Person: BEREKET, ABDULLAH
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BEREKET
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ABDULLAH
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Publication Metadata only Oral bisphosphonate therapy for vitamin D intoxication of the infant(AMER ACAD PEDIATRICS, 2003) BEREKET, ABDULLAH; Bereket, A; Erdogan, TVitamin D intoxication in infancy has serious consequences attributable to acute hypercalcemia and subsequent hypercalcuria/nephrocalcinosis. Current treatments of patients with vitamin D intoxication are unsatisfactory and associated with prolonged hypercalcemia. We now report the use of oral alendronate sodium in a 3-month-old infant with vitamin D intoxication. Short-term oral alendronate sodium treatment effectively corrected hypercalcemia/hypercalciuria, decreased the duration of hospitalization, and appears safe in 15 months of observation.Publication Metadata only Effects of leukemia inhibitory receptor gene mutations on human hypothalamo-pituitary-adrenal function(SPRINGER, 2015) BEREKET, ABDULLAH; Guran, Tulay; Guran, Omer; Paketci, Cem; Kipoglu, Osman; Firat, Irfan; Turan, Serap; Atay, Zeynep; Haliloglu, Belma; Bereket, AbdullahStuve-Wiedemann syndrome (STWS) (MIM #601559) is a rare autosomal recessive disorder caused by mutations in the leukemia inhibitory factor receptor (LIFR) gene. STWS has a diverse range of clinical features involving hematopoietic, skeletal, neuronal and immune systems. STWS manifests a high mortality due to increased risk of sudden death. Heterodimerization of the LIFR mediates leukemia inhibitory factor (LIF) signalling through the intracellular Janus kinase (JAK)/STAT3 signalling cascade. The LIF/LIFR system is highly expressed in and regulates the hypothalamo-pituitary-adrenal (HPA) axis. HPA function was investigated in three STWS patients to characterise consequences of impaired LIF/LIFR signalling on adrenal function. Six genetically proven STWS patients from four unrelated Turkish families were included in the study. Sudden death occurred in three before 2 years of age. Basal adrenal function tests were performed by measurement of early morning serum cortisol and plasma ACTH concentrations on at least two different occasions. Low dose synacthen stimulation test and glucagon stimulation tests were performed to explore adrenal function in three patients who survived. All patients carried the same LIFR (p.Arg692X) mutation. Our oldest patient had attenuated morning serum cortisol and plasma ACTH levels at repeated measurements. Two of three patients had attenuated cortisol response (< 18 mu g/dl) to glucagon, one of whom also had borderline cortisol response to low dose (1 mu g) ACTH stimulation consistent with central adrenal insufficiency. STWS patients may develop central adrenal insufficiency due to impaired LIF/LIFR signalling. LIF/LIFR system plays a role in human HPA axis regulation.Publication Metadata only The prevalence and risk factors of premature thelarche and pubarche in 4-to 8-year-old girls(WILEY, 2012) BEREKET, ABDULLAH; Atay, Zeynep; Turan, Serap; Guran, Tulay; Furman, Andrzej; Bereket, AbdullahAim: To assess the prevalence of premature thelarche (PT) and pubarche in healthy 4- to 8-year-old girls and to investigate factors associated with early pubertal development. Method: Eight hundred and twenty girls were examined by two paediatric endocrinologists to determine Tanner staging. The effects of body mass index, gestational age, intrauterine growth status, age at the first tooth eruption, socio-economical status, maternal age of menarche and consumption of certain food items on early pubertal development were analysed through parametric and nonparametric tests. Results: The prevalence of PT and of premature pubarche was 8.9% and 4.3%, respectively. We found a strong association between the prevalence of PT and the body mass index standard deviation scores (BMI SDS). There were more girls with BMI SDS values above 1 in the PT group (56.1%) than among the remaining subjects (22.9%). Premature thelarche was not significantly associated with intrauterine growth, premature birth, socioeconomic status, age of first tooth eruption or maternal age of menarche. Similarly, the amount of milk, eggs, chicken or fish consumed was not associated with PT. None of the investigated factors were associated with premature pubarche. Conclusion: Occurrence of PT is strongly associated with BMI SDS. Studies investigating secular trends in pubertal development must consider a secular change in body mass index.Publication Open Access GCK gene mutations are a common cause of childhood-onset MODY (maturity-onset diabetes of the young) in Turkey(WILEY-BLACKWELL, 2016-09) BEREKET, ABDULLAH; Haliloglu, Belma; Hysenaj, Gerald; Atay, Zeynep; Guran, Tulay; Abali, Saygin; Turan, Serap; Bereket, Abdullah; Ellard, SianObjectiveInactivating heterozygous mutations in the GCK gene are a common cause of MODY and result in mild fasting hyperglycaemia, which does not require treatment. We aimed to identify the frequency, clinical and molecular features of GCK mutations in a Turkish paediatric cohort. Design and PatientsFifty-four unrelated probands were selected based on the following criteria: age of diagnosis 17years, family history of diabetes in at least two generations, anti-GAD/ICA negative, BMI<95.p and follow-up with diet, oral antidiabetic drug or low-dose insulin treatment (05U/kg/d). A MODY probability score () was calculated and 21 patients with a score 75%, HbA1c levels 75% (585mmol/mol) and fasting blood glucose (FBG) levels 99-145mg/dl (55-80mmol/l) were selected for Sanger sequencing of the GCK gene. Targeted next-generation sequencing for all known monogenic diabetes genes was undertaken for any patient without a GCK gene mutation. ResultsGCK gene mutations (pathogenic or likely pathogenic variants) and a novel intronic variant of uncertain significance (c.208+3A>T) were identified in 13/54 probands (24%). Twelve of these patients had a MODY probability score 75%. FBG level and 2-h glucose level in OGTT were 12314mg/dl (68 +/- 07mmol/l) (107-157mg/dl) and 181 +/- 30mg/dl (101 +/- 16mmol/l) (136-247mg/dl), respectively. Average of glucose increment in OGTT was 58 +/- 27mg/dl (32 +/- 15mmol/l) (19-120mg/dl), and mean HbA1c level was 65 +/- 05% (475 +/- 55mmol/mol) (59-76%). Five novel missense mutations were identified (p.F123S, p.L58P, p.G246A, p.F419C, and p.S151C). Two patients treated with low-dose insulin before the molecular analysis were able to stop treatment. ConclusionsApproximately 1 in 4 MODY cases in this Turkish paediatric cohort have a GCK mutation. Selection of patients for GCK gene analysis using the MODY probability score was an effective way of identifying most (11/12) patients with a GCK mutation.Publication Metadata only Significance of acanthosis nigricans in childhood obesity(WILEY-BLACKWELL, 2008) BEREKET, ABDULLAH; Guran, Tulay; Turan, Serap; Akcay, Teoman; Bereket, AbdullahAim: Acanthosis nigricans (AN) is among the most common dermatologic manifestations of obesity and hyperinsulinism. In this study, we aimed to find the clinical and laboratory differences in obese children with AN and without AN (non-AN). Methods: In total, 160 obese children were included in the study. The duration of obesity, body mass index (BMI), BMI z-scores, birth weight, parental BMI, lipid profile, fasting and post-meal (PM) glucose and insulin levels were compared in 67 obese with AN and 93 obese without AN. Results: Age was similar in both groups. AN group had higher male to female ratio (42/25 in AN, 43/50 in non-AN; P = 0.03), higher BMI (30.3 +/- 6.1 in AN, 26.4 +/- 3.6 in non-AN; P < 0.001) and weight for height (162.6 +/- 28.8 in AN, 144.6 +/- 15.8 in non-AN; P < 0.001) than non-AN group. There were no significant differences between the groups in birth weight, parental BMI and blood pressure. AN group had higher fasting (19.9 +/- 16.2 mU/L in AN, 10.4 +/- 7.6 mU/L in non-AN; P < 0.001) and PM insulin (88.6 +/- 87.3 mU/L in AN, 51.1 +/- 42.0 mU/L in non-AN; P = 0.01) and homeostasis model assessment for insulin resistance (HOMA-IR) (4.0 +/- 2.5 in AN, 2.2 +/- 1.8 in non-AN; P < 0.001) than non-AN group. However, fasting and PM glucose, triglyceride, low-density lipoprotein-, high-density lipoprotein- and total cholesterol levels were similar in both groups. BMI was correlated with HOMA-IR in both groups (r = 0.40 for AN, r = 0.28 for non-AN). PM glucose and PM insulin were correlated in both groups (r = 0.56 for AN, r = 0.39 for non-AN). However, fasting glucose and fasting insulin were correlated in only non-AN (r = 0.25), but not in AN group. Conclusions: Obese children with AN show higher insulin levels and HOMA-IR. AN is an important predictor of the insulin resistance in childhood obesity. Insulin secretory dynamics seem to be disrupted in fasting state initially, which is reflected as the loss of fasting insulin-glucose correlation in AN group.Publication Metadata only Evaluation and Treatment Results of Ovarian Cysts in Childhood and Adolescence: A Multicenter, Retrospective Study of 100 Patients(ELSEVIER SCIENCE INC, 2017) BEREKET, ABDULLAH; Aydin, Banu Kucukemre; Saka, Nurcin; Bas, Firdevs; Yilmaz, Yasin; Haliloglu, Belma; Guran, Tulay; Turan, Serap; Bereket, Abdullah; Mutlu, Gul Yesiltepe; Cizmecioglu, Filiz; Hatun, Sukru; Bezen, Digdem; Tutunculer, Filiz; Cebeci, Nurcan; Isguven, Pinar; Memioglu, Nihal; Ercan, Oya; Poyrazoglu, Sukran; Bundak, Ruveyde; Darendeliler, FeyzaStudy Objective: To investigate the characteristics of children with ovarian cysts and evaluate treatment strategies. Design: Retrospective study. Setting: Eight pediatric endocrinology clinics, Turkey. Participants: A total of 100 children and adolescents with ovarian cysts. Interventions: Patient data collected via retrospective chart review. Patients were stratified according to age into 4 groups (newborns, 1-12 months, 1-8 years, and 8-18 years). Main Outcome Measures: Special emphasis was given to torsion and tumor cases, concomitant diseases, treatment modalities, and problems during follow-up. Results: Most newborns and infants were asymptomatic with the cysts being discovered incidentally; in girls ages 1-8, symptoms were common, including breast budding (47.1%, 16 of 34) and vaginal bleeding (29.4%, 10 of 34). Girls older than 8 years mostly presented with abdominal pain (31.6%, 12 of 38) and menstrual irregularity (21.1%, 8 of 38). Most of our patients were diagnosed with a simple ovarian cyst, but 9 patients were found to have ovarian tumors. Ovarian torsion was detected in 7 patients; 5 with large and 2 with small cysts (! 20 mm). Two patients had central precocious puberty (CPP) at presentation and 5 patients developed CPP during follow-up. The surgical intervention rate was high (38%, 38 of 100), but was associated with earlier treatment year, and this association remained significant after adjusting for confounders (P = .035). Conclusion: Most girls have simple cysts, which have a favorable prognosis without intervention; however, there might be coexisting pathologies or complications such as tumors, torsion, and CPP; hence these patients should be evaluated accordingly and treated with a multidisciplinary approach.Publication Metadata only Comparison of oral alendronate versus prednisolone in treatment of infants with vitamin D intoxication(WILEY, 2012) BEREKET, ABDULLAH; Sezer, Rabia G.; Guran, Tulay; Paketci, Cem; Seren, Lale P.; Bozaykut, Abdulkadir; Bereket, AbdullahAim: The aim of this report was to compare the efficacy of oral alendronate versus prednisolone treatment in addition to conventional measures in infants with vitamin D intoxication. Methods: In six infants (aged 8.0 +/- 2.1 months) with vitamin D intoxication, time to achieve normocalcemia with prednisolone treatment (Group I, n = 4) or alendronate treatment (Group II, n = 4, two infants started treatment from the baseline and two after unsuccessful prednisolone treatment) in addition to intravenous hydration and diuretic therapy were compared. Results: Baseline serum calcium levels ranged between 3.8 and 4.77 mmol/L. In the prednisolone group, although two patients reached normocalcemia on 7th and 12th days of treatment, other two patients did not despite 23 and 15 days of treatment and therefore switched to alendronate treatment. The mean duration of prednisolone treatment in these four patients was 14.2 +/- 6.7 days (range 7-23). In the alendronate group, two patients who started treatment from the baseline achieved normocalcemia on the 5th day. Other two patients achieved normocalcemia 2 days after switching to alendronate. Thus, the mean time to reach normocalcemia after single oral alendronate administration was 3.5 +/- 1.7 days (range 2-5) (p < 0.01 versus Group I). Conclusion: Alendronate treatment achieves normocalcemia four times earlier than prednisolone treatment and shortens hospital stay in infants with vitamin D intoxication.Publication Metadata only Adrenal steroids reference ranges in infancy determined by LC-MS/MS(SPRINGERNATURE) BEREKET, ABDULLAH; Enver, Ece Oge; Vatansever, Pinar; Guran, Omer; Bilgin, Leyla; Boran, Perran; Turan, Serap; Haklar, Goncagul; Bereket, Abdullah; Guran, TulayBackground Interpretation of the results of steroid hormone measurements is challenging at early infancy. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) method provides a powerful tool for diagnosing steroidogenesis disorders. We aimed to develop normative data for a 14-steroid panel and four adrenal enzyme activity indices, determined by LC-MS/MS from 3 days to 6 months of age. Methods Age- and sex-specific plasma steroid concentrations were calculated in 324 healthy full-term neonates and infants (151 females). Percentile curves were devised. Steroid ratios were evaluated as biomarkers of adrenal enzyme activities. The steroid profiles of four patients with adrenal enzyme deficiencies were included to test the diagnostic efficiency. Results Nine steroids showed age, but none showed sex specificity. The concentrations of progestins and androgens were higher at 7-14 days than at 3-7 days. After the first month, adrenal androgen concentrations decreased significantly. Adrenal enzyme activities changed towards increasing cortisol over the first 6 months. There were several-fold differences in diagnostic steroids and related adrenal enzyme activity indices between the patients and the healthy group. Conclusions The majority of adrenal steroids show age-related variations in the neonatal period and early infancy. Our data will enable accurate interpretation of steroid measurements for etiologic diagnosis of disorders of steroidogenesis. Impact LC-MS/MS method is capable of quantitating numerous analytes simultaneously, which provides an integrated picture of adrenal steroidogenesis in a small amount of sample. The development of LC-MS/MS-based normative data of steroid hormones in healthy infants is crucial to differentiate physiologic alterations from steroidogenic defects during the first 3-6 months of infancy. Previous studies had limitations due to the small numbers of samples available by sex and by age groups. Our detailed normative data and percentile curves will enable accurate interpretation of steroid measurements for etiologic diagnosis of disorders of steroidogenesis without the need for further invasive testing.Publication Metadata only Content analysis of food advertising in Turkish television(WILEY, 2010) BEREKET, ABDULLAH; Guran, Tulay; Turan, Serap; Akcay, Teoman; Degirmenci, Fatih; Avci, Okan; Asan, Abdulkerim; Erdil, Emre; Majid, Abdulaziz; Bereket, AbdullahAim: Television (TV) viewing has been implicated in children's weight gain. We aimed to conduct a comprehensive content analysis of TV food advertising in Turkey. Methods: TV advertisements (ads) in the four most popular national free to air Turkish TV channels, were assessed on two weekdays and two weekend days at four time periods of the day; 0800-1200,1200-1600,1600-2000 and 2000-2400 h for each TV channel (64 h assessed for each TV channel), making a total of 256 h. Each ad was analysed for food and drink content, duration and audiovisual properties. Results: There were 8853 TV ads and 2848 of these were related to food (32.1%). A majority of food ads included high-calorie, high-fat, high-sugar food and drink rather than core/healthy foods (81%). Chocolate and chocolate bars were the most frequently advertised food/drink product, followed by cakes, coffee, tea, candies, gum, fast food, chips, juices/carbonated beverages, margarine and ice-cream formed the highest rate of food products advertised in decreasing order. Thirty per cent of all obesogenic/unhealthy ads targeted childhood by using audiovisual techniques. The proportion of total advertisements which were for food or drink, and the proportion of food advertisements that were for unhealthy foods were both much higher at the weekend (33% vs. 30% and 84% vs. 78%, respectively). The time period between 1600 and 2000 h was the most concentrated time slot (33%) for food advertising. Conclusions: This study provides data for the first time on the high levels of obesogenic food advertising on Turkish TV. This should alarm policy-makers to set limits on food advertising targeted towards children especially in countries like Turkey in which childhood obesity is emerging as an important public health issue.