| new agents active against african swine fever virus. | actinobolin, atropine, carrageenan, megalomycin c, suramin, and tetracenomycin c were tested for their activity against african swine fever virus replication. both viral inhibitory potency and cytotoxicity were investigated. megalomycin c, suramin, atropine, and carrageenan exhibited significant activity. megalomycin c was the most active of the four agents with respect to the concentration of compound that blocked the formation of infectious virus by 50%. suramin was the next most active agent ... | 1986 | 3717934 |
| african swine fever virus gene expression in infected vero cells. | polypeptides synthesized in vero cells infected with african swine fever virus (asfv) can be divided into early and late classes on the basis of their sensitivity to cytosine arabinoside. as asfv does not inhibit cell protein synthesis until late in infection, immunoprecipitation was used to identify virus-specific polypeptides. eighteen early and 15 late polypeptides were detected by polyacrylamide gel electrophoresis. early polypeptides can be further divided into those which are transiently e ... | 1986 | 3723111 |
| inhibition of african swine fever infection in the presence of immune sera in vivo and in vitro. | in assay cultures, sera from african swine fever convalescent pigs inhibited infection by homologous african swine fever virus. the infection-inhibition capacity did not correspond with the virus-neutralizing capacity. the serum did not prevent infection by heterologous virulent viruses. sera from pigs challenge inoculated with the homologous virulent virus and later with a heterologous virulent virus inhibited the infection by different heterologous virulent viruses. these sera did not interfer ... | 1986 | 3729125 |
| neutralization of african swine fever virus by sera from african swine fever-resistant pigs. | sera from african swine fever-resistant pigs with infection-inhibitory activity decreased virus replication in infected porcine buffy coat cultures. this same effect was observed even after virus was adsorbed. the infection-inhibition was not reversed by removing the immune serum from the assay cultures. reduction of african swine fever virus replication by immune sera was demonstrated by fluorescent focus assay on ms cell line cultures. virus-neutralization tests showed a persistent fraction of ... | 1986 | 3752695 |
| a novel selective broad-spectrum anti-dna virus agent. | a new compound has been found, (s)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine ((s)-hpmpa), that has potent and selective activity against a broad spectrum of dna viruses, including herpes simplex virus (types 1 and 2); varicella zoster virus; thymidine kinase-deficient (tk-) mutants of herpes simplex and varicella zoster virus; human cytomegalovirus; phocid, simian, suid, bovid and equid herpesviruses; african swine fever virus; vaccinia virus; and human adenoviruses. it is also active again ... | 1986 | 3762696 |
| african swine fever. i. morphological changes and virus replication in blood platelets of pigs infected with virulent haemadsorbing and non-haemadsorbing isolates. | replicating and mature viral particles were detected with the transmission electron microscope in blood platelets of pigs infected with virulent haemadsorbing and non-haemadsorbing african swine fever virus isolates. although platelet numbers decreased terminally in infected pigs, the most noticeable morphological damage to these cells apparent in the last 2 days of the disease included cytoplasmic swelling, vacuolation, fragmentation and loss of dense granules. | 1986 | 3763165 |
| hairpin loop structure of african swine fever virus dna. | the ends of african swine fever virus genome are formed by a 37 nucleotide-long hairpin loop composed, almost entirely, of incompletely paired a and t residues. the loops at each dna end were present in two equimolar forms that, when compared in opposite polarities, were inverted and complementary (flip-flop), as in the case of poxvirus dna. the hairpin loops of african swine fever and vaccinia virus dnas had no homology, but both dnas had a 16 nucleotide-long sequence, close to the hairpin loop ... | 1986 | 3763393 |
| single-stranded deoxyribonucleic acid nuclease induced by african swine fever virus and associated to the virion. | infection of vero cells with african swine fever (asf) virus resulted in a marked increase of dnase active on single-stranded dna (ss-dnase). no increase was observed for double-stranded dna-specific nuclease activity. in contrast to uninfected cell ss-dnase, which has a ph optimum at ph range 8.5-9, virus-induced ss-dnase is most active at ph 7. differences in sensitivity to several ions and other modifications of the reaction mixture and considerable difference in reaction kinetics suggest tha ... | 1986 | 3776099 |
| african swine fever virus-induced polypeptides in vero cells. | african swine fever virus induces in vero cells 81 acid and 14 basic polypeptides which account for most of the information content of the virus dna. the kinetics and the cytosine arabinoside sensitivity of the synthesis of the virus-induced polypeptides showed the existence of three classes of proteins, two early and one late. most of the early proteins were synthesized along the whole replication cycle, but the synthesis of some of the early proteins was switched-off after virus dna replicatio ... | 1986 | 3776350 |
| abortion in sows experimentally infected with african swine fever virus: pathogenesis studies. | thirteen sows that were 38 to 92 days pregnant were experimentally infected with an african swine fever (asf) virus strain of low virulence (dominican republic isolate). seven of 11 sows that were not killed had aborted. the pathogenesis of the abortions was studied, using virus isolation, tissue immunofluoresence, and histopathologic techniques. african swine fever virus was recovered from 179 of 1,329 (13.5%) fetal tissues tested. the 3 fetal tissues most frequently yielding virus were the fet ... | 1987 | 3826864 |
| an immunological approach to vaccines against african swine fever virus. | until recently there were no published reports of any immunological mechanism which could curtail the replication of african swine fever virus (asfv). we have now described three such mechanisms--complement dependent lysis, antibody dependent cellular cytotoxicity and cytotoxic t lymphocytes. this paper discusses the likely role which each might play during asfv infection and indicates where this research might help with a disease where no effective vaccine is available. | 1985 | 3873757 |
| monoclonal antibodies specific for african swine fever virus proteins. | we have obtained 60 stable hybridomas which produced immunoglobulins that recognized 12 proteins from african swine fever virus particles and african swine fever virus-infected cells. most of the monoclonal antibodies were specific for the three major structural proteins p150, p72, and p12. the specificity of some monoclonal antibodies for the structural proteins p150 and p37 and the nonstructural proteins p220 and p60 indicated that proteins p150 and p220 are antigenically related to proteins p ... | 1985 | 3882998 |
| comparative ultrastructure of iridoviridae. | | 1985 | 3893905 |
| african swine fever virus. | | 1985 | 3893908 |
| the epidemiology of african swine fever: the role of free-living hosts in africa. | the known distribution of african swine fever (asf) virus in africa is reviewed in relation to the distributions of its free-living hosts as are the infection rates of these species in different localities in southern africa. mechanisms by which asf virus is maintained in its sylvatic state and ways in which the infection may enter domestic pig populations are discussed. | 1985 | 3911134 |
| application of prpel2 plasmid to detect african swine fever virus by dna-dna hybridization. brief report. | a diagnostic assay has been developed to detect african swine fever virus in field samples. it is based on the use of 32p-dna from prpel2 plasmid as a hybridization probe. this plasmid contains essentially the h-clai dna fragment from the spain-70 strain of african swine fever virus. | 1986 | 3942504 |
| purification and properties of african swine fever virus. | we describe a method for african swine fever (asf) virus purification based on equilibrium centrifugation in percoll density gradients of extracellular virions produced in infected vero cells that yielded about 15 +/- 9% recovery of the starting infectious virus particles. the purified virus preparations were essentially free of a host membrane fraction (vesicles) that could not be separated from the virus by previously described purification methods. the purified virus sedimented as a single co ... | 1985 | 3989907 |
| effect of chloroquine on african swine fever virus infection. | when present during the whole infective cycle, the lysosomotropic drug, chloroquine, inhibited cytopathic changes and production of african swine fever virus (asfv) in vero cells. this inhibition decreased when the drug was added from 1 h to 4 h after infection. chloroquine had no effect on the virus nor on viral adsorption and internalization. electron microscopy showed that, in the presence of the drug, the virions were retained in large vacuoles having a lysosomal appearance. this inhibition ... | 1985 | 3998709 |
| the role of antibody in protection against african swine fever virus. | intraperitoneal immunization of pigs with anti-african swine fever virus (asfv) antibody protected them against the effects of challenge with asfv. this protection, which was exemplified by a reduction in pyrexia and viraemia plus an increased survival time, appeared to be mediated through the effects of complement-dependent antibody-mediated cytotoxicity (cdac) or antibody dependent cell mediated cytotoxicity (adcc). experiments suggested that the reduction in viraemia was associated with compl ... | 1985 | 4035978 |
| monoclonal antibodies against african swine fever viral antigens. | monoclonal antibodies specific for african swine fever (asf) viral proteins of 14, 32, 73, 174, and 240 kda were produced and characterized. immunoelectron microscopy detected the 73 kda but not the 14-, 32-, or 240-kda proteins at the surface of the virion. the 32-kda protein was detected by radioimmunoassay 2 hr after infection of porcine monocytes and vero cells, was detected in the seven widely divergent asfv isolates tested, and stained brilliantly virus-infected cells in indirect immunoflu ... | 1985 | 4060578 |
| mechanism of thrombocytopenia in african swine fever. | pigs were inoculated with an african swine fever (asf) isolate of moderate virulence, and the changes in the number of circulating blood platelets during infection were correlated with the appearance of antiviral antibody and fluctuations in total plasma hemolytic complement concentrations. thrombocytopenia was detected by postinoculation days (pid) 7 and 8, and antiviral antibody was detected by pid 7, using an indirect immunofluorescence technique. the total hemolytic complement concentration ... | 1985 | 4062007 |
| polypeptides and structure of african swine fever virus. | extracellular and intracellular african swine fever virus (asfv) was purified using a two-phase aqueous polymer system. both the structure of the virus and the polypeptides present during the purification procedure were studied. after peg/dextran phase separation and centrifugation through 20% (w/v) ficoll, 79% of input infectivity was recovered as semi-purified virus. the density of the virus after equilibrium centrifugation in sucrose was 1.19 g/ml. the envelope of the virion consisting of a u ... | 1985 | 4072397 |
| experimental transmission of african swine fever virus by ornithodoros savignyi (audouin). | the 'sand tampan', ornithodoros savignyi, is susceptible to oral infection with african swine fever (asf) virus in the laboratory. infected ticks can transmit the virus transstadially and are able to maintain it for at least 106 days. transmission of asf virus by infected ticks to healthy pigs was achieved on five separate occasions between 50 and 106 days after infection. pigs infected in this way developed typical acute african swine fever. the distribution of o savignyi in africa suggests tha ... | 1985 | 4081341 |
| chemical structure of african swine fever virus investigated by electron microscopy. | | 1967 | 4168517 |
| synthesis and cytopathogenesis of african swine fever virus in procine cell cultures. | | 1968 | 4171074 |
| immunofluorescence and inclusion bodies in circulating leukocytes of pigs infected with african swine fever virus. | | 1968 | 4180037 |
| hypergammaglobulinemia in swine infected with african swine fever virus. | | 1970 | 4192541 |
| immunofluorescence plaque assay for african swine fever virus. | suitably diluted cell culture adapted african swine fever virus preparations were inoculated on vero cell monolayers and grown on coverslips. gum tragacanth was used as an overlay. after three days incubation at 37 degrees c the infected cultures were fixed with acetone and stained with fluorescent antibody conjugate. fluorescing plaques consisted of 20-30 infected cells. three statistical criteria for a quantitatively reliable assay were met: the poisson distribution for plaque counts, linearit ... | 1974 | 4279763 |
| isolation of african swine fever virus from a giant forest hog. | | 1965 | 4283999 |
| african swine fever. ii. detection of the virus in swine tissues by means of the modified direct complement-fixation test. | the modified direct complement-fixation test, supplemented with unheated normal calf serum, was used to demonstrate antibodies in sera of swine immunized to african swine fever virus. these antibodies did not react in the ordinary direct non-supplemented complement-fixation test.african swine fever complement-fixing antigen in infected swine tissue is not denatured by extraction with fat solvents. consequently, good antigens devoid of non-specific reactivity were obtained by extraction with a mi ... | 1967 | 4291680 |
| antibody response to inactivated preparations of african swine fever virus in pigs. | | 1967 | 4291851 |
| segregation of a nonhemadsorbing african swine fever virus in tissue culture. | | 1968 | 4297717 |
| protein kinase activity in african swine fever virus. | | 1974 | 4365182 |
| sexual transmission of african swine fever virus in the tick, ornithodoros moubata porcinus, walton. | | 1974 | 4417657 |
| african swine fever virus. pathogenesis. | | 1974 | 4418259 |
| the localization of african swine fever virus in the tick ornithodoros moubata porcinus. | | 1972 | 4564455 |
| effects of some disinfectants on african swine fever virus. | ten commercially available disinfectants were tested at high ph in 2% sodium hydroxide and low ph in 2% acetic acid as inactivants for african swine fever (asf) in a protein-rich blood-spleen homogenate. as assayed in leukocyte cultures, sodium hydroxide and acetic acid, sodium meta silicate and roccal did not inactivate asf virus in 1 hr at 22 to 25 c. some viricidal activity as assayed in leukocyte cultures was found with weladol, triton x-100 amphyl, phisohex, sodium dodecyl sulfate, lph, env ... | 1973 | 4631432 |
| increased deoxyribonucleic acid polymerase activity in african swine fever virus-infected culture cells. brief report. | | 1972 | 4673394 |
| african swine fever virus. | | 1971 | 4950035 |
| separation of virus and soluble noninfectious antigens in african swine fever virus by isoelectric precipitation. | | 1965 | 4953582 |
| fluorescent antibody studies on african swine fever virus. | | 1966 | 4959954 |
| electron microscopy of the interaction of african swine fever virus with ferritin-conjugated antibody. | | 1967 | 4960597 |
| [position of african swine fever virus as a systematic virus]. | | 1968 | 4968760 |
| host specificity and serologic disparity of african swine fever virus and amphibian polyhedral cytoplasmic viruses. | | 1969 | 4973865 |
| ultrastructure of lymphocystis virus. | lymphocystis virus obtained from bluegills (lepomis macrochirus) was cultured in the permanent bluegill cell line bf-2 and examined by electron microscopy in ultrathin sections of cell cultures and in negative-contrast preparations from cells and from centrifuged culture medium. according to negative-contrast preparations, the icosahedral virions have an overall diameter close to but not exceeding 300 mmu. delicate filaments seem to issue from the vertices. in collapsed virions, an ordered array ... | 1968 | 4986903 |
| serological behaviour of isolated african swine fever virus. brief report. | | 1970 | 4992470 |
| inhibition by rifampin of african swine fever virus replication in tissue culture. | vaccinia virus and african swine fever virus are deoxyribonucleic acid viruses of cytoplasmic origin. the fact that rifampin inhibits the replication of the former virus led to an investigation of its effect on african swine fever virus. the virus used was cytopathogenic to a pk-15 cell line, hemadsorbing in pig leukocyte cultures and lethal to pigs. rifampin clearly inhibited the multiplication and cytopathogenicity of the virus in pk-15 cells. there was a 1- to 5-log reduction in virus titer d ... | 1971 | 5154875 |
| the growth of a virulent strain of african swine fever virus in domestic pigs. | | 1968 | 5239770 |
| the excretion of two virulent strains of african swine fever virus by domestic pigs. | daily observations were made on the excretion of african swine fever (asf) virus by pigs infected intranasally or by contact. two strains of virus having mean death times of approximately 3 and 6 days were used, the latter being recently isolated from a warthog.first excretion usually occurred by the nasopharyngeal route, as early as 1 or 2 days before the onset of fever in many cases. the titres of pharyngeal and nasal swabs rose rapidly to reach mean levels of about 10(4)-10(5) had 50 at 48-72 ... | 1970 | 5276336 |
| identification and localization of genetic material of african swine fever virus by autoradiography. | | 1967 | 5341983 |
| epizootiology of african swine fever virus in warthogs. | | 1969 | 5386390 |
| experimental infection of the argasid tick, ornithodoros moubata porcinus, with african swine fever virus. | | 1970 | 5475061 |
| altered thymidine kinase activity in culture cells inoculated with african swine fever virus. | | 1970 | 5528337 |
| transovarial infection with african swine fever virus in the argasid tick, ornithodoros moubata porcinus, walton. | | 1970 | 5532269 |
| the morphological characteristics of african swine fever virus and its resemblance to tipula iridescent virus. | | 1967 | 5628255 |
| the stability of african swine fever virus with particular reference to heat and ph inactivation. | | 1967 | 5628715 |
| plaque formation by african swine fever virus. | | 1968 | 5691283 |
| studies with hinde attenuated african swine fever virus. | | 1968 | 5693643 |
| a modified hemadsorption-inhibition test for african swine fever virus. | | 1968 | 5693874 |
| effect of hydroxyurea on the development of african swine fever virus. | | 1969 | 5776172 |
| african swine fever virus in ticks (ornithodoros moubata, murray) collected from animal burrows in tanzania. | | 1969 | 5813153 |
| the effect of stressor viruses on pigs inoculated with attenuated african swine fever virus. | | 1965 | 5892232 |
| extraction of infectious deoxyribonucleic acid from african swine fever virus. | | 1966 | 5928803 |
| electron microscopy of african swine fever virus hemadsorption. | | 1966 | 5949565 |
| swine diseases transmissible with artificial insemination. | the transport of fresh and frozen semen to be used for artificial insemination creates a mode of disease transmission between farms. normally, semen contains a number of nonpathogenic bacterial contaminants; however, excessive bacterial contamination can result in infertile matings. contamination with a known pathogen, eg, brucella suis, could initiate a serious outbreak of disease in a recipient herd. methods to minimize bacterial contamination of semen include sanitary collecting and processin ... | 1984 | 6090372 |
| antiviral action of 5-amino-2-(2-dimethyl-aminoethyl)benzo-[de]-isoquinolin-1,3-dion e. | a newly synthesized imide derivative of 3-nitro-1,8-naphthalic acid, 5-amino-2-(2-dimethylaminoethyl)benzo-[de]-isoquinolin-1,3-dione (designated m-fa-142), was tested on chick embryo cells against herpes simplex virus type 1 (hsv-1) and vaccinia virus (vv), and on vero cells against african swine fever virus (asfv). at a concentration of 4 micrograms/ml the drug inhibited vv replication by about one order of magnitude, and that of hsv-1 by about three orders of magnitude. a minor effect was sho ... | 1984 | 6091540 |
| cytotoxic lymphocytes induced by african swine fever infection. | the generation of lymphocytes cytotoxic to african swine fever virus infected testis cells during in vivo infection is described. peripheral blood lymphocytes from 16 pigs developed cytotoxicity seven to eight days after infection but the lysis was not restricted to autologous cells. | 1984 | 6095388 |
| [viral etiologies of aids: facts and hypotheses]. | all the epidemiological features suggest that the acquired immunodeficiency syndrome (aids) is caused by a single transmissible agent and surely a virus. first, cytomegalovirus, epstein-barr virus and hepatitis b virus have been proposed as possible etiological agents of aids. a direct link between ubiquitous viruses and the occurrence of the disease has been discarded. at present time, etiological researches provide evidence that retroviruses are the best candidates for the etiology of aids. th ... | 1984 | 6095408 |
| could aids agent be a new variant of african swine fever virus? | | 1983 | 6132234 |
| african swine fever virus antibody not found in aids patients. | | 1983 | 6133121 |
| aids and african swine fever. | | 1983 | 6134121 |
| aids and african swine fever. | | 1983 | 6134949 |
| polyadenylation, methylation, and capping of the rna synthesized in vitro by african swine fever virus. | | 1981 | 6168100 |
| leukocyte-dependent platelet vasoactive amine release and immune complex deposition in african swine fever. | fifteen pigs were inoculated with african swine fever virus in a study of the pathogenesis of the disease. all pigs surviving the first two weeks developed high circulating antibody titers against african swine fever virus and persistent viremia. hemolytic complement levels declined to 50 to 70 hemolytic complement 50 (ch50) units/ml from mean preinoculation levels of 120 ch50 units/ml. immune deposits consisting of african swine fever antigen, host immunoglobulin g, and native c3 were found in ... | 1981 | 6170156 |
| new method of antibody detection by indirect immunoperoxidase plaque staining for serodiagnosis of african swine fever. | an indirect immunoperoxidase plaque-staining method was developed for detecting antibody to african swine fever virus infection. in both sensitivity and specificity, the test was comparable to indirect immunofluorescence. because it has all of the desirable features of the indirect immunofluorescence test and may also be readily used for testing large numbers of sera, the indirect immunoperoxidase plaque-staining method can be used as a single and final serodiagnostic test in a large-scale surve ... | 1982 | 6185528 |
| effect of african swine fever on lymphocyte mitogenesis. | the effect of african swine fever virus replication on t and b lymphocytes was studied by mitogen-driven assays. live attenuated isolates caused a marked suppressive effect which was dose- and time-dependent. this effect appeared to be mediated through a monokine. live virulent isolates enhanced lymphocyte mitogenesis in most cases, with increased [3h]-thymidine uptake by t cells and increased ig secretion by b cells. killed preparation had no effect. these results are discussed in the light of ... | 1982 | 6210625 |
| nucleoside triphosphate phosphohydrolase activities in african swine fever virus. | african swine fever virus contains nucleoside triphosphate phosphohydrolase activity which releases 32p phosphate from gamma-32p atp at a rate of about 1 mumol/h mg of virus protein. the hydrolase activity is slightly stimulated by adding nucleic acids to the reaction mixture and under conditions of rna synthesis. a study of the rate of atp hydrolysis at different concentrations of atp suggests the existence of two phosphohydrolase activities with apparent km values of about 0.04 and 1 mm. | 1981 | 6271106 |
| african swine fever virus dna: restriction endonuclease cleavage patterns of wild-type, vero cell-adapted and plaque-purified virus. | dna from african swine fever (asf) virus was isolated and was characterized by two restriction enzymes, smai and ecori. although both enzymes can distinguish vero cell-adapted asf isolates by characteristic restriction endonuclease cleavage patterns, all asf isolates examined exhibited a high degree of similarity, as measured by co-migration of most of the dna fragments. the molecular weight of asf dna, based on size estimates of dna fragments from cleavage patterns, ranged from 93 x 10(6) to 10 ... | 1982 | 6296285 |
| african swine fever virus. brief review. | | 1983 | 6307224 |
| molecular cloning of african swine fever virus dna. | african swine fever virus dna (about 170 kbp) was cleaved with the restriction endonuclease ecori and most of the resulting 31 fragments were cloned in either the phage vector lambda wes lambda b or the plasmid pbr325. three fragments were not cloned in those vectors, the largest fragment ecori-a (21.2 kbp) and the two crosslinked terminal fragments, ecori-k' and d'. endonuclease sali cut fragment ecori-a into three pieces which were cloned in plasmid pbr322. the two terminal ecori fragments wer ... | 1984 | 6324451 |
| restriction site map of african swine fever virus dna. | treatment of african swine fever virus dna (about 170 kbp) with the restriction endonucleases sali, ecori, kpni, pvui, and smai yielded 14, 31, 17, 13, and 11 fragments, respectively. the order of the restriction fragments produced by each nuclease was established by identifying the crosslinked ecori and sali terminal fragments and then finding overlapping fragments. the five restriction fragment maps were integrated into a single map by locating sali, kpni, pvui, and smai sites in cloned ecori ... | 1984 | 6324452 |
| terminal and internal inverted repetitions in african swine fever virus dna. | an electron microscopic analysis of the heteroduplexes formed by reannealing denatured terminal restriction fragments of african swine fever (asf) virus dna showed y-shaped molecules with a 2.1-kilobase-pair-long double-stranded tail and two single-stranded arms. this indicated that asf virus dna has terminal inverted repetitions with a length of 2.1 kbp. in addition, under less restrictive hybridization conditions, most of the heteroduplexes showed a 0.13 kbp-long internal double-stranded regio ... | 1984 | 6324453 |
| foreign animal disease agent survival in animal products: recent developments. | | 1984 | 6327587 |
| speculations on the viral etiology of acquired immune deficiency syndrome and kaposi's sarcoma. | the acquired immune deficiency syndrome (aids) appeared in the united states in late 1978 and has spread at an epidemic rate through the four major coastal cities of this country. the disease appears to show the same epidemiologic distribution as hepatitis b virus infection, and for this reason, most investigators feel that this new disease is caused by a blood-borne sexually transmitted virus. a number of viral agents have been suggested as the cause of aids, but to date, no virus has been cons ... | 1984 | 6330223 |
| extraction of viral dna from erythrocytes of swine with acute african swine fever. | the preparation of wild-type african swine fever (asf) virus dna from small amounts of viremic blood from acutely febrile pigs is outlined. the extracted dna is viral and not host-cell dna, because of specific homology with cell culture grown and purified asf virus and because no dna bands are obtained with an equal amount of nonviremic pig blood. thus, in the absence of suitable serologic methods for strain identification, it is now possible to catalogue wild-type isolates by characteristic dna ... | 1984 | 6331232 |
| porcine leukocyte cellular subsets sensitive to african swine fever virus in vitro. | african swine fever virus infected most, if not all, of the macrophages (monocytes) and ca. 4% of the polymorphonuclear leukocytes from porcine peripheral blood. b and t lymphocytes, either resting or stimulated with phytohemagglutinin, lipopolysaccharide, or pokeweed mitogen, were not susceptible to the virus. all of the mitogens used inhibited african swine fever multiplication in susceptible cells. the number of virus passages in vitro and the virulence degree of the virus did not affect the ... | 1984 | 6384555 |
| proteins specified by african swine fever virus. iv. glycoproteins and phosphoproteins. | african swine fever virus infected ms cells labeled with radioactive 14c-amino acids, 32pi or [3h]-glucosamine were examined by high resolution sodium dodecylsulfate polyacrylamide gel electrophoresis and showed 43 infected cell polypeptides. twenty-one of these proteins were present in the nuclear fraction of infected cells. at least 22 of the infected cell polypeptides induced antibodies during natural infections in swine. the pattern of infected cell polypeptides modified by incorporation of ... | 1983 | 6416226 |
| coagulation changes in african swine fever virus infection. | pigs were infected with highly virulent (tengani '62), with moderately virulent (dr '79) african swine fever (asf) virus, or with virulent hog cholera (hc) virus. changes in platelet counts, selected coagulation assays and concentrations of factor viii-related antigen (viiir:ag) were monitored. permeability of aortic endothelium was studied after the injection of evan's blue dye on various days after infection with dr '79 asf virus. virulent asf virus caused prolongation of the activated partial ... | 1984 | 6441489 |
| quantitative aspects of the transmission of african swine fever. | the contagiousness of pigs during different stages of infection with african swine fever virus was assessed by measuring the amount of virus excreted and the amounts of virus in the blood and other tissues, as well as determining the infectious dose of the virus by various routes. the virus was present in substantial amounts in secretions and excretions of acutely infected pigs for only 7 to 10 days after the onset of fever and was present in the greatest amount in the feces. virus persisted in ... | 1984 | 6476567 |
| investigation of porcine natural-killer cell activity with reference to african swine-fever virus infection. | the natural killing of the human myeloid leukaemia cell line by pig mononuclear cells was investigated in an 18 hr assay; the most active natural-killer (nk) effectors were those cells not adhering to nylon-wool columns or rosetting with sheep red blood cells. mononuclear cells cultured in the presence of african swine-fever virus maintained nk activity. pigs infected with african swine-fever virus exhibited a suppressed nk activity, possibly due to the sensitivity of nk cells to increased tempe ... | 1983 | 6575959 |
| considerations in searching for the cause of aids. | | 1984 | 6598303 |
| effector mechanisms in the pig. antibody-dependent cellular cytolysis of african swine fever virus infected cells. | antibody dependent cellular cytolysis (adcc) against african swine fever virus infected nucleated cells was investigated in a porcine system. of the peripheral blood components examined, only neutrophils acted as effectors. lymph node derived cells displayed no adcc activity. in vitro yield reduction assays suggested that neutrophil mediated adcc may play a role in recovery from african swine fever virus infection. | 1983 | 6622849 |
| effect of rifamycin derivatives and coumermycin a1 on in vitro rna synthesis by african swine fever virus. brief report. | several rifamycin derivatives inhibited the dna-dependent rna polymerase of african swine fever (asf) virus particles. the inhibition was similar to that found with vaccinia virus rna polymerase. coumermycin a1, an inhibitor of type ii dna topoisomerases, inhibited strongly rna synthesis in vitro by asf virus particles. this suggests that transcription of asf virus dna requires a dna topoisomerase. | 1983 | 6625887 |
| general morphology and capsid fine structure of african swine fever virus particles. | the structure of african swine fever virus particles has been examined by electron microscopy. the analysis of virions prepared by negative staining, thin sectioning, and freeze-drying and shadowing showed that the virus particle was composed of several concentric structures with an overall icosahedral shape. the inner region of the virus particles was a nucleoid that was surrounded by a membrane covered by the capsid. the capsid had side-to-side dimensions of 172 to 191 nm and was built up by c ... | 1984 | 6695498 |
| virulence in african swine fever: its measurement and implications. | a method of measuring and expressing the virulence of african swine fever virus in numerical terms was developed. seventeen viruses (13 hemadsorbing and 4 nonhemadsorbing) were tested and classified into 3 groups: highly infectious and highly virulent, highly infectious and moderately virulent, and slightly infectious and slightly virulent. this classification was based on the number of 50% hemadsorption unit (ha50) or tcid50 required to produce 1 ld50 for swine, the number of ha50 or tcid50 req ... | 1984 | 6711963 |
| clinical and immunologic responses of pigs to african swine fever virus isolated from the western hemisphere. | pigs in the united states were exposed to african swine fever (asf) virus isolated from pigs in brazil and the dominican republic. the former were examined for clinical response, lesions, viremia, and antibody response. sequential blood samples were tested for the presence of asf virus by the hemadsorption test (in swine buffy coat cell culture) and for antibody to asf virus by the enzyme-linked immunosorbent assay. the incubation period was 3 to 5 days; inoculated pigs had fever for 8 to 16 day ... | 1984 | 6731983 |
| characterization of african swine fever virus antigenic proteins by immunoprecipitation. | african swine fever virus is a large, complex virion in which numerous proteins have been identified by biochemical techniques. few of these proteins have been shown to react with antibodies from recovered swine, leading to speculation that the immunological unreactivity of some viral proteins might explain the inability of immune sera from surviving animals to neutralize the virus. we used immunoprecipitation of radiolabeled viral proteins to examine these sera in more detail. gradient sodium d ... | 1984 | 6732509 |
| proteins specified by african swine fever virus. ii. analysis of proteins in infected cells and antigenic properties. | infection of ms cells with african swine fever virus (asfv) produces inhibition of protein synthesis which is detectable from 4.5 hours after infection. at least 34 viral polypeptides have been indentified with molecular weights ranging between 9500 and 243,000 daltons. three of these proteins show affinity for the cell nucleus and nine are in both the nuclear and cytoplasmic fractions. ten early proteins were found, and most of the structural proteins were late proteins. most of the proteins ar ... | 1980 | 6776940 |
| interactions of porcine alveolar macrophages and bone marrow cells with african swine fever virus and virus-infected cells. | virus yields from porcine alveolar macrophages (am) infected with african swine fever virus (asfv) were greater and were achieved more rapidly, when inoculated at a high multiplicity of infection (moi) than at low moi. the difference was related to a lower percentage of cells becoming infected after low moi inoculation. the reduced yields after low moi were not caused by prolongation of the culture time, by bacterial endotoxins or by production of inhibitory substances by infected am. virus-infe ... | 1983 | 6868333 |
| lymphocyte function and cell-mediated immunity in pigs with experimentally induced african swine fever. | twenty-five pigs inoculated with african swine fever virus were studied for the development of changes in lymphocyte numbers and function. the results indicated that lymphopenia and decreased percentage of circulating t-lymphocytes occurred as early as 7 days after the pigs were inoculated. these were accompanied by depressed lymphocyte function, as measured by mitogen- or antigen-induced blastogenesis. there were proportionately greater decreases in t-lymphocyte numbers and function than were f ... | 1981 | 6975049 |