Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Davut Albayrak is active.

Publication


Featured researches published by Davut Albayrak.


The Journal of Pediatrics | 1994

Acute immune thrombocytopenic purpura: A comparative study of very high oral doses of methylprednisolone and intravenously administered immune globulin☆☆☆★

Davut Albayrak; Ismail Islek; Ayhan Gazi Kalayci; Nuran Gürses

We compared very high doses of methylprednisolone with intravenously administered immune globulin for treatment of acute idiopathic thrombocytopenic purpura. Fifty-seven children were randomly assigned to receive the immune globulin preparation, 0.5 gm/kg per day for 5 consecutive days (n = 19), orally administered methylprednisolone, 30 mg/kg per day for 7 days (n = 19), or orally administered methylprednisolone, 50 mg/kg per day for 7 days (n = 19). There were no differences in the response of the platelet counts among the groups. We conclude that these two therapies were equally effective; choice between them may be made according to cost and therapy-related risks.


Journal of Bone and Mineral Research | 2013

SNX10 mutations define a subgroup of human autosomal recessive osteopetrosis with variable clinical severity.

Alessandra Pangrazio; Anders Fasth; Andrea Sbardellati; Paul J. Orchard; Kimberly A. Kasow; Jamal Raza; Canan Albayrak; Davut Albayrak; Olivier Vanakker; Barbara De Moerloose; Ashok Vellodi; Luigi D. Notarangelo; Claire Schlack; Gabriele Strauss; Jörn Sven Kühl; Elena Caldana; Nadia Lo Iacono; Lucia Susani; Uwe Kornak; Ansgar Schulz; Paolo Vezzoni; Anna Villa; Cristina Sobacchi

Human Autosomal Recessive Osteopetrosis (ARO) is a genetically heterogeneous disorder caused by reduced bone resorption by osteoclasts. In 2000, we found that mutations in the TCIRG1 gene encoding for a subunit of the proton pump (V‐ATPase) are responsible for more than one‐half of ARO cases. Since then, five additional genes have been demonstrated to be involved in the pathogenesis of the disease, leaving approximately 25% of cases that could not be associated with a genotype. Very recently, a mutation in the sorting nexin 10 (SNX10) gene, whose product is suggested to interact with the proton pump, has been found in 3 consanguineous families of Palestinian origin, thus adding a new candidate gene in patients not previously classified. Here we report the identification of 9 novel mutations in this gene in 14 ARO patients from 12 unrelated families of different geographic origin. Interestingly, we define the molecular defect in three cases of “Västerbottenian osteopetrosis,” named for the Swedish Province where a higher incidence of the disease has been reported. In our cohort of more than 310 patients from all over the world, SNX10‐dependent ARO constitutes 4% of the cases, with a frequency comparable to the receptor activator of NF‐κB ligand (RANKL), receptor activator of NF‐κB (RANK) and osteopetrosis‐associated transmembrane protein 1 (OSTM1)‐dependent subsets. Although the clinical presentation is relatively variable in severity, bone seems to be the only affected tissue and the defect can be almost completely rescued by hematopoietic stem cell transplantation (HSCT). These results confirm the involvement of the SNX10 gene in human ARO and identify a new subset with a relatively favorable prognosis as compared to TCIRG1‐dependent cases. Further analyses will help to better understand the role of SNX10 in osteoclast physiology and verify whether this protein might be considered a new target for selective antiresorptive therapies.


Acta Paediatrica | 2005

The prevalence of coeliac disease as detected by screening in children with iron deficiency anaemia

Ayhan Gazi Kalayci; Yilmaz Kanber; Asuman Birinci; Levent Yildiz; Davut Albayrak

AIM Iron deficiency anaemia is a frequent finding seen in coeliac disease, which can be diagnosed alone or with other findings. In this study, our aim was to determine the prevalence of coeliac disease in children with iron deficiency anaemia without significant gastrointestinal symptoms. METHODS There were 135 children with iron deficiency anaemia in the patient group (group 1), and 223 healthy children without iron deficiency anaemia in the control group (group 2) in this study. Antiendomysial antibody (EMA) IgA test was given to both groups. Antiendomysial antibody-positive patients underwent small intestine biopsy. RESULTS The mean age was 7.2+/-4.6 (2-16) y in the patient group (group 1) and 8.2+/-3.8 (2-16) y in the control group (group 2), and no significant difference between the two groups was detected. In terms of gender, there was a significant difference between groups 1 and 2 (M/F: 74/61 and 98/125, respectively) ( p<0.05). EMA was positive in six cases in group 1 (4.4%), and villous atrophy and/or inflammation in the lamina propria with increased intraepithelial lymphocytes was seen on small intestine biopsy in these patients. In the control group, EMA was negative in all children. In detailed histories of patients with coeliac disease diagnosis, recurrent iron deficiency anaemia/pica was found in four patients (66.7%) and occasionally foul-smelling or watery stool attacks were seen in four patients (66.7%). Three of these six patients (50%) had short stature. CONCLUSION The prevalence of coeliac disease was high in patients with iron deficiency anaemia; therefore, gastrointestinal findings should be further examined for coeliac disease, and the possibility of coeliac disease should be investigated in patients with recurrent iron deficiency anaemia and short stature.


Acta Odontologica Scandinavica | 2006

Comparison of platelet pellet and bioactive glass in periodontal regenerative therapy

Gonca Cayir Keles; Burcu Ozkan Cetinkaya; Davut Albayrak; Hülya Köprülü; Gökhan Açikgöz

Objective. In recent years, platelet-rich plasma combined with graft materials has been used for periodontal regeneration. The individual role of blood products with guided tissue regeneration in periodontal regenerative therapy is unclear and needs to be elucidated. The purpose of this study was to compare the clinical and radiological effectiveness of platelet pellet/guided tissue regeneration (PP/GTR) and bioactive glass/GTR (BG/GTR) treatments in patients with periodontal disease. Material and methods. Using a split mouth design, 15 chronic periodontitis patients with pocket depths ≥ 6 mm following periodontal initial therapy were randomly assigned to treatment with a combination of PP/GTR or BG/GTR in contralateral dentition areas. An absorbable membrane of polylactic acid was used GTR. The criteria for the comparative study were preoperative and postoperative 6 months pocket depth, clinical attachment level, and radiological alveolar bone level. Results. Both treatment modalities resulted in significant pocket depth reduction and gain in clinical attachment and alveolar bone level compared to the preoperative values (p<0.01). Reduction in pocket depth, gain in clinical attachment and alveolar bone level were 4(3–6), 4.1±0.7, 4.9±1.4 mm in the PP/GTR group and 4(3–7), 4.1±1.2, 5.9±1.7 mm in the BG/GTR group, respectively. The differences between the two groups were not statistically significant (p>0.05). Conclusions. Within the limits of this study, it was concluded that PP may be effective as a bioactive glass graft material and used as a graft material for treating intrabony defects. PP thus appears to be a suitable alternative in the regenerative treatment of intrabony periodontal defects.


Acta Paediatrica | 2007

Visceral childhood leishmaniasis in Turkey

Mehmet Totan; Ayhan Dagdemir; Ali Muslu; Davut Albayrak

Between 1981 and 2001, we retrospectively analysed 40 cases of visceral leishmaniasis (VL) admitted to the Paediatric Infection Unit of Ondokuz Mayis University Hospital, in the middle Black Sea region of Turkey. Median age at presentation was 3 y. Fever and splenomegaly were found in all patients. Bone marrow smear examination resulted in the diagnosis of VL in 95% of cases. All patients were treated initially with meglumine antimonate and 95% of them were cured with this therapy. The remaining patients were cured with liposomal amphotericin B.


Thrombosis Research | 2014

Bleeding and non-bleeding phenotypes in patients with GGCX gene mutations.

Matthias Watzka; Christof Geisen; Monika Scheer; Regina Wieland; Verena Wiegering; Thomas Dörner; Hans-Jürgen Laws; Fatma Gumruk; Sahin Hanalioglu; Sule Unal; Davut Albayrak; Johannes Oldenburg

Functional limitations for the vitamin K cycle, caused either by mutations in gamma-glutamyl carboxylase or vitamin K epoxide reductase genes, result in hereditary deficiency of vitamin K-dependent coagulation factors (VKCFD1 and VKCFD2, respectively). Patients suffering from VKCFD often share several other anatomical irregularities which are not related to haemostasis. Here we report on nine patients, eight of them previously unreported, who presented with VKCFD1. All were examined with special attention to vitamin K-dependent coagulation factors as well as to bone and heart development and to other anatomical signs of embryonal vitamin K deficiency. In total, we detected ten mutations in the gamma-glutamyl carboxylase gene of which seven have not been previously reported. Most interestingly, additional non-bleeding phenotypes were observed in all patients including midfacial hypoplasia, premature osteoporosis, cochlear hearing loss, heart valve defects, pulmonary stenosis, or pseudoxanthoma elasticum-like phenotype. Undercarboxylated matrix Gla protein, osteocalcin, and periostin appear to be responsible for these defects which are also observed in cases of fetal warfarin syndrome.


Journal of Pediatric Hematology Oncology | 2015

Invasive fungal infections in children with hematologic and malignant diseases.

Sevinc Nursev Ozsevik; Gulnar Sensoy; Arzu Karli; Canan Albayrak; Ayhan Dagdemir; Nursen Belet; Murat Elli; Tunc Fisgin; Emel Özyürek; Feride Duru; Davut Albayrak

Background: To evaluate the clinical feature and outcome of invasive fungal infections (IFI) in children with hematologic and malign diseases. Patients and Methods: The medical records of children with hematologic and malignant diseases, who were hospitalized at our hospital between January 2010 and December 2011, were reviewed. Proven, probable, and possible IFIs were diagnosed according to the revised definitions of the European Organization for Research and Treatment of Cancer/Mycosis Study Group. The demographic, clinical, and laboratory characteristics of the patients who met the study criteria were evaluated. Results: IFI was diagnosed in 67 (7.2%) febrile episodes of 56 patients, of which 10 (1.2%) were proven, 20 (2%) probable, and 37 (4%) possible IFI. Blood culture of 10 cases with proven IFI yielded yeast and the most common isolated agent was Candida parapsilosis. Seventy percent of cases with fungemia had central venous catheter (CVC). Twenty cases with probable IFI had invasive mold infection. The cases with mold infection had higher median C-reactive protein values, lower neutrophil counts, and longer duration of neutropenia compared with the cases with yeast infection. A total of 14 patients (20.9%) died. Presence of CVC, bone marrow transplantation, total parenteral nutrition, prolonged fever, and proven/probable IFI were detected more often in patients who died, compared with patients who survived. Conclusions: IFIs are important causes of death in children with hematologic and malignant diseases. Mold infections are seen more frequently in cases with prolonged and profound neutropenia, and invasive yeast infections, especially with non-albicans Candida species, in cases with CVC. Early and effective treatment considering these findings will help to decrease the mortality.


Scandinavian Journal of Infectious Diseases | 2002

Randomized, Double-blinded, Placebo-controlled Trial of Early Administration of Recombinant Human Granulocyte Colony-stimulating Factor to Non-neutropenic Preterm Newborns Between 33 and 36 Weeks with Presumed Sepsis

Sukru Kucukoduk; Taner Sezer; Alisan Yildiran; Davut Albayrak

A randomized, double-blinded, placebo-controlled trial was conducted of early administration of recombinant granulocyte colony-stimulating factor (rGCSF) to 40 non-neutropenic, preterm infants between 33 and 36 weeks of gestational age with the diagnosis of presumed sepsis. The treatment group (n = 20) received 5 μg/kg per day of intravenous rGCSF once daily for 3 d and the control group (n = 20) received the same volume of physiological serum. Immediately before the first dose and on the 4th day, plasma levels of GCSF and tumour necrosis factor-α (TNF-α), absolute neutrophil counts (ANC), immature neutrophil count (INC), immature/total neutrophil (I/T) ratios and platelet counts were determined. At study entry, the plasma GCSF and TNF-α levels were similar. On day 4, there was no significant change in GCSF levels in either groups, whereas there was a significant decrease in TNF-α levels in the treatment group. ANC and INC of the treatment group also increased significantly. The I/T ratio continued at the same level in the treatment group, but decreased significantly on days 4 and 7 day in the control group. The length of time on the neonatal intensive care unit (NICU) was significantly shorter in the treatment group. In conclusion, early administration of 3 daily doses of rGCSF (5 μg/kg per day) to non-neutropenic, preterm infants who had presumed sepsis increased circulating ANC and INC, decreased plasma TNF-α levels and shortened the length of time on the NICU.


Acta Paediatrica | 2007

Intracranial haemorrhage due to factor V deficiency

Mehmet Totan; Davut Albayrak

Factor V deficiency is a rare coagulation disorder which is inherited autosomal recessively. Factor V deficiency should be considered in infants with bleeding disorders and prolonged prothrombin and activated partial thromboplastin times if bleeding continues in spite of vitamin K injection. In this article, the case of an infant with an intracranial haemorrhage due to congenital factor V deficiency is reported.


Pediatric Hematology and Oncology | 2005

ORAL AND DENTAL FINDINGS IN FANCONI'S ANEMIA

Aydan Açikgöz; Feyza Otan Özden; Tunc Fisgin; Gökhan Açikgöz; Feride Duru; Nese Yarali; Davut Albayrak

Fanconis anemia is an autosomal recessive disorder characterized by progressive pancytopenia and congenital malformation of the skeleton. This study investigated the oral health status of 15 children with Fanconis anemia, including oral lesions, gingival and periodontal status, and dental abnormalities. All children in the group were found to have a tendency to develop tooth decay and were in need of dental treatment. Two had aggressive periodontitis. In one patient supernumerary teeth were found, while in another teeth were congenitally missing. The increased tendency toward periodontal disease in patients with Fanconis anemia may be due not only to the anemia, leukopenia, and defective detoxification of oxygen radicals that are characteristic of the disease itself, but also to medications applied during intense immunosuppressive treatment, such as prednisolone.

Collaboration


Dive into the Davut Albayrak's collaboration.

Top Co-Authors

Avatar

Canan Albayrak

Ondokuz Mayıs University

View shared research outputs
Top Co-Authors

Avatar

Tunc Fisgin

Ondokuz Mayıs University

View shared research outputs
Top Co-Authors

Avatar

Ayhan Dagdemir

Ondokuz Mayıs University

View shared research outputs
Top Co-Authors

Avatar

Mehmet Totan

Ondokuz Mayıs University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Feride Duru

Boston Children's Hospital

View shared research outputs
Top Co-Authors

Avatar

Cengiz Dilber

Ondokuz Mayıs University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Nuran Gürses

Ondokuz Mayıs University

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge