Red cell transketolase as an indicator of nutritional deficiency.

Twenty patients who had symptoms that were apparently neurotically functional are reported because they proved to have abnormal red cell transketolase activity. Although in many of the cases the etiology appeared to be associated with heavy consumption of "junk" foods, carbonated or sweet beverages, and candy, this was not so in all of them and the etiology in these cases remains obscure. The symptoms in all 20 patients could be correlated with those well documented in early beriberi and all were clinically improved by the administration of thiamin.

Transketolase activity in psychiatric patients.

The thiamine status of 42 physically healthy nonalcoholic psychiatric inpatients was evaluated by measuring transketolase activity in a hemolysate of their red blood cells, before and after addition of thiamine pyrophosphate to the hemolysate. Sixteen patients (38%) showed evidence of thiamine deficiency. Five of these patients had received thiamine-containing vitamins for a period of from 2 fo 47 days prior to testing, suggesting that poor nutrition may not fully account for the thiamine deficiency observed.

Effect of protein depletion and repletion on liver structures, nitrogen content and serum proteins.

The data presented in this paper demonstrate that a liver which has been severely damaged by protein malnutrition can be restored to normal composition, anatomy and functional capability by central venous feeding. An atypical serum protein electrophoretic pattern characterizes protein malnutrition. TPN repletion restores all of the protein fractions back to normal except for the gamma globulin levels.

Antioxidants reduce the mutagenic effect of malonaldehyde and beta-propiolactone. Part IX. Antioxidants and cancer.

Increasing concentrations of malonaldehyde and beta-propiolactone were increasingly mutagenic with 7 mutants of Salmonella typhimurium, 5 of which mutated bya frameshift mechanism and 2 of which mutated through base-pair substitution. The antioxidants vitamin C, vitamin E, selenium and butylated hydroxytoluene (BHT) at 3 logarithmic concentrations markedly reduced mutagenesis in those strains which mutated by frameshift mechanism.

Methods compared for determining zinc in serum by flame atomic absorption spectroscopy.

We compared two methods for determination of serum zinc by flame atomic absorption spectroscopy. The first involved 10-fold dilution of serum with water; the second, deproteinization of serum with trichloroacetic acid. Analytical recovery of Zn2+ added to serum averaged 99.

Malonaldehyde content of food.

Several types of commercially available food both cooked and uncooked were tested for the presence of the carcinogenic initiator and mutagen, malonaldehyde, which is a breakdown product of unsaturated fatty acids. The thiobarbituric acid derivative of malonaldehyde from meat extract was identified either by thin layer chromatography or by gas chromatography after silylation. Malonaldehyde was also identified directly by gas chromatography.

Antioxidants and cancer. Part VI. Selenium and age-adjusted human cancer mortality.

The possible epidemiologic relationship between selenium occurrence and cancer mortality was studied in cities and states located in areas with different levels of selenium bioavailability. Statistically significant differences were found in age-specific cancer death rates among states with high, medium, and low selenium levels. The death rates for specific types of cancer showed a larger difference in males than in females in the states with high selenium levels.

Carcinogen-induced chromosomal breakage decreased by antioxidants.

Blood leukocyte cultures were incubated with antioxidants and the carcinogens sodium cyclamate and 7,12-dimethylbenz(alpha)anthracene in different combinations. There were 17.4% more chromosomal breaks in the group of cells treated with dimethylbenzanthracene only than in the untreated controls.

Lysosomal enzyme changes in growing and regressing mammary tumours.

Rat mammary tumours induced by 7,12-dimethylbenz[a]anthracene can undergo repeated growth and regression during successive pregnancies. In a 10-day period after birth about half of the tumours regressed 50% or more. The concentrations of the lysosomal enzymes increased in regressing mammary tumours to the following multiples of the initial values: beta-glucuronidase, 7.