Ototoxicity of boric acid powder in a rat animal model / Ototoxicidade de ácido bórico em pó em um modelo animal de rato

Abstract Introduction: Boric acid, which has antiseptic and acidic properties, is used to treat external and middle ear infections. However, we have not found any literature about the effect of boric acid powder on middle ear mucosa and inner ear. Objective: The purpose of this study is to investigate possible ototoxic effects of boric acid powder on cochlear outer hair cell function and histological changes in middle ear mucosa in a rat animal model. Methods: Twenty healthy, mature Wistar albino rats were used in this study. The rats were divided into two groups, Group A and Group B, each of which consisted of 10 rats. Initially, the animals in each group underwent distortion product otoacoustic emissions testing of their right and left ears. After the first distortion product otoacoustic emissions test, a surgical microscope was used to make a small perforation in both ears of the rats in each group, and a second distortion product otoacoustic emissions test was used to measure both ears in all of the rats. Boric acid powder was applied to the right middle ear of the rats using tympanic membrane perforation, and the distortion product otoacoustic emissions were measured immediately after the boric acid powder application. The histological changes and distortion product otoacoustic emissions were evaluated three days later in Group A and 40 days later in Group B. Results: No significant differences were found at all of the distortion product otoacoustic emissions frequencies. In Group A, mild inflammation of the middle ear mucosa was found on the third day after boric acid powder application. In Group B, boric acid powder caused mild inflammatory changes on the 40th day, which declined over time. Those changes did not lead to significant fibrosis within the mucosa. Conclusion: In rats, boric acid powder causes mild inflammation in middle ear mucosa and it has no ototoxic effects on cochlear outer hair cell function in the inner ear of rats.

Resumo Introdução: O ácido bórico, que tem propriedades antissépticas e ácidas, é usado para tratar infecções de orelha externa e média. No entanto, não encontramos literatura sobre o efeito do ácido bórico em pó sobre a mucosa da orelha interna e da orelha média. Objetivo: Investigar possíveis efeitos ototóxicos do ácido bórico em pó sobre a função das células ciliadas externas cocleares e alterações histológicas na mucosa da orelha média em um modelo animal de rato. Método: Vinte ratos Wistar albinos maduros e saudáveis foram usados neste estudo. Os ratos foram divididos em dois grupos, Grupo A e Grupo B, cada um dos quais com 10 ratos. Inicialmente, os animais de cada grupo foram submetidos a testes de emissões otoacústicas - produto de distorção, nas orelhas direita e esquerda. Após o primeiro teste de emissões otoacústicas - produto de distorção, utilizou-se um microscópio cirúrgico para fazer uma pequena perfuração em ambas as orelhas dos ratos em cada grupo, e um segundo teste de emissões otoacústicas - produto de distorção foi utilizado para medir e avaliar as orelhas em todos os ratos. O ácido bórico em pó foi aplicado na orelha média direita dos ratos utilizando perfuração da membrana timpânica e as emissões otoacústicas - produto de distorção foram medidas imediatamente após a aplicação de ácido bórico em pó. As alterações histológicas e emissões otoacústicas - produto de distorção foram avaliadas três dias depois no Grupo A e 40 dias depois no Grupo B. Resultados: Não foram encontradas diferenças significativas em todas as frequências da emissões otoacústicas - produto de distorção. No Grupo A, foi observada uma ligeira inflamação da mucosa da orelha média no terceiro dia após a aplicação de ácido bórico em pó. No Grupo B, o ácido bórico em pó causou leves alterações inflamatórias após 40 dias, que diminuíram ao longo do tempo. Essas alterações não levaram à fibrose significativa da mucosa. Conclusão: Em ratos, o ácido bórico em pó causa inflamação leve na mucosa da orelha média e não tem efeitos ototóxicos na função das células ciliadas externas da cóclea na orelha interna.

Ototoxicity of boric acid powder in a rat animal model.

INTRODUCTION: Boric acid, which has antiseptic and acidic properties, is used to treat external and middle ear infections. However, we have not found any literature about the effect of boric acid powder on middle ear mucosa and inner ear. OBJECTIVE: The purpose of this study is to investigate possible ototoxic effects of boric acid powder on cochlear outer hair cell function and histological changes in middle ear mucosa in a rat animal model. METHODS: Twenty healthy, mature Wistar albino rats were used in this study. The rats were divided into two groups, Group A and Group B, each of which consisted of 10 rats. Initially, the animals in each group underwent distortion product otoacoustic emissions testing of their right and left ears. After the first distortion product otoacoustic emissions test, a surgical microscope was used to make a small perforation in both ears of the rats in each group, and a second distortion product otoacoustic emissions test was used to measure both ears in all of the rats. Boric acid powder was applied to the right middle ear of the rats using tympanic membrane perforation, and the distortion product otoacoustic emissions were measured immediately after the boric acid powder application. The histological changes and distortion product otoacoustic emissions were evaluated three days later in Group A and 40 days later in Group B. RESULTS: No significant differences were found at all of the distortion product otoacoustic emissions frequencies. In Group A, mild inflammation of the middle ear mucosa was found on the third day after boric acid powder application. In Group B, boric acid powder caused mild inflammatory changes on the 40th day, which declined over time. Those changes did not lead to significant fibrosis within the mucosa. CONCLUSION: In rats, boric acid powder causes mild inflammation in middle ear mucosa and it has no ototoxic effects on cochlear outer hair cell function in the inner ear of rats.

Anaphylactic reactions presenting with hypertension.

BACKGROUND: Although a few case reports about hypertensive anaphylaxis (HA) are available in the present literature, there is no study about the prevalence of HA. In this study, we review our cases with anaphylaxis presenting with hypertension and ascertain its prevalence. The documents of the patients who had anaphylactic reactions after the procedures performed for the diagnosis and treatment of allergic diseases in GATA Haydarpasa Clinic of Allergy and Immunology between January 2010 and December 2014 were retrospectively reviewed. Within the study period, 324 patients had undergone 4332 procedures in which 62 of them had developed anaphylaxis. RESULTS: During the procedures, the rate of anaphylaxis was found to be 1.43 %. The rate of HA among the anaphylaxis patients was 12.9 % (8 of 62 patients). During treatments, 2 patients received adrenaline injections without any adverse reaction. CONCLUSIONS: HA may be seen at a considerable rate during an anaphylactic reaction. Anaphylaxis and hypertension can be recovered by adrenaline injection when required. According to the best of our knowledge, this study is the first original study about the prevalence of HA in English-language medical literature.

Facial nerve outcomes after surgery for large vestibular schwannomas: do surgical approach and extent of resection matter?

OBJECT: The object of this study was to evaluate facial nerve outcomes in the surgical treatment of large vestibular schwannomas (VSs; ≥ 2.5 cm maximal or extrameatal cerebellopontine angle diameter) based on both the operative approach and extent of tumor resection. METHODS: A PubMed search was conducted of English language studies on the treatment of large VSs published from 1985 to 2011. Studies were then evaluated and included if they contained data regarding the size of the tumor, surgical approach, extent of resection, and postoperative facial nerve function. RESULTS: Of the 536 studies initially screened, 59 full-text articles were assessed for eligibility, and 30 studies were included for analysis. A total of 1688 tumor resections were reported. Surgical approach was reported in 1390 patients and was significantly associated with facial nerve outcome (ϕ= 0.29, p < 0.0001). Good facial nerve outcomes (House-Brackmann Grade I or II) were produced in 62.5% of the 555 translabyrinthine approaches, 65.2% of the 601 retrosigmoid approaches, and 27.4% of the 234 extended translabyrinthine approaches. Facial nerve outcomes from translabyrinthine and retrosigmoid approaches were not significantly different from each other, but both showed significantly more good facial nerve outcomes, compared with the extended translabyrinthine approach (OR for translabyrinthine vs extended translabyrinthine = 4.43, 95% CI 3.17-6.19, p < 0.0001; OR for retrosigmoid vs extended translabyrinthine = 4.98, 95% CI 3.57-6.95, p < 0.0001). There were 471 patients for whom extent of resection was reported. There was a strong and significant association between degree of resection and outcome (ϕ= 0.38, p < 0.0001). Of the 80 patients receiving subtotal resections, 92.5% had good facial nerve outcomes, compared with 74.6% (n = 55) and 47.3% (n = 336) of those who received near-total resections and gross-total resections, respectively. In the 2-way comparison of good versus suboptimal/poor outcomes (House-Brackmann Grade III-VI), subtotal resection was significantly better than near-total resection (OR = 4.21, 95% CI 1.50-11.79; p = 0.004), and near-total resection was significantly better than gross-total resection (OR = 3.26, 95% CI 1.71-6.20; p = 0.0002) in producing better facial nerve outcomes. CONCLUSIONS: In a pooled patient population from studies evaluating the treatment of large VSs, subtotal and near-total resections were shown to produce better facial nerve outcomes when compared with gross-total resections. The translabyrinthine and retrosigmoid surgical approaches are likely to result in similar rates of good facial nerve outcomes. Both of these approaches show better facial nerve outcomes when compared with the extended translabyrinthine approach, which is typically reserved for especially large tumors. The reported literature on treatment of large VSs is extremely heterogeneous and minimal consistency in reporting outcomes was observed.

Efficacy of topical halofuginone in myringotomy patency.

The objective of the study is to determine whether topical halofuginone (HF) application has an impact on prolonging the time for healing of myringotomy incision, and to investigate histopathologic effects of HF on tympanic membrane (TM) in rat model. Forty rats with normal eardrums were involved in this study. The study group and control group consisted of 30 and 10 rats, respectively. A posterior incision 1 mm in diameter was made on healthy eardrums of the rats. Following incision, gelfoam soaked with HF hydrobromide of 30 mg/dl was applied on the perforation in study group, whereas gelfoam soaked with isotonic saline was applied on the perforation in control group. On days 1, 3, 7, 10, 14, 18, 21, 24, 27, and 30, otoendoscopic evaluation of eardrums under general anesthesia was conducted and perforations were screened. A rat of each group was killed in control days and TMs were dissected to evaluate histopathological changes. The average times for patency of perforation in study and control groups were 21.43 and 7.50 days, respectively. The difference was found to be statistically significant (p < 0.05). Histopathological evaluation revealed that HF reduces hyalinisation and fibrosis in eardrum, when compared with the control group. In conclusion, HF significantly delays closure time of myringotomies in rat model. However, this delay may not be enough for recovery of otitis media with effusion.

Autofluorescence findings in Vogt-Koyanagi-Harada disease.

PURPOSE: To report shortwave autofluorescence (SW-AF) and near infrared autofluorescence (NIR-AF) findings in a case of Vogt-Koyanagi-Harada (VKH) disease. METHODS: A 22-year-old man presented with a 2-week history of headache, moderate hearing loss, discolored hair, and bilateral gradually decreased vision (20/800 bilaterally). Ophthalmologic examinations revealed bilateral granulomatous anterior uveitis and multiple patchy bullous retinal detachments. Fundus fluorescein angiography (FFA), SW-AF, and NIR-AF imaging were performed with a confocal scanning laser ophthalmoscope at the beginning and after resolution. The patient responded well to systemic prednisolone treatment. Visual acuity and hearing loss improved quickly (visual acuity 16/20 bilaterally). RESULTS: Multilobular dye pooling with a dark rim was observed in serous detached retinal areas on late-phase FFA. These areas were observed as hypoAF in SW-AF and NIR-AF mode due to the blockage. After resolution of serous detachment, numerous hypoAF granular dots were observed scattered over the previously serous detached areas in SW-AF and NIR-AF mode. These hypoAF granular dots were seen as window defect lesion in FFA and interpreted as retinal pigment epithelial damage or atrophy. CONCLUSIONS: SW-AF and NIR-AF imaging confirmed granular retinal pigment epithelium atrophy which corresponds to FFA findings. SW-AF and NIR-AF imaging methods are noninvasive and useful techniques for documentation of fundus changes in VKH disease.

Effectiveness of topically applied halofuginone in management of subglottic stenosis in rats.

OBJECTIVE: The aim of the study is to ascertain the antifibrotic effect of topically applied halofuginone after acute subglottic injury. MATERIALS AND METHODS: After standardized trauma to subglottic area, rats were divided into two groups: the study group that received treatment and the control group that did not. The subjects were treated with topical application of cottonoid soaked in 30 mg/dL halofuginone solution for 5 minutes after subglottic trauma. The larynx specimens were examined histopathologically by light microscopy to assess fibrosis, epithelialization, inflammation, and necrosis. RESULTS: The fibrosis indexes of the treated group were significantly less than those of the control group (P < 0.05). CONCLUSIONS: Topically applied halofuginone hydrobromide decreases fibrosis/scar tissue formation secondary to experimentally induced acute subglottic trauma.

Middle ear adenoma with neuroendocrine differentiation (MEA-ND) in the pediatric population.

Middle ear adenoma with neuroendocrine differentiation is an uncommon tumor of the tympanic cavity. The terminology of this entity has suffered due to a poor understanding of the differentiation of these neoplasms, and has included both "adenoma" as well as "carcinoid tumor." Immunohistochemical techniques have helped clarify that these tumors all share elements of neuroendocrine differentiation. Occurrences of this tumor in the pediatric population are extremely rare. In the world literature, only three pediatric cases of middle ear adenoma with neuroendocrine differentiation have been described. We report the youngest case to date of middle ear adenoma with neuroendocrine differentiation, in a 13-year-old boy. We discuss the differential diagnosis, surgical management, and pathology of this entity.

Histologic analysis of the effects of three different support materials within rat middle ear.

OBJECTIVE: To investigate histologic changes in the mucosa of rat middle ear after implantation of three different support materials. STUDY DESIGN: A prospective, controlled animal study. SUBJECTS AND METHODS: Three types of absorbable materials were implanted into the middle ear cavity of rats: (1) Gelfoam (purified gelatin) (Pharmacia & Upjohn Company, New York, NY), (2) Sepragel (viscoelastic gel composed of cross-linked polymers of hyaluronan) (GENZYME Corp, Ridgefield, NJ), and (3) Nasopore (a biodegradable/fragmentable, synthetic polyurethane foam) (Polyganics, Groningen, The Netherlands). Rats were sacrificed after 3 and 20 days to ascertain early and late histologic changes. The bulla of each rat was excised and prepared for microscopic examination. The histologic changes were evaluated by observation of the middle ear cavity and mucosa in terms of polymorphonuclear leucocytes (PMNL), macrophages, giant cells, fibroblasts and other cells, fibrosis, and remnant materials. RESULTS: The histologic appearance of gelfoam-treated middle ears was characterized by more severe acute inflammation in the short-term and prominent fibrosis in the long-term in comparison with sepragel- and nasopore-treated groups. Nasopore appeared to be prone to remnant formation and reorganization by means of fibroblastic activity. CONCLUSION: Compared with gelfoam, both sepragel and nasopore caused less histologic alterations.

Retrograde labeling of the rat facial nerve with carbocyanine dyes to enhance intraoperative identification.

OBJECTIVES: Removal of head and neck neoplasms, especially those of the parotid gland and those of the internal auditory canal and cerebellopontine angle, often requires microdissection of the facial nerve. Displacement or splaying of the nerve can make it difficult to identify facial nerve fibers and/or distinguish them from surrounding tissues. Here we tested a method of labeling the facial nerve with fluorescent lipophilic dyes as a method of providing intraoperative visual confirmation of nerve fibers. METHODS: The facial nerves of adult rats were retrogradely labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI), 3,3'-dioctadecyloxacarbocyanine perchlorate (DiO), or 3,3'-dilinoleyloxacarbocyanine perchlorate (Fast DiO) either by direct application to the nerve sheath or by microinjection into the facial muscles. The nerves were examined 30 days after dye application by means of a dissecting stereomicroscope equipped with epifluorescence filters. RESULTS: Of the dyes tested, Fast DiO proved to be the most effective, providing labeling of the nerve sufficient to be seen with combined fluorescent and bright field stereomicroscopy. Nerve conduction studies indicated that fluorescent labeling did not adversely affect nerve function. CONCLUSIONS: These results raise the possibility of using fluorescent lipophilic dyes to label nerves as a method of enhancing identification and distinguishing nerve fibers during surgery.

[Type I Chiari malformation presenting with isolated unilateral hypoglossal nerve and vocal cord paralysis]. / Izole tek tarafli hipoglossal sinir ve vokal kord paralizisi ile ortaya çikan Chiari tip I malformasyonu.

Chiari malformation refers to caudal displacement of posterior fossa structures through the foramen magnum in the cervical canal and is classified according to the severity of displacement and accompanying cranial nerve and cervical pathologies. We presented a 24-year-old male patient who had isolated unilateral paralysis of the hypoglossal nerve and vagus nerve, with thyroid cartilage asymmetry. Chiari type I malformation was diagnosed by craniospinal magnetic resonance imaging. Suboccipital craniectomy and cervical 1-level large partial laminectomy were performed by the neurosurgery department. No improvement was observed in hypoglossal and vagal paralysis during an 18-month follow-up.

Comparison of paper-patch, fat, and perichondrium myringoplasty in repair of small tympanic membrane perforations.

OBJECTIVE: To compare the effectiveness of paper-patch, fat, and perichondrium myringoplasty in the treatment of chronic tympanic membrane perforations smaller than 3 mm. SUBJECTS AND METHODS: This investigation included 45 patients with chronic tympanic membrane perforations smaller than 3 mm. The patients were equally divided into 3 main groups according to surgical procedures. Each group consisted of 3 subgroups, which had 1-mm, 2-mm, and 3-mm perforations. The patients underwent paper-patch, fat, or perichondrium myringoplasty via transcanal approach under local anesthesia. Healing of perforation, hearing improvement, and complications were investigated. RESULTS: Closure rates of the perforations in the paper-patch, fat, and perichondrium myringoplasty groups were 66.7%, 86.7%, and 86.7%, respectively. There were no statistically significant differences in tympanic membrane closure rates between techniques with regard to size. CONCLUSION: Three techniques were found to be feasible for tympanic membrane perforations smaller than 3 mm.

Effects of halofuginone on fibrosis formation secondary to experimentally induced subglottic trauma.

OBJECTIVE: The aim of the study was to assess the antifibrotic effect of systemically applied halofuginone after subglottic injury. MATERIALS AND METHODS: After standardized trauma to subglottic area, rats were divided into two groups: a study group that received treatment and a control group that did not. The rats were treated with 0.1 mg/kg/day intraperitoneal halofuginone injection for 30 days. The larynx specimens were examined histopathologically under light microscope for epithelization, inflammation, necrosis, and fibrosis. RESULTS: The fibrosis indexes of the treated group were significantly less than those of the control group (P < .01). CONCLUSIONS: Systemically applied halofuginone hydrobromide decreases fibrosis/scar tissue formation secondary to experimentally induced acute subglottic trauma.

Acute otitis media and respiratory viruses.

The present study was performed to elucidate the clinical outcome, and etiology of acute otitis media (AOM) in children based on virologic and bacteriologic tests. The study group consisted of 120 children aged 6 to 144 months with AOM. Middle ear fluid (MEF) was tested for viral pathogens by reverse transcriptase polymerase chain reaction (RT-PCR) and for bacteria by gram-staining and culture. Clinical response was assessed on day 2 to 4, 11 to 13, 26 to 28. Respiratory viruses were isolated in 39 patients (32.5%). Respiratory syncytial virus (RSV) (46.5%) was the most common virus identified in MEF samples, followed by human rhinovirus (HRV) (25.6%), human coronavirus (HCV) (11.6%), influenza (IV) type A (9.3%), adenovirus type sub type A (AV) (4%), and parainfluenza (PIV) type -3 (2%) by RT-PCR. In total 69 bacterial species were isolated from 65 (54.8%) of 120 patients. Streptococcus pneumoniae (S. pneumoniae) was the most frequently isolated bacteria. Viral RNA was detected in 31 (56.3%) of 55 bacteria-negative specimens and in 8 (12.3%) of 65 bacteria-positive MEF samples. No significant differences were found between children representing viral infection alone, combined viral and bacterial infection, bacterial infection alone, and neither viral nor bacterial infection, regarding clinical cure, relapse and reinfection rates. A significantly higher rate of secretory otitis media (SOM) was observed in alone or combined RSV infection with S. pneumonia or Haemophilus influenzae (H. influenzae) than in other viruses infection. Conclusion. This study provides information about etiologic agents and diagnosis of AOM in Turkish children. The findings highlight the importance of common respiratory viruses and bacterial pathogens, particularly RSV, HRV, S. pneumoniae and H. influenzae, in predisposing to and causing AOM in children.

Peripheral osteoma of the mandible mimicking a parotid mass.

We report the case of a peripheral osteoma mimicking a benign tumor in the left parotid gland of a 75-year-old woman. The clinical presentation of the painless mass on the lateral surface of the mandibular ascending ramus was suggestive of a benign parotid tumor such as a pleomorphic adenoma. It was diagnosed using computed tomography (CT) and further delineated using 3D spiral CT scanning. Mandibular osteoma should be considered in differential diagnosis of parotid masses, which can be revealed by conventional radiographs.

Histologic effects of injection snoreplasty and radiofrequency in the rat soft palate.

OBJECTIVE: This study was undertaken to compare the effects of radiofrequency and injection snoreplasty on the histological structure of the soft palate in an animal model. STUDY DESIGN AND SETTING: This is a blinded, controlled histologic evaluation of rat soft palates that underwent separate palatal interventions. Fifty rats were divided into 5 groups of 10 rats (Group 1 = injection snoreplasty [IS], Group 2 = IS + steroid, Group 3 = saline injection, Group 4 = radiofrequency ablation [RFA], and Group 5 = no intervention). The animals were sacrificed after 24 hours, 1 week, 3 weeks, and 5 weeks. Then the soft palates were subjected to histological analysis. RESULTS: Histological analysis demonstrated normal remucosalization in all specimens, with fibrosis increased in Group 1. Interstitial edema was minimal in Group 2. Keratinization was most apparent in Group 4. CONCLUSION: Radiofrequency and injection snoreplasty stiffen the rat soft palate compared with controls.

Juvenile spring eruption: a report of two cases.

Juvenile spring eruption is a photodermatosis characterized by the development of papules and vesicles on the light-exposed helix of the ears after sun exposure, usually in the springtime. It mainly affects boys and young male adults, and has a tendency to occur in the form of small epidemics. We report an outbreak in a group of soldiers who were performing military exercises during cold and sunny weather during a midwinter season. The clinicopathologic features and laboratory test results are described in two of these cases.

Case report: Cochlear implant magnet migration.

A 13-month-old cochlear implant recipient underwent routine device activation. Three months postoperatively, the patient sustained a fall with contact to the area of the implant without immediate complication. Ten months postoperatively, the position of the external coil appeared to have moved and the patient did not seem to be responding as well to sound. Audiological testing could not elicit normal device impedances. AP and lateral plain radiographs of the skull revealed migration of the internal magnet from its position within the internal coil to a position over the receiver/stimulator. This is the first known published case of cochlear implant magnet migration.