Altered establishment/clearance mechanisms during experimental micrometastasis with live and/or disabled bacterial lacZ-tagged tumor cells.

To study micrometastasis at its earliest stages, the bacterial lacZ marker gene was introduced into human EJ Ha-ras-transformed BALB/c 3T3 cells (LZEJ), followed by their intravenous injection into nude mice. Lung micrometastases were easily identified by blue staining of lacZ-tagged cells minutes/hours after injection, permitting effective evaluation of establishment/clearance mechanisms of LZEJ cells. Different treatments were used to disable LZEJ cells (fixation, irradiation, or mitomycin C) to determine modulation of these processes--although unable to divide, these cells stain for lacZ expression for days after treatment. Fixation-killed cells generated large microfoci (> 13-15 cells/focus) with well-rounded morphologies while live, irradiated, or mitomycin-treated cells generated smaller, irregularly shaped foci (3-7 cells/focus). Fixed-cell foci were cleared more slowly from lungs than the other three classes, even when prefiltered to remove large aggregates. All foci of disabled cells were eventually cleared while a basal level of live-cell foci persisted. Co-injection of fixed and live cells (or preinjection of fixed cells, followed by live cells) resulted in complete clearance of live-cell microfoci; in contrast, preinjection of live cells (then injection of fixed cells) led to survival of live-cell micrometastases. Therefore, altered deformability and/or cell surface interactions of tumor cells modulate the effectiveness of host-clearing mechanisms in the lung and in some situations these altered cells facilitate clearance of live tumor cells that are normally tumor-progressing.     

胸大肌肌皮瓣在口腔颌面部缺损修复中的应用

报道２１９例口腔颌面部肿瘤，其中良性肿瘤１８例，恶性肿瘤２０１例，在肿瘤切除后，均采用胸大肌肌皮瓣修复缺损。采用单皮岛肌皮瓣２０１例，双皮岛肌皮瓣１６例，肌皮骨瓣２例。成功２０１例，失败１８例。讨论了胸大肌皮瓣的优点及适用范围。介绍了手术设计、操作方法。分析了成功与失败的影响因素，认为正确，精细的手术技巧是成功的关键因素。     

460例胃癌纤维胃镜活检标本的病理观察

本文分析了460例胃癌胃粘膜活检资料,结果:男:女为2.36:1:51～60岁年龄组发病率最岛(37.17％);发生部位以胃窦部最多见,占46.74％;组织学分类以低分化腺癌最多,占51 52％;在伴随病变中,畅化生的检出率为21.74％,胃腺囊为35％,胃粘膜上皮异型增生为32.61％。本组材料提示,不完全性大肠型肠化生、异型胃腺囊及胃粘膜中度以上异型增生与胃癌有密切关系。     

慢性低氧大鼠肺动脉内皮素mRNA的表达及定位

目的：探讨慢性低氧大鼠肺动脉内皮素－1基因表达及分布。方法：采用生物素标记cRNA探针，对Wistar大鼠肺动脉进行原位杂交。结果：低氧1周组及低氧2周组大鼠大部分肺动脉内皮细胞ET－1mRNA表达呈阳性信号，而对照组大鼠仅极少数阳性信号（P＜0．01）；低氧1周组大鼠部分显示强阳性信号。低氧1周组及低氧2周组大鼠部分肺动脉平滑肌细胞呈现ET-1mRNA表达阳性信号，而对照组大鼠则无阳性信号表达（P＜0．01及0．05）。结论：慢性低氧对大鼠肺动脉ET－1分泌的影响是在基因转录水平进行，且主要细胞定位在肺动脉内皮细胞，此外还包括肺动脉平滑肌细胞。     

细胞凋亡抑制因子（Fas／APO-1）与抗β2-肾上腺素能受体自身抗体的关系

目的 检测并比较心肌梗死急性期不同时间点，β2自身抗体阳性组与阴性组，患者血清中Fas／APO-1水平差异，了解β2自身抗体对Fas／APO-1的影响。方法 41例急性心肌梗死患者，分别于发病24h、7天、2～4周时取血，采用ELISA的方法，检测血清中β2自身抗体的阳性率以及Fas／APO-1的水平；另外取34位性别、年龄匹配的健康人的血同法检测Fas／APO-1作为对照。结果心肌梗死急性期Fas／APO-1的水平均高于对照组（P〈0．05），以梗死后24hFas／APO-1的水平为最高；心肌梗死急性期不同时间点，β2自身抗体阳性组Fas／APO-1的水平均高于阴性组，但两组的结果差异无显著性（P〉0．05）。结论 血清Fas／APO-1水平可以在一定程度上反映心肌细胞凋亡的变化趋势，β2自身抗体对Fas／APO-1的确切影响，有待更大规模的实验来证实。     

胞嘧啶脱氨酶的原核表达和多克隆抗体的制备

目的：在原核系统中表达并纯化大肠杆菌胞嘧啶脱氨酶（cytosine deaminase,CD)，制备鼠抗大肠杆菌CD多克隆抗体，方法：亚克隆CD基因到原核表达载体pMAL-c2和pBV222中，并转化入大肠杆菌DH5α内，诱导表达并纯化MBP-CD和6his-CD融合蛋白，用纯化的MBP-CD融合蛋白免疫小鼠制备多克隆抗体。结果：通过重组质粒的酶切筛选出重组阳性克隆，成功地表达和纯化出MBP-CD和6his-CD融合蛋白，用纯化的MBP-CD成功制备了鼠抗CD多克隆抗体，并用6his-CD和GST-CD重组蛋白进行Western印迹分析，证实了抗体的正确性，结论：应用多克隆抗体可以检测体内外CD基因的表达，为临床前和临床上深入开展CD基因的生物治疗研究提供重要的实验材料。