PubMed Health⌕ Search

Biomedical subjects

F Valensi

Publications and source records attributed to F Valensi.

At least 109 records · Page 6Linked to original sources
PubMed1983

Malignant and reactive erythroblasts in erythroleukemia (M6).

A cytogenetic and cytological study of 16 cases of erythroleukemia (M6) is reported. No chromosomal abnormalities were observed in 10 cases. Abnormalities were present in the other 6 cases, of which 4 were complex abnormalities. It was not possible to establish any correlation between the occurrence of morphologic abnormalities of the erythroid and megakaryocyte-platelet series and the presence of cytogenetic defects. Studies of mitoses by cytologic and cytogenetic methods concurrently performed in some cases suggest that two types of erythroleukemia can be distinguished: (1) cases with chromosomal abnormalities and a persistence of erythroblast mitoses in vitro (which suggests that the erythroblasts belong to the leukemic clone) and (2) cases with no chromosome abnormality and a disappearance of erythroblast mitoses after culture, suggesting that the erythroblasts are not members of the leukemic clone.

Adult↗
PubMed1983

[Prognostic value of chromosome anomalies in acute non-lymphoblastic leukemias].

The results of a cytogenetic study on 240 acute nonlymphocytic leukemia patients (187 adults and 53 children) were classified in NN (normal), AN (abnormal and normal) and AA (abnormal). Pronostic value of the classification was presented. A higher proportion of complete remission failures was observed in chromosomally abnormal patients (AN and AA). Survival of patients with complete remission was significantly shorter in AN and AA patients than in NN patients. An excess of constitutional chromosome abnormalities was observed in children.

Acute Disease↗
PubMed1982

Acute monocytic leukemia chromosome studies.

Cytogenetic studies have been performed on 34 acute monocytic leukemia (M5) patients, 24 of the a type and 10 of the b type. No chromosomal abnormalities were found in 12 cases, in spite of the fact that the mitoses concerned monocytes. Different chromosomal aberrations were present in the other cases. In 12 of them, an abnormality of the chromosome 11 long arm was observed (mainly in the poorly differentiated type of M5), on bands q22-q24 in nine cases and on band q14 in three cases. The chromosome 11 long arm thus appears preferentially rearranged in M5 although this is not apparent in every case. Concomitant study of the mitoses with cytological and cytogenetic techniques suggests that erythroblasts may not be involved in the M5 leukemic process.

Adolescent↗
PubMed1982

Probing human malignant T cells with lectins: a comparison with their surface antigen patterns defined by monoclonal antibodies.

Tumor cells from 40 children and 13 adults with T cell malignancies were assessed for staining with fluorescinated peanut agglutinin (PNA) and soybean agglutinin (SBA). These cell populations had also been characterized for surface surface antigens using a series of monoclonal antibodies (Mo. Ab.) that permit an assignment of malignant cells to discrete stages of normal T cell differentiation. We had previously shown a clear correspondence between lectin- and Mo. Ab-defined cell compartments within thymuses from normal children and T cells in peripheral blood. We report here that the pattern of reactivity of malignant T cells populations with lectins correlates closely the degree of maturation, as assessed by Mo. Ab. Thus, utilization of lectins together with Mo. Ab., can be clinically useful to characterize T cell malignancies. This observation shows that, in spite of a high degree of heterogeneity of malignant T cell populations from one patient to the other, in their pattern of surface antigens, these populations seem essentially to conform to the scheme of normal T cell differentiation.

Antibodies, Monoclonal↗
PubMed1982

Cytologic characterization and significance of normal karyotypes in t(8;21) acute myeloblastic leukemia.

A cytologic and cytogenetic study of 10 cases of acute myeloblastic leukemia with maturation and t(8;21) translocation is reported. Despite a certain polymorphic appearance, the characteristic cytologic picture, consisting essentially of large myeloblasts with an abundant cytoplasma containing a large Auer rod, allowed the presence of the chromosome anomaly to be predicted. t(8;21) translocation was attended by the loss of a sex chromosome in 7 of 10 cases. The comparative study of mitoses using cytologic and cytogenetic techniques showed that cells exhibiting normal karyotypes were essentially erythroblasts. This finding suggests that the chromosome anomaly does not affect all the bone marrow cell lines. After short-term culture, the percentage of normal karyotype mitoses diminished, as did the number of mitoses in erythroblasts.

Adolescent↗
PubMed1981

[Translocation t (8; 21) and acute granulocytic leukemia: interpretation of normal mitoses].

Cytological and cytogenetic studies of nine acute granulocytic leukemia with t (8; 21) translocation were performed from the same bone marrow and blood cell samples. It was shown that the chromosome abnormality was restricted to leukemic cells and that normal metaphases were erythroblast mitoses. Using cell cultures in which only or mainly leukemic cells were able to divide permits easier detection of chromosomal aberrations. These results led us to postulate an inhibitory role of leukemic cells on the division of normal granulocytic cells.

Cell Division↗
PubMed1981

Cell surface characterization of malignant T cells from lymphoblastic lymphoma using monoclonal antibodies: evidence for phenotypic differences between malignant T cells from patients with acute lymphoblastic leukemia and lymphoblastic lymphoma.

A series of monoclonal antibodies was used for the characterization of malignant T cells from 21 patients with lymphoblastic lymphoma (LL). The tumor population from these patients showed a marked degree of phenotypic heterogeneity and a proportion (one-third) of patients had tumor cells that did not conform exactly with the cells normally detected in the thymus. However, these cell populations could be related to the early or common or late thymocyte population (about one-third of the patients in each category). This contrast, with the characterization of malignant T cells from 43 patients with acute lymphoblastic leukemia (ALL) that could be related to either early or common thymocytes, with an exception of two patients categorized as having a tumor population related to late thymocytes. Further phenotypic differences between cells from ALL and LL could be demonstrated by investigation with two additional monoclonal antibodies, A50 and U4. Among patients with malignant T cells related to common thymocyte, 0/12 patients with ALL had cells recognized by A50, where 5/8 patients with LL had A50+ cells. Among patients with early thymocytes, only patients with ALL had cells recognized by U4. In addition, 5 LL patients had cells reactive with J5, a monoclonal antibody recognizing the common ALL antigen (CALLA). Since CALLA was found on cells related to common and late thymocytes, CALLA is neither lineage specific, nor can it be viewed as being peculiar to malignant lymphoid cells arrested at very immature stages of differentiation.

Adolescent↗
PubMed1981

Karyotypes and cell phenotypes in acute leukemia following other diseases.

Acute nonlymphoblastic leukemias following other blood disorders or exposure to possible oncogenic agents were analyzed for cytological and cytogenetical characteristics. "Secondary' acute leukemias (AL) were often found to be unclassifiable in the FAB system. Monosomy 7 was associated with megakaryocytic cell line abnormalities. Variation of cytological and cytogenetical patterns was correlated in the whole sample and in a sample of 10 postpolycythemia vera blood disorders.

Chromosome Aberrations↗
PubMed1981

Surface antigens on malignant Sézary and T-CLL cells correspond to those of mature T cells.

Tumor cells from eight adult patients with T-cell chronic malignancies were investigated with a series of monoclonal antibodies recognizing T-cell differentiation antigens. This series allowed definition of discrete subpopulations of mature T cells with functional specialization. All six patients with Sézary syndrome and one patient with T-chronic lymphocytic leukemia had cells with the same phenotype as normal helper/inducer T cells, whereas the other patient with T-chronic lymphocytic leukemia had cell with the same phenotype as normal cytotoxic/suppressor T cells. Some clinical manifestations observed in these patients may reflect retention of functional activities by their malignant cells.

Antibody Specificity↗
PubMed1981

Karyotype and cell phenotypes in primary acute leukemias.

This paper reviews the chromosomal and cytological patterns in acute leukemias (AL) and attempts to establish a correlation with the FAB classification. In fact, these studies are useful in distinguishing different forms of AL and in understanding the nature of the cell from which the malignant clone originated. As shown by the results obtained from the study of acute promyelocytic leukemia, for instance, these studies also provide a likely explanation for the lack of chromosome abnormalities in certain cases of AL.

Acute Disease↗
PubMed1981

[Induced leukemias. Cytogenetical and cytological aspects. Comparison with primitive leukemias (author's transl)].

25 presumably induced leukemias, either following treatment (lymphoma, polycythemia vera, essential thrombocythemia, cancers) or after exposure to oncogenic agents have been studied cytogenetically and cytologically. Complex chromosomal abnormalities were associated with a difficult cytological classification. Complete monosomy 7 with presence of micromegacaryocytes and macroplatelets was observed in 7 cases. The findings observed in induced leukemias were compared with those found in "primitive" leukemias showing the same chromosomal patterns. The same relationships between cytology and cytogenetics have been observed.

Adult↗
PubMed1980

Functional study and detection of HLA-D products on fractionated human bone marrow cells.

Bone marrow cells from nine normal human volunteers obtained from the Iliac crest, were used in this work for antigen determination and functional studies. The bone marrow aspirated cells were sequentially separated: elimination of erythrocyte, granulocytes and monocytes achieved by Ficoll-Isopaque centrifugation followed by plastic adherence. Purified bone marrow cells were finally separated by size using velocity sedimentation. The slow sedimenting small cells were shown to be mainly T lymphocytes, probably of blood origin. The medium sized bone marrow cells were shown to contain myeloid precursors (CFu-c). Large immature cells were in cycle actively synthesizing DNA molecules. HLA-D and HLA-DR detections on the fractionated cells were performed using three techniques: fluorescence with specific anti HLA-DR allo and xeno antisera; primed lymphocyte typing (PLT) with anti HLA-DR monospecific in vitro primed lymphocytes and detection of the HLA-D stimulating product using the bone marrow fractionated cells as stimulators in a mixed leukocyte culture. Concordant results were obtained with the three techniques. Lymphocytes in the bone marrow express HLA-D products a peripheral lymphocytes. Bone marrow fractions depleted of lymphocytes and monocytes also contain approximately 20% of cells expressing HLA-D products The meaning of the expression of HLA-D products on immature precursors non-lymphoid cells is discussed.

Bone Marrow Cells↗
PubMed1979

[A new variety of acute non-promyelocytic leukemia with t(15;17)].

Three cases of a new variety of acute leukemia have been reported. The main features were: hyperleukocytosis made of large-sized blasts with a double shaped nucleus, few or no granulations in the cytoplasm, and in a few cell faggots or unique Auer rods; mycloperoxydase reaction was positive. This feature was associated with disseminated intravascular coagulation syndrome and t(15;17)(q22;q21) translocation in the majority of mitoses.

Acute Disease↗
PubMed1979

Acute lymphoblastic leukemia with pre-B-cell characteristics.

Blast cells from 6 of 50 patients with acute lymphoblastic leukemia (ALL) displayed intracytoplasmic mu chains in the absence of detectable light chains and surface immunoglobulins. These cells also expressed lalike and common ALL antigens. Terminal deoxynucleotidyltransferase was detectable in 2 of 5 cases tested. These blast cells are probably related to early B-cell precursors (pre-B cells). In 4 of 6 cases the disease had a tumoral presentation; the prognostic significance of this new subgroup, which accounts for 20% of patients with non-T non-B ALL, remains to be established.

Antigens, Neoplasm↗
PubMed1979

[T (15;17) translocation in acute promyelocytic and acute nonpromyelocytic leukemia (author's transl)].

Seven acute promyelocytic leukemias (APL) were compared with three atypical acute myeloblastic leukemias (AML). These three AML were characterized by high hyperleukocytosis, mostly formed of monocytelike myeloblasts, disseminated intravascular coagulation syndrome, and a t (15;17) translocation in the majority of leukemic cell mitoses. This translocation was inconsistently found in typical APL defined as M3, according to the FAB classification.

Adolescent↗
PubMed1978

[Use of the LARC system in a laboratory specializing in hematology (author's transl)].

Two thousand consecutive white blood cell counts were simultaneously studied by the LARC system and the traditional manual method. This comparison enables the following four couclusions to be drawn.--The reproducibility of the LARC differential is superior to the traditional method;--The similarity between results obtained by the LARC and the manual method are good, as indicated by scatter-plots and calculated correlation coefficients;--The LARC system can be substituted for the traditional manual method, also for markedly pathologic samples, but in this case at the price of a slowing down of the through-put rate of the system;--The detection of abnormal white cell types is as good or better with the LARC system as compared with the manual method.

Autoanalysis↗