1.Comparison of physical properties of the various 3D printing temporary crown and bridge resin
Seo Jin PARK ; Han Ah LEE ; Sang Hyeok LEE ; Soohwang SEOK ; Bum Soon LIM ; Jae Sung KWON ; Kwang Mahn KIM
Korean Journal of Dental Materials 2019;46(3):139-152
Conventional dental resins for crown and bridge fulfill ISO 10477 and ISO 10993 before clinical application. Although 3D printing or rapid prototyping (RP) for the fabrication of temporary crown and bridge have been proposed, a little studies were reported for 3D printing resin for temporary crown and bridge. The purpose of this study was to evaluate the physical properties (such as water sorption and solubility, color stability and flexural strength) of the various 3D printing temporary crown and bridge resin following the ISO 10477:2018 and estimate the effect of chemical composition of resin on the physical properties. Four resins approved by KFDA and 4 experimental resins developed by different manufacturer were tested in this study. Samples were prepared with DLP typed 3D Printer (G-Printer) and post-cured using UV-light Cure Unit (Cure M). Proper 3D printing and post-curing conditions were selected for different 3D printing resins. Each test was performed according to the ISO 10477 and results were statistically analyzed using Tukey-multiple comparison test (p=0.05). Only group-B did not satisfied the ISO requirement (< 40 µg/ mm³) in water sorption test, but 3 groups (C, E and F) showed high solubility which exceeds the ISO requirement (< 7.5 µg/mm³). For color stability, the color difference were detected at 5 groups (A, E, F, G and H). Group-D and F showed the low flexural strength and some building direction did not satisfied the ISO requirement (> 60 MPa). Resin components may affect the flexural strength, then user should check the components of 3D printing resin. Deficient degree of polymerization may lead to large water sorption, water solubility and color changes. Further study should be done comparison between specimens printed with specific 3D printer recommended by manufacturer and specimens used in this study.
Crowns
;
Polymerization
;
Polymers
;
Printing, Three-Dimensional
;
Resins, Synthetic
;
Solubility
;
Water
2.Lineage-specific Expression of miR-200 Family in Human Embryonic Stem Cells during In Vitro Differentiation.
Yeji KIM ; Nury KIM ; Sang Wook PARK ; Hyemin KIM ; Han Jin PARK ; Yong Mahn HAN
International Journal of Stem Cells 2017;10(1):28-37
Although microRNAs have emerged as key regulators in diverse cellular processes, the roles of microRNAs are poorly understood in human embryonic stem cells (hESCs) during differentiation into specialized cell types. In this study, we used a microRNA array with 799 human microRNA probes to examine the expression profiles of microRNAs in hESCs during differentiation into endodermal and mesodermal lineages in vitro. Among the microRNAs analyzed, 7 and 20 microRNAs were enriched in the developmental process of hESCs into mesodermal and endodermal lineages, respectively. In particular, the expression levels of miR-200 family, which is known to regulate the epithelial to mesenchymal transition (EMT), gradually increased in hESCs during differentiation into hepatocytes while they gradually decreased during differentiation into vascular endothelial cells. Downregulation of ZEB1, a direct target of miR-200 family, and E-CADHERIN, a target protein of ZEB1, was observed in hESCs during differentiation into endodermal and mesodermal lineages, respectively. These results indicate that miR-200 family has an important role in determining the cell fate between endodermal and mesodermal lineages from the pluripotent state.
Cadherins
;
Down-Regulation
;
Endoderm
;
Endothelial Cells
;
Hepatocytes
;
Human Embryonic Stem Cells*
;
Humans
;
Humans*
;
In Vitro Techniques*
;
Mesoderm
;
MicroRNAs
3.Association between the Red Cell Distribution Width and Vasospastic Angina in Korean Patients.
Mi Hyang JUNG ; Dong Il SHIN ; Ik Jun CHOI ; Suk Min SEO ; Sooa CHOI ; Mahn Won PARK ; Pum Joon KIM ; Sang Hong BAEK ; Ki Bae SEUNG
Yonsei Medical Journal 2016;57(3):614-620
PURPOSE: The association between the red cell distribution width (RDW) and vasospastic angina (VSA) has not been elucidated. We investigated the association of the RDW with the incidence and angiographic subtypes of VSA in Korean patients. MATERIALS AND METHODS: A total of 460 patients who underwent intracoronary ergonovine provocation tests were consecutively enrolled and classified into two groups: the VSA group (n=147, 32.0%) and non-VSA group (n=313, 68.0%). The subjects were classified into 3 subgroups (tertiles) according to the baseline level of RDW assessed before the angiographic provocation test. RESULTS: The VSA group had a higher RDW than the non-VSA group (12.9±0.8% vs. 12.5±0.7%, p=0.013). The high RDW level demonstrated an independent association with the high incidence of VSA [second tertile: hazard ratio (HR) 1.96 (1.13-2.83), third tertile: HR 2.33 (1.22-3.47), all p<0.001]. Moreover, the highest RDW tertile level had a significant association with the prevalence of the mixed-type coronary spasm [HR 1.29 (1.03-1.59), p=0.037]. CONCLUSION: The high level of RDW was significantly associated with the prevalence of VSA and the high-risk angiographic subtype of coronary spasm, suggesting that a proactive clinical investigation for VSA could be valuable in Korean patients with an elevated RDW.
Aged
;
Aged, 80 and over
;
Angina Pectoris/*blood/ethnology
;
Coronary Angiography/methods
;
Coronary Vasospasm/*blood/ethnology
;
Erythrocyte Indices/*physiology
;
Female
;
Humans
;
Incidence
;
Male
;
Middle Aged
;
Prevalence
;
Proportional Hazards Models
;
Republic of Korea/epidemiology
4.A Case of Fish Bone-Induced Submandibular Gland Stone.
Dong Hyun LEE ; Sang Min KIM ; Jae Mahn CHO ; Mi Ra KIM
Korean Journal of Otolaryngology - Head and Neck Surgery 2016;59(2):162-164
Sialolithiasis is the most common disorder associatd with major salivary glands. It may form in any salivary glands or ducts, but is reported to occur more often in the submandibular gland than in the parotid or sublingual gland. Although the pathogenesis is not perfectly revealed, there appear to be several factors that predispose the submandibular gland duct to be a common site of sialolithiasis. Sialolithiasis occurs as a consequence of the precipitation of calcium salts around a central nidus of desquamated epithelial cells, inflammatory cells, mucoid gels or foreign body. However, it is not a common thing that foreign body entered into the salivary duct through duct orifice may act as the initiating factor. We have recently experienced a case in a 52-year-old female, in which sialolithiasis seems to have formed due to a a foreign body, a fish bone, in the right submandibular gland duct.
Calcium
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Epithelial Cells
;
Female
;
Foreign Bodies
;
Gels
;
Humans
;
Middle Aged
;
Salivary Ducts
;
Salivary Gland Calculi
;
Salivary Glands
;
Salts
;
Sublingual Gland
;
Submandibular Gland*
5.Transcriptional Profiles of Imprinted Genes in Human Embryonic Stem Cells During In vitro Differentiation.
Sang Wook PARK ; Hyo Sang DO ; Dongkyu KIM ; Ji Yun KO ; Sang Hun LEE ; Yong Mahn HAN
International Journal of Stem Cells 2014;7(2):108-117
BACKGROUND AND OBJECTIVES: Genomic imprinting is an inheritance phenomenon by which a subset of genes are expressed from one allele of two homologous chromosomes in a parent of origin-specific manner. Even though fine-tuned regulation of genomic imprinting process is essential for normal development, no other means are available to study genomic imprinting in human during embryonic development. In relation with this bottleneck, differentiation of human embryonic stem cells (hESCs) into specialized lineages may be considered as an alternative to mimic human development. METHODS AND RESULTS: In this study, hESCs were differentiated into three lineage cell types to analyze temporal and spatial expression of imprinted genes. Of 19 imprinted genes examined, 15 imprinted genes showed similar transcriptional level among two hESC lines and two human induced pluripotent stem cell (hiPSC) lines. Expressional patterns of most imprinted genes were varied in progenitors and fully differentiated cells which were derived from hESCs. Also, no consistence was observed in the expression pattern of imprinted genes within an imprinting domain during in vitro differentiation of hESCs into three lineage cell types. CONCLUSIONS: Transcriptional expression of imprinted genes is regulated in a cell type-specific manner in hESCs during in vitro differentiation.
Alleles
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Embryonic Development
;
Embryonic Stem Cells*
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Female
;
Genomic Imprinting
;
Human Development
;
Humans
;
Parents
;
Pluripotent Stem Cells
;
Pregnancy
;
Wills
6.A Case of Three Consecutive Events of Acute Myocardial Infarctions in Three Different Vessels.
Hyun YANG ; Sung Ho HER ; Mahn Won PARK ; Jung Sun CHO ; Chan Joon KIM ; Jong Bum KWON ; Sang Mi RO ; Yun Kyung PARK
Korean Circulation Journal 2013;43(10):694-698
A 51-year-old man was being admitted to the emergency department with chest pains. He had a history of acute myocardial infarction (MI) on two prior occasions and was successfully treated with drug eluting stents. He was diagnosed with 3 consecutive events of acute MI in 3 different vessels. The consecutive events of acute MI in different vessels are a very rare case. He did not have risk factors, such as coagulation abnormality, clopidogrel resistance, patient's compliance and vessel abnormality, except for his cigarette smoking. We reported the first case with 3 consecutive events of acute MI in each 3 vessels during a long-term interval.
Chest Pain
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Coronary Vessels
;
Drug-Eluting Stents
;
Emergencies
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Humans
;
Middle Aged
;
Myocardial Infarction*
;
Risk Factors
;
Smoking
;
Thrombosis
7.A patient with Churg-Strauss syndrome who underwent endoscopic sinus surgery under general anesthesia: A case report.
Hyo Sang IM ; Kwang Rae CHO ; Chee Mahn SHIN ; Young Jae KIM ; Young Kyun CHOE ; Soon Ho CHEONG ; Kun Moo LEE ; Jeong Han LEE ; Se Hun LIM ; Young Hwan KIM ; Sang Eun LEE
Korean Journal of Anesthesiology 2010;59(1):49-52
There are many cause of cholinesterase deficiency, including drugs, liver disease, chronic anemia, malignant states, cardiac failure, severe acute infection, surgical shock, severe burn, collagen disease and vasculitis syndromes. Vasculitis syndromes are relatively rare, and among them, Churg-Strauss syndrome (CSS) is even rarer. We report here on a case of a patient with CSS who underwent endoscopic sinus surgery under general anesthesia.
Anemia
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Anesthesia, General
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Burns
;
Cholinesterases
;
Churg-Strauss Syndrome
;
Collagen Diseases
;
Heart Failure
;
Humans
;
Liver Diseases
;
Shock, Surgical
;
Vasculitis
8.Lambert-Eaton myasthenic syndrome as a cause of persistent neuromuscular weakness after a mediastinoscopic biopsy: A case report.
Cheol Jin LEE ; Se Hun LIM ; Chee Mahn SHIN ; Young Jae KIM ; Young Kyun CHOE ; Soon Ho CHEONG ; Kun Moo LEE ; Jeong Han LEE ; Young Hwan KIM ; Kwang Rae CHO ; Sang Eun LEE ; Jong Suk BAE
Korean Journal of Anesthesiology 2010;59(1):45-48
There are many causes of prolonged postoperative muscle weakness, including drugs, residual anesthetics, cerebrovascular events, electrolyte imbalance, hypothermia, and neuromuscular disease. Neuromuscular diseases are relatively rare, with the most common being myasthenia gravis and Lambert-Eaton myasthenic syndrome (LEMS). We report an unusual case in which a patient who was given a muscle relaxant during mediastinoscopy developed postoperative muscle weakness that was ultimately diagnosed as secondary to LEMS.
Anesthetics
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Humans
;
Hypothermia
;
Lambert-Eaton Myasthenic Syndrome
;
Mediastinoscopy
;
Muscle Weakness
;
Muscles
;
Myasthenia Gravis
;
Neuromuscular Diseases
9.Inter-arm arterial pressure difference caused by prone position in the thoracic outlet syndrome patient: A case report.
Seung Su KIM ; Soon Ho CHEONG ; Won Jin LEE ; Dong Hwa JUN ; Myoung Jin KO ; Kwang Rae CHO ; Sang Eun LEE ; Young Hwan KIM ; Se Hun LIM ; Jeong Han LEE ; Kun Moo LEE ; Young Kyun CHOE ; Young Jae KIM ; Chee Mahn SHIN
Korean Journal of Anesthesiology 2010;58(1):91-94
Thoracic outlet syndrome has neurologic symptoms caused by compression of brachial plexus, blood vessel symptoms are caused by compression of the artery or vein. The authors report a case of sudden decrease in blood pressure of the left arm after turning the patient from supine position to prone position. They confirmed that the patient had thoracic outlet syndrome after performing computed tomography.
Arm
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Arterial Pressure
;
Arteries
;
Blood Pressure
;
Blood Vessels
;
Brachial Plexus
;
Glycosaminoglycans
;
Humans
;
Neurologic Manifestations
;
Prone Position
;
Supine Position
;
Thoracic Outlet Syndrome
;
Veins
10.The effect of propofol on emergence agitation in children receiving sevoflurane for adenotonsillectomy.
Cheol Jin LEE ; Sang Eun LEE ; Min Kyung OH ; Chee Mahn SHIN ; Young Jae KIM ; Young Kyun CHOE ; Soon Ho CHEONG ; Kun Moo LEE ; Jeong Han LEE ; Se Hun LIM ; Young Hwan KIM ; Kwang Rae CHO
Korean Journal of Anesthesiology 2010;59(2):75-81
BACKGROUND: The administration of a single dose of propofol is reported to be effective in decreasing the incidence and severity of emergence agitation (EA) in children following sevoflurane anesthesia. The aim of this study was to investigate the clinical usefulness of a single dose of propofol 1 mg/kg at the end of adenotonsillectomy for reducing the incidence of EA after sevoflurane anesthesia. METHODS: Ninety children, aged 3-8 years, undergoing adenotonsillectomy were randomized into two groups: the propofol group (n = 45) and the saline group (n = 45), of which 88 children completed the study. Anesthesia was maintained with sevoflurane 2-2.5 vol% and nitrous oxide/oxygen (50%/50%). At the completion of adenotonsillectomy, the propofol group patients were given 1 mg/kg of propofol and the saline group patients were given saline 0.1 ml/kg in the same volume. The incidence of EA was assessed with Aono's four point scale and the severity of EA was assessed with pediatric anesthesia emergence delirium (PAED) scale at 5 min (T5), 15 min (T15) and 30 min (T30) after emergence. RESULTS: Of the 88 patients, the incidence of EA at T5, T15 and T30 was 61.4%, 27.3%, and 4.5% in the propofol group while in the saline group was 68.2%, 29.5%, and 9.1%, respectively. The incidence and severity of EA were not found to be significantly different between the two groups, but the scales in each group decreased significantly over time. CONCLUSIONS: The administration of propofol 1 mg/kg at the end of surgery did not have any significant effect in reducing the incidence and severity of EA in children undergoing adenotonsillectomy under sevoflurane anesthesia.
Aged
;
Anesthesia
;
Child
;
Delirium
;
Dihydroergotamine
;
Humans
;
Incidence
;
Methyl Ethers
;
Propofol
;
Weights and Measures

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