Erythrocyte glutamic-pyruvic transaminase (EGPT) and glutamic-oxaloacetic transaminase (EGOT) activities reflect vitamin B₆ status in humans (Baysal, Johnson, and Linkswiler, 1966). Pyridoxal phosphate (PALPO), an active form of vitamin B₆, serves as the coenzyme for these transaminases. Compared to other methods of vitamin B₆ assessment, transaminase measurement has the advantage of dealing with a single enzyme requiring PALPO and reflecting the subject's vitamin B₆ status over a long period of time (Sauberlich et al., 1970). Although studies on transaminase activity in adults have been reported, information on EGPT and EGOT activities in children is not available. This study was undertaken to determine the activities of EGPT and EGOT in normal preschool, children. In addition, factors affecting transaminase activities were considered. The storage stability of EGPT and EGOT was also reported. Participating in this study were 109 subjects, aged from 21 to 126 months. The activities of EGPT and EGOT were expressed as μg pyruvate/mg hemoglobin (Hb)/hr and mg pyruvate/ ml red blood cells/hr. The basal activity indicates the level of holoenzyme. The stimulated activity with added in-vitro PALPO shows the level of holoenzyme plus apoenzyme. The percent stimulation represents the degree of saturation of apoenzyme with the coenzyme (Cavill and Jacobs, 1967). For EGPT, the basal activity and percent stimulation were 1.20 ± 0.44 μg pyruvate/mg Hb/hr and 11.70 ± 7.00 percent, respectively. Those of EGOT were 23.30 ± 5.77 μg pyruvate/ mg Hb/hr and 69.90 ± 23.3 percent. The two different ways of expressing basal activity of EGPT and EGOT were highly correlated with one another. A significant positive correlation was found between the basal activities of EGPT and EGOT (p < 0.01). However, the positive relationship between their corresponding percent stimulation was> not significant. The stimulated and basal activities for both EGPT and EGOT were closely correlated (p < 0.01), which indicated that the level of holoenzyme is largely dependent on the amount of-apoenzyme available. A significant inverse relationship (p < 0.01) existed between the basal activity and percent stimulation of EGOT, which meant that the high enzyme activity level is usually associated with a high degree of saturation of the apoenzyme with PALPO. The similar inverse relationship for EGPT was not statistically significant. In the subjects whose diet was supplemented with multivitamins containing pyridoxine, the transaminase activities appeared to be higher and the corresponding percent stimulation lower than in those receiving no supplementation. However, the difference was only significant for basal EGPT, using the Student's t test (p < 0.01). The subjects with high basal activities or low percent stimulation of EGPT or EGOT also tended to have higher plasma vitamin B₆ levels. But these relationships were not significant. As the age of the subjects increased, the basal and stimulated activities of both EGPT and EGOT declined, accompanied by the corresponding increase in percent stimulation. The correlations for basal and stimulated activities, as well as percent stimulation of EGOT, but not EGPT, with age were significant (p < 0.05). The differences in transaminase activities due to sex were not significant. But in general, the girls had a lower basal activity and a higher percent stimulation for both EGPT and EGOT than the boys. The average hemoglobin level of the subjects was 12.95 ± 0.77 g percent. The hemoglobin levels increased significantly with age (p < 0.01). Finally, experiments with two hemolysate samples showed that no loss of EGPT or EGOT activities occurred with freezing and storage within 13 days. / Graduation date: 1976

Thiamine deficiency has been reported to cause nerve degeneration in the peripheral nervous system and hemorrhage with associated cellular damage in the central nervous system (Prickett, 1934). Koedam (1958) observed convulsions in thiamine-deficient pigeons, but convulsions have only rarely been seen in rats (Gubler, 1961). Rats treated with the thiamine antagonist, pyrithiamine (PTh)* always develop ataxia and convulsions but these neurological symptoms have never been reported in those treated with oxythiamine (OTh), another thiamine antagonist (Gubler, 1961). Hosein, Chabrol, and Freedman (1966) concluded that neurological symptoms occur only when the brain thiamine content is diminished to 2.5%o r less of the normal values. This conclusion was supported by the work of others (DaCaro, tl ,al., 1956; and Cerecedo and Eich, 1955).

The discovery of a substance in rice polishings that was useful in preventing beriberi was first shown by Grijns and Vedder (Wuest, 1962). In 1926, Jansen and Donath (Wuest, 1962} crystallized this substance which was subsequently synthesized independently by Williams and Cline (1936} and Grewe (1936). This substance was named thiamine by Williams (1936) because of its structure having the vital thiazole ring and because it was an "essential amine."

The objective of this dissertation was to study the disposition and absorption of riboflavin and ascorbic acid in healthy male subjects as a function of age. Deficiencies of these vitamins have been found in the elderly and malabsorption is suspected in this population. Absorption of riboflavin was examined by administration of an oral dose of 200 mg of riboflavin-5'-phosphate (FMN) and disposition was studied following a 30 min constant rate IV infusion of FMN equivalent to 25 mg of riboflavin. Ascorbic acid absorption was examined by administration of a 5 g oral dose and disposition was studied following a 1 g IV dose. Test doses of these vitamins were administered to subjects ranging in age from 33 to 85 years. High performance liquid chromatographic assays were developed for the determination of riboflavin and ascorbic acid in plasma and urine. The method for riboflavin separated FMN and flavin adenine dinucleotide under isocratic conditions. Quantification of the three flavins was achieved by fluorescence detection. The assay system for ascrobic acid used a postcolumn reaction for the fluorometric detection of a dehydroascorbic acid derivative. This method used isoascorbic acid as the internal standard. Finally, similar specificity between a "methoxyaniline" colorimetric method and the chromatographic method was observed for the quantification of ascorbic acid in plasma and urine. Albumin plasma concentration and riboflavin protein binding were decreased with age (p < 0.05). The in vitro stability of ascorbic acid in whole blood and plasma decreased with age (p < 0.05, n = 17). The results of this study indicate no age-related alterations in parameters associated with the gastrointestinal absorption of these vitamins. Increased relative renal excretion of riboflavin with age may explain the deficiency of this vitamin. On the other hand, ascorbic acid deficiency with age may be explained by decreased stability of the vitamin in blood.

No presente trabalho analisou-se um total de 101 indivíduos, sendo 26 não infectados e 75 infectados pelo HIV e classificados de acordo com o Walter Reed Army Institute (28 pacientes WR 1, 31 pacientes WR 2 e 16 pacientes WR 3/4). 05 indivíduos infectados pelo HIV apresentaram, nos estágios iniciais, uma diminuição progressiva do peso corporal, dos níveis séricos de uréia, albumina, colesterol total, HOL colesterol e LOL colesterol. Já os níveis séricos de proteínas totais, globulinas, IgG, IgA, &#945;1 glicoproteína ácida, haptoglobina e as atividades enzimáticas da AST e da LD apresentaram elevação nos indivíduos infectados e em conseqüência da evolução da infecção. Os triglicérides demonstraram apenas tendência para aumento dos níveis séricos nos indivíduos estadiados como WR3/4. Os níveis de ferro sérico encontraram-se diminuídos nos indivíduos estadiados como WR 3/4, enquanto que a concentração de transferrina apresentou-se diminuída apenas no Grupo WR 2. Houve uma tendência para a elevação progressiva dos níveis médios de ferritina com a evolução da doença. Nenhuma alteração foi verificada nos níveis de proteína \"C\" reativa. A EC-SOO apresentou diminuição dos níveis de atividade nos indivíduos infectados pelo HIV, enquanto que em células mononucleares a SOD apresentou atividade diminuída nos indivíduos estadiados como WR 3/4. A GSH-Px não apresentou alteração de sua atividade em decorrência da infecção pelo HIV. Os níveis plasmáticos do &#945;-tocoferol e do ascorbato apresentaram tendência para diminuição, enquanto o &#946;-caroteno não apresentou alteração nos grupos estudados. Estes resultados sugerem que a haptoglobina, as globulinas e a IgA podem ser utilizadas para a avaliação da evolução da infecção pelo HIV. Por outro lado, os níveis dos constituintes do sistema de defesa antioxidante analisados indicam que os indivíduos soropositivos encontram-se menos protegidos contra a ação de espécies reativas de oxigênio, o que favoreceria a presença de um estresse oxidativo e a replicação viral. / A total number of 101 individuals, including 26 controls and 75 patients classified according to the Walter Reed Army Institute (28 WR 1, 31 WR 2 and 16 WR 3/4) was studied. HIV infected individuals presented, during the early stages, a progressive reduction of body weigth, as well as urea, albumin, total cholesterol, HDL cholesterol and LDL cholesterol in blood serum. However, increased serum levels of total protein, globulin, IgG, IgA, &#945;1 acid glycoprotein, haptoglobin, AST and LD were observed in HIV infected individuals during the evolution of infection. Decreased serum iron and a trend for increasing triglyceride was shown only for those individuals classified as WR 3/4. Transferrin was diminished only in the WR 2 group. A trend for enhancing serum ferritin following the progession of HIV infection was also observed. No alteration was observed on the levels of reactive \"C\" protein. Decreased EC-SOD activities were observed in HIV infected individuals as compared to controls, whereas in mononuclear cells the SOD activity was diminished only in WR 3/4 patients. HIV infection did not alter GSH-Px activity. A trend for decreasing &#945;-tocopherol and ascorbate plasma levels was shown during the evolution of HIV infected patients, while no difference was observed for &#946;-carotene levels in the studied groups. The above results suggest that haptoglobin, globulins and IgA can be used to assess the evolution of the HIV infection. Moreover, the decreased levels of the antioxidant defense system components observed in HIV infected patients may indicate that they are under an oxidative stress that could favor HIV replication.

No presente trabalho analisou-se um total de 101 indivíduos, sendo 26 não infectados e 75 infectados pelo HIV e classificados de acordo com o Walter Reed Army Institute (28 pacientes WR 1, 31 pacientes WR 2 e 16 pacientes WR 3/4). 05 indivíduos infectados pelo HIV apresentaram, nos estágios iniciais, uma diminuição progressiva do peso corporal, dos níveis séricos de uréia, albumina, colesterol total, HOL colesterol e LOL colesterol. Já os níveis séricos de proteínas totais, globulinas, IgG, IgA, &#945;1 glicoproteína ácida, haptoglobina e as atividades enzimáticas da AST e da LD apresentaram elevação nos indivíduos infectados e em conseqüência da evolução da infecção. Os triglicérides demonstraram apenas tendência para aumento dos níveis séricos nos indivíduos estadiados como WR3/4. Os níveis de ferro sérico encontraram-se diminuídos nos indivíduos estadiados como WR 3/4, enquanto que a concentração de transferrina apresentou-se diminuída apenas no Grupo WR 2. Houve uma tendência para a elevação progressiva dos níveis médios de ferritina com a evolução da doença. Nenhuma alteração foi verificada nos níveis de proteína \"C\" reativa. A EC-SOO apresentou diminuição dos níveis de atividade nos indivíduos infectados pelo HIV, enquanto que em células mononucleares a SOD apresentou atividade diminuída nos indivíduos estadiados como WR 3/4. A GSH-Px não apresentou alteração de sua atividade em decorrência da infecção pelo HIV. Os níveis plasmáticos do &#945;-tocoferol e do ascorbato apresentaram tendência para diminuição, enquanto o &#946;-caroteno não apresentou alteração nos grupos estudados. Estes resultados sugerem que a haptoglobina, as globulinas e a IgA podem ser utilizadas para a avaliação da evolução da infecção pelo HIV. Por outro lado, os níveis dos constituintes do sistema de defesa antioxidante analisados indicam que os indivíduos soropositivos encontram-se menos protegidos contra a ação de espécies reativas de oxigênio, o que favoreceria a presença de um estresse oxidativo e a replicação viral. / A total number of 101 individuals, including 26 controls and 75 patients classified according to the Walter Reed Army Institute (28 WR 1, 31 WR 2 and 16 WR 3/4) was studied. HIV infected individuals presented, during the early stages, a progressive reduction of body weigth, as well as urea, albumin, total cholesterol, HDL cholesterol and LDL cholesterol in blood serum. However, increased serum levels of total protein, globulin, IgG, IgA, &#945;1 acid glycoprotein, haptoglobin, AST and LD were observed in HIV infected individuals during the evolution of infection. Decreased serum iron and a trend for increasing triglyceride was shown only for those individuals classified as WR 3/4. Transferrin was diminished only in the WR 2 group. A trend for enhancing serum ferritin following the progession of HIV infection was also observed. No alteration was observed on the levels of reactive \"C\" protein. Decreased EC-SOD activities were observed in HIV infected individuals as compared to controls, whereas in mononuclear cells the SOD activity was diminished only in WR 3/4 patients. HIV infection did not alter GSH-Px activity. A trend for decreasing &#945;-tocopherol and ascorbate plasma levels was shown during the evolution of HIV infected patients, while no difference was observed for &#946;-carotene levels in the studied groups. The above results suggest that haptoglobin, globulins and IgA can be used to assess the evolution of the HIV infection. Moreover, the decreased levels of the antioxidant defense system components observed in HIV infected patients may indicate that they are under an oxidative stress that could favor HIV replication.