气管滴注大气细颗粒物对大鼠的急性毒性

目的 探讨大气细颗粒物(PM2.5)对大鼠的急性毒性作用及其可能的作用机制.方法 将28只体重为280～310 g的雄性Wistar大鼠随机分为4组,即空白对照组、颗粒物低、中、高剂量组(7.5、15和30 mg/kg).采用一次性气管滴注染毒颗粒物,24h后处死动物,进行支气管肺泡灌洗液(BALF)细胞计数,并对BALF中总蛋白(TP)、乳酸脱氢酶(LDH)和炎性因子(IL-6、TNF-α)的水平进行测定.同时观察了不同染毒组大鼠血清中炎性因子(IL-6、TNF-α)和C-反应蛋白(CRP)的水平.结果 各染毒组大鼠BALF白细胞总数、中性粒细胞数、TP及TNF-α水平均较对照组高,差异均有统计学意义(P＜0.05或P＜0.001).与对照组比较,各染毒组大鼠血清IL-6和CRP水平升高,差异均有统计学意义(P＜0.05或P＜0.001);中、高剂量组TNF-α水平升高,差异均有统计学意义(均P＜0.05).结论 大气细颗粒物能引起染毒大鼠肺脏急性损伤和全身炎症,后者可能与其心血管系统损伤机制有关.     

大气细颗粒物对自发性高血压大鼠心血管系统的影响

[目的]观察气管滴注大气细颗粒物(PM2.5)对自发性高血压大鼠(SHR)心血管系统的影响. [方法]将24只雄性SPF大鼠随机分为生理盐水对照组及PM2.5染毒低、中、高剂量(分别为1.6、8.0、40.0 mg/kg体重)组,各剂量组均经气管滴注染毒3d.末次染毒24h后,监测记录大鼠的血压、心率和心电图,取腹主动脉血测定大鼠血浆内皮素1(ET-1)、P-选择素和D-二聚体浓度. [结果]与对照组相比,PM2.5各染毒剂量组血压和心率均升高(P＜0.05),心率变异性降低(P＜0.05),大鼠血浆ET-1水平明显升高(P＜0.05).中、高剂量PM2.5暴露可引起大鼠血浆P-选择素和D-二聚体水平明显升高(P＜0.05). [结论] PM2.5气管滴注可导致大鼠心脏自主神经功能异常并改变凝血纤溶的平衡.     

一次性气管滴注PM10所致大鼠肺脏和心脏的炎症反应

目的观察大气可吸入颗粒物一次气管滴注染毒后,大鼠肺脏、心脏的炎症反应,初步探讨大气可吸入颗粒物对大鼠的急性损伤及可能的作用机制。方法将32只体重为380～470g的雄性Wistar大鼠随机分为4组,即空白对照组、颗粒物低、中、高剂量组(5、15和45mg/kg)。采用气管滴注染毒颗粒物,24h后处死动物,进行支气管肺泡灌洗液(BALF)细胞计数,并对BALF中总蛋白(TP)、乳酸脱氢酶(LDH)和炎性因子(IL-6、TNF-α)的水平进行测定;采用实时荧光定量逆转录-聚合酶链反应(realtimeRT-PCR)法检测各组心肌组织白细胞介素6mRNA(IL-6mRNA)的表达,并观察心脏、肺脏组织病理切片。结果各染毒组大鼠BALF白细胞总数、中性粒细胞数、TP、LDH及IL-6水平均较对照组高,差异有统计学意义(P﹤0.05),BALF中TNF-α含量较对照组有所增加,但差异无统计学意义。中、高剂量染毒组大鼠心肌IL-6mRNA水平较对照组显著升高(P﹤0.05)。肺组织病理显示大鼠肺部炎症,各染毒组均可见炎性细胞浸润,中、高剂量组还能看到肺泡壁增厚,肺泡间隔增宽,并可见散在黑色颗粒状物质沉积。心肌组织病理未见异常。结论可吸入颗粒物一次性气管滴注染毒后可引起大鼠肺脏炎症损伤,进而造成心肌的炎性反应,大气可吸入颗粒物可能通过炎性机制造成脏器损伤。     

白菜、豆角对大鼠甲状腺的影响

目的研究富硫氰酸盐(白菜)、类黄酮类(豆角)榨汁液对大鼠甲状腺的影响及其机制。方法 Wistar大鼠60只,随机分为对照组(NG),白菜汁组(CG),豆角汁组(BG),豆角汁+白菜汁低(LG),中(MG),高(HG)剂量6组,豆角汁与白菜汁为等体积混合,分别按1ml/100g bw给予大鼠0.9%生理盐水,CG汁3.16g/ml,BG汁3.16 g/ml,LG混合汁1.0 g/ml,MG混合汁3.16 g/ml,HG混合汁9.9 g/ml,喂养30 d,采血并摘取甲状腺,观察榨汁液对甲状腺结构与功能的影响。结果单一豆角组(BG)、联合高剂量组(HG)大鼠甲状腺脏器系数与正常对照组(NG)比较显著增加(P<0.05,P<0.01),其它组影响不明显。一般病理切片各组均未见明显甲状腺肿,但白菜组(CG)、豆角组(BG)、联合高剂量组(HG)与正常对照组(NG)比较可观察到细胞间结缔组织增生,HG较CG、BG增生更为明显;透射电镜下联合各剂量组与BG、CG比较,可观察到粗面内质网脱颗粒、线粒体嵴消失现象,个别细胞高尔基复合体不规则,而与NG比较,各组上述变化均较明显。同时发现游离甲状腺素(FT4)在BG、HG组水平均低于NG(P<0.05,P<0.01)。结论人群日常硫氰酸盐、类黄酮类食物摄食剂量对甲状腺有一定影响,且随着摄食剂量增加或/和外源性补充富含硫氰酸盐、类黄酮类物质,其致甲状腺肿的损伤作用更加明显。提示潜在甲状腺病史人群(遗传性、家族性,碘缺乏地区等)应控制摄入富含硫氰酸盐、类黄酮类食物。     

清肺化痰中药对大气PM2.5致大鼠肺损伤的干预作用研究

目的探讨中药清肺化痰丸对大气PM2.5致大鼠肺损伤的干预作用。方法于某居住区采集大气PM2.5。健康成年SD雄性大鼠64只随机分为8组:每组8只,分别为空白对照组(不做任何处理)、生理盐水对照组(气管滴注1.5 ml/kg生理盐水)、溶剂对照组(每天灌胃给予10 ml/kg的0.2%羧甲基纤维素,共1周)、干预对照组(每天灌胃给予2.40 g/kg清肺化痰丸,共1周)、染毒对照组(气管滴注40 mg/kg的PM2.5生理盐水混悬液染毒,隔天1次,共3次)以及低、中、高剂量干预组(气管滴注40 mg/kg的PM2.5生理盐水混悬液染毒,隔天1次,共3次,再每天分别灌胃给予0.65、1.20和2.40 g/kg清肺化痰丸,共1周。收集肺泡灌洗液(BALF)进行细胞计数,并测定BALF中酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、乳酸脱氢酶(LDH)、总蛋白(TP)、白蛋白(ALB)、白介素-1β(IL-1β)、白介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)水平。结果与生理盐水对照组比较,染毒对照组大鼠BALF中ACP、AKP、LDH活力和TP、ALB、IL-6、IL-1β、TNF-α含量及中性粒细胞百分比均升高,差异均有统计学意义(P0.05)。与染毒对照组比较,各剂量干预组大鼠BALF中ACP、AKP、LDH活力和TP、ALB、IL-6、IL-1β、TNF-α含量及中性粒细胞百分比均降低,差异均有统计学意义(P0.05),且随干预剂量的升高其降低幅度增加。结论中药清肺化痰丸对气管滴注PM2.5导致的肺损伤有一定减轻作用。     

富硒酵母对大气细颗粒物致大鼠肺损伤的干预作用

目的探讨富硒酵母对大气细颗粒物(PM_(2.5))致大鼠肺损伤的干预作用。方法 56只健康成年SD大鼠随机平均分为7组:生理盐水对照组(气管滴注生理盐水);PM_(2.5)染毒组(气管滴注PM_(2.5)混悬液,40 mg/kg,隔天一次,共3次);溶剂对照组(1%羧甲基纤维素灌胃);低、中、高剂量干预组(气管滴注PM_(2.5)混悬液,末次滴注24h后,分别灌胃给予富硒酵母8.75、17.5和35 mg/kg,每天1次,共7d);干预对照组(35 mg/kg富硒酵母灌胃)。末次灌胃24 h后,收集肺泡灌洗液(BALF),测定BALF中肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、丙二醛(MDA)、总蛋白(TP)含量及总超氧化物歧化酶(T-SOD)、谷胱甘肽过氧化物酶(GSH-Px)、乳酸脱氢酶(LDH)及碱性磷酸酶(AKP)活性,并计数细胞。未灌洗肺叶制作病理切片。结果与对照组相比,PM_(2.5)染毒组及低、中、高剂量干预组BALF中中性粒细胞百分比、TNF-α、IL-1β、TP及MDA含量,LDH及AKP活性增高,GSH-Px及T-SOD活性下降(P0.05)。与PM_(2.5)染毒组相比,干预组BALF中中性粒细胞百分比、TNF-α、IL-1β、TP及MDA含量,LDH及AKP活性降低,GSH-Px及T-SOD活性升高(P"0.05),随干预剂量增加,中性粒细胞百分比、TNF-α、IL-1β、TP及MDA含量,LDH及AKP活性降低,GSH-Px、T-SOD活性升高幅度增加。结论富硒酵母可适当减轻PM_(2.5)所致大鼠肺组织炎性损伤及氧化应激损伤。     

鳕鱼皮胶原蛋白肽对小鼠慢性四氯化碳肝损伤的保护作用研究

目的以鳕鱼皮胶原蛋白肽为原料,探讨其对慢性肝损伤模型小鼠的保护作用。方法 ICR雄性小鼠50只,随机分为5组,每组10只,分别为正常组(NG)、模型组(MG)、阳性药物组(PG)、CSCP低剂量组(LG)和CSCP高剂量组(HG)。除NG外,其余组小鼠腹腔注射CCl4花生油溶液,每周3次,连续8w。在第4w末,PG每日灌胃给予联苯双酯溶液(150 mg/kg bw),LG和HG每日以CSCP溶液灌胃,剂量分别为200、400 mg/kg bw,NG和MG每日以等量纯水灌胃。饲养8w后处死小鼠,收集血清和肝脏。测定血清中谷氨酰转肽酶(у-GT)、碱性磷酸酶(ALP)的活性,肝脏中谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)的水平;透射电镜观察小鼠肝组织病理学变化;免疫组化法测定肝脏中TNF-α的表达水平。结果 CCl4诱导小鼠肝脏发生病变,LG、HG显著降低肝损伤小鼠血清中у-GT和ALP活性,与MG比较,ALP值在HG降低了11.76%;肝脏中GSH-Px和CAT水平升高,与MG比较,CAT值在HG升高幅度为20.63%;肝脏病理损伤程度明显改善。结论鳕鱼皮胶原蛋白肽对小鼠慢性肝损伤有着保护作用。     

大气细颗粒物及铅化合物对大鼠肺及血液的毒性

[目的]观察气管滴注大气细颗粒物（PM。）和3种铅化合物（PbSO4、PbCl2和PbO）对大鼠的急性肺毒性及血液毒性作用。[方法]将78只雄性Wistar大鼠随机分为生理盐水对照组、PM2.5染毒组（低、中、高染毒剂量分别为1．6、8．0、40．0mg／kg体重）、PbSO4、PbCl2和PbO染毒组。其中,3种铅化合物的低、中、高染毒剂量分别为13．5、67．5、337．5μg/kg体重。各剂量组均经气管滴注连续染毒3d。末次染毒24h后,收集支气管肺泡灌洗液（BALF）进行细胞计数,测定乳酸脱氢酶（LDH）、碱性磷酸酶（AKP）、酸性磷酸酶（ACP）、白蛋白（ALB）及总蛋白（TP）的含量;收集血液测定全血中δ-氨基-γ酮戊酸脱水酶（δ-ALAD）活性。[结果]PM25及3种铅化合物均可致大鼠BALF中的中性粒细胞比例明显升高,巨噬细胞比例明显降低;随着染毒剂量的增加,BALF中LDH、AKP、ACP、TP和ALB含量随之升高,呈现出一定的剂量效应关系,且PM2.5引起的上述作用较铅化合物明显。3种铅化合物两两比较发现,硫酸铅组对中性粒细胞比例、巨噬细胞比例、AKP、ACP和TP的作用较为明显。末次染毒24h后,大鼠全血中δ-ALAD活性随染毒剂量的升高而降低,PM2.5组作用较铅化合物明显;3种铅化合物中,硫酸铅的降低作用最明显。[结论]气管滴注PM2.5和3种铅化合物均可引起Wistar大鼠的急性肺毒性及血液毒性;与含同剂量铅的PM2.5相比,铅化合物的作用较弱。而3种铅化合物的毒性也互不相同,其中硫酸铅的毒性最大。     

气管滴注二球悬铃木花粉对大鼠肺部的急性损伤作用

目的了解二球悬铃木花粉对大鼠肺部的急性损伤作用。方法将30只雄性SD大鼠随机分为对照组、低剂量组和高剂量组。根据WHO空气质量准则设计此次试验的染毒剂量分别为2 mg/ml和10 mg/ml。采用单次非暴露式气管滴注法染毒,24 h后处死动物,经腹主动脉采血,收集支气管肺泡灌洗液(BALF)进行细胞计数,测定灌洗液中乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)、丙二醛(MDA)、肿瘤坏死因子(TNF-α)和谷胱甘肽过氧化物酶(GSH-Px)水平,并观察肺组织病理改变。结果高剂量组WBC、RBC、Hb和MCV均出现了变化,差异具有统计学意义(P0.05)。各染毒组大鼠BALF中白细胞总数、中性粒细胞数、MDA、TNF-α和LDH水平较对照组升高,差异具有统计学意义(P0.05),SOD和GSH-Px水平降低(P0.05)。肺组织病理学结果显示,各染毒组可见明显的炎性细胞浸润,肺泡壁增厚,肺泡腔扩大,部分肺泡间隔断裂。结论气管滴注二球悬铃木花粉能够导致SD大鼠肺部氧化损伤,破坏了机体氧化和抗氧化系统的平衡,并对血液学部分指标产生了影响。     

大气污染物所致大鼠深部呼吸道损伤的研究

目的 探讨大气污染物引起机体呼吸道炎症的机制，为控制大气污染、制定防治对策提供依据。方法 将体重在180—220g的80只大鼠随机分为4组，即对照组、低剂量组、中剂量组、高剂量组，分别进行颗粒物和SO2、NO2染毒，颗粒物染毒采用气管注入法，各注入颗粒物7．5，15，30mg，灌注体积为lm1，对照组注入同体积的生理签水。染尘后的第2d，再进行SO2和NO2混合气体染毒，低、中、高剂量组的SO2和NO2的浓度分别为8，5；16，10；32，20mg／m^3，对照组为空气。连续染毒7d后，于染毒后的第ld处死一半大鼠，第8d处死其余大鼠。分别进行血清中酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、唾液酸(SA)、乳酸脱氢酶(LDH)、铜蓝蛋白(CP)、总蛋白、白蛋白和肺泡灌洗液(BALF)中ACP、AKP、SA、LDH、总蛋白的测定。结果 染毒后第ld，高剂量组大鼠血清中AKP、SA、CP白蛋白水平高于对照组，有显性差异(P＜0．05)，第8d高剂量组大鼠血清中SA、CP、白蛋白水平高于对照组(P＜0．05)。高剂量组大鼠染毒后第ld BALF中SA、LDH、和总蛋白水平高于对照组(P＜0．05)；第8d LDH和总蛋白仍呈高水平(P＜0．05，P＜0．01)。结论 大气污染物可致大鼠肺泡膜破坏，可能是呼吸道和肺部损伤的机制之一。     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

The occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.