Influence of dietary protein content on Trypanosoma cruzi infection in germfree and conventional mice

Camundongos isentos de germes (GF) e convencionais (CV) foram alimentados com racoes contendo 4,4, 13,2 ou 26,4 por cento de proteina nao ganharam peso durante quatro semanas, enquanto a racao deficiente em proteina nao afetou o crescimento dos camundongos GF. Apos quatro semanas nessas racoes, os camundongos foram inoculados com 5x10 elevado ao cubo tripomastigotos de Trypanosoma cruzi. A deficiencia em proteina afetou menos os camundongos GF do que os CV, segundo os seguintes parametros: ganho em peso, hemoglobina, niveis em proteina e albumina no plasma e conteudos em agua e proteina na carcassa. A infeccao com T. cruzi produziu um decrescimo significante nos niveis em hemoglobina, na contagem de celulas vermelhas sanguineas e nos conteudos em agua e proteina na carcaca. Este decrescimo foi mais acentuado nos camundongos GF...

Valor nutritivo de uma dieta de frango para uso em recuperaçäo de crianças desnutridas / Nutritive value of a chicken-based diet for recovery of undernourished children

Determinou-se, em ratos, o valor nutritivo de uma dieta à base de frango desenhada para recuperaçäo de crianças desnutridas. Os valores do coeficiente de utilizaçäo protéica e da eficiência alimentar foram: 3,53 (mais ou menos) 0,17 e 0,33 (mais ou menos) 0,017, respectivamente, para a dieta de frango e 3,05 (mais ou menos) 0,07 e 0,31 (mais ou menos) 0,08 para a dieta padräo baseada em caseina. Esses valores foram estatisticamente diferentes. Näo se evidenciaram sinais de intoxicaçäo ou da presença de fatores antinutricionais em nenhum animal.

Effect of an essential fatty acid deficient diet on experimental infection with Trypanosoma cruzi in germefree and conventional mice

1) To investigate the possible role of essential fatty acid deficiency in host cell/parasite interaction, weanling germefree (GF) and conventional (CV) CFW mice maintained on an essential fatty acid-deficient (-) or a control (+) diet for 110 days were infected with Trypanosoma cruzi. 2) Blood parasitemia indicated that the disease was milder in the animals maintained on the essential fatty acid-deficient diet than in the GF and CV controls (maximum parasitemia: GF+33,300,GF-26,200,CV+17,100 and CV-6,400 trypomastigotes?ml blood). 3) Survival 30 days a after infection was 12% for GF+,28% for GF-,37% for CV+ and 65% for CV- mice. 4) Linoleic and arachidonic acid levels were significantly lower in animals kept on the essential fatty acid-deficient diet (GF-:28.0 ñ 9.3, 23.4 ñ 8.6; CV-:37.6 ñ 5.8, 19.9 ñ 3.6) than in controls (GF+: 164 ñ 48.8, 162.6 ñ 45.8; CV+: 147.1 ñ 26.5, 107.5 ñ 23.6) confirming the deficiency. Before the infection, succinic dehydrogenase levels were higher in liver of all CV mice *4.52 ug phosphate/mg fresh tissue) than in GF mice (0.84 ug phosphate/mg fresh tissue) whereas the opposite was true for 5'-nucleotidase levels in brain and liver, respectively (GF:2.84 and 3.18 ug phosphate/mg fresh tissue: CV:1.25 and 1.54 ug phosphate?mg fresh tissue). The disease was milder in deficient than in control animals in both the GF and CV groups on the basis of parasitemia and survival, indicating that fatty acid-deficient mice are partially protected against Chagas'disease. The mechanism underlying this phenomen requires further investigation

Immune responses of germfree mice to experimental infection with trypanosoma cruzi

1. The immune responses to Trypanosoma cruzi infection of germfree mice were compared to the reponses of infected conventional mice. Two groups (40 animals in each group) of 2-month old female CFW germfree and vonventional mice were used. The IgM and IgG which bound to the surface of T. cruzi epimastigotes determined by ELISA were significantly lower in germfree than in conventional mice (1/3 and 1/5 for IgM and IgG, respectively). 2. After infection there was a three-fold increase in the circulating levels of these immunoglobulins in germfree but not in conventional mice. twenty-one days after T. cruzi inoculation, both IgG and IgM levels were similar in germfree and conventional animals. 3. Footpad swelling after T. cruzi-antigen inoculation was initially four-fold more intense in germfree than in conventional mice. 4. These results suggest that the reduced humoral immune response of germfree mice during ythe initiation of experimental Chagas' disease may be responsible for the more severe parasitism when compared to conventional mice