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Biomedical subjects

H D Preisler

Publications and source records attributed to H D Preisler.

At least 217 records · Page 12Linked to original sources
PubMed1981

A comparison of two methods for determining the sensitivity of human myeloid colony-forming units to cytosine arabinoside.

Studies were carried out to determine the optimal method for measuring the sensitivity of myeloid clonogenic cells to cytosine arabinoside (ara C). Bone marrow or peripheral blood cells were either exposed to different concentrations of ara C for 1 h in vitro and then after washing were plated in agar and cultured for 7 d in vitro, or were directly plated in agar containing different concentrations of the drug. The 3H-TdR suicide index of the clonogenic cells was also determined. Washing the specimens under study subsequent to incubation with ara C prior to plating in agar provided the most accurate measure of the ara C sensitivity of the clonogenic cells. When carried out in conjunction with the 3H-thymidine suicide index, the 'wash' method permitted the simultaneous determination of both the kinetic and metabolic sensitivity of these cells to ara C. Using this combined method, it was observed that the differences between the ara C sensitivity of the CFUc of different individuals resulted from differences in the proportion of clonogenic cells synthesizing DNA in the different marrow specimens.

Agar↗
PubMed1981

Treatment of refractory adult acute lymphocytic leukaemia and acute undifferentiated leukaemia with an anthracycline antibiotic and cytosine arabinoside.

Ten patients with acute lymphocytic leukaemia (ALL) and four patients with acute undifferentiated leukaemia (AUL) in relapse or refractory to conventional therapy were treated with remission induction therapy consisting of an anthracycline antibiotic and cytosine arabinoside. Twelve patients had previously demonstrated resistance to vincristine-prednisone and nine patients had prior anthracycline therapy. Nine patients achieved complete remission after one course of therapy with a median time to remission of 30 d. Of five nonresponders, three died of sepsis with marrow hypocellularity and no evidence of residual leukaemia. Only two patients had unequivocal evidence for resistance to an anthracycline-cytosine arabinoside regimen. Myelosuppression and infection were the most significant complications of therapy. The data presented indicate that marrow ablative chemotherapy with an anthracycline antibiotic and cytosine arabinoside is an effective regimen for remission induction in adults with ALL and AUL refractory to vincristine-prednisone. The use of these agents in remission consolidation therapy may offer the possibility of providing a reduction in residual resistant cells that are present after successful remission induction therapy with conventional agents.

Adolescent↗
PubMed1981

Clonal growth of leukaemic cells in vitro.

Human leukaemic cell specimens were obtained from patients and directly plated into soft agar (t = 0) or cultured for 1 week in liquid phase and then plated in soft agar. Growth for 1 week in liquid phase allowed the clonal growth in agar of leukaemic specimens which were unable to clone at t = 0. Clonal growth after liquid culture consisted of the usual leukaemic type of cluster-colonies, growth of a new type of 'syncytial' cell colony or a mixture of colony types. In addition, marrow from a patient with acute lymphocytic leukaemia produced normal-appearing colonies after 1 week of growth in liquid phase. These studies suggest a similarity in the growth requirements of some leukaemic cells and normal CFUd cells.

Adult↗
PubMed1981

Comparison between agar and methylcellulose cultures of human leukemic cells.

A comparison was made between the agar and methylcellulose culture systems with respect to their ability to support the clonal growth of leukemic cells obtained from patients with acute myeloblastic leukemia, acute lymphoblastic leukemia, and chronic myelogenous leukemia in blastic crisis. The number of clusters and/or colonies formed and the morphology of the cells within them varied from patient to patient. Nevertheless, no significant difference between the two culture systems within given leukemic specimens was found. No significant differences were noted among three different conditioned media used as sources of colony-stimulating activity. Most of the cells within clusters and colonies were identified to be immature members of granulocyte-macrophage series or to be indistinguishable from the preculture leukemic blast cells by morphological and cell surface marker studies. Cells from myeloid crisis in chronic myelogenous leukemia grew well in the cultures, but cells from lymphoid crisis did not proliferate.

Adult↗
PubMed1981

Characterization of proliferative and quiescent leukemic cells by flow cytometry.

Leukemic cells obtained from the peripheral blood and bone marrow of two patients were separated into kinetically active and kinetically quiescent subpopulations by centrifugal elutriation. The subpopulations of cells were compared to each other and to the parent populations by means of flow cytometry and autoradiography. The larger kinetically active subpopulation differed from the original unseparated cells and from the small cell population in containing a larger amount of RNA and having a greater proportion of cell in late G1. Subpopulations of large and equivalently sized cells obtained from the bone marrow and peripheral blood were compared and despite essentially identical size distributions the marrow cells were more kinetically active.

Bone Marrow Cells↗
PubMed1980

Acquisition of selected subpopulations of leukemic cells for study.

Neoplastic cells are frequently intermingled with normal cells in vivo in man and in laboratory animals. In addition, tumor cells frequently consist of functionally distinct cell subpopulations. We have used both centrifugal elutriation and electronic cell sorting to separate leukemic cells from nonleukemic hematopoietic cells and to separate kinetically distinct subpopulations of leukemia cells. In addition, methods have been developed to use pulse cytophotometry to detect the interaction of the anthracyclines with leukemic cells during exposure, both in vitro and in vivo.

Animals↗
PubMed1980

Prediction of response to chemotherapy in acute myelocytic leukemia.

Marrow specimens obtained from 23 patients with acute myelocytic leukemia were exposed to cytosine arabinoside and/or daunorubicin in vitro, and the effects of these agents on colony formation in vitro was determined. Thymidine suicide indices were determined as well, which permitted a distinction to be made between kinetic and metabolic resistance to cytosine arabinoside. The sensitivity of the colony-forming cells to the two chemotherapeutic agents did not correlate with each other, indicating that sensitivity to each was independently determined. The relationship between in vitro sensitivity to daunorubicin and cytosine arabinoside and response to 25 courses of in vivo therapy with these two agents administered to 21 patients was determined. These studies indicated a clear-cut relationship between in vitro drug sensitivity and in vivo response with patients whose leukemic cells were sensitive to both agents entering complete remission, whereas patients whose leukemic cells were insensitive to one or both drugs in vitro failed to enter remission.

Adolescent↗
PubMed1980

Effects of cytosine arabinoside on unseparated bone marrow and peripheral blood cells and on specimens enriched for myeloblasts and promyelocytes.

Myeloblast and promyelocyte enriched preparations and the original unseparated specimens were compared in regard to the phosphorylation of cytosine arabinoside (ara C) and the retention of ara CTP as well as the effects of ara C on the clonogenic cells. The immature cell-enriched preparations have a significantly higher rate of ara C phosphorylation, while retention of ara CTP is not significantly different from that of the unseparated cells. No correlation was found between the measured parameters of ara C metabolism and the drug's effects on the clonogenic cells in either cell population.

Blood Cells↗
PubMed1979

Growth of human acute myeloblastic leukemic (aml) cells in vitro.

Human normal and granulocytic leukemic progenitor cells produce colonies and clusters when cultured in the plasma clot system in vitro. The number of colonies formed and their cellular composition was comparable to that reported for the system (soft agar) usually used for these studies. The plasma clot system has the advantage of permitting in situ morphologic and cytochemical characterizaion of the cells within the colonies. A comparison was also made of the growth of leukemic cells in suspension cultures placed within conventional and modified Marbrook flasks. These studies demonstrated no advantage for the Marbrook system in cultures incubated for up to 7 days.

Culture Techniques↗