1.In vitro Differentiation of Human Embryonic Stem Cells into Definitive Endodermal Cells.
Misun LIM ; Dongho CHOI ; Sook Ja KIM ; Hee Jeong CHEONG ; Jong Ho WON
The Journal of the Korean Society for Transplantation 2007;21(2):216-222
PURPOSE: Whole liver transplantation has limitation including donor shortage and fatal surgical complications. Hepatocyte transplantation, which is simpler and less expensive than whole liver transplantation, allows the use of living related donors, permits the use of a single donor organ for multiple recipients. However, hepatocytes have limitation in proliferation and lose their property during culture period. To over come these problems, here we performed differentiation of human embryonic stem cells (hESCs) into definitive endoderm in order to differentiate into hepatocytes efficiently. METHODS: Undifferentiated hESCs were maintained on mouse embryo fibroblast feeder (MEF) layer for 5~7 days. For endoderm differentiation, we used modified Kevin A D'Amour's method that added 100 ng/mL Activin A for 5 days. After differentiation, differentiated endodermal cells were collected and RT-PCR and immunostain analysis were performed. RESULTS: After 5 days of differentiation period, hES cells showed endoderm committed-cells and increased expression of endoderm-specific marker genes (Sox17 and Foxa2). Also differentiated endoderm cells were stained with Sox17 and Foxa2 whereas undifferentiated hES cells were not stained with Sox17, Foxa2. CONCLUSION: In vitro differentiotion from hES cells to definitive endoderm was done repetitively by our methods. Further well defined protocol for differentiation of definitive endoderm to hepatocytes should be made.
Activins
;
Animals
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Embryonic Stem Cells*
;
Embryonic Structures
;
Endoderm*
;
Fibroblasts
;
Hepatocytes
;
Humans*
;
Liver Transplantation
;
Mice
;
Tissue Donors
2.Rapidly Progressive Small Bowel Necrosis in a Previously Healthy Child without Proven Mechanical Obstruction
Hyun Hee KIM ; Hyungoo KANG ; Chul Hee PARK ; Yu Jin KWON ; Euna JUNG ; Misun LIM
Pediatric Gastroenterology, Hepatology & Nutrition 2019;22(3):291-297
Bowel ischemia is a life-threatening surgical emergency. We report a case of rapidly progressive bowel necrosis in a previously healthy child without proven mechanical small bowel obstruction. The definite diagnosis was established at the time of an exploratory operation. Of note, imaging studies and even a laparotomy did not reveal any evidence of acute appendicitis or mechanical obstruction such as intussusception or Meckel's diverticulum. During hospitalization, since we could not rule out surgical abdomen after inconclusive image findings, we closely followed the patient and repeated physical examinations carefully. Eventually surgical exploration was performed based on changes in clinical condition, which proved to be the right decision for the patient. We propose that in children with suspected strangulation of small bowel obstruction, especially when imaging findings do not provide a conclusive diagnosis, the timely exploratory surgical approach ought to be chosen based on carefully observed clinical findings and other evaluations.
Abdomen
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Appendicitis
;
Child
;
Diagnosis
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Emergencies
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Hospitalization
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Humans
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Intestine, Small
;
Intussusception
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Ischemia
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Laparotomy
;
Meckel Diverticulum
;
Mesenteric Ischemia
;
Necrosis
;
Physical Examination
3.Treatment of Facial Arteriovenous Malformations by Embolization: A Case Report
Jeongyeon KIM ; Hyunsoo LIM ; Okhyung NAM ; Hyo-seol LEE ; Sungchul CHOI ; Misun KIM
Journal of Korean Academy of Pediatric Dentistry 2022;49(2):228-233
Arteriovenous malformations (AVMs) are rare congenital anomalies characterized by direct communication between arteries and veins that bypass the capillary bed. AVMs may not manifest clinically until late infancy or childhood. In particular, facial AVMs can cause urgent life-threatening dental events. A 5-year-old girl without a medical history visited the hospital because of spontaneous gingival bleeding around the posterior gingival area of the lower left 2nd primary molar.
Angiography through the femoral approach under general anesthesia was performed for differential diagnosis and therapeutic option. The blood flow was effectively reduced after arterial embolization alone, and there was no evidence of recurrence at the 5-month follow-up.
The present study reports that embolization of the affected vessels can be a more effective and safe method than surgical resection for the treatment of AVM during the growth period.
4.Performance Evaluation of the ARCHITECT i2000 for the Determination of Whole Blood Cyclosporin A and Tacrolimus
Journal of Laboratory Medicine and Quality Assurance 2019;41(2):117-119
Maintaining immunosuppressant concentrations within the therapeutic range in organ recipients requires regular monitoring. The blood concentrations of immunosuppressants are routinely measured using one of several automated immunoassays, such as chemiluminescence immunoassays (CLIAs) and liquid chromatography-tandem mass spectrometry (LC-TMS). The ARCHITECT i2000 immunoassay analyzer (Abbott Diagnostics, USA) was developed as an automated CLIA analyzer for the measurement of cyclosporin A and tacrolimus in whole blood. Here, the precision and linearity of the ARCHITECT i2000 analyzer for the detection of cyclosporin A and tacrolimus in whole blood were evaluated according to Clinical and Laboratory Standards Institute guidelines and were compared with those of an LC-TMS detection method. The total coefficient of variation for the two drugs was less than 10%, and they showed linearity values of 0.97 or more, which was within the manufacturer's range. The measurements of both immunosuppressants by the ARCHITECT i2000 were closely correlated with measurements determined by LC-TMS. However, most measurements were lower with LC-TMS than with the ARCHITECT i2000. Measurement of cyclosporin A and tacrolimus in whole blood using the ARCHITECT i2000 showed very satisfactory performance in terms of precision and linearity as well as good correlation with the comparative method.
Cyclosporine
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Immunoassay
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Immunosuppressive Agents
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Luminescence
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Mass Spectrometry
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Methods
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Tacrolimus
5.In vitro Differentiation of Human Mesenchymal Stem Cells into Hepatocytes.
Misun LIM ; Dongho CHOI ; Jung Hoon KIM ; Jin Seok JEON ; Yun Seob SONG ; Sook Ja KIM ; Hee Jeong CHEONG ; Jong Ho WON
The Journal of the Korean Society for Transplantation 2006;20(1):35-40
PURPOSE: Whole liver transplantation has limitation including donor shortage and fatal surgical complications. Hepatocyte transplantation, which is simpler and less expensive than whole liver transplantation, allows the use of living related donors, permits the use of a single donor organ for multiple recipients, and makes possible the cryopreser-vation of hepatocytes for future use. However, hepatocytes have limitation of proliferation and lose their property during culture period. To over come this problems, here we performed differentiation of bone marrow derived mesenchymal stem cells into hepatocytes. METHODS: Human bone marrow cells were harvested from posterior iliac spine of male and then mononuclear cells were obtained by Ficoll-Paque density-gradient centrifuge and plated in tissue culture flasks. For hepatogenic differentiation, we used modified Kuan-Der Lee's method. After differentiation, hepatocytes were collected and RT-PCR and PAS stain analysis were performed. RESULTS: After 5 weeks of cultivation period, mesenchymal stem cells showed cuboidal morphology and contained abundant granules in the cytoplasm. RT-PCR analysis showed increased expression of hepatocyte-specific marker genes (albumin,CK18, PERCK, CPS). Undifferentiated MSCs were not stained with PAS and differentiated hepatocytes from human MSCs stained with PAS indicating that hepatocytes contained glycogen in the cytoplasm. CONCLUSION: Hepatocyte transplantation could be one of the most effective treatments for chronic liver disease. However, hepatocyte has several disadvantages and problems. For alternative cell therapy sources, human bone marrow derived MSCs are considered as transplantable cells. Human MSCs are able to differentiate into functional hepatocytes in vitro and can be a possible cell transplantation source for chronic liver disease patients. Further studies should be done for differentiating human MSCs to hepatocytes in vivo condition.
Bone Marrow
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Bone Marrow Cells
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Cell Transplantation
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Cell- and Tissue-Based Therapy
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Cytoplasm
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Glycogen
;
Hepatocytes*
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Humans*
;
Liver Diseases
;
Liver Transplantation
;
Male
;
Mesenchymal Stromal Cells*
;
Spine
;
Tissue Donors
;
Transplants
6.Quinolone-resistant Shigella flexneri Isolated in a Patient Who Travelled to India.
You La JEON ; You Sun NAM ; Gayoung LIM ; Sun Young CHO ; Yun Tae KIM ; Ji Hyun JANG ; Junyoung KIM ; Misun PARK ; Hee Joo LEE
Annals of Laboratory Medicine 2012;32(5):366-369
We report a recent case in which ciprofloxacin-resistant Shigella flexneri was isolated from a 23-yr-old female patient with a history of travel to India. Prior to her admission to our internal medicine department, she experienced symptoms of high fever and generalized weakness from continuous watery diarrhea that developed midway during the trip. S. flexneri was isolated from the stool culture. Despite initial treatment with ciprofloxacin, the stool cultures continued to show S. flexneri growth. In the susceptibility test for antibiotics of the quinolone family, the isolate showed resistance to ciprofloxacin (minimum inhibitory concentration [MIC], 8 microg/mL), norfloxacin (MIC, 32 microg/mL), ofloxacin (MIC, 8 microg/mL), nalidixic acid (MIC, 256 microg/mL), and intermediate resistance to levofloxacin (MIC, 4 microg/mL). In molecular studies for quinolone resistance related genes, plasmid borne-quinolone resistance genes such as qnrA, qnrB, qnrS, aac(6')-Ib-cr, qepA, and oqxAB were not detected. Two mutations were observed in gyrA (248C-->T, 259G-->A) and 1 mutation in parC (239G-->T). The molecular characteristics of the isolated S. flexneri showed that the isolate was more similar to the strains isolated from the dysentery outbreak in India than those isolated from Korea.
Anti-Bacterial Agents/pharmacology
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Bacterial Proteins/genetics/metabolism
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Drug Resistance, Bacterial/drug effects
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Dysentery, Bacillary/microbiology
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Feces/microbiology
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Female
;
Humans
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India
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Mutation
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Quinolones/*pharmacology
;
Shigella flexneri/drug effects/*isolation & purification/metabolism
;
Travel
;
Young Adult