Interactions among indicators of B1, B2, B6 and vitamin C status in university students

In 209 young university students (109 males and 80 females) with body mass index within the normal range, the activation coefficient of the erythrocyte transketolase (ETKAC) glutathione reductase (EGRAC) and aspartate amino transferase (EASTAC) as well as the circulating levels of vitamin C were determined. Using the usual cutoff points for ETKAC and serum vitamin C and higher than usual cutoff points for EASTAC and EGRAC 99, 95, 92, and 87 per cent of the study subjects exhibited activation coefficients which were compatible with an acceptable status for vitamin B2, B6, C and B1 respectively. A correlation analysis showed a high correlation (r = 0.81) between erythrocyte indicators of B1 and B2 status a lower correlation between indicators of the status of these vitamins and B6 and no correlation between the indicators of B1, B2, and B6 status and serum vitamin C. This study indicated that in this largely nutritionally adequate population, the activation coefficient of the erythrocyte enzymes used here as markers of the nutritional status of B1, B2, and B6 were related between themselves and varied in the same direction. These changes, however, were not associated with circulating levels of vitamin C.

Thiamin and riboflavin status of medical inpatients.

Thiamin status was assessed by erythrocyte transketolase activity (ETKA) and thiamin pyrophosphate effect (TPPE) and riboflavin status by erythrocyte glutathione reductase activity (EGRA) and activity coefficient (AC) in 165 medical inpatients in Ramathibodi Hospital. Based on TPPE > 15 per cent, 9 per cent of the medical inpatients had thiamin depletion. Most of them were patients with renal, cardiovascular, hematological and infectious diseases. Based on AC > or = 1.2, 17 per cent of these inpatients had riboflavin depletion. Most of them were patients with pulmonary, cardiovascular and hematological diseases. Only one patient with pulmonary disease had both thiamin and riboflavin depletion. The proportion of thiamin depletion (2/37) in subjects with thiamin supplementation (mean 32.4, median 6, mode 2 md/d) tended to be less than those without (9/98). But, subjects with riboflavin supplementation (mean 3.3, median 4, mode 1 md/d) had the proportion of riboflavin depletion (0/31) significantly (Z-test, p < 0.005) lower than without supplementation (23/104). The data suggested that although the usual dose of vitamin supplementation in medical inpatients is beneficial thiamin depletion can still be present in catabolic patients.

isolation of enzyme transketolase from human erythrocytes: the characterization of its quaternary structure

Human erythrocyte transketolase [sedoheptulose-7-phosphate: D-glyceraldehyde-3-phosphate, glycolaldehyde transferase, E. C. 2.2.1.1.] has been isolated from erythrocytes with a specific activity of 59.84 U/mg. SDS-PAGE and SE-.HPLC were used both as a measure of purity and as a preparative mean to obtain a higher degree of purity. Four protein bands corresponding to molecular weights of 32,000, 39,000, 43,000 and 60,000 were obtained in electrophoresis and SE-HPLC preparations. Activity measurements on the two fractions obtained from SE-HPLC that contained a monomer with the molecular weight of 32,000 and a dimeric fraction with the molecular weight of 60,000 showed that the monomeric form of the enzyme displays activity in the presence and absence of the TPP and Mg[II]. This activity was measured to be 14.76 U/mg in the absence of TPP and Mg[II], and 40.24 U/mg in the presence of the cofactors. The dimeric form showed an activity of 58.84 U/mg in the presence of the cofactors

The vitamin B1, B2 and B6 status of school children in two resettlement areas in Northeast Thailand.

The vitamin B1, B2 and B6 status of school children were studied in the Khon Kaen resettlement and irrigation area and in the Lam-takong settlement in northease Thailand using the in vitro tests based on the erythrocyte transketolase, glutathione reductase and glutamate-oxaloacetate transaminase activities. Healthy school children from the Khon Kaen University School were selected as a reference group. The results demonstrate that the vitamin B1 status in the resettlement area is sufficient, but about 20% to 35% of all the children show evidence of vitamin B2 and B6 deficiencies. It is noticed that besides a high prevalence of parasitic infections and poor hygienic conditions the protein and vitamin intake is low and improvement of the situation is necessary.