RESUMO
A conversion index (CI) which measures the efficiency of utilization of dietary energy was found to be normally distributed in Wistar rats. The CI used was a ratio of the amount of food ingested to achieve an increment of one gram of body weight during the period of 32 days starting on day 21 after weaning. We have previously reported that male rats are more efficient energy converters than females. As a way to explore the hypothesis that the inheritance of the regulation of energy requirements is multifactorial, we mated F1 rats with high CI (poor energy converters) and studied the CI of their F2 offspring. The males behaved in agreement with the hypothesis as the F2 males had higher CI than the F1 males, but the behavior in females was different, i.e. the F2 were better converters than the F1. We have no explanation for this gender discrepancy.
Assuntos
Metabolismo Energético/genética , Animais , Metabolismo Basal/genética , Cruzamentos Genéticos , Ingestão de Energia , Feminino , Crescimento/genética , Masculino , Ratos , Ratos Wistar , Caracteres Sexuais , Aumento de Peso/genéticaRESUMO
A study of the nutritional status of beta-carotene and retinol of 228 institutionalized elderly individuals, in four elderly homes of México City was carried out. Subjects varied between 61 and 101 years of age (151 were females and 77 were males). High pressure liquid chromatography was used to quantitate retinol and beta-carotene. Ninety eight percent of elderly individuals showed beta-carotene levels less than acceptable (at risk); 85.2% were deficient (high risk), and 12.9% were low (medium risk), only 1.85% had acceptable values (low risk). Ninety two percent of subjects had acceptable values (low risk) of retinol, while 6.0% and 2.0% were low (medium risk) and deficient (high risk) respectively. There were not significant differences among the four elderly homes. No significant correlation with age was found for any of the two vitamins. No sex related difference (p > 0.05) was observed in serum vitamin A and beta-carotene in either group.
Assuntos
Carotenoides/sangue , Estado Nutricional , Vitamina A/sangue , Idoso , Idoso de 80 Anos ou mais , Carotenoides/deficiência , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Masculino , México , Valores de Referência , Fatores de Risco , Deficiência de Vitamina A/epidemiologia , beta CarotenoRESUMO
The use of metronidazole for the treatment of intestinal parasitosis has increased markedly, particularly in developing countries, where the association of malnutrition and parasitosis is very common. Since biotransformation of metronidazole is significantly affected by severe malnutrition, and undesirable effects of the drug seem to be related to its plasma concentration, it was decided to carry out a study to establish a dosing-regimen of metronidazole in severely malnourished children. A single dose of 30 mg/kg body weight, and computer simulation of a steady-state was studied in 10 malnourished and in 10 patients undergoing nutritional rehabilitation. Due to ethical considerations (refusal of parents to allow a second dose of metronidazole) acute malnourished children and rehabilitated patients are 2 distinct groups. The results indicate that a predicted drug cumulation would occur in malnourished children with the ordinary dosage regimen (30 mg/kg/day). Based on the clearance data, daily maintenance doses for pediatric patients with severe malnutrition should be 12.0 mg/kg/day, corresponding to a 60% reduction of the common dose calculated to achieve and maintain a plasma concentration of 6.0 micrograms/ml of metronidazole. The study illustrates the need for pharmacokinetic data to establish the individual dose of a drug particularly under conditions that alter biotransformation processes.
Assuntos
Metronidazol/administração & dosagem , Distúrbios Nutricionais/complicações , Doenças Parasitárias/complicações , Doenças Parasitárias/tratamento farmacológico , Biotransformação , Pré-Escolar , Simulação por Computador , Feminino , Humanos , Lactente , Masculino , Taxa de Depuração Metabólica , Metronidazol/sangue , Metronidazol/farmacocinética , Distúrbios Nutricionais/dietoterapia , Distúrbios Nutricionais/metabolismo , Doenças Parasitárias/metabolismo , Desnutrição Proteico-Calórica/complicações , Desnutrição Proteico-Calórica/metabolismoRESUMO
In attempting to explore the mechanisms of interaction of genetic and environmental factors that affect the quantitative requirements of energy by man, the convenience of an animal model was considered and searched for. The idea was to start with male and female Wistar rats and through inbreeding segregate the highly effective users of energy from the poor users. The efficiency of dietary energy utilization was measured by the index of conversion (IC) defined as the dietary intake necessary to increase 1 g of body weight in a 32-day period, from day 21st to day 52nd of extrauterine life. The median value of the IC for all animals included in each experiment was the cut-off point to classify each individual as a good or a poor energy user. The first generation had three males and five females with a median IC = 2.90 and a range from 2.54 to 3.25. The proportion of males below the median was 3/3 while the proportion of females was 2/5. The difference in proportions was striking and led immediately to the consideration of a sex-link hypothesis, and to test it the, IC of 91 Wistar rats randomly selected at birth was obtained. The median value of the series was 2.99 with a range from 2.24 to 3.95. The proportion of male rats with values below the median was 33/38 while the corresponding proportion for females rats was 13/53. In other words, while nine of every ten male animals were good users of energy, only two out of ten females fell into this category.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Metabolismo Basal/genética , Metabolismo Energético/genética , Modelos Biológicos , Necessidades Nutricionais , Ratos Wistar/genética , Ratos Wistar/metabolismo , Caracteres Sexuais , Animais , Ingestão de Energia , Feminino , Endogamia , Masculino , Ratos , Ratos Endogâmicos BN/genética , Ratos Endogâmicos BN/metabolismo , Ratos Endogâmicos Lew/genética , Ratos Endogâmicos Lew/metabolismo , Aumento de PesoRESUMO
Thirty-two Wistar albino rats were distributed at random in a factorial design 2 x 2, with two age groups (20 and 90 days old), and two treatments (chronically exposed to toluene vapors 30,000-40,000 ppm in air/15 minutes per day for 30 days, and controls with only air). Twenty-four hours after the last exposure, the rats were tested for conditioned behavior in a "T" maze of avoidance electric shock. Latency of initial response to escape (LIRE) and latency of escape (LE) were measured in seconds. Adult rats both exposed to chronic toluene inhalation and non-exposed showed higher values of LIRE and LE with respect young rats. Animals exposed to chronic toluene inhalation also presented higher values of latency in both LIRE and LE when compared to non-exposed to toluene (controls) of the same age. The differences were evaluated by Friedman's test. The findings are suggestive of brain dysfunction associated with chronic toluene inhalation, and may represent a delay to respond to a displeasure stimulus probably due to defect of internal mechanisms of facilitation-inhibition of neural impulses, mediated by neurotransmitters.
Assuntos
Aprendizagem da Esquiva/efeitos dos fármacos , Reação de Fuga/efeitos dos fármacos , Tolueno/toxicidade , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/fisiopatologia , Eletrochoque , Masculino , Neurotransmissores/metabolismo , Ratos , Ratos Wistar , Tempo de Reação/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Tolueno/administração & dosagemRESUMO
The relationship between two key factors involved in infant care and the frequency and duration of diarrhea, was search for in a cohort of rural infants followed-up from birth onwards. The specific questions asked were if the profile of mother-infant interaction, and the total score on home stimulation available to the infant were associated with the presence or absence of diarrhea, and with its total duration, expressed as the percentage of days with diarrhea over the number of days of age, in each semester of the first year of life of the infants. Frequency an duration of diarrhea, mother-infant interaction, and scores on home stimulation available to the infant showed no difference between baby-boys and baby-girls. The behavior of mothers of infants with diarrhea was not significantly different than the behavior exhibited by mothers of infants without diarrhea; even in the scales related to "quantity of physical contact with the infant", "type of physical contact with the infant", "response to infant's needs", and "sensitivity toward the infant". Similarly, neither the quality nor quantity of home stimulation showed association with the presence of diarrhea. Finally, none of the two microenvironmental attributes influenced the duration of diarrhea in either semester of the life of the infant. Although diarrhea is one of the most frequent antecedents of severe clinical malnutrition and in the latter both mother-infant interaction and home stimulation play a prominent role in the evolution from second degree to third clinical degree malnutrition, it seems important than those factors have a minimal influence in relation to diarrhea during the first year of life.
Assuntos
Diarreia Infantil/psicologia , Comportamento Materno , Relações Mãe-Filho , Feminino , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Masculino , México , Saúde da População Rural , Fatores SocioeconômicosRESUMO
OBJECTIVES: To determine the possible difference of the microenvironment of a group of children who lost weight in their first 15 days of life. DESIGN: Longitudinal ecological study of growth and development of a total cohort of all children born during a calendar year. SETTING: Rural village of Central Mexico. PARTICIPANTS: A group of sixteen children, who fifteen days after birth and without apparent reason, showed a decrease in weight as compared with weight at birth, they were compared with a control group from the same population and matched, case by case, according to gestation age, height at the time of birth, and body weight. MEASUREMENT AND MAIN RESULTS: To assess the influence of microenvironmental factors two indicators were used. Recording and scoring of maternal behavior was done by adaptation to local conditions by Cravioto et al, of the Maternal Behavior Profile developed by Nancy Bayley. The instrument used for estimating home stimulation was the inventory developed by Caldwell design to sample certain aspects of the quantity and/quality of social, emotional, and cognitive stimulation available to a young child within his home. No significant differences were found in relation to Maternal Behavior Profile and Home Stimulation in the two groups studied (statistical differences, P greater than 0.05). CONCLUSION: Data from present study contribute to the claim that systematic stimulation in the home and an adequate interrelation mother-child are among the main elements necessary for the proper development of the child.