Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| ultrastructural comparison of a virus from a rhesus-monkey mammary carcinoma with four oncogenic rna viruses. | the ultrastructure and morphogenesis of mason-pfizer monkey virus, isolated from a mammary carcinoma in a rhesus monkey, was compared with those of murine mammary tumor virus, murine leukemia virus, l1210 leukemia-associated virus, and avian myeloblastosis virus. the simian virus resembled murine mammary tumor virus and the l1210 virus in that it produced intracytoplasmic particles that were enveloped during budding. it resembled l1210 virus and murine leukemia virus in budding with smooth envel ... | 1971 | 4327008 |
| mason-pfizer monkey virus isolated from spontaneous mammary carcinoma of a female monkey. i. detection of virus antigens by immunodiffusion, immunofluorescent, and virus agglutination techniques. | 1971 | 4996663 | |
| serological and structural properties of mason-pfizer monkey virus isolated from the mammary tumor of a rhesus monkey. | we describe here serological and structural properties of a virus, mason-pfizer monkey virus (m-pmv), isolated from a simian mammary tumor. this virus is morphologically similar to the known oncogenic rna viruses (oncornaviruses). it has a 60-70s rna, and its replication is inhibited by actinomycin. antisera prepared against the virus isolated by density-gradient centrifugation identify at least two viral structural antigens. immunodiffusion studies show that this virus is serologically unrelate ... | 1971 | 4997759 |
| chronic poliovirus infection of cocultivated monkey cells harboring the mason-pfizer monkey virus. | 1972 | 4345966 | |
| transformation of rhesus foreskin cells by mason-pfizer monkey virus. | 1972 | 4626796 | |
| morphological and biophysical properties of the mason-pfizer monkey virus. | 1972 | 4631464 | |
| viral and cellular dna polymerase: comparison of activities with synthetic and natural rna templates. | two dna polymerases purified from normal human lymphocytes are distinguishable from the viral reverse transcriptases of avian myeloblastosis virus and mason-pfizer monkey virus by their relative affinity for select templates. in this respect, the activity of the two normal human lymphocyte polymerases closely resembles the activity of escherichia coli dna polymerase 1. the viral and cellular dna polymerases are equally active with the nonspecific template, poly(ra) . poly(dt). criteria for disti ... | 1972 | 4113240 |
| characterization and separation of viral dna polymerase in mouse milk. | two dna polymerase with properties of viral rna-directed dna polymerase can be found in riii mouse milk. one enzyme is the polymerase of type-c viruses; this enzyme prefers manganese to magnesium with poly(ra).oligo(dt) as synthetic template, is inhibited by specific sera, and has an apparent molecular weight of 70,000. milk from balb/c and nih swiss mice contain a vast predominance of this type-c enzyme. the other dna polymerase from riii mouse milk prefers magnesium to manganese, is not inhibi ... | 1973 | 4124683 |
| purification, characterization, and comparison of the dna polymerases from two primate rna tumor viruses. | the dna polymerase from the mason-pfizer monkey virus (m-pmv), an rna tumor virus not typical type-c or type-b, has been purified a thousand-fold over the original crude viral suspension. this purified enzyme is compared to a similarly purified dna polymerase from the primate woolly monkey virus, a type-c virus. the two enzymes have similar template specificities but differ in their requirements for optimum activity. both dna polymerases have a ph optimum of 7.3 in tris buffer. m-pmv enzyme has ... | 1973 | 4127027 |
| mason-pfizer virus characterization: a similar virus in a human amniotic cell line. | mason-pfizer monkey virus (mp-mv) is a rna virus with an rna-instructed dna polymerase first isolated from a rhesus monkey mammary adenocarcinoma in 1970. until recently, there have been no other isolates. a continuous human amnion cell line, ao, was found to be producing a virus indistinguishable or closely related to the mason-pfizer virus as measured by morphological, immunological, and biochemical methods. by thin-section electron microscopy, the extracellular virus particle in ao line is 11 ... | 1973 | 4128382 |
| isolation of a new simian foamy virus from a spider monkey brain culture. | a syncytium-forming (foamy) virus was isolated from a spider monkey brain cell culture. cytopathic effect was observed both in the brain culture and in human embryonic kidney cells. neutralizing antibody was present in the sera of the spider monkey from whom the isolation was made. the virus was inhibited by 5-bromo-2-deoxyuridine (20 mug/ml), contained a ribonucleic acid-dependent deoxyribonucleic acid polymerase, and had an infectivity peak at 1.15 g/cm(3) in a sucrose density gradient. the vi ... | 1973 | 4201323 |
| biologic characteristics of transformed rhesus foreskin cells infected with mason-pfizer monkey virus. | 1974 | 4207874 | |
| occurrence of mason-pfizer monkey virus in healthy rhesus monkeys. | 1974 | 4214612 | |
| sequence homology between the rna of mason-pfizer monkey virus and the rna of human malignant breast tumors. | radioactive dna ([(3)h]cdna) complementary to the rna of mason-pfizer monkey virus was used in molecular hybridization experiments to demonstrate sequence homology between its viral rna and rna of human malignant breast tumors. hybridization products were analyzed by cesium sulfate equilibrium density centrifugation and hydroxylapatite chromatography. seven of ten human malignant breast tumors tested contained virus-related rna when assayed by hydroxylapatite chromatography, whereas no sequence ... | 1974 | 4216026 |
| hela-like marker chromosomes and type-a variant glucose-6-phosphate dehydrogenase isoenzyme in human cell cultures producing mason-pfizer monkey virus-like particles. | 1974 | 4472134 | |
| evidence for allosterism in in vitro dna synthesis on rna templates. | hemoglobin mrna and (ra)(n).(dt)(10) have been used as primer-templates in a kinetic study of dna synthesis with escherichia coli dna polymerase i (dna nucleotidyl transferase, ec 2.7.7.7) and mason-pfizer monkey virus reverse transcriptase (rna-directed dna polymerase). the rate versus enzyme concentration curve is sigmoidal and is consistent with a cooperative phenomenon. the results could be interpreted in terms of the formation of an active complex containing enzyme dimers (or oligomers) on ... | 1974 | 4132534 |
| serological analysis of reverse transcriptase of the mason-pfizer monkey virus. | 1974 | 4133137 | |
| immunological properties of two polypeptides of mason-pfizer monkey virus. | two polypeptides were isolated from the mason-pfizer monkey virus (mp-mv). the polypeptides, designated mp-mv p26 and mp-mv p15, were 26,000 and 15,000 molecular weight, respectively, based on gel filtration chromatography in the presence of 6 m guanidine hydrochloride. radioimmunoassays developed for mp-mv p26 and p15 were, respectively, 10 and 100 times more sensitive than immunodiffusion and 1 and 10 times more sensitive than micro-complement fixation for the detection of mp-mv. antigens of o ... | 1974 | 4134467 |
| plaque assay for the mason-pfizer monkey virus. | 1974 | 4135599 | |
| systematics of rna tumor viruses and virus-like particles of human origin. | [(3)h]dna copies of avian, feline, murine, and primate rna tumor virus genomes were synthesized in vitro by an rna-dependent dna polymerase reaction. these dnas were hybridized to 60-70s rna that had been purified from the viruses. the amount of the [(3)h]dna hybridized yielded a measure of the genetic relatedness among the dna preparations synthesized by the viruses. when many combinations of dna and rna were analyzed, the pattern of hybridization showed in some cases that the dna copies of the ... | 1974 | 4137960 |
| competition radioimmunoassay for mason-pfizer monkey virus: comparison with recent isolates. | the major core protein of mason-pfizer monkey virus was purified by deae ion exchange column chromatography and shown to be 27,000 daltons (p27). following the characterization of monospecific antisera prepared against p27, a radioimmunoassay was developed with these reagents and competition experiments were done with come of the recent m-pmy-like isolates as well as with other oncornaviruses. results suggest that three of the viruses tested, ao, x-381 and ftp-1, are similar to m-pmv while j-96 ... | 1975 | 49328 |
| biochemical properties of the bromodeoxyuridine-induced guinea pig virus. | the biophysical and biochemical properties of the virus particles released by guinea pig embryo cells treated with 5-bromo-2'-deoxyuridine (budr) have been compared to those of the b-type mouse mammary tumor virus (mmtv) and the c-type rauscher murine leukemia virus. the high-molecular-weight (60 to 70s) rna of the budr-induced guinea pig virus (gpv) has a molecular weight of 8 x 106 when measred by mixed agarose polyacylamide gel electrophoresis. the virus particles isolated from the tissue cul ... | 1975 | 51933 |
| transcription of 70s rna by dna polymerases from mammalian rna viruses. | dna polymerases purified by the same procedure from four mammalian rna viruses, simian sarcoma virus type 1, gibbon ape lymphoma virus, mason-pfizer monkey virus, and rauscher murine leukemia virus are capable of transcribing heteropolymeric regions of viral 70s rna without any other primer. in this reconstituted system the enzymes from simian sarcoma virus type 1, mason-pfizer monkey virus, and rauscher murine leukemia virus transcribe viral 70s rna almost as efficiently as the dna polymerase f ... | 1975 | 53295 |
| serological analysis of an oncornavirus (pmf virus) detected in malignant permanent human cell lines. | immunodiffusion analysis of the pmf virus which was detected in malignant permanent human cell lines revealed positive reactions with antisera against the mason-pfizer monkey virus (mpmv). no cross-reactivity was demonstrated with murine leukemia virus (mulv), rat leukemia virus (ralv), hamster leukemia virus (halv), feline leukemia virus (felv), simian (woolly monkey) sarcoma virus (ssv-1) and mouse mammary tumor virus (mtv). the cross-reactive antigens of the pmf virus and the mpmv are conside ... | 1975 | 171892 |
| rna subunit structure of mason-pfizer monkey virus. | mason-pfizer monkey virus 60-70s rna has a molecular weight of 8 times 10-6 when analyzed on polyacrylamide gels. dissociation of 60-70s rna of mason-pfizer monkey virus and murine leukemia virus by heat or formamide (40%) resulted in conversion to identical subunit structures of 2.8 times 10-6 daltons; treatment with lower amounts of formamide revealed a partial dissociation of mason-pfizer monkey virus 60-70s rna released three low-molecular-weight rna species of 10-5, 3,5 times 10-4, and 2.5 ... | 1975 | 803570 |
| responses of infant rhesus monkeys to inoculation with mason-pfizer monkey virus materials. | rhesus monkeys neonatally inoculated with mason-pfizer monkey virus (m-pmv) and virus-infected cells frequently developed viral and/or bacterial pneumonia and enteritis. three characteristic hematologic patterns occurred among the inoculated animals and correlated well with the probability of survival. postmortem examination of the animals revealed lymphadenopathy and thymic atrophy. m-pmv was present in lymph nodes, blood, brain, spleen, thymus, kidneys, and bone marrow. the disease induced in ... | 1975 | 804565 |
| mason-pfizer monkey virus: analysis and localization of virion proteins and glycoproteins. | the polypeptide composition of mason-pfizer monkey virus was determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. six major polypeptides of molecular weights 68,000, 27,000, 20,000, 14,000, 12,000, and 10,000 were resolved regardless of the cell type (i.e., two human and two rhesus) in which the virus was grown. protein gp68 (68,000) represented the major virus glycoprotein and protein gp20 (20,000) represented a minor glycoprotein of the virion, again regardless of the ce ... | 1975 | 810603 |
| immunological relationship between an oncornavirus isolate from hep-2 cells, mason-pfizer monkey virus, and human tumor cells. | 1975 | 822825 | |
| [detection of the gs-antigen of d-type virus in the cells of human breast fibroadenoma]. | gs-antigen(s) of the d-type virus isolated from the continuous cells of human carcinoma was detected by the immunodiffusion with an indirect radioimmunoautographic assay in 5 of 7 human breast fibroadenoma. this virus contained gs-antigen common with the mpmv. these data demonstrated the genom of the d-type virus (or of a similar virus) to be integrated with the human fibroadenoma cells genom. expression of the virus genom takes place at least to the level of the virus gs-antigen synthesis. the ... | 1976 | 829403 |
| [human d(b) type virus: comparison of d(b) type virus antigens with antigens of oncornaviruses of different origins]. | it was found by the immunodiffusion test that the d(b) type virus isolated from human cell lines and mason-pfizer monkey virus (m--pmv) contained common group-specific antigen(s). no cross-reaction was demonstrated between this d(b) type virus and c type oncornaviruses of various origins. | 1976 | 816086 |
| antigenic analysis of the major structural protein of the mason-pfizer monkey virus. | the major internal protein, p27 (m.w. 27,000 daltons) of the mason-pfizer monkey virus (mpmv) was purified by gel filtration and ion-exchange chromatography and then used to develop a radioimmunoassay (ria). this ria was specific for mpmv because no immunologic cross-reactivity was observed between p27 of mpmv and 13 different rna tumor viruses of mammalian and avian origin. however, the p27 of mpmv grown in three different primate cells exhibited identical antigenic cross-reactivity. in additio ... | 1976 | 819581 |
| sialylatin of glycoproteins of murine mammary tumor virus, murine leukemia virus, and mason-pfizer monkey virus. | neuraminidase treatment of mouse mammary tumor virus, rauscher murine leukemia virus, and mason-pfizer monkey virus resulted in loss of their capacity to inhibit hemagglutination of influenza virus. hemagglutination-inhibition activity of these rna tumor viruses could be restored by in vitro resialylation catalyzed by sialyl transferase. the major glycoprotein in the intact envelope of desialylated and, to some extent, native virions could be specificallly labeled in vitro with cmp-(14c) sialic ... | 1976 | 178911 |
| immunological cross reactivity of mason-pfizer monkey virus with type c rna viruses endogenous to primates. | 1976 | 180419 | |
| cellular hypersensitivity of gp55 of riii-murine mammary tumor virus and gp55-like protein of human breast cancers. | previous studies suggested that immunogenic breast cancer tissues contained a component(s) that is antigenically similar to some component of murine mammary tumor virus (mumtv) and resembles the glycoprotein, m.w. 55,000 (gp55), of riii-mumtv in molecular weight and charge density. this investigation measured in vitro cellular hypersensitivity responses of breast cancer patients to riii mouse milk, purified riii-gp55, c3h-mumtv, autologous and homologous breast cancer tissues, gp50 of a-mumtv, a ... | 1976 | 184925 |
| oncornavirus-like particles in baboon type c virus-infected chimpanzee lung cells (sfre:cl-1). | intracytoplasmic type a particles were observed in a fetal chimpanzee lung culture (sfre:cl-1) inoculated with type c virus-containing supernatants from a coculture of baboon placenta and sfre:cl-1 cells. budding, immature, and mature type c particles were also noted. in thin section, spike-like structures were rarely detected on budding intracytoplasmic type a particles but were occasionally observed on some immature and mature virus particles. unlike mouse mammary tumor virus or mason-pfizer m ... | 1976 | 186614 |
| detection of simian type-c particles in mason-pfizer virus infected cultures. | a simian type-c virus has been detected in cultures chronically infected with mason-pfizer monkey virus (m-pmv). simultaneous budding of m-pmv and type-c virus particles from the same cells was observed in cultures incubated at 37 or 40 degrees c. however, the frequency of such cells was greater in cultures grown at 40 degrees c. although clusters of type-c viral buds were seen at the surface of the cells, extracellular mature type-c particles in cell pellets or concentrated virus preparations w ... | 1976 | 54406 |
| relationship between the mason-pfizer monkey virus and hela virus: immunoelectron microscopy. | envelope antigens of the mason-pfizer monkey virus (mpmv) and the morphologically similar hela virus, which is continuously produced in some hela cell lines, were compared by indirect immunoferritin techniques. antisera raised against mpmv and hela virus revealed cross-reacting antigenic specificities on the surfaces of both agents, and cross-absorption and end-point dilution techniques indicated the presence of identical envelope antigens. the results demonstrated a close relationship, if not a ... | 1976 | 56448 |
| isolation and characterization of an antigen of the bovine c-type virus. | by means of gel filtration and isoelectric focusing, an antigen of the bovine c-type leukemia virus was isolated in a highly purified form from extracts of infected cells. the antigen has a molecular weight of approximately 25,000 daltons and an isoelectric point of 6.4 to 6.6. in immunodiffusion experiments, the antigen forms a line of identity with an antigen extracted from highly purified bovine c-type leukemia virus by treatment with ether or triton x-100. as determined by immunodiffusion an ... | 1976 | 56993 |
| bovine leukemia virus: an exogenous rna oncogenic virus. | short-term cultures of bovine leukemic lymphocytes release virus particles with biochemical properties of rna oncogenic viruses. these particles, tentatively called bovine leukemia virus (blv), have a high molecular weight rna-reverse transcriptase complex and a density of 1.155 g/ml in sucrose solutions. molecular hybridizations between blv/[3h]cdna and several viral rnas show that blv is not related to mason-pfizer monkey virus, simian sarcoma associated virus, feline leukemia virus, or avian ... | 1976 | 57616 |
| equine infectious anemia virus: evidence favoring classification as a retravirus. | equine infectious anemia virus (eiav) has a density of 1.154 g/cm3 in sucrose a high-molecular-weight rna similar in size to rauscher murine leukemia virus, and an internal virion reverse transcriptase that utilizes the synthetic rna template poly(ra) but not the synthetic dna template poly(da), both with (dt)12 as primer. although capable of utilizing manganese at low concentrations (approximately 0.1 mm), eiav reverse transcriptase showed highest activity in the presence of 9 mm magnesium. the ... | 1976 | 61283 |
| a new class of genetically transmitted retravirus isolated from mus cervicolor. | the cocultivation of spleen cells from the southeast asian mouse, mus cervicolor, with heterologous cell lines has permitted the isolation of a new retravirus (designated m432) that can be transmitted to tissue culture cells of the laboratory mouse, m. musculus. cells infected with m432 contain cytoplasmic type a particles and budding forms with compact,spherical nucleoids; extracellular virions lack surface spikes and have a condensed, central core surrounded by an intermediate line. like other ... | 1976 | 62362 |
| detection, quantitation, and characterization of the major internal virion antigen of the bovine leukemia virus by radioimmunoassay. | the major internal polypeptide of the bovine leukemia virus (blv) was purified to homogeneity with the use of gel filtration and affinity chromatography. like previous results, the protein had a molecular weight of 25,000 daltons as determined by electrophoresis in polyacrylamide gels with sodium dodecyl sulfate. more than 90% of the 125i-labeled protein was precipitated by bovine sera that reacted in immunofluorescence tests with acetone-fixed blv-infected cells. in contrast, minimal precipitat ... | 1976 | 63563 |
| bovine leukemia virus: an exogenous rna oncogenic virus? | short term cultures of bovine leukemic lymphocytes release virus particles with biochemical properties of rna oncogenic viruses. these particles, tentatively called bovine leukemia virus (blv) have a high molecular weight-reverse transcriptase complex and a density averaging 1.155 g/ml in sucrose solutions. molecular hybridizations between blv-3h cdna and several viral rnas show that blv is not related to mason-pfizer monkey virus (mpmv) simian sarcoma associated virus (ssv-1) feline leukemia vi ... | 1976 | 64382 |
| expression of mason-pfizer and simian type c viruses in the presence of 5-iododeoxyuridine and dexamethasone. | production of infectious mason-pfizer monkey virus (m-pmv) was enhanced after treatment of the cmmt cell line with 2.5 x 10(-5) m dexamethasone phosphate (dxm). the reverse transcriptase (rt) activity and infectivity titers of treated culture fluids were enhanced by five- and tenfold, respectively. along with stimulation of m-pmv synthesis, a simian type c virus (scv) was also detected by electron microscopic and rt analyses. the scv was serologically related to the endogenous baboon type c viru ... | 1977 | 67214 |
| antigenic relatedness of the dna polymerase of human breast cancer particles to the enzyme of the mason-pfizer monkey virus. | we have previously reported [(ohno, t., sweet, r.w., hu, r., dejak, d. & spiegelman, s. (1977) proc. natl. acad. sci. usa 74, 764-768)] on the purification and characterization of the dna polymerase from human breast cancer particles. its preference for certain synthetic templates and its ability to use a viral rna to fashion a faithful dna transcript identify it as a reverse transcriptase similar to that found in the mouse mammary tumor virus and in the mason-pfizer monkey virus (mpmv). we repo ... | 1977 | 68475 |
| characterization of a retravirus isolated from squirrel monkeys. | a new retravirus (smrv) isolated from a squirrel monkey, saimiri sciureus, has an mg2+-dependen reverse transcriptase and a buoyant density of 1.17 g/cm3 in sucrose and 1.21 g/cm3 in cesium chloride, similar to the mouse mammary tumor virus and the mason-pfizer monkey virus. the polypeptide patter of smrv as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was distinct from the reported polypeptide patterns of known retraviruses. four major polypeptides of molecular weight ... | 1977 | 69728 |
| production of antiserum to the reverse transcriptase of mason-pfizer monkey virus. | the reverse transcriptase of mason-pfizer monkey virus (m-pmv) has been isolated and partially purified by ion exchange chromatography. sera from rabbits immunized with the partially purified enzyme have been shown by microimmunodiffusion analysis to be immunologically specific for the m-pmv polymerase. the immune serum also specifically inhibits m-pmv polymerase activity and this inhibitory activity has been shown to reside in the igg fraction of the serum. the application of these reagents to ... | 1977 | 70506 |
| endogenous new world primate retrovirus: interspecies antigenic determinants shared with the major structural protein of type-d rna viruses of old world monkeys. | a reverse transcriptase-containing virus has recently been isolated from a squirrel monkey (saimiri sciureus). molecular hybridization studies demonstrate that the squirrel monkey retrovirus (smrv) is endogenous to this new world primate, yet lacks detectable nucleotide sequence homology with cellular dnas of representative old world primates or with the genomes of previously isolated old world primate retroviruses. the 35,000-dalton major structural protein (p35) of smrv was purified and shown ... | 1977 | 74833 |
| oncornavirus: isolation from a squirrel monkey (saimiri sciureus) lung culture. | an oncornavirus isolated from a squirrel monkey (saimiri sciureus) lung culture has a density of 1.16 to 1.17 grams per milliliter, contains 70s rna, and has an rna-directed dna polymerase that prefers mg2+ over mn2+ in an assay in which polyribocytidylate - oligodeoxyguanylate (12-18) is used as a synthetic template. morphologically, the virus resembles mason-pfizer monkey virus but is antigenically distinct from this virus. the virus grows in cells of human, chimpanzee, rhesus monkey, canine, ... | 1977 | 63993 |
| interspecies radioimmunoassay for the major structural proteins of primate type-d retroviruses. | a competition radioimmunoassay has been developed in which type-d retroviruses from three primate species compete. the assay utilizes the major structural protein (36,000 daltons) of the endogenous squirrel monkey retrovirus and antisera directed against the major structural protein (27,000 daltons) of the mason-pfizer monkey virus isolated from rhesus monkeys. purified preparations of both viruses grown in heterologous cells, as well as extracts of heterologous cells infected with squirrel monk ... | 1977 | 202962 |
| radioimmunoassay for the major structural protein of mason-pfizer monkey virus: attempts to detect the presence of antigen or antibody in humans. | the 25,000 dalton protein of mason-pfizer monkey virus (mpmv) was isolated by gel filtration chromatography. in agreement with results from other laboratories, antisera to type-c and the non-type-c bovine leukemia and equine infectious anemia viruses did not precipitate 125i-labelled mpmv p25. in addition, these viruses did not cross-react in a competition radioimmunoassay for mpmv p25. twenty-one human tissues (15 breast carcinomas, 2 normal breasts, 3 acute myelogenous leukemias and 1 sarcoma) ... | 1977 | 403148 |
| oncornavirus-like particles in squirrel monkey (saimiri sciureus) placenta and placenta culture. | oncornavirus-like particles similar in morphology to type d particles were observed in 1 of 2 squirrel monkey (saimiri sciureus) placentas. intracytoplasmic type a particles, immature virus particles, and mature viruses with eccentric or occasionally centric nucleoids were associated with placental syncytiotrophoblasts. a spike layer typical of type b viruses was not detected in viral envelopes. onvornaviruses, identical to those previously isolated from squirrel monkey tissues and similar to ma ... | 1977 | 408507 |
| [differentiation of type d virus from continuous human cells (il'in-bykovskiĭ virus) and mason-pfizer monkey virus by the antigens of the viral envelopes]. | for differentiation of ilvin-bykovsky virus (ibv) and monkey meson-pfeizer virus (m-pmv) the method of virus neutralization with antibodies against the envelope virus antigen was used. the viruses were cultivated in similar human embryo cells. the results of the virus neutralization were determined by presence or absence of the gs-antigen in the infected cells. the antiserum to m-pmv envelope antigens did not neutralize the ibv antigen. it has been concluded that ibv and m-pmv differ by their en ... | 1977 | 409444 |
| purification and characterization of the dna polymerase of human breast cancer particles. | previous studies have identified human breast tumor particles possessing many of the features characteristic of rna tumor viruses. in addition to the expected size (600 s) and density (1.16 g/ml) these include possession of an outer membrane and an inner one surrounding a "core" containing a dna polymerase and a large-molecular-weight (70s) rna possessing detectable homology to the rnas of the mouse mammary tumor virus (mmtv) and of the mason-pfizer monkey virus (mpmv). we report here the purifi ... | 1977 | 265540 |
| cross-reaction between antigens of human myelogenous leukemia and mason-pfizer monkey virus. | 1977 | 271610 | |
| studies on human kc cell syncytia formation induced by mason-pfizer monkey virus. | human kc cell monolayer inoculated with concentraten mason-pfizer monkey virus (mpmv) showed syncytia formation within an hour. the cell fusion was blocked by the treatment of the mpmv with neutralizing antiserum. treatment of the mpvm with beta-propiolactone resulted in the loss of infectivity although kc cell fusion ability of the virus still remained. kc cells inoculated with unconcentrated mpmv showed no cell fusion even after several transfers, although a chronic mpmv infection was establis ... | 1977 | 145160 |
| evolution of primate oncornaviruses: an endogenous virus from langurs (presbytis spp.) with related virogene sequences in other old world monkeys. | gene sequences related to a retrovirus (oncornavirus type d) isolated from a lung cell culture from spectacled langur (presbytis obscurus) are found in multiple copies (20-40 per haploid genome) in langur cellular dna; partially homologous virogene sequences are present in the dna of related old world monkey species. primates thus contain gene sequences for at least two distinct classes of genetically transmitted oncornaviruses, the type c class (isolated from baboons) and the type d class descr ... | 1977 | 16592456 |
| demonstration of rna-dependent dna polymerase activity in non-disrupted type d-retravirus particles after treatment with edta. | the type d-retraviruses pmf virus (pmfv) and mason-pfizer moneky virus (mpmv) show rna-dependent dna polymerase (revertase) activity after treatment of the nondisrupted virions with the chelating agent ethylenediaminetetraacetate (edta). in the range of 1 to 5 mm, the effect is dependent on the concentration of edta. as compared with nonidet p40 disrupted particles treatment of pmfv with edta results in a revertase activity of about 65%. simultaneous addition of mg- or ca-ions prevents the edta ... | 1977 | 78610 |
| squirrel monkey retrovirus: electron microscopy of a virus from new world monkeys and comparison with mason-pfizer monkey virus. | the ultrastructural morphogenesis of squirrel monkey retrovirus (smrv) and mason-pfizer monkey virus (mpmv) growth in cell culture were compared. both viruses develop by a process that begins with the formation of intracytoplasmic a particles which are then enveloped at the plasma membrane during budding. smrv also develops as a crescent-shaped nucleoid beneath a bulging plasma membrane, a development characteristic of type c oncornaviruses. free extra-cellular mature smrv was generally round wi ... | 1978 | 417701 |
| cell-mediated immune response to simian oncornavirus antigens in pregnant women. | tritiated thymidine incorporation into lymphocytes of 118 adult women was studied in the presence of mitomycin c-treated cells prepared from cell lines continuously producing mason-pfizer monkey virus (mpmv), baboon c-particle virus, or simian sarcoma virus (ssv) and in the presence of control cell lines documented for the absence of oncornaviruses. at the end of pregnancy, women who had 5-9 pregnancies showed a high frequency (53%) of specific positive responses to cells with mpmv antigens. the ... | 1978 | 203708 |
| detection in human breast carcinomas of an antigen immunologically related to a group-specific antigen of mouse mammary tumor virus. | an antigen immunologically related to a group-specific antigen (gp52, a 52,000-dalton glycoprotein) of the mouse mammary tumor virus has been identified in paraffin sections of human breast cancers by means of the indirect immunoperoxidase technique. the specificity of the reaction with antibody against mouse mammary tumor virus was examined by absorption of the igg with the following: (a) purified gp52; (b) a number of virus preparations (mouse mammary tumor virus, rauscher leukemia virus, simi ... | 1978 | 206905 |
| detection of mason-pfizer monkey virus infection by syncytia formation of human cells doubly transformed by rous sarcoma virus and simian virus 40. | human cells doubly transformed by rous sarcoma virus and sv40 (rsb cells) formed syncytia by cocultivation with mason-pfizer monkey virus (mpmv)-producing cells. this cell fusion was blocked by anti-mpmv serum indicating that the phenomenon is mpmv specific. the rsb cells were successfully used for mpmv infectivity assay in the same manner as kc cells. | 1978 | 208492 |
| spontaneous esophageal carcinoma and epithelial cell line of an adult rhesus monkey. | a continuous epithelial cell line, 816a, was established from a lymph node of an adult rhesus monkey with metastatic esophageal carcinoma. these cells are characterized by the presence of desmosomes and a markedly heteroploid karyotype. at a relatively early culture age, electron microscopy showed both budding and extracellular type c virus. antigen reactive with antisera to mason-pfizer monkey virus was observed by complement-fixation. the level of this antigen decreased with increased culture ... | 1978 | 210934 |
| the use of trypan blue for counterstaining in the sepharose bead immunofluorescence test. the application of the test for the demonstration of primate retrovirus-specific antibodies and antigens. | the sepharose bead immunoflurorescence test was performed by counterstaining the beads with trypan blue. this results in a red staining of negative beads which allows an easy distinction from positive green-fluorescent beads. sepharose beads conjugated with viral proteins or antiviral antibodies were used to demonstrate mason-pfizer monkey virus (mpmw)- and simian sarcoma virus (ssv) - specific antigens or antibodies. the test shows a high sensitivity and specificity and needs a small amount of ... | 1978 | 86253 |
| susceptibility of human cultured cells to mason-pfizer monkey virus. | mason-pfizer monkey virus (m-pmv), originally isolated from mammary carcinoma of a rhesus monkey, is infectious to various human cells in tissue culture. human epithelioid cells (hela and hep-2), fibroblastic cells (embryonic cells as well as virus-transformed embryonic rsb cells), and glial cells (kc) have all been infected with m-pmv. electron microscope studies have shown that all infected cells produce progeny virus. the titer of infectious m-pmv in cultures of hela and hep-2 cells assayed b ... | 1978 | 97115 |
| natural distribution of squirrel monkey retrovirus proviral sequences in primate dnas. | 3h-labelled 70s rna of squirrel monkey retrovirus (smrv) hybridized to a high degree (greater than 52%) to the dna of various tissues of two squirrel monkeys. hybridization of the same probe to dnas of other primates including new world monkeys (woolly monkey, capuchin, owl monkey), old world monkeys (rhesus, african green), apes (gibbon, chimpanzee), and human (a204 cells infected with mpmv) revealed no significant hybridization. analysis of the kinetics of hybridization indicated that smrv pro ... | 1978 | 99487 |
| primate retroviruses: immunological cross-reactivity between major structural proteins of new and old world primate virus isolates. | the major 35,000-molecular-weight internal antigen (p35) of the squirrel monkey retrovirus (smrv) was isolated and partially characterized. immunological analysis of smrv p35 led to the demonstration of antigenic determinants common to smrv and the mason-pfizer monkey virus (mpmv). a broadly reactive competition immunoassay was developed utilizing antiserum to mpmv to precipitate 125i-labeled smrv p35. although the major structural proteins of mpmv and smrv competed with equal efficiency in this ... | 1978 | 76686 |
| primate retroviruses: envelope glycoproteins of endogenous type c and type d viruses possess common interspecies antigenic determinants. | the major 70,000- to 80,000-molecular-weight envelope glycoproteins of the squirrel monkey retrovirus, mason-pfizer monkey virus, and m7 baboon virus and the related endogenous feline virus, rd114, were isolated and immunologically characterized. immunoprecipitation and competition immunoassay analysis revealed these viral envelope glycoproteins to possess several distinct classes of immunological determinants. these include species-specific determinants, group-specific antigenic determinants un ... | 1978 | 77909 |
| type d retroviruses: occurrence of natural antibodies to mason-pfizer monkey virus in rhesus monkeys. | 1978 | 78569 | |
| [chronic infection caused by the simian mason-pfizer virus in primate cell cultures]. | cell cultures of monkey prepuce (rhfs) and african green monkey kidney (bsc-1) were infected once with simian mason-pfizer virus (mpv) and virus expression in the course of establishment of chronic infection was studied. the productive infection was characterized by changes in the cell metabolism (dna synthesis increased 2-3-fold as early as the "zero" passage), the appearance of gs-antigen, formation of virions of type d and high activity of rna-dependent dna-polymerase. multinuclear giant cell ... | 1978 | 78587 |
| template-specific requirements for dna synthesis by the mason-pfizer monkey virus dna polymerase: unique aspects. | the biochemical properties of dna polymerase purified from mason-pfizer monkey virus were studied, with respect to synthetic and natural template-primer utilization. thes studies revealed the following new information about the mason-pfizer monkey virus enzyme: (a) mason-pfizer monkey virus polymerase was found to prefer template: primer molar nucleotide ratios of 2.5-5: 1 for optimal rates of synthesis with poly(c) .(dg)12-18 as template-primer. (b) poly(a)-directed synthesis was stimulated b ... | 1978 | 78724 |
| comparative large-scale propagation of retroviruses from old world (mason-pfizer monkey virus) and new world (squirrel monkey virus) primates. | a cell culture method is described for the large-scale (50 to 150 1) production of mason-pfizer monkey virus and squirrel monkey virus, two primate retroviruses. virus production was achieved with suspension cultures of chronically infected a204 human rhabdomyosarcoma cells harvested and clarified in the logarithmic stages of cell culture growth. methods for the subsequent purification and concentration of virus material utilizing zonal centrifugation also are described. applications of these me ... | 1978 | 78888 |
| comparison of mason-pfizer monkey virus and squirrel monkey (saimiri sciureus) retrovirus by immunoelectron microscopy. | comparison of mason-pfizer monkey virus and squirrel monkey retrovirus (both candidate type d oncornaviruses) by immunoelectron microscopy revealed that these two viruses do not share common surface antigens. | 1978 | 79657 |
| type d primate retroviruses: a review. | the prototype virus of the type d retroviruses is the mason-pfizer monkey virus (mpmv). mpmv was originally isolated from a breast carcinoma of a female rhesus monkey (an old world monkey). mpmv is of obvious importance in that it is the only retrovirus thus far isolated from a mammary tumor of a primate and has been shown to have transforming potential for primate cells in vitro. subsequent to the isolation of mpmv viruses morphologically and immunologically indistinguishable from mpmv have bee ... | 1978 | 80259 |
| serological definition of the lentivirus group of retroviruses. | the major polypeptides of visna viruses and other lentiviruses have been isolated and shown to be closely related if not identical in radioimmunoassays. by this criterion the lentiviruses form a distinct group of retroviruses unrelated to spuma viruses, mammalian and avian retroviruses that cause tumors, and unclassified retroviruses of cattle and horses. two sera obtained from goats immunized with mason-pfizer monkey virus or squirrel monkey virus reacted with visna p30. additional data suggest ... | 1979 | 85722 |
| the characterization of mason-pfizer monkey virus-induced cell fusion. | 1979 | 111409 | |
| characterization of infection and replication of mason-pfizer monkey virus in human cell cultures. | human cells derived from both normal and neoplastic tissues can be infected by mason-pfizer monkey virus (mpmv) without accompanying cytopathology. infection of cell cultures such as human rhabdomyosarcoma (a204) results in a persistenly infected cell line which can be subcultured over 30 sequential culture passages without significant change in phenotype properties according to reverse, transcriptase (rt), mpmv p27 antigen content, virus particle count and infectivity titre. productive virus in ... | 1979 | 118235 |
| 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 |
| apparent allosterism by avian myeloblastosis virus reverse transcriptase and e. coli dna polymerase i. | a recent report (1) presented evidence for allosterism in reverse transcription by mason-pfizer monkey virus reverse transcriptase and by e. coli dna polymerase i. our experiments also demonstrate these apparent cooperative effects when synthesis is catalyzed by either avian myeloblastosis virus dna polymerase, feline sarcoma virus dna polymerase, or e. coli dna polymerase i (large fragment). we show that the apparent cooperativity depends on the use of oligo(dt)12-18 as primer. however, if the ... | 1979 | 86985 |
| 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 |
| 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 |
| 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 |
| 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 |
| the leukocyte migration inhibition response to certain breast cancer-related antigens (mcf-7 and mumtv): their potential as discriminants. | certain oncogenic viruses have been implicated in human breast cancer, including the murine mammary tumor virus (mumtv) and the mason-pfizer monkey virus (mpmv). we have used the leukocyte migration inhibition (lmi) response to assay the response to several potential breast cancer-related antigens, including mumtv, mpmv, and a breast cancer cultured cell line, mcf-7, in 96 breast cancer patients, in 32 women with benign breast disease, and in 67 normal women. the lowest tenth percentile of contr ... | 1979 | 462374 |
| serological evidence for antigenic differences between the mason-pfizer monkey virus (mpmv) and an mpmv-like virus (pmfv) detected in a malignant permanent human cell line. | 1979 | 369867 | |
| [detection of a common antigenic determinant in the major inner protein of unrelated oncoviruses]. | a new heterologous system of radioimmunoassay (p24 of bovine leukemia virus--antiserum to rous sarcoma virus) has been developed which demonstrated for the first time the existence of a common antigenic determinant in the major inner protein of unrelated oncoviruses: avian leukemia-sarcoma virus, bovine leukemia virus, mammalian type c viruses (mouse, hamster, monkey) and type d viruses (simian mason-pfizer virus). these data suggest a common origin of unrelated oncoviruses and open new approach ... | 1980 | 6155738 |
| inhibition of mason-pfizer monkey virus-induced syncytium formation in normal human cells by homologous interferon. | 1980 | 6156543 | |
| interrelationship of reverse transcriptases of primate type d retroviruses. | enzyme neutralization experiments by using an antiserum to reverse transcriptase (rt) of mason-pfizer monkey virus (mpmv) demonstrated the presence of common antigenic determinants on the rts of all known type d retroviruses and of determinants discriminating different isolates. the rt of mpmv is antigenically closely related to the rts of type d viruses isolated from human cell lines although significant differences are also detectable. it shows a lesser degree of relationship to the rts of squ ... | 1980 | 6159867 |
| common antigenic determinants on structural proteins p10--12 of pmfv and mpmv type d retroviruses. | pmfv, a type d retrovirus isolated from a malignant human embryo cell line, was compared with mason-pfizer monkey virus (mpmv) in a sensitive tannic acid enhanced indirect immunodiffusion test. in addition to the previously shown common antigens, both viruses contain identical group-specific antigenic determinants on their p 10--12 as demonstrated with a specific p 10--12 mpmv test system. interspecies mammalian type c virus antigens were not detected in highly concentrated pmfv preparations. | 1980 | 6161313 |
| 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 |
| differential association of transfer rnas with the genomes of murine, feline and primate retroviruses. | the trnas that are bound to the genomic rnas of several murine, feline, and primate retroviruses have been identified. transfer rnas were divided into those loosely bound and those tightly bound by stepwise thermal dissociation of the 70 s rna. they were then identified and semiquantitated by aminoacylation. proline trna is the most tenaciously bound trna in several strains of murine leukemia virus, two strains of feline leukemia virus, and the primate viruses simian sarcoma, baboon endogenous, ... | 1980 | 6248115 |
| fusion of transformed human cells by simian retroviruses. | mason-pfizer monkey virus (mpmv), baboon endogenous virus (baev) and simian sarcoma virus associated virus (ssav) induced fusion in cultured human cells derived from tumors or transformed in vitro. not only virus-transformed cells, but also cells transformed spontaneously by 4-nitroquinoline 1-oxide (4-nqo) treatment or by 60co-gamma ray irradiation were fused by these simian retroviruses. non-transformed cells derived from normal human embryos were not fused by any of these viruses. of these tu ... | 1980 | 6252085 |
| the protein pattern of pmf virus, a type-d retrovirus from malignant permanent human cell lines. | the protein pattern of a type-d retrovirus (pmfv) isolated from and propagated in human cell lines has been investigated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-page). staining with coomassie blue and labeling with 14c-leucine/14c-lysine revealed five viral polypeptides with molecular weights of 10,000, 12,000, 15,000, 25,000, and 68,000. the 68,000 d-protein was shown to be a glycoprotein by incorporation of 3h-glucosamine and the 15,000 d-protein was identified as ... | 1980 | 7387404 |
| detection of type d retrovirus in a human amnion cell line (fl). | this paper describes the detection of viral particles in a human amnion cell line (fl). these particles belong to the group of type d retroviruses, because of their characteristic morphology, their major antigenic determinants, and the presence of particle-associated mg++-preferring rna-dependent dna polymerase. in addition to budding and mature type d virus particles, intracytoplasmic type a structures have also been found. immunological analysis provided evidence of cross-reactivity between th ... | 1980 | 6784700 |
| feasibility studies of oncornavirus production in microcarrier cultures. | studies conducted with virus-infected monolayer cell cultures have demonstrated the feasibility of producing several tumor-associated viruses in microcarrier (mc) cultures (sephadex g50 beads treated with deae-chloride). the efficiency of cell adherence to mc varied with the cell type, the ph of the growth medium, and the stirring force applied to keep the mc in suspension. most cells attached firmly to the mc and could not be removed easily with routine trypsinization procedures. techniques usi ... | 1980 | 6993346 |
| effect of tunicamycin on cell fusion induced by mason-pfizer monkey virus. | mason-pfizer monkey virus, a d-type retrovirus, has been shown to induce multinucleate cell (syncytium) formation or cell fusion in several normal primate cells. a series of experiments has been carried out to examine whether a glycosylated "fusion-inducing" product is responsible for this biological property of mason-pfizer monkey virus. treatment of rhesus monkey fetal lung cells with different concentrations of tunicamycin, a potent inhibitor of glycosylation, during infection with mason-pfiz ... | 1981 | 7241666 |
| type d retroviruses from human cells do not contain a minor glycoprotein shared by old world monkey type d viruses. | the protein patterns of type d retroviruses isolated either from permanent human cells (hela virus, hela v, and hep-2 virus, hep-2v) or from spectacled langur (langur virus, lv), an old world monkey, were investigated using sodium dodecyl sulfate polyacrylamide gel electrophoresis. labeling with 14c-amino acids and 3h-glucosamine revealed for each of these isolates five polypeptides with molecular weights of 10,000, 12,000, 15,000, 25,000 and about 68,000 and identified the 68,000 d-protein as a ... | 1981 | 7332488 |
| [phorbol ester-induced expression of primate retroviruses (author's transl)]. | addition of the tumor promoter 12-0-tetradecanoyl-phorbol-13-acetate (tpa) to the growth medium of certain human cell cultures persistently infected with simian retroviruses of type c (baev, ssv) or type d (mpmv) or a human cell line-derived type d isolate (pmfv), respectively, resulted in a considerable but transient stimulation of virus production. enhanced virus expression was paralleled by striking morphological alterations of the cells. among four infected cell types tested so far, ony one ... | 1981 | 6279052 |
| demonstration of antigenic cross-reactivity between simian sarcoma virus (ssv) and mason-pfizer monkey virus (mpmv): brief report. | 1981 | 6171238 | |
| use of sepharose bead immunofluorescence assay for comparison of the type d retroviruses mpmv and pmfv. | mason-pfizer monkey virus (mpmv) and pmfv, an isolate from a human continuous cell line, were compared by sepharose bead immunofluorescence assay. according to the results with p27-specific assays the main structural protein of both viruses seems to be identical in the prominent antigenic determinants. differences were found when comparing the p15s indicating that this viral protein contains type-specific antigenic determinants. | 1982 | 6182856 |