Thiamine transport by the red blood cells of rats was investigated at a physiological concentration of thiamine. The transport rate became large in accordance with the decrease of the initial thiamine concentra tion in the medium. Pyrithiamine and chloroethylthiamine inhibited this transport but oxythiamine did not. The examination of counter flow showed that thiamine efflux from the red blood ...

A modified sporulation medium for Clostridium perfringens was formulated in which a larger number of spores were produced than in SEC broth and in which spores of greater heat resistance were produced than in Ellner's medium when it was also used as the suspending medium. This modified medium consisted of 1.5% peptone; 3.0% Trypticase; 0.4% starch; 0.5% NaCl; and 0.02% MgSO(4). The addition of ...

We have investigated the cellular pathology of the syndrome called thiamine-responsive megaloblastic anemia (TRMA) with diabetes and deafness. Cultured diploid fibroblasts were grown in thiamine-free medium and dialyzed serum. Normal fibroblasts survived indefinitely without supplemental thiamine, whereas patient cells died in 5-14 days (mean 9.5 days), and heterozygous cells survived for more ...

The rapid improvement in the clinical manifestations of thiamine deficiency with thiamine supplementation is well known. To study this process in more detail, we rendered rats thiamine deficient either by dietary deprivation alone (DD) or, in addition, by daily pyrithiamine administration (DD + PT). We observed the cerebral metabolic and histological responses of these rats after 1 or 7 days of...

The phosphorylated form of thiamine (Vitamin B1), thiamine pyrophosphate (TPP) is essential for the metabolism of amino acids and carbohydrates in all organisms. Plants and microorganisms, such as yeast, synthesize thiamine de novo whereas animals do not. The thiamine signal transduction (THI) pathway in Saccharomyces cerevisiae is well characterized. The ~10 genes required for thiamine biosynt...

The pathway of thiamine pyrophosphate (TPP) biosynthesis, which is formed either from exogeneously added thiamine or from the pyrimidine and thiazole moieties of thiamine, in Micrococcus denitrificans was investigated. The following indirect evidence shows that thiamine pyrophosphokinase (EC 2.7.6.2) catalyzes the synthesis of TPP from thiamine: (i) [35S]thiamine incubated with cells of this mi...

Thiamine is an essential component of the human diet and thiamine diphosphate-dependent enzymes play an important role in carbohydrate metabolism in all living cells. Although the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe can derive thiamine from biosynthesis, both are also able to take up thiamine from external sources, leading to the down-regulation of the enzymes involved...

Spores of three strains each of type A and type B Clostridium botulinum were produced both by a biphasic (solid medium overlaid with an aqueous phase) and by a "conventional" (deep broth culture) procedure. Sporogenesis by the biphasic system was more rapid, convenient, and economical, and yielded as many or more heat-resistant (80 C, 10 min) spores per milliliter as by the conventional techniq...

We identified a strain carrying a recessive constitutive mutation (thi80-1) with an altered thiamine transport system, thiamine-repressible acid phosphatase, and several enzymes of thiamine synthesis from 2-methyl-4-amino-5-hydroxymethylpyrimidine and 4-methyl-5-beta-hydroxyethylthiazole. The mutant shows markedly reduced activity of thiamine pyrophosphokinase (EC 2.7.6.2) and high resistance t...