五氯酚对大型水蚤的急性亚慢性和慢性毒性

本文采用换水式试验研究了五氯酚对大型水蚤的急性、亚慢性和慢性毒性,稀释水硬度为８０－１００ｍｇ／Ｌ。急性和慢性试验均使用小于一日龄的幼水蚤,试验温度为２５－２６℃,慢性试验进行了２０ｄ。用小于一日龄幼水蚤进行的亚慢性试验暴露了１９ｄ,而用四日龄幼水蚤的亚慢性试验则进行了１６ｄ,水温均保持在１９－２０℃。ＰＣＰ对大型蚤的２４ｈ和４８ｈＥＣ５０分别是４８９和２４５μｇ／Ｌ。依据第１胎所产幼水蚤数求得的     

新生期注射纳洛酮和脑啡肽对幼年大鼠分辨学习的影响

本文用Ｓｐｒａｑｕｅ－Ｄａｗｌｅｙ大鼠为实验动物,从生后一日龄起每日皮下分别注射１次纳洛酮（１０,５０,１００,２００μｇ／１００ｇｂ．ｗ）、甲硫氨酸脑啡肽（ＭＥＫ）（２０μｇ／１００ｇｂ．ｗ）,对照组注射等量的生理盐。连续注射１４ｄ,观察１６日龄幼鼠的吸乳迷津分辨学习（ＡＤＬ）、３０日龄幼鼠的Ｙ迷津明暗分辨学习（ＢＤＬ）行为与４５日龄幼鼠前脑蛋白含量的变化,结果表明,５０μｇ／１００ｇｂ．ｗ纳洛     

稀有鮈鲫──一种新的鱼类毒性试验材料

本文研究了稀有鲫（Ｇｏｂｉｏｃｙｐｒｉｓｒａｒｕｓ）作为毒性试验材料的可行性。采用换水式试验,在硬度为２００ｍｇ／Ｌ（以ＣａＣＯ３计）、ｐＨ７．８±０．２、温度２４－２５℃条件下研究了铬、铜、锌和五氯酚（ＰＣＰ）对稀有鲫的急性毒性。重铬酸钾对２日龄稀有鲫的２４ｈ和９６ｈ和ＬＣ５０控制范围分别２６３．６－３３４．７和１１５３－１７８．５ｍｇ／Ｌ（ｎ＝８）。铬、铜、锌和五氯酚对２日龄稀有鲫的急性毒性值（９６ｈＬＣ５０）范围,从铜的５２．２μｇ／Ｌ到铬的５２０００μｇ／Ｌ,毒性大小的顺序是铜＞五氯酚＞锌＞铬。研究结果表明,稀有鲫有可能发展成为一种较为理想的毒性试验材料。     

慢性缺氧大鼠肺动脉内皮依赖性舒张反应与内皮结构的动态变化

本实验对慢性减压缺氧（５０００ｍ）过程中肺动脉ＡＣｈ内皮依赖性舒张反应作了动态观察,并结合分析了其与内皮超微结构和肺动脉压演变的关系。结果表明,缺氧３─２１ｄ,平均肺动脉压（ｍＰＡＰ）显著递增（Ｐ＜０．０５─０．００１）,而缺氧４０ｄ组基本与缺氧２１ｄ组持平,未再进一步升高。缺氧１ｄ组,各ＡＣｈ浓度（１０－１０、１０－９、１０－７、１０－６、１０－５ｍｏｌ／Ｌ）引起的内皮依赖性舒张反应明显受抑（Ｐ＜０．０５─０．００１）。缺氧７ｄ组,舒张反应的受抑程度与缺氧１ｄ组基本相同;但ＡＣｈ１０－５ｍｏｌ／Ｌ引发的反应则较缺氧１ｄ时更弱。缺氧２１ｄ和４０ｄ组,ＡＣｈ１０－６和１０－５ｍｏｌ／Ｌ引起的舒张反应,尽管仍显著低于对照,但却基本上高于缺氧１ｄ和７ｄ组。其余各浓度ＡＣｈ引发的反应则已趋于恢复至对照水平。电镜观察,缺氧１─１４ｄ肺动脉内皮呈逐渐加重的水肿变性;缺氧２１─４０ｄ内皮水肿消失,代之出现渐趋活跃的内皮增生。结果提示,随缺氧时间延长,因内皮从损伤逐渐加重到出现代偿适应,可能存在相应的内皮舒张因子由释放减少到有所恢复的动态变化过程,并对整体肺动脉压有一定程度的影响。     

眼镜蛇神经毒素的急性毒性实验研究

目的　研究眼镜蛇神经毒素 （ Ｃｏｂｒａ ｎｅｕｒｏｔｏｘｉｎ, Ｎ Ｔ） 的急性毒性和蓄积毒性。方法　测 Ｎ Ｔ 对小鼠的 Ｌ Ｄ５０ ; 对大鼠、狗的１ 次性最小中毒剂量和最大安全剂量; 计算 Ｎ Ｔ 在小鼠、狗体内的２４ｈ 蓄积率。结果　 Ｎ Ｔ 经静注、肌注、腹腔、皮下 ４ 种途径给药对小鼠的 Ｌ Ｄ５０ 分别是 （１９５±９５） μｇ／ｋｇ、（１５６±８５） μｇ／ｋｇ、（１５１±１９） μｇ／ｋｇ、（１８４±８５） μｇ／ｋｇ, 对小鼠的最小致死剂量为９７５μｇ／ｋｇ。 Ｎ Ｔ 对大鼠、狗的１ 次性中毒剂量分别为５４μｇ／ｋｇ 和３４μｇ／ｋｇ。对小鼠、大鼠和狗的安全剂量分别为８１５μｇ／ｋｇ、４２μｇ／ｋｇ和３０μｇ／ｋｇ, 分别约为人临床用剂量 （７０μｇ／５０ｋｇ·ｄ－ １ ） 的５８２、３０ 和２１ 倍。 Ｎ Ｔ 在小鼠、狗体内的２４ｈ蓄积率分别为 ５７％ 和３０％ 以上。结论　 Ｎ Ｔ 在使动物中毒的剂量下有广泛的安全范围; Ｎ Ｔ 在动物体内存在弱蓄积毒性。     

甘蓝型油菜胞质体大量制备技术的研究

用Ｐｅｒｃｏｌｌ密度梯度离心法和吖啶橙（ＡＯ）结合光照处理两种方法,均从甘蓝型油菜下胚轴原生质体制备到胞质体。在２个Ｐｅｒｃｏｌｌ梯度、３００００ｇ（１８０００ｒ／ｍｉｎ）与１２℃离心６０ｍｉｎ的条件下,获得了含胞质体８０％以上的群体;以含８０、１００、１２０ｍｇ／Ｌ ＡＯ的酶液酶解下胚轴原生质体,纯化后分别给以３ｈ、２ｈ、１ｈ光照（光强度：４０００ｌｘ）可使原生质体几乎不能分裂,但保持５ｄ以上的     

人铜锌超氧化物歧化酶cDNA的克隆,测序及表达

用逆转录聚合酶链反应（ＲＴＰＣＲ）,以人胎肝组织总ＲＮＡ为模板,扩增了人铜锌超氧化物歧化酶（ｈＣｕ,ＺｎＳＯＤ）的ｃＤＮＡ,并进行序列分析,将该ｈＣｕ,ＺｎＳＯＤｃＤＮＡ重组到Ｔ７启动子控制下的分泌型表达载体ｐＥＴ２２ｂ（＋）中,构建表达质粒ｐＥＴＳＯＤ,并转化大肠杆菌ＢＬ２１（ＤＥ３）。ＳＤＳＰＡＧＥ及蛋白质印迹分析表明,经１ｍｍｏｌ／Ｌ异丙基硫代βＤ半乳糖苷（ＩＰＴＧ）诱导后,可高效表达一分子量为１９ｋＤ的蛋白质,与抗人ＳＯＤ多抗有特异的免疫反应,表达量约为菌体总蛋白质的３０％,具有特异性ＳＯＤ酶活性,酶活力可达１７９７ｕ／ｍｌ培基。     

用无血清培养基在填充床生物反应器生产 rHuEPO

在填充床生物反应器用含５％ＦＢＳ的ＤＭＥＭ：Ｆ１２培养基培养产重组人促红细胞生成素（ｒＨｕＥＰＯ）的细胞Ｃ_２８～１０ｄ后,使用自制的无血清生产培养基（ＳＦＭｐ）生产ｒＨｕＥＰＯ。ＳＦＭｐ培养基既能维持细胞生长,又能生产ＥＰＯ,也便于纯化分离ｒＨｕＥＰＯ。使用填充床生物反应器培养细胞,能维持培养２０～２５ｄ,ｒＨｕＥＰＯ表达水平达１２～２８.４ｍｇ／Ｌ之间,反应器的产率达到７１.０ｍｇ／Ｌ／ｄ,比滚瓶的产率增加１２～１４倍。葡萄糖最高消耗量达到２１ｇ／Ｌ／ｄ,细胞培养密度最高达到３.０×１０^７／ｍｌ以上,每次可收无血清培养上清８０～８７Ｌ。由于细胞被固定在聚酯片上,培养上清中脱落细胞很少。观察了反应器的乳酸和氨的含量,其结果表明乳酸和氨含量分别低于３.５ｇ／Ｌ和５ｍｍｏｌ／Ｌ,不影响产物的表达。经过多批培养和生长ｒＨｕＥＰＯ的结果表明,自行配制的ＳＦＭｐ培养基在该反应器能有效地维持细胞生长和生产ｒＨｕＥＰＯ。     

自絮凝酵母颗粒连续发酵生产酒精的新工艺

用既有优良酒精发酵性能,又具有强自絮凝能力的融合酵母株ＳＰＳＣ,在单釜有效容积为１０ｍ３的四釜并联气升环流悬浮床生物反应器系统中,进行了连续发酵生产酒精的研究。以玉米为原料,双酶法制糖,过滤得到清糖液作为底物,在稀释速率为０１／ｈ的条件下,终点发酵液中酒精浓度为７０～８０ｇ／Ｌ,残余还原糖和残余总糖分别为２～３ｇ／Ｌ和３～５ｇ／Ｌ,悬浮床反应器的设备生产强度达到７～８ｇ（ＥｔＯＨ）／（Ｌ·ｈ）。     

渗透胁迫下2，4─D和乙烯利（CEPA）对玉米叶片延伸生长的生物物理参数的影响

２０ｍｇ／Ｌ２．４─Ｄ和４００ｍｇ／ＬＣＥＰＡ分别不同程度地促进和抑制玉米叶片的延伸生长（ＬＥＲ）,随胁迫时间延长,２,４─Ｄ处理的ＬＥＲ下降迅速,ＣＥＰＡ处理的ＬＥＲ下降缓慢。２,４─Ｄ和ＣＥＰＡ的施用分别不同程度地提高和降低了ＬＥＲ对相对含水量（ＲＷＣ）、水势、渗透势的敏感性。膨压与ＬＥＲ的相关性较小。随胁迫时间延长,干旱对照的细胞壁屈服阈值（Ｙ）呈一定下降趋势,但变化不大,２,４─Ｄ和ＣＥＰＡ处理的Ｙ值则呈一定的波动;而细胞壁的伸展性（ｍ）则明显下降,胁迫７２ｈ前,ｍ与ＬＥＲ变比规律一致,表明２,４─Ｄ和ＣＥＰＡ对生长的调控主要是通过调节ｍ来实现的。     

Distribution of cadmium and lead in a stream ecosystem

Cadmium and lead were detected in all components of the stream that were examined. Cadmium was present in similar concentrations in both fishes and sediments. Aquatic insects, however, exhibited higher concentrations of cadmium than did sediments. Lead concentrations in sediments and aquatic insects were similar, but higher than concentrations in fishes. Snails contained the highest level of lead and had noticeably greater amounts of the metal than did aquatic insects. In general, concentrations of both metals increased successively from water to fish to sediments to aquatic invertebrates.     

吸烟对男性生殖和遗传毒性的研究进展

吸烟作为一个社会问题受到广泛关注,目前研究认为吸烟可对生殖系统存在有害影响。从吸烟对睾丸功能、精液质量、生殖内分泌功能的影响及吸烟对生殖细胞的遗传毒作用几个方面,总结了近几年国内外有关吸烟对男性生殖与遗传毒性研究进展,为进一步研究吸烟的生殖毒性提供参考。     

Survival and Reproduction of Some Nematodes as Affected by Muck and Organic Acids

Fulvic, humic, acetic, N-bulyric, formic, lactic, and propionic acids were inhibitory to the survival or reproduction of Aphelenchus avenae, Aphelenchoides goodeyi, Helicotylenchus pseudorobustus, Meloidogyne hapla or Xiphinema americanum. Reproduction of H. pseudorobustus and M. hapla significantly increased with increasing amounts of muck added to sand, and with the initial amount of nematode inoculum. All acids except humic and fulvic were lethal, in vitro, to all nematode species tested. When A. goodeyi was treated with fulvic acid, reproduction was reduced significantly when compared with sodium humate or water treatments. Treatment of H. pseudorobustus with fulvic acid (pH 3.5) resulted in a greater reduction in reproduction in soil than did treatment with humic acid (pH 3.5).     

Influence of maternal stress on metal-induced pre- and postnatal effects in mammals

Studies in rodents have shown that, during pregnancy, maternal stress from restraint, noise, light, and heat among other factors may be associated with adverse effects on embryo/fetal and postnatal development. Moreover, it is also well known that exposure to certain metal levels during gestation can also cause maternal and developmental toxicity. Because potentially, pregnant women may be concurrently exposed to metals and various types of stress, the influence of maternal stress on the metal-induced adverse pre-and postnatal effects has been investigated for a number of elements. This influence is reviewed here. It is concluded that maternal stress enhances the metal-induced embryo/fetal and developmental toxicity only at doses of the metal which are also clearly toxic to the dam.     

乙腈的水生态基准

本文参照美国国家环保局推荐的“推导保护水生生物及其用途的国家水质基准的技术指南”,根据我国水生生物区系特点,通过水生生物毒性试验研究和制定石油化工废水中重要污染物—乙腈的水生态基准。试验动物涉及到4个门、6个纲、8个科、13属和13个种。文中根据乙腈对13种水生动物的急性毒性试验,对水生动物的慢性毒性试验以及对水生植物浮萍的生长抑制试验,推导出乙腈的基准连续浓度为413mg／L,基准最大浓度为1145mg／L。     

Commentary on the Role of Maternal Toxicity on Developmental Toxicity

Maternal mammalian toxicity impacts prenatal development, with general systemic maternal toxicity, from reduced weight gain to morbidity, causative for reduced fetal weights/litter and increased fetal variations (especially skeletal)/litter, but not, in the author's opinion, for increased fetal malformations, reduced litter sizes or full litter losses. Increased fetal malformations are likely due to exposure to specific chemicals which alter specific maternal functions at critical point(s) in pregnancy, typically exaggerated effects from higher doses by drugs under development with known, desired pharmacological effects. Malformations can also be from genetic/epigenetic alterations, specific altered proteins, molecular pathways, etc. Full litter losses are triggered by the mother and are rare in rats. Information to inform maternal (and developmental) toxicity includes ovarian corpora lutea counts, uterine implantation profile, degree of litter reduction (if present), timing and extent of maternal toxicity relative to those of adverse embryofetal effects, etc. The view of maternal toxicity as confounding results in in vivo developmental toxicity studies, worldwide concerns about increased research animal usage, increasing time, labor, costs, and new software and hardware sophistication all drive the interest in development, validation, and performance of in vitro/in silico assays. These assays are fast, inexpensive, responsive to animal use concerns and amenable to mechanistic questions. The strength of these in vitro/in silico assays is considered by many to be the absence of the maternal organism/placenta. These assays inform mechanism and hazard, but NOT risk. The Environmental Protection Agency currently estimates that these new assays are approximately 70% accurate versus the whole animal tests.     

伊维菌素搽剂的毒理学研究

目的　研究放线菌属产生的阿凡曼菌素 Ｂ１ 的衍生物伊维菌素（ Ｉｖｅｒｍ ｅｃｔｉｎ） 搽剂皮肤用药的急性和长期毒性作用。方法　观察给予正常皮肤和破损皮肤动物一次性或长期经皮给药产生的毒性反应。结果　以２６７ｍ ｇ／ｋｇ 大剂量的伊维菌素经皮给药 ２４ｈ 后出现震颤、运动失调等中毒症状, ７２ｈ 后症状消失; 以１００ｍ ｇ／ｋｇ 经皮给药 ４５ 天后无明显的毒性。结论　大剂量 （２６７ ｍ ｇ／ｋｇ） 的伊维菌素经破损皮肤给药可致动物急性中毒, 较大剂量 （１００ ｍ ｇ／ｋｇ） 长期皮肤用药无明显的毒性作用。     

Rhizotoxicity of aluminate and polycationic aluminium at high pH

Although monomeric Al species are often toxic in acidic soils, the effects of the aluminate ion (Al(OH) ₄ ⁻ ) on roots grown in alkaline media are still unclear. Dilute, alkaline (pH 9.5) nutrient solutions were used to investigate the effects of Al(OH) ₄ ⁻ on root growth of mungbean (Vigna radiata L.). Root growth was reduced by 13% after 3 d growth in solutions with an Al(OH) ₄ ⁻ activity of 16 μM and no detectable polycationic Al (Al₁₃). This decrease in root growth was associated with the formation of lesions on the root tips (due to the rupturing of the epidermal and outer cortical cells) and a slight limitation to root hair growth (particularly on the lateral roots). When roots displaying these symptoms were transferred to fresh Al(OH) ₄ ⁻ solutions for a further 12 h, no root tip lesions were observed and root hair growth on the lateral roots improved. The symptoms were similar to those induced by Al₁₃ at concentrations as low as 0.50 μM Al which are below the detection limit of the ferron method. Thus, Al(OH) ₄ ⁻ is considered to be non-toxic, with the observed reduction in root growth in solutions containing Al(OH) ₄ ⁻ due to the gradual formation of toxic Al₁₃ in the bulk nutrient solution resulting from the acidification of the alkaline nutrient solution by the plant roots.     

Liver and kidney toxicity in chronic use of opioids: An experimental long term treatment model

In this study, histopathological and biochemical changes due to chronic usage of morphine or tramadol in liver and kidney were assessed in rats. Thirty male Wistar rats (180–220 g) were included and divided into three groups. Normal saline (1 ml) was given intraperitoneally as placebo in the control group (n = 10). Morphine group (n = 10) received morphine intraperitoneally at a dose of 4, 8, 10 mg/kg/day in the first, second and the third ten days of the study, respectively. Tramadol group (n = 10), received the drug intraperitoneally at doses of 20, 40 and 80 mg/kg/day in the first, second and the third ten days of the study, respectively. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), creatinin, blood urea nitrogen (BUN) and malondialdehyde (MDA) levels were measured in the serum. Liver and kidney specimens were evaluated by light microscopy. Serum ALT, AST, LDH, BUN and creatinin levels were significantly higher in morphine group compared to the control group. Serum LDH, BUN and creatinin levels were significantly increased in the morphine group compared to the tramadol group. The mean MDA level was significantly higher in morphine group compared to the tramadol and control groups (P<0.05). Light microscopy revealed severe centrolobular congestion and focal necrosis in the liver of morphine and tramadol groups, but perivenular necrosis was present only in the morphine group. The main histopathologic finding was vacuolization in tubular cells in morphine and tramadol groups. Our findings pointed out the risk of increased lipid peroxidation, hepatic and renal damage due to long term use of opioids, especially morphine. Although opioids are reported to be effective in pain management, their toxic effects should be kept in mind during chronic usage Presented at the 10th XX Annual ESRA Congress, 6–9 April 2002, Warsaw, Poland.     

Iron promotes cadmium binding to citrate

Ironcadmium interactions are important in cadmium toxicity. Dietary iron supplements may decrease cadmium retention after oral cadmium exposure but the underlying mechanism is not known. Using a CdS/AgS ion selective electrode to measure [Cd²⁺] in physiological saline solution at pH 7.4, we show that Fe²⁺ promotes Cd²⁺ binding to citrate thereby decreasing the availability of free Cd²⁺. This suggests the formation of high molecular weight Cd²⁺Fe²⁺citrate complexes. We confirm this suggestion by showing that ¹⁰⁹Cd²⁺ is retained by 1 kDa cut off filters when present with total 50 M Fe²⁺ plus 1 mM citrate but not when present with citrate alone. The formation of high molecular weight complexes may prevent Cd²⁺ absorption. As citrate is part of the diet, we suggest that these ironcadmium interactions may contribute to the protective effect of iron against cadmium toxicity.