锌指蛋白基因IKZF3多态性与中国长江以南汉族人群系统性红斑狼疮的病例对照研究

目的 研究IKZF3基因多态性与中国长江以南汉族人群系统性红斑狼疮（SLE）易感性间的关联性。方法 采用病例对照研究（SLE 213例,正常健康对照者234例）,应用聚合酶链式反应-限制性片段长度多态性（PCR-RFLP）方法检测IKZF3基因多态性。在多个遗传模型（加性、隐性、显性）下,利用多因素logistic回归模型和广义多因子降维模型（GMDR）,分析基因与疾病易感性、疾病临床表型之间的关系,以及基因-基因交互作用,并进行生物信息学分析。结果 IKZF3基因rs114509391位点CA基因型的个体较AA基因型的个体患SLE的风险下降（OR=0.14,95%CI：0.03～0.56,P=0.006）;且在显性模型仍存在统计学意义（OR=0.26,95%CI：0.09～0.81,P=0.02）。分层分析提示rs9635726和rs9909593两位点可能与SLE发病也存在关联。表型研究显示,rs907091位点与肾脏损害（加性模型：OR=0.59,95%CI：0.35～0.98,P=0.043）、抗SSB抗体阳性（显性模型：OR=0.41,95%CI：0.18～0.96,P=0.040）相关;rs9909593位点GG、GA基因型的患者出现抗SSB抗体阳性的风险也较AA基因型患者下降（OR=0.37,95%CI：0.16～0.88,P=0.025）。生物信息学分析提示研究位点为功能位点。结论 IKZF3基因rs114509391、rs9635726和rs9909593可能与SLE易感性相关,rs9909593、rs907091与SLE的临床表型相关。     

HLA-DP基因2个单核苷酸多态性位点与贵州少数民族人群HBV感染的关联研究

目的 研究贵州省世居少数民族(布依族、苗族和水族等)人群人类白细胞抗原(HLA)-DP基因rs3077和rs9277535位点多态性与HBV感染的相关性。方法 采用病例-对照研究,募集布依族、苗族和水族等共计256例HBV感染者作为病例组,同时选取142例HBV自限性感染者和135例健康人群作为对照组。应用TaqMan-MGB探针实时荧光定量PCR单核苷酸多态性分型技术对HLA-DP基因rs3077和rs9277535位点进行分型。结果 HBV感染组、HBV自限性感染组和健康对照组相比:HLA-DP基因rs9277535位点的等位基因在HBV感染组和健康对照组之间分布差异有统计学意义(P<0.05),rs3077位点的等位基因和基因型在各组间的差异无统计学意义(P>0.05)。显性模型下各组之间基因型频率比较:HLA-DP基因rs9277535位点在HBV感染组和健康对照组之间的差异有统计学意义(P<0.05),进一步校正年龄、性别因素后显示,AA+AG基因型与GG基因型相比为乙型肝炎(乙肝)易感的保护因素(OR=0.645,95%CI:0.421~0.988);rs3077位点在各组间比较均无统计学意义。性别分层后的显性模型下显示,男性携带rs3077位点CC+CT基因型与TT基因型相比为乙肝易感的保护因素(OR=0.493,95%CI:0.266~0.916);rs9277535位点在显性模型下各组比较基因型的分布差异无统计学意义。在布依族、苗族和水族人群中比较各组中等位基因和基因型分布,HLA-DP基因rs3077位点的基因型在布依族HBV感染组与健康对照组中的分布差异有统计学意义(χ²=6.726,P=0.036)。结论 HLA-DP基因rs9277535位点携带A等位基因可能是乙肝易感的保护因素,男性携带rs3077位点C等位基因可能是乙肝易感的一个保护因素,rs3077和rs9277535位点多态性与HBV的自限性感染可能无关。HBV感染者HLA-DP基因rs3077位点的基因型分布存在民族间的差异。     

核转录因子κB基因多态性与人群感染丙型肝炎病毒的关联性

目的 探索核转录因子κB（NF-κB）基因多态性与人群感染HCV的关联性。方法 本研究共纳入1 679位研究对象（503位吸毒者和1 176位高危血源性暴露者）。通过logistic回归分析人群感染HCV的相关因素,通过TaqMan-MGB探针法对NF-κB1基因rs72696119和REL基因rs13031237位点进行基因分型,并分析其与HCV易感性的相关性。结果 在吸毒人群中,女性吸毒者（OR=0.408,95% CI：0.308～0.767）HCV易感性更低,而静脉注射吸毒（OR=8.817,95% CI：5.577～13.937）以及吸毒时间>5.5年（OR=2.891,95% CI：1.824～4.583）则是感染HCV的危险因素。在高危血源暴露人群中,小学以上文化程度（OR=0.613,95% CI：0.429～0.876）是该高危人群感染HCV的保护因素,而女性（OR=3.431,95% CI：2.360～4.988）则是感染HCV的危险因素。在总人群中,携带NF-κB1 rs72696119 GG基因型的个体更易感染HCV（OR=1.412,95% CI：1.035～1.927）。总人群中的交互作用分析显示,rs72696119与HCV感染途径、性别均不存在交互作用（P>0.05）。结论 在高危人群中,相关的行为因素和NF-κB1基因rs72696119多态性与HCV易感性相关。     

细胞色素氧化酶基因CYP1A1多态性与新疆维吾尔族人群冠心病相关性研究

目的 探讨新疆地区维吾尔(维)族人群细胞色素氧化酶基因CYP1A1多态性与冠心病的关联性。方法 使用实时PCR对293例冠心病患者(病例组)和408名健康体检者(对照组)CYP1A1基因单核苷酸多态性(SNPs:rs4886605, rs12441817, rs4646422, rs1048943)进行基因型鉴定。结果 维族人群病例组和对照组rs4886605的基因型及等位基因分布的差异均有统计学意义(均P<0.05)。病例组rs4886605显性模型(CC vs. CT+TT)基因型频率明显低于对照组。调整混杂因素后logistic回归分析表明, 维族人群rs4886605的CC基因型者患冠心病风险明显低于CT+TT基因型者(总体:OR=0.368, 95%CI:0.185～0.530, P=0.018;男性:OR=0.350, 95%CI:0.235～0.568, P=0.015)。病例组和对照组rs12441817的基因型及等位基因分布差异均有统计学意义(均P<0.05)。病例组的rs12441817显性模型(TT vs. CT+CC)基因型频率明显低于对照组。调整混杂因素后logistic回归分析表明, 维族人群rs12441817的TT基因型者患冠心病风险明显低于CT+CC基因型者(总体:OR=0.253, 95%CI:0.231～0.546, P=0.016;男性:OR=0.241, 95%CI:0.132～0.478, P=0.002)。结论 新疆维族人群CYP1A1基因多态性rs4886605、rs12441817的2个位点与发生冠心病相关。rs4886605的CC基因型、rs12441817的TT基因型可能是该人群发生冠心病的保护因素。     

HLA-DQ基因多态性与HBV感染不同临床结局的关联研究

目的 研究人类白细胞抗原HLA-DQ基因rs2856718和rs9275572两个位点突变是否与HBV感染的不同结局有关。方法 采用问卷调查收集825例研究对象的一般资料,同时收集其外周血,提取DNA,用基质辅助激光解吸电离飞行时间质谱实验平台进行DNA的单核苷酸多态性分型,使用单因素及多因素logistic回归分析方法分析HLA-DQ基因多态性与HBV感染不同结局的关系。结果 携带HLA-DQ基因rs2856718G(524例)和rs9275572A(369例)的个体感染HBV的风险降低(OR=0.702,95%CI:0.558~0.856,P=0.001;OR=0.548,95%CI:0.365~0.847,P=0.005),且HBV自然清除能力强(OR=0.589,95%CI:0.478~0.892,P=8.81×10^-3;OR=0.673,P=0.014,95%CI:0.457~0.860)。携带rs9275572A的个体由慢性乙型肝炎和肝硬化进展到原发性肝细胞癌的风险降低(OR=0.759,95%CI:0.538~0.914,P=0.041)。结论 在中国北方汉族人群中,HLA-DQ的两个SNP位点(rs9275572和rs2856718)与HBV感染后的不同结局有关,rs9275572A和rs2856718G为HBV感染的保护性因素,在HBV自然清除和原发性肝细胞癌的进展中起到保护作用。     

SEC16B基因多态性与体质指数和肥胖关联的Meta分析

目的 探讨SEC16B基因多态性与BMI和肥胖的关联性。方法 系统检索2009-2015年在万方数据库（Wanfangdata）、中国期刊全文数据库（CNKI）、维普中文科技期刊全文数据库（VIP）、PubMed、Embase、Web of Science、NIH GWAS catalog数据库中收录的关于SEC16B基因多态性与BMI和/或肥胖关联性的文献。分别以β值和OR值及其95% CI作为Meta分析效应合并指标。采用Stata 12.0软件对研究结果进行异质性检验和效应值合并计算。结果 最终纳入28篇文献，包括rs10913469相关15篇和rs543874相关13篇。Meta分析显示，在加性遗传模型下，rs10913469-C和rs543874-G与BMI水平具有正向关联，合并β值（95% CI）分别为0.04（0.03～0.05）和0.03（0.02～0.04）；与肥胖罹患风险关联的合并OR值（95% CI）分别为1.11（1.08～1.15）和1.28（1.20～1.36）。按种族、年龄和文献质量进行亚组分析后，rs10913469和rs543874位点与肥胖关联的合并OR值仍有统计学意义。结论 SEC16B基因多态性rs10913469和rs543874位点与不同种族人群BMI及肥胖均有关联，rs10913469-C等位基因和rs543874-G等位基因可增加肥胖罹患风险。     

β-arrestin2基因多态性与湖南省汉族海洛因成瘾者美沙酮维持治疗反应的关联分析

目的 研究β-arrestin2(ARRB2)基因的3个单核苷酸多态性(SNP)位点rs3786047、rs1045280、rs2036657在湖南省汉族海洛因成瘾者中的分布及其与美沙酮维持治疗反应的相关性。方法 从湖南省美沙酮维持治疗门诊中随机抽取4个门诊,以汉族美沙酮维持治疗者作为研究对象,收集研究对象的一般社会经济学特征、相关吸毒史和美沙酮治疗史资料,测定ARRB2基因多态性位点的基因型以分析SNP位点与治疗反应的关系。结果 ARRB2基因rs3786047、rs1045280、rs2036657 SNP位点在不同治疗反应组基因型分布频率符合Hardy-Weinberg遗传平衡。在治疗反应好与差两组间,rs3786047(χ²=0.4862,P=0.784)、rs1045280(χ²=1.5919,P=0.451)、rs2036657(χ²=1.0615,P=0.588)的基因型频率分布和等位基因频率分布差异无统计学意义。结论 湖南省汉族美沙酮维持治疗人群中尚未发现ARRB2基因单核苷酸多态位点rs3786047、rs1045280、rs2036657与治疗反应有关联关系。     

张家口地区白细胞介素-28B基因单核苷酸多态性与肝细胞癌的相关性研究

目的 探讨白细胞介素-28B（IL-28B）基因rs12979860位点单核苷酸多态性与张家口居民肝细胞癌遗传易感性的关联及与环境因素间的交互作用。方法 采用以医院为基础1[DK]∶1配比病例对照研究方法,选取肝细胞癌患者218例作为观察组,同期健康体检者218例作为对照组,应用改良多重高温连接酶检测反应技术检测两组IL-28B基因rs12979860位点单核苷酸多态性。采用二分类logistic回归模型分析IL-28B基因rs12979860位点单核苷酸多态性与肝细胞癌遗传易感性的关系,并探究rs12979860位点单核苷酸多态性与环境因素的交互作用对肝细胞癌发病影响。结果 对照组与观察组间IL-28B基因rs12979860位点基因型分布差异无统计学意义（P>0.05）。IL-28B基因rs12979860位点T等位基因可增加肝细胞癌发病风险（P<0.05）。分层分析发现,在饮酒、乙型肝炎病毒（HBV）及丙型肝炎病毒（HCV）感染人群中rs12979860位点TT基因型相比TC+CC基因型,肝细胞癌发病风险升高,差异具有统计学意义（P<0.05）。交互作用分析示,IL-28B基因rs12979860位点单核苷酸多态性与饮酒、HBV及HCV感染均存在正交互作用。结论 在张家口地区,IL-28B基因rs12979860位点单核苷酸多态性与肝细胞癌遗传易感性明显相关,并与饮酒、HBV及HCV感染存在正交互作用,可增加肝细胞癌发病风险。     

CYP24A1基因多态性与绝经后女性乳腺癌的易感性研究

目的 探究CYP24A1基因多态性与绝经后女性乳腺癌风险关联。方法 采用以人群为基础的病例对照研究方法,在江苏省无锡市选取绝经后女性1 134人（589例乳腺癌患者和545例非乳腺癌患者）。采取Sequenom MassARRAY平台对CYP24A1单核苷酸多态性位点（rs2209314、rs2585428、rs2762941、rs3787555、rs4909959、rs912505和rs927650）进行分型,通过logistic回归分析CYP24A1多态性与乳腺癌的易感性,并采用广义多因子降维方法分析位点-位点之间的交互作用。结果 CYP24A1基因的rs2209314、rs2585428、rs2762941、rs3787555、rs4909959、rs912505和rs927650在共显性、显性、隐性和相加模型下均未发现与乳腺癌存在统计学关联。在腰围<80 cm的人群中,rs2585428能降低乳腺癌风险（OR=0.64,95% CI：0.42～0.96）,rs3787555也表现出相似关联（OR=0.58,95% CI：0.38～0.87）。同时rs2585428、rs3787555和rs4909959与腰围在乳腺癌发病风险存在交互作用。rs2209314、rs3787555和rs912505之间可能存在位点-位点之间的交互作用（P=0.054 7）。结论 在绝经后人群中,rs2585428和rs3787555与乳腺癌的易感性存在关联。     

白细胞介素-28B和平衡性核苷转运载体1基因多态性与HIV/HCV合并感染者HCV自发清除的关系研究

目的 分析湖南省HIV/HCV合并感染者的白细胞介素-28B(IL-28B)和平衡性核苷转运载体1(ENT1)基因多态性与HCV自发清除的关系。方法 对湖南省107例HIV/HCV合并感染者的IL-28B和ENT1基因位点(rs12980275、rs12979860、rs8099917和rs760370)进行分型, 比较其在慢性肝炎组和自发清除组的基因多态性分布。结果 在HIV/HCV合并感染者中, IL-28B基因rs12980275、rs12979860和rs8099917位点的主要基因型分别为AA、CC和TT型, 均占84.1%。3个位点高度连锁不平衡(r²>0.94), 慢性肝炎组和自发清除组基因型分布差异有统计学意义(P<0.05), 携带IL-28B主要基因型的感染者更易发生HCV自发清除。ENT1基因的rs760370位点基因型分布在两组间的差异无统计学意义(P>0.05)。结论 IL-28B基因AA、CC和TT型与HCV自发清除有关。     

Trends in predictors of death due to HIV-related causes among persons living with AIDS in New York City: 1993–2001

To examine trends in predictors of HIV-related mortality among cohorts of persons living with AIDS (PLWA) in New York City (NYC), nine calendar year-specific cohorts of PLWA were created from 1993 to 2001. Cohorts were defined as persons who had been alive at any time during that year and had been diagnosed with AIDS before the end of that year. Predictors of death because of HIV-related causes of death were assessed by examinnng year-specific, stratified death rates per 1,000 PLWA and adjusted relative risks (RRs) from proportional hazards models. We conducted an analysis of AIDS surveillance data PLWA in NYC between 1993 and 2001. Univariate and multivariate Cox proportional hazards models were constructed for each calendar year cohort to evaluate trends in the RR of HIV-related death over the subsequent 5 years, adjusting for sex, reace/ethnicity, age, transmission risk borough of residence, category of AIDS diagnosis [opportunistic illness (OI) or CD4 count <200 cells/μL], time since AIDS diagnosis, and CD4 count at time of AIDS diagnosis. Death rates due to all causes and HIV-related causes declined substantially during 1993–1997 and then stabilized in all subgroups of PLWA between 1998 and 2001. Beginning in 1995, differences in survival emerged in some subgroups, such that by 2001 (1) injecting drug users (IDUs) had poorer survival compared with men who have sex with men (MSM) [RR₂₀₀₁=2.1, 95% confidence intervals (95% CI)=1.8–2.4]; (2) black and Hispanic PLWA had a significantly higher risk of death than white PLWA (RR₂₀₀₁=1.4, 95% CI=1.2–1.6, RR₂₀₀₁=1.2, 95% CI=1.1–1.4, respectively, and (3) PLWA aged 60 and above had poorer survival compared with younger persons (RR₂₀₀₁=2.4, 95% CI=1.9–3.0), after adjustment for other factors. The observed disparities that began to emerge in 1995 may be attributable to differential effects of, access to, or usage of highly active antiretroviral therapy (HAART). More targeted studies are needed to determine why such disparities have emerged.     

A vulnerable population in a time of crisis: Drug users and the attacks on the World Trade Center

In this article, we present preliminary findings from a qualitative study focused on the impact of the World Trade Center attacks on New York City residents who are current or former users of heroin, crack, and other forms of cocaine. In it, we present data describing their responses to and feelings about the attacks, changes in drug use after the attacks, and factors affecting changes in use. Our analysis is based on 57 open-ended interviews conducted between October 2001 and February 2002. The majority of study participants reported that the attacks had a significant emotional impact on them, causing anxiety, sadness, and anger. Several described practical impacts as well, including significant reductions in income. On September 11th and the weeks and months that followed, several participants who had been actively using did increase their use of heroin, crack, and/or other forms of cocaine. Reductions in use were, however, as common over time as were increases. There was some relapse among former users, but this was limited to those who had stopped using drugs within the 6 months immediately preceding the attacks. A diverse set of factors interacted to control use. For some participants, these factors were internal, relating to their individual motivations and drug use experiences. Other participants were essentially forced to limit use by marked reductions in income. For others, access to health and social service professionals, as well as drug treatment, proved to be key. Department of Family Medicine and Community Health at Montefiore Medical Center     

Computer and internet use among urban African Americans with type 2 diabetes

Previous studies have identified a “digital divide” between African Americans and whites, with African Americans having substantially lower rates of Internet use. However, use of the Internet to access health information has not been sufficiently evaluated in this population. Therefore, we conducted a telephone survey to determine the prevalence of computer and Internet use among 457 African American adults with type 2 diabetes. Participants were 78% female, with a mean age of 57±11 years, and about one-third had a yearly income ≦$7,500. Forty percent of the participants reported having a computer at home and 46% reported knowing how to use a computer. Most participants (58%) reported that they had, at some point, used a computer, and of those, 40% reported that they used the computer to find health information. In a stratified analysis, participants with lower education levels (<high school) were less likely to have a computer; older participants, men, and individuals with lower education levels were less likely to know how to use a computer and to use it to search for health information (all P<.05). Nonetheless, of the participants who did not know how to use a computer, 66% reported that they would be willing to learn. In addition, 82% reported that they had friends or family in the neighborhood who would let them use a computer. Furthermore, 89% of participants reported that they would use a computer program to manage their diabetes if it were offered free of charge. These data show promise for the willingness of this under-served population to use computers and access health information using the Internet. New programs are needed to explore Internet-based interventions to improve self-management and diabetes care among African Americans.     

Antimicrobial antibodies in Danish slaughterhouse workers and greenhouse workers

Summary As a consequence of contact with animals and animal products slaughterhouse workers might be at risk of infection with pathogenic microorganisms. This hypothesis has been supported by some earlier studies. In this study 217 slaughtermen and a control group of 113 greenhouse workers were investigated for the prevalence of serum antibodies to Toxoplasma gondii, Campylobacter jejuni (IgA and IgG), Yersinia enterocolitica types 3 and 9, Yersinia pseudotuberculosis types I, II, III, IV, and V, Salmonella typhi, Salmonella paratyphi, Salmonella enteritidis, Salmonella typhimurium, and Borrelia burgdorferi. No significant differences were found concerning either frequency of positive tests or magnitude of titers. The prevalence of toxoplasma antibodies was remarkably high in both groups.     

Clinical and laboratory evidence of the importance of the tick D. marginatus as a vector of B. burgdorferi in some areas of sporadic Lyme disease in Bulgaria

56 adult ticks D. marginatus and 38 adult ticks H. punctata were sampled by the flagging method, transferred to the laboratory, dissected and tested for infection with Lyme disease spirochetes. 3 (7.9%) of the adult H. punctata and 2 (3.57%) of the adult D. marginatus were infected with B. burgdorferi (Bb). This report also presents the case of a patient, who developed Lyme disease symptoms after he had been bitten by a D. marginatus tick. The clinical diagnosis was confirmed by serological testing and by a biopsy, taken from the patient's skin lesion. The skin biopsy was examined under an electron microscope and Bb was found in the sections of the deeper strata of the dermis in two structural forms: (a) cylindrical bodies (protoplasm cylinder) with circular ends covered with a three-layered membrane; (b) granules, situated among the collagenous fibres either closely adhered to them or covered with a membrane. The result of the study demonstrates that in single cases in some ecosystems, ticks D. marginatus might be implicated in Bb transmission to humans as secondary vectors.     

Absorption,metabolism and elimination of N,N-dimethylformamide in humans

Summary Excretion of N,N-dimethylformamide (DMF) and DMF metabolites N-hydroxymethyl-N-methylformamide (MF), N-hydroxymethyl-formamide (F) and N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) has been monitored in the urine of volunteers during and after their 8-h exposure to DMF vapour at a concentration of 10, 30 and 60 mg · m^–3. The pulmonary ventilation in these experiments was typically about 101 · min^–1 and the retention in the respiratory tract was 90%. After exposure to 30 mg DMF · m^–3, the yield of compound determined in the urine represented 0.3% (DMF), 22.3% (MF), 13.2% (F) and 13.4% (AMCC) of the dose absorbed via the respiratory tract. The excretion curves of the particular compounds attained their maximum 6–8h (DMF), 6–8h (MF), 8–14h (F) and 24–34h (AMCC) after the start of the exposure. The half-times of excretion were approximately 2, 4, 7 and 23 h respectively. In contrast to slow elimination of AMCC after exposure to DMF, AMCC was eliminated rapidly after AMCC intake. This discrepancy could be explained by rate-limiting reversible protein binding of a reactive metabolic intermediate of DMF, possibly methylisocyanate.     

Biological monitoring of workers exposed to<Emphasis Type="Italic"> N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylformamide in synthetic leather manufacturing factories in Korea

Objectives To investigate the relationship between N,N-dimethylformamide (DMF) exposure and excretion of urinary N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) and N-methylformamide (NMF) in workers at synthetic leather manufacturing factories in Korea, for the first time.Methods One-hundred forty-four male workers at nine synthetic leather manufacturing factories were surveyed. Exposure to DMF was evaluated through breathing zone air sampling followed by analysis via a gas chromatograph equipped with a flame ionization detector (GC-FID). The levels of NMF and AMCC were determined by a GC with a flame thermionic detector (GC-FTD). Urine samples were collected at the end of the workshift.Results and Conclusions Geometric mean of workplace air DMF and urinary NMF was 8.8 ppm and 47.5 mg/l, respectively, and the level of DMF and NMF was significantly correlated. The biological exposure limit for NMF (15 mg/ml) was exceeded in 89.5% of urine samples, and 37.9% of air samples exceeded the environmental DMF exposure limit (10 ppm), indicating a serious health risk to the employees of the synthetic leather industry in Korea. Exposure to 10 ppm DMF in the workplace air corresponded to a urinary NMF concentration of 53.4 mg/l. Alcohol intake the day before urine was sampled influenced NMF excretion into urine (40.5 mg/l NMF for the no-alcohol group and 94.6 mg/l for the group consuming more than 63.0 g alcohol/day). We could not find a significant relationship between air DMF and urinary AMCC concentration. Exposure to 10 ppm DMF corresponded to an AMCC concentration of 8.0 mg/l in the urine samples collected on the same day as the air was sampled.     

我国几种非嗜肺军团菌感染的血清流行病学研究

本文报告了1986年对我国五个地区994名健康成人、373名儿童和100例肺炎病人进行三种军团菌抗体检测的结果。健康成人抗体阳性率(≥1:16)Lm为9.26%,Ld为9.05%,Lg为3.32%。儿童Lm为5.36%,Ld为2.14%,Lg为3.75%。肺炎病人抗体阳性率以Ld最高(44%),Lm次之(23%),Lg均阴性。提示我国南方和北方地区人群中均存在这三种军团菌感染的可能性,应予以注意。     

Percutaneous absorption of N,N-dimethylformamide in humans

Summary Skin penetration fo N,N-dimethylformamide (DMF) liquid or vapour was studied in volunteers. Exposure to liquid DMF was performed in two ways: in a dipping experiment, one hand was dipped up to the wrist in DMF for 2–20 min, while in a patch experiment, 2 mmol DMF was applied to the skin and allowed to be absorbed completely. The period of exposure to DMF vapour (50 mg · m^–3) was 4 h. The DMF metabolites N-hydroxymethyl-N-methylformamide (MF), N-hydroxymethylformamide (F), and N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) were monitored in the urine. Liquid DMF was absorbed through the skin at a rate of 9.4 mg · cm^–2 · h^–1. Percutaneous absorption of DMF vapour depended strongly on ambient temperature and humidity and accounted for 13%–36% of totally excreted MF. The results suggest that skin absorption of liquid DMF is likely to contribute to occupational exposure substantially more than penetration of DMF vapour. The yield of metabolites after transdermal DMF absorption was only half of that seen after pulmonary absorption. Elimination of MF and F but not that of AMCC was delayed, which supports the contention that AMCC should be used instead of MF as the most suitable biomarker of DMF in cases where percutaneous intake can occur.     

Effects of increasing syringe availability on syringe-exchange use and HIV risk: Connecticut, 1990–2001

Syringe-exchange programs (SEPs) in Connecticut operate with caps on the number of syringes exchanged per visit. We investigated the effects of legislation increasing the cap on drug injectors' access to clean syringes through the SEPs in New Haven and Hartford. The mixed design of this study included longitudinal and crosssectional data from individuals and ecological data from program operations. Five parameters—syringe return rate, syringes per visit to the SEP, syringe reuse rate, syringe human immunodeficiency virus (HIV) prevalence, and syringe sharing—were monitored through syringe tracking and testing of SEP syringes and by interviewing injectors. Two increases in the cap—from 5 to 10 and then from 10 to 30—had little effect on the five parameters that measured injectors' access to clean syringes. In contrast, access to clean syringes increased when the New Haven SEP first began operations, when syringes first became available at pharmacies in Hartford, and when the agency running the Hartford SEP changed. Legislation providing piecemeal increases in the cap may not, by themselves, be sufficient to increase injectors' access to clean syringes and decrease the risk of human immunodeficiency virus transmission in this population.