Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| naturally occurring humoral immunity to murine mammary tumor virus (mumtv) and mumtv gp52 in mice with low mammary tumor incidence. | 1978 | 214408 | |
| modulation of mouse mammary tumor virus production in the mjy-alpha cell line. | implantation of the mouse mammary tumor virus (mmtv)-producing mammary tumor cell line mjy-alpha into isogeneic mice elicited both humoral and t-cell responses against mmtv virion antigens. the carcinosarcomas which developed from the implanted cells showed a significant decrease in mmtv synthesis, compared with cells remaining in culture, which was detectable as early as 7 days after implantation and for five transplant generations. electron microscopic examination of thin sections of the tumor ... | 1978 | 214582 |
| isolation of host-range variants of mouse mammary tumor viruses that efficiently infect cells in vitro. | host-range variants of mouse mammary tumor virus (mmtv) have been isolated that have the ability to productively infect cells in vitro with high efficiency (at multiplicities of infection </=1) and with extremely short latent periods to the production of de novo virus (as short as 4 days after infection). these variants of the highly oncogenic mmtv of riii, c3h, and gr mice were obtained by serial virus passage in feline cells. the resultant variant stocks react in group-specific radioimmunoassa ... | 1978 | 214796 |
| translation of mouse mammary tumor virus rna: precursor polypeptides are phosphorylated during processing. | 1978 | 214954 | |
| mammary tumor virus expression in the gr mouse strain: efficiency of chromosomal and extrachromosomal transmission. | 1978 | 215482 | |
| detection of mouse mammary tumor virus rna in balb/c tumor cell lines of nonviral etiologies. | a complementary dna (cdna) probe to mouse mammary tumor virus (mmtv) rna was synthesized using calf thymus dna oligonucleotides as a random primer. this probe was then used to study the expression of mmtv rna in cell lines from balb/c tumors induced in vivo either spontaneously or in response to viral, chemical, or hormonal stimuli. the cdna had a length of approximately 400 to 500 nucleotides and specifically hybridized to mmtv rna and balb/c lactating mammary gland rna, but not to moloney leuk ... | 1978 | 215778 |
| h-2 restriction and non-restriction of t-cell-mediated cytotoxicity against mouse mammary tumour targets. | 1978 | 216918 | |
| structural components of mouse mammary tumor virus. iii. composition and tryptic peptides of virion polypeptides. | 1978 | 217150 | |
| phosphoproteins of the murine mammary tumor virus. | 1978 | 217155 | |
| humoral antibodies to mouse mammary tumor virus in sera from breast cancer patients. | 1978 | 220186 | |
| oncogenicity of murine mammary tumor virus produced in tissue culture: brief communication. | murine mammary tumor virus (mumtv), produced from a glucocorticoid-stimulated c3h mouse mammary adenocarcinoma cell line, was free of murine leukemia virus and oncogenic for weanling balb/c mice. adenocarcinomas were induced by mumtv as early as 136 days post inoculation and with as low as 5 x 10(3) virus particles/mouse. tumor incidence did not correlate directly with virus dose; rather, it was low at higher mumtv concentrations (1.2 x 10(8) particles/mouse), reached and optimum at 1.3 x 10(5) ... | 1978 | 202721 |
| synthesis and processing of precursor polypeptides to murine mammary tumor virus structural proteins. | biosynthesis of murine mammary tumor virus (mumtv) proteins was studied in the chronically mumtv-infected epithelial cell line mumt-73 by using monospecific antisera to the major mumtv core protein p27 and the major envelope glycoprotein gp47. in pulse-labeling experiments using [35s]methionine, monospecific antisera to p27 precipitated a 75,000-molecular-weight protein as the major intracellular component. analysis of the same cellular extracts with monospecific antisera to gp47 revealed that t ... | 1978 | 202748 |
| cellular immunity to autologous breast cancer and riii-murine mammary tumor virus preparations. | 1978 | 207421 | |
| detection of inapparent nodule-transformed cells in the mammary gland tissues of virgin female balb/cfc3h mice. | inapparent nodule-transformed cells were recovered from morphologically normal mammary tissue from virgin female balb/cfc3h/crgl (mouse mammary tumor-positive) mice before the appearance of hyperplastic alveolar nodules (han) or tumors, by means of the cell dissociation technique. mammary tissues were dissociated by means of collagenase (0.1%), hyaluronidase (0.1%), and pronase (1.25%). aliquots of 10(5) viable cells in 0.01 ml medium were injected into the gland-free mammary fat pads of 3-week- ... | 1978 | 207423 |
| hormonal control of mrna synthesis studied by nucleic acid hybridization. | the regulation of protein synthesis by steroids is thought to be due to hormonal effects primarily on mrna concentration. experimental evidence to support this conclusion has come largely from the use of dna probes complementary (cdna) to mrna molecules or by translation of the mrna in vitro. in this review the experimental procedures involved and the application to hormone action of cdna hybridization will be reviewed. (1) mrna concentrations can be assayed in tissue rna samples by hybridizatio ... | 1978 | 207603 |
| induction of mammary tumors in c57bl/haag female mice by a low oncogenic mammary tumor virus. | mammary tumor virus (mumtv)-negative mouse substrain c57bl/haag foster-nursed by strain dd becomes a line with a moderately high incidence of mammary tumors occurring in the females at a late age. electron microscopy revealed b particles in the tumors, providing additional evidence for the propagation and transmission of dd-mumtv in c57bl/haagfdd. since both albino strains dd and riii originated in europe, develop pregnancy-dependent mammary tumors, carry black and agouti genes (cc, bb, aa), and ... | 1978 | 207649 |
| mouse mammary tumor virus genes: regulation of expression by glucocorticoids and structural analysis with restriction endonucleases. | the production of mouse mammary tumor virus (mtv) is stimulated by treatment of mammary carcinoma cells with glucocorticoid hormones (e.g., dexamethasone). the reaction appears to be a primary and receptor-mediated phenomenon in which the rate of synthesis of mtv rna is selectively increased; the maximally induced rate is reached within 15 min after addition of the hormone. production of mtv rna is also stimulated by dexamethasone in some but not all clonal isolates of nonmurine cells infected b ... | 1978 | 207882 |
| structural components of mouse mammary tumor virus. ii. isolation and purification of virion polypeptides. | mouse mammary tumor virus (mmtv) glycoproteins and nonglycosylated polypeptides were purified by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. primary amino groups were labeled with fluorescamine to enable visualization of mmtv polypeptides in the gels. protein bands were sliced from the gels and eluted with 90 to 95% recovery. eight mmtv polypeptides, including three of the major viral components as well as five minor proteins, were routinely obtained. double diffusion ... | 1978 | 207897 |
| the relative hydrophobicity of oncornaviral structural proteins. | 1978 | 208256 | |
| coexistence of the mouse mammary tumor virus (mmtv) major glycoprotein and natural antibodies to mmtv in sera of mammary tumor-bearing mice. | 1978 | 208275 | |
| changes in mumtv dna and rna levels in balb/c mammary epithelial cells during malignant transformation by exogenous mutv and by hormones. | 1978 | 208280 | |
| cellular immunity to mammary tumor virus in normal and tumor-bearing c3h/hen mice. | 1978 | 208765 | |
| mammary tumor virus oncogenesis and tumor immunogenicity in three sublines of the c3h mouse. | mammary tumorigenesis and mammary tumor transplantation immunogenicity have been studied and compared in three sublines of the c3h strain: in standard mammary tumor virus (mtv-s)-infected c3h/he mice; in mtv-s-infected c3h/ki mice; and in mtv-s-free c3hf/he mice. the age at the appearance of the first tumor, the growth rate of the tumors in their first transplant generation, and the immunogenicity of each tumor in syngeneic female recipients have been determined for the first tumor to appear in ... | 1978 | 208767 |
| observations on the question of horizontal transmission of mouse mammary tumor virus. | antigen and tumor incidences in balb/c and c57bl mice after living as weanlings for 5 weeks in cages with mouse mammary tumor virus-infected females were compared with control balb/c and c57bl mice living in the same laboratory. all mice were bred continuously, and third-lactation milks were tested for mouse mammary tumor virus antigen by ouchterlony microimmunodiffusion test. mammary tumor incidences in the cagemates were not significantly different from those in the controls, although the anti ... | 1978 | 208768 |
| genetic transmission of mammary tumour virus in the dbaf mouse strain. | mtv antigens were demonstrable by radioimmunoassay in milk samples from individual dbaf mice, and in samples from (male balb/c x female dbaf) f1 mice. although some samples collected during the first lactation periods of these mice were virus-negative, all samples of later lactation periods were virus-positive. from 75 mice of the [ male balb/c x female (male balb/c x female dbaf)]bc i population, milk samples were collected during one or more lactation periods and tested for the presence of vir ... | 1978 | 208984 |
| type b and type c rna tumor virus replication in single cells. electron microscopy with tannic acid. | simultaneous replication of murine mammary tumor virus (type b) and murine leukemia virus (type c) was demonstrated electron microscopically along continuous stretches of the plasma membrane of single cells in cultures ofthe mm5mt/c1 cell line. types b and c virus buds were discriminated in thin sections with the aid of a tannic acid fixative that revealed the type b surface spikes as a homogeneous band of intermediate density and constant width on the surfaces of some buds (type b), whereas oth ... | 1978 | 209205 |
| estrogen binding in mammary tissue of c3h mice with or without the mouse mammary tumor virus. | substrains of c3h mice, with and without the milk-transmitted form of the mouse mammary tumor virus (mmtv)1, were compared to determine if the presence of mmtv altered estrogen action. uterine weight response to oral diethylstilbestrol was the same for both substrains, (mmtv+ and mmtv-). the concentration of high-affinity estrogen binding sites ("receptors") in lactating mammary tissue did not differ significantly for mmtv+ versus mmtv- mice; the affinity of the estradiol-receptor interaction ap ... | 1978 | 209378 |
| mapping of linear and circular forms of mouse mammary tumor virus dna with restriction endonucleases: evidence for a large specific deletion occurring at high frequency during circularization. | rat hepatoma cells infected with mouse mammary tumor virus contain multiple forms of unintegrated viral dna when grown in the presence of glucocorticoids. using the dna transfer procedure of southern, we have prepared restriction endonuclease fragment maps of these forms of viral dna. the maps indicate that: (i) the major species of viral dna is a linear molecule of 5.9 x 10(6) mr located in the cytoplasm; (ii) the nuclei contain covalently closed circular viral dna of two distinct sizes (5.1 x ... | 1978 | 209450 |
| identification of the mtv-2 gene responsible for the early appearance of mammary tumors in the gr mouse by nucleic acid hybridization. | in the mouse strain gr, the mtv-2 gene controls the expression of large amounts of mammary tumor virus (mtv) antigens in the milk at first lactation. it also controls the early appearance of mammary tumors. we have investigated the number of mtv proviral sequences associated with this mtv-2 gene by nucleic acid hybridization between mtv [(3)h]cdna and dna from gr, b10, and gr-mtv-2(-) mice. b10 and gr-mtv-2(-) mice lack mtv-2 gene expression. the molecular hybridizations revealed that the dna of ... | 1978 | 209461 |
| suppressed development of mammary tumorigenesis in r iii mice treated neonatally with bcg. | 1978 | 209474 | |
| bioactivity of male (sperm transmitted) mouse mammary tumor virus as influenced by donor, recipient and age at treatment. | the sperm collected from mammary tumor virus (mtv)-carrying mice (c3h, balb/cfc3h, balb/cfriii and riii) was separately tested for mammary tumor-inducing activity in (balb/c x c3hf)f1, (balb/c x riiif) f1, and balb/c female recipients by i.p., injection of 0.1 ml of the sperm at 1-2 weeks or at 3 months of age. a total of 551 recipents was observed, including control mice. the results may be summarized as follow: 1) mammary tumor incidence in experiments with or without histocompatibility betwee ... | 1978 | 209593 |
| suppressed murine mammary tumor virus (mumtv) expression in riii female mice treated neonatally with goat antiserum to mumtv. | passive immunization of newborn inbred riii (r3) mice with the globulin fraction of goat antiserum to murine mammary tumor virus (mumtv) successfully suppressed mumtv expression in the milk of some of the treated mice throughout nine successive lactations. no mammary tumors developed in the mumtv-suppressed mice during the first 9 months, whereas all untreated r3 female breeders expressed mumtv in the milk of the third lactation, and all developed tumors before 9 months of age (mode and median: ... | 1978 | 210290 |
| prevalence of murine mammary tumor virus antibody and antigens in normal and tumor-bearing feral mice. | approximately 20% of normal male and female feral mice (mus musculus) from areas with populations having either high [lake casitas (lc) and la puente] or low (bouquet canyon) spontaneous lymphoma incidence expressed murine mammary tumor virus (mumtv) gp52 in specific tissues. sera from a low percentage (6%) of mice from the same trapping areas contained precipitating antibody specific for mumtv. although moderate to high levels of mumtv gp52 were expressed in mammary tumor tissues of 3 of 7 lc m ... | 1978 | 210292 |
| heterogeneity of tumor cells from a single mouse mammary tumor. | by the use of a variety of cell culture and separation methods, four cell lines were isolated from a single autochthonous balb/cfc3h mammary tumor. these lines differ markedly from each other in culture morphology, various in vitro growth properties, expression of murine mammary tumor virus antigen, and karyotype, yet all four lines are tumorigenic in normal, syngeneic hosts, yielding tumors of generally similar histology, although distinct from the original neoplasm. three of the four lines hav ... | 1978 | 210930 |
| mammary tumour virus and casein gene transcription during mouse mammary development. | 1978 | 211437 | |
| mouse mammary tumor virus and murine leukemia virus cell surface antigens on virus producer and nonproducer mammary epithelial tumor cells. | 1978 | 211719 | |
| comparative susceptibilities of hybrid mice to four mammary tumor viruses from two mouse strains. | 1978 | 212182 | |
| hormonal induction of mammary tumor viruses and its implications for carcinogenesis. | the purpose of this study was to evaluate the possibility that hormones and mouse mammary tumor virus (mumtv) are cocarcinogenic for mammary epithelium. results of our investigations in vivo and in vitro suggest: (a) hormones promote mammary carcinogenesis in balb/c females whether mumtv is germinally (balb/c) or horizontally (balb/cfc3h) transmitted; the rate of carcinogenesis in balb/cfc3h females is substantially faster than it is in balb/c, but the final mammary carcinoma incidence is approx ... | 1978 | 212187 |
| hydrophobic interaction of retroviral dna polymerases with alkyl-agarose matrices. | 1978 | 203279 | |
| in situ embedding method of cells grown in beem capsules for immunoelectron microscopic studies of oncornaviruses. | a technique of in situ embedding of cells grown in beem capsules has been devised for immunoelectron microscopic studies of oncornaviruses. as compared to other immunoelectron microscopic procedures, this technique is less time and reagent-consuming. the quality and specificity of this method were tested on well-characterized mouse mammary tumor virus (type b virus) and murine sarcoma virus (type c virus particles). this method gave good results in labeling of the virus particles with ferritin o ... | 1978 | 203626 |
| suppressor cells in mice with murine mammary tumor virus-induced mammary tumors. i. inhibition of mitogen-induced lymphocyte stimulation. | suppressor cell activity was present in the glass-adherent fraction of spleen cells from c3h mice bearing murine mammary tumor virus-induced mammary tumors. these cells effectively suppressed the blastogenic response of syngeneic normal lymphocytes to concanavalin a (con a). suppression by the spleen cells from mammary tumor-bearing mice was not dependent on dna synthesis. removal of the suppressor cells from spleen cell suspensions of tumor-bearing mice was not dependent on dna synthesis. remov ... | 1978 | 203703 |
| in vitro transcription of mouse mammary tumor virus rna into dna. | the in vitro transcription of the b-type mouse mammary tumor virus rna into dna is similar to that obtained with certain c-type viruses: synthesis can be initiated on an rna primer molecule approximately the size of a trna, and a unique linkage (ra-dc) exists between this primer and the dna product. | 1978 | 203724 |
| interaction between viral and genetic factors in murine mammary cancer. | 1978 | 204164 | |
| characterisation of mammary tumour virus of strain icrc mouse. | 1978 | 204490 | |
| in vitro studies on splenocyte cytotoxicity against syngeneic mammary carcinomas of mice. 1. reactivity of splenocytes from mice bearing mammary tumors against the corresponding and against other neoplasms. | 1978 | 204609 | |
| alteration of sodium transport in mouse mammary epithelium associated with neoplastic transformation. | using electrophysiological techniques we have examined the apical membrane ionic permeabilities of primary cell cultures of the mouse mammary gland in the midpregnant, preneoplastic, and neoplastic states. membrane na+ permeability changed with tumorigenesis, whereas k+ and cl- permeabilities were unaltered. with tracer flux techniques the unidirectional efflux rate constant of 22na was found to be greater in tumor cells than it is in normal cells. this increase in 22na efflux was eliminated by ... | 1978 | 205364 |
| immunization of mice against murine mammary tumor virus infection and mammary tumor development. | formalin-inactivated whole murine mammary tumor virus (mumtv), vumtv membranes, the acid-soluble component of mumtv, and purified mumtv glycoprotein with a molecular weight of 55,000 (gp55; also designated as gp52) were used as vaccines in an attempt to identify the mumtv antigen(s) that can protect mice from exogenous mumtv infection and subsequent tumor development. formalin-inactivated whole mumtv, mumtv membranes, and purified mumtv gp55 were effective immunogens, whereas the acid-soluble co ... | 1978 | 205366 |
| the use of molecular hybridization to track the mode of transmission and distribution of murine mammary tumor viruses: a model for etiologic studies of human breast cancer. | 1978 | 205905 | |
| study of the glycolipid composition of the milk fat-globule membrane and the mouse mammary tumour virus prepared from the milk of infected swiss mice [proceedings]. | 1978 | 84579 | |
| demonstration of components of serum-free culture medium effecting maximum in vitro expression of mouse mammary tumor virus. | by using a chemically defined serum-free (sf) medium for propagation of mm5mtc1 mouse adenocarcinoma cell cultures and clonal derivatives, medium components including hormones, glucose and individual amino acids were evaluated as to modulation of mouse mammary tumor virus (mmtv) porduction. insulin, hydrocortisone and dexamethasone each increased mmtv production on a per cell basis over constitutive expression that occurs in sf medium devoid of hormones. maximum production occurred when all thre ... | 1978 | 78889 |
| early detection of tumor-specific antibodies to mammary carcinoma. | balb/cfc3h female mice which develop mammary tumor virus (mtv)-induced mammary tumors possess not only serun antibodies directed against virus-associated antigens which are expressed on mammary tumor cells but also antibodies directed against antigenic specificities which are unique to each tumor. the possible range of unique specificities is considerable; a survey of serum samples from 18 tumor-bearing females revealed only two which reacted with a tumor-unique specificity of another isologous ... | 1978 | 78910 |
| polyproteins related to the major core protein of mouse mammary tumor virus. | the mouse mammary tumor virus (mumtv) contains several low-molecular-weight proteins which, together with the genomic rna, constitute the core structure of the virion. the most abundant protein in the core is the 27,000-dalton protein (p27), and, by analogy to the type c viruses, this protein probably forms the core shell. in mouse mammary tumor cell lines (gr and mm5mt) producing mumtv the major p57 antigenic specificity resides in a large protein, which migrates in polyacrylamide gels as a dou ... | 1978 | 78987 |
| accelerated growth of mammary tumor cells in normal and athymic mice after treatment in vitro with dexamethasone. | the tumorigenicity of dexamethasone-treated tissue-cultured mammary tumor cells was compared to that of untreated mammary tumor cells. the dexamethasone-induced cells progressed faster in normal syngeneic animals than did untreated mammary tumor cells. the fact that the growth rate differential was also observed in athymic mice suggests that t-lymphocyte-mediated immunity was not a factor in the accelerated progression in vivo of the tumor cells that had been cultured in the presence of dexamet ... | 1978 | 80260 |
| specificity of the simultaneous cell-mediated immune reactivity to riii murine mammary tumor virus glycoprotein 55 and human breast cancer tissues. | 1978 | 80264 | |
| immunohistochemical detection of a cross-reacting virus antigen in mouse mammary tumors and human breast carcinomas. | an indirect immunoperoxidase method was first used to localize mouse mammary tumor virus (mmtv) antigens in paraffin sections of mammary tumors of paris riii and cd8f1 mice. by using the same method, an antigen with cross-reactivity to a group-specific antigen (gp52, a 52,000 dalton glycoprotein) of mmtv was detected in paraffin sections of human breast carcinomas. the specificity of this reaction with antibody against mmtv was examined by absorption of the igg with: a) purified gp52; b) several ... | 1978 | 80418 |
| immunologic methods for the identification of cell types. ii. expression of normal mouse mammary epithelial cell antigens in mammary neoplasia. | mouse mammary epithelial (mme) cell antigens were cell type-specific and were retained, to a large extent, by mme cells after neoplastic transformation. these mme cell antigens were expressed in mammary tumors of balb/c, c3h, grs/a, riii, and is/bi mice tested and were not expressed in tumors whose normal counterpart was other than mammary tissue. they were not dependent on cell culture conditions or on the presence of murine mammary tumor virus; therefore, they can be used in an ubiquitous cell ... | 1978 | 80454 |
| [detection of common antigenic determinants in the envelopes of mammalian type d (mason--pfizer) and type c virions by using the virion precipitation reaction]. | immune sera to mason-pfizer virus (m-pmv) are capable of precipitating type c viruses of mice (nih-mulv, g-mulv, and to a lower degree r-mulv), cats (felv, rd-114), and monkeys (ssv-1, galv, bev). the immune sera to rd-114, bev, ssv-1 and galv viruses can precipitate m-pmv virions. the adsorption analysis suggests that cross-reactions between m-pmv, rd-114, nih-mulv, and g-mulv viruses depend on common virus-specific antigenic determinants in the envelopes of the virions. the relationship betwe ... | 1978 | 80888 |
| effect of 5'-deoxy-5'-s-isobutyl-adenosine (siba) on mouse mammary tumour cells and on the expression of mouse mammary tumour virus. | 1978 | 81053 | |
| detection of cell-mediated immune reactivity of breast cancer patients by the leukocyte adherence inhibition response to mcf-7 extracts. | 1978 | 81103 | |
| immunological characterization of the low-molecular-weight dna binding protein of mouse mammary tumor virus. | p14, a low-molecular-weight mmtv protein previously identified as having dna-binding properties and encoded by the gag region of the mmtv genome, was purified by affinity chromatography on dna-sepharose. immunological characterization of the purified protein showed that mmtv p14 shares no cross-reactivity with gp52, gp36 and p10, antigens associated with the mmtv envelope, nor with p27 antigen found in the virion core. purified mmtv p14 did show cross-reactivity with purified intracytoplasmic a ... | 1978 | 81189 |
| evidence for a precursor-product relationship between intracytoplasmic a particles and mouse mammary tumour virus cores. | this report presents evidence which supports a relationship between intracytoplasmic a particles (cap) and mouse mammary tumour virus (mmtv). three mmtv-specific antigenic determinants in cap (mmtv p27, p14 and p10) uere detected by immunodiffusion. no structural proteins of comparable mol. wt. were found in cap; however, exposure of cap to trypsin resulted in the cleavage of the cap structural proteins to mmtv-like polypeptides. this process was accompanied by the preservation of mmtv-specific ... | 1978 | 81268 |
| presence of a mouse mammary tumor virus-related antigen in human breast carcinoma cells and its absence from normal mammary epithelial cells. | antigen(s) related to the major external glycoprotein (gp52) of mouse mammary tumor virus was detected in the human breast cancer cell line mcf-7. no such antigenic determinants were detectable in normal human mammary epithelial cells. | 1978 | 81881 |
| characterization of a new virus from mus cervicolor immunologically related to the mouse mammary tumor virus. | a virus, similar to the murine mammary tumor viruses (mumtv) of the laboratory mouse mus musculus, was identified in the milk of m. cervicolor popaeus mice. the virus was morphologically indistinguishable from the type-b mumtv and was thus termed mc-mtv. radioimmunoassays for the 52,000-dalton major envelope glycoprotein and the 28,000-dalton major internal protein of mumtv demonstrated that mc-mtv shared some antigenic determinants with both of these mumtv proteins. this reactivity was clearly ... | 1978 | 82634 |
| differential expression of poly(a)-adjacent sequences of mammary tumor virus rna in murine mammary cells. | two dna probes representative of either the entire mouse mammary tumor virus (mmtv) genome or the poly(a)-adjacent sequences at the 3' end of mmtv rna were synthesized with calf thymus dna or oligo(dt) primers, respectively. these probes were used to study the expression of endogenous mmtv sequences in several balb/c mammary tumor cell lines, in normal lactating balb/c tissue, and in a cloned c3h tumor cell line. both probes were characterized with respect to their rates of hybridization with te ... | 1978 | 83648 |
| the biosynthesis of oncovirus proteins. | the patterns of oncovirus protein biosynthesis are essentially similar for avian and mammalian viruses. in each case the four major internal structural proteins are synthesized as a precursor polypeptide of about 75 000 daltons, the product of the gag gene. translation occurs on genome-sized mrna. this polyprotein is cleaved in a series of steps to give the mature proteins. the mechanism and localization of cleavage have not yet been clarified. viral reverse transcriptase, the product of the pol ... | 1978 | 77678 |
| radioimmunoassays that demonstrate type-specific and group-specific antigenic reactivities for the major internal structural protein of murine mammary tumor viruses. | the 28,000-dalton (p28) major structural polypeptide of the mouse mammary tumor virus (mmtv) was isolated and used to develop a highly sensitive and specific radioimmunoassay. under conditions of limiting antibody in competitive binding assays, as little as 50 pg of purified p28, as well as disrupted mmtv virions and mammary tumor extracts, competed specifically with 125i-labeled mmtv p28. the p28 polypeptide was further shown to contain both group-specific and type-specific antigenic determinan ... | 1978 | 77723 |
| specificity and age of appearance of natural immunity to mtv antigens. | 1978 | 78494 | |
| radioimmunologic characterization of rd-114 reverse transcriptase: evolutionary relatedness of mammalian type c viral pol gene products. | 1978 | 78564 | |
| mammary tumor virus dna: a glucocorticoid-responsive transposable element. | 1978 | 28200 | |
| retroviral "terminal deoxynucleotidyl transferase" activity is reverse transcription. | 1978 | 74894 | |
| characterization of rna-directed dna polymerase in the milk of strain icrc mice. | 1978 | 89078 | |
| mammary tumor viruses. | 1979 | 89801 | |
| purification and properties of rna-dependent dna polymerase from cytoplasmic a-type particles of murine mammary tumor virus. | 1. the rna-dependent dna polymerase associated with cytoplasmic a-type particles of murine mammary tumor virus was isolated to near homogeneity by a procedure which includes dissociation of proteins from rna by centrifugation in a step gradient of cesium chloride, followed by an affinity chromatography on poly(rc)-agarose column. two species of dna polymerase were separated by the chromatography: enzyme i in 0.55 m nacl and enzyme ii in 0.80 m nacl eluate, respectively. 2. the purified dna polym ... | 1979 | 89959 |
| immunological characterization of mouse mammary tumor virus p10 and its presence in mammary tumors and sera of tumor-bearing mice. | mouse mammary tumor virus (mmtv) p10 and gp52 were purified and used as radiolabeled antigens in sensitive radioimmunoassays. these radioimmunoassays were specific for mmtv proteins since detergent-disrupted mmtv from c3h/hen, riii, and gr/n mice gave complete competition, whereas c3h/henf liver extracts and other lysed retroviruses did not. both gp52 and p10 are coded by the viral genome, since mmtv grown in a heterologous cell line (feline kidney cells) competed in these assays. sera from mamm ... | 1979 | 90156 |
| radioimmunoassays for the 36,000-dalton glycoprotein of murine mammary tumor viruses demonstrate type, group, and interspecies determinants. | mouse mammary tumor viruses (mmtvs) contain distinct membrane glycoproteins of 52,000 daltons (gp52) and 36,000 daltons (gp36). we report here the development of new radioimmunoassays for gp36, using gp36 purified by hydrophobic chromatography and gel filtration. these assays demonstrate that gp36 has both type-specific and group-specific antigenic determinants. the virus-coded nature of these determinants was shown by utilizing different mmtvs grown in the same feline cell line. interspecies d ... | 1979 | 90170 |
| simultaneous purification of murine mammary tumor virus structural proteins: analysis of antigenic reactivities of native gp34 by radioimmunocompetition assays. | all the structural proteins (gp47, gp34, p27, p23, p16, and p12) of the murine mammary tumor virus (mumtv) were simultaneously purified utilizing alkylagarose chromatography as the initial fractionation step. least-hydrophobic mumtv polypeptides (p23, p16) and the slightly hydrophobic p27 were separated from moderately hydrophobic proteins gp47 and p12 by passage through octylimino (c(8))-agarose; the gp47 and p12 could be removed from the matrix by elution with ethylene glycol, whereas the most ... | 1979 | 90171 |
| polyribonucleotide inhibition of ribonucleic acid directed deoxyribonucleic acid polymerase of mouse mammary tumor (type b) virus and simian sarcoma (type c) virus. | 1979 | 90331 | |
| virus-like particles and macromolecules in human milk and breast tumors. | relevant data pertaining to present evidence for virus-like particles and virus-related macromolecules in human milk and breast tumors are presented. a critical review and discussion of reported observations concerning virus-related macromolecules will include rna-directed dna polymerase, viral antigens, and rna related to murine mammary tumor virus and/or mason-pfizer monkey virus. from the standpoint of clinical applications, the finding of viral-related antigens in human breast tumors and evi ... | 1979 | 92388 |
| establishment of a c3hf mammary tumor cell line expressing endogenous mouse mammary tumor virus: antigenic and genetic relationships of this virus with highly oncogenic mouse mammary tumor viruses. | a single-cell clone of c3hf mammary tumor cells (clone 14) was developed into a continuous cell line expressing high levels of endogenous mouse mammary tumor virus (mmtv) with less than 0.1% murine leukemia virus expression. comparison of the c3hf mmtv protein profile on sodium dodecyl sulfatepolyacrylamide gel electrophoresis with that of c3h mmtv revealed that the protein content of the two viruses was quite similar. however, oligonucleotide fingerprints obtained of mmtv 70s rna revealed that ... | 1979 | 92576 |
| presence of human milk particle--specific antigens in malignant human breast tumor tissues. | 1979 | 93088 | |
| hormone-responsive genes of the mouse mammary tumor virus. | by optimal hormonal treatment the production of exogenously transmitted mmtv can be stimulated in vitro to different degrees, depending on cultivation conditions and origin of tumor cells. moreover, after appropriate hormonal treatment, endogenous mmtv-y can be rescued from primary cell cultures derived from dimethyl benzanthracene- and hormone-induced c57bl/10 mouse mammary adenocarcinoma, as determined by reverse transcriptase assay, distribution of 3h-uridine-labelled viral particles, immunof ... | 1979 | 94006 |
| a human breast tumor cell line (bt-474) that supports mouse mammary tumor virus replication. | a human breast tumor cell line bt-474 derived from an invasive ductal carcinoma was experimentally infected in vitro with a mouse mammary tumor virus from the tiii strain (riii-mumtv). the virus that replicated in the human cells was characterized as a mouse virus by immunofluorescence, electron microscopy and the presence of a specific rna-directed dna polymerase. the cells themselves were human as per the karyotype and isoenzyme migration patterns. it is concluded that human cells are suscepti ... | 1979 | 94035 |
| mice with spontaneous mammary tumors develop type-specific neutralizing and cytotoxic antibodies against the mouse mammary tumor virus envelope protein gp52. | sera from c3h mammary tumor-bearing mice contain cytotoxic antibodies for mouse mammary tumor virus (mmtv)-producing cells, based on (51)cr release in a complement-dependent serum cytotoxicity assay. the cytotoxic antibodies could be absorbed by purified c3h mmtv gp52 and c3h mmtv-infected cat cells (c3h [mmtv] crfk) containing cell surface mmtv gp52. however, purified mmtv p27 and uninfected crfk cat cells were negative. absorption of the sera with gr (mmtv) crfk cells also removed all of the c ... | 1979 | 94356 |
| mouse mammary tumor virus (mmtv) antigen(s) are present on b lymphocytes of balb/c mice. | immunofluorescence studies using a polyvalent anti-mmtv serum revealed the presence of mmtv antigen(s) on the surface of spleen cells from the low mammary tumor incidence mouse strain balb/ccrgl. upon separation of the splenocytes on nylon-wool columns the populations of cells exhibiting positive fluorescence were nylon-adherent. these cells were considered to be b lymphocytes by the following criteria: presence of surface immunoglobulin (slg), absence of thy-1 antigens, enhanced responses to b- ... | 1979 | 94593 |
| an unlabeled antibody macromolecule technique using hemocyanin for the identification of type b and type c retrovirus envelope and cell surface antigens by correlative fluorescence, transmission electron, and scanning electron microscopy. | the present resolution (75-100 a) of the conventional scanning electron microscope (sem) and its ability to image the surfaces of large numbers of whole cells in situ permit the approach of problems such as viral and cell surface antigen localization by immunological labeling with visual markers. identification of virus and cell surface antigens in situ has been accomplished in indirect reactions by unconjugated markers. hemocyanin (hcy) from whelk, busycon canniculatum, has been developed as an ... | 1979 | 117048 |
| identification, partial purification and biochemical characterization of gamma-glutamyltranspeptidase present as a membrane component in skimmed milk and milk fat-globule membranes, and in mammary-tumour virus from the milk of infected mice. | the enzyme gamma-glutamyltranspeptidase was reproducibly found to be associated with mouse milk particles; it is present in milk fat-globule membranes and mouse mammary-tumour virus of infected swiss mice, also in particles from the milk of uninfected mice. the enzymatic activities observed range among the highest reported for mammalian tissues. the enzyme was partially purified from mouse mammary-tumour virus, and from milk fat-globule membranes. the molecule requires the presence of detergents ... | 1979 | 36916 |
| unlinked control of multiple glucocorticoid-induced processes in htc cells. | htc cell variants chosen for their lack of tyrosine aminotransferase (ec 2.6.1.5) (tat) induction by glucocorticoids were tested for interrelated effects on other glucocorticoid responses: tat induction by dibutyryl cyclic amp (dbcamp) +/- dexamethasone, glutamine synthetase (gs) induction, cyclic nucleotide phosphodieterase (pde) suppression, inhibition of alpha-aminoisobutyric acid (aib) uptake, inhibition of plasminogen activator (pa), and induction of mouse mammary tumor virus (mtv). loss of ... | 1979 | 39858 |
| posttranscriptional regulation of glucocorticoid-regulated functions. | relying heavily on studies of tat regulation in cultured rat hepatoma cell lines, we have attempted in this brief review to discuss possible mechanisms for posttranscriptional regulation of glucocorticoid-sensitive enzymes and to chronicle the evidence for and against posttranscriptional mechanisms for specific enzyme induction by glucocorticoids. initially, mechanisms were considered that would reconcile results showing sensitivity of both induction and deinduction of tat to inhibitors of rna s ... | 1979 | 40116 |
| large-scale production of mouse mammary tumor virus in the absence of endogenous murine leukemia virus. | a system for the large-scale production and purification of mouse mammary tumor virus in the absence of detectable endogenous murine leukemia virus is described. by utilizing the mm5mt/c1 cell line established from an adenocarcinoma of a c3h mouse, the continuous production of over 25,000 liters of mouse mammary tumor virus-containing tissue culture fluids has been achieved. by the strict adherence to well-defined tissue culture conditions, mammary tumor virus production was accomplished without ... | 1979 | 83813 |
| cellular immunity to tumor-associated antigens of transplantable mammary tumors of c3h/hen mice. | 1979 | 83909 | |
| a new virion precipitation test for oncovirus envelope antigens which detects common antigenic determinants in mammalian type-c viruses and mason-pfizer monkey virus. | a method for the study of oncovirus envelope antigens was developed, bases on the precipitation of intact virions by a double antibody technique. the amount of precipitated virus was then measured as reverse transcriptase activity. the method was designated the virion precipitation test (vpt). it has been used for titration of antibodies to envelope antigens of oncoviruses. the study of envelop antigens of 11 different oncoviruses permitted their differentiation into the following groups: (1) mu ... | 1979 | 86521 |
| human breast carcinoma antigen is immunologically related to the polypeptide of the group-specific glycoprotein of mouse mammary tumor virus. | we have shown [mesa-tejada, r., keydar, i., ramanarayanan, m., ohno, t., fenoglio, c. & spiegelman, s. (1978) proc. natl. acad. sci. usa 75, 1529--1533] that an antigen immunologically related to gp52, a 52,000-dalton glycoprotein of the mouse mammary tumor virus, can be identified in sections of human breast cancer by means of an indirect immunoperoxidase technique. the specificity of the reaction was established by absorption experiments which revealed that only purified gp52, or material cont ... | 1979 | 88056 |
| virolysis of mouse mammary tumor virus by sera from breast cancer patients. | all type c retroviruses are lysed by human serum in apparently antibody-independent, complement-mediated reactions. in contrast, we have now determined that the mouse mammary tumor virus (mmtv), a type b retrovirus, is not disrupted by normal human serum. mmtv was lysed, however, when rabbit antibody to whole mmtv was added to the serum. by taking advantage of this dependence of mmtv lysis on specific antibody, a virolytic assay was developed, based on the measurement of reverse transcriptase re ... | 1979 | 88736 |
| the purification and characterization of a major glycoprotein of the murine mammary tumor virus. | 1979 | 88912 | |
| purification of murine oncornaviral phosphoproteins using alkyl agarose derivatives.. | methods for the purification of both murine mammary tumor (type b) and murine leukemia (type c) oncornaviral phosphoproteins are described, in which chromatography on alkyl-agarose derivatives is used as the primary fractionation step. gel filtration or ion exchange chromatography on phosphocellulose was the only subsequent step required for the purification of the type b and type c viral proteins, respectively. the two-step protocols also resulted in the co-purification of a low molecular weigh ... | 1979 | 220261 |
| differential distribution of mouse mammary tumor virus-related sequences in the dna's of rats. | 1979 | 220450 | |
| longterm effects of neonatal anterior hypophysial isografts on the mammary gland of mammary tumor virus-expressed mice. | 1979 | 220619 | |
| serological identification of viral and virus-related antigens on dba/2 mouse leukemia lymphocytes. | allogenic, semisyngeneic and syngeneic sera of animals immunized with ml-positive leukemia l1210 cells, besides anti-ml antibodies, contain antibodies which react with gross cellular surface antigen. ml antigen and gross cellular surface antigen were shown by the immunoferritin test in electron microscopy, and by the blocking test, to be situated on different parts of the cell surface. no budding viral particles were found on the areas occupied by these antigens. by distinguishing the ml antigen ... | 1979 | 220930 |
| immunological cross reaction between sera from patients with breast cancer and mouse mammary tumor virus. | sera of japanese women with breast cancer and without disorders of the mammary gland gave positive immunofluorescence reaction with mouse mammary tumor cells (mmt cells) producing type-a and type-b virus particles. among these, 55.1% (49/89) of the sera from patients with breast cancer reacted with mmt cells, whereas 60% (3/5) of the sera from patients with benign mammary hyperplasia (2 of 3 mastopathies, 1 of 2 cystosarcoma phyllodes), 30% (12/40) of the patients with other than breast cancer ( ... | 1979 | 221302 |
| cell-free synthesis of mouse mammary tumor virus pr77 from virion and intracellular mrna. | mouse mammary tumor virus (mumtv) was purified from two cell lines (gr and mm5mt/c1), and the genomic rna was isolated and translated in vitro in cell-free systems derived from mouse l cells and rabbit reticulocytes. the major translation product in both systems was a protein with the molecular weight 77,000. several other products were also detected, among them a 110,000-dalton and in minor amounts a 160,000-dalton protein. all three polypeptides were specifically immunoprecipitated by antiseru ... | 1979 | 221668 |