Browsing by Author "Vural, B."

Now showing 1 - 9 of 9

Open Access
Ant i-neuronal and stress-induced-phosphoprotein 1 antibodies in neuro-Behcet's disease
(Elsevier, 2011-10-28) Vural, B.; Uğurel, E.; Tüzün, E.; Kürtüncü, M.; Zuliani, L.; Çavus, F.; İçoz, S.; Erdağ, E.; Gül, A.; Güre, A. O.; Vincent, A.; Özbek, U.; Eraksoy, M.; Demir, G. A.
No disease-specific neuronal antibodies have so far been defined in neuro-Behçet's disease (NBD). Immunohistochemistry and immunocytochemistry studies showed antibodies to hippocampal and cerebellar molecular layers and the surface antigens of cultured hippocampal neurons in sera and/or cerebrospinal fluids (CSF) of 13 of 20 NBD and 6 of 20 BD patients but not in multiple sclerosis or headache controls. Screening with a protein macroarray led to identification of stress-induced-phosphoprotein-1 (STIP-1) as an antigenic target. High-titer STIP-1-antibodies were detected in 6 NBD patients' sera but not in controls. These results suggest that neuronal antibodies could be useful as diagnostic biomarkers in NBD. © 2011 Elsevier B.V.
Open Access
Autologous anti-SOX2 antibody responses reflect intensity but not frequency of antigen expression in small cell lung cancer
(BioMed Central Ltd., 2014) Atakan, S.; Bayiz, H.; Sak, S.; Poyraz, A.; Vural, B.; Yildirim, A. S.; Demirag, F.; Gure, A. O.
Background: Anti-SOX2 antibody responses are observed in about 10 to 20% of small cell lung cancer (SCLC) patients. The aim of this study was to determine whether such responses reflect a particular pattern of SOX2 protein expression in the tumor and whether this pattern associates with clinical outcome. Methods. Paraffin embedded tumor tissues, obtained from SCLC patients who had no evidence of paraneoplastic autoimmune degeneration, were evaluated for SOX2 expression by immunohistochemistry for both intensity and extent of staining. Sera from the same patients were tested for autologous antibodies against recombinant SOX2 by enzyme-linked immunosorbent assay (ELISA). Correlates between overall survival and various clinical parameters including SOX2 staining and serology were determined. Results: SOX2 protein expression was observed in tumor tissue in 89% of patients. Seventeen patients (29%) were seropositive for SOX2 antibodies and, in contrast to SOX2 staining, the presence of antibody correlated with limited disease stage (p = 0.05). SOX2 seropositivity showed a significant association with the intensity of SOX2 staining in the tumor (p = 0.02) but not with the frequency of SOX2 expressing cells. Conclusion: Anti-SOX2 antibodies associate with better prognosis (limited stage disease) while SOX2 protein expression does not; similar to reports from some earlier studies. Our data provides an explanation for this seemingly contrasting data for the first time as SOX2 antibodies can be observed in patients whose tumors contain relatively few but strongly staining cells, thus supporting the possible presence of active immune-surveillance and immune-editing targeting SOX2 protein in this tumor type. © 2014 Atakan et al.; licensee BioMed Central Ltd.
Open Access
The effect of world income on the economic performance of African countries
(International Economic Society, 2007) Berument, Hakan; Ceylan, N. B.; Vural, B.
This paper examines how the output growths of 37 African countries’ are affected by the output growth of the world. The connection between the world output growth and that of each African country is represented by a block recursive VAR model allowing that world output growth affects each African countries’ output but not vice versa. The response of each African country’s output growth is analyzed when one standard deviation shock is given to the world’s output growth. Our results indicate that in 6 of the 37 countries, there exists a statistically significant and permanent effect for four periods (years), and the effect is positive for 5 of them. The statistically significant effect of the shock is observed starting from the first period for 16 countries, of which the effect is positive in 13. The initial (contemporaneous) effect of the shock can be observed in the output growths of 13 African countries of which the effect is positive in 9. For the output growths of 9 countries, a statistically significant effect could not be observed.
Open Access
The effects of Japanese economic performance on Indonesia
(Routledge, 2006) Berument, Hakan; Ceylan, N. B.; Vural, B.
This paper assesses how Japanese economic performance affects the Indonesian economy for the 1988 to 2004 period. The empirical evidence provided here suggests that Japanese growth appreciates the local currency in real terms, decreases the inflation and increases growth. As a side issue, we also documented that real exchange rate depreciation accelerates inflation and decreases growth in Indonesia. © 2006 Taylor & Francis.
Open Access
Evaluation of chimerism with DNA polymorphisms in bone marrow transplantation
(International Children's Center (I C C), 1997) Özbek, U.; Vural, B.; Kalayoǧlu, S.; Soysal, T.; Bilgen, H.; Yavuz, S.; Anak, S.; Sargın, D.; Gedikoǧlu G.; Ferhanoǧlu, Burhan; Akoǧlu, T.; Tangün, Y.; Özçelik, Tayfun
Evaluation of chimeric status following allogenlc BMT is an Important tool for monitoring the replacement of host cells with donor cells and for determining the risk of relapse. Polymorphic DNA sequences can be used as powerful markers in identification of donor/recipient genotype differences, even between close relatives. Polymerase chain reaction (PCR) amplification of three variable number of tandem repeat (VNTR) loci and five single-locus polymorphisms (SLP) was used to identify chimerism in 40 recipient-donor pairs. Mixed chimerism was present in 11 patients, and complete chimerism in 29. This PCR method is a rapid and sensitive assay to detect engraftment and evaluate relapse potential, and thus is very useful in the clinical management of BMT patients.
Open Access
Mitochondrial carrier homolog 1 (Mtch1) antibodies in neuro-Behçet's disease
(Elsevier, 2013) Vural, B.; Şehitoğlu, E.; Çavuş, F.; Yalçınkaya, N.; Haytural, H.; Küçükerden, M.; Ulusoy, C.; Uğurel, E.; Turan, S.; Bulut, L.; Türkoğlu, R.; Shugaiv, E.; Kürtüncü, M.; Atakan, S.; Güre, A. O.; Gül, A.; Eraksoy, M.; Demir, G. A.; Tüzün, E.
Efforts for the identification of diagnostic autoantibodies for neuro-Behcet's disease (NBD) have failed. Screening of NBD patients' sera with protein macroarray identified mitochondrial carrier homolog 1 (Mtch1), an apoptosis-related protein, as a potential autoantigen. ELISA studies showed serum Mtch1 antibodies in 68 of 144 BD patients with or without neurological involvement and in 4 of 168 controls corresponding to a sensitivity of 47.2% and specificity of 97.6%. Mtch1 antibody positive NBD patients had more attacks, increased disability and lower serum nucleosome levels. Mtch1 antibody might be involved in pathogenic mechanisms of NBD rather than being a coincidental byproduct of autoinflammation. © 2013 Elsevier B.V.
Open Access
A novel 20-gene prognostic score in pancreatic adenocarcinoma
(Public Library of Science, 2020) Demirkol-Canlı, S.; Dedeoğlu, Ege; Akbar, Muhammad Waqas; Küçükkaraduman, Barış; İşbilen, Murat; Şükrüoğlu-Erdoğan, Ö.; Kılıç-Erciyas, S.; Yazıcı, H.; Vural, B.; Güre, Ali Osmay
Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal cancers. Known risk factors for this disease are currently insufficient in predicting mortality. In order to better prognosticate patients with PDAC, we identified 20 genes by utilizing publically available high-throughput transcriptomic data from GEO, TCGA and ICGC which are associated with overall survival and event-free survival. A score generated based on the expression matrix of these genes was validated in two independent cohorts. We find that this “Pancreatic cancer prognostic score 20 –PPS20” is independent of the confounding factors in multivariate analyses, is dramatically elevated in metastatic tissue compared to primary tumor, and is higher in primary tumors compared to normal pancreatic tissue. Transcriptomic analyses show that tumors with low PPS20 have overall more immune cell infiltration and a higher CD8 T cell/Treg ratio when compared to those with high PPS20. Analyses of proteomic data from TCGA PAAD indicated higher levels of Cyclin B1, RAD51, EGFR and a lower E-cadherin/Fibronectin ratio in tumors with high PPS20. The PPS20 score defines not only prognostic and biological sub-groups but can predict response to targeted therapy as well. Overall, PPS20 is a stronger and more robust transcriptomic signature when compared to similar, previously published gene lists.
Open Access
Seroreactivity against PTEN-induced putative kinase 1 (PINK1) in Turkish patients with Behçet's disease
(Pacini Editore SpA, 2009) Vural, B.; Demirkan, A.; Ugurel, E.; Kalaylioglu-Wheeler, Z.; Esen, B. A.; Gure, A. O.; Gül, A.; Ozbek, U.
Background. Behçet’s disease (BD) is a multisystem inflammatory disorder characterized by recurrent oral ulcers, genital ulcers and ocular inflammation, as well as skin, joint, vascular, pulmonary, central nervous system (CNS) and gastrointestinal tract manifestations. The etiopathogenesis of BD has not yet been identified; but it has generally been accepted that several environmental factors may induce an inflammatory attack in genetically susceptible individuals. In this study, we aimed to identify antigens that could elicit high-titer IgG responses by the serological analysis of recombinant expression of cDNA libraries method (SEREX).
Open Access
Turkish population data on the HLA-DQα, LDLR, GYPA, HBGG, D7S8, and GC loci
(Springer, 1998) Vural, B.; Atlioǧlu, E.; Kolusayin, Ö.; Togan, I.; Büyükdevrim, S.; Özçelik, T.
We have determined the allele and genotype frequencies of six PCR-based genetic markers HLA-DQα, LDLR, GYPA, HBGG, D7S8 and GC in the Turkish population (n = 361 for HLA-DQα, and n = 260 for PM). All loci meet Hardy- Weinberg expectations. The frequency data can be used in forensic analyses in the Turkish population.