巨蜥的循环系统及其对环境的适应

巨蜥的心室可分为前后两部分三个相的亚腔，即动脉腔，静脉腔和肌腔，由于心房都开口于管状动脉腔右端，心室舒张时，两心房血液同时流出势秘造成混合，故右心房内血液首先以量子释放方式经动脉腔流入最腹部的肺腔中，接着左心房内血液因压力升高冲开房室孔进入动脉腔，先后进入动脉腔的静，动脉血界面处有极少量混合血；心室收缩时，水平隔与心室前壁肌嵴嵌合而把心室重新分动成脉粒－静脉腔和肺腔两个独立腔，由于体动脉压较高，血     

70例内镜超声检查结果分析及体会

目的 :主要分析内镜超声检查 (EU S)结果及介绍检查体会。方法 :对 70例已行常规胃镜、B超、CT等检查后有EUS检查适应症的患者行 EU S检查。结果 :2 9例食管胃粘膜及粘膜下隆起病中检查出粘膜增厚 3例 ,囊肿 2例 ,平滑肌瘤 9例 ,胸主动脉 2例 ,脾 7例 ;胆胰疾病 2 9例中检查出胰腺癌 5例 ,胰腺囊肿 4例 ,胰腺炎 4例 ,胆总管结石 5例 ,胆总管外肿瘤和肝门处肿瘤各 1例 ,另外还有胸腺瘤放疗后效果及其顽固性呃 口逆原因 ,食管胃癌的侵袭深度及淋巴结转移。结论 :EU S所检查的以上疾病是其他检查所不能替代的 ,并且通过 70例的检查得到了掌握适应症、操作技巧及检查过程中注意事项的多种体会     

Interleukin-12, a key cytokine in Th1-mediated autoimmune diseases

Interleukin 12 (IL-12) is a heterodimeric cytokine produced primarily by antigen-presenting cells (APCs) which plays a key role in promoting type 1 T helper cell (Th1) responses. The powerful activity of IL-12 requires tight control, which is exerted at various levels. Primary control is exerted on IL-12 production by APCs, a major factor driving the response towards the Th1 or Th2 phenotype. Another level of control regulates expression of the IL-12 receptor (IL-12R), which is composed of two subunits, β1 and β2. The IL-12R β2 subunit has signal-transducing capacity and modulation of its expression is central to the regulation of IL-12 responsiveness. Endogenous IL-12 plays an important role in host defense against infection by a variety of intracellular pathogens. Its Th1-promoting activity, however, also favors Th1-mediated immunopathology and, in particular, the induction of Th1-mediated autoimmune diseases. Received 15 January 1999; received after revision 11 March 1999; accepted 16 March 1999     

PCR扩增检测献血者中TT病毒DNA及部分TTV基因序列分析

目的：了解江苏地区献血者中新型肝炎相关病毒－－TT病毒的感染状况，探讨TTV感染与ALT异常的相关性，方法：设计通用引物，采用半套式聚合酶链反应（hemi-nested PCR)方法检测195份献血者血清标本，结果，在血清丙氨酸转氨酶（ALT）异常，HBsAg及抗HCV阴性的99份献血者血清标本中，检出TTV DNA阳性标本36份，TTV DNA的阳性检出率为36．3％，而在96份正常献血者血清标本中，检出TTV DNA阳性标本16份，TTV DNA阳性检出率为16．6％，明显低于ALT常献血者人群，对2株阳性株序列分析结果显示，一株与TX011（G1b日本代表株）的同源性为98．6％，属于G1b亚型，另一株虽可归属于G1，但与G1a ，Blb差异较大，可能为G1的新亚型，结论：江苏地区献血者人群中存在TTV感染，国内首次报告检出TTV G1b亚型及新的亚型，献血者ALT异常与TTV感染密切相关，输血可能成为传播TTV感染的途径之一。     

古典跤运动员亚高原训练血压与晨脉变化规律的研究

研究了陕西省古典跤运动员在太白山高原训练时的身体机能变化规律 .对参加第四届全国城市运动会的集训运动员跟队追踪测试约两个月 ,得出了其血压与晨脉在高原训练期间的变化参数     

微量元素锌与人类疾病

锌是人体内重要的微量元素之一，在人体正常的生理生化活动中起重要作用．缺锌可导致机体免疫功能低下、生育功能异常、某些肿瘤的诱发、学习记忆障碍、糖尿病的产生以及小儿智力降低、生长发育缓慢等多种疾病．     

云南省高血压患病率影响因素的类回归分析

分析影响高血压的患病率因素，对高血压的防治和研究都有重要意义．用类回归的方法，对所获得的大量样本数据进行分析，找出了高血压与年龄、城乡、饮酒、体重指数等多种因素之间的相关关系     

略论藏族神话的类型与表现形式

文章从藏族神话资料入手,依照文化发生学角度分类阐释分析了藏族的创世神话、人类起源神话、生产劳动神话和造神神话的各自特点及其演变过程。     

基于线性系统理论的热网平衡方法——用“周期供热量”调节热网平衡

依据线性系统理论分析供热系统运行特点,建立了用“周期供热量”管理供热系统热力平衡的理论体系。通过应用说明了这种新理论体系具有好的可操作性。     

Tracking prions: the neurografting approach

The physical nature of the agent that causes transmissible spongiform encephalopathies (the 'prion'), is the subject of passionate controversy. Investigation of it has benefited tremendously from the use of transgenic and knockout technologies. However, prion diseases present several other enigmas, including the mechanism of brain damage and how the affinity of the agent for the central nervous system is controlled. Here we show that such questions can be effectively addressed in transgenic and knockout systems, and that pathogenesis may be clarified even before we can be certain about the nature of the infectious agent. Availability of mice overexpressing the Prnp gene (which encodes the normal prion protein) and Prnp knockout mice allows for selective reconstitution experiments aimed at expressing PrP in specific portions of the brain or in selected populations of hemato- and lymphopoietic origin. We summarize how such studies can offer insights into how prions administered to peripheral sites can gain access to central nervous tissue, and into the molecular requirements for spongiform brain damage.