城市污泥中苯并[a]芘的超声提取、净化和检测

采用高效液相色谱法对城市污泥中的苯并[a]芘进行了分析.对其超声波提取、净化、洗脱方法进行了优化试验,确定优化条件为：以25 mL二氯甲烷/丙酮（1：1）作为混合提取溶剂,超声提取60 min后以弗罗里硅土柱对提取液进行净化处理,再用25 mL正戊烷淋洗、30 mL二氯甲烷/丙酮（4：1）洗脱.测试结果表明,该方法具有较高的测定精密度和准确度.     

苯并[a]芘诱导肺癌的分子机制研究进展

肺癌发病率及死亡率均较高,其对患者经济及社会医疗成本造成沉重的负担。大量研究证实环境致癌物苯并[a]芘{benz(a)pyrene,B[a]P}在肺癌发生发展中发挥关键作用,目前对其诱导肺癌的分子机制已尚有研究,但具体机制尚不清楚。本文将从B[a]P诱导肺癌生物学功能方面如细胞凋亡、细胞周期及增殖、细胞迁移及侵袭、炎症微环境以及表观遗传学方面进行综述,为环境致癌物诱导肺癌的预防及治疗提供依据。     

阴-阳离子有机凹凸棒石吸附水中苯并[a]芘的实验研究

初步研究了用聚二甲基二烯丙基氯化铵（PDMDAAG）和十二烷基硫酸钠（SDS）改性凹凸棒石对模拟微污染水中痕量苯并[a]芘的吸附作用。结果表明：在改性凹凸棒石投加量为15g／L、粒径为150μm、20℃、吸附时间60min条件下，污水中苯并[a]芘去除率可达98．56％。改性凹凸棒石对苯并[a]芘的吸附等温线呈中凹型，表明吸附过程存在溶剂化效应和分配效应协同作用。     

DNA damage by benzo[a]pyrene in the liver of mosquito fish Gambusia affinis

Exposure of Gambusia affinis to water containing different concentrations of benzo[a]pyrene (BaP) causes an increase in benzo[a]pyrene monooxygenase (BPMO) activity which reaches a maximum on the second day. Concomitantly, the DNA is altered in such a way that nuclease S1-sensitive sites (SSS) become measurable. The size distribution of liver DNA treated with nuclease S1 in control fish shows two populations of DNA by length, with means of 30 X 10(6) and 60 X 10(6) Daltons, respectively. In fish treated with 100 ppb BaP, the population with longer molecules of DNA disappears and shorter molecules increase in number. This may be explained in terms of the introduction of an additional 0.31-0.46 DNA nicks per control DNA molecule caused by metabolically activated BaP derivatives.     

Accelerated biodegradation of pyrene and benzo[a]pyrene in the Phragmites australis rhizosphere by bacteria-root exudate interactions

We investigated the biodegradation of pyrene and benzo[a]pyrene in Phragmites australis rhizosphere sediment. We collected P. australis plants, rhizosphere sediments, and unvegetated sediments from natural aquatic sites and conducted degradation experiments using sediments spiked with pyrene or benzo[a]pyrene. Accelerated removal of pyrene and benzo[a]pyrene was observed in P. australis rhizosphere sediments with plants, whereas both compounds persisted in unvegetated sediments without plants and in autoclaved rhizosphere sediments with sterilized plants, suggesting that the accelerated removal resulted largely from biodegradation by rhizosphere bacteria. Initial densities of pyrene-utilizing bacteria were substantially higher in the rhizosphere than in unvegetated sediments, but benzo[a]pyrene-utilizing bacteria were not detected in rhizosphere sediments. Mycobacterium gilvum strains isolated from rhizosphere sediments utilized pyrene aerobically as a sole carbon source and were able to degrade benzo[a]pyrene when induced with pyrene. Phragmites australis root exudates containing phenolic compounds supported growth as a carbon source for the one Mycobacterium strain tested, and induced benzo[a]pyrene-degrading activity of the strain. The stimulatory effect on benzo[a]pyrene biodegradation and the amounts of phenolic compounds in root exudates increased when P. australis was exposed to pyrene. Our results show that Mycobacterium-root exudate interactions can accelerate biodegradation of pyrene and benzo[a]pyrene in P. australis rhizosphere sediments.     

Identification of benzo[a]pyrene quinone in soybean leaves

Soybean seeds (Glycine max) were grown in soil containing 10 ppm of benzo[a]pyrene (BaP). After 76 days growth, three kinds of quinones, namely BaP-1,6-, 3,6- and 6,12-quinones, were isolated and identified. However, the formative mechanism of the quinones in leaves has yet to be determined.     

Acute effects of Benzo[a]pyrene, anthracene and a fuel oil on biomarkers of the common goby Pomatoschistus microps (Teleostei, Gobiidae)

The objective of this study was to investigate the effects of two different PAHs and a complex petrochemical mixture on the common goby, Pomatoschistus microps, using selected biomarkers as effect criteria. Benzo[a]pyrene (BaP) and anthracene were used as reference substances, while the water accommodated fraction of #4 fuel-oil (#4 WAF) was used as an example of a petrochemical mixture. P. microps was used since it is both a suitable bioindicator and a good test organism. Groups of fish were exposed to different concentrations of each of the test substances for 96 h and the activities of several enzymes commonly used as biomarkers were determined at the end of the bioassays. All the substances inhibited P. microps acetylcholinesterase (AChE) indicating that they have at least one mechanism of neurotoxicity in common: the disruption of cholinergic transmission by inhibition of AChE. An induction of lactate dehydrogenase (LDH) activity was found in fish exposed to BaP or to anthracene, suggesting an increase of the anaerobic pathway of energy production. On the contrary, inhibition of LDH was found in fish exposed to #4 WAF, suggesting a distinct effect of the mixture. An induction of P. microps glutathione S-transferase (GST) activity was found in fish exposed to BaP or to #4 WAF, while an inhibition was observed after exposure to anthracene. These results suggest that GST is involved in the detoxification of BaP and #4 WAF, but not of anthracene. All the substances increased catalase activity and isolated PAHs also increased superoxide dismutase, glutathione reductase and glutathione peroxidase activities, while #4 WAF did not cause significant alterations on these enzymes. These results suggest that all the substances may induce oxidative stress on P. microps, with BaP and anthracene apparently having more oxidative stress potential than #4 WAF.     

Studies on oxidation of benzo [a] pyrene by sunlight and ozone

The destruction of the carcinogen benzo[a]pyrene (BaP) by light is well known; laboratory workers are routinely advised to cover fluorescent lamps with yellow filters while treating samples containing BaP. However until recently the mechanism of oxidation by sunlight and ozone had not been studied in detail. Concentrations of benzo[a]pyrene in urban air are in the range of 5–10 μg/1000 m³. Oxidant concentrations (predominantly in the form of ozone) are reported to be in the range of 0.01 ppm (22 μg per m³). Thus a sampling system with a filter paper would filter about 22,000 μg of ozone passing through and collect about 5 μg of BaP for analysis. The effect of interactions of such large ozone concentrations with BaP deposited on the filter paper is reported; data for the oxidation rates for benzo[a]pyrene coated on quartz surface and exposed to ozone or sunlight are presented. The oxidation products were analysed by thin-layer chromatography and highpressure liquid chromatography. From about eight products detected in these experiments, three have been identified as quinones based on UV-absorption spectrometry and mass spectrometry. Oxidation rates as high as 100% per hour of exposure are observed when less than 0.1 μg of BaP is coated inside the quartz tubes and exposed to ozone or sunlight. Oxidation rates for benzo[a]pyrene (using tritiated BaP) were determined for two types of experimental conditions. In the first set, tritiated BaP was spotted onto a glass fibre paper and sampling continued for 24 h; the loss of BaP was found to be 88%. In the second set tritiated BaP was spotted at intervals of one hour, for eight hours, while sampling is being carried out and the loss of BaP during the period was estimated to be 50%.     

玛咖提取物对氢溴酸东莨菪碱所致小鼠记忆获得障碍模型学习能力的影响

目的:观察玛咖提取物对氢溴酸东莨菪碱所致小鼠记忆获得障碍模型的影响。方法:100只昆明种小鼠随机平均分为空白对照组,模型组,吡拉西坦片组,玛咖高剂量组(1.17 g·kg-1)、低剂量组(0.585 g·kg-1),每天灌胃1次,连续灌胃20 d,空白对照组和模型组给予同体积的蒸馏水。各组以跳台法和电迷宫测试小鼠学习记忆的能力,用比色法测定小鼠脑组织胆碱乙酰转移酶(choline acetyl transferase,Ch AT)、乙酰胆碱酯酶(acetylcholin esterase,Ach E)活性,用碱性羟胺法测定乙酰胆碱(acetyl choline,Ach)含量。结果:玛咖提取物可减少小鼠跳台错误次数,提高电迷宫小鼠空间辨别正确次数,并能增加小鼠脑组织Ach含量和Ch AT活性,同时降低脑组织Ach E活性,有助于氢溴酸东莨菪碱所致小鼠空间学习记忆能力的改善。结论:玛咖提取物可以显著提高小鼠学习能力。     

大鼠孕期铅暴露对仔鼠空间记忆功能影响的研究

目的为探究大鼠孕期铅暴露对仔鼠空间记忆功能的影响。方法 40只SD大鼠受孕后随机分为4组,每组10只,3个染毒组自受孕第0 d起分别给予乙酸铅含量为125 mg/L(低浓度组)、250 mg/L(中浓度组)和500 mg/L(高浓度组)的饮水,对照组则给予蒸馏水。仔鼠出生后母鼠均换为蒸馏水,仔鼠21 d时与母鼠分笼饲养;采用示波极谱仪测定0、21及60 d仔鼠血、海马、大脑皮层(0 d仔鼠直接取全脑)铅含量;并对21 d及60 d仔鼠进行Morris水迷宫试验。结果 3个染毒组仔鼠的血铅、海马铅及大脑皮层铅含量在0、21、60 d均高于对照组(P<0.05),且染毒剂量愈高、仔鼠日龄愈小,铅含量愈高;21 d仔鼠水迷宫试验三染毒组的逃逸潜伏期均长于对照组(P<0.05)且高浓度组长于低浓度组。空间探索试验中通过平台的次数三染毒组亦少于对照组(P<0.05),且高浓度组少于低浓度组;60 d水迷宫试验中仅高浓度组的逃逸潜伏期长于对照组且空间探索试验中通过平台的次数少于对照组(P<0.05),而中、低浓度组与对照组亦无差异(P>0.05)。结论大鼠孕期铅暴露可使子代鼠血铅、海马铅及大脑皮层铅含量增高,并对仔鼠的学习记忆功能造成损伤,这种损伤可能随着仔鼠日龄增加有部分代偿作用。     

The use of manures for detection and quantification of polycyclic aromatic hydrocarbons and 3-hydroxybenzo[a]pyrene in animal husbandry

PAHs from a polluted atmosphere are generally transferred to plants by particle-phase deposition on the waxy leaf cuticle or by uptake in the gas phase through stomata. Thus, they are also present in ingredients for animal feed. Generally, toxic substances are metabolized before or after absorption through the intestinal tract. This is the case of 3-hydroxybenzo[a]pyrene, which can be found free or in its glucuronide and/or sulphate conjugate forms. This article develops a procedure to monitor the carry-over of PAHs from feed to food of animal origin based on the analysis of animal manure. Eleven PAHs and 3-hydroxybenzo[a]pyrene were measured in four animal manures (cow, horse, rabbit and pig) by liquid chromatography with fluorescence detection. benzo[a]pyrene, benzo[b]fluoranthene and benzo[k]fluoranthene were found in all the selected samples, but their total levels were not alarming (benzo[a]pyrene equivalents (microg/kg)<3.1). 3-hydroxybenzo[a]pyrene was quantified in all the samples exempting rabbit manure. The highest total PAH levels were detected in cow manure (9.0 microg/kg), while the highest 3-OH-B[a]P level was determined in horse samples (13 microg/kg).     

Influence of algal and bacterial particulate organic matter on benzo[a]pyrene bioaccumulation in Daphnia magna

In order to better asses the influence of organic matter on the bioavailability of hydrophobic organic contaminants, the effect of algae and POM of bacterial origin on the bioaccumulation of benzo[a]pyrene in Daphnia magna was evaluated. The bioaccumulation was monitored with increasing concentrations of particulate organic matter (POM) and dissolved organic matter (DOM). In all experiments, the presence of POM greatly reduced the bioaccumulation of benzo[a]pyrene. The reduction was more pronounced in the presence of algae, for which we observed a 99%-reduction effect in the presence of 6 x10 (5) cell/mL (equivalent to 5.3 mg C/L). The bioaccumulation of benzo[a]pyrene was decreased by 49% by organic matter of bacterial origin at 4.7 mg C/L. Assuming that benzo[a]pyrene was partitioned between water, DOM and POM and supposing that D. magna accumulated free benzo[a]pyrene via respiration and POM-bond benzo[a]pyrene via ingestion, bioaccumulation data allowed to estimate the dietary uptake rate of benzo[a]pyrene as well as partitioning coefficients K(POC) and K(DOC). Despite the ingestion of contaminated particles, we could not observe any dietary uptake of benzo[a]pyrene in daphnids. We verified, as usually supposed, that the bioaccumulation of benzo[a]pyrene to D. magna occurs mainly via direct contact. Very high partitioning coefficients (log K(POC) between 5.2 and 6.2) were estimated. This study pointed out the great influence of biogenic organic matter on the fate and the bioavailability of benzo[a]pyrene in aquatic ecosystems.