Protective effects of honey against cadmium-induced alteration of some biochemical parameters in rats

The objective of this study is to elucidate on the effect of honey on plasma and organ biochemical parameters of albino rats exposed to acute and sub-chronic dose of cadmium chloride. Uric acid levels, activities of plasma lactate dehydrogenase (LDH), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, organ (liver, lungs, and kidney) AST, ALT, superoxide dismutase (SOD), and catalase (CAT) were determined. Plasma uric acid and glucose levels, plasma LDH, AST, and ALT activities were significantly decreased; activities of organ SOD, CAT, AST, and ALT activities were increased in rats administered sub-chronically and acutely with cadmium (Cd). Treatment with honey restored their levels to normal.     

Enzymatic and cellular level effects of chromium∗

Exposure of Cr to four hepatic enzymes activities of tilapia, viz. acid‐ and alkaline phosphatases, catalase and glucose‐6‐phosphatase, was contrary to the results obtained for Cd and Ni. This is the only heavy metal investigated thus far that dramatically augmented glucose‐6‐phosphatase by approximately 83% at a concentration of 12 mg L^‐1 in vivo in lieu of the fact of an initial inhibition of approximately 45 % at a lower concentration of Cr; 6 mg L^‐1. In the case of acid phosphatase and catalase activities progressive increment was observed up to 50 and 217% respectively at a concentration of 12 mg L^‐1 Cr. On the other hand, in contrast to all the investigated enzymes interestingly alkaline phosphatase was inhibited continuously at all concentrations up to 46% at 12 mgL^‐1 Cr. In vitro experiments were contrary to the above mentioned results, whereby all hepatic enzymes were inhibited with major inhibition observed for acid phosphatase of approximately 60% from 5 mgL^‐1 Cr onwards in the system.

At cellular level, Cr exposure at a lethal dose of 12 mgL^‐1 demonstrated similar effects to that of Cd. In general, the glycogen and fat reserves were depleted while lysosomal activity is increased. As compared to the effects of Cd, the mitochondria did not indicate any prominent reflection in the formation of intramitochondrial bodies. Further, similar to Cd, the cell membrane as well as nucleus were not affected.     

Metalaxyl—its persistence and metabolism in soil

Different biotic and abiotic factors were found to play a vital role in attenuating metalaxyl residues in soil. In addition to metalaxyl many other products were found by HPLC and GC‐MS analysis while studying its soil metabolism in presence of natural sunlight. Three compounds were identified and characterized: 2,6‐dimethylaniline, 2,6‐dimethyl‐N‐ethylacetanilide and N‐(2,6‐dimethyl phenyl) alanine methyl ester.     

硝基芳香化合物的植物作用研究进展

硝基芳香化合物是环境中难以降解的污染物之一。因其用途广泛,大量残留于土壤,水体和大气中,造成的环境污染日趋严重。多种植物对该类污染物具有吸收、富集和代谢降解作用,利用植物对其环境污染进行治理是一种有效的方法。文章在总结国内外有关硝基芳香化合物的植物作用研究基础上,重点阐述了植物对硝基芳香化合物的吸收、转运和代谢过程,分析了吸收、代谢机理以及影响吸收的因素;硝基芳香化合物的理化特性、浓度和植物自身特性及其它外界条件都会影响植物对该类化合物的吸收,植物可以通过体内降解、体外联合代谢、根部释放酶催化的机制实现该类化合物的降解。目前,硝基芳香化合物进入植物细胞膜的机理认知不足,模拟模型缺乏有力数据验证;代谢机制中参与反应的酶、化合物等体系和反应产物环境特性仍不明确,植物修复可行性缺乏有力证据。未来将在模型预测构建、降解机理和修复工程的实际应用方面作进一步探究,以形成系统的认知,为硝基芳香化合物污染土壤和农产品的生态风险评价以及植物修复提供理论依据。     

Tertiary-butyl acetate metabolism,toxicity, and human health considerations

Tertiary-butyl acetate (TBAC) (CAS No. 540-88-5) is an organic solvent with a potential for occupational and environmental exposure as a result of its use in industrial coatings, adhesives, inks, and degreasers. The objective of these studies was to extend the toxicological database upon which health hazard and risk assessments of TBAC can be made. The metabolism of TBAC was studied in rats exposed by inhalation for 6?h to concentrations of 100 or 1000?ppm. There was an evidence of partial saturation of TBAC absorption and metabolism at some concentration below 1000?ppm. Approximately 5% of the low dose and 26% of the high dose was expired without change within 12?h, while the retained material was rapidly metabolised and excreted, mostly in the urine, within 24?h. Very little radioactivity remained in the tissues after day 7. The metabolism of TBAC appears to follow two major routes: hydroxylation of the tertiary-butyl moiety to form 2-hydroxymethylisopropyl acetate and ester hydrolysis to form tertiary-butyl alcohol (TBA). A minor route involves oxidation of the acetate moiety. Based on the proportion of metabolites that can clearly be assigned to one or the other major pathway, hydroxylation of the tertiary-butyl moiety prevails at 100?ppm, while hydrolysis of the ester bond predominates at 1000?ppm.

Based on nose-only inhalation exposure of rats to TBAC for 6?h, the LC50 for males and females combined is approximately 4200?ppm. Clinical signs included exaggerated breathing, staggering, tremors, and lethargy approximately 1?h after the exposure, but all surviving rats appeared normal from 24?h until the end of the 14?day observation period. An LC₅₀ was not identified for mice. After exposure of whole body for 6?h to 3000?ppm, the highest concentration tested, all mice were prostrate for most of the exposure time, but there were no deaths.

Groups of five male and five female Sprague-Dawley rats were exposed nose-only to 0, 100, 400, or 1600?ppm TBAC 6?h?day^?1 5 days?wk^?1 for 2?weeks. There were no effects on body weight, feed or water consumption, or necropsy findings. Male rats exposed to 1600?ppm had increased liver weights and hypertrophy of centrilobular hepatocytes. An increased proportion of cortical tubule cells with hyaline droplet accumulation was observed in all treated groups of males. Groups of five male and five female CD-1 mice were exposed whole body to 0, 190, 375, 750, or 1500?ppm TBAC 6?h?day^?1 for 14 consecutive days. There were no effects on body weight, feed consumption, or necropsy findings. Liver weights were increased in female mice at 750 and 1500?ppm. Minimal hypertrophy of centrilobular hepatocytes was found in female mice at 375, 750, and 1500?ppm and in male mice at 1500?ppm TBAC.

TBAC did not induce gene mutations in bacterial tests with strains of S. typhimurium and E. coli. Further, there was no evidence of clastogenic activity from tests either for the induction of chromosomal aberrations in human lymphocytes in vitro in the presence or absence of S9 mix or for the induction of micronuclei in bone marrow cells of rats exposed by inhalation for 6?h to 1600?ppm TBAC.

These results are relevant to human health risk assessment and are discussed in the context of previous studies. The weight of the scientific evidence supports the conclusion that TBAC has lower acute toxicity than previously suggested, that it is rapidly excreted when inhaled, and that neither TBAC nor its TBA metabolite are genotoxic or potential human carcinogens.     

Effects of alcohol–kola nut interactions on brain glucose oxidase,glutamine synthase,and adenylate deaminase activities in Wistar rats

The effects of alcohol–kola nut interactions on activites of whole brain glucose oxidase, glutamine synthetase, and adenylate deaminase were examined in Wistar rats. Thirty Wistar albino rats were divided into six groups. Control group (1) received a placebo (4 mL of distilled water). Groups 2–6 were treated for a 21-day period with either 10% (v/v) alcohol, kola nut, caffeine, alcohol + kola nut, or alcohol + caffeine at 50 mg per kg in a total volume of 4 mL vehicle via gastric intubation, respectively. One day after the final treatment, the whole brain was harvested and processed to examine for several biochemical parameters, including activities of glucose oxidase, adenylate deaminase, and glutamine synthetase. Results showed that alcohol–kola nut interaction decreased the activities of glucose oxidase, adenylate deaminase, and glutamine synthetase in whole brain, suggesting inhibition of glutamine synthesis, decreased energy (ATP) production, ionic transport and decreased neuronal processes. Data indicates that alcohol–kola nut or alcohol–caffeine interactions modify neuronal processes in rat brain; however, the clinical importance of this is not known.     

生物活性炭滤池的启动运行

对生物活性炭滤池启动运行中微生物生物量、生物活性、代谢功能及水质指标的变化情况进行连续分析.结果表明,生物活性炭滤池中异养微生物的平板计数生物量变化呈"S"形曲线,与微生物生长规律相符合,这反映滤池中微生物群落有明显的适应期、对数期和稳定期等生长阶段.脱氢酶活性随挂膜时间延长不断增加,第30天后达到稳定水平.滤池中微生物群落碳源代谢能力随挂膜时间的推进而增强,第40天时微生物群落的丰富度指数和Shannon多样性指数达到相对稳定值.氨氮(NH4+-N)与高锰酸盐指数(CODMn)去除率经过降低—缓慢上升—稳定的变化过程后,在第40天时去除率分别达到80%和28%左右.滤池启动运行29 d后溶解氧(DO)消耗率基本稳定,其值为18%.因此,在生物活性炭滤池挂膜过程中,分析微生物生长代谢与水质的变化特征可判断挂膜启动过程是否完成.图6表1参22     

草甘膦生产工艺水资源代谢分析与优化建议

以某农药集团草甘膦生产工艺为例,运用工业代谢分析方法对其水资源代谢过程进行量化分析,建立了水代谢平衡账户并绘制了水代谢图,在此基础上,识别和筛选出草甘膦生产过程中的主要用水单元及废水排放单元,并据此提出优化建议. 结果表明,草甘膦生产过程中的主要用水类别为蒸汽,其蒸汽消耗单元多且用汽量大,而换热网络单一,冷凝水浪费较严重,系统中水资源重复利用水平较差.针对该问题,从系统优化和节水管理等方面提出了工艺废水的重复利用及主要用汽单元之间的换热网络优化等建议,以期提高生产过程中的水资源利用效率.      

Ecological network and emergy analysis of urban metabolic systems: Model development,and a case study of four Chinese cities

Analysis of the structure and function of urban metabolic systems is an important goal of urban research. We used network pathways and network utility analysis to analyze the basic network structure of the urban metabolic system and the complex ecological relationships within the system, providing a new way to perform such research. Using four Chinese cities as examples, we developed an ecological network model of the urban metabolic system. By using network pathway analysis, we studied the changing relationships between metabolic length and the number of metabolic pathways, and between metabolic length and reachability. Based on the distribution of the number of metabolic pathways, we describe the basic structure and intercompartment relationships of the system. By using the sign distribution in the network utility matrix, we determined the ecological relationships and degree of mutualism between the compartments of the system. The basic components of the system consisted of the internal environment, the external environment, and the agricultural, industrial, and domestic sectors. With increasing metabolic length, the ecological relationships among the components of the system became more diverse, and the numbers of metabolic paths and their reachability improved. Although the basic network structure of the four cities was identical, the mutualism index differed. Beijing's mutualism index was superior to that of Shanghai, and much higher than those of Tianjin and Chongqing. By analyzing the structure and function of the urban metabolic system, we provide suggestions for optimizing the structure and adjusting the relationships, and propose methods for the application of ecological network analysis in future urban system research.     

铜污染草地对放牧乌蒙半细毛羊矿物质元素代谢的影响

为了评价草地铜污染对放牧乌蒙半细毛羊的影响,探讨铜污染的治理方法,在乌蒙山区的妈姑镇和凉水沟开展草地放牧试验和矿物质元素补充研究。应用原子发射光谱分析土壤、牧草和动物组织的重金属含量,应用全自动血液分析仪分析血液指标。放牧试验的结果显示:铜污染草地放牧明显增加了动物组织铜和锌的含量(P 0.01),降低了动物组织钼和铁的含量(P 0.01),试验结束时,试验组动物的血红蛋白(Hb)、红细胞压积(PCV)、红细胞数(RBC)和平均红细胞体积(MCV)显著低于对照组(P 0.01),羊毛产量和长度显著低于对照组(P 0.01)。矿物质元素补充试验的结果显示:补充硫酸钠明显降低了铜污染草地放牧动物血液和肝脏铜元素含量,补充试验结束时,处理Ⅰ组动物血液的Hb、PCV、RBC和MCV显著高于处理Ⅱ组(P 0.01),血液指标达到正常范围。处理Ⅱ组动物血液和肝脏铜元素的含量继续升高,动物组织钼的含量继续降低(P 0.01),Hb、PCV和RBC继续下降,试验结束时出现溶血性贫血,但补充硫对羊毛品质的相关指标没有显著的影响。研究表明,铜污染草地严重影响了乌蒙半细毛羊的矿物质代谢,补充硫酸钠可以部分拮抗铜的毒性。