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Biomedical subjects

Giuseppe Leone

Publications and source records attributed to Giuseppe Leone.

At least 55 records · Page 3Linked to original sources
PubMed2004

Clinical isolation and functional characterization of cord blood CD133+ hematopoietic progenitor cells.

BACKGROUND: Human cord blood is a relevant source of CD133+ HPCs. Clinical-scale isolation of human umbilical cord blood (UCB) CD133+ HPCs using immunomagnetic microbeads and the CliniMACS clinical cell isolator is reported. CD133+ HPCs isolated after large-scale processing were functionally characterized. STUDY DESIGN AND METHODS: Closed disposable sets were used to process nine different samples of RBC-reduced UCB nucleated cells. In-vitro hematopoietic assays and human xenografts in NOD/SCID mice were performed to assess the functional properties of isolated CD133+ cells. Different mixtures of human cytokines were tested for the ability to expand nascent CD133+ HPCs. Furthermore, freshly isolated CD133+ cells were conditioned in culture medium specifically tested to support in-vitro myogenesis or osteogenesis. RESULTS: Isolation procedures yielded the recovery of an average of 2.53 x 10(6) CD133+ HPCs with a mean recovery of 96 percent (referred to as RBC-reduced samples) and a final sample purity of 82 percent. Purified CD133+ cells had high cloning efficiency, had relevant long-term activity, and were capable of repopulating irradiated NOD/SCID mice. In 10-day stroma-free cultures, a 2-fold and 8.3-fold expansion of colony-forming cells (CFCs) and extended long-term culture-initiating cells, respectively, was obtained. Freshly isolated CD133+ cells differentiated into large nucleated cells expressing either myosin D or osteopontin (as revealed by RT-PCR and immuno-cytochemistry), with a protein/mRNA expression comparable to or even higher than that observed in UCB CD133- nucleated cells in identical culture conditions. CONCLUSION: Collectively, clinical-scale isolation of UCB CD133+ cells provides a relevant amount of primitive HPCs with high hematopoietic activity and in-vitro mesenchymal potential.

AC133 Antigen↗
PubMed2004

Novel antithrombotic agents: indirect synthetic inhibitors of factor Xa and direct thrombin inhibitors. Evidences from clinical studies.

The optimal drugs employed in the antithrombotic treatment and prophylaxis have ideally been suggested to have high efficacy and safety and to be easy to use as regards the administration route and the fashion of monitoring the anticoagulant effect. A number of agents are under development in order to improve such requirements. Among them, the present review is focussed on a selective factor Xa inhibitor (pentasaccharide fondaparinux) and the direct thrombin inhibitors now available on a clinical ground. Fondaparinux is the first of a new class of selective antithrombin-dependent factor Xa inhibitors; it does not interact with plasma proteins other than antithrombin, leading to a predictable pharmacokinetics, which renders monitoring and dose adjustment unnecessary. The efficacy and safety of fondaparinux has been assessed in a number of clinical trials. In patients undergoing major orthopaedic surgery, a 2.5 mg s.c administration once daily induced a 50% average relative risk reduction for overall venous thromboembolism in comparison with enoxaparin but also an increased rate of major bleeding. Parenteral direct thrombin inhibitors include hirudin, bivalirudin and argatroban. these inhibitors have been studied in patients with coronary heart disease. In particular, in patients undergoing percutaneous coronary interventions, bivalirudin showed equivalent or higher efficacy but lower bleeding in comparison with unfractionated heparin. Another series of molecules capable of inhibiting thrombin is derived from the site of fibrinogen to which thrombin binds. Inogatran and melagatran have a low bioavailability when given orally, whereas the chemically modified prodrug ximelagatran has a higher bioavailability. Ximelagatran is safe and effective at least as low molecular weight heparin in patients undergoing major orthopaedic surgery and is safe and effective also in prevention of recurrence in patients with venous thromboembolism or myocardial infarction; ximelagatran is more effective than oral anticoagulants in prevention of arterial embolism due to atrial fibrillation, with comparable safety.

Clinical Trials as Topic↗
PubMed2004

Methylenetetrahydrofolate reductase genotypes do not play a role in acute lymphoblastic leukemia pathogenesis in the Italian population.

BACKGROUND AND OBJECTIVES: Methylenetetrahydrofolate reductase (MTHFR) is one of the enzymes involved in folate metabolism and DNA methylation and synthesis. Some genotypes of this highly polymorphic enzyme are associated with decreased activity. Previous studies have suggested that individuals with the MTHFR 677TT, 1298AC and 1298CC have a lower risk of adult acute lymphoblastic leukemia (ALL). DESIGN AND METHODS: In order to test this association we studied the presence of the C677T and A1298C mutant alleles in 174 patients with acute lymphoblastic leukemia and in 110 controls from central Italy. RESULTS: We did not find any association between the different polymorphisms and susceptibility to ALL. In multivariate analysis different genotypes did not show any correlation with the risk of ALL. The adjusted odds ratios and 95% confidence intervals for MTHFR C677T were 0.69 (0.4-1.19) for 677CT versus 677CC wild type, and 0.99 (0.50-1.97) for 677TT versus 677CC. The corresponding values for MTHFR A1298C were 0.93 (0.56-1.53) for 1298AC versus 1298AA wild type and 1.14 (0.36-3.61) for 1298CC versus 1298AA. INTERPRETATION AND CONCLUSIONS: These results do not support the suggestion that populations carrying different genotypes of the two MTHFR polymorphisms, C677T and A1298C, have a different susceptibility to ALL, at least in the Mediterranean area.

Alleles↗
PubMed2004

In vivo priming with granulocyte colony-stimulating factor possibly enhances the effect of gemtuzumab-ozogamicin in acute myeloid leukemia: results of a pilot study.

Eight elderly patients with relapsed or refractory acute myeloid leukemia were treated sequentially with recombinant human granulocyte colony-stimulating factor with rhG-CSF and Mylotarg. Priming with rhG-CSF in vivo induced an increase in the proportion of CD33+ cycling blasts. Four patients (50% ) achieved a complete remission, 2 patients had a partial remission and the other 2 were resistant.

Aged↗
PubMed2004

Polymorphisms of CYP1A1 and glutathione S-transferase and susceptibility to adult acute myeloid leukemia.

BACKGROUND AND OBJECTIVES: The origin of acute myeloid leukemia (AML) may be explained by a combination of genetic susceptibility factors and environmental exposure. We studied the polymorphisms of cytochrome P450 CYP1A1 and glutathione S-transferase (GST), enzymes involved in the metabolism of carcinogens and anti-cancer drugs, as risk factors for adult AML. DESIGN AND METHODS: The prevalence of CYP1A1*2A, *2B and *4 alleles and of GSTM1 and GSTT1 homozygous deletions was examined in 193 patients with AML and 273 normal individuals using polymerase chain reaction (PCR)-based methods. RESULTS: A higher prevalence of the CYP1A1*4 allele was found in AML patients than in controls (19.1% vs 9.9%, OR =2.2, 95% C.I. 1.3-3.7, p=0.006). GSTT1 homozygous deletions were also more frequent in AML patients (29% vs 19%, OR = 1.7, 95% CI 1.1-2.7, p=0.02). The combination of GSTT1 null genotype and CYP1A1 *2B and *4 alleles further increased the risk of AML (OR =10.2, 95% CI 1.2-83.9, p=0.01, and OR =7.0, 95% CI 2.0-24.8, p=0.001, respectively). INTERPRETATION AND CONCLUSIONS: Polymorphic variants in xenobiotic-metabolism genes, including CYP1A1 and GSTT1, may increase the risk of adult AML, particularly when present together.

Acute Disease↗
PubMed2004

Efficacy of a modified Stanford V regimen in patients with advanced Hodgkin's lymphoma.

We report treatment results obtained with a modified Stanford V regimen in 32 patients with advanced Hodgkin's lymphoma (stage II bulky disease, III, IV). Treatment results were not superior to those achieved with conventional treatment (ABVD) in terms of complete remission and survival rates (progression-free survival and overall survival at 3 years: 66% and 91%, respectively).

Adolescent↗
PubMed2004

Sequential administration of gemtuzumab ozogamicin and conventional chemotherapy as first line therapy in elderly patients with acute myeloid leukemia: a phase II study (AML-15) of the EORTC and GIMEMA leukemia groups.

BACKGROUND AND OBJECTIVES: Acute myeloid leukemia (AML) in the elderly is associated with low rates of response to conventional chemotherapy and long-term survival, highlighting the need for innovative treatment strategies. Gemtuzumab ozogamicin (GO) is an immunoconjugate that has shown activity in relapsed AML with a favorable safety profile. The aim of this collaborative trial was to assess the feasibility, safety, and antileukemic activity of administering GO followed by conventional chemotherapy as first line therapy in patients aged 61-75 years with AML. DESIGN AND METHODS: Eligible patients received frontline treatment with GO 9 mg/m2 infused intravenously on days 1 and 15. Following response assessment to GO, patients were started on conventional chemotherapy consisting of the MICE regimen (mitoxantrone, cytarabine, etoposide). No further treatment was planned for complete responders. RESULTS: Among the 57 evaluable patients, 38 (67%) completed the entire sequential treatment as planned. The overall response rate to the entire induction sequence was 54.4% (31/57), with complete remission (CR) in 35.1% and complete remission with incomplete platelet recovery (CRp) in 19.3%. Rates of failure due to treatment-related mortality or resistant disease were 14.1% (3 toxic deaths during the GO segment, 5 during MICE) and 29.9%, respectively. An initial response to GO was documented in 20 patients (35.1%), with CR in 22.8% and CRp in 12.3%; 6 additional patients entered a partial remission. Reversible myelosuppression and liver toxicity were the main adverse events during both segments of induction. Frontline GO was associated with modest mucosal and gastrointestinal toxicity, but grade 3-4 pancytopenia was universal and prolonged. Hepatic veno-occlusive disease developed in 3 patients after GO and 2 after MICE, resulting in 4 deaths from liver failure. One-year survival at follow-up was 34%. Twelve patients continue in CR/CRp after a median of 226 days. INTERPRETATION AND CONCLUSIONS: The sequential combination of GO and conventional chemotherapy is a feasible and active treatment strategy for older patients with untreated AML. This novel regimen is now being compared in a phase III trial (AML-17).

Acute Disease↗
PubMed2004

G20210A prothrombin gene variant and clinical outcome in patients with a first acute coronary syndrome.

BACKGROUND AND OBJECTIVES: The prognostic value of the G20210A prothrombin gene polymorphism in patients with a first acute coronary syndrome has not been previously assessed. We conducted a prospective study to investigate this issue. DESIGN AND METHODS: Genotyping at the 20210 prothrombin gene locus was performed in 162 patients with a first episode of myocardial infarction (MI) or unstable angina (UA) occurring before 65 years of age. Patients were stratified according to cardiovascular risk factors and to treatment strategy. The subsequent two-year relative risk (RR) of adverse events (death, MI and UA) was adjusted for possible confounders and analyzed according to genotype, risk factor category, and treatment allocation. RESULTS: In the entire study population, the prothrombin variant did not significantly increase the two-year risk of events: the adjusted RR for GA vs GG carriers was 1.82 (95% CI 0.68-4.89). However, in the absence of traditional cardiovascular risk factors the risk of events was consistently higher: among the 46 patients without hypertension, diabetes and hypercholesterolemia, GA vs GG carriership was associated with an adjusted RR at two years of 5.64 (95% CI 1.07-29.84). The gene variant also enhanced the risk of events among the 98 patients who did not undergo myocardial revascularization procedures (RR for GA vs GG: 2.89, 95% CI 1.04-8.00), but not among those who did. INTERPRETATION AND CONCLUSIONS: The present prospective study suggests that heterozygosity for the G20210A prothrombin polymorphism adversely affects prognosis after a first acute coronary syndrome in the subgroup of patients without metabolic risk factors and in those not treated by revascularization procedures.

3' Untranslated Regions↗
PubMed2004

Cytomegalovirus reactivation during alemtuzumab therapy for chronic lymphocytic leukemia: incidence and treatment with oral ganciclovir.

BACKGROUND AND OBJECTIVES: Although alemtuzumab (campath-1H) has been successfully used in patients with untreated or previously treated chronic lymphocytic leukemia (CLL), a variable incidence of cytomegalovirus (CMV) reactivation has been described. No prospective reports currently provide results of the use of oral ganciclovir as pre-emptive therapy in patients with CMV reactivation during alemtuzumab treatment. DESIGN AND METHODS: We designed a prospective study in 12 patients with pretreated CLL with the aim of evaluating the incidence of CMV reactivation during alemtuzumab treatment and the role of oral ganciclovir as pre-emptive therapy and in preventing CMV organ disease. RESULTS: In the 12 CLL patients being treated with alemtuzumab, 8 patients (66%) had CMV reactivation, as detected by antigenemia and/or CMV DNA. No patient showed clinical evidence of CMV disease. The alemtuzumab was discontinued and the patients were immediately treated with oral ganciclovir 1000 mg tid. After a median of 14 days of antiviral therapy all patients achieved negative CMV polymerase chain reaction (PCR) assays and/or antigenemia. No patients showed further CMV reactivation up to the end of the study. INTERPRETATION AND CONCLUSIONS: CMV reactivaction, studied with periodic analysis of antigenemia and PCR, is frequent in previously treated CLL patients receiving alemtuzumab therapy although only sporadic cases of CMV disease have been reported. Using oral ganciclovir, the response to therapy was prompt, there was no progression to CMV disease, and no relevant clinical toxicity, thus sparing unnecessary hospitalization. Oral ganciclovir may be used as pre-emptive therapy in all patients who develop CMV reactivation during alemtuzumab treatment.

Administration, Oral↗
PubMed2003

Aberrant methylation of DAP-kinase in therapy-related acute myeloid leukemia and myelodysplastic syndromes.

Death-associated protein kinase (DAP-kinase), a proapoptotic serine/threonine kinase, is a candidate tumor suppressor gene. We studied the methylation status of DAP-kinase of 194 bone marrow samples from 160 patients with acute myeloid leukemia (AML) and 34 with a myelodysplastic syndrome (MDS) at the time of initial diagnosis by polymerase chain reaction (PCR). Hypermethylation of DAP-kinase was present in 27.5% (44 of 160) of AML and in 47% (16 of 34) of MDS specimens and significantly correlated to loss of DAP-kinase expression (P =.008). It was significantly more frequent in AML secondary to therapy for other malignancies (s-AML; 14 of 29, 48.3%), as compared to de novo AML (30 of 131, 22.9%, P =.01). DAP-kinase hypermethylation in AML was associated with myelodysplastic changes in the bone marrow at the time of the initial diagnosis (P =.002) and with the presence of cytogenetic abnormalities (P =.02). Alteration in the apoptotic response due to the loss of DAP-kinase function may be an early event in the transformation pathway to secondary leukemia via myelodysplasia.

Aged↗
PubMed2003

Identification of a novel subpopulation of human cord blood CD34-CD133-CD7-CD45+lineage- cells capable of lymphoid/NK cell differentiation after in vitro exposure to IL-15.

The hemopoietic stem cell (HSC) compartment encompasses cell subsets with heterogeneous proliferative and developmental potential. Numerous CD34(-) cell subsets that might reside at an earlier stage of differentiation than CD34(+) HSCs have been described and characterized within human umbilical cord blood (UCB). We identified a novel subpopulation of CD34(-)CD133(-)CD7(-)CD45(dim)lineage (lin)(-) HSCs contained within human UCB that were endowed with low but measurable extended long-term culture-initiating cell activity. Exposure of CD34(-)CD133(-)CD7(-)CD45(dim)lin(-) HSCs to stem cell factor preserved cell viability and was associated with the following: 1) concordant expression of the stem cell-associated Ags CD34 and CD133, 2) generation of CFU-granulocyte-macrophage, burst-forming unit erythroid, and megakaryocytic aggregates, 3) significant extended long-term culture-initiating cell activity, and 4) up-regulation of mRNA signals for myeloperoxidase. At variance with CD34(+)lin(-) cells, CD34(-)CD133(-)CD7(-)CD45(dim)lin(-) HSCs maintained with IL-15, but not with IL-2 or IL-7, proliferated vigorously and differentiated into a homogeneous population of CD7(+)CD45(bright)CD25(+)CD44(+) lymphoid progenitors with high expression of the T cell-associated transcription factor GATA-3. Although they harbored nonclonally rearranged TCRgamma genes, IL-15-primed CD34(-)CD133(-)CD7(-)CD45(dim)lin(-) HSCs failed to achieve full maturation, as manifested in their CD3(-)TCRalphabeta(-)gammadelta(-) phenotype. Conversely, culture on stromal cells supplemented with IL-15 was associated with the acquisition of phenotypic and functional features of NK cells. Collectively, CD34(-)CD133(-)CD7(-)CD45(dim)lin(-) HSCs from human UCB displayed an exquisite sensitivity to IL-15 and differentiated into lymphoid/NK cells. Whether the transplantation of CD34(-)lin(-) HSCs possessing T/NK cell differentiation potential may impact on immunological reconstitution and control of minimal residual disease after HSC transplantation for autoimmune or malignant diseases remains to be determined.

AC133 Antigen↗
PubMed2003

Association between glutathione S-transferase genotypes and Hodgkin's lymphoma risk and prognosis.

PURPOSE: The interplay between genetic susceptibility and exposure to carcinogens has been shown to be involved in the etiology of many solid tumors. We studied the frequency and clinical correlates of polymorphisms resulting in deletions of two genes involved in the detoxification of potentially carcinogenic agents, glutathione S-transferase (GST)-M1 and GSTT1 in patients with Hodgkin's lymphoma (HL). EXPERIMENTAL DESIGN: The prevalence of gene deletions in 90 patients with HL was compared with a case-matched cohort of 176 normal blood donors. GST gene polymorphisms were studied using a multiplex PCR method, including the BCL2 gene as an internal control. RESULTS: Deletions of the GSTT1 gene were more frequent in cases compared with controls (28.9 versus 17.6%, P = 0.04), resulting in an increased risk for HL in individuals with the GSTT1-null genotype (odds risk, 1.9; 95% confidence interval 1.04-3.46). The GSTT1-null genotype particularly increased the HL risk in females aged <45 years (odds risk 6.1, 95% confidence interval 1.6-23, P = 0.008). Correlating patient characteristics to genotype, we found an association between the GSTT1-null genotype and a limited stage of disease (I/IIA versus IIB-IV, 40.6 versus 19.6%, P = 0.047) and an erythrocyte sedimentation rate of <50 mm/h (P = 0.02). Patients with at least one GST deletion (GSTM1- or GSTT1-) had a significant better disease-free survival when compared with those with undeleted GST genes (GSTM1+/GSTT1+; P = 0.012). CONCLUSIONS: The GSTT1-null genotype may increase the risk for HL and is associated with favorable prognostic factors, and the presence of at least one GST deletion indicates an improved disease-free survival.

Adolescent↗
PubMed2003

A new biotin derivative-DOTA conjugate as a candidate for pretargeted diagnosis and therapy of tumors.

The synthesis of a new biotin derivative, the (CO) reduced N-aminohexyl biotinamido derivative, designed to be serum biotinidase resistant, and its conjugation to the chelator DOTA through an amide bond at one of the four carboxymethyl chains are described. The (90)Y-labeled conjugate was able to bind avidin at different Av/conjugate molar ratios with good results. The preclinical results indicate that this new biotin-DOTA conjugate is a good candidate for pretargeted diagnosis and therapy of tumors.

Antineoplastic Agents↗
PubMed2003

Drug treatment in the development of mismatch repair defective acute leukemia and myelodysplastic syndrome.

DNA from therapy-related acute leukemia/myelodysplastic syndrome cases (tAL/MDS) from the GIMEMA [Gruppo Italiano Malattie Ematologiche Maligne dell'Adulto] Archive was examined for the microsatellite instability (MSI(+)) phenotype that is diagnostic for defective DNA mismatch repair. More than 60% (16/25) of tAL/MDS cases were MSI(+) in contrast to <4% (0/28) of de novo cases. hMLH1 gene silencing was rare and evidence of promoter methylation was found in less than one-third of the MSI(+) cases. Among the GIMEMA patients who had been treated for breast cancer there was an apparent trend towards early onset primary breast disease. This suggests that there might be common predisposing factors for breast cancer and tAL/MDS. There were also three examples of mutations in the MRE11 gene among the 25 tAL/MDS cases suggesting that defective recombinational DNA repair may promote the development of secondary malignancy. MSI(+) tAL/MDS was significantly associated with previous chemotherapy and the frequency of MSI(+) among radiotherapy patients was considerably lower. In view of the established relationship between drug resistance and mismatch repair defects, we suggest that selection for therapeutic drug resistance may contribute to the incidence of MSI(+) tAL/MDS.

Acute Disease↗
PubMed2003

Allogeneic compared with autologous stem cell transplantation in the treatment of patients younger than 46 years with acute myeloid leukemia (AML) in first complete remission (CR1): an intention-to-treat analysis of the EORTC/GIMEMAAML-10 trial.

In the European Organization for Research and Treatment of Cancer Leukemia Group and Gruppo Italiano Malattie Ematologiche dell' Adulto (EORTC-LG/GIMEMA) acute myeloid leukemia (AML)-10 trial, patients in first complete remission (CR1) received a single intensive consolidation (IC) course. Subsequently, those patients younger than 46 years with an HLA-identical sibling donor were assigned to undergo allogeneic (allo) stem cell transplantation (SCT), and patients without such a donor were planned for autologous (auto) SCT. Between November 1993 and December 1999, of 1198 patients aged younger than 46 years, 822 achieved CR. The study group constituted 734 patients who received IC: 293 had a sibling donor and 441 did not. Allo-SCT and auto-SCT were performed in 68.9% and 55.8%, respectively. Cytogenetic determination was successfully performed in 446 patients. Risk groups were good (t(8;21), inv16), intermediate (NN or -Y only), and bad/very bad (all others). Median follow-up was 4 years; 289 patients relapsed, 66 died in CR1, and 293 died. Intention-to-treat analysis revealed that the 4-year disease-free survival (DFS) rate of patients with a donor versus those without a donor was 52.2% versus 42.2%, P =.044; hazard ratio = 0.80, 95% confidence interval (0.64, 0.995), the relapse incidence was 30.4% versus 52.5%, death in CR1 was 17.4% versus 5.3%, and the survival rate was 58.3% versus 50.8% (P =.18). The DFS rates in patients with and without a sibling donor were similar in patients with good/intermediate risk but were 43.4% and 18.4%, respectively, in patients with bad/very bad risk cytogenetics. In younger patients (15-35 years), the difference was more pronounced. The strategy to perform early allo-SCT led to better overall results than auto-SCT, especially for younger patients or those with bad/very bad risk cytogenetics.

Adolescent↗
PubMed2003

Inhibitors of DNA methylation in the treatment of hematological malignancies and MDS.

DNA methylation abnormalities have recently emerged as one of the most frequent molecular changes in hematopoietic neoplasms. Since methylation and transcriptional status are inversely correlated, the hypermethylation of genes involved in cell-cycle control and apoptosis could have a pathogenetic role in the development of cancer. In particular, high-risk myelodysplastic syndromes (MDS) and secondary leukemias show a high prevalence of tumor suppressor gene hypermethylation. The progression of chronic myeloproliferative diseases and of myelodysplastic syndromes, as well as that of lymphoproliferative diseases, is associated with an increased methylation rate, pointing to a role for hypermethylation of critical promoter regions in the transformation to more aggressive phenotypes. In the same line, a significantly worse prognosis has been shown for patients with hypermethylation of several genes compared to that of patients with unmethylated genes. For these reasons, the use of irreversible DNA methyltransferase inhibitors, such as 5-azacytidine and Decitabine, appears to be a promising option for the treatment of MDS and acute myeloid leukemia. In clinical trials, Azacytidine results in a significantly higher response rate, improved quality of life, reduced risk of leukemic transformation, and improved survival compared to supportive care. Similarly, Decitabine showed favorable results, promising response rates, a good nonhematologic toxicity profile, and a trend for better survival compared to intensive chemotherapy, particularly in older patients. The synergistic effect of histone deacetylase inhibitors, including phenylbutyrate (PB), in reactivating silenced genes encouraged clinical studies on the combination of PB and demethylating agents in hematological diseases, characterized by p15 silencing. The sequential administration of a "first generation" demethylating agent and HDAC inhibitors gave preliminary evidence of a reduced methylation of target genes, as also described with Decitabine. Clinical trials are still ongoing, and preliminary data indicate for the first time that the natural history of MDS may be changed by a non-intensive treatment, characterized by an outstanding toxicity profile.

Acetylation↗