The effects of diazinon on lipid peroxidation and antioxidant enzymes in erythrocytes in vitro

Diazinon is one of the most widely used organophosphate insecticides (OPI) in agriculture and public health programs. The aim of this study was to investigate how an OPI, diazinon, affects lipid peroxidation (LPO) and the antioxidant defense system in vitro. For this purpose, two experiments were carried out. In experiment 1, the effects of various concentrations of diazinon on LPO and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) in erythrocytes were studied. Each diazinon concentration was incubated with a previously prepared erythrocyte samples at +4°C for 0, 60 and 180 min. After incubation, the malondialdehyde (MDA) levels and the activities of SOD, GSH-Px and CAT were determined. In experiment 2, in order to determine the direct effect of diazinon on the activities of SOD, GSH-Px and CAT, the erythrocytes were haemolysed and incubated with the various concentrations of diazinon at +4°C for 0, 60 and 180 min. In experiment 1, MDA levels and the activities of SOD and GSH-Px increased with increasing diazinon concentration and incubation period, but CAT activity remained unchanged. In experiment 2, SOD activity was significantly decreased, and GSH-Px activity was significantly increased. From these results, it can be concluded that in vitro administration of diazinon results in the induction of erythrocyte LPO and changes the activities of antioxidant enzymes, suggesting that reactive oxygen species may be involved in the toxic effects of diazinon.

Cardiotoxicity in rats induced by methidathion and ameliorating effect of vitamins E and C

We have examined the effect of subchronic methidathion (MD) administration on heart damage, and have evaluated possible ameliorating effects of a combination of vitamins E and C against MD toxicity. The experimental groups were: control group, rats treated with 5 mg/kg MD and rats treated with 5 mg/kg body weight MD plus vitamin E and vitamin C (MD+Vit). The groups were given MD by gavage 5 days a week for four weeks at a dose level of 5 mg/kg/day (MD and MD+Vit) by using corn oil as the vehicle. Vitamin E and vitamin C were injected at doses of 50 mg/kg i.m. and 20 mg/kg i.p., respectively, after the treatment with MD in the MD+Vit group. The levels of malondialdehyde (MDA) were determined in the heart tissue, and the levels of cardiac troponin I (TnI) in serum. An autoanalyser was used to determine the serum activities of cholinesterase (ChE). Histopathological examination was carried out in the heart tissue. MDA significantly increased in the MD group as compared to controls (P <0.01). When MD was given concurrently with vitamins E and C, the increase in MDA was significantly less (P <0.01). ChE activity significantly decreased in the MD group as compared to controls (P <-0.01). When MD was given concurrently with vitamins E and C, the decrease in ChE activity was significantly higher (P <-0.05). The serum TnI levels significantly increased in the MD group as compared to controls (P <-0.01). When MD was given concurrently with vitamins E and C, the increase in the serum TnI was significantly less (P <-0.01). MD caused the diffuse loss of striation and myocytolysis of the cardiomyocytes, whereas the combination of vitamins E and C caused a significant decrease in these effects of MD. In conclusion, subchronic MD administration caused heart damage and, in addition, treatment with a combination of vitamins E and C after the administration of MD reduced heart damage caused by MD.

No effects of 900 MHz and 1800 MHz electromagnetic field emitted from cellular phone on nocturnal serum melatonin levels in rats

In this study, the effects of exposure to a 900 MHz and 1800 MHz electromagnetic field (EMF) on serum nocturnal melatonin levels of adult male Sprague-Dawley rats were studied. Thirty rats were used in three independent groups, 10 of which were exposed to 900 MHz, 10 of which were exposed to 1800 MHz and 10 of which were sham-exposed (control). The exposures were performed 30 min/day, for five days/week for four weeks to 900 MHz or 1800 MHz EMF. Control animals were kept under the same environmental conditions as the study groups except with no EMF exposure. The concentration of nocturnal melatonin in the rat serum was measured by using a radioimmunoassay method. There were no statistically significant differences in serum melatonin concentrations between the 900 MHz EMF group and the sham-exposed group (P-0.05). The values at 12:00 pm were 39.119 / 6.5 pg/mL in the sham-exposed group and 34.979 / 5.1 pg/mL in the 900 MHz EMF-exposed group. Also, there were no statistically significant differences in serum melatonin concentrations between the sham-exposed group and the 1800 MHz EMF-exposed group (P-0.05). The values at 12:00 pm were 39.119 / 6.5 pg/mL in the sham-exposed group and 37.969 / 7.4 pg/mL in the exposed group. These results indicate that mobile phones, emitting 900 and 1800 MHz EMF, have no effect on nocturnal serum melatonin levels in rats.

Greater Efficiency Observed 12 Months Post-Implementation of an Automatic Tube Sorting and Registration System in a Core Laboratory

BACKGROUND

Sample classification and registration have been recognized as important and time-consuming processes in laboratories. There is increasing pressure on laboratories to automate processes due to intense workload and reduce manual procedures and errors. The aim of the present study was to evaluate the positive effects of an automatic tube registration and sorting system on specimen processing.

METHODS

An automatic tube registration and sorting system (HCTS2000 MK2, m-u-t AG, Wedel, Germany) was evaluated. Turnaround time (TAT), rate of sample rejection and unrealized tests were examined 12 months pre- and post-implementation of the automatic tube sorting and registration system.

RESULTS

The mean TAT of routine chemistry immunoassay, complete blood cell count (CBC) and coagulation samples were significantly improved (P<0.001). The number of rejected samples and unrealized tests was insignificantly decreased post-implementation of the system (0.4% to 0.2% and 4.5% to 1.4%, respectively) (P>0.05).

CONCLUSIONS

By reducing delays and errors in the preanalytical processing and sorting of samples, significant improvements in specimen processing were observed after implementation of the system. These results suggest that an automatic tube registration and sorting system may also be used to improve specimen processing in a higher-volume core laboratory.

The importance of the incidental thyroid gland uptake during Tc-99m MIBI myocardial perfusion scintigraphy

OBJECTIVE

The purpose of study was to investigate whether incidental thyroid gland uptake had an important during Tc-99m sestamibi (MIBI) myocardial perfusion scintigraphy (SPECT).

PATIENTS AND METHODS

In the presented study, 968 consecutive patients were evaluated for the presence or absence of thyroid gland uptake in the raw data of the Tc-99m MIBI SPECT. All of the patients had thyroid gland uptake of the Tc-99m MIBI underwent laboratory evaluation of thyroid function, ultrasonographic imaging, and hystopathological examination.

RESULTS

The thyroid gland uptake was detected in 14 of 968 (1.4%) consecutive patients during the evaluation of raw images of Tc-99m MIBI SPECT studies. Among these 14 patients, 4 had subacute thyroiditis, 7 multinodular goiter, 3 Graves disease by ultrasonographic imaging and hystopathological examination. TSH levels of all of these patients were < 0.01 U/ml.

CONCLUSIONS

Tc-99m MIBI uptake by thyroid gland has been explained with associated clinical thyrotoxicosis. Although the primary goal of myocardial perfusion imaging is the evaluation of myocardial perfusion, the interpretation of myocardial perfusion imaging should not be limited to the heart. Because, it is possible to observe extracardiac radioactivity accumulation, which may then lead to the diagnosis of a noncardiac disease during this detailed examination.

Decreased serum vitamin D levels are associated with diabetic peripheral neuropathy in a rural area of Turkey

Data examining the association between vitamin D and diabetic peripheral neuropathy are limited. This study investigated the serum levels of vitamin D, vitamin D-binding protein (VDBP), and vitamin D receptor (VDR) in diabetics in the Yozgat region of Turkey, and assessed their relationships with diabetic peripheral neuropathy. 69 diabetic patients and 49 age- and sex-matched control subjects were enrolled in this clinical prospective study. All the diabetics underwent conventional sensory and motor nerve conduction studies, and diabetic peripheral neuropathy was confirmed or ruled out according to the electromyography findings and Douleur Neuropathique 4 questions. Serum vitamin D, VDBP and VDR levels were measured using commercial enzyme-linked immunosorbent assay kits. The serum vitamin D levels (p = 0.001) were significantly lower, while the VDR levels (p = 0.003) were higher, in diabetics than in controls. The serum VDBP levels were similar in both groups (p > 0.05). The serum vitamin D levels were significantly lower in diabetics with diabetic peripheral neuropathy than in those without (p = 0.032), whereas the serum VDBP and VDR levels were similar in these two groups (p > 0.05). The lower serum vitamin D levels in diabetics, especially in those with peripheral neuropathy, may suggest a neurotrophic effect of vitamin D.

Serum levels of vitamin D, vitamin D-binding protein and vitamin D receptor in migraine patients from central Anatolia region

OBJECTIVES

Inflammation is proposed to be involved in the pathogenesis of both vitamin D deficiency and migraine. However, the data examining the relation of vitamin D with migraine are limited. We aimed to investigate the serum levels of vitamin D, vitamin D-binding protein (VDBP) and vitamin D receptor (VDR) in combination, in migraine patients from central Anatolia region.

METHODS

Fifty-two newly diagnosed migraine patients and age- and sex-matched 49 control subjects were enrolled in this cross-sectional prospective study. Migraine diagnosis was settled according to the International Classification of Headache Disorders-II diagnostic criteria. Serum samples were analysed for the measurement of vitamin D, VDBP and VDR levels by using commercial enzyme-linked immuno sorbent assay kits.

RESULTS

Serum vitamin D and VDR levels were found to be significantly lower in migraine patients than in controls (p = 0.012 and p = 0.038, respectively); whereas serum VDBP levels were similar between the groups (p > 0.05). There was no correlation between serum vitamin D, VDBP and VDR levels and headache characteristics including aura, attack severity, frequency and duration, and disease duration (p > 0.05). In terms of headache characteristics, no significant difference between migraineurs with vitamin D values < 25 and ≥ 25 ng/ml was observed (p > 0.05).

CONCLUSIONS

The present findings may suggest that decreased serum vitamin D levels were associated with migraine.

The effect of adenotonsilectomy on ghrelin, leptin, IGF-1 levels and growth parameters in children with adenotonsillar hypertrophy

AIM

The purpose of this study was to search for the effects of adenotonsillectomy (A&T) on height, weight, and body mass index (BMI), as well as changes in ghrelin, leptin, and insulin-like growth factor 1 (IGF-1) levels in children with adenotonsillar hypertrophy (ATH)-related sleep-disordered breathing (SDB).

METHODS

A study cohort of 39 children clinically diagnosed with ATH-related SDB was included in this study. Twenty-three healthy children were included as controls. Height and weight standard deviation scores (SDS) and ghrelin, leptin, and IGF-1 levels of the controls were determined once; in the study group, they were determined preoperatively and in the third month postoperatively.

RESULTS

Preoperative IGF-1 (ng/mL) and ghrelin (pg/mL) levels were significantly higher in the patients than in the controls (322.51±113.10 vs. 256.96±176.73, p<0.05 and 106.08±9.75 vs. 80.11±28.50, p<0.001, respectively). The preoperative height and weight SDS values of the patients were lower than those of the controls (-0.67±1.36 vs. 0.13±1.13, p<0.05 and -0.38±1.35 vs. -0.20±1.29, respectively). The patients' postoperative height and weight SDS values were significantly higher than their preoperative values (-0.05±1.08 vs. -0.67±1.36, p<0.0001 and 0.00±1.28 vs. -0.38±1.35, p<0.0001, respectively). The mean postoperative IGF-1 levels also were significantly higher than preoperative levels (386.05±130.06 vs. 322.51±113.10, p<0.05, respectively).

CONCLUSION

Plasma IGF-1 levels are lower in malnourished children, and plasma ghrelin levels are decreased after acute oral food intake and are increased in cachexia and fasting. Therefore, increased serum IGF-1 levels, height and weight SDS values, and decreased ghrelin levels detected postoperatively are useful parameters that help to monitor the development of children with adequate oral intakes.

Evaluation of Cardiac Markers in Children Undergoing Hematopoietic Stem Cell Transplantation

BACKGROUND

Early life-threatening cardiotoxicity and cardiac death have been reported after hematopoietic stem cell transplantation (HSCT). The purpose of the current study was to evaluate cardiac toxicity of conventional chemotherapy followed by HSCT with cardiac markers: heart-type fatty acid binding protein (H-FABP), glycogen phosphorylase BB (GPBB), high sensitive C reactive protein (hsCRP) cardiac troponin I, (cTnI), creatine kinase MB (CK-MB mass) and myoglobin.

METHODS

A total of 20 children who underwent HSCT for malignant and non-malignant diseases were included in this study. Blood samples were collected from all patients in 0th, 7th and 21st day for evaluating these cardiac biomarkers. The patients' echocardiography was assessment before and after one-month of HSCT.

RESULTS

Serum 21st H-FABP level was significantly higher when compared with the 0th day H-FABP level (P < 0.05) . 7th day hsCRP level was significantly higher than 0th and 21st day levels (P < 0.05). Interestingly, 7th day GPBB level was significantly lower than 0th and 21st day levels (P < 0.05). Myoglobin, CK-MB mass and cTnI biomarkers remained within the reference range in all patients.

CONCLUSIONS

This study showed that H-FABP and hsCRP both seem to be promising markers for evaluation of cardiotoxicity in HSCT process and probably superior to GPBB, cTnI, CK-MB mass and myoglobin.

Effects of long-term fasting on female hormone levels: Ramadan model

BACKGROUND

Ramadan fasting is a special model of hunger and particularly affects metabolic processes, including carbohydrate and lipid levels. Endocrine changes induced by Ramadan fasting are not well known.

OBJECTIVE

The aim of this article was to evaluate the changes in hormone levels in women before and after the special Muslim fasting period of Ramadan.

MATERIALS AND METHODS

This study was performed in 30 healthy women in Obstetrics and Gynecology department during the Ramadan month of2011. Patients during and after the first menstrual period had menstrual cycles fasting blood samples taken on the same days. Luteinizing hormone (LH), follicle stimulating hormone (FSH), estradiol (E2), testosterone, and prolactin (PRL) levels were determined.

RESULTS

Before and during fasting LH, FSH, E2, testosterone and PRL levels were not statistically different.

CONCLUSION

Despite the limited available studies on these subjects in women, effect of Ramadan fasting on hormone levels were found to be within the normal limits.

The effects of tramadol infiltration on wound healing in rats

PURPOSE

Infiltration of a local anesthetic to provide postoperative analgesia is a frequently used method. However the infiltrated agents may have negative effects on wound healing. This study aimed to investigate the effects of tramadol, a weak opioid with a local anesthetic effect, on wound healing.

METHODS

Wistar albino rats were used in the study. Tramadol and saline infiltration was randomly performed on the left and right backs of rats. Following a linear incision, the site was sutured. A follow-up was conducted after seven days, and the tissue samples from both locations were extracted for histopathological examinations (fibrotic index : no fibrosis 0, mild 1, moderate 2, severe 3) and hydroxyproline measurements.

RESULTS

The hydroxyproline level found in the tramadol group was 0.060 +/- 0.04 ng/mg.protein. In the control group the hydroxyproline level was 0.012 +/-0.01 ng/mg.protein (p = 0.01). The fibrotic index levels in the tramadol group were higher than the control group (p < 0.001).

CONCLUSION

It was concluded that tramadol infiltration in a surgical incision site has no adverse effect on wound healing.

Effect of atorvastatin on atherosclerotic plaque formation and platelet activation in hypercholesterolemic rats

We aimed to investigate whether atorvastatin influenced the CD40-CD40L pathway in atherosclerosis formation in rats fed a high cholesterol diet. Thirty-six male Wistar rats were divided among 4 groups as follows: control (C), statin (S), 5% cholesterol fed (HC), and statin-administered hypercholesterolemic (HCS). Serum levels of lipids, soluble CD40L, platelet factor 4, and interleukin-6 were assayed with commercial kits. The number of platelets expressing surface P-selectin, CD40, and CD40L were determined by flow cytometry. Aortas were examined for fatty streaks. In the HC group, we observed a significant increase in serum lipid levels and platelet activation markers compared with the control group. Rats in the HCS group had a significant decrease in lipid levels and downregulation in the number of platelets expressing surface P-selectin, CD40, and CD40L compared with the HC group. We observed decreased fatty streak formations in aortas in HCS rats. A positive correlation was found for platelet activation markers and atherosclerotic fatty streak formations. Regression analysis revealed that the predictor of atherosclerosis was CD40L. Our study suggests that in a rat hypercholesterolemic model, statin treatment may influence the CD40-CD40L dyad, and that this effect is parallelled by a suppression of progression of atherosclerotic plaque formation.

Effects of lisinopril on NMDA receptor subunits 2A and 2B levels in the hippocampus of rats with L-NAME-induced hypertension

Hypertension is major risk factor leading to cerebrovascular pathologies. N-methyl D-aspartate receptors (NMDARs) and renin-angiotensin system are involved in neuronal plasticity, as well as cognitive functions in the hippocampus. In this study, we examined the effects of lisinopril, an ACE inhibitor, on the levels of hippocampal NMDAR subunits; NR2A and NR2B in L-NAME (N(ε)-nitro-L-arginine Methyl Ester)-induced hypertensive rats. In addition, malondialdehyde (MDA) levels were measured as a marker for lipid peroxidation. Compared with the control group, the MDA level was significantly increased after 8 weeks in the L-NAME-treated group. Rats treated with lisinopril and L-NAME plus lisinopril were found to have significantly decreased hippocampal MDA levels. Regarding the hippocampal concentrations of NR2A and NR2B, there were no statistically significant differences between groups. We demonstrated that lisinopril treatment has no direct regulatory effect on the levels of NR2A and NR2B in the rat hippocampus. Our results showed that Lisinopril could act as an antioxidant agent against hypertension-induced oxidative stress in rat hippocampus. The findings support that the use of lisinopril may offer a good alternative in the treatment of hypertension by reducing not only blood pressure but also prevent hypertensive complications in the brain.

Preventive effect of probiotics and α-tocopherol on ethanol-induced gastric mucosal injury in rats

The protective effect of a probiotic mixture of 13 different bacteria and α-tocopherol on 98% ethanol-induced gastric mucosal injury was evaluated. Levels of gastric mucosal pro- and anti-inflammatory cytokines, malondialdehyde, and secretory immunglobulin A were measured. Rats were allocated into four groups: control, ethanol, probiotic, and α-tocopherol. The control and ethanol groups received skim milk for 14 days. Probiotic and α-tocopherol groups were administered probiotic mixture suspended in skim milk and 100 mg/kg α-tocopherol, respectively, by daily gavage for 14 days. On Day 15, gastric lesions were induced by administration of ethanol 98% (1 mL) to all rats except those in the control group. Probiotic, but not α-tocopherol, seemed to inhibit ethanol-induced gastric mucosal tumor necrosis factor-α, interferon-γ, and interleukin-2 production (P > .05). Ethanol caused the elevation of mucosal interleukin-4 level (compared to the control, P < .05). Probiotic pretreatment significantly suppressed the ethanol-induced increase of gastric mucosal interleukin-4 levels. Pretreatment with either probiotic or α-tocopherol inhibited the ethanol-induced increase of mucosal malondialdehyde concentration (P < .01 and P < .05, respectively). Probiotic pretreatment enhanced the gastric mucosal secretory immunoglobulin A concentration (P < .001). In conclusion, probiotic mixture and α-tocopherol reduced ethanol-induced gastric mucosal lipid peroxidation, suggesting that they may be beneficial for gastric lesions induced by lower ethanol concentration.

Calorie restriction modulates hippocampal NMDA receptors in diet-induced obese rats

Calorie restriction (CR) has attracted increased interest since CR enhances lifespan and alters age-related decline in hippocampal-dependent cognitive functions. Obesity is associated with poor neurocognitive outcome including impaired hippocampal synaptic plasticity and cognitive abilities such as learning and memory. N-Methyl-D-aspartate receptors (NMDARs) are linked to hippocampal-dependent learning and memory, which may be stabilized by CR. In the present study, we aimed to establish the effects of CR on NMDARs in CA1 region of hippocampus in obese and non-obese rats. In addition, malondialdehyde (MDA) levels were determined as a marker for lipid peroxidation (LPO) in hippocampus. Four groups were constituted as control group (C, n = 9), obese group (OB, n = 10), obese calorie-restricted group (OCR, n = 9), and non-obese calorie-restricted group (NCR, n = 10). OCR and NCR were fed with a 60% CR diet for 10 weeks. After 10 weeks of CR, the MDA levels significantly decreased in the calorie-restricted groups. Obesity caused significant decreases in NR2A and NR2B subunit expressions in the hippocampus. The hippocampal NR2A and NR2B levels significantly increased in the OCR group compared with the OB group (P < 0.05). In contrast, the hippocampal NR2A and NR2B levels significantly decreased in the NCR group compared with the C group (P < 0.05). Oxidative stress can be prevented by CR, and these data may provide a molecular and cellular mechanism by which CR may regulate NMDAR-mediated response against obesity-induced changes in the hippocampus.

Alterations of plasma magnesium, copper, zinc, iron and selenium concentrations and some related erythrocyte antioxidant enzyme activities in patients with Alzheimer's disease

The aim of the present study is to evaluate the status of plasma essential trace elements magnesium (Mg), copper (Cu), zinc (Zn), iron (Fe) and selenium (Se) concentrations and their some related antioxidant enzyme activities, erythrocyte glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT) activities in patients with Alzheimer's disease (AD). Fifty patients with AD and fifty healthy control subjects were included in this study. Plasma Cu and Zn concentrations by atomic absorption spectrometry (AAS), plasma Mg and Fe concentrations by spectrophotometric methods and plasma Se concentrations by graphite furnace AAS were determined. Erythrocyte GPx, SOD and CAT activities were measured by spectrophotometric methods. Plasma Mg, Cu, Zn, Fe and Se levels and erythrocyte GPx, SOD and CAT activities were found to be significantly lower in patients with AD compared with controls. These results suggest that alterations in essential trace elements and their related enzymes may play a role in the etiopathogenesis of AD. Also, there is a defect in the antioxidant defense system, which may lead to oxidative damage in patients with AD. The changes in antioxidant enzyme activities may be secondary to the alterations in their cofactor concentrations.

Impairment of endothelium-dependent vasorelaxation in cadmium-hypertensive rats

Abnormalities in the production and/or release of relaxing factors from the endothelium have been implicated in the development of hypertension in several animal models. Endothelium-dependent relaxation has been reported to be impaired in thoracic aorta in experimentally induced and genetically hypertensive rats. Present study has extented these observations to thoracic aorta of cadmium-hypertensive rats. The possible role of alterations in oxidant status was also studied. Hypertension was induced by the intraperitoneal administration of 1 mg/kg/day cadmium for 15 days. Mechanical responses produced by acetylcholine (ACh, 10— 9—10—4 M) and sodium nitroprusside (SNP, 10—10—10— 5 M) were studied on phenylephrine-precontracted thoracic aorta rings from control and cadmium-hypertensive rats. Serum nitric oxide (NO) and aortic malondialdehyde (MDA) levels were measured. ACh-induced relaxation was attenuated in aorta from cadmium-hypertensive rats, whereas relaxation responses to SNP did not differ significantly between the groups. Exposure of aortic rings to NG-nitro-L-arginine methyl ester (L-NAME, 10 —4 M) resulted in a significantly greater inhibition of relaxation response to ACh in aortic rings of cadmium-hypertensive rats as compared with control rats. Incubation with L-arginine (L-Arg, 10 —3 M) caused a similar reversal of the inhibition of ACh-induced relaxation by L-NAME in both groups. Serum NO levels were decreased and aortic MDA levels were increased in cadmium-treated rats as compared with control rats. However, the differences between the groups did not reach a statistical significance. These findings suggested that the reduction in endothelium-dependent relaxation may play a role in cadmium-induced hypertension as it was in many other hypertension models.

EFFECTS OF ISCHEMIA-REPERFUSION ON NMDA RECEPTOR SUBUNITS 2A AND 2B LEVEL IN RAT HIPPOCAMPUS

The authors investigated the effects of ischemia and reperfusion on the N-methyl-D-aspartate receptor (NMDAR) subunits 2A and 2B concentration in rat hippocampus. At the protein level, significant increase in the amounts of NMDAR 2A and NMIDAR 2B in the rat hippocampus was observed at 1 h after reperfusion compared with control group. These results suggested that the alteration in hippocampal NMDAR2 subunit concentrations after ischemia-reperfusion might be invovlved in cognitive dysfunction and excitotoxicity.

EFFECTS OF DIETARY LONG CHAIN PUFAs ON HIPPOCAMPAL LIPID PEROXIDATION AND NMDA RECEPTOR SUBUNITS A AND B CONCENTRATION IN STREPTOZOTOCIN-DIABETIC RATS

This study examined the effects of streptozotocin (STZ)-diabetes and dietary long chain polyunsaturated fatty acids (LC-PUFAs) on hippocampal N-methyl-D-aspartate (NMDA) receptor subunit expression and lipid peroxidation. MDA level was significantly increased after 8 weeks of STZ-diabetes. LC-PUFAs administration significantly reduced MDA levels in diabetic rats. NR2A and NR2B protein concentrations were significantly decreased by about 30% in diabetic rats. Dietary LC-PUFAs partially restored NR2A and NR2B in diabetic rats whereas the most significant increase was seen in nondiabetic rats. Consequently, dietary LC-PUFAs can partially restore hippocampal NMDA receptors and decrease lipid peroxidation in diabetes. LC-PUFAs are thus a possible prophylactic means for preventing the cognitive deficiencies of diabetes.

CHLORPYRIFOS INCREASES THE LEVELS OF HIPPOCAMPAL NMDA RECEPTOR SUBUNITS NR2A AND NR2B IN JUVENILE AND ADULT RATS

The present study investigated the effect of chlorpyrifos on NMDA receptor subunits NR2A and NR2B in juvenile and adult rats. Chlorpyrifos was administered with the dose of 40 and 70 mg/kg to juvenile and adult rats, respectively. Chlorpyrifos significantly inhibited the AChE activity in juvenile and adult rats (p < .05). NR2A and NR2B levels significantly increased in juvenile and adult rats by chlorpyrifos application (p < .05). Increased NR2A and NR2B levels may reflect increased glutaminergic activity, consequently neuronal damage. In the case of neuronal damage, learning and memory could be affected negatively even though NR2A and NR2B increased.

Downregulation of TESTIN and its association with cancer history and a tendency toward poor survival in head and neck squamous cell carcinoma

OBJECTIVE

To examine the role of TESTIN as a candidate tumor suppressor gene in head and neck carcinogenesis.

DESIGN

Mutation and messenger RNA (mRNA) expression analyses.

SETTING

Academic research.

PATIENTS

Paired normal and tumor samples were obtained from 38 patients with primary head and neck squamous cell carcinoma.

MAIN OUTCOME MEASURES

Analysis and comparison of TESTIN gene mRNA expression and its relationship to clinicopathologic variables.

RESULTS

Mutation analysis showed a nucleotide and amino acid change in 6 of the 38 tumor samples (16.0%). Semiquantitative mRNA expression analysis of TESTIN revealed a decreased expression in approximately 50% of the tumors compared with their matched normal controls. Interestingly, comparison of clinicopathologic variables to mRNA expression status of TESTIN revealed a significant difference in terms of cancer history (P = .03). Moreover, a higher smoking ratio and a family cancer history were also associated with downregulation of TESTIN, although the difference was not statistically significant (P = .43 and P = .16, respectively). Kaplan-Meier survival analysis demonstrated a worse survival rate among the patients with low TESTIN expression compared with the patients with normal-high TESTIN expression.

CONCLUSIONS

Our findings suggest that inactivation of TESTIN is involved in head and neck carcinogenesis through its downregulation. Further studies in various human cancer tissues using a large sample size and in vitro functional studies as well as clinical comparison research studies would give us a better evaluation of TESTIN's role and its possible future application in molecular diagnosis and treatment of different cancer types, including head and neck squamous cell carcinoma.

Sildenafil citrate as a phosphodiesterase inhibitor has an antioxidant effect in the blood of men

BACKGROUND AND OBJECTIVE

Sildenafil citrate enhances the action of nitric oxide by preventing the hydrolysis of cGMP, and is widely used to treat erectile dysfunction. We investigated the effects of sildenafil citrate administration on lipid peroxidation and antioxidant redox enzymes in blood of healthy men.

METHOD

Thirty healthy male subjects were divided equally into two groups. The first group was used as the control. A single dose of sildenafil citrate was administrated orally to subjects constituting the second group. Blood samples were obtained at 0, 2, 6 and 24 h after intake of the single dose of 100 mg sildenafil citrate or placebo.

RESULTS AND DISCUSSION

The dose of sildenafil citrate resulted in significant increase in the erythrocyte superoxide dismutase and catalase activities at 6 and 24 h. Plasma lipid peroxidation levels decreased slightly. There was no statistical difference in erythrocyte glutathione peroxidase activity between the placebo and sildenafil citrate groups.

CONCLUSION

Treatment of blood with 100 mg sildenafil citrate has protective effects on oxidative stress by inhibiting free radical formation and by supporting antioxidant redox systems.

The role of arginine-nitric oxide pathway in patients with Alzheimer disease

There is a reciprocal regulation of arginase and nitric oxide synthase in L-arginine-metabolizing pathways. There are various evidences of the role of nitric oxide in several neuropsychiatric disorders including Alzheimer's disease. However, there is no study that has investigated the role of arginase as an important part of the arginine regulatory system affecting nitric oxide synthase activity in Alzheimer's disease. This study aims to investigate arginase, manganese (a cofactor of arginase), and total nitrite levels (a metabolite of NO) and their relationship to the arginine-NO pathway in patients with Alzheimer's disease. Arginase activities, Mn, and total nitrite levels were measured in plasma from 47 patients with Alzheimer's disease and 43 healthy control subjects. Plasma arginase activities and manganese were found to be significantly lower and total nitrite level higher in patients with Alzheimer's disease compared with controls. Our results suggest that the arginine-NO pathway is involved in the pathogenesis of Alzheimer's disease.

The effects of 201Tl myocardial perfusion scintigraphy studies on oxidative damage in patients

The aim of this study was to investigate gamma radiation-induced oxidative damage in erythrocytes after 201Tl myocardial perfusion scintigraphy. Twenty patients (8 women and 12 men) who performed 201Tl myocardial perfusion scintigraphy were included in this study. The blood samples were taken from patients just before, 1 hour after and three hours after injection of the radiopharmaceutical. Malondialdehyde (MDA) and antioxidant enzymes such as glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT) levels were measured to evaluate the gamma radiation induced oxidative damage. The enzyme activities of SOD, GPX and CAT were decreased 1 hour after (p = 0.042, p = 0.697 and p = 0.653 respectively) and 3 hours after (p = 0.003, p = 0.573 and p = 0.002 respectively) injection of the radiopharmaceutical. Malondialdehyde levels were increased 1 hour after (p = 0.10) and 3 hours after (p = 0.47) injection of the radiopharmaceutical. In this study, we found that radiation due to 201Tl myocardial perfusion scintigraphy decreased the erythrocyte antioxidant levels and increased MDA levels.

The effects of diazinon on lipid peroxidation and antioxidant enzymes in rat erythrocytes: role of vitamins E and C

Reactive oxygen species caused by organophosphates may be involved in the toxicity of various pesticides. Therefore, in this study, we aimed to investigate the effects of acute exposure to organophosphate insecticide diazinon (DI) and possible ameliorating role of vitamins E and C, with the following parameters: lipid peroxidation (LPO) and the activity of the glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) in rat erythrocytes. The experimental groups were arranged as control group, DI-treated group (DI) and DI + vitamin E + vitamin C-treated group (DI + Vit). DI + Vit groups were treated orally with a single dose of 335 mg/kg DI body weight. Vitamins E and C were injected at doses of 150 mg/kg body weight intramuscular (in) and 200 mg/kg body weight intraperitoneal (ip), respectively, 30 min after the treatment of DI in DI + Vit group. Blood samples were taken 24 h after the DI. The results showed that DI administration caused to increase in LPO and the activities of SOD and GSH-Px enzymes in erythrocytes. Also, the combination of vitamins E and C decreased LPO and the activities of GSH-Px and SOD compared with the DI group. In conclusion, although treating rats with single dose DI increases LPO and antioxidant enzyme activities in erythrocytes, vitamins C and E combination can reduce LPO caused by DI.

Protective effects of vitamins C and E against endometrial damage and oxidative stress in fluoride intoxication

1. Fluoride (F) is an essential trace element that has protective effects against bone mineral loss. However, it becomes toxic at higher doses and induces some adverse effects on a number of physiological functions, including reproduction. The aims of this study were to examine F-induced oxidative stress that promotes production of reactive oxygen species (ROS) and to investigate the role of vitamins C and E against possible F-induced endometrial impairment in rats. 2. Rats were divided into three groups: control, F and F plus vitamins. The F group was given 100 mg/L orally for 60 days. Combined vitamins were also administered orally. Fluoride administration to control rats significantly increased endometrial malondialdehyde (MDA) but decreased superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activities. Endometrial glandular and stromal apoptosis were investigated by DNA nick end-labelling (TUNEL) method on each sample and the mean endometrial apoptotic index (AI) was calculated. 3. Vitamin administration with F treatment caused endometrial MDA to decrease, but SOD, GSH-Px and CAT activities to increase, all to significant levels. Vitamins showed a histopathological protection against F-induced endometrial damage. There was a significant difference in the AI between the groups. Lymphocyte and eosinophil infiltration in stroma in F-treated rats were more than those in the control and F + Vit groups. 4. It can be concluded that oxidative endometrial damage plays an important role in F-induced endometrial toxicity, and the modulation of oxidative stress with vitamins reduces F-induced endometrial damage both at the biochemical and histological levels.

Gadolinium chloride attenuates aortic occlusion-reperfusion-induced myocardial injury in rats

OBJECTIVE

Aortic ischemia and reperfusion periods, which are often associated with infrarenal abdominal aortic cross-clamping and declamping, cause injury in distant organs including the heart. We recently reported that Kupffer cell blockage with gadolinium chloride (GdCl3) attenuates lung injury induced by aortic ischemia-reperfusion (IR). Therefore, we hypothesized that GdCl3 may attenuate myocardial injury induced by aortic IR.

METHODS

The study was carried out in June 2005, in the Laboratory of Experimental Studies of Suleyman Demirel University Medical School, Isparta, Turkey. We studied the effect of GdCl3 on myocardial injury induced by abdominal aortic occlusion-reperfusion in rats by measuring the tissue levels of superoxide dismutase, catalase, malondialdehyde and activity of myeloperoxidase in rat heart specimens. Wistar-Albino rats (8 per group) were randomized into 3 groups. The control group underwent midline laparotomy and dissection of the infrarenal abdominal aorta without occlusion; the aortic IR group underwent laparotomy and clamping of the infrarenal abdominal aorta for 30 minutes followed by 60 minutes of reperfusion; and the GdCl3 + aortic IR group was pretreated with intravenous GdCl3 10 mg/kg 24 hours before the aortic IR.

RESULTS

Aortic IR significantly increased whereas pretreatment with GdCl3 significantly decreased oxygen free radical production, lipid peroxidation and neutrophil activation in the heart tissues of the rats.

CONCLUSION

Our results indicate that Kupffer cell blockage with GdCl3 attenuates the myocardial injury induced by aortic IR. We think that the novel findings of the present study may be a basis for further studies investigating the role of GdCl3 pretreatment in reducing myocardial morbidity and mortality caused by aortic IR during aortic surgery.

The effects of subchronic methidathion toxicity on rat liver: role of antioxidant vitamins C and E

Methidathion (MD) phosphorodithioic acid S-[(5-methoxy-2-oxo-1,3,4-thiadiazol-3(2H)-yl)methyl] O,O-dimethyl ester is the organophosphate insecticide (OPI) most commonly used worldwide in the pest control of crops. Subchronic MD exposure was evaluated for its effects on lipid peroxidation, the serum activities of cholinesterase (ChE), and enzymes concerning liver damage, and the protective effects of combination of vitamins E and C in albino rats. Additionally, the histopathological changes in liver tissue were examined. Experimental groups were as follows: control group; a group treated with 5 mg/kg body weight MD (MD group); and a group treated with 5 mg/kg body wight MD plus vitamin E plus vitamin C (MD+AO group). The MD and MD+AO groups were treated orally with MD on five days a week for 4 weeks. The serum activities of cholinesterase (ChE), alanine transferase (ALT), aspartate amiotransferase (AST), lactate dehydrogenase (LDH), gamma-glutamyltransferase (GGT), alkaline phosphatase (ALP), and the concentration of malondialdehyde (MDA) and liver histopathology were studied. In serum samples, MD significantly increased MDA concentration and ALP, AST, GGT, LDH activities but decreased the ALT and ChE activities. In the MD+AO group, MDA level and ALP, AST, LDH activities were significantly decreased and ChE activity was increased compared to the MD group. Histopathological changes found in liver tissue of rats treated with MD included were infiltration with mononuclear cells in all portal areas, sinusoidal dilatation, and focal microvesicular steatosis and hydropic degenerations in parenchymal tissue. The severity of these lesions was reduced by administration of vitamins. From these results, it can be concluded that subchronic MD causes liver damage, and lipid peroxidation may be a molecular mechanism involved in MD-induced toxicity. Furthermore, the combination of vitamins E and C can reduce the toxic effects of MD on liver tissue of rats.

Melatonin modulates 900 Mhz microwave-induced lipid peroxidation changes in rat brain

Microwaves (MW) from cellular phones may affect biological systems by increasing free radicals, which may enhance lipid peroxidation levels of the brain, thus leading to oxidative damage. Melatonin is synthesized in and secreted by the pineal gland at night and exhibits anti-oxidant properties. Several studies suggest that supplementation with anti-oxidant can influence MW-induced brain damage. The present study was designed to determine the effects of MW on the brain lipid peroxidation system, and the possible protective effects of melatonin on brain degeneration induced by MW. Twenty-eight Sprague-Dawley male rats were randomly divided into three groups as follows: (1) sham-operated control group (N = 8); (2) study 900-MHz MW-exposed group (N = 8); and (3) 900-MHz MW-exposed+melatonin (100 microg/kg sc before daily MW exposure treated group) (N = 10). Cortex brain and hippocampus tissues were removed to study the levels of lipid peroxidation as malonyl dialdehyde. The levels of lipid peroxidation in the brain cortex and hippocampus increased in the MW group compared with the control group, although the levels in the hippocampus were decreased by MW+melatonin administration. The brain cortex lipid peroxidation levels were unaffected by melatonin treatment. We conclude that melatonin may prevent MW-induced oxidative changes in the hippocampus by strengthening the anti-oxidant defense system, by reducing oxidative stress products.

The effect of long-term low-dose lead exposure on thyroid function in adolescents

This study investigated blood lead (Pb-B) levels and Pb-B effects on thyroid functions in long-term low-level-lead-exposed male adolescents who work as auto repairers. Pb-B and ALAD index (logarithm of activated delta-aminolaevulinic acid dehydratase/nonactivated delta-aminolaevulinic acid dehydratase) were measured as indicators of exposure to lead. Thyroid function tests including free thyroxine (FT4), free triiodothyronine (FT3), and thyrotrophin (TSH) were conducted and thyroid ultrasounds were performed in 42 lead-exposed adolescents and 55 healthy control subjects. Mean Pb-B levels and ALAD index were found significantly higher in the study group than in the normal control group (7.3+/-2.92 microg/dl vs. 2.08+/-1.24 microg/dl, P < 0.001 and 0.44+/-0.26 vs. 0.29+/-0.23, P < 0.05, respectively). FT4 levels were found significantly lower in the study group (1.02+/-0.18 mI/mL and 1.12+/-0.14 mIU/mL, P < 0.05). No subject in the control group had an abnormal FT4 level, but FT4 levels were found under normal limits in 11 subjects (26%) in the study group. FT3 and TSH levels in the study and control groups did not differ (P > 0.05). Thyroid volumes in the study and control groups did not exhibit any significant differences (P > 0.05). Pb-B was found to be negatively correlated to FT4 levels (r = -0.20, P = 0.044). This study revealed that long-term low-level lead exposure may lead to reduced FT4 level without significant changes in TSH and T3 levels in adolescents even at low Pb-B levels.

Melatonin increases NMDA receptor subunits 2A and 2B concentrations in rat hippocampus

We investigated that the effects of melatonin on N-methyl-D: -aspartat receptor (NMDAR) subunits 2A and 2B concentrations and on markers of oxidative stress in hippocampus of rats treated with melatonin for 4 weeks. Animals were divided into four groups according to their melatonin doses (control group (C), n = 7; 5 mg/kg group (M5), n = 7; 10 mg/kg group (M10), n = 8; 20 mg/kg group (M20), n = 8) and received the melatonin as intraperitoneal injection. After 4 weeks of treatment, electrophoretic examination was done using sodium dodecyl sulfate/polyacrilamide gel electrophoresis (SDS-PAGE) and Western blotting in hippocampal homogenates of different groups. Malondialdehyde (MDA), an end product of lipid peroxidation, was assayed in all groups. There were significant increases in both NMDAR 2A; 5 mg/kg group (n = 3, p < 0.05), 10 mg/kg group (n = 3, p < 0.05), 20 mg/kg group (n = 3, p < 0.05) and NMDAR 2B expressions; 5 mg group (n = 3, p < 0.05), 10 mg group (n = 3, p < 0.05), 20 mg group (n = 3, p < 0.05), compared to the control group. No significant difference in MDA concentrations was found between groups. The present study clearly demonstrates that melatonin alters hippocampal NMDAR subunit concentrations in a dose-dependent manner without causing lipid peroxidation.

EFFECT of nicotine on hippocampal nicotinic acetylcholine alpha7 receptor and NMDA receptor subunits 2A and 2B expression in young and old rats

Nicotinic acetylcholine (nAChR) and N-methyl-D-aspartate receptors (NMDARs) play critical roles in memory function. This study administered chronic nicotine to determine the alterations of N-methyl-D-aspartate receptor subunit 2A and 2B (NR2A, NR2B) and the alterations of alpha7nAChR receptor. It was determined that the effectivity of nicotine and the data support that nicotine increases hippocampal NR2A and B expression. Additionally, the role of nicotine in the cognitive improvement was not supported by the antioxidative mechanisms or the authors observed no effect of nicotine on lipid peroxidation at the hippocampus.

The effects of isoniazid on hippocampal NMDA receptors: Protective role of Erdosteine

Isoniazid (INH) has neurotoxic effects such as seizure, poor concentration, subtle reduction in memory, anxiety, depression and psychosis. INH-induced toxic effects are thought to be through increased oxidative stress, and these effects have been shown to be prevented by antioxidant therapies in various organs. Increased oxidative stress may be playing a role in these neurotoxic effects. N-methyl D-aspartat receptors (NMDA) are a member of the ionotropic group of glutamate receptors. These receptors are involved in a wide variety of processes in the central nervous system including synaptogenesis, synaptic plasticity, memory and learning. Erdosteine is a potent antioxidant and mucolytic agent. We aimed to investigate adverse effects of INH on rat hippocampal NMDAR receptors, and to elucidate whether erdosteine prevents possible adverse effects of INH. In the present study, compared to control group, NMDAR2A (NR2A) receptors were significantly decreased and malondialdehyde (MDA), end product of lipid peroxidation, production was significantly increased in INH-treated group. On the other hand, administration of erdosteine to INH-treated group significantly increased NR2A receptors and decreased MDA production. In conclusion, decreasing NR2A receptors in hippocampus and increasing lipid peroxidation correlates with the degree of oxidative effects of INH and erdosteine protects above effect of INH on NR2A receptors and membrane damage due to lipid peroxidation by its antioxidant properties.

Nitric oxide level in the nasal and sinus mucosa after exposure to electromagnetic field

OBJECTIVE

The purpose of this study was to examine the changes in nitric oxide (NO) level in the nasal and paranasal sinus mucosa after exposure radiofrequency electromagnetic fields (EMF).

STUDY DESIGN AND SETTING

Thirty male Sprague-Dawley rats were randomly grouped as follows: EMF group (group I; n, 10), EMF group in which melatonin received (group II; n, 10) and the control (sham operated) group (group III; n, 10). Groups I and II were exposed to a 900 MHz. Oral melatonin was given in group II. Control rats (group III) were also placed in the tube as the exposure groups, but without exposure to EMF. At the end of 2 weeks, the rats were sacrificed, and the nasal and paranasal sinus mucosa dissected. NO was measured in nasal and paranasal mucosa.

RESULTS

The nasal and paranasal sinus mucosa NO levels of group I were significantly higher than those of the control group (group III) ( P < 0.05). However, there was no statistically significant difference between group II and the control group (group III) regarding NO output ( P > 0.05).

CONCLUSION

Exposure to EMF released by mobile phones (900 MHz) increase NO levels in the sinus and nasal mucosa.

SIGNIFICANCE

Increased NO levels may act as a defense mechanism and presumably related to tissue damage. In addition, melatonin may have beneficial effect to prevent these changes in the mucosa.

Does melatonin protect or treat brain damage from traumatic oxidative stress?

A variety of experimental studies have demonstrated the neuroprotective effects of melatonin, based on its antioxidant activity. In a prospective randomized study, the effects of melatonin were investigated in experimental head trauma-induced oxidative stress in rabbits. The experimental study was performed on 30 rabbits. The animals were divided into three groups. Group I (sham procedure): a right parietal craniotomy was performed on each animal, and the dura mater was left intact. Group II: experimental brain trauma (EBT) was performed on each animal using a 1 cm inner diameter x 10 cm long glass tube, through which a 20 g weight (0.5 cm diameter) was dropped onto the brain at the craniotomy site, causing a contusional head trauma. Group III: the same EBT model was performed, but 2.5 mg/kg melatonin was injected intraperitoneally four times (total dose 10 mg/kg); these injections were performed 20 min before the operation, during the trauma, 1 h later and 2 h later. The rabbits were sacrificed after the EBT at 24 h after the brain trauma. The activities of the three principal antioxidant enzymes-catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px)-were determined, and the levels of malondialdehyde (MDA), a product of lipid peroxidation, and glutathione (GSH) were measured in brain homogenates. MDA levels were found to be higher in the EBT group than in the EBT+melatonin group or the sham procedure group. The SOD activity was found to be higher in the EBT group than in the sham procedure group. Enzymatic parameters (except for SOD) were significantly higher in melatonin-treated animals than in EBT animals. GSH levels in melatonin-treated animals were decreased compared with EBT animals. In conclusion, the data indicate that melatonin protects against free radical-mediated oxidative changes in brain tissue by boosting antioxidant enzymes, and in particular lowering lipid peroxidation in rabbits with EBT.

Biological and morphological effects on the reproductive organ of rats after exposure to electromagnetic field

OBJECTIVE

The biological effect of electromagnetic field (EMF) emitted from mobile phones is a current debate and still a controversial issue. Therefore, little is known on the possible adverse effects on reproduction as mobile phone bio-effects are only a very recent concern. The aim of this experimental study was to determine the biological and morphological effects of 900 MHz radiofrequency (RF) EMF on rat testes.

METHODS

The study was performed in the Physiology and Histology Research Laboratories of Süleyman Demirel University, Faculty of Medicine, Isparta, Turkey in May 2004. Twenty adult male Sprague-Dawley rats weighing 270-320 gm were randomized into 2 groups of 10 animals: Group I (control group) was not exposed to EMF and Group II (EMF group) was exposed to 30 minutes per day, 5 days a week for 4 weeks to 900 MHz EMF. Testes tissues were submitted for histologic and morphologic examination. Testicular biopsy score count and the percentage of interstitial tissue to the entire testicular tissue were registered. Serum testosterone, plasma luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels were assayed biochemically.

RESULTS

The weight of testes, testicular biopsy score count and the percentage of interstitial tissue to the entire testicular tissue were not significantly different in EMF group compared to the control group. However, the diameter of the seminiferous tubules and the mean height of the germinal epithelium were significantly decreased in EMF group (p<0.05). There was a significant decrease in serum total testosterone level in EMF group (p<0.05). Therefore, there was an insignificant decrease in plasma LH and FSH levels in EMF group compared to the control group (p>0.05).

CONCLUSION

The biological and morphological effects resulting from 900 MHz RF EMF exposure lends no support to suggestions of adverse effect on spermatogenesis, and on germinal epithelium. Therefore, testicular morphologic alterations may possibly be due to hormonal changes.

Vascular wall damage in rats induced by organophosphorus insecticide methidathion

We have examined the effect of subchronic methidathion (MD) administration on vascular wall damage. The experimental groups were: control group and rats treated with 5 mg/kg MD. The MD group was given MD by gavage for 5 days a week for 4 weeks at a dose level of 5 mg/kg per day by using corn oil as the vehicle. The levels of malondialdehyde (MDA) were determined in the vascular tissue. Histopathological examination was examined in the thoracic aortic tissue. The levels of MDA were increased in the MD group compared with the control group (P < 0.01). In the MD group, subchronic MD administration led to the irregulation, prominent breaks and fragmentation of the elastic fibers were located in the media of aortic wall. In conclusion, it is likely that subchronic MD administration caused vascular wall damage and, in addition, lipid peroxidation may be one of the molecular mechanisms involved in MD-induced vascular toxicity.

Lung injury after aortic occlusion-reperfusion in rats: the role of gadolinium chloride

Aortic ischemia-reperfusion (AIR) induced lung injury has already been documented. Kupffer cell blockage (KCB) with gadolinium chloride (GdCl3) has also been shown to attenuate remote organ damage caused by ischemia reperfusion. The present study was designed to examine the effect of GdCl3 in lung ischemia-reperfusion injury induced by aortic occlusion. Thirty-two rats were randomly allocated to four groups as follows: SHAM (Sham Laparotomy), SHAM+KCB, AIR, and AIR+KCB. An atraumatic microvascular clamp was placed across the infrarenal abdominal aorta just after its origin from the aorta for 30 minutes. The microvascular clamp on the infrarenal abdominal aorta was removed and reperfused for 60 minutes. GdCl3 was given 24 hours prior to the experiment. Malondialdehyde (MDA) level and myeloperoxidase (MPO) activity were assayed in lung tissues. MDA level and MPO activity in the AIR group were significantly higher than those in the other groups. When compared to AIR group, KCB with GdCl3 significantly decreased MDA level and MPO activity in the AIR+KCB group. These results suggest that GdCl3 attenuates the lung injury caused by AIR. The effects of GdCl3 on reduced lung damage may be mediated through significant decreases in both MDA level and MPO activity.

Beneficial Effect of the Addition of Nitroglycerin to the Cardioplegic Solution on Lipid Peroxidation During Coronary Artery Bypass Surgery

The effects of the addition of a nitric oxide (NO) donor to the cardioplegic solution on reperfusion injury and lipid peroxidation (LPO) in coronary artery bypass grafting (CABG) are not known. Therefore, this work was conducted to determine the possible effects of nitroglycerin on LPO and reperfusion injury as a result of CABG. A prospective double-blind, placebo-controlled study was conducted in 30 consecutive patients with coronary artery disease who underwent CABG with cardiopulmonary bypass. The patients were randomly assigned to receive 3 microg/kg of nitroglycerin added to the cardioplegic solution (NTG group) or 3 microg/kg of placebo added to the cardioplegic solution (placebo group). MDA increased significantly in the placebo group compared to the NTG group during the ischemic (P < 0.01) and reperfusion periods (P < 0.01). The level of troponin I decreased significantly in the NTG group compared to the placebo group during the ischemic and reperfusion periods (P < 0.001). The level of NO increased significantly in the NTG group compared to the placebo group during the ischemic and reperfusion periods (P < 0.01). LPO was increased in response to CPB during CABG, together with simultaneous decreases in serum nitric oxide levels, whereas LPO was significantly decreased in response to CPB with nitroglycerin, together with simultaneous increases in the levels of serum nitric oxide.

Renal effects and erythrocyte oxidative stress in long-term low-level lead-exposed adolescent workers in auto repair workshops

Lead poisoning is an old but persistent public health problem in developing countries. The present study investigated blood lead levels and its effects on markers of renal function and parameters of erythrocyte oxidative stress in adolescent male auto repair workers in Turkey. Blood Pb level and the ALAD index (logarithm of activated delta-aminolaevulinic acid dehydratase/nonactivated delta-aminolaevulinic acid dehydratase) were measured as indicators of exposure to Pb. Markers of tubular damage urine N-acetyl-beta-D-glucosaminidase (NAG), beta2-microglobulin (beta-2 MG), creatinine (Cr), uric acid (UA), and calcium, markers of glomerular filtration blood urea nitrogen (BUN), serum Cr, UA, and parameters of oxidative damage in erythrocyte were studied in 79 Pb-exposed adolescent and 71 healthy control subjects. Blood lead levels and ALAD index were found significantly higher in the study group than that of normal control group. BUN, UA level, and glomerular filtration rates were detected in normal range in the lead-exposed group. Urinary NAG excretion and calciuria were higher in the study group than in controls. Urinary excretion of NAG was positively correlated with the blood lead levels (r=0.427). There was no relationship between blood lead levels and UA or beta-2 MG in urine. Malondialdehyde and glutathione peroxidase levels were significantly elevated in lead-exposed adolescents than controls, but changes in the catalase and superoxide dismutase activities in lead-exposed adolescents did not reach statistical significance. In conclusion, chronic low-dose lead exposure seems as a cause of subtle renal impacts in adolescent workers of auto repair workshops. Lead-induced oxidative stress in erythrocytes probably contributes to these subclinical renal effects.

Vascular wall damage in rats induced by methidathion and ameliorating effect of vitamins E and C

We examined the effect of subacute methidathion (MD) administration on vascular wall damage and evaluated the ameliorating effects of combination of vitamins E and C against MD toxicity. The experimental groups were: rats treated with corn oil (control group), rats treated with 5 mg/kg MD (MD), and rats treated with 5 mg/kg body weight MD plus vitamin E and vitamin C (MD+Vit). The groups were given MD by gavage on 5 days a week for 4 weeks at a daily dose 5 mg/kg (MD and MD+Vit) using corn oil as the vehicle. Vitamins E and C were injected at doses of 50 mg/kg intramuscularly and 20 mg/kg intraperitoneally, respectively, after the treatment with MD in the MD+Vit group. The levels of malondialdehyde (MDA) were determined in the aortic tissue. Histopathological examination was examined in the thoracic aortic tissue. MDA levels were higher in the MD group than the control group and lower in the MD+Vit group than MD group. MD administration led to irregulation, prominent breaks, and fragmentation of the elastic fibers but decrease in the irregulation and fragmantation of the elastic fibers with the combination of vitamins E and C in MD-treated rats. In conclusion, it is likely that subacute MD administration caused vascular wall damage, and that treatment with a combination of vitamins E and C after the administration of MD can reduce vascular wall damage caused by MD.

The antioxidant effect of melatonin in lung injury after aortic occlusion?reperfusion

Acute aortic occlusion with subsequent ischemia-reperfusion of the lower extremities is well known to predispose to lung injury. Melatonin (MEL), a pineal hormone, is a free radical scavenger and an antioxidant. The purpose of this study was to assess the putative protective role of MEL in lung ischemia-reperfusion injury induced by aortic occlusion-reperfusion. Thirty-two rats were randomly allocated to four groups as follows: SHAM (Sham Laparotomy), SHAM+MEL, Aortic Ischemia Reperfusion (AIR) and AIR+MEL. Twenty mg/kg live weight MEL was given intraperitoneally 1 h prior to the experiment. An atraumatic microvascular clamp was placed across the infrarenal abdominal aorta (IAA) just after its origin from the aorta for 30 min. The microvascular clamp on IAA was removed and reperfused for 12 h. Lung tissues were assessed for malondialdehyde (MDA) level and myeloperoxidase (MPO) activity. MDA level and MPO activity, indicating the extent of lipid peroxidation and neutrophil infiltration of lung, respectively, significantly increased in AIR group when compared to SHAM and SHAM+MEL groups (P<0.05). Treating rat with MEL significantly decreased MDA levels as well as MPO activity in AIR+MEL group when compared to AIR group (P<0.05). In this study, exogenously administered MEL reduced lung injury after aortic occlusion reperfusion.

The role of free oxygen radicals on the development of otitis media with effusion

OBJECTIVE

The purpose of this study was to determine if free oxygen radicals (FORs) and antioxidant enzyme activities have some role in pathogenesis of otitis media with effusion (OME) in children with adenoid hyperplasia.

METHODS

Seventy-four patients were enrolled in three groups of this study. The study group (Group I) included 26 patients who had adenoidectomy with ventilation tube placement due to chronic OME. The control adenoid group (Group II) consisted of 28 age-matched patients who had adenoidectomy without ventilation tube insertion. Twenty children were included in the healthy control group (Group III). Erythrocyte malondialdehyde (MDA) levels, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) enzyme activities were investigated in the venous blood sample.

RESULTS

Erythrocyte MDA level and GSH-Px enzyme activity in the blood samples of study group (Group I) were significantly higher than those of Group II and Group III (P < 0.05). SOD enzyme activity in the blood samples of Group I was significantly lower than Group II (P < 0.05), and were significantly higher than Group III (P < 0.05). CAT enzyme activity of Group I was significantly lower than that of Group III (P < 0.05). However, there was no statistically significant difference between Group I and Group II regarding CAT antioxidant enzyme activity (P < 0.05).

CONCLUSIONS

The inflammation of the middle ear increases the level of FORs in erythrocyte. FOR level is normally maintained at a steady state by antioxidant enzymes. When the antioxidant defense system is weakened, the increased FORs may contribute to OME formation. We supposed that, antioxidant vitamins C and E, and scavenger enzymes such as CAT, SOD and GSH-Px may be added in the management of OME.

NMDA receptor subunits 2A and 2B decrease and lipid peroxidation increase in the hippocampus of streptozotocin-diabetic rats: effects of insulin and gliclazide treatments

Recent studies indicate that diabetes mellitus changes N-methyl-D-aspartate (NMDA) receptor subunit composition and impairs cognitive functions. It also has been known that diabetes mellitus causes lipid peroxidation. This study examined the effects of streptozotocin-diabetes and insulin or gliclazide treatment on the hippocampal NMDA receptor subunit 2A and 2B (NR2A and NR2B) concentrations. In addition, malondial dehyde (MDA) levels were measured as a marker for lipid peroxidation. Eight weeks after the induction of diabetes MDA, levels were increased, and NR2A and NR2B concentrations were reduced. Insulin and gliclazide treatment partially prevented the reduction of NR2A and NR2B expression and prevented the elevation of MDA levels. There was no significant difference between the effects of insulin and gliclazide. The results suggest that the elevation of lipid peroxidation can be the primary biochemical disturbances in diabetes progression, and that changes in NMDA receptor subunit compositions can be involved in cognitive decline in diabetes.

Splenectomy attenuates intestinal ischemia-reperfusion-induced acute lung injury

BACKGROUND/PURPOSE

Intestinal ischemia-reperfusion (IIR) induced acute lung injury (ALI) has been documented. Kupffer cell blockage with gadolinium chloride (GdCl(3)) has been shown to attenuate IIR-induced ALI. However, the effects of splenic monocytes/macrophages on IIR-induced ALI has not been studied previously. In the current study, the authors aimed to investigate the role of splenectomy in IIR-induced ALI.

METHODS

Forty-eight rats were divided randomly into 6 groups as follows: SHAM, SHAM + KCB, SHAM + SPLN, IIR, IIR + KCB, IIR + SPLN. Two hours of ischemia and 1 hour of reperfusion has been applied by clipping the SMA. GdCl3 was given 24 hours before experiment. Splenectomy was done just before SMA clipping. Lung levels of tumor necrosis-factor (TNF), interleukin (IL)-6, myeloperoxidase (MPO), and malondialdehyde (MDA) were assayed biochemically. Lung leukosequestration was determined by counting PMNLs histologically. Kruskal-Wallis and Mann-Whitney U tests were done; P values less than.003 were considered significant.

RESULTS

Polimorphonuclear leukocyte (PMNL) counts and biochemical parameters in the IIR group were significantly higher than the other groups (P <.003). When compared with IIR group, PMNL counts and biochemical parameters were significantly decreased in the IIR+KCB and IIR+SPLN groups, respectively (P <.003). However, they were still significantly higher than their sham-operated controls (P <.003).

CONCLUSIONS

This study documents that splenectomy attenuates ALI as well as Kupffer cell blockage. Spleen, an important component of mononuclear phagocytic system as liver Kupffer cells, might play an important role in the IIR-induced ALI.