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The relative efficacy of thiamine supplementation to sheep by injection, subcutaneous implant and orally administered protected thiamine bolus was compared in two experiments using a grass and hay ration and a ration containing bracken rhizomes to induce thiamine deficiency. In both experiments, urinary excretion of thiamine was significantly higher in supplemented sheep than in the controls, and in sheep supplemented by injection than in sheep supplemented by implant or protected boluses. Thiamine excretion was lower in sheep fed the ration containing bracken rhizomes than in sheep fed the grass ration.

Thiamine propyl disulfide (TPD) was orally administered in patients with liver disease to measure the main metabolite, 2-hydroxypropyl methyl sulfone (2HPMS), in urine, for the test of liver function. The amount of urinary excretion of 2HPMS decreased in proportion to the degree of severity of liver disease, with intimate correlation with various tests reflecting hepatic reserve function (p less than 0.01). Phenobarbital (PB), one of the inducers of hepatic microsomal drug metabolizing enzymes scarcely influenced the results of this test. In patients with ordinary liver disease without remarkable disturbance of intestinal absorption and renal excretory function, this method appears to be clinically applicable.

Influence of the dietary supply in thiamine on the vitamin nutritional status of the gestating female rat and of the litter. Four groups of gestating female rats were fed diet containing respectively 2, 4, 6, 8 mg of thiamine par kg. In every group, urinary excretion of thiamine was found to be stable up to the 16th day of gestation and then to decrease markedly during the 5 last days. This result and those concerning the changes in vitamin excretion, as related to the dietary intake, support the hypothesis that thiamine requirement is strongly higher at the end of the gestating period. On the other hand, measurements of thiamine concentration in tissues show that, when thiamine is given in suboptimal quantity, it is priorly fixed by the foetus at the expense of the maternal organs particulary of the liver.

A sensitive, reproducible, and specific method for the determination of urinary thiamine has been established. Unique to the use of high-pressure liquid chromatography (HPLC) to separate the fluorescent thiamine derivative from interfering fluorescent compounds. Urine samples were passed through a Decalso catoin-exchange column, washed with 0.5 M KCl to remove some interfering compounds, and eluted with 3.4 M KCl. The eluted thiamine was converted to the fluorescent derivative, thiochrome, by reaction with alkaline potassium ferricyanide. The reaction mixture was extracted with isobutanol and subjected to HPLC monitored by a fluorescent detector. Within-day and day-to-day coefficients of variation proved to be 2.5% and 1.2% respectively. Recovery of added thiamine (range 0.04 to 2.0 microgram/ml) averaged 99.9 +/- 5.3%. The sensitivity of this method was 0.03 microgram/ml.

The rate of the production of thiazole, the first product of the reaction, catalyzed by thiaminase I (EC 2.5.1.2) from Anodonta cygnea muscles is characterized by an initial flash-up explained by a considerable difference in the rates of the enzyme-substrate complex formation and its further transformation. Basing on this phenomenon, a new method for measuring the total thiamine in vitro and in biological material has been developed. Optimal conditions for thiamine measurements in the blood and urine have been selected.

Ascorbic acid, thiamin, niacin, pyridoxine, and folic acid status was evaluated in eight physiologically stable home parenteral nutrition patients. Six of these subjects received these vitamins as a twice weekly bolus and were studied over a period of 6 days. All vitamin levels were normal except for blood thiamin which was low, 72 h after each bolus. Since transketolase levels remained normal, this fall in blood thiamin probably had no functional significance. The urine excretion pattern of niacin and pyridoxine indicated normal metabolism and retention of these vitamins. Two patients, who required only parenteral fluid and electrolytes to remain weight stable, received none of these vitamins parenterally, but also maintained adequate vitamin status. These results suggest that in long term home parenteral nutrition patients these five vitamins can safely be given twice weekly, rather than daily, and that short bowel patients who maintain their weight without intravenous calories and protein also assimilate adequate amounts of these proximally absorbed water soluble vitamins from their diet.

The effect of 5-fluorouracil on the thiamin status of normal female adult rats has been investigated. Pre-treatment of the animals with the cytotoxic drug daily for 3 successive days resulted in a significant decrease in hepatic concentrations of thiamin concomitant with a decrease in thiamin-dependent transketolase enzyme activity and an increase in thiamin-pyrophosphate-(TPP-)stimulating effect in whole blood when compared with those of pair-fed control animals. The TPP effect of transketolase enzyme activity was also increased by 5-fluorouracil in vitro. Furthermore, the treatment with 5-fluorouracil resulted in decreased liver and spleen concentrations without affecting the urinary excretory levels of thiamin in animals supplemented with large doses of the vitamin. Giving a dose comparable to a human therapeutic dose caused a similar increase in the TPP effect. These results indicate that treatment with 5-fluorouracil may be associated with thiamin deficiency by increasing either the utilization or the breakdown of thiamin.

The total dietary intake of energy and of individual nutrients of 99 grades 3 and 6 children from 10 greater Winnipeg shcools were generally comparable to those reported by Nutrition Canada for the Manitoba and national samples, although the percentile distributions of total caloric intake and dietary intake of vitamin A for the Winnipeg children tended to be lower. The median daily intake of protein was 212% of the Canadian Dietary Standard and most came from animal sources. Dietary fat was largely from animal sources as well. Hemoglobin concentrations were marginally low in four children, and urinary riboflavin:creatinine ratios were low in six children. There was no biochemical evidence of thiamin deficiency. The results suggest a need for change in dietary patterns and for education in nutrition, including relative nutrient/cost benefits. A well planned school snack program with an education component is a medium by which change could be introduced. This should preferable be part of a total school health program.

In order to investigate the metabolism of thiamine chloride ester monophosphate of bis-D-glucosamine (TCMPG) urinary excretion, blood levels and tissue content of thiamine in vitamin B1-deficient rats were measured after intraperitoneal injection of this compound or of thiamine monophosphate or of a mixture of thiamine monophosphate and glucosamine. The greater retention and the higher levels of vitamin observed in the blood and in the tissues of animals treated with TCMPG compared with the control rats confirm the hypothesis that a more efficient utilization of vitamin B1 is obtained by the organism when it is administered salified with glucosamine.

Aqueous solutions of thiamin hydrochloride were incubated with catechol for 24 hr, pH 7.4 at 50 degrees C. Additional solutions of thiamin and catechol were incubated separately. After incubation the remaining thiamin was analyzed by the thiochrome procedure which showed that the thiamin in the thiamin-catechol mixture was reduced by 82.5-90% and the thiamin incubated alone by 18-20%. The solutions were fed to groups of rats after they had been on a thiamin free diet for 17 days. Body weight gains, erythrocyte transketolase (ETKA), thiamin pyrophosphate effect (TPPE) and liver and urine thiamin were measured. The results of these experiments showed that given the thiamin-catechol mixture (after incubation at pH 7.4, 50 degrees C for 24 hr) produced thiamin deficiency according to ETKA and TPPE values indicating that the thiamin was unavailable in vivo as well as in vitro. However, rats given thiamin and catechol separately (even after incubated each) no thiamin deficiency was observed.

The thiamin status of early bronchial and breast carcinomas has been assessed using "thiamin pyrophosphate" (TPP) stimulating effect of transketolase enzyme activity. The TPP stimulating effect was found to be greater in a high proportion of the cancer patients than in normal subjects, suggesting that these patients may be at risk of thiamin deficiency. The urinary excretory level of thiamin was high in the cancer patients; it is, therefore, unlikely that the biochemical deficiency of the vitamin was due to lack of the vitamin intake. It is, however, possible that the cancer patients were unable to convert thiamin to thiamin pyrophosphate, the active form of the vitamin.

Nutriture of thiamine, riboflavin and folacin was assessed by two tests: thiamine (109 subjects) by the TPP effect of erythrocyte transketolase activity and urinary excretion of thiamine (mug/g creatinine); riboflavin (81 subjects) by the activation coefficient of erythrocyte glutathione reductase and excretion of riboflavin in urine (mug/g creatinine); and folacin (91 subjects) by estimation of folacin in red blood cells and in serum (ng/ml). The following correlation coefficients (r) were obtained: transketolase activity vs thiamine excretion: -0.33; glutathione reductase vs riboflavin excretion: -33; and red blood cell folacin vs serum folacin: 0.77. When "deficient" and "low" values were defined as "not acceptable" and compared with "acceptable" values, sensitivity of thiamine excretion was 54%, of riboflavin excretion 33% and of serum folacin level 90%. The respective value of specificity were 75%, 83% and 37%. Sensitivity of thiamine excretion and of serum folacin level, respectively, increased when stricter criteria of insufficiency were applied and assessment of "deficiency" of these vitamins rather than of "non-acceptability" was attempted.

A modified procedure for the determination of thiamin in human urine by the thiochrome fluorescent method was used to examine the effects of three oxidizing agents. Urinary thiamin values obtained with the use of HgCl2 as the oxidizing agent were lower than those found with the use of either BrCN or K3Fe(CN)6. This may be due to a difference in the reactivity of interfering compounds with the specific oxidizing agent used. Recovery values were acceptable for each of these three oxidizing agents, although BrCN appears to be slightly superior. In addition to the recovery values, the linear response for the thiamin standards used in this study supports the use of a smaller resin column for the pretreatment of urine samples; this was found to be more economical and convenient to use.

Young adult male subjects maintained on a metabolic ward were fed diets providing controlled intakes of thiamin and either 2800 or 3600 kcal. The higher level of calories was attained by an increased intake of carbohydrates. Constant weights were maintained by the subjects by adjusting daily activity and exercise schedules. Thiamin requirements were evaluated in terms of erythrocyte transketolase activity and urinary excretion of the vitamin. The results of the study revealed that a relationship exists between thiamin requirement and caloric intake and expenditure. Thus, when the calories being utilized were derived primarily from carbohydrate sources, the minimum adult male requirement for thiamin appeared to be 0.30 mg of thiamin per 1000 kcal. Urinary excretion of thiamin and erythrocyte transketolase activity appear to be reasonably reliable reflections of thiamin intakes and thiamin nutritional status. The use of these measurements in nutrition surveys appears justified. The microbiological assay (Lactobacillus viridescens) for measuring thiamin levels in urine samples appears to be a somewhat more sensitive but valid procedure as an alternate for the thiochrome method. Judged from the results of this study, the recommended intake for the adult human of 0.40 mg of thiamin per 1000 kcal by FAO/WHO and the recommended allowance of 0.5 mg per 1000 kcal by the Food and Nutrition Board of the NAS-NRC appear reasonable and amply allow for biological variations and other factors that may influence the requirement for this vitamin.

Biochemical evidence of thiamine deficiency was found in 58% of patients with chronic liver disease, the incidence being higher in alcoholic than in non-alcoholic patients. Daily supplementation with high doses of thiamine hydrochloride (200 mg/day) for one week restored levels of thiamine pyrophosphate (TPP), the active co-enzyme form of thiamine, to normal in all cases. Such supplementation also stimulated synthesis of the TPP dependent enzyme transketolase. Because of the essential role of TPP as a co-factor in intermediary metabolism, it is concluded that high doses of thiamine should be included in the routine nutritional management of patients with severe chronic liver disease.

To clarify the effect of ethanol on thiamine metabolism and activity of transketolase, a thiamine dependent enzyme, in vivo and in vitro experiments were carried out. For the in vivo experiment, rats were separated into four groups: Group 1, thiamine sufficient diet with no ethanol administered; group 2, thiamine sufficient diet and ethanol administered by stomach tube; group 3, thiamine deficient diet with no ethanol administered; group 4, thiamine deficient diet and ethanol administered. After three weeks, the rats were killed, then thiamine levels and the activity of transketolase were assayed. Thiamine concentration in brains and livers of ethanol fed rats were lower than that in control rats. Urinary thiamine was higher in ethanol administered rats than in controls. The increase in the liver transketolase activity by the in vitro addition of cocarboxylase (TPP effect) was higher in group 3 than in group 4 although original transketolase activity was lower in group 4. For the in vitro experiment, various amounts of ethanol or acetaldehyde were added to the supernatant of brain and liver of intact rats, and transketolase activity was determined. Inhibition by acetaldehyde to transketolas was about 10 times higher than that by ethanol.

Urine samples of 85 Thai pre-school children ages below 5 years were taken for thiamine determination related to creatinine. The thiamine status of these children investigated was found to be normal. No difference in the urinary thiamine levels was observed between male and female subjects.

Nine out of 24 patients with acute hepatocellular necrosis leading to fulminant hepatic failure showed biochemical evidence of thiamine deficiency early in the course of their illness, probably as a result of inadequate intake of the vitamin. This was corrected by twice daily administration of intravenous vitamin supplements containing thiamine hydrochloride (100 mg b.d.). These studies indicate that conversion of thiamine hydrochloride to its biologically active co-enzyme form, thiamine pyrophosphate, is possible even in the presence of severe acute hepatocellular necrosis, and it is suggested that supplements of the vitamin should be included in the routine management of patients with acute hepatic failure.

The nutritional status of more than 80% of adult Indians in three bands in a remote area of Quebec was studied during the summer of 1978 and the findings were compared with the results of the 1970 and 1972 Nutrition Canada national and Indian surveys in which the Indian participation rate was 30%. In the present study, hematocrit, serum iron, transferrin saturation, serum vitamin E, serum folic acid, and urine thiamin excretion patterns showed only minor differences from Nutrition Canada's national and Indian survey. Serum total protein values were slightly higher in Indians than in the national sample, consistent with previous findings. A higher percentage of subjects had low serum concentrations of vitamin A and ascorbic acid than in the previous Indian survey, but not to such a marked degree.

The development of vitamin B1 (thiamine) deficiency was investigated in 17 obese patients in the course of a 1000 calory diet or during total fasting for a fortnight. Compared with normal persons no changes of concentrations of total thiamine, TPP, and pyruvate in the blood; thiamine excretion in the urine, or activiation coefficient of the eryhrocyte transketolase (alphaETK) were observed during the reducing diet. However, during a fortnight's total fasting all values decreased significantly to those of thiamine deficiency. The thiamine pyrophosphate (TPP) levels in the blood dropped from the 1st to the 14th day, whereas the alphaETK rose accordingly and the pyruvate levels showed a delayed rise. Total thiamine content of the blood and thiamine excretion in the urine only showed significantly different values when comparing the 1st and the 14th day. There was no dependency of thiamine excretion on urinary output. Clinical symptoms of thiamine deficiency could be demonstrated in no case.