PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7645
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Article Tc-99m Erythromycin Lactobionate Inhalation Scintigraphy in Parenchymal Lung Diseases(Elsevier Science inc, 1999) Durak, H; Aktogu, S; Degirmenci, B; Sayit, E; Ertay, T; Dereli, SWe have investigated Technetium 99m erythromycin lactobionate (Tc 99m EL) clearance from the lungs after inhalation, in the presence of an alveolitis. Eighteen patients (6 sarcoidosis, 7 idiopathic fibrosis, and 5 miliary tuberculosis) were imaged after the patients inhaled 1,110 MBq of Tc 99m EL. Clearance half time for the first 45 min, for 24 h, and retention at 24 h correlated with percentage of lymphocytes in bronchoalveolar lavage fluid (BAL) (r =.729, r =.883, and r =.826, respectively). There was a positive correlation between peripheral penetration (PP) and forced expiratory volume in 1 s (FEV1) (r =.806) and forced vital capacity (FVC) (r =.781). Retention was more marked in sarcoidosis compared with tuberculosis (0.025 < p less than or equal to 0.05). Radioaerosol lung imaging may reflect the pulmonary function impairment in parenchymal lung diseases. Retention of Tc 99m EL may be related to number of BAL cells or presence of a lymphocytic alveolitis. Long residency time of Tc 99m EL in the lungs implies that erythromycin can also be administered by inhalation for therapeutic purposes. NUCL MED BIOL 26;6:695-698, 1999. (C) 1999 Elsevier Science Inc. All rights reserved.Article Nanostructured Ox-MWCNT-Ppy-Au Electrochemical Sensor for Ultralow Detection of Retrorsine and Evaluation of Its Cytotoxic Effects on Liver Cells(Taylor & Francis Ltd, 2025) Akturk, Ezgi Zekiye; Njjar, Muath; Ata, Melek Tunc; Kaya, Ahmet; Akdogan, Abdullah; Onac, CananThis study presents the development of a novel retrorsine (RTS)-imprinted sensor utilizing oxidized multi-walled carbon nanotubes (Ox-MWCNTs), polypyrrole (PPy), and gold nanoparticles (AuNPs), employing square wave voltammetry for the sensitive and selective detection of RTS which causes oxidative-stress and DNA damage. The fabricated Ox-MWCNT-PPy-AuNP sensor demonstrated a surface-area of (0.218 cm2) is 4.25 times larger than a bare glassy carbon electrode, with a low charge transfer resistance (10.9 Omega), enhancing electron transfer kinetics. The sensor showed excellent sensitivity in detecting retrorsine, with a limit of detection of 0.035 nM in synthetic matrices and -0.030 nM in HepaRG cell culture medium. Toxicity assays in HepaRG cells revealed dose-dependent oxidative-stress, with glutathione levels decreasing from 23.08 +/- 0.21 mu mol/109 to 21.21 +/- 0.02 mu mol/109 at 35 mu M retrorsine. Concurrently, GSSG levels increased from 1.32 +/- 0.26 mu mol/109 to 2.22 +/- 0.02 mu mol/109. DNA-damage assessed via comet assay, showed significant increases in tail-moment (2.53 mu m) and tail-migration (16.13 mu m). Oxidative DNA-damage, indicated by 8-OHdG levels, increased significantly from 0.29 +/- 0.02 ng.mL- (control) to 0.47 +/- 0.07 ng.mL- at 35 mu M retrorsine. These findings demonstrate the sensor's effectiveness for retrorsine detection and its applicability in toxicological studies. The integration of nanomaterial engineering and molecular imprinting provides a highly sensitive, selective, and eco-friendly solution for monitoring toxic agents and assessing their biological impacts.Article Citation - WoS: 1Citation - Scopus: 1Understanding the Role of a Specific Microenvironment in Personal Exposure To Semi-Volatile Organic Compounds Using Silicone Wristbands(Royal Soc Chemistry, 2025) Akmermer, Zulfikar; Demirtepe, HaleAssessment of personal exposure to semi-volatile organic compounds was facilitated using silicone wristbands (SWBs), an easy-to-use sampler that reflects total inhalation and dermal exposure from all the microenvironments and the activities in which the user was involved. Hence, SWBs help understand exposure from various routes, activities, and microenvironments. Offices are critical microenvironments where workers spend one-third of their daily time on weekdays; hence exposure from offices should be more extensively studied. This study aimed to investigate the personal exposure of university personnel and elaborate on the contribution of the exposure due to the office air to their overall exposure using SWBs. One SWB was worn by the participant, and another was hung in their office. After seven days of sampling on the wrist, exposure to polycyclic aromatic hydrocarbons (PAHs) was found to be related to combustion activities at home or from open fire, whereas exposure to organophosphate esters and phthalates was suggested to originate from building materials, such as flooring materials and paints, and consumer products, e.g. mattresses and furniture. PAHs in the participants' offices were influenced by the transport of outdoor air and phthalates from the ceiling material. Then, we estimated the equivalent air concentrations using the SWBs sampled from the offices and previously developed sampling rates and partition coefficients. The estimated office air exposure contributions to total inhalation and dermal exposure were 83%, 51%, and 39% for fluorene, tri(n-butyl) phosphate, and tris(2-chloro isopropyl) phosphate, respectively. These findings were consistent with the statistical analysis of personal data. To conclude, this study highlighted the importance of specific microenvironments in our exposure to particular SVOCs, offering strategies for indoor air quality management and human health risk assessment.Article Citation - WoS: 1Citation - Scopus: 1A Pragmatic Grouping Model for Bone-Only De Novo Metastatic Breast Cancer (MetS Protocol MF22-03)(MDPI, 2025) Goktepe, Berk; Demirors, Berkay; Senol, Kazim; Ozbas, Serdar; Sezgin, Efe; Lucci, Anthony; Soran, AtillaDe novo metastatic breast cancer (dnMBC) accounts for 3-10% of newly diagnosed cases, with 20-40% presenting as a bone-only metastatic disease, which can achieve survival outcomes exceeding 10 years with multimodal therapy. However, the role of multimodal therapy remains controversial in the guidelines. Objective: This study aims to identify dnBOMBC subgroups to develop a pragmatic staging system for guiding locoregional therapy decisions. Materials and Methods: Data from the MF07-01 phase III randomized trial (2021, median follow-up time (mFT): 40 months (range 1-131)) and the BOMET prospective multi-institutional registry trial (2021, mFT: 34 months (range 25-45)) were combined for analysis, including only patients who presented with bone-only metastases. Exclusion criteria were patients under 18 and those with a history of prior cancer or cancer metastases. Patients with missing data and positive surgical margins were excluded. Out of 770 patients, 589 were included. Survival analyses were first conducted according to molecular subgroups, after which patients were further stratified by hormone receptor status, human epidermal human epidermal growth factor receptor 2 (HER2) status, tumor grade, and clinical T (cT) stage. Group A (GrA) included hormone receptor (HR)-positive, low- or intermediate-grade tumors at any cT; HR-positive, high-grade tumors with cT0-3; or any HER2-positive tumors. Group B (GrB) included HR-positive, high-grade tumors with cT4 disease or any triple-negative (TN) tumors. Results: The hazard of death (HoD) was 43% lower in GrA than in GrB. Median OS was 65 months (39-104) for GrA patients and 44 months (28-72) for GrB patients (HR 0.57, 95% CI 0.41-0.78, p = 0.0003). Primary tumor surgery (PTS) significantly improved OS in GrA patients, regardless of the number of metastases (solitary: HR, 0.375, 95% CI 0.259-0.543, p < 0.001; multiple: HR 0.435, 95% CI 0.334-0.615, p < 0.001). Conversely, GrB patients did not experience a significant benefit from PTS. Conclusions: This study demonstrates that GrA patients have better OS than GrB patients, and PTS reduces the HoD in GrA patients compared to systemic therapy alone. These findings support using a modified staging system in dnBOBMC to identify patients who may benefit from multimodal therapy including PTS.Article Time-Dependent Effects of Low-Intensity Pulsed Ultrasound on Apoptosis and Autophagy in Malignant Melanoma Stem Cells(Wiley, 2025) Dikici, Omer; Ozdil, Berrin; Yesin, Taha Kadir; Dikici, Aylin; Adali, Yasemin; Aktug, HuseyinCancer stem cells (CSCs) in malignant melanoma contribute to therapeutic resistance and tumour recurrence. While low-intensity pulsed ultrasound (LIPUS) has been proposed as a non-invasive strategy to induce cell death, its effects on CSC-specific apoptotic and autophagic responses remain unclear. This study aimed to explore the time-dependent effects of LIPUS on apoptosis and autophagy in CD133+ melanoma CSCs and CD133- non-stem melanoma cells. Human melanoma cells (CHL-1) were sorted via FACS into CD133+ and CD133- populations. Cells were exposed to LIPUS (1 MHz, 20% duty cycle, 1 W/cm2) for 1, 5, and 10 min. Protein expression levels of Caspase-3, Caspase-8, mTOR, and LC3 were evaluated via immunofluorescence and quantified by image-based analysis. Both cell populations showed significant increases in Casp3, Casp8, mTOR, and LC3 intensities following LIPUS application. Notably, CD133+ cells exhibited delayed but sustained increases in Casp3 and LC3 expression, while CD133- cells responded more rapidly. mTOR activity demonstrated distinct temporal dynamics between the two groups, suggesting differential modulation of autophagy-related pathways. LIPUS triggers temporally distinct apoptotic and autophagic responses in melanoma CSCs and non-stem cancer cells. These findings suggest a potential therapeutic avenue to selectively disrupt CSC survival mechanisms using mechanical stimulation.Article Citation - WoS: 3Citation - Scopus: 4Evaluation of in Vivo and in Vitro Toxicity of Chestnut (Castanea Mollissima Blume) Plant: Developmental Toxicity in Zebrafish Embryos Cytotoxicity, Antioxidant Activity, and Phytochemical Composition by LC-ESI-MS/MS(John Wiley and Sons Inc, 2025) Demirtas, Ibrahim; Atalar, Mehmet Nuri; Bingol, Zeynebe; Kokturk, Mine; Ozhan, Gunes; Abdelsalam, Amine Hafis; Gulcin, IlhamiThe search for novel therapeutic agents has led to increasing interest in natural products, driven by the recognition that they may offer safer and more sustainable alternatives to synthetic drugs. This study aims to fill the gap in knowledge regarding the biological activity and safety of the water extract of chestnut (Castanea mollissima) (chestnut), a plant species with a long history of use in traditional medicine, by conducting a comprehensive evaluation of its antioxidant, antidiabetic, and neuroprotective properties. This study presents a comprehensive analysis of the water extract of chestnut for the first time using various bioanalytical antioxidant methods. The extract's inhibitory effects on key enzymes like acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and alpha-glycosidase were evaluated due to their relevance in metabolic and neurodegenerative disorders such as diabetes and Alzheimer's disease. Developmental toxicity and cytotoxicity were assessed using zebrafish (Danio rerio) embryos to evaluate the extract's biological safety. The major phenolic compounds present in the extract were identified by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS), revealing catechin, gallic acid, taxifolin, and epicatechin as the predominant constituents. Antioxidant capacity was determined through radical scavenging assays using 2,2-diphenyl-1-picrylhydrazyl (DPPH center dot) and 2,2 '-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS center dot+), alongside ferric (Fe3+), cupric (Cu2+), and Fe3+-TPTZ (ferric-tripyridyltriazine) reducing power assays. The findings highlight the significant antioxidant, antidiabetic, and neuroprotective potential of the chestnut water extract, supporting its prospective use in pharmaceutical and nutraceutical applications.Article Citation - WoS: 5Citation - Scopus: 5Magnetically Controllable and Degradable Milliscale Swimmers as Intraocular Drug Implants(Wiley, 2025) Yildiz, E.; Bozuyuk, U.; Yildiz, E.; Wang, F.; Han, M.; Karacakol, A.C.; Sitti, M.Intraocular drug implants are increasingly used for retinal treatments, such as age-related macular degeneration and diabetic macular edema, due to the rapidly aging global population. Although these therapies show promise in arresting disease progression and improving vision, intraocular implant-based therapies can cause unexpected complications that require further surgery due to implant dislocation or uncontrolled drug release. These frequent complications of intraocular drug implants can be overcome using magnetically controllable degradable milliscale swimmers (MDMS) with a double-helix body morphology. A biodegradable hydrogel, polyethylene glycol diacrylate, is employed as the primary 3D printing material of MDMS, and it is magnetized by decorating it with biocompatible polydopamine-encapsulated iron-platinum nanoparticles. MDMS have comparable dimensions to commercial intraocular implants that achieve translational motions in both aqueous and vitreous bodies. They can be imaged in real-time using optical coherence tomography, ultrasound, and photoacoustic imaging. Thanks to their biodegradable hydrogel-based structure, they can be loaded with anti-inflammatory drug molecules and release the medications without disrupting retinal epithelial viability and barrier function, and decrease proinflammatory cytokine release significantly. These magnetically controllable swimmers, which degrade in a couple of months, can be used for less invasive and more precise intraocular drug delivery compared to commercial intraocular drug implants. © 2025 The Author(s). Advanced Science published by Wiley-VCH GmbH.Article Citation - WoS: 2Citation - Scopus: 2Tuning Toxicity Profiles of Graphene Oxide Through Imidazole-Oxime Modification: Zebrafish as a Model System(Oxford Univ Press, 2025) Yildirim, Serkan; Kokturk, Mine; Yigit, Aybek; Sahin, Ayse; Kiliclioglu, Metin; Atamanalp, Muhammed; Alak, GoncaThe increasing use of nanotechnology, especially in agriculture and the food industry, has raised concerns about the possible adverse effects of nanomaterials (NMs) on human health and the environment. This study investigates the effects of synthesized graphene oxide (GO) and its derivatives on zebrafish exposed for 96 hr, focusing on morphological changes in brain tissue, histopathology, and immunofluorescent markers such as 8-hydroxy-2'-deoxyguanosine (8-OHdG) and nucleolar protein 10 (NOP10). Exposure to GO resulted in malformations, DNA damage, and increased NOP10 expression, and it reduced hatching and survival rates. Our results demonstrated that exposure to GO, graphene oxide-oxime (GO-OX), and OX exerted dose-dependent inhibitory effects on hatching and promoted malformations in zebrafish larvae. Histopathological analysis revealed that higher doses led to more pronounced tissue damage, with GO 50 causing severe degeneration and necrosis, while high doses of GO-OX and OX resulted in moderate tissue changes. This was further supported by the increased expression levels of 8-OHdG (marker of oxidative DNA damage) and NOP10 (marker of nucleolar stress), which aligns with the histopathological findings and confirms the neurotoxic effects. Notably, GO-OX treatments consistently mitigated both morphological and neurotoxic effects at all doses, suggesting that oxime functionalization reduces the inherent toxicity of GO. In contrast, treatment with different concentrations of GO-OX derivatives mitigated these adverse effects, reducing them to mild or moderate levels.Article Durable ZrB2–ZrC Composite Materials as Advanced Electrodes for High-Performance Supercapacitors(Amer Chemical Soc, 2025) Paksoy, Aybike; Gungor, Ahmet; Yildirim, Ipek Deniz; Arabi, Seyedehnegar; Erdem, Emre; Balci-Cagiran, OzgeBoride and carbide-based materials attract increasing attention as promising options for energy storage applications. This research focuses on synthesizing pure boride and carbide compounds of zirconium (ZrB2 and ZrC) and their composite powders using mechanical activation-assisted route and subsequent heating processes. The chemical and microstructural characterization results indicate that the synthesized composite powders are of high purity, possess submicron-scale particle sizes (below 400 nm), and exhibit a high surface area of up to 9.41 m2/g. Supercapacitor devices, using the resulting powders as symmetrical electrodes, exhibit high energy density values ranging from 5.8 to 8.8 Wh/kg. The ZrB2-15 wt % ZrC composite sample achieves the highest power density at 155 W/kg, compared to 118 W/kg for the pure ZrB2 sample. Cycling tests demonstrate exceptional capacitance retention (99.4-99.9%) and cyclic stability, even after 5000 cycles, highlighting the high durability of the composite samples. These findings show that ZrB2-ZrC composites exhibit high energy and power density values and excellent cycling performance, making them strong candidates for use in high-performance supercapacitor devices.Article Citation - WoS: 2Citation - Scopus: 2Modulating Cancer Stem Cell Characteristics in CD133+ Melanoma Cells through Hif1α, KLF4, and SHH Silencing(Amer Chemical Soc, 2025) Ozdil, Berrin; Güler, Günnur; Avci, Cigir Biray; Calik-Kocaturk, Duygu; Gorgulu, Volkan; Uysal, Aysegul; Guler, Gunnur; Aktug, HuseyinMalignant melanoma is a highly aggressive form of skin cancer, partly driven by a subset of cancer stem cells (CSCs) with remarkable capacities for self-renewal, differentiation, and resistance to therapy. In this study, we examined how silencing three key genes-Hif1 alpha, KLF4, and SHH-affects CSC characteristics. Using small interfering RNA (siRNA)-based approaches, we observed significant changes at both the gene and protein levels, shedding light on how these pathways influence melanoma progression. Our results demonstrated that silencing these genes reduces the stem-like features of CSCs. Notably, Hif1 alpha silencing triggered a marked decrease in hypoxia-related gene expression, while targeting SHH led to a reduction in Gli1, a downstream effector of SHH signaling, highlighting its potential as a therapeutic target. We also observed changes in epigenetic markers such as HDAC9 and EP300, which play crucial roles in maintaining stemness and regulating gene expression. Interestingly, these interventions appeared to reprogram CSCs, pushing them toward a phenotype distinct from both traditional CSCs and non-stem cancer cells (NCSCs). Our findings emphasize the importance of targeting key signaling pathways in melanoma CSCs and underscore the value of mimicking the tumor microenvironment in experimental models. By revealing the dynamic plasticity of melanoma CSCs, this study offers fresh insights into potential therapeutic strategies, particularly using siRNA to modulate pathways associated with tumor progression and stem cell behavior.