Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| endogenous mammary tumour virus dna varies among wild mice and segregates during inbreeding. | proviruses of the mouse mammary tumour virus (mmtv) endogenous to normal mice can be identified by molecular hybridisation and distinguished using restriction endonucleases. feral mice display marked heterogeneity with respect to the number of copies and the sites of insertion of endogenous mmtv-specific dna, with occasional mice apparently free of mmtv dna. several different mmtv proviruses present in laboratory mice have segregated like stable, independent genetic elements during the inbreedin ... | 1979 | 221817 |
| identification of the messenger rnas coding for the gag and env gene products of the murine mammary tumor virus. | full-length (35s) genomic rna from murine mammary tumor virus (mumtv) was translated in vitro, using a reticulocyte lysate system, into proteins of 105,000, 75,000, 65,000, 35,000, and 27,000 daltons. these proteins were all immunoprecipitable with a monospecific antiserum to the major viral core protein, p27, but not with antiserum to the major viral envelope glycoprotein, gp47. translation in vitro of rna of about 24s size extracted from mumtv yielded proteins similar in size and immunoreactiv ... | 1979 | 221904 |
| regulation of mouse mammary tumor viral rna synthesis in embryonal carcinoma cells and in teratocarcinoma derived myoblasts. | 1979 | 222273 | |
| integration of the dna of mouse mammary tumor virus in virus-infected normal and neoplastic tissue of the mouse. | we have used restriction endonucleases which cleave the dna of mouse mammary tumor virus (mmtv) at one site (eco ri) and several sites (pst i, sac i and bam hi) to study infection and mammary tumorigenesis in mice. proviruses acquired during infection of balb/c mice foster-nursed by virus-producing c3h females can be distinguished from the mmtv proviruses endogenous to uninfected balb/c mice by the nature of the fragments generated with pst i and bam hi. using this assay, we show that lactating ... | 1979 | 222456 |
| idiopathic mammary tumors in balb/c mice. | a colony of balb/c mice consisting of two sublines with a high incidence of mammary tumors was examined for the presence of a mammary tumor virus (mumtv). the mammary tumor incidences in the two sublines were 18% and 35% at average tumor age 19-20 months. over a period of 8 years, their milk at third to tenth lactations were monitored for the presence of mumtv antigen,and the milk and tumors were examined for the presence of b particles. neither antigen nor b particles were found. milk and tumor ... | 1979 | 222695 |
| the cause of species differences in mammary tumourigenesis: significance of mammary gland dna synthesis. | the causes of species differences in mammary tumourigenesis are briefly discussed from the genetical and environmental points of view, although no firm conclusions can be drawn. distinct differences in mammary gland dna synthesis were found between female mice and rats, which behave very differently in mammary tumourigenesis. based on the importance of mammary gland dna synthesis in mammary tumourigenesis, the differences in mammary gland dna synthesis between species is hypothesized to be a maj ... | 1979 | 223022 |
| vicinal relationships between the major structural proteins of murine mammary tumor virus. | 1979 | 223301 | |
| characterization of purified structural proteins of murine mammary tumor virus. | 1979 | 223309 | |
| effect of dexamethasone on expression of endogenous mouse mammary tumor virus sequences in balb/c tumor cell lines. | 1979 | 223313 | |
| immunohistochemical evidence for rna virus related components in human breast cancer. | the localization of antigenic components with cross-reactivity to a 52,000 dalton group specific glycoprotein (gp52) of the mouse mammary tumor virus (mmtv) in paraffin sections of human breast carcinomas is described using an indirect immunoperoxidase method. this method was first optimized on paraffin sections of mouse mammary tumors. the specificity of the reaction observed in the human tissues was established by absorption of the specific igg with: a) purified gp52; b) several relevant and i ... | 1979 | 223491 |
| virus particles in normal prostate tissues of mice from ten strains, with special reference to type-b virus particles. | prostate tissues of a total of 61 normal mice from 10 different strains, including high (c3h/dm, riii/dm, and a/dm) and low (balb/c/dm, c3hf/bi/dm, and c3hf/he/tex) mammary cancer, and high (akr/dm) and low (cba/j/cr, sjl/j/cr, and c57/bl/6/tex) leukemia strains were examined by electron microscopy for the presence of virus particles. these studies demonstrated that type-b virus particles were present in normal prostate tissues of some old mice from all the three high (c3h/dm, riii/dm, and a/dm) ... | 1979 | 223933 |
| structural analysis of the intracellular rnas of murine mammary tumor virus. | we have characterized murine mammary tumor virus (mumtv)-specific rna in several types of cells in which viral dna is transcribed into rna: cultured gr mouse mammary tumor cells, s49 lymphoma cells from balb/c mice, lactating mammary glands from c57bl/6 mice, and mink lung cells infected in vitro with mumtv. in all cell types studied, there are three distinct species of intracellular viral rna, with sedimentation coefficients of 35s, 24s, and 13s (or molecular weights of 3.1 x 10(6), 1.5 x 10(6) ... | 1979 | 224216 |
| immunocytochemical distribution of mouse mammary tumor virus antigens in balb/cfc3h mammary epithelium. | the distribution of mouse mammary tumor virus (mumtv) antigens was studied in normal, preneoplastic, and neoplastic mammary epithelia from female balb/cfc3h mice with the use of a polyvalent anti-mumtv serum and indirect immunoperoxidase techniques. the mumtv antigens were on the apical surface or in focal cytoplasmic aggregates or diffused throughout the infected cells. as much as 70% of all cells in adenocarcinomas and as much as 100% of all cells in preneoplastic hyperplastic alveolar nodules ... | 1979 | 224238 |
| generation of a mouse mammary tumor virus (mmtv) pseudotype of kirsten sarcoma virus and restriction of mmtv gag expression in heterologous infected cells. | 1979 | 224586 | |
| mouse mammary tumor virus infections: viral expression and tumor risk. | concentrations of murine mammary tumor virus (mumtv) antigen in the milk of individual naturally infected balb/cfc3h and balb/c mice given injections of mumtv were related to their risk of developing a mammary tumor. two distinct groups of mumtv-infected mice were identified. one group exhibited high viral antigen levels in their milk (greater than or equal to 100 micrograms/ml), whereas the other group exhibited low viral antigen levels in their milk (less than or equal to 3 micrograms/ml). mic ... | 1979 | 225501 |
| phosphorylation of murine mammary tumor virus precursor polypeptides. | phosphorylation of the murine mammary tumor virus (mumtv) structural proteins was studied in an mumtv-infected epithelial cell line derived from a balb/cf c3h mouse mammary tumor. immunoprecipitation of 32p-labeled cell extracts with monospecific anti-p27 serum revealed that phosphorylation occurred at the stage of the core-protein polyprotein precursor prp75. two forms of phosphorylated prp75 were found: one migrating with an apparent molecular weight of 80,000, and the other with a molecular w ... | 1979 | 225520 |
| identification of mouse mammary tumor virus-specific mrna. | complementary dna corresponding to the rna genome of mouse mammary tumor virus was used to identify viral rna contained in polysomes of a virus-producing mammary tumor cell line. separation of polysomal mrna by agarose gel electrophoresis, transfer of the rna to diazobenzyloxymethyl paper, and hybridization with 32p-labeled mouse mammary tumor virus complementary dna revealed three viral rna size classes of 10, 8.8, and 4.4 kilobases in length, respectively. | 1979 | 225528 |
| composition, arrangement and cleavage of the mouse mammary tumor virus polyprotein precursor pr77gag and p110gag. | 1979 | 226264 | |
| levels of mammary tumor virus proteins (mtvp27 and mtvgp52) in the milk of low and high mammary cancer mouse strains of japanese origin compared with european and american strains. | 1979 | 226487 | |
| antitumor immunity in breast cancer patients. biologic and therapeutic implications. | as judged by in vivo and in vitro indices of cellular immunity, mammary carcinogenesis appears to be associated with immunogenic changes in the transformed cells and prognostically favorable antitumor cell-mediated immunity in the host. the prognostically favorable cell-mediated immunity appears to be directed against a component(s) which is shared by most stage 0 in situ breast cancers and the major envelope glycoprotein (gp55) of riii murine mammary tumor virus. progressive disease is associat ... | 1979 | 226697 |
| regulation of mouse mammary tumor virus gene expression by glucocorticoid hormones. | several laboratories have documented that glucocorticoid hormones markedly stimulate the expression of mouse mammary tumor virus genes in a variety of mouse mammary tumor cells and in infected heterologous cells. the effect of the hormone appears to be a rapid and specific augmentation of the synthesis of viral rna, mediated by interaction with glucocorticoid receptor proteins. the availability of virus-specific reagents and recent developments in the molecular biology of rna tumor viruses now p ... | 1979 | 226870 |
| in vitro infectivity assay for mouse mammary tumor virus. | studies of mouse mammary tumor virus (mmtv) have been impeded by the lack of an in vitro infectivity assay. we have developed a rapid, quantitative in vitro assay for mmtv infectivity based on the detection of positively staining foci by immunoperoxidase. this assay and a 50% end-point titration of mmtv infectivity gave identical virus titers. infection of a rat hepatoma cell line, a feline kidney cell line, and a normal murine mammary gland cell line by virus from the mouse mammary tumor gr3a c ... | 1979 | 226995 |
| intracytoplasmic type a virus-like particles in angioimmunoblastic lymphadenopathy. | virus-like particles which seemed to be oncogenic have not been observed clinically in human neoplasms. however, we found some virus-like particles in the cytoplasm of a few proliferating cells in the lymph nodes of one patient with angioimmunoblastic lymphadenopathy. these were very similar to intracytoplasmic type a particles seen in the mazon-pfizer monkey virus and a mammary tumor virus in a mouse. | 1979 | 227573 |
| sequence homology of nucleic acids from human breast cancer cells and complementary dna's from murine mammary tumor virus and mason-pfizer monkey virus. | simultaneous presence of murine mammary tumor virus- and mason-pfizer monkey virus-specific sequences has been detected in nucleic acids isolated from some human breast tumors and from mcf-7 cells, a well-characterized human breast cancer cell line. carefully characterized long complementary dna transcripts were used in the molecular hybridization experiments. from the data that are presently available, it would appear that when homology is detected with one of the mammary tumor probes the other ... | 1979 | 227595 |
| regulation of transcription by dna-bound non-histone nuclear proteins. | purified non-histone proteins from mouse mammary cells bind specifically to homologous dna or chromatin. complexes of non-histone protein with dna or chromatin, isolated on agarose columns, were transcribed with both escherichia coli rna polymerase and rna polymerase b from calf thymus. the fact that complexing of dna with non-histone proteins increases transcription by e. coli rna polymerase but not by rna polymerase b suggests different mechanisms of transcription by these two enzymes. similar ... | 1979 | 227684 |
| diversity of mammary tumor viral genes within the genus mus, the species mus musculus, and the strain c3h. | proviral sequences complementary to the c3h mouse mammary tumor virus rna genome are present in the dna of early occurring mammary tumors of c3h/hen mice and are absent from apparently normal c3h/hen tissues; these sequences are non-germ line transmitted in c3h/hen mice and have been termed tumor-associated sequences; (w. drohan et al., j. virol. 21:986-995, 1977). we report here that tumor-associated sequences are present in the dna of spontaneous mammary tumors that occur early in the life of ... | 1979 | 228059 |
| induction of mouse mammary tumor virus rna in mammary tumors of balb/c mice treated with urethane, x-irradiation, and hormones. | the involvement of mouse mammary tumor virus (mtv) in the development of mammary tumors of nonviral etiology in balb/c mice was studied by measuring the levels of mtv rna, mtv dna, and mtv proteins in spontaneously arising and hormonally, chemically, and/or physically induced mammary tumors of balb/c females. the following results were obtained. (i) spontaneous mammary tumors contained very low levels of mtv rna; 4 x 10(-6)% of the the cytoplasmic rna was mtv rna. no mtv proteins could be demons ... | 1979 | 228060 |
| organization of mouse mammary tumor virus-specific dna endogenous to balb/c mice. | we used restriction endonucleases to prepare physical maps of the mouse mammary tumor virus (mmtv)-specific dna endogenous to the balb/c mouse strain. the mapping was facilitated by the dna transfer procedure, using complementary dnas specific for the whole and for the 3' terminus of mmtv rna to detect fragments containing viral sequences. the strategies used for the arrangement of fragments into physical maps included sequential digestions with two or three enzymes; preparative isolation of eco ... | 1979 | 228072 |
| polyprotein precursors to mouse mammary tumor virus proteins. | mouse mammary tumor virus (mmtv) derived from the culture medium of gr cells contained seven proteins, identified as gp55, gp33, p25, pp20, p16, p12, and p10. the major viral phosphoprotein was the 20,000-molecular-weight protein, pp20. immunoprecipitation of cytoplasmic extracts from pulse-labeled gr cells identified three mmtv gag-specific proteins, termed pr78(gag), pr110(gag), and pr180(gag+). these intracellular polyproteins were precipitable from cytoplasmic extracts by antisera to virions ... | 1979 | 228073 |
| hormonal regulation of murine mammary tumor virus rna expression during mammary tumorigenesis in balb/c mice. | the effects of glucocorticoids and prolactin on murine mammary tumor virus (mumtv) rna expression in preneoplastic outgrowth lines and mammary tumors in balb/c mice were investigated. hyperplastic alveolar nodules (han) and a ductal hyperplasia (dh) are induced in virgin balb/c mice by prolonged hormonal stimulation or treatment with 7,12-dimethylbenz(a)anthracene or both. mice bearing han or dh outgrowth lines and mammary tumors that arose from the outgrowth lines were treated with glucocortico ... | 1979 | 228079 |
| mouse mammary tumor virus genome expression in chemical carcinogen-induced mammary tumors in low- and high-tumor-incidence mouse strains. | involvement of mouse mammary tumor virus (mmtv) in 7,12-dimethylbenz[a]anthracene (dmba)-induced mammary tumorigenesis was investigated in low- (balb/c) and high- (balb/cfc3h) mammary-tumor-incidence mouse strains. both strains contain endogenous mmtv integrated into the cellular genome. additionally, balb/cfc3h mice are infected with exogenous mmtv-s which is responsible for a higher incidence of mammary tumors in breeding females. administration of dmba to virgin mice of both strains resulted ... | 1979 | 228289 |
| expression of mumtv antigens in rabbits and rats infected with mumtv. | 1979 | 228486 | |
| [development of a cellular immune response in a highly cancer-susceptible c3h/he strain of mice and its nonfactor substrain c3h/f after the transplantation of a syngeneic mammary gland tumor]. | syngeneic mammary gland tumor (mmt-1) grew slower in non-factor c3h/f (mtv-l) mice than in wirus-positive c3h/he (mtv-s) mice. the immunization of mice with tumor (mmt-1), inoculated and later excised, revealed a higher immune reactivity in the mice of the non-factor substrain. in studying the dynamics of the cytotoxic activity of lymphocytes in regional lymph nodes cytotoxically active lymphocytes were found to appear in c3h/f mice on day 6 after the inoculation of tumor (mmt-1), while the area ... | 1979 | 228516 |
| [effect of succinic acid on spontaneous tumor frequency and longevity in c3h/sn mice]. | 1979 | 228918 | |
| failure to induce protection against transplanted mammary tumours by vaccination with the purified murine mammary tumour virus structural proteins gp52 and p28. | 1979 | 228941 | |
| acceleration of mammary cancer development by grafting of fetal mammary mesenchymes in c3h mice. | transplantation of fetal mammary gland mesenchyme into mammary glands of 2-month-old syngeneic virgin mice resulted in focal re-enactment of events that normally occur probably during fetal and early postnatal development of the mammary gland. portions of the recipient's mammary duct system in contact with the fetal mammary mesenchyme underwent branching and proliferation in a pattern resembling that of rudimentary mammary gland development. this process occurred in c3h mice regardless of whethe ... | 1979 | 229052 |
| aetiology of breast cancer: a brief review. | cancer of the human breast is probably a group of diseases which have different causes. changes in hormonal status that increase breast cancer risk probably do so by 'promoting' tumour development rather than by 'initiating' it. exogenous oestrogens seem to act as tumour promoters in this context, but there is to date no evidence that oral contraceptives, some of which contain oestrogens in low dosage, increase breast cancer risk. on the contrary, they appear to reduce the incidence of benign br ... | 1979 | 229089 |
| conserved region of mammalian retrovirus rna. | the viral rnas of various mammalian retroviruses contain highly conserved sequences close to their 3' ends. this was demonstrated by interviral molecular hybridization between fractionated viral complementary dna (cdna) and rna. cdna near the 3' end (cdna(3')) from a rat virus (rpl strain) was fractionated by size and mixed with mouse virus rna (rauscher leukemia virus). no hybridization occurred with total cdna (cdna(total)), in agreement with previous results, but a cross-reacting sequence was ... | 1979 | 229272 |
| immunologic heterogeneity of tumor cell subpopulations from a single mouse mammary tumor. | five subpopulations (66, 67, 68h, 168, and 4.10lm) obtained from a single balb/cfc3h mammary adenocarcinoma were used to assess intratumor immunologic heterogeneity. balb/c and balb/cfc3h mice were immunized with each of the subpopulations, and lymph node cells (lnc) from immunized animals were tested for cell-mediated immunity (cmi) to each subpopulation in vitro by chromium release and microcytotoxicity tests and in vivo by winn assays. the immunogenic character of the subpopulations differed ... | 1979 | 229294 |
| gene order of mouse mammary tumor virus precusor polyproteins and their interaction leading to the formation of a virus. | 1979 | 229627 | |
| assessment of cellular immune response to cancer of the breast. | cellular immune competence and cell-mediated immunity to tumor antigens have been studied in patients with breast cancer. some patients have been shown to have depressed lymphoproliferative responses to phytohemagglutinin and in mixed leukocyte culture. in some cases, this depression appeared attributable to suppressor cells. many patients with breast cancer had a cellular immunity to extracts of autologous or allogenetic tumors, as detected by lymphoproliferation and leukocyte migration inhibit ... | 1979 | 229763 |
| glucocorticoid regulation of mouse mammary tumor virus gene expression. | glucocorticoid hormones act rapidly and specifically to stimulate the synthesis of mouse mammary tumor virus rna in a variety of mouse mammary tumor cells and infected heterologous cells. the increase in viral rna production appears to be mediated by receptor proteins and requires the presence of basal levels of viral rna. infection of heterologous cells with mmtv may alter host cell responses to glucocorticoids; in addition, production of unintegrated viral dna in these cells has provided reage ... | 1979 | 229906 |
| viral expression and immunogenicity of cba mammary carcinomas and their hybrid lines with an l-cell derivative (a9ht). | 1979 | 230057 | |
| detection of virus antigens in swiss albino mice infected by milk-borne mouse mammary tumour virus: the effect of age, sex and reproductive status. i. localization by immunofluorescence of four antigens in mammary tissues and other organs. | the indirect immunofluorescence technique was used to investigate the expression of virus antigens in a swiss albino mouse strain infected by mouse mammary tumour virus (mmtv). the antisera used were monospecific for: the glycopolypeptides gp160 and gp47, and the internal polypeptides p28 and p8. in mice infected with milk-borne mmtv, all four antigens were detected in the mammary gland during the first pregnancy and then throughout life, and in mammary tumours. antigen gp160, located at the sec ... | 1979 | 230308 |
| detection of virus antigens in swiss albino mice infected by milk-borne mouse mammary tumour virus: the effect of age, sex and reproductive status. ii. radioimmunoassay of two virus components, gp47 and p28 in serum and organ extracts. | extracts of various organs, mammary tumours and sera from milk-borne mmtv infected swiss albino mice of different age, sex and physiological conditions were tested by radioimmunoassay for the presence of gp47, the main envelope polypeptide, and p28, the main core protein of the virus. except in brain, ovaries and testes, both antigens were found in all organs of old animals and of females after the onset of their first pregnancy. antigens were not present in organs of weanlings or in whole foetu ... | 1979 | 230309 |
| conditions for hormone-stimulated expression of endogenous c57bl strain-associated mammary tumor virus genome. | full mmtv-y gene expression can occur in dexamethasone-insulin-prolactin-stimulated cell cultured derived from c57bl/10 mammary adenocarcinomas induced by syncarcinogenic action of chemical carcinogens (dimethylbenzanthracene), and mammotropic hormones (estrogen and prolactin). the rate of the hormone-stimulated virus production, as determined by biochemical, immunological and electron microscopical methods, was comparable to the level of spontaneous mmtv production by cells of established mouse ... | 1979 | 230421 |
| envelope antigens of oncoviruses. | 1979 | 230728 | |
| in vivo and in vitro phosphorylation of murine mammary tumour virus proteins. | a comparative study of in vitro and in vivo phosphorylation of murine mammary tumour virus, a type brna virus, is reported. the protein kinase activity associated with murine mammary tumour virus catalysed the in vitro phosphorylation of endogenous virus polypeptides. this kinase activity required a divalent metal cation, a non-ionic detergent, and was stimulated in the presence of dithiothreitol. exogenous cyclic amp was not required. the 32p-labelled products of the in vitro reaction were comp ... | 1979 | 231088 |
| endogenous mouse mammary tumor virus dna is distributed among multiple mouse chromosomes. | 1979 | 217167 | |
| localization of murine mammary tumor virus polypeptides on the surface of tumor cells. | 1979 | 217688 | |
| specificity of response to viral proteins in horses infected with equine infectious anemia virus. | three structural proteins of equine infectious anemia virus were purified, labeled with 125i, and utilized in radioimmunoassays with horse sera and antisera to heterologous retroviruses. whereas radioimmunoassay titers for the major protein, p25, were 500- to 1,000-fold higher than titers in immunodiffusion, for clinical purposes these two procedures were equivalent. antibodies to two low-molecular-weight proteins, p12 and p10, were also found in infected horses, but with a lower frequency and l ... | 1979 | 217831 |
| integration and transcription of mouse mammary tumor virus dna in rat hepatoma cells. | rat hepatoma cells infected with mouse mammary tumor virus (mmtv) acquire viral dna that becomes covalently linked to the cell dna. using restriction endonucleases and the dna transfer procedure of southern [southern , e.m. (1975) j. mol. biol. 98, 503--517], we have studied the sites in cellular dna into which mmtv dna inserts. these experiments indicate that: (i) there are many sites in cell dna into which mmtv dna integrates; (ii) the junctions between viral and cellular dna occur within a li ... | 1979 | 218215 |
| high incidence of mammary tumors in mice with inherited asplenia carriers for the nude gene. | a colony of mice suffering from dominant hemimelia associated with agenesis of the spleen has been developed and characterized during the past 7 years. the hereditarily asplenic (dh/+) mice have a very low incidence (9%) of spontaneous mammary tumors (smt). asplenic (dh/+) females were mated with mice homozygous (nu/nu) for hereditary athymia (nude) having a balb/c background. balb/c females heterozygous for the nu gene and with spleen (nu/+,+/+) have a moderate incidence (12%) of smt, whereas n ... | 1979 | 218729 |
| murine mammary tumor virus expression during mammary tumorigenesis in balb/c mice. | steady-state levels of murine mammary tumor virus (mumtv) rna were quantitated during mammary tumorigenesis in balb/c mice by molecular hybridization with a representative mumtv complementary dna (cdna) probe. hyperplastic alveolar nodule (han) lines are preneoplastic mammary lesions that were induced in balb/c mice by hormones alone or in combination with 7,12-dimethylbenz(a)anthracene and give rise to mammary tumors. the hormone-induced han lines d1 and d2 contained detectable amounts of hybri ... | 1979 | 219243 |
| autogenous antibodies against the murine mammary tumor virus in strains of mice with low incidences of mammary tumors. | the radioimmunoprecipitation assay for the murine mammary tumor virus (mumtv) was used to detect naturally occurring antibodies against mumtv in 3 groups of highly inbred mouse strains. 1) some strains had high incidences of mammary tumors, such as strains gr and c3h. antibodies against mumtv were detected in the sera of females of these strains at early ages. 2) some mouse strains had low incidences of mammary tumors with an intermediate mumtv expression, such as strains c3hf, riiif, and balb/c ... | 1979 | 219283 |
| [morphogenesis of intracytoplasmic oncornaviruses]. | intracytoplasmic oncorna viruses type-a are de novo formed in the cytoplasma, independently of the organella. in the early phase of the morphologenesis an electrondense patch-like area and the disappearence of the ribosomes can be observed. double-membrane structures consisting of gylcoprotein can be seen in form of segments, horseshoes or rings. in the centre of the viruses ribosoma-like inclusions may be observed. viruses of tubular structure appear to be of peculiar forms of the formation of ... | 1979 | 219328 |
| strain-related variation in the interaction of ferritin-conjugated plant lectins with mouse mammary tumor viruses. | 1979 | 216482 | |
| [direct electron-microscopy virus demonstration in veterinary medicine]. | 1979 | 216536 | |
| molecular relationship of the dna and rna of intracytoplasmic a particles to mouse and mammary tumour virus genomes. | we have directly tested the hypothesis that single-stranded cytoplasmic a particle-associated dna (ss cap dna) is a murine mammary tumour virus (mmtv) proviral intermediate by hybridizing 125i-labelled ss cap dna to mmtv rna or to mmtv complementary dna (cdna). 125i-labelled cap dna did not form duplexes with either mmtv rna or mmtv cdna. in contrast, cap rna hybridized readily with mmtv cdna. cap rna contained all the mmtv virus sequences, but at lower concentrations than in mmtv virus particle ... | 1979 | 232129 |
| impaired maturation of mouse mammary tumor virus precursor polypeptides in lymphoid leukemia cells, producing intracytoplasmic a particles and no extracellular b-type virions. | processing of polypeptides of the mouse mammary tumor virus, a type b retrovirus, was investigated in a transplanted thymic lymphoma cell line of the gr strain (grsl). this cell line was maintained in vivo in ascites form and in vitro as a suspension culture. grsl cells produce clusters of intracytoplasmic a particles and are virtually deficient in the production of mature extracellular b-type particles. as control, a mammary tumor cell line of the same mouse strain capable of complete virion sy ... | 1979 | 232176 |
| [leukemogenic activity of cell-free centrifugates of a transplantable mammary gland adenocarcinoma in cc56br strain mice]. | 1979 | 232258 | |
| bioactivities and the effect of dilution on various milk-borne murine mammary tumor viruses. | infectivity titrations of milk-borne murine mammary tumor virus (mumtv) from different sources or prepared in different ways or stored for periods of time have been compared. titration curves were in general reproducible for mumtvs of different sources or handled in different ways and for different methods of measurement, such as hyperplastic alveolar nodule (han) development, tumor development, or mumtv antigen secretion in third-lactation milk, the curves had characteristic shapes with a low i ... | 1979 | 232494 |
| tumours of the mammary gland. | 1979 | 233006 | |
| virus precursor shedding from mammary tumour cells. | 1979 | 233256 | |
| simultaneous production of casein and mammary tumor virus in mouse mammary epithelial cells grown on floating collagen gels. | simultaneous production of casein and mammary tumor virus (mtv) was analyzed in monolayer cultures of mammary epithelial cells from pregnant balb/cfc3h mice. a comparison of the 2 cell culture substrata, plastic culture dish and floating collagen gel, showed that the latter supported a much higher degree of simultaneous casein and mtv production in the presence of insulin, cortisol and prolactin in serum-free culture medium. importance of floating collagen gel was further shown by delaying the f ... | 1979 | 219954 |
| tumour incidence, growth, reproduction and longevity in female c3h mice fed polyunsaturated ruminant-derived foodstuffs. | earlier studies with the random-bred quackenbush mouse strain showed that human-type diets based on linoleic acid-enriched foodstuffs derived from ruminants fed protected polyunsaturated oils have no detrimental effects on growth, reproduction or longevity. tumour incidence and time of onset of tumour development have now been studied in the inbred, tumour-prone mouse strain c3h, in addition to growth, reproduction and longevity. mice were fed a polyunsaturated human diet, a conventional human d ... | 1979 | 574381 |
| immunologic techniques for the identification of virion 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 permits 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 conjugated and unconjugated markers. hemocyanin (hcy) from whelk, busycon canniculatum, has been ... | 1979 | 392719 |
| 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 |
| serological definition of individually distinct surface antigens in mouse mammary carcinomas. | 1980 | 6164557 | |
| 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 |