用分子克隆技术构建D12S391基因座等位基因分型标准物及群体遗传学研究

目的 解决长期困扰短串联重复序列（short tandem repeat,STR）分型上存在的准确性和标准化问题。方法 先用PCR扩增出D12S391基因座的9个等位基因片段，将其插入pUC重组质粒中，经DNA测序分析证实插入片段的结构及大小，用国际标准将插入的等位基因片段进行命名，最后经转染、扩大培养、扩增及再鉴定后，制备出标准的D12S391等位基因分型标准物。结果 应用此法制备出大量的D12S391基因座等位基因分型标准物，并将其用于调查该基因座在德国Mainz地区、日本Miyazaki地区及中国成都汉族、北京汉族、新疆维吾尔族和甘肃回族6个群体中的基因型分布频率。D12S391基因座在各群体中均有较高的多态性，其非父排除概念及个人识别能力分别为0.609-0.786和0.940-0.952。结论 该法制备的STR基因座等位基因分型标准物在法医科学实践中应用价值极高，D12S391基因座是一个非常适合于群体遗传学研究和法医科学应用的遗传标记。     

移植骨髓间充质干细胞肝癌大鼠细胞凋亡及炎症因子的动态变化

BACKGROUND:Bone marrow mesenchymal stem cell transplantation has not been thoroughly reported on its effects on apoptosis in hepatoma carcinoma cells and inflammatory factor level. OBJECTIVE:To investigate the effect of rat bone marrow mesenchymal stem cells on dynamic change of inflammatory factors and cell apoptosis during hepatocarcinogenesis. METHODS:Sixty healthy Sprague-Dawley rats were divided randomly into healthy group (n=30), control group (n=30) and transplantation group (n=30). Healthy group was given ordinary feed and normal water, while other groups were given diethylnitrosamine solution in drinking water to induce liver cancer models. Then, rats in the transplantation group were subjected to bone marrow mesenchymal stem cell transplantation via the tail vein. Two weeks after cell transplantation, CXCL5, interleukin-8 and interleukin-6 levels were tested by ELISA, mRNA level of hepatocyte nuclear factor 1α detected by RT-PCR, expression of Bcl-2 and Bax in liver tissue measured by immunohistochemical method, and liver cancer cell apoptosis index detected by TUNEL technique. RESULTS AND CONCLUSION:After modeling, the expressions of CXCL5, interleukin-8 and interleukin-6 in the control group were significantly higher than those in the healthy group (P < 0.05), while these indexes were reduced significantly after bone marrow mesenchymal stem cell transplantation (P < 0.05) and close to the normal levels (P > 0.05). Bone marrow mesenchymal stem cell transplantation significantly up-regulated the mRNA level of hepatocyte nuclear factor 1α in the liver tissue that was decreased obviously after modeling (P < 0.05). In addition, the expression of Bcl-2 was reduced, while the expression of Bax and the apoptosis index increased significantly in the transplantation group compared with the control group (P < 0.05). These findings indicate that bone marrow mesenchymal stem cell transplantation contributes to hepatocyte differentiation and regeneration in liver cancer rats by reducing serum inflammatory factor levels and promoting apoptosis in hepatoma carcinoma cells.     

Collagen scaffolds modified with CNTF and bFGF promote facial nerve regeneration in minipigs

Most experiments of peripheral nerve repair after injury have been conducted in the rodent model but the translation of findings from rodent studies to clinical practice is needed partly because the nerve regeneration must occur over much longer distances in humans than in rodents. The reconstruction of long distance nerve injuries still represents a great challenge to surgeons who is engaged in peripheral nerve surgery. Here we used the functional nerve conduit (collagen scaffolds incorporated with neurocytokines CNTF and bFGF) to bridge a 35 mm long facial nerve gap in minipig models. At 6 months after surgery, electrophysiology assessment and histological examination were conducted to evaluate the regeneration of peripheral facial nerves. Based on functional and histological observations, the results indicated that the functional collagen scaffolds promoted nerve reconstruction. The number and arrangement of regenerated nerve fibers, myelination, and nerve function reconstruction was better in the CNTF + bFGF conduit group than the single factor CNTF or bFGF conduit group. The functional composite conduit, which exhibited favorable mechanical properties, may promote facial nerve regeneration in minipigs effectively.     

Kinetics of Memory B Cell and Plasma Cell Responses in the Mice Immunized with Plague Vaccines

In our previous studies, we found that plague vaccines can induce long‐term antibody response, but no significant antibody boost was observed when the immunized mice were challenged with virulent Yersinia pestis. However, a booster vaccination of subunit vaccine on week 3 after primary immunization elicited a significantly higher antibody titre than a single dose, whereas no significant antibody titre difference was observed between a single dose and two doses of EV76 vaccination. To address these issues, in this study, we first investigated the kinetics of memory B cells and plasma cells in the mice immunized with EV76 or F1 protein by flow cytometry and then determined antibody titre in five groups of mice immunized with various vaccination strategy. The results showed that memory B cells dropped to a low level at day 56 after primary immunization. In contrast, plasma cells were maintained for more than 98 days. The group with primary immunization of EV76 and booster of F1 antigen developed a higher antibody titre than the group with immunization of F1 antigen and booster of EV76. This result supports a hypothesis that an excess of antigens can neutralize pre‐existing antibodies, and then the redundant antigen induces antibody boost. Taken together, a boost of antibody titre after revaccination may be dependent on the existence of memory B cells and an excess of antigen vaccination. In addition, this study showed an ideal immunization strategy that involves first immunization with a live attenuated vaccine, such as EV76, and then with a subunit vaccine.     

Dectin-1-CD37 association regulates IL-6 expression during Toxoplasma gondii infection

Toxoplasma gondii can establish chronic infection and is characterized by the formation of tissue cysts in the brain. Although T. gondii can infect any kind of nucleated cells, macrophages and related mononuclear phagocytes are its preferred targets in vivo. Microglial cells are the resident macrophages in the central nervous system. It has been reported that CD37, a tetraspanin molecule, is expressed exclusively in the immune system; Dectin-1, an important pattern-recognition receptor, is expressed on the surface of murine primary microglia. The Dectin-1-CD37 association can affect Dectin-1-mediated IL-6 secretion. However, there is no report concerning the relationship among the expressions of Dectin-1, IL-6, and CD37 during T. gondii infection. In the present study, Kunming outbred mice were infected with Prugniaud (Pru), a type II strain of T. gondii by oral gavage, and BV-2 murine microglial cells were cocultured with RH tachyzoites of T. gondii. By H&E and immunohistochemical staining, the results showed that marked inflammation and a significantly increased activation of Iba1-positive microglial cells were observed in the brain tissues of mice infected with T. gondii Pru strain at 5 weeks postinfection (p.i.) in comparison of uninfected controls. Using quantitative real-time PCR detection, Dectin-1 messenger RNA (mRNA) expressions were significantly upregulated in both brains at 3 (P?<?0.01), 5 (P?<?0.01), 7 (P?<?0.01), and 9 (P?<?0.05) weeks p.i. and spleens at 3, 5, 7, and 9 weeks p.i. (P?<?0.01). IL-6 expressions showed similar dynamic tendency as that of Dectin-1 in both the brains and spleens at the same times in comparison of uninfected controls; CD37 expressions were significantly increased in the brain tissues at all the times (P?<?0.01) and no significant differences in the spleens at 3 weeks p.i. but significantly downregulated in the spleens at 5, 7, and 9 weeks p.i. (P?<?0.01). In vitro study showed that compared with uninfected controls, the mRNA expressions of Dectin-1 at 2, 4, 8, and 10 h (P?<?0.01); IL-6 at 8 and 10 h (P?<?0.01); and CD37 at 4 (P?<?0.05), 8 (P?<?0.01), and 10 h (P?<?0.01) were significantly upregulated in BV-2 murine microglial cells stimulated with RH tachyzoites of T. gondii. Our data suggested that the expression of Dectin-1 was positively correlated with that of IL-6 in toxoplasmic encephalitis (TE) mouse model; Dectin-1 interaction with tetraspanin CD37 regulated IL-6 expression in both the brain tissues of TE mouse model and in the T. gongdii-infected BV-2 murine microglial cells.     

Neural mechanisms of oxytocin receptor gene mediating anxiety-related temperament

A common variant (rs53576) of the OXTR gene has been implicated in a number of socio-emotional phenotypes, such as anxiety-related behavior. Previous studies have demonstrated that A-allele carriers have higher levels of physiological and dispositional stress reactivity and depressive symptomatology compared to those with the GG genotype, but the mediating neural mechanisms remain poorly understood. We combined voxel-based morphometry and resting-state functional connectivity analyses in a large cohort of healthy young Chinese Han individuals to test the hypothesis that the OXTR gene polymorphism influences an anxiety-related temperamental trait, as assessed by the harm avoidance subscale from the Tridimensional Personality Questionnaire via modulating the gray matter volume and resting-state functional connectivity of the brain, especially the limbic system. We revealed that female subjects with the AA genotype showed increased harm avoidance scores relative to G-carrier females. We also found that, compared to female individuals with the GG/GA genotype, female individuals with the AA genotype exhibited significantly smaller amygdala volumes bilaterally (especially the centromedial subregion), with a trend of allele-load-dependence. Compared to female individuals with the GG/GA genotype, female subjects with the AA genotype demonstrated reduced resting-state functional coupling between the prefrontal cortex and amygdala bilaterally, also with an allele-load-dependent trend. Furthermore, the magnitude of prefrontal-amygdala coupling in the left hemisphere was positively correlated with harm avoidance scores in female subjects. Our findings highlight a possible neural pathway by which a naturally occurring variation of the OXTR gene may affect an anxiety-related temperamental trait in female subjects by modulating prefrontal-amygdala functional connectivity.     

乙酰半胱氨酸纳米活性炭缓释微囊对大鼠非酒精性脂肪性肝炎抗氧化作用的影响

目的 探讨乙酰半胱氨酸纳米活性碳缓释微囊（ACNAC）对非酒精性脂肪性肝炎（NASH）大鼠肝脏抗氧化能力的影响.方法 通过高脂饮食12周诱导建立NASH大鼠动物模型,分别给予ACNAC高、中、低每日不同剂量（800 mg/kg、400 mg/kg和200 mg/kg）与易善复（0.692 mg/kg）、乙酰半胱氨酸（400 mg/kg）连续灌胃8周后,检测血清生化指标、肝匀浆丙二醛（MDA）含量、总超氧化物歧化酶（SOD）活性、还原型谷胱甘肽（GSH）、谷胱甘肽过氧化物酶（GSH-Px）活性及肝脏病理指标.结果 ACNAC中剂量组与高脂组相比,血清ALT、AST明显下降（P＜0.01 、P ＜0.05）,且优于易善复组（P＜0.05）.血清TCHOL 、TG、LDL-C和CR检测结果差异虽无统计学意义,但其数值上ACNAC明显低于高脂组,且优于易善复组和NAC组.ACNAC高、中、低三组与高脂组相比,SOD活力明显升高（P ＜0.01） 、GSH含量明显升高（P＜0.01）,ACNAC中剂量组与高脂组比较GSH-PX活性明显升高（P＜0.05）但略低于易善复组（P＜0.01））.结论 相关剂量的乙酰半胱氨酸纳米活性炭缓释微囊可增强非酒精性脂肪性肝炎大鼠的抗氧化能力.     

Study on In Vitro Anti-Tumor Activity of Bidens Bipinnata L. Extract

We studied the in vitro anti-tumor activity of Bidens Bipinnata L. extract. MTT assay was used to investigate the inhibitory effect of different concentrations of the extracts on human hepatocellular carcinoma (HepG2) cell lines and human cervical carcinoma (Hela) cell lines, and the IC₅₀ values were calculated. The Bidens Bipinnata L. extract had different degrees of inhibitory effects on these two cells, and when exposure time was 48 h, the inhibition rate reached its peak, with IC₅₀ values of 14.80 µg/mL and 13.50 µg/mL respectively. The Bidens Bipinnata L. extract had a good inhibitory effect on human HepG2 cell lines and Hela cell lines, and thus has certain development prospects.     

混合式教学与评估方法在系统解剖学教学中的应用*

系统解剖学课程内容繁杂,知识点多,需要记忆的信息量大,上课学时短,课程紧等特点,往常学生都是死记硬背,导致学生对解剖学学习兴趣不高,学习效果不好,及格率低。这种传统教学模式已经不能适应现代化的信息技术与教学方法的不断融合与创新。伴随着现代信息技术的迅猛发展,以及传统教学理念的转变和教学方式的多元化.     

电刺激对背根节神经元/Schwann细胞联合培养体系髓鞘蛋白P0表达的影响

目的:建立体外背根节神经元与Schwann细胞联合培养模型,观察短时低频电刺激对Schwann细胞髓鞘蛋白表达的影响。方法:培养和纯化背根节神经元与Schwann细胞,制成背根节神经元/Schwann细胞联合培养体系。于L-ascorbic acid诱导的同时,施予低频电刺激(20Hz,100μs,3V),持续作用1h,分别于L-ascorbicacid诱导后第0,2,4,8和10d取各组培养基上清以ELISA测定其中脑衍生物神经生长因子(BDNF)的水平。另外,于诱导后第7d和14d检测培养体系中髓鞘蛋白P0的表达。结果:电刺激组各时间点BDNF的浓度较对照组显著升高(P0.01)。经电刺激作用后,联合培养体系中P0表达上调(P0.05)。然而,电刺激结束后在培养液中加入TrkB-Fc,P0的表达水平则显著降低(P0.05)。结论:在神经元存在的条件下,短时低频电刺激可促进离体Schwann细胞合成P0,初步认为该作用通过刺激神经元分泌BDNF增多所致。