Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| role of moraxella (branhamella) catarrhalis as a respiratory pathogen in children. | during a 12-month surveillance period in 1981-1982, moraxella catarrhalis was detected in cultures from nasopharyngeal aspirates from 76 (17%) of 449 children hospitalized with middle or lower respiratory tract infection. seroconversion to m. catarrhalis was positive in 4 (5%) of the 76 patients with m. catarrhalis present in nasopharyngeal aspirates and in 4 (1%) of 373 patients with a negative finding. although children with respiratory tract infections were often colonized by the organism, th ... | 1992 | 1290865 |
| [clinical manifestation and prognosis of respiratory syncytial virus infection in infants]. | to evaluate the clinical features of respiratory syncytial virus (rsv) infection and relation with bronchial asthma, 233 infants hospitalized for lower respiratory tract infection during winters from 1988 to 1990 were enrolled in this study. rsv antigen was detected from half of them by immunofluorescent antibody test. children with rsv infection showed the characteristic findings as follows; wheeze (71.6%), elevated serum 2-5 as activity, a marker for viral infection, low level of acute phase r ... | 1992 | 1290411 |
| [influenza a infection in children. clinical spectrum and comparison with respiratory syncytial virus infection during the winter 1989-1990]. | respiratory syncytial viral (rsv) infection can be rapidly differentiated from influenza viral infection by immunofluorescence techniques. these tests were used to identify some epidemiological and clinical characteristics of both infections. | 1992 | 1288452 |
| integration, expression and germ-line transmission of foreign growth hormone genes in medaka (oryzias latipes). | gene constructs consisting of human growth hormone (hgh) gene driven by promoter/regulatory sequence of mouse metallothionein (mmt), viral thymidine kinase (vtk), rat cholecystokinin (rcck), or chicken beta-actin (cba) gene were injected into the cytoplasm of fertilized medaka eggs via the micropyle. more than 49% of the injected embryos survived at hatching. up to 26% of the survivors showed integration of the introduced gene construct, as determined by polymerase chain reaction analysis and su ... | 1992 | 1285009 |
| human monoclonal fab fragments derived from a combinatorial library bind to respiratory syncytial virus f glycoprotein and neutralize infectivity. | respiratory syncytial virus (rsv) is the most important cause, throughout the world, of severe viral lower respiratory tract illness in young children. antibodies are known to mediate resistance to rsv infection and illness. we have isolated a number of human monoclonal fab fragments to rsv f glycoprotein from a combinatorial antibody library expressed on the surface of phage. one of these neutralized a wide range of virus isolates, 10 subgroup a and 9 subgroup b isolates, with a titer (60% neut ... | 1992 | 1279672 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| incidence of rs virus infections in premature children's ward. | in the course of two years (1974-76) four outbreaks of acute respiratory disease in the premature children's ward of a prague hospital were studied virologically and clinically. rs virus (rsv) was found to be the aetiological agent. the highest isolation rate of rsv was achieved when using two heteroploid cell lines (l-132 and hep-2 cells) simultaneously. of the 30 children examined, 60% showed a severe course of disease (pneumonia and/or bronchiolitis) while in 40% of the children the disease h ... | 1979 | 575897 |
| antibody-dependent cell-mediated cytotoxicity against cells infected with respiratory syncytial virus: characterization of in vitro and in vivo properties. | an in vitro 51cr release assay for human antibody-dependent cell-mediated cytotoxicity (adcc) against hela cells infected with respiratory syncytial virus (rsv) has been characterized by using leukophoresed and adherent cell-depleted adult lymphocytes. lymphoytes from rsv seronegative children were also competent as effector cells. sera from children with :1) primary and recurrent natural rsv infections, or 2) live attenuated rsv vaccine infection were examined to characterize the behavior of ad ... | 1979 | 571890 |
| experimental respiratory syncytial virus infection in feeder-age lambs. | signs of disease, lesions, and serologic response were seen in six 6-month-old-lambs experimentally inoculated with respiratory syncytial virus (rsv). a transient febrile response, mild hyperpnea, and listlessness were seen. multifocal areas of interstitial pneumonia and bronchiolitis were seen in lambs necropsied during the period of clinical response. a serologic response to rsv was seen in all lambs, and rsv was recovered from five lambs. | 1979 | 525890 |
| clinical and physiological manifestations of bronchiolitis and pneumonia. outcome of respiratory syncytial virus. | the physiological abnormalities and clinical correlates of 32 infants consecutively hospitalized with lower respiratory tract disease from respiratory syncytial virus (rsv) were studied in an attempt to characterized the infant most at risk for the acute and long-term complications of rsv infection. arterial oxygen saturation (sao2) determinations were obtained daily by means of an ear oximeter. on admission all infants were hypoxemic with a mean sao2 of 87% (range, 74% to 95%). the mean of the ... | 1979 | 463835 |
| fibronectin from chicken embryo fibroblasts contains covalently bound phosphate. | fibronectin isolated from cultures of chicken embryo fibroblasts (cef) contains phosphorus linked to serine and threonine by monoester bonds. normal and rous sarcoma virus (rsv)-transformed cells were incubated with [32p]orthophosphate, and fibronectin was isolated from the cell surfaces and conditioned media. 32p was stably associated with fibronectin during immunoprecipitation, sds-polyacrylamide gel electrophoresis, phospholipid solvent extraction, and hot acid but not alkaline treatment. aft ... | 1979 | 457771 |
| the etiologic and epidemiologic spectrum of bronchiolitis in pediatric practice. | to develop a broad understanding of the causes and patterns of occurrence of wheezing associated respiratory infections, we analyzed data from an 11-year study of acute lower respiratory illness in a pediatric practice. although half of the wari occurred in children less than 2 years of age, wheezing continued to be observed in 19% of children greater than 9 years of age who had lower respiratory illness. males experienced lri 1.25 times more often than did females; the relative risk of males fo ... | 1979 | 448557 |
| cell-mediated immune response to respiratory syncytial virus infection: relationship to the development of reactive airway disease. | the possibility that cell-mediated immunity might play a role in the pathogenesis of infection with respiratory syncytial virus was evaluated in a study of 39 infants. infection with rsv was confirmed by identification of virus in nasopharyngeal secretions using immunofluorescence, and by tissue culture infectivity. cmi, as determined by a whole blood lymphocyte transformation technique, was evaluated in samples taken 0 to 10 and 20 to 60 days after the onset of illness. patients diagnosed as ha ... | 1979 | 423016 |
| cell-free and cell-bound antibody in nasal secretions from infants with respiratory syncytial virus infection. | twenty-two infants under 9 months of age hospitalized with bronchiolitis or pneumonia due to respiratory syncytial virus (rsv) were serially sampled to determine the pattern of secretory antibody response. using double labeling techniques, we found several types of immunoglobulin in secretions: cell-free antibody to rsv of the immunoglobulin a (iga), immunoglobulin g (igg), and immunoglobulin m (igm) classes; and immunoglobulins of all three classes bound to rsv-infected cells shed from the nasa ... | 1979 | 422241 |
| reye's syndrome associated with respiratory syncytial virus infection. | an upper respiratory tract infection in a 22-month-old boy was followed by rapid loss of consciousness, hypoglycaemia, uraemia, and death. necropsy examination showed fatty change of liver and kidneys, severe cerebral oedema, bronchiolitis, and endocardial fibroelastosis affecting the left ventricle. immunofluorescence staining showed infection with respiratory syncytial virus (rsv). the clinical and pathological findings were those of reye's syndrome, not previously reported accompanying rsv in ... | 1979 | 420528 |
| detection of respiratory syncytial virus in nasal secretions from infants by enzyme-linked immunosorbent assay. | an enzyme-linked immunosorbent assay (elisa) was developed for detection of respiratory syncytial virus (rsv) in nasal secretions from infants with respiratory disease. rsv was detected in 23 of 29 secretions positive for rsv by tissue culture and in one of 36 samples negative for rsv by tissue culture. the elisa was a simple rapid, and surprisingly sensitive test for identification of rsv infection in infants. | 1979 | 374650 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [fragments of linear unintegrated rous sarcoma virus dna, resulting from digestion with smai restriction endonuclease]. | linear unintegrated dna of schmidt-ruppin rous sarcoma virus, subgroup d (sr-rsv-d), was digested with smai restriction endonuclease, analyzed by agarose gel electrophoresis, "blotted" by southern's method and hybridized with a viral 32p cdna. smai cleaves this dna at five sites, two of which are localized at the ends of the provirus. src and env genes seem not to be restrictied by smai cleavage. | 1979 | 232859 |
| effects of the tumor promoter tpa on the induction of dna synthesis in normal and rsv-transformed rat fibroblasts. | induction of dna synthesis by the tumor promoter tetradecanoyl phorbol acetate (tpa) was studied in a line of cultured rat fibroblasts (rat-1) and their rous sarcoma virus-transformed derivative (rat-1 (rsv)). following serum deprivation for 54 h to achieve quiescence, semiconservative dna replication was measured by incubation of cells in brdurd and fdurd after serum stimulation in the presence or absence of tpa. optimal concentrations of tpa (0.1--0.5 microgram/ml) in serum-free medium induced ... | 1979 | 232527 |
| effect of vitamin a on plasminogen activator synthesis by chick embryo fibroblasts. | low concentrations of vitamin a stimulated plasminogen activator synthesis (pa) in chick embryo fibroblasts (cef). it caused a dose dependent and reversible increase in pa synthesis in both normal cef and cef infected with a temperature sensitive mutant of rous sarcoma virus (rsv-ts68). both induction and deinduction of pa could be inhibited by actinomycin d. vitamin a also accentuated the morphological changes associated with transformation in the rous sarcoma virus infected cells. the effects ... | 1979 | 232460 |
| heterogeneous rna of the prague strain of rous sarcoma virus caused by undiluted passages. | the size of genomic rna in pr-rsv a passaged in chick embryo fibroblasts (cef) or quail embryo fibroblasts (qef) was determined by gel electrophoresis. the results showed that 3 undiluted passages resulted in heterogeneity of rna. the heterogeneity of the smaller incomplete rnas in the virus stock was decreased by diluted passage or cloning, but rna of the b subunit size and a subunit rna of complete genome size were relatively stable. these heterogeneous rnas were characterized by hybridization ... | 1979 | 232236 |
| cell fusion for genetic analysis of two nonconditional rous sarcoma virus replication mutants. | procedures for characterizing replication-defective viruses in nonpermissive mammalian cells were developed and applied to three nonvirogenic rous sarcoma virus (rsv)-transformed mammalian cell lines--b4, a line of bryan virus-transformed hamster cells, and two srd-rsv transformed rat cell lines, lr3/1 and lr3/2. cell fusion was used to study virus complementation. the three cell lines (i) fused with helper virus-infected chicken cells and the host range of the rescued virus examined, (ii) teste ... | 1979 | 232170 |
| transplacental cancerization by rous sarcoma virus. | experimental data obtained in the mouse are presented, pointing to the possibility of transplacental transmission of the genetic information contained in the genome of rous sarcoma virus(rsv), by either intact rsv virions or nucleic acids extracted from infectant suspensions of tumors induced by the carr(ziber) on bryan rsv strains. | 1979 | 231860 |
| the influence of host adaptation of rous sarcoma virus on the transfecting activity of its dna provirus. | mammalian cells transformed with either prague strain rous sarcoma virus of subgroup c (xc cells) or schmidt-ruppin strain rous sarcoma virus of subgroup d (rsch cells) yielded virus upon fusion with chick cells. virus was also rescued by transfection of dna from these cells on to chick cells. however, virus rescue did not occur upon transfection of duck cells, and fusion with duck cells led to virus rescue only from rsch and not from xc cells. to investigate this restriction on the duck cells t ... | 1979 | 230300 |
| studies of the effect of chloramphenicol, ethidium bromide and camptothecin on the reproduction of rous sarcoma virus in infected chick embryo cells. | a function for mitochondria in the reproduction of rous sarcoma virus (rsv) in chronically and newly infected chick embryo cells was studied by using chloramphenicol and ethidium bromide. chloramphenicol (cam) and ethidium bromide (eb) were both shown to decrease the rate of growth of infected chick embryo cells and to inhibit the synthesis of mitochondrial macromolecules. both drugs however had little or no effect on the incorporation of labelled leucine, thymidine and uridine into total cellul ... | 1979 | 230286 |
| clones of cells from a human embryo lung: their growth and susceptibility to respiratory viruses. | colonies of cells were obtained from human fetal lung tissue and exposed to recently isolated respiratory viruses. there was a considerable variation in the number of rounded cells found in different colonies exposed to rhinovirus types 2 and 9 (rv2 and 9), human coronavirus 229e (hcv), adenovirus type 3 (ad3) and respiratory syncytial virus (rsv). smaller colonies had more rounded cells than larger colonies. clones were established from 9 out of 11 colonies. they varied in their rate of growth ... | 1979 | 229795 |
| genetic nature of regression of rous sarcoma virus-induced tumors in crosses of regional poultry research laboratory lines 6 and 7(2). | regional poultry research laboratory (rprl) inbred lines 6(1), 6(3), and 7(2) and f1, f2, and reciprocal backcross progenies of these lines were used to investigate host-gene effects upon the regression of rous sarcoma virus (rsv)-induced tumors. lines 6(1) and 6(3) were susceptible to subgroup a and c lymphoid leukosis (ll) viruses and line 7(2) was resistant to subgroup a but was segregating for susceptibility to subgroup c ll virus. viruses of rsv subgroups a and c were used. lines 6(1), 6(3) ... | 1979 | 229477 |
| restriction of patching of bound concanavalin a after incorporation of arachidonic acid into the plasma membrane of virally transformed fibroblasts. | topographical distribution of concanavalin a binding sites (cabs) was studied in two lines of virally transformed fibroblasts as a function of fatty acid composition. fatty acid composition was manipulated by incubating cells in fatty acid, atp, coa, and delipidated fetal calf serum (fcs). vlm cells grown in medium containing 5% fcs have a clustered cabs distribution. plasma membrane vesicles (pmvs) derived from these cells have an arachidonate content of 1.7%. elevation of pmv arachidonate to 1 ... | 1979 | 229111 |
| continuous lines of rsv-transformed embryo cells and peritoneal macrophages of japanese quails. | four continuous lines of rsv-transformed quail cells were established; qerc-31f and qerc-31n cells derived from quail embryo cells and perp and pery cells from adult quail peritoneal macrophages. marked morphological difference was noted between qerc-31f and qerc-31n; the former showed fusiform shape and the latter nodular shape. both perp and pery showed macrophage-like morphology with phagocytic capacity. all four cell lines contained gs antigen and gp 85. production of transforming virus was ... | 1979 | 224231 |
| comparative study of tumor-specific transplantation antigens of mc-29 chicken hepatoma and rous sarcoma virus-induced sarcomas in mice. | immunization of cbat6t6 mice with mc-29 hepatoma antigen did not change the take of rous sarcoma virus, schmidt-ruppin strain [rsv(sr)] mouse tumors after sc transplantation. immunization with mc-29 hepatoma antigen only slightly increased the average survival time of the mice and significantly decreased tumor growth only at the minimal lethal dose level. immunization of mice with mc-29 hepatoma antigen and immunization with chicken rous sarcoma gave similar results; both elicited much less tran ... | 1979 | 224208 |
| plasma membrane phosphoproteins in normal and rous sarcoma virus transformed chick embryo fibroblasts: characterization by in vitro phosphorylation. | plasma membranes isolated from normal and rsv transformed chick embryo fibroblasts were phosphorylated in vitro using endogenous protein kinase and atp (gamma32p) and the labeled phosphoproteins were analyzed by sds-page. a number of protein phosphorylation changes were observed following transformation, however in most cases they were relatively small quantitative differences. the four major changes were in proteins of 47,000, 58,000, 75,000 and 135,000 daltons. decreased phosphorylation of the ... | 1979 | 224069 |
| oncornavirus modification of the golgi apparatus. | two virus system, the friend leukaemia virus (flv) and the rous sarcoma virus (rsv), were introduced into tissue both in vitro and in vivo. both brought about substantial modification of the activity of the golgi apparatus detectable as such by specific radioautographic studies. this modification was accompanied by changes in the development and social behaviour of the cells with some differences being detectable between the in vivo and in vitro studies. | 1978 | 223815 |
| assays for endogenous and exogenous lymphoid leukosis viruses and chick helper factor with rsv(--) cell lines. | japanese quail cells transformed by the envelope-defective bryan high-titer strain of rous sarcoma virus [r(-)q] were used as a source of the rous sarcoma virus genome in three kinds of assays. (i) the simplest and most sensitive assay for infectious, endogenous viruses of the chicken belonging to subgroup e involved infection of a mixture of r(-)q cells and turkey cells with the sample and assay of supernatants of these cells for focus formation on subgroup e susceptible cells. (ii) inactivated ... | 1979 | 222685 |
| neural crest cells: temperature-dependent transformation by rous sarcoma virus. | cranial neural crest cells from chick embryos, when cultured under appropriate conditions, differentiate after approx. 1 week into pigmented cells. neurol crest cells were infested with a mutant (rsv-bh-ta) of the bryan 'high titer' strain of rous sarcoma virus on the second day of culture before the cells were morphologically differentiated, or later after they became pigmented. cells infected and maintained at the temperature permissive for transformation (37 degrees c) proliferated rapidly co ... | 1979 | 222481 |
| specific rna sequences of rous sarcoma virus (rsv) recovered from tumors induced by transformation-defective rsv deletion mutants. | 1979 | 222048 | |
| messenger activity of virion rna for avian leukosis viral envelope glycoprotein. | an intracellular assay for viral envelope glycoprotein (env) messenger was employed to analyze the rna from virus particles of rous-associated virus type 2. for this assay rna was microinjected into cells infected by the env-deficient bryan strain of rous sarcoma virus [rsv(-) cells]. only when the injected rna could be translated by the recipient cells to produce viral envelope glycoprotein was the env deficiency of the rsv(-) cells complemented, enabling them to release focus-forming virus. rn ... | 1979 | 221682 |
| 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 |
| 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 |
| observations on outbreaks of respiratory disease in calves associated with parainfluenza type 3 virus and respiratory syncytial virus infection. | in four outbreaks of indoor calf pneumonia, dyspnoea was a prominent clinical finding. at necropsy it was associated with pneumonia involving the cranial lobes of the lung and severe pulmonary emphysema. histological examination of lung tissue revealed bronchiolitis and alveolitis with alveolar epithelial cell hyperplasia and multinucleate syncytium formation. intraalveolar haemorrhage, intra-alveolar oedema and hyaline membrane formation were also noted. in all cases parainfluenza type 3 (pi3) ... | 1979 | 219584 |
| 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 |
| characterization of some isolates of newly recovered avian sarcoma virus. | we previously reported the isolation of a newly recovered avian sarcoma virus (rasv) from tumors of chickens injected with transformation-defective (td) mutants of the schmidt-ruppin strain of rous sarcoma virus (sr-rsv). in this paper, we present further biological and biochemical characterization of the recovered sarcoma viruses. high titers of rasv's were generally obtained by cocultivation of tumor cells with normal chicken embryo fibroblasts or by homogenization of tumor tissues. most rasv ... | 1979 | 219237 |
| src gene product from different strains of avian sarcoma virus: kinetics and possible mechanism of heat inactivation of protein kinase activity from cells infected by transformation-defective, temperature-sensitive mutant and wild-type virus. | sera from certain rabbits bearing schmidt-ruppin strain rous sarcoma virus (rsv)-induced tumors precipitated p60(src) from chicken cells transformed by the homologous virus as well as by other strains [prague strain rsv, bryan high-titer strain rsv, and bratislava 77 strain of avain sarcoma virus (asv)], the molecular weights (m(r)s) ranging from 60,000 to 64,000. the p60(src) immunoprecipitated from cells transformed by each of these strains incorporated [gamma-(32)p]atp into the m(r) 53,000 su ... | 1979 | 218225 |
| characterization of the genomic rna from a rous sarcoma virus mutant temperature sensitive for cell transformation. | we have found that the la23 t/s mutant of rous sarcoma virus (phenotype prague b), even when passaged repeatedly at high multiplicity of infection, does not give rise to transformation defective deletion mutants comparable to those derived from rsv. in view of this fact and of the high rate of production of this mutant at 41 degrees c, we have undertaken a detailed analysis of the genome of this virus by ordering all large t1 oligonucleotides and by determining their nucleotide sequences. the re ... | 1979 | 218172 |
| immunofluorescence on avian sarcoma virus-transformed cells: localization of the src gene product. | the localization of the avian sarcoma virus src gene product (termed p60src) was examined by indirect immunofluorescence in cells transformed by the schmidt-ruppin strain of rous sarcoma virus, subgroup d (sr-rsv-d). antiserum to p60src was obtained from rabbits bearing sr-rsv-d-induced tumors, and immunofluorescence was performed on chicken embryo fibroblasts (cef) transformed with sr-rsv-d, as well as normal rat kidney (nrk) cells transformed by the same virus (termed sr-rk cells). both aceton ... | 1979 | 217542 |
| lack of correlation between tumorigenicity and level of plasminogen activator in fibroblasts transformed by rous sarcoma virus. | we have previously isolated, from agar suspension culture, clones of chicken embryo fibroblasts transformed by b77 and prague strains of rous sarcoma virus (rsv) that varied in the expression of plasminogen activator activity [wolf, b. a. & goldberg, a. (1976) proc. natl. acad. sci. usa 73, 3613-3617]. all of the clones exhibited an altered cellular morphology, an increased rate of sugar transport, and a high efficiency of colony formation in agar suspension regardless of the level of plasminoge ... | 1978 | 217007 |
| systemic and topical use of poly i.c. in treatment of generalized neonatal herpes simplex infection with severe ocular involvement. | a case of neonatal herpes simlex virus (rsv) encephalitis with severe ocular manifestation treated by topical systemic and intrathecal interferon inducer, poly ic (polyriboinosinic acid-polyribocytidylic acid) is reported. prior to the administration of poly ic, no interferon could be detected neither in blood nor in csf and vesicular fluid from conjunctiva. intravenous administration of the drug initiated measurable levels in blood and tears, but not in csf. however, intrathecal injection induc ... | 1978 | 216790 |
| nucleotide sequence relationships between the genomes of an endogenous and an exogenous avian tumor virus. | we have used mapping of large t1 oligonucleotides to examine the genome of rous-associated virus-o (rav-o), an endogenous virus of chickens, and to compare it with that of prague strain rous sarcoma virus, subgroup b, (pr-rsv-b), an exogenous sarcoma virus. to extend the sensitivity of such comparisons, we have developed a system of nucleic acid hybridization and hybridization-competition combined with fingerprinting. this method allows us to estimate the relative degree of relatedness of variou ... | 1978 | 215788 |
| the kinetics of synthesis of infectious unintegrated virus dna in rous sarcoma virus infected chicken cells. | infectious virus nucleic acids were extracted from the hirt supernatant of chicken embryo fibroblasts infected for different times with the schmidt-ruppin strain of rous sarcoma virus (rsv). infectious dna and dna-rna hybrid molecules could be recovered from 6 h after infection in experiments using 1.5 x 10(9) infected cells. only small amounts of infectious virus dna could be purified 6 h after infection whereas at 24 h approximately one infectious dna molecule could be recovered for each input ... | 1979 | 215710 |
| plasminogen activator in chick embryo muscle cells: induction of enzyme by rsv, pma and retinoic acid. | to explore the generality of the effects of sarcoma viruses, tumor-promoting phorbol esters and retinoic acid, we have studied plasminogen activator production in differentiating chick myogenic cultures. although slightly higher than in chick fibroblast cultures, the level of spontaneously synthesized enzyme is low; it reaches a peak shortly after maximum cell fusion has been completed and then declines. rous sarcoma virus (rsv) transformation of differentiating myotubes was accomplished by infe ... | 1978 | 215322 |
| metabolism of acetylcholine receptor in chick embryo muscle cells: effects of rsv and pma. | we have investigated some aspects of the metabolism of the integral membrane protein acetylcholine receptor (achr) in normal and transformed cultures of chick embryo muscle cells. turnover of achr in control muscle cell cultures was compared with turnover in cultures infected and transformed by a temperature-sensitive mutant of rous sarcoma virus (rsv) and with cultures treated with the tumor promoter phorbol myristate acetate (pma). the parameters of achr metabolism were estimated using 125i-al ... | 1978 | 215321 |
| analysis of rous sarcoma virus (rsv) rna structure by means of specific nucleases. | 1978 | 214951 | |
| characterization of rous sarcoma virus src gene products synthesized in vitro. | the cell-free synthesis of three major proteins from virion rna of nondefective rous sarcoma virus (rsv), but not from rna of transformation-defective deletion mutants, has been observed. the apparent molecular weights of these transformation-specific proteins are approximately 60,000 (60k), 25k, and 17k. tryptic maps of methionine-containing peptides revealed the 17k, 25k, and 60k proteins to be overlapping in sequence. however, only partial homology was observed between the 17k, 25k and 60k pr ... | 1978 | 214578 |
| transfer of duck cell dna sequences to the nucleus of 3t3 cells by rous sarcoma virus. | peking duck cell nuclear dna has no complementarity to rna of prague c rous sarcoma virus (rsv). upon infection of peking duck cells by prague c rsv, polynucleotide sequences complementary to peking duck cell nuclear dna can be detected in the high molecular weight rna from progeny peking duck cell passaged rsv (rsvpd) by rna.dna molecular hybridazation. when 3t3 cells are subsequently infected by rsvpd, polynucleotide sequences complementary to peking duck cell nuclear dna can be detected in th ... | 1978 | 212741 |
| large-scale production, concentration and purification of rous sarcoma virus in tissue culture. | a method is described for long-term standard production of purified virus from cultures of pr-rsv-c-transformed chicken cells. the mean yields were 4.91 mg of purified virus per liter of culture medium. cells were grown in long-term cultures for 26 weeks. a combination of polyethylene glycol 6 000 precipitation and zonal centrifugation has been found satisfactory for virus concentration and purification. | 1978 | 212330 |
| reversion of temperature sensitive transformation mutants of rous sarcoma virus and its effect on the expression of tumour specific surface antigen. | rous sarcoma virus (rsv) mutants, which bear temperature sensitive (ts) defects in both the maintenance of cell transformation and the expression of tumour specific cell surface antigen(s) (tssa), have yielded a number of revertants. in seven revertants studied, the acquisition of wild type transforming capacities is always accompanied by a wild type tssa expression. this strongly indicates that transformation and tssa expression in rsv are affected by the same mutation. | 1978 | 211200 |
| regulation of expression and chromosomal subunit conformation of avian retrovirus genomes. | we have investigated the copy number, chromosomal subunit conformation and regulation of expression of integrated avian retrovirus genomes. our results indicate that there are approximately two copies of the endogenous viral genomes (rav-o) per haploid cell genome in uninfected chick embryo fibroblasts (cef) and red blood cells (rbc). the copy number and subunit conformation (as measured by dnaasel sensitivity) of the rav-o genomes are independent of the level of expression of these viral dna se ... | 1978 | 210959 |
| differential expression of rous sarcoma virus-specific transformation parameters in enucleated cells. | chicken embryo fibroblasts transformed with the ta and ts68 mutants of rous sarcoma virus (rsv) were enucleated and studied for their capacity to express reversibly the transformed phenotype in response to temperature changes. after shift to the permissive temperature (35 degrees c), the cytoplasts acquired a transformed morphology and displayed characteristic ruffles and microvilli at their surface. as detected by immunofluorescence, they also lost their actin filament cables and exhibited char ... | 1978 | 210958 |
| brain tumors induced in hamsters by intracerebral inoculation of sr-rsv-infected embryonic brain cells. | brain tumors were induced in syrian hamsters by intracerebral inoculation of brain cells which were obtained from 12-day old syngeneic hamster and infected with schmidt-ruppin strain of rous sarcoma virus (sr-rsv) in vitro. a total of 212 tumors were developed in all 25 recipients within 19 to 125 days after transplantation. on the basis of light and electron microscopic study, they were classified into four main groups: astrocytoma (45.8%), pleomorphic glioma (50.0%), sarcoma (3.8%), unclassifi ... | 1978 | 210620 |
| [immunological and structural properties of rous sarcoma virus-transformed and tumor cells]. | we compared the capacity of both normal and rous sarcoma virus (rsv)-transformed chicken embryo fibroblast (cef) cells as well as rous sarcoma (rs) tumor cells to serve as targets in anti-tumor immunity assays. these studies showed that sera from tumor-bearing donors were able to stain transformed cef more efficiently than rs cells as detected by immunofluorescence. in contrast, antiserum against the major viral glycoprotein, gp 85, stained a higher percentage of rs than transformed cells. norma ... | 1978 | 209500 |
| study of group-specific proteins in mammalian cells transformed by rous sarcoma virus. | lysates of various mammalian rsv-transformed cells labelled with 35s-methionine were tested for the presence of gs proteins and for the size of these molecules by means of antisera, using sodium dodecyl sulphate--polyacrylamide slab gel electrophoresis. in no case was the presence of gs proteins detected in the analyzed immunoprecipitates; only in rsh-mix cells a quantitative difference in the contrast of a 70 000-molecular weight protein was found. the autoradiograms of simultaneously tested im ... | 1978 | 208874 |
| a virus-induced non-virion antigen specific for transformation at the surface of rsv-transformed fibroblasts. | 1978 | 207990 | |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| intracellular precursors to the major glycoprotein of avian oncoviruses in chicken embryo fibroblasts. | a 96,000-dalton glycoprotein, p(96), was present in cell extracts obtained from gs-chf- chicken embryo fibroblasts infected with the avian rna tumor viruses rous-associated virus-2 subgroup b (rav-2) and the schmidt-ruppin strain of rous sarcoma virus subgroup a (sr-rsv-a), as well as from uninfected gslchf+ (he) cell extracts. it was not found in cell extracts from uninfected gs-chf- or gs+chf+ (hh) cells, nor from gs-chf- cells infected with envelope-deficient bryan high-titer rous sarcoma vir ... | 1978 | 205673 |
| effects of dexamethasone on the morphogenesis of two mutants of rous sarcoma virus. | japanese quail cells transformed by the replication-defective, bryan high-titer strain of rous sarcoma virus, bh rsv(-)q, clone 3, revealed intracytoplasmic a-type particles after dexamethasone treatment. in the absence of dexamethasone, or when superinfected with a helper virus in the presence or absence of dexamethasone, no such particles were observed. chick embryo cells (cec) infected with a temperature-sensitive sarcoma virus mutant, la 334, coordinately defective for transformation and vir ... | 1978 | 204599 |
| multiple forms of sarc gene proteins from rous sarcoma virus rna. | in a previous study we were able to identify two proteins of 25,000 and 18,000 daltons that were made from rna of transforming virions of rous sarcoma virus (rsv) and that were missing from the translation products of a transformation-defective deletion mutant of rsv. in the present study we have separated rsv virion rna on sucrose gradients and have determined that the two putative sarc gene products are synthesized as doublets from an mrna of approximately 18 s. there also appear to be several ... | 1978 | 203938 |
| quantitation and localization of rous sarcoma virus-specific rna in transformed and revertant field vole cells. | hybridization analysis of rna from transformed clones of rous sarcoma virus (rsv)-infected field vole cells and revertant subclones indicated the presence of similar amounts of viral-specific rna in both cell types. employing both a relatively uniform and representative complementary dna probe and genomelength complementary dna, we have demonstrated that the majority of rsv proviral dna is transcribed into viral-specific rna in both transformed and revertant clones. the viral-specific rna is pre ... | 1978 | 203719 |
| decreased alkaline phosphatase in cells transformed by rous sarcoma virus. | chick embryo cells transformed by either of two strains of rous sarcoma virus (bryan high titer or schmidt-ruppin) have low levels of alkaline phosphatase activity compared with nontransformed chick embryo cells. essentially no differences in acid phosphatase activity were observed between these transformed and nontransformed cells. a virus mutant, rsv-bh-ta, induces temperature-dependent transformation in infected cells. at 41 degrees, the transformation-nonpermissive temperature, alkaline phos ... | 1978 | 202384 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |