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Query: UMLS:C0002871 (anemia)
 52,094 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Leukemias induced by neonatal inoculations of several mouse strains with different strains of Friend murine leukemia helper virus (F-MuLV) were followed for time of disease onset, cytochemical analysis of predominant cell types in leukemic organs, and expression of infectious mink cell focus-inducing (MCF) viruses detected by mink cell foci or MCF-specific monoclonal antibodies. Most BALB.B and IRW mice had a rapidly appearing, severe anemia and hepatosplenomegaly consisting of erythroid cells. MCF viruses were usually isolated from enlarged spleens of IRW mice. In contrast, C57BL/10 mice had a lower incidence of disease and much slower course. Splenomegaly and lymphadenopathy with mild anemia were seen, and the predominant cell types were either myeloid (chloroleukemia) or lymphoid. MCF viruses were never isolated from this mouse strain. (C57BL/10 X IRW)F1 mice were intermediate in latency, but all mice had disease by 8 months. Myeloid, lymphoid, and some mixed leukemias with an erythroid component were observed, but in no case did we see the severe anemia or pure erythroid involvement typical of IRW and BALB.B mice. MCF viruses were, however, isolated from 22% of these mice regardless of leukemia cell type. DBA/2 mice had a disease pattern similar to the (C57BL/10 X IRW)F1 mice, and MCF viruses were isolated from three of six mice tested. Inoculation of IRW mice with the low virulence B3 strain of F-MuLV produced disease with a longer latency than F-MuLV 57, but similar cell types were transformed by both viruses. In vitro cell lines were derived from 14 mice, and most were tumorigenic in vivo. Three lines released infectious MCF virus, and three others expressed MCF-specific cell surface antigens but did not release virus. Eight lines expressed no MCF infectious virus or viral antigens. Several lines released infectious xenotropic viruses and/or expressed xenotropic MuLV cell surface antigens recognized by monoclonal antibodies reactive with xenotropic viruses. The lack of MCF expression in many primary leukemic tissues as well as in in vitro derived leukemia cell lines of C57BL/10 and (B10 X IRW)F1 mice suggested that MCF virus generation and expression may not be required for leukemogenesis in some mouse strains or in some hemopoietic lineages.
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PMID:Effect of murine host genotype on MCF virus expression, latency, and leukemia cell type of leukemias induced by Friend murine leukemia helper virus. 630 93

A new cell line designated SQ-A was established from the spleen of a leukemic DBA/2J mouse inoculated with the anemic strain of Friend erythroleukemia virus (FLV-A). The cells are similar in morphology, growth pattern, and tumorigenicity to our prototype erythroleukemia line 5-86 but are more sensitive to the cytotoxic effects of inducers of differentiation. The virus produced by SQ-A cells induces erythroleukemia associated with anemia in adult mice but has little activity when assayed on XC cells. It was characterized to determine what factors influence its leukemogenic potential. As compared to the attenuated virus from cultures of 5-86 and G-2 cells, the subunits of the RNA from the virions of SQ-A cells are the same size, and the amount of reverse transcriptase activity and RNase H present in the purified virions of the three lines are similar. However, differences are observed in levels of endonuclease and protein kinase. Both enzymes are increased in SQ-A virions. The activity of protein kinase in SQ-A virions is about 5 times higher than that in the attenuated virions. The number of polypeptides and their phosphorylation patterns also distinguish the virions of SQ-A. Whereas 5-86 virions contain seven proteins, three of which are phosphorylated in vitro, SQ-A virions contain eight proteins, all of which are phosphorylated. The extra protein in SQ-A virions has a molecular weight of 25,000 and is not glycosylated.
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PMID:Characterization of leukemogenic virus produced by a new line of Friend erythroleukemia virus-transformed cells. 632 17

The levels of serum thymic factor(s) (STF), of Thy-1.2 positivity of splenocytes [as measured by their azathioprine (AZ) sensitivity], and of Thy-1.2-positive "spontaneous" spleen rosette-forming cells (SSRFCs), as well as the presence of infectious virus in the thymus, were assessed as a function of time after virus inoculation in susceptible DBA/2, partially resistant BALB/c, and fully resistant C57BL/6 mice given the polycythemia- or anemia-inducing strain of Friend leukemia virus (FLV-P and FLV-A, respectively). As early as Days 2 to 3, the levels of STF and of AZ sensitivity of splenocytes were profoundly decreased in DBA/2 mice, and, to a lesser extent, in BALB/c mice given FLV-P; however, SSRFCs/spleen were increased in both mouse strains. Conclusive evidence of infectious FLV-P was obtained in the thymuses of DBA/2 mice soon after infection. In mice of the same strains infected with FLV-A, STF levels were similarly decreased, but AZ sensitivity of splenocytes was unaffected, and SSRFCs were decreased. Evidence of early FLV-A infection in the thymus of DBA/2 mice was likewise obtained. In C57BL/6 mice given FLV-A, STF levels, AZ sensitivity of splenocytes, and SSRFC showed changes similar to, but of lower magnitude than, those in BALB/c mice. On the other hand, in C57BL/6 mice given FLV-P, the decrease in STF and AZ sensitivity was almost as pronounced as in susceptible DBA/2 mice in the face of complete absence of infectious virus or viral markers in the thymuses. The observed changes are ascribed to virus infection in view of the following: (a) good temporal correlation between these changes and virus infection; (b) absence of any change in mice given heat-inactivated viruses or spleen homogenate of normal DBA/2 mouse spleen; (c) overall good correlation between mouse genotype and genetic (Fv-1 and Fv-2) restrictions of virus infection on one hand and the magnitude of the observed changes on the other. In particular, the decrease in STF and SSRFC levels is ascribed to the replication-competent (Friend-murine leukemia virus) component of Friend leukemia virus complex, whereas the decrease in AZ sensitivity of splenocytes and the increase of SSRFCs are ascribed to the defective spleen focus-forming virus component of the complex. All changes described so far were transient, since they were not detectable beyond 42 days after virus inoculation in overtly leukemic animals. The observed derangements of thymus-derived immune functions may play an important cofactor role during the onset of leukemia in mice genetically permissive to Friend leukemia virus replication and transformation, but they do not seem relevant to the maintenance of leukemia.
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PMID:Effects of in vivo Friend leukemia virus infection on levels of serum thymic factors and on selected T-cell functions in mice. 634 70

Two strains of Friend virus differ in their in vivo actions in that one strain induces anemia (FVA), while the other induces polycythemia (FVP). This study characterizes differences in the in vitro effects of these viruses on hematopoietic cells of (BALB/c x DBA/2)F1 mice. Both variants induced erythroid bursts that proliferated and differentiated without added erythropoietin (EPO). However, while the bursts induced by FVP were well "hemoglobinized" (i.e., most cells contained hemoglobin), the cells of FVA-induced bursts contained little or no hemoglobin. The nonhemoglobinized bursts, induced by FVA, were established to be erythroid by cytochemistry, electron microscopy, and hormone sensitivity. FVA-induced cells appeared to be hypersensitive to EPO, since small concentrations of the hormone produced marked increases in hemoglobin production--even when the hormone was added to the culture 3 days post infection. Time-lapse photography documented that EPO stimulated hemoglobin synthesis in virally transformed cells rather than uninfected erythroid precursors. This observation of FVA-induced hypersensitivity prompted the reexamination of the hormone requirements of FVP-induced bursts--previously considered to be EPO-independent. Reduction of the serum in the cultures allowed the demonstration that FVP-induced erythroid cells also were hypersensitive to EPO. Thus FVA and FVP can be readily distinguished in vitro by the relative EPO sensitivity of virus-induced bursts. From these findings, a hypothesis is drawn: i.e., oncogenic transformation may result from increased sensitivity of progenitor cells for natural, physiologic regulators, and transformation is not necessarily accompanied by a block in differentiation. In addition, since hypersensitive virus-induced bursts could be recognized and picked from the cultures, these studies provide a method for obtaining highly purified erythroid precursors for the study of the regulation of terminal differentiation by EPO and other regulatory factors.
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PMID:Increased erythropoietin sensitivity after in vitro transformation of hematopoietic precursors by RNA tumor viruses. 657 60

Hematological assays of inbred specific pathogen-free (SPF) mice of ten different strains inoculated with Friend leukemia virus (FLV) were performed chronologically to assess whether the genetic control of the host may play an important role in viral oncogenicity. Mice strains C57BL/6J, B10 (H-2b) and B10D2 (H-2d) were FLV-resistant, BALB/c, DBA/2N (H-2d), RFM (H-2f), AKR and 80% of CBA/JN (H-2k) were FLV-sensitive (polycythemia) and C3H/He, B10Br and 20% of CBA/JN (H-2k) were FLV-sensitive (anemia). Only the AKR strain mice showed a spontaneous regression of splenomegaly. These results indicate that there is not a strong but a weak correlation between the H-2 haplotype and the reaction to FLV. The main phenomenon in the anemic mice was the monotonous proliferation of the naked blastic cell, whereas that in the polycythemic mice was the enormous increase of the mature erythroblast and the decrease of the naked blastic cell in the later phase. These facts suggest that the naked blastic cell in the mice with polycythemia are reactive and that in the mice anemia truly neoplastic.
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PMID:Relation between Friend leukemia virus-induced leukemia and genetic control of the host. 658 86

Appearance of tumorigenic cells was studied in DBA/2 and ICFW mice infected either with the polycythemia-inducing or the anemia-inducing strain of Friend leukemia virus. Tumorigenicity was defined by transplantability of virus-infected cells into the omentum of an isogeneic preirradiated host. Tumorigenic cells were detected in 50% of the leukemic donors 3 wk after infection by the polycythemia-inducing strain and 7-8 wk after infection by the anemia-inducing strain. These cells appeared first in the spleen and later in peripheral blood, bone marrow, and liver. They consisted of a heterogeneous population at different degrees of malignancy as determined by successive transfers in vivo and in vitro. The observations clearly show that leukemias induced by Friend viruses evolve by multistep processes, in which different stages of malignancy can be detected.
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PMID:Emergence of tumorigenic cells during the course of Friend virus leukemias. 694 62

In mice with "diffuse" hemoglobin (Hb), the decrease in the proportion of minor Hb during ontogeny qualitatively resembles the decline observed in human Hb F. Since Hb F reappears during some forms of erythroid stress, we investigated the effect of hematopoietic stress on minor Hb in DBA/2 mice. The stresses were acetlyphenylhydrazine-induced hemolysis, phlebotomy, or infection with Friend erythroleukemia virus. Recovery from anemia was associated with a transient increase in the synthesis of minor Hb similar to the reappearance of Hb F in man. Minor Hb synthesis also increased during the evolution of erythroleukemia induced by both the anemic and the polycythemic strains of virus. Thus, the mouse model can be used to study Hb regulation, since changes in the modulation of minor Hb synthesis occur under conditions which are associated with alterations in Hb F synthesis in humans.
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PMID:Increased mouse minor hemoglobin during erythroid stress: a model for hemoglobin regulation. 695 22

Strain variation in the level of resistance to malaria was investigated in inbred strains of mice after infection with Plasmodium chabaudi. When infected intraperitoneally with 10(6) P. chabaudi-parasitized erythrocytes, mice of 11 inbred strains could be separated into two groups by using survival time as the criterion; C57BL/6J, C57L/J, DBA/2J, CBA/J, and B10.A/SgSn mice were found to be resistant to P. chabaudi, whereas A/J, DBA/1J, BALB/c, C3H/HeJ, AKR/J, and SJL/J mice were susceptible. An examination of F1 hybrids revealed that resistance was dominant over susceptibility. A segregation analysis of backcross and F2 progeny derived from susceptible A/J and resistant B10.A/SgSn parental mice suggested that host resistance in this strain combination was genetically controlled by a single, dominant, non-H-2-linked gene. Inheritance of resistance was autosomal, but expression of the trait was influenced by the sex of the host, female mice being more resistant than male mice. Phenotypic expression of the resistance gene was apparent within 6 days of infection as a significant difference between resistant and susceptible mice in the level of parasitemia. A preliminary analysis of the mechanism of resistance showed that compared with susceptible A/J mice, resistant B10.A/SgSn hosts had an augmented erythropoietic response during the course of malaria, as well as phenylhydrazine-induced anemia. These results suggest that the ability to replace destroyed erythrocytes quickly and efficiently may determine host survival after infection with P. chabaudi.
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PMID:Murine malaria: genetic control of resistance to Plasmodium chabaudi. 714 99

Murine graft versus host (GVH) disease takes two forms depending on the parental/F1 strain combination employed. In an accompanying paper (Singh et al., Clin. Immunol. 151, 1993) many of the clinical features of these two forms of GVH disease are described. In addition to these clinical characteristics, acute lethal GVH (ALGVH) disease is characterized by diminished natural killer cell activity, whereas chronic GVH disease is characterized by normal or increased natural killer cell activity. Previously we have reported that this marked disparity in disease expression can be attributed to radiosensitive host cells which protect the F1 mouse from parental anti-F1 cytotoxicity (CTX) in mice undergoing chronic GVH (CGVH) disease. These cells fail to functionally emerge in mice undergoing ALGVH disease. We now report that the background genome, presumably the minor lymphocyte stimulatory loci, of the donor cells determines whether these host cells emerge and thereby dictates the form of GVH disease which is induced. C57BL/6 (B6) cells (H-2b, minor lymphocyte stimulatory locus (Mls)b) and B10.D2 cells (H-2d, Mlsb) were found to induce ALGVH disease when adoptively transferred to [C57BL/6xDBA/2]F1 (B6D2) (H-2b/d, Mls-1a/b, Mls-2a/b) recipient mice. DBA/2 cells (H-2d, Mls-1a, Mls-2a) and Balb/c cells (H-2d, Mls-1a, Mls-2b) induced CGVH disease in B6D2 mice. Using Mls congenic strains we have demonstrated that donor cell reactivity against Mls-2a was necessary and sufficient to induce ALGVH disease as determined by anemia, lymphopenia, anti-F1 cytotoxicity, and loss of cytotoxicity against allogeneic targets. Such Mls-2a reactivity correlated with the impaired induction of a host protective cell capable of vetoing self-directed CTX. Failure of this host protective cell to emerge in turn correlated with donor anti-host CTX and the emergence of ALGVH disease.
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PMID:The host response in graft versus host disease. II. The emergence of host protective cells is in part determined by background genomic compatibility. 840 30

Injection of 10(6) immortalized, but non-leukemic, granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent FDC-P1 cells into GM-CSF transgenic hybrid mice with elevated GM-CSF levels led to death within three months with elevated blast cell numbers in the blood, massive organ infiltration by blast cells, and associated anemia and thrombocytopenia. No disease developed within this period in littermate mice injected with 10(6) FDC-P1 cells. All moribund transgenic recipients contained transformed FDC-P1 cells able to produce rapidly-growing transplanted leukemias in syngeneic normal DBA/2 recipients. The leukemias appeared to arise in the primary recipients by independent transformation events. The transformed cells from different mice differed in their in vitro growth characteristics, their ability to produce GM-CSF or multipotential CSF, and in the nature of the transplanted tumors derived from the primary cells. While all primary recipients at death contained fully transformed leukemic cells, the bulk of the large population of FDC-P1 cells appeared either to be untransformed or to have altered characteristics not yet representing full transformation. If the FDC-P1 engrafted model has some validity for myelodysplasia, the results suggest that sustained CSF administration to myelodysplastic patients possessing abnormal, potentially preleukemic, granulocyte-macrophage populations may increase the risk of death either from accumulated pretransformed or from fully transformed leukemic cells.
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PMID:Leukemic transformation of immortalized FDC-P1 cells engrafted in GM-CSF transgenic mice. 850 82


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