γ射线对白血病细胞株K562中MMP-2表达的影响及牛磺酸的防护作用

目的：探讨γ射线对白血病细胞中MMP－2表达的影响，以及从细胞水平初步探讨牛磺酸对肿瘤细胞受辐照后MMP－2表达的抑制作用。方法：^60Coγ射线15Gy照射白血病细胞K562作为阳性对照组，不照射的作为阴性对照组（1－不加药，2－加药200mg/L)，另设三组实验组（照射，加药量分别为50mg/L、100mg/L、200mg/L），照后12h收集，细胞经处理后采用Western-blotting技术分析各组细胞MMP－2的表达水平。结果：15Gy照射剂量阳性对照组细胞MMP－2表达量明显增加，阴性对照组1中MMP－2表达量较少，实验组细胞MMP－2表达量随剂量增加而依次减少，其中200mg/L组与阴性对照组1细胞MMP－2表达量基本一致。结论：15Gy^60Coγ射线照射促进白血病细胞K562中MMP－2表达，电离辐射可引起肿瘤细胞的进一步侵袭和转移；加不同剂量牛磺酸后对MMP－2表达有抑制作用，且与剂量呈相关性，实现生物防治的作用。     

创造性思维的培养与任务型口语教学

1 语言创造性的提出 　　心智主义学派乔姆斯基在批评行为主义观点时指出,如果语言可以通过不断刺激、反复模仿习得的话,动物也可以学会说话.……     

中国南方四省区流行的HIV-1 CRF01_AE病毒株基因特征研究

Objective To analyze the genetic characteristics of HIV-1 CRF01_AE strains prevailing in. the four provinces of southern China. Methods Plasma samples were collected from the newly diagnosed HIV-1 individuals reported in 2006 in Guangdong, Guangxi, Jiangxi and Hunan province. The gag and env gene fragments were amplified from RNA template extracted from plasma using RT and nested PCR methods. CRF01_AE sequences were analyzed by phylogcnetie methods and characterized by calculating the genetic distance and Entropy analysis. Results Two main epidemic clusters were found to exist in the CRF01 AE strains from 210 HIV-1 CRF01 AE infected individuals collected in the 4 provinces, southern China. It was found that no international reference strain was closely correlated with cluster Ⅰ , which including 123 samples. The strains in cluster Ⅱ, consisting 57 cases of samples, were closely related with the strains identified in Vietnam. Genetic distance analysis of gag and env genes showed that the diversity of cluster Ⅰ was obviously less than that of cluster Ⅱ. Data on nucleotide polymorphism showed that nucleotides compositions of 42 sites in gag and 40 sites in env wer esignificantly different between the two clusters. When compared with cluster Ⅱ , the polymorphism decreased at 61 nucleotide sites but increased at 21 sites in cluster Ⅰ. Conclusion This was the first report describing that two main epidemic clusters were existed in CRF01_AE strains prevailing in the 4 provinces, Southern China. The vires in cluster Ⅰ was the dominant strain in this region, with shorter period of circulation and higher proportion seen in the HIV-infected population, which might belong to CRF01_AE strain with certain features facilitating the spread of the virus. The virus in cluster Ⅱ was highly homology with the CRF01_AE strains from Vietnam, and seemed to have had several events of epidemics in populations in border regions of China and Vietnam.     

β射线对NIH3T3成纤维细胞细胞周期的影响及牛磺酸的干预作用

目的：观察β射线对NIH3T3成纤维细胞周期的影响,探讨β放射损伤的机制及牛磺酸（taurine）的辐射防护作用。方法：以不同剂量的高能电子射线模拟β射线照射NIH3T3细胞,加药组分别为（50mg／L、100mg／L、200mg／L）选择15Gy照射剂量,采用流式细胞术检测各组细胞的细胞周期率。结果：β辐射后细胞发生G2期阻滞,且与照射剂量呈正相关（P≤0．01）。在0-15Gy剂量范围内,β辐照12h后未观察到细胞发生凋亡。加入牛磺酸后,G2期受阻现象得到缓和,G2／M期百分率与药物剂量呈负相关（P≤0．01）。结论：β辐射后NIH3T3细胞属于G2期延迟细胞,牛磺酸可通过一定机制使受损的细胞不能通过G1期,从而有助于加强对细胞受损DNA的修复,起到辐射防护的作用。     

γ射线对白血病细胞K562 ppGalNAcT2 Mrna表达的影响及中药多糖的防护作用

目的 探讨γ射线对白血病细胞株K562中多肽:N-乙酰氨基半乳糖转移酶2(ppGalNAcT2,E.C2.4.1.41)基因mR-NA表达的影响,并探讨中药多糖对此种影响的防护作用。方法 以不同剂量的~(60)COγ射线照射K562细胞,并设加中药多糖实验组,观察不同剂量(5Gy、10Gy、15Gy)γ射线对K562细胞ppGalNAcT2 mRNA表达影响,及加入不同剂量中药(50mg/L,100mg/L,200mg/L)后对10Gy照射K562细胞组中T2 mRNA表达的防护作用。以RT-PCR法检测ppGalNAcT2 mRNA的表达差异变化。结果 γ射线照射K562细胞后ppGalNAcT2 mRNA表达明显减少,且与剂量呈负相关,而中药多糖则可对抗此种作用,使加中药多糖组细胞在照射后ppGalNAcT2 mRNA表达水平维持在正常细胞水平。结论 5～15Gyγ射线照射抑制白血病细胞ppGal-NAcT2 mPNA表达,可能与肿瘤细胞受照后分化抑制有关,而中药多糖明显对抗此种抑制作用。     

β照射对NIH3T3细胞中基质金属蛋白酶和糖基转移酶表达的影响及牛磺酸的干预作用

目的观察β射线对NIH3T3成纤维细胞中基质金属蛋白酶2（MMP2）和N-乙酰氨基半乳糖转移酶2（ppGalNAcT2，E．C2．4．1．41）基因mRNA表达的影响，并探讨牛磺酸对β辐射损伤的防护作用。方法以不同剂量的高能电子射线模拟β射线照射NIH3T3细胞，另外在15Gy照射组中提前12h加入不同浓度的牛磺酸（Tau），照后12h收集各组细胞，采用lit—PCR法检测MMP2、ppGalNAcT2在mRNA水平的表达差异。结果β射线照射NIH3T3细胞后MMP2的mRNA表达量增加，且与照射剂量呈正相关，ppGalNAcT2的变化情况正好相反，加入牛磺酸后可以起干预作用。结论5—15Gyβ射线照射对NIH3T3细胞中ppGalNAcT2在mRNA水平的表达有抑制作用，提示ppGalNAcT2可能与细胞的癌变等过程有关，牛磺酸能抑制MMP2的表达，同时促进ppGalNAcT2的表达，因而具有辐射防护作用。     

中国南方四省区流行的HIV-1 CRF01_AE病毒株基因特征研究

目的 分析中周南方四省区HIV-1感染者中流行CRF01 AE病毒株的遗传特征.方法 从广东、广西、江西和湖南省(自治区)2006年新报告HIV-1感染者的血浆样本中提取病毒RNA,用反转录/巢式PCR方法扩增gag和env基因片段,对获得的CRF01 AE病毒株核酸序列进行系统进化分析,并通过计算基因距离和Entropy核苷酸多态性差异方法分析毒株的遗传特征.结果 从210例CRF01_AE病毒株感染者中,发现四省区流行的CRF01 AE病毒株存在2个主要的流行簇.流行簇Ⅰ共有123例样本,未发现与之直接相关的国际参考毒株.流行簇Ⅱ共有57例样本,与越南CRF01 AE病毒株关系密切,且存在不同时间样本的混杂.gag和env基因遗传距离分析结果表明,流行簇Ⅰ内基因遗传多样性均明显小于流行簇Ⅱ;核苷酸多态性分析结果显示,在gag基因片段42个位点核苷酸组成具有显著差异,env基因片段40个位点核苷酸组成存在显著差异;流行簇Ⅰ相对于流行簇Ⅱ多态性减少的位点上有61个,多态性增加的位点有21个.结论 在中国南方四省区流行的CRF01 AE病毒株中首次观察到2个独立的流行簇.流行簇Ⅰ病毒株为该地区最主要的CRF01 AE病毒株,其流行时间相对较短,在人群中所占比例较多,可能是病毒在流行过程中形成的具有传播优势的病毒株.流行簇Ⅱ病毒与来自于越南的CRF01 AE病毒株有较高同源性,且存在与越南病毒株间的多次传播.     

茯苓多糖对受照射肿瘤细胞自由基的影响

目的：观察茯苓多糖对受照射的肿瘤细胞及细胞培养上清液自由基相关指标的影响。方法：加不同剂量茯苓多糖的K562白血病细胞在^60Coγ射线15Gy照射后，立即收集上清液和细胞样本检测自由基的变化。结果：受照后细胞培养上清液中活性氧(ROS)含量和丙二醛(MDA)含量有明显的升高，加药后有所降低但仍高于未照射组(P≤0．05)，超氧化物歧化酶(SOD)浓度在受照射及加入多糖后无明显变化规律；细胞中活性氧含量及MDA在受照射后增加，加入茯苓多糖后活性氧含量仍继续升高，而MDA有所降低但仍明显高于未照射组，SOD活性在受照射后有所下降，加药后SOD活性有所升高但仍低于未照射对照组(P≤0．05)。结论：茯苓多糖对γ射线照射引起肿瘤细胞中自由基活性的增高无显著影响，由此推测茯苓多糖对正常细胞辐射防护作用的同时基本不会影响放疗的效果。     

中国南方四省区流行的HIV-1 CRF01_AE病毒株基因特征研究

Objective To analyze the genetic characteristics of HIV-1 CRF01_AE strains prevailing in. the four provinces of southern China. Methods Plasma samples were collected from the newly diagnosed HIV-1 individuals reported in 2006 in Guangdong, Guangxi, Jiangxi and Hunan province. The gag and env gene fragments were amplified from RNA template extracted from plasma using RT and nested PCR methods. CRF01_AE sequences were analyzed by phylogcnetie methods and characterized by calculating the genetic distance and Entropy analysis. Results Two main epidemic clusters were found to exist in the CRF01 AE strains from 210 HIV-1 CRF01 AE infected individuals collected in the 4 provinces, southern China. It was found that no international reference strain was closely correlated with cluster Ⅰ , which including 123 samples. The strains in cluster Ⅱ, consisting 57 cases of samples, were closely related with the strains identified in Vietnam. Genetic distance analysis of gag and env genes showed that the diversity of cluster Ⅰ was obviously less than that of cluster Ⅱ. Data on nucleotide polymorphism showed that nucleotides compositions of 42 sites in gag and 40 sites in env wer esignificantly different between the two clusters. When compared with cluster Ⅱ , the polymorphism decreased at 61 nucleotide sites but increased at 21 sites in cluster Ⅰ. Conclusion This was the first report describing that two main epidemic clusters were existed in CRF01_AE strains prevailing in the 4 provinces, Southern China. The vires in cluster Ⅰ was the dominant strain in this region, with shorter period of circulation and higher proportion seen in the HIV-infected population, which might belong to CRF01_AE strain with certain features facilitating the spread of the virus. The virus in cluster Ⅱ was highly homology with the CRF01_AE strains from Vietnam, and seemed to have had several events of epidemics in populations in border regions of China and Vietnam.     

中国南方四省区流行的HIV-1 CRF01_AE病毒株基因特征研究

Objective To analyze the genetic characteristics of HIV-1 CRF01_AE strains prevailing in. the four provinces of southern China. Methods Plasma samples were collected from the newly diagnosed HIV-1 individuals reported in 2006 in Guangdong, Guangxi, Jiangxi and Hunan province. The gag and env gene fragments were amplified from RNA template extracted from plasma using RT and nested PCR methods. CRF01_AE sequences were analyzed by phylogcnetie methods and characterized by calculating the genetic distance and Entropy analysis. Results Two main epidemic clusters were found to exist in the CRF01 AE strains from 210 HIV-1 CRF01 AE infected individuals collected in the 4 provinces, southern China. It was found that no international reference strain was closely correlated with cluster Ⅰ , which including 123 samples. The strains in cluster Ⅱ, consisting 57 cases of samples, were closely related with the strains identified in Vietnam. Genetic distance analysis of gag and env genes showed that the diversity of cluster Ⅰ was obviously less than that of cluster Ⅱ. Data on nucleotide polymorphism showed that nucleotides compositions of 42 sites in gag and 40 sites in env wer esignificantly different between the two clusters. When compared with cluster Ⅱ , the polymorphism decreased at 61 nucleotide sites but increased at 21 sites in cluster Ⅰ. Conclusion This was the first report describing that two main epidemic clusters were existed in CRF01_AE strains prevailing in the 4 provinces, Southern China. The vires in cluster Ⅰ was the dominant strain in this region, with shorter period of circulation and higher proportion seen in the HIV-infected population, which might belong to CRF01_AE strain with certain features facilitating the spread of the virus. The virus in cluster Ⅱ was highly homology with the CRF01_AE strains from Vietnam, and seemed to have had several events of epidemics in populations in border regions of China and Vietnam.