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Biomedical subjects

A A Fauser

Publications and source records attributed to A A Fauser.

At least 109 records · Page 6Linked to original sources
PubMed1984

Tumor colony formation from human spontaneous tumors in a methylcellulose monolayer system.

A methylcellulose monolayer system is described that facilitates the "in vitro" cultures of human spontaneous tumor cells. The tumor samples were disaggregated mechanically and cultured in 0.9% methylcellulose with 30% fetal calf serum in Iscove's modified Dulbecco's medium. Eighty-five individual tumor samples with different histological types were seeded, 45 gave rise to tumor cell colonies. The plating efficiency ranged from 0.02% to 0.22%. Cytologic and cytochemical staining from aspirated cells revealed the same morphology of cells as the cells in the suspension. A flattening of colonies, as it has been described by others using methylcellulose monolayer, was not observed.

Clone Cells↗
PubMed1984

Stimulatory activities for human multilineage hemopoietic progenitors (CFU-GEMMT) derived from patients with hemochromatosis and from normal volunteers.

A medium conditioned by leukocytes in the presence of phytohemagglutinin (PHA-LCM) promotes the growth of human multilineage hemopoietic progenitors (CFU-GEMMT) which form mixed hemopoietic colonies in culture containing granulocytes, erythroblasts, megakaryocytes, macrophages, and T-lymphocytes. PHA-LCM derived from six HLA-typed patients with idiopathic hemochromatosis and from six normal individuals were tested for growth-promoting activities for multilineage hemopoietic colony formation. Four out of six conditioned media obtained from patients with hemochromatosis supported mixed hemopoietic colony formation, as did four of six conditioned media from normal HLA-typed volunteers. Active PHA-LCM preparations from patients with hemochromatosis were similar with respect to the number and size of mixed colonies and their cellular composition when compared with conditioned media obtained from volunteers. The study indicates that no link exists between the HLA phenotype of a particular donor and the predictability of obtaining an active PHA-LCM promoting multilineage hemopoietic colony formation. PHA-LCM derived from patients with hemochromatosis had no advantage with respect to stimulatory activity for mixed colony formation when compared with conditioned media obtained from healthy volunteers.

B-Lymphocytes↗
PubMed1984

Interference of a human leukocyte interferon preparation with stimulatory activities in leukocyte-conditioned medium for human hematopoietic stem cells.

Medium conditioned by leukocytes in the presence of phytohemagglutinin (PHA-LCM) promotes the growth of multilineage hemopoietic progenitors derived from human bone marrow. However, PHA-LCM prepared in the presence of a human leukocyte interferon preparation does not support mixed colony formation. Crude PHA-LCM preparations were characterized by gel filtration, affinity chromatography, and gel electrophoresis. The elution profile on Sephacryl S-300 of PHA-LCM prepared without interferon showed a distinct peak that stimulated the growth of pluripotent stem cells (CFU-gemm) and committed precursors (CFU-c, BFU-e). Gel filtration of PHA-LCM, prepared with 1000 U/ml of interferon, revealed a change in the elution profile. The eluted material demonstrated no growth-promoting activities. We conclude that the abolished stimulatory activity of PHA-LCM, prepared with human leukocyte interferon, might be due to a reduced production of stimulatory molecules, suggesting that interferon interferes with the molecular events required for colony formation of committed and noncommitted hemopoietic progenitors.

Cell Division↗
PubMed1983

Reticulocytopenia in severe autoimmune hemolytic anemia (AIHA) of the warm antibody type.

A patient with severe AIHA of the warm antibody type, absence of reticulocytes and red cell hyperplasia of the bone marrow is described. In order to maintain a reasonable hemoglobin level 38 units of washed packed red cells were required within 24 days. The treatment with high doses of steroids showed no permanent beneficial effect. After splenectomy the red cell destruction was immediately reduced and the patient went into a remission. Bone marrow culture studies during the acute phase of the disease and at the time of complete hemato- and immunological remission, i.e. 4 months after splenectomy suggested a circulating autoantibody directed to early erythroid progenitors (BFU-E). The inhibitory activity in the patient's plasma did not influence granulocytic or mixed colony formation (CFU-GEMM). In addition to autoantibodies directed to erythroblasts and erythropoietin involved in the pathogenic mechanisms leading to red cell aplasia type I and II the culture studies suggest an unusual autoantibody that might cause the observed reticulocytopenia and erythropoietic hyperplasia of the bone marrow in AIHA. After the splenectomy the patient recovered, he required no further blood transfusions and his disease has not recurred.

Adult↗
PubMed1983

Fetal hemoglobin analysis of erythroid bursts in patients with chronic myelogenous leukemia (CML).

Early erythroid progenitors (BFUE) form colonies of mature progeny in culture. The development of hemoglobinized red cells within multilineage colonies (CFUGEMM) and erythroid bursts is dependent upon exogenously added erythropoietin and molecules released by hemopoietic subpopulations. Mixed colonies and erythroid bursts were grown from 3 patients with Ph' chronic myelogenous leukemia (CML). It was found that some mixed hemopoietic colonies and erythroid bursts did not require exogenously added erythropoietin. An increase of the plating efficiency of BFUE could be observed when erythropoietin was added. Erythroid bursts grown without added Ep from samples of the patients with chronic myelogenous leukemia have a higher probability to contain HbF than clones grown in the presence of Ep. The data support the view of a phenotypical heterogeneity among clonal descendents of a common ancestor as previously postulated for CML.

Adult↗
PubMed1983

Characterization of stimulatory activity for human pluripotent stem cells (CFUGEMM).

A medium conditioned by leukocytes in the presence of phytohemagglutinin (PHA-LCM) promotes the growth of human multilineage hemopoietic progenitors CFUGEMM which form mixed hemopoietic colonies in culture containing granulocytes, erythroblasts, megakaryocytes, macrophages and mononuclear cells with T-cell antigens. In addition PHA-LCM supports the growth of erythroid bursts (BFUE) and granulocytic colonies (CFUC). Stimulatory activities of PHA-LCM were characterized by gel filtration using Sephacryl S 300. The eluted growth promoting activities were rechromatographed on Sepharose 4 B covalently linked with Lentil Lectin. The stimulatory activities for noncommitted precursors CFUGEMM, and committed progenitors BFUE, and CFUC were detected in the unretained material i.e. the activities revealed no affinity to Lentil-Lectin. The apparent molecular weight of these stimulatory molecules ranged from 35,000-45,000, as determined by SDS gel electrophoresis (PAGE).

Bone Marrow Cells↗
PubMed1982

Suppressor T-cell clones derived from pluripotent stem cells (CFU-GEMM) of a patient with Hodgkin's lymphoma.

Pluripotent stem cells (CFU-GEMM) give rise to multilineage hemopoietic colonies in culture. The cellular composition revealed that mixed colonies contain cells of different myeloid lineages and mononuclear cells with T-cell surface antigens. T-lymphocytes of primary colonies, replated secondary and tertiary colonies from a patient with Hodgkin's Lymphoma were identified by their reaction with the monoclonal antibody OKT 8. Evidence for a common progenitor of myeloid and lymphoid cells is provided by analysis of individual secondary and tertiary colonies using OKT 3, OKT 4, OKT 8, VIM-D 5, and Ig M + D antibodies for each individual colony. Primary mixed, replated secondary and tertiary colonies revealed OKT 8 positive cells. No reaction with OKT 3, OKT 4, VIM-D 5, or Ig M + D was observed.

Antibodies↗
PubMed1982

Identification of human megakaryocytes derived from pure megakaryocytic colonies (CFU-M), megakaryocytic-erythroid colonies (CFU-M/E), and mixed hemopoietic colonies (CFU-GEMM) by antibodies against platelet associated antigens.

Pure megakaryocytic colonies, megakaryocytic-erythroid colonies and mixed hemopoietic colonies can be cultured from human bone marrow under appropriate culture conditions. Human plasma and mercaptoethanol support the growth for these different types of hemopoietic colonies. However, the addition of medium conditioned by leucocytes in the presence of phytohemagglutinin (PHA-LCM), as a source of thrombopoietin, is required for the formation of megakaryocytic colonies or megakaryocytes within mixed colonies. Megakaryocytes were identified by their typical morphological appearance in culture. Pure megakaryocytic colonies, megakaryocytic-erythroid colonies and mixed colonies were plucked by micropipette and analysed by the PAP-slide technique using antibodies to human factor VIII-related protein or serum derived from a patient with posttransfusion purpura; this particular serum demonstrated anti-P1A1 antibody activity. These antibodies might provide an excellent probe to identify megakaryocytic progeny from committed and non-committed hemopoietic progenitors, facilitating studies of early events in megakaryopoiesis.

Antibodies↗
PubMed1982

Effect of interferon on pluripotent hemopoietic progenitors (CFU-GEMM) derived from human bone marrow.

A culture assay for multilineage hemopoietic progenitors (CFU-GEMM) that form mixed hematopoietic colonies containing granulocytes, erythroblasts, megakaryocytes and macrophages was described. The effect of human leukocyte interferon on multilineage hemopoietic progenitors was examined. Leukocyte interferon does reduce the plating efficiency of noncommitted precursors (CFU-GEMM) in a dose related fashion. A reduction of the plating efficiency of mixed hemopoietic colonies was observed even when interferon was added 72 hours after initiation of the cultures.

Bone Marrow Cells↗
PubMed1982

Cytotoxic T-cell clones derived from pluripotent stem cells (CFU-GEMM) of patients with Hodgkin's lymphoma.

Pluripotent stem cells (CFU-GEMM) give rise to multilineage hemopoietic colonies in culture. The cellular composition revealed that mixed colonies contain cells of different myeloid lineages and mononuclear cells with T-cell surface antigens. T lymphocytes of primary colonies and replated secondary clones from 5 patients with Hodgkin's lymphoma (stage I--II) were identified by their reaction with the monoclonal antibody OKT-8. Replated secondary clones do act functionally as cytotoxic cells using K562 as target cells. Evidence for a common progenitor of myeloid and lymphoid cells is provided by analysis of individual secondary colonies with the use of OKT-3, OKT-4, OKT-8, VIM-D5, and IgM + D antibodies for each individual clone. Primary mixed and replated secondary colonies revealed OKT-8-positive cells. No reaction with OKT-3, OKT-4, VIM-D 5, or IgM + D was observed. In mixed colonies grown from putative bone marrow transplant donors, only OKT-3-positive cells could be observed. Secondary replated colonies did not stain for OKT-8 and failed to lyse 51Cr-labeled K562 cells.

Antibodies, Monoclonal↗
PubMed1981

Stimulatory activity of PHA-LCM for normal human hemopoietic progenitors and leukemic blast cell precursors: separation by isoelectric focusing.

Medium conditioned by leukocytes in the presence of phytohemagglutinin (PHA-LCM) promotes growth of human hemopoietic progenitors (CFU-GEMM, BFU-E, CFU-C) and precursors of leukemic blast cells. PHA-LCM was separated by isoelectric focusing and each fraction tested with nonadherent cells of normal individuals as well as blast cells from two patients with acute myelogenous leukemia. Activity profiles for CFU-GEMM, BFU-E and CFU-C ranged form pH 5.0-6.5. The profile for activity stimulatory for leukemic blast cells was broader and ranged from pH 5.5-7.5. Although some overlap was observed, the main peaks of stimulatory activity for normally differentiating progenitors and precursors of leukemic blast cells were separable with respect to their isoelectric point.

Bone Marrow↗
PubMed1981

Pluripotent hemopoietic progenitors (CFU-GEMM) in polycythemia vera: analysis of erythropoietin requirement and proliferative activity.

Pluripotent hemopoietic progenitors (CFU-GEMM) give rise to multilineage hemopoietic colonies in culture. We have examined the erythropoietin requirements of CFU-GEMM-derived erythroid progeny in patients with polycythemia vera (PV) and studied their proliferative activity by short-term exposure to 3HTdR. Mixed colonies with erythroid components were observed in all bone marrow and peripheral blood samples from patients with PV that were cultured without addition of exogenous erythropoietin. This response is consistent with previously reported growth patterns for CFU-E and BFU-E. The frequency of mixed colonies increased regularly when erythropoietin was added to the cultures. Short-term exposure of peripheral blood specimens to 3HTdR prior to plating yielded a reduction of the plating efficiency by 20%-70% when compared to cells that were not exposed to 3HTdR. The observation of cycling CFU-GEMM in PV contrasts with the usually quiescent behavior of CFU-GEMM in peripheral blood of normal individuals under steady-state conditions. These results support the view that the increased proliferative rate observed for CFU-GEMM may be responsible for the increased formation of blood cells in PV.

Bloodletting↗