Identification and characterization of the S-layer formed on the sheath of Thiothrix nivea.

Thiothrix nivea is a filamentous sulfur-oxidizing bacterium common in activated sludge and its filament is covered with a polysaccharide layer called sheath. In this study, we found that T. nivea aggregates under acidic conditions.

Enzymatic degradation of β-1,4-linked N-acetylglucosaminoglucan prepared from Thiothrix nivea.

Thiothrix nivea is a filamentous sulfur-oxidizing bacterium commonly found in activated sludge. The filament of this bacterium is covered with a sheath. The sheath is an assemblage of macromolecular glucosaminoglucan (GG), [4)-β-d-GlcN-(1 → 4)-β-d-Glc-(1 → ], modified with an unidentified deoxy-sugar at position 3 of Glc.

Detection of antibodies against Paracoccidioides brasiliensis in free-range domestic pigs (Sus scrofa).

Paracoccidioidomycosis, caused by the thermodimorphic fungus Paracoccidioides brasiliensis, is a human systemic mycosis prevalent in Latin America. Paracoccidioidomycosis affects mainly male rural workers, causing granulomatous lesions in several organs such as the lungs, liver and spleen. The participation of other animal species in the fungus epidemiology is not well understood.

Involvement of regulatory T cells in HIV immunopathogenesis.

Recently, a mechanism of negative regulation of immune responses by a specialized population of so-called regulatory T cells (Tregs) has become a focus of intense investigation. Through the discovery of transcription factor Foxp3 as a central molecular determinant of Tregs differentiation and function, the complex biology of these cells, including maintenance of immunological tolerance to "self" and regulation of immune responses to pathogens, commensals, and tumors, has become the focus of intense investigation. The ability to control the infection and to delay the progression of the infection to AIDS and/or death is probably regulated by a balance between host factors, such as immunologic response and viral factors.