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At least 19 recordsLinked to original sources

The pathogenesis of Trypanosoma congolense infection in calves. IV. The kinetics of blood coagulation.

Blood coagulation studies showed there was a pronounced thrombocytopenia and hypofibrinogenemia in Holstein calves infected with Trypanosoma congolense TREU 112. There was also ineffective thrombopoiesis characterized by an increased megakaryocytic mass, reduced uptake of 35S-methionine into peripheral blood platelets and a normal platelet lifespan. There was an increased uptake of isotopic label into fibrinogen and a shortened half life indicating a consumptive error with increased peripheral use of fibrinogen. No consistent abnormalities were found in ethanol gelation, partial thromboplastin time, clot retraction and lysis or plasminogen assay. Fibrin split products were rarely detected. These findings suggest that in the chronic form of bovine trypanosomiasis there is a partially compensated consumption coagulopathy.

Animals

[Effect of an intravenously administered phosphatidylserine emulsion on blood coagulation and blood system indices].

Experiments on white rats and rabbits showed that intravenous injection of phosphatidylethanol amine- and sphyngomyelin-stabilized phosphatidylserin emulsion produced hypocoagulemia. The effect was observed immediately after injection of the drug, reached a maximum after one hour and returned to normal following 24 hours. The changes became more intensive as the dose was increased and could be reproduced during repeated administrations over a period of ten days. The arterial blood pressure, velocity of the blood flow and volume of the circulating blood remained unchanged. There were no appreciable changes in the peripheral blood parameters or in bone marrow hemopoiesis on repeated administrations over a period of thirty days.

Animals

Apgar score and blood coagulation factors.

Blood coagulation tests were performed in 93 newborn infants with different Apgar score at the 1st and 5th minutes of life. The laboratorial determinations were periodically performed at 0, 24 and 48 hours of life. The following tests were performed: bleeding time, whole blood clotting time, prothrombin time, kaolin-cephalin clotting time, thrombin time, dosage of factors I, V, VIII and X, clot retraction, platelet count, englobulin lysis time and the tourniquet test. Immediately after birth, the mean values of the blood coagulation factors were significantly different among the groups, with the exception of the whole blood clotting time and the platelet count. Those differences were due to the presence of the more depressed neonates. Although these results could indicate some degree of hepatic damage, it was apparent that an activation of the blood coagulation mechanisms took place, leading to a consumption coagulopathy. The infants who died (10) presented clinical and laboratorial data suggestive of disseminated intravascular coagulation (DIC). Necroscopic findings of microthrombosis in the liver and in the central nervous system were diagnosed in two infants.

Apgar Score

Progestational agents and blood coagulation. VIII. Effect of low-dose, alternate-day, estrogen-progestin combinations on blood coagulation factors in man, with a special note on the effect of freezing of blood samples.

Changes in the blood coagulation system were studied in three groups of 20 patients each. The first group received 0.5 mg. of norethindrone daily, plus 0.06 mg. of ethinyl estradiol on alternate days from cycle Day 5 through 25. The second group, all of whom had been fitted with an intrauterine contraceptive device (IUD), received no hormonal treatment and served as a control group. The third group received 0.5 mg. of norethindrone daily, combined with 0.045 mg. of ethinyl estradiol given on alternate days from cycle Day 5 through 25. Blood samples were drawn prior to the initiation of the study and after three months of treatment. Tests of the following parameters of the blood coagulation system were performed: direct platelet count; platelet adhesiveness; prothrombin time; thrombin time; fibrinogen; factor II assay; activity of factors V, VII, VIII, IX, and X; antithrombin III; and fibrin/fibrinogen degradation products. For a number of these factors, both fresh and frozen blood samples were examined. It was concluded that the two treatment regimens, with the use of alternate-day estrogen administration over a three-month period, had no clinically significant effect on the blood coagulation system.

Adolescent

Progestational agents and blood coagulation. VII. Thromboembolic and other complications of oral contraceptive therapy in relationship to pretreatment levels of blood coagulation factors: summary report of a ten-year study.

During a ten-year period, 348 women were studied for a total of 5,877 patient months in four separate studies relating oral contraceptives to changes in hematologic parameters. Significant increases in certain factors of the blood coagulation and fibrinolysin systems (factors I,II,VII,VIII,IX, and X and plasminogen) were observed in the treated groups. Severe complications developed in four patients. All four had an abnormal blood coagulation profile, suggesting "hypercoagulability" before initiation of therapy. Some of these findings represented the most extreme abnormalities seen in the entire group of patients; some increased further during therapy. One of these patients developed a myocardial infarction before receiving any medication, shortly after the base-line values were obtained. One patient developed retinopathy 19 months after she began therapy, and another developed thrombophlebitis after 27 months of therapy. The fourth patient developed thrombophlebitis 14 days after initiation of contraceptive therapy. All four patients were of the A or AB blood group. Previous studies suggested the possiblility of increased propensity for thromboembolic episodes in patients possessing the A antigen. It appears from these data that hematologic work-ups may be useful in women who are about to start long-term oral contraceptive therapy.

Adult

Fasting (acute energy deprivation) in man: effect on blood coagulation and fibrinolysis.

Blood coagulation and fibrinolysis parameters were studied during 10 days of total fasting in healthy, normal weight males. A reduction of plasma levels of factor VIII activity with a concomitant decrease in factor VIII antigen was found, without other laboratory evidence for a disseminated intravascular coagulation. The effect of 10 days' starvation on blood coagulation appears to be small but the effect of more prolonged starvation might implicate impaired hemostasis.

Adult

[Characteristics of blood coagulation and of the red blood in patients with an arteriosclerotic lesion of the abdominal aorta].

The values of blood coagulation and red blood were studied in 74 patients with various forms of atherosclerotic affection of the abdominal aorta and its branches. Tendency towards hypercoagulation both before operation and in various periods after it was revealed in these patients. The development of thrombotic complications is preceded by a marked increase in the fibrinogen level and in the blood platelet count. High hematocrit with a relatively small erythrocyte count and hemoglobin concentration was revealed, which was linked with the spheric shape of the erythrocytes. It is concluded that a complex of antithrombotic therapy is necessary; it should be begun before the operation and continued particularly actively in the first two postoperative weeks.

Adult

Marathon run I: effects on blood coagulation and fibrinolysis.

Blood coagulation and fibrinolysis were assessed in 13 Finnish amateur runners aged 31 to 48, and one 65-year old taking part in a non-competitive marathon (42.2 km). After the run the mean values of partial thromboplastin time showed a very significant shortening, whereas the mean values of the prothrombin time and of plasma fibrinogen were not significantly altered. The mean values of euglobulin lysis time were significantly shorter and the mean values of fibrin degradation products increased highly significantly. After the run, protamine sulphate was positive or strongly positive in all subjects, whereas the ethanol gelation test was negative in all runners; no cryofibrinogen was detected in any participant. Thus, running a marathon race affects the haemostatic balance and activates the fibrinolytic mechanism. The effects of training and physical fitness on the above parameters are discussed.

Adult

[Initiation in vivo of blood coagulation. The role of white blood cells and tissue factor (author's transl)].

Tissue factor is an ubiquitous phospholipid-protein complex, which triggers blood coagulation through the so-called extrinsic pathway. Reactions initiated by tissue factor bypass many of the early stages of coagulation (contact phase) and involve factors VII, X, V, II and fibrinogen but also factor IX (and VIII) as it was recently demonstrated. So, it appears that tissue factor has a key-role in the haemostasic process as it has been suggested by the mildness or the absence of haemorrhagic syndrome in contact factors deficiencies. Tissue factor activity has been found in many types of cells, especially in white bloods cells. Experimental studies have demonstrated the presence of tissue factor activity in polymorphonuclears, lymphocytes, monocytes (or macrophages). This activity is enhanced by gram-negative endotoxin stimulation, inflammation, cell mediated immunologic phenomena or malignancy. These data are in good agreement with a wild range of features observed in human pathology: fibrin deposits in inflammatory lesions, disseminated intravascular coagulation (DIC) during the course of gram-negative septicemias or acute promyelocytic leukemias, local thrombi at the early phase of graft rejection. The protective effect of a phospholipase C against DIC induced in rats by tissue factor infusion suggests in the future, a specific therapy would be possible in man that, in the frequent clinical conditions involving clotting activation through tissue factor pathway.

Animals

The effects of combined platelet and leukapheresis on the blood coagulation system.

Analysis of blood coagulation was done on samples of blood collected from ten donors undergoing combined platelet and leukapheresis using the Haemonetics Model 30 Blood Processor. Blood samples were obtained from the donors prior to, during, and following pheresis. Blood was also obtained from the blood-return line after the first collection of leukocytes and platelets, but before it was returned to the donor. Although the citrate anticoagulant was returned to the donor and there were some decreases in the concentrations of fibrinogen, platelets, and factors V and VIII, there were no changes of sufficient degree to suggest that development of a potential bleeding disorder. In addition there was no evidence to suggest that any activation of blood coagulation occurred during the pheresis or that thrombogenic substances were returned to the donors. Combined platelet and leukapheresis using the Haemonetics Model 30 Blood Processor, therefore, do not appear to subject the donor to risks for either bleeding or thrombotic complications.

Blood Coagulation

[Blood coagulation activity and fibrinolysis in umbilical vein blood of healthy and asphyxiated newborn infants].

In two groups of 35 healthy and 15 asphyctic newborns the factors of blood coagulation and fibrinolysis were determined and compared with the normal values of non-pregnant women. The study demonstrates an increased coagulability and increased fibrinolytic activity at decreased levels of most of the single factors in the umbilical vein blood of the newborn. There is a statistically significant decrease of the concentration of plasminogen and increase of the concentration of fibrin degradation products and fibrin monomers in the groups of asphyctic newborns as compared with healthy newborns. These results may be considered as factors in the etiology of the respiratory distress syndrome of the newborn resulting in the formation of hyaline membranes. An increased tendency to hemorrhages in asphyctic newborn due to a hypocoagulation of the umbilical vein blood cannot be suggested by these results. The study confirms and supplements previous research findings from our laboratory and from others reported in the literature.

Adult