Porophyllum ruderale (Jacq.) Cass. is a plant native to Brazil and in the northwest region of the state of Paraná, Brazil, aerial parts of P. ruderale have been used popularly in the treatment of lesions caused by Leishmania sp.. In this study the antileishmanial and cytotoxic activities of the crude extract, fractions, and isolated compounds from aerial parts of P. ruderale was evaluated. The ...

Pneumocystis organisms are airborne opportunistic pathogens that cannot be continuously grown in culture. Consequently, the follow-up of Pneumocystis stage-to-stage differentiation, the sequence of their multiplication processes as well as formal identification of the transmitted form have remained elusive. The successful high-speed cell sorting of trophic and cystic forms is paving the way for...

A method for quantifying bacterial populations introduced into an activated-sludge microbial community is described. The method involves extraction of DNA from activated sludge, appropriate dilution of the extracted DNA with DNA extracted from nonintroduced activated sludge, PCR amplification of a gyrB gene fragment from the introduced strain with a set of strain-specific primers, and quantific...

The hydrogenase and formate dehydrogenase levels in Syntrophobacter fumaroxidans and Methanospirillum hungatei were studied in syntrophic propionate-oxidizing cultures and compared to the levels in axenic cultures of both organisms. Cells grown syntrophically were separated from each other by Percoll gradient centrifugation. In S. fumaroxidans both formate dehydrogenase and hydrogenase levels w...

In Crocodylidae family three trypanosomes species were described, T. grayi in African crocodilian and T. cecili and Trypanosoma sp. in Caimans species from Brazil. T. grayi was transmitted by tsetse flies and the vector of Brazilian caimans trypanosomes is unknown. We characterized first Brazilian trypanosome isolated in spectacled caiman (Caiman crocodilus) from Mato Grosso State in Brazil. Mo...

Decomposition of natural populations of Lake Mendota phytoplankton dominated by blue-green algae (cyanobacteria) was monitored by using oxygen uptake and disappearance of chlorophyll, algal volume (fluorescence microscopy), particulate protein, particulate organic carbon, and photosynthetic ability (CO(2) up-take). In some experiments, decomposition of C-labeled axenic cultures of Anabaena sp. ...

Intracellular parasitic protozoans of the genus Leishmania depend for their survival on the elaboration of enzymic and other mechanisms for evading toxic free-radical damage inflicted by their phagocytic macrophage host. One such mechanism may involve superoxide dismutase (SOD), which detoxifies reactive superoxide radicals produced by activated macrophages, but the role of this enzyme in paras...

The biodegradation of three synthetic 14C-labeled polymers, poly(methyl methacrylate), phenol formaldehyde, and polystyrene, was studied with 17 species of fungi in axenic cultures, five groups of soil invertebrates, and a variety of mixed microbial communities including sludges, soils, manures, garbages, and decaying plastics. Extremely low decomposition rates were found. The addition of cellu...

The flagellated protozoan Giardia duodenalis is a common gastrointestinal parasite of mammals, including humans. Molecular characterizations have shown the existence of eight genetic groups (or assemblages) in the G. duodenalis species complex. Human infections are caused by assemblages A and B, which infect other mammals as well. Whether transmission routes, animal reservoirs and associations ...

In the rhabditid nematode Caenorhabditis briggsae the incorporation of thymidine-H(3) has been studied by autoradiography after Feulgen staining, with animals maintained under axenic conditions in a medium of only partly defined composition. Labeling has been followed in adults left in the presence of thymidine-H(3) for periods of from (1/2) to 24 hours, as well as in adults reared from larvae ...