Clutch size in the small-sized lizard Eurolophosaurus nanuzae (Tropiduridae): does it vary along the geographic distribution of the species?

We studied life history traits of females of the lizard Eurolophosaurus nanuzae (Rodrigues, 1981), an endemic species of rock outcrop habitats in southeastern Brazil. During October 2002 and 2003 we sampled three populations in sites that encompass the meridional portion of the geographic range of the species. Clutch size varied from one to three eggs, with most females carrying two eggs. Clutch size did not vary among populations, but was correlated to female body size. Only larger females produced clutches of three eggs. Females of the small-sized E. nanuzae produce eggs as large as those of medium-sized tropidurids, thus investing a considerable amount of energy to produce clutches resulting in high values of relative clutch mass.

Why it is difficult to control Biomphalaria glabrata, the vector snail of schistosomiasis

The author studied some protective behaviors of Biomphalaria glabrata (vertical movements, response to molluscicides and response to water currents) and demonstrated how these activities hamper the control of this snail, which is the main vector of schistosomiasis in Brazil.

Chagas disease: from bush to huts and houses. Is it the case of the Brazilian amazon?

Two of the major problems facing the Amazon - human migration from the other areas and uncontrolled deforestation - constitute the greatest risk for the establishment of endemic Chagas disease in this part of Brazil. At least 18 species of triatomines had been found in the Brazilian Amazon, 10 of them infected with Trypanosoma cruzi, associated with numerous wild reservoirs. With wide-range deforestation, wild animals will perforce be driven into other areas, with tendency for triatomines to become adapted to alternative food sources in peri and intradomicilies. Serological surveys and cross-sectional studies for Chagas disease, carried out in rural areas of the Rio Negro, in the Brazilian Amazon, showed a high level of seropositivity for T. cruzi antibodies. A strong correlation of seroreactivity with the contact of gatherers of piaçava fibers with wild triatomines could be evidenced.

Skin reactions to thimerosal and Leishmania in dogs from a leishmaniasis endemic area: it is better to keep them apart

Positive Montenegro's skin test is a delayed type hypersensitivity reaction widely used as indicative of previous infection with Leishmania in both humans and dogs. Montenegro's antigen consists of a crude Leishmania antigen solution, usually containing thimerosal as preserving agent. In this work it is shown that a large proportion of dogs (11 out of 56) examined in an endemic area of leishmaniasis presented induration at the site of injection of a diluent containing thimerosal alone. This clearly demonstrates that thimerosal leads to a high number of false positive skin reactions in dogs and that its use in Montenegro's skin test antigenic preparations should be avoided.