1.A Clinical Study of Pediatric Myelodysplastic Syndrome: Application of International Prognostic Scoring System and the Review of the Korean Literature.
Hoon KOOK ; Chan Jong KIM ; Weon Sang YOON ; Na Eun RYU ; Kyoung Joong CHUNG ; Tai Ju HWANG
Journal of the Korean Cancer Association 2000;32(1):178-190
PURPOSE: Myelodysplastic syndrome (MDS) in children needs to be elucidated in terms of clinical characteristics, natural history, the most effective treatment and prognostic factors, as the disease is very rare and its definition and classification has not reached a consensus by many physician. This study was aimed to describe the characteristics and the disease courses of Korean children with MDS, and to analyze the usefulness of prognostic scoring systems in the prediction of transformation to acute myelogenous leukemia (AML) and overall survival among subgroups. MATERIALS AND METHODS: Fourteen children with MDS seen at Chonnam University Hospital and additional 59 patients identified by the review of Korean literature were evaluated to define clinical characteristics and disease courses. Kaplan-Meier (K-M) probability of leukemic transformation and overall survival were plotted. FAB subtypes, subgroups by Boumemouth Scoring System (BSS), and International Prognostic Scoring System (IPSS) risk groups were compared to predict transformation to AML and overall survival. RESULTS: The median age of 14 patients was 36.5 months. The sex ratio was 3.7:1 (M: F). The frequency of FAB subtypes in Korea was similar to that of other countries except for higher proportion of RA (37%). K-M 3-yr probability of AML transformation and survival for Korean patients were 54.7%, and 49.8%, respectively. Although FAB system, BMS and IPSS were all capable of discriminating subgroups in the prediction of AML transformation and survival, they did not reach the significant level possibly due to small number of patients assigned to each subgroup. CONCLUSION: The clinical characteristics of Korean children with MDS were not different from those of other countries. This study showed the high rate of AML transformation and poor survival in children with MDS.
Child
;
Classification
;
Consensus
;
Humans
;
Jeollanam-do
;
Korea
;
Leukemia, Myeloid, Acute
;
Myelodysplastic Syndromes*
;
Natural History
;
Prognosis
;
Sex Ratio
2.The Effect of Enucleation in Childhood on Orbital Volumetric Growth.
Kyoung Hoon KOOK ; Jung Bum CHOI ; Mi In ROH ; Sang Yeul LEE
Journal of the Korean Ophthalmological Society 2004;45(11):1790-1798
PURPOSE: To evaluate the effect on the growth rate of orbital volume of those who received enucleation or evisceration with or without implants, according to different sizes and operation periods. METHODS: The subjects comprised 47 patients who had previously undergone evisceration or enucleation. The volumes of both anophthalmic and normal orbit were measured from CT scans of patients and compared. The relationship between the orbital volume growth rate and the operation at young age with different size implants or operation without implants was evaluated. RESULTS: Five groups, divided by age at operation, were evaluated. Four groups comprising under 12 years of age, had a significant delay in orbital volume growth development (p<0.05). Three groups, divided by size of implants, were evaluated and 17 mm or smaller sized orbital implants showed significant orbital volume growth retardation (p<0.05) CONCLUSIONS: The effect of early enucleation on orbital volume growth should be considered in patients younger than 12 years old. Furthermore, during the operation, implants with sizes larger than 18mm should be used to prevent the retardation of orbital volume growth.
Anophthalmos
;
Child
;
Humans
;
Orbit*
;
Orbital Implants
;
Tomography, X-Ray Computed
3.Spinal epidural granulocytic sarcoma preceding acute myelogenous leukemia.
Hoon KOOK ; Tai Ju HWANG ; Kyoung CHOE ; Dong Wook YANG ; Jong Hee NAM ; Chang Soo PARK
Journal of Korean Medical Science 1992;7(3):291-296
A rare case of spinal epidural granulocytic sarcoma (GS) preceding acute myelogenous leukemia is described. A 10-year-old boy presented with lower leg weakness. The initial diagnosis was a histiocytic lymphoma, and he was treated accordingly. No evidence of bone marrow involvement was found at that time. The correct diagnosis of epidural GS was made possible in retrospect by using immunoperoxidase staining for lysozyme fourteen months later when the patient showed the full-blown features of leukemia. This rare tumor should be considered in the differential diagnosis of an epidural mass with cord compression in patients with or even without acute leukemia, because early diagnosis followed by appropriate combined chemotherapy and radiation may obviate surgical intervention and eventually prevent leukemic transformation.
Child
;
Epidural Neoplasms/*complications/pathology
;
Humans
;
Immunoenzyme Techniques
;
Leukemia, Myeloid/*complications/pathology
;
Leukemia, Myeloid, Acute/*complications/pathology
;
Male
;
Neoplasms, Second Primary
4.A Clinical Analysis of Neonatal Surgical Gastrointestinal Diseases in Daegu?Busan Area.
Seung Kook SON ; Jae Hong PARK ; Byung Ho CHOI ; Kwang Hae CHOI ; Kyoung Hoon LEE
Korean Journal of Pediatric Gastroenterology and Nutrition 2004;7(2):179-185
PURPOSE: Perinatal mortality rates have been used as a summary statistic for evaluating child health and medical status. Neonatal mortality rates have decreased over the past 30 years in Korea. To understand the current status of neonatal surgical gastrointestinal diseases in Daegu?Busan area, we have studied about neonatal gastrointestinal diseases with their clinical features, postoperative outcome, and mortality rates. METHODS: A clinical analysis on 202 neonates who underwent neonatal surgery from January 1996 to July 2003 at Pusan National University, Kyungpook National University, Youngnam University, and Daegu Catholic University was carried out. RESULTS: The main diseases of surgical conditions were anorectal malformation (23.8%), atresia/ stenosis of midgut (13.4%) and pyloric stenosis (13.4%). The male to female ratio was 2.8:1. Thirty-five cases (17.0%) had one or more associated anomalies including congenital heart disease, cryptoorchidism, hydronephrosis, and chromosomal anomaly. Twenty cases (10.0%) were diagnosed by antenatal ultrasound. Patients with esophageal atresia had the longest hospitalization for 54.6 days. Postoperative complications occurred in 18 cases (8.9%). The main postoperative complications were wound infection (3.5%) and anastomotic leakage (2.5%). Overall mortality was 5.9%. Diaphragmatic hernia showed the highest mortality rate (37.5%), and esophageal atresia (28.6%) and omphalocele (20.0%) were followed. CONCLUSION: The current status of neonatal surgical gastrointestinal diseases in Daegu?Busan area has improved because the disease categories are various, postoperative complications and mortality rates are decreased.
Anastomotic Leak
;
Busan
;
Child
;
Child Health
;
Constriction, Pathologic
;
Daegu
;
Esophageal Atresia
;
Female
;
Gastrointestinal Diseases*
;
Gyeongsangbuk-do
;
Heart Defects, Congenital
;
Hernia, Diaphragmatic
;
Hernia, Umbilical
;
Hospitalization
;
Humans
;
Hydronephrosis
;
Infant
;
Infant Mortality
;
Infant, Newborn
;
Korea
;
Male
;
Mortality
;
Perinatal Mortality
;
Postoperative Complications
;
Pyloric Stenosis
;
Ultrasonography
;
Wound Infection
5.Corneal Flap Thickness according to Suction Time of Microkeratome in Porcine Eye.
Koung Hoon KOOK ; Kyoung Yul SEO ; Moon J KIM ; Eung Kweon KIM
Journal of the Korean Ophthalmological Society 2002;43(7):1133-1137
PURPOSE: The purpose of this study is to investigate the effect of the suction time in forming the corneal flap with microkeratome on the corneal flap thickness. METHODS: Thirty porcine eyes were randomly assigned into 3 groups according to suction duration: group 1(10 sec), group 2(35 sec) and group 3(60 sec). The Hansatome microkeratome with 160 plate and a suction ring with 8.5mm diameter were used to create corneal flap. The thickness of central cornea was measured with automated ultrasound pachymeter before the procedure. And after making the flap, the remained corneal thickness was measured with the same method. Then, the difference between the two values was thought to be the corneal flap thickness. RESULTS: The mean corneal flap thickness in group1, 2, and 3 were 91.0+/-24.1 micromiter, 110.1+/-8.9 mu m and 127.2+/-6.1 mu m, respectively. The difference was significant among the three groups(p=0.010), and the longer suction duration made the flap thicker. CONCLUSIONS: These results suggest that in forming the corneal flap with microkeratome, the suction duration has an effect on the corneal flap thickness and an increase of suction duration makes the flap thicker in porcine eyes.
Cornea
;
Suction*
;
Ultrasonography
6.Ophthalmic Manifestations in Patients With Neurofibromatosis.
Jaesoon BANG ; Hong Seok YANG ; Jae Hong AHN ; Kyoung Hoon KOOK ; Yoon Hee CHANG
Journal of the Korean Ophthalmological Society 2008;49(11):1829-1838
PURPOSE: To report the ophthalmic manifestations of neurofibromatosis in Korea. METHODS: Ophthalmologic examinations were performed from November 2001 to January 2008 for 153 consecutive patients who were diagnosed with neurofibromatosis according to the diagnostic criteria for neurofibromatosis. A retrospective analysis was performed according to the medical records of these 153 patients. RESULTS: Seventy seven out of the 153 patients were men, 76 were women and the mean age was 20.44 +/- 14.34 years old. One hundred twelve were neurofibromatosis type 1 and six were neurofibromatosis type 2. Remained thirty five were segmental neurofibromatosis type 1. Ophthalmic manifestations of the neurofibromatosis type 1 were Lisch nodule (52.68%), high myopia (14.29%), plexiform neurofibroma in the orbit (4.46%), cafe au lait spots (4.46%) and optic glioma (3.58%). In the neurofibromatosis type 2, epiretinal membrane (33.33%) showed highest incidence and posterior subcapsular opacity (16.67%), Lisch nodule (16.67%), optic disc edema (16.67%), and optic nerve glioma (16.67%) were also noted. Lisch nodule (25.71%) was the most common ophthalmic finding in segmental neurofibromatosis type 1. CONCLUSIONS: Lisch nodule, which was the most common manifestation of the neurofibromatosis type 1, was less manifested in our cases compared to the previous reports of western countries. In the neurofibromatosis type 2, epiretinal membrane and posterior subcapsular cataract showed higher incidence than those of other types of neurofibromatosis.
Cafe-au-Lait Spots
;
Cataract
;
Edema
;
Epiretinal Membrane
;
Female
;
Humans
;
Incidence
;
Korea
;
Male
;
Medical Records
;
Myopia
;
Neurofibroma, Plexiform
;
Neurofibromatoses
;
Neurofibromatosis 1
;
Neurofibromatosis 2
;
Optic Nerve Glioma
;
Orbit
;
Retrospective Studies
7.Sumoylation of histone deacetylase 1 regulates MyoD signaling during myogenesis
Hosouk JOUNG ; Sehee KWON ; Kyoung Hoon KIM ; Yun Gyeong LEE ; Sera SHIN ; Duk Hwa KWON ; Yeong Un LEE ; Taewon KOOK ; Nakwon CHOE ; Jeong Chul KIM ; Young Kook KIM ; Gwang Hyeon EOM ; Hyun KOOK
Experimental & Molecular Medicine 2018;50(1):e427-
Sumoylation, the conjugation of a small ubiquitin-like modifier (SUMO) protein to a target, has diverse cellular effects. However, the functional roles of the SUMO modification during myogenesis have not been fully elucidated. Here, we report that basal sumoylation of histone deacetylase 1 (HDAC1) enhances the deacetylation of MyoD in undifferentiated myoblasts, whereas further sumoylation of HDAC1 contributes to switching its binding partners from MyoD to Rb to induce myocyte differentiation. Differentiation in C2C12 skeletal myoblasts induced new immunoblot bands above HDAC1 that were gradually enhanced during differentiation. Using SUMO inhibitors and sumoylation assays, we showed that the upper band was caused by sumoylation of HDAC1 during differentiation. Basal deacetylase activity was not altered in the SUMO modification-resistant mutant HDAC1 K444/476R (HDAC1 2R). Either differentiation or transfection of SUMO1 increased HDAC1 activity that was attenuated in HDAC1 2R. Furthermore, HDAC1 2R failed to deacetylate MyoD. Binding of HDAC1 to MyoD was attenuated by K444/476R. Binding of HDAC1 to MyoD was gradually reduced after 2 days of differentiation. Transfection of SUMO1 induced dissociation of HDAC1 from MyoD but potentiated its binding to Rb. SUMO1 transfection further attenuated HDAC1-induced inhibition of muscle creatine kinase luciferase activity that was reversed in HDAC1 2R. HDAC1 2R failed to inhibit myogenesis and muscle gene expression. In conclusion, HDAC1 sumoylation plays a dual role in MyoD signaling: enhancement of HDAC1 deacetylation of MyoD in the basally sumoylated state of undifferentiated myoblasts and dissociation of HDAC1 from MyoD during myogenesis.
Creatine Kinase, MM Form
;
Gene Expression
;
Histone Deacetylase 1
;
Histone Deacetylases
;
Histones
;
Luciferases
;
Muscle Cells
;
Muscle Development
;
Myoblasts
;
Myoblasts, Skeletal
;
Sumoylation
;
Transfection
8.2-Chlorodeoxyadenosine for Children with Recurrent or Refractory Langerhans Cell Histiocytosis.
Hoi Kyung YOON ; Hoon KOOK ; So Youn KIM ; Ik Sun CHOI ; Seok Joo KIM ; Kyoung Ran SOHN ; Dong Kyun HAN ; Ha Young NOH ; Jin Soo CHOI ; Tai Ju HWANG
Korean Journal of Pediatric Hematology-Oncology 2003;10(2):236-243
PURPOSE: Langerhans cell histiocytosis (LCH) is a disorder characterized by the proliferation of activated Langerhans cells. Although current therapies are very effective at inducing remission, multiple recurrences and long-term sequelae are common for young patients. For this reason, more effective therapies based on the pathogenesis of LCH are needed. We investigated the use of 2-chlorodeoxyadenosine (2-CdA), a purine analogue with an antiproliferative effect on histiocytes and lymphocytes, in patients with recurrent or refractory LCH. METHODS: Four children with recurrent or refractory LCH received 2-CdA (5~7 mg/m2/day for 5 days, given as a 24-hr continuous infusion and repeated every 21~28 days for 5~7 courses). RESULTS: All four patients had multiorgan involvement, and were heavily pretreated. Of the two children with recurrent diseases, one had complete response and the other showed no active disease except for the remaining diabetes insipidus. Two infants who showed poor early response to previous combination chemotherapy also responded poorly: partial response in one, and progressive disease resulting in death in the other. Toxicity consisted mainly of myelosuppression, but significant infections did not occur. The peripheral neuropathy was not seen. CONCLUSION: 2-CdA, tolerable in children without significant side effects, might be effective for the treatment of recurrent LCH in children. However, the efficacy in infants with multi-system, refractory diseases needs further study. The feasibility of 2-CdA treatment as the first-line therapy for high-risk diseases, and the possibility of combination with other agents needs to be addressed in the future.
Child*
;
Cladribine*
;
Diabetes Insipidus
;
Drug Therapy, Combination
;
Histiocytes
;
Histiocytosis, Langerhans-Cell*
;
Humans
;
Infant
;
Langerhans Cells
;
Lymphocytes
;
Peripheral Nervous System Diseases
;
Recurrence
9.Effects of Amrinone on the Vascular Tension of the Isolated Rabbit Pulmonary Artery.
Sang Yoon CHO ; Jung Kook SUH ; Woo Jong SHIN ; Jong Hoon YEOM ; Mi Kyung OH ; Kyoung Hun KIM ; Hee Koo YOO
Korean Journal of Anesthesiology 1999;37(4):694-703
BACKGROUND: Amrinone is a noncatecholamine, nonglycoside compound, which is known to possess both cardiac inotropic and vasodilatory actions. This drugs has been increasingly used in clinical practice for the management of low cardiac output syndrome during anesthesia, particularly for patients associated with right heart failure and pulmonary hypertension. The aim of this study was to explore the direct vasoactive effect of amrinone and its action mechanisms in the isolated rabbit pulmonary artery. METHODS: The rabbits' pulmonary arteries were dissected free and cut into rings (3 4 mm) and mounted for isometric tension in a tissue chamber. The effects of amrinone (5 10 6 5 10 4 M) on the vascular tension were assessed in the by KCl (40 mM)- or norepinephrine (NE, 10 6 M)- precontracted pulmonary arterial rings with or without endothelium. Also effects of K channel blockers (tetraethyl ammonium 20 mM, glybenclamide 2.5 10 5 M, 4-aminopyridine (4-AP) 5 10 4 M), protein kinase A & G inhibitor (H8), L-NAME, methylene blue and indomethacin on the amrinone- induced vascular responses were investigated. Also studied was effects of amrinone on the Ca2 influx through voltage operated channel (VOC) and receptor operated channel (ROC) of the vascular cells. RESULTS: Amrinone produced vasorelaxation of KCl- or NE-precontracted pulmonary artery in a dose-dependent fashion. The amrinone-induced vasorelaxation was not affected by the denudation of the endothelium. Pretreatment with L-NAME and methylene blue did not affect the vasodilatory effect of amrinone, suggesting that nitric oxide is not involved. Following pretreatment with indomethacin (a cyclooxygenase inhibitor) or K channel blockers, the amrinone-induced vasorelaxation was not altered. After exposure to Ca2 free solution, amrinone attenuated the KCl- or NE-induced contraction even in the presence of Ca2 , implying that VOC and ROC are blocked by amrinone. On the other hand, protein kinase A blocker (H8) completely abolished the amrinone-induced relaxation in the KCl-precontracted pulmonary artery. CONCLUSIONS: These findings suggest that the amrinone-induced vasorelaxations result from inhibition of VOC and ROC as well as from the activation of protein kinase A in the isolated rabbit pulmonary artery.
4-Aminopyridine
;
Ammonium Compounds
;
Amrinone*
;
Anesthesia
;
Cardiac Output, Low
;
Cyclic AMP-Dependent Protein Kinases
;
Endothelium
;
Glyburide
;
Hand
;
Heart Failure
;
Humans
;
Hypertension, Pulmonary
;
Indomethacin
;
Methylene Blue
;
NG-Nitroarginine Methyl Ester
;
Nitric Oxide
;
Norepinephrine
;
Prostaglandin-Endoperoxide Synthases
;
Pulmonary Artery*
;
Relaxation
;
Vasodilation
10.Effect of Mefloquine, a Gap Junction Blocker, on Circadian Period2 Gene Oscillation in the Mouse Suprachiasmatic Nucleus Ex Vivo.
Jinmi KOO ; Han Kyoung CHOE ; Hee Dae KIM ; Sung Kook CHUN ; Gi Hoon SON ; Kyungjin KIM
Endocrinology and Metabolism 2015;30(3):361-370
BACKGROUND: In mammals, the master circadian pacemaker is localized in an area of the ventral hypothalamus known as the suprachiasmatic nucleus (SCN). Previous studies have shown that pacemaker neurons in the SCN are highly coupled to one another, and this coupling is crucial for intrinsic self-sustainability of the SCN central clock, which is distinguished from peripheral oscillators. One plausible mechanism underlying the intercellular communication may involve direct electrical connections mediated by gap junctions. METHODS: We examined the effect of mefloquine, a neuronal gap junction blocker, on circadian Period 2 (Per2) gene oscillation in SCN slice cultures prepared from Per2::luciferase (PER2::LUC) knock-in mice using a real-time bioluminescence measurement system. RESULTS: Administration of mefloquine causes instability in the pulse period and a slight reduction of amplitude in cyclic PER2::LUC expression. Blockade of gap junctions uncouples PER2::LUC-expressing cells, in terms of phase transition, which weakens synchrony among individual cellular rhythms. CONCLUSION: These findings suggest that neuronal gap junctions play an important role in synchronizing the central pacemaker neurons and contribute to the distinct self-sustainability of the SCN master clock.
Animals
;
Circadian Rhythm
;
Electrical Synapses
;
Gap Junctions*
;
Hypothalamus
;
Luminescent Measurements
;
Mammals
;
Mefloquine*
;
Mice*
;
Neurons
;
Phase Transition
;
Suprachiasmatic Nucleus*