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At least 19 recordsLinked to original sources
PubMed1985

Effect of Bordetella pertussis vaccine on bleeding time, whole blood coagulation time and platelet aggregation in animals.

Bordetella pertussis vaccine, a hypoglycemic agent significantly prolonged the bleeding time and whole blood coaguistion time in rabbits and dogs when administered intraperitonially. The vaccine also affects platelet aggregation in rats 4 days after its intraperitonial administration. The effect on platelet aggregation is thought to be due to its beta adrenargic receptor blocking action which may also contribute to the hypoglycemia.

Animals↗
PubMed1978

Phenprocoumon requirement, whole blood coagulation time, bleeding time and plasma gamma-GT in patients receiving mianserin.

A possible interaction between the tetracyclic antidepressant mianserin and a coumarin derivative has been investigated. Sixty-three subjects, 61 of whom required anticoagulant therapy for a variety of medical conditions, were treated for 5 consecutive weeks with phenprocoumon, in a dose adjusted to reduce the prothrombin time to 15%-25%. After an initial control period of one week, subjects were randomly treated under double-blind conditions with mianserin 3 X 10 mg daily or 3 X 20 mg daily, or with a matching placebo. The dose of mianserin was gradually increased to reach the maximum by the 6th day. Three subjects dropped out and 60 completed the trial. The dose of phenprocoumon and the prothrombin, bleeding, and coagulation times were not significantly affected by administration of mianserin. It can be concluded that there is no clinically important interaction between phenprocoumon and doses of mianserin effective in depression. Sedation was more frequent in patients taking mianserin than in those given placebo.

4-Hydroxycoumarins↗
PubMed1976

Progress report: the activated coagulation time of whole blood (ACT).

The activated coagulation time of whole blood (ACT) has, in the nearly ten years since its first description in the literature, proven itself one of the best laboratory tests for the control of heparin therapy, both for patients undergoing treatment for thromboembolic disease and for those on extracorporeal circulation. It is simple, largely free from subjective variation, precise, and quick. Prolongation of the ACT in the heparinized individual is directly proportional to the concentration of heparin in the blood, and the test accurately reflects the semilogarithmic disappearance of the anticoagulant effect in most patients. In addition, the test serves well as a bedside screening test for deficiencies of the intrinsic coagulation mechanism. The author summarizes the sutdies that have been carried out on this technic since its original description, and briefly presents three protocols for heparinization of patients who have thromboembolic disease.

Blood Coagulation Disorders↗
PubMed1994

Comparison of activated coagulation time and whole blood heparin measurements with laboratory plasma anti-Xa heparin concentration in patients having cardiac operations.

Previous reports suggest that activated clotting times do not correlate with heparin concentration during cardiopulmonary bypass. This study was designed to compare whole blood heparin concentration and activated clotting time measurements with laboratory-based plasma heparin concentration. Sixty-two patients having cardiac operations requiring cardiopulmonary bypass were enrolled in this study. The study was conducted in two phases. In phase I of this trial, blood specimens were obtained from 30 patients before heparin administration and after each of three heparin doses (20, 80, and 150 U/kg). In phase II, blood specimens were obtained from 32 patients before heparin administration and 10 minutes after each of the following: heparin administration (250 or 300 U/kg), initiation of cardiopulmonary bypass, achievement of hypothermia, initiation of rewarming, and immediately before discontinuation of bypass. Blood specimens were used to measure activated clotting time (kaolin and celite), whole blood heparin concentration, and anti-factor Xa plasma heparin concentration. In phase I, activated clotting time (celite: r = 0.91; kaolin: r = 0.93) and whole blood heparin concentration (r = 0.98) measurements correlated well with plasma heparin concentration. After initiation of cardiopulmonary bypass (phase II), weak correlations for activated clotting time measurements (celite: r = 0.34; kaolin: r = 0.59) and a strong correlation for whole blood heparin concentration (r = 0.95) were evident when compared with plasma heparin concentration. During bypass, activated clotting time measurements also inversely correlated with temperature (celite: r = -0.21; kaolin: r = -0.19) and hematocrit (celite: r = -0.26; kaolin: r = -0.21). A weak correlation between activated clotting time measurements and plasma heparin concentration is evident during the cardiopulmonary bypass period, probably because of the influence of both reduced hematocrit and temperature on the activated clotting time assay. In contrast, whole blood heparin measurements correlate well with plasma heparin concentration before and during bypass. Further studies are needed to determine whether maintaining heparin levels during cardiopulmonary bypass by monitoring heparin concentration is more effective in preventing consumptive activation of the hemostatic system, reducing bleeding, and minimizing the use of blood products after cardiopulmonary bypass when compared with a protocol based on activated clotting time.

Blood Coagulation↗
PubMed1986

Lack of efficacy of dried garlic in patients with hyperlipoproteinemia.

The effects of dried garlic on blood lipids, apolipoproteins and blood coagulation parameters in hyperlipemic patients were studies in two controlled, randomized, double-blind studies. Both studies comprised placebo and therapy periods of 6 weeks each. The doses administered were 3 X 198 mg in Study I (34 patients) and 3 X 450 mg in Study II (51 patients). In both studies, the following serum parameters were measured every 3 weeks: total cholesterol, HDL (high density lipoprotein)- and LDL (low density lipoprotein)-cholesterol, triglycerides and several safety parameters. In addition, apolipoproteins A and B, euglobulin lysis time, fibrin split products, prothrombin time, whole blood coagulation time and fibrinogen levels were determined in the second study only. The results indicated that neither dosage of dried garlic showed any significant effect on any of the parameters measured. It is therefore concluded that, if there is any effect of garlic on the parameters measured, it is not apparent when using a dried preparation in the dosage studied.

Apoproteins↗
PubMed1981

Measurement of fibrinopeptide A in the evaluation of heparin activity and fibrin formation during hemodialysis.

In order to monitor heparin activity during hemodialysis, were evaluated three commonly used methods; measurement of whole blood activated coagulation time (WBACT), whole blood thrombin time (WBTT) and heparin concentration in plasma, determined with a chromogenic substrate. Studies were performed on six regular dialysis patients during 4-hour dialysis sessions, employing three different heparin regimens; a single intravenous loading dose only, priming of the dialyzer with heparin followed by a heparin infusion and a pharmaco-kinetic model. Efficacy of heparinization was assessed by determination of fibrinopeptide A (FPA) which is a peptide split product of the fibrinogen molecule formed during thrombin-induced conversion to fibrin. There was a linear correlation (r = 0.95) between FPA-production in the dialyzer and the FPA content of the blood at the inlet to the dialyzer; the slope of the correlation line indicates that at least 65% of FPA formed in the dialyzer is disposed during passage through the patient. Considerably higher production of FPA was noted when the heparin concentration was below 0.5 IU/ml than at a higher level. This was a common finding at the end of a dialysis, regardless of regimen. No consumption of antithrombin (AT III) occurred during a dialysis with any of the heparin regimens. Good correlations were found between WBACT, WBTT and heparin concentration. Heparin activity during a dialysis may be monitored with any of these three methods with equal reliability. However, from a practical point of view, WBACT appears most attractive because of its simplicity. FPA generation, frequency of visible clots in the dialyzer and hemorrhagic manifestations were essentially the same for each of the heparin dose regimens. The simple administration of a single loading dose was as safe as the more complicated infusion technique.

Female↗
PubMed1983

Whole-blood activated coagulation time for evaluation of heparin activity during hemodialysis: a comparison of administration by single-dose and by infusion.

Whole-blood activated coagulation time (WBACT), measured by an automated technique, was used to estimate heparin activity in 12 patients in a chronic hemodialysis program. Identical heparin doses, calculated on a body-weight basis, were given to each patient, either as a single dose before a 3.5-4 hour dialysis, or as a loading dose followed by infusion during the first 1.5-2 hours of dialysis. Each dose regimen was repeated during four consecutive dialyses. The variation in heparin activity between the four dialyses did not exceed the standard deviation of the WBACT method. This indicates that the heparin requirement between dialyses was steady. Appreciable interindividual differences in heparin activity were found, however, showing that heparin requirement cannot be determined solely on a body-weight basis. Fibrin deposits in the venous drip chamber were uncommon during the first two hours but became more frequent towards the end of dialysis, the increase being significantly more with the single-dose than with the infusion regimen. Maintenance of heparin activity at the end of dialysis was better with the infusion regimen. Prolonged heparin infusion is preferable to single-dose injection to maintain the heparin effect and prevent fibrin deposits.

Adult↗
PubMed2004

Functional characterization of recombinant batroxobin, a snake venom thrombin-like enzyme, expressed from Pichia pastoris.

A thrombin-like enzyme of Bothrops atrox moojeni venom, batroxobin, specifically cleaves fibrinogen alpha chain, resulting in the formation of non-crosslinked fibrin clots. The cDNA encoding batroxobin was cloned, expressed in Pichia pastoris and the molecular function of purified recombinant protein was also characterized. The recombinant batroxobin had an apparent molecular weight of 33 kDa by SDS-PAGE analysis and biochemical activities similar to those of native batroxobin. The purified recombinant protein strongly converted fibrinogen into fibrin clot in vitro, and shortened bleeding time and whole blood coagulation time in vivo. However, it did not make any considerable alterations on other blood coagulation factors. Several lines of experimental evidence in this study suggest that the recombinant batroxobin is a potent pro-coagulant agent.

Amino Acid Sequence↗
PubMed1971

The activated coagulation time of whole blood as a routine pre-operative sceening test.

Patients with disorders of hemostasis who undergo surgical procedures are in danger of hemorrhage. While the careful medical history remains the most sensitive test of a bleeding tendency, some such patients can give no suggestive history. In three patients with coagulopathy-one with mild classical hemophilia, one with Christmas disease, and one with warfarin toxicity-the abnormality was missed by routine preoperative history but promptly detected by the routine preoperative use of the activated coagulation time (act). Either this test or the activated partial thromboplastin time should be included in the routine preoperative work-up, along with appropriate additional tests of the hemostatic mechanism.

Adult↗