Browsing by Author "Oguztuzun, Serpil"

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The Activities of Gst Isozymes in Stomach Tissues of Female Obese Patients
(Walter de Gruyter Gmbh, 2020) Yilmaz, Can; Bulus, Hakan; Oguztuzun, Serpil; Cihan, Mehmethan; Fidan, Ceylan
Objectives: Obesity has become an important public health problem because of its increasing prevalence and relation with many diseases and mortality. Studies have shown its association with oxidative stress. In this study, the effect of obesity on total amount of thiol and some glutathione S-transferase (GST) isozymes were investigated which could serve as an important criteria in dose adjustment of some certain drugs in obese. Methods: The gastric tissues removed by gastrectomy operation from 29 morbid obese female patients were analysed for thiol levels and activities of total GST, GSTT1-1 and GSTM1-1. Patients were grouped according to age, presence of hypertension and/or diabetes, and family history. Results: The average total thiol was 131.22 (+/- 7.74) nmol/mg protein with no significant differences in between the groups. GSTT1 specific activities were about 20% higher in four groups: with ages over 35 years old, with hypertension, without diabetes and finally without family history, with respect to other groups. The differences between total GST and GSTM1 activity levels of experimental groups were not significant. Conclusions: This is the first study to compare activities of GST isozymes and total thiol content in the stomach tissues of obese female patients accompanying some common metabolic disorders, age and family history.
Biochemical and Histopathologic Assessment of Effects of Acitretin on Epiphyseal Growth Plate in Rats
(Termedia Publishing House Ltd, 2020) Onder, Sevda; Bilgili, Serap Gunes; Bulut, Gulay; Celik, Huseyin Tugrul; Oguztuzun, Serpil; Onder, Haci; Karadag, Ayse Serap
Introduction: Acitretin is a commonly used retinoid in dermatology. Although there are generally known side effects, the effects on the epiphyseal plaque and bone metabolism are not clear in the literature. Aim: To histopathologically investigate the effects on the epiphyseal plate and assess variations in bone metabolism caused by acitretin. Material and methods: Three groups were formed with 10 rats in each group. The 1st group (n = 10, 5 male, 5 female) were administered 10 mg/kg/day oral acitretin solution and the 2nd group (n = 10, 5 male, 5 female) were administered 3 mg/kg/day oral acitretin solution. The control group were given normal standard feed and water. Rats were sacrificed at the end of 4 weeks. The proximal tibias were excised and histopathologically and immunohistochemically assessed. Biochemical assessment was also carried out. Results: Staining with haematoxylin-eosin found reductions in the epiphyseal plate in the 1st and 2nd group compared to the control group, though this situation was not statistically significant. Immunohistochemical studies did not encounter Type II collagen in the epiphyseal bone, proliferative zone and hypertrophic zone in the control group, low dose acitretin solution group and high dose acitretin solution group. Type II collagen was not observed in osteoids and osteoblasts. Type I collagen was not observed in the hypertrophic zone and proliferative zone of any group. Conclusions: Our data show that though acitretin caused degeneration of the epiphyseal plate, it did not cause clear thinning and we identified no significant variations in bone metabolism markers.
Describing the Expression Profiles of Glutathione S-Transferase Mu and Tumor Protein 53 in Brain Tumor Tissue
(Erciyes Univ Sch Medicine, 2024) Dirican, Onur; Kaygin, Pinar; Lti, Sezen Yilmaz Saria; Yilmaz, Can; Simsek, Gulcin; Oguztuzun, Serpil; Izci, Yusuf
Objective: This study aims to explore the expression profiles of the glutathione S-transferaseMu (GST-M) isozyme and tumor protein 53 (p53) in both healthy and tumorous brain tissues. The findings are compared with clinical features and lifestyle factors to identify potential associations or correlations. Materials and Methods: We retrospectively analyzed the medical records of 149 patients diagnosed with primary or metastatic intracranial tumors. The expression levels of GST-M and p53 proteins were assessed in healthy and tumorous brain tissues using immunohistochemical staining. We also evaluated the associated clinical features and lifestyle factors. Results: There was a significant difference in the expression levels of GST-M between tumorous and healthy brain tissues, with tumor tissues showing higher expression (p<0.0001). Conversely, robust p53 expression was absent in both normal (97.3%) and tumor (78.5%) tissues. Nevertheless, a significantly higher prevalence of samples with p53 expression was found in the tumor group (p<0.0001). No associations were found between expression levels and clinical features or lifestyle risk factors. Furthermore, GST-M and p53 expression did not impact postoperative survival rates. Conclusion: The findings indicate an elevated expression of GST-M in brain tumor tissues, suggesting a potential role for GST-M in brain tumorigenesis.
Effects of Different Doses of Systemic Isotretinoin on Eyes: a Histopathological and Immunohistochemical Study in Rats
(Lippincott Williams & Wilkins, 2020) Karadag, Remzi; Karadag, Ayse Serap; Ozlu, Emin; Oguztuzun, Serpil; Simsek, Gulcin Guler; Esmer, Oktay; Bilgili, Serap Gunes
Purpose: To evaluate ocular side effects associated with systemic isotretinoin histopathologically. Methods: In this multicenter study, a total of 15 male and 15 female rats were randomly divided into 3 equal groups according to the oral dose of isotretinoin they were administered: 0 mg/kg/d (group A), 7.5 mg/kg/d (group B), and 15 mg/kg/d (group C). Biopsy specimens were taken from the globe conjunctiva, cornea, and eyelid conjunctiva. Expression levels of human beta-defensin-1, human beta-defensin-2, toll-like receptor (TLR)-2, and TLR-4 were evaluated by immunohistochemical methods. Results: The number of goblet cells in eyelid conjunctiva was significantly lower in group B than that in group A and group C (P = 0.002). The sizes of meibomian gland acini were significantly smaller in group B and group C than those in group A (P < 0.001). Fibrosis of eyelid conjunctiva was significantly higher in group C and group B than that in group A (P = 0.002). The levels of staining of TLR-4 in the cornea with group B were significantly lower compared with group C (P = 0.035). Conclusions: Our study suggests that isotretinoin in the early period affects eyelid conjunctiva and meibomian glands without affecting the globe conjunctiva and cornea. Occurrence of the initial symptoms of isotretinoin on the eyelids, especially on the meibomian glands, suggests that the symptoms of patients occur because of evaporative dry eye.
Expressions of Glutathione S-Transferase Alpha, Mu, Pi, and Theta in the Skin Samples of Patients With Acne Rosacea
(Wiley, 2020) Takci, Zennure; Bilgili, Serap Gunes; Kilic, Murat; Oguztuzun, Serpil; Bozer, Busra; Simsek, Gulcin Guler; Karadag, Ayse Serap
Background Data point to the importance of oxidative stress in rosacea. Glutathione S-transferases (GSTs) have substantial roles in a wide variety of oxidative stress-related conditions. Aim To evaluate the immunohistochemical staining characteristics of GST alpha (GSTA), mu (GSTM), pi (GSTP), and theta (GSTT) in patients with rosacea. Patients/Methods The study included 23 women and 7 men with rosacea (mean +/- SD age 49 +/- 11 year) and 15 healthy control subjects (10 women, 5 men; mean +/- SD age 47.86 +/- 10.88 year). For each patient, the average disease duration, disease subtype, ocular involvement, and severity score were recorded. A 3-mm punch biopsy was taken from the facial skin of each patient and control. Expression of GST isoenzymes was analyzed immunohistochemically. Results Expressions of GSTM1, GSTP1, and GSTT1 were significantly elevated in patients with rosacea compared to those in the control group (P = .0001,P = .0002,P < .0001, respectively). In the rosacea group, GSTT1 expression was significantly stronger than GSTP1 and GSTA1 expressions (P = .019,P < .0001, respectively). There were no significant associations between expressions of GST isoenzymes and gender, age, average duration of illness, disease subtype, ocular involvement, or severity score in the patient group (allP > .05). Conclusions In rosacea, the significant increase of GSTT1, GSTP1, and GSTM1 expressions might result from activation of GST as an outcome of extreme free radical generation from triggered neutrophils or ultraviolet vulnerability. These findings support the relevance of oxidant stress in the pathogenesis of rosacea.
Glutathione S-Transferase Enzyme Activity and Protein Expression in Patients With Recurrent Tonsillitis and Idiopathic Tonsillar Hypertrophy
(Palacky Univ, Medical Fac, 2019) Aydin, Sedat; Demir, Mehmet Gokhan; Oguztuzun, Serpil; Kilic, Murat; Yilmaz, Can; Dirican, Onur
Objectives. The palatine tonsil is a significant part of the secondary immune system. Tonsillitis and idiopathic tonsillar hypertrophy (ITH) are the most common pathologies of this component. Although there are studies on their pathogenesis, there is insufficient study of the role of antioxidant agents. Glutathione S-transferase (GST) isozymes contribute to the antioxidation reactions in the tissue via the glutathione pathway. The purpose in this study was to reveal the levels of the GST enzyme activity and protein expression of GSTP1 and GSTA1 isozymes in patients with tonsillitis and tonsil hypertrophy, and to investigate their role in the pathogenesis of these diseases. Materials and Methods. Sixteen patients with recurrent tonsillitis and 5 patients with ITH and were included in the study. Cytosolic extracts were prepared from post-tonsillectomy tissues of both patient groups and GST enzyme activities were measured. Results. The expression of GSTP1 was found to be significantly higher than GSTA1 in tissue samples of patients with ITH and recurrent tonsillitis (P<0.001). Increased GST activity and GSTP1 isozyme expression were shown in patients with recurrent tonsillitis compared to the idiopathic tonsillar hypertrophy study group.There was a positive correlation between the expressions of GSTP1 (P=0.040; r=0.47). Conclusion. Increased GST activity and GSTP1 isozymes were demonstrated histologically in the pathogenesis of ITH and recurrent tonsillitis. We believe that the data of changes in antioxidant capacity, obtained from studies with more extensive and larger samples, would support our findings.
An Investigation of Cytochrome P450 (Cyp) and Glutathione S-Transferase (Gst) Isoenzyme Protein Expression and Related Interactions With Phototherapy in Patients With Psoriasis Vulgaris
(Wiley-blackwell, 2017) Karadag, Ayse S.; Uzuncakmak, Tugba K.; Ozkanli, Seyma; Oguztuzun, Serpil; Moran, Busra; Akbulak, Ozge; Akdeniz, Necmettin
Oxidative stress may play an important role in the pathogenesis of psoriasis. Glutathione S-transferases (GSTs) make up a group of antioxidant enzymes. Cytochrome p450 (CYP) enzymes can influence oxidation and reduction reactions. We investigated the potential effects of GST and CYP enzymes in the pathogenesis of psoriasis. The study included 32 psoriasis patients and 22 healthy subjects. Psoriasis patients were administered 20 sessions of narrowband ultraviolet B phototherapy. Expressions of GST and CYP enzymes were assessed by immunohistochemical staining. Expression levels of GSTK1, GSTM1, and GSTT1 were significantly higher in psoriasis than in control tissues (P = 0.022, P = 0.001, and P = 0.006, respectively). Pre- and post-treatment expression was similar. Expression of CYP1A1 and CYP2E1 was significantly higher in pre- (P = 0.003 and P = 0.001, respectively) and post-treatment (P = 0.003 and P = 0.001, respectively) psoriatic tissues than in control tissues. No significant differences in CYP1B1 levels between the study and control groups were detected before treatment (P > 0.05). However, CYP1B1 levels were higher in post-treatment psoriatic tissue than in control tissue (P = 0.045). The significant increases in expression of GSTK1, GSTM1, and GSTT1 in psoriasis may reflect the increased activation of GST in response to excessive free radical formation from activated neutrophils or ultraviolet exposure to maintain antioxidant capacity in psoriasis. Furthermore, expressions of CYP1A1 and CYP2E1 represent important enzymatic systems in psoriasis. These findings suggest that psoriasis is an oxidative stress condition, although phototherapy does not affect these enzymatic systems. Further investigation is required.
Obezite Duyarlılığında Cyp1a1 ve Cyp1b1 Ekspresyonlarının Rolünün Araştırılması
(2022) Yilmaz-sarialtin, Sezen; Dirican, Onur; Kaygin, Pinar; Polat, Fatih; Yılmaz, Can; Bulus, Hakan; Oguztuzun, Serpil
Metabolik işleyiş, etkileri ve neden olduğu hastalıklar açısından daha multidisipliner bir bakış açısıyla anlaşılması gereken obezite, son yıllarda prevalansı ve insidansı artan hastalıklardan biri olarak görülmektedir. Bu hastalığın metabolic yolunda önemli enzim gruplarından biri olan sitokrom p450 (CYP1A1 ve CYP1B1) izozimlerinin rolünün ortaya konulması amaçlanmıştır. 2017-2019 yılları arasında Ankara Keçiören Eğitim ve Araştırma Hastanesi Genel Cerrahi Kliniği'nde obezite tanısı konulan ve bariatric cerrahi, ksenobiyotik metabolizması uygulanan 152 hastaya immünohistokimya yöntemiyle CYP1A1 ve CYPB1 izoenzimlerinin ekspresyonu araştırılmıştır. CYP1A1 açısından elde edilen bulgular; 152 kişide CYP1A1 ve CYP1B1 immünohistokimya boyama düzeyleri incelenen dokuların %12.7'sinde CYP1A1 ekspresyonu gözlenmezken; %33.3, %32.5 ve %21.4'te zayıf bir CYP1A1 ifadesi gözlenmiştir. Dokuların %71.4'ünde CYP1B1 ekspresyonu görülmezken, dokuların %28.6'sında zayıf ekspresyon izlenmiştir. Hiçbir dokuda orta veya güçlü CYP1B1 ekspresyonu gözlenmemiştir. Kadın hastalardan alınan dokuların ortalama CYP1A1 ve CYP1B1 boyama seviyeleri erkek hastalardan daha yüksek bulunmuştur. Klinik verilerden diyabet parametresi (p<0.05) ile anlamlı olduğu gözlenmiştir. Çalışmamızda elde edilen veriler ışığında obez hastalarda anlamlı CYP1A ve CYP1B1 ekspresyonları gözlenmiş ve detoksifikasyon mekanizması nedeniyle antioksidan metabolizma ve işlevsellik mevcuttur. Obez hastalarda bu enzim düzeyindeki artışın özellikle moleküler yolakta başka çalışmalarla aydınlatılması gerektiği ve benzer çalışmalara yol göstereceği düşünülmektedir.
Unveiling the Etiological Impact of Gst-M1, Gst-T1, and P53 Genotypic Variations on Brain Carcinogenesis
(Springer, 2024) Dirican, Onur; Kaygin, Pinar; Oguztuzun, Serpil; Husseini, Abbas Ali; Sarialtin, Sezen Yilmaz; Yilmaz, Can; Izci, Yusuf
Background Functional variants of glutathione-S-transferase (GST)-M1, GST-T1, p53 might modulate brain cancer risk by altering the rate of metabolism and clearance of carcinogens from the brain tissue. In this study, the role of GST-M1, GST-T1, p53 polymorphisms on brain tumor was investigated.Methods and results Brain tumor tissues of 143 patients were obtained from the Gulhane Training and Research Hospital, Department of Neurosurgery between 2019 and 2020. In the xenobiotic mechanism, the null allele frequency in the GST-T1, GST-M1 gene regions of Phase II enzymes by qPCR method were investigated. Single nucleotide polymorphism encoding Arg/Pro conversion in the p53 gene region was analyzed in 120 cases by sequence analysis method. The data were analyzed statistically with patient's demographic and clinical data. GST-M1, GST-T1, p53 genotypes of the patient group were determined. The most frequent genotype was null genotype (0/0) for GST-M1 (chi(2) = 39.756, p < 0.001). GST-M1 genotype frequencies were 30.8%, 23.1%, 44.3% for 1/1, 1/0, 0/0, respectively. The most frequent genotype was GST-T1 1/1 following by GST-T1 1/0 (chi(2) = 0.335, p = 0.846). GST-T1 genotype frequencies were 64.3%, 30.8%, 4.9% for 1/1, 1/0, 0/0, respectively. GST-M1 null genotype might be associated with the development of brain tumors. Genotype distribution obtained in p53 exon 4 codon 72; Arg/Arg was determined as 31 (25.8%), Arg/Pro 70 (58.3%), and Pro/Pro 19 (15.8%) in the case group, while there were 18 (38.3%), 23 (48.9%), and 6 (12.8%) respectively in the control group. However, the genotype distribution of p53 exon 4 codon 72 among tumorous tissue did not significantly vary from healthy control tissues (chi(2)=2.536, p = 0.281).Conclusion The null allele frequency encountered in the GST-M1, GST-T1 gene regions is consistent with the rates in the gene pool called Caucasian in the literature. GST-M1 gene polymorphism may play a crucial role in brain carcinogenesis in Turkish patients. This study based on clinical data is thought to help to understand the important epidemiological features of brain tumors.