中国侏罗纪新发现的神、仙二兽为哺乳动物起源研究再添新证

正2014年9月10日,中科院古脊椎动物与古人类研究所毕顺东、王元青和孟津等研究人员在英国《自然》杂志报道了在中国发现的、年代为1亿6千万年前的6件相当完整的哺乳动物化石,并命名了神兽、仙兽两个新属的三个新种:陆氏神兽(Shenshou lui)、玲珑仙兽(Xianshou linglong)和宋氏仙兽(Xianshou songae)。这些属种,都属于已经绝灭的"贼兽目",一个特别的、迄今为止所知甚少的中生代哺乳动物类群。哺乳动物起源是进化生物学中的重要科学问题,也是学术界长期     

溶瘤病毒载体研究进展

溶瘤病毒(oncolytic virus,OVs)疗法是治疗肿瘤的一种新方法,它可通过直接杀死肿瘤细胞并引起机体的免疫反应发挥作用.然而天然溶瘤病毒有一定的局限性,因此需将各种不同的病毒作为载体,通过基因修饰的方法增强或减弱病毒毒力并导入新的功能性基因,以提高其溶瘤作用.目前可以作为溶瘤病毒载体的有单纯疱疹病毒、腺病毒、牛痘病毒、水泡性口炎病毒、麻疹病毒、腮腺炎病毒、脊髓灰质炎病毒等.这些病毒载体均可通过不同的基因修饰方法,靶向性感染并杀死不同的肿瘤细胞,获得较好的溶瘤作用.本文综述了几种溶瘤病毒载体的基因修饰方法,以及修饰后的溶瘤效果.     

应用TDI-FP技术分析宫颈癌组织HPV16 E7基因A647G点突变

模板指导的末端碱基掺入反应结合荧光偏振检测技术(template direct dye-terminator incorporation with fluorescence- polarization,TDI-FP) 是SNP检测新技术. 应用TDI-FP方法分析中国陕西HPV16阳性宫颈组织HPV16 E7基因第647位核苷酸A→G热点突变(即A647G),首先在HPV16阳性的91例宫颈癌及49例正常/宫颈炎妇女宫颈DNA标本中,PCR扩增含647位点在内的HPV16 E7部分基因, 然后将紧邻647位点5′端的寡核苷酸探针与PCR产物内的模板杂交,并延伸一个与647位点碱基互补的荧光标记碱基：TAMRA-ddTTP或R110-ddCTP. 用荧光偏振仪读取荧光偏振 (FP) 值,根据升高的相应FP值判断647位点碱基. 结果表明,宫颈组织HPV16 E7 A647G的总体检出率为35.71% (50/140). 宫颈癌组的A→G突变率为42.86% (39/91),显著高于正常/宫颈炎组22.45% (11/49) 的突变率 (x2 = 5.778, P = 0.016),两组间的OR值为2.59 (95% CI = 1.17~5.71). 提示TDI-FP 可用于HPV有意义点突变的分析;我国陕西地区妇女HPV 16 A647G突变率及其对宫颈癌的警示性与其他地区相比有明显差异,该地区携带此突变病毒株的妇女患宫颈癌的风险可能较高     

HPV转基因动物研究进展

人乳头状瘤病毒(Human papillomavirus,HPV)可以引起人宫颈癌、肛门生殖器癌、尖锐湿疣等多种良、恶性肿瘤,严重威胁人类健康。然而,由于HPV严格的嗜人类上皮组织的特性,自然状态下不感染任何实验动物,给研究HPV的感染过程、致病机理,以及开发治疗HPV感染的药物等带来了困难,因此,研究HPV的动物模型显得尤为重要。     

微波快速石蜡切片技术及其在肾穿刺活检中的应用

肾穿刺活检技术推动了肾脏病理的迅速发展,使肾脏病理学整体知识不断更新和提高,为临床诊断和治疗提供了大量的依据.由于肾脏活检组织标本小、切片薄,在固定、脱水、透明、浸蜡、切片及染色等方面均与常规石蜡切片有所不同,其技术要求较高.肾穿刺石蜡切片时间较长,相对制约了急性肾功能衰竭、急进性肾炎、肾移植急性排斥反应等急重症的快速诊断.     

异色瓢虫视觉系统中5-HT阳性神经元的分布

本文运用树脂石蜡（Colophony-Paraffin,CP;专利号：ZL98125709．7）组织包埋切片技术,结合免疫组织化学链酶菌抗生物素蛋白一过氧化物酶（Streptavidin-Peroxidase,SP）双染法,对异色瓢虫视觉系统中5-羟色胺（5-HT）能神经元的分布进行了初步研究。结果显示,异色瓢虫视觉系统的结构及5-HT免疫反应系统相对比较特殊。5-HT阳性神经元胞体数目较少,染色显著,并聚集成群。根据胞体定位、细胞形态及轴突走向,可大体分为5群,其中包括1群呈弱反应的光感细胞。5-HT阳性膨大纤维支配所有的视神经纤维网,并呈柱状或分层排列模式。结果表明5-HT作为经典的神经递质在昆虫的视觉信息处理过程中可能发挥重要的调节作用,且主要以远距离的广域神经调节模式为主,并在特定区域和GABA有伴随现象。此外,昆虫视觉系统中5-HT的含量还可能与其明暗适应的生理调节方式具有相关性[动物学报51（5）：912—918,2005]。     

中国人胃癌染色体17q21区域基因遗传不稳定性研究

To investigate microsatellite instability (MSI) and loss of heterozygosity (LOH) of locus D17S396, D17S579 and D17S855, and their effect on the expression of nm23H1 and BRCA1 of gastric cancer, which would provide experimental basis for clinical treatment and prognosis analysis of gastric cancer. DNA was extracted from paraffin-embedded materials. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was used to analyze MSI and LOH. Expression of nm23H, and BRCA1 was detected by Envision immuno-histochemistry and Leica-Qwin computer imaging techniques. In the forty cases of gastric cancer, the frequency of MSI, LOH and nm23H1 protein were 20.00%, 17.50% and 55.00% respectively at locus D17S396, while at locus D17S579, the frequency of MSI, LOH and BRCA1 protein were 22.50%, 15.00% and 37.50% respectively; at locus D17S855, the frequency of MSI, LOH and BRCA1 of thirty-seven cases were 18.92%, 18.92%, 37.84% respectively. In tumor node metastasis (TNM) staging, at locus D17S396, D17S579 and D17S855, MSI in stages I + II appeared more frequently than that in stages III + IV, while LOH appeared the contrary tendency. In the group of metastasis of gastric cancer, MSI had a less frequency (5.00%) than that with no metastasis (35.00%, P < 0.05) at locus D17S396, but LOH appeared more frequently (30.00%) than that with no metastasis (5.00%, P < 0.05). At locus D17S579, MSI had an increasing tendency with the degree of tumor differentiation (50.00% in high differentiation cases, 20.00% in middle differentiation cases, and 0% in low differentiation cases, P < 0.05). The frequency of nm23H1 and BRCA1 protein in stages TNM I + II was higher than that in stages TNM III + IV; and that in higher differentiation cases was higher than in poor differentiation cases. The frequency of nm23H1 protein in the group of metastasis (30.00%) was less than that with no metastasis significantly (80.00%, P<0.01). The frequency of nm23H1 protein in the group positive to MSI (87.50%) was higher than that in the group negative to MSI (46.88%, P < 0.05). However, nm23H1 protein in group positive to LOH (14.29%) was lower than that in the group negative to LOH (63.64%, P < 0.05). The frequency of BRCA1 protein in the group positive to MSI (66.67%) was more than that in the group negative to MSI (29.03%, P < 0.05). The results of experiments indicate that MSI and LOH may separately control the development of sporadic colon cancer with different pathways. MSI may be an early period molecule marker for sporadic colon cancer, enhanced expression of nm23H1 protein can effectively inhibit colon cancer metastasis and improve prognosis of sporadic colon cancer patients. By comparison, LOH mostly arises in the late period of sporadic colon cancer and endows a high aggressive and poor prognostic phenotype. nm23H1 protein could effectively restrain gastric cancer metastasis and development; and BRCA1 protein could restain tumor from becoming lower differentiation.