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In the present paper, we developed a primary culture of Rhodnius prolixus salivary gland and main salivary canal cells. Cells remained viable in culture for 30 days. Three types of cells were indentified in the salivary gland cultures, with binuclear cells being the most abundant. The supernatants of salivary cultures contained mainly 16-24 kDa proteins and presented anticoagulant and apyrase activities. Secretion vesicles were observed budding from the cellular monolayer of the main salivary canal cells. These results indicate that R. prolixus salivary proteins may be produced in vitro and suggest that the main salivary canal may have a possible secretory role.

A presença de algumas macromoléculas no sangue esta associada a fenômenos de hiperviscosidade sangüínea e hiperagregação eritrocitária, quadro freqüente em algumas patologias (Diabetes, Hipertensão Arterial,etc). Este estudo investiga a agregação eritrocitária e sedimentação em amostras de sangue suíno, humano e bovino utilizando duas técnicas experimentais. O sangue humano e o de suínos agregam naturalmente formando roleaux enquanto o sangue bovino não agrega. A microestrutura foi investigada por microscopia óptica em amostras de sangue bovino (hematócrito 40%), suíno (hematócrito 1%, 5%, 10%, 30% e 40%) e humano (hematócrito 40%) e amostras de sangue bovino (hematócrito 40%) com adição de fibrinogênio nas concentrações de 5g/l, 10g/l, 20g/l, 25g/l e 30g/l. Os ensaios no Leitor de Microplacas foram realizados para se determinar o comportamento da agregação eritrocitária e sedimentação do sangue em função do hematócrito com e sem adição de fibrinogênio (para o sangue bovino). A microscopia óptica de luz transmitida permite a caracterização das microestruturas do sangue sob diferentes condições experimentais. Com o Leitor de Microplacas é possível distinguir-se três regiões no processo: a- Região I onde ocorre a agregação eritrocitária; b-Região II onde ocorre à predominância da etapa de sedimentação dos eritrócitos; e c- Região III onde ocorre um aumento lento da absorbância ocasionado também pela sedimentação dos eritrócitos. Associando a microscopia óptica com o Leitor de Microplacas é possível criar parâmetros para quantificar o processo de agregação e sedimentação do sangue, ferramentas úteis no diagnóstico e evolução de patologias que afligem tanto seres humanos como animais. The presence of some macromolecules in the blood is associated with blood hiperviscosity and hyperaggregation. We have studied erythrocyte aggregation and blood sedimentation on samples of swine, human and bovine blood. Bovine blood does not present erythrocyte aggregation while human and swine blood naturally aggregates at low shear rates and at stasis. The action of different bovine fibrinogen concentrations on the microstructure of bovine blood was analyzed and compared with swine and human blood. The phenomena were investigated using optical microscopy (to analyze blood microstructures) and Microplate Reader to measure absorbance (at a fixed wavelength, l=655nm) versus time(s). Experiments were performed using samples of bovine blood (hematocrit 40%), swine blood (H= 1%, 5%, 10%, 30% and 40%) and human blood (H= 40%); and samples of bovine blood (H= 40%) with the addition of bovine fibrinogen at different concentrations (5g/l, 10g/l, 20g/l, 25g/l and 30g/l). Using the Microplate Reader it was possible to distinguish three regions in the process: a-The region I where the erythrocyte aggregation occurs; b-region II where the sedimentation process is predominant and c-Region III where a very slow increase indicates that the persistence of sedimentation process. The association of the optical microscopy with the Microplate Reader technique makes possible the determination of quantitative parameters for the process of aggregation and sedimentation. These parameters will facilitate the diagnosis and a more accurate analysis of the evolution of pathologies that afflict both humans as animals.

Foram estudados alguns parâmetros biológicos e fisiológicos do Triatoma brasiliensis em comparação com o Triatoma infestans e com o Triatoma pseudomaculata. O T. brasiliensis, alimentado em camundongos, apresentou um ciclo evolutivo de ninfa de primeiro estádio a adulto mais rápido e uma fecundidade maior quando comparado às demais espécies. O T. infestans apresentou a maior velocidade de ingestão sangüínea nos dois hospedeiros testados, seguido pelo T. brasiliensis e pelo T. pseudomaculata. Os testes de coagulação nos quais foram utilizados extratos de glândulas salivares de T. brasiliensis apresentaram valores de atividade anticoagulante intermediários entre os de T. infestans e os de T. pseudomaculata. Biological and physiological parameters of Triatoma brasiliensis, Triatoma infestans, and Triatoma pseudomaculata were studied and compared. T. brasiliensis, reared on mice, showed a faster evolutionary cycle from first stage to adult and higher fecundity, when compared to the other species. T. infestans showed the fastest blood intake in both hosts tested, followed by T. brasiliensis and T. pseudomaculata. Clotting tests using salivary gland extracts of T. brasiliensis presented intermediary values of anti-clotting activity when compared to T. infestans and T. pseudomaculata.

Belostoma anurum was reared under laboratory conditions. Specimens were exposed to semi-natural conditions of photo period. The mortality rate was 26.3% during the post embryonic period (38.6 ± 0.7 days). During this time the average predation of Biomphalaria glabrata was of 99.0 ± 9.4 snails. The mean increment ratio of length and dry weight per instar was of 1.4 ± 0.1 and 2.8 ± 0.5, respectively. The predation by B. anurum adults can be divided into two different periods: phase I (4.8 ± 1.4 snails/day) and phase II (1.8 ± 0.5 snails/day). The higher predation in phase I suggested the sexual maturation of the belostomatid.

Among the 126 Brazilian members of the subfamily Triatominae, those of greatest epidemiological importance include Triatoma infestans, passively introduced into this country from Bolivia through human migrations; Panstrongylus megistus, with a wide distribution in humid forest areas; T. brasiliensis, indigenous to areas of caatinga scrub and with a great capacity to invade houses; T. pseudomaculata, also associated with caatinga areas but with predominantly peridomiciliar behaviour; and T. sordida, originally from areas of cerrado, and also mainly peridomiciliar (Forattini 1980, Alencar 1987). Following the recent elimination of domestic populations of T. infestans by the Chagas Disease Control Programme (Dias & Schofield 1999), the accelerated rate of environmental modification by man has meant that several other species once considered to be of secondary or even tertiary importance in the transmission of Trypanosoma cruzi to humans are beginning to be found relatively frequently and at surprisingly high densities in manmade habitats, with a corresponding risk of new foci of transmission becoming established (FNS 1998). It is hoped that the study of genetic characteristics of triatomines will facilitate identification of those species or populations with the greatest capacity for adaptation to different habitats, providing a valuable tool for epidemiological vigilance that allows us to determine which areas have the highest risk of domiciliation by the insects. In addition, the genetic characterization of triatomine populations will also allow us to determine what role the sylvatic insects play in the recolonization of areas treated with insecticide. In Bolivia, Dujardin and Cassini (1995) used morphometric comparisons of sylvatic T. infestans populations with domestic populations before and after residual spraying with insecticide to demonstrate that insects captured after treatment were survivors of the original population and not invaders from the surrounding wild habitat. This knowledge can be used to determine flaws in existing control measures and permit their improvement. The recent constitution of a network of studies