Effects of selenium on endothelial dysfunction and metabolic profile in low dose streptozotocin induced diabetic rats fed a high fat diet.

Endothelial dysfunction develops as a result of oxidative stress and is responsible for diabetic vascular complications. We investigated the effects of selenium on endothelial dysfunction and oxidative stress in type 2 diabetic rats. Male Wistar rats were divided into five groups: controls, untreated diabetics, and diabetics treated with 180, 300, 500 mcg/kg selenium each day. Diabetes was induced by a single intraperitoneal injection of low dose streptozotocin to rats fed a high fat diet. Endothelium-dependent and -independent relaxations were measured in the thoracic aorta. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and endothelial nitric oxide synthase (eNOS) mRNA expressions were analyzed using real-time polymerase chain reaction (RT-PCR). Fasting blood glucose, lipid profile, lipid oxidation, insulin and nitric oxide were measured in blood samples. Malondialdehyde, superoxide dismutase, catalase and glutathione peroxidase levels were measured in liver samples. RT-PCR showed that selenium reversed increased NADPH oxidase expression and decreased eNOS expression to control levels. Selenium also improved the impairment of endothelium-dependent vasorelaxation in the diabetic aorta. Selenium treatment significantly decreased blood glucose, cholesterol and triglyceride levels, and enhanced the antioxidant status in diabetic rats. Our findings suggest that selenium restores a normal metabolic profile and ameliorates vascular responses and endothelial dysfunction in diabetes by regulating antioxidant enzyme and nitric oxide release.

The dose-dependent neuroprotective effect of alpha-lipoic acid in experimental spinal cord injury.

BACKGROUND AND PURPOSE: Free radical production after spinal cord injury (SCI) plays an important role in secondary damage. The aim of this study was to investigate neuroprotective effects of the powerful antioxidant alpha-lipoic acid (ALA) in a spinal cord clip compression injury model. MATERIAL AND METHODS: Fifty-six Sprague-Dawley rats, weighing between 210 and 300 g, were randomly divided into seven groups. Spinal cord injury was performed by an aneurysm clip placed extradurally at the level of T9. Group 1 (sham) received laminectomy only. Group 2 (control) received SCI; Group 3 received 30 mg/kg of methylprednisolone sodium succinate (MPSS); Groups 4, 5, 6 and 7 received ALA at doses of 50, 100, 150, 200 mg/kg, respectively, via the intraperitoneal route immediately after SCI. The rats were neurologically tested 24 hours after trauma. Spinal cord samples from injury sites were harvested for measurement of lipid peroxidation products and histopathological evaluation. RESULTS: Spinal cord malonyldialdehyde levels of rats in treatment groups decreased after administration of ALA. The difference between the trauma group and groups receiving MPSS-ALA was statistically significant. The difference between the ALA (50, 100, 150 mg/kg) and MPSS groups was insignificant. Group 7 (ALA 200 mg/kg) was excluded from the study because of the possible toxic effect. Alpha lipoic acid and MPSS had similar effects on spinal cord injury in terms of lipid peroxidation, neurological recovery and histopathological changes. CONCLUSIONS: Alpha lipoic acid at a dose range of 50-150 mg/ kg is as effective as MPSS (30 mg/kg) in neuroprotection after SCI. Further, more detailed experimental studies are needed to determine the effects of ALA on the detrimental results of secondary SCI before its use in humans.

Acute oxidative stress and antioxidant status responses following an American football match.

AIM: Intense physical activity is known to induce oxidative stress. Though regular physical training enhances the antioxidant defence system, the effects of diminished training periods are unclear. American football is one of the recently popular sports in Türkiye and is defined as a mixed activity. The aim of the research was to examine some markers of oxidative stress and antioxidant status in occasionally competitive American football players following a match, and relations with aerobic power and playing position. METHODS: Twenty two male players volunteered for the study. To determine oxidative stress and antioxidant status from blood samples collected before and immediately following a match, plasma malondialdehyde (MDA) and nitric oxide (NO) levels, erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities, and total antioxidant status (TAS) were assessed, using spectrophotometric methods. Wilcoxon's signed rank test was used to determine the match effect, and Mann-Whitney U test was used to compare playing position and VO2max effects. RESULTS: Plasma MDA (P<0.001) and NO (P<0.05) levels increased significantly following the match. Antioxidant parameters were unchanged following the match when compared with the resting level, except for a VO2max related effect (P<0.05) on TAS. CONCLUSION: Collected data revealed that an American football match caused excessive production of free radicals and oxidative stress. The training loads players underwent were not high enough to cause positive effects on the antioxidant status. To enhance training-induced antioxidant status adaptation, higher amounts of physical activity may be required.

Effect of thinning on density of Pinus nigra tree using X-ray computed tomography.

This study was carried out to determine the effect of thinning on density, extractives and lignin content of Pinus nigra Amold tree. Wood density was measured with computed tomography and 540+/-20 kg m(-3) were determined on control samples. Density of samples from thinning applied plot was 520+/-20 kg m(-3). The results showed that thinning slightly changes the density of wood and this change is caused by springwood content. In contrast, extractives and lignin content were not changed with thinning.

The protective mechanisms of defibrotide on liver ischaemia-reperfusion injury.

During some surgical interventions, temporary occlusion of the hepatic blood supply may cause ischaemia-reperfusion (I/R) injury and hepatic dysfunction. In this study the protective effect of defibrotide (DEF) was evaluated in a rat model of liver I/R injury. Four groups of rats were subjected to the following protocols: saline infusion without ischaemia, DEF infusion without ischaemia, DEF infusion with hepatic I/R, and saline infusion with hepatic I/R. After a midline laporatomy, liver ischaemia was induced by 45 min of portal occlusion. DEF 175 mg/kg(-1) was infused before ischaemia in 10 ml of saline. The same volume of saline was infused into the control animals. At the end of the 45-min reperfusion interval, the animals were sacrified. Superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) enzyme activities were determined in haemolysates, and malondialdehyde (MDA) level in the liver tissue was measured. Tissue MDA levels were significantly higher in the I/R plus saline group compared to the sham operation control groups (p < 0.01 and p < 0.05, respectively). Tissue MDA levels decreased in the DEF plus I/R group compared to the I/R plus saline group (p < 0.05), but DEF could not reduce tissue lipid peroxidation to the levels of the control sham operation groups. SOD and GSH-Px enzyme activities were significantly higher in DEF-treated animals than in the other groups (p < 0.05). These results suggest that DEF protects liver against I/R injury by increasing the antioxidant enzyme levels.

Clomiphene citrate does not adversely affect endometrial leukemia inhibitory factor levels.

The aim of this study was to compare endometrial leukemia inhibitory factor (LIF) levels in spontaneous and clomiphene citrate (CC)-induced cycles of patients with unexplained infertility. The patients were followed in two consecutive cycles. Endometrial samples were obtained 7 days after ultrasonographic evidence that ovulation has occurred during the spontaneous cycle, then the patients were induced with CC from day 5 to day 9 during the subsequent cycle with 50 mg/day, and ovulation monitoring and endometrial biopsy were performed in the same manner. The samples were obtained using a Pipelle biopsy device without using local anesthesia, and kept in formaldehyde solution until the day of measurement. Then they were homogenized in phosphate buffered distilled water, and LIF levels were detected in the homogenized fluid by ELISA method. Endometrial LIF levels were 470 +/- 52 and 501 +/- 45 pg/1 gram wet tissue in spontaneous and CC-induced cycles respectively, revealing no significant difference. Ovulation induction with CC did not adversely affect endometrial LIF levels.

Immunolocalization of transforming growth factor-beta 3 in pregnant human myometrium.

BACKGROUND: Transforming growth factor-beta 3 is a cytokine which is involved in cell growth regulation and differentiation, stimulation of extracellular matrix and modulation of immune responses. The goal of this study was to detect the presence of this cytokine in the myometrium of preterm and term, nonlaboring and laboring patients, and to measure serum levels of interleukin-1 beta (IL-1 beta), IL-6 and IL-8 before cesarean section. METHODS: In this prospective study, we obtained samples of myometrium from the lower uterine segment during elective and emergency cesarean sections (term non-laboring, n=8; term laboring, n=7; preterm non-laboring, n=3; and preterm laboring, n=19) and stained for transforming growth factor-beta 3. Blood was also sampled from the same patients to determine IL-1 beta, IL-6 and IL-8 levels. RESULTS: Different intensities of staining were detected in preterm laboring, term nonlaboring and term laboring groups, but there was no staining in preterm nonlaboring group. We also found a statistically significant difference in IL-6 levels between laboring and nonlaboring groups (p=0.028). CONCLUSION: Different intensities of TGF-beta 3 which appeared in different stages of myometrium made us consider that TGF-beta 3 might prepare myometrium to labor, and IL-6 was more important than the other interleukins in initiation of labor.

Testicular nitric oxide levels after unilateral testicular torsion/detorsion in rats pretreated with caffeic acid phenethyl ester.

Nitric oxide (NO) plays an important role in modulating blood flow in normal and in several pathological conditions, and its levels seem to change with ischemia-reperfusion injuries. Caffeic acid phenethyl ester (CAPE), an active component of propolis, exhibits antioxidant properties. This experimental study was designed to determine the changes in NO levels and the effect of CAPE on NO levels after testicular torsion/ detorsion in rats. Thirty-five adult male albino rats were divided into four groups: sham operation (n = 8), torsion (n = 9), saline/detorsion (n = 9), and CAPE/detorsion (n = 9). Rats in the sham operation group were killed after the testes were handled without torsion. Rats in the torsion group were killed after 720 degrees clockwise testicular torsion for 2 h. CAPE was administered 30 min before detorsion in the CAPE/detorsion group and saline was administered in the saline/detorsion group. After 4 h of testicular detorsion in both of these groups, the rats were killed and bilateral orchiectomy was performed to determine the tissue levels of NO. The level of NO in the torsion group (113.77 +/- 33.18 nmol/g protein) was significantly higher than that of the sham operation group (64.53 +/- 29.64 nmol/g protein). In the saline/detorsion group, the NO level (31.26 +/- 12.58 nmol/g protein) was significantly lower than in the torsion and sham operation groups. CAPE administration in the CAPE/detorsion group seemed to raise the NO level (72.63 +/- 23.87 nmol/g protein) above the level of the sham operation group. Contralateral testes were not affected by the torsion/detorsion processes performed on the ipsilateral testes. These results show that NO levels increase with torsion and decrease with detorsion. CAPE administration seems to increase tissue NO levels and this may be important for protecting the testes from torsion/detorsion injuries.

Serum and hair trace element levels in patients with epilepsy and healthy subjects: does the antiepileptic therapy affect the element concentrations of hair?

In this study, hair magnesium (Mg), zinc (Zn), copper (Cu), and manganese (Mn) levels, and serum Zn and Mg levels were measured by atomic absorption spectrophotometer in patients with epilepsy (n = 33) and healthy subjects (n = 21), and results obtained were statistically compared. The mean hair Cu, Mg, and Zn levels of epileptic patients were significantly lower than the levels of control subjects. There was no significant difference between epileptic patients and control subjects in respect to the mean Mn levels. Mean serum Mg levels in epileptic patients showed significant difference, but serum Zn levels were similar among both groups. When the effects of anticonvulsant therapy on Cu, Zn, Mn, and Mg in the hair, and Mg and Zn in the serum were analyzed in epileptics, there was no significant difference between the patients with or without therapy. Likewise, the mean trace element levels in epileptics showed no significant difference according to the type of antiepileptic drug and seizure, and gender. We suggest that the changed element status (Zn, Mg, and Cu) in hair may play an indicator role in the diagnosis of epileptic patients.