Recep Tayyip Erdoğan Üniversitesi Kurumsal Akademik Arşivi
DSpace@RTEÜ, Recep Tayyip Erdoğan Üniversitesi tarafından doğrudan ve dolaylı olarak yayınlanan; kitap, makale, tez, bildiri, rapor, araştırma verisi gibi tüm akademik kaynakları uluslararası standartlarda dijital ortamda depolar, Üniversitenin akademik performansını izlemeye aracılık eder, kaynakları uzun süreli saklar ve yayınların etkisini artırmak için telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
Histopathological and Immunohistochemical Evaluation of the Effects of Amifostine on Radiation-Induced Pancreatic Injury: A Pilot Study
(Pera Yayıncılık, 2026) Çiftel, Enver; Mercantepe, Filiz; Tümkaya, Levent; Genç, Ömer; Rakıcı, Sema; Yılmaz, Hamit; Mercantepe, Tolga
Objective: Ionizing radiation is widely used in cancer treatment but can cause damage to non-target tissues, including the pancreas. Amifostine is a cytoprotective agent shown to protect certain normal tissues from radiation injury. Given the structural and functional similarities between the pancreas and other exocrine glands such as the parotid, we hypothesized that amifostine could confer radioprotection to pancreatic islets. Method: Male rats were divided into three groups: control (no intervention), irradiation (whole-body abdominal exposure), and irradiation + amifostine (200 mg/ kg intraperitoneally, 30 min prior to irradiation). Pancreatic tissues were examined histologically using hematoxylin-eosin staining and immunohistochemically for insulin, glucagon, and somatostatin expression. Results: Irradiation induced significant histological damage in both endocrine and exocrine pancreas, characterized by cytoplasmic vacuolization and necrosis. Amifostine pretreatment did not prevent these alterations; the extent of histological injury in the irradiation + amifostine group was comparable to the irradiation group. Immunohistochemistry revealed decreased insulin and glucagon positivity in both irradiated groups compared to controls, whereas somatostatin expression was paradoxically increased. Conclusion: In this pilot model, amifostine failed to protect pancreatic islets from radiation-induced injury, suggesting organ-specific variability in its cytoprotective efficacy. These findings indicate that amifostine's benefit may depend on tissue-specific activation, pharmacokinetics, and radiation sensitivity, and that optimized, pancreastargeted protective strategies are needed.
Nutrient-derived modulation of the gremlin-1/BMP-4 axis by white tea preserves insulin sensitivity during early diet-induced metabolic dysregulation
(Multidisciplinary Digital Publishing Institute (MDPI), 2026) Arpa, Medeni; Şen, Bayram; Atak, Mehtap; Kılıç, Hülya
Given the increasing burden of diet-induced metabolic dysregulation, preventive nutritional strategies targeting early insulin resistance are of growing interest. The aim of this study was to evaluate the effects of white tea supplementation on body weight gain, insulin resistance, and the Gremlin-1/Bone Morphogenetic Protein-4 (BMP-4) axis in visceral adipose tissue under high-fat diet conditions in a non-obese experimental model. Thirty-two male Sprague–Dawley rats were randomized into four groups (n = 8/group): standard diet (control), only high-fat diet (HFD), high-fat diet plus orlistat (ORL: 30 mg/kg/day), and high-fat diet plus white tea (WT: 5 mg/kg/day). Interventions were administered once daily by oral gavage for 12 weeks. Body weight was recorded weekly. At the end of the study, serum insulin, Gremlin-1, and BMP-4 and retroperitoneal adipose tissue Gremlin-1 and BMP-4 levels were measured by ELISA. Adipose tissue GREM1 gene expression was quantified by qRT-PCR. Insulin resistance was estimated using the HOMA-IR index. Appropriate statistical analyses were conducted in line with the study design and data distribution. High-fat feeding resulted in the highest HOMA-IR values, whereas white tea supplementation reduced HOMA-IR compared to the HFD group (p = 0.008). Body weight gain was increased in both the HFD and ORL groups compared to the control (p = 0.009 and p = 0.012, respectively). The lowest weight gain was observed in the WT group, which was lower than the HFD group (p = 0.044). GREM1 expression showed a 1.92-fold increase in the HFD group relative to the control, with smaller increases in the WT and ORL groups; however, intergroup differences did not reach statistical significance (p = 0.063). Serum BMP-4 levels were lower in the WT group compared to the control (p = 0.012), while tissue BMP-4 and Gremlin-1 levels did not differ between groups. Correlation analyses revealed a moderate inverse association between serum Gremlin-1 and serum BMP-4 (rho = −0.493, p = 0.011) and a moderate positive correlation between serum BMP-4 and HOMA-IR (rho = 0.564, p = 0.003). White tea supplementation attenuated body weight gain and preserved insulin sensitivity in a non-obese high-fat diet model, as evidenced by reduced weight gain and lower HOMA-IR values compared with high-fat feeding alone. These metabolic improvements were accompanied by coordinated changes in circulating components of the Gremlin-1/BMP-4 axis, including reduced serum BMP-4 levels and associations between BMP-4, Gremlin-1, and insulin resistance. Although tissue-level alterations were modest, the observed systemic patterns are consistent with an exploratory association between white tea intake and early metabolic signaling changes; however, definitive pathway modulation cannot be inferred from the present dataset. Collectively, these findings support white tea as a nutrient-derived bioactive with preventive metabolic potential during the early stages of diet-induced metabolic dysregulation, prior to the development of overt obesity.
Postexposure prophylaxis for HIV among healthcare workers in Türkiye: a descriptive, multicenter retrospective study
(Tubitak Scientific & Technological Research Council, 2026) Akca, Veysel; Akbulut, İlkay; Yılmaz, Gül Ruhsar; Tahmaz, Alper; Öztoprak Çuvalcı, Nefise; Yıldız, İlknur Esen; Togan, Turhan
Abstract
Background/aim: Post-exposure prophylaxis (PEP) for human immunodeficiency virus (HIV) plays a vital role in preventing transmission among healthcare workers following occupational exposure. Despite its clinical importance, epidemiological data regarding PEP implementation in Türkiye remain scarce. This study aimed to assess PEP practices, prophylactic treatment regimens, and follow-up outcomes among healthcare workers at risk of occupational HIV exposure.
Materials and methods: This retrospective, multicenter study was conducted between January 2020 and December 2024 across 16 healthcare facilities participating in the National HIV/AIDS Working Group. Healthcare workers aged 18 years and older who presented for evaluation following occupational exposure to HIV were included. Data on demographics, exposure characteristics, source patient test results, PEP initiation timing, regimen preferences, adverse effects, and follow-up outcomes were collected from hospital records and analyzed using SPSS version 25.0.
Results: A total of 369 healthcare workers were assessed. The PEP initiation rate was 49.1%. Needlestick injuries accounted for 79.4% of occupational exposures, and nurses constituted nearly half of presentations (49.6%). In univariable analyses, PEP initiation was less frequent among nurses than among other healthcare staff. In the multivariable model, male gender and age ≥40 years were independently associated with higher odds of PEP initiation, whereas nursing profession was associated with lower odds. The median time to PEP initiation was 17.9 hours (range: 0–120). Adverse effects were uncommon (3.5%), most frequently nausea and vomiting. No HIV seroconversions were identified among individuals with available follow-up results; however, follow-up testing at the predefined time points was incomplete, which limits the ability to exclude rare late seroconversions
Conclusion: Timely initiation of HIV PEP appears feasible and well tolerated in real-world occupational settings. These findings highlight the need for standardized institutional protocols and improved follow-up strategies for healthcare workers in Türkiye.
Microplastic contamination in honey: a one health-oriented systematic review and risk assessment
(Kafkas University, 2026) Başaran, Burhan; Usman, Andi Nilawati; Kaya, Mukerrem; Kaban, Guzin
Microplastics have become pervasive environmental contaminants with the capacity to move across ecological and biological systems. Honey represents a unique food matrix in this context because it is produced through intensive interactions between honeybees and their surrounding environment and is consumed directly by humans with minimal processing. This review synthesizes current evidence on microplastic contamination in honey, evaluates reported concentration ranges, particle characteristics, and polymer profiles, and situates these findings within a One Health framework linking environmental pollution, bee health, and human exposure. Microplastics have been reported in honey samples from multiple geographic regions worldwide, although reported concentrations vary considerably among studies. Notably, only a limited number of investigations have translated contamination data into consumption-based exposure estimates, underscoring a significant gap in quantitative risk assessment. Experimental and field studies further indicate that microplastics can affect honeybee physiology, immunity, behavior, and colony dynamics, and that contaminated bees can transfer particles to hive products, including honey. Collectively, these findings support the use of honey as a sentinel matrix for tracing environmental microplastic pollution through biological pathways to the human diet. Addressing existing knowledge gaps through standardized methodologies and integrated exposure assessments is essential for advancing risk evaluation within a One Health perspective.
Bioelectrical impedance-derived phase angle as a contextual indicator for steatotic liver disease and hepatic fat estimation
(Frontiers Media SA, 2026) Sabuncular, Güleren; Çelik, Zehra Margot; Demirtaş, Coşkun Özer; Aktaç, Şule; Eren, Fatih
Steatotic liver disease (SLD) is highly prevalent among individuals with metabolic risk factors, highlighting the need for accessible, non-invasive tools that can support nutritional and clinical risk contextualization. Phase angle, derived from bioelectrical impedance analysis, reflects cellular integrity and body composition and is widely used in nutritional assessment. In this cross-sectional study, 495 adults underwent multi-frequency bioelectrical impedance analysis and hepatic fat evaluation using the controlled attenuation parameter obtained by FibroScan (R). Participants were classified as having SLD based on a controlled attenuation parameter threshold of >= 275 dB/m. Individuals with SLD exhibited significantly higher whole-body and segmental phase angle values compared with those without SLD, and these differences were consistent across age and obesity subgroups (p < 0.05). Whole-body phase angle demonstrated moderate discriminative ability for SLD status (area under the curve = 0.646), supporting its role as a contextual indicator rather than a diagnostic measure. In multivariable logistic regression analyses, phase angle remained independently associated with SLD alongside waist circumference and age, whereas body mass index and body fat percentage were not statistically significant. Additionally, a regression-based model incorporating phase angle and simple anthropometric variables showed good performance in estimating hepatic fat content (area under the curve = 0.807). Overall, these findings indicate that phase angle reflects bioelectrical properties influenced by body composition associated with clinically relevant hepatic steatosis.
