No abstract available.
Fetal Blood* ; Stem Cells*

No abstract available.
Fetal Blood* ; Humans* ; Stem Cells* ; Umbilical Cord*

Stem cell therapy using mesenchymal stem cells(MSCs) transplantation have been paid attention because of their powerful proliferation and pluripotent differentiating ability. Although umbilical cord blood (UCB) is well known to be a rich source of hematopoietic stem cells with practical and ethical advantages, the presence of mesenchymal stem cells (MSCs) in UCB has been controversial and it remains to be validated. In this study, we examine the presence of MSCs in UCB harvests and the prevalence of them is compared to that of endothelial progenitor cells. For this, CD34+ and CD34- cells were isolated and cultured under the endothelial cell growth medium and mesenchymal stem cell growth medium respectively. The present study showed that ESC-like cells could be isolated and expanded from preterm UCBs but were not acquired efficiently from full-terms. They expressed CD14-, CD34-, CD45-, CD29+, CD44+, CD105+ cell surface marker and could differentiate into adipogenic and osteogenic lineages. Our results suggest that MSCs are fewer in full-term UCB compared to endothelial progenitor cells.
Endothelial Cells ; Fetal Blood* ; Hematopoietic Stem Cells ; Humans* ; Mesenchymal Stromal Cells* ; Prevalence ; Stem Cells* ; Umbilical Cord

PURPOSE: Many studies for hematopoietic stem cell have investigated CD133, instead of CD34, as a new surrogate stem cell marker. Counterflow centrifugal elutriation (CCE) is a physical separation of a homogeneous cell population through cell sedimentation characteristics. We evaluated the stem cell distribution and hematopoietic function from cord blood (CB) and bone marrow (BM) through CCE. METHODS: We obtained total nucleated cells from CB and BM, and separated the cell fractions according to media infusion flow rates (17 mL/min (FR 17), 24 mL/min (FR 24), 29 mL/min (FR 29), and rotor off (R/O) ) by CCE. We analyzed the proportion of CD34+ and CD133+ cells in each fraction, and performed methylcellulose-based colony assay. RESULTS: In CB, the cell recovery rates after CCE were 5.9+/-4.3% in FR 17, 4.2+/-2.1% in FR 24, 19.4+/-11.9% in FR 29, and 61.9+/-11.7% in R/O. In BM, they were 14.9+/-8.2% in FR 17, 17.4+/-13.4% in FR 24, 23.6+/-6.11% in FR 29, and 27.1+/-8.9% in R/O. The distributions of CD133+ and CD34+ cells in CB were more abundant in R/O (2.91%, 1.85%) than in other fractions. In BM, CD133+ and CD34+ cell rates in R/O (5.40%, 2.75%) were similar with those in unmanipulated BM (5.48%, 2.78%). In both CB and BM, there was more CFU-GM and BFU-E in R/O than in other fractions. CONCLUSION: We suggested that the distribution of CD34+ and CD133+ cells might be different between CB and BM. However, the R/O containing relatively large cells could have an effective clonogenicity compared with the unmanipulated sample in both CB and BM.
Bone Marrow* ; Erythroid Precursor Cells ; Fetal Blood* ; Granulocyte-Macrophage Progenitor Cells ; Hematopoietic Stem Cells ; Stem Cells

BACKGROUND: CD34 positive cell enumeration by flow cytometry is currently used to determine the optimal timing of peripheral blood stem cell collections (PBSC) and to predict engraftment of stem cell transplantation. However, the technical problems and lack of a standardized method are sources of significant variability in the quantitation of the CD34 positive cells. ProCOUNT(TM) (Beckon Dickinson Immuno- cytometry System, USA) kit for three color flow cytometric analysis was introduced to enumerate CD34 positive cells using a standardized method. This study was conducted to evaluate the usefulness of the three color method, ProCOUNT(TM), in comparison with two color method. METHODS: CD34 positive cells from 25 cord blood samples were enumerated by two methods, two color (CD34-PE/CD45-FITC) and three color (ProCOUNT(TM) , nucleic acid dye/CD34-PE/ CD45-PerCP) flow cytometric analysis, in which CD34 positive cells were counted directly in comparison with counting beads introduced in the sample. RESULTS: The count of CD34 positive cells in the cord blood was 28.3(+/-20.0)/uL and 20.9 (+/-16.0) /uL by three color and two color methods, respectively, The number of CD34 positive cells enumerated by ProCOUNTTM kit was well correlated with that by two color method, but the count was significantly higher in the former method (p<0.01). CONCLUSIONS: In the three color method, loss of stem cells was significantly lower than that in the two color method, and it was possible to obtain a direct count of CD34 positive cells by using a standardized procedure.
Fetal Blood* ; Flow Cytometry ; Hematopoietic Stem Cells* ; Stem Cell Transplantation ; Stem Cells

BACKGROUND: CD34 positive cell enumeration by flow cytometry is currently used to determine the optimal timing of peripheral blood stem cell collections (PBSC) and to predict engraftment of stem cell transplantation. However, the technical problems and lack of a standardized method are sources of significant variability in the quantitation of the CD34 positive cells. ProCOUNT(TM) (Beckon Dickinson Immuno- cytometry System, USA) kit for three color flow cytometric analysis was introduced to enumerate CD34 positive cells using a standardized method. This study was conducted to evaluate the usefulness of the three color method, ProCOUNT(TM), in comparison with two color method. METHODS: CD34 positive cells from 25 cord blood samples were enumerated by two methods, two color (CD34-PE/CD45-FITC) and three color (ProCOUNT(TM) , nucleic acid dye/CD34-PE/ CD45-PerCP) flow cytometric analysis, in which CD34 positive cells were counted directly in comparison with counting beads introduced in the sample. RESULTS: The count of CD34 positive cells in the cord blood was 28.3(+/-20.0)/uL and 20.9 (+/-16.0) /uL by three color and two color methods, respectively, The number of CD34 positive cells enumerated by ProCOUNTTM kit was well correlated with that by two color method, but the count was significantly higher in the former method (p<0.01). CONCLUSIONS: In the three color method, loss of stem cells was significantly lower than that in the two color method, and it was possible to obtain a direct count of CD34 positive cells by using a standardized procedure.
Fetal Blood* ; Flow Cytometry ; Hematopoietic Stem Cells* ; Stem Cell Transplantation ; Stem Cells

To date, the use of red blood cells (RBCs) produced from stem cells in vitro has not proved practical for routine transfusion. However, the perpetual and widespread shortage of blood products, problems related to transfusion-transmitted infections, and new emerging pathogens elicit an increasing demand for artificial blood. Worldwide efforts to achieve the goal of RBC production through stem cell research have received vast attention; however, problems with large-scale production and cost effectiveness have yet to prove practical usefulness. Some progress has been made, though, as cord blood stem cells and embryonic stem cells have shown an ability to differentiate and proliferate, and induced pluripotent stem cells have been shown to be an unlimited source for RBC production. However, transfusion of stem cell-derived RBCs still presents a number of challenges to overcome. This paper will summarize an up to date account of research and advances in stem cell-derived RBCs, delineate our laboratory protocol in producing RBCs from cord blood, and introduce the technological developments and limitations to current RBC production practices.
Blood Substitutes ; Cost-Benefit Analysis ; Embryonic Stem Cells ; Erythrocytes* ; Fetal Blood ; Induced Pluripotent Stem Cells ; Stem Cell Research ; Stem Cells*

The number of umbilical cord blood transplantation is increasing worldwide as it has expanded the ability of the transplantaion community to meet the growing needs of their patients. Clinical data over the last decade show promising results in transplantation using both related as well as unrelated cord bloods. Cord blood banks are essential for the clinical use for transplantation and are now established around the world with the major efforts to standardize banking in collection, processing and distribution of cord blood for providing the highest quality stem cells for the patients. In Korea, Medipost, Histostem and some regional cord blood banks were established some years ago and collected thousands of cord blood for public but it had some limitations and was not expanded as the cord blood transplantation was not covered by medical insurance. Recently with the change in the policy of medical insurance to cover the cord blood transplantation, several venture companies are showing great interests in cord blood banking and trying to establish private cord blood banks in Korea. This review article discusses the current status of cord blood transplantaion and also the clincial use of stem cells from cord blood.
Fetal Blood* ; Humans ; Insurance ; Korea ; Stem Cells ; Transplantation ; Umbilical Cord*

Purpose: Long-term culture- initiating cells(LTC-IC) are stem cells that have the capacities of long-term engraftment and helping to establish hematopoietic microenvironment. For evaluation of the LTC-IC, we measured the counts and function with multidimentional flowcytometry in long-term culture media. METHODS: Samples were obtained from umbilical cord blood, leukapheresis products and bone marrow(BM). LTC-IC were counted with flowcytometric analysis using anti- CD34, anti-CD38, and anti-HLA-DR antibodies at 0, 5, and 8 weeks. Cell adhesion molecule related with stem cell were evaluated with flowcytometric analysis also using anti-VCAM-1(CD106) and anti-VLA-4(CD49d) at 0 and 8 weeks. RESULTS: The proportion of CD34+/CD38- cell from fractionated mononuclear cells at 0 week were 0.46%, 0.044%, and 0.038% for BM, leukapheresis products, and umbilical cord blood respectively and then rapidly decreased at 5 weeks, but still persisted at 8 weeks in all three groups. The proportion of CD34+/HLA-DR- cells was the same tendency to CD34+/CD38-. VCAM+ expression rate from fractionated CD34+ cells at 0 and 8 weeks were 67.3% and 40.2% for BM and 64.1% 44.2% for umbilical cord blood but it was very low 31.2% and 5.1% for leukapheresis products. VLA-4+ expression rate for fractionated CD34+ cells at 0 and 8 weeks were similar tendency to VCAM+ cells. CONCLUSION: This study suggest that the count of LTC-IC decreased with time but still persisted until 8 weeks. Umbilical cord blood including BM help to establish the hematopoietic microenvironments.
Antibodies ; Cell Adhesion ; Culture Media ; Fetal Blood ; Leukapheresis ; Stem Cells

PURPOSE: The umbilical cord blood has been considered as an alternative source of hematopoietic stem cells for transplantation. The CD34+ is known as a common stem cell antigen and the CD34+ CD38- immunophenotype reportedly defines a primitive subpopulation of progenitor cells. In this study the frequency of CD34+ and CD34+ CD38- hematopoietic stem/progenitor cells in placental/cord blood (UCB), and adult peripheral blood (PB) were determined. METHODS: Between July and September 1998, 27 collections of UCB were performed at the obstetric units of Hanyang University Hospital. Fifteen adult PB samples were also obtained for control. RESULTS: The frequency of total CD34+ cells in UCB was higher (1.13+/-0.58% vs 0.46+/-0.30%, P=0.0002) than PB and the frequency of CD34+ CD38- cells in UCB was also greater (0.02+/-0.02 vs 0.01+/-0.01, P=0.035) than PB. The majority of UCB- and PB-derived CD34+ cells expressed CD38- antigen (98.22+/-2.11% in UCB and 97.85+/-2.56% in PB). The frequency of CD38- expression by UCB derived CD34+ cells was slightly higher (not statistically significant) than that by PB derived CD34+ cells. The frequency of CD34+ cells was increased linearly with birth weight (r=0.413). CONCLUSION: These results suggest that UCB could be a useful source of highly primitive hematopoietic stem cells for marrow reconstitution after bone marrow ablation.
Adult* ; Birth Weight ; Bone Marrow ; Fetal Blood* ; Hematopoietic Stem Cells ; Humans ; Stem Cells