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991.
Interferons (IFNs) exert antitumor effects in several human malignancies, but their mechanism of action is unclear. There is a great variability in sensitivity to IFN treatment depending on both tumor type and the individual patient. The reason for this variable sensitivity is not known. The fact that several IFN-induced anticellular effects are exerted through modulation of proto-oncogenes and tumor suppressor genes may indicate that the malignant genotype may be decisive in the cell's sensitivity to IFN. To determine if a deregulated oncogene could alter the cellular response to IFN, a mouse lymphoma cell line (J3D) was stably transfected with the viral human papillomavirus-16 (HPV-16) E7 oncogene. The E7-transfected cells and their respective mock-transfected sister clones were treated with IFN-alpha and examined for possible IFN-induced anticellular effects. We found that the E7-transfected clones were greatly sensitized to IFN-alpha-induced apoptosis compared with their mock-transfected counterparts. Induction of apoptosis in the transfected cells correlated with the ability of IFN to activate parts of the proapoptotic machinery specifically in these cells, including activation of caspases and the proapoptotic protein Bak. In summary, our data suggest that transfection of malignant cells with the E7 oncogene can sensitize them to IFN-alpha-induced apoptosis. This demonstrates that an oncogenic event may alter the cellular sensitivity to IFN and might also have implications for treatment of HPV-related diseases with IFN.  相似文献   
992.
本文通过对17483例甲状腺肿大中五种甲状腺病病例的收集、分析、整理、统计与提炼,确定了诊断原则,建立了知识库、病例库和正反双向混合推理机制,完成了用Turbo-Prolog语言编制。采用适用于表示医学产生式知识表示方法所开发的专家诊断与咨询系统,为教学、临床工作及家庭保健提供了有价值的软件。经临床病例验证,该软件准确、可靠、有很强的实用价值,对人工智能的研究、临床及教学的现代化,提高人们的保健水  相似文献   
993.
基于统计参数图的脑功能磁共振成像数据处理方法   总被引:1,自引:0,他引:1  
介绍了基于统计参数图的脑功能磁共振成像数据处理方法。脑功能磁共振成像由于其高的时间、空间分辨率、无创性等特点而得到广泛的应用。使用统计参数图进行脑功能成像的数据处理过程主要分为:原始数据的读取、图像预处理、统计分析和统计推论。图像预处理包括运动伪影的消除、图像标准化、图像空间平滑;统计分析包括广义线性模型的建立;统计推论包括T检验等。重点介绍了各个过程所使用的传统的处理方法和最新的处理方法。  相似文献   
994.
Exact BPF and FBP algorithms for nonstandard saddle curves   总被引:1,自引:0,他引:1  
Yu H  Zhao S  Ye Y  Wang G 《Medical physics》2005,32(11):3305-3312
A hot topic in cone-beam CT research is exact cone-beam reconstruction from a general scanning trajectory. Particularly, a nonstandard saddle curve attracts attention, as this construct allows the continuous periodic scanning of a volume-of-interest (VOI). Here we evaluate two algorithms for reconstruction from data collected along a nonstandard saddle curve, which are in the filtered backprojection (FBP) and backprojection filtration (BPF) formats, respectively. Both the algorithms are implemented in a chord-based coordinate system. Then, a rebinning procedure is utilized to transform the reconstructed results into the natural coordinate system. The simulation results demonstrate that the FBP algorithm produces better image quality than the BPF algorithm, while both the algorithms exhibit similar noise characteristics.  相似文献   
995.
高山红景天多糖对小鼠抗柯萨奇B5病毒感染能力的研究   总被引:11,自引:0,他引:11  
对感染柯萨奇B5病毒(CVB)小鼠模型研究结果表明,高山红景天多糖对发病小鼠心肌功能改善和免疫功能提高均具有明显的促进作用。增强了小鼠抗CVB5感染的能力,并对由CBV感染性疾病也有一定的防治作用。  相似文献   
996.
应用核酸分子杂交技术检测心肌炎组织中的肠道病毒RNA   总被引:4,自引:0,他引:4  
沈茜  汪美先 《中华病理学杂志》1994,23(2):79-81,T014
用生物素标记pCBIII/35和pCBIII/51肠道病毒属特异性探针,对45心肌炎和心肮病尸检或心肌活检心脏组织进行原位杂交,结果显示:12例(26.6%)存在肠道病毒RNA。柯萨基B3病毒型特异性探针pCBIII/29进一步杂交表明,12例经证实存在肠道病毒RNA的心肌组织中5例(41.7%)出现阳性杂交信号。阳性杂信号主要位于单个或多个心肌细胞的胞浆和心肌的间质组织,偶见竽心肌小血管内皮细胞  相似文献   
997.
BACKGROUND: Few epidemiological studies have examined the temporal relationship between chronic pain and depression using longitudinal data. In the present study, we examined major depression as both an antecedent risk factor and consequence of chronic back pain (CBP) in the general population. METHOD: Data on 9909 pain-free individuals 15 years and older with no history of back problems were drawn from cycle 1 of the National Population Health Survey and followed up 24 months later. Major depression was assessed using a structured diagnostic interview. RESULTS: At cycle 2, the rate of new cases of CBP in persons who were depressed at cycle 1 was 3.6% compared to 1.1% in non-depressed persons. Compared to pain-free individuals, new cases of CBP were more likely to perceive their health status as poor or fair at cycle 1, were less likely to be working, reported more chronic health problems, and sustained a back or neck injury in the preceding 12 months. After controlling for other factors, pain-free individuals diagnosed as major depressed at cycle 1 were almost three times more likely (OR 2.9, 95% CI 1.2-7.0) to develop CBP at cycle 2. CONCLUSIONS: Consistent with other longitudinal studies major depression increases the risk of developing future chronic pain. The causal mechanism linking these conditions is unknown however depression may represent a modifiable risk factor in the development of CBP.  相似文献   
998.
Electron microscopy has been the ‘gold standard’ of spatial resolution for studying the structure of the cell nucleus. Electron spectroscopic imaging (ESI) offers advantages over conventional transmission electron microscopy by eliminating the need for heavy-atom contrast agents. ESI also provides mass-dependent and element-specific information at high resolution, permitting the distinguishing of structures that are primarily composed of protein, DNA, or RNA. The technique can be applied to understand the structural consequences of epigenetic modifications, such as modified histones, on chromatin fiber morphology. ESI can also be applied to elucidate the multifunctional behavior of subnuclear ‘organelles’ such as the nucleolus and promyelocytic leukemia nuclear bodies. The authors dedicate this paper to the memory of Ying Ren (1961–2007). We all benefited from knowing her. Our research advanced through the technical creativity she provided.  相似文献   
999.
1000.
本研究从新西兰家兔腹腔渗出中性粒细胞溶酶体内提取酸溶性组分,经制备性AU-PAGE获得纯化的防御素(NP1和NP2),SDS-PAGE测定分子量为3kd左右。以HL-60细胞作靶细胞,当NP1或NP2在100μg/ml浓度时,可杀死60%以上的HL-60细胞。NP1(260μg/ml)还可直接灭活单纯疱疹病毒I型和乙型流感病毒,分别使病毒感染滴度降度98.2%和90%。本研究结果提示,中性粒细胞可  相似文献   
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