Cold Promoted Activation of Factor VII

1972 ◽  
Vol 28 (02) ◽  
pp. 155-168 ◽  
Author(s):  
H Gjønnæs

SummaryThe cold promoted shortening of the thrombotest-times occuring in the plasmas of the majority of women on oral contraception or in the last trimester of pregnancy when incubated overnight at 0°–4° was investigated.The short thrombotest-times were caused by activation of factor VII in a time consuming reaction. Activation was also revealed in the intrinsic coagulation system, but the changes in the activities of coagulation factors other than factor VII were small.Comparison was made between clot promoting effects of cooling and contact, and it was concluded that while contact apparently exerted its main effect in the intrinsic system, cooling predominately activated the extrinsic plasma coagulation system.The cold promoted activation of factor VII seemed to be brought about by an activator.

2019 ◽  
pp. 72-77
Author(s):  
I. V. Schastlivtsev ◽  
K. V. Lobastov ◽  
S. N. Tsaplin ◽  
D. S. Mkrtychev

For many years, there has been no model capable of explaining the complex processes of interaction between various bloodclotting factors leading to a stop of bleeding. One of the most successful models able to partially reflect the mechanisms of hemostasis for a long time was the cascade theory. The cascade model perfectly explains the processes occurring during coagulation in vitro, but was completely inadequate in attempts to evaluate the processes occurring in vivo. A significant drawback of the cascade model is the impossibility to trace the interaction of cells carrying the tissue factor, platelets and plasma coagulation factors on their surface, since these conditions cannot be imitated. The cell theory, which has replaced the cascade theory, pays attention not only to the interaction of plasma coagulation factors, but also takes into account the role of platelets as important participants of coagulation processes. It is based on a four-stage reaction cascade that includes the following stages: initiation, amplification, propagation, and termination.The cell theory of hemostasis is able to reflect the complex process of interaction of all the links of hemostasis and answer questions related to the problems in patients with disorders of the coagulation system. The cell theory of hemostasis allows to reflect more precisely the processes of hemostasis in vivo and to interpret correctly the results of tests and pathophysiological mechanisms of disorders of the coagulation system. Global tests (thrombin generation assay, thromboelastography, thrombodynamics) used for hemostasis system evaluation are more complimentary with cell theory of hemostasis.


2020 ◽  
Vol 17 (3) ◽  
pp. 101-108
Author(s):  
A. V. Kuligin ◽  
A. V. Lushnikov ◽  
E. E. Zeulina

Massive obstetric hemorrhage is one of the most threatening complications of pregnancy, delivery and early postpartum period, which are part of the triad of leading causes of maternal mortality both in the world and in the Russian Federation. In recent years, to stop coagulopathy, which is one of the clinical manifestations of massive obstetric hemorrhage, recombinant and plasma factors of the blood coagulation system are successfully used, which include a concentrate of prothrombin complex and activated coagulation factor VII (eptacog alfa activated). The authors present results of successful consistent use of the blood coagulation system factors within comprehensive intensive care of coagulopathy in a patient with massive obstetric hemorrhage.


Author(s):  
В.И. Павлов ◽  
Н.П. Александрова ◽  
В.И. Карандашов

В статье рассматривается клинический случай развития острого венозного тромбоза у молодого спортсмена после выступления в сложных климатических условиях. Пациенту был поставлен диагноз «Окклюзионный тромбоз подключичной и подмышечной вен справа» и проведен курс консервативного лечения. Массивная антикоагулянтная терапия улучшила состояние больного, но не привела к нормализации тромботического потенциала крови. Генетическое исследование плазменных факторов системы свертывания крови выявило у пациента повышенную предрасположенность к возникновению тромбозов. Амбулаторное применение фотогемотерапии синим светом полностью нормализовадо гемостаз молодого спортсмена. The article discusses the clinical case of acute venous thrombosis in a young athlete after game in diffi cult climatic conditions. The diagnose was «Occlusive thrombosis of the subclavian and axillary veins on the right», and the patient received a course of medical treatment. Massive anticoagulant therapy improved patient’s state, but did not lead to normalization of blood thrombotic potential. Genetic testing of plasma factors of blood coagulation system revealed in patient an increased predisposition to thromboses occurrence. Outpatient use of photohemotherapy with blue light completely normalized the hemostasis of young athlete.


Author(s):  
Д.Б. Флоринский ◽  
А.В. Пшонкин ◽  
А.В. Полетаев ◽  
Д.В. Федорова ◽  
Е.А. Серегина ◽  
...  

Введение. Редкие коагулопатии представляют собой гетерогенную группу наследственных заболеваний, для которых характерен количественный или качественный дефицит факторов свертывания крови. Цель исследования: проанализировать частоту встречаемости и клинические проявления редких коагулопатий у детей, определить корреляции степени тяжести клинических проявлений с активностью дефицитного фактора. Материалы и методы. На основании анализа деперсонифицированной базы данных из общего числа визитов к врачам, специализирующимся на болезнях свертывающей системы, с января 2017 г. по декабрь 2019 г. была изучена частота встречаемости редких коагулопатий. Оценивали основные локализации кровотечений и степень выраженности клинических проявлений, используя шкалу педиатрического опросника кровоточивости (англ. Pediatric Bleeding Questionnaire, PBQ). Анализ корреляции между величиной PBQ и значением активности дефицитного фактора проводили с применением метода Пирсона. Результаты. За 2017–2019 гг. в ФГБУ НМИЦ ДГОИ им. Д. Рогачева Минздрава России диагностировано 47 пациентов с редкими коагулопатиями: 14 пациентов с гипо/афибриногенемией, 21 пациент с дефицитом фактора VII, 5 пациентов с дефицитом фактора XI, 3 пациента с комбинированным дефицитом витамин К-зависимых факторов, 2 пациента с дефицитом фактора V, 1 пациент с дефицитом фактора X и 1 пациент с сочетанным дефицитом факторов V и VIII. Заключение. Распространенность той или иной редкой коагулопатии подвержена этническим особенностям населения и не всегда пропорциональна ожидаемой частоте. Требуется больше данных для установления местных особенностей распространения редких коагулопатий и выработки адекватных критериев диагностики. Background. Rare bleeding disorders are a heterogeneous group of hereditary diseases characterized by a quantitative or qualitative deficiency of blood coagulation factors. Objectives: to analyze the incidence and clinical manifestations of various rare bleeding disorders in children, to identify correlations of clinical manifestations severity with the activity of a deficient factor. Patients/Methods. According depersonalized database of the total number of visits (from January 2017 to December 2019) to doctors specializing in diseases of the coagulation system, the incidence of rare bleeding disorders was studied. The main sites of bleeding and the severity of clinical manifestations were assessed with the Pediatric Bleeding Questionnaire (PBQ) scale. Pearson method was used to analyze the correlation between the PBQ value and the deficient factor activity. Results. For years 2017–2019 at Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology 47 patients with rare bleeding disorders were diagnosed, оf these, 14 patients with hypo/afibrinogenemia, 21 patients with factor VII deficiency, 5 patients with factor XI deficiency, 3 patients with combined deficiency of vitamin K-dependent factors, 2 patients with factor V deficiency, 1 patient with factor X deficiency and 1 patient with combined factors V and VIII deficiency. Conclusions. The prevalence of one or another rare bleeding disorder is vulnerable to ethnic characteristics of the population and is not always proportional to the expected frequency. More data is required to establish the local characteristics of the spread of rare bleeding disorders and to develop adequate diagnostic criteria.


1998 ◽  
Vol 79 (01) ◽  
pp. 104-109 ◽  
Author(s):  
Osamu Takamiya

SummaryMurine monoclonal antibodies (designated hVII-B101/B1, hVIIDC2/D4 and hVII-DC6/3D8) directed against human factor VII (FVII) were prepared and characterized, with more extensive characterization of hVII-B101/B1 that did not bind reduced FVIIa. The immunoglobulin of the three monoclonal antibodies consisted of IgG1. These antibodies did not inhibit procoagulant activities of other vitamin K-dependent coagulation factors except FVII and did not cross-react with proteins in the immunoblotting test. hVII-DC2/D4 recognized the light chain after reduction of FVIIa with 2-mercaptoethanol, and hVIIDC6/3D8 the heavy chain. hVII-B101/B1 bound FVII without Ca2+, and possessed stronger affinity for FVII in the presence of Ca2+. The Kd for hVII-B101/B1 to FVII was 1.75 x 10–10 M in the presence of 5 mM CaCl2. The antibody inhibited the binding of FVII to tissue factor in the presence of Ca2+. hVII-B101/B1 also inhibited the activation of FX by the complex of FVIIa and tissue factor in the presence of Ca2+. Furthermore, immunoblotting revealed that hVII-B101/B1 reacted with non-reduced γ-carboxyglutaminic acid (Gla)-domainless-FVII and/or FVIIa. hVII-B101/B1 showed a similar pattern to that of non-reduced proteolytic fragments of FVII by trypsin with hVII-DC2/D4 on immunoblotting test. hVII-B101/B1 reacted differently with the FVII from the dysfunctional FVII variant, FVII Shinjo, which has a substitution of Gln for Arg at residue 79 in the first epidermal growth factor (1st EGF)-like domain (Takamiya O, et al. Haemosta 25, 89-97,1995) compared with normal FVII, when used as a solid phase-antibody for ELISA by the sandwich method. hVII-B101/B1 did not react with a series of short peptide sequences near position 79 in the first EGF-like domain on the solid-phase support for epitope scanning. These results suggested that the specific epitope of the antibody, hVII-B101/B1, was located in the three-dimensional structure near position 79 in the first EGF-like domain of human FVII.


1976 ◽  
Vol 35 (02) ◽  
pp. 403-414 ◽  
Author(s):  
Terence Davies ◽  
Gillian Fieldhouse ◽  
George P. McNicol

SummaryThe effects on the haemostatic mechanism of oestrogen therapy, given to prevent bone loss in post-menopausal women, have been investigated. Oestriol succinate was given orally to 10 women at a level of 2 mg/day for 1 month and for a further 3 months with incremental increase of 2 mg each month. 6 of the 10 women were subsequently treated with 25 μg/day orally of ethinyl oestradiol. Oestriol succinate therapy resulted in a small increase in the level of factor VII, a decrease in factor VIII concentration and increased sensitivity of platelets to aggregating agents. Ethinyl oestradiol treatment resulted in much more widespread changes with marked increases in coagulation factors VII, VIII, IX and X, decreased levels of antithrombin and dramatic increases in circulating plasminogen levels and euglobulin lysis activity. The data suggested that the nature of oestrogens employed therapeutically is important in determining the qualitative and quantitative effect of oestrogen therapy on components of the haemostatic mechanism.


1976 ◽  
Vol 35 (02) ◽  
pp. 295-304 ◽  
Author(s):  
B Østerud ◽  
M Miller-Andersson ◽  
U Abildgaard ◽  
H Prydz

SummaryAntithrombin III, purified to homogeneity according to Polyacrylamide gel disc electrophoresis and immunoelectrophoresis, inhibited the activity of purified factor IXa and Xa, whereas factor VII was not inhibited either in the active or in the native form.Antithrombin III is the single most important inhibitor of factor Xa in plasma. Factor Xa does not, however, reduce the activity of antithrombin III against thrombin.


1976 ◽  
Vol 35 (03) ◽  
pp. 607-619 ◽  
Author(s):  
Allan T. van Oosterom ◽  
Herman Mattie ◽  
Wim Th Hermens ◽  
Jan J. Veltkamp

SummaryThe influence of the thyroid function on the metabolic rate of prothrombin, factor VII, and X was studied in the rat. Disappearance rates of the three coagulation factors were measured after synthesis had been blocked with appropriate doses of warfarin, and reappearance rates were assessed upon induction of synthesis by high doses of vitamin K1 injected into rats displaying coumarin induced hypocoagulability.No statistically significant difference in the disappearance and production rates of any of the factors could be found between normal euthyroid rats and thyroxin-treated hypothyroid rats proven to be euthyroid. The differences between the two euthyroid groups and the hypothyroid group were highly significant, however: hypothyroidism results in an approximately 50% decrease of the metabolic rates of the three coagulation factors under study.The reappearance of the three factors, under euthyroid as well as hypothyroid conditions, showed a biphasic pattern: in the first two hours after vitamin K1 administration to warfarin treated rats, a rapid reappearance was observed, to the same extent for all three factors, in hypo- as well as euthyroid rats. This finding suggests that in vitamin K1 deficiency an intracellular accumulation of precursor proteins (PIVKAs) occurs, which after rapid conversion into biologically active coagulation factors by vitamin K1 are shed into circulation.The subsequent phase of reappearance is much slower and reflects the synthesis rate of coagulation enzymes. It is characteristic for each factor and clearly slower in hypothyroid rats than in euthyroid rats. From this an influence of thyroid function on the synthesis rate of the protein moiety of coagulation factors can be inferred.An apparent difference between disappearance and reappearance rate of the coagulation factors in the plasma, particularly pronounced for factors VII and X in euthyroid rats, could theoretically be explained as the consequence of the model used for derivation of these rates.


1960 ◽  
Vol 4 (01) ◽  
pp. 001-016
Author(s):  
Jessica H. Lewis ◽  
Paul Didisheim ◽  
John H. Ferguson ◽  
Kenichi Hattori

SummaryNormal whole blood was allowed to stand in glass tubes at 37° C, and the clotting process stopped at various intervals by the addition of sodium oxalate. During the first 15 minutes a marked acceleration of clotting activity was found. Study of the individual coagulation factors showed the following changes: a sustained and rapid fall in platelet count, a sustained and rapid rise in PTC (factor IX), a steady fall in fibrinogen, a more gradual fall in AHF (factor VIII), a rapid rise and subsequent fall in proaccelerin (factor V) activity, a somewhat lesser and slower rise and fall in proconvertin (factor VII) activity, and a slow fall in prothrombin concentration. No changes were noted in Hageman factor or PTA activities.


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