PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Cell Separation”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed1981

Buffy coat and cell separator granulocyte concentrates. Comparison of cell content and in vitro granulocyte function.

Buffy coat granulocyte concentrates were prepared manually from single fresh whole blood donations after centrifugation. The erythrocyte, granulocyte and platelet numbers in these concentrates were compared to cell numbers in concentrates obtained by mechanical leukapheresis using intermittent flow centrifugation. Buffy coats contained approximately half the number of granulocytes and three times the number of erythrocytes per unit volume than cell separator concentrates. There was no difference in platelet numbers. Thus to give a therapeutic dose of granulocytes equivalent to that obtained by cell separation, 2-3 times greater volume of buffy coat concentrates would be required. In vitro granulocyte function, as measured by migration, phagocytosis, and Candida killing was also compared in buffy coat and cell separator concentrates. The only difference found was reduced Candida killing in the buffy coat granulocytes. The possible clinical use of buffy coat concentrates, as a source of granulocytes, is discussed.

Blood Cell Count↗
PubMed1987

Magnetic affinity colloid (MAC) cell separation of leukemia cells from autologous bone marrow aspirates.

A colloidal suspension of Co2B with avidin irreversibly adsorbed to the surface has been used with biotinylated antibodies and lectins to eliminate specific cell populations from mixtures with peripheral blood or bone marrows. Using the monoclonal antibodies CF-1 and PM-81 with this magnetic affinity colloid (MAC), we can eliminate five logs of K562 cells from mixtures with peripheral blood or marrow cells as determined by a linear limiting dilution clonogenic assay. We have also used this separation to eliminate clonogenic leukemia cells from fresh samples of peripheral blood and bone marrow from relapsed acute leukemia patients. Using CF-1 alone or in combination with PM-81, we eliminated two logs of colonies and clusters of leukemia cells from the fresh samples. The same antibodies used with MAC separation of hematologically normal marrows allow recovery of greater than 30% of the hematopoietic progenitors.

Bone Marrow Cells↗
PubMed1997

Comparison of two blood cell separators in collecting peripheral blood stem cell components.

To ensure that a sufficient number of CD34+ cells are collected for an allogeneic blood progenitor cell transplant, the most effective blood cell separator should be used to collect peripheral blood stem cell (PBSC) components. We compared the effectiveness of two blood cell separators. We gave 29 healthy people 7.5 or 10 micrograms kg-1 of granulocyte colony stimulating factor (G-CSF) daily for 5 days and collected one PBSC component with either a Fenwal CS3000 (n = 15) or a Cobe Spectra (n = 14) blood cell separator. The volume of blood processed was the same for each machine (8.4 +/- 1.0 L; range = 4.9-9.4 L for the CS3000 and 8.9 +/- 1.0 L; range 6.7-10.9 L; P = 0.71). The components collected with the CS3000 contained more mononuclear cells (39.6 +/- 21.9 x 10(9) compared with 26.9 +/- 5.6 x 10(9), P = 0.02) and fewer neutrophils (1.38 +/- 1.88 x 10(9) compared with 5.53 +/- 8.71 x 10(9), P = 0.001). The total number of CD34+ cells collected with the two instruments was the same (470 +/- 353 x 10(6) for the CS3000 and 419 +/- 351 x 10(6) for the Spectra; P = 0.64) as was the number of CD34+ cells collected per litre of whole blood processed (55.9 +/- 42.0 x 10(6) L-1 compared with 45.9 +/- 37.9 x 10(6) L-1; P = 0.59). The mononuclear cell collection efficiency was greater for the CS3000 (82.4 +/- 54.9% compared with 53.3 +/- 14.1; P = 0.04) but the CD34+ cell collection efficiencies were the same (87.4 +/- 61.1% for the CS3000 compared with 56.3 +/- 23.5% for the Spectra; P = 0.07). In conclusion, both blood cell separators collected components which contained large numbers of CD34+ cells, but those collected with the CS3000 contained fewer neutrophils and the CS3000 was more efficient at collecting mononuclear cells.

Adult↗
PubMed1998

Theoretical analysis of cell separation based on cell surface marker density.

A theoretical analysis was performed to determine the number of fractions a multidisperse, immunomagnetically labeled cell population can be separated into based on the surface marker (antigen) density. A number of assumptions were made in this analysis: that there is a proportionality between the number of surface markers on the cell surface and the number of immunomagnetic labels bound; that this surface marker density is independent of the cell diameter; and that there is only the presence of magnetic and drag forces acting on the cell. Due to the normal distribution of cell diameters, a "randomizing" effect enters into the analysis, and an analogy between the "theoretical plate" analysis of distillation, adsorption, and chromatography can be made. Using the experimentally determined, normal distribution of cell diameters for human lymphocytes and a breast cancer cell line, and fluorescent activated cell screening data of specific surface marker distributions, examples of theoretical plate calculations were made and discussed.

Antigens, Surface↗
PubMed1983

Selective removal of sickle cells with the IBM 2997 continuous flow blood cell separator.

Partial red cell exchange transfusion is used to manage several complications of sickle cell anemia. Reports have stressed the safety, ease, and speed of red cell exchange procedures performed with blood cell separators, but little information exists concerning operating conditions for the most efficient removal of hemoglobin S (HbS) containing cells. We performed 13 red blood cell exchange transfusions with the IBM 2997 continuous flow blood cell separator on two previously transfused adult homozygous (SS) sickle cell patients. We used both a single stage and a dual stage disposable pathway and varied rotor speed, collection port, and collection interface independently. The patients' baseline percentage HbS ranged from 28 to 64% (mean = 46%); post exchange values ranged from 19.1 to 46% (mean = 32%). Thirty-three of 34 specimens collected from the white cell or platelet port showed a higher percentage of HbS in the collection line compared to simultaneous patient samples. Mean enrichment was 9.4% (range = -4.0 to 35.5%). There was an inverse relationship between the hemoglobin concentration and the percentage of HbS in the collected specimens (p = 0.001; N = 45). Differential separation of sickle cells should decrease the volume of blood required for partial red cell exchange of selected SS patients.

Anemia, Sickle Cell↗
PubMed1994

E-cadherin distribution in interleukin 6-induced cell-cell separation of ductal breast carcinoma cells.

E-cadherin is expressed in both the ZR-75-1-Tx and the ZR-75-1-Ro sublines of ductal breast carcinoma cells and is concentrated at cell-cell borders as shown by immunocytochemical examination. Free cell borders generally show no or little staining. The localized decrease in E-cadherin expression observed after interleukin 6 (IL-6) treatment of either subline correlates with the increase in free cell borders as IL-6 causes cell-cell separation. As we previously reported, many IL-6-treated ZR-75-1-Tx cells round up and detach from the substratum while ZR-75-1-Ro cells remain adherent and display prominent processes. The results are consistent with the view that E-cadherin expression is not responsible for the marked difference in the IL-6-induced phenotypes in these cell lines, although the localized decrease may play a role in cell-cell separation. ZR-75-1-Tx cells are deficient in desmosomes and show a wider intercellular space than ZR-75-1-Ro cells. Alternative mechanisms involving different aspects of the interlinked cytoskeletal and cell adhesion structures are considered to account for the IL-6-induced antimorphogenetic effect.

Antibodies, Monoclonal↗
PubMed2005

[Comparison of the effect of Cobe Spectra and Fenwal CS 3000 plus blood cell separators in collection of peripheral blood stem cell components].

To evaluate the hematopoietic stem/progenitor cell apheresis effect of Cobe Spectra (Version 6.1) and Fenwal CS 3000 Plus cell separators, fourty-two procedures on twenty donors using Cobe Spectra cell separator and twenty-two procedures on sixteen donors using Fenwal CS 3000 Plus cell separator were retrospectively analyzed. The number of CD34(+) cells collected, the collection efficiency (CE) of CD34(+) cells and the contaminations of red blood cell and platelet in the stem/progenitor cell products of two devices were compared. The results showed that there were no significant differences in the total number of CD34(+) cells collected and the CD34(+) cell CE between the two devices. There were positive correlations between the count of peripheral blood cells including leukocyte, monocyte, hematopoietic progenitor cell and CD34(+) cell after mobilization and the total number of CD34(+) cells collected. The stepwise multiple variable analyses revealed the peripheral blood stem/progenitor cell count emerged as the only significant independent predictive factor for CE. A negative correlation was seen between the peripheral blood monocyte count and the CD34(+) cell CE for the Fenwal CS 3000 Plus. The Fenwal CS 3000 Plus product contained more red blood cells than that of the Cobe Spectra. The decrease in the peripheral platelet count after Fenwal CS 3000 Plus apheresis was also greater. It is concluded that collection efficacy of Cobe Spectra (Version 6.1) and Fenwal CS 3000 Plus was similar. Cobe Spectra shall be used preferably to assure higher CD34(+) cell CE at a high peripheral blood monocyte count. The Cobe Spectra cell separator is better for the donors with mismatched blood type and the donors with thrombocytopenia.

Antigens, CD34↗
PubMed1974

Studies on dispersed pancreatic exocrine cells. II. Functional characteristics of separated cells.

The functional characteristics of separated guinea pig pancreatic exocrine cells have been examined following dissociation of the gland by a procedure described in the previous paper (J. Cell Biol. 1974. 63:1037). The ability of isolated cells to incorporate labeled amino acids into secretory proteins was assessed biochemically and by quantitative electron microscope autoradiography. Incorporation remained linear for up to 4-h incubation at levels equivalent to those of pancreatic slices; over 95% of the exocrine cells in the population were viable, and all appeared to be equally active in incorporating amino acids. The capacity of separated cells to transport, concentrate, and store exportable proteins was monitored by electron microscope autoradiography on populations pulse labeled with [(3)H]leucine and chase incubated for 4 h. The same overall pathway previously mapped in pancreatic slices was followed by secretory proteins in separated cells although in quantitative studies a defect was noted in the rate of conversion of condensing vacuoles to zymogen granules. Secretogogue responsiveness was assessed by monitoring discharge of labeled secretory proteins or of amylase in response to carbamylcholine and caerulein to the medium. While the separated cells released secretory proteins linearly for up to 4 h in response to both secretogogues, the net release was approximately 50% less than previously noted for pancreatic slices and required a ten times higher concentration of stimulant. The defect may represent alteration in receptors due to the protease used for dissociation. Our data indicate, however, that separated exocrine cells retain their ability to process secretory proteins stepwise and vectorially which is consistent with preservation of structural polarity.

Amylases↗
PubMed1998

Purging and haemopoietic progenitor cell selection by CD34+ cell separation.

Tumour cell contamination of autologous peripheral blood stem cell samples (PBSC) and bone marrow (BM) is frequent. Enrichment of CD34+ stem cells is a promising approach to purging tumour cells from autografts without damaging progenitor cells. Breast cancer cells were seeded (10(-3)-10(-7)) into mononuclear cells from G-CSF-mobilised PBSC and BM harvests from patients without breast cancer. CD34+ cells were enriched from mixtures either by immunomagnetic separation (Isolex-50, and MiniMACS) or by biotin-streptavidin immunoaffinity columns (Ceprate-LC). CD34+ cell fractions were determined by FACS, cancer cells were detected immunocytochemically with an anti-pancytokeratin antibody. The CD34+ cells were enriched with a median purity of 92.2% (43.5-96.1) (n = 17) (Isolex-50), 96.5% (66.6-99.2) (n = 17) (MiniMACS) and 77.9% (31.4-93.6) (n = 15) (Ceprate-LC) from PBSC and BM harvests. The percentages of median recovery of CD34+ cells were 30.8% (18.6-71.8) (Isolex-50), 69.9% (39.1-100) (MiniMACS) and 42.9% (23.7-100) (Ceprate-LC). The median tumour cell reductions in log steps were 3.7 (2.9-4.3) (n = 13) (Isolex-50), 3.5 (2.6-4.3) (n = 13) (MiniMACS) and 1.5 (0.9-2.9) (n = 17) (Ceprate-LC). Results were compared statistically by univariate analysis. Purity was significantly (P < 0.05) better after MiniMACS selection. Recovery rates were significantly different between all devices tested. Tumour cell purging was superior after immunomagnetic separation (P < 0.001). Tumour cell purging is a main objective of CD34+ selection in the autologous setting. Our in vitro data clearly indicate that immunomagnetic separation is more efficient in the prevention of accidental reinfusion of contaminating tumour cells compared to immunoaffinity. However, it is not yet known if the same results can be obtained with fresh contaminating tumour cells.

Antigens, CD34↗
PubMed1996

Production of IL-8 and IL-4 by positively and negatively selected CD4+ and CD8+ human T cells following a four-step cell separation method including magnetic cell sorting (MACS).

Highly enriched CD4+ and CD8+ human T cells were obtained from peripheral blood using a relatively simple and inexpensive method consisting of four steps: separation of mononuclear cells on Lymphoprep, removal of adherent monocytes by incubation in plastic petri dishes, removal of B cells, NK cells and further depletion of nonadherent monocytes by panning with anti-CD19, -CD16, -CD14, -CD11b and -CD33 mAb, and separation of CD4+ and CD8+ T lymphocytes by magnetic cell sorting (MACS). Cell culture for up to 48 h showed preservation of function by both positively and negatively selected cells as determined by production of IL-8. Although the cell separation procedure had no effect on interleukin-2 receptor (IL-2R, CD25) expression, it induced production of IL-4 by both T cell subsets selected positively, implying cell activation by ligation of CD4 and CD8 molecules. Irrespective of the mode of separation, CD8+ T cells produced more IL-4, a cytokine which is associated with a Th2-type cytokine profile of CD4+ T cells. We conclude that our method for separating T cells into their CD4+ and CD8+ subsets results in high cell purities with preservation of function, as determined by cytokine generation. If enriched cells are to be used for functional studies we recommend isolation by negative selection which has less effect on cell function. The relevance of the finding that CD8+ T cells can be an important source of IL-4 remains to be elucidated.

CD4-Positive T-Lymphocytes↗
PubMed2005

Cell separation between mesenchymal progenitor cells through porous polymeric membranes.

This study investigates the separation of two types of marrow stromal cells, KUSA-A1 osteoblasts and H-1/A preadipocytes, by filtration through various porous polymeric membranes. It was found that KUSA-A1 permeates better than H-1/A cells through 12-microm polyurethane foaming membranes. This appears to be due to the relatively smaller cell size of KUSA-A1 cells. In addition, when feed solutions containing suspensions of either cell type or a mixture of the two were used, the permeation ratio was relatively low (< 6%) through polyurethane and surface-modified polyurethane foaming membranes. It was also found that there was some degree of separation between KUSA-A1 and H-1/A cells (separation factor = 1.8) with nylon-net filter membranes, but no separation was obtained when filters made of nonwoven fabrics or silk screens were used. This ability of the nylon-net filter membranes to separate the two cell types was due to a sieving effect that results from an optimal pore size. Finally, permeation of a solution of human serum albumin through the membrane following filtration of the cells did not result in a separation of cells in the recovery solution.

Adipocytes↗
PubMedDate not supplied

Harvest of young red cells on an automated cell separator.

Red cells can be fractionated by age on a blood processor (Model 2991, IBM). However, little data exist on processing a product for transfusion. This report details a method for collecting young erythrocyte (YE) units containing a mean hemoglobin content of 56.43 +/- 1.39 (SEM) grams. Enrichment with YEs was indicated by greater activity of the enzyme pyruvate kinase (PK) in aliquots of YE units. The mean ratio of PK activity in the young red cell product compared to unfractionated blood was 1.14 +/- 0.03 (SEM). An increased PK ratio was noted in 23 of 26 units studied. Based on the PK ratio, the mean age of the erythrocytes was 46 days, compared to 60 days for standard units of blood. In the 6 units assayed, the reticulocyte count was increased. Collection of YE units was relatively easy, no untoward donor reactions were observed, and no deleterious effects developed in the recipient. Although these data suggest enrichment with a young population of red cells, YE units produced by this method are experimental. Routine use of this procedure awaits demonstration of a significant decrease in transfusion frequency in patients receiving YE units for chronic red cell therapy.

Bloodletting↗
PubMedDate not supplied

Analysis of physical parameters of discrete cell populations. (Double data control by combining specific density and sedimentation velocity cell separation techniques).

Physical cell separations are employed in a number of investigations in cell biology, immunology, haematology, etc., when the study of homogeneous cell populations is required. Differences in physical characters are reflected in the various functions and differentiation stages of the individual cell lines, which can be concentrated and separated into discrete cell classes by these methods. The correct utilization of the separation techniques mainly depends on the knowledge of the physical laws on which they are based. This paper discusses the theoretical background and a practical application of a combined separation procedure which uses velocity sedimentation and linear density gradient and also gives a double check of the physical data obtained in the different experiments. As an example of this analysis, cells from the lymph nodes of Hodgkin's patients were separated, and the physical parameters as well as some sources of 'error' in the experimental results obtained with these 'Hodgkin's cells' are reported and discussed.

Cell Separation↗
PubMed1988

Separation of mononuclear bone marrow cells using the Cobe 2997 blood cell separator.

In the present study, we report the results of our evaluation of the use of the continuous-flow cell separator Cobe 2997 to isolate from human bone marrow (BM) aspirates the mononuclear cell (MNC) fraction containing hematopoietic stem cells. This MNC concentrate is isolated in 15% of the original BM volume and contains 23% of the initial nucleated cells. It is enriched as concerns the BM MNC fraction (lymphocytes + monocytes recovery; 80%), whereas the contamination with granulocytes, red blood cells and platelets is reduced to 7.2, 1.5% and 41%, respectively, of the cells initially present in the BM suspensions. Furthermore, it is demonstrated that this MNC concentrate is highly enriched in granulocyte-macrophage-colony-forming cells (CFU-GM; recovery 83%). The method is simple, inexpensive, efficient and reproducible. It allows rapid processing of a large volume of BM without substantial loss of hematopoietic progenitor cells. It represents a valuable method of BM MNC concentration prior to further in vitro manipulations such as T cell or tumor cell depletion or cryopreservation.

Adolescent↗