-type VWF), as well as a hyper-response to ristocetin in the same platelets (0.6 mg/ml ristocetin vs. 1.2 of wild-type VWF). Ristocetin 206-216 von Willebrand factor Homo sapiens 12-15 18064311-6 2007 Recombinant VWF carrying the I1372S mutation and showing a normal VWF multimer organisation was capable of inducing SPA on normal platelet-rich plasma (unlike wild-type VWF), as well as a hyper-response to ristocetin in the same platelets (0.6 mg/ml ristocetin vs. 1.2 of wild-type VWF). Ristocetin 250-260 von Willebrand factor Homo sapiens 12-15 18064311-7 2007 The new I1372S VWF mutation, characterized by SPA and hyper-responsiveness to ristocetin thus has some of the features of type 2B VWD, but not the lack of large VWF multimers, so we defined this variant as type 2B-like VWD. Ristocetin 78-88 von Willebrand factor Homo sapiens 15-18 17389010-7 2007 The A2 domain polypeptide specifically recognizes the GPIbalpha-binding conformation in the A1 domain, as it only interacted with VWF activated by the modulator ristocetin or immobilized VWF. Ristocetin 161-171 von Willebrand factor Homo sapiens 130-133 17578514-3 2007 Binding of VWF in solution to immobilized A/C was inhibited by ristocetin and preincubation of platelets with A/C abolished ristocetin/VWF-induced platelet aggregation, indicating that the interaction of A/C with VWF is mediated by the VWA1 domain. Ristocetin 63-73 von Willebrand factor Homo sapiens 11-14 17578514-3 2007 Binding of VWF in solution to immobilized A/C was inhibited by ristocetin and preincubation of platelets with A/C abolished ristocetin/VWF-induced platelet aggregation, indicating that the interaction of A/C with VWF is mediated by the VWA1 domain. Ristocetin 124-134 von Willebrand factor Homo sapiens 11-14 17439628-6 2007 Median in vivo recovery of VWF ristocetin cofactor (VWF:RCo) was 1.9 IU dL(-1) (IU kg(-1))(-1) with an interquartile range (IQR) of 1.6-2.5 IU dL(-1) (IU kg(-1))(-1). Ristocetin 31-41 von Willebrand factor Homo sapiens 27-30 17439628-6 2007 Median in vivo recovery of VWF ristocetin cofactor (VWF:RCo) was 1.9 IU dL(-1) (IU kg(-1))(-1) with an interquartile range (IQR) of 1.6-2.5 IU dL(-1) (IU kg(-1))(-1). Ristocetin 31-41 von Willebrand factor Homo sapiens 52-55 17549293-6 2007 The subjects received a single infusion of 60 IU/kg ristocetin cofactor activity (VWF:RCo) of either AHF (High Purity) or Biostate, and after a minimum 15-day wash-out period they received the alternative product. Ristocetin 52-62 von Willebrand factor Homo sapiens 82-89 17403090-3 2007 METHODS AND RESULTS: Fifty patients with clinically severe VWD (72% had VWF ristocetin cofactor activity less than 10 IU dL(-1) and 46% had FVIII < 20 IU dL(-1)) were treated with the concentrate as the only therapy, except for clinical situations requiring a priming dose of FVIII to rapidly correct an intrinsic coagulation defect. Ristocetin 76-86 von Willebrand factor Homo sapiens 72-75 17598011-5 2007 Remarkably, when compared to VWF of A/T1381 and A/A1381 individuals, VWF of individuals carrying the T/T1381 variant showed an increased affinity for its platelet receptor GPIbalpha under static conditions, as reflected by an increased sensitivity to low concentrations of ristocetin or botrocetin. Ristocetin 273-283 von Willebrand factor Homo sapiens 69-72 17200766-7 2007 VWF activity was determined using both the ristocetin cofactor activity (VWF:Rcof) and collagen binding (VWF:CB) assays. Ristocetin 43-53 von Willebrand factor Homo sapiens 0-3 17137472-5 2007 Among the 49 cases who were tested for VWF, low values by three measures were more commonly present than in 166 controls, specifically, ristocetin cofactor (RCo) activity [20.4% vs. 5.4%, odds ratio (OR) 4.5], collagen binding (14.3% vs. 4.2%, OR 3.8), and antigen level (20.4% vs. 6.0%, OR 4.0). Ristocetin 136-146 von Willebrand factor Homo sapiens 39-42 17701477-4 2007 The ristocetin cofactor activity (VWF:RCo) is the most useful test for VWD diagnosis, because it can mimic the interactions of VWF with its platelet receptor. Ristocetin 4-14 von Willebrand factor Homo sapiens 34-37 17701477-4 2007 The ristocetin cofactor activity (VWF:RCo) is the most useful test for VWD diagnosis, because it can mimic the interactions of VWF with its platelet receptor. Ristocetin 4-14 von Willebrand factor Homo sapiens 127-130 16862517-4 2006 In the early 1970s, ristocetin-induced platelet aggregation was described and formed the basis of the first consistent and reliable test that quantified the platelet adhesive function missing in vWD. Ristocetin 20-30 von Willebrand factor Homo sapiens 195-198 16977573-7 2006 The specific vWF activities, as assessed by ristocetin cofactor activity (vWF:RCo) and collagen-binding activity (vWF:CB), correlated well with the HMWvWF content of the products. Ristocetin 44-54 von Willebrand factor Homo sapiens 13-16 16977566-5 2006 The ristocetin cofactor activity is the most useful test for VWD screening in the general population because it reproduces in vitro the first VWF interactions with its platelet receptor; however other assays are required to identify and classify VWD types. Ristocetin 4-14 von Willebrand factor Homo sapiens 142-145 16862522-6 2006 Several different techniques were used for determination of vWF ristocetin cofactor activity (vWF:RCo), all of which were associated with poor agreement among centers as indicated by CVs of 40 to 50%. Ristocetin 64-74 von Willebrand factor Homo sapiens 60-63 16862522-6 2006 Several different techniques were used for determination of vWF ristocetin cofactor activity (vWF:RCo), all of which were associated with poor agreement among centers as indicated by CVs of 40 to 50%. Ristocetin 64-74 von Willebrand factor Homo sapiens 94-97 16607078-3 2006 In samples from healthy individuals (n=10) and in patients with suspected type 1 VWD (n=10), storage of whole blood on ice caused a drastic time-dependent decrease in von Willebrand factor (VWF):ristocetin cofactor activity, in VWF:antigen activity and factor VIII activity (mean+/-SD) to 35+/-18, 55+/-23 and 53+/-15% of baseline levels after 6 h storage, respectively. Ristocetin 195-205 von Willebrand factor Homo sapiens 167-188 16706984-0 2006 von Willebrand factor mediates platelet spreading through glycoprotein Ib and alpha(IIb)beta3 in the presence of botrocetin and ristocetin, respectively. Ristocetin 128-138 von Willebrand factor Homo sapiens 0-21 16706984-3 2006 OBJECTIVE: To evaluate the ability of GPIb and alpha(IIb)beta3 to mediate platelet adhesion and lamellipodia formation on immobilized VWF in the presence of the biochemical modulators, ristocetin and botrocetin. Ristocetin 185-195 von Willebrand factor Homo sapiens 134-137 16706984-6 2006 In marked contrast, in the presence of ristocetin, VWF stimulates formation of fully spread lamellipodia through a pathway that is dependent upon alpha(IIb)beta3 and PI3-kinase. Ristocetin 39-49 von Willebrand factor Homo sapiens 51-54 16706984-9 2006 Interestingly, botrocetin significantly enhances platelet adhesion to VWF under flow in whole blood in an alpha(IIb)beta3-independent manner, while ristocetin augments washed platelet adhesion and spreading to VWF under flow in an alpha(IIb)beta3-dependent manner. Ristocetin 148-158 von Willebrand factor Homo sapiens 210-213 16420575-4 2006 RESULTS: The A1 domain bound to collagen with K(d) approximately 8.0 nm and this binding was blocked by the mAb 6G1, which blocks the interaction between ristocetin and VWF. Ristocetin 154-164 von Willebrand factor Homo sapiens 169-172 16704443-2 2006 This feature is usually studied in vitro by a ristocetin-dependent VWF platelet-binding assay, which has some limitations as it requires [e.g. (radio)-labelled anti-VWF antibodies and normal formaldehyde-fixed platelets]. Ristocetin 46-56 von Willebrand factor Homo sapiens 67-70 16704443-3 2006 We, here, extended the applicability of an enzyme-linked immunosorbent assay-based method previously described for the measurement of ristocetin co-factor activity that used a recombinant fragment of GPIb (rfGPIb alpha) and horseradish peroxidase-labelled rabbit anti-human VWF antibodies for measuring the captured ristocetin-VWF complexes on the rfGPIb alpha. Ristocetin 134-144 von Willebrand factor Homo sapiens 274-277 16704443-3 2006 We, here, extended the applicability of an enzyme-linked immunosorbent assay-based method previously described for the measurement of ristocetin co-factor activity that used a recombinant fragment of GPIb (rfGPIb alpha) and horseradish peroxidase-labelled rabbit anti-human VWF antibodies for measuring the captured ristocetin-VWF complexes on the rfGPIb alpha. Ristocetin 134-144 von Willebrand factor Homo sapiens 327-330 16704443-5 2006 VWF in plasma from 28 of these patients bound better than normal VWF at 0.2 mg/ml ristocetin, with the ratio, optical density (OD) patient/OD normal pool plasma, higher than 1.8. Ristocetin 82-92 von Willebrand factor Homo sapiens 0-3 16704443-5 2006 VWF in plasma from 28 of these patients bound better than normal VWF at 0.2 mg/ml ristocetin, with the ratio, optical density (OD) patient/OD normal pool plasma, higher than 1.8. Ristocetin 82-92 von Willebrand factor Homo sapiens 65-68 17047284-6 2006 ULVWF is also significantly more potent than P-VWF in mediating both shear-induced platelet aggregation and ristocetin-mediated platelet agglutination. Ristocetin 108-118 von Willebrand factor Homo sapiens 2-5 16607078-3 2006 In samples from healthy individuals (n=10) and in patients with suspected type 1 VWD (n=10), storage of whole blood on ice caused a drastic time-dependent decrease in von Willebrand factor (VWF):ristocetin cofactor activity, in VWF:antigen activity and factor VIII activity (mean+/-SD) to 35+/-18, 55+/-23 and 53+/-15% of baseline levels after 6 h storage, respectively. Ristocetin 195-205 von Willebrand factor Homo sapiens 190-193 16320153-0 2005 Impact of the Thr789Ala variant of the von Willebrand factor levels, on ristocetin co-factor and collagen binding capacity and its association with coronary heart disease in patients with diabetes mellitus type 2. Ristocetin 72-82 von Willebrand factor Homo sapiens 39-60 16430944-7 2006 The test is based on the measurement of the ristocetin-cofactor activity of purified, urea-denaturated vWF concentrate after incubation with diluted patient plasma that has been preactivated with barium chloride. Ristocetin 44-54 von Willebrand factor Homo sapiens 103-106 16320153-7 2005 In addition, ristocetin co-factor was significantly increased in vWF Thr789Ala variant carriers (p < 0.05). Ristocetin 13-23 von Willebrand factor Homo sapiens 65-68 16320153-10 2005 In conclusion, although the Thr789Ala vWF gene variant is associated with increased plasma concentrations of vWF, ristocetin co factor levels and collagen binding capacity in patients with type 2 diabetes and CHD, a direct effect of this variant on the occurrence of CHD in patients with type 2 diabetes, could not be detected. Ristocetin 114-124 von Willebrand factor Homo sapiens 38-41 16014562-3 2005 AU/VWFa-11 is unable to bind VWF in solution, but efficiently interacts with ristocetin- or botrocetin-activated VWF, VWF comprising type 2B mutation R1306Q, or immobilized VWF. Ristocetin 77-87 von Willebrand factor Homo sapiens 3-6 15941906-4 2005 MPalphaC also inhibited VWF-dependent platelet agglutination induced by ristocetin. Ristocetin 72-82 von Willebrand factor Homo sapiens 24-27 15705799-7 2005 Analysis of ristocetin-mediated (125)I-VWF binding showed that the Mut receptor binds VWF in the absence of ristocetin and displays an increased sensitivity to lower concentrations of the modulator. Ristocetin 12-22 von Willebrand factor Homo sapiens 39-42 15809291-7 2005 Ristocetin binding to VWF could reduce the apparent affinity and reverse the inhibitory effect of chloride. Ristocetin 0-10 von Willebrand factor Homo sapiens 22-25 15705799-7 2005 Analysis of ristocetin-mediated (125)I-VWF binding showed that the Mut receptor binds VWF in the absence of ristocetin and displays an increased sensitivity to lower concentrations of the modulator. Ristocetin 12-22 von Willebrand factor Homo sapiens 86-89 15886805-8 2005 To help elucidate the binding site within the A1 domain, binding of ristocetin-treated VWF to the immobilized lambda dimer protein was assayed in the presence of various anti-A1 domain monoclonal antibodies. Ristocetin 68-78 von Willebrand factor Homo sapiens 87-90 15886805-6 2005 The lambda dimer protein inhibited the binding of platelets to immobilized or ristocetin-treated von Willebrand factor (VWF). Ristocetin 78-88 von Willebrand factor Homo sapiens 97-118 15886805-6 2005 The lambda dimer protein inhibited the binding of platelets to immobilized or ristocetin-treated von Willebrand factor (VWF). Ristocetin 78-88 von Willebrand factor Homo sapiens 120-123 15886805-7 2005 Furthermore, a 39/34 kD fragment of VWF encompassing the A1 domain specifically bound to the immobilized lambda dimer protein in the presence of ristocetin, suggesting that the lambda dimer protein directly binds to the A1 domain of VWF. Ristocetin 145-155 von Willebrand factor Homo sapiens 36-39 15946221-0 2005 Endothelial microparticles induce formation of platelet aggregates via a von Willebrand factor/ristocetin dependent pathway, rendering them resistant to dissociation. Ristocetin 95-105 von Willebrand factor Homo sapiens 73-94 16024332-6 2005 On average, type 1 VWD plasma was misidentified as type 2 VWD plasma in 11% of cases, and laboratories that performed the ristocetin cofactor assay for von Willebrand factor (VWF:RCo) without performing the collagen-binding activity assay for VWF (VWF:CB) were 6 times more likely to make such an error than those that did perform the VWF:CB. Ristocetin 122-132 von Willebrand factor Homo sapiens 152-173 15459008-3 2005 In the present study, we demonstrated that the addition of VWF/factor VIII complex or purified VWF (> 2 ristocetin cofactor activity units/mL) increased platelet adhesion to the collagen surface in platelet-reduced blood ( approximately 5 x 10(4) platelets/microL) to the normal level. Ristocetin 107-117 von Willebrand factor Homo sapiens 59-62 15459008-3 2005 In the present study, we demonstrated that the addition of VWF/factor VIII complex or purified VWF (> 2 ristocetin cofactor activity units/mL) increased platelet adhesion to the collagen surface in platelet-reduced blood ( approximately 5 x 10(4) platelets/microL) to the normal level. Ristocetin 107-117 von Willebrand factor Homo sapiens 95-98 15849522-5 2005 Study results have shown that the commercially available VWF-containing concentrates are effective in clinical practice (bleeding and surgery), producing responses that may differ depending on the patient"s VWD subtype; infusion results in correction of factor VIII activity (FVIII:C) and ristocetin cofactor activity of VWF (VWF:RCo), whereas bleeding time is not consistently corrected. Ristocetin 289-299 von Willebrand factor Homo sapiens 57-60 16024332-6 2005 On average, type 1 VWD plasma was misidentified as type 2 VWD plasma in 11% of cases, and laboratories that performed the ristocetin cofactor assay for von Willebrand factor (VWF:RCo) without performing the collagen-binding activity assay for VWF (VWF:CB) were 6 times more likely to make such an error than those that did perform the VWF:CB. Ristocetin 122-132 von Willebrand factor Homo sapiens 175-178 15630508-1 2005 We have previously demonstrated that the von Willebrand factor ristocetin cofactor activity (VWF:RCo), used in the diagnosis of vonWillebrand disease (VWD), can be accurately determined via ELISA by measuring the ristocetin-induced binding of VWF to a captured recombinant fragment of GPIbalpha (rfGPIbalpha, AA 1-289) (Vanhoorelbeke et al., Thromb Haemost 2000; 83: 107-13). Ristocetin 63-73 von Willebrand factor Homo sapiens 93-96 15630508-1 2005 We have previously demonstrated that the von Willebrand factor ristocetin cofactor activity (VWF:RCo), used in the diagnosis of vonWillebrand disease (VWD), can be accurately determined via ELISA by measuring the ristocetin-induced binding of VWF to a captured recombinant fragment of GPIbalpha (rfGPIbalpha, AA 1-289) (Vanhoorelbeke et al., Thromb Haemost 2000; 83: 107-13). Ristocetin 63-73 von Willebrand factor Homo sapiens 243-246 14750934-0 2003 Successful treatment of urgent bleeding in von Willebrand disease with factor VIII/VWF concentrate (Humate-P): use of the ristocetin cofactor assay (VWF:RCo) to measure potency and to guide therapy. Ristocetin 122-132 von Willebrand factor Homo sapiens 149-152 15493507-2 2004 Data that ristocetin-induced von Willebrand factor (VWF) binding to glycoprotein (Gp) Ibalpha activates proline-rich tyrosine kinase 2 (Pyk2) and extracellular-regulated kinase (ERK) has led to speculation that these events are coupled and that a MAP kinase may activate cytosolic phospholipase A2 (cPLA2)-mediated arachidonic acid (AA) release. Ristocetin 10-20 von Willebrand factor Homo sapiens 52-55 15333037-15 2004 Overall the best performance was observed for three methods measuring cleaved VWF by ristocetin cofactor, collagen binding, and immunoblotting of degraded multimers of VWF substrate, respectively. Ristocetin 85-95 von Willebrand factor Homo sapiens 78-81 15333040-1 2004 We have previously described a monoclonal antibody (mAb), 1C1E7, against von Willebrand factor (VWF), that increases ristocetin-induced platelet aggregation (RIPA) and induces a preferential binding of the high-molecular-weight multimers of VWF to platelet GPIb. Ristocetin 117-127 von Willebrand factor Homo sapiens 73-94 15333040-1 2004 We have previously described a monoclonal antibody (mAb), 1C1E7, against von Willebrand factor (VWF), that increases ristocetin-induced platelet aggregation (RIPA) and induces a preferential binding of the high-molecular-weight multimers of VWF to platelet GPIb. Ristocetin 117-127 von Willebrand factor Homo sapiens 96-99 15333040-1 2004 We have previously described a monoclonal antibody (mAb), 1C1E7, against von Willebrand factor (VWF), that increases ristocetin-induced platelet aggregation (RIPA) and induces a preferential binding of the high-molecular-weight multimers of VWF to platelet GPIb. Ristocetin 117-127 von Willebrand factor Homo sapiens 241-244 14757772-5 2004 Mutations at Glu128, Glu172, and Asp175 specifically decreased both ristocetin- and botrocetin-induced VWF binding, suggesting that these sites are important for VWF binding of platelet GPIb. Ristocetin 68-78 von Willebrand factor Homo sapiens 103-106 14757772-5 2004 Mutations at Glu128, Glu172, and Asp175 specifically decreased both ristocetin- and botrocetin-induced VWF binding, suggesting that these sites are important for VWF binding of platelet GPIb. Ristocetin 68-78 von Willebrand factor Homo sapiens 162-165 14757772-6 2004 Monoclonal antibody 6D1 inhibited ristocetin- and botrocetin-induced VWF binding, and a mutation at Glu125 specifically reduced the binding to 6D1. Ristocetin 34-44 von Willebrand factor Homo sapiens 69-72 14757772-8 2004 Mutations at His12 and Glu14 decreased the ristocetin-induced VWF binding with normal botrocetin-induced binding. Ristocetin 43-53 von Willebrand factor Homo sapiens 62-65 14754609-1 2004 BACKGROUND AND OBJECTIVES: The assay of ristocetin co-factor activity of von Willebrand factor (VWF:RCo) is used in the screening of patients with suspected von Willebrand"s disease (VWD), the most frequent inherited bleeding disorder. Ristocetin 40-50 von Willebrand factor Homo sapiens 96-99 14962219-2 2004 It has been proposed that VWF:ristocetin cofactor (VWF:RCo) activity may be useful in evaluating the response to VWD treatment in patients who require replacement therapy. Ristocetin 30-40 von Willebrand factor Homo sapiens 26-29 14962219-2 2004 It has been proposed that VWF:ristocetin cofactor (VWF:RCo) activity may be useful in evaluating the response to VWD treatment in patients who require replacement therapy. Ristocetin 30-40 von Willebrand factor Homo sapiens 51-54 15467896-0 2004 Increased shear stress- and ristocetin-induced binding of von Willebrand factor to platelets in cord compared with adult plasma. Ristocetin 28-38 von Willebrand factor Homo sapiens 58-79 15467896-5 2004 Subsequently, vWf-platelet interaction was induced by exposing the mixture to shear stress by means of a cone/plate measuring system or by incubating the mixture with ristocetin. Ristocetin 167-177 von Willebrand factor Homo sapiens 14-17 15467896-8 2004 We found that significantly higher amounts of neonatal vWf were attached to platelets in the presence of shear stress or ristocetin. Ristocetin 121-131 von Willebrand factor Homo sapiens 55-58 15467896-10 2004 Furthermore, decreasing the vWf content in cord plasma to adult level resulted in significantly suppressed vWf-platelet attachment in the presence of ristocetin, indicating that the high neonatal vWf level contributes to the efficient vWf-platelet binding in neonates. Ristocetin 150-160 von Willebrand factor Homo sapiens 28-31 15311161-1 2004 We have set up a rapid assay for measuring the activity of the von Willebrand factor ristocetin cofactor (VWF : RCo) using an automated coagulometer (ACL 9000; Instrumentation Laboratory, Lexington, Massachusetts, USA) and commercially available lyophilized platelet reagents (Dade-Behring, Marburg, Germany). Ristocetin 85-95 von Willebrand factor Homo sapiens 63-84 15311161-1 2004 We have set up a rapid assay for measuring the activity of the von Willebrand factor ristocetin cofactor (VWF : RCo) using an automated coagulometer (ACL 9000; Instrumentation Laboratory, Lexington, Massachusetts, USA) and commercially available lyophilized platelet reagents (Dade-Behring, Marburg, Germany). Ristocetin 85-95 von Willebrand factor Homo sapiens 106-109 12223999-3 2002 We developed a new, rapid, and simple method for measuring VWFcp activity based on the positive correlation between VWF multimeric size and Ristocetin cofactor activity (VWF:RCo). Ristocetin 140-150 von Willebrand factor Homo sapiens 59-62 14521604-1 2003 Tests based on three different principles are reported to measure the activity of von Willebrand factor (VWF): ristocetin cofactor (VWF:RCo), collagen binding (VWF:CB), and the so-called "activity ELISA" (VWF:MoAb). Ristocetin 111-121 von Willebrand factor Homo sapiens 82-103 14521604-1 2003 Tests based on three different principles are reported to measure the activity of von Willebrand factor (VWF): ristocetin cofactor (VWF:RCo), collagen binding (VWF:CB), and the so-called "activity ELISA" (VWF:MoAb). Ristocetin 111-121 von Willebrand factor Homo sapiens 105-108 12791664-6 2003 When the A4 peptide was delivered to intact human platelets using a carrier peptide, we observed the dose-dependent inhibition of VWF-induced platelet aggregation in response to both ristocetin and shear stress. Ristocetin 183-193 von Willebrand factor Homo sapiens 130-133 12871453-8 2003 Sixteen of 22 women with reduced ristocetin aggregation had von Willebrand ristocetin cofactor (VWF:RCo) and von Willebrand factor antigen (VWF:Ag) > 60%. Ristocetin 33-43 von Willebrand factor Homo sapiens 96-99 12871453-8 2003 Sixteen of 22 women with reduced ristocetin aggregation had von Willebrand ristocetin cofactor (VWF:RCo) and von Willebrand factor antigen (VWF:Ag) > 60%. Ristocetin 33-43 von Willebrand factor Homo sapiens 140-143 12817908-3 2003 The most widely used method for measurement of VWF activity is the ristocetin cofactor assay (VWF:RCo), which is still crucial for the laboratory diagnosis of von Willebrand"s disease (VWD). Ristocetin 67-77 von Willebrand factor Homo sapiens 47-50 12817908-3 2003 The most widely used method for measurement of VWF activity is the ristocetin cofactor assay (VWF:RCo), which is still crucial for the laboratory diagnosis of von Willebrand"s disease (VWD). Ristocetin 67-77 von Willebrand factor Homo sapiens 94-97 12817908-10 2003 CONCLUSION: The accuracy and precision of the von Willebrand activity assay may be improved if a flow cytometer is utilized for measurement of the impact of ristocetin on binding of VWF to formalin-fixed platelets instead of measuring agglutination utilizing an aggregometer. Ristocetin 157-167 von Willebrand factor Homo sapiens 182-185 12410584-2 2002 Ristocetin cofactor (RCoF) assay is used to evaluate VWF activity, but it does not assess collagen-binding activity. Ristocetin 0-10 von Willebrand factor Homo sapiens 53-56 12176890-6 2002 The expressed dimeric VWF displayed a loss of several specific functions: collagen binding, factor VIII binding, and ristocetin-induced platelet binding. Ristocetin 117-127 von Willebrand factor Homo sapiens 22-25 12932308-1 2003 Diagnosis of mild forms of type 1 and 2 von Willebrand disease (VWD) may be difficult, especially when the levels of von Willebrand factor (VWF) activities measured as ristocetin cofactor are close to normal (30-60 U/dL) because the laboratory phenotype is highly heterogeneous and confounded by factors outside the VWF gene (eg, blood group) that may influence VWF levels. Ristocetin 168-178 von Willebrand factor Homo sapiens 117-138 12932308-1 2003 Diagnosis of mild forms of type 1 and 2 von Willebrand disease (VWD) may be difficult, especially when the levels of von Willebrand factor (VWF) activities measured as ristocetin cofactor are close to normal (30-60 U/dL) because the laboratory phenotype is highly heterogeneous and confounded by factors outside the VWF gene (eg, blood group) that may influence VWF levels. Ristocetin 168-178 von Willebrand factor Homo sapiens 140-143 12923581-3 2003 The laboratory features showed a high platelet concentration and a qualitative defect of von Willebrand factor (vWF) with a low normal vWF ristocetin cofactor activity, a normal vWF antigen and a decrease of the larger vWF multimers in plasma. Ristocetin 139-149 von Willebrand factor Homo sapiens 89-110 12588351-5 2003 F1285rVWF exhibited a slight decrease of high-molecular-weight multimers and markedly reduced ristocetin- or botrocetin-induced binding of VWF to platelets in association with a decreased binding to botrocetin. Ristocetin 94-104 von Willebrand factor Homo sapiens 6-9 12588351-6 2003 The hybrid S/F1285rVWF showed a normal multimeric profile and bound to platelets in a similar way to the patients" plasma VWF, in the presence of ristocetin or botrocetin. Ristocetin 146-156 von Willebrand factor Homo sapiens 19-22 12871509-3 2003 This was accomplished using porcine VWF, which has been shown to interact with human GPIb independently of shear stress or ristocetin. Ristocetin 123-133 von Willebrand factor Homo sapiens 36-39 12871537-4 2003 Ristocetin was found to increase the rate of VWF proteolysis approximately two-fold; the differential between blood groups was retained in the presence of ristocetin. Ristocetin 0-10 von Willebrand factor Homo sapiens 45-48 12152679-1 2002 We have evaluated two automated methods for measuring ristocetin cofactor activity (VWF:RCo) on an automated coagulation analyzer (STAR, Diagnostica Stago Inc., Parsippany, NJ). Ristocetin 54-64 von Willebrand factor Homo sapiens 84-87 12223999-3 2002 We developed a new, rapid, and simple method for measuring VWFcp activity based on the positive correlation between VWF multimeric size and Ristocetin cofactor activity (VWF:RCo). Ristocetin 140-150 von Willebrand factor Homo sapiens 116-119 11772401-3 2002 In washed platelets, vWF/ristocetin and vWF/botrocetin stimulate weak tyrosine phosphorylation of the FcR gamma-chain, Syk and PLCgamma2, but not the adaptor LAT (linker for activation of T-cells), which is localized to glycolipid-enriched membrane domains. Ristocetin 25-35 von Willebrand factor Homo sapiens 21-24 11943773-2 2002 In vitro platelet glycoprotein Ib (GPIb) binding of the human von Willebrand factor (VWF) increases markedly by exogenous modulators such as ristocetin or botrocetin, and the binding does not occur in normal circulation. Ristocetin 141-151 von Willebrand factor Homo sapiens 62-83 11943773-2 2002 In vitro platelet glycoprotein Ib (GPIb) binding of the human von Willebrand factor (VWF) increases markedly by exogenous modulators such as ristocetin or botrocetin, and the binding does not occur in normal circulation. Ristocetin 141-151 von Willebrand factor Homo sapiens 85-88 12038791-7 2002 Ristocetin-induced 125I-vWF binding to L70F, however, did not differ from that to WT. Ristocetin 0-10 von Willebrand factor Homo sapiens 24-27 12008954-6 2002 Ristocetin-mediated binding of VWF transiently elevated [Ca2+]i after a lag phase. Ristocetin 0-10 von Willebrand factor Homo sapiens 31-34 12010796-6 2002 The force required to break the ristocetin- and botrocetin-induced plasma VWF-GP Ib-IX bonds occurred in integer multiples of 6.5 pN and 8.8 pN, respectively, depending on the number of bonds formed. Ristocetin 32-42 von Willebrand factor Homo sapiens 74-77 11994985-6 2002 However, ivIG pretreatment improved the VWF ristocetin cofactor (VWF:RCo) half-life from only 1.5 hr to more than 4 hr, allowing desmopressin infusions twice daily to maintain sufficient VWF:RCo levels. Ristocetin 44-54 von Willebrand factor Homo sapiens 40-43 11994985-6 2002 However, ivIG pretreatment improved the VWF ristocetin cofactor (VWF:RCo) half-life from only 1.5 hr to more than 4 hr, allowing desmopressin infusions twice daily to maintain sufficient VWF:RCo levels. Ristocetin 44-54 von Willebrand factor Homo sapiens 65-68 11994985-6 2002 However, ivIG pretreatment improved the VWF ristocetin cofactor (VWF:RCo) half-life from only 1.5 hr to more than 4 hr, allowing desmopressin infusions twice daily to maintain sufficient VWF:RCo levels. Ristocetin 44-54 von Willebrand factor Homo sapiens 65-68 11992238-0 2002 Comparative study on collagen-binding enzyme-linked immunosorbent assay and ristocetin cofactor activity assays for detection of functional activity of von Willebrand factor. Ristocetin 76-86 von Willebrand factor Homo sapiens 152-173 11992238-1 2002 For more than two decades, the ristocetin cofactor (RCo) assay, which measures the von Willebrand factor (vWF)-mediated agglutination of platelets in the presence of the antibiotic ristocetin, has been the most common method for measuring the functional activity of vWF. Ristocetin 31-41 von Willebrand factor Homo sapiens 83-104 11992238-1 2002 For more than two decades, the ristocetin cofactor (RCo) assay, which measures the von Willebrand factor (vWF)-mediated agglutination of platelets in the presence of the antibiotic ristocetin, has been the most common method for measuring the functional activity of vWF. Ristocetin 31-41 von Willebrand factor Homo sapiens 106-109 11992238-1 2002 For more than two decades, the ristocetin cofactor (RCo) assay, which measures the von Willebrand factor (vWF)-mediated agglutination of platelets in the presence of the antibiotic ristocetin, has been the most common method for measuring the functional activity of vWF. Ristocetin 31-41 von Willebrand factor Homo sapiens 266-269 11992239-8 2002 The currently used vWF:RCof test is an agglutination test in which patients" plasma is added to washed fixed control platelets in the presence of ristocetin and the extent of agglutination is measured. Ristocetin 146-156 von Willebrand factor Homo sapiens 19-22 11756169-10 2002 Similar behavior was demonstrated by VWF ristocetin cofactor activity and FVIII. Ristocetin 41-51 von Willebrand factor Homo sapiens 37-40 11948601-7 2002 Since vWf does not bind GP Ibalpha without high shear stress, the compounds botrocetin and ristocetin were used to induce binding between human vWf and the chimeras. Ristocetin 91-101 von Willebrand factor Homo sapiens 144-147 11547362-6 2001 Functional analysis has shown that r-vWF promotes ristocetin cofactor-mediated platelet aggregation, collagen interaction and FVIII binding, and platelet-collagen adhesion under shear stress. Ristocetin 50-60 von Willebrand factor Homo sapiens 37-40 11535515-7 2001 vWf binding was increased at all concentrations of ristocetin examined, and adhesion on a vWf matrix was enhanced in terms of cell tethering, slower rolling velocity, and decreased detachment with increasing shear rate. Ristocetin 51-61 von Willebrand factor Homo sapiens 0-3 17903829-3 2001 The vWF was measured by the ristocetin cofactor assay. Ristocetin 28-38 von Willebrand factor Homo sapiens 4-7 11468163-4 2001 These antibodies, however, had little or no effect (approximately 40% inhibition) on the binding of vWF induced by either botrocetin or ristocetin. Ristocetin 136-146 von Willebrand factor Homo sapiens 100-103 12214161-3 2002 On the 4th day after the infusion, VWF antigen and VWF ristocetin cofactor increased to 40 and 78% of the control, respectively, and dental extractions were performed successfully. Ristocetin 55-65 von Willebrand factor Homo sapiens 51-54 11981108-3 2001 When com-bined, 1C1E7 and 75H4B12 promoted vWf binding to isolated GPIb under static conditions, even in the absence of ristocetin or botrocetin, and induced platelet aggregation synergistically in the presence of zero to subthreshold ristocetin concentrations. Ristocetin 235-245 von Willebrand factor Homo sapiens 43-46 11341505-4 2001 Secondly we observed a synergistic activating effect of two anti-von Willebrand factor (vWF) MoAbs IC1E7 and B724, both known to enhance vWF binding to GPIbalpha in the presence of shear or ristocetin. Ristocetin 190-200 von Willebrand factor Homo sapiens 60-86 11292197-5 2001 We found a significant increase in plasma factor VIII (FVIII), vWF:antigen (Ag), and vWF:ristocetin cofactor (Rco) levels, associated with a mean decrease in platelet vWF:Ag. Ristocetin 89-99 von Willebrand factor Homo sapiens 85-88 11686107-6 2001 The laboratory findings of AVWS associated with systemic lupus erythematosus or IgG benign monoclonal gammopathy are characterized by a prolonged bleeding time and activated partial thromboplastin time, decreased or absent ristocetin-induced platelet activity, low to very low levels of factor VIII coagulant activity (mean 15%), VWF: Ag (mean 10.7%) and VWF: RCo (mean 6.2%), and a type II multimeric pattern of VWF. Ristocetin 223-233 von Willebrand factor Homo sapiens 330-333 11686107-6 2001 The laboratory findings of AVWS associated with systemic lupus erythematosus or IgG benign monoclonal gammopathy are characterized by a prolonged bleeding time and activated partial thromboplastin time, decreased or absent ristocetin-induced platelet activity, low to very low levels of factor VIII coagulant activity (mean 15%), VWF: Ag (mean 10.7%) and VWF: RCo (mean 6.2%), and a type II multimeric pattern of VWF. Ristocetin 223-233 von Willebrand factor Homo sapiens 355-358 11686107-6 2001 The laboratory findings of AVWS associated with systemic lupus erythematosus or IgG benign monoclonal gammopathy are characterized by a prolonged bleeding time and activated partial thromboplastin time, decreased or absent ristocetin-induced platelet activity, low to very low levels of factor VIII coagulant activity (mean 15%), VWF: Ag (mean 10.7%) and VWF: RCo (mean 6.2%), and a type II multimeric pattern of VWF. Ristocetin 223-233 von Willebrand factor Homo sapiens 355-358 11278380-3 2001 Deletion of the filamin binding site in GPIb(alpha) markedly enhances ristocetin- (or botrocetin)-induced vWF binding and allows GPIb-IX-expressing cells to adhere to immobilized vWF under both static and flow conditions. Ristocetin 70-80 von Willebrand factor Homo sapiens 106-109 11279169-9 2001 Cells expressing the Glu mutant, on the other hand, were normal with respect to ristocetin-induced vWF binding and adhesion to immobilized vWF but were markedly defective in botrocetin-induced vWF binding. Ristocetin 80-90 von Willebrand factor Homo sapiens 99-102 11279169-10 2001 These results indicate that GP I(b)alpha tyrosine sulfation influences the interaction of this polypeptide with vWF primarily by contributing negative charges under physiological conditions and when the interaction is induced by ristocetin but contributes a specific structure to the botrocetin-induced interaction. Ristocetin 229-239 von Willebrand factor Homo sapiens 112-115 11292197-5 2001 We found a significant increase in plasma factor VIII (FVIII), vWF:antigen (Ag), and vWF:ristocetin cofactor (Rco) levels, associated with a mean decrease in platelet vWF:Ag. Ristocetin 89-99 von Willebrand factor Homo sapiens 85-88 11341505-4 2001 Secondly we observed a synergistic activating effect of two anti-von Willebrand factor (vWF) MoAbs IC1E7 and B724, both known to enhance vWF binding to GPIbalpha in the presence of shear or ristocetin. Ristocetin 190-200 von Willebrand factor Homo sapiens 88-91 11150026-1 2001 We describe a von Willebrand disease (VWD) variant characterized by low plasma and platelet von Willebrand factor (VWF), impaired ristocetin-induced VWF binding to platelet glycoprotein Ib (GPIb), and abnormal VWF multimer pattern not associated with the absence of large forms. Ristocetin 130-140 von Willebrand factor Homo sapiens 149-152 11190800-6 2001 Maximal vWF binding induced by botrocetin was only 10% to 15% of that observed with ristocetin. Ristocetin 84-94 von Willebrand factor Homo sapiens 8-11 11159522-1 2001 The study identified 10 patients from 6 families with prolonged bleeding time, decreased von Willebrand factor (vWF) ristocetin cofactor activity (RCoF) to vWF:Ag (antigen) ratio, and reduced ristocetin-induced platelet agglutination as well as ristocetin- or botrocetin-induced binding of plasma vWF to platelet glycoprotein Ib (GpIb). Ristocetin 117-127 von Willebrand factor Homo sapiens 112-115 11181425-5 2001 In vitro, agkistin concentration-dependently inhibited ristocetin-induced human platelet agglutination and aggregation in the presence of vWF. Ristocetin 55-65 von Willebrand factor Homo sapiens 138-141 11240613-7 2001 Preliminary results of recent studies support the hypothesis that treatment with factor VIII/vWF concentrates based upon the content of vWF activity as reflected in the ristocetin cofactor assay is practicable, safe and efficacious. Ristocetin 169-179 von Willebrand factor Homo sapiens 93-96 11240613-7 2001 Preliminary results of recent studies support the hypothesis that treatment with factor VIII/vWF concentrates based upon the content of vWF activity as reflected in the ristocetin cofactor assay is practicable, safe and efficacious. Ristocetin 169-179 von Willebrand factor Homo sapiens 136-139 11150026-1 2001 We describe a von Willebrand disease (VWD) variant characterized by low plasma and platelet von Willebrand factor (VWF), impaired ristocetin-induced VWF binding to platelet glycoprotein Ib (GPIb), and abnormal VWF multimer pattern not associated with the absence of large forms. Ristocetin 130-140 von Willebrand factor Homo sapiens 149-152 11150026-3 2001 In addition to the decreased factor VIII (FVIII) and VWF levels, ristocetin-induced platelet aggregation (RIPA) was almost absent, and VWF ristocetin cofactor activity (VWF:RCo) was significantly more decreased than VWF antigen. Ristocetin 139-149 von Willebrand factor Homo sapiens 135-138 11150026-3 2001 In addition to the decreased factor VIII (FVIII) and VWF levels, ristocetin-induced platelet aggregation (RIPA) was almost absent, and VWF ristocetin cofactor activity (VWF:RCo) was significantly more decreased than VWF antigen. Ristocetin 139-149 von Willebrand factor Homo sapiens 135-138 11150026-3 2001 In addition to the decreased factor VIII (FVIII) and VWF levels, ristocetin-induced platelet aggregation (RIPA) was almost absent, and VWF ristocetin cofactor activity (VWF:RCo) was significantly more decreased than VWF antigen. Ristocetin 139-149 von Willebrand factor Homo sapiens 135-138 10713323-9 2000 Linear regression analysis showed good correlation of results of sulfatide-binding assay for von Willebrand factor with results of the von Willebrand factor antigen, Ristocetin cofactor assay for von Willebrand factor, and collagen-binding assay for von Willebrand factor. Ristocetin 166-176 von Willebrand factor Homo sapiens 93-114 10959687-5 2000 This elevation of vWf antigen represented functionally normal vWf as evaluated by plasma FVIII, ristocetin cofactor assay and vWf multimer analyses. Ristocetin 96-106 von Willebrand factor Homo sapiens 18-21 10959688-4 2000 The patients who have a discrepancy between vWF antigen level and vWF ristocetin cofactor activity exhibited decreased ristocetin-induced binding but only a slight decrease in the percentage of high molecular weight (HMW) multimers in plasma. Ristocetin 70-80 von Willebrand factor Homo sapiens 66-69 10959688-4 2000 The patients who have a discrepancy between vWF antigen level and vWF ristocetin cofactor activity exhibited decreased ristocetin-induced binding but only a slight decrease in the percentage of high molecular weight (HMW) multimers in plasma. Ristocetin 119-129 von Willebrand factor Homo sapiens 44-47 10959688-4 2000 The patients who have a discrepancy between vWF antigen level and vWF ristocetin cofactor activity exhibited decreased ristocetin-induced binding but only a slight decrease in the percentage of high molecular weight (HMW) multimers in plasma. Ristocetin 119-129 von Willebrand factor Homo sapiens 66-69 11710113-7 2000 The addition of ristocetin to the rGPIb alpha-AMS in the presence of vWf caused specific aggregation. Ristocetin 16-26 von Willebrand factor Homo sapiens 69-72 10845912-2 2000 We report on 9 fully multimerized recombinant vWFs (rvWFs) expressing type 2M or type 2B von Willebrand disease (vWD) mutations, characterized respectively by a decreased or increased binding of vWF to GPIb in the presence of ristocetin. Ristocetin 226-236 von Willebrand factor Homo sapiens 46-49 11014964-6 2000 In contrast, MoAb 28E6 did abolish both the ristocetin- and botrocetin-induced GPIb-vWF binding, whereas it did not block the shear-induced interaction. Ristocetin 44-54 von Willebrand factor Homo sapiens 84-87 11014964-7 2000 Thus, we identify here two anti-GPIb MoAbs 27A10 and 28E6 that either preferentially inhibit the shear-induced or the ristocetin/botrocetin-induced platelet-vWF interaction. Ristocetin 118-128 von Willebrand factor Homo sapiens 157-160 10753907-7 2000 Ristocetin and botrocetin actions on VWF were dissociated readily by mutagenesis. Ristocetin 0-10 von Willebrand factor Homo sapiens 37-40 10959711-9 2000 Ristocetin cofactor activity (vWF:RCo) or collagen binding activity (vWF:CBA) were usually low in AvWS (median values 20 U/dL, range 3-150), while factor VIII coagulant activity was sometimes normal (median 25 U/dL, range 3-191). Ristocetin 0-10 von Willebrand factor Homo sapiens 30-33 10648402-3 2000 We have used mammalian cell expression of canine-human chimeras of GP Ibalpha, corresponding to precise structural boundaries, to demonstrate the first specific requirement for individual leucine-rich repeats for binding of vWf either induced by a modulator, ristocetin, or under hydrodynamic flow. Ristocetin 259-269 von Willebrand factor Homo sapiens 224-227 10494765-2 1999 Diagnosis was based on a positive family history and low von Willebrand factor (VWF) ristocetin cofactor activity. Ristocetin 85-95 von Willebrand factor Homo sapiens 80-83 10739395-6 2000 Addition of protamine sulphate to platelet-rich plasma (PRP), reduced significantly the GPIb-vWF activity as assessed by ristocetin-induced platelet agglutination. Ristocetin 121-131 von Willebrand factor Homo sapiens 93-96 10669163-1 2000 The ristocetin induced binding of vWF to GPIb, which is routinely tested in a platelet agglutination assay, can be reproducibly studied in an ELISA where plasma vWF binds to a captured rGPIb alpha-fragment (His1-Val289) in the presence of ristocetin. Ristocetin 4-14 von Willebrand factor Homo sapiens 34-37 10669163-1 2000 The ristocetin induced binding of vWF to GPIb, which is routinely tested in a platelet agglutination assay, can be reproducibly studied in an ELISA where plasma vWF binds to a captured rGPIb alpha-fragment (His1-Val289) in the presence of ristocetin. Ristocetin 4-14 von Willebrand factor Homo sapiens 161-164 10669163-1 2000 The ristocetin induced binding of vWF to GPIb, which is routinely tested in a platelet agglutination assay, can be reproducibly studied in an ELISA where plasma vWF binds to a captured rGPIb alpha-fragment (His1-Val289) in the presence of ristocetin. Ristocetin 239-249 von Willebrand factor Homo sapiens 34-37 10669163-1 2000 The ristocetin induced binding of vWF to GPIb, which is routinely tested in a platelet agglutination assay, can be reproducibly studied in an ELISA where plasma vWF binds to a captured rGPIb alpha-fragment (His1-Val289) in the presence of ristocetin. Ristocetin 239-249 von Willebrand factor Homo sapiens 161-164 10669163-2 2000 This binding is specific since the vWF-GPIb interaction could (i) be blocked by inhibitory anti-GPIb or anti-(vWF A1 domain) monoclonal antibodies (mAbs) and (ii) be enhanced by an anti-vWF mAb that also facilitates ristocetin induced platelet agglutination. Ristocetin 216-226 von Willebrand factor Homo sapiens 35-38 10739386-9 2000 Patient 1 antibody also blocked vWF binding to platelet GPIb when induced by ristocetin. Ristocetin 77-87 von Willebrand factor Homo sapiens 32-35 10739386-11 2000 Our data thus suggest that this inhibitor does not recognize the GPIb-binding site on vWF but the sites of vWF involved in its interaction with ristocetin. Ristocetin 144-154 von Willebrand factor Homo sapiens 107-110 10590063-4 1999 Ristocetin-induced CHO-GPIbalphabeta/IX cell aggregation was completely inhibited by the recombinant VCL fragment of vWF that contains the A1 domain. Ristocetin 0-10 von Willebrand factor Homo sapiens 117-120 10590063-6 1999 Using monoclonal antibodies blocking vWF interaction with GPIb/V/IX or mocarhagin, a venom metalloproteinase that removes the amino-terminal fragment of GPIbalpha extending from aa 1 to 282, we demonstrated that both ristocetin- and heparin-induced aggregations involved an interaction between the A1 domain of vWF and the GPIbalpha subunit of the GPIb/V/IX complex. Ristocetin 217-227 von Willebrand factor Homo sapiens 37-40 10497852-1 1999 Type 2B von Willebrand disease (vWD) is a von Willebrand factor (vWF) subtype with increased binding affinity for platelet glycoprotein (GP) Ib and is characterized by increased ristocetin-induced platelet agglutination at low concentrations of ristocetin. Ristocetin 178-188 von Willebrand factor Homo sapiens 42-63 10497852-1 1999 Type 2B von Willebrand disease (vWD) is a von Willebrand factor (vWF) subtype with increased binding affinity for platelet glycoprotein (GP) Ib and is characterized by increased ristocetin-induced platelet agglutination at low concentrations of ristocetin. Ristocetin 178-188 von Willebrand factor Homo sapiens 65-68 10497852-1 1999 Type 2B von Willebrand disease (vWD) is a von Willebrand factor (vWF) subtype with increased binding affinity for platelet glycoprotein (GP) Ib and is characterized by increased ristocetin-induced platelet agglutination at low concentrations of ristocetin. Ristocetin 245-255 von Willebrand factor Homo sapiens 65-68 10494765-10 1999 The results of this study illustrate that a personal and family bleeding history and persistently low VWF ristocetin cofactor activity, fitting the usual criteria for type 1 VWD, may not cosegregate with genetic markers at the VWF gene locus. Ristocetin 106-116 von Willebrand factor Homo sapiens 102-105 10381514-6 1999 Ristocetin-mediated binding of vWF induced a transient platelet [Ca2+]i increase at 37 degrees C, but no response at lower temperatures (20 degrees C to 25 degrees C). Ristocetin 0-10 von Willebrand factor Homo sapiens 31-34 10027712-5 1999 Ristocetin-induced agglutinations of both the thrombin- and TRAP-stimulated platelets were lowered during the decreased surface expressions of GPIbalpha, GPIX and GPV/GPVf2 and then normalized when these GPs were again redistributed onto the surface, indicating that the redistributed GPIb/IX/Vf2 complex on the surface can act as a VWF receptor as efficiently as an intact GPIb/IX/V. Ristocetin 0-10 von Willebrand factor Homo sapiens 333-336 10339461-9 1999 Also, in patients with vWD type 1 and borderline to normal ristocetin-cofactor (vWF:RCo) activity values, collagen receptor density correlates inversely with closure time in a high shear stress system (platelet function analyzer [PFA-100]). Ristocetin 59-69 von Willebrand factor Homo sapiens 80-83 10233433-5 1999 In all cases a mixture of patient"s plasma with normal plasma resulted in inhibition of ristocetin-induced binding of VWF to normal platelets. Ristocetin 88-98 von Willebrand factor Homo sapiens 118-121 9731234-4 1998 Interestingly, binding of von Willebrand Factor (vWF) to purified GPIb in the presence of ristocetin and botrocetin in a standardized microtiter plate assay was not altered by partial or even by total deglycosylation. Ristocetin 90-100 von Willebrand factor Homo sapiens 26-47 9759623-5 1998 The vWF-GPIb interaction was exclusively able to support ristocetin-mediated shear aggregation of metabolically active platelets, with very few vWF monomer equivalents bound per platelet (representing < or = 10 molecules of 10 million Da) required to yield high capture efficiencies (alphaG = 0.38+/-.02; n = 11), suggesting rapid and stable bond formations between vWF and GPIb. Ristocetin 57-67 von Willebrand factor Homo sapiens 4-7 9731234-4 1998 Interestingly, binding of von Willebrand Factor (vWF) to purified GPIb in the presence of ristocetin and botrocetin in a standardized microtiter plate assay was not altered by partial or even by total deglycosylation. Ristocetin 90-100 von Willebrand factor Homo sapiens 49-52 9588391-5 1998 Surprisingly, ristocetin, which "chemically activates" GPIb/vWF to mediate spontaneous binding of the ligand to its receptor, at low concentrations yielding <2000 platelet-bound vWF monomers, gave efficient aggregation even at 1000 sec(-1) (CE = 0.34 +/- 0.02, n = 11) with only GPIb required. Ristocetin 14-24 von Willebrand factor Homo sapiens 60-63 9572997-7 1998 All inhibitors blocked ristocetin-mediated vWF binding to platelets. Ristocetin 23-33 von Willebrand factor Homo sapiens 43-46 9573016-13 1998 Our results suggested that on binding to a botrocetin-binding site on vWF, MoAb 724 mimics the effect of botrocetin by inducing an active conformation of vWF that is more sensitive to shear stress or to low ristocetin concentration. Ristocetin 207-217 von Willebrand factor Homo sapiens 70-73 9573016-13 1998 Our results suggested that on binding to a botrocetin-binding site on vWF, MoAb 724 mimics the effect of botrocetin by inducing an active conformation of vWF that is more sensitive to shear stress or to low ristocetin concentration. Ristocetin 207-217 von Willebrand factor Homo sapiens 154-157 9588391-5 1998 Surprisingly, ristocetin, which "chemically activates" GPIb/vWF to mediate spontaneous binding of the ligand to its receptor, at low concentrations yielding <2000 platelet-bound vWF monomers, gave efficient aggregation even at 1000 sec(-1) (CE = 0.34 +/- 0.02, n = 11) with only GPIb required. Ristocetin 14-24 von Willebrand factor Homo sapiens 181-184 9473222-3 1998 Whereas ristocetin-induced binding of plasma vWF from affected members of both families to fixed platelets was reduced, botrocetin-induced platelet binding was normal. Ristocetin 8-18 von Willebrand factor Homo sapiens 45-48 9531591-7 1998 The low-dose ristocetin aggregation in patient platelet-rich plasma (PRP) was completely blocked by neutralizing antiglycoprotein Ib (GPIb) and anti-vWF antibodies. Ristocetin 13-23 von Willebrand factor Homo sapiens 149-152 9531591-8 1998 The monoclonal anti-Fc gamma RII receptor antibody IV.3 inhibited partly, which suggests that PRP aggregation by low-dose ristocetin was elicited by vWF-immunoglobulin (Ig) complexes. Ristocetin 122-132 von Willebrand factor Homo sapiens 149-152 9531591-9 1998 Upon addition to washed human platelets, with vWF (10 micrograms/mL), purified patient Igs dose-dependently enhanced ristocetin (0.15 mg/mL)-induced aggregation between 0 and 500 micrograms/mL, an effect that disappeared again above 1 mg/mL. Ristocetin 117-127 von Willebrand factor Homo sapiens 46-49 9490688-2 1998 The A1, A2, and A3 domains in vWF mediate binding to glycoprotein Ib, ristocetin, botrocetin, collagen, sulphatides, and heparin and provide a protease cleavage site. Ristocetin 70-80 von Willebrand factor Homo sapiens 30-33 9619734-6 1998 Monoclonal antibody directed to the region within the A1 domain of vWF which interacts with the glycoprotein Ib completely inhibited the vWF ristocetin cofactor (vWF:RistCof), while vWF:CBA was not affected. Ristocetin 141-151 von Willebrand factor Homo sapiens 67-70 9619734-6 1998 Monoclonal antibody directed to the region within the A1 domain of vWF which interacts with the glycoprotein Ib completely inhibited the vWF ristocetin cofactor (vWF:RistCof), while vWF:CBA was not affected. Ristocetin 141-151 von Willebrand factor Homo sapiens 137-140 9619734-6 1998 Monoclonal antibody directed to the region within the A1 domain of vWF which interacts with the glycoprotein Ib completely inhibited the vWF ristocetin cofactor (vWF:RistCof), while vWF:CBA was not affected. Ristocetin 141-151 von Willebrand factor Homo sapiens 137-140 9619734-6 1998 Monoclonal antibody directed to the region within the A1 domain of vWF which interacts with the glycoprotein Ib completely inhibited the vWF ristocetin cofactor (vWF:RistCof), while vWF:CBA was not affected. Ristocetin 141-151 von Willebrand factor Homo sapiens 137-140 9473222-7 1998 Expression of recombinant vWF containing either F606I or I662F mutations resulted in mutant recombinant vWF with decreased ristocetin-induced platelet binding, but normal multimer structure, botrocetin-induced platelet binding, collagen binding, and binding to the conformation-sensitive monoclonal antibody, AvW-3. Ristocetin 123-133 von Willebrand factor Homo sapiens 26-29 9473222-7 1998 Expression of recombinant vWF containing either F606I or I662F mutations resulted in mutant recombinant vWF with decreased ristocetin-induced platelet binding, but normal multimer structure, botrocetin-induced platelet binding, collagen binding, and binding to the conformation-sensitive monoclonal antibody, AvW-3. Ristocetin 123-133 von Willebrand factor Homo sapiens 104-107 9452127-0 1998 Ristocetin-mediated interaction of human von Willebrand factor with platelet glycoprotein lb evokes a transient calcium signal: observations with Fura-PE3. Ristocetin 0-10 von Willebrand factor Homo sapiens 41-62 9607124-2 1998 Coagulation studies showed a von Willebrand factor (vWF) defect (Duke bleeding time > 20 min; ristocetin cofactor activity [vWF:RC] < 6%; significant reduction of large multimers of vWF. Ristocetin 97-107 von Willebrand factor Homo sapiens 29-50 9607124-2 1998 Coagulation studies showed a von Willebrand factor (vWF) defect (Duke bleeding time > 20 min; ristocetin cofactor activity [vWF:RC] < 6%; significant reduction of large multimers of vWF. Ristocetin 97-107 von Willebrand factor Homo sapiens 52-55 9607124-5 1998 The inhibitor blocked the interaction of vWF with glycoprotein Ib in the presence of ristocetin, as did the pepsin-digested fragment of the inhibitor [F(ab)2"], but neither blocked botrocetin-mediated interaction of vWF with glycoprotein Ib. Ristocetin 85-95 von Willebrand factor Homo sapiens 41-44 9452127-3 1998 The present study examined the platelet (Ca2+)i signal that arises when ristocetin mediates vWf-GpIb binding. Ristocetin 72-82 von Willebrand factor Homo sapiens 92-95 9452127-10 1998 Ristocetin-mediated vWf-GpIb binding induced a transient increase in platelet (Ca2+)i. Ristocetin 0-10 von Willebrand factor Homo sapiens 20-23 9298543-2 1997 A murine anti-human vWF monoclonal antibody, AJvW-2, was developed that inhibited the interaction between platelet glycoprotein Ib (GPIb) and von Willebrand factor (vWF) during the ristocetin- (IC50 = 0.7 +/- 0.1 microgram ml-1) and botrocetin- (IC50 = 1.8 +/- 0.3 microgram ml-1) induced aggregation of human platelets. Ristocetin 181-191 von Willebrand factor Homo sapiens 20-23 9459348-3 1998 The first antagonist was the anti-human vWF monoclonal antibody AJvW-2, which inhibits the botrocetin and ristocetin induced aggregation of human blood platelets. Ristocetin 106-116 von Willebrand factor Homo sapiens 40-43 9459349-5 1998 Both the binding of mutated rvWFs to platelets and platelet aggregation induced by type 2B rvWFs are inhibited by monoclonal anti-GPIb and anti-vWF antibodies, inhibitors of vWF binding to platelets in the presence of ristocetin, as well as by aurin tricarboxylic acid. Ristocetin 218-228 von Willebrand factor Homo sapiens 29-32 9459349-5 1998 Both the binding of mutated rvWFs to platelets and platelet aggregation induced by type 2B rvWFs are inhibited by monoclonal anti-GPIb and anti-vWF antibodies, inhibitors of vWF binding to platelets in the presence of ristocetin, as well as by aurin tricarboxylic acid. Ristocetin 218-228 von Willebrand factor Homo sapiens 92-95 9308766-1 1997 Type 2B von Willebrand disease (vWD) is typically characterized by enhanced ristocetin-induced platelet aggregation (RIPA) caused by increased von Willebrand factor (vWF) affinity for platelets. Ristocetin 76-86 von Willebrand factor Homo sapiens 143-164 9308766-1 1997 Type 2B von Willebrand disease (vWD) is typically characterized by enhanced ristocetin-induced platelet aggregation (RIPA) caused by increased von Willebrand factor (vWF) affinity for platelets. Ristocetin 76-86 von Willebrand factor Homo sapiens 166-169 9298543-2 1997 A murine anti-human vWF monoclonal antibody, AJvW-2, was developed that inhibited the interaction between platelet glycoprotein Ib (GPIb) and von Willebrand factor (vWF) during the ristocetin- (IC50 = 0.7 +/- 0.1 microgram ml-1) and botrocetin- (IC50 = 1.8 +/- 0.3 microgram ml-1) induced aggregation of human platelets. Ristocetin 181-191 von Willebrand factor Homo sapiens 142-163 9298543-2 1997 A murine anti-human vWF monoclonal antibody, AJvW-2, was developed that inhibited the interaction between platelet glycoprotein Ib (GPIb) and von Willebrand factor (vWF) during the ristocetin- (IC50 = 0.7 +/- 0.1 microgram ml-1) and botrocetin- (IC50 = 1.8 +/- 0.3 microgram ml-1) induced aggregation of human platelets. Ristocetin 181-191 von Willebrand factor Homo sapiens 165-168 9268197-0 1997 Plasma derived von Willebrand factor preparations: collagen binding and ristocetin cofactor activities. Ristocetin 72-82 von Willebrand factor Homo sapiens 15-36 9226170-1 1997 Platelet-type von Willebrand disease (vWD) is a congenital bleeding disorder characterized by heightened ristocetin-induced platelet aggregation caused by abnormally high affinity between the platelet membrane glycoprotein (GP) Ib/IX complex and von Willebrand factor (vWF). Ristocetin 105-115 von Willebrand factor Homo sapiens 246-267 9226170-1 1997 Platelet-type von Willebrand disease (vWD) is a congenital bleeding disorder characterized by heightened ristocetin-induced platelet aggregation caused by abnormally high affinity between the platelet membrane glycoprotein (GP) Ib/IX complex and von Willebrand factor (vWF). Ristocetin 105-115 von Willebrand factor Homo sapiens 269-272 9226170-5 1997 The addition of low concentrations of ristocetin (0.2 mg/mL) induced specific 125I-vWF binding to immobilized M239V, but not to WT GPIb alpha. Ristocetin 38-48 von Willebrand factor Homo sapiens 83-86 9226170-6 1997 At high concentrations of ristocetin (1.2 mg/mL), both WT GPIb alpha and M239V specifically bound to 125I-vWF. Ristocetin 26-36 von Willebrand factor Homo sapiens 106-109 9268197-9 1997 Assignment of potency to vWF containing preparations utilizing the collagen binding activity may be more precise and as accurate as with the traditional ristocetin cofactor assay. Ristocetin 153-163 von Willebrand factor Homo sapiens 25-28 9198217-1 1997 During the past 10 years the quality of plasma derived virus inactivated products containing von Willebrand factor (vWF) has improved and the ratios of ristocetin cofactor activity (vWF:RCo) to von Willebrand factor antigen (vWF:Ag) have increased. Ristocetin 152-162 von Willebrand factor Homo sapiens 182-185 9219327-4 1997 In vitro, soluble vWF is activated to bind to platelets by nonphysiological modulators, such as the bacterial glycopeptide, ristocetin, or the snake venom protein, botrocetin, or by removal of negatively-charged sialic acid residues. Ristocetin 124-134 von Willebrand factor Homo sapiens 18-21 9219327-8 1997 Purified soluble histone also bound vWF since, like ristocetin, it induced vWF flocculation. Ristocetin 52-62 von Willebrand factor Homo sapiens 36-39 9219327-8 1997 Purified soluble histone also bound vWF since, like ristocetin, it induced vWF flocculation. Ristocetin 52-62 von Willebrand factor Homo sapiens 75-78 9219327-11 1997 This implies that specific interactions of the vWF A1 domain with either ristocetin or botrocetin are required for GP Ib-IX-V recognition to occur. Ristocetin 73-83 von Willebrand factor Homo sapiens 47-50 9198217-1 1997 During the past 10 years the quality of plasma derived virus inactivated products containing von Willebrand factor (vWF) has improved and the ratios of ristocetin cofactor activity (vWF:RCo) to von Willebrand factor antigen (vWF:Ag) have increased. Ristocetin 152-162 von Willebrand factor Homo sapiens 182-185 9031470-7 1997 The functional analysis of vWF showed a markedly decreased affinity of mutated plasma vWF for platelet GPIb in the presence of ristocetin. Ristocetin 127-137 von Willebrand factor Homo sapiens 27-30 9134656-4 1997 The inhibitor inhibited the interaction of vWF in the presence of ristocetin and that of asialo-vWF with GPIb while it partially blocked botrocetin-mediated interaction of vWF to GPIb. Ristocetin 66-76 von Willebrand factor Homo sapiens 43-46 9392827-0 1997 Synthetic peptide from the V3 loop consensus motif with a potent anti-HIV activity inhibits ristocetin-mediated vWF-GPIb interaction. Ristocetin 92-102 von Willebrand factor Homo sapiens 112-115 9392827-4 1997 These peptides interact with ristocetin-loaded platelet membrane glycoprotein (GP) Ib and act as inhibitors of von Willebrand factor (vWF)-GPIb interaction by preventing the subsequent formation of ristocetin dimer bridges. Ristocetin 198-208 von Willebrand factor Homo sapiens 111-132 9392827-4 1997 These peptides interact with ristocetin-loaded platelet membrane glycoprotein (GP) Ib and act as inhibitors of von Willebrand factor (vWF)-GPIb interaction by preventing the subsequent formation of ristocetin dimer bridges. Ristocetin 198-208 von Willebrand factor Homo sapiens 134-137 9490916-5 1997 Analysis of the mechanism according to which ristocetin induces vWF binding to GPIb revealed that 2 dimers of ristocetin simultaneously bind to vWF and GPIb, thus forming a quaternary complex in which repulsive negative charges are neutralized by the positively charged ristocetin. Ristocetin 45-55 von Willebrand factor Homo sapiens 64-67 9490916-5 1997 Analysis of the mechanism according to which ristocetin induces vWF binding to GPIb revealed that 2 dimers of ristocetin simultaneously bind to vWF and GPIb, thus forming a quaternary complex in which repulsive negative charges are neutralized by the positively charged ristocetin. Ristocetin 45-55 von Willebrand factor Homo sapiens 144-147 9490916-5 1997 Analysis of the mechanism according to which ristocetin induces vWF binding to GPIb revealed that 2 dimers of ristocetin simultaneously bind to vWF and GPIb, thus forming a quaternary complex in which repulsive negative charges are neutralized by the positively charged ristocetin. Ristocetin 110-120 von Willebrand factor Homo sapiens 64-67 9490916-5 1997 Analysis of the mechanism according to which ristocetin induces vWF binding to GPIb revealed that 2 dimers of ristocetin simultaneously bind to vWF and GPIb, thus forming a quaternary complex in which repulsive negative charges are neutralized by the positively charged ristocetin. Ristocetin 110-120 von Willebrand factor Homo sapiens 144-147 9490916-5 1997 Analysis of the mechanism according to which ristocetin induces vWF binding to GPIb revealed that 2 dimers of ristocetin simultaneously bind to vWF and GPIb, thus forming a quaternary complex in which repulsive negative charges are neutralized by the positively charged ristocetin. Ristocetin 110-120 von Willebrand factor Homo sapiens 64-67 9490916-5 1997 Analysis of the mechanism according to which ristocetin induces vWF binding to GPIb revealed that 2 dimers of ristocetin simultaneously bind to vWF and GPIb, thus forming a quaternary complex in which repulsive negative charges are neutralized by the positively charged ristocetin. Ristocetin 110-120 von Willebrand factor Homo sapiens 144-147 9031470-7 1997 The functional analysis of vWF showed a markedly decreased affinity of mutated plasma vWF for platelet GPIb in the presence of ristocetin. Ristocetin 127-137 von Willebrand factor Homo sapiens 86-89 8873615-6 1996 In contrast, only mutants vWF-R524A and vWF-K549A showed significant binding to platelets in the presence of ristocetin. Ristocetin 109-119 von Willebrand factor Homo sapiens 26-29 8873615-6 1996 In contrast, only mutants vWF-R524A and vWF-K549A showed significant binding to platelets in the presence of ristocetin. Ristocetin 109-119 von Willebrand factor Homo sapiens 40-43 8873615-7 1996 Mutant vWF-K549A showed increased platelet-binding at suboptimal concentrations of both botrocetin and ristocetin. Ristocetin 103-113 von Willebrand factor Homo sapiens 7-10 8873615-9 1996 However, the charged amino acids at positions 534, 552, 569-573, and 642-645 do play an important role in the ristocetin-induced binding of vWF to platelets. Ristocetin 110-120 von Willebrand factor Homo sapiens 140-143 8839848-4 1996 The secreted mutant vWF showed a normal multimeric profile but did not bind to platelets in the presence of optimal concentrations of either ristocetin or botrocetin. Ristocetin 141-151 von Willebrand factor Homo sapiens 20-23 8826903-3 1996 Each patient was infused with one dose of approximately 50 or 100 iu ristocetin cofactor activity (VWF:RiCoF) per kg body weight. Ristocetin 69-79 von Willebrand factor Homo sapiens 99-102 8645320-7 1996 Human vWF in the presence of ristocetin supported agglutination of transgenic mouse platelets, but not of control mouse platelets. Ristocetin 29-39 von Willebrand factor Homo sapiens 6-9 8701941-0 1996 Isolated recombinant domain of von Willebrand factor displaying increased sensitivity to ristocetin. Ristocetin 89-99 von Willebrand factor Homo sapiens 31-52 8701941-3 1996 In vitro, the soluble interaction of normal von Willebrand factor with platelets can be initiated with exogenous modulators, the most common being the antibiotic ristocetin. Ristocetin 162-172 von Willebrand factor Homo sapiens 44-65 8701941-6 1996 In this study we demonstrate that a recombinant plasmid capable of expressing the isolated GP Ib-IX binding domain of von Willebrand factor, and containing the Arg543-->Trp amino-acid substitution, secretes a dimeric molecule that supports platelet agglutination using subnormal levels of ristocetin. Ristocetin 292-302 von Willebrand factor Homo sapiens 118-139 8660497-0 1996 Inhibition assay for the binding of biotinylated von Willebrand factor to platelet-bound microtiter wells in the presence of ristocetin or botrocetin. Ristocetin 125-135 von Willebrand factor Homo sapiens 49-70 8660497-3 1996 In the presence of an antibiotic ristocetin (1 mg/ml, final) or the snake venom botrocetin (2 micrograms/ml, final), biotinylated vWF bound to the affixed platelets with half-maximal binding occurring at a vWF concentration of approximately 2 micrograms/ml. Ristocetin 33-43 von Willebrand factor Homo sapiens 130-133 8572428-3 1995 Direct shear-induced binding to washed platelets (300-360 x 10(3)/microliters) of radiolabeled vWF was maximum at 60-120 dynes/cm2 evaluated at 30 sec and was in extent about one-quarter of the binding stimulated by ristocetin after 3 min of incubation. Ristocetin 216-226 von Willebrand factor Homo sapiens 95-98 8548428-12 1996 Binding studies showed a nonsaturable ristocetin binding of VCL to platelets that was blocked by vWF or inhibitory antibodies against GPIb. Ristocetin 38-48 von Willebrand factor Homo sapiens 97-100 9075574-5 1996 Ristocetin-mediated binding of vWF to human platelets promoted a slow rise in Fura-2 fluorescence ratio. Ristocetin 0-10 von Willebrand factor Homo sapiens 31-34 8747526-2 1996 This fragment, VCL, has previously been shown to inhibit vWf-ristocetin, asialo-vWf, and botrocetin-induced vWf binding and aggregation of platelets. Ristocetin 61-71 von Willebrand factor Homo sapiens 57-60 7578899-6 1995 The binding of vWF to GPIb mediated by ristocetin and by botrocetin was inhibited by the patient"s IgG with an IC50s of 0.3 mg/ml and 0.48 mg/ml, respectively. Ristocetin 39-49 von Willebrand factor Homo sapiens 15-18 7559492-3 1995 To validate the methods and reagents used, binding of the same labeled vWF was assessed in the presence of ristocetin or alpha-thrombin and found to be saturable, with a narrow and symmetric distribution on > 90% of the platelets. Ristocetin 107-117 von Willebrand factor Homo sapiens 71-74 7578895-5 1995 Arabs and Africans had higher levels of FVIII:C and vWF:ristocetin cofactor than Westerners. Ristocetin 56-66 von Willebrand factor Homo sapiens 52-55 7537105-1 1995 The interaction between von Willebrand factor (vWF) and glycoprotein Ib (GPIb) induced by ristocetin or botrocetin resulted in associated platelet aggregation, protein tyrosine phosphorylation (PTP) of a 64 kDa protein, as detected by a monoclonal antibody against phosphotyrosine (PY-20), and intracellular Ca2+ elevation that is largely dependent upon Ca2+ influx in human platelets. Ristocetin 90-100 von Willebrand factor Homo sapiens 24-45 8555986-2 1995 The biological activity of vWF was measured by the ristocetin cofactor assay and its multimeric structure was assessed by Western immunoblotting after SDS-agarose gel electrophoresis. Ristocetin 51-61 von Willebrand factor Homo sapiens 27-30 7539426-7 1995 Substitutions at Glu-626 and in the segment Asp-520-Lys-534 abolished ristocetin-induced binding of VWF to GPIb but did not affect botrocetin-induced binding, suggesting that these regions are required for modulation by ristocetin but not for binding of VWF to GPIb. Ristocetin 70-80 von Willebrand factor Homo sapiens 100-103 7539426-7 1995 Substitutions at Glu-626 and in the segment Asp-520-Lys-534 abolished ristocetin-induced binding of VWF to GPIb but did not affect botrocetin-induced binding, suggesting that these regions are required for modulation by ristocetin but not for binding of VWF to GPIb. Ristocetin 70-80 von Willebrand factor Homo sapiens 254-257 7539426-7 1995 Substitutions at Glu-626 and in the segment Asp-520-Lys-534 abolished ristocetin-induced binding of VWF to GPIb but did not affect botrocetin-induced binding, suggesting that these regions are required for modulation by ristocetin but not for binding of VWF to GPIb. Ristocetin 220-230 von Willebrand factor Homo sapiens 100-103 7639074-6 1995 Plasma vWF activity measured as ristocetin cofactor (vWF:RCo) was similar in intercrisis and crisis (100.6 +/- 31 U/dl vs 94.5 +/- 44 U/dl). Ristocetin 32-42 von Willebrand factor Homo sapiens 7-10 7639074-6 1995 Plasma vWF activity measured as ristocetin cofactor (vWF:RCo) was similar in intercrisis and crisis (100.6 +/- 31 U/dl vs 94.5 +/- 44 U/dl). Ristocetin 32-42 von Willebrand factor Homo sapiens 53-56 7720238-0 1995 Four agglutination assays evaluated for measurement of von Willebrand factor (ristocetin cofactor activity) The concentration of von Willebrand factor (vWf) in patients" plasma can be determined by measuring the ristocetin cofactor activity (vWf R:Co). Ristocetin 78-88 von Willebrand factor Homo sapiens 129-150 7720238-0 1995 Four agglutination assays evaluated for measurement of von Willebrand factor (ristocetin cofactor activity) The concentration of von Willebrand factor (vWf) in patients" plasma can be determined by measuring the ristocetin cofactor activity (vWf R:Co). Ristocetin 78-88 von Willebrand factor Homo sapiens 152-155 7495067-6 1995 This mutation which has already been found in several unrelated families with 2B vWD and the increased binding of the patient platelet vWF on normal platelets in the presence of low ristocetin concentrations provide evidence for subtype 2B vWD. Ristocetin 182-192 von Willebrand factor Homo sapiens 135-138 7537105-1 1995 The interaction between von Willebrand factor (vWF) and glycoprotein Ib (GPIb) induced by ristocetin or botrocetin resulted in associated platelet aggregation, protein tyrosine phosphorylation (PTP) of a 64 kDa protein, as detected by a monoclonal antibody against phosphotyrosine (PY-20), and intracellular Ca2+ elevation that is largely dependent upon Ca2+ influx in human platelets. Ristocetin 90-100 von Willebrand factor Homo sapiens 47-50 7887899-0 1995 Promotion of binding of von Willebrand factor to platelet glycoprotein Ib by dimers of ristocetin. Ristocetin 87-97 von Willebrand factor Homo sapiens 24-45 7887899-1 1995 In the absence of high shear forces, the in vitro binding of human von Willebrand factor (vWF) to its platelet receptor glycoprotein Ib (GPIb) can be promoted by two well-characterized mediators, botrocetin and ristocetin. Ristocetin 211-221 von Willebrand factor Homo sapiens 67-88 7887899-1 1995 In the absence of high shear forces, the in vitro binding of human von Willebrand factor (vWF) to its platelet receptor glycoprotein Ib (GPIb) can be promoted by two well-characterized mediators, botrocetin and ristocetin. Ristocetin 211-221 von Willebrand factor Homo sapiens 90-93 7887899-2 1995 Using purified vWF and GPIb, we have investigated the mechanisms by which ristocetin mediates this binding. Ristocetin 74-84 von Willebrand factor Homo sapiens 15-18 7887899-5 1995 With increasing ristocetin concentrations, vWF binding depended progressively less on the involvement of its A1 loop, which is compatible with a model in which the two ristocetin dimers bridge the vWF-GPIb complex on secondary sites. Ristocetin 16-26 von Willebrand factor Homo sapiens 43-46 7887899-5 1995 With increasing ristocetin concentrations, vWF binding depended progressively less on the involvement of its A1 loop, which is compatible with a model in which the two ristocetin dimers bridge the vWF-GPIb complex on secondary sites. Ristocetin 168-178 von Willebrand factor Homo sapiens 43-46 7887899-5 1995 With increasing ristocetin concentrations, vWF binding depended progressively less on the involvement of its A1 loop, which is compatible with a model in which the two ristocetin dimers bridge the vWF-GPIb complex on secondary sites. Ristocetin 168-178 von Willebrand factor Homo sapiens 197-200 7887899-6 1995 In agreement with this model, the ristocetin-dimer-promoted stabilization of vWF on GPIb was abolished by low concentrations of poly(Pro-Gly-Pro), which is known to complex ristocetin dimers. Ristocetin 34-44 von Willebrand factor Homo sapiens 77-80 7887899-6 1995 In agreement with this model, the ristocetin-dimer-promoted stabilization of vWF on GPIb was abolished by low concentrations of poly(Pro-Gly-Pro), which is known to complex ristocetin dimers. Ristocetin 173-183 von Willebrand factor Homo sapiens 77-80 7887899-7 1995 Mechanistic analysis of the inhibition of vWF binding by the recombinant vWF fragment Leu504-Ser728 (VCL), which covers the entire A1 loop, revealed an affinity of VCL for GPIb comparable with that of the botrocetin-vWF complex for GPIb, and identified a specific but 20-fold lower affinity of VCL in the presence of ristocetin. Ristocetin 317-327 von Willebrand factor Homo sapiens 42-45 7887899-7 1995 Mechanistic analysis of the inhibition of vWF binding by the recombinant vWF fragment Leu504-Ser728 (VCL), which covers the entire A1 loop, revealed an affinity of VCL for GPIb comparable with that of the botrocetin-vWF complex for GPIb, and identified a specific but 20-fold lower affinity of VCL in the presence of ristocetin. Ristocetin 317-327 von Willebrand factor Homo sapiens 73-76 7887899-7 1995 Mechanistic analysis of the inhibition of vWF binding by the recombinant vWF fragment Leu504-Ser728 (VCL), which covers the entire A1 loop, revealed an affinity of VCL for GPIb comparable with that of the botrocetin-vWF complex for GPIb, and identified a specific but 20-fold lower affinity of VCL in the presence of ristocetin. Ristocetin 317-327 von Willebrand factor Homo sapiens 73-76 7887899-8 1995 The proline-rich peptides flanking the vWF A1 loop, Cys474-Val489 and Leu694-Asp709, inhibited vWF binding semispecifically by competitively interfering with the formation of the GPIb-vWF complex rather than by complexation of free ristocetin dimers. Ristocetin 232-242 von Willebrand factor Homo sapiens 39-42 7887899-8 1995 The proline-rich peptides flanking the vWF A1 loop, Cys474-Val489 and Leu694-Asp709, inhibited vWF binding semispecifically by competitively interfering with the formation of the GPIb-vWF complex rather than by complexation of free ristocetin dimers. Ristocetin 232-242 von Willebrand factor Homo sapiens 95-98 7887899-8 1995 The proline-rich peptides flanking the vWF A1 loop, Cys474-Val489 and Leu694-Asp709, inhibited vWF binding semispecifically by competitively interfering with the formation of the GPIb-vWF complex rather than by complexation of free ristocetin dimers. Ristocetin 232-242 von Willebrand factor Homo sapiens 95-98 7887899-9 1995 In conclusion, ristocetin-promoted binding of vWF to its GPIb receptor results from charge neutralization and interactions involving proline residues in the vicinity of the natural interaction sites present on both GPIb and the A1 domain of vWF. Ristocetin 15-25 von Willebrand factor Homo sapiens 46-49 7887899-9 1995 In conclusion, ristocetin-promoted binding of vWF to its GPIb receptor results from charge neutralization and interactions involving proline residues in the vicinity of the natural interaction sites present on both GPIb and the A1 domain of vWF. Ristocetin 15-25 von Willebrand factor Homo sapiens 241-244 7532923-4 1994 Furthermore, incubation of PRP with a recombinant fragment of von Willebrand factor (vWF) that abolishes ristocetin-induced platelet agglutination significantly inhibited but did not eliminate SIPA. Ristocetin 105-115 von Willebrand factor Homo sapiens 62-83 21043709-4 1995 Binding of vWF to the GP Ib-IX complex involves the vWF A1 internal repeat domain, which also contains distinct binding sites for sulfatides, heparin, and the non-physiological modulators of the vWF-GP Ib-IX interaction, ristocetin and botrocetin. Ristocetin 221-231 von Willebrand factor Homo sapiens 11-14 21043709-4 1995 Binding of vWF to the GP Ib-IX complex involves the vWF A1 internal repeat domain, which also contains distinct binding sites for sulfatides, heparin, and the non-physiological modulators of the vWF-GP Ib-IX interaction, ristocetin and botrocetin. Ristocetin 221-231 von Willebrand factor Homo sapiens 52-55 21043709-4 1995 Binding of vWF to the GP Ib-IX complex involves the vWF A1 internal repeat domain, which also contains distinct binding sites for sulfatides, heparin, and the non-physiological modulators of the vWF-GP Ib-IX interaction, ristocetin and botrocetin. Ristocetin 221-231 von Willebrand factor Homo sapiens 52-55 21043709-9 1995 Thirdly, many of the compounds tested that inhibited binding of vWF to heparin also effectively inhibited both ristocetin- and botrocetin-dependent binding of vWF to the GP Ib-IX complex on platelets, whereas none of the compounds tested blocked vWF binding to sulfatides and GP Ib-IX but not heparin. Ristocetin 111-121 von Willebrand factor Homo sapiens 64-67 21043709-9 1995 Thirdly, many of the compounds tested that inhibited binding of vWF to heparin also effectively inhibited both ristocetin- and botrocetin-dependent binding of vWF to the GP Ib-IX complex on platelets, whereas none of the compounds tested blocked vWF binding to sulfatides and GP Ib-IX but not heparin. Ristocetin 111-121 von Willebrand factor Homo sapiens 159-162 21043709-9 1995 Thirdly, many of the compounds tested that inhibited binding of vWF to heparin also effectively inhibited both ristocetin- and botrocetin-dependent binding of vWF to the GP Ib-IX complex on platelets, whereas none of the compounds tested blocked vWF binding to sulfatides and GP Ib-IX but not heparin. Ristocetin 111-121 von Willebrand factor Homo sapiens 159-162 21043709-10 1995 The majority of compounds tested inhibited the vWF-platelet interaction to a comparable degree in the presence of ristocetin or botrocetin, suggesting a similar mechanism for inhibition irrespective of the modulator used. Ristocetin 114-124 von Willebrand factor Homo sapiens 47-50 7900092-7 1994 Ristocetin stimulation of the patients" platelets in the presence of plasma resulted in a low binding of vWF, about 30% of healthy controls. Ristocetin 0-10 von Willebrand factor Homo sapiens 105-108 7949092-2 1994 Coagulation studies showed a von Willebrand factor (vWF) defect (Ivy bleeding time, > 15 minutes; vWF antigen [vWF:Ag], 0.08 U/mL; ristocetin cofactor activity [vWF:RCoF], < 0.05 U/mL; collagen binding activity [vWF:CBA], 0.01 U/mL; absence of the high molecular weight multimers of vWF on multimeric analysis). Ristocetin 134-144 von Willebrand factor Homo sapiens 52-55 7871492-3 1994 The ristocetin-induced agglutination was inhibited in a TMS concentration-dependent manner, which suggests that TMS may interact with the vWF receptor on platelets. Ristocetin 4-14 von Willebrand factor Homo sapiens 138-141 7819071-5 1994 In concentration dependent binding to botrocetin- or ristocetin-stimulated platelets, 125I-plasma vWf bound with a higher affinity than platelet. Ristocetin 53-63 von Willebrand factor Homo sapiens 98-101 7819071-6 1994 The ristocetin cofactor activity per mg of purified plasma vWf was 5-fold greater than the platelet vWf activity. Ristocetin 4-14 von Willebrand factor Homo sapiens 59-62 7532923-4 1994 Furthermore, incubation of PRP with a recombinant fragment of von Willebrand factor (vWF) that abolishes ristocetin-induced platelet agglutination significantly inhibited but did not eliminate SIPA. Ristocetin 105-115 von Willebrand factor Homo sapiens 85-88 7803236-5 1994 The only way to cause GPIb/IX to move was to add anti-vWF to thrombin-activated platelets allowed to spread on formvar grids and covered with multimers of ristocetin-activated human or bovine vWF. Ristocetin 155-165 von Willebrand factor Homo sapiens 54-57 7777905-9 1994 Defective aggregation to ristocetin would indicate abnormal von Willebrand"s factor (vWF). Ristocetin 25-35 von Willebrand factor Homo sapiens 60-83 7777905-9 1994 Defective aggregation to ristocetin would indicate abnormal von Willebrand"s factor (vWF). Ristocetin 25-35 von Willebrand factor Homo sapiens 85-88 8120035-8 1994 Furthermore, recombinant vWF with Gly or Ala at all three positions induces platelet aggregation in the presence of ristocetin and binds to platelet glycoprotein Ib, factor VIII, and collagen in a manner similar to wild-type recombinant vWF. Ristocetin 116-126 von Willebrand factor Homo sapiens 25-28 7997978-1 1994 The quantitative determinations of von Willebrand Factor (vWF)-Ristocetin cofactor (vWF:RCof) and the Botrocetin cofactor (vWF:BCof) are important parameters for the diagnosis of von Willebrand"s disease. Ristocetin 63-73 von Willebrand factor Homo sapiens 58-61 7997978-1 1994 The quantitative determinations of von Willebrand Factor (vWF)-Ristocetin cofactor (vWF:RCof) and the Botrocetin cofactor (vWF:BCof) are important parameters for the diagnosis of von Willebrand"s disease. Ristocetin 63-73 von Willebrand factor Homo sapiens 84-87 7997978-1 1994 The quantitative determinations of von Willebrand Factor (vWF)-Ristocetin cofactor (vWF:RCof) and the Botrocetin cofactor (vWF:BCof) are important parameters for the diagnosis of von Willebrand"s disease. Ristocetin 63-73 von Willebrand factor Homo sapiens 84-87 8204881-3 1994 Functions of vWF were analyzed by binding assays to platelets in the presence of ristocetin or botrocetin. Ristocetin 81-91 von Willebrand factor Homo sapiens 13-16 8204881-5 1994 We found that ristocetin- or botrocetin-induced binding to platelets was correlated in all cases with the size of vWF multimers. Ristocetin 14-24 von Willebrand factor Homo sapiens 114-117 8051492-1 1994 Platelet membrane glycoproteins Ib (GPIb) and IIb/IIIa (GPIIb/IIIa) bind soluble von Willebrand factor (vWf) after stimulation with ristocetin (GPIb) or with thrombin or ADP (GPIIb/IIIa). Ristocetin 132-142 von Willebrand factor Homo sapiens 81-102 8051492-1 1994 Platelet membrane glycoproteins Ib (GPIb) and IIb/IIIa (GPIIb/IIIa) bind soluble von Willebrand factor (vWf) after stimulation with ristocetin (GPIb) or with thrombin or ADP (GPIIb/IIIa). Ristocetin 132-142 von Willebrand factor Homo sapiens 104-107 8229521-3 1993 METHODS: Von Willebrand factor (vWF) was measured by the ristocetin cofactor method in 600 healthy children, aged 2 to 18 years, seen for routine school physical examinations in a three-state region. Ristocetin 57-67 von Willebrand factor Homo sapiens 9-30 8141116-2 1994 After 5 days of storage, 82 +/- 9% of basal levels of ristocetin cofactor activity (vWF:RCo) remained in PCs. Ristocetin 54-64 von Willebrand factor Homo sapiens 84-87 8250006-3 1994 Interestingly, we found a significant decrease of immunoreactive GP Ib molecules (9,978 +/- 1,534 vs. 17,064 +/- 404 molecules per platelet) and ristocetin-dependent binding of vWF (9,113 +/- 1,338 vs. 13,992 +/- 1,968 molecules per platelet) (P < 0.01) in comparison to the levels found in a control group of healthy subjects. Ristocetin 145-155 von Willebrand factor Homo sapiens 177-180 8250006-5 1994 The ristocetin-induced platelet agglutination (light transmission %) was also significantly lower in patients with cirrhosis (48 +/- 7.6 vs. 92 +/- 3.6, P < 0.01), and correlated with the binding of normal vWF (r = 0.863, P = 0.0013). Ristocetin 4-14 von Willebrand factor Homo sapiens 209-212 8229521-3 1993 METHODS: Von Willebrand factor (vWF) was measured by the ristocetin cofactor method in 600 healthy children, aged 2 to 18 years, seen for routine school physical examinations in a three-state region. Ristocetin 57-67 von Willebrand factor Homo sapiens 32-35 8376606-7 1993 Here we report that vWF-dependent aggregation occurs under low shear stress in citrated platelet-rich plasma (PRP) from two types of congenital bleeding disorders, platelet-type von Willebrand disease (vWD) and type IIB vWD, in both of which ristocetin-induced aggregation is known to be heightened. Ristocetin 242-252 von Willebrand factor Homo sapiens 20-23 8376405-7 1993 Relative to wild type vWF, the mutant vWF exhibited markedly increased binding to platelets at low concentrations of ristocetin, confirming the association between the His-505-->Asp substitution and the type IIB vWD phenotype. Ristocetin 117-127 von Willebrand factor Homo sapiens 38-41 8367835-3 1993 GPIb function, as evaluated by measuring vWF-dependent, ristocetin-induced platelet agglutination in human platelet rich plasma (PRP) was significantly impaired following incubation with plasmin (60 +/- 14% inhibition, p < 0.01). Ristocetin 56-66 von Willebrand factor Homo sapiens 41-44 8457648-4 1993 Type I vWd was diagnosed because of a concomitant decrease of von Willebrand factor antigen (vWf:Ag) and vWf ristocetin-cofactor activity (vWf:RCoF), associated with the presence of vWf multimers of all sizes in plasma and platelets. Ristocetin 109-119 von Willebrand factor Homo sapiens 105-108 8483792-1 1993 We synthesized peptides of the general formula Argn, Lysn, and (Lys-Arg)n. These agents inhibited the ristocetin-mediated binding of vWF to GPIb and the binding of asialo-vWF to platelets. Ristocetin 102-112 von Willebrand factor Homo sapiens 133-136 8483792-1 1993 We synthesized peptides of the general formula Argn, Lysn, and (Lys-Arg)n. These agents inhibited the ristocetin-mediated binding of vWF to GPIb and the binding of asialo-vWF to platelets. Ristocetin 102-112 von Willebrand factor Homo sapiens 171-174 8438875-2 1993 Individuals with type I von Willebrand"s disease (vWd) with prolonged bleeding times are best discriminated from those who have normal bleeding times by the normal level of platelet vWf ristocetin cofactor activity (vWf activity) and, to a lesser extent, by their platelet vWf antigen content. Ristocetin 186-196 von Willebrand factor Homo sapiens 182-185 8426951-1 1993 We report two cases of von Willebrand (type I) disease with vWF antigen levels of 21 and 25%, vWF ristocetin cofactor concentrations of 32 and 30%, and coagulation FVIII levels of 10 and 50% respectively. Ristocetin 98-108 von Willebrand factor Homo sapiens 94-97 8457648-4 1993 Type I vWd was diagnosed because of a concomitant decrease of von Willebrand factor antigen (vWf:Ag) and vWf ristocetin-cofactor activity (vWf:RCoF), associated with the presence of vWf multimers of all sizes in plasma and platelets. Ristocetin 109-119 von Willebrand factor Homo sapiens 105-108 8457648-4 1993 Type I vWd was diagnosed because of a concomitant decrease of von Willebrand factor antigen (vWf:Ag) and vWf ristocetin-cofactor activity (vWf:RCoF), associated with the presence of vWf multimers of all sizes in plasma and platelets. Ristocetin 109-119 von Willebrand factor Homo sapiens 105-108 8423224-1 1993 We developed a monoclonal antibody, 1C1E7, against vWf that increases ristocetin-induced platelet aggregation in a dose-dependent manner and lowers the threshold concentration of ristocetin needed to obtain a full aggregatory response. Ristocetin 70-80 von Willebrand factor Homo sapiens 51-54 8423224-1 1993 We developed a monoclonal antibody, 1C1E7, against vWf that increases ristocetin-induced platelet aggregation in a dose-dependent manner and lowers the threshold concentration of ristocetin needed to obtain a full aggregatory response. Ristocetin 179-189 von Willebrand factor Homo sapiens 51-54 8423224-3 1993 In the presence of ristocetin, both intact 1C1E7 and its Fab fragments enhance specific binding of 125I-vWf to platelets. Ristocetin 19-29 von Willebrand factor Homo sapiens 104-107 21043845-4 1993 Binding assays and flow cytometry with antibodies against GPs Ib/IX and IIb/IIIa, the study of the ristocetin-dependent vWF binding, and immunoblotting with an anti-GPIb/IX antibody, demonstrated no quantitative or functional changes of these complexes after the infusion of DDAVP. Ristocetin 99-109 von Willebrand factor Homo sapiens 120-123 1287886-5 1992 ATA completely abolished vWF-dependent platelet agglutination induced by ristocetin, botrocetin and asialo-vWF, respectively. Ristocetin 73-83 von Willebrand factor Homo sapiens 25-28 1287886-6 1992 125I-vWF binding to ristocetin- and botrocetin-treated platelets, to heparin and to sulfatides as well as 125I-botrocetin binding to vWF was competitively inhibited by ATA. Ristocetin 20-30 von Willebrand factor Homo sapiens 5-8 1469086-0 1992 O-linked carbohydrate of recombinant von Willebrand factor influences ristocetin-induced binding to platelet glycoprotein 1b. Ristocetin 70-80 von Willebrand factor Homo sapiens 37-58 1469086-7 1992 These data indicate a possible role for O-linked carbohydrates in the vWf-glycoprotein 1b interaction promoted by ristocetin and suggest that abnormalities in carbohydrate modification might contribute to the altered ristocetin-dependent reactivity between vWf and platelets described for some variant forms of von Willebrand disease. Ristocetin 114-124 von Willebrand factor Homo sapiens 70-73 1609773-4 1992 In the presence of ristocetin, binding of the patient"s plasma vWF to normal platelets was increased but binding of normal vWF to his platelets was normal. Ristocetin 19-29 von Willebrand factor Homo sapiens 63-66 1409710-0 1992 von Willebrand disease type B: a missense mutation selectively abolishes ristocetin-induced von Willebrand factor binding to platelet glycoprotein Ib. Ristocetin 73-83 von Willebrand factor Homo sapiens 92-113 1409710-2 1992 For human vWF, this interaction can be induced in vitro by the antibiotic ristocetin or the snake venom protein botrocetin. Ristocetin 74-84 von Willebrand factor Homo sapiens 10-13 1409710-3 1992 A missense mutation, Gly-561-->Ser, was identified within the proposed glycoprotein Ib binding domain of vWF in the proband with von Willebrand disease type B, a unique variant characterized by no ristocetin-induced, but normal botrocetin-induced, binding to glycoprotein Ib. Ristocetin 200-210 von Willebrand factor Homo sapiens 108-111 1409710-5 1992 These data show that botrocetin and ristocetin cofactor activities of vWF can be dissociated by a point mutation and confirm that these mediators promote vWF binding to platelets by different mechanisms. Ristocetin 36-46 von Willebrand factor Homo sapiens 70-73 1409710-6 1992 The normal botrocetin-induced binding and the defective ristocetin-induced binding of rvWF(G561S) suggest that the primary defect in von Willebrand disease type B may be a failure of normal allosteric regulation of the glycoprotein Ib binding function of vWF. Ristocetin 56-66 von Willebrand factor Homo sapiens 87-90 1412167-4 1992 Soluble rGpIb alpha L318 harvested from COS cell-conditioned medium inhibited ristocetin-dependent binding of [125I]-vWF to fixed washed human platelets (IC50 20 nM). Ristocetin 78-88 von Willebrand factor Homo sapiens 117-120 1280375-5 1992 Among several anti-vWF monoclonal antibodies (MoAbs) which inhibit ristocetin-induced platelet aggregation and/or vWF binding to GP Ib, only two MoAbs (NMC-4 and RFF-VIII RAG:1) abolished direct binding between purified botrocetin and vWF. Ristocetin 67-77 von Willebrand factor Homo sapiens 19-22 1295515-1 1992 Ristocetin induces a conformational change on von Willebrand Factor (vWF) similar to that due to the interaction with the subendothelium, by which the former can interact with the Glycoprotein-1 B (GPIB) of the platelet membrane and trigger aggregation and granule content secretion. Ristocetin 0-10 von Willebrand factor Homo sapiens 46-67 1295515-1 1992 Ristocetin induces a conformational change on von Willebrand Factor (vWF) similar to that due to the interaction with the subendothelium, by which the former can interact with the Glycoprotein-1 B (GPIB) of the platelet membrane and trigger aggregation and granule content secretion. Ristocetin 0-10 von Willebrand factor Homo sapiens 69-72 1420815-5 1992 After cryoprecipitation the supernatant, which contained predominantly low-molecular-weight vWF multimers, was effective with ristocetin only after prior incubation of the platelets with dibucaine. Ristocetin 126-136 von Willebrand factor Homo sapiens 92-95 1420815-6 1992 This indicates that low-molecular-weight vWF multimers can also support ristocetin-induced aggregation when the membrane fluidity is increased. Ristocetin 72-82 von Willebrand factor Homo sapiens 41-44 1643023-6 1992 In all cases, fetal vWF was able to interact with factor VIII and to bind to GP Ib platelet receptor in the presence of ristocetin and to types I and III collagen. Ristocetin 120-130 von Willebrand factor Homo sapiens 20-23 1562727-4 1992 When unstirred platelet-rich plasma was incubated with ristocetin, bound vWF was located by Au-EM as discrete masses regularly distributed over the cell surface. Ristocetin 55-65 von Willebrand factor Homo sapiens 73-76 1513036-4 1992 All synthetic peptides inhibited both vWf binding to GPIb, ristocetin-induced platelet aggregation and asialo vWf-induced platelet aggregation. Ristocetin 59-69 von Willebrand factor Homo sapiens 38-41 1562727-8 1992 Under these conditions, platelets were treated with ristocetin for 5 minutes at 37 degrees C in the presence of increasing amounts of purified vWF. Ristocetin 52-62 von Willebrand factor Homo sapiens 143-146 1557393-4 1992 vWF from a human umbilical vein endothelial cell culture heterozygous for the vWF R543W mutation showed markedly increased binding of large vWF multimers to platelets in the presence of a low dose of ristocetin compared to vWF from a normal control culture. Ristocetin 200-210 von Willebrand factor Homo sapiens 0-3 1557393-4 1992 vWF from a human umbilical vein endothelial cell culture heterozygous for the vWF R543W mutation showed markedly increased binding of large vWF multimers to platelets in the presence of a low dose of ristocetin compared to vWF from a normal control culture. Ristocetin 200-210 von Willebrand factor Homo sapiens 78-81 1557393-4 1992 vWF from a human umbilical vein endothelial cell culture heterozygous for the vWF R543W mutation showed markedly increased binding of large vWF multimers to platelets in the presence of a low dose of ristocetin compared to vWF from a normal control culture. Ristocetin 200-210 von Willebrand factor Homo sapiens 78-81 1557393-4 1992 vWF from a human umbilical vein endothelial cell culture heterozygous for the vWF R543W mutation showed markedly increased binding of large vWF multimers to platelets in the presence of a low dose of ristocetin compared to vWF from a normal control culture. Ristocetin 200-210 von Willebrand factor Homo sapiens 78-81 1737795-4 1992 High molecular weight RADS-vWF and RGES-vWF multimers inhibited binding of 125I-vWF to a mixture of insolubilized native type I and III collagen and competed effectively with 125I-vWF for binding to formalin-fixed platelets in the presence of ristocetin, indicating functional collagen and platelet glycoprotein Ib binding. Ristocetin 243-253 von Willebrand factor Homo sapiens 27-30 1737795-4 1992 High molecular weight RADS-vWF and RGES-vWF multimers inhibited binding of 125I-vWF to a mixture of insolubilized native type I and III collagen and competed effectively with 125I-vWF for binding to formalin-fixed platelets in the presence of ristocetin, indicating functional collagen and platelet glycoprotein Ib binding. Ristocetin 243-253 von Willebrand factor Homo sapiens 40-43 1737795-4 1992 High molecular weight RADS-vWF and RGES-vWF multimers inhibited binding of 125I-vWF to a mixture of insolubilized native type I and III collagen and competed effectively with 125I-vWF for binding to formalin-fixed platelets in the presence of ristocetin, indicating functional collagen and platelet glycoprotein Ib binding. Ristocetin 243-253 von Willebrand factor Homo sapiens 40-43 1737795-4 1992 High molecular weight RADS-vWF and RGES-vWF multimers inhibited binding of 125I-vWF to a mixture of insolubilized native type I and III collagen and competed effectively with 125I-vWF for binding to formalin-fixed platelets in the presence of ristocetin, indicating functional collagen and platelet glycoprotein Ib binding. Ristocetin 243-253 von Willebrand factor Homo sapiens 40-43 1730088-6 1992 The kd for 125I-vWF binding to patients platelets was significantly increased over control values at 0.5 mg/mL ristocetin, but was normal at 1.0 or 1.5 mg/mL ristocetin. Ristocetin 111-121 von Willebrand factor Homo sapiens 16-19 1730088-6 1992 The kd for 125I-vWF binding to patients platelets was significantly increased over control values at 0.5 mg/mL ristocetin, but was normal at 1.0 or 1.5 mg/mL ristocetin. Ristocetin 158-168 von Willebrand factor Homo sapiens 16-19 1724577-4 1991 A marked reduction in the placebo group of ristocetin-induced platelet agglutination (binding of von Willebrand factor [vWF] to platelet glycoprotein [GP] Ib) was shown during ECC and at the end of surgery, but not in the aprotinin group. Ristocetin 43-53 von Willebrand factor Homo sapiens 97-118 1585777-2 1992 The profile of plasma von Willebrand factor (vWF) revealed decreased ristocetin cofactor activity and diminished large multimers of vWF in spite of a normal vWF antigen level. Ristocetin 69-79 von Willebrand factor Homo sapiens 22-43 1585777-2 1992 The profile of plasma von Willebrand factor (vWF) revealed decreased ristocetin cofactor activity and diminished large multimers of vWF in spite of a normal vWF antigen level. Ristocetin 69-79 von Willebrand factor Homo sapiens 45-48 1530813-3 1992 The ristocetin cofactor (RiCof) activity of vWF, high before therapy, tended to decrease soon after therapy. Ristocetin 4-14 von Willebrand factor Homo sapiens 44-47 1939217-5 1991 The mutant vWF molecules were also assayed for their function in ristocetin-induced platelet agglutination mediated through the platelet receptor GPIb. Ristocetin 65-75 von Willebrand factor Homo sapiens 11-14 1579897-1 1992 Von Willebrand"s disease (vWD) "Vicenza" is characterized by low plasma von Willebrand Factor antigen (vWF:Ag) and very low levels of Ristocetin Cofactor activity (RiCof). Ristocetin 134-144 von Willebrand factor Homo sapiens 26-29 1733754-3 1992 A decrease in factor VIII:C was noted in 33%, a decrease in von Willebrand factor (vWF:Ag) was noted in 83% and a decrease in ristocetin-cofactor activity (vWF:Rcof) was noted in 66% of the children. Ristocetin 126-136 von Willebrand factor Homo sapiens 156-159 1939645-4 1991 PA production, PKC activation, and the rise of [Ca2+]i stimulated by the ristocetin-induced binding of vWF multimers to platelets are inhibited by an anti-GpIb monoclonal antibody, but are unaffected by anti-GpIIb-IIIa monoclonal antibodies. Ristocetin 73-83 von Willebrand factor Homo sapiens 103-106 1724577-4 1991 A marked reduction in the placebo group of ristocetin-induced platelet agglutination (binding of von Willebrand factor [vWF] to platelet glycoprotein [GP] Ib) was shown during ECC and at the end of surgery, but not in the aprotinin group. Ristocetin 43-53 von Willebrand factor Homo sapiens 120-123 2011604-6 1991 In contrast, mammalian cell expression of the same segment of sequence yielded molecules that, when containing the normal Trp550, did not bind to GP Ib directly but, like native vWF, bound in the presence of ristocetin. Ristocetin 208-218 von Willebrand factor Homo sapiens 178-181 1870263-5 1991 In vitro, an antibiotic ristocetin or the snake venom botrocetin isolated from Bothrops jararaca mimics the active component of subendothelial matrix and causes the binding of vWF to GP Ib. Ristocetin 24-34 von Willebrand factor Homo sapiens 176-179 1768767-4 1991 RIPA was completely inhibited by an anti-glycoprotein (GP) Ib monoclonal antibody that recognizes the ristocetin-induced vWf binding site. Ristocetin 102-112 von Willebrand factor Homo sapiens 121-124 1906179-3 1991 The corresponding mutant recombinant vWF(T28M) formed normal multimers and had normal ristocetin cofactor activity. Ristocetin 86-96 von Willebrand factor Homo sapiens 37-40 2022745-4 1991 Heparin also inhibited platelet agglutination induced by bovine vWF and inhibited the binding of human asialo-vWF to platelets in ristocetin-free systems. Ristocetin 130-140 von Willebrand factor Homo sapiens 110-113 2011604-7 1991 However, molecules containing the point mutation (Cys550) behaved like type IIB vWF--namely, bound to GP Ib even without ristocetin modulation and, in the presence of ristocetin, had 10-fold higher affinity than molecules with normal sequence. Ristocetin 121-131 von Willebrand factor Homo sapiens 80-83 2011604-7 1991 However, molecules containing the point mutation (Cys550) behaved like type IIB vWF--namely, bound to GP Ib even without ristocetin modulation and, in the presence of ristocetin, had 10-fold higher affinity than molecules with normal sequence. Ristocetin 167-177 von Willebrand factor Homo sapiens 80-83 1984791-0 1991 Studies on anti-von Willebrand factor (vWF) monoclonal antibody NMC-4, which inhibits both ristocetin- and botrocetin-induced vWF binding to platelet glycoprotein Ib. Ristocetin 91-101 von Willebrand factor Homo sapiens 11-37 1772996-11 1991 In contrast, a MAb against ristocetin-induced vWf binding site on GPIb did not affect SPA. Ristocetin 27-37 von Willebrand factor Homo sapiens 46-49 1984791-0 1991 Studies on anti-von Willebrand factor (vWF) monoclonal antibody NMC-4, which inhibits both ristocetin- and botrocetin-induced vWF binding to platelet glycoprotein Ib. Ristocetin 91-101 von Willebrand factor Homo sapiens 39-42 1984791-1 1991 Anti-von Willebrand factor (vWF) monoclonal antibody NMC-4 completely inhibited vWF binding to platelet glycoprotein (GP) lb induced by either ristocetin or botrocetin at an IgG concentration of approximately 10 micrograms/mL, and also blocked binding of asialo-vWF to GP lb. Ristocetin 143-153 von Willebrand factor Homo sapiens 0-26 1984791-1 1991 Anti-von Willebrand factor (vWF) monoclonal antibody NMC-4 completely inhibited vWF binding to platelet glycoprotein (GP) lb induced by either ristocetin or botrocetin at an IgG concentration of approximately 10 micrograms/mL, and also blocked binding of asialo-vWF to GP lb. Ristocetin 143-153 von Willebrand factor Homo sapiens 28-31 1984791-1 1991 Anti-von Willebrand factor (vWF) monoclonal antibody NMC-4 completely inhibited vWF binding to platelet glycoprotein (GP) lb induced by either ristocetin or botrocetin at an IgG concentration of approximately 10 micrograms/mL, and also blocked binding of asialo-vWF to GP lb. Ristocetin 143-153 von Willebrand factor Homo sapiens 80-83 1984791-1 1991 Anti-von Willebrand factor (vWF) monoclonal antibody NMC-4 completely inhibited vWF binding to platelet glycoprotein (GP) lb induced by either ristocetin or botrocetin at an IgG concentration of approximately 10 micrograms/mL, and also blocked binding of asialo-vWF to GP lb. Ristocetin 143-153 von Willebrand factor Homo sapiens 80-83 1984791-6 1991 Fr III-T2 completely inhibited ristocetin-induced vWF binding at a concentration of 100 mumol/L but had no effect on botrocetin-induced binding. Ristocetin 31-41 von Willebrand factor Homo sapiens 50-53 1949703-2 1991 The functional activity of vWF assessed by its ristocetin cofactor activity (vWF:RCo) correlated with the level of vWF antigen (vWF:Ag), with the vWF:RCo/vWF:Ag ratios ranging from 0.56 to 1.02, and the specific activity being always greater than 50 IU vWF:RCo/mg protein. Ristocetin 47-57 von Willebrand factor Homo sapiens 27-30 1823880-2 1991 Both OP-F1 and a well-characterized anti-GPIb MoAb, AP-1, totally abolished ristocetin-induced von Willebrand factor (vWF) binding to platelets and desialylated vWF binding to platelets at an IgG concentration of 2-8 micrograms/ml. Ristocetin 76-86 von Willebrand factor Homo sapiens 118-121 1949703-2 1991 The functional activity of vWF assessed by its ristocetin cofactor activity (vWF:RCo) correlated with the level of vWF antigen (vWF:Ag), with the vWF:RCo/vWF:Ag ratios ranging from 0.56 to 1.02, and the specific activity being always greater than 50 IU vWF:RCo/mg protein. Ristocetin 47-57 von Willebrand factor Homo sapiens 77-80 1949703-2 1991 The functional activity of vWF assessed by its ristocetin cofactor activity (vWF:RCo) correlated with the level of vWF antigen (vWF:Ag), with the vWF:RCo/vWF:Ag ratios ranging from 0.56 to 1.02, and the specific activity being always greater than 50 IU vWF:RCo/mg protein. Ristocetin 47-57 von Willebrand factor Homo sapiens 77-80 1949703-2 1991 The functional activity of vWF assessed by its ristocetin cofactor activity (vWF:RCo) correlated with the level of vWF antigen (vWF:Ag), with the vWF:RCo/vWF:Ag ratios ranging from 0.56 to 1.02, and the specific activity being always greater than 50 IU vWF:RCo/mg protein. Ristocetin 47-57 von Willebrand factor Homo sapiens 77-80 1949703-2 1991 The functional activity of vWF assessed by its ristocetin cofactor activity (vWF:RCo) correlated with the level of vWF antigen (vWF:Ag), with the vWF:RCo/vWF:Ag ratios ranging from 0.56 to 1.02, and the specific activity being always greater than 50 IU vWF:RCo/mg protein. Ristocetin 47-57 von Willebrand factor Homo sapiens 77-80 1949703-2 1991 The functional activity of vWF assessed by its ristocetin cofactor activity (vWF:RCo) correlated with the level of vWF antigen (vWF:Ag), with the vWF:RCo/vWF:Ag ratios ranging from 0.56 to 1.02, and the specific activity being always greater than 50 IU vWF:RCo/mg protein. Ristocetin 47-57 von Willebrand factor Homo sapiens 77-80 1949703-2 1991 The functional activity of vWF assessed by its ristocetin cofactor activity (vWF:RCo) correlated with the level of vWF antigen (vWF:Ag), with the vWF:RCo/vWF:Ag ratios ranging from 0.56 to 1.02, and the specific activity being always greater than 50 IU vWF:RCo/mg protein. Ristocetin 47-57 von Willebrand factor Homo sapiens 77-80 1949703-4 1991 The biological activity of vWF was also evaluated by studying its ability to bind to collagen and to platelet receptors in the presence of either ristocetin or thrombin. Ristocetin 146-156 von Willebrand factor Homo sapiens 27-30 1702906-0 1990 Ristocetin and botrocetin involve two distinct domains of von Willebrand factor for binding to platelet membrane glycoprotein Ib. Ristocetin 0-10 von Willebrand factor Homo sapiens 58-79 2245394-5 1990 Levels of von Willebrand factor (vWF), both antigenic and functional (ristocetin cofactor), were elevated. Ristocetin 70-80 von Willebrand factor Homo sapiens 10-31 2245394-5 1990 Levels of von Willebrand factor (vWF), both antigenic and functional (ristocetin cofactor), were elevated. Ristocetin 70-80 von Willebrand factor Homo sapiens 33-36 1702906-1 1990 We have evidence that ristocetin and botrocetin mediate binding of von Willebrand Factor (vWF) to platelet glycoprotein Ib (GPIb) through two distinct domains on the vWF molecule. Ristocetin 22-32 von Willebrand factor Homo sapiens 67-88 1702906-1 1990 We have evidence that ristocetin and botrocetin mediate binding of von Willebrand Factor (vWF) to platelet glycoprotein Ib (GPIb) through two distinct domains on the vWF molecule. Ristocetin 22-32 von Willebrand factor Homo sapiens 90-93 1702906-1 1990 We have evidence that ristocetin and botrocetin mediate binding of von Willebrand Factor (vWF) to platelet glycoprotein Ib (GPIb) through two distinct domains on the vWF molecule. Ristocetin 22-32 von Willebrand factor Homo sapiens 166-169 1702906-5 1990 Both MAbs inhibit 125I-vWF binding to platelet membrane GPIb and vWF-dependent platelet agglutination induced by ristocetin. Ristocetin 113-123 von Willebrand factor Homo sapiens 23-26 1702906-5 1990 Both MAbs inhibit 125I-vWF binding to platelet membrane GPIb and vWF-dependent platelet agglutination induced by ristocetin. Ristocetin 113-123 von Willebrand factor Homo sapiens 65-68 1702906-7 1990 The involvement of two distinct domains of vWF for binding to GPIb in the presence of ristocetin or botrocetin was confirmed in experiments of binding of 125I-vWF to platelets using a competitor synthetic peptides corresponding to the GPIb binding domain of vWF (Cys 474 to Pro 488 and Ser 692 to Pro 708). Ristocetin 86-96 von Willebrand factor Homo sapiens 43-46 1702906-8 1990 At a final concentration of 2.5 mM both peptides inhibit more than 90% of the binding of vWF to ristocetin-treated platelets but are unable to modify this binding in the presence of botrocetin. Ristocetin 96-106 von Willebrand factor Homo sapiens 89-92 1702906-9 1990 In conclusion our data suggest that botrocetin and ristocetin involve distinct sites on vWF for binding to GPIb. Ristocetin 51-61 von Willebrand factor Homo sapiens 88-91 2394830-8 1990 Thus, IIB vWF binds to GP Ib-IX with high affinity and induces platelet aggregation, whether with or without ristocetin, in spite of the absence of larger multimers. Ristocetin 109-119 von Willebrand factor Homo sapiens 10-13 2375928-6 1990 Aggregation induced by patient plasma could also be blocked either by two monoclonal antibodies raised against vWF or by a fragment derived from trypsin digestion of normal vWF which blocks the ristocetin-induced binding of normal vWF to platelets. Ristocetin 194-204 von Willebrand factor Homo sapiens 173-176 2401846-4 1990 Equal amounts of vWf were eluted from ristocetin/vWf-treated platelets when they were resuspended without ristocetin, whether or not the platelets had been exposed to ADP, and the vWf recovered in either case was composed only of large multimers. Ristocetin 38-48 von Willebrand factor Homo sapiens 17-20 2214316-3 1990 Ristocetin-induced vWF:Ag binding to platelets by using 125I-vWF was significantly increased. Ristocetin 0-10 von Willebrand factor Homo sapiens 19-22 2214316-3 1990 Ristocetin-induced vWF:Ag binding to platelets by using 125I-vWF was significantly increased. Ristocetin 0-10 von Willebrand factor Homo sapiens 61-64 2246822-5 1990 In vitro, the patient"s plasma exhibited inhibitory activity against vWF: ristocetin cofactor activity (vWF: Rco) but had no effect on RIPA. Ristocetin 74-84 von Willebrand factor Homo sapiens 69-72 2246822-5 1990 In vitro, the patient"s plasma exhibited inhibitory activity against vWF: ristocetin cofactor activity (vWF: Rco) but had no effect on RIPA. Ristocetin 74-84 von Willebrand factor Homo sapiens 104-107 2214174-6 1990 The analysis of plasma von Willebrand factor (vWF) revealed the decrease of ristocetin cofactor activity and the lack of large multimeric components of vWF. Ristocetin 76-86 von Willebrand factor Homo sapiens 23-44 2214174-6 1990 The analysis of plasma von Willebrand factor (vWF) revealed the decrease of ristocetin cofactor activity and the lack of large multimeric components of vWF. Ristocetin 76-86 von Willebrand factor Homo sapiens 46-49 2375928-6 1990 Aggregation induced by patient plasma could also be blocked either by two monoclonal antibodies raised against vWF or by a fragment derived from trypsin digestion of normal vWF which blocks the ristocetin-induced binding of normal vWF to platelets. Ristocetin 194-204 von Willebrand factor Homo sapiens 173-176 2316510-1 1990 Botrocetin, a protein isolated from the venom of the snake Bothrops jararaca, induces platelet aggregation/agglutination by von Willebrand factor (vWF) binding to the membrane glycoprotein (GP) Ib, an action resembling that of ristocetin. Ristocetin 227-237 von Willebrand factor Homo sapiens 147-150 2339348-1 1990 Platelet membrane glycoprotein Ib (GPIb) functions as receptors for thrombin and von Willebrand factor (vWF) in the presence of ristocetin. Ristocetin 128-138 von Willebrand factor Homo sapiens 104-107 2196663-3 1990 The first is based on the interaction between vWf and Gp Ib of the platelet membrane in presence of ristocetin (ristocetin cofactor activity, RiCof) and depends not only on the amount of the factor but also on its ability to bring about this interaction, large multimers being more active. Ristocetin 100-110 von Willebrand factor Homo sapiens 46-49 2196663-3 1990 The first is based on the interaction between vWf and Gp Ib of the platelet membrane in presence of ristocetin (ristocetin cofactor activity, RiCof) and depends not only on the amount of the factor but also on its ability to bring about this interaction, large multimers being more active. Ristocetin 112-122 von Willebrand factor Homo sapiens 46-49 2339348-2 1990 To precisely locate the domains on GPIb interacting with vWF and thrombin, we prepared several peptides that have amino acid sequences analogous to that of the GPIb alpha-chain and examined their effects on ristocetin-induced (vWF-dependent) and thrombin-induced platelet aggregations. Ristocetin 207-217 von Willebrand factor Homo sapiens 227-230 2154674-1 1990 Agglutination of human platelets by bovine von Willebrand factor (vWF) or by human vWF in the presence of ristocetin is inhibited by ADP and by several other platelet agonists but not by epinephrine. Ristocetin 106-116 von Willebrand factor Homo sapiens 83-86 33663351-8 2021 We detected elevated VWF antigen and decreased VWF ristocetin cofactor activity. Ristocetin 51-61 von Willebrand factor Homo sapiens 47-50 2104618-3 1990 Initial studies suggested that the modality of vWF interaction with GP Ib depended on the conditions used for induction of binding, either in the presence of ristocetin, or botrocetin, or with asialo-vWF. Ristocetin 158-168 von Willebrand factor Homo sapiens 47-50 2104618-7 1990 This led to the identification of a linear GP Ib alpha sequence (residues Ser251-Tyr279) that effectively inhibited platelet interaction with vWF mediated by ristocetin and, at higher concentration, also by botrocetin. Ristocetin 158-168 von Willebrand factor Homo sapiens 142-145 2242824-4 1990 The amount of ristocetin-induced normal vWF binding to nephrotic washed platelets, when ristocetin was used at concentrations of 0.5, 0.75, and 1.0 mg/ml, was 152-163% above the binding to normal platelets. Ristocetin 14-24 von Willebrand factor Homo sapiens 40-43 2242824-4 1990 The amount of ristocetin-induced normal vWF binding to nephrotic washed platelets, when ristocetin was used at concentrations of 0.5, 0.75, and 1.0 mg/ml, was 152-163% above the binding to normal platelets. Ristocetin 88-98 von Willebrand factor Homo sapiens 40-43 2242824-7 1990 These results appear to indicate that the plasma vWF level and the altered surface-negative charge in platelets both contribute to heightened vWF binding to GPIb, thus lowering the ristocetin concentration required for RIPA in SRNS. Ristocetin 181-191 von Willebrand factor Homo sapiens 49-52 2242824-7 1990 These results appear to indicate that the plasma vWF level and the altered surface-negative charge in platelets both contribute to heightened vWF binding to GPIb, thus lowering the ristocetin concentration required for RIPA in SRNS. Ristocetin 181-191 von Willebrand factor Homo sapiens 142-145 2300925-1 1990 The ability of von Willebrand factor protein (vWF) to agglutinate platelets with ristocetin depends upon the presence of its highest molecular weight multimers (HMWM) and its intact carbohydrate structure. Ristocetin 81-91 von Willebrand factor Homo sapiens 15-36 2300925-1 1990 The ability of von Willebrand factor protein (vWF) to agglutinate platelets with ristocetin depends upon the presence of its highest molecular weight multimers (HMWM) and its intact carbohydrate structure. Ristocetin 81-91 von Willebrand factor Homo sapiens 46-49 34497208-6 2021 Since ristocetin cofactor activity (vWF:RCo) and VWF antigen levels (vWF:Ag) are not routinely measured in clinical laboratories, the actual diagnosis is often determined by a mild prolongation of the activated partial thromboplastic time (APTT) associated with a relative decrease in factor VIII activity. Ristocetin 6-16 von Willebrand factor Homo sapiens 36-39 34741678-13 2021 Levels of VWF: Ag, VWF: activity, VWF: ristocetin, and factor VIII are increased in patients with COVID-19. Ristocetin 39-49 von Willebrand factor Homo sapiens 34-37 34269464-8 2021 Ristocetin cofactor assay quantified von Willebrand factor (vWF) activity. Ristocetin 0-10 von Willebrand factor Homo sapiens 37-58 34269464-8 2021 Ristocetin cofactor assay quantified von Willebrand factor (vWF) activity. Ristocetin 0-10 von Willebrand factor Homo sapiens 60-63 34089550-1 2021 BACKGROUND: Antibodies inhibiting von Willebrand factor (VWF) develop in a subset of patients with type 3 von Willebrand disease (VWD3) and may be detected by their inhibition of ristocetin cofactor activity (VWF:RCo). Ristocetin 179-189 von Willebrand factor Homo sapiens 34-55 34089550-1 2021 BACKGROUND: Antibodies inhibiting von Willebrand factor (VWF) develop in a subset of patients with type 3 von Willebrand disease (VWD3) and may be detected by their inhibition of ristocetin cofactor activity (VWF:RCo). Ristocetin 179-189 von Willebrand factor Homo sapiens 57-60 34089550-1 2021 BACKGROUND: Antibodies inhibiting von Willebrand factor (VWF) develop in a subset of patients with type 3 von Willebrand disease (VWD3) and may be detected by their inhibition of ristocetin cofactor activity (VWF:RCo). Ristocetin 179-189 von Willebrand factor Homo sapiens 209-212 34269797-8 2021 This report illustrates that continuous-infusion VWF concentrate administration with or without intravenous immunoglobulin rapidly achieves target ristocetin cofactor activity and provides adequate hemostasis in aVWD associated with immunoglobulin G MGUS. Ristocetin 147-157 von Willebrand factor Homo sapiens 49-52 35075935-9 2022 VWF antigen (VWF-Ag) and VWF ristocetin cofactor activity (VWF-Rico) on these topographic surfaces were quantified by enzyme-linked immunosorbent assay (ELISA), the loss of HMWM-VWF was quantified by immunoblotting. Ristocetin 29-39 von Willebrand factor Homo sapiens 59-62