An assessment of the genetic diversity of Leishmania infantum isolates from infected dogs in Brazil.

Correlations between the genetic diversity of Leishmania infantum (syn. L. chagasi) isolates and their respective geographic origins support the theoretic assumption that visceral leishmaniasis probably originated in the Old World. Because dogs are widely considered to be the main reservoir of this disease, the present study aimed to investigate the degree of genetic divergence among 44 leishmanial canine isolates from two Brazilian cities, Jequié and Campo Grande, located approximately 2,028 km from each other. We hypothesized that a low degree of genetic divergence would be observed among these isolates. In fact, statistical analyses found no significant differences between the isolates using both random amplified polymorphic DNA and multilocus microsatellite typing genotyping techniques with three and seven markers, respectively. These findings provide support for the recent introduction of L. infantum into the New World.

Observaçöes morfológicas do esôfago do "Caiman crocodilus yacare - Crocodilia-Reptila" (Daudin, 1802) / Morfological observation of the esophagus of \"Caiman Crocodilus Yacare - Crocodilia-Reptilia (Daudin, 1802)

Estudo da anatomia macroscópica e microscópica do esôfago do jacaré, Caiman crocodilus yacare. Neste animal, o esôfago sofre um desvio para a direita na regiäo cervical e um desvio a esquerda do plano mediano na regiäo caudal. Apresenta as Túnicas gerais Mucosa, Submucosa, Muscular e Adventícia. No epitélio de revestimento observam-se áreas com epitélio semelhante, ao de transiçäo e áreas com epitélio cilíndrico simples com células calciformes e algumas células basais. Na regiäo cranial a muscular de mucosa é mal definida e as células epiteliais cilíndricas säo ciliadas. A importância dessas observaçöes é discutida