Objective To study the effects of fine particulate matter(PM1.0) surrounding urban road on the cerebral cortex and its oxidative stress level in rats. Methods A total of 50 SD rats were randomly divided into five groups: control group, saline group and low(1.5 mg/kg body weight), moderate(7.5 mg/kg body weight) and high(37.5 mg/kg body weight) dose group. The rats were anesthetized by ethyl ether, intratracheal instillation was used to expose PM1.0 suspension, once every other day, for3 times. Seven days later, the samples of cerebral cortex of every group were collected for pathological examination and determination of T-SOD, GSH-Px, T-AOC and MDA. Results The cerebral cortex tissues in moderate and high dose groups showed pathological changes, such as disorderly arranged cells, reduced cell number, karyopyknosis, chromatinolysis, and so on. Compared with the saline group, level of T-SOD and T-AOC in moderate group and high dose groups decreased significantly(P0.05), the level of MDA in moderate group and high dose groups increased significantly(P0.05). Conclusion Under the condition of this experiment, PM1.0 may cause tissue damage in cerebral cortex of rats, which may be associated with intensive oxidative stress.

目的 研究纳米二氧化钛染毒对大鼠脑皮层细胞内钙离了浓度([Ca2+]i)和钙蛋白酶1(calpain 1)表达的影响.方法 将50只健康SPF级雄性Wistar大鼠随机分为5组,分别为对照(蒸馏水)组和低(62.5 mg/kg)、中(125 mg/kg)和高(250mg/kg)剂量纳米二氧化钛染毒组及微米二氧化钛(250 mg/kg)染毒组,每组10只.采用灌胃方式进行染毒,每天1次,连续染毒60 d,测定大鼠脑皮层细胞内[Ca2+]和calpain 1的表达水平.结果 与对照组比较,仅高剂量纳米二氧化钛染毒组大鼠脑皮层细胞内[Ca2+]i升高,差异有统计学意义(P＜0.05);而低、中剂量纳米二氧化钛及微米二氧化钛染毒组大鼠脑皮层细胞内[Ca2+]i略有升高趋势,但差异均无统计学意义(P≥0.05).且随着纳米二氧化钛染毒剂量的升高,大鼠脑皮层细胞内[Ca2+]呈上升趋势.与对照组比较,纳米二氧化钛及微米二氧化钛染毒组大鼠腋皮层组织calpain 1表达水平略有升高趋势,但差异均无统计学意义(P≥0.05).结论 在本实验剂量下,纳米二氧化钛染毒可导致大鼠脑皮层细胞内[Ca2+]i升高,但并未影响calpain 1的表达.

目的 研究纳米二氧化钛对大鼠体内氧化应激水平及大鼠海马组织结构的影响.方法 将32只健康SPF级雄性Wistar大鼠随机分为4组,分别为对照(蒸馏水)组和低(250 mg/kg)、中(500 mg/kg)、高(1 000 mg/kg)剂量纳米二氧化钛组,每组8只.采用灌胃方式进行染毒,每天1次,连续染毒14d.分别在染毒第3、7、14天测定大鼠血浆中总超氧化物歧化酶(T-SOD)活力、谷胱甘肽过氧化物酶(GSH-Px)活力、总抗氧化能力(T-AOC)及丙二醛(MDA)含量;实验结束后,观察海马组织结构的变化.结果 与对照组比较,第3、7、14天高剂量纳米二氧化钛组血浆中T-SOD、GSH-Px活力和T-AOC均明显降低,MDA含量均明显升高;中剂量纳米二氧化钛组T-SOD活力在第3、14天明显降低,GSH-Px活力在第14天明显降低,T-AOC在第3天明显降低,MDA含量在第7、14天明显升高,差异均有统计学意义(P＜0.05);而低剂量纳米二氧化钛组以上4个指标均无显著改变.在各剂量纳米二氧化钛染毒组内,仅低、中剂量组第14天T-SOD活力显著低于第3天,差异均有统计学意义(P＜0.05).各染毒组海马区神经细胞出现不同程度的病理改变,如染色质溶解、核固缩、细胞密度降低等现象,中、高剂量组可见神经细胞坏死形成的空泡状区域.结论 本实验条件下,纳米二氧化钛染毒可引起体内氧化应激反应增强,并可导致大鼠海马组织结构损伤.

采用RT-PCR技术检测细胞内p53及bcl-2基因的改变,以观察六价铬[Cr(Ⅵ)]对人胚肺细胞(HEL)内癌基因和抑癌基因的影响及绿茶对其的拮抗作用.结果 显示,不同浓度的Cr(Ⅵ)溶液和绿茶浸泡液处理HEL细胞24 h后,5 μmol/L及10 μmol/L Cr(Ⅵ)单独处理组细胞内p53 mRNA和bcl-2 mRNA含量显著高于阴性对照组(P＜0.05).绿茶浸泡液处理组与Cr(Ⅵ)单独处理组相比,细胞内p53 mRNA和bcl-2mRNA含量降低(P＜0.05).提示六价铬可引起p53及bcl-2mRNA水平升高,绿茶浸泡液可以降低其表达水平.

Objective To explore the effects of gestation exposure to dibutyltin dilaurate (DBTD) on the activity of enzymes in the testis and the spermatogenesis function in the mature male offspring of Wistar rats. Methods The pregnant rats were treated with DBTD by gavage at the doses of 0, 10, 20 and 30 mg/kg for days, from 12th-20th days of gestation. On 70th postnatal day, 10 male offspring rats were selected randomly from each group for measurements of the viscera coefficient of testis and the sperm count in epididymis, the activity of enzymes of testis was determined by spectrophotometry. Results There were no significant differences seen in the body weight gain of pregnant rats from days 12-20 of gestation, litter size, sex ratio of fetuses and body weight of male offspring rats between the experimental groups and the control group. The testis weight and viscera coefficient of testis in 30 mg/kg group increased significantly compared with the control group(P0.01,P0.05).The sperm counts in 20 and 30 mg/kg groups were increased significantly compared with the control group(P0.05,P0.01). There was no significant difference seen in the activity of succinate dehydrogenase (SDH) and nitric oxide synthase (NOS) between the experimental groups and the control group. The activities of acid phosphatase (ACP) in 10 and 20 mg/kg groups, the activity of lactate dehydrogenase (LDH) in 10 mg/kg group and the concentration of nitric oxide (NO) in 30 mg/kg group were all significantly increased compared with the control group(P0.05). Conclusion DBTD has a promotive effect on the development of testis and the spermatogenesis in offspring rats within the length and concentration of exposure used in the present study, but no direct effect on testis enzymes activity.

邻苯二甲酸二(2-乙基己基)酯(DEHP)作为聚氯乙烯(PVC)等塑料制品的增塑剂,可增加塑料的弹性和韧性,被广泛应用于塑料工业.DEHP在塑料中是以游离的形式存在的,在重量上可达30%～50%[1],很容易进入环境.作为环境污染物,可以在地表水、地下水、饮用水、空气、土壤及动、植物体内广泛检测到.目前的研究发现其毒性作用主要是作为内分泌干扰物,表现为生殖生长毒性、肝肾毒性及血液和生化方面的改变.随着DEHP产量的逐年增加,其在环境中的浓度也逐渐升高,对人体的毒性作用也越来越受到人们的关注[2].目前对其健康效应方面的评价尚处于实验室动物研究阶段,本文仅就国内外DEHP的毒性研究作一综述.

Objective To study the influence of excessive magnesium and/or deficient calcium intake on the bone mass of ovariectomized rats. Methods Three-month-old ovariectomized rats were fed with different types of drinking water: Interaction group was fed with deficient-Ca and excessive-Mg water: Ca 5 mg/L, Mg 60 mg/L; Excessive-Mg group was Ca 60 mg/L, Mg 60 mg/L; Deficient-Ca group was Ca 5 mg/L, Mg 30 mg/L; Normal group was Ca 60 mg/L, Mg 30 mg/L. After 3 months of treatment, the left femur was measured with the length and weight, then the content of Ca and Mg were determined, right femur was X-rayed, and right tibia was taken for the pathological examination. Results Calcium deficiency in water caused significant changes in all of the bone mass indexes, magnesium excess in water showed a tendency of Ca decreasing and Mg increasing in the bone. It was easily distinguish the difference in bone mineral and bone microstructure by X-ray and pathological examination: control group was the best, then was Mg excess group, Ca deficiency group was inferior, and the interaction group was the worst. Conclusion Calcium deficiency is one of the major reasons of osteoporosis, while the excessive intake of magnesium may not only disturb the bone metabolism but also aggravate the adverse effect of Ca deficiency on bone mineral and bone health.

骨质疏松症是一种老年多发病.随着世界老龄人口的不断增长,骨质疏松的发病越来越多.资料显示,至1999年美国有2 500万人发生骨质疏松性骨折[1];2000年我国骨质疏松症患者约占全国人口总数的6.97%[2].骨质疏松一旦发病将不可治愈,给患者及其家庭带来沉重的经济负担,故应以预防为主.由于骨质疏松的确切发病机制至今尚不清楚,虽然世界各国每年均投入大量的财力、物力予以防治,但骨质疏松的发病率依然居高不下.

[目的]了解某酸化水洗衣机漂洗液的实验室消毒效果.[方法]参考卫生部2002年第4版<消毒技术规范>进行了定量杀菌试验和模拟现场试验.[结果]洗衣机漂洗液(酸化水)与金黄色葡萄球菌、大肠杆菌、铜绿假单胞菌和白色念珠菌分别作用8 min,平均杀灭率均达99.90%以上;分别作用16 min,平均杀灭率均达99.99%以上.洗衣机在满载状态下经1个自动洗涤程序(洗涤+漂洗),对人工染菌织物(棉布衣物)上的大肠杆菌平均杀灭率达99.83%.[结论]该洗衣机漂洗液(酸化水)具有较强的杀菌能力.