Streptomycin inhibits electrophysiological changes induced by stretching of chronically infarcted rat hearts     

Jun-xian CAO  Lu FU  Qian-ping GAO  Rong-sheng XIE  Fan QU 《Journal of Zhejiang University. Science. B》2014,15(6):515-521

Objective

To investigate stretch-induced electrophysiological changes in chronically infarcted hearts and the effect of streptomycin (SM) on these changes in vivo.

Methods

Sixty Wistar rats were divided randomly into four groups: a control group (n=15), an SM group (n=15), a myocardial infarction (MI) group (n=15), and an MI+SM group (n=15). Chronic MI was obtained by ligating the left anterior descending branch (LAD) of rat hearts for eight weeks. The in vivo blockade of stretch-activated ion channels (SACs) was achieved by intramuscular injection of SM (180 mg/(kg·d)) for seven days after operation. The hearts were stretched for 5 s by occlusion of the aortic arch. Suction electrodes were placed on the anterior wall of left ventricle to record the monophasic action potential (MAP). The effect of stretching was examined by assessing the 90% monophasic action potential duration (MAPD₉₀), premature ventricular beats (PVBs), and ventricular tachycardia (VT).

Results

The MAPD₉₀ decreased during stretching in both the control (from (50.27±5.61) ms to (46.27±4.51) ms, P<0.05) and MI groups (from (65.47±6.38) ms to (57.47±5.76 ms), P<0.01). SM inhibited the decrease in MAPD₉₀ during inflation ((46.27±4.51) ms vs. (49.53±3.52) ms, P<0.05 in normal hearts; (57.47±5.76) ms vs. (61.87±5.33) ms, P<0.05 in MI hearts). The occurrence of PVBs and VT in the MI group increased compared with that in the control group (PVB: 7.93±1.66 vs. 1.80±0.86, P<0.01; VT: 7 vs. 1, P<0.05). SM decreased the occurrence of PVBs in both normal and MI hearts (0.93±0.59 vs. 1.80±0.86 in normal hearts, P<0.05; 5.40±1.18 vs. 7.93±1.66 in MI hearts, P<0.01).

Conclusions

Stretch-induced MAPD₉₀ changes and arrhythmias were observed in chronically infarcted myocardium. The use of SM in vivo decreased the incidence of PVBs but not of VT. This suggests that SACs may be involved in mechanoelectric feedback (MEF), but that there might be other mechanisms involved in causing VT in chronic MI.  相似文献   

辅助生殖技术学龄前单双胎子代的认知发展存在差异么?(英文)简   总被引：1，自引：0，他引：1  

Lan-feng XING  Yu-li QIAN  Lu-ting CHEN  Fan-hong ZHANG  Xin-fen XU  Fan QU  Yi-min ZHU 《Journal of Zhejiang University. Science. B》2014,15(1):51-57

Objective： To explore whether there exist differences in cognitive development between singletons and twins born after in vitro fertilization （IVF） or intracytoplasmic sperm injection （ICSI）. Methods： A total of 566 children were recruited for the study, including 388 children （singletons, n=175; twins, n=213） born after IVF and 178 children （singletons, n=87; twins, n=91 ） born after ICSI. The cognitive development was assessed using the Chinese-Wechsler Intelligence Scale for Children （C-WISC）. Results： For all pre-term offspring, all the intelligence quotient （IQ） items between singletons and twins showed no significant differences no matter if they were born after IVF or ICSI. There was a significant difference in the cognitive development of IVF-conceived full-term singletons and twins. The twins born after IVF obtained significantly lower scores than the singletons in verbal IQ （containing information, picture ＆ vocabulary, arithmetic, picture completion, comprehension, and language）, performance IQ （containing maze, visual analysis, object assembly, and performance）, and full scale IQ （P〈0.05）. The cognitive development of full-term sin- gletons and twins born after ICSI did not show any significant differences. There was no significant difference between the parents of the singletons and twins in their characteristics where data were collected, including the age of the mothers, the current employment status, the educational backgrounds, and areas of residence. There were also no consistent differences in the duration of pregnancy, sex composition of the children, age, and height between sin- gletons and twins at the time of our study although there existed significant differences between the two groups in the sex composition of the full-term children born after ICSI （P〈0.05）. Conclusions： Compared to the full-term singletons born after IVF, the full-term twins have lower cognitive development. The cognitive development of full-term singletons and twins born after ICSI did not show any significant differences. For all pre-term offspring, singletons and twins born after IVF or ICSI, the results of the cognitive development showed no significant differences.  相似文献   

军校研讨式教学方法改革评述   总被引：1，自引：0，他引：1  

曲亮生  吴世永  谭学者 《高等教育研究学报》2014,(4):71-75

从研讨式教学的内涵、研讨题目的设定、研讨的时机和学时分配以及研讨式教学中教师和学生的角色定位等四个方面,对近年来军校开展研讨式教学研究与实践的概况做了评述;对当前研讨式教学面临的学生课余时间精力不足、参与讨论积极性不高和课业成绩评价难等问题进行了初步探讨。  相似文献   

基于PLC应用的机、电、气综合创新教学实验平台研究——以吉林大学为例     

陈禹  曲晓海 《北京工业职业技术学院学报》2014,13(2):81-84

针对工程训练实践教学中存在的问题,分析了工科类学生理论学习与工程训练中心自身建设特点,结果表明：工科学生在高年级时需要进一步掌握较深层次的实践能力.为此,应开设一门新型实践教学课程,为高年级学生搭建基本设计和自主设计的实验平台.对机、电、气综合创新教学实验平台进行了研究,提出了实验平台的基本内容、预期效果及创新点,对高校实践教学具有一定的借鉴作用.  相似文献   

多语叙词表构建方法研究与实践     

徐红姣  高影繁  张均胜  屈鹏  曾文 《图书情报工作》2014,58(19):7

多语叙词表是实现多语言信息组织和检索,满足日益增长的多语言信息需求的重要工具资源。首先介绍多语叙词表构建的研究现状和3种主要构建方法,并对基于翻译构建多语叙词表的方法及该方法的不足进行分析,然后从汉化方法、汉语词汇的选取原则、叙词表辅助汉化平台的构建及汉化结果评价4个方面对英语EI叙词表和日语JST叙词表的汉化工作进行介绍,最后探讨下一步的研究工作。  相似文献   

社会公益类科技人才评价体系   总被引：1，自引：0，他引：1  

赵伟  高昌林  李兵  屈宝强 《中国科技资源导刊 (中国信息导报)》2014,(3):1-6

在明晰社会公益类科技人才基本概念和特征的基础上,着重探讨了价值取向理论与利益相关方理论对人才 评价体系构建的作用和影响,提出了评价原则。基于创新型科技人才评价模型,分别探讨了战略研究类人才、领域研 究类人才、基础服务类人才评价指标体系构建的导向和要点,并分析了社会公益类科技人才评价体系构建的主要机制。  相似文献   

对地掷球滚靠技术几种关系的探讨     

高卫  马志秋 《西安体育学院学报》1995,(1)

本文就地掷球的滚靠技术在比赛中的作用及如何处理好靠球与击球、方向与力度、全面发展与有所侧重、技术训练与心理训练等关系进行分析探讨，以提高教练员、运动员对其重要性的认识．  相似文献   

试论新时期我国体育报纸的现状与发展趋势     

王沂  曲明辉 《吉林体育学院学报》2006,22(1):48-49

体育报纸作为我国体育传播媒介的，重要组成部分，对我国体育事业的可持续发展以及加深对国外体育发展的认识有着重要的作用。运用文献资料、逻辑分析等研究方法，总结归纳了我国体育报纸的发展现状，并在此基础上论述了体育报纸的发展趋势，以期能为我国体育报纸的相关研究提供一些有益的参考。  相似文献   

北方高校冬季体育课程资源开发的研究   总被引：12，自引：12，他引：0  

曲新艺  张强 《冰雪运动》2006,(3):118-120

课程资源是课程设计与实施不可缺少的基本要素。因地制宜地开发各种体育课程资源,发挥课程资源应有的教育优势,体现课程资源的地方特色,对于转变学生的学习方式和教师创造性地实施《全国普通高等学校体育课程教学指导纲要》等都具有非常重要的意义。就北方高校冬季体育课程资源开发的内容、原则进行简要分析并提出建议,旨在为北方高校冬季体育课程资源的开发提供借鉴。  相似文献   

对学校体育和社区体育和谐发展的几点思考     

曲新艺  闫朝俊 《哈尔滨体育学院学报》2006,24(3)

通过对学校体育和社区体育的互动研究分析,针对学校体育与社区体育的有机结合形式,提出合理建议,对构建两者和谐发展的管理机制做有效的探索和尝试,挖掘学校体育的潜在优势,使其在社区体育中发挥应有的作用,推动全民健身运动,使二者双项参与、互惠互赢共同发展。  相似文献