Erythrocyte glutathione status in human visceral leishmaniasis

A glutathione redox cycle is a major antioxidant defense system for the detoxification of reactive oxygen species within erythrocytes. Reactive oxygen species such as superoxide anions, hydrogen peroxide and hydroxyl radicals are generated as a host defense mechanism for killing of engulfed Leishmania donovani, a causative agent of visceral leishmaniasis, are capable of damaging lipids and other biomolecules when produced in excess. Erythrocytes are most vulnerable to Reactive oxygen species. In present study we aimed to evaluate erythrocyte reduced glutathione (GSH) levels as an antioxidant and erythrocyte malondialdehyde (MDA) as a marker of lipid peroxidation. The study included twenty-five Visceral leishmaniasis patients and they were followed up after their complete chemotherapy with antileishmanial drugs (sodium stibogluconate) for 30 days. Forty six age and sex matched healthy individuals were taken as controls. GSH levels in erythrocytes of visceral leishmaniasis patients were increased in spite of significant increased erythrocyte MDA as compared to controls. Whereas erythrocyte GSH and MDA levels of follow up patients were decreased as compared to patients before treatment groups. We concluded that visceral leishmaniasis patients are in oxidative stress which most likely induces the endogenous antioxidant such as GSH or its poor utilization by cells.     

Effect of short term supplementation of tomatoes on antioxidant enzymes and lipid peroxidation in type-II diabetes

The objective of the present study is to evaluate the beneficial effect of tomatoes, which are rich source of Lycopene, relatively a new carotenoid known to play an important role in human health and disease. In this study lipid peroxidation rate was measured by estimating Malondialdehyde and the levels of serum enzymes involved in antioxidant activities like Super Oxide Dismutase, Glutathione Peroxidase, Glutathione Reductase, Reduced Glutathione, in type-II diabetic group (n=40) and age matched control group (n=50), and observed significantly lower levels of antioxidant enzymes and very high lipid peroxidation rate in type-II diabetes when compared to control group (p<0.001). Short term supplementation with tomatoes (cooked) to diabetic group for a period of 30 days, showed a significant improvement in antioxidant enzyme levels (p<0.001) and decreased lipid peroxidation rate (p<0.001) suggesting the supplementation with tomato lycopene may serve as the best method of preventing the oxidative stress in diabetic patients.     

Lipid peroxidation and glutathione peroxidase in ischemic heart disease

With the growing interest in the concept of free radicals in the pathogenesis of myocardial ischemia, it was thought worthwhile to study the changes in lipid peroxides and antioxidant enzyme glutathione peroxidase (GPx) in ischemic heart disease (IHD). The study was carried out on 76 patients of IHD-38 of acute myocardial infarction (AMI) and 38 of stable ischemic heart disease (SIDH). They were age and sex matched with 38 normal healthy controls. A significant increase (p<0.001) in lipid peroxides as malondialdehyde (MDA) (5.9±0.7 mmol/L) and a decrease in GPx (24.6±2.2 U/gmHb) was found in patients of AMI when compared with controls. There was no significant difference in these values in SIHD. Thus this study confirms the earlier findings that MDA and GPx are useful parameters in IHD and their magnitude is dependent on severity and/or duration of ischemia. We suggest that these tests would be of use in smaller institutions with limited facilities.     

Blood glutathione levels in head and neck malignancies

Blood glutathione was estimated in fifty patients of head and neck cancer in the age group of 18–76 years and the results were compared with a group of normal healthy controls. Mean blood glutathione level was found to be significantly lowered in patients than the controls. Irrespective of the site, TNM classification, histopathology, and character of lesion, fall in blood glutathione was nearly same in all the patients. The mean level was significantly increased after radiotherapy when compared with the levels before radiotherapy. The decreased levels of GSH in-patients with head and neck cancer, observed in the present study, may be due to its increased utilization by the cells. The results suggest that patients with head and neck cancer have increased oxidative stress.     

Influence of blood specimen collection method on various preanalytical sample quality indicators

Preanalytical errors contribute to a large proportion of total laboratory errors. In order to achieve continuous laboratory improvement, it is important to focus on all phases of patient specimen testing i.e. preanalytical, analytical and post-analytical. With large variations in the way venous blood specimens are collected using diverse devices in the country, the effect of such practices on specimen quality is not known. The purpose of this study was to monitor fourteen specimen preanalytical quality indicators in order to compare the usage of evacuated blood collection devices with needle and syringe open collection using either disposable tubes or re-washed glass vials. The study involved 26638 patient specimens assessed over a period of 6 months. The results demonstrated that evacuated closed blood collection resulted in an approximate 100-fold reduction in the incidence of hemolysis in samples. Similarly, there was a 200-fold reduction in incidence of insufficient specimen quantity while using evacuated collection system. It was also found that incidence of specimen contamination, improper volume of sample collected, and specimen spillage was also lower when the evacuated collection system was used. Further, it was also observed that the facility with a laboratory information system demonstrated much lower specimen identification and related errors. The observed results clearly demonstrate that the usage of the evacuated blood collection system resulted in improvement of preanalytical specimen quality as compared to needle and syringe usage.     

Protective influence of vitamin E on the antioxidant defence system in the whole blood and liver of normal and alloxan-induced diabetic rats

The effect of oral administration of vitamin E for twenty-eight consecutive days on blood glucose, reduced glutathione levels, antioxidant enzymes (superoxide dismutase and catalase activities), and levels of malondialdehyde (as an index of free radical-mediated lipid peroxidation) was observed in the whole blood and liver of normal and alloxan-induced diabetic rats. It was found that oral administration of vitamin E significantly (p<0.05) lowered the blood glucose level and increased the body weight of the diabetic rats. The activities of superoxide dismutase and levels of reduced glutathione increased significantly (p<0.05) while the level of lipid peroxidation decreased.     

The 'mandarin-missionary' strategy: Robert Kennicott, Spencer Fullerton Baird and specimen collection in the Hudson's Bay Territory

In 1859, Robert Kennicott, one of the most promising specimen collectors and young naturalists in the United States, was dispatched to Hudson's Bay Territory by Spencer Fullerton Baird, the Assistant Secretary of the Smithsonian. Kennicott was chosen because of previous experience in Canada, the familiarity with biota of the American Midwest, and because he had a boundless, infectious, enthusiasm for natural history that was typical among Baird's closest protégées. Kennicott was a natural scientific envoy--or missionary--to the officers of the Hudson's Bay Company, and many officers were enthusiastically 'converted' to the cause of collecting and/or overseeing the collection of natural history specimens. Due to this collaboration between Baird, Kennicott and the officers of the Hudson's Bay Company, the Smithsonian became a leading center of Canadian natural history in the Western hemisphere.     

A biochemical study on variability of Superoxide dismutase,Catalase and Glutathione peroxidase in dry cleaners

Several chemicals which induce cytotoxicity are broadly classified into three types and they are organophosphate, organochlorine and carbomate compounds. Perchloroethylene has been clearly identified as a carcinogen in experimental animals and it’s a very common carcinogen used for dry clean purpose. Hence, in the present study, blood samples from dry cleaners were taken, Superoxide dismutase, Catalase and Glutathione peroxidase activity was estimated in blood samples of dry cleaners. There was a significant increase in the activity of Catalase, Glutathione Peroxidase, Superoxide Dismutase in dry cleaners of chronically exposed to perchloroethylene as compared to controls. The increased activities of antioxidant enzymes may be a compensatory regulation in response to increased oxidative stress induced by perchloroethylene.     

Influence of method of specimen collection on various preanalytical sample quality indicators in EDTA blood collected for cell counting

Improving specimen quality as well as healthcare worker (HCW) safety poses significant concerns for today’s laboratories. With an increasing number of diagnostic tests requested, laboratory professionals are faced with challenges to reduce laboratory errors, improve the quality of laboratory results to assure accurate diagnosis and implement initiatives to ensure healthcare worker safety and minimize risk of exposure to bloodborne pathogens. A prior study conducted in 2008 reported that variations in blood collection methods for clinical chemistry assays may affect overall specimen quality. As a follow up, the current study assessed the quality of 22563 patient specimens for cell counting in EDTA blood collection tubes that were obtained with needle and syringe collection (open) using either disposable tubes or re-washed glass vials or with an evacuated blood collection system (closed). Based on the observations, the use of the evacuated blood collection system resulted in better preanalytical specimen quality as compared with needle and syringe collection. The findings also showed an approximately 70-fold reduction in the incidence of clotting as well as fewer instrument-generated flags using the evacuated collection system. In addition, the use of an evacuated collection system for venous blood collection demonstrated lesser chance of blood exposure to healthcare workers.     

Oxidative stress, α-tocopherol, ascorbic acid and reduced glutathione status in schizophrenics

A disturbance in the antioxidant defense system including α-tocopherol, ascorbic acid and reduced glutahtione metabolism due to free radical induced oxidative injury has been implicated in various neuro-psychiatric disorders. The roles of these antioxidants, changes in their blood levels and correlation with oxidative stress were studied in a common psychiatric illness Schizophrenia. Fifty-eight subjects of either sex ranging in age from 18–60 years divided into two age groups (≤40 and >40 years) diagnosed for schizophrenia, and forty age and sex-matched normal subjects as controls were included in the study. Blood samples were analyzed for malondialdehyde (MDA), α-tocopherol, total ascorbic acid (TAA), dehydro ascorbic acid (DHAA), reduced ascorbic acid (RAA), leucocyte ascorbic acid (LAA) and reduced glutathione (GSH). A decrease in the levels of α-tocopherol, total ascorbic acid and reduced glutathione was found in schizophrenics compared to normal controls. Further a significant rise in oxidative stress and decreased antioxidant status was observed in the chronic stage of schizophrenia as compared to those in acute condition. A significant rise in dehydroascorbic acid with concomitant fall in reduced ascorbic acid suggests scavenging action of ascorbic acid and its utilization with increased oxidative stress as indicated by high blood malondialdehyde levels. Leucocyte ascorbic acid, a better index of ascorbic acid status was also found to be reduced in schizophrenics, suggesting depletion of body stores of ascorbic acid and the condition worsened with advancing age.     

典型DC-DC变换电路设计与分析

本文介绍了DC-DC变换电路原理及分类;讨论了三种典型DC-DC变换电路即Buck电路、Boost电路和Buck-Boost电路的原理、结构、电压变换关系,并在Matlab软件建立仿真模型验证了理论分析的正确性;比较了这三种典型DC-DC变换电路的优缺点。     

An opium alkaloid-papaverine ameliorates ethanol-induced hepatotoxicity: Diminution of oxidative stress

In this communication, we show the modulatory potential of papaverine, an opium alkaloid and a well known vasodilator agent on the ethanol-induced hepatic oxidative stress in male Wistar rats. Ethanol treatment (50% v/v) enhanced lipid peroxidation significantly accompanied by a decline in the activities of glutathione peroxidase (G-Px), glutathione reductase (GR) and depletion in levels of hepatic glutathione (GSH). Ethanol administration increased hepatic glutathione-s-transferases (GST). Enhanced lipid peroxidation induced by ethanol was significantly reduced when papverine was coadministered (P<0.05). In addition, the depleted levels of glutathione and inhibited activities of G-Px and GR recovered significantly (P<0.05) levelling off to control values on co-exposure. Papaverine (200 mg/kg bw) effectively antagonised the ethanol-induced lipid peroxidation and impaired glutathione levels and glutathione dependent enzyme systems. Our results suggest that papaverine is an effective chemopreventive agent in the liver and may suppress the ethanol-induced hepatotoxicity.     

Comparison of lipid profile and antioxidant enzymes among south Indian men consuming coconut oil and sunflower oil

In this study, we compared the lipid profile and antioxidant enzymes of normal and diabetic subjects consuming two different types of oil as cooking medium. 70 normal, healthy subjects were taken as controls and 70 subjects with Type 2 diabetes were recruited in patient group. Each group was further subdivided into two subgroups of 35 subjects each, consuming coconut oil and sunflower oil respectively as cooking medium. Samples of blood were collected and analyzed for serum total cholesterol, triacylglycerols, and cholesterol in lipoprotein fractions. Total glutathione and glutathione peroxidase were measured in erythrocytes and superoxide dismutase in serum. Triacylglycerols, LDL and VLDL cholesterol levels were high in the diabetic subjects compared to the controls. Total glutathione and glutathione peroxidase values showed significant decrease in diabetic subjects as compared to the controls, while superoxide dismutase values showed significant difference between coconut oil consuming groups. Though lipid profile parameters and oxidative stress were high in Type 2 diabetic subjects compared to controls, no pronounced changes for these parameters were observed between the subgroups (coconut oil vs. sunflower oil).     

Effect of ethanol on liver antioxidant defense systems: Adose dependent study

Alcohol induced oxidative stress is linked to the metabolism of ethanol. In this study it has been observed that administration of ethanol in lower concentration caused gain in body and liver weight. while higher concentration of ethanol caused lesser gain in body and liver weight. Ethanol treatment enhanced lipid peroxidation significantly, depletion in levels of hepatic glutathione and ascorbate, accompanied by a decline in the activities of glutathione peroxidase and glutathione reductase, and increased in hepatic glutathione s-transferase activity. Interestingly catalase activity increases in lower concentration of ethanol exposure, and decreased in higher concentration. Superoxide dismutase activity was also increased on ethanol exposure. But, ethanol feeding did not show any effect on glucose-6-phosphate dehydrogenase activity. Ethanol ingestion perturbs the antioxidant system in a dose and time dependent manner.     

酶法合成13C标记尿苷二磷酸葡萄糖的核磁鉴定

建立了一种经济、简便的一步酶法 ,大量合成尿苷二磷酸葡萄糖 .在酶法合成中 ,用UTP代替ATP ,并建立了UTP的再生系统 ;建立了反复补加法和酶回收法 ,使酶的利用率达到最高 .UDP [4 13 C] 葡萄糖首次用该法在 0 5g规模上合成 .总产率为 69 7% .UDP [4 13 C] 葡萄糖的核磁共振 (NMR)结果表明 ,文献报道的UDPG的1H和13 C核磁共振谱中葡萄糖 4位C的归属是错误的 ,从而纠正了文献中关于UDPG核磁共振谱归属中的部分错位 .     

Oxidative stress is the primary event: Effects of ethanol consumption in brain

Damaging effects of reactive oxygen species on living systems are well documented. They include oxidative attack on vital cell constituents. Chronic ethanol administration is able to induce an oxidative stress in the central nervous system. In the present study, 16–18 week-old male albino rats of Wistar strain were exposed to different concentration of ethanol for 4 weeks. This exposure showed profound effect on body weight. Ascorbic acid level; and activities of alkaline phosphatase and aspartate transaminase in the brain are dependent on the concentration of ethanol exposure. Chronic ethanol ingestion elicits statistically significant increase in thiobarbituric acid reactive substances level and decrease in gluatathione level in the brain. It reduces superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activities in a dose dependent manner. However, histological examination could not reveal any pathophysiological changes. Therefore, we conclude that biochemical alterations and oxidative stress related parameters respond early in alcoholism than the histopathological changes in brain.     

Study of Oxidative Stress in Vitiligo

Vitiligo is an idiopathic, acquired, circumscribed, hypomelanotic skin disorder, characterized by milky white patches of different sizes and shapes. It is due to the destruction of melanocytes resulting in the absence of pigment production of the skin and mucosal surfaces. Oxidative stress has been implicated in pathophysiology of vitiligo. To study the activity of blood Superoxide dismutase (SOD) and Glutathione peroxidase (GPx) in vitiligo patients. A case–control study was conducted in which 100 patients were enrolled after written consent. 50 cases were of active vitiligo and 50 served as control (25 healthy control and 25 with stable vitiligo). SOD—In our study, among the active vitiligo cases 90% had high level of SOD and 10% had normal level of SOD. Among the stable vitiligo controls, 92% had normal level of SOD and 8% had low levels of SOD.The difference between active vitiligo cases and stable vitiligo control as well as with healthy control was statistically significant (P value < 0.05). GPx—Among the active vitiligo cases 74% had normal GPx levels, 22% had low and only 4% had high levels of GPx. Among the stable vitiligo controls, 64% had normal GPx levels, 16% had low, and 20% had high levels of GPx. The difference between active vitiligo cases and stable vitiligo control as well as with healthy control was statistically not significant (P value > 0.05). Our study shows that oxidative stress is involved in the pathophysiology of vitiligo, as indicated by the high levels of serum superoxide dismutase activity.     

体验之花 精彩绽放

21世纪是体验的世纪。因此,也让我们更清醒地认识到：呼唤生态的教育,打造生态的课堂,让生命得以充分舒展,势在必行。我园在课题的引领下,以生态体验为切入口,确立了“为幼儿发展服务,为教师成长服务”的科研意识,以“优质低碳和谐共长”的生态课堂核心理念为引领,努力营造学习和研究的科研体验氛围,创设为教师平等对话的平台,促进幼儿富有个性地成长。     

软件测试的重要性

随着市场对软件质量要求的不断提高,软件测试愈来愈受到重视。介绍了软件测试的重要性,对几种软件测试技术进行了论述。     

任务型课堂教学的重要性

本文通过分析在任务型课堂教学中教师所起的作用以及活动类型和注意要点,阐明了任务型教学的重要性。