Brucella abortus–infected platelets modulate the activation of neutrophils

Brucellosis is a contagious disease caused by bacteria of the genus Brucella. Platelets (PLTs) have been widely involved in the modulation of the immune response. We have previously reported the modulation of Brucella abortus–mediated infection of monocytes. As a result, PLTs cooperate with monocytes and increase their inflammatory capacity, promoting the resolution of the infection. Extending these results, in this study we demonstrate that patients with brucellosis present slightly elevated levels of complexes between PLTs and both monocytes and neutrophils. We then assessed whether PLTs were capable of modulating functional aspects of neutrophils. The presence of PLTs throughout neutrophil infection increased the production of interleukin‐8, CD11b surface expression and reactive oxygen species formation, whereas it decreased the expression of CD62L, indicating an activated status of these cells. We next analyzed whether this modulation was mediated by released factors. To discriminate between these options, neutrophils were treated with supernatants collected from B. abortus–infected PLTs. Our results show that CD11b expression was induced by soluble factors of PLTs but direct contact between cell populations was needed to enhance the respiratory burst. Additionally, B. abortus–infected PLTs recruit polymorphonuclear (PMN) cells to the site of infection. Finally, the presence of PLTs did not modify the initial invasion of PMN cells by B. abortus but improved the control of the infection at extended times. Altogether, our results demonstrate that PLTs interact with neutrophils and promote a proinflammatory phenotype which could also contribute to the resolution of the infection.Fil: Trotta, Aldana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Milillo, María Ayelén. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Serafino, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Castillo Montañez, Luis Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Birnberg Weiss, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Delpino, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Giambartolomei, Guillermo Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; ArgentinaFil: Fernández, Cecilia Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Barrionuevo, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentin

The in vitro effects of some benzoxazolone derivatives on human leukocyte myeloperoxidase activity

31st Congress of the Federation-of-European-Biochemical-Societies (FEBS) -- JUN 24-29, 2006 -- Istanbul, TURKEYWOS: 000238914001057Federat European Biochem So

Aspects of oxalosis associated with aspergillosis in pathology specimens

Oxalosis (calcium oxalate deposition) is associated with various conditions, including aspergillosis. Some Aspergillus species produce oxalic acid, which reacts with blood or tissue calcium to precipitate calcium oxalate. Calcium oxalate crystals exhibit various shapes and are strongly birefringent. These occur in cytological specimens, as well as in tissues of patients with Aspergillus infection. Aspergillus species are hyaline septate moulds, and they can be accurately recognized in pathology specimens only if conidial heads (fruiting heads) are present. When these structures are not observed, detection of associated oxalosis in a mould infection supports the pathological diagnosis of aspergillosis. The presence of oxalosis is helpful when microbiological identification or immunohistological techniques for fungi are not available. Calcium oxalate crystals can induce cellular injury by several mechanisms, and there is increasing evidence that oxalosis-induced tissue damage may occasionally lead to a poor clinical outcome. This review discusses the diagnostic value and the potential clinical significance of oxalosis associated with aspergillosis. (c) 2005 Elsevier GmbH. All rights reserved

JAPANESE JOURNAL OF INFECTIOUS DISEASES

The aim of the present study was to compare serological tests (Rose Bengal [RB]; standard agglutination test [SAT]; enzyme immunoassay [ETA] for detection of IgM, IgA, and IgG; and 2-mercaptoethanol [2-ME] test) that are routinely used in patients prediagnosed with different clinical types of brucellosis (acute, subacute, or chronic), and to evaluate the results of the IgG avidity test. Ninety-two patients having titers >= 1/160 as measured by SAT were included in the study. The IgG avidity test was performed in 78 patients who had positive EIA-IgG results. RB test results were positive in 88 (95.7%) patients. A statistically significant correlation was found between a positive EIA-IgM result and the diagnosis of acute brucellosis. When compared to the results of the SAT, the 2-ME test showed a lower titer in 55 (59.8%) patients, and the agreement between the 2-ME test and EIA-IgG was calculated as 84.8%. No statistical difference was found between the 40% avidity index used in the IgG avidity test and avidity maturation time (6 months). From our study, we concluded that (i) the RB and SAT tests are appropriate and reliable tests for the serological diagnosis of brucellosis; (ii) IgM can be used as a marker of acute brucellosis; (iii) the 2-ME test, similar to EIA, can be used to determine IgM levels; and (iv) the IgG avidity test should be standardized