1.A clinical study on neck dissection in cases of head and neck cancer.
Hyuk Dong PARK ; Yoon Sang SHIM ; Kyung Kyoon OH ; Yong Sik LEE
Korean Journal of Otolaryngology - Head and Neck Surgery 1993;36(2):234-242
No abstract available.
Head and Neck Neoplasms*
;
Head*
;
Neck Dissection*
;
Neck*
2.Effect of Acute and Chronic Treatment with Risperidone on the Serotonin and Dopamine Receptors in the Rat Brain.
Yun Young CHOI ; Dae Hyuk MIIN ; Hye Kyung SON ; Chang Yoon KIM ; Chul LEE ; Hee Kyung LEE
Korean Journal of Nuclear Medicine 1997;31(1):9-18
The therapeutic efficacy of antipsychotic drugs is generally attributed to their ability to block dopamine D2 receptors. Classical D2 antagonists are not effective to treat negative symptoms and produce extrapyramidal side effects. On the other hand, atypical antipsychotic agents ameliorate negative symptoms without producing extra-pyramidal side effects, and it is reported to be associated with blockade of serotonin 5-HT2 receptors. The purpose of this study was to evaluate the effect of risperidone on neuroreceptors in the rat brain by quantitative autoradiography method. In acute treatment group, risperidone was injected into peritoneal cavity of male Wistar rats with dose of 0, 0.1, 0.25, 0.5, 1,0 and 2.0mg/kg in each Group(5/group), and they were decapitated after 2 hours. In chronic treatment group, risperidone was injected with dose of 0, 0.1, and 1mg/kg(I.P.) for 21 days and decapitated after 24 hours following last treatment. The effect of risperodone on the binding of [3H]spiperone to 5-HT2 and D2 receptors were analysed in 4 discrete regions of the striatum, nucleus accumbens, and frontal cortex by quantitative autoradiography. Acute treatment with risperidone reduced cortical 5-HT2 specific [3H]spiperone binding to 32% of vehicle-treated control. Subcortical 5-HT2 specific [3H]spiperone binding was not affected at all dose groups whereas a significant reduction (57%) in D2 specific [3H]spiperone binding was observed in risperidone treated group at doses of l-2mg/kg. Chronic treatment with risperidone produced a decrease in the maximal number of cortical 5-HT2 receptors to 51% and 46% of control in 0.1mg/kg & 1mg/kg treated group respectively. In conclusion, risperidone is a cortical serotonin receptor antagonist with relatively weak antagonistic action on dopamine receptors. These effects on neuroreceptors may explain the therapeutic effect of risperidone as a atypical antipsychotic agents.
Animals
;
Antipsychotic Agents
;
Autoradiography
;
Brain*
;
Dopamine*
;
Hand
;
Humans
;
Male
;
Nucleus Accumbens
;
Peritoneal Cavity
;
Rats*
;
Rats, Wistar
;
Receptors, Dopamine D2
;
Receptors, Dopamine*
;
Receptors, Serotonin, 5-HT2
;
Risperidone*
;
Sensory Receptor Cells
;
Serotonin*
3.Effect of deproteinized bovine bone mineral soaked in inorganic polyphosphate on bone regeneration.
Seong Yoon NA ; Joon Bong PARK ; Young Hyuk KWON ; Yeek HERR ; Jong Hyuk CHUNG
The Journal of the Korean Academy of Periodontology 2007;37(1):77-89
This study was performed to evaluate the effect of deproteinized bovine bone mineral soaked in inorganic polyphosphate on bone regeneration in the calvaria of rabbit in the procedure of guided bone regeneration with titanium reinforced expanded polytetrafluoroethylene(TR-ePTFE) membrane. The rabbits were divided into four groups. Control group used TR-ePTFE membrane filled with deproteinized bovine bone mineral, experimental group I used TR-ePTFE membrane and deproteinized bovine bone mineral soaked in 4% inorganic polyphosphate, experimental group II and III used TR-ePTFE membrane and deproteinized bovine bone mineral soaked in 8% or 16% inorganic polyphosphate respectively. After decortication in the calvaria, GBR procedure was performed on 8 rabbits with only TR-ePTFE membrane or titanium reinforced ePTFE membrane filled with deproteinized bovine bone mineral soaked in inorganic polyphosphate. The animals were sacrificed at 4 weeks, and 8 weeks after the surgery. Non-decalcified specimens were processed for histologic analysis, and new bone formation was assessed by histomorphometric as well as statical analysis. 1. Both control group and experimental group demonstrated increasing of new bone formation until 8weeks. 2. At 8 weeks, experimental group I and group II showed the significant difference compared to control group in new bone formation. Especially experimental group II showed the most increasing of new bone formation. 3. The higher concentration of inorganic polyphosphate filled, the more volume of bone formation promoted, but experimental group III did not reveal significant difference compared to contol group. 4. Deproteinized bovine bone mineral did not resorbed at all until 8 weeks. These results suggest that inorganic polyphosphate has a promoting effect on bone regeneration, possibly by enhancing osteoconductivity of the carrier and by increasing osteoinductivity of the defected alveolar bone tissue, but not as we respect.
Animals
;
Bone and Bones
;
Bone Regeneration*
;
Membranes
;
Osteogenesis
;
Rabbits
;
Skull
;
Titanium
4.Abdominal Aortic Pseudoaneurysm Caused by Lumbar Discectomy: Case Report.
Dong Hun KIM ; Sang Won YOON ; Kyung Seuk KIM ; Woo Hyuk KIM
Journal of the Korean Radiological Society 2003;48(1):91-93
Vascular injuries which occur during lumbar disk surgery, although rare, can give rise to potentially fatal complications which may be overlooked due to a broad range of clinical manifestations, and which surgeons and radiologists should be aware of. We report a recently encountered case of pseudoaneurysm of the abdominal aorta after lumbar disc surgery, and review the associated literature.
Aneurysm, False*
;
Aorta, Abdominal
;
Diskectomy*
;
Vascular System Injuries
5.The Change of Bone Metabolism in Ovariectomized Rats : Analyses of MicroCT Scan and Biochemical Markers of Bone Turnover.
Kyung Hyuk YOON ; Dae Chul CHO ; Song Hee YU ; Kyoung Tae KIM ; Younghoon JEON ; Joo Kyung SUNG
Journal of Korean Neurosurgical Society 2012;51(6):323-327
OBJECTIVE: The purpose of this study was to verify the appropriateness of ovariectomized rats as the osteoporosis animal model. METHODS: Twelve female Sprague-Dawley rats underwent a sham operation (the sham group) or bilateral ovariectomy [the ovariectomy (OVX) group]. Eight weeks after operations, serum biochemical markers of bone turnover were analyzed; osteocalcin and alkaline phosphatase, which are sensitive biochemical markers of bone formation, and C-terminal telopeptide fragment of type I collagen C-terminus (CTX), which is a sensitive biochemical marker of bone resorption. Bone histomorphometric parameters and microarchitectural properties of 4th lumbar vertebrae were determined by micro-computed tomographic (CT) scan. RESULTS: The OVX group showed on average 75.4% higher osteocalcin and 72.5% higher CTX levels than the sham group, indicating increased bone turnover. Micro-CT analysis showed significantly lower bone mineral density (BMD) (p=0.005) and cortical BMD (p=0.021) in the OVX group. Furthermore, the OVX group was found to have a significantly lower trabecular bone volume fraction (p=0.002). CONCLUSION: Our results showed that bone turnover was significantly increased and bone mass was significantly decreased 8 weeks after ovariectomy in rats. Thus, we propose that the ovariectomized rat model be considered a reproducible and reliable model of osteoporosis.
Alkaline Phosphatase
;
Animals
;
Biomarkers
;
Bone Density
;
Bone Resorption
;
Collagen Type I
;
Female
;
Humans
;
Lumbar Vertebrae
;
Osteocalcin
;
Osteogenesis
;
Osteoporosis
;
Ovariectomy
;
Rats
;
Rats, Sprague-Dawley
;
Salicylamides
;
X-Ray Microtomography
6.p53 Mutation and Epidermal Growth Factor Receptor Overexpression in Glioblastoma.
Kyung Sik YOON ; Min Cheol LEE ; Sam Suk KANG ; Jae Hyoo KIM ; Shin JUNG ; Yoon Ji KIM ; Jae Hyuk LEE ; Kyu Yoon AHN ; Ji Shin LEE ; Jong Yoon CHEON
Journal of Korean Medical Science 2001;16(4):481-488
Recent molecular studies indicate two different genetic pathways leading to the development of glioblastoma; final progression of astrocytoma and de novo formation. To define the mutual relationships of cytogenetic changes in the pathogenesis of glioblastoma, molecular histopathologic alterations of p53 and epidermal growth factor receptor (EGFR) were evaluated by single stranded conformational polymorphion, reverse transcriptase-polymerase chain reaction and immunohistochemical stains in 15 primary and 21 secondary glioblastomas. Mutations in p53 gene and positive immunoreactivity to p53 protein (DO1) were more prevalent in secondary glioblastomas than in primary glioblastomas. A correlation between p53 mutations and p53 immunopositivities in glioblastomas was observed in 83.3% of the cases. All cases with positive p53 immunoreactivities showed p53 mutations; however, 13.9% of glioblastomas with p53 immuno-positivities lacked the relevant mutations. EGFR amplifications were detected in 73.3% of primary glioblastomas and 9.5% of secondary glioblastomas (p<0.001). The concurrence of p53 mutation and EGFR amplification was revealed in only 2 out of 15 primary glioblastomas and none among the secondary glioblastomas. Immunoreactivities for EGFR were noted in 66.7% of primary glioblastomas and in 9.5% of secondary glioblastomas (p<0.001). A correlation between EGFR amplification and EGFR immunopositivity in glioblastomas was observed in 91.7% of the cases. These data indicate that EGFR amplification and p53 mutations are two independent genetic events in the development of glioblastomas.
Adolescence
;
Adult
;
Brain Neoplasms/*genetics/metabolism
;
Female
;
*Genes, p53
;
Glioblastoma/*genetics/metabolism
;
Human
;
Immunohistochemistry
;
Loss of Heterozygosity
;
Male
;
Middle Age
;
*Mutation
;
Protein p53/analysis
;
Receptor, Epidermal Growth Factor/analysis/*genetics
;
Reverse Transcriptase Polymerase Chain Reaction
7.Antiproliferative Effect of Lovastatin on Vascular Smooth Muscle Cell.
Seung Woo PARK ; Duk Kyung KIM ; Jeong Eun HUH ; Yoon Hyuk CHOI ; Yoon Ho CHOI ; Hyeon Cheol GWON ; June Soo KIM ; Sang Hoon LEE ; Kyung Pyo HONG ; Jeong Euy PARK ; Jung Don SEO ; Won Ro LEE
Korean Circulation Journal 1998;28(12):1981-1992
BACKGROUND AND OBJECTIVES: This study was performed to investigate the antiproliferative effect of lovastatin on vascular smooth muscle cell, especially to determine whether lovastatin induces apoptosis in vascular smooth muscle cell and the products of mevalonate pathway can reverse the antiproliferative effect of lovastatin. METHODS AND MATERIALS: Lovastatin only and lovastatin with one of the products of mevalonate pathway such as isopentenyl adenine, farnesol, mevalonate, cholesterol were added respectively in cultured rat vascular smooth muscle cells stimulated with 10% fetal calf serum. DNA synthesis was measured by tritiated-thymidine incorporation. Cell number was determined by hemocytometric counting. Cells were Giemsa-stained to evaluate morphological changes of apoptosis. Extracted DNA from the cells treated with lovastatin was assessed by gel electrophoresis. RESULTS: 1)Lovastatin inhibited DNA synthesis and cell proliferation in a dose-dependent manner. 2)The inhibitory effects of lovastatin could be reversed almost completely by mevalonate, partially by farnesol. 3)Lovastatin-treated vascular smooth muscle cells showed typical morphological changes of apoptosis. 4)A distinct ladder of DNA bands was visualized by gel electrophoresis of the DNA from the cells treated with lovastatin. CONCLUSION: Mevalonate metabolism is essential for vascular smooth muscle cell proliferation. The antiproliferative effect of lovastatin may result from the induction of apoptosis in vascular smooth muscle cells.
Adenine
;
Animals
;
Apoptosis
;
Cell Count
;
Cell Proliferation
;
Cholesterol
;
DNA
;
Electrophoresis
;
Farnesol
;
Lovastatin*
;
Metabolism
;
Mevalonic Acid
;
Muscle, Smooth, Vascular*
;
Rats
8.Effect of Dapagliflozin as an Add-on Therapy to Insulin on the Glycemic Variability in Subjects with Type 2 Diabetes Mellitus (DIVE): A Multicenter, Placebo-Controlled, Double-Blind, Randomized Study
Seung-Hwan LEE ; Kyung-Wan MIN ; Byung-Wan LEE ; In-Kyung JEONG ; Soon-Jib YOO ; Hyuk-Sang KWON ; Yoon-Hee CHOI ; Kun-Ho YOON
Diabetes & Metabolism Journal 2021;45(3):339-348
Glycemic variability is associated with the development of diabetic complications and hypoglycemia. However, the effect of sodium-glucose transporter 2 (SGLT2) inhibitors on glycemic variability is controversial. We aimed to examine the effect of dapagliflozin as an add-on therapy to insulin on the glycemic variability assessed using continuous glucose monitoring (CGM) in subjects with type 2 diabetes mellitus. In this multicenter, placebo-controlled, double-blind, randomized study, 84 subjects received 10 mg of dapagliflozin ( At week 12, significant reductions in glycosylated hemoglobin (−0.74%±0.66% vs. 0.01%±0.65%, Dapagliflozin effectively decreased glucose levels, but not glucose variability, after 12 weeks of treatment in participants with type 2 diabetes mellitus receiving insulin treatment. The role of SGLT2 inhibitors in glycemic variability warrants further investigations.
9.Effect of Dapagliflozin as an Add-on Therapy to Insulin on the Glycemic Variability in Subjects with Type 2 Diabetes Mellitus (DIVE): A Multicenter, Placebo-Controlled, Double-Blind, Randomized Study
Seung-Hwan LEE ; Kyung-Wan MIN ; Byung-Wan LEE ; In-Kyung JEONG ; Soon-Jib YOO ; Hyuk-Sang KWON ; Yoon-Hee CHOI ; Kun-Ho YOON
Diabetes & Metabolism Journal 2021;45(3):339-348
Glycemic variability is associated with the development of diabetic complications and hypoglycemia. However, the effect of sodium-glucose transporter 2 (SGLT2) inhibitors on glycemic variability is controversial. We aimed to examine the effect of dapagliflozin as an add-on therapy to insulin on the glycemic variability assessed using continuous glucose monitoring (CGM) in subjects with type 2 diabetes mellitus. In this multicenter, placebo-controlled, double-blind, randomized study, 84 subjects received 10 mg of dapagliflozin ( At week 12, significant reductions in glycosylated hemoglobin (−0.74%±0.66% vs. 0.01%±0.65%, Dapagliflozin effectively decreased glucose levels, but not glucose variability, after 12 weeks of treatment in participants with type 2 diabetes mellitus receiving insulin treatment. The role of SGLT2 inhibitors in glycemic variability warrants further investigations.
10.World Health Organization Grade II Oligodendroglioma Occurring after Successful Treatment for Childhood Acute Lymphoblastic Leukemia.
Sang In YOON ; Kyung Jae PARK ; Dong Hyuk PARK ; Shin Hyuk KANG ; Jung Yul PARK ; Yong Gu CHUNG
Brain Tumor Research and Treatment 2016;4(2):145-149
When treating childhood acute lymphoblastic leukemia (ALL), secondary neoplasms are a significant long term problem. Radiation is generally accepted to be a major cause of the development of secondary neoplasms. Following treatment for ALL, a variety of secondary tumors, including brain tumors, hematologic malignancies, sarcomas, thyroid cancers, and skin cancers have been reported. However, oligodendroglioma as a secondary neoplasm is extremely rare. Herein we present a case of secondary oligodendroglioma occurring 13 years after the end of ALL treatment.
Brain Neoplasms
;
Global Health*
;
Hematologic Neoplasms
;
Leukemia
;
Oligodendroglioma*
;
Precursor Cell Lymphoblastic Leukemia-Lymphoma*
;
Sarcoma
;
Skin Neoplasms
;
Thyroid Neoplasms
;
World Health Organization*