Seminal plasma levels of 15-F2α-isoprostane, malondialdehyde and total homocysteine in normozoospermic and asthenozoospermic males

It has been proposed that oxidative stress plays an important role in male infertility. The aims of this study were to compare seminal plasma levels of 15-F2t-isoprostane (8-iso-PGF2α), malondialdehyde (MDA), and total (sum of free and bound) homocysteine (tHcy) from normozoospermic vs. asthenozoospermic men, and to examine the relationships between tHcy and lipid peroxidation products. The study was a case-control study with a simple random sampling. The case group was consisted of 15 asthenozoospermic males. This group was compared with 15 normozoospermic men. Seminal plasma levels of 15-F2α-isoprostane and tHcy were measured using commercially available enzyme immunoassay (EIA) kits. MDA levels were determined by the thiobarbituric acid (TBA) assay. The Mann-Whitney U test was used to compare two groups. Coefficients of correlation were calculated using Spearman’s correlation analysis. All hypothesis tests were two-tailed with statistical significance assessed at the p value <0.05 level. MDA levels were higher in asthenozoospermic subjects than in control subjects (0.72±0.06 μM vs. 0.40±0.06 μM; p<0.05). No differences were seen in 15-F2α-isoprostane levels in asthenozoospermic subjects and controls (65.00±3.20 pg/ml vs. 58.17±4.12 pg/ml; p>0.05). Interestingly, tHcy levels were to be slightly higher in asthenozoospermic subjects than in controls (6.18±1.17 μM vs. 4.8±0.52 μM). Sperm motility was inversely correlated with seminal plasma 15-F2α-isoprostane and MDA levels, respectively (p<0.05). In summary, seminal plasma levels of 15-F2α-isoprostane and tHcy showed no significant difference between normozoospermic and asthenozoospermic men. Sperm motility was not correlated with seminal plasma levels of tHcy. No relationship was found between tHcy and lipid peroxidation.     

Serum lipids and malondialdehyde levels in primiparous patients with pregnancy induced hypertension

Background  Pregnancy induced hypertension (PIH) contributes to 15.6% maternal mortality in India. In Behrampur, Orissa, maternal deaths due to PIH was 32%, which is twice the national incidence. Hence in this population, some factors associated with severity of PIH were studied. Serum lipid concentrations and malondialdehyde (MDA) levels were correlated with severity of PIH and birth weight of the neonate. Patients & Methods  70 primiparous PIH patients and 20 healthy controls were studied. Serum lipids and MDA were estimated. Maternal blood pressures and birth weights of the neonate were recorded. Results and Conclusion  Serum cholesterol, triglyceride, LDL, VLDL and MDA were significantly elevated in primiparous PIH patients when compared to control subjects. Average birth weight of babies born to mothers with PIH was less than those born to control subjects. The most significant factor was that in this geographical area, 26% of the primiparous patients with PIH were below 20 years of age while only 15% of the controls were less than 20 years, indicating that younger maternal age was a contributing factor to PIH.     

Lipid peroxidation and the levels of antioxidant enzymes in coronary artery disease

Coronary Artery Disease is the major cause of mortality and morbidity worldwide. Traditional risk factors account for only half of the morbidity and mortality from coronary artery disease. There is substantial evidence that oxidative stress plays the major role in the atherosclerotic process. The present study was undertaken to evaluate the level of lipid peroxidation (by measuring malondialdehyde) and antioxidant enzymes (ceruloplasmin, glutathione, superoxide dismutase) in coronary artery disease. Serum malondialdehyde levels and serum ceruloplasmin levels were significantly raised in all the subgroups of study group as compared to control group (p<0.001). Whole blood glutathione levels and hemolysate superoxide dismutase activity was significantly decreased in all the subgroups of study group as compared to control group (p<0.001). Above results suggests that the patients of coronary artery disease show increased oxidative stress and decreased levels of antioxidant enzymes. So it is recommended that the management protocol for coronary artery disease patients should include antioxidant supplementation along with simultaneous lowering of lipid peroxidation.     

Evaluation of adenosine deaminase activity and lipid peroxidation levels in diabetes mellitus

There was increase in erythrocyte lipid peroxidation and adenosine deaminase (ADA) activity in red blood cells (RBC's), white blood cells (WBC's) and plasma, in 30 patients of confirmed diabetes mellitus, 10 each of insulin dependent diabetes mellitus (IDDM or type I), non-insulin dependent diabetes mellitus (NIDDM or type II) and diabetes with ketoacidosis when compared with 20 healthy individuals (controls). Glycosylated hemoglobin A1c%, plasma free fatty acid (FFA) and glycerol levels were also elevated in all the cases when compared with controls. The increase was more in diabetic ketoacidosis group. Significant positive correlations were seen between erythrocyte lipid peroxidation and ADA activities in RBC's, WBC's and plasma. It is suggested that decreased tissue adenosine levels due to increase in ADA activity, is related to the severity of hyperglycemia and lipid peroxidation in diabetes mellitus.     

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.     

Effect of corticosteroids on elevated intracellular sodium, plasma lipid peroxide levels and reduced Na+, K+-ATPase activity in patients of bronchial asthma

In view of several reports that there is a lack of balance in free radicals in case of bronchial asthma (1) the effect of free radicals on cell membrane was studied by estimating the membrane bound protein Na⁺, K⁺-ATPase activity and the intracellular sodium level in patients of bronchial asthma before and after a short course (one week) of oral corticosteroid (prednisolone 0.75–1mg/kg body weight) therapy. Results showed that there is a definite statistically significant rise in free radical level and intracellular sodium level and a significant lowering of Na⁺, K⁺-ATPase activity in case of untreated bronchial asthma. After short course of therapy with oral corticosteroids, the free radical level and intracellular sodium level decreased significantly, together with a significant rise of the Na⁺, K⁺-ATPase activity. Also, a significant negative correlation (r=−0.74) between the lipid peroxide level and the Na⁺,-K⁺-ATPase activity was found in these cases.     

Association of Inflammatory Cytokines,Lipid Peroxidation End Products and Nitric Oxide with the Clinical Severity and Fetal Outcome in Preeclampsia in Indian Women

Preeclampsia is a multisystem disorder associated with maternal hypertension, placental abnormalities and adverse fetal outcomes. The various pathways involved in its etiology include endothelial dysfunction, inflammatory milieu, lipid peroxidation and immunological imbalance. The present study was conducted to evaluate the causative and predictive role of nitric oxide, lipid peroxidation end products (MDA) and inflammatory cytokines (IL-6, TNF-α) in clinical presentation, severity and fetal outcome in preeclampsia. The study population was divided into 3 groups- Non- pregnant females comprising the control population; G1 and G2 groups included normal pregnant and pregnant females with preeclampsia with 50 patients in each group. Nitric Oxide and MDA levels were found to be highest in the preeclamptic patients as compared to other two groups. ROC curve analysis shows the superiority of the inflammatory markers as determinants of severity of preeclampsia which suggests the emerging role of pro inflammatory markers in the various pathological changes in preeclampsia. TNF-α emerged as the best marker in multivariate analysis and thus, has the potential for being used as a marker for PIH. Our study illustrates the multifactorial etiology of preeclampsia involving oxidative stress, proinflammatory milieu and endothelial dysfunction.     

中国海水养殖的净碳汇及其与经济耦合关系

中国是世界第一海水养殖大国,努力促进海水养殖业经济、环境协调发展,对落实节能减排要求、共谋全球生态文明建设具有意义。本文通过估算中国海水养殖净碳汇并评价其与海水养殖经济之间的耦合程度,探讨中国海水养殖业环境效益与经济效益的协调共生关系。研究结果表明：2008—2016年全国海水养殖净碳汇保持在43万~49万t,净碳汇与海水养殖经济耦合程度低,除2010年短暂达到增长耦合状态,2009—2014年间其他年份均处于非同步断裂关系,这一阶段中国海水养殖业仍依赖数量型增长,2015—2016年进入非同步负断裂阶段,此时海洋生态文明建设初见成效,但仍缺少环境效益向经济效益转化的市场机制;从省际来看,2008—2016年除冀、琼、津的海水养殖净碳汇为负外,净碳汇贡献最大的省依次为粤、闽、鲁、辽、桂、浙、苏,其中闽、浙、苏海水养殖业净碳汇与经济间主要呈现非同步断裂关系,产业发展仍侧重于经济增长,辽、鲁则呈现非同步负断裂趋势,环境效益提升显著快于经济效益增加,而粤、桂的海水养殖业经济、环境效益则接近平衡。     

中国能源水足迹时空特征及其与水资源匹配关系

能源与水资源对人类生存和社会发展至关重要,能源水足迹能够反映能源生产过程中真实的水资源占用情况。本文借助能源水足迹评价模型测算中国30个省（市、自治区）化石能源和电力生产生命周期水足迹,研究2004—2016年中国原煤、原油、天然气、水电、火电5类能源水足迹时间和空间格局演化特征,分析中国能源水足迹与水资源空间匹配关系。结果表明：①在研究期内,化石能源水足迹以2012年为界先增后减,水电水足迹快速增长助推电力水足迹持续增长。②在空间格局上,化石能源水足迹以胡焕庸线为界西向增加东向减少,以蒙晋陕地区为高值集聚区;而电力水足迹中水电水足迹与火电水足迹的空间分界显著,水电水足迹的快速增长使长江流域、珠江流域及东南沿海逐渐形成电力水足迹高值集聚区。③能源水足迹与水资源的空间匹配程度以南高北低格局呈波动下降趋势,化石能源水足迹较电力水足迹与水资源的空间匹配度低,原煤生产与火力发电的能-水矛盾最突出,全国1/3的地区存在能-水不匹配问题,能源水足迹高的华北地区能-水匹配压力大。能源生产与水资源配置上的矛盾仍然存在。真实反映能源水足迹与水资源的匹配关系,有助于优化能源与水资源综合管理,为最大限度的发挥能-水协同作用提供量化依据。     

中国县域地面坡谱分级及其与人口分布的关系

针对平均坡度指标难以稳健描述地面坡谱特征的问题,提出一种基于频率累加分位归并的坡谱分级方法。作为验证,运用数字高程模型数据将全国县域分为5个坡级,借助2000年和2020年人口普查数据分析了坡级与人口分布的关系。结果发现：（1）所提出的分级方法包含频率累加曲线的构建、基于分位数的参考曲线生成、基于相似度的类型归并3个关键步骤,由此得到的全国县域坡级划分方案具备稳健坡度梯度性、宏观空间连片性以及清晰地学含义。（2）全国县域人口数量总体保持随坡级升高而波动式缩小的特征,且二者间呈现明显的线性负相关关系,线性拟合R2从2000年的0.761上升到了2020年的0.845,20年间人口总数变化量与坡级的线性拟合R2达0.963;人口密度的极端值对其自身的坡级分布有较大影响,当剔除人口密度小于20人/km2和大于2000人/km2的区域后,两个分析年份全国县域人口密度均稳健保持着随坡级升高而线性减小（R2> 0.985）。本文为稳健表达如坡度等环境梯度提供了一种新的可行分级方法,并深化了对中国县域人口分布与坡度关系的认识。