Haemostasis
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An abnormal fibrinogen, denoted as 'fibrinogen Milano IV', has been found in a 36-year-old woman without any bleeding manifestations or thrombotic tendency. Routine coagulation studies revealed prolonged thrombin and reptilase clotting times, very low plasma fibrinogen concentration determined by the functional assay but a normal fibrinogen concentration measured by the immunologic assay. ⋯ The fibrinopeptide A peak of fibrinogen was preceded by an abnormal fibrinopeptide A*. Both peaks were collected for amino acid analysis which showed an exchange of arginine by histidine in position 16 of the A alpha chain of the fibrinopeptide A*.
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Case Reports
Failure of recombinant activated factor VII during surgery in a hemophiliac with high-titer factor VIII antibody.
Recombinant activated factor VII (rFVIIa) was used before and after inguinal hernioplasty to prevent bleeding in a patient with hemophilia A complicated by a high-potency antifactor VIII inhibitor. rFVIIa (75 micrograms/kg) was given before and after surgery, first by bolus infusions at intervals of 2-3 h for 47 h and then by continuous intravenous infusion at a rate of 38 micrograms/h for an additional period of 12 h. Although no undue bleeding was observed during and for the first 26 h after surgery, the patient subsequently developed wound bleeding and hematomas that necessitated blood transfusion and infusion of porcine factor VIII. This case indicates that rFVIIa is not always successful in patients with antifactor VIII inhibitor and that more experience is needed to establish the optimal doses at surgery.
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The neutralizing effect of protamine sulfate on enoxaparin-induced bleeding was compared in two rat models: one employing the gastric mucosa, and the other the tail skin, using a 2:1 ratio of protamine sulfate to enoxaparin on a weight basis. Whereas protamine sulfate reduced the median bleeding time (from 20 to 9.5 min) and blood loss (80%) in the gastric mucosa, and apparent 'all-or-none' response was seen in the tail skin, in agreement with a different hemostatic mechanism in the two bleeding models. In both models, protamine sulfate incompletely reversed the bleeding induced by enoxaparin.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Effectiveness and safety of the low-molecular-weight heparin CY 216 in the prevention of fatal pulmonary embolism and thromboembolic death in general surgery. A multicentre, double-blind, randomized, controlled clinical trial versus placebo (STEP). STEP Study Group.
Deep venous thrombosis is very frequent after general surgery, and its major complication, pulmonary embolism, is today the most frequent cause of postoperative death. The reduction of this cause of mortality is mainly based on its prevention rather than its therapy. This purpose was achieved by using physical and pharmacological means. ⋯ Eight (0.36%) belonged to the CY 216 group and 18 (0.80%) to the placebo group. In the CY 216 group, pulmonary embolism was the direct cause of death in 2 patients (0.09%), while the remaining 6 deaths could not be ascribed either directly or indirectly to thrombosis. In the placebo group, pulmonary embolism was the cause of death in 4 cases (0.18%; p less than 0.05) and contributed to death in 4.(ABSTRACT TRUNCATED AT 400 WORDS)
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Randomized Controlled Trial Clinical Trial
Aspirin at very ultra low dosage in healthy volunteers: effects on bleeding time, platelet aggregation and coagulation.
Aspirin at very ultra low dosage was tested in healthy volunteers (n = 20) in a randomized, double-blind and placebo-controlled trial. The results showed a bleeding time reduction (p less than 0.05) in volunteers having previously ingested aspirin. Platelet aggregation on platelet-rich plasma was not statistically modified after aspirin ingestion. Thrombin clotting time was always higher (p less than 0.05) in the treated group.