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C Almici

Publications and source records attributed to C Almici.

At least 19 recordsLinked to original sources
PubMed1995

Isolation of small, primitive human hematopoietic stem cells: distribution of cell surface cytokine receptors and growth in SCID-Hu mice.

Human CD34+ cells were subfractionated into three size classes using counterflow centrifugal elutriation followed by immunoadsorption to polystyrene cell separation devices. The three CD34+ cell fractions (Fr), Fr 25/29, Fr 33/37, and Fr RO, had mean sizes of 8.5, 9.3 and 13.5 microns, respectively. The majority of cells in the large Fr RO CD34+ cell population expressed the committed stage antigens CD33, CD19, CD38, or HLA-DR and contained the majority of granulocyte-macrophage colony-forming units (CFU-GM), burst-forming units-erythroid (BFU-E), and CFU-mixed lineage (GEMM). In contrast, the small Fr 25/29 CD34+ cells were devoid of committed cell surface antigens and lacked colony-forming activity. When seeded to allogeneic stroma, Fr RO CD34+ cells produced few CFU-GM at week 5, whereas cells from the Fr 25/29 CD34+ cell population showed a 30- to 55-fold expansion of myeloid progenitors at this same time point. Furthermore, CD34+ cells from each size fraction supported ontogeny of T cells in human thymus/liver grafts in severe combined immunodeficient (SCID) mice. Upon cell cycle analyses, greater than 97% of the Fr 25/29 CD34+ cells were in G0/G1 phase, whereas greater proportions of the two larger CD34+ cell fractions were in active cell cycle. Binding of the cytokines interleukin (IL)-1 alpha, IL-3, IL-6, stem cell factor (SCF), macrophage inhibitory protein (MIP)-1 alpha, granulocyte colony-stimulating factor (G-CSF), and granulocyte-macrophage (GM)-CSF to these CD34+ cell populations was also analyzed by flow cytometry. As compared with the larger CD34+ cell fractions, cells in the small Fr 25/29 CD34+ cell population possessed the highest numbers of receptors for SCF, MIP1 alpha, and IL-1 alpha. Collectively, these results indicate that the Fr 25/29 CD34+ cell is a very primitive, quiescent progenitor cell population possessing a high number of receptors for SCF and MIP1 alpha and capable of yielding both myeloid and lymphoid lineages when placed in appropriate in vitro or in vivo culture conditions.

Animals↗
PubMed1994

Identification of Philadelphia-negative granulocyte-macrophage colony-forming units generated by stroma-adherent cells from chronic myelogenous leukemia patients.

Chronic myelogenous leukemia (CML) is a clonal disorder of the hematopoietic stem cell characterized by the coexistence of Philadelphia-negative (Ph-) with Ph+ progenitors. CML progenitor cells have been shown to be defective in adherence to marrow stroma. The present study investigated at the cytogenetic level marrow-derived CML clonogenic cells generated from the stroma-adherent cell fraction. On direct cytogenetic analysis, the overall mean (+/- SEM) percentage of Ph- metaphases was 3% +/- 1%. Mononuclear marrow cells from CML patients (n = 18) were incubated with mafosfamide (100 micrograms/mL) or control medium, seeded onto marrow stromal layers and allowed to adhere (2 hours, 37 degrees C). After a short-term (3-day) liquid culture, the cells were harvested, incorporated in methyl-cellulose, and individual colonies were analyzed by single colony karyotyping. The mean (+/- SEM) percentage of Ph- colonies generated from the stroma-adherent fraction was 35% +/- 6%. As compared with marrow colony-forming unit granulocyte-macrophage plated before any manipulation, the mean (+/- SEM) percentage of Ph- clones was significantly increased by stroma adherence (35% +/- 6% v 15% +/- 4%, P < or = .005) and mafosfamide (100 micrograms/mL) incubation of marrow cells before stroma adherence (58% +/- 9% v 35% +/- 6%, P < or = .005). An additive effect was observed by combining mafosfamide treatment and stroma adherence. Single-colony transfer experiments showed that 50% +/- 4% stroma-adherent and 70% +/- 4% stroma-adherent mafosfamide-treated progenitors gave rise to secondary colonies. To further characterize the stroma-adherent fraction, experiments were performed in which CD34+ marrow cells were used. The mean (+/- SEM) output of progenitors generated by 10,000 CD34+, stroma-adherent cells was 888 +/- 188 and 570 +/- 258 for untreated and mafosfamide-treated cells, respectively. Individual colonies were analyzed by single-colony karyotyping and fluorescent in situ hybridization using a biotinylated cosmid DNA probe that hybridize to abl oncogene. The CD34+, stroma-adherent fraction contained 38% +/- 14% (untreated) and 56% +/- 18% (mafosfamide-treated) (P < or = .025) Ph- progenitors. In conclusion, the present data show the possibility to select Ph- clones that (1) have a maintained capability of stroma adherence, (2) are mafosfamide resistant, (3) are derived from the CD34+ fraction, and (4) have high-replating potential.

Adult↗
PubMed1992

Use of recombinant human granulocyte-macrophage colony-stimulating factor in patients with lymphoid malignancies transplanted with unpurged or adjusted-dose mafosfamide-purged autologous marrow.

The neutropenia-related morbidity and mortality occurring after autologous bone marrow transplantation (ABMT) is increased by marrow purging procedures. While phase I through III clinical trials showed the enhancing activity of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) on neutrophil recovery after ABMT with unpurged marrow, controversial results have been reported when purged marrow was used. Therefore, it was the aim of the present study to evaluate the efficacy of rhGM-CSF administration in a group of patients (n = 15) with lymphoid malignancies transplanted in complete remission with mafosfamide-purged (n = 10) or unpurged (n = 5) marrow. Mafosfamide concentrations used for marrow purging were evaluated on an individual basis by means of a recently described technique that destroys the granulocyte-macrophage (granulocyte-macrophage colony-forming units [CFU-GM]) compartment, but spares 50% of the more primitive stroma adherent colony-forming cells (CFU-Blast). rhGM-CSF (10 micrograms/kg/d) was started within 24 hours of ABMT and administered in a 4-hour infusion daily until the absolute neutrophil count (ANC) reached 500 x 10(6)/L and then for 7 more days. Patients receiving mafosfamide-purged or unpurged marrow failed to show any difference in terms of median number of days required to achieve an ANC > or = 500 x 10(6) (13 v 14.0, P > .4) cells/L. As compared with retrospective controls, granulocytic recovery was reduced by a median time of 11 (P < or = .0005) and 5 (P < or = .0005) days for patients grafted with purged and unpurged marrow, respectively. The number of CFU-GM (mean +/- SD) infused per kilogram of body weight was significantly lower in patients who received purged autografts as compared with those receiving unpurged autografts (0.85 +/- 0.79 x 10(4) v 15.7 +/- 9.2 x 10(4), P < or = .0005). The dose of CFU-GM progenitors infused per kilogram of body weight did not correlate (r = .031, P > .05) with the time required to reach an ANC > or = 500 x 10(6) cells/L. The number of CFU-Blast (mean +/- SD) infused per kilogram of body weight was not significantly different between patients who received purged or unpurged autografts (5.05 +/- 2.51 x 10(3)/kg v 6.18 +/- 2.66 x 10(3)/kg, P < or = .375). A statistically significant correlation (r = -.658, P < or = .05) was observed between the number of CFU-Blast infused and the number of days required to reach an ANC > or = 500 x 10(6) cells/L.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1992

Counterflow centrifugal elutriation: experimental and clinical applications.

Counterflow centrifugal elutriation (CCE) separates mixed cell populations into distinct subpopulations, on the basis of different sedimentation characteristics, without impairment of cell function or yield. The advantages of this technique are the high recovery and viability of fractionated cells, as well as the rapidity and the reproducibility of results. CCE alone, or in combination with other separation methods, can provide homogeneous populations of cells for further investigations. Recently, CCE was employed in clinical studies aimed at preventing graft-versus-host disease in bone marrow transplant recipients, by depleting lymphocytes prior to bone marrow infusion. This article reviews the principles of elutriation and describes the possible experimental and clinical applications of this technique, which seems suitable for both peripheral blood (PB) and bone marrow (BM) separation.

Bone Marrow Transplantation↗
PubMed1992

Differential sensitivity of adherent CFU-blast, CFU-mix, BFU-E, and CFU-GM to mafosfamide: implications for adjusted dose purging in autologous bone marrow transplantation.

The availability of an in vitro assay able to detect hematopoietic progenitor cells closely related to those responsible for marrow engraftment following autologous bone marrow transplantation (ABMT) prompted us to establish a procedure aimed at maximally increasing the concentration of the cyclophosphamide derivative mafosfamide used for marrow purging. It, therefore, was the aim of the present study to investigate in a group of patients with acute nonlymphoblastic leukemia (ANLL; n = 19) and acute lymphoblastic leukemia (ALL; n = 19) in complete remission the effect of mafosfamide at the level of adherent blast colony-forming units (blast colony-forming units, CFU-Blast), as well as multipotential (granulocyte erythrocyte macrophage megakaryocyte colony-forming units, CFU-GEMM), erythroid (erythroid burst-forming units, BFU-E), and granulocyte-macrophage (granulocyte-macrophage colony-forming units, CFU-GM) progenitor cells. When nonadherent marrow mononuclear cells (MNCs) were incubated (30 min, 37 degrees C) with increasing doses of mafosfamide (30-120 micrograms/ml), a statistically significant (p less than or equal to 0.0005) dose-dependent suppression of CFU-Blast growth was observed. The mean (+/- 1 standard error of the mean [SEM]) values of 50% inhibition (ID50) of the CFU-Blast growth were not significantly different for ANLL (106 +/- 5) and ALL (107 +/- 5) patients. Analysis of CFU-Blast ID50 distribution demonstrated that ID50 ranged from 100 to 120 micrograms/ml in 17 cases (45%), whereas it ranged from 60 to 100 micrograms/ml in 12 cases and from 120 to 160 micrograms/ml in 9 cases. A statistically significant (p less than or equal to 0.05), dose-dependent suppression of colony growth from multi-potential and lineage-restricted progenitor cells was also observed. However, the value of CFU-Blast ID50 was significantly higher (p less than or equal to 0.05) than CFU-GEMM, BFU-E, and CFU-GM ID50 and ID95 values. In conclusion, our data demonstrate that: 1) the CFU-Blast assay allows to detect on an individual basis the doses of mafosfamide used for marrow purging, and 2) the concentrations of mafosfamide extrapolated by using the CFU-Blast assay are significantly higher than those obtained with the CFU-GM assay. The absence of any detrimental effect on marrow engraftment in vivo supports the safety of the CFU-Blast assay to evaluate the dose of mafosfamide used for marrow purging before ABMT.

Antineoplastic Agents↗
PubMed1991

In vitro marrow purging in chronic myelogenous leukemia: effect of mafosfamide and recombinant granulocyte--macrophage colony-stimulating factor.

Clinical and experimental evidence revealing Ph1-negative hematopoietic stem cells in the majority of chronic myelogenous leukemia (CML) patients, suggests that autologous bone marrow transplantation (ABMT) may represent a therapeutic approach for these patients. It was the aim of the present study to evaluate the efficacy of the cyclophosphamide derivative mafosfamide as a marrow purging agent in a group (n = 15) of CML patients. Chemical purging was followed by a short-term liquid culture phase supplemented with recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF). Mafosfamide (100 micrograms/ml) incubation induced a marked inhibition of progenitor cell growth, the percentages of surviving CFU-GEMM, BFU-E, and CFU-GM being 3.4, 5.4, and 4.9, respectively. At the cytogenetic level, the purging procedure failed to show any modulating effect on Ph1-negative clones in 9/15 cases. In contrast, 6/15 cases showed a significant increase in the mean (+/- SD) percentage of Ph1-negative metaphases in response to rGM-CSF (46 +/- 26, p less than or equal to 0.05), mafosfamide incubation (53 +/- 12, p less than or equal to 0.01), and the combination of mafosfamide incubation plus rGM-CSF (63 +/- 29, p less than or equal to 0.025). Immunological analysis revealed that mafosfamide incubation induced a significant enrichment of MY10 (28 +/- 9, 0.05) B73.1-positve cells (25 +/- 9, p less than or equal to 0.05). Four mafosfamide-responsive patients with CML in second chronic phase have been autografted with mafosfamide purged marrow. In all patients a Ph1-negative phase lasting 5-14 months was observed. In conclusion, it appears that (a) in a subgroup of CML patients mafosfamide purging is effective in reducing the size of the malignant clone and might induce through its cytotoxic and immune actions a modification of the balance between leukemic and normal clones, and (b) this experimental approach may be used as a screening test to select patients to undergo marrow harvest and ABMT with mafosfamide purged marrow.

Adult↗
PubMed1990

Growth of CD34+ acute myeloblastic leukemia colony-forming cells in response to recombinant hematopoietic growth factors.

In order to minimize the interactions of clonogenic cells with accessory cells and characterize the direct effect of recombinant hematopoietic growth factors (HGF) on acute myelogenous leukemia colony-forming cells (AML-CFU), the response of CD34+ AML-CFU to individual or combined recombinant HGF, i.e., interleukin-1 (IL-1), interleukin-3 (IL-3), interleukin-6 (IL-6), granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF), and macrophage colony-stimulating factor (M-CSF), was studied in 10 patients and compared with the growth response obtained from unfractionated marrow cells. IL-3 and GM-CSF had a similar stimulating activity on AML-CFU growth. G-CSF resulted the most efficient stimulus for colony formation and was additive or synergistic with IL-3 and GM-CSF, M-CSF, used alone, had a negligible stimulating activity. When CD34+ cells were used, IL-1 by itself had a low stimulating activity and displayed little or no synergy with IL-3, GM-CSF, and G-CSF. On the contrary, when unfractionated cells were used, IL-1 was very effective in inducing AML-CFU formation and was markedly synergistic with IL-3 and GM-CSF. These results show that IL-1-induced leukemic colony formation is prevalently mediated by accessory cells. IL-6 supported AML-CFU growth in seven of 10 cases, thus showing a direct effect on CD34+ leukemic cells, and enhanced the growth of IL-3-(+47 to +167%) and GM-CSF-dependent (+60 to +110%) AML-CFU. Recloning studies of single colonies demonstrated that primary CD34+ AML-CFU, stimulated by IL-3 and GM-CSF, generated secondary and tertiary colonies, whereas primary AML-CFU stimulated by G-CSF and IL-6 failed to give rise to secondary colonies, thus indicating a complete suppression of self-renewal. Sequential recloning of colonies grown in the presence of IL-3 + IL-6 demonstrated that addition of IL-6 and IL-3-containing plates resulted in a nearly complete suppression of self-renewal. In conclusion, these results demonstrate the heterogeneity of the CD34+ leukemic cell fraction and indicate the existence of complex regulatory events at the level of CD34+ leukemic cells. Data obtained from recloning experiments are of therapeutic interest in view of the clinical application of HGFs in the treatment of myeloid leukemias.

Adult↗
PubMed1983

[Use of digitalis in geriatrics: is it effective on the heart in sinus rhythm?].

The therapeutic activity of digitalis in cardiac failure is linked to its positive inotropic effect on the myocardium and its ability to control cardiac activity in atrial fibrillation. Chronic stimulation with digoxin in aged subjects with sinus rhythm, however, is of debatable utility Reference is made to a series of 35 subjects (mean age 76.5 yr) in sinus rhythm, 30 of whom had been taking digoxin for over 3 yr. Clinical and instrumental parameters were assessed and heart function was classified according to the NYHA arrangement. Subjects were randomly placed in two groups matched for sex, age and cardiac condition. The first group received digoxin, the second a placebo. No significant differences between the two groups were noted over a 3-month period. In keeping with the recent literature, it is felt that digitalis is not necessary for the dynamic cardiac control of aged subjects in sinus rhythm. In addition, it is suggested that hydrosaline retention in such subjects can be controlled by restriction of salt intake, rest and diuretics.

Aged↗