广东省2013-2014年食源性疾病主动监测的病原学特征分析

目的 了解广东省腹泻病例中沙门菌、志贺菌、副溶血弧菌和4种致泻性大肠埃希菌［肠产毒性大肠埃希菌（ETEC）、肠致病性大肠埃希菌（EPEC）、产志贺毒素大肠埃希菌（STEC）、肠侵袭性大肠埃希菌（EIEC）］的感染情况及其血清型别、耐药变化和分子特征。方法 对2013-2014年广东省食源性疾病主动监测检出的沙门菌、志贺菌、副溶血弧菌和4种致泻性大肠埃希菌菌株进行血清分型、药物敏感试验和PFGE分型。结果 2013-2014年检测粪便标本57 834份,分离到3 372株致病菌,检出率为5.83%;沙门菌的检出阳性率最高,其次是副溶血弧菌、致泻性大肠埃希菌、志贺菌。3 213株沙门菌分为143种血清型,最常见的血清型为鼠伤寒、4,5,12：i：-、肠炎、斯坦利和德尔卑沙门菌。沙门菌对头孢类和氟喹诺酮类药物均较敏感;不同血清型沙门菌对抗生素的耐药率有明显差异,10种最常见血清型中,肠炎沙门菌对头孢类药物的耐药率最高,德尔卑沙门菌对环丙沙星的耐药率最高。2 289株各血清型沙门菌的PFGE型别分布多样,表现出较大的指纹图谱多态性。85株副溶血弧菌分为10种血清型,最主要的血清型为O3：K6（61.18%）,其次是O4：K8（10.59%）;tdh携带率高（81.18%）,trh携带率较低（7.06%）,有10株菌（11.76%）不携带该两种毒力基因;副溶血弧菌对亚胺培南、萘啶酸、复方新诺明、氯霉素、四环素的敏感率均>95%。13株志贺菌分别为宋内志贺菌9株、福氏志贺菌3株、鲍氏志贺菌1株;对头孢他啶、环丙沙星、氯霉素较敏感（76.92%）。检出的86株致泻性大肠埃希菌中ETEC 29株（33.72%）,EPEC 27株（31.39%）,STEC 27株（31.39%）,EIEC 3株（3.48%）。结论 2013-2014年广东省食源性疾病主动监测中沙门菌检出率最高（5.57%）,其次是副溶血弧菌、致泻性大肠埃希菌、志贺菌;沙门菌、副溶血弧菌和志贺菌对头孢类和氟喹诺酮类药物敏感;沙门菌感染中仅发现聚集性病例,但未监测到暴发。     

广东省2018-2022年侵袭性非伤寒沙门菌病原学特征分析

目的 了解2018-2022年广东省侵袭性非伤寒沙门菌（iNTS）的血清型分布、耐药性以及分子流行情况,为沙门菌侵袭性感染的防治提供科学依据。方法 对2018-2022年广东省分离自血液和粪便样本的沙门菌进行血清学鉴定、药敏试验、多位点序列分型（MLST）和全基因组测序。同时利用微生物基因注释系统对测序结果开展耐药基因与毒力因子注释。结果 136株iNTS分为25种血清型,肠炎沙门菌占38.24%（52/136）。以鼠伤寒变种沙门菌作为对照计算其余iNTS血清型的OR值,奥雷宁堡、里森和波摩那3种沙门菌血清型的OR值较高,分别为423.50、352.92和211.75。iNTS耐药率在0.74%~66.91%之间,普遍低于非iNTS株（3.90%~77.21%）。iNTS耐药以氨苄西林和四环素为主,耐药率分别为66.91%（91/136）和50.00%（68/136）,而对环丙沙星（5.88%,8/136）、头孢他啶（5.88%,8/136）、庆大霉素（5.13%,7/136）和头孢西丁（0.74%,1/136）耐药率较低。iNTS携带多种耐药基因与毒力因子,但尚未发现共同毒力因子分布特征。MLST聚类分析显示,iNTS分为26种序列型别,ST11型占38.24%（52/136）。结论 2018-2022年广东省iNTS以肠炎沙门菌为主,其中奥雷宁堡、里森和波摩那3种血清型可能与更高的侵袭性感染风险有关。iNTS对临床一线治疗药物（头孢类和氟喹诺酮类抗生素）敏感,序列呈现高度多样性且具有明确的系统发育分支,以ST11型为本地优势克隆群。     

河南省2009-2011年伤寒副伤寒沙门菌分子分型与耐药研究

目的 分析2009-2011年河南省伤寒副伤寒沙门菌临床分离株耐药状况与PFGE分型特征。方法 根据PulseNet公布的伤寒副伤寒沙门菌PFGE分型操作规程与美国临床实验室标准协会(CLSI)沙门菌K-B法药敏测试方案,对2009-2011年分离自河南省监测哨点医院78株伤寒副伤寒沙门菌进行抗生素药敏测试与PFGE分子分型。结果 78株伤寒副伤寒沙门菌对8类13种抗生素均有不同程度的耐药,62株为多重耐药菌株(79.5%),其中耐2～3种4株(5.1%),耐5～8种41株(52.6%),耐9～10种14株(17.9%),耐11～12种3株(3.8%);菌株对头孢类、喹诺酮类等5类抗生素耐药率总体呈上升趋势。经XbaⅠ酶切与PFGE后,获得14种带型,每种带型包含菌株数1～47株不等,相似度为66.03%～100.00%。结论 2000-2011年河南省临床分离的伤寒副伤寒沙门菌耐药状况普遍比较严重,PFGE带型呈现多样性的同时又具有较显著的优势带型特点,部分带型与其对应的耐药谱具有一定的关联性和聚集性。     

河南省2011-2015年非伤寒沙门菌病原学与耐药监测

目的 检测与分析2011-2015年自河南省腹泻多病原监测系统腹泻病例粪便中分离的1 351株非伤寒沙门菌血清型别及耐药表型。方法 采集河南省5家监测哨点医院肠道门诊及住院病例腹泻样本,进行沙门菌分离培养、生化鉴定与血清学分型;根据美国临床与实验室标准协会（CLSI）沙门菌K-B法药敏测试方案,对其进行8类12种抗生素的药敏测试与表型分析。结果 1 351株非伤寒沙门菌感染病例男女比例1.5：1（811：540）,以低龄儿童和青壮年为主;分离时间多集中于每年的5-10月,具有较典型的春夏季节特征。1 351株非伤寒沙门菌共分为58个血清型,以肠炎（S.enteritidis）、鼠伤寒（S.typhimurium）、阿贡那（S.agona）等7种血清型为主。药敏结果显示,其对广谱合成类青霉素氨苄西林（AMP）、三代头孢类抗生素头孢他啶（CAZ）、头孢噻肟（CTX）、四代头孢类抗生素头孢吡肟（FEP）、三代氟喹诺酮类抗生素环丙沙星（CIP）、氨基糖苷类抗生素庆大霉素（GEN）等12种抗生素均存在不同程度的耐药与多重耐药性。结论 河南省感染人群的非伤寒沙门菌血清型别众多;部分菌株对临床常用的12类抗生素具有较高的耐药率且多重耐药问题日益严重。     

北京市2010-2020年多重耐药肯塔基沙门菌流行特征分析

目的 了解北京市肯塔基沙门菌临床分离株的流行情况、耐药水平及分子特征。方法 对2010-2020年分离的22株肯塔基沙门菌采用微量肉汤稀释法进行抗生素药物敏感性检测;全基因组测序进行多位点序列分型、基因组岛和耐药基因识别。采用PFGE分析菌株的分子流行病学特征。结果 22株菌对8~22种抗生素耐药,尤其是对环丙沙星、阿奇霉素和头孢菌素类等都表现为超高水平的多重耐药。21株菌超广谱β-内酰胺酶表型阳性。全基因组序列分析显示,22株肯塔基沙门菌均为ST198,携带SGI1-K基因组岛。所有菌株均有耐药基因tetA、sul1、qacE,喹诺酮耐药决定区gyrA基因存在2个突变位点（S83F、D87 N）、parC基因存在3个突变位点（T57S、S80I、T255S）。β-内酰胺类相关耐药基因（blaCTX-M-55、blaCTX-M-14b、blaTEM-141、blaTEM-206、blaTEM-209、blaTEM-214、blaTEM-1B）、氨基糖甙类耐药相关基因[aac（3）-Id、aac（3）-IId、aac（6''）-Iaa、aadA7、aadA17、aph（3''）-Ia、aph（3''）-Ib、aph（6）-Id、rmtB]以及floR、dfrA14、mphA和qnrS1等基因在不同年代菌株间存在明显差异。PFGE图谱分析显示,22株菌株之间相似性>85%,与全球广泛传播的ST198-X1流行株高度同源,在传播扩散过程中,耐药谱和PFGE图谱都发生了变化,分为两大聚类簇。结论 北京市流行的肯塔基沙门菌为多重耐药的ST198-X1-SGI-1K国际流行株,自2016年以来保持低水平流行,引起散发感染病例和聚集性腹泻事件。对氟喹诺酮类、ESBL和阿奇霉素等耐药严重,应加强多重耐药肯塔基沙门菌的监测。     

2020—2022年上海市浦东新区市售食品中沙门菌耐药特征研究

【目的】了解市售食品中沙门菌污染情况、血清型分布以及耐药情况。【方法】对2020—2022年浦东新区抽检的市售食品进行沙门菌检测,并对所获菌株开展血清学分型和15种抗生素的微量肉汤法药敏试验。【结果】2497件食品共检出118株沙门菌,总检出率为4.7%,优势检出类别依次为禽肉类、畜肉类和水产类。118株沙门菌可分为24种血清型,肠炎沙门菌(26.4%)、鼠伤寒沙门菌(16.2%)和德尔卑沙门菌(14.4%)是主要优势型别。沙门菌对氨苄西林耐药率最高,达63.6%,其次是四环素、氯霉素、复方新诺明和萘啶酸。3种优势血清型中鼠伤寒沙门菌多重耐药率最高为89.5%,其次是德尔卑沙门菌(70.6%)和肠炎沙门菌(61.3%)。【结论】市售食品中,畜、禽肉与水产品沙门菌污染严重,血清型别多样化,畜肉以鼠伤寒、德尔卑沙门菌为主,禽肉以肠炎沙门菌为主;耐药谱广泛,多重耐药率高,不同于畜肉、水产类分离株,禽肉源菌株对氨苄西林、萘啶酸和多黏菌素的耐受较高,具有一定的食品安全隐患。     

江苏省2012-2015年伤寒/副伤寒沙门菌耐药及分子分型研究

目的 回顾性分析2012-2015年江苏省伤寒/副伤寒沙门菌的耐药表型和分子分型特征。方法 采集江苏省伤寒/副伤寒监测病例的血液和粪便标本,分离培养伤寒/副伤寒沙门菌后进行生化鉴定和血清分型;采用Kirby-Bauer纸片法检测菌株对抗菌药物的敏感性;应用PFGE技术对伤寒和甲型副伤寒沙门菌进行分子分型。结果 134株伤寒沙门菌和甲型副伤寒沙门菌对萘啶酸的耐药率最高,分别为61.2%和86.7%,其余抗生素的耐药率均低于15.0%。伤寒和甲型副伤寒沙门菌中只耐1种抗生素的菌株最多,多重耐药菌在伤寒沙门菌中占2.6%,而在甲型副伤寒沙门菌中占13.3%。2015年伤寒沙门菌的全敏感菌株构成比较2012年增加了44.3%,同年副伤寒沙门菌中出现了耐5种和6种抗生素的多重耐药株。甲型副伤寒沙门菌可分为8种PFGE型别,多重耐药株与其他菌株条带相似性低,不同型别与耐药谱有对应关系;伤寒沙门菌可分为68种PFGE型别,不同型别间变异度较大,与耐药谱无对应关系。结论 2012-2015年江苏省伤寒/副伤寒沙门菌对抗生素的耐药性总体随时间降低,耐药种类数有所增加。伤寒沙门菌株PFGE带型呈现多样性,无耐药谱对应性;而甲型副伤寒菌株PFGE带型较少,有耐药谱对应性。需要加强重点地区重点型别菌株的监测。     

某院耐亚胺培南鲍曼不动杆菌耐药基因及临床特征

目的 分析某院临床分离的耐亚胺培南鲍曼不动杆菌（IRAB）耐药基因携带情况，为医院感染防控和指导临床治疗提供实验室依据。方法 采用聚合酶链反应（PCR）方法检测该院临床分离的26株IRAB碳青霉烯类耐药基因（blaIMP、blaKPC、blaNDM-1、blaOXA-23、blaOXA-50、blaOXA-51、blaOXA-58）、氨基糖苷类耐药基因［ant（3"）-Ⅰ、aac（6''）-Ⅰ、armA］和消毒剂耐药基因qacE△1携带情况。结果 26株IRAB均携带碳青霉烯酶基因OXA-23和OXA-51，检出率为100%，未检出其他碳青霉烯类耐药基因。氨基糖苷类耐药基因ant（3"）-Ⅰ、aac（6''）-Ⅰ和armA检出率均为96.15%，消毒剂耐药基因qacE△1基因携带率为65.38%。临床分离IRAB菌株92.31%来源于患者的痰液。结论 该院临床分离IRAB多数携带相同的碳青霉烯类耐药基因和氨基糖苷类耐药基因，需加强医院感染防控措施。     

广东省2014年食源性副溶血弧菌病原学特征分析

目的 了解2014年广东省食源性副溶血弧菌分离株的血清型别、抗生素敏感性、毒力基因携带情况以及分子分型特征。方法 对60株副溶血弧菌分离株进行血清分型、抗生素敏感性试验及检测耐热直接溶血素基因(tdh)和耐热相关溶血素基因(trh),并进行脉冲场凝胶电泳(PFGE)和多位点序列(MLST)分型。结果 60株分离株可分为13个血清型,主要型别为O3:K6、O4:K8、O1:K36和O4:KUT;对氨苄西林、磺胺复合物和头孢噻吩的耐药率分别为100.0%、43.3%和28.3%,有56.7%(34/60)的菌株对2类及以上抗生素同时耐药,2株菌对3类抗生素同时耐受。毒力基因PCR检测发现,有63.3%(38/60)的分离株为tdh⁺trh^-菌株,仅1株为tdh⁺trh+菌株。分子分型显示,经NotⅠ酶消化后,60株副溶血弧菌可产生48个PFGE谱型,可分为3个聚类(Cluster A、B和C)。其中Cluster B的菌株主要分离自食源性疾病监测中心散发病例,血清型以O3:K6为主,PFGE谱型的相似度在62.6%～100.0%;Cluster C主要是由4株O4:K8型菌株组成,谱型相似度为56.7%～62.5%。60株菌MLST分型可分为26个ST型,其中33株菌为ST-3型,主要是O3:K6和O1:K36菌株;4株O4:K8菌株聚集成另一个不同于ST-3型的相对优势的菌群。结论 2014年广东省副溶血弧菌菌型多样性可能是疾病高发的原因之一,O4:K8型菌株的分子特征与其他优势血清型别明显不同,应高度警惕该型菌株引起暴发的可能。     

广东省2007-2016年人源沙门菌流行现状及病原学特征

目的 了解广东省人源沙门菌1,4,[5],12：i：-的流行现状、耐药性与分子特征。方法 对2007－2016年广东省沙门菌腹泻病例监测检出的人源沙门菌1,4,[5],12：i：-进行药物敏感试验、PCR检测和PFGE分型。结果 2007－2016年广东省共检出人源沙门菌1,4,[5],12：i：-2 960株,检出率逐年增多,至2015年成为广东省人源沙门菌中最主要的血清型。病例中男女性别比为1.58∶1,发病年龄以婴幼儿为主。沙门菌1,4,[5],12：i：-除对亚胺培南100%敏感外,对其他17种抗生素均有不同程度的耐药。2011－2016年对头孢他啶、头孢噻肟和环丙沙星的耐药率呈上升趋势。多重耐药现象严重,具有ASSuT多重耐药的有70.62%（435/616）,具有ACSuGSTTm多重耐药的有27.11%（167/616）。第Ⅱ相鞭毛蛋白不表达主要（75.53%）是缺失fljA、fljB和hin基因,但保留了iroB、STM2740、STM2757基因,共有8种不同的缺失方式。2 347株菌有934种PFGE谱型别,表现出较大的指纹图谱多态性,最主要的优势PFGE谱型为JPXX01.GD0226型（97株菌,4.13%）。168株沙门菌1,4,[5],12：i：-的PFGE图谱与鼠伤寒沙门菌PFGE图谱一致。结论 沙门菌1,4,[5],12：i：-已成为广东省人源沙门菌中最主要的血清型,且多重耐药现象严重,第Ⅱ相鞭毛蛋白不表达主要由缺失fljA、fljB和hin基因引起,其PFGE型别多样,呈遗传多态性。     

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.     

The impact of needle-exchange programs on the spread of HIV among injection drug users: A simulation study

Objective. To determine the impact of the implementation of a needle-exchange program (NEP) on the spread of human immunodeficiency virus (HIV) in an injection drug user (IDU) community. We conducted a Monte Carlo simulation study of a theoretical population of 10,000 IDUs. The population was followed monthly from 1984 to 2000. HIV was assumed to be transmitted only by needle sharing. The NEP was introduced in 1989 and evaluated over a period of 11 years. The impacts of the proportion of the population attending the NEP, the risk level of IDUs attending the NEP, the reduction in needle-sharing frequency, and the number of new needle-sharing partners acquired at the NEP on prevalence and incidence of HIV were determined. Increasing the proportion of the population who always attend the NEP and eliminating needle-sharing incidents among IDUs who always attended the NEP were the most effective ways of reducing the spread of HIV. Attracting high-risk users instead of lower risk users to the NEP also reduced the spread of HIV, but to a lesser extent. NEPs are effective at reducing the spread of HIV; even under the worst case scenario of low risk users more likely to attend the NEP, one additional partner per month as a result of attending the NEP, and poor NEP attendance, the estimated prevalence was still less than that from the scenario without an NEP. Under our model, NEPs were shown to reduce the spread of HIV significantly. Efforts should be focused on getting as many IDUs as possible to become regular NEP attenders and stop sharing needles rather than partially reducing the frequency of sharing by a larger number of IDUs.     

Re-assessment of the influence of polymorphisms of phase-II metabolic enzymes on renal cell cancer risk of trichloroethylene-exposed workers

Problem Individual differences in susceptibility to trichloroethylene-induced nephrocarcinogenicity may be conferred by genetic polymorphisms of glutathione S-transferases (GST), because enzymes of this group are pivotal for the metabolic activation of trichloroethylene. Because of a potential involvement of N-acetylation in the detoxication of reactive trichloroethylene metabolite(s) to N-acetyl-cysteine derivatives, polymorphisms of the NAT2 gene may also be relevant. Methods The primary collective used for a re-investigation of these questions was that of a hospital-based case-control study by Brüning et al. (Am J Ind Med 43:274–285, 2003) of 134 renal cell cancer cases (20 cases exposed to trichloroethylene) and 401 matched controls. Genetic polymorphisms of GSTT1, GSTM1, GSTP1 and NAT2 were studied. Additional control collectives of non-diseased persons were used for comparison of allele frequencies. Results No genetic influences on the development of renal cancer due to trichloroethylene were apparent, related to the deletion polymorphisms of GSTT1 and GSTM1, as well as to the NAT2 rapid/slow acetylator states. However, renal cell cancer cases displayed a somewhat higher proportion of the homozygous GSTP1 313A wild type (GSTP1*A), although this was not statistically significant (χ² test: P = 0.1071, when using only the original controls of Brüning et al. (2003); P = 0.0781 with inclusion of the additional controls). Conclusion The re-investigation does not confirm the working hypothesis of an influence of the deletion polymorphisms of the glutathione S-transferases GSTT1 and GSTM1 on renal cell cancer development due to high occupational exposures to trichloroethylene.     

Screening of the municipal water system of La Plata, Argentina, for human intestinal parasites

The La Plata River, though severely contaminated by intestinal parasites through the discharge of tons of crude fecal material from a main sewage channel, nevertheless provides drinking water to two-thirds of La Plata, Argentina, after conventional purification at a processing plant. With intestinal parasitosis being endemic here, we investigated the importance of this water in transmitting such pathogens to the city's populace by means of standard methodology for sample acquisition and processing involving filter-concentration of waterborne particulates. Of 14 tap-water samples collected from the distribution network, 12 pertained to four zones (A-D) within the city center; while the remaining 2 were obtained near the processing plant, 15 kilometers outside the city. Although parasites were found within the samples derived from the four urban zones, none were detected in the specimens obtained near the plant. The four downtown areas differed from each other as to the quantity and nature of the parasites present in their water: whereas zones A and B registered similar lower levels of contaminants, C and D exhibited higher values significantly different from the former two and from each other. Given an average parasite count/l citywide of 0.38 and a probability of encountering a parasite within 11 of water of 0.32, the municipal network is seen to contribute to the transmission of intestinal parasites. A routine system of water-quality control is therefore needed throughout the city along with the establishment of infrastructures for locating and eliminating peripheral sources of contamination.     

Seroepidemiology of rickettsial infections in Morocco

The prevalence of antibodies reactive withRickettsia conorii, Rickettsia typhi, Coxiella burnetii andEhrlichia chaffeensis was investigated using indirect immunofluorescence (IFA) test on human sera obtained from 300 blood donors in Casablanca and 126 sera obtained from clinical laboratories in Fez. In sera from Casablanca, antibodies reactive at titers >=1: 32 were found againstR. conorii (7%), andR. typhi (1.7%), but not againstE. chaffeensis. In the sera from Fez, antibodies were also detected againstR. conorii (5.6%),R. typhi (4%), but not againstE. chaffeensis. By Western immunoblotting, seroprevalence forR. conorii was in Casablanca and 4.8% in Fez. Antibodies reactive at titers >=1:50 againstC. burnetii (phase II) were present in sera from Casablanca (1%) and Fez (18.3%).Abbreviations IFA Immunofluorescence assay - MSF Mediterranean spotted fever - PBS Phosphate-buffered saline     

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.     

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     

Selenium content of Portuguese unifloral honeys

The selenium contents of a total of 62 unifloral honeys from Erica spp., Castanea sativa, Eucalyptus spp., Lavandula stoechas, Citrus spp. and Echium plantagineum honeys collected in Portugal were determined by fluorometry after reaction with 2,3-diaminonaphthalene. The selenium levels of the honey samples studied were low, ranging from <1.0 to 2.91 μg/100 g fresh weight. The honeys from Erica spp., C. sativa and E. plantagineum presented the highest selenium values from all the honeys studied (median values 1.69, 1.51 and 1.51 μg/100 g fresh weight), and the honeys from Eucalyptus spp., L. stoechas and Citrus spp. presented the lowest values (median values 1.33, 1.28 and 1.20 μg/100 g fresh weight). The selenium content of Erica spp., was significantly higher than that observed for the Eucalyptus spp., L. stoechas and Citrus spp. and the selenium level of the Eucalyptus spp., was also significantly lower than that observed C. sativa and E. plantagineum honeys. From these results it can be concluded that honey is a marginal source of Se for the Portuguese population.     

Brucella phagotypes : Their relation to the spread of infection in Italy

The spread of Brucella infection in man in Italy during the last three years is briefly reviewed with reference to the Brucella strains collected and typed.The strains were tested by H₂S production, dye-inhibition, agglutination by monospecific sera, and sensitivity to a phage set. From 108 tested strains, 91 have been identified by means of the traditional tests as Br. melitensis, sometimes with some irregularities, 10 as Br. abortus, while 7 were not typable.It was possible to recommend some phage sensitivity patterns of Br. melitensis for epidemiological purposes: one phagotype is much more frequent in the north, another in the south of Italy.However, the currently recommended phagotypes must be considered provisional and will be modified in the light of more extensive studies.Corresponding author.