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Biomedical subjects

H Ben-Bassat

Publications and source records attributed to H Ben-Bassat.

At least 73 records · Page 4Linked to original sources
PubMed1982

Establishment and characterization of a new permanent cell line (GDM-1) from a patient with myelomonoblastic leukemia.

The GDM-1 permanent cell line was established from the peripheral blood of a patient with a Philadelphia chromosome negative myeloproliferative disorder, after transformation to acute myelomonoblastic leukemia. The GDM-1 cells exhibited the same characteristics as those isolated from the peripheral blood of the patient prior to death: cells contained non-specific esterase sensitive to fluoride, myeloperoxidase, lysozyme (muramidase), and exhibited both Fc and complement (C3) receptors but lacked B- and T-cell surface markers including T-associated antigens. E-rosetting capacity, surface and intracytoplasmic immunoglobulins and EBV determined nuclear antigen (EBNA). The GDM-1 cells bore the 1a receptor and the myeloid leukemia antigen (M-1). The karyotype of the cultured leukemic cells showed the same specific chromosomal abnormalities present in the monoblasts obtained from the peripheral blood prior to death, indicating that the cell line was derived from the original leukemic cells.

Aged↗
PubMed1982

Induction of Epstein-Barr virus nuclear antigen and DNA synthesis in a human epithelial cell line after Epstein-Barr virus infection.

The association of Epstein-Barr virus (EBV) with nasopharyngeal carcinoma is supported by the presence of EBV genomes in the epithelial elements of the tumor and by elevated antibody titers to EBV-specific antigens in the patients; the levels of these titers are related to the clinical course of the disease. However, since most laboratory data suggest that EBV is a B-lymphotropic virus, it is unclear how the virus becomes associated with the epithelial elements of the nasopharynx. The purpose of the present work was to find a human model system to study this association. A human epithelial line (U) was found that could be directly infected by EBV, and viral functions, the induction of EBV nuclear antigen and cellular DNA synthesis, were demonstrated. The U line was established in 1957 by the late H. J. Van Kooten (Kok-Doorschodt at the University of Utrecht), and although it is no longer diploid, it exhibits density inhibition. When U cells were infected with EBV, EBV nuclear antigen was expressed in 6 to 16% of the cells, 1 and 2 days after infection with B95-8 virus, but not with the P3HR-1 strain. No evidence for virus replication was obtained; immunofluorescence staining for early antigens and virus capsid antigens gave negative results. Quantitative adsorption experiments for EBV indicated that the adsorption capacity of U cells is significant (60% of Raji cells). The present results also demonstrated that infection with the virus overcomes block(s) in cellular DNA synthesis caused by 5-fluorodeoxyuridine. The induction of DNA synthesis was determined by increased incorporation of [3H]thymidine into the cells. The highest level of isotope incorporation was observed at about 15 h after infection and thereafter decreased. Analysis of the induced DNA indicated that it was of cellular origin.

Antigens, Nuclear↗
PubMed1982

Actin, myosin and actin-binding protein in lymphoid cells from human normal and leukemic cell lines.

Actin, myosin and actin-binding protein have been identified in lymphoid cell lines of Null, B or T type of normal and malignant origin. The cells were fractionated into cytosol (Fraction 1), high KC1 extract (Fraction 2) and mainly membrane (Fraction 3). The distribution of the three contractile proteins and the ATPase activities of myosin and actomyosin in B lymphoblastoid normal and B-lymphoma malignant cell lines. Actomyosin-ATPase activity in the normal B line was much higher than it was in the Null B or T malignant lines examined. These results agree with the assumption that malignant transformation is accompanied by an impairment of the action of contractile proteins that leads to a decrease in motility.

Actins↗
PubMed1982

Altered function and membrane properties of lymphocytic leukemia cells. Correlation with clinical stage of disease.

Lymphocytes from the peripheral blood of patients with chronic lymphocytic leukemia (CLL) were examined for the presence of several recognized surface receptors [immunoglobulins, C3 component of complement, and concanavalin A (Con A)] and for structural changes in membrane distribution and dynamics, such as mobility and capping. There appeared to be a general decrease in the mobility of the various receptors on the surface membranes of CLL cells as compared with normal lymphocytes. Although C3 receptors were present on the majority of CLL cells, only a small proportion of the cells formed EAC rosettes. The response to phytohemagglutinin (PHA), Con A and pokeweed mitogen (PWM) confirmed previous observations that CLL cells respond poorly to the B cell mitogen, PWM, and that this response is significantly lower than that to the T cell mitogens, PHA and Con A. The decrease in response to all three mitogens seemed to correlate with the clinical stage of the disease, and it appears that Stage II cases may constitute a heterogeneous group of patients in this respect. A differential response to reduced concentrations of PHA was observed in CLL lymphocytes, but not with normal cells. The data concerning B and T cell function in CLL cells, as determined by the transformation and rosetting capacity of these cells, suggest a general decrease in function, which apparently deteriorates with progression of the disease.

Cell Membrane↗
PubMed1981

Initiation points for cellular deoxyribonucleic acid replication in human lymphoid cells converted by Epstein-Barr virus.

Replicon size was estimated in two Epstein-Barr virus (EBV)-negative human lymphoma lines, BJAB and Ramos, and four EBV-positive lines derived from the former ones by infection (conversion) with two viral strains, B95-8 and P3HR-1. Logarithmic cultures were pulse-labeled with [3H]thymidine, and the deoxyribonucleic acid was spread on microscopic slides and autoradiographed by the method of Huberman and Riggs. After developing, replication forks were visualized as silver grain tracks on the autoradiograms. Average replicon size was estimated by scoring the number of replication forks per constant length of deoxyribonucleic acid and by measuring distances between centers of adjacent tracks, followed by detailed statistical analyses. Three of the four EBV-converted cell lines, BJAB/B95-8, Ra/B95-8, and Ra/HRIK, were found to have significantly shorter replicons (41, 21, 54% shorter, respectively), i.e., more initiation points, than their EBV-negative parents. BJAB/HRIK had replicons which were only slightly shorter (11%) than those of BJAB. However, analysis of track length demonstrated that extensive track fusion occurred during the labeling of BJAB/ HRIK, implying that its true average replicon size is shorter than the observed value. The results indicate that in analogy to simian virus 40, EBV activates new initiation points for cellular DNA replication in EBV-transformed cells.

Autoradiography↗
PubMed1981

Interaction of Herpes simplex virus with human cell lines at various stages of lymphoid differentiation.

The growth of herpes simplex virus (HSV) type 1 in human lymphoid cell lines, arrested at various stages of differentiation, was studied. The synthesis of viral DNA and antigens and the production of infectious virus were followed in null, B and T leukemia-lymphoma cell lines. It was found that while "nondifferentiated" null cells and cells differentiating along the B pathway, even at very early stages of differentiation, supported HSV growth, cell lines of T origin at all stages of differentiation were generally nonpermissive. The failure of T cells to support the growth of HSV did not result from inefficient adsorption to the host cells. However, viral DNA synthesis was not detected, and a significant reduction in the ability of synthesize HSV antigens was observed. It is suggested that the block in the growth cycle of the virus occurs at a stage after adsorption of the virion to the cells, but prior to synthesis of its DNA and proteins.

B-Lymphocytes↗
PubMed1981

Use of multiparameter studies and scanning electron microscopy in the interpretation and attempted correlation of surface morphology with cell type in 135 cases of human leukemias.

Multiparameter studies and scanning electron microscopy (SEM) were performed on cells obtained from 135 cases of leukemia in an attempt to clarify whether there was a reliable correlation between surface morphology and cell type as defined by cytochemistry, membrane markers, and transmission electron microscopy. These studies also attempted to determine whether SEM could be used to distinguish lymphoid and nonlymphoid leukemias, to recognize different types of lymphoid leukemia, and to define the cell type involved in cases of unclassified leukemia. The results of this study suggest that there is a good correlation between surface morphology as seen by SEM and cell type identified by multiparameter techniques. In most cases, nonlymphoid leukemic cells could be distinguished from lymphoid leukemic cells on the basis of their surface morphology. SEM did not appear to contribute to the diagnosis of unclassified leukemia, but more cases of this nature must be studied. Despite the fact that acute lymphoblastic leukemia cells frequently showed fewer microvilli than did other lymphoid leukemias, overlap of surface features in about one-third of the cases did not enable SEM to be used as a reliable means of distinction. The above conclusions appear to be supported by preliminary scanning immunoelectron microscopic observations on leukemic cells. It is concluded that SEM is a useful aid to other modes of microscopy in leukemia but should not be used on its own to establish diagnosis.

Cell Membrane↗
PubMed1980

Burkitt's lymphoma presenting as acute leukemia (Burkitt's lymphoma cell leukemia): report of two cases in Israel.

Two rare cases of Burkitt's lymphoma presenting as acute leukemia are described. Both patients had typical features of Burkitt's lymphoma with rapidly growing, extranodal tumor masses which were multifocal. The blasts infiltrating the bone marrow and peripheral blood showed cytologic, cytochemical, immunologic, and ultrastructural features of Burkitt's tumor cells. The cells had B-cell markers but lacked the EBV-DNA genome and had multiple microvilli as seen by means of scanning electron microscopy. In both cases, the disease was resistant to chemotherapy and rapidly fatal, despite the fact that complete remissions of short duration was obtained.

Adolescent↗
PubMed1980

Establishment in continuous culture of a T-lymphoid cell line (HD-Mar) from a patient with Hodgkin's lymphoma.

A new cell line, HD-Mar, was established from a pleural effusion of a patient with Hodgkin's lymphoma. Formation of E rosettes, sensitivity to anti-T serum, elevated terminal deoxynucleotidyl transferase activity, presence of T-cell and the common ALL membrane antigens, morphology, and cytochemical staining indicate that the HD-Mar line is of thymic derivation. Absence of any immunoglobulin determinants, the lack of EBNA or any other EBV-associated antigen or function are also characteristics associated with established T-cell-derived lymphoma cell lines. Karyotype analysis indicated a tetraploid origin of the cell line.

Adult↗
PubMed1979

Ataxia telangiectasia: chromosomal stability in continuous lymphoblastoid cell lines.

Chromosomal breakage in peripheral lymphocytes, cultured fibroblasts and long-term lymphoblastoid cell lines was investigated in five hitherto undescribed patients with ataxia telangiectasia (AT). Increased chromosomal instability was observed in lymphocytes and fibroblasts, and clones possessing a Dq+ marker were observed. Breakage rates were significantly higher in the fibroblasts than in the lymphocytes of AT patients or in similar tissues from patients with Bloom syndrome or Fanconi anemia. However, chromosome breakage in lymphoblastoid lines established from these five AT patients and six others did not differ from controls. These observations suggests that selection pressures, in vivo or in vitro, or both, act differently on the expression of chromosomal instability in these various cell types.

Abnormalities, Multiple↗
PubMed1979

Surface charge characteristics of cells from malignant cell lines and normal cell lines of the human hematopoietic system.

Cells from malignant and normal lines of human hematopoietic origin were studied for their surface charge characteristics with the use of the following criteria: 1) the electron microscopic appearance of cell membranes after labeling with cationized ferritin (CF) either before or after glutaraldehyde fixation, 2) electrophoretic mobility, 3) total sialic acid content, and 4) agglutinability with poly-L-lysine (PLL). CF induced a time-dependent redistribution of surface receptors in unfixed malignant cells but not in unfixed normal cells. After 10 seconds of labeling with CF, both normal and malignant unfixed cells showed a uniform and even labeling pattern. After 5 minutes of labeling, malignant cells exhibited a highly pronounced pattern of clusters and patches, as distinct from a random and even pattern exhibited by normal cells. Both normal and malignant cells after fixation exhibited an equivalent random and even labeling pattern with CF, independent of the duration of labeling. The malignant cells studied possessed less sialic acid, had a lower electric mobility, and were agglutinated more readily with PLL than were the normal cells.

B-Lymphocytes↗
PubMed1978

Concanavalin A receptors on the surface membrane of lymphocytes from patients with Burkitt's lymphoma, other malignant lymphomas, leukaemia and lymphoma cell lines.

Lymphocytes isolated from the peripheral blood and tumour tissues of patients with African Burkitt's lymphoma (BL) showed a reduced cap-forming ability and increased agglutinability by concanavalin A (con A) compared to normal lymphocytes. Lymphocytes from the blood of patients with chronic lymphocytic leukaemia, Hodgkin's disease and other malignant lymphomas showed a similar reduction in cap formation and increase in agglutination compared to normal lymphocytes, lymphocytes from patients with carcinoma, and lymphocytes from patients with non-malignant disorders. The cap formation of lymphocytes from a healthy donor or a lymphoma patient was independent of the source from which the cells were isolated, e.g., lymph-node, spleen or blood. Lymphoma cell lines established from tumours of BL patients and lymphoblastoid cell lines originating from other sources also exhibited an increased agglutination and reduced cap formation with con A. Further studies indicated that EBV-carrying human lymphoid lines had a reduced cap-forming ability compared to EBV-negative lines.

Burkitt Lymphoma↗
PubMed1977

Establishment in continuous culture of a new type of lymphocyte from a "Burkitt like" malignant lymphoma (line D.G.-75).

The isolation and establishment in vitro of a hitherto undescribed type of lymphocyte designated D.G.-75 is reported. The original inoculum was derived from the pleural effusion of a child with a primary abdominal lymphoma, which clinically and histologically resembled Burkitt's lymphoma. In addition to the absence of the EBV genome and EBV receptors, this line possesses a number of other properties which distinguish it from previously described lymphoblastoid cell lines. It has different growth characteristics and morphology; does not form EAC or E rosettes (representative of B and T) cell surface markers, respectively); possesses IgM-kappa immunoglobulins on the cell surface (B lymphocyte), has an unusually high cap-forming ability and low agglutinability with fluorescent concanavalin A. One homologue of the No.14 chromosome pair possesses extra chromatin material as revealed on chromosome banding. This abnormal chromosome marker is similar to that described in biopsies and cultured tumor cells from patients with African Burkitt's lymphoma.

Agglutination Tests↗