Ecotoxicity testing of heavy metals using methods of sediment microbiology

Current measures of microbe-mediated biogeochemical processes in sediments were examined for their potential use as indicators of heavy metal ecotoxicity in both river sediments and bacterial cultures. Assays were carried out with HgCl₂, CuSO₄, and 3CdSO₄ · 8H₂O added to sediment samples and bacterial cell suspensions at concentrations ranging from 0.1 to 10 mM and 0.1 μM to 1 mM, respectively. Chemoautotrophic CO₂ fixation by Elbe River sediment microbiota was most sensitive to Hg²⁺ and Cd²⁺, but not to Cu²⁺. Among the estimates of heterotrophic productivity, incorporation of leucine into cellular protein showed clearer dose responses than incorporation of thymidine into bacterial DNA. Thymidine incorporation was highly resistant to and even stimulated by metal ions, particularly in starved and anaerobic cultures of a test strain of Vibrio anguillarum. Similar metal ion induced “overshoot” responses beyond the levels of untreated controls were noted for mineralization of ¹⁴C-glucose by V. anguillarum and, in the case of Cd²⁺, also in sediment. As a less complex measure of microbial respiratory activity, succinate dehydrogenase (SDH) showed normal dose responses without stimulatory effects, as long as bacterial cell homogenates were assayed. Despite this result, it is concluded that levels of SDH in natural sediment microbiota are inevitably affected by metal-induced processes of selection and enzyme synthesis, and would thus fail to provide an appropriate measure of metal ecotoxicity. The final conclusion is that current parameters of microbial production and activity often reveal dose responses that do not fulfill basic requirements of ecotoxicity testing in metal-polluted sediments. © 1993 John Wiley & Sons, Inc.     

Subchronic oral toxicity testing in rats with a liquid hand-dishwashing detergent containing anionic surfactants

A subchronic oral toxicity study on a model liquid dishwashing detergent containing anionic surfactants was performed to verify that the formulation, made up of a mixture of various ingredients, did not possess any toxicological properties that would not have been expected from available data for each separate ingredient. The product was administered to rats for 13 wk at dietary levels of 0, 0.025, 0.25 or 2.5% (w/w) in the diet. No adverse effects on gross or microscopic histopathology were apparent at any dose level, although increased relative liver weights at the 2.5% level suggested that this dose caused some adaptive changes.     

Bioavailability evaluation of a controlled-release dextromethorphan liquid

A randomized, two-way, steady-state crossover study was performed in 24 healthy male volunteers to evaluate the bioavailability of a controlled-release (CR) dextromethorphan (DM) suspension. Only slow and intermediate DM metabolizers were allowed to participate in the study; determination of metabolizer status was performed before study enrollment. Each volunteer was administered 30 mg of an immediate-release (IR) DM solution qid or 60 mg DM as a CR suspension bid for two weeks, for a total daily dose of 120 mg. After a two-week washout period, the subjects were administered the alternate treatment. Blood samples were collected over a 12-hour dosing period on the last day of each treatment and analyzed for DM and its active metabolite, dextrorphan (DP). In addition, urine was collected over the 12-hour steady-state dosing interval and measured for DM and two metabolites. Pharmacokinetic determinations were made from plasma DM and DP data, and total urinary excretion was determined. All comparisons made between the two formulations indicated that the CR DM suspension was bioequivalent to the IR DM solution at steady state, while producing a prolonged release of the drug over time.     

Ecotoxicity studies of the levulinate ester series

The increasing interest in the development of novel green solvents has led to the synthesis of benign alternative products with minimized environmental impacts. However, most of published studies on green solvents focus primarily on their physicochemical properties, with limited emphasis on absence of ecotoxicological assessment. In this study, we evaluated the acute ecotoxicity of four levulinates (levulinic acid, methyl levulinate, ethyl levulinate and butyl levulinate) on freshwater algae (Chlamydomonas reinhardtii), bacteria (Vibrio fischeri), daphnids (Daphnia magna) and earthworms (Eisenia foetida) using various dose–response tests. As a general trend, the toxicity of levulinate esters in aquatic exposure (assessed as the EC₅₀) increased as a function of increasing alkyl chain length; accordingly, the most toxic compound for the aquatic organisms was butyl levulinate, followed by ethyl levulinate and methyl levulinate. The most toxic compound for E. foetida (terrestrial exposure) was methyl levulinate, followed by ethyl levulinate, butyl levulinate and levulinic acid; in this case, we observed an inverse relationship between toxicity and alkyl chain length. Based on both the lowest EC₅₀ found in the aquatic media and the ratio between predicted environmental concentration and the predicted no-effect concentration, we have estimated the maximum allowable values in the environment for these chemicals to be 1.093 mg L^?1 for levulinic acid, 2.761 mg L^?1 for methyl levulinate, 0.982 mg L^?1 for ethyl levulinate and 0.151 mg L^?1 for butyl levulinate.     

Assay and purity evaluation of sunepitron hydrochloride by reversed-phase liquid chromatography using a reference standard composite

A reference standard composite was prepared that contained the active pharmaceutical ingredient sunepitron and three potential impurities. This standard was characterized and used for concomitant quantitation of sunepitron and its potential impurities in samples of drug substance and drug product. This approach minimizes the number and quantity of reference standards which often are expensive to synthesize, characterize, and maintain. In addition, running assays becomes simpler because the number of reference standard solutions required for each assay is reduced. Reference standard composites can also be used for qualitative applications such as demonstrating system suitability or for retention times markers for process related impurities or degradants.     

Prediction of eye irritation potential of liquid and granular laundry detergent formulas using the bovine corneal opacity and permeability (BCOP) assay

Abstract

Evaluation of eye irritation potential is a routine part of consumer product testing. Increasingly, companies are using in vitro methods to perform these assessments. We have used the bovine corneal opacity and permeability (BCOP) assay for the prediction of eye irritation of liquid and granular laundry detergent formulas. The BCOP assay was selected because it can distinguish between moderate and severe irritants as required to evaluate these classes of formulations. Corneas were maintained in short-term culture and the exposure conditions were optimized using marketed product upper-end benchmark formulas for each product class. The primary endpoint was the loss of epithelium as measured by the change in permeability of the cornea to fluorescein and was complemented by histological evaluation of depth of injury. The opacity endpoint was not used, as the surfactants in these products do not induce opacity in proportion to the depth of injury induced. Liquid laundry detergents were diluted to 25% and exposed to the corneas for 20?min while the granular detergents were diluted to 10% and exposed for 30?min. These conditions were selected for each product type to induce OD₄₉₀ values in the midrange (between 0.5 and 0.6 absorbance units) and so increased or decreased irritation potential in the test formulas could readily be observed. Seventeen liquid and eleven granular laundry detergents were tested and the OD₄₉₀ values ranged from 0.278 to 2.193 for the liquid detergents and 0.267 to 0.856 for the granular detergents. Histological changes in the epithelium and stroma were consistent with the OD₄₉₀ values. These data suggest that the OD₄₉₀ provides an effective measure of epithelial cell loss (degree of cell lysis) and thus irritation potential for these surfactant-based formulas. The upper-end benchmark set a known upper range for acceptable irritation for the product class. Those formulas inducing lower OD₄₉₀ values may be considered to fall within the acceptable range while those inducing greater OD₄₉₀ values should receive further evaluation and perhaps reformulation.     

The effect of detergent concentration on monomer activity in a non-ionic detergent solution

The mono-octyl ether of hexaoxyethylene glycol has been synthesized and carefully purified using foam fractionation in the ultimate stages of the purification. Surface tension measurements of solutions of the detergent in water using a Wilhelmy plate indicate a continuing decrease in surface tension with increasing detergent concentration above the critical micellar concentration. Vapour pressure osmometry using the Mechrolab 302 substantiated the interpretation of the results in terms of the law of mass action.     

A novel method to determine residual detergent in biological samples post endotoxin reduction treatment and evaluation of strategies for subsequent detergent removal

Endotoxin removal using detergent washes and extractions are well-established, efficient, and cost-effective methods; however, removing residual detergent post treatment has been shown to be a challenge. In this communication, we show a simple and fast method for determining the detergent concentration in a protein solution post treatment and highlight strategies for detergent removal to achieve levels below the critical micelle concentration (CMC), the minimum concentration at which detergent micelles form.     

Comparative assessment of the acute skin irritation potential of detergent formulations using a novel human 4-h patch test method

Predictive skin irritation test methods, which do not require use of animals, are needed for the pre-market assessment of detergent formulations. The utility of a novel and ethical human acute skin irritation patch test method, originally developed for chemical skin irritation assessment, was evaluated. In this IRB-approved method, subjects were patched under occlusion for increasing periods of time up to 4 h in duration. The total incidence of positive skin reactions for test products was compared to a positive control (20% aqueous sodium dodecyl sulfate [SDS]). Acutely irritating formulas were defined as those showing a significantly increased or equal incidence of positive responders compared with that of SDS. The time of exposure required for 50% of subjects to show a positive skin reaction (TR₅₀ value) was calculated for each product and enabled test product comparisons within and between studies. Using this approach, 24 detergent formulations of various types were tested in seven individual studies. The skin irritation profiles were generally consistent within product types, which could be categorized as follows (by decreasing irritancy): mold/mildew removers (average TR₅₀ = 0.37 h) > disinfectants/sanitizers (0.64 h) > fabric softener concentrate (1.09 h) = aluminum wash (1.20 h) > 20% SDS (1.81 h) > liquid laundry detergents (3.48 h) > liquid dish detergents (4.16 h) = liquid fabric softeners (4.56 h) = liquid hand soaps (4.58 h) = shampoos (5.40 h) = hard surface cleaners (6.34 h) > powder automatic dish detergents (>16 h) = powder laundry detergents (>16 h). In addition to formulation effects, some seasonal effects were noted; particularly greater winter-time reactivity to 20% SDS and the hard surface cleaner and liquid laundry formulations. These results demonstrate the utility of this patch test method for the comparative skin irritation assessment of these different product types.     

Ecotoxicity and fate of a silver nanomaterial in an outdoor lysimeter study

Sewage sludge is repeatedly applied as fertilizer on farmland due to its high nutrient content. This may lead to a significant increase of silver nanomaterials (AgNM) in soil over years. Therefore, our aim was to investigate the ecotoxicity and fate of AgNM under environmentally relevant conditions in outdoor lysimeters over 25 months. Two AgNM concentrations (1.7 and 8.0?mg/kg dry matter soil) were applied via sewage sludge into soil. In subsamples of the soil, incubated under laboratory conditions for 180 days, the comparability of outdoor and laboratory results regarding ecotoxicity was determined. The results from our long term lysimeter experiments show no detectable horizontal displacement in combination with very low remobilization to the percolate water. Thus, indicate that the sludge applied AgNM remains nearly immobile in the pathway between soils and leachate. However, Ag uptake to the roots of wheat and canola suggests that the chemical conditions in the rhizosphere induce AgNM remobilization from the incorporated sewage sludge even after two harvesting cycles. At the higher AgNM concentration a steady inhibition of the soil microflora was observed over 25 month in the lysimeter study, while there was no effect at the lower AgNM concentration. The results of the laboratory experiment reflect the findings of the lysimeter study and indicate that a risk assessment for AgNM based on data from laboratory tests is acceptable.     

43313例兰索拉唑用药患者的安全性自动监测研究

目的通过大样本自动监测研究,了解兰索拉唑真实世界中不良反应的发生情况。方法借助医疗机构ADE主动监测与智能评估警示系统调取2016年1月-2017年12月间解放军总医院43 313例使用过注射用兰索拉唑(规格:30 mg)的所有住院患者相关信息,回顾性研究兰索拉唑相关的不良反应。结果兰索拉唑致血小板减少、白细胞减少、中性粒细胞减少、贫血(血红蛋白减少)、肝损害、急性肾损伤和皮肤损害的发生率分别为0.10%(n=32 986)、0.14%(n=31 727)、0.11%(n=31 727)、0.11%(n=26 840)、1.00%(n=27 040)、0.02%(n=35 152)、0.07%(n=40 577);合计总发生率为0.96%;用药时长≥6 d为兰索拉唑肝损害的危险因素。结论兰索拉唑安全性较高,但临床仍需警惕其用药风险,用药时长超过5 d时需关注患者肝功能指标变化。     

Ecotoxicity assessment of the aquatic environment around Lake Kojima,Japan

To reduce the impact of chemical substances on the aquatic ecosystem, it is essential to understand their ecotoxicological properties in the natural aquatic environment. Consequently, we conducted an ecotoxicological study on the aquatic environment around Lake Kojima, a man-made lake located in the southwest of Japan. Lake Kojima receives its chemical inputs mainly from two rivers that flow through various agricultural and industrial areas. For ecotoxicity screening, surface water and sediment samples were collected 4 times in 1993 from 16 preselected sites. Then, the solutes in the filtered surface water were concentrated by ODS resin, and the organic chemicals in the suspended solids (SS) and sediments were extracted by acetone. A battery of five ecotoxicity tests (agar plate test using bacteria and yeast, algal growth inhibition test, Daphnia magna immobilization test, and root elongation test using lettuce seeds) was used to assess these extracts. The results show that the surface water extracts had a lethal effect on D. magna, the SS extracts suppressed algal growth, and the sediment extracts were inhibitory to the growth of yeast. A significant inhibitory effect by the sediment extracts from 4 lake sites and 3 river sites was detected by these ecotoxicity tests. Attempts also were made to identify the putative ecotoxic chemicals in the collected samples. Elementary sulfur was identified as one of the major toxicants in the sediment extracts that were inhibitory to the yeast growth. Moreover, samples of surface water around Lake Kojima, collected weekly from June to September in 1994, were found to contain three pesticides and were toxic to D. magna. But the concentration of the pesticides detected was too low to cause daphnia immobilization. It is believed that the toxicity of the water extracts was mainly due to the combined toxic effect of natural and man-made components. © 1996 by John Wiley & Sons, Inc.     

Chronic toxicity of a laundry detergent to the freshwater flagellate Euglena gracilis

Chronic toxicity of the common laundry detergent Ariel on the freshwater alga Euglena gracilis was investigated by growing the alga in a medium containing the detergent for 7?days. Cell density, motility, swimming velocity, gravitactic orientation, cell shape, photosynthesis and concentration of light-harvesting pigments were used as end point parameters for the assessment of toxicity. Cell density was significantly reduced at a concentration of 1?mg?l(-1) or above. Among the other tested parameters, with the exception of cell shape, gravitaxis and chlorophyll b, all were adversely affected by the detergent at concentrations exceeding 1?mg?l(-1). It is concluded that long-term (7-days) exposure to the detergent caused significant toxicity to E. gracilis. Furthermore, long-term tests with E. gracilis can be used as sensitive indicator for the toxicity assessment of laundry detergents in aquatic environments.     

Sysmex CA-7000血凝仪的应用效果评价

目的了解Sysmex CA-7000全自动血凝仪(CA-7000仪)测定凝血机制的性能。方法按照国际血液学标准化委员会制定的评价内容,对CA-7000仪测定凝血酶原时间(PT)、部分活化凝血活酶时间(APTT)、凝血酶时间(TT)和纤维蛋白原(Fbg)凝血四项的精密度、准确性、线性和携带污染率等进行实验评价。结果CA-7000仪测定PT、APTT、TT、Fbg的批内批间变异系数(CV)0.7%～2.3%,测定校正血浆误差绝对值为0.4%～4.0%,与Sysmex CA500全自动血凝仪(CA500仪)对比检测结果无统计学差异(P>0.05),线性相关分析r为-0.772～0.999,携带污染率为0～1.5%。结论CA-7000仪检测凝血四项的精密度好、准确度高、线性及交叉污染率达到实验室要求,适合于临床止凝血功能检测分析。     

动物活体自动采样技术的应用和评价

介绍在动物实验中一种先进的生物样品自动采集与处理系统,该系统结合液相色谱/质谱/质谱(LC/MS/MS)分析方法,可以为临床前药动学研究、药效学研究和安全性评价提供可靠的实验数据。利用该系统能够在清醒的、自由活动的实验大鼠、小鼠等啮齿类动物及灵长类动物完成生物样品的定时自动采集,并进行即时处理。不但节约人力,且大大提高了对少量低浓度生物样品的实验数据准确性;与此同时,还能实时监测实验动物的其他生理参数,从而可减少所用动物数量,改善动物的舒适性。若能把自动生物样品采集技术和现代先进的LC/MS/MS分析方法合并使用,则可显著提高临床前研究的速度和质量,以满足高通量药物筛选的要求。自动采样系统被我们用于大鼠口服卡马西平的药动学实验,结果证实它确实是临床前药动学、药效学研究及安全性评价的有效工具。