Biomedical subjects

Taner Ozgurtas

Publications and source records attributed to Taner Ozgurtas.

15 recordsLinked to original sources

PubMed2006

Plasma visfatin levels in patients with newly diagnosed and untreated type 2 diabetes mellitus and impaired glucose tolerance.

Visfatin, a new adipokine, facilitates adipogenesis and has insulin-mimetic properties. We aimed to investigate the plasma visfatin levels in patients with newly diagnosed and untreated type 2 diabetes mellitus (T2DM) and impaired glucose tolerance (IGT), who had no obesity or hypertension. Twenty-two patients with T2DM, 18 subjects with IGT and 40 healthy controls were enrolled. Visfatin levels were measured along with the BMI, blood pressure, lipids, glucose, insulin, adiponectin and hsCRP levels, and HOMA-IR indexes. Age, sex and BMI were similar in all groups. Visfatin levels were higher in the diabetic group than the controls (p=0.01). There was no significant difference in the visfatin levels between the T2DM and IGT groups as well as IGT group and healthy controls. Plasma visfatin concentrations did not differ between men and women. Visfatin levels did not correlate with BMI, blood pressure, plasma adiponectin, insulin, hsCRP, glucose and lipid levels or HOMA-IR indexes in the three groups. These results indicate that hyperglycemia causes an increase in plasma visfatin levels and, as in people with T2DM but not with IGT, this increase gets more prominent as the glucose intolerance worsens.

Adult↗

PubMed2006

Adiponectin and insulin resistance in young and healthy smokers.

Smoking is closely associated with insulin resistance, though the mechanism is not clear. Adiponectin, a novel anti-atherosclerotic and anti-inflammatory adipose tissue product, which is closely associated with insulin resistance, was reported to be low in smokers with cofactors for atherosclerosis. However, the effects of smoking on circulating adiponectin levels in otherwise healthy people are unknown. In this study, a case control design was implemented to search for the effect of smoking on plasma adiponectin and insulin sensitivities in healthy people. Sixty-four healthy male smokers, with no family history of hypertension and diabetes mellitus were compared with appropriate 36 age and body mass index matched controls. Both the patients and controls were the soldiers of a troop with regular daily physical activity. Plasma adiponectin, high sensitive C-reactive protein (hsCRP), insulin and lipid levels, and insulin sensitivity as assessed by homeostasis model assessment index (HOMA) of the smokers were measured and compared with those of the controls. The plasma adiponectin, hsCRP, insulin levels and HOMA indexes of the two groups were similar. These parameters were not affected by the amount of cigarettes per day. HDL-cholesterol levels were lower (p = 0.01) and systolic blood pressures were higher (p = 0.02) in the smokers. These results indicate that smoking may not affect plasma adiponectin and insulin levels in young and healthy men with high exercise capacity.

Adiponectin↗

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

The effect of fluvastatin on plasma adiponectin levels in dyslipidaemia.

OBJECTIVE: There is controversy about the effects of statins on insulin resistance and plasma adiponectin. The aim of this study was to investigate the effects of fluvastatin treatment on these parameters in a group of dyslipidaemic patients who had no confounding factors for insulin resistance or alterations in plasma adiponectin. DESIGN AND PATIENTS: Forty-nine patients [27 males, 22 females; mean age 47.2 +/- 10.3 years; body mass index (BMI) 29.64 +/- 3.2 kg/m2] with dyslipidaemia and 20 controls (six males, 14 females; mean age 45.3 +/- 9.31 years; BMI 30.07 +/- 4.04 kg/m2) were enrolled. All patients were treated initially with therapeutic lifestyle changes (TLC) for 6 weeks. Six out of 49 subjects were excluded from the study. Then, 24 out of 43 patients with high blood cholesterol despite TLC were allocated to fluvastatin 80 mg daily plus TLC, and the remaining 19 patients with normal cholesterol were subjected to TLC alone for additional 12 weeks. MEASUREMENTS: Plasma adiponectin, immunoreactive insulin levels, BMI, waist circumference, blood pressure, lipids, and glucose were determined. The insulin sensitivity index was quantified using the homeostasis model assessment (HOMA). RESULTS: TLC caused significant improvement in plasma insulin (P = 0.02) and elevation in plasma adiponectin (P = 0.02). Fluvastatin treatment decreased total cholesterol and low density lipoprotein (LDL)-cholesterol significantly (P = 0.01 and P = 0.02, respectively). No significant effect of fluvastatin was observed on plasma insulin or adiponectin or on the HOMA index. CONCLUSIONS: Fluvastatin does not improve plasma adiponectin levels and insulin sensitivity, despite its beneficial effects on lipid levels. Our data, however, were limited by the fact that a more accurate method of assessing insulin sensitivity, the euglycaemic-hyperinsulinaemic glucose clamp technique, was not used.

Adiponectin↗

PubMed2006

Plasma adiponectin and insulin resistance in new onset hypertension.

OBJECTIVE: The data related to association among hypertension, insulin resistance, and plasma adiponectin concentration is controversial. We aimed to evaluate the relationships among these factors in a young hypertensive group who had no confounding factors. DESIGN AND METHODS: Thirty newly diagnosed and formerly untreated hypertensive males (mean age 23.4 +/- 4.0 yr; body mass index: 24.9 +/- 2.2 kg/m2), and 60 healthy control subjects (mean age 22.5 +/- 3.2 yr; body mass index: 24.6 +/- 1.6 kg/m2) were enrolled. Insulin resistance was calculated by homeostasis model assessment (HOMA). RESULTS: The two groups were similar in terms of age, body mass index, fasting glucose, total cholesterol, HDL and LDL cholesterol, adiponectin, insulin, HOMA, and hsCRP levels. Mean triglyceride levels in hypertensive patients were significantly higher than the controls (p = 0.02). CONCLUSIONS: These results indicate that young, newly diagnosed, uncomplicated patients with hypertension have similar plasma adiponectin levels and insulin sensitivities when compared to healthy controls. We suggest that high blood pressure itself may not be associated with insulin resistance or low adiponectin levels in patients with new onset, uncomplicated hypertension.

Adiponectin↗

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↗

PubMed2004

Transient hypogonadotrophic hypogonadism in males with acute toxoplasmosis: suppressive effect of interleukin-1 beta on the secretion of GnRH.

BACKGROUND: In September 2002, an outbreak of toxoplasmosis was noted in a male boarding high school on the Aegean coast of Turkey. We have focused our efforts to investigate the sex hormones in this population. METHODS: Blood samples were collected from 40 male patients, 17-18 years old, who also had positive titres of antibody to Toxoplasma gondii. Serum FSH, LH, free testosterone (FT), total testosterone (TT), interferon-gamma (IFN-gamma), interleukin-1beta (IL-1beta) and macrophage-inflammatory protein-1alpha (MIP-1alpha) concentrations were measured in all patients and 20 control subjects. Initially, the patients were divided on the basis of the levels of sex hormones into the following groups: patients who had normal sex hormone levels (n = 31) as group A and patients with low sex hormone levels (n = 9) as group B. RESULTS: IL-1beta levels were found to be higher in group B patients than group A. The levels of IL-1beta correlated significantly in a negative manner with FSH, LH, FT and TT in all patients with acute toxoplasmosis (n = 40). CONCLUSIONS: Acute toxoplasma infection may cause temporary hypogonadotrophic gonadal insufficiency regardless of the course of the disease.

Acute Disease↗

PubMed2004

Role of urinary zinc and copper on calcium oxalate stone formation.

INTRODUCTION: It is considered that many factors may play a role in urolithiasis. Experimental and clinical studies have shown that zinc has an inhibitory effect on urolithiasis. MATERIALS AND METHODS: In this study, urinary zinc and copper were measured in 27 healthy controls and 30 calcium oxalate stone formers. RESULTS: Urinary zinc excretion was significantly higher (p < 0.001) in stone formers than healthy controls (2,575 +/- 274 and 960 +/- 80 mg/day, respectively). There was no significant difference in urinary copper excretion between healthy controls and stone formers (32.3 +/- 3.5 and 33.3 +/- 3.2 microg/day, respectively). CONCLUSIONS: According to our results, the potent inhibitory effect of urinary zinc excretion on urolithiasis could be reviewed.

Adult↗

PubMed2003

Is high concentration of serum lipids a risk factor for Achilles tendon rupture?

BACKGROUND: The incidence of the Achilles tendon ruptures (ATR) seems to be increasing due to changes in life style and intensified sports activities in recent years. Intrinsic and extrinsic factors have been implicated as predisposing risk factors to rupture. The purpose of this study was to investigate whether the high serum lipid concentrations could be an intrinsic factor in patient with complete ruptures of Achilles tendon. METHODS: The data were collected from the records of 47 patients with complete rupture of Achilles and the control group consisted of 26 subjects. RESULTS: Total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) concentrations of the patients with ATR were higher (p<0.001), and their high-density lipoprotein cholesterol (HDL-C) was lower than the control group (p<0.05). Moreover, the concentrations of triglyceride (TG) and very low-density lipoprotein cholesterol (VLDL-C) were significantly higher than controls (p<0.05). CONCLUSIONS: The causes of ATR are multifactorial and still unclear. However, high serum lipid concentrations might be considered, as a predisposing factor in patients with complete rupture of Achilles tendon and further investigations with larger groups would be better.

Achilles Tendon↗

PubMed2003

Monitoring of serum ionized magnesium in neurosurgical intensive care unit: preliminary results.

BACKGROUND: Our purpose was to determine the values for serum ionized magnesium (Mg) concentrations in traumatic brain injury and its effect on the prognostic scores of patients. METHODS: We prospectively measured serum ionized magnesium concentrations in 30 patients that were classified into three groups (severe, moderate, mild) by Glasgow Coma Scale Score. Serum ionized magnesium concentrations were measured during posttraumatic 5 days. Thirty patients with head trauma were followed in a neurosurgical intensive care unit with monitoring serum ionized magnesium concentrations. All patients were treated conservatively. RESULTS: We found significant difference of serum ionized magnesium concentrations when we compared all groups with each other (p<0.001). CONCLUSIONS: Based on this clinical preliminary study, traumatic brain injury is associated with graded deficit in serum ionized magnesium concentrations. Thus, measurement of serum ionized magnesium concentrations can be used as a clinical marker in traumatic brain injury.

Adult↗

PubMed2003

Renal tubular dysfunction in beta-thalassemia minor.

BACKGROUND: Persons with beta-thalassemia minor usually are symptomless. However, we previously reported renal tubular dysfunction in a patient with beta-thalassemia minor. The aim of this study is to investigate renal function in patients with beta-thalassemia minor. METHODS: Forty-one subjects with beta-thalassemia minor and 20 sex- and age-matched healthy subjects were enrolled in the study. For analysis, patients were divided into 2 groups: group A, all patients with anemia (n = 19), and group B, patients without anemia (n = 22). Blood and 24-hour urine samples were obtained for hematologic and biochemical analysis. RESULTS: Anemic patients had increased urinary zinc excretion (U(zinc)) and fractional excretion of sodium (FE(Na)) and uric acid (FE(UA)) compared with both controls and patients without anemia. Hemoglobin levels correlated significantly in a negative manner with U(zinc), FE(Na), and FE(UA) in patients with beta-thalassemia minor. However, serum lactate dehydrogenase levels correlated significantly in a positive manner with the same parameters. In addition, 6 of 41 patients (14.6%) with beta-thalassemia minor showed significant signs of renal tubulopathy, such as hypercalciuria, decreased tubular reabsorption of phosphorus with hypophosphatemia, hypomagnesemia with renal magnesium wasting, hypouricemia with renal uric acid wasting, and tubular proteinuria. CONCLUSION: Proximal renal tubular dysfunction is not rare in patients with beta-thalassemia minor.

Adult↗

PubMed2003

Involvement of nitric oxide and hyperbaric oxygen in the pathogenesis of cyclophosphamide induced hemorrhagic cystitis in rats.

PURPOSE: We evaluated the relationship between nitric oxide and hyperbaric oxygenation in the pathogenesis and treatment of cyclophosphamide induced hemorrhagic cystitis in rats. MATERIALS AND METHODS: Cyclophosphamide (100 mg/kg) was injected in male Sprague-Dawley rats for cystitis induction. Animals were treated before and the day after cyclophosphamide injection with 100 mg/kg of the nitric oxide substrate L-arginine, 20 mg/kg of the nonselective nitric oxide synthase inhibitor L-NG-nitroarginine methyl ester and 20 mg/kg of the selective inducible nitric oxide synthase inhibitor S-methylisothiourea. Animals were exposed to hyperbaric oxygen (2.8 atmospheres absolute for 90 minutes twice daily) with or without the administration of L-arginine and nitric oxide synthase inhibitors. RESULTS: Cyclophosphamide injection resulted in severe cystitis. S-methylisothiourea produced marked inhibition of cyclophosphamide induced bladder tissue damage. L-arginine and L-NG-nitroarginine methyl ester failed to a show meaningful protective effect. Hyperbaric oxygen protected the bladder only against ulceration. Moreover, hyperbaric oxygen did not contribute to the protective effects of L-arginine, L-NG-nitroarginine methyl ester or S-methylisothiourea. CONCLUSIONS: Nitric oxide produced by inducible nitric oxide synthase is an important mediator in the pathogenesis of cyclophosphamide induced cystitis. Hyperbaric oxygen has a beneficial effect on repairing bladder damage rather than on bladder protection.

Animals↗

PubMed2003

Do spinal cord injuries adversely affect serum lipoprotein profiles?

OBJECTIVES: Previous reports indicate that dyslipidemia is very common in persons with spinal cord injury. This study aimed to examine the relationship between spinal cord injury and serum lipoprotein profiles. METHODS: We assessed 28 healthy control subjects matched for age and sex and 60 persons (46 men and 14 women; mean age, 28.1 years) with spinal cord injury having a mean duration of injury of 3.6 +/- 0.8 years (range, 1-13 years). RESULTS: Serum low-density lipoprotein cholesterol level was higher (109 +/- 37, 91 +/- 23.7 mg/dL, respectively) (p = 0.04) and serum high-density lipoprotein cholesterol level was lower (33 +/- 7.1, 44 +/- 7.4 mg/dL, respectively) (p < 0.001) in the patients with spinal cord injury than in the control. Apolipoprotein A-I level was significantly low (94 +/- 10.3, 103 +/- 11.5 mg/dl) (p = 0.003) and apolipoprotein B level was significantly high (93 +/- 15.6, 81 +/- 13.7mg/dL) (p = 0.004) in the group of spinal cord injury. No significant difference was observed the other parameters of these two groups. CONCLUSION: Our results have shown that serum lipoprotein level should not be ignored for the follow-up of the patients with spinal cord injury.

Adult↗

PubMed2002

Increased fasting plasma acylation-stimulating protein concentrations in nephrotic syndrome.

Acylation-stimulating protein (ASP) is an adipocyte-derived protein that has recently been suggested to play an important role in the regulation of lipoprotein metabolism and triglyceride (TG) storage. ASP also appears to have a role in the regulation of energy balance. In addition to its role as a hormonal regulator of body weight and energy expenditure, leptin is now implicated as a regulatory molecule in lipid metabolism. However, little is known about the alterations in fasting plasma ASP and leptin concentrations in the nephrotic syndrome. As hyperlipidemia is one of the most striking manifestations of the nephrotic syndrome, we have investigated fasting plasma ASP and leptin levels and their relation to lipid levels in this syndrome. Twenty-five patients with untreated nephrotic syndrome and 25 age-, sex-, and body mass index-matched healthy controls were included in the study. Fasting plasma lipoproteins, TG, total cholesterol, lipoprotein(a), apolipoprotein AI (apoAI), apoB, urinary protein, plasma albumin, third component of complement (C3), ASP, and leptin levels were measured in both groups. Total cholesterol, TG, low and very low density lipoproteins, lipoprotein(a), apoB, and urinary protein levels were increased in the patient group, whereas plasma albumin, high density lipoprotein cholesterol, and apoAI levels were decreased compared with those in the control group (P < 0.001). Plasma ASP levels were significantly higher in the patient group compared with the control subjects (133.72 +/- 65.14 vs. 29.93 +/- 12.68 nmol/liter; P < 0.001), whereas leptin (2.69 +/- 2.06 vs. 3.99 +/- 2.99 ng/ml; P = 0.118) and C3 (1.01 +/- 0.25 vs. 1.06 +/- 0.23 g/liter; P = 0.662) levels were not significantly different between the two groups. Plasma leptin levels were correlated with body mass index in both nephrotic patients (r(s) = 0.86; P < 0.001) and controls (r(s) = 0.98; P < 0.001), but were not correlated with the other parameters. Fasting ASP concentrations showed no correlation with body mass index, proteinuria, plasma albumin, leptin, or any lipid parameter in either group, but C3 levels (in patient group: r(s) = 0.92; P < 0.001; in control group: r(s) = 0.68; P < 0.001). Our findings showed that plasma ASP levels were significantly elevated, whereas leptin levels were normal in the nephrotic syndrome. Increased ASP levels in the setting of dyslipidemia in the nephrotic syndrome raise the possibility of an ASP receptor defect in adipocytes, which also suggests the existence of so-called ASP resistance. Moreover, it is possible that ASP activity is maximal, but cannot keep up with increased rates of lipid production by the liver. Thus, further studies are needed to elucidate the mechanism or source (adipocytes, the liver, or both) of elevated ASP concentrations in the nephrotic syndrome.

Adolescent↗

PubMedDate not supplied

Preoperative and postoperative administration of hyperbaric oxygen improves biochemical and mechanical parameters on ischemic and normal colonic anastomoses.

Colonic anastomotic leaks are a major postoperative complication, causing increased mortality and morbidity. Tissue ischemia is one of the most important factors that disrupt anastomotic healing. It is possible to reverse inadequate tissue oxygenation by using increased atmospheric pressure and hyperoxia, which are obtained from hyperbaric oxygen treatment (HBO). Our aim was to investigate the effects of preoperative and postoperative HBO treatment on normal and ischemic colonic anastomoses in rats. Eighty male Wistar Albino rats, weighing between 180 and 240 g, were divided into 8 equal groups. A 1-cm segment of left colon was resected 3 cm proximal to the peritoneal reflection in all groups and colonic anastomosis was performed. In groups 2, 4, 6 and 8, colonic ischemia was established by ligating 2 cm of mesocolon on either side of the anastomosis. Control groups (1 and 2) received no HBO. HBO treatment was given preoperatively in groups 3 and 4, postoperatively in groups 5 and 6, and both preoperatively and postoperatively in groups 7 and 8. HBO treatment was applied for 2 days in the preoperative period and 4 days in the postoperative period. Relaparotomy was performed on postoperative day 5 and a perianastomotic colon segment 2 cm in length was excised for detection of biochemical and mechanical parameters of anastomotic healing and histopathological evaluation. HBO treatment increased tissue hydroxyproline levels in all groups, and this difference was significant in normal anastomosis groups receiving preoperative HBO compared to controls (p = .013 for group 1 vs. group 3; p = .023 for group 1 vs. group 5). This improvement was more evident in ischemic and normal groups treated by administration of combined pre- and postoperative HBO (p = .021 and p = .013). HBO treatment also increased the mean bursting pressure values in all groups, and again, a statistically significant increase was noted in the ischemic groups compared to controls (p = .002 for group 2 vs. group 6; p = .001 for group 2 vs. group 8). Histopathological evaluation of anastomotic line fibrosis was not found to show significant differences between the groups. Adequate tissue oxygenation is the main factor in wound and anastomosis healing. HBO treatment has a positive effect on biochemical and mechanical parameters of ischemic and normal colon anastomoses in rats. It is possible to see this effect more clearly with combined HBO treatment applied before and after ischemic anastomosis.

Anastomosis, Surgical↗