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Cell Enrichment (cell + enrichment)
Selected AbstractsInvestigating the Feasibility of Stem Cell Enrichment Mediated by Immobilized SelectinsBIOTECHNOLOGY PROGRESS, Issue 6 2007Nichola Charles Hematopoietic stem cell therapy is used to treat both malignant and non-malignant diseases, and enrichment of the hematopoietic stem and progenitor cells (HSPCs) has the potential to reduce the likelihood of graft vs host disease or relapse, potentially fatal complications associated with the therapy. Current commercial HSPC isolation technologies rely solely on the CD34 surface marker, and while they have proven to be invaluable, they can be time-consuming with variable recoveries reported. We propose that selectin-mediated enrichment could prove to be a quick and effective method for recovering HSPCs from adult bone marrow (ABM) on the basis of differences in rolling velocities and independently of CD34 expression. Purified CD34+ ABM cells and the unselected CD34, ABM cells were perfused over immobilized P-, E-, and L-selectin-IgG at physiologic wall shear stresses, and rolling velocities and cell retention data were collected. CD34+ ABM cells generally exhibited lower rolling velocities and higher retention than the unselected CD34, ABM cells on all three selectins. For initial CD34+ ABM cell concentrations ranging from 1% to 5%, we predict an increase in purity ranging from 5.2% to 36.1%, depending on the selectin used. Additionally, selectin-mediated cell enrichment is not limited to subsets of cells with inherent differences in rolling velocities. CD34+ KG1a cells and CD34, HL60 cells exhibited nearly identical rolling velocities on immobilized P-selectin-IgG over the entire range of shear stresses studied. However, when anti-CD34 antibody was co-immobilized with the P-selectin-IgG, the rolling velocity of the CD34+ KG1a cells was significantly reduced, making selectin-mediated cell enrichment a feasible option. Optimal cell enrichment in immobilized selectin surfaces can be achieved within 10 min, much faster than most current commercially available systems. [source] Marginal zone B cell enrichment and strong follicular B cell reduction correlate with a delayed IgG response in a light chain diversity restricted mouse modelEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 10 2004Yacine Abstract Recently developed B6.,,,SEG mice (by crossing ,, and C57BL/6 mice congenic for the wild Mus spretus SEG strain , locus lacking genes coding for ,1 and ,3) have a very reduced light chain diversity. B6.,,,SEG mice produce only ,2 and ,x light chains. Regardless of their Igh haplotype, B6.,,,SEG mice show a restricted B cell distribution by light chain subtype with ,x dominance in all peripheral compartments except peritoneal cavity where ,2 is dominant. This distribution suggests that selection mechanisms act differently in different B cell compartments on ,2 and ,x bearing B cells. Sequence analysis before or following immunization did not reveal unusual mechanisms of diversification. B6.,,,SEG mice still respond to various challenging antigens using new Ab patterns. In particular, regardless of Igha or Ighb haplotypes, the anti-2,4-dinitrophenyl response is characterized by a restricted diversity for both heavy and light chains and a delayed IgG response when compared to B6 and B6.,, mice. We suggest that the delayed IgG response is due to the expansion of marginal zone B cells whereas follicular B cells are strongly reduced. [source] Influence of obstetric factors on the yield of mononuclear cells, CD34+ cell count and volume of placental/umbilical cord bloodJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 1 2010Atsuko Omori Abstract Aim:, Placental/umbilical cord blood (CB) has been used increasingly not only for transplantations, but also in the field of life science research. However, little information is available on the biological characteristics of CB units collected in rural areas because no medical facilities are affiliated with CB banks. Little attention has been paid to the collection of CB units in rural areas compared to CB collected in metropolitan areas. CB is a precious source for life science research due to the recent low birth rate in Japan. Therefore, to efficiently utilize CB units, the purpose of the present study was to investigate the optimum obstetric factors associated with a higher yield of mononuclear/CD34+ cells per CB unit. Methods:, CB units were collected at a single hospital (Hirosaki National Hospital). A total of 126 CB units from 105 vaginal deliveries and 21 cesarean section deliveries were available for cell separation within 24 h. Mononuclear low-density (LD) cells were separated using Ficoll-Paque and then processed for CD34+ cell enrichment using magnetic cell sorting. Associations between the maternal/neonatal factors and the yield of LD/CD34+ cells were analyzed. Results:, Despite the larger net weight of CB collected from cesarean section deliveries, the total number of LD cells collected from vaginal deliveries was significantly higher than that collected from cesarean section deliveries. The total number of LD cells per CB unit from primigravidae was significantly higher compared with that collected from from multigravidae. Conclusion:, CB units from vaginal deliveries of primigravidae may be more favorable because they contain a higher yield of mononuclear cells. [source] Investigating the Feasibility of Stem Cell Enrichment Mediated by Immobilized SelectinsBIOTECHNOLOGY PROGRESS, Issue 6 2007Nichola Charles Hematopoietic stem cell therapy is used to treat both malignant and non-malignant diseases, and enrichment of the hematopoietic stem and progenitor cells (HSPCs) has the potential to reduce the likelihood of graft vs host disease or relapse, potentially fatal complications associated with the therapy. Current commercial HSPC isolation technologies rely solely on the CD34 surface marker, and while they have proven to be invaluable, they can be time-consuming with variable recoveries reported. We propose that selectin-mediated enrichment could prove to be a quick and effective method for recovering HSPCs from adult bone marrow (ABM) on the basis of differences in rolling velocities and independently of CD34 expression. Purified CD34+ ABM cells and the unselected CD34, ABM cells were perfused over immobilized P-, E-, and L-selectin-IgG at physiologic wall shear stresses, and rolling velocities and cell retention data were collected. CD34+ ABM cells generally exhibited lower rolling velocities and higher retention than the unselected CD34, ABM cells on all three selectins. For initial CD34+ ABM cell concentrations ranging from 1% to 5%, we predict an increase in purity ranging from 5.2% to 36.1%, depending on the selectin used. Additionally, selectin-mediated cell enrichment is not limited to subsets of cells with inherent differences in rolling velocities. CD34+ KG1a cells and CD34, HL60 cells exhibited nearly identical rolling velocities on immobilized P-selectin-IgG over the entire range of shear stresses studied. However, when anti-CD34 antibody was co-immobilized with the P-selectin-IgG, the rolling velocity of the CD34+ KG1a cells was significantly reduced, making selectin-mediated cell enrichment a feasible option. Optimal cell enrichment in immobilized selectin surfaces can be achieved within 10 min, much faster than most current commercially available systems. [source] Telomerase activity in disseminated prostate cancer cellsBJU INTERNATIONAL, Issue 6 2006JESCO PFITZENMAIER OBJECTIVE To analyse telomerase activity in disseminated prostate cancer cells isolated from bone marrow aspirates taken from men with localized prostate cancer before radical prostatectomy (RP). PATIENTS AND METHODS Disseminated epithelial prostate cancer cells were isolated from bone marrow aspirates from 69 men with localized prostate cancer before RP, by magnetic column-chromatography enrichment, followed by isolation of fluorescently labelled epithelial cells by micropipetting. We used pools of 10 non-epithelial bone marrow cells after tumour cell enrichment as control samples. These pure cell pools were tested for the presence of telomerase activity. RESULTS In all, 49 of the patient samples contained disseminated prostate cancer cells. Homogeneous pools of 10 cells were obtained from 35 of these; 49% of the 35 specimens showed telomerase activity, whereas all five control samples did not. Telomerase activity in the 35 samples was not significantly associated with Gleason score, preoperative prostate-specific antigen level, tumour stage, or surgical margin status. Follow-up is continuing to assess an association with disease recurrence. CONCLUSION This work shows the feasibility of isolating disseminated cancer cells for analysing individual or pooled cells. Compared to tissue staining, where telomerase is detected in 80,90% of samples, we found lower rates of telomerase activity in the disseminated tumour cells (49%). Telomerase-negative cells might provide information about cell dormancy, as telomerase is a marker of cell proliferation in immortal and cancer cells. Telomerase-positive cells might predict early disease recurrence, but a longer follow-up is needed to test this possibility. [source] Use of magnetic enrichment for detection of carcinoma cells in fluid specimensCANCER, Issue 1 2002Eric Kielhorn B.S. BACKGROUND Ascites fluid or a pleural effusion are common events in metastatic carcinoma, but they also can be associated with several other medical conditions. The standard for determination of malignancy in these situations is cytologic evaluation of these fluids. Although this method is frequently successful, there are times when it fails, even when the patient has a malignancy, either because of insufficient cells in the fluid or for other reasons. This study addresses this problem taking advantage of the recent advances in technology for detection of rare epithelial cells in liquid specimens. METHODS The authors examined fluid specimens from 59 patients to determine the frequency of recovery of epithelial cells compared with that achieved by conventional cytopathology. The Dynal CELLection Epithelial Enrich (Dynal AS, Oslo, Norway) method was used. This method is based on immunomagnetic selection of cells binding to EpCAM antibodies. Carcinoma cells were confirmed by morphology and, when there was sufficient material, by E-cadherin staining. RESULTS Grouping the cases by cytologic diagnosis, the authors found malignant cells using the cell enrichment assay in 11 of 12 malignant cases, 2 of 5 atypical cases, and 3 of 42 negative cases. Further investigations were conducted on the five cases that were cytologically negative or atypical but yielded epithelial cells after immunomagnetic enrichment. Four cases ultimately were proven malignant by other methods and one had incomplete follow-up. CONCLUSIONS The new methods available for epithelial cell enrichment in liquids may be used successfully on cytologic fluid specimens and may lead to increased sensitivity for detection of malignancy, and consequently more accurate staging. Cancer 2002;94:205,11. © 2002 American Cancer Society. [source] | ||||||||||