Leishmania identification by PCR of Giemsa-stained lesion imprint slides stored for up to 36 years

This study examined the ability of PCR to amplify Leishmania DNA, stored on Giemsa-stained slides, from American cutaneous leishmaniasis (ACL) patients. In total, 475 slides stored for up to 36 years were obtained from an outpatient clinic in a Brazilian ACL-endemic region, and Leishmania DNA was amplified from 395 (83.2%) of the DNA samples using primers specific for the minicircle kinetoplast DNA. Restriction fragment length polymorphism analysis of these amplicons demonstrated that Leishmania (Viannia) braziliensis was the only species present in these samples. The results demonstrated that archived Giemsa-stained slides can provide a Leishmania DNA source for performing clinical and epidemiological studies of leishmaniasis.     

Reactive oxygen species and human spermatozoa: physiology and pathology

The role of reactive oxygen species (ROS) in the pathophysiology of human sperm function has been emphasized in recent years. ROS production in semen has been associated with loss of sperm motility, decreased capacity for sperm–oocyte fusion and loss of fertility. There is a current presumption that the most prolific source of ROS in sperm suspensions is an NADPH oxidase located in leukocytes or in spermatozoa which produces superoxide which is further converted to peroxide by the action of superoxide dismutase. Hydrogen peroxide has been recognized as the most toxic oxidizing species for human spermatozoa, which are very sensitive to lipid peroxidation owing to the high content of polyunsaturated fatty acids in their plasma membrane, though this is not the sole mechanism by which sperm function might be impaired by ROS. Although the excessive production of ROS is detrimental to human spermatozoa, there is a growing body of evidence which suggests that ROS are also involved in the physiological control of some sperm functions. This review focuses on the nature and source of the ROS generated by human spermataozoa as well as their operational mechanisms and their effects, which may be detrimental or beneficial.     

On the quantification of prothrombin from different species using echis carinatus as activator

The generation of thrombin-like activity from rat, human, bovine and mouse prothrombin by Echis carinatus venom (ECV) treatment was compared using a partially purified system (i.e. whole ECV and isolated prothrombin). A rapid increase in coagulant activity was obtained within 0.5 to 2 min., being constant upon further incubation for 60 min. A large variation in coagulant activity of the ECV generated thrombin from the four species was found, whereas no differences were found for the amidolytic activities. The coagulant activities of the ECV generated thrombin was also low compared with the corresponding thrombin activities obtained by physiological activation. Coagulant activity of the ECV generated thrombin levelled off at increasing concentration of prothrombin in the sample as measured by the one-stage coagulation assay. By measuring amidolytic activity a linear relationship to the concentration of prothrombin was found, however. These findings indicate that ECV converts prothrombin from the four different species to a thrombin-like protein with properties distinct from -thrombin. The lack of linearity in the ECV generated clot activity with increasing concentration of prothrombin could be explained by assuming a dimerization of the thrombin like protein molecules making them less accessible to fibrinogen. The significance of these observations for the quantification of prothrombin from different species is discussed.     

PTEN基因敲除降低辐射敏感性及其机制

目的 探讨PTEN基因敲除对辐射敏感性的影响及机制。方法 采用流式细胞术检测MEF1和MEF1/PTEN^－/－细胞内ROS水平;采用Western blot方法,检测H₂O₂和DPI预处理后AKT激酶的表达变化;采用细胞克隆形成率试验分析细胞对⁶⁰Co γ射线的敏感性。结果 PTEN基因敲除后细胞ROS水平增加,辐射敏感性降低。H₂O₂和DPI预处理后影响MEF1细胞AKT激酶活性,但对MEF1/Pten^－/－细胞无影响。 结论 PTEN基因敲除阻断了ROS对AKT的介导,AKT激酶持续活化,可能是辐射敏感性降低的重要原因。     

颈椎病与中医辨证关系的探讨(附100例分析)

目的:探讨颈椎病与中医分型的辨证关系。方法:对100例该病的影像表现与中医分型进行系统分析。结果:主要临床表现颈部活动受限,颈、肩、背部疼痛,常伴头痛、头晕、视物模糊、耳鸣等症状。风寒型以软组织所致颈曲改变为主。肝肾亏虚型、痰湿交阻型以骨质增生、椎间隙及椎间孔狭窄为主。结论:X线、CT是本病首选检查方法,能与中医辨证有机结合,对中西医治疗有重要意义。     

谷胱甘肽、自由基在砷剂诱导卵巢癌细胞凋亡中的作用

目的　观察谷胱甘肽、自由基在砷剂诱导卵巢癌细胞凋亡中的作用。方法　砷剂孵育卵巢癌细胞 4 8h后 ,琼脂糖凝胶电泳及流式细胞仪检测细胞凋亡 ,分光光度法检测细胞内谷胱甘肽、活性氧及丙二醛含量。结果　砷剂具有诱导卵巢癌细胞凋亡作用 ,砷剂诱导后细胞内谷胱甘肽含量减少 (P <0 .0 1)、活性氧及丙二醛含量增加(P <0 .0 5 )。结论　氧化还原系统的改变是砷剂诱导卵巢癌细胞凋亡的重要途径之一。     

17β-雌二醇对子宫内膜异位症患者在位子宫内膜间质细胞β-catenin mRNA和蛋白表达的影响

目的研究17β-雌二醇(17β-E2)对子宫内膜异位症(内异症)患者在位子宫内膜间质细胞β-catenin mRNA和蛋白表达的影响,探讨Wnt/β-catenin信号通路在介导雌激素促进内异症发生发展的作用。方法体外分离培养内异症患者在位子宫内膜间质细胞。用不同浓度17β-E2处理子宫内膜间质细胞48 h;此后选用10-10mol/L 17β-E2处理子宫内膜间质细胞12、24和48 h,逆转录聚合酶链反应(RT-PCR)和免疫印迹法(Western blotting)检测17β-E2处理前后子宫内膜间质细胞β-catenin mRNA和蛋白的表达水平。同法分析雌激素受体拮抗剂ICI182,780(10-6mol/L)对17β-E2促进β-catenin mRNA和蛋白表达的影响。免疫组织化学染色观察17β-E2作用后β-catenin在子宫内膜间质细胞中的定位。结果17β-E2能明显促进内异症患者在位子宫内膜间质细胞β-catenin mRNA和蛋白的表达,并呈剂量和时间依赖性,于10-10mol/L作用48 h最明显。雌激素受体拮抗剂ICI182,780能明显抑制17β-E2对子宫内膜间质细胞β-catenin mRNA和蛋白的表达。免疫组织化学染色发现17β-E2能促进β-catenin在子宫内膜间质细胞核内的表达。结论雌激素可能通过激活Wnt/β-catenin信号通路促进内异症在位子宫内膜的异位种植。     

Effects of cepharanthin on neutrophil chemotaxis, phagocytosis, and reactive oxygen species generation.

The effects of cepharanthin on inflammatory parameters such as neutrophil chemotaxis, phagocytosis and reactive oxygen species (ROS) generation, were examined. Cepharanthin significantly decreased the levels of O2-, H2O2, and OH. generated by neutrophils. H2O2 and OH. generated in a cell-free, xanthine-xanthine oxidase system were also reduced in the presence of cepharanthin. However, the drug did not affect neutrophil chemotaxis or phagocytosis. The present study indicates that cepharanthin is an effective ROS scavenger, exerting its anti-inflammatory action by reducing the potent ROS species excessively generated in tissues and organs, especially at the sites of inflammation.     

Ontogeny of behavioral sensitization to cocaine

The ontogeny of the behavioral effects of acute cocaine administration and behavioral sensitization to cocaine in rat pups was investigated. Acute behavior stimulating effects of cocaine were observed in pups as young as 7 postnatal days (PND) old, although they needed a higher dose of cocaine than adult rats to evoke the same motor effects. An adult dose-response curve pattern of stereotypy and locomotion to acute cocaine treatment was observed at PND 21, and of rearing at PND 28. Rats aged PND 7, 14, 21, 28, and 56 received repeated injections of saline or cocaine (15 mg/kg) twice a day for 5 consecutive days. After a 3-week period of abstinence, sensitization to a challenge dose of cocaine was assessed. Cocaine-induced stereotyped behavior was enhanced significantly only in rats in which cocaine pretreatment was initiated on PND 21, 28, and 56, but not earlier on PND 7 and 14. Adult female rats given repeated cocaine injections on PND 56–60 showed significantly greater sensitization than males, but no such sex difference was observed in pups given cocaine repeatedly on PND 21–25 or 28–32. These results show clearly that cocaine-induced behavioral sensitization in rats occurred only when subchronic cocaine administration was commenced on PND 21 or later.