室内常见气传真菌孢子的细胞毒性研究

分别以MTT比色法和细胞克隆形成率实验，观察了室内常见气传真菌孢子对中国仓鼠（CHL）肺上皮细胞的存活和增殖能力的影响，并通过检测细胞培养液中乳酸脱氢酶（LDH）活力，胞内Ca^2 ,K^ 含量，观察真菌孢子对细胞膜通透性的影响，结果表明，室内常见气传真菌孢子能显影响CHL细胞的活性，并可使细胞膜通透性发生改变，引起胞内LDH外渗，细胞内外离子发生交换，细胞内K^ 浓度降低，而细胞外的Ca^2 有内流的趋势。     

Immunotoxicity of bisphenol a to Carassius auratus Lymphocytes and macrophages following in vitro exposure

Bisphenol A （BPA） is the monomer component of polycarbonate plastics and classified as an endocrine disrupting chemical （EDC）. The reproductive toxicity of BPA has been extensively studied in mammals; however, relatively little information is available on the immunotoxic responses of fish to BPA. In this study, we investigated the effects of BPA on the immune functions of lymphocytes and macrophages in Carassius auratus. The effects of BPA were compared with those of two natural steroid hormones, estradiol and hydrocortisone. Proliferation of the two types of cells in response to PHA was measured using colorimetric MTT assay. Macrophage respiratory burst stimulated by Con A was measured using chemiluminescence assay. Results showed that BPA （0.054-5.4 mg/L）, estradiol （0.0002-2.0 mg/L） and hydrocortisone （5-50 mg/L） significantly induced Carassius auratus lymphocyte proliferation while higher doses of hydrocortisone （500-5000 mg/L） appeared to be inhibitory. BPA （0.005-50 mg/L）, estradiol （0.005-800 mg/L） and hydrocortisone （0.005-500 mg/L） markedly enhanced macrophage proliferation, whereas higher doses of BPA （500-1000 mg/L） appeared to inhibit cell proliferation. Furthermore, higher dosage of BPA （50 mg/L） and hydrocortisone （50 and 500 mg/L） suppressed the macrophages respiratory burst while estradiol is stimulative all the doses tested （0.05-500 mg/L）. In conclusion, BPA could have immunotoxicity to Carassius auratus and functional changes of lymphocyte and macrophage in Carassius auratus may be different between low and high dosages.     

Nanosilica exerts cytotoxicity and apoptotic response via oxidative stress in mouse embryonic fibroblasts

Nanoscale silica is an important industrial material and extensively used in medicines. The objective of this study was to determine potential cytotoxicity and genotoxic effects attributed to nanosilica exposure in mouse embryonic fibroblasts (L929) cells. Nanosilica produced mild cytotoxicity in L929 cells. Results showed that nanosilica increased thiobarbituric acid reactive substance levels and enhanced superoxide dismutase activity but decreased levels of glutathione. This was accompanied by a concomitant generation of reactive oxygen species, loss of mitochondrial membrane potential, and activation of caspase-3 activity. In addition, in the single-cell gel test, nanosilica (50–300 μg/ml) at two treatment times 24 and 48 hr produced concentration- and time-dependent increase of DNA damage. Therefore, the obtained results indicate that nanosilica may induce genotoxic effects in cultured L929 cells associated with induction of oxidative stress.     

Genotoxic and cytotoxic in vitro evaluation of ivermectin and its formulation ivomec® on Aedes albopictus larvae (CCL-126™) cells

Genotoxic effects of ivermectin (IVM) and its commercial formulation ivomec® (IVM 1.0%) were studied on Aedes albopictus larvae (CCL-126?) cells by sister chromatid exchange (SCE) and single cell gel electrophoresis (SCGE) while cytotoxicity was determined by cell-cycle progression (CCP), proliferative rate index (PRI), mitotic index (MI), 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and neutral red (NR) endpoints within a 1–250 µg mL^?1 concentration range. While IVM and ivomec® did not markedly affect SCE frequencies, these agents induced DNA-strand breaks enhancing both slightly damaged and damaged cells at 25–50 and 5–50 µg mL^?1 IVM and ivomec®, respectively. Both compounds exerted a delay in CCP and reduction of PRI at 10 µg mL^?1. Cytotoxicity was observed at concentrations higher than 25 µg mL^?1. A marked reduction of about 98% and 94% of MI compared to controls was noted with 25 µg mL^?1 of IVM and ivomec®, respectively. NR and MTT assays revealed that both compounds induced a cell growth inhibition within the 1–250 µg mL^?1 concentration range. Data indicated that IVM and ivomec® exert both genotoxicity and cytotoxicity in insect cells in vitro, at least in A. albopictus larvae CCL-126? cells.     

Cytotoxicity of single-walled carbon nanotubes,multi-walled carbon nanotubes,and chrysotile to human lung epithelial cells

Carbon nanotubes (CNTs) have found numerous applications in various industries. Recently, adverse effects of these materials on human and animal cells in vitro have been reported. In the present study, the cytotoxicity of single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), and chrysotile asbestos in human lung epithelial cells has been studied using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The cells were exposed for 6 h and 24 h to between 0.97 and 1500 μg mL^?1 of CNTs and chrysotile fibers prepared in two culture media containing 5% serum and 0.5% dimethylsulfoxide. Dose–response curves were obtained to determine the nonobservable adverse effect concentration and the half-maximum inhibitory concentration (IC₅₀). The way of dispersion affects the cytotoxicity of CNTs. For MWCNT, the toxicological indexes were lower than for SWCNT. Chrysotile fibers were even less cytotoxic than CNTs. Therefore, workplace control measures are recommended as priority for occupational and environmental conditions.     

孔雀石绿对三种鱼类细胞急性毒性的初步研究

应用MTT法测定孔雀石绿对鲤鱼上皮癌细胞(EPC)、草鱼肾细胞(CIK)、斑点叉尾鮰鱼卵巢细胞(CCO)的急性毒性。测定孔雀石绿的细胞毒性,发现MTT还原量减少,甲瓒生成量与孔雀石绿浓度存在依赖关系,孔雀石绿浓度越大,活细胞越少,甲瓒生成量也相应减少。以2×104接种量对EPC细胞、CIK细胞、CCO细胞进行24h染毒,发现随着孔雀石绿浓度的增高,细胞存活率减少,并确定孔雀石绿对这三种细胞的安全浓度、半致死浓度和致死浓度。比较这三种细胞对孔雀石绿的敏感性,得出结论CIK细胞对于孔雀石绿的作用最敏感。     

“活性甲醛”与甲醛远距离毒性的初步研究

甲醛是否具备远距离毒性(distant-site toxicity)是揭示甲醛与白血病关系的关键问题.本研究采用DPC、MTT实验方法检测甲醛的远距离毒性,结果发现当把等剂量的甲醛与GSH联合作用对细胞进行染毒后细胞内产生的DPC系数比单独同剂量的甲醛组要高很多,在MTT实验中发现在单独甲醛组中加入等量的GSH后细胞活性也出现了显著下降;在动物实验中,当对小鼠肝染毒后脑组织中也同样出现了损伤.说明甲醛在机体内与GSH形成了结合物,这种结合物可能协助甲醛完成跨膜并进入到局部组织再次释放出游离态甲醛,实现了甲醛的远距离毒性,这种结合态的甲醛称之为"活性甲醛".     

生物可降解材料PHBV的细胞毒性评价的研究

通过体外细胞毒性试验,对新型材料β-羟基丁酸与β-羟基戊酸共聚物(PHBV)的细胞生物相容性进行了研究.主要依据ISO10993及GB/T16886-1997的标准,应用四甲基偶氮唑盐(MTT assay)比色法对PHBV的细胞毒性进行评价.选用不同体积分数、不同温度下的PHBV材料浸提液为培养液,以及与PHBV材料直接接触培养来检测1d、3 d、5 d小鼠成纤维细胞BHK-21的相对增值率,确定PHBV材料的毒性程度.实验结果表明,PHBV材料即使在高温下其物理化学性质也很稳定;它的细胞毒性程度为0级,有着良好的细胞生物相容性.     

MTT法测定大肠杆菌活菌数实验研究

实验分析MTT比色法中的工作波长、反应时间、MTT用量、菌龄、二甲基亚砜（DMSO）等因素对大肠杆菌活细菌计数的影响.同时,通过与平板计数对比,确定了MTT细菌计数的可行性.结果表明,当细菌数在107～109cell·mL-1范围内时,双波长MTT法可用于检测大肠杆菌的活菌数量,最佳反应时间为60min,MTT溶液用量...     

11种取代酚类内分泌干扰活性的初步筛选与评价

通过聚蔗糖-泛影葡胺密度梯度离心法，从鲫鱼(Carassius auratus)外周血中分离出淋巴细胞，体外培养24h，用MTT法测试双酚类、联苯酚类、二酚类、烷基单酚类和取代酚类等几类可疑环境内分泌干扰物对淋巴细胞增殖的影响．结果表明，双酚类、联苯酚类和烷基单酚类物质对鲫鱼淋巴细胞的增殖具有低浓度促进，高浓度抑制的作用．二酚类物质对鲫鱼淋巴细胞的增殖具有促进作用．取代酚类对鲫鱼淋巴细胞的增殖无明显作用．该结果表明，此方法可以对环境内分泌干扰物进行初步筛选，同时发现环境内分泌干扰物对淋巴细胞增殖的效应与物质的化学结构具有一定相关性。