The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Samuel Early - One of the best experts on this subject based on the ideXlab platform.
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initial method for characterization of tympanic membrane drug permeability in human temporal bones in situ
Frontiers in Neurology, 2021Co-Authors: Samuel Early, Rong Yang, Zipei Zhang, Jens C Van Der Valk, Daniel S KohaneAbstract:Background & introduction: Acute otitis media is the most common reason for a visit to the pediatrician, often requiring systemic administration of oral antibiotics. Local drug therapy applied to the middle ear could avoid side effects associated with systemic administration of antibiotics, however in the majority of patients this would require drugs to diffuse across an intact tympanic membrane. Experimental methods for testing trans-tympanic drug diffusion in human tissues in situ would be highly valuable to guide drug therapy development for local drug delivery to the middle ear. Materials & methods: A total of 30 cadaveric human temporal bones were characterized by trans-tympanic impedance testing to determine how steps in tissue processing and storage might impact intactness of the tympanic membrane and thus suitability for use in trans-tympanic drug diffusion studies. Ciprofloxacin drug solutions of varying concentrations were then applied to the lateral surface of the tympanic membrane in eight samples, and middle ear aspirate was collected over the following 48 hours to evaluate trans-tympanic diffusion to the middle ear. Results: Tissue processing steps that involved extensive tissue manipulation were consistently associated with evidence of microperforations in the tympanic membrane tissue. Maintaining the tympanic membrane in situ within the temporal bone, while using an otologic drill to obtain transmastoid access to the middle ear, was demonstrated as a reliable, non-damaging technique for accessing both lateral and medial surfaces for trans-tympanic diffusion testing. Diffusion testing in these bones demonstrated trans-tympanic diffusion of ciprofloxacin when administered at sufficiently high concentration. Discussion & conclusion: The study describes key techniques and best practices, as well as pitfalls to avoid, in the development of a model for studying trans-tympanic drug diffusion in human temporal bones in situ. This model can be a valuable research tool in advancing progress towards eventual clinical studies for trans-tympanic drug delivery to the middle ear.
Tatsuo Nakamura - One of the best experts on this subject based on the ideXlab platform.
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Regeneration of the Nerves in the Aerial Cavity with an Artificial Nerve Conduit-Reconstruction of Chorda Tympani Nerve Gaps-
2016Co-Authors: Toshiaki Yamanaka, Hiroshi Hosoi, Takayuki Murai, Takehiko Kobayashi, Yuji Inada, Tatsuo NakamuraAbstract:Objectives/Hypothesis: Due to its anatomical features, the chorda tympani nerve (CTN) is sometimes sacrificed during middle ear surgery, resulting in taste dysfunction. We examined the effect of placing an artificial nerve conduit, a polyglycolic acid (PGA)-collagen tube, across the gap in the section of the resected chorda tympani nerve (CTN) running through the tympanic cavity. Methods: The CTN was reconstructed with a PGA-collagen tube in three patients with taste disturbance who underwent CTN resection. To evaluate the effect of the reconstruction procedure on the patients ’ gustatory function, we measured the patients ’ electrogustometry (EGM) thresholds. The patients were followed-up for at least two years. Results: Gustatory function was completely restored in all of the patients after the reconstruction. The patients ’ EGM thresholds exhibited early improvements within one to two weeks and had returned to their normal ranges within three months. They subsequently remained stable throughout the two-year follow-up period. In a patient who underwent a second surgical procedure, it was found that the PGA-collagen tube used in the first surgical procedure had been absorbed and replaced by new CTN fibers with blood vessels on their surfaces. Conclusion: These results suggest that reconstruction of the CTN with an artificial nerve conduit, a PGA-collagen tube, allows functional and morphological regeneration of the nerve and facilitates the recovery of taste function. PGA-collage
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regeneration of the nerves in the aerial cavity with an artificial nerve conduit reconstruction of chorda tympani nerve gaps
PLOS ONE, 2014Co-Authors: Toshiaki Yamanaka, Hiroshi Hosoi, Takayuki Murai, Takehiko Kobayashi, Yuji Inada, Tatsuo NakamuraAbstract:Objectives/Hypothesis Due to its anatomical features, the chorda tympani nerve (CTN) is sometimes sacrificed during middle ear surgery, resulting in taste dysfunction. We examined the effect of placing an artificial nerve conduit, a polyglycolic acid (PGA)-collagen tube, across the gap in the section of the resected chorda tympani nerve (CTN) running through the tympanic cavity. Methods The CTN was reconstructed with a PGA-collagen tube in three patients with taste disturbance who underwent CTN resection. To evaluate the effect of the reconstruction procedure on the patients' gustatory function, we measured the patients' electrogustometry (EGM) thresholds. The patients were followed-up for at least two years. Results Gustatory function was completely restored in all of the patients after the reconstruction. The patients' EGM thresholds exhibited early improvements within one to two weeks and had returned to their normal ranges within three months. They subsequently remained stable throughout the two-year follow-up period. In a patient who underwent a second surgical procedure, it was found that the PGA-collagen tube used in the first surgical procedure had been absorbed and replaced by new CTN fibers with blood vessels on their surfaces. Conclusion These results suggest that reconstruction of the CTN with an artificial nerve conduit, a PGA-collagen tube, allows functional and morphological regeneration of the nerve and facilitates the recovery of taste function. PGA-collagen tubes might be useful for repairing CTNs that are resected during middle ear surgery. Further research is required to confirm these preliminary results although this is the first report to describe the successful regeneration of a nerve running through an aerial space.
Jens C Van Der Valk - One of the best experts on this subject based on the ideXlab platform.
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initial method for characterization of tympanic membrane drug permeability in human temporal bones in situ
Frontiers in Neurology, 2021Co-Authors: Samuel Early, Rong Yang, Zipei Zhang, Jens C Van Der Valk, Daniel S KohaneAbstract:Background & introduction: Acute otitis media is the most common reason for a visit to the pediatrician, often requiring systemic administration of oral antibiotics. Local drug therapy applied to the middle ear could avoid side effects associated with systemic administration of antibiotics, however in the majority of patients this would require drugs to diffuse across an intact tympanic membrane. Experimental methods for testing trans-tympanic drug diffusion in human tissues in situ would be highly valuable to guide drug therapy development for local drug delivery to the middle ear. Materials & methods: A total of 30 cadaveric human temporal bones were characterized by trans-tympanic impedance testing to determine how steps in tissue processing and storage might impact intactness of the tympanic membrane and thus suitability for use in trans-tympanic drug diffusion studies. Ciprofloxacin drug solutions of varying concentrations were then applied to the lateral surface of the tympanic membrane in eight samples, and middle ear aspirate was collected over the following 48 hours to evaluate trans-tympanic diffusion to the middle ear. Results: Tissue processing steps that involved extensive tissue manipulation were consistently associated with evidence of microperforations in the tympanic membrane tissue. Maintaining the tympanic membrane in situ within the temporal bone, while using an otologic drill to obtain transmastoid access to the middle ear, was demonstrated as a reliable, non-damaging technique for accessing both lateral and medial surfaces for trans-tympanic diffusion testing. Diffusion testing in these bones demonstrated trans-tympanic diffusion of ciprofloxacin when administered at sufficiently high concentration. Discussion & conclusion: The study describes key techniques and best practices, as well as pitfalls to avoid, in the development of a model for studying trans-tympanic drug diffusion in human temporal bones in situ. This model can be a valuable research tool in advancing progress towards eventual clinical studies for trans-tympanic drug delivery to the middle ear.
Peter Hegyi - One of the best experts on this subject based on the ideXlab platform.
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endoscopic versus microscopic stapes surgery outcomes a meta analysis and systematic review
Laryngoscope, 2020Co-Authors: Alexandros Koukkoullis, Istvan Toth, Noemi Gede, Zsolt Szakacs, Peter Hegyi, Gabor Varga, Istvan Pap, Kinga HarmatAbstract:OBJECTIVE Compare intraoperative and postoperative outcomes of endoscopic and microscopic stapes surgery to provide objective evidence on whether the former is a better alternative than the latter. METHODS We performed a systematic review and meta-analysis for studies that compared endoscopic stapes surgery with microscopic stapes surgery. Only studies that met predetermined criteria were selected and assessed for bias and quality. Primary outcomes were postoperative air-bone gap (ABG) and chorda tympani nerve injury. Secondary outcomes were average operating time, tympanic membrane (TM) perforation, and postoperative taste disturbance, pain, and dizziness. We calculated pooled odds ratios (ORs) with 95% confidence intervals (CIs) for dichotomous outcomes and weighted mean difference (WMD) with 95% CI for continuous outcomes. A confidence interval starting above 1.0 was considered as statistically significant. I2 and χ2 tests were used to quantify statistical heterogeneity. We used funnel plots to look for publication bias and performed a sensitivity analysis. RESULTS Six nonrandomized cohort studies were eligible. The primary outcomes were ABG 20 dB: OR = 2.51 (95% CI: 0.77 to 8.22), and chorda tympani injury: OR = 3.51 (95% CI: 1.55 to 7.93). Secondary outcomes were taste: OR = 2.36 (95% CI: 1.01 to 5.51), average operation time: WMD = 0.14 (95% CI: -11.69 to 11.98), TM perforation: OR = 1.70 (95% CI: 0.44 to 6.58); pain: OR = 0.84 (95% CI: 0.36 to 1.96), and dizziness: OR = 2.15 (95% CI: 0.94 to 4.89). CONCLUSIONS Endoscopic stapes surgery is a valid alternative to the microscope. LEVEL OF EVIDENCE 2a Laryngoscope, 130: 2019-2027, 2020.
Toshiaki Yamanaka - One of the best experts on this subject based on the ideXlab platform.
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Regeneration of the Nerves in the Aerial Cavity with an Artificial Nerve Conduit-Reconstruction of Chorda Tympani Nerve Gaps-
2016Co-Authors: Toshiaki Yamanaka, Hiroshi Hosoi, Takayuki Murai, Takehiko Kobayashi, Yuji Inada, Tatsuo NakamuraAbstract:Objectives/Hypothesis: Due to its anatomical features, the chorda tympani nerve (CTN) is sometimes sacrificed during middle ear surgery, resulting in taste dysfunction. We examined the effect of placing an artificial nerve conduit, a polyglycolic acid (PGA)-collagen tube, across the gap in the section of the resected chorda tympani nerve (CTN) running through the tympanic cavity. Methods: The CTN was reconstructed with a PGA-collagen tube in three patients with taste disturbance who underwent CTN resection. To evaluate the effect of the reconstruction procedure on the patients ’ gustatory function, we measured the patients ’ electrogustometry (EGM) thresholds. The patients were followed-up for at least two years. Results: Gustatory function was completely restored in all of the patients after the reconstruction. The patients ’ EGM thresholds exhibited early improvements within one to two weeks and had returned to their normal ranges within three months. They subsequently remained stable throughout the two-year follow-up period. In a patient who underwent a second surgical procedure, it was found that the PGA-collagen tube used in the first surgical procedure had been absorbed and replaced by new CTN fibers with blood vessels on their surfaces. Conclusion: These results suggest that reconstruction of the CTN with an artificial nerve conduit, a PGA-collagen tube, allows functional and morphological regeneration of the nerve and facilitates the recovery of taste function. PGA-collage
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regeneration of the nerves in the aerial cavity with an artificial nerve conduit reconstruction of chorda tympani nerve gaps
PLOS ONE, 2014Co-Authors: Toshiaki Yamanaka, Hiroshi Hosoi, Takayuki Murai, Takehiko Kobayashi, Yuji Inada, Tatsuo NakamuraAbstract:Objectives/Hypothesis Due to its anatomical features, the chorda tympani nerve (CTN) is sometimes sacrificed during middle ear surgery, resulting in taste dysfunction. We examined the effect of placing an artificial nerve conduit, a polyglycolic acid (PGA)-collagen tube, across the gap in the section of the resected chorda tympani nerve (CTN) running through the tympanic cavity. Methods The CTN was reconstructed with a PGA-collagen tube in three patients with taste disturbance who underwent CTN resection. To evaluate the effect of the reconstruction procedure on the patients' gustatory function, we measured the patients' electrogustometry (EGM) thresholds. The patients were followed-up for at least two years. Results Gustatory function was completely restored in all of the patients after the reconstruction. The patients' EGM thresholds exhibited early improvements within one to two weeks and had returned to their normal ranges within three months. They subsequently remained stable throughout the two-year follow-up period. In a patient who underwent a second surgical procedure, it was found that the PGA-collagen tube used in the first surgical procedure had been absorbed and replaced by new CTN fibers with blood vessels on their surfaces. Conclusion These results suggest that reconstruction of the CTN with an artificial nerve conduit, a PGA-collagen tube, allows functional and morphological regeneration of the nerve and facilitates the recovery of taste function. PGA-collagen tubes might be useful for repairing CTNs that are resected during middle ear surgery. Further research is required to confirm these preliminary results although this is the first report to describe the successful regeneration of a nerve running through an aerial space.
