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KARAMAN, ÖZCAN

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ÖZCAN
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KARAMAN
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Now showing 1 - 6 of 6
  • PublicationMetadata only
    Does DRD2 polymorphism influence the clinical characteristics of prolactinoma?
    (2015-10-01) Ilhan, MAHMUT MUZAFFER; Kahraman, Ozlem Timirci; Turan, Saime; Turgut, SEDA; Karaman, Ozcan; Zeybek, Umit; SHUKUROV, Samir; Yaylim, Ilhan; Tasan, ERTUĞRUL; İLHAN, MAHMUT MUZAFFER; TURGUT, SEDA; KARAMAN, ÖZCAN; TAŞAN, ERTUĞRUL
    Objectives. - Genetic alterations explaining the clinical variability of prolactinomas still could not be clarified and dopamine D2 receptor (DRD2) polymorphism is a putative candidate for the variable response to dopaminergic treatment. The present study was conducted to investigate the influence of DRD2 TaqI A polymorphism on initial and follow-up characteristics of prolactinoma. Patients and methods. - Seventy-two patients with prolactinoma and 98 age and gender matched control subjects were recruited to the case-control study. Serum prolactin levels were assessed by enzyme-linked immunosorbent assay and DRD2 polymorphism was determined by polymerase chain reaction and restriction length polymorphism analysis. Results. - Decrease of prolactin levels and the tumor shrinkage after cabergoline treatment were 93.9 +/- 5.9% and 58.3 +/- 33.1% in microadenomas and 96.1 +/- 6.1% and 51.7 +/- 29.3 in macroadenomas (P = 0.02 and P > 0.05, respectively). We observed no significant difference for DRD2 genotypes and the alleles between the patients and healthy group (P > 0.05). Prolactin levels before treatment were correlated with tumor diameter before and after treatment and the percentage of prolactin decrease with treatment (P 0.05). Conclusion. - This study revealed that DRD2 TaqI A receptor polymorphism was not associated with the development of prolactinoma and its clinical characteristics. Future studies are needed to clarify the clinical implications of genetic alterations in prolactinoma. (C) 2015 Elsevier Masson SAS. All rights reserved.
  • PublicationOpen Access
    Investigation of the Vitamin D Receptor Polymorphisms in Acromegaly Patients
    (2015-01-01) Ilhan, MAHMUT MUZAFFER; TOPTAS-HEKIMOGLU, Bahar; YAYLIM, Ilhan; Turgut, SEDA; TURAN, Saime; Karaman, Ozcan; Tasan, ERTUĞRUL; İLHAN, MAHMUT MUZAFFER; TURGUT, SEDA; KARAMAN, ÖZCAN; TAŞAN, ERTUĞRUL
    Objective. The genetic structural alterations in the majority of somatotroph adenomas are not clarified and the search for novel candidate genes is still a challenge.We aimed to investigate possible associations between vitamin D receptor (VDR) polymorphisms and acromegaly. Design, Patients, and Methods. 52 acromegaly patients (mean age 45.7 ± 1.9 years) and 83 controls (mean age 43.1 ± 2.6 years) were recruited to the study. VDR polymorphism was determined by polymerase chain reaction-based restriction fragment length polymorphism methods. Results. The distribution of VDR genotypes showed a significant difference in the frequencies of VDR FokI genotypes between patients and controls (𝑃 = 0.034). VDR FokI ff genotype was significantly decreased in acromegaly patients (𝑃 = 0.035) and carriers of FokI Ff genotype had a 1.5-fold increased risk for acromegaly (OR: 1.5, 95% CI: 1.07–2.1; 𝑃 = 0.020). IGF1 levels after treatment were significantly higher in patients carrying the Ff genotype compared to carrying ff genotype (𝑃 = 0.0049). 25(OH)D3 levels were significantly lower in acromegaly patients (𝑃 < 0.001). Conclusions. Our study suggests that VDR FokI genotypes might affect the development of acromegaly and VDR polymorphisms may play a role in the course of acromegaly as a consequence of altering hormonal status.
  • PublicationMetadata only
    Cushing-s syndrome in obese patients with type 2 diabetes: A single center screening study
    (2017-03-01) Karaman, Ozcan; ZUHUR, Sayid Shafi; CIL, Esra; OZDERYA, Aysenur; OZTURK, Feyza Yener; Ilhan, Muzaffer; ALTUNTAS, Yuksel; KARAMAN, ÖZCAN; İLHAN, MAHMUT MUZAFFER
    The frequency of Cushing-s syndrome (CS) in obese patients was not properly determined and the studies focused on the frequency of occult CS and the possible improvement of diabetes and obesity with treatment of CS are needed. In this study, we aimed to investigate the frequency of CS in obese patients with type 2 diabetes. The study enrolled with 200 obese (body mass index (BMI) > 30 kg/m(2)), type 2 diabetes patients between 2009 and 2011 in Sisli Etfal Training and Research Hospital, Turkey. Twenty-eight males and 172 females were recruited to the study. Mean age of the study group was 51.7 +/- 8.5. Nineteen patients (9.5 %) failed to suppress cortisol levels less than 1.8 mu g/dL after a 1-mg overnight dexamethasone suppression test (ODST) and these patients proceeded to have a 2-day 2-mg low-dose dexamethasone suppression test. After further screening, three (%1.5) patients were diagnosed with CS in our study. Among the three patients diagnosed with CS, the tumor was located in the pituitary gland in two patients. The present study revealed that the frequency of Cushing-s syndrome in obese and diabetic patients were 1.5 %, which was much higher than the general population. Occult CS should take into account as an exacerbating factor for diabetes and screening for CS should be considered in poorly controlled diabetic patients.
  • PublicationOpen Access
    The Role of p16 and MDM2 Gene Polymorphisms in Prolactinoma: MDM2 Gene Polymorphisms May Be Associated with Tumor Shrinkage
    (2017-05-01) Turgut, SEDA; Ilhan, Muzaffer; Turan, Saime; Karaman, Ozcan; Yaylim, Ilhan; Kucukhuseyin, Ozlem; Tasan, ERTUĞRUL; TURGUT, SEDA; İLHAN, MAHMUT MUZAFFER; KARAMAN, ÖZCAN; TAŞAN, ERTUĞRUL
    Aim: Prolactinomas are thought to arise from clonal expansion of a single mutated cell which is subjected to growth stimuli of several permissive factors, although the pathogenetic mechanisms underlying tumorigenesis remain unclear. The present study aimed to investigate the role of p16 (540C→G and 580C→T) and mouse double minute 2 (MDM2) (SNP309T→G) gene polymorphisms in tumorigenesis and characteristics of prolactinoma. Patients and methods: A total of 74 patients with prolactinoma and 100 age- and gender-matched healthy individuals were enrolled in the study. Serum prolactin levels were measured by enzyme-linked immunosorbent assay (ELISA). p16 and MDM2 polymorphisms were determined by polymerase chain reaction-restriction fragment polymorphism and agarose gel electrophoresis. Results: p16 540C→G genotype distribution was found to be: CC: 66.2%, CG: 28.4%, GG: 5.4%; p16 580C→T genotype distribution was found to be: CC: 82.4%, CT: 17.6%, TT: 0% and MDM2 genotype distribution was found to be: TT: 31.1%, TG: 47.3%, GG: 21.6% in patients with prolactinoma. Tumor diameter before treatment was correlated with prolactin levels before treatment and percentage of prolactin decrease with treatment (r=0.719, p<0.001, p=0.034 r=0.256, respectively). The number of patients with tumor size decrease of more than 50% in those with homozygous genotype (TT+GG) of MDM2 SNP309T→G was significantly higher than in heterozygous genotype (TG) carriers (odds ratio(OR)=0.18, 95% confidence interval(CI)=0.06-0.58; p=0.003). Conclusion: This study showed that p16 and MDM2 polymorphisms do not play a decisive role in tumorigenesis, but some genotypes of these polymorphisms might be associated with follow-up characteristics of prolactinoma.
  • PublicationMetadata only
    Esophagus motility in overt hypothyroidism
    (2014-07-01) Ilhan, MAHMUT MUZAFFER; Arabaci, ELİF; Turgut, SEDA; Karaman, Ozcan; DANALIOGLU, Ahmet; Tasan, ERTUĞRUL; İLHAN, MAHMUT MUZAFFER; ARABACI, ELİF; TURGUT, SEDA; KARAMAN, ÖZCAN; TAŞAN, ERTUĞRUL
    Purpose Gastrointestinal tract is one of the most affected systems in hypothyroidism. Despite decreased esophageal emptying, prolonged esophageal and gastric transit time have been indicated in previous reports, the mechanism of thyroid hormones activity and antibodies on the esophagus motility is not yet fully understood. This study was conducted to evaluate the esophagus motility by manometry in hypothyroid patients.
  • PublicationOpen Access
    Acromegaly can be associated with impairment of LES relaxation in the oesophagus
    (2015-09-01) Ilhan, MAHMUT MUZAFFER; DANALIOGLU, Ahmet; Turgut, SEDA; Karaman, Ozcan; Arabaci, ELİF; Tasan, ERTUĞRUL; İLHAN, MAHMUT MUZAFFER; TURGUT, SEDA; KARAMAN, ÖZCAN; ARABACI, ELİF; TAŞAN, ERTUĞRUL
    Introduction: Although prolonged small intestine and colonic transit time has been demonstrated in acromegaly patients, the influence of acromegaly on oesophagus motility and the pathological mechanisms involved are still not clarified. We aimed to investigate manometric measurements to ascertain whether oesophagus motility is affected in active acromegaly patients. Material and methods: The study was performed in an institutional referral centre at a tertiary care hospital. Twenty-three acromegaly patients (mean age 43.2 ± 13.2 years) and 25 sex- and age-matched healthy control subjects (mean age 48.6 ± 7.9 years) were recruited to a case-control study. Oesophageal manometry was performed using MMS (Medical Measurement Systems, Netherlands) Solar GI — Air Charged Intelligent Gastrointestinal Conventional Manometry. Results: In manometric measurements the lower oesophageal sphincter pressure was 18 ± 7 mmHg in acromegaly patients and 15.6 ± 4.4 mm Hg in controls, and there was no significant difference (p = 0.17). The percentage of relaxation was 64.8% and 81.8%, respectively, and it was significantly lower in acromegaly patients than in controls (p < 0.001). Additionally, the duration of relaxation was found to be 4 ± 1.9 seconds and 5 ± 1.7 seconds in patients and controls, respectively (p = 0.049). Conclusions: Our study has demonstrated a significant reduction in the percentage and duration of lower oesophageal sphincter relaxation in oesophagus motility even in acromegaly patients without any gastrointestinal symptoms. Further clinical and pathophysiological studies are required to clarify the underlying mechanisms of gastrointestinal motility disorders in acromegaly