| protection of mice against encephalomyocarditis virus infection by preparations of transfer rna. | preparations of bacterial transfer rna (trna), give dose-dependent protection of mice against encephalomyocarditis (emc) virus infection at up to i mg trna per mouse with maximum response when the trna is administered around 6 h before infection. protection occurs with intraperitoneally and intravenously administered trna against infections by both these routes. in some experiments significant protection occurs by single treatments of trna up to 24 h after infection with virus doses of i x ld100 ... | 1977 | 188982 |
| tunicamycin inhibits glycosylation and multiplication of sindbis and vesicular stomatitis viruses. | tunicamycin (tm), an antibiotic that inhibits the formation of n-acetylglucosamine-lipid intermediates, thereby preventing the glycosylation of newly synthesized glycoproteins, inhibits the growth of sindbis virus and vesicular stomatitis virus in bhk cells. at 0.5 mug of tm per ml, the replication of both viruses is inhibited 99.9%. noninfectious particles were not detected. all the viral proteins were synthesized in the presence of tm, but the glycoproteins were selectively altered in that the ... | 1977 | 189071 |
| possible in vitro repair of viral rna by ligase-like enzyme(s) in poliovirus-infected cells. | a soluble polymerase-template complex prepared from poliovirus-infected cells was found to incorporate radioactive utp into trichloroacetic acid-insoluble rna linearly for 8 h in the presence of atp and mg2+. radioactive ctp or gtp was not incorporated under identical conditions. nearest-neighbor analysis of the in vitro product demonstrated that atp was added to the viral rna in the form of polyadenylic acid; utp was added internally to the 3'-oh group of all four nucelotides. the data can best ... | 1977 | 189080 |
| the size and location of the poly(a) tract in emc virus rna. | encephalomyocarditis (emc) virus rna, selected by its affinity for oligo(dt)-cellulose, contains poly(a) of size : (i) about 14 nucleotide residues long, based on the percentage of radioactivity in the rna resistant to digestion by a mixture of pancreatic and t1 rnases; (ii) about 15 residues long, as measured by the ratio of the amount of terminal adenosine to internal adenylic acid in isolated poly(a); and (iii) in the range 12 to 45 residues, the majority of tracts being about 16 to 18 residu ... | 1977 | 190347 |
| the translation of globin messenger rna with use of muscle initiation factors. | the ability of embryonic chicken muscle initiation factors to translate rabbit globin messenger rna in an efficient, fractionated cell-free system has been examined. although muscle factors stimulate leucine incorporation to only 15--35% the levels achieved with rabbit reticulocyte initiation factors, they synthesize more than one globin chain per mrna molecule and both alpha and beta globin are produced. increasing the ribosome concentration and adding the polyamine spermidine to the system pro ... | 1977 | 191079 |
| comparison of antiviral and antitumor activity of activated macrophages. | | 1977 | 191199 |
| bis-basic-substituted polycyclic aromatic compounds. a new class of antiviral agents. 8. bis-basic derivatives of carbazole, dibenzofuran, and dibenzothiophene. | a series of bisalkamine esters, bis-basic ethers, and bis-basic ketones of carbazole, n-ethylcarbazole, dibenzofuran, and dibenzothiophene was synthesized and evaluated for antiviral activity. the series also included two bis-basic alkanes of n-ethylcarbazole and one bis-basic carboxamide of dibenzofuran. structure-activity relationships indicated that within the carbazole and n-ethylcarbazole series the bisalkamine esters gave the most active derivatives while the bis-basic ketone derivatives o ... | 1977 | 191610 |
| [the lysosomes during the course of the emc virus induced damage of the myocardial cell (author's transl)]. | | 1976 | 192012 |
| light and electron microscopic studies of "nude" mice cns after subcutaneous administration of the e variant of the encephalomyocarditis (emc) virus. | sixteen 3 month old "nude" mice, 24 of their litter mates and 30 swiss mice were injected subcutaneously with 0.1 ml suspension of the e variant of the encephalomyocarditis (emc) virus. while the mortality rate of the litter mates and swiss mice during 5-7 days after inoculation was more than 40%, none of the "nude" mice died during the experiment. the surviving animals were sacrificed at 24 h intervals from day one to seven days after injection. brain suspensions assayed for the presence of the ... | 1977 | 192039 |
| experimental herpes simplex virus type 1 encephalitis: treatment with 5-trifluoromethyl-2'-deoxyuridine. | 5-trifluoromethyl-2'-deoxyuridine (f(3)dthd) was evaluated for its neurotoxicity and for its ability to increase the life span of mice injected intracerebrally with herpes simplex virus type 1 (hsv-1) and f(3)dthd simultaneously. f(3)dthd showed no neurotoxicity at the highest concentration tested (100 mg/kg). mice injected intracerebrally with hsv-1 died within 5 days postinfection. however, all mice injected concurrently with hsv-1 and 100 mg of f(3)dthd per kg lived through the termination of ... | 1977 | 192143 |
| [potentiating effect of cycloheximide on viral interference]. | the degradation of the antiviral state can be delayed in vitro by antimetabolites, when added between 5-7 hours after interferon. we explore in this chronological order whether antiviral resistance induced by newcastle disease virus (n.d.v.) in vivo could be modified by an antimetabolite. cycloheximide was selected for this study because of its reversible biological effect and lack of toxicity in our experimental conditions. the model system employed was syrian hamsters, using n.d.v. as an inter ... | 1977 | 192485 |
| [immunologic demonstration of a cellular component in the composition of the rna polymerase of encephalomyocarditis virus]. | | 1977 | 192524 |
| [denaturation maps of the replicative form of rna of 2 picornaviruses]. | | 1977 | 192525 |
| effect of virus infection and cycloheximide treatment on the labeling of cellular phospholipids with 32 p. | the total amount and the relative proportions of labeled phospholipids were studied in chorioallantoic membrane cells (cam), chick embryo cells (cec) and l cells which were either infected with newcastle disease virus (ndv), fowl plague virus (fpv) and mouse encephalomyocarditis (emc) virus or treated with cycloheximide. in productively infected or nonproductively infected cells, the total amount of labeled phospholipids was not altered, but the relative proportions of individual phospholipids w ... | 1977 | 192694 |
| suppressed response to interferon inducation in mice infected with encephalomyocarditis virus, semliki forest virus, influenza a2 virus, herpesvirus hominis type 2, or murine cytomegalovirus. | mice infected with encephalomyocarditis virus, semliki forest virus, influenza a2 virus, herpesvirus hominis type 2, or murine cytomegalovirus developed a state of hyporeactivity to interferon induction. in general, the capacity of infected animals to produce interferon in response to inducers became progressively impaired during the course of infection. the severity and time of onset of hyporeactivity, however, were dependent upon the inducer and the nature of the viral infection. during viral ... | 1977 | 192804 |
| immunomodulation of host resistance to experimental viral infections in mice: effects of corynebacterium acnes, corynebacterium parvum, and bacille calmette-guérin. | resistance to a representative group of experimental virual infections in mice was significantly enhanced by nonspecific modulation of host defense mechanisms. corynebacterium acnes, corynebacterium parvum, and bacille calmette-guérin were effective in enhancing host resistance. animals treated seven to 10 days before inoculation of virus were protected against a lethal infection with herpesvirus hominis type 2, encephalomyocarditis virus, murine cytomegalovirus, or semliki forest virus. the pro ... | 1977 | 192811 |
| [fusion of encephalomyocarditis virus double-stranded rna]. | | 1977 | 193583 |
| enteroviruses other than poliovirus. | the role of enteroviruses in certain specific disease--cardiac disease, nephritis, diabetes, and hemorrhagic conjunctivitis--is examined. it has now been well documented that coxsackievirus b (types cb1 through cb5 but not cb6) is the main pathogen involved in various clinical forms of viral heart disease. coxsackievirus a (ca4 and ca16) and echovirus (types 9 and 22) may also be associated with viral heart disease. in regard to the etiologic role of enteroviruses in nephritis, pancreatitis, and ... | 1976 | 193602 |
| increase in lipid fluidity of cellular membranes induced by adsorption of rna and dna virions. | changes in the dynamic behavior of membrane lipids of mammalian cells induced by adsorption of animal viruses were quantitatively monitored by fluorescence polarization analysis with the aid of the fluorescent probe 1,6-diphenyl 1,3,5-hexatriene embedded in the surface membrane lipid core of intact cells. adsorption of encephalomyocarditis, west nile, and polyoma viruses to hamster (baby hamster kidney) and mouse (3t3) cells is accompanied by a rapid and significant increase in the degree of flu ... | 1977 | 194057 |
| a sensitive interferon assay for many species of cells: encephalomyocarditis virus hemagglutinin yield reduction. | | 1977 | 194253 |
| [degradation by phytohemagglutinin of the antiviral state induced by interferon]. | phytohaemagglutinin (pha m and p forms), when added to l 929 cells previously treated by murine interferon, degrades the antiviral state and restores virus sensitivity in the cells. this degradation depends on the amount of the lectin, the contact period with the cell and the presence of pha membrane receptors. the importance of membrane configuration not only in the induction but also in the maintenance of the antiviral state is discussed. | 1977 | 194719 |
| [does the diabetes caused by viral infection in mice depend on immune reactions?]. | normal dba2 mice become highly diabetic after infection with the emc virus. but 500 r x-irradiation before infection inhibits the increase of mean blood glucose levels thus indicating the participation of immune reactions in the appearance of diabetes. | 1977 | 194722 |
| high sensitivity of c3h mouse embryo-derived cell line to the antiviral activity of interferon. | | 1977 | 195290 |
| effects on interferon of heavy metal excess and zinc deficiency. | near toxic concentrations of cadmium sulfate, mercuric chloride, and nickel sulfate reduced interferon action in tissue cultures, but increased intake by the intact mouse of lead acetate and mercuric chloride did not reduce interferon action. lead and nickel given orally inhibited the protective activity of newcastle disease virus against encephalomyocarditis virus-induced mortality, whereas cadmium, mercury, cobalt sulfate, and sodium arsenite given orally and deficiency of zinc did not influen ... | 1977 | 195499 |
| effects of heavy metals and of deficiency of zinc on mortality rates in mice infected with encephalomyocarditis virus. | salts of cadmium, lead, mercury, and nickel given orally to mice increased encephalomyocarditis virus-induced mortality rates. although lead was the least toxic of the 4 metals, it enhanced the mortality the most. concentrations of mercuric chloride as low as 0.01 ppm intensified the mortality; a minimal concentration that resulted in no effect was not ascertained. zinc deficiency caused pronounced retardation of growth in young mice, but it did not influence mortality due to encephalomyocarditi ... | 1977 | 195500 |
| encephalomyocarditis virus rna. ii. polyadenylic acid requirement for efficient translation. | differentially polyadenylated subpopulatons of encephalomyocarditis (emc) viral rna were isolated by affinity chromatography on oligodeoxythymidylic acid-cellulose. translation of these rna fractions in several in vitro protein-synthesizing systems, isolated from ehrlich ascites tumor cells, demonstrated that poly(a)+emc viral rna was translated two to three times more efficiently than poly(a)-emc viral rna. sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of the polypetides sy ... | 1977 | 196111 |
| chemical structure of attachment sites for viruses on human erythrocytes. | | 1977 | 196216 |
| encephalomyocarditis virus antibodies in sera from apparently normal pigs. | antibodies which neutralise and precipitate encephalomyocarditis virus habe been found in the serum of more than 28 per cent of normal pigs in britain. neutralising activity was found in association with several size classes of antibody. | 1977 | 196385 |
| virus-induced diabetes mellitus. | | 1977 | 196570 |
| enhancement of virus growth produced by thiols and disulphides. | several thiols and disulphides have been found able both to shorten the latency phase and to increase the growth of several virus strains in cell cultures. | 1977 | 196894 |
| antiviral activity of bovine interferons on primate cells. | potent preparations of bovine leucocyte and fibroblast interferons had substantial antiviral activity on monkey cells and low activity on human cells. thus, interferon from a 'lower' phylogenetic species can have considerable antiviral activity in primate cells, but not all primate cells are equally sensitive. | 1977 | 197203 |
| protection of mice against encephalomyocarditis virus infection by chemically modified transfer rnas. | periodate or nitrous acid treatment greatly decreases the ability of unfractionated escherichia coli transfer rna (trna) to be aminoacylated by trna-synthetases but these treatments do not affect their antiviral activity against encephalomyocarditis virus infection of mice. bisulphite treatment of e. coli trna reduces its ability to be aminoacylated by 20% and has no effect on antiviral activity. bromine water treatment of trna under conditions causing extensive base modifications eliminates ami ... | 1977 | 197205 |
| virus induced diabetes and the immune system. i. suggestion that appearance of diabetes depends on immune reactions. | the participation of immune reactions in the emc virus induced diabetes of the mouse was studied by immunosuppression with 500 r sublethal x-irradiation or 120 mg/kg asta 5122, a cyclophosphamide derivative. average glucose levels after x-irradiation and infection remained normal, while virus, infected, otherwise untreated mice, had significantly higher mean glucose levels, indicating that immune reactions are necessary for the development of virus induced diabetes. immune suppression by the cyc ... | 1977 | 198323 |
| islet transplantation. | | 1977 | 198915 |
| [pathologic anatomy of experimental diseases of small laboratory animals caused by encephalomyocarditis virus (strain emk-70)]. | the results of pathomorphological investigation of the disease in small laboratory animals experimentally induced by the emc-70 strain of encephalomyocarditis virus isolated from monkeys are presented. irrespective of the mode of virus injection, the newborn and juvenile mice developed some lesions in the brown fat, transverse-striated muscles, as well as in the brain and heart. in guinea pigs the changes were characterized by the development of severe myocarditis and encephalitis accompanied by ... | 1977 | 199295 |
| pancreatic insulin and glucagon content and secretion after infection of mice with emc virus [proceedings]. | | 1977 | 199485 |
| localization of the restrictive event of emc virus replication in semi-permissive monkey and monkey-mouse hybrid cells. | encephalomyocarditis (emc) virus replication was investigated in permissive mouse mks cells, semi-permissive monkey cv1 cells, and in somatic monkey-mouse mkcviii hybrid cells whose permissiveness is under the negative control of the simian genome. we found that in cv1 cells the synthesis of both single- and double-stranded virus rnas was restricted. in contrast, in semi-permissive hybrid cl4/3 cells only the single-stranded virus rna was synthesized in small amounts, whereas the double-stranded ... | 1977 | 199701 |
| antibody to encephalomyocarditis virus in juvenile diabetes. | | 1977 | 199838 |
| preweaning mortality in the pig. pathological findings in piglets dying between birth and weaning. | during a survey of preweaning mortality 538 piglets which died between birth and weaning were autopsied. the results of laboratory examinations permitted a division of the findings into a number of syndromes which were considered to be associated with the immediate cause of death. the non-infectious conditions such as trauma, starvation and suffocation were the most common. seventy-eight piglets were included in the trauma group because of depressed cranial bone fractures or visceral rupture lea ... | 1977 | 200212 |
| encephalomyocarditis virus infection of captive elephants. | four african elephants at each of 2 widely separated zoologic gardens in florida died following a fulminating illness. tissue suspensions obtained from an elephant from each of the zoologic gardens were inoculated into newborn mice, 3- to 4-week-old mice, and buffalo green monkey and baby hamster kidney cell cultures. encephalitis and myocarditis developed in the mice. the cell cultures were destroyed within 24 to 72 hours, and intracytoplasmic viral inclusions were observed in infected cells by ... | 1977 | 200596 |
| virus-induced diabetes mellitus: viii. passage of encephalomyocarditis virus and severity of diabetes in susceptible and resistant strains of mice. | the diabetogenic capacity of the m-variant of encephalomyocarditis (emc) virus was markedly diminished after passage in mouse kidney cell cultures. one passage in mice fully restored this capacity. virus harvested after five passages in either susceptible (swr/j) or resistant (c57bl/6j) strains of mice was capable of producing diabetes in susceptible swr/j mice but not in resistant c57bl/6j mice. resistance was not overcome by inoculating mice with high concentrations of virus. immunofluorescenc ... | 1977 | 200705 |
| structural studies of encephalomyocarditis virus rna both in situ and in free solution. | the secondary structure of encephalomyocarditis (emc) virus rna has been studied in situ and in free solution by absorbance-temperature relationships and by circular dichroism (cd). extracted emc virus rna melts reversibly and has a hypochromicity of about 20%; analysis of cd spectra and formaldehyde treatment suggests that approx. 60% of the nucleotides are involved in base-pairing at 25 degrees c. it is shown that the rna within the virus particle is less structured than when it exists in free ... | 1977 | 200710 |
| the attachment of encephalomyocarditis virus to erythrocytes from several animal species. | | 1977 | 201092 |
| emc viral infection of the coronary blood vessels in newborn mice: viral vasculitis. | the coronary arteries, veins and capillaries of newborn mice experimentally infected with encephalomyocarditis (emc) virus were studied histologically and electronmicroscopically. damage to these coronary vessels was patchy. some lesions were extensive, particularly when adjacent to areas of myocardial damage. the histological findings consisted of swelling of adventitial and endothelial cells pyknosis, and polymorphonuclear leucocyte and round cell infiltration. histological and ultrastructural ... | 1977 | 201264 |
| effect of impulsin treatment of interferon production and antiviral resistance of mice. | the effect of n-(2-hydroxyethyl)-palmitamide (impulsin, spofa)--an active endogenous compound which is recommended for preventing virus infection of the respiratory tract--on interferon production in mice stimulated with double stranded rna and on the course of disease caused by encephalomyocarditis virus (emc) was studied. impulsin itself did not stimulate interferon production in mice treated per os or intravenously. but repeated application of this drug per os induced a macrophage activation, ... | 1977 | 202215 |
| physicochemical characteristics of ime-inhibitor of interferon activity from mouse embryo tissues. | further investigation with the inhibitor of interferon activity (ime) isolated from mouse embryo tissue is reported. the present results bring some new data concerning the physiochemical properties of the interferon antagonist. it is not dialysable, not sensitive to trypsin, lysozyme, hyaluronidase, rnase and ph 2, but is sensitive to ph 10 and neuraminidase. concentrated and partly purified tissue antagonist of interferon was separated on a column with sephadex g 100. three distinct, well separ ... | 1977 | 202216 |
| nucleic acid as interferon inducer. its antiviral and antitumor activity. | the results of the present study have demonstrated that dsrna obtained in the system e. coli--bacteriophage is an interferon inducer and possesses antiviral and antitumoral activities. | 1977 | 202217 |
| the influence of immunization on the production of interferon in vivo and in vitro. | the present study was undertaken to compare the production of interferon by immunized mice in response to different viral inducers. porton mice were immunized with ndv or a/wr11/57 virus by injecting 6-week-old animals with virus on days 1, 7, and 14. the interferon response was investigated 3 weeks later. compared with controls, the a-immunized mice after stimulation in vivo, produced more interferon when ndv was used as inducer. it was shown in sera as well as in washings of peritoneal cells. ... | 1977 | 202218 |
| virus infection of murine teratocarcinoma stem cell lines. | | 1977 | 202395 |
| encephalomyocarditis virus rna. iii. presence of a genome-associated protein. | a low-molecular-weight protein was found to be associated with intact 35s rna isolated from purified encephalomyocarditis virus. this protein was positively charged at ph 3.5, sensitive to proteinase k treatment, and labeled with either 3h-amino acids or 32pi. | 1978 | 202751 |
| [stimulation of mouse encephalomyocarditis virus reproduction by non-multiplying poliomyelitis virus in several transplantable tissue culture lines]. | reproduction of mouse encephalomyocarditis virus (emc) was studied in 5 continuous primate cell lines: hela, fl, detroit-6, p/7, and mio inoculated with guanidine-dependent variant of poliomyelitis virus in the absence of guanidine. poliomyelitis virus stimulated emc virus reproduction in all cell lines under study. this stimulation effect was studied at length in hela and mio cells. in hela cells, stimulation was observed at a low and moderate multiplicity of infection of emc virus but not at a ... | 1977 | 203116 |
| [effective cell-free system for translation of encephalomyocarditis virus rna]. | | 1978 | 203436 |
| enhanced resistance against encephalomyocarditis virus infection in mice, induced by a nonviable mycobacterium tuberculosis oil-droplet vaccine. | female c57b1/10 mice injected intravenously (i.v.) with nonviable mycobacterium tuberculosis jamaica cells associated with oil-droplet emulsions (wcv) were highly resistant to the i.v. injection of encephalomyocarditis virus (emcv). resistance to infection (87% survival) was detected from 1 week to at least 12 weeks after injection of wcv. mice vaccinated i.v. also were resistant to intraperitoneal, subcutaneous, or intramuscular virus challenge, but were not resistant to intracranial challenge. ... | 1978 | 203533 |
| requirement for macrophages for interferon to be effective against encephalomyocarditis virus infection of mice. | suppression of macrophages in mice by treatments with silica or auro-thiomalate (myocrisin) reduced production of serum interferon by polyriboinosinic acid:polyribocytidylic acid by 85 to 90%, indicating that this double-stranded polynucleotide caused interferon production primarily in macrophages. suppression of macrophages in mice by silica or myocrisin treatment did not significantly affect the susceptibility of mice to encephalomyocarditis virus, although at virus doses around 20 times the 5 ... | 1978 | 203537 |
| variable effect of encephalomyocarditis virus on host defense mechanisms. | a number of viruses have been shown to suppress a variety of host defense mechanisms. to further define the effect of a viral infection on host resistance, a number of parameters were examined during the course of a lethal encephalomyocarditis virus infection of mice. the peripheral lymphocyte count, the induction of interferon in spleen cells by newcastle disease virus, and the proportion of b cells in the spleen were all decreased or suppressed. in contrast, the responsiveness of spleen lympho ... | 1978 | 203538 |
| observations on the natural history of encephalomyocarditis virus. | | 1978 | 204205 |
| the prevalence of encephalomyocarditis virus neutralizing antibodies among various human populations. | the prevalence of encephalomyocarditis virus (emc) antibodies among selected human populations in various regions of the world was determined by the plaque reduction neutralization method. antibody rates among children ranged from 1.0 to 33.9%, while those among adults varied from 3.2 to 50.6%. no differences between sexes were found in the frequency of emc infection. the pattern of age-specific antibody rates observed among the study populations suggests that emc infection occurs primarily duri ... | 1978 | 204206 |
| complete translation of encephalomyocarditis virus rna and faithful cleavage of virus-specific proteins in a cell-free system from krebs-2 cells. | | 1978 | 204520 |
| picorna- and togavirus infection of cells detected by gas chromatography. | viral infection of cells causes chemical and metabolic changes, which can be detected by gas chromatography (gc) of ether extracts of supernatant fluids and cell homogenates before any significant damage to the cells is observable microscopically. the characteristic and specific gc patterns obtained from bhk-21 and vero cell cultures infected with encephalomyocarditis, polio, echoviruses, and a togavirus make it possible to distinguish between these infecting viruses. the appearance of 1 or 2 co ... | 1977 | 204744 |
| enhanced virus replication in mammalian cells exposed to commercial emulsifiers. | mammalian cell cultures were used to show that a variety of commercial emulsifiers are capable of enhancing the sensitivity of these cells to infection with several viruses. some emulsifiers were not active as enhancers, and those viruses that responded to the enhancing emulsifiers were single-stranded ribonucldic acid viruses. the double-stranded viruses that were tested were nonresponders. | 1978 | 205172 |
| synthesis of as-triazines as potential antiviral agents. | four acenaphtho[1,2-e]-as-triazines and 11 5,6-diaryl-as-triazines, all substituted with an aliphatic or aromatic amino function in the 3-position, were synthesized. two acenaphthotriazines were active against vesicular stomatitis virus in tissue culture. | 1978 | 205646 |
| membrane leakiness after viral infection and a new approach to the development of antiviral agents. | viral development induces changes in the permeability properties of the plasma membrane of the host cell. here it is shown that, because of this leakiness, inhibitors of protein synthesis normally impermeable to uninfected cells are able to enter infected cells and thereby specifically inhibit viral protein synthesis. | 1978 | 205795 |
| synthesis of an oligonucleotide inhibitor of protein synthesis in rabbit reticulocyte lysates analogous to that formed in extracts from interferon-treated cells. | a heat-stable, low-molecular-weight inhibitor of protein synthesis is formed on incubation of haemin-supplemented rabbit reticulocyte lysates with atp and double-stranded rna (dsrna). it inhibits the translation of both added encephalomyocarditis virus rna (emc rna) and endogeneous messenger rna in reticulocyte lysates and mouse l-cell extracts. the enzyme responsible for the synthesis of the inhibitor binds to dsrna and can be purified on a column of poly(i).poly (c) bound to an inert support. ... | 1978 | 206430 |
| translation of encephalomyocarditis virus rna in vitro yields an active proteolytic processing enzyme. | in contrast to other cell-free translation systems, the mrna-dependent reticulocyte lysate can translate encephalomyocarditis virus rna efficiently and completely when supplemented with heterologous trna. cleavage of the nascent polypeptide chain occurs, and one of the translation products appears to be a specific proteolytic enzyme which correctly processes the primary products. the identity of the proteins made in vitro was verified by comparison with infected cell proteins on dodecylsulphate/ ... | 1978 | 206439 |
| stability of neurotropic mouse hepatitis virus (jhm strain) during chronic infection of neuroblastoma cells. | a line of mouse neuroblastoma cells which was chronically infected with the neurotropic strain (jhm) of mhv, a member of the coronavirus group, was established. these cells, designated nj, exhibited typical mhv cytopathic effects (cpe) at all passage levels along with the continual production of infectious virus. most cells were positive for viral antigen by immunoflourescence. viral particles consistent with the morphology of mhv were found by electron microscopy. the uninfected neuroblastoma c ... | 1978 | 207241 |
| prostaglandin restoration of the interferon response of hyporeactive animals. | virus-infected animals and those bearing various types of malignancies progressively lose the ability to respond to interferon inducers. the interferon response of virus-infected animals could be restored to normal levels when inducers were administered with certain prostaglandins. this suggests that prostaglandins may enhance the therapeutic efficacy of interferon inducers as antiviral and antineoplastic agents. | 1978 | 208154 |
| virus-induced diabetes mellitus. x. attachment of encephalomyocarditis virus and permissiveness of cultured pancreatic beta cells to infection. | | 1978 | 208240 |
| a cell-free model of the encephalomyocarditis virus-induced inhibition of host cell protein synthesis. | | 1978 | 208265 |
| effect of polyadenylic acid on the functional half-life of encephalomyocarditis virus rna during translation. | | 1978 | 208550 |
| [ribonucleoproteins containing messenger ribonucleic acid in virus infected krebs ii ascitic carcinoma cells]. | | 1978 | 208664 |
| evidence for a single locus controlling susceptibility to virus-induced diabetes mellitus. | | 1978 | 209341 |
| rna-binding properties of nonstructural polypeptide g of encephalomyocarditis virus. | | 1978 | 209621 |
| picornaviridae: second report. | | 1978 | 210136 |
| the genome-linked protein of picornaviruses. iv. difference in the vpg's of encephalomyocarditis virus and poliovirus as evidence that the genome-linked proteins are virus-coded. | | 1978 | 210567 |
| isolation and preliminary characterization of temperature-sensitive mutants of encephalomyocarditis virus. | thirty temperature-sensitive mutants of encephalomyocarditis virus have been isolated and partially characterized. fifteen of these mutants are phenotypically rna+ thirteen are rna-, and two are rna +/-. six rna + mutants, one rna- mutants, and one rna +/- mutant have virions which are more thermosensitive at 56 degree c than the wild-type virions. hela cells infected at the nonpermissive temperature with any of the rna+ mutants produced neither infective nor noninfective viral particles. the cl ... | 1978 | 211249 |
| initiation activity of emc virus rna, binding to initiation factor eif-4b and shut-off of host cell protein synthesis. | | 1978 | 211427 |
| viral resistance to interferon. | | 1977 | 211661 |
| comparison of initiation rates of encephalomyocarditis virus and host protein synthesis in infected cells. | the relative initiation rates for encephalomyocarditis virus mrna and host mrna's in infected cells were measured using two independent techniques. in both cases the results showed that viral mrna initiates at a much higher rate than host mrna's. this difference was observed midway in the infectious cycle, well before virus-induced cytopathic effects (leakage of low-molecular-weight metabolites, failure to exclude trypan blue) were apparent. these results confirm that encephalomyocarditis viral ... | 1978 | 212586 |
| specificity of interferon action in protein synthesis. | inhibitors of elongation steps in protein synthesis such as cycloheximide and anisomycin mimic interferon treatment in that they specifically inhibit the synthesis of certain viral proteins. these specific effects are seen only at very low concentrations of the antibiotics, under conditions where host cellular protein synthesis, as well as cell viability, are not severely reduced. a qualitatively as well as quantitatively close correlation between the effects of the two types of agents has been ... | 1978 | 212587 |
| extraction and fingerprint analysis of simian virus 40 large and small t-antigens. | a study of simian virus 40 (sv40) t-antigens isolated from productively infected cv1 cells using a variety of different extraction procedures showed that under some conditions the highest molecular weight form of t-ag (large-t) isolated comigrated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with large-t from sv40-transformed h65-90b cells. other faster-migrating forms of large-t are probably generated during the extraction procedure by a protease which is active at low ph, and s ... | 1978 | 212599 |
| passive transfer of virus induced diabetes mellitus with spleen cells. | the study describes passive transfer of diabetes mellitus by transplantation of spleen cells from donor mice infected with a diabetogenic encephalomyocarditis virus. inbred normal c57 mice were used as both donors and recipients, and other recipients were c57 athymic, nude mice. transplants were made in two series after 12 and 22 days duration of infection of the donors, respectively. all recipients became diabetic. the possibility of virus transfer with the spleen cell transplant is discussed, ... | 1978 | 212930 |
| cell-mediated immunity to murine cytomegalovirus. | cell-mediated immunity to murine cytomegalovirus (cmv) was tested by an in vitro lymphocyte proliferation assay. cmv antigen was prepared from infected mouse embryo fibroblasts by ultracentrifugation. control antigen was prepared in a similar fashion from uninfected fibroblasts. splenic lymphocytes from cmv-infected mice underwent significant proliferation when incubated with cmv antigen. lymphocytes from uninfected mice did not proliferate when incubated in vitro with cmv antigen. the prolifera ... | 1978 | 213500 |
| [translation of double-helical rna in a cell-free protein-synthesizing system]. | | 1978 | 214283 |
| [protein detected in a structure containing cellular mrna during encephalomyocarditis virus infection]. | | 1978 | 214284 |
| viruses and the pathogenesis of diabetes mellitus. | | 1978 | 214368 |
| photoinactivation of the encephalomyocarditis virus. | encephalomyocarditis virus was photoinactivated by a dilution of 1:30,000 neutral red and 70 minutes exposure to light. a dye inactivation of the emc virus is possible without destruction of its antigenicity. the emc virus vaccine induced a good immunity response in mice; we did not find any infectious virus. | 1978 | 215108 |
| the influence of the major histocompatibility complex (h-2) on experimental diabetes in mice. | mice with different histocompatibility loci on an identical background genome (congenic resistant lines of mice) were used to study the possible influence of the histocompatibility complex on experimental diabetes. the major histocompatibility complex (h-2) was not found to influence the diabetogenic effect of encephalomyocarditis (emc) virus. in contrast the glucose intolerance following heterologous and homologous immunization with pancreatic antigens appeared h-2 influenced. antibodies agains ... | 1979 | 215479 |
| induction of enhanced resistance against encephalomyocarditis virus infection of mice by nonviable mycobacterium tuberculosis: mechanisms of protection. | nonviable mycobacterium tuberculosis strain jamaica suspended in oil-droplet emulsions was used to enhance resistance of mice against encephalomyocarditis virus (emcv). the mycobacteria-injected mice were significantly resistant to 50,000 50% lethal doses of emcv. similar concentrations of virus in plasma of normal and mycobacteria-injected mice from 1 to 120 min after injection of emcv showed that resistance was not a result of rapid elimination of virus from the circulation. furthermore, survi ... | 1978 | 215550 |
| [course of antibodies in mice, rats and pigs following administration of encephalomyocarditis viruses]. | | 1978 | 216192 |
| synthesis and breakdown of pppa2'p5'a2'p5'a and transient inhibiton of protein synthesis in extracts from interferon-treated and control cells. | incubation of the mouse l-cell-free system with a concentration of pppa2'p5'a2'p5'a [(2'-5')an] just sufficient to inhibit protein synthesis results in formation of a high-molecular-weight, heatlabile inhibitor and enhanced ribonuclease activity and in the rapid breakdown of (2'-5')an to atp. the (2'-5')an-enhanced ribonuclease activity is also unstable and in the absence of a (2'-5')-an-regenerating system inhibiton of protein synthesis is transient. although interferon treatment enhances the s ... | 1978 | 216547 |
| virus-induced diabetes in mice: a quantitative evaluation of islet cell population by immunofluorescence technique. | the endocrine cell populations of pancreatic islets in encephalomyocarditis (emc)-virus infected mice were assessed quanititatively by immunofluorescence using specific antisera against 4 islet hormones. a marked reduction of the volume of insulin-containing (b-) cells (up to one tenth of control values) was observed at all stages studied in the hyperglycaemic mice. this was accompanied by the inversion of the normal ratio between b- and non b-cells. the volume of the latter cell types was also ... | 1978 | 216598 |
| [melting and reassociation of double-stranded rna of the encephalomyocarditis virus]. | the processes of melting and reassociation of double-stranded rna in dimethylsulfoxide were studied. the addition of a small amount of licl results in great results in great reduction of tm (temperature of melting), whereas the nacl produces the opposite effect. it is suggested, that licl coordinates the molecules of h2o, reducing their activity, and consequently destabilises dsrna. mild conditions for melting and reassociation of rna can be created. it was found that under optimal conditions fo ... | 1979 | 217455 |
| [reproduction of murine encephalomyocarditis virus in enucleated krebs 2 ascitic carcinoma cells]. | enucleated cells of ascites carcinoma krebs 2 (cytoplasts) were prepared. the cells were centrifugated for this purpose in a discontinuous ficoll density gradient containing cytochalasine b. the cytoplasts formed turbid bands in phycol solution at the density of 1.037--1.053 g/ml. the cytoplasts failed to synthesize rna, but proteins were synthesized for several hours. encephalomyocarditis virus replicated in the ascites carcinoma cytoplasts, but its yield was 10 to 100-fold lower as compared to ... | 1979 | 217469 |
| effect of ammonium salts on the interferon-induced antiviral state in mouse l cells. | the addition of ammonium salts to cells treated with interferon prevents the development of the antiviral state and destroys it when already established. this treatment does not seem to act on the binding of interferon to the cells but blocks a further step of activation on the cell membrane. the anti-interferon effect of ammonium salts is reversible with a complete recovery of the antiviral state. it is postulated that these salts may stabilize the interferon-receptor complex and thus prevent t ... | 1978 | 217950 |
| enhancement of infectivity of encephalomyocarditis virus rna by amphotericin b methyl ester. | the methyl ester of amphotericin b (ambme), a macrolide polyene antibiotic, enhanced the infectivity of encephalomyocarditis (emc) virus rna for l929 cells. ambme alone (100 microgram/ml) resulted in increases in emc virus rna infectivity of 10- to 100-fold. addition of deae dextran at concentrations (5 microgram/ml), which alone slightly suppressed emc virus rna infectivity, further augmented the effects of ambme (augmentation in infectivity up to 750-fold). ambme did not inhibit rnase, did not ... | 1979 | 217959 |
| comparative studies on the genomes of some picornaviruses: denaturation mapping of replicative form rna and electron microscopy of heteroduplex rna. | | 1979 | 218342 |
| selective inhibition of protein synthesis in virus-infected mammalian cells. | a number of translation inhibitors were tested for their effects on both control and encephalomyocarditis virus-infected mouse 3t6 cells. the virus-infected cells were specifically inhibited by gougerotin, edeine, and blasticidin s, whereas these drugs failed to penetrate into uninfected cells. inhibition of infected cells by gougerotin became apparent when the synthesis of viral proteins commenced, suggesting that the latter process is accompanied by a permeability change in the cells that allo ... | 1979 | 219211 |
| encephalomyocarditis virus-induced diabetes mellitus treated by islet transplantation. | there is considerable evidence that at least some cases of juvenile onset diabetes mellitus in humans are a result of viral infection. viral-induced diabetes in mice may provide an experimental counterpart more similar to the clinical situation than chemical-induced diabetes. our experiments in such mice indicate that islet transplantation is effective in ameliorating viral-induced diabetes and is encouraging for ultimate clinical application of islet transplantation to juvenile onset insulin-de ... | 1979 | 219567 |
| heterospecific activity of rat interferon. | in the experiments performed in vitro and in vivo it has been found that the rat and rat embryo fibroblasts cultured in vitro after the induction with virus produce interferon which displays the antiviral activity not only in the homologous cells but also in the heterologous ones. when analysed by chromatography on sephadex g-100 it was shown that the rat serum contains two interferon populations differing in the molecular weight and both active in the homologous and heterologous cells. the inte ... | 1978 | 219806 |
| studies on the mode of action of ime--an inhibitor of interferon activity from mouse embryo tissues. | ime--inhibitor of interferon activity from mouse embryo tissues does not inactive interferon by direct contact; it does not inhibit the production of interferon and it does not affect the replication of challenge virus. ime shows no species-specific activity since it exhibits anti-interferon action not only in homologous interferon system but also in the heterologous rat, chick and human interferon systems. the interferon-induced antiviral state as well as the efficient cell's metabolism appear ... | 1978 | 219807 |