E2F regulation of the Phosphoglycerate kinase gene is functionally important in Drosophila development.

The canonical role of the transcription factor E2F is to control the expression of cell cycle genes by binding to the E2F sites in their promoters. However, the list of putative E2F target genes is extensive and includes many metabolic genes, yet the significance of E2F in controlling the expression of these genes remains largely unknown. Here, we used the CRISPR/Cas9 technology to introduce point mutations in the E2F sites upstream of five endogenous metabolic genes in Drosophila melanogaster. We found that the impact of these mutations on both the recruitment of E2F and the expression of the target genes varied, with the glycolytic gene, Phosphoglycerate kinase (Pgk), being mostly affected. The loss of E2F regulation on the Pgk gene led to a decrease in glycolytic flux, tricarboxylic acid cycle intermediates levels, adenosine triphosphate (ATP) content, and an abnormal mitochondrial morphology. Remarkably, chromatin accessibility was significantly reduced at multiple genomic regions in PgkΔE2F mutants. These regions contained hundreds of genes, including metabolic genes that were downregulated in PgkΔE2F mutants. Moreover, PgkΔE2F animals had shortened life span and exhibited defects in high-energy consuming organs, such as ovaries and muscles. Collectively, our results illustrate how the pleiotropic effects on metabolism, gene expression, and development in the PgkΔE2F animals underscore the importance of E2F regulation on a single E2F target, Pgk.

Transcanal endoscopic ear surgery for glomus tympanicum removal: A case series on the necessity of preoperative embolization.

BACKGROUND: Transcanal endoscopic ear surgery (TEES) has become popular in recent years in the treatment of glomus tympanicum tumors (GTT). The most significant risk for TEES is bleeding. In some cases, preoperative vascular embolization is performed to mitigate bleeding during TEES. However, guidelines regarding the necessity and efficacy of preoperative vascular embolization have not been established yet. CASE PRESENTATION: This report aimed to assess the necessity and usefulness of preoperative vascular embolization in TEES for GTT by comparing the surgical findings of TEES without preoperative vascular embolization (Case 1) and TEES with preoperative vascular embolization (Case 2). Compared to Case 1, Case 2 included less bleeding and a more convenient procedure. However, no significant difference was observed. CONCLUSIONS: For GTT confined to the middle ear cavity (Glasscock-Jackson Grade II or less), when performed by a proficient otolaryngologist, TEES alone is sufficient without preoperative vascular embolization.

Transcanal endoscopic myringoplasty with butterfly dermal allograft.

OBJECTIVE: Tympanic membrane perforation (TMP) is a common cause of visits to the otolaryngology clinic. For decades, various surgical methods and various grafts have been used to treat TMP. This study aimed to compare the efficacy of butterfly dermal allograft (BDA) and fat myringoplasty for the treatment of TMP. STUDY DESIGN: A retrospective case-control study. SETTING: Tertiary referral center. METHODS: We retrospectively analyzed 40 patients who underwent BDA (n = 20) and fat myringoplasty (n = 20) for TMP performed by a single surgeon between January 2019 and December 2021. The hearing outcomes, graft success rate, complications, operation time, and hospital stay were recorded and compared between the two groups. Hearing outcomes were determined by pure-tone audiometry. RESULTS: There was no significant difference between the BDA and fat groups regarding demographic characteristics. There was no significant difference in the pre and postoperative air conduction and bone conduction thresholds, or air-bone gap values between the two groups. A significant audiologic improvement was observed in both groups (p < 0.05), but there was no significant difference in the degree of hearing gain between the two groups. In terms of recurrence of tympanic membrane perforation, postoperative otorrhea, and discomfort symptoms; however, there was no significant difference between the groups (p > 0.05). The operation time and hospital stay were shorter in the BDA group than in the fat group (p < 0.05). CONCLUSION: BDA myringoplasty is as safe and medically efficacious as fat myringoplasty and shortens the operation time and hospital stay.

Treatment results for congenital cholesteatoma using transcanal endoscopic ear surgery.

PURPOSE: Transcanal endoscopic ear surgery for congenital cholesteatoma provides a smaller incision and better visibility than conventional surgical microscope ear surgery. We aimed to evaluate the treatment results of transcanal endoscopic ear surgery in ameliorating the recurrence and post-operative complications of pediatric congenital cholesteatoma. MATERIALS AND METHODS: A retrospective chart review was conducted on patients with congenital cholesteatoma who underwent transcanal endoscopic ear surgery at a tertiary referral medical center from January 2012 to December 2020. We categorized the patients into two groups according to the presence of remnant cholesteatoma and compared their characteristics. RESULTS: This study included 46 patients (32 males and 14 females; 46 ears). The mean age was 3.0 ± 2.6 (1-17) years. Congenital cholesteatoma was predominantly located in the anterior-superior quadrant (63.0 %), and ossicular involvement was confirmed in six cases. The mean cholesteatoma size identified by temporal bone computed tomography was 3.9 ± 2.0 (1.2-13) mm. Seven cases had remnant cholesteatoma lesions (15.2 %); four improved after revision surgery, and three were followed up without immediate further intervention. Postoperative complications (e.g., tympanic membrane perforation, retraction) were observed in 10 cases. Comparative evaluations of various characteristics after categorizing the participants into residual and non-residual lesion groups revealed no significant differences. CONCLUSIONS: Consequently, transcanal endoscopic ear surgery can be considered an effective and safe operation for treating congenital cholesteatoma in the pediatric population with no serious side effects. Further large-scale research with hearing test results should be conducted meticulously as a follow-up to this study.

CRISPR/Cas9-Mediated Editing of AGAMOUS-like Genes Results in a Late-Bolting Phenotype in Chinese Cabbage (Brassica rapa ssp. pekinensis).

Due to the sudden change in temperature in spring, Chinese cabbage, a leafy vegetable cultivated for consumption, loses its commercial value due to the onset of bolting­the phenomenon of switching from vegetative to reproductive growth. In this study, we applied clustered regularly interspaced short palindromic repeats/(CRISPR)-associated system 9 (CRISPR/Cas9) technology to analyze AGAMOUS-like genes. We performed functional analysis of AGL19 and AGL24 genes related to bolting and flowering using CRISPR/Cas9-mediated Chinese cabbage transformation. Single-guide RNA (sgRNA) sequences were created with a low off-targeting probability to construct gene-editing vectors. Agrobacterium-mediated transformation was conducted, and tentative E0 AGL-edited lines were analyzed using molecular biotechnological methods. Two AGL19-edited lines with nucleotide sequence mutations in the target sequence of the AGL19 genes and four AGL24-edited lines with nucleotide sequence mutations in the target sequence of the AGL24 genes showed particularly late bolting compared to the inbred line 'CT001.' Generational progression using bud pollination obtained T-DNA-free E1 AGL-edited lines, which also showed late bolting. The loss of function of the AGL protein was caused by the occurrence of an indel mutation in the AGL19 and AGL24 genes, which results in an early stop codon. Furthermore, frameshift mutations led to structural changes and the introduction of an early stop codon in the AGL19 and AGL24 proteins. Our results indicate that CRISPR/Cas9-mediated editing of AGAMOUS-like genes results in a late-bolting phenotype and that CRISPR/Cas9 is a useful technology for analyzing gene function in Chinese cabbage (Brassica rapa ssp. pekinensis).

Predicting hearing recovery following treatment of idiopathic sudden sensorineural hearing loss with machine learning models.

PURPOSE: Idiopathic sudden sensorineural hearing loss (ISSHL) is an emergency otological disease, and its definite prognostic factors remain unclear. This study applied machine learning methods to develop a new ISSHL prognosis prediction model. MATERIALS AND METHODS: This retrospective study reviewed the medical data of 244 patients who underwent combined intratympanic and systemic steroid treatment for ISSHL at a tertiary referral center between January 2015 and October 2019. We used 35 variables to predict hearing recovery based on Siegel's criteria. In addition to performing an analysis based on the conventional logistic regression model, we developed prediction models with five machine learning methods: least absolute shrinkage and selection operator, decision tree, random forest (RF), support vector machine, and boosting. To compare the predictive ability of each model, the accuracy, precision, recall, F-score, and the area under the receiver operator characteristic curves (ROC-AUC) were calculated. RESULTS: Former otological history, ear fullness, delay between symptom onset and treatment, delay between symptom onset and intratympanic steroid injection (ITSI), and initial hearing thresholds of the affected and unaffected ears differed significantly between the recovery and non-recovery groups. While the RF method (accuracy: 72.22%, ROC-AUC: 0.7445) achieved the highest predictive power, the other methods also featured relatively good predictive power. In the RF model, the following variables were identified to be important for hearing-recovery prediction: delay between symptom onset and ITSI or the initial treatment, initial hearing levels of the affected and non-affected ears, body mass index, and a previous history of hearing loss. CONCLUSIONS: The machine learning models predictive of hearing recovery following treatment for ISSHL showed superior predictive power relative to the conventional logistic regression method, potentially allowing for better patient treatment outcomes.

Comparative study of endoscopic and microscopic tympanoplasty performed by a single experienced surgeon.

PURPOSE: The use of endoscopes in otologic procedures has been increasing worldwide. This study aimed to compare the efficacy of microscopic tympanoplasty (MT) and endoscopic tympanoplasty (ET) for tympanic membrane and middle ear surgery. MATERIALS AND METHODS: We retrospectively analyzed 81 patients who underwent MT (n = 44) and ET (n = 37) for chronic otitis media with tympanic membrane perforation performed by a single surgeon between January 2013 and September 2019. The hearing outcomes, graft success rate, complications, operation time and hospital stay, and cost-effectiveness were recorded and compared between groups. Hearing outcomes were determined by pure tone audiometry. Cost-effectiveness was determined by the operation cost and total cost. RESULTS: There was no significant difference between the MT and ET groups regarding demographic characteristics, with the exception of the male:female ratio. There was no significant difference in the pre- and postoperative air conduction, bone conduction thresholds, and air-bone gap values between the two groups, but a significant audiologic improvement was observed in both groups (p < 0.05). In terms of recurrence of tympanic membrane perforation, postoperative otorrhea, and discomfort symptoms, there was no significant difference between groups (p > 0.05). The operation time and hospital stay were shorter in the ET group than in the MT group (p < 0.05). There were no significant differences in operation cost between the two groups (p > 0.05), but the total cost was significantly lower in the ET group than the MT group (p < 0.05). CONCLUSION: ET is as safe and medically efficacious as conventional MT, shortens the operation time and hospital stay, and is cost-effective.

Mercury Chloride but Not Lead Acetate Causes Apoptotic Cell Death in Human Lung Fibroblast MRC5 Cells via Regulation of Cell Cycle Progression.

Heavy metals are important for various biological systems, but, in excess, they pose a serious risk to human health. Heavy metals are commonly used in consumer and industrial products. Despite the increasing evidence on the adverse effects of heavy metals, the detailed mechanisms underlying their action on lung cancer progression are still poorly understood. In the present study, we investigated whether heavy metals (mercury chloride and lead acetate) affect cell viability, cell cycle, and apoptotic cell death in human lung fibroblast MRC5 cells. The results showed that mercury chloride arrested the sub-G1 and G2/M phases by inducing cyclin B1 expression. In addition, the exposure to mercury chloride increased apoptosis through the activation of caspase-3. However, lead had no cytotoxic effects on human lung fibroblast MRC5 cells at low concentration. These findings demonstrated that mercury chloride affects the cytotoxicity of MRC5 cells by increasing cell cycle progression and apoptotic cell death.

Transcriptome Analysis Reveals HgCl2 Induces Apoptotic Cell Death in Human Lung Carcinoma H1299 Cells through Caspase-3-Independent Pathway.

Mercury is one of the detrimental toxicants that can be found in the environment and exists naturally in different forms; inorganic and organic. Human exposure to inorganic mercury, such as mercury chloride, occurs through air pollution, absorption of food or water, and personal care products. This study aimed to investigate the effect of HgCl2 on cell viability, cell cycle, apoptotic pathway, and alters of the transcriptome profiles in human non-small cell lung cancer cells, H1299. Our data show that HgCl2 treatment causes inhibition of cell growth via cell cycle arrest at G0/G1- and S-phase. In addition, HgCl2 induces apoptotic cell death through the caspase-3-independent pathway. Comprehensive transcriptome analysis using RNA-seq indicated that cellular nitrogen compound metabolic process, cellular metabolism, and translation for biological processes-related gene sets were significantly up- and downregulated by HgCl2 treatment. Interestingly, comparative gene expression patterns by RNA-seq indicated that mitochondrial ribosomal proteins were markedly altered by low-dose of HgCl2 treatment. Altogether, these data show that HgCl2 induces apoptotic cell death through the dysfunction of mitochondria.

EEG-Based Evidence of Mirror Neuron Activity from App-Mediated Stroke Patient Observation.

Background and Objectives: The mirror neuron system in the sensorimotor region of the cerebral cortex is equally activated during both action observation and execution. Action observation training mimics the functioning of the mirror neuron system, requiring patients to watch and imitate the actions necessary to perform activities of daily living. StrokeCare is a user-friendly application based on the principles of action observation training, designed to assist people recovering from stroke. Therefore, when observing the daily life behavior provided in the StrokeCare app, whether the MNS is activated and mu inhibition appears. Materials and Methods: We performed electroencephalography (EEG) on 24 patients with chronic stroke (infarction: 11, hemorrhage: 13) during tasks closely related to daily activities, such as dressing, undressing, and walking. The StrokeCare app provided action videos for patients to watch. Landscape imagery observation facilitated comparison among tasks. We analyzed the mu rhythm from the C3, CZ, and C4 regions and calculated the mean log ratios for comparison of mu suppression values. Results: The EEG mu power log ratios were significantly suppressed during action observation in dressing, undressing, walking, and landscape conditions, in decreasing order. However, there were no significant activity differences in the C3, C4 and CZ regions. The dressing task showed maximum suppression after a color spectrum was used to map the relative power values of the mu rhythm for each task. Conclusions: These findings reveal that the human mirror neuron system was more strongly activated during observation of actions closely related to daily life activities than landscape images.

Biodegradation of Polystyrene by Pseudomonas sp. Isolated from the Gut of Superworms (Larvae of Zophobas atratus).

Recently, various attempts have been made to solve plastic waste problems, such as development of biodegradation without producing pollution. Polystyrene (PS) is the fifth most used plastic in many industries; therefore, degrading PS becomes a critical global issue. Here, we reported Pseudomonas aeruginosa strain DSM 50071, initially isolated from the gut of the superworms, Zophobas atratus, and the PS degradation by Pseudomonas sp. DSM 50071. We examined PS degradation using electronic microscopy and measured changes in atomic composition and contact angles with water droplets on the PS surface that represents a chemical change from hydrophobicity to hydrophilicity. We have further examined chemical structural changes using X-ray photoelectron spectroscopy, Fourier-transform-infrared spectroscopy, and nuclear magnetic resonance (NMR) to confirm the formation of carbonyl groups (C═O) in the oxidation pathway during PS biodegradation. In reverse transcription quantitative polymerase chain reaction analysis, the gene expression level of serine hydrolase (SH) in Pseudomonas sp. DSM 50071 was highly increased during PS degradation, and the enzyme-mediated biodegradation of PS was further confirmed by the SH inhibitor treatment test. Thus, the significance of these findings goes beyond the discovery of a novel function of Pseudomonas sp. DSM 50071 in the gut of superworms, highlighting a potential solution for PS biodegradation.

The usefulness of Valsalva computed tomography as an assessment tool for the Eustachian tube.

PURPOSE: To determine the usefulness of 'computed tomography (CT) with Valsalva maneuver (VM)' (Valsalva CT) for localizing lesions of the eustachian tube (ET) and identifying characteristics of ET dysfunction (ETD). MATERIALS AND METHODS: In this case-control study, 12, 17, and 25 patients with obstructive ETD (OETD), patulous eustachian tube (PET), and conductive hearing loss (control), respectively, underwent Valsalva CT in the supine position. The visualized length to total length ratio of the cartilaginous ET (VTRET) with and without VM were compared in the three groups. In the OETD group, obstructed areas of the ET were identified on multiplanar reconstructed images. RESULTS: VTRET without VM in the PET group was significantly higher than that in the control and OETD groups (p-values, 0.003 and 0.007, respectively). However, there was no significant difference between the control and OETD groups (p = 0.053). VTRET with VM in the PET group was significantly higher than that in the other two groups (p < 0.001), whereas that in the control group was significantly higher than that in the OETD group (p < 0.001). In the OETD group, the obstructed area was clearly identified, and there were one, one, six, and eight patients in the isthmus; bony portion and isthmus; bony portion, isthmus, and cartilaginous portion; and isthmus and cartilaginous portion subgroups, respectively. CONCLUSION: Valsalva CT is particularly valuable as a visualization assessment tool for identifying obstructed areas in the OETD. It may help future research of disease-specific mechanical characteristics of the ET on controlling pressure variables.

Effects of meteorological factor and air pollution on sudden sensorineural hearing loss using the health claims data in Busan, Republic of Korea.

PURPOSE: Specific meteorological factors, including air pollution in the form of particulate matter (PM), affect the development of otologic disease and have adverse effects on the cardiovascular and respiratory systems. This study investigated relationships between the development of sudden sensorineural hearing loss(SSNHL) and meteorological factor with air pollution including PM. MATERIALS AND METHODS: The daily patient number in 2015 admitted to the hospital with SSNHL were extracted from the Health Insurance Review and Assessment Service Bigdata in Busan. The meteorological factors and air pollution data of Busan area were obtained from meteorological stations in Busan. The relationship between the number of hospitalizations and the climatic factors was checked. RESULTS: SSNHL patient group showed more common in women, and the highest rates were observed in patients in their 50s. The daily mean patient numbers were 2.27. The number of SSNHL patients in spring was statistically significantly higher than that in summer. The mean daily PM10 and PM2.5 concentrations were 48.0 and 29.4 µg/m3, respectively. The mean wind speed, maximum wind speed and daily atmospheric pressure range was weakly positively associated with SSNHL patient number. There were weak negative correlations between maximum PM2.5 and SSNHL admissions. The mean temperature and wind chill index showed non-significantly negative relationships with SSNHL admissions. CONCLUSIONS: In Busan area, statistically significant weak relationships were detected between the daily numbers of patients admitted to the hospital with SSNHL and meteorological data, including PM level. Further investigation of these associations is required.

Audiologic, surgical and subjective outcomes of active transcutaneous bone conduction implant system (Bonebridge).

Objective: Our objective was to evaluate the surgical restrictions, audiologic benefits and satisfaction from using an active transcutaneous bone conduction device (BCD), Bonebridge® (BB) in patients with mixed/conductive hearing loss (MCHL) or single-sided deafness (SSD).Design: A retrospective review from all patients who underwent BB surgery at the Pusan National University Hospital from 2015 to 2017 for SSD or MCHL was performed.Study sample: Twenty-two patients with SSD and five with MCHL had a BB implanted and analysed.Results: Complete transmastoid implantation of the device was possible for all patients with an intact canal wall (ICW), using lifts if necessary. The overall functional hearing gain (FHG) in SSD and MCHL was 31.4 and 37.6 dB, respectively. The mean percentage of speech recognition in a quiet was 81% (vs. 11% unaided) for MCHL group and 82% (vs. 29% unaided) for SSD group. Mean speech recognition scores in noise improved significantly under various signal-to-noise ratio (SNR) for both groups. Questionnaires showed overall improvement, and there was no significant difference between the two groups.Conclusions: The BB provides improved functional gain, and there were no limitations during surgery despite the large device. Both MCHL and SSD group had benefit and improved quality of life with BB.

Comparison of Two Different Treatment Protocols Using Systemic and Intratympanic Steroids with and without Hyperbaric Oxygen Therapy in Patients with Severe to Profound Idiopathic Sudden Sensorineural Hearing Loss: A Randomized Controlled Trial.

OBJECTIVES: This study aimed to investigate the efficacy of simultaneous steroid and hyperbaric oxygen therapy (HBOT) in patients with severe to profound idiopathic sudden sensorineural hearing loss (ISSNHL), which has a poor prognosis. METHODS: Sixty patients diagnosed with severe to profound ISSNHL (≥70 dB HL) were randomly divided into two groups in a prospective controlled trial: an oral steroid + intratympanic steroid injection (ITSI) group (control group) and an oral steroid + ITSI + HBOT group (study group). Pure-tone audiometry (PTA) results and word discrimination scores (WDS) were compared between the two groups before treatment and 10 days and 1, 2, and 3 months after treatment. Hearing improvement was assessed using the modified American Academy of Otolaryngology-Head and Neck Surgery criteria. Analyses were by both intention to treat and per protocol. RESULTS: A total of 58 patients completed the 3-month follow-up, and 2 patients in the study group were excluded due to follow-up loss in the per-protocol analysis. In the intention-to-treat and per-protocol analyses, the study group showed significantly better hearing levels than did the control group at 500 Hz (p < 0.05) 1 month after treatment and at 1 kHz (p < 0.05) 3 months after treatment. However, the average PTA values and PTA at 2, 4, and 8 kHz showed no significant difference. WDS improvement was significantly higher in the study group compared to the control group 3 months after treatment by both per-protocol (66.4 ± 13.3 and 56.7 ± 19.1%, respectively; p = 0.029) and intention-to-treat analyses (65.9 ± 14.1 and 56.7 ± 19.1%, respectively; p = 0.035). The sum of complete and partial hearing recovery for the study group was significantly higher than that for the control group by per-protocol analysis (60.7 vs. 33.3%; p = 0.037) and intention-to-treat analysis (60.0 vs. 33.3%; p = 0.038). CONCLUSION: These results demonstrate that the addition of HBOT to steroid combination therapy does not improve the average PTA values in severe to profound ISSNHL; however, it was associated with a better outcome at 500 Hz 1 month after treatment and, at 1 kHz, WDS 3 months after treatment. The sum of complete and partial hearing recovery was significantly higher for the study group than for the control group.

Prevalence and incidence of clinically significant patulous Eustachian tube: A population-based study using the Korean National Health Insurance Claims Database.

OBJECTIVES: The aim of this study is to estimate the entire population-based prevalence and incidence of Patulous Eustachian tube (PET) using the Korean National Health Insurance (NHI) claims database. The annual trends of prevalence and incidence of PET were also investigated. METHODS: Retrospective analysis of PET patients was performed between 2010 and 2016, from the NHI claims database. PET patients were defined as those who had at least one service claim with a primary diagnosis under an ICD-10-based PET code (H69.0). RESULTS: During the study period, there were 20,533 new PET patients in Korea. In 2016 there were 4482 incident cases, and the standardized annual incidence rate was 8.8 per 100,000 persons. The standardized annual prevalence rate increased significantly from 7.2 per 100,000 persons in 2010 to 10.3 per 100,000 persons in 2016. The prevalence increased significantly on annual basis, whereas the incidence rate fluctuated over time. Interestingly, the incidence and prevalence of PET in women was almost twice as high as that in men, and peaked in their 20s. CONCLUSIONS: This study demonstrated the substantial annual increase of the NHI claims with PET code (H69.0) in Korea from 2010 to 2016. Statistical results based on the NHI claims, we confirmed the high prevalence and incidence rates of clinically significant PET in women than in men. This study only covered patient using the medical service for PET and missed PET sufferers not seeking medical service. However, this study can provide basic epidemiological information on clinically significant PET.

Application of endoscopy in otology: Changes over the last 8years in Korean Otological Society.

OBJECTIVES: Despite the worldwide availability of endoscope in otology, it still has not replaced the microscopic surgery as it has for nose surgery. In 2008, we administered a questionnaire on the preference of using otoscopes in Korea. In light of the worldwide availability of endoscopic ear surgery, we have now conducted a more detailed survey to determine if this preference has changed over 8years. SUBJECTS AND METHODS: A questionnaire consisting of 10 questions was used to survey members of the Korean Otological Society who were actively performing middle ear surgery. The responses to this questionnaire were compared to those from 2008. The study also determined the preference for endoscope use based on the surgeon's experience. RESULTS: The mean surgical experience of the otologists was 12.7years. Endoscopy for tympanoplasty and tympanomastoidectomy increased over a period of 8years. In the outpatient clinic, the use of endoscopy also increased; over 8-year period, it surpassed the microscope as the most preferred diagnostic tool in the outpatient clinic. Greater than half of the operating rooms were equipped with endoscopic sets; however, only 4.5% of otologists acknowledged having endoscopic instruments. CONCLUSION: Endoscopy for surgery and in outpatient clinic assessment increased in otology in Korea; however, endoscopes have consistently been used as an adjuvant to the microscope to improve visualization of the tympanic cavity rather than as a tool for totally endoscopic ear surgery.

Hearing aid silicone impression material as a foreign body in the middle ear.

We report an extremely rare case of hearing aid silicone impression material as a foreign body in the middle ear. Symptoms of the patient were otorrhea and vertigo after taking of a mold impression on his only hearing ear, and the symptoms mimicked chronic otitis media. A temporal bone CT scan revealed foreign body material in the middle ear and Eustachian tube. An intact canal wall mastoidectomy with a facial recess approach and type IV tympanoplasty was performed to remove the silicone impression material. In addition to the case report, we review the literature regarding impression material foreign bodies.

Clinical and audiological characteristics of 1000Hz audiometric notch patients.

PURPOSE: Among the hearing loss patients, we can confirm that the hearing loss of the specific frequency decreases, such as the 2000Hz notch in otosclerosis and the 4000Hz notch (c5-dip) in noise-induced hearing loss. The 1000Hz notch (c3-dip), however, is rarely studied. We fortuitously encountered a group of patients with a 1kHz hearing loss and report it with a review of the literature. METHODS: Otological history, audiogram, diagnosis, occupation, and history of noise exposure were reviewed from charts and telephone interview, and compared between c3-dip and c5-dip patients (n=98). RESULTS: Thirty-one patients (mean age: 46.2years) demonstrated 1kHz hearing loss; these included 11 males. The pure-tone threshold was 37.97dB at 1kHz and the average threshold was 22.38dB at other frequencies. In the c3-dip group, tinnitus was the most common complaint, while sudden sensorineural hearing loss and idiopathic tinnitus (n=8 each) were the most common diagnoses. Female patients and unilateral cases were more common in the c3-dip than in the c5-dip group, and ear fullness was more common in the c3-dip group than in the c5-dip group. The duration of occupation-related noise exposure was longer in the c5 group, and head or ear trauma was more frequent in the c3-dip group. CONCLUSION: We have defined a new clinical entity of 1kHz hearing loss in patients, defined as the c3-dip, which was clinically and audiologically distinct from the c5-dip. Further study is needed to clarify this new entity of hearing loss.

A novel endoscopic fluorescent band ligation method for tumor localization.

BACKGROUND: Accurate tumor localization is essential for minimally invasive surgery. This study describes the development of a novel endoscopic fluorescent band ligation method for the rapid and accurate identification of tumor sites during surgery. METHODS AND MATERIALS: The method utilized a fluorescent rubber band, made of indocyanine green (ICG) and a liquid rubber solution mixture, as well as a near-infrared fluorescence laparoscopic system with a dual light source using a high-powered light-emitting diode (LED) and a 785-nm laser diode. The fluorescent rubber bands were endoscopically placed on the mucosae of porcine stomachs and colons. During subsequent conventional laparoscopic stomach and colon surgery, the fluorescent bands were assayed using the near-infrared fluorescence laparoscopy system. RESULTS: The locations of the fluorescent clips were clearly identified on the fluorescence images in real time. The system was able to distinguish the two or three bands marked on the mucosal surfaces of the stomach and colon. Resection margins around the fluorescent bands were sufficient in the resected specimens obtained during stomach and colon surgery. CONCLUSION: These novel endoscopic fluorescent bands could be rapidly and accurately localized during stomach and colon surgery. Use of these bands may make possible the excision of exact target sites during minimally invasive gastrointestinal surgery.