Publications

effect of respiratory syncytial virus infection on the uptake of and immune response to other inhaled antigens.	groups of balb/c mice were sham infected or inoculated intranasally (in) with live rsv. from day 4 to 8 after infection, the animals were exposed in to ovalbumin (ova) with or without alum adjuvant. at different intervals, levels of ova concentration in serum, igg-anti-ova antibody activity in serum, and iga-anti-ova antibody activity in bronchial washings were determined, employing the elisa technique. ige-anti-ova antibody titers in serum and bronchial washings were assessed by pca. ova concen ...	1988	3375265
electron microscopic evidence for bridges between bovine respiratory syncytial virus particles.	electron microscopic examination of ultrathin sections of a continuous cell line of ovine kidney (ok) origin, infected by bovine respiratory syncytial virus (brsv), revealed the presence of well defined bridges between virus particles. this is the first report of this novel structure. observation of ultrathin sections of human rsv long strain also grown on ok cells did not show inter-particle bridges and therefore suggested that this structure could be specific to brsv. the biological significan ...	1988	3385409
risk of secondary bacterial infection in infants hospitalized with respiratory syncytial viral infection.	because infants hospitalized with respiratory syncytial virus (rsv) infection frequently receive antibiotics, our study was undertaken to determine what the actual risk of secondary bacterial infections in patients with rsv infection is and what effect antibiotic treatment might have on the course of illness. in a 9-year prospective study of 1706 children hospitalized with acute respiratory illnesses, 565 children had documented rsv infections. a subsequent bacterial infection rarely developed i ...	1988	3397789
selective activation of transcription by a novel ccaat binding factor.	a novel ccaat binding factor (cbf) composed of two different subunits has been extensively purified from rat liver. both subunits are needed for specific binding to dna. addition of this purified protein to nuclear extracts of nih 3t3 fibroblasts stimulates transcription from several promoters including the alpha 2(i) collagen, the alpha 1(i) collagen, the rous sarcoma virus long terminal repeat (rsv-ltr), and the adenovirus major late promoter. point mutations in the ccaat motif that show eithe ...	1988	3399893
[virus replication in a culture of smooth muscle cells from the human aorta].	a new modification of the method for cultivation of cells from blood vessel explants has been proposed, and on its basis several cell lines from different vessels of human embryo and adult subjects have been derived. the sensitivity of vessel cells to viruses was studied on a model of aorta cell culture using a wide spectrum of rna and dna viruses. all the strains under study with the exception of respiratory-syncytial virus (rsv) and encephalomyocarditis (emc) virus induced a productive infecti ...	1988	3414071
[anti-tumor effect of hyperthermia plus hematoporphyrin derivative on malignant brain tumor].	photoradiation therapy using the photosensitizing agent, hematoporphyrin derivative (hpd), and laser light has been currently employed as a new modality for the treatment of cancer. at present, however, the application of this therapy is limited to superficial tumors because of difficulties in achieving light penetration, whereas 13.56 mhz radiofrequency (rf) used in hyperthermia is capable to penetrate into deeper regions and elevate the temperature of brain tumors. in the present studies, the ...	1988	3415865
identification of sequences in the long terminal repeat of avian sarcoma virus required for efficient transcription.	two different vectors, ltr-neo-ltr and ltr-cat-ltr, were constructed and deletions were introduced in the upstream ltr at -299 and at -140. these deletion mutants were introduced into qt6 cells under transient expression conditions, and the levels of transcription were monitored by dot blot hybridization or by cat assays. the results indicate that the nucleotides between -208 and -201 and between -141 and -119 in the u3 region of rsv ltr are required for efficient transcription.	1988	2827383
pyruvate kinase type m2 is phosphorylated at tyrosine residues in cells transformed by rous sarcoma virus.	chicken embryo cells (cecs) contain pyruvate kinase (pk) type m2 (m2-pk). transformation of cecs by rous sarcoma virus (rsv) leads to a reduction in the affinity of pk for the substrate phosphoenolpyruvate. in vitro, m2-pk can be phosphorylated at tyrosine residues by pp60v-src, the transforming protein of rsv. to study tyrosine phosphorylation of m2-pk in intact rsv-transformed cells, the protein was immunoprecipitated from 32p-labeled normal and rsv-sr-a-transformed cecs. phosphoamino acid ana ...	1988	2462512
most of the substrates of oncogenic viral tyrosine protein kinases can be phosphorylated by cellular tyrosine protein kinases in normal cells.	the cellular transformation induced by viral tyrosine protein kinases may result from the excessive phosphorylation of the normal polypeptide substrates of endogenous cellular tyrosine kinases, from the phosphorylation of proteins that are not normal substrates of cellular tyrosine protein kinases in uninfected cells, or from the phosphorylation of proteins of each type. to differentiate between these possibilities, antibodies to phosphotyrosine were used with immunoblotting to compare the subst ...	1988	2465525
participation of cytoskeletal intermediate filaments in the infectious cycle of human respiratory syncytial virus (rsv).	rsv infection of hep-2 or hela cells leads to biochemical and morphological changes of cytoskeletal intermediate filaments (if). thus, human cytokeratin 18 is modified to generate a more acidic polypeptide of slightly larger apparent molecular weight. in addition, the amounts of vimentin and other cytokeratins are reduced, probably as a consequence of proteolytic degradation. these changes are reflected in a decrease of immunofluorescence with specific antibodies in rsv-induced syncytia and a mo ...	1988	2837016
live viral vaccines for respiratory and enteric tract diseases.	in its programme for accelerated development of vaccines for viral respiratory and enteric tract diseases the who has assigned a very high priority to respiratory syncytial virus (rsv), parainfluenza viruses and rotaviruses. there is also some interest in alternative approaches to immunization against influenza viruses because of the failure of inactivated vaccines to provide complete and reasonably durable immunity. current attempts to develop satisfactorily attenuated viruses for use in preven ...	1988	2838984
viral products in cells infected with vesicular stomatitis virus and superinfected with rous sarcoma virus.	in cells infected with vesicular stomatitis virus (vsv) ts 1026 and superinfected with rous sarcoma virus (rsv) synthesis of vsrc mrna and rsv env mrna decreases. in these cells post-translational processing of rsv precursor proteins is impaired and small amounts of vsv antigens are detected.	1988	2839128
simultaneous infection with respiratory syncytial virus and other respiratory pathogens.	the presentation and subsequent course of respiratory syncytial virus (rsv) bronchiolitis may be atypical and unusually severe when simultaneous infection due to other pathogenic agents is present. during the past two years, nine of the 189 pediatric patients hospitalized with documented rsv infection were found to have the following simultaneous isolates from initial respiratory tract specimens: four adenovirus, four pneumococcus, one cytomegalovirus, and one pneumocystis carinii. noted complic ...	1988	2839976
mycoplasma pneumoniae and other pathogens in the aetiology of lower respiratory tract infections among japanese children.	the causes of lower respiratory tract infections in 1544 children attending a japanese hospital over a period of 7 years were investigated. both cultivation and two serological techniques were used to detect mycoplasma pneumoniae whereas viral involvement was investigated only by serology. pathogens were identified in 52% of 1175 patients with pneumonia and 36% of 369 patients without pneumonia. mycoplasma pneumoniae infection was specifically diagnosed in 414 (26.8%) of the 1544 patients. respi ...	1988	2840466
transcription of proto-oncogenes in rous sarcoma virus infected and transformed chicken embryo cells.	to evaluate an effect of infection by rsv on the transcriptional activity of proto-oncogenes, we tested 19 cellular oncogenes and the beta-actin gene performing "nuclear run on transcription assays" using nuclei isolated from rsv infected or transformed chick embryo cells (cec). a drastic increase in the transcriptional activity of the c-fgr proto-oncogene and a slight increase of c-fos and c-myc could be observed in uninfected compared to rsv infected cec. to distinguish between infection- and ...	1988	2840872
determination of the mutation rate of a retrovirus.	the mutation rate of rous sarcoma virus (rsv) was measured. progeny descended from a single virion were collected after one replication cycle, and seven regions of the genome were analyzed for mutations by denaturing-gradient gel electrophoresis. in all, 65,250 nucleotides were screened, yielding nine mutations, and the rsv mutation rate was calculated as 1.4 x 10(-4) mutations per nucleotide per replication cycle. these results indicate that rsv is an extremely mutable virus. we speculate that ...	1988	2841464
78-kilodalton glucose-regulated protein is induced in rous sarcoma virus-transformed cells independently of glucose deprivation.	to identify mrnas with altered expression in rous sarcoma virus (rsv)-transformed cells, we screened a chicken embryo fibroblast (cef) cdna library by differential hybridization. one clone, designated r1h, showed markedly elevated mrna expression in rsv-transformed cells. nucleotide sequence analysis indicated that r1h mrna encodes 78-kilodalton glucose-regulated protein (grp78). chicken grp78 was found to be very highly conserved in comparison with rat grp78 (96% identity between chicken and ra ...	1988	2841586
transfer and expression of the bacterial npt-ii gene in chick embryos using a schmidt-ruppin retrovirus vector.	in an effort to introduce foreign genes into chickens, the bacterial neomycin phosphotransferase (npt-ii) gene was cloned into an infectious avian retroviral vector derived from the schmidt-ruppin a strain of rsv. the npt-ii gene was stable in the vector during passage in vitro and infected cells were resistant to g418. fertilized chicken embryos were inoculated with the recombinant virus on day 0 and screened on day 20 for the npt-ii gene in blood cell dna. approximately 12% of the embryos were ...	1988	2842731
contribution of rhinoviruses to respiratory viral infections in childhood: a prospective study in a mainly hospitalized infant population.	a prospective study was carried out to investigate the contribution of rhinoviruses to respiratory viral infections in children and to investigate the influence of age, passive smoking, and educational level of the head of the family on the clinical course of viral respiratory disease. nasopharyngeal aspirates from 519 infants (90.8% inpatients, 9.2% outpatients) were screened for the presence of rhinoviruses, respiratory syncytial virus (rsv), adenoviruses, parainfluenza virus types 1, 2, 3, in ...	1988	2844986
current approaches to the development of vaccines effective against parainfluenza and respiratory syncytial viruses.	vaccines against parainfluenza (piv) and respiratory syncytial viruses (rsv) that are currently being developed include both live and subunit vaccines. candidate live piv vaccines that have been found to be attenuated and efficacious in rodents or primate models are (1) cold-adapted, temperature-sensitive mutants of piv-type 3 that have been serially passaged at low temperature (20 degrees c) in simian kidney tissue culture; (2) protease-activation mutants (piv-1-sendai), which have mutations th ...	1988	2845680
signals for ribosomal frameshifting in the rous sarcoma virus gag-pol region.	the gag-pol protein of rous sarcoma virus (rsv), the precursor to the enzymes responsible for reverse transcription and integration, is expressed from two genes that lie in different translational reading frames by ribosomal frameshifting. here, we localize the site of frameshifting and show that the frameshifting reaction is mediated by slippage of two adjacent trnas by a single nucleotide in the 5' direction. the gag terminator, which immediately follows the frameshift site, is not required fo ...	1988	2846182
resistance of chickens to rous sarcoma virus challenge following immunization with a recombinant avian leukosis virus.	an attenuated recombinant avian leukosis virus (alv) produced by recombinant dna techniques was examined for its ability to provide resistance to rous sarcoma virus (rsv) challenge. specific-pathogen-free chicken embryos (18-day incubation) and hatched chicks inoculated with recombinant alv produced significantly smaller tumors than sham-inoculated controls upon challenge with rsv 2 weeks postinoculation; inoculation with rav-1 produced similar results. specific-pathogen-free hens inoculated wit ...	1988	2848482
the introduction of biologically active foreign genes into human respiratory epithelial cells using electroporation.	a simple method for introducing genes into respiratory epithelial cells would assist molecular studies of a variety of pulmonary disorders. several different techniques for introducing foreign dna into cells have been described but have either not been useful for respiratory epithelial cells or are difficult and cumbersome to perform. electroporation is a simple technique that consists of exposing a cell-dna suspension to an electric shock. although it has been used to introduce genes into a var ...	1988	2849346
an analysis of the response of recombinant congenic lines of chickens to rsv challenge provides evidence for further complexity of the genetic structure of the chicken mhc (b).	we found that cb (b12/b12) and cb.r1 (b12r1/b12r1) congenic chicken lines differing from each other only in the b-g region of the mhc(b), although both of them could be characterized as regressors of rous sarcomas induced by pr-c and bh-c, are distinguishable in their response to the challenge with these two viruses by means of some parameters of tumour growth. this points further to the concept of functional and structural complexity of the b-g region. both cb and cb.r1 lines are highly suscept ...	1988	2849569
anti-rous sarcoma response of major histocompatibility (b) complex haplotypes b23, b24 and b30.	responses to rous sarcoma virus (rsv) induced tumours were studied in unh 105, a non-inbred line of new hampshire chickens. six single male matings encompassing a total of 50 dams produced 345 progeny which segregated for b complex genotypes b23/b23, b23/b24, b23/b30, b24/b24, b24/b30 and b30/b30. six-week-old chicks were wingweb inoculated with a pseudotype of bryan high titre rous sarcoma virus, bh rsv (rav-1). tumours were scored for size six times over a 10-week period post-inoculation. each ...	1988	2849889
tsh stimulates the activity of the c-fos promoter in frtl5 rat thyroid cells.	c-fos promoter activity was examined in frtl5 rat thyroid cells transiently transfected with a chimeric gene containing the c-fos promoter region linked upstream of the receptor gene chloroamphenicol acetyl transferase (cat). thyroid-stimulating hormone (tsh) stimulation of transfected cells increased cat activity 2- to 3-fold. tsh did not stimulate cat activity driven by the rous sarcoma virus (rsv) promoter. both forskolin and 8-br-cyclic amp also stimulated cat activity, and were not additive ...	1988	2850250
peptides as potential virus inhibitors. synthesis and bioassay of five respiratory syncytial virus peptide analogs with antimeasles activity.	five carbobenzoxylated and d-amino acid containing-peptide analogs of the respiratory syncytial virus (rsv) f1 glycoprotein amino terminus were chemically synthesized by solution and fmoc-solid phase peptide synthesis methods. several of these peptides, ranging from 3 to 6 residues in length, raised the bilayer to hexagonal phase transition temperature of dielaidoylphosphatidylethanolamine. none of these peptides were specific inhibitors of rsv or herpes simplex virus infection. two of the serie ...	1988	2850279
regulation of rous sarcoma virus rna splicing and stability.	only a fraction of retroviral primary transcripts are spliced to subgenomic mrnas; the unspliced transcripts are transported to the cytoplasm for packaging into virions and for translation of the gag and pol genes. we identified cis-acting sequences within the gag gene of rous sarcoma virus (rsv) which negatively regulate splicing in vivo. mutations were generated downstream of the splice donor (base 397) in the intron of a proviral clone of rsv. deletion of bases 708 to 800 or 874 to 987 result ...	1988	2850470
high chemotactic motility and growth in hard agar of a variant of rsv-transformed fibroblasts are lost in late passages.	cloning efficiency in hard agar (0.6%) and high chemotactic migration toward fibroblast conditioned medium have been shown to characterize metastatic tumor cells. we studied growth in 0.6% agar and chemotaxis of two lines of rous sarcoma virus-transformed balb/c3t3 cells, b77/3t3 (low metastatic) and aa12 (high metastatic), and compared them to their non-transformed counterpart, in order to verify whether these properties were maintained during several subcultivations. cells were cryopreserved a ...	1988	2832985
mechanism of target cell lysis by cytotoxic t lymphocytes (ctl) employing rsv-induced h-2 congenic and recombinant mouse tumor cells: demonstration of soluble mediators released from h-2-restricted ctl clones.	the secretion and the specificity of cytotoxic mediators from h-2-restricted cytotoxic t lymphocytes (ctl) were examined using non-virus-producing target tumor cells induced by the schmidt-ruppin strain of rous sarcoma virus (sr-rsv) in b10 congenic and recombinant mice. by using rat concanavalin a supernatant, two h-2-restricted ctl clones were established from cytotoxic effector cells of b10.a(5r) mice primed with sr-rsv-induced syngeneic tumor cell-free supernatants from the h-2-restricted ct ...	1988	2833355
evidence for positive and negative regulation in the promoter of the chicken delta 1-crystallin gene.	we investigated the role of sequences flanking the transcription initiation site of the delta 1-crystallin gene in transient transfection assays of primary embryonic chicken lens epithelial cells or fibroblasts. varying lengths of the 5' flanking sequence of the delta 1-crystallin gene (containing some untranslated sequence from exon 1) were fused to the bacterial chloramphenicol acetyltransferase (cat) gene in the psvocat plasmid. a plasmid carrying the bacterial beta-galactosidase gene driven ...	1988	2834246
detection of respiratory syncytial virus and rotavirus by enhanced chemiluminescence enzyme-linked immunosorbent assay.	the horseradish peroxidase-catalyzed oxidation of luminol was used in a chemiluminescence avidin-biotin enzyme-linked immunosorbent assay (cl-abe) to detect respiratory syncytial virus (rsv) and rotavirus (rov). this cl-abe was carried out in a new apparatus constructed for the photographic registration of the light emission produced. when measured in a spectrophotometer, the light emission produced by the oxidation of luminol showed a peak emission at 425 nm. the chemiluminescence output reache ...	1988	2835387
prenatal lethality in a transgenic mouse line is the result of a chromosomal translocation.	we have produced a line of transgenic mice that is characterized by prenatal lethality. these mice bear a chimeric plasmid containing the long terminal repeat of the rous sarcoma virus linked to the coding region of the chloramphenicol acetyltransferase gene (prsv-cat). mice heterozygous for the prsv-cat integration site are semisterile, producing litters approximately equal to 40% of the average size when crossed to normal mice. approximately 50% of the progeny from such a cross bear the prsv-c ...	1988	2829218
brdu-induced changes in the provirus of pr-rsv in mammalian cells.	previously we demonstrated differences in the organization and methylation pattern of integrated rous sarcoma proviral sequences in helper-dependent virogenic rat twerc cells. in the present study we attempted to induce changes in the integrated viral genome of twerc cells using 5-bromodeoxyuridine (brdu). four clones (a, b, c, and f) derived from the parental cell line were treated for 10 months with different concentrations of brdu. restriction enzyme analysis of the parental cell line and its ...	1988	2851743
antigen detection in the diagnosis of viral infections.	the value of viral antigen detection from nasopharyngeal secretion (nps) by enzyme immunoassay (eia) in everyday clinical practice was evaluated in 570 children hospitalized because of infections. nps-eia gave a positive result in 32% of all cases. virus isolation was positive in the nps in 25%, virus isolation in stool samples in 14%, and virus serology in 28% of the cases. nps-eia was superior for detecting adenovirus, respiratory syncytial (rs) and parainfluenza viruses. in a series of 124 pa ...	1988	2851878
respiratory syncytial virus outbreak on american samoa. evaluation of risk factors.	acute respiratory illness is one of the leading causes of childhood mortality in developing nations. we investigated an increase in hospitalizations of children less than 2 years old for severe lower respiratory tract illness (lri) from october 1986 through december 1986 on the island of american samoa. hospitalization rates were highest in children less than 6 months of age (60 of 1000 compared with 22 of 1000 for those 6 to 11 months of age, and seven of 1000 for those 12 to 24 months of age). ...	1989	2916509
a concurrent epidemic of respiratory syncytial virus and echovirus 7 infections in an intensive care nursery.	we describe concurrent outbreaks of respiratory syncytial virus (rsv) and echovirus 7 (echo 7) infections in a neonatal intensive care unit, including infants who had dual infections. seventy-three infants were identified as having rsv from january through june, 1984. during the same surveillance period echo 7 was cultured from 20 infants, and 6 infants had concurrent rsv and echo 7 and rsv were isolated, but not concurrently. this dual outbreak of rsv and echo 7 infections persisted for months ...	1989	2922234
effect of breast feeding on the development of anti-idiotype antibody response to f glycoprotein of respiratory syncytial virus in infant mice after post-partum maternal immunization.	groups of lactating balb/c mice were immunized in the immediate postpartum period with high doses of mab (ab-1) to the f-glycoprotein (f-gp) of respiratory syncytial virus (rsv). this antibody possessed neutralizing activity against the whole virus. the immune response to f-gp was studied in the breast feeding infant mice of such mothers at regular intervals before and after weaning. all infant mice exhibited anti-f-gp activity in serum, which was detected until 6 wk of age. splenic cells of suc ...	1989	2926142
host cell reactivation of cat-expression vectors as a method to assay for cloned dna-repair genes.	we demonstrate the feasibility of using passive host-cell reactivation of a shuttle-vector prsvcat to detect cloned dna-repair genes. as models, a transient expression vector, prsvdenv, and a positive-selection vector, prsvdenv/svgpt, were constructed containing the t4 coliphage denv gene, coding for an ultraviolet-specific endonuclease, under promotion of the rous sarcoma virus (rsv) long-terminal repeat. cotransfection of one or three copies of prsvdenv per uv-irradiated prsvcat molecule into ...	1989	2927423
antigenic variation of human rsv strains isolated in japan.	antigenic variations of respiratory syncytial virus (rsv) strains were analyzed using a collection of nine, seven, two, and one monoclonal antibodies (mabs), respectively, raised against the fusion protein (f), large glycoprotein (g), nucleoprotein (np), and phosphoprotein (p) components of the long strain of rsv. competitive binding assay by these mabs demonstrated eight, four, and two distinct epitopes on f, g, and np components, respectively. comparison of prototype long with ten field strain ...	1989	2466102
integrins isolated from rous sarcoma virus-transformed chicken embryo fibroblasts.	avian integrins are a complex of three integral membrane glycoproteins that are thought to have a role both in anchoring the cytoskeleton to the plasma membrane and establishing linkages to the extracellular matrix. we previously demonstrated that bands 2 and 3 of integrin are phosphorylated on both tyrosine and serine residues in chicken embryo fibroblasts (cef) transformed with rous sarcoma virus (rsv) and other oncogenic retroviruses. the effects of rsv transformation on integrins from chick ...	1989	2468126
[biochemical characterization of tumor rejection antigen (tra) and genetic control in anti-tra immune responses].	a tumor antigen capable of inducing tumor resistance (tumor rejection antigen; tra) was obtained in a solubilized form by sodium dodecyl sulfate (sds)-extraction of plasma membrane fraction from rous sarcoma virus (rsv)-induced csa1m fibrosarcoma cells (balb/c origin). analyses by sephacryl s-300 gel filtration and sds-polyacrylamide gel electrophoresis revealed that tra activity was recovered in the fraction of an approximate molecular weight (m. w.) of 60kd. such tra was also found to exist in ...	1989	2468311
neutralization epitopes of the f glycoprotein of respiratory syncytial virus: effect of mutation upon fusion function.	eighteen neutralizing monoclonal antibodies (mabs) specific for the fusion glycoprotein of the a2 strain of respiratory syncytial virus (rsv) were used to construct a detailed topological and operational map of epitopes involved in neutralization and fusion. competitive binding assays identified three nonoverlapping antigenic sites (a, b, and c) and one bridge site (ab). thirteen mab-resistant mutants (marms) were selected, and the neutralization patterns of the mabs with either marms or rsv cli ...	1989	2470922
recognition of respiratory syncytial virus fusion protein by mouse cytotoxic t cell clones and a human cytotoxic t cell line.	two mouse cytotoxic t cell (tc) clones, d5 and h11a, with specificity for the respiratory syncytial virus (rsv) fusion protein (f) were derived from balb/c mice primed intranasally (i.n.) with rsv (a2 strain). these clones possessed essentially the same characteristics, and only clone h11a is described here. tc clone h11a lysed target cells infected with a recombinant vaccinia virus (vv) expressing the rsv f gene, and similar target cells infected with rsv strains long, 8/60, or 18537. in additi ...	1989	2471784
novel tyrosine kinase substrates from rous sarcoma virus-transformed cells are present in the membrane skeleton.	we have previously reported the production of monoclonal antibodies directed against phosphotyrosine, which is the modification induced by many oncogene products and growth factor receptors. one of these antiphosphotyrosine antibodies (py20) was used in affinity chromatography to isolate phosphotyrosine (py)-containing proteins from rous sarcoma virus-transformed chick embryo fibroblasts (rsv-cefs). mice were immunized with these py-proteins for the production of monoclonal antibodies to individ ...	1989	2472406
[transcription and expression in escherichia coli of src gene cloned sequences of rous sarcoma virus].	effective transcription of virus-specific sequences was shown in escherichia coli cells that carry recombinant plasmids pprc11 and psrcc with fragments of the rous sarcoma virus (rsv) genome. analysis of transcripts revealed several classes of rna, one of which is probably transcribed from the structural part of the rsv src gene. analysis of the primary structure of the region adjacent to the src rsv gene showed the existence of sequences similar to the bacterial promoters from which the src-spe ...	1989	2472549
evidence that a phosphotyrosine-containing 120,000 da protein from rous sarcoma virus-infected cells is phosphorylated by pp60v-src.	phosphorylation of a phosphotyrosine-containing 120,000 da protein (pp120) in rous sarcoma virus (rsv)-infected mammalian cells and in in vitro protein kinase reactions was examined. phosphorylated pp120 was co-immunoprecipitated with anti-pp60v-src antibodies only from rsv-transformed or revertant vole fibroblasts which contained active pp60v-src tyrosine kinase activity or from temperature-sensitive rsv-infected vole cells grown at the permissive temperature. pp120 was phosphorylated on tyrosi ...	1989	2472591
two interferon sensitive steps in the replication cycle of rous sarcoma virus.	de novo infection of rous sarcoma virus (rsv) strains of receptor subgroups a, b, c, and d is inhibited by low doses of chick interferon. adsorption and penetration into the cell are not marginally impaired by interferon treatment. since the level of proviral dna synthesis is strongly reduced in the interferon-treated cell it is concluded that uncoating or reverse transcription of the viral genome is inhibited. this inhibition of proviral dna synthesis is not caused by an arrest of cef in the st ...	1989	2474893
respiratory syncytial virus infection of human cord and adult blood monocytes and alveolar macrophages.	we studied the permissiveness of human leukocytes, blood monocytes, alveolar macrophages, and cord blood monocytes to infection with respiratory syncytial virus (rsv). specific immunofluorescence was used to determine the percentage of infected leukocytes. the results indicated that monocytes were the most susceptible human leukocyte to in vitro infection with rsv. polymorphonuclear leukocytes demonstrated no specific fluorescent staining after 24 h of exposure to rsv, whereas peripheral blood n ...	1989	2476959
hiv promoter activity in primary antigen-specific human t lymphocytes.	human retroviruses, such as the hiv, infects human t cells, and efficient hiv replication occurs primarily in activated t cells rather than resting cells. increased hiv production is likely caused by the activation of the retroviral promoter, and the hiv promoter may be regulated by intracellular signals induced during immune stimulation. to examine the regulation of retroviral promoter activity in normal, ag-specific primary t lymphoblasts, a heterogeneous population of primary human t cells wa ...	1989	2477457
characterization of a novel human respiratory syncytial virus chimeric fg glycoprotein expressed using a baculovirus vector.	human respiratory syncytial virus (rsv) codes for two glycoproteins (f and g) which have been shown to the major targets for the host antibody response. we have expressed a novel chimeric glycoprotein (fg) in insect cells using a baculovirus vector. the chimeric glycoprotein contains the signal and extracellular regions of the rsv f glycoprotein linked to the extracellular region of the rsv g glycoprotein. beginning at the amino terminus, the chimeric glycoprotein consists of amino acids 1 to 48 ...	1989	2477497
biological and biochemical properties of the c-src+ gene product overexpressed in chicken embryo fibroblasts.	the c-src protein isolated from neuronal cells (pp60c-src+) displays a higher level of protein kinase activity than does pp60c-src from nonneural tissues. there are two structural alterations present in the amino-terminal half of pp60c-src+ expressed in neurons which could contribute to the enhanced activity of this form of pp60c-src: (i) a hexapeptide insert located at amino acid 114 of avian pp60c-src+ and (ii) a novel site(s) of serine phosphorylation. we characterized pp60c-src+ expressed in ...	1989	2477684
comparison of antigenic sites of subtype-specific respiratory syncytial virus attachment proteins.	a panel of 19 monoclonal antibodies (mabs) were used to probe the antigenic relationships between the g (attachment) proteins of a and b respiratory syncytial virus (rsv) subtypes (ga and gb). at least three and two antigenic sites were present on ga and gb, respectively, including a shared neutralizing site. most of the antibodies had some degree of complement-independent neutralizing capacity, but in common was a large neutralization-resistant fraction of virus (range 13 to 78%). passive admin ...	1989	2479715
[a stat-method of determining respiratory syncytial virus].	for rapid detection of rs virus we have modified agglutination test with staphylococcus coated with rsv-antibody which allows the virus titer to be determined within 3-5 min. the results of rs virus titration in the yield compared with those obtained by cft and cpe tests showed our modified test to be twice as specific and sensitive (60-80 ng/ml). this modification of the coagglutination test with sensitized staphylococcus and the method of running the test on a row of slides may be used in viro ...	1989	2480026
early identification and retrieval or deletion of human lymphocyte subpopulations responding to influenza virus or respiratory syncytial virus challenge.	differences in immune responses of human mononuclear leukocytes (mnl) have been demonstrated following exposure in vitro to influenza virus or respiratory syncytial virus (rsv). in the current studies, we sought to identify early differences in reactive subpopulations that emerge from within the heterogeneous resting mnl pool after challenge. mnl were sham-exposed or exposed to influenza virus or rsv, separated, and retrieved by countercurrent centrifugal elutriation after 3 d. exposure to influ ...	1989	2480179
the tumor rejection antigen separated from rous sarcoma virus-induced murine fibrosarcoma exhibits a molecular weight of approximately 60 kd but differs from functional pp60src.	the tumor antigen capable of inducing tumor resistance (tumor rejection antigen; tra) was obtained in a solubilized form by sodium dodecyl sulfate (sds) extraction of plasma membrane fraction from rous sarcoma virus (rsv)-induced csa1m fibrosarcoma cells (balb/c origin). analyses by sephacryl s-300 gel filtration and sds-polyacrylamide gel electrophoresis revealed that tra activity was recovered in the fraction with a molecular weight of approximately 60 kd. unfractionated crude sds-solubilized ...	1989	2480944
ultrastructure and gold-immunolabelling of cell-substratum adhesions (podosomes) in rsv-transformed bhk cells.	rous sarcoma virus-transformed bhk (rsv/b4-bhk) cells develop peculiar dot-like adhesions, that have been named podosomes, which, in the presence of serum, aggregate into ring- or crescent-shaped adhesion sites, the rosettes of podosomes. we have used the lysis-squirting technique and gold-immunolabelling to study the 3d-organisation of podosomes and the location of vinculin, gelsolin, phosphotyrosine-containing proteins and pp60src at an ultrastructural level. podosomes appear to be conical bod ...	1989	2482298
major histocompatibility complex class ii (ia-like) antigens on chicken embryo fibroblasts: effect of transformation by rous sarcoma virus.	in this study, three monomorphic monoclonal antibodies to chicken mhc class ii molecules (b-l) were tested for reactivity in normal and rsv-transformed embryo fibroblasts. the immunocytochemical staining, the cell-bound elisa assay, and the immunoprecipitation analysis showed that all three antibodies reacted with the b-l (ia-like) molecules on normal cells of different genotypes. conversely, the expression of these antigens was not detected in fibroblasts cultured from feather follicles of adul ...	1989	2483835
the ltr, v-src, ltr provirus generated in the mammalian genome by src mrna reverse transcription and integration.	different types of altered proviruses of rous sarcoma virus (rsv) have been detected in mammalian tumor cell lines. we cloned and sequenced one of these altered proviruses with the structure ltr, v-src, ltr. the presence of an intact viral splice junction, as well as duplications of the chromosomal sequence gcgggg flanking the two 2-base-pair-deleted ltrs, demonstrated reverse transcription and normal retroviral integration of src mrna in mammalian cells. in addition, a 1-nucleotide deletion 2 b ...	1989	2463374
mechanism of reversion of rous sarcoma virus transformation by herbimycin a: reduction of total phosphotyrosine levels due to reduced kinase activity and increased turnover of p60v-src1.	we studied the mechanism of reversion of rous sarcoma virus (rsv)-transformation by herbimycin a in a temperature-sensitive rsv-infected nrk cell line. herbimycin reduced the total cellular phosphotyrosine level to 10% of the control value. intracellular p60src kinase activity was reduced significantly within 3 h of herbimycin treatment, but recovered to approximately 50% of the control within 24 h, and the kinetics paralleled the decrease of the phosphorylation of a cellular target p36. partial ...	1989	2463877
synergistic killing of virus-transformed human cells with interferon and n-methyl-n'-nitro-n-nitrosoguanidine.	interferons potentiate the cytotoxic effects of certain antineoplastic drugs on human tumor cells both in vitro and in vivo, although the mechanism of interferon's synergistic action is unknown. interferon may act by modulating the expression of dna repair activity in cells. to test this hypothesis, we maintained parallel cultures of normal o6-methylguanine repair-proficient human fibroblasts and tumor cells, or rsv-and sv40-transformed repair-deficient mer- human fibroblasts in medium containin ...	1989	2463881
detection of bovine respiratory syncytial virus using a heterologous antigen-capture enzyme immunoassay.	based on the marked antigenic similarities that exist between antigens of the human and bovine strains of respiratory syncytial virus (rsv), an enzyme immunoassay (eia) designed to detect human rsv was used to detect bovine rsv. the commercial test kit (rsv eia) consists of a solid phase (beads) coated with a capture antiserum prepared against the long strain of human rsv. the rsv eia test was compared with the method of inoculation of cell cultures and fluorescent antibody (fa) staining of lung ...	1989	2488346
nosocomial viral infections: recent developments and new strategies.	surveillance studies generally have underestimated the importance of viruses in the pathogenesis of nosocomial respiratory tract infections. the development of rapid, sensitive and reliable diagnostic techniques has permitted documentation of viral respiratory pathogens and has led to increased understanding of the epidemiology of these organisms in the hospital. these advances are exemplified by studies of respiratory syncytial virus infections in hospitalized children. the pulmonary sequelae o ...	1989	2495955
immunization of the gastrointestinal tract with bacterial and viral antigens: implications in mucosal immunity.	the effects of oral immunization with pseudomonas aeruginosa (paoi), chlamydia trachomatis or respiratory syncytial virus (rsv) on the development of specific antibody responses in the intestine, respiratory tract and genital secretions was studied in several animal models. oral immunization resulted in the development of specific immunity in distant mucosal sites. however, its role in influencing the outcome of reinfection challenge at the distant site varied with the antigen. little or no prot ...	1989	2499537
[clinical studies on the secondary bacterial infection in respiratory syncytial virus infection of children].	secondary bacterial infection was studied on 231 children admitted with respiratory syncytial virus (rsv) infection in the 10 years since 1987. of the 231 children, 56 (24.2%) had dual bacterial infection possibly due to secondary bacterial invasion. the diagnoses of bacterial disease were sepsis (2), pyothorax (2), pneumonias (41), otitis media (7), nasopharyngitis (2) and urinary tract infection (2). dual bacterial infections were more frequent in infants and children over 6 months than in inf ...	1989	2504838
[induction of unstable mutations in drosophila melanogaster by microinjections of dna from oncogene viruses into the embryonic polar plasm. part iv. malignantization of tissues of mutant larvae].	we have demonstrated that larval tissues of mutant stocks induced by injections of oncogene virus dna (sa7 and rsv) show the neoplastic mode of growth after transplantation into the body cavity of wild-type flies. neoplasms tested were shown to be ordinary benign insect neoplasms, and at the same time they show the dominant mode of heredity typical of the neoplasms of vertebrates. genetic factors responsible for the neoplastic growth are localised in the 3rd chromosome in the stocks obtained aft ...	1989	2509289
an experimental approach to specific adoptive immunotherapy for malignant brain tumors.	with the aid of interleukin 2 (il-2), two phenotypically different cytotoxic t lymphocyte (ctl) clones were established with target specificity against syngeneic murine malignant brain tumor (a methylcholanthrene-induce ependymoblastoma of c57bl/6 mouse origin, 203-glioma). furthermore, the cloned ctl lines were characterized in vitro, and their in vivo effectiveness was investigated by intracerebral (i.c.) tumor neutralization assay and adoptive immunotherapy with the clones for i.c. tumor-bear ...	1989	2519184
the 1b (ns2), 1c (ns1) and n proteins of human respiratory syncytial virus (rsv) of antigenic subgroups a and b: sequence conservation and divergence within rsv genomic rna.	a 2330 nucleotide sequence spanning the 1b (ns2), ic (ns1) and n genes and intergenic regions of human respiratory syncytial virus strain 18537, representing antigenic subgroup b, was determined by sequencing cloned cdnas of intracellular mrnas. comparison with the previously reported sequences for strain a2 of subgroup a showed that 1b, 1c and n were highly conserved at the nucleotide level (78, 78 and 86% identity, respectively) and at the amino acid level (92, 87 and 96% identity, respectivel ...	1989	2525176
in vitro performance of the small particle aerosol generator (spag-2).	the anti-viral drug ribavirin primarily used for the treatment of respiratory syncytial virus (rsv) infection in infants is delivered by continuous nebulization with the small particle aerosol generator (spag). clinical data suggest that the spag is an efficient nebulizer for ribavirin; it is also being used for the delivery of other pulmonary agents. the efficiency of a nebulizer can be defined in large part by delivering a major proportion of its output with a particle size of 1 to 5 microns w ...	1989	2529473
t-cells in respiratory syncytial virus (rsv) infection.		1989	2533461
a rat mutant cell clone showing temperature-dependent transformed phenotypes with functional expression of the src gene product.	the cellular mutant b814 isolated from a fischer rat cell line shows temperature-sensitivity of focus formation on infection with moloney murine sarcoma virus (mo-msv) and rous sarcoma virus (rsv). an rsv-transformed clone (s814-2) isolated from b814 cells shows temperature-sensitive transformed phenotypes for morphology, growth in soft agar, and glucose uptake. the expression, phosphorylation, and tyrosine kinase activity of pp60v-src in s814-2 were not affected at the nonpermissive temperature ...	1989	2535907
ability of mammalian fibroblasts to grow in synthetic medium containing neither serum nor exogenously added macromolecules.	rous sarcoma virus transformed chinese hamster fibroblasts, clone chr1-3, were established at high temperature, then subcloned. six subclones with round and flat morphology harboring undeleted and partially deleted rsv proviruses, respectively, were seeded into serum-free synthetic medium with no macromolecular additives, and maintained for 2 mo. one flat subclone no. 14, fully designated sfchr1-3.14 for its serum-free phenotype, was further propagated in the same medium. the cells grew exponent ...	1989	2536651
a method for infection of cultured myogenic cells with rous sarcoma virus using polybrene.	a method for efficiently infecting primary myogenic cultures with a temperature-sensitive variant of the prague strain of rous sarcoma virus (rsv, tsla24) to obtain a high yield of transformed myogenic cells is reported. it incorporates the use of an amorphous polymer of polycations, polybrene, to enhance the absorption of the virus by the muscle cells. in addition, other steps which were shown to be important were a) to allow cell attachment before infection, b) to infect at 35 degrees c in low ...	1989	2536652
crystal structure of a retroviral protease proves relationship to aspartic protease family.	retroviral gag, pol and env gene products are translated as precursor polyproteins, which are cleaved by virus-encoded proteases to produce the mature proteins found in virions. on the basis of the conserved asp-thr/ser-gly sequence at the putative protease active sites, and other biochemical evidence, retroviral proteases have been predicted to be in the family of pepsin-like aspartic proteases. it has been suggested that aspartic proteases evolved from a smaller, dimeric ancestral protein, and ...	1989	2536902
comparison of the regional distribution of calspectin (nonerythroid spectrin or fodrin), alpha-actinin, vinculin nonerythroid protein 4.1, and calpactin in normal and avian sarcoma virus- or rous sarcoma virus-induced transformed cells.	with fluorescence and interference reflection microscopy (irm), we compared the regional distribution of calspectin, its interacting proteins (nonerythroid protein 4.1 and calpactin), alpha-actinin, and vinculin in nrk cells and their avian sarcoma virus (asv)- or temperature-sensitive (ts) rous sarcoma virus (rsv)-transformed cells. the localization of these cytoskeletal proteins was determined with the specific antibodies. in nrk cells, alpha-actinin and vinculin were concentrated at adhesion ...	1989	2537219
dissociation of inositol trisphosphate from diacylglycerol production in rous sarcoma virus-transformed fibroblasts.	the metabolism of phosphatidylinositol (pi) and related intermediates was studied in uninfected and rous sarcoma virus-(rsv) infected chicken embryo fibroblasts (cefs). cells infected with wild-type rsv exhibited twofold increases in steady-state concentrations of inositol trisphosphate (ip3) and inositol bisphosphate (ip2) as compared to uninfected cefs. in addition, increased concentrations of ip3 and ip2 were observed in cefs infected with the rsv temperature-sensitive transformation mutant n ...	1989	2537320
identification of a phorbol ester-repressible v-src-inducible gene.	chicken embryo fibroblasts (cef) infected with a temperature-sensitive rous sarcoma virus (rsv) mutant, tsny72-4, express a set of pp60v-src-induced rnas soon after shift to the permissive temperature. by subtractive and differential screening, we have cloned 12 of these sequences, 2 of which were c-fos and krox-24. serum induced all the v-src-inducible genes tested, suggesting that these genes serve roles in normal cell division and are not specific to transformation per se. significantly, howe ...	1989	2537491
restricted clonality of visceral sarcomas in avian sarcoma virus-infected chickens.	experiments were undertaken to analyze proviral dna in primary (wing web) and visceral sarcomas arising in fp chickens infected with bh-rsv(rav-2). using the degree of heterogeneity of bh-rsv proviral integration sites as a measure of the degree of polyclonality of sarcoma tissue, we observed that a high proportion of the visceral sarcomas examined comprised dominant clones, independently of whether these sarcomas were isolated from immune-suppressed or nonsuppressed infected chickens; by contra ...	1989	2538025
response of major histocompatibility (b) complex haplotypes b22, b26, and b30 to rous sarcomas.	the response to rous sarcoma virus-induced tumors was measured over a 2-yr period using line unh 105 new hampshire chickens segregating for three major histocompatibility (b) complex haplotypes, b22, b26, and b30. twelve sires and 49 dams were used to produce 489 pedigreed progeny consisting of six b genotypes b22/b22, b22/b26, b22/b30, b26/b26, b26/b30, and b30/b30. six-wk-old chicks were inoculated in the wingweb with a pseudotype of bryan high-titer rous sarcoma virus designated as bh rsv (ra ...	1989	2539589
expression of a novel gene encoding a 51.5 kd precursor protein is induced by different retroviral oncogenes in quail neuroretinal cells.	a cdna clone, named t64, was isolated from a library of quail neuroretinal cells transformed by a thermosensitive v-src mutant of rous sarcoma virus. it corresponds to the most abundant mrna with thermodependent expression in these cells. t64 accumulation also correlated with pp60v-src activity in other cell types transformed by rsv, such as fibroblasts and myoblasts, but was independent of the proliferative state of the cells, indicating that t64 is rather implicated in the process of morpholog ...	1989	2541393
hiv-1 expression is posttranscriptionally repressed in drosophila cells.	the long terminal repeats (ltrs) of the human immunodeficiency virus (hiv) the rous sarcoma virus (rsv) and the copia drosophila retrotransposon were compared in their capacity to direct expression of the bacterial cat (chloramphenicol acetyltransferase) gene in human, murine, and drosophila cell lines. the results indicate that hiv and rsv ltr expression is post transcriptionally repressed in the drosophila cells while copia ltr expression is post-transcriptionally repressed in the human and mu ...	1989	2541751
efficacy of viral components of a nonabortigenic combination vaccine for prevention of respiratory and reproductive system diseases in cattle.	efficacy and safety of components of an im-administered vaccine for prevention of infectious bovine rhinotracheitis virus (ibrv), parainfluenza type-3 (pi-3) virus, bovine viral diarrhea virus (bvdv), and respiratory syncytial virus (rsv) infections and campylobacteriosis and leptospirosis were evaluated in cattle, including calves and pregnant cows. challenge of immunity tests were conducted in calves for ibrv, pi-3 virus, or bvdv vaccinal components. all inoculated calves developed serum-neutr ...	1989	2542202
suppression of rous sarcoma virus-induced tumor formation by preinfection with viruses encoding src protein with novel n termini.	two recovered avian sarcoma viruses (rasvs), rasv157 and rasv1702, encode src products which contain novel, nonmyristoylated n-terminal amino acids. these viruses transform chicken embryo fibroblasts and cause tumors in chicks. however, the tumors rasvs induce are small and regress within 2 weeks. to determine whether this regression results from weak tumorigenicity or from the active immunity of the host, we injected 1-week-old chicks with rasv and several days later injected the chicks with ch ...	1989	2542564
clinical manifestations of respiratory tract infections due to respiratory syncytial virus and rhinoviruses in hospitalized children.	from september 1984 to may 1986, nasopharyngeal secretions were obtained from 519 children with some form of respiratory tract infection. the nasal secretions were screened for respiratory syncytial virus (rsv), rhinoviruses, adenoviruses, parainfluenza virus types 1, 2, 3, influenza virus types a and b, and enteroviruses by tissue culture virus isolation technique and/or enzyme-linked immunosorbent assay. a uniform questionnaire gave information about age, sex, individual signs and symptoms, fi ...	1989	2545074
comparison of three techniques for detection of respiratory viruses in nasopharyngeal aspirates from children with lower acute respiratory infections.	a comparison of immunofluorescence (if), enzyme-linked immunosorbent assay (elisa), and isolation in tissue culture (tc) for detection of respiratory viruses was performed on 496 nasopharyngeal aspirates from children under 5 years of age with lower acute respiratory infections who were receiving attention at three hospitals in buenos aires, argentina. all samples were tested by the three methods for respiratory syncytial virus (rsv), influenza a and b, adenovirus, and parainfluenza 1 and 3. vir ...	1989	2547019
proteolytic activity of specialized surface protrusions formed at rosette contact sites of transformed cells.	surface protrusions at the leading edge of a moving cell that make contact with the surrounding extracellular matrix (ecm) are its main motor for locomotion and invasion. chicken embryonic fibroblasts transformed by rous sarcoma virus (rsv-cef) form specialized membrane rosette-shaped contact sites on planar substrata as shown by interference reflection microscopy (irm). such activity is lacking in normal cells. these rosette contacts are more labile than other adhesion sites, such as focal and ...	1989	2549171
[differences in the distribution of proviruses in low- and highly- metastatic variants of hamster cells, transformed by rous sarcoma virus].	the structure of provirus in syrian hamster cells, transformed by rous sarcoma virus (rsv) varying in metastatic capability in vivo has been analysed. the original cell line and its low metastatic variants contain only one copy of the integrated rsv genome. the dna of highly metastatic cell lines cloned from the same primary culture, contain an additional copy of provirus. this rsv copy in different highly metastatic variants has a similar integration site.	1989	2549401
thermodynamic stability and statistical significance of potential stem-loop structures situated at the frameshift sites of retroviruses.	rna stem-loop structures situated just 3' to the frameshift sites of the retroviral gag-pol or gag-pro and pro-pol regions may make important contributions to frame-shifting in retroviruses. in this study, the thermodynamic stability and statistical significance of such secondary structural features relative to others in the sequence have been assessed using a newly developed method that combines calculations of the lowest free energy of formation of rna secondary structures and the monte carlo ...	1989	2549508
creation and expression of myristylated forms of rous sarcoma virus gag protein in mammalian cells.	rous sarcoma virus (rsv), a member of the avian sarcoma and leukosis family of retroviruses, has long been known to be capable of infecting and transforming mammalian cells; however, such transformed cells do not release virus particles. the rsv gag product (pr76gag) produced in these cells is not released into the culture medium or proteolytically processed to release mature products. thus, the behavior of pr76gag in mammalian cells is much like that of mammalian retroviral gag proteins which h ...	1989	2550669
expression vector system based on the chicken beta-actin promoter directs efficient production of interleukin-5.	we examined the promoter activity of the 1.3-kb chicken beta-actin gene sequence located between the 5' flanking region and the proximal region of the second exon. this promoter region showed higher promoter activity than the simian virus 40 (sv40) early promoter or the rous sarcoma virus (rsv) long terminal repeat (ltr) as assayed by transient lacz gene expression in mouse l cells. furthermore, replacement of the 3' splice sequence in this promoter by that derived from the rabbit beta-globin ge ...	1989	2551778
effects of alterations in the leader sequence of rous sarcoma virus rna on initiation of translation.	the 372-nucleotide leader sequence of rous sarcoma virus rna contains three conserved short open reading frames and other sequences responsible for a variety of life cycle functions. we have investigated several aspects of the leader rna which may influence the translation of the major coding regions to which the leader is juxtaposed. we found that small perturbations of the leader length do not affect the binding and scanning of ribosomal subunits by more than about 10%, that the length and/or ...	1989	2552182
tpck and quercetin act synergistically with vanadate to increase protein-tyrosine phosphorylation in avian cells.	we have found four compounds that act synergistically with the phosphotyrosine phosphatase inhibitor sodium orthovanadate (na3vo4) to greatly increase the extent of protein-tyrosine phosphorylation in both uninfected chick embryo fibroblasts (cef) and their rous sarcoma virus-transformed counterparts (rsv-cef). these four inhibitors fall into two categories: the chymotrypsin-specific protease inhibitors, tosyl-phenylalanine-chloromethyl ketone (tpck) and n-carbobenzoxy-1-phenylalanine-chlorometh ...	1989	2552375
a continuous line of chicken embryo cells derived from a chondrocyte culture infected with rsv.	a continuous line of chicken embryo cells was derived from a culture of chondrocytes infected with rous sarcoma virus (rsv). these cells, designated as na101, have reduced serum requirements and are able to grow in a semisolid medium. na101 cells show the same phenotype as freshly rsv infected chondrocyte cultures, i.e. synthesis of fibronectin and type i collagen, elongated bipolar shape and absence of tumorigenicity following grafting onto the chorioallantoic membrane of embryonated duck eggs; ...	1989	2553220
inhibition of avian retrovirus protein synthesis in the presence of host cellular mrna.	two conditions of in vitro translation are described in which the rna of rous sarcoma virus is significantly less efficient at protein synthesis than host cellular chick mrna. in direct competition, addition of increasing amounts of host cell mrna inhibits synthesis of gag gene products from rsv rna. when the denaturant dimethyl sulfoxide is added to a mixture of the two rna's the inhibition is even greater. these results support the idea that protein synthesis from avian retrovirus rna is negat ...	1989	2554857
inhibition of sv40 dna replication by rous sarcoma virus ltr enhancer.	simian virus 40 (sv40) late region recombinant constructs containing the rous sarcoma virus (rsv) src gene along with rsv enhancer stimulated expression but completely abolished sv40 dna replication. constructs, in which the heterologous enhancer sequences were omitted, did replicate normally in african green monkey kidney cells and, in the presence of helper virus, gave rise to infectious progeny. inhibition of sv40 dna replication follows a cis-acting mechanism and is most likely due to a conf ...	1989	2554858
clustering of discrete cell properties essential for tumorigenicity and metastasis. ii. studies of syrian hamster embryo fibroblasts transformed by rous sarcoma virus.	tumorigenic and metastasizing activities (tga; ma) and susceptibility, or resistance to h2o2 and pge-releasing activity (h2o2r + pges+ phenotype) have been examined in 6 syrian hamster embryo cell strains transformed in vitro with rous sarcoma viruses (schmidt-ruppin and prague strains). early observations of extremely high level of tga and even ma of rsv-sr-transformants never selected in vivo have been confirmed. the correspondence of these properties with a high level of expression of h2o2r + ...	1989	2555309
lipid characteristics of rsv-transformed balb/c 3t3 cell lines with different spontaneous metastatic potentials.	to determine whether a metastatic phenotype may be correlated with a characteristic lipid pattern, we compared the lipid composition of low metastasizing balb/c 3t3 cells transformed by the b77 strain of rous sarcoma virus (b77-3t3 cells) with that of a subclone isolated by growth in 0.6% agar, the b77-aa6 cells, which exhibit a high capacity for spontaneous metastasis. b77-3t3 cells revealed characteristics in their lipid composition common to other systems of transformed cells, i.e., an accumu ...	1989	2555644
cdna sequence of the long terminal repeat of a prb strain of the rous sarcoma virus.	the cdna library of the polya+ rna from prague b strain of rsv infected cells was constructed by the use of oligo(dt) primer and the reverse transcription method. the clones containing the ltr sequences were studied. the dna sequences of several clones were studied and compared with the cdna sequence of the long terminal repeat (ltr) region of a prb strain of rous sarcoma virus (rsv) which had previously been determined. by the analyses of several different cdna clones, mutations were detected i ...	1989	2556723
v-src induces clonal sarcomas and rapid metastasis following transduction with a replication-defective retrovirus.	v-src is an effective carcinogen when expressed from rous sarcoma virus (rsv) in vivo. whereas rsv tumors require sustained oncogene expression, their growth is largely a balance between viral recruitment of tissues and host immune destruction of infected cells. we have therefore examined the tumorigenic potential of v-src in the absence of viral recruitment and viral antigen expression. v-src was introduced with high efficiency into chicken wing web tissues using replication-defective (rd) retr ...	1989	2557619
[the family of env genes of avian retroviruses: molecular analysis of rous sarcoma virus adapted to duck cells].	for the elucidation of the molecular basis of rsv adaptation to conditionally permissive host from the genome library of duck embryo fibroblasts, transformed by rous sarcoma virus in 30 passages on these cells, recombinant bacteriophages that include provirus sequences, were obtained. complete and transformation-defective proviruses were characterized, nucleotide sequences of their env-genes were compared with their counterparts the original rsv (pr-rsv-c) and with viruses of other subgroups (a, ...	1989	2558292