微囊藻毒素对鱼类毒性效应的研究进展

微囊藻毒素是由蓝藻产生的一类藻毒素.含一定浓度微囊藻毒素的水体可引起水生动物的不良反应,特别是鱼类.该文通过综述微囊藻毒素对鱼类胚胎孵化和发育的影响、对鱼类行为和生长的影响、在鱼类组织中的积累、对鱼类组织器官的影响,总结微囊藻毒素对鱼类的毒性效应.微囊藻毒素主要在鱼类肝脏中积累,还可在消化道和肌肉等组织中积累.在饥饿状...     

微囊藻毒素毒性研究进展

近年来,随着人类生产、生活活动的迅速发展,工农业排污的增加,各地水体富营养化日益加剧,导致江河、湖泊中藻类尤其是蓝藻异常繁殖生长而出现水华现象。当蓝藻水华严重时,水面形成厚厚的蓝绿色湖靛,散发出难闻的气味,不仅破坏了水生生态系统的平衡,而且因藻细胞破裂后释放出多种藻毒素而对人和动物的饮用水安全构成了严重的威胁。目前,由蓝藻水华现象引起的淡水污染在世界各地频繁发生,已成为全球关注的热点。日本、美国、澳大利亚、德国等20多个国家的淡水湖泊、水库等水体均发生过水华现象,且分离及检测到多种毒素。而我国在20世纪80年代进行的水源水质调查结果中显示34个湖泊中有一半以上的湖泊面积处于富营养化状态,进入90年代,全国淡水水体的富营养化状况更为严重,涉及的范围也在不断地扩大,已严重威胁人类的健康。     

微囊藻毒素及其毒性研究进展

微囊藻毒素是富营养化淡水水体中最常见的藻类毒素,它是一类具有多种异构体的环状多肽物质。由于其毒性大、分布广,从而成为水环境中的重要潜在危害物质。作者总结了微囊藻毒素的分子结构、理化性质及污染现状,并综述了有关其毒性及作用机理的国内外最新研究进展。     

微囊藻毒素遗传毒性研究进展

微囊藻毒素是淡水水体污染物中对人体健康威胁最大的一种细胞内毒素,主要表现为肝毒性[1],长期接触可损害细胞遗传物质。目前主要用微核试验、Ames试验、彗星试验等体内外试验检测其遗传毒性。作者综述了微囊藻毒素遗传毒性研究的试验方法、检测终点,并对其可能机制进行了初步的探讨。     

微囊藻毒素毒性机制研究进展

近年来,随着经济的迅猛发展,工农业以及生活污水排放增加,水体富营养化程度加剧。海洋、湖泊、河流等水体中由藻类(尤其蓝绿藻)引发的淡水水华现象日趋频繁[1]。在世界范围所发生的水华类型中,微囊藻水华(microcystisbloom)不仅发生频繁、危害大,且可产生微囊藻毒素(microcystins,MC)[2]。MCs是一类肽毒素,严重威胁着动物的生存以及人类健康。饮用水是MCs在日常生活中的     

淡水产品中微囊藻毒素富集及其危害

随着社会工业化进程的加快,人类在工农业生产及日常生活中,向水体排入大量的含氮、磷污染物,使水体富营养化,进而导致蓝藻\     

微囊藻毒素的细胞毒性研究进展

微囊藻毒素是微囊藻等淡水藻类产生的一类具有生物活性的环状7肽物质,它能抑制蛋白磷酸酶1和蛋白磷酸酶2A的活性,打破细胞内蛋白磷酸化/脱磷酸化的平衡,引起细胞损伤甚至坏死,对多种细胞产生毒性作用。本文就微囊藻毒素对不同细胞的毒性作用和机制及相关研究进行综述。     

微囊藻毒素的毒性及健康效应研究进展

由于水中氮、磷含量的急剧增加，导致水华在世界各地频频发生。除引起生态恶化外，因某些藻种所产生的藻毒素也给人类健康构成威胁。而淡水水华中目前最常见、对其毒性研究最为深入的是微囊藻毒素(Microcystin，MC)。且因其可能在饮用水中出现，世界卫生组织已把饮用水中MC的代表亚型MC-LR的基准值制订为1μg／L。本文对其理化性质、毒性表现、作用机制及流行病学调查的新进展作一综述。     

微囊藻毒素对鱼类免疫毒性的研究进展

微囊藻毒素(microcystins,MCs)是富营养化水体中最常见、毒性最强、研究最广泛的一类藻毒素,已经引起了广泛的关注。MCs除具有典型的肝毒性外,还具有免疫毒性。笔者主要从免疫器官的病理变化、免疫细胞、免疫相关酶以及基因等方面综述了MCs对鱼类免疫毒性的研究现状,进而系统梳理了MCs对鱼类的免疫毒性作用机制,可为有效预警环境中MCs的潜在风险提供支持。     

农作物中微囊藻毒素的富集、危害及食用风险研究进展

微囊藻毒素（microcystins, MCs）是最受关注的一种蓝藻毒素,其可对肝脏产生伤害,具有急性肝毒性作用,长期摄入可引发肝癌。除水体和水产品外,MCs还可通过其污染的灌溉水富集在农作物中,增加人群的食用风险。本文系统概述了微囊藻毒素在不同农作物中的富集情况及其对农作物的毒性作用,同时评价了农作物可食用部分残留的MCs对人类健康的潜在危害。     

Toxicity and bioaccumulation of lead and cadmium in marine protozoan communities

The behavior of lead and cadmium in a protozoan community was studied in order to obtain new data regarding the toxicity and bioaccumulation of these heavy metals. For this purpose, microcosms with different concentrations of the pollutants (without metals, 500 microg Cd and Pb x L(-1) 1,000 microg Cd and Pb x L(-1)) were used. Protozoans bioaccumulated 7.03-207.00 microg Pb x g(-1) dry weight (dw) and 0.05-332.75 microg Cd x g(-1) dw, representing an accumulation capacity of up to 161.45 microg Pb x g(-1) dw and 310.75 microg Cd x g(-1) dw more than that of the bacteria. The addition of both metals caused a significant reduction in the density of protozoans. These data were compared with those obtained previously in treatments that used these metals separately.     

Toxicity and Bioaccumulation of Cadmium in Marine Protozoa Communities

The behavior of cadmium in a protozoan community was analyzed in order to obtain new data concerning the toxicity and bioaccumulation of this heavy metal. For this purpose, microcosms with different concentrations of the pollutant (without cadmium, 500 microg Cd.l-1 and 1000 microg Cd.l-1) were used. Protozoans bioaccumulated 8. 74-283 microg Cd.g-1 dry weight, representing an accumulation capacity of 15.53-69.59 times more than that of bacteria. The addition of cadmium caused a significant reduction in protozoan density, whereas bacterial abundance was not affected.     

藻毒素免疫抗原的制备及鉴定

目的为建立藻毒素(MCLR)免疫学检测方法,制备具免疫功能的MCLR完全抗原。方法根据MCLR分子中的羧基和蛋白质分子中的氨基,利用“活泼酯法”和“碳二亚胺法”分别制备MCLRKLH(匙孔血蓝蛋白)免疫抗原和MCLRBSA(牛血清白蛋白)检测抗原。结果用紫外光谱法(UV)和Bradford蛋白含量测定法鉴定,结合物中MCLR与KLH、BSA的结合摩尔比为9.1∶1和9.4∶1。采用“皮下注射法”用MCLRKLH免疫新西兰大白兔15周,取血清,用“间接酶联免疫吸附法”(id-ELISA)鉴定抗MCLR多克隆抗体效价,最高达1∶25600。结论证明制备的MCLRKLH具有免疫性。     

Toxic effects and bioaccumulation of cadmium in the aquatic oligochaete Tubifex tubifex

Although Tubifex tubifex (Oligochaeta, Tubificida) has been proposed as a test organism for ecotoxocological studies, very few data concerning sublethal toxicity and bioaccumulation are available on this worm. The aims of this work were to assess the toxicity of cadmium, one of the most toxic metals frequently encountered in polluted areas, on T. tubifex and the ability of the worm to accumulate this metal. Acute toxicity was analyzed by measurement of the 96-h LC(50) and daily survival rates. Results indicated that T. tubifex undergoes an adaptation period to Cd, the duration of which decreases with increasing Cd concentration. The various parameters affecting toxicity are discussed. Sublethal toxicity was studied by scanning electron microscopy. Observations revealed that Cd induced autotomy of the caudal region and mucus production. Autotomy is proposed as a criterion for sublethal toxicity. The results of bioaccumulation studies revealed that Cd is highly and rapidly taken up by the worm, suggesting involvement of efficient detoxification mechanisms. Consequently, the ability to accumulate large amounts of Cd may represent a potential toxicological risk to predators of the worm if Cd is accumulated in bioavailable forms.     

上海市淀山湖水质富营养化状况及常见水生生物体内微囊藻毒素水平

[目的]对上海市青浦区2013年淀山湖水质富营养化状况和微囊藻毒素(MC)污染进行评估。[方法]于2013年3—9月间在环淀山湖周边依据地理位置和功能区分布特点设立5个水质监测点,进行水质和生物采样检测,每月监测1次,涵盖丰水期、平水期和枯水期。依据GB 3838—2002《地表水环境质量标准》中地表水Ⅲ类标准对结果进行评价。[结果]质浊度监测均值为10.73 NTU。p H和化学耗氧量、氨氮的监测均值分别为8.38和4.98、0.82 mg/L,达到标准;总氮、总磷监测均值分别为2.98、0.17 mg/L,超过标准限值;各指标最大值均超过标准限值。不同月份间水质差异均有统计学意义。湖区水生生物体内MC-LR、MC-RR监测期均值为7.02、10.14μg/kg;3—7月以MC-RR为主,8—9月以MC-LR为主;河蚌和螺蛳检出频率较高,鲢鱼和鲫鱼蓄积毒素浓度最高,分别为25.1、21.4μg/kg。[结论]淀山湖水质为中度富营养化,湖区生物体内有一定藻类毒素蓄积。     

氯酚在鲫鱼体内的分布、存在形式与生物富集研究

用气相色谱－电子捕获检测器法测定鱼组织中４种有代表性的氯酚（ＣＰｓ）及其共轭物。选取ＣＰｓ分别对鲫鱼在室温（２２±５）℃进行９６ｈ半静态染毒实验。实验发现：２４ｈ换一次水,能充分保证ＣＰｓ实验水的浓度恒定,鱼的存在并不影响实验水的浓度。实验水系统中,ＣＰｓ在鲫鱼（Ｃｒｕｉｃａｎｃａｒｐｓ）体内的分布和积累的研究结果表明,ＣＰｓ在鱼体内以游离ＣＰｓ及其共轭物２种形式存在。ＣＰｓ总量在各鱼组织间的分布顺序为：胆＞肝、肾＞肌肉,随着氯（Ｃｌ）原子数目的增多,ＣＰｓ共轭物所占比例亦增大,而ＰＣＰ共轭物所占比例则较ＴＣＰ有所下降。胆组织中ＣＰｓ共轭物由葡萄糖苷酸共轭物和硫酸酯共轭物２种形式组成,其中葡萄糖苷酸含量大于９３％。通过计算生物浓缩因子（ＢＣＦ）值来度量ＣＰｓ在鱼组织中的生物富集效果。由胆中游离氯酚和硫酸酯共轭物得到的ＢＣＦ值均与正辛醇／水体系的分配系数ＫＯＷ没有相关性;而通过葡萄糖苷酸共轭物和ＣＰｓ总量分别计算得到的ＢＣＦ值均与ＫＯＷ有较好的相关性,（ｒ＞０．９６）。鲫鱼鱼胆的ＢＣＦ,在２．０×１０３～６．３×１０３之间。     

东海加工用河鲀鱼种毒性研究

应用酶联免疫方法，对分布于中国东海，应用地加工河豚鱼干制品的五种主要河鱼种毒性进行了调查研究。毒素含量范围为＜４．０×１０－２＞１．０×１０４ＭＵ／ｇ。即使处于繁殖期，暗鳍、淡鳍腹刺仍均属无毒或弱毒级。头纹宽吻和横纹东方则具有相当大的毒性。毒素含量随其生活的环境、海域及季节变化。建议在监督控制下，批准部分具备条件的企业进行河鱼干制品的加工生产，但应明确限制允许加工的腹刺属鱼种     

壬基酚对红鲫、草鱼和鲢鱼的毒性及组织蓄积研究

目的了解不同鱼种对壬基酚的毒性差异。方法选择红鲫、草鱼和鲢鱼鱼苗,4-壬基酚换水式染毒进行96h急性毒性试验、12周亚慢性毒性试验、外周血红细胞微核试验,高效液相色谱法测定组织中4-壬基酚。结果①4-壬基酚对红鲫、草鱼和鲢鱼的96h LC50分别为251.30、155.84和187.01μg/L。②染毒12周,红鲫高剂量组肝胰脏系数降低,中、高剂量组卵巢系数增高(P<0.05);草鱼中剂量组肾脏系数降低(P<0.05);鲢鱼高剂量组肝胰脏系数降低(P<0.05)。③染毒4周时,红鲫和鲢鱼中、高剂量组及草鱼高剂量组微核细胞率与对照组相比显著增高(P<0.05);染毒8周及以后,受试鱼各剂量组微核细胞率均增高(P<0.05);④受试鱼肌肉、脑和肝胰脏等组织样品中均有4-壬基酚检出,其中肝胰脏的生物浓缩系数最高;红鲫对4-壬基酚的生物浓缩系数高于草鱼和鲢鱼。结论红鲫对壬基酚较敏感。     

Toxicity and bioaccumulation of cadmium in Chlorella.

Chlorella pyrenoidosa cultures grown at pH 7 in the presence of 0, 0.25, 0.50, and 1.00 mg of Cd/liter had doubling times of 11, 21, 22, and 35 hours, respectively, whereas similarly exposed cultures grown at pH 8 had doubling times of 11, 16, 17, and 25 hours, respectively. C. pyrenoidosa is capable of concentrating cadmium, and the amount accumulated is directly proportional to the concentration of metal present initially and is dependent upon the pH of the medium. No accumulation occurs in the dark, at 4°C, or in dead cells. Cadmium accumulation is not affected by the concentration of calcium, magnesium, molybdenum, copper, zinc, or cobalt in the growth medium, whereas a level of manganese equal to 0.20 mg/liter completely blocks cadmium accumulation; iron may also play a role in regulating cadmium accumulation. Cells which had accumulated cadmium could still fix atmospheric CO₂, albeit at reduced rates; O₂ evolution was also inhibited, but to a lesser extent. The ability of C. pyrenoidosa to accumulate large concentrations of cadmium before showing adverse effects may be related to the presence of cadmium-sequestering agent(s) within the cell. The concentration of cadmium by C. pyrenoidosa could pose a hazard to the freshwater food chain.     

Toxicity and antimicrobial effect of silver nanoparticles in swine sperms

ABSTRACT

Bacterial contamination in swine semen affects the quality and longevity of sperm and consequently fertility is reduced. Antibiotics have been used to prevent bacterial growth, but the frequency of bacterial resistance to various antibiotics are increasing. Silver nanoparticles (AgNPs) of 10–20 nm in size have shown a biocide effect in bacteria and fungi microorganisms without toxicity to certain mammalian cells. The goal of this study was to analyze both, antimicrobial activity against Staphylococcus aureus and toxicity in swine sperms after 10–20 nm AgNPs treatment. S. aureus proliferation decreased when concentrations from 0.4 to 10 mM AgNPs were assayed. Also, sperm viability measured by mitochondrial metabolism after AgNPs treatment up to a concentration of 10 mM, was viable. In addition, viability determined by membrane integrity of sperms showed that AgNPs treatment up to a concentration of 10 mM was safe. Sperm morphology was evaluated by automated quantification of proximal and distal drops and whiptails. Data indicated that AgNPs treatment up to a concentration of 4 mM were harmless. Finally, sperm capacitation and acrosome reactions were determined by (chlortetracycline) CTC assay. Data showed that no changes in sperm capacitation were observed when sperms were treated with 2 mM of AgNPs, but data showed increased calcium mobilization when treated with 10 mM AgNPs, which suggested sperm capacitation. Finally, there were no significant changes encountered on sperm acrosome reaction for any of the treatments after AgNPs treatment. Taken together, these results show the potential of AgNPs as an alternative to conventional antimicrobial agents that are currently used in extenders to preserve semen required for storage.