Spatial dynamics of urban populations of Lutzomyia longipalpis (Diptera: Psychodidae) in Caxias, State of Maranhão, Brazil.

Introduction: In this paper, we report the ecology of Lutzomyia longipalpis in Caxias City, located in the eastern part of State of Maranhão, Brazil and highlight its seasonal and geographical distribution by environment. In addition, we discuss natural Leishmania infection and its relationship with visceral leishmaniasis.

Methods: Between September 2007 and August 2009, the collection of sandflies was performed using Center for Disease Control (CDC) light traps from 15 houses in 5 selected neighborhoods.

Activation of the human complement system by pigmented and hypopigmented mycelia of the fungus Fonsecaea pedrosoi.

The action of the complement system on pigmented and hypopigmented mycelia of the fungus Fonsecaea pedrosoi, the major aetiological pathogen of the chromoblastomycosis is herein discussed. Fungi were grown in medium Czapeck-Dox at 37°C, for 14 days, without shaking to obtain pigmented mycelium. To obtain hypopigmented mycelium, the fungus was grown at the same conditions, but in the dark and with low oxygenation.

Spores of Mucor ramosissimus, Mucor plumbeus and Mucor circinelloides and their ability to activate human complement system in vitro.

Complement activation by spores of Mucor ramosissimus, Mucor plumbeus and Mucor circinelloides was studied using absorbed human serum in the presence or absence of chelators (EGTA or EDTA). We found that the spore caused full complement activation when incubated with EGTA-Mg2+ or without chelators, indicating that the alternative pathway is mainly responsible for this response. In order to compare activation profiles from each species, ELISAs for C3 and C4 fragments, mannan binding lectin (MBL), C-reactive protein (CRP) and IgG studies were carried out.

Migration inhibitory factor (MIF) released by macrophages upon recognition of immune complexes is critical to inflammation in Arthus reaction.

Deposition of immune complexes (IC) triggers Fc gamma R-dependent inflammation, leading to tissue damage in rheumatoid arthritis, systemic lupus erythematous, immune glomerulonephritis, and several immune vasculitides. Evidences support a role for macrophage migration inhibitory factor (MIF) in a number of inflammatory diseases, but the triggering of its secretion and its physiopathological role upon IC deposition remain elusive. Herein, we show that human macrophages secreted MIF after IC recognition, which in turn controlled the secretion of TNF.

Frequencies of feline blood types in the Rio de Janeiro area of Brazil.

Background: The distribution and frequency of blood types in cat populations vary according to geographic region and breed. Frequencies of feline blood types in Rio de Janeiro city, as well as in other Brazilian areas, are unknown, and the risk of unmatched transfusions and neonatal isoerythrolysis has not been estimated.

Objectives: The purpose of this study was to determine the frequency of feline blood types in the area of Rio de Janeiro, Brazil.

Biotin-psolaren labeled cDNA amplicons for genotyping rotavirus strains by dot hybridization assay.

A simple method to produce biotinylated probes by utilizing an amine-psoralen to conjugate an ester-biotin to nucleic acid molecules is described. It is simple, rapid, and well suited to label cDNA probes with any PCR-generated amplicon for hybridization assay. Its application to identify or to confirm the G and P genotypes of rotavirus-derived amplicons is described; however, it may be used to label amplicons of any origin.

Characterization of sialidase from an influenza A (H3N2) virus strain: kinetic parameters and substrate specificity.

Neuraminidase (NA) of influenza A (H3N2) viruses was characterized after purification by gel filtration and proteolytic treatment, using the X-31 variant strain that is a reassortment between the influenza A/Victoria/3/75 (responsible for the 1975 pandemic) and the influenza A/PR/8/34 virus samples, as a model. In the purification process, NA heads, that is the spike responsible for the virus sialidase activity, were purified by filtration through a Bio-Gel polyacrylamide column. The enzyme activity was determined by periodic acid/thiobarbituric acid assay and high-performance thin-layer chromatography.