Araştırmacılar(5)

• Alemdar, Adem
• Aydin, Suleyman
• Ergin, Volkan
• Gürbüzel, M.
• Yildiz, Gökhan

• ArticleYayıncıda açık erişim2026/r/ebyu/11434
  Determination of antimicrobial activity of Niaouli Essential Oil (Melaleuca quinquenervia) by two different methods; [Nioli Esansiyel Yağının (Melaleuca quinquenervia) antimikrobiyal aktivitesinin iki farklı yöntemle belirlenmesi]

  Akyüz, Sümeyye

  Objective: This study aimed to investigate the antimicrobial activity of Niaouli Essential Oil (Melaleuca quinquenervia), a commercially available oil known for its antiseptic, antimicrobial, antioxidant, anti-inflammatory, and antiprotozoal properties due to its bioactive constituents, against eight different standard bacterial strains, two standard yeast strains, and one clinical Candida isolate. Methods: The antimicrobial activity of niaouli essential oil against the isolates was evaluated using the disk diffusion and broth microdilution methods in accordance with EUCAST and CLSI guidelines. Ten of the microbial strains were American Type Culture Collection (ATCC) strains, and one was a clinical Candida auris isolate. The isolates were obtained from the strain collection of our university. Results: In this study, the disk diffusion method revealed that niaouli essential oil (Melaleuca quinquenervia) was most effective against Staphylococcus aureus (20 ± 0.0 mm) and Streptococcus pneumoniae (17.3 ± 0.57 mm) among the bacterial strains, and against Candida albicans (20.6 ± 0.57 mm) among the fungal strains. The Candida auris isolate exhibited an inhibition zone of 16.0 ± 1.0 mm. The lowest MIC values determined by the broth microdilution method were 62.5 μg/mL for both S. aureus and C. albicans. Among the Gram-negative isolates, Klebsiella pneumoniae was the most susceptible (125 μg/mL), whereas Pseudomonas aeruginosa, Salmonella enteritidis, and Enterococcus faecalis were the least susceptible (>250 μg/mL). The MIC value for C. auris was determined to be 250 μg/mL, which is one dilution higher than the positive control (fluconazole: 125 μg/mL). Conclusion: Niaouli essential oil demonstrated antimicrobial activity against standard microbial strains, with varying levels of antibacterial and antifungal effects. According to both methods used, it was more effective against Gram-positive bacteria and fungi than Gram-negative bacteria. While it was particularly effective against Candida albicans among the yeasts, it also exhibited antimicrobial activity against the increasingly important Candida auris strain. Due to the increasing resistance to antibacterial and antifungal agents, further studies investigating alternative treatment options are needed.

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• Review ArticleYalnız künye2026/r/ebyu/10662
  Genotype-phenotype correlation of CFTR variants in cystic fibrosis patients

  Canitez, Yakup; Ozemri Sag, Sebnem; Nalbant, Nurdeniz; Alemdar, Adem; Hayme, Serhat; Korkmaz, Merve; Demirdogen, Ezgi; Celebi, Solmaz; Hacimustafaoglu, Mustafa Kemal; Ozgur, Taner

  Introduction: Cystic fibrosis (CF) is a life-limiting autosomal recessive disorder caused by mutations in the CFTR gene. In Turkiye, high genetic diversity and consanguinity contribute to a heterogeneous CFTR variant spectrum; however, genotype–phenotype data remain limited. Methods: This retrospective study analyzed 92 Turkish CF patients (36 homozygous, 56 compound heterozygous) to characterize CFTR variant diversity and clinical outcomes. Next-generation sequencing (NGS) was performed and confirmed by Sanger sequencing. Clinical data were analyzed using chi-square and nonparametric tests (p < 0.05). Results: A total of 46 distinct CFTR variants were identified. The most frequent were F508del (24%), followed by Y515X (7.33%), G542X (6%), N1303K (5.33%) and D110H (4%). Meconium ileus (p = 0.017) and CF-related diabetes mellitus (p = 0.013) were significantly more frequent among homozygous patients. Pseudomonas aeruginosa and Staphylococcus aureus were the most prevalent pathogens. CFTR modulator therapy eligibility was significantly higher among compound heterozygous patients (p = 0.007). Non-missense variants were associated with higher sweat chloride levels and more frequent severe pancreatic insufficiency and abnormal fecal fat quantification compared with missense variants (p = 0.037; p = 0.001; p = 0.033). Conclusion: This study highlights the heterogeneous CFTR variants in Turkiye and suggests genotype–phenotype correlations. Homozygous patients tended to show more severe gastrointestinal and endocrine involvement, while compound heterozygotes may exhibit comparatively milder disease features and higher treatment eligibility.

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• ArticleYayıncıda açık erişim2026/r/ebyu/10450
  Evaluation of Epithelial Cell Adhesion Molecule, Galectin-3, and Proliferative Cell Nuclear Antigen Expression in Thyroid Papillary Carcinomas and Their Lymph Node Metastases

  Daltaban, F.; Sayar, I.; Tayfur, M.; Gürbüzel, M.; Balcı, M.

  Background: Thyroid papillary carcinoma (PTC) is the most common carcinoma of thyroid carcinomas and endocrine carcinomas. The diagnosis of thyroid PTC is made mainly by the presence of nuclear features such as nuclear clearing, groove, and nuclear inclusions. Some benign lesions of the thyroid may have nuclear features and growth patterns of papillary thyroid carcinomas, which can make the differential diagnosis difficult. Different immunohistochemical markers have always been needed to reduce diagnostic errors and detect malignancies in routine practice. As in all tumor cases, studies continue to understand carcinogenesis in thyroid carcinomas. One of the ways that can help understand this involves the use of new and effective immunohistochemical markers. Aim: This study aimed to examine the expression of epithelial cell adhesion molecule (EpCAM), Galectin-3 (Gal-3), and proliferative cell nuclear antigen (PCNA), which are immunohistochemical markers that may contribute to the diagnosis and prognosis of thyroid PTCs and lymph node (LN) metastases. Materials and Methods: EpCAM, Gal-3, and PCNA immunohistochemical markers were applied to 26 unifocal (UF) thyroid PTC cases and 25 thyroid PTC cases with LN metastasis or multifocal (MF) tumor field. Results: It was observed that the Gal-3 staining score decreased significantly in the LN metastasis focus compared to the UF tumor. With EpCAM significant loss of membranous expression was observed in the MF tumor compared to the UF tumor. There was no statistically significant difference between the case groups in terms of PCNA staining score. Conclusions: These results may be important in terms of obtaining new immunohistochemical clues for diagnosis and carcinogenesis in thyroid PTCs and their metastases. The number of cases in our study is limited, and we think that supporting the results with a large series of studies may contribute to the diagnosis and prognosis of the patients.

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• ArticleYayıncıda açık erişim2025/r/ebyu/11415
  A direct association between suicide and reduced amygdala volume: A retrospective study

  Emre, Elif; Yildiz, Sevler; Rumeysa Yaman Baran, Ayse; Kilicarslan, Gulhan; Aydin, Suna; Agirbas, Esra Piril; Emir, Burcu Sirlier; Sahin, İbrahim; Aydin, Suleyman

  Objective: The neurological causes of suicide remain poorly understood. This study sought to ascertain whether there is a correlation between amygdala volume and suicidal behavior. Methods: This case–control retrospective study included 193 participants—108 healthy controls and 85 individuals with a history of suicide attempts. Sagittal magnetic resonance imaging was conducted for each participant, and cross-sectional areas of the left and right amygdala were determined independently using freehand tracing. The total volume of the amygdala was determined by multiplying the thickness of the slices by the sum of the regions. Results: Patients with a history of suicide attempts had significantly decreased amygdala volumes on both the right (p = 0.018) and left (p = 0.036) sides compared with controls. Receiver operating characteristic analysis determined a cutoff value of 1825 mm³ for both hemispheres. The cutoff sensitivity and specificity for the right amygdala were 30.6% and 88%, whereas the values for the left amygdala were 31.8% and 84.3%, respectively. Conclusions: This is the first study to show that individuals who had attempted suicide had considerably decreased left and right amygdala volumes, with receiver operating characteristic analysis indicating good specificity (84.3%–88%). According to these findings, a reduced amygdala volume might be a useful biomarker for identifying those who are at risk of attempting suicide. © The Author(s) 2025. Creative Commons Non Commercial CC BY-NC: This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).

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• ArticleYayıncıda açık erişim2024/r/ebyu/12052
  Some animal protein antigens identified in cells of two plant species

  Sahin, İbrahim; Eroksuz, Yesari; Ugur, Kader; İncili, Canan Akdeniz; Eroksuz, Hatice; Aydin, Gizem Nur; Ozpolat, Emine; Bildirici, Furkan; Aydin, Suleyman

  Objectives: It has been recently reported that immune activity of some animal peptides/proteins has been found in some plants. In this study, the presence of immune reactivity of alarin, asprosin, paraoxonase, elabela, glucagon, and nesfatin-1 like molecules was investigated in two plant species related to Kastamonu Taşköprü garlic (an endemic cultivar of the Allium sativum L.) and Tunceli garlic (Allium tuncelianum). Methods: Ten Kastamonu and 10 Tunceli garlic were embedded in paraffin blocks and 4–5 μm transversal and longitudinal sections were taken and stained by immunohistochemical method. In addition, 500 mg of wet tissue samples were homogenized from these garlic and supernatants were obtained. The amounts of alarin, asprosin, elabela, glucagon and nesfatin-1 were studied by enzyme linked immunosorbent assay (ELISA) method and paraoxonase was studied by spectrophotometric method. Results: Studied molecules show immune reactivity in the cytoplasm of the bulb storage cells of the plants parenchyma. The ELISA supernatant results also confirmed the presence of these animal molecules in the plants. Conclusions: Although we cannot reveal the purpose of the presence of these animal molecules detected in plants with these existing data, we predict that these data will be a source of inspiration in the field of botany, that studies will shift in this direction and that they might contribute to the revision of the evolutionary processes of all living things, especially an ancestor of garlics.

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• ArticleAçık Erişim2023/r/ebyu/20253
  The Effect of Resveratrol on Ischemia–Reperfusion Induced Oxidative Rat Ovary Injury: A Biochemical, Histopathological, and Genetic Evaluation

  Sayar, Ilyas; Bakan, Nuri; Gürbüzel, Mehmet; Akbaş, Nergis

  Objective: The cellular protective effects of resveratrol and co-enzyme Q10 supplementation have been reported in different models. However, there is insufficient data on the effects of resveratrol supplementation on oxidative DNA damage and co-enzyme Q10 levels in ovarian ischemia–reperfusion injury. The current study aims to investigate how resveratrol supplementation affects oxidative DNA damage, co-enzyme Q10 levels, inflammatory and proinflammatory indicators, and growth factors in ovarian ischemia– reperfusion injury. Methods: Thirty albino Wistar female rats were divided into 5 groups; control, ovarian ischemia–reperfusion, and ischemia–reperfusion + treatment (25, 50, and 100 mg/kg resveratrol). Hematoxylin–eosin stain was used to evaluate histopathological results. The levels of 8-oxo-2ʹ-deoxy guanosine and co-enzyme Q10 were obtained by enzyme-linked immunosorbent assay. Following RNA isolation, the expression of tumor necrosis factor-α , interleukin-1β, transforming growth factor-β3, hepatocyte growth factor, epidermal growth factor, and vascular endothelial growth factor was assessed. Results: Regarding the histopathological evaluation score, 8-oxo -2ʹ-d eoxyg uanos ine levels, and co-enzyme Q10 levels, there was no statistically significant difference between the ischemia–reperfusion group and the groups that received resveratrol treatment. Tumor necrosis factor-α, interleukin-1β, transforming growth factor-β3, hepatocyte growth factor, epidermal growth factor, and vascular endothelial growth factor expression levels were significantly decreased in the resveratrol -treated groups compared to the ischemia–reperfusion group. Conclusion: The results imply that the positive effects of resveratrol on infla mmato ry-pr oinfl ammat ory cytokine expression may be a major contributor to the anti-oxidant, anti-inflammatory, anti-proliferative, anti-carcinogenic, and therapeutic effects of resveratrol documented in the literature.

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• ArticleYayıncıda açık erişim2023/r/ebyu/13249
  Potentially important markers in thyroid neoplasia: Claudin-1 and MMP-7

  Sayar, I.; Gürbüzel, M.

  Background: Thyroid carcinomas are the most common malignant endocrine tumors, and various immunohistochemical markers are tested in routine practice to reduce diagnostic differences, as well as to elucidate carcinogenesis and detect malignancy. Disruption of basement membranes and the extracellular matrix is an important step in tumor carcinogenesis and progression. The claudin and matrix metalloproteinase families are also thought to be effective in this process. Aim: In this retrospective study, the comparative expression of claudin-1 and MMP-7 immunomarkers in normal tissues and thyroid neoplasia were investigated. Materials and Methods: Immunohistochemical staining was performed for claudin-1 and matrix metalloproteinase 7 (MMP-7) in 112 sections, including 24 follicular adenomas, 22 follicular carcinomas, 24 medullary carcinomas, 24 papillary carcinomas, and 18 single dominant nodules from thyroid lesions. Results: A significant staining difference for claudin-1 was observed in follicular carcinoma and medullary carcinoma, papillary carcinoma, and single dominant nodules compared to normal thyroid tissue. A statistically significant staining difference was observed for MMP-7 in follicular adenoma, medullary carcinoma, and papillary carcinoma compared to normal thyroid tissue. Conclusions: These results indicate that claudin-1 and MMP-7 are important in the diagnosis, differential diagnosis, and carcinogenesis of follicular adenoma, follicular carcinoma, medullary carcinoma, papillary carcinoma, and single dominant nodules.

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• ArticleAçık Erişim2023/r/ebyu/13065
  The effects of sorafenib in healthy and cisplatin-treated rats

  Demirtas, Levent; Gürbüzel, Mehmet; Tahirler, Hilal; Akbas, Emin Murat; Karatas, Ozhan; Arslan, Yusuf Kemal

  Background. Sorafenib is a multikinase inhibitor currently used in the treatment of hepatocellular carcinoma, renal cell carcinoma and thyroid cancer. Objectives. The literature on this agent is scarce. This study aimed to evaluate the effects of sorafenib when administered to both healthy and cisplatin-induced rats. Materials and methods. The animals were divided into 4 groups: 1) control group that received 0.9% saline intraperitoneally (C); 2) group administered a single dose (7 mg/kg) of cisplatin (Cis); 3) a group administered 20 mg/kg of sorafenib for 7 days (Sor); 4) group administered 20 mg/kg of sorafenib followed by 7 mg/kg of cisplatin for 7 days (Cis+Sor). All animals were sacrificed 7 days after the completion of their treatment arm, and serum and tissue samples were taken. Results. Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and interleukin 38 (IL-38) levels were increased in the Sor and Cis+Sor groups compared to the control group. When compared with the control group, serum urea, creatinine, kidney IL-1β, and tumor necrosis factor alpha (TNF-α) levels did not change in the Sor group. When compared to the Cis group, the levels of these parameters decreased in the Cis+Sor group. Conclusions. According to the data obtained, sorafenib caused liver toxicity when given to both healthy and cisplatin-induced rats. While sorafenib did not cause any significant changes in the kidneys when given to healthy rats, it had a healing effect in kidneys after stress induced by cisplatin.

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• ArticleYayıncıda açık erişim2023/r/ebyu/12982
  The Effects of Sunitinib in Healthy and Cisplatin-Induced Rats

  Demirtas, Levent; Gürbüzel, Mehmet; Akbas, Emin Murat; Tahirler, Hilal; Karatas, Ozhan; Kemal Arslan, Yusuf

  Sunitinib is a multitargeted kinase inhibitor that inhibits many receptor tyrosine kinases and has been used in the treatment of gastrointestinal stromal tumors, metastatic renal cell carcinoma, and pancreatic neuroendocrine tumors. In this study, the effects of sunitinib given to rats, both alone and after stress with cisplatin, were investigated. The animals were divided into four groups – (1) control group (C) administered interperitoneally with a single dose 0.9 % saline, (2) Cis group administered a single dose (7 mg/kg) of cisplatin, (3) Sun group administered 10 mg/kg sunitinib for seven days, and (4) Cis+Sun group administered 10 mg/kg sunitinib for seven days after a single dose (7 mg/kg) of cisplatin. After these applications, the rats were sacrificed, and blood and tissue samples were taken for biochemical and histopathological evaluations. Sunitinib did not show any effect on urea, creatine, and kidney IL1β and TGF-β3 expression levels when administered alone; it increased ALT, AST, and IL-38 levels. When sunitinib was given to the cisplatin-induced rats, it was observed that the increase in ALT, AST, and IL-38 levels increased more than the rats that was given only sunitinib. According to the data obtained, sunitinib does not cause a significant change in kidney tissue under both normal and stress conditions, while it creates stress in liver tissue. In addition, its toxicity in the liver becomes more certain as a result of its combination with cisplatin.

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• ArticleYayıncıda açık erişim2022/r/ebyu/13698
  Qualification and quantification of plasma cell-free DNA after long-term storage conditions in patients with benign prostatic hyperplasia (BPH): A pilot study

  Bozkurt, Aliseydi; Gürbüzel, Mehmet; Sayar, Ilyas; Baydeniz, Soner; Arslan, Yusuf Kemal

  Objectives: Free DNA is used as a cancer biomarker due to its low cost, high applicability, and fast, reliable results compared to invasive methods. This study aimed to evaluate the quantification of plasma-free DNA after long-term storage conditions and perform qualification through single nucleotide polymorphism (SNP) screening based on this DNA. Methods: Plasma-free DNA samples were quickly isolated from the peripheral blood of both the benign prostatic hyperplasia (BPH) and control group participants and then maintained at -80 °C for four years. Upon thawing, first, free DNA was purified and fluorometric measurements were taken to determine the amount of DNA. Subsequently, the rs6983267, rs12628, and rs1799939 SNPs were screened in the CCAT2, HRAS, and RET genes, respectively. Results: Significant results were obtained from the fluorometric measurements in terms of single-stranded DNA (ssDNA) (p<0.001). However, there was no significant difference in SNPs rs6983267, rs12628, and rs1799939 in the BPH group compared to the healthy individuals. Conclusions: The data show that fluorometric ssDNA measurements are suitable for quantifying free DNA. The fact that SNP screening can be done successfully in both healthy people and BPH patients suggests that plasma-free DNA can be stored in the laboratory under appropriate conditions.

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