山东省男男性行为人群新型毒品滥用和HIV新发感染的相关因素分析

目的 分析MSM新型毒品滥用和HIV新发感染的相关因素,为制定艾滋病防控措施提供参考依据。方法 2021年4-7月在山东省9个城市监测哨点招募MSM,每个城市招募样本量为400人。开展面对面问卷调查,收集MSM社会人口学特征、行为学和接受HIV干预服务等信息,采集血样进行HIV和梅毒抗体检测。采用限制性抗原亲和力酶联免疫法进行HIV新发感染检测,并计算HIV新发感染率指标。结果 共调查MSM 3 624人,年龄（32.70±9.33）岁,以≥30岁（59.52%,2 157/3 624）、高中及以下文化程度（55.99%,2 029/3 624）、未婚/离异/丧偶（57.70%,2 091/3 624）和性取向为同性恋者为主（86.26%,3 126/3 624）。最近6个月发生无保护肛交占32.95%（1 194/3 624）;曾使用新型毒品占27.48%（993/3 613）;HIV抗体阳性率为3.12%（113/3 624）,HIV新发感染率为2.61%（95%CI：1.73%~3.49%）。多因素logistic回归分析结果显示,MSM新型毒品滥用的相关因素包括未婚/离异/丧偶（相比于已婚/同居,aOR=1.43,95%CI：1.22~1.69）、大专及以上文化程度（相比于高中及以下文化程度,aOR=1.47,95%CI：1.25~1.72）、主要寻找男性性伴场所为互联网/交友软件（相比于酒吧/浴池/公园等,aOR=1.76,95%CI：1.41~2.19）、最近6个月发生无保护肛交（相比于未发生无保护肛交,aOR=1.33,95%CI：1.13~1.57）、最近1年患过性病（相比于未患性病,aOR=2.77,95%CI：2.04~3.76）。MSM HIV新发感染的相关因素包括最近6个月发生无保护肛交（相比于未发生无保护肛交,aOR=2.51,95%CI：1.25~5.01）、最近1年未接受HIV干预服务（相比于接受HIV干预服务,aOR=3.89,95%CI：1.30~11.60）、梅毒阳性（相比于梅毒阴性,aOR=8.18,95%CI：2.98~22.48）、曾使用新型毒品（相比于未使用新型毒品,aOR=4.75,95%CI：2.32~9.70）。结论 山东省MSM新型毒品滥用现象较为普遍,新型毒品滥用会增加HIV新发感染风险。     

青岛市男男性行为人群新型毒品滥用发生率队列研究

目的 了解与分析青岛市MSM新型毒品滥用发生率及影响因素,为制定MSM艾滋病预防干预措施提供参考。方法 采用开放式队列研究方法,从2017年3月开始,依靠MSM社会组织采用滚雪球抽样方法招募未发生新型毒品滥用的MSM,建立开放队列,并每6个月进行一次随访调查,观察终点日期为2022年7月31日。调查内容包括社会人口学特征、性行为学特征和发生新型毒品滥用情况等信息。以随访过程中研究对象发生新型毒品滥用为结局因变量,以研究对象进入队列至发生新型毒品滥用的时间作为时间因变量,采用Cox比例风险回归模型分析MSM发生新型毒品滥用的影响因素。结果 共招募MSM 509人,纳入随访队列369人,发生新型毒品滥用62人,队列随访累积观察时间911.54人年,新型毒品滥用发生率为6.80/100人年。62人首次发生新型毒品滥用均为与他人共同滥用,16.13%（10/62）存在新型毒品混合滥用现象。多因素Cox比例风险回归分析显示,学生（aHR=2.17,95%CI：1.15~4.10）、最近6个月HIV检测次数0次和1次（aHR=4.57,95%CI：1.80~11.60;aHR=5.15,95%CI：2.83~9.36）、仅有固定性伴（aHR=4.75,95%CI：2.32~9.75）、同性性伴数>4个（aHR=1.70,95%CI：1.01~2.87）和性伴滥用新型毒品（aHR=12.78,95%CI：3.06~53.35）的MSM更有可能发生新型毒品滥用。结论 青岛市MSM新型毒品滥用发生率较高,存在较高HIV感染风险;发生新型毒品滥用的影响因素包括学生、HIV检测次数较少、仅有固定性伴、多性伴和性伴滥用新型毒品,应针对此部分人群加强干预力度,开展降低新型毒品危害的干预工作。     

青岛市男男性行为人群新型毒品滥用者HIV新发感染队列研究

目的 了解与分析青岛市MSM新型毒品滥用者HIV新发感染情况,为该人群开展艾滋病预防工作提供参考。方法 采用开放式队列研究方法,从2017年3月开始,由社会组织通过滚雪球抽样招募HIV阴性的MSM新型毒品滥用者,建立开放队列,并每6个月进行一次随访调查,观察终点为2022年7月31日。按照队列研究样本量计算公式估计样本量为436人。调查内容包括人口学特征、性行为特征、艾滋病知识知晓情况、新型毒品滥用情况和HIV检测情况等信息。以随访中出现HIV新发感染为结局因变量,同时,以研究对象进入队列至出现HIV新发感染的时间作为时间因变量,采用Cox比例风险回归模型分析MSM新型毒品滥用者HIV新发感染的影响因素。结果 共招募MSM新型毒品滥用者987人,纳入随访队列826人。HIV新发感染者46人,队列随访累积观察时间1 960.68人年,HIV新发感染率为2.35/100人年。多因素Cox回归分析显示,<30岁（aHR=3.04,95%CI：1.62~5.71）、外省户籍（aHR=2.29,95%CI：1.20~4.39）、线下交友（aHR=4.62,95%CI：2.05~10.41）、同性性伴数>4个（aHR=3.06,95%CI：1.59~5.88）、性交时安全套破损（aHR=2.24,95%CI：1.21~4.17）和性交时出血（aHR=2.56,95%CI：1.31~5.03）的MSM新型毒品滥用者更有可能发生HIV新发感染。结论 青岛市MSM新型毒品滥用者HIV新发感染率总体较低,但该人群知行分离的现象严重,HIV感染风险较高。HIV新发感染的影响因素包括低年龄、外省户籍、线下交友、多性伴、性交时安全套发生破损和出血,应加强开展该人群行为干预的工作。     

吉林省2010－2015年男男性行为人群HIV哨点监测分析

目的 了解吉林省MSM人群HIV的感染状况及其相关因素。方法 2010-2015年,根据《全国艾滋病哨点监测方案》的要求,在艾滋病哨点监测期内,通过横断面调查的方法对吉林省MSM艾滋病知识知晓率、性行为状况、HIV和梅毒抗体阳性率水平等进行连续监测,每个监测哨点样本量≥ 400人。结果 2010-2015年吉林省共监测MSM 7 823人,HIV感染率为5.4%（42/7 823）,HIV感染率呈逐年上升趋势（趋势χ²=110.023,P<0.001）。2010-2015年,MSM艾滋病知识知晓率均>90.0%。最近6个月坚持使用安全套的比例为27.0%（2 112/7 823）,不同年份的差异有统计学意义（χ²=234.038,P<0.001）。多因素logistic回归分析结果显示,MSM感染HIV的可能危险因素包括外省户籍（aOR=1.797,95% CI：1.185~2.726）、网络招募（aOR=1.717,95% CI：1.332~2.215）、最近1年曾诊断过性病（aOR=1.893,95% CI：1.356~2.643）和梅毒抗体阳性（aOR=4.309,95% CI：3.097~5.995）;可能保护性因素包括最近6个月同性性行为坚持使用安全套（aOR=0.387,95% CI：0.143~0.557）、最近1年曾检测过HIV （aOR=0.632,95% CI：0.375~0.891）。结论 2010-2015年吉林省MSM人群HIV感染率呈上升趋势,坚持使用安全套的比例和HIV检测率均较低,应采取有效措施促进MSM定期做HIV检测和坚持使用安全套。     

上海市艾滋病自愿咨询检测门诊男男性行为者HIV与梅毒、单纯疱疹病毒2型共感染状况调查

目的 了解上海市艾滋病自愿咨询检测（VCT）门诊就诊MSM人群HIV与梅毒、单纯疱疹病毒2型（HSV-2）共感染情况及其可能影响因素。方法 采用横断面研究设计,用方便抽样法选取上海市与普陀区的2个VCT门诊,于2015年3-8月招募≥ 18岁、最近1年发生过同性插入性性行为的MSM作为调查对象,招募756名MSM,使用χ²检验和logistic回归法分析。结果 共调查732名MSM,调查对象HIV与梅毒共感染率为3.3%（24/732）,HIV与HSV-2共感染率为1.9%（14/732）,HIV与梅毒、HSV-2共感染率为0.7%（5/732）。梅毒感染者的HIV感染率45.3%（24/53）显著高于非梅毒感染者7.2%（61/679）（χ²=63.11,P<0.001）;HSV-2感染者的HIV感染率34.1%（14/41）显著高于非HSV-2感染者10.3%（71/691）（χ²=21.49,P<0.001）。多因素logistic回归分析显示,调查对象HIV与梅毒共感染的可能危险因素包括外地户籍（OR=3.50,95% CI：1.01~12.17）、初中及以下文化程度（OR=4.46,95% CI：1.54~12.87）和曾使用毒品（OR=4.25,95% CI：1.67~10.82）;HIV与HSV-2共感染的可能危险因素：高中及以下文化程度（OR=6.87,95% CI：1.86~25.42;OR=9.82,95% CI：2.25~42.85）。结论 上海市VCT门诊就诊的MSM中存在一定比例的HIV和梅毒、HIV和HSV-2共感染情况。应关注外来务工人员、文化程度低者和使用毒品者。     

天津市2016－2018年哨点监测男男性行为人群HIV感染状况及相关因素分析

目的 了解2016－2018年天津市MSM人群HIV感染状况及其相关因素。方法 按照全国艾滋病哨点监测方案要求,采用横断面调查方法,于2016－2018年4－6月,连续监测并收集天津市MSM人群的艾滋病知识知晓率、相关性行为、以及HIV、梅毒、HCV感染等信息,各年样本量400人。结果 2016－2018年天津市监测MSM共1 200人,最近6个月同性肛交坚持使用安全套的比例为45.4%（544/1 198）,网络招募的MSM既往接受过HIV检测的比例呈现下降的趋势（趋势χ²=42.742,P<0.001）。HIV感染率为3.3%（40/1 200）,HIV-1新发感染率为2.6%（95% CI：1.7%～3.5%）,梅毒感染率为6.7%（80/1 200）,HCV感染率为0.8%（9/1 200）。多因素logistic回归分析结果显示,离异或丧偶（与未婚者相比,aOR=7.137,95% CI：1.621～31.419）、梅毒抗体阳性（与梅毒抗体阴性者相比,aOR=3.684,95% CI：1.520～8.932）是MSM人群感染HIV的危险因素;最近6个月同性肛交坚持使用安全套（与不坚持使用安全套者相比,aOR=0.343,95% CI：0.126～0.932）、既往检测过HIV抗体（与既往未检测HIV抗体者相比,aOR=0.314,95% CI：0.123～0.801）是MSM人群感染HIV的保护因素。结论 2016－2018年天津市MSM人群的HIV感染率较高,梅毒感染风险不容忽视,同性肛交坚持使用安全套的比例较低,应该采取有效措施促进MSM坚持使用安全套和定期检测HIV抗体。     

福州市2016-2021年网络招募15~24岁男男性行为人群艾滋病监测分析

目的 分析福州市15~24岁MSM艾滋病监测数据,了解其HIV感染状况及其相关因素。方法 2016-2021年通过网络方式招募年龄15~24岁最近6个月与男性发生口交/肛交性行为的MSM,分析其社会人口学和行为学特征、HIV感染状况及其相关因素。结果 2016-2021年网络招募15~24岁MSM共4 234人。户籍为福建省外的比例由13.00%（85/654）上升到23.42%（163/696）（趋势χ²=60.23,P<0.001）;通过网络寻找男性性伴的比例由93.27%（610/654）上升到99.71%（694/696）（趋势χ²=65.20,P<0.001）;最近6个月最近1次肛交使用安全套比例由88.16%（484/549）下降至74.11%（415/560）（趋势χ²=32.32,P<0.001）;最近6个月肛交每次使用安全套比例由65.76%（361/549）下降至55.54%（311/560）（趋势χ²=6.82,P<0.001）;既往接受HIV抗体检测比例由5.66%（37/654）上升到25.29%（176/696）（趋势χ²=98.51,P<0.001）。累计监测15~24岁MSM HIV抗体阳性率为3.64%（154/4 234）,历年监测15~24岁MSM的HIV抗体阳性率差异无统计学意义（趋势χ²=0.50,P=0.453）。初中及以下文化程度、居住时间1~2年者HIV抗体阳性率均呈上升趋势（P<0.05）。HIV感染风险的多因素logistic回归分析结果显示,高中/中专、大专及以上文化程度者分别是初中及以下文化程度者的0.54（95%CI：0.30~0.99）倍、0.29（95%CI：0.17~0.51）倍,本地居住时间1~2年、>2年者是本地居住时间<1年者的0.35（95%CI：0.16~0.74）倍、0.58（95%CI：0.37~0.91）倍,每次肛交坚持使用安全套者是从未使用者的0.18（95%CI：0.08~0.42）倍,未患过性病者是患过性病者的0.25（95%CI：0.13~0.50）倍。结论 福州市15~24岁MSM存在较高HIV感染风险,应加强对流动和较低文化程度青少年MSM的互联网干预。     

浙江省温州市居住5年及以下男男性行为人群艾滋病病毒感染调查

目的 分析浙江省温州市居住≤5年MSM人群HIV感染情况及相关特征。方法 2015年2－10月开展温州市MSM人群HIV感染率相关调查，采用同伴推动抽样法（respondent-driven sampling，RDS）招募年龄≥16岁、在温州市连续居住时间≥3个月、最近12个月内与男性发生肛交和/或口交的男性。问卷调查收集其社会人口学、性行为特征、认知及接受干预检测特征、心理健康状况等信息，采集血标本做HIV抗体和梅毒血清学检测。结果 RDS法共调查454例MSM，居住时间≤5年者多数以≥25岁、初中及以下文化程度、职业为服务行业和工人、个人月收入<4 000元为主，首次同性性行为年龄≥20岁、最近6个月发生同性肛交的较多。总的HIV阳性率为23.7%（108/454），居住时间≤5年者HIV阳性率为27.3%（73/267），居住时间>5年者HIV阳性率为18.8%（35/186）（χ²=4.39，P=0.036）。多因素分析结果表明，HIV感染相关因素包括25～68岁者（OR=12.19，95% CI：2.29～65.02）、最近6个月有异性性行为（OR=0.42，95% CI：0.18～0.96）、自评可能感染HIV（OR=0.06，95% CI：0.01～0.95）、自评不可能感染HIV（OR=0.03，95% CI：0.01～0.35）、现症梅毒阳性OR=3.32 （95% CI：1.05～10.52）。结论 在温州市居住≤5年的MSM相比于居住>5年者，HIV阳性率较高，存在较多的高危性行为，需开展针对性的干预措施。     

应用交友软件调查大学生男男性行为者HIV检测现状及相关因素

目的 了解活跃于移动互联网的大学生MSM最近1年HIV检测现状及相关因素。方法 按照横断面调查设计,基于中国同性恋流行使用的一款同性恋社交软件Blued,按18~25岁大学生MSM的HIV检测率50%推算样本量为500人。于2016年9月开始手机端电子问卷调查,主要收集人口学特征、HIV检测行为、性行为等信息。采用 χ²检验和非条件logistic回归分析大学生MSM最近1年HIV检测的相关因素。结果 共调查1 384名大学生MSM,平均年龄（20.99±0.04）岁,最近1年HIV检测比例为47.1%（652/1 384）。多因素分析结果显示：听说过HIV检测（OR=6.37,95%CI：3.592~11.300）,愿意定期接受HIV检测（OR=2.64,95%CI：1.191~2.631）,部分了解（OR=3.58,95%CI：2.138~5.996）和完全不了解（OR=2.25,95%CI：1.479~3.422）固定性伴HIV感染状况皆使大学生MSM的HIV检测可能性增加;信任固定性伴无感染HIV风险（OR=0.65,95%CI：0.445~0.938）,最近1年固定性伴仅为1人（OR=0.37,95%CI：0.232~0.589）使大学生MSM的HIV检测可能性降低。结论 活跃于移动互联网的大学生MSM人群最近1年HIV检测比例较低,该群体性行为活跃,固定性伴间相互信任,或仅为1人的原因,反而使HIV检测比例更低,应予以重视。     

浙江省台州市2013-2015年男男性行为者人群同性群交行为调查

目的 了解浙江省台州市MSM同性群交行为特征及其相关因素。方法 2013年3月至2015年9月,经浴室、酒吧等场所招募MSM,通过问卷调查收集其性行为等信息,并进行HIV检测。使用logistic回归模型分析群交行为相关因素。结果 共调查1 435名MSM,HIV阳性率为12.5%（179/1 435）。16.1%（231/1 435）报告在最近1年曾有群交行为。最近1年有群交行为的MSM与最近1年无群交的MSM相比,一生同性性伴数≥10个（53.7%比19.0%,χ²=125.527,P<0.01）、有异性性伴（86.6%比68.2%,χ²=31.935,P<0.01）、最近1年与女性发生性行为未使用安全套（28.1% 比19.8%,χ²=6.540,P<0.05）的比例更高。多因素logistic回归模型分析显示,与MSM群交行为相关因素包括年龄（≥50岁比≤24岁,aOR=2.25,P=0.027）,与女性婚姻（离异或丧偶比未婚,OR=0.29,P=0.001）,户籍（本地比外地,aOR=1.56,P=0.023）,一生同性性伴数（≥21个比2~5个,aOR=8.06,P<0.001;11~20个比 2~5个,aOR=3.25,P<0.001）,一生异性性伴数（≥6个比0个,aOR=2.63,P=0.005;2~5个比0个,aOR=2.58,P=0.001;1个比0个,aOR=2.01,P=0.010）。结论 台州市MSM人群群交行为比例较高、安全套使用率低、性行为关系复杂,HIV感染率高、传播风险较大。     

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.