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To test the hypothesis that complement-mediated cell lysis and cell-mediated cytotoxicity operate by analogous mechanisms, cell membranes from two antibody-dependent cytotoxicity systems were examined by electron microscopy after negative staining. Ring-shaped membrane lesions generally similar to, but larger than, those previously described for complement lysis were observed. These findings are in agreement with recent measurements of larger functional pores for ADCC than complement.  相似文献   
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Enterohemorrhagic Escherichia coli (EHEC) infections are associated with the modification of tight-junction permeability and synthesis of proinflammatory cytokine interleukin-8 (IL-8). In a previous study, it was demonstrated that EHEC-induced IL-8 secretion is due to the involvement of the mitogen-activated protein kinase (MAPK), AP-1, and NF-kappaB pathways. In this study, we investigated the effect of the yeast Saccharomyces boulardii on EHEC infection in T84 cells. For this purpose, cells were (i) incubated with bacteria and yeast at the same time or (ii) incubated overnight with yeast cells that were maintained during infection or eliminated by several washes before infection. Coincubation is sufficient to maintain the transmonolayer electrical resistance (TER) of EHEC-infected cells, whereas the preincubation of cells with the yeast without elimination of the yeast during infection is necessary to significantly decrease IL-8 secretion. We thus analyzed the mechanisms of S. boulardii action. We showed that S. boulardii has no effect on EHEC growth or on EHEC adhesion. Kinetics studies revealed that EHEC-induced myosin light chain (MLC) phosphorylation precedes the decrease of TER. ML-7, an MLC kinase inhibitor, abolishes the EHEC-induced MLC phosphorylation and decrease of TER. Studies show that S. boulardii also abolishes EHEC-induced MLC phosphorylation. We demonstrated that the preincubation of cells with S. boulardii without washes before EHEC infection inhibits NF-kappaB DNA binding activity, phosphorylation and degradation of IkappaB-alpha, and activation of the three members of a MAPK group (extracellular signal-regulated protein kinases 1 and 2, p38, and c-jun N-terminal kinase). These findings demonstrate that S. boulardii exerts a preventive effect on EHEC infection by (i) interfering with one of the transduction pathways implicated in the control of tight-junction structure and (ii) decreasing IL-8 proinflammatory secretion via inhibition of the NF-kappaB and MAPK signaling pathways in infected T84 cells.  相似文献   
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The effects of 2 weeks of refeeding by cyclic enteral nutrition on chronically malnourished (mean global nutritional deficiency 19.9 +/- 1.1%) hospitalized patients were assessed in a prospective study with special attention paid to immunological status. All patients were immunodeficient, with cell-mediated immunity being more affected than humoral immunity. After 2 weeks of refeeding, nutritional status had improved by 29.8%. Initially abnormal parameters of humoral immunity (IgM, C3 and C4) improved significantly (P < 0.05) between day 0 and day 15. The following cell-mediated immunity parameters also improved significantly (P < 0.05): CD8, monocyte count, natural killer cell activity and skin tests. Short-term refeeding by cyclic enteral nutrition appears to be a safe and effective way of improving immunodeficiency in chronically malnourished patients, with predictable consequences on infection.  相似文献   
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The aim of this study was to assess resting energy expenditure in patients with chronic pancreatitis; 33 patients with alcohol-related chronic pancreatitis (group 1: 13 normal weight, group 2: 20 underweight) and 11 undernourished patients without identifiable disease (group 3) were studied. Body composition was determined by bioelectric impedance analysis and energy expenditure by indirect calorimetry. The percentage of body weight occupied by fat-free mass was similar among the three groups (76.4±1.5%, 78.6±1.3% and 76.8±2.1% for groups 1, 2, and 3, respectively). The measured resting energy expenditure (REE) was higher than the predicted EE (Harris and Benedict formula and Cunningham's equation) for the underweight patients with chronic pancreatitis (group 2) (P<0.05), but not for the two other groups. According to Cunningham's equation, 65% of the group 2 patients were hypermetabolic (REE>110% of predicted EE) versus 23.1% and 20% in groups 1 and 3. When adjusted for fat free mass, REE was significantly (P<0.01) higher in group 2 (35.0±0.9 kcal/kg/24 hr) than in the other two groups (30.1±0.7 kcal/kg/24 hr and 30.8±1.4 kcal/kg/24 hr in groups 1 and 3, respectively). During chronic pancreatitis, weight loss is accompanied by hypermetabolism, which should be taken into consideration during nutritional support.  相似文献   
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OBJECTIVES: The aim of this study was to assess the diagnostic accuracy of noninvasive markers of liver fibrosis in alcoholic liver disease. PATIENTS AND METHODS: Fifty-four clinical and biochemical parameters including serum fibrosis markers (hyaluronate and transforming growth factor beta1) were analyzed in 146 consecutive heavy drinkers (106 men, 40 women; mean age 49.2 years). Following liver biopsy, fibrosis was evaluated using a semi-quantitative scoring system (no fibrosis (0) to severe fibrosis (3 + )). Multivariate analysis was performed to determine the markers that were best correlated with the fibrosis score. RESULTS: Fifty-nine patients (40.4 %) had severe fibrosis (3 +) while 87 (59.6 %) had no fibrosis or moderate fibrosis (0 to 2 +). In multivariate analysis, serum hyaluronate and the prothrombin index were the best markers for the prediction of severe fibrosis. Hyaluronate and the prothrombin index had a diagnostic accuracy of 91.1 % and 89.7 %, respectively in the whole population. Finally, a significant negative correlation was found between hyaluronate and the prothrombin index (r =- 0.86, P <0.0001). CONCLUSIONS: Using only hyaluronate and the prothrombin index, 9 out of 10 alcoholic patients can be correctly classified according to the severity of liver fibrosis.  相似文献   
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复制高胆固醇血症(hypercholesterolemia,HC)兔模型,取其血液分离单核细胞(monocytes,MC),培养于含或不含伴刀豆球蛋白A(concanavalinA,ConA)的无血清DME/F12培养基中,收集不同条件的MC条件培养基(MC-conditionedmedium,MC-CM)。并检测其促有丝分裂活性。结果表明,经ConA激活的HC兔的MC-CM刺激3H-TdR掺入NIH3T3  相似文献   
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OBJECTIVE: To assess the diagnostic accuracy of a rapid urine-screening test (Multistix8SG) for spontaneous bacterial peritonitis (SBP) in cirrhotic patients. METHODS: Seventy-two consecutive patients (44 males, 28 females; mean age 61.6 years) with cirrhosis and ascites were included in the study. A diagnostic paracentesis was performed on hospital admission in all patients and 2 days after antibiotic treatment in the case of SBP (polymorphonuclear [PMN] count over 250/mm in ascitic fluid). Each fresh sample of ascitic fluid was also tested using the Multistix8SG urine test, and the results were scored as negative, trace or positive. RESULTS: Nine of the 72 patients had SBP and the Multistix8SG urine test was positive. After 48 h of antibiotic therapy, the PMN count of three of these nine patients was still above 250/mm and the Multistix8SG test remained positive. In three other patients with SBP, the PMN count dropped below 250/mm and the Multistix8SG test result had become negative. Two of the nine SBP patients died before 48 h, and paracentesis was not performed in the ninth case. In the other 63 patients, the PMN count in ascitic fluid was below 250/mm; the Multistix8SG test revealed 17 trace results and 46 negative results. At the threshold of 250 PMN/mm in ascitic fluid, this test had a sensitivity and a specificity of 100%. CONCLUSION: A positive Multistix8SG urine test result in ascitic fluid appears to be an indication for antibiotic treatment.  相似文献   
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