1.Supervised Model for Identifying Differentially Expressed Genes in DNA Microarray Gene Expression Dataset Using Biological Pathway Information.
Tae Su CHUNG ; Keewon KIM ; Ju Han KIM
Genomics & Informatics 2005;3(1):30-34
Microarray technology makes it possible to measure the expressions of tens of thousands of genes simultaneously under various experimental conditions. Identifying differentially expressed genes in each single experimental condition is one of the most common first steps in microarray gene expression data analysis. Reasonable choices of thresholds for determining differentially expressed genes are used for the next-step-analysis with suitable statistical significances. We present a supervised model for identifying DEGs using pathway information based on the global connectivity structure. Pathway information can be regarded as a collection of biological knowledge, thus we are trying to determine the optimal threshold so that the consequential connectivity structure can be the most compatible with the existing pathway information. The significant feature of our model is that it uses established knowledge as a reference to determine the direction of analyzing microarray dataset. In the most of previous work, only intrinsic information in the miroarray is used for the identifying DEGs. We hope that our proposed method could contribute to construct biologically meaningful structure from microarray datasets.
Dataset*
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DNA*
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Gene Expression*
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Hope
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Oligonucleotide Array Sequence Analysis*
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Statistics as Topic
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Transcutaneous Electric Nerve Stimulation
2.Intraoperative Neurophysiology Monitoring for Spinal Dysraphism
Journal of Korean Neurosurgical Society 2021;64(2):143-150
Spinal dysraphism often causes neurological impairment from direct involvement of lesions or from cord tethering. The conus medullaris and lumbosacral roots are most vulnerable. Surgical intervention such as untethering surgery is indicated to minimize or prevent further neurological deficits. Because untethering surgery itself imposes risk of neural injury, intraoperative neurophysiological monitoring (IONM) is indicated to help surgeons to be guided during surgery and to improve functional outcome. Monitoring of electromyography (EMG), motor evoked potential, and bulbocavernosus reflex (BCR) is essential modalities in IONM for untethering. Sensory evoked potential can be also employed to further interpretation. In specific, free-running EMG and triggered EMG is of most utility to identify lumbosacral roots within the field of surgery and filum terminale or non-functioning cord can be also confirmed by absence of responses at higher intensity of stimulation. The sacral nervous system should be vigilantly monitored as pathophysiology of tethered cord syndrome affects the sacral function most and earliest. BCR monitoring can be readily applicable for sacral monitoring and has been shown to be useful for prediction of postoperative sacral dysfunction. Further research is guaranteed because current IONM methodology in spinal dysraphism is still deficient of quantitative and objective evaluation and fails to directly measure the sacral autonomic nervous system.
3.Diagnosis and management of muscle pain.
Journal of the Korean Medical Association 2013;56(2):120-126
Muscle pain is one of the most common, as well as elusive, clinical complaints. Pain can be experienced in muscles by any dysfunction of the muscle itself, peripheral nerves, or central nervous system. Persistent inflammation of the muscle increases nerve endings of the nociceptors and can develop allodynia or hyperalgesia. Myofascial trigger points are formed by perpetuating contraction of the sarcomeres and local ischemia and can result in regional pain. Disorders of the peripheral nervous system can entail muscle pain in the innervated territory. The central nervous system can also modulate or generate muscle pain. Gate-control theory provides an explanation as to how pain can be affected by the nervous system. Fibromyalgia is believed to be related to a lowered pain threshold in the central nervous system. Clinicians, during their diagnostic approach, should not unduly attribute muscle pain to pathology confined to the muscle merely because pain is perceived and evoked from the muscle. Even in cases where abnormalities are confirmed in the muscle, such as myofascial trigger points, clinicians should seek the underlying etiology. In particular, diagnosis of myofascial pain syndrome does not rule out primary musculoskeletal disorders. Rather, arthropathies or radiculopathies are known to frequently involve myofascial pain syndrome, which would not improve unless they are resolved. After accurate diagnosis of muscle pain is obtained, appropriate treatment should be implemented. A multi-disciplinary, individualized approach, including physiotherapy, exercise, education, and behavioral modification, is recommended.
Central Nervous System
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Contracts
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Fibromyalgia
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Hyperalgesia
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Inflammation
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Ischemia
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Muscles
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Myofascial Pain Syndromes
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Nerve Endings
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Nervous System
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Nociceptors
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Pain Threshold
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Peripheral Nerves
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Peripheral Nervous System
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Radiculopathy
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Sarcomeres
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Trigger Points
4.Recalcitrant Low Back Pain Diagnosed as Hypophosphatemic Osteomalacia Induced by Antiviral Medication
Hyun Jun CHAE ; Jun Hee WON ; Won Kyung LEE ; Keewon KIM
Clinical Pain 2021;20(2):131-134
We report a rare case of anti-viral agent induced hypophosphatemic osteomalacia presented with localized and radicular pain. A 51-year-old man, who had been taking adefovir for chronic hepatitis, had experienced low back pain radiating to his right thigh for 2 years. With impression of lumbar disc herniation, he underwent magnetic resonance imaging and found multi-level disc herniation with facet joint synovial cysts. He received transforaminal epidural steroid injections, however, symptoms did not improve. To find other possible causes, additional tests were performed. Blood tests revealed hypophosphatemia and increased serum alkaline phosphatase, and osteoporosis was noted in dual-energy X-ray absorptiometry with multiple hot uptakes in bone scan. After replacement of adefovir to entecavir and supplement of phosphate and vitamin D, phosphate level and the clinical symptoms were improved. This is the first to report the presentation of osteomalacia due to anti-viral agent as radicular low back pain with facet synovial cysts.
5.Biological Pathway Extension Using Microarray Gene Expression Data.
Tae Su CHUNG ; Jihun KIM ; Keewon KIM ; Ju Han KIM
Genomics & Informatics 2008;6(4):202-209
Biological pathways are known as collections of knowledge of certain biological processes. Although knowledge about a pathway is quite significant to further analysis, it covers only tiny portion of genes that exists. In this paper, we suggest a model to extend each individual pathway using a microarray expression data based on the known knowledge about the pathway. We take the Rosetta compendium dataset to extend pathways of Saccharomyces cerevisiae obtained from KEGG (Kyoto Encyclopedia of genes and genomes) database. Before applying our model, we verify the underlying assumption that microarray data reflect the interactive knowledge from pathway, and we evaluate our scoring system by introducing performance function. In the last step, we validate proposed candidates with the help of another type of biological information. We introduced a pathway extending model using its intrinsic structure and microarray expression data. The model provides the suitable candidate genes for each single biological pathway to extend it.
Biological Processes
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Gene Expression
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Saccharomyces cerevisiae
6.Biomechanical Evaluation of the Capsular Stiffness and Clinical Features in Adhesive Capsulitis of Shoulders.
Keewon KIM ; Tae Uk KIM ; Ja Ho LEIGH ; Kyu Jin LEE ; Hee Chan KIM ; Sun Gun CHUNG
Journal of the Korean Academy of Rehabilitation Medicine 2009;33(2):205-214
OBJECTIVE: To evaluate the capsular stiffness of the glenohumeral joint by measuring the slope of pressure-volume curves generated during intra-articular hydraulic distension (IHD) and analyze its correlation with clinical variables and outcomes in terms of limitation of range of motion (LOM) and severity of pain. METHOD: IHD with real-time intra-articular pressure monitoring was performed for 53 patients with adhesive capsulitis and the capsular stiffness was measured from pressure-volume curves by calculating the slope of elastic deformation region. LOM, measured by LOM score and sum of ROMs (range of motion), and degree of pain, measured by visual analog scale (VAS), were evaluated before and after IHD: three days (3D) and one month (1M) after IHD. RESULTS: In patients with stiffer capsules, LOM and pain were severe before IHD (Pearson's correlation coefficient (r)= 0.291, -0.348, 0.381 and p=0.065, 0.026, 0.014 for LOM score, sum of ROMs and VAS, respectively. By this order, henceforth). On 3D follow up, the correlation between the stiffness and LOM or pain was maintained (r=0.291, -0.348, 0.381 and p=0.065, 0.026, 0.014). The improvement of LOM score on 3D follow up was less as the capsules were stiffer (r=-0.368, p=0.023). On 1M follow up, LOM remained severer in stiffer capsules whereas pain did not (r=0.372, -0.402, 0.183 and p=0.039, 0.025, 0.342). CONCLUSION: The stiffness of the glenohumeral joint capsule, measured from the slope of pressure-volume curves during IHD, showed significant correlation with the severity of LOM and pain in patients with adhesive capsulitis of shoulder.
Adhesives
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Bursitis
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Capsules
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Follow-Up Studies
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Humans
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Range of Motion, Articular
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Shoulder
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Shoulder Joint
7.A Dynamic Magnetic Resonance Imaging Study of Changes in Severity of Cervical Spinal Stenosis in Flexion and Extension.
Yookyung LEE ; Seung Yeun KIM ; Keewon KIM
Annals of Rehabilitation Medicine 2018;42(4):584-590
OBJECTIVE: To evaluate changes in the severity of cervical spinal stenosis (CSS) in flexion and extension and determine whether the rate of change with motion varied with severity. METHODS: The study included 92 symptomatic patients with a mean age of 57.80±10.41, who underwent cervical spine dynamic magnetic resonance imaging. The severity of stenosis was evaluated using a semi-quantitative CSS score, ranging from 0 (no spinal stenosis) to 18 (severe stenosis). Radiological evaluation included flexion, neutral, and extension measurements, as determined by the C2–C7 Cobb angle. The severity of stenosis was represented by the total CSS score. The total CSS score in flexion, neutral, and extension positions was compared using repeated measures one-way analysis of variance. The change rate of stenosis per angle motion (CRSPAM) was defined as change in total CSS score divided by change in Cobb angle. The correlation of CRSPAM with severity of stenosis, represented by total CSS score in neutral position, was evaluated using Pearson correlation analysis. RESULTS: The total CSS score was significantly higher in extension (6.04±2.68) than in neutral position (5.25±2.47) (p < 0.001), and significantly higher in neutral than in flexion position (4.40±2.45) (p < 0.001). The CRSPAM was significantly and positively correlated with total CSS score in neutral position in the flexion-extension range (r=0.22, p=0.04) and flexion-neutral range (r=0.27, p=0.01). CONCLUSION: In symptomatic CSS patients, the radiological severity of stenosis increases with extension and decreases with flexion. In patients with CSS, the rate of variation in spinal stenosis increases with increased severity.
Cervical Vertebrae
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Constriction, Pathologic
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Female
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Humans
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Magnetic Resonance Imaging*
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Spinal Stenosis*
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Spine
8.Convolutional Neural Network Technology in Endoscopic Imaging: Artificial Intelligence for Endoscopy
Joonmyeong CHOI ; Keewon SHIN ; Jinhoon JUNG ; Hyun-Jin BAE ; Do Hoon KIM ; Jeong-Sik BYEON ; Namku KIM
Clinical Endoscopy 2020;53(2):117-126
Recently, significant improvements have been made in artificial intelligence. The artificial neural network was introduced in the 1950s. However, because of the low computing power and insufficient datasets available at that time, artificial neural networks suffered from overfitting and vanishing gradient problems for training deep networks. This concept has become more promising owing to the enhanced big data processing capability, improvement in computing power with parallel processing units, and new algorithms for deep neural networks, which are becoming increasingly successful and attracting interest in many domains, including computer vision, speech recognition, and natural language processing. Recent studies in this technology augur well for medical and healthcare applications, especially in endoscopic imaging. This paper provides perspectives on the history, development, applications, and challenges of deep-learning technology.
9.A Case of Carbamazepine-Induced Peripheral Neuropathy.
Sang Yoon LEE ; Eun Sil KOH ; Keewon KIM ; Se Hee JUNG
Journal of Korean Epilepsy Society 2009;13(1):27-30
Peripheral neuropathy is rarely caused by antiepileptic drugs andmost cases were reported about phenytoin. Here we report carbamazepine- induced peripheral neuropathy, which is a very rare condition and the pathogenesis is not well understood. A 19-year-old man presented with a several-year history of bilateral foot pain and pes planus. He had craniopharyngioma and underwent neurosurgery in 1997 and 2007. He had been prescribed by the general dose (600 mg/day) of carbamazepine since 1998 for the treatment of postoperative epilepsy. His muscle power was normal in all limbs and there were no abnormal sensory symptom and sign. Findings of electrodiagnostic studies were compatible with sensorimotor polyneuropathy with mixed axonotmesis and demyelination. His family history and genetic diagnosis excluded the possibility of hereditary neuropathy. After dose reduction of carbamazepine, his bilateral foot pain has been improved slowly. We report a case of carbamazepine-induced peripheral neuropathy.
Anticonvulsants
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Carbamazepine
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Craniopharyngioma
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Demyelinating Diseases
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Epilepsy
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Extremities
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Flatfoot
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Foot
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Humans
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Muscles
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Neurosurgery
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Peripheral Nervous System Diseases
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Phenytoin
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Polyneuropathies
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Young Adult
10.K-means Cluster Analysis on Care Status of Injured Workers with Stroke According to Discharge Disposition Patterns.
Goo Joo LEE ; Byung Mo OH ; Keewon KIM ; Sang Yoon LEE ; Sewoong CHUN ; Tai Ryoon HAN
Brain & Neurorehabilitation 2011;4(2):132-136
OBJECTIVE: This study aimed to characterize the use of medical service and medical costs of each cluster categorized by its discharge disposition pattern. METHOD: Data extracted from Electronic Data Interchange database of Korea Workers' Compensation and Welfare Service was analyzed. Among those who suffered from industrial accidents from Jan 1, 2006 to Dec 31, 2006, 422 were stroke patients. We categorized the subjects into 2 groups using k-means cluster analysis according to the discharge disposition pattern. Demographic characteristics, days of treatment, medical cost, initially admitted medical institution and disease type were analyzed in each group. RESULTS: There was no difference between the 2 groups in age, sex, type of stroke (ischemic or hemorrhagic stroke) and initially admitted medical institution. However medical cost and days of treatment were significantly different between 2 groups. CONCLUSION: K-means cluster analysis according to transferring pattern revealed a distinct group with longer hospitalization and more medical cost in injured workers. Further study is necessary to find out the characteristics of this group.
Accidents, Occupational
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Cluster Analysis
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Electronics
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Electrons
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Hospitalization
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Humans
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Korea
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Stroke
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Workers' Compensation