敌百虫对黄河鲤鱼的急性毒性研究及安全评价

为了弄清楚敌百虫对黄河鲤鱼的急性毒性浓度,在常温条件下用80%的敌百虫(生产制品)对黄河鲤鱼进行急性毒性试验,试验分别设置6个浓度梯度:500 mg/L、601 mg/L、721 mg/L、866 mg/L、1 041 mg/L、1 250 mg/L,观察不同时间的半致死浓度并计算安全浓度。结果表明:黄河鲤鱼对敌百虫24 h、48 h、72 h、96 h的半致死浓度(LC50)分别为818.7 mg/L、774.7 mg/L、719.8 mg/L、719.8 mg/L;安全浓度为208.10 mg/L。     

3种农药对桡足类的急性毒性试验

为评价经济甲壳动物人工饲养过程中桡足类杀除农药的药效,采用常规方法测定3种农药(蛛虫速灭、鱼虫恨、强力混杀精)对桡足类的96 h急性毒性。结果表明,蛛虫速灭在48、72、96 h的LC50分别为0.041、0.017、0.011μL/L;鱼虫恨在24、48、72、96 h的LC50分别为0.286、0.051、0.041、0.036μL/L;强力混杀精在72、96 h的LC_(50)分别为0.026、0.014μL/L;推算得到蛛虫速灭、鱼虫恨、强力混杀精对桡足类的安全浓度范围分别为0.001~0.005μL/L、0.000 40~0.000 48μL/L、0.000 10~0.000 14μL/L;3种农药对桡足类的毒性强弱顺序为:强力混杀精蛛虫速灭鱼虫恨。研究结果为3种农药在甲壳类水产动物人工饲养过程中的科学合理使用提供了参考。     

伊维菌素上调自噬水平抑制犬乳腺肿瘤细胞的增殖

为了探讨伊维菌素对犬乳腺肿瘤细胞的作用及可能机制,本研究采用CCK-8检测不同浓度伊维菌素对犬乳腺肿瘤细胞(CMT 7364,CIPp)增殖的影响;annexinⅤ-FITC/PI双染色检测伊维菌素对细胞凋亡的影响;转染pEGFP-LC3质粒,荧光显微镜下观察伊维菌素对自噬小体形成的影响;Western Blot检测伊维菌素处理后细胞中自噬标志分子LC3Ⅰ、LC3Ⅱ的表达水平。结果发现:伊维菌素可抑制犬乳腺肿瘤细胞的增殖,并呈现时间与剂量依赖性关系,CMT 7364和CIPp细胞24 h的IC_(50)值分别为10.2μmol/L和10.76μmol/L;伊维菌素对细胞凋亡水平影响轻微,12μmol/L处理24 h和48 h后凋亡细胞比例均小于3%,各处理间无统计学差异(P>0.05);伊维菌素可诱导细胞浆内自噬小体的形成,促进LC3Ⅰ向LC3Ⅱ转化,诱导细胞自噬。表明伊维菌素通过诱导犬乳腺肿瘤细胞自噬发挥抗肿瘤作用。     

不同硬度条件下Cu~(2+)对孔雀鱼的毒性研究

为了研究水体在不同硬度条件下Cu2+对孔雀鱼的单一毒性效应,试验以孔雀鱼为试验动物进行研究。试验结果表明:当水硬度为5.88,11.76,23.52 mmol/L时,孔雀鱼24 h半数致死浓度(LC50)为2.61,3.35,4.83 mg/L;48 h时LC50分别为1.58,1.74,2.17 mg/L;96 h时LC50分别为0.66,0.88,1.13 mg/L。可见随着水硬度增加,Cu2+对孔雀鱼的急性毒性作用降低。     

聚维酮碘对黄河鲤鱼急性毒性研究及安全评价

为了确定聚维酮碘对黄河鲤鱼的急性毒性,试验分别设置6个浓度梯度(14 mg/L、16 mg/L、18 mg/L、20 mg/L、23 mg/L、26 mg/L),在常温条件下用聚维酮碘原药对黄河鲤鱼进行急性毒性试验。结果表明:黄河鲤鱼对聚维酮碘24 h、48 h、72 h、96 h的半致死浓度(LC_(50))都为18.8 mg/L,安全浓度为5.6 mg/L。     

硝唑尼特对斑马鱼和赤子爱胜蚓的急性毒性试验

通过对斑马鱼和赤子爱胜蚓的急性毒性试验,研究了硝唑尼特的生态毒性.结果表明,硝唑尼特在静水条件下对斑马鱼24 h LC50为2.312 mg/L、48 h和72 h LC50为2.033 mg/L、96 h LC50为1.968 mg/L,按鱼类急性毒性分级标准,硝唑尼特属高毒类物质;硝唑尼特滤纸法对赤子爱胜蚓24 h...     

3种杀草剂对仿刺参幼参的急性毒性效应

采用静水试验法,在水温(14±1.5)℃,盐度27.9‰,pH 8.1,用乙草胺、灭草松和百草枯三种杀草剂对仿刺参幼参进行急性毒性试验。结果表明:乙草胺对仿刺参在24、48、72和96 h的半数致死量(LC50)分别为11.190 9、5.744 8、4.689 7和3.828 3 mg/L;灭草松对仿刺参在24、48、72和96 h的LC50分别为13.205 9、10.472 3、8.800 3和6.490 8 mg/L;百草枯对仿刺参在24、48、72和96 h的LC50分别为0.386 3、0.222 7、0.164 2和0.128 4 mg/L;乙草胺、灭草松和百草枯对仿刺参幼参的安全质量浓度分别为0.45、1.98和0.02 mg/L。3种杀草剂对仿刺参幼参的急性毒性大小依次为百草枯乙草胺灭草松。     

灭虫精对西施舌幼贝的毒性试验

在静水条件下,进行灭虫精对西施舌幼贝的毒性试验,试验结果显示:灭虫精对西施舌幼贝24 h致死浓度LC100为400 ms／L,半数致死浓度LC100为250 mg/L,安全浓度为2．50mg／L;48h致死浓度为260 mg／L,半数致死浓度LC50为224ms／L,安全浓度为2．24mg／L。灭虫精用于西施舌人工育苗过程中桡足类等敌害生物防治,具有较强的可用性。根据试验结果,建议使用2 mg／L浓度的灭虫精进行防治,可达到显著效果。     

四种抗菌药物对鲫鱼苗的急性毒性试验

在水温22℃~25℃条件下,选取来源一致、规格齐整、健康无病,体重4 g±0.2 g鲫鱼苗,用培氟沙星、氟苯尼考、甲砜霉素、痢菌净4种抗菌药对鲫鱼苗进行急性毒性试验。确定每种药物在不同时间对鲫鱼苗的半致死浓度(LC50),并求出4种药物相应的安全浓度(SC)。结果显示,4种药物对鲫鱼苗24 h的LC50分别为1 935.981、314.141、265.031、35.46 mg/L;48 h的LC50分别为1 863.621、154.231、177.05、130.53 mg/L;96 h的LC50分别为1 840.011、129.54、1 121.59、126.57 mg/L,SC分别为538.19、304.13、328.563、7.73 mg/L。表明培氟沙星、氟苯尼考和甲砜霉素对鲫鱼可安全使用,痢菌净毒性较大,应谨慎使用。     

毒死蜱对家蚕的急性毒性研究

在室内不同条件下进行了桑园杀虫剂毒死蜱对家蚕的急性毒性试验,结果表明:毒死蜱对2~5龄家蚕幼虫的摄入LC50值(48 h,25℃)分别为1.11、1.73、3.48与4.12 mg/L;在20、25、30、35℃下,毒死蜱对3龄家蚕的LC50值(48 h)分别为1.70、1.80、0.49与0.40 mg/L;桑叶浸药时间为1 s、10 s、1 m in、10 m in与1 h时,毒死蜱对4龄家蚕幼虫的LC50值(48 h,25℃)分别为5.55、3.64、3.15、2.12与1.54 mg/L;家蚕幼虫在毒死蜱药膜上爬行1、10、30与60 m in后,毒死蜱对3龄家蚕的接触LD50值(48 h,25℃)分别为3.59、0.28、0.20、0.12μg/cm2。     

三种药物对西施舌稚贝的急性毒性研究

在常温静水条件下,进行敌百虫、甲醛和鳗菌净对西施舌稚贝的急性毒性试验。结果表明:敌百虫、甲醛和鳗菌净对西施舌稚贝的24hLC50分别为26.75mg/L、54.25mg/L、1.47mg/L,其安全浓度分别为0.27mg/L、0.54mg/L、0.01mg/L。本文探讨如何有效地使用药物杀灭西施舌稚贝的敌害生物,以保证西施舌人工育苗成功。     

稻田杀虫剂三唑磷对家蚕的触杀作用与摄入慢性毒性的研究

为减轻水稻与桑树混栽地区农药污染给蚕业生产造成的损失,进行了稻田杀虫剂三唑磷对家蚕的室内毒性试验。结果表明,采用点滴法与药膜法,25℃条件下药剂处理后96 h,三唑磷对家蚕2龄幼虫的接触LD50值分别为0.015μg/头与1.41μg/cm2。2龄起蚕开始,于25℃条件下用三唑磷处理的桑叶饲养,在药剂处理后24、48 h以及3龄起、4龄起、5龄起,三唑磷对家蚕的LC50值分别为2.38、1.54、0.97、0.74、0.53 mg/L。采用食下毒叶法试验,三唑磷对家蚕生长发育与结茧的最大无作用浓度约为0.04 mg/L。     

结肠小袋纤毛虫体外药物急性毒杀试验

通过结肠小袋纤毛虫对甲硝唑、氟苯尼考和血虫净（三氮咪）的急性毒性试验,以机率单位法获得半数致死浓度（LC50）,结果显示：甲硝唑、氟苯尼考对结肠小袋纤毛虫2h的半数致死浓度（LC50,2h）分别是457．8mg／L,1705mg／L,12h的半数致死浓度（LC50,12h）分别是25．64mg／L、973．8mg／L。血虫净（三氮咪）12h和24h半数致死浓度（LC50）分别是331．8mg／L、295．4mg／L。甲硝唑是杀灭结肠小袋纤毛虫的理想药物。     

Toxicity of Ammonia and Nitrite to Sunshine Bass in Selected Environments

Abstract

The effects of environmental calcium and salinity on toxicities of ammonia and nitrite for sunshine bass (female Morone chrysops × male M. saxatilis) were investigated, and the effects of pH, sodium chloride, and calcium chloride on uptake and depuration of ammonia and nitrite were characterized. The concentration of un-ionized ammonia-nitrogen (UIA-N) lethal to 50% of the fish within 96 h (96-h LC50) ranged from 0.32 to 0.60 mg/L and increased significantly with increased concentration of environmental calcium over the range tested (5–80 mg/L). The acute toxicity of UIA-N was not affected by salinity over the range tested (1–24 g/L), and the 96-h LC50 was 0.70 ± 0.04 mg UIA-N/L (mean ± SE) over all salinities tested. The rate and degree of ammonia uptake was greater at elevated environmental pH. Environmental pH did not affect the rate of depuration of ammonia. Environmental calcium did not affect nitrite toxicity, and the 96-h LC50 of nitrite-nitrogen (nitrite-N) was 12.8 ± 1.6 mg/L (mean ± SE) over all calcium concentrations tested. The 96-h LC50 of nitrite-N for fish acclimated to a salinity of 1 g/L was 35.0 ± 2.3 mg/L (mean ± SE), whereas LC50s of nitrite-N for fish acclimated to salinities of or higher than 8 g/L were greater than 100 mg/L (the highest exposure level). The addition of chloride to freshwater environments reduced the accumulation of nitrite in the plasma. Chloride was more effective in reducing the accumulation of nitrite in the plasma when added as calcium chloride rather than as sodium chloride. This study indicates that sunshine bass are relatively sensitive to both ammonia and nitrite. Tolerance to ammonia can be increased in freshwater environments by increasing calcium levels or decreasing environmental pH. Tolerance to nitrite can be increased by addition of chloride to freshwater environments or through the use of saltwater environments.     

四种中药对结肠小袋虫半数致死浓度的测定

利用机率单位法测定了常山、五倍子、乌梅和二花水提取物对结肠小袋虫的半数致死浓度.结果表明,常山、五倍子、乌梅和二花抗结肠小袋虫2h半数致死浓度(LC50)分别是13.40、12.22、19.02、43.34g/L;6 h的LC50分别是12.80、5.824、7.619、23.32 g/L;12 h的LC50分别是8....     

Molluscicidal activity of Carica papaya and Areca catechu against the freshwater snail Lymnaea acuminata

The molluscicidal activity of seed and lyophilized latex powder of Carica papaya and seed powder of Areca catechu against the vector snail Lymnaea acuminata was studied. The toxicity of these plant products was time and dose dependent. The toxicity of C. papaya lyophilized latex powder (LC(50) at 96 h: 8.38 mg/l) was more pronounced than that of A. catechu seed powder (LC(50) at 96 h: 12.32 mg/l) and C. papaya seed powder (LC(50) at 96 h: 61.56 mg/l). Ethanolic extracts of C. papaya seed and A. catechu seed were more toxic than their other extracts. The ethanolic extract of A. catechu seed (LC(50) at 24h: 17.21 mg/l) was more effective than the ethanolic extract of C. papaya seed (LC(50) at 24h: 53.38 mg/l). The LC(50) of column-purified fraction of A. catechu seed at 96 h was 3.99 mg/l, whereas that of C. papaya seed was 7.06 mg/l. C. papaya and A. catechu may be used as potent molluscicides since the concentrations used to kill the snails were not toxic for the fish Colisa fasciatus which shares the same habitat with the snail L. acuminata.     

草甘膦与氰氟草酯对隆线溞的急性毒性研究

在水生食物链中,水溞是连结植物、微生物和动物的关键成员。草甘膦与氰氟草酯被广泛用于防除水生和稻田杂草,研究它们对水溞的毒性,有益于人们关注使用除草剂对水体生态系统的影响。试验以标准水体监测生物——隆线溞(Daphnia carinata)单克隆为材料,研究草甘膦和氰氟草酯对其泳动能力、存活率和趋光性的影响。结果表明,两种除草剂对隆线溞均有明显毒性,草甘膦对隆线溞24, 48和96 h的半致死浓度(LC₅₀)分别为66.58, 29.60和12.33 mg/L,为田间常规用药量的0.15%~0.81%;氰氟草酯对隆线溞24, 48和96 h的LC₅₀依次是63.15, 51.91和34.41 mg/L,为田间常规用药量的17.21%~31.58%。两种除草剂显著影响隆线溞的泳动能力和趋光指数。隆线溞接触草甘膦和氰氟草酯3 h后,导致其趋光指数显著改变的浓度分别是4.59和14.20 mg/L,分别为常规用药量的0.06%和7.10%。因此,草甘膦和氰氟草酯对水溞的毒性大,对水生食物链的影响不可忽视。利用水溞趋光性可快速、灵敏地监测除草剂使用后的水体生物毒性。     

Anthelmintic and cytotoxic activities of extracts of Markhamia obtusifolia Sprague (Bignoniaceae)

The anthelmintic activity of Markhamia obtusifolia Sprague (Bignoniaceae) leaf extracts was evaluated against the ruminant gastrointestinal nematode parasite Trichostrongylus colubriformis (Nematoda: Strongylida) using the in vitro egg hatch test. Also, the cytotoxic activity of aqueous extracts of M. obtusifolia was evaluated in cell line cytotoxicity assays. The results indicated that the effective concentration (EC(50)) for the water extract of M. obtusifolia leaves (0.46 mg/mL; Confidence Interval [CI] 0.3-0.5mg/mL) was significantly lower than the EC(50) for the acetone extract of M. obtusifolia (0.8 mg/mL; CI 0.7-1mg/mL). Aqueous extracts were twice as potent as the acetone extracts. The EC(90) (0.2mg/mL; CI 0.1-0.02) for thiabendazole (positive control) was significantly lower than the EC(90) for the water extract of M. obtusifolia (10.7 mg/mL; CI 8.3-13.7 mg/mL). In the cytotoxicity bioassay, the lethal concentration (LC(50)) for the aqueous extract of M. obtusifolia was 0.476 mg/mL, which was relatively high (low toxicity) in comparison to the highly toxic berberine (LC(50)=9.80 μg/mL). The current study showed that M. obtusifolia plant extracts possess anthelmintic activity and are relatively non-cytotoxic, thus providing support for their use in traditional veterinary practices.