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991.
Aneuploidy of mouse chromosome 8 induced by a Chinese medicinal herb, Tripterygium hypoglaucum (level) Hutch (THH) was investigated by fluorescence in situ hybridization (FISH) in vivo. Male mice were treated with THH (single i.p. injection) at doses of 120, 240 and 480 mg/kg. Colchicine (COL, 1.5 mg/kg i.p.) was used as a positive control. Bone marrow cells and epididymal sperm were collected 24 h and 22 days after treatment, respectively. Chromosome 8 aneuploidies induced by THH in bone marrow cells and sperm were determined by FISH with a biotin-16-dUTP labelled DNA probe corresponding to the centromeric region of chromosome 8. The hybridized probe was detected with avidin-FITC. The frequencies of trisomy 8 in bone marrow cells were 0.16% in the solvent control group, 0.39% in the COL-treated group and 0.33, 0.41 and 0.41% in the THH-treated groups, respectively. The frequencies of disomy 8 sperm were 0.11% in the solvent control group, 0.27% in the COL-treated group and 0.23, 0.27 and 0.27% in the THH-treated groups, respectively. The experiment showed that induced aneuploidy frequencies were higher in bone marrow cells than in sperm with COL and the two higher doses of THH (P < 0.05). All groups were significantly different from the corresponding solvent controls (P < 0.01-0.001), but there was no dose-related increase in either cell type. Considering the present results together with our previous studies, it appears that THH is a potent mammalian aneugen which may pose a genetic risk to human patients. 相似文献
992.
高压氧中毒小鼠脑微血管图像分析定量研究 总被引:3,自引:0,他引:3
本文采用计算机图像定量测量方法,对高压氧中毒后小鼠软脑膜微血管和大脑皮质毛细胞血管内皮细胞碱性磷酶活性进行了定量检测。结果表明,HBOI后小鼠软脑膜毛细血管开放数目减少,毛细血管密度降低。 相似文献
993.
为研究亚低温对大鼠脑缺血再灌注后皮质iNOS表达、NO产生及神经元凋亡的影响及探讨亚低温的神经保护机制,用大鼠短暂全脑缺血模型,采用Nissl染色观察存活神经元、免疫组化法检测iNOS、硝酸还原酶法检测NOx-水平和TUNEL染色结合电子显微镜观察检测凋亡神经元。结果显示:常温缺血组额叶皮质iNOS表达、NOx-水平增高,出现凋亡神经元;低温缺血组iNOS表达、NOx-水平明显低于常温缺血组,未检测到凋亡神经元。上述结果提示,脑缺血后iNOS来源的NO参与了神经元的凋亡过程,亚低温可减少大鼠短暂性全脑缺血后iNOS诱导的神经元凋亡。 相似文献
994.
Since the outbreak of a SARS epidemic last year, significant advances have been made on our understanding of the mechanisms of interaction between the SARS coronavirus (CoV) and the immune system. Strong humoral responses have been found in most patients following SARS-CoV infection, with high titers of neutralizing Abs present in their convalescent sera. The nucleocapsid (N) and spike (S) proteins of SARS-CoV appear to be the dominant antigens recognized by serum Abs. CD4+ T cell responses against the N protein have been observed in SARS patients and an HLA-A2-restricted cytotoxic T lymphocyte epitope in the S protein has been identified. It is likely that the immune responses induced by SARS-CoV infection could also cause pathological damage to the host, especially in the case of proinflammatory cytokines. There is also evidence suggesting that SARS-CoV might be able to directly invade cells of the immune system. Our understanding on the interaction between SARS-CoV, the immune system and local tissues is essential to future diagnosis, control and treatment of this very contagious disease. 相似文献
995.
白细胞介素4基因转移的肿瘤细胞体外生物学特性及体内致瘤性的研究 总被引:2,自引:1,他引:2
观察了白细胞介素4(IL-4)基因转移的肿瘤细胞体内致瘤性的变化。构建了含500bp的小鼠IL-4cDNA的真核表达载体BMGNeo-IL-4.用该表达载体将IL-4基因转移至小鼠B16黑色素瘤细胞,通过G418抗性筛选、有限稀释法及IL-4活性检测,获得了高分泌IL-4的黑色素瘤细胞克隆株并经Northern印迹鉴定,将其接种于小鼠皮下后观察到肿瘤生长缓慢、小鼠存活期延长,表明高分泌IL-4的细胞克隆株体内致瘤性显著下降。该结果为进一步研究肿瘤的IL-4基因治疗打下了基础。 相似文献
996.
本研究应用离体培养的兔卵巢颗粒细胞观察了IFN-a对孕酮生成的影响。细胞预培养24h后,用IFN-a(50~800U/ml)处理培养的颗粒细胞12b刺激孕酮的生成并呈剂量依赖关系。在IFN-a加入培养细胞后3、12和24h.刺激作用非常明显,但刺激作用的幅度在3和12h较大,分别为对照组的24和20倍。此外,IFN-a刺激离体兔颗粒细胞孕酮生成的作用被同时加钙螫合剂EGTA(1mmol/L)或钙通道阻断剂异搏定(ver)20和200μmol/L所抑制。本研究结果表明,IFN-a刺激离体兔卵巢颗粒细胞孕酮的生成,其作用依赖于细胞外的Ca2+浓度。 相似文献
997.
998.
单位氧耗量氧比传导,简称氧比传导(MO2-SC)是新近提出的一项综合评价机体低氧生理性适应水平高低的客观指标。本实验于低压舱内模拟高原低压性低氧条件(相当于6000m海拔高度),研究了大量气体交换系统MO2-SC的适应特征及规律。结果发现,低氧条件下,从吸入气(I)至肺泡气(A)(I→A)、A至脉动血(a)(A→a)、a至混合静脉血(v↑-)(a→v↑-)及I→v↑-间氧分压差明显减小(P〈0.0 相似文献
999.
大鼠胸腺不同区域嗜锇性细胞的结构和性质的观察 总被引:2,自引:0,他引:2
应用锇黑法、银浸法和酶组织化学法探讨了大鼠胸腺嗜锇性细胞的分布、形态结构和性质。结果显示:嗜锇性细胞主要密集分布于皮髓质交界区,形成一个致密的细胞带以及散在于皮质和髓质中。嗜银性细胞也密布于皮髓质交界区,与此处的嗜锇性细胞相一致。这些细胞呈AcP和NsE阳性反应,在皮髓质交界区形成一个强阳性反应细胞的致密带。此外,该区的细胞也具有PAS阳性反应和含有被醛复红特异性染色的颗粒。以上结果提示:大鼠胸腺 相似文献
1000.
Morphological typing of argyrophilic nucleolar organizer regions (AgNOR) in 300 caws of malignant tumors and 140 cams of benign lesions was analyzed and five morphological types of ApNOR were described in detail. In malignant tumors, the diffuse type (78%) was the most frequently seen, and in benign lesions, the nucleolar type (92.85%); the difference was thus highly significant (P < 0.001). The intranucleolar and aggregate types were not observed in benign lesions. There was no obvious difference in the proportion of the mixed type in benign and malignant lesions (P > 0.05). The relationship between grade of malignancy and morphological typing of AgNOR and its clinical significance are discussed. 相似文献