Effect of intranasal administration of concentrated growth factors on regeneration of the olfactory epithelium in an olfactory dysfunction-induced rat model.

OBJECTIVE: The development of treatments that promote the regenerative capacity of the olfactory epithelium (OE) is desirable. This study aimed to evaluate the effects of intranasal administration of concentrated growth factors (CGFs) in a rat model of olfactory dysfunction. STUDY DESIGN: Animal study. METHODS: Nineteen male rats were used. Fourteen olfactory dysfunction models were created by intraperitoneal administration of 3-methylindole. We randomly divided the rats from the olfactory dysfunction model after 1 week into the CGF or saline group; CGFs were administered to seven animals and saline to seven animals. Behavioral assessments using the avoidance test were conducted until day 28 after CGF/saline administration. On day 28, histological evaluation was conducted to determine olfactory epithelial thickness and the olfactory marker protein (OMP)-positive cell count. Five animals were intraperitoneally injected with saline as the control group. RESULTS: The avoidance rate remained decreased until 28 days after CGF/saline administration, and there was no significant difference between the two groups. Olfactory epithelial thicknesses on day 28 were 38.64 ± 3.17 µm and 32.84 ± 4.50 µm in the CGF and saline groups, respectively. OE thickness was significantly thicker in the CGF group than in the saline group (P = 0.013). The numbers of OMP-positive cells were 40.29 ± 9.77/1.0 × 104 µm2 and 31.00 ± 3.69/1.0 × 104 µm2 in the CGF and saline groups, respectively. The number of OMP+ cells in the CGF group was significantly increased compared with that in the saline group (P = 0.009). Both groups showed no improvement compared with the control group (OE thickness: 54.08 ± 3.36 µm; OMP+ cell count: 56.90 ± 9.91/1.0 × 104 µm2). CONCLUSIONS: The CGF group showed improved olfactory epithelial thickness and OMP-positive cell numbers compared with that in the saline group.

Development of a proficiency-based training curriculum for beginners in endoscopic endonasal surgery.

OBJECTIVE: Precise endoscopic skills are critical for endoscopic endonasal surgery (EES) to ensure patient safety, as well as to succeed as a surgeon. Among these skills, basic skills such as hand-eye coordination and bimanual dexterity are the most important skills for novice surgeons. However, there is no proficiency-based training for the basic skills in EES. In this study, we aimed to develop a proficiency-based training curriculum for beginners in EES using tractable tasks and to assess the curriculum's validity and educational benefits. METHODS: Training tasks for basic surgical skills of EES were created by experts, using a low-cost and simple simulator. Subsequently, a proficiency-based training curriculum was developed through a preliminary study. The face and content validity of the curriculum was evaluated by expert surgeons. The construct validity was confirmed by comparing the scores of the medical students with those of the experts. In addition, the educational benefits of the curriculum were assessed by comparing the scores of the medical students before and after the implementation of the curriculum. RESULTS: A proficiency-based training curriculum using six tractable tasks was developed in the preliminary study. Replication of real surgical situation, camera navigation, and instrument operability under endoscopy were all highly appreciated (4.6, 4.6, and 4.8 out of 5 points, respectively), which indicates face validity. The content validity of the curriculum was demonstrated by the results of the questionnaire (4.4 out of 5 points). The curriculum was implemented by 12 medical students. The initial student scores were significantly lower than the expert scores (mean score: 61.9 vs. 100.0, p < 0.001), and each coefficient of variation of the student scores was higher than that of the expert scores (p < 0.01), supporting the construct validity of the curriculum. The mean student composite scores were statistically improved after the training (61.9 vs. 93.3, p < 0.0001). In addition, improvement of five other medical students' EES skills through this training curriculum was confirmed in cadaver dissection (1.7 vs. 3.7, p < 0.0001). CONCLUSION: The validity of the proficiency-based training curriculum developed through the preliminary study was established based on the questionnaire of experts and the difference between student and expert scores. In addition, the educational benefits were demonstrated by the students' learning curves. The low-cost and simple simulator seems appropriate as an entry model for beginners in EES, and this curriculum can provide rapid intervention and objective assessment of basic skills in EES.

Cricotracheostomy for patients with severe COVID-19: A case control study.

Background: Tracheostomy is an important procedure for the treatment of severe coronavirus disease-2019 (COVID-19). Older age and obesity have been reported to be associated with the risk of severe COVID-19 and prolonged intubation, and anticoagulants are often administered in patients with severe COVID-19; these factors are also related to a higher risk of tracheostomy. Cricotracheostomy, a modified procedure for opening the airway through intentional partial cricoid cartilage resection, was recently reported to be useful in cases with low-lying larynx, obesity, stiff neck, and bleeding tendency. Here, we investigated the usefulness and safety of cricotracheostomy for severe COVID-19 patients. Materials and methods: Fifteen patients with severe COVID-19 who underwent cricotracheostomy between January 2021 and April 2022 with a follow-up period of ≥ 14 days were included in this study. Forty patients with respiratory failure not related to COVID-19 who underwent traditional tracheostomy between January 2015 and April 2022 comprised the control group. Data were collected from medical records and comprised age, sex, body mass index, interval from intubation to tracheostomy, use of anticoagulants, complications of tracheostomy, and decannulation. Results: Age, sex, and days from intubation to tracheostomy were not significantly different between the COVID-19/cricotracheostomy and control/traditional tracheostomy groups. Body mass index was significantly higher in the COVID-19 group than that in the control group (P = 0.02). The rate of use of anticoagulants was significantly higher in the COVID-19 group compared with the control group (P < 0.01). Peri-operative bleeding, subcutaneous emphysema, and stomal infection rates were not different between the groups, while stomal granulation was significantly less in the COVID-19 group (P = 0.04). Conclusions: These results suggest that cricotracheostomy is a safe procedure in patients with severe COVID-19.

Laryngeal complications after endotracheal intubation and prone positioning in patients with coronavirus disease 2019.

Objectives: Laryngeal complications have been reported after endotracheal intubation and prone positioning in patients with critical coronavirus disease 2019 (COVID-19), but their association is unclear. In this study, we investigated the rate of laryngeal complications in patients with COVID-19 compared to an alternative condition (control group). Methods: We retrospectively analyzed the data of 40 patients who underwent endotracheal intubation for either COVID-19 or an alternative condition (control group). Data on age, sex, body mass index (BMI), cardiovascular disease (CVD) risk factors, use of prone therapy, duration of endotracheal intubation, and duration from extubation/tracheostomy to laryngeal evaluation were collected from medical records. Results: There were no significant differences in BMI, frequency of CVD risk factors, duration of endotracheal intubation, or duration from extubation/tracheostomy to laryngeal evaluation between the two groups. In the COVID-19 group, all patients adopted the prone position. In comparison, only one patient in the control group adopted the prone position. Significant differences were observed between the two groups regarding the incidence of vocal fold immobility and laryngeal granuloma. Conclusion: Laryngeal complications were more common in the COVID-19 group than in the control group. Prone positioning may be a risk factor for these complications. Level of Evidence: 4.

Effect of hormonal therapy on the otoconial changes caused by estrogen deficiency.

Benign paroxysmal positional vertigo (BPPV) is associated with menopause and/or osteopenia. Morphological changes in the otoconial layer have been reported after ovariectomy (OVX). Moreover, hormone replacement therapy decreases BPPV risk. However, knowledge concerning the effect of hormonal therapy on the otoconial changes caused by estrogen deficiency is limited. We aimed to examine the effect of hormonal therapy on otoconial changes caused by estrogen deficiency. We hypothesized that hormonal therapy could reduce otoconial changes caused by OVX. Eight-week-old C57BL/6 mice were divided into four groups: sham operation with implantation of vehicle (sham + v), OVX with implantation of vehicle (OVX + v), OVX with implantation of estradiol (E2) (OVX + E2), and OVX with implantation of raloxifene (RAL) (OVX + RAL) groups. Otoconial layer volume was measured by micro-CT at 4 weeks after OVX or the sham operation. The otic bullae were removed; immunohistochemistry was performed for estrogen receptor alpha and 4-hydroxynonenal. Otoconial layer volume was significantly higher in the OVX + v than in the sham + v group. E2 and RAL significantly reduced these changes in the endometrial layer. The staining of estrogen receptor alpha and 4-hydroxynonenal were stronger in the OVX + v than in the sham + v group but equal in the sham + v, OVX + E2, and OVX + RAL groups. These results indicate that E2 and RAL are effective against morphological changes of the otoconial layer caused by estrogen deficiency via oxidative stress reduction.

A double-blinded, randomized controlled clinical trial of hydrogen inhalation therapy for idiopathic sudden sensorineural hearing loss.

Background: Hydrogen (H2) has been reported to be effective in reducing hearing loss due to several causes in animal studies. However, no study has examined the effectiveness of H2 in treating hearing loss in humans. Thus, we investigated whether H2 is effective for the treatment of idiopathic sudden sensorineural hearing loss (ISSNHL). Materials and methods: We conducted a double-blind randomized controlled trial at six hospitals between June 2019 and March 2022. The study protocol and trial registration have been published in the Japan Registry of Clinical Trials (jRCT, No. jRCTs06119004). We randomly assigned patients with ISSNHL to receive either H2 (H2 group) or air as a placebo (control group) through inhalation combined with the administration of systemic glucocorticoids and prostaglandin E1. The primary outcome was the hearing threshold and changes in hearing threshold 3 months after therapy. In contrast, the secondary outcomes included the proportion of patients with a good prognosis (complete recovery or marked improvement). Results: Sixty-five patients with ISSNHL (31 and 34 in the H2 and control groups, respectively) were included in this study. The hearing threshold 3 months after treatment was not significantly different between the groups; 39.0 decibels (dB) (95% confidence interval [CI]: 28.7-49.3) and 49.5 dB (95% CI: 40.3-58.7) in the H2 and control groups, respectively. In contrast, the changes in hearing threshold 3 months after treatment was 32.7 dB (95% CI: 24.2-41.3) and 24.2 dB (95% CI: 18.1-30.3) in the H2 and control groups, respectively. Consequently, the changes in hearing threshold were significantly better in the H2 group than in the control group (P = 0.048). However, no adverse effects due to the inhalation of H2 gas have been reported. Conclusion: This is the first study to investigate the efficacy of H2 for the treatment of ISSNHL in humans. The results suggest that H2 therapy may be effective for ISSNHL treatment. Clinical trial registration: [https://jrct.niph.go.jp/re/reports/detail/10442], identifier [jRCTs06119004].

Generation of DNA-aptamers targeting galectin-7 for the identification of cholesteatoma residue.

PURPOSE: Aiming at complete excision of cholesteatoma during trympanomastoidectomy and therefore reducing the risk of recurrence, intraoperative imaging techniques are required to assist the visualization of cholesteatoma residue. Galectin-7 has been demonstrated to be a biomarker for cholesteatoma matrix and used for intraoperatively identifying the excision margins. METHODS: A galectin-7-targeted DNA-aptamer library was generated for labeling the cholesteatoma matrix using cell-systematic evolution of ligands by an exponential enrichment technique. The binding characteristics of the identified aptamers were analyzed, and structure optimization of the identified aptamers was carried out both in silico and in vitro. FINDINGS: A fluorophore-labeled structure-optimized DNA fragment was commercially synthesized as a non-invasive aptamer-based probe for intraoperative lesion detection. Using galectin-7-aptamer-guided molecular imaging, the excision margins of cholesteatoma matrix and surrounding normal tissue were successfully achieved within 15-20 min. CONCLUSIONS: Galectin-7-targeted aptamers could benefit molecular imaging-guided surgical treatment, which would enable clinicians to not only intraoperatively detect the locations of cholesteatoma matrix in the middle ear, but also assess the postoperative response of the expression profile to therapy. It is highly expected that further efforts for rational design and development should be directed towards the development of clinically translatable aptamer-based imaging agents.

Simultaneous combined endoscopic endonasal and transcranial surgery for giant pituitary adenomas: Tips and traps in operative indication and procedure.

OBJECTIVES: This retrospective analysis of patients treated with endoscopic endonasal transsphenoidal surgery (ETSS) alone or simultaneous combined surgery investigated imaging features suitable for surgical methods and pitfalls in simultaneous combined surgery for giant pituitary adenoma. PATIENTS AND METHODS: Ten patients with giant pituitary adenoma treated by ETSS alone or simultaneous combined endoscopic endonasal and transcranial surgery were enrolled. By analyzing tumor imaging features on magnetic resonance imaging (MRI), operative findings and clinical outcomes, we examined types of imaging features suitable for each surgical method. RESULTS: Four patients received ETSS alone and six patients underwent simultaneous combined endonasal and transcranial surgery. Four patients treated by ETSS alone and three patients treated by combined surgery had high resection rates and good outcomes. The remaining three patients with combined surgery achieved partial resection and visual deterioration in one patient. MRI features suitable for ETSS included an enlarged sella, upward tumor extension, and round surface, whereas those for combined surgery included normal/enlarged sella, anterior and/or unilateral tumor extension, and a multilobulated surface. Tumors extending extensively bilaterally or upward and encasing neurovascular structures could not be effectively resected even under combined surgery. CONCLUSION: Both ETSS alone and simultaneous combined endonasal and transcranial surgery showed good results for giant pituitary adenoma when the surgical methods matched suitable imaging features. Tumors with unilateral or anterior extension and a multilobulated surface were maximally resected without neurological deficit by combined surgery, but tumors showing extensive multi-directional extension and full encasement of neurovascular structures were not effectively resected even with combined surgery.

Imaging characteristics of hypertrophic pachymeningitis due to ANCA-associated vasculitis.

OBJECTIVE: Hypertrophic pachymeningitis (HP) is a rare disorder that causes localized or diffuse inflammatory fibrosis and thickening of the dura mater. Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV)-related HP is the most frequent form of HP. Otitis media with AAV (OMAAV) patients with HP are associated with higher rates of both ANCA-negative phenotypes and disease-related mortality. However, few studies have reported the imaging characteristics of HP due to AAV/OMAAV. Therefore, we investigated this issue in the present study. METHODS: This retrospective study included patients diagnosed with HP between 2011 and 2020 at our hospital. Age, sex, causative disease, serum C-reactive protein (CRP) level, and MRI data were collected from medical records. We compared the locations of MRI enhancement depending on the causative diseases. RESULTS: Of the 18 included patients with HP (mean age, 64.1 ± 2.6 years; range, 33-77 years), 10 (55.6%) were female, 12 (66.7%) were diagnosed with AAV/OMAAV, four (22.2%) were diagnosed as idiopathic, two (11.1%) were diagnosed with invasive Aspergillus mastoiditis. Eleven (61.1%) had cranial neuropathies. Facial nerve paralysis was common in AAV/OMAAV, while abducent nerve paralysis was common in idiopathic HP. Cranial fossa enhancement was most common presentation in patients with HP, whereas inner acoustic canal (IAC) enhancement was seen only in patients with AAV/OMAAV, while HP involving the cavernous sinus was seen only in patients with idiopathic and mastoiditis. CONCLUSION: HP involving the IAC may be a key factor in diagnosing AAV/OMAAV.

Comparison of the Signal Intensity of Vestibular Schwannoma Between Growing and Nongrowing Tumors.

OBJECTIVES/HYPOTHESIS: To determine the relationship between signal intensity on gadolinium (Gd)-enhanced magnetic resonance images and growth of vestibular schwannomas (VSs). STUDY DESIGN: Cross-sectional study. METHODS: In this cross-sectional study, we retrospectively reviewed the data of 31 patients with VSs who underwent magnetic resonance imaging (MRI). The mean signal intensities within the regions of interest in the tumor, pons, and temporal muscles were measured on Gd-enhanced T1-weighted MRI. Relative intensity ratios were calculated as follows: T/N pons ratio (T/Np) is the tumor signal intensity/pons signal intensity and T/N muscle ratio (T/Nm) is the tumor signal intensity/temporal muscle signal intensity. Volume measurements were used to assess the tumor size. Growth rate was determined by assessing previous imaging studies. Growing VS was defined as a tumor with a growth rate >100 mm3 /year. RESULTS: The mean (standard deviation) T/Np and T/Nm were 1.47 (0.27) and 1.50 (0.24), respectively, in nongrowing tumors and 1.78 (0.17) and 1.90 (0.12), respectively, in growing tumors. The T/Np and T/Nm differed significantly between the two groups (T/Np, P < .001; T/Nm, P < .001). Receiver operating characteristic curve analysis showed that cutoffs of 1.56 and 1.76 for T/Np (93.33% sensitivity, 75.00% specificity) and T/Nm (100.00% sensitivity, 93.75% specificity), respectively, could be used to diagnose a growth rate of >100 mm3 /year. The area under the curve was 0.85 (95% confidence interval, 0.70-1.00) for T/Np and 0.94 (0.82-1.00) for T/Nm. CONCLUSION: Growing VSs show higher signal intensities on Gd-enhanced MRI. Thus, measuring the signal intensity of VS on Gd-enhanced MRI may aid in predicting VS growth. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:198-203, 2022.

Exteriorization of Petrous Bone Cholesteatoma by Endonasal Endoscopic Approach: A Case Report.

A 61-year-old woman presented with diplopia and headache. The patient had a longstanding history of petrous bone cholesteatoma (PBC) on the left side and had undergone multiple surgeries to address it. Computed tomography (CT) revealed a radiolucent lesion with bony destruction in the left petrous apex. Magnetic resonance imaging of the lesion revealed a hypointense area on T1-weighted images and a hyperintense area on T2-weighted and abnormal diffusion-weighted images. A diagnosis of recurrent petrous apex cholesteatoma was made. The patient was treated by exteriorization using an endoscopic endonasal approach. The patient is in remission and doing well. The ideal treatment of PBC is complete excision, though exteriorization using an endoscopic endonasal approach is considered a second option when excision is not possible.

Association of the prognosis and severity of idiopathic sudden sensorineural hearing loss with cervical ultrasonographic findings.

OBJECTIVE: The aim of this study was to investigate the association of the prognosis and severity of idiopathic sudden sensorineural hearing loss (ISSNHL) with cervical ultrasonographic findings suggestive of cardiovascular risk. METHODS: Seventy-four inpatients with ISSNHL were included in our study. Cervical ultrasonography was performed to evaluate the common carotid artery (CCA), internal carotid artery (ICA), and vertebral artery (VA). The peak systolic velocity, end diastolic velocity, intima-media thickness, pulsatility index (PI), and resistance index (RI) were evaluated. We investigated the relationship of these variables with the severity and prognosis of ISSNHL. RESULTS: ICA-PI, ICA-RI, and CCA-RI were significantly higher in patients with poor hearing prognosis than in those with good prognosis. The variables of VA were not related to the prognosis of ISSNHL. There were no statistically significant differences between ISSNHL severity and cervical ultrasonographic findings. CONCLUSIONS: We found that PI and RI might be prognostic factors for ISSNHL.

The association between ear involvement and clinical features and prognosis in ANCA-associated vasculitis.

OBJECTIVE: The concept of otitis media with ANCA-associated vasculitis (OMAAV) was recently proposed by the study group of the Japan Otological Society. However, little is known about the effect of ear involvement on the clinical features and prognosis of AAV. We investigate this issue in this study. METHODS: We retrospectively examined 36 patients diagnosed with OMAAV and 44 patients diagnosed with AAV without ear involvement (non-OMAAV) at Ehime University Hospital from 2013 to 2018. We collected serological findings including ANCA type and titer, C-reactive protein (CRP), serum creatinine level, organ involved at initial diagnosis, treatment, remission, disease relapse, and mortality from medical records. We investigated whether clinical features and outcomes differed between the OMAAV and non-OMAAV groups. RESULTS: Age, ANCA titer, and CRP at initial diagnosis were not significantly different between the two groups, and the rate of intravenous cyclophosphamide (IVCY) use also did not differ. The proportions of patients with concurrent eye involvement, facial palsy (FP), and hypertrophic pachymeningitis (HCP) were significantly higher in the OMAAV than in the non-OMAAV group (p = 0.005, 0.005 and 0.049, respectively), while both renal and peripheral nerve involvement were significantly less common in OMAAV patients (p = 0.04). Among the 30 patients with renal involvement, serum creatinine level at diagnosis was significantly lower in the OMAAV group (p = 0.04). The mortality rate was 8.3% in OMAAV and 6.8% in non-OMAAV cases, but this difference was not significant. The rate of relapse was 33.3% in OMAAV and 13.6% in non-OMAAV cases; this difference was significant (p = 0.04). CONCLUSIONS: Serological measurements of disease activity did not differ between the groups. Eye involvement, FP, and HCP, however, were significantly more common in AAV with ear involvement. In addition, renal involvement was less common and renal impairment was milder in AAV with ear involvement. These findings can be considered clinical features. The relapse rate was significantly higher in AAV with ear involvement.

Intravenous administration of bone marrow mononuclear cells alleviates hearing loss after transient cochlear ischemia through paracrine effects.

Bone marrow mononuclear cells (BMMCs) are known to enhance recovery from ischemic insults by secreting angiogenic factors and inducing the expression of angiogenic factors from host tissues. Therefore, the transplantation of BMMCs is considered a potential approach to promoting the repair of ischemic damaged organs. Here, we investigated the influence of BMMCs on progressive hair cell degeneration after transient cochlear ischemia in gerbils. Transient cochlear ischemia was produced by extracranial occlusion of the bilateral vertebral arteries immediately before their entry into the transverse foramen of the cervical vertebra. An intravenous injection of BMMCs prevented ischemia-induced hair cell degeneration and ameliorated hearing impairment. A tracking study showed that BMMCs injected into the femoral vein were limited in the spiral artery of the cochlea, suggesting that, although transplanted BMMCs were retained within the spiral ganglion area of the cochlea, they were neither transdifferentiated into cochlear cells nor fused with the injured hair cells and supporting cells in the organ of Corti to restore their functions. We also showed that the protein level of neurotrophin-3 and glial cell line-derived neurotrophic factor in the organ of Corti was upregulated after treatment with BMMCs. These results suggested that BMMCs have therapeutic potential possibly through paracrine effects. Thus, we propose the use of BMMCs as a potential new therapeutic strategy for hearing loss.

Clinical features, presenting symptoms, and surgical results of congenital cholesteatoma based on Potsic's staging system.

CONCLUSIONS: Potsic's staging system is a clinically useful procedure for evaluating the extent of congenital cholesteatoma (CC). OBJECTIVES: We investigated the clinical features, presenting symptoms, and surgical results of CC according to Potsic's staging system. METHODS: A total of 71 patients who had undergone surgery at our hospital were retrospectively analyzed for presenting symptoms, the location of cholesteatoma, and surgical results according to Potsic's staging system. RESULTS: Of the 71 patients, 21 were classified as Potsic stage I, 9 as stage II, 31 as stage III, and 10 as stage IV. More than half of the patients with early-stage CC (stages I and II) were diagnosed asymptomatically by a chance visit to a clinic or on ear screening. Others were diagnosed following a complaint of hearing loss, acute otitis media, or otitis media with effusion. The location of CC varied somewhat by stage. In stage I CC, the most frequent location was behind the anterior-superior quadrant of the tympanic membrane; however, in stage III CC, it was behind the posterior-superior quadrant. All patients were treated surgically. Recurrence was detected in 2 of the 71 patients (2.8%); both had stage II CC. Recurrent lesions were removed during revision surgery.

Air-bone gap in ears with a well-repaired tympanic membrane after Type III and Type IV tympanoplasty.

OBJECTIVE: To investigate the air-bone conduction hearing gap (A-B gap) after Type III and Type IV stapes columella tympanoplasty in ears with mobile stapes and a well repaired tympanic membrane (TM). METHODS: Those patients who underwent tympanoplasty in our hospital between 2003 and 2009 and satisfied the following criteria were eligible: (1) good stapes mobility, confirmed intraoperatively; (2) postoperative TM and/or computed tomography (CT) findings that showed a well-aerated tympanic cavity without TM perforation, otorrhea, or middle ear effusion; and (3) measurable air and bone conduction hearing thresholds 1 year postoperatively at all test frequencies (250 Hz, 500 Hz, 1 kHz, 2 kHz, and 4 kHz). RESULTS: Hearing results were better after Type III tympanoplasty than after Type IV tympanoplasty. After Type III (n=70) and Type IV (n=24) tympanoplasty, the respective mean A-B gaps were 16.4 ± 7.2 dB and 20.1 ± 5.6 dB, respectively. The mean A-B gap was significantly smaller after Type III tympanoplasty than after Type IV tympanoplasty (p<0.05). Regardless of the type of tympanoplasty, the postoperative A-B gap was greatest at 4 kHz. CONCLUSION: The mean A-B gap was smaller after Type III tympanoplasty than after Type IV tympanoplasty. The magnitude of the A-B gap was greatest at 4 kHz in both procedures.

Infantile inflammatory pseudotumor of the facial nerve as a complication of epidermal nevus syndrome with cholesteatoma.

The first reported case of facial paralysis due to an inflammatory pseudotumor (IPT) of the facial nerve as a complication of epidermal nevus syndrome (ENS) is herein presented. A 10-month-old female patient was diagnosed with ENS at 3 months of age. She was referred to us because of moderate left facial paralysis. Epidermal nevi of her left auricle extended deep into the external ear canal. Otoscopy revealed polypous nevi and cholesteatoma debris filling the left ear. Computed tomography showed a soft mass filling the ear canal, including the middle ear, and an enormously enlarged facial nerve. Surgical exploration revealed numerous polypous nevi, external ear cholesteatoma, and tumorous swelling of the facial nerve. The middle ear ossicles were completely lost. The facial paralysis was improved after decompression surgery, but recurred 5 months later. A second operation was conducted 10 months after the first. During this operation, facial nerve decompression was completed from the geniculate ganglion to near the stylomastoid foramen. Histological diagnosis of the facial nerve tumor was IPT probably caused by chronic external ear inflammation induced by epidermal nevi. The facial paralysis gradually improved to House-Blackmann grade III 5 years after the second operation.

The leaf-order-dependent enhancement of freezing tolerance in cold-acclimated Arabidopsis rosettes is not correlated with the transcript levels of the cold-inducible transcription factors of CBF/DREB1.

The central part of cold-acclimated rosettes of Arabidopsis thaliana L. (ecotype Columbia) survived freezing at lower temperatures better than did those at the rosette periphery. Electrolyte-leakage tests with detached leaves verified that freezing tolerance in central (or young) leaves increased faster and to a greater extent than in peripheral (or aged and mature) leaves at 2 degrees C. Cold-induced accumulation of sugars could partly account for the leaf-order-dependent enhancement of freezing tolerance after 1 d at 2 degrees C, whereas the role of proline remains to be determined. Cold-induced accumulation of the transcripts of stress-inducible CBF/DREB1 transcription factors apparently disagreed with the observed difference in the freezing tolerance in different leaf orders. However, the levels of COR78/RD29A transcripts were almost the same between different leaf orders after 1-3 d at 2 degrees C, and COR78/RD29A content per total leaf protein was similar between different leaf orders after 7 d at 2 degrees C. Thus, cold-induced accumulation of COR78/RD29A does not seem to account for the observed difference in freezing tolerance in different leaf orders. Although further studies are required for comprehensive understanding of the phenomenon, the present work does provide an important and interesting physiological aspect in our understanding of the freezing tolerance in plants.