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31.
AIM:To study the changes of K+ channels of outer hair cells in guinea pig cochlea with streptomycin ototoxicity. METHODS:Auditory brainstem responses (ABR) and whole-cell patch clamp techniques were used.RESULTS:(1) The body weight of guinea pigs with streptomycin ototoxicity decreased significantly; (2) The ABR threshold markedly increased in streptomycin group (Ⅱ,Ⅲ);(3)The number of dissociated outer hair cells of guinea pigs (Ⅱ,Ⅲ) was lower than that of control (Ⅰ); (4) Streptomycin decreased the Ca2+-sensitive K+ currents and delayed outward K+ currents distinctly; (5) There was no significant difference of K+ currents between Ⅰ and Ⅱ/Ⅲ. CONCLUSION:These results suggest that the inhibition of K+ channels is the basis of streptomycin ototoxicity, but not the direct reason for cell death.  相似文献   
32.
AIM:To establish rat chronic obstructive pulmonary disease(COPD) models by passive cigarette smoking plus intratracheal instillation of lipopolysacchride(LPS) or passive cigarette smoking only, which would be similar to the pathogenesis of human COPD. METHODS:48 Wistar rats were randomly divided into 4 groups.(1) Healthy control I group(n=12), rats were bred 4 weeks;healthy control II group(n=12), rats were bred for 3months. (2) Model group I (n=12), 200μg lipopolysaccharide(LPS) was instilled intratracheally once for every two weeks and the rats were exposured to 5% of cigarette smoke, 0.5 h/d for 4 weeks.(3) Model group II(n=12),rats were exposed to 5% of cigarette smoke, 0.5 h/d for 3 months. The pathologic changes of airways and lung tissues, pulmonary function and blood gas analysis were determined. The airway wall lymphocytes and alveolar macrophages were counted. The cross areas of epithelial layer, smooth muscle layer and lamina propria of bronchi were measured. The hydroxyproline of lung tissue homogenates was determined by biochemistry method.RESULTS:The pathologic changes of airways and lung tissue of two models were similar to but milder than those of COPD patients(biopsy data). The collagen deposition and the cross areas of epithelial layer and smooth muscle layer in airway walls of two model groups were significantly increased than those of control groups(P<0.01,P<0.05).FEV0.3/FVC% of two model groups, PaO2 and SaO2 of model I group were significantly decreased, while Ri and Re in model I group were significantly increased than that of control I group(P<0.05). The PaCO2 and the counts of lymphocytes and alveolar macrophages of both model groups were significantly increased than those of the control groups (P<0.01). Lots of alveolar macrophages had phagocyted smoke granules. The amounts of hydroxyproline of two model groups were significantly increased than those of control group((P<0.05) and were negatively related to the FEV0.3/FVC%, respectively (P<0.01,P<0.01) and positively related to airway resistance of model I group(P<0.01). CONCLUSIONS:COPD rat models were successfully established by passive cigarette smoking plus intratracheal instillation of LPS and cigarette smoking only. The pathologic changes were similar but milder than those of COPD patients. The airway obstruction of model I group was more severe than that of model II group, but they have no significant difference.  相似文献   
33.
AIM: To investigate the effects of platelet-derived growth factor on DNA and collagen protein synthesis in human vascular fibroblasts. METHODS: In the present experiment, the human vascular fibroblasts were cultured and effects of platelet-derived growth factor-BB on DNA and collagen protein synthesis in human vascular fibroblasts were observed by using [3H]-TdR incorporation and [3H]-proline incorporation in vitro. RESULTS: Platelet-derived growth factor-BB significantly promoted NDA synthesis and collagen protein synthesis of quiescent human vascular fibroblasts, with a maximal response at a concentration of 30μg·L-1at 24 h and 36 h, respectively. CONCLUSION: Platelet-derived growth factor-BB promotes DNA and collagen protein synthesis in cultured human vascular fibroblasts.  相似文献   
34.
施氮量对棉田主要害虫种群动态的影响   总被引:5,自引:0,他引:5  
通过不同施氮肥量对棉田主要害虫种群动态影响的研究结果表明,在低、中、高3种施氮肥水平处理条件下,随着氮肥量的增加,棉田棉铃虫落卵量增加,棉苗蚜、棉叶螨种群数量减少,发生为害减轻,但棉伏蚜种群数量增加。中等施氮肥条件下,第二、三代棉铃虫幼虫数量高于低和高施氮肥处理,对棉铃虫幼虫的生长发育和存活较为有利。  相似文献   
35.
核桃树体内酚类物质含量的变化   总被引:12,自引:1,他引:12  
通过对核桃酚类物质含量变化研究,结果表明,核桃枝、芽、叶中均有酚类物质存在,其平均含量范围为29.5~118.6 mg/g DW。核桃酚类物质分布随器官组织和季节的不同而有差异,即:枝条初皮部>叶片>芽体>枝条木质部;一年生韧皮部和芽体中酚类物质含量均于休眠达到高峰。不同核桃品种间酚类物质含量存在差异性,即:光皮绵核桃>白水核桃>辽核1号>中林5号。  相似文献   
36.
应用Kromasil-C18色谱柱(250 mm×4.6 mm,5 μm),WatersTM480型可调波长紫外检测器,0.01M磷酸钾(pH=7):乙腈(3:1)为流动相,检测波长265 nm,含量测定采用标准曲线法,建立了RP-HPLC法检测绵羊尿中克洛素隆含量的方法.方法有效性评价结果表明,尿药含量在0.01~5.0μg/ml及5.0~30.0μg/ml范围呈良好线形关系(r=0.9993、0.9995),方法平均回收率99.32%,日内、日间变异系数分别为3.91%、6.28%.尿药最低检测限0.005μg/ml.试验绵羊以7 mg/kg单剂量经静脉、肌肉及口服三种途径给药后,尿中药物浓度分析表明,克洛素隆经体内处理后主要经肾脏排泄,给药96 h内,静注经尿排泄原药为81.76%,肌注为64.03%,口服为48.50%.  相似文献   
37.
苯丙烯酸对黄瓜幼苗光合作用和细胞超微结构的影响   总被引:13,自引:0,他引:13  
 通过基质栽培研究不同浓度的苯丙烯酸对黄瓜幼苗光合作用和超微结构的影响。结果表明,苯丙烯酸浓度在80 µmol·L 时显著地降低了黄瓜幼苗的叶面积、叶绿素a含量、光合速率、蒸腾速率、根系活力和气孔张开数(P<0.05);叶绿体和线粒体等超微结构也受到破坏,而浓度在150 µmol·L 时显著减少了全株干质量和气孔总数,细胞器出现解体现象。  相似文献   
38.
苹果矮化砧木‘辽砧2号’选育   总被引:2,自引:0,他引:2  
刘志  李喜森  伊凯  荣志祥  杨锋  杨巍 《果树学报》2004,21(5):501-503
从1135系的助列涅特与M9杂交实生苗中选出优良苹果矮化砧木—辽砧2号(原代号80-1-6),经过22年田间观查和区试鉴定,其矮化性、早果性、丰产性、生根性与M26相近,适应性强于M26,以其为中间砧的富士树栽后6年进入盛果期,平均株产为23.5kg,同龄M26为17.2kg;8年生树冠积为4.07m3,同龄M26为4.58m3,树体存活率较M26高55%,平均每666.7m2产量1000kg以上;与基砧山定子和生产上主栽的富士系、元帅系、国光系等品种亲和性良好,以自根砧和中间砧方式利用均可。  相似文献   
39.
AIM: To explore interaction and biological behaviour changes of two kinds of cells-blastocysts and hepatocarcinoma cells in the same microenvironment. METHODS:The models of mouse blastocysts co-cultured with human hepatocarcinoma cell lines were established, then biological behaviours and mutual effects of the two kinds of cells in co-culture system were observed. RESULTS: Compared with control group, hepatocarcinoma cells with differently invasive and metastatic potential significantly enhanced the rates of blastocyst hatchment , attachment and outgrowth(P<0.05). There was no significant difference in those among hepatocarcinoma cells co-cultured groups (P>0.05). The blastocyst hatched and attached to hepatocarcinoma cells with differently invasive and metastatic potential. Then, differential trophoblasts invaded hepatocarcinoma cells. The clear-cut interfaces were gradually formed between both sides. Hepatocarcinoma cells on interface showed changes of growth direction and cell shapes and did not invade blastocysts. CONCLUSIONS: Hepatocarcinoma cells promoted blastocyst development. Blastocysts implanted and invaded hepatocarcinoma cells with differently invasive and metastatic potential in vitro, which indicate that blastocyst implantation in vitro does not relate with the kinds and differential level of interactional cells and the low selectivity maybe relate with high adaptability of early life.  相似文献   
40.
选用中华硬蜱105kD柱层析纯化抗原对新西兰兔进行免疫接种,再用二棘血蜱进行叮咬,并与单纯二棘血蜱叮咬组和佐剂对照组进行对比,以探讨不同种属硬蜱之间的交叉免疫抗性。结果显示:单纯二棘血蜱叮咬组吸血量为181 3±44 3mg,而二棘血蜱叮咬由中华硬蜱105kD纯化抗原免疫接种组和佐剂对照组新西兰兔后其吸血量分别为102 1±25 3mg和168 5±40 9mg,纯化抗原免疫接种组较单纯二棘血蜱叮咬组和佐剂对照组吸血量分别下降43 7%和39 4%(P<0 01)。同时,纯化抗原免疫接种组也较单纯二棘血蜱叮咬组和佐剂对照组产卵量有显著下降。该研究结果表明中华硬蜱和二棘血蜱之间存在着交叉免疫反应。  相似文献   
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