氯化钇和氯化镨引起的人淋巴细胞DNA分子损伤的研究 A Study of DNA Damage in Human Lymphocytes Induced by Yttrium Chloride and Praseodymium Chloride

用单细胞凝胶电泳法检测了稀土化合物氯化钇和氯化镨对人外周血淋巴细胞的DNA损伤效应。结果表明,与对照相比,3种不同浓度的氯化钇和氯化镨均可引起淋巴细胞DNA受损后DNA迁移率的显著升高,受损伤细胞的百分率与对照差异明显,提示氯化钇和氯化镨具有一定的遗传毒性。 Abstract:The effect of DNA damage in human lymphocytes induced by yttrium chloride and praseodymium chloride was detected using SCG assay.The results showed that a highly significant increase in DNA migration in DNA-damaged lymphocytes was induced by three different concentrations of yttrium and praseodymium compared with the control,The percentage of DNA-damaged have genetic toxicity.The relevant points to this study are discussed.     

注意缺损多动障碍关联于DXS7位点

用单细胞凝胶电泳法检测了稀土化合物氯化钇和氯化镨对人外周血淋巴细胞的DNA损伤效应。结果表明,与对照相比,3种不同浓度的氯化钇和氯化镨均可引起淋巴细胞DNA受损后DNA迁移率的显著升高,受损伤细胞的百分率与对照差异明显,提示氯化钇和氯化镨具有一定的遗传毒性。 Abstract:The effect of DNA damage in human lymphocytes induced by yttrium chloride and praseodymium chloride was detected using SCG assay.The results showed that a highly significant increase in DNA migration in DNA-damaged lymphocytes was induced by three different concentrations of yttrium and praseodymium compared with the control,The percentage of DNA-damaged have genetic toxicity.The relevant points to this study are discussed.     

侧脑室和下丘脑外侧区微量注射氯化镨对大鼠迷走神经放电的影响

侧脑室和下丘脑外侧区微量注射氯化镨对大鼠迷走神经放电的影响罗基花曹晓杰１王绍１韩弟文２（吉林医学院生理学教研室，吉林１３２００１；１白求恩医科大学生理学教研室，２通化地区卫校）本室曾观察到侧脑室注射稀土元素氯化镧可明显增加血中胰岛素的含量，而且也有增...     

氯化饮水有机提取物对HepG2细胞的脂质过氧化作用

东湖、汉江、长江是武汉市主要水源 ,本文研究了该三种水源的氯化饮水有机提取物对人肝肿瘤细胞HepG2的脂质过氧化作用 (LPO) ,探讨氯化饮水有机提取物引起细胞损伤的机制。以HepG2细胞作为靶细胞 ,采用体外培养细胞染毒方法 ,测定染毒细胞的丙二醛 (MDA)和还原型谷胱甘肽 (GSH)含量。氯化饮水有机提取物染毒浓度相当于 0 16 7、1 6 7、16 7、16 7mL水样 /mL培养液 ,DMSO(7μL/mL)为溶剂对照 ,H2 O2 (10 0 μmol/L)为阳性对照。与溶剂对照相比 ,氯化饮水有机提取物可使HepG2细胞脂质过氧化主要终产物MDA含量明显增加 ,抗氧化主要物质GSH明显下降 ,两者变化呈负相关。东湖氯化饮水有机提取物引起的MDA增加和GSH下降的作用较汉江明显 ,长江氯化饮水有机提取物对HepG2细胞的MDA则无明显影响。结果表明氯化饮水有机提取物对体外培养的HepG2细胞具有明显的脂质过氧化作用。比较而言 ,三种水源中东湖的氯化饮水有机提取物脂质过氧化作用较强。     

氯化橡胶的应用及其生产技术研究

氯化橡胶以其优良的稳定性和抗腐蚀性在我国船舶业和交通系统的建设中得到了广泛应用,我国经济发展新形势下,我们应加大氯化橡胶的生产与应用技术的研究力度,提高氯化橡胶的产量与质量。论文针对氯化橡胶的应用范围以及生产技术进行了分析。     

氯化镧对雄性小鼠精子质量及睾丸酶活力的影响

探讨氯化镧对小鼠精子质量及睾丸细胞酶的影响。40只成年昆明种雄性小鼠随机分成对照组、低(25mg·kg-1)、中(50mg·kg-1)、高(100mg·kg-1)剂量组,腹腔注射1次/4d,饲养35d。测定睾丸和附睾脏器指数,检测并计算精子数量、活精率、活动率和畸形率以及睾丸碱性磷酸酶(AKP)、酸性磷酸酶(ACP)、乳酸脱氢酶(LDH)、一氧化氮合酶(NOS)活力。结果显示,高剂量氯化镧降低了小鼠睾丸AKP活力,抑制了精子数量和质量;中剂量氯化镧能促进NOS活力,使精子数量减少,对精子质量造成损伤。     

氯化镨在小鼠肝脏细胞中形成含镨致密体

本实验给小鼠4次注射氯化镨(总剂量为200mg/kg)后,光镜发现肝细胞呈嗜酸变性或空泡变性,肝细胞与枯否细胞中酸性磷性酶阳性的溶酶体增多。电镜观察到肝细胞出现程度不同的核变形、内质网扩张、糖原缺乏、溶酶体含较多高电子密度微粒。肝细胞与枯否细胞中均出现由高电子密度微粒聚集形成的致密体,应用X射线微区分析术可测到镨特征性能谱峰。     

氯化血红素的吡啶血色原光吸收测定

测定含铁的原卟啉类物质的常用方法主要有两种:一种是邻菲罗啉(O-phenanthroline)光度法,另一种是吡啶血色原光吸收测定法。前者是测定铁卟啉的铁含量,后者是先将含铁的原卟啉转变成吡啶血色原后测定还原性铁卟啉的量。这两种方法都是测定铁卟啉蛋白类物质的重要方法。我们在研究提取氯化血红素工艺时,采用吡啶血色原光吸收测定法测定样品中氯化血红素的含量。该法操作简便、快速,结果可靠,是一种很理想的测定方法。     

氯化胆碱浸种对烟草幼苗某些生理特性的影响

烟草种子经氯化胆碱(CC)溶液浸种后,萌发种子的呼吸速率和α-淀粉酶活性提高,烟苗茎高和根系伸长受抑制,但根系活力和单位长度内苗干重显著增加;幼苗叶片中可溶性糖、可溶性蛋白质和叶绿素含量提高;超氧化物歧化酶(SOD)、过氧化物酶(POD)和硝酸还原酶(NR)活性也随氯化胆碱浓度的增大而明显提高.     

氯化两面针碱的提取分离、全合成及药理活性的研究进展

两面针是我国民间常用的传统中药之一,从根部提取分离到的氯化两面针碱是两面针植物多种生物活性的主要有效成分。当前,直接从植物中提取分离有效成分的方法不仅回收率低、成本高,而且氯化两面针碱存在水溶性差和生物利用度低的问题,因此大多学者致力于改造其结构以提高活性和利用度,同时探索高效经济的全合成方法以满足研究和生产的需求。该文以国内外相关文献为基础,对氯化两面针碱的提取、分离纯化、结构化合物的全合成路线以及药理活性机制的研究进展做一综述,总结目前研究中存在的不足,并对今后的研究重点做出展望,旨在为今后深入研究两面针碱及衍生物活性改造、解析作用机制、开发基于此结构的创新药物分子等提供理论依据。     

氯化锂对KT-1/A3细胞增殖和凋亡的影响

目的：研究氯化锂(LiCl)在体外对KT—1／A3白血病细胞增殖及凋亡的影响。方法：采用液体培养实验,MTT实验,集落培养实验为指标观察LiCl对KT—1／A3细胞增殖的影响,采用DNA片段凝胶电泳及流式细胞检测为指标检测细胞凋亡。结果：①不同浓度的LiCl(5mM—25mM)对KT—1／A3细胞具有抑制增殖的作用,这种增殖抑制作用呈剂量依赖关系。②在LiCl(20mM)作用72h的DNA凝胶电泳谱可见DNA Ladder及流式细胞仪检测可见凋亡特有的AP峰,提示LiCl可诱导KT—1／A3细胞凋亡。绪论：LiCl能抑制KT—1／A3白血病细胞增殖和诱导凋亡。     

Age-related alterations in cell division and cell cycle kinetics in control and trimethyltin-treated lymphocytes of human individuals

Trimethyltin chloride induced age-related suppression of cell division and cell cycle kinetics in human peripheral blood lymphocytes cultured in RPMI 1640 culture medium supplemented with human AB serum, phytohemagglutinin and bromodeoxyuridine. A high frequency of M₁ (first metaphase) cells was seen in cultures treated with a high dose (C ₁ = 1.0 g per culture) and in lymphocytes from donors in the age range 40–70 years. The delay in cell division and cell cycle kinetics may indicate a longer duration in DNA synthesis induced by trimethyltin chloride in aged lymphocytes.     

Apoptotic volume decrease, pH acidification and chloride channel activation during apoptosis requires CD45 expression in HPB-ALL T cells

Mitochondrial-perturbating agents such as toxic coumponds induce apoptosis. We note that the loss of CD45 expression in the lymphoblastic leukemia cell line HPB-ALL (HPB45.0) leads to an inhibition of nuclear apoptosis. Our hypothesis is that the absence of CD45 disturbs protein function regulated by a proto-oncogene of the Src family playing a significant role in nuclear apoptosis. In this work we explore the importance of a chloride efflux on DNA fragmentation. The role of tyrosine kinase in the function and regulation of the chloride channels was determined. Our results showed a disturbance of ionic homeostasis in CD45 deficient lymphocytes (CD45-) in contrast to normal lymphocytes (CD45+). The phosphorylation levels of the chloride channels are considerably inhibited in CD45-, while the expression levels of these channels are similar in the two types of cells. A hypertonic medium inhibits DNA fragmentation in CD45+ while a hypotonic medium increases DNA fragmentation in CD45-. Thus CD45 plays a significant role in nuclear apoptosis by the regulation of the chloride channels responsible for ionic homeostasis of the cell essential for the DFF40 activation.     

氯化钠密度梯度离心法制备用于显微注射的外源DNA片段

DNA显微注射是生产转基因动物最可靠和最常使用的一种方法,外源DNA的纯度对显微注射的成功起着至关重要的作用。本文介绍用氯化钠密度梯度离心的方法制备用于显微注射的外源DNA片段。与传统的琼脂糖凝胶回收的方法相比较,用此方法制备的外源DNA片段对小鼠受精卵进行显微注射后,受卵体母鼠的胚胎存活率,以及子代小鼠的外源基因整合率均有明显的提高。这一方法可为进一步提高转基因动物的成功率,提供方法学上的参考。 Abstract:DNA microinjection is the most popular and reliable method of producing transgenic animals.The purity of foreign DNA plays an important role for the success of microinjection.In this study,we introduced the use of sodium chloride step gradients in fractionating foreign DNA fragment for microinjection.The data demonstrated that,compared with the conventional agarose gel extraction method,NaCl purification scheme of toreign DNA could improve the treated embryo survival and foreign DNA intergration rate markedly.     

Methacryloxylethyl Cetyl Ammonium Chloride Induces DNA Damage and Apoptosis in Human Dental Pulp Cells via Generation of Oxidative Stress

The polymerizable antibacterial monomer methacryloxylethyl cetyl ammonium chloride (DMAE-CB) has provided an effective strategy to combat dental caries. However, the application of such material raises the question about the biological safety and the question remains open. The mechanism of this toxic action, however, is not yet clearly understood. The present study aims at providing novel insight into the possible causal link between cellular oxidative stress and DNA damage, as well as apoptosis in human dental pulp cells exposed to DMAE-CB. The enhanced formation of reactive oxygen species and depletion of glutathione, as well as differential changes in activities of superoxide dismutase, glutathione peroxidase, and catalase in DMAE-CB-treated cells indicated oxidative stress. By using substances that can alter GSH synthesis, we found that GSH was the key component in the regulation of cell response towards oxidative stress induced by DMAE-CB. The increase in oxidative stress-sensitive 8-Oxo-2''-deoxyguanosine (8-OHdG) content, formation of γ-H₂AX and cell cycle G1 phase arrest indicated that DNA damage occurred as a result of the interaction between DNA base and ROS beyond the capacities of antioxidant mechanisms in cells exposed to DMAE-CB. Such oxidative DNA damage thus triggers the activation of ataxia telangiectasia-mutated (ATM) signaling, the intrinsic apoptotic pathway, and destruction of mitochondrial morphology and function.     

Protective effect of ascorbic acid in cells of people exposed to cobalt chloride

The workers contacting with cobalt chloride for 10 years and more have been receiving 50 mg ascorbic acid for 30 days. DNA repair was analysed after this procedure in lymphocytes cultivated in vitro according to following criteria: reactivation and induced mutagenesis of vaccinia virus as well as formation of DNA breaks and their resynthesis upon treatment with cobalt chloride and 4-nitro-quinoline-1-oxide.     

Chloride in smooth muscle

Interest in the functions of intracellular chloride expanded about twenty years ago but mostly this referred to tissues other than smooth muscle. On the other hand, accumulation of chloride above equilibrium seems to have been recognised more readily in smooth muscle.

Experimental data is used to show by calculation that the Donnan equilibrium cannot account for the chloride distribution in smooth muscle but it can in skeletal muscle. The evidence that chloride is normally above equilibrium in smooth muscle is discussed and comparisons are made with skeletal and cardiac muscle. The accent is on vascular smooth muscle and the mechanisms of accumulation and dissipation.

The three mechanisms by which chloride can be accumulated are described with some emphasis on calculating the driving forces, where this is possible. The mechanisms are chloride/bicarbonate exchange, (Na+K+Cl) cotransport and a novel entity, “pump III”, known only from own work. Their contributions to chloride accumulation vary and appear to be characteristic of individual smooth muscles. Thus, (Na+K+Cl) always drives chloride inwards, chloride/bicarbonate exchange is always present but does not always do it and “pump III” is not universal.

Three quite different biophysical approaches to assessing chloride permeability are considered and the calculations underlying them are worked out fully. Comparisons with other tissues are made to illustrate that low chloride permeability is a feature of smooth muscle.

Some of the functions of the high intracellular chloride concentrations are considered. This includes calculations to illustrate its depolarising influence on the membrane potential, a concept which, experience tells us, some people find confusing. The major topic is the role of chloride in the regulation of smooth muscle contractility. Whilst there is strong evidence that the opening of the calcium-dependent chloride channel leads to depolarisation, calcium entry and contraction in some smooth muscles, it appears that chloride serves a different function in others. Thus, although activation and inhibition of (Na+K+Cl) cotransport is associated with contraction and relaxation respectively, the converse association of inhibition and contraction has been seen. Nevertheless, inhibition of chloride/bicarbonate exchange and “pump III” and stimulation of (K+Cl) cotransport can all cause relaxation and this suggests that chloride is always involved in the contraction of smooth muscle.

The evidence that (Na+K+Cl) cotransport more active in experimental hypertension is discussed. This is a common but not universal observation. The information comes almost exclusively from work on cultured cells, usually from rat aorta. Nevertheless, work on smooth muscle freshly isolated from hypertensive rats confirms that (Na+K+Cl) cotransport is activated in hypertension but there are several other differences, of which the depolarisation of the membrane potential may be the most important.

Finally, a simple calculation is made which indicates as much as 40% of the energy put into the smooth muscle cell membrane by the sodium pump is necessary to drive (Na+K+Cl) cotransport. Notwithstanding the approximations in this calculation, this suggests that chloride accumulation is energetically expensive. Presumably, this is related to the apparently universal role of chloride in contraction.     

离子液体1-丁基-3-甲基咪唑氯代盐对溶菌酶结晶的影响

以亲水性离子液体1-丁基-3-甲基咪唑氯盐(BmimCl)为添加剂,研究离子液体对溶菌酶结晶的影响.分别考察了离子液体对溶菌酶晶体数量与尺寸、晶体形貌及蛋白质纯度的影响,并探讨了离子液体对结晶过程影响的作用机制.离子液体通过增大溶菌酶的溶解度和其自身低蒸气压两种途径,降低了溶菌酶在结晶过程中的过饱和度,更有利于晶体的成核和生长,得到更好的结果.如避免多晶态现象的发生,增大晶体的尺寸,降低溶菌酶样品纯度的要求.X-射线衍射分析表明,离子液体未改变晶体的晶型结构,但可提高晶体的衍射分辨率.     

Cumulus Cells Block Oocyte Meiotic Resumption via Gap Junctions in Cumulus Oocyte Complexes Subjected to DNA Double-Strand Breaks

During mammalian oocyte growth, genomic DNA may accumulate DNA double-strand breaks (DSBs) induced by factors such as reactive oxygen species. Recent evidence demonstrated that slight DSBs do not activate DNA damage checkpoint proteins in denuded oocytes. These oocytes, even with DNA DSBs, can resume meiosis and progress to metaphase of meiosis II. Meiotic resumption in oocytes is also controlled by the surrounding cumulus cells; accordingly, we analyzed whether cumulus-cell enclosed oocytes (CEOs) with DNA damage are able to resume meiosis. Compared with DNA-damaged denuded oocytes, we found that meiotic resumption rates of CEOs significantly decreased. To assess the mechanism by which cumulus cells block meiotic resumption in CEOs with DNA DSBs, we treated the cumulus oocyte complex with the gap junction inhibitor carbenoxolone and found that carbenoxolone can rescue the block in CEO meiosis induced by DNA DSBs. Since cumulus cell-synthesized cAMPs can pass through the gap junctions between oocyte and cumulus cell to block oocyte meiosis, we measured the expression levels of adenylate cyclase 1 (Adcy1) in cumulus cells, and G-protein coupled receptor 3 (Gpr3) and phosphodiesterase 3A (Pde3a) in oocytes, and found that the mRNA expression level of Adcy1 increased significantly in DNA-damaged cumulus cells. In conclusion, our results indicate that DNA DSBs promote cAMP synthesis in cumulus cells, and cumulus cAMPs can inhibit meiotic resumption of CEOs through gap junctions.