Person:
YÜKSEL, MERAL

Organizational Units

Organizational Unit

Sağlık Hizmetleri Meslek Yüksekokulu

Last Name

YÜKSEL

First Name

MERAL

Full item page

Search Results

Now showing 1 - 8 of 8

Open Access
Vitamin D receptor and estrogen receptor gene polymorphisms in men with type 2 diabetes: Effects on Bone Metabolism
(2022-12-01) ÜSTAY, ÖZLEM; YAVUZ, DİLEK; YÜKSEL, MERAL; YAVUZ D., YÜKSEL M., Sancak S., Yazici D., ÜSTAY Ö., Deyneli O., Akalin S.
Purpose There is an increased fracture risk in type 2 diabetes mellitus [DM] patients independent of bone mineral density [BMD], both in men and women. Estrogen receptor [ER]-alpha and vitamin D receptor [VDR] gene polymorphisms may predispose patients to increased osteoporosis and fracture risk. This study aims to analyze the relationship of the ER-alpha gene and VDR gene polymorphisms with indicators of bone turnover and BMD in male type 2 diabetic patients. Methods Type 2 diabetic men diagnosed with diabetes for at least one year and healthy controls were included in this cross-sectional study. BMD was measured by dual X ray absorptiometry. Gene polymorphisms were evaluated with polymerase chain reaction-restriction length polymorphism. Serum iPTH, calcium, beta-CrossLaps (cTx), osteocalcin, and free testosterone levels were also evaluated. Results Participants were 141 type 2 diabetic men [55 +/- 8 years] and 100 healthy controls [53 +/- 7 years]. BMD measurements were not statistically different between the groups. While iPTH [p < 0.05] and serum calcium levels [p = 0.03] were higher in men with type 2 DM; beta-CrossLaps [p = 0.0001], osteocalcin [p = 0.005], and free testosterone [p = 0.04] were lower than controls. The differences in terms of the frequencies of VDR Apa, Taq, Bsm, Fok and ER-alpha polymorphisms were not statistically significant between the groups. No relationship was observed between polymorphisms and BMD in both groups. Conclusions VDR and ER-alpha gene polymorphisms seem to have no effect on BMD and bone turnover in men with DM.
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.
Open Access
Nephroprotective effect of aloe vera extract with regulation of oxidative stress, apoptosis and aquaporin 3 expression levels in streptozotocin induced iabetic rats
(2023-01-01) YÜKSEL, MERAL; Seker U., Guzel B. C., Sener-Akcora D., Baygeldi S. B., YÜKSEL M., Unay-Demirel O., Soker S.
Objective: In this study we examined the protective activity of Aloe vera with considering antioxidant, anti-apoptotic properties, and the status of Aquaporin 3 (AQP3) channel protein. Material and Method: Twenty-one adult female rats were divided into three groups (n=7); Control, Diabetes, Treatment. Control group did not expose to any application. Animals in Diabetes and Treatment were exposed to experimental diabetes with administration of streptozotocin. Rats in Treatment received 300 mg/kg Aloe vera extract daily for 14 days. Rats were sacrificed and kidney samples were used for analyses. Result and Discussion: Analyses indicated that lowest malondialdehyde (MDA) and luminol levels in control group were increased significantly (P<0.05) in diabetic animals. Severe pathological changes observed in Diabetes group while microscopic examinations. Bax, Caspase-3 and apoptotic index (AI) were elevated significantly (P<0.05) in this group compared to Control. Oxidative stress, apoptotic protein expression levels and TUNEL Assay positive cell ratio were down-regulated in Treatment group. When AQP3 levels were measured, immunopositivity reduced significantly (P<0.05) in cortical kidney of Diabetes group which is normalized significantly in Treatment group.This study reporting anti-diabetic potency of Aloe vera extract has capability to avoid streptozotocin induced diabetic renal injury via regulating anti-apoptotic and anti-oxidant cellular signaling. Furthermore, Aloe vera consumption in diabetes might regulate AQP3 levels. Although we observed promising results, more studies are required to explore anti-diabetic, anti-hyperglycemic and nephroprotective activity of Aloe vera.
Open Access
Paraoxonase-1 and fetuin-A levels in children with cerebral palsy
(2022-01-01) YÜKSEL, MERAL; Unay Demirel O., Gungor O., Ignak Tarlig S., YÜKSEL M.
Background/aim: Studies mostly focused on risk factors and clinical status in children with cerebral palsy (CP). Various antiinflammatory markers may help us in the early diagnosis and clinical classification of cerebral palsy patients. In this study, the relationship between antiinflammatory marker levels and clinical status in patients with CP is determined. It is the first time that Fetuin-A and Paraoxonase-1 (PON-1) are examined in children with CP. Materials and methods: The study is conducted on 79 children which are divided into two groups as CP and control. Gross motor function and spasticity are evaluated in addition to biochemical parameters. Results: There is a statistically significant difference between CP and control group in terms of PON-1 activity, high sensitive C-Reactive Protein, HDL, and total cholesterol levels. There is no statistically significant difference in Fetuin A levels between the two groups. Conclusion: In suspected CP patients less than 24 months of age who possess prenatal and postnatal risk factors, the determination of PON-1 activity can be considered as a biomarker to support early diagnosis.
Open Access
Anti-inflammatory, antioxidant and neuroprotective effects of niacin on mild traumatic brain injury in rats
(2023-01-01) KOYUNCUOĞLU, TÜRKAN; AKAKIN, DİLEK; ERZİK, CAN; YÜKSEL, MERAL; YEGEN, BERRAK; Ozaydin D., Bektasoglu P. K., Koyuncuoglu T., Ozkaya S. C., Koroglu A. K., AKAKIN D., ERZİK C., YÜKSEL M., YEGEN B., Gurer B.
AIM: To study the effects of niacin, a water-soluble vitamin, on inflammation, oxidative stress and apoptotic processes observed after mild traumatic brain injury (TBI). MATERIAL and METHODS: A total of 25 Wistar albino male rats were randomly divided into control (n=9), TBI + Placebo group (n=9), TBI + niacin (500 mg/kg; n=7) groups. Mild TBI was performed under anesthesia by dropping a 300 g weight from a height of 1 meter onto the skull. Behavioral tests were applied before and 24 hours after TBI. Luminol and lucigenin levels and tissue cytokine levels were measured. Histopathological damage was scored in brain tissue. RESULTS: After mild TBI, luminol and lucigenin levels were increased (p<0.001), and their levels were decreased with niacin treatment (p<0.01-p<0.001). An increased score was obtained with trauma in the tail suspension test (p<0.01), showing depressive behavior. The number of entries to arms in Y-maze test were decreased in TBI group compared to pre-traumatic values (p<0.01), while discrimination (p<0.05) and recognition indices (p<0.05) in object recognition test were decreased with trauma, but niacin treatment did not change the outcomes in behavioral tests. Levels of the anti-inflammatory cytokine IL-10 were decreased with trauma, and increased with niacin treatment (p<0.05). The histological damage score was increased with trauma (p<0.001), and decreased with niacin treatment in the cortex (p<0.05), and hippocampal dentate gyrus region (p<0.01). CONCLUSION: Niacin treatment after mild TBI inhibited trauma-induced production of reactive oxygen derivatives and elevated the anti-inflammatory IL-10 level. Niacin treatment ameliorated the histopathologically evident damage.
Open Access
Nesfatin-1 ameliorates oxidative brain damage and memory impairment in rats induced with a single acute epileptic seizure
(2022-04-01) ARABACI TAMER, SEVİL; KOYUNCUOĞLU, TÜRKAN; AKAKIN, DİLEK; YÜKSEL, MERAL; YEGEN, BERRAK; Arabacı Tamer S., Koyuncuoğlu T., Karagöz Köroğlu A., AKAKIN D., YÜKSEL M., YEGEN B.
© 2022Aims: We aimed to investigate putative neuroprotective effects of nesfatin-1 on oxidative brain injury and memory dysfunction induced by a single epileptic seizure and to compare these effects with those of antiepileptic phenytoin. Main methods: Wistar albino rats were randomly divided into a control group and pentylenetetrazole (PTZ)-seizure groups pretreated intraperitoneally (ip) with saline or nesfatin-1 (NES-1; 0.3, 1 or 3 μg/kg/day) or phenytoin (PHE; 40 mg/kg/day) or PHE + NES-1 (0.3 μg/kg/day) at 30 min before the single-dose PTZ injection (45 mg/kg; ip). All treatments were repeated at the 24th and 48th h of the provoked epileptic seizure. Passive-avoidance test was performed to assess memory function. The rats were decapitated at the 72nd hour of seizures and brain tissues were analyzed for histopathological changes and for measuring levels of malondialdehyde, glutathione, myeloperoxidase activity and reactive oxygen/nitrogen species. Key findings: In parallel to the effects of phenytoin, NES-1 reduced seizure score, elevated antioxidant glutathione content, depressed generation of nitric oxide and protected against seizure-induced neuronal damage. Additionally, increased malondialdehyde levels and elevated glial fibrillary acidic protein immunoreactivity in the cortex and hippocampus were decreased and memory dysfunction was improved by NES-1. However, NES-1 had no impact on myeloperoxidase activity or production of reactive oxygen species in the brain. Significance: The findings of the present study demonstrate that nesfatin-1 treatment provides neuroprotection against seizure-induced oxidative damage and memory dysfunction by inhibiting reactive nitrogen species and upregulating antioxidant capacity, indicating its potential in alleviating memory deficits and increasing the effectiveness of conventional anti-convulsant therapies.
Open Access
Targeting soluble guanylate cyclase with Riociguat has potency to alleviate testicular ischaemia reperfusion injury via regulating various cellular pathways
(2022-12-01) YÜKSEL, MERAL; Seker U., Kavak D. E. , Guzel B. C. , Baygeldi S. B. , YÜKSEL M., Unay Demirel O., Irtegun Kandemir S., Sener D.
© 2022 Wiley-VCH GmbH.Testicular ischaemia reperfusion (I/R) injury results with serious dysfunctions in testis. This study aims to explore effects of soluble guanylate cyclase (sGC) stimulator Riociguat on experimental testicular I/R injury in rats. Twenty-one male rats were divided into three groups (Control, IR and IRR). The control group was not exposed to any application. Bilateral testis from IR and IRR animals were rotated 720° in opposite directions for 3 h to induce experimental testicular ischaemia. Animals in IR and IRR groups were subjected to 3 h of reperfusion. Isotonic and Riociguat were administered to the animals 30 min prior reperfusion by oral gavage. At the end of experiment, animals were sacrificed and tissue samples were used for analyses. Riociguat treatment significantly decreased tissue malondialdehyde and Luminol levels compared to the IR group (p < 0.05). The pathological changes, pro-apoptotic proteins (Bax, Caspase 3, and Caspase 9) and apoptotic index in the IR group were down regulated in Riociguat treated animals (p < 0.05). Riociguat treatment was also significantly increased anti-apoptotic Bcl-2 expression, but alleviated tissue injury via modulating pro-inflammatory cytokine IL-1β levels and significantly (p < 0.05) down-regulating NF-κB activity. Moreover, mTOR and ERK phosphorylation increased in IR group (p < 0.05), but Riociguat treatment reduced protein phosphorylation. Our experiment indicated that targeting sGC might support surgical interventions in testicular I/R injury by modulating oxidative stress, inflammation, and apoptotic protein expression levels, but more detailed studies are required to explore the protective activity of Riociguat and underlying mechanisms in testicular I/R injury.
Open Access
A 10-day mild treadmill exercise performed before an epileptic seizure alleviates oxidative injury in the skeletal muscle and brain tissues of the rats
(2022-01-01) KAYA, ÖZLEM TUĞÇE; YEGEN, BERRAK; YÜKSEL, MERAL; YILDIRIM, ALPER; Arabaci -Tamer S., KAYA Ö. T., YÜKSEL M., YILDIRIM A., YEGEN B.
© 2022 Marmara University Press, All Rights Reserved.Objective: Epileptic seizures may cause skeletal muscle injury and memory dysfunctions. The present study was aimed to investigate the possible protective effects of exercising prior to seizure on seizure-induced oxidative injury in the skeletal muscle and brain. Materials and Methods: Sprague-Dawley male rats were assigned as non-exercise (n=16) and exercise groups (n=16). Following a 3-day exercise training, exercise protocol (30 min) was performed on a treadmill for 10 days, while control rats had no exercise. On the 11th day, the epileptic seizure was induced by a single intraperitoneal injection of pentylenetetrazol (PTZ) (45 mg/kg), while the control groups were injected with saline. Passive-avoidance test was initially performed before PTZ/saline injection and repeated 72 h later for the assessment of memory function. Brain and gastrocnemius muscles were taken for histological assessments and to determine the levels of malondialdehyde (MDA) and glutathione (GSH), myeloperoxidase (MPO) activity and luminal – and lucigenin – enhanced chemiluminescence levels. Results: Exercise training alone increased the formation of reactive oxygen species and elevated the antioxidant GSH capacity of the muscle tissue in the control rats, but these effects were not observed in the muscles of the exercised rats induced with a PTZ-seizure. On the other hand, short-term exercise alone had no effect on the basal oxidative parameters of the brain tissues. Prior exercise did not alter the average seizure scores or memory performances when compared to non-exercised groups, but suppressed the PTZ-induced elevations in MDA and chemiluminescence levels as well as MPO activity in the brain. Conclusion: A 10-day mild treadmill exercise reduced the oxidative brain damage due to a single seizure-induced excitotoxicity and exerted a preconditioning effect on the skeletal muscles exposed to tonic-clonic contractions.