Search PubMed⌕ Search

Biomedical subjects

M Symann

Publications and source records attributed to M Symann.

At least 73 records · Page 4Linked to original sources

Effect of lithium on diffusion chamber granulopoiesis.

We studied the effect of lithium on diffusion chamber (DC) granulopoiesis. When DC loaded with bone marrow cells were implanted into the peritoneal cavity of mice previously injected with lithium carbonate, more proliferative and nonproliferative granulocytes were produced as compared to DC implanted into control hosts. The number of DC CFU-c was increased significantly in the lithium-treated group, but there was no difference in the number of DC CFU-s. Levels of DC fluid CSF showed no evident correlation with DC myelopoiesis. These data suggest that a humoral factor other than CSF mediates the action of lithium in DC granulopoiesis, and that lithium's influence on DC hematopoietic stem cell proliferation occurs mainly at the CFU-c level.

Animals↗

Leukocyte membrane proteins in chronic lymphocytic leukemia, as studied by two-dimensional gel electrophoresis.

We evaluated protein expression in leukocytes from 20 patients with chronic lymphocytic leukemia (CLL), including one with the rare T-cell form of the disease. To identify proteins that potentially could be used to characterize leukemia or as candidates for new markers of differentiation, we studied cell and membrane extracts from these leukemic cells. We used immune precipitation and extraction of integral membrane proteins with Triton X-114 to identify known proteins on the surface of these cells. Extraction with Triton X-114 in the presence of protease inhibitors yielded reproducible membrane extracts, which we examined by two-dimensional gel electrophoresis. Of the approximately 2000 proteins or protein subunits so resolved from cell lysates and the 450 from membrane extracts of leukocytes from patients with T- and B-cell CLL, we were able to identify spots corresponding to the proteins designated by the OKT.4 and OKT.10 antibodies, the human class I and II histocompatibility antigens, beta 2-microglobulin, and surface IgM. We also defined sets of proteins that are characteristically expressed on the membranes of leukemic T or B cells, some of which correspond to previously defined markers of normal leukocyte subpopulations.

Aged↗

In vivo induction of granulopoiesis in visceral yolk-sac cells by foetal hepatic factors.

In order to evaluate the hypothetical activity of foetal hepatic factors on putative yolk-sac haemopoietic stem cells we used the Double Diffusion Chamber (DDC) techniqUe. The DDC were made of a regulator compartment, where foetal hepatic tissue was introduced and a test compartment where visceral yolk-sac cells were cultured. In this system a hepatic signal induced the yolk-sac stem cells to differentiate along the granulocytic pathway but did not stimulate yolk-sac CFUs growth. Contrary to CFUs originating from foetal liver or adult bone marrow, yolk-sac CFUs do not increase numerically in diffusion chamber culture.

Animals↗

"Spontaneous" erythroid progenitor cells in the circulation and monosomy 7 in juvenile chronic myelogenous leukemia.

Cytogenetic examination of bone marrow cells from two patients with juvenile chronic myelogenous leukemia (JCML) showed a monosomy 7. Peripheral blood from these two children was found to contain large numbers of cells capable of erythroid colony formation in tissue culture without added erythropoietin. We conclude that erythroid progenitor cells are part of the malignant clone in JCML.

Child, Preschool↗

In vivo stimulation and inhibition of granulopoiesis: the effect of an inflammatory reaction on murine diffusion chamber granulopoiesis.

Humoral factors influencing granulopoiesis have been evaluated using diffusion chambers (DC) implanted in the peritoneal cavity of mice challenged by an aseptic abscess produced by the subcutaneous implantation of copper rods. This resulted in an increase in peripheral blood neutrophils and an increase in tibial granulocytic elements. When DC loaded with bone-marrow cells were implanted into mice stimulated the day before by an aseptic abscess significantly more CFU-s, CFU-c, proliferative and non-proliferative granulocytes were produced, as compared to DC implanted into control hosts. When DC were implanted 4-6 d after the induction of inflammation in mice a significant depression of DC granulopoiesis was observed. Levels of serum and DC fluid CSF and serum inhibitors of in vitro colony growth showed no correlation with DC myelopoiesis. The data show that mice undergoing an inflammatory reaction elaborate first humoral substance(s) enhancing CFU-s and granulocytic growth in DC and next inhibitory factor(s) of DC granulopoiesis.

Animals↗

Myeloid stem cell kinetics in children hypertransfused during remission induction of acute lymphoblastic leukemia.

Experimental studies in animals and recent preliminary clinical evidence raised the possibility that hypertransfusion might be capable of producing a beneficial effect on granulopoiesis recovery following irradiation or chemotherapy. This prompted us to design a study to determine the effect of hypertransfusion on the blood and marrow CFU-c of leukemic children during remission induction. Nineteen children with acute lymphoblastic leukemia have been randomized in pairs to normotransfused (Hb: 12-14 g/dl) and hypertransfused (Hb: 16-18 g/dl) groups. Anti-leukemic chemotherapy (vincristine and adriamycin weekly during 4 weeks and prednisone daily) was identical in all children. As expected, suppression of erythropoiesis was observed in the hypertransfused group. During the first three courses of chemotherapy, the number of marrow CFU-c remained very low in both groups. One week after the third course of chemotherapy the number of bone marrow CFU-c began to increase in both groups. One week after course four the CFU-c value was significantly larger in the hypertransfused group. We also observed that circulating CFU-c were almost absent before induction chemotherapy, whereas their number increased after course three and was higher in the hypertransfused group and remained higher after course four. These results show the kinetics of bone marrow recovery after chemotherapy and suggest that hypertransfusion increases the rate of recovery of granulopoiesis.

Adolescent↗

Selective hypoplasia of pelvic bone marrow.

6 patients with thrombocytopenia and anaemia had fatty marrow replacement at the site of an iliac crest. 52Fe scans showed marked abnormalities of bone marrow distribution. Particularly, the uptake of radioiron into the pelvis was almost absent. The sternal marrow was cellular. Studies of the bone marrow which included cytology, histology and electron microscopy failed to reveal why the pelvic marrow was aplastic. Occasional vascular lesions could not seen in the iliac crest bone marrow sections. The cellular morphology showed slight maturation abnormalities. Ferrokinetics were consistent with erythroid marrow hypoplasia. The pelvic and sternal marrow cellularity in patients with pancytopenia may not be representative of the cellularity of the whole marrow, and the pelvic marrow especially may be prone to aplasia.

Adult↗

The diffusion chamber technique as an in vivo assay in mice for the effectiveness of antitumor agents.

The diffusion chamber (DC) technique has been applied to the culture of L1210 cells in view of determining their sensitivity to chemotherapic agents. The surviving fraction of L1210 cells cultivated in DC's 4 d after i.v. injection of the host mice with 10 mg/kg of daunorubicin or daunorubicin-DNA was 40% and 9% respectively. The results suggest that the DC technique could be a useful in vivo predictive test for cancer chemotherapy.

Animals↗

Effects of daunorubicin and doxorubicin, free and associated with DNA, on hemopoietic stem cells.

We have compared daunorubicin (DNR)-DNA with free DNR and doxorubicin (DOX)-DNA with free DOX for their effects in vivo in mice on pluripotent stem cells and granulocytic committed stem cells. Dose-survival, time-survival, and recovery curves were obtained after one i.v. injection of either drug. The dose-survival curves of colony-forming units-spleen (CFU-S) and colony-forming units-committed stem cells (CFU-C) were exponential in shape with both agents. DNR-DNA appeared more toxic to the hemopoietic precursor cells than did free DNR. In contrast, DOX-DNA was less toxic toward CFU-S and as toxic as DOX toward CFU-C. Time-survival curves indicated a minimum level of CFU-S and CFU-C at about 33 hr. After that, the recovery of CFU-S was rapid for DNR-treated mice but remained below 50% of the controls on Day 12 for the DNR-DNA-treated group. In mice previously given injections of DOX or DOX-DNA, the recovery of the CFU-S was more protracted in time with a better recovery in mice treated with DOX-DNA. Both DNR and DNR-DNA induced an initial CFU-C decrease followed by a rapid but transient rise with a maximum on Day 4 after chemotherapy. On Day 12, the CFU-C recovery was still incomplete in both DNR- and DNR-DNA-treated mice. In the groups treated with DOX, the CFU-C recovery was more important after DOX-DNA complex than after free DOX. The results are discussed in view of the "lysosomotropic chemotherapy" hypothesis.

Animals↗

Murine yolk sac hematopoiesis studied with the diffusion chamber technique.

The proliferation and differentiation of visceral and of parietal yolk sac cells from 9-day-old mouse embryos were studied in diffusion chambers (DC). After culture, the visceral yolk sac yielded predominantly macrophages whereas the parietal yolk sac displayed mainly plasmocyte-like cells. It is shown the latter do not synthesize immunoglobulin but rather elaborate Reichert's membrane. Neither visceral nor parietal yolk sac contained detectable pluripotent stem cells (CFUs) prior to or after DC culture, a finding which is discussed in the light of the current literature.

Animals↗

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.

Agranulocytosis↗

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.

Animals↗

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.

Animals↗

Retroviral-mediated transfer of genes encoding interleukin-2 and interleukin-12 into fibroblasts increases host antitumor responsiveness.

The transfer of genes encoding cytokines into tumor cells has emerged as a new strategy to increase in vivo host reactivity to a variety of tumors. Because gene transfer into tumor cells cannot be easily applied in the clinical setting, we have developed an experimental model of gene transfer into fibroblasts and examined the capacity of these engineered cells to elicit an antitumor immune response. Interleukin-12 (IL-12) is a heterodimeric cytokine with pleiotropic activities presenting strong antitumor and antimetastatic effects in murine models. A bicistronic retroviral vector was constructed that contained the cDNAs encoding both chains (p40 and p35) of murine IL-12 separated by an internal ribosomal entry site sequence. Syngeneic cutaneous fibroblasts obtained from newborn mice and transduced to secrete either IL-12 or IL-2 were injected subcutaneously with B16F0 or B16F1 melanoma cells. The time of tumor occurrence and overall survival of mice were significantly prolonged when B16F1 cells were coinjected with cytokine-producing fibroblasts compared with B16F1 alone or B16F1 together with unmanipulated fibroblasts. Systemic effects were seen in the mice injected with either IL-2- or IL-12-secreting fibroblasts, with the highest proliferation capability and interferon-gamma production observed in vitro from splenocytes from recipients of IL-2-secreting fibroblasts. Injection of IL-2-secreting fibroblasts or coinjection of IL-2- and IL-12-producing fibroblasts resulted in a significant increase of survival in the B16F0 model; in some cases, complete disease eradication was observed. These results suggest that cutaneous fibroblasts represent a target of choice for gene transfer and would be useful in the treatment of minimal residual disease in humans.

Animals↗