Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| identification of the 5' end of rous sarcoma virus rna. | the 5'-terminal triphosphate of the 35s rna isolated from rous sarcoma virus is blocked by 7-methylguanosine in 5' linkage with the penultimate nucleoside which is methylated in the 2'-o-ribose position, a type of endgroup found in all animal mrnas investigated during the past year. the specific nuclease-resistant terminal fragment of rsv rna has the structure 7mg5'ppp5'gmpcp-. this finding supports the belief that rna of rous sarcoma virus represents a (+) strand messenger which may be directly ... | 1975 | 171660 |
| the expression of avian gs antigen in mammalian rous sarcoma virus-transformed cells after treatment with 5-iododeoxyuridine and dexamethasone. | the content of avian gs antigen in rsv-transformed rat cells lw13-rsk1 and lw13-rsk4 showed a transient increase after treatment with 5-iododeoxyuridine. higher levels of gs antigen were found when treated cells were cultivated in the presence of dexamethasone. in no case was the production of rsv found in treated rsv-transformed rat cell lines when, in addition, xc cells were tested. | 1975 | 172376 |
| characteristics of infection by rsv. iii. duration of the latent period in unsynchronized chick embryo fibroblasts. | the duration of the latent period of rsv was studied in unsynchronized chicken cells using two methods. first, rav1-producing cells were infected with schmidt-ruppin strain of rous sarcoma virus (sr-rsv;subgroup d), and new virions of sr-rsv (subgroup a) produced after phenotypic mixing with rav1 were neutralized with an antiserum to rav1. secondly, uninfected chicken cells were infected with sr-rsv (d) in the presence of either arabionsylcytosine, actinomycin d or cycloheximide, to inhibit the ... | 1975 | 172471 |
| mapping of biological functions on rna of avian tumor viruses: location of regions required for transformation and determination of host range. | a map of the large t1 oligonucleotides of the rna of prague rous sarcoma virus, strain b (pr rsvb) has recently been established (coffin and billeter, submitted for publication). since the rna of rous associated virus, type 1 (rav-1) lacks many of the large 1 oligonucleotides of pr rsv-b and contains others not present in the latter, the rna of recombinants between rav-1 and pr rsv-b could be analyzed with regard to the origin of its sequences. recombinants were selected for transforming capacit ... | 1975 | 174075 |
| properties and kinetics of development of rous sarcoma virus-infected cells evidenced by methylene blue staining. | three different kinds of areas of infected cells corresponding to different focus formation stages can be evidenced by methylene blue (mb) staining in cultures of chick embryo (ce) fibroblasts infected at low multiplicity with the temperature-sensitive (ts) mutant of rous sarcoma virus (rsv), fu19, which transforms these fibroblasts at 37 degrees but not at 41 degrees. these are: (a) areas of mb-stainable cells with transformed phenotype (stp areas=foci); (b) areas of mb-stainable cells with nor ... | 1975 | 57944 |
| detection and characterization of rna tumor virus-specific dna in cells. | rna tumor virus-specific dna in cells can be detected by its capacity to 1) alter the reassociation kinetics of labeled double-stranded product of viral rna-directed dna polymerase; 2) anneal single-stranded dna (cdna) synthesized by viral polymerase; or 3) hybridize labeled viral 70s (genomic) rna. duplexes formed with these procedures can be analyzed for fidelity of base pairing, and the integration of viral dna into the host genome can be established with a simple but stringent technique. we ... | 1975 | 51630 |
| transcription of the rous sarcoma virus genome in vitro and in vivo. | rna-directed dna synthesis by detergent-disrupted virions of rous sarcoma virus (rsv) initiates by the covalent attachment of pda to the 3'-terminal ra of a 4s rna hydrogen-bonded to the 70s rna template. this 4s "primer" has structural features of trna and can be aminoacylated with methionine. synthesis and integration of provirus dna can be monitored in both permissive (duck) and nonpermissive (mouse) cells acutely infected with rsv. the results of these studies, as well as data obtained with ... | 1975 | 51635 |
| rna-directed dna polymerase activity of reticuloendotheliosis virus: characterization of the endogenous and exogenous reactions. | reticuloendotheliosis virus (rev) contains an endogenously instructed, rna-directed dna polymerase activity. both the endogenous and exogenous dna polymerase activities exhibited up to 10-fold greater activity at the optimum concentration of manganous ion (0.025 mm for exogenous; 0.25 mm for endogenous) than at any concentration of magnesium ion. antiserum to the dna polymerase of an rev group virus (spleen necrosis virus) inhibited both endogenous and exogenous dna polymerase activity of rev, w ... | 1975 | 51935 |
| in vitro transcription of 70s rna by the rna-directed dna polymerase of rouse sarcoma virus: lack of influence of rnase h. | the influence of rous sarcoma virus (rsv)-associated rnase h on the in vitro synthesis of dna by the rsv rna-directed dna polymerase was determined under conditions whereby rnase h activity was selectively inhibited with naf. not only were we unable to detect any effect on the size, structure, or genetic complixity of the dna product synthesized in the absence of rnase h activity, but the displacement of dna from the 70s rna:dna hybrid structures was also unaffected. the suitability of 70s rna:d ... | 1975 | 54443 |
| [study of the population composition of the rous sarcoma virus carr-zilber strain]. | the population composition of the carr-zilber high titer (ht) strain of rous sarcoma virus (c-z-rsv) was analysed with regard to 2 features: the capacity to impart oncogenicity for syngeneic recipients to infected but untransformed cultures of mouse embryo tissue (met), and oncogenicity for mice. with regard to these features the c-z-rsv (ht) strain was found to be heterogenic and to consist of particles of at least two types: non-oncogenic for mice and incapable of causing early malignization o ... | 1975 | 176824 |
| infectivity of rous sarcoma cell dna: comparison of two techniques of transfection assay. | a dna extracted from a clone of chicken cells transformed by the schmidt-ruppin strain of rous sarcoma virus, subgroup d(sr-rsv-d), was assayed for infectivity by means of deae-dextran and calcium techniques. the calcium technique like the previously described deae-dextran procedure gave rise to viruses in transfection assays with both native and denatured (s1 nuclease susceptible) dnas. the efficiency of these transfection techniques with native dna was compared and found to be about the same p ... | 1975 | 181347 |
| effects of growth conditions on cyclic nucleotide phosphodiesterases of cultured fibroblasts. | cyclic nucleotide phosphodiesterase activities of baby hamster kidney cells (bhk) grown in surface cultures were altered by modifying growth conditions. the untransformed bhk cells grown in medium containing 10% fetal calf serum showed non-linear lineweaverburk plots for cyclic amp phosphodiesterase activity with apparent michaelis constants for cyclic amp of approximately 5 and 30 mum. when these cells were placed in medium containing 1% fetal calf serum, linear kinetic plots for cyclic amp pho ... | 1975 | 178699 |
| electron microscopy of rous sarcoma virus genome rna and its heat-dissociated subunits. | native and heat-treated rnas from the purified schmidt-ruppin strain of rous sarcoma virus (rsv) were fractionated by sucrose density gradients in the presence of ribonuclease inhibitor diethyl-pyrocarbonate and observed by electron microscopy. the structure of native 60-70s rna was classified into two forms: tanglefolded type and linear type. in the tangle-folded type double stranded portions were observed in several sites. a high frequency of 60-70s rna were 1.0 mum and 3-3.5 mum in length. mo ... | 1975 | 179284 |
| contamination of some avian species with viruses of the leukosis-sarcoma complex. | contamination of 8 avian species with leukosis viruses was studied. an insignificant portion of sera from 4 and 24 months old chickens contained neutralizing antibody to 3 sero-types (a, b and d) of rous sarcoma virus (rsv). sera from guinea-fowl reacted positively in the neutralization test only with the rsv-rav-1 strain. none of the peking duck and semi-domestic maran fowl sera was found to contain antibody to rsv strains. twenty-five and 6.6% of embryos derived from 7-8 and 24 to 30 months ol ... | 1975 | 235202 |
| cell surface changes accompanying viral transformation: n-acetylneuraminic acid ectotransferase system activity. | the activity of the sialyl ectotransferase system of normal chick embryo fibroblasts (cef) and chick embryo fibroblasts transformed with the schmidt-ruppin strain of rous sarcoma virus (sr-rsv) have been compared. neuraminidase treatment of the intact cells increased the sialyl ectotransferase system activity of control and transformed cells two to three times. the ectotransferase system activity increased as the ph was decreased from 7.8 to 6.0. the temperature optimum for both systems was 40 d ... | 1975 | 239405 |
| [investigations into the relationship of cell susceptibility and antibody formation and its importance in the pathogenesis of avian leukosis]. | crossbred progeny from matings of leghorn males (lines m and g), predominantly susceptible to leukosis infection, and females from a predominantly leukosis-resistant line (line r) showed a high incidence of mortality from spontaneous leukosis. immunological tests revealed that this field infection was caused by a subgroup a leukosis virus. tests for susceptibility to infection and presence of rsv antibodies in embryos and pullets respectively of lines r, g and m yielded the following results: li ... | 1975 | 18777299 |
| an antigen in normal avian cells which confuses virological and serological tests. | a cytoplasmic antigen was detected by fluorescent antibody tests in normal lymphoid and fibroblastic cells from chickens and other avian species when explanted and grown in culture. cells of the bursa of fabricius were consistently positive but cells of a proportion of thymus, spleen, bone marrow, buffy coat and embryo fibroblast cultures also were positive. eight of 19 fluorescein-conjugated chicken sera prepared for other studies on a variety of avian pathogens had antibody against the antigen ... | 1975 | 18777316 |
| respiratory syncytial virus and influenza. practical community surveillance. | concurrent and sequential outbreaks of infection with respiratory syncytial virus (rsv) and influenza a virus were studied, utilizing a local surveillance system for infectious diseases that involved weekly reports from primary care physicians. the patterns of illness in the community and in hospital admissions were relatively specific for these two viruses, and differed according to whether rsv and influenza a virus occurred together or separately. this surveillance system appeared to be a prac ... | 1976 | 937281 |
| role of maternal antibody in pneumonia and bronchiolitis due to respiratory syncytial virus. | fifteen infants with pneumonia caused by respiratory syncytial virus (rsv) and 19 infants with bronchiolitis caused by rsv were studied for the influence of homologous, circulating neutralizing antibody on the severity of their illness. all infants were under nine months of age. although maternal neutralizing antibody did not prevent infection with rsv and illness, the severity of pneumonia caused by rsv was inversely related to the level of neutralizing antibody. the severity of bronchiolitis c ... | 1976 | 977992 |
| association of a protease (plasminogen activator) with a specific membrane fraction isolated from transformed cells. | the intracellular distribution of specific protease, plasminogen activator (pa), has been examined in rous sarcoma virus-transformed chick embryo fibroblasts (rsv-cef). cellular homogenates were fractionated by differential centrifugation followed by sucrose gradient centrifugation. the activities and the percent distribution of a series of marker enzymes, specific for different subcellular organelles, were compared to those of pa. normal cef have been similarly fractionated and the relatively l ... | 1976 | 993259 |
| a comparison of influenza and respiratory syncytial virus infections among infants admitted to hospital with acute respiratory infections. | among 741 children under 5 years admitted to hospital with respiratory infections during two winters, infection with influenza a virus was diagnosed in 70 (9%), with influenza b virus in 8 (1%), and with respiratory syncytial virus (rsv) in 259 (35%). both influenza virus and rsv infections were diagnosed most frequently in children under the age of one year, and diagnosed more frequently in males than females. influenza illnesses were more severe in boys than girls. both infections occurred mor ... | 1976 | 1069818 |
| cell-mediated immunity to respiratory syncytial virus induced by inactivated vaccine or by infection. | transformation and increased mitotic activity in donor lymphocytes exposed to specific antigens is considered by many to be a manifestation of cell-mediated immunity. in attempts to understand the apparent "sensitization" of individuals to respiratory syncytial virus (rsv) as a result of receiving inactivated rsv vaccine, in vitro lymphocyte transformation studies were carried out on infants who had received inactivated rsv vaccine and on infants who had received a similarly prepared inactivated ... | 1976 | 1246465 |
| characterization of an early cytotoxicity-inducing factor in sera of japanese quails after inoculation with rous sarcoma virus. | by pre-treatment with serum of normal spleen cells used in the microcytotoxicity assay, a humoral factor which induces cytotoxic activity in normal spleen cells was demonstrated in about 40% of sera of japanese quails as early as 3 days after inoculation with rous sarcoma virus (rsv). this cytotoxicity-inducing activity was not present either in the igm or the igg fraction obtained by sephadex gel filtration. in sera of quails with experimentally induced agammaglobulinemia, the cytotoxicity-indu ... | 1976 | 179959 |
| respiratory syncytial virus infections in infants: quantitation and duration of shedding. | infants hospitalized with respiratory syncytial virus infection were studied to delineate the quantitative shedding patterns and duration of shedding of rsv. nasal wash specimens collected daily from 19 infants contained a mean maximal titer of 4.34 log10 50% tissue culture infective doses per milliliter. on admission, the mean titer was 4.14 log10 tcid50, with no consistent decline until after day 6. the mean duration of shedding for 23 patients until they were virus negative was 6.7 days with ... | 1976 | 180274 |
| temperature-sensitive changes in surface modulating assemblies of fibroblasts transformed by mutants of rous sarcoma virus. | the hypothesis that surface modulating assemblies containing microfilaments and microtubules and altered after cellular transformation was tested on cells infected with temperature-sensitive mutants of avian sarcoma virus. untransformed cells (mouse 3t3 and chick fibroblasts), cells transformed by simian virus 40 (sv 3t3), and chick fibroblasts infected with schmidt-ruppin strain of rous sarcoma virus (sr-rsv-a-infected cells) were first compared for differences in microfilament and microtubule ... | 1976 | 180536 |
| respiratory syncytial virus and heart disease. a report of two cases. | two patients had cardiac disease and serological evidence for respiratory syncytial virus (rsv) infection. the first patient had myocarditis and complete atrioventricular heart block with repeated syncopal episodes two weeks following infection. the second patient had alcoholic cardiomyopathy and worsening congestive heart failure associated with rsv infection. the significance of rsv infection in these two patients may bear a significant relationship to sudden infant death syndrome, chronic car ... | 1976 | 181602 |
| independent regulation of endogenous and exogenous avian rna tumor virus genes. | 3h-labeled complementary dna specific for the envelope glycoprotein (env) gene of avian leukosis-sarcoma viruses was isolated by selective nucleic acid hybridization techniques, and used to analyze the expression of the endogenous provirus. the endogenous provirus in certain cell types termed chicken helper factor positive (chf+) can synthesize the envelope glycoprotein. env dna sequences were present in both chf+ and chf- cells, but env rna was detectable only in positive cell types. when these ... | 1976 | 181750 |
| chicken egg yolk enhances focus formation by subgroup b, c and d rous sarcoma viruses. | focus formation by rous sarcoma virus (rsv) was significantly enhanced when virus was incubated with the saline fraction of chloroform extracted chicken egg yolk, prior to infecting chicken embryo cells. the enhancement was restricted to members of rsv subgroups b, c and d and was proportional to yolk dilution. subgroup a virus was never affected. in all, 108 yolk samples from specific pathogen free chickens were investigated. of these 78 to 97% stimulated focus formation. rsv(rav-50) of subgrou ... | 1976 | 182909 |
| 2-deoxy-d-glucose uptake by chick embryo cells: a biochemical indicator of genetic susceptibility to rna tumour viruses. | the enhanced glucose uptake by chick embryo cells as early as 72 h after infection with rous sarcoma virus (rsv) was confirmed in this study to be an early indicator of cellular transformation. the glucose uptake of c/e brl cells infected by various doses of bs-rsv of subgroup a showed that the relationship between the log-dose of virus and log-uptake was linear (slope, b1 = 1.30 +/- 0.14) when the ratio of the number of infectious virus particles to the number of cells in the culture was above ... | 1976 | 182917 |
| membrane lipid acyl group alterations in cells infected with a temperature-conditional mutant of rous sarcoma virus. | the increased percentage of oleic acid and decreased percentage of arachidonic acid which occurs in the lipids of chicken embryo fibroblasts transformed by rous sarcoma virus was shown to be transformation specific rather than a consequence of virus infection. cells infected with a temperature conditional mutant of rous sarcoma virus (rsv-t5) had a normal type fatty acid composition when held at the restrictive temperature of 41 degrees c, but had a transformed type fatty acid composition when h ... | 1976 | 183825 |
| neutral protease activity of rous sarcoma (rsv) transformed chick embryo fibroblasts. | the proteolytic activities of normal, schmidt-ruppin rous sarcoma virus (sr-rsv) transformed, and infected (rav) chick embryo fibroblasts (cef) have been measured by a highly sensitive technique using 3h-acetylated haemoglobin as a substrate. when all 3 types of cef cells were maintained in serumless media, no differences were detected in the amount of ph 3-4 protease activity released into the media over a 24-h period, and only negligible amounts of ph 7-6 proteolytic activity were found. when ... | 1976 | 184099 |
| further studies in genetic resistance of fowl to rsv(rav o): evidence for interaction between independently segregating tumour virus b and tumour virus e genes. | the segregation of resistant and susceptible phenotypes in response to infection by rsv(rav 2), rsv(rav 50) and rsv(rav 0), of avian rna tumour virus subgroups b, d and e, respectively, was analysed in several test-crosses using chickens from the rprl line 7-2, hprs-synthetic line e and the reaseheath line c. the results were fully consistent with out view reported previously that the genes at the tve and tvb loci segregate independently and recombine under the mendelian second law of independen ... | 1976 | 184240 |
| cell-free translation of virion rna from nondefective and transformation-defective rous sarcoma viruses. | nondefective and transformation-defective virion subunit rnas from two strains of rous sarcoma virus (rsv) were translated in cell-free systems derived from krebs iia ascites cells, wheat germ, and l-cells. in each case the predominant viral-specific product was a polypeptide of molecular weight 76,000 that is related to the internal viral group-specific antigens, as judged by immunoprecipitation with monospecific antisera and tryptic peptide fingerprinting. no difference could be detected betwe ... | 1976 | 184305 |
| characteristics of a human cell line successively transformed by rous sarcoma virus and simian virus 40. | human enbryo cells were successively transformed by the schmidt-ruppin strain of rous sarcoma virus (sr-rsv) and simian virus 40 (sv40) in vitro, and the double transformant hue 13 rs was established. from this cell line the two clonal cell lines rsa and rsb were isolated. in both, presence of sv40 t antigens was demonstrated by the fluorescent antibody technique, and the presence of rsv genomes was verified in one rsb clone by focus formation after fusion with chick embryo cells. growth of thes ... | 1976 | 186619 |
| rescue of rous sarcoma virus (rsv) from rsv-transformed human embryonic cells by cell fusion with chick embryo fibroblasts using lysolecithin. | heterokaryon formation and rous sarcoma virus (rsv)-induction were studied by fusion of rsv-transformed human embryonic cells with chick embryo fibroblasts in the presence of lysolecithin. heterokaryon formation was observed by autoradiography. rsv-induction was identified by focus formation, electron microscopy and density gradient centrifugation of 3h-uridine-labeled particles. the most effective concentration of lysolecithin for virus induction was 10 mug/10(6) cells/0.1 ml. efficiency of lys ... | 1976 | 187016 |
| interactions of concanavalin a with chick embryo fibroblasts transformed by rous sarcoma virus. study with an rsv mutant thermosensitive for transformation. | the interactions between concanavalin a and chick embryo fibroblasts, normal and infected with rous sarcoma virus (rsv-bh) or its thermosensitive mutant rsv-bh-ta, have been studied. normal chick embryo cells and rsv-bh transformed cells showed at 4 and 25 degrees c a similar number of concanavalin a receptors per cell. analysis of the binding data by the scatchard relation showed that apparent changes in binding as a function of temperature are due to the thermodynamic properties of the process ... | 1976 | 187246 |
| sodium: a regulator of glucose uptake in virus-transformed and nontransformed cells. | observations of cells transformed by the bryan strain of rous sarcoma virus (rsv-bh) suggested that the intracellular concentrations of sodium ion (na+) may play a critical role in cellular metabolism. in an attempt to manipulate intracellular na+, chick embryo cells were exposed to graded concentrations of na+ in the cellular growth medium, and the effects on capacity for glucose uptake was examined. after incubation for six hours, the incorporation rate of 2-deoxyglucose (used as a substitute ... | 1976 | 188836 |
| [transfer of the genetic information of oncornaviruses by means of tumor cell dna]. | the infection process was reproduced in the culture of chick embryonal cells by means of: a) dna isolated from chick rous sarcoma (carr-zilber strain); b) dna from blood cells of chicks with myeloblastosis (strain a); c) dna from rous virus malignified (prague strain) rat cells (xc). antigenic properties of the virus, transfected with dna from chick rous sarcoma, would differ from the original parental strain (carr-zilber rsv), that evidences the possibility of a partial transfer of genetic info ... | 1976 | 178103 |
| in vivo host immune to a tumor-specific transplantation antigen induced by rous sarcoma virus. | we examined the host immune response to a tumor-specific transplantation antigen (tsta) induced by rous sarcoma virus (rsv) in vivo. in contrast to previous in vitro studies, the present investigation demonstrated in vivo host immunity of the tsta 10-55 days after tumor inoculation. immunity to the tsta appeared specific, since the homologous rsv tumor was rejected. whereas the heterologous tumor grew progressively. no generalized suppression of cell-mediated or hymoral immunity was shown, becau ... | 1976 | 56445 |
| formation of an infectious virus-antibody complex with rous sarcoma virus and antibodies directed against the major virus glycoprotein. | preparations of rous sarcoma virus (rsv) can form an infectious viral-antibody complex with antibodies raised against the major glycoprotein, gp85, isolated from avian myeloblastosis virus and prague-rsv subgroup c. binding of anti-gp85 antibodies to rsv can be demonstrated by the inhibition of focus-forming activity after addition of goat anti-rabbit immunoglobulin and by a shift in density of virions treated with anti-gp85 serum. group- rather than subgroup- specific regions of viral gp85 appe ... | 1976 | 56458 |
| transformation of cells by rous sarcoma virus: cytoplasmic vacuolization. | chick embryo cells transformed by the bryan "high titer" strain of rous sarcoma virus (rsv-bh) are heavily vacuolated. a variety of microscopic techniques have been used demonstrating that the vacuoles are cytoplasmic, bounded by membrane, and are composed largely of water. proteins, lipids, glycoproteins, glycolipids, glycosaminoglycans, glycogen, and nucleic acids were undetectable in the vacuoles. physiological requirements for development of the vacuoles, and reversal of vacuolization, were ... | 1976 | 54359 |
| recombination between a temperature-sensitive mutant and a deletion mutant of rous sarcoma virus. | cells doubly infected with two mutants of the schmidt-ruppin strain of rous sarcoma virus (rsv), ts68, which is temperature sensitive for cell transformation (srcts), and a deletion mutant, n8, which is deficient in the envelope glycoprotein (env-), produced a recombinant which carried the defects of both parents. the frequency of formation of such a recombinant was exceptionally high and made up 45 to 55% of the progeny carrying the srcts marker. by contrast, the reciprocal recombinant, which i ... | 1976 | 60496 |
| comparison of dna in the core component from schmidt-ruppin rsv transforming virus and non-transforming virus. | 1976 | 61031 | |
| endogenous dna polymerase of a transformation-defective rous sarcoma virus: characterization and comparison with the enzyme of the non-defective parent. | an rna-directed dna polymerase associated with transformation-defective (td) segregant of rous sarcoma virus (rsv) has been characterized. the enzyme required both a monovalent and a divalent cation, a sulfhydryl reducing agent, and all four deoxyribonucleoside triphosphates for the expression of maximal activity. sensitivity of the endogenous rna-directed dna polymerase activity to a low concentration of pancreatic rnase indicated that the enzyme utilized the td virus endogenous rna as template ... | 1976 | 62591 |
| a comparison of four methods used to concentrate rous sarcoma virus from tissue culture fluids. | three methods of pelleting, pelleting followed by pronase treatment, polyethylene glycol (peg)-pronase, and diaflo ultrafiltration (diafiltration) were used to concentrate rsv(rav-1) from tissue culture fluids. sucrose-gradient fractions containing virus preparations which had been concentrated by diafiltration or pelleting were heavily contaminated with amorphous debris. this debris was not present in similar, gradient-purified preparations that had been concentrated by the peg-pronase or pelle ... | 1976 | 63539 |
| fibroblast surface antigen (sf): the external glycoprotein lost in proteolytic stimulation and maligant transfromation. | it was previously shown that the fibroblast surface antigen (sf antigen, sfa) is composed of polypeptides of high molecular weight 210,000 (sf210) and 145,000 (sf145) and that both of these decrease in quantity after transformation of the fibroblasts by rous sarcoma virus (rsv). the present experiments show that sf210 is a glycoprotein. it is accessible to surface labelling by lactoperoxidase catalyzed iodination. the sf210 molecule is highly susceptible to trypsin on cell surface. anti-sfa anti ... | 1976 | 175031 |
| induction of syncytia by the bovine c-type leukemia virus. | bovine buffy coat cells infected with the bovine leukemia virus (blv) induce syncytia formation in human diploid embryonic lung cells as well as in monolayer cell cultures of bovine, simian, ovine, bat, and caprine origin, but not in mouse fibroblast cells, normall rat kidney cells, or rsv-transformed rat cells. syncytia were not observed in diploid embryonic lung cells inoculated with bovine buffy coat cells free of blv. the syncytia-induction effect is associated with the synthesis of complete ... | 1976 | 175949 |
| transformation-enhancing factor(s) produced by virus-transformed and established cells. | chick embryo fibroblasts (cef) and hamster bhk21 cells transformed by the schmidt-ruppin strain of rous sarcoma virus (sr-rsv) release into the culture medium a factor or factors which enhance 2- to 7-fold the formation of transformed foci by chich embryo fibroblasts infected with the bryan strain of rsv (b-rsv). the factor(s) also increase the number of foci failing to revert to normal phenotype at restrictive temperature (41 degrees c) in cultures infected with a temperature-sensitive mutant ( ... | 1976 | 176116 |
| hydrodynamic diameters of murine mammary, rous sarcoma, and feline leukemia rna tumor viruses: studies by laser beat frequency light-scattering spectroscopy and electron microscopy. | we have studied purified preparations of murine mammary tumor virus (mumtv), rous sarcoma virus (rsv; prague strain), and feline leukemia virus (felv) by laser beat frequency light-scattering spectroscopy, ultra-centrifugation, and electron microscopy. the laser beat frequency light-scattering spectroscopy measurements yield the light-scattering intensity, weighted diffusion coefficients. the corresponding average hydrodynamic diameters, as calculated from the diffusion coefficients by the stoke ... | 1976 | 176431 |
| [differential expression of relevant rous sarcoma tumor antigens in cultured cells]. | chickens bearing tumours induced by rous sarcoma virus (rsv) are able to mount a cellular immune response against antigens associated with these neoplasms. cultured rous sarcoma (rs) cells, derived from the wings of chickens bearing tumors induced by rsv, were consistently more susceptible in cytotoxicity assays to killing by the splenic lymphocytes of rs-bearing chickens than were chicken embryo fibroblast (cef) cells which had been transformed in vitro by rsv. in contrast, extracts (3m kci-der ... | 1977 | 66892 |
| tumor growth and antibodies after rsv-challenge in normal chickens and in chickens congenitally infected with avian leukosis virus. | normal chickens and chickens congenitally infected with an avian leukosis virus (alv) of antigenic subgroup a were challenged with strains of rous sarcoma virus (rsv) of two different antigenic subgroups (b and c) and tumor induction and growth as well as humoral antibody to viral envelope antigen (vea) and tumor-specific surface antigen (tssa) were measured. there was no effect of congenital alv infection on rsv tumor incidence or latent period but the growth rate and size of the tumors were mu ... | 1977 | 67140 |
| new procedure for the direct analysis of in vitro reverse transcription of rous sarcoma virus rna. | based on the observation that in vitro transcription of rous sarcoma virus (rsv) rna by avian myeloblastosis virus dna polymerase renders the rna progressively more sensitive to escherichia coli rnase h digestion, a new procedure for the in situ analysis of this process has been developed. in vitro transcription products of 32p-labeled rsv rna are first treated with rnase h, the resistant fraction is then digested to completion with rnase t1, and the oligonucleotides are analyzed by a fingerprin ... | 1977 | 67218 |
| cellular and humoral anti-tumor immune responsiveness in chickens bearing tumors induced by avian sarcoma virus. | a systematic comparison was undertaken of the respective abilities of normal chicken embryo fibroblast (cef) cells, rous sarcoma virus (rsv)- transformed cef cells, avian rous sarcoma (rs) tumor cells and murine rs cells to serve as targets and antigen donors in various assays for the detection of cellular and humoral anti-tumor immunity in chickens bearing tumors induced by rous sarcoma virus. as measured by a cytotoxicity procedure, avian and murine rs cells were more susceptible to the killin ... | 1977 | 68016 |
| extensive in vitro transcription of rous sarcoma virus rna by avian myeloblastosis virus dna polymerase and concurrent activation of the associated rnase h. | conditions are described that promote the efficient reverse transcription of most of rous sarcoma virus (rsv) rna sequences by avian myeloblastosis virus dna polymerase in vitro. a detailed analysis of the reverse transcription reaction was carried out using two procedures: in situ analysis of the rna sequences transcribed and dna-rna annealing studies. under optimal conditions, after 1 h of reaction, practically all rsv rna sequences were transcribed with a frequency varying from 30 to 90%. the ... | 1977 | 70539 |
| virological and immunological characteristics of tumors induced in adult rats by rous sarcoma. | forty primary tumors of wistar rats and first seven passages of tumors of august rats were investigated by different virological and immunological methods. the tumors were induced in adult rats by schmidt--ruppin strain of rous sarcoma. based on the virus-cell interaction, the tumors were divided into four groups. the first group of tumors of wistar rats (2 out of 40) contained mature rsv and viral antigens could be detected by means of the fa test, while the rats had virus neutralizing antibodi ... | 1977 | 73143 |
| anti-tumor virus activity of copper-binding drugs. | several, structurally different, copper-binding ligands can inhibit the rna-dependent dna polymerase of rous sarcoma virus (rsv) and can inactivate the ability of the virus to malignantly transform chick embryo cells. these ligands include the anti-microbial agents, thiosemicarbazones, 8-hydroxyquinolines, isonicotinic acid hydrazide, and others. many of these compounds bind to dna and rna in the presence of copper, which may play a role in their anti-viral activity. however, not all agents acti ... | 1977 | 75679 |
| coordinate control of collagen synthesis and cell growth in chick embryo fibroblasts and the effect of viral transformation on collagen synthesis. | using collagenase digestion as an assay for collagen in partially synchronized secondary cultures of chick embryo fibroblasts, we find that the rate of collagen synthesis remains at a constant fraction of overall protein synthesis (5%) regardless of the growth rate of the cells even when the rate of protein synthesis is accelerated 5-fold by adding serum and altering the ph of the culture medium. however, in cells oncogenically transformed by rous sarcoma virus, the relative rate of collagen syn ... | 1977 | 19483 |
| inactivation and inhibition of rous sarcoma virus by copper-binding ligands: thiosemicarbazones, 8-hydroxyquinolines, and isonicotinic acid hydrazide. | we have shown that three types of copper-binding ligands, thiosemicarbazones, 8-hydroxyquinolines, and isonicotinic acid hydrazide and their copper complexes, inactivate the transforming ability of rsv and inhibit its rna-dependent dna polymerases. three other compounds, 2-pyridine thiosemicarbazone, 1-formyl isoquinoline thiosemicarbazone, and diphenyl thiocarbazone inhibit transformation by rsv intracellularly. most but not all of these compounds bind to nucleic acids in the presence of copper ... | 1977 | 81642 |
| a continuous line of rous sarcoma virus-transformed chick embryo cells. | a continuous line of rous sarcoma virus (rsv)-transformed chick embryo cells was established. the cells, designated rtaz-1, which constitute the only known line of continuously growing rsv-transformed cells of chick embryo origin, grow rapidly, display uniform morphology, and perpetually release large amounts of rsv (rous-associated virus, type 1). rtaz-1 cells display a heteroploid chromosome complement with 92-94 chromosomes characteristic of chicken cells. molecular hybridization studies demo ... | 1977 | 189048 |
| the genome-associated, specific rna binding proteins of avian and mammalian type c viruses. | a structural protein purified from the rous sarcoma virus (rsv) can specificially bind in vitro to purified avian, but not mammalian, type c viral rna. following ultraviolet irradiation of viral particles under conditions which stabilize the polyploid 70s viral rna, the same polypeptide can be directly purified from the rsv genome. based on its electrophoretic mobility in polyacrylamide gels containing sodium dodecylsulfate, the rna binding protein has been identified as the major phosphoprotein ... | 1977 | 189935 |
| body temperature and tumor virus infection. i. tumorogenicity of rous sarcoma virus for reptiles. | rous sarcoma virus (rsv) was oncogenic for the following nine species of reptiles representing 6 families from chelonia and squamata orders: family of testudinidae: 1. testudo horsfieldi, family agamidae: 2. agama sanguinolenta; 3. agama erythrogastra, family lacertidae: 4. eremias persica; 5. eremias velox; 6. eremias grammica, family scincidae: 7. eumeces taeniolatus, family boidea: 8. erix tataricus, 9. ancistrodom blomhoffi. rsv did not induce tumors in 13 studied species of reptiles. histol ... | 1977 | 190549 |
| characterization of tumour virus proteins. i. radioimmunoassay of the p27 protein of avian viruses. | the major structural protein of avian oncornaviruses, a core component of about 27000 daltons, has been measured by radioimmunoassay. the purified protein was labelled with 125iodine by chloramine-t method. the immune serum titer was defined as the highest serum dilution able to precipitate 50% of the labelled antigen present in the system. standard competition curve was constructed in order to determine the equivalents of protein, in a system with limiting antibody concentration. in the experim ... | 1977 | 190652 |
| altered sensitivity of rous sarcoma virus transformed cells to inhibition of rna synthesis by alpha-amanitin. | chick embryo cells transformed by rous sarcoma virus (rsv) continue to synthesize 40--50 percent of control amounts of rna following 12--24 hour exposure to 2 microng/ml of the toxin whereas normal chick embryo cells similarly treated synthesize less than 5 percent of control amounts of rna. analysis of cells treated with alpha-amanitin, or the resistant forms i and iii polymerase, do not increase in infected cells over the levels found in uninfected control cells during the first 24 hours follo ... | 1977 | 192178 |
| studies on the synthesis and structure of mitochondrial dna in cells infected by rous sarcoma viruses and on the occurrence of intramitochondrial virus-like particles in certain rsv-induced tumor cells. | 1. the synthesis of mitochondrial dna in cef in vivo at 3,4 and 6 days after infection with rsv (schmidt-ruppin, subgroup a) was progressively stimulated 2 to 4-fold as compared with that in uninfected cef cells grown in parallel. 2. the stimulation of mtdna synthesis in vivo upon transformation was found to be temperature dependent when the thermosensitive mutant of rsv, t5, was used to infect the cells. 3. in contrast to mtdna synthesis, nuclear dna synthesis did not differ in transformed and ... | 1977 | 192995 |
| microinjection analysis of envelope-glycoprotein messenger activities of avian leukosis viral rnas. | virion rna from the avian leukosis virus rous-associated virus 2 (rav-2) and poly(a)-containing rnas from rav-2-infected chick embryo fibroblasts were microinjected into fibroblasts transformed by the bryan high-titer strain of rous sarcoma virus (rsv), which is deficient in viral envelope glycoprotein. production of infectious rsv following these injections depended upon the viral envelope-messenger activity of the injected rna. this system constituted a sensitive and rigorous assay system for ... | 1977 | 193109 |
| presence of ribonucleotide sequences complementary to rous sarcoma virus (rsv) rna in chicken cells infected with rsv. | rna--rna molecular hybridization between [125i] rna from rous sarcoma virus virions and rnas isolated from various subcellular fractions, i.e. nuclei, mitochondria, free and membrane-bound polyribosomes, from tumors induced by rsv in chickens resulted in the formation of rnaase-resistant hybrids only with the rna of mitochondria and membrane-bound polysomes. the origin of complementary regions in the rnas from these organelles is discussed. | 1977 | 193629 |
| changes in synthesis of dna-binding proteins during the onset of transformation in nrk cells transformed by a temperature-sensitive mutant of rous sarcoma virus. | synthesis of cytoplasmic dna-binding proteins was investigated after a shift from the nonpermissive to the permissive temperature in nrk cells transformed by a temperature-sensitive mutant of rous sarcoma virus [ts339(rsv)]. cells were labeled for several generations in [3h]leucine and were pulse-labeled with [35s]methionine for 1 h at the nonpermissive temperature (39 degrees c) and at the permissive temperature (33 degrees c, 5 h after shift from 39 degrees c). proteins binding to sequential c ... | 1977 | 194062 |
| incomplete viral genome in a non-virogenic mouse tumour cell line (rvp3) transformed by prague strain of avian sarcoma virus. | two cell lines, rvp3 and rva4, derived originally from mouse tumors induced by the prague and schmidt-ruppin strain of rsv, respectively, were studied. tall attempts failed to induce infectious virus production in rvp3 cells by fusion with chicken fibroblasts even if the cells were infected with avian leukosis viruses. also, attempts to rescue the viral genome by transfection were unsuccessful. rvp3 cells harboured 31-45% of the viral genome sequences, as was shown by molecular hybridization, an ... | 1977 | 194849 |
| formation of reticuloendotheliosis virus pseudotypes of rous sarcoma virus. | superinfection of chicken embryo fibroblasts transformed by the defective bryan strain of rous sarcoma virus (bh-rsv) with two different reticuloendotheliosis viruses (revs), rev strain t (rev-t) or spleen necrosis virus (snv), resulted in the production of infectious sarcoma virus pseudotypes. these pseudotypes were neutralized by antiserum prepared against snv and were unable to infect chicken cells preinfected with either rev-t or snv. these results suggest that defective bh-rsv is able to us ... | 1977 | 195082 |
| transformation of chicken embryo retinal melanoblasts by a temperature-sensitive mutant of rous sarcoma virus. | retinal melanoblasts were transformed by a temperature-sensitive mutant of rous sarcoma virus (ts-rsv). at the permissive temperature for transformation, the cells cease melanin synthesis, degrade their melanosomes and release much of their accumulated melanin into the medium. at the nonpermissive temperature, the cells assume an epithelioid morphology, actively synthesize melanin and become difficult to distinguish from normal uninfected control cultures. both the transformed phenotype and the ... | 1977 | 196765 |
| virus-specific rna in selected cell lines derived from rsv-induced tumour. | the presence of virus-specific rna in mammalian tumour cell lines of rsv aetiology was studied using molecular hybridization between the pr-rsv 3h-dna probe synthetized by the endogenous rna-directed dna polymerase reaction and cellular rna. it was found that both virogenic xc cells harbouring the full pr-rsv genome and cryptovirogenic rvp3 cells harbouring an incomplete pr-rsv genome contain virus-specific rna. the degree of homology between such rna and pr-rsv 3h-dna probe reached 10--12% in x ... | 1977 | 198254 |
| in vitro translation yields a possible rous sarcoma virus src gene product. | in vitro translation of rous sarcoma virus (rsv) virion rna in the messenger-dependent reticulocyte lysate system yielded polypeptides that were not synthesized by translation of rna from a transformation-defective deletion mutant of rsv. these rsv-specific products migrated on sodium dodecyl sulfate/polyacrylamide gels as two doublets of approximately 25,000 and 17,000 daltons. synthesis of these proteins was not sensitive to inhibition by m7gtp; however, synthesis of the 76,000-dalton precurso ... | 1977 | 198780 |
| [cellular contaminants and structural proteins of rous sarcoma virus (rsv), studied by polyacrylamide gel electrophoresis]. | the number of polypeptides in highly purified preparations of rsv, of two different subgroups, produced in culture, has been compared to the polypeptides present in the supernatant of uninfected cultures and processed in identical manner. the analysis of page-sds shows that from 13 to 18 polypeptides present in viral preparations may be cellular contaminants. fewer contaminating polypeptides are found in the myeloblastosis virus purified from plasma of chicken. | 1977 | 199367 |
| nucleotide sequences derived from pheasant dna in the genome of recombinant avian leukosis viruses with subgroup f specificity. | recombination between viral and cellular genes can give rise to new strains of retroviruses. for example, rous-associated virus 61 (rav-61) is a recombinant between the bryan high-titer strain of rous sarcoma virus (rsv) and normal pheasant dna. nucleic acid hybridization techniques were used to study the genome of rav-61 and another rav with subgroup f specificity (rav-f) obtained by passage of rsv-rav-0 in cells from a ring-necked pheasant embryo. the nucleotide sequences acquired by these two ... | 1977 | 199737 |
| effect of tunicamyein on the morphogenesis of semliki forest virus and rous sarcoma virus. | semliki forst virus (sfv) infected chick embroyo cells (cec) incubated in the presence of tunicamyein, a drug which specifically inhibits glycosylation, were studied under the electron microscope. no extracellular virions were produced although intracellular viral nucleocapsids in paracrystalline form were detected. under these conditions the structures, referred to as type 1 and 2 cytopathic vacuoles (cpv-1 and cpv-2, respectively) as well as membraneous spherules at the plasma membrane could s ... | 1977 | 200200 |
| recovery of avian sarcoma virus from tumors induced by transformation-defective mutants. | transformation-defective (td) mutants of the schmidt-ruppin strain of rous sarcoma virus (rsv), which contains deletions in the gene responsible for transformation (src gene), are unable to transform chicken embryo fibroblasts in vitro. injection of some of these td mutants into newborn chickens resulted in the formation of sarcomas from which sarcoma virus was unfailingly recovered. the possibility that transforming rsv was present in the td virus preparations was excluded by further purificati ... | 1977 | 200700 |
| avian tumour virus interactions with chicken fibroblast membranes: partial characterization of initial attachment site activity. | exposure of chicken embryo fibroblasts (cef) to trypsin solubilizes cell surface components, including the initial attachment site for avian tumour viruses (atv). the soluble attachment site activity appears to interact directly with the atv in vitro thereby interfering with the binding of at least two atv subgroups to both intact cef and cef plasma membranes. a result of this interaction in vitro is reduced atv infectivity, demonstrated by reduced transforming capacity of rsv (rav-i). | 1977 | 200712 |
| cellular transformation and differentiation. effect of rous sarcoma virus transformation on sulfated proteoglycan synthesis by chicken chondrocytes. | incorporation of sulfate into sulfated proteoglycans by isolated chicken chondrocytes was inhibited up to 74% by transformation with the rous sarcoma virus, and a similar inhibitory effect was observed on acetate incorporation into chondroitin sulfate. slower sedimenting sulfated proteoglycans appear after the viral transformation. the ratio of chondroitin 4-sulfate to chondroitin 6-sulfate in these slower sedimenting sulfated proteoglycans was different from that of normal chondrocytes, but the ... | 1977 | 200905 |
| increased growth of rous sarcomas in chickens pretreated with formalinized syngeneic tumor cells. | the effect of inoculating formalinized syngeneic or allogeneic rous sarcoma cells on the growth of rous sarcoma virus (rsv)-induced tumors in two related inbred strains of chickens was studied. chickens from both strains that received three weakly inoculations of syngeneic tumor cells had a significant increase in tumor growth and mortality after subsequent challenge with rsv. development of rsv-induced tumors in chickens pretreated with formalinized allogeneic tumor cells (i.e. incompatible for ... | 1977 | 201468 |
| [susceptibility to avian tumor viruses: determination of chick phenotypes]. | the genetic cellular susceptibility to avian sarcoma viruses (rsv) of subgroups a, b, c and e has been determined in one week old chicks. fibroblasts from pin feathers were grown in vitro and tested by focus formation after infection. this technique will allow, for the first time, the study of the influence of the host phenotypes (susceptibility or resistance to the different subgroups of rsv) upon the immune response to a given virus. | 1977 | 206373 |
| complement fixation and neutralization rs antibodies in maternal and neonatal sera. | rsv complement fixation antibodies were established in 200 paired maternal and cord blood sera. geometric mean titres in cord sera were significantly higher than in matermal sera. the differences did not depend on the virus strain used. half of the paired sera (taken at random) were also submitted to microneutralization tests. no differences were found between geometric mean titres in maternal and cord sera. | 1977 | 266541 |
| respiratory syncytial virus in early infancy. circulating antibody and the severity of infection. | forty-one children less than 6 months of age from whom respiratory syncytial virus (rsv) was isolated were divided into groups of varying severity of illness. no relationship was demonstrated between severity of illness and the complement fixation titer to rsv in cord sera, acute sera, or convalescent sera. an increase in igm level of greater or equal to 15 mg/100 ml in association with the rsv infection was seen more frequently in infants who had higher igm levels in their acute sera than in in ... | 1977 | 835529 |
| apnea associated with respiratory syncytial virus infection in young infants. | the hospital charts of 274 infants under 6 months of age with culture-proved respiratory syncytial virus infections were reviewed. fifty-six infants (20.4%) demonstrated apnea in association with rsv infection. predisposing factors significantly correlated with apnea included premature birth and young chronologic age at the time of virus infection. the clinical implications of this association are discussed. | 1977 | 839330 |
| role of cell-mediated immunity (cmi) in chickens inoculated with avian leukosis/sarcoma virus. | immunosuppression of chickens infected in ovo with avian leukosis virus (rav-1) by the injection of antilymphocyte serum (als) did not significantly (p > 0.05) alter the incidence or distribution of lesions in chickens between 3 and 6 months of age as compared to control groups. antilymphocyte serum treatment of rous sarcoma virus [rsv (rav-2)]-infected chickens significantly (p < 0.05) inhibited tumour regression and enhanced tumour metastasis. it was concluded that cell-mediated immunity was n ... | 1977 | 18770324 |
| virus-specific rna species present in the cytoplasm of rous sarcoma virus-infected chicken cells. | polyadenylated and nonpolyadenylated cytoplasmic rna from chicken cells infected with wild-type (wt) and transformation-defective (td) rous sarcoma virus (rsv) were fractionated on sucrose density gradients and hybridized with a [3h]cdna probe complementary to rsv-rna to determine the size distribution of virus-specific rna. two major species of poly (a) -containing viral rna sedimenting at 35 and 21 s were detected in wt and td virus-infected cells. both rna classes were released from polyribos ... | 1977 | 18625472 |
| the distribution of virus-specific rna in rous sarcoma virus-induced hamster tumor cells. | poly(a)-containing cytoplasmic rna and nuclear rna from rous sarcoma virus (rsv)-induced hamster tumor cells was fractionated on sucrose density gradients and hybridized with a [3h]cdna probe to determine the size distribution of virus-specific rna. one size class of viral rna sedimenting at 21 s was detected in cytoplasmic poly(a)-containing rna. nuclear rna contained three species of virus-specific rna sedimenting at 47, 35, and 21 s. sedimentation of nuclear rna under denaturing conditions di ... | 1977 | 18625473 |
| observations on outbreaks of respiratory disease in housed calves--(1) epidemiological, clinical and microbiological findings. | in 47 of 50 outbreaks of respiratory disease in indoor calves which had never been to grass there was clinical evidence of pneumonia in all animals examined. calf housing was in most cases considered unsatisfactory. virus activity was detected in 70 per cent of outbreaks investigated within a few days post onset of respiratory signs. parainfluenza (pi) 3 and respiratory syncitial virus (rsv) were the viruses most frequently involved. in the majority of outbreaks mycoplasma species and pasteurell ... | 1978 | 219582 |
| the immunologic response to infection with respiratory syncytial virus in infants. | fifty infants younger than six months, hospitalized for infection with respiratory syncytial virus (rsv), were studied by examination of serial samples of nasal secretion. secretory neutralizing activity was measured by plaque reduction and secretory antibody by indirect fluorescence using conjugated antiserum to human iga, igg, or igm. secretory neutralizing activity during infection rose or fell fourfold with approximately equal frequency (20% and 26%, respectively). in contrast, levels of iga ... | 1978 | 355574 |
| respiratory syncytial virus infection: admissions to hospital in industrial, urban, and rural areas. report to the medical research council subcommittee on respiratory syncytial virus vaccines. | a collaborative study of 10 centres during the winters of 1973-4 and 1974-5 showed that respiratory syncytial virus (rsv) was the major cause of admission to hospital for respiratory disease in children under 5 years of age in industrial, urban, and rural communities. in all areas the distribution of clinical symptoms and their severity was similar, but the rate of admission in relation to population was over twice as high in industrial as in other areas. the maximum yearly admission rate occurr ... | 1978 | 359099 |
| incidence of viral antibodies in patients with various forms of cancer. | the results of over 13,500 serological reactions performed in about 3,400 human sera collected from patients with various forms of cancer and from apparently healthy subjects have shown that the humoral immune reactivity of cancer patients as regards their viral antibody response is similar to that of apparently healthy subjects (blood donors or workers exposed to the risk of occupational contact with animal tumor viruses). the authors also remark the presence in the population of antibodies to ... | 1978 | 219592 |
| rsv-induced tumors in chickens: resistance to pulsed current in terminal and non-terminal types. | terminal rous sarcoma virus-induced tumors in chickens had lower resistance to a pulsed current than non-terminal tumors or healthy tissues. this finding suggests the existence of some basic physiological difference between terminal and non-terminal tumors. the terminal tumors may have a higher concentration of mobile ions than either non-terminal types or healthy tissue. | 1978 | 220597 |
| interferon in nasal secretions from infants with viral respiratory tract infections. | interferon levels in nasal secretions of infants under one year of age, and hospitalized with lower repiratory tract disease, were measured during two respiratory infection seasons. in the first year serial secretions from 50 infants with respiratory syncytial virus infection were examined. undetectable or low levels of interferon were found in all samples, and mean levels did not fluctuate significantly in relation to disease and recovery. this was in contrast to anti-rsv iga, which appeared an ... | 1978 | 650342 |
| development of in vitro correlates of cell-mediated immunity to respiratory syncytial virus infection in humans. | groups of infants and children with infections due to respiratory syncytial virus (rsv) were tested at the onset of illness and one, two, and five months later for the presence of rsv-specific cell-mediated immunity, as determined by in vitro lymphocyte transformation (ltf) activity, and for complement-fixing (cf) antibody. an ltf response specific for rsv was observed in 65 % of patients, and the response was largely associated with e-rosette-forming thymus-derived (t) lymphocytes. a significan ... | 1978 | 659924 |
| behavior of respiratory syncytial virus in piglet tracheal organ culture. | piglet tracheal organ cultures were infected with respiratory syncytial virus (rsv) and observed for 21 days. light and immunofluorescence microscopy demonstrated destruction of the ciliated epithelial cells and the presence of viral antigens in the epithelium. virus was shed in high titer for 12--19 days. ciliostasis could be quantitated, and it was shown that several strains of rsv grew and damaged tracheal organ cultures in a similar fashion. a temperature-sensitive mutant of rsv, ts-1, was e ... | 1978 | 712118 |
| control of nosocomial respiratory syncytial viral infections. | we evaluated methods to control the spread of respiratory syncytial virus (rsv) on our infants' ward during a community outbreak of rsv infection. methods included isolation and cohorting of infected infants, strict handwashing, use of gowns, and the cohorting of staff to the ill infants. of 123 infants studied, 36 were admitted with rsv infections. of the remaining 87 contact infants, eight (19%) acquired nosocomial rsv disease. three of the eight developed pneumonia and one died. of the 43 sta ... | 1978 | 724317 |
| interferon production in children with respiratory syncytial, influenza, and parainfluenza virus infections. | to better understand the recovery process of infants with lower respiratory tract disease due to respiratory syncytial virus, the production of interferon by 129 children (ages 10 days to 24 months) with rsv infection was compared to that of 20 children with influenza (ages 1 to 36 months), and 37 children with parainfluenza virus infection (ages 4 to 66 months). interferon assays of 285 nasal washes from children with rsv revealed that interferon production occurred in only 5 (4%) of the childr ... | 1978 | 206677 |
| tumor antigen induction by the envelope-defective bryan strain of rous sarcoma viruses. | chicken, quail, and turkey cells were infected and/or transformed by various avian leukosis or sarcoma oncovirus (alsv) strains as well as by the envelope-defective bryan high-titer strain of rous sarcoma virus [bh-rsv(-)]. all fibroblast-transforming avian sarcoma viruses (asv), including bh-rsv(-), were able to induce the expression of the previously described avian tumor-specific cell-surface antigen(s) (tssa). thus tssa was group-specific for all tested transforming asv. since bh-rsv(-) is a ... | 1978 | 206708 |
| morphological and biochemical differentiation in rsv transformed chick embryo myoblasts. | chick embryo myoblasts have been transformed with a temperature sensitive mutant of rous sarcoma virus (rsv ts68). at permissive temperature (36 degrees c) it is shown that transformed myoblasts have lost their ability to form myotubes as well as to express the biochemical markers of myogenic differentiation. upon a shift to the non-permissive temperature (41 degrees c), the normal program of differentiation is restored; myotubes are formed which express muscle specific proteins. | 1978 | 207445 |
| lysis of rsv-transformed japanese quail cells by a factor from normal quail serum. | normal sera of japanese quails caused lysis of tumor cells from a rous sarcoma virus (rsv)-induced quail tumor (qt cells). other tumor cell lines, including rsv-transformed quail embryo cells and methylcholanthrene-induced quail tumors, were not lysed. this naturally occurring cytolytic factor (nclf) was sensitive to heating at 56 degrees c, zymosan, and inulin, and it required magnesium but not calcium for the expression of its activity. these results suggested that nclf activity was mediated b ... | 1978 | 207650 |
| a virus-induced non-virion antigen specific for transformation at the surface of rsv-transformed fibroblasts. | 1978 | 207990 |