短棒状杆菌外用制剂安全性的评价

研究短棒状杆菌外用剂型,为体外用药开辟新途径。将短棒状杆菌接种在适宜培养基上,连续扩增传代,培养终液稀释成不同浓度。依照新药管理办法,在动物体内进行各种安全性试验。结果显示:经急性毒性试验、长期毒性试验、生殖毒性试验,皮肤光敏试验、局部刺激试验等测定,在动物体内未见到毒性反应。该试验为短棒状杆菌外用制剂的开发提供了安全性依据。     

人参花食用安全性研究

目的:对人参花食用安全性进行毒理学评价.方法:采用大鼠经口急性毒性试验、遗传毒性试验(Ames试验、小鼠骨髓细胞微核试验、小鼠精子畸形试验)、大鼠30 d喂养试验.结果:雌、雄大鼠经口最大耐受剂量(MTD)均大于17.4 g/kg·bw.3项遗传毒性试验结果均为阴性.在大鼠30 d喂养试验中,6.0 g/kg·bw,3.0 g/kg·bw及1.5g/kg· bw 3个剂量组的实验动物均生长发育良好,体重、摄食量、饮水量、血液学、血液生化学、脏器系数及病理组织学相关指标均未见异常变化.结论:人参花属于实际无毒物,未见遗传毒性,长期服用是安全的.     

氨对草鱼的急性和亚急性毒性

试验测定了氯化铵对草鱼的急性和亚急性毒性。急性试验采用26,47,60和125日龄的草鱼,亚急性试验用60日龄草鱼种,经0.970,0.455,0.099,0.054和0.012(对照)毫克NH_3/升(未离解氨,un-ionized ammonia)暴露45天。26,47,125日龄草鱼的96小时LC_(50)(半数致死浓度)分别是0.570,1.609和1.683毫克NH_3/升,而47,60,125日龄的48小时LC_(50)则分别为1.727,2.050和2.141毫克NH_3/升。急性毒性试验结果表明,26日龄草鱼最为敏感。在亚急性毒性试验中,根据氨对草鱼生长和鳃组织的影响,求得未离解氨的最大允许毒物浓度为0.054—0.099毫克NH_3/升。     

模拟池塘微生态系统研究尾矿砂中重金属吸附及其生物有效性

利用模拟池塘微生态系统开展长期暴露毒性实验,研究了铜矿尾矿砂中重金属在各个环境介质中的迁移及其生物有效性,实验结果较好地反映尾矿库湿地系统中重金属的生物毒性作用与生物可利用性,结果表明的重金属浓度会刺激生物生长与繁殖,而过高的重金属浓度则对生物的生长繁殖具有明显的毒性作用。微生态系统各组份间的重金属含量与尾矿砂中重金属含量具有良好的相关性,生物体内重金属累积与底泥尾矿砂中重金属浓度,种类和生物类属有关,试验研究为矿山生态修复过程的湿地利用提供重要的科学依据。     

低分子质量魔芋甘露寡糖的长期毒性与遗传毒性研究（英文）

魔芋甘露寡糖是一种具有肠道菌群调节作用的新型食品添加剂.本研究首次通过酶解与有机溶剂沉淀法制备了低分子质量的甘露寡糖(聚合度2~7),并对这类寡糖进行了长期毒性与遗传毒性评价.在长期毒性试验中,以大鼠为实验对象,分低、中、高(2.25,5.25,7.50 g/kg)药物剂量组和阴性对照组,连续灌胃给药90天.一般状况观察、生化指标、血液学指标、病理学等与对照组比较均无显著性差异,而大体解剖观察发现,部分大鼠的肝脏与肾脏形态发生变化,但这些变化均在正常范围内,且其他各项指标差异均无统计学意义.此外,一系列实验包括小鼠骨髓微核实验、Ames试验、小鼠精子畸变试验均未发现低分子质量甘露寡糖有明显的遗传毒性.试验结果提示,本研究方法获得的低分子质量甘露寡糖在本实验条件下未发现长期毒性与遗传毒性.     

E605防治吹绵介壳虫之初步报告

Boyce氏首先试用了E605在防治介壳虫之试验中,而获得良好之结果,渠所试验之对象为不同种类之介壳虫十余种,其中包括有吹绵介壳虫,其所用之药为25％之可湿性粉,加水稀释至.03至.05％之浓度(本试验中所用浓度即以此为根据)。对於各种不同之介壳虫,在各种不同之地区、气候及季节所用量大有出入。根据某些学者     

利用正交方法进行藻类细胞生长抑制试验制定稳定塘入水标准的研究

藻类细胞生长抑制试验在单项毒物条件下进行时,常未考虑毒物对藻类细胞的联合作用（拮抗效应、叠加效应和协同效应）。本研究采用单项毒物试验和多种毒物同时存在时的正交试验（Ｌ１６＜４￣５＞）,评价了进入武汉市墨水湖中试稳定塘的主要污染物（硫化物、挥发酚、石油类）对羊角月牙藻的９６ｈ的毒性效应。结果表明,正交试验的ＥＣ５０值都比单项毒物试验低得多,其９６ｈＥＣ５０降低２０－８０％,受试的几种主要污染物对藻类有协同毒性效应或叠加毒性效应。采用正交试验方法进行藻类细胞生长抑制试验以制定稳定塘的入水标准,更接近真实。     

环境毒物对金黄色葡萄球菌毒性影响的研究

采用毒物在营养琼脂中垂直扩散方法,通过测定毒物在营养球脂中抑制金黄色葡萄球菌生长产生蓝色抑菌带的长度,研究Hg、Cr^6 、Pb、CN^—、As、NO2^—、F^—及苯酚对金黄色葡萄球菌的毒性影响。结果表明：受试毒物的浓度与抑菌带有相关性,相关系数具显著意义;对毒物的敏感性为Cr^6 ＞Hg＞As＞CN^—＞Pb＞NO2^—＞苯酚＞F—;多种毒物共同作用其毒性影响增加。     

以毒性鉴别评价法评价化工废水处理效果的研究

江苏省某化工厂废水处理设施进、出水经大型Sou（Daphnia magna）急性毒性试验的结果表明,废水在处理前、后均显示毒性。采用毒性鉴别评价的试验程序,对处理设施的进、出水进行了关键毒物的鉴别和评价。发现进水中存在的关键毒物为金属铜离子并共存多种金属和极性有机毒物,而出水中存在的毒物为酸性条件下易被氧化的有毒有机物。该废水处理工艺对废水毒性去除率为77.6%。由此可见,该处理工艺对金属离子有较好的去除,而对有毒有机化合物的去除效果不甚理想,因此,该厂生产工艺和废水处理工艺还有待进一步改进。     

A/DAT-IAT工艺处理城市污水的生态安全调控

以A/DAT-IAT工艺出水的常规指标和生态毒性指标为考察对象,对A/DAT-IAT工艺处理城市污水的运行周期（T）、外回流比（R₁）、内回流比（R₂）和混合液污泥浓度（MLSS）4个控制参数进行了3个水平的正交试验.结果表明：混合液污泥浓度（MLSS）是4个控制参数中对考察对象影响最大的因素;去除常规指标的最优运行条件为运行周期3 h,外回流比20%,内回流比150%,MLSS 5000 mg·L^-1;去除生态毒性指标的最优运行条件为运行周期3 h,外回流比20%,内回流比150%,MLSS 3000 mg·L^-1.分析表明,造成去除两类指标的最优运行条件不同的主要原因可能是污水中存在具有一定生态毒性的难生物降解有机物和经水解酸化后毒性增强的有机物.本试验研究为该工艺今后的生态安全调控改进提供了参考方向.建议投加絮凝剂,同时适当选择运行控制参数,以共同提高对常规指标和生态毒性指标的去除效果.     

A simple diluter for flow-through toxicity studies

An original, simple, and inexpensive diluter for flow-through toxicity studies is described. The diluter is run only by water gravity and has no moving parts. The main units of the device are made of very cheap disposable components and may be mounted without qualified technical assistance. It has neither metal nor any other kind of chemically active parts contacting experimental media. The diluter may be easily modified to study toxicants independently or in mixtures, in fact, as many toxicants as are necessary. When properly calibrated, it does not require further adjustments even during long-term experiments. The main original feature of the diluter described here is its dosing system, which is based on a vacuum air lock. This key system is very simple, reliable, includes neither mechanical nor electrical devices, and ensures adequate accuracy in dosing.     

用于水污染生物检测的恒流稀释装置的调节及计算方法

本文根据恒流稀释装置的工作原理,对其运行中的各种因素及其相互关系进行了理论分析。提出了关于稀释因数、系列浓度、各种流量和试液更新时间的计算方法,推荐了合理化的调节操作程序。       

Measurement of chronic toxicity using the opossum shrimpMysidopsis bahia

The chronic toxicity of silver and endosulfan to the opossum shrimpMysidopsis bahia was determined using continuous-flow bioassays. The 28-day bioassays measured survival, fecundity, and growth (length and weight measurements). Maximum acceptable toxicant concentrations (MATC) were estimated from measured toxicant concentrations. MATC values were similar using either brood size or growth as a criterion for sublethal effects. As an alternative to the determination of fecundity impairment, measurement of growth reduction in response to exposure to toxicants may provide a useful tool in the assessment of chronic toxicity inMysidopsis life-cycle bioassays.     

Continuous-flow ATP amplification system for increasing the sensitivity of quantitative bioluminescence assay

We constructed a novel ATP amplification reactor using a continuous-flow system, and this allowed us to increase the sensitivity of a quantitative bioluminescence assay by controlling the number of ATP amplification cycles. We previously developed a bioluminescence assay coupled with ATP amplification using a batch system. However, it was difficult to control the number of amplification cycles. In this study, ATP amplification was performed using a continuous-flow system, and significant linear correlations between amplified luminescence and initial ATP concentration were observed. When performing four cycles of continuous-flow ATP amplification, the gradient of amplification was 1.87^N. Whereas the lower quantifiable level was 500 pM without amplification, values as low as 50 pM ATP could be measured after amplification. The sensitivity thus increased 10-fold, with further improvements expected with additional amplification cycles. The continuous-flow system thus effectively increased the sensitivity of the quantitative bioluminescence assay.     

Bait distribution among multiple colonies of Pharaoh ants (hymenoptera: Formicidae)

Pharaoh ant, Monomorium pharaonis (L.), infestations often consist of several colonies located at different nest sites. To achieve control, it is desirable to suppress or eliminate the populations of a majority of these colonies. We compared the trophallactic distribution and efficacy of two ant baits, with different modes of action, among groups of four colonies of Pharaoh ants. Baits contained either the metabolic-inhibiting active ingredient hydramethylnon or the insect growth regulator (IGR) pyriproxyfen. Within 3 wk, the hydramethylnon bait reduced worker and brood populations by at least 80%, and queen reductions ranged between 73 and 100%, when nests were in proximity (within 132 cm) to the bait source. However, these nest sites were reoccupied by ants from other colonies located further from the bait source. The pyriproxyfen bait was distributed more thoroughly to all nest locations with worker populations gradually declining by 73% at all nest sites after 8 wk. Average queen reductions ranged from 31 to 49% for all nest sites throughout the study. Even though some queens survived, brood reductions were rapid in the pyriproxyfen treatment, with reductions of 95% at all locations by week 3. Unlike the metabolic inhibitor, the IGR did not kill adult worker ants quickly, thus, more surviving worker ants were available to distribute the bait to all colonies located at different nest sites. Thus, from a single bait source, the slow-acting bait toxicant provided gradual, but long-term control, whereas the fast-acting bait toxicant provided rapid, localized control for a shorter duration.     

Novel,linked bioreactor system for continuous production of biologics

A novel, alternative intensified cell culture process comprised of a linked bioreactor system is presented. An N-1 perfusion bioreactor maintained cells in a highly proliferative state and provided a continuous inoculum source to a second bioreactor operating as a continuous-flow stirred-tank reactor (CSTR). An initial study evaluated multiple system steady-states by varying N-1 steady-state viable cell densities, N-1 to CSTR working volume ratios, and CSTR dilution rates. After identifying near optimum system steady-state parameters yielding a relatively high volumetric productivity while efficiently consuming media, a subsequent lab-scale experiment demonstrated the startup and long-term operation of the envisioned manufacturing process for 83 days. Additionally, to compensate for the cell-specific productivity loss over time due to cell line instability, the N-1 culture was also replaced with younger generation cells, without disturbing the steady-state of the system. Using the model cell line, the system demonstrated a two-fold volumetric productivity increase over the commercial-ready, optimized fed-batch process.     

Automated Complement Fixation with Low Reagent Consumption

A microvolume automated (continuous-flow) system for the detection of complement-fixing antigen or antibody was evaluated. The model complement fixation test used was the detection of deoxyribonucleic acid antibody, and comparisons were made with a manual procedure. An "automatic two-dilution" feature of the apparatus was not used because of the clinical need for antibody titers. The system proved useful for the detection and estimation of anti-deoxyribonucleic acid antibody in patients with systemic lupus erythematosus and, indeed, accomplished this with low reagent consumption, a useful feature not available in "older" continuous-flow complement fixation systems.     

Liquid level control in an aerated continous-flow fermentor

An electronic liquid level control system was developed to maintain constant working volume in a continuously fed and aerated fermentor from which spent medium was continously withdrawn by microfiltration in an external recycle loop. The level control system was comprised of an admittance sensor in the fermentor and an external transmitter and controller, which together regulated the speed of a recycle pump and thus the rate of liquid withdrawal from the fermentor. During test bacterial culture the liquid level was maintained usually within +/- 1% and always within +/- 5%. The control system could be applied to various other types and scales of continuous-flow fermentors.     

Fraser river sediments and waters evaluated by the battery of screening tests technique

The suitability of a variety of microbiological, biochemical and toxicant screening tests to become part of a battery of test procedures to identify degraded or degrading water bodies are evaluated in this report. Data were collected from 40 sampling sites within the Fraser River Basin in British Columbia. These data re-emphasize that individual toxicant, biochemical or microbiological screening tests do not provide a sufficient data base upon which realistic management decisions can be made. This study also confirms that the fecal sterol tests do not seem amenable to a'battery of tests' approach and that the Daphnia magna test continues to be the most sensitive procedure for indicating the presence of contaminants with toxicant activity.     

Influence of fluctuating salinity on insecticide tolerance of two euryhaline arthropods

Among many other abiotic variations in an estuarine ecosystem, osmotic stress is an inescapable part of life. Organisms living in such environments must cope with changing osmotic conditions by either behavioral or physiological adaptations. Pollutants may increase the physiological stresses that an osmoregulating animal may encounter. We have developed a flow-through system that exposes test species to insecticides and continuously changing salinity conditions. This system has provided an insight into how susceptibility of a species to an insecticide can be affected by changing concentrations of salinity. Toxicity tests using this system were conducted with two arthropod species that are found in saline habitats: mosquito Aedes taeniorhynchus (Wiedemann) and brine shrimp (Artemia sp.). Four insecticides-aldicarb, dimethoate, imidacloprid, and tebufenozide-were studied. Both species were exposed for 48 h to a concentration of various insecticides that would cause 50% of the population to die in hyperosmotic artificial sea water (ASW). The mortality rate for both species was more acute in increasing salinity (10-200% ASW) than in decreasing salinity (200-10% ASW) conditions. A. taeniorhynchus was more susceptible than Artemia when exposed to its hyperosmotic LC50 concentration of toxicant while experiencing a change in salinity, e.g., adjusting to a changing salinity decreased the LT50. Our results indicated a change in salinity; more importantly, the direction of change altered the susceptibility of these organisms.