Molecular mechanisms of gamete recognition and fusion at fertilization

Advances in many areas of reproductive technology have been rapid and, in many respects, have outstripped our knowledge of the fundamental processes of human and animal sperm-egg interactions at fertilization. This is particularly true of human fertilization, where the availability of eggs for research purposes is severely restricted. As a consequence of this, most of the significant advances in our understanding of mammalian fertilization have resulted from studies on animals, particularly the mouse. This review summarizes our current knowledge of the molecular aspects of mammalian fertilization from the point of view of the fertilizing spermatozoon. Particular reference is made to those advances in our knowledge of human fertilization mechanisms. Further understanding of the molecular basis of human fertilization is of paramount importance for the development of new methods of contraception and also for the rational diagnosis and treatment of certain forms of infertility.      

吲哚美辛对β淀粉样蛋白1-42诱发BV-2细胞产生炎性介质的抑制作用

目的研究吲哚美辛对β淀粉样蛋白1-42（Aβ1-42）刺激小胶质细胞释放炎性介质一氧化氮（NO）及白细胞介素-1β（IL-1β）的抑制作用。方法应用高度纯化的BV-2小胶质细胞作为体外小胶质细胞模型，应用不同浓度吲哚美辛（10^-9，10^-8，10^-7，10^-6，10^-5mol／L）与20μmol／LAβ1—42单独或同时培养12h，测定细胞上清NO及IL，1β含量；RT—PCR法测定BV-2细胞iNOSmRNA及IL-1βmRNA的表达。结果吲哚美辛单独作用对BV-2细胞产生NO、IL-1β及iNOSmRNA、IL-1βmRNA表达无明显作用。Aβl—42可以刺激BV-2细胞产生NO及IL-1β，并增加iNOSmRNA及IL-1βmRNA表达，这种作用均可被吲哚美辛所抑制，在吲哚美辛浓度为10^-7～10^-5mol／L时抑制作用较为明显。结论在体外吲哚美辛可以降低Aβ1—42介导的BV-2细胞iNOSmRNA及IL-1βmRNA表达，从而减少NO及IL-1β的产生，上述抑制作用可能参与了吲哚美辛在阿尔茨海默病治疗中的神经元保护机制。     

髂-股动脉多层螺旋CT测量

目的:采用16层螺旋CTA对髂-股动脉进行测量,为经髂-股动脉介入诊疗提供影像学数据。方法:收集2010年6月～9月符合要求的连续病例350例,按照年龄21～40岁、41～60岁、61～89岁分为A、B、C组。经肘正中静脉注射对比剂后,用16层螺旋CT进行包括盆腔区的增强扫描,薄层重建图像用容积再现技术对髂-股动脉进行三维重建。测量动脉分叉到髂嵴连线、股骨头上缘连线的垂直距离及动脉分叉夹角。相同性别不同年龄组间采用单因素方差分析,相同年龄组不同性别采用两独立样本t检验,不同侧别间采用配对样本t检验。结果:腹主动脉分叉、左右髂总动脉分叉、左右股总动脉分叉到股骨头上缘连线的垂直距离男性A组分别为(132.5±12.8)mm、(87.1±14.9)mm、(88.8±11.3)mm、(43.4±13.7)mm、(41.5±15.0)mm,B组为(126.5±11.6)mm、(84.8±14.2)mm、(89.1±12.9)mm、(44.3±10.1)mm、(46.2±10.1)mm,C组为(115.6±10.7)mm、(80.3±14.3)mm、(82.3±13.6)mm、(39.1±10.0)mm、(40.4±10.0)mm,女性A组分别为(135.4±12.1)mm、(91.3±15.1)mm、(97.4±14.1)mm、(36.5±10.3)mm、(36.2±10.3)mm,B组为(129.8±12.7)mm、(92.7±12.5)mm、(96.0±13.3)mm、(36.5±10.8)mm、(35.8±10.9)mm,C组为(121.2±13.1)mm、(84.0±11.3)mm、(86.3±11.4)mm、(36.4±12.2)mm、(36.9±11.0)mm。除男性左髂总动脉分叉、女性左右股总动脉分叉到股骨头上缘连线的垂直距离外,不同年龄组间差异均有统计学意义(P<0.05)。腹主动脉分叉夹角、左右髂总动脉分叉夹角男性A组分别为(38.2±5.8)°、(26.6±16.9)°、(30.5±10.8)°,B组为(38.1±11.3)°、(25.3±10.8)°、(24.8±11.2)°,C组为(45.1±16.5)°、(25.8±12.5)°、(25.6±13.2)°,女性A组分别为(46.9±10.9)°、(28.2±13.5)°、(28.9±10.2)°,B组为(40.7±11.2)°、(20.3±10.3)°、(21.6±9.7)°,C组为(45.1±11.2)°、(21.0±9.9)°、(27.0±12.1)°,男女腹主动脉分叉夹角、男性左右髂总动脉分叉夹角不同年龄组间差异有统计学意义(P<0.05)。两侧对比三组的髂总动脉分叉点至股骨头上缘连线垂直距离差异均有统计学意义(P<0.05)。结论:16层螺旋CTA可对髂-股动脉进行准确测量,为介入诊疗提供数据。     

Specific antibodies to Trypanosoma cruzi among blood donors in Los Angeles, California

BACKGROUND: Trypanosoma cruzi, the cause of Chagas' disease, is often transmitted by transfusion in Latin America. Previous studies showed that at least 1 in 1000 eligible blood donors at the Los Angeles County+University of Southern California (LAC+USC) Medical Center Blood Bank had specific antibodies to T. cruzi. In June 1993, serologic screening of prospective allogeneic donors at epidemiologic risk for T. cruzi infection was begun voluntarily. STUDY DESIGN AND METHODS: The risk of T. cruzi infection in all eligible donors was assessed by questionnaire. At-risk donors were screened serologically for antibodies to T. cruzi with an enzyme immunoassay, and confirmatory testing was done with a radioimmunoprecipitation assay. RESULTS: During the 29-month study period 1311 (39.5%) of 3320 donors were judged to be at risk for T. cruzi infection. Seven donors (1/475) were reactive by an enzyme immunoassay, and six of these seven (1/ 553) were positive in a radioimmunoprecipitation assay. All radioimmunoprecipitation assay- positive donors had been born in countries in which Chagas' disease is endemic. One person in this group had received a transfusion in his homeland. CONCLUSION: These results demonstrate that a substantive proportion of eligible blood donors at our institution have antibodies specific for T. cruzi and that a commercially available assay can be used to detect these antibodies. Our data suggest that the risk of transmission of T. cruzi by transfusion could be eliminated by serologic testing limited to persons born in or transfused in countries in which Chagas' disease is endemic.     

Cefotaxime-induced immune hemolytic anemia due to antibodies reacting in vitro by more than one mechanism

Until recently, all cephalosporin-induced immune hemolytic anemias appeared to react by a "penicillin-type" drug adsorption mechanism, and hemolysis was extravascular. In 1987 and 1988, the first two cases of cephalosporin-induced immune hemolytic anemia with intravascular hemolysis associated with a so-called immune complex mechanism were reported. This report describes a case of extravascular hemolysis due to a third-generation cephalosporin, cefotaxime, which, to the authors' knowledge, is the first to show in vitro characteristics of both the drug adsorption and the so-called immune complex mechanisms.     

16、20、24、28通道记录对平均平方根值脑电地形图的影响

目的评估不同的电极密度对BEAM数据精确性的影响。方法32名年龄50~59岁正常受试者。采用1和4点插值计算方法计算平均平方根功率BEAM。对比16、20、24、28通道记录的BEAM。结果6个脑电频段61%(11/18)的高功率值电极部位不在16通道的记录电极之内。其中73%(8/11)的高功率电极位于中线电极(Fz、Cz、Pz、OZ)。16通道记录时各个频段的功率值明显降低。增加记录电极,BEAM的精确性增加。结论16通道记录的BEAM存在明显的失真,在低密度电极记录的条件下计算BEAM至少20通道。