Growth patterns of human acute lymphoblastic leukaemia in diffusion chambers befor treatment and after cessation of therapy.

Diffusion Chambers (DC) were used to culture human bone marrow of ALL patients at the beginning and after the cessation of therapy. No growth was observed in patients before treatment, while growth patterns similar to the normal were obtained in patients after 3 years of maintenance therapy. We suggested the possibility of intensifying the multiple drug chemotherapy in ALL without permanent damage of the stem cell proliferative compartment.

Growth and differentiation patterns of human acute non lymphoid leukemia in diffusion chambers before and after treatment.

Diffusion chambers (DC) were used to culture bone marrow of ANLL patients firstly at the onset, secondly in complete remission and thirdly in the relapse of the disease. At the onset of the disease an increase in cellular concentration mainly due to the granulocytic differentiation was observed in DC in all ANLL patients, in contrast to no growth in ANLL patients in complete remission and in relapse. The DC technique reveals a marked pathological pattern of proliferation in every phase of ANLL, at the presentation, in complete remission and in relapse.

Fetal hemopoiesis in diffusion chamber cultures: II. Cell proliferation and differentiation.

The growth and differenciation of hemopoietic cells from murine fetal liver (FL) and adult bone marrow (ABM) in diffusion chambers (DC) implanted into normal CF1 mice were evaluated. Initially FL suspensions were approximately 90% erythrocytic, but after 4 days in DC implanted into either normal or phenylhydrazine (anemic) pretreated hosts, growth was essentially restricted to the granulocyte-macrophage cell types. The number of in vitro colony forming cells (CFC), as assayed in a double layer soft-agar technique was determined after varying periods of growth in DC of both ABM and FL. Both groups showed a progressive decline in CFC number. FL and ABM CFC generated the same proportion of different morphologic types of soft agar colonies. After 7 days of DC culture, there was a decrease in the proportion of macrophage colonies from both groupes. During DC culture the ratio of clusters (3-50 cells to colonies progressively increased in both groups suggesting a parent-progeny relationship between CFC and cluster forming cells. The results of these studies provide further evidence that the environment rather than properties intrinsic to murine stem cell determines the pattern of proliferation.

Fetal hemopoiesis in diffusion chamber cultures. III. The effect of neutropenia.

Proliferation and differentiation of granulocytes, macrophages, and both myeloid committed (CFC) and pluripotent (CFU) stem cells in diffusion chamber (DC) cultures of fetal liver were studied in order to evaluate the role of circulating humoral factors in the control of fetal myelopoiesis. When DC with fetal liver cells were implanted into mice rendered neutropenic by pretreatment with cyclophosphamide, more granulocytes and CFC were produced through day 10 as compared to DC implanted into saline pretreated control hosts. A difference in CFU recovery from fetal liver suspensions grown in DC implanted into neutropenic and control hosts was not seen until day 10. Serum CSF concentrations were increased in neutropenic as compared to control host mice 2 and 3 days after implantation of DC. Levels of serum inhibitors of colony growth showed marked variability but, in general, were similar in both groups. These data provide evidence that fetal CFC and fetal myelopoiesis are influenced by a circulating humoral factor present in neutropenic serum. CSF may be the factor, although the data presented in this paper do not establish this with any certainty.

Fetal hemopoiesis in diffusion chamber cultures. I. The pattern of pluripotent stem cell growth.

The growth pattern of fetal liver (FL), normal adult bone marrow (NABM) and regenerating (post Velban treatment) adult bone marrow (RABM) colony forming units (CFU) cultured in diffusion chambers (DC) was studied. When twenty CFU were implanted into DC the recovery of CFU after 4 days with FL, NABM or RABM was 133 +/- 7, 19 +/- 2 and 34 +/- 2 CFU, respectively. The transplantation fraction of CFU from NABM decreased from 10-4% on day 0 to 6-9% on day 4; that of FL did not change from the initial 6-2%. The growth rate of CFU derived from FL was substantially greater than that from NABM. The relative growth of FL and RABM CFU was clearly inhibited when the concentration of cells cultured was increased. Spleen colonies from FL cells before culture were larger (P less than 0-005) than colonies from NABM but after 7 days of culture there was no difference between the two groups. Histological examination of spleen colonies showed that after DC culture FL and NABM CFU were differentiating along the three normal pathways. These data suggest that intrinsic differences exist between fetal and adult stem cells in the in vivo diffusion chamber culture system.