Gülnur Kızılay Özfidan - Academia.edu (original) (raw)

Papers by Gülnur Kızılay Özfidan

International Journal of Neuroscience, Dec 27, 2023

DergiPark (Istanbul University), Feb 1, 2007

Endometriosis is a common gynecologic disorder characterized by the presence of endometrial tissu... more Endometriosis is a common gynecologic disorder characterized by the presence of endometrial tissue outside the uterine cavity. Nearly more than a century has passed since the first description of endometriosis by Von Rokitansky in 1860 but our current understanding of the pathogenesis of the disease still remains unclear. Endometriosis is one of the leading causes of disability among reproductive age women and represents a major personal and public health ‹mplantasyon, embriyonun endometriuma yerleflmesinin gerçekleflti¤i kompleks bir ifllemdir. ‹nsan endometriumu; endometrial hücreler ve embriyodan kaynaklanan steroid hormonlar ve parakrin faktörlerin etkisi al-t›nda, luteal faz süresince embriyoyu kabul etmeye ha-z›r hale gelir. Lösemi inhibitor faktör (L‹F) ve interlökin (‹L)-11'de dahil olmak üzere, pek çok parakrin faktör implantasyonu etkiler. Bunun yan›s›ra endometriyumda geliflen pinopodlar, integrinler, HOX genleri ve ayn› zamanda oosit kalitesi de implantasyon sonucunu belirler. Endometriosis; yayg›n bir jinekolojik hastal›kt›r ve infertil kad›nlar›n yaklafl›k %25-50'si endometriosislidir. ‹nfertiliteye sebep olan mekanizmalar tam olarak anla-fl›lamam›fl olmas›na ra¤men, bu konu hakk›ndaki genel kan›; normal olmayan folikülogenez, sperm disfonksiyonu, implantasyon baflar›s›zl›¤›, erken dönem embriyo geliflimine karfl› oluflan toksisite, implante olma yetene¤i azalm›fl düflük oosit kalitesinin baz› endometriosisli hastalarda infertiliteye neden olan etkili faktörler olabilece¤i yönündedir.

Reproductive Sciences, Dec 1, 2007

Many chemokines likely contribute to the pathogenesis of endometriosis. The authors hypothesize t... more Many chemokines likely contribute to the pathogenesis of endometriosis. The authors hypothesize that the broad-spectrum chemokine inhibitor NR58-3.14.3 may prevent ectopic human endometrium implantation and growth. After placing human endometrium fragments into the peritoneal cavity, ovariectomized athymic nude mice (n = 31) receiving intramuscular estradiol valerate were randomly assigned to daily intraperitoneal injections of either phosphate-buffered saline or NR58-3.14.3. Fourteen days later, the implant number and volume, proliferating cell nuclear antigen (PCNA) and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) index, and MTT cell viability were assessed in the implants. NR58-3.14.3 reduced the total number (45%) and total volume (81%) of endometriotic lesions (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .05) and revealed a lower PCNA and higher TUNEL index in ectopic implants compared with controls (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .05). NR58-3.14.3 treatment did not affect endometrial cell proliferation in vitro. NR58-3.14.3, by possibly regulating cell survival, can reduce the number and size of ectopic implants in vivo, supporting the potential use of chemokine inhibitors in novel therapies for endometriosis.

Biotechnic & Histochemistry, 2018

Increased reactive oxygen species (ROS) resulting from hyperglycemia and inadequate endogenous an... more Increased reactive oxygen species (ROS) resulting from hyperglycemia and inadequate endogenous antioxidant systems are responsible for the complications of diabetes. ROS accumulate in the cell and stimulate apoptosis, which compromises sperm quality and function. We investigated the possible effects of fucoidan, a potent antioxidant with a regulatory effect on blood glucose homeostasis, on the testicular tissues of rats with experimental diabetes. Diabetes was induced by administering 40 mg/kg streptozotocin (STZ) on five consecutive days. Twenty-four Wistar albino male rats were divided into four groups: group 1, control group (CG); group 2, diabetes group (DG); group 3, early fucoidan group (EFG) treated with 50 mg/kg fucoidan after diabetes induction; group 4, late fucoidan group (LFG) treated with the same dose of fucoidan 15 days after diabetes induction. Fucoidan was administered intraperitoneally every two days for four weeks. Basement membrane thickness and Johnsen scores were higher in the DG than in the CG; no difference was found for either the EFG or LFG compared to the CG. Seminiferous tubule diameters of EFG were significantly greater than for the DG. Apoptotic tubule and apoptotic cell indexes were significantly greater in the DG and significantly less in the EFG and LFG groups compared to the CG. Early use of fucoidan in diabetic individuals may minimize damage to testicular tissue.

Biologia

Estrogens are used extensively in cancer therapy of male genital organs. They may cause feminisat... more Estrogens are used extensively in cancer therapy of male genital organs. They may cause feminisation in men due to the role of their antihormonal effects. The aim of our study was to examine the e�ects of ethynyl estradiol on ultrastucture of testis germ cells. We used male Wistar rats, three and a half months old, weighing 200 g, which were divided into one control and two experimental groups. 0.0005 mg/kg dose of ethynyl estradiol was administered intraperitoneally in the �rst experiment group every other day and every day in the second experimental group for two months. Two months later, we processed the samples of testes for light and electron microscopic observations. Estrogen administered rats were compared with the control group. In the first experimental group, a decrease in the number of germ cell layers and an increase of smooth endoplasmic reticulum, hydratation in mitochondria, vacuoles in cytoplasm of Sertoli cells were observed. Thickening of tubule basal lamina, a dec...

Medical Journal of Western Black Sea, 2017

Çalışmamızın amacı, diyabetik erkek sıçanlarda c-Jun N-terminal kinaz (JNK) inhibisyonunun, apopt... more Çalışmamızın amacı, diyabetik erkek sıçanlarda c-Jun N-terminal kinaz (JNK) inhibisyonunun, apoptotik bir yolak olan Fas/FasL sinyal yolağına olası etkilerini ortaya koymaktır. Otuz adet Sprague Dawley erkek sıçandan rastgele beş grup oluşturuldu. Birinci grup: Kontrol grubu (sadece çözücü verilen grup, n=6), 2. grup: Tek doz 60 mg/kg streptozotosin (STZ) i.p., 15 gün (n=6), 3. grup: 60 mg/kg STZ, 30 gün (n=6), 4. grup: 60 mg/kg STZ + 15 mg/kg SP600125 (JNK inhibitörü) i.p., 15 gün (n=6), 5. grup: 60 mg/kg (STZ) + 15 mg/kg SP600125, 30 gün (n=6). Deney sonunda, deneklerden alınan testis doku örnekleri rutin takibe alındı ve parafine gömüldü. Fas, FasL ve kaspaz 8 proteinleri immünohistokimyal olarak değerlendirildi. Fas ve kaspaz 8 immünpozitif hücre sayısı tüm deney gruplarında kontrol grubuna göre, FasL immünpozitif hücre sayısının ise 4. grup hariç, diğer tüm gruplarda kontrol grubuna göre anlamlı şekilde arttığı saptanmıştır. Ayrıca Fas, FasL ve kaspaz 8 immünpozitif hücre sayılarının 2. gruba kıyasla 4. grupta, 3. gruba kıyasla da 5. grupta anlamlı şekilde azaldığı gözlenmiştir. Sonuçta; diyabetik testis dokusunda meydana gelen apoptoziste, Fas/FasL sinyal yolağının önemli etkilerinin olduğu ve JNK inhibitörü olan SP600125'in, JNK ile birlikte Fas/FasL sinyal yolağı üzerinden de, diyabetik testiküler apoptozisi önlemede önemli bir rol üstlenebileceği kanısındayız.

Acupuncture in Medicine

Objective: We aimed to evaluate the effects of electroacupuncture (EA) at ST36 and BL20 on the te... more Objective: We aimed to evaluate the effects of electroacupuncture (EA) at ST36 and BL20 on the testicular tissues in a rat model of diabetes and to explore the mechanisms of action. Methods: A total of 34 male Sprague-Dawley rats were allocated to a control group (n = 10), diabetes (D) group (n = 12) or diabetes + acupuncture (DA) group (n = 12). To model diabetes, rats in groups D and DA received an intraperitoneal injection of a single dose of 35 mg/kg streptozotocin (STZ) dissolved in citrate buffer (pH = 4.5; 0.1 M) after 2 weeks of high-fat diet administration. Under xylazine/ketamine anesthesia, stainless steel needles (30 mm × 0.25 mm) were inserted bilaterally at ST36 and BL20. The needles were connected to an EA device via cables, and EA was applied for 30 min (15 Hz frequency and 0.2–1 mA intensity) twice a week for 5 weeks. Results: The effects of EA at ST36 and BL20 on blood glucose levels and body weight, biochemical parameters, histopathological, morphometric and immun...

Turkish Journal of Biology

Balkan Medical Journal, Nov 29, 2004

Journal of the International Society of Antioxidants in Nutrition & Health, 2016

Objectives: Fucoidan derived from brown algae, has a hypoglycemic property, antioxidant, antitumo... more Objectives: Fucoidan derived from brown algae, has a hypoglycemic property, antioxidant, antitumoral effects.The aim of the study is to reveal of the possible effects of fucoidan on diabetic rat liver. Material and method: Twenty four Sprague-Dawley male rats, 250–350 g, were divided randomly into four group (n=6); control group, diabetic group (40 mg/kg streptozotocin, consecutive 5 days), diabetic+50 mg/kg ip fucoidan (onset of diabetes, every other day, during 6 weeks) group and diabetic+50 mg/kg ip fucoidan (after 15. day of diabetes, every other day, during 6 weeks) group. At the end of the experimental process, liver tissue samples were collected, proliferating cell nuclear antigen and inducible nitric oxide synthase (iNOS) were evaluated by using immunohistochemistry to examine the proliferation and inflammation in the diabetic liver tissues. Results: While proliferation index decreased in diabetic group compared with control group (P<0.05), both fucoidan groups proliferat...

Biotechnic & Histochemistry, 2021

We investigated how proanthocyanidin treatment altered c-Jun N-terminal kinases, transforming gro... more We investigated how proanthocyanidin treatment altered c-Jun N-terminal kinases, transforming growth factor beta 1, serine/threonine-specific protein kinase, interleukin 1 beta and insulin-like 3 expression in the testis of diabetic rats. We used 24 Wistar albino male rats divided into four groups. Group 1 was untreated control. Group 2 was treated with 40 mg/kg streptozotocin (STZ) for 5 days. Group 3 was treated with 40 mg/kg STZ + 250 mg/kg proanthocyanidin once daily for six weeks. Group 4 was treated with 40 mg/kg STZ + 250 mg/kg proanthocyanidin. Superoxide dismutase activity was reduced in groups 3 and 4 compared to group 2. Glutathione peroxidase activity was increased significantly in groups 3 and 4 compared to groups 1 and 2. Catalase activity was decreased in group 4 compared to group 2. We found that proanthocyanidin increased cell proliferation in diabetic testis. Phospho-JNK and TGF-β1 immunostaining was decreased groups 3 and 4 compared to group 2, while p-Akt immunostaining was increased in groups 3 and 4. The number of IL-1β immunostained cells in groups 3 and 4 was decreased compared to group 2. INSL-3 immunostaining was increased significantly in group 3 compared to group 2. Our findings indicate that proanthocyanidin ameliorated diabetes related testicular dysfunction. Proanthocyanidin contributes to a balanced oxidant-antioxidant status, and balanced proliferation and apoptosis activity in the germinal cells.

Advanced Pharmaceutical Bulletin, 2021

Purpose: Autism is a multifactorial neurodevelopment disease and it has not been disclosed as a h... more Purpose: Autism is a multifactorial neurodevelopment disease and it has not been disclosed as a hypoglutamatergic or hyerglutamathergic disease. Ceftriaxone is an antibiotic that increases GLT-1 expression in the brain in chronic use. In our study we aimed to investigate the effects of different doses of ceftriaxone in postnatal period in male mice exposed to valproic acid (VPA) at 12.5th day of pregnancy. Material and Methods: A total of 96 Balb/c male mice were divided into 12 groups (n=8 animals per group). Ceftriaxone (50, 100, 200 mg/kg/day) or saline was given to the male offsprings born from pregnant mice administered VPA and/or saline, between days 47 and 55. Dihydrokainic acid (10 mg/kg), a glutamate transporter-1 (GLT-1) inhibitor, was administered intraperitoneally to evaluate whether GLT-1 mediates the effect of ceftriaxone. Three chamber sociability and social interaction test and the rota rod test were performed in all groups on days 54 and 55. GLT-1 levels in the hipp...

Andrologia, 2021

Sitagliptin increases the levels of incretin hormones and stimulates a decrease in blood glucose ... more Sitagliptin increases the levels of incretin hormones and stimulates a decrease in blood glucose levels, by blocking the DPP4 enzyme. We have very limited information about impact of sitagliptin on male genital system and relationship between sitagliptin/diabetes/ER. Fucoidan can be effective in blood glucose homeostasis. We goal to explain of the effect of sitagliptin and introduce an approach of fucoidan treatment in experimental diabetes in male rats. Fifty‐eight Wistar albino rats were divided into C‐control group and D‐diabetes group: 60 mg/kg streptozotocin intraperitoneal (i.p.); DS group: STZ + 10 mg/kg sitagliptin intragastric (i.g.); DF group: STZ + 100 mg/kg fucoidan i.p.; and DSF group: STZ + 10 mg/kg sitagliptin + 100 mg/kg fucoidan. A significant decrease was detected when DS, DF and DSF groups compared to group D in blood glucose levels, basement membrane thickness and also apoptotic cell/tubule index, pJNK, caspase 3, caspase 12, GRP78, CHOP and DPP4. Sitagliptin and fucoidan have been found to be effective in blood glucose homeostasis and reducing the expression of certain proteins that lead to apoptosis and especially the proteins in the ER stress pathway. Therefore, we think that both sitagliptin and fucoidan can be effective in preventing or eliminating histopathological damages in diabetic testicular tissues, and their treatment effects can be used more.

Audiology and Neurotology, 2021

Introduction: The effect of orally consumed monosodium glutamate (MSG), which is a common additiv... more Introduction: The effect of orally consumed monosodium glutamate (MSG), which is a common additive in the food industry, on the cochlea has not been investigated. The present study aimed to investigate the possible cochleotoxic effects of oral MSG in guinea pigs using electrophysiological, biochemical, and histopathological methods. Methods: Thirty guinea pigs were equally divided into control and intervention groups (MSG 100 mg/kg/day; MSG 300 mg/kg/day). At 1 month, 5 guinea pigs from each group were sacrificed; the rest were observed for another month. Electrophysiological measurements (distortion product otoacoustic emission [DPOAE] and auditory brainstem response [ABR]), glutamate levels in the perilymph and blood samples, and histopathological examinations were evaluated at 1 and 2 months. Results: Change in signal-to-noise ratio at 2 months was significantly different in the MSG 300 group at 0.75 kHz and 2 kHz (p = 0.013 and p = 0.044, respectively). There was no statisticall...

Chinese Journal of Physiology, 2019

Both nesfatin-1 and cannabinoid systems involved in the regulation of sleep, metabolism, and food... more Both nesfatin-1 and cannabinoid systems involved in the regulation of sleep, metabolism, and food intake. The relationship between cannabinoid system and nesfatin-1 levels remains to be elucidated. This study investigated nesfatin-1 and insulin resistance in 72-h rapid eye movement (REM) sleep-deprived mice under the effects of cannabinoid, and cannabinoid receptors CB1R and CB2R blocking. Sixty mice were exposed to 72-h sleep deprivation. Groups and drug administrations were as follows: Group 1 (control) received injection of vehicle. Group 2 received WIN 55,212,2. Group 3 received AM251 (CB1R antagonist) followed by WIN 55,212,2 injection. Group 4 received SR144528 (CB2R antagonist) followed by WIN 55,212,2 injection. Group 5 received only AM251. Group 6 received only SR144528. Blood samples were collected 1 h after drug administration and prepared for biochemical measurements. Glucose levels were measured by glucometer, whereas insulin and nesfatin-1 levels were measured by ELISA. Central nesfatin-1 was also assessed using immunohistochemistry. One-way analysis of variance together with post hoc Tukey's test was used for inter-group comparisons. Serum nesfatin-1 levels were comparable in all study groups. Brain nesfatin-1 immune-positive cell count was lower in WIN group compared to controls. The administration of CB1R or CB2R antagonist prevented reduction in nesfatin-1-positive cell count. Insulin resistance was higher in WINCB2 and CB2 groups than in control and WINCB1 groups. Cannabinoid treatment reduced nesfatin-1 immunoreactivity in the central nervous system and this effect was prevented by either CB1R or CB2R antagonist pretreatment. Insulin resistance might be related to CB2 receptor activation which was independent from central nesfatin-1 immunoreactivity.

Proceedings of the 15th International Congress of Histochemistry and Cytochemistry, 2017

Acta Cirurgica Brasileira, 2014

Advances in clinical and experimental medicine : official organ Wroclaw Medical University

Endometriosis is one of the most common chronic gynecological diseases. The aim of the study was ... more Endometriosis is one of the most common chronic gynecological diseases. The aim of the study was to examine the effects of curcumin and/or deferoxamine on cell proliferation in a rat model of endometriosis. Thirty female 12-week-old albino Wistar rats, weighing 200-250 g, were used in this study. All the rats underwent ovariectomy and 0.1-mg β-estradiol 17-valerate pellets were placed intraperitoneally. An experimental model of endometriosis was created in all the animals. To create the experimental model, an approximately 1-cm long section of the uterus was taken, primarily from the right horn of the uterus. Autologous fragments were then placed between the peritoneum and muscle. The animals were divided into 3 groups: Group A, treated only with the vehicle used for curcumin and deferoxamine; group B, treated with curcumin (100 mg/kg body weight); and group C, treated with deferoxamine + curcumin (100 mg/kg body weight). After biopsy samples were obtained, the sections were stained...

Fundamental & Clinical Pharmacology, 2016

Biotechnic & Histochemistry, 2016

We investigated the role of the Fas/Fas ligand (FasL) signaling pathway in diabetic male infertil... more We investigated the role of the Fas/Fas ligand (FasL) signaling pathway in diabetic male infertility. Male rats were divided into two groups: a control group and a streptozotocin induced diabetic group. Thirty days after induction of diabetes, samples of testes were harvested and fixed in 10% formalin for light microscopy. Germ cell apoptosis was determined using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate in situ nick end-labeling (TUNEL) and immunostaining of caspase 8 and active caspase 3. We also investigated the expressions of Fas and FasL using immunohistochemistry. Streptozotocin-induced diabetes caused severe histopathological damage and increased apoptotic tubule and apoptotic cell indices, caspase 8 and caspase 3 expressions, and Fas and FasL-immunopositive cells in the rat testes. We suggest that the Fas/FasL signaling pathway may play a role in male infertility caused by diabetes.