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排序方式: 共有874条查询结果,搜索用时 234 毫秒
221.
通过对Si-1基因6,14和15号外显子区段的PCR扩增,分析了Si-1基因在116例恶性肿瘤组织、1例良性肿瘤和21例非肿瘤组织的缺失和突变.发现恶性肿瘤中有7例缺失,8例有内含子突变;良性肿瘤中没有缺失和突变;非肿瘤组织中没有缺失,1例有内含子突变.脑肿瘤的缺失率最高,达到57.1%,内含子突变率42.9%;肝癌的缺失率达15%,内含子突变率26.7%.上述结果表明,Si-1基因在脑肿瘤和肝癌组织中有较高的缺失和内含子突变,显示该基因有可能是这2种肿瘤的易感基因. 相似文献
222.
SHAO YuanZhi ZHONG WeiRong WANG FengHua HE ZhenHui XIA ZhongJun 《科学通报(英文版)》2007,52(12):1635-1641
Considering the growth of tumor cells modeled by an enzyme dynamic process under an immune surveillance, we studied in anti-tumor immunotherapy the single-variable growth dynamics of tumor cells subject to a multiplicative noise and an external therapy intervention simultaneously. The law of tumor growth of the above anti-tumor immunotherapy model was revealed through numerical simula- tions to the relevant stochastic dynamic differential equation. Two simulative parameters of therapy, i.e., therapy intensity and therapy duty-cycle, were introduced to characterize a treatment process similar to a tumor clinic therapy. There exists a critical therapy boundary which, in an expo- nent-decaying form, divides the parameter region of therapy into an invalid and a valid treatment zone, respectively. A greater critical therapy duty-cycle is necessary to achieve a valid treatment for a lower therapy intensity while the critical therapy intensity decreases accordingly with an enhancing immunity. A primary clinic observation of the patients with the typical non-hodgekin’s lymphoma was carried out, and there appears a basic agreement between clinic observations and dynamic simulations. 相似文献
223.
法律术语数据库在自然语言检索中的应用研究 总被引:1,自引:0,他引:1
毛海飞 《科技情报开发与经济》2007,17(27):220-221
介绍了术语和术语数据库,分析了术语数据库在自然语言检索中的应用机制,探讨了基于法律术语数据库的自动标引。 相似文献
224.
目的:观察乳腺肿物针吸细胞学诊断与组织病理学检查的符合率。方法:对166例乳腺肿物吸出组织,经巴氏(Papanicolaou)染色,参照分级标准及良、恶性肿瘤组织细胞的形态进行了显微镜下早期诊断。结果:166例针吸细胞学诊断与组织病理检查诊断符合率为89.76%、灵敏度84.81%、特异度94.25%。其中良性肿瘤69例,假阴性12例(12.77%);乳腺癌和高度怀疑有癌特征的97例,假阳性5例(6.94%)。结论:乳腺针吸细胞学检查在乳腺肿物的临床诊断中具有准确、可靠、安全、经济等重点意义,可以作为乳腺癌诊断的重要手段。 相似文献
225.
韩凤娟 《哈尔滨商业大学学报(自然科学版)》2002,18(1):66-68
以S180荷瘤鼠、SKOV3卵巢癌模型鼠为研究对象,进行海马生髓丸抗肿瘤的实验研究.通过对移破植瘤的抑瘤率、光、电镜技术及细胞凋亡调控基因P53、BcL-2等免疫组化的研究,表明海马生髓丸具有一定的抗肿瘤作用,可以抑制S180荷瘤鼠的肿瘤生长,明显增强SKOV3卵巢癌模型鼠DDP的杀伤肿瘤作用,对肿瘤细胞的凋亡具有明显促进作用. 相似文献
226.
MRI与CT对恶性胸膜间皮瘤的诊断价值比较 总被引:1,自引:0,他引:1
目的:探讨、比较MRI和CT在恶性胸膜间皮瘤临床诊断中的意义。方法:25例经病理组织学或细胞学证实的恶性胸膜间皮瘤患者,术前均进行了MRI和CT检查;比较分析其影像学表现特点及其临床意义。结果:MBI除了对肿瘤内钙化的显示率低于CT外,对恶性胸膜间皮瘤形态学的观察普遍优于或等于CT,尤其对叶间胸膜及横膈膜增厚的显示、肿块侵犯胸壁或膈肌以及肺门或纵隔淋巴结构的显示优于CT。恶性胸膜间皮瘤在T1WI上呈低信号或等信号,而在T2WI及增强T1WI上绝大部分呈高信号。结论:与CT比较,MRI对恶性胸膜间皮瘤的TNM分期以及治疗方案的制订更具指导意义。 相似文献
227.
Tumor metastasis is generally agreed to be the major cause of cancer death. Over the last few years, studies of new diagnosis
techniques and tumor immunotherapy have made great progress. Recent clinical studies on the occult metastases of breast, lung
and colorectal cancer all suggested that the detection of micrometastases in bone marrow is prognostically important and provides
substantial evidence of tumor dissemination. On the other hand, two kinds of the mAb-based immunotherapy have been approved
for the treatment against epithelial cancer. Monoclonal antibody (mAb) 17-1A for colorectal carcinomas and mAb herceptin for
breast cancer both have produced good curative effects. Potential therapeutics based on some antibodies with prominent antitumor
activity also has shown obvious clinical effect. These studies indicate that detection of micrometastasis in circulatory system
and immunotherapy by eliminating metastatic malignant cells suggested a new strategy against the metastatic cancer. 相似文献
228.
Pervious studies demonstrate that lats,also known as warts,is a tumor suppressor gene in Drosophila^[1,2],Mutations of lats lead to an increase in cell number and organ size in Drosophila,indicating lats may be involved in organ size control.Furthermore,the high conservation of sequence and tumor suppression functioin of lats between Drosophila and human suggests that it may be also involved in organ size control of higher animals^[3],So here we isolated the bovine homologue of Drosophila lats.Sequence analysis indicates the bovine LATS1 to be very similar to other lats proteins. 相似文献
229.
Interaction of hepatitis B virus with tumor suppressor gene p53: its significance and biological function 总被引:2,自引:0,他引:2
The mechanism of the interaction of hepatitis B virus (HBV) with tumor suppressor p53 and its role in the hepatocar-cinogenesis have been studied by PCR-directed sequencing, gel shift assays and in situ ultraviolet cross-linking assay. The biological function of the interaction of HBV with p53 gene was investigated by co-transfection of chloramphenicol acetyltransferase ( CAT) reporter gene. p53 and HBV DNA. and quantitative PCR. Among the 16 primary hepatocellular carcinoma (PHC) samples. 13 were HBV-DNA positive. 10 HBxAg positive and 9 p53 protein positive. The p53 gene point mutation was found in 5 samples, one of which had a G to T substitution located at codon 249. After analyzing the HBV genome by a computer program, a p53 response element binding sequence was found in HBV genome at upstream of enhancer I. from 1047 to 1059 nucleotides. This sequence could specifically bind to p53 protein, increase p53 protein accumulation in the PHC cells and stimulate the transactivating activity of p53 and HBV replication . The results also revealed that HBxAg could combine with p53 protein to form a complex in the cells and enhance CAT expression. Immunocytochemical staining showed that p53 protein complex was located in the cytoplasm and the process of p53 entry to nuclei was. in part, blocked. From our results, we conclude that the mutation of p53 gene at codon 249 is infrequent in HBV-associated PHC. the DNA-protein binding between HBV and p53. and the protein-protein binding between HBxAg and p53 might lead to the reduction or inactivation of p53 protein, which in turn resulting in HBV-associated hepatocarcinogenesis. 相似文献
230.
Electrochemotherapy (ECT) is a novel cancer treatment in which electric pulses (EPs) inducing cell membrane pored (eleetroporation) are used as a means of delivering antitumor drugs to the cytoplasm of cancer cells. In vitro, with scan electromicroscope (SEM) and Trypan blue staining examination, the best parameter of EPs of electroporation is studied by the S-180 cells exposed to EP with various voltages, pulses, capacitance. The best parameter of EP of electroporation is 600V/cm, 6 pulses, 10 μF. In the in vivo study, ECT is studied with the Cytoxan (CTX) injected directly into the tumor followed immediately by a local EP at the tumor site.Four parameters, which include the tumor inhibitory ratio, the curing ratio and the vas capillareof tumor, the tumor‘s histopathological characteristics are determined and compared among the ECT group, the control group, the EP-only group and the drug-only group. The results indicate that the antitumor effect of CTX is sitrnifiezntlt enhanced by electroporation. 相似文献