1.Two Cases of Neonaal Renal Venous Thrombosis.
In One KIM ; Hae Il CHEONG ; Yong CHOI ; Kwang Wook KO ; Kyung Hoon PAEK ; Jung Sub KYONG ; Jun Ho LEE
Journal of the Korean Society of Pediatric Nephrology 1997;1(2):161-165
"To evaluate whether different qualifications of a cytologic diagnosis of atypical squamous cells of undetermined significance (ASCUS) predict a greater or lesser likelihood of tissue diagnosis of uterine cervix, we compared different cytologic qualifications of ASCUS with the tissue diagnosis. One hundred twenty-two con- secutive Papanicolaou smears showing ASCUS in women who had undergone cervical biopsy within nearest 30 days were collected. The 122 smears were qualified as ""favor reactive (25%), favor low grade squamous intraepithelial lesion (LSIL) (24%), favor squamous intraepithelial lesion (SIL) (16%), favor high grade squa- mous intraepithelial lesion (HSIL) (16%), and not otherwise specified (19%). Squamous intraepithelial or invasive lesion was pathologically confirmed by cervical biopsy in 13% of the favor reactive, 27% in favor LSIL, 70% in ""favor SIL, 75% in favor HSIL, and 35% in not otherwise specified smears. There were significant associations between the favor reactive smear and the benign biopsy finding and between the favor SIL smear and the biopsy showing a squamous intraepithelial or more severe lesion. Nevertheless, rnost of favor LSIL smears exhibit reactive process in tissue biopsy. Conclusively, qualified ASCUS stratifies women into different risk groups for SIL. The cytopathologist should make the cytologic diagnosis of ASCUS, favor LSIL circumspectly."
Biopsy
;
Cervix Uteri
;
Diagnosis
;
Female
;
Humans
;
Papanicolaou Test
;
Venous Thrombosis*
2.Cone-beam Reconstruction using Limited EPID Projections for Seeds Localization.
Jina CHANG ; Won Kyun JUNG ; Sung Ho PARK ; Kwang Ho CHEONG ; Tae Suk SUH
Korean Journal of Medical Physics 2008;19(3):186-190
In this study, we describe the preliminary application for the delineation of a metal object using cone-beam reconstruction (CBR) based on limited electronic portal imaging device (EPID) projections. A typical Feldkamp, Davis and Kress (FDK) reconstruction algorithm accompanying the edge preserving smoothing filter was used as only a few projections are acquired for reconstruction. In a correlation study of the projection numbers, we found that the size of the seeds and their location depicted by these CBR images were almost identical. Limited views were used for CBR, and our method is inexpensive and competitive for use in clinical applications.
Electronics
;
Electrons
;
Seeds
;
Statistics as Topic
3.The Effect of hATSC on Tactile Threshold in Neuropathic Pain Model in Rats.
Hae Kyu KIM ; Seong Wan BAIK ; Soon Ho CHEONG ; Kwang Rae CHO
Korean Journal of Anesthesiology 2004;47(1):106-111
BACKGROUND: Mesenchymal stem cells can be expanded rapidly in vitro and differentiated into multiple mesodermal cell types. This study was planned to isolate human adipose tissue stromal cells (hATSCs) from human liposuction tissues and to investigate the changes of tactile threshold after hATSC transplantation in animal neuropathic pain models. METHODS: hATSCs were grown under control conditions in alpha-MEM/10% FBS. To prepare neuropathic pain model rats, thirty male Sprague-Dawley rats that had the average body weight of 208 +/- 5 g, had an experimental nerve injury by cutting or clamping of sural and tibial nerves. The tactile threshold was measured by von Frey hair filament at preinjury and postoperative day (POD) 1, 2, 3, 7, 14. Transplantation of hATSCs was performed after measurement of tactile threshold at POD3. RESULTS: hATSCs grew as a monolayer of large, flat, and spindle-shaped cells. The tactile threshold after spared nerve injury was significantly decreased since one day after cutting or clamping of nerves (P < 0.01). The percent changes of a tactile threshold in clamping and hATSC group were decreased to 59.8 +/- 7.1% (POD7) and 52.6 +/- 5.1% (POD14) (P < 0.05). CONCLUSIONS: This results was suggested that hATSCs could be isolated from human adipose tissue easily. Althogh it needs more long-term investigation hATSCs might be used as a method of therapy for neuropathic pain.
Adipose Tissue
;
Animals
;
Body Weight
;
Constriction
;
Hair
;
Humans
;
Lipectomy
;
Male
;
Mesenchymal Stromal Cells
;
Mesoderm
;
Neuralgia*
;
Rats*
;
Rats, Sprague-Dawley
;
Stem Cells
;
Stromal Cells
;
Tibial Nerve
4.Intracellular trafficking and metabolic turnover of yeast prepro-alpha-factor-SRIF precursors in GH3 cells.
Myung Ae LEE ; Kwang Ho CHEONG ; Dennis SHIELDS ; Sang Dai PARK ; Seung Hwan HONG
Experimental & Molecular Medicine 2002;34(4):285-293
Chimeric genes coding for prepro region of yeast alpha-factor and anglerfish SRIF were expressed in rat GH3 cells to determine whether yeast signals could regulate hormone processing in mammalian cells. We report that nascent hybrid polypeptides were efficiently targeted to ER, where cleavage of signal peptides and core glycosylation occurred, and were localized mainly in Golgi. These data indicate that prepro region of yeast alpha-factor functions in sorting molecules to secretory pathway in mammalian cells. A hybrid construct with a mutated signal peptide underwent similar ER translocation, whereas such a mutation resulted in defective translocation in yeast (Cheong et al., 1997). This difference may be due to the differences in ER translocation between yeast and mammalian cells, i.e., posttranslational versus cotranslational translocation. Processing and secretion of metabolically labeled hybrid propeptides to mature SRIF peptides were assessed by HPLC. When pulse-labeled cells were chased for up to 2 h, intracellular propeptides disappeared with a half-life of approximately 25 min, showing that -68% of initially synthesized propeptides were secreted constitutively. About 22% of SRIF-related products were proteolytically processed to mature SRIF, of which 38.7% were stored intracellularly with a half-life of - 2 h. In addition, immunocytochemical localization showed that a small proportion of SRIF molecules accumulated in secretory vesicles. All these results suggest that yeast prepropeptide could direct hybrid precursors to translocate into ER lumen and transit through secretory pathway to the distal elements of Golgi compartment, but could process and target it less efficiently to downstream in rat endocrine cells.
Animals
;
Cell Line
;
Endoplasmic Reticulum/metabolism
;
Golgi Apparatus/metabolism
;
Kinetics
;
Peptides/genetics/*metabolism
;
Pituitary Gland, Anterior/*cytology
;
Protein Precursors/biosynthesis/genetics/*metabolism
;
*Protein Processing, Post-Translational
;
Protein Sorting Signals/genetics
;
Protein Transport
;
Rats
;
Recombinant Proteins/biosynthesis/metabolism
;
Retroviridae/genetics
;
Saccharomyces cerevisiae/genetics/*metabolism
;
Saccharomyces cerevisiae Proteins/biosynthesis/genetics/*metabolism
;
Secretory Vesicles/metabolism
;
Somatostatin/biosynthesis/genetics/metabolism/secretion
5.Intracellular trafficking and metabolic turnover of yeast prepro-alpha-factor-SRIF precursors in GH3 cells.
Myung Ae LEE ; Kwang Ho CHEONG ; Dennis SHIELDS ; Sang Dai PARK ; Seung Hwan HONG
Experimental & Molecular Medicine 2002;34(4):285-293
Chimeric genes coding for prepro region of yeast alpha-factor and anglerfish SRIF were expressed in rat GH3 cells to determine whether yeast signals could regulate hormone processing in mammalian cells. We report that nascent hybrid polypeptides were efficiently targeted to ER, where cleavage of signal peptides and core glycosylation occurred, and were localized mainly in Golgi. These data indicate that prepro region of yeast alpha-factor functions in sorting molecules to secretory pathway in mammalian cells. A hybrid construct with a mutated signal peptide underwent similar ER translocation, whereas such a mutation resulted in defective translocation in yeast (Cheong et al., 1997). This difference may be due to the differences in ER translocation between yeast and mammalian cells, i.e., posttranslational versus cotranslational translocation. Processing and secretion of metabolically labeled hybrid propeptides to mature SRIF peptides were assessed by HPLC. When pulse-labeled cells were chased for up to 2 h, intracellular propeptides disappeared with a half-life of approximately 25 min, showing that -68% of initially synthesized propeptides were secreted constitutively. About 22% of SRIF-related products were proteolytically processed to mature SRIF, of which 38.7% were stored intracellularly with a half-life of - 2 h. In addition, immunocytochemical localization showed that a small proportion of SRIF molecules accumulated in secretory vesicles. All these results suggest that yeast prepropeptide could direct hybrid precursors to translocate into ER lumen and transit through secretory pathway to the distal elements of Golgi compartment, but could process and target it less efficiently to downstream in rat endocrine cells.
Animals
;
Cell Line
;
Endoplasmic Reticulum/metabolism
;
Golgi Apparatus/metabolism
;
Kinetics
;
Peptides/genetics/*metabolism
;
Pituitary Gland, Anterior/*cytology
;
Protein Precursors/biosynthesis/genetics/*metabolism
;
*Protein Processing, Post-Translational
;
Protein Sorting Signals/genetics
;
Protein Transport
;
Rats
;
Recombinant Proteins/biosynthesis/metabolism
;
Retroviridae/genetics
;
Saccharomyces cerevisiae/genetics/*metabolism
;
Saccharomyces cerevisiae Proteins/biosynthesis/genetics/*metabolism
;
Secretory Vesicles/metabolism
;
Somatostatin/biosynthesis/genetics/metabolism/secretion
6.Monte Carlo Photon and Electron Dose Calculation Time Reduction Using Local Least Square Denoising Filters.
Kwang Ho CHEONG ; Tae Suk SUH ; Byung Chul CHO ; Hosang JIN
Korean Journal of Medical Physics 2005;16(3):138-147
The Monte Carlo method cannot have been used for routine treatment planning because of heavy time consumption for the acceptable accuracy. Since calculation time is proportional to particle histories, we can save time by decreasing the number of histories. However, a small number of histories can cause serious uncertainties. In this study, we proposed Monte Carlo dose computation time and uncertainty reduction method using specially designed filters and adaptive denoising process. Proposed algorithm was applied to 6 MV photon and 21 MeV electron dose calculations in homogeneous and heterogeneous phantoms. Filtering time was negligible comparing to Monte Carlo simulation time. The accuracy was improved dramatically in all situations and the simulation of 1% to 10% number of histories of benchmark in photon and electron dose calculation showed the most beneficial result. The empirical reduction of necessary histories was about a factor of ten to fifty from the result.
Monte Carlo Method
;
Uncertainty
7.Development of an Automatic Seed Marker Registration Algorithm Using CT and kV X-ray Images.
Kwang Ho CHEONG ; Byung Chul CHO ; Sei Kwon KANG ; Kyoung Joo KIM ; Hoon Sik BAE ; Tae Suk SUH
The Journal of the Korean Society for Therapeutic Radiology and Oncology 2007;25(1):54-61
PURPOSE: The purpose of this study is to develop a practical method for determining accurate marker positions for prostate cancer radiotherapy using CT images and kV x-ray images obtained from the use of the on-board imager (OBI). MATERIALS AND METHODS: Three gold seed markers were implanted into the reference position inside a prostate gland by a urologist. Multiple digital image processing techniques were used to determine seed marker position and the center-of-mass (COM) technique was employed to determine a representative reference seed marker position. A setup discrepancy can be estimated by comparing a computed COMOBI with the reference COMCT. A proposed algorithm was applied to a seed phantom and to four prostate cancer patients with seed implants treated in our clinic. RESULTS: In the phantom study, the calculated COMCT and COMOBI agreed with COMactual within a millimeter. The algorithm also could localize each seed marker correctly and calculated COMCT and COMOBI for all CT and kV x-ray image sets, respectively. Discrepancies of setup errors between 2D-2D matching results using the OBI application and results using the proposed algorithm were less than one millimeter for each axis. The setup error of each patient was in the range of 0.1+/-2.7~1.8+/-6.6 mm in the AP direction, 0.8+/-1.6~2.0+/-2.7 mm in the SI direction and -0.9+/-1.5~2.8+/-3.0 mm in the lateral direction, even though the setup error was quite patient dependent. CONCLUSION: As it took less than 10 seconds to evaluate a setup discrepancy, it can be helpful to reduce the setup correction time while minimizing subjective factors that may be user dependent. However, the on-line correction process should be integrated into the treatment machine control system for a more reliable procedure.
Axis, Cervical Vertebra
;
Humans
;
Prostate
;
Prostatic Neoplasms
;
Radiotherapy
8.Evaluation of Geometric Correspondence of kV X-ray Images, Electric Portal Images and Digitally Reconstructed Radiographic Images.
Kwang Ho CHEONG ; Kyoung Joo KIM ; Byung Chul CHO ; Sei Kwon KANG ; Ra Hyeong JUH ; Hoon Sik BAE ; Tae Suk SUH
Korean Journal of Medical Physics 2007;18(3):118-125
In this study we estimated a geometric correlation among digitally reconstructed radiographic image (DRRI), kV x-ray image (kVXI) from the On-Board Imager (OBI) and electric portal image (EPI). To verify geometric correspondence of DRRI, kVXI and EPI, specially designed phantom with indexed 6 ball bearings (BBs) were employed. After accurate setup of the phantom on a treatment couch using orthogonal EPIs, we acquired set of orthogonal kVXIs and EPIs then compared the absolute positions of the center of the BBs calculated at each phantom plane for kVXI and EPI respectively. We also checked matching result for obliquely incident beam (gantry angle of 315 degrees) after 2D-2D matching provided by OBI application. A reference EPI obtained after initial setup of the phantom was compared with 10 series of EPIs acquired after each 2D-2D matching. Imaginary setup errors were generated from -5 mm to 5 mm at each couch motion direction. Calculated positions of all center positions of the BBs at three different images were agreed with the actual points within a millimeter and each other. Calculated center positions of the BBs from the reference and obtained EPIs after 2D-2D matching agreed within a millimeter. We could tentatively conclude that the OBI system was mechanically quite reliable for image guided radiation therapy (IGRT) purpose.
Radiotherapy, Image-Guided
9.Gadolinium-enhanced Excretory MR Urography: Comparison with MR Urography Using HASTE Technique.
Gong Yong JIN ; Jeong Min LEE ; Young Min HAN ; Gyung Ho CHEONG ; Hee Sul OH ; Chong Soo KIM ; Sung Kwang PARK
Journal of the Korean Radiological Society 2000;42(1):137-143
PURPOSE: To compare the feasibility of gadolinium-enhanced excretory MR urography(GEMRU) and conven-tional MR urography using the half-Fourier acquisition single-shot turbo spin-echo(HASTE) sequence in pa-tients with hydronephrosis or non-visualized kidney. MATERIALS AND METHODS: Fifteen patients with hydronephrosis or non-visualized kidney, as demonstrated by ul-trasonography or intravenous urography, were enrolled in this study. Nine were men and six were women, and their age ranged from 18 to 77 (mean, 60.6) years. For all MR examinations, a 1.5-T MR unit was employed. For breath-hold MR urography, the HASTE technique(MRU) was used, and reconstruction involved the use of a maximum intensity-projection (MIP) algorithm. For gadolinium-enhanced excretory MR urography, the fast low angle shot(FLASH) 3-D method was used and images were obtained at 5, 10, 20, and 30 minutes, and recon-struction again involved the use of an MIP algorithm. In some cases, additional GEMRU was obtained 24 hours after contrast material injection, and an MIP algorithm was used for reconstruction. MRU and GEMRU were independently interpreted by two radiologists who for quantitative analysis compared SNR with CNR, and at each anatomic level qualitatively analysed morphologic accuracy and diagnostic value of the lesions. RESULTS: In quantitative analysis, SNR and CNR differences between the two sequences at the renal pelvis and the level of the ureter were not significant (p>0.05). In qualitative analysis, GEMRU was superior to M-RU for the assessment of evaluated ureter at each level(p<0.05), anatomic anomaly and intrinsic tumor. Ureteral stones, however, were more easily diagnosed with MRU. CONCLUSION: For assessment of the ureter GEMRU is superior to MRU and has the advantage of evaluating renal function. We believe that for evaluation of the urinary tract, especially the distal ureter, GEMRU may be a valuable adjunct to routine MR urography.
Female
;
Humans
;
Hydronephrosis
;
Kidney
;
Kidney Pelvis
;
Male
;
Ureter
;
Urinary Tract
;
Urography*
10.The Role of Camera-Based Coincidence Positron Emission Tomography in Nodal Staging of Non-Small Cell Lung Cancer.
Sun Min LEE ; Young Hwa CHOI ; Yoon Jung OH ; Seong Cheoll CHEONG ; Kwang Joo PARK ; Sung Chul HWANG ; Yi Hyeong LEE ; Chan H PARK ; Myung Ho HAHN
Tuberculosis and Respiratory Diseases 1999;47(5):642-649
BACKGROUND: It is very important to determine an accurate staging of the non-small cell lung cancer(NSCLC) for an assessment of operability and it's prognosis. However, it is difficult to evaluate tumor involvement of mediastinal lymph nodes accurately utilizing noninvasive imaging modalities. PET is one of the sensitive and specific imaging modality. Unfortunately PET is limited use because of prohibitive cost involved with it's operation. Recently hybrid SPECT/PET (single photon emission computed tomography/positron emission tomography) camera based PET imaging was introduced with relatively low cost. We evaluated the usefulness of coincidence detection (CoDe) PET in the detection of metastasis to the mediastinal lymph nodes in patients with NSCLC. METHODS: Twenty one patients with NSCLC were evaluated by CT or MRI and they were considered operable. CoDe PET was performed in all 21 patients prior to surgery. Tomographic slices of axial, coronal and sagittal planes were visually analysed. At surgery, mediastinal lymph nodes were removed and histological diagnosis was performed. CoDe PET findings were correlated with histological findings. RESULTS: Twenty of 21 primary tumor masses were detected by the CoDe PET. Thirteen of 21 patients was correctly diagnosed mediastinal lymph node metastasis by the CoDe PET. Pathological NO was 14 cases and the specificity of NO of CoDe PET was 64.3%. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of N1 node was 83.3%, 73.3%, 55.6%, 91.7%, and 76.2% respectively. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of N2 node was 60.0%, 87.5%, 60.0%, 87.5%, and 90.0% respectively. There were 3 false negative cases but the size of the 3 nodes were less than 1cm. The size of true positive nodes were 1.1cm, 1.0cm, 0.5cm respectively. There were 1 false positive among the 12 lymph nodes which were larger than 1cm. False positive cases consisted of 1 tuberculosis case, 1 pneumoconiosis case and 1 anthracosis case. CONCLUSION: CoDe PET has relatively high negative predictive value in the enlarged lymph node in staging of mediastinal nodes in patients with NSCLC. Therefore CoDe PET is useful in ruling out metastasis of enlarged N3 nodes. However, further study is needed including more number of patients in the future.
Anthracosis
;
Carcinoma, Non-Small-Cell Lung*
;
Diagnosis
;
Electrons*
;
Humans
;
Lung
;
Lymph Nodes
;
Magnetic Resonance Imaging
;
Neoplasm Metastasis
;
Pneumoconiosis
;
Positron-Emission Tomography*
;
Prognosis
;
Tuberculosis