共查询到20条相似文献，搜索用时 25 毫秒
1.
Vidya Akhileshwar Samir P. Patel Surendra S. Katyare 《Indian journal of clinical biochemistry : IJCB》2007,22(1):84-90
Studies were carried out to examine and compare the effects of alloxan-diabetes on reactive oxygen species (ROS) related parameters
in the heart from male and female rats. Effects of insulin treatment were also evaluated. The diabetic state severely compromised
the ROS defense mechanism in the cardiac tissue and the effects were more pronounced in the female than in the male rats.
There was several fold increase in the xanthine oxidase (XO) activity in general and the magnitude of increase was higher
in the females; insulin treatment resulted in further increase in the XO activity. The glucose-6-phosphate dehydrogenase (G6PDH)
and catalase activities decreased and the reduced glutathione (GSH) content in mitochondria was completely depleted in diabetic
state with significant decrease in the GSH levels in the post-mitochondrial fraction; the effect was more pronounced in the
females. The superoxide dismutase (SOD) and glutathione peroxidase (GPox) activities increased in the diabetic state to a
greater extent in male rats. Insulin treatment had restorative action only on some parameters. In conclusion, our results
suggest that diabetic state may further compromise the weak ROS defense systems in the heart thus initiating a lesion at the
level of mitochondria which ultimately leads to cardiomyopathy and the effects are especially more pronounced in the females.
Our results also pointed out that insulin treatment was ineffective in restoring ROS related parameters. 相似文献
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Gora Dadheech Praveen Sharma Shiv Gautam 《Indian journal of clinical biochemistry : IJCB》2012,27(3):278-283
Reactive oxygen species (ROS) formed in various metabolic reactions cause unlimited damage by attacking and oxidizing the macromolecules. An arsenal of antioxidant substances neutralizes these ROS at various sites of their metabolic cascade, and if disequilibrium exists between the pro and antioxidant system, oxidative stress persists. The present study was undertaken in schizophrenia, to highlight the response and role of some endogenous antioxidants viz. reduced glutathione (GSH), bilirubin, total proteins, albumin and uric acid in scavenging the ROS. The effect of severity of disease, age factor, and substance abuse was also studied. In all, 50 schizophrenics and 50 age and sex-matched controls were enrolled in the present study. Fasting blood samples were drawn for estimating malondialdehyde (MDA), GSH, bilirubin, total proteins, albumin and uric acid in both the groups. The results were statistically analyzed by Z-test and correlated using correlation coefficient (r). The study shows reduction in MDA levels and decline in the level of endogenous antioxidants, but within the normal range. Chronic schizophrenics were at a higher risk of oxidative stress and age and substance abuse seems to worsen the situation. 相似文献
4.
Munzir M. E. Ahmed J. A. S. Al-Obosi H. M. Osman M. E. Shayoub 《Indian journal of clinical biochemistry : IJCB》2016,31(2):162-170
Acetaminophen (APAP) a commonly used drug for decrease the fever and pain but is capable to induced hepatotoxicity at over dose. This study was carried out to investigate the effect of APAP on the expression of anti-apoptotic and antioxidative defense genes, and whether aldose reductase over-expressing plasmid capable to protect against APAP-induced oxidative stress and cell death. APAP treatment induced oxidative stress and hepatotoxicity, and significantly increased aldose reductase mRNA and protein expression in mouse hepatocyte (AML-12). Unexpectedly, AML-12 cells over-expressing aldose reductase augmented APAP-induced reduction in cell viability, reactive oxygen species (ROS) production, glutathione (GSH) depletion and glutathione S-transferase A2 expression. Moreover, over-expression of aldose reductase potentiated APAP induced reduction on proliferating cell nuclear antigen, B cell lymphoma-extra large (bcl-xL), catalase, glutathione peroxidase-1 (GPx-1) and abolished APAP-induced B-cell lymphoma 2 (bcl-2) inductions. Further, over-expression of aldose reductase significantly abolished AMP activated protein kinase (AMPK) activity in APAP-treated cells and induced p53 expression. This results demonstrate that APAP induced toxicity in AML-12, increased aldose reductase expression, and over-expression of aldose reductase render this cell more susceptible to APAP induced oxidative stress and cell death, this probably due to inhibition AMPK or bcl-2 activity, or may due to competition between aldose reductase and glutathione reductase for NADPH. 相似文献
5.
Singh PP Chandra A Mahdi F Roy A Sharma P 《Indian journal of clinical biochemistry : IJCB》2010,25(3):225-243
The antioxidants are essential molecules in human system but are not miracle molecules. They are neither performance enhancers
nor can prevent or cure diseases when taken in excess. Their supplemental value is debateable. In fact, many high quality
clinical trials on antioxidant supplement have shown no effect or adverse outcomes ranging from morbidity to all cause mortality.
Several Chochrane Meta-analysis and Markov Model techniques, which are presently best available statistical models to derive
conclusive answers for comparing large number of trials, support these claims. Nevertheless none of these statistical techniques
are flawless. Hence, more efforts are needed to develop perfect statistical model to analyze the pooled data and further double
blind, placebo controlled interventional clinical trials, which are gold standard, should be implicitly conducted to get explicit
answers. Superoxide dismutase (SOD), glutathione peroxidase and catalase are termed as primary antioxidants as these scavenge
superoxide anion and hydrogen peroxide. All these three enzymes are inducible enzymes, thereby inherently meaning that body
increases or decreases their activity as per requirement. Hence there is no need to attempt to manipulate their activity nor
have such efforts been clinically useful. SOD administration has been tried in some conditions especially in cancer and myocardial
infarction but has largely failed, probably because SOD is a large molecule and can not cross cell membrane. The dietary antioxidants,
including nutrient antioxidants are chain breaking antioxidants and in tandem with enzyme antioxidants temper the reactive
oxygen species (ROS) and reactive nitrogen species (RNS) within physiological limits. Since body is able to regulate its own
requirements of enzyme antioxidants, the diet must provide adequate quantity of non-enzymic antioxidants to meet the normal
requirements and provide protection in exigent condition. So far, there is no evidence that human tissues ever experience
the torrent of reactive species and that in chronic conditions with mildly enhanced generation of reactive species, the body
can meet them squarely if antioxidants defense system in tissues is biochemically optimized. We are not yet certain about
optimal levels of antioxidants in tissues. Two ways have been used to assess them: first by dietary intake and second by measuring
plasma levels. Lately determination of plasma/serum level of antioxidants is considered better index for diagnostic and prognostic
purposes. The recommended levels for vitamin A, E and C and beta carotene are 2.2–2.8 μmol/l; 27.5–30 μmol/l; 40–50 μmol/l
and 0.4–0.5 μmol/l, respectively. The requirement and recommended blood levels of other dietary antioxidants are not established.
The resolved issues are (1) essential to scavenge excess of radical species (2) participants in redox homeostasis (3) selective
antioxidants activity against radical species (4) there is no universal antioxidant and 5) therapeutic value in case of deficiency.
The overarching issues are (1) therapeutic value as adjuvant therapy in management of diseases (2) supplemental value in developing
population (3) selective interactivity of antioxidant in different tissues and on different substrates (4) quantitative contribution
in redox balance (5) mechanisms of adverse action on excess supplementation (6) advantages and disadvantages of prooxidant
behavior of antioxidants (7) behavior in cohorts with polymorphic differences (8) interaction and intervention in radiotherapy,
diabetes and diabetic complications and cardiovascular diseases (9) preventive behavior in neurological disorders (10) benefits
of non-nutrient dietary antioxidants (11) markers to assess optimized antioxidants status (12) assessment of benefits of supplementation
in alcoholics and heavy smokers. The unresolved and intriguing issues are (1) many compounds such as vitamin A and many others
possessing both antioxidant and non-antioxidant properties contribute to both the activities in vivo or exclusively only to
non-antioxidant activity and (2) since human tissues do not experience the surge of FR, whether there is any need to develop
stronger synthetic antioxidants. Theoretically such antioxidants may do more harm than good. 相似文献
6.
Gora Dadheech Sandhya Mishra Shiv Gautam Praveen Sharma 《Indian journal of clinical biochemistry : IJCB》2006,21(2):34-38
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. 相似文献
7.
The correlation between antioxidant capacity and oxidative damage during aging has been reported in several tissues in different
species. Glutathione-S-transferases (GST) can metabolise endogenous and exogenous toxins and carcinogens by catalysing the
conjugation of diverse electrophiles with reduced glutathione (GSH). We observe a significant (P < 0.001) increase in plasma GST activity as a function of human age (r = 0.5675). A significant (P < 0.001) positive correlation (r = 0.8979) is observed between GST activity and total plasma antioxidant potential measured
as ferric reducing ability of the plasma (FRAP). GST activity and red cell intracellular GSH also show a significant positive
correlation (r = 0.7014). We hypothesize that the increased activity of plasma GST is a manifestation of increased generation
of ROS and a concomitant decrease in the level of plasma antioxidant capacity during aging. 相似文献
8.
Vasudha Shukla Manish Vashistha Som Nath Singh 《Indian journal of clinical biochemistry : IJCB》2009,24(1):70-75
Aqueous and alcoholic extracts of amalki (Emblica officinalis), spirulina and wheatgrass were prepared and analyzed for antioxidant
vitamin content (vitamin C and E), total phenolic compounds. Antioxidant status, reducing power and effect on glutathione
S-transferase (GST) activity were evaluated in vitro. Vitamin C content of crude amalaki powder was found to be 5.38 mg/g,
while very less amount 0.22 mg/g was detected in wheat grass. Amalki was rich in vitamin E like activity, total phenolic content,
reducing power and antioxidant activity. Total antioxidant activity of aqueous extract of amalki, spirulina and wheat grass
at 1mg/ml concentration were 7.78, 1.33 and 0.278 mmol/l respectively. At similar concentrations the total antioxidant activity
of alcoholic extract of amalaki, spirulina and wheat grass was 6.67, 1.73 and 0.380 mmol/l respectively. Amalki was also found
to be rich source of phenolic compounds (241mg/g gallic acid equivalent). Alcoholic extract of wheat grass showed 50 % inhibition
in FeCl2- ascorbic acid induced lipid peroxidation of rat liver homogenates in vitro. Both aqueous and alcoholic extracts of amalaki
inhibited activity of rat liver glutathione S-transferase (GST) in vitro in dose dependant manner. Since GST acts as powerful
drug metabolizing enzyme its inhibition by amalaki offers possibility of its use for lowering therapeutic dose of herbal preparations.
The aqueous extracts of both amalki and spirulina also showed protection against t-BOOH induced cytotoxicity and production
of ROS in cultured C6 glial cells. 相似文献
9.
Antonija Perovic Adriana Unic Jerka Dumic 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2014,24(2):235-247
Environmental conditions and increased physical activity during scuba diving are followed by increased production of free radicals and disturbed redox balance. Redox balance disorder is associated with damage of cellular components, changes of cellular signaling pathways and alterations of gene expression. Oxidative stress leads to increased expression of sirtuins (SIRTs), molecules which play an important role in the antioxidant defense, due to their sensitivity to the changes in the redox status and their ability to regulate redox homeostasis. These facts make SIRTs interesting to be considered as molecules affected by scuba diving and in that sense, as potential biomarkers of oxidative status or possible drug targets in reduction of reactive oxygen species (ROS) accumulation. In addition, SIRTs effects through currently known targets make them intriguing molecules which can act positively on health in general and whose expression can be induced by scuba diving.A demanding physical activity, as well as other circumstances present in scuba diving, has the greatest load on the cardiovascular function (CV). The mechanisms of CV response during scuba diving are still unclear, but diving-induced oxidative stress and the increase in SIRTs expression could be an important factor in CV adaptation. This review summarizes current knowledge on scuba diving-induced oxidative and CV stress and describes the important roles of SIRTs in the (patho)physiological processes caused by the redox balance disorder. 相似文献
10.
D. P. Neupane S. Majhi L. Chandra S. Rijal Nirmal Baral 《Indian journal of clinical biochemistry : IJCB》2008,23(1):95-97
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. 相似文献
11.
Nasreen Noor Najmul Islam Shagufta Moin Abbas Ali Mahdi Sapna Jaiswal Farzana Bano 《Indian journal of clinical biochemistry : IJCB》2008,23(3):227-232
To probe the glutathione peroxidase (GPx) activity coupled to ROS and TNF-α levels in younger versus elderly primigravidas.
Monocytes were isolated from blood of young and elderly primigravidas after 12 hrs, 24 hrs and 14 days postpartum. Age-matched
healthy female donors served as controls. Thereafter, the above monocytes were subjected to evaluation of GPx activity, levels
of pro-inflammatory cytokine TNF-α and reactivity/specificity towards anti-TNF-α antibody. Suppression in GPx activity with
simultaneous enhancement of TNF-α levels in monocytes was observed after 12 hrs and 24 hrs of spontaneous labor pain-induced
maternal delivery through normal vaginal route. Conversely, an enhancement of GPx activity and decrease in TNF-α levels were
observed on day 14 of postpartum, thereby indicating reversal of the impaired neutralizing mechanisms. The antioxidant network
combating ROS was stronger in younger primigravidas. Capability of TNF-α and ROS suppression was somewhat lesser in elderly
primigravidas even 14 days of postpartum via normal vaginal route. The capability of GPx activity enhancement with simultaneous
suppression in ROS and TNF-α, decreases in elderly primigravidas. This may act as one of the important parameters leading
to a variety of complications encountered by elderly primigravidas. 相似文献
12.
Dietary spice components ofCurcuma longa andAbroma augusta have been screened for their protective effect against reactive oxygen species induced lipid peroxidation. They have been
found to be efficient antioxidant when administered in combination. The purpose of the study was to investigate the effect
of oral administration (300mg/Kg) of the aqueous extract of turmeric whose active ingredient isCurcumin andAbromine powder as a hypoglycemic agent mixed with diet. The effect of this aqueous extract on blood glucose, lipid peroxidation (LPO)
and the antioxidant defense system in rat tissues like liver, lung, kidney and brain was studied for 8 weeks in streptozotocin
induced diabetic rats. The administration of an aqueous extract of turmeric and abromine powder resulted in a significant
reduction in blood glucose and an increase in total haemoglobin. The aqueous extract also resulted in decreased free radical
formation in the tissues studied.
The decrease in thiobarbituric acid reactive substances (TBARS) and increase in reduced glutathione (GSH), superoxide dismutase
(SOD) and catalase (CAT) clearly showed the antioxidant property of the mixture. It is suggested that these changes initially
counteract the oxidative stress in diabetes however, a gradual decrease in the antioxidative process may be one of the factors
which results in chronic diabetes. These results indicate that the mixture of the two plants have shown antidiabetic activity
and also reduced oxidative stress in diabetes. A combination ofAbroma augusta and Curcuma longa also restored the other general parameters in diabetic animals. The results were statistically analyzed and indicated that
combination of herbal extracts showed better efficacy as compared to individual herbal plant extracts used. 相似文献
13.
A microgrid (MG) is a building block of future smart grid, it can be defined as a network of low voltage power generating units, storage devices and loads. System of systems (SoS) is another concept involving large scale integration of various systems. In this paper, we provide an overview of recent developments in modeling and control methods of microgrid as well as presenting the reason towards incorporating MG into the existing grid. Various SoS control strategies when applied to MG are discussed. 相似文献
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Superoxide dismutase (SOD) activities in the human and rat RBCs and rat liver, kidney, brain and heart mitochondria as well
as cytosolic fractions were determined by the pyrogallol assay procedure with slight modifications. Measurements were carried
out in 0.1 M potassium phosphate buffer pH 8.0 and 9.2 to assess the pH stability of the SODs from various systems. Under
these conditions the SODs from different systems including RBCs exhibited differential pH stability i.e. they displayed differential
susceptibility at pH 9.2. Even in a given tissue, the mitochondrial and cytosolic SODs contents show a tissue-specific pattern.
Our results also suggest that measurements carried out at pH 8.0 may give more realistic estimates of SOD activities. 相似文献
17.
The excessive generation of reactive oxygen species (ROS) by abnormal spermatozoa and contaminating leukocytes has been defined
as one of the few etiologies for male infertility. Administration of antioxidants in patients with ‘male factor’ infertility
has begun to attract considerable interest. The main difficulty of such an approach is our incomplete understanding of the
role of free radicals in normal and abnormal sperm function leading to male infertility. Mammalian spermatozoa membranes are
very sensitive to free radical induced damage mediated by lipid peroxidation, as they are rich in polyunsaturated fatty acids.
Limited endogenous mechanisms exist to reverse these damages. ROS attacks the fluidity of the sperm plasma membrane and the
integrity of DNA in the sperm nucleus. ROS induced DNA damage accelerate the germ cell apoptosis. Unfortunately spermatozoa
are unable to repair the damage induced by excessive ROS as they lack the cytoplasmic enzymes required to accomplish the repair.
Assessment of such oxidative stress status (OSS) may help in the medical treatment. Treatment strategies must be directed
toward lowering of ROS levels to keep only a small amount necessary to maintain normal cell function. 相似文献
18.
分布式拒绝服务攻击的原理与防范 总被引：1，自引：0，他引：1
讨论了拒绝服务与其他攻击相结合的方法,给出了拒绝服务攻击的定义,对其进行了全面而本质的模式分类,阐明了分布式拒绝服务攻击相对拒绝服务攻击的进步所在;深入介绍了分布式拒绝服务攻击的机制及形成这些机制的原因,对分布式拒绝服务的攻击方式做了详细的讨论;在此基础上,对现有的对抗手段提出了一种新的分类方法,进而进行了全面总结,并指出只有借助综合的防御体系,才能有效对抗分布式拒绝服务攻击;最后,指出了从根本上防范分布式拒绝服务攻击的方向。 相似文献
19.
武器装备采办管理的信息不对称研究 总被引：2，自引：0，他引：2
1 信息不对称的主要内容信息不对称理论是微观信息经济学研究的一个核心内容 ,用来说明在不完全信息市场上 ,相关信息在交易双方的不对称分布对市场交易行为的影响及由此产生的市场运行效率问题。在不对称信息对策研究中 ,通常将对策中占有信息优势的一方称为代理人 ,而处于信息劣势的一方称为委托人 ,不对称信息的所有模型都可以在委托人—代理人的框架下进行。经济学中最基本的假设是人都是有理性的 ,在各种约束条件下追求自身利益的最大化。因此在信息不对称的条件下 ,代理人为了自身利益可能凭借自己的信息优势选择对委托人不利的行为 … 相似文献
20.
S. K. Aggarwal Harjit Singh A. S. Saini 《Indian journal of clinical biochemistry : IJCB》1989,4(1):70-75
Red blood cells (RBC) from iron-deficient chidren were found to have decreased levels of reduced glutathione and reduced content
of glucose-6-phosphate dehydrogenase, glutathione peroxidase and glutathione reductase than RBC from normal control children.
These findings suggest an increased oxidant stress on iron-deficient red cells which may be one of the mechanisms responsible
for membrane alterations leading to shortened life span of erythrocytes in iron-deficiency anaemia. 相似文献