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O Delattre

Publications and source records attributed to O Delattre.

At least 55 records · Page 3Linked to original sources
PubMed1999

[Sagittal changes induced by knee arthroplasty: a radiologic study].

PURPOSE OF THE STUDY: To quantify the modifications occurring on the femoral side, after Total Knee Arthroplasty, we describe a method of measurements in the sagittal plane on standardized X-rays. MATERIAL AND METHODS: We report the clinical and radiologic results of a prospective study of 80 cases of Total Knee Arthroplasty performed with the same prosthesis. We eliminated twenty cases with incorrect X-rays. Measurements were done on 60 preoperative X-rays and 60 postoperative X-rays. The aim of the measure was to quantify the modifications induced by the prosthesis on the trochlear groove and on the tibio-femoral joint line in full extension and in flexion, to eliminate individual femoral diameter was used as a reference in order to cancel variations in X-rays magnification. We first validated the two perpendicular reference axis on which we based all the measurements. RESULTS: No significative difference was found on the position of the tibio-femoral joint line in flexion. The tibio-femoral joint line in extension was significantly moved distally. The prosthesis was placed too distally, therefore we changed the operative procedure. No significative difference was found on the position of the anterior trochlear groove. DISCUSSION: With this method, the anatomic variations of the femoral profiles can be quantified, therefore, further prosthesis shapes can be improved. Radiological follow-up of knee prosthesis and comparison of the influence of different prosthesis can be made by these measures.

Aged↗
PubMed1998

Truncating mutations of hSNF5/INI1 in aggressive paediatric cancer.

Malignant rhabdoid tumours (MRTs) are extremely aggressive cancers of early childhood. They can occur in various locations, mainly the kidney, brain and soft tissues. Cytogenetic and molecular analyses have shown that the deletion of region 11.2 of the long arm of chromosome 22 (22q11.2) is a recurrent genetic characteristic of MRTs, indicating that this locus may encode a tumour suppressor gene. Here we map the most frequently deleted part of chromosome 22q11.2 from a panel of 13 MRT cell lines. We observed six homozygous deletions that delineate the smallest region of overlap between the cell lines. This region is found in the hSNF5/INI1 gene, which encodes a member of the chromatin-remodelling SWI/SNF multiprotein complexes. We analysed the sequence of hSNF5/INI1 and found frameshift or nonsense mutations of this gene in six other cell lines. These truncating mutations of one allele were associated with the loss of the other allele. Identical alterations were observed in corresponding primary tumour DNAs but not in matched constitutional DNAs, indicating that they had been acquired somatically. The observation of bi-allelic alterations of hSNF5/INI1 in MRTs suggests that loss-of-function mutations of hSNF5/INI1 contribute to oncogenesis.

Child↗
PubMed1998

Desmoplastic small round cell tumor: RT-PCR analysis and immunohistochemical detection of the Wilm's tumor gene WT1.

Desmoplastic small round cell tumor is an aggressive neoplasm first described in 1991. Recently, a reciprocal translocation t(11;22)(p13;q12) has been characterized by conventional cytogenetic studies and molecular analysis. This translocation involves the Ewing's sarcoma gene on chromosome 22 and the Wilms' tumor gene WT1 on chromosome 11. The chimeric transcript corresponding to the fusion gene could be detected by the reverse transcriptase-polymerase chain reaction (RT-PCR). Using an anti-WT1 antibody, the WT1 part of the putative chimeric protein could be recognized by immunohistochemistry. We describe two well-characterized cases of intraabdominal desmoplastic small round cell tumor in two male patients aged 14 and 28 with both RT-PCR analysis and immunostaining for WT1. In this report, we insist on the necessity to increase the RT-PCR analysis in DSRCT in order to obtain a precise differential diagnosis. In addition, WT1 immunostaining may serve as a useful diagnostic marker for DSRCT.

Abdominal Neoplasms↗
PubMed1998

Solid alveolar rhabdomyosarcoma of the thorax in a child.

AIMS: This case illustrates the difficulties and pitfalls of diagnosis of alveolar rhabdomyosarcoma in its solid variant and in an unusual primary location, the mediastinum. CASE DETAILS: A 9-year-old boy presented with a primary thoracic tumour associated with metastasis in the left sacroiliac joint. Bronchial and mediastinal biopsies showed a malignant neoplasm with a solid sheet-like pattern of small round cells with a high nuclear to cytoplasmic ratio associated with little or no fibrosis usually evocative of a peripheral neuroectodermal tumour (PNET) at this age. Immunohistochemical positive staining with vimentin (80% of tumour cells), desmin (20%) and titin (30%) antibodies was suggestive of a rhabdomyosarcoma. In addition, all neural cell adhesion molecule (NCAM) markers tested were positive as well as MIC2, a marker for the Ewing family of sarcomas. There was no rhabdomyoid differentiation at ultrastructural examination. Molecular analysis with RT-PCR amplification of RNA isolated from the tumour demonstrated the presence of a PAX3/FKHR fusion transcript, product of a t(2;13) reciprocal translocation, a genetic marker specific for alveolar rhabdomyosarcoma. CONCLUSIONS: The diagnostic methodology of a small round cell tumour of the child must now include immunohistochemical study and molecular biology to confirm the diagnosis of alveolar rhabdomyosarcoma, in a solid and undifferentiated variant.

Bronchial Neoplasms↗
PubMed1998

EWS, but not EWS-FLI-1, is associated with both TFIID and RNA polymerase II: interactions between two members of the TET family, EWS and hTAFII68, and subunits of TFIID and RNA polymerase II complexes.

The t(11;22) chromosomal translocation specifically linked to Ewing sarcoma and primitive neuroectodermal tumor results in a chimeric molecule fusing the amino-terminus-encoding region of the EWS gene to the carboxyl-terminal DNA-binding domain encoded by the FLI-1 gene. As the function of the protein encoded by the EWS gene remains unknown, we investigated the putative role of EWS in RNA polymerase II (Pol II) transcription by comparing its activity with that of its structural homolog, hTAFII68. We demonstrate that a portion of EWS is able to associate with the basal transcription factor TFIID, which is composed of the TATA-binding protein (TBP) and TBP-associated factors (TAFIIs). In vitro binding studies revealed that both EWS and hTAFII68 interact with the same TFIID subunits, suggesting that the presence of EWS and that of hTAFII68 in the same TFIID complex may be mutually exclusive. Moreover, EWS is not exclusively associated with TFIID but, similarly to hTAFII68, is also associated with the Pol II complex. The subunits of Pol II that interact with EWS and hTAFII68 have been identified, confirming the association with the polymerase. In contrast to EWS, the tumorigenic EWS-FLI-1 fusion protein is not associated with either TFIID or Pol II in Ewing cell nuclear extracts. These observations suggest that EWS and EWS-FLI-1 may play different roles in Pol II transcription.

Animals↗
PubMed1998

Presence of tumor cells in bone marrow but not in blood is associated with adverse prognosis in patients with Ewing's tumor. Société Française d'Oncologie Pédiatrique.

PURPOSE: Gene fusions that result from the chromosome translocations observed in Ewing's tumor (ET) provide tumor-specific markers that can be used to detect the presence of tumor cells in peripheral blood (PB), bone marrow (BM), and stem cell collection (SCC). These markers were used to evaluate, at diagnosis, a series of 67 ET patients. PATIENTS AND METHODS: RNA was extracted from nucleated cells from PB and BM and a nested reverse-transcriptase polymerase chain reaction (RT-PCR) was performed to search for EWS-FLI-1 or EWS-ERG fusion transcripts that resulted from the t(11;22) or t(21;22) translocations, respectively. RESULTS: At diagnosis, 16 of 62 (26%) patients had circulating tumor cells. This was not correlated with any clinical parameter. In contrast, Ewing's cells were detected by RT-PCR in BM in 14 of 43 (33%) patients and were associated with the presence of clinically detectable metastases and a statistically significant unfavorable outcome in univariate analysis. There was no correlation between the RT-PCR results in PB and in BM. CONCLUSION: These results suggested that the monitoring of BM but not of PB by RT-PCR might constitute an important criterion for the staging, at diagnosis, of patients with ET. Further studies should appreciate the relationship or independence of this marker toward other classical prognostic factors in ET, particularly to the presence of clinically detectable metastases.

Adolescent↗
PubMed1998

Cytogenetic and molecular analysis of a t(1;22)(p36;q11.2) in a rhabdoid tumor with a putative homozygous deletion of chromosome 22.

Malignant rhabdoid tumors are rare and aggressive neoplasms of childhood, occurring in the kidney or in various extrarenal locations. Most cytogenetic studies of these tumors have shown the frequent involvement of chromosome 22, including translocations and/or deletions, with a critical region for a rhabdoid tumor gene mapping to chromosome segment 22q11, close to BCR. We report a case of an extrarenal rhabdoid tumor with a t(1;22)(p36;q11.2) that was associated with deletions of chromosomes 1 and 22. We have performed fluorescence in situ hybridization to bracket the translocation breakpoints on both chromosomes and microsatellite analysis to establish the deletion of chromosome 22 more precisely. The chromosome 22 translocation breakpoint is localized close to BCR, in the region covered by the overlapping YACs 446B5 and 361D9, and it is associated with a proximal hemizygous deletion of approximatively 2 Mb. On chromosome 1, the translocation breakpoint maps to a 25 cM region, proximal to D1Z2 and distal to PND, and is also associated with an estimated deletion of 8 Mb. Moreover, microsatellite analysis has demonstrated a homozygous deletion of chromosome 22 for three contiguous loci, immediately distal to BCR. This result suggests that a tumor suppressor gene involved in rhabdoid tumor oncogenesis could be localized in this region of chromosome 22.

Chromosomes, Human, Pair 1↗
PubMed1998

[Biological markers for the prognosis of neuroblastoma: proposal of a method of analysis].

The prognosis of pediatric neuroblastoma depends both on clinical presentation and on certain cellular and molecular characteristics. At the present time, two hypotheses can be drawn to explain both clinical and biological heterogeneity. In the first hypothesis, neuroblastoma progresses from early to late clinical stages through a classical multistep process linked to an accumulation of molecular abnormalities. In the second hypothesis, neuroblastoma represents an heterogeneous group of unrelated diseases, where most of stages I and II or stage IVS neuroblastomas can rather be considered as benign tumors, and stage IV neuroblastoma as a true malignant proliferation. To ascertain relevant biological factors for the prognosis of the disease, it is uppermost important that all investigators agree on biological criteria for analysis when neuroblastoma tissue is available in screened and unscreened populations. This paper reviews the biological tools available for prognosis in neuroblastoma, the priority for analysis of biological markers according to reliability, feasibility, and reproducibility of analysis procedure, and the conditions of tissue storage for further analysis of these biological markers. The standardized biological evaluation of neuroblastoma will allow, first, to collect sufficient data for multivariate analysis of prognostic factors and, second, to better define the putative links between various forms of the disease.

Biomarkers, Tumor↗
PubMed1998

[A familial form of bilateral recurrent dislocation of the patella with major trochlea dysplasia].

PURPOSE OF THE STUDY: We report four cases of bilateral recurrent dislocation of the patella with major trochlear dysplasia, in the same family. MATERIAL AND METHODS: Details of clinical examination of all members of this family and measurements on knee radiographs are reported. RESULTS: In all cases a severe proximal dysplasia of the trochlea was described on lateral views. The patella and the trochlea had a normal shape on the axial view. DISCUSSION: In some recurrent dislocation, with no associated disease, possibility of a genetic transmission have been suggested in some publications. Cases involving the same family have never been reported to confirm a genetic transmission of a bilateral and major trochlear dysplasia. CONCLUSION: This report points out a genetic origin of severe trochlear dysplasia. To know more about transmission and chromosomic localisation, careful investigations on others families of bilateral dislocations with trochlear dysplasia must be done.

Adolescent↗
PubMed1997

The prooncoprotein EWS binds calmodulin and is phosphorylated by protein kinase C through an IQ domain.

A growing family of proteins is regulated by protein kinase C and calmodulin through IQ domains, a regulatory motif originally identified in neuromodulin (Alexander, K. A., Wakim, B. T., Doyle, G. S., Walsh, K. A., and Storm, D. R. (1988) J. Biol. Chem. 263, 7544-7549). Here we report that EWS, a nuclear RNA-binding prooncoprotein, contains an IQ domain, is phosphorylated by protein kinase C, and interacts with calmodulin. Interestingly, PKC phosphorylation of EWS inhibits its binding to RNA homopolymers, and conversely, RNA binding to EWS interferes with PKC phosphorylation. Several other RNA-binding proteins, including TLS/FUS and PSF, co-purify with EWS. PKC phosphorylation of these proteins also inhibits their binding to RNA in vitro. These data suggest that PKC may regulate interactions of EWS and other RNA-binding proteins with their RNA targets and that IQ domains may provide a regulatory link between Ca2+ signal transduction pathways and RNA processing.

3T3 Cells↗
PubMed1997

Polymerase chain reaction compared with dot blotting for the determination of N-myc gene amplification in neuroblastoma.

The magnitude of N-myc amplification (NMA) influences the treatment strategy of localized neuroblastomas. Reliable assays are therefore needed for all types of tumor samples. The aim of this comparative study of 119 tumor samples was to determine whether a polymerase chain reaction (PCR)-based assay could replace the current dot blot assay as a routine and reliable means of determining NMA. The 2 assays exhibited comparable sensitivity and were completely concordant for samples containing at least 20% neuroblastoma cells. In their present state, both assays remain semi-quantitative since an absolute quantification of the N-myc copy number in clinical samples is limited by uncertainty about the amplification level of reference cell lines and by the estimation of the proportion of malignant cells. However, PCR offers several advantages over dot blotting, such as feasibility on minute samples, simplicity, standardization, rapidity and cost effectiveness.

Cost-Benefit Analysis↗
PubMed1997

A new member of the ETS family fused to EWS in Ewing tumors.

As a result of chromosome translocations, the EWS gene is fused to a variety of transcription factors in human solid neoplasia. In Ewing tumors EWS can be fused to four different members of the ETS family, namely FLI-1, ERG, ETV1 and E1AF. We have identified a new member of the ETS family, called FEV, which is fused to EWS in a subset of Ewing tumors. FEV encodes a 238 amino acid protein which contains an ETS DNA binding domain closely related to that of FLI-1 and ERG. However, the N-terminal portion of FEV is only 42 amino acids long which suggests that FEV is lacking important transcription regulatory domains contained in FLI-1 and ERG N-terminal parts. The C-terminal end of FEV is rich in alanine residues which may indicate that FEV is a transcription repressor. The FEV gene is encoded by three exons and is located on chromosome 2. FEV expression was only detected in adult prostate and small intestine but not in other adult nor in fetal tissues, thus indicating that FEV has a restricted expression pattern. Following a scheme similar to previously described translocations in Ewing tumors, a t(2;22) chromosome translocation fuses the N-terminal domain of EWS to the ETS DNA binding domain of FEV.

Adult↗
PubMed1997

Interethnic polymorphism of EWS intron 6: genome plasticity mediated by Alu retroposition and recombination.

The EWS gene has been identified as being systematically translocated in Ewing's sarcoma. In order to ascertain the basis of a marked interethnic difference in the incidence of Ewing's sarcoma, intron 6 of EWS, which is located near the translocation breakpoint region (EWSR1), was characterized. Sequence analysis of the entire intron 6 region revealed a very high density of Alu elements. Most of these Alu sequences could be classified in previously described subfamilies, facilitating delineation of an evolutionary model that involves successive retroposition events. According to this model, the EWS intron 6 region progressively expanded until about 5 million years ago. More recently (10(5) years ago), in part of the human population, the size of this region decreased by over 50% as the result of a homeologous recombination between two Alu sequences, which removed 2480 bp. This rare allele has only been observed in individuals of African origin, a population that is characterized by the lowest incidence of Ewing's sarcoma.

Alleles↗
PubMed1997

Multiple chromosomal mechanisms generate an EWS/FLI1 or an EWS/ERG fusion gene in Ewing tumors.

The t(11;22)(q24;q12) translocation is found in about 85% of Ewing tumors and leads in all cases to an EWS/FLI1 fusion gene. In a few instances, complex translocations, involving chromosomes 11, 22 and a third chromosome or other variant translocations not involving chromosome 11 also have been reported. These rearrangements generate an active fusion gene between the EWS gene and either the human FLI1 gene or other members of the ETS gene family: the ERG gene localized in band 21q22.2, the ETV1 gene localized in band 7p22, or the E1AF gene localized in band 17q12. Using fluorescence in situ hybridization (FISH) on interphase nuclei or metaphases, we report here the characterization of particular karyotypes in Ewing tumors, namely a complex t(2;11;22) translocation, a variant t(12;22) translocation, and one Ewing tumor without specific rearrangements but with an EWS/ERG fusion gene demonstrated by molecular analysis. These molecular cytogenetic methods allowed us (1) to precisely localize the genomic breakpoints within-EWSR1 and EWSR2 and to identify the chromosome carrying the fusion gene; (2) to determine the nature of events generating the fusion genes; (3) to demonstrate that some variant translocations represent masked complex translocations; and (4) to show that the generation of an EWS/ERG fusion gene cannot be obtained through a simple balanced translocation.

Chromosome Aberrations↗
PubMed1997

[Shortening arthrodesis of three wrist bones].

In advanced cases of wrist osteoarthritis with lesions of the radio-scaphoid and mediocarpal joints, and when a proximal row carpectomy is not possible because of lesions of the head of the capitate, we suggest a new technique: The hamate-capitate-lunate shortening arthrodesis with a scaphoid-triquetral resection. The good results observed with proximal row carpectomies, and particularly their long-term reliability, have encouraged us on this new path. Effectively, this operation takes the concept of proximal row carpectomy one step further by reconstructing the head of the capitate with the lunate whose proximal articular surface is often not deteriorated even in very advanced cases of radio and mediocarpal osteoarthritis. The two theoretical concepts of this operation are the shortening of the carpus and respect of the physiological congruence of the radio-lunate joint, the goal being obtain similar results those with proximal row carpectomy, particularly concerning mobility. We present our first two cases with this technique. This new procedure is an alternative to the four bone arthrodesis, particularly in SLAC wrist sequellae when they have evolved to the stage of radio and mediocarpal osteoarthritis.

Aged↗
PubMed1997

Loss of chromosome 1p may have a prognostic value in localised neuroblastoma: results of the French NBL 90 Study. Neuroblastoma Study Group of the Société Française d'Oncologie Pédiatrique (SFOP).

Between March 1990 and December 1994, 316 consecutive children with localised neuroblastoma were registered in the French NBL 90 study. In addition to the assessment of a new chemotherapy regimen in unresectable neuroblastoma, we evaluated the prognostic significance of MYCN amplification and loss of the short arm of chromosome 1 (LOH1p). MYCN was found in 22/225 children (10%) and associated with unfavourable clinical features such as age at diagnosis > 1 year and large and unresectable tumours. LOH1p was observed in 9/91 patients (10%), of whom some had favourable prognostic factors such as age at diagnosis < 1 year (n = 4), INSS stage 1 or 2 (n = 3) and no MYCN amplification (n = 4). Overall survival (OS) and event-free survival (EFS) were, respectively, 56% and 22% (median follow-up: 36 months) for children with LOH1p compared with 97% and 94% for those without (log-rank = 10(-8)). All except 1 of the 5 children with MYCN amplification and LOH1p relapsed and ultimately died of the disease. Among the 4 with LOH1p and no MYCN amplification, recurrence occurred in 3 (2 local, 1 metastatic), all alive in second remission after salvage therapy (12-19 months after the relapse). In multivariate analysis, LOH1p was the strongest prognostic indicator for subsequent relapse. LOH1p appears more discriminant than MYCN amplification for predicting the risk of recurrence in children with localised neuroblastoma. However, its analysis was possible in only 30% of our patients and its final impact on survival should be confirmed in larger, prospective studies in order to stratify subsequent treatment.

Abdominal Neoplasms↗
PubMed1997

[New biological prognostic factors of soft tissue sarcoma. SFOP (Société française d'oncologie pédiatrique)].

Malignant tumors of soft tissue constitute a very heterogeneous group of tumors which is composed of more than 50 different entities derived from either the mesenchyme or the neuroectoderm. Diagnostic problems can be linked to the difficulty to firmly establish the diagnosis of malignancy and to the precise determination of the type of sarcoma. The prognostic is largely dependent on local and distant extension of the cancer. The study of the genotype of tumor cells has enabled the detection and characterization of genetic alterations. These alterations, frequently chromosome translocations, are specific markers for subgroups of tumors and can thus be of clinical relevance. These markers can be detected by cytogenetic, in situ hybridization or molecular biology techniques. The specificity of these alterations for tumor cells and the possibility to detect them with the highly sensitive polymerase chain reaction (PCR) technique have enabled development of tests aimed at the detection of tumor cells within potential metastatic sites.

Genetic Markers↗