碘对体外人淋巴细胞染色体的影响

目的　研究碘对体外人淋巴细胞染色体的影响。方法　用不同浓度的碘化钾溶液处理培养中的淋巴细胞 ,观察其姐妹染色单体交换 (sisterchromatidexchange ,SCE)频率和微核率的变化 ,并分别用t检验和 χ2 检验方法作显著性检验。结果　培养液中碘剂量在 2 μg/ml 时 ,SCE频率和微核率都显著低于对照组(P <0 0 5 ) ;培养液中碘剂量在≥ 2 0 μg/ml时 ,SCE频率和微核率都显著高于对照组 (P <0 0 5 )。结论　适量的碘可以降低SCE频率和微核率 ,对遗传物质具有保护和抗突变作用 ;而 2 0 μg/ml以上的高剂量碘可显著增高SCE频率和微核率 ,对遗传物质具有程度不同的损伤作用     

石棉诱发人外周血淋巴细胞姐妹染色单体交换分析

目前普遍认为,姐妹染色单体交换(SCE)是染色体损害和修复的指标。业已证实SCE是揭示化学诱变剂和致癌物质对染色体作用的极为敏感的指标。1974年,Late研究丝裂霉素C对人的淋巴细胞作用时,发现低得不能使染色体畸变增高的浓度,仍可使SCE有明显的增高,从此SCE的方法被建议用于监测诱变剂对哺乳类染色体的作用。由于SCE的计数容易,正确,观察染色体畸变敏感,它要求的诱变剂的浓度远远低于引起染色体畸变的浓度,且发生率高,观察的细胞数较少,故近年来     

烟煤和无烟煤及褐煤粉尘致突变实验研究

目的探讨烟煤尘、无烟煤尘及褐煤尘的致突变作用。方法分别用烟煤、无烟煤和褐煤粉尘的二甲基亚砜混悬液，作鼠伤寒沙门氏菌回复突变（Ames）和姐妹染色单体交换（SCE）试验。Ames试验采用TA97、TA98、TA100和TA102菌株，并将3种煤尘各分为5000、500、50和5μg／皿4个剂量组；SCE试验采用健康成人外周血淋巴细胞，煤尘样品分为500、50和5μg/皿3个剂量组。各剂量组均设3个平行样。试验分为加与不加体外代谢活化系统（S9）两部分，同时设阴性和阳性对照组。Ames试验在细菌培养（37℃）48h后计算回变菌落数；SCE试验在标本37℃培养72h后制成染色体标本玻片，油镜下观察计数细胞第二增殖周期分裂相的SCE频率。结果3种煤尘在加S9与不加S9时，其菌落数均不超过自发回变菌落数的2倍，而且均不能使SCE频率明显升高。结论在本实验条件下，烟煤尘、无烟煤尘及褐煤尘均未见致突变作用。     

汽车尾气对小鼠骨髓细胞的致突变性

目的探讨汽车尾气对小鼠骨髓细胞的致突变性。方法健康昆明种小鼠100只,随机分10组,雌雄各半。用汽车尾气分别染毒15、30、45、60d后,观察小鼠骨髓细胞微核率和姐妹染色单体交换率变化,并与正常饲养组小鼠骨髓细胞进行比较。结果各染毒组与对照组之间的微核率、姐妹染色单体交换率有差异,除15d组和对照组的差异无显著性(P>0.05)外,其他各组和对照组比较,差异均有显著性(P<0.01);且染毒时间对小鼠骨髓细胞的致突变影响呈正相关。结论汽车尾气对小鼠骨髓细胞有致突变性。     

溴氰菊酯毒性和致突变性的研究

目的　了解溴氰菊酯的毒性、刺激性、蓄积毒性、致敏性和致突变性。方法　按标准方法分别作大小鼠急性经口毒性 ;大鼠经皮、吸入毒性 ;皮肤、眼刺激性 ;大鼠蓄积毒性和亚慢性经口毒性试验 ;豚鼠致敏试验 ;致突变试验包括Ames、小鼠骨髓微核和睾丸精母细胞染色体畸变试验。结果　大小鼠急性LD50 分别为 2 78mg/kg和 5 6 2mg/kg ;大鼠经皮LD50 >2 0 0 0mg/kg ;急性吸入LC50 >3 0 0 0mg/m3 ;无皮肤刺激性 ,轻度眼刺激性 ;蓄积系数 2 3 ;致敏率为 0 ;Ames试验结果阴性 ;微核和染色体在高剂量组 ( 11 2 4mg/kg)与阴性对照组相比有高度显著性差异 (P <0 0 1) ;大鼠 90天亚慢性经口的最大无作用剂量为 2 82 5mg/kg。结论　溴氰菊酯有明显的蓄积作用 ,为弱致敏物 ,一定剂量下可引起骨髓微核和睾丸精母细胞染色体畸变率增加 ,提示它是一种可能致突变物     

黄体酮注射孕兔对其子兔染色体影响的研究

本文研究了黄体酮的诱变效应。试验结果表明,孕兔接受黄休酮注射可以引起子兔姐妹染色单体交换(SCE)频率和微核(MN)率增高。黄体酮诱导的 SCE 频率增高,停药一个月可以恢复。并探讨了黄体酮诱变作用的机制。     

锰对人外周血淋巴细胞微核率和姊妹染色单体交换频率的影响

目的：探讨锰对正常人外周血淋巴细胞微核率和姊妹染色单体交换（SCE）频率的影响。方法：用不同浓度的硫酸锰溶液（培养液中锰浓度：0．05，0．15，0．25，0．75，1．50μg/ml）处理体外培养的人外周血淋巴细胞，观察其微核率和SCE频率的变化，同时以生理盐水为对照。结果：锰剂量≤0．25μg/ml时，实验组与对照组相比，其微核率和SCE频率变化均不显著（P＞0．05），锰剂量≥0．75μg/ml时，微核率和SCE频率均显著高于对照组（P＜0．01），且呈剂量－反应关系，结论：0．25μg/ml以下低剂量锰对细胞遗传物质是比较安全的，而0．75μg/ml以上高剂量锰可造成不同类型DNA损伤。     

游离余氯的致突变性研究

为了研究游离余氯的致突变性,选用近年来广泛用于检测环境污染物致突变性的蚕豆根尖微核技术,对不同浓度的游离余氯的致突变性进行了对比实验研究。研究结果表明：游离余氯浓度在０．０２～０．８０ｍｇ／Ｌ范围内均具有致突变性。游离余氯的致突变性随着浓度的升高而逐渐增强,呈明显的剂量反应关系（ｔｒ＝４．１０２,Ｐ〈０．０２５）。研究结果提示：游离余氯具有致突变性,它的致突变性应引起人们的高度重视。     

污水养殖水的致突变性研究

目的 探讨污水养殖水的诱变效应。方法 采用蚕豆根尖细胞微核试验及鱼外周血红细胞微核试验对排污河污水及经氧化塘预沉淀后用于生物养殖的污养水和污水养殖鱼迸行研究,以水库水样及鱼样为对照。结果 蚕豆根尖细胞微核试验表明,排污河污水、污养水的微核率明显高于对照组（P<0.01）。而清养水样与阴性对照组（蒸馏水）间差异无显著性（P>0.05）。污养鱼外周血红细胞微核率显著高于清养鱼（P<0.01）。结论 排污河污水、污养水中含有致突变物质,可通过食物链对人体产生潜在的危害。     

兰州地区大气悬浮颗粒物对人体外周血淋巴细胞姐妹染色单体交换的影响

采用人体外周血淋巴细胞体外培养的方法，对兰州市不同地区５个采样点大气总悬浮颗粒物（ＴＳＰ）有机提取物进行了姐妹染色单体交换（ＳＣＥ）试验。结果表明，５个样品对ＳＣＥ率均有不同程度的影响，并具有较好的剂量－反应关系。其中铁路局和西固点ＳＣＥ率增高尤为显著，对照点榆中则增高微弱。     

不同剂量的K2Cr2O7对细胞膜通透性的影响

目的研究不同剂量的 Ｋ２Ｃｒ２Ｏ７对细胞膜通透性的影响。方法采用人胚肺细胞的乳酸脱氢酶的漏出。Ｋ＋漏出以及豚鼠红细胞溶血率等三种方法测定 Ｋ２Ｃｒ２Ｏ７对细胞膜通透性的影响。结果小于 ５μｍｏｌ／Ｌ浓度的 Ｋ２Ｃｒ２Ｏ７未造成细胞膜通透性的改变。结论低浓度Ｋ２Ｃｒ２Ｏ７对细胞损伤的靶点不是细胞膜。     

Detection of Ehrlichia spp. and Anaplasma phagocytophilum in whole blood specimens using a duplex real-time PCR assay on the ARIES instrument

Cases of tick-borne diseases are increasing in the United States, and new tick-borne pathogen species causing human illness are being discovered. The specific etiology is generally difficult to diagnose based on clinical signs and symptoms alone, because of their generalized nature and often lack of a known tick bite. For some infections, such as Lyme disease and spotted fever group rickettsioses, serology remains the most appropriate laboratory diagnostic tool, but for others such as anaplasmosis, ehrlichiosis, and babesiosis, direct detection in the blood is preferred for rapid diagnosis. In Kentucky, USA, the area served by our laboratory, the most commonly reported tick-borne illnesses include spotted fever group rickettsiosis, ehrlichiosis and Lyme disease, but of these three diseases, only ehrlichiosis is well-suited for direct detection using PCR methods during the acute stage of illness. We report here the validation of a duplex real-time PCR assay using whole blood specimens on the Luminex ARIES® instrument, combining DNA extraction, amplification and detection into a one-step process. This method allows for rapid and sensitive detection of acute infections with Ehrlichia spp. and Anaplasma phagocytophilum using whole blood specimens. We included A. phagocytophilum to monitor emergence of this pathogen in Kentucky, since surrounding states have reported many more cases than Kentucky.     

原子荧光光谱法测定奶牛全血和鲜牛乳中痕量锗与硒的方法研究

应用氢化物发生原子荧光光谱法 (HG-AFS)测定奶牛全血及鲜牛乳中的锗和硒 ,具有取样量少、成本低、简便、准确、精密度好等优点 ,适用于农业、医学、环境等科研领域开展微、痕量元素的研究与应用。方法干扰少 ,分析灵敏度高 ,线性关系良好 ,锗、硒的检出限分别可达到 :1 .2 ng/ml,0 .3 3 ng/ml,相对标准偏差分别为 :2 .6% ,3 .8%。     

新疆哈萨克族食管癌患者全血及头发中微量元素的分析

<正> 微量元素与肿瘤的发生、发展及治疗有密切的关系。新疆哈萨克族食管癌患病率较高,为了探讨食管癌与微量元素的关系,我们于1990年8月至1992年7月对新疆部分哈萨克族食管癌高发区患者全血及头发中部分无机元素含量进行了测定。材料与方法1.样品采集:选用新疆新源县及阿勒泰地区食管癌高发区,经病理细胞学检查确诊为食管癌患者     

子痫前期患者外周血共刺激分子B7-1和B7-2的表达水平

目的:研究子痫前期患者外周血单核细胞共刺激分子B7-1和B7-2的表达水平,探讨B7-1、B7-2在发病中的作用。方法:收集20例重度子痫前期患者、20例轻度子痫前期患者、20例妊娠期高血压患者、20例正常妊娠妇女、20例正常未孕妇女的外周血单核细胞,用流式细胞技术检测B7-1、B7-2的表达率。结果:①正常妊娠时B7-2(27.04±9.88)表达水平升高,B7-1(6.00±1.84)表达处于低水平(P<0.01);②重度子痫前期组B7-1表达率和轻度子痫前期组B7-1表达率均显著高于其他各组(P<0.01)。结论:子痫前期患者外周血单核细胞共刺激分子B7-1、B7-2异常表达在其发病中具有重要作用,可能是子痫前期发生的重要原因。     

Effect of a low-dose ethinylestradiol and gestodene in combination on the frequency of micronuclei in human peripheral blood lymphocytes of healthy women in vivo

BACKGROUND: Since most oral hormonal contraceptives contain a fixed combination of ethinylestradiol and gestodene as an estrogenic/progestogenic component, we decided to evaluate the possible mutagenic effect of a low-dose contraceptive pills containing 20 microg ethinylestradiol and 75 microg gestodene. METHODS: A total of 30 healthy women received hormonal contraception during six consecutive menstrual cycles. A single daily dose was 20 microg ethinylestradiol and 75 microg gestodene. The pills were taken orally in a monthly cycle of 3 weeks on and 1 week off. In the investigation of the mutagenic effect of these contraceptive pills in vivo, the cytokinesis block micronucleus (CBMN) test was used, and the frequency of micronuclei (MN) in peripheral blood lymphocytes was determined. RESULTS: Average MN frequency in women before therapy was 7.40 +/- 0.75 MN/1000 analyzed cells, and after therapy was 7.37 +/- 0.59 MN/1000 analyzed cells (p > 0.05). CONCLUSION: Our data suggest that oral contraception with 20 microg ethinylestradiol and 75 microg gestodene in combination during six consecutive menstrual cycles does not induce micronuclei in peripheral blood lymphocytes of women.     

Contrasting effects of age on the plasma/whole blood lead ratio in men and women with a history of lead exposure

We examined the effect of age and sex on the relationship between the concentrations of Pb in blood (Pb-B) and in plasma (Pb-P) in an adult population with a history of lead exposure. Pb-P was determined by inductively coupled plasma mass spectrometry (ICP-MS) and Pb-B by graphite furnace atomic absorption spectrometry (GF AAS). We studied 154 adults (56 men and 98 women) from 18 to 60-year old. Pb-B levels varied from 10.0 to 428.0 microg/L, with a mean of 76 microg/L. Blood lead levels varied from 10.0 to 428.0 microg/L in men (mean, 98.3 microg/L) and from 10.0 to 263.0 microg/L (mean, 62.8 microg/L) in women. Corresponding Pb-Ps were 0.02-2.9 microg/L (mean, 0.66 microg/L) and 0.02-1.5 microg/L (mean, 0.42 microg/L) in men and women, respectively. The relationship between Pb-B and Pb-P was found to be curvilinear (r = 0.757, P < 0.001 Spearman's correlation). The two quantities are related by the line y = 0.0006x(1492) (y = Pb-P, and x = Pb-B). The %Pb-P/Pb-B ratio ranged from 0.03% to 1.85%. A positive association was found between %Pb-P/Pb-B ratio and Pb-B levels. When data were separated by sex, this association was also relevant for men (y = 0.0184x(0.702)) and women (y = 0.0534x(0.5209)) (y = %Pb-P/Pb-B and x = Pb-B). Moreover, we found an interesting positive correlation between Log (Pb-P/Pb-B) and age for women (r = 0.31, P < 0.0001) and a negative correlation for men (r = -0.164, P = 0.07). Taken together, these results suggest contrasting effects of age on the plasma/whole blood lead ratio in men and women with a history of lead exposure. Moreover, sex might play an important role in the metabolism of lead, implying further consideration on the kinetic models constructed of lead toxicity.     

儿童血压与尿中TXB_2、PGI_2排出量关系的探讨

采用病例－对照的研究方法，对济南市区６所小学的８～１０岁血压偏高的儿童进行了４ｈ尿中血栓素Ｂ２（ＴＸＢ２）、前列环素（ＰＧＩ２，放射免疫法）排出量的对比观察。结果发现，血压偏高组儿童尿中ＴＸＢ２排出量高于血压正常组，而ＰＧＩ２排出量则低于血压正常组。单因素相关分析结果，儿童血压（收缩压）与尿中ＴＸＢ２排出量呈正相关（ｒ＝０．２２，Ｐ＜０．０５）与ＰＧＩ２的排出量呈负相关（ｒ＝－０．２５，Ｐ＜０．０５）。提示儿童血压与尿中ＴＸＢ２、ＰＧＩ２排出量有着重要关系。     

Influence of substrates on the in vitro kinetics of steviol glucuronidation and interaction between steviol glycosides metabolites and UGT2B7

Steviol glycosides, a natural sweetener, may perform bioactivities via steviol, their main metabolite in human digestion. The metabolising kinetics, i.e. glucuronidation kinetics and interaction between steviol glycosides or their metabolites and metabolising enzyme, are important for understanding the bioactivity and cytotoxicity. The present study investigated kinetics of steviol glucuronidation in human liver microsome and a recombinant human UDP-glucuronosyltransferases isomer, UGT2B7, along with molecular docking to analyse interaction between UGT2B7 and steviol or glucose. The active pocket of UGT2B7 is consisted of Arg352, Leu347, Lys343, Phe339, Tyr354, Lys355 and Leu353. The influence of stevioside, rebaudioside A, glucose and some chemotherapy reagents on the glucuronidation was also studied. The predicted hepatic clearence suggested that steviol could be classified as high-clearence drug. The steviol glycosides did not affect the glucuronidation of steviol notably.