Evaluation of the in vivo mutagenic potential of hydroalcoholic extracts of the northern highbush blueberry (Vaccinium corymbosum L. Ericales, Ericaceae) on peripheral blood cells of Swiss mice (Mus musculus Rodentia, Muridae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Activity pattern of Cuniculus paca (Rodentia: Cuniculidae) in relation to lunar illumination and other abiotic variables in the southern Brazilian Amazon

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The role of seed mass on the caching decision by agoutis, Dasyprocta leporina (Rodentia: Agoutidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A new karyotype of Calomys (Rodentia, Sigmodontinae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A veia ázigos direita na cutia (Dasyprocta aguti, rodentia)

O comportamento da veia ázigos, sua formação e topografia foram estudados em 10 cutias (Dasyprocta aguti, rodentia) adultas (6 machos e 4 fêmeas, capturadas no estado do Piauí, Brasil). Este trabalho tem por objetivo constituir a base de outras investigações, particularmente aquelas referentes à exploração zootécnica desta espécie. O sistema de veia ázigos foi injetado com látex - Neoprene 671, e os animais foram colocados em solução aquosa de formol a 10%, e dissecados. em todas as espécies foi observado que a veia ázigos sempre chega na veia cava cranial em nível do quarto espaço intercostal. A veia ázigos recebe em (50%) dos casos as veias intercostais à direita e (50%) à esquerda. As tributárias da veia ázigos são: as veias frênicas (100%) e a veia bronco esofágica (30%). A veia hemiázigos aparece em todos os casos à esquerda e em 60% dos casos à direita. A veia ázigos comunica-se com a veia hemiázigos esquerda (90%), e com a direita (100%), com a veia cava caudal e veias intervertebrais, com igual freqüência (30%).

Modulation of parasitemia and antibody responce to Trypanosoma cruzy by cyclophosphamide in Calomys callosus (Rodentia, Cricetidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Configuração do sistema venoso portal na cutia (Dasyprocta aguti, RODENTIA)

O estudo da veia porta quanto aos vasos confluentes para sua formação e suas tributárias foi efetuado em 10 cutias (Dasyprocta aguti), adultas (3 fêmeas e 7 machos), nas quais o sistema desta veia foi injetado com látex corado, sendo a seguir fixadas em formol a 10% e dissecadas. Verificou-se que o tronco da veia porta origina-se sempre pela confluência de duas raízes, sendo representadas em 90% dos casos, pela veia lienal e pelo tronco mesentérico comum, constituído pelas veias mesentéricas cranial e caudal e, em 10%, pela veia lienal e pela veia mesentérica cranial. O tronco da veia porta recebe como tributárias a veia pancreaticoduodenal cranial (100%), a veia gástrica direita (90%) e, ainda, a veia gastroepiplóica direita (40%).

New record of Rhagomys rufescens (Thomas 1886) (Rodentia : Muridae : Sigmodontinae) in the Atlantic forest of southeastern Brazil

Rhagomys rufescens is a threatened Sigmodontinae rodent from the Atlantic forest of southeastern Brazil, known by a few specimens deposited in scientific collections. This work presents a new record of this species, collected in Parque Estadual da Serra do Mar-Nucleo Picinguaba (Ubatuba, SP) in April 2002, and some biological data. This finding reinforces the urgency of improving collecting efforts in Atlantic forest, in order to know and preserve its biodiversity.

CRANIOMETRIC VARIATION AND SUBSPECIFIC DIFFERENTIATION IN THRICHOMYS APEREOIDES IN NORTHEASTERN BRAZIL (RODENTIA, ECHIMYIDAE)

Thrichomys apereoides is an echimyid rodent which ranges in distribution from northeastern and central Brazil into Paraguay. Five subspecies are recognized, although each form is not well characterized and diagnosis is based primarily in pelage color variation. In this study we employed procedures from multivariate statistics to assess the systematic status of subspecies described from northeastern Brazil. The results of the craniometric analysis cannot be reconciled with the subspecies currently recognized for northeastern Brazil. Populations assigned to T. a. laurentius and T. a. inermis form a continuum of variation in cranial size, although they differ in cranial shape from a population from the locality of Bodoco in the state of Pernambuco. The implications of these findings for the systematics of T. apereoides are discussed.

Ontogenetic variation in skull shape of Thrichomys apereoides (Rodentia : Echimyidae)

The pattern of change in shape during postnatal development in skulls of punare (Thrichomys apereoides) skulls, was studied by geometric morphometric techniques. Skull shape observed in T. apereoides varied both with size and age, but variation in size explains most of the overall change in shape. Differences in shape observed among the eight age categories showed that main changes in shape occurred principally between the first and second age categories. Among the other age classes, changes became less pronounced leading to elongation of the snout and the mid-face and narrowing of the basicranium. The change in global shape resulted in lateral compression of the skull. Despite the high level of integration observed, localized transformations dominated the ontogenetic changes in shape indicating the presence of two large scale cranium components-the orofacial and the basicranial region. The ontogenetic pattern in this species seems to follow the same trends observed in the initial phases of development.

Cranial differentiation and evolution in Thrichomys apereoides (Rodentia: Echimyidae)

Thrichomys apereoides is an echimyid rodent which ranges in distribution from north-eastern and central Brazil into Paraguay, and currently five subspecies are recognized. Recent morphometric analyses of population samples formally assignable to T. a. laurentius and T. a. inermis, which occur in north-eastern Brazil, have shown that a major group of populations including both subspecies differ in cranial shape from a single population allocated to T. a. laurentius. In this study we employed mathematical models of evolutionary quantitative genetics to assess the role that random drift and selection may have played in the evolution of cranial shape differences in T. apereoides. The hypothesis of evolution due to drift was rejected and the selective forces necessary to account for shape differences were estimated. Minimum selective mortalities of the order of 10(-3) per generation were sufficient to explain the observed morphologic differentiation.

MODULATION OF PARASITEMIA AND ANTIBODY-RESPONSE TO TRYPANOSOMA-CRUZI BY CYCLOPHOSPHAMIDE IN CALOMYS-CALLOSUS (RODENTIA, CRICETIDAE)

Calomys callosus a wild rodent, previously described as harboring Trypanosoma cruzi, has a low susceptibility to infection by this protozoan.Experiments were designed to evaluate the contribution of the immune response to the resistance to T. cruzi infection exhibited by C. callosus. Animals were submitted to injections of high (200 mg/kg body weight) and low (20 mg/kg body weight) doses of cyclophosphamide on days -1 or -1 and +5, and inoculated with 4 x 10(3) T. cruzi on day O. Parasitemia, mortality and antibody response as measured by direct agglutination of trypomastigotes were observed. Two hundred mg doses of cyclophosphamide resulted in higher parasitemia and mortality as well as in suppression of the antibody response. A single dose of 20 mg enhanced antibody levels on the 20th day after infection, while an additional dose did not further increase antibody production. Parasitemia levels were not depressed, but rather increased in both these groups as compared to untreated controls. Passive transfer of hyperimmune C. callosus anti-T. cruzi serum to cyclophosphamide immunosuppressed animals resulted in lower parasitemia and mortality rates. These results indicate that the immune response plays an important role in the resistance of C. callosus to T. cruzi.