Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| study of group-specific proteins in mammalian cells transformed by rous sarcoma virus. | lysates of various mammalian rsv-transformed cells labelled with 35s-methionine were tested for the presence of gs proteins and for the size of these molecules by means of antisera, using sodium dodecyl sulphate--polyacrylamide slab gel electrophoresis. in no case was the presence of gs proteins detected in the analyzed immunoprecipitates; only in rsh-mix cells a quantitative difference in the contrast of a 70 000-molecular weight protein was found. the autoradiograms of simultaneously tested im ... | 1978 | 208874 |
| [immunological and structural properties of rous sarcoma virus-transformed and tumor cells]. | we compared the capacity of both normal and rous sarcoma virus (rsv)-transformed chicken embryo fibroblast (cef) cells as well as rous sarcoma (rs) tumor cells to serve as targets in anti-tumor immunity assays. these studies showed that sera from tumor-bearing donors were able to stain transformed cef more efficiently than rs cells as detected by immunofluorescence. in contrast, antiserum against the major viral glycoprotein, gp 85, stained a higher percentage of rs than transformed cells. norma ... | 1978 | 209500 |
| brain tumors induced in hamsters by intracerebral inoculation of sr-rsv-infected embryonic brain cells. | brain tumors were induced in syrian hamsters by intracerebral inoculation of brain cells which were obtained from 12-day old syngeneic hamster and infected with schmidt-ruppin strain of rous sarcoma virus (sr-rsv) in vitro. a total of 212 tumors were developed in all 25 recipients within 19 to 125 days after transplantation. on the basis of light and electron microscopic study, they were classified into four main groups: astrocytoma (45.8%), pleomorphic glioma (50.0%), sarcoma (3.8%), unclassifi ... | 1978 | 210620 |
| differential expression of rous sarcoma virus-specific transformation parameters in enucleated cells. | chicken embryo fibroblasts transformed with the ta and ts68 mutants of rous sarcoma virus (rsv) were enucleated and studied for their capacity to express reversibly the transformed phenotype in response to temperature changes. after shift to the permissive temperature (35 degrees c), the cytoplasts acquired a transformed morphology and displayed characteristic ruffles and microvilli at their surface. as detected by immunofluorescence, they also lost their actin filament cables and exhibited char ... | 1978 | 210958 |
| regulation of expression and chromosomal subunit conformation of avian retrovirus genomes. | we have investigated the copy number, chromosomal subunit conformation and regulation of expression of integrated avian retrovirus genomes. our results indicate that there are approximately two copies of the endogenous viral genomes (rav-o) per haploid cell genome in uninfected chick embryo fibroblasts (cef) and red blood cells (rbc). the copy number and subunit conformation (as measured by dnaasel sensitivity) of the rav-o genomes are independent of the level of expression of these viral dna se ... | 1978 | 210959 |
| reversion of temperature sensitive transformation mutants of rous sarcoma virus and its effect on the expression of tumour specific surface antigen. | rous sarcoma virus (rsv) mutants, which bear temperature sensitive (ts) defects in both the maintenance of cell transformation and the expression of tumour specific cell surface antigen(s) (tssa), have yielded a number of revertants. in seven revertants studied, the acquisition of wild type transforming capacities is always accompanied by a wild type tssa expression. this strongly indicates that transformation and tssa expression in rsv are affected by the same mutation. | 1978 | 211200 |
| large-scale production, concentration and purification of rous sarcoma virus in tissue culture. | a method is described for long-term standard production of purified virus from cultures of pr-rsv-c-transformed chicken cells. the mean yields were 4.91 mg of purified virus per liter of culture medium. cells were grown in long-term cultures for 26 weeks. a combination of polyethylene glycol 6 000 precipitation and zonal centrifugation has been found satisfactory for virus concentration and purification. | 1978 | 212330 |
| transfer of duck cell dna sequences to the nucleus of 3t3 cells by rous sarcoma virus. | peking duck cell nuclear dna has no complementarity to rna of prague c rous sarcoma virus (rsv). upon infection of peking duck cells by prague c rsv, polynucleotide sequences complementary to peking duck cell nuclear dna can be detected in the high molecular weight rna from progeny peking duck cell passaged rsv (rsvpd) by rna.dna molecular hybridazation. when 3t3 cells are subsequently infected by rsvpd, polynucleotide sequences complementary to peking duck cell nuclear dna can be detected in th ... | 1978 | 212741 |
| characterization of rous sarcoma virus src gene products synthesized in vitro. | the cell-free synthesis of three major proteins from virion rna of nondefective rous sarcoma virus (rsv), but not from rna of transformation-defective deletion mutants, has been observed. the apparent molecular weights of these transformation-specific proteins are approximately 60,000 (60k), 25k, and 17k. tryptic maps of methionine-containing peptides revealed the 17k, 25k, and 60k proteins to be overlapping in sequence. however, only partial homology was observed between the 17k, 25k and 60k pr ... | 1978 | 214578 |
| analysis of rous sarcoma virus (rsv) rna structure by means of specific nucleases. | 1978 | 214951 | |
| metabolism of acetylcholine receptor in chick embryo muscle cells: effects of rsv and pma. | we have investigated some aspects of the metabolism of the integral membrane protein acetylcholine receptor (achr) in normal and transformed cultures of chick embryo muscle cells. turnover of achr in control muscle cell cultures was compared with turnover in cultures infected and transformed by a temperature-sensitive mutant of rous sarcoma virus (rsv) and with cultures treated with the tumor promoter phorbol myristate acetate (pma). the parameters of achr metabolism were estimated using 125i-al ... | 1978 | 215321 |
| plasminogen activator in chick embryo muscle cells: induction of enzyme by rsv, pma and retinoic acid. | to explore the generality of the effects of sarcoma viruses, tumor-promoting phorbol esters and retinoic acid, we have studied plasminogen activator production in differentiating chick myogenic cultures. although slightly higher than in chick fibroblast cultures, the level of spontaneously synthesized enzyme is low; it reaches a peak shortly after maximum cell fusion has been completed and then declines. rous sarcoma virus (rsv) transformation of differentiating myotubes was accomplished by infe ... | 1978 | 215322 |
| nucleotide sequence relationships between the genomes of an endogenous and an exogenous avian tumor virus. | we have used mapping of large t1 oligonucleotides to examine the genome of rous-associated virus-o (rav-o), an endogenous virus of chickens, and to compare it with that of prague strain rous sarcoma virus, subgroup b, (pr-rsv-b), an exogenous sarcoma virus. to extend the sensitivity of such comparisons, we have developed a system of nucleic acid hybridization and hybridization-competition combined with fingerprinting. this method allows us to estimate the relative degree of relatedness of variou ... | 1978 | 215788 |
| systemic and topical use of poly i.c. in treatment of generalized neonatal herpes simplex infection with severe ocular involvement. | a case of neonatal herpes simlex virus (rsv) encephalitis with severe ocular manifestation treated by topical systemic and intrathecal interferon inducer, poly ic (polyriboinosinic acid-polyribocytidylic acid) is reported. prior to the administration of poly ic, no interferon could be detected neither in blood nor in csf and vesicular fluid from conjunctiva. intravenous administration of the drug initiated measurable levels in blood and tears, but not in csf. however, intrathecal injection induc ... | 1978 | 216790 |
| lack of correlation between tumorigenicity and level of plasminogen activator in fibroblasts transformed by rous sarcoma virus. | we have previously isolated, from agar suspension culture, clones of chicken embryo fibroblasts transformed by b77 and prague strains of rous sarcoma virus (rsv) that varied in the expression of plasminogen activator activity [wolf, b. a. & goldberg, a. (1976) proc. natl. acad. sci. usa 73, 3613-3617]. all of the clones exhibited an altered cellular morphology, an increased rate of sugar transport, and a high efficiency of colony formation in agar suspension regardless of the level of plasminoge ... | 1978 | 217007 |
| oncornavirus modification of the golgi apparatus. | two virus system, the friend leukaemia virus (flv) and the rous sarcoma virus (rsv), were introduced into tissue both in vitro and in vivo. both brought about substantial modification of the activity of the golgi apparatus detectable as such by specific radioautographic studies. this modification was accompanied by changes in the development and social behaviour of the cells with some differences being detectable between the in vivo and in vitro studies. | 1978 | 223815 |
| decreased alkaline phosphatase in cells transformed by rous sarcoma virus. | chick embryo cells transformed by either of two strains of rous sarcoma virus (bryan high titer or schmidt-ruppin) have low levels of alkaline phosphatase activity compared with nontransformed chick embryo cells. essentially no differences in acid phosphatase activity were observed between these transformed and nontransformed cells. a virus mutant, rsv-bh-ta, induces temperature-dependent transformation in infected cells. at 41 degrees, the transformation-nonpermissive temperature, alkaline phos ... | 1978 | 202384 |
| quantitation and localization of rous sarcoma virus-specific rna in transformed and revertant field vole cells. | hybridization analysis of rna from transformed clones of rous sarcoma virus (rsv)-infected field vole cells and revertant subclones indicated the presence of similar amounts of viral-specific rna in both cell types. employing both a relatively uniform and representative complementary dna probe and genomelength complementary dna, we have demonstrated that the majority of rsv proviral dna is transcribed into viral-specific rna in both transformed and revertant clones. the viral-specific rna is pre ... | 1978 | 203719 |
| multiple forms of sarc gene proteins from rous sarcoma virus rna. | in a previous study we were able to identify two proteins of 25,000 and 18,000 daltons that were made from rna of transforming virions of rous sarcoma virus (rsv) and that were missing from the translation products of a transformation-defective deletion mutant of rsv. in the present study we have separated rsv virion rna on sucrose gradients and have determined that the two putative sarc gene products are synthesized as doublets from an mrna of approximately 18 s. there also appear to be several ... | 1978 | 203938 |
| effects of dexamethasone on the morphogenesis of two mutants of rous sarcoma virus. | japanese quail cells transformed by the replication-defective, bryan high-titer strain of rous sarcoma virus, bh rsv(-)q, clone 3, revealed intracytoplasmic a-type particles after dexamethasone treatment. in the absence of dexamethasone, or when superinfected with a helper virus in the presence or absence of dexamethasone, no such particles were observed. chick embryo cells (cec) infected with a temperature-sensitive sarcoma virus mutant, la 334, coordinately defective for transformation and vir ... | 1978 | 204599 |
| intracellular precursors to the major glycoprotein of avian oncoviruses in chicken embryo fibroblasts. | a 96,000-dalton glycoprotein, p(96), was present in cell extracts obtained from gs-chf- chicken embryo fibroblasts infected with the avian rna tumor viruses rous-associated virus-2 subgroup b (rav-2) and the schmidt-ruppin strain of rous sarcoma virus subgroup a (sr-rsv-a), as well as from uninfected gslchf+ (he) cell extracts. it was not found in cell extracts from uninfected gs-chf- or gs+chf+ (hh) cells, nor from gs-chf- cells infected with envelope-deficient bryan high-titer rous sarcoma vir ... | 1978 | 205673 |
| an avian oncovirus mutant (se 21q1b) deficient in genomic rna: biological and biochemical characterization. | we have isolated a nonconditional mutant of pr-rsv-e with unique properties. this virus (se 21q1b) is shed from a continuously growing culture of transformed quail cells. 21q1b virions are unable to transform or replicate in other quail or chicken cells after exogenous infection, despite the fact that the viral particles contain normal envelope glycoproteins, internal structural proteins and rna-dependent dna polymerase. the lack of infectivity of 21q1b virions is a consequence of the failure to ... | 1978 | 83199 |
| detection of antibody to bovine syncytial virus and respiratory syncytial virus in bovine fetal serum. | batches of commercial fetal bovine serum, described by the suppliers as antibody-free, all contained antibody to bovine syncytial virus (bsv) when tested by indirect immunofluorescence. antibody to bovine respiratory syncytial virus (rsv) was not detected in these sera. twenty-four percent of individual fetal bovine sera contained antibody to bsv, and 14% contained antibody to rsv when tested by indirect immunofluorescence. bsv antibody titers in fetal sera from dams with high bsv antibody level ... | 1978 | 100508 |
| cytoplasmic vacuoles of rous virus transformed cells are organelles involved in cation uptake. | cytoplasmic vacuoles induced during transformation of cells by bryan strain rous sarcoma virus (rsv-bh) have been studied using the cationic dye, neutral red(nr). both the rate of uptake and the accumulation of nr are greater in rsv-bh transformed cells than non-transformed cells however, uptake was greater in vacuolated than in non-vacuolated cells, whether or not they were transformed. the nr was incorporated into pre-existing vacuoles in the absence of cytoplasmic staining, suggesting the exi ... | 1978 | 24677 |
| decreased levels of collagen mrna in rous sarcoma virus-transformed chick embryo fibroblasts. | we have found that double-stranded cdna synthesized in extended reactions by avian myeloblastosis virus reverse transcriptase is suitable substrate for a variety of restriction endonucleases. experiments in which rabbit reticulocyte mrna was reverse-transcribed and restricted to generate beta-globin-specifihe nucleotide sequence of beta-globin mrna. this method has been applied to study collagen mrna synthesis in normal and rous sarcoma virus (rsv)-transformed chick embryo fibroblasts. character ... | 1978 | 78927 |
| tumor-specific and tumor-associated membrane antigens of rous sarcoma virus transformed hamster fibroblasts. | hamster fibroblasts transformed by an env- strain of rous sarcoma virus (rsv) express at their surface tumor-associated antigens of unknown origin and a tumor-specific antigen (vcsa) which is not expressed by hamster fibroblasts transformed by unrelated dna or rna oncogenic viruses. this antigen was detectable by rabbit antibodies and a complement-dependent 51cr-release cytotoxicity assay and is common to rsv-transformed cells of different animal species. by comparing the anti-vcsa serum which a ... | 1978 | 79559 |
| effect of isonicotinic acid hydrazide-copper complex on rous sarcoma virus and its genome rna. | the copper complex of the antituberculous drug, insonicotinic acid hydrazide (inh), inhibits the rna-dependent dna polymerase of rous sarcoma virus and inactivates its ability to malignantly transform chick embryo cells. the inh-copper complex binds to the 70s genome rna of rous sarcoma virus (rsv), which may account for its ability to inhibit the rna-dependent dna polymerase. the complex binds rna more effectively than dna in contrast to m-ibt-copper complexes, which bind both types of nucleic ... | 1978 | 80234 |
| [detection of common antigenic determinants in the envelopes of mammalian type d (mason--pfizer) and type c virions by using the virion precipitation reaction]. | immune sera to mason-pfizer virus (m-pmv) are capable of precipitating type c viruses of mice (nih-mulv, g-mulv, and to a lower degree r-mulv), cats (felv, rd-114), and monkeys (ssv-1, galv, bev). the immune sera to rd-114, bev, ssv-1 and galv viruses can precipitate m-pmv virions. the adsorption analysis suggests that cross-reactions between m-pmv, rd-114, nih-mulv, and g-mulv viruses depend on common virus-specific antigenic determinants in the envelopes of the virions. the relationship betwe ... | 1978 | 80888 |
| characterization of rna polymerases from rous sarcoma virus-induced mouse ascites sarcoma cells. | rna polymerase was extracted from the schmidt-ruppin strain of rous sarcoma virus (sr-rsv)-induced c3h/he mouse ascites sarcoma cells (sr-c3h). rna polymerase was separated into rna polymerases i and ii by deae-sephadex chromatography. rna polymerase i was separated into ia and ib fractions by phospho-cellulose chromatography. in sr-c3h cells rna polymerase ib was the main component of rna polymerase i. at 0.05--0.1 m ammonium sulphate rna polymerase i transcribed native dna most actively, and r ... | 1979 | 38635 |
| the longitudinal approach to the pathogenesis of respiratory disease. | longitudinal observations were made of a well-defined population of children at a day care center in an investigation of the pathogenesis of infections due to respiratory syncytial virus (rsv) and mycoplasma pneumoniae. a single rsv infection induced a modest but significant degree of resistance to further rsv infection in these children. age and immunity seemed to interact to decrease the intensity of the clinical expression of illness associated with rsv infection. infants and young children h ... | 1979 | 121783 |
| [oncornavirus activation and accumulation in cell cultures under the influence of hormones]. | sex hormones (testosterone, estradiol) and thyroxine would activate irregularly the production of the specific group antigen (gs-antigen) of avian ribodesoxyviruses in the culture of "normal" chick embryonal cells (cec, phenotype c/o, gs-). the mentioned hormones as well as hydrocortisone and insulin would not prevent the rous sarcoma virus (rsv) infecting of cec, render no essential action on the accumulation of rsv in the infected cec culture, and failed to activate the formation of mature rsv ... | 1979 | 85368 |
| development of allergy in children. i. association with virus infections. | children born into allergic families, with two allergic parents, are at high risk of developing allergy within the first 5 years of life. in order to observe possible external factors in the sensitization process, a prospective study of 13 such children was done, in which serial clinical and immunologic observations were made at 3- to 6-month intervals over a period of 1 to 4 yr. eleven of these children are now clinically allergic; 5 have asthma. immunologic evidence for allergic sensitization ... | 1979 | 85648 |
| plasma membrane phosphoproteins in normal and rous sarcoma virus transformed chick embryo fibroblasts: characterization by in vitro phosphorylation. | plasma membranes isolated from normal and rsv transformed chick embryo fibroblasts were phosphorylated in vitro using endogenous protein kinase and atp (gamma32p) and the labeled phosphoproteins were analyzed by sds-page. a number of protein phosphorylation changes were observed following transformation, however in most cases they were relatively small quantitative differences. the four major changes were in proteins of 47,000, 58,000, 75,000 and 135,000 daltons. decreased phosphorylation of the ... | 1979 | 224069 |
| comparative study of tumor-specific transplantation antigens of mc-29 chicken hepatoma and rous sarcoma virus-induced sarcomas in mice. | immunization of cbat6t6 mice with mc-29 hepatoma antigen did not change the take of rous sarcoma virus, schmidt-ruppin strain [rsv(sr)] mouse tumors after sc transplantation. immunization with mc-29 hepatoma antigen only slightly increased the average survival time of the mice and significantly decreased tumor growth only at the minimal lethal dose level. immunization of mice with mc-29 hepatoma antigen and immunization with chicken rous sarcoma gave similar results; both elicited much less tran ... | 1979 | 224208 |
| continuous lines of rsv-transformed embryo cells and peritoneal macrophages of japanese quails. | four continuous lines of rsv-transformed quail cells were established; qerc-31f and qerc-31n cells derived from quail embryo cells and perp and pery cells from adult quail peritoneal macrophages. marked morphological difference was noted between qerc-31f and qerc-31n; the former showed fusiform shape and the latter nodular shape. both perp and pery showed macrophage-like morphology with phagocytic capacity. all four cell lines contained gs antigen and gp 85. production of transforming virus was ... | 1979 | 224231 |
| restriction of patching of bound concanavalin a after incorporation of arachidonic acid into the plasma membrane of virally transformed fibroblasts. | topographical distribution of concanavalin a binding sites (cabs) was studied in two lines of virally transformed fibroblasts as a function of fatty acid composition. fatty acid composition was manipulated by incubating cells in fatty acid, atp, coa, and delipidated fetal calf serum (fcs). vlm cells grown in medium containing 5% fcs have a clustered cabs distribution. plasma membrane vesicles (pmvs) derived from these cells have an arachidonate content of 1.7%. elevation of pmv arachidonate to 1 ... | 1979 | 229111 |
| genetic nature of regression of rous sarcoma virus-induced tumors in crosses of regional poultry research laboratory lines 6 and 7(2). | regional poultry research laboratory (rprl) inbred lines 6(1), 6(3), and 7(2) and f1, f2, and reciprocal backcross progenies of these lines were used to investigate host-gene effects upon the regression of rous sarcoma virus (rsv)-induced tumors. lines 6(1) and 6(3) were susceptible to subgroup a and c lymphoid leukosis (ll) viruses and line 7(2) was resistant to subgroup a but was segregating for susceptibility to subgroup c ll virus. viruses of rsv subgroups a and c were used. lines 6(1), 6(3) ... | 1979 | 229477 |
| clones of cells from a human embryo lung: their growth and susceptibility to respiratory viruses. | colonies of cells were obtained from human fetal lung tissue and exposed to recently isolated respiratory viruses. there was a considerable variation in the number of rounded cells found in different colonies exposed to rhinovirus types 2 and 9 (rv2 and 9), human coronavirus 229e (hcv), adenovirus type 3 (ad3) and respiratory syncytial virus (rsv). smaller colonies had more rounded cells than larger colonies. clones were established from 9 out of 11 colonies. they varied in their rate of growth ... | 1979 | 229795 |
| studies of the effect of chloramphenicol, ethidium bromide and camptothecin on the reproduction of rous sarcoma virus in infected chick embryo cells. | a function for mitochondria in the reproduction of rous sarcoma virus (rsv) in chronically and newly infected chick embryo cells was studied by using chloramphenicol and ethidium bromide. chloramphenicol (cam) and ethidium bromide (eb) were both shown to decrease the rate of growth of infected chick embryo cells and to inhibit the synthesis of mitochondrial macromolecules. both drugs however had little or no effect on the incorporation of labelled leucine, thymidine and uridine into total cellul ... | 1979 | 230286 |
| the influence of host adaptation of rous sarcoma virus on the transfecting activity of its dna provirus. | mammalian cells transformed with either prague strain rous sarcoma virus of subgroup c (xc cells) or schmidt-ruppin strain rous sarcoma virus of subgroup d (rsch cells) yielded virus upon fusion with chick cells. virus was also rescued by transfection of dna from these cells on to chick cells. however, virus rescue did not occur upon transfection of duck cells, and fusion with duck cells led to virus rescue only from rsch and not from xc cells. to investigate this restriction on the duck cells t ... | 1979 | 230300 |
| transplacental cancerization by rous sarcoma virus. | experimental data obtained in the mouse are presented, pointing to the possibility of transplacental transmission of the genetic information contained in the genome of rous sarcoma virus(rsv), by either intact rsv virions or nucleic acids extracted from infectant suspensions of tumors induced by the carr(ziber) on bryan rsv strains. | 1979 | 231860 |
| cell fusion for genetic analysis of two nonconditional rous sarcoma virus replication mutants. | procedures for characterizing replication-defective viruses in nonpermissive mammalian cells were developed and applied to three nonvirogenic rous sarcoma virus (rsv)-transformed mammalian cell lines--b4, a line of bryan virus-transformed hamster cells, and two srd-rsv transformed rat cell lines, lr3/1 and lr3/2. cell fusion was used to study virus complementation. the three cell lines (i) fused with helper virus-infected chicken cells and the host range of the rescued virus examined, (ii) teste ... | 1979 | 232170 |
| heterogeneous rna of the prague strain of rous sarcoma virus caused by undiluted passages. | the size of genomic rna in pr-rsv a passaged in chick embryo fibroblasts (cef) or quail embryo fibroblasts (qef) was determined by gel electrophoresis. the results showed that 3 undiluted passages resulted in heterogeneity of rna. the heterogeneity of the smaller incomplete rnas in the virus stock was decreased by diluted passage or cloning, but rna of the b subunit size and a subunit rna of complete genome size were relatively stable. these heterogeneous rnas were characterized by hybridization ... | 1979 | 232236 |
| effect of vitamin a on plasminogen activator synthesis by chick embryo fibroblasts. | low concentrations of vitamin a stimulated plasminogen activator synthesis (pa) in chick embryo fibroblasts (cef). it caused a dose dependent and reversible increase in pa synthesis in both normal cef and cef infected with a temperature sensitive mutant of rous sarcoma virus (rsv-ts68). both induction and deinduction of pa could be inhibited by actinomycin d. vitamin a also accentuated the morphological changes associated with transformation in the rous sarcoma virus infected cells. the effects ... | 1979 | 232460 |
| effects of the tumor promoter tpa on the induction of dna synthesis in normal and rsv-transformed rat fibroblasts. | induction of dna synthesis by the tumor promoter tetradecanoyl phorbol acetate (tpa) was studied in a line of cultured rat fibroblasts (rat-1) and their rous sarcoma virus-transformed derivative (rat-1 (rsv)). following serum deprivation for 54 h to achieve quiescence, semiconservative dna replication was measured by incubation of cells in brdurd and fdurd after serum stimulation in the presence or absence of tpa. optimal concentrations of tpa (0.1--0.5 microgram/ml) in serum-free medium induced ... | 1979 | 232527 |
| [fragments of linear unintegrated rous sarcoma virus dna, resulting from digestion with smai restriction endonuclease]. | linear unintegrated dna of schmidt-ruppin rous sarcoma virus, subgroup d (sr-rsv-d), was digested with smai restriction endonuclease, analyzed by agarose gel electrophoresis, "blotted" by southern's method and hybridized with a viral 32p cdna. smai cleaves this dna at five sites, two of which are localized at the ends of the provirus. src and env genes seem not to be restrictied by smai cleavage. | 1979 | 232859 |
| immunofluorescence on avian sarcoma virus-transformed cells: localization of the src gene product. | the localization of the avian sarcoma virus src gene product (termed p60src) was examined by indirect immunofluorescence in cells transformed by the schmidt-ruppin strain of rous sarcoma virus, subgroup d (sr-rsv-d). antiserum to p60src was obtained from rabbits bearing sr-rsv-d-induced tumors, and immunofluorescence was performed on chicken embryo fibroblasts (cef) transformed with sr-rsv-d, as well as normal rat kidney (nrk) cells transformed by the same virus (termed sr-rk cells). both aceton ... | 1979 | 217542 |
| characterization of the genomic rna from a rous sarcoma virus mutant temperature sensitive for cell transformation. | we have found that the la23 t/s mutant of rous sarcoma virus (phenotype prague b), even when passaged repeatedly at high multiplicity of infection, does not give rise to transformation defective deletion mutants comparable to those derived from rsv. in view of this fact and of the high rate of production of this mutant at 41 degrees c, we have undertaken a detailed analysis of the genome of this virus by ordering all large t1 oligonucleotides and by determining their nucleotide sequences. the re ... | 1979 | 218172 |
| src gene product from different strains of avian sarcoma virus: kinetics and possible mechanism of heat inactivation of protein kinase activity from cells infected by transformation-defective, temperature-sensitive mutant and wild-type virus. | sera from certain rabbits bearing schmidt-ruppin strain rous sarcoma virus (rsv)-induced tumors precipitated p60(src) from chicken cells transformed by the homologous virus as well as by other strains [prague strain rsv, bryan high-titer strain rsv, and bratislava 77 strain of avain sarcoma virus (asv)], the molecular weights (m(r)s) ranging from 60,000 to 64,000. the p60(src) immunoprecipitated from cells transformed by each of these strains incorporated [gamma-(32)p]atp into the m(r) 53,000 su ... | 1979 | 218225 |
| characterization of some isolates of newly recovered avian sarcoma virus. | we previously reported the isolation of a newly recovered avian sarcoma virus (rasv) from tumors of chickens injected with transformation-defective (td) mutants of the schmidt-ruppin strain of rous sarcoma virus (sr-rsv). in this paper, we present further biological and biochemical characterization of the recovered sarcoma viruses. high titers of rasv's were generally obtained by cocultivation of tumor cells with normal chicken embryo fibroblasts or by homogenization of tumor tissues. most rasv ... | 1979 | 219237 |
| the kinetics of synthesis of infectious unintegrated virus dna in rous sarcoma virus infected chicken cells. | infectious virus nucleic acids were extracted from the hirt supernatant of chicken embryo fibroblasts infected for different times with the schmidt-ruppin strain of rous sarcoma virus (rsv). infectious dna and dna-rna hybrid molecules could be recovered from 6 h after infection in experiments using 1.5 x 10(9) infected cells. only small amounts of infectious virus dna could be purified 6 h after infection whereas at 24 h approximately one infectious dna molecule could be recovered for each input ... | 1979 | 215710 |
| messenger activity of virion rna for avian leukosis viral envelope glycoprotein. | an intracellular assay for viral envelope glycoprotein (env) messenger was employed to analyze the rna from virus particles of rous-associated virus type 2. for this assay rna was microinjected into cells infected by the env-deficient bryan strain of rous sarcoma virus [rsv(-) cells]. only when the injected rna could be translated by the recipient cells to produce viral envelope glycoprotein was the env deficiency of the rsv(-) cells complemented, enabling them to release focus-forming virus. rn ... | 1979 | 221682 |
| specific rna sequences of rous sarcoma virus (rsv) recovered from tumors induced by transformation-defective rsv deletion mutants. | 1979 | 222048 | |
| neural crest cells: temperature-dependent transformation by rous sarcoma virus. | cranial neural crest cells from chick embryos, when cultured under appropriate conditions, differentiate after approx. 1 week into pigmented cells. neurol crest cells were infested with a mutant (rsv-bh-ta) of the bryan 'high titer' strain of rous sarcoma virus on the second day of culture before the cells were morphologically differentiated, or later after they became pigmented. cells infected and maintained at the temperature permissive for transformation (37 degrees c) proliferated rapidly co ... | 1979 | 222481 |
| assays for endogenous and exogenous lymphoid leukosis viruses and chick helper factor with rsv(--) cell lines. | japanese quail cells transformed by the envelope-defective bryan high-titer strain of rous sarcoma virus [r(-)q] were used as a source of the rous sarcoma virus genome in three kinds of assays. (i) the simplest and most sensitive assay for infectious, endogenous viruses of the chicken belonging to subgroup e involved infection of a mixture of r(-)q cells and turkey cells with the sample and assay of supernatants of these cells for focus formation on subgroup e susceptible cells. (ii) inactivated ... | 1979 | 222685 |
| detection of respiratory syncytial virus in nasal secretions from infants by enzyme-linked immunosorbent assay. | an enzyme-linked immunosorbent assay (elisa) was developed for detection of respiratory syncytial virus (rsv) in nasal secretions from infants with respiratory disease. rsv was detected in 23 of 29 secretions positive for rsv by tissue culture and in one of 36 samples negative for rsv by tissue culture. the elisa was a simple rapid, and surprisingly sensitive test for identification of rsv infection in infants. | 1979 | 374650 |
| reye's syndrome associated with respiratory syncytial virus infection. | an upper respiratory tract infection in a 22-month-old boy was followed by rapid loss of consciousness, hypoglycaemia, uraemia, and death. necropsy examination showed fatty change of liver and kidneys, severe cerebral oedema, bronchiolitis, and endocardial fibroelastosis affecting the left ventricle. immunofluorescence staining showed infection with respiratory syncytial virus (rsv). the clinical and pathological findings were those of reye's syndrome, not previously reported accompanying rsv in ... | 1979 | 420528 |
| cell-free and cell-bound antibody in nasal secretions from infants with respiratory syncytial virus infection. | twenty-two infants under 9 months of age hospitalized with bronchiolitis or pneumonia due to respiratory syncytial virus (rsv) were serially sampled to determine the pattern of secretory antibody response. using double labeling techniques, we found several types of immunoglobulin in secretions: cell-free antibody to rsv of the immunoglobulin a (iga), immunoglobulin g (igg), and immunoglobulin m (igm) classes; and immunoglobulins of all three classes bound to rsv-infected cells shed from the nasa ... | 1979 | 422241 |
| cell-mediated immune response to respiratory syncytial virus infection: relationship to the development of reactive airway disease. | the possibility that cell-mediated immunity might play a role in the pathogenesis of infection with respiratory syncytial virus was evaluated in a study of 39 infants. infection with rsv was confirmed by identification of virus in nasopharyngeal secretions using immunofluorescence, and by tissue culture infectivity. cmi, as determined by a whole blood lymphocyte transformation technique, was evaluated in samples taken 0 to 10 and 20 to 60 days after the onset of illness. patients diagnosed as ha ... | 1979 | 423016 |
| the etiologic and epidemiologic spectrum of bronchiolitis in pediatric practice. | to develop a broad understanding of the causes and patterns of occurrence of wheezing associated respiratory infections, we analyzed data from an 11-year study of acute lower respiratory illness in a pediatric practice. although half of the wari occurred in children less than 2 years of age, wheezing continued to be observed in 19% of children greater than 9 years of age who had lower respiratory illness. males experienced lri 1.25 times more often than did females; the relative risk of males fo ... | 1979 | 448557 |
| fibronectin from chicken embryo fibroblasts contains covalently bound phosphate. | fibronectin isolated from cultures of chicken embryo fibroblasts (cef) contains phosphorus linked to serine and threonine by monoester bonds. normal and rous sarcoma virus (rsv)-transformed cells were incubated with [32p]orthophosphate, and fibronectin was isolated from the cell surfaces and conditioned media. 32p was stably associated with fibronectin during immunoprecipitation, sds-polyacrylamide gel electrophoresis, phospholipid solvent extraction, and hot acid but not alkaline treatment. aft ... | 1979 | 457771 |
| clinical and physiological manifestations of bronchiolitis and pneumonia. outcome of respiratory syncytial virus. | the physiological abnormalities and clinical correlates of 32 infants consecutively hospitalized with lower respiratory tract disease from respiratory syncytial virus (rsv) were studied in an attempt to characterized the infant most at risk for the acute and long-term complications of rsv infection. arterial oxygen saturation (sao2) determinations were obtained daily by means of an ear oximeter. on admission all infants were hypoxemic with a mean sao2 of 87% (range, 74% to 95%). the mean of the ... | 1979 | 463835 |
| experimental respiratory syncytial virus infection in feeder-age lambs. | signs of disease, lesions, and serologic response were seen in six 6-month-old-lambs experimentally inoculated with respiratory syncytial virus (rsv). a transient febrile response, mild hyperpnea, and listlessness were seen. multifocal areas of interstitial pneumonia and bronchiolitis were seen in lambs necropsied during the period of clinical response. a serologic response to rsv was seen in all lambs, and rsv was recovered from five lambs. | 1979 | 525890 |
| antibody-dependent cell-mediated cytotoxicity against cells infected with respiratory syncytial virus: characterization of in vitro and in vivo properties. | an in vitro 51cr release assay for human antibody-dependent cell-mediated cytotoxicity (adcc) against hela cells infected with respiratory syncytial virus (rsv) has been characterized by using leukophoresed and adherent cell-depleted adult lymphocytes. lymphoytes from rsv seronegative children were also competent as effector cells. sera from children with :1) primary and recurrent natural rsv infections, or 2) live attenuated rsv vaccine infection were examined to characterize the behavior of ad ... | 1979 | 571890 |
| incidence of rs virus infections in premature children's ward. | in the course of two years (1974-76) four outbreaks of acute respiratory disease in the premature children's ward of a prague hospital were studied virologically and clinically. rs virus (rsv) was found to be the aetiological agent. the highest isolation rate of rsv was achieved when using two heteroploid cell lines (l-132 and hep-2 cells) simultaneously. of the 30 children examined, 60% showed a severe course of disease (pneumonia and/or bronchiolitis) while in 40% of the children the disease h ... | 1979 | 575897 |
| observations on outbreaks of respiratory disease in calves associated with parainfluenza type 3 virus and respiratory syncytial virus infection. | in four outbreaks of indoor calf pneumonia, dyspnoea was a prominent clinical finding. at necropsy it was associated with pneumonia involving the cranial lobes of the lung and severe pulmonary emphysema. histological examination of lung tissue revealed bronchiolitis and alveolitis with alveolar epithelial cell hyperplasia and multinucleate syncytium formation. intraalveolar haemorrhage, intra-alveolar oedema and hyaline membrane formation were also noted. in all cases parainfluenza type 3 (pi3) ... | 1979 | 219584 |
| inhibition of rous sarcoma-virus-induced transformation by proteins involved in blood coagulation. | plasma, serum and the main proteins involved in the final steps of blood coagulation, fibrinogen, thrombin and plasma transglutaminase, have been tested for their ability to inhibit cell transformation and/or to induce reversion of the transformed to the normal phenotype in rsv-infected chicken embryo fibroblasts. the results obtained show that plasma, and not serum, fibrinogen, when converted to fibrin by thrombin, and activated transglutaminase alone prevent focus appearance and cause reversio ... | 1980 | 6102967 |
| biosynthesis in vitro of mono- and di-sialosylgangliosides from gangliotetraosylceramide by cultured cell lines and young rat brain. structure of the products, and activity and specificity of sialosyltransferase. | incubations in vitro of ga1, labeled with 3h in the terminal d-galactopyranosyl group, with nonradioactive cmp-neunac in the presence of homogenates of c21 rat brain glial cells, nie mouse neuroblastoma cells, 3t3 mouse fibroblasts, sv 40-transformed 3t3 cells, chick embryo fibroblasts, rous sarcoma virus-transformed chick embryo fibroblasts, and 9-day old rat brain resulted in all cases in the formation in high yield of gm1b, in which the neuraminidase-labile neunac group is linked at o-3 of th ... | 1980 | 6243513 |
| purine base composition analysis of normal and tumor rat dna. | chemical and viral induced rat tumors were analyzed for their purine base composition and compared to normal tissue dna's. the tumors were induced by 7,12-dimethylbenz[a]anthracene (dmba), 20-methylcholanthrene (mc), 3,4-benzopyrene (bp), 1,2-dimethylhydrazine (dmh) and rous sarcoma virus (rsv). normal dnas were extracted from colon, caecum, liver, spleen and embryo and used as reference standards for base composition of normal rat dna. the composition of purines was obtained by spectrophotometr ... | 1980 | 6244115 |
| mutant and recombinant avian retroviruses with extended host range. | avian retroviruses of subgroups b and d efficiently infect chicken (c/e) but not turkey (t/bd) cells. we describe here three variants of subgroup b and d viruses that infect both cell types equally well. one of these viruses, ntre-4, was a recombinant between transformation-defective prague (pr) strain rous sarcoma virus (rsv) subgroup b and the endogenous virus rav-0; the second, sr-de-1, was a recombinant between schmidt-ruppin rsv subgroup d and defective endogenous virus information. t1 olig ... | 1980 | 6244565 |
| recombinants between endogenous and exogenous avian tumor viruses: role of the c region and other portions of the genome in the control of replication and transformation. | endogenous retroviruses of chickens are closely related to exogenous viruses isolated from spontaneous tumors in the same species, yet differ in a number of important characteristics, including the ability to transform cells in culture, ability to cause sarcomas or leukemias, host range, and growth rate in cell culture. to correlate these differences with specific sequence differences between the two viral genomes, the genome rna of transforming subgroup e recombinants between the prague strain ... | 1980 | 6245229 |
| transformation of rat cells by fusion-infection with rous sarcoma virus. | the transformation of a rat cell line, 3y1, by nonmammalian tropic strains of avian sarcoma virus was tested using cell-virus fusion mediated by sendai virus or polyethylene glycol. furthermore, the establishment of several transformed 3y1 cell clones induced by the schmidt-ruppin strain of rous sarcoma virus (rsv), its derivative mutants, and the bryan high-titer strain of rsv is reported. the presence and expression of the viral genomes in these cells were examined, and all transformed cell cl ... | 1980 | 6247511 |
| alignment of the peptides derived from acid-catalyzed cleavage of an aspartylprolyl bond in the major internal structural polypeptide of avian retroviruses. | the major internal structural polypeptide (p27) of rous sarcoma virus (rsv), and the analogous polypeptide (p27(0)) of rous-associated virus-o (rav-o), an endogenous virus released spontaneously by some chicken cells) have been cleaved selectively at a single aspartylprolyl peptide bond to yield two fragments. the nh2- and cooh-terminal amino acid sequences of p27 and p27(0) and their mild acid-cleavage fragments have been determined. these results show the existence of an identical cleavage sit ... | 1980 | 6248540 |
| characterization of tumors induced in adult macaca mulata monkeys with carr-zilber strain of rous sarcoma virus. | the carr-zilber strain of rous sarcoma virus is highly oncogenic for adult monkeys of the species macaca mulata. in the present study, we examined some characteristics of tumor growth when the tumor either regressed or progressed until it killed its host. we followed the kinetics of antibody formation to antigens coded by cz-rsv in animals with a different course of tumor disease. the sera of animals tested contained virus-neutralizing antibodies, in addition to gs antibodies. the results are di ... | 1980 | 6248800 |
| rous sarcoma regression in seven highly inbred lines of white leghorns. | response to rous sarcoma virus (rsv)-induced tumors was studied in regional poultry research laboratory (rprl) lines 61, 63, 72, 100, 151, and 15i5 and in reaseheath line c, all highly inbred white leghorn stocks. virus inoculations were made in chickens at 6 weeks of age. tumors were scored subjectively for size on a regular basis and in some instances a tumor profile index (tpi) was assigned which characterized tumor development over a 10 week period for each chicken (tpi 1 = complete regressi ... | 1980 | 6250136 |
| experimental models for study of common respiratory viruses. | numerous epidemiological studies have shown that there is excess respiratory disease morbidity in areas of high atmospheric pollution, implying an interactive effect on the clinical illness associated with these common infections. the principal etiologic agents of human respiratory infections are respiratory syncytial virus (rsv), influenza viruses (iv), parainfluenza virus types 1 and 3 (p1, p3), adenoviruses (ad), rhinoviruses (rv) and mycoplasma pneumoniae (mpn). understanding the pathogenesi ... | 1980 | 6250807 |
| detection of viral markers and incomplete viral genome rescue from asv transformed rodent cells. | two non-virogenic rat cell lines twerc and fr transformed with pr-rsv and fsv, respectively, were analyzed. both these cell lines contained vrna, but only in twerc cells was the major viral polypeptide p27 synthetized. transforming virus can be rescued from both cell lines only after fusing them with chicken fibroblasts preinfected with avian leukosis viruses of subgroup a, c, d, f and both td mutants of pr-rsv-c and b77-c. similarly, virus was rescued in experiments in which qef infected with r ... | 1980 | 6250919 |
| budding of rous sarcoma virus and vesicular stomatitis virus from localized lipid regions in the plasma membrane of chicken embryo fibroblasts. | the origin of the envelope lipids acquired by rous sarcoma virus (rsv) and vesicular stomatitis virus (vsv) during budding from the plasma membrane of chicken embryo fibroblasts was examined. several differences were observed between the lipid composition of rsv and the plasma membrane. when the phospholipid composition of the cells was modified by growing them in the presence of the choline analogues, n,n-dimethylethanolamine or l-2-amino-1-butanol, the phospholipid composition of the virus was ... | 1980 | 6251073 |
| adhesion plaques of rous sarcoma virus-transformed cells contain the src gene product. | another intracellular location of the rous sarcoma virus (rsu) src gene product (pp60src) has been detected within rsv-transformed cells by indirect immunofluorescence. by using rabbit anti-tumor serum specific for pp60src, a speckled pattern of fluorescence was found on the ventral surface of rsv (schmidt-ruppin strain)-transformed normal rat kidney cells. several tests indicated that this pattern was specific for pp60src. in addition, interference-reflection microscopy was used to visualize ce ... | 1980 | 6251464 |
| ["pharaoh" line culture of japanese quail cells as a leukosis-free system for virus reproduction]. | contamination of japanese quail, strain pharaoh, cell culture with oncogenous and infectious avian viruses was studied. the susceptibility of the embryonal cell cultures of the japanese quail, strain pharaoh, to measles, parotitis and fixed rabies viruses was also determined. it was found that the sera of pubertal quails had no antibody to rous sarcoma virus (rsv), strains brian, rsv (rav-1), schmidt-ruppin, carr-zilber, as well as to marek's disease and newcastle disease viruses. no reverse tra ... | 1980 | 6251636 |
| 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 |
| aggregation properties of chondrocytes infected with a temperature-sensitive mutant of rous sarcoma virus. | aggregation capacity of chicken embryo chondrocytes decreases when transformed by rous sarcoma viruses. cell-to-cell aggregation capacity of chondrocytes infected with a t class temperature-sensitive mutant (tsny68) (with the temperature-sensitive lesion at the src gene) of rous sarcoma virus is dependent upon the temperature at which these cells are grown. when grown at the permissive temperature (36 degrees c), where the transforming gene is expressed, aggregation capacity was lower than norma ... | 1980 | 6252220 |
| transformation of nih-3t3 mouse cells by avian retroviral dnas. | nih-3t3 cells were found to be transformable by rsv dna in the absence of progeny virus production. cells transformed by intact rsv dnas contained rescuable rsv genomes that were integrated into cellular dna and were colinear with unintegrated rsv dna. nih-3t3 cells were also transformable by subgenomic fragments of rsv dna, synthesized in vitro or generated by restriction endonuclease digestion of intracellular rsv dna. these cells did not contain rescuable rsv genomes but did contain rsv dna f ... | 1980 | 6253192 |
| studies on the structure and function of the avian sarcoma virus transforming-gene product. | the protein kinase activity associated with pp60src of a mutant of rsv temperature sensitive for transformation was shown to be sixfold more labile than that of its wild-type parent at 45 degrees c when pp60src's synthesized in vitro were compared. thus, a mutant that is temperature sensitive for transformation has a temperature-sensitive protein kinase activity. analysis of the levels of protein kinase activity in immunoprecipitates from cells infected with four different temperature-sensitive ... | 1980 | 6253224 |
| molecular events in cells transformed by rous sarcoma virus. | the rous sarcoma virus (rsv) transforming gene product has been identified and characterized as a phosphoprotein with a molecular weight of 60,000, denoted pp60src. partially purified pp60src displays a closely associated phosphotransferase activity with the unusual specificity of phosphorylating tyrosine residues in a variety of proteins. that the enzymatic activity observed is actually encoded by the rsv-transforming gene is indicated by the comparison of the pp60src-protein kinase isolated fr ... | 1980 | 6253501 |
| generation of nondefective rous sarcoma virus by asymmetric recombination between deletion mutants. | a replication-defective deletion mutant of prague rous sarcoma virus (rsv), which lacks functional gag, pol, and env genes, was crossed with a transformation-defective deletion mutant derived from schmidt-ruppin rsv. transformation- and replication-competent viruses were generated in the cross. characterization of one of these rescued viruses indicated that it was a nondefective recombinant containing the src gene of the replication-defective mutant plus the replicative genes of the transformati ... | 1980 | 6253679 |
| nucleolar ultrastructure and transcription of preribosomal rna in rous sarcoma virus-transformed chick embryo fibroblasts treated with alpha-amanitin. | uninfected and rous sarcoma virus (rsv)-transformed chick embryo fibroblasts (cef) were exposed to various concentrations of alpha-amanitin for different lengths of time. at a concentration of 4 micrograms alpha-amanitin/ml, rsv-transformed cells were shown to maintain a normal rate of transcription of all classes of rna, whereas in uninfected cells transcription was reduced to a very low level. these observations cannot be accounted for by a difference in the penetration rate of alpha-amanitin ... | 1980 | 6253713 |
| specific dephosphorylation of membrane proteins in rous sarcoma virus-transformed chick embryo fibroblasts. | chick embryo fibroblasts (cef) infected with avian sarcoma virus become rapidly transformed as a result of expression of the viral src gene in the form of a single polypeptide of molecular weight 60,000 (pp60src) with protein kinase activity and suggested preferential association with the plasma membrane. studies with normal avian and mammalian cells have revealed the presence of an antigenically related protein which seems to have similar kinase activity, but which is present at less than 1% of ... | 1980 | 6253800 |
| unifected avian cells contain structurally unrelated progenitors of viral sarcoma genes. | a single gene, src of rous sarcoma virus (rsv) coding for a protein of pp60src, is responsible for the transformation of fibroblasts. dna sequences homologous to src (the endogenous sarc) are presented in uninfected cells of chickens and other vertebrates. endogenous nucleotide sequences have also been found in the putative transforming genes of mc29 (ref. 6) and avian erythroblastosis virus. these viruses, however, induce different spectra of tumours in animals. from analysis of a new avian sar ... | 1980 | 6253807 |
| studies on recombination in heterologous crosses of rous sarcoma virus. | ts mutants in src from the prague and schmidt-ruppin strains of rous sarcoma virus (rsv) were used to superinfect chicken and quail cells chronically infected with the bryan strain of rsv. no wild-type recombinants and few double-defective virions were produced. these results indicate that genetic recombination does not occur with high frequency in these heterologous crosses even if all infectious virus is derived from doubly infected cells. | 1980 | 6255082 |
| stimulation of growth rate of chondrocytes by rous sarcoma virus is not coordinated with other expressions of the src gene phenotype. | infection and transformation of chondrocytes by rous sarcoma viruses (rsvs) (schmidt-ruppin, prague) stimulated the rate of cell growth. in contrast, several transformation-defective (td) mutants (tdpra, tdny105, tdny106, tdny107, and tdny108) retaining various sizes of the src gene did not stimulate cell growth, indicating that the stimulation of growth of chondrocytes is due to the function of the src gene. with the use of various t (transformation)-class temperature-sensitive (ts) mutants of ... | 1980 | 6255190 |
| synthesis and processing of viral glycoproteins in two nonconditional mutants of rous sarcoma virus. | we have studied the pattern of glycoprotein synthesis in two nonconditional mutants of rous sarcoma virus. one mutant, se33, produces no viral particles but synthesizes pr92env, which is cleaved intracellularly to mature glycoproteins. the second mutant, se521, encodes a gpr92env which is not cleaved to gp85 or gp37 and therefore produces virions with the phenotype of bryan rsv(-) or ny8. neither of these mutants have detectable genomic deletions. the study of these mutants has led to the follow ... | 1980 | 6255212 |
| analysis of the secondary and tertiary structures of rous sarcoma virus rna. | the secondary and tertiary structures of the 35s rna of rous sarcoma virus have been investigated. t1 rnase partial digests have been first resolved into their components by gel electrophoresis under non denaturing conditions and then each component analyzed further by various techniques. more than one hundred structured fragments have thus been isolated and shown to consist of several individual nucleotide sequences located far apart on the genome. on the basis of the results, a cloverleaf mode ... | 1980 | 6255413 |
| a survey of virus infections of the respiratory tract of cattle and their association with disease. | a total of 1590 caves were investigated between may 1972 and december 1975. twenty-two per cent were treated for respiratory disease and 2 . 5% died of pneumonia. almost 80% of the respiratory illness occurred in six sharp outbreaks. samples of virology were collected routinely from 127 healthy calves and from 354 calves treated for respiratory signs and comprised 1143 nasopharyngeal swabs and 1069 sera. virus infections were detected on 540 occasions including 135 by parainfluenzavirus type 3 ( ... | 1980 | 6256435 |
| role of src gene in growth regulation of rous sarcoma virus-infected chicken embryo fibroblasts. | we report here a study of the mechanisms leading to loss of growth control in chicken embryo fibroblasts transformed by rous sarcoma virus (rsv). we have been particularly concerned with the role of the src gene in this process, and have used rsv mutants temperature sensitive (ts) for transformation to investigate the nature of the growth regulatory lesion. the two principal findings were (1) the stationary phase of the cell cycle (g1) in chick embryo fibroblasts seems to have two distinct regul ... | 1980 | 6256641 |
| replication of transformation-defective mutants of the prague strain of rous sarcoma virus and isolation of a td mutant from duck-adapted pr-rsv-c. | the replication of transformation-defective mutants of the prague strain of rous sarcoma virus subgroup c was studied using roller cultures. under such conditions, 10(5)--10(6) infectous units of virus per 0.2 ml were produced, as revealed in both the reverse transcriptase and 16q complementation tests. a new td dapr-rsv-c mutant was isolated from duck-adapted pr-rsv-c. this mutant replicated in roller cultures with equal efficiency as the original td pr-rsv-c. it was verified that td dapr-rsv-c ... | 1980 | 6153995 |
| target antigens for antibodies and complement at the cell surface of rsv-transformed fibroblasts. | using cells transformed by rous sarcoma virus (rsv), an rna tumour virus whose genetic and structural composition is fully known, the virus-induced surface antigens acting as targets for antibodies and complement were studied. among the virus structural proteins, only the envelope antigen gp85, but not the core group-specific proteins or reverse transcriptase, were able to mediate immune lysis in the 51cr-release assay. the group-specific antigenic determinants of gp85 were predominantly involve ... | 1980 | 6155325 |
| interaction between cellular and viral genes in the expression of the rsv-induced transformation-specific cell-surface antigen vcsa. | transformation of bhk hamster fibroblasts by an env- strain of rous sarcoma virus (rsv) leads to the appearance at the cell surface of a virus-induced nonvirion antigen (vcsa), specific for transformation, whose expression is controlled by the transforming src gene. previous work has shown that a rabbit anti-vcsa serum lyses specifically, in the presence of complement, 51cr-labelled rsv-transformed cells from different animal species. now, by competition experiments with a panel of different unl ... | 1980 | 6156133 |
| transformation by rous sarcoma virus: a cellular substrate for transformation-specific protein phosphorylation contains phosphotyrosine. | transformation of chicken embryo fibroblasts by rous sarcoma virus (rsv) is caused by a single viral gene, src, which encodes a phosphoprotein, pp60src, with the enzymatic activity of a protein kinase. the relative abundance of a 36,000 molecular weight (36k) phosphorylated polypeptide which can be detected by two-dimensional electrophoresis of 32p-labeled phosphoproteins is greatly increased in rsv-transformed fibroblasts. we have reported previously that phosphorylation of the 36k polypeptide ... | 1980 | 6159984 |
| immunoelectron microscopic localization of rous sarcoma virus structural protein p27 in infected chicken embryo fibroblasts. | the immunoperoxidase technique was employed to localize, at the ultrastructural level, protein pr76 (a precursor of the 'gag' gene protein of avian leukemia and sarcoma viruses) in chick embryo cells infected with rsv-rav-2 virus. the protein was confined to free and membrane-bound ribosomes. this was often particularly conspicuous in the perinuclear region. no staining was found in the ergastoplasmic cisternae, in the golgi apparatus, or in the nucleus. this pattern of localization is compatibl ... | 1980 | 6265399 |