Novel immunofluorescence assay using recombinant nucleocapsid-spike fusion protein as antigen to detect antibodies against severe acute respiratory syndrome coronavirus

Severe acute respiratory syndrome (SARS) is caused by a novel and highly infectious virus named SARS coronavirus (SARS-CoV). Among the serological tests currently available for the detection of SARS-CoV, a whole-virus-based immunofluorescence assay (IFA) was considered one of the most sensitive assays and served as a "gold standard" during the SARS epidemic in Singapore in 2003. However, the need to manipulate live SARS-CoV in the traditional IFA limits its wide application due to the requirement for a biosafety level 3 laboratory and the risk of laboratory infection. Previously, we have identified two immunodominant epitopes, named N195 and Sc, in the two major structural proteins, the N and S proteins, of SARS-CoV (Q. He, K. H. Chong, H. H. Chng, B. Leung, A. E. Ling, T. Wei, S. W. Chan, E. E. Ooi, and J. Kwang, Clin. Diagn. Lab. Immunol., 11:417-422, 2004; L. Lu, I. Manopo, B. P. Leung, H. H. Chng, A. E. Ling, L. L. Chee, E. E. Ooi, S. W. Chan, and J. Kwang, J. Clin. Microbiol. 42:1570-1576, 2004). In the present study, the N195-Sc fusion protein was highly expressed in insect (Sf9) cells infected with a recombinant baculovirus bearing the hybrid gene under the control of a polyhedrin promoter. An IFA based on Sf9 cells producing the fusion protein was standardized with 23 serum samples from patients with SARS, 20 serum samples from patients with autoimmune diseases, and 43 serum samples from healthy blood donors. The detection rates were comparable to those obtained with a commercial SARS-CoV IFA kit (EUROIMMUN, Gross Groenau, Germany) and a conventional IFA performed at the Singapore General Hospital. Our data showed that the newly developed IFA could detect SARS-CoV in 22 of the 23 SARS-CoV-positive serum samples and gave no false-positive results when the sera from patients with autoimmune diseases and healthy individuals were tested. The detection rate was identical to those of the two whole-virus-based IFAs. Thus, the novel N-S fusion antigen-based IFA could be an attractive alternative to present whole-virus-based IFAs for the diagnosis of SARS-CoV infection.     

Significant HLA-A02 allelic variation revealed in chinese and caucasian populations

HLA-A2 subtypes (A^*0201 - ^*0212) were determined by oligotyping in HLA-A2 positive samples from four populations (Han Chinese, Dai Chinese, Caucasoids from Germany and Turkish individuals from Kayseri)(see table).

Two different findings can be concluded from this study: 1) Significant HLA-A^*02 allelic variations found in four populations. A^*0207 is the predominant A^*02 allele in the Dai population and absent in the German Caucasian and the Turkish population. In contrast, A^*0201 is the most prevalent allele in the Caucasian, Turkish and Han Chinese group. We also found a high proportion of A^*0206 and A^*0207 in Han Chinese. 2) A strong association has been found between A^*0207 and HLA-B46 and DR9 in the Dai minority population. This haplotype is also found in Han Chinese. Three DNA samples from Turkish and one from the Dai population are presently being sequenced because the reaction pattern was out of the expected (Supported by SFB 217)     

基于曲面拟合法的肝脏超声成像仿真数学建模

目的研究虚拟人体器官三维影像轮廓的计算机仿真建模。方法以肝脏虚拟影像轮廓的三维数学建模为例，以人体肝脏的声阻二维分布为依据，应用曲面拟合的数值方法进行研究。结果计算机仿真证明了该建模方法的正确性和有效性。结论人体器官的虚拟超声成像是医学超声仿真系统的一项关键技术，在医务人员上岗培训中具有重要的意义。该文所提出的数学建模方法对于虚拟器官三维影像轮廓的仿真切实可行。     

Influx of leukocytes and platelets in an evolving brain infarct (Wistar rat).

The results of several experimental studies of focal ischemia and anecdotal observations suggest that leukocytes may contribute to the injury initiated by an arterial occlusion. The timing and the nature of leukocyte responses in evolving brain infarcts (either human or experimental) are incompletely characterized. This is a study of experimental brain lesions in 96 Wistar rats that underwent occlusion of a large intracranial artery for variable intervals ranging between 30 minutes and 7 days. The experimental model, based on the occlusion of a middle cerebral artery ostium via the insertion of a nylon monofilament through the external carotid artery, does not require opening the skull; therefore, the inflammatory response is not influenced by the effects of craniotomy and changes in intracranial pressure are only those induced by the ischemic lesion. All 96 animals having the same type of arterial occlusion developed an ischemic brain lesion (limited to the territory of the corresponding artery) that evolved into an area of extensive neuronal necrosis over a period of 6 to 12 hours followed by pan-necrosis (infarct) approximately 60 hours later. In this study, leukocytes (in particular polymorphonuclear cells) were detected in the microvessels (capillaries and venules) of the ischemic hemisphere as early as 30 minutes after the arterial occlusion. Numbers of intravascular neutrophils peaked at 12 hours, whereas intraparenchymal granulocytes were most numerous at 24 hours; a few granulocytes were visible in the brain infarct as late as day 7. Circulating monocytes were first detected within the capillaries/venules of the ischemic area after 4 to 6 hours. Platelet aggregates were more abundant in the arterial than the venous side of the circulation, and luminal obstruction of arteries by platelet aggregates became noticeable only 48 hours after the arterial occlusion. Fibrin thrombi were conspicuous for their absence. These observations provide the background for studies that will attempt to unravel the relationship between the biological responses of leukocytes and neuronal necrosis secondary to focal ischemia.     

The effect of a levonorgestrel-releasing intrauterine device on human endometrial oestrogen and progesterone receptors after one year of use

Thirty-four women bearing a levonorgestrel-releasing intrauterine device, 20 micrograms/day (LNG-IUD-20), for 12-15 months were recruited. Endometrial biopsies were collected during the late proliferative phase of the cycle (on cycle days 10-12) before (control) and after the use of the IUD for 12 months, and assayed for oestrogen receptors (ER) and progesterone receptors (PR). An immunohistochemical technique with the peroxidase-antiperoxidase detection system (PAP method) was employed. D75 and JZB39 were the primary antibodies for ER and PR respectively. The immunostaining semiquantitative analysis was performed with a computerized microscope image processor, and expressed as 'grey value'. Both endometrial ER and PR populations were significantly lower after insertion of the IUD (P < 0.01) than in control biopsies. The intensity of nuclear staining and the percentage of positively stained cells for ER and PR in women with LNG-IUD were each about 50% of those in control biopsies. The results suggested that LNG released locally from the IUD has a depressive action on the ER and PR, which may contribute to the contraceptive effectiveness of this type of IUD and also to the possible causes of LNG-IUD-induced irregular bleeding and amenorrhoea.     

IL-1α及LPS 刺激Caco-2细胞防御素表达的差异性

目的 比较细胞因子及LPS组对Caco-2细胞防御素表达的差别。方法用LPS和rhIL-1α刺激Caco-2细胞，采用半定量RT-PCR技术观察防御素HD-5、HD-6、hBD-1和hBD-2 mRNA的表达差异。结果经IL-1α刺激后，hBD-1的表达量有所增加，同时hBD-2、HD-5和HD-6也能表达；但LPS刺激后，hBD-1的表达量增加不明显，HD-5、HD-6和hBD-2仍未表达。结论Caco-2细胞对LPS的刺激产生“哑”反应，推测肠上皮对LPS存在一定的适应性，这对维持一定的正常菌群有益。     

新生儿缺氧、缺血性脑病血中6-keto-PGF1α,NSE水平变化的临床研究

目的:探讨HIE患者血中6-keto-PGF1α、NSE水平变化及临床意义.方法:用RIA检测89例HIE患者和32例正常新生儿血中6-keto-PGF1α、NSE水平变化.结果:HIE轻、中、重度组6-keto-PGF1α水平与正常对照组比较,均存在显著性差异(p＜0.01),HIE患者轻度组NSE水平与对照组比较无显著性差异(p＞0.05),中、重度组NSE水平与对照组比较存在显著性差异(p＜0.01),6-keto-PGF1α、NSE二组血中浓度上升与HIE程度呈正相关.结论:HIE患者中6-keto-PGF1α、NSE水平检测,对判断HIE的脑损伤程度、治疗、预后观察,具有重要临床意义和应用价值.     

表面磁性膜医用316L不锈钢支架的生物相容性

目的 对表面磁性膜血管内支架进行生物相容性研究,为该支架的临床应用提供实验依据.方法 通过溶血实验、动态凝血时间实验、急性全身毒性实验、皮内刺激实验、细胞毒性实验、热源实验、过敏实验、体内植入实验综合评价表面磁性膜血管内支架的生物相容性.结果 表面磁性膜血管内支架无溶血反应及凝血功能的改变,无急性全身毒性反应,无热源反应,支架材料中不存在致敏性物质;支架材料动物体内植入在初期有轻度的炎性反应,12周后炎性反应基本消失,未见炎性细胞浸润积聚现象.结论 表面磁性膜血管内支架具有良好的生物相容性,其应用于临床具有可行性和安全性.     

国内外产科质量指标体系现状和启示

通过文献回顾,对世界卫生组织产科质量指标体系、英国产科质量指标体系、美国产科质量指标体系、欧洲围产期保健计划、丹麦产科质量指标体系及我国的产科质量指标体系现状进行总结。认为我国产科质量指标体系缺乏最佳的指标变化趋势及期望达到的目标值,缺少基于产科质量指标进行质量改进的研究和证据,尚无基于产科质量指标体系的信息化质控平台。对此,建议探索产科质量控制指标的适宜标准值,建立质量指标和医疗质量评价的关联性,拓展指标体系内涵,加快信息化建设。     

NLRP3炎症小体与糖尿病心肌病的关系及中医药调控研究进展

糖尿病心肌病（DCM）是糖尿病的并发症之一,是指发生在糖尿病中,其发病机制区别于其他心血管疾病如冠心病、心脏瓣膜病、亦或先天性心脏病的一种特发类心肌病,亦是多年以来糖尿病患者的主要致死病因之一。研究表明,DCM的发病机制与胰岛素抵抗、多种炎症反应激活、氧化应激增加、冠状动脉微循环受阻、晚期糖基化终产物（AGEs）积累等过程有密切联系。而在多种炎症反应中,NOD样受体蛋白3（NLRP3）炎症小体激活可通过炎症的级联反应诱导分泌出大量促炎细胞因子,继而介导细胞焦亡过程,促进心肌损伤。目前基于NLRP3炎症小体在DCM损伤防治重要作用功能,国内外开展了大量中医药实验研究,证明了黄芪多糖、人参皂苷Rb₁等中药提取物或单味中药如云芝、冬虫夏草亦或抵挡汤、加味桃核承气汤等组方制剂及针刺、中医运动疗法等可通过调控NLRP3炎症小体的相关通路从而抑制其组装或激活,降低炎症反应,进而抑制DCM中心肌的重构,改善DCM的心脏功能。该文就NLRP3炎症小体与DCM的关系及中医药在此领域中发挥抗炎效应的研究进展进行综述,旨在为DCM开发治疗手段提供新的思路。