| analysis of glucocorticoid-inducible genes in wild-type and variant rat hepatoma cells. | we present pharmacological and genetic evidence that regulation of different genes by glucocorticoid hormones in the rat hepatoma cell line, htc, occurs in a coordinate manner. we have analyzed the responses of four different glucocorticoid-inducible proteins, tyrosine aminotransferase [l-tyrosine:2-oxoglutarate aminotransferase (ec 2.6.1.5)], glutamine synthetase [l-glutamate:ammonia ligase (ec 6.3.1.2)], a secreted glycoprotein belt i, and the mouse mammary tumor virus (mmtv)-encoded protein ( ... | 1983 | 6135149 |
| induction of the acute-phase reactant, alpha 1-acid glycoprotein, by glucocorticoids in rat hepatoma cells. | alpha 1-acid glycoprotein (alpha 1-agp), or orosomucoid, is shown to be inducible by glucocorticoids in htc rat hepatoma cells. immunoprecipitation of [35s]methionine pulse-labeled proteins from these cells reveals secreted proteins of mr = 35,000-48,000 (alpha 1-agp) and mr greater than 180,000, both of which are greatly enhanced by glucocorticoid treatment. the amount of alpha 1-agp-specific mrna in htc cells is greatly increased (at least 100-fold) in response to glucocorticoids. the new stea ... | 1983 | 6139269 |
| effects of insulin, dexamethasone and phorbol ester on virus production in cultivated dba/2 mouse leukemia (mla) cells. | the in vitro production of intracytoplasmic oncovirus a-particles and of atypical mammary tumor virus (mlav) from a line of dba/2 mouse leukemia (mla) cells were compared in the presence of insulin, dexamethasone and 12-0-tetradecanoyl-phorbol-13-acetate (tpa), which are known to stimulate the synthesis of mouse mammary tumor virus. high amounts of a-particles were recovered from cells cultivated in the presence of dexamethasone (1 microgram/ml) as compared to untreated controls; in contrast, th ... | 1983 | 6140829 |
| isolation and characterization of the rat tyrosine aminotransferase gene. | tyrosine aminotransferase (tat; l-tyrosine:2-oxoglutarate aminotransferase, ec 2.6.1.5) from rat liver is subject to glucocorticoid, camp, and developmental control. to study the underlying regulatory mechanisms, the tat structural gene was isolated from a lambda bacteriophage rat dna library. heteroduplex analysis revealed that the 2.4-kilobase-long tat mrna is encoded by a gene that extends over 11 kilobases and is interrupted by 11 introns. to characterize the presumptive control region, the ... | 1984 | 6143318 |
| interspecies radioimmunoassay for the major internal protein of mammary tumor viruses. | | 1980 | 6153487 |
| c3h/hen mammary tumor-bearing mice develop type-specific neutralizing antibodies and group-specific precipitating antibodies for the mouse mammary tumor virus. | the development of mouse mammary tumor virus (mmtv)-neutralizing antibodies in various strains of mice was measured by their ability to neutralize the focus-forming capacity of a kirsten sarcoma virus (c3h mmtv) pseudotype containing the mmtv envelope glycoprotein gp52. c3h/hen, but not gr/n and riii, mammary tumor-bearing mice were found to develop neutralizing antibodies to this pseudotype. in addition, non-tumor-bearing c3h/hen, gr/n, riii, nih swiss, c57bl/6, and balb/c mice and 13 feral mic ... | 1980 | 6154146 |
| immunological relationships of an endogenous guinea pig retrovirus with prototype mammalian type b and type d retroviruses. | a retrovirus endogenous to guinea pig cells was earlier shown to be morphologically similar to type b and type d prototype retroviruses. molecular hybridization techniques were used to show that guinea pig virus nucleotide sequences are endogenous to both domestic (cavia porcellus) and indigenous (cavia aperea) guinea pigs, but cannot be detected in the dna of either other hystricomorph rodents or other mammals tested. using radioimmunological techniques designed to detect interspecies relations ... | 1980 | 6154150 |
| detection of novel murine mammary tumor viruses by interspecies immunoassays. | radioimmunoassays were developed that can detect antigenic determinants common to mammary tumor viruses (mtv's) of four distinct mus species: m. musculus, m. cervicolor, m. cookll, and m. caroll. the radioimmunoassays were based on the immunologic cross-reactivity observed between the murine mammary tumor viruses (mumtv) of m. musculus and type b retrovirus isolated from m. cervicolor. both of the glycoproteins of mumtv (gp52, gp36) shared antigenic determinants with virions of m. cervicolor mam ... | 1980 | 6154165 |
| effects of interferon on the production of murine mammary tumor virus by mammary tumor cells in culture. | | 1980 | 6154379 |
| alterations of a mouse mammary tumor virus glycoprotein with interferon treatment. | the effects of exogenous mouse interferon on the mjy-alpha mammary tumor cell line chronically infected with mouse mammary tumor virus (mmtv) were examined. interferon at concentrations of 25 to 2,000 iu/ml in culture medium did not alter the growth rate or morphology of the cell layers. electron microscopic examination of interferon-treated cells indicated a decrease in the numbers of a-type and budding b-type particles of mmtv. however, the levels of extracellular mmtv virions in the culture s ... | 1980 | 6154805 |
| a human protein related to the major envelope protein of murine mammary tumor virus: identification and characterization. | a human milk protein was isolated to apparent homogeneity and shown to be immunologically related to gp55, the major envelope glycoprotein of murine mammary tumor virus. through the development of ultrasensitive protocols, which have wide applicability, immunological relatedness was corroborated by the demonstration of homologous protein sequences between the human and viral proteins. | 1980 | 6154929 |
| monoclonal antibodies identify individual determinants on mouse mammary tumor virus glycoprotein gp52 with group, class, or type specificity. | hybrid cell lines producing monoclonal antibodies against the c3h strain of mouse mammary tumor virus (c3h mmtv) were prepared by the fusion of mouse myeloma cells with the lymphocytes of balb/c mice that were immunized with c3h mmtv. approximately 10% of the hybrid cells initially plated after cell fusion produced immunoglobulins that reacted in antibody-binding assays with c3h mmtv; 40 of these cells were cloned, and 6 eventually yielded stable cell lines. high concentrations of monoclonal ant ... | 1980 | 6155475 |
| [effect of interferon on the expression of mouse mammary tumor virus (mmtv) in gr cells in culture]. | interferon treatment of gr cells markedly inhibits the production of mmtv as quantitated by hybridization of its viral rna in the cell culture medium. the level of intracellular viral rna and its rate of synthesis are however not modified by interferon. the intracellular levels of the major viral proteins as measured by immunoprecipitation remain unchanged. the intracellular level of the viral reverse transcriptase activity is reduced by about 40% as compared to more than 95% in the cell culture ... | 1980 | 6155982 |
| possible diagnostic implications of a mammary tumor virus related protein in human breast cancer. | | 1980 | 6156755 |
| [changes in the properties of mammary factor carcinomas of c3h strain mice treated with exogenous rna]. | | 1980 | 6156814 |
| trna's and priming of rna-directed dna synthesis in mouse mammary tumor virus. | the low-molecular-weight rnas of mouse mammary tumor virus (mumtv) were examined by two-dimensional acrylamide gel electrophoresis. unlike other retroviruses, mumtv was found to contain only two major fractions of trna. these have been fully characterized and shown to correspond to the published sequences for trna1+2lys and trna3lys. by determining which of these trna's was most tightly associated with the mumtv genome and which of them acquired label from [alpha-32p]deoxynucleoside triphosphate ... | 1980 | 6157839 |
| synthesis in high yield of complementary dna of retroviral rna. | mouse mammary tumor virus rna was transcribed in vitro with avian myeloblastosis virus reverse transcriptase in the presence of calf thymus dna oligomers. the yield of cdna was markedly enchanced by increasing the concentration of the enzyme as well as primers in the reaction mixture. the average size of cdna was approximately 200 residues, and it was not affected by the concentration of deoxynucleoside triphosphates when saturating concentration of enzyme was used. nearly all of the viral seque ... | 1980 | 6158040 |
| search for retrovirus-like particles in human breast cancer cells in culture. | we have recently established four new human breast cancer cell lines that were characterized as being of human mammary origin. we examined these cell lines for particles morphologically resembling retroviruses by electron microscopy, for extracellular and intracellular particles containing high-molecular-weight rna and rna-directed dna polymerase by biochemical assays, and for mouse mammary tumor virus (mmtv)-related sequences in the cell genomes by molecular hybridization. an extensive search f ... | 1980 | 6162539 |
| type-specific determinants on proteins of an endogenous c3h mouse mammary tumor virus (mmtv) distinguish this virus from highly oncogenic exogenous mmtvs. | | 1981 | 6164153 |
| serological definition of individually distinct surface antigens in mouse mammary carcinomas. | | 1980 | 6164557 |
| protein a assay for mouse mammary tumor virus gp52 determinants on murine and human mammary tumor cells. | | 1981 | 6166119 |
| sequence determination of the 3' end of mouse mammary tumor virus rna. | 70s rna has been prepared from mouse mammary tumor virus (mmtv) produced by the gr tumor cell line. after denaturation for 3 min at 60 degrees c the rna was applied to a sucrose gradient and molecules sedimenting between 10-16s were selected and passed over an oligo-dt cellulose column. the poly a containing rna fraction was used as a template for the synthesis of complementary dna with reverse transcriptase in the presence of dideoxynucleoside triphosphates. oligo-nucleotides p(dt)7rg, p(dt)7ra ... | 1981 | 6166850 |
| interferon-mediated inhibition of mouse mammary tumour virus (type b) and mouse leukaemia virus (type c) in the same culture. | the sensitivity of mouse mammary tumour virus (mmtv) and murine leukaemia virus (mulv) to interferon was tested by investigating the effect of interferon in cultures of mouse mammary tumour cells simultaneously synthesizing the two viruses. the dose-response curves showed that the extracellular production of both viruses by these cells was equally inhibited by interferon treatment. in contrast, the intracellular steady-state concentration of virus-specific rna of both mmtv and mulv was not signi ... | 1981 | 6167668 |
| [hormone-dependent expression of oncovirus genomes in stable mouse mammary cancer cell line gr and riii]. | the expression of mumtv and mulv major polypeptides and extracellular revertase activity (ra) in relation to the treatment with insulin (ins), dexamethasone (d) or both hormones was studied in four clones derived from two mammary carcinoma (mc) stable cell lines, riii/mt and gr/mt. in the cells growing in media without hormonal supplementation or with either insulin or dexamethasone alone the expression of p27 mumtv was poor, in cultures treated with dexamethasone alone a slight increase in mg++ ... | 1981 | 6168117 |
| use of the immune adherence hemagglutination test for titration of breast cancer patients' sea cross-reacting with purified mouse mammary tumor virus. | ninety-two sera from patients with breast cancer, 42 sera from patients with neoplastic diseases other than breast cancer and 59 sera from apparently healthy women were examined by means of the immune adherence hemagglutination (iaha) test using purified mouse mammary tumor virus (mmtv) fron rii mouse milk. it was found that 36.4% (34/96) of the sera from breast cancer patients, 7.1% (3/42) of the sera from patients with other neoplastic diseases and 5.1% (3/59) of the sera from apparently healt ... | 1981 | 6168514 |
| immunological characterization of a low oncogenic mouse mammary tumor virus balb/cniv mice. | antigenic determinants of mouse mammary tumor virus (mumtv) from the low-mammary-tumor-incidence strain balb/cniv were compared by competition radioimmunoassay with those of mumtv's isolated from several high- and low-mammary-tumor-incidence mouse strains, using rabbit hyperimmune sera against balb/cniv mumtv and against mumtv from the high-mammary-tumor-incidence strain balb/cfc3h. using anti-balb/cfc3h serum in competition radioimmunoassay, balb/cniv mumtv lacked antigenic determinants present ... | 1981 | 6169849 |
| topographical analysis of viral epitopes using monoclonal antibodies: mechanism of virus neutralization. | | 1981 | 6170162 |
| [possible association between oncoviruses and human breast tumors]. | | 1981 | 6170188 |
| dexamethasone effect on the growth rate, the plasminogen activator, and the mmtv rna dependent dna polymerase in a mouse mammary tumor cell line. | | 1981 | 6171281 |
| tumor associated markers in breast cancer. | | 1980 | 6172278 |
| immunological characterization of a mammary tumour virus from swiss mice: multiple epitopes associated with the viral gene products. | the major antigens of a mouse mammary tumour virus (mmtv) isolated from the milk of exogenously infected mb+ swiss mice were compared with the viral components of other mmtv strains by using the methodology developed by teramoto et al. (1977 a). the anti-gp47 (swiss) serum differentiated between type- and group-specific antigenic determinants on the major glycoprotein; two distinct type-reactivities were demonstrated, one of them being shared by the mmtvs (swiss) and (riii), and the other by the ... | 1981 | 6172552 |
| monoclonal antibodies as immunospecific probes for virus and cell surface antigen localization with the unlabeled antibody hemocyanin bridge: a review. | hemocyanin (hcy) from whelks, busycon canniculatum has been developed as a visual marker for the identification of virus and cell surface antigens by the correlative techniques of fluorescence microscopy, tem and sem. a series of hybridomas producing monoclonal antibodies that allow the identification of type-, group-, and class-specific antigenic determinants on the major envelope glycoprotein of mouse mammary tumor virus (mmtv) gp 52 and two group-specific monoclonal antibodies to mmtv gp 36 h ... | 1981 | 6172845 |
| detection of type-specific antigenic determinants of murine mammary tumor viruses with cell-mediated immune assays. | | 1982 | 6174985 |
| the use of monoclonal antibodies in virology. | | 1982 | 6177742 |
| ml antigen of dba/2 mouse leukemias: expression of an endogenous murine mammary tumor virus. | spontaneous, transplantable leukemias of dba/2 mice express an antigen (ml) which cross-reacts with antigens of murine mammary tumor virus (mumtv). the mumtv cross-reactive antigen of the dba/2 leukemias (ml cells) was found to be a glycoprotein of 78,000 molecular weight containing antigenic determinants of the major mumtv glycoprotein gp52. no mumtv particles were produced by the ml cells, although they did contain type a particles--the pronucleocapsids of mumtv. the ml antigen appeared to be ... | 1982 | 6178848 |
| monoclonal and polyclonal antibody studies of vsv(hrmmtv) pseudotypes. | | 1982 | 6179293 |
| interferon induced inhibition of mouse mammary tumor virus production. | treatment of murine cells chronically infected with mouse mammary tumor virus with interferon resulted in a marked inhibition of extracellular virus production. this inhibition occurred despite the lack of effect on the transcription or translation of viral rna. interferon treatment did not alter the steady-state level of intracellular viral rna as determined by hybridization of total cellular and polysomal poly(a) containing rna with mouse mammary tumor virus complementary dna. additionally, an ... | 1980 | 6180037 |
| co-expression and amplification of dihydrofolate reductase cdna and the escherichia coli xgprt gene in chinese hamster ovary cells. | we have transformed chinese hamster ovary cells with a plasmid containing mouse dihydrofolate reductase (dhfr) cdna and the escherichia coli xanthine-guanine phosphoribosyl transferase (xgprt) gene under the control of the mouse mammary tumor virus and sv40 early promoters, respectively. selection for the expression of xgprt using the dominant selection scheme described by mulligan and berg yields clones that simultaneously express dhfr. growth of these cells in progressively increasing concentr ... | 1981 | 6180118 |
| effects of interferon on the expression of mouse mammary tumour virus in gr cells. | the effects of interferon treatment on the expression of murine mammary tumour virus (mumtv) by a continuous mammary tumour cell line of gr mouse were investigated. interferon markedly inhibited the excretion of mumtv particles in the culture media as measured by hybridization of virus-specific rna and virus-associated reverse transcriptase activity. there was no inhibition of virus rna and protein synthesis in those conditions. the steady-state level of intracellular virus rna and its rate of s ... | 1982 | 6182267 |
| dependence of the structural mumtv protein expression on hormone-induced murine mammary carcinoma gr/mt cell differentiation in vitro. | effect of three hormones on the clonal cell line, originating from the stable gr/mt mammary carcinoma (mc) cell line was studied. in the hormones free media the cells had fibroblast-like shapes. normal differentiation markers and mumtv protein processing could not be revealed. insulin favors epithelial cell shape and growth pattern induction, thy 1.2 antigen expression, as it was shown by fif test and increased clonogenicity in semisolid medium. prolactin produces elongated, fusiform cells, milk ... | 1982 | 6184623 |
| monoclonal antibodies to three epitopic regions of feline leukemia virus p27 and their use in enzyme-linked immunosorbent assay of p27. | three different monoclonal antibodies were developed against the major core protein (p27) of feline leukemia virus (felv). each antibody was directed against a different epitope of the species-specific portion of felv-p27. the 3 antibodies reacted with 5 different isolates of felv but not with 7 other retroviruses (mulv (rauscher), mulv (akr), mpmv, mmtv, smrv, baev, rd 114). these monoclonal antibodies could readily be adapted to an enzyme-linked immunosorbent assay (elisa) for the specific mea ... | 1983 | 6186744 |
| strain-specific determinants on the major phosphoprotein of murine mammary tumor viruses. | the major phosphoprotein (p23) of murine mammary tumor virus (mumtv) was purified for c3h virus, using a combination of alkyl agarose chromatography and gel filtration. monospecific antiserum was raised against glutaraldehyde crosslinked polymers of purified p23, and the antiserum was then used with iodinated p23 to develop a competition radioimmunoassay. phosphoprotein p23 was shown to contain both group- and type-specific antigenic determinants in assays using detergent-disrupted virions of mu ... | 1983 | 6187126 |
| structural analysis of a 1.7-kilobase mouse mammary tumor virus-specific rna. | we have detected a mouse mammary tumor virus (mmtv)-specific 1.7-kilobase (kb) polyadenylated rna in mammary glands of several mouse strains. in balb/c mice, it is the only mmtv-specific rna species present. c3h and gr mammary glands and tumors contain, in addition, 3.8- and 7.8-kb mmtv rnas. nuclease s1 analysis was performed to map 1.7-kb polyadenylated rna. it contains predominantly long terminal repeat (ltr) sequences. the 5' end maps approximately 134 nucleotides upstream from the 3' end of ... | 1983 | 6188860 |
| decrease in mammary tumour incidence in virgin c3h mice given interferon only while suckling. | a high proportion of females of the c3h strain of mice develop tumours of the mammary gland which are caused by mouse mammary tumour virus (mmtv) transmitted through the milk. we have examined whether administration of mouse interferon (ifn) to nursing mothers and/or their suckling offspring only during the period of nursing, can affect the incidence of tumours developing in these animals. in two separate experiments, animals receiving ifn by direct injection while suckling, and remaining virgin ... | 1983 | 6190493 |
| proteins encoded by mouse mammary tumour virus. | | 1983 | 6196157 |
| a viral coat glycoprotein (gp52mumtv) has detergent-sensitive and detergent-resistant epitopes in the same molecule. | two monoclonal antibodies (iib5 and ic12) specific for the gp52 coat glycoprotein of mouse mammary tumor virus are directed against epitopes on the gp52 that are sensitive to a non-ionic detergent, nonidet p-40. there are other epitopes on this molecule that are stable in the detergent, as seen in immunoprecipitation studies with other anti-gp52 monoclonal antibodies (ve7, iiia1, ivc11). | 1983 | 6197632 |
| approaches to the study of hormonal regulation of gene expression. | | 1983 | 6199281 |
| antigenic determinants in a virus-induced mouse mammary tumor recognized by cell-mediated immune assays. | purified tumor cell membrane (ptcm) fractions from spontaneous balb/cfc3h mammary adenocarcinomas elicit blastogenic responses in spleen cells of tumor-bearing mice. previous studies have demonstrated that splenic t-cells are the major responding cell population but have not clarified whether the antigens responsible for the reactions are exclusively viral in origin or may involve nonviral tumor-associated antigens (taa). pretreatment of ptcm preparations with polyvalent anti-murine mammary tumo ... | 1984 | 6199544 |
| monoclonal antibodies to tumor-associated antigens. | experience is described in applying monoclonal antibodies (mabs) to immunohistology, epitope analysis on antigens, and radioimmunoassay. the antibodies (provided by international laboratories) used in the experiments described were directed to the mouse mammary tumor virus, a cell surface component of melanoma cells, several proteins of the human milk fat globule membrane (as markers for cell differentiation in breast cancers) as well as to carcinoembryonic antigen (cea). at least three antigeni ... | 1984 | 6200086 |
| glucocorticoid hormone interactions with cloned proviral dna of mouse mammary tumor virus. | the molecular details of glucocorticoid hormone regulation of expression of the mouse mammary tumor virus (mmtv) proviral gene have been investigated. cloned proviral dna was introduced into cultured cells by a gene transfer procedure. dna acquired by transfection was shown to be expressed in a hormone regulated fashion. the proviral dna was fragmented and recombined in vitro with an indicator gene to delimit the hormone response sequence. inducibility of the indicator gene (thymidine kinase gen ... | 1984 | 6200702 |
| expression of an 86-kilodalton glycoprotein in an idiopathic mammary adenocarcinoma of a balb/c mouse. | an epithelial cell line (balb/c-st) was established from a mammary adenocarcinoma that developed spontaneously in a 20-month-old balb/c mouse. like uninfected normal tissues, the cell line was found to contain three endogeneous murine mammary tumor virus (mumtv) proviruses, but mumtv particles and antigens were not detected. the cultured cells, after being inoculated subcutaneously, produced tumors in syngeneic mice, and sera from a high percentage of the tumor-bearing mice specifically immunopr ... | 1984 | 6204336 |
| rna-directed dna polymerase activity in human breast cancer biopsy specimens. relation to estrogen receptor protein. | the expression of a mouse mammary tumor virus is inducible by hormones, and the virus contains a hormone-responsive element. viral particles and rna-directed dna polymerase (rddp, ec 2.7.7.7; reverse transcriptase) are both detectable in human breast tumors but the frequency and significance of these findings are unknown. breast tumor biopsy specimens (from either the primary site or a metastasis), frozen in liquid nitrogen at the time of surgery, were routinely obtained to determine estrogen re ... | 1984 | 6205338 |
| glucocorticoid-mediated induction of alpha 1-acid glycoprotein: evidence for hormone-regulated rna processing. | we have studied the glucocorticoid-mediated accumulation of alpha 1-acid glycoprotein (agp) in mrna in htc rat hepatoma cells. in contrast to the well-characterized primary response of mouse mammary tumor virus, in vitro transcription assays in isolated nuclei show that the rate of transcription of the agp gene is high even in the absence of hormone. despite the constitutive transcription of the agp gene, no detectable agp rna can be found in either the cytoplasm or the nuclei of untreated cells ... | 1984 | 6205392 |
| proteins encoded by the long terminal repeat region of mouse mammary tumor virus: identification by hybrid-selected translation. | the long terminal repeat (ltr) region of mouse mammary tumor virus (mmtv) is known to contain an open reading frame of sufficient length to code for a protein of 36,000 mr. the coding capacity of the 3' sequences of mmtv genomic rna has been demonstrated by in vitro translation studies, which have reported the synthesis of four related proteins: p36, p24, p21, and p18. these proteins are overlapping translation products of the same open reading frame, with the smaller ones initiating at internal ... | 1984 | 6206233 |
| ott f. e. mühlbock 1906--1979. | | 1980 | 6243088 |
| mammary tumors from balb/c mice with a reported high mammary tumor incidence have acquired new mammary tumor virus dna sequences. | | 1980 | 6243194 |
| mammary tumorigenesis in 7,12-dimethybenzanthracene-treated c57bl x dba/2f f1 mice. | | 1980 | 6243251 |
| an enzyme-linked immunoassay for the detection of antibodies to the mouse mammary tumor virus: application to human breast cancer. | an enzyme-linked immunoassay (elisa) was developed, using the mouse mammary tumor virus (mmtv) fixed to wells of a microtiter plate, for the determination of antibodies to mmtv. the intensity of the final color change was dependent upon virus or viral antibody concentration. mmtv antibody was readily detectable in sera diluted as much as 1 : 2800. fixed mmtv bound antibodies to an internal viral protein (p 28) as well as to viral envelope components (gp 52, gp 34), demonstrating that the virus w ... | 1980 | 6243334 |
| human lymphocyte blastogenesis responses to mouse mammary tumor virus. | | 1980 | 6243719 |
| leukocyte migration inhibition among breast cancer patients in response to various oncogenic viruses. | the direct leukocyte migration inhibition (lmi) test was done with leukocytes from healthy women and from patients with primary operable breast cancer, benign breast disease, or head and neck cancer. purified preparations of murine mammary tumor virus (mumtv), mason-pfizer monkey virus (mpmv), and murine leukemia virus (mulv) were used. for each virus, the lowest 10th percentile of the lmi responses of controls was used to discriminate positive from negative responses. leukocytes from 46 of 94 ( ... | 1980 | 6243720 |
| phorbol ester-mediated stimulation of the synthesis of mouse mammary tumour virus. | | 1980 | 6243751 |
| methylation of milk-borne and genetically transmitted mouse mammary tumor virus proviral dna. | the 5-methylcytosine content of mouse mammary tumor virus (mmtv)-specific dna sequences acquired by both milk-borne infection and genetic transmission was determined for both normal and neoplastic tissues of the mouse. using the restriction endonuclease msp i, which cleaves at the recognition sequence 5'-ccgg, and its isoschizomer hpa ii, which is inhibited by methylation of the cytosine base of the cpg dinucleotide, it can be demonstrated that mmtv proviruses acquired via germ line infection ar ... | 1980 | 6244894 |
| development of cell-mediated antiviral immunity and macrophage activation in c3h/hen mice infected with mouse mammary tumor virus. | | 1980 | 6245137 |
| differential host ranges for in vitro infectivity of mouse mammary tumour viruses. | host-range variants of mouse mammary tumour viruses (mmtvs) have previously been shown to productively infect cells of several species in vitro (howard & schlom, 1978). we report here that cell lines have been identified which exhibit differential restriction for replication of different mmtv variants. in addition, a cell line has been identified that changes as a function of passage in culture from being permissive to being restrictive to infection with mmtvs. mmtvs propagated in both murine an ... | 1980 | 6245180 |
| number and location of mouse mammary tumor virus proviral dna in mouse dna of normal tissue and of mammary tumors. | the southern dna filter transfer technique was used to characterize the genomic location of the mouse mammary tumor proviral dna in different inbred strains of mice. two of the strains (c3h and cba) arose from a cross of a bagg albino (balb/c) mouse and a dba mouse. the mouse mammary tumor virus-containing restriction enzyme dna fragments of these strains had similar patterns, suggesting that the proviruses of these mice are in similar genomic locations. conversely, the pattern arising from the ... | 1980 | 6245257 |
| prevalence and distribution of murine mammary tumor virus antigen detectable by immunocytochemistry in spontaneous breast tumors of wild mice. | mouse mammary tumor virus (mumtv) antigens were detected by immunoperoxidase cytochemistry in spontaneous breast tumors of wild mice from two widely separated areas of southern california. eleven of 25 (44%) tumors from lake casitas (lc) mice and 4 of 5 tumors from bouquet canyon mice were positive. included among the tumors lacking detectable mumtv antigen were well-differentiated type a and type b carcinomas as well as tumors with an atypical pattern. in the antigen-positive tumors the distrib ... | 1980 | 6245303 |
| organization and expression of endogenous murine mammary tumor virus genes in mice congenic at the h-2 complex. | | 1980 | 6245525 |
| epithelial cell junctions in primary and metastatic mammary tumors of mice. | | 1980 | 6245797 |
| expression of mammary tumour virus in late-appearing mammary carcinomas in presumed virus-free mice. | | 1980 | 6245888 |
| isolation of a series of novel variants of murine mammary tumor viruses with broadened host ranges. | we have previously isolated mouse mammary tumor virus (mmtv) host range variants by serial virus passage in feline cells. these variants productively infect cells of a broad range of species but replicate most efficiently in feline cells. we report here the isolation of a series of novel mmtv host range variants that have the ability to replicate with high efficiency in murine, rat, canine and human cells, respectively; these variants were isolated by serial virus passage in cells of each respec ... | 1980 | 6246012 |
| macrophage accumulation in mice is inhibited by low molecular weight products from murine leukemia viruses. | low m.w. extracts from three known oncogenic viruses, friend, moloney, and rauscher, inhibited the accumulation of macrophages at sites of delayed inflammatory reactions in mice. the potential biologic significance of these proteins is suggested by their potency: as little as 1.2 ng of viral protein inhibited (p less than 0.02) macrophage accumulation when injected at a site distant to the inflammatory reaction. a virus envelope protein fraction of 15,000 daltons (p15e) was likewise found to inh ... | 1980 | 6246170 |
| [viruses and the pathogenesis of collagen disease (author's transl)]. | | 1980 | 6247770 |
| rna virus associated antigen in human placenta. | using indirect immunofluorescence microscopy, it was demonstrated that human cytotrophoblast of six to ten weeks gestation contains mouse mammary tumor virus associated antigen. this antigen appeared predominantly in the periphery of the cells. | 1980 | 6247956 |
| correlation between the detection of specific mouse mammary tumor proviral sequences and the presence of pulmonary metastases in mice bearing spontaneous mammary tumors. | pulmonary metastases in c3h/he mice bearing spontaneous mammary tumors were detected and characterized by histological criteria and immunocytochemical staining for mouse mammary tumor virus antigens. the same lungs containing metastases were also positive when assayed for a specific subset of mouse mammary tumor virus proviral dna sequences. these sequences, termed tumor-associated sequences, have previously been shown to be present in the dna of spontaneous mammary tumors that arise before 1 yr ... | 1980 | 6248203 |
| age- and tumor-correlated changes in functional antibody responses to mtv in neonatally infected mice. | balb/cfc3h female mice (neonatally infected with mtv) possess several different specific antibody activities measured functionally by reactivity with mtv-associated antigens expressed on the surface of isologous mtv-induced mammary tumor target cells. all females when young develop serum antibody which can block specific t-cell cytotoxic activity of balb/cfc3h spleen cells; this activity remains detectable throughout life. in addition, recruiting antibody is found in the post-weaning stage. this ... | 1980 | 6248467 |
| quantification of mouse mammary tumor virus structural proteins in hormone-induced mammary tumors of low mammary tumor mouse strains. | the expression of the mouse mammary tumor virus (mmtv) in hormone-induced mammary tumors was investigated by means of a radioimmunoassay for two major mmtv proteins, gp52 and p27. mmtv proteins were isolated on lectin affinity- and ion-exchange chromatography columns. the purified viral proteins were electrophoretically homogeneous and retained immunoreactivity after labelling with 125iodine. standard competition assays showed that group-specific antigenic determinants were reacting. mammary tum ... | 1980 | 6248469 |
| presence of a proteolytic activity in murine mammary tumor virus. | | 1980 | 6248545 |
| murine mammary tumor virus deficient in the major glycoprotein: biochemical and biological studies on virions produced by a lymphoma cell line. | | 1980 | 6249031 |
| isolation and characterization of low-molecular-weight dna-binding proteins from retroviruses. | | 1980 | 6249039 |
| the ganglioside content of the milk fat-globule membrane and the mouse mammary-tumour virus isolated from the milk of infected mice. partial characterization of a new disialoganglioside. | the milk fat-globule membrane and the mouse mammary-tumour virus isolated from the milk of infected swiss mice have been investigated for their content in gangliosides. when compared on the lipid phosphorus basis, viral envelope is found to contain more than twice as much lipid-bound sialic acid as fat-globule membrane. the ganglioside patterns of these two structures appear rather similar, except for the occurrence in fat-globule membrane of a low ganglioside homolog, presumably gm2, not detect ... | 1980 | 6249587 |
| mouse mammary tumour virus-related antigens in core-like density fractions from large samples of women's milk. | | 1980 | 6249609 |
| lack of evidence for non-virion cell surface antigens on virally-induced murine mammary tumor cell. | | 1980 | 6250851 |
| localization of a gene for expression of mouse mammary tumor virus antigens in the gr/mtv-2- mouse strain. | the gr/mtv-2- mouse strain is congenic to the gr strain but lacks the mtv-2 gene for high amounts of mouse mammary tumor virus (mmtv) virion particles in the milk and early mammary tumors. with a sensitive competition radioimmunoassay for individual viral proteins of mmtv, substantial amounts of the gag proteins p27 and p10 could still be detected in extracts of the mammary glands of gr/mtv-2- mice, but essentially no viral envelope antigens. the genetic transmission of the mmtv gag expression i ... | 1980 | 6251153 |
| molecular and morphological evidence for type b retrovirus (oncornavirus) expression in human mammary carcinoma. an overview using scanning electron microscopy, immunoperoxidase staining, and transmission electron microscopy. | approximately 45% of human mammary carcinoma cases express an antigen which cross reacts in formalin fixed tissues with antiserum prepared against the purified 52,000 molecular weight structural glycoprotein (gp52) of mouse mammary tumor virus (mmtv). breast carcinoma immunoperoxidase marking is abolished by antiserum adsorption with mmtv. adsorption with murine leukemia virus failed to block immunoperoxidase marking. no correlation was seen in the cases analyzed between gp52-like antigen expres ... | 1980 | 6251536 |
| immunoelectron microscopic studies using monoclonal antibodies to mouse mammary tumor virus antigens as probes of the cell surface with the unlabeled antibody hemocyanin bridge. | | 1980 | 6251538 |
| stability of characters of mammary tumors in balb/cfriii mice. | the biological and morphological characteristics of mammary tumors in balb/c mice infected with riii mammary tumor virus (mtv) by foster nursing have substantially kept stable and unchanged after 20 years, 53 inbred generations and transfer of the strain from perugia to pisa. this suggests that the causal mtv keeps unaltered in time its biological properties. | 1980 | 6251587 |
| gene order of murine mammary tumor virus gag proteins and env proteins. | | 1980 | 6251618 |
| [detection of antigens immunologically related to the envelope antigens of mouse mammary gland cancer virus antigens in human breast cancer tissue]. | a highly sensitive method of electroimmunodiffusion in acetate cellulose films developed by g.i. abelev on the principle of isotachophoresis was used for the detection in human mammary gland carcinoma (hmgc) of an antigen related to envelope antigens of mouse mammary gland cancer (mmgc) virus. in 4 out of 10 hmgc cases, fractions of proteins with molecular weight about 50,000 d previously isolated in paag with sodium dodecyl sulphate were found to contain an antigen reacting with the antiserum t ... | 1980 | 6251635 |
| detection and characterization of mouse mammary tumor virus cell surface antigens: estimation of antigen abundance by protein a assay. | antisera against the following mouse mammary tumor virus (mmtv) structural proteins were used to detect mmtv cell surface antigens: (i) the 27,000-dalton nucleoid protein, p27; (ii) the 36,000-dalton envelope glycoprotein, gp36; and (iii) the 52,000-dalton exterior envelope glycoprotein, gp52. we report here the development of an adherent-cell isotopic staphylococcal protein a (spa) test (ispat) for mmtv structural proteins which allows for the detection of an mmtv membrane-associated antigen as ... | 1980 | 6252344 |
| murine mammary tumor virus structural protein interactions: formation of oligomeric complexes with cleavable cross-linking agents. | murine mammary tumor virus protein interactions in the intact virion structure were studied with the use of the cleavable cross-linking reagents dithiobis(succinimidyl propionate) and methyl 4-mercaptobutyrimidate hydrochloride. cross-linked oligomeric complexes of murine mammary tumor virus proteins were analyzed by two-dimensional gel electrophoresis. among the complexes most consistently formed were a heterodimer of the two glycoproteins gp36 and gp52, the homodimer of gp36, and the homotrime ... | 1980 | 6252348 |
| short gastric veins as the major portal of entry for milk-borne murine mammary tumor virus. | the flow pattern of the short gastric veins that drain the fundic portion of the stomach appeared to influence mammary tumorigenesis. in i and c57bl mice, strains that are highly resistant to murine mammary tumor virus (mumtv)-induced mammary tumorigenesis, the short gastric veins empty directly into the splenic vein outside the spleen, connecting with the portal system. in (c57bl x i)f1 mice, which are highly susceptible to mumtv-induced mammary tumorigenesis, the short gastric veins empty dire ... | 1980 | 6252362 |
| [genesis of breast cancer: a multifactorial etiology]. | | 1980 | 6252427 |
| [detection of mmtv gp52 in c3h and c3hf strain mice]. | immunofluorescence in paraffine sections demonstrated the difference in expression of the membrane glycoprotein of mouse mammary tumor virus (gp52) in two mouse sublines: c3h and c3hf. in the c3hf the glycoprotein becomes detectable in the mammary gland in the second part of pregnancy while in c3h line mature females before pregnancy. no viral glycoprotein could be found in the spleen, liver, kidneys and other organs in males and females of the two sublines or in c3h embryos. | 1980 | 6252698 |
| [increased immunologic reactivity against hepatoma 22a cells in mtv-infected c3h mice in comparison to mtv-free mice]. | some tumors of no mammary tissue origin (sarcoma, hepatoma) grew more effectively in mtv-free mice (c3hf) as compared with mtv-infected mice (c3h/he), whereas the tumors of mammary gland origin grew more rapidly in the latter ones. it has been shown that c3h/he mice develop a stronger specific immune reaction against hepatoma 22a cells than do c3h/f mice and that the animals of mtv-bearing subline exhibit a higher natural killer activity against these cells. | 1980 | 6252986 |
| construction and characterization of molecular clones containing integrated mouse mammary tumor virus sequences. | | 1980 | 6253190 |
| genomic location of mouse mammary tumor virus proviral dna in normal mouse tissue and in mammary tumors. | | 1980 | 6253191 |
| summary: molecular biology of viral oncogenes. | | 1980 | 6253205 |
| mammary tumor virus antigen expression in inbred mouse strains of european origin established in japan. | expression of the mammary tumor virus (mtv) antigen in the milk from inbred mouse strains maintained in japanese laboratories was investigated by means of the immunodiffusion test (id) and the results were compared with the incidence of mammary tumors in breeding females of identical strains. japanese strains tested were classified into two groups. the dd/tbr, ddd and kf strains were derived from "dd" stock mice, and they showed equally high incidences of mtv antigen expression in the milk, thou ... | 1980 | 6253345 |
| reevaluation of the effect of mouse mammary tumor virus infection on the balb/c mouse hyperplastic outgrowth. | the balb/c (c-) mouse hyperplastic outgrowth line (d1) was used to study murine mammary tumor virus (mumtv) expression in both d1 and tumors derived from d1. d1 was transplanted into virus-infected balb/cfc3h (c+) and virus-uninfected c- animals. in duplicate studies, tumor incidence was the same in both groups. however, the tumor latency period was longer for d1 transplanted into c+ mice (d1/c+) than for d1 transplanted into c- mice (d1/c-). mumtv was detected in 85% of d1/c+ outgrowths and in ... | 1980 | 6253710 |
| [viral etiology of breast cancer]. | | 1980 | 6253765 |