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Y Benoit

Publications and source records attributed to Y Benoit.

At least 19 recordsLinked to original sources
PubMed2006

Clinical, cytogenetic and molecular characteristics of 14 T-ALL patients carrying the TCRbeta-HOXA rearrangement: a study of the Groupe Francophone de Cytogénétique Hématologique.

Recently, we and others described a new chromosomal rearrangement, that is, inv(7)(p15q34) and t(7;7)(p15;q34) involving the T-cell receptor beta (TCRbeta) (7q34) and the HOXA gene locus (7p15) in 5% of T-cell acute lymphoblastic leukemia (T-ALL) patients leading to transcriptional activation of especially HOXA10. To further address the clinical, immunophenotypical and molecular genetic findings of this chromosomal aberration, we studied 330 additional T-ALLs. This revealed TCRbeta-HOXA rearrangements in five additional patients, which brings the total to 14 cases in 424 patients (3.3%). Real-time quantitative PCR analysis for HOXA10 gene expression was performed in 170 T-ALL patients and detected HOXA10 overexpression in 25.2% of cases including all the cases with a TCRbeta-HOXA rearrangement (8.2%). In contrast, expression of the short HOXA10 transcript, HOXA10b, was almost exclusively found in the TCRbeta-HOXA rearranged cases, suggesting a specific role for the HOXA10b short transcript in TCRbeta-HOXA-mediated oncogenesis. Other molecular and/or cytogenetic aberrations frequently found in subtypes of T-ALL (SIL-TAL1, CALM-AF10, HOX11, HOX11L2) were not detected in the TCRbeta-HOXA rearranged cases except for deletion 9p21 and NOTCH1 activating mutations, which were present in 64 and 67%, respectively. In conclusion, this study defines TCRbeta-HOXA rearranged T-ALLs as a distinct cytogenetic subgroup by clinical, immunophenotypical and molecular genetic characteristics.

Adolescent↗
PubMed2006

The Eighth International Childhood Acute Lymphoblastic Leukemia Workshop ('Ponte di legno meeting') report: Vienna, Austria, April 27-28, 2005.

The International Acute Lymphoblastic Leukemia Working Group, the so-called 'Ponte di Legno Workshop' has led to substantial progress in international collaboration in leukemia research. On April 27-28, 2005, the 8th Meeting was held in Vienna, Austria, to continue the discussions about special common treatment elements in randomized clinical trials, ethical and clinical aspects of therapy. Furthermore, collaborative projects of clinical relevance with special emphasis on rare genetic subtypes of Childhood ALL were established. The following report summarizes the achievements and aspects of possible future cooperation.

Austria↗
PubMed2005

A new recurrent inversion, inv(7)(p15q34), leads to transcriptional activation of HOXA10 and HOXA11 in a subset of T-cell acute lymphoblastic leukemias.

Chromosomal translocations with breakpoints in T-cell receptor (TCR) genes are recurrent in T-cell malignancies. These translocations involve the TCRalphadelta gene (14q11), the TCRbeta gene (7q34) and to a lesser extent the TCRgamma gene at chromosomal band 7p14 and juxtapose T-cell oncogenes next to TCR regulatory sequences leading to deregulated expression of those oncogenes. Here, we describe a new recurrent chromosomal inversion of chromosome 7, inv(7)(p15q34), in a subset of patients with T-cell acute lymphoblastic leukemia characterized by CD2 negative and CD4 positive, CD8 negative blasts. This rearrangement juxtaposes the distal part of the HOXA gene cluster on 7p15 to the TCRbeta locus on 7q34. Real time quantitative PCR analysis for all HOXA genes revealed high levels of HOXA10 and HOXA11 expression in all inv(7) positive cases. This is the first report of a recurrent chromosome rearrangement targeting the HOXA gene cluster in T-cell malignancies resulting in deregulated HOXA gene expression (particularly HOXA10 and HOXA11) and is in keeping with a previous report suggesting HOXA deregulation in MLL-rearranged T- and B cell lymphoblastic leukemia as the key factor in leukaemic transformation. Finally, our observation also supports the previous suggested role of HOXA10 and HOXA11 in normal thymocyte development.

Adolescent↗
PubMed2005

Results of 58872 and 58921 trials in acute myeloblastic leukemia and relative value of chemotherapy vs allogeneic bone marrow transplantation in first complete remission: the EORTC Children Leukemia Group report.

The first EORTC (European Organization of Research and Treatment of Cancer) acute myeloblastic leukemia (AML) pilot study (58872) was conducted between January 1988 and December 1991. Out of 108 patients, 78% achieved complete remission (CR), and event-free survival (EFS) and survival rates (s.e., %) at 7 years were 40 (5) and 51% (6%), respectively. It indicated that mitoxantrone could be substituted for conventional anthracyclines in the treatment of childhood AML without inducing cardiotoxicity. The aim of the next EORTC 58921 trial was to compare the efficacy and toxicity of idarubicin vs mitoxantrone in initial chemotherapy courses, further therapy consisting of allogeneic bone marrow transplantation (alloBMT) in patients with an HLA-compatible sibling donor or chemotherapy in patients without a donor. Out of 177 patients, recruited between October 1992 and December 2002, 81% reached CR. Overall 7-year EFS and survival rates were 49 (4) and 62% (4%), respectively. Out of 145 patients who received the first intensification, 39 had a sibling donor. In patients with or without a donor, the 7-year disease-free survival (DFS) rate was 63 (8) and 57% (5%) and the 7-year survival rate was 78 (7) and 65% (5%), respectively. Patients with favorable, intermediate and unfavorable cytogenetic features had a 5-year EFS rate of 57, 45 and 45% and a 5-year survival rate of 89, 67 and 53%, respectively.

Adolescent↗
PubMed2005

Assessing the role of alkane hydroxylase genotypes in environmental samples by competitive PCR.

AIMS: A molecular tool for extensive detection of prokaryotic alkane hydroxylase genes (alkB) was developed. AlkB genotypes involved in the degradation of short-chain alkanes were quantified in environmental samples in order to assess their occurrence and ecological importance. METHODS AND RESULTS: Four primer pairs specific for distinct clusters of alkane hydroxylase genes were designed, allowing amplification of alkB-related genes from all tested alkane-degrading strains and from six of seven microcosms. For the primer pair detecting alkB genes related to the Pseudomonas putida GPo1 alkB gene and the one targeting alkB genes of Gram-positive strains, both involved in short-chain alkane degradation (<C10), a quantitative competitive PCR (cPCR) assay was developed and validated on alkB-containing strains. AlkB genes of the two groups were then quantified in hydrocarbon-contaminated and pristine freshwater and soil samples, and their respective frequency was compared to degradation rates of short-chain n-alkanes. Pseudomonas putida-related alkB genes were prevalent in freshwater samples, but Gram-positive alkB-containing strains were more consistently related to alkane degradation activities. The latter genotype was more abundant in soils, although both genotypes increased in the most contaminated soils studied. CONCLUSIONS: Predominance of alkB genotypes depends on the ecosystem and environmental conditions, but alkane exposure generally leads to an increase of both studied genotypes. SIGNIFICANCE AND IMPACT OF THE STUDY: The study illustrates the distribution of two different alkB genotypes in two types of ecosystems, and highlights their respective roles in the environment.

Alkanes↗
PubMed2002

Symptomatic pineal cysts: clinical manifestations and management.

Between 1991 and 2000, seven patients presented with symptomatic pineal cysts at our hospital (6 females, 1 male). Average age was 22 years (range 4-33 years). Headache was present in 6 patients, who were subsequently operated on. A scotoma and a transient inferior visual field deficit were minor signs in two patients respectively. A Parinaud syndrome with vertical gaze paralysis was found in none. In one child, paroxysmal pupillary dilatations and contractions ('springing pupils') constituted the only signs and a conservative policy was adopted. Four patients presented with hydrocephalus and were treated by an endoscopic resection of their pineal cysts (one stereotactically, three free-hand). Two other patients presented with a prolonged history of symptoms and signs: headache alone in one, headache with discrete neurological deficits in the other. Ventricles in these two patients were not dilated and therefore an open cyst resection by infratentorial supracerebellar approach was performed. Average follow-up in the six "operated" patients was 29 months (range 12-108 months). All four patients treated by endoscopy, are symptom-free at follow-up, whereas the two who were approached by open surgery, are not. Clinical presentation, radiological evaluation and treatment modalities of pineal cysts are discussed and compared with experiences reported in the literature. It is concluded that pineal cysts in the presence of obstructive hydrocephalus are a clear indication for endoscopy with a rigid endoscope.

Adolescent↗
PubMed2002

[Anaphylaxis after rocuronium: advantage of blood tests for early diagnosis].

A 56-year-old patient was scheduled for coronary artery bypass surgery, because of a severe coronary artery disease. Soon after induction of anaesthesia, he rapidly developed a cardiovascular collapse with bronchospasm and rash. Specific immunoglobulin E and tryptase measurements supported the diagnosis of grade III anaphylactic shock due to rocuronium bromide. A few days later, a general anaesthesia was administered without muscle relaxant and was uneventful.

Anaphylaxis↗
PubMed2001

Chromosomal aberrations in Bloom syndrome patients with myeloid malignancies.

Bloom syndrome (BS) predisposes affected individuals to a wide variety of neoplasms including hematological malignancies. Thus far, cytogenetic findings in hematological neoplasms have been reported in only a few BS patients. We present the karyotypic findings in a BS patient diagnosed with acute myeloid leukemia (AML), FAB subtype M1, and a review of the literature, showing the preferential occurrence of total or partial loss of chromosome 7 in BS patients with AML or myelodysplastic syndromes (MDS).

Acute Disease↗
PubMed2001

Value of high-dose cytarabine during interval therapy of a Berlin-Frankfurt-Munster-based protocol in increased-risk children with acute lymphoblastic leukemia and lymphoblastic lymphoma: results of the European Organization for Research and Treatment of Cancer 58881 randomized phase III trial.

PURPOSE: The European Organization for Research and Treatment of Cancer 58881 study was designed to test in a prospective multicentric randomized trial the value of high-dose (HD) intravenous (IV) cytarabine (Ara-C) added to HD IV methotrexate (MTX) to reduce the incidence of CNS and systemic relapses in children with increased-risk acute lymphoblastic leukemia (ALL) or stage III and IV lymphoblastic lymphoma treated with a Berlin-Frankfurt-Munster (BFM)-based regimen. PATIENTS AND METHODS: After completion of induction-consolidation phase, children with increased-risk (risk factor > 0.8 or T-lineage) ALL or stage III and IV lymphoblastic lymphoma were randomized to receive four courses of HD MTX (5 g/m(2) over 24 hours every 2 weeks) and four intrathecal administrations of MTX (Arm A) or the same treatment schedule with additional HD IV Ara-C (1 g/m(2) in bolus injection 12 and 24 hours after the start of each MTX infusion) (Arm B). RESULTS: Between January 1990 and January 1996, 653 patients with ALL (593 patients) or lymphoblastic lymphoma (60 patients) were randomized: 323 were assigned to Arm A (without Ara-C) and 330 to Arm B (with Ara-C). A total of 190 events (177 relapses and 13 deaths without relapse) were reported, and the median follow up was 6.5 years (range, 2 to 10 years). The incidence rates of CNS relapse were similar in both arms whether isolated (5.6% and 3.3%, respectively) or combined (5.3% and 4.6%, respectively). The estimated 6-year disease-free survival (DFS) rate was similar (log-rank P =.67) in the two treatment groups: 70.4% (SE = 2.6%) in Arm A and 71.0% (SE = 2.5%) in Arm B. The 6-year DFS rate was similar for ALL and LL patients: 70.2% (SE = 1.9%) versus 76.3% (SE = 5.6%). CONCLUSION: Prevention of CNS relapse was satisfactorily achieved with HD IV MTX and intrathecal injections of MTX in children with increased-risk ALL or stage III and IV lymphoblastic lymphoma treated with our BFM-based treatment protocol in which cranial irradiation was omitted. Disappointingly, with the dose schedule used in this protocol, HD Ara-C added to HD MTX, although well tolerated, failed to further decrease the incidence of CNS relapse or to improve the overall DFS.

Actuarial Analysis↗
PubMed2001

[Immune deficiencies: diagnosis, management, some perspectives].

Severe primary immunodeficiencies (PID) are rare; their global incidence is comparable to that of childhood leukemia; they include more than 100 different entities. Clinical manifestations are: unusually severe or frequent infections or infections that do not respond to adequate treatment; an increased risk of certain malignancies; sometimes auto-immune manifestations. Delayed diagnosis and management of PID can lead to severe and irreversible complications or to death. PID can become manifest only in the adult; in common variable immune deficiency, the median age at diagnosis is between the 2nd and the 3rd decade of life. PID are often transmitted genetically; recent progresses in molecular biology have allowed more precise and earlier, including antenatal, diagnosis. Molecular treatment of 3 infants with a severe immunodeficiency has recently been achieved in April 2000. Those progresses were mostly based on the study of immunodeficiency databases. We present here the work of a Belgian group specialized in PID; meetings have started in June 1997. This group establishes guidelines for the diagnosis and treatment of PID, adapted to the local situation. The elaboration of a national register of PID is also underway; this has to provide all guaranties of anonymity to patients and families. Such a register already exists at the European level; it has provided the basis for new diagnostic and therapeutic possibilities. The inclusion of Belgian data in this register should allow essential progresses essential for our patients.

Adolescent↗
PubMed2000

Long-term results of three randomized trials (58831, 58832, 58881) in childhood acute lymphoblastic leukemia: a CLCG-EORTC report. Children Leukemia Cooperative Group.

We present here the long-term results of three randomized clinical trials conducted on children with newly diagnosed acute lymphoblastic leukemia (ALL) between 1983 and 1998 by the Children Leukemia Cooperative Group (CLCG) from EORTC. In study 58831/32, the overall event-free survival (EFS) rates (+/- s.e.) at 6 and 10 years were 66% +/- 1.8% and 65% +/- 1.8%, respectively, and the risk of isolated central nervous system (CNS) relapse was 6% +/- 1% and 7% +/- 1%, respectively. In patients with a standard risk of relapse the omission of cyclophosphamide had no adverse effect on disease-free survival rates at 10 years (trial 58831). In medium- and high-risk patients the omission of radiotherapy did not increase the risk of CNS or systemic relapse (trial 58832). In study 58881 (1989-1998) the overall EFS rate at 8 years was 68.4% +/- 1.2% and the risk of isolated CNS relapse was 4.2%+/-0.5%. In this trial which adressed three randomized questions, the following results were obtained: the combination of cytarabine at high doses with methotrexate at high doses during interval therapy did not improve prognosis. The addition of 6-mercaptopurine iv during maintenance increased the risk of late relapse. E. coli asparaginase was more toxic and has a higher efficacy than Erwinia asparaginase. Leukocyte counts >100 x 10(9)/l, specific genetic abnormalities, a poor initial response to steroids or a high level of minimal residual disease at early time points were consistently associated with an adverse prognosis in the 58881 trial.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Discrepant flow cytometric expression and function of P-glycoprotein in neuroblastic tumors.

BACKGROUND: Patients suffering from neuroblastic tumors are currently being classified into prognostic subsets based on different clinical and biologic features. In this study, a triple-color flow cytometric assay and a functional test were applied to neuroblastoma cell lines and patients with a neuroblastic tumor, and the value of P-glycoprotein expression and function as potential prognostic characteristics, was determined. METHODS: Twenty-two single-cell suspensions prepared from tumors, and neuroblasts from four bone marrow samples were analyzed by triple-color flow cytometry. Neuroblasts were identified by NB84-positivity and absence of CD45. P-glycoprotein expression was evaluated using 4E3 and MRK16 antibodies. Eighteen samples were tested with a functional assay, based on accumulation and retention of rhodamine-123 with and without the inhibitor verapamil. Six neuroblastoma cell lines were also evaluated. RESULTS: P-glycoprotein expression was seen in 18 of 26 patient samples and in three of six cell lines. The highest expression levels were found in low stage neuroblastoma and well-differentiated tumors; whereas the highest activities were found in stage 4 neuroblastoma and the lowest in ganglioneuroblastoma and ganglioneuroma patients. In 10 of 17 samples, concordant results were found between the flow cytometric immunological test and immunocytochemistry. CONCLUSIONS: The described flow cytometric technique is a new, alternative approach to detect P-glycoprotein expression and function in neural crest tumors. Based on the expression level and the activity value, patients can be segregated into different phenotypic groups. In particular, those patients with high P-glycoprotein activity might benefit from treatment regimens containing reversal agents.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

Technetium-99m sestamibi imaging in paediatric neuroblastoma and ganglioneuroma and its relation to P-glycoprotein.

Imaging with technetium-99m sestamibi offers a non-invasive approach to detect the presence of functional P-glycoprotein (Pgp), one of the major causes of multidrug resistance, in human malignancies. A clinical role for Pgp has been suggested in the subpopulation of primary neuroblastoma without amplification of the proto-oncogene MYCN. We wanted to evaluate the usefulness of 99mTc-sestamibi scintigraphy in the screening of neural crest tumours for the presence of Pgp. In ten children suffering from MYCN-negative neuroblastoma, ganglioneuroblastoma or ganglioneuroma, 99mTc-sestamibi imaging was performed at initial diagnosis. All patients underwent planar imaging 20-30 min and 3.5-4 h after intravenous injection of 740 MBq/1.73 m2 99mTc-sestamibi. Tumour to normal tissue ratios, as well as washout rates, were determined and compared with in vitro flow cytometric analysis of Pgp expression and function. Pgp expression was analysed flow cytometrically with the monoclonal antibodies 4E3 and MRK16, and Pgp function was evaluated by means of rhodamine 123 uptake and efflux either in the absence or in the presence of the Pgp inhibitor verapamil. In nine of ten patients, we found that the intratumoral 99mTc-sestamibi activity was comparable to the background activity, which might be suggestive of Pgp presence. This was confirmed flow cytometrically in all but one patient. 99mTc-sestamibi enhancement was seen in the primary tumour and the bone marrow metastases of one of the ten patients, and this result was concordant with a negative Pgp status. The findings presented suggest that 99mTc-sestamibi imaging results might correlate with the presence of functional Pgp in neural crest tumours without MYCN amplification.

3-Iodobenzylguanidine↗
PubMed1999

P-glycoprotein is an independent prognostic factor predicting relapse in childhood acute lymphoblastic leukaemia: results of a 6-year prospective study.

P-glycoprotein (P-gp), a cellular drug-efflux pump, is thought to be one of the major causes of multidrug resistance (MDR) in malignancies. Since therapeutic strategies are being developed to circumvent drug resistance by inhibiting P-gp function, large prospective studies evaluating the clinical relevance of P-gp in childhood acute lymphoblastic leukaemia (ALL) are warranted. P-gp expression was evaluated over a period of 6 years in 102 consecutive patients with de novo childhood ALL and in 35 children with relapse of ALL. Bone marrow and blood smears were studied immunocytochemically with two monoclonal antibodies at initial diagnosis and at relapse. P-gp expression was found in 14 (14%) patients at initial diagnosis. After induction treatment, complete remission was achieved in 100/102 patients (98%), of whom 19 relapsed. Cumulative event-free survival was significantly higher in the P-gp-negative group compared with the P-gp-positive population (Logrank P = 0.02). Multivariate analysis showed the results to be independent of age, WBC count and karyotype, and concomitantly underlined the importance of MDR1 phenotype detection in childhood ALL. P-gp expression was more frequently found at relapse (34%) than at primary diagnosis (P = 0.01). In the relapsed patient group, P-gp-positive patients had a 2-fold greater risk for adverse clinical outcome than the P-gp-negative relapsed patients. P-gp expression was not induced by exposure to previous chemotherapy since the majority of P-gp-negative patients remained negative at relapse. P-glycoprotein expression in newly diagnosed childhood ALL is an independent adverse prognostic parameter with a predictive value for relapse.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

The belgian experience in unrelated donor bone marrow transplantation: identification of center experience as an important prognostic factor.

BACKGROUND AND OBJECTIVE: We reviewed all unrelated donor bone marrow transplants (UDBMT) performed in Belgium up to December 1995 to identify prognostic factors for relapse, transplant-related mortality and survival. DESIGN AND METHODS: A total of 163 UDBMT were performed in 92 males and 71 females aged 1-55 (median 26) years. Patients were transplanted for ALL (n=35), AML (n=34), CML (n=51), other myeloid malignancies (n=14), SAA (n=21) or miscellaneous other diseases (n=8). Most patients had advanced disease; a few patients were in CR1 (n=10) or early chronic phase (CP) of CML (n=5). RESULTS: Overall survival at 5 yrs was 17% (95% confidence interval: 8-32%), but survival was significantly better for patients with non-malignant disorders (55% at 4 yrs). The relapse rate +/-SE was projected to be 40 (28-54)% at 5 yrs, 36 (20-56)% for standard-risk and 68 (43-85)% for high-risk malignancies (p=0.0029). There was no relapse in CML patients transplanted in 1st CP compared to 68% at 4 yrs with more advanced CML (p=0.0033). Grade II-IV acute graft-versus-host disease (aGVHD) occurred in 55% by day 100 and was strongly modulated by age, ranging from 41% in <20-yr-old to 80% in >40-yr-old patients (p=0. 0021). Transplant-related mortality (TRM) was projected to be 72 (52-87)% at 5 yrs including 2 very late deaths from lung fibrosis and secondary cancer. Main causes of death were original disease in 27, secondary malignancy in 2, GVHD in 28, interstitial pneumonia in 21, other infections in 19, and miscellaneous toxic causes in 21 patients. In multivariate analysis, the relapse rate was strongly dependent on the disease status (p=0.0029), TRM being significantly worse with older age (p=0.0049), and overall survival being significantly worse in more advanced disease (p=0.0006), after a second transplant (p=0.0166), in centers of smaller size (p=0.0316) and in older patients (NS). INTERPRETATION AND CONCLUSIONS: Although results have improved somewhat in recent years, UDBMT remains a procedure with a high TRM. UDBMT should be performed in patients with less advanced diseases and in centers with more experience, particularly in the treatment of adult patients.

Adolescent↗