Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.69 (APC)
 16,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Veno occlusive disease (VOD) is a frequent complication of allogenic bone marrow transplantation (BMT) for which no predictive blood markers are available. 39 patients grafted for severe aplastic anemia (18), and leukemia (21) were prospectively studied. Of the 39 patients, 5 leukemic patients, but no aplastic patients developed VOD. In all the 5 patients with VOD complications we demonstrated a decrease in factor VII and in protein C before the clinical onset of the disease and before any changes in hepatic enzymes were observed. This decrease is the earliest sign of hepatic involvement by the VOD suggesting that the determination of Factor VII and protein C can be used as a prediction test to identify the patients who are at risk of developing VOD after transplantation. In addition, a toxicity of the endothelial cells was suggested by the observed increase in von Willebrand factor and in Serum Angiotensin Converting Enzyme. Signs of endothelial toxicity was more pronounced in leukemic than in aplastic patients.
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PMID:Liver veno-occlusive disease after bone marrow transplantation changes in coagulation parameters and endothelial markers. 132 36

An increased incidence of fistula thrombosis has been reported in haemodialysis patients treated with recombinant human erythropoietin (rHuEpo). The present study sought to investigate this problem by measuring fistula blood flow, blood viscosity, and a variety of tests of coagulation and haemostasis in a group of ten haemodialysis patients treated with rHuEpo. Fistula blood flow did not alter during the first 12 months of rHuEpo despite a significant increase in whole-blood viscosity. Bleeding time improved in all ten patients after 4 months of therapy, and this improvement was maintained at 12 months. There were no significant changes in one-stage prothrombin time, kaolin cephalin clotting time, whole-blood clotting time, prothrombin consumption index, plasma fibrinogen factor VII, factor VIII, antithrombin III, or platelet aggregability to ADP over the first 4 months of rHuEpo. In contrast, protein C decreased from 84.3 to 66.4% (P less than 0.01) and protein S from 124.1 to 68.3% (P less than 0.001) over the first 4 months. By 8 and 12 months, the concentrations of these substances had returned to pretreatment values. The levels of protein C and S attained at 4 months are known to predispose to thrombosis, and it is possible that this effect may contribute to the increased incidence of fistula thrombosis observed in haemodialysis patients treated with rHuEpo.
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PMID:Coagulation studies and fistula blood flow during erythropoietin therapy in haemodialysis patients. 132 49

Laboratory diagnosis of protein C deficiency is complicated by the fact that many patients referred for investigation are already being treated with oral anticoagulants. Protein C and factor VII have similar half lives and by using the protein C:factor VII ratio we hoped to be able to detect protein C deficiency in patients receiving oral anticoagulants. We have studied activity levels of protein C and factor VII to produce protein C:factor VII activity ratios in 105 patients receiving oral anticoagulants, 42 normal subjects, and nine patients with known inherited protein C deficiency. The mean ratios for these groups were 1.38, 1.12 and 0.63 respectively. In patients receiving oral anticoagulants, the protein C level showed a poor correlation with the international normalized ratio (INR) value. Reference ranges for protein C at different levels of anticoagulation were therefore considered unsuitable for the identification of inherited protein C deficiency. Five patients with inherited protein C deficiency were studied with and without oral anticoagulation; their protein C:factor VII ratios remained relatively unchanged, despite alterations in the level of the individual proteins. These results suggest that measurement of the protein C:factor VII ratio may help to identify patients with inherited protein C deficiency whilst on oral anticoagulants.
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PMID:Detection of protein C deficiency during oral anticoagulant therapy--use of the protein C:factor VII ratio. 193 26

In our previous paper, we reported the development of a blood collection and processing system (BCPS) suitable for the ARIC multicenter hemostasis study. As an additional step of preparation for the ARIC study, we incorporated this BCPS into an organizational plan to increase efficiency and minimize errors. We initially designed organizational trays for blood collection tubes and aliquot tubes and developed a coordinated step-by-step plan for the orderly processing of blood samples. Once the plan was considered workable, we carried out a pilot study to test the feasibility of this integrated organizational plan. Included in the pilot study were 95 healthy subjects randomly selected from 4 ARIC field centers, whose age and gender were comparable to those projected for the ARIC population. We determined the time lapse of filling the first tube as an index of blood flow. The overall mean time-lapse was 23 s (S.D. = 5). There was no significant difference among the field centers. We also determined the entire time lapse required for completing the sample processing. The total processing time was always less than 60 min. By performing the processing of samples in pairs, all the samples from two subjects could be completely processed in 70 min. This greatly increased the efficiency of field center operation. We evaluated the potential in vitro hemostasis activation by measuring plasma beta-thromboglobulin and platelet factor 4 levels. The geometric means of both proteins were comparable to our previously reported results. Fibrinogen, factor VII, factor VIII, von Willebrand factor, antithrombin III, protein C and activated partial thromboplastin time were analyzed.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:ARIC hemostasis study--II. Organizational plan and feasibility study. 208 37

Mortality rates of coronary heart disease are much lower in Japan than in the United States. The authors' previous report on coagulation factors showed that population levels of plasma fibrinogen and factor VII activity parallel this mortality difference. To investigate other hemostatic variables, the authors assessed indicators of fibrinolytic activity (tissue plasminogen activator antigen) and coagulation inhibition (antithrombin III activity and protein C) in 136 men aged 34-55 years in four different samples: rural Japanese, urban Japanese, Japanese Americans, and Caucasian Americans. Mean tissue plasminogen activator antigen was higher in Caucasians and Japanese Americans than in rural and urban Japanese (p less than 0.01), while a contrasting trend in mean antithrombin III activity was suggested (p = 0.10). No significant differences were observed in mean levels of protein C. After controlling for known coronary risk factors, mean levels of tissue plasminogen activator antigen remained significantly different across the four samples (p less than 0.01); mean antithrombin III activity was not different (p = 0.23). Population differences in tissue plasminogen activator antigen parallel the coronary heart disease mortality difference between Japan and the United States. Although no definite evidence is available showing that tissue plasminogen activator antigen is a risk factor for coronary heart disease, the present study suggests a positive ecologic association between this hemostatic factor and coronary heart disease mortality.
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PMID:Hemostatic variables in Japanese and Caucasian men. Tissue plasminogen activator, antithrombin III, and protein C and their relations to coronary risk factors. 211 52

Hereditary combined deficiency of vitamin K-dependent factors is a rare entity. We report a 7-year-old girl of Arab origin with hereditary deficiency of the procoagulants factors II, VII, IX and X and the natural anticoagulants proteins C and S. The patient is the tenth offspring of a consanguinous marriage and presented at 6 weeks with spontaneous intracerebral haemorrhage. Symptoms improved following plasma infusion. A sibling died at 5 d from uncontrollable umbilical bleeding. Blood coagulation work-up at 6 years showed: factor II:C (activity) 12 U/dl, factor II:Ag (antigen) 40 U/dl; factor VII:C 12 U/dl; factor IX:C 36 U/dl, factor IX:Ag 57 U/dl; factor X:C 17 U/dl, factor X:Ag 54 U/dl; protein C activity 43 U/dl; protein C:Ag 45 U/dl; protein S:Ag 34 U/dl; levels of factors V:C and VIII:C were normal. Assays of coagulation factors in the parents and five of the siblings were within the normal range. Following acute infection and dilantin therapy procoagulant activity levels were reduced further and were partially increased after vitamin K infusion. Crossed immunoelectrophoresis of prothrombin in the presence of calcium lactate revealed a population of des-carboxyprothrombin. Serum vitamin K epoxide levels were undetectable. The data suggest that the defect in our patient stems from abnormal carboxylation of the vitamin K-dependent proteins and that the mode of inheritance is autosomal recessive.
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PMID:Hereditary deficiency of all vitamin K-dependent procoagulants and anticoagulants. 214 29

The influence of coffee and caffeine consumption on hemostatic factors was studied in 2 randomized trials. Both studies were conducted in young, healthy adults. In the first study, 107 participants were randomly allocated to one or 3 intervention groups, drinking filtered coffee, boiled coffee or no coffee at all, respectively, for a period of 9 weeks. In the second study, 69 subjects received either 4-6 tablets containing 75 mg caffeine or the same amount of placebo tablets, while using decaffeinated coffee. In this double-blind study caffeine intake from any other source was not allowed. Blood samples for hemostatic factors were obtained at baseline and after 9 weeks of intervention. The findings indicate no effect of coffee consumption on fibrinogen, clotting factor VII activity, factor VIII antigen, protein C and protein S and also no effect of caffeine consumption on fibrinogen and factor VII activity.
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PMID:Coffee, caffeine and hemostasis: results from two randomized studies. 214 67

We describe herein a procedure for the purification of protein C, protein S, prothrombin, factor VII, and factor X to apparent homogeneity from rabbit plasma. The initial steps, which are common to the purification of vitamin K-dependent proteins from other mammalian species, include adsorption onto and elution from barium followed by anion exchange chromatography. Proteins were further purified using a variety of techniques, including affinity chromatography, gel filtration, and anion exchange chromatography in a Fast Protein Liquid Chromatography system. Significant structural homologies exist between rabbit, human, and bovine vitamin K-dependent proteins. As is true for protein C and factor X in human and bovine plasma, rabbit protein C and factor X are two-chain proteins which can be converted to active proteases by specific venom activators. Rabbit factor VII is also a two-chain protein and can restore coagulant activity to human or bovine plasma deficient in factor VII. In contrast, rabbit protein S and prothrombin are single chain proteins. In view of the well-described species specificity of many of the vitamin K-dependent proteins, purified rabbit coagulant and anticoagulant proteins should be useful in the development of animal models of coagulation and/or thrombosis.
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PMID:Purification and preliminary characterization of rabbit vitamin K-dependent coagulation proteins. 215 Apr 52

The effects of parenterally given polyestradiol phosphate (80 or 160 mg i.m. monthly) and bilateral subcapsular orchiectomy on blood coagulation and fibrinolytic parameters were compared in 11 patients with prostatic carcinoma. Estrogen therapy lowered antithrombin III, plasminogen and plasminogen activator inhibitor activities, whereas these parameters remained unchanged in orchiectomized patients. There were no significant changes in platelet count, fibrinogen, factor VII, protein C and alpha 2-antiplasmin in either group. Estrogen had unfavorable effects on hemostatic laboratory parameters in the direction of a hypercoagulable state. However, no thromboembolic complications were encountered.
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PMID:The effect of parenteral estrogen versus orchiectomy on blood coagulation and fibrinolysis in prostatic cancer patients. 217 41

To identify changes in haemostatic balance during continuous oestradiol-progestogen treatment, 60 postmenopausal women with climacteric complaints, mean age 55.4 years (range 44-68) were randomly allocated to receive one of four hormone replacement regimens for one year. All four formulations were administered daily and continuously, each contained 2 mg of 17 beta-oestradiol in combination with either norethisterone acetate, 1 mg (group A) or 0.5 mg (group B) or megestrol acetate, 5 mg (group C) or 2.5 mg (group D). No significant changes occurred during treatment within or between the groups in platelet count, fibrinogen and 2-antiplasmin. Activated partial thromboplastin time was shortened (P less than 0.05) in group D and a decline in factor VII activity and antigen (P less than 0.001) and in ATIII activity (P less than 0.05) was noted in group A. Protein C tended to decline in all treatment groups but statistically significant changes were noted only in groups A and C. Two women developed crural thrombosis during the observation period.
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PMID:Haemostatic changes during continuous oestradiol-progestogen treatment of postmenopausal women. 222 87


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