Factor IX of the blood coagulation system: a review

Factor IX is a factor of the blood coagulation system. Its activation occurs on the surface of phospholipid membranes. It can be activated by the factor VIIa-TF (tissue factor)-Ca2+ complex via an extrinsic pathway and by factor XIa in the presence of Ca2+ via the intrinsic pathway of blood coagulation system activation. The activated factor IXa is a serine proteinase. The main function of the activated factor IXa in complex with factor VIIIa and phospholipids in presence of Ca2+ consists of the activation of factor X. Factor IX is synthesized in the liver and is subject to a number of posttranslational modifications including gamma-carboxylation, beta-hydroxylation, and glycosylation. It forms a subgroup of vitamin K-dependent plasma proteins including factors VII and X and protein C characterized by identical domain structures having high levels of homology. Factor IX consists of an NH2-terminal Gla domain, two epidermal growth factor (EGF)-like domains, and a C-terminal domain containing Ser in its active site. Factor IX deficiency in human plasma results in the disease known as hemophilia B.     

Pathophysiological response of the blood coagulation system in acute glomerulonephritis

1. The effects of clonidine on blood pressure, cerebral norepinephrine content and vascular structures of the kidneys were investigated in 21 SHR. Although the body weight was not affected by long term clonidine treatment up to 36 weeks, the syatolic blood pressure was significantly reduced. The reduction of the blood pressure was already obvious after 1 week administration of clonidine but the effect was more prominent after long term treatment of 30 weeks or longer. 2. The cerebral norepinephrine content was significantly lower in SHR, regardless of with or without clonidine treatment, than in the control Wistar rats. Although the cerebral norepinephrine content was slightly increased following clonidine treatment SHR, the increase was not statistically significant. 3. Angiographic study of the kidneys revealed a poor opacification of the blood vessels and glomeruli in SHR compared with the control Wistar rats. There was no difference in the sizes of the arcuate and interlobular arteries in SHR and the control Wistar rats, although the medial muscular hypertrophy of the arteries was slightly more prominent in the SHR histologically. The more prominent in the SHR histologically. The angiographic and histologic findings of the renal arteries were not altered following long term clonidine treatment. A possibility was considered that the renal arterioles are mainly functionally affected in SHR.     

The effect of the chronic internal administration of the new Russian n-3 polyunsaturated fatty acid concentrate--epaden--on blood coagulation system indices in rabbits

Daily oral 6-week administration of epaden in a dose containing 0.3 g eucosopentanoic acid and 0.05 g docosahexaenoic acid caused decrease in collagen-induced platelet aggregation in rabbits in vivo and in the activity of the tissue type plasminogen activator, as well as reduction in the level of antithrombin III cofactor activity. No changes were encountered in ADP-induced aggregation, in the platelet count, in platelet adhesion to collagen, and in activated partial thromboplastin time.     

The influence of smoking and of oral and transdermal nicotine on blood pressure, and haematology and coagulation indices

Nicotine is helpful in stopping smoking but its influence on cardiovascular risk factors is incomplete. Our aim was to determine its effect on blood pressure, routine haematology indices, and coagulation indices relevant to thrombosis. Eighteen subjects were seen whilst smoking (cotinine levels 1119 +/- 414 ng/ml), again after stopping smoking but while using nicotine chewing gum and/or skin patches (392 +/- 198 ng/ml), and again when not using nicotine (cotinine undetectable). There were no significant changes in blood pressures, platelet count, mean platelet volume, viscosity or anti-thrombin III. However, white blood cell count (p = 0.003), lymphocyte count (p = 0.016), red blood cell count (p = 0.02), haemoglobin (p <0.001), fibrinogen (p <0.001) and von Willebrand factor (p = 0.001) all fell between the first and second samples (when still using nicotine) but not between the second and third samples (when off nicotine). Oral and/or transdermal nicotine does not influence blood pressure or the haematology and coagulation indices we have measured.     

Effects of Russell''s viper venom on blood coagulation, platelets and the fibrinolytic enzyme system

Abnormalities of second-wave platelet aggregation were demonstrated in 17 of 33 asthmatic patients in whom drug and diet intake were controlled in the hospital. Mean abnormal responses were significantly greater after epinephrine- (p less than 0.001), adenosine diphosphate-(less than 0.001), collagen- (p = 0.01), and thrombin- (p less than 0.001) induced platelet aggregation in patients with immunologically mediated asthma and serum IgE levels greater than 250 U/ml as compared to patients without immunologic factors and/or normal controls. Mean pollen-specific radioallergosorbent (RAST) binding was also significantly higher in patients with abnormal aggregation as compared to normal platelet responders (p = 0.02). Release of serotonin generally reflected abnormal aggregation patterns in asthmatic patients. Platelet factor 4 release was significantly decreased in the same groups of patients. These results suggest that the allergic state may affect platelet membrane responsiveness to multiple aggregating agents.     

Dietary fatty acids and blood coagulation

Factor VII coagulant activity (VIIc) is a risk factor for coronary heart disease (CHD). Plasma VIIc is positively associated with dietary fat intake, suggesting that fat-rich diets are accompanied by a hypercoagulable state. Reduction in total fat consumption is followed by a decrease in VIIc within 24 h. In adults taking diets rich in long-chain saturated fatty acids, a postprandial increase in VIIc occurs after a fatty meal irrespective of its fat composition. This effect has dose-response characteristics, persists for several hours, and is due to activation of factor VII. There is no acute effect of dietary fat on factor VII antigen (VIIag) concentration, but VIIag is positively related to dietary fat intake. More studies are needed on the effects of dietary fat composition on fasting and postprandial factor VII. Dietary fat appears to influence both the atherosclerotic and thrombogenic components of CHD.     

混凝法在选矿废水处理中的应用现状及发展

简要描述选矿废水的来源、特点及各种处理方法的优缺点。阐述混凝法的作用机理,着重分析混凝剂、水质状况及水力条件等因素对选矿废水处理产生的影响,介绍混凝法在铅锌矿、铁矿、黄金、钨矿和磷矿等废水处理的应用现状。最后指出混凝法在选矿废水处理中的发展方向是要加强对混凝作用机理与影响因素的研究,加大对高效混凝剂的研发,同时将混凝法与尾矿库自然沉降、浓密机技术有机结合,制定合理流程,实现选厂废水零排放。     

Effects of eleutherococcus, elton, leuzea, and leveton on the blood coagulation system during training in athletes

Three hermetics are assessed: chemically hardened Delton, light-hardened Estiseal, and composite Evikrol. The study was carried out in 126 children aged 6 years. The decrease of the increment of dental caries depends on the retention of hermetics on the occlusion surface of the teeth, and the efficacy of caries prevention in permanent teeth is much higher if hermetic sealing of fissures and fossae is combined with local fluorine prophylaxis and oral hygiene. All types of hermetics can be used to prevent permanent teeth caries, but chemically hardened ones should be preferred.     

Influence of cation dyes on blood coagulation

Experiments on rabbits showed that intravenous injection of dyestuffs of the thionine series (toluidine blue, azur A, 1:9 dimethylene blue) was accompanied by hypofibrinogenemia, a decrease in the concentration of prothrombin complex factors, thrombocytopenia and the lowering of the blood platelets adhesion against the background of delayed blood thrombogenesis. The blood heparin tolerance and the amount of free heparin were sharply lowered. The authors consider that the hypocoagulative effect of cationic dyestuffs on the blood was caused by the thrombocytopenia and by the lowering of the platelet aggregation activity.     

The indices of the antioxidant system and the status of the cerebral blood supply in patients with an ischemic stroke on apitherapy

It has been established that the use of apitherapy (pollen and propolis) to treat patients with ischemic insults leads to deeper positive shifts in indices of the antioxidant system and brain blood supply. This, in its turn, makes for rapid and complete restoration of disturbed and lost functions of the patients' organism.