Diversidade de ixodida em roedores e marsupiais capturados no Parque Estadual da Pedra Branca, Rio de Janeiro, Brasil / Diversity of ixodida in small rodents and marsupials in the Pedra Branca state park, state of Rio de Janeiro, Brazil

Durante 24 meses foram capturados, inspecionados e liberados no mesmo espaço do Parque Estadual da Pedra Branca, Rio de Janeiro, 96 marsupiais e 64 roedores. Neles foram recolhidos manualmente 105 carrapatos, de 10 espécies em duas famílias. A espécie de carrapato dominante entre os roedores foi Amblyomma longirostre e entre os marsupiais foi Ixodes loricatus. Houve correlação direta significativa entre a temperatura e a intensidade de parasitismo por carrapatos...

During 24 months 96 marsupials and 64 rodents were captured, inspected and set free in the same space of the Pedra Branca State Park, Rio de Janeiro. From them, 105 ticks from 10 species in two families were manually collected. The dominant tick species on the rodents was Amblyomma longirostre and on the marsupials was Ixodes loricatus. There was a significant correlation of the temperature in relation to intensity of parasitism for ticks, demonstrating that the higher the temperature, greater is the number of ticks...

Cytological and histopathological aspects of lipomas in Bothrops moojeni

O presente relato descreve os achados citológicos e histológicos de seis neoplasias benignas em cinco ofídios da espécie Bothrops moojeni mantidas em cativeiro por um período médio de 11,4 anos. Os animais apresentavam nódulos subcutâneos com localização variada desde o terço anterior até a porção mediana. Os exames citológico e histopatológico revelaram tratar-se de tumores lipomatosos benignos compatíveis com o subtipo lipoma fusocelular.

Study of the safety, immunogenicity and efficacy of attenuated and killed Leishmania (Leishmania) major vaccines in a rhesus monkey (Macaca mulatta) model of the human disease

We have compared the efficacy of two Leishmania (Leishmania) major vaccines, one genetically attenuated (DHFR-TS deficient organisms), the other inactivated [autoclaved promastigotes (ALM) with bacillus Calmete-Guérin (BCG)], in protecting rhesus macaques (Macaca mulatta) against infection with virulent L. (L.) major. Positive antigen-specific recall proliferative response was observed in vaccinees (79 percent in attenuated parasite-vaccinated monkeys, versus 75 percent in ALM-plus-BCG-vaccinated animals), although none of these animals exhibited either augmented in vitro gamma interferon (IFN-g) production or positive delayed-type hypersensitivity (DTH) response to the leishmanin skin test prior to the challenge. Following challenge, there were significant differences in blastogenic responses (p < 0.05) between attenuated-vaccinated monkeys and naïve controls. In both vaccinated groups very low levels of antibody were found before challenge, which increased after infective challenge. Protective immunity did not follow vaccination, in that monkeys exhibited skin lesion at the site of challenge in all the groups. The most striking result was the lack of pathogenicity of the attenuated parasite, which persisted in infected animals for up to three months, but were incapable of causing disease under the conditions employed. We concluded that both vaccine protocols used in this study are safe in primates, but require further improvement for vaccine application

Leishmania (Leishmania) major-infected rhesus macaques (Macaca mulatta) develop varying levels of resistance against homologous re-infections

Seven rhesus macaques were infected intradermally with 10(7) promastigotes of Leishmania (Leishmania) major. All monkeys developed a localized, ulcerative, self-healing nodular skin lesion at the site of inoculation of the parasite. Non-specific chronic inflammation and/or tuberculoid-type granulomatous reaction were the main histopathological manifestations of the disease. Serum Leishmania-specific antibodies (IgG and IgG1) were detected by ELISA in all infected animals; immunoblot analyses indicated that numerous antigens were recognized. A very high degree of variability was observed in the parasite-specific cell-mediated immune responses [as detected by measuring delayed-type hypersensitivity (DTH) reaction, in vitro lymphocyte proliferation, and gamma interferon (IFN-gamma) production] for individuals over time post challenge. From all the recovered monkeys (which showed resolution of the lesions after 11 weeks of infection), 57.2 percent (4/7) and 28.6 percent (2/7) animals remained susceptible to secondary and tertiary infections, respectively, but the disease severity was altered (i.e. lesion size was smaller and healed faster than in the primary infection). The remaining monkeys exhibited complete resistance (i.e. no lesion) to each rechallenge. Despite the inability to consistently detect correlates of cell-mediated immunity to Leishmania or correlation between resistance to challenge and DTH, lymphocyte transformation or IFN-gamma production, partial or complete acquired resistance was conferred by experimental infection. This primate model should be useful for measuring vaccine effectiveness against the human disease

Cell populations in lesions of cutaneous leishmaniasis of Leishmania (L. ) amazonensis- infected rhesus macaques, Macaca mulatta

The cellular nature of the infiltrate in cutaneous lesion of rhesus monkeys experimentally infected with Leishmania (L.) amazonensis was characterized by immunohistochemistry. Skin biopsies from infected animals with active or healing lesions were compared to non-infected controls (three of each type) to quantitate inflammatory cell types. Inflammatory cells (composed of a mixture of T lymphocyte subpopulations, macrophages and a small number of natural killer cells and granulocytes) were more numerous in active lesions than in healing ones. T-cells accounted for 44.7 +/- 13.1 of the infiltrate in active lesions (versus CD2+ = 40.3 +/- 5.7 in healing lesions) and T-cell ratios favor CD8+ cells in both lesion types. The percentage of cells expressing class II antigen (HLA-DR+) in active lesions (95 +/- 7.1) was significantly higher (P < 0.005) from the healing lesions (42.7 +/- 12.7). Moreover, the expression of the activation molecules CD25 (@ 16), the receptor for interleukin-2, suggests that many T cells are primed and proliferating in active lesions. Distinct histopathological patterns were observed in lesions at biopsy, but healing lesions contained more organized epithelioid granulomas and activated macrophages, followed by fibrotic substitution. The progression and resolution of skin lesions appears to be very similar to that observed in humans, confirming the potential for this to be used as a viable model to study the immune response in human cutaneous leishmaniasis.