Yonca Egin
Ankara University
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Featured researches published by Yonca Egin.
International Journal of Pediatric Otorhinolaryngology | 2002
Aykut İkincioğulları; Figen Dogu; Aydan Ikinciogullari; Yonca Egin; Emel Babacan
OBJECTIVE Tonsils and adenoids are lymphoid tissues that are located in the pharynx and play an important role against invading antigens of the upper respiratory tract. The present study analyses serum immunoglobulin levels and peripheral blood (PB) lymphocyte subsets in children, 24-48 h prior to and 4-6 weeks after adenotonsillectomy, in order to determine early effects of adenotonsillectomy on the immune system. METHODS The study population consists of 15 children (aged 4-10 years) who underwent adenotonsillectomy because of adenoidal hypertrophy and chronic tonsillitis and 15 age-matched healthy children without a history of adenotonsillectomy. Serum IgG, IgA and IgM levels were measured by nephelometry. PB lymphocyte subsets were analysed by using monoclonal antibodies and flow cytometry. RESULTS Children with chronic tonsillitis have increased levels of CD19+ B lymphocytes compared to healthy controls in the pre-operative period. The percentage of B lymphocytes bearing CD23 was found to be significantly higher in patients, most likely representing in vivo B lymphocyte activation due to chronic antigenic stimulation. After the adenotonsillectomy, despite ongoing B lymphocyte activation, CD8+ T lymphocyte levels increased and B cell levels returned to normal. A slight decrease in serum IgG, IgA and IgM levels was detected in the post-operative period compared to prior levels. CONCLUSION Adenotonsillectomy performed in children leads to alterations that may reflect a compensatory response of the developing immune system after the removal of the lymphoid tissue in the setting of chronic antigenic stimulation. However, these changes do not cause significant immune deficiency.
Pediatric Hematology and Oncology | 1998
Tansu Sipahi; Nejat Akar; Yonca Egin; Cin S
The aim of this study was to investigate the serum levels of interleukin-2 (IL-2) and interleukin-6 (IL-6) in children with iron deficiency anemia before and after iron supplementation. Twenty-five children with iron deficiency anemia 6 months to 3 years of age were included in the study. Ten age- and sex-matched healthy children constituted the control group. In the iron-deficiency group the production of IL-2 was found to be significantly lower than that in controls and became normal after iron supplementation (P < .001). But there was no difference in serum levels of IL-6 in iron deficiency anemia before and after iron supplementation (P > .05).
Clinical and Applied Thrombosis-Hemostasis | 2009
Denizay Yürürer; Serap Teber; Gülhis Deda; Yonca Egin; Nejat Akar
The aim of the authors is to examine the relationship between the cytokine levels that are thought to be involved in stroke etiopathogenesis (tumor necrosis factor [TNF]-α, interleukin [IL]-2, IL-6, IL-8, IL-11), soluble protein C receptor (sEPCR), and factor VIII (FVIII) levels. The study included 27 patients with stroke and 30 healthy controls, aged 0 to 18. In the comparison of the sEPCR, cytokine, and FVIII levels between patient and control groups, median levels of TNF-α, IL-2, IL-6, and IL-8 are found to be high in the patient group when compared with controls, whereas there is no difference in sEPCR, IL-11, and FVIII levels. In the patient group, a positive correlation is seen between TNF-α levels and IL-2 and IL-6 levels, between IL-2 and IL-6 levels, and between IL-6 and IL-8 levels, whereas a negative relationship is seen between sEPCR and FVIII. In the control group apart from the patient group, a negative relationship is seen between TNF-α and FVIII, whereas there is a positive relationship between IL-11 and sEPCR levels. Median sEPCR levels in patients who have normal or low FVIII levels are significantly high when compared with those with high FVIII levels. In conclusion, in the pediatric population, an increase in TNF-α, IL-2, IL-6, and IL-8 levels is seen. Also, an inverse relationship of sEPCR and FVIII levels is shown for the first time. This study provides a basis for ongoing studies that aim to clarify stroke etiopathogenesis. Studies with larger series of patients are warranted to confirm this hypothesis.
Breast Cancer Research and Treatment | 2009
Ragip Çam; Aydan Eroğlu; Yonca Egin; Nejat Akar
The causes of breast cancer (BC) are not clearly known, although different genetic and environmental factors play role in its development. Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in folate-mediated onecarbon metabolism, regulating the DNA methylation and synthesis. Reduced MTHFR activity is associated with genomic DNA hypomethylation. MTHFR is suspected to play a role in the etiology of cancer, via its effects on DNA methylation and nucleotide synthesis [1]. The C to T substitution at nucleotide 677 of MTHFR gene converts an alanine to a valine is associated with reduced enzyme activity and causes increased plasma homocysteine levels. Associations of MTHFR C677T polymorphism with BC have been investigated [1–4]. Dihydrofolate reductase (DHFR) is also important folate metabolizing enzyme that is essential for DNA synthesis and homocysteine remethylation. Recently, Johnson et al. described a 19-bp deletion polymorphism in intron-1 of DHFR that might affect gene expression [5]. More recently, Gellekink et al. reported that 19-bp del/del genotype was associated with a lower plasma homocysteine level and suggested that 19-bp deletion might increase DHFR expression thereby facilitating homocysteine remethylation [6]. The aim of the present study was to evaluate the association of BC risk with MTHFR C677T and DHFR 19-bp deletion polymorphisms. The study consisted of 110 women with BC. Ninety-five healthy women (in matched control) were used as control. Genomic DNA isolation was performed from peripheral venous blood by standard phenol–chloroform extraction, and polymerase chain reaction of 19-bp deletion polymorphism in intron-1 of DHFR was performed according to previously described method [5], using the following primers: F 50-CCACGGTCGGGGTACCTGGG-30, F 50ACGGTCGGGGTGGCCGACTC-30 and R 50-AAAAGGG GAATCCAGTCGG-30. Amplification was made as follows: initial denaturation of one min at 94 C; followed by 35 cycles of 94 C/55 s, 64 C/55 s, 72 C/55 s, and final extension of 12 min at 72 C (Biometra, Germany). The resulting PCR products were 96-bp and 113-bp. Amplified products were subjected to 4% agarose gel. Genotype data were obtained from 179 subjects. MTHFR C677T polymorphism was determined by using commercially available LightCycler kit (Roche Diagnostic, Roche Molecular Biochemicals, Mannheim, Germany). Genotype data were obtained from 205 cases. The groups were compared using v test and P-value \ 0.05 was considered significant. No differences were observed in the distribution of MTHFR C677T genotype or allele frequencies in the BC cases versus control subjects (P [ 0.05; Table 1). A slightly increased frequency of TT genotype in cancer patients was found but this did not reach statistical significance. We did not find a significant association of DHFR 19-bp deletion polymorphism with BC risk. The frequency of 19-bp deletion allele was lower in BC patients than in control group. Various groups have evaluated the association between MTHFR C677T polymorphism and BC risk, though the findings were conflicting. Some authors observed an increased risk for the carriers of TT genotype. Recent R. Çam A. Eroglu (&) Department of General Surgery, Ankara University Medical School, Cebeci Kampus, Ankara 06590, Turkey e-mail: [email protected]
Annals of Hematology | 2009
Aydan Eroğlu; Yonca Egin; Ragip Çam; Nejat Akar
Venous thromboembolism (VTE) is a common complication in cancer patients. Several genetic risk factors related to thrombophilia are known; however, their contributions to thrombotic tendency in cancer patients have conflicting results. In the present study, we have focused on the prevalence of methylenetetrahydrofolate reductase (MTHFR) C677T, dihydrofolate reductase (DHFR) 19-bp deletion within intron 1, factor V Leiden (FVL), and prothrombin (PT) G20210A polymorphisms in cancer patients with and without VTE. The study consisted of 63 cancer patients with VTE (group 1) and 124 cancer patients who had no evidence of VTE (group 2). Four gene polymorphisms were determined by the method of polymerase-chain-reaction-based DNA analysis. The prevalence of DHFR 19-bp deletion and MTHFR C677T polymorphisms was similar in two groups (p > 0.05). The frequency of FVL was significantly higher in group1 compared with group 2 (31.7% vs. 1.6%, p < 0.0001), but PT G20210A polymorphism was not associated with VTE. Cancer patients with thrombosis should be evaluated for FVL, but routine screening for PT G20210A, MTHFR C677T and DHFR 19-bp deletion polymorphisms is not suggested.
Clinical and Applied Thrombosis-Hemostasis | 2012
Duygu Ozel-Demiralp; Naşit İğci; Beycan Ayhan; Yonca Egin; Ibrahim C. Haznedaroglu; Nejat Akar
Ankaferd blood stopper (ABS) is a novel topical hemostatic agent of plant origin registered for the management of external hemorrhages, in Turkey. The ABS-induced formation of the protein network with vital erythroid aggregation covers the whole physiological hemostatic process. The aim of this study is to assess prohemostatic and antithrombin effects of ABS on the basis of functional proteomic analyses performed in ABS-treated plasma and serum samples based on the previous hypotheses about ABS action. For this purpose, serum and plasma proteins were separated by 2-dimensional (2D) gel electrophoresis, and proteins were identified using reference plasma gel on Swiss-2DPAGE database. Our results indicated that fibrinogen gamma chain and prothrombin levels just initially decreased first and thereafter enhanced following the ABS exposure. Dual effects of ABS on those critical hemostatic molecules seem to be associated with prohemostatic and antithrombin activities of the hemostatic agent.
Pediatric Neurosurgery | 2009
Bakhouche Houcher; Romyla Bourouba; Farida Djabi; Erkan Yilmaz; Yonca Egin; Nejat Akar
Background: Neural tube defects (NTD) are severe congenital malformations due to a failure in neural tube formation at the beginning of pregnancy. The etiology of NTD is multifactorial, with environmental and genetic determinants. We suggest a study of gene-gene interactions regarding the possible association of NTD with specific mutations of 5,10-methylenetetrahydrofolate reductase (MTHFR) and cystathionine β-synthase (CBS) genes. Patients and Methods: The genetic analysis of the MTHFR C677T polymorphism was performed by real-time polymerase chain reaction (PCR) on a Light Cycler, the CBS genotype was analyzed by PCR in a thermal cycler. Ninety-two mothers who had conceived NTD children and 48 fathers were investigated. A group of 147 adults, including 82 apparently healthy women, was used as control. Results: Among control mothers, 35 (43%) were heterozygous for the C677T variant and 14 (17%) were TT homozygous. Among the cases, 25 (52%) out of 48 mothers and 22 (46%) out of 48 fathers carried the T allele; 9 mothers (19%) and 5 fathers (10%) had the TT genotype. A homozygous C677T mutation was not an NTD risk factor in this preliminary study in an Algerian population; a possible gene-gene interaction between the MTHFR C677T polymorphism and the CBS 844ins68 has also been examined in relation to NTD, but no such association has been shown. There was a statistically significant difference between the heterozygosity genotype frequency of CBS polymorphisms in mothers with a previous child with NTD compared with the mother controls (odds ratio: 3.72; 95% CI: 1.59–8.73). Conclusion: Our results with Algerian NTD mothers did not show a significant association for any group, suggesting that the thermolabile variant C677T in the MTHFR gene is not a risk factor for a mother to have NTD offspring; rather, folic acid supplementation or fortification should become mandatory for all women of reproductive age in Algeria.
Clinical and Applied Thrombosis-Hemostasis | 2009
Romyla Bourouba; Bakhouche Houcher; Farida Djabi; Yonca Egin; Nejat Akar
The polymorphic mutation 677 C-T in the methylenetetrahydrofolate reductase (MTHFR) gene presents a heterogeneous worldwide distribution and is associated with different disorders such as cardiovascular disease. Its frequency shows great ethnic and geographic variations. The aim of this work is to determine the frequency of MTHFR 677 C-T and coexistence of MTHFR 677 C-T with 2 other common, hereditary thrombophilia causes—namely, factor V 1691 G-A and prothrombin (PT) 20210 G-A mutation—in the Sétif region of Algeria. The study involved 147 apparently healthy participants (82 men and 65 women). Genotyping was carried out by a real-time polymerase chain reaction. The MTHFR 677T carrier frequency was found to be 54.4% (80/147); 59 individuals were heterozygous (40.1%), and 21 were homozygous (14.3%). The frequency of MTHFR 677T was found to be 34.3%. Among the 147 individuals, 3 (2.0%) had factor V Leiden, and 5 (3.4%) had PT 20210 A mutation. Of the 80 participants with MTHFR 677T mutation, 2 had heterozygote factor V 1691 G-A gene mutation, and 4 had heterozygote PT 20210 G-A gene mutation. The results showed that MTHFR 677T prevalence is quite high: an allelic frequency of 34.3% with a genotype frequency of 14.3%. Factor V 1691 G-A and PT 20210 G-A gene mutations are rare in the healthy population of the Sétif region of Algeria.
Graefes Archive for Clinical and Experimental Ophthalmology | 2008
F. Nilüfer Yalçındağ; Figen Batioglu; Özden Özdemir; Esra Cansızoğlu; Yonca Egin; Nejat Akar
BackgroundThe protein C system is an important natural anticoagulant mechanism. Endothelial cell-activated protein C receptor (EPCR), which was discovered at the surface of endothelial cells, binds protein C and enhances its activation. The soluble form of EPCR (sEPCR) has been detected in plasma. Behçet’s disease is a chronic inflammatory disorder affecting multiple organs. Arterial and venous thrombosis is a common clinical manifestation of Behçet’s disease and the pathogenic mechanism of thrombotic tendency in the disease is not well known. The aim of this study is to determine sEPCR concentrations in Behçet patients with and without ocular involvement as well as to investigate the association between sEPCR levels and clinical manifestations of Behçet’s disease.MethodsSixty patients with Behçet’s disease and 67 healthy control subjects were included in this study. A complete ophthalmic examination was performed by ophthalmologists with an interest in Behçet’s disease. Sixty patients with Behçet’s disease were divided into two groups. Group 1 consisted of 30 patients with ocular involvement and Group 2 consisted of 30 patients without ocular involvement. Soluble EPCR levels were determined in plasma by using sEPCR Asserachrom enzyme-linked immunosorbent assay (ELISA) kits according to the manufacturer’s instructions. Differences of the mean sEPCR levels between groups were evaluated using Mann-Whitney U-test. Pearson’s correlation analysis was used for evaluating the correlation between sEPCR levels and age, gender, duration of the disease as well as different clinical manifestations of Behçet’s disease.ResultsAge and gender ratio were not different between patients and controls. Plasma sEPCR concentrations were significantly higher in patients with Behçet’s disease than those in controls (p<0.05). There was no statistically significant difference in serum sEPCR levels between the patients with versus the ones without ocular involvement. There were no statistically significant correlations between sEPCR levels and age, gender, duration of the disease or clinical manifestations.ConclusionsOur data suggests a possible role of soluble EPCR in the pathogenesis of Behçet’s disease. Further studies by possible mutations and polymorphisms in EPCR gene in patients with Behçet’s disease would be useful to bring to light the pathogenic mechanism of ocular and systemic vascular complications of the disease.
International Journal of Gynecology & Obstetrics | 2008
Seyit Temel Ceyhan; Cengiz Beyan; Muhterem Bahçe; Iskender Baser; Kürşat Kaptan; Ahmet Ifran; Yonca Egin; Nejat Akar
Neural tube defects (NTDs) are one of the most common fetal defects. The causes of these defects are considered to have multiple factors involving nutritional deficiencies, genetic predisposition, and environmental factors such as drug exposure [1]. The aim of our study was to investigate the frequencies of thrombophilia-associated gene factor V Leiden mutations and prothrombin gene G20210A mutations, as well as methylenetetrahydrofolate reductase MTHFR C677T mutation which has a substantial role in the folate mechanism of women experiencing pregnancies with NTDs. This study consisted of 2 groups: group 1 consisted of 29 women whose previous pregnancies were complicated with NTDs, and group 2 was the control group consisting of 35 women who experienced uncomplicated pregnancies. The ages of patients in the control group matched with those in the NTD group. Case characteristics are displayed in Table 1. The frequency of theMTHFRC677Tmutationwas found to be significantly higher in women who experienced pregnancies withNTDs,while occurrence of factor V Leiden andprothrombin gene G20210A mutations were not significantly different between the study and control groups. The frequency of both homozygous and heterozygous MTHFR C677T mutation was 69.0% inwomenwho experienced pregnancies with NTDs (42.9% in the control group). Thepresence ofMTHFRC677Thad an odds ratio of 2.96 (95.0%CI, 1.05–8.32) for the development of NTDs. The frequencies of factor V Leiden, prothrombin geneG20210A, and MTHFR C677T mutations and allele frequencies with statistical comparisons are shown in Table 1. A study by Akar et al. [2] showed no relationship between MTHFR C677T mutation and spina bifida. However, they suggested that coexpression of MTHFR A1298C and MTHFR C677T mutations increased the risk of spina bifida. A similar association for NTD cases was reported in another study [3]. ⁎ Corresponding author. Department of Obstetrics and Gynecology, Gulhane Military Medical Academy, Etlik, 06010 Ankara, Turkey. Tel.: +90 312 3045818; fax: +90 312 3045800. E-mail address: [email protected] (S.T. Ceyhan).