29 research outputs found

    Role of breast regression protein 39 (BRP-39)/chitinase 3-like-1 in Th2 and IL-13–induced tissue responses and apoptosis

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    Mouse breast regression protein 39 (BRP-39; Chi3l1) and its human homologue YKL-40 are chitinase-like proteins that lack chitinase activity. Although YKL-40 is expressed in exaggerated quantities and correlates with disease activity in asthma and many other disorders, the biological properties of BRP-39/YKL-40 have only been rudimentarily defined. We describe the generation and characterization of BRP-39−/− mice, YKL-40 transgenic mice, and mice that lack BRP-39 and produce YKL-40 only in their pulmonary epithelium. Studies of these mice demonstrated that BRP-39−/− animals have markedly diminished antigen-induced Th2 responses and that epithelial YKL-40 rescues the Th2 responses in these animals. The ability of interleukin13 to induce tissue inflammation and fibrosis was also markedly diminished in the absence of BRP-39. Mechanistic investigations demonstrated that BRP-39 and YKL-40 play an essential role in antigen sensitization and immunoglobulin E induction, stimulate dendritic cell accumulation and activation, and induce alternative macrophage activation. These proteins also inhibit inflammatory cell apoptosis/cell death while inhibiting Fas expression, activating protein kinase B/AKT, and inducing Faim 3. These studies establish novel regulatory roles for BRP-39/YKL-40 in the initiation and effector phases of Th2 inflammation and remodeling and suggest that these proteins are therapeutic targets in Th2- and macrophage-mediated disorders

    Cryptosporidium sp. in children suffering from acute diarrhea at UberlĂąndia City, State of Minas Gerais, Brazil

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    This study's objective was to search for Cryptosporidium sp. in diarrheic feces from children aged zero to 12 years and cared for at medical units within Universidade Federal de UberlĂąndia or at a private practice in UberlĂąndia, State of Minas Gerais, Brazil, from September 1992 to August 1993. Three fecal samples preserved in 10% formalin, were collected from 94 children. Oocyst concentration was performed through Ritchie's (modified) method and staining of fecal smears for each sample (total of 1128 slides) was done by the "Safranin/Methylene Blue" and the "Kinyoun (modified)" techniques. The Hoffmann, Pons & Janer method was also employed to look for other enteroparasites. From 94 children, 4.26% excreted fecal Cryptosporidium oocysts. The infection seemed to vary according to age: 5.08% of patients aged zero to two years old; 33.33% of those aging eight to ten years (P>0.05). Cryptosporidium appeared in November, December and March, during the rainy season. 20.21% of the children harbored at least one enteroparasite different from Cryptosporidium, mainly Giardia intestinalis (12.77%). From Cryptosporidium infected patients, two had only this kind, another harbored Giardia intestinalis; the last one hosted Strongyloides stercoralis
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