153 research outputs found
Environmental isolation of black yeast-like fungi involved in human infection
The present study focuses on potential agents of chromoblastomycosis and
other endemic diseases in the state of ParanĂĄ, Southern Brazil. Using a
highly selective protocol for chaetothyrialean black yeasts and relatives,
environmental samples from the living area of symptomatic patients were
analysed. Additional strains were isolated from creosote-treated wood and
hydrocarbon-polluted environments, as such polluted sites have been supposed
to enhance black yeast prevalence. Isolates showed morphologies compatible
with the traditional etiological agents of chromoblastomycosis, e.g.
Fonsecaea pedrosoi and Phialophora verrucosa, and of agents of
subcutaneous or systemic infections like Cladophialophora bantiana
and Exophiala jeanselmei. Some agents of mild disease were indeed
encountered. However, molecular analysis proved that most environmental
strains differed from known etiologic agents of pronounced disease syndromes:
they belonged to the same order, but mostly were undescribed species. Agents
of chromoblastomycosis and systemic disease thus far are prevalent on the
human host. The hydrocarbon-polluted environments yielded yet another spectrum
of chaetothyrialean fungi. These observations are of great relevance because
they allow us to distinguish between categories of opportunists, indicating
possible differences in pathogenicity and virulence
PIBF+ extracellular vesicles from mouse embryos affect IL-10 production by CD8+ cells
Earlier evidence suggests, that the embryo signals to the maternal immune system. Extracellular vesicles (EVs) are produced by all types of cells, and because they transport different kinds of molecules from one cell to the other, they can be considered as means of intercellular communication. The aim of this work was to test, whether the embryo is able to produce sufficient amounts of EVs to alter the function of peripheral lymphocytes. Embryo-derived EVs were identified by their Annexin V biding capacity, and sensitivity to Triton X dependent lysis, using flow cytometry. Transmission electron microscopy was used to detect EVs at the implantation site. Progesterone-induced blocking factor (PIBF) expression in embryo-derived EVs was demonstrated with immuno-electron microscopy. The % of IL-10 + murine lymphocytes was determined by flow cytometry. EVs were present in embryo culture media, but not in empty media. Mouse embryo-derived EVs adhere to the surface of both CD4+ and CD8+ murine peripheral T lymphocytes, partly, via phosphatidylserine binding. The number of IL-10+ murine peripheral CD8+ cells increases in the presence of embryo-derived EVS, and this effect is counteracted by pre-treatment of EVs with an anti-PIBF antibody, suggesting that the embryo communicates with the maternal immune system via EVs
Skeletal Diversification via Heteroatom Linkage Control: Preparation of Bicyclic and Spirocyclic Scaffolds from NSubstituted Homopropargyl Alcohols
The discovery and application of a new branching pathway synthesis strategy that rapidly produces skeletally diverse scaffolds is described. Two different scaffold types, one a bicyclic iodo-vinylidene tertiary amine/tertiary alcohol and the other, a spirocyclic 3-furanone, are each obtained using a two-step sequence featuring a common first step. Both scaffold types lead to intermediates that can be orthogonally diversified using the same final components. One of the scaffold types was obtained in sufficiently high yield that it was immediately used to produce a 97-compound library
Expanding Stereochemical and Skeletal Diversity Using Petasis Reactions and 1,3-Dipolar Cycloadditions
A short and modular synthetic pathway using intramolecular 1,3-dipolar cycloaddition reactions and yielding functionalized isoxazoles, isoxazolines, and isoxazolidines is described. The change in shape of previous compounds and those in this study is quantified and compared using principal moment-of-inertia shape analysis.Chemistry and Chemical Biolog
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