Vitamin B status in patients with chronic fatigue syndrome.
(9/735)
Some patients with chronic fatigue syndrome say they benefit from taking vitamin supplements. We assessed functional status for the B vitamins pyridoxine, riboflavin and thiamine in 12 vitamin-untreated CFS patients and in 18 healthy controls matched for age and sex. Vitamin-dependent activities--aspartate aminotransferase (AST) for pyridoxine, glutathione reductase (GTR) for riboflavin, transketolase (TK) for thiamine--were measured in erythrocyte haemolysates before and after in-vitro addition of the relevant vitamin. For all three enzymes basal activity (U/g Hb) was lower in CFS patients than in controls: AST 2.84 (SD 0.62) vs 4.61 (1.43), P < 0.001; GTR 6.13 (1.89) vs 7.42 (1.25), P < 0.04; TK 0.50 (0.13) vs 0.60 (0.07), P < 0.04. This was also true of activated values: AST 4.91 (0.54) vs 7.89 (2.11), P < 0.001; GTR 8.29 (1.60) vs 10.0 (1.80), P < 0.001; TK 0.56 (0.19) vs 0.66 (0.08), P < 0.07. The activation ratios, however, did not differ between the groups. These data provide preliminary evidence of reduced functional B vitamin status, particularly of pyridoxine, in CFS patients. (+info)
Biochemical evidence of thiamin deficiency in young Ghanian children.
(10/735)
Detailed biochemical studies for nutritional status were carried out on 146 Ghanaian children ages 6 months to 6 years over a 2-year period. Study children comprised three main groups: severe protein-calorie malnutrition; mild to moderate protein-calorie malnutrition and apparently healthy children. Erythrocyte transketolase activity and the percentage of erythrocyte transketolase pyrophosphate effect were also determined. In the first year of the study elevated percentage of transketolase pyrophosphate effect indicative of thiamin deficiency was found in all three of the above-mentioned groups, with the most widespread deficiency in the normal groups. In year 2, repeat studies of the severely malnourished group after 2 weeks of nutritional therapy with the administration of vitamin capsules, which included thiamin, resulted in the normalization of transketolase pyrophosphate effect. Apoenzyme activity was comparable in all groups studied. There were no obvious clinical signs of thiamin deficiency, although sensory testing was not performed. A relatively large number of children with high percentage of transketolase pyrosphosphate effect also had serum folic acid deficiency. This evidence of widespread biochemical thiamin deficiency is indicative of an at-risk population among young children for clinical thiamin deficiency. Further studies are needed to identify whether the problem is inadequate thiamin intake, destruction of thiamin by thiaminases or food preparation methods, or malabsorption of thiamin. (+info)
Association of bacteria and yeasts in hot springs.
(11/735)
The thermophilic bacterium Bacillus sp. strain TB-1 was isolated in association with the yeast Debaryomyces vanriji from hot springs at 46 degrees C. It was shown that TB-1 excreted thiamine into the culture broth, which not only promoted D. vanriji growth in mixed culture but also increased the maximal temperature for yeast growth. (+info)
Isolation and characterization of the gene conferring thiamine-inducible expression from Saccharomyces cerevisiae.
(12/735)
The production level of CPY in Saccharomyces cerevisiae KS58-2D/pCY303 was drastically decreased when thiamine was not added to the culture medium. We isolated and characterized the mutants that could produce CPY even though thiamine was absent from the medium. Using complementation screening in the mutants obtained, we isolated a gene that was involved in the thiamine-inducible expression, TIE1, which corresponded to the YDR325w ORF on chromosome IV. The predicted protein sequence of TIE1 did not have significant homology to proteins from public databases. The disruption of the TIE1 gene caused two phenotypes, increase of expression level in thiamine-free medium and ethanol sensitivity. This increase in thiamine-free medium was also observed in the expression under the control of ENO1 or ADH1 promoter in addition to the GAL10 promoter, suggesting that the TIE1 protein is associated with a similar kind of transcriptional mechanism regulated by thiamine. (+info)
Transport of thiamine in human intestine: mechanism and regulation in intestinal epithelial cell model Caco-2.
(13/735)
The present study examined the intestinal uptake of thiamine (vitamin B(1)) using the human-derived intestinal epithelial cells Caco-2 as an in vitro model system. Thiamine uptake was found to be 1) temperature and energy dependent and occurred with minimal metabolic alteration; 2) pH sensitive; 3) Na(+) independent; 4) saturable as a function of concentration with an apparent Michaelis-Menten constant of 3.18 +/- 0.56 microM and maximal velocity of 13.37 +/- 0.94 pmol. mg protein(-1). 3 min(-1); 5) inhibited by the thiamine structural analogs amprolium and oxythiamine, but not by unrelated organic cations tetraethylammonium, N-methylnicotinamide, and choline; and 6) inhibited in a competitive manner by amiloride with an inhibition constant of 0.2 mM. The role of specific protein kinase-mediated pathways in the regulation of thiamine uptake by Caco-2 cells was also examined using specific modulators of these pathways. The results showed possible involvement of a Ca(2+)/calmodulin (CaM)-mediated pathway in the regulation of thiamine uptake. No role for protein kinase C- and protein tyrosine kinase-mediated pathways in the regulation of thiamine uptake was evident. These results demonstrate the involvement of a carrier-mediated system for thiamine uptake by Caco-2 intestinal epithelial cells. This system is Na(+) independent and is different from the transport systems of organic cations. Furthermore, a CaM-mediated pathway appears to play a role in regulating thiamine uptake in these cells. (+info)
Treatment with thiamine hydrochloride and astaxanthine for the prevention of yolk-sac mortality in Baltic salmon fry (M74 syndrome).
(14/735)
Two practical methods are reported for treating feral Baltic salmon with thiamine hydrochloride against M74 syndrome (abnormally high yolk-sac fry mortality of the Baltic salmon). Both bathing of the yolk-sac fry in thiamine hydrochloride (1000 mg l-1, 1 h) and a single intraperitoneal injection given to the female brood fish (100 mg kg-1 fish) during the summer 3 mo before stripping were shown to elevate the whole body total thiamine concentration in the fry. Both treatments were also shown to be effective in preventing mortality due to M74 syndrome. The effect of bathing the yolk-sac fry was shown to be dose-dependent. The results support the view that there is a causal relationship between the thiamine status of the yolk-sac fry and M74 mortality. An intraperitoneal injection of astaxanthine suspension administered to the female brood fish (11 mg kg-1 fish) in the summer 3 mo before stripping elevated the astaxanthine concentration in the eggs but did not affect mortality due to M74 syndrome. An interaction between astaxanthine and thiamine may occur in the developing embryo or yolk-sac fry, however. No association could be demonstrated between the various thiamine hydrochloride treatment practices and hepatic cytochrome P450 dependent 7-ethoxyresorufin-O-deethylase (EROD) activity in the yolk-sac fry. An injection of thiamine hydrochloride into the peritoneal cavity of wild Baltic salmon females could be used to raise thiamine concentrations in their offspring in the rivers. The effect on smolt production in Finnish Baltic salmon rivers needs to be investigated further, however. (+info)
Cytochemical studies on golgi apparatus, GERL, and lysosomes in neurons of dorsal root ganglia in mice.
(15/735)
Cytochemically demonstrable thiamine pyrophosphatase activity is present in the innermost Golgi element in both small and large neurons of the dorsal root ganglia in CF1, C57 black, and C57 beige mice, thus resembling the neurons of rat dorsal root ganglia. The localization of acid phosphatase (EC 3.1.3.2) activity in the large neurons of dorsal root ganglia in these mice is also similar to that in rats; it is not demonstrable in Golgi elements but is present in GERL and in three types of lysosomes apparently derived from GERL. However, the small neurons of the mouse differ from those of the rat in showing acid phosphatase activity in all elements of the Golgi apparatus. In the mouse neurons the acid phosphatase activity of residual bodies is "latent," i.e., it is not demonstrable in well-preserved cells. (+info)
Thiamin and pyridoxine requirements during intravenous hyperalimentation.
(16/735)
Studies were undertaken to determine rational dosages of vitamin B1 and B6 during long-term intravenous hyperalimentation, using more sensitive techniques than formerly used to evaluate B1 and B6 status. A standard vitamin combination, type A, (usually commercially available products) has been used up to now because of convenience, disregarding the effects of long-term administration. This combination lacks biotin, folic acid, and vitamin E and contains from 10 to 100 times the dietary allowances of such vitamins as B1, B2, B6, B12, and C. In response to the possibility of vitamin overdose, two new vitamin combinations, type B (from commercial products) and type C (a convenient and easily administered combination produced at the hospital) were developed in order to provide the normal dietary allowances and at the same time eliminate any harmful side-effects. From the results obtained, 5 mg/day for thiamin HCl and 3 mg/day for pyridoxine HCl in type B and type C were found to be a sufficient and safe level as opposed to 55 mg/day for thiamin HCl and 102 mg/day for pyridoxine HCl in type A. (+info)