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    An in vitro pilot study investigating placenta-derived mesenchymal stem cell coating on polypropylene mesh materials
    (Springer London Ltd, 2024) Aslan, Erdogan; Maytalman, Erkan; Samur, Dilara Nemutlu; Kole, Emre; Gunizi, Ozlem Ceren
    Introduction and hypothesis: Polypropylene meshes (PM) used in pelvic organ prolapse surgery are being withdrawn from the market. Although concerns about the usage of PMs in stress incontinence surgery have been raised, it is still one of the best methods of curing stress urinary incontinence. With advancements in stem cell-based therapies, especially mesenchymal stem cells (MSCs), it is believed that coating the synthetic meshes with MSCs may minimize excessive tissue reactions ultimately leading to clinical problems such as pain, erosion or extrusion of the implanted material. In our study we tried to show the possibility of coating the PM with placenta-derived MSCs.Methods: Mesenchymal stem cells obtained from six placentas were isolated, cultured, and identified. MSCs were then soaked in either fibronectin or collagen prior to co-culturing with strips of PMs. One group is used as a control, and hence was not pretreated before co-culturing. Specimens were fixed and stained with both Gram and hematoxylin and eosin and marked with Vybran Dil and DAPI. All preparations were examined under a light microscope. The IMAGEJ program was utilized to determine the surface area of meshes coated with MSCs.Results: We clearly showed that PMs can be coated successfully with placenta-derived MSCs. The percentage of the coated area is significantly increased when meshes were pretreated with fibronectin or collagen (p<0.0001).Conclusions: Placenta-derived MSCs can successfully coat PMs. The immunomodulatory properties of MSCs, which may be of great advantage in preventing the side effects of meshes, should be tested by in vivo and hopefully human studies before clinical applications.
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    Comparative Analysis of Vision Transformers and Morphological Approaches for Ki-67 Index Estimation on Histopathologic Images: An Experimental Evaluation
    (Ieee, 2024) Akdeniz, Ahmet Sezer; Ozgur, Berkan; Sahin, Emre; Karadag, Ozge Oztimur; Gunizi, Ozlem Ceren
    This research comprehensively compares two different methodologies for predicting the Ki-67 index- morphological-based analysis and Vision Transformers (ViT). The morphological method focuses on the shape and structural features of tissues and cell structures. On the other hand, Vision Transformers represents an innovative approach developed through the use of attention mechanisms and transformer architectures. ViT offers a different perspective by modeling global context information in recognizing image patterns. This analysis provides a deeper understanding of the accuracy, efficiency, and applicability of current techniques in histopathological image processing, highlighting the potential to advance existing methodologies used in cancer diagnosis. This comparative study aims to evaluate the performance differences between morphological analyses and transformer-based models, identifying the most effective and reliable methods for predicting the Ki-67 index. Experimental analysis, revealed that due to the limited number of labeled data on this domain, traditional morphologic approaches are currently more promising than the vision transformers.
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    Evaluation of the Presence and Importance of PD-L1 Expression in Head-neck Squamosus Cell Carcinomas and Premalign Lesions
    (Dubai Iranian Hosp, 2023) Gunizi, Ozlem Ceren; Gunizi, Huseyin
    Background: Programmed Death-Ligand 1 (PD-L1) is a cell membrane protein found on the surface of cancer cells, immune system cells in the tumor microenvironment, and various healthy tissues. Moreover, it plays a key role in suppressing the immune system. Objectives: We aim to explain the presence of PD-L1 in Head-Neck Squamosus Cell Carcinomas (HNSCC) and premalign lesions by immunohistochemical method. Methods: Our retrospective study included 22 patients with HNSCC (15(68.1%) Oral cavity and 7(31.9%) Oropharynx), 20 patients with oral lichen planus, and 14 patients with normal oral cavity mucosa. In the evaluation of PD-L1 antibodies applied immunohistochemically in patients with HNSCC, the percentage of tumor cells showing membranous staining with PD-L1 antibodies was calculated. Results: The mean age of HNSCC patients participating in the study was 52.24 +/- 11.7 years, the mean age of oral lichen planus patients was 34.10 +/- 9.8 years, and the control patients' mean age was 31.42 +/- 10.6 years. The rate of PD-L1 staining of tumor cells of HNSCC patients was significantly higher than the control group (P=0.001). Conclusion: The importance of PD-L1 expression in HNSCC and precancerous lesions of the oral cavity is remarkable, and the values may be related to the pathophysiology of these diseases.
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    Investigation of the Proapoptotic Effects of Cetixumab and Selenium Combination on Laryngeal Cancer Cells via TRPM2 Channels
    (Dubai Iranian Hosp, 2025) Gunizi, Huseyin; Gunizi, Ozlem Ceren; Ovey, Shak Suat
    Background and Objectives: Cetuximab is commonly used as a chemotherapy drug for treating laryngeal cancer. Selenium, known for its antioxidant properties, is also believed to enhance the effectiveness of certain chemotherapeutic agents. This study aimed to evaluate how cetuximab and selenium influence the activation of the Transient Receptor Potential Melastatin 2 (TRPM2) channel. Methods: An observational study was conducted using cultured human laryngeal cancer cells (Hep-2). The cells were divided into seven experimental groups. Cumene hydroperoxide was used to stimulate the cells and activate TRPM2 channels, while antranilic acid was applied in certain groups to inhibit these channels. Measurements included cytosolic calcium levels, apoptosis, intracellular reactive oxygen species (ROS), mitochondrial depolarization, caspase-3 and caspase-9 activities, as well as immunohistochemical (IHC) staining. Statistical analysis was performed using GraphPad Prism 7.04, and data are presented as mean +/- standard deviation. Results: Compared to the cetuximab-only group, cells treated with both cetuximab and selenium showed significantly higher levels of apoptosis, intracellular calcium, ROS, and caspase-3 and caspase-9 activities (P<0.001). Inhibition of TRPM2 channels by antranilic acid significantly reduced apoptosis in these groups (P<0.05 and P<0.001). Conclusion: The pro-apoptotic effect of cetuximab on laryngeal cancer cells appears to be mediated through TRPM2 channels. Selenium enhances this apoptotic response by promoting TRPM2 channel activation and increasing calcium influx. These findings highlight selenium's regulatory role in apoptosis and calcium entry via TRPM2 channels.