Effects of topically applied contractubex® on epidural fibrosis and axonal regeneration in injured rat sciatic nerve

AIM: To investigate the effects of Contractubex (R) (Cx) on peripheral nerve regeneration and scar formation. MATERIAL and METHODS: A surgical procedure involving sciatic nerve incision in 24 adult male Sprague-Dawley rats followed by epineural suturing was performed. In weeks 4 and 12 following surgery, macroscopic, histological, functional, and electromyographic examinations of the sciatic nerve were conducted. RESULTS: No significant difference was found between the Cx group and the control group in terms of sciatic function index (SFI) and distal latency results at week 4 (p>0.05). However, significant improvements in the Cx group were observed in SFI amplitudes and nerve action potentials at week 12 (p<0.001 and p<0.001, respectively). Significant improvements were found in the amplitudes of nerve action potentials in the treatment group after weeks 4 and 12 (p<0.05 and p<0.001, respectively). Macroscopically and histopathologically, epidural fibrosis decreased (p<0.05 and p<0.001, respectively). For both measurement times, the treatment group had significantly higher numbers of axons (week 4, p<0.05; week 12, p<0.001), and the treatment group had better results regarding its axon area (weeks 4 and 12, p<0.001) and myelin thickness (weeks 4 and 12, p<0.05). CONCLUSION: Cx, which is applied topically in peripheral nerve injury, affects axonal regeneration and axonal maturation positively and reduces the functional loss

Cerrahın anlık yönlendirilebildiği robot yardımlı endoskop kontrol sistemi mimarisi - NeuRoboScope

4. Türkiye Robotbilim Konferansı (ToRK 2018), 12-14 Nisan 2018, Boğaziçi ÜniversitesiBu bildiride ele alınan çalışmada endoskopik hipofiz cerrahisinde kullanılan optik-kamera sistemini, cerrahın anlık isteklerini takip ederek yönlendirilmesine izin verecek robotik sistem geliştirilmektedir. Cerrah kendisi ameliyat sahasında ameliyatı gerçekleştirirken robotu yönlendirmesi gerekmektedir. Bu gereksinim için geliştirilmekte olan özgün alt bileşenler ve toplam sistem mimarisi bildiri içinde tanıtılmıştır ve çalışmanın sonuçları benzer minimal invaziv ameliyatların robot destekli ameliyata dönüşmesine imkan verebilecektir. Bildiride sistemin gereksinimlerinin oluşturulması için yapılan testler anlatılmıştır. Üzerinde durulan sistem gereksinimlerinden birisi robotun çalışma alanı, diğeri ise cerrahın kullanım kolaylığı ile ilgilidir.TUBITAK (Proje Numaraları: 115E725 ve 115E726

Fizyolojik Uyarılarla Kortikal Yayılan Depresyonun Oluşturulması

Migraine is a primary headache disorder with an annual prevalence of 12-15% in the general population, causing considerable disability and productivity loss. Migraine aura is associated with cortical spreading depression (CSD) waves occurring in the brain. Recent studies showed that CSD itself triggers headache, which follows aura within 60 minutes. Hence, CSD has been widely used to model migraine in experimental research. However, the methods to induce CSD in animals involve direct mechanical, electrical or chemical stimuli to the brain, which do not constitute a proper representation of the actual attack initiation in migraineurs. On the other hand, it is well known that a migraine attack can be triggered by a variety of factors such as stress, intense light exposure, exercise, fasting, certain foods, sleep disturbances and hormonal imbalance. Therefore, in this study, we hypothesized that CSD can be induced by intense sensory stimulation in the susceptible mouse brain. We applied ouabain, a Na+-K+ ATPase blocker, topically to the relevant sensory cortex (visual or somatosensory) to make mouse brain susceptible to CSD (migraine), and used intense photic or whisker stimulation to trigger CSD. Increasing doses of ouabain were found to be associated with higher frequencies of spontaneous CSDs, and the threshold concentration to induce CSD was determined as 0.1 mM. Photic or whisker stimulation started at least 30 minutes after the last spontaneous CSD following the ouabain application were found to increase the CSD incidence significantly. Furthermore, we visualized extracellular potassium increases with a florescent potassium indicator, APG-4, during the CSD and sensory stimulation. Taken together, these findings show that CSD (aura) can be triggered in the susceptible mouse brain (like in migraineurs) with intense sensory stimulation, and this induction is possibly caused by extracellular potassium rise. This thesis study therefore lends support to the role of CSD in migraine pathophysiology, and also opens new avenues for the development of more realistic and physiologic experimental migraine models. Better understanding of CSD initiation and propagation mechanisms will eventually lead to more efficient preventive and therapeutic interventions in migraine.Migren, tüm dünyada %12-15 gibi yüksek yaygınlığa sahip, önemli işlev ve işgücü kayıplarına neden olan bir primer baş ağrısı türüdür. Migren aurasının beyinde oluşan kortikal yayılan depresyon (KYD) dalgaları ile ilişkili olduğu bilinmektedir. Yakın zamanda yapılan çalışmalar aurayı takip eden baş ağrısının da KYD tarafından tetiklenebildiğini göstermiştir. Bu nedenle KYD, deneysel çalışmalarda migreni modellemek amacıyla kullanılmaktadır. Fakat deney hayvanlarında KYD oluşturmak için kullanılan mekanik, elektriksel ve kimyasal yöntemler beyine doğrudan müdahale içermekte olup, bu yönüyle migrenlilerdeki atak oluşumunu tam olarak temsil edememektedir. Öte yandan migren atağının stres, kuvvetli ışık uyarısı, egzersiz, açlık, çeşitli gıdalar, uyku bozuklukları vb. birtakım etmenlerle tetiklenebildiği iyi bilinmektedir. Bu verilerden hareketle, bu tez çalışmasında KYD’nin migrene yatkın hale getirilmiş fare beyninde kuvvetli duyusal uyarılarla oluşturulabileceği hipotezinin test edilmesi amaçlanmıştır. Çalışmada, fare beynini KYD oluşumuna (migrene) yatkın hale getirmek amacıyla ilgili duyusal korteks üzerine topikal uvabain (Na+-K+ ATPaz inhibitörü) uygulaması yapılmış, tetikleyici olarak ise kuvvetli ışık veya bıyık uyarısı kullanılmıştır. Korteks üzerine uygulanan farklı uvabain konsantrasyonları ile yapılan deneylerde, uvabain dozu arttıkça KYD sıklığının arttığı bulunmuş, KYD oluşumu için eşik konsantrasyon 0.1 mM olarak belirlenmiştir. 0.1 mM topikal uvabain uygulamasını takiben son spontan KYD oluşumundan 30 dakika geçtikten sonra başlatılan ışık veya bıyık uyarıları ile KYD oluşma olasılığının anlamlı ölçüde arttığı bulunmuştur. Ayrıca bir floresan potasyum belirteci olan APG-4 ile yapılan floresan mikroskopi çalışmalarında, KYD ve duyusal uyarım sırasındaki hücre dışı potasyum artışları kaydedilmiştir. Bu bulgular, KYD oluşumuna duyarlı hale getirilen kortekste (migrenlilerde olduğu gibi), kuvvetli duyusal uyarılarla KYD’nin (auranın) tetiklenebildiğini ve bu tetiklenmeye olasılıkla hücre dışı potasyum konsantrasyonundaki artışın neden olduğunu göstermektedir. Bu yönüyle, bu tez çalışması bir yandan KYD’nin migren patofizyolojisindeki yerine destek sağlarken, bir yandan da insandaki aurayı modelleyen ve fizyolojik bir deneysel migren modelinin geliştirilmesinin de önünü açmaktadır. Gelecekte KYD oluşum ve yayılım mekanizmalarının daha iyi anlaşılmasıyla, migrene yönelik daha etkin koruyucu önlemlerin ve tedavi stratejilerinin geliştirilmesi mümkün olacaktır

Unilateral teleoperation design for a robotic endoscopic pituitary surgery system

5th International Workshop on Medical and Service Robots, MeSRob 2016; Graz; Austria; 4 July 2016 through 6 July 2016The aim of this study is to develop a teleoperation system which will be used to support the endoscopic pituitary surgery procedures. The proposed system aims to enable the surgeon to operate with three different operation tools (one of them is the endoscope) simultaneously. By this way, it is expected that the productivity of the surgical operation will be improved and the duration of the operation will be shortened. In the proposed system, a main control unit that can be attached to any of the surgical tools that are used in the operation (other than the endoscope) will be developed to capture the motion of the surgeon’s hand motion as demanded by the surgeon, to process the captured motion and to send it to the robot that handles the endoscope. In this way, the endoscope will be directed simultaneously by the surgeon throughout the operation while he/she is using the other surgical tools with his/her two hands. In this paper, the study to determine the type and processing of information that is sent from the surgeon’s side to the endoscope robot is presented.Scientific and Technological Research Council of Turkey (115E725 / 115E726

Viscoelastic modeling of human nasal tissues with a mobile measurement device

Modeling the dynamic of tool-tissue interaction for the robotic minimally invasive surgeries is one of the main issues for designing appropriate robot controllers. A mobile measurement device is produced in order to model some nasal tissues of a human. This mobile device is a hand-held one which measures the applied moments and relative angular displacements about a fixed pivot point. The ex-vivo measurements are realized by surgeons on a relatively fresh human cadaver head. The tip of the nose and the nasal concha are the two tissues that are investigated. In this study, five different viscoelastic models are considered; Elastic, Kelvin- Voight, Kelvin-Boltzmann, Maxwell and Hunt-Crossley. The results are evaluated and cross-validated on each data set. Hunt-Crossley and Kelvin-Boltzmann models provided the minimum root-mean-square (RMS) error among the other models.The Scientific and Technological Research Council of Turke

Revisiting ligament-sparing lumbar microdiscectomy: When to preserve ligamentum flavum and how to evaluate radiological results for epidural fibrosis

WOS: 000432959600042PubMed ID: 29530695OBJECTIVE: Preserving the ligamentum flavum (LF) during lumbar spine surgery can help to limit the extent of postoperative epidural fibrosis (EF), which is a potential cause of persistent leg pain. We present a retrospective analysis of microdiscectomy with preservation of the LF to evaluate the effects of the two LF mobilizing techniques (reflecting inferiorly or medially vs. removing completely) on EF and clinical outcomes. METHODS: Microdiscectomy was performed through a unilateral laminotomy in 93 patients (52 male, 41 female; mean age, 46 years; range, 25-65 years) with L3-L4 (n = 3), L4-L5 (n = 40), and L5-S1 (n = 50) lumbar disc herniation. Patients whose LF was removed were assigned to group 1 (n = 42), and patients whose LF was preserved by mobilizing it medially (n = 31) or inferiorly (n = 20) were assigned to groups 2 and 3, respectively. Follow-up visual analog scale (VAS) scores and magnetic resonance images were evaluated. RESULTS: EF scores, particularly for the anterior quadrants, were significantly higher in group 1 than in groups 2 (P = 0.012) and 3 (P = 0.001). Likewise, postoperative VAS scores in group 1 were also significantly higher than in groups 2 (P = 0.009) and 3 (P = 0.044). CONCLUSIONS: Our results demonstrate that 1) preserving the LF during lumbar microdiscectomy reduces the formation of postoperative EF and improves clinical outcomes; 2) EF in the anterior, rather than the posterior epidural space, is correlated with clinical results; and 3) the ligament mobilizing technique used should be individually tailored on the basis of the features of disc herniation

Does gross total resection improve progression-free and overall survival in pediatric intracranial ependymomas? Single-center clinical experience of 61 cases

OBJECTIVE: To share our clinical experience of 25 years and identify prognostic factors for progression-free and overall survival in pediatric intracranial ependymomas. METHODS: In total, 61 children who were treated be-tween 1995 and 2020 in a single institution were included in the study. Medical records of the patients were retro-spectively reviewed to obtain and analyze the following data: patient age at first surgery, sex, presenting symptoms, hydrocephalus and any invasive treatment, anatomic site, extent of resection, pathologic grade, time to progression, and time to death. Progression-free and overall survival rates and affecting factors were analyzed by Kaplan-Meier method. RESULTS: Dysphagia, number of surgeries, and spinal seeding were associated with progression free and overall survival in univariate analysis. The extent of resection, World Health Organization grade, and visual problems were also associated with progression whereas sex was associated with overall survival. Cox regression identified the extent of resection and single surgery as an indepen-dent prognostic factor for progression-free survival. No independent factor was found for overall survival. CONCLUSIONS: This single center experience of 25 years confirms the beneficial effect of gross total resection on disease progression. Although spinal seeding seems to affect survival rates, greater number of cases are needed to reveal its full effect

Effect of mesenchymal stem cells therapy in experimental kaolin induced syringomyelia model

Background: Syringomyelia is a pathological cavitation of the spinal cord. In this study, we examined whether a syrinx cavity would limit itself with axonal regeneration and stem cell activity in the cavity, and we evaluated subjects on a functional basis.Methods: Groups were designated as kaolin, trauma, kaolin-trauma, and saline groups. Also divided out of the syringomyelia treated groups were those given human mesenchymal stem cells (hMSCs). All groups were evaluated with immunohistochemistry, electron microscopy, confocal microscopy and functionally.Results: The kaolin-trauma group had a significant correction of BBB score with hMSCs therapy. The syrinx cavity measurements showed significant improvement in groups treated with hMSCs. The tissue surrounding the syrinx cavity, however, appeared to be better organized in groups treated with hMSCs. The process of repair and regeneration of damaged axons in the lesion were more improved in groups treated with hMSCs. Using confocal microscopy, fluorescence of hMSCs was observed in the central canal, in the ependymal tissue, and around the lesion.Conclusions: It was concluded that axonal repair accelerated in groups receiving stem cells, and thus, stem cells may be effective in recovery of neural tissue and myelin damage in syringomyelia

Cerrahın anlık yönlendirilebildiği robot yardımlı endoskop kontrol sistemi mimarisi - NeuRoboScope

4. Türkiye Robotbilim Konferansı (ToRK 2018), 12-14 Nisan 2018, Boğaziçi ÜniversitesiBu bildiride ele alınan çalışmada endoskopik hipofiz cerrahisinde kullanılan optik-kamera sistemini, cerrahın anlık isteklerini takip ederek yönlendirilmesine izin verecek robotik sistem geliştirilmektedir. Cerrah kendisi ameliyat sahasında ameliyatı gerçekleştirirken robotu yönlendirmesi gerekmektedir. Bu gereksinim için geliştirilmekte olan özgün alt bileşenler ve toplam sistem mimarisi bildiri içinde tanıtılmıştır ve çalışmanın sonuçları benzer minimal invaziv ameliyatların robot destekli ameliyata dönüşmesine imkan verebilecektir. Bildiride sistemin gereksinimlerinin oluşturulması için yapılan testler anlatılmıştır. Üzerinde durulan sistem gereksinimlerinden birisi robotun çalışma alanı, diğeri ise cerrahın kullanım kolaylığı ile ilgilidir.TUBITAK (Proje Numaraları: 115E725 ve 115E726