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Dive into the research topics where Taner Bayraktaroglu is active.

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Featured researches published by Taner Bayraktaroglu.


Digestive Diseases and Sciences | 2005

The effect of Helicobacter pylori on insulin resistance.

Selim Aydemir; Taner Bayraktaroglu; Mehmet Sert; Coşkun Sökmen; Hulusi Atmaca; Gorkem Mungan; Banu Dogan Gun; Ali Borazan; Yucel Ustundag

Helicobacter pylori causes a lifelong infection in the stomach after exposure. H. pylorihas been shown to be associated with peptic ulcer and gastric cancer development. Moreover, it is held responsible for some other nongastric diseases. Among them, coronary heart disease attracts much debate. Many studies have demonstrated a close relationship between insulin resistance and atherosclerosis. Chronic inflammation and alterations in counter-regulatory hormones are deemed responsible for the etiology of insulin resistance. We aimed to examine the effect of H. pylori on insulin resistance. Sixty-three patients were enrolled in the study. Patients were divided into two groups according to H. pylori presence. HOMA-IR (homeostasis model assessment of insulin resistance) level was used to assess insülin resistance. Thirty-six patients were H. pylori positive and 27 were H. pylori negative. There was no difference between the two groups with regard to age, gender, or body mass index. HOMA-IR level was 1.73± 1.1 in the H. pylori-negative group, whereas it was 2.56 ± 1.54 in the H. pylori-positive group (P < 0.05). This study provides the first direct evidence for an association between chronic H. pylori infection and insulin resistance.


Mediators of Inflammation | 2004

The effects of peritoneal dialysis and hemodialysis on serum tumor necrosis factor-alpha, interleukin-6, interleukin-10 and C-reactive-protein levels.

Ali Borazan; Hasan Üstün; Yucel Ustundag; Selim Aydemir; Taner Bayraktaroglu; Mehmet Sert; Ahmet Yilmaz

BACKGROUND: Markers of an acute phase reaction, such as C-reactive protein (CRP) or tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-6, are predictive for cardiovascular morbidity and mortality in normal subjects and in chronic renal failure patients. In this study, we aimed to investigate serum TNF-alpha, IL-6, IL-10 and CRP levels in continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis (HD) patients. MATERIALS AND METHODS: Serum levels of TNF-alpha, IL-6, IL-10 and CRP levels were measured in 30 patients who were just diagnosed with end-stage renal failure and treated, with 16 CAPD (nine female, seven male) and 14 HD (eight female, six male) patients, before CAPD or HD treatment and after 3 months from the beginning of CAPD or HD in patients with no clinical signs of infection. The control groups were 20 healthy persons of similar age and sex. Serum levels of TNF-alpha, IL-6, IL-10 and CRP were measured by enzyme-linked immunosorbent assay in stable CAPD and HD patients and in healthy persons. RESULTS: The mean serum levels of TNF-alpha, IL-6, IL-10 and CRP showed no significant differences between the CAPD and HD patients for the beginning values and the third month of treatment. However, serum TNF-alpha, IL-6, IL-10 and CRP levels were higher than the control group in the CAPD and HD patients regarding the beginning values and the third month of treatment (p < 0.001). CONCLUSIONS: CAPD and HD of the renal replacement therapy have no effects on serum CRP and cytokines.


Mediators of Inflammation | 2004

Serum levels of tumor necrosis factor-α, interleukin-6 and interleukin-8 are not increased in dyspeptic patients with Helicobacter pylori-associated gastritis

Taner Bayraktaroglu; Ahmet Şükrü Aras; Selim Aydemir; Can Davutoğlu; Yucel Ustundag; Hulusi Atmaca; Ali Borazan

INTRODUCTION: Helicobacter pylori (H. pylori) is a non-invasive microorganism causing intense gastric mucosal inflammatory and immune reaction. H. pylori-induced gastric mucosal cytokine overproduction has been clearly documented previously. The stomach has a large surface area and continuous spill-over of locally produced cytokines into the blood stream is a possibility. There are few and conflicting data on circulatory proinflammatory cytokine levels in patients with H. pylori infection. MATERIALS AND METHODS: Forty-two dyspeptic patients were enrolled into the study. The presence of H. pylori infection was diagnosed with antral histopathologic examination. After overnight fasting; serum samples were obtained from each patient to determine circulating interleukin (IL)-6, IL-8 and tumor necrosis factor-alpha (TNF-alpha) levels. RESULTS: H. pylori was shown in 30 cases using Giemsa stain in antral histopathologic evaluation. Twelve cases were negative for H. pylori staining. Both the age and sex distribution had an insignificant difference in both H pylori-positive and H. pylori-negative groups. The mean circulatory levels of IL-6, IL-8 and TNF-a in both groups were not different. The situation was same in respect to the serum levels of these cytokines and the degree of inflammation, H. pylori density and activation scores according to Sydney classification. CONCLUSION: We could not show elevated circulatory levels of IL-6, IL-8 and TNF-alpha in H. pylori-infected cases. We believe that H. pylori-related cytokine activation become concentrated on gastric mucosa and this pathogen-induced local inflammatory cascade does not cause changes in circulatory levels of these cytokines. Moreover, there is no correlation between the levels of serum cytokines and Sydney parameters.


International Journal of Clinical Practice | 2005

Effect of hyperthyroidism and propylthiouracil treatment on liver biochemical tests

Selim Aydemir; Taner Bayraktaroglu; Nejat Demircan; Mehmet Sert; Serefden Acikgoz; Ishak Ozel Tekin; Yucel Ustundag

Liver biochemical test (LBT) changes can be commonly observed in hyperthyroid patients. Those kinds of changes could also be observed because of propylthiouracil (PTU) therapy. We prospectively evaluated LBT changes because of PTU use for 1 year in patients who had been diagnosed with hyperthyroidism first. We studied 64 patients who had been diagnosed with hyperthyroidism. These patients took at least 1‐year PTU treatment. We analysed LBT at diagnosis and after 2 and 12 months of treatment with PTU. Prior to PTU treatment, 30 (46.8%) of the 64 patients had at least one LBT abnormality. We observed at least one LBT abnormality in 11 (32%) patients after 2 months and nine (26%) patients after 12 months of treatment with PTU in 34 patients whose CBT were normal before treatment. We did not observe any deterioration in clinical picture and bilirubin levels. Elevated serum LBT during the pretreatment and PTU treatment period is common and usually transient and asymptomatic. PTU could be used for long times by lowering the dose and close follow‐up in patients who have elevated LBT during the pretreatment and after PTU treatment period.


Clinical Endocrinology | 2015

Characterization of the molecular genetic pathology in patients with 11β‐hydroxylase deficiency

Christiaan F. Mooij; Silvia Parajes; Ian T. Rose; Angela E. Taylor; Taner Bayraktaroglu; John Wass; John M. Connell; David Ray; Wiebke Arlt; Nils Krone

Steroid 11β‐hydroxylase (CYP11B1) deficiency (11OHD) is the second most common form of congenital adrenal hyperplasia. Nonclassic or mild 11OHD appears to be a rare condition. Our study assessed the residual CYP11B1 function of detected mutations, adding to the spectrum of mild 11OHD, and illustrates the variability of the clinical presentation of 11OHD.


Immunological Investigations | 2016

Increased Serum Levels of IL-28 and IL-29 and the Protective Effect of IL28B rs8099917 Polymorphism in Patients with Hashimoto’s Thyroiditis

Dilek Arpaci; Sevim Çelik; Murat Can; Gunes Cakmak Genc; Fatih Kuzu; Mustafa Unal; Taner Bayraktaroglu

ABSTRACT Hashimoto’s thyroiditis (HT) is thought to result from decreased T helper type 2 (Th2) responses, leading to the progressive destruction of thyrocytes. IFN-λ1, -λ2, and -λ3 (also known as IL-29, IL-28A, and IL-28B, respectively) are recently described members of the IFN-λ family and have been shown to decrease the production of Th2 cytokines in vitro. However, the role and mechanism of IFN-λ1 in HT remain unknown. The purpose of this study was to examine whether IL29 and IL28B gene polymorphisms are susceptibility genes for the development of HT. Also, we investigated the effects of IL-29 and IL-28 serum levels in the pathogenesis of HT. Using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, single-nucleotide polymorphisms (SNPs) of IL28B rs8099917 (IL28 G/T) and IL29 rs30461 (IL29 T/C) were studied in 99 patients with HT and 100 healthy controls. Considering the allelic distribution of the IL28 G/T polymorphism, a higher frequency of the G allele was observed in the control group versus the HT group. Thus, it was suggested that the G allele may be protective against HT pathogenesis (OR = 0.388, 95% CI = 0.217–0.693; p = 0.001). Our findings also demonstrated that there was a statistically significant difference in serum IL-28 and IL-29 levels between case and control groups (p < 0.001). Increased serum levels of IL-28 and IL-29 were found in patients with HT. However, we did not find a relationship between the IL29 gene polymorphism and HT. In conclusion, the IL28B gene polymorphism and serum IL-28 and IL-29 levels seem to play a role in the pathogenesis of HT.


Clinical Laboratory | 2016

Assessment of Mean Platelet Volume and its Effect on Disease Control in Patients with Acromegaly.

Dilek Arpaci; Fatih Kuzu; Mustafa Unal; Sevil Uygun Ilikhan; Mustafa Buyukuysal; Taner Bayraktaroglu

BACKGROUND Morbidity and mortality rates due to cardiovascular diseases are more common in acromegalic patients than the healthy population. Platelets play a significant role in both the onset and progression of clotting which then cause the development of atherosclerotic plaques. Increased mean platelet volume (MPV) is an indicator of platelet activation and known as an independent risk factor for atherosclerotic processes. The aim of this study was to compare MPV levels between acromegalic and non-acromegalic patients. METHODS The data of 56 acromegalic patients and 72 controls matched for age, gender, and the presence of diabetes were retrospectively reviewed. RESULTS MPV levels were found to be higher in acromegalic patients compared to controls (8.82 ± 1.17 fL and 7.74 ± 0.87 fL, respectively, p < 0.001). Acromegalic patients were also classified according to their status of remission (a total of 27 patients were in remission and 29 patients were not in remission). Both age and gender were similar between the groups (p = 0.145 and p = 0.616, respectively). MPV levels at the time of diagnosis and after six months of treatment (p = 0.555 and p = 0.917, respectively) were not statistically significant. CONCLUSIONS Our results suggest that MPV levels are higher in acromegalic patients than the controls until the early stages of treatment, independent of diabetes. Therefore, MPV levels may be an important determinant of acromegalic patients.


Nigerian Journal of Clinical Practice | 2015

A thyrotropin‑secreting macroadenoma with positive growth hormone and prolactin immunostaining: A case report and literature review

F Kuzu; Taner Bayraktaroglu; F Zor; Bd Gün; Ys Salihoğlu; M Kalaycı

Thyrotropin (thyroid stimulating hormone [TSH]) secreting pituitary adenomas (TSHoma) are rare adenomas presenting with hyperthyroidism due to impaired negative feedback of thyroid hormone on the pituitary and inappropriate TSH secretion. This article presents a case of TSH-secreting macroadenoma without any clinical hyperthyroidism symptoms accompanying immunoreaction with growth hormone (GH) and prolactin. A 36-year-old female patient was admitted with complaints of irregular menses and blurred vision. On physical exam, she had bitemporal hemianopsia defect. Magnetic resonance imaging (MRI) evaluation showed suprasellar macroadenoma measuring 33 mm × 26 mm × 28 mm was detected on pituitary MRI. She had no hyperthyroidism symptoms clinically. Although free T4 and free T3 levels were elevated, TSH level was inappropriately within the upper limit of normal. Response to T3 suppression and thyrotropin releasing hormone-stimulation test was inadequate. Other pituitary hormones were normal. Transsphenoidal adenomectomy was performed due to parasellar compression findings. Immunohistochemically widespread reaction was observed with TSH, GH and prolactin in the adenoma. The patient underwent a second surgical procedure 2 months later due to macroscopic residual tumor, bitemporal hemianopsia and a suprasellar homogenous uptake with regular borders on indium-111 octreotide scintigraphy. After second surgery; due to ongoing symptoms and residual tumor, she was managed with octreotide and cabergoline treatment. On her follow-up with medical treatment, TSH and free T4 values were within normal limits. Although silent TSHomas are rare, they may arise with compression symptoms as in our case. The differential diagnosis of secondary hyperthyroidism should include TSHomas and thyroid hormone receptor resistance syndrome.


Journal of Strength and Conditioning Research | 2011

Gonadal function in male mountain bikers.

Faruk Yamaner; Hulusi Atmaca; Taner Bayraktaroglu; Mustafa Aydin; Selim Aydemir

Yamaner, F, Atmaca, H, Bayraktaroglu, T, Aydin, M, and Aydemir, S. Gonadal function in male mountain bikers. J Strength Cond Res 25(8): 2311-2315, 2011—Some studies reported testicular disorders associated with biking in mountain cyclists, which include injuries, erectile dysfunction, and higher scrotal temperatures. But none of these studies evaluated gonadal function. Therefore, the aim of this study was to evaluate gonadal function in male mountain bikers. Twenty-two male professional mountain bikers and 30 healthy noncyclist controls were included in the study. The mean age and body mass index were similar in both groups. Fasting blood samples for the measurement of the levels of total testosterone (TT), sex-hormone binding globulin (SHBG), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were obtained from all study participants before any physical activity. In addition, because insulin sensitivity and leptin modulate gonadal function, the concentrations of insulin, glucose, and leptin were also measured in the same samples. Calculated free testosterone (cFT) and bioavailable testosterone (bioT) were calculated from SHBG and TT. Basal hormonal levels including insulin, leptin, LH, FSH, SHBG, TT, glucose, and homeostasis model assessment scores were similar between the groups. However, bioT and cFT levels were significantly lower (p ≤ 0.05) in the mountain bikers than those in the controls. Despite the lower mean testosterone levels in the study group, the levels of LH and FSH were similar to controls. Insulin and leptin do not contribute to lower testosterone levels. In conclusion, male mountain bikers have lower testosterone concentrations compared to controls. This alteration cannot solely be explained by testicular dysfunction. The etiology of lower testosterone levels in cyclists appears to be complex and requires further research. The influence of such a decline on the athletes performance, quality of life, and muscle strength is not known as yet.


The Korean Journal of Internal Medicine | 2017

Atrial conduction times and left atrial mechanical functions and their relation with diastolic function in prediabetic patients

N.E. Gudul; Turgut Karabağ; Muhammet Rasit Sayin; Taner Bayraktaroglu; Mustafa Aydin

Background/Aims The aim of this study was to investigate atrial conduction times and left atrial mechanical functions, the noninvasive predictors of atrial fibrillation, in prediabetic patients with impaired fasting glucose (IFG) and impaired glucose tolerance (IGT). Methods Study included 59 patients (23 males, 36 females; mean age 52.5 ± 10.6 years) diagnosed with IFG or IGT by the American Diabetes Association criteria, and 43 healthy adults (22 males, 21 females; mean age 48.5 ± 12.1 years). Conventional and tissue Doppler echocardiography were performed. The electromechanical delay parameters were measured from the onset of the P wave on the surface electrocardiogram to the onset of the atrial systolic wave on tissue Doppler imaging from septum, lateral, and right ventricular annuli. The left atrial volumes were calculated by the disk method. Left atrial mechanical functions were calculated. Results The mitral E/A and E’/A’ ratios measured from the lateral and septal annuli were significantly lower in the prediabetics compared to the controls. The interatrial and left atrial electromechanical delay were significantly longer in prediabetic group compared to the controls. Left atrial active emptying volume (LAAEV) and fraction (LAAEF) were significantly higher in the prediabetics than the controls. LAAEV and LAAEF were significantly correlated with E/A, lateral and septal E’/A’. Conclusions In the prediabetic patients, the atrial conduction times and P wave dispersion on surface electrocardiographic were longer before the development of overt diabetes. In addition, the left atrial mechanical functions were impaired secondary to a deterioration in the diastolic functions in the prediabetic patients.

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Fatih Kuzu

Zonguldak Karaelmas University

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Dilek Arpaci

Yıldırım Beyazıt University

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Murat Can

Zonguldak Karaelmas University

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Muammer Bilici

Zonguldak Karaelmas University

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Sevil Uygun Ilikhan

Zonguldak Karaelmas University

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Hulusi Atmaca

Ondokuz Mayıs University

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Selim Aydemir

Zonguldak Karaelmas University

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Yucel Ustundag

Zonguldak Karaelmas University

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Figen Barut

Zonguldak Karaelmas University

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