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Biomedical subjects

S M Brito

Publications and source records attributed to S M Brito.

4 recordsLinked to original sources
PubMed2005

Prevalence of IgG diphtheria antitoxin in blood donors in Rio de Janeiro.

The lack of information on the immunity of adults in Brazil against diphtheria prompted us to analyse sera from 234 blood donors aged 18-61 years (30.3% females and 69.7% males). IgG diphtheria antitoxin levels determined by means of an ELISA, validated by toxin neutralization test in Vero cells, showed that 30.7% (95% CI 25.0-37.1) of the population was fully protected (>or=1 IU/ml). The highest percentage of subjects fully protected was in the 31-40 years age group. Most of the subjects with uncertain or no protection (<1 IU/ml) were found in the 18-30 years age group (43.8%, OR 2.18, P=0.01). Antitoxin levels were not influenced by the increase in age. Males were more protected than females (80.5%, OR 0.44, P=0.01). The prevalence of 30% of individuals fully protected against diphtheria in blood donors in Rio de Janeiro supports the fact that immunity to diphtheria among healthy Brazilian adults is inadequate. To avoid diphtheria epidemics in the future the immunity among adults should be raised in the coming years.

Adolescent↗
PubMed2001

Effect of cold acclimation on brown adipose tissue fatty acid synthesis in rats adapted to a high-protein, carbohydrate-free diet.

The effect of cold acclimation on brown adipose tissue (BAT) fatty acid synthesis was investigated in rats adapted to a high-protein, carbohydrate-free diet. At an ambient temperature (25 degrees C), rates of fatty acid synthesis in BAT from rats adapted to the high-protein diet were reduced to 27% of rats fed the balanced diet and increased markedly after cold acclimation (10 days at 4 degrees C), although the increase was smaller than in control rats. BAT weight increase induced by cold acclimation was smaller in rats fed the high-protein diet (30%) than in controls (100%). When expressed per whole tissue, maximal activities of BAT glucose-6-phosphate dehydrogenase, malic enzyme, adenosine triphosphate (ATP)-citrate lyase, and acetyl-coenzyme A carboxylase were markedly reduced in high-protein diet-adapted rats at 25 degrees C and increased after cold acclimation in BAT from the 2 groups. However, when expressed per milligram protein, only acetyl-coenzyme A carboxylase showed an increase in both controls and in rats fed the high-protein diet. G6P-dehydrogenase, malic enzyme, and ATP-citrate lyase increased (per milligram protein) only in rats adapted to the high-protein diet and actually decreased in BAT from cold-acclimated control rats. Initial (before activation) pyruvate dehydrogenase (PDH) complex activity was lower in BAT from rats fed the high-protein diet at 25 degrees C and increased in cold-acclimated rats from the 2 groups. Circulating levels of insulin decreased in the 2 groups after cold acclimation. The data suggest that the cold acclimation-induced increase in BAT lipogenesis in rats adapted to the high-protein diet was due to a restoration of sympathetic activity, which induced both BAT hyperplasia and activation of adipocyte free fatty acid (FFA) synthesis, with an important participation of acetyl-coenzyme A carboxylase and pyruvate dehydrogenase.

ATP Citrate (pro-S)-Lyase↗