| purification and properties of a highly potent antitumor glutaminase-asparaginase from pseudomonas 7z. | crystalline glutaminase-asparaginase which is effective against solid as well as ascites tumors was prepared from soil isolate organism pseudomonas 7a. this enzyme has a ration of vmax for l-glutamine and l-asparagine of 2.0. the presence of glutamic acid in the growth medium is essential for optimal enzyme production and glucose inhibits the production of glutaminase-asparaginase. the purification procedure provides an overall yield of 40 to 45% from crude cell extract to homogeneous glutaminas ... | 1976 | 5441 |
| influence of ph, salinity, and organic matter on the adsorption of enteric viruses to estuarine sediment. | this study was designed to determine the degree of adsorption of enteric viruses to marine sediment and factors controlling this association. adsorption and elution characteristics of several enteroviruses and one rotavirus to estuarine sediments were studied under varying conditions of ph, salinity, and presence of soluble organics. greater than 99% of the added poliovirus type 1 (lsc), coxsackievirus type b3 (nancy), echovirus type 7 (wallace), and rotavirus (sa-11) adsorbed to sediment. echov ... | 1979 | 39508 |
| isolation of the structural proteins of western equine encephalitis virus by isoelectric focusing. | western equine encephalitis virus was disrupted with triton x-100 and subjected to isoelectric focusing in a sucrose or urea gradient. the two envelope proteins, e1 and e2 were not well separated in a sucrose gradient, while the e1 and e2 proteins were distinguished as two major peaks which focused in a urea gradient at about ph 7.5 and 10, respectively. isolated e1 protein refocused at ph 6.5 in a sucrose gradient isoelectric focusing column. when western equine encephalitis virus was treated w ... | 1979 | 41505 |
| antigens of hepatitis b virus: failure to detect hbeag on the surfaces of hbsag forms. | the particulate forms of hbsag were analysed for the presence of hbeag on their surfaces. by immunodiffusion analysis, anti-hbe did not form precipitin bands with the purified forms of hbsag and hyperimmune guinea pig antisera to these forms did not react with hbeag. lines of non-identity were observed between the hbeag determinants (e1 and e2) and the dane particles and filaments isolated from an hbeag-positive serum. finally, anti-hbe failed to precipitate the polymerase-positive subpopulation ... | 1978 | 75946 |
| biochemical and antigenic comparison of the envelope glycoproteins of venezuelan equine encephalomyelitis virus strains. | pulse-chase experiments after synchronous initiation of translation indicate that the larger venzuelan equine encephalomyelitis (vee) virus membrane glycoprotein e2, is derived by proteolytic cleavage of the precursor, pe2. the structural proteins of vee virus strains representing each of the antigenic subtypes and varieties have been compared by discontinuous sds-polyacrylamide gel electrophoresis. nucleocapsid proteins of all isolates were similar in size (mol. wt. 35 to 36 x 10(3). the mol. w ... | 1979 | 119035 |
| the interaction of histones with simian virus 40 supercoiled circular deoxyribonucleic acid in vitro. | the interaction of supercoiled, circular sv40 dna with calf thymus histone fractions has been studied. five- to ten-fold less f1 histone is required to complex a given amount of dna compared to the other histones. when the supercoiled dna is converted to either the relaxed circular form, or full length linear molecules, or gragmented linear or denatured stands, the efficiency of complex formation with f1 histone markedly decreases. we conclude that f1 histone has a special ability to interact wi ... | 1975 | 163237 |
| isolation of a b-tropic type-c virus from reticulum cell neoplasms induced in balb/c mice by sjl/j type-c virus. | d1-murine leukemia virus (mulv), an n-tropic type-c virus isolated from a spontaneous reticulum cell neoplasm, type b (rcn-b) of an sjl/j mouse was propagated in nih swiss mouse embryo cell cultures. when injected into balb/c mice 1 day after neonatal thymectomy, 30% of the inoculated mice developed rcn-b in 5 months, whereas none of the uninoculated controls did. from the spleen and lymph node extracts of all rcn-b-bearing mice tested, b-tropic type-c viruses (designated e1-mulv) were isolated ... | 1975 | 163327 |
| sulfated components of enveloped viruses. | the glycoproteins of several enveloped viruses, grown in a variety of cell types, are labeled with 35so4(-2), whereas the nonglycosylated proteins are not. this was shown for the hn and f glycoproteins of sv5 and sendai virus, the e1 and e2 glycoproteins of sindbis virus, and for the major glycoprotein, gp69, as well as for a minor glycoprotein, gp52, of rauscher leukemia virus. the minor glycoprotein of rauscher leukemia virus is more highly sulfated, with a ratio of 35so4- [3h]glucosamine abou ... | 1975 | 170420 |
| translation of the genes for the structural proteins of alphaviruses. | synthesis of the structural proteins of semliki forest virus by a cell-free system derived from mouse l-cells and programmed by intracellular 26s rna is described. this polycistronic rna is translated in vitro into several discrete polypeptides. the identity of these polypeptides as the structural proteins of the virus was established by polyacrylamide gel electrophoresis, immunoprecipitation and tryptic peptide mapping. studies using formyl--e135s]methionyl-trnaf as precursor, and using diphthe ... | 1975 | 173941 |
| dna gyrase: an enzyme that introduces superhelical turns into dna. | relaxed closed-circular dna is converted to negatively supercoiled dna by dna gyrase. this enzyme has been purified from escherichia coli cells. the reaction requires atp and mg++ and is stimulated by spermidine. the enzyme acts equally well on relaxed closed-circular colicin e1, phage lambda, and simian virus 40 dna. the final superhelix density of the dna can be considerably greater than that found in intracellularly supercoiled dna. | 1976 | 186775 |
| dibutyryl cyclic amp treatment of 3t3 and sv40 virus-transformed 3t3 cells in aggregates. effects on mobility and cell contact ultrastructure. | the random cell movement of balb/c 3t3 and sv40 virus-transformed balb/c 3t3 cells within homogeneous aggregates was studied by observing the degree of penetration of newly attached [3h]thymidine-labeled cells into the interior of the aggregates. the 3t3 cells penetrated into 3t3 aggregates an average of 0.89 cell diameter in 1.5 days, whereas the sv40-3t3 cells penetrated into sv40-3t3 aggregates an average of 3.20 cell diameters in the same time. treatment of the aggregates with theophylline, ... | 1977 | 188830 |
| adherence of human peripheral blood lymphycytes to measles-infected cells. enhancement by prostaglandin e1. | we studied the effect of prostaglandins in vitro on an immune reaction mediated by t cells; adherence of lymphocytes to measles-virus-infected human epithelial cells. normal human lymphocytes adhered to a mean +/- s.d. 20.1 +/- 5.2 per cent of these hep-2 cells. the percentage positive cells increased to 50.3 +/- 5.7 when lymphocytes were incubated with 10(-6) m prostaglandin e1 (p less than 0.01 vs. untreated lymphocytes); 10(-8) m and 10(-10) m were as effective. prostaglandin f2alpha had no e ... | 1977 | 194153 |
| glucocorticoids increase the responsiveness of cells in culture to prostaglandin e1. | the influence of steroid hormones on the response of human astrocytoma cells (1321n1) to prostaglandin e(1) (pge(1)) has been investigated. responsiveness to pge(1) was determined by measuring the conversion of [(3)h]atp to cyclic [(3)h]amp in cells prelabeled with [(3)h]adenine. after incubation of the cells with dexamethasone, a marked increase in both the maximal effect (2- to 3-fold) and the potency (5-fold) of pge(1) was observed. the effect was specific for the action of pge(1) in that no ... | 1977 | 200933 |
| regulation of adenosine 3':5'-monophosphate content of rous sarcoma virus-transformed human astrocytoma cells. effects of cholera toxin on the responsiveness to catecholamines and prostaglandins. | human astrocytoma cells (eh118mg) respond to catecholamines and prostaglandins with a marked increase in the rate of formation of cyclic amp. treatment of eh118mg cells with cholera toxin (10 to 100 ng/ml) for 45 to 60 min caused an increase in cellular cyclic amp content (5- to 10-fold over basal). cholera toxin also decreased the k0.5 for isoproterenol 10- to 50-fold and decreased the k0.5 for prostaglandin e1 (pge1)30- to 100-fold, while increasing the maximal response to pge1 by 1.5- to 3-fo ... | 1978 | 203593 |
| role of sediment in the persistence of enteroviruses in the estuarine environment. | the survival of four enteroviruses commonly found in sewage effluents was examined when the viruses were adsorped to marine sediments in estuarine water and compared with virus survival in estuarine water alone. echovirus 1, coxsackieviruses b3 and a9, and poliovirus 1 survived longer when associated with marine sediment. when the estuarine water was polluted with secondarily treated sewage effluent, virus survived for prolonged periods in sediments, but not in the overlaying estuarine water. | 1978 | 206204 |
| polyoma virus and cyclic amp-mediated control of dihydrofolate reductase mrna abundance in methotrexate-resistant mouse fibroblasts. | as a model cell culture system for studying polyoma-mediated control of host gene expression, we isolated methotrexate-resistant 3t6 cells in which one of the virus-induced enzymes, dihydrofolate reductase, is a major cellular protein. in highly methotrexate-resistant cell lines dihydrofolate reductase synthesis accounts for over 10% that of soluble portein, corresponding to an increase of approximately 100-fold over the level in parental cells. this increase in dihydrofolate reductase synthesis ... | 1979 | 216671 |
| effect of temperature-sensitive mutation on activity of the rna transcriptase of vesicular stomatitis virus new jersey. | the virion-associated rna transcriptase activity of vesicular stomatitis virus new jersey temperature-sensitive (ts) mutants was assayed in vitro at the permissive (31 degrees c) and restrictive (39 degrees c) temperatures. rna synthesis at 39 degrees c by the rna-negative ts a1 and the rna-positive ts c1 and ts d1 mutants was similar to that of wild-type virus. the rna-negative ts b1 synthesized only small amounts of rna in vitro at 39 degrees c. the three mutants of complementation group e wer ... | 1979 | 225538 |
| temperature-sensitive mutants of complementation group e of vesicular stomatitis virus new jersey serotype possess altered ns polypeptides. | in vesicular stomatitis virus new jersey serotype polyacrylamide gel electrophoresis was unable to distinguish the polypeptides of the temperature-sensitive (ts) mutants of complementation groups a, b, c, and f from those of the wild-type virus. however, the ns polypeptide of the representative mutant of group e, ts e1, had a significantly greater electrophoretic mobility than that of the wild-type virus ns polypeptide. the electrophoretic mobilities of the ns polypeptides of the three mutants o ... | 1979 | 225557 |
| proposed replicative role of the ns polypeptide of vesicular stomatitis virus: structural analysis of an electrophoretic variant. | the structural lesion in the temperature-sensitive mutant e1 of the new jersey serotype of vesicular stomatitis virus has been assigned to the ns protein. although the packaged wild-type and mutant ns proteins were similarly phosphorylated, the mutant ns protein migrated faster than the wild-type ns protein in polyacrylamide slab gels electrophoresed in the presence of sodium dodecyl sulfate. the resolution appears to be the result of conformational rather than size differences since the two pro ... | 1979 | 228061 |
| the use of haemophilus gallinarum dna-relaxing enzyme to investigate the relationship between the number of superhelical turns and the molecular weight in a negatively twisted dna. | covalently closed-circular, superhelical dnas, including viral dnas, bacterial plasmid dnas, and bacteriophage replicative-form dna, were treated with a small amount of haemophilus gallinarum dna-relaxing enzyme to generate incompletely relaxed dna molecules. each sample consisted of a set of closed-circular dna molecules differing by one turn in their number of superhelical turns. the dna samples were analyzed by agarose gel electrophoresis under conditions such that the electrophoretic mobilit ... | 1979 | 229100 |
| the 55k protein on the 5' termini of adenovirus type 2 dna is unrelated to virus-coded candidate transformation proteins (e1-53k, e1-40k-50k) and dna-binding proteins (e2-42k/47k/73k). | a polypeptide of 55,000 daltons (55k) is linked, probably covalently, to the k' termini of adenovirus type 2 dna. the 55k polypeptide is synthesized during early stages of infection (t. yamashita, m. arens, and m. green, j. virol. 30: 497-507, 1979) and thus may function in viral dna replication, gene regulation, or cell transformation. several virus-coded early polypeptides have been identified that could correspond to the terminal 55k, including the e1-40k-50k and e1-53k candidate transformati ... | 1979 | 229254 |
| the effects of ultraviolet and ionizing radiation on herpesviruses, sv40 and adenoviruses in relation to the small-plaque effect. | the small-plaque effect occurs with a wide range of herpesviruses following irradiation with ultraviolet light. the 37 per cent survival (d37) values, or dose required for one lethal hit (e-1), for herpes simplex, pseudorabies and pigeon herpesviruses in different cells indicate a broad spectrum of host-cell repair capacity. other dna-containing viruses such as sv40 and adenoviruses, which also replicate in the cell nucleus, show the small-plaque effect. ionizing irradiation of herpes simplex vi ... | 1979 | 231946 |
| antibody dependent cell-mediated cytotoxicity to herpes simplex virus in man: the influence of drugs on polymorphonuclear leucocyte and mononuclear effector cells. | we have shown that the function of the effector cells in antibody mediated cell dependent cytotoxicity (adcc) can be reduced by the use of a number of drugs and prostaglandins. both polymorphonuclear leucocyte and mononuclear effector cells were studied. aminophylline and isoproterenol markedly reduced this activity. all the prostaglandins tested--pga1, a2, e1 and e2 had a similar but more profound effect. at a dose of 100 mg/ml hydrocortisone had relatively little influence and neither asa nor ... | 1979 | 233219 |
| streptovirudins -- new antibiotics with antiviral activity. the antiviral spectrum and inhibition of newcastle disease virus in cell cultures. | streptovirudins are new antibiotics isolated as a mixture of several structurally related compounds from fermentations of streptomyces griseoflavus (krainsky) waksman et henrici var. thuringensis ja 10124. they possess antiviral activity against rna and dna viruses cultivated in chick embryo cells, namely sindbis, fowl plague, newcastle disease (ndv), pseudorabies, vaccinia and sheep abortion viruses. the naturally formed streptovirudin complex, in concentrations of 20-2.5 mug/ml inhibited the v ... | 1975 | 241229 |
| evidence for covalent attachment of fatty acids to sindbis virus glycoproteins. | selective binding of lipid to glycoprotein was detected when [3h]palmitate-labeled sindbis virus particles or viral-infected cells were disrupted by heating with sodium dodecyl sulfate, and glycoproteins were isolated by electrophoresis in sodium dodecyl sulfate/10% polyacrylamide gels. the smaller glycoprotein (e2) retained 2 to 3 times more labeled lipid than did the larger ei glycoprotein, and the cell-associated glycoprotein precursor (pe2) bound even less lipid. no lipid was associated with ... | 1979 | 287008 |
| envelope antigens of sindbis virus in cells infected with temperature-sensitive mutants. | indirect fluorescent-antibody studies of living and fixed chick cells infected with temperature-sensitive mutants of sindbis virus suggest that functional envelope glycoprotein e1 must be inserted through the plasma membrane before e2. pe2 and e2 do not affect the insertion of e1. the experiments also suggest that normal pe2, a glycosylated precursor to e2, reacts with anti-e2 serum; the abnormal pe2 made by a temperature-sensitive pe2 cleavage-defective mutant did not. abnormal e1 proteins made ... | 1977 | 319257 |
| protein expression in e. coli minicells by recombinant plasmids. | the polypeptides synthesized in e. coli minicells from recombinant plasmids containing dna fragments from cauliflower mosaic virus, drosophila melanogaster, and mouse mitochondria were examined. molecularly cloned fragments of cauliflower mosaic virus dna directed the synthesis of high levels of three polypeptides, which were synthesized entirely from within the cloned virus dna fragments independent of their insertion into the plasmid vehicles. several fragments of d. melanogaster dna were capa ... | 1977 | 403011 |
| ultrastructural study of cell cultures infected with swinepox and orf viruses. | monolayer cells of a porcine kidney cell line were infected with the pp-1 strain of swinepox virus, while secondary or third subcultured monolayer cells of african green monkey kidney were inoculated with the iwate bt-9 strain of orf virus. those infected cells were fixed when cpe became remarkable in the monolayers and examined by electron microscope. in the cytoplasm of cells infected with both viruses, various immature forms of viral particles in different developmental stages were observed. ... | 1977 | 412491 |
| membrane biogenesis. in vitro cleavage, core glycosylation, and integration into microsomal membranes of sindbis virus glycoproteins. | sindbis virus 26s rna has been translated in a cell-free protein-synthesizing system from rabbit reticulocytes. when the system was supplemented with edta-stripped dog pancreas microsomal membranes, the following results were obtained: (a) complete translation of 26s rna, resulting in the production, by endoproteolytic cleavage, of three polypeptides that are apparently identical to those forms of c, pe2, and e1 that are synthesized in vivo by infected host cells during a 3-min pulse with [35s]m ... | 1979 | 422651 |
| [morphological and clinical liver changes after taking oral contraceptives]. | in 155 women of the age group 16-45 years after intake of oral contraceptives in 68.4% (106 cases) histologically provable liver changes were found. sinusoidal ectasias of different size and drug-conditioned hepatitides most frequently occurred. an isolated intrahepatic cholestase only rarely existed. increases of transaminase are the most frequent reference to a lesion of the liver parenchyma after intake of oral contraceptives. the author adopts a definite attitude to the differential diagnosi ... | 1979 | 425584 |
| enhancement of hormonal stimulation in intact cells. potentiation of gtp-dependent activation of adenylate cyclase. | the ability of prostaglandin e1 (pge1) and cholera toxin to increase cyclic amp levels is potentiated 6-fold when normal rat kidney (nrk) cells are treated with picolinic acid or histidinol, or grown in isoleucine-deficient medium. the response to (-)-isoproterenol is increased 2-fold in nrk cells treated with picolinic acid but not in cells subjected to isoleucine deprivation. the increase in agonist responsiveness is time-dependent, reaches its maximum at 40 h, and is quickly reversed followin ... | 1979 | 447667 |
| separation of the integral membrane glycoproteins e1 and e2 of semliki forest virus by affinity chromatography on concanavalin a-sepharose. | the membrane glycoproteins e1 and e2 of semliki forest virus are of about equal size but can be separated from each other by affinity chromatography on a concanavalin a-sepharose column in the presence of sodium dodecyl sulfate. the e1 protein eluted like glycopeptides containing two peripheral sugar branches composed of n-acetylglucosamine, mannose, galactose and sialic acid. the e2 eluted like glycopeptides containing only n-acetylglucosamine and mannose. | 1979 | 465536 |
| requirements for the insertion of the sindbis envelope glycoproteins into the endoplasmic reticulum membrane. | previous work has shown that the sindbis structural proteins, core, the internal protein, and pe2 and e1, the integral membrane glycoproteins are synthesized as a polyprotein from a 26s mrna; core pe2 and e1 are derived by proteolytic cleavage of a nascent chain. newly synthesized core protein remains on the cytoplasmic side of the endoplasmic reticulum while newly synthesized pe2 and e1 are inserted into the lipid bilayer, presumably via their amino-termini. pe2 and e1 are glycosylated as nasce ... | 1979 | 479287 |
| the effect of membrane-active agents on sindbis virus morphogenesis. | in chicken cells infected by sindbis virus and exposed to a variety of membrane-active compounds, virus release was inhibited. in infected cells exposed to antiserum directed against the virion glycoproteins e1 or e2, retinol, cortisone, pb++ or insulin, the processing of two sindbis virus precursor polypeptides which lead to the formation of virion polypeptides was inhibited. the b-protein, which is the precursor to both envelope proteins, accumulated in cells treated by these compounds. this p ... | 1979 | 500330 |
| physicochemical properties and restriction maps of simian adenovirus type 38 dna. | the sedimentation constant of simian virus type 38 (sv-38) dna was estimated to be 31.6s. the intrinsic viscosity of dna was on average 86.5 dl/g and the length of the molecule determined by electron microscopy was 10.6 micrometer. the average mol. wt., as determined by sedimentation and viscometry, was 21.5 x 10(6), which agreed well with the value derived from the length of the molecule (21.4 x 10(6)) and with the value of 21.2 x 10(6) determined by the relative electrophoretic mobility of the ... | 1979 | 501339 |
| modulation of the adherence of human lymphocytes to measles-infected cells by prostaglandin e1: a differential effect on lymphocyte subpopulations. | prostaglandins of the e series (pge) may serve as important regulators of human immune responsiveness. the present study was designed to examine the possibility that pge may effect human lymphocyte function by the modulation of surface receptors. the presence of surface binding sites on human lymphocytes for measles virus antigens was studied using a rosette adherence assay. we observed that the addition of pge1 increased the proportion of measles-infected cells (hela-kll) with adherent lymphocy ... | 1979 | 523674 |
| sequence analysis of lactosamine type glycans of individual membrane proteins of semliki forest virus. | 3h-fucose and 14c-glucosamine labelled glycopeptides of the individual membrane proteins e1, e2 and e3 of semliki forest virus could be sequentially digested with alpha-neuraminidase, beta-galactosidase, n-acetyl-beta-glucosaminidase, alpha- and beta-mannosidase, n-acetyl-beta-hexosaminidase and finally with alpha-fucosidase. the degradations of the virus glycopeptides proceeded in the same way as stepwise digestions of reference glycopeptides of the lactosamine type obtained from igg and alpha ... | 1979 | 541666 |
| a possible role for polymorphonuclear leucocytes in the defence against recrudescent herpes simplex virus infection in man. | we have used a 51cr release assay to demonstrate that human polymorphonuclear leucocytes (pmnl) can damage herpes simplex infected target cells sensitized with antiviral antibody. effective sensitizing antibodies were found in both serum and saliva of all those persons tested who were subject to recurrent cold sores. pmnl were much less effective as killer cells than peripheral blood mononuclear cells, but as they are the predominant inflammatory cell with the hsv1 lesion they may be, quantitati ... | 1978 | 640713 |
| effect of low-nacl medium on the envelope glycoproteins of sindbis virus. | lowering the nacl concentration of the medium inhibits the release of sindbis virus from infected chicks cells at a stage after the nucleocapsids have bound to the membranes of the infected cells. the failure of trypsin treatment to release the inhibited virus and the ratio of the proteins in the inhibited cells make it seem likely that the inhibited virus is all intracellular. experiments using antisera specific for e1 and e2, the envelope glycoproteins of sindbis, suggest that the inhibitory e ... | 1978 | 642072 |
| altered e2 glycoprotein of sindbis virus and its use in complementation studies. | we have detected a sindbis virus variant that contains a smaller-molecular-weight form of the viral glycoprotein e2. the molecular weight of the pe2 precursor and the glycosylation pattern of the smaller e2 are normal, thus indicating that this e2 is formed by an aberrant proteolytic cleavage. the altered e2 was detected in an rna+ temperature-sensitive mutant that was defective in proteolytic cleavage, but the abnormal pe2-to-e2 reaction could be separated from the ts mutation and is not itself ... | 1978 | 650737 |
| chemical cross-linking of proteins of semliki forest virus: virus particles and plasma membranes from bhk-21 cells treated with colchicine or dibucaine. | chemical cross-linking of the proteins of semliki forest virus has been performed in virus particles and in baby hamster kidney-21 (bhk-21) cells infected with semliki forest virus. most of the studies were done with the reversible cross-linkers dimethyl 3,3'-thiobis(propionimidate) and dithiobis(succinimidyl propionate). the identity of the cross-linked species was determined by two-dimensional electrophoresis. the results with virus particles showed extensive cross-linking of the nucleocapsid ... | 1978 | 702646 |
| characterization of a sinbis virus variant with altered host range. | a variant of sindbis virus which is much more infectious for mouse cells than the standard virus has been examined for biochemical properties which might be responsible for this biological difference. the variant has a much enhanced ability to adsorb to mouse plasmacytoma (mopc 315) cells, but when these cells were pretreated with heparin, they were able to adsorb the standard virus almost as well as the variant. this suggested that there was a surface charge difference between variant and stand ... | 1978 | 708264 |
| the molecular size of glycans liberated by hydrazinolysis from semliki forest virus proteins. | the glycans of well characterized, [6-3h]galactose-labelled glycopeptides, gc-4 from bovine igg1 as well as gp-v-2 and gp-v-5 from alpha1-acid glycoprotein, were liberated by hydrazinolysis. molecular weights close to the expected values were observed by gel filtration. desialated glycans of semliki forest virus proteins were likewise liberated by hydrazinolysis and subjected to gel filtration. metabolically labelled [1-3h]galactose-oligosaccharides of the mixed viral proteins revealed an appare ... | 1979 | 760827 |
| lymphocyte adherence in multiple sclerosis: effect of aspirin. | peripheral blood lymphocytes from multiple sclerosis (ms) patients form substantially greater numbers of rosettes with measles virus-infected human epithelial cells than do lymphocytes from healthy controls or from patients with other diseases. we have previously shown that prostaglandin e(1)-treated normal lymphocytes exhibit increased lymphocyte adherence, and thus behave like ms lymphocytes in this in vitro system. in this study we describe the effect of prostaglandin synthesis inhibition on ... | 1979 | 762244 |
| comparison of the biophysical and biochemical properties of penicillium cyaneo-fulvum virus and penicillium chrysogenum virus. | the biophysical and biochemical properties of penicillium cyaneo-fulvum virus (pc-fv) and penicillium chrysogenum virus (pcv) have been compared. in sucrose density gradient sedimentation, purified virus preparations gave one major component, l, and three minor components e1, e2 and h with sedimentation coefficients of 145s, 80s, 102s and 172s respectively in each case. e1, e2 were shown to be empty particles. pc-fv l particles contained only double-stranded rna, which separated in polyacrylamid ... | 1977 | 833575 |
| interaction of sindbis virus glycoproteins during morphogenesis. | in cells infected with the sindbis temperature-sensitive mutants ts-23 and ts-10 (complementation group d), which contain a defect in the envelope glycoprotein e1, the precursor polypeptide pe2 is not cleaved to the envelope glycoprotein e2 at the nonpermissive temperature. this defect is phenotypically identical to the defect observed in the complementation group e mutant, ts-20. the lesion in ts-23 is reversible upon shift to permissive temperature, whereas that of ts-10 is not. antiserum agai ... | 1977 | 833949 |
| how a single sindbis virus mrna directs the synthesis of one soluble protein and two integral membrane glycoproteins. | previous work has shown that the 26s rna found in sindbis-infected chicken embryo fibroblasts encodes the three viral structural proteins, one internal protein, core, and two membrane glycoproteins, e1 and e2. this mrna has one initiation site; core, e1, and e2 are derived by proteolytic cleavage. here we show that during infection, the 26s rna is found mainly in membrane-bound polysomes which synthesize all three virion structural proteins. these polysomes are released from the membrane upon tr ... | 1977 | 837448 |
| maturation defect of a temperature-sensitive mutant of western equine encephalitis virus. | the defective step of a temperature-sensitive mutant of western equine encephalitis virus, which synthesize viral rna but not mature virus at the restrictive temperature, was studied. cells infected with the mutant virus at the restrictive temperature synthesized the same intracellular viral rna as that in wild type infection. cells infected with the mutant at the restrictive temperature formed three proteins (e1, e2 and c) which migrated to positions identical with those of purified virions and ... | 1977 | 857772 |
| infectious virus-antibody complexes of sindbis virus. | infectious virus-antibody complexes were formed when sindbis virus was reacted with antibodies raised against purified viral envelope glycoproteins e1 and e2 as well as against preparations of intact virus. results from rate zonal centrifugation in sucrose gradients of the complex formed with anti-e1 sera showed this complex to be about the same size as virions. a test of virus neutralization, based on direct plaque assay, by antibodies raised in rabbits and mice given virus in complete freund a ... | 1977 | 870428 |
| envelopments of sindbis virus: synthesis and organization of proteins in cells infected with wild type and maturation-defective mutants. | the synthesis and organization of sindbis virus structural proteins was investigated in bhk cells infected with wild-type virus (svhr) or temperature-sensitive (ts) mutants defective in maturation. cells infected with ts-23 or ts-20 (complementation groups d and e) were similar in the polypeptides synthesized at the nonpermissive temperature and differed from svhr-infected cells in that the envelope protein e2 was not cleaved from the pe2 precursor. data from experiments utilizing pulse-chase pr ... | 1977 | 875134 |
| statistical determination of endotoxin content in influenza virus vaccine by the limulus amoebocyte lysate test. | to determine laboratory-to-laboratory variability of the limulus amoebocyte lysate (lal) test for evaluating endotoxin content in influenza virus vaccine, a collaborative study was designed. participants were six influenza virus vaccine manufacturers and the bureau of biologics (bob). lysate lot 116, reference influenza virus vaccine for endotoxin assay e-1, and four test vaccines having different ratios of lal activity relative to reference e-1 were supplied by the bob. each laboratory used its ... | 1977 | 893659 |
| the purification and properties of two low-molecular-weight proteins required for the initiation of translation in ascites tumour cells. | a fractionated cell-free protein-synthesising system from krebs ii ascites tumour cells is described. it is dependent on the addition of exogenous mrna. in this system the translation of natural mrnas requires the presence of four initiation factors: the high-molecular-weight complex if-m3, ifemc and two low-molecular-weight proteins if-malpha and if-mbeta. none of these factors are required for the translation of the synthetic messenger poly(a,u,g). the purification of if-malpha and if-mbeta wa ... | 1977 | 908335 |
| studies on the role of plasminogen activator in ovulation. in vitro response of granulosa cells to gonadotropins, cyclic nucleotides, and prostaglandins. | a quantitative method is described for measuring the amount of plasminogen activator produced by rat ovarian granulosa cells following exposure to hormones in vivo or in vitro. the results confirm the previously reported observation (beers, w. h., strickland, s., and reich, e. (1975) cell 6, (387-394) that granulosa cells in vivo produce increasing amounts of plasminogen activator as the time of ovulation approaches and that the enzyme is produced only be cells obtained from follicles destined t ... | 1976 | 965386 |
| defects in rna+ temperature-sensitive mutants of sindbis virus and evidence for a complex of pe2-e1 viral glycoproteins. | | 1976 | 982835 |
| purification and composition of the proteins from sindbis virus grown in chick and bhk cells. | procedures are described for the purification of the sindbis virus structural proteins. the amino acid and carbohydrate compositions of the purified proteins are presented for virus grown in bhk-21/13 and chicken embryo cells. glycoprotein e1 from virus grown in bhk cells is deficient in a mannose-rich glycopeptide found on that glycoprotein when virus is grown in chicken embryo cells. the complex glactose-containing glycopeptides appear similar for virus grown in both hosts. however, when virus ... | 1976 | 994303 |
| serum glycoprotein-type sequence of monosaccharides in membrane glycoproteins of semliki forest virus. | semliki forest virus was grown in bhk-21 cells and labelled in vivo with radioactive monosaccharides. the virus was disrupted with sodium dodecyl sulphate and the polypeptides were hydrolyzed with pronase. a mixture of type a glycopeptides (for nomenclature, see johnson and clamp (1971) biochem. j. 123, 739-745) of the membrane glycoproteins e1 and e3 was isolated by gel filtration and subjected to sequential degradation with exo-glycosidases. the reduction in the apparent molecular weight and t ... | 1976 | 999925 |
| [central activity, antihypertensive action and antiulcerogenic effects of neurotropin]. | central activity, antihypertensive action and antiulcerogenic actions of neurotropin (nsp), an extract isolated from vaccinia virus-innoculated skin or tissues of rabbits were investigated herein. when actions of nsp were examined in isolated muscle preparations by the magnus-method, peristalsis and ach-induced contraction in the small intestine isolated from crayfish were not influenced, peristalsis and ach-induced contraction in the small intestine from mice were slightly accelerated, but adre ... | 1976 | 1035190 |
| sequential translation of nonstructural proteins in cells infected with a semliki forest virus mutant. | four nonstructural proteins with apparent molecular weights of 70,000 (ns-70), 86,000 (ns-86), 78,000 (ns-78), and 60,000 (ns-60) were translated in cells infected with semliki forest virus ts-1 mutant and maintained at the restrictive temperature. after synchronization of the initiation of protein synthesis these proteins were synthesized in the above order, suggesting that they are translated as a polyprotein starting from one initiation site. two short-lived intermediates with apparent molecu ... | 1976 | 1064863 |
| replication of semliki forest virus. | replication of semliki forest virus, a typical alphavirus, takes place in the cytoplasm of many eukaryotic cells. the virus genome, the 42 s rna, directs the synthesis of at least two rna-dependent rna polymerases. by the aid of these enzymes complementary 45 s rna is synthesized; it serves as a template for the synthesis of positive rna strands with sedimentation values of 45 s and 26 s. in bhk cells close to 200,000 molecules of each rna species are produced per cell. both 26 s and 42 s rnas a ... | 1975 | 1107685 |
| effect of impaired glycosylation on the biosynthesis of semliki forest virus glycoproteins. | the glycoproteins of semliki forest virus, grown in chicken embryo cells, were labeled with radioactive sugars. the data indicate a high mannose content of the nonstructural precursor glycoprotein nsp 63. this protein can also be readily labeled with 2-deoxy-d-glucose. the envelope glycoproteins e1 and e2 are relatively rich in galactose, glucosamine, and fucose. glycosylation can be impaired by 2-deoxy-d-glucose or d-glucosamine or by omission of sugars in the culture medium. under these condit ... | 1975 | 1159895 |
| tryptic peptide analysis on nonstructural and structural precursor proteins from semliki forest virus mutant-infected cells. | analysis of [35s]methionine-labeled tryptic peptides of the large proteins induced by temperature-sensitive mutants of semliki forest virus was carried out. the 130,000-molecular-weight protein induced by ts-2 and ts-3 mutants contained the peptides of capsid protein and of both major envelope proteins e1 and e2. the ts-3-induced protein with molecular weight of 97,000 contained peptides of the capsid and envelope protein e2 but not those of e1. two proteins with molecular weights of 78,000 and ... | 1975 | 1202249 |
| effect of cycloheximide on viral precursor protein b in sindbis virus-infected bhk cells. | the possible role of b protein, a postulated precursor of viral envelope proteins was studied in sindbis virus-infected bhk cells. although tryptic digestion of the b protein produces tryptic peptides of the viral envelope proteins it seems unlikely that b molecules accumulated in the cytoplasm of infected cells are subsequently cleaved into structural proteins. we suggest that if b is really the precursor of e1 and pe2 viral envelope proteins, the cleavage takes place on the ribosomes during th ... | 1975 | 1239649 |
| protein-bound oligosaccharides of semliki forest virus. | semliki forest virus was grown in bhk cells and labeled in vivo with radioactive monosaccharides. pronase digests of the virus chromatographed on bio-gel p6 revealed glycopeptides of a-type and b-type. (for the nomenclature see johnson, j. and clamp, j.r. (1971) biochem. j. 123, 739-745.) the former was labeled with [3h]fucose, [3h]galactose, [3h]mannose and [14c]glucosamine, the latter only with [3h]mannose and [14c]glucosamine. the three envelope glycoproteins e1, e2 and e3 were isolated by so ... | 1976 | 1247569 |
| solubilization of the semliki forest virus membrane with sodium deoxycholate. | the effects of increasing concentrations of sodium deoxycholate on semliki forest have been studied. sodium deoxycholate begins to bind to the virus at less than 0.1 mm free equilibrium concentration and causes lysis of the viral membrane at 0.9 +/- 0.1 mm free equilibrium concentration when 2.2 +/- 0.2 - 103 mol of sodium deoxycholate are bound per mol of virus. liberation of proteins from the membrane begins at 1.5 +/- 0.1 mm sodium deoxycholate and the proteins released are virtually free fr ... | 1976 | 1276219 |
| detection by western blotting of an antibody to the hepatitis c virus e1 envelope protein in sera of patients with chronic liver disease. | we detected an antibody to hcv envelope protein (e1) in sera of patients with hcv-related chronic liver diseases (20 patients with chronic hepatitis and 5 patients with liver cirrhosis) by western blotting using the fusion protein of e1 envelope protein and beta-galactosidase as an antigen. the antibody to hcv e1 (anti-hcv e1) was detected in 8 (42%) of 19 patients positive for hcv-rna (16 were positive and 3 were negative for antibody to c100-3) and in 1 (17%) of 6 patients negative for hcv-rna ... | 1992 | 1279946 |
| a preliminary map of epitopes on envelope glycoprotein e1 of hcv strain brescia. | monoclonal antibodies (mabs) directed against envelope glycoprotein e1 (gp51-54) of hog cholera virus (hcv) strain brescia have been shown to recognize four different antigenic domains a, b, c and d. epitopes of within domain a have mainly been found conserved among hcv strains, whereas epitopes within domains b, c and d are not conserved. we used transiently expressed hybrid e1 genes of hcv strains brescia and "c" to map the non-conserved epitopes on e1. epitopes in domains b and c are located ... | 1992 | 1282755 |
| t-cell hybridomas recognizing the envelope proteins of semliki forest virus: their sensitivity to endo/lysosomal protease and the antigenicity. | eight t-cell hybridomas were established from the draining lymph node of c3h mice immunized with semliki forest virus (sfv). six of them showed specificity toward viral-structure protein e2, while the remaining two clones included one with specificity to an other structural protein e1 and the other with specificity to c. the production of il-2 by the e2 protein-specific t-cell hybridomas in the presence of sfv was suppressed by treating the antigen-presenting cells (apc) with ammonium chloride r ... | 1992 | 1283995 |
| single amino acid changes in the viral glycoprotein m affect induction of alpha interferon by the coronavirus transmissible gastroenteritis virus. | transmissible gastroenteritis virus, an enteropathogenic coronavirus of swine, is a potent inducer of alpha interferon (ifn-alpha) both in vitro and in vivo. previous studies have shown that virus-infected fixed cells or viral suspensions were able to induce an early and strong ifn-alpha synthesis by naive lymphocytes. two monoclonal antibodies directed against the viral membrane glycoprotein m (29,000; formerly e1) were found to markedly inhibit virus-induced ifn production, thus assigning to m ... | 1992 | 1309909 |
| a ubiquitin conjugating enzyme encoded by african swine fever virus. | the post-translational modification of proteins by covalent attachment of ubiquitin occurs in all eukaryotes by a multi-step process. a family of e2 or ubiquitin conjugating (ubc) enzymes catalyse one step of this process and these have been implicated in several diverse regulatory functions. we report here the sequence of a gene encoded by african swine fever virus (asfv) which has high homology with ubc enzymes. this asfv encoded enzyme has ubc activity when expressed in escherichia coli since ... | 1992 | 1310934 |
| human papillomavirus type 16 and 18 gene expression in cervical neoplasias. | human papillomavirus (hpv) types 16 and 18 are strongly implicated in the generation of progressive cervical neoplasms. the viruses produce complex families of overlapping messenger rnas that are linked to differentiation, making it necessary to analyze gene expression in the context of morphology. we have developed hpv type 16 and type 18 subgenomic clones from which 3h-labeled riboprobes specific to individual mrna families can be generated in vitro. using these probes for in situ hybridizatio ... | 1992 | 1310950 |
| lectin-induced differentiation of transformed neuroretinal cells in vitro. | the orderly course of chick neuroretinal cell differentiation was disrupted in vitro by infection with a temperature-sensitive strain of the rous sarcoma virus (la29). the resulting cell culture la29nr remained mitotically active at 42 degrees c, yet rapidly adopted a transformed phenotype upon activation of the pp60v-src oncogene product at 37 degrees c. as a further indication of metabolic state, la29nr cells expressed the protooncogene product c-fos, as shown by western blot analysis. highly ... | 1992 | 1312006 |
| misfolding and aggregation of newly synthesized proteins in the endoplasmic reticulum. | as a part of our studies on the folding of glycoproteins in the er, we analyzed the fate of viral glycoproteins that have misfolded either spontaneously or through inhibition of n-linked glycosylation. newly synthesized semliki forest virus spike glycoproteins e1 and p62 and influenza hemagglutinin were studied in infected and transfected tissue culture cells. misfolded proteins aggregated in less than 1 min after release from polysomes and aberrant interchain disulfide bonds were formed immedia ... | 1992 | 1315315 |
| transactivation of the major capsid protein gene of herpes simplex virus type 1 requires a cellular transcription factor. | the purpose of this investigation was to identify and characterize the regulatory elements involved in the transcriptional activation of the beta gamma (leaky-late or gamma 1) genes of herpes simplex virus type 1 (hsv-1) by using the major capsid protein (vp5 or icp5) gene as model. gel mobility shift assays with nuclear extracts from uninfected and infected hela cells enabled us to identify two major protein-dna complexes involving the vp5 promoter. the mobilities of these two complexes remaine ... | 1992 | 1318406 |
| establishment and characterization of cell lines from human adenovirus type 12-induced murine tumors producing endogenous virus particles. | two cell lines designated ic-kms and d-kms were established from human adenovirus type 12-induced tumors of c3hf/ok mouse. the cell lines retained the characteristics of the original tumor i.e., production of numerous c-type and intracisternal a-type particles, integration of ad12 e1 region dna and amplification of the myc gene family. chromosomal analysis revealed chromosome aberrations in both ic-kms and d-kms cells. the modal chromosome number of ic-kms cells was 54 and that of d-kms cells wa ... | 1992 | 1319100 |
| an activation-dependent, t-lymphocyte-specific transcriptional activator in the mouse mammary tumor virus env gene. | transcription of the complete mouse mammary tumor virus (mmtv) proviral genome in mouse cells is controlled by a strong promoter in its long terminal repeat. in the mouse t lymphoma el4, there is a second, activation-dependent transcriptional initiation site within the envelope (env) gene, from which a short mrna is generated, encoding the open reading frame of the long terminal repeat. we now report the isolation of a segment of the mmtv env gene (called meta, for mmtv env transcriptional activ ... | 1992 | 1320198 |
| viral e1 and e2 proteins support replication of homologous and heterologous papillomaviral origins. | we have shown that e1 and e2 proteins of human papillomavirus type 11 (hpv-11) were essential to support the replication of the homologous viral origin (ori) in a transient replication assay, similar to reports on bovine papillomavirus type 1 (bpv-1). unexpectedly, matched or even mixed combinations of e1 and e2 proteins from hpv-11 or bpv-1 replicated either ori in human, monkey, and rodent cell lines of epithelial or fibroblastic lineage, albeit with varied efficiencies. either set of viral pr ... | 1992 | 1321423 |
| differentiation-induced and constitutive transcription of human papillomavirus type 31b in cell lines containing viral episomes. | the expression of viral genes during the productive life cycle of human papillomaviruses (hpv) is tightly coupled to the differentiation program of epithelial cells. we have examined transcription of hpv as a function of differentiation in an in vitro organotypic raft culture system which allows for epithelial stratification at the air-liquid interface. when cin612 cells, which contain episomal copies of hpv type 31b (hpv31b), were allowed to stratify in raft cultures, they differentiated in a m ... | 1992 | 1326657 |
| evidence that the transcriptional trans-activating function of the bovine papillomavirus type 1 e2 gene is not required for viral dna amplification in division-arrested cells. | amplification of bovine papillomavirus type 1 (bpv-1) dna in growth-arrested mouse cell cultures appears to mimic the process of induction of vegetative bpv-1 dna synthesis in cells of the stratum spinosum in productively infected bovine warts. in both cases, cells permissive for viral dna amplification express large amounts of viral e2 protein which accumulates within the cell nucleus. whereas in latently infected virus-transformed cells truncated transcriptional repressor forms of e2 predomina ... | 1992 | 1328476 |
| role of cell surface spikes in alphavirus budding. | alphaviruses mature by budding at cell surfaces. according to a prevailing hypothesis, the viral membrane protein, which is a heterodimeric protein unit, is transported to the plasma membrane (pm), where it awaits binding to the viral nucleocapsid (nc). this hypothesis predicts that the viral membrane protein heterodimers accumulate at the cell surface when expressed in the absence of ncs. we have tested this prediction by analyzing the spike protein expression phenotype of a semliki forest viru ... | 1992 | 1331511 |
| alphavirus assembly and entry: role of the cytoplasmic tail of the e1 spike subunit. | the alphavirus semliki forest virus (sfv) matures by budding at the cell surface. this process is driven by interactions of its membrane protein heterodimer e2-e1 and the nucleocapsid. the virus penetrates into new cells by an e1-mediated membrane fusion event. the e1 subunit has a short, strongly positively charged cytoplasmic tail peptide (arg-arg) which is very conserved among different alphavirus e1 proteins. in this work, we have used in vitro mutagenesis of a full-size cdna clone of sfv to ... | 1992 | 1331539 |
| [acquired peripheral facial palsy in children. current data illustrated by 66 recent personal cases]. | the authors observed 66 cases of peripheral facial palsy (pfp) in children during a 5-year period (1986-1990). bell's palsy (idiopathic facial paralysis) occurred in 26 children (39.3%), 1 month to 14.5 years old, with a complete recovery in 95% of the cases; a surgical decompression was carried out in 2 cases. the pfp was related to otitis in 16 cases (24.2%): acute otitis media (6), mastitis (4), serous otitis (5), cholesteatoma (1); the treatment was medical and surgical in all cases with com ... | 1992 | 1331969 |
| membrane fusion process of semliki forest virus. i: low ph-induced rearrangement in spike protein quaternary structure precedes virus penetration into cells. | the semliki forest virus (sfv) directs the synthesis of a heterodimeric membrane protein complex which is used for virus membrane assembly during budding at the surface of the infected cell, as well as for low ph-induced membrane fusion in the endosomes when particles enter new host cells. existing evidence suggests that the e1 protein subunit carries the fusion potential of the heterodimer, whereas the e2 subunit, or its intracellular precursor p62, is required for binding to the nucleocapsid. ... | 1992 | 1370493 |
| epitope-mapped monoclonal antibodies against the hpv16e1--e4 protein. | the human papillomavirus (hpv) e1--e4 protein is the only nonstructural late protein encoded by the virus. we have isolated three hybridomas producing monoclonal antibodies to the e1--e4 protein of hpv16, which is the hpv type most frequently associated with cervical cancer. the three antibodies (tvg 401, 402, and 403) detect adjacent epitopes within the major seroreactive region of the molecule and show no reactivity against the e4 proteins of hpv1, hpv2, hpv4, or hpv6. the e1--e4 protein migra ... | 1992 | 1371027 |
| hiv inhibitors targeted at the reverse transcriptase. | hiv inhibitors targeted at the virus-associated reverse transcriptase (rt) can be divided into two groups, depending on whether they are targeted at the substrate or nonsubstrate binding site. to the first group belong the 2',3'-dideoxynucleosides (i.e., ddc, ddi), 3'-azido-2',3'-dideoxynucleosides (i.e., azt), 3'-fluoro-2',3'-dideoxynucleosides (i.e., flt), 2',3'-didehydro-2',3'-dideoxynucleosides (i.e., d4c, d4t) and carbocyclic derivatives thereof (i.e., carbovir), 2'-fluoro-ara-2',3'-dideoxy ... | 1992 | 1371690 |
| hiv-1 reverse transcriptase inhibition by a dipyridodiazepinone derivative: bi-rg-587. | the dipyridodiazepinone derivative 6,11-dihydro-11-cyclopropyl-4-methyldipyrido[2,3-b:2',3'-e]-[1,4] diazepin-6-one (bi-rg-587) selectively inhibits human immunodeficiency virus type 1 (hiv-1) replication by suppressing hiv-1 reverse transcriptase activity. both rna- and dna-dependent polymerase associated activities of this enzyme were found to be inhibited by bi-rg-587 in a pattern dependent on the template used. the lowest ic50 values were obtained using poly(rc)-oligo(dg)12-18 and poly(da)-o ... | 1992 | 1373283 |
| localization of the virus neutralizing and hemagglutinin epitopes of e1 glycoprotein of rubella virus. | current serological assays using whole rubella virus (rv) as a target antigen for detecting rv-specific antibodies fail to define specific rv proteins and antigenic determinants such as hemagglutinin (ha) and virus-neutralizing (vn) epitopes of rubella virus. a panel of e1 deletion mutants and a subset of e1-specific monoclonal antibodies (mab) were used for the initial analysis of ha and vn epitopes of e1 glycoprotein. a peptide region (e1(193) to e1(269)) was found to contain ha and vn epitope ... | 1992 | 1379391 |
| homologous recombination of adenovirus dna in mammalian cells: enhanced recombination following uv-irradiation of the virus. | we have used adenovirus as a molecular probe to examine the recombination of viral dna following infection of mammalian cells. the technique gives a quantitative measure of homologous recombination between adenovirus type 2 (ad2) and ad5pymtr3. ad5pymtr3 is an insertion mutant of ad5 containing polyoma virus (py) dna inserted into a deleted e1 region of the ad5 genome. cells were coinfected with ad2 and ad5pymtr3 and at an appropriate time after infection, viral dna was extracted from the infect ... | 1992 | 1380653 |
| the influence of n-linked glycosylation on the antigenicity and immunogenicity of rubella virus e1 glycoprotein. | rubella virus e1 glycoprotein contains three functional n-linked glycosylation sites. the role of n-linked glycosylation on the antigenicity and immunogenicity of e1 glycoprotein was studied using vaccinia recombinants expressing e1 glycosylation mutants. expressed e1 glycosylation mutant proteins were recognized by a panel of e1-specific monoclonal antibodies in radioimmunoprecipitation, immunofluorescence, and immunoblotting, indicating that carbohydrate side chains on e1 are not involved in t ... | 1992 | 1381541 |
| amplification of dengue 2 virus ribonucleic acid sequence using the polymerase chain reaction. | the polymerase chain reaction (pcr) has been adapted to the amplification of dengue type 2 virus (den2) nucleic acid sequences. a pair of 20-mer oligonucleotides were designed and synthesized based on conserved sequence blocks of den2 strains isolated from different geographical areas. rna samples were prepared from two den2 strains, prototype new guinea c (ngc) and local isolate hainan 98 (hn98). the reverse transcription step was performed for cdna synthesis before the standard pcr procedures. ... | 1992 | 1381844 |
| cellular and humoral immune responses to rubella virus structural proteins e1, e2, and c. | better understanding of cell-mediated immune responses to rubella virus would provide the basis for the development of safe and effective vaccines against rubella and would aid in analysis of the pathophysiology of congenital rubella syndrome. we have expressed individual rubella virus structural proteins, e1, e2 and c, via vaccinia virus recombinants. using the expressed recombinant proteins as antigens, we were able to demonstrate antigen-specific lymphocyte proliferative responses in control ... | 1992 | 1383269 |
| genomic characterization and mutation rate of hepatitis c virus isolated from a patient who contracted hepatitis during an epidemic of non-a, non-b hepatitis in japan. | to investigate the genomic characterization of hepatitis c virus (hcv) isolated from patient who contracted hepatitis during an epidemic of non-a, non-b (nanb) hepatitis in shimizu city, japan, we have cloned the nucleotide sequence of the viral genome (hcv-kf) spanning the structural domain. when compared to other previously reported hcv isolates, hcv-kf showed an overall identity at the amino acid level of 90.0 to 92.1% with japanese isolates and 80.9 to 82.1% with american-like isolates. the ... | 1992 | 1383400 |
| recognition of synthetic peptides with sequences of rubella virus e1 polypeptide by antibodies and t lymphocytes. | antigenicity of rubella virus e1 polypeptide was analyzed using synthetic peptides with predicted amino acid sequences. overlapping solid-phase bound peptides were used to define antibody binding domains and a panel of free peptides to study t-cell responsiveness. several antibody-binding areas including those earlier described to contain major neutralizing epitopes were recognized by human sera positive for rubella antibodies. t-cell lines specific for rubella virus were established from 14 rub ... | 1992 | 1384533 |
| the transformation-defective adenovirus 12 host range mutant cs-1 lacks the e1a-specific 9.5s mrna and contains a second deletion in e1b. | we have further analyzed structure and expression of the e1 region of the transformation-defective adenovirus 12 (ad12) host range mutant cs-1. using cdna polymerase chain reaction analysis, the e1a region was found to give raise to five transcripts analogous to the ad12wt 13s, 12s, 11s, 10s species and the normal 9s mrna. due to loss of a splice acceptor site at position 852, the ad12wt-specific 9.5s transcript cannot be synthesized by the mutant cs-1. the fact that the virus is, however, compl ... | 1992 | 1388146 |
| adenovirus transformation revertant resistant to retransformation by e1 but not by sv40-t and hpv16-e7 oncogenes. | we have previously described a revertant cell line which expresses a dominant tumor suppressor phenotype to e1 but not to heterologous oncogenes such as c-myc, n-ras, or polyoma middle t (sircar et al. (1988) oncogene 3, 725-728). dna tumor virus oncogenes have been suggested to transform cells via the common mechanism of sequestering the rb-105 antioncoprotein. this paradigm would predict that our revertant cell line, which is resistant to retransformation by e1a, should also be resistant to th ... | 1992 | 1413500 |
| phylogenetic analysis of alphaviruses in the venezuelan equine encephalitis complex and identification of the source of epizootic viruses. | we studied the evolution of alphaviruses in the venezuelan equine encephalitis (vee) complex using phylogenetic analysis of rna nucleotide sequences from limited portions of the nsp4, e1, and 3' untranslated genome regions of representative strains. the vee complex constituted a monophyletic group of viruses (descended from a common ancestor); some serologic vee varieties such as subtype iii formed monophyletic groups while subtype i did not. subtype ii everglades and variety id enzootic viruses ... | 1992 | 1413507 |
| characterization of the antibody response to three different versions of the htlv-i envelope protein expressed by recombinant vaccinia viruses: induction of neutralizing antibody. | recombinant vaccinia viruses (rvv) designated rvv e1, rvv e2, and rvv e3, were constructed to express three different versions of the human t cell leukemia virus type i (htlv-i) envelope proteins to determine which configuration elicits an optimal antibody response. rvv e1 expressed the native htlv-i envelope proteins gp46 (surface protein) and gp21 (transmembrane protein), while rvv e2 expressed the envelope precursor with the proteolytic cleavage site deleted. the rvv e3 construct expressed on ... | 1992 | 1413516 |
| differential antibody responses to rubella virus infection in males and females. | specificities of human rubella virus (rv)-specific igg, igm, and iga antibodies for rv structural proteins (envelope e1 and e2 and capsid) and an e1 domain represented by a synthetic peptide (bch-178) were determined by immunoblot and elisa techniques in sera from rubella-infected individuals. sequential sera were obtained from 67 females and 32 males during acute and convalescent infection phases. males and females had differences in all antibody classes, especially during the early acute infec ... | 1992 | 1431244 |
| membrane fusion of semliki forest virus involves homotrimers of the fusion protein. | infection of cells with enveloped viruses is accomplished through membrane fusion. the binding and fusion processes are mediated by the spike proteins in the envelope of the virus particle and usually involve a series of conformational changes in these proteins. we have studied the low-ph-mediated fusion process of the alphavirus semliki forest virus (sfv). the spike protein of sfv is composed of three copies of the protein heterodimer e2e1. this structure is resistant to solubilization in mild ... | 1992 | 1433520 |
| molecular evidence for the origin of the widespread venezuelan equine encephalitis epizootic of 1969 to 1972. | venezuelan equine encephalitis (vee) virus is a mosquito-borne pathogen that has caused encephalitis in equine species and humans during sporadic outbreaks in the western hemisphere. the last, and most widespread, vee outbreak occurred in south america, central america, mexico and the u.s.a. (texas) during 1969 to 1972. we have cloned and sequenced the genome of a virulent vee subtype i-ab virus, strain 71-180, isolated in texas in 1971. thirty-four nucleotide differences were detected between t ... | 1992 | 1469368 |
| the rubella virus e1 glycoprotein is arrested in a novel post-er, pre-golgi compartment. | evidence is accumulating that a distinct compartment(s) exists in the secretory pathway interposed between the rough er (rer) and the golgi stack. in this study we have defined a novel post-rer, pre-golgi compartment where unassembled subunits of rubella virus (rv) e1 glycoprotein accumulate. when rv e1 is expressed in cho cells in the absence of e2 glycoprotein, transport of e1 to the golgi complex is arrested. the compartment in which e1 accumulates consists of a tubular network of smooth memb ... | 1992 | 1500424 |