Change in gene expression levels of GABA, glutamate and neurosteroid pathways due to acoustic trauma in the cochlea.

The characteristic feature of noise-induced hearing loss (NIHL) is the loss or malfunction of the outer hair cells (OHC) and the inner hair cells (IHC) of the cochlea. 90-95% of the spiral ganglion neurons, forming the cell bodies of cochlear nerve, synapse with the IHCs. Glutamate is the most potent excitatory neurotransmitter for IHC-auditory nerve synapses. Excessive release of glutamate in response to acoustic trauma (AT), may cause excitotoxicity by causing damage to the spiral ganglion neurons (SGN) or loss of the spiral ganglion dendrites, post-synaptic to the IHCs. Another neurotransmitter, GABA, plays an important role in the processing of acoustic stimuli and central regulation after peripheral injury, so it is potentially related to the regulation of hearing function and sensitivity after noise. The aim of this study is to evaluate the effect of AT on the expressions of glutamate excitotoxicity, GABA inhibition and neurosteroid synthesis genes.We exposed 24 BALB/c mice to AT. Controls were sacrificed without exposure to noise, Post-AT(1) and Post-AT(15) were sacrificed on the 1st and 15th day, respectively, after noise exposure. The expressions of various genes playing roles in glutamate, GABA and neurosteroid pathways were compared between groups by real-time PCR.Expressions of Cyp11a1, Gls, Gabra1, Grin2b, Sult1a1, Gad1, and Slc1a2 genes in Post-AT(15) mice were significantly decreased in comparison to control and Post-AT(1) mice. No significant differences in the expression of Slc6a1 and Slc17a8 genes was detected.These findings support the possible role of balance between glutamate excitotoxicity and GABA inhibition is disturbed during the post AT days and also the synthesis of some neurosteroids such as pregnenolone sulfate may be important in this balance.

A Prospective Experimental Study on the Protective Effect of Resveratrol against Amikacin-Induced Ototoxicity in Rats.

OBJECTIVE: The purpose of this study was to evaluate the protective effect of resveratrol against amikacin-induced ototoxicity in rats by otoacoustic emission and histopathology of the cochlea. MATERIALS AND METHODS: This study was conducted with 31 Sprague Dawley adult female rats that were 20-21 weeks old and 190-245 g in weight. Before the drug administration, distortion product otoacoustic emission (DPOAE) tests were performed in both ears of each rat. The rats were divided into four groups. Group 1 (n=7) received ethanol 1cc 4%, Group 2 (n=8) received 600 mg/kg amikacin, Group 3 (n=8) received 10 mg/kg resveratrol and 600 mg/kg amikacin, and Group 4 (n=8) received 1cc resveratrol at 10 mg/kg. The drugs were administered once a day for 21 consecutive days. Control DPOAE tests were performed at the 7th, 14th, and 21st days after the administration of drugs. At the end of the study, the rats were sacrificed and their cochleae were dissected. The cochleae were evaluated for histopathologic changes. RESULTS: There was no statistically significant difference in the DPOAE measurements before the procedure between groups. The DPOAE measurements significantly decreased after the procedure in the amikacin group. There was no statistically significant difference in DPOAE measurements after the procedure in the amikacin + resveratrol, resveratrol, and ethanol groups. The histopathologic findings supported these results. CONCLUSION: We found that if resveratrol is administered with amikacin, the severity of amikacin-induced hearing loss is decreased. These findings suggest that resveratrol, a strong antioxidant, has a protective effect in amikacin ototoxicity.

Pencil in the pharynx: Case report of a penetrating foreign body.

Pharyngeal foreign bodies are commonly encountered in otolaryngological practice. However, in certain instances, particularly in cases of penetrating injuries, major vascular damage leads to severe morbidity and mortality. Management of these cases includes airway protection, bleeding control, imaging of major vascular injury, and prophylactic antibiotics. The case of a 2-year-old patient with penetrating pharyngeal foreign body is described in the present report.

Effect of Septoplasty on Voice Quality: A Prospective-Controlled Trial.

OBJECTIVES: The purpose is to investigate effect of septoplasty and widened nasal patency on voice quality. METHODS: Fifty patients who undergone septoplasty were included in the study. Thirty-three people who had similar age and distribution were enrolled as control group. Before and 1 and 3 months after surgery, anterior rhinomanometry, voice analysis by Multi-Dimensional Voice Program, and spectrographic analysis were performed to patients. The recordings of /a/ vowel were used to evaluate average fundamental frequency (F0), jitter percent, and shimmer percent. In spectrographic analyses, F3-F4 values for the vowels /i, e, a, o, and u/, nasal formant frequencies of the consonants /m/ and /n/ in the word /mini/, and 4 formant frequencies (F1, F2, F3, and F4) for nasalized /i/ vowel following a nasal consonant /n/ in the word /mini/ were compared. The differences in nasal resonance were evaluated. All patients were asked whether change in their voices after the surgery. Preoperative and postoperative voice parameters and anterior rhinomanometry results were compared separately with the control group as well as in the patient group itself. RESULTS: Preoperative total nasal resistance (TNR) values of patients were higher than the control group (P=0.001). TNR values of patients measured one day before surgery and after surgery in the 1st and 3rd months were different and these differences were significant statistically (P=0.001). There was no significant difference between the voice analysis parameters in preoperative, postoperative 1st, and 3rd months. As a result of their subjective reviews, 12 patients (36%) noted their voices were better than before surgery and 20 patients (61%) noted no change before and after surgery. CONCLUSION: Providing widened nasal cavity has no effect on voice quality.

Evaluation of the effect of intranasal infiltrated botulinum toxin-A on a model of allergic rhinitis in rabbits: An Experimental Study.

INTRODUCTION: Allergic Rhinitis (AR) effects 20-40% of the global population and its prevalance increases. Medical treatment and immunotherapy could be used in AR management. But they are not definitive solution. Medical treatment must be used a long time and has side effects. Immunotherapy cannot be applied to every patient and it also takes a long time. The aim of this study is to evaluate symptomatic and histopathological effects of intranasal infiltrated Botulinum Toxin-A (Btx-A) on an animal model of AR. MATERIAL-METHOD: 15 rabbits were divided into 3 groups as control, disease and treatment. AR was formed in disease and treatment groups by intraperitoneal and intranasal ovalbumine. Allergic symptoms were observed and serum IgE levels were estimated to prove forming of AR. Btx-A was infiltrated in inferior turbinates of rabbits in treatment group. Rabbits were sacrified on 32nd day. Paranasal structures were disected and investigated histopathologically. RESULTS: Serous nasal discharge and sneezing were observed after ovalbumine applying in disease and treatment groups. Serum IgE levels on 21st day were higher than 1st day and this difference was significant statistically in disease and treatment groups. Serous discharge and sneezing decreased after Btx-A infiltration in treatment group. In histopathological examination, there were significant difference between disease and treatment group in terms of some histopathological findings. CONCLUSION: Considering the effect of Btx-A on AR in animal, it can be said that Btx-A can decrease symptoms and reorganize histopathological findings of AR.