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991.
Effect of osmotic protection on nucleated cell killing by C5b-9: cell death is not affected by the prevention of cell swelling 总被引:2,自引:0,他引:2
Formation of C5b-9 channels in the plasma membrane can lead to erythrocyte lysis or nucleated cell death. Lysis of erythrocytes by complement occurs as a result of colloid osmotic swelling and rupture of the plasma membrane, due to the unregulated flux of ions and water through C5b-9 channels. This colloid osmotic mechanism of lysis is largely based on the evidence that the extent of hemolysis is reduced, when macromolecules are placed in the medium to balance the osmotic gradient created by intracellular macromolecules, which are too large to diffuse through complement channels. The role of colloid osmotic deregulation, as a cause of nucleated cell killing by C5b-9, however, has been recently questioned [Kim S., Carney D. F. and Shin M. L. J. Immun. 138, 1530 (1987)]. In the present study, we investigated the effect of osmotic protection, with an 81,000 mol. wt dextran or bovine serum albumin, on Ehrlich cell killing by complement channels. The results indicated that prevention of cell swelling by dextran did not reduce the extent or rate of nucleated cell killing by either small (C5b-9l), or large (C5b-9m), complement channels when assessed by vital dye stain. The release of cytoplasmic lactate dehydrogenase as an alternative measure of cell death, however, was retarded and/or reduced, in the presence of dextran or albumin, at concns that prevented cell swelling. These results indicate that C5b-9 can kill nucleated cells effectively, in the absence of colloidal osmotic cell swelling, and that release of cytoplasmic macromolecules may not be a reliable indicator of cell death, when osmotic protectants are employed. 相似文献
992.
993.
E DelGuercio J Greco K E Kim J Chinitz C Swartz 《The New England journal of medicine》1973,289(13):678-679
994.
Yoon HJ Kim H Kim HL Lee SG Zheng SH Shin JH Lim CS Kim S Lee JS Lee DS Kim YS 《Clinical genetics》2002,62(2):128-134
In order to investigate the interdependent action of the insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene and polymorphism in exon 11 (C1136-->T; Ala379Val) of the platelet-activating factor acetylhydrolase (PAF-AH) gene, which encodes a functional antagonist of PAF, on the progression of immunoglobulin A (IgA) nephropathy, we analysed both polymorphisms in patients with primary IgA nephropathy, who were followed-up for longer than 3 years. During the follow-up (87.3 +/- 50.0 months), the disease progressed in 38 of the 191 patients (19.9%). The D allele of the ACE gene in the absence of the T allele of the PAF-AH gene did not affect the prognosis [odds ratio (OR), 3.6; 95% confidence interval (CI), 0.8-16.4] and neither did the T allele in the absence of the D allele (OR, 3.0; 95% CI, 0.4-24.2). However, the presence of both was a significant prognostic factor (OR, 6.6; 95% CI, 1.4-31.3). After adjusting for other risk factors, the presence of both proved to be an independent risk factor (OR, 4.5; 95% CI, 1.6-12.7). These results suggest that the interdependent effects of ACE and PAF-AH polymorphisms on the progression of IgA nephropathy might be more important than the effect of the individual polymorphisms. 相似文献
995.
Fas (APO-1/CD95) ligand and Fas expression in renal cell carcinomas: correlation with the prognostic factors 总被引:3,自引:0,他引:3
Kim YS Kim KH Choi JA Lee JH Kim HK Won NH Kim I 《Archives of pathology & laboratory medicine》2000,124(5):687-693
BACKGROUND AND OBJECTIVE: Fas ligand (FasL, CD95L) is a type II transmembrane protein of the tumor necrosis factor family that induces cells to send an apoptotic signal to cells expressing Fas (CD95, APO-1). It has been shown that cancers have a dysregulated expression of Fas and FasL system, conferring a survival advantage. It is important to understand FasL and Fas expression in tumors, because the growth of cancer might be controlled by Fas-mediated apoptosis. METHODS: The expressions of FasL and Fas were studied by immunohistochemical analyses in 51 cases of renal cell carcinomas and the adjacent normal renal tissues, respectively. In addition, their expressions were compared with prognostic factors, such as tumor size, nuclear grade, TNM stage, and histologic types. RESULTS: In nonneoplastic renal tissues, FasL was expressed in all nephron segments, whereas Fas also expressed in all tubules, except for glomeruli. In renal cell carcinomas, FasL protein was detected in 50 (98.0%) of 51 cases, whereas Fas expressed in 38 (74.5%) of 51 cases. In fact, the immunostaining of Fas was less intense than that in the adjacent normal segments of all cases. The staining pattern showing both high expression of FasL and low expression of Fas was found in 36 (70.6%) (P = .04) of 51 cases, most of which were Fuhrman grade 2 or 3 tumors. However, the expression pattern did not correlate statistically with the tumor size, histologic type, or clinical stage. On the other hand, most grade 4 tumors displayed high expression of both FasL and Fas (P<.001). CONCLUSION: These data indicate that high expression of FasL and low expression of Fas protein in renal cell carcinomas may play a role in evading surveillance of the immune system. In addition, the FasL and Fas expressions appear to have a therapeutic implication for high-grade tumors rather than a prognostic one. 相似文献
996.
Pathogenic immunity in Theiler's virus-induced demyelinating disease: a viral model for multiple sclerosis 总被引:2,自引:0,他引:2
Kim BS Palma JP Inoue A Koh CS 《Archivum immunologiae et therapiae experimentalis》2000,48(5):373-379
Multiple sclerosis involves inflammatory immune responses in the central nervous system (CNS) and is considered as an autoimmune disease potentially associated with viral infection. The majority of experimental models rely heavily on the autoimmune components since similar diseases can be induced following immunization with various myelin antigens. A very attractive alternative model is the Theiler's murine encephalomyelitis virus-induced demyelinating disease. This disease is primarily a CD4+ T cell-mediated, inflammatory demyelinating disease induced following viral infection. Virus-specific inflammatory Th1 cell responses, rather than cytotoxic T lymphocyte response, play a critical role in the pathogenic immune responses. The major pathogenic epitopes have been identified and these are correlated with a Th1 type response to the epitopes following viral infection. In addition, the initial virus-specific immune response is followed by the autoimmune responses to myelin antigens. Assessment of cytokines produced locally in the CNS during the course of disease suggests involvement of inflammatory cytokines in the disease. Furthermore, the manipulation of inflammatory cytokine levels by administration of either recombinant cytokines or antibodies to the cytokines strongly influences the induction and/or progression of disease, supporting the importance of these inflammatory cytokines in this virus-induced demyelinating disease. 相似文献
997.
Stress alters immune function and affects different immune cell populations in different ways. The authors examined whether psychological stress has different effects on the production of macrophage, T-helper 1(Th1) cell, and T-helper 2(Th2) cell-derived cytokines. Forty-two college students were recruited and their blood was sampled on the day they were to take a stressful academic examination and again 4 weeks after the examination. The stress from the academic examination significantly increased IL-1 beta, IL-6, and IL-10 and decreased IFN-gamma production. These findings suggest that examination stress may increase Th2 cell-mediated humoral immunity and macrophage activities and may decrease Th1 cell-mediated cellular immunity. 相似文献
998.
Fracture behavior of dental composite resins. 总被引:2,自引:0,他引:2
Fracture toughness (KIC), critical stress intensity factor, and bending strength of 3 types of commercially available dental composite resins (macrofilled, hybrid and microfilled type) were determined using three point bend specimens. Acoustic Emission (AE), which is the generation of elastic wave due to the release of energy from the localized sources in material, was also detected during the fracture toughness test. Fracture surfaces were examined by scanning electron microscope. The fracture toughness values, AE patterns, and the nature of fracture surface were analyzed to understand fracture behavior of dental composite resins and fracture mechanism for each dental composite resin are proposed. 相似文献
999.
1000.
Large amounts (200 mg per liter of culture supernatant fluid) of highly purified staphylococcal soluble delta hemolysin were obtained by adsorption to and selective elution from hydroxyapatite followed by exhaustive dialysis against water, concentration by polyvinylpyrrolidone or polyethylene glycol 20,000 dialysis, and a final water dialysis. No carbohydrate, phosphorus, or inactive 280-nm absorbing material was detected in the preparation; however, analysis by density gradient centrifugation, gel filtration, analytical ultracentrifugation, carboxymethyl cellulose chromatography, polyacrylamide disc gel electrophoresis, isoelectric focusing, and electron microscopy revealed that the lysin was molecularly heterogeneous. The preparation contained an acidic fibrous lysin (S20,w of 11.9) and a basic lysin component composed of a population of granular aggregates of various sizes, with a maximum S20,w of approximately 4.9. No other staphylococcal products were detected in the preparation. The lysin was active against erythrocytes from many animal species and acted synergistically with staphylococcal beta hemolysin against sheep erythrocytes. It was soluble in chloroform-methanol (2:1), was inactivated by various phospholipids, normal sera, and proteolytic enzymes, but was partially resistant to heat inactivation. Activity was not affected by Ca2+, Mg2+, citrate, ethylenediaminetetraacetic acid, or cysteine. The lysin preparation also disrupted bacterial protoplasts and spheroplasts, erythrocyte membranes, lysosomes, and lipid spherules, was growth-inhibitory for certain bacteria, and clarified egg yolk-agar. Large amounts produced dermonecrosis in rabbits and guinea pigs. The minimum lethal intravenous dose for mice and guinea pigs was approximately 110 and 30 mg/kg, respectively. 相似文献