B lymphocytes secreting IgG linked to latent transforming growth factor- beta prevent primary cytolytic T lymphocyte responses

B lymphocytes secreting IgG linked to latent transforming growth factor (TGF)-beta (IgG-TGF-beta) prevent cytolytic T lymphocyte (CTL) responses to unrelated antigens in mixed lymphocyte cultures (MLC) so long as resting resident macrophages and functional Fc receptors are present. This was shown using IgG-secreting plaque-forming cells (PFC) to sheep erythrocytes (SRBC) obtained from popliteal lymph nodes of mice injected repeatedly in foot pads with SRBC. Remarkably, as few as approximately 300 PFC prevented CTL responses of 5 x 10(5) normal syngeneic spleen cells in MLC. Supranatants of short-term cultures of PFC also prevented CTL responses, and suppression was prevented by eliminating or dissociating IgG and TGF-beta present in supranatants or by antibody against active TGF-beta. Furthermore, the latency- associated peptide of latent TGF-beta was detected in approximately 10% of foci of IgG captured from single PFC, indicating that at least some B lymphocytes secrete IgG-TGF-beta as a complex. Resting resident macrophages (which do not produce latent TGF-beta) and functional Fc receptors were required for suppression, consistent with idea that IgG- TGF-beta is taken up through Fc receptors for IgG and that active TGF- beta, cleaved from latent TGF-beta of the complex, is delivered directly to potentially responding CTL. If CTL responses in man are similarly regulated by B lymphocytes, then an ongoing B cell response in patients with chronic viral infections or bearing immunogenic cancers may prevent effective therapeutic vaccination.      

以光敏性癫痫为主要表现的肌阵挛性癫痫伴肌肉破碎红纤维综合征一家系分析

目的研究1个以光敏性癫痫为主要表现的肌阵挛性癫痫伴肌肉破碎红纤维综合征(MERRF)家系的临床特点、遗传学特征。方法整理一个以光敏性癫痫为主要表现的肌阵挛性癫痫伴肌肉破碎红纤维综合征家系的临床表现、辅助检查及影像学资料,分析其临床特点和遗传特征。结果该家系呈母系遗传,共4人(包括先证者3个同辈,1个子代)出现肌阵挛表现,先证者以光敏性癫痫为主要表现,其肌肉活检可见典型的破碎红纤维(RRF),先证者的线粒体DNA提示8344位点由A突变为G。结论 MERRF家系少见,可以光敏性肌阵挛癫痫为主要表现。     

原发性肉碱缺乏致脂质沉积性肌病的临床与病理特点

目的 分析原发性肉碱缺乏致脂质沉积性肌病（LSM）的临床与病理特点。方法 回顾性分析4例可能LSM患者的临床资料。结果 本组患者为亚急性或慢性起病，主要表现为近端肌无力，疲劳不能耐受；血清肌酶有不同程度的升高；肌电图示肌源性损害；病理检查示肌纤维内可见大量细小空泡和裂隙形成；MGT染色无破碎红纤维，油红O染色显示空泡为大量脂滴充填；受累纤维以Ⅰ型纤维为主。电镜证实肌纤维内脂滴堆积，可伴有线粒体的轻度增多。改善能量和糖皮质激素治疗有效。结论原发性肉碱缺乏致LSM是一种以易疲劳和肌无力为主要临床表现的脂质代谢障碍性肌病，病理改变以肌纤维内脂滴堆积为主，一般不伴有线粒体结构的明显异常。糖皮质激素治疗可获得良好疗效。     

Charcot-Marie-Tooth病患者血清PMP22抗体、IL-6和TNF-α水平的研究

目的检测Charcot-Marie-Tooth(CMT)病患者血清周围髓鞘蛋白22(PMP22)抗体、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)水平,以探讨是否有免疫学机制参与CMT的病理生理过程。方法以人工合成PMP22胞外片段作为多肽抗原,用双抗体酶标法检测9名CMT1A患者和7名CMTX1患者血清PMP22抗体,同时检测IL-6和TNF-α水平;11名吉兰-巴雷综合征(GBS)患者和20名性别、年龄相匹配的正常人作对照。结果55.6%CMT1A患者和57.1%CMTX1患者PMP22抗体阳性,63.6%GBS患者和10%正常对照PMP22抗体阳性。正常对照组和CMT患者血清IL-6和TNF-α水平差异无统计学意义(P>0.05)。结论CMT1A患者PMP22抗体阳性与性别、年龄和病程均无关,但在CMTX1家系中,该抗体与性别相关(男性患者阳性),这可能是导致CMTX1家系中男性患者临床症状明显重于女性患者的原因之一。在CMT1A中,PMP22抗体的存在可能是对神经损伤的继发性反应而不是原发性病理过程,在CMTX1家系中存在继发性的免疫过程。此症可能不存在细胞因子介导的免疫损害。     

The lipoprotein-associated coagulation inhibitor that inhibits the factor VII-tissue factor complex also inhibits factor Xa: insight into its possible mechanism of action

Blood coagulation is initiated when plasma factor VII(a) binds to its essential cofactor tissue factor (TF) and proteolytically activates factors X and IX. Progressive inhibition of TF activity occurs upon its addition to plasma. This process is reversible and requires the presence of VII(a), catalytically active Xa, Ca2+, and another component that appears to be associated with the lipoproteins in plasma, a lipoprotein-associated coagulation inhibitor (LACI). A protein, LACI(HG2), possessing the same inhibitory properties as LACI, has recently been isolated from the conditioned media of cultured human liver cells (HepG2). Rabbit antisera raised against a synthetic peptide based on the N-terminal sequence of LACI(HG2) and purified IgG from a rabbit immunized with intact LACI(HG2) inhibit the LACI activity in human serum. In a reaction mixture containing VIIa, Xa, Ca2+, and purified LACI(HG2), the apparent half-life (t1/2) for TF activity was 20 seconds. The presence of heparin accelerated the initial rate of inhibition threefold. Antithrombin III alpha alone had no effect, but antithrombin III alpha with heparin abrogated the TF inhibition. LACI(HG2) also inhibited Xa with an apparent t1/2 of 50 seconds. Heparin enhanced the rate of Xa inhibition 2.5-fold, whereas phospholipids and Ca2+ slowed the reaction 2.5-fold. Xa inhibition was demonstrable with both chromogenic substrate (S-2222) and bioassays, but no complex between Xa and LACI(HG2) could be visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Nondenaturing PAGE, however, showed that LACI(HG2) bound to Xa but not to X or Xa inactivated by diisopropyl fluorophosphate. Thus, LACI(HG2) appears to bind to Xa at or near its active site. Bovine factor Xa lacking its gamma-carboxyglutamic acid-containing domain, BXa(-GD), through treatment with alpha-chymotrypsin, was used to further investigate the Xa requirement for VIIa/TF inhibition by LACI(HG2). LACI(HG2) bound to BXa(-GD) and inhibited its catalytic activity against a small molecular substrate (Spectrozyme Xa), though at a rate approximately sevenfold slower than native BXa. Preincubation of LACI(HG2) with saturating concentrations of BXa(-GD) markedly retarded the subsequent inhibition of BXa. The VII(a)/TF complex was not inhibited by LACI(HG2) in the presence of BXa(-GD), and further, preincubation of LACI(HG2) with BXa(-GD) slowed the inhibition of VIIa/TF after the addition of native Xa. The results are consistent with the hypothesis that inhibition of VII(a)/TF involves the formation of a VIIa-TF-XA-LACI complex that requires the GD of XA.(ABSTRACT TRUNCATED AT 400 WORDS)     

住院患者对护理职业的认知调查

目的 了解住院患者对护理职业的认知状况,增强护士职业自豪感.方法 自行设计住院患者对护理职业认知调查问卷,对197例住院患者进行调查.结果 认为护理工作包括发药打针、健康指导和心理护理的患者占49.24%;认为护士在治疗康复中所起的作用重要和非常重要者占85.28%、一般和不重要占14.72%;认为护士学历应为大专及以上学历的患者占87.82%,中专占12.18%;认为医生和护士是平等关系的患者占76.65%、从属关系占18.78%;认为护理职业发展前途好和很好的患者占79.19%.不好和很差占5.58%.不同性别、年龄、文化程度住院患者对护理职业的评价比较,差异无统计学意义(均P>0.05);有选择护理职业意愿者56.85%.不愿意选择43.15%;112例住院患者愿意选择护理职业的主要原因是受人尊敬(66.96%)和工作稳定(29.46%).结论 住院患者正在逐步正视护理职业.护理工作者应提高职业自豪感,热爱护理工作,全心全意为人类的健康服务,为护理事业的发展做出贡献,以赢得应有的社会地位.