Assessment of Oxidative DNA Damage by Alkaline Comet Assay in Human Essential Hypertension

The objective of the present study was to investigate the antioxidant status and the extent of oxidative DNA damage in lymphocytes and their relation with essential hypertension (EHT). A total of 100 South Indian subjects aged 30–65 were included for the study. Of these 50 were normotensive controls (group-1) with blood pressure ≥120/80 mm Hg, 50 were newly diagnosed (group-2) and were not on any antihypertensive drugs, but had systolic blood pressure ranging between 140 and 160 mmHg and diastolic blood pressure 95–100 mmHg and 50 newly diagnosed essential hypertensive patients underwent drug therapy for 1 year was considered as group-3. Enzymatic and non-enzymatic antioxidants significantly decreased and lymphocyte DNA damage was significantly increased in newly diagnosed hypertensive patients compared with control group. The major decrease in DNA damage and significant improvement in enzymatic and non-enzymatic antioxidants were observed after 1 year of antihypertensive therapy in treated group compared with newly diagnosed hypertensive patients. Total antioxidant status and lymphocyte DNA damage showed a strong negative correlation in all the three groups. Essential hypertension associated with oxidative stress which in turn causes genotoxic susceptibility to variety of disease including cancer. In the absence of DNA repair process and DNA checkpoint mechanisms, the genomic integrity is susceptible to extensive damage. In our study, increased oxidative DNA damage and decreased antioxidant levels were frequently observed in the newly diagnosed essential hypertensive patients, suggesting that oxidative stress is important in the pathogenesis of EHT. Therefore, the present study has additional clinical implication. Further investigations with large number of patients along with antioxidant supplement are highly warranted.     

Changes in antioxidant enzyme levels and DNA damage during aging

Multiple mechanisms underlie the human aging process, but interest continues in the role that free radicals and antioxidants may play. The concentrations of lymphocyte free radical generation (O₂ ⁻& H₂O₂), DNA damage and antioxidant enzyme levels (glutathione Stransferase, superoxide dismutase and catalase) were evaluated in 110 healthy individuals with an age range of 20–80 years. The antioxidant enzyme levels were significantly less in very old age when compared to young. Moreover, the levels of free radical concentration and DNA damage were increased in the same age group with respect to younger group. Cigarette smoking had a positive relation with free radicals and DNA damage, and inverse relation with antioxidants. On the other hand, body mass was found to have positive relation with free radical generation only. The data indicate that depletion of antioxidant enzyme levels would render the older people more susceptible to free radical stress and DNA damage.     

Evaluation of Oxidative Stress and DNA Damage in Benign Prostatic Hyperplasia Patients and Comparison with Controls

In the present study, oxidative stress and lymphocytic DNA damage in both pre-op and post-op benign prostrate hyperplasia (BPH) patients with age >50 years was evaluated and compared with normal healthy subjects (controls- without any evidence of disease) of the same sex and age group. From December 2007 to November 2009, oxidative stress in 45 BPH patients were evaluated both before (pre-op patients) and after 7 days of surgery (post-op patients) in terms of measurements of plasma levels of (1) various anti-oxidative enzymes, (2) non-enzymatic antioxidants and (3) malondialdehyde which is a product of lipid peroxidation. The lymphocyte DNA damage was also evaluated by single cell alkaline gel electrophoresis in terms of tail length migration in these patients. These values were compared with their respective control subjects of similar sex and age group. The activities of antioxidant enzymes and the levels of antioxidant, reduced glutathione were found significantly decreased (p < 0.05) in serum samples of pre-operative group of BPH patients as compared to the controls. These altered parameters increased significantly (p < 0.05) and returned to their near normal control values, but not up to baseline values, in post operative patients i.e. after the cancer load was decreased by surgery. Lymphocytic DNA damage was found to be significantly increased in pre-op group as compared to controls and was reduced after surgery in post-op group. The present study therefore, shows significantly increased levels of oxidative stress and DNA damage in BPH patients which were reduced after removal of tumour load. Thus oxidative damage plays an important role in prostate tumourogenesis and timely management of oxidative stress can be of importance in preventing the occurrence of BPH.     

基于云计算的生物DNA指纹图谱大范围比对方法

针对DNA特征比对过程中,产生的生物DNA特征图谱特征较为复杂,生物特征极为琐碎,海量生物DNA特征的对比,依然是一项十分复杂的工作。传统算法多是基于单个DAN特征进行车轮式对比。一旦生物特征过于繁琐,造成比对匹配耗时,效率较低。本文提出了一种基于云计算的生物DNA特征海量数据对比技术。建立云计算网络模型,计算生物DNA泳道特征系数,将DNA限制性片断形成的谱带从背景中分离出来,完成海量DNA数据对比。实验证明,这种算法能够避免由于DNA图谱数量过大造成的匹配耗时缺点,提高了生物DNA指纹图谱大范围比对的效率。     

Oral Nicotine Induces Oxidative Stress and Inflammation but Does Not Subvert Tumor Suppressor and DNA Repair Responses in Mice

Nicotine, responsible for the addictive properties of tobacco, is widely used in nicotine replacement therapy for tobacco use cessation. We investigated the time-dependent effect of treatment with nicotine on the tumor suppressor, DNA repair and immune responses. Swiss Albino mice (laca strain) of both sexes received nicotine dissolved at a dose of 100 µg/ml in 2% sucrose for 24 weeks, by oral gavage, while age- and gender-matched controls received only 2% sucrose for the same period. Nicotine-treated and control mice were sacrificed 6, 16 and 24 weeks post-treatment, and their tissues evaluated for alterations in histology, oxidative stress, TNF-α levels, nitric oxide (NO) and myeloperoxidase (MPO) release, tumor suppressor response and DNA repair response. Statistical significance of results was determined using Students’ t test. The tissues of nicotine treated mice exhibited a large number of multinucleated and binucleated cells, enlarged nuclei and non-uniform distribution of cells, significant increase in expression of TNF-α gene and serum TNF-α, and time-dependent significant increase in lipid peroxidation, protein carbonylation, NO and MPO release when compared to age-and gender-matched controls. The mRNA expression of the tumor suppressor gene p53, its primary regulator Mdm2, and the DNA repair genes Brca2 and Ape1 were significantly elevated, but the corresponding protein levels remained largely unaltered. In conclusion, treatment with nicotine caused oxidative stress and inflammation which can cause widespread cellular damage from the very onset of treatment, without subverting the tumor suppressor and DNA repair responses.Electronic supplementary materialThe online version of this article (10.1007/s12291-020-00903-8) contains supplementary material, which is available to authorized users.     

An integrated microfluidic array system for evaluating toxicity and teratogenicity of drugs on embryonic zebrafish developmental dynamics

Seeking potential toxic and side effects for clinically available drugs is considerably beneficial in pharmaceutical safety evaluation. In this article, the authors developed an integrated microfluidic array system for phenotype-based evaluation of toxic and teratogenic potentials of clinical drugs by using zebrafish (Danio rerio) embryos as organism models. The microfluidic chip consists of a concentration gradient generator from upstream and an array of open embryonic culture structures by offering continuous stimulation in gradients and providing guiding, cultivation and exposure to the embryos, respectively. The open culture reservoirs are amenable to long-term embryonic culturing. Gradient test substances were delivered in a continuous or a developmental stage-specific manner, to induce embryos to generate dynamic developmental toxicity and teratogenicity. Developmental toxicity of doxorubicin on zebrafish eggs were quantitatively assessed via heart rate, and teratological effects were characterized by pericardial impairment, tail fin, notochord, and SV-BA distance ∕body length. By scoring the teratogenic severity, we precisely evaluated the time- and dose-dependent damage on the chemical-exposed embryos. The simple and easily operated method presented herein demonstrates that zebrafish embryo-based pharmaceutic assessment could be performed using microfluidic systems and holds a great potential in high-throughput screening for new compounds at single animal resolution.     

解析我国区域协调发展的制约因素 探究全国主体功能区规划的重要作用

从区域协调发展的制约因素入手,解析了传统区域发展模式的弊端和对空间结构效益认识的偏差,讨论了能否以缩小区域经济发展水平差距作为区域发展战略目标的困惑,分析了四大板块(西部、东北、中部和东部)战略的政策缺陷及原因,探究了以空间布局规划体系不完整为主要问题的体制机制问题。在此基础上,阐述了我国开展主体功能区规划的作用。主体功能区规划是突出以人为本、注重人与自然协调的国土空间开发布局总图,是政府实施空间管治的纲领性文件和整合相关空间规划资源的实用平台,是正确发挥政府和市场的调节作用、促进区域协调发展的科学依据,也是引导全社会正确认识和合理建设我们生存空间的行动指南。     

Elegant hypothesis and inelegant fact in developmental biology

The relationship between theoretical and experimental approaches to the problem of pattern generation during embryonic development has often been uneasy. This stems at least in part from the different emphases that have typically been used in the two approaches. The spectacular success of modern genetic techniques in uncovering developmental mechanisms has led to a widespread belief that theory is no longer very relevant. However, recent examples of data-driven modelling point to new roles for theoretical approaches in exploring important issues such as the robustness and evolution of pattern-forming mechanisms.     

金属DNA纳米线的制作方法

DNA分子的独特的双螺旋结构,使得DNA具有热力学上的稳定性、线性的分子结构及机械性等特征,是作为制备金属纳米线的理想模板。通过以DNA为模板形成金属纳米线,提高了DNA导电性,使得DNA分子作为纳米导线构筑纳米器件成为可能,在构筑生物纳米器件的领域会有广阔的应用前景。     

人胚胎干细胞发明的可专利性探讨

生物技术的迅速发展给专利法律制度带来新的挑战,人胚胎干细胞研究有巨大的治疗价值,但对其研究成果能否获得专利保护存在伦理道德和公共利益方面的争议。目前世界上不同国家和地区对人胚胎干细胞研究采取了不同的法律政策,就我国而言,采取严格排除专利授予原则,不利于科学研究的发展和社会公共健康利益,因而应适当放宽人胚胎干细胞相关发明的专利授予条件。     

春小麦外源DNA两次导入和导入后杂交及其后代醇溶蛋白电泳分析

本文采用A－PAGE方法,对外源DNA导入两次的四个后代变异系、一个后代变异株系的六个单株和导入后代间杂交的四个后代变异系进行了醇溶蛋白电泳分析。结果表明：1．外源DNA两次导入进一步强化了变异;2．A－PAGE方法不仅可用于验证外源DNA导入的变异后代,而且可检测后代变异系的遗传稳定性;3．使外源DNA导入后的变异后代间再进行杂交,能够丰富变异类型。而且导入技术与杂交方法的结合,可以互相补充,对作物育种具有重要意义。     

Molecular Studies on Coronary Artery Disease—A Review

Coronary artery disease (CAD) remains the major cause of mortality and morbidity in the entire world population. The conventional risk factors of CAD include hypertension, hyperlipidemia, diabetes mellitus, family history, smoking etc. These factors contribute only 50 % of the total risk of CAD. For providing a complete risk assessment in CAD, it is mandatory to have well-planned clinical, biochemical and genetic studies in patients with CAD and subjects who are at risk of developing CAD. In this review an attempt is made to critically evaluate the conventional and emerging risk factors which predispose the individual to CAD. Specifically, the molecular basis of CAD including high oxidative stress, low antioxidant status and increased DNA damage are covered. A comprehensive and multifactorial approach to the problem is the better way to reduce the morbidity and mortality of the disease.     

Radiolytic studies of cefozopran hydrochloride in the solid state

BackgroundThe radiation sterilization is one of the best methods for sterilizing vulnerable degradation drugs like cefozopran hydrochloride.ResultsChemical stability of radiosterylized cefozopran hydrochloride, was confirmed by spectrophotometric and chromatographic methods. EPR studies showed that radiation has created some radical defects whose concentration was no more than several dozen ppm. The antibacterial activity of cefozopran hydrochloride irradiated with a dose of 25 kGy was unaltered for Gram-positive bacteria but changed for two Gram-negative strains. The radiation sterilized cefozopran hydrochloride was not in vitro cytotoxic against human CCD39Lu normal lung fibroblast cell line.ConclusionsCefozopran hydrochloride in solid state is not resistant to radiation sterilization and this method cannot be used for sterilization of this compound.     

Metabolic profile analysis of a single developing zebrafish embryo via monitoring of oxygen consumption rates within a microfluidic device

A combination of a microfluidic device with a light modulation system was developed to detect the oxygen consumption rate (OCR) of a single developing zebrafish embryo via phase-based phosphorescence lifetime detection. The microfluidic device combines two components: an array of glass microwells containing Pt(II) octaethylporphyrin as an oxygen-sensitive luminescent layer and a microfluidic module with pneumatically actuated glass lids above the microwells to controllably seal the microwells of interest. The total basal respiration (OCR, in pmol O₂/min/embryo) of a single developing zebrafish embryo inside a sealed microwell has been successfully measured from the blastula stage (3 h post-fertilization, 3 hpf) through the hatching stage (48 hpf). The total basal respiration increased in a linear and reproducible fashion with embryonic age. Sequentially adding pharmacological inhibitors of bioenergetic pathways allows us to perform respiratory measurements of a single zebrafish embryo at key developmental stages and thus monitor changes in mitochondrial function in vivo that are coordinated with embryonic development. We have successfully measured the metabolic profiles of a single developing zebrafish embryo from 3 hpf to 48 hpf inside a microfluidic device. The total basal respiration is partitioned into the non-mitochondrial respiration, mitochondrial respiration, respiration due to adenosine triphosphate (ATP) turnover, and respiration due to proton leak. The changes in these respirations are correlated with zebrafish embryonic development stages. Our proposed platform provides the potential for studying bioenergetic metabolism in a developing organism and for a wide range of biomedical applications that relate mitochondrial physiology and disease.     

Bio-electrospraying of human mesenchymal stem cells: An alternative for tissue engineering

Bio-electrospraying (BES) is a technique used for the processing of cells and can be applied to tissue engineering. The association of BES with scaffold production techniques has been shown to be an interesting strategy for the production of biomaterials with cells homogeneously distributed in the entire structure. Various studies have evaluated the effects of BES on different cell types. However, until the present moment, no studies have evaluated the impact of BES time on mesenchymal stem cells (MSC). Therefore, the aim of this work was to standardise the different parameters of BES (voltage, flow rate, and distance of the needle from the collecting plate) in relation to cell viability and then to evaluate the impact of BES time in relation to viability, proliferation, DNA damage, maintenance of plasticity and the immunophenotypic profile of MSC. Using 15 kV voltage, 0.46 ml/h flow rate and 4 cm distance, it was possible to form a stable and continuous jet of BES without causing a significant reduction in cell viability. Time periods between 15 and 60 min of BES did not cause alterations of viability, proliferation, plasticity, and immunophenotypic profile of the MSC. Time periods above 30 min of BES resulted in DNA damage; however, the DNA was able to repair itself within five hours. These results indicate that bio-electrospraying is an adequate technique for processing MSC which can be safely applied to tissue engineering and regenerative medicine.     

Oxidatively Damaged DNA: A Possible Antigenic Stimulus for Cancer Autoantibodies

Reactive oxygen species (ROS) are cytotoxic at higher concentration resulting in cell death, mutations, chromosomal aberrations or carcinogenesis. In this study DNA was modified by singlet oxygen and superoxide anion radicals generated by illumination of riboflavin under 365 nm UV-light. The modified DNA induced high titre antibodies in experimental animals. In enzyme immunoassay, serum antibodies from cancer patients (n = 34) showed a higher recognition of the modified DNA, as compared to the native form. This was further confirmed by the gel-shift assay. Immune IgG were used as a probe to detect oxidative lesions in the DNA of cancer patients. DNA isolated from lymphocytes of cancer patients proved to be an appreciable inhibitor of the experimentally induced antibodies against the ROS-DNA. This indicates the presence of oxidative lesions in the DNA obtained from cancer patients. The results show that ROS induced oxidative damage to DNA in cancer patients generate neo-epitopes that are alien for the immune system, resulting in autoantibody formation.     

空间优化视阈下的灾区主体功能区建设

通过对灾区自然经济特征的分析,结合灾害损毁程度,从空间结构优化的角度对灾区重建进行研究,认为灾后重建的空间优化途径主要是主体功能区建设,并对灾区的主体功能区划进行思考,认为应针对灾区中不同类型的功能区进行建设:灾区中的平原地区在推进恢复同时要重点开发;岷江上游干旱河谷等生态脆弱区要以限制和禁止开发的要求进行生态恢复与发展。     

美国海洋托莫公司的专利拍卖实践及启示

针对传统双边谈判存在的缺陷,文章使用截至2009年海洋托莫公司的拍卖数据,介绍专利拍卖这种新兴的技术转移手段,分析结果表明专利拍卖有其独特的优势,但无法替代传统交易机制,结合海洋托莫公司发展过程中成功的经验和面临的挑战,尝试性的提出若干建议,为我国发展专利拍卖模式提供参考。     

Effect of Oral Contraceptive Pills on the Blood Serum Enzymes and DNA Damage in Lymphocytes Among Users

The continuous use of synthetic hormones as contraceptive pill or hormonal replacement therapy among women is increasing day by day. The widespread use of different formulations as oral contraceptives by women throughout their reproductive cycle has given rise to a serious concern for studying the effects of oral contraceptives on enzymatic profile and DNA damage in peripheral blood lymphocytes among users. The present study was carried out on women taking oral contraceptives. The study was based on the questionnaire having the information of reproductive history, fasting, age, health, nature of menstrual cycle, bleeding and other disease. The profile of the blood serum enzymes i.e. alkaline phosphatase (ALP), gamma glutamyl transferase (GGT), lactate dehydrogenase (LDH), aminotransferases (SGOT and SGPT), serum proteins (albumin and globulin) and DNA damage in lymphocytes was studied among users and non-users. The results of the present study suggest that OCs not only effects enzymatic activity but also results in DNA damage that may vary with the duration of using oral contraceptives. A significant increase in LDH, GGT, SGPT, SGOT, globulin and decrease in ALP as well as albumin was found among users as compared to non-users. The observed DNA damage was more in users as compared to non-users. Hormonal contraceptives seem to exert DNA damage and also have significant effects on blood serum enzymes.     

企业决策层DNA及其对高管团队有限理性的影响——以我国企业专用性投资行为为例所作的分析

本文在梳理国外高管团队属性理论的基础上,提出了"决策层DNA"这一基本调节因素,将决策层的决策准则整合进高管团队属性效应分析框架当中,对理论进行了丰富。根据这一新的分析框架,对我国现阶段企业的专用性投资行为进行分析,归纳出导致我国企业专用性投资弱化的典型TMT属性特征和相应的决策层DNA类型。