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Biomedical subjects

D Leroux

Publications and source records attributed to D Leroux.

At least 37 records · Page 2Linked to original sources

Treatment of mantle-cell lymphomas with the VAD +/- chlorambucil regimen with or without subsequent high-dose therapy and peripheral blood stem-cell transplantation.

BACKGROUND: MCL is a well-described clinicobiological entity that presents the worst prognosis of the small-cell lymphomas. No treatment is known as the reference treatment. On the basis, first, of clinicobiological similarities between MCLs and multiple myelomas and, second, of our experience of chlorambucil in high intermittent dose in MCLs, we have treated MCL with the VAD regimen both with and without chlorambucil. PATIENTS AND METHODS: Thirty disseminated MCL patients from three institutions, most in relapse (70%), were treated with the classical VAD regimen: 4 weeks VAD for 12 patients and VAD with 12 mg chlorambucil (d20-d29) for 5 weeks (VAD+C) for 18 patients. Five patients received complementary high-dose therapy (Alkeran or cyclophosphamide HD with TBI) and peripheral blood stem-cell transplantation. RESULTS: Complete response was achieved in 43% of the patients in which 84.5% were treated by VAD+C. The median overall survival from the diagnosis was 52 months, and from the first VAD +/- C (OSvad) was 22.5 months, with a 20.5 month (0-75) median follow-up between diagnosis and the first VAD +/- C. The OSvad was significantly better for patients with fewer than two prognostic factors (ECOG, lymphocytosis, blastic variant, LDH level, and Ki-67 score). Four of five patients treated with HDT and PBSCT were alive in CR 12.5 months (7-22) after the first VAD +/- C regimen. CONCLUSION: The VAD regimen appears effective in disseminated MCL patients and even better when associated with chlorambucil. HDT and PBSCT appear promising in younger patients in CR before HDT. A multicenter prospective study is in preparation to confirm these encouraging results.

Aged↗

FISH analysis of translocations involving the short arm of chromosome 9 in lymphoid malignancies.

Deletion of the short arm of chromosome 9 (9p), resulting in the loss of the p16INK4a/MTS1 gene, now called CDKN2, has been found to occur frequently in acute lymphoblastic leukemia, even in the absence of a microscopically visible deletion. In this study, we have used YAC probes encompassing the CDKN2 locus to analyze by fluorescence in situ hybridization patients with leukemia and lymphoma and translocations involving 9p in order to establish the CDKN2 status in relation to the karyotype. We found that, in leukemic cells exhibiting loss of heterozygosity at the CDKN2 locus, the deleted allele was from the cytogenetically normal chromosome 9, whereas the other allele was located on a rearranged chromosome. This finding suggests that CDKN2 gene loss is nonrandomly associated with 9p translocation in lymphoid proliferations. Genes Chromosom.

Adult↗

Quantitative analysis of three-dimensional distribution of AgNOR proteins during interphase in leukemic cells.

Acidic proteins of the nucleolar organizer regions, selectively stained by silver (AgNOR-proteins), were investigated during interphase in leukemia cells with a confocal scanning laser microscope (CSLM). Simultaneous confocal fluorescence (for specific labeling of DNA, using propidium iodide) and transmitted light microscopy combined with digital deconvolution (for the location of the AgNOR proteins in nonconfocal mode) were used. The distribution of the AgNOR proteins measured by 3D microscopy was described by their number, the volume occupation of the nucleus by the AgNOR aggregates, the distance between each AgNOR, the distance of each AgNOR to the nucleolar border, and their anisotropy. The results of the 3D analysis were compared to those obtained by conventional 2D analysis, cytogenetical analysis of metaphase nucleolar organiser regions (NORs), and cell duplication rate. The descriptive power of these 3D parameters were assessed for nine leukemic cell lines. The measurements of the 3D spatial distribution of AgNORs was a better discriminant parameter than the morphological parameters (i.e., number and volume). The 3D expression of AgNORs is also a reliable parameter for assessing proliferative activity of leukemic cells and seems to be in relation with the differentiation stage of these leukemic cells.

Cell Division↗

[Wilms tumor and Bloom syndrome].

UNLABELLED: Bloom syndrome is characterized by growth failure, skin anomalies with sun sensitivity, minor anatomic defects, excessive chromosomic fragility and usually severe immune deficiency. The chromosome fragility predisposes these children to the development of hematologic malignancies and solid tumors. CASE REPORT: Morgan, a 4-year-old boy with Bloom syndrome, developed a Wilms tumor. Chemotherapy was poorly tolerated. Two years later, the child died from an uncontrolled progressive disease. CONCLUSION: This is the fourth reported case of Wilms tumor occurring in a child with Bloom syndrome. This possibility requires repeated abdominal ultrasonography in such patients.

Antineoplastic Combined Chemotherapy Protocols↗

Molecular diagnosis of t(11;14) in mantle cell lymphoma using two-colour interphase fluorescence in situ hybridization.

t(11;14) is observed in up to 70% of mantle cell lymphoma (MCL) cases and is therefore an important diagnostic element. In routine practice, detection of t(11;14) by conventional cytogenetic techniques is hindered by the low yield and quality of tumour metaphases. Molecular techniques (Southern blot, PCR) are unable to detect a large number of 11q13 breakpoints due to scattering over distances up to 1 Mb. Using 23 MCL patients with karyotypically determined t(11;14) and eight negative controls, we have devised a two-colour interphase FISH assay for detection of the 14q + chromosome. We chose an 11q13 probe telomeric to the major 11q13 translocation cluster sites and an IGH probe centromeric of the 14q32 breakpoints. This method detected the translocation in all 23 t(11;14) positive patients, with an overall average of 60% nuclei showing colocalized signals. Widespread application of this technique will constitute an important diagnostic aid in clinical management of MCL patients. Since FISH is a convenient method for retrospective analysis of large numbers of patient specimens, this method should contribute to an accurate estimation of t(11;14) frequency in MCL and other chronic B-cell malignancies and consequently to their better nosological characterization.

Chromosomes, Human, Pair 11↗

Present state of development of neo-electroencephalography.

Neo-electroencephalography (neo-EEG) is a new technique for recording and analyzing brain activity. Mathematical and computerized reconstitution yields a monopolar-like montage. Given the polymorphism of the brain's electrical activity, the computer detects the correct monopolar-like montage for each activity in steps of 0.25 Hz. Conventional EEG detects the difference in potentials between two electrodes. Through the use of monopolar-like montages neo-EEG analysis reveals the amplitude and phase that actually underlie each electrode. The report describes with precision the features of the recording extracts that have been chosen for the analysis, i.e., the number of dominant frequencies, the frequency to the nearest 0.25 Hz and the frequency spectrum for each dominant frequency, then the amplitude to the nearest 0.1 microv and phase shift to the nearest 0.001 sec at each electrode. Some examples of comparisons between neo-EEG and conventional EEG findings are shown and demonstrate the advantages of neo-EEG in detection and differentiation of organic and functional pathologies.

Alpha Rhythm↗

Implication of cyclin D1 in malignant lymphoma.

The chromosomal translocation t(11;14)(q13;q32) is observed in a number of lymphoid malignancies but is specifically associated with a particular subtype of non-Hodgkin's lymphoma called mantle cell lymphoma, where it is observed in up to 70% of cases. This translocation juxtaposes IGH sequences at 14q32 to a region variously termed BCL1/PRAD1 at 11q13, on the derivative chromosome 11. Detailed molecular analysis identified BCL1 to be a gene coding for the G1 cyclin, cyclin D1, which is an important regulator of the G1/S transition of the cell cycle. Cyclin D1 overexpression is observed in a vast majority of mantle cell lymphoma and lymphoid malignancies with 11q13 rearrangement, thereby confirming BCL1, now referred to as CCND1, as the gene targeted by these rearrangements. In this review, following a brief discussion of the role of cyclin D1 in cell cycle regulation, we discuss the mechanisms and pathogenetic impact of cyclin D1 activation in lymphoproliferative disorders with 11q13 rearrangement. We also review a number of the diagnostic strategies available for detection of CCND1 rearrangement/overexpression, with particular emphasis on applications for mantle cell lymphoma.

Animals↗

Autotumour reactive T-cell clones among tumour-infiltrating T lymphocytes in B-cell non-Hodgkin's lymphomas.

Seventy-three T-cell clones (TCC) were established from tumour-infiltrating lymphocytes-T (TIL-T) derived from lymph nodes involved by B-cell non-Hodgkin's lymphomas (B-NHL) in nine patients with different histological subtypes and clinical stages. 40 TCC (55%) expressed the CD25 Ag and were also able to proliferate in the presence of irradiated autologous B-NHL cells. Among them, 23 autotumour (AuTu) proliferative TCC were found not to proliferate to autologous EBV-transformed B-cell lines, indicating that the proliferative reactivity of these TCC was preferentially directed at autologous B-NHL cells. Tested against autologous B-NHL cells, only three AuTu proliferative TCC (CD8+) showed a significant level of cytotoxicity (specific lysis > 15%). In blocking experiments, the AuTu proliferative reactivity of three TCC from one patient was strongly inhibited by anti-DR and anti-DQ mAbs, whereas that of three TCC from another patient was not affected by either anti-MHC class I or class II (DR, DP, DQ) mAbs. These findings suggest that the recognition of autologous B-NHL cells by AuTu proliferative TCC may occur through MHC-restricted as well as MHC-unrestricted mechanisms.

Cell Division↗

Detection of NPM-ALK DNA rearrangement in CD30 positive anaplastic large cell lymphoma.

CD30 positive anaplastic large cell lymphoma (ALCL) is a type of non-Hodgkin's lymphoma associated with a specific chromosome translocation between chromosomes 2 and 5. Recent molecular characterization of the translocation breakpoint has identified a gene fusion between NPM (nucleophosmin) and ALK (anaplastic lymphoma kinase). Using a DNA hybridization technique, the NPM rearrangement was found among 5/5 ALCL samples. We have developed a PCT methodology which has enabled the detection of the NPM-ALK rearrangements amongst seven t(2;5)(p23;q35) ALCL cases based on a long-range PCR of genomic DNA. The rapidity and robustness of this method may have diagnostic applications for ALCL.

Anaplastic Lymphoma Kinase↗

[Primary synovial sarcoma of the mediastinum. A case report with immunohistochemistry, ultrastructural and cytogenetic study].

A biphasic synovial sarcoma occurring in the anterior and inferior mediastinum in a 19-year-old woman is reported. A biopsy showed a mesenchymal proliferation and the tumor was first misdiagnosed as a hemangiopericytoma. Inefficacy of chemotherapy led to a tumorectomy. Histologic and immunohistochemical studies on multiple samples showed a biphasic tumor. Ultrastructural study confirmed the presence of epithelial elements and cytogenetic analysis disclosed a translocation t(X;18) (p11;q11), leading to a diagnosis of synovial sarcoma. Synovial sarcoma of the mediastinum is very rare and to our knowledge has not been previously studied with the help of cytogenetics. Given the biphasic pattern of the tumor and its mediastinal location, it can be confused with mesothelioma. This stresses the interest of chromosome analysis in the study of tumors histologically difficult to classify.

Adult↗

Prognostic significance of karyotype in de novo adult acute myeloid leukemia. The BGMT group.

A group of 201 adult patients, 127 younger and 74 older than 55 years, with de novo acute myeloid leukemia were investigated to determine the prognostic significance of karyotype on early death (toxic or aplastic death occurring before hematopoietic recovery), drug resistance, continuous complete remission (CCR) and survival probabilities at 5 years. A good prognostic impact was found for t(8;21), t(15;17) and inv(16). The best factor proved to be t(8;21) (5-year survival probability: 50%), followed by t(15;17) (5-year survival probability: 39%) and by inv(16) (5-year survival probability: 43%). An intermediate outcome was found in patients with trisomy 8 (27% alive at 5 years) and in patients with numerical abnormalities other than -7 and +8 (33% in CCR and 62% alive at 5 years). Normal karyotypes had a different prognostic impact according to age: intermediate in young and good in older patients. A poor outcome was observed among patients with del(5q)/-5 (median survival: 1 month), with 11q23 rearrangements (median survival: 1.5 months) and with del(7q)/-7 (median survival: 10 months). The 'other structural change' group was also found to be a poor risk population (5-year survival probability: 5%) whereas complex karyotypes were predictive of short survivals only in older patients. Conversely, del(7q)/-7 and +8 as secondary changes, had no prognostic impact.

Acute Disease↗

Molecular analysis of a variant 18;22 translocation in a case of lymphocytic lymphoma.

We previously reported a 5' rearrangement of the BCL2 locus in a t(18;22) variant translocation found in a lymphocytic lymphoma. Primary structure analysis of both rearranged chromosomes confirmed the localization of the breakpoint in the so-called vcr region (for variant cluster region) that encompasses Z-DNA stretches 5' of the BCL2 locus, and in between J lambda 1 and C lambda 1 segments on the IGL locus. A 1,027 nucleotide segment from chromosome 22 was repeated on both derivative chromosomes 18q+ and 22q-. This segment contained an octanucleotide that was also present in the normal chromosome 18 close to the breakpoint. As a consequence of the translocation, a normal-sized BCL2 transcript was overexpressed in tumor cells.

Base Sequence↗

t(11;18)(q21;q21) may delineate a spectrum of diffuse small B-cell lymphoma with extranodal involvement.

We describe a patient with stage IV non-Hodgkin's lymphoma (NHL) and a t(11;18)(q21;q21) translocation. He presented with a gastric small B-cell lymphocytic lymphoma, expressing IgAL immunoglobulins without expression of CD10, CD5, and CD23 antigens. The lymphoma was the final development of a 6-year history of a monoclonal IgAL increase complicated by severe renal failure due to membranoproliferative glomerulonephritis. The clinical, histological, immunologic, and cytogenetic features of this patient are very similar to those observed in the five other patients with t(11;18) reported to date. This translocation therefore seems to delineate a new subtype of diffuse small B-cell lymphoma with involvement of mucosal sites. Involvement of the BCL2 oncogene on 18q21 could not be detected using molecular techniques with 5' as well as 3' BCL2 probes, indicating that other, so far unknown, genes relevant to lymphoid differentiation could be located in 18q21 and 11q21.

Antigens, CD↗

Expanded range of 11q13 breakpoints with differing patterns of cyclin D1 expression in B-cell malignancies.

We have analyzed the BCL1 locus in a series of 24 B-cell tumors and cell lines with rearrangements of 11q13 (mostly t(11;14)(q13;q32) translocations). Using Southern hybridization and/or fluorescence in situ hybridization (FISH) on metaphase chromosomes, we have not only confirmed the scattering of the breakpoints between the BCL1 locus and the cyclin D1 gene (CCND1), but also shown that some of the breakpoints could be as far as 500 kb on either side of the latter. Expression of CCND1 was not restricted to cases with t(11;14)(q13;q32), but was also associated with other 11q13 rearrangements, such as a t(8;11)(p22;q13). Whatever the alteration at 11q13, a correlation was observed between the expression of CCND1 and the presence of a breakpoint within 150 kb upstream of the gene. On the contrary, three samples, including a bona fide t(11;14) translocation and two cases with breakpoints located outside the BCL1-CCND1 area, did not exhibit detectable levels of CCND1 transcripts. Our results raise the possibility that several discrete molecular events can take place at 11q13 in B-cell malignancies.

Base Sequence↗

[The effects of Arnica Montana on blood coagulation. Randomized controlled trial].

The purpose of this study, which took the form of a two-period cross-over clinical trial, was to determine whether a homeopathic substance, Arnica Montana, significantly decreased bleeding time (Simplate II) and to describe its impact on various blood coagulation tests. It was not shown that this substance had a significant impact on various parameters of blood coagulation in healthy volunteers in the period immediately following administration [corrected].

Adult↗