Person: YEGEN, BERRAK
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
YEGEN
First Name
BERRAK
Name
22 results
Search Results
Now showing 1 - 10 of 22
Publication Metadata only Nesfatin-1 treatment preserves antioxidant status and attenuates renal fibrosis in rats with unilateral ureteral obstruction(2022-06-01) ÇETİNEL, ŞULE; YEGEN, BERRAK; KAYA, ÖZLEM TUĞÇE; ÖZBEYLİ, DİLEK; Tezcan N., Özdemir-Kumral Z. N., Yenal N. Ö., Çilingir-Kaya Ö. T., Virlan A. T., Özbeyli D., Çetinel Ş., Yeğen B., Koç M.Background Nesfatin-1 (NES-1), an anorexigenic peptide, was reported to have anti-inflammatory and anti-apoptotic actions in several inflammation models. Methods To elucidate potential renoprotective effects of NES-1, unilateral ureteral obstruction (UUO) was induced in male Sprague Dawley rats by ligating left ureters. The rats were injected intraperitoneally with either saline (SL) or NES-1 (10 mu g/kg/day) for 7 or 14 days (n = 8 in each group). On the 7th or 14th day, obstructed kidneys were removed for the isolation of leucocytes for flow-cytometric analysis and the assessments of biochemical and histopathological changes. Results Opposite to glutathione levels, renal myeloperoxidase activity in the SL-treated UUO group was significantly increased compared with the sham-operated group, while NES-1 treatment abolished the elevation. The percentages of CD8+/CD4+ T-lymphocytes infiltrating the obstructed kidneys were increased in the SL-treated groups but treatment with NES-1 did not prevent lymphocyte infiltration. Elevated tumour necrosis factor-alpha (TNF-alpha) levels in SL-treated UUO group were decreased with NES-1. Although total degeneration scores were similarly increased in all UUO groups, tubular dilatation scores were significantly increased in UUO groups and lowered by NES-1 only in the 7-day treated group. Elevated interstitial fibrosis scores in the SL-treated groups were decreased in both 7- and 14-day NES-1 treated groups, while alpha-smooth muscle actin (alpha-SMA) and apoptosis scores were depressed in both NES-1 treated groups. Conclusion The present data demonstrate that UUO-induced renal fibrosis is ameliorated by NES-1, which appears to involve the inhibition of neutrophil infiltration and thereby amelioration of oxidative stress and inflammation. These data suggest that NES-1 may have a regulatory role in protecting the kidneys against obstruction-induced renal injury.Publication Metadata only Interactions Of Estrogen And Oxytocin Receptors In Colonic Visceral Hypersensitivity Caused By Irritable Bowel Syndrome In Rats(2022-09-01) YILDIRIM, MUSTAFA AKİF; YEGEN, BERRAK; Kahraman M. M. , Mermer K. S. , Aksoy M. B. , Ozden L., Sakalli B. M. , Uludag A., Varol Y., YILDIRIM M. A. , YEGEN B.Publication Open Access The potency of obestatin in improving kidney functions and apoptosis in rats with cisplatin-induced acute kidney injury(2022-01-01) ÖZDEMİR KUMRAL, ZARİFE NİGAR; BULUT, ALİSİNA; ÖZKAN YENAL, NAZİYE; YEGEN, BERRAK; KOÇ, MEHMET; ÖZDEMİR KUMRAL Z. N. , BULUT A., Üzülmez B., Vezirhüyük M., Kök Z., ÖZKAN YENAL N., YEGEN B., KOÇ M.© 2022 Marmara University Press.Cisplatin (CP), which is the most commonly used anticancer agent to treat several solid tumors, may cause acute kidney injury (AKI) as the major limiting factor for its clinical use. Obestatin (OB) is a ghrelin gene-derived peptide produced in several tissues and has shown anti-oxidant, anti-apoptotic, and anti-inflammatory effects in many experimental models. This study investigated the effect of OB treatment on nephrotoxicity induced by CP. Rats were divided into 4 groups as two control (1 ml/kg, saline, intraperitoneal (ip), single dose) and two CP-induced (7 mg/kg, ip, single dose) AKI groups (8 rats in each group). Immediately after the CP injection and the following two days, injections of OB (10 µg/kg, ip) were performed. Rats were decapitated at the end of 72 hours. Blood and kidney tissue samples were taken for biochemical and histopathological measurements. The results of the present study revealed that serum creatinine and BUN levels were significantly increased in the CP-induced AKI group when compared to the control group. Treatment with OB improved kidney functions and ameliorated renal oxidative injury and maintained oxidative balance in the CP-induced AKI model, which was revealed by elevated malondialdehyde and depleted glutathione levels. TUNEL scores also demonstrated that CP increased the apoptotic response, while OB treatment abolished it. CP-induced medullary and cortical injuries were also partially reversed by OB treatment. Thus, our findings show that OB alleviates CP-induced nephrotoxicity in rats through the abolishment of oxidative stress and apoptosis.Publication Open Access Cerrahi menopoz oluşturulmuş sıçanların karaciğer ve böbrek dokularında oksidan/antioksidan dengenin korunmasında egzersizin ve östrojenin yararlı etkileri(2022-09-01) YÜKSEL, MERAL; ERCAN, FERİHA; YILDIRIM, ALPER; YEGEN, BERRAK; Tamer S. A. , Levent N., Yüksel M., Ercan F., Yıldırım A., Yegen B.Amaç: Bu çalışmanın amacı cerrahi olarak menopoz oluşturulan sıçanların böbrek ve karaciğerlerinde gözlenen histopatolojik ve fonksiyonel değişiklikleri ve östrojen veya egzersizin ya da östrojen-egzersiz kombinasyonunun oksidan hasar üzerine etkilerini araştırmaktır.Materyal ve Metot: Anestezi altında Sprague Dawley dişi sıçanlara (n=32) bilateral overiektomi uygulandı ve tüm sıçanlar rastgele olarak iki gruba ayrıldı. Sıçanların yarısına normal içme suyu, diğer yarısının içme sularına östrojen (1mg/kg/gün) eklendi. İki hafta sonra gruplar kendi içlerinde sedanter ve egzersiz (5 gün/hafta, 30 daki-ka, 8 hafta) gruplarına ayrıldı. Deney protokolünün sonun-da serum, karaciğer ve böbrek örnekleri biyokimyasal ve histopatolojik incelemeler için alındı. Femurda da histopa-tolojik değerlendirme yapıldı.Bulgular: Cerrahi olarak menopoz oluşturulan sıçan-larda östrojenin böbrek dokusunda nötrofil infiltrasyonunu ve reaktif oksijen türlerinin üretimini baskılayarak koruyu-cu etki gösterdiği, kemik kütlesinde hafif düzeyde artışa neden olduğu, ancak karaciğerin antioksidan glutatyon düzeyinde azalmaya yol açtığı belirlenmiştir. Buna karşın, östrojen uygulaması menopozda yapılan egzersiz nedeniy-le karaciğerde oluşan oksidan stresi engellemiştir. Egzer-sizle veya egzersize östrojen tedavisinin eklenmesiyle böbrek fonksiyonları önemli ölçüde etkilenmezken, kemik yapısında tek başına östrojene kıyasla daha olumlu deği-şiklikler gözlenmiştir.Sonuç: Östrojen replasmanı kemik dokusundaki olum-lu etkilerinin yanı sıra karaciğer ve böbrekte oksidan stresi azaltmakta ve özellikle karaciğerde egzersize bağlı gelişen oksidan stresi baskılayarak koruyucu etki göstermektedir.Publication Metadata only 83: phoenixin-14 ameliorates cholestatic liver injury and bileinduced acute pancreatic injury in rats(2022-05-01) KAHRAMAN, MERVE MERİÇ; YÜKSEL, MERAL; YEGEN, BERRAK; ERCAN, FERİHA; Şen L. S. , Kahraman M. M. , Mermer K. S. , Köroğlu K., Yüksel M., İmeryüz N., Ercan F., Yegen B.Background: Bile duct obstruction, which results in cholestatic liver injury, is also the major cause of acute pancreatitis. Phoenixin (PNX) was originally defined as a hypothalamic peptide associated with a wide range of physiological processes and exerts antioxidant and antiinflammatory effects. PNX is expressed in several peripheral organs including pancreas and liver. We aimed to evaluate possible therapeutic effects of PNX on hepatic and pancreatic damage induced by biliary or pancreaticobiliary duct obstruction. Methods: In male Sprague Dawley rats, bile duct ligation (BDL; n=16) or pancreaticobiliary duct ligation (PBDL; n= 16) was performed under ketamine anesthesia, while control rats (n=8) had sham-surgery. Either PNX-14 (50 µg/kg/day) or saline was subcutaneously injected immediately after surgery and in the following 2 days. On the post-operative 3rd day, hepatic and renal blood flow was measured using laser Doppler flowmeter under anesthesia and the rats were then euthanized. In the liver and pancreas samples, levels of malondialdehyde, antioxidant glutathione and myeloperoxidase activity were measured by spectrophotometry, while luminol- and lucigenin-enhanced chemiluminescence (CL) levels were measured to assess formation of reactive oxygen species (ROS). Tissue samples were stained by hematoxylin-eosin to calculate microscopic damage scores. Statistical analyses were made by one-way ANOVA. Results: Increased microscopic damage scores in the pancreas of saline-treated PBDL (p<0.001) and in the liver of saline-treated BDL group (p<0.001) were reduced by PNX14 treatment (p<0.01), but PBDL-induced hepatic damage (p<0.001) was not changed by PNX-14. Pancreatic and hepatic levels of malondialdehyde and myeloperoxidase activity and pancreatic glutathione levels were not different among the experimental groups, while hepatic glutathione level was elevated in PNX-14-treated BDL (p<0.001) and PBDL (p<0.01) groups as compared to control group. Despite a non-significant fall in renal or hepatic blood flow in saline-treated BDL rats, PBDL significantly reduced hepatic (p<0.001) and renal (p<0.01) blood flow, while PNX-14 reversed blood flow in both organs back to control levels (p<0.05). The CL levels of luminol and lucigenin were increased in both hepatic and pancreatic tissues of saline-treated BDL and PBDL groups (p<0.05-0.001), showing enhanced ROS generation. However, CL levels in both the liver and pancreas of PNX-14-treated BDL and PBDL groups were significantly reduced as compared to those measured in the liver and pancreas of respective saline-treated groups (p<0.05-0.001). Conclusion: In conclusion, cholestatic liver injury and bile-induced pancreatic injury are alleviated by PNX-14 treatment, which appears to act via its ROS scavenging activity, by replenishing hepatic antioxidant capacity and restoring impaired organ perfusion.Publication Metadata only Güncel farmakoloji fizyoloji temelinde hasta odaklı yaklaşım(Güneş Kitabevi, 2022-10-01) GÖREN, MEHMET ZAFER; YEGEN, BERRAK; OKUYAN, BETÜL; Şener G. (Editör), Gören M. Z. (Editör), Okuyan B. (Editör), Yegen B. (Editör)Publication Open Access Neuropeptide W Exhibits Preventive and Therapeutic Effects on Acetic Acid-Induced Colitis via Modulation of the Cyclooxygenase Enzyme System(2023-01-01) ARABACI TAMER, SEVİL; ERCAN, FERİHA; YEGEN, BERRAK; ARABACI TAMER S., Akbulut S., Erdogan O., Cevik O., ERCAN F., YEGEN B.Background The novel peptide neuropeptide W (NPW) was originally shown to function in the control of feeding behavior and energy homeostasis. The aim of this study was to elucidate the putative preventive and therapeutic effects of NPW on colitis-associated oxidative injury and the underlying mechanisms for its action.Methods Sprague-Dawley rats in the acute colitis groups received NPW (0.5, 1 or 5 mu g/kg/day) injections prior to induction of colitis with acetic acid, while the chronic colitis groups were treated after the induction of colitis. In both acute and chronic colitis (CC) groups, treatments were continued for 5 days and the rats were decapitated at the 24th hour of the last injections and colon tissues were collected for assessments.Results NPW pretreatment given for 5 days before colitis induction, as well as treating rats with NPW during the 5-day course of CC, abolished colonic lipid peroxidation. NPW treatment prevented colitis-induced reduction in blood flow, diminished neutrophil infiltration, and pro-inflammatory cytokine responses. NPW pretreatment only at the higher dose reduced colonic edema and microscopic score and preserved colonic glutathione stores. Elevations in cyclooxygenase (COX) enzyme activity and COX-1 protein level during the acute phase of colitis as well as reduction in COX-2 were all reversed with NPW pretreatment. In contrast, NPW treatment was effective in reducing the elevated COX-2 concentration during the chronic phase.Conclusions NPW alleviates acetic acid-induced oxidative colonic injury in rats through the upregulation of colonic blood flow as well as the inhibition of COX-2 protein expression and pro-inflammatory cytokine production.Publication Metadata only Stimulation of estrogen receptors attenuates oxidant skin injury in hyperglycemic rats with incisional wound(2023-01-01) KAHRAMAN, MERVE MERİÇ; YÜKSEL, MERAL; ERCAN, FERİHA; YEGEN, BERRAK; Sen L. S., Akgun T., KAHRAMAN M. M., YÜKSEL M., ERCAN F., YEGEN B.Publication Open Access Rethinking large group lectures – how far in this format(2022-05-01) SEVİM, MUSTAFA; ERZİK, CAN; YEGEN, BERRAK; GÜLPINAR, MEHMET ALİ; AKTURAN S., SEVİM M., ERZİK C., YEGEN B., GÜLPINAR M. A.Objective: The aim of this study is to determine the perceptions, attitudes, and behaviour of medical students and lecturers regarding the lectures and their effects on students’ learning behaviour. Materials and Methods: This was a qualitative study including multi-methods. Researchers observed lecture ambiance and activities in two courses. Lectures were observed and slide-presentations were evaluated. Additionally, in-depth and focus group interviews were conducted. Results: Two researchers attended and observed 75 lectures. The average number of attendees was 51.21. Eighty percent of lecturers did not introduce any activities to attract attention and prepare students for the lecture. Only 12% of lectures were taught interactively. Of the evaluated 43 (69.80%) slide-presentations, sufficient association or integration was not made between clinical and basic sciences. Conclusion: This study revealed that the lectures created negative feelings and thoughts in students and lecturers, and led to undesirable attitudes and behaviour. It is essential to focus on giving interactive lectures which aim at developing reasoning, decision-making, and evaluation competencies. The most significant factors determining students’ attendance and appraisal of the lectures were related to the preparation of the lecturers, the intensity of the content, integration between basic science and clinical science, and the presentation skills.Publication Metadata only Investigation of the possible protective effect of phoenixin-14 on small intestine and lung damage due to mesenteric ischemia in rats(2023-01-01) KAHRAMAN, MERVE MERİÇ; YÜKSEL, MERAL; ERCAN, FERİHA; YEGEN, BERRAK; YEGEN, ŞEVKET CUMHUR; Sen L. S., Kahraman M. M., Mermer K. S., Akgun T., YÜKSEL M., ERCAN F., YEGEN B., Yegen C.
- «
- 1 (current)
- 2
- 3
- »