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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to carry out a multicenter study aimed at understanding the association of hemostatic factors with atherosclerotic vascular disorders for the Atherosclerosis Risk In Communities (ARIC) Study, we compared a blood collection and processing system developed in our laboratory with the state-of-the-art-procedures. The salient features of our system included the use of a new phlebotomy set for venipuncture, the use of Millipore filters for removing platelet residues in the plasma and the use of a mixture of anticoagulants and antiplatelet agents for inhibiting the in vitro activation of platelets, coagulation and fibrinolytic system. The results derived from systematic evaluations indicate that this newly developed system yields the lowest values of plasma beta TG, PF 4 and FPA when compared with the reported values. The technique also gave reliable values of representative hemostatic measurements such as fibrinogen, factor VII, factor VIII, von Willebrand factor, antithrombin-III, protein C, tissue-type plasminogen activator, and serum thromboxane B2. Further experiments revealed that the samples withstood temporary storage at -70 degrees C and overnight "shipping" manipulations without significant changes in the hemostatic values. We conclude that the described blood collection and processing system may be a valuable asset for conducting multicenter cooperative clinical trials and epidemiologic studies involving blood collection by multiple field centers or clinics.
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PMID:ARIC hemostasis study--I. Development of a blood collection and processing system suitable for multicenter hemostatic studies. 252 84

The effect of 20 mg tenoxicam once daily for 7 days on various components of the fibrinolytic system was studied in 10 healthy volunteers. Plasma plasminogen, antithrombin 3, and prekallikrein decreased significantly while plasma plasminogen activator inhibitor increased significantly. The medication did not affect fibrin plate lysis area or the plasma level of plasminogen activator, alpha-2-antiplasmin, alpha-2-macroglobulin, C1 inactivator or Factor XII. It is suggested that these changes may be caused by interference with hepatic enzyme systems. The reduction in plasma prekallikrein may indicate that tenoxicam exerts its anti-inflammatory effect by more than one mechanism.
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PMID:The fibrinolytic system during short-term treatment with tenoxicam. 280 72

In five patients with venous thromboembolic disease treated with recombinant tissue-type plasminogen activator (rt-PA), there was a marked increase in the mean concentrations of fibrinopeptide A (from 0.6 to 5.9 nM; P less than 0.0001) and desarginine fibrinopeptide B (from 5.6 nM to 24.1 nM; P less than 0.01) 30 min after a bolus of rt-PA (0.6 mg/kg). Thrombin was unlikely to be responsible because the levels of desarginine fibrinopeptide B exceeded those of fibrinopeptide A and the changes occurred despite concomitant heparin therapy. The purpose of this study therefore, was to determine whether rt-PA directly releases the fibrinopeptides from fibrinogen. Incubation of rt-PA with heparinized plasma or purified fibrinogen resulted in time and dose-dependent release of both fibrinopeptide A and B. Contaminating thrombin was not responsible for this activity by the following criteria: the rate of rt-PA mediated fibrinopeptide B release was considerably faster than that of fibrinopeptide A, and fibrinopeptide release was unaffected by heparin, hirudin, or a monospecific antithrombin IgG. Aprotinin also had no effect on fibrinopeptide release, indicating that this activity was not plasmin mediated. Fibrinopeptide release was shown to be due to rt-PA because this activity was completely blocked by a monoclonal antibody against the enzyme. Further, the specificity of rt-PA for the thrombin cleavage sites on fibrinogen was confirmed by the demonstration that rt-PA released fibrinopeptide A or fibrinopeptide B from fibrinopeptide A or B-containing substrates, respectively. These studies thus demonstrate that (a) rt-PA releases fibrinopeptides A and B from fibrinogen thereby indicating that this enzyme is not specific for plasminogen, and (b) plasma fibrinopeptide A and desarginine fibrinopeptide B levels are not specific markers of thrombin action on fibrinogen in patients receiving rt-PA.
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PMID:Human tissue-type plasminogen activator releases fibrinopeptides A and B from fibrinogen. 314 81

The effect of Norplant subdermal implants on 22 different hemostatic variables was determined in 100 women attending the Fertility Control Clinic of the Singapore National University Hospital before and after 6 and 12 months of use. The factors analyzed were: hematocrit, hemoglobin (Hb), prothrombin time (PT), activated partial thromboplastin time (APTT), platelet count, fibrinogen, coagulation factor II, Factor V,Factor VII, Factor VIII, Factor VIIIR:Ag, Factor X, plasminogen activator, FDP, plasminogen (imm), antithrombin III (functional), antithrombin (antigen), protein C, alpha2-antiplasmin, alpha2-macroglobulin, alpha2-antitrypsin, platelet count, platelet aggregation (ADP), and platelet aggregation (collagen). The factors that differed significantly after 12 months were: Hb,PT,APTT, Factors II,V,VII, and VIIIR:Ag, Plasminogen (imm), antithrombin III(antigen), alpha2-antiplasmin, platelet count, and platelet aggregation. Most of these differences, while significant, were still within the normal range, except for PT,APTT, and platelet count. The subjects were considered to be in an enhanced risk for hypercoagulation and thrombosis.
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PMID:The effects of Norplant-2 rods on clinical chemistry in Singaporean acceptors after 1 year of use: haemostatic changes. 314 69

Coagulation factor VIII, von Willebrand factor, antithrombin, fibrinogen, plasminogen activator capacity, and inhibitors of fibrinolysis, including a recently discovered fast inhibitor of tissue plasminogen activator, were measured three to six months after myocardial infarction in 116 male and 32 female patients aged less than 45 and in 136 age and sex matched random controls. Plasma concentrations of fibrinogen and the fast inhibitor of tissue plasminogen activator were raised in male patients (with or without correction for orosomucoid levels, blood group distribution, tobacco and alcohol consumption, and weight/height index) and plasminogen activator capacity was reduced. In female patients the concentrations of factor VIII, von Willebrand factor, the fast inhibitor of tissue plasminogen activator, alpha 2-antiplasmin, and C1 inhibitor were significantly increased. The increase in factor VIII concentrations depended strongly on a persisting inflammatory response. Multivariate analysis indicated that a combination of fibrinogen and tissue plasminogen activator inhibitor concentrations gave the best independent discrimination between male patients and controls. For female patients the best combination was von Willebrand factor and tissue plasminogen activator inhibitor. Male patients with multiple vessel atheromatosis at coronary angiography had higher fibrinogen concentrations than those with atheromatosis of a single vessel. Atheromatosis was defined as sharp-edged, plaque-like, or irregular indentations, often multiple, into the vessel lumen without features suggesting fibromuscular hyperplasia.
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PMID:Haemostatic function in myocardial infarction. 394 83

Selected coagulation and fibrinolytic factors were measured in plasma from 72 women taking oral contraceptives in a longitudinal study. Specific pills and sampling schedules were: Anovlar (3 mg norethisterone acetate and .05 mg ethinyl estradiol, combined), taken by 40 women sampled before, after 1 and 3 weeks, and 1 week of interruption; Sequens (.1 mg mestranol and 1.5 mg chlormadinone acetate sequential), 21 women, sampled before and after 2 and 3 weeks, and after 1 week of interruption; Ro 6-3129 (6-16-ethylthioretroprogesterone, 8-12 mg, continuously), 11 women, sampled after 1 month; additional samples were taken after 2, 3, 5, 7, 9 and 11 months. The pills containing estrogen affected the following parameters of the extrinsic coagulation system: thrombotest increased (p less than .001). Cold activition (20 hours at 0 degrees C.) of factor 7 was positive in 65% of subjects after pills, but 9% before. Estrogen pills decreased cephalin time (p less than .05), a screening test for the intrinsic coagulation system. Factors 8 (p less than .05), IX (p less than .02), and fibrinogen (p less than .001) increased. In the fibrinolytic system the estrogen pills increased plasminogen (p less than .001), proteolytic capacity (p less than .001) and streptokinase activated plasminogen activator (p less than .001). Among proteinase inhibitors, antiplasmin activity (p less than .01), antithrombin 3 (p less than .001) and C'i inactivator (p less than .001) decreased. Progestagen alone, or added in sequentials had no effect. Since the activation of clotting factors is probably more important than increases in concentration of 1 or more factors, the increased cold activition of factor 7 was considered indicative of increased clotting tendency.
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PMID:Studies on plasma coagulation and fibrinolysis during oral contraception of various types with special reference to cold activation of factor VII. 483 27

The effect of venous occlusion on blood fibrinolytic activity and platelet activation was studied in 10 normal human volunteers. The procedure was used as a model to study the pharmacological effects of 1-(4-isopropylthiophenyl)-2-n-octylaminopropanol (suloctidil, Sulocton) in a double-blind cross-over trial comparing suloctidil 200 mg three times per day versus identical placebo, each given for one week at random, after an initial one-week placebo run-in; blood sampling was done at the end of each period. Statistically significant changes in plasminogen, alpha 2-anti-plasmin, fibrinogen and antithrombin-III were consistently obtained on each occasion and could be ascribed to local haemoconcentration while a much higher increase of plasminogen activator activity occurred. The influence of venous occlusion on plasma beta-thromboglobulin and platelet factor-4 levels was found to be less consistent and under the trial conditions no obvious difference between the regimens studied could be objectified. On the contrary platelet aggregation by collagen was significantly reduced at the end of the suloctidil period.
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PMID:Activation of platelets and of fibrinolysis by venous occlusion in healthy volunteers and influence of suloctidil in comparison with placebo. 631 25

Forty-five patients with ischemic cerebrovascular disease (ICD) and 44 with deep venous thrombosis (DVT) and/or pulmonary embolism (PE) have been investigated in a non-active state of the disease with VIIIR:Ag, plasminogen activator before and after stasis, antiplasmin, antithrombin (activity, antigen, activity/antigen ratio) and spontaneous platelet aggregation. Control groups of 20 respectively 80 healthy females and males were used in the study. VIIR:Ag was elevated in the group with deep venous thromboembolic disease compared with the ICD group and a control group. VIIIR:Ag in the ICD group was elevated compared with the control group. Plasminogen activator determined before and after stasis was lowered in the two diseased groups. There was no statistically significant difference in any of the blood coagulation variables between patients on or off coumarol treatment. The patients on courmarol were, however, not reinvestigated when this medication had been withdrawn. Antithrombin levels below the reference interval of the control group of 80 blood donors were found in 11.4% of the patients with DVT/PE, whiel no patient in the ICD group had low antithrombin values.
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PMID:Blood coagulation studies in 45 patients with ischemic cerebrovascular disease and 44 patients with venous thromboembolic disease. 677 May 84

Of 154 Chinese patients who underwent gynecological operations, 4 showed a positive fibrinogen leg scan for venous thrombosis, an overall incidence of 2.6%. In those who were on (OC) oral contraceptives and had major pelvic surgery for benign conditions, the incidence was 10.5%; in those who had Wertheim hysterectomy for carcinoma for cervix, it was 6.7%. This confirms the rarity of postoperative thromboembolism in the Chinese. Fragment E showed a biphasic rise after major operation due to tissue injury and venous thrombosis. In patients with malignancy, the postoperative fibrinolytic shutdown, represented by decreased plasminogen activator together with increased alpha 1 antitrypsin and C inhibitor levels, was more marked. In addition alpha 2 macroglobulin level was lower and fell significantly after operation. In patients on OCs, fragment E levels were higher after surgery and there was no decrease in plasminogen activator levels. Antithrombin 3 levels did not fall except in 3 of the 4 patients with venous thrombosis. A marked increase in fragment E level and a decrease in antithrombin 3 level might be useful diagnostic markers for postoperative venous thrombosis.
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PMID:Deep vein thrombosis and changes in coagulation and fibrinolysis after gynaecological operations in Chinese: the effect of oral contraceptives and malignant disease. 743 38

Anabolic-androgenic steroid abuse has recently been linked with acute vascular events in athletes. To date, the relationship between steroid abuse and the potential for cardiovascular disease has been considered almost exclusively in terms of lipid metabolism. However, recent reports of thrombosis in androgen abusing athletes with no evidence of atherosclerosis suggests the hypothesis that thrombosis risk in such athletes could be mediated through androgen induced abnormalities of coagulation. To determine if anabolic-androgenic steroid abuse in weight lifters is associated with an activation of the hemostatic system we studied forty-nine weight lifters recruited through advertisements. History of androgen use or abstinence was confirmed via urine assays. Plasma was assayed for clotting and fibrinolytic activity by measuring thrombin/antithrombin complexes (TAT), prothrombin fragment 1 + 1 (F1 + 2), and D-dimers (D-di); markers of the endothelial based fibrinolytic components were assayed by measuring tissue plasminogen activator antigen (t-PA Ag) and its inhibitor (PAI-1); finally, the activity of antithrombin III, protein C, and protein S were measured. Abnormally high concentrations of TAT complexes were noted in 16% of our confirmed steroid using weight lifters compared to 6% of our confirmed nonusers (P = .01). Steroid users also demonstrated abnormally high concentrations of F1 + 2 and D-dimers when compared to nonusers (44 vs. 24%, P < .001, and 9 vs. 0%, respectively). Non-steroid users were more likely to have elevated levels of t-PA Ag and PAI-1 than our steroid using weight lifters (both P < .001). The activities of antithrombin III and protein S were more likely to be higher in users compared to nonusers (22 vs. 6%, P = .005; 19 vs. 0%, respectively). Some anabolic-androgenic steroid using weight lifters have an accelerated activation of their hemostatic system as evidence by increased generation of both thrombin and plasmin. These changes could reflect a thrombotic diatheses that may contribute to vascular occlusion reported in young athletes using these drugs. The predictive value of these coagulation abnormalities in terms of risk of thrombosis to individual steroid using weight lifters or the population as a whole remains to be studied.
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PMID:Anabolic-androgenic steroid abuse in weight lifters: evidence for activation of the hemostatic system. 763 72


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