Search results for "vitamin K"
showing 10 items of 108 documents
The Role of Vitamin K in Bone Remodeling and Osteoporosis
2012
Vitamin K is an essential fat soluble vitamin involved in the regulation of normal coagulation. However, growing evidence highlights that this molecule appears to be also implicated in the regulation of other important biological functions such as bone mineralization, calcium homeostasis, apoptosis, cell growth and signal transduction. In particular, many studies have focused their attention on the protective effects of vitamin K on bone tissue in the outlook of its use in the prevention and treatment of osteoporosis in post-menopausal women. The objective of the present paper is to review data of the literature regarding the metabolic effects of Vitamin K in bone tissue and its clinical ro…
Optimal duration of low molecular weight heparin for the treatment of cancer-related deep vein thrombosis. The ”CANCER DACUS” study
2014
Purpose We evaluated the role of residual vein thrombosis (RVT) to assess the optimal duration of anticoagulants in patients with cancer who have deep vein thrombosis (DVT) of the lower limbs. Patients and Methods Patients with active cancer and a first episode of DVT treated with low molecular weight heparin (LMWH) for 6 months were eligible. Patients were managed according to RVT findings: those with RVT were randomly assigned to continue LMWH for an additional 6 months (group A1) or to discontinue it (group A2), and patients without RVT stopped LMWH (group B). The primary end point was recurrent venous thromboembolism (VTE) during the 1 year after disconinuation of LMWH, and the secondar…
Menaquinone-dependent succinate dehydrogenase of bacteria catalyzes reversed electron transport driven by the proton potential.
1998
Succinate dehydrogenases from bacteria and archaea using menaquinone (MK) as an electron acceptor (succinate/menaquinone oxidoreductases) contain, or are predicted to contain, two heme-B groups in the membrane-anchoring protein(s), located close to opposite sides of the membrane. All succinate/ubiquinone oxidoreductases, however, contain only one heme-B molecule. In Bacillus subtilis and other bacteria that use MK as the respiratory quinone, the succinate oxidase activity (succinate-->O2), and the succinate/menaquinone oxidoreductase activity were specifically inhibited by uncoupler (CCCP, carbonyl cyanide m-chlorophenylhydrazone) or by agents dissipating the membrane potential (valinomycin…
Vitamin K deficiency bleeding leading to a diagnosis of Crohn’s Disease
2014
We report the case of a 45 year old man who came to Emergency Room of Polyclinic for sudden onset of localized ecchymosis and widespread hematomas. He was subjected to blood count and first level investigations to assess coagulation. Based on the results, second level investigations were performed. Endoscopy of the gastrointestinal tract with histological examination revealed a diagnosis of Crohn's disease. Vitamin K deficiency causes the formation of vitamin K-dependent clotting factors that cannot perform their pro-coagulant action. Consequently, patients present with hemorrhagic manifestations. Clinical and laboratory features observed in this patient show that the deficiency of vitamin …
Rhodoluna lacicola gen. nov., sp. nov., a planktonic freshwater bacterium with stream-lined genome
2014
A pure culture of an actinobacterium previously described as 'Candidatus Rhodoluna lacicola' strain MWH-Ta8 was established and deposited in two public culture collections. Strain MWH-Ta8(T) represents a free-living planktonic freshwater bacterium obtained from hypertrophic Meiliang Bay, Lake Taihu, PR China. The strain was characterized by phylogenetic and taxonomic investigations, as well as by determination of its complete genome sequence. Strain MWH-Ta8(T) is noticeable due to its unusually low values of cell size (0.05 µm(3)), genome size (1.43 Mbp), and DNA G+C content (51.5 mol%). Phylogenetic analyses based on 16S rRNA gene and RpoB sequences suggested that strain MWH-Ta8(T) is affi…
Canibacter oris gen. nov., sp. nov., isolated from an infected human wound.
2014
A facultatively anaerobic, Gram-reaction-positive, catalase- and oxidase-negative, rod-shaped bacterium isolated from an infected human wound caused by a dog bite was characterized by phenotypic and molecular genetic methods. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain IMMIB Q2029717T was a member of the order Micrococcales of the class Actinobacteria , displaying 91.6 % to 96 % sequence similarity with members of the family Microbacteriaceae . Phylogentic trees generated by different algorithms indicated that the strain forms an independent phylogenetic line of descent that consistently clustered proximal to the base of the genus Leucobacter . Chemical studies…
Mucilaginibacter frigoritolerans sp. nov., Mucilaginibacter lappiensis sp. nov. and Mucilaginibacter mallensis sp. nov., isolated from soil and liche…
2010
Five cold-adapted bacteria belonging to the genus Mucilaginibacter were isolated from lichen and soil samples collected from Finnish Lapland and investigated in detail by phenotypic and phylogenetic analyses. Based on 16S rRNA gene phylogeny, the novel strains represent three new branches within the genus Mucilaginibacter. The strains were aerobic, chemo-organotrophic, non-motile rods and formed pigmented, smooth, mucoid colonies on solid media. The strains grew between 0 and 33 °C (optimum growth at 25 °C) and at pH 4.5–8.0 (optimum growth at pH 6.0). The main cellular fatty acids were iso-C15 : 0, summed feature 3 (C16 : 1 ω7c/iso-C15 : 0 2-OH) and iso-C17 : 0 3-OH and the major respirato…
Euzebyella saccharophila gen. nov., sp. nov., a marine bacterium of the family Flavobacteriaceae.
2010
Strain 7SM30T , an aerobic marine, Gram-negative, heterotrophic and yellow- to orange-pigmented bacterium isolated from seawater from Castellón, Spain, was characterized using a polyphasic approach. Analysis of the 16S rRNA gene sequence showed that the isolate represented a novel lineage within the family Flavobacteriaceae. The most closely related genera were Pseudozobellia, Zobellia and Kriegella. Cells of strain 7SM30T were non-motile rods that required sea salts for growth, used a wide variety of carbohydrates as sole carbon and energy sources and, unlike species of the genera Pseudozobellia and Zobellia, did not possess flexirubin-type pigment or hydrolyse agar. Strain 7SM30T containe…
Experimental conditions affect the site of tetrazolium violet reduction in the electron transport chain of Lactococcus lactis
2009
The reduction of tetrazolium salts to coloured formazans is often used as an indicator of cell metabolism during microbiology studies, although the reduction mechanisms have never clearly been established in bacteria. The objective of the present study was to identify the reduction mechanisms of tetrazolium violet (TV) in Lactococcus lactis using a mutagenesis approach, under two experimental conditions generally applied in microbiology: a plate test with growing cells, and a liquid test with non-growing (resting) cells. The results showed that in both tests, TV reduction resulted from electron transfer from an intracellular donor (mainly NADH) to TV via the electron transport chain (ETC), …
Seasonal diet-based resistance to anticoagulant rodenticides in the fossorial water vole (Arvicola amphibius)
2021
International audience; Anticoagulant rodenticides (AR) resistance has been defined as "a major loss of efficacy due to the presence of a strain of rodent with a heritable and commensurately reduced sensitivity to the anticoagulant". The mechanism that supports this resistance has been identified as based on mutations in the Vkorc1 gene leading to severe resistance in rats and mice. This study evaluates the validity of this definition in the fossorial water vole and explores the possibility of a non-genetic diet-based resistance in a strict herbivorous rodent species. Genetic support was explored by sequencing the Vkorc1 gene and the diet-based resistance was explored by the dosing of vitam…