Sevsen Kulaksizoglu

Serum total antioxidant status and lipid peroxidation marker malondialdehyde levels in overt and subclinical hypothyroidism

Background  Mitochondria are the main production site of free oxygen radicals, which can cause organ dysfunction by oxidation of cellular macromolecules such as carbohydrates, lipids and proteins. Oxidative stress may result from either overproduction of these species or from failure of the antioxidant defence systems. Thyroid hormones have well‐known effects on mitochondrial oxygen consumption, but data about how hypothyroidism affects oxidative stress are controversial, and little is known about oxidative stress in subclinical hypothyroidism. Total antioxidant status (TAS) gives information about all of the antioxidants in the organism, while malondialdehyde (MDA) is a lipid peroxidation marker used to assess lipid peroxidation due to increased oxidative stress. We aimed to determine how hypothyroidism and subclinical hypothyroidism affect serum MDA and TAS.

A Truncating Mutation in SERPINB6 Is Associated with Autosomal-Recessive Nonsyndromic Sensorineural Hearing Loss

More than 270 million people worldwide have hearing loss that affects normal communication. Although astonishing progress has been made in the identification of more than 50 genes for deafness during the past decade, the majority of deafness genes are yet to be identified. In this study, we mapped a previously unknown autosomal-recessive nonsyndromic sensorineural hearing loss locus (DFNB91) to chromosome 6p25 in a consanguineous Turkish family. The degree of hearing loss was moderate to severe in affected individuals. We subsequently identified a nonsense mutation (p.E245X) in SERPINB6, which is located within the linkage interval for DFNB91 and encodes for an intracellular protease inhibitor. The p.E245X mutation cosegregated in the family as a completely penetrant autosomal-recessive trait and was absent in 300 Turkish controls. The mRNA expression of SERPINB6 was reduced and production of protein was absent in the peripheral leukocytes of homozygotes, suggesting that the hearing loss is due to loss of function of SERPINB6. We also demonstrated that SERPINB6 was expressed primarily in the inner ear hair cells. We propose that SERPINB6 plays an important role in the inner ear in the protection against leakage of lysosomal content during stress and that loss of this protection results in cell death and sensorineural hearing loss.

Polycystic ovary syndrome is associated with elevated plasma soluble CD40 ligand, a marker of coronary artery disease

OBJECTIVE To determine the level of plasma soluble CD40 ligand (sCD40L) in patients with polycystic ovary syndrome (PCOS). DESIGN Prospective study. SETTING Baskent University School of Medicine in Turkey. PATIENT(S) Thirty-one patients with PCOS and 31 non-PCOS (control) patients. INTERVENTION(S) Determination of plasma sCD40L and homocysteine levels. MAIN OUTCOME MEASURE(S) Plasma sCD40L, fasting glucose, fasting insulin, homeostatic model assessment insulin resistance index (HOMA-IR), LH, FSH, E(2), total T, DHEAS, total cholesterol, high- and low-density lipoprotein cholesterol, triglyceride, homocysteine, and high-sensitivity C-reactive protein (hsCRP). RESULT(S) The mean serum fasting insulin and HOMA-IR levels were significantly higher in the PCOS group. The mean serum homocysteine level was significantly higher in the PCOS group. Despite a trend for higher high-sensitivity C-reactive protein levels in the PCOS group, the difference did not reach statistical significance. The mean plasma sCD40L level in the PCOS group was significantly higher than that in the control group (5.14 +/- 3.65 ng/mL vs. 3.45 +/- 2.64 ng/mL, respectively). CONCLUSION(S) Polycystic ovary syndrome is associated with elevated levels of sCD40L and homocysteine.

Aqueous humor and plasma levels of vascular endothelial growth factor and nitric oxide in patients with pseudoexfoliation syndrome and pseudoexfoliation glaucoma.

PurposeTo investigate levels of vascular endothelial growth factor (VEGF) and nitric oxide (NO) in the aqueous humor and plasma of patients with pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG), compared with controls. MethodsThis prospective study involved 37 patients with PXS, 15 with PXG, and 32 control subjects in whom cataract surgery was indicated. Aqueous humor and plasma VEGF and NO levels were measured with enzyme-linked immunosorbent assay and chemiluminescence methods, respectively. ResultsAqueous humor and plasma VEGF concentrations were higher in patients with PXS and PXG than in controls (P<0.001). Aqueous humor NO concentrations were higher in patients with PXS and PXG than in controls (P<0.05 and P=0.001, respectively). Plasma NO concentrations did not differ between the 3 groups. Aqueous humor and plasma VEGF and NO levels were not significantly different in patients with PXS versus PXG. VEGF and NO levels showed no significant correlation among the 3 groups (P>0.05). ConclusionsElevated aqueous humor VEGF and NO levels and plasma VEGF concentrations in eyes with PXS and PXG can be explained by the ischemic nature of these disorders. The lack of correlation between VEGF and NO levels may indicate impaired downregulation, which may have a role in the progression to PXG.

Elevated serum uric acid levels impair coronary microvascular function in patients with idiopathic dilated cardiomyopathy

In patients with idiopathic dilated cardiomyopathy (IDC), attenuated coronary flow reserve (CFR) and elevated serum uric acid levels have been reported. In this study, we investigated whether increased uric acid levels correlate with the degree of coronary microvascular dysfunction.

Rigorous Bicycling Does Not Increase Serum Levels of Total and Free Prostate-specific Antigen (PSA), the Free/Total PSA Ratio, Gonadotropin Levels, or Uroflowmetric Parameters

OBJECTIVES To determine whether cycling has an effect on serum PSA, gonadotropins, and uroflowmetric parameters. METHODS A total of 34 healthy male athletes from the National Cycling Team and 24 healthy male student volunteers from University and medical staff were prospectively enrolled in the study. Blood samples for serum total prostate-specific antigen (tPSA), free PSA (fPSA, fPSA/tPSA, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone determinations were obtained before and after cyclists completed 300 km bicycle ride and with each cyclist seated without changing posture and with minimal movement for 10 minutes before blood collection. The cyclists also performed uroflowmetric and postvoid residual urine volume analysis before, and 1 hour after cycling course. Blood samples from the control group were drawn for serum hormones. They also underwent uroflowmetric and postvoid residual analysis. RESULTS The athletes and the control group were well matched by age. There was no significant difference between the 2 groups in terms of serum tPSA, fPSA, f/t PSA values, FSH, LH, and testosterone levels and uroflowmetric parameters (P >.05). The differences between pre- and postcycling values for tPSA, fPSA, f/t PSA, FSH, LH, and uroflowmetric parameters were not statistically significant. The postcycling serum testosterone level was significantly lower than precycling levels (mean, 603.6 ng/dL [range, 300-949] vs 424.8 ng/dL [range, 193-723], P = .001]. There was no correlation between body mass index values, postcycling serum FSH, LH levels, age, and testosterone levels. CONCLUSIONS There is no effect of professional bicycle riding on serum total and fPSA levels and uroflowmetric parameters.

Impact of various modifiers on calcium oxalate crystallization

Objective:  This work focuses on the behavior of in vitro calcium oxalate crystallization. The effects of several compounds on the kinetics of calcium oxalate crystallization were examined.

Aqueous Humour and Serum Levels of Nitric Oxide, Malondialdehyde and Total Antioxidant Status in Patients with Type 2 Diabetes with Proliferative Diabetic Retinopathy and Nondiabetic Senile Cataracts.

OBJECTIVES Diabetic retinopathy is associated with enhanced oxidative stress and/or reduction of antioxidant status. Several studies have examined the oxidative agents, such as nitric oxide (NO) and malondialdehyde (MDA), in the body fluids of patients with diabetes. However, total antioxidant status (TAS) in the aqueous humour of patients with diabetes has not been determined to date. To address this issue, we analyzed the aqueous humour and serum levels of NO, MDA and TAS in patients with type 2 diabetes and nondiabetic senile cataracts. METHODS This prospective study included 35 patients with type 2 diabetes and 35 age- and sex-matched healthy subjects in whom cataract surgery was indicated. Aqueous humour and serum MDA, NO and TAS levels were determined by spectrophotometric methods, respectively. RESULTS The analysis of MDA levels in the serum and aqueous humour revealed no significant differences in any of the groups (p>0.05). At the level of aqueous humour, patients with type 2 diabetes had significantly increased NO levels, compared to the controls (p=0.003). The control group also presented significantly higher TAS levels than the subgroup with type 2 diabetes in serum (p=0.001). However, there were no significant differences in the TAS levels of aqueous humour and serum NO levels in the groups (p>0.05). CONCLUSIONS Our results seem to demonstrate that the development of diabetic retinopathy is associated with high levels of aqueous humour NO and reduced serum antioxidant defenses. Therefore, inhibition of reactive oxygen species production and substitution of serum antioxidant status may be a therapeutic target for eye diseases associated with oxidative stress.

Oxidative stress and nasal polyposis: does it affect the severity of the disease?

Background Nasal polyposis (NP) is a chronic inflammatory disease and the waste products of this inflammation are reactive oxygen species composed of free radicals. Changes in oxidative status have already been revealed in NP. The aim of this study was to investigate the effect of oxidative status to the severity of the disease and the quality of life. Methods The study group included 24 patients with NP and 20 controls. The Turkish version of the Rhinosinusitis Disability Index, visual analog scale (VAS), polyp stage, computed tomography (CT) score, and the eosinophilic cationic protein (ECP) levels in nasal lavage (NAL) fluid were used to assess the severity of the disease. Malondialdehyde, nitric oxide (NO), and the total antioxidant status (TAS) levels in NAL fluids were measured representing the oxidative stress. Results NO values were correlated with nasal congestion (p = 0.031). TAS values were correlated with nasal obstruction (p = 0.039). ECP values showed correlation with all the nasal obstruction (p = 0.003), congestion (p = 0.009), rhinorrhea (p = 0.009), and VAS scores (p = 0.039). Conclusion In NP, ECP levels detected in NAL fluid were significantly high and were correlated with the severity of the disease. Moreover, the severity of oxidative stress, in the forms of TAS and NO, is significantly correlated with the severity of the nasal obstruction and congestion, respectively.

Can first-trimester screening program detect women at high risk for gestational diabetes mellitus?

This study was designed to compare first-trimester maternal serum biochemical markers of aneuploidy and fetal nuchal translucency in pregnancies complicated by gestational diabetes mellitus and those of a control group. The study included 60 gestational diabetic and 60 control women who attended the first-trimester combined screening program for Down syndrome between 11 and 14 gestational weeks with complete follow-up data and delivered in our institution. Maternal serum free β-human chorionic gonadotropin, pregnancy-associated plasma protein-A and fetal nuchal translucency were investigated. The combined risks, double test risks and age risks were calculated by PRISCA software version 4.0. Comparison of the results between the two groups yielded no significant differences in serum levels of free β-human chorionic gonadotropin and fetal nuchal translucency. However, women who developed gestational diabetes mellitus had significantly lower pregnancy-associated plasma protein-A. And also, the combined risks and double test risks calculated by PRISCA software were statistically higher in gestational diabetic women than normal pregnant women. These results suggest that differences can be seen between diabetic and healthy pregnant women in first-trimester maternal serum biochemical markers of aneuploidy.