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Biomedical subjects

M Andreeff

Publications and source records attributed to M Andreeff.

At least 271 records · Page 15Linked to original sources
PubMed1981

Characterization of cultured human tumor cell lines by flow cytometry DNA stemline.

The DNA stemlines for 12 human tumor cell lines were determined by flow cytometry, and the determinations were compared with other methods available for characterizing cultured cells. In four of ten cases where karyotyping had been done, there was a reasonably good correlation between DNA and karyotype stemlines, but in six cases they differed. Two distinct stemlines were present in two cases. The measurements by flow cytometry can be carried out rapidly and easily and may be useful indicators of extraneous cell contamination or a special clone-derived cell population that has developed during culture passage. In addition, information is provided on the cell cycle distribution. It is proposed that flow cytometry determinations of the DNA stemline be used to help characterize cultured cell lines and to ensure their identity.

Cell Cycle↗
PubMed1980

Childhood CML in blastic stage: an analysis of cell markers and cell kinetics.

The clinical course of Ph+CML and their terminal blastic stage is described in the following case histories. During blastic phase, cell surface markers, terminal deoxynucleotidyl transferase (TdT) activity, and flow cytometric measurements were used or determination of the blast cell phenotype which was undifferentiated by morphological and cytochemical criteria. A high proportion of blast cells expressed Fc receptors for IgG, TdT activity was normal in both children and RNA measurements of single cells flow cytometry showed a high RNA content in the majority of blasts. These findings are compatible with the phenotype seen in the myelomonocytic leukemias. Flow cytometry appears to be a useful adjunct to immunological methods and TdT activity for the rapid characterization of CML in blastic phase.

Child↗
PubMed1980

Heterogeneity of cell lineages in L3 leukemias.

Five cases of adult leukemia with L3 morphology in bone marrow were studied for the presence of immunologic, metabolic, and enzymatic markers. Among the five patients, there were four males and female. Median age was 66 with a range of 16-80 yr. Median survival was only 5 mo. Serum lactate dehydrogenase (LDH) levels, 3H-thymidine labeling indices, and DNA/RNA content of the L3 lymphoblasts were markedly elevated. B-cell markers were found in three cases, two exhibiting surface membrane IgM-lambda, and one IgG-K. Terminal deoxynucleotidyl transferase (TdT) enzymatic activity was consistently low in this group. In one case, the L3 lymphoblasts displayed only surface Fc receptors demonstrated by the binding of aggregated IgG. TdT activity was found to be significantly increased. In another instance, the lymphoblasts formed spontaneous rosettes with sheep erythrocytes and exhibited paranuclear staining with acid phosphatase. TdT activity was found to be low. Although most of the L3 leukemias are neoplasias of B lymphocytes, other lineages may also express this morphology.

Adult↗
PubMed1980

Discrimination of human leukemia subtypes by flow cytometric analysis of cellular DNA and RNA.

A newly developed flow cytometry technique for simultaneous measurements of three features of individual cells--DNA, RNA, and nuclear diameter--using acridine orange as a fluorescent metachromatic dye, has been applied to cell-cycle analysis. DNA stemline determination, and to classification of 102 cases of human leukemias in adults. Acute lymphoblastic leukemia (L1-2) was characterized by moderately increased RNA of G0/1 cells as compared to normal lymphocytes; acute nonlymphoblastic leukemia (M 1-5) by very high RNA of G0/G1 cells. Both had either diploid or aneuploid DNA stemlines. Chronic lymphocytic leukemia showed diploid DNA, very low proliferation, and low RNA, similar to that found by use to be typical for normal B cells. In chronic myelogenous leukemia, two cell populations were distinguished, one with high RNA, the other with very low RNA and elongated nuclear diameter due to stripped, unfolded nuclei of polymorphonuclear leukocytes. The number of leukemic blast cells, identified by aneuploid DNA values, correlates well with conventional microscopy counts and could be followed during the course of treatment. Thus, acridine orange flow cytometry can be used to discriminate subtypes of human leukemias, to determine cell cycle stages, and to detect and monitor aneuploid leukemia stemlines.

Blood Cell Count↗
PubMed1980

Characterization of hematologic malignancies by flow cytometry.

Flow cytometry of cellular DNA content revealed ploidy abnormalities in 15% of 170 patients with various leukemias, in 50% of 26 patients with malignant lymphomas, and in 68% of 110 patients with multiple myeloma, for an overall incidence of DNA content abnormality of 37% in 306 patients with hematologic malignancies. Since the incidence of ploidy abnormality in over 100 solid tumors exceeded 90%. DNA flow cytometry is also ideally suited to screen for bone marrow metastases. Cell separation by centrifugal elutriation was shown to permit enrichment of aneuploid cells, including one example where cells with abnormal DNA content were not recognized in the unfractionated sample. Biparametric measurements of acridine orange-stained cells for DNA and RNA content analysis were suitable to enhance the discriminatory power of flow cytometric detection of lymphoma and myeloma tumor cells in heterogeneous cell populations of bone marrow and lymph nodes. DNA/RNA measurements in leukemia, (the disease category with the lowest incidence of abnormal DNA mode) revealed a markedly higher mean RNA content in acute myeloid leukemia compared with normal or acute lymphoblastic leukemia bone marrow. While these different RNA content patterns were found in whole marrow, cell separation by centrifugal elutriation of normal marrow disclosed cell subpopulations of myeloid precursor cells with a RNA content pattern similar to that of unseparated AML marrow. Hence, the described differences in RNA content between normal and AML marrow seem to be related to the greater heterogeneity of differentiated cells in normal marrow and per se do not appear to be a unique feature of the leukemia disease process.

Bone Marrow↗
PubMed1979

Different sensitivity of chromatin to acid denaturation in quiescent and cycling cells as revealed by flow cytometry.

The properties of DNA in situ as reflected by its staining with acridine orange are different in quiescent nonstimulated lymphocytes as compared with interphase lymphocytes that have entered the cell cycle after stimulation by mitogens. The difference is seen after cell treatment with buffers at pH 1.5 (1.3-1.9 range) followed by staining with acridine orange at pH 2.6 (2.3-2.9). Under these conditions the red metachromatic fluorescence of the acridine orange-DNA complex is higher in quiescent cells than in the cycling lymphocytes while the orthochromatic green fluorescence is higher in the cycling, interphase cells. The results suggest that DNA in condensed chromatin of quiescent lymphocytes (as in metaphase chromosomes) is more sensitive to acid-denaturation than DNA in dispersed chromatin of the cycling interphase cells. The phenomenon is used for flow cytometric differentiation between G0 and G1 cells and between G2 and M cells. In contrast to normal lymphocytes the method applied to neoplastic cells indicates the presence of cell subpopulations with condensed chromatin but with DNA content characteristic not only of G1 but also of S and G2 cells. The possibility that these cells represent quiescent (resting) subpopulations, arrested in G1, S and/or G2, is discussed.

Cell Cycle↗
PubMed1979

The coexistence of acute myeloblastic leukemia and diffuse histiocytic lymphoma in the same patient as demonstrated by multiparameter analysis.

Measurement of cellular DNA content by flow cytometry demonstrated presence of two distinct aneuploid neoplasms in a patient who developed acute myeloblastic leukemia (AML) 4 mo after diagnosis of a diffuse histiocytic lymphoma (DHL). A lymph node aspirate contained peroxidase-negative, "null," hyperdiploid (2.6C) DHL cells, while the bone marrow (BM) contained 84% primitive peroxidase-positive tetraploid AML cells (4.0C). Minor populations of hyperdiploid HDL and normal diploid cells could be detected by flow-cytometry in the BM, and all three populations were also seen in the peripheral blood.

Adult↗
PubMed1978

RNA content in human lymphocyte subpopulations.

Human peripheral blood lymphocytes are stained with the metachromatic dye acridine orange and the fluorescence of individual cells is measured by flow cytometry. The relative content of stainable RNA per cell is estimated by comparison with RNase-treated cells. Non-T and T lymphocytes have different mean quantities of RNA per cell, and these classes exhibit different distributions of RNA content. Non-T cells have a unimodal distribution with a sharp peak and exponential distribution towards higher RNA values. T cells have a bimodal distribution with two separate peaks. When T cells having receptors for IgG (Tgamma cells) and IgM (Tmu cells) are separated, each of these cell populations displays a unimodal distribution. Of these three lymphocyte subpopulations, Tgamma cells have the lowest content of RNA per cell. Non-T cells have slightly higher RNA content than Tgamma, and Tmu cells have twice as much RNA as Tgamma cells. The RNA content, which surely relates to the different functions of these lymphocyte subpopulations, may also be a useful marker for rapidly distinguishing the lymphocyte subpopulations.

Acridines↗
PubMed1975

[Diastolic murmur caused by a phaeochromocytoma (author's transl)].

A protodiastolic murmur was noted in a 24-year-old man with phaeochromocytoma, the murmur disappearing three months after tumour resection. It was probably the result of pulmonary regurgitation, caused by reversible changes in the pulmonary vascular bed or pulmonary valve from the increased catecholamine production.

Adrenal Gland Neoplasms↗