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Featured researches published by Ertugrul Colak.


Mediators of Inflammation | 2008

Serum Amyloid A, Procalcitonin, Tumor Necrosis Factor-α, and Interleukin-1β Levels in Neonatal Late-Onset Sepsis

Birsen Ucar; Bilal Yildiz; M. Arif Aksit; Coskun Yarar; Omer Colak; Yildiz Akbay; Ertugrul Colak

Background. Sepsis is an important cause of mortality in newborns. However, a single reliable marker is not available for the diagnosis of neonatal late-onset sepsis (NLS). The aim of this study is to evaluate the value of serum amyloid A (SAA) and procalcitonin (PCT) in the diagnosis and follow-up of NLS. Methods. 36 septic and healthy newborns were included in the study. However, SAA, PCT, TNF-α, IL-1β, and CRP were serially measured on days 0, 4, and 8 in the patients and once in the controls. Töllners sepsis score (TSS) was calculated for each patient. Results. CRP, PCT, and TNF-α levels in septic neonates at each study day were significantly higher than in the controls (P = .001). SAA and IL-1β levels did not differ from healthy neonates. The sensitivity and specificity were 86.8% and 97.2% for PCT, 83.3% and 80.6% for TNF-α, 75% and 44.4% for SAA on day 0. Conclusion. Present study suggests that CRP seems to be the most helpful indicator and PCT and TNF-α may be useful markers for the early diagnosis of NLS. However, SAA, IL-1β, and TSS are not reliable markers for the diagnosis and follow-up of NLS.


Experimental Neurology | 2016

Gender- and anxiety level-dependent effects of perinatal stress exposure on medial prefrontal cortex

Erdem Söztutar; Ertugrul Colak; Emel Ulupinar

Early life stress leads to psychopathological processes correlated with the predisposition of individuals. Prolonged development of the prefrontal cortex (PFC), playing a critical role in the cognition, personality and social behavior, makes it susceptible to adverse conditions. In this study, we evaluated the dendritic morphology of medial PFC neurons in rats subjected to perinatal stress exposure. Unbiased stereological counting methods showed that total number estimation of c-Fos (+) nuclei, indicating the neuronal activation upon stressful challenge, significantly increased in high anxious animals compared with low anxious and control groups, in both gender. Golgi-Cox staining of neurons displayed anxiety level- and sex-dependent reduction in the dendritic complexity and spine density of pyramidal neurons, especially in the stressed males. While the total length of dendrites were not correlational; density of spines, specifically the mushroom subtypes, showed a negative correlation with the anxiety level of stressed animals. These results suggest that medial PFC is a critical site of neural plasticity within the stressor controllability paradigm. Outcomes of early life stress might be predicted by analyzing the density and morphology of spines in the apical dendrites of pyramidal neurons in correlation with the anxiety-like behavior of animals.


Archives of Gynecology and Obstetrics | 2011

Differential expression of P16 and P21 in benign and malignant uterine smooth muscle tumors

Nurcan Uluskan Ünver; Mustafa Fuat Acikalin; Ülkü Öner; Evrim Ciftci; Sinan Özalp; Ertugrul Colak

PurposeThe diagnosis of benign and malignant uterine smooth muscle tumors depends on morphologic criteria such as nuclear atypia, coagulative tumor cell necrosis and mitotic activity. Most of these tumors are readily classifiable into benign or malignant categories using these criteria. However, the distinction between leiomyomas and leiomyosarcomas may at times be problematic. Hence, it would be useful to have additional markers which could help to distinguish these tumors. The aim of the study was to evaluate p16 and p21 expressions in uterine smooth muscle tumors and determine whether p16 and p21 have a potential value in the differential diagnosis of problematic cases. In addition, we evaluated whether the differential expression of p16 and p21 in uterine leiomyosarcomas correlated with tumor recurrence and patient survival.Methodsp16 and p21 expressions were investigated by immunohistochemistry from paraffin-embedded tissues in 53 cases of uterine smooth muscle tumors consisting of 15 cases of leiomyoma, 14 cases of atypical leiomyoma (leiomyoma with bizarre nuclei), 3 cases of smooth muscle tumor of uncertain malignant potential (STUMP) and 21 cases of leiomyosarcoma. Cases were evaluated with respect to both staining percentage and intensity.ResultsThere was a statistically significant difference in p16 and p21 staining percentage and intensity between leiomyosarcomas and the other groups. There was no difference in p16 and p21 expressions between leiomyomas, atypical leiomyomas (leiomyoma with bizarre nuclei) and STUMPs. Multivariate analysis showed that the tumor stage was the only independent significant prognostic factor for overall survival in leiomyosarcomas. Neither p16 nor p21 was correlated with disease-free or overall survival.ConclusionsOur findings suggested that p16 and p21 may be of value as an adjunct to conventional morphologic criteria in the assessment of problematic uterine smooth muscle tumors.


The Scientific World Journal | 2015

Predictors of a Good Outcome after Endovascular Stroke Treatment with Stent Retrievers

Ozcan Ozdemir; Semih Giray; Zülfikar Arlier; Demet Funda Baş; Yusuf İnanç; Ertugrul Colak

Background and Purpose. Successful recanalization after endovascular stroke therapy (EVT) did not translate into a good clinical outcome in randomized trials. The goal of the study was to identify the predictors of a good outcome after mechanical thrombectomy with stent retrievers. Methods. A retrospective analysis of a prospectively collected database included consecutive patients treated with stent retrievers. We evaluated the influence of risk factors for stroke, baseline NIHSS score, Alberta Stroke Program Early CT (ASPECT) score, recanalization rate, onset-to-recanalization and onset-to-groin puncture time, and glucose levels at admission on good outcomes. The number of stent passes during procedure and symptomatic hemorrhage rate were also recorded. A modified Rankin Scale (mRS) score of 0–2 at 90 days was considered as a good outcome. Results. From January 2011 to 2014, 70 consecutive patients with an acute ischemic stroke underwent EVT with stent retrievers. The absence of a medical history of diabetes was associated with good outcomes. Apart from diabetes, the baseline demographic and clinical characteristics of patients were similar between subjects with poor outcome versus those with good outcomes. Median time from onset to recanalization was significantly shorter in patients with good outcomes 245 (IQR: 216–313 min) compared with poor outcome patients (315 (IQR: 240–360 min); P = 0.023). Symptomatic intracranial hemorrhage was observed in eight (21.6%) of 37 patients with poor outcomes and no symptomatic hemorrhage was seen in patients with good outcomes (P = 0.006). In multivariate stepwise logistic regression analysis, a favorable ASPECT score (ASPECT > 7) and successful recanalization after EVT were predictors of good outcomes. Every 10-year increase was associated with a 3.60-fold decrease in the probability of a good outcome at 3 months. The probability of a good outcome decreases by 1.43-fold for each 20 mg/dL increase in the blood glucose at admission. Conclusion. To achieve a good outcome after EVT with stent retrievers, quick and complete recanalization and better strategies for patient selection are warranted. We need randomized trials to identify the significance of tight blood glucose control in clinical outcome during or after EVT.


Career Development International | 2012

Organizational and occupational identification: Relations to teacher satisfaction and intention to early retirement

Murat Gumus; Bahattin Hamarat; Ertugrul Colak; Erol Duran

Purpose – This paper aims to explore the effects of two work related identification (occupational and organizational) of school teachers on intention to early retirement (withdrawal) and satisfaction with the occupation and satisfaction with the school. It also seeks the influence of perceived external prestige on withdrawal and satisfaction.Design/methodology/approach – An empirical study was carried out at public schools in Canakkale, Turkey. Data collected from 238 teachers were analyzed. The correlations between identification and organizational prestige, desire for early retirement, and overall satisfaction of teachers were tested with several demographic variables such as age, gender, tenure and union membership. Ordinal logistic regression analysis (OLR) was conducted to reveal probabilistic behavior of response variables on the basis of explanatory variables.Findings – The results show that both categories of identification have reverse effect on intention to early retirement, and both categories ...


Optometry and Vision Science | 2011

Lenstar versus ultrasound for ocular biometry in a pediatric population.

Huseyin Gursoy; Afsun Sahin; Hikmet Basmak; Ahmet Özer; Nilgun Yildirim; Ertugrul Colak

Purpose. To compare the central corneal thickness (CCT), axial length (AL), anterior chamber depth (ACD), and lens thickness (LT) measured with Lenstar with those obtained with ultrasound pachymetry and A-scan contact ultrasound (ASU) in children. Methods. ODs of 565 school children were included. All measurements were obtained 30 min after instilling 1% tropicamide. For each instrument, three consecutive measurements per each child were performed. Initially, examiner 1 performed measurements with Lenstar to obtain CCT, AL, ACD, and LT. Later, examiner 2 performed measurements with corneal pachymetry to obtain CCT. Finally, ASU was used by examiner 2 to obtain AL, ACD, and LT. Four parameters obtained with Lenstar were compared with those obtained with pachymetry and ASU using Pearson correlation coefficients (r) and Bland-Altman analyses. Result. Lenstar measurements were obtained in 557 of 565 subjects(mean age; 10.48 ± 2.11 years, mean spherical equivalent of the ODs; +0.47 ± 1.18 diopters) whereas ASU and pachymetry could be performed in 530 of 565. Four hundred seventy-nine subjects were statistically assessed after 41 subjects were extracted as outliers from 530 subjects in whom all instruments could be performed. Mean difference between pachymetry and Lenstar was 13.20 ± 13.13 &mgr;m [95% confidence interval (CI): 12.01 to 14.37]. Mean difference between ASU and Lenstar was −0.72 ± 0.35 mm (95% CI: −0.75 to −0.69) for AL, −0.27 ± 0.32 mm (95% CI: −0.30 to −0.24) for ACD, and 0.24 ± 0.28 mm (95% CI: 0.22 to 0.27) for LT. R values were 0.912 (p < 0.001), 0.904 (p < 0.001), 0.487 (p < 0.001), 0.369 (p < 0.001) for CCT, AL, ACD, and LT respectively. Conclusions. AL and ACD were found to be greater with Lenstar, whereas CCT and LT measures were smaller. It is concluded that there was agreement between instruments for CCT and ACD, because the small differences between measures were clinically insignificant. AL and LT values cannot be used interchangeably. If these differences are considered, Lenstar can replace ASU and pachymetry for the majority of children.


European Archives of Oto-rhino-laryngology | 2004

Prognostic significance of Ki-67 expression for patients with laryngeal squamous cell carcinoma primarily treated by total laryngectomy

Mustafa Fuat Acikalin; Ülkü Öner; Nilüfer Tel; Özgül Paşaoğlu; Hamdi Cakli; Ertugrul Colak

The aim of this study was to determine the prognostic value of Ki-67 immunostaining in laryngeal squamous cell carcinomas. Ki-67 labeling was quantified in 63 laryngeal squamous cell carcinomas by counting at least 1,000 tumor cells in the most immunoreactive area in each sample, and the Ki-67 labeling index was calculated as a percentage. The antigen expression was compared with clinical factors, histopathological grading and prognosis. The Ki-67 mean proliferation index for all patients was 25.44% ( range, 2–75%). A significant correlation was found between Ki-67 mean proliferation index and patient age (P<0.05), T-stage (P<0.05), nodal metastasis (P=0.001) and recurrence (P<0.001). There was no significant association between the Ki-67 mean proliferation index and tumor site or histologic grade. A univariate analysis showed that the Ki-67 labeling index >21% (P<0.001), T-stage (P<0.001) and nodal metastasis (P=0.001) are determinants of recurrence. In the multivariate analysis, the Ki-67 labeling index >21% (P<0.001), T-stage (P<0.001) and nodal metastasis (P<0.05) were independent predictors of recurrence. Kaplan-Meier plots of survival in patients with Ki-67 values above and below the median (21%) of the general study population showed that a high Ki-67 labeling index correlated with a shorter disease-free survival (P<0.0001). The analysis of the Ki-67 labeling index at the time of initial surgery may be a powerful prognostic marker for patients with laryngeal squamous cell carcinoma and may be useful for selecting subgroups of patients who should be treated with more aggressive therapies.


Journal of Aapos | 2012

Long-term follow-up of bilateral botulinum toxin injections versus bilateral recessions of the medial rectus muscles for treatment of infantile esotropia

Huseyin Gursoy; Hikmet Basmak; Afsun Sahin; Nilgun Yildirim; Yasemin Aydin; Ertugrul Colak

PURPOSE To compare long-term outcomes of botulinum toxin A injection with incisional surgery for the management of infantile esotropia. SUBJECTS AND METHODS Medical records of infants <24 months treated for esotropia with either botulinum toxin injection (botulinum group) or bilateral medial rectus muscle recessions (surgery group) were reviewed. Minimum follow-up was 48 months, and patients with accommodative esotropia or inferior oblique muscle overaction were excluded. Success was defined as alignment with 10(Δ) of orthophoria without surgery (botulinum group) or without reoperation (surgery group) and compared by the use of an adjusted odds ratio (aOR). RESULTS The record review identified a total of 51 patients, with 25 in the botulinum group and 26 in the surgery group. Median pretreatment deviation was similar in the botulinum and surgery groups (40(Δ) vs 45(Δ); P = 0.37), but median age at treatment was earlier in the botulinum group (10 vs 12.5 months; P = 0.01). The mean number of injections in successfully treated botulinum group patients was 1.4. The success rate was similar in the botulinum (68%) and surgery (77%) groups (aOR = 0.87, P = 0.87). The median follow-up time was longer in the botulinum group (84 vs 75 months; P = 0.02). Gross stereopsis was demonstrable in 10 of 15 patients in the botulinum group and 9 of 13 in the surgery group (aOR = 3.6, P = 0.46). CONCLUSIONS There was no difference in binocular alignment with botulinum toxin versus surgical treatment. Botulinum toxin injection may be considered a primary treatment for infantile esotropia.


Ophthalmic Epidemiology | 2013

Vision Screening in Children Entering School: Eskisehir, Turkey

Huseyin Gursoy; Hikmet Basmak; Yetkin Yaz; Ertugrul Colak

Abstract Purpose: To report vision screening results among school children in Eskisehir, Turkey. Methods: Vision screening was performed in 7- to 8-year-old school children in November and December 2011. Best-corrected visual acuity (BCVA) assessment, cover test, and autorefractometer measurement under cycloplegia were performed. Spherical equivalent ≤−0.50 diopters (D) was considered to be myopic, while spherical equivalent >0.75 D was considered to be hypermetropic. Astigmatism was defined as a cylinder power ≥0.75 D. Regression analysis was used to determine the likelihood of having BCVA ≤0.8 Snellen (versus having BCVA >0.8 Snellen) in the presence of independent variables. Results: A total of 709 children were included. The prevalence rates of myopia, hypermetropia, and astigmatism were 22.6%, 10.6%, and 11.0%, respectively. Overall, 145 children (20.4%) needed spectacles, but only 65 of these were wearing them. The prevalence of children who required spectacles for myopia ≤−3.00 D and spectacles for hypermetropia ≥3.00 D were 0.8% and 1.0%, respectively. The prevalence of BCVA ≤ 0.8 Snellen was 56/709 (7.9%). In 39/709 (5.5%) of children, amblyopia was present; strabismus (14/56), isometropia (14/56), and anisometropia (11/56) were the etiologies. Strabismus was diagnosed in 18 children (2.5%). Anisometropia, strabismus, hypermetropia, and astigmatism were associated with BCVA ≤ 0.8 Snellen (odds ratio, OR, 6.32, 39.18, 5.47, 5.17, respectively; p = 0.0001 for all ORs). Conclusions: Myopia and amblyopia rates in Eskisehir were high among school children. The need for a national large-scale vision screening program for children that includes diverse regions of Turkey is apparent.


Computational and Mathematical Methods in Medicine | 2012

Comparison of Semiparametric, Parametric, and Nonparametric ROC Analysis for Continuous Diagnostic Tests Using a Simulation Study and Acute Coronary Syndrome Data

Ertugrul Colak; Fezan Mutlu; Cengiz Bal; Setenay Oner; Kazim Ozdamar; Bülent Gök; Yuksel Cavusoglu

We aimed to compare the performance of three different individual ROC methods (one from each of the broad categories of parametric, nonparametric and semiparametric analysis) for assessing continuous diagnostic tests: the binormal method as a parametric method, an empirical approach as a nonparametric method, and a semiparametric method using generalized linear models (GLM). We performed a simulation study with various sample sizes under normal, skewed, and monotone distributions. In the simulations, we used estimates of the ROC curve parameters a and b, estimates of the area under the curve (AUC), the standard errors and root mean square errors (RMSEs) of these estimates, and the 95% AUC confidence intervals for comparison. The three methodologies were also applied to an acute coronary syndrome dataset in which serum myoglobin levels were used as a biomarker for detecting acute coronary syndrome. The simulation and application studies suggest that the semiparametric ROC analysis using GLM is a reliable method when the distributions of the diagnostic test results are skewed and that it provides a smooth ROC curve for obtaining a unique cutoff value. A sample size of 50 is sufficient for applying the semiparametric ROC method.

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Huseyin Gursoy

Eskişehir Osmangazi University

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Hasan Veysi Gunes

Eskişehir Osmangazi University

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Irfan Degirmenci

Eskişehir Osmangazi University

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Hikmet Basmak

Eskişehir Osmangazi University

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Hulyam Kurt

Eskişehir Osmangazi University

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Didem Turgut Coşan

Eskişehir Osmangazi University

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Nilgun Yildirim

Eskişehir Osmangazi University

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Mustafa Fuat Acikalin

Eskişehir Osmangazi University

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Afsun Sahin

Eskişehir Osmangazi University

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Faruk Saydam

Recep Tayyip Erdoğan University

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