Nitric Oxide Synthase Expression in Macrophages of Histoplasma capsulatum-Infected Mice Is Associated with Splenocyte Apoptosis and Unresponsiveness

Splenic macrophages from Histoplasma capsulatum-infected mice express inducible nitric oxide synthase (iNOS), and the iNOS expression correlates with severity of the infection. We examined whether production of NO is responsible for apoptosis and the anti-lymphoproliferative response of splenocytes from mice infected with H. capsulatum. In situ terminal deoxynucleotidyl transferase nick end labeling revealed apoptotic nuclei in cryosections of spleen from infected but not normal mice. Splenocytes of infected mice were unresponsive to stimulation by either concanavalin A or heat-killed H. capsulatum yeast cells. Splenocyte responsiveness was restored by addition to the medium of N^G-monomethyl-l-arginine, a known inhibitor of NO production. The proliferative response of splenocytes from infected mice was also restored by depletion of macrophages or by replacement with macrophages from normal mice. In addition, expression of iNOS returned to its basal level when the animals had recovered from infection. These results suggest that suppressor cell activity of macrophages is associated with production of NO, which also appears to be an effector molecule for apoptosis of cultured splenocytes from infected mice.

Nitric oxide (NO) has been reported to induce apoptosis in many cells including smooth muscle cells (20), oligodendrocytes (27), pancreatic β cells (11), melanoma cells (35), thymocytes (7), B lymphocytes (4), and macrophages (2). Fehsel et al. recently demonstrated apoptosis in freshly isolated thymocytes after exposure to NO (7). In the same report, they also showed apoptotic foci in close proximity to blood vessels after lipopolysaccharide treatment. Capillary endothelial and dendritic cells adjacent to apoptotic foci stained strongly for inducible nitric oxide synthase (iNOS), suggesting that NO may be the mediator for thymic apoptosis (7). Data from another laboratory also showed that cloned thymic stromal cell monolayers eliminate thymocytes in vitro through production of NO (26). Furthermore, apoptosis has been suggested as a mechanism by which the immune system replenishes itself and maintains homeostasis (30).The dimorphic fungus Histoplasma capsulatum is a facultative intracellular pathogen of the macrophage (32). Although it is not an obligate intracellular pathogen, the organism is found almost exclusively inside host cells during histoplasmosis (5). In our in vitro studies, H. capsulatum exhibits uninhibited growth in normal unstimulated murine macrophages (32). In activated macrophages, either peritoneal macrophages and cells from the Raw 264.7 line stimulated by gamma interferon (IFN-γ) or splenic macrophages stimulated by IFN-γ and lipopolysaccharide, growth of the fungus is inhibited (13, 18, 32). Furthermore, the anti-histoplasma activity of macrophages is dependent on the expression of iNOS and the production of NO (14, 18). However, the significance of NO production in immunoregulation of histoplasmosis is not clearly defined.In this study, we examined whether NO can act as a regulator of apoptosis in lymphoproliferative responses of splenocytes from H. capsulatum-infected mice. We showed that iNOS was induced in splenic macrophages during active infection and the expression of iNOS coincided with active infection. We also observed by in situ terminal deoxynucleotidyl transferase (TdT) nick end labeling (TUNEL) of spleen sections that apoptosis occurred in immune cells in the spleens of infected mice but was minimal in control mice. The link between apoptosis and NO production was established by inclusion of N^G-monomethyl-l-arginine (NMMA) in the culture medium. Inhibition of NO production reduced the amount of apoptosis in splenocyte culture. Thereby, we also confirmed the findings of Zhou et al. (36) that production of NO by splenocytes of H. capsulatum-infected mice suppressed the splenic lymphocyte proliferative response. In addition, we showed that macrophages were mediators of splenocyte unresponsiveness through the NO that they produced and that NO production was associated with apoptotic changes in cultured splenocytes from infected mice.     

Effect Of Pulsatile Electromagnetic Fields On Blood Viscosity And Coagulation

Ithasbeenprovedthatanumberofdiseasesarerelatedwithabnormalityofbloodviscosityandcoagulationinclinicalresearch.Bloodhyperviscosityandhypercoagulationcauseandaccelearatethedevelopmentofcertaindiseases,deathrateofsomeofwhicharerisingwithyears.Lookingforawaytoreducebloodviscosityandrestrainfasterandstrongercoagulationbecomesasubjectdrawingmoreattention.Theproperseofthisresearchwastofindsuchaway.Intheblood,therearechargrdRBC,WBC,PLT,inorganicions,sothattheremustbesensitiveandcomplicatedresponse…     

pp~(60c-src(+))在神经生长端的表达及其意义

目的　探索 pp60c-src( + ) 在神经生长端的表达特征及其生理意义。方法　用免疫细胞化学方法检测 pp60c-src( + ) 在初代培养鸡胚脊神经节细胞内的分布特征。结果　pp60c -src( + ) 的免疫活性分布在神经细胞的细胞膜下、核周体、神经突起 ;在生长端体部和丝状伪足 ,pp60c -src( + ) 的免疫活性较强 ,少数免疫活性较弱。在伸长的突起上有时可见 pp60c-src( + ) 免疫活性分布在串珠样膨体上。结论　pp60c-src( + ) 参与生长端的运动和生长 ;在生长端分化、神经生长过程中 ,pp60c-src( + ) 的调控作用具有时空特异性     

C1q受体研究进展

补体分子C1q具有调节各种细胞反应的能力.近年,随着C1q功能研究的深入,发现许多细胞内或者细胞表面存在结合C1q的蛋白或者受体,如C1qRp、gC1qbp、C1qRo2-、钙网素/CRT/cC1qR胶凝素受体、CR1.其中某些蛋白除结合C1q外还结合其它配体.     

Paternal mosaicism and hereditary angioedema in a Taiwanese family.

BACKGROUND: Hereditary angioedema (HAE) is a rare disorder characterized by recurrent attacks of localized subcutaneous or submucosal edema. It is inherited in an autosomal dominant fashion and caused by a deficiency of C1 inhibitor (C1 INH). Most patients with HAE have an absolute deficiency of C1 INH (type I HAE), whereas the rest (approximately 15%) synthesize a dysfunctional C1 INH protein (type II HAE). Mosaicism is rare in HAE. OBJECTIVE: To describe the clinical manifestations, laboratory findings, and molecular genetic studies in a Taiwanese family with type I HAE with paternal mosaicism. METHODS: A family that included a 34-year-old man (index patient) and his 25-year-old brother who both had recurrent peripheral angioedema was evaluated. A younger sister had died of an unexplained cause at 18 years of age. We analyzed blood levels of C3, C4, and C1 INH and sequenced the SERPING] (C1NH) gene that codes for C1 INH in 5 family members, including the parents and 3 brothers. RESULTS: The 4 men in the family had a novel mutation c.3_73del, p.N1fsX34 in exon 3 of the C1INH gene, resulting in C1 INH deficiency. Although the father carried this mutant gene, he had normal serum levels of C1 INH. Based on quantitative analysis of allele dosage by DNA fragment analysis (GeneScan), the father was determined to have genetic mosaicism. CONCLUSION: Parental mosaicism is a possible explanation for normal C1 INH plasma concentrations in both parents despite clinically apparent HAE in the children.     

Analysis of proteins and lipopolysaccharides from Chinese isolates of Coxiella burnetii with monoclonal antibodies.

Four Coxiella burnetii isolates in China and two reference strains were compared by SDS-PAGE and immunoblotting. The SDS-PAGE profiles of whole cells and LPS of Chinese isolates Qiyi, Xinqiao, and YS-8 were found closely related to Henzerling strain, and different from the Grita strain. In immunoblot assay of LPS and proteinase K-digested whole rickettsiae minor differences were seen in polysaccharide structure among the Chinese isolates by phase I monoclonal antibody. The present results suggest that the strains reported here may be divided into three groups according to the polysaccharide structure: Xinqiao and Henzerling strains (1), YS-8 and Grita (2), and Qiyi (3).     

Effects of establishing a financing scheme for outpatient care on inpatient services: empirical evidence from a quasi-experiment in China

The European Journal of Health Economics - The relationship between outpatient and inpatient care is central to the current healthcare reform debate especially in developing countries. Despite the...     

思美泰治疗妊娠胆汁淤积症的疗效观察

妊娠胆汁淤积症(ICP)是一种在妊娠期出现的以皮肤搔痒和黄疸为特征的较常见的并发症, 易导致早产、胎儿窘迫、死胎、新生儿死亡及产后出血等,严重影响围产儿安 全。思美泰是一种治疗ICP的新药,疗效显著。现将1998年10月～2000年10月收治的60例ICP 随机应用思美泰和门冬氨酸钾镁治疗,报道如下： 1　资料和方法 1.1　临床资料来源 　　60例ICP均为本院住院病人,年龄22～35岁,平均26.7岁,初产妇52人,经产妇8人,均有皮 肤搔痒和肝功能异常,肝类病原学指标全部阴性,并排除妊高征肝损,急性脂肪肝及药物性 肝炎。随机分为2组,2组病例年龄、病情、肝功能损害程度和孕周无显著差异。 1.2　治疗方案 　　治疗组采用德国基诺药厂生产的思美泰注射液1g,由稀释液溶解加入5%葡萄糖注射液250ml 中静滴,每日1次,持续4周。对照组采用杭州民生药厂生产的门冬氨酸钾镁注射液30ml加入 5%葡萄糖注射液250ml中静滴,每日1次,持续4周。2组基础药物相同,包括Vitc、复方益 肝灵及中药茵陈汤。 1.3　疗效判断 　　疗效判断标准分为3组：①显效：用药后患者症状、体征明显改善,生化(谷丙转氨酶、总 胆红素、总胆汁酸)恢复正常或降至治疗前基础的50%以上;②有效：症状体征改善,生化指 标有下降,但未降至基础的50%;③无效：症状体征及生化指标没有改善或有加重者。显效 和有效合计称为有效病例,据此计算有效率。