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Decreased Clearance (decreased + clearance)
Selected AbstractsOpsonization of late apoptotic cells by systemic lupus erythematosus autoantibodies inhibits their uptake via an Fc, receptor,dependent mechanismARTHRITIS & RHEUMATISM, Issue 10 2007Esther Reefman Objective Decreased clearance of apoptotic cells is suggested to be a major pathogenic factor in systemic lupus erythematosus (SLE). The aim of this study was to investigate whether the binding of SLE autoantibodies to apoptotic cells influences the phagocytosis of these cells by macrophages. Methods Apoptosis was induced in a human T cell line (Jurkat) and a keratinocyte cell line (HaCaT) by ultraviolet B irradiation. Binding of purified IgG from 26 SLE patients and 15 healthy controls to apoptotic cells was assessed by flow cytometry and Western blotting. Phagocytosis of IgG-opsonized apoptotic cells by monocyte-derived macrophages was assessed by light microscopy. Similar experiments were performed with a monoclonal antibody against SSA/Ro and IgG fractions from 5 patients with Sjögren's syndrome (SS) and 5 patients with rheumatoid arthritis (RA). Results IgG fractions from all 26 SLE patients bound to late apoptotic, but not early apoptotic, cells. IgG fractions isolated from SLE patients with different autoantibody profiles showed comparable levels of binding. IgG fractions from healthy controls did not bind. Opsonization of apoptotic cells with IgG fractions from SLE patients resulted in a significant inhibition of phagocytosis as compared with healthy control IgG fractions. A monoclonal antibody directed against SSA/Ro and IgG isolated from 5 antinuclear antibody (ANA),positive patients with SS were also able to elicit these effects, whereas IgG from 5 ANA-negative patients with RA did not. The inhibitory effect of patient IgG was abolished by blocking either the Fc, receptors (Fc,R) or the constant region of IgG, using a specific Fc-blocking peptide. Conclusion Autoantibodies from SLE patients are able to opsonize apoptotic cells and inhibit their uptake by macrophages via an Fc,R-dependent mechanism. [source] Lymphoscintigraphy of draught horses with chronic progressive lymphoedemaEQUINE VETERINARY JOURNAL, Issue 2 2006H. E. V. De Cock Summary Reasons for performing study: Early diagnosis of chronic progressive lymphoedema (CPL) may result in more effective interventions and provide a basis for further investigation of whether early diagnosis could be used as a means of eliminating potential genetic influences by cessation of breeding from affected individuals. Hypothesis: Lymphoscintigraphy may be useful in draught horses to differentiate early lesions of CPL from other conditions in the pastern region. Methods: Forelimbs of 2 normal and 5 CPL-affected draught horses were evaluated with lymphoscintigraphy. Results: Lymphoscintigraphy showed clearly the presence of interstitial fluid stasis and delayed lymphatic drainage in the affected extremities of diseased animals in contrast to normal animals of these breeds. The rate of decreased clearance of a particulate radiopharmaceutical from the tissues was related positively to the severity of clinical signs. Conclusions and potential relevance: Our findings support the hypothesis that lymph stasis is probably responsible for the progressive swelling and concurrent skin lesions observed in association with CPL in draught horses. Lymphoscintigraphy should also prove useful in diagnosis of CPL in draught horses, even in the mild stages of the disease; such early diagnosis may result in more effective intervention. [source] Excessive airway mucus in horses with pulmonary disease: is it caused by mucus overproduction, decreased clearance or both?EQUINE VETERINARY JOURNAL, Issue 3 2003P. M. DIXON No abstract is available for this article. [source] Differential role of IL-18 and IL-12 in the host defense against disseminated Candida albicans infectionEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 12 2003Mihai Abstract IFN-, plays a crucial role in the defense against infection with Candida albicans. Since IL-18 and IL-12 are strong stimuli of IFN-, production, we investigated whether endogenous IL-18 and IL-12 are involved in the host defense during disseminated candidiasis. IL-18 knockout (IL-18-/-) mice, but not IL-12-/- mice, displayed an increased mortality due to C. albicans infection, accompanied by a decreased clearance of the yeasts from the kidneys late during the course of infection. Histopathology of the organs, combined with phagocyte recruitment experiments, showed a decreased influx of monocytes at the sites of Candida infection, mainly in the IL-18-/- mice. Whereas production of the chemokine KC was decreased in both IL-18-/- and IL-12-/- mice, MIP-2 production was deficient only in IL-18-/- animals, which may explain the differences in phagocyte recruitment. In addition, although IFN-, production capacity, as a parameter of the Th1-protective immunity, was reduced by 65 to 80% in the IL-12-/- mice, this defect was even more pronounced in the IL-18-/- mice (85 to 95% downmodulation). In conclusion, the anticandidal effects of endogenous IL-18 are mediated late during the infection by assuring a proper IFN-, response and promoting the infiltration of the site of infection by monocytes. [source] | ||||||||||