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
Alzheimer hastalığında ilerlemenin manyetik rezonans görüntülerindeki subkortikal hacimlerle makine öğrenmesi kullanılarak kestirilmesi
(Başkent Üniversitesi, 2025) Soylu, Can; Harı, Emre; Demiralp, Tamer
Amaç: Alzheimer hastalığının (AH) erken dönemlerinde başlayan subkortikal yapılardaki ilerleyici dejenerasyonu bilinmektedir. Bu çerçevede, AH’de ilerlemenin ön görülmesi oldukça kritik bir yere sahiptir. Bu çalışmada, makine öğrenmesi (MÖ) kullanılarak subkortikal hacimlerin hastalığın ilerleyici seyrini öngörme potansiyellerinin araştırılması amaçlanmıştır. Gereç ve Yöntem: Çalışmaya Alzheimer Hastalığı Nörogörüntüleme Girişimi (ADNI) veri tabanından elde edilen, klinik tanısı ilerleyici (progresif, n=186) ve ilerleyici olmayan (non-progresif, n=235) olarak iki sınıfa ayrılmış toplam 421 katılımcının T1 ağırlıklı anatomik manyetik rezonans görüntüleme (MRG) verileri dahil edilmiştir. Anatomik MRG verisi FreeSurfer 7.2 programıyla işlenerek standart segmentasyon aşamalarında yer alan tüm subkortikal yapılara ait toplam hacimsel değerler elde edilmiştir. Ayrıca, hippokampal alt alanlar, talamus ve amigdala alt çekirdeklerinin hacimsel değerleri de hesaplanmıştır. Hacimsel değerler, MÖ algoritmalarında kullanılmadan önce intrakraniyal hacimlerle normalize edilmiştir. Normalize edilen tüm hacim değerleri kümesine PyCaret 3.0 kütüphanesi kullanılarak öznitelik seçimi uygulanmış ve subkortikal yapıların önem sıralaması Shapley (SHAP) değerleri ile belirlenmiştir. Bulgular: Subkortikal yapıların toplam hacimlerini içeren veri kümesi kullanılarak gerçekleştirilen MÖ sonucunda, bilateral amigdala, sol hippokampus, sol nucleus accumbens ve sağ lateral ventrikül ön plana çıkarak, progresif ve non-progresif grupları birbirinden %79 oranında doğruluk ile ayırt edebilmiştir. Diğer yandan, subkortikal yapıların küçük ölçekli alt alanlarının ve çekirdeklerinin hacim değerleri kullanıldığında ise bilateral amigdala-aksesuar bazal çekirdekler, sol amigdala-lateral çekirdek, amigdala-santral çekirdek, kortiko-amigdaloid geçiş alanı ve sol hippokampus-presubikulum ön plana çıkmış ve grupları birbirinden %81 oranında doğruluk ile ayırabilmiştir. Sonuç: Otomatik MÖ algoritmaları, AH’nin ilerleyici seyrini öngörebilmek için kritik rol oynayan subkortikal yapıları tutarlı bir şekilde belirleme potansiyeline sahiptir. Ayrıca, farklı ölçekteki segmentasyon kombinasyonlarına rağmen, amigdala ve hippokampus içindeki spesifik alt yapıların tutarlı şekilde ön plana çıkması AH patolojisinin takibinde bu nöroanatomik bölgelerin kritik rolünü vurgulamaktadır. Bulgularımız, AH'nin erken tanı ve takibi için otomatik MÖ algoritmalarının klinik destek aracı olarak potansiyelini vurgulamaktadır.
Interfacial bond strength of CAD/CAM resin composites on dentin vs. composite substrates: Influence of dual-cure and self-adhesive resin cements
(MDPI Publishing, 2026) Batgerel, Oyun Erdene; Yazıcıoğlu, Oktay; Kıtın, Emine; Gençel, Burç İhsan; Yamak, Fatih; Ergün Bozdağ, Süreyya; Sasany, Rafat
This in vitro study evaluated the shear bond strength (SBS) of four CAD/CAM (Computer aided design/Computer aided manufacturing) polymer-based indirect composites bonded to dentin and microhybrid composite substrates using two resin cements. Gradia Plus (GP), Ceramage (Ce), Tescera ATL (TA), and Lava Ultimate (LA) were fabricated into cylindrical specimens (3 × 3 mm). Dentin substrates were obtained from extracted molars, while composite substrates were prepared from Filtek Z250 (4 mm × 2 mm). Bonding was performed using either a self-adhesive resin cement (RelyX U200; RU200) or a dual-cure adhesive resin cement (RelyX Ultimate; RU), resulting in 16 experimental groups (n = 12 per group). SBS was measured using a universal testing machine (1 mm/min), and failure modes were assessed under stereomicroscopy. Bond strength was significantly higher on composite substrates than on dentin (p < 0.001), primarily due to favorable polymer– polymer compatibility and matrix interdiffusion, which improved stress accommodation at the adhesive interface. TA and Ce showed superior adhesion when combined with RU, while LA exhibited the lowest values, particularly on dentin bonded with RU200. Overall, the dual-cure adhesive system provided stronger bonding than the self-adhesive system (p < 0.05). These findings highlight the influence of substrate type, composite architecture, and cement chemistry on interfacial performance in indirect polymer-based restorations.
Long-Term endocrine outcomes with special emphasis on the gonadal impact of acute lymphoblastic leukemia treatment in females
(Springer Nature Link, 2026) Karakaş, Hasan; Tarçın, Gürkan; Bayramoğlu, Elvan; Turan, Hande; Ocak, Süheyla; Turan, Volkan; Evliyaoğlu, Olcay; Tiraje, Tiraje; Apak, Hilmi; Ercan, Oya
This study aims to explore the long-term endocrine and gonadal effects of chemotherapy and radiotherapy in female acute lymphoblastic leukemia (ALL) patients. A cohort study included girls diagnosed with ALL and treated between 2000 and 2020. Patients with at least 2 years elapsed since treatment completion were included. Endocrinological evalua tions included anthropometric measures and pubertal status, as well as fasting insulin, glucose, lipid levels, and hormone assessments for adrenal, and thyroid functions. Reproductive functions were evaluated based on gonadotropin, estradiol, and anti-Müllerian hormone (AMH) levels. A total of 51 female patients were included. At the time of study participa tion, the mean age was 14.7 years, and the mean time since treatment completion was 9.4 years. At least one endocrine disorder was present in 39.2% of participants, with dyslipidemia, insulin resistance, and obesity being the most common. Low AMH levels (<1.1 ng/dL) were found in 41.6%, particularly in those who underwent bone marrow transplantation. A significant positive correlation was found between the time elapsed since treatment and AMH levels (p<0.001, r=0.612), while age at diagnosis, risk group (standard, intermediate or high risk), and cranial radiotherapy showed no significant associations. A substantial proportion of ALL survivors developed endocrine complications, with ovarian reserve compro mised in over 40% of cases. Notably, this is the first cohort study to demonstrate a significant positive correlation between AMH levels and the time elapsed since treatment, suggesting a potential for gonadal recovery except in those exposed to intensive chemotherapy or transplantation.
Evaluation of seropositivity developed against specific antigens of helicobacter pylori in neurodegenerative diseases
(Turkish Neuropsychiatric Society, 2026) Akçin, Rüveyda; Tütüncü, Melih; Karagöz Sakallı, Nazan; Apaydın, Hülya; Bozluolçay, Melda; Can, Günay; Soysal, Aysun; Sirekbasan, Serhat; Dinç, Harika Öykü; Sarıbaş, Suat; Kocazeybek, Bekir
Introduction: It is suggested that Helicobacter pylori (Hp) can reach the brain via the oral-nasal-olfactory route, through Hp-infected monocytes in the disrupted blood-brain barrier (BBB), or through a rapid retrograde neural network leading to neurodegeneration from the gastrointestinal tract (GIS) and may lead to neurodegenerative diseases such as Alzheimer’s (AD), Parkinson’s (PD) and Multiple sclerosis (MS). In this study, we aimed to evaluate the possible immunopathogenesis relationship between Hp-specific antigens and neurodegenerative diseases by determining the frequency of seropositivity against different specific antigens of Hp in diseases such as AD, PD and MS. Methods: In our cross-sectional, retrospective case-control study, the immunoreactivity frequencies of Hp-specific and non-specific CagA (p120), VacA (p95), p75, FSH (p67), UreB (p66), HSP homolog (p57), flagellin (p54), p50, p41, p33, OMP (p30), UreA (p29), p26, OMP (p19), p17 antigens were determined by Western Blot method in 36 AD, 35 PD, 91 MS cases with Hp-IgG reactivity, and 55 controls without a neurodegenerative/demyelinating by ELISA method. Results: No significant difference was found between the immunoreactivity frequencies of Hp antigens between AD and control groups (p>0.05). In the multivariate logistic analysis performed for PD cases, age ≥ 50 and immunoreactivity frequency of p19 were found to be independent risk factors (OR: 36.752, p<0.05) (OR: 5.570, p<0.05). In MS cases, immunoreactivity frequency of p17 antigen was found to be a risk factor (OR: 2.646, p<0.05). In addition, the mean level of Hp-IgG reactivity was found to be negatively associated with MS development (indicating an inverse correlation) in the control group compared to the MS group (OR: 0.585, p < 0.05). Furthermore, logistic regression analysis in the total study group revealed that the immunoreactivity frequency of the p17 antigen was identified as a risk factor for MS (OR: 2.438, p<0.05). Conclusion: Our data on AD cases are insufficient. In PD cases, the significantly higher frequency of immunoreactivity to the Hp-p19 antigen in individuals aged ≥50 years (OR=5.570) is noteworthy. In the MS group, the significantly high detection of Hp p17 antigen and its presence as a risk factor (OR=2.646), and the significantly high detection of p26 antigen suggest the relationship between these antigens and the MS development process. However, it is a fact that new and many prospective cohort-based case-control studies are needed to reveal this more clearly.
Hemimyelomeningocele: A systematic review and meta‑analysis of the literature
(Springer Nature Link, 2026) Adıyaman, Ali Ekrem; Karakaş, Furkan; Hamzaoğlu, Can; Saban, Şevval; Kılınç, Tunahan; Acar, Burak; Nabili, Tabriz; Ekşi, Murat Şakir
Hemimyelomeningocele (HMM) is a rare split cord malformation where only one hemicord forms a myelomeningocele-like sac, and the opposite hemicord undergoes normal neurulation. We aimed to compile all published HMM cases to concisely summarize embryology, presentation, imaging, associated anomalies, management, and outcomes of the disorder. Following PRISMA 2020, we searched PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar (1968–Feb 2025) for studies with confirmed human HMM, extracting clinical, radiological, surgical, and follow-up data. Of 688 records screened, 25 articles met inclusion criteria, encompassing 67 patients. Most publications were single-patient case reports. Presentation occurred predominantly in newborns or early infancy. The dysraphic sac was lumbosacral in most cases, and type I split cord malformation with a bony spur outnumbered type II. Hemivertebrae and congenital scoliosis were the common vertebrae anomalies. Nearly all patients underwent surgery combining sac excision, detethering, and bony spur removal. Postopera tive neurological outcomes were favorable: the majority improved, and the other ones remained stable; no surgery-related mortality was reported. HMM can be recognized as a distinct clinic radiological entity within the split-cord spectrum. Early, ideally prenatal diagnosis, timely microsurgical repair, and coordinated multidisciplinary care yield favorable functional outcomes in most patients. This first systematic review compiles the available evidence and provides a practical basis for future diagnostic and treatment decisions.
