胃癌及癌前病变中幽门螺杆菌感染对癌基因表达的影响

目的探讨在胃癌和胃黏膜癌前病变中幽门螺杆菌(Hp)的感染及其对癌基因表达的影响。方法收集226例胃镜活检及手术切除胃标本中慢性萎缩性胃炎(CAG)、胃上皮不典型增生(GED)、肠上皮化生(IM)及肠型胃癌(GC)组织标本,采用HE和W arth in-Starry染色法,对比Hp感染与各种病变之间的关系。并通过免疫组化法检测各组标本中p53、p16和胃蛋白酶原C(PGC)的表达水平。结果Hp感染与CAG无关(P>0.05),与GED、IM和GC的发生显著相关(P<0.05)。PGC与病变恶性程度呈明显负相关(P<0.05);p53的表达与病变恶性程度呈明显正相关(P<0.05);而p16则与病变恶性程度呈明显负相关(P<0.05)。在Hp阳性的胃黏膜癌前病变组织中,p16的表达均显著低于Hp阴性组织(P<0.05);在Hp阳性的GC中,p53的表达高于阴性组织(P<0.05)。结论Hp感染是诱导胃黏膜发生癌前病变及形成GC的重要致病因素,PGC可以较敏感地指示病变恶性程度。p16基因表达的改变在GC发生早期起重要作用;p53基因表达的改变发生在GC的较晚期,它们的变化与Hp感染可能都有一定的关系。     

Immunocytochemical detection of p21 ras expression in fresh human leukaemic cells and cell lines

Summary The expression of p21 ^ras proteins was investigated by immunocytochemistry in permanent cell lines and in fresh human leukaemic cells. While high and low levels of p21 ^ras could be detected in most of the cell lines, no significant p21 ^ras immunoreactivity was noted in cells of ten human acute and chronic leukaemias. Thus, notwithstanding its possible role in the initial transformation process in human leukaemias, p21 ^ras expression appears not to be an irrevocable requirement for the maintenance of the transformed state.     

Detection ofrat gene alterations andras proteins in colorectal cancer

DNA extracted from 31 primary colorectal carcinomas was analyzed for the presence ofras gene amplification and mutations. Nine carcinomas had Ha-ras amplification and seven Ki-ras amplification. Nine carcinomas had codon 12 Ki-ras mutations. Immunohistochemical staining forras proteins revealed a normal membrane association in normal mucosa and benign polyps but an abnormal cytoplasmic distribution in carcinomas. Amplification, mutations, and immunohistochemical staining were independent of histologic differentiation, Duke's stage, or DNA ploidy status. This study demonstrates that abnormalities ofras genes are a common finding in colorectal carcinomas. They are potentially important biologic changes associated with malignancy, although they do not appear to be related to clinical behavior. Supported by The Cancer Research Campaign and the North West Regional Health Authority.     

Retroviral Sequences in Rheumatoid Arthritis Synovium

There are several relationships between retroviruses and cellular transformation, as well as retroviruses being involved in the development of autoimmune diseases. Retroviruses have been discussed as etiologic agents modulating or triggering certain pathways in the pathogenesis of rheumatoid arthritis (RA). However, none of the currently known retroviruses has been identified as specific for RA. Due to the unique properties of retroviruses, distinct experimental approaches can be used to detect retroviral activity in cells and tissues. Current research in RA using state-of-the-art molecular biology techniques includes both the search for exogenous and endogenous retroviral gene sequences in synovium of patients with RA.     

Evaluating the landscape of gene cooperativity with receptor tyrosine kinases in liver tumorigenesis using transposon-mediated mutagenesis

1. Download high-res image (166KB)
2. Download full-size image

     

Overview of the biochemical and genetic processes in malignant mesothelioma

Malignant mesothelioma (MM) is a highly aggressive form of cancer, has a long latency period, and is resistant to chemotherapy. It is extremely fatal, with a mean survival of less than one year. The development of MM is strongly correlated with exposure to asbestos and erionite, as well as to simian virus 40. Although various countries have banned the use of asbestos, MM has proven to be difficult to control and there appears to be a trend toward an increase in its incidence in the years to come. In Brazil, MM has not been widely studied from a genetic or biochemical standpoint. In addition, there have been few epidemiological studies of the disease, and the profile of its incidence has yet to be well established in the Brazilian population. The objective of this study was to review the literature regarding the processes of malignant transformation, as well as the respective mechanisms of tumorigenesis, in MM.     

复方花刺参粘多糖对髂动脉内皮剥脱家兔内膜增生的影响及机制

为了观察复方花刺参粘多糖对动脉损伤家兔内膜增生的影响及其作用机制 ,将雄性新西兰大白兔 37只随机分为正常组、模型组、花刺参组和辛伐他汀组 ,髂动脉损伤术后 6周全部家兔处死 ,取受损动脉 ,HE染色观察动脉形态学改变并图像分析测量动脉内膜、中膜厚度 ,原位杂交检测血小板源生长因子、碱性成纤维细胞生长因子和转化生长因子 β1的表达 ,免疫组织化学染色观察凋亡基因bcl 2和bax表达的改变。结果发现 ,与模型组相比 ,花刺参组和辛伐他汀组动脉内膜厚度及内膜中膜厚度比均明显减小 (P <0 .0 1) ,血小板源生长因子及转化生长因子β1的表达明显降低 (P <0 .0 5 ) ,bax表达明显升高 (P <0 .0 5 ) ,但bcl 2表达无明显差异 ;花刺参组与辛伐他汀组之间各指标均无显著差异。结果提示 ,复方花刺参粘多糖可有效减轻家兔髂动脉损伤血管内膜厚度和管腔狭窄 ,其作用机理与抑制血管平滑肌细胞增殖和促进凋亡有关。