Role of Facial Nerve Reconstruction With Anastomosis and Polyglycolic Acid Tube in Accelerating Functional Recovery After Axotomy in the Rat Facial Nucleus.

Facial nerve injuries stem from trauma or tumor surgery, triggering neurodegeneration and neuronal cell death in the facial nucleus, consequently inducing irreversible nerve paralysis. Following facial nerve transection, glial cells are activated and undergo proliferation, facilitating motor neuron survival, repair, and regeneration. Clinical approaches, including nerve anastomosis and hypoglossal nerve grafting, require delicate microscopic techniques. Recent advancements involve nerve reconstruction using polyglycolic acid (PGA) tubes, which yield nerve function improvement. However, the central pathophysiological effects of these procedures remain unclear. Therefore, using PGA tubes, we evaluated neurodegeneration and microglial inflammatory response in rats after facial nerve transection. Facial nerve functions were evaluated using vibrissae and blink reflex scores. In the end-to-end anastomosis and PGA tube reconstruction groups, a partial improvement in facial motor function was observed, with increased nerve fiber survival in the former. Approximately 90% of neurons survived in both groups, wherein gliosis exhibited increased microglial activation compared to that in the transection group. These results indicate that PGA tube-assisted nerve reconstruction post-facial nerve transection, although inferior to end-to-end anastomosis, improved certain functions and prevented neuronal cell death. Furthermore, the prolonged inflammatory response in the facial nerve nucleus underscored the correlation between neuronal function and survival and microglia.

Performance of GPT-4V in Answering the Japanese Otolaryngology Board Certification Examination Questions: Evaluation Study.

BACKGROUND: Artificial intelligence models can learn from medical literature and clinical cases and generate answers that rival human experts. However, challenges remain in the analysis of complex data containing images and diagrams. OBJECTIVE: This study aims to assess the answering capabilities and accuracy of ChatGPT-4 Vision (GPT-4V) for a set of 100 questions, including image-based questions, from the 2023 otolaryngology board certification examination. METHODS: Answers to 100 questions from the 2023 otolaryngology board certification examination, including image-based questions, were generated using GPT-4V. The accuracy rate was evaluated using different prompts, and the presence of images, clinical area of the questions, and variations in the answer content were examined. RESULTS: The accuracy rate for text-only input was, on average, 24.7% but improved to 47.3% with the addition of English translation and prompts (P<.001). The average nonresponse rate for text-only input was 46.3%; this decreased to 2.7% with the addition of English translation and prompts (P<.001). The accuracy rate was lower for image-based questions than for text-only questions across all types of input, with a relatively high nonresponse rate. General questions and questions from the fields of head and neck allergies and nasal allergies had relatively high accuracy rates, which increased with the addition of translation and prompts. In terms of content, questions related to anatomy had the highest accuracy rate. For all content types, the addition of translation and prompts increased the accuracy rate. As for the performance based on image-based questions, the average of correct answer rate with text-only input was 30.4%, and that with text-plus-image input was 41.3% (P=.02). CONCLUSIONS: Examination of artificial intelligence's answering capabilities for the otolaryngology board certification examination improves our understanding of its potential and limitations in this field. Although the improvement was noted with the addition of translation and prompts, the accuracy rate for image-based questions was lower than that for text-based questions, suggesting room for improvement in GPT-4V at this stage. Furthermore, text-plus-image input answers a higher rate in image-based questions. Our findings imply the usefulness and potential of GPT-4V in medicine; however, future consideration of safe use methods is needed.

Macrophage depletion attenuates degeneration of spiral ganglion neurons in kanamycin-induced unilateral hearing loss model.

Pathological conditions in cochlea, such as ototoxicity, acoustic trauma, and age-related cochlear degeneration, induce cell death in the organ of Corti and degeneration of the spiral ganglion neurons (SGNs). Although macrophages play an essential role after cochlear injury, its role in the SGNs is limitedly understood. We analyzed the status of macrophage activation and neuronal damage in the spiral ganglion after kanamycin-induced unilateral hearing loss in mice. The number of ionized calcium-binding adapter molecule 1 (Iba1)-positive macrophages increased 3 days after unilateral kanamycin injection. Macrophages showed larger cell bodies, suggesting activation status. Interestingly, the number of activating transcription factor 3 (ATF3)-positive-neurons, an indicator of early neuronal damage, also increased at the same timing. In the later stages, the number of macrophages decreased, and the cell bodies became smaller, although the number of neuronal deaths increased. To understand their role in neuronal damage, macrophages were depleted via intraperitoneal injection of clodronate liposome 24 h after kanamycin injection. Macrophage depletion decreased the number of ATF3-positive neurons at day 3 and neuronal death at day 28 in the spiral ganglion following kanamycin injection. Our results suggest that suppression of inflammation by clodronate at early timing can protect spiral ganglion damage following cochlear insult.

Enhanced Cochlear Transduction by AAV9 with High-Concentration Sucrose.

The inner ear is a primary lesion in sensorineural hearing loss and has been a target in gene therapy. The efficacy of gene therapy depends on achieving sufficient levels of transduction at a safe vector dose. Vectors derived from various adeno-associated viruses (AAVs) are predominantly used to deliver therapeutic genes to inner ear cells. AAV9 and its variants vector are attractive candidates for clinical applications since they can cross the mesothelial cell layer and transduce inner hair cells (IHCs), although this requires relatively high doses. In this study, we investigated the effects of sucrose on the transduction of a variant of the AAV9 vector for gene transfer in the inner ear. We found that high concentrations of sucrose increased gene transduction in House Ear Institute-Organ of Corti 1 (HEI-OC1) cells in vitro. In addition, we demonstrated that simultaneous administration of sucrose enhanced the transduction of mouse IHCs and spiral ligament cells using an AAV9 variant vector. The procedure did not increase the thresholds in the auditory brainstem response, suggesting that sucrose had no adverse effect on auditory function. This versatile method may be valuable in the development of novel gene therapies for adult-onset sensorineural hearing loss.

Efficacy of endoscopic powered intracapsular tonsillectomy and adenoidectomy for pediatric obstructive sleep apnea: A retrospective case-control study.

OBJECTIVE: Safe surgery for pediatric patients with obstructive sleep apnea (OSA) is important to decrease postoperative events and improve cost-effectiveness. Therefore, this study aimed to compare surgical efficacy and safety between powered intracapsular tonsillectomy and adenoidectomy (PITA) and extracapsular tonsillectomy and adenoidectomy for OSA in children. METHODS: In this retrospective case-control study, patient characteristics and postoperative outcomes were compared between 93 children with OSA who underwent PITA and 81 children who underwent conventional extracapsular tonsillectomy and adenoidectomy at a tertiary hospital. Data analysis using multivariate, multiple regression, and binomial logistic regression analyses was performed. RESULTS: PITA reduced the odds of postoperative hemorrhage by 8.95% (odds ratio [OR]: 5.69, p = 0.013) and of secondary hemorrhage by 8.8% (OR: 10.08, p = 0.006), decreased postoperative analgesia use by 0.35% (p < 0.001), and increased oral intake on postoperative day 1 by 17% (p < 0.001). There were no significant differences in early hemorrhage or regrowth rates between the groups. CONCLUSION: PITA could reduce the risk of secondary hemorrhage and improve postoperative quality of life, which are ideal clinical benefits of surgery in pediatric patients with OSA.