Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| 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 |
| 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 |
| interaction between host and viral genomes in mouse mammary tumors. | 1982 | 6297374 | |
| specific binding of the glucocorticoid-receptor complex to the mouse mammary tumor proviral promoter region. | to elucidate the molecular mechanism by which steroid hormones exert their regulatory function, we investigated the interaction of a glucocorticoid-receptor complex with purified dna fragments from cloned mouse mammary tumor (mmtv) proviral dna. with a dna-cellulose binding assay, rat and mouse glucocorticoid receptors were found to interact with a high affinity site or sites in or near the promoter region of the mmtv proviral dna. the assay allowed the use of unpurified as well as purified rece ... | 1982 | 6297768 |
| [is the regulation of the expression of mmtv proviruses in various cell types linked to glucocorticoid receptors and/or the structure of chromatin?]. | the expression of the mouse mammary tumor virus (mmtv) was studied in undifferentiated embryonal carcinoma cells (ec), in partially differentiated myoblasts derived from ec cells and in fully differentiated myotubes. whereas no mmtv rna could be detected in ec cells, relatively large amounts of tumor virus rna were found in myoblasts. the mmtv rna level was reduced in myotubes derived from myoblastic differenciation. dnasei sensibility of mmtv dna in chromatin allows us to show conformational ch ... | 1982 | 6303198 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 | |
| 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 | |
| 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 |
| 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 |
| 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 |
| abrogation of infectivity of mouse mammary tumor virus by reserpine. | 1982 | 6281054 | |
| 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 |
| 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 | |
| kinetics of the reactivity of subpopulations of spleen cells of mice bearing virus-induced mammary tumors to syngeneic antigenic extracts in vitro. supportive and suppressive effects of macrophages. | this study was designed to investigate the nature of lymphocyte reactivity to soluble tumor antigens with respect to the kinetics of the reactivity, the responding cell type, and the role of accessory cells, within a syngeneic system. balb/c mice were inoculated with 1 x 10(6) viable cells of syngeneic mtv-induced mammary tumors. assessment of proliferative activity of spleen cells of these animals by dna synthesis (3h-thymidine incorporation in vitro) indicated a biphasic response to stimulatio ... | 1982 | 6297714 |
| many tumors induced by the mouse mammary tumor virus contain a provirus integrated in the same region of the host genome. | we have asked whether oncogenesis by the mouse mammary tumor virus (mmtv), a slowly oncogenic retrovirus, involves integration of viral dna within a certain region of the host genome. we first identified a c3h mouse mammary tumor bearing a single new mmtv provirus and cloned a 19 kilobase (kb) dna restriction fragment containing a junction of viral and host sequences. host sequences from this clone were used to retrieve 25 kb of the uninterrupted locus (termed mmtv int1) from a bacteriophage lib ... | 1982 | 6297757 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| long terminal repeats of endogenous mouse mammary tumour virus contain a long open reading frame which extends into adjacent sequences. | 1982 | 6276778 | |
| 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 |
| 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 |
| 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 |
| altered methylation of endogenous viral promoter sequences during mammary carcinogenesis. | 1982 | 6276763 | |
| 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 | |
| glucocorticoid regulation of protein processing and compartmentalization. | 1982 | 6292722 | |
| natural and induced immunity to mouse mammary tumors and the mammary tumor virus (mumtv). | 1982 | 6293110 | |
| cloned endogenous mouse mammary tumor virus dna is biologically active in transfected mouse cells and its expression is stimulated by glucocorticoid hormones. | 1982 | 6293178 | |
| development of a mouse mammary tumor virus-negative mouse strain: a new system for the study of mammary carcinogenesis. | all inbred strains of mice transmit one or more copies of mouse mammary tumor virus (mmtv) dna integrated as proviral sequences. this complicates efforts to define viral-induced mammary carcinogenesis. here we report the use of surgical nonlethal splenectomy in tissue typing mice and the development of an mmtv-negative mouse strain. the mmtv-negative strain allows study of the involvement of non-mmtv genes in mammary carcinogenesis. in addition, it can be used as a sterile background into which ... | 1982 | 6294336 |
| 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 | |
| sera from breast cancer patients contain an iga antibody to a breast cyst fluid component. | 1982 | 6286196 | |
| 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 |
| radioimmunoassay for major external glycoprotein of murine mammary tumor virus. | 1982 | 6286471 | |
| mammary tumor formation and hormonal control of mouse mammary tumor virus expression. | 1982 | 6303703 | |
| prostaglandin regulation of murine mammary tumor virus production: a basis for some of the glucocorticoid and prolactin actions on mammary tumor cell cultures. | hormonal regulation of mouse mammary tumor virus (mumtv) production has been studied in cell cultures derived from mammary carcinomas of gr mice. the purpose of this study was to define the role of prolactin in dexamethasone-induced mumtv production and to evaluate the mechanism(s) of action of these hormones. results of our investigations in vitro establish a central role for prostaglandins, in particular pgf2 alpha. prolactin treatment up to 1000 ng/ml increased the mumtv production only sligh ... | 1982 | 6296884 |
| mammary tumors in balb/cfc3h and balb/cfriii virgin female mice bearing hypophyseal isografts. | the behavior and morphology of mouse mammary tumors in high cancer strain mice are controlled by the causative murine mammary tumor viruses (mumtv). however, relationships also exist between mammary tumors and other factors such as host genotype, other etiologic agents (chemicals, x-rays), and hormones. among the latter, prolactin has been particularly studied. the aim of this investigation was to test whether the mammary tumor morphology controlled by c3h and riii mumtvs is in any way influence ... | 1982 | 6294936 |
| 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 |
| structural & immunological characteristics of murine mammary tumour virus of strain icrc from primary tumour cell cultures. | 1982 | 6307861 | |
| delimitation of a dna sequence which confers inducibility by glucocorticoid hormones. | a chimeric long terminal repeat-thymidine kinase (ltr-tk) gene has been used to define the sequence requirements for glucocorticoid induction of gene expression. the original ltr-tk gene contains an entire mouse mammary tumor virus (mmtv) ltr preceding the tk gene. this gene can be expressed in a hormone-responsive fashion upon transfection into l tk--cells to produce a chimeric ltr-tk mrna. stepwise deletion of nucleotide sequences 5' of the viral rna initiation site revealed that 202 nucleotid ... | 1982 | 6306020 |
| 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 |
| 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 |
| mammary tumor virus. investigations in mouse and man. | 1981 | 6305702 | |
| complementary dna copies of leukemia and sarcoma virus rna contain sequences of deoxycytidylate and deoxyguanylate. | single-stranded complementary dna (cdna) of the rna of gazdar murine sarcoma virus, gz-msv/mulv; moloney murine leukemia virus, m-mulv; mouse mammary tumor virus, mmtv; and simian sarcoma virus, ssv-1, were synthesized in endogenous reverse transcriptase reaction. gz-msv/mulv cdna was also synthesized in exogenous in vitro reverse transcriptase reactions. in the endogenous reaction, 30-35s, or 6.0- to 7.9-kilobase-length cdna transcripts were synthesized in high yield. in comparison, transcripts ... | 1981 | 6299564 |
| structure, stability, methylation, expression and glucocorticoid induction of endogenous and transfected proviral genes of mouse mammary tumor virus in mouse fibroblasts. | a sequence of mouse genomic dna containing an endogenous mouse mammary tumor virus (mmtv) provirus, which was isolated by molecular cloning in lambda vector phage, has been reintroduced into cultured mouse l cells, using the thymidine-kinase cotransfection technique. individual cell clones that acquired the transfected mmtv proviral dna have been isolated. the transfected dna remains stable in these cells and does not become methylated. it is transcribed into mmtv rna, and the transcription is s ... | 1981 | 6277735 |
| independence of h-2 and viral antigens on the cell surface and absence of h-2 antigens on murine leukemia virus and mouse mammary tumor virus particles. | by indirect immunoelectron microscopy we tested for the presence of h-2 antigens on murine mammary tumor virus (mmtv) and murine leukemia virus (mulv) particles. the association of h-2 antigens and viral antigens on the virus-infected cell surface was investigated with antibody-induced redistribution. mammary tumor cells and leukemia cell lines with different h-2 genotypes and carrying different mumtv or mulv were used. no h-2 antigens could be demonstrated on the envelope of mmtv and mulv parti ... | 1981 | 6277784 |
| [cross-reaction of human breast cancers with the envelope glycoprotein gp 52 of the mouse mamma tumorvirus (mmtv)]. | 1981 | 6289552 | |
| [electron microscopical observations of the junctional elements in virus-producing murine mammary tumors]. | 1981 | 6289553 | |
| genetic mapping of endogenous mouse mammary tumor viruses: locus characterization, segregation, and chromosomal distribution. | the restriction endonuclease ecori has been used to study the inheritance of strain difference in endogenous mouse mammary tumor virus dna sequences. this enzyme, which cleaves at only one site within the nondefective viral genome, generates dna fragments containing mouse mammary tumor virus sequences which vary in size according to the locations of ecori restriction sites in the flanking mouse sequences, thereby defining unique integration sites of the viral genome. recombinant inbred strains o ... | 1981 | 6275115 |
| expression of the murine mammary tumor virus in the milk of f1 hybrids of virus negative mouse strains. | 1981 | 6276182 | |
| use of an electroimmunodiffusion method on cellulose acetate films for the detection of antigenicity in human breast cancers that is related to the major core antigen of mouse mammary tumor virus (mumtv). | a highly sensitive electroimmunodiffusion method on cellulose acetate films, developed by abelev on the basis of isotachoelectrophoresis, was applied to search of mumtv-related antigenicity in tumor tissue and sera of breast cancer patients. in 2 out of 5 breast cancer extracts, protein fractions corresponding to a molecular weight of about 50,000 daltons were seen to exhibit antigenicity related to the major core antigen of mumtv (p27). this antigenicity could not be detected in the sera of the ... | 1981 | 6277267 |
| lack of induction of murine mammary tumor virus expression in cultured mammary glands treated with chemical carcinogens. | 1981 | 6270025 | |
| quantitative of murine mammary tumor virus-related rna in mammary tissues of low- and high-mammary-tumor-incidence mouse strains. | lactating mammary glands and hormonally induced mammary tumors of balb/c mice from three geographically separated breeding colonies were examined by molecular hybridization, using murine mammary tumor virus (mumtv) cdna representing the entire viral genome to determine the amount of mumtv-related rna expressed in these tissues. the rna extracted from these tissues by the classical sodium dodecyl sulfate-pronase, phenol-chloroform procedure (method 1) contained barely detectable levels of mumtv-r ... | 1981 | 6270387 |
| possible role of genetic cell variants in the viral induction of mouse mammary tumors. | out of three attempts to induce neoplasia in normal c57bl mammary epithelial cells with the mouse mammary tumor virus (mumtv) only one presented signs of tumorigenicity. immunofluorescence showed that virus synthesis took place in all three sublines but tumorigenicity as detected by cell aggregation viability (cav) and transplantation into syngeneic mice failed to occur in two of them. by comparison, cells from a balb/c spontaneous mammary tumor that do not express mumtv were 100% tumorigenic, w ... | 1981 | 6271665 |
| estimation of mouse mammary tumor virus gp52 abundance by protein a assay: a comparison of viral antigen expression on c3h and gr mammary tumor cells. | an adherent cell isotopic staphylococcal protein a test (ispat) was used to estimate the abundance of mouse mammary tumor virus (mmtv) gp52 cell surface antigen (csa)on mammary tumor cells. protein a assays were first utilized, not strictly as a means of antigen detection, but as a means to determine the kinetics of dexamethasone-mediated changes in gp52 cell surface expression. results indicated increases in gp52 csa within 4 h of dexamethasone treatment and maximal levels of antigen expression ... | 1981 | 6271704 |
| glucocorticoids regulate expression of dihydrofolate reductase cdna in mouse mammary tumour virus chimaeric plasmids. | fusions between the mouse mammary tumour virus long terminal repeat and a mouse dihydrofolate reductase cdna have been constructed in a sv40 vector. when these plasmids are transferred into recipient cells, the production of dihydrofolate reductase is regulated by glucocorticoid hormones. these results define a hormonally responsive region of the viral genome. | 1981 | 6272123 |
| activation of related transforming genes in mouse and human mammary carcinomas. | high molecular weight dnas of five tumors induced by mouse mammary tumor virus (mmtv), two mouse mammary tumors induced by a chemical carcinogen, and one human mammary tumor cell line (mcf-7) were assayed for the presence of transmissible activated transforming genes by transfection of nih 3t3 mouse cells. dnas of all five mmtv-induced tumors, one chemical carcinogen-induced tumor, and the human tumor cell line induced transformation with high efficiencies (approximately 0.2 transformant per mic ... | 1981 | 6272293 |
| the endogenous proviral mouse mammary tumor virus genes of the gr mouse are not identical and only one corresponds to the exogenous virus. | the endogenous proviral copies of mouse mammary tumor virus (mmtv) were selected from a gene library of gr mouse dna. we obtained five different lambda. mmtv recombinant clones. four of them correspond to the 3' eco ri fragments of the endogenous proviruses an one comprises an intact mmtv provirus with 2 to 3 kb of flanking mouse genomic dna. heteroduplex formation followed by s1 digestion under stringent conditions shows that there is nucleotide sequence heterology among the cloned endogenous p ... | 1981 | 6273791 |
| 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 |
| strain difference in the expression of mammary tumor virus antigen in the male genital organs of mice during aging. | mammary tumor virus (mtv) antigen expression was tested in the male genital organs (testis, epididymis, prostate, seminal vesicle and coagulating gland) of dd/tbr, kf and ddd strains (dd (german) mouse group), gr strain (swiss origin), shn and sln strains (different swiss origin), c3h and a strains (american origin), balb/c and c57bl strains (low mammary tumor strains), and ddf and shnf strains (mtv eliminated strains). microimmunodiffusion analysis showed that expression of mtv antigen is tissu ... | 1981 | 6274726 |
| covert infection of a mouse mammary tumor cell line with mycoplasma hyorhinis: cosedimentation with mouse mammary tumor virus in sucrose density gradients. | supernatant fluids from cultures of a mouse mammary tumor (mt) cell line were found to produce a specific cell detachment effect when inoculated into hela cells. the cell detachment factor (cdg) responsible for this effect was examined. repeated attempts to cultivate this cdf in bacteriologic, fungal, and mycoplasma media were unsuccessful. however, using the dna fluorochrome staining technique and specific immunofluorescent staining procedures, the cdf was identified positively as a noncultivab ... | 1981 | 6274789 |
| glucocorticoid regulation of the ha-musv p21 gene conferred by sequences from mouse mammary tumor virus. | molecular chimeras with the p21 transforming gene of harvey murine sarcoma virus linked to dna containing the long terminal repeat (ltr) or mouse mammary tumor virus (mmtv) have been constructed. transformants of nih 3t3 cells induced by transfection with mmtv ltr-p21 hybrid dna have been identified that express the normal p21 gene product. the levels of p21 rna and protein in these transformants are regulated by physiological concentrations of dexamethasone, a synthetic glucocorticoid hormone. ... | 1981 | 6277498 |
| organization of proviral dna and protein composition of hormonally stimulated c57bl/10 strain-associated mouse mammary tumor virus. | two continuous lines, bl-matu/a1 and bl-matu/s6, were established from c57bl/10 mammary adenocarcinomas induced by dmba-prolactin-estradiol treatment. under in vivo stimulation with dexamethasone, insulin, prolactin, and prostaglandin a1, the cells produce detectable amounts of b-type particles with biochemical properties similar to the gr-mumtv. analysis of restriction endonuclease-generated fragments of cellular dna revealed identical patterns in the integration sites and internal recognition ... | 1981 | 6280079 |
| enhanced immune reactivity to hepatoma 22a cells in mtv-infected compared with mtv-free c3h mice. | the transplantability and growth rate of mouse mammary and non-mammary tumours (sarcoma and hepatoma) were compared in mtv-free (mtv-) and mtv-infected (mtv+) c3h mice. it was demonstrated that sarcoma and hepatoma, in contrast to mammary tumours, grew better in mtv- mice. the difference between c3h sublines in the growth of hepatoma transplants was found to be determined by the stronger specific immune response and higher natural lymph node cell cytotoxicity in mtv+ mice. | 1981 | 6274791 |
| mammary tumor virus dna contains sequences required for its hormone-regulated transcription. | glucocorticoids regulate the rate of transcription of integrated murine mammary tumor virus (mtv) genes in most clones of mtv-infected rat hepatoma tissue culture (htc) cells. to determine whether hormonal regulation is mediated from flanking cellular sequences or rather from within the viral dna, we analyzed the relative rates of transcription of mtv and adjacent htc sequences in two lines of infected htc cells, j2.15 and j2.17, each of which contains a single insertion of mtv dna. in addition, ... | 1981 | 6277499 |
| 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 |
| enzymoimmunoassay of the main core protein (p28) of mouse mammary tumour virus (mmtv). | 1981 | 6266832 | |
| is there any diagnostic relevance of human antibodies which react with mouse mammary tumor virus (mumtv)? | applying an indirect immunofluorescence assay with prolonged serum incubation on frozen-cut mouse mammary tumor slices, antibodies are detectable in human sera which react with viral inclusion bodies consisting of intracytoplasmic a particles (iap). these iap are known to represent intracellular entities of the mouse mammary tumor virus (mumtv), mainly related to mumtv core constituents. in 1,449 women studied, the antibody incidence is partially correlated with proliferating changes of the mamm ... | 1981 | 6274270 |
| earlier appearance of murine mammary tumor virus-associated antigens in duct-alveolus nodules induced by transplantation of fetal salivary mesenchyme into c3h mouse mammary glands. | mammary epithelium of adult c3h mice in contact with fetal salivary mesenchyme took morphogenetically a salivary gland-like pattern of growth and developed a hyperplastic nodular mass at the site of transplantation. when murine mammary tumor virus-bearing c3h mice were treated in this way, early development and high incidence of mammary cancer were observed from these nodules compared to unstimulated mammary glands of the same host. since tumor development, the viral antigens in these hyperplast ... | 1981 | 6281120 |
| accelerated mammary cancer development by fetal salivary mesenchyma isografted to adult mouse mammary epithelium. | transplantation of fetal salivary mesenchyma into adult mammary glands resulted in atypical outgrowths from the mammary duct system. these duct-alveolus nodules (dan) were distinguishable from hyperplastic alveolar nodules (han) that arose from normal mammary duct systems in mice infected with murine mammary tumor virus (mumtv). dan displayed a type of ductal branching characteristic of salivary gland rather than of mammary gland, reflecting a tissue-specific perturbation of epithelium-mesenchym ... | 1981 | 6262561 |
| [possible participation of endogenous mmtv virus in chemical carcinogenesis of mouse mammary glands]. | a study was made of the effect of immunization with formalinized mmtv on mammary tumor incidence in balb/c mice exposed to dimethylbenzanthracene. in mice immunized with mmtv, the incidence of mammary tumours was significantly lower and the latent period longer as compared with the control group immunized with mulv. the indirect fixed immunofluorescence technique has shown that tumour cells in both groups express gp52 and p27 antigens. the possible involvement of endogenous mmtv into chemical ca ... | 1981 | 6271307 |
| in vitro synthesis of polypeptides encoded by the long terminal repeat region of mouse mammary tumour virus dna. | 1981 | 6262660 | |
| sandwich enzyme immunoassay of mouse mammary tumor virus. | 1981 | 6263672 | |
| viral epitopes and monoclonal antibodies: isolation of blocking antibodies that inhibit virus neutralization. | the inability of pathogenic animal viruses to be completely neutralized by antibodies can lead to chronic viral infections in which infectious virus persists even in the presence of excess neutralizing antibody. a mechanism that results in this nonneutralized fraction of virus was defined by the topographical relationships of viral epitopes identified with monoclonal antibodies wherein monoclonal antibodies bind to virus and sterically block the binding of neutralizing antibodies. | 1981 | 6264601 |
| partial expression of endogenous mouse mammary tumor virus in mammary tumors induced in balb/c mice by chemical, hormonal, and physical agents. | the possible interaction of environmental factors with the endogenous mouse mammary tumor virus (mmtv) genome in the development of mammary tumors in the low-tumor-incidence balb/c mouse strain was examined. tumors were induced in virgin female animals by treatment with chemical carcinogen 7,12- dimethylbenz[alpha]anthracene or urethan, with or without prolonged hormonal stimulation, or by x-irradiation. concomitant hormonal stimulation resulted in increased tumor incidences compared with those ... | 1981 | 6264129 |
| absence of antigens related to murine mammary tumour virus polypeptides in rat mammary tumours. | 1981 | 6273175 | |
| age- and sex-related differences in antibody formation and blastogenic responsiveness of splenocytes from riii mice developing virus-induced mammary adenocarcinoma. | inbred riii mice, known to be infected neonatally with murine mammary tumor virus so that females develop mammary adenocarcinoma by 12-15 months of age, were examined with regard to antisheep red blood cell antibody responses at the cellular level. female mice, 3-11 months old, compared to male mice of the same ages had consistent and significant depression of the antibody response of their splenocytes. furthermore, female mice with adenocarcinoma showed an even greater depression of the antibod ... | 1981 | 6273637 |
| regulatory and coding potential of the mouse mammary tumor virus long terminal redundancy. | molecular clones containing the 3' half of newly integrated mouse mammary tumor virus (mmtv) dna with adjacent mouse cellular sequences were characterized. in addition, we cloned the long terminal redundancy joint from the unintegrated circular form of mmtv dna. the entire nucleotide sequence of the integrated and part of the unintegrated terminal redundancy was determined; this allowed us to delineate the boundaries of the mmtv long terminal redundancy, which comprises 1,327 base pairs. the pos ... | 1981 | 6260976 |
| purified glucocorticoid receptors bind selectively in vitro to a cloned dna fragment whose transcription is regulated by glucocorticoids in vivo. | activated glucocorticoid receptor protein, purified to 40-60% homogeneity from rat liver extracts, binds selectively in vitro to a cloned fragment of murine mammary tumor virus (mtv) dna. the dna fragment tested contains about half of the sequences present in intact mtv dna, and its rate of transcription, like that of the intact viral element, is strongly stimulated by glucocorticoids when it is introduced into the genome of a receptor-containing cell. in contrast, the receptor fails to bind sel ... | 1981 | 6273877 |
| restriction endonuclease studies of hyperplastic outgrowth lines from balb/cfc3h mouse hyperplastic mammary nodules. | the dna's isolated from five mouse hyperplastic mammary gland outgrowth lines from balb/cfc3h mice were digested with the restriction endonucleases psti, bamhi, or ecori; electrophoresed; and analyzed by southern blotting and autoradiography. proviral dna sequences from the acquired c3h mouse mammary tumor virus were detected in the dna of all five lines, indicating that they were infected. the dna of the five hyperplastic lines contained more ecori and bamhi mouse mammary tumor virus proviral d ... | 1981 | 6265073 |
| antibodies reactive with murine mammary tumor virus in sera of patients with breast cancer: geographic and family studies. | sera of patients with breast cancer, of healthy women from the united states, east india, east africa, and china, and of healthy women of american and parsi families in which breast cancer occurred in several family members were assayed for levels of antibody reactive with the murine mammary tumor virus (mumtv) by an enzyme-linked immunosorbent assay. increased levels of antibody to mumtv (absorbance greater than or equal to 0.4) were found in sera of 18.6% of american patients with breast cance ... | 1981 | 6264479 |
| chromatographic evidence that the aaa-coding isoacceptor of lysine trna primes dna synthesis in murine mammary tumor virus. | 1981 | 6266151 | |
| dexamethasone induction of the intracellular rnas of mouse mammary tumor virus. | we have studied the kinetics of dexamethasone induction of mouse mammary tumor virus (mmtv) rnas and proteins in virus-infected rat xc cells and gr mouse mammary tumor cells. a detectable increase in viral rna in infected xc cells was present within 10 min after hormone addition, and half-maximal induction was achieved in less than 2 h. the increase in viral rna concentration was apparent first in nuclear rna and later in the cytoplasm. within the first 15 min of induction, only genome-sized rna ... | 1981 | 6275112 |