• Journal of Korean Neurosurgical Society
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• v.53 no.1
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• pp.31-38
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• 2013

Objective : Asymptomatic patients show high degeneration prevalence at lumbar disc in previous literatures. Unfortunately, there are few Korean data, so the authors attempted to analyze the prevalence of disc degeneration in highly selective asymptomatic Korean subjects using MRI. Methods : We performed 3 T MRI sagittal scans from T12 to S1 on 102 asymptomatic subjects (50 men and 52 women) who visited our hospital between the ages of 14 and 82 years (mean age 46.3 years). All images were read independently by three observers (two neurosurgeons and one neuroradiologist) who were not given any information about the subjects. We classified grading for lumbar disc herniation (HN), annular fissure (AF), and nucleus degeneration (ND), using disc degeneration classification. Results : The prevalence of HN, AF, and ND were 81.4%, 76.1%, and 75.8% respectively. Almost all levels showed an age-related proportional tendency with some exceptions. Conclusion : In asymptomatic Korean subjects, the abnormal findings showed high prevalence of AF, ND, and extrusion. Especially in young ages, the authors found that bulging, protrusion, and AF showed high prevalence at L4/5 and L5/S1. And ND showed high prevalence at L5/S1. So, all lumbar disc degenerations are not pathologic, especially in children and adolescents.

• The Journal of Korea CHUNA Manual Medicine
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• v.2 no.1
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• pp.85-92
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• 2001

Objectives : To study the cervical lordosis and disc degeneration in neck pain patients with or without low back pain. Subjects. The study was composed of 57 neck pain patients with low back pain(LBP group) and 40 neck pain patients without low back pain(Non-LBP group). Methods : Radiographic measures of spinal lordosis(cervical and lumbar) and disc degeneration were collected, and statistically analyzed. Results: LBP group showed a significant increase in cervical lordotic angle as compared with Non-LBP group, whereas no significant change in cervical disc degeneration. A relationship was found between cervical and lumbar disc degeneration in LBP $group({\gamma}-0.3064)$. Conclusions : The findings from this study suggest that the curvature of the cervical spine is related to the subject's low back pain.

• Annals of Clinical Neurophysiology
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• v.4 no.1
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• pp.21-27
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• 2002

Background : Spatial analysis of EEG is a phenomenal assessment and not so informative for phase space and dynamic aspect of EEG data. In contrast, nonlinear EEG analysis attempts to characterize the dynamics of neural networks in the brain. We have analyzed the features of EEG nonlinearly in subjects with white matter change on brain MRI and compared the results with cognitive function in each. Methods : Digital EEG data were taken for 30 seconds in 9 subjects with white matter degeneration and in 5 healthy normal controls without white matter change on MRI. Then we analyzed them nonlinearly to calculate the correlation dimension(D2) using the MATLAB software. The cognitive function was assessed by 3MS(modified mini-mental state examination). The severity of white matter change was assessed by Scheltens scale. Results : The mean D2 value of normal control was greater than that of white matter degeneration group. The D2s of some channels were correlative with 3MS and degree of white matter degeneration significantly. Conclusions : nonlinear analysis of EEG can be used as one of adjuvant functional studies for prediction of cognitive impairment in subjects with white matter degeneration and subcortical white matter change can be influential on cognitive function and correlation dimension of EEG.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1981.05a
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• pp.37.2-38
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• 1981

Recently the efficacy of all ear drops in perforated tympanic membranes has been questioned and the safety of using the drugs intratympanically has been challanged. Many drugs not normally ototoxic when given systemically become ototoxic when administered via the middle ear. According to Stupp and others (1973) among neomycin, polymyxin-G, gentamycin, erythr omycin, tetracycline and penicillin, only penicillin was found to be free of toxic effects. The ototoxic antibiotics probably reach the inner ear by permeating the round window membrane, into the perilymph and then through Reissner's membrane to the endolymph. The main pathological changes are degeneration of stria vascularis, degeneration of sensory epithelia and degeneration of ganglion cells. We report with reference, a case of profound sensorineural deafness following the application of Terramycin powder intratympanically, in a 63 year old woman.

• Journal of Korean Neurosurgical Society
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• v.53 no.6
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• pp.323-330
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• 2013

Objective : To develop a simple, reproducible model of disc degeneration in rabbits through percutaneous annular puncture and to confirm the degree of degeneration over time. Methods : Fifteen New Zealand white rabbits (4 to 5 months old and weighing approximately 3 to 3.5 kg each) underwent annular puncture of the L2-L3, L3-L4, and L4-L5 discs. Rabbits were sacrificed at 4, 8, or 20 weeks after puncture. For a longitudinal study to assess changes in disc height over time, serial X-rays were performed at 0, 2, 4, 8, and 20 weeks for rabbits in the 20-week group. Upon sacrifice, the whole spinal column and discs were extracted and analyzed with magnetic resonance imaging (MRI), real time reverse transcriptase-polymerase chain reaction, and histological staining. Results : The X-rays showed a slow, progressive decrease in disc height over time. Significant disc space narrowing compared to preoperative disc height was observed during the time period (p<0.001). The MRI grade, aggrecan, and matrix metalloprotease-13 mRNA expression and hematoxylin and eosin/safranin O/anti-collagen II staining were consistently indicative of degeneration, supporting the results of the X-ray data. Conclusion : Percutaneous annular puncture resulted in slow, reproducible disc degeneration that was confirmed by radiology, biochemistry, and histology. This in vivo model can be used to study and evaluate the safety and efficacy of biologic treatments for degenerative disc disease.

• Journal of Veterinary Clinics
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• v.40 no.1
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• pp.38-43
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• 2023

This study compared the degree of disc degeneration of intervertebral disc between normal disc and disc disease using Magnetic Resonance images of tholacolumbar and lumbar vertebrae in dogs. The sample population consisted of 72 dogs and 188 intervertebral discs. These dogs were divided into four groups according to MRI criteria: normal, disc protrusion, disc extrusion, and fibrocartilaginous embolism. The Pfirrmann classification developed by Pfirrmann for use in human medicine was used to assess the degree of disc degeneration. Statistical analysis revealed that disc diseases had a significant difference in the degree of disc degeneration compared to normal discs in the intervertebral disc. Fibrocartilaginous embolism was found to have a relatively low disc degenerative change compared to two other disc disease groups, disc protrusion and disc extrusion. Disc degeneration in the disc extrusion group was slightly higher than that in the disc protrusion group, although the difference between the two groups was not statistically significant.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.9
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• pp.673-684
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• 2003

A degenerated differential pair has been widely used as a standard topology for digitally programmable CMOS VGAs. A variable degeneration resistor has been implemented using a resistor string or R-2R ladder with MOSFET switches. However, in the VGAs using these conventional methods, low-voltage and high-speed operation is very hard to achieve due to the dc voltage drop over the degeneration resistor. To overcome this problem a new variable degeneration resistor is proposed where the dc voltage drop is almost removed. Using the proposed gain control scheme, a low-voltage and high-speed CMOS VGA is designed. HSPICE simulation results using a 0.25${\mu}{\textrm}{m}$ CMOS process parameters show that the designed VGA provides a 3dB bandwidth of 360MHz and a 80dB gain control range in 2dB step. Gain errors are less than 0.4dB at 200MHz and less than l.4dB at 300MHz. The designed circuit consumes 10.8mA from a 2.5V supply and its die area is 1190${\mu}{\textrm}{m}$${\times}$360${\mu}{\textrm}{m}$.

• Clinics in Shoulder and Elbow
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• v.21 no.2
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• pp.67-74
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• 2018

Background: Fatty degeneration of rotator cuff is a well-known predictor of postoperative outcome. The purpose of this study was to evaluate the clinical features of rotator cuff tears involving subscapularis, and investigate whether fatty degeneration quantified from only the upper subscapularis correlates better with clinical outcomes than quantified from the whole subscapularis. Methods: We retrospectively analyzed 315 consecutive patients who underwent arthroscopic repair for rotator cuff tears involving subscapularis with a minimum follow-up of 1 year. Preoperative and postoperative visual analogue score for pain, range of motion and functional scores were assessed. Integrity of the repaired tendon was assessed at the 1-year follow-up with either magnetic resonance imaging or ultrasonography. Results: The mean Goutallier grade of whole cross-section was significantly lower than that of upper cross-section (1.59 vs. 1.71, p<0.05), but significantly higher than that of lower cross-section (1.59 vs. 1.01, p<0.05). In analysis of 37 re-tears, the occupancy of severe fatty degeneration in upper cross-section was 86.5%, which was significantly higher than that seen in whole cross-section (56.8%, p<0.05). We calculated the cut-off tear size for prediction of re-tears as 19.0 mm for retraction and 11.0 mm for superior-inferior. The cut-off Goutallier grade was 2.5 for both whole and upper cross-sections, but area under the curve was greater in the upper cross-section than the whole (0.911 vs. 0.807). Conclusions: As fatty degeneration of upper subscapularis demonstrated a more distinct spectrum than whole subscapularis, we suggest that measuring fatty degeneration of upper subscapularis can be a more useful method to predict clinical prognosis.

• Journal of Korean Neurosurgical Society
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• v.44 no.5
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• pp.327-333
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• 2008

Objective: The purpose of this study is to verify the usefulness of the rabbit model for disc degeneration study. Materials: The L1-L2, L2-L3, L3-L4. or L4-L5 lumbar intervertebral disc (IVD) of 9 mature male New Zealand White rabbits were injured by inserting a 16-gauge needle to a depth of 5 mm in the left anterolateral annulus fibrosus while leaving L5-L6 IVD uninjured. Three other rabbits also received intradiscal injections of rabbit disc cells transfected with adenovirus and bone morphogenetic protein-2 (ad-BMP-2) at L4-L5 in addition to injury by 16-gauge needle at the L1-L2 level. Using digitized radiographs, measurements of IVD height were made and analyzed by using the disc height index (DHI). Magnetic resonance imaging (MRI) scans of the injured discs, injected discs, and uninjured L5-L6 discs were performed at 15 weeks post surgery and compared with preoperative MRI scans. Results: All twelve rabbits showed consistent results of disc degeneration within 15 weeks following annular puncture. DHIs of injured discs were significantly lower than that of the uninjured L5-L6 discs (p<0.05). The mean value of disc degeneration grade of injured discs was significantly higher than that of uninjured discs (p<0.05). The injection of disc cell transfected with ad-BMP-2 did not induce disc regeneration at 15 weeks after injection. Conclusion: This study showed that the injured disc had a significant change in DHI on simple lateral radiograph and disc degeneration grade on MRI scans within 15 weeks in all rabbits. Rabbit annular puncture model can be useful as a disc degeneration model in vivo.

• Journal of Oral Medicine and Pain
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• v.9 no.1
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• pp.11-22
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• 1984

The authors administered KCN, NaF,AS2O3 orally to rabbits and caused acute and chronic poisoning, then studied the teeth, jaw bones, and other oral tissues histopathologically. The results were as follows : 1. There was no significant difference between acute poisoned group by NaF and control group. But, vasodilatation in the connective tissues, esepcially marginal area of jaw bone, atrophy and destrution of glandualr cells was observed. 2. Chronic poisoned group by NaF showed degeneration and thicking of subcutanece fibrosis ective tissues, atrophy and degeneration of subcutaneous connective tissues, atrophy and degeneration of muscle fibers, vasodilation of subcutaneous in bone cavities(lacunae), and degeneration of odotlblasts in pulp tissue. 3. Acute poisoned group by KCN showed almost similar appearances as control group, and chronic poisoned group showed hyperplasia of baal layer in epitheilium, degeneration of subcutaneous connective tissues, vasodilation and huperemia, severe hemorrhage of marginal area of jaw bone. hyperplasia of salivary gland ducts, but normal arrangement of muscle fibers and narrow bone carity(lacunae) due to active osteoblastic action, osteodentin were observed. 4. Acute poisoned group by AS2O3 showed degeneration of basal cell, atrophy of blood vessels in palatal muscosa. Chronic poisoned group showed irregular cell arrangement and degeneration, reduction of capillaries in palatal mucosa. Osteoclasts in jaw bone were observed. 5. In Masson's Trichrome and Van Gieson Staining, chronic poisoned group by NaF showed thicking and loosening of subcutaneous connective tissues. Hyperplasia of intermuscular connective tissue was observed in chronic poisoning by KCN and NaF. In PAS staining, negative reation in outer layer of palatalmucosa, positive reaction in keratin layer and mild reaction of basal layer in palate and tongue mucosa was observed.