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Featured researches published by Cagatay Buyukuysal.


Sleep and Breathing | 2014

Optic disc and retinal nerve fiber layer parameters as indicators of neurodegenerative brain changes in patients with obstructive sleep apnea syndrome

Nergiz Huseyinoglu; Metin Ekinci; Serkan Ozben; Cagatay Buyukuysal; Murat Yıldırım Kale; Hilal Safak Sanivar

PurposeRetina is a unique part of the central nervous system (CNS) for visualizing the processes of axonal and neuronal degeneration. Optical coherence tomography (OCT) allows direct visualization and measurement of retinal nerve fiber layer (RNFL) thickness, macular volume, and optic disc (OD) parameters. One of the disorders associated with atrophy in different brain regions is obstructive sleep apnea syndrome (OSAS). In the present study, we aimed to determine OD and RNFL changes measured by OCT for investigating the progress of neurodegeneration development in OSAS, excluding all the other conditions that can directly affect RNFL thickness and optic nerve parameters.MethodsBoth eyes of 101 patients with OSAS and 20 controls were investigated by OCT. Full-night polysomnography (PSG) and ophthalmologic examination including automated visual field (VF) examination and OCT were performed in all of the patients.ResultsAccording to the OSAS grading, patients were grouped as mild (n = 15), moderate (n = 27), and severe (n = 59). We found significant decrease in RNFL thickness only in the patients with severe OSAS compared with the other groups and decreased macular ganglion cell thickness in the severe OSAS group compared with the control group. VF parameters were significantly worsened in all the OSAS subgroups compared to the control group. We found different data such as normal or increased optic nerve parameters as result of subtle OD edema, which may mask possible peripapillar axonal loss.ConclusionsWe think that evaluation of neurodegeneration in OSAS is not always possible by examining OD and RNFL because there are difficulties due to the confounding issues of cerebral atrophy and OD edema.


BMC Neuroscience | 2014

Ischemia modified albumin increase indicating cardiac damage after experimental subarachnoid hemorrhage

Şerefden Açıkgöz; Nurullah Edebali; Figen Barut; Murat Can; Ishak Ozel Tekin; Cagatay Buyukuysal; Bektas Acikgoz

BackgroundCardiac complications are often developed after subarachnoid hemorrhage (SAH) and may cause sudden death of the patient. There are reports in the literature addressing ischemia modified albumin (IMA) as an early and useful marker in the diagnosis of ischemic heart events. The aim of this study is to evaluate serum IMA by using the albumin cobalt binding (ACB) test in the first, second, and seventh days of experimental SAH in rats.Twenty-eight Wistar albino rats were divided into four groups each consisting of seven animals. These were classified as control group, 1st, 2nd and 7th day SAH groups. SAH was done by transclival basilar artery puncture. Blood samples were collected under anesthesia from the left ventricles of the heart using the cardiac puncture method for IMA measurement. Histopathological examinations were performed on the heart and lung tissues. Albumin with by colorimetric, creatine kinase (CK), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) were determined on an automatic analyser using the enzymatic method. IMA using by ACB test was detected with spectrophotometer.ResultsSerum IMA (p = 0.044) in seventh day of SAH were higher compared to the control group. Total injury scores of heart and lung tissue, also myocytolysis at day 7 were significantly higher than control group (p = 0.001, p = 0.001, p = 0.001), day 1 (p = 0.001, p = 0.001, p = 0.001) and day 2 (p = 0.001, p = 0.007, p = 0.001). A positive correlation between IMA - myocytolysis (r = 0.48, p = 0.008), and between IMA – heart tissue total injury score (r = 0.41, p = 0.029) was found.ConclusionThe results revealed that increased serum IMA may be related to myocardial stress after SAH.


Revista Brasileira De Anestesiologia | 2013

Effects of esmolol, lidocaine and fentanyl on P wave dispersion, QT, QTc intervals and hemodynamic responses to endotracheal intubation during propofol induction: a comparative study

Volkan Hancı; Serhan Yurtlu; Turgut Karabag; Dilek Okyay; Sedat Hakimoğlu; Gülay Erdoğan Kayhan; Cagatay Buyukuysal; Hilal Ayoğlu; Işıl Özkoçak Turan

BACKGROUND AND OBJECTIVES In our study we aimed to investigate the effect of esmolol, lidocaine and fentanyl on P-wave dispersion (Pwd), QT and corrected QT (QTc) durations and hemodynamic responses to endotracheal intubation during propofol induction. METHODS A total of eighty adult patients, American Society of Anesthesiologists (ASA) Physical Status I or II aged 18 to 60 years were included in this prospective, randomised, double-blind study. All patients had control electrocardiograms (ECGs) done before anesthesia induction. The patients were randomised into four equal groups. The control group (Group C) received saline 5mL, the esmolol group (Group E) received esmolol 0.5mg.kg(-1), the fentanyl group (Group F) received fentanyl 2μg.kg(-1) and the lidocaine group (Group L) received lidocaine 1.5mg.kg(-1) before anesthesia induction. Anesthesia was induced with intravenous propofol. ECGs for all patients were performed during the 1(st) and 3(rd) minutes of induction, 3minutes after administration of muscle relaxant, and at 5minutes and 10minutes after intubation. Pwd and QT intervals were measured on all ECGs. QTc intervals were determined using the Bazett formula. Heart rate (HR) and mean arterial pressure (MAP) were recorded before and after induction of anesthesia, immediately after intubation, and 1, 3, 5, 7 and 10minutes after intubation. RESULTS Compared with control, HR significantly increased in Group C, Group L and Group F after intubation. However, in Group E, there was no significant difference in HR values between control and after intubation. Compared with control, MAP significantly increased in Group C and Group L after the intubation. However, in Group E and Group F, there was no significant difference in MAP values between control and after the intubation. Compared with control, Pwd significantly increased in Group C after intubation. In Group L, Group F and Group E, there was no significant difference in Pwd values between control and after the intubation. Compared with control, QTc duration significantly increased in Group C and L after the intubation. In Group F and Group E, there was no significant difference in QTc durations between control and after the intubation. CONCLUSION We concluded that administration of esmolol before intubation prevents tachycardia and an increase in MAP, Pwd and QTc duration caused by laryngoscopy and tracheal intubation.


European Journal of Echocardiography | 2012

Investigation of the atrial electromechanical delay duration in Behcet patients by tissue Doppler echocardiography.

Turgut Karabag; Mustafa Aydin; S.M. Dogan; Rafet Koca; Cagatay Buyukuysal; Muhammet Rasit Sayin; Nesimi Yavuz

AIMS To investigate the atrial electromechanical delay (EMD) duration that is a non-invasive predictor of atrial fibrillation (AF) in patients with Behcets disease (BD). METHODS AND RESULTS Thirty-eight Behcets patients (24 females, 14 males; mean age: 43.6 ± 10.3 years) who were being followed in the dermatology or internal medicine department and 29 demographically matched controls (13 females, 16 males; mean: age 42.6 ± 11.1 years) were included in the study. The inclusion criteria were recurrent oral ulcerations and two of the following features: recurrent genital ulceration, eye lesions, skin lesions or positive pathergy skin test for Behcets group. Using tissue Doppler imaging, atrial electromechanical coupling [time interval from the onset of P wave on surface electrocardiogram to the beginning of A wave interval with tissue Doppler echocardiography (PA)] were measured from the lateral mitral annulus (PA lateral), septal mitral annulus (PA septum), and right ventricular tricuspid annulus (PA tricuspid). The mean disease duration was 10.5 ± 7.7 years. The inter-atrial and intra-atrial EMD were significantly higher in the Behcet group than those in the controls (19.8 ± 8.2 vs. 13.1 ± 4.4 ms, P = 0.001; 11.5 ± 7.4 vs. 6.9 ± 3.7 ms, P = 0.02; respectively). The left atrial EMD was similar in both of the groups. However, the P(max) and PWD values were significantly higher in the BD group compared with those in the controls (120.5 ± 10.1 vs. 112.1 ± 5.9 ms, P < 0.0001; 44.9 ± 10.7 vs. 28.4 ± 5.9 ms, P < 0.0001; respectively). CONCLUSION Atrial electromechanical conduction times were increased in the BD patients compared with those in the controls. The tendency of BD patients to go into AF can be easily and non-invasively detected using tissue Doppler echocardiography. These findings may be indicators for subclinical cardiac involvement.


Kaohsiung Journal of Medical Sciences | 2017

Relationship of mast cell density with lymphangiogenesis and prognostic parameters in breast carcinoma

Sevinç Hallaç Keser; Nilufer Onak Kandemir; Dilek Ece; Gonca Geçmen; Aylin Ege Gül; Nagehan Ozdemir Barisik; Sibel Sensu; Cagatay Buyukuysal; Figen Barut

In many cancers, mast cell density (MCD) in the tumor microenvironment is associated with tumor progression and, to a greater extent, angiogenesis. Our study was designed to investigate the correlation between MCD, tumor lymphangiogenesis, and several well‐established prognostic parameters in breast cancer. One hundred and four cases of invasive breast carcinoma diagnosed in our clinic between 2007 and 2011 were included. Mast cells and lymphatic vessels were stained with toluidine blue and D2‐40, respectively, and their densities were calculated in various areas of tumors and lymph nodes. The variables of MCD and lymphatic vessel density (LVD) were compared using prognostic parameters as well as with each other. As tumor size and volume increased, MCD increased comparably in metastatic lymph nodes; intratumoral and peritumoral LVD also increased. Lymphovascular invasion, lymphatic invasion, perineural invasion, and estrogen receptor positivity were positively related to intratumoral MCD. The relationship between peritumoral MCD and nontumoral breast tissue MCD was statistically significant. Stage was correlated with MCD in metastatic lymph nodes. Metastatic lymph node MCD and intratumoral MCD were also significantly related. Stage, lymphatic invasion, perineural invasion, lymphovascular invasion, and metastatic lymph node MCD were all correlated with intratumoral and/or peritumoral LVD. As nuclear grade increased, intratumoral LVD became higher. In breast carcinoma, MCD, depending on its location, was related to several prognostic parameters. Notably, mast cells may have at least some effect on lymphangiogenesis, which appears to be a predictor of tumor progression.


Neurologia I Neurochirurgia Polska | 2017

Unilaterally posterior lumbar interbody fusion with double expandable peek cages without pedicle screw support for lumbar disc herniation

Aydemir Kale; Ibrahim Ilker Oz; Ayhan Onk; Murat Kalayci; Cagatay Buyukuysal

OBJECTIVES Posterior lumbar interbody fusion (PLIF) is usually bilateral procedure, and it is combined with posterior by bilateral pedicle screw support or with fixation. The purpose of this retrospective study was to compare the surgical outcomes of simple discectomy and PLIF without pedicle screw support in patients with lumbar disc herniation (LDH). PATIENTS AND METHODS 60 patients with single segment LDH were operated between February 2010 and June 2013. 40 patients were treated with simple discectomy (Group 1) and 20 patients were treated with PLIF using double expandable polyetheretherketone (PEEK) cages without instrumentation (Group 2) unilaterally. Pain and function were evaluated by the visual analog scale (VAS) and Oswestry disability index (ODI) before and 18 months after surgery. Besides, PLIF patients were evaluated with computerized tomography (CT) scan of lumbar vertebra for the evaluation of the height of the disc, instability and fusion. RESULTS Both leg and low back pain VAS scores were significantly improved 18 months after surgery in both of the groups (p<0.001). Significant decrease in VAS low back pain scores was seen in group 2 when compared to group 1 (p<0.001). Height of the intervertebral disc space was preserved and no instability was detected in group 2. No recurrence and 80% fusion rate was achieved in group 2. CONCLUSION This study showed that unilateral PLIF intervention with double expandable PEEK cages without pedicle screw support would be sufficient in the management of single segment lumbar disc herniation in patients whom are thought to have lumbar stabilization.


Neuro-Ophthalmology | 2014

Relationship between Structural and Functional Assessment of the Visual System in Mildly Disabled Relapsing-Remitting Multiple Sclerosis Patients

Nergiz Huseyinoglu; Metin Ekinci; Serkan Ozben; Cagatay Buyukuysal

Abstract Studies that explored the anterior visual pathway in the patients with multiple sclerosis (MS) have demonstrated contradictory results about the correlation between structural and functional status of optic nerve and retina. We aimed to investigate the functional and structural findings in our cohort of mildly disabled relapsing-remitting MS patients. A total of 134 eyes (80 eyes of the patients with MS and 54 eyes of the control group) were investigated. Eyes of MS patients were divided into two groups—as eyes with history of optic neuritis (ON group) and without history of optic neuritis (NON group). Ophthalmological investigation including visual evoked potentials, standard automated perimetry, and optical coherence tomography were performed for all participants. Retinal and macular thicknesses were significantly decreased in ON and NON groups compared with controls. Also, visual evoked potential latencies and visual field loss were worse in the both MS groups compared with control group. We did not find any correlation between visual evoked potentials and retinal or macular thickness values but visual field parameters were correlated between retinal and macular layer loss in the NON group. According to our results and some previous studies, although both functional and structural changes were detected in patients with MS, functional status markers do not always show parallelism (or synchrony) with structural changes, especially in eyes with history of optic neuritis.


Journal of Radiation Research | 2018

Neuroprotective effects of Quercetin on radiation-induced brain injury in rats

Aydemir Kale; Özcan Pişkin; Yılmaz Baş; Bengü Gülhan Aydın; Murat Can; Özlem Elmas; Cagatay Buyukuysal

Abstract Extensive research has been focused on radiation-induced brain injury. Animal and human studies have shown that flavonoids have remarkable toxicological profiles. This study aims to investigate the neuroprotective effects of quercetin in an experimental radiation-induced brain injury. A total of 32 adult male Wistar-Albino rats were randomly divided into four groups (control, quercetin, radiation, and radiation+quercetin groups, with eight rats in each group). Doses (50 mg/kg) of quercetin were administered to the animals in the quercetin and radiation+quercetin groups; radiation and radiation+quercetin groups were exposed to a dose of 20 Gy to the cranium region. Tissue samples, and biochemical levels of tissue injury markers in the four groups were compared. In all measured parameters of oxidative stress, administration of quercetin significantly demonstrated favorable effects. Both plasma and tissue levels of malondialdehyde and total antioxidant status significantly changed in favor of antioxidant activity. Histopathological evaluation of the tissues also demonstrated a significant decrease in cellular degeneration and infiltration parameters after quercetin administration. Quercetin demonstrated significant neuroprotection after radiation-induced brain injury. Further studies of neurological outcomes under different experimental settings are required in order to achieve conclusive results.


Revista Brasileira De Anestesiologia | 2013

Efeitos de esmolol, lidocaína e fentanil nos intervalos dispersão da onda P, QT, QTc e respostas hemodinâmicas à intubação endotraqueal durante indução com propofol: um estudo comparativo

Volkan Hancı; Serhan Yurtlu; Turgut Karabag; Dilek Okyay; Gülay Erdoğan Kayhan; Cagatay Buyukuysal; Hilal Ayoğlu; Işıl Özkoçak Turan

JUSTIFICATIVA E OBJETIVOS: Investigar o efeito de esmolol, lidocaina e fentanil na dispersao da onda P (DP), duracoes dos intervalos QT e QT corrigido (QTc) e as respostas hemodinâmicas a intubacao endotraqueal durante a inducao com propofol. METODOS: Foram incluidos 80 pacientes adultos, estado fisico ASA I ou II, idade entre 18 e 60 anos, neste estudo prospectivo, randomico e duplo-cego. Todos os pacientes foram submetidos a exame eletrocardiografico (ECG) antes da inducao da anestesia. Os pacientes foram randomicamente alocados em quatro grupos iguais. O grupo controle (Grupo C) recebeu 5 mL de solucao salina; o grupo esmolol (Grupo E) recebeu 0,5 mg.kg-1 de esmolol; o grupo fentanil (Grupo F) recebeu 2 µg.kg-1 de fentanil e o grupo lidocaina (Grupo L) recebeu 1,5 mg.kg-1 de lidocaina antes da inducao anestesica. A anestesia foi induzida com propofol. ECG foi feito em todos os pacientes durante o primeiro e o terceiro minutos de inducao, 3 minutos apos a administracao de relaxante muscular e 5 e 10 minutos apos intubacao. A DP e intervalos QT foram medidos em todos os ECGs. Os intervalos QTc foram determinados com o uso da formula de Bazett. Frequencia cardiaca (FC) e pressao arterial media (PAM) foram registradas antes e depois da inducao anestesica, imediatamente apos a intubacao e em 1, 3, 5, 7 e 10 minutos apos a intubacao. RESULTADOS: Apos a intubacao, a FC aumentou significativamente nos Grupos C, L e F em comparacao com o grupo controle. Porem, nao houve diferenca significativa nos valores da FC apos a intubacao entre os grupos E e controle. Nos Grupos C e L, a PAM aumentou significativamente apos a intubacao em comparacao com o grupo controle. No entanto, nos Grupos L, F e E nao houve diferenca significativa entre os valores da PAM apos a intubacao em comparacao com o grupo controle. A DP foi significativamente mais longa no Grupo C apos a intubacao em comparacao com o grupo controle. Porem, nos grupos L, F e E nao houve diferenca significativa entre os valores de DP apos a intubacao em comparacao com o grupo controle. A duracao do intervalo QTc foi significativamente maior nos grupos C e L apos a intubacao em comparacao com o grupo controle. Porem, nao houve diferenca significativa na duracao do QTc nos grupos F e E apos a intubacao em comparacao com o grupo controle. CONCLUSAO: Concluimos que a administracao de esmolol antes da intubacao previne a taquicardia, o aumento da PAM e as duracoes da onda P e intervalo QTc causados pela laringoscopia e intubacao traqueal.


Neuro-Ophthalmology | 2013

Optical Coherence Tomography in Patients with Relapsing-Remitting Multiple Sclerosis without Optic Neuritis: A 20-Month Longitudinal Study

Nergiz Huseyinoglu; Serkan Ozben; Metin Ekinci; Cagatay Buyukuysal; Murat Yıldırım; Hilal Safak; Halil Hüseyin

Abstract Optical coherence tomography is supported and used as a technique for visualisation of neuro-axonal loss in multiple sclerosis, but there are also a few studies expressing the opposite view. The aim of our study was to investigate retinal nerve fibre layer and optic nerve head parameters in patients with multiple sclerosis without a history of prior optic neuritis and symptoms of a new clinical attack during the follow-up for a total of 20-month period. Full ophthalmic evaluation was performed for all of the participants. The baseline retinal nerve fibre layer and macular thicknesses and focal and global loss of macular volume values were significantly lower in the eyes of the patients with multiple sclerosis compared with the healthy controls. No significant change between baseline and follow-up scans were found in all optical coherence tomography parameters in the multiple sclerosis group. Statistical analyses revealed significant retinal nerve fibre layer and macular thickness differences between baseline and second measurements in the controls. No significant difference in percent change between baseline and second measurements was observed between the patient and control groups. We conclude that whereas healthy subjects have an age-related tendency toward a decrease in retinal nerve fibre layer thickness, patients with multiple sclerosis patients are likely to pass through different stages of retinal thinning and thickening due to subclinical optic neuritis and, as a result, we could not detect any statistically significant change between baseline and second measurements in our multiple sclerosis patients.

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Dive into the Cagatay Buyukuysal's collaboration.

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Turgut Karabag

Zonguldak Karaelmas University

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Muhammet Rasit Sayin

Zonguldak Karaelmas University

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Mustafa Aydin

Zonguldak Karaelmas University

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S.M. Dogan

Zonguldak Karaelmas University

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Murat Can

Zonguldak Karaelmas University

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Cem Çil

Zonguldak Karaelmas University

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Dilek Okyay

Dokuz Eylül University

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Hilal Ayoğlu

Zonguldak Karaelmas University

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Işıl Özkoçak Turan

Zonguldak Karaelmas University

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