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Macrophages
Research Forum—Wednesday
Streptococcus Salivarius and Recurrent Tonsillitis Joao-Flavio Nogueira Jr, MD (presenter); Iulo Barauna, MD; Diego Rodrigo Hermann, MD; Ronaldo Reis Ame´rico, MD; Fernando Oto Balieiro, MD; Shirley Nagata Pignatari, MD; Aldo Eden Cassol Stamm, MD, PhD OBJECTIVES: 1. Investigate the prevalence of Streptococcus salivarius in the oral commensal flora of patients that were divided in two groups: with and without history of recurrent tonsillitis. 2. Compare the prevalence of Streptococcus salivarius in these two grou METHODS: Twenty-five patients of both sexes were enrolled in this study, with ages between 2 and 10 years. The patients
8:00 AM to 11:20 AM RESEARCH FORUM WCC 208AB
䡲
Research Forum: Otology/Neurotology Moderator: Howard W Francis, MD
08:00 Pneumococcal Vaccination and Cochlear Implantation Benjamin P C Wei, MD, PhD (presenter) PROBLEM: There has been an increase in the number of reported cases of cochlear implant-related meningitis since 2002. The most common organism identified was Streptococcus pneumoniae. Previous animal studies have shown that the presence of a cochlear implant in healthy rats reduces the threshold of S. pneumoniae required to induce meningitis for three different routes of infection. The objective is to assess if Pneumovax®23, a 23-valent pneumococcal capsular polysaccharide vaccine, reduces the risk of meningitis in healthy implanted animals using the established quantitaive threshold model. METHODS: Both immunized and unimmunized animals were implanted with a scala tympani electrode array. They were infected with S. pneumoniae via three different routes (hematogenous, middle ear and inner ear) in numbers sufficient to induce meningitis. RESULTS: The implanted rats that received Pneumovax®23 were protected from meningitis when the bacteria were given via the hematogenous and middle ear routes (Fisher’s exact test P⬍0.05). However, the protective effect of the vaccine in the implanted rats was only moderate when the bacteria were inoculated directly into the inner ear.
were divided into 2 groups: children with recurrent tonsillites (Group I) and without recurrent tonsillar infections (Group II). The criteria of recurrent tonsillitis was defined by the current guideline in Brazil. We collected oral swabs in patients of both groups that were later submitted to culture and identification of S. salivarius. The results had statistical analysis. RESULTS: In Group I, with 15 patients, S. salivarius were identified in 0% of cases and non salivarius stains in 100% of the patients. In Group II, with 10 patients, we identified S. salivarius in 62,5% of the cases and non salivarius stains 37,5% of the patients. CONCLUSIONS: Children with recurrent tonsillitis present with minor settling of S. salivarius in the oropharynx compared with children without recurrent tonsillar infections. These data suggest a protective role for S. salivarius against pathogenic bacteria of the oropharynx.
CONCLUSION: The animal model clearly demonstrates that immunization can protect healthy rats with a cochlear implant from meningitis caused by a vaccine-covered serotype. SIGNIFICANCE: This finding supports the notion that all current and future implant recipients should be vaccinated against S. pneumoniae. SUPPORT: The Garnett Passe and Rodney Williams Memorial Foundation Scholarship in Otolaryngology Head and Neck Surgery; The Wagstaff Fellowship, Royal Victorian Eye & Ear Hospital; NIH-NIDCD-N01-DC-3-1005; the Bionic Ear Institute and the Department of Otolaryngology, University of Melbourne; the Australian National Health and Medical Research Council.
08:10 Characterization of Cochlear Microglia/Macrophages Takayuki Nakagawa, MD, PhD (presenter); Takayuki Okano, MD; Juichi Ito, MD, PhD PROBLEM: Recent studies have indicated the substantial role of bone marrow (BM) -derived cells in the cochlear spiral ligament. However, little is yet known about contribution of BM-derived cells to the immune surveillance and the maintenance of homeostasis in the inner ear. This study examines the characteristics and behaviors of microglia/macrophages in the mouse cochlea. METHODS: First, characteristics of BM-derived cells in the mouse inner ear using BM-chimeric mice were studied. In order to visualize BM-derived cells, C57BL/6 mice were lethally irradiated and systemically received hematopoietic stem cells (HSCs) collected from EGFP transgenic mice. Immunohistochemistry was performed to investigate the phenotype of BM-derived cells in the inner ear. Histological study about
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Otolaryngology-Head and Neck Surgery, Vol 137, No 2S, August 2007
cochlear microglia/macrophages was also performed on their morphology and behavior. Then, the dynamics of microglia/ macrophage in inner ears under three pathological conditions were investigated. Alteration in numbers of cochlear microglia/ macrophage was studied following systemic application of M-CSF. As a local surgical stress, animals received injection of physiological saline through the posterior semicircular canal. Change in numbers of microglia/macrophage in the inner ear with age-related degeneration were also studied. RESULTS: BM-derived cells predominantly show microglia/ macrophage phenotype in the cochlear connective tissues and the cochlear peripheral nervous system. A resident population of microglia/macrophages is present within the undamaged cochlea. These cells turn over slowly up to 3 months. The cochlear microglia/macrophages demonstrated dynamic mobilization to the inner ear responding to environmental changes. CONCLUSION: The cochlear microglia/macrophages are continuously supplied from bone marrow and the cochlea responding to stress dynamically gains access to systemic immunity. The cochlear microglia/macrophages may play an important role in initiating response to various stresses. SIGNIFICANCE: These findings should throw a light into inner ear immune disorder including autoimmune hearing impairment, and provide an experimental system with which to explore the mechanisms that control inner ear immunity. SUPPORT: This study was supported by a Grant-in-Aid for Scientific Research (B2, 16390488, 2004-2006, T.N.) from the Ministry of Education, Culture, Sports, Science and Technology of Japan, and in part by a Grant (2005-2006, T.N.) from Takeda Science Foundation and a Grant (2005, T.O.) from the 21st Century COE program of the Ministry of Education, Culture, Sports, Science and Technology of Japan.
08:20 Robotic Cochlear Implant Surgery Using Steerable Electrodes Scott M Rickert, MD (presenter); Spiros Manolidis, MD PROBLEM: Cochlear implantation success is limited by electrode technology and insertion techniques. Current implant electrodes and tools provide very limited force feedback with respect to the delicate basilar membrane. The success of implanted electrodes depends on providing reliable and atraumatic insertion. This pilot study evaluates the potential benefits of using active-bending electrodes to reduce trauma to the cochlea during robot-assisted cochlear implant surgery. METHODS: Novel steerable electrodes have been designed to provide dexterity inside the cochlear for accurate insertion. Using mathematical modeling and path planning, the interaction forces are minimized within the cochlea. These silicone electrodes have programming ability to bend in the shape of a standard human cochlea. A 3-D phantom model of a standard
human cochlea was used for insertion. The insertion force at the tip of the electrode was measured. Experiments were performed with and without steerability and the results were compared. RESULTS: Steerable electrode insertions are repeatable and the best nonsteerable insertion is significantly worse than the worst steerable insertion. A 68% reduction in the insertion force was achieved. Furthermore, the average distance between the cochlear wall and electrode increased significantly in the steerable electrode versus the nonsteerable electrode as the insertion depth increased. CONCLUSION: This study notes the potential of using steerable electrodes to reduce cochlear trauma. It shows a 68% reduction in insertion forces with steerable electrodes. The study correlates the reduction in insertion forces with an increase in the average distance between the electrode and the cochlear wall due to the distal dexterity of the steerable electrodes. SIGNIFICANCE: Robot-assisted cochlear implant surgery can improve the reliability and decrease insertion trauma. It clearly indicates the potential of steerable electrodes to reduce cochlear trauma. Using this novel technique, more atraumatic, reliable insertions in cochlear implant surgery can be achieved.
08:30 Cochlear Rotation and Cochlea Implantation Simon Lloyd (presenter) PROBLEM: The angle of the basal turn of the cochlea relative to the sagittal plane may be important in determining whether cochlear implant (CI) electrode insertion will be straightforward. METHODS: Three paediatric CI cases in which insertion of the implant electrode was difficult are described. The angle of the basal turn relative to the sagittal plane was measured using CT imaging. The angle of the basal turn in children undergoing CI was then prospectively measured using CT imaging. The difficulty of insertion of the electrode was recorded intraoperatively. The basal turn angle in normal adult patients was also assessed. RESULTS: For the initial 3 cases the angles of the basal turn were 71°, 63° and 66° respectively. In the paediatric study population, the mean angles for each ear were not significantly different. The overall mean was 57° (SD 8°). Difficulty with electrode insertion was only encountered in 1 case. The angle was 64° which is similar to the initial 3 implantees. In the adults, the overall mean was 54° (SD 5°). The adult cochleas were significantly more acutely angled than the paediatric cochleas (p⫽0.02). The angles of the cochleas of the 3 patients whose implantations were difficult were significantly more obtuse than those of the normal paediatric population (p⫽0.03). CONCLUSION: The difficulties in inserting the electrodes in the 3 cases described were due to unusually obtuse angles of
Streptococcus Salivarius and Recurrent Tonsillitis Joao-Flavio Nogueira Jr, MD (presenter); Iulo Barauna, MD; Diego Rodrigo Hermann, MD; Ronaldo Reis Ame´rico, MD; Fernando Oto Balieiro, MD; Shirley Nagata Pignatari, MD; Aldo Eden Cassol Stamm, MD, PhD OBJECTIVES: 1. Investigate the prevalence of Streptococcus salivarius in the oral commensal flora of patients that were divided in two groups: with and without history of recurrent tonsillitis. 2. Compare the prevalence of Streptococcus salivarius in these two grou METHODS: Twenty-five patients of both sexes were enrolled in this study, with ages between 2 and 10 years. The patients
8:00 AM to 11:20 AM RESEARCH FORUM WCC 208AB
䡲
Research Forum: Otology/Neurotology Moderator: Howard W Francis, MD
08:00 Pneumococcal Vaccination and Cochlear Implantation Benjamin P C Wei, MD, PhD (presenter) PROBLEM: There has been an increase in the number of reported cases of cochlear implant-related meningitis since 2002. The most common organism identified was Streptococcus pneumoniae. Previous animal studies have shown that the presence of a cochlear implant in healthy rats reduces the threshold of S. pneumoniae required to induce meningitis for three different routes of infection. The objective is to assess if Pneumovax®23, a 23-valent pneumococcal capsular polysaccharide vaccine, reduces the risk of meningitis in healthy implanted animals using the established quantitaive threshold model. METHODS: Both immunized and unimmunized animals were implanted with a scala tympani electrode array. They were infected with S. pneumoniae via three different routes (hematogenous, middle ear and inner ear) in numbers sufficient to induce meningitis. RESULTS: The implanted rats that received Pneumovax®23 were protected from meningitis when the bacteria were given via the hematogenous and middle ear routes (Fisher’s exact test P⬍0.05). However, the protective effect of the vaccine in the implanted rats was only moderate when the bacteria were inoculated directly into the inner ear.
were divided into 2 groups: children with recurrent tonsillites (Group I) and without recurrent tonsillar infections (Group II). The criteria of recurrent tonsillitis was defined by the current guideline in Brazil. We collected oral swabs in patients of both groups that were later submitted to culture and identification of S. salivarius. The results had statistical analysis. RESULTS: In Group I, with 15 patients, S. salivarius were identified in 0% of cases and non salivarius stains in 100% of the patients. In Group II, with 10 patients, we identified S. salivarius in 62,5% of the cases and non salivarius stains 37,5% of the patients. CONCLUSIONS: Children with recurrent tonsillitis present with minor settling of S. salivarius in the oropharynx compared with children without recurrent tonsillar infections. These data suggest a protective role for S. salivarius against pathogenic bacteria of the oropharynx.
CONCLUSION: The animal model clearly demonstrates that immunization can protect healthy rats with a cochlear implant from meningitis caused by a vaccine-covered serotype. SIGNIFICANCE: This finding supports the notion that all current and future implant recipients should be vaccinated against S. pneumoniae. SUPPORT: The Garnett Passe and Rodney Williams Memorial Foundation Scholarship in Otolaryngology Head and Neck Surgery; The Wagstaff Fellowship, Royal Victorian Eye & Ear Hospital; NIH-NIDCD-N01-DC-3-1005; the Bionic Ear Institute and the Department of Otolaryngology, University of Melbourne; the Australian National Health and Medical Research Council.
08:10 Characterization of Cochlear Microglia/Macrophages Takayuki Nakagawa, MD, PhD (presenter); Takayuki Okano, MD; Juichi Ito, MD, PhD PROBLEM: Recent studies have indicated the substantial role of bone marrow (BM) -derived cells in the cochlear spiral ligament. However, little is yet known about contribution of BM-derived cells to the immune surveillance and the maintenance of homeostasis in the inner ear. This study examines the characteristics and behaviors of microglia/macrophages in the mouse cochlea. METHODS: First, characteristics of BM-derived cells in the mouse inner ear using BM-chimeric mice were studied. In order to visualize BM-derived cells, C57BL/6 mice were lethally irradiated and systemically received hematopoietic stem cells (HSCs) collected from EGFP transgenic mice. Immunohistochemistry was performed to investigate the phenotype of BM-derived cells in the inner ear. Histological study about
WEDNESDAY
09:10
P125
P126
Otolaryngology-Head and Neck Surgery, Vol 137, No 2S, August 2007
cochlear microglia/macrophages was also performed on their morphology and behavior. Then, the dynamics of microglia/ macrophage in inner ears under three pathological conditions were investigated. Alteration in numbers of cochlear microglia/ macrophage was studied following systemic application of M-CSF. As a local surgical stress, animals received injection of physiological saline through the posterior semicircular canal. Change in numbers of microglia/macrophage in the inner ear with age-related degeneration were also studied. RESULTS: BM-derived cells predominantly show microglia/ macrophage phenotype in the cochlear connective tissues and the cochlear peripheral nervous system. A resident population of microglia/macrophages is present within the undamaged cochlea. These cells turn over slowly up to 3 months. The cochlear microglia/macrophages demonstrated dynamic mobilization to the inner ear responding to environmental changes. CONCLUSION: The cochlear microglia/macrophages are continuously supplied from bone marrow and the cochlea responding to stress dynamically gains access to systemic immunity. The cochlear microglia/macrophages may play an important role in initiating response to various stresses. SIGNIFICANCE: These findings should throw a light into inner ear immune disorder including autoimmune hearing impairment, and provide an experimental system with which to explore the mechanisms that control inner ear immunity. SUPPORT: This study was supported by a Grant-in-Aid for Scientific Research (B2, 16390488, 2004-2006, T.N.) from the Ministry of Education, Culture, Sports, Science and Technology of Japan, and in part by a Grant (2005-2006, T.N.) from Takeda Science Foundation and a Grant (2005, T.O.) from the 21st Century COE program of the Ministry of Education, Culture, Sports, Science and Technology of Japan.
08:20 Robotic Cochlear Implant Surgery Using Steerable Electrodes Scott M Rickert, MD (presenter); Spiros Manolidis, MD PROBLEM: Cochlear implantation success is limited by electrode technology and insertion techniques. Current implant electrodes and tools provide very limited force feedback with respect to the delicate basilar membrane. The success of implanted electrodes depends on providing reliable and atraumatic insertion. This pilot study evaluates the potential benefits of using active-bending electrodes to reduce trauma to the cochlea during robot-assisted cochlear implant surgery. METHODS: Novel steerable electrodes have been designed to provide dexterity inside the cochlear for accurate insertion. Using mathematical modeling and path planning, the interaction forces are minimized within the cochlea. These silicone electrodes have programming ability to bend in the shape of a standard human cochlea. A 3-D phantom model of a standard
human cochlea was used for insertion. The insertion force at the tip of the electrode was measured. Experiments were performed with and without steerability and the results were compared. RESULTS: Steerable electrode insertions are repeatable and the best nonsteerable insertion is significantly worse than the worst steerable insertion. A 68% reduction in the insertion force was achieved. Furthermore, the average distance between the cochlear wall and electrode increased significantly in the steerable electrode versus the nonsteerable electrode as the insertion depth increased. CONCLUSION: This study notes the potential of using steerable electrodes to reduce cochlear trauma. It shows a 68% reduction in insertion forces with steerable electrodes. The study correlates the reduction in insertion forces with an increase in the average distance between the electrode and the cochlear wall due to the distal dexterity of the steerable electrodes. SIGNIFICANCE: Robot-assisted cochlear implant surgery can improve the reliability and decrease insertion trauma. It clearly indicates the potential of steerable electrodes to reduce cochlear trauma. Using this novel technique, more atraumatic, reliable insertions in cochlear implant surgery can be achieved.
08:30 Cochlear Rotation and Cochlea Implantation Simon Lloyd (presenter) PROBLEM: The angle of the basal turn of the cochlea relative to the sagittal plane may be important in determining whether cochlear implant (CI) electrode insertion will be straightforward. METHODS: Three paediatric CI cases in which insertion of the implant electrode was difficult are described. The angle of the basal turn relative to the sagittal plane was measured using CT imaging. The angle of the basal turn in children undergoing CI was then prospectively measured using CT imaging. The difficulty of insertion of the electrode was recorded intraoperatively. The basal turn angle in normal adult patients was also assessed. RESULTS: For the initial 3 cases the angles of the basal turn were 71°, 63° and 66° respectively. In the paediatric study population, the mean angles for each ear were not significantly different. The overall mean was 57° (SD 8°). Difficulty with electrode insertion was only encountered in 1 case. The angle was 64° which is similar to the initial 3 implantees. In the adults, the overall mean was 54° (SD 5°). The adult cochleas were significantly more acutely angled than the paediatric cochleas (p⫽0.02). The angles of the cochleas of the 3 patients whose implantations were difficult were significantly more obtuse than those of the normal paediatric population (p⫽0.03). CONCLUSION: The difficulties in inserting the electrodes in the 3 cases described were due to unusually obtuse angles of