隐花色素-1基因与精神分裂症核心家系的传递不平衡分析

目的探讨精神分裂症与隐花色素-1（Cryl）基因多态性的关联关系。方法应用聚合酶链反应和限制性片段长度多态性技术对100个精神分裂症核心家系的Cryl基因上的多态性位点rs2300448、rs1921135和rs1056560进行多态性检测；用Genehunter2．1软件包进行传递不平衡分析（TDT），并构建可能的单体型。结果（1）rs2300448多态性位点等位基因G和等位基因A传递给患病子女的频率差异有统计学意义，等位基因G优先传递给患病子女（X^2=4．92，P=0．027），但P值经Bonferroni校正后，差异无统计学意义（Pc=0．054）；rs1056560和rs1921135多态性位点未发现传递不平衡现象（X^2=0．15，P=0．698；X^2=0．56，P=0．456）。（2）单体型rs2300448-rs1056560G—A（X^2=6．76，P=0．009）、rs1921135-rs2300448-rs1056560T—G—C（X^2=4．50，P=0．034）和C—G—A（X^2=6．37，P=0．012）存在传递不平衡现象，但P值经Bonferroni校正后，T—G—C和C—G—A差异均无统计学意义（Pc〉0．05），只有单体型rs2300448-rs1056560G—A差异有统计学意义（Pc=0．036）。结论Cry1基因可能与精神分裂症相关联。     

人埃立克体的传播途径及其遗传基础

本文从媒介、宿主、传播途径及其遗传学基础对埃立克体传播循环中获得的最新进展进行综述性回顾,为人埃立克体病的预防提供技术支持和基础资料。     

丹参改善骨骼肌缺血再灌注损伤的超微结构观察

目的:通过透射电镜观察骨骼肌缺血再灌注损伤过程的病理生理变化探讨丹参的干预作用及机制。方法:采用90只清洁级雄性SD大鼠,6只作为健康对照组,84只行左侧提睾肌主滋养动脉夹闭造模,在缺血2.5 h时,丹参组腹腔注射丹参(42只),对照组注射等剂量的生理盐水(42只),两组分别设缺血再灌注10、20、30、40、50、60、90 min观测点(每个观测点6只)。观测结束后,迅速切取提睾肌,放入电镜固定液。电镜下进行组织形态学观察。结果:健康对照组正常情况下,组成肌原纤维的粗、细2种肌丝沿其长轴排列,每条肌原纤维上均可见明暗相间的带,肌浆内见有较多糖原颗粒及少量内质网、线粒体等细胞器,肌浆网纵向分布于肌原纤维周围,线粒体膜及嵴清晰可见,基质着色深,无肿胀、空泡形成等改变,在肌丝之间分布有较多糖原颗粒;骨骼肌缺血再灌注后10、20、30、40、50、60、90 min的2组各观测点,其病理变化较相似,肌丝模糊、凌乱,部分溶解、消失,甚至完全消失,肌浆网不同程度扩张,线粒体变大变圆,基质变淡,嵴变短变少甚至消失,部分线粒体极度肿胀,呈空泡状。丹参组,其病理变化大体相似,肌纤维均有不同程度恢复。结论:骨骼肌缺血再灌注损伤导致线粒体极度肿胀,肌纤维紊乱。丹参能有效地消除线粒体的水肿,恢复肌纤维,减轻骨骼肌缺血再灌注损伤。     

流行性出血热人群传播速度的定量研究

选取家鼠型ＥＨＦ中发病区人群血清ＥＨＦ抗体阳性率资料，试用可逆催化模型对ＥＨＦ人群传播速度进行定量研究。结果表明：所建立的可逆催化模型其理论值与实际值理论拟合较好，用χ＾２做配合适度检验，Ｐ〉０．０５。证实可逆催化模型可用来作ＥＨＦ人群中传播速度的定量研究。还发现在家鼠型ＥＨＦ疫区每１０００人中约有８０人因有效接触而获得感染，同时又有４０人血清ＥＨＦ抗体转阴。     

丙型肝炎传播途径的病例对照研究

本文按１１病例对照设计研究了丙型肝炎的传播途径。结果显示：无论单因素还是多因素条件Ｌｏｇｉｓｔｉｃ回归分析，输血及血制品都是丙型肝炎传播的一条重要途径。多因素条件Ｌｏｇｉｓ－ｔｉｃ回归分析的ＯＲ＝４．４８０，Ｐ＝０．００１。另外，肝炎家族史和外科手术史也可能与丙型肝炎的感染有关。本研究未发现注射、有创性检查以及外出饮食习惯与ＨＣＶ感染的关系     

输送链的结构与齿形探讨(三)——修正齿形链传动特性及完善齿形修正设计

本文讨论用“包络一轨迹”法设计的修正齿形链的传动特性,并提出了完善齿形修正设计的方法,基本上实现消除链传动申的“多边形效应”。     

Measured attenuation correction methods

Accurate attenuation correction is a prerequisite for the determination of exact local radioactivity concentrations in positron emission tomography. Attenuation correction factors range from 4–5 in brain studies to 50–100 in whole body measurements. This report gives an overview of the different methods of determining the attenuation correction factors by transmission measurements using an external positron emitting source. The long-lived generator nuclide⁶⁸Ge/⁶⁸Ga is commonly used for this purpose. The additional patient dose from the transmission source is usually a small fraction of the dose due to the subsequent emission measurement. Ring-shaped transmission sources as well as rotating point or line sources are employed in modern positron tomographs. By masking a rotating line or point source, random and scattered events in the transmission scans can be effectively suppressed. The problems of measured attenuation correction are discussed: transmission/emission mismatch, random and scattered event contamination, counting statistics, transmission/emission scatter compensation, transmission scan after administration of activity to the patient. By using a double masking technique simultaneous emission and transmission scans become feasible.This article was presented at the 1st EEC workshop on accuracy determination in PET, January 19–20th. 1989 Pisa, Italy (COMAC-BME Concerted Project Characterization and Standardization of PET Instrumentation)     

Time-dependent morphological alterations of cold-stored small bowel in Euro-Collins and Ringer's lactate solutions

Small bowel is one of the organs that can in principle be transplanted. Optimum preservation of the organ is essential for the success of transplantation. The aim of the present study is the investigation of time-related morphological changes of rat small bowel during preservation in hypothermic Euro-Collins (EC) and Ringer's lactate (RL) solution using light microscopy and transmission electron microscopy to evaluate the integrity of intercellular complexes of mucosal epithelium, one of the tissues of the intestine that is most susceptible to ischemia. Small bowels were perfused with either EC, RL solution or physiological saline solution and were placed in the different preservation solutions at 4 degrees C for 0, 3, 6 and 12 h. The results of our study suggest that both preservation solutions are suitable for short-term preservation of the small bowel although RL solution is more effective than EC solution. However, we conclude that further improvement of preservation solutions and/or techniques are needed to perform long-term preservation.     

Occlusion and subsequent re-canalization in early duodenal development of human embryos: integrated organogenesis and histogenesis through a possible epithelial-mesenchymal interaction

Histogenesis of the duodenum, especially changes in the epithelium in relation to temporal occlusion and re-canalization of the lumen, was investigated by light microscopy together with morphometric analysis, as well as by scanning and transmission electron microscopy of 133 externally normal human embryos ranging from Carnegie stage 12 to 23. A series of morphogenetic events passed the duodenum in a cranio-caudal (proximo-distal) wave like fashion during the period examined. They included: (1) a decrease in the caliber and area of the lumen, (2) ’occlusion’ of the lumen, (3) vacuole formation, (4) ’re-canalization’ and villi formation. The only exemption to this rule was that, in the upper part of the duodenum, the lumen was not obliterated in the embryos examined. Morphometric analyses revealed that both the area of the epithelium and the number of epithelial cells decreased during the ’occlusion’ phase. This result suggests that, unlike the classical view, epithelial cell proliferation does not play an important role in occluding the lumen, but the predominant morphogenetic event during this phase is convergence of the epithelial cells to elongate the duodenum. Apoptosis, contrary to some classical views, decreased during the ’re-canalization’ phase, and it appeared to be involved in the formation of the small lumens in the epithelial ’plug’ and in villi formation, but not in enlarging the secondary lumens. The secondary small lumens in the occluded lumen were frequently formed near the border between the central ’plug’ and peripheral basal cells on the basement membrane. This and other findings of concentric differentiation in both the epithelial and mesenchymal layers suggested a possible control mechanism by the epithelium-mesenchymal interaction on human duodenal morphogenesis and histogenesis. The present electron microscopic observations also provided details on the mechanisms involved in the enlargement of the secondary lumen and differentiation of villi. The implications of these findings to duodenal anomalies are also discussed. Accepted: 12 November 2001