The Treatment of Septicemia in Pacemaker Patients

The authors analyzed the data of seven patients who had undergone open heart surgery because of pacemaker endocarditis in the past 4 years. Repeated surgical interventions on the pacemaker system were found to be the most common predisposing factors. Staphylococcus aureus and Staphylococcus epidermidis were the most common causative organisms. Two-dimensional echocardiography was important in the diagnosis of cases with atypical clinical picture and negative blood cultures. We concluded that: (1) any pacemaker patient with fever should be considered to have a pacemaker endocarditis; (2) all of these patients should be examined by two-dimenensional echocardiography; and (3) the total removal of the infected hardware seems to be the only way to achieve complete recovery.     

原花青素的抗氧化作用

目的:概述原花青素的结构特点、药理特性,探讨并分析原花青素的抗氧化作用及其在体育领域内的发展前景,旨在为此天然高效的抗氧化剂的开发利用提供一些理论的支持。方法:应用计算机检索Medline 1960-01/2006-08关于原花青素文章。检索词“proanthocyanidin”并限定文章的语种类为English。同时利用计算机检索中国期刊全文数据库1960-01/2006-08的相关文章,限定文章语言种类为中文,检索词“原花青素”。结果:原花青素是一种良好的氧游离基清除剂和脂质过氧化抑制剂。可有效清除超氧阴离子自由基和羟基自由基,也参与磷脂、花生四烯酸的新陈代谢和蛋白质磷酸化,保护脂质不发生过氧化损伤。原花青素为强有力的金属螯合剂,可螯合金属离子,在体内形成惰性化合物。有保护和稳定维生素C,有助于维生素C吸收的作用。结论:原花青素拥有强有力的抗氧化、清除自由基以及改善体循环的特殊功效,并以高效、低毒、高生物利用度而著称,原花青素的多种生物学功效在预防和治疗疾病中将发挥越来越大的作用。     

Cerebral Embolism Due to a Retained Pacemaker Lead: A Case Report

There are only a few reported cases of a pacemaker lead migrating inadvertently into the left atrium or ventricle. An unusual complication of unremoved, unwanted pacemaker lead is presented. The free tip of the lead caused cerebral embolism after perforating the interatrial septum.     

Detection of Hepatitis B Virus DNA Sequences in Liver in HBsAg Seronegative Patients with Liver Disease with and without Anti-HBc Antibodies

Excluding studies from Brechot and co-workers, little supporthas been found for a role of the hepatitis B virus in the pathogenesisof HBsAg seronegative patients with predominantly chronic liverdiseases, including primary liver cancer. In this study liverDNA from 59 predominantly British patients (four cases withpaired biopsies, 6–12 months apart) with different, mostlychronic, liver diseases was analysed by molecular hybridization.All were seronegative for HBsAg and serum hepatitis B virusDNA (dot blot hybridization) and their liver diseases were believedto be unrelated to hepatitis B virus infection. Hepatitis Bvirus DNA was detected in liver of 11 (18.6 per cent) patients;nine had episomal(3.2 Kb) DNA and eight had higher molecularweight bands suggesting integrated forms. Six patients werealso seronegative for anti-HBc. Patients of UK and non-UK originwere equally represented. Hepatitis B virus DNA was detectedin serum of six of nine patients tested using the polymerasechain reaction. The detection of hepatitis B virus DNA in liverand in serum by this assay in a significant proportion of patientswith chronic liver disease, hitherto unsuspected of being hepatitisB virus-related, suggests a possible role for this virus inlow- as well as high-prevalence countries.     

Proliferative arrest and rapid turnover of thymic epithelial cells expressing Aire

Expression of autoimmune regulator (Aire) by thymic medullary epithelial cells (MECs) is critical for central tolerance of self. To explore the mechanism by which such a rare cell population imposes tolerance on the large repertoire of differentiating thymocytes, we examined the proliferation and turnover of Aire(+) and Aire(-) MEC subsets through flow cytometric analysis of 5-bromo-2'deoxyuridine (BrdU) incorporation. The Aire(+) MEC subset was almost entirely postmitotic and derived from cycling Aire(-) precursors. Experiments using reaggregate thymic organ cultures revealed the presence of such precursors among Aire(-) MECs expressing low levels of major histocompatibility complex class II and CD80. The kinetics of BrdU decay showed the Aire(+) population to have a high turnover. Aire did not have a direct impact on the division of MECs in vitro or in vivo but, rather, induced their apoptosis. We argue that these properties strongly favor a "terminal differentiation" model for Aire function in MECs, placing strict temporal limits on the operation of any individual Aire(+) MEC in central tolerance induction. We further speculate that the speedy apoptosis of Aire-expressing MECs may be a mechanism to promote cross-presentation of the array of peripheral-tissue antigens they produce.     

Tetracycline-controllable selection of CD4(+) T cells: half-life and survival signals in the absence of major histocompatibility complex class II molecules

A system that allows the study, in a gentle fashion, of the role of MHC molecules in naive T cell survival is described. Major histocompatibility complex class II-deficient mice were engineered to express Ealpha chains only in thymic epithelial cells in a tetracycline (tet)-controllable manner. This resulted in tet-responsive display of cell surface E complexes, positive selection of CD4(+)8(-) thymocytes, and generation of a CD4(+) T cell compartment in a class II-barren periphery. Using this system, we have addressed two unresolved issues: the half-life of naive CD4(+) T cells in the absence of class II molecules (3-4 wk) and the early signaling events associated with class II molecule engagement by naive CD4(+) T cells (partial CD3 zeta chain phosphorylation and ZAP-70 association).     

经冠状动脉自体骨髓单个核细胞移植对扩张型心肌病兔心肌组织病理学的影响

目的:骨髓干细胞在扩张型心肌病动物模型中具有向心肌样细胞和血管内皮细胞分化的潜能。评价经冠脉自体骨髓单个核细胞移植治疗对扩张型心肌病兔心肌组织病理学影响及心功能的变化。方法:实验于2006-09/2007-03在复旦大学附属华山医院心血管研究室完成。①实验材料:3月龄雄性新西兰兔25只,随机数字表法分为正常组5只、模型组10只、冠脉移植组10只。②实验方法:冠脉移植组、模型组兔经耳缘静脉注射盐酸阿霉素建立扩张型心肌病模型。冠脉移植组10只兔麻醉后以髂骨为穿刺点,共采集15mL混有肝素生理盐水的骨髓液,密度梯度离心得到自体骨髓单个核细胞悬液2mL,其中5只兔的骨髓单个核细胞悬液行DAPI标记,经塑性的4F造影导管,模拟临床冠脉内输注细胞悬液。③实验评估:术后4周通过检测血流动力学指标评价心功能的改变;苏木精-伊红、天狼猩红染色观察心肌组织形态学特点,透射电镜观察心肌组织超微结构的改变;TnT间接免疫荧光检测心肌组织DAPI标记情况,以评价骨髓单个核细胞的分化和转归。结果:①血流动力学指标的测定:与基础值比较,细胞移植4周后模型组兔血流动力学指标无明显改变(P>0.05),而冠脉移植组心功能显著改善(P<0.05)。②心肌组织形态学观察:扩张型心肌病兔心肌纤维排列紊乱,坏死区大量淋巴细胞浸润,细胞间隙增宽,心肌间质面积增大。③心肌组织超微结构的变化:造模结束后,模型组心肌细胞线粒体肿胀,肌丝断裂,心肌细胞核呈锯齿状,心肌间质中淋巴细胞浸润,胶原纤维增多。细胞移植4周后,冠脉移植组出现线粒体堆积现象,亦存在巨噬细胞浸润和胶原纤维轻度增生,未发现心肌组织中存在植入的特殊类型细胞。④心肌组织TnT间接免疫荧光检测:DAPI标记的骨髓单个核细胞在心肌组织中富集,血管腔内不存在。结论:①经冠脉自体骨髓单个核细胞移植治疗阿霉素扩张型心肌病兔,利于植入细胞在心肌组织中富集,改善心功能。②透射电镜尚无法证实心肌组织中存在外来的移植细胞。     

Lack of Foxp3 function and expression in the thymic epithelium

Foxp3 is essential for the commitment of differentiating thymocytes to the regulatory CD4(+) T (T reg) cell lineage. In humans and mice with a genetic Foxp3 deficiency, absence of this critical T reg cell population was suggested to be responsible for the severe autoimmune lesions. Recently, it has been proposed that in addition to T reg cells, Foxp3 is also expressed in thymic epithelial cells where it is involved in regulation of early thymocyte differentiation and is required to prevent autoimmunity. Here, we used genetic tools to demonstrate that the thymic epithelium does not express Foxp3. Furthermore, we formally showed that genetic abatement of Foxp3 in the hematopoietic compartment, i.e. in T cells, is both necessary and sufficient to induce the autoimmune lesions associated with Foxp3 loss. In contrast, deletion of a conditional Foxp3 allele in thymic epithelial cells did not result in detectable changes in thymocyte differentiation or pathology. Therefore, in mice the only known role for Foxp3 remains promotion of T reg cell differentiation within the T cell lineage, whereas there is no role for Foxp3 in thymic epithelial cells.