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M G Michieli

Publications and source records attributed to M G Michieli.

6 recordsLinked to original sources
PubMed1995

MDR-related P170-glycoprotein modulates cytotoxic activity of homoharringtonine.

Homoharringtonine (HHT) is a new drug with antileukemic activity which is currently tested for treatment of acute and chronic leukemias, either alone or in combination with other agents. Since HHT showed a low efficacy in refractory and relapsed acute leukemia and in the blastic phase of chronic myeloid leukemia (CML) which are frequently characterized by an overexpresion of the multidrug resistance (MDR)-related P170-glycoprotein, we postulated a relationship between the poor antileukemic effect of HHT in these leukemias and the expression of P170-glycoprotein. For this reason, sensitive (LOVO109 and CEM) and MDR (LOVO DX and CEM VLB) cell lines were exposed to HHT with or without some MDR modifiers, namely, Cyclosporine A (CyA), the Cyclosporine derivative SDZ PSC 833 (PSC), and the D-isomer of Verapamil (DVRP). It was found that MDR cells were about 15 times more resistant to HHT than non-MDR cells, and that resistance to HHT was significantly decreased by all the MDR modifiers that were tested. This in vitro study showed that HHT belongs to the category of MDR-related drugs, like anthracyclines, vinca alkaloids, epipodophylline derivatives, and taxol.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1991

Immunohistochemical detection of the multidrug transport protein P170 in human normal tissues and malignant lymphomas.

Two monoclonal antibodies, MRK16 and C219, both directed at the 170 kDa P-glycoprotein multidrug resistance agent, were applied to frozen sections or cytospin preparations from normal human tissues and 60 non-Hodgkin's malignant lymphomas. Adrenal gland, kidney, liver and pancreas were always stained by the reagents, albeit with slightly different patterns. Brain capillaries as well as macrophages and some elements of the bone marrow, peripheral blood, ovarian stroma and colonic, gastric and jejunal mucosa were positive in all examined preparations. There were differences in the staining patterns with the two antibodies. Among the 60 non-Hodgkin's lymphomas, 25 contained a number of positive cells, which ranged from 2% to 100%. No correlation was seen between the expression of P170 and histological type, stage, clinical symptoms or growth fraction. A close relationship was shown between the presence of P170 positive elements and the clinical course of the disease (P less than 0.001).

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1988

Treatment of hairy-cell leukaemia with alpha-interferon (alpha-IFN).

Twenty-three patients with hairy-cell leukaemia (HCL), six of whom were previously splenectomized, were treated with alpha-interferon (alpha-IFN) 3 MU per day for 3-6 months and then with 3 MU three times per week for at least 3 further months. Seven patients (two splenectomized) showed a complete response (CR), 11 patients achieved a partial response (PR) and the remaining five experienced only a minor response (MR). All seven patients who achieved a CR are still in CR after 10-21 months from the onset of the disease. Among the 11 PRs, five showed an increase in the number of circulating hairy cells during the follow-up; they were re-started on alpha-IFN and an improvement of the haematological values was again obtained. One patient who achieved only a MR died after 1 month therapy because of severe infection. Following treatment with alpha-IFN, the improvement or normalization of the peripheral blood counts was paralleled by an improvement of the immunologic surface markers, as determined by monoclonal antibodies, and by an improvement of the response to PHA and of the natural killer activity. These findings, coupled to the mild drug-related toxicity observed, confirm that treatment with alpha-IFN represents a safe and effective therapeutic approach for both splenectomized and non-splenectomized HCL patients.

Adult↗
PubMedDate not supplied

Serum lactate dehydrogenase is an important risk determinant in acute lymphocytic leukemia.

Pretreatment serum total lactate dehydrogenase (LDH) activity was measured in 341 adult patients (greater than 15 years old) with acute lymphocytic leukemia (ALL) in order to assess its prognostic value. Failure, death during induction and remission were not related to LDH. In contrast, a negative and continuous relationship was found between LDH and relapse-free survival. Though LDH activity was significantly higher in cases with already established risk factors such as high WBC count, FAB L3 cytotype, mature B-cell phenotype, and central nervous system involvement, LDH was confirmed to be the strongest predictor of remission duration by multivariate analysis. This study provides a definitive confirmation of the negative prognostic value of LDH in adult ALL.

Adolescent↗