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Öğe Anti-inflammatory effects of hyperbaric oxygen on irradiated laryngeal tissues(Assoc Brasileira Otorrinolaringologia & Cirurgia Cervicofacial, 2018) Aricigil, Mitat; Dundar, Mehmet Akif; Yucel, Abitter; Arbag, Hamdi; Arslan, Abdullah; Aktan, Meryem; Findik, SidikaIntroduction: To manage the complications of irradiation of head and neck tissue is a challenging issue for the otolaryngologist. Definitive treatment of these complications is still controversial. Recently, hyperbaric oxygen therapy is promising option for these complications. Objective: In this study, we used biochemical and histopathological methods to investigate the efficacy of hyperbaric oxygen against the inflammatory effects of radiotherapy in blood and laryngeal tissues when radiotherapy and hyperbaric oxygen are administered on the same day. Methods: Thirty-two Wistar Albino rats were divided into four groups. The control group was given no treatment, the hyperbaric oxygen group was given only hyperbaric oxygen therapy, the radiotherapy group was given only radiotherapy, and the radiotherapy plus hyperbaric oxygen group was given both treatments on the same day. Results: Histopathological and biochemical evaluations of specimens were performed. Serum tumor necrosis factor-alpha, interleukin-1 beta, and tissue inflammation levels were significantly higher in the radiotherapy group than in the radiotherapy plus hyperbaric oxygen group, whereas interteukin-10 was higher in the radiotherapy plus hyperbaric oxygen group. Conclusion: When radiotherapy and hyperbaric oxygen are administered on the same day, inflammatory cytokines and tissue inflammation can be reduced in an early period of radiation injury. (C) 2017 Associacao Brasileira de Otorrinolaringologia e Cirurgia Cervico-Facial. Published by Elsevier Editora Ltda.Öğe Computed Tomography Analysis of Nasal Anatomy in Dorsal Preservation Rhinoplasty(Oxford Univ Press Inc, 2022) Eravci, Fakih Cihat; Ozer, Halil; Arbag, Hamdi; Eryilmaz, Mehmet Akif; Aricigil, Mitat; Dundar, Mehmet AkifBackground Subdorsal septal resection and radix osteotomy are distinctive surgical steps in preservation rhinoplasty. Objectives The aim of this study was to evaluate the nasal bone thickness, the level of the septal bony-cartilaginous junction (K area), and the distances of the frontal sinus and skull base from the transverse osteotomy line in the Turkish population by means of conventional computed tomography (CT). Methods A retrospective evaluation was made of 203 consecutive preoperative paranasal CT scans of patients (classified in terms of age and gender) who had undergone rhinoplasty surgery between January 2020 and June 2021. The nasal bone thickness at the medial canthus level, and the distances between the transverse osteotomy line and the K area, the frontal sinus, and the cribriform plate were measured. Results The mean measurements were similar in terms of age groups (P = 0.402, P = 0.542, P = 0.134 and P = 0.276 for ages 18-30, 30-40, 40-50, and >50 years, respectively). The mean nasal bone thickness and the distance between the transverse osteotomy line and the K area showed statistical significance (P = 0.001 and P = 0.001, respectively). In both genders, the mean distances between the transverse osteotomy line and the frontal sinus and the cribriform plate were similar (P = 0.921 and P = 0.280, respectively). The nasal bone was thinner and the K area position more cephalic in females. Conclusions CT plays an important role in preoperative planning. The need for resection of the ethmoid perpendicular bone may be greater in males when lowering the dorsal hump, and hence they may be more prone to skull base complications. It is therefore necessary to be more careful in the surgical stage of subdorsal septal excision in males.Öğe Confirmation of anatomical proximities in endoscopic sinus surgery with computer tomography: A cadaveric study(Bayrakol Medical Publisher, 2023) Erdem, Rukiye Ozcelik; Dundar, Mehmet Akif; Aricigil, Mitat; Arbag, HamdiAim: The aim of this study was to investigate the confirmation of anatomical proximities between endoscopic sinus surgery with computer tomography. Material and Methods: This study was done on 5 fresh frozen cadaver heads between May 2017 to June 2018. High-resolution computed tomography (HRCT) was taken before the operations. Firstly uncinectomy was done. Then all stages of functional endoscopic sinus surgery (FESS), which contains anteriorposterior ethmoidectomy, dissection of the sphenoid sinus and frontal recess, and maxillary sinusotomy were performed from anterior to posterior. Distances between each other landmarks and distances to the nasal vestibule were measured during the surgery. All measurements taken during dissection were measured on the coronal, axial, and sagittal section HRCT. Dissection data were compared with radiological data. Results: As a result of comparing the radiological data and dissection data, there was no significant difference between the data obtained from the sagittal section and the dissection data. A significant difference (P=0.03) was found between the dissection and radiological evaluation in the coronal section except for the measurements of SO-UT (p=0.853) and MP-SA (p=0.972), and in the axial section except for the measurements of the SO-C (p=0.579) and MP-SA (p=1). Discussion: Measurements obtained in the paranasal sinus CT can be used during FESS. While the data obtained in the sagittal section are suitable for the operation plan and can be used directly, the coronal and axial section are not.Öğe Effect of methylprednisolone loaded poly lactic-co-glycolic acid (PLGA) bioabsorbable nanofibers on tendon healing and adhesion formation(Elsevier, 2023) Zuhour, Moath; Gunes, Cansu; Findik, Siddika; Dundar, Mehmet Akif; Gok, Orhan; Altuntas, ZeynepBackground: Nanomaterials have been widely used in many fields such as vaccination and drug delivery. Beside its behavior as a degradable physical barrier, it can provide a controlled drug release. Tendon healing is a process full of complications, one of which is adhesion caused by excessive fibrosis.Aim: In this study, we aimed to prevent adhesion formation by using methylprednisolone (MP) loaded Poly lactic-co-glycolic acid (PLGA) mats. We used PLGA mats as both, biodegradable physical barrier to reduce the contact between surrounding tissues and healing tendon and as a drug delivery vehicle to release the antifibrotic MP with a controlled pattern.Methods: MP-loaded PLGA nanofiber mats were produced using electrospinning technique under optimized pa-rameters. To find the optimal MP dose, the drug was loaded in 15%, 25% and 35% concentrations. In vitro analysis included FT-IR, antibacterial, water absorption, biodegradability and drug release behavior tests. 70 rats' tendons were used for this study. After scarification of the rats, tendons were analyzed in terms of macroscopic, histopathological and biomechanical evaluation.Results: The neat PLGA and 15%, 25%, and 35% MP-loaded nanofibers lost 47%, 83%, 88%, and 97% of their initial weights at the end of the 8 weeks' degradation process. Within the first 24 h, mats including higher drug concentrations showed more initial release burst effect than samples loaded with lower concentrations. Cumu-lative drug release at 24 h was 29.5%, 27.6%, and 24.7% for PLGA nanofiber samples containing 15%, 25%, 35% MP, respectively. Macroscopically, When the groups were compared, no statistically significant difference was found between group 1 (no surgical intervention) and group 5 (25% MP/PLGA) in terms of length, characteristics and degree of the adhesion. Comparing to other groups statistically significant atrophic effect was found in group 6 (35% MP/PLGA).Conclusion: 25% MP-loaded PLGA reduces the formation of adhesions macroscopically comparable to tendons that didn't receive any surgical intervention. Microscopically, it provides better tendon healing compared to tendons that received only surgical repair or surgery + neat PLGA. Methylprednisolone did not only add an antibacterial effect to PLGA but also increased the hydrophilic property and degradation rate of PLGA. Increased steroid concentration also leads to atrophy at the healing tendons which can be prevented by modifying the PLGA design.Öğe The Effect of Rhinoplasty Dissection Planes (Sub-SMAS, Subperichondrial, and Subperiosteal) on the Viability of Diced Cartilage Grafts in a Rabbit Model(Oxford Univ Press Inc, 2023) Eravci, Fakih Cihat; Kaplan, Omer; Oltulu, Pembe; Arbag, Hamdi; Eryilmaz, Mehmet Akif; Aricigil, Mithat; Dundar, Mehmet AkifBackground Dorsal preservation surgeries in which the subperichondral and subperiosteal planes are used to elevate the soft tissue envelope of the nose have become increasingly widespread because they can reduce postoperative edema and promote faster healing. However, the effects of surgical dissection planes on the viability of cartilage grafts are not known. Objective The aim of this study was to determine, in a rabbit model, the viability of diced cartilage grafts in different rhinoplasty dissection planes (sub-superficial musculoaponeurotic system [SMAS], subperichondral, subperiosteal). Methods Diced cartilage samples were placed in the sub-SMAS, subperichondrial, and subperiosteal planes, and after 90 days, histopathologic analysis was performed. Cartilage graft viability was evaluated based on the loss of chondrocyte nuclei in the lacuna, the presence of peripheral chondrocyte proliferation, and the loss of matrix metachromasia in the chondroid matrix. Results The median [interquartile range] percentages of live chondrocyte nucleus viability in the sub-SMAS, subperichondrial, and subperiosteal groups were 67.5% [18.75%] (range, 60%-80%), 35% [17.5%] (range, 20%-45%), and 20% [30.0%] (range, 10%-45%), respectively; and the percentages of peripheral chondrocyte proliferation were 80.0% [22.5%] (range, 60%-90%), 30% [28.75%] (range, 15%-60%), and 20% [28.75%] (range, 5%-60%), respectively. There was strong statistical significance in both parameters (P = .001). Intergroup examination revealed a difference between the sub-SMAS and the other surgical planes (P = .001 for both parameters). A smaller loss of chondrocyte matrix was observed in the sub-SMAS group compared with the other 2 groups, which supports the findings of cartilage viability (P = .006). Conclusions Elevating the soft tissue envelope of the nose in the sub-SMAS surgical plane preserves the viability of cartilage grafts better than subperichondrial and subperiosteal elevation.Öğe Enhancement of PCL/PLA Electrospun Nanocomposite Fibers Comprising Silver Nanoparticles Encapsulated with Thymus Vulgaris L. Molecules for Antibacterial and Anticancer Activities(Amer Chemical Soc, 2022) Cimen, Cansu Gunes; Dundar, Mehmet Akif; Kars, Meltem Demirel; Avci, AhmetSilver nanoparticles (AgNPs) have been recognized for their outstanding antibacterial activities, which are required for antibacterial coating materials in therapeutic applications. A bacterial resistant electrospun nanofibrous mat made of polycaprolactone (PCL) in combination with polylactide acid (PLA) containing silver nanoparticles encapsulated with Thymus vulgaris L. (thyme) extract (eAgNPs) was fabricated in order to assess the potential of applicability in biomedical applications such as cancer treatment, wound healing, or surgical sutures. In the current study, PCL and PLA used as the basis polymers were blended with biosynthesized eAgNPs, pure AgNPs, and thyme extract (TE) to observe the effects of additives in terms of antibacterial and anticancer activity and morphologic, thermal, mechanical, biocompatibility, and biodegradability properties. The biological characteristics of fabricated electrospun nanofibrous mats were evaluated in vitro. Physicochemical characteristics of the nanofibrous mats were examined by UV-vis spectrophotometry, scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), Fourier-transform infrared spectroscopy (FTIR), mechanical tensile testing, X-ray diffraction (XRD), thermogravimetric examination (TGA), and water contact angles (WCAs). The results showed that a biodegradable nanofiber scaffold with a mean fiber diameter of 280 nm is morphologically homogeneous and highly hydrophobic, has higher tensile strength than PCL/PLA nanocomposite fiber, and is resistant to Escherichia coli and Staphylococcus aureus. The cytotoxic and anticancer properties of nanomaterials were defined using L929 and SK-MEL-30 cells. The developed material inhibited cell proliferation and led to apoptosis of cell lines. It can be suggested that the use of Thymus vulgaris L. extract-encapsulated silver nanoparticle-doped PCL/PLA nanofibers produced by the electrospinning method has the potential for cancer therapy in skin tumor cell lines.Öğe Evaluation of the efferent auditory system in COVID-19 adult patients(Taylor & Francis Ltd, 2022) Emekci, Tugba; Dundar, Mehmet Akif; Kirazli, Gulce; Kilinc, Fatma Men; Cengiz, Deniz Ugur; Karababe, Ercan; Inceoglu, FeyzaBackground The short- and long-term effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on the medial olivocochlear reflex and outer hair cells in the cochlea remain largely unclear. Aims The aim of this study was to investigate the efferent auditory system effects in adult patients with COVID-19. Materials and methods The study included 18-50 years old 44 volunteers: 26 individuals (52 ears) with COVID-19 in the study group and 18 healthy individuals (36 ears) in the control group. Otolaryngological examination, immitancemetric evaluation, distortion product otoacoustic emission (DPOAE), contralateral acoustic stimulation with DPOAE, audiometric evaluation, and high frequency audiometric evaluation were performed in all individuals participating in the study. Results In our study, patients with COVID-19 had significantly lower DPOAE results with or without broadband noise at only 6 kHz frequency and contralateral suppression results at all frequencies compared to healthy individuals. A statistically significant difference was found between the study and control groups according to whether the participants had a response in the high frequency audiometry at 12 and 16 kHz frequencies. Conclusions COVID-19 affects many systems in the body. As a result of the findings obtained in the present study, it is shown that the auditory efferent system may also be affected.Öğe Foix-Chavany-Marie syndrome after an isolated pontine infarct: A 7-year follow-up(Medknow Publications & Media Pvt Ltd, 2015) Kozak, Hasan Huseyin; Uca, Ali Ulvi; Dundar, Mehmet Akif[Abstract Not Availabe]Öğe Giant Epidermal Inclusion Cyst Over the Parotid Gland Mixing Parotid Tumor(Lippincott Williams & Wilkins, 2014) Altuntas, Zeynep; Ince, Bilsev; Dadaci, Mehmet; Dundar, Mehmet Akif[Abstract Not Availabe]Öğe Giant Trichilemmal Cyst of the Submental Region(Lippincott Williams & Wilkins, 2014) Dundar, Mehmet Akif; Varsak, Yasin Kursad; Kozacioglu, Sumeyye; Arbag, Hamdi[Abstract Not Availabe]Öğe Isolated Congenital Nasal Bifid Septum Separated by a Wide Layer of Soft Tissue(Korean Soc Plastic & Reconstructive Surgery, 2015) Karacor-Altuntas, Zeynep; Dundar, Mehmet Akif; Dadaci, Mehmet; Ince, Bilsev[Abstract Not Availabe]Öğe Melatonin prevents possible radiotherapy-induced thyroid injury(Taylor & Francis Ltd, 2017) Aricigil, Mitat; Dundar, Mehmet Akif; Yucel, Abitter; Eryilmaz, Mehmet Akif; Aktan, Meryem; Alan, Mehmet Akif; Findik, SidikaPurpose: We aimed to investigate the protective effect of melatonin in radiotherapy-induced thyroid gland injury in an experimental rat model.Materials and methods: Thirty-two rats were divided into four groups: the control group, melatonin treatment group, radiotherapy group and melatonin plus radiotherapy group. The neck region of each rat was defined by simulation and radiated with 2 Gray (Gy) per min with 6-MV photon beams, for a total dose of 18Gy. Melatonin was administered at a dose of 50mg/kg through intraperitoneal injection, 15min prior to radiation exposure. Thirty days after the beginning of the study, rats were decapitated and analyses of blood and thyroid tissue were performed.Results: Tumor necrosis factor- (TNF-), interleukin-1 beta (IL-1), thiobarbituric acid reactive substances (TBARS) and nitric oxide (NO) levels in the radiotherapy group were significantly higher than those in the melatonin plus radiotherapy group (p<.05), whereas interleukin-10 (IL-10) and glutathione (GSH) values were higher in the melatonin plus radiotherapy group (p<.05). The infiltration of inflammatory cells and percentage of apoptosis in the radiotherapy group were significantly higher than those in the melatonin plus radiotherapy group (p<.05).Conclusions: Melatonin helped protect thyroid gland structure against the undesired cytotoxic effects of radiotherapy in rats.Öğe Minimally Invasive Endoscopic Retrosigmoid Approach to the Cerebellopontine Angle Using a Novel Surgical Instrument: A Cadaveric Study(Aves, 2018) Aricigil, Mitat; Arbag, Hamdi; Dundar, Mehmet Akif; Aziz, Suhayb Kuria; Yilmaz, Mehmet TugrulOBJECTIVES: In this study, we aimed to describe how endoscopes show the neural and vascular structures at the cerebellopontine angle (CPA) through a minimal craniotomy in a well-described anatomic point in the retrosigmoid legion and at the same time, evaluate the endoscopic anatomic exposure and maneuverability. We planned to use the new surgical instrument (endoscope cannula), which we designed on fresh frozen cadavers to simulate a real surgical procedure. MATERIALS and METHODS:The surgical procedure was planned to be performed on 20 sides of 10 fresh cadaver heads. The distance between the aster ion and mastoid process was determined, and the midpoint was then marked. From this midpoint, a craniotomy 2 cm in size was posteriorly made. The endoscope cannula together with 0 degrees or 30 degrees endoscopes was inserted to capture the panoramic views of the neurovascular structures in CPA. Endoscopic anatomic exposure and maneuverability wee evaluated using 0 degrees and 30 degrees endoscopes with/without the endoscope cannula. RESULTS: The surgeon could easily use both hands during the surgical simulation, and maneuverability was seen to increase in CPA with the use of the endoscope cannula. CONCLUSION:The surgeon can work actively with both hands when the endoscopes and the endoscope cannula are used together. We believe that owing to this, the surgeon's maneuverability would increase and a more effective minimally invasive endoscopic retrosigmoid surgery would ensue.Öğe Sudden bilateral hearing loss after organophosphate inhalation(Kare Publ, 2016) Dundar, Mehmet Akif; Derin, Serhan; Aricigil, Mitat; Eryilmaz, Mehmet AkifSudden bilateral hearing loss are seen rarely and the toxic substance exposure constitutes a small part of etiology. A Fifty-eight-year-oldwoman admitted to our clinic with sudden bilateral hearing loss shortly after chlorpyrifos-ethyl exposure. Otolaryngologic examination findings were normal. The patient had 40 dB sensorineural hearing loss (SNHL) on the right ear and 48 dB SNHL on the left ear. Additional diagnostic tests were normal. The conventional treatment for sudden hearing loss was performed. On the second week following organophosphate (OP) exposure the patient's hearing loss almost completely resolved. OP's are heavily used in agriculture and should be taken into consideration as an etiologic factor in sudden hearing loss. Copyright (C) 2016 The Emergency Medicine Association of Turkey. Production and hosting by Elsevier B.V. on behalf of the Owner. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Öğe vHIT results with the synapsis system according to clinicians' dominant hand use(Ios Press, 2023) Emekci, Tugba; Dundar, Mehmet Akif; Kirazli, Gulce; Inceoglu, Feyza; Cengiz, Deniz Ugur; Kilinc, Fatma Men; Karababa, ErcanBACKGROUND/OBJECTIVE: There exists limited information in the literature on dominant hand preference in relation with vHIT applications. The present study aimed to examine the relationship between the clinician's dominant use of rightor left-hand and vHIT results. METHODS: A Synapsys vHIT Ulmer device was used in the study. The tests were administered by 3 clinicians experienced in vHIT, 2 of whom were right-handed and 1 left-handed. The test was applied to the 94 participants three times, one week apart. RESULTS: In this study, the correlation between right-handed clinicians and left-handed clinicians was examined, and in all SCCs, namely RA, LA, RL, LL, RP and LP, a moderate positive significant correlation was found between right-handed1 and right-handed2, between right-handed1 and left-handed, and between right-handed2 and left-handed. CONCLUSIONS: In this study, these findings suggested that measures were reliable across test sessions regardless of hand dominancy (right or left). Based on the vHIT results we obtained with three different right- or left-handed clinicians, the clinician should evaluate the results according to the dominant side. Keywords: Hand-dominance, left-hand dominance, right-hand dominance,
