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91.
After the initial observation that human and animal mononuclear phagocytes can be activated into specific killer cells against larvae of the parasite Schistosoma mansoni by seric IgE antibody from infected patients, a possible interaction of IgE with human alveolar macrophages in asthmatic patients was investigated. In vitro, alveolar macrophages from non-atopic individuals can bind monoclonal IgE molecules, as well as IgE antibody from the serum of patients with respiratory allergy. A subsequent contact with anti-IgE antibody or with the specific allergen induces the extracellular release of a variety of mediators, such as lysosomal enzymes, neutral proteases, or superoxide anion. Due to the presence of allergen-specific IgE antibody on the macrophage surface in situ, the same results were obtained in vitro with freshly purified alveolar macrophages from allergic patients. Disodium cromoglycate, corticosteroids, or beta-adrenergic stimulants are strong inhibitors of this specific exocytosis of physiological mediators. The atopic cells formed rosettes with allergen-coated erythrocytes at 4 degrees C, except after pretreatment with aggregated monoclonal IgE or with the allergen. 相似文献
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This paper presents an intelligent control method for the maximum power point tracking (MPPT) of a photovoltaic system under variable temperature and irradiance conditions. First, for the purpose of comparison and because of its proven and good performances, the perturbation and observation (P&O) technique is briefly introduced. A fuzzy logic controller based MPPT (FLC) is then proposed which has shown better performances compared to the P&O MPPT based approach. The proposed FLC has been also improved using genetic algorithms (GA) for optimisation. Different development stages are presented and the optimized fuzzy logic MPPT controller (OFLC) is then simulated and evaluated, which has shown better performances. 相似文献
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MJ Echeverría MJ López de Goicoechea R Ayarza Y Vecino MA Lazpita AB Ibarretxebea A Barbier M Cruz González P Martínez de la Fuente 《Canadian Metallurgical Quarterly》1997,15(6):319-322
Twenty eight of 227 patients undergoing restorative proctocolectomy for inflammatory bowel disease, familial adenomatous polyposis or functional disease were over the age of 50 years: ages 50 to 60 (n = 13), 60 to 70 (n = 10), and over 70 (n = 5). Major complications occurred in 5 patients over the age of 50 (18%) compared with 43 patients under the age of 50 (23%). Three patients above the age of 50 had their pouch excised (11%) compared with 23 under the age of 50 (12%). Functional outcome was assessed with a 12 point symptom score. This was similar in all age bands: under 50 years (mean = 2.2; sd +/- 2.2; n = 109), 50 to 60 years (mean = 2.5; sd +/- 2.5; n = 12), 60 to 70 years (mean = 2.8; sd +/- 2.3; n = 7) and over 70 years (mean = 4.0; sd +/- 3.7; n = 5): P > 0.05). When analysed for ulcerative colitis alone, no significant differences were seen between the two age groups. Restorative proctocolectomy in the elderly gives results which are comparable to the younger population. 相似文献
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EM Yoshida LA Mandl SR Erb AB Buckley CH Scudamore NA Buskard 《Canadian Metallurgical Quarterly》1997,24(4):274-275
The loss of immunotolerance has been implicated in the pathogenesis of both primary biliary cirrhosis (PBC) and idiopathic, immune-mediated thrombocytopenic purpura (ITP). An association between these two autoimmune diseases has been well described. We describe a 41-year-old woman in whom ITP developed 457 days after liver transplantation for PBC while receiving immunosuppressive medications sufficient to maintain allograft function. Our case report, the first to describe post-transplant ITP in association with PBC, demonstrates the persistence of the underlying immune dysregulation of PBC after transplantation. The practice of decreasing the dosage of immunosuppressive medication to maintenance levels after transplantation may unmask the effects of this defect in immunotolerance. 相似文献
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OBJECTIVES: Many patients with eating disorders complain of severe constipation. Previous studies have suggested that constipation in patients with anorexia nervosa may be associated with slow colonic transit. However, it is unclear whether a refeeding program will alter colonic transit in these patients. The aim of this study was to investigate colorectal function by measuring colonic transit and anorectal function in anorexic patients with constipation during treatment with a refeeding program. METHODS: We prospectively studied 13 female patients with anorexia nervosa who were admitted to an inpatient treatment unit and compared them to 20 previously studied, age-matched, healthy female control subjects. Patients underwent colonic transit studies using a radiopaque marker technique and anorectal manometry measuring anal sphincter function, rectal sensation, expulsion dynamics, and rectal compliance. Patients were studied both early (< 3 wk) and late (> 3 wk) in their admission. We restudied two patients who had slow colonic transit. All patients also underwent structured interviews. RESULTS: Four of six patients studied within the first 3 wk of their admission had slow colonic transit, defined as > 70 h (108.0 +/- 17.0 h, mean +/- SEM), on initial evaluation. In contrast, none of the seven patients studied later than 3 wk into their admission had slow colonic transit. Two of the four patients with slow transit were restudied later in their admission and were found to have normal transit times. Rectal sensation, internal anal sphincter relaxation threshold, rectal compliance, sphincter pressures, and expulsion pattern were normal in all subjects. CONCLUSIONS: Despite complaints of severe constipation, colonic transit is normal or returns to normal in the majority of patients with anorexia nervosa once they are consuming a balanced weight gain or weight maintenance diet for at least 3 wk. 相似文献
100.
The role of catecholamines in the distribution of intrarenal blood flow and in single-nephron glomerular filtration rate (SNGFR) was evaluated in anesthetized Wistar rats by the Hanssen technique. Epinephrine (EPI) and norepinephrine (NOR) were infused to produce elevations of 20-30 mmHg in mean arterial pressure. Superficial and juxtamedullary nephron perfusion and filtration were determined by the presence of Prussian blue dye. In the control group, 100% of the nephrons presented a homogeneous pattern of perfusion and filtration. In contrast, a heterogeneous distribution of the dye was found even in the larger arteries (arciform and radial), indicating variable perfusion and filtration in both superficial and juxtamedullary nephrons. The effects of EPI and NOR were also evaluated in the superficial cortex by the micropuncture technique in two additional groups of Munich-Wistar rats. Mean SNGFR was 27% and 54% lower in the EPI- and NOR-treated groups, respectively. No change in mean intraglomerular hydraulic pressure was observed after EPI or NOR infusion in spite of a highly scattered pattern, indicating an important variability in perfusion along the superficial cortex, and/or different sensitivity of the pre- and post-glomerular arterioles. The present data suggest that EPI and NOR may affect intrarenal hemodynamics by modifying perfusion and filtration in both superficial and juxtamedullary glomeruli and not by shifting blood flow from superficial to juxtamedullary nephrons. The heterogeneous pattern of perfusion was a consequence of differential vasoconstriction along the intrarenal arteries, probably due to different density and/or sensitivity of the adrenergic receptor subtypes present in the intrarenal vascular tree. 相似文献