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排序方式: 共有485条查询结果,搜索用时 21 毫秒
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Neutrophil Oxygen Radical Production by Dialysis Membranes 总被引:1,自引:0,他引:1
The ability of different dialysis membranes to activate polymorphonuclearneutrophil oxygen radical production was investigated with chemiluminescence.All the six membranes, namely cuprophan, cellulose acetate,polycarbonate, polysulphone, polyacrilonitrile and polymethylmethacrylatewere able to interact with neutrophils and stimulate their oxygenradical production, the highest responses being seen with polyacrilonitrile,polymethylmethacrylate and polycarbonate. To analyse the roleof complement in this interaction, fresh plasma, heat inactivatedand zymosan-activated plasma were added: with fresh plasma oxygenradical production was stimulated on cuprophan, cellulose acetateand polysulphone, not modified on polycarbonate, and decreasedon polyacrilonitrile and polymethylmethacrylate. With heat-inactivatedplasma, the responses were decreased or abrogated on all themembranes except polycarbonate and polymethylmethacrylate, whereaswith zymosanactivated plasma similar responses to fresh plasmawere observed. In addition, when plasma was used to precoatthe membrane, cuprophan, cellulose acetate and polysulphonedisclosed an enhanced neutrophil oxidative burst, while precoatedpolyacrilonitrile and polymethylmethacrylate were less stimulatorythan uncoated membranes. In contrast the precoating of polycarbonatedid not modify oxygen radical production. These data suggestthat neutrophil activation occurs by direct membrane neutrophilinteraction. Plasmatic factors modulate this interaction butcomplement seems involved on cellulosic and polysulphone membranesonly. Therefore, it appears that oxygen radicals produced fromcontact of neutrophils with the dialysis membrane might playan initial and/or additional role in the events occurring atthe initiation of haemodialysis. 相似文献
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Marilyn Rodney Carla Clasen Gloria Goldman Ronald Markert Donna Deane 《Journal of community health》1998,23(5):371-381
The title Community Health Advocate (CHA) is one of thirty or more titles used throughout the world for an indigenous outreach worker who is trusted and respected in his or her community and who serves as a bridge between peers and health professionals. In 1992, the Center for Healthy Communities in Dayton, Ohio developed a program to train as Advocates people indigenous to the communities in which they would be working. Since the first CHAs began work in January 1993, the effectiveness of the program has been evaluated from three perspectives: the Community Health Advocates, the managers directors of the community sites at which the CHAs work, and the clients with whom the CHAs work. Advocates indicated that the training program adequately prepared them for their roles and functions. They also identified systematic frustrations and barriers that made it more difficult for them to perform their job. Community site directors and community leaders indicated that the CHAs were considered a positive force in meeting client needs and facilitating independence, and were very effective in outreach and coordination of resources. A survey of CHA clients revealed an overwhelmingly positive response to the Advocate's work, validating the belief that CHAs can fill an important niche in the health care community. The three evaluation processes described in this paper helped to document the need for and the effectiveness of this program and can serve as a model for similar programs. 相似文献
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Koc S Kather A Markert UR Dürst M Schneider A Kaufmann AM 《American journal of reproductive immunology (New York, N.Y. : 1989)》2003,50(3):243-253
PROBLEM: The choriocarcinoma cell line Jeg3 suppresses immunity in vitro by secretion of soluble factors like leukemia inhibitory factor suppressing leukocyte activation. The cells lack expression of classical human leukocyte antigen (HLA)-A and -B alleles but express some HLA-C, and non-classical HLA-G and -E. Upon binding to killing inhibitory receptor on natural killer (NK) cells, HLA-G prevents activation of cytolytic activity. We investigated whether Jeg3 cells are capable of immune stimulation after complementation with classical HLA and T cell costimulatory signal CD80. METHOD OF STUDY: Jeg3 cells were transduced to express HLA-A*0201 and/or CD80. Parental Jeg3 or transfectants Jeg3-A2, Jeg3-CD80 or Jeg3-CD80-A2 were used to stimulate allogeneic resting and activated peripheral blood lymphocytes (PBL). The different cell lines were loaded with a HLA-A2-restricted Epstein-Barr virus (EBV) recall antigen peptide epitope and antigen presenting ability was examined. T cell lines specific for Jeg3 and transfectants were generated from HLA-A2 matched and nonmatched donors and compared for expansion, phenotypes and cytolytic activity. RESULTS: While all Jeg3 cell lines induced only marginal proliferation of resting T cells, phytohemagglutinin (PHA)-activated T cells were stimulated by CD80 or CD80-A2 expressing Jeg3. Only the transfectant Jeg3-CD80-A2 was capable of specific T cell stimulation by EBV recall antigen presentation. T cell lines of HLA-A2 non-matched donors stimulated with the Jeg3 transfectants showed significant expansion only when HLA-A2 and the costimulus CD80 were present. T cells from HLA-A2 positive donors did not expand significantly or differentially. No NK cells grew under any condition. In Jeg3-CD80-A2 stimulated T cells lines CD8+ cells expanded preferentially. These T cells exerted cytolytic activity toward all Jeg3 cell lines. CONCLUSION: Our data suggest that, in spite of immunosuppressive mechanisms, proliferative and cytolytic T cell responses are induced by Jeg3 cells when classical HLA- and/or costimulatory signals are present on the cells. 相似文献
6.
Kather A Chantakru S He H Minhas K Foster R Markert UR Pfeffer K Croy BA 《Immunology》2003,108(3):338-345
Gene ablation studies in mice indicate that lymphotoxin (LT)alpha, LTbeta and LTbetaR are essential for the genesis of lymph nodes (LN), normal structural development of peripheral lymphoid tissues and the differentiation of natural killer (NK) cells. LTbetaR binds to the heterotrimeric cytokines LTalpha1beta2 and LIGHT. LTs also regulate stromal cell expression of lymphocyte homing chemokines. Uterine decidualization in normal (+/+) mice is accompanied by the appearance and maturation of large numbers of uterine NK (uNK) cells that differentiate from precursors mobilized to the uterus from secondary lymphoid tissues. uNK cells accumulate in a transient, lymphocyte-rich region known as the metrial gland or, more recently, the mesometrial lymphoid aggregrate of pregnancy (MLAp). To determine if LTs contribute to development of the MLAp, and to the differentiation and/or localization of uNK cells, a histological study was undertaken of implantation sites from LTalpha null, LTbetaR null and gestation day-matched, normal mice. Implantation sites from the gene-ablated mice contained abundant numbers of uNK cells that localized appropriately. This indicates that the stromally derived molecules supporting NK cell differentiation in the uterus differ from those used in secondary lymphoid organs. 相似文献
7.
Relationship between neutrophil-mediated oxidative injury during acute experimental pyelonephritis and chronic renal scarring. 总被引:2,自引:0,他引:2
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Previous experiments with rats have suggested that pyelonephritic scarring after acute ascending Escherichia coli pyelonephritis partly results from excessive polymorphonuclear leukocyte (PMN) infiltration and activation in the kidney parenchyma. We have studied the role of PMN oxidative metabolism in generating tissue injury during acute pyelonephritis. Rats with acute pyelonephritis were treated with dapsone (25 mg/kg twice daily for 3 days), a compound known to prevent PMN oxidant damage. In vitro, levels of dapsone easily achieved in vivo inhibited myeloperoxidase (MPO)-mediated reactions involving the oxidation of halides to reactive cytotoxic hypohalites (such as MPO-mediated iodination and luminol-enhanced chemiluminescence). In contrast, dapsone had no effect on superoxide production, lysosomal enzyme release, or bacterial killing by activated PMN. In vivo, dapsone treatment had no significant effect on acute pyelonephritis with respect to (i) bacterial counts, (ii) inflammatory swelling, and (iii) PMN infiltration. However, dapsone-treated animals sacrificed 2 months after acute pyelonephritis had a 65% reduction of renal scars when compared with controls. Since dapsone had no antibacterial effect, this protection is compatible with the hypothesis that dapsone prevented oxidant-generated tissue injury due to the extracellular release of the MPO system by activated PMN during acute suppurative pyelonephritis. 相似文献
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Raoud Marayati Laura V. Bownes Colin H. Quinn Nikita Wadhwani Adele P. Williams Hooper R. Markert Venkatram Atigadda Jamie M. Aye Jerry E. Stewart Karina J. Yoon Elizabeth A. Beierle 《Journal of pediatric surgery》2021,56(6):1165-1173
IntroductionThe poor therapeutic efficacy seen with current treatments for neuroblastoma may be attributed to stem cell-like cancer cells (SCLCCs), a subpopulation of cancer cells associated with poor prognosis and disease recurrence. Retinoic acid (RA) is a differentiating agent used as maintenance therapy for high-risk neuroblastoma but nearly half of children treated with RA relapse. We hypothesized that 6-Methyl-UAB30 (6-Me), a second-generation rexinoid recently developed with a favorable toxicity profile compared to RA, would reduce cancer cell stemness in human neuroblastoma patient-derived xenografts (PDXs).MethodsCells from three neuroblastoma PDXs were treated with 6-Me and proliferation, viability, motility, and cell-cycle progression were assessed. CD133 expression, sphere formation, and mRNA abundance of stemness and differentiation markers were evaluated using flow cytometry, in vitro extreme limiting dilution analysis, and real-time PCR, respectively.ResultsTreatment with 6-Me decreased proliferation, viability, and motility, and induced cell-cycle arrest and differentiation in all three neuroblastoma PDXs. In addition, 6-Me treatment led to decreased CD133 expression, decreased sphere-forming ability, and decreased mRNA abundance of Oct4, Nanog, and Sox2, indicating decreased cancer cell stemness.Conclusions6-Me decreased oncogenicity and reduced cancer cell stemness of neuroblastoma PDXs, warranting further exploration of 6-Me as potential novel therapy for neuroblastoma. 相似文献
10.
Testis-specific expression of a metallothionein I-driven transgene correlates with undermethylation of the locus in testicular DNA. 总被引:2,自引:0,他引:2
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