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Biomedical subjects

F Dreyfus

Publications and source records attributed to F Dreyfus.

At least 73 records · Page 4Linked to original sources
PubMed1996

Thrombocytemia and abnormal megakaryopoiesis associated with abnormality of chromosome 1p34 in myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are a heterogeneous group of diseases characterized by a cytopenia related to abnormal proliferation and differentiation of marrow precursor cells. Some subtypes of MDS are associated with thrombocytemia or abnormal megakaryopoiesis and certain specific karyotypic abnormalities. We report on four cases of MDS with normal or elevated blood platelet count and a recurring abnormality in chromosome 1p34. The gene involved appears to be different from c-mpl and TPO.

Aged↗
PubMed1996

Drug resistance mechanisms in chronic lymphocytic leukemia.

Peripheral blood samples from 18 patients with chronic lymphocytic leukemias (CLL) who were either untreated but who were later sensitive to chlorambucil (CLL S) or resistant to a combination containing doxorubicin, vincristine, cyclophosphamide and prednisone (CLL R) were studied for glutathione system, P-glycoprotein, PCNA and topoisomerase II expression. P-glycoprotein expression detected by an immunocytochemical technique using MRK 16 antibody was present at the same level in CLL S and CLL R. The percentage of cells positive for P-gp was below 5% in all samples tested. Topoisomerase IIalpha level was quantified by Western blot analysis. None of the 18 CLL samples had detectable topoisomerase IIalpha protein. In addition, 12 CLL were tested for PCNA staining and no samples had more than 1% of positive cells at immunocytochemical detection indicating that CLL cells were not engaged in the cell cycle. Some differences were found between CLL S and CLL R in the glutathione system. Glutathione concentration (GSH) and GST activity was the same in CLL S and CLL R. The glutathione-S-transferase (GST) isoenzyme profile was different in the two CLL groups. The mean GST-pi and GST-alpha quantitation were twice as high as in CLL R compared to CLL S, but this difference did not reach statistical significance because of large variations between CLL samples. A significant correlation was observed between GST-pi expression and GST activity using CDNB as the substrate. GST-mu was detected in only one of seven CLL before therapy and in six of 11 resistant to chemotherapy. No correlation was found between P-glycoprotein expression, GST activity and the different GST isoenzymes studied. These results suggest that the glutathione system could play a role in the resistance of anticancer agents in chronic lymphocytic leukemia. The role of the other drug resistance mechanisms (P-glycoprotein and topoisomerase IIalpha) seems to be of limited importance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

High-dose therapy and autologous blood stem cell transplantation in multiple myeloma: preliminary results of a randomized trial involving 167 patients.

Since 1986, we have treated young patients with aggressive multiple myeloma (MM) by high-dose chemotherapy (HDC) and total body irradiation (TBI) followed with autologous blood stem cell transplantation (ABSCT). To evaluate this strategy: 1) We conducted a phase II trial that included 63 patients. Within a median follow-up of five years after transplantation, overall survival was 60% and median event-free survival was four years, and 2) In the early 1990s, we initiated a prospective trial where, after collection of chemotherapy-mobilized ABSC, patients under 55 years of age with newly diagnosed MM were randomly assigned either to HDC and TBI supported with ABSCT (high-dose therapy [HDT] arm) or to a conventional vincristine, melphalan, cyclophosphamide and prednisone (VMCP) regimen (VMCP arm). In the latter, HDT with ABSCT was performed as a rescue therapy, in case of primary resistance to VMCP or at relapse in responders. As of June 1994, 167 patients have been enrolled since a median time of 26 months. Fourteen (8%) could not be randomized. Among the randomized patients (n = 153), 30 deaths were observed, 13 in the HDT group and 17 in the VMCP group (p = 0.28, two-sided log rank test). Overall survival rates at two years were estimated at 78% for all 167 patients, at 82% in the HDT group and at 67% in the VMCP group. ABSC, provided they are collected early in the disease course, allow a great majority of myeloma patients to receive HDT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Control theory as a conceptual framework for intensive care monitoring.

Monitoring patients hospitalized in hemato-oncology departments to undergo clinical protocols of therapy is a complex task. The main difficulty arises in the management of the oncology protocol as well as in the management of critical episodes of acute illness which frequently occur due to high toxicity of the used antimitotics. This problem of controlling a patient's condition can be conceptualized within the control theory paradigm as the task of controlling a process whose state changes over time and can deviate unacceptably from a normal range. Upon request of a French clinical department of hemato-oncology, we developed an intelligent patient monitor named SEPIA to assist clinicians in this task. Following the control theory analogy at the level of knowledge bases design, we have modeled the medical knowledge as control information to represent the medical actions, and state information is used as feedback control to characterize the patient's state. After a general presentation of SEPIA, the analogies between control theory actors and SEPIA's components are specified. The article then focuses on state variables representation. The data reduction process, activated as new data are given to the system, is described. A simulated running session is finally presented to illustrate the whole reasoning process.

Algorithms↗
PubMed1995

Primary cutaneous medium and large cell lymphomas other than mycosis fungoides. An immunohistological and follow-up study on 54 cases. French Study Group for Cutaneous Lymphomas.

Primary cutaneous medium and large cell lymphomas (MLCL) other than mycosis fungoides (MF) are rare, and their prognosis and treatment are controversial. The clinical, immunohistological and follow-up data of 54 well-documented cases of primary cutaneous MLCL other than MF, seen in our institutions over a 14-year period, were retrospectively reviewed, in order to determine the prognostic factors related to these lymphomas, and to analyse the results obtained with different treatment regimens. Forty-six patients presented with a solitary tumour or with localized lesions, and eight had disseminated cutaneous lesions. According to the updated Kiel classification, 45 cases (83%) corresponded to B-cell lymphomas: centroblastic lymphomas, 32 cases; centroblastic-centrocytic lymphomas, 11 cases; immunoblastic lymphomas, two cases. Nine cases (17%) were classified as T-cell lymphomas: pleomorphic medium and large cell lymphomas, eight cases; anaplastic large cell lymphoma, one case. Four of eight patients with disseminated skin lesions had a T-cell lymphoma, whereas 41 of 46 patients with a solitary tumour had a B-cell lymphoma. Patients with disseminated skin lesions and elevated serum lactate dehydrogenase (LDH) levels had a poor prognosis. Comparison of patients' overall survival, depending on immunohistological subtype, showed that the median survival of patients with pleomorphic T-cell lymphoma was 2.5 years, whereas it was not reached at 12 years for patients with centroblastic-centrocytic and centroblastic lymphoma. The eight patients with disseminated skin lesions were treated with polychemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Thrombopoietin is not responsible for the thrombocytosis observed in patients with acute myeloid leukemias and the 3q21q26 syndrome.

Patients with acute myeloblastic leukaemia (AML) and chromosomic abnormalities of the 3q21;q26 region have striking dysmegakaryopoiesis and normal or increased platelet counts. Leukaemic cells ectopically express the Evi-1 gene which maps to human chromosome 3q26:q27. Thrombopoietin (TPO) has been cloned recently and shown to be the major hormone stimulating both megakaryocytopoiesis and thrombopoiesis. The TPO gene maps to human chromosome 3q26. For this report we studied four patients with typical 3q21:q26 syndrome. Karyotype analysis showed inv(3)(q21;q26) in three cases and t(3:3)(q21;q26) in one case. Although high levels of Evi-1 transcripts could be detected in mRNA isolated from the bone marrow cells of these patients by Northern blot analysis, no TPO transcripts were detectable by RT-PCR technique on the same mRNA samples. These results demonstrate that TPO gene transcription is not activated in patients with 3q26 chromosomic abnormality, and that abnormal TPO production is not responsible for the observed thrombocytosis.

Acute Disease↗
PubMed1995

Timed sequential chemotherapy for previously treated patients with acute myeloid leukemia: long-term follow-up of the etoposide, mitoxantrone, and cytarabine-86 trial.

PURPOSE: To confirm and extend encouraging preliminary results of timed sequential chemotherapy (TSC) in patients with previously treated acute myelogenous leukemia (AML). PATIENTS AND METHODS: We report the results of the regimen of mitoxantrone on days 1 to 3, etoposide on days 8 to 10, and cytarabine on days 1 to 3 and 8 to 10 (EMA) in 133 patients, with a median follow-up of 40 months. RESULTS: Sixty percent of patients, with a 95% confidence interval (CI) ranging from 51% to 68%, achieved complete remission (CR), including 44% (CI, 32% to 57%) of refractory patients and 76% (CI, 64% to 86%) of late first-relapse patients (P = .0002). Twenty-nine percent of patients did not respond to therapy, and 11% died from toxicity. Median duration of neutropenia and thrombocytopenia was 31 days and 29 days, respectively. Severe nonhematologic toxicity included sepsis in 54% of patients and mucositis in 23%. Postinduction therapy included a second course of EMA in 27 patients, maintenance in 10, autologous bone marrow transplantation (BMT) in 12, and allogeneic BMT in 13. Median survival of patients who did not have transplantation performed is 7 months, with 11% (CI, 4% to 18%) survival at 5 years. Median disease-free survival (DFS) is 8 months with 20% (CI, 8% to 32%) DFS at 5 years. Twenty-eight percent (CI, 15% to 44%) of nontransplanted patients who achieved CR had an inversion of CR duration. Previous refractoriness was the main factor associated with poor prognosis for CR achievement, DFS, and survival. CONCLUSION: These results confirm initial reports on TSC and show that approximately 20% of patients with first relapse after therapy can enjoy prolonged DFS using chemotherapy only.

Acute Disease↗
PubMed1995

c-mpl expression in hematologic disorders.

The c-mpl gene encodes a member of the hematopoietic cytokine receptor superfamily. This gene was discovered through the study of a murine retrovirus which induces an acute myeloproliferative syndrome in mice. MPLV (for myeloproliferative leukemia virus) has transduced a truncated and constitutively activated form of the c-mpl receptor chain. The c-mpl ligand is unknown, but recent data indicate that it could specifically regulate thrombocytopoiesis. This review focuses on the expression of the c-mpl gene in a large series of human hematopoietic pathologies by Northern blot analysis. Barely detectable transcript levels were detected in normal bone marrow (BM) and in BM samples from chronic myeloproliferative disorders, plasmocytoma, Burkitt lymphoma or acute lymphoid leukemia. In contrast, high levels of c-mpl expression were detected in 45% of acute myeloid leukemia (AML). No correlation was found between c-mpl expression and the French-American-British classification subtype of AML. However c-mpl expression correlated with CD34 expression, and unfavorable cytogenetic abnormalities, defining a subgroup of AML with a low rate of complete remission. In myelodysplasia, c-mpl expression was elevated in 44% of chronic myelomonocytic leukemia (CMML), 42% of refractory anemia with excess myeloblasts (RAEB), and RAEB in transformation to acute leukemia (RAEBt), but not in refractory anemia (RA) and RA with ringed sideroblasts (RARS). In CMML, there was no correlation between c-mpl expression and any prognostic factor tested, nor with the course of the disease. The biologic significance of c-mpl expression in RAEB and RAEBt is probably different.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Polymyositis associated with Ki-1 lymphoma.

We report here a case of acute polymyositis associated with a Ki-1 non-Hodgkin's lymphoma (NHL). This anaplastic large cell malignant lymphoma was a primary T-cell NHL lymphoma of the bone marrow. The malignant cells expressed the CD30 (Ki-1), CD3, and CD4 antigens, the beta chain of the interleukin 2 receptor (CD25), and the betaF1 antigen (alpha/beta T-cell receptor). Chemotherapy and high dose methylprednisolone pulse therapy were initiated. However, no clinical improvement was noticed, because the patient rapidly died of an acute respiratory distress syndrome. To our best knowledge, this represents the first case of Ki-1 lymphoma associated with Polymyositis.

Acute Disease↗
PubMed1995

Prognostic value of c-mpl expression in myelodysplastic syndromes.

The c-mpl proto-oncogene which encodes a member of the hematopoietic cytokine receptor superfamily has been recently shown to be the receptor for thrombopoietin (TPO), which stimulates megakaryocyte progenitor expansion and differentiation. We studied c-mpl expression by Northern blot analysis, in a large series of 58 MDS. No expression was found in 14 patients with refractory anemia (RA) or with refractory anemia with ring sideroblasts (RARS). In contrast 11/26 (42%) patients with refractory anemia with excess of blasts (RAEB), or with RAEB in transformation (RAEBt), and 8/18 (44%) patients with chronic myelomonocytic leukemia (CMML) expressed c-mpl. In CMML patients, no correlation was found between c-mpl expression and any prognostic factor tested, nor with the course of the disease. In contrast, in RAEB and RAEBt, expression of c-mpl was correlated with high Bournemouth scoring (P < 0.005) and poor survival (P = 0.02) due to leukemic transformation. Forty-five per cent (5/11) of the c-mpl positive patients evolved towards AML with a mean follow-up of 10.5 months, while 13% (2/15) of the c-mpl negative patients developed a secondary leukemia, with a mean follow-up of 21.1 months. Moreover, in RAEB and RAEBt, a significant correlation was observed between c-mpl, CD34, megakaryocyte glycoprotein IIb (GPIIb) expression, and the presence of dysmegakaryopoiesis. These results indicate that patients with RAEB and RAEBt, with high expression of the c-mpl, CD34, and GPIIb genes, may identify a subgroup of patients with particularly poor prognosis, due to an increased risk of secondary leukemia. More aggressive therapy could be justified in these patients.

Antigens, CD↗
PubMed1995

CDR3 size analysis of T cell receptor V beta transcripts: follow-up study in a patient with T cell acute lymphoblastic leukemia.

T cell acute lymphoblastic leukemia (T-ALL) is generally considered to be a clonal disorder arising as an expansion of committed lymphoid precursors. The generation of functional T cell receptor (TCR) genes involves DNA rearrangement processes. This predisposes immature lymphoid cells to abnormal rearrangements. Previous analysis of the TCR genes strongly suggested the clonal origin of human T-ALL. We present a sensitive clonal analysis of bone marrow TCR V beta transcripts in a case of T-ALL. This study allows the analysis not only of TCR V beta transcripts in tumor cells but also the temporal modification of the global TCR repertoire in the follow-up of clinical specimens from bone marrow aspirates. Moreover, we used clone-specific junctional region oligonucleotide probes corresponding to the clonal leukemic population for the molecular monitoring of the malignant clone throughout the clinical course of the disease. This molecular fingerprint appears to be a sensitive method to detect minimal residual disease. It shows that junctional regions of rearranged TCR beta genes corresponding to the tumor cells can also be detected at the time of the complete remission.

Adult↗
PubMed1995

Fluorescence in situ hybridization analysis of minute marker chromosomes in leukemia with monosomy 7.

Monosomy 7 was detected in bone marrow cells from three patients, one with myeloid leukemia, and two others with myelodysplastic syndrome following previous chemotherapy. Fluorescence in situ hybridization (FISH), carried out with an alphoid DNA probe specific for chromosome 7 centromere, showed that a small marker chromosome present in the tumor cells' karyotype of the three patients, was derived from the missing chromosome 7. In two cases, the marker was a ring chromosome, whereas in the third case it was a tiny dot-like chromosome, unnoticed at first examination on R-banded metaphases. In the three cases, the marker was lost in a proportion of tumor cells. FISH experiments suggested that the marker centromere had undergone structural alterations, with a fluorescence pattern distinct from a normal one. On the whole, these data suggest that: firstly, leukemia-associated monosomy 7 results, in a proportion of cases, from a structural event rather than from simple loss of a whole chromosome 7; secondly, interpretation of interphase FISH must be cautious in monosomy 7 evaluation; and thirdly structural alteration of the chromosome 7 derivative alphoid DNA could explain its propensity to segregate unequally and to be lost at mitosis.

Adult↗
PubMed1995

Detection of malignant B cells in peripheral blood stem cell collections after chemotherapy in patients with multiple myeloma.

Autologous transplantation after high-dose chemo or radiotherapy is now frequently used for the treatment of patients with multiple myeloma (MM). The collection of peripheral blood stem cells (PBSC) has a theoretical advantage over autologous bone marrow collection as the malignant plasmacytic contamination is believed to be lower. However, the extent of B cell contamination in PBSC has not been extensively investigated. Using an immunoglobulin heavy chain gene 'fingerprinting' technique at diagnosis and during apheresis after one cycle of chemotherapy we detected a monoclonal population in 44% of PBSC samples (9 positives in 22 studied). There was no correlation between contamination and sex, age, Durie and Salmon classification, C-reactive protein and albumin. A significant correlation was observed with beta 2 microglobulin serum level (P = 0.02). Twenty one patients were grafted and up to the present, with a mean follow-up of 12 months, 6 patients have relapsed including 4 patients with contaminating B cells. Our results suggest that PBSC contamination, defines a 'poor risk' group of patients, with poor prognosis. However, we could not exclude reinitiation of the disease by plasmacyte stem cells after grafting.

Adult↗
PubMed1995

Expression of the Evi-1 gene in myelodysplastic syndromes.

Increased expression of the proto-oncogene Evi-1 has been shown to block the in vitro granulocytic differentiation of myeloid cells in response to granulocytic colony-stimulating factor and to interfere with the proliferation of erythroid cells in response to erythropoietin. We determined the frequency of Evi-1 expression in myelodysplastic syndromes (MDS), a disorder with altered proliferation and differentiation in the erythroid and myeloid lineages. Twenty-one patients were studied. Abnormal expression was found in 1/9 patients with refractory anemia and in 7/12 patients with refractory anemia with excess of blasts (RAEB) or in transformation (RAEBt). No correlation could be found between expression of Evi-1 and age, sex, hemoglobin level and percentage of bone marrow blasts or erythroblasts. This result suggests that the high incidence of Evi-1 expression which remains at low levels in RAEB and RAEBt is not a major determinant of ineffective erythropoiesis and myelopoiesis in MDS.

Base Sequence↗