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Biomedical subjects

A Karpas

Publications and source records attributed to A Karpas.

At least 91 records · Page 5Linked to original sources
PubMed1980

Dissociation of opsonized particle phagocytosis and respiratory burst activity in an Epstein-Barr virus-infected myeloid cell line.

A continuous tissue culture cell line (Karpas line 120), derived from a patient with acute myeloblastic leukemia, not only demonstrates myeloblastic morphology and in vitro expression of several myeloid-specific biochemical markers but also contains Epstein-Barr virus (EBV) nuclear antigen. The present studies demonstrate EBV-genome-specific DNA within the total cellular DNA by molecular hybridization, thus establishing the presence of stable viral genome integration. The cells demonstrate complex coordinated myeloid functions including ingestion, degranulation, and respiratory burst activity. Line 120 cells show a respiratory burst (superoxide and hydrogen peroxide generation and hexosemonophosphate shunt activity) in response to soluble (phorbol myristate acetate) and particulate (latex beads) stimuli, as do normal granulocytes. They ingest complement-opsonized particles (lipopolysaccharide-oil droplets, zymosan, and bacteria), and degranulate in response to them. However, unlike normal granulocytes, the line 120 cells do not demonstrate respiratory burst activity in response to these complementopsonized particles. The dissociation between ingestion of complement-opsonized particles and activation of oxygen-dependent bactericidal activity severely impairs bacterial killing as compared with normal polymorphonuclear phagocytes.

Animals↗
PubMed1980

Phenotypic characterization of a virus producing line established from a patient with leukaemia/lymphoma: comparison with T-lymphoblastic and myeloblastic lines.

The properties have been studied of a haemic cell line established from a patient with longstanding non-Hodgkin's lymphoma after transformation to acute leukaemia. The cells are EBNA, Fc, C3 and SmIg and Ia-like antigen negative. The continuous in vitro proliferation and karyotype abnormalities suggest malignancy. The cells contain only the lymphoid type of alkaline phosphatase and a high level of terminal deoxynucleotidyl transferase and as they formed E-rosettes during the first year in culture they may be of T-cell lineage. Since the patients' leukaemic cells have not been studied it is impossible to know whether the cultured cells represent an in vitro proliferation of the patient's malignant cells or an outgrowth of a subpopulation of cells. In the cytoplasm of many cells inclusion bodies containing virus-like particles, similar to those observed in fresh human leukaemia cells, were often seen. As this new virus is biologically active, infection of the cells by virus may explain their continuous proliferation in vitro.

Adult↗
PubMed1980

Characteristics of a cell line established from a child with familial acute myeloid leukaemia.

The properties of an unusual new cell line from a child with acute myeloid leukaemia (AML) is described. The patient, his mother and grandmother all died within 2 years of AML. Karyotypic analysis suggests that the cells which grow in vitro represent a proliferation of the child's leukaemic cells. The presence of myeloid alkaline phosphatase in these cells suggests that they represent a proliferation of malignant myeloblasts. During the first year in culture a significant percentage of the cells formed E-rosettes, but the cells failed to react with monoclonal anti-T-cell antibodies. The cells are SmIg, Fc, C3 and EBNA negative. Ultrastructural examination of the cells revealed cytoplasmic inclusion bodies which contained virus-like particles. These inclusion bodies and particles were similar to those observed by us in two other human leukaemic cell lines and not unlike those in fresh human leukaemic cells, as reported by others.

Alkaline Phosphatase↗
PubMed1980

Sinus histiocytosis with massive lymphadenopathy: virological, immunological and morphological studies.

The histiocytes from a patient with sinus histiocytosis were tested for the presence of Epstein-Barr viral nuclear antigen (EBNA) before and after in vitro growth. On both occasions the histiocytes as well as the lymphocytes were EBNA negative. Likewise the profile of EBV viral capsid antibody (VCA) suggests that this virus is unlikely to be directly involved in the development of the disease. The maintenance of an unusually high level of antibodies to EBV and measles, both viruses which produce persistent infections, indicates that the humoral immune response is active. That a normal humoral response occurred in response to mumps virus during the same period suggests that a deficiency in the cell mediated immune response to the persistent viruses might be the reason for the abnormally high antibody levels. The fresh as well as the cultured histiocytes had only Fc receptors. The affected lymph node lymphocytes developed unusual large inclusion bodies following in vitro culture.

Adolescent↗
PubMed1978

Alkaline phosphatase in Epstein-Barr viral nuclear antigen--positive cell lines.

The production and nature of alkaline phosphatase were studied in Epstein-Barr viral nuclear antigen-positive, surface membrane immunoglobulin negative-cell lines established from two patients, one with acute myeloid leukemia and one with acute lymphoblastic leukemia. The acute myeloid leukemia-derived cells contained myeloid alkaline phosphatase, while the acute lymphoblastic leukemia-derived cells contained lymphoid alkaline phosphatase. The presence of the myeloid-specific enzyme in a surface membrane immunoglobin--negative cell line suggests that the line is composed of myeloid precursor cells and that such cells may be susceptible to infection with Epstein-Barr virus.

Alkaline Phosphatase↗
PubMed1978

Constitutive and inducible granulocyte-macrophage functions in mouse, rat, and human myeloid leukemia-derived continuous tissue culture lines.

Fourteen continuous tissue culture cell lines derived from mouse, rat, or human granulocyte-macrophage cancers were studied for expression of spontaneous and inducible markers of differentiated cells. Five cell lines (two mouse, two rat, and one human) synthesized myeloperoxidase spontaneously, and a fifth mouse line showed biochemically inducible enzyme. Twelve lines (6 mouse, 3 rat, and 3 human) produced lysozyme (muramidase), and all had detectable beta-glucuronidase. Superoxide generation was detected in one mouse, and three human cell lines following stimulation with phorbol myristate acetate. Maturation to differentiated polymorphonuclear leukocyte or macrophage morphology was induced in 3 cell lines (2 mouse and 1 human) following culture in diffusion chambers in total-body-irradiated rats. In vitro morphological differentiation was inducible in one (mouse) cell line exposed to casein, thioglycolate, or plasma from irradiated rats or mice. These findings indicate that mammalian cell lines derived from granulocyte-macrophage cancers stably express several combinations of differentiation markers. The patterns of expression of these markers did not always correlate with the morphological stage of differentiation.

Animals↗
PubMed1977

Null-cell properties of a lymphoid cell line from a child with acute lymphoblastic leukaemia.

Cultured cells established from the bone marrow of a child with null-cell acute lymphoblastic leukaemia (ALL) have been studied. After 8 months in vitro, the cytological, cytochemical and immunological properties of the cultured cells were very similar to those of the patient's cells. Many of the cultured cells had morphological and cytogenetic abnormalities often found in acute leukaemia. The cells were EBNA-negative. This unique culture of ALL-derived null cells might provide information as to the aetiology and origin of malignant cells.

Antigens, Viral↗
PubMed1977

A humoral cytotoxic substance produced by a human killer cell line.

The production of a cytotoxic factor synthesized by human haemic killer cells growing in vitro is described. The factor can be found extra- and intra-cellularly. It is released from the cells by an apocrine form of secretion, illustrated by light and electron micrographs. The culture fluid from 14C-labelled killer cells reveals numerous radioactive bands following SDS-gel electrophoresis. The killing factor is precipitated by 30 to 60% saturation of ammonium sulphate. Cultures of human rhabdomyosarcoma and osteosarcoma cells are more susceptible to the killer cells than normal human dermal or lung fibroblasts. During contact or killer with target cells a higher level of cytotoxic activity can be detected in the culture fluid. The cell-killing activity is completely inactivated by 30 min at 60 degrees C, but it is not absorbed by target cells during 1 h of incubation. The cytotoxic factor is unlikely to be an interferon since it did not prevent the replication of a wide range of viruses and only a low level of interferon could be detected in the culture medium. The introduction of Strep. faecalis into cultures of killer cells caused their transformation into immunoblast-like cells, indicating their lymphoid origin. The cells did not phagocytose the microorganism. When the humoral factor was injected into fibro-sarcoma-bearing mice approximately 50% survived, whereas all control animals died.

Animals↗
PubMed1977

A human haemic cell line capable of cellular and humoral killing of normal and malignant cells.

A line of human leukaemia-derived cells is described that kills a wide range of human and animal cell lines, whether normal or malignant, even at a ratio of 1:1. During exposure to the target cells, the killer cells released a factor into the culture medium which destroyed target cells in the absence of the killer cells. This phenomenon occurs without exogenous complement and requires no pre-treatment of target or killer cells. The humoral factor is a protein precipitable by 60% saturation of ammonium sulphate and has a mol. wt. of approximately 70,000; It prevented the growth of a fibrosarcoma in mice.

Animals↗