秋水仙碱引起CHL细胞有丝分裂纺锤体损伤的观察

用同时显示有丝分裂纺锤体和染色体的分化染色技术，对不同浓度秋水仙碱诱发的ＣＨＬ细胞纺锤体损伤作了观察。实验结果表明，随着秋水仙碱浓度的增加，纺锤体形态完整的分裂相明显减少，当秋水仙碱浓度达到０．１μｇ／ｍｌ时，纺锤体完全缺如，分裂细胞全部为无极分裂相。文中对与文献报告不同的观察所见，例如低浓度秋水仙碱处理时仍可见到形态基本正常的纺锤体，以及对多极纺锤体进行了初步的讨论。     

毛蚶提取物的遗传毒性试验研究

目的 评价毛蚶提取物的遗传毒性,为评价其安全性提供毒理学依据。方法 选用体外细菌回复突变(Ames)试验、中国仓鼠肺细胞(CHL)体外染色体畸变试验、小鼠骨髓嗜多染红细胞微核试验,进行毛蚶提取物的遗传毒性研究。Ames试验设5000.0、2500.0、1250.0、625.0、312.5 μg/皿5个剂量;体外CHL细胞染色体畸变试验,设立5.00、2.50、1.25 mg/mL 3个剂量,毛蚶提取物与CHL细胞分别接触6、24 h;小鼠骨髓微核试验,设立5000、2500、1250 mg/kg 3个剂量,给药1次。结果 Ames试验,毛蚶提取物在加与不加S9时各剂量组回变菌落数均未超过自发回变菌落数的2倍,亦无剂量相关性,结果为阴性;CHL染色体畸变试验,毛蚶提取物代谢活化组和非代谢活化组的染色体畸变率均低于5%,染色体畸变试验结果为阴性。小鼠骨髓微核试验,各剂量组的微核率与阴性对照组比较,差异不显著,结果为阴性。结论 在本试验条件下,毛蚶提取物未见潜在的遗传毒性。     

体内外染色体畸变实验检测朱砂的遗传毒性

目的:用仓鼠的骨髓细胞与CHL细胞经行体内外染色体畸变实验评价朱砂的遗传毒性。方法:体内染色体畸变实验用毛足属仓鼠给予朱砂混悬液(2.0,4.0,8.0 g·kg-1)连续灌胃5 d,处死前2 h腹腔注射秋水仙素。处死后取骨髓细胞制备染色体。油镜下观察每只动物骨髓细胞的有丝分裂指数和100个中期分裂相细胞的畸变类型。CHL细胞染色体畸变实验用朱砂浸出液终质量浓度为6.3,12.5,25.0 g·L-1作用于CHL细胞,培养24,48 h,终止培养前4 h加入秋水仙素。收获细胞,制备染色体,油镜下观察CHL细胞的200个中期分裂相细胞的畸变类型。结果:(1)与空白组比较,朱砂浸出液12.5,25.0 g·L-1给药组的CHL细胞染色体畸变率均升高(P0.05,P0.01),且有明显的量效关系。(2)仓鼠体内实验与朱砂血清给药CHL细胞的畸变率无显著性差异。结论:(1)在本实验中朱砂浸出液在12.5 g·L-1以上时能致体外CHL细胞染色体畸变,而朱砂混悬液在8.0 g·kg-1下仓鼠体内染色体畸变实验未出现阳性结果。(2)仓鼠体内染色体畸变实验可作为研究中药新药遗传毒性评价实验方法之一。     

氟康唑的致突变研究

本文报道用Ａｍｅｓ试验、微核试验和体外培养中国仓鼠肺细胞（ＣＨＬｃｅｌｌｓ）染色体畸变试验检测氟康唑（ＦＣＺ）致突变作用的结果：ＦＣＺ浓度达５００μｇ／皿，不论加与不加Ｓ９代谢活化系统，对各菌株均无诱发回复突变作用；２００ｍｇ／ｋｇ腹腔注射，未引起小鼠骨髓多染红细胞微核率增加；在２００ｇ／ｍｌ浓度下，不论是否经Ｓ９代谢活化，均未导致ＣＨＬ细胞染色体畸变。     

Single-chain variable fragment antibodies against the neural adhesion molecule CHL1 (close homolog of L1) enhance neurite outgrowth

The neural cell adhesion molecule CHL1 (close homolog of L1) plays important roles in neurite outgrowth and neuronal survival in vitro. Reproducible and functionally active CHL1 antibodies are critical for a better understanding of the functional properties of CHL1 in vitro and in vivo. We have isolated human single-chain variable fragment (scFv) antibodies against mouse CHL1 from a human synthetic phage display library. To improve the binding activity of such antibodies, a clone (C12) was selected for affinity maturation by combined random mutagenesis of the V(H) gene and site-directed cassette mutagenesis to introduce random mutations in the complementarity determining region 3 (CDR3) of the V(L) gene. From the mutant phage display library, we selected a clone (6C2) that gave the strongest signal as determined by ELISA. The dissociation constant of 6C2 (Kd 2.28 x 10(-8) M) was increased approximately 85-fold compared with the wild-type clone C12 (Kd 1.93 x 10(-6) M). 6C2 detected CHL1 by Western blot analysis in mouse brain homogenates and detected CHL1 in CHL1-transfected cells by immunofluorescence. Furthermore, the wild-type and affinity-matured antibodies promoted neurite outgrowth of hippocampal and cerebellar neurons in vitro. Our results suggest that the affinity-matured CHL1 scFv antibody will serve a range of applications in vitro and in vivo.     

SO2致CHL细胞氧化损伤及VC保护作用

目的探讨二氧化硫（SCh）对哺乳类细胞的毒性作用及其防护。方法以SCh体内衍生物一亚硫酸盐和亚硫酸氢盐（分子比为3：1）及抗坏血酸（维生索C，VC）单独或同时处理中国仓鼠肺成纤维细胞（CHL），并分别测定过氧化氢酶（CAT）、超氧化物歧化酶（SOD）活性及脂质过氧化（LPO）水平。结果（1）SO2体内衍生物单独处理后。CAT活性在12，24h时显著降低；36h时，除5mmol／L组外，其余各组均极显著降低；48h时15，20mmol／L组与对照组比较。差异有统计学意义（P〈0．01）。除12h时的5mmol／L组外，其余各组LPO水平在处理12，24h时均明显升高。（2）VC单独处理后，各组CAT活性只在12h时显著升高，同时LPO水平降低，但是只有0．10，0．25mmol／L组与对照组比较，差异有统计学意义（P〈0．05）。（3）0．1mmol／L VC和不同剂量SO2衍生物共同处理后，CAT活性仍然呈下降趋势。但加添VC的组CAT活性普遍高于相应的未加VC组，且培养12h的5，10mmol／L组及24h的10，15mmol／L组与未添加VC组比较，差异有统计学意义（P〈0．05）；VC也降低了SO2衍生物引起的LPO水平。（4）在CHL细胞中未检测到SOD。结论SO2体内衍生物可以使CHL细胞中CAT活性降低、LPO水平增高。且VC可起到一定防护作用。     

爱宁的致突变作用研究

目的检测爱宁的致突变性,以提供有关致突变的遗传毒性安全评价数据。方法设1.6,8,40,200和1000μg/皿5个剂量组,进行Am es试验;设0.3,1,3和9μg.mL-14个剂量组,进行仓鼠肺成纤维细胞染色体畸变试验;设15,100和250 mg.kg-13个剂量组,观察其对小鼠骨髓细胞微核的影响。结果Am es试验表明,爱宁在加和不加S9的条件下,对TA97,TA98,TA100和TA102菌株回复突变菌落结果为阴性。仓鼠肺成纤维细胞染色体畸变试验表明,爱宁对中国仓鼠肺成纤维细胞体外培养染色体无畸变作用。小鼠骨髓细胞微核试验表明,爱宁三个剂量组的微核出现率与阴性对照组比较无显著性差异。结论在本实验条件下,爱宁无致突变性。     

CHL细胞DNA解螺旋荧光分析法实验参数的选择及其应用

为确定ＣＨＬ细胞２为测试靶细胞时ＦＡＤＵ较佳实验参数的采用变化解旋温度及解旋液碱浓度，产根据Ｂｉｒｎｂｏｉｍ等的判断标准，结果表明解旋温度先中℃３０ｍｉｎ后１５℃６０ｍｉｎ，解旋液ＮａＯＨ浓度０．４Ｎ效果较佳。并以此为条件马该法应用于检测过氧化氢诱导的ＤＮＡ过氧化损伤－适应及抗过氧化作用，结果证明了所选用参数的可靠性。     

Safety evaluation of Elsholtzia splendens extracts: assessment of acute toxicity and mutagenicity.

Much attention is recently gained for Elsholtzia splendens extracts and issue on their usage is raised due to their biological properties. However, there is no sufficient background information on toxicological evaluation of E. splendens extracts to give an assurance of safety for developing dietary supplements and functional foods. The objective of this study was to evaluate safety on E. splendens extracts using acute oral toxicity, bacterial reverse mutation, and chromosome aberration test. Total flavonoids within E. splendens were extracted with 80% of methanol by a reflux condenser. Both female and male mice were orally administrated E. splendens extracts at the dose of 0, 500, 1000, and 2000 mg/kg body weight/day. Mutagenicity of the extracts was evaluated in a bacterial reverse mutation assay using histidine requiring Salmonella typhimurium (TA 98, TA 100, TA 1535, and TA 1537) and tryptophan-requiring Escherichia coli (WP2uvrA). In vitro chromosome aberration assay in Chinese Hamster Lung (CHL) was conducted to evaluate genotoxicity. Single administration of dose levels of 500, 1000, and 2000 mg/kg body weight/day to mice for 15 days did not produce any significant mortality, clinical signs, body weight loss, and gross findings. E. splendens extracts in the range of 156.3-5000 microg/plate did not induce mutagenicity in S. typhimurium and E. coli with and without metabolic activation system. Any significant chromosomal aberration was not observed in CHL cells 6h after treating with the extract at the concentrations of 1250, 2500, and 5000 microg/mL in absence and presence of metabolic activation system. However, frequency of chromosomal aberration in 22 h after treatment without metabolic activation system was increased with showing a pattern of dose-response relationship. The highest concentration of 5000 microg/mL significantly induced chromosomal aberration. E. splendens extracts may induce chromosomal structure abnormality in CHL cells. This study suggests that further study is needed to assess the potential genotoxic effects of E. splendens extracts.