Browsing by Author "Şimşek F."

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    A new approach for determining the spatial risk levels for visceral and cutaneous leishmaniasis related with the distribution of vector species in western part of turkey using geographical information systems and remote sensing; [Coğrafi bilgi sistemleri ve uzaktan algılama kullanılarak türkiye’nin batısında visseral ve kutanöz leishmaniasisde vektör türlerin dağılımı ile ilişkili mekansal risk düzeylerinin saptanması için yeni bir yaklaşım]
    (Veteriner Fakultesi Dergisi, 2012) Ölgen M.K.; Özbel Y.; Balcioğlu I.C.; Demir S.; Şimşek F.; Özensoy Töz S.; Ertabaklar H.; Alkan M.Z.
    Leishmaniases are present in two clinical forms, as visceral and cutaneous, in Turkey showing a tendency of spreading throughout the country. The aim of the present study was to produce a new model for determining the spatial risk levels using the data in a selected study site in the western part of Turkey. The results of entomological studies in this leishmaniasis focus indicated the presence of suspected vector species Phlebotomus (Larroussius) tobbi and P. (Larroussius) neglectus for the visceral, P. (Paraphlebotomus) similis for cutaneous forms of the disease. The new risk model was developed based on univariate and multivariate binary logistic regression analyses of geographical variables as altitude, aspect, Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI) and Land Surface Temperature (LST) values related to the distribution of these three species. The results of the new model were used to produce the risk maps and the potential distribution areas of the incriminated vector species with the use of geographical technologies which allowed the identification of the leishmaniasis risk levels that may provide useful information to guide the control program interventions. © 2012, Veteriner Fakultesi Dergisi. All rights reserved.
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    A comparison of the molecular distribution of proangiogenic factors in endometrium of missed abortions and of voluntary first trimester termination cases
    (S.O.G. CANADA Inc., 2015) Özçakir T.; Turan M.A.; Şimşek F.; Atay C.; Vatansever S.; Özbilgin K.
    Objective: The authors aimed to evaluate the angiogenic changes that occur in the cases with missed abortions compared with the voluntary termination of pregnancy as control group, with this controlled clinical study. Materials and Methods: The study included fifteen healthy volunteer women with unwanted pregnancy less than 10th gestational week in an academic research environment. The patients were 19 women between 6th and 11th gestational weeks diagnosed with missed abortion as the patient group. Immunohistochemistry was utilized to examine temporal and spatial expression of vascular endothelial growth factor (VEGF) and their two receptors: VEGF-R1 (Flt-1) and VEGF-R2 (Flk-l/KDR), and Trombospondin-1, eNOS, iNOS, and HIF-la in the both deciduas and placenta of the both groups. Results: This study discovered the significant difference (p < 0.005) between the groups of controlled and missed abortion in the decidual and placental cell components, and has put forward that thrombospondin and iNOS have an impact on abortion through antiangiogenic effect in cases of missed abortions. Conclusions: The potential role of molecules affecting angiogenesis in the etiology of missed abortion has been evaluated and the authors aimed for this to be a guide for studies on further treatments and on the prevention of the development of missed abortions.
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    Prognostic Factors in High Grade Osteosarcoma Patients Who Received Neoadjuvant Therapy and Subsequently Underwent Surgery: Data from the Turkish Oncology Group
    (Multidisciplinary Digital Publishing Institute (MDPI), 2025) Sever N.; Şimşek F.; Onur İ.D.; Arvas H.; Guliyev T.; Şakalar T.; Çiçek C.M.; Orman S.; Çetin E.B.; Kayaş K.; Akbaş S.; Ağyol Y.; Güren A.K.; Erel P.; Kocaaslan E.; Paçacı B.; Tunç M.A.; Çelebi A.; Majidova N.; Durnalı A.; Şimşek M.; Şahbazlar M.; Işık S.; Arıkan R.; Ercelep Ö.; Sarı M.; Köstek O.; Bayoğu İ.V.
    Background: Osteosarcoma is a rare but aggressive bone malignancy. Despite advances in multimodal therapy, survival remains suboptimal, highlighting the need for prognostic markers to guide treatment. Methods: This study included 162 osteosarcoma patients who received neoadjuvant chemotherapy followed by surgery between January 2009 and March 2024. Patients received either double (cisplatin + doxorubicin) or triple (MAP or PEI) chemotherapy. Survival analyses were conducted using Kaplan–Meier curves, log-rank tests, and Cox proportional hazards models. Results: The median age was 20 years (IQR: 18–29), and 53.1% were male. Patients who received triple chemotherapy regimens demonstrated significantly longer overall survival (OS) compared to those on doublet regimens. High tumor necrosis rates (>90%) and negative surgical margins were strongly associated with improved OS, while metastatic disease at diagnosis, elevated alkaline phosphatase (ALP), and male gender were linked to poorer survival. Multivariate analysis identified adjuvant therapy, age under 18, high necrosis rate, negative margins, and normal ALP as significant OS predictors. Conclusions: Triple-agent chemotherapy, necrosis rate ≥90 and negative surgical margins are strongly associated with prolonged survival in osteosarcoma. The key prognostic indicators such as ALP levels, surgical margins and age at diagnosis should guide personalized treatment strategies to improve outcomes in curable patients. © 2025 by the authors.