Network


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

Hotspot


Dive into the research topics where Zekai Avci is active.

Publication


Featured researches published by Zekai Avci.


Blood | 2008

Genotype-phenotype correlation in combined deficiency of factor V and factor VIII

Bin Zhang; Marta Spreafico; Chunlei Zheng; Angela Yang; Petra Platzer; Michael U. Callaghan; Zekai Avci; Namik Ozbek; Johnny Mahlangu; Tabitha Haw; Randal J. Kaufman; Kandice Marchant; Edward G. D. Tuddenham; Uri Seligsohn; Flora Peyvandi; David Ginsburg

Combined deficiency of factor V and factor VIII (F5F8D) is caused by mutations in one of 2 genes, either LMAN1 or MCFD2. Here we report the identification of mutations for 11 additional F5F8D families, including 4 novel mutations, 2 in MCFD2 and 2 in LMAN1. We show that a novel MCFD2 missense mutation identified here (D81Y) and 2 previously reported mutations (D89A and D122V) abolish MCFD2 binding to LMAN1. Measurement of platelet factor V (FV) levels in 7 F5F8D patients (4 with LMAN1 and 3 with MCFD2 mutations) demonstrated similar reductions to those observed for plasma FV. Combining the current data together with all previous published reports, we performed a genotype-phenotype analysis comparing patients with MCFD2 mutations with those with LMAN1 mutations. A previously unappreciated difference is observed between these 2 classes of patients in the distribution of plasma levels for FV and factor VIII (FVIII). Although there is considerable overlap, the mean levels of plasma FV and FVIII in patients with MCFD2 mutations are significantly lower than the corresponding levels in patients with LMAN1 mutations. No differences in distribution of factor levels are observed by sex. These data suggest that MCFD2 may play a primary role in the export of FV and FVIII from the ER, with the impact of LMAN1 mediated indirectly through its interaction with MCFD2.


Scandinavian Journal of Infectious Diseases | 2005

Childhood diarrhoea in Ankara, Turkey: Epidemiological and clinical features of rotavirus-positive versus rotavirus-negative cases

Ahmet Karadag; Ziya Cibali Acikgoz; Zekai Avci; Ferhat Catal; Safiye Gocer; Sohret Gamberzade; Nurdan Uras

Published reports dealing with rotavirus infections in Turkey are very scarce. This study included 1099 consecutive paediatric patients with diarrhoea, who sought care at 3 hospitals in Ankara, Turkey between 1999 and 2002 and were investigated for the presence of rotavirus antigen in faeces. Rotavirus antigen was detected by an immunochromatographic test, Simple Rotavirus (Operon, Spain). Other clinical and laboratory data were extracted from patient journals. A total of 404 (36.8%) patients were positive for rotavirus antigen. Rotavirus antigen was more frequently detected in boys than girls (40.8 vs 31.8%) and in children younger than 2 y (62.7%). The proportion of rotavirus-positive children was higher in the winter season (49.6%; November to April) and the highest proportion was observed in December (55.4%). Rotavirus-associated diarrhoea had a more severe clinical presentation than non-rotaviral diarrhoea; 55.3% of all patients who required hospitalization were rotavirus-positive. The seasonal and epidemiological characteristics of rotavirus diarrhoea in Ankara were similar to those in the USA and Europe. For reliable nationwide information about the epidemiology of rotavirus-associated disease in Turkey, more individual studies and reliable official statistics of gastroenteritis cases are needed.


Pediatric Cardiology | 2008

Successful Use of Recombinant Factor VIIa (NovoSeven®) During Cardiac Surgery in a Pediatric Patient with Congenital Factor XI Deficiency

Zekai Avci; Baris Malbora; Mahmut Gökdemir; Suleyman Ozkan; Namik Ozbek

We report our experience with the use of recombinant activated factor VII (rFVIIa) during cardiac surgery in a 4.5-year-old boy with severe congenital FXI deficiency and a congenital heart disease. After weaning the patient from cardiopulmonary bypass, the first intravenous dose of rFVIIa (90 μg/kg) was administered. This same dosage was repeated eight more times, at 2- to 4-hour intervals postoperatively. There was no bleeding during and after surgery. rFVIIa treatment may be used successfully in children with severe FXI deficiency in major operations such as open heart surgery.


Blood Coagulation & Fibrinolysis | 2008

Thrombosis in children with cardiac pathology : analysis of acquired and inherited risk factors

Bulent Alioglu; Zekai Avci; Kürşat Tokel; F. Belgin Ataç; Namik Ozbek

The present study was conducted to analyze the features and risk factors of childhood thrombotic events in patients with cardiac defect followed-up at our hospital. The clinical and laboratory findings of 59 patients diagnosed with cardiac defects and thromboses between 1997 and 2006 were retrospectively analyzed. Thirty-one children (52.5%) had venous system thromboses, 21 (35.6%) had arterial system thromboses, and seven (11.9%) had venous and arterial system thromboses. Presence of congenital heart disease and cardiomyopathy (CMP) were significant risk factors for developing intracardiac thrombosis. In addition, presence of congenital heart disease was the significant statistical risk factor for developing left atrium and right ventricle thromboses. Presence of congenital heart disease was a significant risk factor for developing a central nervous system thrombosis. Presence of pulmonary stenosis and aortic coarctation were significant risk factors for developing a peripheral arterial system thrombosis. Acquired risk factors including major surgery, angiography, central venous catheter, systemic infection, and hypoxia were identified in 49 of the 59 patients. Many patients had more than one of these acquired risk factors. Analysis of the relationship between thrombosis and type of major surgery demonstrated a statistically significant relationship between an intracardiac thrombosis and total correction of tetralogy of Fallot and a peripheral venous system thrombosis and a Blalock Taussig shunt. Twenty-three of the 52 patients (44.2%) had at least one thrombophilic mutation. Overall, a heterozygous factor V Leiden mutation was found in nine patients (17.3%), a methylenetetrahydrofolate reductase 677C-T mutation in 15 patients (28.8%), and a PT 20210G-A mutation in three patients (5.8%). Our data suggest that cardiac defects are common risk factors for developing a childhood thrombosis. The type of disorder determines the site of thrombosis. Acquired risk factors may contribute to the development of a thrombosis. The results of this study also indicate that to ensure early diagnosis, routine screening for thrombosis should be performed in patients with a cardiac defect and that screening for factor V Leiden and PT 20210G-A mutations and other genetic risk factors should be included when assessing all patients with cardiac defects who present with a thrombosis, whether or not a predisposing factor has been identified.


International Journal of Hematology | 2007

Neutropenic Enterocolitis in Children with Acute Leukemia or Aplastic Anemia

Bulent Alioglu; Zekai Avci; Figen Ozcay; Serdar Arda; Namik Ozbek

Neutropenic enterocolitis (NE) and acute appendicitis are life-threatening conditions that develop in children with severe or prolonged neutropenia secondary to acute leukemia and lymphoma. The medical records of 118 patients who were treated for acute lymphoblastic leukemia (69 patients), acute myelogenous leukemia (22 patients), or aplastic anemia (27 patients) between 1997 and 2006 in our hospital pediatric hematology department were examined retrospectively. NE was diagnosed in 11 patients (age range, 2.5–16 years) on the basis of clinical and laboratory features. Two of these 11 patients had appendicitis in addition to NE. Conservative treatment was favored for all patients, but 1 patient with acute appendicitis underwent surgery. Neutropenic patients with a hematologic malignancy and abdominal pain should receive their diagnoses immediately and undergo treatment. NE and acute appendicitis should always be considered in the differential diagnosis of abdominal pain. Conservative treatment must be choseninitially for patients with NE, and these patients should be evaluated carefully for surgery. The criteria for the surgical process are the same as those for immunocompetent children. In addition, the close monitoring of hematologic factors is necessary.


Pediatric Hematology and Oncology | 2009

Incidence of and risk factors for childhood thrombosis: a single-center experience in Ankara, Turkey.

Namik Ozbek; Bulent Alioglu; Zekai Avci; Baris Malbora; Özge Sürmeli Onay; Emel Ozyurek; Fatma Belgin Atac

This study was conducted to analyze the incidence of and risk for thrombosis in thrombotic children monitored in the Department of Pediatric Hematology of our hospital at the time of diagnosis, in addition to the clinical characteristics of those patients. The clinical and laboratory findings of 122 patients diagnosed with thrombosis from 1997 to 2006 were retrospectively analyzed. The incidence of thrombosis was 88.6/10,000 hospital admissions. The authors found that 31.1% of the patients studied had a thrombosis in more than 1 region. The incidence of thrombosis by anatomic site was as follows: 42 thromboses in the peripheral arterial system, 39 in an intracardiac region, 38 in the abdominal venous system, 36 in the deep peripheral venous system, and 28 in the cerebral vascular system. The mean age of the patients at the time of diagnosis was 4.9 years. Of the patients studied, 10.7% were neonates, 35.3% were infants younger than 1 year, and 48.4% were younger than 2 years. Most of the patients had a congenital cardiac disease and spontaneous thrombosis, and 66.1% had at least 1 acquired risk factor, the most common of which were having undergone surgery (42%) or wearing a central venous catheter (39%). A hereditary factor for the development of thrombosis was present in 54% of the patients. The most frequently observed hereditary risk factor was the MTHFR 677C-T mutation, and the second most common was the factor V Leiden mutation. Thrombosis should be considered a systemic disorder, and thrombotic patients should be evaluated with appropriate methods. Acquired and hereditary risk factors should be analyzed systematically in thrombotic patients.


European Journal of Pediatrics | 2008

Etiology of hemolysis in two patients with hepatitis A infection: glucose-6-phosphate dehydrogenase deficiency or autoimmune hemolytic anemia

Ferda Ozbay Hosnut; Figen Ozcay; Umut Selda Bayrakci; Zekai Avci; Namik Ozbek

We report two children with hemolytic anemia during the course of hepatitis A infection. On admission, the patients had high blood urea nitrogen, creatinine, and uric acid levels, as well as anemia, leucocytosis, and direct and indirect hyperbilirubinemia. Both patients had a glucose-6-phosphate dehydrogenase deficiency (G6PD) and autoimmune antibodies. They were given vitamin K on admission. Inadvertent administration of vitamin K could have been related to an acute reduction in hemoglobin concentration. To prevent renal damage, plasmapheresis with fresh frozen plasma was done to clear bilirubin and plasma hemoglobin. The hyperbilirubinemia responded to plasmapheresis. However, acute tubular necrosis complicated the clinical course in one patient, and several sessions of hemodialysis were required. In conclusion, intravascular hemolysis should be considered in patients with hepatitis A infection, marked hyperbilirubinemia, and anemia. Although hepatitis A vaccination is not yet recommended for routine administration, high-risk patients, including those with a G6PD deficiency, should be vaccinated against hepatitis A.


Pediatric Hematology and Oncology | 2007

INVASIVE ESOPHAGEAL ASPERGILLOSIS ASSOCIATED WITH ACUTE MYELOGENOUS LEUKEMIA: Successful Therapy with Combination Caspofungin and Liposomal Amphotericin B

Bulent Alioglu; Zekai Avci; Oguz Canan; Figen Ozcay; Beyhan Demirhan; Namik Ozbek

Aspergillosis is one of the most common invasive fungal infections in patients with leukemia. In this patient group, this form of Aspergillus infection is a life-threatening condition with a mortality of 50–100%. The lungs are most often affected, but the esophagus can also be involved.The authors report the case of a child with leukemia who developed invasive esophageal aspergillosis. The condition was diagnosed by microscopic examination of endoscopic biopsy specimens. The patient was already receiving empirical liposomal amphotericin B when the diagnosis was made, so a second antifungal (caspofungin) was added to the regimen. This combination was successful. This case to demonstrates a case of successful treatment of invasive esophageal aspergillosis using combination therapy of liposomal amphotericin B and caspofungin.


Urology | 2008

Ultrasound and Computed Tomography Findings of Spontaneous Intramural Hemorrhage of Renal Pelvis and Ureter in Patient With Hemophilia A

Ismail Kirbas; Esra Ozgul; Zekai Avci; Mehmet Coskun; Namik Ozbek

Intramural renal pelvic and ureteral hemorrhage is seen most commonly in patients treated with anticoagulant therapy. However, spontaneous intramural hemorrhage of the ureter seen in patients with hemophilia is a rare entity and has been reported only in 2 cases. Computed tomography is a valuable imaging method in the diagnosis and follow-up. We report the ultrasound and computed tomography findings of spontaneous intramural renal pelvic and ureteral hemorrhage in a patient with hemophilia A.


Pediatric Allergy and Immunology | 2004

Is hypertonic saline better than normal saline for allergic rhinitis in children

Ahmet Karadag; Zekai Avci; Hanifi Kurtaran; Ferhat Çatal

Editor, We have taken an interest in a recently published article in your journal by Garavello et al. (1). The authors reported that nasal hypertonic saline irrigation in symptomatic allergic rhinitis has reduced the mean daily score of allergic rhinitis. However, the use of nasal hyperosmolar saline administration is known to have some adverse effects. Hyperosmolar challenge leads to histamine release and can be used as a simple diagnostic test for allergic rhinitis and may provide a model for nasal hyper-reactivity (2). In the same study saline does not make these symptoms as hyperosmolar challenge (2). Nasal hypersaline provacation leads to substance P release and glandular secretion by means of stimulation of nociceptive nerves, so that there can be pain in patients (3). Garavello et al. have not determined their patients’ nasal pain in their study. It is necessary to take care about this adverse effect for the patients administered nasal hypertonic saline. Moreover, it is well known that hypertonic saline decreases ciliary movement in human nasal epithelium in vitro (4). We would like to bring to the attention that nasal saline washing has been used effectively in the treatment of some respiratory tract infections (5–7). Saline nose drops facilitate nasal drainage without affecting ciliary activity. In nasal irrigation the normal saline does not cause the adverse effects seen in hypertonic saline use since it is physiologic. Overall, we do believe that the controlled trials comparing the effectivenesses and the adverse effects of the normal saline and hypertonic saline use in allergic rhinitis will determine whether the hypertonic or the normal saline is superior.

Collaboration


Dive into the Zekai Avci's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Bahattin Tunç

Boston Children's Hospital

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Nese Yarali

Boston Children's Hospital

View shared research outputs
Researchain Logo
Decentralizing Knowledge