麦胚提取物对辐射损伤修复的实验研究

目的 研究麦胚提取物对小鼠辐射损伤修复的调节和保护作用。方法 采用辐射前或辐射同时饲喂一定量的麦胚提取物，观察小鼠经X射线一次性全身照射后的临床症状、30d存活率、骨髓微核率、外周血白细胞总数在不同时间的变化。结果 与对照组(单纯照射)比较，饲喂麦胚提取物可使小鼠的头面部皮肤、小肠黏膜、肾脏损伤症状得到明显改善；30d存活率为86．17％(P＜0．01)，提高存活率41．79％，保护系数为1．72；骨髓微核率4．62‰；比对照组(12．14‰)降低(P＜0．01)；外周血白细胞总数在7，13，20，30d均显回升(P＜0.05，P＜0．01，P＜0．01，P＜0．01)。结论 麦胚提取物对小鼠辐射损伤修复有一定程度的调节和保护作用，对于辅助肿瘤放射治疗具有重要意义。     

25％乙基硫环磷农药的诱变性研究

本文对新型有机磷农药，２５％乙基硫环磷进行了Ａｍｅｓ及微核两项诱变性试验研究。Ａｍｅｓ试验中，无论是否加入Ｓ９活化系统，２５％乙基硫环磷均未能诱发回变菌落数的增加；微核试验的各剂量组ＰＣＥ微核率也较低，（２‰～３‰），与阴性对照相比无显著性差异。     

Comparison of genomic damage caused by 5-nitrofurantoin in young and adult mice using the in vivo micronucleus assay

The antibiotic 5-nitrofurantoin (5-NF) has been used widely for the treatment of urosepsis in children during the last 20 years. Recent experimentation suggests the need for reevaluating its genotoxic potential. Because of possible differences in the metabolism and clearance of 5-NF in young and adult animals, we conducted a study to determine whether micronuclei caused by 5-NF were age-related. The in vivo micronucleus (MN) assay was performed on 3- and 8-week-old mice given single intraperitoneal injections of 5, 10, and 50 mg/kg 5-NF. Blood samples from the tail vein were taken before injection (baseline) and at 48, 96, 168, and 336 hr (2 weeks) after the treatment. One thousand reticulocytes were analyzed for micronuclei from each animal. Compared to similar baseline values for young and adult mice, 5-NF caused a significant increase in MN frequency in both age groups. The mean MN frequency in the young animals was higher than in the adult animals for each dose and sampling time. MN frequencies remained significantly elevated in young animals even 2 weeks after exposure to 5-NF. The results of the study confirm the genotoxic potential of 5-NF in young and adult animals, and indicate that young animals are more sensitive to the genotoxic effects of 5-NF than adult mice and that the response in young mice persists for a significantly longer time. These findings may be related to poorly developed mechanisms of xenobiotic detoxification and renal elimination in young animals.     

Induction of genotoxic damage is not correlated with the ability to methylate arsenite in vitro in the leukocytes of four mammalian species

Arsenic is a natural drinking water contaminant that impacts the health of large populations of people throughout the world; however, the mode or mechanism by which arsenic induces cancer is unclear. In a series of in vitro studies, we exposed leukocytes from humans, mice, rats, and guinea pigs to a range of sodium arsenite concentrations to determine whether the lymphocytes from these species showed differential sensitivity to the induction of micronuclei (MN) assessed in cytochalasin B-induced binucleate cells. We also determined the capacity of the leukocytes to methylate arsenic by measuring the production of MMA [monomethylarsinic acid (MMA(V)) and monomethylarsonous acid (MMA(III))] and DMA [dimethylarsinic acid (DMA(V)) and dimethylarsonous acid (DMA(III))]. The results indicate that cells treated for 2 hr at the G(0) stage of the cell cycle with sodium arsenite showed only very small to negligible increases in MN after mitogenic stimulation. Treatment of actively cycling cells produced induction of MN with increasing arsenite concentration, with the human, rat, and mouse lymphocytes being much more sensitive to MN induction than those of the guinea pig. These data gave an excellent fit to a linear model. The leukocytes of all four species, including the guinea pig (a species previously thought not to methylate arsenic), were able to methylate arsenic, but there was no clear correlation between the ability to methylate arsenic and the induction of MN.     

环磷酰胺、煤焦油对豫医无毛小鼠骨髓细胞微核的影响

目的探讨豫医无毛小鼠(YYHL)及昆明小鼠骨髓嗜多染红细胞自发微核率及化学诱变剂对其微核形成的影响.方法将小鼠分成6组,分别为YYHL组,昆明小鼠组,YYHL和昆明小鼠注射环磷酰胺组,及YYHL和昆明小鼠涂煤焦油组.采用骨髓嗜多染红细胞微核技术观察骨髓细胞微核率.结果①YYHL嗜多染红细胞自发微核率与正常昆明小鼠比较差异无显著性(P＞0.05).②腹腔注射环磷酰胺及煤焦油涂颈背部皮肤后,YYHL和昆明小鼠骨髓微核率均显著升高(P＜0.05),但2组比较差异无显著性(P＞0.05).结论YYHL对煤焦油及环磷酰胺致突变作用的反应与昆明小鼠一致,是一种评价化学物遗传毒性的有效动物模型.     

激光照射对小鼠骨髓细胞微核率的影响

目的　研究激光照射的生物效应。方法　采用低能量He Ne激光照射小鼠 ,每天 1次 ,每次 10min ,照射 7天后 ,处死小鼠。测定小鼠骨髓嗜多染红细胞微核的出现率。结果　经低能量He Ne激光照射的小鼠的细胞微核率与对照组比较无差异 (P >0 .0 5 )。结论　受低能量He Ne激光照射后小鼠骨髓嗜多染红细胞微核率无显著增加 ,治疗用低能量的He Ne激光不会致突变     

泡桐刨花用作实验小鼠垫料的研究

泡桐茎高大 ,通气组织蓬松 ,富含纤维。测定 4 8h吸水量 ,每克泡桐刨花吸水 3.31± 0 .2 4g ,椴木刨花吸水 3.4 2± 0 .18g ,两者差异无显著性 (P >0 .0 5)。但高于玉米棒芯吸水量 2 .4 3± 0 .17g(P <0 .0 5)。不同年龄小鼠 (指孕鼠、乳鼠、青年鼠 )对泡桐刨花垫料的适应性均较好 ,生长发育和繁殖良好。以泡桐刨花作垫料 ,饲养的KM小鼠在 6个月和 12个月时 ,活体骨髓多染性红细胞微核率分别为 ( 3.2 6± 0 .37)‰和( 3.60± 0 .4 5)‰ ,均在正常范围之内。表明泡桐刨花垫料没有致畸作用。     

烹调油烟冷凝物遗传毒性实验研究

目的研究胡麻油烟冷凝物对小鼠致突变作用。方法采用不同剂量胡麻油烟冷凝物灌胃染毒小鼠,通过微核实验和精子畸形分析,观察微核率和精子畸形率变化。结果各染毒组微核率和精子畸形率均明显高于阴性对照组和胡麻油对照组(P＜0.01),并呈现剂量反应关系(P＜0.05)。结论在上述两实验系统中,胡麻油烟冷凝物具有明显的致突变作用。     

内燃机车乘务员和轮轴工外周血淋巴细胞微核观察

本文作者对５１名内燃机车乘务员和车辆维修车间的３０名轮轴工外周血淋巴细胞微核进行了分析。结果表明,机车乘务员和轮轴工微核阳性检出率、微核细胞率和微核率均明显高于对照组（Ｐ＜０．０１）,而且随着作业工龄的延长,微核细胞率和微核率有接近显著（０．０５＜Ｐ＜０．０１）或显著（Ｐ＜０．０５）意义的增高。对两类作业工作人员微核增高的原因进行了讨论     

山慈菇抑制镉诱发遗传损伤研究

采用活体小鼠骨髓嗜多染红细胞（ＰＣＥ）微核试验（ＭＮＴ）,观察中草药山慈菇（ＢｕｌｂｕｓＩｐｈｉｇｅｎｉａｅ）水溶性提取物的诱变作用及对镉（Ｃｄ）、环磷酰胺（ｃｐ）的抗诱变作用。结果表明：山慈菇可以诱发微核（ＭＮ）产生,但其诱变作用不强;山慈菇对Ｃｄ及ｃｐ的诱变作用具有明显的抑制效果,并对Ｃｄ的抑制作用明显强于对ｃｐ的抑制作用。