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Öğe Automated Classification of Skin Diseases Using Microscopic Images: A Machine Learning Approach(Wiley, 2025) Karapinar Senturk, Zehra; Guler, Recep; Ozcan, Yunus; Gamsizkan, MehmetThis study presents a machine learning-based approach for the automated classification of skin diseases, specifically targeting morphea and lichen sclerosus, using microscopic images. The proposed method involves a systematic workflow, including image preprocessing techniques such as resizing, Reinhard normalization, Gaussian filtering, and CLAHE histogram equalization to enhance image quality. Feature extraction was performed using Gray-Level Co-occurrence Matrix (GLCM) and histogram-based statistical methods, capturing texture and intensity characteristics of skin tissues. Several classification models, including Support Vector Machine (SVM), Artificial Neural Network (ANN), Decision Tree (DT), Random Forest (RF), K-Nearest Neighbors (K-NN), and Logistic Regression (LR), were evaluated using accuracy, precision, recall, and F1 score, with hyperparameter optimization via grid search. The experimental results revealed that the combined feature set (GLCM + Histogram) achieved the highest performance, with the RF and K-NN models yielding a 100% in all performance metrics, including accuracy, sensitivity, recall, and F1-score. The study introduces a novel approach by examining these two diseases simultaneously, offering a reliable tool to support dermatologists with accurate and quick diagnoses. Future work will focus on expanding the dataset, exploring advanced deep learning techniques, and integrating clinical metadata to enhance model generalizability.Öğe Comment on Mahmood, M.N. Direct Immunofluorescence of Skin and Oral Mucosa: Guidelines for Selecting the Optimum Biopsy Site. Dermatopathology 2024, 11, 52–61(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Demiral, Şebnem; Ozcan, Yunus; Gamsizkan, Mehmet[No abstract available]Öğe Decreased Oxidative Stress Markers in Patients with Active and Generalized Vitiligo(Duzce Univ, Fac Medicine, 2022) Ozcan, Yunus; Karagun, Ebru; Alpay, MerveObjective: Oxidative stress has been shown to play a role in the pathophysiology of several diseases, making it a popular yet contentious research area. There is some evidence that selective melanocyte destruction may have developed in vitiligo patients as a result of elevated oxidative stress. The purpose of this study is to investigate the impact of oxidative stress on lipid, protein, and nucleic acid metabolism in vitiligo patients. Methods: We used ELISA method to measure serum oxidative stress markers in patients with generalized vitiligo who had newly formed lesions in the previous three months but had not been treated, as well as healthy controls. Malondialdehyde (MDA), 2,4-dinitrophenyl hydrazone (DNPH), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and uncoupling protein 2 (UCP2) levels were measured to assess the influence of reactive oxygen derivatives on lipid, protein, nucleic acid metabolism, and mitochondria, respectively. Results: The study included 84 participants, including 64 active generalized vitiligo patients and 20 healthy controls with similar age and gender distribution. In the serum of vitiligo patients, we detected significantly lower levels of MDA (ng/mL, mean +/- SD=12 +/- 19; 33.4 +/- 35.9), DNPH (ng/mL, mean +/- SD=2 +/- 3.1; 6 +/- 7.4), 8-OHdG (ng/mL, mean +/- SD=11.7 +/- 17.9; 32.7 +/- 37) and UCP2 (ng/mL, mean +/- SD=8.7 +/- 13.7; 21.5 +/- 28.4. Conclusions: Although there is significant evidence that oxidative stress plays a role in the pathophysiology of vitiligo, the studies should be interpreted cautiously due to the heterogeneity in the methodology, complexity of the oxidative stress pathways, and potential publication bias. Large-scale studies using a standardized methodology are required to determine how significant oxidative stress is in the core pathophysiology of vitiligo and which pathways it primarily affects.Öğe Dermatoscopic Features of Early Erythema Chronicum Migrans(Croation Dermatovenerological Soc, 2023) Ozcan, Yunus; Takir, Sumeyye Gunes; Karagun, Ebru; Uyar, Belkiz[No abstract available]Öğe Diagnosis of Lichen Sclerosus, Morphea, and Vasculitis Using Deep Learning Techniques on Histopathological Skin Images(Sakarya University, 2025) Güler, Recep; Karapinar Şentürk, Zehra; Gamsizkan, Mehmet; Ozcan, YunusSkin diseases are very common all over the world. The examination can be done by photographing the relevant area or taking a tissue sample to diagnose skin diseases. Examining tissue samples allows examination at the cellular level. This study discussed three skin diseases: lichen sclerosus, morphea, and cutaneous small vessel vasculitis (vasculitis). For this problem, which does not have an open-access dataset in the literature, a dataset consisting of histopathological images belonging to each class was created. Convolutional neural network models were created for this three-class classification problem, and their results were evaluated. In addition, in this problem where it is difficult to obtain sample images, the efficiency of transfer learning methods was evaluated with a limited number of examples. For this purpose, tests were performed with VGG16, ResNet50, InceptionV3, and EfficientNetB4 models, and the results were given. Among all the results, the accuracy value of the VGG16 model was 0.9755 and gave the best result. However, although the accuracy value was quite good, precision, recall, and f1-score metrics values were around 0.65. This shows deficiencies in how often the model correctly predicts the positive class and how well it predicts all positive examples in the dataset. © 2025 Elsevier B.V., All rights reserved.Öğe Novel mutation identified in the DDB2 gene in patients with xeroderma pigmentosum group-E(Wiley, 2020) Karagun, Ebru; Eroz, Recep; Gamsizkan, Mehmet; Baysak, Sevim; Eyup, Yavuz; Ozcan, YunusBackground Xeroderma pigmentosum (XP) is a rare photosensitive syndrome, which is divided into eight complementation groups (XP-A to XP-G and XPV) and characterized by skin cancers diagnosed at early age. A family of seven members (age range between 5 and 47 years) with carriers of the novel nonsense mutation that causes XP-E type were included in the current study. Methods DNA was isolated from peripheral blood samples of the proband, and cancer predisposition genes were sequenced with next-generation sequencing. The demographic features and the laboratory, clinical, and histopathological findings of patients were evaluated. Results In the proband, squamous cell carcinoma was first diagnosed in the right-eye cornea at the age of 13 years and then in the left-eye cornea at the age of 15 years. Later, the patient was diagnosed with basosquamous cell carcinoma on the dorsum of the nose at the age of 18 years. After genetic analysis, a novel nonsense c.1063C>T(p.Arg355Ter) pathogenic variation that causes XP-E type was detected as homozygous in the DDB2 gene of the proband and her siblings, 11 and 5 years of age, and as heterozygous in her parents and a 22-year-old brother. Conclusion Because of the occurrence of early termination codon, truncated nonfunctional proteins or proteins with deleterious loss or gain-of-function activities are synthesized in nonsense mutation. Thus, to avoid the development of pathological lesions, it is important that such patients with nonsense mutation stay away from agents that might cause DNA damage and develop an appropriate lifestyle according to this condition.Öğe Treatment of Burn Wounds with a Chitosan-Based Hydrogel Dressing Containing Artemisia absinthium L.: A Comprehensive In Vivo Study(2024) Aydın, Meryem; Ozcan, Yunus; Kantarcıoglu Coşkun, Sinem; Alpay, Merve; Coskun, Nuri CenkObjective: Wormwood (Artemisia absinthium L.) is a valuable medicinal plant that has been used for the wound healing since ancient times. Hydrogel dressings are often preferred for wound care in treatment. In this study, the effects of chitosan-based hydrogel dressings containing wormwood were investigated in rats with a burn wound model for the first time. Material-Method: Certain phenolic compounds in wormwood extracts were detected by LC-MS/MS and antioxidant activities were calculated using the DPPH. The antibacterial activity of the dressings was tested using the disk diffusion method. Tissues taken from 48 female Sprague-Dawley rats were histopathologically examined at days 3rd and 21st. Skin tissue Il-1?, Il-6, TNF-? and Il-10 levels were measured using ELISA. All data obtained from histopathological examination and cytokine levels were statistically evaluated. Results: Fifteen phenolic compounds were quantitatively determined in wormwood extracts. The antioxidant activities of high-, medium-, and low-dose wormwood extracts were 91.1% ± 0.054, 89.6% ± 0.012 and 84.1% ± 0.02, respectively. The hydrogel dressings showed no antibacterial activity against S. aureus (ATCC 29213) or P. aeruginosa (ATCC 27853). Granulation tissue formation, collagen increase, and regular scar appearance were higher in all three wormwood groups. Wound contraction was completed and remodeling phase started at day 21st, especially in the high-dose wormwood treatment group. Tissue cytokine levels were determined in pg/ml in all groups. Conclusion: It was determined that A. absinthium L. can promote wound healing through various mechanisms of action and shows immunomodulatory effects, and is appropriate for use as a wound dressing in the form of a chitosan-based hydrogel.
