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Biomedical subjects

G Papa

Publications and source records attributed to G Papa.

207 records · Page 12Linked to original sources
PubMedDate not supplied

Sequential combination of methotrexate and L-asparaginase in the treatment of refractory acute leukemia.

Seventy-six patients with advanced acute leukemia refractory to conventional chemotherapy were treated with a sequential combination of methotrexate (MTX) and L-asparaginase (L-ASP), based on the reported schedule-dependent synergism between the two drugs in human leukemic cells in vitro. On Day 1, patients received 60 mg/m2 of MTX iv, followed 24 hours later by L-ASP at a dose of 10,000 IU/m2 iv. This sequence was repeated weekly with 50% escalations in the dose of MTX with each course. Overall, 31 of 76 patients (40.7%) achieved complete remission after a median of three courses; the response rate was 35.5% in patients with acute nonlymphocytic leukemia (21 of 59 patients) and 58.8% in patients with acute lymphocytic leukemia (ten of 17). Increasing the starting dose of MTX to 200 mg/m2 did not improve the response rate. Maintenance therapy with the same combination given every 2 weeks produced a median complete remission of 10 weeks. Toxicity was manifested by: acute hypersensitivity reactions to L-ASP (five patients), stomatitis (36 patients), and mild liver abnormalities (five patients). MTX in doses up to 200 mg/m2 caused minimal myelosuppression. We conclude that the MTX-L-ASP combination is a well-tolerated, highly effective induction regimen for refractory acute leukemia.

Acute Disease↗
PubMedDate not supplied

Triple immunofluorescence evaluation of CD15, CD34 and class II expression by flow cytometry in normal and leukemic bone marrows.

BACKGROUND: The CD15/CD34 phenotype has been reported as aberrant and exploited for monitoring minimal residual disease in acute myeloid leukemia (AML) patients. Moreover, CD15/CD34 has been described as a rare phenotype in normal bone marrow (NBM) (< 0.10%). We used a triple immunofluorescence assay to investigate the expression of CD15, CD34 and class II antigens in normal (NMB) and leukemic (LBM) bone marrows. METHODS: A FACScan for quantitative fluorescence and the PAINT-A-GATE program for multiparametric analysis were utilized. Fifteen normal bone marrow and fifteen leukemic bone marrow samples were studied with a triple immunofluorescence assay. A FACSorter was used for sorting. RESULTS: Eleven out of 15 normal marrows contained less than 0.67% (range 0.01-0.66) cells which coexpressed CD15, CD34 and class II antigens. Three normal marrows contained more than 0.67% but less than 1.84% (range 1.05-1.83) triple stained cells. The entire group of leukemic marrows coexpressed triple stained cells with a frequency higher than 1% (range 1.1-48.6); furthermore, 10 samples contained the same population at frequencies higher than 10%. The difference between normal and leukemic marrows was statistically significant (p = < 0.001). Triple positive cells (TPc) from NBM were sorted for morphology, which proved to be consistent with myeloid progenitor features (early myeloblasts). This confirms that CD15+ CD34+ Class II+ precursors are commonly expressed in NMB, although at low frequency. Interestingly, 12 (80%) AMLs out of 15 were diagnosed as M1 (5) or M2 (7), while the remaining were M4 (2) and M5a (1). Additionally, all M2 cases were positive at percentages higher than 10%. Apparently CD15, CD34, class II expression correlates mainly with granulocyte differentiation. Two complete remission (CR) LBM, positive at onset for the triple combination, were regularly monitored. In one case the TPc percentage always remained near the normal values found in NBM (0.72%), and this patient is still in CR. In the other, overt relapse was preceded by a progressive increase in the TPc percentage. CONCLUSIONS: Although the presence in NBM of CD15+ CD34+ and class II+ precursors hinders minimal residual disease detection, we conclude that this unusual combination may distinguish a leukemic population and may allow monitoring of "early relapse".

Acute Disease↗
PubMedDate not supplied

Beta-thalassemia mutations in Rome. A high frequency of the IVSII-745 allele in subjects of latium origin.

We studied the molecular bases of beta-thalassemia in Rome, a city centrally located in Latium, which is a region with a low incidence of beta-carriers. People also come to Rome from other regions for specific or prenatal diagnostic assessment. Only 11 patients (20%) out of 62 characterized beta-thalassemia subjects were of Latium family origin. They presented five mutations with an uncommonly high frequency of the IVSII-745 allele, that was found in homozygosis in 4 unrelated patients from a southeastern area in the province of Frosinone. These data may indicate a founder effect.

Alleles↗