Toxicological evaluation of the João da Costa e Associações® on Beagle dogs

A toxicological study was performed in Beagle dogs treated for 180 days with the product João da Costa e Associações. Were used six males and six females distributed in control and treated groups (n=3). We used a dose of 566 mg/kg of the product according to preclinical study in rodents. The animals were weighed and evaluated by clinical and laboratory aspects. The product did not cause mortality or alter the normal behavior of animals, but interfered with the weight gain on males in the middle phase of the treatment. The group treated had a lower incidence of clinical abnormalities compared to control, checked by veterinary consultations. Laboratory data showed elevated blood glucose levels perhaps due to the high amount of sucrose present in the product; about the histopathological data no significant change was found. We conclude that the product Joao da Costa and Associações, at the dose tested, has low toxicity in Beagle dogs treated chronically.

Genetic relatedness of Brazilian Colletotrichum truncatum isolates assessed by vegetative compatibility groups and RAPD analysis

The genetic variation among nine soybean-originating isolates of Colletotrichum truncatum from different Brazilian states was studied. Nitrate non-utilizing (nit) mutants were obtained with potassium chlorate and used to characterize vegetative compatibility reactions, heterokaryosis and RAPD profile. Based on pairings of nit mutants from the different isolates, five vegetative complementation groups (VCG) were identified, and barriers to the formation of heterokaryons were observed among isolates derived from the same geographic area. No complementation was observed among any of the nit mutants recovered from the isolate A, which was designed heterokaryon-self-incompatible. Based on RAPD analysis, a polymorphism was detected among the wild isolate C and their nit1 and NitM mutants. RAPD amplification, with five different primers, also showed polymorphic profiles among Brazilian C. truncatum isolates. Dendrogram analysis resulted in a similarity degree ranging between 0.331 and 0.882 among isolates and identified three RAPD groups. Despite the lack of a correlation between the RAPD analysis and the vegetative compatibility grouping, results demonstrated the potential of VCG analysis to differentiate C. truncatum isolates genotypically similar when compared by RAPD.

Benznidazole-induced genotoxicity in diploid cells of Aspergillus nidulans

Genotoxic effects of benznidazole were studied by the induction of homozygosis of genes previously present in heterozygous. UT448//A757 diploid strain was used in the benznidazole's recombinagenesis test. Although toxic effects on growth of colonies were not observed, 75 and 100 æM benznidazole induced an increasing of mitotic recombination events in diploid strain. Results were related to the induction of chromosomal breaks by the antiparasitic drug.