99 results on '"Ozyürek A"'
Search Results
2. Joubert syndrome: a model for untangling recessive disorders with extreme genetic heterogeneity
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Bachmann-Gagescu, R, Dempsey, J C, Phelps, I G, OʼRoak, B J, Knutzen, D M, Rue, T C, Ishak, G E, Isabella, C R, Gorden, N, Adkins, J, Boyle, E A, de Lacy, N, OʼDay, D, Alswaid, A, Ramadevi A, Radha, Lingappa, L, Lourenço, C, Martorell, L, Garcia-Cazorla, À, Ozyürek, H, Haliloğlu, G, Tuysuz, B, Topçu, M, Chance, P, Parisi, M A, Glass, I A, Shendure, J, and Doherty, D
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- 2015
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3. Molecular docking and inhibition profiles of some antibiotics on lactoperoxidase enzyme purified from bovine milk
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Kalin, Ramazan, primary, Köksal, Zeynep, additional, Bayrak, Songül, additional, Gerni, Serpil, additional, Ozyürek, Işıl Nihan, additional, Usanmaz, Hande, additional, Karaman, Muhammet, additional, Atasever, Ali, additional, Özdemir, Hasan, additional, and Gülçin, İlhami, additional
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- 2020
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4. The Inhibition Effects of D-Penicillamine, D-Penicillamine disulfide and N-Acetyl-D-Penicillamine on Lactoperoxidase Enzyme Activity
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Hasan Özdemir, Ramazan Kalin, and Işıl Nihan Ozyürek
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chemistry.chemical_classification ,Saliva ,Engineering, Chemical ,biology ,Lactoperoxidase ,Molecular biology ,Mühendislik, Kimya ,Sepharose ,Non-competitive inhibition ,Enzyme ,chemistry ,Affinity chromatography ,Laktoperoksidaz,penisilamin,saflaştırma,inhibisyon ,biology.protein ,Thiol ,Peroxidase - Abstract
Meme, tükürük ve diğer mukoza bezlerinden salgılanan laktoperoksidaz (LPO, E.C.1.11.1.7); antibakteriyel özelliğe sahip bir peroksidaz enzimidir. D-Penisilamin; Wilson hastalığı gibi birçok hastalığın tedavisinde kullanılan tiyol yan zincirine sahip bir amino asittir. Bu çalışmanın amacı, sığır laktoperoksidaz enzimine karşı D-Penisilamin, D-Penisilamin disülfit ve N-Asetil-D-penisilamin'in in vitro inhibisyon profillerini belirlemektir. LPO enzimi, % 62,25 verimle 357,92 kat afinite kromatografisi (Sepharose 4B-L-tirozin-sülfanamid) kullanılarak sığır sütünden saflaştırıldı. LPO; D-Penisilamin, D-Penisilamin disülfit ve N-Asetil-D-penisilamin tarafından etkili bir şekilde inhibe edildi. Bu moleküllerin IC50 değerleri sırasıyla 0,584, 0,207 ve 0,552 μM olarak bulundu. D-Penisilamin ve D-Penisilamin disülfit için yarışmalı inhibisyon gösterirken, N-Asetil-D-penisilamin için yarışmasız inhibisyon gösterdi., The lactoperoxidase (LPO, E.C.1.11.1.7) secreted from the breast, saliva and other mucous glands is a peroxidase enzyme with antibacterial properties. D-penicillamine is an amino acid with a thiol side chain, used in the treatment of many diseases such as Wilson disease. The aim of this study was to determine in vitro inhibition profiles of D-Penicillamine, D-Penicillamine disulfide and N-Acetyl-D-penicillamine against bovine lactoperoxidase enzyme. LPO enzyme was isolated from bovine milk using affinity chromatography (Sepharose 4B-L-tyrosine-sulphanamide) 357.92 fold with a yield of 62.25%. LPO was effectively inhibited by D-Penicillamine, N-Acetyl-D-penicillamine and D-Penicillamine disülfit. IC50 values of these molecules were found as 0.584, 0.207 and 0.552 𝜇M, respectively. D-Penicillamine, and D-Penicillamine disülfit exhibited competitive inhibition, and N-Acetyl-D-penicillamine showed noncompetitive inhibition.
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- 2020
5. Evaluation of aortic stiffness in tobacco-smoking adolescents
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Levent, Ertürk, Ozyürek, Arif Ruhi, and Ülger, Zülal
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- 2004
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6. Molecular docking and inhibition profiles of some antibiotics on lactoperoxidase enzyme purified from bovine milk.
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Kalin, Ramazan, Köksal, Zeynep, Bayrak, Songül, Gerni, Serpil, Ozyürek, Işıl Nihan, Usanmaz, Hande, Karaman, Muhammet, Atasever, Ali, Özdemir, Hasan, and Gülçin, İlhami
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- 2022
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7. TPOG-NBL 2009 Protokolü, Yüksek Risk Grubu Otolog Kök Hücre Transplantasyonu Kolu güncel sonuçları
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ÜNAL, EKREM, ÇEÇEN, REFİK EMRE, OLGUN, HATİCE NUR, İNCE, DİLEK, OCAK, SÜHEYLA, Öniz, Haldun, ÖZDEMİR, GÜL NİHAL, HEKİMCİ ÖZDEMİR, HAMİYET, KÖKSAL, YAVUZ, Akıcı, Ferhan, KEBUDİ, REJİN, ÇORAPCIOĞLU, FUNDA VESİLE, TOKUÇ, AYŞE GÜLNUR, Oğuz, Aynur, HAZAR, VOLKAN, Ozyürek, derya, DAĞDEMİR, AYHAN, VARAN, ALİ, DEMİRAĞ, Bengü, GÜLER, ELİF, Emir, suna, and AKSOYLAR, SERAP
- Published
- 2018
8. Prevalence and Types of Main and Right Portal Vein Branching Variations on MDCT
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Çetin Atasoy and Elif Ozyürek
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Adult ,Male ,medicine.medical_specialty ,Adolescent ,Gauche effect ,Abdominal ct ,Portal vein ,Congenital Abnormalities ,Branching (linguistics) ,Right portal vein ,Prevalence ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Child ,Aged ,Aged, 80 and over ,Portal Vein ,business.industry ,Incidence ,General Medicine ,Middle Aged ,Trunk ,medicine.anatomical_structure ,cardiovascular system ,Right posterior ,Abdomen ,Female ,Radiology ,Tomography, X-Ray Computed ,Nuclear medicine ,business - Abstract
Our objective was to investigate the prevalence of variant main and right portal vein ramification in a large group of patients.The study group consisted of 200 patients who underwent consecutive contrast-enhanced abdominal CT examinations performed with an 8-MDCT scanner. Two observers evaluated both thin axial sections and 3D maximum-intensity-projection and volume-rendered images for branching patterns of the main and right portal veins.Conventional main portal vein anatomy was present in 64.5% of the patients. In 9.5% of the patients, the main portal vein trifurcated into the left portal and right anterior and posterior portal veins. In 23.5% of the patients, the main portal vein divided into a common left portal vein-right anterior portal vein trunk and the right posterior portal vein. Three patients (1.5%) had miscellaneous variations. Twenty-two (16.8%) of 131 patients with conventional main portal vein branching had variant right portal vein branching, most of which was a trifurcation, followed by an abnormally proximal origin of the segment VII vein from the right portal vein.Variant main portal vein branching seems to be very frequent. Common right anterior portal vein-left portal vein trunk is far more common than trifurcation. Although less frequent, variations also occur in right portal vein branching.
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- 2006
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9. Learning to use demonstratives in conversation. What do language specific strategies in Turkish reveal?
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Aylin C, Küntay, Asli, Ozyürek, and Max, Planck
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Demonstrative ,Adult ,Male ,Linguistics and Language ,Turkish ,media_common.quotation_subject ,Experimental and Cognitive Psychology ,Referent ,Verbal learning ,Language Development ,Language and Linguistics ,Psycholinguistics ,niet-RU-publicaties ,Kinesics ,Task Performance and Analysis ,Developmental and Educational Psychology ,Humans ,Conversation ,Attention ,Child ,General Psychology ,media_common ,Analysis of Variance ,Age Factors ,Verbal Learning ,language.human_language ,Linguistics ,Focus (linguistics) ,Linguistic competence ,Child, Preschool ,language ,Female ,Cues ,Psychology ,Photic Stimulation - Abstract
Pragmatic development requires the ability to use linguistic forms, along with non-verbal cues, to focus an interlocutor's attention on a referent during conversation. We investigate the development of this ability by examining how the use of demonstratives is learned in Turkish, where a three-way demonstrative system (bu, şu, o) obligatorily encodes both distance contrasts (i.e. proximal and distal) and absence or presence of the addressee's visual attention on the referent. A comparison of the demonstrative use by Turkish children (6 four- and 6 six-year-olds) and 6 adults during conversation shows that adultlike use of attention directing demonstrative, şu, is not mastered even at the age of six, while the distance contrasts are learned earlier. This language specific development reveals that designing referential forms in consideration of recipient's attentional status during conversation is a pragmatic feat that takes more than six years to develop.
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- 2006
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10. Role of the AZFd locus in spermatogenesis
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Sevilhan Artan, Oguz Cilingir, Muhammed Hamza Müslümanoğlu, Mehmet Turgut, Cavit Can, and Yusuf Ozyürek
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Gynecology ,Infertility ,Genetics ,medicine.medical_specialty ,Reproductive Medicine ,Multiplex polymerase chain reaction ,medicine ,Obstetrics and Gynecology ,Locus (genetics) ,Biology ,medicine.disease ,Spermatogenesis - Abstract
To determine the prevalence of Y-chromosome microdeletions among infertile men and to correlate the clinical presentation of the men with specific deletions, microdeletion analysis in 53 infertile men (30 nonobstructive azoospermic, 23 severely oligozoospermic patients), and 100 age-matched, fathered normospermic men who had fathered children was performed by the multiplex PCR with 18 different Y-chromosome-specific STS primer sets, spanning the AZFa, AZFb, AZFd, and AZFc regions. Detection of the same locus deletion of the AZFd region in three cases indicated the possible importance of the genes located in this region in spermatogenesis.
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- 2005
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11. Investigation of the effects of early stressful and late maternal separation on anxiety, behaviour, and pain threshold in newborn male and female rats
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Golgeli, A., primary, Yazgan, K., additional, Yıldırım, R.T., additional, Ince, Z., additional, Sarıca, Z., additional, Salim, M.O., additional, and Ozyürek, O., additional
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- 2016
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12. [Untitled]
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Atif Akdas, Levent Türkeri, Hakan Özveri, A. Ertuğrul, and M Ozyürek
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Nephrology ,Kidney ,medicine.medical_specialty ,biology ,business.industry ,Urology ,Calcium channel ,Ischemia ,medicine.disease ,medicine.anatomical_structure ,Endocrinology ,Internal medicine ,medicine ,biology.protein ,Verapamil ,Immunohistochemistry ,Diltiazem ,Epidermal growth factor receptor ,business ,medicine.drug - Abstract
This study was aimed to investigate Epidermal Growth Factor Receptor (EGF-R) expression after ischaemic injury in renal tissue and the effects of calcium channel blockers in the prevention of damage due to ischaemic insult. Simple nephrectomy was performed in a group of Sprague-Dawley rats, and kidneys were grouped according to cold ischaemia time (1, 6, 12, 24 and 48 hours, respectively) and to the type of calcium channel blockers (diltiazem and verapamil) used. EGF-R expression status was investigated in each group by immunohistochemistry on paraffin sections. Overall expression of EGF-receptor was detected in 8 822.8%) kidneys. In terms of localization of EGF-receptor expression cortical tubular staining was detected in 8 (100%) kidneys, medullar tubular staining in (62.5%) kidneys and glomerular mesangial staining in 5 (62.5%) kidneys. There was no difference between various ischaemia times and different calcium channel blockers used. It has been concluded that hypoxia and cold ischaemia causes widespread down-regulation of EGF-receptor expression in renal tissue regardless of treatment with calcium channel blockers.
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- 1999
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13. Bcl-2 and p53 overexpression as associated risk factors in transitional cell carcinoma of the bladder
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M Ozyürek, Atif Akdas, Levent Türkeri, and F. Atuğ
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Nephrology ,Carcinoma, Transitional Cell ,medicine.medical_specialty ,Programmed cell death ,Bladder cancer ,business.industry ,Urology ,Prognosis ,medicine.disease ,Immunohistochemistry ,Transitional cell carcinoma ,Proto-Oncogene Proteins c-bcl-2 ,Urinary Bladder Neoplasms ,Cytoplasm ,Internal medicine ,Carcinoma ,medicine ,Cancer research ,Humans ,Neoplasm Recurrence, Local ,Tumor Suppressor Protein p53 ,Stage (cooking) ,business - Abstract
Bcl-2 and p53 genes are implicated in cell cycle regulation with roles on programmed cell death. Consequently, presence of Bcl-2 and nuclear accumulation of p53 were proposed to confer a growth advantage tumour cells. We have investigated their role as prognostic factors in fresh tumour samples from a cohort of twenty patients with transitional cell carcinoma of the bladder by immunohistochemical analysis in paired specimens. Expression of Bcl-2 was observed in 11 cases (69%) and nuclear p53 accumulation in 9 (45%). In the presence of Bcl-2 protein expression, tumours showed a slightly higher rate of recurrence (55% vs. 40%) and significantly more progression (36% vs. 0%). Recurrence and progression rates were not significantly different in tumours with and without nuclear p53 overexpression (recurrence rates 56% vs. 55% and progression rates 33% vs. 27%, respectively). Grade and stage appeared as important prognosticators since 75% of grade 3 tumours showed recurrence and 50% progressed in contrast to 44% and 13%, respectively, of grades 1 and 2 tumours. Similarly, 50% of Ta-T1 tumours recurred and 20% progressed, while these rates were 75% and 75% for T2-T3 tumours. Also, expression of Bcl-2 and nuclear accumulation of p53 correlated with grade. In grade 3 tumours, 75% showed nuclear p53 overexpression and 80% cytoplasmic Bcl-2 protein. These figures were 25% and 64% for grades 1 and 2 tumours. In conclusion, Bcl-2 protein expression in transitional cell carcinoma appears to be associated with a poorer prognosis and together with nuclear p53 overexpression they are associated with tumour de-differentiation.
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- 1998
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14. Percutaneous retrieval of a chronic catheter fragment from the left ventricle in a child
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Dolunay, Gürses, A Ruhi, Ozyürek, Ertürk, Levent, and Zülal, Ulger
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Heart Defects, Congenital ,Catheters, Indwelling ,Foreign-Body Migration ,Child, Preschool ,Heart Ventricles ,Humans ,Female - Abstract
Embolization of a catheter fragment is a very rarely seen complication, and few cases have been reported in children. Catheter fragments must be urgently extracted due to life-threatening complications. Most catheter fragments are removed very soon after being lost in the cardiovascular system, including the venous system and right side of the heart. In our report, we describe a child with catheter fragment, which was removed from the left ventricle 32 days after embolization. This catheter fragment was successfully retrieved percutaneously using a gooseneck snare catheter through the femoral artery.
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- 2012
15. Elastic properties of the abdominal aorta in the children with bicuspid aortic valve: an observational study
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Gürses D, Ozyürek AR, Levent E, and Ulger Z
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cardiovascular system ,Adolescent ,Aorta, Thoracic/diagnostic imaging/*physiopathology ,Aortic Valve/*abnormalities ,Aortic Valve Insufficiency/diagnostic imaging/*physiopathology ,Blood Flow Velocity ,Case-Control Studies ,Child ,Cross-Sectional Studies ,Echocardiography ,Elasticity ,Female ,Heart Defects, Congenital/diagnostic imaging/*physiopathology ,Humans ,Male ,Regression Analysis ,Severity of Illness Index - Abstract
OBJECTIVE: Abnormalities of the aortic root and ascending aorta are common in patients with a bicuspid aortic valve (BAV). The aim of this study was to evaluate the stiffness of the abdominal aorta in children with BAV. METHODS: In this cross-sectional observational study, we evaluated 35 children with normally functioning or mildly regurgitant BAV and 35 healthy children as controls. All children were noninvasively evaluated with transthoracic echocardiography. Annulus of aorta and abdominal aorta diameters were measured. Aortic strain (S), pressure strain elastic modulus (Ep), pressure strain normalized by diastolic pressure (Ep*), aortic stiffness β index (βSI) and, aortic distensibility (DIS) were calculated using the measured data. In evaluation of the data Student's t-test, Chi-square test, Pearson's correlation and multivariate linear regression analysis were used. RESULTS: Diameter of the aortic annulus was found significantly larger in the children with BAV than the control group (p0.05). The children with BAV exhibited significantly lower S (0.210 ± 0.04/0.267 ± 0.07, p0.05). CONCLUSION: Bicuspid aortic valve is associated with an increased abdominal aortic stiffness in children. However, impaired abdominal aortic elasticity is not due to abdominal aortic dilatation. These findings require validation by further studies.
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- 2012
16. Percutaneous retrieval of a chronic catheter fragment from the left ventricle in a child
- Author
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Gürses D, Ozyürek AR, Levent E, and Ulger Z
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Catheters, Indwelling/*adverse effects ,Child, Preschool ,Female ,Foreign-Body Migration/*therapy ,Heart Defects, Congenital/*surgery ,Heart Ventricles ,Humans - Abstract
Embolization of a catheter fragment is a very rarely seen complication, and few cases have been reported in children. Catheter fragments must be urgently extracted due to life-threatening complications. Most catheter fragments are removed very soon after being lost in the cardiovascular system, including the venous system and right side of the heart. In our report, we describe a child with catheter fragment, which was removed from the left ventricle 32 days after embolization. This catheter fragment was successfully retrieved percutaneously using a gooseneck snare catheter through the femoral artery.
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- 2012
17. Comparison of effects of static, proprioceptive neuromuscular facilitation and Mulligan stretching on hip flexion range of motion: a randomized controlled trial
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Senduran Yıldırım, Meric, primary, Ozyürek, Seher, additional, Celiker Tosun, Ozge, additional, Uzer, Sevil, additional, and Gelecek, Nihal, additional
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- 2016
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18. A computational study on the characteristics of airflow in bilateral abductor vocal fold immobility
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M Kürşat, Gökcan, D Funda, Kurtuluş, Evren, Ustüner, Elif, Ozyürek, G Gökçen, Kesici, S Ceyhan, Erdem, Gürsel, Dursun, and Cemil, Yağci
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Adult ,Laryngoscopy ,Vital Capacity ,Video Recording ,Peak Expiratory Flow Rate ,Vocal Cords ,Middle Aged ,Case-Control Studies ,Forced Expiratory Volume ,Humans ,Computer Simulation ,Female ,Neural Networks, Computer ,Stroboscopy ,Pulmonary Ventilation ,Tomography, Spiral Computed ,Vocal Cord Paralysis ,Aged - Abstract
To evaluate airway sufficiency and airflow dynamics in a group of patients who underwent a posterior transverse laser cordotomy (PTLC) procedure.Mixed methods research, university hospital setting.Sixteen patients who underwent a PTLC procedure volunteered to be involved in this study. Dyspnea levels, voice, and glottic opening in indirect laryngoscopy were evaluated subjectively. The airway was evaluated objectively by pulmonary function tests, and glottic areas were measured from axial computed tomography (CT) images. The control group consisted of 63 subjects from the tomography archive. For computational fluid dynamics (CFD) analyses, two subjects from the study group were chosen on the basis of obstruction level, and a normal female subject was selected from the control group. Cartesian coordinates for airway boundaries were determined from axial CT images, and a three-dimensional computational model of the larynx was constructed. Flow simulations were performed with two different flow conditions during inspiration. Comparison of velocity, static pressure, turbulence intensity, and wall shear stress distribution values were made between selected cases and control.Pulmonary data varied widely and did not correlate with the size of the glottic area or dyspnea level. CFD analyses revealed that in addition to obstruction at the glottic level, aerodynamic properties of the larynx are altered due to loss in muscular tonus. Also, the contour of the glottic opening was found to be very important in determining the character of airflow as laminar or turbulent.Patients have considerable differences in their flow patterns and force distributions during respiration. Patient-specific models may help in evaluation and treatment planning.
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- 2010
19. Cognitive functions in neurofibromatosis type 1 patients and unaffected siblings
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Emel, Erdoğan-Bakar, Mine, Cinbiş, Hamit, Ozyürek, Nurcihan, Kiriş, Sakir, Altunbaşak, and Banu, Anlar
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Male ,Neurofibromatosis 1 ,Adolescent ,Siblings ,Severity of Illness Index ,Young Adult ,Cognition ,Orientation ,Visual Perception ,Humans ,Learning ,Female ,Child ,Follow-Up Studies - Abstract
Attention, learning, and perceptual problems have been reported at various degrees and rates in neurofibromatosis type 1 (NF1). We aimed to define the cognitive profiles frequently associated with NF1. Children and adolescents with NF1 (n=58) were tested using Wechsler Intelligence Scales for Children-Revised (WISC-R), Judgment of Line Orientation, and Bender Visual-Motor Gestalt tests. Comparison groups were unaffected siblings of NF1 patients (n=20), children with attention deficit and hyperactivity disorder (ADHD, n=40), and normal children (n=40). No difference was found between familial or sporadic NF1 cases. Seventeen/58 (29%) of NF1 cases had a full scale IQ70. The subgroup of NF1 patients with full scale IQ80 (n=27) scored lower in WISC-R subtests measuring visual perception when compared to a healthy control group of similar intelligence, and lower in arithmetic but better in Bender-Gestalt and Judgment of Line Orientation tests when compared to an ADHD group of similar intelligence. These results indicate a high prevalence of mental retardation in a clinical NF1 series. NF1 patients who have normal intelligence may have impaired visual perception, but their visual perceptual problems are less than in ADHD. The tendency of unaffected siblings of NF1 patients to have mildly but consistently low test scores compared to healthy controls needs to be studied further for underlying genetic or environmental factors.
- Published
- 2010
20. Cupric ion reducing antioxidant capacity assay for antioxidants in human serum and for hydroxyl radical scavengers
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Reşat, Apak, Kubilay, Güçlü, Mustafa, Ozyürek, Burcu, Bektaşoğlu, and Mustafa, Bener
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Hydroxyl Radical ,alpha-Tocopherol ,Humans ,Bilirubin ,Biological Assay ,Ascorbic Acid ,beta Carotene ,Glutathione ,Oxidation-Reduction ,Antioxidants ,Copper ,Uric Acid - Abstract
Tests measuring the combined antioxidant effect of the nonenzymatic defenses in biological fluids may be useful in providing an index of the organism's capability to counteract reactive species known as pro-oxidants, resist oxidative damage, and combat oxidative stress-related diseases. The selected chromogenic redox reagent for the assay of human serum should be easily accessible, stable, selective, and respond to all types of biologically important antioxidants such as ascorbic acid, alpha-tocopherol, beta-carotene, reduced glutathione (GSH), uric acid, and bilirubin, regardless of chemical type or hydrophilicity. Our recently developed cupric reducing antioxidant capacity (CUPRAC) spectrophotometric method for a number of polyphenols and flavonoids using the copper(II)-neocuproine reagent in ammonium acetate buffer is now applied to a complete series of plasma antioxidants for the assay of total antioxidant capacity of serum, and the resulting absorbance at 450 nm is recorded either directly (e.g., for ascorbic acid, alpha-tocopherol, and glutathione) or after incubation at 50 degrees C for 20 min (e.g., for uric acid, bilirubin, and albumin), quantitation being made by means of a calibration curve. The lipophilic antioxidants, alpha-tocopherol and beta-carotene, are assayed in dichloromethane. Lipophilic antioxidants of serum are extracted with n-hexane from an ethanolic solution of serum subjected to centrifugation. Hydrophilic antioxidants of serum are assayed in the centrifugate after perchloric acid precipitation of proteins. The CUPRAC molar absorptivities, linear ranges, and TEAC (trolox equivalent antioxidant capacity) coefficients of the serum antioxidants are established, and the results are evaluated in comparison with the findings of the ABTS/TEAC reference method. The intra- and inter-assay coefficients of variation (CVs) are 0.7 and 1.5%, respectively, for serum. The CUPRAC assay proved to be efficient for glutathione and thiol-type antioxidants, for which the FRAP (ferric reducing antioxidant potency) test is basically nonresponsive. The additivity of absorbances of all the tested antioxidants confirmed that antioxidants in the CUPRAC test do not chemically interact among each other so as to cause an intensification or quenching of the theoretically expected absorbance, and that a total antioxidant capacity (TAC) assay of serum is possible. As a distinct advantage over other electron-transfer based assays (e.g., Folin, FRAP, ABTS, DPPH), CUPRAC is superior in regard to its realistic pH close to the physiological pH, favorable redox potential, accessibility and stability of reagents, and applicability to lipophilic antioxidants as well as hydrophilic ones. The CUPRAC procedure can also assay hydroxyl radicals, being the most reactive oxygen species (ROS). As a more convenient, efficient, and less costly alternative to HPLC/electrochemical detection techniques and to the nonspecific, low-yield TBARS test, we use p-aminobenzoate, 2,4- and 3,5-dimethoxybenzoate probes for detecting hydroxyl radicals generated from an equivalent mixture of [Fe(II)+EDTA] with hydrogen peroxide. The produced hydroxyl radicals attack both the probe and the water-soluble antioxidants in 37 degrees C-incubated solutions for 2 h. The CUPRAC absorbance of the ethylacetate extract due to the reduction of Cu(II)-neocuproine reagent by the hydroxylated probe decreases in the presence of (.)OH scavengers, the difference being proportional to the scavenging ability of the tested compound. The developed method is less lengthy, more specific, and of a higher yield than the classical TBARS assay.
- Published
- 2010
21. Malignancy-associated hemophagocytic lymphohistiocytosis in pediatric cases: a multicenter study from Turkey
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Tiraje, Celkan, Su, Berrak, Elif, Kazanci, Emel, Ozyürek, Sule, Unal, Canan, Uçar, Sebnem, Yilmaz, and Aytemiz, Gürgey
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Male ,Leukemia, Myeloid, Acute ,Adolescent ,Turkey ,Child, Preschool ,Humans ,Antineoplastic Agents ,Female ,Precursor Cell Lymphoblastic Leukemia-Lymphoma ,Child ,Lymphohistiocytosis, Hemophagocytic ,Retrospective Studies - Abstract
This study evaluates the clinical and laboratory data of children with secondary hemophagocytic lymphohistiocytosis (sHLH) related to malignancy. Charts of patients who met the diagnostic criteria for sHLH associated with malignancy between January 2000-2006 at six different hospitals in Turkey were reviewed retrospectively. The diagnosis of HLH had been established by bone marrow aspiration in 27 patients, cerebrospinal fluid and bone marrow aspiration in one patient and lung-liver biopsy in another. Twenty-nine children were diagnosed as having sHLH related to malignancy. Twenty cases (18 ALL and 2 AML) with acute leukemia (10 girls/10 boys, median age: 8 years [3-14 years]) were found to have sHLH. Five patients with acute leukemia had HLH at the time of diagnosis (Group 1a), and 15 patients with acute leukemia were diagnosed as having sHLH during therapy (Group 1b), namely reactive sHLH associated with the chemotherapy. Nine patients, including two cases each of rhabdomyosarcoma, neuroblastoma, Hodgkin disease, and non-Hodgkin lymphoma (NHL) and one case with Langerhans cell histiocytosis, were diagnosed as having concomitant hemophagocytosis at the initial evaluation of the tumor (Group 2). Fever, anemia, and hypertriglyceridemia were present in all sHLH cases of all three groups. Hepatomegaly was detected in 60.0%, 73.3%, and 88.8% of the three groups, respectively. Splenomegaly was more frequent in patients of Groups 1a (60.0%) and 2 (88.8%) than in those of Group 1b, the reactive ones (13.3%). Hypofibrinogenemia was detected in all patients of Group 1a and Group 2. Low level of fibrinogen was present in 91.6% of patients in Group 1b. All patients in Group 1b (100%) had neutropenia and thrombocytopenia. Neutropenia was found at rates of 60.0% and 55.5% in Group 1a and Group 2, respectively. Thrombocytopenia was detected in 80.0% of patients in Group 1a and 77.7% in Group 2. The overall mortality rate was 34.4% (10 cases) in our series of 29 children with sHLH; 50% of deaths were directly attributable to HLH. Pediatric malignancy-associated HLH patients have been commonly described as case presentations or in a review of the literature. We believe that our cohort, compiling 29 children regarding the association between malignancy and HLH, will be useful for pediatricians who are interested in this still mysterious topic.
- Published
- 2009
22. The relation of arterial stiffness with intrauterine growth retardation
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Ertürk, Levent, Tahir, Atik, Sükran, Darcan, Zülal, Ulger, Damla, Gökşen, and A Ruhi, Ozyürek
- Subjects
Male ,Fetal Growth Retardation ,Infant, Newborn ,Muscle, Smooth, Vascular ,Cardiovascular Diseases ,Echocardiography ,Reference Values ,Risk Factors ,Infant, Small for Gestational Age ,Humans ,Female ,Vascular Resistance ,Aorta, Abdominal ,Child ,Retrospective Studies - Abstract
Much epidemiological evidence has linked low birthweight with late cardiovascular risk. Intrauterine growth retardation (IUGR) is associated with the increased risk of cardiovascular disease in adult life; it is unclear whether the relationship is present at younger ages. We evaluated whether abdominal aortic stiffness was altered in patients with IUGR (born at term with birthweight small for gestational age) in younger ages.Thirty-two (24 girls and eight boys) IUGR children aged 8.77 +/- 2.05 years were enrolled in the study. The birthweight was traced from the medical records. Their gestational ages were 38.9 +/- 0.85 weeks and birthweights 2130 +/- 198 g, respectively. Thirty-one healthy subjects who had normal gestational age and birthweight, matched for age and sex were recruited as a control group. Aortic strain, pressure strain elastic modulus (Ep), and normalized Ep and aortic distensibility were measured by a sphygmomanometer and transthoracic echocardiography in all subjects from the abdominal aorta.There was no statistically significant difference between the study and the control groups in sex, mean age, body mass index, lipid profile, leptin, insulin-like growth factor-1 or insulin-like growth factor binding protein 3. In IUGR children, aortic strain (0.201 +/- 0.027 vs 0.254 +/- 0.031, P0.001) and aortic distensibility (1.08 +/- 0.19 vs 1.42 +/- 0.24, P0.001) were significantly lower compared with the control group. However Ep (188 +/- 36.2 vs 146 +/- 27.1, P0.001) and normalized Ep (2.97 +/- 0.40 vs 2.1 +/- 0.39, P0.001) were significantly higher in IUGR patients.This study demonstrates that abdominal aortic stiffness is increased in IUGR patients. These data suggest that prenatal events could be related to cardiovascular risk in later life.
- Published
- 2009
23. Cupric ion reducing antioxidant capacity assay for food antioxidants: vitamins, polyphenolics, and flavonoids in food extracts
- Author
-
Reşat, Apak, Kubilay, Güçlü, Mustafa, Ozyürek, Burcu, Bektas Oğlu, and Mustafa, Bener
- Subjects
Flavonoids ,Polyphenols ,Ascorbic Acid ,Vitamins ,Oxidants ,Antioxidants ,Beverages ,Solutions ,Phenols ,Food ,Spectrophotometry ,Calibration ,Biological Assay ,Prunus ,Oxidation-Reduction ,Copper - Abstract
Antioxidants are health beneficial compounds through their combat with reactive oxygen and nitrogen species and free radicals that may cause tissue damage leading to various diseases. This work reports the development of a simple and widely applicable antioxidant capacity index for dietary polyphenols, vitamins C and E, and plasma antioxidants utilizing the copper(II)-neocuproine (Cu(II)-Nc) reagent as the chromogenic oxidizing agent. This novel method based on an electron-transfer mechanism was named by our research group as 'cupric reducing antioxidant capacity', abbreviated as the CUPRAC method. The method is comprised of mixing the antioxidant solution with aqueous copper(II) chloride, alcoholic neocuproine, and ammonium acetate aqueous buffer at pH 7, and subsequently measuring the developed absorbance at 450 nm after 30 min. Since the color development is fast for compounds like ascorbic acid, gallic acid, and quercetin but slow for naringin and naringenin, the latter compounds are assayed after incubation at 50 degrees C on a water bath for 20 min. The flavonoid glycosides are hydrolyzed to their corresponding aglycones by refluxing in 1.2 M: HCl-containing 50% MeOH so as to exert maximal reducing power towards Cu(II)-Nc. The CUPRAC antioxidant capacities of synthetic mixtures are equal to the sum of individual capacities of antioxidant constituents, indicating lack of chemical deviations from Beer's law. Tests on antioxidant polyphenols demonstrate that the highest CUPRAC capacities are observed for epicatechin gallate, epigallocatechin gallate, quercetin, fisetin, epigallocatechin, catechin, and caffeic acid in this order, in accord with the number and position of the -OH groups as well the conjugation level of the molecule. The parallelism of the linear calibration curves of pure antioxidants in water and in a given complex matrix (plant extract) demonstrates that there are no chemical interactions of interferent nature among the solution constituents, and that the antioxidant capacities of the tested antioxidants are additive, in conformity to the Beer's law. For individual determination of ascorbic acid in fruit juices with a modified CUPRAC procedure, flavonoids are pre-extracted as their La(III) complexes prior to assay. For apricot extracts, a modified version of the CUPRAC assay based on anion exchange separation at pH 3 is applied, since sulfited-dried sample extracts contain the hydrosulfite anion interfering with the determination. For herbal tea infusions, the standard CUPRAC protocol is applied. The CUPRAC reagent is stable, easily accessible, low-cost, and is sensitive toward thiol-type antioxidants unlike FRAP. The reaction is carried out at nearly physiological pH as opposed to the acidic pH of FRAP or to the alkaline pH of Folin methods, constituting a basic advantage for the realistic assay of biological fluids.
- Published
- 2008
24. Human soluble tumor necrosis factor receptor I (sTNF-RI) and interleukin-I receptor antagonist (IL-I Ra) in different stages of acute rheumatic fever
- Author
-
Necil, Kütükçüler, Neslihan E, Karaca, Betül Y, Sözeri, Güldane, Koturoğlu, Zafer, Kurugöl, Ruhi A, Ozyürek, and Güzide, Aksu
- Subjects
Male ,Receptors, Tumor Necrosis Factor, Type I ,Case-Control Studies ,Acute Disease ,Rheumatic Heart Disease ,Humans ,Receptors, Interleukin-1 ,Female ,Child ,Severity of Illness Index - Abstract
Acute rheumatic fever (ARF) results from an autoimmune response to infection with group A streptococci. Serum concentrations of two anti-inflammatory cytokines, interleukin-I receptor antagonist (IL-IRa) and human soluble tumor necrosis factor receptor I (sTNF-RI) were determined in patients with ARF at the time of admission and 3 months after treatment in order to evaluate changes in cytokine concentrations occurring during different stages of the disease.Serum concentrations of two anti-inflammatory cytokines, IL-I Ra and sTNF-RI , were investigated in children with ARF at the time of admission (n=21) and after 3 months following the cessation of treatment (n=15). The sTNF-RI and sIL-IRa were measured quantitatively in serum using enzyme-linked immunosorbent assay (ELISA).Levels of IL-1Ra and sTNF-RI were found to be significantly higher during acute phase and remission period of ARF when compared to age-matched healthy controls (p=0.001 and p=0.0001, respectively).Our study demonstrated that two anti-inflammatory cytokines, serum sTNFRI and IL-1Ra, are increased in acute and remission stages of ARF reflecting activation of the cellular immune response. We suggest this increase might probably be generated in an effort to counteract the already increased concentrations of proinflammatory cytokines.
- Published
- 2008
25. The role of splenectomy in children with juvenile myelomonocytic leukemia
- Author
-
Emel, Ozyürek, Mualla, Cetin, Murat, Tuncer, and Gönül, Hiçsönmez
- Subjects
Male ,Treatment Outcome ,Child, Preschool ,Splenectomy ,Humans ,Infant ,Female ,Leukemia, Myelomonocytic, Acute ,Retrospective Studies - Abstract
Splenectomy has been performed as a palliative treatment both in adults and children with myelodysplastic syndrome (MDS). However, there is no report describing the course after splenectomy in children with MDS. The aim of this study was to evaluate the impact of splenectomy on the outcome of six children with juvenile myelomonocytic leukemia (JMML) who had no HLA identical donor and who became unresponsive to chemotherapy. Persistent thrombocytopenia, increased erythrocyte transfusion requirement and massive splenomegaly were the indications for splenectomy. Hemoglobin values and platelet counts improved following splenectomy in five out of the six patients. Erythrocyte transfusion requirements decreased and none of the patients who responded received erythrocyte transfusion for at least six months. More importantly, the quality of life improved markedly. No mortality related to splenectomy was observed. In conclusion, splenectomy may be considered as a safe supportive treatment approach for some children with JMML.
- Published
- 2007
26. [Ebstein's anomaly with coarctation of the aorta and neonatal balloon angioplasty]
- Author
-
Bedir, Akyol, A Ruhi, Ozyürek, Dolunay, Gürses, Ertürk, Levent, and Zülal, Ulger
- Subjects
Ebstein Anomaly ,Radiography ,Infant, Newborn ,Humans ,Abnormalities, Multiple ,Angioplasty, Balloon ,Aortic Coarctation ,Ultrasonography - Published
- 2006
27. A very rare case of polysplenia syndrome with congenital diffuse pulmonary arteriovenous fistulas
- Author
-
Dolunay, Gürses, Zülal, Ulger, Ertürk, Levent, and A Ruhi, Ozyürek
- Subjects
Arteriovenous Malformations ,Heart Defects, Congenital ,Pulmonary Veins ,Child, Preschool ,Hemodynamics ,Humans ,Abnormalities, Multiple ,Female ,Syndrome ,Pulmonary Artery ,Spleen - Abstract
A five-year-old girl patient was admitted with cyanosis and dyspnea, which started from birth. She had small telangiectatic lesions on her face and cerebral arteriovenous malformation, but no family history of hereditary hemorrhagic telangiectasia. Contrast echocardiography and pulmonary angiography demonstrated diffuse pulmonary arteriovenous fistulas. The patient was diagnosed as polysplenia syndrome characterized with left atrial isomerism, interrupted inferior vena cava, azygous continuation to the superior vena cava, and hepatic veins draining to the right atrium. In contrast to the other polysplenia syndrome cases, in this patient, pulmonary arteriovenous fistulas were not associated with cavopulmonary anastomoses or liver disease.
- Published
- 2006
28. Clonal monosomy 7 in a megakaryoblastic leukemia developed on the basis of Fanconi anemia
- Author
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Feride Iffet Sahin, Başak Yilmaz, Hatice Emel Ozyürek, Bulent Alioglu, Zerrin Yilmaz, Namik Ozbek, and Ö. Özalp
- Subjects
Adolescent ,Sepsis ,Anabolic Agents ,Monosomy ,Fanconi anemia ,Leukemia, Megakaryoblastic, Acute ,hemic and lymphatic diseases ,medicine ,Humans ,Glucocorticoids ,Chromosome 7 (human) ,Chromosome Aberrations ,business.industry ,Osteomyelitis ,Myeloid leukemia ,Karyotype ,Hematology ,medicine.disease ,Fanconi Anemia ,Oncology ,Oxymetholone ,Pediatrics, Perinatology and Child Health ,Immunology ,Drug Therapy, Combination ,Female ,business ,Megakaryoblastic leukemia ,Chromosomes, Human, Pair 7 - Abstract
A 13-year-old girl with a history of Fanconi anemia developed acute myeloid leukemia of the M7 subtype with a 45,XX,-7 karyotype, which is rare in M7 subtype. Treatment protocols were set up, but she died of sepsis and osteomyelitis during induction.
- Published
- 2005
29. Kawasaki disease recurrence with cardiac tamponade
- Author
-
Zülal, Ulger, Ertürk, Levent, Rahmi, Ozdemir, and Arif Ruhi, Ozyürek
- Subjects
Diagnosis, Differential ,Recurrence ,Humans ,Immunoglobulins ,Female ,Pericardiocentesis ,Mucocutaneous Lymph Node Syndrome ,Child ,Infusions, Intravenous ,Cardiac Tamponade ,Ultrasonography - Published
- 2005
30. Usefulness of the myocardial performance index (MPI) for assessing ventricular function in obese pediatric patients
- Author
-
Ertürk, Levent, Damla, Gökşen, Arif Ruhi, Ozyürek, Sükran, Darcan, and Mahmut, Coker
- Subjects
Male ,Adolescent ,Hypertension ,Myocardial Infarction ,Humans ,Reproducibility of Results ,Female ,Obesity ,Child ,Myocardial Contraction ,Algorithms ,Echocardiography, Doppler ,Ventricular Function, Left - Abstract
Obesity is a prevalent pathological and nutritional disease relating to clinical and sub-clinical disorders. Furthermore, its complications exert a major impact on cardiovascular risk. Myocardial performance index (MPI) has been described as noninvasive Doppler measures of left ventricular (LV) function. The purpose of this study was to assess MPI using transthoracic Doppler echocardiography in normotensive obese and hypertensive obese pediatric patients and in a control group, and to investigate the relationship between MPI and LV mass, and LV systolic and diastolic functions. The study group consisted of 25 healthy cases (M/F: 13/12) as a control group (Group I), 25 normotensive-obese patients (M/F: 13/12) (Group II) and 25 hypertensive-obese patients (M/F: 14/11) (Group III). The mean ages were 12.1+/-1.8, 11.9+/-1.5 and 12.4+/-1.4 years, respectively. Cholesterol levels and body mass index (BMI) were higher in the hypertensive-obese group. The MPI values were 0.37+/-0.04, 0.43+/-0.08 and 0.51+/-0.11 in the three groups, respectively. MPI measurements, LV mass fractional shortening (FS), ejection fraction (EF) and mitral E/A ratio were found significantly different, especially in the hypertensive-obese group. These findings may be important to determine the relationship between obesity and cardiovascular risk factors in pediatric ages. MPI may be useful in determining the relationship between them.
- Published
- 2005
31. [Periarticular fractures of the knee in child and adolescent athletes]
- Author
-
N Reha, Tandoğan, Oğuz, Karaeminoğullari, Ayhan, Ozyürek, and Salim, Ersözlü
- Subjects
Adolescent ,Turkey ,Child Health Services ,Salter-Harris Fractures ,Knee Injuries ,Radiography ,Tibial Fractures ,Arthroscopy ,Adolescent Health Services ,Fracture Fixation ,Athletic Injuries ,Humans ,Child ,Femoral Fractures - Abstract
Most of the sports-related lower limb injuries in children and adolescents involve the knee. Due to the physiological characteristics of the growing skeleton, fractures are more common than ligamentous injuries in this age group. The most frequent type of injury is distal femoral physeal fractures followed by proximal tibial physeal injuries. Tibial tubercle avulsions are rare. Reduction should be gently performed and fixation methods should ensure that no further damage to the physeal plate occurs. Even after proper treatment, there is a significant risk for subsequent leg length discrepancies and/or angular deformities, requiring that children be followed closely for at least two years. Arthroscopic techniques have become popular in recent years in the treatment of displaced tibial eminence fractures. Residual anterior laxity remains an important problem after the healing of these fractures.
- Published
- 2004
32. [Using of fibrinolytics in the treatment of complicated parapneumonic effusion and empyema in children]
- Author
-
Ayten Pamukçu, Uyan, Hamit, Ozyürek, and Ebru, Yilmaz
- Subjects
Emphysema ,Pleural Effusion ,Fibrinolytic Agents ,Drainage ,Humans ,Thrombolytic Therapy ,Child - Abstract
Bacterial pneumonia is associated with a high incidence of pleural effusions in children. These parapneumonic effusions usually resolve spontaneously if patients are treated with appropriate antibiotics. However, a small percentage of parapneumonic effusions will become complicated, either loculated non-purulent fluid or an empyema. The traditional therapeutic approaches for complicated parapneumonic effusions includes catheter drainage and systemic antibiotics. Tube drainage often fails if the fluid is loculated by fibrinous adhesions and surgical operation require. Intrapleural administration of fibrinolytics is an effective treatment for complicated parapneumonic effusions and pleural empyemas, improving the drainage without causing systemic fibrinolysis or local hemorrhage. The global success rate were between 44% and 100%, in most cases more than 80%. Both streptokinase and urokinase have been used for this purpose but there are few reports of their use in the children. Intrapleural streptokinase and urokinase are equally efficacious in treating complicated parapneumonic effusions and empyemas. Intrapleural instillation of fibrinolytics is an effective and safe mode of treatment for complicated parapneumonic effusions and pleural empyemas, and may reduce the need for more invasive surgical procedures.
- Published
- 2004
33. Evaluation of Nerve Conduction Studies in Obese Children With Insulin Resistance or Impaired Glucose Tolerance
- Author
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Ince, Hülya, primary, Taşdemir, Haydar Ali, additional, Aydin, Murat, additional, Ozyürek, Hamit, additional, and Tilki, Hacer Erdem, additional
- Published
- 2014
- Full Text
- View/download PDF
34. Trauma as a risk factor for thrombosis in children: a report of three cases
- Author
-
Emel, Ozyürek, Nesrin, Beşbaş, Deniz, Aslan, and Aytemiz, Gürgey
- Subjects
Male ,Risk Factors ,Humans ,Infant ,Wounds and Injuries ,Female ,Thrombosis ,Child - Abstract
Thromboembolism is described as a multifactorial disorder including both congenital and acquired risk factors in children. Among these, trauma has been suggested as a possible risk factor for development of thrombosis. In this study, we reviewed the data of 158 children with thrombosis. Trauma was the major risk factor for thrombosis in three children. Cerebral infarction and cerebral venous thrombosis were detected in two patients, and thrombosis of the inferior vena cava and left renal vein in the third. In addition, the factor V Leiden mutation was demonstrated in two trauma patients with thrombosis.
- Published
- 2003
35. Evaluation of aortic stiffness in tobacco-smoking adolescents
- Author
-
Ertürk, Levent, Arif Ruhi, Ozyürek, and Zülal, Ulger
- Subjects
Male ,Adolescent ,Turkey ,Arteriosclerosis ,Echocardiography ,Case-Control Studies ,Smoking ,Aortic Diseases ,Humans ,Blood Pressure ,Female - Abstract
To measure the aortic stiffness in tobacco-smoking adolescents and to investigate its relationship to tobacco smoke.Aortic strain (S), pressure strain elastic modulus (E(p)), and normalized E(p) (E(p)*) in tobacco-smoking adolescents and the healthy control group were measured by a sphygmomanometer with cuff and transthoracic echocardiography. The study group consisted of 30 healthy cases (M/F: 27/3) as a control group and 30 tobacco-smoking volunteer adolescents (M/F: 28/2). Unpaired Student's t-test was used for comparison of these groups.The mean ages were 16.1 +/- 1.8 years and 16.2 +/- 1.4 years, respectively. The number of cigarettes smoked per day was 31 +/- 7.1 and the duration of smoking was 3.4 +/- 1.1 years. S, E(p) and E(p)* measurements of tobacco smokers were different than the control groups' and this difference was statistically significant. S values were significantly higher in nonsmokers than in smokers; whereas E(p) and E(p)* values were significantly higher in smoker group.This study demonstrated that measurement of aortic stiffness with S, E(p), and E(p)* can be used as an early indicator of atherosclerosis in tobacco-smoking adolescents.
- Published
- 2003
36. Cardiac perforation due to crochet hook: a pediatric patient with penetrating cardiac injury
- Author
-
Ertürk, Levent, Mehmet Tayyip, Arslan, Arif Ruhi, Ozyürek, Yüksel, Atay, Alp, Alayunt, and Aytül, Parlar
- Subjects
Diagnosis, Differential ,Heart Injuries ,Echocardiography ,Child, Preschool ,Humans ,Female ,Wounds, Stab ,Emergency Treatment ,Cardiac Tamponade - Published
- 2003
37. The effects of high dose methylprednisolone on apoptosis in children with acute lymphoblastic leukemia
- Author
-
D, Uçkan, S, Yetgin, M, Cetin, E, Ozyürek, H, Okur, D, Aslan, and M, Tuncer
- Subjects
Fas Ligand Protein ,Membrane Glycoproteins ,Dose-Response Relationship, Drug ,Gene Expression Regulation ,Proto-Oncogene Proteins c-bcl-2 ,Drug Evaluation ,Humans ,Apoptosis ,fas Receptor ,Precursor Cell Lymphoblastic Leukemia-Lymphoma ,Child ,Flow Cytometry ,Methylprednisolone - Abstract
Rapid leukemic cell kill at initial diagnosis of patients with acute lymphoblastic leukemia (ALL) has been shown to be associated with a favorable outcome. The aim of the present study was to investigate the effect of high dose methylprednisolone (HDMP) on in vivo blast cell apoptosis in children with ALL. Annexin V-binding and Fas (CD95), Fas ligand (FasL; CD95L), and Bcl-2 expression in PB blasts were determined in newly diagnosed children with ALL before and 4, 24, 96 h after initiation of HDMP treatment (n=20) or conventional dose steroids (CDS) (n=10) as the control group. A decrease in absolute blast count (from 40.8 x 09 to 21.4 x 109/l) associated with an increase in apoptosis (14.2 to 26.9%) (P0.05) was detected 4 h after initiation of HDMP. A significant increase in Fas and FasL expression was detected 96 h after HDMP. There was no significant change in apoptosis, Fas and FasL expression from baseline in the control group treated with CDS. The changes in Bcl-2 expression after treatment was not significant in both groups. The results of this preliminary study have shown that HDMP treatment was effective in inducing immediate (within 4 h) blast cell apoptosis. The contribution of Fas/FasL interaction in the rapid component of cell kill remains to be determined, as the increase in the expression of these molecules was evident later.
- Published
- 2003
38. Augmented cytotoxicity of estramustine in prostate cancer cell lines by N-acetyl-L-cysteine
- Author
-
M Ozyürek and Levent Türkeri
- Subjects
Oncology ,Cancer Research ,medicine.medical_specialty ,business.industry ,Urology ,Prostate cancer cell ,medicine.disease ,Prostate cancer ,Internal medicine ,Cancer research ,Medicine ,Estramustine ,business ,Cytotoxicity ,N-acetyl-L-cysteine ,medicine.drug - Abstract
Augmented cytotoxicity of estramustine in prostate cancer cell lines by N-acetyl-L-cysteine
- Published
- 2002
39. Augmented cytotoxicity of estramustine and etoposide combination in hormone refractory prostate cancer cell lines and association with TGF modulation
- Author
-
M Ozyürek, Levent Türkeri, Atif Akdas, and O Ayaz
- Subjects
Oncology ,Cancer Research ,medicine.medical_specialty ,business.industry ,Urology ,medicine.disease ,Hormone refractory prostate cancer ,Prostate cancer ,Cell culture ,Internal medicine ,medicine ,Estramustine ,business ,Cytotoxicity ,Etoposide ,medicine.drug ,Transforming growth factor - Abstract
Augmented cytotoxicity of estramustine and etoposide combination in hormone refractory prostate cancer cell lines and association with TGF modulation
- Published
- 2002
40. Lamellar ichthyosis: a case report
- Author
-
Hamit, Ozyürek, Ayşe, Kavak, and Murat, Alper
- Subjects
Male ,Child, Preschool ,Humans ,Ichthyosis, Lamellar - Abstract
Ichthyoses are divided into four groups according to clinical, histopathologic and genetic findings. Lamellar ichthyosis is one of them. The incidence of lamellar ichthyosis is believed to be approximately 1 per 100,000 to 300,000 live births. It is characterized by large, polygonal, grayish brown, and tightly adherent scales. We report a four-year-old boy with desquamative lesions since birth who had six-year-old sister with similar lesions, suggesting an autosomal recessive inheritance. His skin biopsy revealed hyperkeratosis with lamellae. There were no associated hair or neurological abnormalities. His clinical and histopathological findings were typical for isolated lamellar ichthyosis. Because of its rare occurrence, we report this case with a review of the literature.
- Published
- 2002
41. Apoptotic regression of prostatic tissue induced by short-term doxazosin treatment in benign prostatic hyperplasia
- Author
-
L N, Türkeri, M, Ozyürek, D, Ersev, and A, Akdaş
- Subjects
Male ,Time Factors ,Double-Blind Method ,Doxazosin ,Prostatic Hyperplasia ,Humans ,Apoptosis ,Prospective Studies ,Middle Aged ,Adrenergic alpha-Antagonists ,Aged - Abstract
Benign enlargement of the prostate comprises both hypertrophy and in particular hyperplasia of prostatic stromal and glandular compartments. Alpha adrenergic blockade has been shown to be effective in the management of BPH. Recent investigations have shown that this effect may in part be due to apoptosis.A total of 29 patients who were symptomatic due to BPH were enrolled into this prospective placebo controlled, double-blind randomized study and underwent prostatectomy at the end of the 4th week. Clinical efficacy was evaluated by a set of detailed investigations. Surgical specimens were analyzed by immunohistochemistry and tissue components of stroma, smooth muscle and glandular epithelium were calculated by a software on a computer after representative areas were scanned and captured as high resolution images. Apoptosis in each tissue specimen was analyzed by Terminal Deoxynucleotidyl Transferase End Labelling (TUNEL) method utilizing Biotin-16-dUTP.Both groups were similar in terms of baseline evaluation in all aspects. There was a steady decline in patients' urinary complaints as evidenced by International Prostate Symptom Score System (IPSS) in the doxazosin group compared to placebo. Uroflowmetric investigations on patients revealed that maximum flow rates in the active drug group increased throughout the study. Mean PSA levels decreased by 14% at the end of the study in the doxazosin group, while it increased by 11% in the placebo group. Average stroma to epithelial ratio in the doxazosin group was 2:1 in comparison to a value of 1:1 in the placebo group. The rate of apoptosis was 2.2% and 3.2% for the epithelial and stromal compartments, respectively, in the doxazosin group, and 1.2% and 2.7% for the placebo arm.These data suggest apoptosis as the possible underlying molecular mechanism partly responsible for the clinical efficacy and morphological changes induced by doxazosin treatment in BPH.
- Published
- 2001
42. Alteration of epidermal growth factor receptor expression following ischaemia of renal tissue
- Author
-
A, Ertuğrul, L N, Türkeri, M, Ozyürek, H, Ozveri, and A, Akdaş
- Subjects
ErbB Receptors ,Immunoenzyme Techniques ,Rats, Sprague-Dawley ,Random Allocation ,Kidney Tubules ,Evaluation Studies as Topic ,Ischemia ,Animals ,Down-Regulation ,Kidney ,Rats - Abstract
This study was aimed to investigate Epidermal Growth Factor Receptor (EGF-R) expression after ischaemic injury in renal tissue and the effects of calcium channel blockers in the prevention of damage due to ischaemic insult. Simple nephrectomy was performed in a group of Sprague-Dawley rats, and kidneys were grouped according to cold ischaemia time (1, 6, 12, 24 and 48 hours, respectively) and to the type of calcium channel blockers (diltiazem and verapamil) used. EGF-R expression status was investigated in each group by immunohistochemistry on paraffin sections. Overall expression of EGF-receptor was detected in 8 (22.8%) kidneys. In terms of localization of EGF-receptor expression cortical tubular staining was detected in 8 (100%) kidneys, medullar tubular staining in (62.5%) kidneys and glomerular mesangial staining in 5 (62.5%) kidneys. There was no difference between various ischaemia times and different calcium channel blockers used. It has been concluded that hypoxia and cold ischaemia causes widespread down-regulation of EGF-receptor expression in renal tissue regardless of treatment with calcium channel blockers.
- Published
- 2001
43. Influence of feeding regimens on non-invasive inferior vena cava and hepatic vein velocity measurements in infants
- Author
-
Z, Kurugöl, R, Ozyürek, C, Dorak, E, Levent, A, Egemen, and A, Parlar
- Subjects
Male ,Blood Volume ,Breast Feeding ,Humans ,Infant ,Female ,Infant Food ,Vena Cava, Inferior ,Hepatic Veins ,Blood Flow Velocity - Abstract
The aim of this study was to investigate the effects of feeding type and osmotic load on intravascular volume status. Ninety term, healthy infants 2 mo of age were included in the study. The breastfed and formula-fed groups each consisted of 45 infants. Echocardiographic examination was performed before and after feeding. The collapse index of the inferior vena cava (IVCIC) and right atrial pressure (RAP) were calculated. No statistically significant differences were found between before- and after-feeding values of IVCIC, RAP and hepatic vein velocities in breastfed infants. In the formula-fed group, after-feeding values of IVCIC were significantly lower and RAP, hepatic vein systolic and diastolic velocities were significantly higher compared to the before-feeding values. Most of the mothers (78%) were unsuccessful at preparing the formula at appropriate concentrations. No statistically significant differences were found between the before-and after-feeding values of IVCIC, RAP and hepatic vein velocities in infants being fed appropriately prepared formula. The after-feeding values of hepatic vein velocities were higher than those of before-feeding values; after-feeding values of IVCIC were lower than before-feeding values in infants being fed highly concentrated formula.The values of inferior vena cava indices and hepatic vein velocities were not effected by feeding in infants receiving appropriately concentrated formula, like those of infants receiving breast milk. However, feeding with highly concentrated formula may cause intravascular volume expansion.
- Published
- 2000
44. P.1.h.041 - Investigation of the effects of early stressful and late maternal separation on anxiety, behaviour, and pain threshold in newborn male and female rats
- Author
-
Golgeli, A., Yazgan, K., Yıldırım, R.T., Ince, Z., Sarıca, Z., Salim, M.O., and Ozyürek, O.
- Published
- 2016
- Full Text
- View/download PDF
45. Impaired IgG antibody production to pneumococcal polysaccharides in patients with ataxia-telangiectasia
- Author
-
O, Sanal, F, Ersoy, L, Yel, I, Tezcan, A, Metin, H, Ozyürek, S, Gariboglu, S, Fikrig, A I, Berkel, G T, Rijkers, and B J, Zegers
- Subjects
Adult ,Adolescent ,Opportunistic Infections ,Antibodies, Bacterial ,Pneumococcal Infections ,Immunoglobulin A ,Immunoglobulin Isotypes ,Pneumococcal Vaccines ,Ataxia Telangiectasia ,Streptococcus pneumoniae ,Child, Preschool ,Immunoglobulin G ,Bacterial Vaccines ,Humans ,Disease Susceptibility ,Child ,Respiratory Tract Infections - Abstract
Various factors seem to be etiologic in the susceptibility to sinopulmonary infections in ataxia-telangiectasia (A-T) patients, i.e., low serum and salivary IgA, low serum IgG2, and even aspiration of saliva. S. pneumoniae is a common pathogen responsible from pulmonary infections and impaired antibody response to polysaccharide antigens is seen in patients with IgG2 and IgA deficiency as well as patients with CVID and WAS. We studied IgG-type antibody production to six pneumococcal serotypes in 29 A-T patients by ELISA before and 3-4 weeks after pneumococcal vaccine. The response was considered positive when the antibody titer was10 U/ml but weak when the titer was 10-20 U/ml. Twenty-two of 29 (76%) patients did not respond to any of the serotypes, 5 (17%) showed a positive response to one serotype, 1 (3.4%) to two serotypes, and 1 (3.4%) to four serotypes. With conversion to gravimetric units (ng IgG/ml) and1800 ng/ml (300 ng Ab N/ml) considered a positive response, 5 of 29 (17.2%) patients showed a positive response (300 ng ab N/ml) to two or fewer serotypes. All patients tested produced IgG antibody to tetanus toxoid. Sixteen of 27 (59.3%) patients had low IgG2 and four (14.8%) had low IgG3 levels, while 18 (62.1%) of 29 patients had low serum IgA. No correlation was found either between serum Ig isotype levels and antipolysaccharide antibody response or between susceptibility to infection and antibody production. The mechanism responsible for disturbed antipolysaccharide (TI-2 antigen) antibody production in patients with A-T needs to be investigated. It may provide additional information on the function of the ATM gene product and be helpful in clarifying the role of B cells and contribution of T cells in TI-2 responses.
- Published
- 1999
46. The CHARGE association in a newborn infant
- Author
-
M, Akisü, F, Ozkinay, R, Ozyürek, A, Küçüktaş, and N, Kültürsay
- Subjects
Male ,Facial Asymmetry ,Infant, Newborn ,Humans ,Abnormalities, Multiple ,Ear ,Eye Abnormalities ,Syndrome ,Ductus Arteriosus, Patent ,Choanal Atresia ,Heart Septal Defects, Atrial ,Pedigree - Abstract
CHARGE association is the nonrandom association of congenital anomalies, including choanal atresia, coloboma, heart defects, retardation of growth and development, genital hypoplasia and ear abnormalities. We report a male newborn infant with CHARGE association. Other congenital abnormalities include micrognathia, high-arched palate, facial asymmetry, broad nasal bridge, hypertelorism, asymmetric eye size, and left microphthalmia. On radiologic examination, hemivertebrae were detected on the thoracal vertebrae. Although both autosomal and recessive transmission have been reported, most cases of CHARGE association have been sporadic (karyotype analysis is generally reported to be normal as in our patient). Transmission and recurrence risk of this association are not known. The presence of choanal atresia and/or coloboma must alert the clinician to search for other abnormalities for diagnosis of CHARGE association.
- Published
- 1998
47. The role of in vitro chemosensitivity tests to predict the clinical efficacy of antineoplastic agents in genito-urinary tumors
- Author
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L N, Türkeri, G, Akdaş, M, Ozyürek, and A, Akdaş
- Subjects
Adult ,Aged, 80 and over ,Male ,Predictive Value of Tests ,Humans ,Female ,Drug Screening Assays, Antitumor ,Middle Aged ,Urogenital Neoplasms ,Aged - Abstract
To develop an in vitro screening system to predict the response to treatment of common malignancies of the genito-urinary tract.Flow cytometric analysis and cytotoxicity assays (trypan blue and lactic dehydrogenase colorimetric tests) were performed on hormone resistant prostate cancer cell line PC-3 and primary transitional cell carcinoma samples treated with different antineoplastic agents and their combinations. Apoptosis induced by different agents was also investigated by previously established criteria.There were 9 bladder tumors (47.4%) in the study group that displayed drug resistance to at least one antineoplastic agent. When the drugs were examined individually, there was resistance to cis-platinum in 3 patients (15.8%), methotrexate in 6 (31.6%), vinblastine in 7 (36.8%), epirubicin in 2 and adriamycin in 2 patients (10.5%). Stratification of patients according to the stage of the tumor revealed statistically significant difference between the superficial and invasive tumors in terms of drug resistance (p0.05). In prostate cancer cell line vinblastine treatment resulted in a significant increase in S phase fraction. Percent cytotoxicity by trypan blue exclusion test was 26.1% and was significantly higher than the control group (8.7%, p0.002). Also, an increase in apoptotic index after the treatment was observed (44.4% and 12.1%, respectively; p0.0001).Both toxicity assays showed a very good correlation (p0.005) and can be used to evaluate the effects of different antineoplastic agents on individual tumors.
- Published
- 1998
48. A case of Marden-Walker syndrome with Dandy-Walker malformation
- Author
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Ali Rahmi Bakiler, A R Ozyürek, Müfit Arcasoy, Nazmi Narin, Cihangir Ozkinay, H Yüksel, Ferda Ozkinay, Aytül Parlar, and Ege Üniversitesi
- Subjects
congenital, hereditary, and neonatal diseases and abnormalities ,Heart disease ,Spontaneous movements ,Developmental Disabilities ,Central nervous system disease ,Arachnodactyly ,Marden–Walker syndrome ,Genetics ,medicine ,Humans ,Joint Contracture ,Marden Walker syndrome ,Genetics (clinical) ,medicine.diagnostic_test ,business.industry ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,Dandy Walker malformation ,Brain ,Infant ,Magnetic resonance imaging ,Anatomy ,Syndrome ,medicine.disease ,Magnetic Resonance Imaging ,Musculoskeletal Abnormalities ,ComputingMilieux_MANAGEMENTOFCOMPUTINGANDINFORMATIONSYSTEMS ,ComputingMethodologies_PATTERNRECOGNITION ,Face ,Female ,InformationSystems_MISCELLANEOUS ,business ,Dandy-Walker Syndrome ,Dandy-Walker malformation ,MRI - Abstract
PubMed ID: 7543036, A 5-month-old girl with Marden-Walker syndrome is presented. This is a rare autosomal recessive syndrome. So far, approximately 20 cases have been described in the literature. The patient was hospitalized because of difficulty in feeding and slow spontaneous movements. Her parents were first cousins. She was diagnosed with clinical findings of growth and motor retardation, typical facial appearance, congenital heart disease, arachnodactyly, joint contractures, and a Dandy-Walker malformation on magnetic resonance imaging. Copyright © 1995, Wiley Blackwell. All rights reserved
- Published
- 1995
49. Evaluation of Nerve Conduction Studies in Obese Children With Insulin Resistance or Impaired Glucose Tolerance.
- Author
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Ince, Hülya, Taşdemir, Haydar Ali, Aydin, Murat, Ozyürek, Hamit, and Tilki, Hacer Erdem
- Subjects
GLUCOSE tolerance tests ,OVERWEIGHT persons ,DIABETES complications ,INSULIN resistance ,JUVENILE diseases - Abstract
The aim of the study was to investigate nerve conduction studies in terms of neuropathic characteristics in obese patients who were in prediabetes stage and also to determine the abnormal findings. The study included 69 obese adolescent patients between April 2009 and December 2010. All patients and control group underwent motor (median, ulnar, tibial, and peroneal) and sensory (median, ulnar, sural, and medial plantar) nerve conduction studies and sympathetic skin response test. Sensory response amplitude of the medial plantar nerve was significantly lower in the patients with impaired glucose tolerance and insulin resistance. To our knowledge, the present study is the first study demonstrating the development of sensory and autonomic neuropathy due to metabolic complications of obesity in adolescent children even in the period without development of diabetes mellitus. We recommend that routine electrophysiological examinations be performed, using medial plantar nerve conduction studies and sympathetic skin response test. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
50. Lack of association between TNFα gene polymorphism at position –308 and risk of acute rheumatic fever in Turkish patients
- Author
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Berdeli, A., primary, Tabel, Y., additional, Celik, H. A., additional, Ozyürek, R., additional, Dogrusoz, B., additional, and Aydin, H. H., additional
- Published
- 2006
- Full Text
- View/download PDF
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