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1.
精细胞分离是研究雄性生殖发育的前提之一,近半个世纪以来,人们运用不断更新的生物实验技术,对被子植物精细胞开展了分离及细胞分子特征的研究。分析被子植物精细胞分离方法,总结精细胞二型性与倾向性、细胞融合方面的研究成果,并对其研究意义和前景进行讨论。  相似文献   
2.
目的探讨食管癌患者年龄、吻合位置与术后并发症发生率和死亡率的关系,以及新辅助化疗对食管癌手术切除率的影响。方法回顾性分析西安交通大学医学院第一医院肿瘤外科自1997年~2003年首诊收治、资料完整587例食管癌患者资料。结果不同年龄组手术切除率分别为91.2%、95.9%和97.7%(P>0.05);>70岁年龄组术后吻合口瘘发生率和术后死亡率均较其它组高(P<0.05)。胸膜顶部吻合口瘘发生率为16.67%,较其它位置吻合口瘘发生率明显高(颈部2.17%、弓上1.09%、弓后2.60%、弓下0),具有显著性差异(P=0.019)。III期食管癌患者行术前新辅助化疗组与未化疗组的手术切除率分别为96.92%和78.85%,具有显著差异(P<0.05),而术后吻合口瘘发生率和术后死亡率无明显差异(P=1.000)。结论术前新辅助化疗可提高食管癌手术的切除率并不增加术后并发症。年龄大并不完全是手术禁忌,高龄患者的手术应充分考虑患者的生理年龄。  相似文献   
3.
目的:探讨热休克蛋白70(HSP70)在人乳腺癌和胃癌中的表达及其意义。方法:应用免疫组织化学的方法对64例乳腺癌和55例胃癌组织中的HSP70进行检测。结果:(1)HSP70在乳腺癌和胃癌组织中的表达分别为78.13%.61.82%。(2)乳腺癌中HSP70的表达与乳腺癌的病理类型.淋巴结转移情况及年龄未发现显著差异(P〉0.05)。(3)胃癌中HSP70的表达与肿瘤浸润深度、淋巴结转移有密切关系(P〈0.05)。结论:HSP70在乳腺癌和胃癌中均呈较高水平表达.其中在胃癌中的表达与肿瘤浸润深度、恶性程度有密切关系,HSP70在乳腺癌和胃癌的发生发展中起重要作用。HSP70可能成为乳腺癌,胃癌的诊断指标之一。  相似文献   
4.
目的 :为探讨C -erbB - 2蛋白在胃癌、大肠癌和乳腺癌中表达的异同和意义。方法 :取胃癌 114例、大肠癌 10 4例和乳腺癌 10 6例 ,石蜡切片 ,SP免疫组织化学染色。结果 :C-erbB - 2在胃癌、大肠癌和乳腺癌中的阳性率分别为 71.9%、5 7.7%和 5 4 .7%。C -erbB - 2在胃癌和大肠癌中的表达与患者年龄有关 ;C -erbB - 2表达与大肠癌分化程度及乳癌恶性程度有关。结论 :C -erbB - 2高表达是大肠癌、乳癌恶性度高 ,预后不良的指标  相似文献   
5.
Objective: To determine the effective nucleotide sites of ribozymes against HCV, and obtain a highly effective, nontoxic and inexpensive antisense ribozyme specific for HCV. Methods: Two effective ribozymes, targeted to HCV 5’NC region and C region, were designed and synthesized. Eukaryotic expression vectors, pSV2-gpt. CD-SR (, containing either HCRZNC or HCRZC were constructued and transfected into MT-2 cells, which had been infected by HCV. Quantitative PCR and hydridization were used to determine the effect of inhibition of HCV by ribozymes. Results: HCRZNC and HCRZC suppressed the replication of HCV by 54.7% and 62.1%, respectively. Furthermore, when both ribozymes were cotransfected into cells, they suppressed replication by 78.8%. Conclusion: Two specific antisense ribozymes have strong inhibitory effects on the replication of HCV in cultured cells, and have better effect when used together.  相似文献   
6.
文章对水稻胚乳细胞发育过程、淀粉体和蛋白体结构特征与结实特性、养分输入胚乳细胞的途径、ATPase活性分布与水稻充实的关系、水稻强弱势粒胚乳细胞发育与其结实特性进行分析.提出进一步研究胚乳细胞发育及其超微结构与籽粒生理活性的关系,可从深入开展亚显微水平下强弱势粒背部维管束结构、ATPase的活性分布、差异表达基因对结实特性的影响等方面展开研究.  相似文献   
7.
This study evaluates the use of an open‐ended question to determine students' knowledge structure on the topic of galvanic cells. The open‐ended question was developed and administered to 163 Grade 10 students who had earlier completed a course on electrochemistry. Students' responses were marked as well as coded on the basis of the fields identified from their responses. This was then evaluated statistically to determine the collective knowledge structure of the sample of students. The knowledge structure thus mapped contains both canonical concepts and alternative conceptions (ACs). An important finding emerging from this study is that instructors need to focus student's attention on the dynamic processes involving electrons and ions during the operation of galvanic cells. In order for students to fully understand how a galvanic cell operates, they need to see the whole picture. There are three critical components that lead to students' understanding of how an oxidation–reduction reaction can generate energy and how a circuit is complete: transfer of electrons during oxidation–reduction half‐reactions, flow of electrons within metals, and migration of ions in solution. Also, we found that it is possible for students to use correct chemistry concepts in an incorrect way by establishing linkages among these in an inappropriate manner. We reiterate that apart from evaluating students' ACs, it is also important to evaluate the links between the concepts and conceptions present in students' knowledge structure so that teaching can be made more effective.  相似文献   
8.
我们利用冰冻切片和酶联(E_2—HRP,Pg—HRP)免疫组织化学方法、检测了82例大肠癌组织中的雌、孕激素受体(ER、PR),结果表明:ER阳性率为54.87%、PR阳性率为45.12%。本实验提示在大肠癌45—54%的病例属激素依赖型。文中对ER、PR的结构和作用机理进行了阐述。  相似文献   
9.
Objective: To investigate the directed transplantation of allograftic bone marrow-derived mesenchymal stem cells (MSCs) in myocardial infarcted (MI) model rabbits. Materials and Methods: Rabbits were divided into 3 groups, heart infarcted model with MSCs transplanted treatment (MSCs group, n=12), heart infarcted model with PBS injection (control group, n=20), sham operation with PBS injection (sham group, n=l 7). MSCs labelled by BrdUrd were injected into the MI area of the MSCs group. The same volume of PBS was injected into the MI area of the control group and sham group. The mortality, LVIDd, LVIDs and LVEF Of the two groups were compared 4 weeks later. Tropomyosin inhibitory component (Tn I) and BrdUrd immunohistochemistry identified the engrafted cells 4 weeks after transplantation. Result: The mortality of the MSCs group was 16.7% (2/12), and remarkably lower than the control group's mortality [35% (7/20) (P<0.05)].Among the animals that survived for 4 weeks, the LVIDd and LVIDs of the MSCs group after operation were 1.17±0.21 cm and 0.74±0.13 cm, and remarkably lower than those of the model group, which were 1.64±0.14 cm and 1.19±0.12 cm (P<0.05); the LVEF of the MSCs group after operation was 63±6%, and remarkably higher than that of the model group,which was 53±6% (P<0.05). Among the 10 cases of animals that survived for 4 weeks in the MSCs group, in 8 cases (80%),the transplanted cells survived in the non MI, MI region and its periphery, and even farther away; part of them differentiated into cardiomyocytes; in 7 cases (70%), the transplanted cells participated in the formation of blood vessel tissue in the MI region. Conclusion: Transplanted allograftic MSCs can survive and differentiate into cardiomyocytes, form the blood vessels in the MI region. MSCs transplantation could improve the heart function after MI.  相似文献   
10.
[目的]探讨抗增殖核蛋白的单克隆抗体(Ki-67)在肝细胞肝癌(HCC)中的表达情况及临床意义.[方法]采用免疫组织化学方法检测51例HCC病人术后存档的石蜡标本中Ki-67的表达情况.[结果]HCC中Ki-67阳性表达率58.8%.Ki-67表达阳性率与肿瘤大小、门脉癌栓和肿瘤分级相关,与肝硬化、病灶数目、包膜、AFP及HBsAg不相关,Ki-67阳性表达组HCC病人术后无瘤生存期均显著低于阴性表达组.[结论]Ki-67对HCC的浸润转移均起促进作用,是HCC预后的重要标志物.  相似文献   
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