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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14288/3
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Publication Metadata only TNF-alpha inhibition prevents cognitive decline and maintains hippocampal BDNF levels in the unpredictable chronic mild stress rat model of depression(Elsevier, 2015) Şahin, Tuğce Demirtaş; Karson, Ayşe; Yazır, Yusufhan; Bayramgürler, Dilek; Utkan, Tijen; Department of Psychology; Department of Psychology; Balcı, Fuat; Faculty Member; College of Social Sciences and Humanities; 51269Previous findings have shown that patients with depression express higher levels of proinflammatory cytokines such as TNF-alpha and IL-6. We have recently found that Infliximab (a TNF-alpha inhibitor) decreased anhedonia and despair-like behavior in the rat unpredictable chronic mild stress (UCMS) model of depression suggesting that inflammation might play an important role in depression. An increasing number of studies suggest that inflammation is also associated with cognitive impairments. The current study aimed to investigate the effect of UCMS on the cognitive performance of rats and their hippocampal BDNF levels and the effect of chronic Infliximab (5 mg/kg/weekly, i.p.) treatment on these measures. Rats were subjected to different types of stressors daily for a period of 56 days to induce depression-like state. The UCMS resulted in impairments in spatial and emotional memory acquisition and retention with no effect on the level of locomotor activity. These behavioral effects of UCMS were accompanied by reduction in the level of BDNF in the CA1 and CA3 regions of the hippocampus. Chronic Infliximab treatment prevented the UCMS-induced cognitive impairments as well as the reduction in the levels of hippocampal brain-derived neurotrophic factor (BDNF). These results suggest that Infliximab improves the spatial and emotional memory impairments induced by chronic stress in rats likely through its effects on hippocampal function by modulating inflammation.Publication Metadata only Neurotrophin-3 provides neuroprotection via TrkC receptor dependent pErk5 activation in a rat surgical brain injury model(Academic Press Inc Elsevier Science, 2018) Akyol, Onat; Sherchan, Prativa; Yilmaz, Gokce; Reis, Cesar; Ho, Wingi Man; Wang, Yuechun; Huang, Lei; Zhang, John H.; N/A; Solaroğlu, İhsan; Faculty Member; School of Medicine; 102059Background: Surgical brain injury (SBI) which occurs due to the inadvertent injury inflicted to surrounding brain tissue during neurosurgical procedures can potentiate blood brain barrier (BBB) permeability, brain edema and neurological deficits. This study investigated the role of neurotrophin 3 (NT-3) and tropomyosin related kinase receptor C (TrkC) against brain edema and neurological deficits in a rat SBI model. Methods: SBI was induced in male Sprague Dawley rats by partial right frontal lobe resection. Temporal expression of endogenous NT-3 and TrkC was evaluated at 6, 12, 24 and 72 h after SBI. SBI rats received recombinant NT-3 which was directly applied to the brain surgical injury site using gelfoam. Brain edema and neurological function was evaluated at 24 and 72 h after SBI. Small interfering RNA (siRNA) for TrkC and Rap1 was administered via intracerebroventricular injection 24 h before SBI. BBB permeability assay and western blot was performed at 24 h after SBI. Results: Endogenous NT-3 was decreased and TrkC expression increased after SBI. Topical administration of recombinant NT-3 reduced brain edema, BBB permeability and improved neurological function after SIR Recombinant NT-3 administration increased the expression of phosphorylated Rap1 and Erk5. The protective effect of NT-3 was reversed with TrkC siRNA but not Rap1 siRNA. Conclusions: Topical application of NT-3 reduced brain edema, BBB permeability and improved neurological function after SBI. The protective effect of NT-3 was possibly mediated via TrkC dependent activation of Erk5.Publication Metadata only Jendrassik maneuver effect on spinal and brainstem reflexes(Springer, 2019) Kumru, Hatice; Opisso, Eloy; Valls-Sole, Josep; Cecen, Serpil; N/A; Ertuğlu, Lale Aslıhan; Aydın, Aslı; Türker, Kemal Sıtkı; Undergraduate Student; Undergraduate Student; Faculty Member; School of Medicine; School of Medicine; School of Medicine; Koç University Hospital; N/A; N/A; 6741The effect of Jendrassik Maneuver (JM) has been extensively studied on monosynaptic reflexes in numerous muscles below the level at which the maneuver was performed. Here we hypothesize that the effect of JM could be observed also on other reflexes, indicating a widespread influence of performing a motor act such as the JM. We examined polysynaptic reflexes caudal (i.e., the withdrawal reflex of the lower extremities) and rostral (i.e., the blink reflex to supraorbital nerve stimulation) to the level of JM contraction. We have assessed soleus tendon (T) reflex; withdrawal reflex in tibialis anterior and soleus muscle; blink reflex (BR), blink reflex excitability recovery curve (BR-ER) and prepulse inhibition of the blink reflex. Our results showed that (1) T-reflex amplitude increased during JM and decreased just after and 15 min after JM; (2) no change in the withdrawal reflex; (3) R2 area of BR reduced significantly just after or 15 min after JM; (4) Prepulse inhibition in BR reduced significantly during JM; (5) no change in BR-ER. Our results indicate that JM leads to generalized effects on neural excitability at both caudal and rostral levels. Furthermore, JM has a selective effect on excitability of reflex circuitries.Publication Metadata only A multicenter international study to evaluate different aspects of relationship between MS and pregnancy(Sage, 2019) Zakaria, M.; Alroughani, R.; Moghadasi, A. N.; Terzi, M.; Sen, S.; Koseoglu, M.; Efendi, H.; Soysal, A.; Gozubatik-Celik, G.; Ozturk, M.; Sahraian, M.; Akinci, Y.; Kaya, Z. E.; Saip, S.; Siva, A.; N/A; Department of Industrial Engineering; Department of Industrial Engineering; Altıntaş, Ayşe; Gönen, Mehmet; Faculty Member; Faculty Member; School of Medicine; College of Engineering; 11611; 237468N/APublication Metadata only Face memory and emotion recognition in individuals diagnosed with schizophrenia, their unaffected siblings, individuals with ultra-high risk for psychosis and healthy controls(Elsevier Science, 2022) Sağdıç, Meylin; İzgi, Büşra; Erciş, Mete; Üçok Alp; Eser, Hale Yapıcı; Kuşçu, Kemal; Doctor; Other; School of Medicine; Koç University Hospital; 134359; N/APublication Metadata only A multidisciplinary clinical approach to facioscapulohumeral muscular dystrophy orthopedic surgery in facioscapulohumeral dystrophy(Literatura Medica, 2018) N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; Çakmak, Özgür Öztop; Eren, İlker; Aslanger, Ayça Dilruba; Günerbüyük, Caner; Kayserili, Hülya; Oflazer, Piraye; Şar, Cüneyt; Demirhan, Mehmet; Özdemir, Yasemin Gürsoy; Faculty Member; Faculty Member; Doctor; Teaching Faculty; Faculty Member; Faculty Member; Doctor; Faculty Member; Faculty Member; School of Medicine; School of Medicine; N/A; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; Koc University Hospital; 107818; 168021; N/A; 380939; 7945; N/A; N/A; 9882; 170592Background - Impaired shoulder function is the most disabling problem for daily life of Fascioscapulohumeral muscular dystrophy (FSHD) patients. Scapulothoracic arthrodesis can give a high impact to the functionality of patients. Here we report our experience with scapulothoracic arthrodesis and spinal stenosis surgery in FSHD patients. Patients and methods - 32 FSHD patients were collected between 2015-2016. Demographical and clinical features were documented. All the patients were neurologically examined. The Medical Research Council (MRC) and the FSHD evaluation scale was used to assess muscle involvement(1). Scapulothoracic arthrodesis and spinal stenosis surgeries were performed in eligible patients. Results - There were 16 male and 16 female (mean age 34.4 years; range 12-73) patients. 6 shoulders of 4 patients aged between 2132 years underwent scapulothoracic arthrodesis (two bilateral, one left and one right sided). Only one 63 years old female patient with severe hyperlordosis had spinal fusion surgery. All of the patients undergoing these corrective surgeries have better functionality in daily life, as well as superior shoulder elevation. Conclusion - Until the emergence and clinical use of novel therapeutics, surgical interventions are indicated in carefully selected patients with FSHD to improve arm movements, the posture and the quality of life of patients in general. Scapulothorosic arthrodesis is a management with good clinical results and patient satisfaction. In selected cases other corrective orthopedic surgeries like spinal fusion may also be considered.Publication Metadata only Long-term follow-up of five families from Turkey with UBQLN2 variants(Wiley, 2022) Durmus, Hacer; Cakar, Arman; Aysal, Fikret; Ertas, Mustafa; Parman, Yesim; N/A; Başak, Ayşe Nazlı; Faculty Member; School of Medicine; 1512Publication Metadata only Optimal location for eliciting the tibial H-reflex and motor response(Wiley, 2018) N/A; N/A; Özyurt, Mustafa Görkem; Shabsog, Mohammed Kamal Yahya; Dursun, Merve; Türker, Kemal Sıtkı; PhD Student; Undergraduate Student; Undergraduate Student; Faculty Member; Graduate School of Sciences and Engineering; School of Medicine; School of Medicine; School of Medicine; School of Medicine; N/A; N/A; N/A; 6741Introduction: Although there are numerous protocols to adjust the amplitude of the Hoffmann reflex (H-reflex) relative to the size of the direct motor response (M-response), the optimal stimulating location has not been described. We sought to determine the optimal positioning of the stimulating cathode when evoking the tibial nerve H-reflex and M-response. Methods: A small cathode was placed on defined points in the popliteal fossa while an anode was fixed on the patella. The tibial nerve was stimulated electrically, and the response of the soleus muscle was recorded using intramuscular and surface electromyography. Results: We found that more-lateral points along a line drawn across the popliteal fossa were the best locations to obtain only the M-response, whereas stimulating the midpoint was optimal for obtaining only the H-reflex. Discussion: By using specified locations for electrical stimulation to evoke H-reflex and M-response, the functionality of the tibial nerve can be assessed.Publication Metadata only Long-term results of Gamma Knife radiosurgery for facial nerve schwannomas(Taylor & Francis, 2020) Şirin, Alperen; Yılmaz, Meltem; Şengöz, Meriç; N/A; N/A; Akyoldaş, Göktuğ; Peker, Selçuk; Faculty Member; Faculty Member; School of Medicine; School of Medicine; 203677; 11480Objective: Long-term outcomes of eleven cases of facial nerve schwannoma were evaluated and the related literature was reviewed to determine the efficacy of Gamma Knife radiosurgery for treating patients with facial nerve schwannoma. Methods: Eleven patients with facial nerve schwannoma (7 women and 4 men; mean age, 44.2 years; range, 19-73 years) underwent Gamma Knife radiosurgery. The most common symptoms were facial palsy (n = 10) and hearing loss (n = 7). Five patients presented with headache. Two patients had undergone prior resection. The patients' clinical and radiographic data were evaluated retrospectively. Results: For the 11 cases of facial nerve schwannoma, mean tumor volume was 3.1 cm(3) (range, 0.4-7.4 cm(3)) and the mean marginal dose applied was 11.9 Gy (range, 11-13 Gy). The mean follow-up period was 84.3 months (range, 66-117 months). Tumor control was achieved in all patients. At the time of writing, four patients experienced tumor volume regression and the other seven were in stable condition. During follow-up, nine patients experienced no change in their facial function, two experienced deteriorated facial function, and none developed new facial palsy. Ten patients who had serviceable hearing prior to Gamma Knife radiosurgery retained their hearing. Conclusions: Gamma Knife radiosurgery achieves excellent results with respect to tumor control for 7 years on average. In addition, Gamma Knife radiosurgery provides good results in facial nerve and hearing function at long term. Our series demonstrates that Gamma Knife radiosurgery is an effective and safe treatment for patients with either primary or residual facial nerve schwannoma.Publication Metadata only Cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS): an important cause of late-onset ataxia with unique clinical features(Springer Heidelberg, 2022) Çakar, Arman; Şahin, Erdi; Tezel, Seden; Candayan, Ayşe; Samancı, Bedia; Battaloğlu, Esra; Bilgiç, Başar; Hanağası, Haşmet; Durmuş, Hacer; Parman, Yeşim; N/A; Başak, Ayşe Nazlı; Faculty Member; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); School of Medicine; 1512Cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) is a late-onset, slowly progressive disorder characterized by cerebellar ataxia, sensory neuropathy and bilateral vestibulopathy. Recently, a biallelic intronic AAGGG repeat expansion, (AAGGG)(exp), in the Replication Factor C1 (RFC1) gene was identified as the cause of this disorder. In this study, we describe the phenotypic features of five patients from five different families diagnosed as CANVAS. The mean age at onset was 49.00 +/- 9.05 years (between 34 and 56 years) and the most frequent presenting symptom in CANVAS was gait ataxia, followed by sensory disturbances. Persistent coughing was prominent in three patients, and it preceded the onset of ataxia and sensory symptoms in two patients. Parental consanguinity was present in three patients. Two patients showed symptoms or signs suggesting autonomic involvement. Sural nerve biopsy revealed axonal neuropathy in two patients. The mean age at onset was 49.00 +/- 9.05 years (between 34 and 56 years) and the most frequent presenting symptom in CANVAS was gait ataxia, followed by sensory disturbances. Persistent coughing was prominent in three patients, and it preceded the onset of ataxia and sensory symptoms in two patients. Parental consanguinity was present in three patients. Two patients showed symptoms or signs suggesting autonomic involvement. Sural nerve biopsy revealed axonal neuropathy in two patients. Our study describes clinical findings, histopathological features and diagnostic clues of CANVAS from Turkey, a country with a high consanguineous marriage rate. Repeat expansion in the RFC1 gene should be considered in all cases with late-onset ataxia, especially when sensory disturbances, vestibular involvement and persistent coughing coexist.