Murat Ormen

The protective effects of carnosine and melatonin in ischemia-reperfusion injury in the rat liver.

The reperfusion following liver ischemia results in hepatocyte damage and apoptosis. The aim of this study was to investigate the effects of two antioxidant agents, carnosine and melatonin, in rat liver ischemia-reperfusion injury. Five study groups were formed; I. sham, II. ischemia-reperfusion, III. ischemia-reperfusion+melatonin, IV. ischemia-reperfusion+carnosine, V. ischemia-reperfusion+melatonin+carnosine. Then 250 mg/kg carnosine and 10 mg/kg melatonin were administered intraperitoneally 30 min before ischemia and immediately after the reperfusion. Sinusoidal dilatation, congestion and neutrophil infiltration were observed in the ischemia-reperfusion group while these symptoms were less pronounced in the treatment groups. Alanine aminotransferase, aspartate aminotransferase and myeloperoxidase levels were increased in the ischemia-reperfusion group while they were lowered in the treatment groups. Glutathione level was low in the ischemia-reperfusion group while it tended to increase in the ischemia-reperfusion+carnosine administered and ischemia-reperfusion+carnosine+melatonin administered groups. There was an increase in the number of apoptotic cells in the ischemia-reperfusion group while this number was lowered in the treatment groups. Carnosine was more effective than melatonin in the reversal of structural and biochemical alterations that resulted from ischemia-reperfusion injury. The administration of melatonin and carnosine together yielded better outcomes compared to the sole administration of each agent.

Pregnenolone protects the PC-12 cell line against amyloid beta peptide toxicity but its sulfate ester does not

Pregnenolone (P), the main precursor of the steroids, and its sulfate ester, pregnenolone sulfate (PS), are the major neurosteroids produced in the neural tissue. Many neuroendocrinological studies stressed the neuroprotective role of neurosteroids although it has been suggested that the inhibition of P and PS synthesis can delay neuronal cell death. The potential roles of P and PS in vital neuronal functions and in amyloid beta peptide (Abeta) toxicity are not clearly identified. This work aims to investigate the effects of P and PS on cell viability and Abeta peptide toxicity in a concentration and exposure time-dependent manner in rat PC-12 cells. The cells were treated with 20muM Abeta peptide 25-35 and variable concentrations of P and PS ranging from 0.5muM to 100muM. To examine the effects of steroid treatment on Abeta peptide toxicity, 0.5muM (low) and 50muM (high) neurosteroids were used. The cell viability and lactate dehydrogenase release of cells were evaluated after 24, 48 and 72h. Morphological changes of cells were also examined. The treatment with higher than 1muM concentrations of P and PS significantly decreased the cell viability comparing to untreated cells. At lower concentrations, P and PS had no toxic actions until 72h. The Abeta treatment resulted in a significant decrease in cell viability comparing to untreated cells. P showed a dose-dependent protective effect against Abeta peptide in PC-12 cells. But its sulfate ester did not have the same effect on Abeta peptide toxicity, even it significantly decreased cell viability in Abeta-treated cells. Consequently, the discrepant effects of P and PS on Abeta peptide toxicity may provide insight on the pathogenesis of Alzheimers disease.

Effects of N-acetylcysteine on radiocontrast nephropathy in rats

Objective. N-acetylcysteine (NAC) has yielded some promising results recently in the prevention of radiocontrast nephropathy (RCN). In this study, the structural and functional effects of NAC on RCN were analyzed. Material and methods. Twenty-eight Wistar rats were randomized into four groups, as follows: Group 1, controls; Group 2, contrast; Group 3, contrastu200a+u200aNAC; and Group 4, NAC. All rats were deprived of water for 24u2009h and then contrast medium (ioxoglate; 10u2009ml/kg) was administered to Groups 2 and 3. NAC (50u2009mg/kg) was introduced enterally to Groups 3 and 4 at a dose of 50u2009mg/kg in 0.5u2009ml of distilled water, in four sequential doses 12u2009h apart, starting after 12u2009h of water deprivation. After 4 days, rats were sacrificed. Creatinine clearance was calculated. The malondialdehyde (MDA) level was quantified in tissue samples. Slides stained with hematoxylin–eosin and periodic acid–Schiff were examined by means of light microscopy. Each tubular cross-section from all images was scored as either mild (preserved brush border, no necrosis), moderate (loss of brush border, no necrosis) or severe (loss of brush border accompanied by necrosis) and the frequencies of these lesion severities were compared. Results. Mean baseline serum creatinine levels and creatinine clearances were similar in all groups. Mean serum creatinine level increased significantly only in Group 2 (0.6±0.1 vs 0.7±0.2u2009mg/dl; p<0.05). Tissue MDA levels were similar in all groups. Moderate (13.8%±1.5% vs 42%±1.4%; p<0.05) and severe (0% vs 40%±2.1%; p<0.05) lesions were significantly more frequent in Group 2 compared to Group 1. The frequency of severe lesions in Group 3 was found to be halved compared to that in Group 1 (40%±2.1% vs 20.2%±0.86%; p<0.05). Conclusion. NAC protects the kidneys following exposure to contrast medium as it decreased the severity of tubular lesions in rats.

The Effects of Resistance Training on Cardiovascular Disease Risk Factors in Postmenopausal Women: A Randomized-Controlled Trial

Our aim was to determine the effects of resistance training on cardiovascular risk factors in postmenopausal women. Forty-five women were included in the study. Resistance exercises were done with an intensity of 60% of 1-Repetition Maximum, for 12 weeks. Heart rate, blood pressure, estimated peak VO2, lipid profiles, and homocysteine levels were evaluated. There were significant time and group interactions for body mass index (p = .02), heart rate (p = .04), systolic blood pressure (p = .03), estimated mean peak VO2 (p = .00), and total cholesterol (p = .00), but there were no interactions with other evaluated parameters. Resistance training has beneficial effects on particular cardiovascular risk factors in postmenopausal women.

Nitric Oxide Levels in Disruptive Behavioral Disorder

There are various evidences of the role of nitric oxide (NO) in several neuropsychiatric disorders. However, there is no clinical study which investigated the role of NO in disruptive behavioral disorders (DBD). The aim of this study is to investigate the relation between NO levels and DBD. NO levels were measured in serum from 45 patients diagnosed as having DBD (30 patients with a diagnosis of attention deficit and hyperactivity disorder [ADHD] and 15 with ADHD + oppositional defiant disorder [ODD]) and 51 healthy control subjects. It is statistically significant that the pure ADHD group’s blood NO levels are lower than those of both the ADHD + ODD and control groups. There was no significant difference between the ADHD + ODD group and the controls. The difference of the NO levels in DBD may indicate the effect of NO in the etiology of this disorder spectrum.

A nationwide multicentre study in Turkey for establishing reference intervals of haematological parameters with novel use of a panel of whole blood

Introduction A nationwide multicentre study was conducted to establish well-defined reference intervals (RIs) of haematological parameters for the Turkish population in consideration of sources of variation in reference values (RVs). Materials and methods K2-EDTA whole blood samples (total of 3363) were collected from 12 laboratories. Sera were also collected for measurements of iron, UIBC, TIBC, and ferritin for use in the latent abnormal values exclusion (LAVE) method. The blood samples were analysed within 2 hours in each laboratory using Cell Dyn and Ruby (Abbott), LH780 (Beckman Coulter), or XT-2000i (Sysmex). A panel of freshly prepared blood from 40 healthy volunteers was measured in common to assess any analyser-dependent bias in the measurements. The SD ratio (SDR) based on ANOVA was used to judge the need for partitioning RVs. RIs were computed by the parametric method with/without applying the LAVE method. Results Analyser-dependent bias was found for basophils (Bas), MCHC, RDW and MPV from the panel test results and thus those RIs were derived for each manufacturer. RIs were determined from all volunteers’ results for WBC, neutrophils, lymphocytes, monocytes, eosinophils, MCV, MCH and platelets. Gender-specific RIs were required for RBC, haemoglobin, haematocrit, iron, UIBC and ferritin. Region-specific RIs were required for RBC, haemoglobin, haematocrit, UIBC, and TIBC. Conclusions With the novel use of a freshly prepared blood panel, manufacturer-specific RIs’ were derived for Bas, Bas%, MCHC, RDW and MPV. Regional differences in RIs were observed among the 7 regions of Turkey, which may be attributed to nutritional or environmental factors, including altitude.

Effect of Blood Cell Subtypes Lysis on Routine Biochemical Tests

Summary Background: The aim of this study is to establish the contribution of blood cells subtypes on hemolysis. Methods: Separated blood cell subtype suspensions prepared with blood from 10 volunteers were serially diluted to obtain different concentrations of cell suspensions. The cells were fully lysed and cell hemolysates were added (1:20) to aliquots of serum pool. Thus, seven serum pools with different concentrations of interferent were obtained for each blood cell subtype. Biochemical parameters and serum indices were measured by an autoanalyzer. As cell lysis markers, free hemoglobin was measured by spectrophotometry while myeloperoxidase and b-thromboglobulin were measured by enzyme immunoassay. The percent changes in analyte levels of the serum pools were evaulated by Wilcoxon Signed Rank Test and compared with clinical thresholds defined for each test. Results: The clinical thresholds were exceeded in lactate dehydrogenase, potassium, aspartate aminotransferase, creatine kinase, magnesium, total protein, total cholesterol, inorganic phosphate, glucose for red blood cells (RBC); lactate dehydrogenase, aspartate aminotransferase, total protein, inorganic phosphate and glucose for platelets (PLT). Free hemoglobin was significantly correlated with RBC (r=0.999; p=0.001), while myeloperoxidase and b thromboglobulin showed no significant correlation to white blood cells (WBC) and PLT, respectively. Conclusion: The effect of RBC hemolysis in serum on the routine biochemical tests are clearly established, yet, additional studies are required in order to verify this kind of effects of PLT and WBC hemolysis.