卡托普利对大鼠全氟异丁烯急性吸入性肺损伤的保护作用研究

目的 探讨卡托普利对全氟异丁烯(PFIB)急性吸入性肺损伤的保护作用及其机制.方法 采用实验室自制的全身暴露动态染毒系统对实验大鼠进行吸入染毒.48只雄性Wistar大鼠随机分为正常对照组、卡托普利药物对照组、PFIB染毒对照组和PFIB染毒+低、中、高剂量卡托普利治疗组(n=8).其中PFIB染毒各组染毒剂量为260...     

大鼠头部暴露全氟异丁烯中毒致肺损伤实验模型的建立

目的：建立大鼠头部暴露吸入染毒致急性肺损伤实验模型以便进行全氟异丁烯(pefluoroisobutylene，PFIB)毒理及防治药物研究。方法：用设计的大鼠头部暴露吸入PFIB染毒装置致动物中毒，测定动物中毒后肺灌流液(BALF)中总蛋白含量和肺湿干比变化，在染毒过程中同时用气相色谱连续监测DFIB浓度。结果：在大鼠头部暴露吸入染毒中，PFIB染毒浓度比较稳定。大鼠吸入PFIB0．18mge／L(8—10min)致肺损伤实验模型比较明显，各项指标变化显著，中毒性肺水肿程度与HFIB浓时积(染毒浓度乘以时间，即CT值)呈正相关，动物中毒后12～24h肺灌流液中总蛋白含量和肺湿干比显著升高。结论：建立了大鼠头部暴露动态吸入PFIB中毒致急性肺损伤实验模型，该模型比较稳定，可用于观察动物PFIB中毒性肺水肿程度，也可作为：PFIB毒理及防治药物研究实验方法。大鼠PFIB中毒途径主要通过呼吸道吸入中毒，其吸入毒性至少比腹腔毒性大10倍。     

坦克在染毒区射击时舱内安全评价

现代坦克均安装有集体防护装置,该装置一般是基于车内战斗舱室形成超压的原理达到防护目的的。但在火炮射击时,舱内会出现瞬间负压状态,从而外界染毒空气会乘虚而入,这对乘员是否会构成威胁,本文旨在对此进行安全评估。 根据测试,火炮射击时舱内负压动态过程可用下     

病原微生物实验室实验操作对室内空气产生微生物污染的研究

目的通过模拟病原微生物实验室实验操作产生的微生物气溶胶,对实验室产生微生物污染风险进行定量研究,为实验操作人员危害评估和防护措施提供科学依据。方法使用黏质沙雷菌作为指示细菌,在实验室内对多种实验操作如吹吸混匀、培养瓶意外跌落、正常离心、离心管破裂、注射攻毒、解剖动物和安全柜泄漏等进行正常操作和意外事故模拟,使用定量空气采样和沉降平皿的方法对各种操作造成的微生物气溶胶风险进行定量分析。结果在本实验条件下,局部环境产生的微生物气溶胶浓度差异较大。吹吸混匀、培养瓶意外跌落、正常离心、离心管破裂、注射攻毒、解剖动物和安全柜泄漏产生的最大源强分别为1409、9346、<10、138、>8232、<4和>801 CFU/m3。结论病原微生物实验室各种实验操作产生的气溶胶源强差异较大,在局部环境中可以产生较高的气溶胶污染,应加强实验技能的培训和一级呼吸道防护装备的应用。     

吸入染毒毒物动力学研究装置和方法

建立了用于吸入染毒毒物动力学研究的液态毒物蒸发装置和动物吸入染毒方法。装置主要适用于沸点低于120℃液态毒物的蒸发,以沸点87.5℃的甲基肼(MMH)为对象进行测试的结果表明,该装置蒸发效率高,耗毒量少;产生的MMH蒸气浓度稳定,布毒重复性好;并且能够定量控制和调节MMH蒸气浓度。家兔经具有呼、吸活瓣的三叉管,以气管内插管和自主呼吸的方式染毒,做到了染毒个体化,在染毒期间可随时采集血、尿和呼出气样品,而且不影响家兔的正常呼吸。     

一种用于生物气溶胶检测的微环境密闭舱室的研制

目的：研制一种具备气流控制和温湿度检测功能的微环境密闭舱室用于生物气溶胶检测研究。方法利用风速传感器、温湿度传感器、电动调节阀、管道高效过滤器和真空泵组成控制系统,解决气流流向控制、温度补偿技术、压力控制和气溶胶均匀分布技术。利用Fluent 软件对该密闭舱室气溶胶浓度分布状况进行数值模拟,并测试不同位置的气溶胶浓度。结果该微环境密闭舱室由一个气密舱和一个控制柜组成,控制柜采用单片机控制,并为气密舱提供送风、排风和温湿度调控,设有单独排风模式和自循环送排风模式,且舱内保持着负压状态。数值模拟结果表明,在微环境密闭舱室内生成气溶胶5 min后,气溶胶粒子分布于整个舱室,底部气流可到达舱室上方,舱室内气溶胶浓度分布基本一致。结论该微环境密闭舱室以负压状态运行,能够避免生物气溶胶泄露,气溶胶浓度分布比较均匀,适用于进行生物气溶胶检测研究。     

返魂草素Ⅱ对小鼠全氟异丁烯吸入性急性肺损伤的预防作用

目的探讨返魂草素Ⅱ对全氟异丁烯吸入性急性肺损伤的预防作用。方法小鼠以全身暴露静态吸入全氟异丁烯方式染毒,剂量为263 mg.m-3染毒5 min。在小鼠全氟异丁烯染毒前30 min腹腔注射返魂草素Ⅱ,剂量分别为27.5、55、110 mg.kg-1。以染毒小鼠存活率、肺系数、支气管肺泡灌洗液中蛋白含量、组织病理学检查、组织超微结构检查等为观测指标,观察返魂草素Ⅱ对全氟异丁烯吸入性急性肺水肿的预防作用。结果与染毒对照组相比,返魂草素Ⅱ预防给药可显著降低全氟异丁烯染毒小鼠的湿（干）肺体比、肺含水量及肺湿/干比,明显降低支气管肺泡灌洗液中的蛋白含量,显著提高全氟异丁烯染毒小鼠的存活率,改善染毒小鼠的肺组织病变,且呈现一定的量效关系。结论返魂草素Ⅱ对全氟异丁烯所致肺水肿与炎性渗出具有抑制作用,并能有效对抗全氟异丁烯所致动物死亡。     

大鼠吸入全氟异丁烯中毒后不同时间对内源性NO及其合酶活力的影响

目的初步探讨内源性NO在全氟异丁烯（perfluoroisobutylene,PFIB）急性吸入性肺损伤中的作用。方法雄性SD大鼠,随机分为对照和PFIB染毒后1,2,4,8,16和24 h活杀组,每组4只大鼠。其中PFIB染毒组行全身暴露动态吸入PFIB染毒（剂量为140 mg/m3×5 min）,对照组行过滤空气暴露。分别在染毒前（对照组）与染毒后相应时间点,收集右肺组织、血清及左肺支气管肺泡灌洗液（bronchoalveolar lavage fluid,BALF）等标本,3H-精氨酸法测定肺组织内皮型一氧化氮合酶（eNOS）及诱导型一氧化氮合酶（iNOS）活力,酶法测定BALF及血清中NO（NO2-/NO3-）含量。结果肺组织eNOS活力在染毒后8 h内呈下降趋势,而iNOS与之相反,呈逐渐上升趋势,但与对照组比较,均没有显著差异;8 h后两者逐渐恢复至染毒前水平。血清及BALF中NO含量变化与iNOS活力相似。结论内源性NO及其合酶在PFIB急性吸入染毒前后变化不明显,在PFIB急性吸入性肺损伤中的作用尚不明确,其病理学意义有待进一步探讨。     

潜艇常见4种有害气体混合对动物呼吸和神经传导速度的影响(论著)

目的：观察二氧化碳（ＣＯ２）、二甲苯（Ｘｙｌ）、二氧化硫（ＳＯ２）、一氧化碳（ＣＯ）４种不同浓度组合成的混合气对动物呼吸频率（ＲＲ）和正中神经传导速度（ＭＮＣＶ）的影响，探讨其中影响最大的气体和浓度组合，为修订潜艇舱室空气组分容许浓度提供科学依据。方法：实验用新西兰大白兔和ＩＣＲ小鼠在动物染毒舱内对４种有害气体进行了每天４小时连续５天的吸入染毒实验。结果：４种气体中ＳＯ２是染毒早期引起动物呼吸抑制的主要因素；３个高浓度、３个中浓度、２个高浓度加１个中浓度，再分别加１个低浓度组合成的上述混合气体对动物的呼吸有较为明显的抑制作用。结论：常见的４种有害气体中，ＳＯ２是抑制呼吸的主要因素。在制订潜艇舱室容许浓度时应充分考虑这４种气体在潜艇舱室中的组分浓度。     

甲醛亚急性吸入暴露对大鼠肺组织损伤效应及炎性因子表达水平的影响

目的 研究甲醛亚急性吸入暴露对大鼠肺组织损伤及炎性相关因子的影响.方法 6周龄雄性Wistar大鼠13只(中科院实验动物中心),体质量(160±10)g,按数字表法随机分为正常对照组(对照组,6只)、甲醛亚急性吸入暴露组(暴露组,7只).正常对照组在普通室内环境中饲养28 d;暴露组采用动态气溶胶染毒暴露系统,以舱内甲醛浓度(3.1 ±0.2)mg/m3为稳定暴露浓度,每天吸入2h,连续暴露28 d,第28天暴露后在普通室内环境中放置2h.然后将2组大鼠麻醉,取肺组织,行苏木精-伊红(HE)染色,观察肺组织结构变化,Tunnel原位显色法检测肺组织细胞损伤,ELISA方法测血清白细胞介素-1β(IL-1β)、白细胞介素-8(IL-8)、肿瘤坏死因子-α(TNF-α)、clara细胞分泌蛋白(CC10)因子分泌水平,实时荧光定量PCR (realtime-PCR)方法检测暴露后大鼠肺组织炎性相关因子TNF-α、IL-1α、IL-1β,以及CASP8凋亡调控因子(Cflar)、B淋巴细胞瘤因子-3(Bcl-3)、巨噬细胞胶原结构受体(Macro)、clara细胞分泌蛋白同源因子(Scgb1 a1)表达水平的变化.结果 形态学观察表明,与对照组比较,暴露组大鼠肺泡间隔增宽,肺间质水肿,肺组织内炎性细胞侵润明显,凋亡细胞数明显增加.血清学检测结果表明,暴露组大鼠血清促炎因子水平IL-1β、TNF-α分别为(212.2±108.7)、(375.7±103.9) pg/L,较对照组[(143.8±76.5)、(137.2±112.2)pg/L]明显升高,2组比较差异有统计学意义(P＜0.05或P＜0.01);暴露组抗炎因子CC10水平[(65.2±46.3) pg/L]比对照组[(160.1±89.1) pg/L]明显下降(P＜0.05);2组IL-8差异无统计学意义(P＞0.05).Reahime-PCR检测结果与血清学检测结果趋势一致.结论 甲醛亚急性吸入暴露28 d后,大鼠肺组织促炎因子表达、释放,抑制炎性修复因子表达,造成肺组织明显损伤、修复能力降低.     

The importance and unique aspects of radiation protection in medicine

Radiation protection in medicine has unique aspects and is an essential element of medical practice. Medical uses of radiation occur throughout the world, from large cities to rural clinics. It has been estimated that the number of medical procedures using radiation grew from about 1.7 billion in 1980 to almost 4 billion in 2007. In spite of these large numbers, there are many parts of the world without adequate equipment, where the ability to perform additional medical procedures would likely result in a net benefit. Medicine accounts for more than 99.9% of the per caput effective dose from man-made sources. The goal in medical exposure is not to give the lowest dose, but to provide the correct dose to enable the practitioner to make the diagnosis or cure a tumour. Too little or too much dose is problematic and the risk of any given procedure ranges from negligible to potentially fatal. Radiation protection in medicine must deal with the issues of not having dose limits, purposely exposing sensitive subgroups, and purposely using doses that could cause deterministic effects. Radiation accidents involving medical uses have accounted for more acute radiation deaths than from any other source including Chernobyl. Many physicians have little or no training in radiation protection, and many have no qualified medical physics support. In many countries, medical radiation devices and uses are only minimally regulated and the rapidly evolving technology is a challenge. Medicine also accounts for the largest number of occupationally exposed workers and collective dose.     

江苏省2015年度放射诊断医疗照射频度调查与分析

目的 通过对江苏省4个县（区）抽样医院的放射诊断设备进行频度调查,研究江苏省放射诊断检查频度和诊断受检者的分布特点,估算全省普通放射诊断和计算机X射线断层摄影装置（CT）检查的频度。方法 采用分层随机抽样方法,将江苏省分成3个片区,在每个片区中使用随机数字表法随机抽取4个设区市,每个设区市用随机数字表法随机抽取1个县区,将4个县区内所有公立医院作为样本医院,通过样本医院中的放射信息管理系统（RIS）获得医院的放射诊断设备在调查期间的受检者性别、年龄、检查类型、检查部位等分布信息,并对结果加以分析。结果 样本中37家医疗机构共调查受检者信息728 196条,其中普通放射诊断受检者信息479 024条,CT受检者信息249 172条。样本中受检者男女比例较为平均;年龄分布中"＞40"组占比例最高,为62%。虽然一级医院数量较多,占70%,但二级医院的放射诊断频次在总频度中占比较高。各种检查类型中钡灌肠、乳腺X射线摄影等专科检查多集中于三级医院。以此次调查结果估算江苏省全省2015年普通放射诊断频度达到303次/千人口,CT扫描频度达到173次/千人口。结论 自上次放射诊断频度调查以来,江苏省放射诊断的频度水平发展较快,为开展放射卫生工作提出了较大的挑战。因此,切实采取有力措施,加强医疗照射的防护,是当前十分重要的公共卫生问题。     

我国医疗照射与保健水平的相关性研究

目的 对我国保健水平（HCL）及其影响因素进行研究。方法 利用国家统计局《中国统计年鉴》和公开文献中的数据,以全国和各省份人口和医师数量计算HCL。采用多元回归分析HCL与地区人口、面积、行政区划数量、国内生产总值（GDP）等因素间的关系。采用Pearson相关分析保健水平与医疗照射频度间关系。结果 我国从2015年起HCL值低于1 000,到2019年尚有两个省份HCL值>1 000;人口、GDP是HCL的影响因素,相关系数分别为0.416和-0.583;HCL和人群的医疗照射频度间具有一定相关性（r=-0.620,P=0.028）。结论 我国2020年的HCL值为542,各省份之间差异较大。HCL在中国作为医疗照射水平的评价指标需要进一步研究。     

对Hazelton等提出的云锡矿工肺癌主要危险来自砷的商榷

Using two-stage clonal expansion model with data-base provided by Lubin, WD Hazehon et al indicated the high risk of arsenic, but not radon, in the etiology of Yunnan tin miner' s lung cancer. The author of this review iterated the problems in the data-base of Lubin,and considered that it may result in low estimate for the risk of radon in paper of Hazehon et al. Attributable risk was estimated by them with changing exposure patterns of each individual, but the efficacy of this two-stage model will be violated by the invariability of appointed radon/arsenic exposures. Risk comparison was used to distinguish the contribution from radon/arsenic, which was hampered by the high correlation between their joint exposures. As Lubin, Hazehon et al neglected the confounding from environmental arsenic pollution in early years. From all of above, their viewpoint is worth to be deliberated.     

Assessment of the radiological safety of a Genoray portable dental X-ray unit

Objectives:

The portable dental radiographic systems are generally used in emergency situations (e.g. during natural disasters) for disabled/aged patients and in patient rooms. This study assesses the output exposure of a portable dental radiographic system measured using thermoluminescent dosemeters (TLDs).

Methods:

Occupational exposure of the operator was determined when the portable dental unit was used for mandibular and maxillary teeth exposure.

Results:

The doses of some critical organs of an operator were measured using TLDs implanted within the Rando phantom.

Conclusions:

Considering the annual organ dose limits, the eye lens dose limit is the main factor determining the frequency of system application.     

One-year,simultaneous combined exposure of CDMA and WCDMA radiofrequency electromagnetic fields to rats

Purpose:?We investigated whether one-year, long-term, simultaneous exposure to code division multiple access (CDMA; 849 MHz) and wideband code division multiple access (WCDMA; 1.95 GHz) radiofrequencies (RF) would induce chronic illness in Sprague-Dawley (SD) rats.

Materials and methods:?Two groups of 40 SD rats (50% males and females in sham and exposed groups) were exposed to CDMA and WCDMA RF simultaneously at 2.0 W/kg for 45 min/day (total 4.0 W/kg), 5 days per week for a total of one year. Body and organ weight measurements, urinalysis, haematological and blood biochemical analysis, and histopathological evaluations were performed.

Results:?The mortality patterns in male and female rats exposed to RF were compared with those found in gender-matched sham control animals. No significant alteration in body weight was observed with the simultaneous combined RF exposure. Most RF-exposed rats showed no significant alteration, based on urinalysis, haematology, blood biochemistry, or histopathology. However, some altered parameters of the complete blood count and serum chemistry were seen in RF-exposed rats. The total tumour incidence was not different between sham-exposed and RF-exposed animals.

Conclusions:?Our results suggest that one-year chronic exposure to CDMA (849 MHz) and WCDMA (1.95 GHz) RF simultaneously at 2.0 W/kg for 45-min RF exposure periods (total, 4 W/kg) did not increase chronic illness in rats, although there were some altered parameters in the complete blood count and serum chemistry.     

中国人受电离辐射照射剂量份额研究

系统总结了各种电离辐射源对正常生活条件的中国人所致照射剂量，为评价剂量－效应关系提供有意义的背景材料。方法基于大量调查研究和监测数据进行分析对比研究。结果中国人受各种电离辐射源的照射剂量，年有效剂量为２．５ｍＳｖ／ａ，来自天然辐射的剂量占总剂量的９２％。结论至今我国广大公众所受到的电离辐射照射仍以天然辐射为主。本文给出了各种电离辐射源所致剂量份额     

Positive enteric contrast material for abdominal and pelvic CT with automatic exposure control: what is the effect on patient radiation exposure?

Objective

To assess the effect of positive enteric contrast administration on automatic exposure control (AEC) CT radiation exposure in (1) a CT phantom, and (2) a retrospective review of patients.

Materials and methods

We scanned a CT phantom containing simulated bowel that was sequentially filled with water and positive enteric contrast, and recorded the mean volume CT dose index (CTDIvol). We also identified 17 patients who had undergone 2 technically comparable CT scans of the abdomen and pelvis, one with positive enteric contrast and the other with oral water. Paired Student's t-tests were used to compare the mean CTDIvol between scans performed with and without positive enteric contrast. Both the phantom and patient CT scans were performed using AEC with a fixed noise index.

Results

The mean CTDIvol for the phantom with simulated bowel containing water and positive enteric contrast were 8.2 ± 0.2 mGy, and 8.7 ± 0.1 mGy (6.1% higher than water, p = 0.02), respectively. The mean CTDIvol for patients scanned with oral water and with positive enteric contrast were 11.8 mGy and 13.1 mGy, respectively (p = 0.003). This corresponded to a mean CTDIvol which was 11.0% higher (range: 0.0-20.7% higher) in scans with positive enteric contrast than those with oral water in patients.

Conclusions

When automatic exposure control is utilized for abdominopelvic CT, the radiation exposure, as measured by CTDIvol, is higher for scans performed with positive enteric contrast than those with oral water.     

船舶次声环境对船员和动物听觉功能的影响

目的:研究船舶次声短期作用对船员和动物听觉功能的影响。方法:两艘同型船舶作为对照船和实验船，实验船次声装置连续工作6h．比较两船航后船员和动物听觉变化差异。结果:次声装置工作时，船上舱室和岗位的次声级为105～117dB．次声的频谱能量主要集中在12．5～20．0Hz。实验船员经连续6h次声作用后，普遍出现不适主观反应。动物组内耳形态的电镜观察表明，内耳有明显损伤，但船员的听力差异无显著性。结论:次声环境连续暴露6h，除使船员出现一系列不适主观反应外．还可引起听觉通道的不适；动物内耳有不同程度的损伤。     

使用X线自动摄影系统的体会

随着ｘ线诊断技术的提高，如何合理使用和实施质量保证计划正越来越受到重视。本文通过实验和对照方法，阐述了如何在不同的屏一胶系统以及药液的不同时期正确使用ｘ线自动摄影系统（ＡＥＣ）的体会。并通过实验、对照结果论证该方法在临床中应用的可行性：可以在平均剂量最低的情况下与自动洗片机匹配而获得一张具有最佳密度和良好清晰度的优质Ｘ光诊断片；最大限度地缩短病人就诊时间，提高医院的工作效率；提高优片率，降低废片率，为医院正规化建设及质量控制提供有利条件。