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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cells infected with a temperature-sensitive mutant (ts-26) of Rauscher murine leukemia virus (R-MuLV) or with wild-type virus were labeled with 35S-methionine, and cell extracts were examined for radioactive polypeptides which could be precipitated by monospecific antisera to viral proteins. When shifted from permissive (31 degrees C) to nonpermissive (39 degrees C) temperature, cells infected with ts-26 rapidly begin to accumulate gPr90enr, the glycoprotein precursor to the membrane envelope glycoprotein gp70 and to the membrane-associated protein p15E. Simultaneously, formation of these mature virion proteins ceases. In addition, lactoperoxidase-catalyzed surface labeling with 125I--iodine indicates that the plasma membrane of cells infected with ts-26 becomes depleted of gp70 antigens at 39 degrees C. Nevertheless, at 39 degrees C these cells release defective MuLVs which lack gp70 and p15E but contain an outer membrane. The released particles also contain an aberrantly processed form of the major virion core protein p30, and many of these virion cores have an unusual immature crescent shape. It has previously been reported that cells infected with the ts-26 mutant of R-MuLV process a 65,000 dalton precursor (Pr65gag) of the virion core proteins more slowly at 39 degrees C than do cells infected with wild-type virus (Stephenson, Tronick and Aaronson, 1975). Although we have confirmed these results, this effect is relatively small and it is known that various alterations of MuLV assembly can lead secondarily to inhibited processing of Pr65gag. We propose that the ts-26 mutant has a primary temperature-sensitive defect in membrane glycoprotein synthesis and that this change causes pleiotropic effects on core morphogenesis.
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PMID:A murine leukemia virus mutant with a temperature-sensitive defect in membrane glycoprotein synthesis. 42 Dec 71

The IgE receptor of human basophils was purified by using simple and repetitive affinity chromatography on human IgE-Sepharose. Basophils were partially purified from peripheral blood of patients with chronic myelogenous or basophilic leukemia. Cells were labeled with 125I by using the lactoperoxidase method and were solubilized with nonionic detergent. Elution of IgE-Sepharose with 0.5 N acetic acid, 1% NP-40 allowed recovery of active IgE receptor. Analysis of human IgE receptor by SDS polyacrylamide gel electrophoresis with 10% gels demonstrated one major radioactive peak with an apparent m.w. of 58,000 to 68,000, somewhat larger than rat IgE receptor. The purified human IgE receptor was active since approximately 10 to 42% of labeled receptor could specifically rebind to insolubilized human IgE. Rebinding was blocked by nanomolar concentrations of soluble human IgE or rat IgE but not by human or rat IgG, heat-inactivated human IgE, or heat-aggregated human IgG; thus it appears that rat IgE receptor. The relative abilities of active rat IgE and active human IgE to inhibit human IgE receptor rebinding could not be precisely determined because of the limitations in assessing the proportion of human IgE that retains receptor-binding activity.
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PMID:Characterization of the IgE receptor isolated from human basophils. 48 84

The hairy-cells (HC) of 10 patients with hairy-cell leukaemia were studied with several techniques to evaluate their phagocytic potential. Mononuclear cells from normal donors and from patients with acute monocytic leukaemia served as controls. Light microscopically HC seemed to have ingested bacteria or latex particles. Treatment of the cells with lysostaphin, an enzyme that kills extracellular Staphylococcus aureus, showed that almost all 'ingested' bacteria were extracellular. Lanthanum nitrate, added during the fixation procedure for electron microscopy, stained both the outer cell membrane and the membranes of the 'phagosomes' of the HC, also indicating that the 'ingested' particles were extracellular. HC showed no increased oxygen consumption on exposure to bacteria in the presence of serum. Furthermore, HC showed no lysozyme or peroxidase activity, whereas non-specific esterase activity was much weaker than in monocytes. These findings, which show that HC are essentially non-phagocytic, constitute strong evidence against a monocytic origin of the malignant cells of hairy-cell leukaemia.
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PMID:Phagocytic potential of hairy cells. 49 73

The peripheral blood cells, spleen cells and bone marrow cells from a patient with hairy cell leukaemia were studied by means of several immunological methods and by phase contrast and electron microscopy. Both by light and electron microscopy the cells had the morphology of hairy cells. 60 % of all the peripheral blood cells, and 80 % of the spleen cells had membrane-bound IgGk immunoglobulin. 60 % of the peripheral blood lymphocytes and 90 % of the spleen cells were positive for Ia-antigens, and 80 % of the peripheral blood, and 70 % of the spleen cells had receptors for complement factor C3. The percentages of cells with receptor for the Fc part of IgC and receptors for sheep red blood cells (SRBC) were low both in peripheral blood and in spleen. Reduced numbers of peroxidase positive cells and cytotoxic plaque-forming cells were also observed as well as reduced lymphocyte responses after stimulation of peripheral blood lymphocytes with PHA, PWM, ConA, PPD and allogeneic cells. A normal antibody-dependent cell cytotoxicity (ADCC) and PHA-induced cytotoxicity was observed for the peripheral blood lymphocytes of the patients. Our results suggest that the hairy cells in our patient are derived from B lymphocytes and have a monoclonal origin.
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PMID:Characterization of peripheral blood, spleen and bone marrow cells from a patient with hairy cell leukaemia. 54 2

The polypeptide composition of murine fibroblast cells and the effect of infection by RNA sarcoma and leukemia viruses were analyzed by two-dimensional gel electrophoresis and tryptic peptide mapping. The polypeptide maps of NIH Swiss mouse embryo fibroblasts (NIH/3T3) and BALB/c mouse embryo fibroblasts (BALB/3T3) were very similar except for two major polypeptides of about 65,000 and 75,000 daltons which were not detected in BALB/3T3 cells. NIH/3T3 cells infected with either Rauscher or Gross oncoviruses and outbred Swiss mouse embryo fibroblasts (3T3 FL) showed two major polypeptrides of about 73,000 and 80,000 daltons not found in uninfected NIH/3T3 cells. The 3T3 FL cells, although uninfected, were also found to contain a high concentration of envelope glycoprotein of an endogenous oncovirus. 3T3 FL cells transformed by Moloney sarcoma virus showed changes in many polypeptides, including several major components: the disappearance or modification of a component of 60,000 daltons, an increased concentration and shift in pl of a glycoprotein of 48,000 daltons, and the apparent loss of several smaller polypeptides. None of the major changes of the transformed cells were associated with cell surface proteins labeled by lactoperoxidase-catalyzed iodination.
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PMID:Polypeptide maps of cells infected with murine type C leukemia or sarcoma oncovirus. 62 38

Human mast cells and basophil granulocytes can be easily recognized in normal tissues by light microscopy. In one mast cell and one basophilic leukemic case considered in this study, mast cells and basophils were morphologically quite similar and could not therefore be clearly defined merely by their morphological features. Both types of cells showed round nuclei and deep purple granules. The diagnosis of mast cell leukemia or basophilic leukemia was made on the basis of different cytochemical patterns. In the case of mast cell leukemia, peroxidase and PAS stains were negative, while chloroesterase was strongly positive; in the case of basophilic leukemia, peroxidase and PAS stains were positive, while chloroesterase reaction showed a peculiar pattern. Toluidine blue metachromasia and astra blue positivity were present in the cells of both cases.
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PMID:Mast cell leukemia and acute basophilic leukemia. Cytochemical studies. 74 30

The quantity of thymus-leukemia (TL) antigens expressed by murine leukemia cells is significantly greater than that expressed by somatic hybrids of such cells. Based upon the results of 125I-lactoperoxidase labeling and antibody absorption procedures, and corrected for size differences between the two cell types, the quantity of TL antigens expressed by RADA-1 cells, a radiation-induced murine leukemia cell line of strain A/J mice, is approximately 5.0 times greater than that of somatic hybrids of RADA-1 and LM(TK)- cells. LM(TK)- cells are a thymidine kinase-deficient TL(-) mouse fibroblast cell line. The quantity of TL antigens expressed is related only in part to their susceptibility to lysis by TL antibodies and guinea pig complement (GPC). RADA-1 cells resist lysis. The quantity of TL antigens expressed by RADA-1 cells is analogous to that formed by nonneoplastic thymocytes obtained from F1 hybrids of two strains of TL(+) and TL(-) mice; cells from both strains are sensitive to TL antiserum and GPC. ASL-1 cells, a spontaneously occurring leukemia cell line of A/J mice, express TL antigens in significantly higher quantities than any of the cell types examined. Exposed to TL antisera, the quantity of TL antigens of ASL-1 cells, but not that of hybrid cells, gradually diminishes. ASL-1 cells convert over a 6-h period of exposure to antibody and guinea pig complement (GPC) resistance; hybrid cells remain sensitive. However, ASL-1 cells converted to TL antibody and GPC resistance continue for a time to express TL antigens in quantities similar to that of sensitive F1 thymocytes and resistant RADA-1 cells. RADA-1 X LM(TK)- hybrid cells, which are sensitive to TL antibodies and GPC, express the lowest quantities of TL antigens of any of the cell types examined. It is likely that differences in the quantities of TL antigens expressed by different cell lines reflect genetic mechanisms controlling TL antigen expression. The failure of TL antisera to affect the quantities of TL antigens expressed by hybrid cells is taken as an indication that genetic controls governing antigen expression may be distinguished from those involved in regulating responsiveness to specific antiserum.
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PMID:Murine leukemia cell hybrids: the quantity of TL antigens expressed by parental and hybrid cells fails to correlate with their sensitivity to TL antibody and complement. 75 Jul 64

The peripheral blood of an acute myelomonocytic leukemia patient has been cultured for 16 months. The culture is at present at the 140th population doupling level. The cultured cells have the characteristics of so-called lymphoblastoid cells and proliferate actively as individual cells in small clusters, or in large clumps consisting of large mononuclear cells. Some of these cells appeare to be lymphoid, but the majority are immature mononuclear cells with a tendency to lobulate. They gave a weakly positive peroxidase reaction at the beginning of cultivation, and have given a strongly positive esterase reaction persistently. The cytoplasm shows ciliary or tail-like projections as the cell matures. Complement (C3) receptor and IgG receptors are found on the cell surface, and active phagocytosis is mannifest. Colloidal iron particles or viable red blood cells attached to the cell membrane suggesting possible differentiation to reticulum cells or macrophages. The cultured cells are mostly diploid but some cells show chromosome abnormality. Herpes type virus was foun in the nucleus, cytoplasma and on the cell membrane. The transplanatation of cultured cells to the cheek pouch of hamsters produced small tumors with histological findings resembling reticulum cell sarcoma.
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PMID:Characteristics of hematopoietic cell line established from human myelomonocytic leukemia. 82 70

The effect of glutaraldehyde fixation on lectin-mediated agglutination of murine leukaemia (GRSL) cells was investigated using 2 assay methods which differed in the shear forces to which the agglutinated cells were subjected. First, lectin and cells were allowed to interact under conditions in which shear forces were minimized and the degree of agglutination was evaluated microscopically by the appearance and size of the cell aggregates. This assay demonstrated that concanavalin A (con A)-, wheat germ agglutinin (WGA)- or Ricinus communis agglutinin I (RCAI)-mediated cytoagglutination was unaffected (WGA and RCAI) or somewhat enhanced (con A) by prior fixation of the cells with glutaraldehyde. Secondly, an electronic particle counter was used to measure the disappearance of single cells and concomitant appearance of cell aggregates as a function of the lectin concentration. In this assay, in which the aggregated cells are subjected to significant shear forces during dilution and cell counting, agglutination of GRSL cells by each of the 3 lectins was drastically inhibited by prior fixation of the cells with glutaraldehyde. This assay also demonstrated enhanced nonlectin-induced cell aggregation after fixation. In both cytoagglutination assays about the same lectin concentration was required for threshold agglutination of unfixed cells. Comparatively, the results of the 2 cytoagglutination assays indicate that a fraction of the lectin-mediated bonds between unfixed cells is shear resistant and that fixation of the cells either weakens these bonds or inhibits their formation. Morphologically, cells prefixed with glutaraldehyde were sperical at all lectin concentrations, with a continuous dense distribution of cell surface-bound con A, labelled directly with haemocyanin or indirectly using the peroxidase-diaminobenzidine reaction. Unfixed cells showed angular and toadstool-shaped deformations, especially at the highest lectin concentrations, the agglutinating surfaces being flattened against each other over extended areas. The distribution of con A label was continuous and dense between the apposed surfaces and discontinuous on free surfaces. In the presence of con A the free surfaces of prefixed cells exhibited more microvilli than the surfaces of non-prefixed cells. These results favour the view that fixation prevents the formation of shear-resistant, lectin-mediated bonds between cells, not by restricting the lateral mobility of lectin receptors, but by impairing the apposition of rigid cell surfaces.
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PMID:Effect on glutaraldehyde fixation on lectin-mediated agglutination of mouse leukaemia cells. 82 65

In 25 cases cytochemical types of acute leukemia were determined using the classification of Loeffler. Three cytochemical methods used were: p.a.S.-glycogen content, pox-peroxidase activity, and esterase activity determinatione. At the same time selective identification of lysosomes in perypheral blood blast cells was done using vital euchrisine staining and fluorescence microscopy. A correlation was observed between the cytochemical types of acute leukaemia and the lysosomal pattern. The fluorescence method of the identification of lysosomes is suggested for diagnosis of acute leukaemia.
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PMID:[Lysosomes of blast cells in various cytochemical types of acute leukemia]. 84 51


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