藻毒素的人类健康效应及危险性评估

藻毒素可能通过饮水、娱乐用水等途径对人类健康产生不利影响,但是,国际上尚未制订藻毒素的正式指导值.该文介绍了有关藻毒素的人类健康效应、暴露途径、可能的指导值及其计算方法.这不仅为进行危险性管理提供依据,而且有助于制定不会对人类产生危险性的正式指导值.同时,有助于改善饮水供应的安全性.     

硅藻多不饱和脂肪酸免疫调节作用的研究

<正>硅藻是一类单细胞藻类,能够产生大量的油脂成分,许多硅藻种类含有大量的二十碳五烯酸(EPA),如:在Nitzschia alba和Nitzschia laevis这两个品系中较高[1]。后者的油脂含量高达干重的40%,其中的脂肪酸主要为C14:0、C16:0、C16:1、C20:4和C20:5,还含有少量的     

藻毒素的特性与其净水工艺选择

综述了藻毒素的基本特性，对几种净水工艺去除藻毒素的性能进行了比较和讨论。认为强化预处理＋常规工艺，常规工艺＋活性炭吸附，常规工艺＋膜技术处理是有效的净水工艺措施。     

生物毒素的军事意义

某些生物毒素因其具有致病力强、容易大量生产及稳定性高等特点，具有重要的军事意义。本文简要论述了毒素战剂的概念、特点、历史、科学技术进步的影响、外军关注的主要毒素战剂种类及研究重点领域等内容，并提出了毒素战剂防护的重点     

Toxins of concern to animals and people

Historically veterinarians have diagnosed accidental poisonings and identified possible terrorist events before they have come to the attention of public health authorities. There are many toxins that pose a threat to both humans and animals and the authors examine several of them here, namely, anthrax, tricothecenes, staphylococcal enterotoxin B, botulinum toxins, ricin, saxitoxin and dinoflagellate toxins. By discussing exposure routes, clinical signs and differential diagnoses the authors demonstrate how veterinarians are in a unique position to recognise zoonotic diseases, toxin exposure, and acts of bioterrorism. The work of veterinarians protects the food supply and contributes to human health and this article highlights the importance of coordination and communication between veterinarians and physicians. Sharing information is critical in confirming diagnoses and, in the case of intentional toxin attacks, could also be beneficial in identifying the perpetrators of the crime.     

Serum Concentrations of Antibodies Against Vaccine Toxoids in Children Exposed Perinatally to Immunotoxicants

Background

Polychlorinated biphenyls (PCBs) may cause immunotoxic effects, but the detailed dose–response relationship and possible vulnerable time windows of exposure are uncertain. In this study we applied serum concentrations of specific antibodies against childhood vaccines as sentinels of immunotoxicity.

Objectives

The main objective was to assess the possible dependence of antibody concentrations against diphtheria and tetanus toxoids in children with regard to prenatal and postnatal PCB exposures.

Methods

From a cohort of 656 singleton births formed in the Faroe Islands during 1999–2001, children were invited for examination with assessment of serum antibody concentrations at 5 years (before and after a booster vaccination) and at 7 years of age. Total PCB concentrations were determined in serum from ages 5 and 7 years, and data were also available on PCB concentrations in maternal pregnancy serum, maternal milk, and, for a subgroup, the child’s serum at 18 months of age.

Results

A total of 587 children participated in the examinations at ages 5 and/or 7 years. At age 5 years, before the booster vaccination, the antidiphtheria antibody concentration was inversely associated with PCB concentrations in milk and 18-month serum. Results obtained 2 years later showed an inverse association of concentrations of antibodies against both toxoids with PCB concentrations at 18 months of age. The strongest associations suggested a decrease in the antibody concentration by about 20% for each doubling in PCB exposure. At age 5 years, the odds of an antidiphtheria antibody concentration below a clinically protective level of 0.1 IU/L increased by about 30% for a doubling in PCB in milk and 18-month serum.

Conclusions

Developmental PCB exposure is associated with immunotoxic effects on serum concentrations of specific antibodies against diphtheria and tetanus vaccinations. The immune system development during the first years of life appears to be particularly vulnerable to this exposure.     

藻毒素致癌性研究进展

从3个方面综述了藻毒素致癌性的研究进展，水体藻毒素污染业已成为一个世界性的环境问题，而藻毒素潜在的促癌作用更是引起了各界的广泛关注。结构效应关系研究，体外短期筛选实验以及动物诱癌试验结果均表明藻毒素具有促癌作用，提示抑制蛋白磷酸酶活性，诱导增殖相关基因异常表达以及细胞信号传导和分裂增殖失控是藻毒素可能的致癌机制。     

NADase细菌毒素的活性测定

旨在建立一种测定ＮＡＤａｓｅ细菌毒素活性的非放射性测定法。本方法建立了一个ＮＡＤ（辅酶Ⅰ）依赖的显色系统，在该系统中，ＮＡＤ接受乳酸脱氢酶（ＬＤＨ）从乳酸脱下来的氢，再通过ＰＭＳ（吩嗪二甲酯硫酸盐）传递给ＩＮＴ（碘化硝基四氮唑蓝），使后者还原而显色。如果ＮＡＤａｓｅ毒素分解ＮＡＤ，就会打断递氢链而抑制显色反应。结果：显色系统中，ＮＡＤ含量与显色有良好线性关系（Ｒ＝０．９８９８）。绿脓杆菌外毒素Ａ分解ＮＡＤ而抑制显色反应。以毒素含量为自变量，以毒素对显色反应的抑制为应变量，建立了对数线性回归方程ｙ＝１２．５ｘ０．２６当ｙ＝５０％时［即显色系统中的ＮＡＤ有半数（２５０ｎｇ）被分解］，ｘ＝２０７（ｎｇ）。定义分解１ｎｇＮＡＤ的毒素活性为一个单位，则２０７ｎｇ毒素含有２５０个毒素活性单位。该方法的测定敏感性达到“ｎｇ”水平，表明本文建立的方法是一种敏感的测定ＮＡＤａｓｅ细菌毒素活性的非放射性测定方法     

The Preparation of Biochar Particles from Sludge and Corncobs and Its Pb2+ Adsorption Properties

Bulletin of Environmental Contamination and Toxicology - In the present study, biochar particles (BPs) produced by the co-pyrolysis of sewage sludge and corncobs at temperatures of 300, 500, and...     

黄浦区现制现售纯净水卫生学的现况调查

[目的]了解现制现售纯净水的卫生学状况,为今后对类似加盟连锁合作经营的现制现售纯净水制备场所进行预防性和经常性卫生监督确定关键控制点,进一步结合微生物学检查,为国家制定卫生标准提供参考依据.[方法]采用现况调查的方法,共调查本辖区内现制现售纯净水站24家和现制现售自动售水机26台,主要调查其生产条件、卫生设施、人员健康及个人卫生,并对现制现售纯净水、桶装水及有关可能影响卫生质量的因素进行主要微生物和理化指标分析.主要指标:色度、臭和味、浑浊度、pH、铅、砷、三氯甲烷、四氯化碳、耗氧量、电导率、细菌总数、总大肠茵群、粪大肠菌群.水质检测评判标准:<生活饮用水水质处理器卫生安全评价规范--反渗透处理装置>(2001);<中华人民共和国瓶装饮用纯净水卫生标准>GB 17324-2003. [结果]24家净水站均制作桶装水,均无生产日期标识,健康证持有率为58.93%;自动售水机(26台)露天放置,缺乏必要安全防护.在50件现制现售纯净水样中,细菌总数、总大肠菌群、粪大肠茵群合格率均为100%,色度、臭和味、pH、铅、砷、三氯甲烷、四氯化碳合格率均为100%,浑浊度合格率96.0%,耗氧量合格率82.0%,电导率不合格率为100%.在现制现售桶装纯净水96件中,细菌总数合格率81.3%.总大肠茵群合格率96.9%,粪大肠菌群合格率100%.现制现售纯净水与现制现售桶装纯净水的细菌总数比较,x2=10.69,P<0.005,两者的差别有统计学意义. [结论]加强市场准入和经常性卫生监督势在必行,应细化和完善各项监督和监测指标.以确保市场上现制现售纯净水的卫生、安全.     

双层壳聚糖／羟基磷灰石复合支架的制备及性能研究

目的：探索制备一种壳聚糖（CS）／羟基磷灰石（HA）双层复合支架的方法，对支架的理化性质进行检测。方法：在3％（m/V）壳聚糖溶液中加入一定量的聚乙二醇，离心去除气泡。将HA支架放入模具中．取配好的壳聚糖溶液，倒入模具中，放入冰箱冷冻，在冷冻抽干机中冻干，制成HA／壳聚糖（CS）支架。采用外观、红外光谱、电镜、乙醇替代、生物力学测定等方法检测支架的材料、内部结构（孔径、孔相通性）、孔隙率、力学性能，考察将其作为骨软骨组织工程支架材料应用的可行性。结果：双层复合支架外观上模拟骨软骨组织学结构．材料为壳聚糖、羟基磷灰石，平均孔径分别为CS层300μm，HA层350μm，孔相通性好，CS孔隙率为（76．00±5．01）％，HA孔隙率为（72．00±4．23）％。CS支架弹性模量为（2．8±0．5）MPa，HA支架的弹性模量为（150±11）MPa。结论：壳聚糖（CS）／羟基磷灰石（HA）双层复合支架符合骨软骨组织工程支架要求．具有较好的应用前景。     

超净化手术室的使用与管理

为提供一个洁净的手术环境，有效控制切口感染率，我们对医院新建超净化手术室进行了科学管理和质量监控，严格做好手术室卫生清洁工作，为手术间达到净化标准创造条件，在手术中重视全方位无菌技术的管理，真正有效地控制感染的发生，保证了手术质量。     

载银羟基磷灰石抗菌敷料制备及其性能研究

目的：制备抗菌性能优良的创伤敷料,并对该敷料进行结构表征和抗菌性能评价。方法：首先通过离子交换法制备载银羟基磷灰石（Ag—HA）,再利用柠檬酸将Ag—HA与纤维素复合制备Ag—HA抗菌敷料。通过XRD、SEM考察羟基磷灰石（HA）、Ag—HA的物相组成及形貌特征,采用平皿扩散法对Ag—HA敷料进行抗菌性能评价。结果：实验结果显示,Ag＋进入HA晶格内部,所得功能成分Ag—HA的载银率为2．5％。Ag—HA颗粒均匀分布于敷料表面,呈圆球状,直径为0-4～0．5um。Ag—HA敷料对S．aureus和E．coli的抑菌带宽分别为2．0、1．0mm。结论：Ag—HA敷料具有很强的抗菌性能．可作为灾害救援和野外作业等特殊环境下的创伤包扎敷料。