We conducted three experiments to determine the effects of dietary thiamin supplementation on milk production by dairy cows. In trial 1, 28 Holstein cows were blocked by parity and assigned randomly to either placebo or thiamin top-dress for the 8-wk experiment to provide a supplemental thiamin intake of 0 or 150 mg/d per cow. Within each of these groups, cows were further assigned randomly to ...

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Purified bovine heart pyruvate dehydrogenase complex was used to investigate the effects of monovalent cations and cr-ketoisovalerate on pyruvate dehydrogenase (PDH) kinase inhibition by thiamin pyrophosphate. Initial velocity patterns for thiamin pyrophosphate inhibition were consistent with hyperbolic noncompetitive or hyperbolic uncompetitive inhibition at various K’ concentrations between 0...

Vitamin B1 (thiamin) is a cofactor for critical enzymatic processes and is scarce in surface oceans. Several eukaryotic marine algal species thought to rely on exogenous thiamin are now known to grow equally well on the precursor 4-amino-5-hydroxymethyl-2-methylpyrimidine (HMP), including the haptophyte Emiliania huxleyi Because the thiamin biosynthetic capacities of the diverse and ecologicall...

A thiamin-binding protein was isolated from sunflower seeds. Its molecular mass was estimated to be 230 kDa by gel filtration. The protein was suggested to be composed of six subunits, which consisted of polypeptides linked by disulfide bond(s). The protein contained a large amount of glutamine or glutamic acid (19.9 mol%) and asparagine or aspartic acid (11.1 mol%). The levels of tryptophan an...

novel data, which together served to define and explicate an understanding of the alcoholic Wernicke-Korsakoff Syndrome (WKS) from the clinical and basic science perspectives. The symposium's five presentations covered neuropathology, epidemiology, neural and genetic mechanisms, neuropsychological and neuroradiological signs of Wernicke's encephalopathy (WE) and Korsakoff's syndrome (KS), and t...

Thiamin is important for normal function of pancreatic acinar cells, but little is known about its mechanism of uptake and about the effect of chronic alcohol use on the process. We addressed these issues using freshly isolated rat primary and rat-derived cultured AR42J pancreatic acinar cells as models. Results showed thiamin uptake by both primary and cultured AR42J pancreatic acinar cells to...

Thiamine deficiency may present four classic clinical forms: peripheral polyneuropathy, anorexia and muscular weakness (dry beriberi); high output heart failure with signs of congestion (wet beriberi); beriberi associated with shock (Shoshin beriberi) and Wernicke's encephalopathy. In this report we describe a picture that is suggestive of severe pulmonary hypertension and cor pulmonale, with j...

This communication describes the development of a thiamin sensor based on the bacterial thiamin binding protein. A triple mutant (C48S, C50S, S62C) of TbpA was labeled on C62 with N-[2-(L-maleimidyl)ethyl]-7-(diethylamino)coumarin-3-carboxamide (MDCC). Thiamin binding to this protein reduced the coumarin fluorescence giving a thiamin sensor with low nanomolar sensitivity.