Ni、Zn对三疣梭子蟹幼体发育的慢性毒性(The Chronic Toxicity of Ni and Zn on Larval Development of Portunus trituberculatus)

为研究Ni、Zn对三疣梭子蟹幼体的毒性,进行了浓度为1/4至8倍渔业水质标准的Ni、Zn(Ni为0.05～0.4mg·L-1;Zn为0.1～0.8mg·L-1)对蟹幼体生长发育的毒性影响试验.1)Ni对蟹幼体生长发育的毒性影响:Ni浓度为1～8倍渔业水质标准时,蟹幼体混合存活率极显著低于对照组(p<0.01).Ni浓度为4倍渔业水质标准时,蟹幼体发育至Z4就全部死亡,8倍仅发育至Z2就全部死亡;4倍以上时,各期幼体存活率和阶段存活率均显著低于对照组(p<0.05或p<0.01).4倍以上时,蟹幼体发育的最短和最长时间及平均时间均显著高于对照组(p<0.05或p<0.01).这说明,进行三疣梭子蟹幼体培育,4倍以上Ni浓度为不适浓度,1～2倍为可行浓度,1/2倍以下为适宜浓度.2)Zn对蟹幼体生长发育的毒性影响结果发现,Zn浓度为8倍渔业水质标准时,蟹幼体混合存活率显著低于对照组(p<0.01),4倍以下时没有显著差异(p>0.05).4倍时蟹幼体仅发育至C1就全部死亡,8倍仅发育至Z2就全部死亡;4～8倍时各期幼体存活率和阶段存活率均极显著低于对照组(p<0.01).2倍以上时,蟹幼体发育的最短时间显著高于对照组(p<0.05);4倍以上时,蟹幼体发育的平均时间显著高于对照组(p<0.05).这说明,进行三疣梭子蟹幼体培育,4倍以上Zn浓度为不适浓度,2倍Zn浓度为可行浓度,1倍以下为适宜浓度.     

甲状腺激素脱碘酶在孕哺期BDE 209暴露致子代小鼠神经发育毒性中的潜在作用

研究孕哺期BDE 209暴露对母鼠胎盘和子代脑组织甲状腺激素脱碘酶(deiodinase, DI)基因表达的影响,及其在子鼠神经发育毒性效应中的作用。将75只雌性昆明小鼠随机分为对照组、低剂量组和高剂量组,暴露BDE 209 10 d后,与雄鼠合笼,每组选取怀孕时间相近(相差不过2 d)的8只母鼠孕期持续染毒至子鼠断乳。采用实时荧光定量PCR检测孕17～18 d胎盘、出生后60 d子鼠脑组织三种类型脱碘酶基因相对表达;利用Morris水迷宫评价出生后60 d子鼠学习记忆能力;测量第2、16、30和60 d子鼠体重,观察孕哺期BDE 209暴露对子代生长发育的作用。结果显示,BDE 209对子鼠出生时体重未见明显影响;出生后30 d,高剂量BDE 209暴露组雌性子鼠体重显著低于对照组子鼠体重(p<0.05),而低、高剂量暴露组雄性子鼠体重均显著低于对照组子鼠体重(p<0.05,p<0.01);出生后60 d,BDE 209对体重影响不明显。BDE 209暴露能够显著延长出生后60 d雌、雄性子鼠逃避潜伏期(p<0.05或p<0.01)。BDE 209暴露显著降低母鼠胎盘中三种类型脱碘酶(主要是DI-3)基因表达(p<0.05或p<0.01);同时,BDE 209暴露可诱导出生60 d后雄性子鼠脑组织中DI-1基因表达(p<0.05或p<0.01),抑制雄性子鼠脑组织中DI-3基因表达(p<0.05);BDE209暴露对出生后60 d雌鼠脑组织脱碘酶未见明显影响(p>0.05)。研究结果表明,孕哺期BDE 209暴露可能通过影响母鼠胎盘组织脱碘酶(特别是DI-3)基因表达,导致子鼠神经发育毒性效应-学习记忆能力障碍。     

邻苯二甲酸二乙基己酯(DEHP)对小白鼠肝脏毒性及脂质过氧化损伤

为研究邻苯二甲酸二乙基己酯(DEHP)对小鼠肝脏的毒性及脂质过氧化损伤作用机制,选择昆明4周龄小鼠80只,雌雄各半,随机分为4组。经食饵连续自然给食染毒,于染毒第4周末处死。测量小鼠肝脏和体重的变化,测定不同DEHP染毒剂量组小鼠的血液、肝脏中谷胱甘肽过氧化物酶(GPX)、过氧化氢(H2O2)和丙二醛(MDA),超氧化物歧化酶(SOD)的变化。将实验数据进行ANO-VA分析处理。结果表明,随着染毒剂量的增加,小鼠体重逐渐减少(p<0.01),高剂量组肝脏器系数明显上升(p<0.01)。苏木精-伊红染色法(简称HE染色)可见高剂量组肝脏组织有明显损伤。与对照组相比,DEHP3个剂量染毒组小鼠血液(75mg·kg-1组除外)及肝脏中GPX活性降低(p<0.05,p<0.01),H2O2含量增加(p<0.05,p<0.01);肝组织中(75mg·kg-1组除外)SOD活性降低(p<0.05,p<0.01),MDA含量增加(p<0.01)。以上结果说明DEHP对小鼠肝脏的毒性作用机制可能为脂质过氧化反应。     

利用三油酸甘油酯-醋酸纤维素复合膜评价土壤中多环芳烃的生物可利用性

将一种新型被动式采样器——三油酸甘油酯-醋酸纤维素复合膜(TECAMs)暴露于10种人工老化土壤中富集萘、菲、芘和苯并[a]芘4种多环芳烃(PAHs),并与土壤模型动物——赤子爱胜蚓(Eiseniafoetida)进行比较以研究该采样器用于评价土壤中多环芳烃生物可利用性的可能性.研究结果表明,TECAMs能有效富集土壤中萘、菲、芘和苯并[a]芘,并在48h内基本达到平衡,远快于赤子爱胜蚓的21d平衡时间.TECAMs内PAHs含量与土壤溶解有机碳(DOC)含量呈正相关(p<0.05),而与土壤中总有机质(TOM)含量呈负相关(p<0.05),土壤pH对TECAMs富集PAHs的影响不显著(p<0.05).TECAMs内PAHs含量与土壤中PAHs含量、赤子爱胜蚓体内PAHs含量均呈显著线性正相关(p<0.05,p<0.01).研究结果表明TECAMs有可能应用于评价土壤中PAHs的生物可利用性.     

Promotive Effect of Glutathione on the Formation of DNA-Protein Crosslinks Induced by Formaldehyde in vitro and in vivo

研究发现,在环境水平的甲醛染毒之后,动物体内的谷胱甘肽(GSH)含量会发生显著减少,并呈现剂量-效应关系.值得思索的是,GSH的减少对甲醛所致的遗传毒性指标DNA-蛋白质交联(DPC)没有明显的保护作用.为了深入探讨GSH与甲醛的联合作用,进行了体外和体内两项实验.体外实验以Hela细胞为实验材料,实验组分为4组:对照组、250μMGSH组、250μM甲醛组、250μM甲醛和250μMGSH联合作用组;体内实验以昆明小鼠为实验材料,采用腹腔注射方法连续染毒两周.实验组分为4组:对照组、1mMGSH组、1mM甲醛组、1mM甲醛和1mM GSH联合作用组.体外实验与体内实验结果表明,单独GSH染毒组所致DPC与试剂对照组之间没有统计学差异(p>0.05;p>0.05),甲醛染毒组所致DPC显著高于对照组(p<0.01;p<0.05),联合作用组所致DPC不但显著高于试剂对照组(p<0.01;p<0.01)而且还显著高于甲醛染毒组(p<0.05;p<0.01).结果提示,GSH单独作用不能诱导DPC形成,但是GSH对甲醛所致的DPC具有促进作用.同时论文对这种协同作用的发生机制进行了讨论,作者认为GSH与甲醛的协同作用,和GSH与一氧化氮的协同作用的分子机制类似。     

汞、硒暴露对紫贻贝(Mytilus edulis)抗氧化酶系统的影响

为了研究重金属汞及微量元素硒对海洋贝类的毒性效应,揭示汞、硒在生物体内的相互作用机制,用汞和硒对指示生物紫贻贝(Mytilus edulis)进行单一及联合亚慢性暴露实验。设置对照组(0μg·L-1)、汞暴露组(25μg·L-1Hg2+)、硒暴露组(4μg·L-1Se4+)以及硒汞联合暴露组(25μg·L-1Hg2++4μg·L-1Se4+)4个实验组,并分别在暴露期间的第0、2、4和6天定时采集样本,测定紫贻贝鳃SOD、GPx及CAT3种抗氧化酶活性。将实验数据进行ANOVA分析处理后,结果表明:与对照组相比,汞暴露组SOD和GPx均呈现先显著升高(p<0.05或p<0.01)后降低(p<0.01或p<0.001)的趋势,CAT则从第4天开始显著降低(p<0.05);硒暴露组中SOD活性始终高于对照组(p<0.001),GPx活性在第2天也显著升高(p<0.001),CAT活性始终与对照组相近;硒汞联合作用与汞暴露组相比,SOD、GPx和CAT活性在不同时间点均有显著升高(p<0.05),而与硒暴露组相比,3种酶活性均低于硒单独暴露的水平。说明汞在短期能够诱导抗氧化酶活性,随着暴露时间的延长,则表现出明显的抑制作用;微量硒能够增强抗氧化酶系统活性,对汞导致的氧化损伤具有拮抗作用。     

氯氰菊酯胁迫下鲫鱼肾脏LDH同工酶和血清GOT、SOD活性的变化

为探讨氯氰菊酯对鱼类代谢关键酶活性的影响,以鲫鱼(Carassius auratus)为受试材料,采用室内人工水族箱培养方法进行毒性实验.在急性毒性实验基础上,设置了2、5、10μg·L-13个浓度组和1个对照组进行染毒,分别测定鲫鱼肾脏乳酸脱氢酶同工酶(LDH)、血清谷草转氨酶(GOT)和超氧化物歧化酶(SOD)的活性.结果表明,氯氰菊酯对鲫鱼的96h LC50为20.74μg·L-1.经不同浓度组染毒处理4d后,随着氯氰菊酯浓度的升高,鲫鱼血清GOT活性显著升高(p<0.05);SOD活性则表现为先升高后降低(p<0.05);肾脏LDH同工酶酶谱带型也发生了明显的变化,表现为LDH2、LDH3、LDH4的酶谱带染色浓、谱带较宽.以上结果表明氯氰菊酯对鲫鱼代谢关键酶的活性有一定影响,对鲫鱼的肾脏有一定损伤作用.     

碲化镉量子点对小鼠睾丸组织的氧化损伤（Effects of CdTe Quantum Dots on the Antioxidant Enzymes Activity and Lipid Peroxidation in Testes of Mice）

为探讨碲化镉量子点(CdTeQDs)对小鼠睾丸的急性氧化损伤作用,将20只雄性ICR小鼠随机分成4组:对照组、1d、3d、7d(3个不同时间组),采用尾静脉注射进行一次性染毒2.5μmol·kg-1CdTeQDs,对照组注射等体积生理盐水.染毒后对睾丸的脏器系数以及组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活性,丙二醛(MDA)含量分别进行测定,从而检测CdTeQDs对睾丸组织的急性氧化损伤作用.结果显示,与对照组相比,随染毒时间的延长,睾丸脏器系数无显著性变化(p>0.05);GSH-Px和SOD活性随染毒时间的延长呈逐渐升高趋势;而CAT活性呈逐渐降低趋势,且与对照组差异显著(p<0.01);MDA含量显著高于对照(p<0.01),且随时间变化不大.CdTeQDs染毒可导致小鼠睾丸组织氧化损伤,其损伤程度与染毒时间之间具有一定的时间-效应关系.     

邻苯二甲酸二丁酯（DBP）对斑马鱼（Brachydanio rerio）生理生化特性的影响

为了研究邻苯二甲酸二丁酯(DBP)对水生生物的毒性效应,将斑马鱼(Brachydanio rerio)暴露于DBP5个浓度组中96h急性染毒,测得其半致死浓度(96h-LC50)为8.51mg·L-1,从而得出其安全浓度为0.85mg·L-1.在此基础上,等对数浓度差设置4个质量浓度0.38、0.85、1.90、4.25mg·L-1进行20d慢性染毒,期间每5d测定斑马鱼的体重、肝重和鳃重,同时测定斑马鱼肝脏、鳃中SOD酶和ATPase活性.结果表明,斑马鱼比肝重总体随DBP浓度的增加和暴露时间的延长而升高(p<0.01),而比鳃重总体变化不大.随DBP浓度增大和暴露时间延长,斑马鱼肝脏、鳃中SOD酶和ATPase活性均显著受到抑制(p<0.01).     

全氟辛烷磺酸盐(PFOS)胁迫对翡翠贻贝抗氧化酶的影响

为了解全氟辛烷磺酸盐(PFOS)对海洋贝类抗氧化防御系统的毒性效应及致毒机理,在实验室条件下研究了PFOS对翡翠贻贝的96h急性毒性,同时探讨PFOS胁迫和净水恢复过程中翡翠贻贝外套膜和内脏团组织中抗氧化指标(SOD活性、GSH和MDA含量)的变化。结果显示,PFOS对翡翠贻贝的96h半致死浓度(LC50)为68.3mg·L-1,安全浓度为6.83mg·L-1。在PFOS胁迫阶段,1mg·L-1浓度组外套膜SOD活性显著性升高(p<0.05),内脏团SOD酶活性显著降低(p<0.05);而PFOS浓度高于1mg·L-1时,外套膜SOD活性显著性降低(p<0.05),内脏团SOD活性显著升高(p<0.05)。PFOS胁迫对翡翠贻贝外套膜和内脏团中GSH含量均有显著的诱导作用(p<0.05),PFOS胁迫15d后各浓度组GSH含量均受到显著的抑制(p<0.05)。翡翠贻贝外套膜MDA含量受PFOS胁迫后显著升高(p<0.05),内脏团MDA含量的变化呈先降低、后升高的规律。净水释放阶段,翡翠贻贝两组织中SOD活性在释放7d后均恢复至对照组水平,GSH含量和MDA含量呈显著升高的趋势(p<0.05)。研究结果表明,PFOS暴露能够引起翡翠贻贝外套膜和内脏团氧化胁迫,但这种损伤的效果不明显,释放短时间后即可自我恢复。     

Clinical and analytical follow‐up of 25 persons exposed accidentally to beryllium†

An accidental exposition of 25 persons to beryllium dust was used to follow up trace analytical and clinical parameters over a period of 10 months. Although no exposed person shows any symptoms of an acute beryllium intoxication, up to 5‐fold increased beryllium concentrations could be analysed in serum samples about 10 hours after exposition. The beryllium clearance shows a biological half time in the range of 2 to 8 weeks. The beryllium determination in the nanogram range was carried out using a combined method by flameless a.a.s. with a detection limit of 0.6 ppb Be and a relative standard deviation from 20 to 4% in relation to the concentration range of beryllium measurement.

Beryllium analyses are completed by thorax X‐ray, spirometry, y‐globulins and liver enzymes (SGOT, SGPT), which have shown no pathological values. Because it is known for beryllium to sensitize the cellular immune response, neopterin measurement was used to determine the activity of the immune system. Neopterin, a pteridine synthesized by activated macrophages after stimulation by gamma‐interferon derived from sensitized T‐lymphocytes, was determined in urine samples by HPLC combined with an fluorescence detector. Only in two cases a slight increase of neopterin has been found. As a result of this study it can be summarized, that a short‐time exposure to beryllium (10–20 h), which results in a increase of beryllium in serum to the fivefold normal beryllium level, does not initiate any symptoms of an acute beryllium intoxication. The exposed persons are controlled in future to evaluate the further course.     

Occupational risk of exposure to methicillin-resistant Staphylococcus aureus (MRSA) and the quality of infection hygiene in nursing homes

• Staff members were not colonised with MRSA. • But staff were exposed to MRSA from air, sedimented dust and surfaces. • MRSA was found in the rooms of MRSA-colonised residents but not in common areas. • Staff worry about MRSA and spreading it to other residents, family, and acquaintances. • The use of protective eyewear and facemasks could be improved. Methicillin-resistant Staphylococcus aureus (MRSA) is an increasing health concern across the globe and is often prevalent at long-term care facilities, such as nursing homes. However, we know little of whether nursing home staff is exposed to MRSA via air and surfaces. We investigated whether staff members at nursing homes are colonised with and exposed to culturable MRSA, and assessed staff members’ self-reported knowledge of MRSA and compliance with infection hygiene guidelines. Five nursing homes with MRSA positive residents were visited in Copenhagen, Denmark. Personal bioaerosol exposure samples and environmental samples from surfaces, sedimented dust and bioaerosols were examined for MRSA and methicillin-susceptible S. aureus (MSSA) to determine occupational exposure. Swabs were taken from staffs’ nose, throat, and hands to determine whether they were colonised with MRSA. An online questionnaire about MRSA and infection control was distributed. No staff members were colonised with MRSA, but MRSA was detected in the rooms of the colonised residents in two out of the five nursing homes. MRSA was observed in air (n = 4 out of 42, ranging from 2.9–7.9 CFU/m³), sedimented dust (n = 1 out of 58, 1.1 × 10³ CFU/m²/d), and on surfaces (n = 9 out of 113, 0.04–70.8 CFU/m²). The questionnaire revealed that half of the staff members worry about spreading MRSA to others. Identified aspects for improvement were improved availability and use of protective equipment, not transferring cleaning supplies (e.g., vacuum cleaners) between residents’ rooms and to reduce worry of MRSA, e.g., through education.     

Light‐induced changes in rabbit pineal gland n‐acetyltransferase activity

N‐acetyltransferase (NAT) activity was determined in different ages of New Zealand White rabbit pineal gland using 2‐aminofluorene and p‐aminobenzoic acid as substrates and it was assayed by high pressure liquid chromatography. Rabbits of different ages were either sacrificed during the light phase, exposed to darkness or light for 1 min during the dark phase of the lighting cycle, returned to their cages in darkness for 30 min and then sacrificed. Pineal gland NAT activity in animal nocturnally exposed to 1 min of light was inhibited in animals 1 ‐day‐old of age. Nocturnal light exposure did not inhibit enzyme activity in 1‐day‐old rabbit, even though these animal displayed clear light : dark differences in pineal gland NAT activity. Nocturnal light exposure also did not inhibit night time levels of NAT activity in 1‐day‐old animals who had been bilaterally enucleated. The result suggested that this effect is retinally mediated. Pre‐treatment of 1‐day‐old and 60‐day‐old animals with the isoproterenol (beta‐noradrenoreceptor agonist drug), prevented the nocturnal light‐induced inhibition of NAT activity. The different sensitivity of 60‐day‐old and 1‐day‐old animals to different illuminances or durations of nocturnal light exposure, was that the duration or intensity of light exposure was enable to inhibit nocturnal NAT activity. The NAT activity was at least 3.2‐ to 4.6‐fold greater in 1‐day‐old rabbits compared to 60‐day‐old rabbits. Kinetic constants for arylamine NAT activity in pineal gland from rabbits were determined. K_m and F_max values for 2‐aminofluorene were 2.6‐fold higher for light exposure than for no light exposure rabbits. This is the first demonstration of the retina‐pineal gland pathway appears light‐induced changes in pineal glands of animals in 1‐day‐old of ages or older; but this pathway does not function in 60‐day‐old rabbits like manner in 1‐day‐old rabbits.