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

Friend virus (FV)-induced leukemic spleen cells from (B10.A X A)F1 mice were found to lose sensitivity to antibody-mediated lysis during progression of erythroleukemia. This was correlated with a 78% loss of FV-induced cell surface antigens as determined by quantitative absorption of cytotoxic antibodies and with a decreased percentage of leukemic spleen cells showing membrane immunofluorescence with anti-FV antibody. Antigen loss was observed only with virus-induced antigens, and was limited to antigens expressed on the cell surface. FV-induced antigens were regained when low-antigen leukemia cells from late stages of the leukemia were transferred to lethally irradiated nonimmune recipients, but not when these cells were transferred to hyperimmune lethally irradiated recipients. Conversely, when high-antigen leukemic spleen cells from early stages of the erythroleukemia were transferred to hyperimmune irradiated recipients, antigen loss was induced. The immune response to virus-induced antigens appeared to be involved in causing the antigenic changes observed on leukemia cells in this system.
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PMID:Antibody-induced loss of Friend virus leukemia cell surface antigens occurs during progression of erythroleukemia in F1 mice. 28 46

Fetal liver cells of DBA/2 mice were infected with the anemic strain of Friend leukemia virus (FLV-A), which has no spleen focus-forming virus (SFFV) activity. The infected cells were grown in medium with or without erythropoietin. Transformed lines were isolated only from the infected cultures that had been treated with erythropoietin at the time of their initiation. The properties of three permanent cell lines in serial passage for over 2 years are described. Each has an aneuploid karyotype. Only the immature hematopoietic cells of the first line have metacentric chromosomes. They grow in suspension, as do the erythroleukemic lines derived from leukemic spleens of FLV-infected mice, and clone on agar. They produce tumors resembling reticulum cell sarcomas upon subcutaneous inoculation into syngeneic hosts. Stimulation of differentiation induced after treatment with dimethyl sulfoxide identifies the cells of the first line as being erythroid in origin. The two other lines are adherent and epithelioid in appearance. These lines may have originated from the nonhematopoietic cells present in fetal liver. No tumors were produced after the subcutaneous inoculation of 10(6) cells. All three lines synthesize virus. The virus is attenuated for leukemogenicity and has no SFFV activity. The transforming event appears to be specific, because fetal liver cells from C57BL/6 mice, which are resistant to the induction of leukemia by FLV, were not affected by the virus. Malignant transformation of erythroid cells by FLV-A in vitro confirms the in vivo findings that SFFV may not be a necessary prerequisite for the induction of erythroleukemia in susceptible hosts.
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PMID:Transformation of DBA/2 mouse fetal liver cells infected in vitro by the anemic strain of Friend leukemia virus. 28 21

The spontaneous regression of the erythroleukemia induced by the regressing Friend murine leukemia virus (F-MuLV) complex was inhibited by irradiation of the animals prior to F-MuLV inoculation. This inhibition was proportional to the dose of radiation used. Treatment of the mice with the bone-seeking isotope 89Sr also inhibited erythroleukemia regression, which implicates the same effector mechanisms involved in the resistance to F-MuLV or F-MuLV-induced immunosuprression. Erythroleukemias induced in athymic nude mice by the regressing F-MuLV complex exhibited higher rates of lethality than did the leukemias in heterozygous or homozygous thymus gland-containing controls. These data suggested the involvement of the immune system in erythroleukemia regression and the specific participation of thymus cells and an 89Sr-susceptible function, perhaps marrow-dependent cells, in the process of regression.
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PMID:Spontaneous regression of Friend murine leukemia virus-induced erythroleukemia. IV. Effects of radiation and athymia on leukemia regression in mice. 28 33

Preleukemic disorders are a controversial group of panmyelopathic disturbances that often precede the emergence of acute myeloblastic or myelomonocytic leukemia. In most instances, these preleukemic disorders are characterized by slowly developing myeloblastosis of the bone marrow. They include preleukemia, primary acquired panmyelopathy with myeloblastosis or smouldering acute leukemia, erythroleukemia, and subacute myelomonocytic leukemia. Sometimes, transitions between these various preleukemic disorders may be observed in a single individual. Abnormalities in cellular differentiation are expressed in cytochemical aberrations and in elaboration of colony forming units by marrow cells of patients with preleukemic disorders. Cytogenic and cellular kinetic abnormalities link preleukemic disorders closely to acute myeloblastic or myelomonocytic leukemia, although in many patients with preleukemic disorders, conversion to acute leukemia is not observed or perhaps not recognized. Understanding pathogenetic and pathophysiological aspects of preleukemic disorders may shed light on aspects of cellular proliferation and cellular differentiation in the acute leukemias.
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PMID:New aspects of preleukemic disorders. 29 Apr 53

The nature and distribution of sequences related to the murine erythroleukemia virus, Friend spleen focus-forming virus (SFFV), have been analyzed by using a radioactive cDNA probe specific for the SFFV genome (cDNA(sff)). From the proportion of high molecular weight viral [(32)P]RNA which hybridized to cDNA(sff), it was estimated that these sequences represent about 50% of the SFFV genome, indicating a genetic complexity of about 3300 nucleotides. cDNA(sff) hybridized extensively (80-95%) to SFFV virion RNA and to cellular RNA from murine and rat cells productively or nonproductively infected with SFFV. Only background homology was detected between cDNA(sff) and viral RNA from a number of murine [Friend murine leukemia virus (MuLV), Moloney-MuLV, and Kirsten sarcoma virus] and nonmurine (Rous sarcoma virus, feline leukemia virus, baboon endogenous virus, and Mason-Pfizer mammary tumor virus) retroviruses. Limited homology was also detected to a number of murine xenotropic and mink cell focus-inducing viruses (20-35%) as well as Rauscher leukemia virus (50%). Nucleotide sequences homologous to cDNA(sff) were also detected in the DNA of normal cells of several mouse strains as single or a few copies per cell. Thermal denaturation analysis indicated that duplexes formed between cDNA(sff) and normal DBA/2J cellular DNA have a reduction in melting temperature of 2 degrees C when compared with the dissociation of hybrids between cDNA(sff) and homologous sequences in SFFV-infected mouse spleen cell DNA. Examination of cellular RNA from uninfected mouse cells indicated that SFFV-related RNA sequences were also expressed in varying degrees in different tissues of adult DBA/2J mice. The highest amounts were observed in cells from bone marrow and spleen, whereas considerably lower amounts were found in cells from the thymus and kidney. No SFFV-related sequences could be detected in RNA extracted from liver, muscle, or fibroblasts. The presence of these SFFV-related sequences in normal, uninfected mouse cell DNA and their differential expression in hematopoietic tissues suggest that these sequences may be an integral part of the program of both normal and leukemic hematopoietic cell differentiation.
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PMID:Presence and expression of Friend erythroleukemia virus-related sequences in normal and leukemic mouse tissues. 29 76

Friend murine leukemia cells induced to undergo erythrocytic differentiation by dimethyl sulfoxide give rise to progeny resembling ortho- or polychromatic normoblasts, which usually do not complete the maturation process to yield forms analogous to erythrocytes. Treatment of these differentiated cells with cytochalasin B can lead to a high proportion (i.e., 80-85%) of enucleated cells in vitro. Nuclear extrusion in cells induced to differentiate by dimethyl sulfoxide and subsequently treated with cytochalasin B began within 24-36 hr of exposure to the antibiotic, with the appearance of a pre-enucleated stage in which the cell nucleus became pycnotic and eccentrically located. Maximum enucleation occurred after 72-96 hr of exposure to cytochalasin B and was significantly enhanced when dimethyl sulfoxide was included in the culture medium during the period of treatment with cytochalasin B. Enucleation appeared to take place only in differentiated progeny, because nondifferentiated cells treated with cytochalasin B alone yielded a population of multinucleated cells. The findings indicate that highly tumorigenic nondifferentiated Friend erythroleukemia cells can be converted in high yield to mature enucleated forms that are unable to proliferate in vitro.
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PMID:Enucleation of differentiated murine erythroleukemia cells in culture. 29 26

Immunization of rabbits with rat leukemia DBLA-6 resulted in the production of antisera which upon absorption with hepatoma cells were specific for rat immature T lymphocytes. The antisera showed cytotoxicity against thymocytes and killed 75 approximately 90% of them, whereas the antisera had no cytotoxic effect on peripheral lymphocytes from the spleen, lymph node, and bone marrow of rats. The antisera also showed cytotoxicity against rat lymphatic leukemia and lymphoma cells of all lines tested but not against rat myelogenous leukemia and erythroleukemia cells. The cytotoxic activity of anti-DBLA-6 serum was completely absorbed with rat brain or thymocytes.
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PMID:Heterologous antiserum to a subpopulation of thymocytes and lymphomas in rats. 31 55

Studies are described employing two erythropoietic systems to elucidate regulatory mechanisms that control both normal erythropoiesis and erythroid differentiation of transformed hemopoietic precursors. Evidence is provided suggesting that normal erythroid cell precursors require erythropoietin as a growth factor that regulates the number of precursors capable of differentiating. Murine erythroleukemia cells proliferate without need of erythropoietin; they show a variable, generally low, rate of spontaneous differentiation and a brisk rate of erythropoiesis in response to a variety of chemical agents. Present studies suggest that these chemical inducers initiate a series of events including cell surface related changes, alterations in cell cycle kinetics, and modifications of chromatin and DNA structure which result in the irreversible commitment of these leukemia cells to erythroid differentiation and the synthesis of red-cell-specific products.
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PMID:Regulation of differentiation in normal and transformed erythroid cells. 34 91

Erythroleukaemia in an elderly Caucasian male was associated with the presence of 15% of haemoglobin H (Hb-H; Hb-beta4) in the haemolysate, identified by electrophoretic analysis, isolation and 'finger-printing'. The peripheral blood picture was dimorphic, with 40% of hypochromic and morphologically abnormal red cells. Inclusion bodies indicative of the presence of Hb-H occurred in 30% of the red cells after supravital staining. The rare occurrence of Hb-H in leukaemic conditions and its distribution in the red cells is discussed in relation to the possible clonal origin of leukaemia and the involvement of red cell precursors.
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PMID:Occurrence of haemoglobin H in leukaemia: a further case of erythroleukaemia. 41 4

Enzymatic studies were performed on erythroblasts obtained from marrows of 2 patients with untreated erythroleukemia. Cytochemically, erythroblasts showed abnormalities of several enzymes involved in carbohydrate metabolism, as well as abnormalities of specific and nonspecific esterases. Electrophoretic analysis of esterases extracted from predominatly erythroid marrows showed strong moderately fluoride-resistant nonspecific esterase activity with alpha-naphthyl acetate, and weak activity with alpha-naphthyl butyrate. Isoenzymatic patterns of specific esterase activity in erythroleukemia were indistinguishable from those found in myeloblastic leukemia. The results are consistent with the concept of the Di Guglielmo syndrome in which a preleukemic erythroid disorder may precede the emergence of acute myeloblastic or myelomonocytic leukemia.
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PMID:Enzymatic abnormalities in erythroleukemia. 41 53


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