二氧化硫对人体血淋巴细胞的遗传毒理效应

本文对某硫酸厂接触二氧化硫（ＳＯ＿２）４０名工人的外周血淋巴细胞染色体畸变（ＣＡ）、姊妹染色单体互换（ＳＣＥ）、及微核（ＭＮ）进行了分析。结果表明，接触ＳＯ＿２的工人其ＣＡ、ＳＣＥ及ＭＮ均显著高于对照组。本文也分析了ＳＯ＿２在体内的代谢产物──亚硫酸氢钠对淋巴细胞的遗传毒理效应。结果指出，亚硫酸氢钠可诱发人血淋巴细胞ＣＡ，ＳＣＥ及ＭＮ，且有明确的剂量效应关系。这些研究证明，ＳＯ＿２确是人血淋巴细胞染色体断裂剂和基因毒性因子；ＳＯ＿２与癌症的关系值得进一步研究。     

亚硒酸盐对蚕豆根尖细胞的遗传损伤效应

采用蚕豆根尖微核实验和姊妹染色单体交换实验，研究亚硒酸盐的遗传损伤效应．结果表明：0．1～50．0μg／g的亚硒酸氢钠(NaHSeO3)处理12h可诱发蚕豆根尖细胞遗传损伤，导致根尖细胞有丝分裂指数下降，间期具有微核的细胞数显著增多，姐妹染色单体交换(SCE)频率明显增高；且根尖微核细胞率与处理浓度间具有正相关，分裂指数与处理浓度间呈负线性相关，分裂指数与微核率之间表现负相关．研究结果提示：硒能破坏生物的遗传稳定性，职业接触或饮食补硒时应避免其毒害作用．图1表4参17     

MDMA(3,4亚甲基二氧甲基苯丙胺)对小鼠睾丸细胞微核率及染色体畸变率的影响

通过连续20 d对雄性小鼠灌胃染毒3,4-亚甲基二氧基甲基苯丙胺(3,4-methylenedioxymethamphetamine,MDMA)后,探究MDMA对雄性小鼠睾丸组织细胞微核率及染色体畸变率的影响.将雄性小鼠随机分为MDMA低(5.0mg/kg)、中(10.0mg/kg)、高(20.0 mg/kg)三个染毒剂量组,采用生理盐水做阴性对照,每日染毒1次.于末次给药后第二天,取小鼠睾丸组织细胞,采用常规微核(micronucleus,MN)试验,检测小鼠睾丸细胞微核率的改变;同时采用染色体畸变试验(chromosomal aberration test)探究MDMA对小鼠睾丸细胞染色体畸变率的影响.微核试验结果表明MDMA中、低剂量组小鼠睾丸细胞微核率与阴性对照组比较差异无显著性(P0.05),而高剂量与低剂量组小鼠睾丸细胞微核率及阴性对照组比较,差异均有显著性(P0.01).染色体畸变试验结果中,MDM高、中剂量组染色体畸变率分别与阴性对照组比较差异有显著性(P0.05),剂量组之间染色体畸变率差异也有显著性(P0.05).结论通过微核试验与染色体畸变试验结果同时得出:在该实验剂量内MDMA高剂量组能诱导小鼠睾丸组织细胞微核率增加,高剂量组及中剂量组可以使小鼠睾丸细胞染色体畸变率增高,说明其对雄性小鼠睾丸遗传物质有一定的损伤效应.图4,表2,参10.     

农药乙蒜素和细菌溴腈对蚕豆根尖细胞的致畸效应

利用蚕豆根尖微核技术研究农药乙蒜素和细菌溴腈对蚕豆根尖细胞的遗传损伤,测定蚕豆根尖细胞的微核率、有丝分裂指数和染色体畸变率.结果表明:2种农药均能诱发较高频率的微核率、有丝分裂指数和染色体畸变率.在乙蒜素质量浓度为0.032～0.160 g·L-1范围内,微核率随浓度升高而升高,呈一定的剂量-效应关系(r=0.881 9,P≤0.01);而在细菌溴腈质量浓度为0.625～2.5 g·L-1范围内,微核率则呈先上升后下降的趋势.     

农药氰戊菊酯和三氟氯氰菊酯对蚕豆根尖细胞的遗传损伤

采用蚕豆根尖微核技术研究了农药氰戊菊酯、三氟氯氰菊酯对蚕豆根尖细胞的遗传损伤.测定了不同浓度氰戊菊酯、三氟氯氰菊酯(5×10-10～5×10-2g·L-1)诱导下的蚕豆根尖细胞微核率、有丝分裂指数和染色体畸变率.结果表明,氰戊菊酯、三氟氯氰菊酯均能诱发较高的微核率,在一定浓度范围内,微核率随两种农药处理浓度的升高而增加,但随着处理浓度的进一步升高微核率反而呈下降趋势;两种农药均可使蚕豆根尖细胞有丝分裂指数增大;并能诱导蚕豆根尖细胞产生较高频率、多种类型的染色体畸变.氰戊菊酯和三氟氯氰菊酯对蚕豆根尖细胞具有明显的遗传毒性.     

微核技术监测环境材料的筛选——12个不同品种蚕豆根尖对铅离子的微核效应

物理或化学诱变剂对有丝分裂状态下的根尖分生区细胞有诱导染色体畸变的作用,可能出现微核(MCN)。由于微核出现率与诱变因子强弱成正比,因此,可以用来监测和评价环境。本文通过12个不同品种的蚕豆对铅离子微核效应的比较,介绍材料筛选的方法,并结合实验对用微核出现率对水质分等以及水质污染指数等概念开展一些讨论。     

镉对小麦根尖细胞的遗传损伤效应

为了研究重金属镉对小麦是否产生细胞毒性和遗传毒性效应,采用不同浓度镉对小麦根尖处理24、48、72 h,统计有丝分裂指数、微核率及染色体畸变率.结果表明,1 μmol·L-1镉可提高小麦根尖细胞有丝分裂指数,但随镉处理浓度的提高和处理时间的延长,有丝分裂指数逐步下降;4个时期相比,镉对有丝分裂前期和中期的影响较小.微核率随着镉处理浓度的提高而增加,但浓度过高时,微核率随着镉处理时间的延长反而有所降低.此外,染色体畸变率也逐步上升,且随镉浓度的增加和处理时间的延长,其作用效果急剧加大,呈现明显的剂量-效应、时间-效应关系.说明镉可引起小麦根尖细胞有丝分裂抑制和染色体损伤,具有明显的遗传毒性.     

蚕豆根尖微核试验在辣子草化感作用研究中的应用

运用蚕豆(Vicia faba L.)根尖细胞微核试验,研究入侵植物辣子草(Galinsoga parviflora Cav.)水浸提液的化感效应,结果表明,辣子草水浸提液具有一定的遗传毒性.在辣子草水浸提液作用下,蚕豆根尖细胞有丝分裂各时相受到影响,有丝分裂指数下降,微核率升高,细胞中出现了微核、染色体断片、染色体桥、染色体滞留等多种染色体畸变,辣子草水浸提液对蚕豆根尖的影响存在显著的时间效应和浓度效应.蚕豆根尖微核技术能较好的反映辣子草化感作用潜力,在评估入侵植物的化感作用方面具有较大的应用价值.     

SO2衍生物对蚕豆根尖细胞不同分裂阶段的遗传损伤

研究SO2体内衍生物-亚硫酸钠和亚硫酸氢钠混合液[c(Na2SO3):c(NaHSO3)=3:1]对蚕豆根尖细胞不同分裂时期的遗传损伤效应；结果表明：SO2衍生物（c=0.17-15.0mmolL^-1)诱发蚕豆根尖细胞遗传损伤在细胞分裂的不同阶段有不同的表现形式。间期异常主要是微核和核芽，分裂期异常包括微核，染色体断片，粘连及滞后等，研究结果表明：SO2衍生物处理组蚕豆根尖中，间期微核细胞数，分裂期具有染色体断裂，粘连或滞后的细胞数均明显多于对照组，而且易于观察分析，可以作为环境监测指标。     

氚水对蚕豆根尖的诱变效应

通过蚕豆根尖细胞微核率的变化来研究氚水β射线的对蚕豆根尖的诱变效应,探索微核率作为测定氚水引起细胞损伤指标的可能性.将蚕豆根尖置于不同活度的氚水中培养24 h后,收获蚕豆根尖细胞得到与氚水作用后细胞微核率并将实验结果进行回归方程拟合,得到HTOβ射线的最佳回归方程是Y=0.90+4.64x,细胞微核剂量-效应关系符合线性拟合方程.得到相对60Coγ射线,氚水(HTO)β射线诱发微核的相对生物效应(Relative biological effectiveness RBE)值在0.57—1.43之间.在所研究的较低剂量范围0—2 Gy以内,HTOβ射线对生物体的作用更加明显;微核的产生主要是由于在低剂量情况下HTOβ射线在一个电离辐射径迹上使两个染色单体各产生一个损伤的效率更高.     

无机砷在植物和微生物体内的代谢机制研究进展

砷污染是全球的热点问题之一.土壤中的无机砷在植物中的积累可通过食物链传递,从而对人体健康构成严重威胁.了解微生物和植物对无机砷的代谢机制,对认识和控制土壤中砷的风险至关重要.近年来,微生物对无机砷的代谢机制研究已经比较深入,但是仍有一些问题亟待解决,如信号传导、抗砷基因筛选等.在植物对无机砷的摄取、还原机制等方面也取得了一定进展,但是植物体内砷的转运机制、排出机制等仍有待进一步研究.论文综述了微生物、植物体内无机砷的代谢过程中,砷摄取、转运、还原和排出机制的最新进展,并对今后的研究方向进行了展望.     

High soil and groundwater arsenic levels induce high body arsenic loads,health risk and potential anemia for inhabitants of northeastern Iran

Arsenic bioavailability in rock, soil and water resources is notoriously hazardous. Geogenic arsenic enters the body and adversely affects many biochemical processes in animals and humans, posing risk to public health. Chelpu is located in NE Iran, where realgar, orpiment and pyrite mineralization is the source of arsenic in the macroenvironment. Using cluster random sampling strategy eight rocks, 23 soils, 12 drinking water resources, 36 human urine and hair samples and 15 adult sheep urine and wool samples in several large-scale herds in the area were randomly taken for quantification of arsenic in rock/soil/water, wool/hair/urine. Arsenic levels in rock/soil/water and wool/hair/urine were measured using inductively coupled plasma spectroscopy and atomic absorption spectrophotometry, respectively. While arsenic levels in rocks, soils and water resources hazardously ranged 9.40–25,873.3 mg kg^?1, 7.10–1448.80 mg kg^?1 and 12–606 μg L^?1, respectively, arsenic concentrations in humans’ hair and urine and sheep’s wool and urine varied from 0.37–1.37 μg g^?1 and 9–271.4 μg L^?1 and 0.3–3.11 μg g^?1 and 29.1–1015 μg L^?1, respectively. Local sheep and human were widely sick and slightly anemic. Hematological examination of the inhabitants revealed that geogenic arsenic could harm blood cells, potentially resulting in many other hematoimmunological disorders including cancer. The findings warn widespread exposure of animals and human in this agroecologically and geopolitically important region (i.e., its proximity with Afghanistan, Pakistan and Turkmenistan) and give a clue on how arsenic could induce infectious and non-infectious diseases in highly exposed human/animals.     

Human carcinogenesis by arsenic

Arsenic is one of the few human carcinogens for which there is not yet a reliable animal cancer model. As such, the classification of arsenic as a carcinogen is based upon data derived from human epidemiologic studies. Although the mechanisms of action of arsenic as a toxic agent have been known for many years, the inability to produce cancer with arsenic in laboratory animals has confounded the operational characterisation of arsenic as initiator, promoter, complete carcinogen, or cocarcinogen for humans. Arsenic is clearly a genotoxic agent that induces chromosomal aberrations, micronuclei and sister chromatid exchange in mammalian cells as well as neoplastically transforms Syrian hamster embryo cells; however, it is not a classical point mutagen. This paper reviews some of the scientifically based issues relating to arsenic and risk assessment.     

Metabolism and disposition of inorganic arsenic in laboratory animals and humans

The carcinogenicity of inorganic arsenic in humans, particularly in the lung and skin, has been reasonably well established through epidemiological investigations. However, there is no substantial experimental evidence for carcinogenicity in animals to support the human studies. Studies of metabolism and disposition of inorganic arsenic in various animal species are particularly relevant to determining the factors that might account for the lack of an animal model. Numerous studies of this type have been reported, but there do not appear to be clear qualitative or quantitative differences in the overall fate and disposition of inorganic arsenic in most animalsversus humans, although little is known at the cellular and subcellular level.Sulphur chemistry, especially thiol status, is emerging as an important regulating factor in the overall fate and distribution of inorganic arsenic in the body, playing a role in the initial reduction of arsenate to arsenite and subsequent methylation, and possibly in determining tissue affinity and distribution properties. The metabolism of inorganic arsenic can be viewed as a redox cycle in which thiol compounds such as glutathione (GSH) possibly function as reducing agents and methyl donors as oxidising agents. One explanation for the possible sensitivity of certain malnourished human populations to the carcinogenic effects of inorganic arsenic may be related to the reduced availability of nonprotein sulphhydryl compounds such as GSH needed to drive the redox cycle and facilitate arsenic detoxification. Future carcinogenicity studies of inorganic arsenic in animals could be designed to address directly this aspect of the problem.Disclaimer: Although the research described in this article has been supported by the United States Environmental Protection Agency, it has not been subjected to Agency review and therefore does not necessarily reflect the views of the Agency and no official endorsement should be inferred. Mention of trade names or commercial products does not constitute endorsement or recommendalion for use.     

化学农药与环境激素

环境激素是指有可能干扰人与脊椎动物内分泌的外因性化学物质。在已知的６７ 种（或类）环境激素有机物中,化学农药（包括除草剂、杀虫剂、杀菌剂）及其代谢产物共占４４ 种,几近三分之二。在已进行环境调查的４７ 种环境激素中,已检出的有２４ 种,占二分之一。列举了环境激素对人类和动物生育、生理功能的影响,并指出研制开发“安全化学农药”的思路是不可取的。     

多氯联苯羟基化代谢物及其雌激素效应研究进展

多氯联苯作为一种环境内分泌干扰物,具有一定的雌激素干扰效应,导致动物雌激素水平紊乱或功能异常,从而影响生殖、发育或行为。羟基多氯联苯是多氯联苯最主要的活性代谢产物,已经在动物和人体组织中被检出。羟基多氯联苯的化学性质和分子空间构象使其雌激素干扰效应可能较母体化合物更强。因此,它们对人类和动物机体的潜在影响以及由此带来的新的毒理学问题成为内分泌干扰研究领域的热点之一,相关的毒性作用机制需要进一步探索。本文对多氯联苯的代谢途径、羟基多氯联苯在生物体内的暴露水平、雌激素干扰效应及作用机制进行综述。     

吸附法处理含砷废水的研究进展

水体砷污染严重威胁着人类健康和生态系统,砷污染防治成为全球性环境问题,含砷水处理受到人们的普遍关注.与其它除砷方法相比较,吸附法具有去除效率高,稳定性好,不产生或很少产生二次污染,吸附剂可重复使用等优点,因而备受青睐.本文简要介绍了吸附法除砷的原理与特点,重点综述了矿物质、活性炭、金属(氢)氧化物、生物吸附剂、离子交换...     

Recent advances in arsenic mutagenesis and carcinogenesis†

Arsenic is ubiquitously distributed in nature and is released into the environment through non‐ferrous smelting operations, generation of power from coal, and agriculture.

Epidemiological studies have shown that the incidences of epidermoid carcinomas of the skin and lungs, and of pre‐cancerous dermal keratoses are significantly increased in human subjects exposed to arsenic compounds by oral or respiratory routes. The negative results obtained on animals treated with arsenicals suggest strongly that this metal is probably a cocarcinogen.

The results of the short‐term tests suggest that the cocarcinogenic properties of arsenic could be related to its ability to inhibit DNA repair.     

Recognizing animal personhood in compassionate conservation

Compassionate conservation is based on the ethical position that actions taken to protect biodiversity should be guided by compassion for all sentient beings. Critics argue that there are 3 core reasons harming animals is acceptable in conservation programs: the primary purpose of conservation is biodiversity protection; conservation is already compassionate to animals; and conservation should prioritize compassion to humans. We used argument analysis to clarify the values and logics underlying the debate around compassionate conservation. We found that objections to compassionate conservation are expressions of human exceptionalism, the view that humans are of a categorically separate and higher moral status than all other species. In contrast, compassionate conservationists believe that conservation should expand its moral community by recognizing all sentient beings as persons. Personhood, in an ethical sense, implies the individual is owed respect and should not be treated merely as a means to other ends. On scientific and ethical grounds, there are good reasons to extend personhood to sentient animals, particularly in conservation. The moral exclusion or subordination of members of other species legitimates the ongoing manipulation and exploitation of the living worlds, the very reason conservation was needed in the first place. Embracing compassion can help dismantle human exceptionalism, recognize nonhuman personhood, and navigate a more expansive moral space.     

Effect of alloxan induced diabetes on liver and kidney function in arsenic treated rats

Experiments were performed to study the effects of inorganic arsenic (iAs) on liver and kidney functions of diabetic rats. Data showed that arsenic concentration decreases in the liver and kidneys of rats in hyperglycemic conditions. Alanine aminotransferase (ALT) activity was markedly less in arsenic-diabetic rats compared to arsenic alone; however, hyperbilirubinemia was observed in arsenic-diabetic animals. Creatinine values showed improved kidney function in arsenic-diabetic rats compared to arsenic alone. Histopathological observations were less severe in inorganic arsenic liver and kidneys of alloxan-diabetic rats. These observations were considered to be important since they partially argue against earlier reports that demonstrated a diabetogenic effect attributed to arsenic.