1.A Study on the radiosensitivity and chemosensitivity of YAC-1 Cell Line in Vitro.
Eui Hwan CHOI ; Kwang Joon KOH
Journal of Korean Academy of Oral and Maxillofacial Radiology 1997;27(1):43-53
The purpose of this study was to aid in the prediction of tumor cell tolerance to radiotherapy and/or chomotherapy . For this study, cell surviving curves were obtained for mouse lymphoma YAC-1 cell line using semiautomated MTT assay. 2, 4, 6, 8, 10Gy were irradiated at a dose rate of 210cGy/min using 60Co Irradiator ALDORADO 8. After irra diation, YAC-1 cell lines(3X10(4) cells/ml) were exposed to bleomycin or cisplatin for 1 hour. The viable cells were determined for each radiation dose and/or each concentration of drug at the 4th day. And they w ere compared to control values. The obtained results were as follows: 1. The surviving curve with gentle slope was obtained after irradiation of 2, 4, 6, 8, 10Gy on YAC-1 cell line. 2. The cytotoxicity of bleomycin or cisplatin was increased significantly at all concentration of 0.2microgram/ml, microgram/ml an d 20microgram/ml on YAC-1 cell line (P<0.01). 3. There were no significant differences of surviving fractions among 4Gy, 6Gy, and 8Gy after irradiation of each radia tion dose with 2microgram/ml of bleomycin compared with irradiation only on YAC-1 cell line(P<0.05). 5. There were significant differences of surviving fractions between the groups of irradiation only and the groups of i rradiation with 2microgram/ml of bleomycin or cisplatin at all doses of 2, 4, 6, 8 and 10Gy on YAC-1 cell line(P<0.05).
Animals
;
Bleomycin
;
Cell Line*
;
Cisplatin
;
Lymphoma
;
Mice
;
Radiation Tolerance*
;
Radiotherapy
2.A Case of Scleredema.
Eui Chul JEONG ; Kwang Ho CHOI ; Jae Hong KIM ; Joong Hwan KIM
Korean Journal of Dermatology 1985;23(5):658-661
Scleredema is a rare scleradematosis of unknown cause involving the face, neck, upper portion of the trunk, and proximal upper extremities. The clinical features of the disease are nonpitting indurated edema or stiffness of the neck, which may be sudden or insidious in onset. Diabetes mellitus and its complications have been frequently described to be associated with this disease. We present a case of scleredema developed on the nape, upper portion of the back and shoulder in 60-year-old man who had been suffered from diabetes mellitus for the past ten years.
Diabetes Mellitus
;
Edema
;
Humans
;
Middle Aged
;
Neck
;
Scleredema Adultorum*
;
Shoulder
;
Upper Extremity
3.A Biomechanical Study of Two Kinds of Tapered Pedicle Screws in Osteoporotic Lumber Spine.
Eui Chan JANG ; Jung Hwan SEO ; Kwang Sup SONG ; Ho Sung RYU
The Journal of the Korean Orthopaedic Association 1999;34(5):955-962
PURPOSE: To compare the pullout strength and insertion torque of proximally tapered screw (PT) with fully tapered screw (FT) and to investigate the correlation between the pullout strength and bone mineral density, morphology of pedicle, and insertion torque of the screw in osteoporotic lumbar spine. MATERIALS AND METHODS: Fifteen osteoporotic lumbar vertebrae from four white human cadavers were used. Bone mineral density, pullout strength and insertion torque were measured by dual energy x-ray absorptiometry, MTS and torque screw driver individually. RESULTS: The FT screw provided greater pullout force and insertion torque than the PT screw in 12 of 15 vertebrae tested (p<0.01). Pullout strength was correlated with insertion torque in PT (r=0.666, P=0.0006) and FT (r=0.464, P=0.19) screws. CONCLUSIONS: Results of this study indicate that the FT screws provide higher pullout strength and insertion torque than PT screws in osteoporotic lumbar spine and suggest that the development of tapered minor diameter may lead to an improved pedicle screw with high pullout strength and insertion torque. Nevertheless, further study is needed to investigate the effect of tapering the minor diameter on the mechanical bending strength of the screw.
Absorptiometry, Photon
;
Bone Density
;
Cadaver
;
Humans
;
Lumbar Vertebrae
;
Spine*
;
Torque
4.A Case of Verruciform Xanthoma Transformed from Lesions of Epidermal Nrvus Syndrome.
Hoon HUR ; Eui Chul JEONG ; Kwang Ho CHOI ; Jae Hoong KIM ; Joong Hwan KIM ; Kyung Soo LEE
Korean Journal of Dermatology 1986;24(1):145-149
We experienced a case of 16-year-old female with verruciform xanthoma transformed from lesions of epidermal nevus syndrome. The biopsy specimen of yellowish brown to red verrucous papule on the right buttock showed 1) uniform and verrucous acanthosis without cytological atypia, 2) parakeratosis and hyperkeratosis,3) variable foci of superficial necrosis with crusting and microabscess in the granular layer, 4) rete ridge elongation and papillomatosis, 5) characteristic foam cells located within the papillary dermis, but not below the rete ridges. Our case was diagnosed verruciform xanthoma by histopathologic finding which occured as a secondary development in lesions of epidermal nevus syndrome.
Adolescent
;
Biopsy
;
Buttocks
;
Dermis
;
Female
;
Foam Cells
;
Humans
;
Necrosis
;
Nevus
;
Papilloma
;
Parakeratosis
;
Xanthomatosis*
5.The Calcifying Epithelial Odonogenic Tumor: Report of a Case.
Seung Hyun LEE ; Eui Hwan KWANG ; Sang Rae LEE ; Mitsuo HOSAKA
Journal of Korean Academy of Oral and Maxillofacial Radiology 1998;28(2):521-537
The calcifying epithelial odontogenic tumor is a rare benign odontogenic neoplasm which was first described by Pindborg in 1955 and accounts for less than 1% of all odontogenic tumors. The tumor occurs primarily in the molar-premolar region of the mandible, and 52% of cases are associated with an unerupted tooth. The clinical feature is most commonly a slow-growing painless swelling. The tumor may show considerable radiographic variation and usually characteristic histopathologic features. In this study, we report a case of the calcifying epithelial odontogenic tumor on the left mandibular body and ramus area in a 28-year-old male with a brief review of the concerned literatures.
Adult
;
Humans
;
Male
;
Mandible
;
Odontogenic Tumors
;
Tooth, Unerupted
6.Effect of radiation dose variation on expression of caspase-3 in rat submandibular glands.
Ki Jeong KWON ; Yong Suk CHOI ; Eui Hwan HWANG ; Sang Rae LEE ; Kwang Joon KOH
Korean Journal of Oral and Maxillofacial Radiology 2006;36(1):7-15
PURPOSE: To investigate the caspase-3 expression in the acinar and ductal cells of rat submandibular glands after the irradiation of various doses. MATERIALS AND METHODS: The male Sprague-Dawley rats weighing approximately 250 gm were used for this study. The experimental group was irradiated with a single absorbed dose of 2, 5, 10, and 15 Gy on the head and neck region. The rats were sacrificed on the 1st, 3rd, 7th, 14th, 21st, and 28th day after irradiation. The specimens including the submandibular gland were sectioned and observed using histopathological and immunohistochemical methods. RESULTS: The local destruction of the acinar and ductal cells and the karyopyknotic nuclei of the acinar cells were observed in the 2 Gy and 5 Gy irradiation groups later than in the 10 Gy and 15 Gy irradiation groups. And the expression of caspase-3 was prominent only in the ductal cells in the 2 Gy and 5 Gy irradiation groups. CONCLUSION: This experiment suggests that radiation-induced apoptosis in the ductal cells of rat submandibular glands was induced by a low dose radiation associated with the activation of caspase-3 and radiation-induced necrosis was induced by a high dose radiation.
Acinar Cells
;
Animals
;
Apoptosis
;
Caspase 3*
;
Head
;
Humans
;
Male
;
Neck
;
Necrosis
;
Rats*
;
Rats, Sprague-Dawley
;
Submandibular Gland*
7.Percutaneous Vertebroplasty in the Treatment of Osteoporotic Compression Fracture (99 Patients, 171 Vertebral Bodies).
Chung Hwan KIM ; Hyung Sun AHN ; Jae Kwang HWANG ; Jung Suk SONG ; Eui Jung BAE
Journal of the Korean Fracture Society 2006;19(2):259-264
PURPOSE: This study was designed to compare the clinical and radiologic outcome of the patients who underwent percutaneous vertebroplasty among the groups based on follow-up period and BMD. MATERIALS AND METHODS: A total of 99 patients (171 vertebral bodies) underwent percutaneous vertebroplasty from January 2001 to September 2003. The patients were divided into 3 groups by follow-up periods, and also divided into 2 groups by BMD. We investigated the difference of radiologic and clinical effects among the groups. Radiologic findings was assessed as vertebral height restoration rate and rate of reduction loss by measurement of the height of vertebral body. The clinical outcomes were graded into 5. The statistical analysis was done using Chi-squire test and Independent-samples T test. RESULTS: Among the groups divided by follow-up period, there was no statistically significant difference of clinical and radiologic results except the rate of reduction loss between group I and group III (p>0.05). Between the groups divided by BMD, there was no statistically significant difference of clinical and radiologic results. CONCLUSION: Percutaneous vertebroplasty with bone cement for the osteoporotic compression fracture is an efficient procedure and considered as technique producing pleasurable clinical and radiologic results regardless of follow up-period and BMD.
Follow-Up Studies
;
Fractures, Compression*
;
Humans
;
Osteoporosis
;
Vertebroplasty*
8.Various retraction techniques for laparoscopic pancreaticoduodenectomy
Kwang Hyun KIM ; Eui Hyuk CHONG ; Incheon KANG ; Sung Hwan LEE ; Seok Jeong YANG
Journal of Minimally Invasive Surgery 2024;27(2):118-124
The laparoscopic pancreaticoduodenectomy (LPD), introduced by Gagner and Pomp in 1994, is typically done in high-volume centers due to its technical demands. Our methods aim to provide effective traction, enabling efficient surgery despite limited staffing. A retrospective analysis of 29 patients undergoing LPD by a single surgeon between September 2021 and December 2022 showed promising outcomes: median intraoperative bleeding of 425 mL, operation time of 505 minutes, and postoperative hospital stay of 10 days. With only one case requiring open conversion, our external retraction techniques demonstrate efficacy in overcoming challenges associated with manpower constraints, highlighting potential utility for surgeons in similar settings. We share LPD external retraction techniques and outcomes.
9.Guidelines for the Performance Evaluation of In-Vitro Diagnostic Test for the Detection of Norovirus Infection in Korea.
Jayoung KIM ; Hyun Soo KIM ; Sunwha LEE ; Seoung Hwan OH ; Kwang Sook WOO ; Seong Youl KIM ; Eui Kee MIN
Laboratory Medicine Online 2017;7(1):1-6
Norovirus is a leading cause of epidemic and sporadic acute gastroenteritis worldwide. Rapid and accurate detection of norovirus is essential for the prevention and control of norovirus outbreaks. The purpose of this study was to propose and develop a process for establishing appropriate standardized guidelines for the approval and evaluation of in vitro diagnostic medical devices (IVDD) for norovirus detection in Korea based on the related laws, regulations, and guidelines of USA, Europe, and Korea. We expect that this study could be used for diagnostic test standardization and the approval and evaluation of domestic norovirus diagnostic devices. We also expect the results will contribute to industrial expansion and public health promotion.
Diagnostic Tests, Routine*
;
Disease Outbreaks
;
Europe
;
Gastroenteritis
;
Jurisprudence
;
Korea*
;
Norovirus*
;
Public Health
;
Reagent Kits, Diagnostic
;
Social Control, Formal
10.Chromosome Aberrations and Sister-chromatid Exchanges in Workers Exposed to Mixed-organic Solvents in Shoe-making Workshops.
Jaechul SONG ; Soo Jin LEE ; Sang Chul ROH ; Soo Jung SOHN ; Hye Young OH ; Chang Hwan PARK ; Eui Sik HAN ; Kwang Won HA
Korean Journal of Aerospace and Environmental Medicine 1999;9(2):207-214
Chromosome aberrations and sister chromatid exchanges (SCEs) in lymphocytes of peropheral blood as an indicator which could evaluate the effects of mutagenicity after in human exposure to mixed-organic solvents were measured. This study was conducted using 33 shoe making workers occupationally exposed to organic solvents and 33 unexposed control. The results were as follows. 1. The mean air concentrations of n-hexane, toluene, ethyl acetate in working environment were 9.8-14.8, 31.7-45.4 and 4.4-7.6 ppm, respectively. 2. The frequencies of chromosome aberration in exposed workers to mixed-organic solvents and the unexposed were 1.12+/-1.24, 0.36+/-0.70, respectively and their differences were statistically significant (p<0.01). However, the SCE frequencies were not statistically significant between the both groups. 3. The frequencies of chromosome aberration and SCE were no statistically differences by sex, smoking and drinking.
Chromosome Aberrations*
;
Drinking
;
Education*
;
Humans
;
Lymphocytes
;
Occupations
;
Shoes
;
Sister Chromatid Exchange
;
Smoke
;
Smoking
;
Solvents*
;
Toluene