Contribuição ao estudo da interrelação flúor-manganês em ratos

Devido a numerosas discrepâncias nos resultados de estudos experimentais relativos à interação flúor-manganês, propusemo-nos a verificar se a adição de manganês 5 água fluoretada (1 ppm), em diferentes proporções fluor-manganês, levaria a uma diferente fixaçao do halogênio. Para tanto, 24 ratos Wistar, recém-desmamados, foram mantidos em dieta padrão de caseína a 27%, recebendo na sua água de consumo: 1) H2O destilada (controle); 2) 1,0 ppm de flúor: 3) 1,0 ppm de flúor + 0,5 ppm de manganês (F:Mn = 2,0); 4) 1,0 ppm de flúor +1,0 ppm de manganês (F: Mn = 1,0). Foram anotados o peso ganho e o consumo de alimento e água, durante os 60 dias de experimento, após o qual as patas traseiras, dos animais sacrificados, foram autoclavadas e desossadas, e os femures retirados. Posteriormente, foram estes submetidos à secagem, extração da gordura, pulverização e analise do flúor fixado. Também foram efetuadas analises da composição centesimal da ração e de flúor e manganês nesta e nas diferentes águas de consumo. Os resultados de percentagem do flúor ingerido fixado nos femures, foram analisados estatisticamente pelo teste não-paramétrico de Kruskal-Wallis (níveis de 1% e 5%) mostrando que, para as proporções consideradas, o flúor na taxa de 1 ppm, o manganês, quando administrado após o desmame, parece não afetar a fixaçao do flúor. Contudo, faz-se necessário dar continuidade aos estudos com novas proporções e taxas mais elevadas de flúor e manganês.An experiment to determine the effects of varying the manganese concentration of the diet on the fluorine retention in the femur of rats was made. Four groups of weaning rats were fed ad libitum a 27% casein synthetic diet and were provided with water as follows: 1) distilled (control); 2) containing 1 ppm of fluorine (F); 3) 1,0 ppm F + 0,5 ppm Mn; 4) 1 ppm F + 1 ppm Mn. The weight gain and food and water consumption were measured during 60 days. The results indicated that manganese does not seem to affect the proportional fixation of fluorine in the femur. The authors think that more data should be available before a definite conclusion on the influence of the ratio F:Mn on the fluorine retention could be drawn

Associação entre larvas de Chrysomya megacephala (Fabricius) e Chrysomya albiceps (Wiedemann), Chrysomya megacephala (Fabricius) e Cochliomyia macellaria (Fabricius) (Calliphoridae, Diptera) sob condições de laboratório Association between Chrysomya megacephala (Fabricius) and Chrysomya albiceps (Wiedemann), Chrysomya megacephala (Fabricius) and Cochliomyia macellaria (Fabricius) larvae (Calliphoridae, Diptera), under laboratory conditions

<abstract language="eng">This paper intends to recognize some aspects of interspecific relationships between Chrysomya megacephala (Fabricius) and C. albiceps (Wiedemann) and between C. megacephala and Cochliomyia macellaria (Fabricius) larvae in laboratory. A diet consisting of decomposing horse flesh was used, and the relation of 1 larva/g diet was established. The development of the two species was done in pure and associated cultures. The association with Chrysomya albiceps influenced the post-embrionary development period and the weight of mature larvae of the C. megacephala, reducing their. Such weight decrease, along with the predation of larvae of C. megacephala larvae, yelded a decrease in survival in all of the stages. Larvae of this species showed an increase in its weight when associated with Cochliomyia macellaria. The native species responded to the association by reducing its body weigth and its viability. This association doesnt influence the duration of post-embrionary development