Female and male Wistar rats (Rattus norvegicus) discriminate diets according to energetic quantity

The food choice of animals is influenced by several factors including the quantity and nutrients available. It is not known, however, whether faced with alternatives that present the same amount of food, with similar flavor and obtained with the same response cost, rats would discriminate between diets with different energetic quantities. The aim was to verify whether female and male Wistar rats (Rattus norvegicus) discriminate between three types of food that differ in their energetic content (whether or not they prefer one) and whether the flavor could affect the choice between two diets with equal energetic quantities. Twelve Wistar rats (six of each sex) underwent tests of choice between pairs of diets of different energetic values. After the tests, the animals had at their disposal, in the home cage, two diets with the same energetic content, which differed in flavor (one contained sucrose) - Flavor test. The consumption of each diet was measured for five consecutive days. All the subjects demonstrated a preference for the more energetic alternative, regardless of the combination of diets presented. In the Flavor test the animals did not show significant preference for any diet, i.e., the consumption of both the S and N diets were statistically equal for all subjects. It was concluded that the animals, regardless of sex, discriminated between the diets with different energetic values and that the flavor did not seem to be a determinant variable in the food choice.

Valor nutritivo de algumas dietas artificiais para Anastrepha obliqua (Diptera, Tephritidae)

Valor nutritivo de algumas dietas artificias para Anastrepha obliqua (Diptera, Tephritidae). Algumas dietas artificias, em diferentes concentrações, foram testadas e sua eficiência foi calculada a partir do peso das pupas, do tempo para apupar e da porcentagem de empupação. Os melhores resultados foram obtidos com fermento 4,5 g/ 150 ml de dieta; os outros produtos testados foram: germe de trigo, feijão soja, leite em pó e aveia

Omega-3 fatty acids induce biochemical changes in the small bowel of rats before and after resection

In the present study, the effect of dietary fish oil, a highly unsaturated fat source, on the intestinal mucosa before and after proximal small bowel resection in rats was studied. Forty Wistar rats were fed defined diets containing fish oil (experimental group) or corn oil (control group). After 2 weeks, animals underwent a 50% proximal small bowel resection. Mucosal disaccharidases, alkaline phosphatase, aminopeptidase, protein, DNA, and TBARs levels were assessed in samples immediately before and 6 and 12 days after surgery. Disaccharidase activities were reduced in the ileal mucosa from rats in the fish oil-fed group compared to the control group before and 12 days after surgery. The other parameters showed no significant differences. The results indicate that fish oil (omega-3 fatty acids) alters the functional parameters of the normal intestinal mucosa and after intestinal resection compared to omega-6 polyunsaturated fatty acids, suggesting that caution should be taken to use omega-3 fatty acids as adjuvants in the adaptive process after resection.No presente estudo, foi avaliado o efeito da dieta com óleo de peixe, uma fonte de ácidos graxos altamente insaturados, sobre a mucosa intestinal antes e após resecção do intestino delgado proximal em ratos. Quarenta ratos Wistar foram alimentados com dieta definida contendo óleo de peixe (grupo experimental) ou óleo de milho (grupo controle). Após duas semanas, os animais foram submetidos à ressecção de 50% do intestino delgado proximal. Os níveis das dissacaridases, fosfatase alcalina, animopeptidade, proteína, DNA e TBARS foram avaliados, imediatamente antes e 6 e 12 dias após a cirurgia. As atividades das dissacaridases foram reduzidas na mucosa ileal no grupo de ratos alimentados com óleo de peixe, comparado com grupo controle antes e 12 dias após a cirurgia. Os outros parâmetros não mostraram diferenças significativas. Este resultado indica que o óleo de peixe (ácidos graxos ômega-3) altera parâmetros funcionais na mucosa intestinal normal e após resecção, comparado ao ácido graxo ômega-6, sugerindo cautela no uso de ácidos graxos ômega-3 como adjuvante no processo adaptativo após resecção

Long-term follow-up of patients with chronic hepatitis C with sustained virologic response to interferon

BACKGROUND AND AIM: The durability of the sustained virologic response (SVR) in patients with chronic hepatitis C after treatment and the ideal follow-up time for these patients remains undefined. The objective of the study was to evaluate the durability of the virologic response in patients with chronic hepatitis C followed up for at least 12 months after SVR at HCFMRP-USP. METHODS: The study was conducted on 174 patients with chronic hepatitis C treated with different antiviral regimens who had achieved SVR. Qualitative serum HCV-RNA was determined by the commercial kit (COBAS AMPLICOR HCV, v2.0). RESULTS: There was predominance of male (73%) with a mean age of 45.6 ± 10 years. Liver cirrhosis was present in 16.1% of the study subjects. Mean follow-up time after SVR was 47 months (12-156 months). Twenty-two patients received monotherapy with interferon; 94 received interferon plus ribavirin, and 58 received pegylated interferon plus ribavirin. A total of 134 patients (77.0%) received one treatment course, 29 (16.7%) received two courses, and 11 (6.3%) received three courses. The distribution of HCV genotypes was: genotype 1 (40.2%), genotype 3 (40.8%) and genotype 2 (10.3%). Genotype was undetermined in 8.7% of cases. None of the 174 patients had recurrence of HCV infection. Two cirrhotic patients developed hepatocellular carcinoma (HCC) during follow-up. CONCLUSIONS: Among patients with SVR there was no recurrence of HCV infection or evidence of liver disease progression in any patient followed up for a mean of 47 months after SVR, except for patients with advanced hepatic disease before treatment, who may develop HCC despite SVR. Therefore, one can assume that SVR is associated with long term good prognosis.(FAEPA) Fundação de Apoio ao Ensino Pesquisa e Assistênci

Alcohol dehydrogenase activities and ethanol tolerance in Anastrepha (Diptera, Tephritidae) fruit-fly species and their hybrids

The ADH (alcohol dehydrogenase) system is one of the earliest known models of molecular evolution, and is still the most studied in Drosophila. Herein, we studied this model in the genus Anastrepha (Diptera, Tephritidae). Due to the remarkable advantages it presents, it is possible to cross species with different Adh genotypes and with different phenotype traits related to ethanol tolerance. The two species studied here each have a different number of Adh gene copies, whereby crosses generate polymorphisms in gene number and in composition of the genetic background. We measured certain traits related to ethanol metabolism and tolerance. ADH specific enzyme activity presented gene by environment interactions, and the larval protein content showed an additive pattern of inheritance, whilst ADH enzyme activity per larva presented a complex behavior that may be explained by epistatic effects. Regression models suggest that there are heritable factors acting on ethanol tolerance, which may be related to enzymatic activity of the ADHs and to larval mass, although a pronounced environmental effect on ethanol tolerance was also observed. By using these data, we speculated on the mechanisms of ethanol tolerance and its inheritance as well as of associated traits