The impact of multidisciplinary approaches on the outcomes of olfactory neuroblastoma treated with postoperative radiotherapy

BACKGROUND

We investigated the outcomes of postoperative radiation therapy for olfactory neuroblastoma (ONB) and our cross-departmental collaboration to enhance the effectiveness of cancer treatment.

METHODS

We retrospectively evaluated 22 patients with ONB who underwent postoperative radiotherapy after tumor resection. En bloc resection was performed; pathology specimens were prepared in coronal sections; and irradiation fields were determined after discussion with radiation oncologists, head and neck surgeons, and pathologists.

RESULTS

The overall survival and local control rates were 95.5% and 100%, respectively, at a median 37-month follow-up. The 3- and 5-year disease-free survival (DFS) rates were 64.4% and 56.3%, respectively. Of the 22 patients, 9 (8 Kadish C and 1 Kadish B) had disease recurrence. Of the nine patients, five had positive margins and two had closed margins; cervical lymph node recurrence occurred in six, and distant metastasis with or without cervical lymph node recurrence occurred in three. DFS analysis of risk factors showed no statistically significant differences, but positive margins were a significant recurrence factor in multivariate analysis.

CONCLUSIONS

The local control rate of ONB treated with postoperative radiation therapy was 100%. This may be attributed to cross-departmental cooperation between head and neck surgeons, pathologists, and radiation oncologists, which resulted in accurate matching of CT images for treatment planning with the location of the tumor and positive margins. Longer follow-up periods are required to evaluate the effectiveness of our strategy.

Effect of basic fibroblast growth factor with collagen/gelatin fixture in a rabbit model of nasal septum perforation

Introduction

The treatment of nasal septum perforation solely by surgical intervention presents significant challenges. This study evaluated the effect of basic fibroblast growth factor (bFGF) in combination with collagen/gelatin on wound healing of nasal septum perforation in a rabbit animal model.

Methods

A nasal septum perforation rabbit model was created. bFGF was added to a collagen/gelatin fixture and placed adjacent to the perforation, which is a complete defect. The rabbits were divided into three groups: the sham group that underwent the surgical procedure only, bFGF (-) group that received collagen/gelatin fixture without bFGF, and bFGF(+) group that received collagen/gelatin fixture with bFGF. The dimensions of the perforations were measured after 4 weeks, and the septum was subjected to histological examination.

Results

All perforations remained open in the sham group (closure rate: 20.4%-83.1%). The closure rates of the bFGF(-) and bFGF(+) groups were 49.4%-68.8% and 72.7%-100%, respectively. No significant difference was noted in the closure rates between the sham and bFGF(-) groups; however, significant differences were observed between the sham and bFGF(+) groups, and the bFGF(-) and bFGF(+) groups (p < 0.05), indicating that bFGF promoted perforation closure.

Conclusions

The study demonstrated that bFGF with collagen/gelatin carrier promoted wound healing in a rabbit model of nasal septum perforation.

Evidence of a Hardening in the Cosmic Ray Proton Spectrum at around 166 TeV Observed by the GRAPES-3 Experiment

We present the measurement of the cosmic ray proton spectrum from 50 TeV to 1.3 PeV using 7.81×10^{6} extensive air shower events recorded by the ground-based GRAPES-3 experiment between 1 January 2014 and 26 October 2015 with a live time of 460 day. Our measurements provide an overlap with direct observations by satellite and balloon-based experiments. The electromagnetic and muon components in the shower were measured by a dense array of plastic scintillator detectors and a tracking muon telescope, respectively. The relative composition of the proton primary from the air shower data containing all primary particles was extracted using the multiplicity distribution of muons which is a sensitive observable for mass composition. The observed proton spectrum suggests a spectral hardening at ∼166  TeV and disfavors a single power law description of the spectrum up to the Knee energy (∼3  PeV).

Loss of Pax3 causes reduction of melanocytes in the developing mouse cochlea

Cochlear melanocytes are intermediate cells in the stria vascularis that generate endocochlear potentials required for auditory function. Human PAX3 mutations cause Waardenburg syndrome and abnormalities of skin and retinal melanocytes, manifested as congenital hearing loss (~ 70%) and hypopigmentation of skin, hair and eyes. However, the underlying mechanism of hearing loss remains unclear. Cochlear melanocytes in the stria vascularis originated from Pax3-traced melanoblasts and Plp1-traced Schwann cell precursors, both of which derive from neural crest cells. Here, using a Pax3-Cre knock-in mouse that allows lineage tracing of Pax3-expressing cells and disruption of Pax3, we found that Pax3 deficiency causes foreshortened cochlea, malformed vestibular apparatus, and neural tube defects. Lineage tracing and in situ hybridization show that Pax3+ derivatives contribute to S100+, Kir4.1+ and Dct+ melanocytes (intermediate cells) in the developing stria vascularis, all of which are significantly diminished in Pax3 mutant animals. Taken together, these results suggest that Pax3 is required for the development of neural crest cell-derived cochlear melanocytes, whose absence may contribute to congenital hearing loss of Waardenburg syndrome in humans.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Granular flow experiment using artificial gravity generator at International Space Station

Studying the gravity-dependent characteristics of regolith, fine-grained granular media covering extra-terrestrial bodies is essential for the reliable design and analysis of landers and rovers for space exploration. In this study, we propose an experimental approach to examine a granular flow under stable artificial gravity conditions for a long duration generated by a centrifuge at the International Space Station. We also perform a discrete element simulation of the granular flow in both artificial and natural gravity environments. The simulation results verify that the granular flows in artificial and natural gravity are consistent. Further, regression analysis of the experimental results reveals that the mass flow rate of granular flow quantitatively follows a well-known physics-based law with some deviations under low-gravity conditions, implying that the bulk density of the granular media decreases with gravity. This insight also indicates that the bulk density considered in simulation studies of space probes under low-gravity conditions needs to be tuned for their reliable design and analysis.

Preoperative prediction of sinonasal papilloma by artificial intelligence using nasal video endoscopy: a retrospective study

Sinonasal inverted papilloma (IP) is at risk of recurrence and malignancy, and early diagnosis using nasal endoscopy is essential. We thus developed a diagnostic system using artificial intelligence (AI) to identify nasal sinus papilloma. Endoscopic surgery videos of 53 patients undergoing endoscopic sinus surgery were edited to train and evaluate deep neural network models and then a diagnostic system was developed. The correct diagnosis rate based on visual examination by otolaryngologists was also evaluated using the same videos and compared with that of the AI diagnostic system patients. Main outcomes evaluated included the percentage of correct diagnoses compared to AI diagnosis and the correct diagnosis rate for otolaryngologists based on years of practice experience. The diagnostic system had an area under the curve of 0.874, accuracy of 0.843, false positive rate of 0.124, and false negative rate of 0.191. The average correct diagnosis rate among otolaryngologists was 69.4%, indicating that the AI was highly accurate. Evidently, although the number of cases was small, a highly accurate diagnostic system was created. Future studies with larger samples to improve the accuracy of the system and expand the range of diseases that can be detected for more clinical applications are warranted.

Time Analysis of Recidivism in Acquired Cholesteatoma Using the Kaplan-Meier Method

OBJECTIVE

To analyze the time trends of recidivism of acquired cholesteatoma using the Kaplan-Meier method.

STUDY DESIGN

We conducted a retrospective, observational study of 256 patients having their first cholesteatoma surgery. The cumulative recidivism-free rate was calculated using Kaplan-Meier survival analysis related to the follow-up period, pathophysiology, the extent of the disease, and recidivism pathologies.

RESULTS

Pars flacida cholesteatoma with tympanic cavity progression had a high likelihood of recurrence disease. Pars tensa cholesteatoma led to more recurrence of the disease than the residual disease. In both pars flacida and pars tensa cholesteatoma, the incidence of disease recurrence increased even 3 years after surgery. On the contrary, the incidence of residual disease peaked within 3 years after surgery, and thereafter, the incidence of residual disease tended to be small. In particular, pars flacida cholesteatoma extending into the mastoid cavity or tympanic cavity tended to recur up to 5 years postoperatively.

CONCLUSIONS

We calculated the cumulative recidivism-free rates of 256 patients with cholesteatoma using Kaplan-Meier survival analysis. These results can lead to better estimates of the length of the follow-up period.

LEVEL OF EVIDENCE

Level IV evidence from case-control studies.

Pax3 deficiency diminishes melanocytes in the developing mouse cochlea

Cochlear melanocytes are intermediate cells in the stria vascularis that generate endocochlear potentials required for auditory function. Human PAX3 mutations cause Waardenburg syndrome and abnormalities of melanocytes, manifested as congenital hearing loss and hypopigmentation of skin, hair and eyes. However, the underlying mechanism of hearing loss remains unclear. During development, cochlear melanocytes in the stria vascularis are dually derived from Pax3-Cre+ melanoblasts migrating from neuroepithelial cells including neural crest cells and Plp1+ Schwann cell precursors originated from also neural crest cells, differentiating in a basal-apical manner. Here, using a Pax3-Cre mouse line, we found that Pax3 deficiency causes foreshortened cochlea, malformed vestibular apparatus, and neural tube defects. Lineage tracing and in situ hybridization show that Pax3-Cre derivatives contribute to S100+ , Kir4.1+ and Dct+ melanocytes (intermediate cells) in the developing stria vascularis, all significantly diminished in Pax3 mutant animals. Taken together, these results suggest that Pax3 is required for the development of neural crest cell-derived cochlear melanocytes, whose absence may contribute to congenital hearing loss of Waardenburg syndrome in human.

Imaging analysis of dural exposure in cholesteatomas with a skull base defect

PURPOSE

Dural exposure during cholesteatoma surgery can pose a risk of cerebrospinal fluid leakage or residual disease. Therefore, delicate handling of the area surrounding the bone defect in the cranial fossa is required. However, in small-sized defects, preoperative prediction of dural exposure can be challenging. This study aimed to evaluate the diagnostic value of computed tomography (CT) for preoperative prediction of cholesteatoma-related dural exposure in bone discontinuities in the skull base.

METHODS

We evaluated serial high-resolution CT images showing bone density discontinuities in the middle cranial fossa (MCF) requiring mastoidectomy for cholesteatoma. The CT and intraoperative findings were analyzed retrospectively. We evaluated the length between the superior margins of the bone density discontinuities using coronal CT planes. Receiver operating characteristic (ROC) curves were constructed to determine the optimal cut-off values.

RESULTS

We extracted data from 107 bone density discontinuities, among which 54 (50.5%) showed dural exposure intraoperatively. Discontinuities with dural exposure (n = 54) had significantly greater lengths than did those without (n = 53) (p < 0.001, Wilcoxon rank-sum test). The area under the curve was 0.9780 according to the ROC analysis, and the optimal cut-off value was determined to be 2.99 mm (sensitivity 92.59%; specificity 94.34%).

CONCLUSION

A bone density discontinuity length of > 2.99 mm in the MCF on coronal CT plane is a reliable diagnostic marker for cholesteatoma-related dural exposure. Thus, preoperative high-resolution CT analysis can inform optimal surgical preparation and planning before manipulating the area surrounding the osteolytic lesion in the MCF.

Epigenetic Regulation as a New Therapeutic Target for Middle Ear Cholesteatoma

HYPOTHESIS

To evaluate the effectiveness of the menin-MLL inhibitor, MI503, as a conservative treatment of middle ear cholesteatoma (cholesteatoma) in a mouse model and to confirm its safety profile regarding auditory function in vivo.

BACKGROUND

Cholesteatoma is a mass formed by the keratinizing squamous epithelium in the tympanic cavity and/or mastoid and subepithelial connective tissue and by the progressive accumulation of keratin debris with/without a surrounding inflammatory reaction. Although the main treatment is surgical therapy, the techniques to prevent recurrence remain a critical area of research. Recently, the use of MI503 in experiments resulted in the inhibition of the growth of cholesteatoma in vivo under histone modification.

METHODS

After cholesteatoma was induced in ICR mice (n = 7) by keratinocyte growth factor expression vector transfection, MI503 (50 μM) or phosphate-buffered saline was topically injected for 14 days. The effects of MI503 against cholesteatoma were analyzed by micro-computed tomography images. For the in vivo ototoxicity study, a single intratympanic injection of MI503 (50 or 500 μM) or phosphate-buffered saline (n = 4 each) was done in the ICR mice. An auditory brainstem response was performed at days 0, 1, and 14. For morphological analysis, immunostaining for Phalloidin/F-actin and Myo7a was performed.

RESULTS

MI503 reduced keratinocyte growth factor-induced cholesteatoma in vivo (4 of 4 [100%]). No difference was found in the mean variation of the average of the auditory brainstem response thresholds between the three groups in the in vivo ototoxicity study, thus confirming its safety profile regarding auditory function. MI503 does not demonstrate any deleterious effects on murine hair cells when assessed by immunostaining.

CONCLUSION

These findings demonstrate an encouraging safety profile for the use of menin-MLL inhibitor for the conservative treatment of cholesteatoma.

Analysis of the potential of human cultured nasal epithelial cell sheets to differentiate into airway epithelium

Understanding the expected efficacy and safety of a new regenerative therapy requires analysis of the fate of the transplanted cell graft. We have shown that transplantation of autologous cultured nasal epithelial cell sheets onto the middle ear mucosa can improve middle ear aeration and hearing. However, it remains unknown whether cultured nasal epithelial cell sheets have the potential to gain mucociliary function in the environment of the middle ear because sampling cell sheets after transplantation is challenging. The present study re-cultured cultured nasal epithelial cell sheets in different culture media and evaluated whether the sheets have the potential to differentiate into airway epithelium. Before re-cultivation, cultured nasal epithelial cell sheets fabricated in keratinocyte culture medium (KCM) contained no FOXJ1-positive and acetyl-α-tubulin-positive multiciliated cells or MUC5AC-positive mucus cells. Interestingly, multiciliated cells and mucus cells were observed when the cultured nasal epithelial cell sheets were re-cultured in conditions that promote differentiation of airway epithelium. However, multiciliated cells, mucus cells and CK1-positive keratinized cells were not observed when cultured nasal epithelial cell sheets were re-cultured in conditions that promote epithelial keratinization. These findings support the suggestion that cultured nasal epithelial cell sheets have the ability to differentiate and gain mucociliary function in response to an appropriate environment (possibly including the environment found in the middle ear) but are unable to develop into an epithelial type that differs from its origins.

Radiological and audiological predictors of stapes destruction in adherent pars tensa

PURPOSE

Progressive adherent pars tensa occasionally induces ossicular erosion. Specifically, stapes discontinuity adversely affects postoperative hearing. However, this irretrievable sequela is challenging to prove preoperatively, partly because perimatrix inflammation on the pars tensa can obscure the visibility of the ossicles or the partial volume effect of computed tomography (CT) imaging can hamper detailed ossicular visualization. Therefore, there is no consensus regarding the ideal timing for switching from a wait-and-see approach to a surgical one. Herein, we aimed to explore the potential predictors of stapes superstructure destruction in adherent pars tensa.

METHODS

This retrospective cohort study enrolled consecutive patients who underwent primary tympanoplasty for adherent pars tensa categorized as grade IV on Sadé's grading scale between April 2016 and September 2021. The impact of features on otoscopy and CT and air-bone gap (ABG) on stapes superstructure destruction was assessed using uni- and multivariable logistic regression analyses.

RESULTS

Sixty-four ears were included. Multivariate analysis revealed the presence of debris on the adherent pars tensa (odds ratio [OR] [95% confidence interval {CI}]): 4.799 [1.063-21.668], p = 0.0415), presence of soft-tissue density occupying the oval window (OR [95% CI]: 13.876 [3.084-62.437], p = 0.0006), and a ≥ 20-dB preoperative ABG at 3 kHz (OR [95% CI]: 7.595 [1.596-36.132], p = 0.0108) as independent predictors for stapes superstructure destruction.

CONCLUSION

High preoperative awareness of the possibility of destruction of the stapes superstructure would enable the surgeon to make a timely decision to provide surgical intervention before progression to severe stapes destruction, thereby maintaining long-term satisfactory hearing.

Endoscopic-assisted total maxillectomy with precise surgical margins

In traditional open maxillectomy, identifying the posterior margin is difficult because of its deep location and bleeding from the pterygoid venous plexus. Here, we present our endoscope-assisted total en bloc maxillectomy technique and discuss its merits and demerits compared to previously reported methods. We developed an endoscope-assisted total en bloc maxillectomy procedure. We reviewed a series of total maxillectomies performed with and without endoscopic assistance to verify the advantages of endoscopic assistance over conventional total maxillectomy. We analyzed (1) the precision using the distance of the remaining pterygoid process, (2) the operation time, and (3) blood loss. The length of the remnant pterygoid process was significantly shorter in the endoscopic assistance group. The operation time and blood loss were not significantly different between the two groups. Endoscopic assistance makes total maxillectomy more precise without requiring additional time and is a reasonable option for total maxillectomies.

The pre-chorda and post-chorda tympani approach in endoscopic stapes surgery based on the chorda tympani nerve classification

PURPOSE

In most stapes surgeries, the posterior ear canal is enlarged and a piston is inserted posterior to the chorda tympani nerve (post-chorda tympani approach; Post C). Although reports vary, some indicate that more than 60% of the patients experience lingual symptoms following surgery. Endoscopic surgery may permit an anterior approach to the nerve (pre-chorda tympani approach; Pre C). Herein, we propose a suitable approach for endoscopic stapes surgery based on the classification of the chorda tympani nerve.

METHODS

We retrospectively reviewed the medical records of 23 patients who underwent endoscopic stapes surgery at our institution between 2019 and 2021. The nerve classification previously reported, the modified nerve classification (attached long type is divided into Category 1: lenticular process is visible with 0° endoscope and Category 2: not visible), selected approach (Pre C or Post C), use of a 30° endoscope, and manipulation of the nerve (number of contacts and traction, with or without suction, with or without malposition or extension and amputation, and damage score) were evaluated.

RESULTS

The damage score was significantly lower in the Pre C group (p < 0.05); however, using this approach for all cases is not desirable owing to the high risk of damage to the nerve during posterior malpositioning.

CONCLUSION

The Post C should be used for the detached and attached long 1 types, while the Pre C with a 30° endoscope should be used for the attached long 2, attached short, ultrashort, and external auditory canal types.

Radiological and audiological prediction for hearing outcome in cholesteatoma recidivism surgery

PURPOSE

In cholesteatoma recidivism, achieving satisfactory hearing outcome after revision surgery remains challenging. The presence of concomitant recidivism pathology or related anatomical abnormalities can impact revision reconstruction of the sound transmission system. The current study aimed to identify prognostic factors affecting hearing outcomes after surgery for cholesteatoma recidivism.

METHODS

This retrospective cohort study included consecutive patients whose ears required initial surgery for recidivism between January 2016 and December 2021. Patients followed up for < 6 months and those not indicated for ossiculoplasty were excluded. The impact of preoperative otoscopic findings, computed tomography (CT) features, and hearing levels on the prediction of satisfactory hearing (postoperative air-bone gap [ABG] ≤ 20 dB) was evaluated using univariate and multivariate logistic regression analyses.

RESULTS

Overall, 102 patients were included, with a mean follow-up of 24.8 months. Multivariate logistic regression analysis revealed the following independent predictive factors for satisfactory hearing: presence of aeration in the tympanic cavity (odds ratio [OR] [95% confidence interval {CI}]: 13.287 [1.113-158.604], p = 0.0409), absence of soft-tissue density occupying the oval window (OR [95% CI]: 13.445 [3.178-56.887], p = 0.0040), and ≤ 22.5 dB preoperative ABG in four-frequency average (OR [95% CI]: 9.339 [2.026-43.050], p = 0.0042).

CONCLUSIONS

For cholesteatoma recidivism, reliable preoperative prediction based on CT and ABG would facilitate decision-making regarding the probability of efficient revision ossiculoplasty or appropriate preoperative counseling, including early hearing rehabilitation using hearing aids or implementation of simultaneous implantable hearing equipment during surgery for recidivism.

Endoscopic tympanoplasty type I using interlay technique

Background

Tympanoplasty using the interlay technique has rarely been reported in transcanal endoscopic ear surgery, unlike the underlay technique. This is because many surgeons find it challenging to detach the epithelial layer of the tympanic membrane using only one hand. However, the epithelial layer can be easily detached from the inferior part of the tympanic membrane. Another key point is to actively improve anteroinferior visibility even if the overhang is slight because most perforations and postoperative reperforations are found in the anteroinferior quadrant of the tympanic membrane. We report the application of the interlay technique in endoscopic tympanoplasty type I for tympanic perforations.

Methods

We retrospectively reviewed the medical records of 51 patients who had undergone tympanoplasty using the interlay technique without ossiculoplasty between 2017 and 2020. We then compared the data with those of patients who underwent microscopic surgery (MS) using the underlay technique between 1998 and 2009 (n = 104). No other technique was used in each group during this period. Repair of tympanic membrane perforation and hearing outcomes were assessed for > 1 year postoperatively.

Results

The perforation sites were limited to the anterior, posterior, and anterior–posterior quadrants in 23, 1, and 27 ears, respectively. Perforations were closed in 50 of the 51 ears (98.0%), and the postoperative hearing was good (average air-bone [A-B] gap was 6.8 ± 5.8 dB). The surgical success rate for the repair of tympanic membrane perforation was not significantly different from the MS group (93.3%, P = 0.15). The average postoperative average A-B gap in the group that underwent the interlay technique was significantly different from that in the MS group (10.1 ± 6.6 dB, P < 0.01).

Conclusion

The interlay technique should be considered as one of the treatment methods in endoscopic surgery for tympanic perforations. Further study of the postoperative outcomes of this procedure should be conducted to establish the optimal surgical procedure for tympanic perforations.

Trial registration: This study was retrospectively approved by the Institutional Review Board of the Jikei University, Tokyo, Japan (approval number: 32-205 10286).

Video abstract

Keratinocyte Growth Factor Stimulates Growth of p75+ Neural Crest Lineage Cells During Middle Ear Cholesteatoma Formation in Mice

During development, cranial neural crest (NC) cells display a striking transition from collective to single-cell migration and undergo a mesenchymal-to-epithelial transformation to form a part of the middle ear epithelial cells (MEECs). While MEECs derived from NC are known to control homeostasis of the epithelium and repair from otitis media, paracrine action of keratinocyte growth factor (KGF) promotes the growth of MEECs and induces middle ear cholesteatoma (cholesteatoma). The animal model of cholesteatoma was previously established by transfecting a human KGF-expression vector. Herein, KGF-inducing cholesteatoma was studied in Wnt1-Cre/Floxed-enhanced green fluorescent protein (EGFP) mice that conditionally express EGFP in the NC lineages. The cytokeratin 14-positive NC lineage expanded into the middle ear and formed cholesteatoma. Moreover, the green fluorescent protein-positive NC lineages comprising the cholesteatoma tissue expressed p75, an NC marker, with high proliferative activity. Similarly, a large number of p75-positive cells were observed in human cholesteatoma tissues. Injections of the immunotoxin murine p75-saporin induced depletion of the p75-positive NC lineages, resulting in the reduction of cholesteatoma in vivo. The p75 knockout in the MEECs had low proliferative activity with or without KGF protein in vitro. Controlling p75 signaling may reduce the proliferation of NC lineages and may represent a new therapeutic target for cholesteatoma.

Direct observations of energy transfer from resonant electrons to whistler-mode waves in magnetosheath of Earth

Electromagnetic whistler-mode waves in space plasmas play critical roles in collisionless energy transfer between the electrons and the electromagnetic field. Although resonant interactions have been considered as the likely generation process of the waves, observational identification has been extremely difficult due to the short time scale of resonant electron dynamics. Here we show strong nongyrotropy, which rotate with the wave, of cyclotron resonant electrons as direct evidence for the locally ongoing secular energy transfer from the resonant electrons to the whistler-mode waves using ultra-high temporal resolution data obtained by NASA’s Magnetospheric Multiscale (MMS) mission in the magnetosheath. The nongyrotropic electrons carry a resonant current, which is the energy source of the wave as predicted by the nonlinear wave growth theory. This result proves the nonlinear wave growth theory, and furthermore demonstrates that the degree of nongyrotropy, which cannot be predicted even by that nonlinear theory, can be studied by observations.

Excitation of whistler-mode waves by cyclotron instability is considered as the likely generation process of the waves. Here, the authors show direct observational evidence for locally ongoing secular energy transfer from the resonant electrons to the whistler-mode waves in Earth’s magnetosheath.

Preoperative prediction by artificial intelligence for mastoid extension in pars flaccida cholesteatoma using temporal bone high-resolution computed tomography: A retrospective study

Cholesteatoma is a progressive middle ear disease that can only be treated surgically but with a high recurrence rate. Depending on the extent of the disease, a surgical approach, such as microsurgery with a retroarticular incision or transcanal endoscopic surgery, is performed. However, the current examination cannot sufficiently predict the progression before surgery, and changes in approach may be made during the surgery. Large amounts of data are typically required to train deep neural network models; however, the prevalence of cholesteatomas is low (1-in-25, 000). Developing analysis methods that improve the accuracy with such a small number of samples is an important issue for medical artificial intelligence (AI) research. This paper presents an AI-based system to automatically detect mastoid extensions using CT. This retrospective study included 164 patients (80 with mastoid extension and 84 without mastoid extension) who underwent surgery. This study adopted a relatively lightweight neural network model called MobileNetV2 to learn and predict the CT images of 164 patients. The training was performed with eight divided groups for cross-validation and was performed 24 times with each of the eight groups to verify accuracy fluctuations caused by randomly augmented learning. An evaluation was performed by each of the 24 single-trained models, and 24 sets of ensemble predictions with 23 models for 100% original size images and 400% zoomed images. Fifteen otolaryngologists diagnosed the images and compared the results. The average accuracy of predicting 400% zoomed images using ensemble prediction model was 81.14% (sensitivity = 84.95%, specificity = 77.33%). The average accuracy of the otolaryngologists was 73.41% (sensitivity, 83.17%; specificity, 64.13%), which was not affected by their clinical experiences. Noteworthily, despite the small number of cases, we were able to create a highly accurate AI. These findings represent an important first step in the automatic diagnosis of the cholesteatoma extension.

MRI tractography reveals the human olfactory nerve map connecting the olfactory epithelium and olfactory bulb

The olfactory nerve map describes the topographical neural connections between the olfactory epithelium in the nasal cavity and the olfactory bulb. Previous studies have constructed the olfactory nerve maps of rodents using histological analyses or transgenic animal models to investigate olfactory nerve pathways. However, the human olfactory nerve map remains unknown. Here, we demonstrate that high-field magnetic resonance imaging and diffusion tensor tractography can be used to visualize olfactory sensory neurons while maintaining their three-dimensional structures. This technique allowed us to evaluate the olfactory sensory neuron projections from the nasal cavities to the olfactory bulbs and visualize the olfactory nerve maps of humans, marmosets and mice. The olfactory nerve maps revealed that the dorsal-ventral and medial-lateral axes were preserved between the olfactory epithelium and olfactory bulb in all three species. Further development of this technique might allow it to be used clinically to facilitate the diagnosis of olfactory dysfunction.

Combined high-field MRI and DTI analyses in post-mortem mouse, marmoset, and human samples provide insight into the neural connections between nasal cavities and olfactory bulbs.

Combined analysis of finite element model and audiometry provides insights into the pathogenesis of conductive hearing loss

The middle ear transmits sound to the inner ear via vibrations in the eardrum and ossicles, and damage to the middle ear results in conductive hearing loss. Although conductive hearing loss can be corrected by surgery, the currently available clinical investigations cannot always diagnose the ossicular chain pathology underlying the conductive hearing loss, and even intraoperative findings can be equivocal. Acoustic analysis using finite element models (FEMs) can simulate the sound pressure change at an arbitrary site for each frequency. FEMs are used in acoustic engineering to simulate the frequency-dependent sound pressure distribution at discrete cells in a simulated model and analyze the effects of specific parameters on the audiogram. However, few reports have compared the numerical results obtained using FEMs with data from clinical cases. We used FEMs to simulate audiograms of the air-bone gap (ABG) for various ossicular chain defects and compared these with preoperative audiograms obtained from 44 patients with a normal tympanic membrane who had otosclerosis, middle ear malformations or traumatic ossicular disruption. The simulated audiograms for otosclerosis and attic fixation of the malleus-incus complex both exhibited an up-slope but could be distinguished from each other based on the ABG at 1000 Hz. The simulated audiogram for incudostapedial joint discontinuity exhibited a peak at around 750 Hz and a down-slope above 1000 Hz. In general, the simulated audiograms for otosclerosis, attic fixation and incudostapedial joint discontinuity were consistent with those obtained from clinical cases. Additional simulations indicated that changes in ossicular mass had relatively small effects on ABG. Furthermore, analyses of combination pathologies suggested that the effects of one defect on ABG were added to those of the other defect. These FEM-based findings provide insights into the pathogenesis of conductive hearing loss due to otosclerosis, middle ear malformations and traumatic injury.

miR-34a predicts the prognosis of advanced-stage external auditory canal squamous cell carcinoma

BACKGROUND

External auditory canal (EAC) squamous cell carcinoma (SCC) is a rare disease, and the survival rate is low in the advanced stages. It has been reported that miR-34a expression is low in many cancers and acts as a tumor suppressor, but its function in EACSCC has not yet been reported.

AIMS

To analyze the miR-34a expression levels in EACSCC specimens using in situ hybridization (ISH).

MATERIAL AND METHODS

We performed microRNA ISH for miR-34a detection and immunohistochemical analysis of p53 and Ki67 in the EACSCC and otitis externa (OE) specimens.

RESULTS

miR-34a was expressed in the basal and suprabasal layers in the OE epidermis. The pronounced expression of miR-34a was observed in the two cases of T2 (Stage II). In the one case of T3 (Stage III), it was almost the same as that of the OE. On the other hand, the expression levels of miR-34a in the one case of T3 (Stage IV) and two cases of T4 (Stage IV) were apparently reduced.

CONCLUSION

We demonstrated that the expression level of miR-34a was higher in early-stage EACSCC and lower in advanced-stage EACSCC.

SIGNIFICANCE

The expression level of miR-34a may predict a prognosis in patients with advanced-stage EACSCC.

Collaborative Research Activities of the Arase and Van Allen Probes

This paper presents the highlights of joint observations of the inner magnetosphere by the Arase spacecraft, the Van Allen Probes spacecraft, and ground-based experiments integrated into spacecraft programs. The concurrent operation of the two missions in 2017-2019 facilitated the separation of the spatial and temporal structures of dynamic phenomena occurring in the inner magnetosphere. Because the orbital inclination angle of Arase is larger than that of Van Allen Probes, Arase collected observations at higher L -shells up to L ∼ 10 . After March 2017, similar variations in plasma and waves were detected by Van Allen Probes and Arase. We describe plasma wave observations at longitudinally separated locations in space and geomagnetically-conjugate locations in space and on the ground. The results of instrument intercalibrations between the two missions are also presented. Arase continued its normal operation after the scientific operation of Van Allen Probes completed in October 2019. The combined Van Allen Probes (2012-2019) and Arase (2017-present) observations will cover a full solar cycle. This will be the first comprehensive long-term observation of the inner magnetosphere and radiation belts.

Quantitative Study of Bone Removal Region in Transcanal Endoscopic Approach to the Attic and Antrum Using a 70° Endoscope

BACKGROUND

Transcanal endoscopic ear surgery enables surgeons to operate with few blind areas, and using an angled endoscope expands its usefulness. We have previously reported the usefulness of a 70° endoscope in transcanal endoscopic ear surgery, but no quantitative study has been performed. We quantitatively clarified the difference between a microscope and various endoscopes in the bone removal region, especially a 70° endoscope, in the transcanal approach.

METHODS

A temporal bone model for ear surgery training was used to compare the use of a microscope, a 0° endoscope, a 30° endoscope, a 45°endoscope, and a 70° endoscope. The drilled mass during atticotomy or atticoantrostomy and the size of the reconstructed graft were measured when the formed pseudo-lesion was removed.

RESULTS

The amount of bone excision was 57% and the size of the reconstructed graft was 32% when using a 70° endoscope compared with the case of using a microscope, both of which were the smallest of the various endoscopes.

CONCLUSION

It was quantitatively shown that using a 70° endoscope in transcanal endoscopic ear surgery reduced the bone removal region. We believe that a 70° endoscope is a useful tool for performing a minimally invasive and reliable surgery.

Analysis of the epidermal growth factor receptor/phosphoinositide‐dependent protein kinase‐1 axis in tumor of the external auditory canal in response to epidermal growth factor stimulation

Objectives

The epidermal growth factor receptor (EGFR) is related to the invasion and metastasis of external auditory canal (EAC) squamous cell carcinoma (SCC). The phosphoinositide‐dependent protein kinase‐1 (PDPK1) accelerates tumor cell growth through anti‐apoptotic signaling under the influence of downstream EGFR‐mediated signaling pathways. In this study, we investigated the EGFR/PDPK1 axis in the EAC under EGF stimulation.

Methods

We confirmed EGFR and PDPK1 expression in human EACSCC specimens immunohistochemically. We next transfected the EGF expression vector in the mouse EAC and then conducted a PDPK1 inhibitory experiment. Immunohistochemical analysis was performed in the mouse EAC, using anti‐EGF, anti‐EGFR, anti‐PDPK1, and anti‐Ki67 antibodies. Immunohistochemical analysis of cleaved caspase‐3 and terminal deoxy(d)‐UTP nick end labeling (TUNEL) detection assays were also performed for the assessment of apoptosis in the inhibitory experiment.

Results

Immunohistochemical analysis revealed overexpression and colocalization of EGFR and PDPK1 in human EACSCC specimens. The growth of a protuberant tumor was observed in the mouse EAC in which EGF expression vector was transfected, and EGF, EGFR, PDPK1, and Ki67 labeling indexes (LIs) were significantly increased. PDPK1 inhibition then induced normal epithelial appearance in the EAC. Moreover, EGF, EGFR, PDPK1, and Ki67 LIs were decreased, and cleaved caspase‐3 and TUNEL LIs were increased in the EAC.

Conclusion

We demonstrated the possibility that PDPK1 plays an important role in EACSCC.

Level of Evidence: NA.

Transplantation of a human induced pluripotent stem cell-derived airway epithelial cell sheet into the middle ear of rats

Introduction

Early postoperative regeneration of the middle ear mucosa is essential for the prevention of postoperative refractory otitis media and recurrent cholesteatoma. As a means for intractable otitis media management, we focused on human induced pluripotent stem cell (hiPSC)-derived airway epithelial cells (AECs), which have been used in upper airway mucosal regeneration and transplantation therapy. In this study, we transplanted hiPSC-derived AECs into the middle ear of immunodeficient rats.

Methods

Following the preparation of AEC sheets from hiPSCs, the bilateral middle ear mucosa of X-linked severe combined immunodeficient rats was scraped, and the AEC sheets were transplanted in the ears unilaterally.

Results

Human nuclear antigen (HNA)-positive ciliated cells were observed on the transplanted side of the middle ear cavity surface in three of six rats in the 1-week postoperative group and in three of eight rats in the 2-week postoperative group. No HNA-positive cells were found on the control side. The percentage of HNA-positive ciliated cells in the transplanted areas increased in the 2-week postoperative group compared with the 1-week group, suggesting survival of hiPSC-derived AECs. Additionally, HNA-positive ciliated cells were mainly located at sites where the original ciliated cells were localized. Immunohistochemical analysis showed that the transplanted AECs contained cytokeratin 5- and mucin 5AC-positive cells, indicating that both basal cells and goblet cells had regenerated within the middle ear cavity.

Conclusions

The results of this study are an important first step in the establishment of a novel transplantation therapy for chronic otitis media.

•

hiPSC-derived airway epithelial cells were transplanted into the middle ear of rats.

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Engrafted cells mainly survived in the ciliated region of the middle ear.

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Ciliated, goblet, and basal cells were confirmed in the engrafted cells.

Improved assessment of middle ear recurrent/residual cholesteatomas using temporal subtraction CT

PURPOSE

The purpose of this study was to investigate the usefulness of temporal subtraction CT (TSCT) of temporal bone CT for the detection of postoperative recurrent/residual cholesteatoma of the middle ear.

METHODS

Thirty-two consecutive patients with surgically proven postoperative recurrent/residual cholesteatoma and 14 consecutive patients without recurrent/residual lesion matched the selection criteria and were retrospectively evaluated. TSCT imaging was generated with the use of serial postoperative CT. Two experienced radiologists and two residents evaluated the presence of bone erosive change by comparison serial CT studies, and CT and TSCT. The detection rate of bone erosive change, sensitivity and specificity of the recurrence/residual lesions, and reading time for each reader were evaluated.

RESULTS

TSCT + CT significantly improved the detection of bone erosive changes compared to CT-only evaluation (17.4-41.3% vs. 37.0-58.7%, p = 0.008-0.046). The mean sensitivity and specificity of TSCT + CT for experienced radiologists were 0.77 and 1.00, and 0.52 and 0.97 without TSCT. The mean sensitivity and specificity of TSCT + CT for residents were 0.64 and 1.00, and 0.41 and 1.00 without TSCT. Sensitivity showed an increase in all readers. The use of TSCT significantly reduced the reading time per case in all readers (p < 0.001).

CONCLUSION

TSCT improves the depiction of newly occurring progressive bone erosive changes, and detection sensitivity and reading time in postoperative recurrence/residual cholesteatoma of middle ear.

Radiological and Audiological Prediction for Ossicular Fixation in Chronic Otitis Media and Tympanic Membrane Perforation

OBJECTIVES

Recurrent middle-ear infection can lead to ossicular fixation, adversely affecting post-tympanoplasty hearing outcomes. Preoperative prediction of ossicular fixation remains challenging. We aimed to investigate potential predictors of ossicular fixation in patients with chronic otitis media.

STUDY DESIGN

Retrospective.

SETTING

Tertiary academic medical center.

PATIENTS

Patients with noncholesteatomatous chronic otitis media and tympanic membrane perforation, without ossicular discontinuities.

INTERVENTIONS

Diagnostic.

MAIN OUTCOME MEASURES

The fixation of each ossicle was assessed during tympanoplasty. The impact of preoperative otoscopic findings, computed tomography (CT) features, and hearing levels on the prediction of ossicular fixation was evaluated using uni- and multivariable logistic regression analyses.

RESULTS

One hundred thirty-five patients were included. Soft-tissue density between the malleus head and the anterior wall (odds ratio, 3.789 [95% confidence interval, 1.177-12.196]; p = 0.0255) and poor development of mastoid cells (16.826 [2.015-134.520]; p = 0.0078) were independent predictors of malleus fixation. In addition, ≥50% tympanic membrane perforation (5.412 [1.908-15.353]; p = 0.0015), poor development of mastoid cells (3.386 [1.039-11.034]; p = 0.0431), and a ≥40-dB preoperative air-bone gap (ABG) at 500 Hz (4.970 [1.732-14.261]; p = 0.0029) were independent predictors of incus fixation. Soft-tissue density surrounding the stapes (18.833 [1.856-191.104]; p = 0.0119) and a ≥40-dB preoperative ABG at 500 Hz (13.452 [1.640-∞]; p = 0.0138) were correlated with stapes fixation.

CONCLUSIONS

The accurate prediction of ossicular fixation in patients with chronic otitis media based on CT features and the ABG may facilitate decision-making regarding the need for ossiculoplasty, possibly avoiding unnecessary manipulation or overlooking of fixation.

OUP accepted manuscript

The spiral ganglion of the cochlea is essential for hearing and contains primary bipolar neurons that relay action potentials generated by mechanosensory hair cells. Injury to spiral ganglion neurons (SGNs) causes permanent hearing loss because these cells have limited regenerative capacity. Establishment of human cell-derived inner ear tissue in vitro could facilitate the development of treatments for hearing loss. Here, we report a stepwise protocol for differentiating human-induced pluripotent stem cells (hiPSCs) into otic organoids that contain SGN-like cells and demonstrate that otic organoids have potential for use as an experimental model of drug-induced neuropathy. Otic progenitor cells (OPCs) were created by 2D culture of hiPSCs for 9 days. Otic spheroids were formed after 2D culture of OPCs for 2 days in a hypoxic environment. Otic organoids were generated by 3D culture of otic spheroids under hypoxic conditions for 5 days and normoxic conditions for a further 30 days or more. The protein expression profile, morphological characteristics, and electrophysiological properties of SGN-like cells in otic organoids were similar to those of primary SGNs. Live-cell imaging of AAV-syn-EGFP-labeled neurons demonstrated temporal changes in cell morphology and revealed the toxic effects of ouabain (which causes SGN-specific damage in animal experiments) and cisplatin (a chemotherapeutic drug with ototoxic adverse effects). Furthermore, a cyclin-dependent kinase-2 inhibitor suppressed the toxic actions of cisplatin on SGN-like cells in otic organoids. The otic organoid described here is a candidate novel drug screening system and could be used to identify drugs for the prevention of cisplatin-induced neuropathy.

Optimal Multiple-Layered Anterior Skull Base Reconstruction Using a 360° Suturing Technique

BACKGROUND

Advances in technique and instrumentation have improved outcomes after resection of anterior skull base tumors. However, cerebrospinal fluid (CSF) leak occurs in 4%-20% of patients. To reduce the risk of CSF leak, we have developed a novel reconstruction technique that consists of a 4-layered graft with patchwork suturing and hard material.

OBJECTIVE

To evaluate the effectiveness of this reconstruction technique when used for resection of anterior skull base tumors.

METHODS

This case series included 59 patients with anterior skull base tumors in whom the 4-layered closure technique was used. The main outcome measures were complications, including CSF leak, meningitis, postoperative bleeding, and infection.

RESULTS

There were no CSF leak cases or serious complications after closure of the anterior skull base using the 4-layered technique.

CONCLUSION

Closure of the anterior skull base in 4 layers prevented CSF leak and was not associated with any serious complications. However, further studies in larger numbers of patients are needed to confirm our outcomes using this closure method.

Maturation of odour identification ability and related factors in children

BACKGROUND

Olfaction plays an important role in our daily and social lives, both as adults and as children. This study assessed whether the ability to identify odours increases with age, as well as the ability in various age groups and the factors involved.

METHODS

The survey was performed in 2017 on 697 Japanese children (366 girls and 331 boys) aged 6-18 years who lived in Tsunan, Niigata Prefecture, Japan by using the 'Open Essence', a card-type odour identification test. We collected information regarding age, sex, and physical characteristic. We also inquired whether participants had siblings or if members of the family smoked, and whether they had conversations about odour at home. Statistical analysis was performed to evaluate the factors affecting odour identification abilities.

RESULTS

The results showed that the odour identification abilities of children increase with age, and children who have daily conversations about odours at home have better odour identification abilities.

CONCLUSIONS

Odour identification ability increases with age. In addition, our findings suggest that conversation may positively affect odour identification. Hence, it is important for children to be exposed to an environment where they develop an interest in smells for better growth of their olfactory identification ability.

Heterogeneous distribution of mature olfactory sensory neurons in human olfactory epithelium

BACKGROUND

The olfactory cleft (OC) comprising the olfactory epithelium (OE) is the most important anatomical location for olfactory function. Endoscopic sinus surgery (ESS) is used to treat diseases related to the OC and improve olfactory dysfunction. However, iatrogenic OE injury occasionally occurs. Comprehensive knowledge of the olfactory region is required to avoid damage to the OE during endoscopic procedures.

METHODS

Immunohistochemistry was performed on olfactory mucosa obtained from the unaffected side of olfactory neuroblastoma surgical specimens. The OE was defined as the epithelium containing mature olfactory sensory neurons (OSNs). The distribution and cell kinetics of the OE were examined.

RESULTS

The OE was selectively localized to the anterior two-thirds of the superior turbinate (ST) and in the nasal septum (NS) just opposite to the ST; the OE was not detected within the mucosa of the superior meatus. The density of mature OSNs was high at the ethmoid tegmen but gradually decreased with distance from the ethmoid tegmen. The extent of cell death and proliferation was relatively even across the OE. Analysis of airflow profiles revealed that resection of inferior ST does not decrease airflow to the OC.

CONCLUSION

The results indicate that the distribution and degree of differentiation of mature OSNs are heterogenous throughout the OE. Epithelial resection of the anterior or superior ST has the potential to damage olfactory function. Resection of the inferior or posterior ST or widening of the superior meatus is a safer alternative that does not damage mature OSNs or alter airflow to the OC.

How I Do It: Inferior Turbinectomy: Modified Techniques for Submucosal Resection

Although inferior turbinectomy with submucosal resection effectively reduces the volume of the inferior turbinate, there is room for improvement in surgical procedures. Techniques have been developed to reduce crusting and bleeding while efficiently achieving volume reduction. State-of-the-art procedures pertaining to the local injection site, incision line, exposure of the periosteum, submucosal outfracture of the turbinate bone, trimming of redundant mucosa, and incision line suturing are described. Pre and postoperative Nasal Obstruction Symptom Evaluation (NOSE) scores and postoperative inferior turbinate bleeding and crusting were evaluated. For the 18 consecutive patients analyzed, the pre and postoperative NOSE scores were 67.8 ± 14.8 and 16.1 ± 13.0, respectively (P = .0002). Postoperatively, bleeding was absent, and only minor suture thread crusting was observed in 13 patients. In conclusion, our novel technique improves the effectiveness of surgery as well as the postoperative quality of the inferior turbinate.

Imaging predictor of ophthalmic involvement in maxillary sinus cancer during super selective intra-arterial cisplatin infusion and concomitant radiotherapy (RADPLAT)

Objective

To investigate the predictability of ophthalmic artery involvement in maxillary sinus cancer using preprocedural contrast enhanced CT and MRI.

Methods

We analyzed advanced (T3, T4a, and T4b) primary maxillary sinus squamous cell carcinoma treated with super-selective intra-arterial cisplatin infusion and concomitant radiotherapy (RADPLAT) from Oct 2016 to Mar 2020. Two diagnostic radiologists evaluated the tumor invasion site around the maxillary sinus using preprocedural imaging. These results were compared with the angiographic involvement of the ophthalmic artery using statistical analyses. We also evaluated our RADPLAT quality using complication rate, response to treatment, local progressive free survival (LPFS), and overall survival (OS).

Results

Twenty patients were included in this study. There were ten cases of ophthalmic artery tumor stain and there was a correlation between ophthalmic artery involvement and invasion for ethmoid sinus with statistically significant differences. Other imaging findings were not associated with ophthalmic artery involvement.

Conclusions

Ethmoid sinus invasion on preprocedural imaging could suggest ophthalmic artery involvement in maxillary sinus cancer. It may be useful in predicting prognosis and treatment selection.

Paving the way for application of next generation risk assessment to safety decision-making for cosmetic ingredients

Next generation risk assessment (NGRA) is an exposure-led, hypothesis-driven approach that has the potential to support animal-free safety decision-making. However, significant effort is needed to develop and test the in vitro and in silico (computational) approaches that underpin NGRA to enable confident application in a regulatory context. A workshop was held in Montreal in 2019 to discuss where effort needs to be focussed and to agree on the steps needed to ensure safety decisions made on cosmetic ingredients are robust and protective. Workshop participants explored whether NGRA for cosmetic ingredients can be protective of human health, and reviewed examples of NGRA for cosmetic ingredients. From the limited examples available, it is clear that NGRA is still in its infancy, and further case studies are needed to determine whether safety decisions are sufficiently protective and not overly conservative. Seven areas were identified to help progress application of NGRA, including further investments in case studies that elaborate on scenarios frequently encountered by industry and regulators, including those where a ‘high risk’ conclusion would be expected. These will provide confidence that the tools and approaches can reliably discern differing levels of risk. Furthermore, frameworks to guide performance and reporting should be developed.

Preemptive analgesia for endoscopic sinus surgery: a retrospective study

BACKGROUND

Chronic rhinosinusitis (CRS) is a common disease, and endoscopic sinus surgery (ESS) is widely performed. However, there is no consensus regarding postoperative pain control after ESS, and postoperative opioid abuse is a problem in many countries. Acetaminophen is reportedly effective for postoperative pain control. Preemptive analgesia has received more attention lately, wherein pain is prevented before it occurs. In this study, we assessed the use of acetaminophen for preemptive analgesia during the perioperative period in ESS.

METHODOLOGY

This is a retrospective study of 175 patients who underwent ESS, septoplasty, and bilateral inferior turbinate mucosal resection at our hospital from April 2016 to February 2018. In total, 82 patients received 1,000 mg of acetaminophen during surgery and 4 hours after the first dose, while 93 patients did not receive it routinely. We compared these two groups. The primary outcome was the need to use additional analgesics prescribed by the ward physician and the secondary outcomes included postoperative pain, postoperative bleeding, reoperation, blood pressure, and body temperature.

RESULTS

The use of additional oral and intravenous analgesics was significantly reduced in the patients who received acetaminophen perioperatively.

CONCLUSION

Preemptive analgesia during the perioperative period of ESS could lead to satisfactory postoperative pain control.

Advanced Endoscopic Endonasal Approach to the Pterygopalatine Fossa and Orbit: The Endoscopic Tri-port Approach

Objective  The pterygopalatine fossa (PPF) is a narrow space situated posterior to the maxillary sinus. While external approaches have been used to treat tumors of the PPF, recent endoscopic approaches have become favored as an alternative; we developed an endoscopic tri-port approach, which provides wide surgical corridor with minimal invasion, for PPF. This report aims to introduce and verify the new approach. Design  Case series. Setting  A tertiary referral hospital. Participants  We reviewed 11 patients with PPF or orbital tumors who were treated with the endoscopic tri-port approach. Main Outcome Measures  Accessing tri-port approach's effects and limitations. Results  When the tumor was located in the PPF or orbit without intracranial invasion, en bloc resection was achieved in six patients. With the exception of one patient, the nasal septum was preserved if not used for skull base reconstruction. If not invaded by a tumor or necessary for reconstruction, the inferior and middle turbinates were preserved. Conclusion  The endoscopic tri-port approach provides an excellent surgical view and wide corridor and not requires an external approach, including a gingival incision.

Squamous and Respiratory Metaplasia After Olfactory Mucosal Resection

Resection of the olfactory mucosa (OM) is sometimes unavoidable during surgery; however, it is not known whether the OM can completely recover thereafter. The aim of this study was to uncover whether the OM fully recovers after mucosal resection and describe the process of OM regeneration. 8-week-old male Sprague–Dawley rats (n = 18) were subjected to OM resection at the nasal septum; six rats were euthanized for histological examination 0, 30, and 90 days after surgery. Immunohistochemistry was performed to identify olfactory receptor neuron (ORN) lineage cells [mature and immature ORNs and ORN progenitors, and olfactory ensheathing cells (OECs)], as well as dividing and apoptotic cells. Squamous and respiratory metaplasia and inflammatory cell infiltration were also assessed. On day 30 after resection, the mucosa had regenerated, and mainly contained thin nerve bundles, basal cells, and immature ORNs, with a few mature ORNs and OECs. On day 90, the repaired nasal mucosa had degenerated into stratified squamous or ciliated pseudostratified columnar epithelia, with reducing ORNs. The lamina propria contained numerous macrophages. Partial regeneration was observed within 1 month after OM resection, whereas subsequent degeneration into squamous and respiratory epithelia occurred within 3 months. Given the poor persistence of ORNs and OECs, OM resection is likely to result in olfactory impairment. Overall, surgeons should be cautious not to injure the OM during surgery.

Long-term oral administration of transgenic rice containing cedar pollen T-cell epitopes potentially improves medication- and allergy-related quality-of-life scores

Background: We previously developed a transgenic rice that contains seven linked human predominant T-cell epitopes (7Crp) derived from Japanese cedar (JC) pollen allergens Cry j 1 and Cry j 2. Oral administration of 80 g of transgenic rice for 20 weeks suppressed allergen-specific T-cell proliferation in participants with JC pollinosis, but their clinical symptoms did not improve. Objective: We examined the clinical efficacy of low-dose (5 g and 20 g) intake of the transgenic rice administered for two successive seasons. Methods: In this randomized, double-blind, placebo controlled study, transgenic rice seeds (5 g or 20 g) were orally administered to the participants for 24 weeks in each of two successive JC pollen seasons. We analyzed T-cell proliferation and cytokine expression, and monitored symptom and medication scores during the pollen season. Quality of life (QOL) was evaluated by using the Japanese Allergic Rhinitis Quality of Life Standard Questionnaire (JRQLQ). Results: Specific T-cell proliferation after stimulation with 7Crp, Cry j 1, and Cry j 2 was significantly suppressed in the second JC pollen season. No significant differences were found among the three groups (5 g, 20 g, and placebo) with regard to clinical symptoms or medication scores in the first season. However, the medication scores and face scale for overall condition of JRQLQ improved in the 5-g transgenic rice group in the second season, although careful re-examination with a large sample size is necessary to confirm the results. Conclusion: Low-dose oral administration of transgenic rice that contains 7Crp significantly reduced allergen-specific T-cell responses and improved medication scores during the second season of administration. Thus, oral intake of the transgenic rice has the potential to induce immune tolerance to JC pollen allergens when administered for at least two successive seasons.

Super-enhancer Acquisition Drives FOXC2 Expression in Middle Ear Cholesteatoma

Distinct histone modifications regulate gene expression in certain diseases, but little is known about histone epigenetics in middle ear cholesteatoma. It is known that histone acetylation destabilizes the nucleosome and chromatin structure and induces gene activation. The association of histone acetylation with chronic inflammatory diseases has been indicated in recent studies. In this study, we examined the localization of variously modified histone H3 acetylation at lysine 9, 14, 18, 23, and 27 in paraffin-embedded sections of human middle ear cholesteatoma (cholesteatoma) tissues and the temporal bones of an animal model of cholesteatoma immunohistochemically. As a result, we found that there was a significant increase of the expression levels of H3K27ac both in human cholesteatoma tissues and the animal model. In genetics, super-enhancers are clusters of enhancers that drive the transcription of genes involved in cell identity. Super-enhancers were originally defined using the H3K27ac signal, and then we used H3K27ac chromatin immunoprecipitation followed by sequencing to map the active cis-regulatory landscape in human cholesteatoma. Based on the results, we identified increased H3K27ac signals as super-enhancers of the FOXC2 loci, as well as increased protein of FOXC2 in cholesteatoma. Recent studies have indicated that menin-MLL inhibitor could suppress tumor growth through the control of histone H3 modification. In this study, we demonstrated that the expression of FOXC2 was inhibited by menin-MLL inhibitor in vivo. These findings indicate that FOXC2 expression under histone modifications promoted the pathogenesis of cholesteatoma and suggest that it may be a therapeutic target of cholesteatoma.

Management and surgical approach ingenuity for nasal fibro-osseous lesions at our facility: A case series of 15 patients

To retrospectively evaluate our treatment algorithm and surgical approaches for nasal fibro-osseous lesions at our hospital. Fifteen patients with nasal fibro-osseous lesions treated from January 1, 2010, to January 31, 2020 were included. Among them, 13 patients who underwent surgery were divided into groups A and B, based on whether they were treated before or after the treatment algorithm was established. The extent of the lesion, surgical approach, and outcomes, including bone regrowth assessed postoperatively using computed tomography at 6 months, were analyzed. In group A, six cases were treated via endoscopy and two via a combined endoscopy and external approach. In group B, three cases were treated via endoscopy, one via combined endoscopy and external approach, and one combined with craniotomy. Two group A cases and no group B cases had residual lesions postoperatively. Postoperative bone regrowth occurred in three group A patients and no group B patients. Multi-angled approaches for nasal fibro-osseous lesions based on the unified treatment algorithms used in the study may lead to a reduction in postoperative recurrence and complication rates.