1.Residual Dizziness after Benign Paroxysmal Positional Vertigo
Munyoung CHANG ; Seog-Kyun MUN
Korean Journal of Otolaryngology - Head and Neck Surgery 2020;63(10):443-447
Benign paroxysmal positional vertigo (BPPV) is one of the most common diseases that cause dizziness. It can be resolved relatively easily using canalith-repositioning maneuvers. However, some patients suffer from dizziness even after successful canalith-repositioning. This is an atypical dizziness felt in the absence of typical nystagmus after resolution of BPPV and named residual dizziness. Otolithic organ disorder, anxiety and persistence of debris in the canal have been reported to be associated with residual dizziness. Although 31-61% of BPPV patients suffer from residual dizziness, residual dizziness has not yet been clearly known not only the treatment but also the pathophysiology. This article investigate the factors associated with residual dizziness and treatment and prediction methods for residual dizziness.
2.Effect of Temporal Bone Fracture on the Prognosis of Benign Paroxysmal Positional Vertigo
Munyoung CHANG ; Sei Young LEE ; Seog-Kyun MUN
Korean Journal of Otolaryngology - Head and Neck Surgery 2021;64(12):868-873
Background and Objectives:
This study aimed to investigate whether benign paroxysmal positional vertigo (BPPV) accompanied by temporal bone fracture would be more resistant to canalith repositioning procedures (CRPs) than idiopathic BPPV.Subjects and Method Seventy-eight patients with BPPV were included in this study. Among them, 13 patients had temporal bone fractures and 65 had no temporal bone fractures. To identify the factors related to the number of CRPs performed until the remission of BPPV, sex, age, the presence of temporal bone fracture, hypertension, diabetes, dyslipidemia or osteopenia, BPPV affected side, and the type of affected semicircular canal were analyzed using the univariable regression analysis. Thereafter, the multivariable regression analysis was performed using only the variables that had a p-value of 0.2 or less in the univariable analysis.
Results:
In the univariable analysis, temporal bone fracture, diabetes mellitus, and BPPV side showed relatively significant association with the number of CRPs (p<0.2). In the multivariable analysis, only temporal bone fracture showed a significant association with the number of CRPs (p=0.043, β=0.532, 95% CI: 0.017-1.046).
Conclusion
The major finding of this study is that BPPV, accompanied by temporal bone fracture, precipitated more resistance to CRPs than idiopathic BPPV did. Thus, patients with temporal bone fracture might need more intensive examination and treatment for BPPV than those without temporal bone fracture.
3.Novel Tie Method for the Fixation of a Brain Infusion Cannula in a Murine Model
Seog-Kyun MUN ; Munyoung CHANG
Korean Journal of Otolaryngology - Head and Neck Surgery 2021;64(5):370-372
Although brain infusion cannula is a good method to deliver compounds directly into the brain, fixation of the brain infusion cannula is essential for successful delivery. Dental cements and adhesive gel are the commonly used materials for fixation of the infusion cannula. However, these materials take time to harden and occasionally, fixation may fail. Therefore, we developed a novel method to fix the brain infusion cannula. Brain infusion cannulas were implanted into seven Wistar rats using the novel tie method. One, three, and seven days after the surgery, displacement of the brain infusion cannula and cerebrospinal fluid (CSF) leakage were evaluated in all the rats. None of the animals showed displacement of the brain infusion cannula or leakage of CSF at any point of time. In this study, we showed the successful results of the novel tie method for fixation of the brain infusion cannula, which needs no additional materials. It only requires a thread which is used for skin sutures.
4.Intratympanic injection for treatment of inner ear diseases
Hyun-Jin LEE ; Munyoung CHANG ; Seog-Kyun MUN
Journal of the Korean Medical Association 2023;66(10):589-596
Intratympanic injection has emerged as a novel approach to bypass the blood-labyrinth barrier and effectively deliver drugs into the inner ear. This technique is used for treatment of various inner ear diseases and overcomes the limitations of systemic drug therapy. In this paper, we provide an overview of the application of intratympanic injection using steroids and gentamicin and highlight the major diseases and summarize the reported efficacy of this approach.Current Concepts: Intratympanic steroid injections have been used for treatment of various inner ear diseases, including sudden sensorineural hearing loss, Ménière disease, and tinnitus. Therapeutic effects of steroids include reducing inflammation, modulating the immune response, improving cochlear blood flow, and maintaining ion homeostasis. Intratympanic gentamicin injections are primarily used to minimize hearing loss and control vertigo symptoms in patients with Ménière disease. Gentamicin selectively injures vestibular hair cells with minimal ototoxicity compared with other aminoglycoside antibiotics.Discussion and Conclusion: Intratympanic injections offer several advantages, including targeted drug delivery, minimal systemic adverse effects, and rapid action. Reportedly, intratympanic steroid injections used as primary or salvage treatment are associated with positive outcomes in patients with sudden sensorineural hearing loss. Ménière disease also shows positive outcomes following intratympanic steroid and gentamicin injections. However, studies have reported conflicting results, and further research is required to standardize dosing and administration protocols. Intratympanic injections are a promising therapeutic option, and ongoing research is essential to optimize their efficacy and safety.
5.Cytoprotective effects of Morinda officinalis against hydrogen peroxide-induced oxidative stress in Leydig TM3 cells.
Mun-Seog CHANG ; Won-Nam KIM ; Woong-Mo YANG ; Hyu-Young KIM ; Ji-Hoon OH ; Seong-Kyu PARK
Asian Journal of Andrology 2008;10(4):667-674
AIMTo investigate the antioxidant effects of Morinda officinalis (Morindae radix, MR) on H(2)O(2)-induced oxidative stress in cultured mouse TM3 Leydig cells.
METHODSWe carried out 2,2-diphenyl-1-picrylhydrazyl free radical scavenging, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, lipid peroxidation, testosterone enzyme immunoassay, superoxide dismutase (SOD), and catalase (CAT) assays in Leydig TM3 cells.
RESULTSMR showed a 47.8% 2,2-diphenyl-1-picrylhydrazyl radical scavenging effect in TM3 cells with no significant cytotoxicity. Oxidative stress was induced in TM3 cells with 100 micromol H(2)O(2), and treatment of the cells with 250 microg/mL MR showed the most significant protective effect (64%, P < 0.001) in the cell viability assay with a decreased lipid peroxidation level (1.75 nmol/mg protein, P < 0.05), increased testosterone production (43.5 pg/mL), and improvements in SOD activity (7.49 units of SOD/mg protein, P < 0.001) and CAT activity (74.6 units of CAT/mg protein, P < 0.001).
CONCLUSIONThese findings indicate that MR, as an antioxidant, protects functions of cultured mouse TM3 Leydig cells from H(2)O(2)-induced oxidative stress.
Animals ; Catalase ; metabolism ; Cell Survival ; drug effects ; Cells, Cultured ; Hydrogen Peroxide ; adverse effects ; Leydig Cells ; cytology ; drug effects ; metabolism ; Lipid Peroxidation ; drug effects ; Male ; Mice ; Morinda ; Oxidative Stress ; drug effects ; Plant Extracts ; pharmacology ; RNA, Messenger ; metabolism ; Superoxide Dismutase ; metabolism ; Testosterone ; metabolism
6.Machine Learning Models for Predicting the Occurrence of Respiratory Diseases Using Climatic and Air-Pollution Factors
Yunseo KU ; Soon Bin KWON ; Jeong-Hwa YOON ; Seog-Kyun MUN ; Munyoung CHANG
Clinical and Experimental Otorhinolaryngology 2022;15(2):168-176
Objectives:
. Because climatic and air-pollution factors are known to influence the occurrence of respiratory diseases, we used these factors to develop machine learning models for predicting the occurrence of respiratory diseases.
Methods:
. We obtained the daily number of respiratory disease patients in Seoul. We used climatic and air-pollution factors to predict the daily number of patients treated for respiratory diseases per 10,000 inhabitants. We applied the relief-based feature selection algorithm to evaluate the importance of feature selection. We used the gradient boosting and Gaussian process regression (GPR) methods, respectively, to develop two different prediction models. We also employed the holdout cross-validation method, in which 75% of the data was used to train the model, and the remaining 25% was used to test the trained model. We determined the estimated number of respiratory disease patients by applying the developed prediction models to the test set. To evaluate the performance of each model, we calculated the coefficient of determination (R2) and the root mean square error (RMSE) between the original and estimated numbers of respiratory disease patients. We used the Shapley Additive exPlanations (SHAP) approach to interpret the estimated output of each machine learning model.
Results:
. Features with negative weights in the relief-based algorithm were excluded. When applying gradient boosting to unseen test data, R2 and RMSE were 0.68 and 13.8, respectively. For GPR, the R2 and RMSE were 0.67 and 13.9, respectively. SHAP analysis showed that reductions in average temperature, daylight duration, average humidity, sulfur dioxide (SO2), total solar insolation amount, and temperature difference increased the number of respiratory disease patients, whereas increases in atmospheric pressure, carbon monoxide (CO), and particulate matter ≤2.5 μm in aerodynamic diameter (PM2.5) increased the number of respiratory disease patients.
Conclusion
. We successfully developed models for predicting the occurrence of respiratory diseases using climatic and air-pollution factors. These models could evolve into public warning systems.
7.Losartan Prevents Maladaptive Auditory-Somatosensory Plasticity After Hearing Loss via Transforming Growth Factor-β Signaling Suppression
Seog Kyun MUN ; Kyu Hee HAN ; Jong Tae BAEK ; Suk Won AHN ; Hyun Sang CHO ; Mun Young CHANG
Clinical and Experimental Otorhinolaryngology 2019;12(1):33-39
OBJECTIVES: Hearing loss disrupts the balance of auditory-somatosensory inputs in the cochlear nucleus (CN) of the brainstem, which has been suggested to be a mechanism of tinnitus. This disruption results from maladaptive auditory-somatosensory plasticity, which is a form of axonal sprouting. Axonal sprouting is promoted by transforming growth factor (TGF)-β signaling, which can be inhibited by losartan. We investigated whether losartan prevents maladaptive auditory-somatosensory plasticity after hearing loss. METHODS: The study consisted of two stages: determining the time course of auditory-somatosensory plasticity following hearing loss and preventing auditory-somatosensory plasticity using losartan. In the first stage, rats were randomly divided into two groups: a control group that underwent a sham operation and a deaf group that underwent cochlea ablation on the left side. CNs were harvested 1 and 2 weeks after surgery. In the second stage, rats were randomly divided into either a saline group that underwent cochlear ablation on the left side and received normal saline or a losartan group that underwent cochlear ablation on the left side and received losartan. CNs were harvested 2 weeks after surgery. Hearing was estimated with auditory brainstem responses (ABRs). Western blotting was performed for vesicular glutamate transporter 1 (VGLUT1), reflecting auditory input; vesicular glutamate transporter 2 (VGLUT2), reflecting somatosensory input; growth-associated protein 43 (GAP-43), reflecting axonal sprouting; and p-Smad2/3. RESULTS: Baseline ABR thresholds before surgery ranged from 20 to 35 dB sound pressure level. After cochlear ablation, ABR thresholds were higher than 80 dB. In the first experiment, VGLUT2/VGLUT1 ratios did not differ significantly between the control and deaf groups 1 week after surgery. At 2 weeks after surgery, the deaf group had a significantly higher VGLUT2/VGLUT1 ratio compared to the control group. In the second experiment, the losartan group had a significantly lower VGLUT2/VGLUT1 ratio along with significantly lower p-Smad3 and GAP-43 levels compared to the saline group. CONCLUSION: Losartan might prevent axonal sprouting after hearing loss by blocking TGF-β signaling thereby preventing maladaptive auditory-somatosensory plasticity.
Animals
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Axons
;
Blotting, Western
;
Brain Stem
;
Cochlea
;
Cochlear Nucleus
;
Evoked Potentials, Auditory, Brain Stem
;
GAP-43 Protein
;
Hearing Loss
;
Hearing
;
Losartan
;
Plastics
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Rats
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Tinnitus
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Transforming Growth Factors
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Vesicular Glutamate Transport Protein 1
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Vesicular Glutamate Transport Protein 2
8.Cardiorespiratory response to maximal exercise loading in mild anemia.
Kyoung jae KIM ; Min Mo KANG ; Ji Hyun LEE ; Seog Mun CHOI ; Hyung Ho HUH ; Sung Gug CHANG ; Hi Myung PARK ; Yu Jin KIM ; Yu Moon KIM ; Jong Suk KIM
Korean Circulation Journal 1993;23(3):373-379
BACKGROUND: Mild iron deficiency anemia is known to be asymptomatic in most of the cases. In view of this, we studied response of the mild anemics to the maximal exercise loading test to learn whether or not they respond similarly to the normals. METHODS: The maximal exercise loading tests by Bruce's protocol were carried out in 22 female asymptomatic anemics with hemoglobin level of between 10.0gm/dL and less than 12.0gm/dL, and the results were compared with those of 44 non-anemic matched controls with mean hemoglobin level of 13.1gm/dL. The ages in both groups were in their 30's to 40's, and even the anemics were otherwise normal clinically and on various laboratory tests. RESULTS: There were no significant difference between two groups in VO2 max, HR max, VCO2 max and VE max and their derivatives including VT/VC and VE/MVV. CONCLUSIONS: Our results indicate that in patients with mild iron deficiency anemia, the cardiorespiratory response to maximal exercise loading is not different from the normals, and suggest that oxygen transport to tissues is not affected even at maximal exercise. probably by adaptive compensatory mechanism.
Anemia*
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Anemia, Iron-Deficiency
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Female
;
Humans
;
Oxygen
9.Differential Expressions of Genes in Colorectal Cancer with Liver Metastasis by using a cDNA Microarray Chip: A Pilot Study.
Jae O KIM ; Gyu Seog CHOI ; Sang Geol KIM ; Eun Jung CHANG ; Woo Ri KIM ; In Taek LEE ; Soo Han JUN ; Mun Kyu KIM ; Jeong Chul KIM
Journal of the Korean Society of Coloproctology 2007;23(2):116-128
PURPOSE: Liver metastasis is the most common type of failure in the treatment of colorectal cancer. The identification of differential expressions of genes in colorectal cancer and liver metastasis is important to differentiate the genetic mechanism of carcinogenesis and liver metastasis from that of a normal mucosa. The aim of this study is to find candidate genes playing roles in liver metastasis of colorectal cancer by using cDNA microarray. METHODS: We screened a group of genes differentially expressed in a normal mucosa and in cancer and liver metastasis by using a 4.7 K cDNA microarray chip in 8 patients with far advanced colorectal cancer from Jan 2003 to May 2004 at Kyungpook National University Hospital. RESULTS: A comparison of mRNA expressions of genes in normal mucosa vs. cancer, normal mucosa vs. liver metastasis, and cancer vs. liver metastasis, 76 and 27 known and unknown genes were significantly over-expressed in cancer and liver metastasis, respectively. Also 62 and 26 genes were down- regulated in cancer and liver metastasis. Among those genes, TIMP-1, SRY-box9, Rattus norvegicus fibronectin 1, mitotic check point regulator, etc. were constantly up- regulated in cancer or metastasis, and hsgk, etc. were down-regulated in cancer or liver metastasis. CONSLUSIONS: The cDNA microarray chip technique could be a useful for robust screening of candidate genes involved in carcinogenesis or metastasis of colorectal cancer.
Animals
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Carcinogenesis
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Colorectal Neoplasms*
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DNA, Complementary*
;
Fibronectins
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Gene Expression
;
Gyeongsangbuk-do
;
Humans
;
Liver*
;
Mass Screening
;
Mucous Membrane
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Neoplasm Metastasis*
;
Oligonucleotide Array Sequence Analysis*
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Pilot Projects*
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Rats
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RNA, Messenger
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Tissue Inhibitor of Metalloproteinase-1
10.The Measurement of Optimal Power Distance in LEDs.
Mi Kyung PARK ; Beom Joon KIM ; Myeung Nam KIM ; Seog Kyun MUN ; Hyuck Ki HONG ; Yeon Shik CHOI ; Young Chang JO
Korean Journal of Dermatology 2011;49(2):125-130
BACKGROUND: The use of light technology in dermatology has grown rapidly over the last decade, with many developments in its use for the treatment of a wide variety of skin conditions from non-melanoma skin cancers to facial resurfacing for photo-damaged skin. Light-emitting diodes (LEDs) have attracted much attention in medical fields. OBJECTIVE: (1) To assess the optimal distance of 630 nm LEDs (OmniLux(R), (Phototherapeutics Ltd, the UK)) and 830 nm LEDs (Healite(R) (Lutronic, Korea)) for maximum power as determined by a power meter and (2) to apply theory to practical use. METHODS: Two separate hinged planar light emitting diode arrays were studied: 1) the Omnilux Revive(TM) (Phototherapeutics Ltd, the UK), which delivers non-coherent red light at a wavelength of 633+/-3 nm and 2) the Lutronic Healite (Korea), which delivers non-coherent light at a wavelength of 830+/-5 nm. An X93 power meter (Gigahertz-Optik, Germany) was placed against a black background in order to reduce the amount of reflected light. We measured the LED powers over a range of 3~25 cm in 1 cm increments. RESULTS: On the irradiation side of the LED, power increases according to the mass effect of the radiation angle. However, at a certain distance, the power decline effect predominated over the amassment effect. In this respect, the LED light was estimated to be emitted in a reverse V shape. The proper irradiation distance for use in medical fields can thus be determined. CONCLUSION: The proper irradiation distance of LED will be useful and the proper use of LED under the subjects' shape will be done in many medical fields.
Dermatology
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Enzyme Multiplied Immunoassay Technique
;
Light
;
Skin
;
Skin Neoplasms