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F Valensi

Publications and source records attributed to F Valensi.

At least 73 records · Page 4Linked to original sources
PubMed1993

[The progresses in the determination of blood monocytosis and its perspectives of clinical application in pathology].

Automated cell counters have allowed the reproducible analysis of the 5 leucocyte populations (neutrophils, eosinophils, basophils, lymphocytes and monocytes). Determination of the monocyte count by classical microscopic analysis can be inaccurate. We have compared the automated monocyte count from the coulter STKS (program 1F) with counts obtained by microscopic analysis of 1000 leucocytes and by flow cytometric analysis of cells stained simultaneously with a pan-leucocyte and a monocyte-specific antibody. The values provided by the coulter STKS are sufficiently precise to recommend the routine clinical use of this automated counter.

Female↗
PubMed1992

Specific polypeptide markers in chronic B cell malignancies detected by two-dimensional gel electrophoresis.

Two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) analysis of silver stained polypeptides was used to discriminate the cell protein profiles in chronic B cell malignancies. We identified 5 distinct polypeptides (H1 to H5) present in hairy cell leukemia (HCL) (14 cases) and absent in most chronic lymphocytic leukemia (CLL) and normal B lymphocytes. Two polypeptides, H2 and H5, were absolutely specific of HCL. The 2-D PAGE profiles found in 3 splenic lymphoma with villous lymphocytes (SLVL) and 2 HCL variants (HCL-V) were similar to HCL with a unique additional peptide present in 3/3 SLVL and 1/2 HCL-V. When HCL and SLVL were assessed for the CLL stage-specific 2-D PAGE patterns, HCL was related to stage A/B while SLVL was related to stage C. In conclusion, 2-D PAGE analysis of the molecular pattern of B lymphocytes provides a new means to recognize the leukemic origin of the sample and distinguish HCL from CLL and SLVL.

Adult↗
PubMed1992

Molecular analysis of 12 patients with the t(8;21) translocation and M2 acute myelogenous leukemia.

The t(8;21)(q22;q22) is a nonrandom cytogenetic abnormality associated with acute myelogenous leukemia of the M2 subtype (FAB classification). The 8q- and 21q+ derivative chromosomes have previously been isolated in somatic cell hybrids and used to map the anonymous sequences D21S65 and D21S17, which were proximal and distal, respectively, to the breakpoint on chromosome 21. DNA from a series of 12 t(8;21) patients and 7 controls was analyzed by pulsed field gel electrophoresis. Physical linkage of probes D21S65 and D21S17 on a 2100 kb NruI fragment was established by partial digestion experiments. In all the patients, the translocation generated a rearranged D21S65 NruI fragment of 650 to 750 kb, suggesting heterogeneity in the breakpoints. This heterogeneity was confirmed by using BssHII, SacII, and EagI enzymes. Our results are consistent with the presence of a 100 Kb breakpoint cluster region on chromosome 21 encompassing the AML1 gene. Interestingly, in half of the patients, demethylation of an NruI site located 7 kb proximal to the last exon of the AML1 gene occurred on the nontranslocated chromosome 21.

Adolescent↗
PubMed1992

A retinoid acid 'resistant' t(15;17) acute promyelocytic leukemia cell line: isolation, morphological, immunological, and molecular features.

We report the isolation of a maturation-resistant acute promyelocytic leukemia (APL) cell line. This permanent cell line, derived from the same patient as the maturation inducible NB4 cell line, is the first retinoid-resistant cell line with a t(15;17) chromosomal translocation. Morphological, immunocytochemical and molecular features of the maturation responsive (NB4) and unresponsive (NB4-RAr) cells are compared. The isolation of the NB4-RAr cell line occurred through a two-step process requiring the continuous selective pressure of all-trans-retinoic acid. Cells are also resistant to 13-cis-retinoic acid. Karyotypic and Southern-blot analyses show that the two cell lines are similar with respect to the translocation. Northern-blot analyses show that the chimeric fusion transcript PML-RAR alpha and the normal allelic PML and RAR alpha transcripts are similarly expressed in both cell lines. The molecular basis for unresponsiveness to retinoic acid is not known. This resistant cell line offers a cellular model for molecular biology studies on the mechanism of induction of APL cell maturation, as well as a means to elucidate the molecular mechanisms of resistance. It also furnishes a unique tool for designing and/or screening new therapeutic drugs to avoid or relieve retinoid maturation blockage.

Adult↗
PubMed1991

The IgM-associated protein mb-1 as a marker of normal and neoplastic B cells.

Recent evidence indicates that the transmembrane form of IgM on murine and human B lymphocytes is physically associated with at least two proteins, forming a disulfide-linked dimer, which may control cell surface expression of IgM and also play a role in signal transduction after Ag binding (by analogy with the TCR-associated CD3 components in T lymphocytes). We have used mAb and polyclonal antibodies against an intracytoplasmic epitope on one of these polypeptides (previously identified in murine B cells as the product of the B cell specific mb-1 gene) to study the distribution of the IgM-associated dimer in human cells. By immunocytochemical staining of normal and neoplastic B cells, we show that the human mb-1 protein appears early in B cell differentiation, probably before expression of cytoplasmic mu-chain, and persists until the plasma cell stage, where it is seen as an intracytoplasmic component. According to immunohistologic analysis of reactive lymphoid tissue and lymphoma samples, mb-1 protein is completely B cell specific. Anti-mb-1 also labels B cell areas in tissues from seven different mammalian species. Finally, the Ig-associated dimer could be isolated from human hairy-cell leukemia cells in high purity and yield by affinity chromatography using anti-mb-1 antibody. Mice immunized with this material have produced a strong polyclonal response, so that it should now be possible to prepare a panel of new mAb reactive with different epitopes on both mb-1 and on its associated polypeptide(s).

Animals↗
PubMed1991

NB4, a maturation inducible cell line with t(15;17) marker isolated from a human acute promyelocytic leukemia (M3).

Acute promyelocytic leukemia (APL) is a well-defined entity among acute leukemia, cytogenetically characterized by a t(15;17) (q22;q11-12) translocation. In vitro and in vivo studies suggest that all-trans retinoic acid (RA) treatment restores cell maturation. We have isolated the first permanent cell line with t(15;17), derived from the marrow of a patient with APL in relapse. The establishment of the cell line, its morphologic, karyotypic, and immunohistochemical features are reported. RA induced cell line maturation. Cells strongly expressed myeloid markers, but also some T-cell markers. Additional karyotypic abnormalities, a 12p rearrangement and the possible presence of a homogeneous staining region (HSR) on 19q+ are discussed both in relation to T-cell (CD2, CD4) and monocyte (CD9) markers, and to the acquired cell growth autonomy. The cell line represents a remarkable tool for biomolecular studies.

Adult↗
PubMed1991

Production of a monoclonal antibody (2B44) reactive on a shared epitope on dendritic reticulum cells, smooth muscle cells of vessels and Reed-Sternberg cells.

Lymph node cells from a patient with Hodgkin's disease (HD) were cultured without Epstein-Barr virus (EBV) or leukine adjuvant. A cell line (719-AB) emerged from the culture after four weeks. The cell line express CD20 (79%), CD 21 (30%), CD30 (63%), CD 35 (61%) antigens and weakly CD25 (19%). using Southern Blot technique, the existence of specific EBV DNA and polyclonal immunoglobulin genes rearrangement were observed in the cell line. In order to obtain a monoclonal antibodies (MoAb), mice Balb/C were immunized with this cell line. The splenic cells suspension of immunized animals were fused with the mouse myeloma NS1. Antibody IgM kappa from secreting clones 2B44 was studied using both indirect immunofluorescence with labeled anti-mouse immunoglobulin and immunohistochemistry based on alkaline phosphatase/antiphosphatase complex (APAAP) and ModAMeX technique on a panel of normal or pathological cells. Normal peripheral lymphocytes, monocytes, polymorphonuclear cells, and erythrocytes, did not react. The MoAb 2B44 recognized the dendritic reticulum cells and the smooth muscle cells of vessels on frozen section and paraffin section from HD or reactive lymph nodes. On specially processed paraffin sections (ModAMeX) Reed-Sternberg cells (RSC) were reactive with 2B44 MoAb (in 2 cases out of 5 tested). The molecular weight of the antigen recognized by 2B44 MoAb is of 37 kd. The description of a new epitope shared by different histological components might be of interest for defining a new cluster and better understanding the nature of RSC.

Antibodies, Monoclonal↗
PubMed1990

Splenic B-cell lymphoma with villous lymphocytes (SLVL). A lymphocytic lymphoma simulating hairy cell leukemia. A study of 8 cases.

Splenic B cell lymphoma with circulating villous lymphocytes (SLVL) is a lymphoproliferative disorder characterized by the presence in the peripheral blood of atypical B-lymphocytes with hairy appearance. Although the clinical features with massive splenomegaly, absence of peripheral lymphadenopathy and blood cytopenia may mimic hairy cell leukemia (HCL), precise analysis of the morphologic and immunologic features allow differential diagnosis between these two entities. Bone marrow and spleen histology resemble the pattern in chronic lymphocytic leukemia (CLL). We studied 8 patients with this entity illustrating the difficulty of diagnosis between SLVL and HCL.

Aged↗
PubMed1990

T cell receptor delta gene rearrangements occur predominantly in immature myeloid leukemias exhibiting lineage promiscuity.

T cell receptor delta (TCR) genes have been recently identified as rearranging during the early stages of T cell differentiation. We have analyzed the configuration of these genes in 47 unselected acute nonlymphoid leukemias. Morphology, phenotype, immunoglobulin heavy chain, and T cell receptor beta and gamma chain gene configuration were also studied. We have documented TCR delta gene rearrangements or deletions in eight cases using a genomic J delta 1 probe. The comparison of morphological, phenotypical, and molecular findings from these cases with those from control acute myeloid leukemias whose TCR delta genes were in germline configuration show that TCR delta rearrangements occur predominantly in immature leukemia exhibiting extensive lineage infidelity. The most striking feature was the frequent expression of the CD10 antigen. These data show that inappropriate gene rearrangements occur nonrandomly in myeloid leukemias and suggest that common mechanisms may be involved in the regulation of gene rearrangements and in the expression of some differentiation antigens.

Adolescent↗
PubMed1990

A new Ph1+, bcr cell line derived from a patient with ALL-L1 gained autonomy in culture concomitant to CD23 expression.

A permanent cell line, LEF1, has been established from the cells of an adult suffering from a Philadelphia positive acute lymphoblastic leukemia. The LEF1 cell line was obtained by maintaining peripheral blood cells from the patient in culture on a fibroblast feeder; subsequently, an autonomously growing cell population, independent of that feeder layer, developed. The karyotype of the cell line, 46, t(9;22)(q34;q11), was different from the karyotype at diagnosis which had 53 chromosomes and two Philadelphia chromosomes. Furthermore, compared with the initial leukemic blasts, the immortalized cell had three differences in surface phenotype (CD23+, CD11b-, CD10-). However, molecular studies indicated that the breakpoint in the 3' part of the first intron of the BCR gene was unchanged, confirming the leukemic origin of LEF1. The cell line was shown to be Epstein-Barr virus negative.

Adult↗
PubMed1989

Subcutaneous eosinophilic necrosis associated with refractory anemia with an excess of myeloblasts.

We followed up over a period of 10 months a Cambodian patient in whom refractory anemia with excess blasts was discovered after the onset of fever and chronic dermatologic involvement. Violaceous, firm, and painful subcutaneous nodules (1-3 cm in diameter) were present on the arms, legs, trunk, scalp, neck, and chin and were associated with violaceous infiltrating plaques on the face and forehead. The microscopic examination of repeated biopsy specimens showed a predominantly lobular panniculitis characterized by an extensive eosinophilic necrosis, leukocytoclasia, and fibrinoid deposits within a few vessels. Such lesions might be the consequence of the immune response against leukemic clones, which have been shown to be present in a steady state in at least some cases involving myelodysplastic syndromes.

Anemia, Refractory, with Excess of Blasts↗
PubMed1989

Are most secondary acute lymphoblastic leukemias mixed acute leukemias?

A case of acute lymphoblastic leukemia (ALL) secondary to X-ray exposure is reported. The lymphoblasts expressed T-cell and myelomonocytic differentiation-related surface antigens. Clonal chromosomal abnormalities including t(2;12)(q25;q13),-10,der(10), del(11)(q14),der(12) and r were observed. A review of the cytogenetic data suggests that most secondary ALLs, with the exception of Burkitt type ALLs, may be biphenotypic or mixed acute leukemias.

Adult↗
PubMed1988

Cytogenetics of T-cell malignant lymphoma. Report of 17 cases and review of the chromosomal breakpoints.

Cytogenetic studies are reported on 17 T-cell malignant lymphomas (ML) including six cutaneous T-cell malignant lymphomas (CTCL). Due to the low incidence of rearrangements on bands where the T-cell receptor genes are located, other cases reported in the literature were analyzed in order to estimate the most frequent chromosomal breakpoints in ML, CTCL, and adult T-cell leukemia-lymphoma. Besides chromosomes 1 and 6q, 14q11, 7p15p21, and 7q32q35, the most frequent rearrangements involved bands 14q32, 2p11-p14, 2p23-p25, 17cen, 9p21p23, and 10p13p15. These results show that molecular studies must be concentrated on these chromosomal regions in order to identify the DNA sequences that may be involved in T-cell malignancies.

Adult↗
PubMed1988

Philadelphia-positive acute leukemia: lineage promiscuity and inconsistently rearranged breakpoint cluster region.

Six patients with Philadelphia-positive (Ph1+) acute nonlymphocytic leukemia (ANLL) were studied by morphological, immunological, cytogenetic, and molecular techniques. Seven Ph1+ acute lymphocytic leukemia (ALL) cases were also studied for comparison. Three of ANLL cases were classified in M1, M2, and M4 groups of the FAB nomenclature, while the three other cases do not fit with any FAB subgroup and are described as M0. Immunophenotypical marker studies, double immunolabeling, and combined immunological and cytogenetic studies of metaphases showed that these ANLL expressed several lineage differentiation antigens. Rearrangements of immunoglobulin heavy chain gene (C mu) were detected in the six ANLL cases and in the seven ALL cases studied, as well as, in most cases, rearrangement of T cell receptor beta chain genes and/or T cell rearranging gamma genes. The results favored the assumption that the Ph1 translocation originated from a multipotent stem cell in Ph1+ ANLL. A common t(9;22) translocation was found in all cases, and additional chromosomal abnormalities were present in the six ANLL cases and in five of the seven ALL cases. Molecular studies of bcr gene configuration and c-abl transcription allowed two groups of Ph1+ ANLL to be distinguished. Three cases had bcr rearrangement and c-abl mRNA expression comparable to those reported in Ph1+ chronic myeloid leukemia, while three others had not detectable bcr rearrangement and a 7.2-7.5 kb c-abl mRNA. The existence of Ph1+ ALL with and without classical bcr rearrangement was confirmed.

Adolescent↗
PubMed1987

Necrobiotic xanthogranuloma with myeloma. A case report.

Necrobiotic xanthogranuloma is a newly recognized cutaneous manifestation associated with paraproteinemia. Necrobiotic xanthogranuloma is distinctive clinically by yellowish-red nodular lesions, often ulcerated, with predilection for the periorbital area and ocular involvement. Histologically, it is characterized by the combination of inflammatory xanthogranulomas together with areas of necrobiosis. These skin lesions are associated with a dysglobulinemia and preceded the development of an IgG lambda myeloma in a previous patient. Hyperlipidemia may be found in some patients. A case of necrobiotic xanthogranuloma is reported, occurring in a 46-year-old man and associated with an IgG kappa myeloma.

Granuloma↗
PubMed1987

Cytogenetic studies on 519 consecutive de novo acute nonlymphocytic leukemias.

Cytogenetic studies were performed in the same laboratory on 519 untreated cases of de novo acute nonlymphocytic leukemia (ANLL) between 1977 and 1985. The overall incidence of clonal chromosome abnormalities was 54.3%; higher in children (67.5%) than in adults (50.4%). The distribution of chromosome abnormalities was uneven, according to the categories of the FAB nomenclature. The highest frequency of chromosome changes was observed in ANLL-M3 and the lowest in M1 and M6. The frequency of specific chromosome abnormalities and of their associated changes were also estimated. Monosomy 7 was detected in three patients with acute megakaryocytic leukemia (M7). Six cases with two abnormal chromosomally unrelated clones were observed and six constitutional chromosome abnormalities were detected. A clearer knowledge of the incidence of various chromosomal changes in ANLL seems necessary for better differentiation between the so-called primary and secondary chromosome abnormalities and for prognostic evaluation.

Acute Disease↗