TLR2及其相关细胞因子在军团菌感染中作用

目的通过体外实验探讨Toll样受体2(TLR2)及肿瘤坏死因子-α(TNF-α)、白介素1β(IL-1β)、白介素6(IL-6)在军团菌感染中的作用。方法分离30名健康人外周血单核细胞(PBMC),将每名健康人PBMC分为对照组和军团菌刺激组,军团菌刺激组加入500μL 2×107/m L军团菌悬液,对照组加入500μL磷酸盐缓冲液(PBS),分别在18、24、72 h时获取细胞及上清液,采用real-time PCR法测定细胞中TLR2、My D88 mRNA的表达水平,ELISA法检测细胞培养上清液IL-6、IL-1β及TNF-α含量。结果与对照组比较,18h军团菌刺激组My D88 mRNA△Ct值(1.414 0±0.044 9)低于对照组(1.684 4±0.042 6),24h军团菌刺激组TLR2 mRNA△Ct值(1.347 9±0.056 2)低于对照组(1.425 9±0.038 7),72h军团菌刺激组TLR2 mRNA和My D88 mRNA△Ct值[(1.504 9±0.018 9)和(1.540 0±0.031 9)]均高于对照组[(1.410 5±0.025 5)和(1.339 2±0.032 2)],差异均有统计学意义(均P<0.05);18、24、72h军团菌刺激组细胞上清液中TNF-α、IL-1β、IL-6浓度均高于对照组,差异均有统计学意义(均P<0.05)。结论 TLR2及TNF-α、IL-1β、IL-6等相关炎性因子可有效抵制军团菌感染,TLR2介导的天然免疫可能是军团菌感染的保护因素。     

母源外周血和胎盘组织中Toll样受体9表达在HBV宫内传播中的作用

目的 探讨Toll样受体9（TLR 9）经血液和胎盘途径在HBV宫内传播（BIT）中的作用。方法 对陕西省西北妇女儿童医院分娩的290例HBsAg阳性产妇为病例组和45例健康产妇为对照组进行流行病学调查, ELISA法检测产妇及子代外周血乙型肝炎（乙肝）五项和TLR 9水平,实时荧光定量PCR检测HBV DNA水平;免疫组织化学法检测TLR 9在胎盘组织中的表达。采用病例对照研究方法分析发生BIT的HBsAg阳性产妇TLR 9水平差异。结果 HBsAg阳性产妇所生新生儿发生HBV宫内显性感染（DBI）率、宫内隐匿性感染（OBI）率和BIT率分别为9.28%（27/291）、40.21%（117/291）和49.48%（144/291）。HBsAg阳性产妇及未传播组（NBIT）和OBI组的TLR 9水平均显著低于对照组（P<0.001）,DBI组的TLR 9水平显著高于NBIT组和OBI组（P=0.000）; OBI组中HBeAg阴性组的TLR 9水平显著低于HBeAg阳性组（P=0.01）;HBV DNA载量分层中均随着BIT程度的加重,产妇外周血TLR 9含量明显增加（P<0.05）;抗病毒治疗、注射免疫球蛋白和未接种乙肝疫苗组,均随着BIT程度的加重,产妇外周血TLR 9含量明显增加（P<0.05）;DBI的胎盘组织中TLR 9表达显著高于OBI组和NBIT组（P<0.05）。结论 HBV一定程度下会抑制产妇体内分泌TLR 9,但HBeAg能刺激母体TLR 9分泌,随着BIT程度的加重,其体内TLR 9水平呈增高的组内交叉分化现象,因此,TLR 9不是一个能独立筛选分组的标记,但可以做为HBsAg阳性产妇监测管理的参考指标。     

虾青素改善脓毒症小鼠肠道损伤及其作用机制初探

目的 了解虾青素对脓毒症小鼠肠道损伤的作用, 并初步探讨其作用机制。 方法 采用盲肠结扎穿刺(CLP)所致脓毒症小鼠模型。采用随机数字法将62只雄性Balb/c小鼠随机分为假手术+溶剂对照组(Sham+Vehi组, n=11)、假手术+虾青素组(Sham+Asta组, n=11)、脓毒症模型+溶剂对照组(CLP+Vehi组, n=20)、脓毒症模型+虾青素组(CLP+Asta组, n=20)。含虾青素组中, 虾青素溶于食用橄榄油(40 mg/mL), 术前连续7 d 100 mg/(kg·d)灌胃; 含溶剂组中, 溶剂采用等量橄榄油灌胃处理(2.5 mL/kg)。假手术组随机选取5只小鼠、脓毒症模型组随机选取12只小鼠, 观察术后7 d生存情况; 剩余小鼠于术后18 h采用FD-40灌胃, 术后24 h检测小鼠肠道组织形态学、肠道功能损伤指标、肠组织氧化应激指标、炎症因子表达及过氧化物酶体增殖物激活受体γ(PPARγ)/核因子Kappa B (NF-κB)通路关键蛋白表达的变化。 结果 Sham+Vehi组及Sham+Asta组小鼠生存率、各肠道损伤指标、肠道炎症因子水平、氧化应激指标、肠组织损伤评分差异均无统计学意义(均P＞0.05);与Sham+Vehi组比较, CLP+Vehi组小鼠生存率明显降低, 血清二胺氧化酶(DAO)活性及I-FABP、D-乳酸、FD-40水平均明显上升, 肠组织中TNF-α、IL-1β、IL-6、丙二醛(MDA)水平均明显升高, 超氧化物歧化酶(SOD)活性降低, 肠道形态学损伤评分更高, 肠道组织中PPARγ表达增加, p-IκBα/IκBα及p-p65/p65比值均增加(均P＜0.05);与CLP+Vehi组相比, CLP+Asta组小鼠生存率提升, 血清DAO活性及I-FABP、D-乳酸、FD-40水平均明显降低, 肠组织中TNF-α、IL-1β、IL-6、MDA水平均明显下降, SOD活性增加, 肠道形态学损伤评分降低, 肠道组织中PPARγ表达进一步增加, p-IκBα/IκBα、p-p65/p65比值均下降(均P＜0.05)。 结论 虾青素减轻CLP所致脓毒症小鼠肠道损伤, 其机制可能与其调控PPARγ/NF-κB信号通路, 抑制炎症反应及氧化应激有关。     

HBsAg阳性产妇IL-18的表达在HBV宫内传播中的相关性研究

目的 探讨HBsAg阳性产妇外周血白介素18（IL-18）水平在HBV宫内传播（BIT）中的表达变化。方法 采用病例对照研究,以陕西省西北妇女儿童医院住院分娩的282例HBsAg阳性产妇为病例组,43例健康产妇为对照组进行流行病学调查,采用ELISA法检测孕妇和新生儿外周血乙型肝炎（乙肝）五项指标,采用实时荧光定量PCR检测HBV DNA水平,采用流式液相芯片法检测细胞因子IL-18水平。结果 HBsAg阳性产妇发生HBV宫内显性感染（DBI）率、HBV宫内隐匿性感染（OBI）率、BIT率分别为8.42%（24/285）、40.00%（114/285）和48.42%（138/285）。对照产妇的IL-18水平显著低于HBsAg阳性产妇组（P=0.001）、宫内未传播（NBIT）组（P=0.001）、OBI组（P<0.001）;HBeAg阴性组IL-18水平显著低于HBeAg阳性组（P=0.023）;产妇HBV DNA载量≥10³拷贝/ml,其IL-18水平显著高于对照组（P<0.01）,并随着母血中HBV DNA载量的增高,其IL-18水平呈增高趋势（P=0.024）,当HBV DNA载量在10³～10⁶拷贝/ml,其DBI组IL-18水平显著低于NBIT组（P=0.022）,并随着BIT程度的加重,其IL-18水平呈下降趋势（P=0.016）;未接种乙肝疫苗组中呈现随着BIT程度的加重,其IL-18含量明显减少的趋势（P=0.044）,未接种乙肝疫苗和乙肝免疫球蛋白组中,OBI组IL-18水平均显著高于NBIT组（P<0.05）;多因素分析结果显示,产妇HBeAg与母体IL-18水平的线性关系有统计学意义（P=0.01）。结论 IL-18是Th1/Th2网络平衡更高层次的调控者,监测HBsAg阳性孕妇体内IL-18水平,不仅可以对其新生儿发生DBI和OBI进行预判,而且可以考虑作为干预手段,尤其对于HBeAg阳性和HBV DNA载量≥10³拷贝/ml者,提高母体的细胞免疫功能,从而有利于控制BIT。     

七味白术散对抗生素相关性腹泻小鼠肠道糖苷水解酶活性的影响

目的 探究七味白术散对抗生素相关性腹泻(AAD)小鼠肠道β-D-葡萄糖苷酶和β-D-葡萄糖醛酸酶活性的影响, 从肠道糖苷水解酶角度阐释七味白术散治疗AAD的机制。 方法 采用混合抗生素灌胃制备AAD小鼠模型, 予七味白术散汤剂干预, 分别于造模和治疗后采集小鼠小肠内容物(SC)、小肠黏膜(SM)、结肠内容物(CC)、结肠黏膜(CM)标本检测糖苷水解酶活性, 采集血液与肝脏标本检测琥珀酸脱氢酶(SDH)和乳酸脱氢酶(LDH), 氧化应激功能相关指标丙二醛(MDA), 以及炎症相关指标白细胞介素-17(IL-17)和脂多糖(LPS)。 结果 AAD小鼠SC、SM及CC中β-D-葡萄糖苷酶和β-D-葡萄糖醛酸酶活性均明显下降(均P＜0.05), CM中两种糖苷水解酶活性均明显升高(均P＜0.05)。七味白术散治疗后, 小鼠各肠段的糖苷水解酶活性均较正常组和自愈组高, 血中MDA、LDH、IL-17和LPS含量较自愈组降低, SDH较自愈组升高。 结论 抗生素导致小鼠SC、SM和CC中糖苷水解酶活性下降, CM中糖苷水解酶活性升高, 七味白术散能较好地调节AAD小鼠肠道糖苷水解酶活性及小鼠能量代谢、氧化应激和炎症因子, 恢复小鼠的代谢能力, 改善小鼠肠道环境, 从而治疗腹泻。     

布鲁氏菌104M液体气溶胶免疫BALB/c小鼠的有效性评价和安全性研究

目的 评价布鲁氏菌104M液体气溶胶肺递送途径免疫BALB/c小鼠有效性和安全性。方法 随机选取6～8周龄BALB/c雌鼠,分别经肺递送、滴鼻和皮下注射3种途径免疫接种布鲁氏菌104M,于免疫后第4、8、16、24周观察并记录小鼠的症状、检测小鼠体重、脾重、脾脏载菌量及肺匀浆、血清的抗体和细胞因子。待鼠脾脏载菌完全清除,用布鲁氏菌A19液体气溶胶肺递送途径攻毒。结果 各组实验小鼠均未见异常症状;体重无显著下降;攻毒前,脾重没有明显变化;攻毒后,免疫组小鼠脾重显著低于空白对照组（P<0.05）：液体气溶胶肺递送：实验组（0.26±0.16）g<空白对照组（0.40±0.19）g,滴鼻：实验组（0.21±0.11）g<空白对照组（0.28±0.19）g,皮下注射：实验组（0.14±0.02）g<空白对照组（0.30±0.18）g。随着免疫时间的增长,免疫组小鼠脾脏载菌量呈下降趋势,第20周完全清除。攻毒后2周（免疫24周）,所有小鼠脾脏载菌均显著增加,各免疫组脾载菌量均显著低于空白对照组（P<0.05）：脾载菌量以log₁₀菌落形成单位（colony-forming units,CFU）/g计数并统计分析,液体气溶胶肺递送：实验组（4.49±0.13）<空白对照组（6.90±0.46）;滴鼻：实验组（3.59±1.06）<空白对照组（7.08±0.14）;皮下注射：实验组（3.00±2.03）<空白对照组（6.81±0.34）。布鲁氏菌104M激发了BALB/c小鼠细胞免疫和体液免疫反应。在免疫后第4周,检测到104M特异性抗体IgG、IgM、IgA,第8周达到高峰,攻毒后再次显著上升。各免疫组血清和肺匀浆中IFN-γ和IL-18浓度在攻毒前,均显著高于空白对照组（P<0.05）,攻毒后,各免疫组血清IFN-γ和IL-18浓度均低于空白对照组（P<0.05）,而肺匀浆细胞因子浓度在攻毒前后均持续高于空白对照组（P<0.05）。结论 液体气溶胶肺递送途径是一种有效的免疫途径,表现出有效的保护作用;104M未引起小鼠体重减轻,相对安全,但在小鼠体内存活时间较长,引起小鼠轻度脾脏肿大,有一定的残余毒力。     

HBsAg阳性产妇孕晚期IFN-γ和IL-12表达对HBV宫内传播的影响

目的 探讨HBsAg阳性产妇外周血IFN-γ和IL-12水平对HBV在宫内传播（BIT）中的影响。方法 采用病例对照研究,连续收集2015年1月至2017年5月陕西省西北妇女儿童医院分娩的282例HBsAg阳性产妇为病例组,以43例健康产妇为对照组进行流行病学调查,采用ELISA法检测临产前产妇的外周血乙型肝炎（乙肝）五项指标,采用实时荧光定量PCR检测HBV DNA水平,采用流式液相芯片法检测细胞因子IFN-γ和IL-12水平;对其所生285例新生儿于产后24 h内静脉血进行乙肝五项和HBV DNA水平检测。结果 HBsAg阳性产妇人群发生HBV宫内显性感染（DBI）率、HBV宫内隐匿性感染（OBI）率、BIT率分别为7.37%（21/285）、40.70%（116/285）和48.07%（137/285）。对照组IFN-γ水平显著低于HBsAg阳性产妇组（t=-2.55,P=0.011）、NBIT组（t=-2.54,P=0.012）和OBI组（t=-2.33,P=0.021）,对照组中IL-12水平显著高于NBIT组（t=2.07,P=0.040）和DBI组（t=4.81,P=0.000）;对照组IL-12水平显著高于HBsAg阳性产妇的HBeAg阴性组（t=-2.09,P=0.038）;HBV DNA载量在10³～10⁶拷贝/ml组中DBI组IFN-γ水平显著低于OBI组和NBIT组（P<0.01）;注射免疫球蛋白组中随着BIT程度的加重,其IFN-γ含量明显减少（χ²=6.40,P=0.041）,抗病毒治疗组中随着BIT程度的加重,其IL-12含量明显减少（χ²=8.90,P=0.012）;产妇年龄、前置胎盘和乙肝疫苗注射与母体IFN-γ水平的线性关系有统计学意义（P<0.05）,破膜方式和乙肝疫苗注射与母体IL-12水平的线性关系有统计学意义（P<0.05）。结论 HBV可以激发孕产妇体内IFN-γ的表达,同时抑制IL-12的分泌,但是IFN-γ在HBsAg阳性产妇体内的表达呈现组内分化现象,在HBeAg阳性和高载量HBV DNA的环境下母体IFN-γ的水平会下降;提高HBsAg阳性产妇的IFN-γ和IL-12水平,有利于阻断BIT尤其是DBI。     

TLR4抗体对姬松茸多糖作用巨噬细胞产生细胞因子的影响

目的研究TLR4抗体对巴氏蘑菇多糖(Agaricus blazei Murrill polysaccharide,ABPS)对体外巨噬细胞RAW264.7产生细胞因子白介素-1β(IL-1β)、肿瘤坏死因子--α(TNF-α)、干扰素-β(IFN-β)的影响。方法相同浓度ABPS及脂多糖(LPS,阳性对照)作用巨噬细胞RAW264.7 3 h、6 h、12 h、18 h和36 h;不同浓度ABPS及LPS作用巨噬细胞RAW264.7 24 h;TLR4抗体作用巨噬细胞RAW264.7 1 h后,更换含有ABPS和LPS的细胞培养液作用24h。收集细胞培养上清,采用ELISA法检测细胞培养上清细胞因子IL-1β、TNF-α、IFN-β的含量。结果 ABPS作用巨噬细胞RWA264.7 24 h后,细胞培养上清中IL-1β、TNF-α、IFN-β含量明显高于阴性对照,差异有统计学意义(P0.01),但显著低于LPS组。在一定浓度范围内,细胞培养上清中IL-1β、TNF-α、IFN-β的含量随ABPS浓度增大而增大,浓度为1000μg/ml时IL-1β、TNF-α、IFN-β含量达到最大。TLR4抗体处理的巨噬细胞RAW264.7经ABPS和LPS作用,IL-1β、TNF-α、IFN-β含量低于未处理组,差异有统计学意义(P0.01)。结论 TLR4抗体能够一定程度抑制ABPS作用巨噬细胞RAW264.7产生IL-1β、TNF-α、IFN-β,推测ABPS可能通过TLR4受体信号转导通路影响三种细胞因子的释放。     

八段锦对社区老年人平衡功能影响效果的整群随机对照试验研究

目的 评价八段锦锻炼6个月对社区老年人平衡功能的影响。方法 使用两平行组整群随机对照试验的方法对我国5个省（市）40个社区的1 028名60~80岁社区居住老年人进行干预研究。干预组研究对象（20个社区、523名）进行每天1 h、每周5 d、持续6个月的八段锦锻炼和3次预防老年人跌倒健康教育；对照组研究对象（20个社区、505名）仅接受3次预防跌倒健康教育。研究主要指标为Berg平衡量表（BBS）得分，次要指标包括单脚站立时间、双脚前后站立时间、闭目原地踏步时间、计时起立行走时间。结果 1 028名研究对象进入分析，包括731名女性（71.11%）和297名男性（28.89%），年龄（69.87±5.67）岁。与基线调查相比，干预3个月后干预组BBS得分较对照组增加3.05（95%CI：2.23~3.88）分（P<0.001）；干预6个月后干预组BBS得分较对照组增加4.70（95%CI：4.03~5.37）分（P<0.001）。与对照组相比，干预6个月后干预组研究对象的各项次要指标均有改善（P<0.05）。结论 八段锦运动可以提高60~80岁社区老年人的平衡功能，运动时间越长，改善效果越好。     

危重症新型冠状病毒肺炎合并多重耐药菌感染危险因素

目的 分析重型、危重型（以下简称危重症）新型冠状病毒肺炎（COVID-19）合并多重耐药菌感染的危险因素。 方法 回顾性分析某省某定点医院2020年1—4月重症隔离病区危重症COVID-19患者的临床资料,选取合并多重耐药菌感染的患者为病例组,未合并多重耐药菌感染的患者为对照组。比较两组患者临床资料,采用多因素logistic回归分析危重症COVID-19合并多重耐药菌感染的危险因素。 结果 共有62例危重症COVID-19患者。其中合并多重耐药菌感染患者10例,未合并多重耐药菌感染患者52例。62例患者中14例合并细菌或真菌感染,感染率为22.6%;10例合并多重耐药菌感染,感染率为16.1%,分别为耐碳氢霉烯类肺炎克雷伯菌（CRKP）感染4例,耐碳氢霉烯类鲍曼不动杆菌（CRAB）感染6例;合并非多重耐药菌或真菌感染共9例（11株）。单因素分析结果表明,病例组中心静脉置管比例、抗菌药物使用种类、使用抗菌药物种类≥4种比例均高于对照组;病例组清蛋白水平低于对照组;差异均有统计学意义（均P < 0.05）。多因素分析结果表明,危重症COVID-19合并多重耐药菌感染独立危险因素为抗菌药物使用种类≥4种（OR=17.104,95%CI：1.805~162.033）,清蛋白为保护因素（OR=0.834,95%CI：0.709~0.982）。 结论 危重症COVID-19患者应合理使用抗菌药物,提高清蛋白水平,有利于预防与控制危重症COVID-19合并多重耐药菌感染的发生。     

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.