镉胁迫下大豆中镉的分布状况及其籽粒品质

溶液培养中0.5μmol·L-1镉胁迫浓度下,大豆表现出轻微受害症状,籽粒减产25 . 7%,而籽粒中粗脂肪和粗蛋白含量变化不大.镉在大豆中的积累分布状况为根>叶>籽>油,比例为32.100:1.690:1.000:0.003.大豆籽粒含镉4.89mg/kg,超过了国家环境标准规定的最高容许量.而大豆粗脂肪中含镉仅0.015mg/kg,远低于国家食品环境卫生标准.豆粕中含镉6.17mg/kg,表明大豆籽粒中的镉主要存在于粗蛋白和淀粉中.     

Radiation hormesis — fact or fiction?

Deriving from the Greek verbhormein, which means to stimulate and excite, hormesis literally refers to any kind of stimulation and excitation. As a medical and geomedical term (though of unsettled status) it has a more restricted meaning however, indicating merely the putative or real stimulatory and beneficial effects observed when a biological system is exposed to a low dose of an agent known to be toxic or hazardous at a significantly larger dose. Depending on the type of stimulatory agent, one can speak of chemical or physical hormesis, radiation hormesis being a member of the latter group. The present paper reviews and evaluates the history and origins of the concept of radiation hormesis and its present status — fact or fiction. It is concluded that despite the numerous, sometimes undeniably strong, individual pieces of evidence that have been presented in favour of this phenomenon, the bulk of the evidence is so far not strong enough to establish it as a scientifically proven fact. It is also evident that, instead of speaking of radiation hormesis as an entity, one should pay attention separately to the effects of alpha, beta and gamma radiation, the deleterious and possible beneficial hormetic effects being different in each case.     

Insect cell-based impedance biosensors: a novel technique to monitor the toxicity of environmental pollutants

Cell biosensors are currently emerging as novel, sensitive techniques to monitor the toxicity of environmental pollutants. Here, we have developed electric cell-substrate impedance sensing (ECIS) for on-line monitoring of the behavior of insect cells. Cells were cultured on a microarray of eight small gold electrodes, deposited on the bottom of tissue culture wells. Upon inoculation, cells showed a tendency to drift downward and attached to the gold surface precoated with the protein Concanavalin A to accelerate the cell attachment. The impedance increased because the cells acted as insulating particles to restrict the current flow. The resulting impedance, a coordination of many biological reactions within the cell, was continuously monitored in real-time to reveal information about cell spreading and micromotion. As the cell behavior was sensitive to external chemicals, the applicability of ECIS for inhibition assays was demonstrated with HgCl₂, 2,4,6-trinitrotoluene (TNT), 2-amino 4,6-dinitrotoluene (2-ADNT) and 1,3,5-trinitrobenzene (TNB). Electronic Publication     

松胞素B对人血淋巴细胞和CHL细胞微核率的影响

研究了不同浓度的松胞素Ｂ对人血淋巴细胞和中国仓鼠肺成纤维细胞（ＣＨＬ）分裂吉周期和微核率的影响。结果表明,松胞素Ｂ浓度增高过高能引起细胞微核率增高。在本研究中,对ＣＨＬ细胞微核率试验以３μｇ／ｍＬ松胞素Ｂ较适合;而对人血淋巴细胞微核试验,松胞素Ｂ浓度以２－４μｇ／ｍＬ为宜,松胞表Ｂ浓度过高会提高微核背景值,降低试验的灵敏度和精确性。     

13种樟科植物叶油细胞和粘液细胞的分布和结构的比较研究

利用组织透明法、石蜡制片法和薄切片法比较研究了樟科５属１３种植物叶片中油细胞和粘液细胞的分布和结构．结果表明：５属１１种植物叶片中有油细胞分布,其形状多为圆形,体积较小且大小基本一致,ｄ３０～４５μｍ;４属８种植物叶片中有粘液细胞分布,其形状多为椭圆形,体积较大,ｄ６０～１００μｍ．根据透明叶片观察,不同植物油细胞的分布密度不同;从叶片横切面观察,有些种油细胞分布于整个叶肉中,有的分布于栅栏组织与海绵组织之间及海绵组织中,有的仅分布于栅栏组织内．粘液细胞有些种分布于整个叶肉,而有的仅分布于栅栏组织中．因此,叶片内油细胞的分布密度、油细胞和粘液细胞的分布位置及其大小在种与种之间存在明显的差异,此种结构特征具有分类学上的意义     

东亚钳蝎抑制型神经毒素基因在昆虫细胞中的表达及活性鉴定

基因BmKIT3R 是根据东亚钳蝎 (ButhusmartensiiKarsch)抑制型神经毒素基因BmKIT3 优化而得的 .将优化过的蝎毒素基因BmKIT3R 通过Bac to Bac操作技术 ,使重组杆状病毒基因组DNA转染到草地粘虫sf2 1细胞中对IT3R 基因进行表达 ,经SDS PAGE检测在 8.7× 10 3 处有一表达条带 .表达产物经生物鉴定 ,证明具有很高的活性 ,它对昆虫具有非常明显的致死作用 .图 3参 5     

南宁城市大气污染对人体健康的危害及治理对策

南宁市大气属煤烟型污染 ,大气的主要污染物为SO2 、NOx、TSP、降尘 ,虽然随着环境管理和污染治理工作的加强 ,污染物浓度逐年下降 ,但是工业区大气污染仍然较重。污染物流行病学调查显示 :工业区癌症和呼吸系统疾病死亡率均高于全市平均水平 2倍左右 ,城区又高于郊区 2倍 ,大气污染综合指数与呼吸内科门诊就诊人数呈正相关。用邓聚龙的灰色系统理论分析得知污染物对癌症和呼吸系统疾病死亡率有关联 ,关联度从大到小排序为 :TSP >降尘 >SO2 >NOx ,最后提出了大气污染治理的对策。     

婴儿奶嘴提取液对大鼠肝原代细胞和HepG2细胞的毒性作用（Cytotoxicity of Extraction Liquids of Nipples on Primary Cultured Rat Hepatocytes and HepG2 Cells）

乳胶制品,如医用手套、婴儿奶嘴、避孕套等,存在着N-亚硝胺及亚硝基物质析出现象.对于乳胶制品中析出的N-亚硝胺及亚硝基物质,我国尚无法规加以限制,对其使用的安全性进行科学的分析更是鲜有报道.论文使用人工唾液盐溶液浸泡婴儿奶嘴,将提取液与体外培养的SD大鼠肝原代细胞、HepG2细胞作用一定时间,通过MTT实验和单细胞凝胶电泳实验,检测了婴儿奶嘴提取液对细胞存活率的影响和对DNA的损伤作用.结果显示:排除唾液盐溶液对细胞存活率的影响,婴儿奶嘴提取液与肝原代细胞和HepG2细胞作用24、48、72h,细胞存活率分别降至(85.22±13.77)%、(60.40±20.51)%、(79.28±20.08)%;(71.23±18.22)%、(69.51±16.96)%、(70.25±16.57)%,与阴性对照组(10%DEME)相比均有显著性差异(p<0.01).奶嘴提取液与肝原代细胞和HepG2细胞作用24h,尾长、Olive尾矩、尾DNA%、头尾比分别为(24.86±18.88)μm、6.60±5.99、(52.23±16.90)%、0.86±0.57;(17.48±10.87)μm、9.39±3.23、(57.94±20.94)%、0.83±0.67,显著高于阴性对照组和唾液盐溶液组(p<0.01).研究结果表明婴儿奶嘴提取液能够降低肝原代细胞和HepG2细胞存活率,且对DNA具有损伤作用.     

四溴二苯醚对人甲状腺细胞功能的影响

为研究四溴二苯醚(BDE-47)对原代培养人甲状腺细胞功能的影响,分别用浓度为10-12、10-10和10-8mol·L-1的BDE-47处理原代人甲状腺滤泡上皮细胞(TEC)24h,采用化学发光酶联免疫检测法检测细胞上清液中甲状腺球蛋白(Tg)的浓度,半定量逆转录聚合酶链反应技术检测功能相关的Tg基因和双链复合蛋白8(Pax-8)基因的表达.结果表明,10-12、10-10mol·L-1暴露组Tg分泌量较对照组显著减少(p<0.05),而10-8mol·L-1BDE-47组Tg分泌量与对照组无显著性差异(p>0.05).甲状腺功能相关Tg基因和Pax-8基因的表达量随BDE-47浓度的增加而显著降低(p<0.05),呈明显的剂量-效应关系.以上结果提示,BDE-47对离体培养的原代人甲状腺细胞的功能具有抑制作用,甲状腺功能相关Tg基因和Pax-8基因的表达下调可能是其作用机制之一.     

铅暴露U251细胞差异表达基因及相关通路(The Interrelated Pathways in Brain Human U251 Glioma Cells by Lead Exposure)

为探讨铅对体外培养的人神经胶质瘤U251细胞(human U251glioma cells,U251)暴露后基因表达的变化以及相关基因通路,选用乙酸铅暴露U251细胞.细胞在乙酸铅中暴露8h和24h后提取RNA,使用cDNA芯片分析基因表达情况,芯片扫描结果经归一化处理,设定Ratio值<0.5或≥2.0为表达有差异基因.结果表明,铅暴露U251细胞导致2840条基因差异表达,使用KEGG和BioCarta数据库分析代表性基因网络.结果发现,铅暴露U251细胞导致大量基因差异表达,涉及多个代谢及信号通路,与神经组织相关的主要信号通路有Ca2+信号通路、Jak-STAT信号通路、MAPK信号通路、Wnt信号通路等,还涉及配体-受体、细胞因子相互作用等.这些通路相互联结,构成复杂的网络系统,调控细胞的生物学功能.