两种后牙根管预备方法的临床效果比较

目的 :评估 2种后牙根管预备方法的临床效果。方法 :采用机用镍钛扩大锉 (ProFile)和手用不锈钢扩大锉 (K file)扩大后牙根管 ,并对 2组病例术后疼痛以及充填情况加以比较。结果 :发现机用镍钛扩大锉扩大后牙根管 ,具有去除根管感染物质彻底 ,根管形态保持良好 ,速度快 ,术后疼痛率较低的优点 ,但易出现断针。而手用不锈钢扩大锉扩大后牙根管速度较慢 ,术后疼痛率略高 ,但不易出现断针 ,操作上容易掌握。结论 :2种后牙根管方法都有优缺点 ,可结合起来使用。     

白细胞介素—2新的功能位点及其中枢镇痛作用

白细胞介素－２（ＩＬ－２）不仅是重要的免疫调节因子，而且还具有重要的中枢调节作用。本实验以钾离子透入引起大鼠甩尾反应为指标，发现侧脑室注射ＩＬ—２能显著提高动物痛阈，并能被纳洛酮所阻断，表示ＩＬ－２的中枢镇痛作用可能与阿片受体有关。利用基因定位突变技术获得的无免疫活性ＩＬ－２实查体仍具有中枢镇痛作用，表明ＩＬ—２分子上发挥镇痛和免疫调节作用的功能位点是相互独立的。纳洛酮能够阻断ＩＬ—２的中枢镇痛作用，而不能影响ＩＬ—２增殖ＣＴＬＬ－２细胞的作用，提示ＩＬ－２发挥镇痛和免疫调节作用可能通过不同的受体途径。ＩＬ－２分子中第４５位Ｔｙｒ残基突变为Ｖａｌ后，虽仍保留了免疫活性，但丧失了镇痛功能，表示４５位Ｔｙｒ残基是ＩＬ—２发挥中枢镇痛功能的关键残基之一。我们推测ＩＬ—２的镇痛功能位点可能在ＩＬ—２分子中第４５位Ｔｙｒ残基附近区域。     

帕金森氏病和肌营养不良症（Erb型）中线粒体DNA的部分缺失

用ＰＣＲ技术对１２例神经肌肉性疾病患者的１６个标本进行了线粒体ＤＮＡ缺失情况的研究。发现２例帕金森氏病患者的肌肉组织以及其中１例的外周血和另１例肌营养不良（Ｅｒｂ型）患者的肌肉组织中线粒体ＤＮＡ至少有５２６ｂｐ的缺失。还对线粒体ＤＮＡ的部分缺失与疾病发生的关系进行了讨论。     

理气类中药对大鼠离体胃平滑肌条的作用

目的：观察理气类中药对大鼠离体胃平滑肌条运动的影响。方法：将肌条放置在灌流肌槽中，用生理记录仪记录肌条的收缩活动。结果：陈皮、枳实对胃各部位平滑肌条均为抑制效应，香附、薤白、木香、柿蒂、乌药对胃底肌条为兴奋效应，但对其他部位肌条则表现为兴奋或抑制不同的效应，沉香仅降低胃窦环行肌收缩波平均振幅，对其他肌条无影响。结论：理气类中药对大鼠离体胃平滑肌条既有兴奋作用，也有抑制作用。     

局限缺血－再灌注心肌细胞内钙超负荷发生机制的探讨

本文通过犬急性心肌缺血－再灌注模型探讨缺血－再灌注心肌Ｃａ２＋超负荷的发生机制。当心肌持续缺血１５０ｍｉｎ，心肌细胞内Ｃａ２＋、Ｎａ＋增加、Ｋ＋降低；心肌细胞膜Ｎａ＋－Ｋ＋－ＡＴＰａｓｅ、Ｃａ２＋－ＡＴＰａｓｅ活性降低，心肌组织丙二醛（ＭＤＡ）含量增加．而心肌缺血９０ｍｉｎ后，再灌注６０ｍｉｎ，与之比较细胞内Ｃａ２＋明显增加，伴Ｎａ＋升高、Ｋ＋降低，心肌细胞膜Ｎａ＋－Ｋ＋－ＡＴＰａｓｅ、Ｃａ２＋－ＡＴＰａｓｅ活性降低，ＭＤＡ含量增加，说明缺血－再灌注过程中Ｎａ＋升高、Ｎａ＋－Ｃａ２＋交换增加，Ｃａ２＋－ＡＴＰａｓｅ活性降低是细胞内Ｃａ２＋超负荷发生的重要原因。     

纤维组织粘合剂的实验研究

本文应用“冷沉淀”法制备纤维组织粘合剂。对纤维组织粘合剂中主要成份和含量进行了测定,并测定了主要理化性质,建立了动物实验模型,观察了实验兔对纤维粘合剂的反应。     

Immunochemical and biochemical characterization of purified canine interferon-gamma. Production of a monoclonal antibody, affinity purification, and its effect on mixed lymphocyte culture and mixed lymphocyte kidney culture reactions.

We have advanced the hypothesis that the primary autolymphoproliferative response of dog T cells in mixed lymphocyte kidney cultures (MLKC) results from their recognition of tissue-specific (kidney-associated) antigen(s) presented in conjunction with class II MHC antigens. Lymphocyte culture-derived supernatants had been found previously to upregulate class II antigen expression on kidney cells and enhance T cell activation. In the present study we have isolated and characterized dog IFN-gamma, a class II-inducing substance that is secreted in the culture supernatant of activated T lymphocytes. Dog IFN-gamma was induced with A-23187 and PMA and purified stepwise using controlled-pore glass, Mono Q anion exchange chromatography, and Superose 6-gel filtration on FPLC. The purification resulted in two molecules of 42 Kd and 31 Kd molecular weights. An IgG1 monoclonal antibody was engendered to these molecules. With this mAb reagent, in immunochemical experiments, we have developed a sensitive ELISA and a method for purifying dog IFN-gamma by affinity chromatography. Species specificity studies indicated that purified dog IFN-gamma reacted with a polyclonal rabbit antihuman IFN-gamma, but not with a mAb to human IFN-gamma. However, the antidog IFN-gamma mAb that was generated also reacted with recombinant human IFN-gamma. In in vitro biological studies, the purified IFN-gamma (two mol. wt. species) upregulated the expression of canine class II MHC molecules on dog tubular epithelial cells and the dog kidney epithelial cell line (MDCK). The antidog IFN-gamma mAb blocked T cell proliferative response to kidney cell and, by inference, the interaction between endogenously released IFN-gamma in vitro with its cell surface receptor, thus inhibiting the induced upregulation of class II. Interestingly, although antidog IFN-gamma markedly blocked the MLKC (10 micrograms mAb/well), there was no effect on the allogeneic MLC. This observation indicates that the cytokine IFN-gamma may be a uniquely key substance amplifying the immune response of T cells to tissue-associated antigens on surrogate antigen-presenting cells that require induced upregulation of class II MHC antigen expression (MLKC), in contrast to reactions in which these antigens are already constitutively expressed on the antigen-presenting cells (mixed lymphocyte culture).     

泌尿系感染者病原菌及耐药性分析

目的：了解近年来泌尿系细菌感染致病菌及耐药性，为合理应用抗生素，提供临床根据。方法：对泌尿系感染患者298株病原菌进行药物敏感试验。结果：大肠埃希菌仍是引发泌尿系感染的主要病原菌，占53％，其次是葡萄球菌属，占19．40％，肠杆菌属占10．06％，肠球菌属占4．70％等，各类菌属耐药情况。结论：临床医师必须关注本地病原菌分布及耐药情况，合理应用抗生素，减少耐药性播散。     

Application of a 3D volume 19FMR imaging protocol for mapping oxygen tension (pO2) in perfluorocarbons at low field

A limited flip angle gradient-echo 3D volume acquisition imaging protocol for mapping partial pressure of oxygen (pO₂) in perfluorocarbon compounds (PFCs) at low field (0.14 T) is presented. The pO₂ measurement method is based on the paramagnetic effect of dissolved molecular oxygen (O₂) which reduces the PFC ¹⁹F T_1? Specific objectives related to imaging of PFCs through use of the protocol include improved image signal-to-noise characteristics and elimination of ¹⁹F chemical shift artifacts. A parametric Wiener deconvolution filtering algorithm is used for suppression of ¹⁹F chemical shift artifacts. Application of the protocol is illustrated in a series of calculated pO₂ maps of a gas equilibrated, multi-chamber phantom containing perfluorotributylamine (FC-43). The utility of the protocol is demonstrated in vivo through images of a commercially available perfluorocarbon based blood substitute emulsion containing FC-43 sequestered in the liver and spleen of a rat.