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M T Petrucci

Publications and source records attributed to M T Petrucci.

At least 19 recordsLinked to original sources
PubMed2005

Beyond single pathway inhibition: MEK inhibitors as a platform for the development of pharmacological combinations with synergistic anti-leukemic effects.

The MEK/MAPK signaling module is a key integration point along signal transduction cascades that regulate cell growth, survival, and differentiation, and is aberrantly activated in many human tumors. In tumor cells, constitutive MAPK activation affords increased proliferation and resistance to apoptotic stimuli, including classical cytotoxic drugs. In most instances, however, MAPK inhibition has cytostatic rather than cytotoxic effects, which may explain the lack of objective responses observed in early clinical trials of MEK inhibitors. Nevertheless, amenability of the MAPK pathway to pharmacodynamic evaluation and negligible clinical toxicity make MEK inhibitors an ideal platform to build pharmacological combinations with synergistic antitumor activity. In AML, the MEK/MAPK pathway is constitutively activated in the majority of cases (75%), conferring a uniformly poor prognosis; in preclinical models of AML, MEK blockade profoundly inhibits cell growth and proliferation and downregulates the expression of several anti-apoptotic players, thereby lowering the apoptotic threshold. Apoptosis induction, however, requires concentrations of MEK inhibitors much higher than those required to inhibit proliferation. Nevertheless, MEK blockade efficiently and selectively sensitizes leukemic cells to sub-optimal doses of other apoptotic stimuli, including classical cytotoxics (nucleoside analogs, microtubule-targeted drugs, gamma-irradiation), biologicals (retinoids, interferons, arsenic trioxide), and, most interestingly, other signal transduction/apoptosis modulators (UCN-01, STI571, Bcl-2 antagonists). In most instances, these MEK inhibition-based combinations result in a striking pro-apoptotic synergism in preclinical models. Here we briefly discuss evidence suggesting that MAPK pathway inhibition could play a prominent role in the development of integrated therapeutic strategies aimed at synergistic anti-leukemic effects.

Animals↗
PubMed2003

High-dose hydroxyurea in the treatment of poor-risk myeloid leukemias.

The aim of the study was to evaluate the antileukemic effectiveness and toxicity of high-dose hydroxyurea (HHY) and to assess its acute toxicity. Between August 1997 and October 1998, 12 consecutive adult patients (>18 years) with high-risk acute myeloid leukemia (AML) (four patients in first early relapse, seven patients with secondary AML, and one patient with de novo AML concomitant to a lymphoproliferative disorder) were enrolled to receive a single course of HY (100 mg/kg per day) until bone marrow aplasia or for a maximum of 30 days. Of the 12 patients, 5 (41.6%) achieved complete remission (CR), 1 achieved partial remission (PR), 4 were resistant to treatment, and 2 died during induction from infection. No patient with relapsed AML achieved CR, while it was achieved by five of eight patients with secondary AML at diagnosis; five of six MDR1+ patients achieved CR. As concerns follow-up of the CR patients, one did not receive any further treatment and died in CR from pulmonary aspergillosis, and one with a concomitant chronic lymphocytic leukemia (CLL) received two courses of FLAG (fludarabine, cytarabine, granulocyte colony-stimulating factor) regimen with disappearance of the clonal Ig rearrangement, but relapsed after 11 months and died from pneumonia. The remaining three patients were consolidated with two courses of high-dose cytosine arabinoside (AraC), followed by peripheral blood stem cell transplantation (PBSCT) in one patient. One of them relapsed after 3 months, while the other two are still in continuous complete remission (CCR) after 16 and 28 months, respectively. This study has demonstrated the safety and efficacy of HHY in inducing CR in AML patients with unfavorable prognosis. Despite the small number of patients, these encouraging results warrant further studies.

Adult↗
PubMed2001

Reduced susceptibility to apoptosis correlates with kinetic quiescence in disease progression of chronic lymphocytic leukaemia.

The role of apoptosis and cell kinetics in the mechanisms of disease progression of chronic lymphocytic leukaemia (CLL) is still unclear. In the present study, we investigated the susceptibility of leukaemic cells taken from 75 CLL patients with either stable (STD) or progressive disease (PRD) to enter apoptosis. Particular attention was paid to the relationship between cell cycle status and autologous serum (AS). The susceptibility to enter apoptosis was significantly greater in STD than in PRD, both in standard medium (mean = 23.62% +/- 14.7 versus 14.23% +/- 7.2; P = 0.02) and in the presence of AS (mean = 23.03% +/- 17.9 versus 11.27% +/- 7.6; P = 0.01). Furthermore, cell kinetics studies revealed a higher quiescence in PRD than in STD cases, both in terms of a lower RNA content (P = 0.04) and of higher expression of the negative cell cycle regulator p27kip1 (P = 0.03). These kinetic differences were confirmed by short-term in vitro culture both in fetal calf serum and in AS. The results of this study indicate that CLL cells from PRD cases are characterized by a higher degree quiescence and much lower susceptibility to apoptosis when compared with STD ones. In this context, AS does not appear to play a specific role. The association between these kinetic characteristics and disease progression in CLL prompts further studies to establish whether higher quiescence may be responsible for the decreased susceptibility of PRD cells to enter apoptosis.

Adult↗
PubMed2001

Prolonged molecular remission in advanced acute promyelocytic leukaemia after treatment with gemtuzumab ozogamicin (Mylotarg CMA-676).

We report a patient with acute promyelocytic leukaemia (APL) who received two doses of gemtuzumab ozogamicin for advanced disease. Previous treatments included front-line all-trans retinoic acid and anthracyclines, polychemotherapy consolidation, salvage chemotherapy for the first relapse followed by autologous stem cell transplantation (ASCT), arsenic trioxide for the second relapse followed by a second ASCT and then high-dose methotrexate for more advanced systemic disease with central nervous system involvement. The patient achieved prolonged haematological and molecular remission after monotherapy with gemtuzumab ozogamicin given at the time of the third relapse.

Adult↗
PubMed2000

High-dose idarubicine, busulphan and melphalan as conditioning for autologous blood stem cell transplantation in multiple myeloma. A feasibility study.

Extensive studies have tested the clinical impact of double and triple sequential transplants as front-line therapy in MM, following the suggestion that dose escalation can overcome the marked drug resistance characteristic of this disease, but the superiority of such approaches vs one single transplant has still to be demonstrated. The aim of our study was to evaluate the feasibility and efficacy of high-dose idarubicine intensification of a standard busulphan-melphalan conditioning regimen in MM. Twenty-eight patients (median age 55 years) with sensitive disease received PBSCT after high-dose idarubicine combined with busulphan and melphalan and followed by s.c. rhG-CSF until PMN recovery. The most severe toxicity was represented by oral mucositis which resolved with hemopoietic reconstitution. Overall response and CR rate were 52% and 40%, respectively. Currently, 36 patients are alive and 19 are progression-free a median of 20 months (12-36) from transplant. The 3-year projected probability of progression-free survival for patients transplanted after first-line treatment is 60%. The combination of Ida/Bu/Melph appears a promising alternative regimen for PBSCT in myeloma, with low transplant-related toxicity and fast hematological recovery. Long-term follow-up and a prospective randomized study, now ongoing, will probably clarify whether an idarubicine-intensified regimen will result in superior outcomes to conventional conditioning and even be comparable to a double consecutive transplant program.

Adult↗
PubMed2000

Isolated granulocytic sarcoma of the skin in an elderly patient: good response to treatment with local radiotherapy and low-dose methotrexate.

Granulocytic sarcoma of the skin is frequently associated with haematological diseases and is rarely isolated. The disease generally develops into acute systemic myeloid leukaemia and is associated with a poor prognosis. We report an elderly patient presenting isolated granulocytic sarcoma of the skin who showed a very good response to treatment with local radiotherapy and low-dose methotrexate.

Aged↗
PubMed2000

Intravenous melphalan and dexamethasone followed by lymphoblastoid alpha interferon in higher risk multiple myeloma patients.

Intermittent courses of melphalan and prednisone is still the standard chemotherapy for the initial treatment of multiple myeloma (MM) in patients who cannot undergo high-dose chemotherapy/radiotherapy with either allogeneic or autologous stem cell transplantation. However, the absorption of the drug from the gastrointestinal tract is highly variable from patient to patient and therefore, different plasma levels of the drug are reached in the blood of individual MM patients. In order to overcome this limitation we decided to use intermediate dose (15-30 mg/m2, day 1) intravenous melphalan in resistant or relapsing MM patients as well as in untreated patients not eligible for a more aggressive protocol. Moreover, considering the good results obtained by other investigators using dexamethasone alone or associated with interferon in the treatment of resistant or relapsing MM patients, dexamethasone (40 mg total dose, day 1) and the lymphoblastoid alpha interferon (3 MU, 3 times a week x 3 weeks, from day 8 to day 26 of each course) were added to intravenous melphalan. Courses were repeated every 5 weeks for a total of 6 cycles. We treated 62 MM patients obtaining a response (defined as reduction > 25% of the initial monoclonal component value associated with disappearance of the clinical symptoms) in 38 out 62 evaluable patients (61%) and stable disease (defined as a decrease of < 25% in the base-line serum monoclonal component level with disappearance of all symptoms present at diagnosis) in 9 (14.5%) more patients. The overall median response duration was 14 months and the overall median survival duration (from the time of inclusion in this protocol) for the 62 patients entered into the study was 34 months. No severe (Grade 3-4 of the WHO) hematological as well as non hematological toxicities were observed. This lack of severe toxicity allowed us to administer the drugs on an outpatient basis. In conclusion, the overall response and the low grade of toxicity in this category of patients are encouraging and suggest that this protocol is both effective and safe treatment for high risk MM patients.

Actuarial Analysis↗
PubMed2000

Thrombopoietin, interleukin-11, and early-acting megakaryocyte growth factors in human myeloid leukemia cells.

In this study we report our data on effects of early-acting megakaryocyte growth factors, particularly the c-mpl ligand also known as thrombopoietin (TPO) and interleukin-11 (IL-11), on cell proliferation and apoptosis (Apo) of primary acute myeloid leukemia (AML) cells. A proliferative response to TPO was noticed in the majority of AML samples (17/19) with an average increase of S-phase cells from 7.8% +/- 1.5 to 14.5% +/- 2.1 (p=0.0006). Resulting cell cycle activation did not always correlate with expression of the c-mpl receptor, although it was coupled, in the majority of samples, by an average decrease of apoptotic cells from 13% +/- 0.7 to 8.8% +/- 1.8 (p=0.05). Clonogenic cell growth (CFU-L) was confirmed in 5/17 of the samples with a mean colony number of 21.4 +/- 9.6 x 10(5) cells plated. Conversely, effects of IL-11 on AML cells demonstrated that cell cycle changes (recruitment from G0 to S phase) were promoted only in a minority of samples (2/14) and there was little, if any, effect on CFU-L growth (mean colony number=17.5 +/- 9.5) or Apo (from 13% +/- 0.7 to 13.3 +/- 1.9). Combination of TPO with IL-11 induced a slight increase of clonogenic cell growth, while the addition of IL-3 or SCF to the c-mpl ligand significantly raised the mean colony numbers up to 119.2 +/- 68.3 and 52.9 +/- 22.1 x 10(5) cells plated, respectively. In summary, TPO shows activity on AML cells by stimulating their proliferation in a significant proportion of cases and generally protecting the majority of AML blast cells from induction of Apo. Conversely, IL-11 exerts little effect on the cell cycle activation and Apo. These data help to understand regulation of myeloid leukemia cell growth and should be considered in the clinical use of early-acting megakaryocyte growth factors in acute leukemia.

Apoptosis↗
PubMed2000

Autologous peripheral blood stem cell transplantation as first line treatment of multiple myeloma: an Italian Multicenter Study.

BACKGROUND AND OBJECTIVE: The outcome of patients with multiple myeloma (MM) has not changed markedly since the introduction of melphalan and prednisone. In recent years several studies have investigated the role of intensive therapy followed by infusion of autologous peripheral blood stem cells (PBSC) together with the administration of hematopoietic growth factors. In this study we evaluated the feasibility and efficacy of a PBSC transplantation program for patients with de novo MM in a multicenter setting. DESIGN AND METHODS: In a non-randomized controlled trial 52 patients with de novo MM from 6 Italian centers underwent a three phase treatment strategy including 3 cycles of VAD-like chemotherapy for initial debulking, followed by high-dose cyclophosphamide (HD-CY) and collection of PBSC, that were transplanted after a conditioning regimen with melphalan plus busulfan. Maintenance treatment was a conventional dose of interferon, given until relapse. Actuarial survival and response duration curves were plotted according to Kaplan and Meier's method; the groups were compared using the log rank test. Response rates were compared by the c(2) test; multivariate analysis was performed according to the stepwise regression model. RESULTS: Overall 39/52 (75%) of patients responded, with a complete remission (CR) rate of 31%. After a median follow-up of 55 months, median duration of event-free survival (EFS) and overall survival (OS) are 21 and 57 months, with 24% and 48% probabilities of being event-free and alive after 6 years, respectively. Among the group of 39 responders, CR was significantly associated with prolonged response and survival (2 deaths and 6 relapses/16 patients) as compared with PR (11 deaths and 15 relapses/23 patients), and remained the only significant variable also in a multivariate analysis. Myelosuppression did not protract beyond one week in transplanted patients; extra-hematologic toxicity was very low. INTERPRETATION AND CONCLUSIONS: This multicenter study confirms the feasibility of an aggressive approach to de novo MM patients. Additional confirmation is given of the increased rate of CR, and the significant prolonged survival observed in complete responders. In this experience the association melphalan plus busulfan was shown to be effective, at least as part of conditioning regimens, in the transplant strategy.

Adult↗
PubMed2000

Dose-intensive melphalan with stem cell support (CM regimen) is effective and well tolerated in elderly myeloma patients.

BACKGROUND AND OBJECTIVE: Multiple myeloma (MM) typically afflicts elderly patients. High-dose therapy has recently been shown to lead to a better outcome than standard treatment, mainly in younger patients. The extent to which older subjects can benefit from intensified approaches without excessive toxicity is examined in this study. DESIGN AND METHODS: Between December 1994 and May 1997, 12 Italian Multiple Myeloma Study Group institutions entered 68 patients at diagnosis (median age 65) into an intensified chemotherapy regimen: cyclophosphamide (CY) 3 g/m(2) plus melphalan 60 mg/m(2) followed by peripheral blood progenitor cells (PBPC) and G-CSF (CM regimen). CY (day 0) and G-CSF were used to mobilize PBPC harvested by a single leukapheresis on day 10. Melphalan was infused on day 11. PBPC were kept unprocessed at 4 degrees C for 48 hours and reinfused on day 12. Three CM regimens were delivered at 6-month intervals. RESULTS: Sufficient PBPC to support the first CM cycle were available (median CD34(+) harvest: 4.9x10(6)/kg), but dropped significantly after the second (median CD34(+) harvest: 2x10(6)/kg) and the third (median CD34(+) harvest: 0.9x10(6)/kg). The median durations of severe neutropenia (absolute neutrophil count < 500 microL) were 3, 4, and 3 days, and those of severe thrombocytopenia (platelets < 25,000/microL) were 2.5, 2, and 1 days, after the first, second and third courses, respectively. The frequency of extramedullary toxicities was low. Treatment-related mortality (TRM) was 3% after the first CM, only. Complete remission (CR) was 14% after the first, 16% after the second and 27% after the third CM. After a median follow-up of 34 months (range 19-49 months), median event-free survival was 35.6 months. INTERPRETATION AND CONCLUSIONS: These results indicate that dose-intensity of melphalan can be increased by reinfusing PBPC with acceptable low toxicity. The combination of CY and melphalan followed by PBPC is an effective chemotherapy for elderly myeloma patients. Repeated melphalan infusion hampered subsequent CD34(+) harvests.

Aged↗
PubMed2000

[The role of biotherapy in multiple myeloma].

Despite considerable progress in recent years in the understanding of the biology of multiple myeloma (MM), this disease remains incurable, although many new therapeutic approaches are under evaluation. The rapid development of recombinant technologies has permitted the production of large amounts of cytokines and growth factors, favoring the use of biotherapies also in this disease. Among these products, the interferons have been the most extensively used in clinical trials, giving the most promising results especially in the setting of minimal residual disease, as maintenance therapy after response to conventional therapies, or to high dose chemotherapies followed by bone marrow (BM) or peripheral blood stem cell (PBSC) transplantation. However, more recently, a large number of cytokines and growth factors have been introduced in the clinical practice. Data of the use of erythropoietin have consistently demonstrated the role of this growth factor in ameliorating the grade of anemia as well as the quality of life of those MM patients whose disease is complicated by the presence of a severe or moderate anemia. Using hematopoietic growth factor in the mobilization of PBSC, the quantity of progenitor cells in the peripheral blood increased and the hematological toxicity of chemotherapy could be reduced. Despite the large amount of experimental data indicating a role for interleukins, as IL-2 and IL-6, in controlling tumor growth, there are only few clinical studies dealing with their use in MM. Results show that they arrest tumor progression rather than aid tumor regression, for this reason it appears that IL-2 and anti IL-6 antibodies should be investigated as maintenance therapy, in MM patients responding to chemotherapy. In the future it will be necessary to clarify for MM patients the role of other cytokines such as IL-1 beta and TNF alpha. A possible strategy to improve the clinical outcome of MM patients is to prevent the regrowth of residual tumor cells by establishing adoptive immunity at the stages of minimal residual disease previous obtained using chemotherapy. To this end a possible strategy is to induce an immune response against residual tumor cells by passive (using monoclonal antibodies) or active (using the idiotype expressed by malignant cells) immunotherapy.

Antibodies, Anti-Idiotypic↗
PubMed1999

Cell cycle regulation and induction of apoptosis by IL-6 variants on the multiple myeloma cell line XG-1.

Interleukin-6 (IL-6) serum levels and the proliferative activity of bone marrow plasma cells have been described as important prognostic factors for survival duration in multiple myeloma (MM) patients. Since growth of neoplastic plasma cells is frequently promoted by IL-6, inhibition of its activity has been considered for the management of MM patients. With a similar rationale, IL-6 variants characterized by wild-type or increased affinity for the ligand-specific IL-6 alpha receptor chain and reduced ability to bind and/or dimerize the gp 130 chain have recently been generated. In the present study, the antiproliferative effects of the variants Sant1, Sant5, and Sant7, characterized by increasing antagonistic activity, were investigated by means of a detailed cell kinetic and apoptotic analysis of the IL-6-dependent MM XG-1 cell line. A significant reduction in the mean percent of XG-1 cells in active S-phase (DNA/bromodeoxyuridine incorporation) from 41% to 28.1% (p=0.04), 25.8% (p=0.04), and 15.3% (p=0.02), respectively, was observed using Sant1, Sant5, and Sant7. These effects were confirmed using the acridine-orange (AO) flow-cytometric technique, which showed a similar reduction of S-phase (34.2% of baseline value) in the presence of Sant1, Sant5, and Sant7, as well as a significant G1b arrest (from 44.5% to 47.6%, 48%, and 64.9%). Furthermore, IL-6 variants were capable of down-regulating the G1 cell cycle regulatory protein cyclin D1 expression. Cell cycle effects were coupled with a significant increase of apoptosis, measured by the AO and the terminal deoxynucleotidyl transferase assays, from 12.9% (control culture with IL-6) to 21.2% (Sant1), 29.1% (Sant5), and 23.5% (Sant7). These results were comparable to those obtained by depriving XG-1 of recombinant IL-6. Our study documents the antiproliferative activity exerted by IL-6 mutants on the XG-1 cell line, thus supporting the investigation of these molecules on primary MM cells.

Apoptosis↗
PubMed1999

Thrombopoietin and interleukin 11 have different modulatory effects on cell cycle and programmed cell death in primary acute myeloid leukemia cells.

The c-mpl ligand, thrombopoietin (TPO), is a physiologic regulator of platelet and megakaryocytic production, acting synergistically on thrombopoiesis with the growth factors interleukin 11 (IL-11), stem cell factor, interleukin 3 (IL-3), interleukin 6 (IL-6), and granulocyte-macrophage colony-stimulating factor. Because some of these growth factors, especially TPO and IL-11, are now being evaluated clinically to reduce chemotherapy-associated thrombocytopenia in cancer patients, we evaluated 25 acute myeloid leukemia (AML) samples to test whether TPO, IL-11, and other early-acting megakaryocyte growth factors can affect leukemic cell proliferation, cell cycle activation, and programmed cell death (PCD) protection. TPO induced proliferation in the majority of AML samples from an overall mean proportion of S-phase cells of 7.8% +/-1.5% to 14.5% +/- 2.1% (p = 0.0006). Concurrent G0 cell depletion was found in 47.3% of AML samples. TPO-supported leukemic cell precursor (CFU-L) proliferation was reported in 5 of 17 (29.4%) of the samples with a mean colony number of 21.4 +/- 9.6 x 10(5) cells plated. In 13 of 19 samples, a significant protection from PCD (from an overall mean value of 13% +/-0.7% to 8.8% +/- 1.8%;p = 0.05) was detected after TPO exposure. Conversely, IL-11-induced cell cycle changes (recruitment from G0 to S phase) were detected in only 2 of 14 samples (14.2%). In addition, IL-11 showed little, if any, effect on CFU-L growth (mean colony number = 17.5 9.5) or apoptosis. Combination of TPO with IL-11 resulted in only a slight increase in the number of CFU-L, whereas IL-3 and stem cell factor significantly raised the mean colony numbers up to 119.2 +/- 68.3 and 52.9 +/- 22.1 x 10(5) cells plated, respectively. We conclude that TPO induces cell cycle activation in a significant proportion of cases and generally protects the majority of AML blast cells from PCD. On the other hand, IL-11 has little effect on the cell cycle or PCD. Combination of both TPO and IL-11 is rarely synergistic in stimulating AML clonogenic growth. These findings may be useful for designing clinical studies aimed at reducing chemotherapy-associated thrombocytopenia in AML patients.

Acute Disease↗
PubMed1997

Cycling status of CD34+ cells mobilized into peripheral blood of healthy donors by recombinant human granulocyte colony-stimulating factor.

In this study, we assessed the functional and kinetic characteristics of highly purified hematopoietic CD34+ cells from the apheresis products of 16 normal donors undergoing glycosylated granulocyte colony-stimulating factor (G-CSF) treatment for peripheral blood stem cells (PBSC) mobilization and transplantation in allogeneic recipients. Mobilized CD34+ cells were evaluated for their colony-forming capacity and trilineage proliferative response to selected recombinant human (rh) CSF in vitro and the content of very primitive long-term culture initiating cells (LTC-IC). In addition, the cycling status of circulating CD34+ cells, including committed clonogenic progenitor cells and the more immature LTC-IC, was determined by the cytosine arabinoside (Ara-C) suicide test and the acridine orange flow cytometric technique. By comparison, bone marrow (BM) CD34+ cells from the same individuals were studied under steady-state conditions and during G-CSF administration. Clonogenic assays in methylcellulose showed the same frequency of colony-forming unit cells (CFU-C) when PB-primed CD34+ cells and BM cells were stimulated with phytohemagglutinin-lymphocyte-conditioned medium (PHA-LCM). However, mobilized CD34+ cells were significantly more responsive than their steady-state BM counterparts to interleukin-3 (IL-3) and stem cell factor (SCF) combined with G-CSF or IL-3 in presence of erythropoietin (Epo). In cultures added with SCF, IL-3, and Epo, we found a mean increase of 1.5- +/- 1-fold (standard error of the mean [SEM]) of PB CFU-granulocyte-macrophage and erythroid progenitors (burst-forming units-erythroid) as compared with BM CD34+ cells (P < .05). Conversely, circulating and BM megakaryocyte precursors (CFU-megakaryocyte) showed the same clonogenic efficiency in response to IL-3, granulocyte-macrophage-CSF and IL-3, IL-6, and Epo. After 5 weeks of liquid culture supported by the engineered murine stromal cell line M2-10B4 to produce G-CSF and IL-3, we reported 48.2 +/- 35 (SEM) and 62.5 +/- 54 (SEM) LTC-IC per 10(4) CD34+ cells in PB and steady-state BM, respectively (P = not significant). The Ara-C suicide assay showed that 4% +/- 5% (standard deviation [SD]) of committed precursors and 1% +/- 3% (SEM) of LTC-IC in PB are in S-phase as compared with 25.5% +/- 12% (SD) and 21% +/- 8% (SEM) of baseline BM, respectively (P < .001). However, longer incubation with Ara-C (16 to 18 hours), in the presence of SCF, IL-3 and G-CSF, or IL-6, showed that more than 60% of LTC-IC are actually cycling, with no difference being found with BM cells. Furthermore, studies of cell-cycle distribution on PB and BM CD34+ cells confirmed the low number of circulating progenitor cells in S- and G2M-phase, whereas simultaneous DNA/RNA analysis showed that the majority of PB CD34+ cells are not quiescent (ie, in G0-phase), being in G1-phase with a significant difference with baseline and G-CSF-treated BM (80% +/- 5% [SEM] v 61.9% +/- 6% [SEM] and 48% +/- 4% [SEM], respectively; P < .05). Moreover, G-CSF administration prevented apoptosis in a small but significant proportion of mobilized CD34+ cells. Thus, our results indicate that mobilized and BM CD34+ cells can be considered equivalent for the frequency of both committed and more immature hematopoietic progenitor cells, although they show different kinetic and functional profiles. In contrast with previous reports, we found that PB CD34+ cells, including very primitive LTC-IC, are cycling and ready to progress into S-phase under CSF stimulation. This finding should be taken into account for a better understanding of PBSC transplantation.

Adolescent↗
PubMed1997

[Therapy of multiple myeloma].

The association of melphalan and prednisone, introduced in the sixties, allowed a dramatic improvement in the prognosis of multiple myeloma. The subsequent evaluation of different polychemotherapeutic schedules did not ameliorate the results with respect to the melphalan-prednisone association, which remains the treatment of choice in patients older than 60-65 years. In younger patients high dose therapy allowed, in the recent years, significant improvement in terms of reduction of tumor mass and survival. The use of interferon as maintenance treatment allowed a prolongation of the response phase obtained after induction treatment. In this paper we discuss current trends in the management of multiple myeloma and related complication.

Adult↗