Chondrogenic Differentiation of Mesenchymal Stem Cells from Human Umbilical Cord Blood / 대한정형외과학회잡지

PURPOSE: The aim of this study was to demonstrate the existence of circulating mesenchymal stem cells (MSC) in the human umbilical cord blood (hUCB) and to evaluate the chondrogenic differentiation potential of hUCB-derived MSC in vitro. MATERIALS AND METHODS: Fifty hUCB harvests were cultured in media supplemented with 10% fetal bovine serum. The adherent fibroblast-like cells were characterized by immunophenotyping and induced to differentiate into chondrocytes in the pellet culture with and without BMP-6. This study performed RTPCR of the chondrogenic markers, Safranin-O stain and type II collagen immunohistochemical stain. RESULTS: The mononuclear cells isolated from hUCB formed adherent colonies with an attached wellspread fibroblast-like morphology. The cells positively expressed the MSC-related antigens, but did not express the hematopoietic, HLA-DR, endothelial, or osteoclast antigens and could be induced to differentiate into chondrocytes under proper stimulation. BMP-6 increased the size of the pellet and the mRNA levels for aggrecan, type II collagen and type IX collagen and enhanced the levels of proteoglycan synthesis during chondrogenic differentiation. CONCLUSION: The homogenous fibroblast-like cells developed in cultures from hUCB with chondrogenic differentiation potential were considered to be MSC. Furthermore, it was found that BMP-6 enhanced chondrogenic differentiation of the hUCB-derived MSC in the pellet culture.

Osteogenic Differentiation of Mesenchymal Stem/Progenitor Cells Developed in Cultures from Human Umbilical Cord Blood / 대한정형외과연구학회지

PURPOSE: To demonstrate the existence in human umbilical cord blood (hUCB) of circulating mesenchymal stem/progenitor cells(MSPC), the adherent cells developed in cultures from hUCB were characterized and induced to differentiate into osteoblasts. MATERIALS AND METHODS: Fifty hUCB harvests were cultured in the media supplemented with 10% fetal bovine serum. Homogeneously adherent fibroblast-like cells obtained during successive subcultivation were characterized by immunophenotyping analysis and induced to differentiate into osteoblasts. Reverse transcription-polymerase chain reaction of osteogenic markers, alkaline phosphatase (ALP) stain, and von Kossa stain were performed. RESULTS: The adherent fibroblast-like cells developed in cultures from hUCB positively expressed the MSPCrelated antigens, but, did not express the hematopoietic, HLA-DR, osteoclast, or endothelial antigens. These cells were well proliferated during successive subcultivation. Under osteogenic condition, these cells showed increased levels of osteogenic mRNAs and strong positivity in ALP and von Kossa stains at 4th week. CONCLUSION: The homogeneous fibroblast-like cells developed in cultures from hUCB were considered to be MSPC. Morphological and immunophenotypical characteristics of these cells were very similar to those of bone marrow-derived MSPC, and well differentiated into osteoblasts.

Performance Evaluation of TOSOH Automated Glycohemoglobin Analyzer HLC-723GHb V A1c 2.2TM / 대한임상병리학회지

BACKGROUND: We evaluated the performance of the TOSOH glycohemoglobin analyzer HLC-723GHb V A1c 2.2TM (TOSOH Corp. Kyoto, Japan), a recently introduced automated hemoglobin A1c (HbA1c) analyzer using high performance liquid chromatography (HPLC) method without sample pretreatment. METHODS: The performance characteristics evaluated were precision, linearity, comparison with VARIANTTM (Bio-Rad, Germany) and throughput following NCCLS evaluation protocols (EP5-T2, EP6-P, and EP9-T). RESULTS: The within-run and between-day CV's were 0.910 and 1.328 for low level (6.2%), 1.214 and 1.460 for middle level (8.5%), and 0.789 and 1.449 for high level (10.7%), respectively. We found the perfect linearity of HbA1c (%) from 6.5 to 10.2 (r2=0.9995). Comparison studies between A1c 2.2 and VARIANTTM yielded the following correlation equations; A1c 2.2TM = 0.9915 (VARIANTTM) + 0.1198 %HbA1c (r=0.9936, P < 0.0001). Throughput was 28.0 tests per hour for A1c 2.2TM compared with 15.2 tests for VARIANTTM, which were determined including red blood cell lysis time before sample loading for VARIANTTM. A1c 2.2TM did not need sample pretreatment. CONCLUSIONS: With the above results, A1c 2.2TM shows acceptable performance and is suitable for routine use in the clinical laboratory.