• Proceedings of the KOR-BRONCHOESO Conference
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• 1993.05a
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• pp.85-85
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• 1993

The clinical staging system for laryngeal cancers is not sufficient for prognosticator due to different biologic characteristics and their microenvironment according to primary sites. For determining the prognosticators, the authors peformed immunohistochemical staining to EGFR, p53 protein, and pRB in 40 cases of surgically treated squamous cell carcinomas of larynx in our institute during the past 5 years. The results are as followings; 1. The positive expression rate of p53 protein and negative expression rate of pRB showed correlations with clinical parameters. 2. The three-year survival rate for p53 protein positive cases was worse than the p53 protein negative cases. 3. Expression rate of EGFR was not correlated with the clinical parameters. As a conclusion, expression rates of p53 protein and pRB not only reflect well the biologic behavior of laryngeal cancer, but correlate closely with the tumor factors. Therefore they may be useful as the prognosticator to predict the malignant potency of laryngeal squamous cell carcinomas.

• Journal of the Korean Institute of Gas
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• v.25 no.5
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• pp.30-36
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• 2021

Residual life assessment of reformer tubes of mod HP steel used in the refinery and petrochemical industry were investigated by quantitative metallographic evaluation method. Area fractions of precipitated carbides were measured by using surface replication and its relationship with the remaining life of the tube was investigated. The microstructures of the virgin and other tubes were examined using optical microscopy (OM) for service periods of 1.8, 6.0, 7.2, 8.5, 9.7, and 16.2 years at 950 ℃ and the area fractions of the precipitates were measured by image analysis using ImageJ software. As the area fraction of the precipitates increased, the residual life was decreased accordingly. The results showed that the LMP was the highest in the virgin and the LMP decreased as the service time increased and the residual life decreased. A regressional equation showing the relation between the area fraction of carbides and LMP was experimentally derived. The obtained relationship can be used with the surface replication method for on-site residual life assessment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.399-401
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• 2022

A definitive diagnosis to classify the breast malignancy status may be achieved by microscopic analysis using surgical open biopsy. However, this procedure requires experts in the specializing of histopathological image analysis directing to time-consuming and high cost. To overcome these issues, deep learning is considered practically efficient to categorize breast cancer into benign and malignant from histopathological images in order to assist pathologists. This study presents a pre-trained convolutional neural network model architecture with a 100% fine-tuning scheme and Adagrad optimizer to classify the breast cancer histopathological images into benign and malignant using a 40× magnification BreaKHis dataset. The pre-trained architecture was constructed using the InceptionResNetV2 model to generate a modified InceptionResNetV2 by substituting the last layer with dense and dropout layers. The results by demonstrating training loss of 0.25%, training accuracy of 99.96%, validation loss of 3.10%, validation accuracy of 99.41%, test loss of 8.46%, and test accuracy of 98.75% indicated that the modified InceptionResNetV2 model is reliable to predict the breast malignancy type from histopathological images. Future works are necessary to focus on k-fold cross-validation, optimizer, model, hyperparameter optimization, and classification on 100×, 200×, and 400× magnification.

• Childhood Kidney Diseases
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• v.4 no.1
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• pp.17-24
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• 2000

Purpose: MCNS is found in approximately $85\%$ of the idiopathic nephrotic syndrome in children and shows good prognosis with initial steroid therapy. However in FSGS, there is poor prognosis with initial therapy and shows higher rate of progression to chronic renal failure and relapse after kindney transplantation. We have experienced 8 patients who were diagnosed as MCNS on initial renal biopsy and then progressed to FSGS on follow-up biopsy. So we have investigated their clinical course and risk factors for transition of MCNS to FSGS. Methods: We conducted a retrospective study with a review of histopathologic findings and clinical manifestations of 296 cases of MCNS and FSGS that were diagnosed from January 1988 to May 1999. We classified them into 3 groups according to the histopathologic finding; MCNS, FSGS, MCNS progressed to FSGS in follow-up biopsy. Results: The number of children was 296 cases comprising 241 cases($81.4\%$) showing MCNS, 8 cases($2.7\%$) transition group, 47 cases($15.9\%$) FSGS. The mean onset age was $6.0{\pm}2.6$years in MCNS, transition group $8.3{\pm}2.3$years, FSGS $7.2{\pm4.3$years, and the gender (M:F) ratio was 3.7:1 in MCNS, 3:1 in transition group, 1.8:1 in FSGS. Comparing the presence of initial hematuria, hypertension,24 hour urine protein, serum albumin, serum creatinine, there were significant difference between the transition group and the FSGS group in the following points; 24hour urine protein $684:342mg/m^2/hr$(P<0.05), serum albumin 1.92: 2.47g/dL(P<0.05), serum cholesterol 494:343mg/dL(P<0.05). Refractoriness to steroid therapy was 13.3$\%$ in MCNS. $12.5\%$ in transition group, $29.6\%$ in FSGS; significantly higher in FSGS(P<0.05). Immunosuppressant therapy was performed in $58.5\%$ of MCNS, $100\%$ in transition group, $80.8\%$ in FSGS; transition group showed significantly higher .ate(P<0.05) comparing with MCNS. Mean number of relapse and duration from onset to first relapse showed no significance difference between these groups. Conclusion: 249 patients with MCNS have been followed and $3.2\%$ (8 patients) of them has shown change in pathologic diagnosis from MCNS to FSCS. The risk factor for transition could not be found. Our results point to the need for a follow-up biopsy to certify the possibility of transition to FSCS in some MCNS cases with refractory cases to steroid therepy, frequent relapsing cases, or in case of no remission in spite of vigorous immunosuppressant therapy.

• Radiation Oncology Journal
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• v.12 no.1
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• pp.27-31
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• 1994

There are a number of reports suggesting that there may be a correlation between the clinical response to radiotherapy in various tumors and the clonogenic survival of cell lines derived from these tumors following exposure to 2 Gy(SF2). Authors conducted this study to determine SF2 for cells in primary culture from surgical specimens. The tumor tissues with squamous cell carcinoma of uterine cervix and head and neck were obtained. The tumor tissues were disaggregated to single cells by incubating with collagenase type w for 2 hours with constant stirring. Single cell suspensions were inoculated in four 24-well plates precoated with cell adhesive matrix. After 24 hours of incubation at 37$ ^{\circ}C $, rows of four wells were then irradiated, consisting of control set and five other sets each receiving doses of 1,2,3,4, and 6 Gy. After incubation for a total of 13 days, the cultures were stained with crystal violet and survival at each dose was determined by quantitative image analysis system, To determine whether cell growth was of epithelial origin, immunocytochemical staining with a mixture of cytokeratin and epithelial monoclonal antibodies were performed on cell cultures. During the period of this study, we received 5 squamous cell carcinoma specimens of head and neck and 20 of uterine cervical carcinoma. Of these, 15 yielded enough cells for radiosensitivity testing. This resulted an overall success rate of 60$ \% $. The mean SF2 value for 15 tumours was 0.55$\pm$0.17 ranging from 0.20 to 0.79. These results indicate that there is a broad range of sensitivities to radiation in same histologic type. So with a large patient population, we plan to determine whether a different SF2 value is associated with tumours that are controlled with radiotherapy than those that are not.

• Childhood Kidney Diseases
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• v.2 no.1
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• pp.26-33
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• 1998

This retrospective study was designed to evaluate the prognostic value and histologic correlation of sonography in childhood nephrotic syndrome. Sixty-nine patients with proteinuria over 2g per day at the time of presentation who were treated at the Korea University Hospital were included in this review. They were 1 to 15 years old(mean age, 7.8 years) with 49 males and 20 females. In each patient an ultrasound examination was done using SPA 1000(Diasonics, C.A., U.S.A.) on admission. Tissue specimens were obtained from 46 patients. The paraffin-embedded specimens were reviewed with special reference to interstitial edema, interstitial fibrosis, tubular atrophy, global sclerosis or inflammatory cell infiltrates. Biopsy proven renal disease were minimal change disease(n=20), focal segmental glomerulosclerosis(n=7), membranous glomerulonephritis(n=2), membranoproliferative glomerulonephritis(n=1), $Henoch-Sch\"{o}nlein$ purpura nephritis(n=6), IgA nephropathy(n=5), poststreptococcal glomerulonephritis(n=2), systemic lupus erythematosus(n=1) and Alport syndrome(n=2). There was a significant relationship between increased cortical echogenicity and global sclerosis or tubular atrophy(P<0.05). But no significant relationship was found between increased cortical echogenicity and interstitial fibrosis, interstitial edema, or inflammatory cell infiltration. In biopsy-proven primary nephrotic syndrome(n=30), no significant relationship was found between the increased conical echogenicity and the interstitial edema, interstitial fibrosis, global sclerosis, tubular atrophy or inflammatory cell infiltration. But there was a significant relationship between increased cortical echogenicity and resistance to corticosteroid (P<0.05). These results suggest that increased cortical echogenicity may be due to tubular atrophy or global sclerosis in patients with proteinuria and may be an effective indicator of resistance to corticosteroid in primary nephrotic syndrome.(J Korean Soc of Pediatr Nephrol 2:26-33, 1998)

• Tuberculosis and Respiratory Diseases
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• v.50 no.6
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• pp.676-685
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• 2001

Background : Angiogenesis is an essential component of tumor growth and metastasis, and the vascular endothelial growth factor (VEGF) is one of the most important angiogenic factors. Several solid tumors produce substantial amounts of VEGF, which stimulates proliferation and the migration of endothelial cells, thereby inducing neovasculization by a paracrine mechanism. To evaluate the prognostic roles of angiogenesis and VEGF expression in patients with non-small cell lung cancer, the relationship between VEGF expression in tumor tissues, the clinicopathologic features and the overall survival rate were analysed. Methods : Sixty-nine resected primary non-small cell lung cancer specimens were evaluated. The paraffin-embedded tumor tissues were stained by anti-VEGF polyclonal antibodies using an immunohistochemical method to assess VEGF expression. Results : In Forty-one patients (59%), the VEGF antigen was expressed weakly in their tumor tissue, whereas in twenty-eight patients (41%) the VEGF antigen was expressed strongly. The median survival time of the weak VEGF expression group was 24 months, and that of the strong VEGF expression group was 19 months. The three year-survival rates were 35%, 33%, respectively. The survival difference between both groups was not statistically significant. Conclusion : Although results were not statistically significant, the strong expression group tended to poorer prognosis than the weak expression group.

• Childhood Kidney Diseases
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• v.4 no.1
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• pp.48-56
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• 2000

Purpose: Alport SD., the most common herectitary rephriris, is a renal disease with rapid progression. Deafness, ocular abnormalities and a specific EM finding may be associated in addition to a family history. We have aralyged retrospectively. Methods: We observed 12 children with Alport syndrome who were diagnosed at Dept. of pediatrics in Kyunghee Univ., College of Medicine, from Apr. 1991 until Jun. 1999. We used four criteria for diagnosis: renal disease, family history, deafness or eye abnormalities, and a specific finding in electron microscopy Results: 2 of 12 patients had all features of the four diagnostic criteria. We could not trace an exact family history in 3 patients, and 6 patients did not exhibit deafness or eye abnormality. One could not have renal biopsy because offer chronic renal failure. Other three criteria were observed in her. The ratio of male to female observed was 1:2 respectively and the mean age of initial renal symptom was 5.6 years. 9 of 12 patients had a family history of renal disease. In the audiogram and ocular examination for 11 of 12 cases, sensorineural hearing loss was observed in 6 and ocular abnormality in 2 cases. In electron microscopic finding, irregular thickness of the capillary basement membranes with lamination of lamina densa and foot process obliteration was noted in 9 of 11 and thin basement membrane with splitting and foot process obliteration was noted in the other 2. The mean period of follow-up was 3 6/12 years. And one patient developed the chronic renal failure until now and had kidney transplantation. Conclusion: For the diagnosis of Alport syndrome, the following four diagnostic criteria are very important : renal disease, family history, deafness or eye abnormalities, and a specific finding on electron microscopy. We expect that more patients can be detected through the analysis of these characteristics.

• Journal of the Korean Society for Nondestructive Testing
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• v.19 no.3
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• pp.180-188
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• 1999

The dynamic elastic properties of metal matrix composites were investigated by resonant ultrasound spectroscopy(RUS). The composites used in this study consisted of 2124 aluminum alloy reinforced with different concentrations of SiC particles. RUS can determine the nine independent elastic stiffness($C_{ij}$) for the orthorhombic symmetry on a small specimen simultaneously. The elastic constants were determined as a function of the volume fraction. A concept of effective aspect ratio. which combine the aspect ratio and the orientation of reinforcement. was used to calculate the initial moduli from Mori-Tanaka theory for the input of RUS minimization code. Young's moduli can be obtained from the measured stiffnesses. The results show that the elastic stiffness increases with increment of the particle content. The behavior of elastic stiffness indicates that the particle redistribution induced by the extrusion process enlarges the transversely isotropic symmetry as the fraction of reinforced particles increase. This relationship could be used for determination of the volume fractions of reinforcement as a potential tool of nondestructive material characterization.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.10
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• pp.1145-1153
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• 2011

The purpose of this study is to relieve the residual stress of Al6061 using cryogenic heat treatment. Experimental T6 and cryogenic heat treatments were carried out to define the convective heat-transfer coefficient, which was then applied in the finite-element method (FEM) to predict the residual stress. The predicted residual stress was compared with the residual stress measured by X-ray diffraction (XRD), and the results were in good agreement. The mechanical properties were estimated by measuring the electrical conductivity and hardness. In addition, the size and formation of the precipitations were observed by TEM and XRD analysis for both T6 and cryogenic heat treatments. The effects of the cryogenic heat treatment on the residual stress, mechanical properties, and precipitation of Al6061 alloys were thus confirmed.