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81.
经用P~(32)每毫升25量μci的剂量标记松毛虫赤眼蜂,室内测定P~(32)放射性强度:50头成蜂为466~642cpm,20粒柞蚕卵为109—117cpm。P~(32)标记对成蜂寿命、繁殖力、性比均无不良影响。苹果园P~(32)标记放蜂表明:苹果小卷叶蛾的卵块寄生率达96%,即粒寄生率93.09%。在寄生卵块中有73.91%的卵块测出P~(32),平均每块的放射性强度为14.34cpm,说明是人工释放的效果。有26.09%的寄生卵块未测出P~(32)或很弱,此为自然赤眼蜂所寄生。 相似文献
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83.
在系统鉴定、药敏试验和血甭型鉴定的基础上,对52株致病性大肠杆菌和4株标准血清型大肠杆菌进行了质粒DNA分析,结果表明,菌株的质粒得率为100%,来源相同的菌株具有相同或相似的质粒图谱,来源不同的菌株具有不同的质粒图谱,质粒DNA分析为四川规模化猪场致病性E.coli的分子流行病学调查提供了科学依据。质粒图谱与血清型及耐药谱之间无明显关系。 相似文献
84.
进行了安普霉素耐药大肠杆菌耐药表型的研究.采用常规方法和生化鉴定管对有过安普霉素用药史的鸡场分离的鸡源病原性大肠杆菌进行鉴定,并用试管二倍稀释法测定其最低抑菌浓度(MIC),筛选出鸡源安普霉素耐药大肠杆菌;采用药敏纸片法研究了这些耐药菌对安普霉素等14种抗菌药物的敏感性.共筛选出7株对安普霉素耐药的鸡源性大肠杆菌,这些耐药菌株全部对安普霉素、妥布霉素、奈啶酸、多西环素和阿莫西林耐药;大部分对庆大霉素、链霉素、卡那霉素、壮观霉素也呈现耐药.对新霉素的耐药较低,对阿米卡星高度敏感.部分交叉耐药现象的存在揭示对安普霉素等氨基糖苷类药物产生耐药性的菌株,其他抗生素也可能对它们失去疗效. 相似文献
85.
免疫注射过程中出现疫苗过敏反应及处理 总被引:1,自引:0,他引:1
1过敏反应发生的机理 过敏反应属于一种变态反应.主要是因抗原、抗体相互作用而引起。各种疫苗中均含有抗原物质.它可刺激机体产生IgE。IgE是一种亲细胞性的过敏性抗体.由于它的存在可使机体处于致敏状态.处于这一状态的动物.如果再次接触致敏原时可使致敏的同种组织细胞产生变态反应.机体内可迅速释放出生物活性物质,如乙酰胆碱、5-羟色胺、组胺、前列腺素、心抑制因子等。 相似文献
86.
Effects of homocysteine on number and activity of endothelial progenitor cells from peripheral blood
WANG Xing-xiang SHANG Yun-peng ZHU Jun-hui CHEN Jun-zhu ZHU Jian-hua TAO Qian-min GUO Xiao-gang WANG Zhan-kun ZHANG Li 《园艺学报》2005,21(7):1274-1278
AIM: To investigate whether homocysteine (Hcy) has influences on endothelial progenitor cell (EPCs) number and activity from peripheral blood. METHODS: Total mononuclear cells (MNCs) were plated on fibronectin-coated culture dishes and cultured for 7 days, and then attached cells were stimulated with Hcy or vehicle control for 6 h, 12 h, 24 h and 48 h. The adhesion, proliferation, migration and in vitro vasculogenesis activity of EPCs were assayed, respectively. RESULTS: Incubation of isolated human MNCs with Hcy dose and time-dependently decreased the number of EPCs with maximum at 200 μmol/L for 24 hours (35.7±6.7 vs 62.5±10.6, P<0.01). In addition, Hcy impaired EPC proliferative (0.531±0.061 vs 0.328±0.055, P<0.05), migratory (26.3±6.4 vs 6.4±3.7, P<0.01), adhesive (33.1±8.1 vs 17.4±7.5, P<0.01) and vasculogenesis capacity (25.4±9.1 vs 10.4±4.7, P<0.01) in a dose and time-dependent manner. CONCLUSION: It is suggested that Hcy may result in the reduction of EPCs and decrease EPC functional activity. 相似文献
87.
AIM: To down-regulate expression of c-myc through antisense therapy and to investigate its effect on the sensitivity of osteosarcoma MG-63 cells to cisplatin-induced apoptosis. METHODS: The recombinant adenovirus (Ad-Asc-myc) encoding antisense c-myc fragment was constructed and transfected into osteosarcoma MG-63 cells in vitro in order to down-regulate the expression of c-myc, and the change in the sensitivity to cisplatin-induced apoptosis was observed. MTT, Western blot, RT-PCR, flow cytometry (FCM) and electron microscope were used to evaluate tumor cell proliferation in vitro, genes expression related to apoptosis regulation and effects on the sensitivity of osteosarcoma MG-63 cells to cisplatin-induced apoptosis. RESULTS: Ad-Asc-myc down-regulated the expression of c-myc protein after transfected MG-63 cells for 48 h, combined with the treatment of 2.0 mg/L cisplatin for 2 h inhibited tumor cell proliferation in vitro by 38.0%. RT-PCR revealed that Ad-Asc-myc down-regulated the expression of Bcl-2 and up-regulated the expression of Bax. No appreciable change was observed in the expression of E2F-1. FCM showed that Ad-Asc-myc induced apoptosis in intransfected cells, and rendered it more sensitive to cisplatin. CONCLUSION: Antisense c-myc is able per se to induce apoptosis and sensitize osteosarcoma cells to cisplatin-induced apoptosis. 相似文献
88.
AIM: In this study, we investigated the anticancer effect and mechanisms of manumycin on pancreatic cancer cell line-Panc-1 and the role of p38MAPK pathway in apoptosis. METHODS: The test of anticancer effect was performed by MTT assay. Apoptosis was induced in the cells by manumycin and then treated with SB203580, a specific p38MAPK inhibitor. A quantitative caspase-3 activity assay kit was used in this experiment. RESULTS: Manumycin (6 μmol/L, 18 μmol/L, 54 μmol/L) significantly inhibited cell growth of pancreatic cancer cell line Panc-1. The inhibition rates 24 h after treatment with 6 μmol/L, 18 μmol/L and 54 μmol/L manumycin were 8.9%, 21.9% and 67.0%, respectively. Compared with the control group, the survival levels of the last two groups were of significant statistical difference (P<0.01). The anticancer effects also showed dosage-effect relationship, the value of IC50 24 h after treatment was 34.7 μmol/L. In addition, this reagent simultaneously activated caspase-3 protein, which was partly blocked by p38MAPK specific inhibitor, SB203580. CONCLUSION: Manumycin exerted anticancer effect on Panc-1 cell line via inducing cell apoptosis, which was partly regulated by p38MAPK. 相似文献
89.
西北干旱区水资源利用与生态环境重建研究 总被引:39,自引:32,他引:39
西北干旱地区是我国西部大开发战略的重点建设区域之一。但是长期以来,由于气候干旱以及在市场经济利益驱动下所形成的人类对水产 过度开发利用,导致了一系列阻碍区域经济发展的严重生态环境问题。水资源的合理利用是干旱区振兴流域经济的主要保证,也是促使生态经济系统向良性方向发展的关键因素。本文从分析西北干旱区内陆河流域水资源系统特征、开发利用现状以及主要的水环境问题出发,得出干旱区生态恢复与重建必须以水资源的合理利用为核心的结论,同时提出了干旱区水资源利用优化途径与生态重建的基本对策。 相似文献
90.