1.Study on powdered eggshell as new bone substitute for use in craniofacial surgery.
Chang Shin YOON ; Rong Min BAEK ; Se Min BAEK
Journal of the Korean Society of Plastic and Reconstructive Surgeons 1998;25(8):1444-1450
The first successful bone transplantation carried out in 1688 by Van Meek'ren, a Dutch surgeon. The ideal bone substitute should be biocompatible, osteoinductive or at least osteoconductive, available in unlimited quantity, low cost and have satisfactory mechanical properties. To accomplish these goals, autografts are still preferred material. However, bone harvesting procedures have been focused to solve the following problems; necessity of a second surgical site, morbidity and potential deformity of the donor site, an increased operative time, donor availability limitations, and resorption of autogenic bone grafts.Ten adult white New Zealand rabbits, three, 10 mm in diameter, full layer skull defects were made in the frontoparietal bone. Two bone defects were filled with hydroxyapatite and powdered eggshell, the other defect was not filled(control). All animals were sacrified at 10 weeks, the specimens were examined macroscopically to test for graft mobility. The graft with surrounding bone was then harvested and studied by histology. The results were as follows: 1. Control: Bone regeneration occurred nearly complete. 2. Hydroxyapatite: Macroscopically - No encapsulation. Despite a gross delineation between implant and bone, imlant was firmly united to bone. Histology - Bony trabeculae surrounded by proliferated connective tissue are observed in the defect site and implant. Osteoblastic rimming is noted along the bone fragments 3. Powdered eggshell:Macroscopically - Grafted site was encapsulated by proliferated connective tissue and palpable softer than the surrounding bone. Histology - The presence of eggshell particles encapsulated by fibrous connective tissue. Partial bone regeneration from the defect margin was noticed, but the bone healing was never complete. In conclusion, the use of safe and inexpensive material is recommended for filling limited bone defects in non-weight bearing areas. The use of powdered eggshell for bone substitute may also be considered, after further studies, to access its long term stability, porosity and biocompatibility.
Adult
;
Animals
;
Autografts
;
Bone Regeneration
;
Bone Substitutes*
;
Bone Transplantation
;
Congenital Abnormalities
;
Connective Tissue
;
Durapatite
;
Humans
;
Operative Time
;
Osteoblasts
;
Porosity
;
Rabbits
;
Skull
;
Tissue Donors
;
Transplants
2.Clinical Implications of Bone Bruises on MRI in Acute Traumatic ACL or PCL Injury.
Sang Wook BAE ; Ho Yoon KWAK ; Chang Goo SHIM ; Baek Yong SONG ; Nam Hong CHOI ; Soo Geun YOU
The Journal of the Korean Orthopaedic Association 1999;34(1):83-88
PURPOSE: Bone bruises of patients with acute traumatic knee injuries, that are not found on simple radiograph, can be found on magnetic resonance imaging (MRI). The purpose of this study is to evaluate the frequency and locations of bone bruises on MRI in acute traumatic anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) injury. MATERIALS AND METHODS: 25 and 19 MRls, in which acute traumatic ACL and PCL injury was pre sent and there was no abnormality in simple radiograph, were reviewed. MRI was taken within 51 days of injury. A bone bruise was determined as a geographic and nonlinear area of signal loss on T1 images and increased signal intensity on T2 images involving the subcortical bone. RESULTS: In 16 patients with bone bruises and acute ACL injury, bone bruises were found in the lateral compartment of the knee in 15 (93.8%) patients. The most common area was the lateral tibial plateau (11 cases, 68.8%) and the second was lateral femoral condyle (9 cases, 56.3%). In 5 patients with bone bruises and acute PCL injury, bone bruises were found in the lateral compartment of the knee in all 5 (100%) patients. The most common area was lateral tibial plateau (4 cases, 80%) and the second was lateral femoral condyle (2 cases, 40%). CONCLUSIONS: In patients with acute traumatic ACL or PCL injuries the bone bruises are often found on the lateral compartment of the knee, especially lateral tibial plateau and lateral femoral condyle on MRI.
Anterior Cruciate Ligament
;
Contusions*
;
Humans
;
Knee
;
Knee Injuries
;
Magnetic Resonance Imaging*
;
Posterior Cruciate Ligament
3.Environment and Condition of Graduate Medical Education.
Chang Yup KIM ; Seok Jun YOON ; Han Ju BAEK ; Jug Gu LEE ; Seung Ho BAEK ; Su Kyung PARK ; Chul Woung KIM ; Ki Hyung CHUNG ; Hong Jun CHO
Korean Journal of Medical Education 1997;9(1):55-63
Educational evironment and condition strongly influence the quality of graduate medical education. However, in Korea educational environment of in-hospital graduate medical education and training has not been explored in details. To evaluate current situation, we investigated 1,859 graduate trainees(residents) by self-administered questionnaire from May to July in 1996. Major findings of the survey were as follows; 1. Major providers of education were senior trainees(46.7%), compared with other sources of training such as self-study(22.9%) and staff trainers(14.5%). 2. At hospitals with less than or equal to 500 beds, formal educational programs for training were more poorly developed than hospitals with more than 500 beds. Among them, weakness in programs of case conference, staff lecture and training in affiliated hospitals was more remarkable. 3. At small hospitals with less than or equal to 500 beds, satisfaction level of trainees on their training were lower than that of trained at hospitals with more than 500beds. Research, conference, discussion with senior residents, and outpatient care were more dissatisfactory in particular. 4. Significant barriers to ideal training were work overload(57.2%) and shortage of educational programs(19.0%). Most of trainees are not satisfied with environment and condition of their training programs. To improve the quality of graduate medical education which is closely related with health care quality in the near future, general environment of education such as work load and educational programs has to be reoriented.
Ambulatory Care
;
Education
;
Education, Medical, Graduate*
;
Korea
;
Quality of Health Care
;
Surveys and Questionnaires
4.Cellular Angiofibroma of the Perianal Space: MR Imaging and Pathologic Correlation.
Chang Kyu BAEK ; Joon Seok LIM ; Yoon Sung BAE
Journal of the Korean Society of Magnetic Resonance in Medicine 2011;15(3):262-266
A variety of benign and malignant tumor can occur in the perianal space. Among them, cellular angiofibroma is a rare tumor that belongs to fibroblastic/myofibroblastic tumors of the WHO classification, sometimes called as "angiomyofibroblastoma-like tumor". Cellular angiofibroma can be found at various anatomic sites such as the vulva, perineum, genital tract, and inguinal regions with approximately equal gender ratio. This tumor is usually a well-circumscribed mass showing isosignal intensity to muscle on T1-weighted images. On T2-weighted images, cellular angiofibroma may show as a mass with inhomogeneous signal intensity depending on amount of composed spindle cell, collagenous stroma, myxoid matrix, and fat tissue; however it is characterized by low signal intensity due to fibrous tissues. This highly vascular mass shows strong enhancement on post contrast images. Recommended treatment is simple local excision and no recurrence or metastasis have been reported up to date.
Angiofibroma
;
Collagen
;
Muscles
;
Neoplasm Metastasis
;
Perineum
;
Recurrence
;
Vulva
5.A Case of Virilizing Adrenal Cortical Tumor in Child.
Sung Yong KIM ; Tae Yoon KIM ; Moo Jun BAEK ; Moon Soo LEE ; Hyung Chul KIM ; Yong Sik MIN ; Dae Joong KIM ; Chang Ho KIM
Journal of the Korean Association of Pediatric Surgeons 1999;5(2):152-158
Adrenal cortical tumor is a rare disease both in adults and children. Most of these tumors are malignant and functional, especially in children, producing endocrine syndrome such as virilization, Cushing's syndrome, hyperaldosteronism or feminization. Recently, we experienced a case of adrenal cortical tumor in a 26 month-old boy who showed features of virilization. This case was diagnosed with typical hormonal findings and abdominal CT and confirmed by pathologic examinations. He was successfully treated with right adrenalectomy. We report a case of virilizing adrenal cortical tumor and review the literature.
Adrenalectomy
;
Adult
;
Child*
;
Child, Preschool
;
Cushing Syndrome
;
Feminization
;
Humans
;
Hyperaldosteronism
;
Male
;
Rare Diseases
;
Tomography, X-Ray Computed
;
Virilism
6.Pattern of Glaucomatous Optic Disc Damage in Primary Open-Angle Glaucoma.
Joon Hyun KIM ; Chang Eun BAEK ; Yoon Koo AHN ; Ki Bang UHM ; Chul HONG
Journal of the Korean Ophthalmological Society 1997;38(6):1037-1043
To identify the pattern of glaucomatous changes of the optic disc, the rim area to disc area ratio (RA/DA ratio) of 149 eyes (149 cases) with primary open-angle glaucoma (POAG) were measured and compared with that of 88 eyes (88 cases) of normal individuals. At all stages of the disease, glaucomatous rim loss was present in all sectors of the optic disc. The location of the most pronounced rim loss changed depending on the severity of the disease. In the early (RA/DA ratio > 61%; mean deviation(MD): -6.43+/-3.32dB) and medium (RA/DA ratio=41~60%; MD: -7.54+/-5.65dB) glaucoma subgroups, rim loss was found predominantly at the inferior temporal and superior temporal disc region. In the advanced glaucoma subgroup (RA/DA ratio=40~21%; MD: -18.27+/-8.40dB), the temporal horizontal disc region showed relatively marked rim loss. In the far advanced glaucoma subgroup (RA/DA ratio=20~0%; MD: -25.91+/-5.40dB), the rim remnants were located mainly in the nasal disc sector, with a larger rim portion in the upper nasal region than in the lower nasal region. These results indicate that generally in POAG, the loss of neuroretinal rim was found to start predominantly in the inferior temporal and superior temporal disc region, and then the temporal horizontal, the inferior nasal, and the superior nasal disc sectors followed.
Glaucoma
;
Glaucoma, Open-Angle*
;
Optic Disk
7.Percutaneous Radiofrequency Ablation for Benign Nodules of the Thyroid Gland.
Jung Hwan BAEK ; Hyun Jo JEONG ; Yoon Suk KIM ; Min Sook KWAK ; Hyun Chul RHIM ; Sun Hee CHANG
Journal of the Korean Radiological Society 2005;52(6):379-384
PURPOSE: We wanted to evaluate the efficacy and safety of using ultrasound guided percutaneous radiofrequency ablation for the benign nodules of the thyroid gland. MATERIALS AND METHODS: We studied 148 patients with benign thyroid nodules (200 total nodules) that were confirmed histopathologically, and we performed ultrasound guided radiofrequency ablation. The radiofrequency ablation was done 1 to 5 times per one nodule, and follow-up ultrasonography was performed one to nineteen months after the ablation procedures. The physical changes and the decrease of volume of the nodules were evaluated, and the complications related to radiofrequency ablation were observed. RESULTS: The mean initial nodule volume was 0.01-95.61 ml (mean; 6.83+/-SD of 10.63 ml) and the nodule volume after radiofrequency ablation was decreased to 0.00-46.56 ml (mean; 1.83+/-SD of 4.69 ml). The mean volume reduction rate was 73.2%. Reduction of more than 50% was noted in 90% of all cases. For 180 nodules (90%), the decrease was 50% or more, in 20 nodules (10%), the decrease was 49% or less. On gray-scale ultrasonogram obtained after ablation, the echogenicity of the nodules changed to darker, and on the doppler-sonogram, the vascular flow within the nodules disappeared in all cases. Most patients complained pain during or right after the procedure, but the pain was transient and subsided after medication. Two patients developed hoarseness that was improved in 1 week and 2 months, respectively. CONCLUSION: Sonoguided percutaneous radiofrequency ablation can be one of the treatments for benign nodules of the thyroid gland.
Catheter Ablation*
;
Follow-Up Studies
;
Hoarseness
;
Humans
;
Thyroid Gland*
;
Thyroid Nodule
;
Ultrasonography
8.The Regulation of Cyclooxygenase-2 Expressionby Interleukin-1beta in WISH cells.
Young Jin CHANG ; Yoon Ki PARK ; Suk Whan BAEK ; Young Ki LEE ; Dong Hyuk LEE ; Hyun Woo LEE
Korean Journal of Obstetrics and Gynecology 2001;44(8):1393-1400
OBJECTIVE: To determine of the regulation of cyclooxygenase-2 (COX-2) expression by Interleukin-1beta in WISH cells. METHODS: Amnion WISH cells were incubated in media containing increasing concentrations of IL-1beta or with various inhibitors. Increased COX-2 expression was determined by Western blot analysis with anti-COX-2 antibody. Concomitant measurements of culture media PGE2 were made by an enzyme immunoassay. RESULTS: The COX-2 and prostaglandin E2 production induced by IL-1beta increased in a dose- and time-dependent manner. One of the regulating factors that induced COX-2 by IL-1beta was protein kinase C (PKC). PKC inhibitor, Ro 31-8220 was pretreated and continued treating by IL-1beta. Then, PKC inhibitor completely blocked COX-2 protein induction by IL-1beta. In contrast, COX-2 induction by IL-1beta after pretreating PKC stimulator, phobol 12-myristate 13-acetate was potentiated with synergism. Another factor in controlling COX-2 protein induction was identified as phosphatidylinositol 3-kinase (PI 3K). COX-2 protein induction by IL-1beta after pretreating PI 3K inhibitors, wortmannin and LY294002 strongly increased. This kind of result reflected that PI 3K act as negative regulator. COX-2 induction by IL-1beta was known to be regulated in not only transcription step, but also translation step after performing experiment of actinomycin and cycloheximide treatment. CONCLUSION: COX-2 protein and prostaglandin E2 production induced by IL-1beta were controlled by many factors in amnion cell. Among those factors, PKC and PI 3K have an important role, but their control mechanism act as positive and negative, respectively.
Amnion
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Blotting, Western
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Culture Media
;
Cycloheximide
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Cyclooxygenase 2*
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Dactinomycin
;
Dinoprostone
;
Immunoenzyme Techniques
;
Interleukin-1beta*
;
Phosphatidylinositol 3-Kinase
;
Protein Kinase C
9.A Study of Subclinical Extension of Basal Cell Carcinoma by Mohs Micrographic Surgery.
Gwang Yeol JOH ; Jong Taik NAM ; Jung Ho YOON ; Ki Ho KIM ; Chung Hwan BAEK ; Hee Chang AHN ; Seok Kwun KIM
Annals of Dermatology 1995;7(2):127-133
BACKGROUND: Basal cell carcinoma(BCC) is the most common primary cutaneous neoplasm in Korea. Since the majority of BCCs occur on the head and neck and the goal of the BCC treatment is the complete removal of tumor, Mohs micrographic surgery is ideally suited for maximizing cure rate with minimizing tissue loss. OBJECTIVE: The purpose of this study is to evaluate the depth of excision as well as the lateral margins of BCC and to correlate these with the clinicopathologic aspects of the tumors. METHODS: Twenty patients with 21 BCCs (10 primary, 11 recurrent) diagnosed in the Department of Dermatology of Dong-A University Hospital from March, 1992 through December, 1993 were studied prospectively. RESULTS: 1. Sixty percent of tumors in primary BCCs in our series had a 2-mm maximal margin and 81.8% of recurrent BCC were eradicated with 4-mm or more lateral margin. 2. All the recurrent basal cell carcinomas (8 cases) measuring greater than 15-mm required more than 4-mm margin for the total removal. 3. More than 90% of BCC on the nose in our series required the removal of periosteum/perichondrium or the excision of whole layer. CONCLUSION: Mohs micrographic surgery is an appropriate tool to use in proposing guidelines for the treatment of skin cancer because the most accurate method of determining the actual extent of skin cancer can be achieved.
Carcinoma, Basal Cell*
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Dermatology
;
Head
;
Humans
;
Korea
;
Methods
;
Mohs Surgery*
;
Neck
;
Nose
;
Prospective Studies
;
Skin Neoplasms
10.Simultaneous Unwrapping Phase and Error Recovery from Inhomogeneity (SUPER) for Quantitative Susceptibility Mapping of the Human Brain
Young Joong YANG ; Jong Hyun YOON ; Hyun Man BAEK ; Chang Beom AHN
Investigative Magnetic Resonance Imaging 2018;22(1):37-49
PURPOSE: The effect of global inhomogeneity on quantitative susceptibility mapping (QSM) was investigated. A technique referred to as Simultaneous Unwrapping Phase with Error Recovery from inhomogeneity (SUPER) is suggested as a preprocessing to QSM to remove global field inhomogeneity-induced phase by polynomial fitting. MATERIALS AND METHODS: The effect of global inhomogeneity on QSM was investigated by numerical simulations. Three types of global inhomogeneity were added to the tissue susceptibility phase, and the root mean square error (RMSE) in the susceptibility map was evaluated. In-vivo QSM imaging with volunteers was carried out for 3.0T and 7.0T MRI systems to demonstrate the efficacy of the proposed method. RESULTS: The SUPER technique removed harmonic and non-harmonic global phases. Previously only the harmonic phase was removed by the background phase removal method. The global phase contained a non-harmonic phase due to various experimental and physiological causes, which degraded a susceptibility map. The RMSE in the susceptibility map increased under the influence of global inhomogeneity; while the error was consistent, irrespective of the global inhomogeneity, if the inhomogeneity was corrected by the SUPER technique. In-vivo QSM imaging with volunteers at 3.0T and 7.0T MRI systems showed better definition in small vascular structures and reduced fluctuation and non-uniformity in the frontal lobes, where field inhomogeneity was more severe. CONCLUSION: Correcting global inhomogeneity using the SUPER technique is an effective way to obtain an accurate susceptibility map on QSM method. Since the susceptibility variations are small quantities in the brain tissue, correction of the inhomogeneity is an essential element for obtaining an accurate QSM.
Brain
;
Frontal Lobe
;
Humans
;
Magnetic Resonance Imaging
;
Methods
;
Volunteers