PubMed HealthSearch

SEARCH · PubMed Health

Results for “Blood Coagulation Effects”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Alkaloids of tobacco and blood coagulation: effect of nicotine on thrombin and fibrinogen.

An alkaloid of tobacco, nicotine, affected the clot-formation property of the enzyme, thrombin, on the substrate, plasma or fibrinogen (thrombin time). Higher concentrations of nicotine retarded the clot-formation property of thrombin. By decreasing the nicotine concentration in the clotting mixture, the clotting time of thrombin was accelerated. Nicotine also modified the clot formation property of plasma or fibrinogen to thrombin, and this effect was dose dependent. From this experimental evidence, it is suggested that nicotine does alter the clot-forming properties of thrombin on fibrinogen.

Alkaloids

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

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

Effect on blood coagulation and fibrinolysis in women using norethisterone or a combination of ethinyloestradiol and quingestianol.

Oral contraceptives of the combined type and contraceptives containing only progestagen were studied for their effect on blood coagulation and fibrinolysis. Several blood parameters were determined in 13 women before and during the 3rd month of use of either 0.3 mg norethisterone alone or 0.05 mg ethinyloestradiol combined with 0.5 mg quingestianol. Blood samples were obtained on days 2--4, 9--11, 16--18 and 23--25 of the menstrual cycle. Except on days 16--18, a significantly increased fibrinolytic activity and a significantly increased variation in plasminogen were observed in women using the combined type of contraceptives, but not in the women using contraceptives containing only norethisterone. The other variables studied were not significantly changed, which might be due to the doses and types of progestagens used in the present series.

Adult

An experimental study on the effect of plasma expanders on blood coagulability.

The effect of various plasma expanders on blood coagulation was studied using the thromboelastography (TEG). Solutions of 5, 10, 20, and 50% concentration of each expander (6% low molecular weight hydroxyethyl-starch (6% Hespander), 3% dextran-40, 6% high molecular weight hydroxyethyl-starch (6 HES), and 6% dextran-70) or solvent (lactated Ringer solution and normal saline) in blood were prepared and their coagulability was examined by TEG. In the low molecular weight plasma expanders (6% Hespander and 3% dextran-40), in general, the coagulability decreased when the concentration was increased. In the high molecular weight plasma expanders (6 HES and 6% dextran-70), the coagulability increased slightly at low and high concentrations and the coagulability was reduced. As a conclusion, at clinically used concentrations of less than 20% in blood, changes in the TEG of the plasma expanders are minimum and have no clinical significance.

Blood Coagulation

Degradation products of fibrinogen by elastase-like neutral protease from human granulocytes. Characterization and effects on blood coagulation in vitro.

We investigated the effect of elastase-like neutral protease isolated from human granolocytes on human fibrinogen. Dependent on enzyme concentration and time of incubation, the elastase-like protease induced a progressive degradation of fibrinogen. Analysis of the remaining polypeptide chains showed a high susceptibility of the Aalpha- and low susceptibility of the gamma-chain of fibrinogen towards the proteolytic action of the enzyme. The split products were characterized by polyacrylamide gel electrophoresis and two-dimensional immunoelectrophoresis. They showed antigenic determinants of fibrinogen and of plasmin-induced proteolysis products D and E. The cleavage fragments isolated by gel chromatography had distinct molecular weights. Coagulability of fibrinogen by thrombin was inhibited according to the concentration of the protease and the time of incubation. Split products of fibrinogen with higher molecular weight prolonged the coagulation time of native fibrinogen, whereas low molecular weight fragments were ineffective.

Blood Coagulation

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

The effect on blood coagulation of the exclusive use of transfusions of frozen red cells during and after cardiopulmonary bypass.

The essentially indefinite storage life of previously frozen erythrocytes (PFE), combined with the virtual freedom from hepatitis, high 2,3-diphosphoglycerate (2,3-DPG) content, and low level of HL-A antigens, should make its use in open-heart surgery attractive. However, since the suspension medium for PFE is usually saline, the potential exists for creating a hemorrhagic diathesis by accentuating the dilution of plasma procoagulants by the pump prime. To test this possibility, we used PFE exclusively in transfusing a group of 13 open-heart surgery patients; they were given no plasma or platelets. A control group of 12 open-heart surgery patients were transfused with only shelf blood. Determination of prothrombin times (PT), partial thromboplastin times (PTT), platelets, and fibrinogen were done at various intervals. No clinically significant differences between the two groups were seen in any of these parameters at any interval, and there was no significant difference between the groups in amount of chest tube drainage or transfusions in the first 24 hours. It is concluded that most open-heart surgery can be safely performed exclusively with frozen blood.

Blood Cell Count

[Effect of blood coagulation on the functional activity of transport adenosine triphosphatases in erythrocytes].

Membranes of red blood cells from the whole blood and the blood containing anticoagulant were comparatively studied in 30 donors. It was shown that their destabilization during blood coagulation in vitro was caused by a decrease in the quantity of sulfhydryl groups in red blood cell lipoprotein complexes that deteriorated not only structural but also functional state of erythrocytic membranes due to the changes in the activity of their transport ATPases.

Adenosine Triphosphatases

Norlestrin-induced pseudopregnancy in the baboon. Effects on blood coagulation and endocrine glands during attempted production of Sheehan's syndrome.

Production of Sheehan's syndrome was attempted. As it was not possible to obtain pregnant baboons initially, pseudopregnancy was induced with norlestrin, 2.k mg., for 3 and 4 months, respectively. Sheehan's syndrome was not produced with massive hypovolemic shock but failure to obtain true pregnancy has given serendipitous information on the long-term action of norlestrin on the pituitary and its target organs. Unusual abundance of prolactin acidophils and decrease of growth hormone acidophils was found. Further studies will be necessary to show the possible significance of these findings. As fibrin degradation products did not appear in the serum, we can make no inference about the necessity of intravascular coagulation for the production of Sheehan's phenomenon. Finally one animal became pregnant. Sheehan's phenomenon was not produced in her despite induction of intrapartum hypovolemic shock. Histologic findings in her pituitary resemble those of the pseudopregnant animals.

Animals

The effects of 7.5% NaCl/6% dextran 70 on coagulation and platelet aggregation in humans.

The combination solution of 7.5% NaCl/6% dextran 70 (HSD) administered IV gives hemodynamic improvement in the treatment of hemorrhagic hypotension. Since earlier dextran solutions were reported to interfere with blood coagulation, the effects of HSD on the prothrombin time (PT), the activated partial thromboplastin time (APTT), platelet aggregation, and platelet concentration were studied. The HSD mixed with human plasma (1:5 and 1:10) slightly prolonged PT, but had no effect on the APTT, compared with saline controls. The HSD also decreased human platelet aggregation at the 1:5 dilution. In separate mixing studies, the hypertonic saline component of HSD was associated with the prolongation of PT and decreased platelet aggregation. The data from these studies indicate that at its proposed therapeutic dose, HSD is expected to have minimal effect on blood coagulation.

Adult

Long-term profile of a new progestin.

Major complications attributable to oral contraceptives (OCs) may occur in the circulatory system. The inherent risk factors, such as race and family history, are unchangeable. Others may be altered by patient counseling and subsequent adjustment of certain behaviors. Hypercoagulability is estrogen dose related. Older, high-dose-estrogen OC users were at 40% increased risk of mortality from thromboembolic phenomena. Reduction in estrogen content has unmasked the androgenic effects of some synthetic progestogens. These effects may include progression of atherogenesis, effected through changes in cholesterol and lipoproteins; reduction in sex hormone binding globulin (SHBG), which enhances the androgenic effect; and changes in carbohydrate metabolism. This review of clinical findings is based on four studies; three had prospective cohort designs, and one was a prospective randomized comparison of a norgestimate-containing OC with a norgestrel-containing one. Numbers of subjects ranged from 20 to 59,701; the largest evaluated 343,348 cycles of treatment. Study intervals were from 4 to 24 months. The findings reported here are from the individual studies. 1. The normal value for cholesterol is less than 200 mg/dL. Of 2,197 women who met this cut-off point, 95% remained below it after 6 months of treatment. Of 756 who initially exceeded this value, 25% were below after 6 months and 75% remained above it. All studies to date have demonstrated that norgestimate produces consistent and significant elevations in high-density lipoprotein levels and variable change in low-density lipoproteins. A similar effect was noted on serum triglyceride values.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Coagulation

[Effects of aromatic bisamidines on blood coagulation and fibrinolysis].

The effect of the aromatic diamidine derivative 2,6-bis (4-amidinobenzyl)-cyclohexanon-(1) on blood coagulation and fibrinolysis in vitro and in vivo was compared with that of the benzamidine derivative 4-amidinophenyl pyruvic acid and the aromatic diamidine derivative 4,4'-diamidinophenoxypentane. 2,6-Bis(4-amidinobenzyl)-cyclohexanon-(1) was found to be a strong inhibitor of the clotting enzyme thrombin. Because of the toxic side effects and pharmacokinetic properties of both diamidine derivatives their in vivo use as anticoagulants is limited.

Amidines