Biomedical subjects

Omer Ozcan

Publications and source records attributed to Omer Ozcan.

12 recordsLinked to original sources

PubMed2006

Effects of nebivolol on platelet activation in hypertensive patients: a comparative study with metoprolol.

OBJECTIVES: We evaluated the effects of nebivolol on platelet activation in hypertensive patients by measuring mean platelet volume (MPV) and plasma soluble P-selectin (sP-sel) levels and compared with those of the patients taking metoprolol. MATERIALS AND METHODS: Eighty newly diagnosed hypertensive patients in grade 1 hypertension were enrolled in this prospective, blinded randomized study. Seventy two patients completed the study. After baseline assessment, each patient was randomly allocated to 5 mg daily dose of nebivolol (n=37, 20 male) or 100 mg daily dose of metoprolol (n=35, 18 male) and treated for 6 months. Blood pressure, heart rate, lipid profile, plasma glucose, sP-selectin levels, platelet counts and MPV were measured before and after treatment. RESULTS: At the end of 6 months, nebivolol significantly decreased MPV and plasma sP-selectin levels (7.59+/-0.78 fl vs. 7.42+/-0.74 fl, p<0.001; 1.29+/-0.46 ng/ml vs. 1.21+/-0.36 ng/ml, p=0.002, respectively) compared to those of pretreatment. Although pretreatment sP-selectin levels of the two groups were similar, posttreatment plasma sP-selectin levels were significantly reduced with nebivolol compared with those of metoprolol group (1.21+/-0.36 ng/ml vs. 1.46+/-0.30 ng/ml, p=0.008). In contrast, metoprolol treatment did not cause any significant change in platelet activation parameters after treatment. CONCLUSION: Beneficial effects of nebivolol on platelet activation were more potent than those of metoprolol. We consider that decreased platelet activation with nebivolol might play a role to reduce thrombotic risk in hypertensive patients.

Antihypertensive Agents↗

PubMed2006

Serum HDL-C levels, log (TG/HDL-C) values and serum total cholesterol/HDL-C ratios significantly correlate with radiological extent of disease in patients with community-acquired pneumonia.

BACKGROUND: In several studies, it was shown that there was a marked decrease in serum levels of HDL-C during infection and inflammation in general. In particular, a decrease in the level of serum HDL-C was also shown in pneumonia. Correlations between inflammatory markers such as acute phase proteins, cytokines and serum HDL-C levels were shown. However, there are no studies indicating a correlation between serum HDL-C levels and the radiological extent of the disease (RED) in community-acquired pneumonia (CAP). AIM: We hypothesized that there could be a relationship between serum HDL-C levels and RED in CAP. MATERIALS AND METHODS: A case-controlled study, including 97 patients with CAP and 45 healthy subjects, was performed. Chest X-rays of CAP patients were scored for RED, and correlations were investigated between RED scores, serum lipid parameters, the erythrocyte sedimentation rate (ESR) and serum albumin levels. RESULTS: The mean serum HDL-C level was lower in CAP patients than in controls. A significant and negative correlation between RED scores (REDS) and serum HDL-C levels was detected (r = -0.64, P = 0.0001). There were also significant correlations between REDS and other lipid parameters. Significant correlations between ESR and serum HDL-C levels and between ESR and other serum lipid parameters were also found. CONCLUSION: It appears that serum HDL-C levels are generally lower in CAP cases than in healthy controls. Serum HDL-C levels and serum albumin levels might decrease and serum total cholesterol/HDL-C ratios and log (TG/HDL-C) values might increase proportionally with RED in CAP patients. These results might have some significance for individuals having long-standing and/or recurrent pneumonia and other cardiovascular risk factors.

Adolescent↗

PubMed2006

The determinants of endothelial dysfunction in CKD: oxidative stress and asymmetric dimethylarginine.

BACKGROUND: Oxidative stress is related to endothelial dysfunction (ED) and cardiovascular outcomes in patients with chronic kidney disease. Increased asymmetric dimethylarginine (ADMA) levels are among the main causes of ED. We aim to investigate any association between ED and ADMA levels, as well as levels of oxidative stress markers, in patients with chronic kidney disease. METHODS: One hundred fifty-nine patients without diabetes with chronic kidney disease were studied. Staging was performed according to glomerular filtration rate, determined as stages 1 to 5 according to the Kidney Disease Outcomes Quality Initiative (n = 30, 33, 28, 32, and 36, respectively). The control group consisted of 30 healthy subjects. Oxidative stress markers (plasma malondialdehyde [MDA], erythrocyte superoxide dismutase [SOD], glutathione peroxidase [GSH-Px]), trace elements (erythrocyte zinc [EZn], erythrocyte copper [ECu]), plasma selenium (Se), and serum ADMA were studied. Brachial artery endothelium-dependent vasodilatation (FMD) was calculated for all. RESULTS: FMD, SOD, GSH-Px, EZn, ECu, and Se values were lower, whereas MDA and ADMA levels were higher in patients than controls. Glomerular filtration rate correlated negatively with MDA and ADMA levels and positively with FMD, SOD, and GSH-Px values. These parameters were significantly different among patients with stages 2, 3, 4, and 5 (hemodialysis group; P < 0.001 for all). Regression analysis showed that ADMA (beta = -0.228; P < 0.01), SOD (beta = 0.405; P < 0.001), and oxidized low-density lipoprotein levels (beta = -0.428; P < 0.001) were related independently to FMD, whereas glomerular filtration rate was not involved in the model. CONCLUSION: The present results imply that FMD, oxidative stress, and ADMA levels all are associated with stage of chronic kidney disease. Additionally, levels of oxidative stress markers and ADMA independently determine endothelial function.

Adult↗

PubMed2006

Comparative effects of nebivolol and metoprolol on oxidative stress, insulin resistance, plasma adiponectin and soluble P-selectin levels in hypertensive patients.

OBJECTIVES: To determine the effects of nebivolol on oxidative stress, insulin resistance, adiponectin and plasma soluble P-selectin levels in hypertensive patients in comparison with metoprolol. MATERIAL AND METHODS: Eighty newly diagnosed hypertensive patients in grade 1 hypertension according to the European Society of Hypertension and European Society of Cardiology guidelines were enrolled in this prospective, blinded, randomized study. Seventy-two patients completed the study. After baseline assessment, each patient was randomly allocated to a 5 mg daily dose of nebivolol (n = 37, 20 male) or a 100 mg daily dose of metoprolol (n = 35, 18 male) and treated for 6 months. Blood pressure, heart rate, oxidative stress (malonyldialdehyde), homeostasis model assessment: insulin resistance, adiponectin and plasma soluble P-selectin levels were measured before and after treatment. RESULTS: At the end of treatment, nebivolol and metoprolol significantly decreased blood pressure and heart rate, with a more pronounced bradycardic effect of metoprolol. Nebivolol, but not metoprolol, significantly lowered oxidative stress (P = 0.03), the insulin resistance index (P = 0.003) and plasma soluble P-selectin levels (P = 0.008), and increased adiponectin levels (P = 0.04). CONCLUSION: Nebivolol, in contrast to metoprolol, improved oxidative stress, insulin sensitivity, decreased plasma soluble P-selectin and increased adiponectin levels in hypertensive patients. These beneficial effects of nebivolol may contribute to a reduction in cardiovascular risk in hypertensive patients.

Adiponectin↗

PubMed2006

[Early enteral and glutamine enriched enteral feeding ameliorates healing of colonic anastomosis: experimental study].

BACKGROUND: To investigate the effects of postoperative early enteral and glutamine enriched enteral feeding on the healing of experimental colonic anastomosis. METHODS: Forty Wistar-albino rats were equally divided into 4 groups. Colonic transsection and anastomosis situated at the distal left colon was performed on all animals. Animals in groups 1 and 2 received late total enteral nutrition (TEN) and in groups 3 and 4 early TEN. Glutamine was added to TEN protocol in groups 2 and 4. The colonic segment including the anastomosis was excised at the end of the 7th day postoperatively. Bursting pressure of the anastomosis and tissue hydroxyproline levels were determined. RESULTS: Bursting pressure levels were 111.6 and 95.8 centimeters of water (cmH(2)O) in early and late nutrition groups, respectively (p=0.022). Comparison of late TEN groups showed a significant difference in favor of group with glutamine (95.8 vs 138.5 cmH(2)O; p<0.0001). Highest bursting pressures (139 and 138.5 cmH(2)O) were measured in both early and late TEN groups with glutamine. Tissue hydroxyproline level in early TEN group (2440.3 microg) was significantly higher than late TEN group (1509.6 microg; p=0.024). Comparison of late TEN groups showed a considerable but not statistically significant difference (p=0.276) in favor of group with glutamine (1509.6 vs 1981.6 microg). CONCLUSION: Postoperative early TEN significantly ameliorates the resistance of the anastomosis and collagen synthesis. Glutamine enrichment in nutritional protocol decreases and reverses the disadvantages of late TEN regarding the resistance of anastomosis. A similarly positive, albeit weaker, effect of glutamine supplementation is also seen on collagen synthesis.

Anastomosis, Surgical↗

PubMed2005

Endothelial functions improve with decrease in asymmetric dimethylarginine (ADMA) levels after renal transplantation.

BACKGROUND: Chronic kidney disease (CKD) is associated with increased cardiovascular events. The relationships between the markers of inflammation and endothelial dysfunction were investigated both before and after living donor kidney transplantation. METHODS: Twenty-seven renal transplant patients were studied. Eleven patients (six male, five female) were on cyclosporine A, whereas 16 patients (nine male, seven female) were treated with tacrolimus based regimes. Twenty-seven subjects (12 males, 15 females) were studied as controls. Plasma adiponectin, high sensitive C reactive protein (hsCRP), Asymetric dimethyl arginine (ADMA) levels were studied before transplantation and on days 1, 3, 7, 14, and 28. The brachial artery flow mediated dilatation (FMD) was studied before transplantation and on the 28th day. RESULTS: Serum hsCRP and ADMA levels decreased significantly from the first posttransplantation day on each measurement (P<0.001 for all) while the decrement of plasma adiponectin started in the third day (P<0.001 for all). The FMD was lower in the patients than the control group (P<0.001) and improved significantly in the 28th day of transplantation (P<0.001). CONCLUSIONS: The results indicate that ADMA is associated with FMD in CKD both before and after kidney transplantation. Endothelial functions improve at the very beginning of the posttransplantation period with accompanying reduction in ADMA and hsCRP levels.

Adult↗

PubMed2005

Elevated urine neopterin levels in nonalcoholic steatohepatitis.

OBJECTIVES: The aim of this study was to relate urine levels of neopterin, a marker of activation of the cellular immune system, with grading and staging of NASH. DESIGN AND METHODS: Urine concentrations of neopterin, routine tests, insulin and C-peptide levels were assessed in 50 patients with NASH, 25 patients with chronic viral hepatitis (CVH), and in 26 healthy controls. RESULTS: Urine neopterin levels were found elevated in the NASH and CVH groups compared with controls. There was no significant correlation between urine neopterin levels and inflammation grade in the liver. CONCLUSIONS: Urine neopterin levels are a marker of cellular immunity and are higher in patients with NASH. However, neopterin levels were not significantly associated with histopathological grade and stage of disease.

Adult↗

PubMed2005

Pleural fluid and serum procalcitonin as diagnostic tools in tuberculous pleurisy.

BACKGROUND: Diagnosis of tuberculous pleuritis is difficult because of its nonspecific clinical presentation and decreased efficiency of traditional diagnostic methods. We investigated the use of procalcitonin (PCT) concentration in tuberculous pleuritis diagnosis. METHODS: A prospective clinical study was performed with two different patient groups. A total of 28 patients were included: 18 with tuberculosis and 10 with nontuberculous pleurisy. Serum and pleural fluid PCT concentrations were evaluated before treatment. RESULTS: Serum and pleural fluid PCT concentrations were statistically different between tuberculous and nontuberculous pleurisy groups (P = 0.012 and P = 0.004, respectively), even though they were not elevated in relation to the cut-off level of 0.5 ng/mL. A positive and significant correlation was detected between serum and pleural fluid PCT levels (r = 0.49, P = 0.008). Diagnostic specificity and sensitivity values for serum and pleural fluid PCT in discriminating tuberculous from nontuberculous pleurisy were 80% and 72.2%, and 90% and 66.7% at the 0.081 and 0.113 ng/mL cut-off values, respectively. CONCLUSION: Relative to the current cut-off level of 0.5 ng/mL, PCT concentration is not a useful parameter for the diagnosis of tuberculous pleurisy. Because there were PCT levels in patients with tuberculous pleurisy that were below the current cut-off level but were significantly different from those of the nontuberculous group, the use of PCT should be further investigated.

Adolescent↗

PubMed2005

Correlation between hyperbaric oxygen exposure pressures and oxidative parameters in rat lung, brain, and erythrocytes.

OBJECTIVES: The oxygen toxicity risk of hyperbaric oxygen (HBO) treatment has long been of interest. However, there are no comprehensive articles describing the relationship between HBO protocols and oxidative parameters used clinically. The purpose of this study was to determine the effects of various HBO pressure modalities on the oxidative values of rat lung, brain, and erythrocytes. DESIGN AND METHODS: A total of 64 male Sprague-Dawley rats was randomly divided into 7 groups. Group A was used as a control. Groups C to G were subjected to 100% oxygen at a pressure of 1, 1.5, 2, 2.5, and 3 ATA (atmosphere absolute), respectively, for 2 h. Group B was exposed to normal atmospheric air at 3 ATA for the same duration. The rat's lung, brain, and blood were taken immediately after the exposure and thiobarbituric acid reactive substances (TBARS) and superoxide dismutase (SOD) levels were determined. RESULTS: Both TBARS levels and SOD activity increased concordantly with the pressure increase. Although a statistically significant change in TBARS levels started from 100% oxygen exposure at 1 ATA (normobaric), SOD activity was affected after 2 ATA. A significant correlation exists between exposure pressure and the aforementioned parameters. Ambient air exposure at 3 ATA did not affect any parameters besides the brain TBARS levels. CONCLUSIONS: It is clear that HBO exposure causes oxidative stress. The main reason for this effect seems to be exposure to pure oxygen, since pure high pressure has no significant effect on the aforementioned parameters. However, clinicians should use as low pressures as possible since all oxidative parameters appear to be directly proportional to the extent of HBO exposure.

Animals↗

PubMed2005

The effects of thyroxine replacement on the levels of serum asymmetric dimethylarginine (ADMA) and other biochemical cardiovascular risk markers in patients with subclinical hypothyroidism.

BACKGROUND: The relationship between subclinical hypothyroidism (SH) and cardiovascular disease (CVD) is still under debate. The purpose of the present study was to evaluate plasma total homocysteine (tHcy), high sensitive C-reactive protein (hsCRP), small dense low-density lipoprotein (sdLDL), L-arginine and asymmetric dimethylarginine (ADMA) concentrations and their relationship to nitric oxide (NO) production, measured as plasma nitrite-plus-nitrate (NO(x)) concentration, in patients with SH before and after thyroxine replacement therapy and compared with control group values. DESIGN: Eighty-four women with SH and 33 healthy women as controls matched to the patient group for sex, age and body mass index (BMI), were enrolled in this study. Lipoprotein profile, tHcy, hsCRP, sdLDL, ADMA, L-arginine and NO(x) were measured in pre- and post-treatment blood samples. RESULTS: The pretreatment total cholesterol (TC), LDL-C, hsCRP, ADMA and L-arginine levels were significantly higher and NO(x) levels were lower than in the control group. After treatment, hsCRP, ADMA and L-arginine levels were significantly reduced and sdLDL and NO(x) levels were significantly increased. CONCLUSION: The present study demonstrated an elevation of hsCRP and ADMA plasma levels of patients with SH associated with a reduction in NO production, which may contribute to some cardiovascular alterations. The elevated ADMA and hsCRP levels were reduced after thyroxine replacement. Also the sdLDL levels of SH patients were found to be lower than the control group values whereas TC and LDL were elevated. Even though we found an elevation in sdLDL levels after treatment, those values were still not higher than in the control group.

Adolescent↗

PubMed2005

Assessment of iodine intake in mildly iodine-deficient pregnant women by a new automated kinetic urinary iodine determination method.

Maternal iodine deficiency can compromise the thyroid status of the mother, fetus and newborn child. Therefore, it is important to assess the iodine excretion level of groups of pregnant women. In this study we aimed to determine iodine intake in pregnancy using a recently reported automated kinetic method for urinary iodine determination. Urinary iodine measurements of 123 pregnant women (18 first, 28 second and 77 third trimester) were carried out using a new automated kinetic assay based on the Sandell-Kolthoff reaction at 37 degrees C and its kinetic measurement at 340 nm in a random-access automated analyzer after ammonium persulfate digestion at 95 degrees C in a water bath with +/-0.1 degree C precision. Statistical analyses were carried out using SPSS software. Whole group, first trimester, second trimester and third trimester urinary iodine concentrations (mean+/-SD) in pregnant women were 1.13+/-0.81, 1.08+/-0.71, 0.86+/-0.58 and 1.27+/-0.87 micromol/L, respectively. The urinary iodine concentration significantly increased with gestational age (p<0.05). We found that our study group was mildly iodine-deficient according to WHO criteria. Furthermore, the pregnant women were found to be mildly iodine-deficient in the first and third trimesters and moderately so in the second trimester. The only statistical difference was between second and third trimester values (p<0.05). Even though the increased iodine deficiency in the second trimester is not useful for early detection of iodine deficiency in pregnancy, the severity of this deficiency in the second trimester may lead to important effects on thyroid metabolism for both mother and fetus. Our study suggests that the iodine excretion of pregnant women living in iodine-deficient areas could be assessed using this fast and automated method.

Adolescent↗

PubMed2004

Elevated plasma concentration of asymmetric dimethylarginine that is reduced by single dose testosterone administration in idiopathic hypogonadotropic hypogonadism patients.

Our aim was to investigate whether plasma l-arginine and asymmetric dimethylarginine (ADMA) concentrations and nitric oxide (NO) production are altered in male idiopathic hypogonadotropic hypogonadism (IHH) patients in the hypogonadal state and after single dose testosterone administration compared with those in control subjects. Eighteen newly diagnosed male patients with IHH and 20 healthy volunteer controls matched by age and body mass index were enrolled in the study. Single dose testosterone was administrated im. Initially, pretreatment blood samples were collected after overnight fasting. Posttreatment blood samples were drawn 10 d after the injection. ADMA, l-arginine, and NO were measured in pre- and posttreatment blood samples. The pretreatment ADMA and l-arginine levels were significantly higher, and plasma nitrite plus nitrate (NOx) levels were lower than those in the control group. After 10 d of treatment, ADMA and l-arginine levels were significantly reduced, and NOx levels were significantly increased. There was a significant positive correlation (P < 0.01) between ADMA and l-arginine and a negative correlation between ADMA and NOx levels in patients and controls. In conclusion, the patients with IHH showed elevated plasma ADMA levels associated with a reduction in NO production. Single dose parenteral T administration lowered ADMA concentrations and increased NO production to the control group values.

Adult↗