Effects Of Oxygen Free Radicals Research Articles

Contrast-induced nephropathy - prevention and treatment

Introduction and purpose: Contrast-induced nephropathy (CIN) is kidney damage that can occur after the administration of contrast agents used in medical imaging procedures like angiography and CT scans. The exact mechanism is not fully understood but is believed to involve direct toxic effects, changes in kidney blood flow, and inflammation. Diagnosis is based on increased serum creatinine levels after contrast exposure. CIN poses challenges due to the rising use of contrast imaging, an aging population, and the increasing prevalence of chronic conditions like diabetes and hypertension. The Aim of this article is to summarize information on how to prevent contrast-induced nephropathy. Review of medications and pre-procedural screening and monitoring helpful to lower risk of CIN. State of knowledge: Contrast-induced nephropathy (CIN) is a form of kidney damage that may occur following the administration of contrast agents used in medical imaging procedures. The exact mechanism of contrast-induced nephropathy is not fully understood, but it is believed to involve a combination of factors, including the direct toxic effects of the contrast agent on kidney cells, changes in blood flow to the kidneys, and the body's inflammatory response, direct effect of oxygen free radicals. The diagnosis of CIN is typically based on an increase in serum creatinine levels within a certain time frame after the administration of the contrast agent. According to European guidelines, the definition of CIN is increased creatinine level in serum by 25% from baseline or creatinine total level in serum increased by 0.5 mg/dL (44 µmol/L) 48-72h after contrast media administration. Material and methods. A review of the available literature of PubMed database from 1992 – 2024.

Editorial

Editorial

Thaddeus Robert Rudolph Mann. 4 December 1908—27 November 1993

Thaddeus Mann was a Polish biochemist who spent most of his scientific life in Cambridge, where he made important discoveries in male reproductive biology and semen analysis. Funded principally by the Agricultural Research Council, he provided much of the basic knowledge on the composition and origin of semen components in farm animals, relevant to storage of spermatozoa for artificial insemination and assessment of fertility. He made numerous landmark contributions. Contrary to established dogma at the time, he showed that the seminal sugar in all species was fructose, not glucose as had been assumed, and that it was secreted by the prostate and seminal vesicles under androgen control. He identified a copper-binding protein (designated haemocuprein) that was later shown to be superoxide dismutase, which helps to protect cells from the damaging effects of oxygen free radicals. Mammalian spermatozoa are especially sensitive to free radical damage as they are rich in unsaturated lipids and have a limited capacity for repair, being transcriptionally inactive. Two textbooks, published in 1954 and 1964 and outstanding for their scholarship, collated all the information on the biochemistry of mammalian spermatozoa and became the authoritative reference sources worldwide. These books were revised in 1982 with greater emphasis on diagnosis and treatment of infertility in human patients. The science of andrology and use of semen analysis in infertility clinics still depend heavily on this information. Thaddeus was awarded many honours for his research, both nationally and internationally, and leaves an important legacy in the field. Modest and generous to his staff, he is remembered with great respect and affection by colleagues around the world.

In vitro production of buffalo embryos in Colombia – results of the addition of growth factors and antioxidants to defined culture medium

To increase the success rate of the in vitro production (IVP) system of embryos in buffalo, it is necessary to improve parameters. This field requires more research since its results are low compared to cattle. In this study carried out in Colombia, a modification of the methodology to produce buffalo IVP embryos is described, and 24 non-lactating females, aged 4 to 11 years old were included. Follicular wave was synchronised by ablation of the follicles within the ovary, seven days later all follicles were aspirated to obtain oocytes for maturation, fertilisation and embryo production. For all culture media used, animal protein was avoided. Culture media were supplemented with growth factors and other molecules associated with embryonic development. Special care was taken in adding supplements to protect the zygotes against the harmful effect of oxygen free radicals in the culture medium. Two aspiration series were performed 15 days apart. The average number of oocytes obtained by aspiration was 11.33, the number of blastocysts was 3.05, and the obtained blastocyst production rate (36.2%) was higher than literature reports for this species; we hypothesise that this increase is associated with the supplements added. It was possible to observe a female that produced 50 oocytes. Subsequent research is needed to evaluate the effect of the medium on embryo quality and pregnancy rates. A cost analysis of the new proposed medium is required, since all supplements must be imported and handled with a cold chain of up to -80oC, making it more expensive and restricting widespread use. Finally, it is shown that with three embryos per aspiration, at least one pregnancy can be successful after the aspiration, which is one of the objectives of the IVP system.

The effect of curcumin on embryonic in vitro development in experimental polycystic ovary syndrome: An experimental study.

BackgroundPolycystic ovary syndrome (PCOS) is a common disease in women. Some plant compounds which have antioxidant properties, such as curcumin, may be useful for these patients when delivered orally or in vitro.Objective The aim of this study was to evaluate the impact of PCOS on oocyte quality and the effect of curcumin on in vitro fertilization of oocytes.Materials and Methods In this experimental study, Naval Medical Research Institute mice aged six to eight wk were used. Mice were divided into five experimental groups (control, experimental PCOS, curcumin 6, 12 and 24 μM). To induce experimental PCOS, estradiol valerate (100 mg/kg, IP) was injected. The total antioxidant capacity and production of malondialdehyde in ovarian tissue and blood serum were evaluated in all groups. Finally, 6, 12 and 24 μM of curcumin were added to the culture medium of the PCOS group oocytes and development in the different groups was evaluated.ResultsA high percentage of oocytes for fertilization were not in good condition in terms of number and quality in the group of PCOS. The addition of curcumin to the embryo culture medium was associated with a higher percentage of fertilized oocytes, two-cells and blastocysts. This increase was significant at a concentration of 24 μM (p 0.01).ConclusionGiven that adding curcumin seemed to improve fetal growth and prevent the harmful effects of oxygen free radicals on the culture medium, it is recommended to add a certain concentration of curcumin under normal conditions without oxidative stress.

Effect of Oxygen Free Radicals on Cardiac Contractile Activity and Sarcolemmal Na(+)-Ca(2+) Exchange.

BACKGROUND: Although oxygen free radicals have been shown to induce myocardial cell damage and cardiac dysfunction, the exact mechanism by which these radicals affect the heart function is not clear. Since the occurrence of intracellular Ca(2+) overload is critical in the genesis of cellular damage and cardiac dysfunction, and since the sarcolemmal Na(+)-Ca(2+) exchange is intimately involved in Ca(2+) movements in myocardium, this study was undertaken to examine the effects of oxygen free radicals on the relationship between changes in cardiac contractile force development and sarcolemmal Na(+)-Ca(2+) exchange activity. METHODS AND RESULTS: Isolated rat hearts were perfused with a medium containing xanthine plus xanthine oxidase for different times, and changes in contractile force as well as sarcolemmal Na(+)-(2+) exchange activity were monitored. Perfusion of the heart with xanthine plus xanthine oxidase resulted in a transient increase followed by a marked decrease in contractile activity; the resting tension was markedly increased. The xanthine plus xanthine oxidase-induced depression in developed tension, rate of contraction, and rate of relaxation, except the transient increase in contractile activity, was prevented by the addition of catalase, but not by superoxide dismutase, in the perfusion medium. A time-dependent depression in sarcolemmal Na(+)-Ca(2+) was also evident upon perfusing the heart with xanthine plus xanthine oxidase. This depression in Na(+)-dependent Ca(2+) uptake was associated with a decrease in the maximal velocity of reaction without any changes in the affinity of Na(+)-Ca(2+) exchanger for Ca(2+). The presence of catalase, unlike superoxide dismutase, prevented the decrease in sarcolemmal Na(+)-Ca(2+) exchange activity in hearts perfused with xanthine plus xanthine oxidase. CONCLUSIONS: The results support the view that a depression in the sarcolemmal Na(+)-Ca(2+) exchange activity may contribute to the occurrence of intracellular Ca(2+) overload and subsequent decrease in contractile activity. Furthermore, these actions of xanthine plus xanthine oxidase in the whole heart appear to be a consequence of H(2)O(2) production rather than the generation of superoxide radicals.

Effect of vitamin E supplementation on orthodontic tooth movement in Wistar rats

Background: Tooth movement induced by the application of orthodontic force is facilitated by bone remodelling cells and chemical mediators. Vitamin E has anti-inflammatory properties, which helps in suppressing the damaging effects of oxygen free radicals in cells during bone formation. This study aimed to evaluate the effect of vitamin E supplementation on orthodontic tooth movement in Wistar rats. Methods: Wistar rats (n=56) were divided into two groups. Group 1 served as the control groups, while group 2 was given vitamin E for 14 days before application of orthodontic force. Each group was divided into four subgroups (n=7), corresponding to the number of days orthodontic force lasted, i.e. 0, 1, 3, 7 days. At each of these four time points, distance measurements and quantity of osteoblasts-osteoclasts were measured in each rat. Results: Tooth movement distance was increased for group 2 than group 1 for all time intervals, but this difference was only statistically different on day 3 (p=0.001). For both groups, tooth movement was significantly different between each time interval in each group (p=0.041). The mean number of osteoblast cells was increased for group 2 compared to group 1 for all time intervals (p<0.05), but was not significant different between time intervals (p=0.897). The number of osteoclasts was not significantly different between groups, but it was statistically different between time intervals (p=0.004). Conclusion: Present outcomes demonstrate that vitamin E contributes to faster tooth movement compared to control group. It also stimulates more bone formation without reducing the bone resorption.

Analysis of free radical production capacity in mouse faeces and its possible application in evaluating the intestinal environment: a pilot study

Complex interplay between the intestinal environment and the host has attracted considerable attention and has been well studied with respect to the gut microbiome and metabolome. Oxygen free radicals such as superoxide and the hydroxyl radical (•OH) are generated during normal cellular metabolism. They are toxic to both eukaryotic and prokaryotic cells and might thus affect intestinal homeostasis. However, the effect of oxygen free radicals on the intestinal environment has not been widely studied. Herein, we applied electron spin resonance spectroscopy with spin trapping reagents to evaluate oxygen free radical production capacity in the intestinal lumen and the faeces of mice. •OH was generated in faeces and lumens of the small and large intestines. There were no remarkable differences in •OH levels between faeces and the large intestine, suggesting that faeces can be used as alternative samples to estimate the •OH production capacity in the colonic contents. We then compared free radical levels in faecal samples among five different mouse strains (ddY, ICR, C57BL/6, C3H/HeJ, and BALB/c) and found that strain ddY had considerably higher levels than the other four strains. In addition, strain ddY was more susceptible to dextran sulphate sodium-induced colitis. These differences were possibly related to the relative abundance of the gut bacterial group Candidatus Arthromitus, which is known to modulate the host immune response. From these results, we suggest that the production capacity of oxygen free radicals in mouse faeces is associated with intestinal homeostasis.

Prevention of the harmful effects of free oxygen radicals by using N-acetylcysteine in testicular torsion

Testicular torsion is a urological emergency both in childhood and in adult life. Many studies on experimental testicular torsion have demonstrated biochemical and pathological ischemia-reperfusion injury and the efficacy of some drugs have been investigated to prevent this damage. N-acetylcysteine (NAC) promotes glutathione synthesis and acts as a glutathione precursor because of the fact that it increases the glutathione-reductase activity by transporting sulfhydryl groups. In this experimental study, the authors aimed to investigate the effectiveness of NAC in preventing ischemia-reperfusion injury following testicular torsion and detorsion. For this experimental study, 36 albino Wistar-male rats were used. The rats were randomly divided into 4 groups: sham (n=8), ischemia-reperfusion(n=8), ischemia-NAC -reperfusion (n=10), and ischemia-NAC-reperfusion-NAC(n=10) groups. Two hours of torsion and 4h of detorsion were created in the left testis. After 4h of detorsion, the rats were sacrificed. Each tissue was divided into two sections for biochemical and pathological examinations. There was a statistically significant difference between the study groups in terms of the total-sulfhydryl level, nitric oxide level, and the malondialdehyde values. Histopathological examination revealed that NAC was effective in preventing reperfusion injury in the testisbut ineffective in preventing the reduction in the spermatid count. The results of this experimental study support that NAC can histopathologically maintain the structure of seminiferous tubules against ischemis reperfusion injury and prevent damage to the germinative cells. However, it was unable to prevent the reduction in spermatid count. There was no significant difference in the prevention of ischemia-reperfusion injury between NAC administration during the first hour of ischemia and NAC administration during reperfusion. Although NAC can prevent tissue damage from ischemia reperfusion injury, it is not effective against the reduction in the spermatid count. N-acetylcysteine may be biochemically effective in preventing ischemia-reperfusion injury after testicular torsion and detorsion. NAC is a readily available and easy to use agent that can be used during testicular ischemia.

Pathophysiological Effect of Oxygen Free Radicals on Mobility and DNA Integrity of Human Seminal Spermatozoa

Pathophysiological Effect of Oxygen Free Radicals on Mobility and DNA Integrity of Human Seminal Spermatozoa

Effect of free oxygen radical anions and free electrons in a Ca12Al14O33 cement structure on its optical, electronic and antibacterial properties

The aim of this work was to investigate the effect of free oxygen radicals and free electrons in a Ca12Al14O33 (C12A7) cement structure on the optical, electronic and antibacterial activity of this material. Ca12Al14O33 was successfully fabricated via rapid heating to high temperatures by high frequency electromagnetic induction. Ca12Al14O33 cement samples were characterized using XRD and UV-Vis-DRS spectroscopy. The morphology and chemical composition of the samples were also investigated using SEM and EDS techniques. The presence of free oxygen radicals (O2−ions) in the insulating structure of Ca12Al14O33 was confirmed using Raman spectroscopy showing a spectrum peak at 1067 cm−1. The excitation of free electrons in the Ca12Al14O33 cement was indicated by UV-Vis absorption spectra at 2.8 eV and an optical energy gap of 3.5 eV, which is consistent with the first-principles calculations for the band energy level. The effects of free oxygen radicals and free electrons in the Ca12Al14O33 structure as antibacterial agents against Escherichia Coli (E. coli) and Staphylococcus Aureus (S. aureus) were investigated using an agar disk-diffusion method. The presence of O2− anions as a reactive oxygen species (ROS) at the surface of Ca12Al14O33 caused inhibition of E. coli and S. aureus cells. The free electrons in the conducting C12A7 reacted with O2 gas to produce ROS, specifically super oxides (O2−), superoxide radicals (O2•-), hydroxyl radicals (OH•) and hydrogen peroxide (H2O2), which exhibited antibacterial properties. Both mechanisms were active against bacteria without effects from nano-particle sized materials and photocatalytic activity. The experimental results showed that the production of ROS from free electrons was greater than that of the free O2− anions in the structure of Ca12Al14O33. The antibacterial actions for insulating and conducting Ca12Al14O33 were different for E. coli and S. aureus. Thus, Ca12Al14O33 cement has antibacterial properties that do not require the presence of nano-particle sizes materials or photocatalysis.

Ca2+-Dependent Mitochondrial Permeability Transition Pore Opening in Kidney is Substrate Dependent

Oxidative stress within the kidney is associated with disease states including hypertension, renal diseases. The metabolic functions of the mammalian kidneys result in consumption of nearly 20% of total oxygen utilization. There is limited information regarding the effects of oxygen free radicals upon kidney mitochondrial functions. Not only mitochondria oxidize numerous metabolic substrates but also play a key role in maintaining cellular Ca2+ homeostasis. Failure of cellular Ca2+ homeostasis and excessive mitochondrial Ca2+ (mCa2+) lead to opening of a mitochondrial permeability transition pore (mPTP), which is associated with loss of IMM potential and uncoupling of oxidative phosphorylation. We investigated whether mitochondrial metabolic substrates have a differential impact on the Ca2+-induced mPTP opening in the kidney, which plays a critical role in hypertension. For this purpose, mitochondria isolated from Sprague Dawley (SD) rat kidney outer medulla (OM) were energized using mechanistically distinct substrate combinations, Pyruvate+Malate, Glutamate+Malate(GM), Succinate+Rotenone, Succinate, α-KetoGlutarate+Malate, or PalmitoylCarnitine+Malate. Fluorescence-based analysis using Ca2+ indicator Fura-4F assessed the functional consequences of Ca2+-induced mPTP opening. Results show that in the presence of GM, mitochondria can tolerate significantly greater mCa2+ loads as compared to that in the presence of other substrates. Succinate+Rotenone addition significantly delayed mPTP opening over controls (succinate alone). A pore inhibitor CyclosporinA(CsA) and Na+/Ca2+exchanger inhibitor(CGP) were used with all substrates for comparisons. The present study reports variations in mitochondrial substrates sensitivity to Ca2+-induced mPTP opening and that the metabolic fluxes determine the mitochondrial functional responses to mCa2+ overload. The results underscore the effects of various mitochondrial substrates and their electron flux in regulating mPTP opening, which is a determinant of cell death in many diseases. These data are important in order to understand the different pathways/proteins involved in mPTP opening to identify effective interventions to prevent/limit it.

Oxidative Status in Patients with Benign Paroxysmal Positional Vertigo.

Benign paroxysmal positional vertigo (BPPV) is the most frequent peripheral vestibular disorder and is particularly seen among older patients suffering from vertigo. The brief vertigo attacks in and imbalance symptoms of BPPV are caused by freely floating otoconia within the semicircular canals. The aim of this prospective study was to evaluate the role of oxidative stress, using native thiol/disulfide (SH/SS) homeostasis as a novel indicator, in the etiology of BPPV. The 62 participants in the study included 31 patients with BPPV and, as the control group, 31 healthy individuals without any cochleovestibular disorders. Patients with BPPV initially had significantly lower native SH levels and significantly lower SH/total thiol (TT) ratios, as well as significantly higher SS/SH and SS/TT ratios, than the healthy controls. After successful treatment of their vertigo, which was confirmed based on the results obtained from the second blood sample, patients with BPPV still had lower SH levels and SH/TT ratios and significantly higher SS/SH and SS/TT ratios than the healthy controls. Our results suggest a role of oxidative stress in the development of BPPV, through both calcium metabolism and the direct toxic effects of free oxygen radicals, including the triggering of apoptosis.

The effect of pycnogenol on lymphatic nodes and adhesion during in a peritoneal adhesion model in rats.

To investigate the effects of pycnogenol on peritoneal adhesions and additionally to investigate the immunohistochemical effects of free oxygen radicals and reactive lymph nodes detected in the adhesive tissue that was sampled surrounding the cecum on intra-abdominal adhesions. Twenty-seven Wistar Albino rats were divided into three groups. In group 1 (sham), laparotomy was performed and stitched up. In group 2 (control), after laparotomy was performed, punctate hemorrhage was induced by cecal abrasion in the cecum and each rat was intraperitoneally administered 2 cc of saline. In group 3 (experimental), after laparotomy was performed, punctate hemorrhage was induced by cecal abrasion in the cecum and each rat was intraperitoneally administered a sterile Pycnogenol derivative. The rats in all groups were re-laparotomized on postoperative day 7; samples were obtained from the peritoneal tissue surrounding the cecum, and the rats were sacrificed. In group 3, there was a statistically significant difference in terms of inflammation, lymph node size, and free oxygen radicals; these parameters tended to increase. In terms of fibrosis evaluated using H&E and MT, there was no significant difference between groups 2 and 3. No positive outcomes indicating that pycnogenol reduces intra-abdominal adhesions were obtained. However, it caused severe inflammation in the tissue. Moreover, a significant increase in lymph node size was detected secondary to inflammation. Additionally, in immunohistochemical analyses conducted to detect oxidative stress, pycnogenol increased the production of free oxygen radicals in the tissue.

Green tea improves rat sperm quality and reduced cadmium chloride damage effect in spermatogenesis cycle.

Introduction: Testicular tissue is part of the reproductive system that some mineral compounds such as cadmium chloride (CdCl2) destroy. Green tea (Camellia sinensis) extract can reduce the tissue damage caused by toxins due to its antioxidant properties. The aim of this study was to evaluate the effect of green tea extract on sperm quality in cadmium chloride toxicity.Materials and Methods: In the present study, male Wistar rats were allotted randomly into four groups, namely control group (C), CdCl2 (1.5mg/kg), GT 1.5% (w/v) and in combinationCdCl2+GT groups. CdCl2 was injected intraperitoneally (1.5 mg /kg) whereas the green tea extract was administrated orally. At 13, 25 and 49 days after treatment, the rats were euthanized and the reproductive organs (testes, epididymis) were excised and used for sperm analysis and histo-morphometric examinations.Results: The mean of the diameter of seminiferous tubes, the number of spermatogonia, Sertoli, Leydig cells and thickness of the germinal layer in the testis were significantly increased (P<0.05) in all groups compared to the CdCl2 group (P<0.05). Sperm motility, sperm count and testosterone were significantly decreased in the CdCl2 group compared to all groups of treatment (p<0.05). The mean of MDA was significantly increased in the CdCl2 group compared to other groups (p<0.05).Conclusion: Green tea has an antioxidant effect that reduces the effects of free oxygen radicals produced from toxins such as cadmium chloride. In addition, it could decrease lipid peroxidation of the cell membrane and ultimately prevent the destruction of tissues in the long run.

Telomere Length in Transfusion Dependent Thalassemia Patients

BACKGROUNDTransfusion dependent thalassemia (TDT) patients is a group of thalassemia patients who require regular blood transfusion. Red blood cell transfusion and increased intestinal iron absorption leads to iron overload. The cellular damage associated with iron overload is mainly mediated by the state of oxidative stress and the effect of free oxygen radicals on various cell components. Telomeres are terminal protein-DNA complexes that stabilize chromosome and prevent DNA from double-stranded breaks. Chronic oxidative stress from iron overload and ineffective erythropoiesis in thalassemia may lead to shortening of telomere length.METHODWe conducted a cross-sectional study in TDT patients aged more than 18 years old who attended the adult hematology clinic at Maharaj Nakorn Chiang Mai hospital, Chiang Mai University, Thailand from 1 January 2016 to 30 April 2016. TDT was defined as thalassemia who requiring a red cell transfusion at least 3 times per year, included both beta-thalassemia and alpha-thalassemia patients. Telomere length was measured by real-time quantitative PCR and compared with matched healthy controls by age and sex. We used Pearson’s correlation coefficient to test whether telomere length was associated with any factors. The threshold for statistical significance for all comparisons was chosen as P <0.05.RESULTThirty TDT patients and 30 matched healthy control were included in this study. For TDT group, there were 19 female patients (63.3%). The median age was 29.2 (18-48) years. Baseline hemoglobin pre-transfusion 6.4 g/dL (5.3-7.4). Of these, there were 18 beta-thalassemia/Hb E disease (60%) who was the majority population. There were 11 beta-thalassemia major patients (36.4%) and 1 HbH with Constant spring patient (3.3%). The median telomeric terminal restriction fragment (TRF) length of TDT thalassemia group was 5.76 (4.94-7.13) kb. The median TRF length of control group was 6.79 (5.52-9.02) kb. TDT patients had significant shorter TRF length compared to control group (age and sex match), (p<0.0001). Telomere shortening in TDT thalassemia is aging-dependent process. The Pearson’s coefficient showed the negative correlation between TRF length and age (Pearson’s coefficient = 0.176), (p=0.021). There was no correlation of telomere length with other factors such as sex, hemoglobin level, transfusion requirement.CONCLUSIONTDT patients had shorter telomere length compared to control group. Telomere shortening in TDT thalassemia is aging-dependent process. Chronic oxidative stress from iron overload and ineffective erythropoiesis in thalassemia may play the significant role in this accelerated telomere shortening process. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Do copper and zinc levels predict metabolic syndrome and metabolic syndrome's parameters as hs-CRP does?

Being a significant factor indicative of inflammation, hýgh sensitive C reactive protein (hs-CRP) is also predictive for atherosclerosis. It is acknowledged that the efficacy of antioxidant defense mechanism is reduced by the changes in trace element levels. These changes also increase the negative effects of free oxygen radicals on cell integrity. It is known that hs-CRP is a marker in predicting metabolic syndrome (MS) and its parameters. In this study we aim to find some other markers and compare the relation of Cu and Zn levels with MS and MS parameters.410 patients (90 men and 320 women) were included in this study. The measurement of waist and hip circumferences are performed. Fasting plasma glucose, postprandial plasma glucose, insulin, copper, zinc, lipid profile, hsCRP levels were examined. All the analyses were done according to diagnosis criteria of NCEP-ATP III. BMI, HDL and Cu levels were significantly higher in women when compared to men (P < 0.001). As hsCRP does, blood copper levels were found to predict MS and MS parameters. However, it is different from each other in that copper levels predicted different MS parameters at different sensitivity and specificity. We also observed that there was a more significant correlation between TG level, blood pressure and Cu, compared to hsCRP. When all these results are taken into consideration, Cu can be thought as an alternatýve marker in predicting MS and MS parameters. Being influenced less than CRP by the inflammatory events, Cu is a beter predictor for MS and atherosclerosis.

Erratum to: Effect of oxygen free radicals and nitric oxide on apoptosis of immune organ induced by selenium deficiency in chickens

Erratum to: Effect of oxygen free radicals and nitric oxide on apoptosis of immune organ induced by selenium deficiency in chickens

Effect of oxygen free radicals and nitric oxide on apoptosis of immune organ induced by selenium deficiency in chickens

Selenium is an essential element with antioxidant roles in immune regulation, but there is little understanding of how Se acts in apoptosis in the immune organs of birds. The aim of study was to evaluate the influence of Se deficiency on oxygen free radicals, NO and apoptosis in immune organ of chickens. 160 1-day-old chickens were randomly assigned to two groups of 80 each and were fed on a low-Se diet (0.032 mg/kg Se) or a control diet (0.282 mg/kg Se), respectively. OFR production in blood was determined on days 30, 45, 60 and 75, respectively. The iNOS-NO system activity in immune organ (thymus, spleen, bursa of fabricius) was identified by NO content and NOS activity assay on days 30, 45, 60 and 75, respectively. Apoptosis was measured by DNA ladder analysis, ultrastructural observations, TdT-mediated dUTP nick end labeling TUNEL assay and flow cytometric analysis of apoptotic DNA. The transcription of factor-associated suicide, caspase-3 mRNA was tested by fluorescence quantitative PCR. The results showed that OFR production, NO and inducible NO synthases (iNOS) activity in the low-Se group were significantly increased (p < 0.05) than in the control group. In addition, apoptosis was observed in chicken immune organ in the low-Se group. The degree and the number of apoptotic cells rose in a time-dependent manner. The expression of Fas and caspase-3 mRNA increased (p < 0.05) than in the control group. It indicated that the oxidative stress and NO played a causative role in the apoptosis of immune tissues induced by selenium deficiency.

The role of allopurinol's timing in the ischemia reperfusion injury of small intestine.

Introduction:Allopurinol acts protectively in the ischemia reperfusion injury of the small intestine. The aim of this experimental study is to define the ideal time of administration of allopurinol, in experimental models of ischemia/reperfusion.Materials and Methods:We used 46 rabbits that were divided into four groups. Group A was the control. In Group B allopurinol was administered 10 min before ischemia and in Group C 2 min before reperfusion. In Group D, allopurinol was administered before ischemia and before reperfusion in half doses. Blood samples were collected at three different moments: (t1) prior to ischemia, (t2) prior to reperfusion, and (t3) after the end of the reperfusion, in order to determine superoxide dismutase (SOD) and neopterin values. Specimens of the intestine were obtained for histological analysis and determination of malondialdehyde (MDA).Results:In Group A, mucosal lesions were more extensive compared to those of the other three groups. Similarly, MDA, SOD and neopterin values were significantly higher. On the contrary, Group D showed the mildest mucosal lesions, as well as the lowest MDA, SOD and neopterin values. Finally, the lesions and the above mentioned values were bigger in Group C than in Group D.Conclusions:The administration of allopurinol attenuates the production and damage effect of free oxygen radicals during ischemia reperfusion of the small intestine, thus protecting the intestinal mucosa. Its maximum beneficial action is achieved when administered both before ischemia and before reperfusion of the small intestine.