Omer Ozcan

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.

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.

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 (NOx) concentration, in patients with SH before and after thyroxine replacement therapy and compared with control group values.

Uric Acid as a Marker of Oxidative Stress in Dilatation of the Ascending Aorta

BACKGROUND Increased serum uric acid (UA) has been shown to directly promote oxidative stress. Recent studies point toward a role for oxidative stress in the pathogenesis of ascending aortic aneurysms (AscAAs). This study was designed to examine the relationship between serum UA concentrations, total antioxidant reductive capacity, and AscAAs. METHODS The serum UA concentrations, total antioxidant reductive capacity were compared in 60 patients with ascending aortic dilatation (ectasia group (3.8-4.3 cm), 34 patients; aneurysmal group (≥4.4 cm), 26 patients) vs. 30 control subjects. The patients were evaluated by a complete transthoracic echocardiographic examination including measurement of the aortic dimensions. RESULTS The serum UA concentration and total antioxidant reductive capacity were significantly higher in patients with AscAAs. In multiple linear regression analysis, hypertension and serum UA concentration were significantly associated with aortic dilatation (β = 0.3, P = 0.03; β = 0.15, P < 0.001, respectively). CONCLUSIONS In conclusion, we found that serum UA concentration and total antioxidant capacity (TAC) were significantly associated with aortic dilatation. The higher serum UA concentration may be responsible for the elevated serum antioxidant capacity that was observed among individuals with AscAA. Large-scale epidemiological studies conducted over several years are required to correlate the cross-sectional findings from this study with clinical outcome.

Plasma orexin A, ghrelin, cholecystokinin, visfatin, leptin and agouti-related protein levels during 6-week olanzapine treatment in first-episode male patients with psychosis.

The objective of the study was to investigate the change of body mass index (BMI), waist circumference, lipid profile, leptin, ghrelin, orexin, visfatin, agouti-related protein, and cholecystokinin levels during 6 weeks of olanzapine treatment in newly diagnosed first-episode drug naive, young adult, nonobese male patients with psychosis. Twenty male participants who were all first-episode drug naive psychotic patients without prominent affective signs and symptoms and 22 healthy male controls of similar age were included. BMI, waist circumference, fasting glucose, and lipid profiles were measured, and Positive and Negative Syndrome Scale and Brief Psychiatric Rating Scale scores were obtained at baseline, during the second and sixth week of treatment, and the aforementioned neuropeptide levels were measured at baseline and during the sixth week of treatment. Treatment was associated with significant increases in BMI, waist circumference, serum triglyceride, and low-density lipoprotein levels. BMI levels increased more than 7% in over 75% of the patients. Leptin increased, and ghrelin and orexin decreased significantly with olanzapine treatment, whereas cholecystokinin, visfatin, and agouti-related protein levels did not change significantly. In conclusion, consistent with previous studies, we found increased BMI, leptin and lipids during olanzapine treatment. Association of neuropeptide level changes with symptom improvement might be mediated by the dopaminergic and serotonergic systems.

Human diversity, environmental adaptation and neural crest

The relationship between anatomical/physiological traits, environmental adaptability and neural crest is described, and possible mechanisms leading to human diversity are suggested. It is concluded that environmental adaptation seems to be limited to those structures of neural crest origin.

Can procalcitonin predict bone infection in people with diabetes with infected foot ulcers? A pilot study

AIMS The diagnosis of osteomyelitis is a key step of diabetic foot management. Previous studies showed that procalcitonin (PCT), a novel infection marker, is superior to conventional infection markers in the diagnosis of diabetic foot infection. This study aimed to investigate the serum levels of PCT and other conventional infection markers in diabetic persons with and without osteomyelitis. METHODS Twenty-four patients (18 male, mean age: 61.9±10.8 years) with infected foot ulcers were prospectively enrolled. Clinical characteristics of the wounds were noted. Blood samples were obtained for biochemical analysis. Magnetic resonance imaging of the foot was performed in all patients to diagnose osteomyelitis. RESULTS Osteomyelitis was found in 13 of 24 (54%) patients. PCT levels were 66.7±43.5 pg/ml in patients with osteomyelitis and 58.6±35.5 pg/ml in patients without osteomyelitis. The difference did not reach statistical significance (p=0.627). Erythrocyte sedimentation rate, but not C-reactive protein and white blood cell count, was found significantly higher in patients with osteomyelitis. CONCLUSION In this group of patients, PCT failed to discriminate patients with bone infection. Erythrocyte sedimentation rate can be used as a marker of osteomyelitis in diabetic persons.

Plasma apelin and asymmetric dimethylarginine levels in type 2 diabetic patients with diabetic retinopathy.

Oxidative stress is thought to be one of the underlying mechanisms of diabetic microvascular complications such as diabetic nephropathy and diabetic retinopathy (DRP). Asymmetric dimethylarginine (ADMA) is an endogenous nitric oxide (NO) synthase inhibitor and increased by oxidative stress. Apelin is an endogenous ligand for human orphan G-protein-coupled receptor, APJ and increases NO generation. In this study, our aim was to evaluate ADMA and apelin levels in diabetic patients with or without retinopathy and their relationships between retinopathy stages and metabolic parameters. Seventy-nine diabetic patients were included into the study and classified into three groups. Group 1 consisted of 41 patients with no DRP (NDRP), group 2 consisted of 23 patients with nonproliferative DRP (NPDRP), and group 3 consisted of 15 patients with proliferative DRP (PDRP). Plasma ADMA and apelin levels were found to be similar in all groups. But, there was a positive correlation between apelin levels and urinary albumin/creatinine ratio. Further studies involving larger patients populations and healthy controls should be done to clarify the pathogenetic significance of ADMA and apelin in diabetic microvascular complications.

Altered red cell membrane compositions related to functional vitamin B12 deficiency manifested by elevated urine methylmalonic acid concentrations in patients with schizophrenia

Abstract Background Abnormal cell membrane composition and functional cobalamin (vitamin B12) deficiency was reported in schizophrenic individuals. We aimed to investigate the relationship between cobalamin state and cell membrane composition in patients with schizophrenia. Methods Malondialdehyde (MDA), cholesterol, and phospholipid classes in the erythrocyte membranes of 18 schizophrenic and 20 healthy individuals of the same age and sex distribution were determined. Serum vitamin B12, plasma total homocysteine, serum folate, and urine methylmalonic acid (uMMA) concentrations were measured in both groups. Results In the schizophrenic group, uMMA, membrane MDA, membrane cholesterol, membrane phosphatidylinositol concentrations were significantly higher and the membrane phosphatidylserine concentrations were lower than the control group values. In schizophrenic individuals, uMMA concentrations have a significant positive correlation with membrane MDA and a negative correlation with membrane cholesterol concentrations (P < 0.05). The negative correlation of uMMA with membrane cholesterol concentrations may be a biological response to the increased membrane rigidity. Also, a free radical elevation related to the elevated uMMA concentrations in the erythrocyte membrane, might reflect the role of methylmalonic acid (MMA) in membrane damage. Conclusion Our present findings suggest that, functional vitamin B12 deficiency representing itself by MMA elevations in schizophrenic individuals could damage cell membrane.

Effects of Alpha Tocopherol and Ascorbic Acid on Helicobacter pylori Colonization and the Severity of Gastric Inflammation

Background and Aim:  We aimed to evaluate the changes in histopathologic features, concentrations of vitamins C and E in gastric mucosa, and total antioxidant capacity of the body after ingestion of ascorbic acid and alpha tocopherol in patients with Helicobacter pylori.