Publications by authors named "Guelderen Yanıkkaya-Demirel"

Background: Zinc (Zn), an essential micronutrient, regulates and maintains neurological functions. However, both Zn deficiency and excess can cause oxidative stress and neurodegenerative diseases. As previously reported, immunoglobulin G (IgG) can modulate oxidative stress in various disorders.

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Despite advances in cancer treatment, hepatocellular carcinoma (HCC), the most common form of liver cancer, remains a major public health problem worldwide. The immune microenvironment plays a critical role in regulating tumor progression and resistance to therapy, and in HCC, the tumor microenvironment (TME) is characterized by an abundance of immunosuppressive cells and signals that facilitate immune evasion and metastasis. Recently, anti-cancer immunotherapies, therapeutic interventions designed to modulate the immune system to recognize and eliminate cancer, have become an important cornerstone of cancer therapy.

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Introduction: Following major developments in cancer immunotherapy, treatments targeting immune checkpoint proteins (ICP) gained interest in breast cancer, though studies mostly focus on patients with metastatic disease as well as patients nonresponsive to the conventional treatments. Herein, we aimed to investigate the levels of ICP in tumor stroma and tumor infiltrating lymphocytes, and tumor tissue prior to neoadjuvant chemotherapy administration to evaluate the relationship between ICP levels, clinicopathological parameters, and NAC response.

Materials And Methods: This study was conducted with 51 patients where PD-1, PD-L1, CTLA-4, TIM-3, CD24 and CD44 levels were investigated in CD45 cells while CD326, CD24, CD44 and PD-L1 protein expression levels were investigated in CD45 population.

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This review aims to summarize the latest evidence about the role of innate and adaptive immunity in Amyotrophic Lateral Sclerosis (ALS). ALS is a devastating neurodegenerative disease affecting upper and lower motor neurons, which involves essential cells of the immune system that play a basic role in innate or adaptive immunity, that can be neurotoxic or neuroprotective for neurons. However, distinguishing between the sole neurotoxic or neuroprotective function of certain cells such as astrocytes can be challenging due to intricate nature of these cells, the complexity of the microenvironment and the contextual factors.

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Background: Various studies have reported the effects of testosterone on different cell types, yet bone marrow-derived mesenchymal stem cells’ cellular responses to testosterone remain unknown.

Aims: To investigate the effects of testosterone propionate, an oil-soluble short-acting form of testosterone, on human bone marrow-derived mesenchymal stem cells’ proliferation and viability after 24 hours of incubation. We also investigated the impact of testosterone propionate on bone marrow-derived mesenchymal stem cell’s polarization and cytotoxicity on K562 leukemia cell line.

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Acute myeloid leukemia (AML) arises from the cells of myeloid lineage and is the most frequent leukemia type in adulthood accounting for about 80% of all cases. The most common treatment strategy for the treatment of AML includes chemotherapy, in rare cases radiotherapy and stem cell and bone marrow transplantation are considered. Immune checkpoint proteins involve in the negative regulation of immune cells, leading to an escape from immune surveillance, in turn, causing failure of tumor cell elimination.

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Cytotoxic activity-guided isolation studies on the underground parts of Valeriana sisymbriifolia Vahl. led to the isolation of 12 secondary metabolites including two undescribed iridoids, sisymbriifolivaltrate and sisymbriifolioside, and two unreported sesquiterpene lactones, sisymbriifolins A and B. Chemical structures of the isolates were established by extensive 1D and 2D NMR analyses as well as HR-ESI-MS.

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Background: This study aims to evaluate humoral immune system response by measuring copy numbers of kappa-deleting recombination excision circles (KREC) gene segment from B lymphocytes in patients with lung transplantation.

Methods: Between September 2015 and November 2016, a total of 11 patients (8 males, 3 females; mean age: 45.4±12.

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The aim of this study was to isolate the cytotoxic compounds from V. alliariifolia via activity-guided isolation and to determine the mechanism of actions of the most potent ones. The crude EtOH extract as well as CHCl and AcOEt subextracts demonstrated remarkable cytotoxic activities against A549, MCF7, HGC27 and PC3 cancer cells.

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Colorectal cancer ranks as the third most lethal cancer worldwide, resulting in over 1 million cases and 900 000 deaths per year. According to population-based studies, administration of long-term non-steroidal anti-inflammatory drugs (NSAIDs) was proven to reduce the risk of a subject developing colorectal cancer. In the present study, the anti-cancer activity of two different NSAIDs, sulindac- () or diclofenac-substituted () asymmetric silicon phthalocyanine derivatives, was evaluated in four different colorectal cancer cell lines bearing various carcinogenic mutations.

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The development of immune checkpoint inhibitors, the monoclonal antibodies that modulate the interaction between immune checkpoint molecules or their ligands on the immune cells or tumor tissue has revolutionized cancer treatment. While there are various studies proving their efficacy in hematological malignancies, there is also a body of accumulating evidence indicating that immune checkpoint inhibitors' clinical benefits are limited in such diseases. In addition, due to their regulatory nature that balances the immune responses, blockade of immune checkpoints may lead to toxic side effects and autoimmune responses, and even primary or acquired resistance mechanisms may restrict their success.

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The aim was to compare granulosa cell's (GCs) apoptosis rate with (group A) or without (group B) luteinising hormone (LH) supplementation in poor ovarian responders (PORs) during controlled ovarian stimulation (COS). After oocyte retrieval, the follicular fluid was analysed by cytoflowmetry. Primary outcomes were GCs apoptosis rate in terms of viability, early apoptosis, late apoptosis and necrosis.

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In this study, we synthesized and characterized a silicon phthalocyanine substituted with 3-hydroxypyridin-2-thione (), designed to be a chemophotodynamic therapy agent acting as a histone deacetylase inhibitor, and we determined its photophysical, photochemical, and photobiological properties. Next, we evaluated its anticancer efficacy on MCF-7, double positive and MDA-MB-231, triple negative breast cancer cell lines, as well as on a healthy human endothelial cell line (HUVEC). Our results indicate that can target nucleoli of cells, effectively inducing apoptosis while promoting cell cycle arrest thanks to its high singlet oxygen yield and its histone deacetylase downregulating properties, suggesting a powerful anticancer effect on breast cancer .

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Many anticancer therapies such as antibody-based therapies, cellular therapeutics (e.g., genetically modified cells, regulators of cytokine signaling, and signal transduction), and other biologically tailored interventions strongly influence the immune system and require tools for research, diagnosis, and monitoring.

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Regeneration of nerve tissue is a challenging issue in regenerative medicine. Especially, the peripheral nerve defects related to the accidents are one of the leading health problems. For large degeneration of peripheral nerve, nerve grafts are used in order to obtain a connection.

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Oxidized cellulose is the most used hemostatic materials in clinical applications. In addition to its perfect hemostatic efficiency, it is degradable under in vivo conditions and supremely prevents bacterial growth. On the other hand, one of the drawbacks of the oxidized cellulose is cytotoxicity due to the strongly acidic nature during degradation.

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Hernia surgeries are at the top of the general surgery operations. However, visceral adhesion, which is one of the worst complications of these operations, is still a major problem. One of the most preferred methods to prevent adhesion is the use of biomaterials.

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Activated platelets and glycated lipoproteins are responsible for atherothrombosis in diabetics. Melatonin and native high-density lipoproteins are crucial in the preservation of pro/oxidant-antioxidant balance. The aim of the present study was to investigate the in vitro effects of native high-density lipoproteins and melatonin on altering the platelet response induced by glycated lipoproteins.

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Effective hemostatic materials are of utmost importance for preventing bleeding in emergencies and critical injuries. Combining biodegradability, good hemostatic properties and biocompatibility, gelatin is one of the most reliable materials clinically used for preventing internal bleeding in surgeries and for stopping external hemorrhage. Cross-linking is a useful method for enhancing the absorption capacity of gelatin and for controlling the degradation process.

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Regeneration of nerve, which has limited ability to undergo self-healing, is one of the most challenging areas in the field of tissue engineering. Regarding materials used in neuroregeneration, there is a recent trend toward electrically conductive materials. It has been emphasized that the capacity of conductive materials to regenerate such tissue having limited self-healing ability improves their clinical utility.

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Behcet's disease (BD) exhibits more severe disease course and higher mortality among male patients. However, underlying mechanisms of gender differences in clinical manifestations and disease severity are unclear. The aim of this study was to determine whether testosterone (T) has any role on BD pathogenesis.

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