Mehmet Tas - Academia.edu (original) (raw)

Papers by Mehmet Tas

Vaccine, Jan 29, 2015

Varicella in previously immunized individuals, known as "breakthrough varicella". While... more Varicella in previously immunized individuals, known as "breakthrough varicella". While the majority of breakthrough cases are mild, some may be severe, requiring hospitalization in previously healthy children or children with an underlying condition. This report, as a part of the prospective national pediatric varicella hospitalizations study (including 29 centers, represent 50% of pediatric population) in Turkey, is aimed to evaluate breakthrough varicella infection requiring hospitalization before the routine use of single-dose live varicella vaccine in national program from 2008 to 2013 (<10% of the pediatric age group received a single-dose vaccine). In the time period, 1939 children were hospitalized due to varicella infection in Turkey; 36 children (20 boys, 16 girls, mean age 68.0+37.6 months, all received single dose live varicella vaccine) with breakthrough varicella infection. Breakthrough varicella infection might be severe in previously healthy children (61...

Case Reports in Medicine, 2013

Background. Extrarenal pathologies may be associated with renal position and fusion anomalies. Ac... more Background. Extrarenal pathologies may be associated with renal position and fusion anomalies. According to the literature, our patient is the first horseshoe kidney case that had mega cisterna magna, arachnodactyly, and mild mental retardation. Case Report. A 9-year-old boy admitted because of the myoclonic jerks. He had a dysmorphic face, low-set and cup-shaped ears, arachnodactyly, and mild mental retardation. The patient's laboratory findings were normal except for a mild leucocytosis and hypochromic microcytic anemia. His cerebrospinal fluid was cytologically and biochemically normal. Cranial MRI revealed 1.5 cm diametered mega cisterna magna in the retrocerebellar region. Although there were no significant epileptical discharges in the electroencephalography, there were slow wave discharges arising from the anterior regions of both hemispheres. Because he had stomachache, abdominal ultrasonography was performed, and horseshoe kidney was determined. Abdominal CT did not reveal any abnormalities except the horseshoe kidney. There were not any cardiac pathologies in echocardiography. He had normal 46XY karyotype and there were no repeated chromosomal derangements, but we could not evaluate for molecular and submicroscopic somatic changes. He was treated with valproic acid and myoclonic jerks did not repeat. Conclusion. We suggest that the presence of these novel findings may represent a newly recognized, separate syndrome.

Pediatrics International, 1990

Serum levels of total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol ... more Serum levels of total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and fructosamine (FA) were determined in thirty -three children with malignant diseases and twenty healthy controls aged 1-14 years. Of them, FA was the parameter measured in children with malignancy for the first time. Mean serum TC, HDL-C, LDL-C and FA showed statistically significant decreases in malignancy compared to healthy children, whereas a statistically significant increase was observed for TG concentrations in serum. From these data, we conclude that significant relations between serum lipids and lipoproteins and the state of malignancy exist in the children studied, and it should be remembered that serum FA concentrations are affected by abnormal serum protein turnover when one deals with any type of neoplastic disease.

Indian Journal of Hematology and Blood Transfusion, 2014

To determine the clinical and hematologic features of 68 children with hereditary spherocytosis (... more To determine the clinical and hematologic features of 68 children with hereditary spherocytosis (HS). In this retrospective study, we analyzed recorded information of 68 HS patients diagnosed between March 1997 and March 2007, including clinical manifestations at admission, gender, median age at diagnosis, family history, hematologic and biochemical data, patient management, complications, median age of splenectomy, and median follow-up time. Sixty-eight patients with HS (36 male and female) were investigated. The median age at diagnosis was 5.6 years (range 3 months to 18 years). Twenty-seven (39.7 %) had parents with consanguineous marriages, and 20 (29.4 %) had parents with first-degree consanguinity. Predominant clinical manifestations at admission were anemia in 59 patients (86.76 %), splenomegaly in 49 (72.05 %), and jaundice in 33 (48.52 %). Patients were classified as mild, moderate, or severe in 29.4, 61.7, and 8.8 % of patients, respectively. Five patients (7.3 %) underwent splenectomy. Major complications of HS were hemolytic, aplastic, and megaloblastic crises and cholelithiasis in 7 (10.2 %), 1 (1.4 %), 7 (10.2 %), and 6 (8.8 %) of patients, respectively. There were no deaths during follow-up. HS should be considered in evaluating possible diagnoses in patients with hemolytic anemia. In this study, the clinical course of patients with HS was relatively benign, with low proportions of patients having splenectomized and aplastic crises.

The Tohoku Journal of Experimental Medicine, 2009

Acute poststreptococcal glomerulonephritis (APSGN) is the most common prototype of acute glomerul... more Acute poststreptococcal glomerulonephritis (APSGN) is the most common prototype of acute glomerulonephritis in children, and is characterized by the sudden onset of gross hematuria, edema, hypertension and volume overload. Brain natriuretic peptide (BNP) is produced in both the brain and the heart. Its prohormone, proBNP, is cleaved to biologically active BNP and an inactive N-terminal peptide of proBNP (NT-proBNP). NT-proBNP is released predominantly from the ventricles in response to hypervolemia and pressure overload. We therefore investigated the relationship between NT-proBNP levels and cardiac functions of patients with APSGN. NT-proBNP levels were measured in 28 patients with APSGN (17 boys and 11 girls of 8.2 +/- 2.9 years old) and in 26 healthy children (control group). Echocardiograms were performed in both patient and control groups on admission, and only in the patient group two weeks later. Upon admission, the plasma NT-proBNP levels were higher in the patients than in the control group (8876.2 +/- 9650.8 vs 69.5 +/- 22.2 pg/mL, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001), and left ventricular dysfunction was detected in six patients. Moreover, NT-proBNP levels were significantly higher in the patients with left ventricular dysfunction than other patients (n = 22). There was no significant difference in the levels of NT-proBNP between the patient and control groups, after diuretic treatment of the patients. Plasma NT-proBNP levels were positively correlated with the severity of APSGN. Thus, NT-proBNP level may be a useful marker to assess the volume overload and cardiac function in the follow up of selected APSGN patients.

European Journal of Pediatrics, 2012

Varicella can cause complications that are potentially serious and require hospitalization. Our c... more Varicella can cause complications that are potentially serious and require hospitalization. Our current understanding of the causes and incidence of varicella-related hospitalization in Turkey is limited and sufficiently accurate epidemiological and economical information is lacking. The aim of this study was to estimate the annual incidence of varicella-related hospitalizations, describe the complications, and estimate the annual mortality and cost of varicella in children. VARICOMP is a multi-center study that was performed to provide epidemiological and economic data on hospitalization for varicella in children between 0 and 15 years of age from October 2008 to September 2010 in Turkey. According to medical records from 27 health care centers in 14 cities (representing 49.3% of the childhood population in Turkey), 824 children (73% previously healthy) were hospitalized for varicella over the 2-year period. Most cases occurred in the spring and early summer months. Most cases were in children under 5 years of age, and 29.5% were in children under 1 year of age. The estimated incidence of varicella-related hospitalization was

BMC Infectious Diseases, 2008

Background: Neonatal tetanus (NT) is still considered as one of the major causes of neonatal deat... more Background: Neonatal tetanus (NT) is still considered as one of the major causes of neonatal death in many developing countries. The aim of the present study was to assess the characteristics of sixty-seven infants with the diagnosis of neonatal tetanus followed-up in the Pediatric Infectious Diseases Ward of Dicle University Hospital, Diyarbakir, between 1991 and 2006, and to draw attention to factors that may contribute (or may have contributed) to the elimination of the disease in Diyarbakir.

American Journal of Ophthalmology, 2013

To determine peripapillary retinal nerve fiber layer (RNFL) thickness values by three-dimensional... more To determine peripapillary retinal nerve fiber layer (RNFL) thickness values by three-dimensional optical coherence tomography (3D-OCT) in a normal Iranian population and to evaluate the concordance of these measurements with those obtained by the second generation of optical coherence tomography (OCT II). Methods: In a cross-sectional observational study, 96 normal Iranian subjects 20-53 years old were enrolled. Peripapillary RNFL thickness in one randomly selected eye of each subject was measured by 3D-OCT and also by OCT II. Standard achromatic perimetry, corneal pachymetry and A-scan ultrasonographic biometry were also performed. Other study variables included age, gender, laterality (right versus left eye), refractive error, corneal diameter and disc area. Results: Mean peripapillary RNFL thickness measured by 3D-OCT (75.50±8.38) µm was significantly less than that measured by OCT II (144.10±33.32 µm) (P<0.001). Using 3D-OCT, no significant difference in peripapillary RNFL thickness was observed by gender (P=0.90) or laterality (P=0.17); RNFL thickness had no correlation with age (P=0.95), axial length (P=0.32), spherical equivalent refractive error (P=0.21), central corneal thickness (P=0.66) and disc area (P=0.31). However, a positive correlation was found between peripapillary RNFL thickness and corneal diameter (P=0.03). Conclusion: 3D-OCT seems to yield lower RNFL thickness values as compared to OCT II. It seems advisable to obtain separate baseline measurements when using different generations of OCT machines.

Human Vaccines & Immunotherapeutics, 2014

Successful vaccination policies for protection from bacterial meningitis are dependent on determi... more Successful vaccination policies for protection from bacterial meningitis are dependent on determination of the etiology of bacterial meningitis. Cerebrospinal fluid (CSF) samples were obtained prospectively from children from 1 month to ≤18 years of age hospitalized with suspected meningitis, in order to determine the etiology of meningitis in Turkey. DNA evidence of Neisseria meningitidis (N. meningitidis), Streptococcus pneumoniae (S. pneumoniae), and Hemophilus influenzae type b (Hib) was detected using multiplex polymerase chain reaction (PCR). In total, 1452 CSF samples were evaluated and bacterial etiology was determined in 645 (44.4%) cases between 2005 and 2012; N. meningitidis was detected in 333 (51.6%), S. pneumoniae in 195 (30.2%), and Hib in 117 (18.1%) of the PCR positive samples. Of the 333 N. meningitidis positive samples 127 (38.1%) were identified as serogroup W-135, 87 (26.1%) serogroup B, 28 (8.4%) serogroup A and 3 (0.9%) serogroup Y; 88 (26.4%) were non-groupable. As vaccines against the most frequent bacterial isolates in this study are available and licensed, these results highlight the need for broad based protection against meningococcal disease in Turkey.