超声对胚胎及胎儿安全性研究新进展

超声诊断的安全性问题一直受到医学界和学术界的关注.近年来,不断有新的超声技术应用于产科,增加了超声产生生物学效应的危险.不同发育阶段胚胎接受超声辐射可引起胚胎细胞凋亡增加、DNA损伤、胚胎畸形,甚至死亡,而且可能影响胎儿的生长发育.就不同超声技术引起生物学效应的机制及胚胎发育不同时期行超声检查对胚胎及胎儿的影响作如下综述.     

超声对胚胎及胎儿安全性研究新进展

超声诊断的安全性问题一直受到医学界和学术界的关注。近年来，不断有新的超声技术应用于产科，增加了超声产生生物学效应的危险。不同发育阶段胚胎接受超声辐射可引起胚胎细胞凋亡增加、DNA损伤、胚胎畸形．甚至死广，而且可能影响胎儿的生长发育。就不同超声技术引起生物学效应的机制及胚胎发育不同时期行超声检查对胚胎及胎儿的影响作如下综述。     

国外工业超声波的测试及其卫生标准

工业超声波使用的频率为10KHz～10MHz,其强度为10~(-3)W/cm~2～10~5W/cm~2,大多数大功率超声设备为20～60KHz。延迟线路与控制器、医用超声设备使用的频率多为兆赫(MHz)和功率密度毫瓦(mw/cm~2)的范围。 大功率超声辐射动物实验可引起各种不良的生物学效应。如生物物理学的热效应,组织裂解机理,耦合腔穴作用,以及超声对耳、眼、睾丸、神经系统,畸胎,遗传与细胞方面的生物效应。     

自聚焦超声在动物离体皮下脂肪组织中的融脂效应研究

目的：探索高频聚焦超声和低频聚焦超声在不同辐照时间和功率的条件下,对离体动物猪的皮下脂肪不同层产生生物学融脂效应的规律。方法：将离体动物猪脂肪生物实验分为两组,分别使用工作频率为6．5MHz和3MHz的换能器。两组使用的超声功率为2～5w,辐射时间为5S、10S、20S、4s、60s和80S;辐照后进行MTT检测脂肪细胞活性并计算融脂效应的面积。描述离体动物猪的皮下脂肪层生物学融脂效应,讨论不同条件下生物学融脂效应之间的区别。结果：随着超声功率和辐照时间的增加,脂肪组织形成融脂效应的程度呈规律性变化。辐照时间为5s时脂肪组织破坏不明显,辐照时间〉10s时脂肪组织则明显被破坏。相同超声功率和辐射时间条件下聚焦超声在深脂肪层的破坏程度比浅表脂肪层高。3MHz聚焦超声在辐射时间≥40s可穿过约5mm的表皮并凝固性破坏皮下不同层次的脂肪组织。结论：高频和低频聚焦超声均可有效破坏脂肪组织。     

超声波生物学效应及产科超声检查的安全性

产科超声检查技术已从原来的二维黑白超声、频谱多普勒超声、彩色多普勒超声发展到现在的三维、四维超声。本文主要介绍自20世纪70年代至今,中外学者对超声生物学效应的大量研究,包括动物研究、人体研究及流行病学研究,并且指出,目前关于三维、四维超声检查对胎儿的生物学效应研究较少,广大超声工作者对这方面研究应重视起来。     

低剂量辐射生物效应的研究进展

低剂量辐射(low-dose radiation,LDR)生物效应仍然是放射生物学领域的研究热点.随着研究的深入,对LDR产生的各种生物效应及其机制不断完善.越来越多的证据表明,LDR诱导的生物效应和高剂量辐射不同,这些研究对"线性无阈"模型提出质疑.本文从LDR诱导的旁效应、兴奋效应、适应性反应以及低剂量辐射超敏感性...     

纳米材料生物安全性评价的研究进展

目前,纳米材料生物安全性评价体系的建立还处在探索阶段,对纳米材料生物安全性评价还主要集中于对其健康效应的毒理学研究,而针对纳米材料的系统人群流行病学研究开展较少。     

超声空化的研究及应用

超声空化已成为当前医学超声研究的热题,其应用尚在探索阶段。为了引起超声空化在超声治疗设备的工程设计、 临床使用的安全有效和医学生物效应研究等方面的注意,本文阐述了超声空化的基本原理和研究成果,分析了在 不同设备中发生或应用空化效应的利与弊。文中介绍了高强度聚焦超声（HIFU）治疗机制中的几种学术观点。     

电磁波的生物学效应

简述了电磁波生物学效应的概念，电磁波生物学效应和非热效应的含义及各自的特点。概要列举了电磁波在不同生物层次上产生的生物学效应的典型事例，并依据作者开展的实现研究概要列举了电磁波生物学非热效应的典型代表，即窗效应的典型事例。     

毒理学生物标志的研究

毒理学是近年来发展迅速的研究领域之一 ,它用先进科学技术研究环境污染物进入人体后引起疾病 (中毒 )的生物学变化过程 ,特别是观察毒效应的生物标志。检测生物标志物方法学的更新 ,必将对毒效应产生新认识 ,毒理学安全性评价也随之带来新变革。回顾上个世纪 60年代以来 ,由于基因突变、染色体损伤和ＤＮＡ损伤检测在毒理学的广泛应用 ,致突变作用作为一种特殊毒效应已列入毒理学的篇章和毒理学安全性评价程序。近年来又有新的进展 ,由于基因芯片技术的应用 ,有可能快速检出产生毒效应的一些易感基因 ,成为可供检测的易感生物标志 (ｓｕｓ…     

Lauriston S. Taylor Lecture: Assuring the safety of medical diagnostic ultrasound

In 1980, the NCRP formed Scientific Committee 66 with an assignment to address the subject of "biological effects of ultrasound and exposure criteria." It was recognized that the primary source of exposure to ultrasound was through medical applications and, especially, through procedures employing diagnostic ultrasound. While the risk to patients from these procedures was believed small, it was considered important for users to understand it, in view of the widespread use of diagnostic ultrasound. In proceeding with this assignment, much emphasis has been given to the mechanisms by which ultrasound can bring about changes in biological structures or processes. Thermal effects are possible; the local temperature can rise especially rapidly where ultrasound impinges on bone. From theory for heat production and transport, and by analysis of experimental results with mammals, information has been obtained for guiding users in avoiding harm from temperature elevation. Nonthermal effects, such as capillary rupture, can occur when ultrasound is incident on tissue that normally contains gas-filled cavities, as in adult lung or intestine, or on any tissue containing gaseous contrast agents. Theory from fluid dynamics, together with experimental findings, has led to quantitative guidance for avoiding damage from acoustically activated cavities. It is felt that good practice in applying diagnostic ultrasound is best assured by making it possible for users to be well informed on safety matters so that they can feel justifiably confident in making appropriate choices of operating conditions. A promising and useful approach is in the display of safety information on the diagnostic ultrasound screen, which is now a feature of United States standards.     

妇科急腹症的超声诊断及误诊原因分析

目的：探讨超声在妇科急腹症诊断中的应用价值,并分析误诊原因。方法选择2011年12月～2013年12月我院诊治的237例妇科急腹症患者,所有患者均进行腹部超声检查和阴道超声检查,随后经手术确诊,比较各自及联合检查的诊断准确率。结果阴道超声检查的诊断准确率（90.3%）明显高于腹部超声检查（83.5%）,联合检查的诊断准确率（96.2%）明显高于单项检查,差异均有统计学意义（P＜0.05）。结论腹部超声和阴道超声联合检查可显著提高妇科急腹症的诊断准确率,值得推广。     

The safety of prenatal ultrasound exposure in human studies

Diagnostic ultrasound use in obstetrics has been growing rapidly to become an integral part of prenatal care today. The high proportion of exposure to prenatal ultrasound highlights the public health significance of routine ultrasound use. A majority of epidemiologic studies tends to support the safety of diagnostic ultrasound use during pregnancy. However, there have been some reports that there may be a relation between prenatal ultrasound exposure and adverse outcome. Some of the reported effects include growth restriction, delayed speech, dyslexia, and non-right-handedness associated with ultrasound exposure. Continued research is needed to evaluate the potential adverse effects of ultrasound exposure during pregnancy. These studies should measure the acoustic output, exposure time, number of exposures per subject, and the timing during the pregnancy when exposure(s) occurred, while controlling for potential confounding variables such as sociodemographic, medical, and obstetric risk factors. We recommend that a new consensus development conference be held to gather the needed data and provide guidelines for the future research needs, as well as respond to the rapid advances in this technology.     

植入材料及其生物相容性评价的研究进展

随着现代材料科学、生命科学以及医学科学的发展,植入材料在临床医学领域的应用日趋广泛,对其进行合理的临床前生物相容性评价是确保人体安全应用的前提。本文将就植入材料的进展及其生物相容性评价的特点、研究现状及发展趋势作简要评述。     

诊断剂量的超声辐射对人类早孕绒毛和蜕膜组织细胞的影响

目的:探讨不同辐射时间的诊断超声检查对早期妊娠绒毛和蜕膜细胞的影响。方法:将50例正常早期妊娠妇女随机平均分为对照组(0辐射)、Ⅰ组(5min辐射)、Ⅱ组(10min辐射)、Ⅲ组(20min辐射)和Ⅳ组(30min辐射),共5组,在超声辐射后24h取绒毛和蜕膜组织进行细胞凋亡状态检测。结果:持续20min以上的诊断剂量超声辐射使绒毛细胞凋亡水平上升,持续30min以上的诊断剂量超声辐射使蜕膜细胞凋亡水平上升(P<0.05)。结论:诊断剂量的超声辐射可以诱导早孕绒毛和蜕膜细胞凋亡,而且随着辐射时间的延长细胞凋亡水平不同程度的增高,从优生优育方面的考虑,早期妊娠超声诊断应在尽可能短的时间内完成。     

On the safety of diagnostic ultrasonography in obstetrics and gynecology

Considering the safety of diagnostic ultrasound in obstetrics and gynecology we reviewed data from experimental studies as well as human data. It is concluded that when performed for specific medical indications, diagnostic ultrasonography is safe.     

一种扇形扫描三维超声成像系统三维重建方法

三维超声成像技术恢复了二维超声图像成像过程中丢弃的空间位置信息,提供了比二维超声图像更为丰富的临床诊断信息,已广泛应用于临床诊断领域.本文介绍了基于一维换能器阵列的超声三维重建过程,针对扇形扫描三维超声成像系统提出了一种减少三维重建环节的处理方法.     

胎盘植入的多种二维彩色多普勒超声诊断价值研究

目的回顾性分析可疑胎盘植入患者的超声检查及超声声像图特征,归纳有关胎盘植入的超声诊断标准和检查方法,以提高胎盘植入的诊断符合率。方法将患者分组,应用不同的超声方法进行诊断,并将效果进行比较。结果应用经腹＋经阴道二维彩色多普勒超声检查和应用普通经腹＋经阴道＋高频浅表二维彩色多普勒超声检查具有较好诊断效果。结论多种超声检查方法的联合应用能提高胎盘植入的诊断准确率。     

生物材料和医疗器械的生物学评价

生物材料和医疗器械的生物学评价是当前生物材料和医疗器械市场和应用能否健康蓬勃发展的关键。随着现代材料科学，生命科学以及医学科学的发展，生物材料在临床医学领域的应用已日趋广泛，而材料和器械的临床前生物学评价则是确研究的现状，存在的问题以及发展趋势等作一简要的评述。     

Ultrasound imaging during pregnancy

Review by a panel of experts convened by the National Institute of Health (NIH) and the Federal Food and Drug Administration (FDA) resulted in a recommendation for diagnostic ultrasound imaging in about 1/3 of pregnancies only when medically indicated but not routinely. Ultrasound technology, 1st developed for use in submarine warfare sonar devices, is widely used by physicians because of its clinical significance and because it allows seeing intrauterine structures without exposing the fetus to dangerous radiation. Its most important uses include estimating the gestational age for patients with uncertain clinical dates, evaluating fetal growth, determining the cause of vaginal bleeding, determining fetal presentation, identifying multiple gestation, supplementing amniocentesis or other special procedures, diagnosing, confirming fetal death and locating intrauterine devices. Recently, many physicians have been advocating routine ultrasound screening of all pregnancies but this is an issue of concern among leading physicians and the NIH. The panel stressed the urgent need for additional research on the safety and efficacy of the procedure. Many studies that found adverse reactions associated with ultrasound use in humans suffer from sever methodological flaws. The panel recommended ultrasound not to be used for routine screening. Some studies indicate that no clear benefit from routine screening results. The panel's recommendations were criticized for unnecessarily restricting ultrasound use and for inappropriately sanctioning widespread use of the technology. Human Life International, an anti-abortion organization, opposed using ultrasound to detect fetal abnormalities, contending that this would promote abortion. Some abortion opponents, however, believe ultrasound would cause bonding between the mother and the fetus and discourage abortion. The panel underscored the importance of the skill and training of ultrasound examiners. In regard to informed consent, the panel recommended that it be obtained. Further intensive research on the use of ultrasound was highly recommended.