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O Delattre

Publications and source records attributed to O Delattre.

At least 19 recordsLinked to original sources
PubMed2007

hSNF5/INI1-deficient tumours and rhabdoid tumours are convergent but not fully overlapping entities.

Rhabdoid tumours (RTs) are rare but highly aggressive tumours of childhood. Their rarity and their miscellaneous locations make the diagnosis particularly challenging for pathologists. Central nervous system and peripheral RTs have been associated with biallelic inactivation of the hSNF5/INI1/SMARCB1 (hSNF5/INI1) tumour suppressor gene. Immunohistochemistry (IHC) with a monoclonal anti-hSNF5/INI1 antibody has recently been proposed as an efficient diagnostic tool for RTs. We have conducted a retrospective study of 55 tumours referred to our institution with a suspicion of RT. This analysis included pathological review, IHC with anti-hSNF5/INI1 antibody, and molecular investigation using quantitative DNA fluorescent analysis and sequencing of the nine exons of hSNF5/INI1. The molecular lesion could be detected in 37 of the 39 cases exhibiting negative staining for hSNF5/INI1. In the two discrepant cases, the lack of detection of genetic abnormality was probably owing to the presence of a high number of non-tumour cells in the samples. This indicates that hSNF5/INI1 IHC is very sensitive and highly specific for the detection of hSNF5/INI1 loss-of-function. Among the 38 cases with typical RT histological features, six failed to exhibit hSNF5/INI1 mutation and stained positive for hSNF5/INI1. This strongly supports the evidence of a second genetic locus, distinct from hSNF5/INI1, associated with RT. Conversely, seven tumours with histological features poorly compatible with RT stained negative for hSNF5/INI1; they nevertheless exhibited an age of onset and a clinical behaviour similar to RT. This suggests that hSNF5/INI1 inactivation is not strictly limited to typical RT but characterizes a wider family of hSNF5/INI1-deficient tumours. Consequently, we believe that anti-hSNF5/INI1 IHC should be performed widely, even when the pathological characteristics are not typical. The molecular investigation should be performed in infants when a rhabdoid predisposition syndrome is suspected.

Adult↗
PubMed2006

Incidence and prognostic value of tumour cells detected by RT-PCR in peripheral blood stem cell collections from patients with Ewing tumour.

To retrospectively evaluate the incidence of tumour cell contamination of peripheral blood stem cell (PBSC) collections and to correlate these data with the clinical outcome after high-dose chemotherapy (HDCT) with stem cell rescue in patients with a high-risk Ewing tumour. Peripheral blood stem cell collections obtained from 171 patients were analysed. Tumour contamination was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR). The files of 88 patients who underwent HDCT followed by PBSC reinfusion were reviewed in detail, and their outcome compared to the PBSC RT-PCR results. Seven of 88 PBSC collections (8%) contained tumour cells as detected by RT-PCR. Peripheral blood stem cells were collected after a median of five cycles of chemotherapy. No clinical factor predictive of tumour cell contamination of PBSC harvest could be identified. Event-free survival (EFS) and overall survival (OS) of the whole study population were 45.3 % and 51.8 % at 3 years from the date of the graft, respectively. Forty-five patients relapsed with a median time of 15 months after graft, only four of whom had tumour cell contamination of the PBSC harvest. Tumour cell contamination of PBSC collection is rare and does not seem to be associated with a significantly poorer EFS or OS in this high-risk population.

Adolescent↗
PubMed2006

[Allograft-prosthesis composite arthroplasty for posttraumatic floating elbow].

Loss of bone stock in the elbow joint raises serious problems for reconstruction surgery. Total allograft-prosthesis composite arthroplasty is an attractive alternative to revision prosthesis and isolated osteoarticular allografts known to have many drawbacks. Use of this method is rather recent for revision procedures and tumor surgery and posttraumatic cases are rare (five reported cases). We report a case of posttraumatic floating elbow treated with this technique. At 75 months follow-up, the clinical result was excellent with the Mayo Clinic performance score at 100/100. Allograft-native bone fusion was complete and there were no complications, particularly no loosening. This composite technique is particularly well adapted for patients with major bone and joint loss. It can avoid the specific problems associated with each of the techniques used alone. The allograft reconstructs bone stock while the prosthetic component avoids the clinical expression of graft epiphyseal lysis.

Arthroplasty, Replacement↗
PubMed2006

[Traumatic rupture of the tibialis posterior tendon after ankle fracture: three cases and a review of the literature].

We report three cases of complete traumatic tibialis posterior tendon rupture which occurred after ankle fracture. Diagnosis was established at surgery. Repair of the non-degenerative tendon was achieved during the procedure for osteosynthesis of the malleolar fracture. Fractures healed a few months after surgery. The posterior tibialis muscle tendon functioned plantar arch was normal, except in one patient with multiple injuries who died in intensive care thirteen days after the accident. Although exceptional, injury of the tibialis posterior tendon should not be overlooked after ankle fracture. These injuries become apparent only at surgery for the malleolar fracture since pain hinders clinical examination. Primary suture best guarantees a good functional outcome. Residual pain, deficit in active inversion of the foot, modified medial longitudinal arch, or progression to planovalgus are retrospective diagnostic signs.

Adult↗
PubMed2005

Nacre/bone interface changes in durable nacre endosseous implants in sheep.

Raw nacre implants persist even after 9 months of implantation into bone tissue in sheep. However the nacre surface undergoes a limited biodegradation process. Smooth-surfaced nacre implants were seen to become microporous after implantation. The results of these long-term, in vivo studies show that the overall process involves bone-resorbing cells, relies on a two-phase mechanism and may correspond to a regulation process. The rate of surface change depends on the bone implantation site and the nacre/bone interaction. The in vivo biodegradability of nacre is a highly variable parameter. The size and shape of the implanted nacre and the cellular environment of the implant are key factors in determining the biodegradation kinetics of the nacre in a living system.

Animals↗
PubMed2005

[Long-term follow-up after leg replantation].

Leg replantation is generally considered to yield good results, particularly since the widespread use of progressive lengthening procedures. This optimism must be weighted against the very long and difficult operative program, the social and occupational implications, and the functional outcome of the replanted limb. We report a case of below knee leg replantation in a young patient whose operative program lasted 29 months. Occupational activities were interrupted for three years. The clinical result was satisfactory but with 14 degrees residual valgus suggesting a potential risk of osteoarthritis and difficult therapeutic decisions. The alternatives to replantation are controversial. Leg transplantation is not a valid option in our opinion. Amputation with orthesis should be considered more often because complications are rare and recovery much shorter. Indications for leg replantation should be considered with prudence.

Adult↗
PubMed2004

[Biphasic ceramic wedge and plate fixation with locked adjustable screws for open wedge tibial osteotomy].

PURPOSE OF THE STUDY: The aim of this radiological study was to evaluate the use of a biphasic ceramic wedge combined with plate fixation with locked adjustable screws for open wedge tibial osteotomy. MATERIAL AND METHODS: Twenty-six consecutive patients (27 knees) underwent surgery between December 1999 and March 2002 to establish a normal lower-limb axis. The series included 6 women and 20 men, mean age 50 years (16 right knees and 11 left knees). Partial weight-bearing with crutches was allowed on day 1. A standard radiological assessment was performed on day 1, 90, and 360 (plain AP and lateral stance films of the knee). A pangonogram was performed before surgery and at day 360. Presence of a lateral metaphyseal space, development of peripheral cortical bridges, and osteointegration of the bone substitute-bone interface were evaluated used to assess bone healing. The medial tibial angle between the line tangent to the tibial plateau and the anatomic axis of the tibia (beta) was evaluated to assess preservation of postoperative correction. The HKA angle was determined. RESULTS: Three patients were lost to follow-up and 23 patients (24 knees) were retained for analysis. At last follow-up, presence of peripheral cortical bridges and complete filling of the lateral metaphyseal space demonstrated bone healing in all patients. Good quality osteointegration was achieved since 21 knees did not present an interface between the bone substitute and native bone (homogeneous transition zone). The beta angle was unchanged for 23 knees. A normal axis was observed in patients (16 knees) postoperatively. DISCUSSION: Use of a biphasic ceramic wedge in combination with plate fixation with locked adjustable screws is a reliable option for open wedge tibial osteotomy. The bone substitute fills the gap well. Tolerance and integration are optimal. Bone healing is achieved. Plate fixation with protected weight bearing appears to be a solid assembly, maintaining these corrections.

Adult↗
PubMed2003

Quality assessment of genetic markers used for therapy stratification.

PURPOSE: Therapy stratification based on genetic markers is becoming increasingly important, which makes commitment to the highest possible reliability of the involved markers mandatory. In neuroblastic tumors, amplification of the MYCN gene is an unequivocal marker that indicates aggressive tumor behavior and is consequently used for therapy stratification. To guarantee reliable and standardized quality of genetic features, a quality-assessment study was initiated by the European Neuroblastoma Quality Assessment (ENQUA; connected to International Society of Pediatric Oncology) Group. MATERIALS AND METHODS: One hundred thirty-seven coded specimens from 17 tumors were analyzed in 11 European national/regional reference laboratories using molecular techniques, in situ hybridization, and flow and image cytometry. Tumor samples with divergent results were re-evaluated. RESULTS: Three hundred fifty-two investigations were performed, which resulted in 23 divergent findings, 17 of which were judged as errors after re-evaluation. MYCN analyses determined by Southern blot and in situ hybridization led to 3.7% and 4% of errors, respectively. Tumor cell content was not indicated in 32% of the samples, and 11% of seemingly correct MYCN results were based on the investigation of normal cells (eg, Schwann cells). Thirty-eight investigations were considered nonassessable. CONCLUSION: This study demonstrated the importance of revealing the difficulties and limitations for each technique and problems in interpreting results, which are crucial for therapeutic decisions. Moreover, it led to the formulation of guidelines that are applicable to all kinds of tumors and that contain the standardization of techniques, including the exact determination of the tumor cell content. Finally, the group has developed a common terminology for molecular-genetic results.

Biomarkers, Tumor↗
PubMed2003

[Assessment of the use of transfusion therapy and complications in orthopedic surgery in patients with sickle-cell anemia: retrospective study].

Red blood cells (RBCs) transfusion is a common practice in the treatment or for the prevention of complications of patients with sickle-cell disease. In surgery, pre-operative transfusions are frequently given to prevent peri-operative complications. There is no consensus however on the best regimen of transfusion for this purpose. The transfusion techniques are muliple. In addition, pre-operative transfusion therapy is reported to be largely responsible for an increased morbidity and mortality in patients with sickle cell anemia undergoing surgery. During the period 1990-2000, 16 patients (4 men and 12 women) with a mean age of 37 years and various major sickle cell hemoglobinopathies underwent 32 total hip arthroplasty for femoral head necrosis. Nine patients with sickle-cell trait were included as control group. Twelve of them had haemoglobin SS (HbSS), 2/16 had HbSC, 2/16 had HbS/betathalassemia. Operative transfusion were given in only 12/32 procedures, 4 were performed pre-operatively and 8 intra-operatively. Simple transfusion (mean: 2.5 packed red cells) were administered in all the procedures. The main complications observed in our patients were anemia by hemolysis and haemorrhagic shock, vaso-occlusive crisis and chest syndrome. Anemia requiring transfusions was significatively related to the procedures with pre-operative transfusion. In the light of our result, we would like to propose transfusional protocol--if needed--only intra-operatively.

Adolescent↗
PubMed2002

[Developmental lumbar stenosis in eleven French Antilles patients].

PURPOSE OF THE STUDY: Developmental lumbar stenosis is a rare entity, exceptionally described in the literature. No study has been directly devoted to this condition. The purpose of the present study was to examine specific features, particularly clinical and anatomic expression, observed in a series of operated patients. MATERIAL AND METHODS: Eleven patients from the French Antilles were treated for developmental lumbar stenosis between 1996 and 2000. The Verbiest criteria were used to define canal narrowness. Signs of degeneration and presence of discal herniation were exclusion criteria. Epidemiological and clinical data were collected for the 11 patients. The degree of sagittal stenosis (fixed diameter at the bone level and mobile diameter at the discal level) was measured on computed tomography images. Transverse stenosis was determined by measuring the interpedicular and interapophyseal distances. Lateral stenosis was determined by measuring the depth of the recessus. RESULTS: These patients were young (mean age 42.4 years). Most of the clinical signs were monoradicular. Discal level stenosis predominated, generally at level L4-L5. It was generally central and lateral, sagittal and transverse. The interpedicular distance was the only diameter that remained within normal limits. Soft tissues (yellow ligaments and joint capsules) played an important role in the stenosis. DISCUSSION: The rare reports of developmental lumbar stenosis describe decompensated stenosis due to discal herniation in the adolescent. Developmental lumbar stenosis is considered to be a genetic disease and its particular high frequency in the French Antilles favors this hypothesis. The stenosis results from bony (short pedicles, hypertrophic lateral masses) and ligament (hypertrophy of the yellow ligament and joint capsules) structures. CONCLUSION: Developmental lumbar stenosis produces a global (sagittal, transverse, central, lateral) narrowing of the lumbar canal where soft tissue structures apparently play a greater role than usually thought. A prospective study examining the impact of ethnic origin is required to analyze the genetic hypothesis.

Adult↗
PubMed2001

CGH analysis of secondary genetic changes in Ewing tumors: correlation with metastatic disease in a series of 43 cases.

The occurrence of secondary chromosome changes is frequent in Ewing tumors, in particular trisomies for chromosomes 8 and 12, and unbalanced (1;16) translocations leading to gains of 1q and losses of 16q. The prognostic value of these secondary aberrations has not been statistically demonstrated. We report here a CGH analysis of a series of 43 primary tumors corresponding to 21 localized and 22 metastatic tumors. For five of them, a sufficient amount of DNA for the CGH analysis was available from the frozen samples. For 19 samples, a preliminary step of DOP-PCR amplification of the DNA was necessary. For the last 19 tumors, DNA was obtained after DOP-PCR amplification of small amount of DNA contaminating the RNA. As a whole, the main chromosome imbalances previously described, such as trisomies for 1q, 8, and 12, were observed. It is noteworthy that the mean number of imbalances was more frequent in localized versus metastatic tumors. Gain of 1q was more frequent in metastatic than in localized tumors. Nevertheless, these two results do not reach statistical significance. Conversely, a statistically significant excess of copy number of chromosome 2 was observed in non-metastatic tumors, suggesting that this imbalance, which has never been previously reported, could be associated with more favorable tumor behavior.

Chromosome Aberrations↗
PubMed2001

Analysis of the expression of cell cycle regulators in Ewing cell lines: EWS-FLI-1 modulates p57KIP2and c-Myc expression.

Ewing tumour is characterized by specific chromosome translocations which fuse EWS to a subset of genes encoding ETS transcription factors, most frequently FLI-1. We report the analysis of the expression of various cell cycle regulators both in Ewing tumour derived cell lines and in different cellular models with either inducible or constitutive EWS-FLI-1 cDNA expression. In Ewing cell lines, cyclin D1, CDK4, Rb, p27KIP1 and c-Myc were consistently highly expressed whereas p57KIP2, p15INK4B and p14ARF demonstrated undetectable or low expression levels. The amount of p16INK4A, p21CIP1, p18INKAC and CDK6 was variable from one cell line to the other. The inducible expression of EWS-FLI-1 led to a strong upregulation of c-Myc and a considerable downregulation of p57KIP2. Other proteins did not show evident modification. High c-Myc and very low p57KIP2 expression levels were also observed in neuroblastoma NGP cells constitutively expressing EWS-FLI-1 as compared to parental cells. Analysis of the p57KIP2 promoter indicated that EWS-FLI-1 downregulates, possibly through an indirect mechanism, the transcription of this gene. Finally, we show that ectopic expression of p57KIP2 in Ewing cells blocks proliferation through a complete G1 arrest. These results suggest that the modulation of p57(KIP2) expression by EWS-FLI-1 is a fundamental step in Ewing tumorigenesis.

Base Sequence↗
PubMed2001

Comparative genomic hybridization (CGH) analysis of stage 4 neuroblastoma reveals high frequency of 11q deletion in tumors lacking MYCN amplification.

We have studied the occurrence and association of 11q deletions with other chromosomal imbalances in Stage 4 neuroblastomas. To this purpose we have performed comparative genomic hybridization (CGH) analysis on 50 Stage 4 neuroblastomas and these data were analyzed together with those from 33 previously published cases. We observed a high incidence of 11q deletion in Stage 4 neuroblastoma without MYCN amplification (59%) whereas 11q loss was only observed in 15% of neuroblastomas with MYCN-amplification (p = 0.0002) or 11% of cases with 1p deletion detected by CGH (p = 0.0001). In addition, 11q loss showed significant positive correlation with 3p loss (p = 0.0002). Event-free survival was poor and not significantly different for patients with or without 11q deletion. Our study provides further evidence that Stage 4 neuroblastomas with 11q deletions represent a distinct genetic subgroup that typically shows no MYCN-amplification nor 1p deletion. Moreover, it shows that neuroblastomas with 11q deletion also often present 3p deletion. This genetic subgroup shows a similar poor prognosis as MYCN amplified 4 neuroblastomas.

Adolescent↗
PubMed2001

Multicentre analysis of patterns of DNA gains and losses in 204 neuroblastoma tumors: how many genetic subgroups are there?

PROCEDURE: Analysis of comparative genomic hybridization (CGH) data of 120 tumors from four different studies, and data of 84 previously unpublishied tumors, allowed delineation of at least six different genetic subsets of neuroblastomas. RESULTS AND CONCLUSIONS: A small number of tumors show no detectable imballances. A second group of tumors presents with gains and losses of whole chromosomes and is found predominantly in prognostically favorable stage 1 and 2 tumors. The remaining groups are characterized by the presence of partial chromosome imbalances, and are found mostly in stage 3, 4, and 4S tumors. The third group shows 17q gain without 11q loss, 1p loss, or MYCN amplification (MNA). The fourth group has 1p deletion or MNA, and finally, a fifth group shows 11q loss without 1p deletion or MNA, and is found mainly in stage 4 tumors. The latter group is significantly associated with losses of 3p, 4p, and 14q.

Chromosome Aberrations↗
PubMed2001

Intracranial Ewing sarcoma/'peripheral' primitive neuroectodermal tumor of dural origin with molecular genetic confirmation.

Ewing sarcoma/'peripheral' primitive neuroectodermal tumor (ES/pPNET) is the designation given to a family of small cell neoplasms that typically arise in bone or soft tissue and are unified by their common expression of the MIC2 antigen and specific translocations involving a gene on chromosome 22q12 [the most common being t(11;22)(q24;q12)]. ES/pPNET of intracranial origin is extraordinary. We report the case of a 6-year-old boy with a large left frontal region mass that adhered to dura and was extracerebral at surgery. Histologic study revealed a high-grade, undifferentiated-appearing neoplasm of small cell type that was negative on immunostudy for glial fibrillary acidic protein, synaptophysin, desmin, leukocyte common antigen, smooth muscle actin and epithelial membrane antigen, but positive for vimentin and neuron-specific enolase and diffusely labeled by antibody O13 (which recognizes the MIC2 gene product). RNA-based polymerase chain reaction assay confirmed the diagnosis of ES/pPNET by demonstrating fusion transcripts indicative of t(11;22) translocation. Bone scan, computerized tomography of the chest and bone marrow examination revealed no systemic tumor. The limited observations published to date suggest that primary intracranial ES/pPNET is most likely to present in childhood as a circumscribed, contrast-enhancing and dural-based extracerebral mass. It must be distinguished from a variety of small cell neoplasms, particularly PNETs of central neuroepithelial origin.

Brain Neoplasms↗
PubMed2001

Inhibition of HIV-1 virion production by a transdominant mutant of integrase interactor 1.

Integase interactor 1 (INI1), also known as hSNF5, is a protein that interacts with HIV-1 integrase. We report here that a cytoplasmically localized fragment of INI1 (S6; aa183-294) containing the minimal integrase-interaction domain potently inhibits HIV-1 particle production and replication. Mutations in S6 or integrase that disrupt integrase-INI1 interaction abrogated the inhibitory effect. An integrase-deficient HIV-1 transcomplemented with integrase fused to Vpr was not affected by S6. INI1 was specifically incorporated into virions and was required for efficient HIV-1 particle production. These results indicate that INI1 is required for late events in the viral life cycle, and that ectopic expression of S6 inhibits HIV-1 replication in a transdominant manner via its specific interaction with integrase within the context of Gag-Pol, providing a novel strategy to control HIV-1 replication.

Base Sequence↗
PubMed2001

A multiplex real-time pcr assay for the detection of gene fusions observed in solid tumors.

SUMMARY: Specific gene fusions observed in solid tumors are extremely useful diagnostic markers. We report the development of a method based on real-time PCR which enables the detection upon identical PCR conditions of the different fusions specifically observed in Ewing tumors (ET), alveolar rhabdomyosarcoma (ARMS), synovial sarcoma (SS), small round cell desmoplastic tumors (SRCDT), extraskeletal myxoid chondrosarcoma, malignant melanoma of soft parts, congenital fibrosarcoma, and anaplastic large cell lymphoma. A simple assay, based on multiplexing of primers and probes, is described for the routine genetic diagnosis of small round cell tumors of children. It enables the detection of the five EWS-ETS, the two PAX-FKHR, the three SYT-SSX, and the EWS-WT1 fusions of ET, ARMS, SS, and SRCDT, respectively. The sensitivity of this test is high enough to detect all fusions, including the large EWS-FLI-1 transcripts, with the equivalent of 100 tumor cells as a starting material. This multiplex fluorescent analysis of chromosome translocations (MFACT) was validated in comparison with conventional RT-PCR on a series of 79 tumors. A major advantage of this method is that it completely abolishes the manipulation of PCR-products. It, therefore, considerably lowers the risk of cross-contamination linked to carry-over of RT-PCR products. It also constitutes an important step toward the complete automation of the detection of cancer-specific gene fusions.

Artificial Gene Fusion↗