İstanbul Sağlık ve Teknoloji Üniversitesi Kurumsal Akademik Arşivi
DSpace@İSTÜN, Üniversite mensupları tarafından doğrudan ve dolaylı olarak yayınlanan; kitap, makale, tez, bildiri, rapor, araştırma verisi gibi tüm akademik kaynakları uluslararası standartlarda dijital ortamda depolar, Üniversitenin akademik performansını izlemeye aracılık eder, kaynakları uzun süreli saklar ve telif haklarına uygun olarak Açık Erişime sunar.
Güncel Gönderiler
Spermatogenez
(BİDGE Yayınları, 2025) İnce, Zeynep Yelda; Ündağ, İlknur; Ündağ, İlknur; Dönmez, Hasan Hüseyin
Spermatogenez, testisteki seminifer tübüller içinde yer alan germ hücrelerinin, spermatogonyal kök hücre düzeyinden olgun spermatozoona kadar ilerleyen, mitotik, mayotik ve postmayotik farklılaşma basamaklarını içeren son derece organize bir süreçtir (Jan ve ark., 2017; Griswold, 2018). Bu süreç boyunca spermatogonyumlar, kendini yenileme ve farklılaşma arasında karmaşık bir denge kurarak gelişimsel kaderlerini belirlerken, primer ve sekonder spermatositler ardışık mayoz bölünmeler aracılığıyla kromozom yükünü haploid düzeye indirger. Bunu takiben, spermatidler spermiogenez olarak tanımlanan terminal maturasyon evresinde yoğun bir morfolojik ve yapısal yeniden düzenlenme geçirerek fonksiyonel spermatozoona dönüşür (Rowley ve ark., 1971; Zickler & Kleckner, 2015). Spermatogenez, yalnızca germ hücre döngüsünün içsel kinetiklerine indirgenemeyecek kadar kompleks bir biyolojik süreç olup, Sertoli hücreleri, Leydig hücreleri, peritübüler miyoid hücreler ve interstisyel mikroçevrenin bütünleşik yapısal ve parakrin katkıları ile şekillenir (Griswold, 2018; Thumfart & Mansuy, 2023). Seminifer epitelde her bir gelişim basamağının belirli bir mekânsal ve zamansal dizilim içerisinde ortaya çıkması, germ hücre maturasyonunun yüksek derecede organize bir epitel siklusuna tabi olduğunu ve bu siklusun seminifer tübüller boyunca koordineli olarak ilerleyen, ardışık gelişimsel kümeler şeklinde düzenlendiğini ortaya koymaktadır (Jan ve ark., 2017). Güncel araştırmalar, spermatogenezin sürdürülebilir başarısının; germ hücrelerine özgü transkriptomik programların dinamik düzenlenmesi, spermatogonyal kök hücre nişinin yapısal ve işlevsel bütünlüğü, Sertoli hücrelerinden salınan büyüme faktörleri ile eksozomal yüklerin koordinasyonu ve bunları şekillendiren hassas endokrin ve parakrin sinyal ağlarının etkileşimine bağımlı olduğunu göstermektedir (Fayomi & Orwig, 2018; Tian ve ark., 2024).
Novel 1-benzyl-2-indolinone indole hybrids as tyrosine kinase inhibitors: Design, synthesis, and biological activity evaluation
(Elsevier, 2026) Cihan Üstündağ, Gökçe; Cinek, Tuğçe; Sancar, Serap; Yıldırım, Merve; Genç Akar, Öyküm; Özen Eroğlu, Güneş; Erol Bozkurt, Ayşe; Öztay, Füsun; Soylu Eter, Özge; Bolkent, Şehnaz; Kuruca, Serap; Karalı, Nilgün
In the present study, new 1-benzyl-2-indolinone indole hybrids (4a-s) were synthesized and their cytotoxic ef fects were determined against human breast (MCF-7 and MDA-MB 231), lung (A549), kidney (CAKI-1 and A498), colon (HT-29 and HCT-116), and pancreas (MIA PaCa-2) cancer cells by MTT assay. Some of the tested com pounds showed significantly better inhibitory effects and safety profiles than sunitinib malate against A498 and MIA PaCa-2 cells. Compound 4s showed a selective and significant cytotoxic effect on MIA PaCa-2 cells (IC50 = 0.15 μM; SI > 666.7). Compound 4b displayed significant cytotoxic effects on both A498 (IC50 = 0.87 μM; SI > 58.3) and MIA PaCa-2 (IC50 = 0.13 μM; SI = 390.0) cells. Compound 4b in A498 cells and compounds 4a-c, 4h, and 4s in MIA PaCa-2 cells significantly decreased general tyrosine kinase activity and induced apoptosis, accompanied by reduced ERK signalings. The inhibitory activities of compounds 4a–c, 4h, and 4s against SRC, PDGFR-β, and c-MET kinases were assessed in MIA PaCa-2 cells. Compounds 4a, 4b, 4h, and 4s inhibited PDGFR β, with 4h and 4s additionally targeting c-MET, while 4a, 4b, and 4h also demonstrated SRC inhibition. In this study, lead compounds 4b and 4s were identified as selective cytotoxic agents against human pancreatic car cinoma cells through induction of apoptosis and inhibition of SRC/PDGFR-β/c-MET signaling. Notably, com pounds 4b and 4s demonstrated a significantly better safety profile than sunitinib malate against noncancerous cells, underscoring their broader therapeutic potential. To understand their potential binding modes, molecular modeling studies were performed at the ATP-binding domains of SRC, PDGFR, and c-MET kinases.
Nio nanoflower based sorbent extraction for a novel HPLC–UV method for the determination of solifenacin in human plasma and its application to a prototype pharmacokinetic study
(Springer Nature Link, 2025) Ceylan, Burhan; Önal, Cem; Kurnaz Yetim, Nurdan; Hasanoğlu Özkan, Elvan; Önal, Armağan
Solifenacin is an active pharmaceutical product used in overactive therapy. The main goal of this work was to develop a high-performance liquid chromatographic (HPLC) method with ultraviolet detection for measuring the amount of quanti fied solifenacin in human plasma samples that is rapid, straightforward, and accurate. Prior to chromatographic analysis, a nanomaterial-based sorbent extraction technique utilizing NiO nanoflowers was employed for plasma sample preparation. In this method, NiO nanoflowers were employed, and the adsorption process underwent optimization. Chromatographic separation was carried out using a reversed-phase C18 analytical column (5 µm×4.6 mm×150 mm) with a mobile phase composed of water (0.2% triethylamine) and acetonitrile (30:70 v/v), and the pH was adjusted to 3.5 with ortho-phosphoric acid. The flow rate was set at 1.0 mL/min, and the investigation was performed using UV at 220 nm. The retention time of solifenacin is 3.10±0.01 min. The linear behaviour of the proposed approach was examined in the 0.01–30 ng/mL range (r 2=0.9995). The proposed method is in alignment with the criteria established by the European Medical Agency (EMA) about the accuracy, precision, repeatability, specificity, robustness and detection and quantification. Limit of detection and limit of quantification are determined to be 0.003 and 0.01 ng/mL, whereas relative standard deviation was determined to be less than 2.75% for intra-run and inter-run measurements. The plasma concentration–time profile and pharmacokinetic parameters such as AUC0–t , AUC0–∞, Cmax, tmax, and t1/2, were calculated according to the assays. The proposed method is feasible to investigate the bioequivalence, bioavailability, and routine analysis of the drug in plasma.
Enhancing home-based exercise therapy with telerehabilitation in mild adolescent idiopathic scoliosis: A randomized controlled trial
(MDPI Publishing, 2025) Takinacı, Zuhal Didem; Çelik, Meltem; Yıldız, Şeyda; Talmaç, Mehmet Ali; Dut, Raziye
Background and Objectives: Adolescent idiopathic scoliosis (AIS) is a three-dimensional spinal deformity that affects postural alignment, function, and quality of life. Telere habilitation has emerged as a promising approach to enhance accessibility and conti nuity of exercise-based treatment in AIS. This study aimed to compare the effects of telerehabilitation-supported home exercise programs with standard home exercises on posture, pain, body image, and quality of life in adolescents with mild AIS. Materials and Methods: Forty adolescents aged 10–18 years with mild AIS (Cobb angle 10–25◦ , Risser 0–3) were randomly assigned to two groups: study (n = 20) and control (n = 20). Both groups performed an 8-week home-based exercise program. The study group addition ally received weekly online supervision by a physiotherapist. Outcomes included pain severity (VAS), posture (New York Posture Assessment Scale), body image (Walter Reed Visual Assessment Scale), and quality of life (SRS-22 questionnaire). Statistical analyses were performed using non-parametric tests, with a significance level of p < 0.05. Results: Twenty-nine participants completed the study (15 in the study group, 14 in the control group). Significant improvements were observed in the study group in SRS-22 total, pain, and function subscores, as well as posture scores (p < 0.05). In the control group, only the satisfaction subscore improved significantly (p < 0.05). No significant changes were detected in body image (WRVAS) in either group. Between-group comparisons showed greater overall clinical gains in the study group despite similar exercise adherence rates. Conclusions: Supervised telerehabilitation enhances the effectiveness of home-based exer cise programs in adolescents with mild AIS by improving postural alignment, reducing pain, and increasing functional capacity and quality of life. Telerehabilitation represents an accessible and efficient complementary strategy for managing AIS when in-person supervision is limited.
Green light and intermittent lighting modulate testicular gonadotropin inhibitory hormone without central or morphological effects in broiler chickens
(Islamic Azad University, 2025) Aykoç Göçer, Miray; Akın, S. G.; Özel Armutoğlu, Emine; Koç Yıldırım, Ece
Environmental factors, especially light duration and wavelength (colour), affect reproductive physiology in broilers. In birds, light is perceived especially by extraretinal photoreceptors in the brain, including the hy pothalamus, which regulates reproductive function. Gonadotropin-inhibitory hormone (GnIH), expressed in both the hypothalamus and gonads, suppresses gonadotropin release and modulates reproductive activity. Its expression is influenced by photoperiod and light colour. Rooster fertility is economically important, as one male can inseminate many females. This study investigated how green light and intermittent lighting affect GnIH levels and testicular development in prepubertal broiler males. 288 one-day-old male commer cial broilers (Ross-308) were divided into four groups (n=12) and exposed to: Group I, 18 hours light - 6 hours dark (18L:6D) with white light; Group II, 18L:6D with green light; Group III, 17L:3D:1L:3D with white light; and Group IV, 17L:3D:1L:3D with green light. The study was conducted in four identical ex perimental rooms, each consisting of six pens (replicates). Two male broilers were randomly selected from each pen. A total of 48 chickens, 2 males from each pen (replicate group), were randomly selected for analysis. After 42 days under standard conditions, GnIH levels were measured in the hypothalamus and testes via ELISA. Testicular development was assessed histologically by evaluating seminiferous tubule diameter and epithelial height. Results showed that intermittent lighting and green light significantly in creased testicular GnIH levels but had no effect on hypothalamic GnIH. The most pronounced increase in testicular GnIH was observed in Group IV, which received both intermittent lighting and green light. No significant differences were observed in testicular morphology. These findings suggest that intermittent lighting and green light may selectively influence gonadal GnIH levels without affecting central GnIH or morphology, offering insight into how lighting strategies may be optimized in poultry production.
