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Featured researches published by Osman Öztekin.


Journal of Clinical Laboratory Analysis | 2014

Ischemia-Modified Albumin May be a Novel Marker for the Diagnosis and Follow-up of Necrotizing Enterocolitis

Ibrahim Yakut; Cüneyt Tayman; Osman Öztekin; Fahri Karaca; Aydin Kosus

We investigate the efficacy of serial ischemia‐modified albumin (IMA) measurements in diagnosis and follow‐up of necrotizing enterocolitis (NEC), and compare its effectiveness with C‐reactive protein (CRP), interleukin‐6 (IL‐6), in NEC.


Pediatric Neurology | 2014

Effects of Hyperglycemia on the Developing Brain in Newborns

Cüneyt Tayman; Uluç Yiş; Ibrahim Hirfanoglu; Osman Öztekin; Guleser Goktas; Bulent Caglar Bilgin

BACKGROUND Hyperglycemia is a common problem in preterm neonates and is associated with increased risk of mortality and severe morbidities such as brain damage. However, available data about the effects of severity of hyperglycemia on the developing brain in the early life is limited. Therefore, we evaluated the effects of moderate and severe hyperglycemia on the developing brain. METHOD Thirty newborn Sprague-Dawley rats were randomly divided into three groups as control, moderate hyperglycemia (30% dextrose), and severe hyperglycemia (50% dextrose). Pups in the hyperglycemia groups were administered subcutaneous sterile dextrose solution at a dose of 4 mL/kg daily from the second day to the eleventh day of life. Blood glucose levels were measured every day in all study groups. Rat brain tissues were removed at the end of the study. Histopathologic and immunohistochemical (caspase-9, -8, and -3) examination and biochemical analysis including xanthine oxidase, total antioxidant status, total oxidant status, and malondialdehyde activities were performed. RESULTS Weight of the brain tissues in rats with hyperglycemia groups was significantly lower than the control group (P < 0.05). Weight of the brain tissues in rats with moderate hyperglycemia was lower than that of the severe hyperglycemia (P < 0.05). In the histopathologic and immunochemical evaluation, severity of brain damage and apoptosis were significantly higher in the severe hyperglycemia group, especially at the level of the hippocampus (P < 0.05). Tissue malondialdehyde, xanthine oxidase levels, and total oxidant status were significantly increased in the severe hyperglycemia group, whereas total antioxidant status was significantly decreased in the severe hyperglycemia group (P < 0.001). CONCLUSION Brain damaging effects of severe hyperglycemia were observed in the developing brains of the rat pups. It might be inferred that severe hyperglycemia can damage the developing brain especially in preterm infants.


Pediatric Neurology | 2013

The Effects of Intraperitoneal Pentoxifylline Treatment in Rat Pups With Hypoxic-Ischemic Encephalopathy

Salih Kalay; Osman Öztekin; Gönül Tezel; Hakan Aldemir; Emel Sahin; Sadi Köksoy; Mustafa Akcakus; Nihal Oygür

BACKGROUND The aim of this study was to evaluate the effects of postischemic treatment with pentoxifylline on the cytokine gene expressions and neuronal apoptosis in neonatal rat model of hypoxic-ischemic encephalopathy. METHODS Seven-day-old Wistar rat pups (n = 40) of either sex, delivered spontaneously, were used in this experimental study. Control group (n = 8): after median neck incision was made, neither ligation nor hypoxia was performed, ischemia group (n = 16): 0.5 mL of saline was injected intraperitoneally immediately after hypoxia. Pentoxifylline and ischemia groups (n = 16): the rat pups were administered intraperitoneally 60 mg/kg of pentoxifylline immediately after hypoxia. Eight rats from ischemia and pentoxifylline + ischemia groups were sacrificed 4 and 24 hours after drug administration. Control group mice were decapitated 4 hours after hypoxia. Caspase-3 activity, interleukin-1β, and tumor necrosis factor-α messenger RNA expression levels were studied in the left half of the brain. RESULTS Induction of cerebral ischemia increased tumor necrosis factor-α and interleukin-1β messenger RNA expression levels significantly at 4 hours and 24 hours following ischemia in the left ischemic hemispheres in the ischemia group as compared with the control group. Systemic administration of pentoxifylline immediately after hypoxic-ischemic encephalopathy significantly reduced the tumor necrosis factor-α and interleukin-1β messenger RNA expression levels in ischemic tissue as compared with the ischemia group. Caspase-3 activities in the left half of the brains of ischemia group were found to be increased significantly as compared with control group. Caspase-3 activities in the brains of pentoxifylline + ischemia groups were significantly lower than in that of ischemia group. CONCLUSIONS Based on the significantly lower interleukin-1β and tumor necrosis factor-α gene expression measured after 4 and 24 hours and significantly reduced caspase-3 activity measured colorimetrically in the animals treated with pentoxifylline, our findings suggest that pentoxifylline may reduce brain damage due to hypoxic-ischemic injury.


American Journal of Medical Genetics Part A | 2013

Possible autosomal recessive inheritance in an infant with acrofacial dysostosis similar to nager syndrome

Banu Güzel Nur; Francois P. Bernier; Osman Öztekin; Fırat Kardelen; Salih Kalay; Jillian S. Parboosingh; Ercan Mihci

The acrofacial dysostosis syndromes, which are characterized by malformations of the craniofacial region and limbs, are a clinically heterogeneous group of disorders. Based primarily on the of the pattern of limb defects two major groups have emerged: Nager syndrome with predominantly preaxial malformations plus mandibulofacial dysostosis (severe micrognathia and malar hypoplasia) and Miller syndrome with postaxial malformations plus mandibulofacial dysostosis. Among these syndromes, Nager syndrome is a rare condition but the most common form of acrofacial dysostosis. Most cases are sporadic, while autosomal dominant and autosomal recessive inheritance patterns have been reported. Recently, heterozygous mutations in the SF3B4 gene on chromosome 1q12–q21 were found to be responsible for a subset of sporadic and autosomal dominant cases. We present a female infant born to consanguineous parents with craniofacial features resembling Nager syndrome and a unilateral preaxial limb malformation. Mutation analysis of coding exons of SF3B4 did not identify any mutations. This couple also had a deceased child who had similar clinical features. We conclude that, the presence of consanguinity and absence of mutation in SF3B4, provides evidence in support of a recessive form of Nager syndrome.


Cardiology in The Young | 2010

The relationship between P-wave dispersion and diastolic functions in diabetic children.

Reşit Köken; Tevfik Demir; Tolga Altuğ Şen; Ahmet Afsin Kundak; Osman Öztekin; Faruk Alpay

OBJECTIVE The aim of this study was to investigate the relations between the P-wave dispersion and diastolic functions in type 1 diabetic children. PATIENTS A total of 33 diabetic patients without any cardiovascular disease, with a mean age of 12.3 plus or minus 4.2 years, and 29 healthy controls, with a mean age of 10.4 plus or minus 3.9 years were enrolled for this study. Left and right ventricular functions were assessed by using standard pulsed-wave Doppler echocardiography. P-wave dispersion was calculated by measuring minimum and maximum P-wave duration values on the surface electrocardiogram. RESULTS For the diabetic patients, P-wave maximum duration and dispersion was found to be significantly increased compared with healthy controls. Likewise, mitral A velocity and A velocity time integral was significantly increased while the isovolumic contraction time was significantly higher in the diabetics. In tricuspid valve measurements, however, A velocity time integral was found to be significantly higher, whereas the deceleration time was significantly lower in the diabetics. No relation was found between the left ventricle diastolic functions and duration of diabetes, HbA1c levels and P-wave dispersion in the diabetic children. No correlation was found between the diastolic functions and P-wave minimum, maximum duration, and dispersion for all the participants. CONCLUSION In type-1 diabetic children, the diastolic functions of both the ventricles were observed to be affected negatively together. Diabetes might be causing the prolongation of P-wave dispersion, but there was no relationship between the diastolic functions and P-wave dispersion in the diabetic children.


Experimental and Therapeutic Medicine | 2014

Role of immunoglobulin in neuronal apoptosis in a neonatal rat model of hypoxic ischemic brain injury

Salih Kalay; Osman Öztekin; Gönül Tezel; Hakan Aldemir; Emel Sahin; Sadi Köksoy; Mustafa Akcakus; Nihal Oygür

The objective of the present study was to evaluate the neuroprotective effects of immunoglobulin (Ig) in a neonatal hypoxic ischemic (HI) rat model. Seven-day-old rat pups were randomly assigned to control, hypoxia and hypoxia + Ig groups. The rats in the hypoxia +Ig group were intraperitoneally administered 1 g/kg Ig once, immediately after hypoxia. Saline was administered to the rats in the hypoxia group at the same time point. Eight rats from each of the Ig + hypoxia and hypoxia groups were sacrificed by decapitation 4 and 24 h following the administration of Ig or saline. The rats of the control group were sacrificed at the 4 h time-point. Caspase-3 activity, as well as IL-1β, IL-6 and TNF-α mRNA expression levels, were studied in the left ischemic hemispheres. Induction of cerebral ischemia increased the TNF-α, IL-6 and IL-1β mRNA expression levels significantly at 4 and 24 h in the left ischemic hemispheres in the hypoxia group compared with those in the control group. The systemic administration of Ig following HI encephalopathy significantly reduced the TNF-α, IL-6 and IL-1β mRNA expression levels in the ischemic tissue in the Ig + hypoxia group compared with those in the hypoxia group. In the hypoxia group, caspase-3 activity in the left half of the brain was found to be significantly increased compared with that in the control group. Caspase-3 activity in the Ig + hypoxia group was significantly lower than that in the hypoxia group. The observations of the present study indicate that Ig administration may be an efficient treatment approach for reducing cerebral apoptosis associated with hypoxic ischemia.


Journal of Maternal-fetal & Neonatal Medicine | 2013

The role of VEGF and its soluble receptor VEGFR-1 in preterm newborns of preeclamptic mothers with RDS

Salih Kalay; Burak Cakcak; Osman Öztekin; Gönül Tezel; Ozgur Tosun; Mustafa Akcakus; Nihal Oygür

Abstract Objective: We measured vascular endothelial growth factor (VEGF) and soluble VEGF receptor 1(sVEGFR-1) concentrations in cord blood and tracheal aspirate fluid (TAF) in order to investigate the role of them in lung maturation and the severity of respiratory distress syndrome (RDS) in preterm newborns, born to preeclamptic mothers. Methods: Newborns were divided into two groups as preterms born to preeclamptic mothers and preterms born to healthy mothers. They were also divided into two groups as severe RDS (sRDS) and mild RDS (mRDS) according to the need of surfactant and extent or type of ventilatory support. The concentrations of VEGF and sVEGFR-1 in cord blood and TAF (only in preterms with sRDS) were assayed by standardized enzyme-linked immunosorbent assay. Results: When the patients were evaluated as sRDS and mRDS, cord blood VEGF and VEGF/sVEGFR-1 concentrations of preterms with sRDS were significantly lower than the concentrations of preterms with mRDS. Conversely, cord blood sVEGFR-1 concentrations of preterms with sRDS were significantly higher than the concentrations of preterms with mRDS. VEGF and sVEGFR-1 concentrations in TAF could be compared only between sRDS preterms, born to preeclampsia (+) and (−) mothers. No statistical significance was detected between the two groups when sVEGFR-1, VEGF and VEGF/sVEGFR-1 concentrations in TAF were compared. Conclusion: Preeclampsia seems not to have an important effect on VEGF and sVEGFR-1 concentrations of preterm newborns both in cord blood and in TAF. Low VEGF and high sVEGFR-1 concentrations seem to be associated with the severity of RDS irrespective of preeclampsia, suggesting that VEGF may be one of the main components of lung maturation.


American Journal of Perinatology | 2014

Levels of ischemia-modified albumin in transient tachypnea of the newborn.

Osman Öztekin; Salih Kalay; Cüneyt Tayman; Huseyin Tugrul Celik

AIM The aim of the article is to evaluate ischemia-modified albumin (IMA) levels in infants with transient tachypnea of the newborn (TTN) and to find out its relation to the disease severity. Patients and METHODS Infants with > 37 weeks of gestation, without any respiratory and cardiac symptoms and without any maternal health problems, and diagnosed as TTN were allocated as the study group. Patients with obvious retractions, grunting, hypercarbia (Pco 2 > 60 mm Hg) or hypoxia (oxygen saturation < 88% with Fio 2 of 0.60) were managed with nasal continuous positive airway pressure (CPAP). During the postnatal 0 to 24 hours, blood samples were collected in 2 mL for IMA. RESULTS A total of 47 patients were diagnosed TTN, and allocated as the study group. Of the 47 patients, 43 patients without respiratory symptoms were enrolled as the control group. IMA levels in TTN were found to be significantly higher (p < 0.05). In addition, IMA levels were significantly increased in the nasal CPAP group versus supplemental oxygen therapy groups (p < 0.05). IMA levels were determined to be significantly higher in the > 3 days of oxygen therapy group (p < 0.05). IMA levels with a cutoff point of 0.87 ABSU, sensitivity of 81.1% and specificity of 69.8% predicted TTN (area under the curve [AUC] = 0.85; p < 0.05). IMA levels with > 0.98 ABSU, 78% sensitivity, and 86% specificity indicated the prediction of CPAP requirement (AUC = 0.86; p < 0.05). CONCLUSION IMA levels were significantly higher in infants with diagnosed TTN. Therefore, IMA may be used as a new marker for predicting TTN and disease severity.


Journal of Maternal-fetal & Neonatal Medicine | 2014

Is the strength of direct antiglobulin test important for the duration of phototherapy

Osman Öztekin; Salih Kalay; Gönül Tezel; Ebru Barsal; Selen Bozkurt; Mustafa Akcakus; Nihal Oygür

Abstract The purpose of this study was to evaluate the relationship between the grades of positivity of the direct antiglobulin test (DAT) and their effects on the duration of phototherapy for neonatal jaundice. DAT reactions of blood samples were graded as (1+), (2+), (3+) and (4+). DAT was positive in 80 neonates who were exposed to phototherapy due to jaundice. Patients with positive DAT reactions are classified in the study as follows: 34 newborns were DAT (1+), 18 newborns were DAT (2+), 16 newborns were DAT (3+) and 12 newborns were DAT (4+). We found that higher grades of positivity of DAT are associated with extended duration of phototherapy (r = 0.436, p < 0.05). Additionally, DAT (4+) reactions are more predictive for a prolonged duration of phototherapy requirement than the other grades (p < 0.0001).


Turk Pediatri Arsivi-turkish Archives of Pediatrics | 2013

Yenidoğanın geçici takipnesinde epiteliyal sodyum kanalı alfa alt biriminin sentezinden sorumlu SCNN1A geninin değerlendirilmesi

Osman Öztekin; Mahmut Akyol; Salih Kalay; Gönül Tezel; Mustafa Akcakus; Nihal Oygür

Sum mary Aim: Epithelial sodium channels play an important role in the regulation of movement of sodium and absorption of alveolar fluid during prenatal period. Transient tacyhpnea of the newborn is a common respiratory problem in term or near-term infants. A lack of maturation of epithelial sodium channels is considered in its etiology. However, the role of genetic factors is unclear. The purpose of this study is to determine the role of gene SCNN1A which is responsible for synthesis of epithelial sodium channel alpha unit which is known to be effective in the mechanism of the disorder. Material and Method: Newborn infants>37 weeks of gestation with a diagnosis of transient tacyhpnea of the newborn followed up at Neonatal Intensive Care Unit of Akdeniz University Medical Faculty between July 2010 January 2012 and a control group consisting of healthy infants at the same gestational age were included in the study. 2 cc of blood with EDTA was obtained from both groups in the first five days of their life and blood samples were kept at -80 ̊ degree. DNA isolation was fulfilled in the Department of Medical Biology. The gene was displayed using BigDye Terminator with the method of Sanger sequencing. The study was approved by the ethics commite (B.30.2.AKD.0.20.05.05). Results: Both the transient tacyhpnea of the newborn group and the control group were consisted of 32 infants. Through the sequence display method, all the exons of the SCNN1A gene which codes the alpha subunit of epithelial sodium channels were displayed. Nevertheless, no significant change was found. Conclusions: In conclusion, no relationship was established between the development of transient tacyhpnea of the newborn and the SCNN1A gene which is responsible for the synthesis of alpha subunit of epithelial sodium channels. However, this preliminary study is considered to be a threshold for an extended research with a wider range of patients to obtain more precise results. (Turk Arch Ped 2013; 48: 35-39)

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Reşit Köken

Afyon Kocatepe University

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Tulay Koken

Afyon Kocatepe University

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