氯霉素乙酰基转移酶双抗体夹心ELISA检测方法的建立

目的 建立氯霉素乙酰基转移酶（chloramphenicol acetyltransferase,CAT)双抗体夹心ELISA的实验室检测方法。方法 从质粒pBLCAT6经PCR扩增CAT基因序列，插入到原核表达质粒pGEX-2T中，在大肠埃希菌DH5α中诱导表达；以纯化的融合蛋白GST-CAT为抗原免疫实验用兔，得到的CAT抗血清进行生物素标记，并在此基础上利用生物素链和亲和素放大系统建立双抗体夹心ELISA法，构建不同YY1结合位点突变的HPV16LCRCAT报道质粒，体外瞬时转染真核细胞，提取胞质蛋白，以建立的方法进行CAT表达检测。结果 SDS-PAGE显示表达的GST-CAT融合蛋白相对分子质量约为54000；制备的CAT抗血清可有效地识别原核及哺乳动物细胞表达的CAT蛋白；在不同启动子及调节序列的控制下，利用建立的CAT检测技术证明在瞬时转染的细胞中可诱导2-8倍的CAT表达增强。结论 建立的双抗体夹心ELISA方法可敏感地反映上游序列的启动子活性，以及启动子调节序列变化对启动子活性的影响，使CAT作为报道基因的研究更为简单化。     

Cr Migration Potential and Species Properties in the Soil Profile from a Chromate Production Site in the Groundwater Depression Cone Area

The relationship between the migration process and speciation distribution of Cr is important for the risk assessment in the underground environment. In this work, soil columns were collected from the chromate production site, with a 40-year operation, in the groundwater depression cone area of North China plain. The relationship between chromium pollution features and the geochemical properties of soil was established, and the migration risk of Cr(VI) was assessed based on the Nemerow composite index and Hydrus-1D model. The maximum total Cr concentration in the chromium slag dumping site reached 907 mg/kg, and that in the chromate production workshop was more than 200 mg/kg across the depth. The migration of Cr might be accelerated in the soil with abundant Mn (236–1461 mg/kg) but scarce organic matters (<?0.45%). The Hydrus simulation indicated that Cr(VI) would reach a cumulative flux of 300–729 mg/cm² after 50 years.

     

306例肺癌的淋巴结转移规律

目的 探讨可切除性肺癌的胸内淋巴结转移规律。方法 从l992年1月至2000年l2月，对306例肺癌患者施行根治性切除术和系统性胸内淋巴结清扫，分别记录各区淋巴结的数量、大小、颜色和质地，并进行病理检查。结果 全组共清扫胸内2456个区的46l4个淋巴结，平均每例15.1个。经病理检查证实其中521个区的954个淋巴结存在转移癌。胸内淋巴结的转移率高达61．8％，纵隔淋巴结的转移率高达43．5％。围绕肺门或肺根部的11、10、7、5和4区淋巴结的转移频度比远离肺根部的9、6、3、2、l区淋巴结高。小细胞肺癌的淋巴结转移率明显高于非小细胞肺癌(P＜0.01)。淋巴结转移率与淋巴结的大小、颜色和质地均有密切关系(尸＜0.00l，P＜0.00l，P＜0.001)。结论 多数肺癌的淋巴结转移遵循由近及远、自下而上、由肺内经肺门再向纵隔的顺序转移规律，少数纵隔淋巴结转移呈“跳跃式”。肺切除术时施行系统性胸内淋巴结清扫是必要的。     

白藜芦醇抑制胆囊癌细胞生长与诱导细胞凋亡的实验研究

目的:探讨白藜芦醇(Res)对胆囊癌细胞(GBC)和正常成纤维细胞(3T3)体外增殖的影响,进而观察Res对GBC和3T3细胞凋亡的影响.方法:MTT法测定肿瘤细胞生长抑制率;流式细胞术分析细胞周期,检测细胞凋亡;SABC法检测细胞bcl-2、c-myc、p53蛋白表达.结果:Res呈浓度依赖性抑制GBC细胞的生长与增殖(P＜0.01),抑制率最高可达54%.Res能明显诱导GBC细胞凋亡,凋亡率最高为30.52%;处理组较对照组G1期细胞由34.88%上升至55.47±3.95%,S期细胞减少8.41%～17.54%,呈明显的G0/G1期阻滞现象.GBC细胞的bcl-2、c-myc基因蛋白表达降低,而p53基因蛋白表达增强.结论:Res能通过诱导GBC细胞凋亡而抑制其生长与增殖,但对3T3细胞无此作用.     

Visceral hyperalgesia and intestinal dysmotility in a mouse model of postinfective gut dysfunction

BACKGROUND & AIMS: We established the concept that transient enteric infection may lead to persistent gut dysfunction, evident in vitro, in nematode-infected mice. The present study determined whether gut dysfunction in this model involves motor and sensory changes reminiscent of changes found in patients with postinfective irritable bowel syndrome (PI-IBS) and investigated underlying mechanisms. METHODS: Mice infected up to 70 days previously with Trichinella spiralis (Tsp) underwent videofluoroscopy with image analysis to assess upper gastrointestinal motility. Pseudoaffective responses to colorectal distention (CRD) were assessed using a barostat and validated by single fiber recordings from spinal nerves during CRD. Tissues were examined at different time points for histology, immunohistochemistry, and cytokine analysis. Some mice received dexamethasone intraperitoneally on days 23-25 PI or Tsp antigen orally on days 29, 43, and 57 PI. RESULTS: From day 28 PI, no discernible inflammation was present in the gut. Frequency and propagation velocity of intestinal contractions decreased, and retroperistalsis increased at days 28 to 42 PI. CRD induced an allodynic and hyperalgesic response in PI mice, which was accompanied by increased single unit discharge. Gavage of Tsp antigen induced T-cell responses and sustained gut dysfunction for 70 days PI. Administration of dexamethasone postinfection normalized dysmotility and visceral hyperalgesia. CONCLUSIONS: Long-lasting gut dysmotility and hyperalgesia develop in mice after transient intestinal inflammation. These changes are maintained by luminal exposure to antigen and reversed by corticosteroid treatment. The findings prompt consideration of this as a model of PI-IBS.     

Pharmacodynamics and pharmacokinetics of PLGA-based doxorubicin-loaded implants for tumor therapy

The traditional systemic chemotherapy through intravenous infusion of doxorubicin (DOX) has many side effects. The aim of this study was to develop a PLGA-based DOX-loaded implant and to evaluate the efficacy and drug metabolism distribution of the implant in intratumoral chemotherapy for osteosarcoma (OS). In this study, implants containing DOX, poly(d,l-lactide-co-glycolide), and polyethylene glycol 4000 were prepared by melt-molding method. Then, the antitumor activity and systemic drug distribution of the implants were tested in a K7M2 OS bearing mouse model. The scanning electron microscope images showed that DOX was uniformly dispersed in the polymer matrix. Both the in vitro and in vivo release profiles of implants are characterized by three-phase release. Implantation of DOX-loaded implants into tumors can inhibit tumor growth in a dose-dependent manner. The pharmacokinetic behavior shows that intratumor chemotherapy through implants has a much higher drug concentration in tumors than in normal tissues, which may be the reason for improving antitumor activity and reducing systemic side effects. In summary, the drug release of the implants prepared in this study is sustained and stable, which promotes long-term local accumulation of drugs in tumors, improves the efficacy of chemotherapy and has low toxicity to normal tissues.     

IFN-α对SNI神经源性疼痛模型小鼠中的镇痛作用

目的:研究IFN-α2a在小鼠SNI神经痛模型中的镇痛作用。方法:采用SNI疼痛模型小鼠,以VonFrey Filaments刺激法和冷盘法测定腹腔给予IFN-α2a的镇痛作用,并测定阿片肽受体拮抗剂纳洛酮对其镇痛作用的阻断。结果:①IFN-α2a的给药剂量为1 000 U/g体重时,基本无镇痛作用;剂量为5 000 U/g体重时,给药后30 min有明显的镇痛作用,持续5-20 min;剂量为10 000 U/g时,镇痛作用可维持50-60 min。②纳洛酮可以完全阻断IFN-α2a的镇痛作用。结论:①IFN-α2a在小鼠SNI模型中具有镇痛作用,且呈剂量效应。②IFN-α的镇痛作用可能通过阿片受体传导。     

青少年学习成绩与心理卫生关系的研究

目的 了解青少年学习成绩与卫生之间的关系。方法 选择4所不同的类型的中学，根据学习成绩将入组学生分为4个组，用青少年自评行为量表（YSR）作为主要研究工具。结果 4组学生YSR量表各因子分及总分之间比较均有显著差异。3类不同类型党校的学生YSR量表部分因子及总分之间比较有显著差异。学习成绩较差的学生具有发生心理卫生问题的高危险性，因子分析显示行为问题发生率较高，其次是学习成绩优秀的学生，表现为情绪问题发生率较高。结论 研究结果显示学习成绩与青少年心理卫生状况具有密切关系。     

非吸烟型肺癌分子病因学研究进展

肺癌是目前全世界范围内癌症死亡的最主要原因,尽管吸烟被认为是罹患肺癌的重要元凶,但约10%-15%的肺癌患者终生无吸烟史,最近国外一项流行病学调查表明全世界范围内约15%男性和53%女性肺癌患者从不吸烟[1].目前在全球范围内统计约90%男性肺癌发生与吸烟有关,而女性发生肺癌与吸烟相关性比率存在一定区域差别,在美国约75%、欧盟约85%女性肺癌与吸烟有关,而亚洲国家和地区的女性肺癌与吸烟相关报道则与西方国家统计差别较大,在韩国仅有约25%、香港约56%女性肺癌患者为吸烟者[2,3].