Researcher:
Baysal, Kemal

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Kemal

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Baysal

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Baysal, Kemal

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2019 - 201922020 - 202211

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Now showing 1 - 10 of 13
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    Expressions of dna base excision genes in unipolar and bipolar depression
    (2022) Yılmaz, Selda; Akan, Pınar; Özerdem, Ayşegül; N/A; Ceylan, Deniz; Baysal, Kemal; Faculty Member; Faculty Member; School of Medicine; School of Medicine; 137755; 119184
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    The effect of antioxidant culture conditions and isolation methods in obtaining mesenchymal stem cells from the wharton’s jelly of human umbilical cord
    (Dokuz Eylül Üniversitesi Tıp Fakültesi, 2021) Şan, Tuğba; Bora, Uğur; Sayın, Özge; Güneş, Mehmet Emin; Öztekin, Deniz; Ergür, Bekir Uğur; Akan, Pınar; N/A; Baysal, Kemal; Faculty Member; School of Medicine; 119184
    Objective: Obtaining and growing human stem cells are the first stages of regenerative medicine applications. During cell proliferation for therapeutic purposes, mesenchymal stem cells (MSCs) rapidly undergo premature aging, possibly involving oxidative stress. Bone marrow MSCs (BM-MSCs) are the most clinically used cells. It is suggested that Wharton-jelly MSCs (WJ-MSCs) located around the umbilical cord may be more useful than BM-MSCs due to non-invasive acquisition, lack of expression of proteins which cause tissue rejection, and their immunosuppressive properties. It was aimed to compare the efficiency of the isolation methods used in the reproduction of WJ-MSCs and to determine the effect of anti-oxidative culture conditions on cell viability and expression of cell-surface antigens. Materials and Methods: Postnatal cord samples were obtained from 17 healthy pregnant women who met the inclusion criteria. Stem cells were obtained from Wharton jelly using enzymatic and explant methods and cell viability and proliferation capacities were compared. Results: The differentiation capacity of stem cells into osteoblasts, chondrocytes and adipocytes was demonstrated immunohistochemically. The expression of CD44, CD73, CD90, CD105 surface antigens remained unchanged until the fourth passage during the proliferation process. The effect of culture conditions achieved by addition of anti-oxidant molecules N-acetyl cysteine and ascorbic acid on cell viability and cell surface antigen expressions were demonstrated. Conclusion: The explant method in the isolation of MSCs from Wharton jelly was more advantageous than the enzymatic method due to the total number of cells obtained in a shorter time period, without significantly changing the surface antigen expressions. / Amaç: Günümüzde, insan kök hücrelerin eldesi ve kültür ortamında çoğaltılması rejeneratif tıp uygulamalarının ilk aşamalarından biridir. Terapötik amaçlar için in vitro hücre çoğaltmada, mezenkimal kök hücreleri (MKH)’ nin muhtemelen oksidatif stresi içeren erken yaşlanmaya hızla girmeleri önemli bir sorundur. Klinikte tedavide en yaygın kullanılan hücreler, kemik iliği MKH (Kİ-MKH) olmakla birlikte, göbek kordonu çevresinde yer alan Wharton jölesi MKH (WJ-MKH)’ nin invaziv olmayan şekilde elde edilebilmeleri, doku reddine yol açan proteinleri eksprese etmemeleri ve immünosupresif özellikleri nedeni ile Kİ-MKH’ nden daha kullanışlı olabilecekleri ileri sürülmektedir. Çalışmamız ile WJ-MKH’nin eldesi ve çoğaltılmasında kullanılan izolasyon yöntemlerinin etkinliğinin karşılaştırılması ve anti-oksidatif kültür koşullarının hücre canlılığı ve kök hücrelere özgü yüzey antijen ekspresyonlarına etkisinin belirlenmesi amaçlandı. Gereç ve Yöntem: Çalışmaya dahil etme kriterlerine uyan toplam 17 sağlıklı gebeden doğum sonrası kordon örnekleri alındı. Wharton jölesinden enzimatik ve eksplant yöntemi ile kök hücreler elde edilerek, hücre canlılıkları ve proliferasyon kapasiteleri karşılaştırıldı. Bulgular: Kök hücrelerin, osteoblastlara, kondrositlere ve adipositlere farklılaşma kapasiteleri immunohistokimyasal olarak gösterildi. Hücrelerin çoğaltılması sürecinde CD44, CD73, CD90, CD105 yüzey antijenlerinin dördüncü pasaja kadar anlamlı değişmeden eksprese edildiği saptandı. Antioksidan moleküller N-asetil sistein ve askorbik asit ilavesi ile sağlanan kültür koşullarının hücre canlılığı ve hücre yüzey antijen ekspresyonları üzerine etkisi gösterildi. Sonuç: Wharton jölesinden MKH’lerin izolasyonunda eksplant yönteminin yüzey antijen ifadeleri anlamlı değişmeksizin, daha kısa zaman diliminde elde edilen toplam hücre sayısı nedeni ile enzimatik yönteme göre daha avantajlı olduğu sonucuna varıldı.
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    Assessment of inflammatory markers in microvascular angina
    (Elsevier Ireland Ltd, 2019) Polat, V.; Şahin, M. H.; Aslan, Gamze; Polat, Evin Bozçalı; Ural, Dilek; Baysal, Kemal; Doctor; Doctor; Faculty Member; Faculty Member; N/A; N/A; School of Medicine; School of Medicine; Koç University Hospital; N/A; 239008; 1057; 119184
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    The effects of pre-pregnancy obesity and gestational weight gain on maternal lipid profiles, fatty acids and insulin resistance
    (De Gruyter, 2021) Onem, Muge Gul Gulecoglu; Coker, Canan; Altunyurt, Sabahattin; Keskinoglu, Pembe; N/A; Baysal, Kemal; Faculty Member; School of Medicine; 119184
    Objectives: Pregnancy is associated with physiological alterations in insulin sensitivity and lipid metabolism. This study investigates the associations between pregestational body mass index (pBMI) and the rate of gestational weight gain (rGWG) in the second trimester with the biomarkers of lipid, fatty acids metabolism and insulin resistance. Methods: Sixty nine pregnantwomen followed. The body weights of the pregnant women weremeasured and blood samples were obtained at 11-14th and 24-28th weeks of pregnancy. Glucose, total cholesterol, triglyceride, HDL cholesterol, LDL cholesterol, insulin levels and fatty acids were measured. Rate of GWG (kg/week) and The Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) were calculated. The pregnant women were stratified according to their pBMI and the 2nd trimester rGWG. Results: The rate of GWG was significantly higher for the group with pBMI<25, compared to the group with pBMI=25 (p=0.024). Triglyceride, total cholesterol, LDL and HDL cholesterol were significantly increased in the second trimester compared with the first trimester. Palmitic acid, oleic acid, linoleic acid, myristic acid, docosahexaenoic acid (DHA), arachidonic acid (AA), total omega-6 (n - 6) and omega-3 (n - 3) fatty acid levels and n - 6/n - 3 ratio were significantly higher in the second trimester. Glucose was significantly decreased and insulin was increased in the second trimester. In the overweight/obese group; HOMA-IR, insulin, AA, palmitoleic acid and stearic acid were found to be high in comparison to the group with low/ normal pBMI. No parameters were associated with rGWG. Conclusions: The changes in lipid parameters, free fatty acids, insulin and HOMA-IR in the second trimester were compatible with the changes in lipid metabolism and the development of insulin resistance. Pregestational BMI was shown to have a stronger influence on lipid profile, insulin resistance, and fatty acids than rGWG.
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    Impact of gender and diabetes on the relationship between lipoprotein (a) and coronary artery disease
    (Elsevier Ireland Ltd, 2021) Yurtseven, Ece; Ural, Dilek; Cünedioğlu, Berkay Ömer; Gürsoy, Erol; Güler, Orhan Ulaş; Aytekin, Saide; Aytekin, Vedat; Baysal, Kemal; Teaching Faculty; Faculty Member; Undergraduate Student; Doctor; Undergraduate Student; Doctor; Faculty Member; Faculty Member; School of Medicine; School of Medicine; School of Medicine; N/A; School of Medicine; N/A; School of Medicine; School of Medicine; 176021; 1057; N/A; N/A; N/A; N/A; 140946; 119184
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    Relationship between lipoprotein (a) and coronary artery disease in patients with very high ldl level
    (Elsevier Ireland Ltd, 2022) Yurtseven, Ece; Ural, Dilek; Cünedioğlu, Berkay Ömer; Gürsoy, Erol; Aytekin, Saide; Aytekin, Vedat; Baysal, Kemal; Teaching Faculty; Faculty Member; Undergraduate Student; Doctor; Doctor; Faculty Member; Faculty Member; School of Medicine; School of Medicine; School of Medicine; N/A; N/A; School of Medicine; School of Medicine; 176021; 1057; N/A; N/A; N/A; 140946; 119184
    Background and Aims : Adults who have low density lipoprotein (LDL) cholesterol levels of more than 190 mg/dl are classified in very high-risk group for major cardiovascular events. The data about the impact of Lp(a) on coronary artery disease (CAD) in patients with very high LDL levels is insufficient. We aimed to investigate the relationship of Lp(a) level with CAD in patients with very high LDL levels. Methods: We retrospectively analyzed the data of 247 patients whose LDL levels were equal to or higher than 190mg/dl and who had Lp(a) measurements. Lipid profile, co-morbidities, cardiovascular diseases, blood pressure, body mass index, eGFR and smoking status were assessed. The relationship between Lp(a) levels and CAD was analyzed. Results: A total of 247 patients whose 50.4% were female, 22.6% diabetic and 36.7% hypertensive, 19% had coronary artery disease were included in the analysis. Patients with CAD had higher levels of Lp (a) (median 16 mg/dl vs 23 mg/dl p= 0.024). Age [odds ratio (OR), 1.060; 95% confidence interval (CI): 1.020-1.101; p = 0.003], sex (OR, 6.29; 95% CI:2.604-15.198; p = 0.000) and Lp(a) level (OR, 1.011; 95% CI: 1.001-1.021; p = 0.035) were independently related with CAD. ROC curve analyses demonstrated that Lp(a) level of 19.5mg/dl was the cut-off value for CAD in patients with very high LDL level (AUC:0.6, p=0.023). Conclusions: In our study, we found increased Lp(a) level as a risk factor for CAD in patients with very high LDL levels. Furthermore, our results demonstrate that Lp(a) is the independent predictor of CAD in this patient group.
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    Machine learning-based approach to identify formalin-fixed paraffin-embedded glioblastoma and healthy brain tissues
    (Spie-Int Soc Optical Engineering, 2022) N/A; Department of Electrical and Electronics Engineering; N/A; N/A; N/A; N/A; N/A; Department of Electrical and Electronics Engineering; Torun, Hülya; Batur, Numan; Bilgin, Buse; Esengür, Ömer Tarık; Baysal, Kemal; Kulaç, İbrahim; Solaroğlu, İhsan; Onbaşlı, Mehmet Cengiz; PhD Student; Undergraduate Student; PhD Student; Undergraduate Student; Faculty Member; Faculty Member; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; Graduate School of Sciences and Engineering; School of Medicine; School of Medicine; School of Medicine; School of Medicine; College of Engineering; N/A; N/A; N/A; N/A; 119184; 170305; 102059; 258783
    Glioblastoma is the most malignant and common high-grade brain tumor with a 14-month overall survival length. According to recent World Health Organization Central Nervous System tumor classification (2021), the diagnosis of glioblastoma requires extensive molecular genetic tests in addition to the traditional histopathological analysis of Formalin-Fixed Paraffin-Embedded (FFPE) tissues. Time-consuming and expensive molecular tests as well as the need for clinical neuropathology expertise are the challenges in the diagnosis of glioblastoma. Hence, an automated and rapid analytical detection technique for identifying brain tumors from healthy tissues is needed to aid pathologists in achieving an error-free diagnosis of glioblastoma in clinics. Here, we report on our clinical test results of Raman spectroscopy and machine learning-based glioblastoma identification methodology for a cohort of 20 glioblastoma and 18 white matter tissue samples. We used Raman spectroscopy to distinguish FFPE glioblastoma and white matter tissues applying our previously reported protocols about optimized FFPE sample preparation and Raman measurement parameters. One may analyze the composition and identify the subtype of brain tumors using Raman spectroscopy since this technique yields detailed molecule-specific information from tissues. We measured and classified the Raman spectra of neoplastic and non-neoplastic tissue sections using machine learning classifiers including support vector machine and random forest with 86.6% and 83.3% accuracies, respectively. These proof-of-concept results demonstrate that this technique might be eventually used in the clinics to assist pathologists once validated with a larger and more diverse glioblastoma cohort and improved detection accuracies.
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    Gender difference in the relation of serum lipoprotein (a) to reduced renal function in diabetic and non-diabetic patients
    (Elsevier, 2021) Aytekin, Saide; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; Ural, Dilek; Yurtseven, Ece; Cünedioğlu, Berkay Ömer; Güler, Orhan Ulaş; Aytekin, Saide; Aytekin, Vedat; Baysal, Kemal; Faculty Member; Teaching Faculty; Undergraduate Student; N/A; Undergraduate Student; NA; Faculty Member; Faculty Member; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; N/A; School of Medicine; School of Medicine; 1057; 176021; N/A; N/A; N/A; N/A; 140946; 119184
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    Genetic algorithm-driven design of SERS-active surfaces for early detection of diseases
    (Spie-Int Soc Optical Engineering, 2020) N/A; Department of Electrical and Electronics Engineering; N/A; N/A; Department of Electrical and Electronics Engineering; Bilgin, Buse; Türkmen, Berkay; Baysal, Kemal; Solaroğlu, İhsan; Onbaşlı, Mehmet Cengiz; PhD Student; Undergraduate Student; Faculty Member; Faculty Member; Faculty Member; Department of Electrical and Electronics Engineering; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); Koç University Tüpraş Energy Center (KUTEM) / Koç Üniversitesi Tüpraş Enerji Merkezi (KÜTEM); Graduate School of Sciences and Engineering; College of Engineering; School of Medicine; School of Medicine; College of Engineering; N/A; N/A; 119184; 102059; 258783
    Surface-enhanced Raman spectroscopy (SERS) enables the surface plasmon-based amplification and detection of Raman signals from biomarkers, which emerge at ultralow concentrations in the early phases of diseases. Thus, SERS chips could be used for early detection of diseases from their biomarkers obtained from liquid or tissue biopsies. While this surface enhancement capability of nanoscale gold or silver layers on different substrates were demonstrated in previous experiments and electromagnetic models, the position of the biomarker molecules on the SERS chips cannot be known or estimated a priori. As a result, SERS chips must be designed over millimeter-scale areas such that the signal amplification must be large (10(6) times or higher with respect to no SERS) and must span the entire slide. Simultaneous surface-enhancement of Raman signals and distributing this enhancement factor (EF) over the sample surface requires an iterative and \learning" design procedure for the geometries of nanoscale metallic features that could maximize both EF and its area simultaneously. In this study, we develop genetic algorithms and use finite-difference time-domain (FDTD) modeling to optimize the geometry of gold nanostructures (NS) on glass microscope slides to functionalize these slides as SERS-active surfaces for SERS-based enhancement of Raman spectra. By using FDTD models, we calculated the enhancement factors in 3D on glass surface for 785 nm laser for Raman spectrum measurements and used genetic algorithms (GA) to iterate on the metal NS geometry to maximize the average and the hot spot EF over the periodic patterns on the slide. Field enhancement factors as high as 10(17) and 10(15) were calculated for hot-spots and for whole-slide averages, respectively. The optimized structures indicate that GA could help maximize label-free and whole-slide Raman signal enhancement factors for single-cell SERS detection.
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    Alterations in expressions of DNA base excision repair (BER) genes in unipolar and bipolar depression
    (N/A, 2022) Yılmaz, Selda; Akan, Pınar; Özerdem, Ayşegül; N/A; Ceylan, Deniz; Baysal, Kemal; Faculty Member; Faculty Member; School of Medicine; School of Medicine; 137755; 119184
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