| characteristics of avian sarcoma virus strain prciv and comparison with strain prcii-p. | | 1981 | 6270882 |
| evaluation of the lipid-soluble diaminopyrimidines, metoprine and etoprine, in the avian sarcoma virus rat glioma model. | using the avian sarcoma virus (asv) rat glioma model, we have evaluated the in vivo effectiveness of two lipid-soluble folate antagonists, metoprine (ddmp) and its 6-ethyl analog etoprine. when adult fischer 344 rats, which were previously inoculated with asv as newborns, received ddmp ip, high levels of this drug accumulated in both normal and gliomatous brain tissue, as well as in lung and liver. when animals bearing asv-induced gliomas were treated with ddmp or etoprine with or without citrov ... | 1982 | 6272992 |
| rapid and reversible reduction of junctional permeability in cells infected with a temperature-sensitive mutant of avian sarcoma virus. | the transformed or normal phenotype of cultured normal rat kidney cells infected with a temperature-sensitive mutant of avian sarcoma virus is conditional on the temperature at which the cells are grown. using dye injection techniques, we show that junction-mediated dye transfer is also temperature-sensitive. the extent and rate of transfer between infected cells grown at the transformation-permissive temperature (35 degrees c) is significantly reduced when compared to infected cells grown at th ... | 1981 | 6273447 |
| long-term preservation of transfecting activity of avian sarcoma proviral dna. | the integrated proviral dna of avian sarcoma virus (asv) in host cell chromosomes has been isolated and stored in saline sodium citrate (ssc) solution or in 70% ethanol at 4 degrees c in a refrigerator over 4 years. this dna was assayed by transfection of chick embryo cells(cec). the biological activity of cellular transformation by the stored dna was compared with that of a fresh isolate of the proviral dna. the efficiency of the transfection by each dna was almost the same. | 1981 | 6274167 |
| the src gene product (pp60 src) of avian sarcoma virus rapidly induces dna synthesis and proliferation of calcium-deprived rat cells. | | 1981 | 6274343 |
| a cellular protein phosphorylated by the avian sarcoma virus transforming gene product. | | 1981 | 6274751 |
| prcii, a representative of a new class of avian sarcoma viruses. | the poultry research center virus ii (prc ii) is a replication-defective avian sarcoma virus with envelope determinants of the a and b subgroups. in nonproducing cells transformed by prcii the products of the replicative genes gag, pol, and env are not demonstrable, but a single polyprotein of mr 105,000 (p105) can be detected. p105 contains peptides of the gag proteins p19 and p27 plus transformation-specific sequences. it does not contain peptides of gpr95env of pr180gag-pol (with the possible ... | 1981 | 6274755 |
| integration of rous sarcoma virus dna into chicken embryo fibroblasts: no preferred proviral acceptor site in the dna of clones of singly infected transformed chicken cells. | we analyzed retroviral integration into a host genome by using avian sarcoma virus infection of natural target cells under conditions where secondary integration via virus spread was inhibited. this was accomplished by using the noninfectious pol- env- alpha variant of the bryan high-titer strain of rous sarcoma virus. a total of 12 independent bryan high-titer rous sarcoma virus-transformed chicken embryo fibroblast clones were obtained and mapped by using restriction endonucleases. provirus-ce ... | 1981 | 6275096 |
| structure and phosphorylation of the fujinami sarcoma virus gene product. | the fujinami avian sarcoma virus (fsv) transforming gene product, p140, is a fusion protein which contains both gag-related and fsv-specific methionine-containing tryptic peptides. the virion protease p15 cleaved p140 into two fragments: an n-terminal 33k fragment which contained all but one of the gag-related tryptic peptides and a c-terminal 120k fragment which contained all of the fsv-specific tryptic peptides. the 33k gag-related fragment from p140 phosphorylated in fsv-transformed cells con ... | 1981 | 6275111 |
| host-dependent phosphorylation and kinase activity associated with vesicular stomatitis virus. | among the protein kinases associated with vesicular stomatitis virus (vsv), one was identified by immunoprecipitation to be pp60src, the transformation-specific product coded for by avian sarcoma virus, or its endogenous cellular homolog. this activity phosphorylated only tyrosine. pp60src was enriched in the membranes, whereas the serine- and threonine-specific kinases were concentrated with viral cores. the content of pp60src in vsv can be manipulated by growing vsv in different host cells. mo ... | 1982 | 6277933 |
| molecular mechanisms involved in morphological variation of avian sarcoma virus-infected rat cells. | | 1982 | 6278722 |
| a temperature-sensitive lesion affecting levels of transformation-specific viral rna in a mutant of avian sarcoma virus prcii. | | 1982 | 6278732 |
| genome structure of the defective avian sarcoma virus prciv. | | 1982 | 6278733 |
| immune selection of tumor cell variants in chickens bearing tumors induced by avian sarcoma virus. | we have compared avian sarcoma cells, cultured from tumors at various stages of growth, in terms of their ability to synthesize infectious progeny virus and to express antigens that are reactive with the sensitized lymphocytes of tumor-bearing hosts. cell-mediated immunity in chickens bearing tumors induced by avian sarcoma viruses was monitored by each of a target cell cytotoxicity test and an antigen-driven lymphocyte stimulation assay. our results show that it is only those tumor cells which ... | 1982 | 6279281 |
| synthetic peptide substrates for a tyrosine protein kinase. | immunoprecipitates containing the transforming protein of the avian sarcoma virus, y73, together with its associated tyrosine-specific protein kinase, have an activity which will phosphorylate the synthetic peptide lys-leu-ile-glu-asp-asn-glu-tyr-thr-ala-arg at the tyrosine residue. this peptide corresponds to 10 out of 11 amino acids surrounding the phosphorylated tyrosine in both pp60src and p90, the transforming proteins of rous sarcoma virus and y73 virus, respectively. the apparent km for p ... | 1982 | 6279650 |
| avian sarcoma virus y73 genome sequence and structural similarity of its transforming gene product to that of rous sarcoma virus. | from the complete nucleotide sequence of the genome of the avian sarcoma virus y73, we have predicted amino acid sequence of p90 gag-yes, the product of the transforming gene. contrary to previous evidence from molecular hybridization studies p90 gag-yes was found to have much homology with the transforming gene product p60 src of rous sarcoma virus, suggesting that the cellular counterparts of the two (c-yes and c-src) originated from a common prototype sequence. | 1982 | 6281656 |
| experimental allergic encephalomyelitis in lewis rats bearing avian sarcoma virus-induced brain tumors. | lewis rats bearing avian sarcoma virus (asv)-induced brain tumors were injected with guinea pig spinal cord emulsion and complete freund's adjuvant to determine if they remained susceptible to induction of experimental allergic encephalomyelitis (eae). the incidence of eae among rats with small, and moderate sized gliomas was similar to non-tumor-bearing controls (p less than 0.5; p less than 0.9) while 18 of 24 (75%) animals with large gliomas developed eae as compared to 31 of 33 (93%) control ... | 1982 | 6282929 |
| changes in amino-terminal sequences of pp60src lead to decreased membrane association and decreased in vivo tumorigenicity. | we have suggested previously that the amino-terminal 8 kilodaltons of pp60src may serve as a structural hydrophobic domain through which pp60src attaches to plasma membranes. two isolates of recovered avian sarcoma viruses (rasvs), 1702 and 157, encode pp60src proteins that have alterations in this amino-terminal region. the rasv 1702 src protein (56 kilodaltons) and the 157 src protein (62.5 kilodaltons) show altered membrane association, and fractionate largely as soluble, cytoplasmic proteins ... | 1982 | 6284379 |
| expression of the prc ii avian sarcoma virus genome. | we found that the genomic rna of the replication-defective avian sarcoma virus prc ii was 4.0 kilobases long. a northern blot analysis of the viral rnas present in prc ii-transformed cells showed that the prc ii genome was expressed as a single 4.0 kilobase mrna species. in vitro translation of polyadenylic acid-containing 70s virion rna yielded two highly related proteins of 110,000 and 105,000 daltons (p110 and p105), which were synthesized from messenger activity that sedimented as expected f ... | 1982 | 6284969 |
| genetic structure and transforming sequence of avian sarcoma virus ur2. | we have recently shown that a newly isolated avian sarcoma virus, ur2, is defective in replication and contains no sequences homologous to the src gene of rous sarcoma virus. in this study, we analyzed the genetic structure and transforming sequence of ur2 by oligonucleotide fingerprinting. the sizes of the genomic rnas of ur2 and its associated helper virus, ur2av, were determined to be 24s and 35s, respectively, by sucrose gradient sedimentation. the molecular weight of the 24s ur2 genomic rna ... | 1982 | 6284974 |
| molecular cloning of the fujinami sarcoma virus genome and its comparison with sequences of other related transforming viruses. | full-length proviral dna of fujinami sarcoma virus (fsv) of chickens was molecularly cloned and characterized. an analysis of fsv dna integrated in mammalian cells showed that restriction endonuclease saci has a single cleavage site on fsv dna. unintegrated closed circular fsv dna obtained from newly infected cells was linearized by digestion with saci and cloned into lambdagtwes.lambdab. the following three different molecules were isolated: fsv-1 (4.4 kilobases [kb]) and fsv-2 (4.7 kb), which ... | 1982 | 6284986 |
| accumulation of spliced avian retrovirus mrna is inhibited in s-adenosylmethionine-depleted chicken embryo fibroblasts. | the synthesis and processing of b77 avian sarcoma virus rna in infected chicken embryo fibroblasts was followed in the presence and absence of cycloleucine, a competitive inhibitor of the synthesis of s-adenosylmethionine and thus an inhibitor of rna methylations. an increase in the steady-state levels of genome-length rna and a decrease in the steady-state levels of subgenomic rna molecules were obtained in the s-adenosylmethionine-depleted avian sarcoma virus-infected cells after 24 h of treat ... | 1982 | 6285005 |
| [the effect of sodium nitrite on rats infected with avian sarcoma virus]. | a potential effect of sodium nitrite was studied as exerted on carcinogenesis elicited by the avian sarcoma virus in the body of rats. in the case of the infection of the rats with indefective avian sarcoma virus b77 (bratislava strain; id50 10-25/0.1 ml) and i. p. inoculation of sodium nitrite, great mortality occurred already on the 20th day p. i. on the 125th day p. i. the cumulative mortality in this group was 76.92%; on the other hand, in the control groups (rats inoculated with sodium nitr ... | 1982 | 6285583 |
| correlations of inheritance and expression between a tumor gene and the cellular homolog of the rous sarcoma virus-transforming gene in xiphophorus. | neoplastic transformation of pigment cells in the teleostean fish xiphophorus is mediated by a cellular oncogene (tu). normally. tu is suppressed by multiple regulating genes (r). depending on impairment and loss of r genes, tu is permitted to express itself phenotypically. in the pigment cell system, different degrees of tu expression lead to small spots of transformed cells or to benign or malignant melanoma. all neoplastic and nonneoplastic cells of all xiphophorus genotypes tested thus far a ... | 1982 | 6286105 |
| cytoskeleton of rat neoplastic cells of spontaneous origin and their derivatives after supertransformation with avian sarcoma virus b77 in vitro. | changes in the distribution of actin-containing cables (microfilament bundles), microtubules and fibronectin were studied by immunofluorescence in four rat neoplastic cell lines and compared with those of normal rat fibroblasts. no changes in the organization of microtubules were seen. a network of fibronectin filaments was observed only in normal fibroblasts whereas a few short fibronectin fibres were observed in cultures of all tumour cells. the actin-containing microfilament bundles in lw13k2 ... | 1982 | 6286374 |
| alternation in malignancy of rat spontaneous tumour cells after in vitro supertransformation by asv. | neoplastic cells from a spontaneous mammary carcinosarcoma (sam-lew) of lew/cub rats and spontaneously in vitro transformed lewis rat embryo fibroblasts (lw13k2) were infected in vitro and transformed with avian sarcoma virus b77. clones of b77 super-transformants (samb774, k2b773) were isolated and tested in vitro and in vivo for the rescue of infections b77 virus with positive results. these virogenic b77 supertransformants were then tested in the immunogenetic test of malignancy established ... | 1982 | 6286375 |
| effects of dexamethasone on antigen expression and virus production in avian sarcoma virus-transformed cells. | we studied the effects of dexamethasone on virus production and antigen expression in avian retrovirus-infected chick embryo fibroblast (cef) cells. the presence of specific receptors for this hormone in both normal and infected cef cells could only be demonstrated using cultures that were at or near confluence. dexamethasone, while not toxic to the cells, exerted a growth-retarding influence when employed at concentrations of 10(-8) or 10(-9) m. these same concentrations of hormone were inhibit ... | 1982 | 6286695 |
| immune stimulation of sensitized chicken lymphocytes by avian retrovirus proteins. | peripheral blood lymphocytes of chickens bearing tumours induced by avian sarcoma virus can be specifically stimulated to divide by the crude culture fluids of virus-infected cells. in this communication, we show that relevant antigenic activity apparently resides in each of the internal virus proteins p15 and p27. the ability of infectious culture fluids to be mitogenic for sensitized lymphocytes is greatly reduced following treatment with antibodies specific for either total avian myeloblastos ... | 1982 | 6286858 |
| sequence of the long terminal repeat and adjacent segments of the endogenous avian virus rous-associated virus 0. | rous-associated virus 0 (rav-0), an endogenous chicken virus, does not cause disease when inoculated into susceptible domestic chickens. an infectious unintegrated circular rav-0 dna was molecularly cloned, and the sequence of the long terminal repeat (ltr) and adjacent segments was determined. the sequence of the ltr was found to be very similar to that of replication-defective endogenous virus ev-1. like the ev-1 ltr, the rav-0 ltr is smaller (278 base pairs instead of 330) than the ltrs of th ... | 1982 | 6286997 |
| comparison between the viral transforming gene (src) of recovered avian sarcoma virus and its cellular homolog. | recovered avian sarcoma viruses are recombinants between transformation-defective mutants of rous sarcoma virus and the chicken cellular gene homologous to the src gene of rous sarcoma virus. we have constructed and analyzed molecular clones of viral deoxyribonucleic acid from recovered avian sarcoma virus and its transformation-competent progenitor, the schmidt-ruppin a strain of rous sarcoma virus. a 2.0-megadalton ecori fragment containing the entire src gene from each of these clones was sub ... | 1981 | 6287213 |
| the changes in proviral chromatin that accompany morphological variation in avian sarcoma virus-infected rat cells. | the clone all of avian sarcoma virus b77-infected rat-1 cells comprises both morphologically normal and morphologically transformed derivatives. transformed subclones, in which virus-specific rna is readily detectable, contain a provirus that is very sensitive to dnase 1 digestion of chromatin, and show dnase 1 hypersensitive sites at the 5' end of the provirus and in 5' flanking cell dna. normal subclones with no detectable virus-specific rna, whether infected cells that have never been transfo ... | 1982 | 6287428 |
| phenotypic differences between tumor cells derived from different stages of neoplastic growth. | under conditions employed in our laboratory, tumors which are induced by avian sarcoma virus (asv) usually grow progressively for several weeks and then regress. in order to further understand the basis for tumor regression in this model, we compared avian sarcoma cells which were cultured from tumors at different stages of development in terms of various phenotypic properties. the results indicate that tumor cells which are derived from progressively-growing sarcomas are rapidly growing, produc ... | 1982 | 6288392 |
| effects of adrenal cortical steroids and osmotic blood-brain barrier opening on methotrexate delivery to gliomas in the rodent: the factor of the blood-brain barrier. | the effect of adrenal cortical steroids and osmotic blood-brain barrier modification on methotrexate delivery to normal and glioma-bearing rats was studied. in animals with the avian sarcoma virus-induced glioma, osmotic blood-brain barrier modification resulted in significantly increased delivery of methotrexate to the tumor-bearing hemisphere (including the tumor, the brain around the tumor, and the brain distant to the tumor), compared to the nonmodified hemisphere or to control animals. the ... | 1982 | 6289301 |
| isolation of 16l virus: a rapidly transforming sarcoma virus from an avian leukosis virus-induced sarcoma. | we have isolated a replication-defective rapidly transforming sarcoma virus (designated 16l virus) from a fibro-sarcoma in a chicken infected with td107a, a transformation-defective deletion mutant of subgroup a schmidt-ruppin rous sarcoma virus. 16l virus transforms fibroblasts and causes sarcomas in infected chickens within 2 wk. its genomic rna is 6.0 kilobases and contains sequences homologous to the transforming gene (fps) of fujinami sarcoma virus (fsv). rnase t1 oligonucleotide analysis s ... | 1982 | 6289331 |
| role of 3'-end of viral genome in tumor heteroinduction by the avian sarcoma virus. | transformation defective virus was derived by restriction endonuclease cleavage from a clone of the avian sarcoma virus schmidt-ruppin strain, strongly oncogenic for rats. the transfection experiments of chicken cells by digested proviral dna gave rise to transformation defective virus. the td virus was possible to recover in vivo in chickens. the tumors obtained after a long latent period contained the sarcoma virus which was able to transform chicken cells in vitro and to induce tumors in chic ... | 1982 | 6290399 |
| two structurally and functionally different forms of the transforming protein of prc ii avian sarcoma virus. | the primary translation product of the prc ii avian sarcoma virus genome is a protein of 105,000 daltons (p105), and we have previously shown that approximately 50% of the p105 molecules are converted to molecules of 110,000 daltons (p110) by posttranslational modification. fractionation of prc ii-infected cells showed that p105 was contained primarily in a nonionic detergent-soluble compartment, whereas p110 partitioned almost exclusively with a nonionic detergent-insoluble or crude cytoskeleta ... | 1982 | 6290871 |
| cell surface alterations of avian sarcoma virus b77- and 3,4-benzo(a)pyrene-transformed rat fibroblasts. i. cell surface proteins characterized by two-dimensional electrophoresis. | plasma membrane proteins of avian sarcoma virus b77-, 3,4-benzo(a)pyrene- and spontaneously transformed rat fibroblasts were metabolically- and cell surface radiolabeled and analyzed by electrophoresis under denaturing conditions (sds-page) or by two-dimensional electrophoresis. most extensive series of protein alterations on transformed cells was detected by two-dimensional electrophoresis of cell surface proteins radiolabeled by lactoperoxidase catalyzed radioiodination: a fibronectin-like 220 ... | 1982 | 6290912 |
| cell surface alterations of avian sarcoma virus b77-and 3,4-benzo(a)pyrene-transformed rat fibroblasts. ii. cell surface glycoproteins characterized by two-dimensional electrophoresis. | cell surface proteins of avian sarcoma virus b77-, 3,4-benzo(a)pyrene- and spontaneously transformed rat fibroblasts were tritium-radiolabeled by mild periodate oxidation followed by tritiated sodium borohydride reduction and by galactoseoxidase/nab3h4 technique. radiolabeled cell surface sialoglycoproteins were analyzed by electrophoresis under denaturing conditions (sds-page), or by two-dimensional electrophoresis (isoelectric focusing, sds-page). following major glycoproteins were quantitativ ... | 1982 | 6290913 |
| [schmidt ruppin-d-asv-induced primary rat brain tumor model for therapeutic screening]. | it is important to evaluate the therapeutic and side effects of new therapy for malignant brain tumors in an adequate animal model prior to its initial clinical investigation. for decades, neurooncologists have argued for the use of primary, autochthonous tumors rather than transplanted tumors such as c 6 glioma cells and 9 l gliosarcoma cells. but unfortunately, no spontaneous animal astrocytomas are currently available as usable models. so we tried to establish the model of primary, autochthon ... | 1982 | 6291561 |
| induction of murine tumors in adult mice by a combination of either avian sarcoma virus or human adenovirus and syngeneic mouse embryo cells. | primary murine rous sarcoma was produced in adult mice of seven strains, c57bl/6, dba/2, balb/c, c3h/he, cbaj, akr, and ddd, by s.c. inoculation of a mixture of 5 x 10(6) chicken tumor cells containing schmidt-ruppin rous sarcoma virus and 9- to 12-day-old mouse embryo cells (mec) (2 x 10(6) ) of the syngeneic strain. the sarcoma developed at the site of injection in almost all mice tested, but there were some differences in the latent period and the survival time among mouse strains. when the n ... | 1983 | 6291756 |
| determination of infectivity of transforming avian sarcoma virus and parotitis virus in fibrin-embedded monolayer cultures. | a sensitive and reproducible technique for titration of transforming avian sarcoma virus, rous sarcoma virus (rsv), in chick embryo cell monolayers embedded between two layers of a solid fibrin coagulum was developed. the foci of rsv-transformed fibrinolysis-exhibiting cells locally attacked the surrounding fibrin and were identifiable as plaque-like cell-free areas of retraction easily scored against the background of cells stained with neutral red. in comparison to the conventional assay in ag ... | 1982 | 6292249 |
| monoclonal antibody specific for avian sarcoma virus structural protein p27. | a hybridoma cell line which secretes antibody to the rous sarcoma virus (rsv) structural protein p27 has been established. the hybrid resulted from the fusion of ns-1 myeloma cells with spleen cells from a balb/c mouse which was immunized with rsv-transformed mouse cells. antibodies produced by the hybrid clone immunoprecipitated p27 and gag precursor proteins (pr180gag,pol, pr76gag and pr66gag) from [35s]methionine-labelled chicken embryo fibroblasts transformed by the schmidt-ruppin strain of ... | 1982 | 6292357 |
| characterization of c-lil, a chicken cellular sequence associated with a stock of b77 avian sarcoma virus. | using biochemical methods, we have shown that a new specific sequence, v-lil, is associated with a given stock of b77 avian sarcoma virus (clone 9). we prepared a dna complementary to v-lil sequences, using substractive hybridizations, and investigated the properties of this sequence. v-lil has a genetic complexity of ca. 2,000 nucleotides and is not present in various stocks of avian sarcoma virus, avian leukosis virus, or defective leukemia virus. v-lil is not associated with b77 avian sarcoma ... | 1982 | 6292471 |
| dna sequence of the viral and cellular src gene of chickens. 1. complete nucleotide sequence of an ecori fragment of recovered avian sarcoma virus which codes for gp37 and pp60src. | recovered avian sarcoma virus is a class of virus obtained from chicken tumors induced by mutants of rous sarcoma virus which have a deletion in the src gene. we have determined the entire nucleotide sequence of a 3.1-kilobase ecori dna fragment of molecularly cloned recovered avian sarcoma virus dna. this dna fragment contains part of the env gene and the entire src gene. amino acid sequences of both gene products were deduced from the dna sequences; the predicted amino acid sequences were veri ... | 1982 | 6292477 |
| dna sequence of the viral and cellular src gene of chickens. ii. comparison of the src genes of two strains of avian sarcoma virus and of the cellular homolog. | the nucleotide sequence of the src gene and flanking regions of the schmidt-ruppin strain of rous sarcoma virus (sr-a) was determined. the src region of sr-a was very homologous to that of recovered avian sarcoma virus (rasv1441), with only 17 differences among 1,578 nucleotides. the size of the predicted protein was 526 amino acids in both viruses, of which 6 amino acids were different. the differences in nucleotides and amino acids between the two viruses localized within the 5' two-thirds of ... | 1982 | 6292480 |
| avian myeloblastosis provirus cloned in a lambda bacteriophage is leukemogenic. | the avian myeloblastosis virus provirus inserted in a lambda bacteriophage, recombinant clone 11a1-1 (souza et al., proc. natl. acad. sci. u.s.a. 77:3004-3008, 1980), was transfected into chicken embryo fibroblasts which had been preinfected with either rous-associated virus type 61 or the transformation-defective avian sarcoma virus tdb77. within 4 to 5 h after transfection, the cells were injected into 16-day-old chicken embryos or 1-day-old chicks. acute myeloblastic leukemia developed after ... | 1982 | 6292502 |
| spatial distribution of proliferating cells in avian sarcoma virus-induced gliomas. | we studied the regional distribution of proliferating tumor cells in five avian sarcoma virus-induced gliomas. the labeling index and spatial distribution of [3h]thymidine (dthd)-labeled tumor cells were determined in serial sections of each tumor with a computer-assisted digitizing system. the density of [3h]dthd-labeled cells showed marked regional variation in each tumor, and the ratio of the density of [3h]dthd-labeled cells in tumor periphery to tumor center varied from 0.86 to 1.38. the la ... | 1983 | 6293696 |
| polyacrylamide gel mapping of chicken trna: comparison of polysome-bound and whole-cell trna from normal and avian sarcoma virus-infected chicken embryo fibroblasts. | analysis of the trna population from chicken cells was performed by means of polyacrylamide gel mapping. about 60 species were detected; most of these were positively identified by their acceptor specificity. the comparison of polysome-bound and overall cellular trna gel patterns from normal and rous sarcoma virus-infected chicken embryo fibroblasts led us to the following observations: some trna species were present in the same relative proportions in all the preparations, and within isoaccepti ... | 1982 | 6294501 |
| differential reactivity of serum antibody from tumor-bearing 15i5 x 7(2) chickens for cross-reactive species of endogenous retroviral envelope glycoprotein. | experiments were undertaken to determine if the sera of avian sarcoma virus-infected 15i5 x 7(2) chickens exhibit antibody reactivity for species of endogenous retroviral envelope glycoprotein expressed in 15i5 x 7(2) fibroblasts. two viruses were used for infection of the 15i5 x 7(2) chickens, pr-a and cl. 85; the envelope glycoprotein of pr-a, but not of cl. 85, is antigenically cross-reactive with 15i5 x 7(2) endogenous retroviral envelope glycoprotein. both the pr-a and cl. 85-infected 15i5 ... | 1983 | 6297160 |
| mapping of multiple phosphorylation sites within the structural and catalytic domains of the fujinami avian sarcoma virus transforming protein. | the phosphorylation sites of the p140gag-fps gene product of fujinami avian sarcoma virus have been identified and localized to different regions of this transforming protein. fsv p140gag-fps isolated from transformed cells is phosphorylated on at least three distinct tyrosine residues and one serine residue, in addition to minor phosphorylation sites shared with pr76gag. partial proteolysis with virion protease p15 or with staphylococcus aureus v8 protease has been used to generate defined pept ... | 1983 | 6298463 |
| two cellular proteins that are precipitated by an antitumor-rsv rat serum. | here we report studies on non-viral proteins specific for transformation precipitated by immune sera. these sera were from rats injected by pr-rsv transformed rat xc cells and from rabbits immunized by subcutaneous injections of cytoplasmic membranes from rat cells transformed by fujinami avian sarcoma virus. immune complexes were analyzed in one- or two-dimensional gel electrophoresis and by autoradiography. only by using antisera obtained from rats bearing xc-cells induced tumors, two proteins ... | 1982 | 6298644 |
| evidence for extensive methylation of ribosomal rna genes in a rat xc cell line. | xc cell line was established from a rat fibrosarcoma induced by avian sarcoma virus. analysis of ribosomal rna genes in the dna of this cell line indicated that there was a 3- to 4-fold increase in the number of the rdna repeating units. [methyl-14c]methionine labeling experiments as well as southern blot analysis of the restriction endonuclease fragments showed extensive methylation of the cytosine residues in the rdna. further analysis by hpaii, hhai and mspi suggested that the entire rdna rep ... | 1983 | 6299359 |
| involvement of macrophage-like cells in growth of tumors induced by avian sarcoma virus. | | 1983 | 6299524 |
| effect of rous sarcoma virus transformation of rat-1 fibroblasts upon their growth factor and anchorage requirements in serum-free medium. | the proliferative response of nontransformed rat embryo (rat-1) cells and avian sarcoma virus-transformed b31 cells to high-density lipoprotein (hdl), transferrin, insulin, epidermal growth factor (egf), and fibroblast growth factor has been compared. hdl, added in combination with transferrin, supported the active proliferation of low-density cultures of both rat-1 and b31 cells. no major difference in the sensitivity of rat-1 or b31 cells to hdl and transferrin was observed when cells were mai ... | 1983 | 6299541 |
| oncogene and its production of an avian sarcoma virus y73. | the y73 strain of avian sarcoma virus isolated from a transplantable chicken tumor was defective in its replicating capacity. the virus caused sarcoma but not acute leukosis in chickens even when inoculated intravenously. it induced transformed cell-foci in cultured fibroblasts and the viral genome responsible for in vitro transformation was 26s rna. the rna was composed of sequences in common with helper virus rna and y73-specific sequence. the specific sequence "yes" did not hybridize with com ... | 1982 | 6300025 |
| isolation and characterization of host range mutants of avian sarcoma virus. | two host range mutants of avian sarcoma virus (asv) were isolated from a clone of the bratislava 77 strain, subgroup c (b77-c). an hr- mutant was obtained by adaptation to duck cells and showed almost the same efficiencies of transformation (e.o.t.) and growth in cultures of chick embryo fibroblasts (cef) and duck embryo fibroblasts (def). an hr+ mutant showed lower e.o.t. and slower growth on def than on cef. characterization of these mutants and wild-type b77-c showed that (i) unlike the host ... | 1983 | 6300310 |
| [induction of cysts in adult rats by means of sodium nitrite after infection with avian sarcoma virus]. | trials were conducted to study the possible effect of sodium nitrite administered in drinking water as exerted upon carcinogenesis induced by the sarcoma virus in the organisms of adult rats during a five-month period of observation. no clinical changes were observed in these rats during the test period. on the 125th day of age the rats were subjected to post-mortem examination. cysts were found in seven of twenty rats (36.8%), as compared with the zero induction in the control groups. the cysts ... | 1983 | 6301135 |
| transforming genes of avian (v-fps) and mammalian (v-fes) retroviruses correspond to a common cellular locus. | the gardner (ga) and snyder-theilen (st) isolates of feline sarcoma virus (fesv) represent genetic recombinants between feline leukemia virus (felv) and transformation-specific sequences (v-fes gene) of cat cellular origin. a related transforming gene (v-fps), common to the fujinami, prc ii, and ur 1 strains of avian sarcoma virus has also been described. translational products of each of these recombinant virus isolates are expressed in the form of polyproteins exhibiting protein kinase activit ... | 1983 | 6301150 |
| regional blood flow in avian sarcoma virus (asv)-induced brain tumors. | regional blood flow (f) was measured in avian sarcoma virus (asv)-induced brain tumors in rats. blood flow was variable in individual as well as different tumors; tumor f did not correlate with histologic classification, tumor size, central versus peripheral tumor regions, intraparenchymal location, cell density, or specific cytologic characteristics. low values of f did correlate with tumor necrosis and hydrocephalus; high values of f correlated with tumorous invasion or association with choroi ... | 1983 | 6302562 |
| regional blood-to-tissue transport in avian sarcoma virus (asv)-induced brain tumors. | regional blood-to-tissue transport of 14c-alpha-aminoisobutyric acid (aib) was measured in avian sarcoma virus (asv)-induced rat brain tumors and expressed as a unidirectional transfer rate constant (k). the magnitude of k was variable and did not correlate with histologic classification or specific features of the tumors, with the possible exception of sarcomas. averaged mean k was highest for anaplastic astrocytomas and lowest for gemistocytic astrocytomas (ga); however, the range of measureme ... | 1983 | 6302563 |
| prevention of glioma induction in rats by simultaneous intracerebral inoculation of avian sarcoma virus plus bacillus calmette-guerin cell-wall preparation. | bacillus calmette-guerin cell-wall preparation was injected along with avian sarcoma virus in the brains of newborn fischer 344 rats, and subsequent glioma induction was compared with rats injected with avian sarcoma virus alone. the percentage of glioma induction and survival were found to be directly related to avian sarcoma virus concentration (10(0), 10(-1), 10(-2), and 10(-3)). a significant reduction in glioma induction occurred when bcg cell-wall preparation was injected with 10(-2) asv c ... | 1983 | 6302929 |
| the role of calmodulin in the proliferation of transformed and phenotypically normal tsasv-infected rat cells. | nrk cells infected with a temperature-sensitive, transformation-defective mutant of avian sarcoma virus (asv), tsla23, behaved as if nontransformed at a nonpermissive 40 degrees c and were rendered quiescent by serum deprivation. these serum-deprived cells were stimulated to start entering s phase about 7 hours after serum addition at 40 degrees c or about 9 hours after shifting the cultures to 36 degrees c, a temperature allowing the production of active viral pp60src and expression of the tran ... | 1983 | 6304122 |
| analysis of the pathogenicity of transformation defective partial deletion mutants of avian sarcoma virus: characterization of recovered viruses which encode novel src specific proteins. | several transformation defective (td) mutants of the prague strain of rous sarcoma virus, which had been previously shown to have deletions of varying sizes and positions within the src gene, were tested for their ability to induce disease in chickens. several of the mutants induced sarcomas after long latency, in particular two mutants which had deletions spanning the presumed active site (i.e., the phosphotyrosine residue) of the rsv transforming protein, pp60src. viruses recovered from these ... | 1983 | 6306917 |
| reduced binding of epidermal growth factor by avian sarcoma virus-transformed rat cells. | rat cells transformed by rous sarcoma virus and fujinami sarcoma virus bound 5-10% of the amount of epidermal growth factor (egf) bound by normal cells. scatchard plot analysis indicated that the reduction in binding by transformed cells was due to a decreased number of receptors rather than to altered binding affinity. in experiments with temperature sensitive mutants of rous sarcoma virus and fujinami sarcoma virus significant loss of egf binding occurred within one hour of shift from non-perm ... | 1983 | 6307296 |
| [development of oncogene study]. | the presence of oncogene was proved in 1969 with avian sarcoma virus b77. since then, the first oncogene was identified as src gene and many other oncogenes have been found and characterized in various sarcoma and acute leukosis viruses. these oncogenes have cellular counterparts called "c-onc"s. they appeared to be the origins of viral oncogenes and some of them were actually proved to be oncogenic after coupling with viral ltr or insertion into retroviral genome. the importance of activation o ... | 1983 | 6309088 |
| [identification and the origin of oncogenes, with special reference to sarcoma virus y73]. | a new sarcomagenic transforming gene, yes, was identified in an avian sarcoma virus y73. the gene product is a gag-fused polyprotein p90yes and have protein kinase activity phosphorylating tyrosine residues in proteins. vertebrates from fish to human were shown to contain dna sequence (c-yes) homologous with viral yes. total nucleotide sequence of y73 genome was determined and the predicted amino acid sequence of p90yes was found to be highly homologous with p60src, a gene product of src in rous ... | 1983 | 6309089 |
| alteration of phenotype of 'regressor' avian sarcoma cells following treatment with phorbol ester. | tumor cells which are cultured from the regressor phase of avian sarcoma virus (asv)-induced tumor growth are deficient with respect to ability to produce progeny transforming virus. in addition, such cells are relatively unreactive with anti-viral antibody and are unable to elaborate, into the medium, antigens which are stimulatory to the sensitized lymphocytes of virus-injected hosts. these deficits can be overcome by treatment of the cells with the tumor promoter, phorbol myristate acetate (p ... | 1983 | 6309365 |
| differential susceptibility of avian sarcoma cells derived from different periods of tumor growth to natural killer cell activity. | tumors which are induced in chickens by avian sarcoma virus usually grow actively for 2 to 3 weeks and then regress. we have cultured tumor cells from each of the active and regression periods of neoplastic growth and compared them in terms of sensitivity to natural killer (nk) activity and to specific cell-mediated cytotoxicity. the results indicate that those cells which derive from regressing sarcomas are sensitive to nk activity but resistant to specific cell-mediated cytolysis. in contrast, ... | 1983 | 6309377 |
| studies on the structure and organization of avian sarcoma proviruses in the rat xc cell line. | the structure and arrangement of the multiple provirus copies of avian sarcoma virus in a rat xc cell line were studied by restriction endonucleases. the following observations were made: (i) the majority of the proviruses integrated randomly with respect to cell dna; (ii) no gross deletions or rearrangements in the proviruses were observed; (iii) two types of proviruses (type i and type ii) could be distinguished on the basis of restriction endonuclease cleavage sites; (iv) the virus rescued fr ... | 1983 | 6310031 |
| occurrence of the tumor-specific, calcium-binding protein, oncomodulin, in virally transformed normal rat kidney cells. | oncomodulin, an apparently tumor-specific calcium-binding protein, has been detected in many chemically induced rat hepatomas. it is now possible to detect, by radioimmunoassay and immunofluorescence, the presence of oncomodulin in normal rat kidney cells virally transformed by avian sarcoma virus. by contrast, it was not detected in uninfected, nonneoplastic normal rat kidney cells. the protein was isolated and purified by a novel high-performance liquid chromatography procedure and shown to be ... | 1983 | 6311406 |
| stabilities of avian sarcoma virus rnas: comparison of subgenomic and genomic species with cellular mrnas. | the stabilities of b77 avian sarcoma virus intracellular rnas were compared to the stability of the total cellular poly(a)-containing rna by labelling infected chicken embryo fibroblasts with [3h]uridine for 15 h, adding actinomycin d (1 microgram per ml) to block further transcription of viral rna, and selecting virus-specific rna from the total cellular poly(a)-containing rna at 3 hourly intervals. the three virus-specific rna species (9.3, 3.3 and 5.4 kilobases) decayed with half-lives of 7.5 ... | 1983 | 6311951 |
| antigenic and structural studies on the transforming proteins of rous sarcoma virus and yamaguchi 73 avian sarcoma virus. | a widely cross reactive antiserum raised against denatured pp60v-src, the transforming protein encoded by rous sarcoma virus, was used to test antigenic relationships with the transforming gene products encoded by other avian sarcoma viruses. the results showed that p90gag-yes, the transforming protein of a representative of class iii avian sarcoma viruses, is antigenically related to pp60v-src. tryptic phosphopeptide analysis of p90gag-yes revealed two phosphotyrosine-containing peptides and on ... | 1983 | 6314646 |
| isolation and partial purification of a new class of transforming growth factors from an avian sarcoma virus-transformed rat cell line. | transformation of rat cells by avian sarcoma viruses induced the release of growth factors into serum-free conditioned medium. an avian sarcoma virus-transformed rat cell line, 77n1, produced and released a polypeptide growth factor, classified as a transforming growth factor (tgf), which transiently promotes anchorage-dependent balb3t3 a31 cells to form progressively growing colonies in soft agar. the tgf was isolated and partially purified from an extract of 77n1 cells by ion-exchange chromato ... | 1983 | 6315215 |
| an upstream regulatory domain of avian tumor virus long terminal repeat is required for the expression of a procaryotic neomycin gene in eucaryotic cells. | the regulatory elements present in the long terminal repeat (ltr) of avian sarcoma virus dna were analyzed by recombinant dna techniques coupled with dna-mediated gene transfer in avian as well as mammalian cells. for this purpose, the neomycin resistance gene from transposon tn5 was inserted downstream from the avian sarcoma virus ltr, and the recombinant plasmid dna was introduced into cells by the calcium phosphate technique. cells resistant to the drug g-418 were selected. analysis of the rn ... | 1983 | 6318077 |
| differences in the organization and methylation patterns of integrated avian sarcoma proviral dna sequences in nonpermissive and permissive mammalian cells. | four types of avian sarcoma virus (asv)-transformed mammalian cells were analyzed for the presence of asv-specific sequences in their genome dna. a great variability in the number of proviral copies and their structure within the dna of these lines was observed. in all cells tested gag and src sequences were present in a flexible arrangement. the greatest variation was detected within proviral sequences corresponding to pol and env regions. the number of integrated asv proviral copies do not cor ... | 1983 | 6318138 |
| avian sarcoma virus gag and env gene structural protein precursors contain a common amino-terminal sequence. | the initiation site for translation of the avian sarcoma virus glycoprotein precursor, pr63env, has been determined by analyzing the amino-terminal peptides of pr63env and the polyprotein precursor pr76gag encoded by the viral gag gene. the acceptor splice junction used to form the env gene mrna has also been identified. hybrid-selected virus-specific mrnas were translated in vitro in the presence of either l-[35s]methionine to label at every methionine residue or l-[35s]methionine-trnameti to l ... | 1984 | 6320182 |
| rnaase-sensitive dna-dependent dna polymerase from rat cells transformed by avian sarcoma virus. | an rnaase-sensitive dna polymerase from rat cells transformed by avian sarcoma virus has been characterized. the enzyme requires rna for its activity, as shown by its sensitivity to rnaase with endogenous as well as exogenous dna templates. this sensitivity is maintained after its purification by sucrose gradients and ion exchange columns. a molecular weight of about 100 000 has been estimated. this dna polymerase requires high salt concentration for its activity, is resistant to high concentrat ... | 1984 | 6320897 |
| nucleotide sequence of v-fps in the prcii strain of avian sarcoma virus. | prcii is an avian retrovirus whose oncogene (v-fps) induces fibrosarcomas in birds. the viral gene v-fps arose by transduction of an undetermined portion of a cellular gene known as c-fps. prcii is weakly oncogenic when compared with fujinami sarcoma virus, another transforming virus containing v-fps. as a first step in the elucidation of the molecular basis for the decreased virulence of prcii, we have determined the entire nucleotide sequence of v-fps in the prcii genome. the v-fps domain in p ... | 1984 | 6321783 |
| two strains of avian sarcoma virus newly isolated from chick fibrosarcomas induced by lymphatic leukemia virus subgroup a in two lines of chickens. | two strains of avian sarcoma virus, designated s1 and s2, have been newly isolated from avian lymphatic leukemia virus (llv) subgroup a [llv(a)]-induced fibrosarcomas in 2 chickens from 2 white leghorn flocks of lines 151 and bk. each stock of s1 and s2 contained 2-3 x 10(3) focus-forming units of virus/ml and 10(6) tissue culture infective dose of llv(a)/ml. the focus-forming titer of s1 and s2 estimated in chick embryo fibroblast cultures was almost consistent with that estimated by tumor (fib ... | 1984 | 6321843 |
| monoclonal antibodies specific for the avian sarcoma virus transforming protein pp60src. | monoclonal antibodies to avian sarcoma/leukosis virus-coded transforming, structural, and polymerase proteins have been developed. in this first communication, a monoclonal antibody to pp60src will be characterized. the antibody can bind to pp60src in radioimmunoassays, precipitates this antigen in protein kinase tests, and demonstrates in immunofluorescence investigations that pp60src has different intracellular localizations depending on whether rsv-transformed avian or mammalian cells are stu ... | 1984 | 6322430 |
| [analysis of the gene homology of the chicken sarcoma virus d6 and the rous sarcoma virus prague c strain]. | the results of a comparative analysis of genes of rous sarcoma virus (prague c strain) and those of avian sarcoma virus d6 isolated from 9,10-dimethyl-1, 2-benzoanthracene-induced avian tumor are presented. the genes of both viruses were shown to be highly homologous. | 1984 | 6322446 |
| analysis of the catalytic domain of phosphotransferase activity of two avian sarcoma virus-transforming proteins. | proteolytic digestion of the transforming protein of rous sarcoma virus (pp60src) with trypsin, chymotrypsin, or thermolysin generated a 29,000-dalton fragment representing the carboxyl half of this molecule. this proteolytic fragment was able to phosphorylate pp60src-specific immunoglobulin as well as exogenous substrates such as angiotensin, casein, and tubulin. when quantitated on a molar basis, the protease-resistant fragment of pp60src had a greater specific activity than the intact enzyme. ... | 1984 | 6323478 |
| monoclonal antibodies to the transforming protein of fujinami avian sarcoma virus discriminate between different fps-encoded proteins. | two monoclonal antibodies have been obtained that recognize antigenic determinants within the c-terminal fps-encoded region of p140gag-fps, the transforming protein of fujinami avian sarcoma virus (fsv). the hybridomas which secrete these antibodies (termed 88ag and p26c) were isolated after the fusion of ns-1 mouse myeloma cells with b lymphocytes from fischer rats that had been immunized with fsv-transformed rat-1 cells. fsv p140gag-fps immunoprecipitated by either antibody is active as a tyro ... | 1984 | 6323756 |
| [characterization of a transforming growth factor produced in rat cells transformed by an avian sarcoma virus]. | transformation of rat cells by avian sarcoma viruses (asvs) induced the release of transforming growth factors (tgfs), which transiently promote anchorage-dependent untransformed balb3t3 clone a31 cells to form progressively growing colonies in soft agar, into serum-free conditioned medium. a new class of tgf, which is a heat and acid-labile protein with a molecular mass of 12,000 daltons, was isolated and purified from an asv-transformed rat cell line, 77n1, derived from nrk cells. the tgf from ... | 1984 | 6324696 |
| the purification of an acid- and heat-labile transforming growth factor from an avian sarcoma virus-transformed rat cell line. | a new class of transforming growth factor (tgf), with chemical characteristics differing from previously reported tgfs, was isolated and purified from an avian sarcoma virus-transformed rat cell line, 77n1 . purification steps were simple and consisted of ion-exchange chromatography on diethylaminoethyl (deae)-sephacel, ammonium sulfate precipitation, chromatofocusing, and deae-sephadex a-25 chromatography. the purified tgf is a heat- and acid-labile protein with a molecular mass of 12,000 dalto ... | 1984 | 6327732 |
| molecular cloning and characterization of avian sarcoma virus ur2 and comparison of its transforming sequence with those of other avian sarcoma viruses. | avian sarcoma virus ur2 and its associated helper virus, ur2av , were molecularly cloned into lambda gtwes x lambda b by using unintegrated viral dnas. one ur2 and several ur2av clones were obtained. the ur2 dna was subsequently cloned into pbr322. both ur2 and ur2av dnas were tested for their biological activity by transfection onto chicken embryo fibroblasts. when cotransfected with ur2av dna, ur2 dna was able to induce transformation of chicken embryo fibroblasts with a morphology similar to ... | 1984 | 6328022 |
| characterization of a rous sarcoma virus mutant defective in packaging its own genomic rna: biological properties of mutant tk15 and mutant-induced transformants. | a mutant derived from a temperature-sensitive mutant of rous sarcoma virus ( tsny68 ) which showed extremely low infectivity was characterized. infection of chicken embryo fibroblast cells with the mutant, tk15 , induced two types of transformants, mutant-producing 15c (+) and nonvirus -producing 15c (-) transformants. 15c (+) cells expressed all four viral genes normally and produced a normal level of virus particles. no complementation was observed between the mutant and avian leukosis viruses ... | 1984 | 6328034 |
| transforming potential of a human protooncogene (c-fps/fes) locus. | the protooncogene c-fps/fes is a single vertebrate locus homologous to both the fps transforming gene of fujinami avian sarcoma virus and the fes transforming gene of two feline sarcoma virus isolates. the human c-fps/fes locus has been previously cloned and characterized. we report that a recombinant gene in which 3' human c-fps/fes sequences replace over 80% of the feline sarcoma virus fes sequences transforms nih 3t3 mouse fibroblasts and encodes a protein kinase. cells transformed by this re ... | 1984 | 6328490 |
| the avian sarcoma virus prcii lacks 1020 nucleotides of the fps transforming gene. | fujinami sarcoma virus (fsv) and prcii avian sarcoma virus both encode gag-fps transforming proteins associated with tyrosine-specific protein kinase activity; however, prcii has a lower oncogenic potential than does fsv. in this study, the genomes of prcii and fsv have been compared. by hybridization of prcii [32p]rna to fsv dna on southern blots, a large internal deletion in the 5' half of the fps gene in prcii has been mapped. to determine the exact size and location of the deletion in prcii, ... | 1984 | 6328746 |
| acquisition of host cell genetic information by avian sarcoma virus rescued from rat cells transformed by b77 virus. | the properties of avian sarcoma virus b77 grown in chick cells were compared with those of virus obtained by fusion of rat cells transformed by b77 virus ( rb77 cells) with chick cells ( fb77 virus). differences in the b77 and fb77 viral genomes were demonstrated by the fingerprint technique. the rescued fb77 virus contained sequences homologous to the normal cell genome. these results suggest that the rescued fb77 virus is a recombinant between b77 virus and rat genomic elements. the rnas from ... | 1984 | 6329138 |
| active viral genes in transformed cells lie close to the nuclear cage. | nuclear dna is looped by attachment to a matrix or cage. using nine different lines transformed by polyoma or avian sarcoma virus, we have mapped viral sequences integrated within these loops. in all lines that contain high concentrations of viral transcripts and express the transformed phenotype, the integrated viral genes lie close to the points of attachment to the cage. integration of polyoma dna induces outlying cellular sequences to become closely associated with the cage. the strength of ... | 1982 | 6329681 |
| the mitogenic activity of pp60v-src, the oncogenic protein product of the src gene of avian sarcoma virus, is independent of external serum growth factors. | the oncogenic pp60v-src product of asv (avian sarcoma virus) is shown to be a potent endogenous mitogen, which, unlike mitogens such as pdgf (platelet derived growth factor), is able to stimulate host cell proliferation without the help of other growth factors. thus, nrk rat cells, infected with a temperature-sensitive asv mutant which produces an abnormally thermolabile pp60v-src, became proliferatively quiescent at a pp60v-src-inactivating 40 degrees c in medium containing either 0.2% calf ser ... | 1984 | 6435613 |
| association of chromosome 4 abnormalities with ethylnitrosourea-induced neuro-oncogenesis in the rat. | cytogenetic studies of rat neurogenic tumor lines induced by ethylnitrosourea (enu) have shown specific involvement of chromosome 4. the study reported here further characterizes the association of chromosome 4 abnormalities in rat tumor cell lines with regard to etiological agent, tissue of origin, and tumorigenic potential of cloned lines. lines from rat gliomas induced by avian sarcoma virus did not show abnormalities of chromosome 4. enu-induced rat tumors of nonneurogenic origin had numeric ... | 1984 | 6692377 |
| carotid artery injections in 40- to 99-g fischer rats: technical note and evaluation of blood flow by various injection techniques. | despite extensive clinical use of brain tumor chemotherapy via the internal carotid artery (ica), demonstration of efficacy and toxicity screening of ica chemotherapy in brain tumor models has been limited. a method for performing ica injections in 40- to 99-g fischer rats is described, with documentation of its effect upon cerebral blood flow. a 33 gauge cannula was secured into a pe-10 catheter and, after ligation of the external carotid (eca) and the pterygopalatine arteries, injections were ... | 1984 | 6728142 |
| regional thymidine transport and incorporation in experimental brain and subcutaneous tumors. | the regional distribution and local incorporation of [14c]thymidine into a nonextractable tissue fraction, probably dna, was measured in normal and neoplastic tissues. we studied brain tumors induced by avian sarcoma virus and ethylnitrosourea, and transplanted rg-2 intracerebral and subcutaneous gliomas. an incorporation quotient, q, was calculated for different tumor regions and brain from the methanol nonextractable radioactivity in the tissue and the plasma concentration-time integral of thy ... | 1984 | 6736959 |
| synthetic peptide fragment of src gene product inhibits the src protein kinase and crossreacts immunologically with avian onc kinases and cellular phosphoproteins. | all the known avian sarcoma viruses have associated protein kinase activities that phosphorylate tyrosine residues of their target proteins. a decapeptide fragment of pp60src of rous sarcoma virus (rsv), residues 415-424, and an analog of that sequence have been chemically synthesized by solid-phase methods. the two decapeptides were not phosphorylated by pp60src of rsv, p90 of y73 avian sarcoma virus, or p140 of fujinami sarcoma virus. however, both peptides were able to inhibit competitively t ... | 1981 | 6801651 |
| transport of d-glucose by membrane vesicles from normal and avian sarcoma virus-transformed chicken embryo fibroblasts. | transport of d-glucose was examined in membrane vesicles from normal and avian sarcoma virus (asv)-transformed chicken embryo fibroblasts. the initial rates of d-glucose transport were found to be 3- to 5-fold higher for vesicles from glucose-starved normal cells and asv-transformed cells when compared with transport rates for vesicles from normal cells and serum-starved normal cells. cytochalasin b, phloretin, and diethylstilbestrol inhibited the initial rate of transport in all types of vesicl ... | 1981 | 6946477 |
| lymphocyte subpopulations and responsiveness in rats bearing intracranial tumors induced by avian sarcoma virus. | the mitogenic responsiveness of peripheral blood lymphocytes obtained from fischer 344 rats inoculated with avian sarcoma virus was studied. in addition, quantitative alterations in lymphocyte subpopulations were determined in these animals. only peripheral blood lymphocytes from rats bearing astrocytomas had significantly diminished responses to concanavalin a when compared to control responses. the percentage of lymphocyte subpopulations detected in either the peripheral blood or spleen of tu ... | 1981 | 6974229 |
| nature and intracellular location of the product of the src gene of avian sarcoma virus. | | 1980 | 7000431 |
| permeability of different experimental brain tumor models to horseradish peroxidase. | the permeability of different brain tumor models to horseradish peroxidase (hrp) was examined by determining the fraction of tumor that contained hrp after intravenous administration. the intracerebral tumor models studied were avian sarcoma virus (asv)-induced tumors and tumors from transplanted rg-2, s69-c1-5, and 9l cell lines. the average fraction of rg-2 tumors permeable to hrp was .95; of s69-c1-5 tumors, .699; of asv-induced tumors. .63; and of 9l tumors, .52. except for the rg-2 tumors, ... | 1982 | 7062086 |