1.Axisymmetric Contact Stress analysis of an Artificial Hip Joint of the Conical Fitting Type
Yong San YOON ; Young Yong KIM ; Kye Lim LEE ; Seung Key KIM ; Young Hoon KANG
The Journal of the Korean Orthopaedic Association 1989;24(6):1665-1672
The purpose of this study is to investigate the effect of the ball-cone contact interface variation on the ceramic ball stress which is the dominant factor of the design of the moldular artificial hip joint. A contact stress analysis problem is formulated using the optimization principle and finite element analysis technique on the ball-cone system of three dimensional axi-symmetrical model, Numerical procedure is employed to get the solution for varying angles of cones and angular mismatches between the ball and cone interfaces. There is a fair amount of friction in the interface and included in the analysis model.
Ceramics
;
Finite Element Analysis
;
Friction
;
Hip Joint
;
Hip
2.The Effect of Botulinum Toxin and Resiniferatoxin on the Detrusor Overactivity Induced by Cyclophosphamide in Rat Bladder.
San Wook KIM ; Kang Soo SHIM ; Jeong Gu LEE
Korean Journal of Urology 2006;47(1):47-54
PURPOSE: The purpose of this study was to compare the effects of resiniferatoxin (RTX) and botulinum toxin (BTX) on the bladder detrusor function in a cyclophosphamide (CYP)-induced cystitis rat model. MATERIALS AND METHODS: Sprague-Dawley rats were divided into 5 groups (1: saline treated, 2: CYP and BTX treated, 3: CYP and RTX treated, 4 and 5: CYP treated and sham operated as the counterpart of groups 2 and 3, respectively, with normal saline). 100mg/kg CYP was injected every third day for five weeks. Cystometrograms were performed after the BTX and RTX treatments. RESULTS: 1. The normal control group and the CYP-treated only group. In the CYP-treated group, the time of micturition frequency, the maximal detrusor pressure on the cystometergram (Pvesmax at CMG), the maximal detrusor pressure on the pressure-flow study (Pvesmax at pr/flow) and the episodes of irregular contractions were increased. 2. The CYP-only group and the CYP/BTX or CYP/RTXtreated groups. In the CYP/BTX or CYP/RTX treated groups, the time of micturition frequency, the Pvesmax at CMG, the Pvesmax at pr/flow and the episode of irregular contractions were decreased. 3. The CYP/BTXtreated group and the CYP/ RTXtreated group. There was no statistically significant difference between the two groups regarding micturition frequency, the PvesMax at CMG and the PvesMax at pr/flow, the Dhfo and the episodes of involuntary contractions (p>0.05). CONCLUSIONS: Intravesical administration of BTX or RTX blocked the CYP-induced detrusor overactivity as was shown by the restoration of the micturition frequency, the intravesical pressure and the involuntary contraction episodes to a control level. There was no statistically significant difference between the two groups regarding the urodynamic parameters.
Administration, Intravesical
;
Animals
;
Botulinum Toxins*
;
Cyclophosphamide*
;
Cystitis
;
Models, Animal
;
Rats*
;
Rats, Sprague-Dawley
;
Urinary Bladder*
;
Urination
;
Urodynamics
3.Clear Cell Sarcoma of the Kidney: A case in 39 year old man.
Hyun Ju YOO ; Yun Kyung KANG ; Mee JOO ; Hye Kyung LEE ; Dae Woo KIM ; Suk San PARK
Korean Journal of Pathology 1996;30(12):1138-1143
Clear cell sarcoma of kidney(CCSK) is a rare pediatric neoplasm characterized by a predominating component of clear cells, a predilection for metastases to bone, and a poor prognosis. The incidence of CCSK peaks during the 2nd year of life and adult cases are very rare. We report a case of CCSK encountered in the right kidney of a 39-year-old man. Grossly, it was a lobulated mass showing infiltrative margin, measured 7x5.5x5cm and had a homogeneous gray-tan color with a soft, fish-flesh consistency. Microscopically, about half of the tumor revealed the classic pattern of CCSK, having tumor cell cords or nests separated by the characteristic alveolar capillary networks. The tumor cells had clear pale cytoplasm, bland looking round nuclei and inconspicuous nucleoli. The other half showed the epithelioid-trabecular pattern forming pseudorosette or cord-like structures. Immunohistochemically, there was only a focal positive reaction to vimentin. Ultrastructurally, the tumor cells showed the primitive nephrogenic mesenchymal differentiation such as electron lucent cytoplasm, a small amount of organelles, scanty heterochromatin, inconspicuous nucleoli, and a lack of flocculant basal lamina material around the cytoplasmic membrane. We consider that this is a case of CCSK occuring in the oldest patient ever reported, confirmed by both immunohistochemistry and electron microscopy.
Adult
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Male
;
Female
;
Humans
;
Incidence
;
Neoplasm Metastasis
4.Comparison between the 5th and 6th American Joint Committee on Cancer (AJCC) Staging System in 1, 275 Breast Cancer Patients.
Young San JEON ; Su Hwan KANG ; Soo Jung LEE
Journal of the Korean Surgical Society 2004;67(3):175-182
PURPOSE: Since the publication of the 5th edition of the AJCC cancer staging manual in 1997 (old stage), significant developments have occurred in the field of breast cancer diagnosis and management; therefore, it was revised at 2002 (new stage). There are few reports comparing the changes in prognosis in relation to the changes in the staging system. The aims of this study were to evaluate the changes in patient distribution and prognosis according to the changes in the staging system and to elucidate the efficacy of new staging system. METHODS: The records of 1, 275 patients who underwent an operation for breast cancer at Yeung-Nam University Hospital between 1987 and 2003 were reviewed. The pathological stage was assigned retrospectively according to the 5th and the 6th AJCC staging criteria. The patient distributions by stage, nodal status, 5-year relapse free survival (RFSR) and overall survival rates (OSR) were retrospectively compared. RESULTS: Five hundred and five of 616 stage II patients according to the 1997 classification system were also stage II according to the 6th AJCC staging system. The number of patients with stages IIA and IIB decreased from 370 and 246 (old stage) to 342 and 165 (new stage), respectively. Conversely, the number of patients with stage III increased from 158 (old stage) to 271 (new stage). The five-year RFSR for patients with stage I, IIA, IIB, and IIIA were 94.2, 87.1, 74.3, and 48.8% according to the old stage (P<0.0001), and 95.2, 87.8, 81.7, and 66.8%, respectively, according to the new stage (P<0.0001). The five-year OSR for patients with stage I, IIA, IIB, and IIIA were 98.7, 94.3, 86.1, and 63.5% according to the old stage (P<0.0001), and 98.7, 95.7, 96.5, and 72.9%, respectively, according to the new stage (P<0.0001). The RFSR and OSR for stage IIIC were 42.0 and 59.5%, respectively. There was significant difference in the five-year OSR for stages IIB and IIIA (P=0.0308 and P=0.0132, respectively). CONCLUSION: In our study, the 6th AJCC staging system shifted poorer prognostic cohort of each stage toward a higher stage compared to the 1997 version. Therefore, the survival rate for any one stage assigned by 2002 staging system was also improved. In conclusion, it is imperative that careful attention is devoted to this effect so that accurate conclusions regarding the efficacy of new treatment can be drawn.
Breast Neoplasms*
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Breast*
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Classification
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Cohort Studies
;
Diagnosis
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Humans
;
Joints*
;
Neoplasm Staging
;
Prognosis
;
Publications
;
Recurrence
;
Retrospective Studies
;
Survival Rate
5.Docetaxel-induced Severe Fluid Retention in a Breast Cancer Patient: A Case Report.
Young San JEON ; Su Hwan KANG ; Soo Jung LEE
Journal of Breast Cancer 2010;13(2):231-235
Among many adverse effects of docetaxel, fluid retention is a well recognized, cumulative side effect, but severe fluid retention is rare. We report here on a case of docetaxel-induced severe fluid retention with peripheral edema, pleural effusion, severe ascites and pericardial effusion in a 41-year-old woman. She had been treated with 3 cycles of docetaxel 9 days previously and she was admitted to our hospital due to abdominal distention and mild dyspnea. Radiologic studies revealed pleural effusion, severe ascites and a small pericardial effusion. Diuretics were given for 21 days. The pleural effusion was resolved after treatment with diuretics for 2 days, but the ascites wasn't resolved until 14 days of diuretics. After treatment with diuretics for 21 days, all the symptoms of the patient were completely resolved. Early detection is mandatory and diuretics are very effective for patient suffering with docetaxel-induced severe fluid retention.
Adult
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Ascites
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Breast
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Breast Neoplasms
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Diuretics
;
Dyspnea
;
Edema
;
Female
;
Fluid Shifts
;
Humans
;
Pericardial Effusion
;
Pleural Effusion
;
Retention (Psychology)
;
Stress, Psychological
;
Taxoids
6.The Relationship of Height-Length Ratio of Foot and Resting Calcaneal Stance Position.
Bong Ok KIM ; San Kyong KANG ; Je Woon LEE
Journal of the Korean Academy of Rehabilitation Medicine 2002;26(5):591-597
OBJECTIVE: The purpose of this study was to know the correlation between resting calcaneal stance position (RCSP) and height-length (H/L) ratio of foot. METHOD: Both feet of 173 persons who visited the Department of Rehabilitation Medicine, Chungnam National University Hospital were included in the study. Their mean age was 23.6 years old. H/L ratio, RCSP and navicular angle of 346 feet were measured. All people were divided into 3 groups, such as, normal foot (-2degrees
Chungcheongnam-do
;
Foot*
;
Humans
;
Mechanics
;
Rehabilitation
7.Regional Lymph Node Metastasis in Papillary Thyroid Cancer.
Jae Hyun PARK ; Kang San LEE ; Keum Seok BAE ; Seong Joon KANG
Journal of Korean Thyroid Association 2014;7(2):129-135
Papillary thyroid cancer is a common endocrine cancer and commonly presents with lymph node metastases. It has been generally accepted that lymphatic drainage occurs from the thyroid primarily to the central lymphatic compartment and secondarily to the lateral compartment nodes. Recently, improvements in the resolution of imaging studies and the availability of highly sensitive thyroglobulin assays have highlighted the importance of identifying disease in the pre-operative assessment and dealing effectively with metastatic regional disease in order to prevent recurrence. However, there are limitations to diagnosing central lymph node metastases. With unreliable imaging modalities, prophylactic central lymph node dissection should be performed on all patients with papillary thyroid cancer. In comparison with the central compartment, prophylactic lateral node dissection has little or no effect on improving the prognosis of patients with papillary thyroid cancer. Therefore, lateral node dissection is recommended only as a part of the therapeutic procedure. The extension of lateral neck dissection is recommended a comprehensive selective neck dissection of levels IIa, III, IV, and Vb. The rich lymphatic supply of the thyroid gland coupled with the propensity for nodal metastases in papillary thyroid cancer require the modern thyroid surgeon to be familiar with the indications for and techniques of regional lymph node dissection.
Drainage
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Endocrine Gland Neoplasms
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Humans
;
Lymph Node Excision
;
Lymph Nodes*
;
Neck Dissection
;
Neoplasm Metastasis*
;
Prognosis
;
Recurrence
;
Thyroglobulin
;
Thyroid Gland
;
Thyroid Neoplasms*
8.Calcifying Aponeurotic Fibroma: An Atypical Case.
Soo Yong KANG ; Han Jun LEE ; Jae Sung LEE ; Jae Jun YANG ; Woo Young HWANG
Journal of the Korean Society for Surgery of the Hand 2010;15(2):83-87
Calcifying aponeurotic fibroma is a very rare benign soft tissue tumor with predilection for the fingers and palms of children and adolescents. We describe an unusual case of a calcifying aponeurotic fibroma in old age that circumferentially involved the dorsal and palmar side of the third metacarpal head.We performed a wide excision using two incisions, resulting in satisfactory clinical result. A calcifying aponeurotic fibroma must be considered in the differential diagnosis of a calcifying soft tissue lesion occuring in the hand of old age.
Adolescent
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Child
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Diagnosis, Differential
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Fibroma
;
Fingers
;
Hand
;
Humans
9.Current Trend of Robotic Thoracic and Cardiovascular Surgeries in Korea: Analysis of Seven-Year National Data.
Chang Hyun KANG ; Jin San BOK ; Na Rae LEE ; Young Tae KIM ; Seon Heui LEE ; Cheong LIM
The Korean Journal of Thoracic and Cardiovascular Surgery 2015;48(5):311-317
BACKGROUND: Robotic surgery is an alternative to minimally invasive surgery. The aim of this study was to report on current trends in robotic thoracic and cardiovascular surgical techniques in Korea. METHODS: Data from the National Evidence-based Healthcare Collaborating Agency (NECA) between January 2006 and June 2012 were used in this study, including a total of 932 cases of robotic surgeries reported to NECA. The annual trends in the case volume, indications for robotic surgery, and distribution by hospitals and surgeons were analyzed in this study. RESULTS: Of the 932 cases, 591 (63%) were thoracic operations and 340 (37%) were cardiac operations. The case number increased explosively in 2007 and 2008. However, the rate of increase regained a steady state after 2011. The main indications for robotic thoracic surgery were pulmonary disease (n=271, 46%), esophageal disease (n=199, 34%), and mediastinal disease (n=117, 20%). The main indications for robotic cardiac surgery were valvular heart disease (n=228, 67%), atrial septal defect (n=79, 23%), and cardiac myxoma (n=27, 8%). Robotic thoracic and cardiovascular surgeries were performed in 19 hospitals. Three large volume hospitals performed 94% of the case volume of robotic cardiac surgery and 74% of robotic thoracic surgery. Centralization of robotic operation was significantly (p<0.0001) more common in cardiac surgery than in thoracic surgery. A total of 39 surgeons performed robotic surgeries. However, only 27% of cardiac surgeons and 23% of thoracic surgeons performed more than 10 cases of robotic surgery. CONCLUSION: Trend analysis of robotic and cardiovascular operations demonstrated a gradual increase in the surgical volume in Korea. Meanwhile, centralization of surgical cases toward specific surgeons in specific hospitals was observed.
Adenosine-5'-(N-ethylcarboxamide)
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Delivery of Health Care
;
Esophageal Diseases
;
Heart Septal Defects, Atrial
;
Heart Valve Diseases
;
Korea*
;
Lung Diseases
;
Mediastinal Diseases
;
Myxoma
;
Robotics
;
Surgical Procedures, Minimally Invasive
;
Thoracic Surgery
10.Radiologic Analysis and Treatment of Posterior Malleolar Fractures of the Ankle.
Jae Sung LEE ; Soo Yong KANG ; Han Jun LEE ; Young Bong KO
Journal of the Korean Fracture Society 2009;22(2):98-103
PURPOSE: The purpose of this study was to classify posterior malleolar fractures according to the position of fragments and to analyze radiologic features of each type. MATERIALS AND METHODS: We analyzed forty-six patients of ankle fractures involving a posterior malleolus who were treated between January 2004 and December 2007. The posterior malleolar fractures were categorized into three types (posterolateral, posteromedial, shell) based on the major fracture line. In each type, we analyzed amount of displacement, involvement of articular surface, existence of subluxation and osteochondral impacted fragments. RESULTS: The forty-six patients were categorized into three types: Posterolateral (PL) type (33 cases, 72%), Posteromedial (PM) type (8 cases, 17%), shell type (5 cases, 11%). Of the 8 cases with PM type, 7 cases showed displacement more than Grade II, 4 cases showed subluxation of ankle joint, and 3 cases showed osteochondral impacted fragment. Average involvement of articular surface of PM type is 35% (15~65%). CONCLUSION: Posterior malleolar fractures with medial extension tended to have adverse effect on ankle stability and Preoperative CT scan is essential for evaluation of fracture type and determination of appropriate surgical approach.
Animals
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Ankle
;
Ankle Joint
;
Displacement (Psychology)
;
Humans