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P Mineur

Publications and source records attributed to P Mineur.

At least 19 recordsLinked to original sources
PubMed2005

RGDS and DGEA-induced [Ca2+]i signalling in human dermal fibroblasts.

A pulse of short peptides, RGDS and DGEA in the millimolar range, immediately elicits in normal human fibroblasts a transient increase of intracellular Ca2+ ([Ca2+]i). In the present study, we show that this [Ca2+]i occurs in an increasing number of cells as a function of peptides concentration. It is specific of each peptide and inhibited at saturating concentration of the peptide in the culture medium. The [Ca2+]i transient depends on signalling pathways slightly different for DGEA and RGDS involving tyrosine kinase(s) and phosphatase(s), phospholipase C, production of inositol-trisphosphate and release of Ca2+ from the cellular stores. GFOGER, the classical collagen binding peptide of alpha1- alpha2- and alpha11-beta1 integrins, in triple helical or denatured form, does not produce any Ca2+ signal. The [Ca2+]i signalling induced by RGDS and DGEA is inhibited by antibodies against beta1 integrin subunit while that mediated by RGDS is also inhibited by antibodies against the alpha3 integrin. Delay in the acquisition of responsiveness is observed during cell adhesion and spreading on a coat of fibronectin for RGDS or collagen for DGEA or on a coat of the specific integrin-inhibiting antibodies but not by seeding cells on GFOGER or laminin-5. This delay is suppressed specifically by collagenase acting on the collagen coat or trypsin on the fibronectin coat. Our results suggest that free integrins and associated focal complexes generate a Ca2+ signal upon recognition of DGEA and RGDS by different cellular pathways.

Calcium↗
PubMed2005

Translocation t(1;6)(p35.3;p25.2): a new recurrent aberration in "unmutated" B-CLL.

Although reciprocal chromosomal translocations are not typical for B-cell chronic lymphocytic leukemia (B-CLL), we identified the novel t(1;6)(p35.3;p25.2) in eight patients with this disorder. Interestingly, all cases showed lack of somatically mutated IgV(H). Clinical, morphological, immunologic, and genetic features of these patients are described. Briefly, the age ranged from 33 to 81 years (median: 62.5 years) and the sex ratio was 6M:2F. Most of the patients (6/8) presented with advanced clinical stage. Therapy was required in seven cases. After a median follow-up of 28 months, five patients are alive and three died from disease evolution. Three cases developed transformation into diffuse large B-cell lymphoma. Translocation t(1;6) was found as the primary karyotypic abnormality in three patients. Additional chromosomal aberrations included changes frequently found in unmutated B-CLL, that is, del(11)(q), trisomy 12 and 17p aberrations. Fluorescence in situ hybridization analysis performed in seven cases allowed us to map the t(1;6) breakpoints to the 1p35.3 and 6p25.2 chromosomal bands, respectively. The latter breakpoint was located in the genomic region coding for MUM1/IRF4, one of the key regulators of lymphocyte development and proliferation, suggesting involvement of this gene in the t(1;6). Molecular characterization of the t(1;6)(p35.3;p25.2), exclusively found in unmutated subtype of B-CLL, is in progress.

Chromosomes, Human, Pair 1↗
PubMed2002

Antibody-targeted chemotherapy of older patients with acute myeloid leukemia in first relapse using Mylotarg (gemtuzumab ozogamicin).

We analyzed the safety and efficacy of Mylotarg (gemtuzumab ozogamicin, an antibody-targeted chemotherapy consisting of a humanized anti-CD33 antibody linked to calicheamicin, a potent antitumor antibiotic) in the treatment of 101 patients > or =60 years of age with acute myeloid leukemia (AML) in untreated first relapse in three open-label trials. Mylotarg is administered as a 2-h intravenous infusion at 9 mg/m(2) for two doses with 14 days between doses. The overall remission rate was 28%, with complete remission (CR) in 13% of patients and complete remission with incomplete platelet recovery (CRp) in 15%. Median survival was 5.4 months for all patients and 14.5 months and 11.8 months for patients achieving CR and CRp, respectively. CD33 antigen is present on normal hematopoietic progenitor cells; thus, an expected high incidence of grade 3 or 4 neutropenia (99%) and thrombocytopenia (99%) was observed. The incidences of grade 3 or 4 elevations of bilirubin and hepatic transaminases were 24% and 15%, respectively. There was a low incidence of grade 3 or 4 mucositis (4%) and infections (27%) and no treatment-related cardiotoxicity, cerebellar toxicity, or alopecia. Mylotarg is an effective treatment for older patients with CD33-positive AML in first relapse and has acceptable toxicity.

Acute Disease↗
PubMed2000

Phase I/II study of 2-chloro-2'-deoxyadenosine with cyclophosphamide in patients with pretreated B cell chronic lymphocytic leukemia and indolent non-Hodgkin's lymphoma.

Because of their substantial in vitro synergy, we conducted a dose-escalation study of cyclophosphamide (CP) added to 2-chloro-2'-deoxyadenosine (CdA) in patients with previously treated chronic lymphocytic leukemia and non-Hodgkin's lymphoma. CdA was given at a fixed dose (5.6 mg/m2/day) as a 2-h intravenous (i.v.) infusion, immediately followed by a 1-h i.v. infusion of CP, for 3 days. The initial daily CP dose was 200 mg/m2, and was escalated by 100 mg/m2 increments in successive cohorts of three to six patients to determine the maximum-tolerated dose (MTD). Additional patients were included at the MTD to extend toxicity and response analysis. Twenty-six patients received 68 cycles of chemotherapy. The MTD of CP after CdA 5.6 mg/m2, was 300 mg/m2. Acute neutropenia was the dose-limiting toxicity of this regimen, which was otherwise well tolerated. Delivery of repeated cycles was not feasible in eight patients (31%) because of prolonged thrombocytopenia. Severe infections were seen in three of 68 cycles (4%). The overall response rate was 58% (15 of 26; 95% CI, 36-76%), with 15% complete responses and 42% partial responses. These data show the feasibility of the association of CdA with CP. Given the response rate observed, further studies of this regimen are warranted in untreated patients, in particular with chronic lymphocytic leukemia and with Waldenström macroglobulinemia.

Adult↗
PubMed2000

Long-term follow-up confirms the benefit of all-trans retinoic acid in acute promyelocytic leukemia. European APL group.

First results of a randomized trial (APL91 trial) and other randomized or non-randomized studies have shown that ATRA followed by chemotherapy significantly increased event-free survival (EFS) and survival, and decreased the incidence of relapse by comparison to chemotherapy alone in newly diagnosed APL. We present here long-term follow-up of the APL91 trial. In this trial, 101 patients had been randomized between ATRA followed by three courses of daunorubicin-AraC chemotherapy (ATRA group) and the same chemotherapy alone (chemotherapy group). Results were reanalyzed 73 months after closing of patient entry. Updated results of APL 91 trial found a Kaplan-Meier estimate of EFS and relapse rate at 4 years of 63% and 31% in the ATRA group, as compared to 17% and 78% in the chemotherapy group (P= 10(-4) and relative risk 2.95, P= 10(-4) and relative risk 3.68, respectively). Kaplan-Meier survival at 4 years was 76% in the ATRA group and 49% in the chemotherapy group (P= 0.026, relative risk 2.7). In the chemotherapy group, seven of the 27 relapses occurred after 18 months, but no relapse was seen after 43 months. In the ATRA group, four of the 17 relapses occurred after 18 months, including two late relapses (at 58 and 74 months). In the chemotherapy group, 23 of the 25 patients who relapsed achieved a second CR with ATRA, and the Kaplan-Meier estimate of second relapse was 40% at 30 months. In the ATRA group, the 10 patients who relapsed and were retreated with ATRA achieved a second CR. In conclusion, long-term results of APL91 trial confirm the superiority of the combination of ATRA and chemotherapy over chemotherapy alone in newly diagnosed APL, and that ATRA should be incorporated in the front-line treatment of APL.

Antineoplastic Agents↗
PubMed1999

Hypercalcemia, chronic lymphocytic leukemia and multiple myeloma: uncommon association.

A fifty-nine year old woman is admitted with severe hypercalcemia and other metabolic disorders. The buffy coat showed plasmoblasts in association with chronic lymphocytic leukemia cells (CLL). Immunophenotyping revealed different light chains on CLL cells and in plasmoblasts. We discuss the association of hypercalcemia and CLL, its physiopathology and the distinction with Richter's Syndrome. We also review literature descriptions of the uncommon association of CLL and Multiple Myeloma and raise the question of its clonal origin.

Diagnosis, Differential↗
PubMed1998

Ultrastructural distribution of DNA within plant meristematic cell nucleoli during activation and the subsequent inactivation by a cold stress.

We have investigated the precise location of DNA within the meristematic cell nucleolus of Zea mays root cells and Pisum sativum cotyledonary buds, in the course of their activation and induced inactivation following a subsequent treatment at low temperature. For this purpose, we combined the acetylation method, providing an excellent distinction between the various nucleolar components, with the in situ terminal deoxynucleotidyl transferase-immunogold technique, a highly sensitive method for detecting DNA at the ultrastructural level. In addition to the presence of DNA in the condensed chromatin associated with the nucleolus, we demonstrated that a significant label was detected in the nucleolus of quiescent cells in both plant models. Evident labels were also found in the dense fibrillar component of actived nucleoli. Whereas in inactivated nucleoli no significant label was observed within the dense fibrillar component, an intense label was seen over the large heterogeneous fibrillar centres only during inactivation. The granular component was never significantly labelled. These results appear to indicate that the DNA present in the dense fibrillar component of activated nucleoli withdraws from this structure during its inactivation and becomes incorporated in the large fibrillar centres. These observations suggest that in plant cells inactivation of rRNA genes is clearly accompanied by changes in the conformation of ribosomal chromatin.

Cell Nucleolus↗
PubMed1998

2-Chlorodeoxyadenosine with or without daunorubicin in relapsed or refractory acute myeloid leukemia.

2-Chlorodeoxyadenosine (2-CdA) is a purine analogue which has proved to be active in acute myeloid leukemia (AML), especially in children. In adults, results yielded by 2-CdA alone or with ara-C were less encouraging. Here we report on the efficacy of 2-CdA with or without daunorubicin (DNR) in 19 relapsing or refractory adult AML patients, with a median age of 57 years. 2-CdA was administered as a continuous infusion to all patients at a dose of 0.1 mg/kg per day for 7 days. For 14 patients, DNR was added at a dose of 50 mg/m2 per day on days 5, 6, and 7. Antileukemic activity was observed in all the patients, but no single complete remission was achieved. One patient had a long-lasting partial response (response rate=5%). The remaining patients died of progressive AML (n=7), uncontrollable infection with persistent disease (n=10), and cerebral hemorrhage (n=1). Median survival from start of 2-CdA therapy was 56 days. Long-lasting neutropenia and transfusion-dependent thrombopenia were encountered in all 16 evaluable patients. Grade 4 hepatic toxicity occurred in one patient. Other side effects included nausea in six, mucositis in three, and mental disturbances in three patients. Compared with 2-CdA alone, the addition of DNR to 2-CdA changed neither the response rate nor the toxicities. In conclusion, our data do not support the use of 2-CdA +/- DNR for relapsing or refractory adult AML patients, at least as used in the present regimen.

Adolescent↗
PubMed1998

VAD or VMBCP in multiple myeloma refractory to or relapsing after cyclophosphamide-prednisone therapy (protocol MY 85).

263 patients (median age 65+/-10 years) with multiple myeloma were treated with cyclophosphamide-prednisone. Out of this cohort, 103 patients had progressive disease and were randomly assigned to either VAD (vincristine, doxorubicin, dexamethasone; 50 cases) or VMBCP (vincristine, BCNU, cyclophosphamide, melphalan and prednisone; 53 cases). There were no statistical differences between the two groups with the respect to clinical, biological and radiological parameters. There was no difference in survival between the VAD and VMBCP groups. The 4 months response rate was similar in the two groups (50% VAD, 56% VMBCP). With multivariate analysis for survival (Cox model), two factors had a statistically significant impact: Karnofsky index (> 60) and albuminaemia (< 34 g/l). With both Karnofsky index > 60 and albuminaemia > or = 34 g/l, the median survival was 29 months v 2 months with a Karnofsky index < or = 60 and albuminaemia < 34 g/l (P<0.05). In conclusion, VAD or VMBCP had similar activity for salvage treatment in MM refractory or relapsing to first-line treatment with cyclophosphamide-prednisone.

Adult↗
PubMed1996

Infectious complications after 2-chlorodeoxyadenosine therapy.

Infection is a common adverse event after therapy with nucleoside analogs, including 2-chlorodeoxyadenosine (CdA). However, the incidence of CdA-related infections has been poorly documented. In this study we compare, in the same patient population, the incidence of infectious episodes during the 6-month period before CdA to their incidence during the 6 months after initiating therapy. Ninety-five patients with hematological malignancies were studied. The incidence of infectious episodes almost doubled after CdA (0.87 vs. 0.47 during the pre-CdA period). The following factors were associated with an increased risk of infection after therapy: a history of previous chemotherapy, infection during the pre-CdA period and a diagnosis of chronic lymphocytic leukemia or of non-Hodgkin's lymphoma. Age, neutrophil and lymphocyte count at onset of CdA and time interval between diagnosis and therapy with CdA did not correlate with the infectious risk. The pattern of infections was modified after therapy with an increase of herpes virus infections ( 1 vs. 8 episodes, p=0.04) and of fever of unknown origin (6 vs. 17 episodes, p=0.03). In conclusion, a population at high risk for developing infectious complications after CdA therapy can be identified. Specific measures aimed at reducing the incidence of infectious events should concentrate on this population.

Adult↗
PubMed1996

Is the small non-cleaved-cell lymphoma histologic subtype a poor prognostic factor in adult patients? A case-controlled analysis. The Groupe d'Etude des Lymphomes de l'Adulte.

PURPOSE: To study the prognostic significance of the small non-cleaved-cell lymphoma (SNCCL) histologic subtype, we compared the outcome of adult patients with SNCCL with that of patients with aggressive lymphoma other than SNCCL by means of two case-controlled studies. PATIENTS AND METHODS: We analyzed the results of the doxorubicin, cyclophosphamide, vindesine, bleomycin, and prednisone (ACVBP) regimen used as a reference scheme in our cooperative study group (Groupe d'Etude des Lymphomes de l'Adult [GELA]) in 52 adult SNCCL patients with no bone marrow (BM) or CNS involvement. Forty-five SNCCL patients younger than 60 years could be compared with two separate case-matched groups of patients with aggressive lymphoma other than SNCCL undergoing the same therapeutic regimen. In the first case-controlled study, matching ensured identity of each risk factor of the age-adjusted International Index (ie, Ann Arbor stage, performance status, and lactate dehydrogenase [LDH] level); in the second study, matching was performed according to the number of presenting risk factors (zero, one, two, or three), regardless of their nature. RESULTS: The 5-year overall survival rates were not significantly different between SNCCL and control patients in both case-controlled studies: 48% versus 51% in the first study, and 48% versus 55% in the second study. CONCLUSION: These results support the thesis that in patients with no bone marrow or CNS involvement, the SNCCL histologic subtype does not confer a prognosis worse than that of other aggressive lymphoma.

Adolescent↗
PubMed1995

Karyotype in acute myeloblastic leukemia: prognostic significance in a prospective study assessing bone marrow transplantation in first remission.

To evaluate the prognostic value of the karyotype in acute myeloblastic leukemia when patients are allocated to have either autologous bone marrow transplantation (BMT) or allogeneic BMT at the time of first remission (CR1), we have prospectively followed 134 consecutive patients from diagnosis. CR was achieved in 118 patients. Allogeneic BMT and autologous BMT were performed in 25 and 43 CR1 patients, respectively. Applying the karyotype classification of Keating et al for remission duration (favorable: t(15;17), inv(16); intermediate: normal, X -Y, t(8;21); unfavorable: other abnormalities), 10 patients had a favorable, 49 an intermediate, and 44 an unfavorable karyotype. The 5-year leukemia-free survival (LFS) probabilities for patients with a good, intermediate and unfavorable karyotype were 65%, 32% and 11%, respectively (log rank test P = 0.0019). The probabilities of relapse were 35% in patients with a favorable karyotype, 52% with an intermediate karyotype and 87% with an unfavorable karyotype (P = 0.0004). In the patients who had autologous BMT in CR1, the LFSs were 100%, 33% and 10% with favorable, intermediate and unfavorable karyotype, respectively (P = 0.04). The karyotype was of no prognostic value in patients receiving allogeneic BMT who had BMT in CR1. This study shows that the karyotype retains its prognostic value when the intentions is to treat patients with acute myeloblastic leukemia in CR1 with BMT. Autologous BMT was not able to improve the poor prognosis associated with an unfavorable karyotype.

Adolescent↗
PubMed1994

A single course of 2-chloro-deoxyadenosine does not eradicate leukemic cells in hairy cell leukemia patients in complete remission.

The nucleoside analog 2-chlorodeoxyadenosine (2-CdA) has recently emerged as a most promising treatment for hair-cell leukemia (HCL). The response rates are high regardless of prior therapy, and the duration of complete responses (CR) after a single course of treatment is longer than with any other therapeutic agent. We investigated the presence of minimal residual disease (MRD) in ten HCL patients treated in our institution with 2-CdA. The presence of residual leukemic cells was investigated in patients in CR following one course of treatment, using the polymerase chain reaction (PCR) and heavy-chain immunoglobulin genes (IgH), or TCR delta derived clonospecific probes. Eight patients achieved a complete remission after a single course of treatment, as evaluated at 6 months. Among these patients, seven are still in CR with a median follow-up of 12 months (range, 6-20 months) and one has relapsed after 15 months. Using PCR, all the evaluable patients remaining in CR showed persistent evidence of detectable MRD with no sign of decrease over the observation period. From this small series, we conclude that a single course of 2-CdA does not eradicate HCL and that persistence of residual leukemic cells appears to be common in patients in complete morphologic remission. Whether persistence of MRD will have an impact on long-term outcome, or whether HCL patients in morphologic CR with persistent MRD will remain so, is a matter of longer follow-up.

Aged↗
PubMed1987

Feminizing testicular Leydig cell tumor: hormonal profile before and after unilateral orchidectomy.

The effect of chronic hyperestrogenism on gonadal function was studied in three men who had estrogen-secreting Leydig cell tumors before unilateral orchidectomy and for 11-43 months after surgery. All three men had low plasma gonadotropin and testosterone levels and increased estradiol levels. Impairment of testicular steroidogenesis was also suggested by increased progesterone to 17-hydroxyprogesterone and 17-hydroxyprogesterone to androstenedione ratios in both spermatic venous plasma and the medium of Leydig tumor cells from one patient incubated in vitro. Before surgery, spermatogenesis was abnormal in two men. Testicular endocrine function and spermatogenesis did not return to normal after surgery. During the follow-up period, plasma gonadotropin levels were high in all three men, and testosterone was low normal. Estradiol levels decreased to normal immediately after surgery and then returned to the upper normal limit. The response to hCG stimulation in one man was subnormal. We conclude that chronic hyperestrogenism produced hypothalamo-pituitary inhibition as well as direct steroidogenic blockade at the testicular level. Long term impairment of both endocrine and exocrine testicular functions may be secondary to slowly reversible (or irreversible) estrogen-induced damage to tubular and Leydig cells.

Adult↗