Pitney, Beard, and Van Loon (2) and Ostrowski, Skarzynski, and Zak (3) reported in 1954 that vitamin B12 is bound primarily to a-globulin in normal serum. Pitney and his colleagues (2) also noted that p-globulin can bind B12 added in vitro, but they considered this as "free B12" because, unlike B12 bound to a-globulin, Euglena gracilis is able to utilize it without prior heat treatment. Miller ...

5. Isbister GK, Gray MR. White-tail spider bite: a prospective study of 130 definite bites by Lampona species. 'Mobile phone sign' in early vitamin B12 deficiency Sir, I greatly enjoyed the letter from Kozak and Schattner regarding 'Mobile Phone Sign' in early vitamin B12 deficiency. 1 I would, however, like to make one comment. I note that the patient reported in the letter was treated (succes...

Two strains of Lactobacillus leichmanii, ATCC 7830 and ATCC 4797, are generally used for vitamin B12 assay. However, the complex growth requirements and the lack of specificity to vitamin B12 of these lactic acid bacteria make the determination of vitamin B12 difficult (Hoffmann et al., 1948; Skeggs et al., 1948; Snell et al., 1948; Capps et al., 1949; Kitay et al., 1949; Peeler et al., 1949; W...

PURPOSE Infant formula is based on cow's milk and designed to mimic breast milk for substitution. Vitamin B12 (B12) is bound to proteins in both breast milk and cow's milk, and in milk from both species the vitamin occurs mainly in its natural form such as hydroxo-B12 with little or no synthetic B12 (cyano-B12). Here we test commercially available infant formulas. METHODS Eleven commercially ...

The normal human granulocyte vitamin B12-binding protein, transcobalamin I, and transcobalamin III, have been labeled with 125I-labeled N-succinimidyl 3-(4-hydroxyphenyl)propionate and utilized for plasma clearance studies performed with rabbits. Both moieties of 125I-labeled granulocyte vitamin B12-binding protein-[57Co]vitamin B12 were cleared rapidly from the plasma (is less than 90% by 5 mi...

AIMS/HYPOTHESIS Patients treated with metformin exhibit low levels of plasma vitamin B12 (B12), and are considered at risk for developing B12 deficiency. In this study, we investigated the effect of metformin treatment on B12 uptake and distribution in rats. METHODS Sprague Dawley rats (n = 18) were divided into two groups and given daily subcutaneous injections with metformin or saline (cont...

Vitamin B12 is an enzymatic cofactor that essential for both eukaryotes and prokaryotes. The development of life in extreme environments depends on cofactors such as vitamin well. genomes twelve microorganisms isolated from the deep subsurface Iberian Pyrite Belt have been analyzed search activities require or are involved its synthesis import. Results revealed needed by these several enzymes r...

BACKGROUND Inflammatory bowel disease (IBD) patients may be at risk of vitamin B12 and folate insufficiencies, as these micronutrients are absorbed in the small intestine, which is affected by IBD. However, a consensus has not been reached on the association between IBD and serum folate and vitamin B12 concentrations. METHODS In this study, a comprehensive search of multiple databases was per...

Salmonella enterica serovar Typhimurium synthesizes cobalamin (vitamin B12) only during anaerobiosis. Two percent of the S. Typhimurium genome is devoted to the synthesis and uptake of vitamin B12 and to B12-dependent reactions. To understand the requirement for cobalamin synthesis better, we constructed mutants of Salmonella serovars Enteritidis and Pullorum that are double-defective in cobala...

OBJECTIVE To investigate the interrelations of serum vitamin B12 markers with brain volumes, cerebral infarcts, and performance in different cognitive domains in a biracial population sample cross-sectionally. METHODS In 121 community-dwelling participants of the Chicago Health and Aging Project, serum markers of vitamin B12 status were related to summary measures of neuropsychological tests ...