Kinetic Aspects of the Interaction of Blood Clotting Enzymes

1968 ◽  
Vol 19 (03/04) ◽  
pp. 346-363 ◽  
Author(s):  
H. C Hemker ◽  
J. J Veltkamp ◽  
E. A Loeliger

SummaryApplication of enzyme kinetics to the results of thrombotest estimations in correlation with specific clotting factor estimations has led to the recognition of a protein moiety that occurs in plasma in vitamin K deficiency and acts as a competitive inhibitor of thrombin formation. A hypothesis is given by which the occurrence of this inhibitor is explained in terms of a biphasic synthesis of the vitamin K-dependent clotting factors.

1968 ◽  
Vol 20 (01/02) ◽  
pp. 078-087 ◽  
Author(s):  
H. C Hemker ◽  
A. D Muller

SummaryPIVKA, the circulating anticoagulant protein found in vitamin K deficiency can, on kinetical grounds, be recognized as an analogue of factor X. The existence of analogues of other vitamin K-dependent clotting factors cannot be ruled out, but need not be assumed to explain the experimental results.


2018 ◽  
Vol 9 (1) ◽  
pp. 44
Author(s):  
Mutia Felina ◽  
Marlina Marlina

Vitamin K is a fat-soluble vitamin that has an important role in activating substances that play a role in blood clotting, including substances known as prothrombin and clotting factors. The purpose of this research is to know the knowledge factor of midwife toward vitamin K in the newborn with midwifery in the prevention of vitamin K deficiency in the newborn in Bukitinggi city. This type of research is cross-sectional, and this research is done in Bukittinggi City Year 2017. Sampling technique with Random Sampling or randomly. The research will be carried out in the Working Area of Bukittinggi City in 2017. The population and sample in this study are all midwives who have BPM in Bukittinggi City with a sample size of 21 midwives. Data analysis with chi-square showed that there was no correlation between midwife knowledge on vitamin K administration in BBL with the working period and availability of midwife in preventing vitamin K deficiency on BBL with p = 0,0001 (p> 0,05). It is recommended for health workers in Kota Bukittinggi to improve the standard services of Midwifery, especially to newborns.


Author(s):  
Sir Peter Gluckman ◽  
Mark Hanson ◽  
Chong Yap Seng ◽  
Anne Bardsley

Vitamin K is involved in blood clotting, and lack of this nutrient results in a hypocoagulable state, associated with a high risk of bleeding events. Deficiency is rare among adults, because vitamin K is widely available in foods. However, the placenta transmits vitamin K relatively poorly, leading to a general deficiency in full-term neonates, who are also particularly vulnerable to the effects of low vitamin K levels because of their immature clotting systems. Deficiency can lead to intracranial haemorrhage following birth trauma, or classic vitamin K deficiency bleeding. It is important to maintain adequate vitamin K status throughout pregnancy in order to avoid added risk to the neonate at birth and in the first few weeks of life. Supplementation of newborns by intramuscular injection should be universal.


PEDIATRICS ◽  
1970 ◽  
Vol 45 (5) ◽  
pp. 857-861
Author(s):  
Ordean L. Torstenson ◽  
G. Bennett Humphrey ◽  
J. Roger Edson ◽  
Warren J. Warwick

Three patients are discussed who presented with hemorrhagic diatheses who were subsequently diagnosed as having cystic fibrosis. Their prolonged prothrombin times and low levels of vitamin K-dependent clotting factors were due to vitamin K deficiency. In two patients we believe that the vitamin K deficiency was principally due to malabsorption caused by cystic fibrosis. In the third patient, malabsorption, diarrhea, antibiotic therapy, and low dietary intake all played a part in the development of vitamin K deficiency. Cystic fibrosis should be included in the differential diagnosis of patients under 1 year of age presenting with a bleeding tendency.


Author(s):  
Jennifer T. Truong ◽  
Sarah L. Booth

Vitamin K is traditionally recognized for its role in blood clotting. More recently, new roles for vitamin K have emerged. The current evidence for the role of vitamin K in bone, cardiovascular, and reproductive health will be discussed. There will be a particular focus on populations who could be at risk for vitamin K deficiency.


1993 ◽  
Vol 69 (04) ◽  
pp. 328-330
Author(s):  
D V Shah ◽  
J A Engelke ◽  
J W Suttie

SummaryBased on studies in intact animals, the presence of humoral factors, “coagulopoietins”, which regulate the synthesis of vitamin K-dependent plasma proteins has been proposed. These proposed factors are produced in response to vitamin K deficiency, coumarin treatment, or specific antibody depletion of vitamin K-dependent clotting factors. The production of pro-thrombin by rat hepatoma H4IIEC3 cells has now been shown to be dependent on the source of bovine serum in the media. Cells grown in serum from cows treated with dicoumarol produce about 20% more prothrombin in 24 h than those cells grown in control serum. The humoral factor causing this response is present early in the course of dicoumarol treatment, and the increase in prothrombin production is dependent on the amount of serum from a dicoumarol-treated cow in the media. Based on membrane filtration studies, the factor appears to be associated with the protein fraction of serum.


1980 ◽  
Vol 44 (03) ◽  
pp. 159-160 ◽  
Author(s):  
R G Malia ◽  
F E Preston ◽  
V E Mitchell

SummaryUmbilical cord plasmas from 24 normal full-term neonates were studied. We confirmed the prolonged prothrombin time and low levels of Vitamin K dependent clotting factors previously described (1), but using a number of recently developed immunological and coagulation techniques we could find no evidence of vitamin K deficiency. We conclude that the decreased levels of vitamin K dependent clotting factors of normal neonates are the result of decreased synthesis by the immature liver and that it is questionable whether vitamin K prophylaxis is necessary for these infants.


1977 ◽  
Author(s):  
R.G. Malia ◽  
F.E. Preston ◽  
E.K. Blackburn

Vitamin K deficiency is associated with low procoagulant activity of the vitamin K-dependent clotting factors together with normal concentrations of an immunologically cross-reacting protein associated with the appropriate clotting factor.In this study we have examined the response of the clotting factors II, VII and X together with their appropriate related antigens to the intravenous administration of vitamin K1 in 14 patients with various forms of liver disease. We have also related the observed changes to alterations of the inhibitor activity of PIVKA as detected by the modified thrombotest.A relationship has been established between the rate of appearance of procoagulant activity and the rate of disappearance of PIVKA after the intravenous administration of vitamin K1 in those patients with thrombotest inhibitor activity. In this same group of patients it can also be shown that PIVKA is physico-chemically dissimilar to the related protein of normal individuals.Patients without thrombotest inhibitor activity appear to synthesise decreased amounts of a structurally normal protein which is not influenced by vitamin K.


Author(s):  
Dina Simes ◽  
Carla Viegas ◽  
Nuna Araújo ◽  
Catarina Marreiros

Abstract Vitamin K has been recognized as a key factor for the synthesis of blood clotting factors in the liver, and is currently known to be involved in a wide range of biological processes and is associated with many pathological conditions.The most well-known function of vitamin K is as a cofactor for the γ-glutamyl carboxylase (GGCX) enzyme responsible for the post-translational modification of vitamin K-dependent proteins (VKDPs) through the conversion of specific glutamic acid (Glu) into calcium binding γ-carboxyglutamic acid (Gla) residues. Vitamin K deficiency has been linked to several pathological conditions such as cardiovascular diseases (CVD), chronic kidney disease (CKD), osteoarthritis (OA) , rheumatoid arthritis (RA), osteoporosis, cancer, dementia, certain skin pathologies, functional decline, and disability.  A new concept on the involvement of vitamin K in inflammation is growing. In fact, novel roles have been disclosed for vitamin K independent of its activity as a cofactor for GGCX, such as an antioxidant, anti-inflammatory, promoter of cognition, inhibition of tumor progression, and transcriptional regulator of osteoblastic genes. A growing number of studies has raised an increasing interest on the use of vitamin K as a health promoting supplement.  Aging societies represent a major economic challenge for health care systems, and diet supplements promoting healthy aging and improving the prognosis of age-related diseases, are required to be implemented in clinical practice.This work thoroughly reviews available data regarding differences between vitamin K1 and K2, contextualized with clinical aspects of vitamin K deficiency, including their sources, functions, target activity, and involvement in age-related diseases. Processes for the chemical and biological production of vitamin K1 and K2 will be briefly addressed. Additionally, novel sources with potential biotechnological application, and new formulations to improve vitamin K absorption and bioavailability are presented.


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