Objective: Oral isotretinoin is the most effective agent in treatment of acne vulgaris. The risk pigmentation due to systemic may be associated with decrease serum levels Vit B12. study aims contribute literature by defining association between increase caused oral [O-ISO] use and low vitamin B12 level [vit-B12]. Methods: In our we evaluated 144 patients, who have facial acnes at medium degree ...

OBJECTIVE To assess the prevalence and clinical features of B12 deficiency in hypothyroid patients and to evaluate clinical response in symptoms to B12 replacement therapy. METHODS One hundred and sixteen hypothyroid patients from our endocrine clinic were evaluated for signs and symptoms of vitamin B12 deficiency. Laboratory parameters including Haemoglobin (Hb), MCV, Vitamin B12 levels and ...

Using comparative analysis of genes, operons, and regulatory elements, we describe the cobalamin (vitamin B12) biosynthetic pathway in available prokaryotic genomes. Here we found a highly conserved RNA secondary structure, the regulatory B12 element, which is widely distributed in the upstream regions of cobalamin biosynthetic/transport genes in eubacteria. In addition, the binding signal (CBL...

Isolated ileal enterocytes incubated with intrinsic factor-[57Co]vitamin B12 (IF-B12) at 37 degrees C took up 25 times more B12 than jejunal enterocytes. Uptake of B12 by ileal cells was dependent upon IF and Ca2+. B12 taken up by ileal enterocytes could be separated into two components: 1) B12 which was retained (E component) and 2) released (R-E component) by chelation of divalent cations. Th...

Only a small fraction of vitamin B12-requiring organisms are able to synthesize B12 de novo, making it a common commodity in microbial communities. Initially recognized as an enzyme cofactor of a few enzymes, recent studies have revealed additional B12-binding enzymes and regulatory roles for B12 Here we report the development and use of a B12-based chemical probe to identify B12-binding protei...

Vitamin B12 (cobalamin) deficiency is a major public health problem, particularly among the elderly population. It is known that a deficiency in serum B12 levels can cause a combination of neurological and psychiatric disorders. Therefore, in these cases successful replacement of depleted B12 levels is a necessity. Identification of B12 deficiency in elderly patients can be rather difficult as ...

Studies were designed to evaluate the binding of binding of vitamin B12 to cell membrane preparations from human placenta. The transcobalamin II-vitamin B12 complex (TCII-B12), which has a much greater affinity for the membranes than vitamin B12 alone, binds to a single saturable binding site with an approximate Ka = 7.2 mM-1. The binding requires a divalent cation and is temperature-dependent....

Vitamin B12 (cobalamin, Cbl, B12) is an indispensable water-soluble micronutrient that serves as a coenzyme for cytosolic methionine synthase (MS) and mitochondrial methylmalonyl-CoA mutase (MCM). Deficiency of Cbl, whether nutritional or due to inborn errors of Cbl metabolism, inactivate MS and MCM leading to the accumulation of homocysteine (Hcy) and methylmalonic acid (MMA), respectively. In...

OBJECTIVES to examine the prevalence of vitamin B12 deficiency and folate deficiency in later life in representative samples of the elderly population in the United Kingdom. DESIGN a population-based cross-sectional analysis of 3,511 people aged 65 years or older from three studies was used to estimate the age-specific prevalence of vitamin B12 deficiency and of folate deficiency. Vitamin B12...

BACKGROUND More than 2.9 million serum vitamin B12 tests were performed in 2010 in Ontario at a cost of $40 million. Vitamin B12 deficiency has been associated with a few neurocognitive disorders. OBJECTIVE To determine the clinical utility of B12 testing in patients with suspected dementia or cognitive decline. METHODS Three questions were addressed: Is there an association between vitamin...