Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The marrow of chicks with leukemia induced by avian 'myeloblastosis' virus (AMV) exhibited a 5-10-fold increase in the number of fibroblast colony-forming cells (CFU-F). The increased CFU-F correlated with a mild fibrosis which can be seen in the marrow of these animals. Fibroblast proliferation likely was not simply due to the presence of leukemic cells because addition of formaldehyde-fixed peripheral leukemic cells failed to initiate CFU-F growth. Conditioned medium (CM) from day-4 cultures of peripheral leukemic cells was markedly stimulatory to CFU-F growth. The stimulatory activity was not due to virus released from the leukemic cells as, (1) removal of virus by pelleting had no effect on the CM activity and (2) direct inoculation of CFU-F cultures with virus failed to stimulate CFU-F growth. Normal avian marrow macrophage monolayers also released high levels of a fibroblast growth factor and both the macrophage-derived and leukemic cell-derived factors were heat-labile (65 degrees, 30 min).
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PMID:Avian monocytic leukemia cells release fibroblast growth factor: implications to associated myelofibrosis. 386 25

A suspicion of an excess cancer risk in automotive model shops prompted the Industrywide Studies Branch, NIOSH, to conduct a proportionate mortality study and an industrial hygiene characterization of operations in these shops. The mortality study showed a statistically significant excess proportion of deaths due to colon cancer and leukemia (for woodshops only). The materials used in the model shops include various natural woods, laminated woods, plastics, resins, varnishes, putties and paints. Personal breathing zone samples were collected for total and respirable dust, amines, various hydrocarbons (including styrene, and toluene), formaldehyde, and nitrosamines. Particle size distribution studies were conducted on the wood dust and bulk airborne samples of dusts were subjected to various mutagenicity test systems. Work practices, ventilation and general housekeeping were checked. Total wood dust samples ranged from 0.03 to 25 mg/m3 with an average around 1.0 mg/m3. The percent respirable dust ranged from 19 to 38% as measured with Andersen impactors. Solvent exposure samples ranged from non-detectable to about 10% of the OSHA Permissible Exposure Levels. Relevant recommendations for improvement of contaminant control were made.
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PMID:Industrial hygiene characterization of automotive wood model shops. 388 Jan 87

Avian sarcoma virus-, or 3,4-benzopyrene-transformed cultured rat cells and human leukemia or lymphoblastoid cell lines were radiolabeled by reductive methylation with formaldehyde and tritiated sodium borohydride--an application of a known technique for radiolabeling of soluble proteins. Optimal conditions for tritium incorporation into cell proteins with the aid of this technique were ascertained. Analysis of cell proteins tritium radiolabeled with the aid of this technique by acrylamide electrophoresis or by two-dimensional electrophoretic analysis allowed to disclose typical transformation-associated alterations in oncovirus-, or chemical carcinogen-transformed cells, as well as cell type-associated protein patterns in examined lymphoid cell lines. An individual protein (class II MHC antigen) radiolabeled by this technique has been identified as bimolecular complex p30,35 by immunoprecipitation with a monoclonal antibody recognizing this antigen; electrophoretic properties of immunoprecipitated antigen were identical to those observed after immunoprecipitation of the same antigen radiolabeled by sodium periodate/tritiated borohydride glycoprotein radiolabeling.
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PMID:A simple technique for cell surface radioactive labeling of human and animal neoplastic cells: reductive methylation with formaldehyde and tritiated borohydride. 404 51

Further evidence implicating murine leukemia-like virus in the disorders of NZB mice was afforded by a study of antigens associated with murine leukemia virus (MuLV). MuLV group antigens were prevalent in extracts of spleen, kidney, and, to a lesser extent, thymus throughout a substantial portion of the life span of NZB mice as well as in extracts of lymphomas and sarcomas indigenous to the strain. G (Gross) soluble antigen, type-specific antigen, was first detected in plasma of untreated NZB mice at 3 months of age. G soluble antigen production increased thereafter in line with age, with 50% of reactions becoming positive at 5.3 months and 100% at 7 to 9 months. From months 3 to 9, the time-response curve for positive conversion of direct antiglobulin (Coombs) tests in untreated NZB mice corresponded closely to that for G soluble antigen production. Beyond the 9th month, G soluble antigen underwent elimination from the plasma of NZB mice, with positive reactions reduced to 50% at 13.3 months and to 0% at 18 months. G natural antibody was first detected in the serum of NZB mice at about 10 months of age and increased thereafter in line with age. The curves for G antibody production and G soluble antigen elimination bore a reciprocal relation to each other with crossover at 50% response occurring at 13.3 months. Significant proteinuria, a functional manifestation of membranous glomerulonephritis, became increasingly prevalent in female NZB mice as G soluble antigen was eliminated from plasma. Cumulative mortality of female NZB mice, mainly attributable to renal glomerular disease, increased in phase with G antibody production. MuLV group antigens were identified in the glomerular lesions by the immunofluorescence method. Positive conversion of direct antiglobulin tests was significantly delayed by vaccinating baby NZB mice with formaldehyde-inactivated cell-free filtrates of older NZB mouse spleens. The plasmas of vaccinated NZB mice with negative direct antiglobulin reactions at 4 to 7 months were likewise negative when tested for G soluble antigen. The 50% response time for G antibody production in the vaccinated NZB mice occurred at 7.3 months, that is, 6 months earlier than in untreated NZB mice. The collective findings implicate murine leukemia-like virus in the etiology of autoimmune hemolytic disease and membranous glomerulonephritis, as well as malignant lymphoma, of NZB mice and suggest that virus-specified cell-surface and soluble antigen is a factor in the immunopathogenesis of the renal disease and possibly also the autoimmune hemolytic disease.
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PMID:Further implication of murine leukemia-like virs in the disorders of NZB mice. 430 80

Cells producing the Rauscher strain of murine leukemia virus (MLV) were exposed to (3)H-uridine, and labeled virus was collected at hourly intervals. Ribonucleic acid (RNA) extracted from virions (vRNA) had a characteristic single peak when analyzed by electrophoresis in polyacrylamide-agarose composite gels. Exposure of vRNA to dimethyl sulfoxide, urea, formaldehyde, or heat altered the mobility to a faster moving form (vRNA'). This vRNA' sedimented more slowly than native vRNA in sucrose gradients. Incubation of labeled virions at 37 C resulted in fragmentation of viral RNA which was detectable only after denaturation. Also, large differences in the temperature required for the change from vRNA to vRNA' were seen with alterations in NaCl concentration. These experiments demonstrate that the vRNA of MLV is held in a specific conformation by hydrogen bonds distributed over a large part of the molecule. The possibility that an undefined factor is associated with viral RNA is discussed.
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PMID:Analysis of the ribonucleic acid of murine leukemia virus. 430 79

In order to investigate the properties of the membrane-bound IgE-receptor complex, a simple procedure has been adapted for preparing large plasma membrane vesicles from rat basophilic leukemia cells. These vesicles pinch off from the adherent cells after treatment with 2 mM N-ethylmaleimide or 50 mM formaldehyde and 1 mM dithiothreitol, and they are isolated from the supernatant after two centrifugation steps with yields of 20-25% of the initial cell-bound 125I-IgE. With phase and fluorescence microscopy, micron-size vesicles are seen which are unilamellar and spherically shaped and devoid of intracellular organelles. On dextran gradients at least 70% of the 125I-IgE is bound to membranes which band at low density, indicating large, intact vesicles that are impermeable to macromolecules. Between 60 and 75% of the bound 125I-IgE is accessible to the external medium, showing the vesicles to be predominantly right side out. This preparation was found to be suitable for resonance energy-transfer measurements. We have determined that amphipathic, fluorescent donor and acceptor probes partition into the vesicle bilayer in a randomly distributed, noninteracting manner. The densities of the probes can be ascertained directly from the amount of energy transfer that is observed as a function of acceptor concentration. This experimental system will allow energy-transfer measurements to determine distances between sites on receptor-bound IgE and the membrane surface.
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PMID:Structural studies on the membrane-bound immunoglobulin E-receptor complex. 1. Characterization of large plasma membrane vesicles from rat basophilic leukemia cells and insertion of amphipathic fluorescent probes. 622 55

Mouse fibroblasts chronically infected with Moloney murine leukemia virus (MuLV) were fixed using variable amounts of formaldehyde, then examined by indirect immunofluorescence light microscopy. Several antisera were employed to detect both external and internal antigens associated with the cells, eg, MuLV gp70, tubulin, vimentin, and actin. Our results indicate that the cell membranes could be partially permeabilized to IgG molecules directed against the three cytoskeletal antigens only after 3.7%, but not 1%, formaldehyde treatment. Complete permeabilization was achieved by subsequent acetone treatment of cells after 3.7% formaldehyde fixation. In such cells, normal-appearing cytoskeletal networks of microtubules and intermediate filaments were observed. Stress fibers were also seen; however, they appeared less numerous and thinner than those of uninfected mouse fibroblasts. Further, a significant amounts of F-actin fluorescence was localized in granules in the cytoplasm of infected cells. Similar observations were made using JLS-V9 mouse cells chronically infected with 334C virus, another MuLV. These results taken together suggest that subtle differences exist in the organization of actin within MuLV-infected and uninfected mouse fibroblasts.
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PMID:The cytoskeleton of murine leukemia virus (MuLV)-infected mouse fibroblasts as observed under varying conditions of formaldehyde fixation. 631 3

We recently reported that the distribution and location of Moloney murine leukemia virus-derived membrane-associated gp70 and p30 antigens on the surface of 3.7% formaldehyde-fixed, chronically infected mouse fibroblasts were completely distinct, as judged by immunofluorescent light microscopy (M. Satake, P. N. McMillan, and R. B. Luftig (1981), Proc. Nat. Acad. Sci. USA 78, 6266). gp70, one of the two env gene products, exhibited a multiple-dot fluorescent pattern on the external surface of infected cells, while p30, one of the gag gene products, exhibited a diffuse fluorescence pattern which was apparently derived from Pr65gag molecules associated with the cytoplasmic face of the cell membrane. We have now examined the membrane fluorescence patterns of p15E, the other env gene product, as well as p15, p12, and p10, the other gag gene products. In these studies, both multivalent and monoclonal antibodies as well as fluorescein- and rhodamine-conjugated probes were used. We found that: (i) each of the env gene products, gp70 and p15E, exhibited characteristic and distinctive multiple-dot staining patterns. Further, each protein was labeled on intact cells with 125I-protein A plus homologous antiserum, confirming that both gp70 and p15E had externally exposed antigenic determinants. (ii) Among the gag gene products, p15 exhibited a different membrane fluorescence pattern than the diffuse pattern seen with p30, p12, and p10. The p15 pattern had an additional multiple-dot component. (iii) By double immunofluorescence we observed that the p15E and p15 multiple-dot patterns were superimposable at the same loci on infected cells. These three results suggest, first, that the cleavage of gp70 and p15E occurs prior to the arrival of the env polyprotein precursor at the cell surface and, second, there is an association between p15E and p15 antigenic determinants at the cell membrane. This latter association between an env and a gag gene product may be important for viral assembly.
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PMID:Comparative immunofluorescence of murine leukemia virus-derived membrane-associated antigens. 633 47

An attempt has been made to prepare antibodies against leukaemia-specific surface antigens by immunizing (C57 B1/6 X C3H/He)F1 mice with formaldehyde-stabilized AKR leukaemic cells. The presence of antibodies was examined by indirect immunofluorescence microscopy (IFM) and the indirect antiglobulin rosetting reaction (IARR). Galactose oxidase treatment destroyed the ability of leukaemic cells to react with antibodies prepared in the hybrid mice, an effect that was reversed by treating the enzyme-modified cells with borohydride. Analysis by immunoprecipitation and polyacrylamide gel electrophoresis of leukaemic cells, labelled by the galactose oxidase/[3H]-NaBH4 technique, indicated that a group of glycoproteins of apparent molecular weight greater than 70 000 was involved. Antibodies could be raised in AKR mice to the same group of glycoproteins by immunization with irradiated leukaemic cells or irradiated neuraminidase-treated leukaemic cells. The level of antibody raised in AKR mice had no effect on the growth of leukaemic lymphoblasts introduced subcutaneously into the host. Antibodies prepared in hybrid mice against leukaemic cells also were absorbed by lymphoid cells of pre-leukaemic 6-month-old AKR mice, indicating that contrary to previous claims in the literature antigens detected by such antisera are not related to malignancy. Hybrid mouse serum cross-reacted with antigens from purified RNA virus isolated from Abelson lymphoma, as demonstrated by the immunoelectrophoretic blotting technique. The pattern of reactivity was not appreciably altered following the absorption of antibodies directed against leukaemic cells. It is concluded that the glycoproteins detected by us may not be viral antigens but normal high molecular weight lymphoid glycoproteins with altered glycosylation patterns that are induced when the viral genomes are expressed.
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PMID:Glycoproteins of the AKR leukaemia cell surface and their relevance to leukaemia-specific surface antigens. 636 29

All of 23 different preparations of formaldehyde-fixed and heat-killed bacteria induced the appearance of high levels of interferon (IFN) in cultures of human peripheral blood mononuclear leukocytes. Some bacteria induced peak IFN titers after 24 h of culture, whereas other bacteria showed maximal titers on culture days 2 to 3. The IFN displayed various properties. One type, which appeared early during the cultures, had characteristics of IFN-alpha, being resistant to pH 2 treatment but neutralized by antibodies to IFN-alpha. A second type, which appeared later, on culture days 2 to 3, resembled IFN-gamma in being sensitive to pH 2 treatment but resistant to anti-IFN-alpha antibodies. A third type, which appeared to be sensitive to both pH 2 and antibody treatment, was interpreted as atypical IFN-alpha. The application of cell fractionation procedures indicated that nonadherent, predominantly Fc receptor-bearing, non-T, non-B cells were producers of IFN-alpha as defined by its antigenic properties. They copurified approximately with cells carrying natural killer activity toward human erythroid leukemia K562 cells. Some bacteria apparently also stimulated T lymphocytes to produce material with properties of IFN-gamma.
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PMID:Characterization of interferons induced by bacteria and interferon-producing leukocytes in human peripheral blood. 640 64


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