盐霉素高产菌的推理选育

根据盐霉素生物合成途径对其产生菌进行了推理选育。在常规诱变基础上选用丁酸作为筛选荆检出所需要的突变株，成功获得三株高产菌株3-233#、3-244#和3-250#，其效价比出发菌株F2—1#分别提高了34％、44．9％和39％。     

肺癌患者染色体稳定性及诱变剂敏感性的研究

目的 探讨细胞染色体不稳定性与肺癌的关系。方法 采用微量全血培养法对２４例经病理证实但未治疗的原发性肺癌患者、２０例非癌性患者和２０名健康志愿者外周血淋巴细胞（ＰＢＬ）进行自发和诱发的染色体畸变和微核检测。结果人肺癌患者ＰＢＬ自发及诱发染色体畸变率和微核率明显高于非癌性肺病患者和健康者;肺癌患者具有较高的染色体畸变率和微核率。肺癌患者染色体稳定性较差。结论 细胞染色体稳定性评价对肺癌的早期诊断、鉴     

头颈部肿瘤患者及其一级亲属对诱变剂的敏感性和人参茎叶皂苷Rg3的抗诱变作用

目的 :研究头颈部肿瘤的遗传因素及人参茎叶皂苷 Rg3的抗诱变作用。方法 :采用诱变剂敏感性实验检测肿瘤高危人群。结果 :患者组与一级亲属组中博莱霉素 ( BLM)所致的每细胞染色单体断裂率 ( chromatid breaks per cell,b/c值 )比较差异无显著性 ( P>0 .0 5 ) ,但明显高于健康对照组 ( P<0 .0 1 ) ,而人参茎叶皂苷 Rg3对 BLM所致的每细胞染色单体断裂率均有明显的抑制作用 ( P<0 .0 1 )。结论 :头颈部肿瘤患者的一级亲属应列为肿瘤易患高危人群 ,人参茎叶皂苷 Rg3可以提高机体抗癌能力     

Does ambient ozone pose a serious public health concern as a widespread environmental mutagen?

Based on bacterial, plant, animal and human studies, it is evident that O₃ is a general mutagen. However, there is still considerable uncertainty as to the extent to which O₃ is a human mutagen. Attempts to develop dose-response relationships have not yielded consistent results in the several studies thus far reported. At the present time there is a complete lack of data concerning human responses from ambient exposure. In light of the extent of the photochemical oxidant problem in the U.S. and the potential genetic effects of O₃, it is suggested that a major research effort be directed at both the elucidation of the potential mutagenic effects of O₃ as well as the implementation of effective oxidant control strategies.     

Induction of enzyme-altered islands in rat liver by tryptophan pyrolysis products

Summary Two new -carboline derivatives, 3-amino-1,4-dimethyl-5H pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H pyrido[4,3-b]indole (Trp-P-2), isolated from the pyrolysis products of tryptophan, were found to be potent mutagens. When weanling rats were injected with Trp-P-1 and then given diet containing phenobarbital, they developed enzyme-altered islands in the liver. Since these islands are considered to be formed by immediate progeny of initiated cells and cell precursors in hepatocarcinogenesis, Trp-P-1 may well be carcinogenic in rat liver.This work was supported in part by Grants-in-Aid for Cancer Research from the Ministry of Education, Science and Culture, and the Ministry of Health and Welfare, Japan     

Detection of 2-Amino-1-methyl-6-(4-hydroxyphenyl)imidazo[4,5-b]pyridine in Broiled Beef

2-Amino-1-methyl-6-(4-hydroxyphenyl)imidazo[4,5- b ]pyridine (4'-OH-PhIP) showed mutagenicity in Salmonella typhimurium TA98 in the presence of S9 mix, inducing 180 revertants per 100 μg. Since creatinine, tyrosine and glucose, which are present in meat, are expected to be involved in the formation of 4'-OH-PhIP, its presence in broiled beef was examined. 4'-OH-PhIP was detected in broiled beef by high-performance liquid chromatography and UV-spectrometry after extraction with 0.1 N HCl and purification by blue cotton treatment and ion exchange column chromatography. Its level was estimated to be 21.0 ng per g of broiled beef, which is comparable to that of 2-amino-1-methyl-6-phenylimidazo[4,5- b ]pyridine (PhIP).     

Neurospora mutants sensitive both to mutagens and to histidine

Summary Previous work in this and other laboratories showed that histidine strongly inhibits growth of mutants at ten out of 20 known mutagen-sensitivity loci in Neurospora, and that nine of the histidine-sensitive mutants disturb meiosis when homozygous. These and other results suggested that histidine affects recombination or DNA repair. Current work with the histidine-sensitive mutant uvs-6 shows that it is also inhibited by several other metabolites but none of them is as effective as histidine. On minimal medium without histidine or other inhibitors, uvs-6 first grows normally, then slows drastically and begins stop-start growth. Conidia from stop-start uvs-6 mycelia produce rejuvenated cultures. The stop-start growth, UV-sensitivity, histidine-sensitivity, and recessive meiotic characters of uvs-6 segregated together in crosses, and reverted together. In tests on other mutagen-sensitive mutants, sensitivity to histidine was strongly correlated with stop-start growth and with sensitivity to other metabolites. Histidine induces premature stop-start growth in at least two mutants. Several possible explanations for the histidine-sensitivity have been excluded.     

褪黑素对化学诱变剂诱发微核形成的保护作用

目的 通过体内和体外实验观察褪黑素(MT)对化学诱变剂诱发的人双核淋巴细胞微核和小鼠骨髓嗜多染红细胞微核形成的影响。方法 (1)以丝裂霉素(MMC)为阳性对照，观察用3种浓度MT预处理人淋巴细胞的双核细胞微核率；(2)以环磷酰胺(CP)为阳性对照，分别用3种剂量MT给小鼠灌胃，观察小鼠骨髓嗜多染红细胞的微核率。结果 (1)0．0l、0．10和1．00mmol／L MT MMC处理组的双核淋巴细胞微核率与MT浓度呈负相关；(2)0．1、1．0和10．0mg／kg MT CP处理组的小鼠骨髓嗜多染红细胞微核率均呈剂量依赖性降低。结论 MT呈现明显的抗诱变作用。     

蜂胶对诱变剂诱发基因突变的抑制作用

目的 探讨蜂胶对环磷酰胺等强诱变剂诱发基因突变的抑制作用。方法 应用Ames试验分别检测蜂胶对环磷酰胺（CP）、叠氮钠（NaN3)、正定霉素（DNR）、2－氨基芴（2－AF）诱发突变的抑制作用。结果 蜂胶对CP等4种诱变剂诱发的基因突变均产生抑制作用,且伴有剂量－反应关系;其中8－200μg/皿浓度蜂胶出现中等强度或以下的抑制（抑制率＜75．0％）,1000μg/皿浓度蜂胶对2－AF,NaN3,CP等3种诱变剂出现了强度抑制（抑制率分别为80．9％,79．7％,98．7％）,蜂胶本身无诱变活性。结论 蜂胶对CP等4种诱变剂诱发的不同类型的基因突变均有一定的抑制作用。     

蜂胶抑制诱变剂诱发基因突变及染色体损伤作用的研究

〔目的〕探讨蜂胶对诱变剂诱发的基因突变的抑制作用 ,对诱变剂诱发的染色体损伤的保护作用。〔方法〕应用Ames试验分别测试蜂胶对 2 -氨基芴 (2 -AF)、柔毛霉素 (DNR)、叠氮钠 (NaN3 )诱发的突变的抑制作用。应用小鼠骨髓微核试验及小鼠睾丸染色体畸变试验 ,测试蜂胶对诱变剂诱发的染色体损伤的保护作用。〔结果〕Ames试验发现40 0 0～ 12 0 0 0 μg/皿浓度蜂胶对 2 -AF、DNR、NaN3 三种诱变剂诱发的基因突变均产生抑制作用 ,抑制率分别为 5 6.8%、72 .2 %和 2 0 .8% ,且伴有剂量 -反应关系 ;小鼠骨髓微核试验发现 2 2 5mg/kg、675mg/kg 2个蜂胶剂量对环磷酰胺 (CP)引起的微核的发生产生了明显的抑制作用 ,抑制率分别为 2 0 .7%和 2 4.0 %。小鼠睾丸染色体畸变试验显示 ,675mg/kg蜂胶剂量对丝裂霉素C(MMC)引起的细胞染色体畸变有明显的抑制作用 ,抑制率为 3 1.5 %。〔结论〕蜂胶对 3种诱变剂诱发的不同类型的基因突变均有一定的抑制作用 ,对诱变剂引发的染色体损伤有保护作用。