外源核苷酸对免疫抑制小鼠胸腺细胞DNA损伤的影响

目的:检测外源核苷酸对经环磷酰胺诱导的免疫抑制小鼠胸腺细胞DNA损伤的影响。方法:采用18～20 g昆明种小鼠30只,雌雄各半,随机分成阴性对照组(NEC)、阳性对照组(POC)和核苷酸组(NTG),每组10只。NEC组和POC组小鼠均饲喂半纯合无核苷酸的基础日粮,NTG组则在基础日粮中添加0.25%的核苷酸,实验期为21 d。在实验结束前18 h POC组和NTG组小鼠按照150mg/kg bw的剂量腹腔注射环磷酰胺,NEC组注射生理盐水,实验结束时测定脾脏和胸腺脏器指数,并取胸腺细胞,做单细胞凝胶电泳,观察细胞DNA损伤情况。结果:在基础日粮中添加核苷酸对小鼠免疫器官重量没有显著影响(P>0.05),但能极显著降低受损胸腺细胞百分率(P<0.01)和受损细胞DNA尾长(P<0.01)。结论:外源核苷酸能显著降低免疫抑制小鼠受损胸腺细胞百分率和损伤程度。     

DNA免疫研究进展

DNA免疫可诱导机体全面的免疫应答,且与传统的蛋白免疫相比具有制作简单、经济安全、易于贮存运输等优点。自发现以来已越来越引起人们的重视,成为第三代疫苗,并广泛用于各种感染性疾病的防治研究中。作者主要综述DNA免疫作用机理,可能的影响因素,及其在抗体制备、婴儿免疫、粘膜免疫及表达文库免疫等方面的应用。此外,还介绍了增强DNA免疫效果的策略。     

微卫星及在血友病甲基因诊断中的研究进展

血友病甲是一种最为常见的遗传性出血性疾病,微卫星在其基因诊断中发挥着越来越重要的作用。     

Rapid genotyping of newborn gene mutant mice

One important aspect of utilizing transgenic mice is the need to genotype them in order to distinguish mice that carry a disrupted gene or a transgene from mice that do not. Current methods for genotyping include isolation of genomic DNA from tail biopsies followed by PCR amplification. Particularly, both digestion of tail tissue using proteinase K as well as resuspension of purified DNA are time-consuming and were usually carried out overnight. Here, we describe a rapid and robust method for the genotyping of bdnf targeted mice which allows us to determine the genotype of newborn mice at the day of birth within 6 h. After a freezing–thawing step tail tissue is digested in less than 2 h, and the DNA is precipitated, resuspended and ready for PCR in about 60 min. The method could be easily adapted to a variety of different mutant mice and especially should benefit neuroscientists interested in using animals with known genotype very early in postnatal development.     

重亚硫酸盐修饰直接测序技术检测p16基因甲基化的研究

目的建立稳定的重亚硫酸盐直接测序技术，检测p16基因甲基化状况。方法提取正常人全血基因组DNA．建立起稳定的重亚硫酸盐直接测序平台，利用该技术检测结直肠癌细胞株pl6基因甲基化状况。结果应用列联表的Fisher，Exact Test比较3种纯化方法的测序结果，乙醇／醋酸钠和过柱纯化与SAP—ExonI纯化法比较，测序结果差异有统计学意义（P〈0．05）；应用重亚硫酸盐直接测序技术，可检测出p16基因目的片段中CpG岛所有CpG位点的甲基化状况。结论应用SAP—ExonI纯化法，建立了稳定的重亚硫酸盐直接测序技术，并可检测出目的片段中CpG岛所有CpG位点的甲基化状况。     

Human carcinogenic risk evaluation: an alternative approach to the two-year rodent bioassay.

An approach to the evaluation of carcinogenic risk resulting from exposure to a given chemical is presented in place of a reliance on two-year rodent bioassays. An emphasis is placed on evaluation of the potential DNA reactivity or increased cell proliferation that can be produced by a chemical. The special cases of immunosuppressive and estrogenic chemicals are considered. These evaluations are proposed to involve a combination of in vitro assays, computerized models, and short-term (up to 13 weeks) bioassays in rodents. The emphasis is on mechanistic understanding and evaluation of the dose response and relevance to humans.     

Mitochondrial DNA Copy Number Is Associated With Treatment Response and Cognitive Function in Euthymic Bipolar Patients Receiving Valproate

BackgroundBipolar disorder (BD) is associated with cognitive impairment and mitochondrial dysfunction. However, the associations among mitochondrial DNA copy number (MCN), treatment response, and cognitive function remain elusive in BD patients.MethodsSixty euthymic BD patients receiving valproate (VPA) and 66 healthy controls from the community were recruited. The indices of metabolic syndrome (MetS) were measured. Quantitative polymerase chain reaction analysis of blood leukocytes was used to measure the MCN. Cognitive function was measured by calculating perseverative errors and completed categories on the Wisconsin Card Sorting Test (WCST). The VPA treatment response was measured using the Alda scale.ResultsBD patients had significantly higher MCN, triglyceride, and C-reactive protein (CRP) levels, waist circumference, and worse performance on the WCST than the controls. Regression models showed that BD itself and the VPA concentration exerted significant effects on increased MCN levels. Moreover, the receiver operating characteristic curve analysis showed that an MCN of 2.05 distinguished VPA responders from nonresponders, with an area under the curve of 0.705 and a sensitivity and specificity of 0.529 and 0.816, respectively. An MCN level ≥2.05 was associated with 5.39 higher odds of being a VPA responder (P = .006). BD patients who were stratified into the high-MCN group had a higher VPA response rate, better WCST performance, lower CRP level, and less MetS.ConclusionsThe study suggests a link between the peripheral MCN and cognitive function in BD patients. As an inflammatory status, MetS might modulate this association.