Tumor shape as a prognostic factor for the growth of intracanalicular vestibular schwannoma: a long-term observational study.

PURPOSE: To evaluate the predictive factors of tumor growth in patients with vestibular schwannoma (VS) managed with the wait-and-scan approach. METHODS: The data of 31 patients diagnosed with intracanalicular VS and followed for > 5 years were retrospectively analyzed. VS was diagnosed according to MRI findings and tumor growth was monitored. Tumor growth was defined as an increase of 2 mm or more in the maximal tumor diameter. The association between the initial tumor size and shape and tumor growth was assessed. RESULTS: Tumor growth was observed in 16 of 31 patients (51.6%) over a mean follow-up duration of 7.3 years. The initial tumor size was not statistically correlated with tumor growth. However, fusiform or cylindrical tumors exhibited higher growth rates than oval or round tumors. Additionally, a significant correlation was observed between cerebellopontine angle extension and tumor shape. CONCLUSION: In this study, 51.6% of the patients with intracanalicular VS who were managed with the wait-and-scan strategy over a follow-up period of > 5 years showed tumor growth. Tumor shape, especially fusiform or cylindrical shape, was found to be a significant predictor of tumor growth.

Clinical characteristics of persistent postural-perceptual dizziness and its visual subtype in Korean patients: A multicenter cross-sectional study.

OBJECTIVES: Persistent postural-perceptual dizziness (PPPD) is a chronic functional vestibular disorder for which the Bárány Society has established diagnostic criteria. This nationwide multicenter study aims to investigate the clinical features of individuals with definite PPPD and clinical variant PPPD who do not fully meet the diagnostic criteria, with a particular focus on visual exaggeration. METHODS: Between September 2020 and September 2021, a total of 76 individuals with definite PPPD and 109 individuals with clinical variant PPPD who did not meet all three exacerbating factors outlined in Criterion B were recruited from 18 medical centers in South Korea. The study gathered information on demographic factors, clinical manifestations, balance scales, and personality assessments. RESULTS: Comparative analysis between groups with definite PPPD and clinical variant with visual exacerbation revealed no significant differences in sociodemographic characteristics, clinical course, dizziness impact, and specific precipitants. Only disease duration was significantly longer in definite PPPD compared with variant with visual exacerbation. However, the variant without visual exacerbation displayed significantly reduced rates of panic disorder, diminished space-motion discomfort, lesser impact of dizziness, and decreased prevalence of depression when compared with the definitive PPPD. CONCLUSION: This is the first comprehensive nationwide study examining clinical features of both definite PPPD patients and its clinical variants, considering visual exacerbating factors. Differences in dizziness and personality traits emerged between definite PPPD and its potential variant without visual issues. Our results highlight the possibility of a distinct clinical variant of PPPD influenced by visual dependency.

Monthly Variation in Bell's Palsy Based on Population Data of Korea.

INTRODUCTION: Several studies have reported that the number of patients with Bell's palsy varied significantly by month and season. However, few studies have reported the monthly variation in Bell's palsy based on the whole population. We investigated the monthly variation in Bell's palsy in Korea during a long-term period based on whole population data. METHODS: This retrospective study used the data of the National Health Insurance Service of Korea, which included the entire Korean population from 2008 to 2020. The monthly incidence of Bell's palsy per 100,000 was evaluated in total and according to sex, age, and residence. RESULTS: The total average monthly incidence differed significantly by month, with the highest observed in January (9.1 per 100,000) and the lowest in June (7.7 per 100,000) (p < 0.001). The average monthly incidence according to sex, age, and residence also varied significantly by month, with most of the highest values noted in January and the lowest in June. CONCLUSION: There was significant monthly variation in the incidence of Bell's palsy, with the highest in January during the winter and the lowest in June during the summer, based on whole population data over a long-term period in Korea.

Evaluation of porcine intestinal organoids as an in vitro model for mammalian orthoreovirus 3 infection.

BACKGROUND: Mammalian orthoreovirus type 3 (MRV3), which is responsible for gastroenteritis in many mammalian species including pigs, has been isolated from piglets with severe diarrhea. However, the use of pig-derived cells as an infection model for swine-MRV3 has rarely been studied. OBJECTIVES: This study aims to establish porcine intestinal organoids (PIOs) and examine their susceptibility as an in vitro model for intestinal MRV3 infection. METHODS: PIOs were isolated and established from the jejunum of a miniature pig. Established PIOs were characterized using polymerase chain reaction (PCR) and immunofluorescence assays (IFAs) to confirm the expression of small intestine-specific genes and proteins, such as Lgr5, LYZI, Mucin-2, ChgA, and Villin. The monolayered PIOs and three-dimensional (3D) PIOs, obtained through their distribution to expose the apical surface, were infected with MRV3 for 2 h, washed with Dulbecco's phosphate-buffered saline, and observed. Viral infection was confirmed using PCR and IFA. We performed quantitative real-time reverse transcription-PCR to assess changes in viral copy numbers and gene expressions linked to intestinal epithelial genes and antiviral activity. RESULTS: The established PIOs have molecular characteristics of intestinal organoids. Infected PIOs showed delayed proliferation with disruption of structures. In addition, infection with MRV3 altered the gene expression linked to intestinal epithelial cells and antiviral activity, and these effects were observed in both 2D and 3D models. Furthermore, viral copy numbers in the supernatant of both models increased in a time-dependent manner. CONCLUSIONS: We suggest that PIOs can be an in vitro model to study the infection mechanism of MRV3 in detail, facilitating pharmaceutical development.

The significance of programed cell death-ligand 1 expression in vestibular schwannoma.

BACKGROUND: The association between programed cell death-ligand 1 (PD-L1) and tumor-infiltrating lymphocytes (TILs) in vestibular schwannoma (VS) has been investigated in a few studies. These published studies report a difference in the PD-L1 positivity rate in malignant peripheral nerve sheath tumors. We examined PD-L1 expression and lymphocyte infiltration in patients with VS who had undergone surgical resection and investigated the association between PD-L1 expression and clinicopathological features. METHODS: The expression of PD-L1, CD8, and Ki-67 in 40 VS tissue specimens was investigated using immunohistochemistry, and a clinical review of the patients was performed. RESULTS: Of the 40 VS samples, 23 (57.5%) were positive for PD-L1 and 22 (55%) were positive for CD8. No significant differences in age, tumor size, pure-tone audiometry, speech discrimination, or Ki-67 expression were observed between patients in the PD-L1-positive and PD-L1-negative groups. A higher level of CD8-positive cell infiltration was observed in PD-L1-positive tumors than in PD-L1-negative tumors. CONCLUSION: We demonstrated that PD-L1 was expressed in VS tissues. Although no correlation was identified between clinical characteristics and PD-L1 expression, the association between PD-L1 and CD8 was confirmed. Thus, additional research on targeting PD-L1 is necessary to improve immunotherapy for VS in the future.

Association of Hearing Loss With Anatomical and Functional Connectivity in Patients With Mild Cognitive Impairment.

Importance: Hearing loss is the most important modifiable risk factor for cognitive impairment; however, the association of hearing loss with anatomical and functional connectivity is not fully understood. This association may be elucidated by evaluating the findings of newer imaging technologies. Objectives: To evaluate the association of hearing loss with anatomical and functional connectivity in patients with mild cognitive impairment (MCI) by using multimodal imaging technology. Design, Setting, and Participants: This was a prospective cross-sectional study of patients with MCI under the care of a neurology clinic at the Soonchunhyang University Bucheon Hospital (Republic of Korea) from April to September 2021. Data were analyzed from April 1 to June 30, 2022. Main Outcomes and Measures: Pure tone averages (PTA) and word recognition scores were used to measure hearing acuity. Magnetic resonance imaging (MRI) and positron emission tomography scans of the brain were used to assess functional and anatomical connectivity. Results of diffusion MRI, voxel- and surface-based morphometric imaging, and global brain amyloid standardized uptake ratio were analyzed. Neuroimaging parameters of patients with MCI plus hearing loss were compared with those of patients with MCI and no hearing loss. Correlation analyses among neuroimaging parameters, PTA, and word recognition scores were performed. Results: Of 48 patients with MCI, 30 (62.5%) had hearing loss (PTA >25 dB) and 18 (37.5%) did not (PTA ≤25 dB). Median (IQR) age was 73.5 (69.0-78.0) years in the group with hearing loss and 75.0 (65.0-78.0) years in the group with normal hearing; there were 20 (66.7%) and 14 (77.8%) women in each group, respectively. The group with MCI plus hearing loss demonstrated decreased functional connectivity between the bilateral insular and anterior divisions of the cingulate cortex, and decreased fractional anisotropy in the bilateral fornix, corpus callosum forceps major and tapetum, left parahippocampal cingulum, and left superior thalamic radiation. Fractional anisotropy in the corpus callosum forceps major and bilateral parahippocampal cingulum negatively correlated with the severity of hearing loss shown by PTA testing. The 2 groups were not significantly different in global ß-amyloid uptake, gray matter volume, and cortical thickness. Conclusion and Relevance: The findings of this prospective cross-sectional study suggest that alterations in the salience network may contribute to the neural basis of cognitive impairment associated with hearing loss in patients who are on the Alzheimer disease continuum.

Development and Validation of a Food Frequency Questionnaire for Evaluating the Nutritional Status of Patients with Cancer.

Patients with cancer need to maintain proper nutritional status to overcome cancer, alleviate the side effects of chemotherapy, and prevent a recurrence. As such, it is necessary to manage nutritional status. This study aimed to develop a dish-based semi-quantitative food frequency questionnaire (FFQ) to evaluate the nutritional status of patients with cancer and assess the validity of the FFQ. A total of 109 dish items were selected through contribution and variability analyses using the 2016-2018 Korea National Health and Nutrition Examination Survey data. The FFQ was validated against the average 3-day dietary records of 100 patients with cancer. Pearson correlation coefficients and quartile agreements between FFQ and 3-day dietary records were calculated for intake of energy, macronutrients, and micronutrients. Age and energy-adjusted Pearson correlation coefficients ranged from 0.20 (iron) to 0.54 (potassium). The percentage of participants who were classified into the same or adjacent quartile between the FFQ and the 3-day dietary record ranged from 68% (protein) to 81% (energy, dietary fiber). The results suggest that the FFQ is an appropriate tool for assessing nutritional status in Korean cancer patients.

Effects of Ginger Intake on Chemotherapy-Induced Nausea and Vomiting: A Systematic Review of Randomized Clinical Trials.

Nausea and vomiting are the most common side effects of chemotherapy. They must be managed because they can increase the risk of malnutrition in patients, which can adversely affect treatment. The objective of this study was to evaluate the effect of ginger supplementation as an adjuvant treatment for alleviating chemo We checked. therapy-induced nausea and vomiting (CINV). This study searched for randomized controlled trials (RCTs) related to ginger supplement intake for CINV in three electronic databases (i.e., Medline (PubMed), Embase, and Web of Science). The search period ranged from each database's first date of service to 5 November 2021. Two investigators independently performed abstract screenings, full-text screenings, data extraction, and risk of bias analyses (ROB). The Cochrane ROB tool was used for the assessment of ROB. This study systematically reviewed 23 RCTs. The effects of ginger supplementation were compared to those of placebo or antiemetic agents. This study conducted a meta-analysis after classifying the effects of ginger supplementation on acute and delayed CINV into subgroups due to the clinical heterogeneity between these RCTs. The results showed that the incidence of acute nausea (p = 0.53), the incidence of delayed nausea (p = 0.31), the incidence of acute vomiting (p = 0.09), and the incidence of delayed vomiting (p = 0.89) were not significantly different between the ginger supplement intake group and the control group. However, it was found that the ginger supplement intake group, which took not more than 1 g of ginger supplementation per day for above four days, had significantly less acute vomiting than the control group (OR 0.30; 95% CI 0.12 to 0.79; p = 0.02; I2 = 36%). Ginger supplementation may reduce the incidence of acute chemotherapy-induced vomiting. However, this study could not confirm the effects of ginger supplementation on the incidence of chemotherapy-induced nausea and delayed vomiting. Therefore, it will be necessary to conduct additional studies with sufficient sample sizes using high-quality RCTs to evaluate the effects of ginger supplementations based on the results of this study.

Creutzfeldt-Jakob disease presenting with bilateral hearing loss: A case report.

BACKGROUND: Sporadic Creutzfeldt-Jakob disease (sCJD) is a prion disease characterized as a fatal transmissible neurodegenerative disorder. Dizziness is often the first presenting symptom of sCJD, but hearing loss as an early manifestation is very rare. CASE SUMMARY: A 76-year-old man presented with bilateral sudden hearing impairment and dizziness for 10 d. He was taking medications for hypertension and diabetes. He denied any difficulty with activities of daily living or hearing impairment before the onset of symptoms. Pure tone audiometry showed bilateral severe hearing impairment. Brain magnetic resonance imaging (MRI) and laboratory tests were within normal limits. Given his diagnosis of sudden sensory hearing loss, the patient received corticosteroid treatment but it was ineffective. Two weeks later, he complained of aggravated gait impairment, disorientation, and cognitive impairment. Repeat brain MRI showed diffuse cortical high signal intensities on diffusion-weighted imaging. In cerebrospinal fluid analysis, the real-time quaking-induced conversion assay was positive, and 14-3-3 protein was detected in the by western blotting. Considering all the data, we diagnosed probable sCJD, and the patient's symptoms rapidly progressed into akinetic mutism. CONCLUSION: For patients with abrupt bilateral hearing impairment, especially in the elderly, various differential diagnoses, including sCJD, should be considered.

Efficacy of steroid treatment for sudden sensorineural hearing loss in patients with vestibular schwannoma.

BACKGROUND: Sudden sensorineural hearing loss (SSNHL) has several aetiologies and may be a presenting symptom of vestibular schwannoma (VS). OBJECTIVES: The aim of this study was to investigate the recovery rate after steroid treatment and the prognostic factors of SSNHL with VS. MATERIALS AND METHODS: This was a retrospective observational study wherein 32 patients with VS who presented with SSNHL were analysed at a tertiary referral centre. Hearing gain and prognostic factors were the main outcome measures for steroid treatment intervention. RESULTS: Among the 1698 patients presenting with SSNHL, VS was found in 43 (2.5%) patients. Eleven cases (34.3%) showed good recovery, with significant improvements in the pure-tone audiometry values. Even though age was a significant factor, there were no associations between steroid response and initial hearing level, presence of vertigo, tumour size, and tumour extension. CONCLUSIONS AND SIGNIFICANCE: Our study showed that hearing recovery of SSNHL does not exclude a VS diagnosis. We suggest that steroid treatment be considered in patients with VS presenting SSNHL.

Celastrol suppresses the growth of vestibular schwannoma in mice by promoting the degradation of ß-catenin.

Vestibular schwannoma (VS), one of characteristic tumors of neurofibromatosis type 2 (NF2), is an intracranial tumor that arises from Schwann cells of the vestibular nerve. VS results in hearing loss, tinnitus, dizziness, and even death, but there are currently no FDA-approved drugs for treatment. In this study, we established a high-throughput screening to discover effective compounds that could inhibit the viability of VS cells. Among 1019 natural products from the Korea Chemical Bank screened, we found that celastrol, a pentacyclic triterpene derived from a Tripterygium Wilfordi plant, exerted potent inhibitory effect on the viability of VS cells with an IC50 value of 0.5 µM. Celastrol (0.5, 1 µM) dose-dependently inhibited the proliferation of primary VS cells derived from VS patients. Celastrol also inhibited the growth, and induced apoptosis of two other VS cell lines (HEI-193 and SC4). Aberrant activation of Wnt/ß-catenin signaling has been found in VS isolated from clinically defined NF2 patients. In HEI-193 and SC4 cells, we demonstrated that celastrol (0.1, 0.5 µM) dose-dependently inhibited TOPFlash reporter activity and protein expression of ß-catenin, but not mRNA level of ß-catenin. Furthermore, celastrol accelerated the degradation of ß-catenin by promoting the formation of the ß-catenin destruction complex. In nude mice bearing VS cell line SC4 allografts, administration of celastrol (1.25 mg · kg-1 · d-1, i.p. once every 3 days for 2 weeks) significantly suppressed the tumor growth without showing toxicity. Collectively, this study demonstrates that celastrol can inhibit Wnt/ß-catenin signaling by promoting the degradation of ß-catenin, consequently inhibiting the growth of VS.

Endoscopic Transcanal Labyrinthectomy for Intractable Meniere's Disease: An Alternative to Transmastoid Labyrinthectomy?

OBJECTIVE: To describe a novel approach for intractable Ménière's disease exclusively through a transcanal endoscopic ear surgery (TEES) approach. PATIENT: A 56-year-old male with intractable Ménière's disease despite conservative treatment and chemical labyrinthectomy. INTERVENTIONS: Transcanal endoscopic labyrinthectomy. MAIN OUTCOME MEASURE: Subjective vertigo control, surgical morbidity. RESULTS: The TEES approach provided a wide exposure of the oval window. This facilitated removal of stapes crura and footplate. After widening of the oval window, the perilymph was suctioned, and gentamicin was injected through the oval window. The oval window was obliterated using the perichondrium of the tragal cartilage and fibrin glue. After 2 years of follow-up, there was no recurrence of vertigo. CONCLUSIONS: As a compelling alternative to the transmastoid approach, we propose endoscopic labyrinthectomy as an option for patients with intractable MD without functional hearing who have failed chemical labyrinthectomy. Additional studies are needed to determine the risk-benefit profile of this technique.

Differential Biases and Variabilities of Deep Learning-Based Artificial Intelligence and Human Experts in Clinical Diagnosis: Retrospective Cohort and Survey Study.

BACKGROUND: Deep learning (DL)-based artificial intelligence may have different diagnostic characteristics than human experts in medical diagnosis. As a data-driven knowledge system, heterogeneous population incidence in the clinical world is considered to cause more bias to DL than clinicians. Conversely, by experiencing limited numbers of cases, human experts may exhibit large interindividual variability. Thus, understanding how the 2 groups classify given data differently is an essential step for the cooperative usage of DL in clinical application. OBJECTIVE: This study aimed to evaluate and compare the differential effects of clinical experience in otoendoscopic image diagnosis in both computers and physicians exemplified by the class imbalance problem and guide clinicians when utilizing decision support systems. METHODS: We used digital otoendoscopic images of patients who visited the outpatient clinic in the Department of Otorhinolaryngology at Severance Hospital, Seoul, South Korea, from January 2013 to June 2019, for a total of 22,707 otoendoscopic images. We excluded similar images, and 7500 otoendoscopic images were selected for labeling. We built a DL-based image classification model to classify the given image into 6 disease categories. Two test sets of 300 images were populated: balanced and imbalanced test sets. We included 14 clinicians (otolaryngologists and nonotolaryngology specialists including general practitioners) and 13 DL-based models. We used accuracy (overall and per-class) and kappa statistics to compare the results of individual physicians and the ML models. RESULTS: Our ML models had consistently high accuracies (balanced test set: mean 77.14%, SD 1.83%; imbalanced test set: mean 82.03%, SD 3.06%), equivalent to those of otolaryngologists (balanced: mean 71.17%, SD 3.37%; imbalanced: mean 72.84%, SD 6.41%) and far better than those of nonotolaryngologists (balanced: mean 45.63%, SD 7.89%; imbalanced: mean 44.08%, SD 15.83%). However, ML models suffered from class imbalance problems (balanced test set: mean 77.14%, SD 1.83%; imbalanced test set: mean 82.03%, SD 3.06%). This was mitigated by data augmentation, particularly for low incidence classes, but rare disease classes still had low per-class accuracies. Human physicians, despite being less affected by prevalence, showed high interphysician variability (ML models: kappa=0.83, SD 0.02; otolaryngologists: kappa=0.60, SD 0.07). CONCLUSIONS: Even though ML models deliver excellent performance in classifying ear disease, physicians and ML models have their own strengths. ML models have consistent and high accuracy while considering only the given image and show bias toward prevalence, whereas human physicians have varying performance but do not show bias toward prevalence and may also consider extra information that is not images. To deliver the best patient care in the shortage of otolaryngologists, our ML model can serve a cooperative role for clinicians with diverse expertise, as long as it is kept in mind that models consider only images and could be biased toward prevalent diseases even after data augmentation.

Novel method to repair articular cartilage by direct reprograming of prechondrogenic mesenchymal stem cells.

Age-related cartilage loss is worsened by the limited regenerative capacity of chondrocytes. The role of cell-based therapies using mesenchymal stem cells is gaining interest. Adipose tissue-derived mesenchymal stem cells (ADSCs) are an attractive source to generate the optimal number of chondrocytes required to repair a cartilage defect and regenerate hyaline articular cartilage. Here, we report an outstanding technique to prepare chondrocytes for cartilage repair using canine ADSCs. We hypothesized that external electrical fields promote prechondrogenic condensation without requiring genetic modifications or exogenous factors. We analyzed the effect of electrical stimulation (ES) on the differentiation of ADSC micromass into chondrocytes. Highly compact structures were formed within 3 days of ES of canine ADSC micromass. The expression of type I collagen gene was abolished in these cells compared with that in control micromass cultures and monolayer cultures. We further found that ES enhanced the production of proteoglycan, a highly produced extracellular matrix component in chondrocytes. Additionally, single-cell RNA sequencing analysis showed that canine ADSC micromass undergoing ES developed a prechondrogenic cell aggregation, suggesting their metabolic conversion, biogenesis, and calcium ion change. Collectively, our findings demonstrate the capacity of ES to drive the chondrogenesis of ADSCs in the absence of exogenous factors and confirm its commercial potential as a budget-friendly therapy for the repair of cartilage defects.

Canine Natural Killer Cell-Derived Exosomes Exhibit Antitumor Activity in a Mouse Model of Canine Mammary Tumor.

Natural killer (NK) cells are key immune cells engaged in fighting infection and malignant transformation. In this study, we found that canine NK cell-derived exosomes (NK-exosomes) separated from activated cytotoxic NK cell supernatants express specific markers including CD63, CD81, Alix, HSP70, TSG101, Perforin 1, and Granzyme B. We examined the antitumor effects of NK-exosomes in an experimental murine mammary tumor model using REM134 canine mammary carcinoma cell line. We observed changes in tumor size, tumor initiation, progression, and recurrence-related markers in the control, tumor group, and NK-exosome-treated tumor group. We found that the tumor size in the NK-exosome-treated tumor group decreased compared with that of the tumor group in the REM134-driven tumorigenic mouse model. We observed significant changes including the expression of tumorigenesis-related markers, such as B cell-specific Moloney murine leukemia virus insertion site 1 (Bmi-1), vascular endothelial growth factor (VEGF), matrix metallopeptidase-3 (MMP-3), interleukin-1ß (IL-1ß), IL-6, tumor necrosis factor-α (TNF-α), multidrug resistance protein (MDR), tumor suppressor protein p53 (p53), proliferating cell nuclear antigen (PCNA), and the apoptotic markers, B cell lymphoma-2 associated X (Bax) and B cell lymphoma-extra large (Bcl-xL) belonging to the Bcl-2 family, in the tumor group compared with those in the control group. The expression of CD133, a potent cancer stem cell marker, was significantly higher than that of the control. By contrast, the NK-exosome-treated tumor group exhibited a significant reduction in Bmi-1, MMP-3, IL-1ß, IL-6, TNF-α, Bax, Bcl-xL, and PCNA expression compared with that in the tumor group. Furthermore, the expression of CD133, which mediates tumorigenesis, was significantly decreased in the NK-exosome-treated tumor group compared with that in the tumor group. These findings indicate that canine NK-exosomes represent a promising therapeutic tool against canine solid tumors, including mammary carcinoma.

Automatic Facial Recognition System Assisted-facial Asymmetry Scale Using Facial Landmarks.

OBJECTIVES: This study aimed to demonstrate the application of our automated facial recognition system to measure facial nerve function and compare its effectiveness with other conventional systems and provide a preliminary evaluation of deep learning-facial grading systems. STUDY DESIGN: Retrospective, observational. SETTING: Tertiary referral center, hospital. PATIENTS: Facial photos taken from 128 patients with facial paralysis and two persons with no history of facial palsy were analyzed. INTERVENTION: Diagnostic. MAIN OUTCOME MEASURES: Correlation with Sunnybrook (SB) and House-Brackmann (HB) grading scales. RESULTS: Our results had good reliability and correlation with other grading systems (r = 0.905 and 0.783 for Sunnybrook and HB grading scales, respectively), while being less time-consuming than Sunnybrook grading scale. CONCLUSIONS: Our objective method shows good correlation with both Sunnybrook and HB grading systems. Furthermore, this system could be developed into an application for use with a variety of electronic devices, including smartphones and tablets.

A comparison of endoscopic and microscopic inlay butterfly cartilage tympanoplasties and their educational utility.

OBJECTIVES: Inlay butterfly cartilage tympanoplasty (IBCT) is a simple grafting technique. Endoscopy facilitates visualization by eliminating blind spots. We analyzed the outcomes of IBCT using both endoscopic and microscopic approaches, and assessed how trainees perceived the educational opportunities afforded. MATERIALS AND METHODS: Sixty patients who underwent IBCT were allocated to Group I (n = 30; microscopic IBCT) and Group II (n = 30; endoscopic IBCT) by the dates of their visits. Anatomical success was defined as an intact, repaired tympanic membrane; functional success was defined as a significant decrease in the air-bone gap. Postoperative discomfort was analyzed using a visual analog scale (VAS). Thirteen trainees completed structured questionnaires exploring anatomical identification and the surgical steps. RESULTS: The surgical success rates were 96.7% in Group I and 100% in Group II. We found no between-group differences in the mean decrease in the air-bone gap or the extent of postoperative discomfort. Significant postoperative hearing improvements were evident in both groups. The mean operative time was shorter when the microscopic approach was chosen (17.7±4.53 vs. 26.13±9.94 min). The two approaches significantly differed in terms of the identification of external and middle ear anatomical features by the trainees, and their understanding of the surgical steps. CONCLUSION: Both endoscopic and microscopic IBCT were associated with good success rates. The endoscopic approach facilitates visualization, and a better understanding of the middle ear anatomy and the required surgical steps and thus is of greater educational utility.

Bovine tongue epithelium-derived cells: A new source of bovine mesenchymal stem cells.

Mesenchymal stem cells (MSCs) possess the ability to differentiate into multiple cell lineages, and thus, confer great potential for use in regenerative medicine and biotechnology. In the present study, we attempted to isolate and characterize bovine tongue tissue epithelium-derived MSCs (boT-MSCs) and investigate the culture conditions required for long-term culturing of boT-MSCs. boT-MSCs were successfully isolated by the collagenase digestion method and their proliferative capacity was maintained for up to 20 or more passages. We observed a significant increase in the proliferation of boT-MSCs during the 20 consecutive passages under low-glucose Dulbecco's modified Eagle's medium culture condition among the three culture conditions. These boT-MSCs presented pluripotency markers (octamer-binding transcription factor 3/4 (Oct3/4) and sex determining region Y-box2 (Sox2)) and cell surface markers, which included CD13, CD29, CD44, CD73, CD90, CD105, CD166, and major histocompatibility complex (MHC) class I (MHC-I) but not CD11b, CD14, CD31, CD34, CD45, CD80, CD86, CD106, CD117, and MHC-II at third passage. Moreover, these boT-MSCs could differentiate into mesodermal (adipocyte, osteocyte, and chondrocyte) cell lineages. Thus, the present study suggests that the tongue of bovines could be used as a source of bovine MSCs.