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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hemorrhage was prospectively identified in 26 of 116 consecutive patients (23%) who were receiving intracoronary streptokinase for occlusive coronary thrombi producing infarction. Bleeding was not influenced by the dose of streptokinase or the method of cardiac catheterization. Before treatment, prothrombin time and partial thromboplastin time were normal in both bleeders and nonbleeders. Fibrinogen levels measured by bioassay after streptokinase (mean +/- SEM) were 62 +/- 29 mg/dl in patients with major bleeding, 111 +/- 26 mg/dl in patients with minor bleeding, and 109 +/- 13 mg/dl in nonbleeders (p = NS). The regression slope b calculated from poststreptokinase fibrinogen time-concentration data in 71 patients was 4.7 mg/dl/hr. However, mean fibrinogen concentrations calculated at sequential 5 hr intervals revealed no net regeneration for the first 20 hr after thrombolysis. The apparent fibrinogen regeneration rate was less than normal (31 mg/kg/day) for more than 10 hr but subsequently increased to 94 +/- 10 mg/kg/day by the second day. The initial apparent latency of fibrinogen regeneration paralleled the sharp rise in fibrinogen degradation products, which began to decline after 20 hr of treatment but remained elevated well into the second day. Because of their anticoagulant effects, these products may interfere with the fibrinogen assay, causing spuriously low results. Thus, whether the early delay in fibrinogen regeneration is real or simply a reflection of the effects of fibrinogen degradation products on the bioassay, it signals the time for caution in initiating systemic heparin therapy.
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PMID:Hemorrhage and the products of fibrinogen digestion after intracoronary administration of streptokinase. 671 16

To elucidate the relationship between estrogen and thrombosis, we studied blood coagulation parameters in women whose ovaries were stimulated with human menopausal gonadotropins (hMG). Daily hMG administration over 1 to 2 weeks in seven anovulatory women increased plasma 17 beta-estradiol levels fivefold over the pretreatment value. Of the coagulation parameters, the fibrinogen level increased significantly from an initial value of 248 +/- 11.7 mg/dl (mean +/- SEM) to 353 +/- 32.2 mg/dl after hMG treatment (P less than 0.05), with a significant positive correlation between estrogen and fibrinogen levels (r = +0.762). In addition, a thrombokinetics study showed that the maximal rate of change in optical density of the prothrombin time and activated partial thromboplastin time was significantly increased, suggesting that the coagulation factors involved in extrinsic, intrinsic, and common pathways could be increased by estrogen. Antithrombin III levels decreased gradually during hMG administration. Thus, increased endogenous estrogen levels appear to induce the so-called "hypercoagulable state" through both an increase in coagulation factors in the coagulation cascade system and a decrease in antithrombin III, a potent natural inhibitor of activated coagulation factors. Patients on a regimen of hMG treatment for induction of ovulation serve as excellent models for the study of alteration of "natural" estrogen-mediated coagulation parameters.
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PMID:Response of blood coagulation parameters to elevated endogenous 17 beta-estradiol levels induced by human menopausal gonadotropins. 678 79

Following 70% hepatectomy on rats the galactose elimination capacity, taken as a measure of the cytosolic liver function, was reduced from 2.55 +/- 0.48 to 1.27 +/- 0.19 (mean +/- SEM) mumol/min. Six hours later it was restored to control values. The prothrombin index, representing the function of the endoplasmic reticulum, was reduced from 1.13 +/- 0.02 to 0.34 +/- 0.02 (arbitrary units) after 12 h, and it was restored after 96 h. The rapid normalization of the initial fall in the capacity to metabolize galactose reflects a two- to three-fold increase of the galactose metabolizing capacity of the remaining liver. This study demonstrates that liver functions are dissociated in time following 70% hepatectomy in the rat, and that the galactose elimination capacity is restored before regeneration can compensate for the loss in liver cell mass.
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PMID:Quantitative liver functions after 70% hepatectomy. 680 Aug 22

The effects of sequential prostacyclin infusions at 2, 4, and 8 ng/kg/min for 1 hr were determined in six patients with chronic renal failure. Diastolic blood pressure decreased in a dose-dependent fashion from 74 +/- 4 mm Hg (mean +/- SEM) to 70 +/- 4, 66 +/- 5, and 55 +/- 5 during the 2, 4, and 8 ng/kg/min infusions, respectively; systolic blood pressure was not affected by prostacyclin. The fall in diastolic blood pressure was associated with a progressive rise in heart rate from 77 +/- 3 to 91 +/- 4 bpm and lowering of body temperature from 36.7 +/- 0.1 to 36 +/- 0.2 degrees. The threshold concentration of adenosine diphosphate that evoked reversible and irreversible platelet aggregation increased progressively from 1.2 to 2.8 and from 2.8 to 6 microM, respectively, during the prostacyclin infusions. Prostacyclin infusions had no effect on prothrombin time, activated partial thromboplastin time, or platelet count, but template bleeding time increased (not statistically significantly) from 5.8 to 12.3 min. In three of six patients, the 8 ng/kg/min infusion was terminated prematurely due to nausea, vomiting, and/or hypotension. We conclude that platelet aggregability can be inhibited in patients with chronic uremia by infusing 4 ng/kg/min prostacyclin without causing untoward side effects. When infused at hemodynamically tolerable doses, prostacyclin might serve as an in vivo inhibitor of platelet aggregation during hemodialysis or cardiopulmonary bypass.
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PMID:Effects of prostacyclin infusion in uremic patients: hematologic and hemodynamic responses. 701 91

To investigate pituitary effects on the vitamin K-dependent coagulation factors, female rats were hypophysectomized (hypox) and treated with growth hormone (GH), cortisone, thyroxine, vitamin K, or saline. After 11 days of treatment, the prothrombin time, platelet count, and factors II, VII, IX, and X were determined. The prothrombin time was 52.9 +/- 1.2% for control rats and 39.1 +/- 0.8% for hypox rats (mean +/- SEM; p < 0.001). All factors decreased after hypophysectomy, reaching significance for factor VII (from 264 +/- 23% to 131 +/- 9%; p < 0.001) and factor IX (from 28.4 +/- 2.2% to 17.1 +/- 2.5%; p < 0.01) while the platelet count was unaffected. When hypox rats were treated with GH, the prothrombin time increased to 50.9 +/- 1.0% (p < 0.001) and factor VII to 299 +/- 10% (p < 0.001). Factor II, IX, and X were slightly increased after GH substitution but not after cortisone, thyroxine, or vitamin K treatment. To summarize, GH is of importance for normal hemostasis in the female rat.
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PMID:Growth hormone deficiency impairs blood clotting and reduces factor VII coagulant activity in rat. 749 70

Activation of prothrombin and the subsequent reactions of thrombin with its substrates and its major inhibitors, antithrombin III (AT III) and heparin cofactor II (HC II), likely reflect both intravascular and extravascular coagulation. Several studies have reported increased in vivo coagulation in cancer. Whether the increased thrombin production in malignancy is accompanied by a corresponding increase in thrombin inhibition is unknown. This study quantified prothrombin fragment 1 + 2 (F1 + 2), thrombin-AT III (TAT), thrombin-AT III-vitronectin (TAT.V), and thrombin-HC II-vitronectin (THCII.V) in the plasmas of healthy volunteers (n = 37); patients with localized solid tumours before treatment was initiated (n = 39); and five patients with non-Hodgkin's lymphoma, both before and during weekly chemotherapy. Two of the five non-Hodgkin's lymphoma patients developed deep venous thrombosis (DVT) during chemotherapy. In normal plasma, where the concentrations of the four parameters likely reflect haemostasis, the sum of TAT, TAT.V and THCII.V was 61% that of F1 + 2, compared with 30% in cancer plasmas. In addition, the mean +/- SEM of F1 + 2 in the plasmas of cancer patients (1.56 +/- 0.09 nM) was significantly elevated (P < 0.001) when compared with healthy volunteers (0.89 +/- 0.06 nM). Eight weeks of chemotherapy increased the F1 + 2 and the binary TAT in plasmas of the non-Hodgkin's lymphoma patients by approximately 1.5- and 2.9-fold, respectively. Thus, increased prothrombin activation in cancer patients, without corresponding increases in concentrations of thrombin-inhibitor complexes, raise the possibility that a significant portion of the thrombin generated in vivo escapes inhibition in cancer and contributes to the high risk of DVT in malignancy.
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PMID:The hypercoagulable state in cancer patients: evidence for impaired thrombin inhibitions. 751 51

Gastric mucosal bleeding time was measured prospectively in 25 patients with cirrhosis and portal hypertension undergoing routine sclerotherapy. Age and sex-matched controls without liver disease were also studied. Correlations were sought between gastric mucosal bleeding time and age, platelet count, prothrombin time, skin bleeding time, Child-Pugh score, variceal size before sclerotherapy, and degree of portal hypertensive gastropathy. Gastric bleeding time was prolonged in 12% of the patients with cirrhosis (mean, 3.24 minutes; SEM, 0.476) and in none of the controls (mean, 3.0; SEM, 0.171). No correlation was noted between gastric bleeding time and any of the above variables. The results of this study indicate that gastric mucosal bleeding time is prolonged in cirrhosis but is an independent physiologic parameter unrelated to any of the above-mentioned variables.
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PMID:Gastric mucosal bleeding time in cirrhosis. 798 26

Endothelial release of tissue plasminogen activator (t-PA) may initiate fibrinolysis. Fibrinolysis and coagulation were investigated in 12 patients undergoing elective coronary artery bypass surgery. Cardiopulmonary bypass (CPB) was 108 +/- 7 min (mean +/- SEM), the time of cold, crystalloid, retrograde cardioplegia 53 +/- 5 min. Arterial and coronary sinus blood were sampled concomitantly before cardioplegia and after release of the aortic cross-clamp, for measurement of t-PA antigen (Ag) and activity, plasminogen activator inhibitor (PAI-1) Ag and activity, t-PA/PAI-1 complex, single chain urokinase (sc-uPA) and urokinase (uPA) plasminogen activators, the fibrin split product D-dimer, thrombin-antithrombin complex (TAT), and the prothrombin split product F 1 + 2. Cardiopulmonary bypass significantly increased t-PA Ag and activity, t-PA/PAI complex, D-dimer, TAT, and F 1 + 2, and decreased PAI-1 Ag and activity in arterial blood; uPA and sc-uPA were unchanged. The tissue plasminogen activator antigen was higher in coronary sinus than arterial blood after 1 (39 +/- 5 vs 24 +/- 4 ng/ml, P < 0.003), 4 (P < 0.003), and 10 min (P < 0.004) reperfusion. Tissue plasminogen activator activity and t-PA/PAI complex increased, PAI-1 activity decreased, while all other parameters were unchanged across the coronary circulation. In conclusion, CPB induces fibrinolysis and coagulation. Cold cardioplegia induces t-PA release in the coronary circulation, denoting a postischemic antithrombotic function of the coronary endothelium. Tissue plasminogen activator may be used to evaluate endothelial stimulation or injury induced by CPB, or by different regimens of myocardial protection.
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PMID:Fibrinolysis during cardiac surgery. Release of tissue plasminogen activator in arterial and coronary sinus blood. 808 78

In patients with cirrhosis and ascites decreased renal blood flow might be related to the severity of liver disease but the relationship between the severity of cirrhosis and renal perfusion has not yet been established. Thus we measured renal, systemic and splanchnic hemodynamics in 63 patients with ascites and in 28 without ascites. When compared to patients without ascites, patients with ascites had lower renal blood flow (1,170 +/- 100 vs. 935 +/- 55 ml/min/1.73 m2; mean +/- SEM, p < 0.05) and renal perfusion pressure (78 +/- 2 vs. 72 +/- 1 mm Hg, p < 0.05 and higher inferior vena cava pressure (6.5 +/- 0.7 vs. 10.7 +/- 0.7 mm Hg, p < 0.05). Patients with ascites had significantly higher serum bilirubin concentrations, hepatic venous pressure gradient and lower serum albumin concentrations, indocyanine green (ICG) extraction than patients without ascites. Renal vascular resistance, glomerular filtration rate, mean arterial pressure, cardiac index and systemic vascular resistance were not significantly different between the two groups. By multiple regression analysis no significant correlation was found between liver tests (i.e., prothrombin time, serum bilirubin and albumin concentrations, ICG extraction), hepatic venous pressure gradient, cardiac index and systemic vascular resistance on the one hand and renal blood flow on the other. No significant correlation was found between glomerular filtration rate and liver tests. In conclusion, in patients with cirrhosis and ascites, renal hypoperfusion is not related to the severity of liver disease.
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PMID:Renal hemodynamics in patients with cirrhosis: relationship with ascites and liver failure. 828 84

Chronic hypoxia produces pulmonary artery hypertension through vasoconstriction and structural remodeling of the pulmonary vascular bed. The present study was designed to test the effect of heparin administered via aerosol on the development of hypoxic pulmonary hypertension. Anesthetized, intubated, and mechanically ventilated guinea pigs received an aerosol of either 2 ml normal saline (hypoxic control, HC) or 4,500 units of heparin diluted in 2 ml normal saline via an ultrasonic nebulizer (hypoxic heparin, HH). After 24 h of recovery, the animals were placed in a hypoxic chamber (10% O2) for 10 days. Animals kept in room air served as normoxic controls (NC). Hypoxia increased mean pulmonary artery pressure from 11 +/- 1 (SEM) mm Hg in NC to 24 +/- 1 mm Hg in HC (p < 0.05). Pulmonary artery pressure was significantly lower in HH-treated animals (20 +/- 1 mm Hg, p < 0.05 versus HC) as was the total pulmonary vascular resistance (0.15 +/- 0.01 in HH versus 0.20 +/- 0.01 mm Hg/ml/min in HC, p < 0.05). There was no difference in cardiac output (146 +/- 12 in HH versus 126 +/- 7 ml/min in HC), hematocrit (57 +/- 2 in HH versus 56 +/- 2% in HC), partial thromboplastin time (30 +/- 2 in HH versus 32 +/- 3 s in HC), prothrombin time (46 +/- 1 in HH versus 48 +/- 4 s in HC) or room air arterial blood gas values after 10 days of hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of aerosol heparin on the development of hypoxic pulmonary hypertension in the guinea pig. 831 7


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