Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| hormones, chemicals and proviral gene expression as contributing factors during mammary carcinogenesis in c3h/stwi mice. | 1981 | 6265386 | |
| induction of type-c retrovirus by the tumor promotor tpa. | the tumor promotor 12-0-tetradecanoyl-phorbol-13-acetate (tpa) induced endogenous murine xenotropic type-c retrovirus from a1-2 cells, derived from the balb/c mouse, as determined by infectious center focus-forming assay on permissive normal rat kidney (nrk) cells. kinetic dose-response studies showed that the number of cells induced to release virus was dependent on tpa concentration and the time of assay following tpa exposure. maximal induction occurred when cells were treated with 80 ng/ml o ... | 1981 | 6265387 |
| lack of thy 1.2 antigen expression on the surfaces of mouse mammary epithelial cells. | monoclonal antisera against mouse thy 1.2 antigen were used to assess the expression of thy 1.2 antigen on balb/c and balb/cfc3h normal mouse mammary gland epithelial cells (mmec) and on spontaneous and transplanted balb/cfc3h mammary adenocarcinoma cells. immunofluorescence (if) assays with the monoclonal anti-thy 1.2 sera demonstrated that thy 1.2 antigen was not expressed on the surface membranes of mmec (both virus-free balb/c and virus-infected balb/cfc3h) and tumor (balb/cfc3h) mammary epi ... | 1981 | 6265679 |
| murine mammary tumor virus seroepidemiology in balb/cfc3h mice: correlation with tumor development. | serum reactivity to murine mammary tumor virus (mumtv) was inversely related to mammary tumor risk in 8-to 22-week-old balb/cfc3h breeding females. mice at low tumor risk exhibited high-titered serum reactivity to mumtv (50% end point, greater than or equal to 1:40 by radioimmunoassay) approximately 3-6 months earlier than did the mice at high tumor risk. maternal mumtv antibody levels were correlated with the serum anti-mumtv reactivity of their neonatal offspring (2 wk of age). serologic antiv ... | 1981 | 6265680 |
| chromatographic evidence that the aaa-coding isoacceptor of lysine trna primes dna synthesis in murine mammary tumor virus. | 1981 | 6266151 | |
| antibodies to mouse mammary tumor virus-related antigen in sera of patients with breast carcinoma. | sera from patients with breast carcinoma, benign breast disease, malignancies other than breast carcinoma, and healthy female controls were analyzed by indirect immunofluorescence for the presence of antibodies directed toward antigens of mouse mammary tumor. sera from 56 to 137 (40.9%) patients with breast carcinoma were positive. positive reactivity was also found in sera from 5 to 27 (18.5%) patients with benign breast disease, in 7 of 60 (11.7%) patients with malignancies other than breast c ... | 1981 | 6266639 |
| mammary tumorigenicities of three chemically induced mouse kidney cell lines in syngeneic female hosts. | three chemically induced, mammary tumour virus (mmtv) and leukemia virus (mulv) producing, baby mouse kidney (bmk) cell lines derived from respectively strains balb/c (-/hea and -/crgla) and c57bl/lia were investigated for their mammary tumour (mt) evoking potentials in syngeneic female hosts. an i.p. inoculated virus-enriched fraction from a3 cells (balb/c/hea) had a similar oncogenic effect as i.p. and s.c. inoculated whole a3 cells. the average mt ages were reduced in all 3 groups. cell lines ... | 1981 | 6266652 |
| integration and activity of mammary tumor virus genes: regulation by hormone receptors and chromosomal position. | 1981 | 6266760 | |
| enzymoimmunoassay of the main core protein (p28) of mouse mammary tumour virus (mmtv). | 1981 | 6266832 | |
| lymphoproliferative responses to mouse mammary tumor virus in lymphocyte subsets of breast cancer patients. | altered immunologic reactions were observed in breast cancer patients as compared to those in normal subjects. lymphoproliferative responses to murine mammary tumor virus (mumtv) were significantly enhanced in peripheral blood mononuclear cells from patients with metastatic disease. these reactivities occurred with mammary tumor virus purified from either mouse milk or infected feline kidney cells but not with rauscher murine leukemia virus. for the assessment of the role of peripheral blood mon ... | 1981 | 6267344 |
| mammary tumors from gr mice contain more than one population of mouse mammary tumor virus-infected cells. | 1981 | 6267780 | |
| immunological reaction between sera from neutron-irradiated w/fu rats and mouse mammary tumor virus. | sera from w/fu rats from the presence of anti mouse mammary tumor virus (mmtv) antibodies were examined by the use of an immunofluorescence (if) test and an immune adherence hemagglutination (iaha) test. sera from w/fu rats subjected to neutron irradiation or neutron irradiation followed by grafting of pituitary tumor (mtt) as a source of prolactin gave a positive if reaction with mouse mammary tumor cells (mmt) producing type-a and type-b virus particles. nine out of 20 (45.0%) sera from rats g ... | 1981 | 6268478 |
| purification and translation of murine mammary tumor virus mrna's. | we have studied the functions of the intracellular rnas of mouse mammary tumor virus (mmtv) by purification and translation in vitro. two major size classes of mmtv rna, 35s and 24s rna, were isolated from mmtv-infected rat (xc) cells and cultured mammary tumor cells by preparative hybridization of whole cell or polyadenylated rna to cloned mmtv dna covalently bound to chemically activated paper disks (diazobenzyloxymethyl paper). genomic-length (35s) rna was prepared free of 24s rna by rate zon ... | 1981 | 6268810 |
| mammary tumor virus proviral dna in normal murine tissue and non-virally induced mammary tumors. | the southern dna filter transfer technique was used to study the involvement of the endogenous mouse mammary tumor virus (mmtv) in the development of mammary tumors of nonviral etiology. the presence of extra mmtv proviruses in the genomes of these non-virally induced mammary tumors would indicate an integration of the provirus of an activated endogenous mmtv. acquisition of mmtv proviruses did not seem to be an absolute requirement for the development of hormone or carcinogenically induced mamm ... | 1981 | 6268828 |
| induction of endogenous mammary tumor virus expression during hormonal induction of mammary adenoacanthomas and carcinomas of balb/c female mice. | treatment of balb/c female mice with pituitary isografts, under conditions that established mammary hyperplasia in an anovulatory condition, enhanced mammary tumor development with prior onset of dysplastic foci in lobular parenchyma. tumor onset began at 8 months (mean onset time, 18 mo); the 25-month incidence was 100%. adenoacanthomatous tumors appeared first. adenocarcinomas appeared only after more than 14 months of continuous hormone stimulation. dysplastic and neoplastic changes occurred ... | 1981 | 6268884 |
| isolation and characterization of a new mouse mammary tumor virus from balb/c mice. | 1981 | 6269283 | |
| effect of the age-related immune depression induced by mtv on the in vivo growth of a mammary carcinoma. | 1981 | 6269570 | |
| quantitation of viral antigens released into plasma and culture fluids by murine mammary tumor cells. | radioimmunoassay capable of measuring mouse mammary tumor virus (mmtv) 52,000 m.w. envelope glycoprotein (gp52) and 27,000 m.w. protein (p27) have been used to quantitatively compare plasma concentrations of these viral antigens in mice bearing spontaneous mammary tumors. although gp52 was detected in the plasma of all tumor-bearing mice tested, p27 was detected in only a portion of tumor-bearing animals. in p27-positive animals, gp52 was detected in higher concentrations than p27. these finding ... | 1981 | 6269731 |
| cloned mouse mammary tumor virus dna is biologically active in transfected mouse cells and its expression is stimulated by glucocorticoid hormones. | we have cloned circular unintegrated mouse mammary tumor virus (mmtv) dna from infected rat hepatoma cells in bacteriophage lambda. seven independent clones containing mmtv dna of homogeneous length of 9 kb (five) or 10 kb (two) were identified. the five 9 kb clones had identical restriction maps consistent with that of 9 kb unintegrated dna; the other two were aberrant. mmtv dna inserts were purified, ligated and used for cotransfection of ltk- cells together with a plasmid containing the thymi ... | 1981 | 6258799 |
| common surface receptors on both mouse and rat cells distinguish different classes of mouse mammary tumor viruses. | 1981 | 6259809 | |
| characterization of a variant-producing tumor cell line from a heterogeneous strain balb/cfc3h mouse mammary tumor. | 1981 | 6260334 | |
| changes in retrovirus expression in mouse mammary tumor cells in culture. | mouse mammary tumor cells (mm5mt/c1) produced mouse mammary tumor virus (mmtv) (type b retrovirus) at early passages in culture. they apparently produced predominently type c retrovirus(es) at late passages in culture. the decline in mmtv production during passage was not accompanied by an apparent decrease in the synthesis or accumulation of intracellular mmtv-specific rna. as judged by the concentration of rna (mol/titer) x half-time (sec) of hybridization of cellular rna with mmtv complementa ... | 1981 | 6260345 |
| mammary tumor induction loci in gr and dbaf mice contain one provirus of the mouse mammary tumor virus. | the mammary tumor induction genes mtv-1 in mouse strain dbaf and mtv-2 in strain gr control the complete expression of the endogenous mouse mammary tumor virus (mmtv). we have used a combination of genetic, biochemical and molecular biological methods to identify and correlate specific copies of the endogenous mmtv proviral genes with the biological properties of the tumor induction genes mtv-1 and mtv-2. these mtv induction genes contain specific mmtv proviral information, as was concluded from ... | 1981 | 6260372 |
| precursor product relationship between intracytoplasmic a particle and murine mammary tumor virus core proteins established by tryptic peptide analysis. | 1981 | 6258309 | |
| subset of spleen lymphocytes from balb/ccrgl mice stimulated by mouse mammary tumor virus. | lymphocytes from balb/ccrgl mice react to mouse mammary tumor virus-associated antigen(s) when tested in in vitro blastogenic transformation assays. these mice have a low incidence (less than 1%) of spontaneous mammary tumors and are free from complete mammary tumor virions. we have studied the nature of the lymphoid cells mediating the lymphocyte transformation reaction to purified mammary tumor virus. with the use of nylon wool columns, the responder cells were found to belong to the nylon-adh ... | 1981 | 6257384 |
| immunological characterization of a mammary tumour virus from swiss mice: multiple epitopes associated with the viral gene products. | the major antigens of a mouse mammary tumour virus (mmtv) isolated from the milk of exogenously infected mb+ swiss mice were compared with the viral components of other mmtv strains by using the methodology developed by teramoto et al. (1977 a). the anti-gp47 (swiss) serum differentiated between type- and group-specific antigenic determinants on the major glycoprotein; two distinct type-reactivities were demonstrated, one of them being shared by the mmtvs (swiss) and (riii), and the other by the ... | 1981 | 6172552 |
| monoclonal antibodies as immunospecific probes for virus and cell surface antigen localization with the unlabeled antibody hemocyanin bridge: a review. | hemocyanin (hcy) from whelks, busycon canniculatum has been developed as a visual marker for the identification of virus and cell surface antigens by the correlative techniques of fluorescence microscopy, tem and sem. a series of hybridomas producing monoclonal antibodies that allow the identification of type-, group-, and class-specific antigenic determinants on the major envelope glycoprotein of mouse mammary tumor virus (mmtv) gp 52 and two group-specific monoclonal antibodies to mmtv gp 36 h ... | 1981 | 6172845 |
| selection of rat hepatoma cells defective in hormone-regulated production of mouse mammary tumor virus rna. | we have been studying the mechanism of glucocorticoid hormone action by using mouse mammary tumor virus (mmtv)-infected rat hepatoma cells as a model system. j2.17, a clonal cell line that contains one mmtv provirus, induces tyrosine aminotransferase (tyratase; l-tyrosine:2-oxoglutarate aminotransferase, ec 2.6.1.5), viral rna, and the cell surface viral glycoprotein gp52 in response to dexamethasone. using a fluorescence-activated cell sorter and a rabbit antiserum directed against gp52, we sel ... | 1981 | 6117075 |
| co-expression and amplification of dihydrofolate reductase cdna and the escherichia coli xgprt gene in chinese hamster ovary cells. | we have transformed chinese hamster ovary cells with a plasmid containing mouse dihydrofolate reductase (dhfr) cdna and the escherichia coli xanthine-guanine phosphoribosyl transferase (xgprt) gene under the control of the mouse mammary tumor virus and sv40 early promoters, respectively. selection for the expression of xgprt using the dominant selection scheme described by mulligan and berg yields clones that simultaneously express dhfr. growth of these cells in progressively increasing concentr ... | 1981 | 6180118 |
| antigens and antibodies cross-reactive to the murine mammary tumor virus in human breast cyst fluids. | human breast cyst fluids were shown to contain low concentrations of iga (15-78 micrograms/ml) and igg (33-145 micrograms/ml). the iga:igg ratios in individual breast cyst fluids ranged from 1:0.6 to 1:4. these levels are considerably higher than their ratio in serum (1:7). iga from 33% of the 40 fluids examined, and igg from 10% of the fluids, reacted with the murine mammary tumor virus (mumtv). the reactivity was detected by an enzyme-linked immunosorbent assay that measures antibody binding t ... | 1981 | 6256413 |
| kinetics of responses to tumor antigens and mouse mammary tumor virus in balb/ccrgl and balb/cfc3h mice. | spleen cells from balb/ccrgl mice responded to murine mammary tumor virus (mumtv) in cell-mediated immune assays at higher levels than did the spleen cells from the syngeneic balb/cfc3h mice. implantation in balb/ccrgl with a chemically induced mammary tumor and in balb/cfcrgl mice with spontaneous mammary tumors (smt) arising in the same strain resulted in sensitization of these animals to the antigens of their tumors. reactivities peaked 3 weeks after transplantation, whereas no positive react ... | 1981 | 6256573 |
| development, morphology, and progression of mammary tumors during and after fertile life in balb/cfriii mice. | a study was done on 368 balb/cfriii mammary tumor-bearing breeding female mice that are of the balb/c genotype and carry milk-transmitted riii murine mammary tumor virus (mumtv) infection initiated by foster-nursing. all tumors were characterized by chronologic, biologic, and morphologic analyses. mammary tumors occurring during pregnancy-lactation periods were mostly pregnancy-dependent plaques showing organoid tubular structure, sudden growth during late pregnancy, regression after delivery, a ... | 1981 | 6256576 |
| nucleotide sequences at host-proviral junctions for mouse mammary tumour virus. | proviruses cloned from rat cells infected with mouse mammary tumour virus, a b-type retrovirus regulated by glucocorticoid hormones, show the structural features of transposable elements: short inverted repeats conclude long direct repeats at the ends of viral dna, and short sequences of cellular dna are duplicated during integration and flank each provirus. the integrative mechanism joins a precise site in viral dna to non-homologous sites in host dna. | 1981 | 6256658 |
| protein a assay for mouse mammary tumor virus gp52 determinants on murine and human mammary tumor cells. | 1981 | 6166119 | |
| sequence determination of the 3' end of mouse mammary tumor virus rna. | 70s rna has been prepared from mouse mammary tumor virus (mmtv) produced by the gr tumor cell line. after denaturation for 3 min at 60 degrees c the rna was applied to a sucrose gradient and molecules sedimenting between 10-16s were selected and passed over an oligo-dt cellulose column. the poly a containing rna fraction was used as a template for the synthesis of complementary dna with reverse transcriptase in the presence of dideoxynucleoside triphosphates. oligo-nucleotides p(dt)7rg, p(dt)7ra ... | 1981 | 6166850 |
| interferon-mediated inhibition of mouse mammary tumour virus (type b) and mouse leukaemia virus (type c) in the same culture. | the sensitivity of mouse mammary tumour virus (mmtv) and murine leukaemia virus (mulv) to interferon was tested by investigating the effect of interferon in cultures of mouse mammary tumour cells simultaneously synthesizing the two viruses. the dose-response curves showed that the extracellular production of both viruses by these cells was equally inhibited by interferon treatment. in contrast, the intracellular steady-state concentration of virus-specific rna of both mmtv and mulv was not signi ... | 1981 | 6167668 |
| [hormone-dependent expression of oncovirus genomes in stable mouse mammary cancer cell line gr and riii]. | the expression of mumtv and mulv major polypeptides and extracellular revertase activity (ra) in relation to the treatment with insulin (ins), dexamethasone (d) or both hormones was studied in four clones derived from two mammary carcinoma (mc) stable cell lines, riii/mt and gr/mt. in the cells growing in media without hormonal supplementation or with either insulin or dexamethasone alone the expression of p27 mumtv was poor, in cultures treated with dexamethasone alone a slight increase in mg++ ... | 1981 | 6168117 |
| use of the immune adherence hemagglutination test for titration of breast cancer patients' sea cross-reacting with purified mouse mammary tumor virus. | ninety-two sera from patients with breast cancer, 42 sera from patients with neoplastic diseases other than breast cancer and 59 sera from apparently healthy women were examined by means of the immune adherence hemagglutination (iaha) test using purified mouse mammary tumor virus (mmtv) fron rii mouse milk. it was found that 36.4% (34/96) of the sera from breast cancer patients, 7.1% (3/42) of the sera from patients with other neoplastic diseases and 5.1% (3/59) of the sera from apparently healt ... | 1981 | 6168514 |
| immunological characterization of a low oncogenic mouse mammary tumor virus balb/cniv mice. | antigenic determinants of mouse mammary tumor virus (mumtv) from the low-mammary-tumor-incidence strain balb/cniv were compared by competition radioimmunoassay with those of mumtv's isolated from several high- and low-mammary-tumor-incidence mouse strains, using rabbit hyperimmune sera against balb/cniv mumtv and against mumtv from the high-mammary-tumor-incidence strain balb/cfc3h. using anti-balb/cfc3h serum in competition radioimmunoassay, balb/cniv mumtv lacked antigenic determinants present ... | 1981 | 6169849 |
| topographical analysis of viral epitopes using monoclonal antibodies: mechanism of virus neutralization. | 1981 | 6170162 | |
| [possible association between oncoviruses and human breast tumors]. | 1981 | 6170188 | |
| dexamethasone effect on the growth rate, the plasminogen activator, and the mmtv rna dependent dna polymerase in a mouse mammary tumor cell line. | 1981 | 6171281 | |
| type-specific determinants on proteins of an endogenous c3h mouse mammary tumor virus (mmtv) distinguish this virus from highly oncogenic exogenous mmtvs. | 1981 | 6164153 | |
| progressive growth of transplanted tumors is accompanied by increasing serum concentrations of murine gamma fetal antigen. | balb/c mice bearing growing meth a sarcomas developed gradually increasing serum concentrations of the tumor-associated murine gamma fetal antigen (gamma-fa), a trend which could be reversed by surgical excision of the tumor tissue. this antigen was not detected in the sera of normal adult mice or in the sera of animals with non-neoplastic proliferative condition. although gamma-fa occurs in splenic tissue, its concentration in tumor-bearer serum was unaffected by splenectomy suggesting that gam ... | 1981 | 6795603 |
| effects of interferon on the expression of mouse mammary tumour virus in gr cells. | the effects of interferon treatment on the expression of murine mammary tumour virus (mumtv) by a continuous mammary tumour cell line of gr mouse were investigated. interferon markedly inhibited the excretion of mumtv particles in the culture media as measured by hybridization of virus-specific rna and virus-associated reverse transcriptase activity. there was no inhibition of virus rna and protein synthesis in those conditions. the steady-state level of intracellular virus rna and its rate of s ... | 1982 | 6182267 |
| dependence of the structural mumtv protein expression on hormone-induced murine mammary carcinoma gr/mt cell differentiation in vitro. | effect of three hormones on the clonal cell line, originating from the stable gr/mt mammary carcinoma (mc) cell line was studied. in the hormones free media the cells had fibroblast-like shapes. normal differentiation markers and mumtv protein processing could not be revealed. insulin favors epithelial cell shape and growth pattern induction, thy 1.2 antigen expression, as it was shown by fif test and increased clonogenicity in semisolid medium. prolactin produces elongated, fusiform cells, milk ... | 1982 | 6184623 |
| detection of type-specific antigenic determinants of murine mammary tumor viruses with cell-mediated immune assays. | 1982 | 6174985 | |
| the use of monoclonal antibodies in virology. | 1982 | 6177742 | |
| ml antigen of dba/2 mouse leukemias: expression of an endogenous murine mammary tumor virus. | spontaneous, transplantable leukemias of dba/2 mice express an antigen (ml) which cross-reacts with antigens of murine mammary tumor virus (mumtv). the mumtv cross-reactive antigen of the dba/2 leukemias (ml cells) was found to be a glycoprotein of 78,000 molecular weight containing antigenic determinants of the major mumtv glycoprotein gp52. no mumtv particles were produced by the ml cells, although they did contain type a particles--the pronucleocapsids of mumtv. the ml antigen appeared to be ... | 1982 | 6178848 |
| monoclonal and polyclonal antibody studies of vsv(hrmmtv) pseudotypes. | 1982 | 6179293 | |
| diagnosis of primary breast carcinoma through immunohistochemical detection of antigen related to mouse mammary tumor virus in metastatic lesions: a report of two cases. | recent investigations have established that approximately half of human breast carcinomas contain an immunohistochemically detectable antigen which is cross-reactive with the 52000-dalton major glycoprotein (gp52) of the mouse mammary tumor virus (mmtv). this antigen can be localized in paraffin-embedded sections of routinely fixed tissues using heterologous antibodies to gp52 or mmtv. this report describes two patients with metastatic carcinoma in axillary lymph nodes without any clinical evide ... | 1982 | 6274506 |
| role of natural prostaglandins in the control of murine mammary tumor virus expression. | the regulation of murine mammary tumor virus (mumtv) production by mammotropic hormones, hormonomimetic substances, and cyclic nucleotides was investigated. the virus produced in control and treated mammary tumor cell cultures was quantitated by measuring the supernatant reverse transcriptase activity in exogenous reaction using poly(rc).oligo(dg) as template-primer. two days after exposure, the synthetic glucocorticoid, dexamethasone (dxmt), increased spontaneous mumtv production at optimal con ... | 1982 | 6281284 |
| processing and amino acid sequence analysis of the mouse mammary tumor virus env gene product. | the envelope proteins of mouse mammary tumor virus (mmtv) are synthesized from a subgenomic 24s mrna as a 75,000-dalton glycosylated precursor polyprotein which is eventually processed to the mature glycoproteins gp52 and gp36. in vivo synthesis of this env precursor in the presence of the core glycosylation inhibitor tunicamycin yielded a precursor of approximately 61,000 daltons (p61env). however, a 67,000-dalton protein (p67env) was obtained from cell-free translation with the mmtv 24s mrna a ... | 1982 | 6281457 |
| mouse mammary tumor virus dna sequences in tumorigenic and nontumorigenic cells from a mammary adenocarcinoma. | 1982 | 6281965 | |
| retroviruses in feral mice. | 1982 | 6282773 | |
| circulating immune complexes, antigens, and antibodies related to the murine mammary tumor virus in c3h mice. | 1982 | 6282972 | |
| detection of acquired provirus sequences in mammary tumors from low-expressor, low-risk mice. | murine mammary tumor virus (mumtv) provirus sequences in the dna from early-occurring (average age 10 mo) and late occurring (age greater than 20 mo) tumors in balb/cfc3h mice were analyzed by eco ri restriction endonuclease mapping procedures. all early tumors were mumtv antigen-positive mammary adenocarcinomas that contained the 0.92- and 4.0-kilo base (kb) exogenous c3h mumtv-specific pst i restriction endonuclease fragments. all but 1 of the late mammary adenocarcinomas had mumtv antigens de ... | 1982 | 6283224 |
| cell-mediated immunity to mouse mammary tumor virus antigens by patients with hyperplastic benign breast disease. | peripheral blood leukocytes of patients with preoperative breast cancer, benign breast disease, and benign gynecologic disorders and normal healthy females were tested, as blind coded specimens, with murine mammary tumor virus (mumtv) antigens in the direct and indirect leukocyte migration inhibition (lmi) assays. the incidence of reactivity by patients with breast cancer was low. (from 5 to 35% breast cancer patients reacted, depending on which group of control individuals they were compared to ... | 1982 | 6283226 |
| possible related risks to breastfeeding. | animal studies have identified a mouse mammary tumor agent transmitted through lactation that increases the incidence and reduces the age for tumor development in offspring. a similar viral particle has been detected with greater frequency in the milk of humans with a family history of breast carcinoma than in the milk of those with no history. animal studies also indicate that a male offspring who has been breastfed, at low risk himself, could possibly transmit the agent through seminal fluid. ... | 1982 | 6283228 |
| separation of high mammary tumor incidence from high hepatoma incidence in backcross mice during segregation of the viable yellow gene. | 1982 | 6284658 | |
| suppression of spontaneous mammary tumorigenesis despite mtv-1 gene expression in hybrid and backcross c3h-avyfb x c3h/sm mice. | 1982 | 6284659 | |
| methylation and amplification of mouse mammary tumor virus dna in normal, premalignant, and malignant cells of gr/a mice. | the methylation and amplification of mouse mammary tumor virus (mumtv) proviral dna was investigated in normal, premalignant, and malignant tissues of gr/a mice. the proviral methylation pattern was examined with the restriction enzyme hhai, which fails to cleave methylated dna. mumtv proviral dna from liver, kidney, and heart was highly methylated. proviral dna was somewhat undermethylated in mammary gland cells from virgin and lactating mice and extensively undermethylated in cells from premal ... | 1982 | 6284957 |
| dna sequence relationship of the baboon endogenous virus genome to the genomes of other type c and type d retroviruses. | baboon endogenous virus (baev) is a type c retrovirus present in multiple proviral copies in the dna of baboons. although interspecies antigenic determinants present on reverse transcriptase and gag proteins are shared among all mammalian type c viruses, no nucleic acid homology between baev and other type c viruses (except rd-114) has been found in conventional liquid hybridization experiments. in this study, we used restriction fragments of cloned baev dna immobilized on nitrocellulose to test ... | 1982 | 6284972 |
| restriction endonuclease mapping of the proviral dna of the exogenous riii murine mammary tumor virus. | cellular dna containing integrated murine mammary tumor virus (mumtv) was isolated from fei/c6 feline kidney cells and ccl64 mink lung cells infected with milkborne riii mumtv. by using restriction enzyme hpai, intact riii mumtv provirus (length, 8.7 kilobases [kb]) was excised from the cellular dna. subsequent restriction endonuclease analysis of this hpai fragment with kpni, hindiii, ecori, bamhi, bglii, psti, ssti, sali, and xhoi enabled us to construct a map of the riii virus genome. a compa ... | 1982 | 6284976 |
| conservation of protein coding potential in the long terminal repeats of exogenous and endogenous mouse mammary tumor viruses. | in vitro protein synthesis and dna sequence analysis indicate that mouse mammary tumor virus differs from other well-characterized retroviruses in that the long terminal repeat region of the provirus has the capacity to encode proteins. different exogenously transmitted mouse mammary tumor virus strains and endogenous proviral units conserved this open reading frame feature in the long terminal repeat despite a variation in nucleotide sequence. the proteins encoded by the different long terminal ... | 1982 | 6285002 |
| identification of an antigen associated with transforming genes of human and mouse mammary carcinomas. | sera from tumor-bearing mice immunoprecipitated a 86,000-dalton glycoprotein from extracts of nih cells transformed by human mammary carcinoma dna. this antigen was not immunoprecipitated from extracts of nih 3t3 cells, spontaneously transformed nih cells, nih cells transformed by normal human dna, nih cells transformed by human bladder carcinoma dna, or nih cells transformed by rous sarcoma virus dna. in addition, sera from mice bearing tumors induced by nih cells transformed by either normal h ... | 1982 | 6285346 |
| sera from breast cancer patients contain an iga antibody to a breast cyst fluid component. | 1982 | 6286196 | |
| radioimmunoassay for major external glycoprotein of murine mammary tumor virus. | 1982 | 6286471 | |
| identification of a unique mouse mammary tumor virus in the balb/cniv mouse strain. | we examined the genetic structure, in terms of restriction endonuclease recognition sites, of the milk-transmitted, low-oncogenic mouse mammary tumor virus (mumtv) of the balb/cniv mouse strain. an analysis with ecori documented the presence of acquired cniv proviruses in the mammary tumor dnas of balb/cniv animals. a comparison of tumor dnas digested with psti showed that both the cniv mumtv and c3hf mumtv proviruses lacked the 4.3- and 1.1-kilobase pair fragments characteristic of c3h mumtv pa ... | 1982 | 6286994 |
| a high-tumor-incidence subline of the d1 mouse mammary hyperplastic outgrowth line: effect of carcinogens. | mammary tumorigenesis in some mouse strains is characterized by the appearance of a preneoplastic lesion, the hyperplastic alveolar nodule (han). the biology of the han has been characterized primarily through the study of stable outgrowth lines of serially transplanted han. one outgrowth line, dl, which was developed and carried in female balb/c mice, has been described as a low-tumor-incidence line that does not express murine mammary tumor virus (mumtv) and is susceptible to hormonal, chemica ... | 1982 | 6287083 |
| comparison of mammary tumorigenesis between litters in relation to mammary tumor virus antigenic expression in the milk of c3h/he mice. | as a possible step to estimate the relationship between mammary tumor virus (mtv) and mammary tumorigenesis in mice, mtv antigenic expression in mother's milk and spontaneous mammary tumorigenesis in their daughters were compared between the 1st, the 2nd and the 3rd litters of the highly inbred strains of c3h/h3 mice with low mammary tumor incidence. while mtv antigenic expression was detected in all undiluted samples at each litter by immunodiffusion test, the amount of antigen as measured by t ... | 1982 | 6287151 |
| novel class of mouse mammary tumor virus-related dna sequences found in all species of mus, including mice lacking the virus proviral genome. | mice in breeding colonies of feral mus musculus brevirostris (azrou, morocco), m. m. musculus (studenec, czechoslovakia), and m. m. molossinus (fukuoka, japan) were found to lack the mouse mammary tumor virus (mmtv-alpha) proviral genome in their germ line. mmtv-alpha proviral genomes have been found in all inbred strains of m. musculus by using high-stringency nucleic acid hybridization conditions. we conclude that feral mice in these colonies are heterozygous for a limited number of mmtv-alpha ... | 1982 | 6287466 |
| dna mediated transfer and fate of a proviral gene of mouse mammary tumor virus in cultured cells. | 1982 | 6287482 | |
| chromosomal position effects determine transcriptional potential of integrated mammary tumor virus dna. | 1982 | 6288960 | |
| altered methylation of endogenous viral promoter sequences during mammary carcinogenesis. | 1982 | 6276763 | |
| long terminal repeats of endogenous mouse mammary tumour virus contain a long open reading frame which extends into adjacent sequences. | 1982 | 6276778 | |
| mammary tumor virus dna as a marker for genotypic variance within hormone-responsive gr mouse mammary tumors. | mammary tumors of gr mice acquire extra mammary tumor virus (mmtv) dna information within their dna during tumor growth and development. these extra mmtv genes have been used by us as genotypic markers to investigate the heterogeneity of gr mammary tumors and their loss of hormone dependence during serial transplantation. our studies reveal that the various subpopulations of cells within individual gr mammary tumors are characterized by differences in number and location of acquired extra mmtv d ... | 1982 | 6277477 |
| a viral antigen as a marker for the prognosis of human breast cancer. | an antigen present in human breast tumor cells, and which is immunologically related to the envelope protein (gp52) of murine mammary tumor virus, was used as a marker for the detection of breast cancer in an israeli population. the results show that the antigen was detectable in 128 of 204 breast carcinomas tested (62.7%). the immunological reaction was not detected in normal breast tissue, benign breast tumors, ductal hyperplasia or in primary malignancies in other organs. a significantly high ... | 1982 | 6299750 |
| signals governing mouse mammary tumor virus expression in vivo and in cultured cells upon proviral dna transfer. | 1982 | 6300919 | |
| multiple specific binding sites for purified glucocorticoid receptors on mammary tumor virus dna. | glucocorticoid hormones selectively stimulate the rate of transcription of integrated mammary tumor virus (mtv) sequences in infected rat hepatoma cells. using two independent assays, we find that purified rat liver glucocorticoid receptor protein binds specifically to at least four widely separated regions on pure mtv proviral dna. one of these specific binding domains, which itself contains at least two distinct receptor binding sites, resides within a fragment of viral dna that maps 110-449 b ... | 1982 | 6296168 |
| unconventional application of standard light and electron immunocytochemical analysis to aldehyde-fixed, araldite-embedded tissues. | a simple procedure for the immunocytochemical analysis of glutaraldehyde/formaldehyde-fixed, araldite- or epon-embedded tissues by either light or electron microscopy is presented. retention of immunoreactive antigen in deplasticized sections was achieved by use of a low concentration of glutaraldehyde in the fixative in combination with a seldom-used plastic solvent. this protocol produced good ultrastructural preservation in tissues and large, high-quality, 2-micrometers thick, plastic-free se ... | 1982 | 6296221 |
| low-calorie diet prevents the development of mammary tumors in c3h mice and reduces circulating prolactin level, murine mammary tumor virus expression, and proliferation of mammary alveolar cells. | the effect of carlorie intake on the development of spontaneous mammary tumors in virgin c3h mice was studied. only about 10% of the mice fed a low-calorie diet [10 kcal/day (1 kcal = 4.184 kj)] since weaning developed mammary tumors, compared to about 60% of those mice that were reared on high-calorie diets (16 kcal/day or lab chow ad lib). in order to understand the mechanism by which a low-calorie diet decreases the occurrence of mammary tumors in mice, we compared the sex cycle, the amounts ... | 1982 | 6296850 |
| a comparison of nucleoside (beta-s)triphosphates and nucleoside (gamma-s)triphosphates as suitable substrates for measuring transcription initiation in preparations of cell nuclei. | rna chains initiated with nucleoside (beta-s)triphosphates and (gamma-s)triphosphates retain the thiol groups and can be separated from thiol-free rna by chromatography on mercury-sepharose. thiol-containing mouse mammary tumor virus (mmtv) rna synthesized by preparations of nuclei from virus-infected cells was quantitated by nucleic acid filter hybridization. with atp beta s and gtp beta s, region-specific initiation of mmtv rna chains was detected in the cell free system. however, with atp gam ... | 1982 | 6298716 |
| effects of long term exposure to beer on the genesis and development of spontaneous mammary adenocarcinoma and prolactin levels in female virgin c3h/st mice. | the exposure of female inbred virgin c3h/st mice infected with the bittner particle to a commercial brand of beer increases body weight but has no significant effects on survival, the incidence of spontaneous mammary adenocarcinoma, tumor latency, or growth even on continuous administration of beer in place of drinking water over the entire postweaning lifespan of the animals. prolactin excretion in young beer-group mice was slightly elevated but not significantly different from the prolactin le ... | 1982 | 6309941 |
| simple sandwich enzyme immunoassay for quantification of mouse mammary tumor virus in mouse milk. | we have developed a sandwich enzyme immunoassay in order to measure quantitatively mouse mammary tumor virus (mmtv) in mouse milk. in this assay, the antibody-beta-d-galactosidase complex and antibody-bound silicon rubber pieces pieces as solid phase are used. the assay is able to detect 10 ng/ml of mmtv in the milk sample. | 1982 | 6290029 |
| heterogeneity of expression and induction of mouse mammary tumor virus antigens in mouse mammary tumors. | seven spontaneous balb/cfc3h mouse mammary tumors were heterogeneous in expression of murine mammary tumor virus-associated cell surface antigens. to determine the basis of this heterogeneity, cells from spontaneous tumors and from five subpopulations isolated from a single spontaneous tumor were examined for expression of viral antigens under both conventional conditions and conditions known to induce synthesis of murine mammary tumor virus antigens (5-iodo-2'-deoxyuridine and dexamethasone). i ... | 1982 | 6290031 |
| strain-specific differences of the major structural proteins of murine mammary tumour virus. | 1982 | 6290376 | |
| accelerated appearance of chemically induced mammary carcinomas in obese yellow (avy/a) (balb/c x vy) f1 hybrid mice. | latent periods and cumulative incidence of mammary carcinomas (mt) up to 50 wk after initial gavage with 7.12-dimethylbenz[a]anthracene (dmba) were determined in virgin yellow (avy/a) and agouti (a/a) (balb/cstcrlfc3hf/nctr x vy/wffc3hf/nctr-avy) f1 hybrid female mice. when subcutaneous masses reached 5-10 mm in diameter, the mice were killed and necropsied, and the tissues examined histologically. no mt were found in control mice. cumulative mt incidence in the 1.5-mg dmba group (a) was 43% (41 ... | 1982 | 6290678 |
| purified glucocorticoid receptor-hormone complex from rat liver cytosol binds specifically to cloned mouse mammary tumor virus long terminal repeats in vitro. | purified glucocorticoid hormone-receptor complex (hrc) from rat liver binds to specific dna sequences contained in cloned mouse mammary tumor virus (mmtv)dna. the binding site of the hormone-receptor complex is located in the long terminal repeat (ltr) of mmtv dna as shown by filter binding studies with labeled restriction fragments and by visualization of dna-receptor complexes with the electron microscope. the dnas from cloned mmtv lacking the ltr sequences were neither retained on nitrocellul ... | 1982 | 6291027 |
| detection and cloning of human dna sequences related to the mouse mammary tumor virus genome. | sequences related to the mouse mammary tumor virus (mmtv) genome have been detected in fragments of restricted human cellular dna. these results were obtained by using recombinant dna containing the mmtv proviral genome and lowering the stringency of blot-hybridization conditions. the mmtv genome also reacts with unique families of fragments in restricted cellular dna from other mammalian species but not with salmon sperm dna. a clone that reacted with labeled mmtv proviral dna was selected from ... | 1982 | 6291047 |
| relationships between morphology and viral etiology in mammary tumors of balb/cfc3h and balb/cfriii mice. | the morphologic pattern of mammary tumors induced by milk-transmitted c3h and riii murine mammary tumor viruses (mumtvs) in balb/c hosts infected by foster nursing were investigated further an compared taking into account several tumor and host variables. comparison of balb/cfc3h and balb/cfriii mammary tumors under identical tumor and host conditions showed highly significant differences in subgross morphology and histologic structure. differences in cytology were also observed. data suggest th ... | 1982 | 6291203 |
| [hormone-dependent process of the maturation of the major structural proteins of the mouse mammary tumor virus]. | the following findings were obtained by the radio-immunoprecipitation method with antisera to gp52 and p27. when the cells were cultivated in a hormone-free medium, they contained precursors of proteins of gene gag (pr 73gag) and gene evn (gpr 70env). no mature structural mtv proteins were found. the addition of insulin to the growth medium had no effect on maturation of protein precursors. when dexamethazone was added to the medium, gpr 70env "maturated" to gp52 of the main envelope glycoprotei ... | 1982 | 6280389 |
| radioimmunolocalization of murine mammary tumor virus proteins in gels. | 1982 | 6280511 | |
| abrogation of infectivity of mouse mammary tumor virus by reserpine. | 1982 | 6281054 | |
| mumtv antigen expression and mammary tumor incidence in non-inbred dd mice. | the expression of mammary tumor virus (mtv) antigen in the milk and various organs of three non-inbred dd mouse stocks (ddo, ddn and ddy) was examined by the immunodiffusion (id) and micro-immunodiffusion (micro-id) tests. the rate of mtv antigen expression in the milk was 100% at the first lactation in ddo (6/6) and ddn mice (10/10), and 23% in ddy mice (3/13). mammary tumor incidence was 13% (mean tumor age: 12.0 months), 32% (9.6 months) and 10% (11.5 months) in ddo, ddn and ddy mice, respect ... | 1982 | 6291954 |
| mouse mammary tumour virus and polyoma virus information in mammary tumours of athymic mice inoculated with polyoma virus. | polyoma virus inoculation of athymic mice results in the development of mammary tumours with a much higher incidence than the development of salivary gland tumours, the latter being the most common for immunocompetent normal mice. the possibility existed that polyoma virus might act as a co-carcinogen in activating the expression of mouse mammary tumour virus (mmtv). molecular hybridization studies, however, showed that the mammary tumour development was accompanied by neither the amplification ... | 1982 | 6292336 |
| in situ hybridization: general infectivity assay for retroviruses. | we have devised a general infectivity assay for retroviruses. a virus-specific [32p]dna probe is hybridized in situ to a monolayer culture, and foci of infected cells in the monolayer are detected by exposure of the hybridized culture to x-ray films. the method is quantitative, in that it gives the same titer for moloney murine leukemia virus as does the standard uv-xc test. the specificity of the assay is indicated by the fact that murine leukemia virus and baboon endogenous virus do not cross ... | 1982 | 6292448 |
| acquisition of proviral dna of mouse mammary tumor virus in thymic leukemia cells from gr mice. | male mice of strain gr develop t-cell leukemia at a low frequency late in life. these leukemia cells contain large amounts of mouse mammary tumor virus (mmtv) rna and mmtv proteins in a precursor form (nusse et al., j. virol. 32:251-258, 1979). we used restriction enzyme analysis and molecular hybridization to identify mmtv proviruses in the dna of these leukemia cells. gr leukemia cells contained additional integrated mmtv proviruses at various sites in the genome. this amplification of mmtv pr ... | 1982 | 6292463 |
| mouse mammary tumor virus proviral sequences congenital to c3h/sm mice are differentially hypomethylated in chemically induced, virus-induced, and spontaneous mammary tumors. | c3h/sm mice have lost the exogenous milk-borne mouse mammary tumor virus (mmtv) characteristic of the c3h strain and have a very low (1.5%) incidence of spontaneous mammary tumors, yet they are highly susceptible to mammary carcinogenesis by either chemical carcinogens or infection with the milk-borne virus. we have analyzed the mmtv proviral dna content of normal tissues and of spontaneous, virus-induced, and chemically induced mammary tumors by restriction endonuclease digestion and southern b ... | 1982 | 6292467 |
| analysis of lymphoid cells responding to virus- and tumor-associated antigens in spleens of syngeneic mouse mammary tumor systems with low and high oncogenic potentials. | 1982 | 6292565 |