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Featured researches published by Yasar Dogan.


Mediators of Inflammation | 2006

Serum IL-1β, IL-2, and IL-6 in insulin-dependent diabetic children

Yasar Dogan; Saadet Akarsu; Bilal Ustundag; Erdal Yilmaz; Metin Kaya Gürgöze

Insulin-dependent diabetes mellitus (IDDM) is a chronic disease characterized by T-cell-dependent autoimmune destruction of the insulin-producing β cells in the pancreatic islets of Langerhans, resulting in an absolute lack of insulin. T cells are activated in response to islet-dominant autoantigens, the result being the development of IDDM. Insulin is one of the islet autoantigens responsible for the activation of T-lymphocyte functions, inflammatory cytokine production, and development of IDDM. The aim of this study was to investigate serum concentrations of interleukin (IL)-1β, IL-2, IL-6, and tumor necrosis factor (TNF)-α in children IDDM. The study population consisted of 27 children with IDDM and 25 healthy controls. Children with IDDM were divided into three subgroups: (1) previously diagnosed patients (long standing IDDM) (n : 15), (2) newly diagnosed patients with diabetic ketoacidosis (before treatment) (n : 12), and (3) newly diagnosed patients with diabetic ketoacidosis (after treatment for two weeks) (n : 12). In all stages of diabetes higher levels of IL-1β and TNF- α and lower levels of IL-2 and IL-6 were detected. Our data about elevated serum IL-1β, TNF- α and decreased IL-2, IL-6 levels in newly diagnosed IDDM patients in comparison with longer standing cases supports an activation of systemic inflammatory process during early phases of IDDM which may be indicative of an ongoing β-cell destruction. Persistence of significant difference between the cases with IDDM monitored for a long time and controls in terms of IL-1β, IL-2, IL-6, and TNF-α supports continuous activation during the late stages of diabetes.


Mediators of Inflammation | 2007

Serum IL-1beta, IL-6, IL-8, and TNF-alpha levels in early diagnosis and management of neonatal sepsis.

A. Nese Citak Kurt; A. Denizmen Aygün; Ahmet Godekmerdan; Abdullah Kurt; Yasar Dogan; Erdal Yilmaz

Aim. To determine serum IL-1β, IL-6, IL-8, and TNF-α levels in neonatal sepsis at the time of diagnosis and after therapy, and to show the meaningful on the follow up. Methods. This prospective study was performed on newborns who were hospitalized for neonatal sepsis and who were classified as culture-proven sepsis (n=12), as culture-negative sepsis (n=21), and as healthy newborns (n=17). Results. At the time of diagnosis, serum IL-1β, IL-6, IL-8, and TNF-α levels of culture-proven sepsis were significantly higher than those of the control groups (P<.05). At the time of diagnosis, IL-1β, IL-6, IL-8, and TNF-α levels of culture-proven sepsis and culture-negative sepsis were significantly higher than levels at the seventh day after antibiotic treatment. Conclusion. Serum IL-1β, IL-6, IL-8, and TNF-α are mediators of inflammation and can be used at the diagnosis and at the evaluation of the therapeutic efficiency in neonatal sepsis.


Clinical Pediatrics | 2006

Caustic Gastroesophageal Lesions in Childhood: An Analysis of 473 Cases

Yasar Dogan; Tülay Erkan; Fügen Çokuğraş; Tufan Kutlu

Ingested corrosive agents produce oropharyngeal and gastroesophageal injuries ranging from minor burns to severe necrosis, depending on the agent amount, concentration, and duration of exposure. The aim of this study was to present our patients with corrosive ingestion retrospectively. Four hundred seventy-three children younger than 16 years of age (mean age, 3.7±0.1 years) who were admitted to our hospital for suspected corrosive ingestion between the years 1995 and 2003 were studied. Two hundred eighty-six (60.5%) of 473 patients were males. Household bleaches (36.6%) and oven cleaners (23%) were the most frequently encountered corrosive agents. During endoscopy, lesions in the esophagus were recorded in 379 children. Eighty-one of the cases had gastric lesions. During the follow-up, esophageal stricture, esophageal perforation, and gastric outlet obstruction (GOO) developed in 11 cases, 1 case, and 2 cases, respectively. Caustic ingestion of alkali substances such as oven cleaner seem to cause more severe injuries. Early admission to the hospital with clinical and endoscopic evaluation and early surgery when required may reduce morbidity and mortality.


Mediators of Inflammation | 2005

Levels of cytokines (IL-1beta, IL-2, IL-6, IL-8, TNF-alpha) and trace elements (Zn, Cu) in breast milk from mothers of preterm and term infants.

Bilal Ustundag; Erdal Yilmaz; Yasar Dogan; Saadet Akarsu; Halit Canatan; Ihsan Halifeoglu; Gurkan Cikim; A. Denizmen Aygün

It has been well documented that human milk contains several immunomodulator components which are important during infant period when the newborns immune system is still under development. In this study, we aim at examining levels of cytokines, zinc (Zn), and copper (Cu) in milk from mothers of premature and mature infants, and comparing changes during lactation periods consequently. Milk was collected from total of 40 mothers (group M: mothers of mature infants, n = 20; group PM: mothers of premature infants, n = 20) from four lactation stages: colostrum (0–7 days), transitional (7–14 days), mature milk (21 days), and mature milk (2nd month). Levels of cytokines (interleukin [IL]-lβ, IL-2, IL-6, IL-8, tumor necrosis factor-alpha [TNF-α]) were determined by chemiluminesence method, whereas atomic absorption spectrophotometer was used for the determination of Zn and Cu levels. Cytokine levels were determined to be high in colostrum and transient milk from mothers of full-term infants, whereas their levels were reduced drastically in the 21st day and the 2nd month milk (P < .01 , P < .001). Similar trends were observed in milk from mothers of premature infants, but cytokine levels were significantly lower in colostrum compared to colostrum from mothers of mature infants (P < .01). The differences in cytokine levels were continuous in transient milk (P < .05) and mature milk (21 days) (P < .05), whereas there was no statistically significant differences between milk from both groups of mothers in the 2nd month (P > .05). Zn levels in milk from mothers of premature infants were significantly lower compared to the ones from mothers of mature infants (P < .01) and these differences continued through the 2nd month. Although Cu levels were lower in milk from mothers of premature infants, there was no statistically significant difference except colostrum (P > .05). Our results clearly demonstrate that the level of immunomodulating agents such as cytokines and trace elements in milk from mothers of premature infants is less than the level of the same agents in milk from mothers of full-term infants. Although there are commercially available products for infant feeding, human milk is still the best natural nutrient for newborns. Therefore, when premature infants are breastfed, necessary precautions such as supplemantary diets must be considered for possible infections and risks related with immune system deficiency.


Annals of Tropical Paediatrics | 2005

Carboxyatractyloside poisoning in humans.

Mehmet Turgut; Cafer Cumhur Alhan; Metin Kaya Gürgöze; Abdullah Kurt; Yasar Dogan; Muhittin Tekatli; Nusret Akpolat; A. Denizmen Aygün

Abstract Objective: Cocklebur (Xanthium strumarium) is an herbaceous annual plant with worldwide distribution. The seeds contain the glycoside carboxyatractyloside, which is highly toxic to animals. We describe nine cases of carboxyatractyloside poisoning in humans which, to our knowledge, has not previously been reported. The clinical, laboratory and histopathological findings and our therapeutic approach are also discussed. Subjects and methods: The patients presented with acute onset abdominal pain, nausea and vomiting, drowsiness, palpitations, sweating and dyspnoea. Three of them developed convulsions followed by loss of consciousness and death. Results: Laboratory findings showed raised liver enzymes, indicating severe hepatocellular damage. BUN and creatinine levels were raised, especially in the fatal cases who also displayed findings of consumption coagulopathy. CPK–MB values indicative of myocardial injury were also raised, especially in the fatal cases. Three of the patients died within 48 hours of ingesting carboxyatractyloside. Post-mortem histopathology of the liver confirmed centrilobular hepatic necrosis and renal proximal tubular necrosis, secondary changes owing to increased permeability and microvascular haemorrrage in the cerebrum and cerebellum, and leucocytic infiltrates in the muscles and various organs including pancreas, lungs and myocardium. Conclusions: Carboxyatractyloside poisoning causes multiple organ dysfunction and can be fatal. Coagulation abnormalities, hyponatraemia, marked hypoglycaemia, icterus and hepatic and renal failure are signs of a poor prognosis. No antidote is available and supportive therapy is the mainstay of treatment.


Clinics and Research in Hepatology and Gastroenterology | 2014

Protective effects of L-carnitine, N-acetylcysteine and genistein in an experimental model of liver fibrosis

Kaan Demiroren; Yasar Dogan; Halil Kocamaz; Ibrahim Hanifi Ozercan; Selcuk Ilhan; Bilal Ustundag; Ibrahim Halil Bahcecioglu

AIM Liver fibrosis is a reversible wound-healing response that occurs following liver injury. In this study, we aimed to investigate the possible protective effects of L-carnitine, N-acetylcysteine and genistein in liver fibrosis induced by carbon tetrachloride (CCl4). In addition, the effects of these agents were compared in the same study. METHODS In this study, rats were randomly allocated into 8 groups, consisting of 10 rats each, as follows: a control group, CCl4, L-carnitine, N-acetylcysteine, genistein, CCl4 and L-carnitine, CCl4 and N-acetylcysteine, and CCl4 and genistein. At the end of 6 weeks, blood and liver tissue specimens were collected. Alanine aminotransferase (ALT); aspartate aminotransferase (AST); complete blood count, tumor necrosis factor-α (TNF-α); platelet-derived growth factor-BB (PDGF-BB); interleukin-6 (IL-6); liver glutathione level; oxidant/antioxidant status; scores of hepatic steatosis, necrosis, inflammation, and fibrosis; and the expression of α-smooth muscle actin were studied. RESULTS Although the ALT and AST values in the group administered CCl4 were significantly higher than in all the other groups (P<0.05), there was no significant difference between the control group and the groups administered CCl4 combined with L-carnitine, N-acetylcysteine and genistein (P>0.05). There were significant differences in the levels of TNF-α, PDGF-BB and IL-6 (P<0.05) between the CCl4 group and the groups with L-carnitine, N-acetylcysteine and genistein added to CCl4. N-acetylcysteine and genistein had positive effects on the oxidant/antioxidant status and on liver necrosis and fibrosis scores. CONCLUSIONS In our study, L-carnitine, N-acetylcysteine and genistein showed significant protective effects in liver fibrosis induced by CCl4.


Mediators of Inflammation | 2005

The differential diagnostic values of cytokine levels in pleural effusions.

Saadet Akarsu; A. Nese Citak Kurt; Yasar Dogan; Erdal Yilmaz; Ahmet Godekmerdan; A. Denizmen Aygün

The aim is to examine whether the changes in pleural fluid interleukin (IL)-1β, IL-2, IL-6, and IL-8 levels were significant in differential diagnosis of childhood pleural effusions. IL-1β, IL-2, IL-6, and IL-8 levels in pleural fluids of all 36 patients were measured. The levels of IL-1β, IL-2, IL-6, and IL-8 in pleural fluids were statistically significantly higher in the transudate group compared with those of the exudate group. The levels of IL-1β, IL-6, and IL-8 were also found to be statistically significantly higher in the empyema group compared with both the parapneumonic and the tuberculous pleural effusion groups. The levels of IL-2 and IL-6 were detected to be statistically significantly higher in the tuberculous pleural effusion group in comparison with those of the parapneumonic effusion group. The results showed that pleural fluids IL-1β, IL-2, IL-6, and IL-8 could be used in pleural fluids exudate and transudate distinction.


Mediators of Inflammation | 2007

The Levels of Ghrelin, TNF-α, and IL-6 in Children with Cyanotic and Acyanotic Congenital Heart Disease

Erdal Yilmaz; Bilal Ustundag; Yasar Sen; Saadet Akarsu; A. Nese Citak Kurt; Yasar Dogan

Background/Aim. Ghrelin has effects on nutrient intake and growth. The cause of growth retardation in congenital heart disease is multifactorial. The aim of the present study is to investigate the ghrelin in congenital heart disease and the association of ghrelin with TNF-α and IL-6. Materials and methods. We measured serum ghrelin, TNF-α, and IL-6 levels using spesific immunoassay in 68 patients (47 acyanotic, 21 cyanotic with congenital heart disease) and in 25 control subjects. Results. In comparison to controls, serum ghrelin, TNF-α levels were significantly higher in acyanotic patients and cyanotic patients with congenital heart disease (P<.0001). In acyanotic and cyanotic patients with congenital heart disease, there was a positive correlation between ghrelin and TNF-α (r=.485, P<.05 and r=.573, P<.01, resp.). Conclusion. Serum ghrelin levels is elevated in acyanotic and cyanotic patients with congenital heart disease. Increased ghrelin levels represents malnutrition and growth retardation in these patients. The relation of ghrelin with cytokines may be explained by the possible effect of chronic congestive heart failure and chronic shunt hypoxemia.


Pediatric Hematology and Oncology | 2003

Severe Protein S Deficiency Associated with Heterozygous Factor V Leiden Mutation in a Child with Purpura Fulminans

Yasar Dogan; Denizmen Aygun; Yelda Yılmaz; Kanra G; Seçmeer G; Nesrin Besbas; Aytemiz Gurgey

Homozygous or compound heterozygous protein S (PS) deficiency is very rare in the population; only 8 patients from 6 different families have been reported. On the other hand, the factor V Leiden (FVL) mutation is a frequent cause of inherited prothrombotic disorder. Here the authors report a case of patient with severe PS deficiency associated with the FVL mutation who has had purpura fulminans since the age of 10 days. She is the first child of a consanguineous marriage. Her father is double heterozygous for PS deficiency and FVL mutation and has recurrent thrombosis. This is the first case of severe PS deficiency combined with the FVL mutation. This suggests the need for complete evaluation of patients with purpura fulminans for thrombotic factors.


Journal of Pediatric Gastroenterology and Nutrition | 2012

Prevalence of celiac disease among first-degree relatives of patients with celiac disease.

Yasar Dogan; Yildirmaz S; Ozercan Ih

Objectives: Celiac disease, an autoimmune enteropathy that affects the proximal small intestine, is characteristically seen in people who have a genetic susceptibility to gluten sensitivity. Celiac patients’ first-degree relatives are more at risk of acquiring the disease. The objective of the present study was consequently to determine the prevalence of celiac disease in a group of first-degree relatives of our patients with celiac disease. Methods: First-degree relatives of 195 patients with celiac disease attending a gastroenterology unit underwent serologic screening. Antitissue transglutaminase (anti-tTG) immunoglobulin A (IgA) and total serum IgA tests were used for first-level screening. Duodenal biopsy was recommended to subjects showing positive results to anti-tTG IgA testing. Biopsy samples were obtained by endoscopy, and biopsy specimens were evaluated and classified according to Marsh classification. Results: Positive anti-tTG IgA was found in 46 first-degree relatives (9.5%), whereas serum IgA levels were normal. Of 46 serology-positive relatives, 34 agreed to the endoscopy procedure. Histological changes characteristic of celiac disease were found in 23 subjects. The prevalence of celiac disease among the first-degree relatives was found to be at least 4.8%. Of 34 subjects that underwent biopsy, 11 were evaluated as Marsh 0, 5 as Marsh 1, 4 as Marsh 2, 12 as Marsh 3, and 2 as Marsh 4. Of the biopsy-positive subjects, 3 were mothers, 1 was a father, and 19 were siblings. Conclusions: The present study identified 23 undiagnosed cases of celiac disease among 484 first-degree relatives of 195 patients with celiac disease, confirming the high prevalence (4.8%) of the disease in this specific group. It is suggested that an extensive screening policy be mandatory for these subjects.

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