| congenital infections with nonarbo togaviruses. | the present review deals with the similarities and differences of selected aspects of prenatal pestivirus infections of domestic animals and congenital rubella of man. hog cholera virus, bovine virus diarrhoea virus and border disease virus are antigenically closely related, but unrelated to rubella virus. the nonarbo togaviruses are capable of producing congenital infections resulting in a wide spectrum of abnormalities. the infected foetus can die in utero, in the neonatal period, or it may be ... | 1983 | 6314636 |
| 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 |
| properties of hog cholera viruses recently isolated in japan. | hog cholera (hc) viruses newly isolated in japan in 1980 and 1981 were examined for pathogenicity and serological properties by the neutralization test with antisera against bovine viral diarrhea-mucosal disease (bvd . md) and hc viruses. five of 23 isolates examined were neutralized poorly by bvd . md antibody, but well by hc antibody. on the contrary, 15 isolates were neutralized readily and two isolates moderately by bvd . md antibody. the other one reacted poorly with either hc or bvd . md a ... | 1983 | 6330573 |
| [enhancement of the immune response by aspecific action of vaccine additives in the aerogenic immunization of swine against swine plague]. | | 1983 | 6362602 |
| the neutralizing peroxidase-linked assay for detection of antibody against swine fever virus. | the neutralizing peroxidase-linked antibody ( npla ) assay was standardized and compared with the micro-plaque reduction test (prt) on series of sera from pigs infected with different strains of swine fever virus (sfv) and bovine virus diarrhoea virus (bvdv), swine fever reference sera and field sera. the npla system was found to be as sensitive as the prt, it detected sfv antibody in 17 out of 18 pigs 3 weeks after intranasal exposure and differentiated between antibody against sfv and bvdv. wi ... | 1984 | 6375112 |
| 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 |
| persistent hog cholera infection detected during virulence typing of 135 field isolates. | during the hog cholera (hc) eradication program in the united states, 135 field isolates were characterized by inoculation into specific-pathogen-free pigs. this gave origin to the classification of 61 (45%) as high virulent, 37 (27%) as low virulent, 29 (22%) as avirulent or immunizing, and 8 (6%) as capable of causing persistent infection. the persistent infections caused by the eight isolates were of long durtion, lasting in one instance to 152 days. the persistently infected pigs remained re ... | 1980 | 6449165 |
| 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 |
| detection of antibodies against swine fever virus by enzyme-linked immunosorbent assay (elisa). | | 1984 | 6524576 |
| [hyperlipidemia in swine immunized with lapinized vaccine and live swine plague virus]. | the purpose of the studies was to show the relationships between secondary hyperlipaemia and post-vaccination nephritis induced by lapinized vaccine with additional infection with the living virus of pig plague and the virus itself. ct, cf, lt, ffa and lp fractions were studied in the serum of blood taken from the vena cava cranialis from piglets weighing 30 - 40 kg, of the large white breed. in the animals of group 1, in the initial series a, series b - immunized with lapinized vaccine, series ... | 1984 | 6537493 |
| 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 |
| 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 |
| swine fever. immunisation of piglets. | vaccination against swine fever using the cl chinese strain can be done in 7-day-old piglets if they are born of non-immune sows. the simultaneous weaning and vaccination emphasises the safety of this strain. the excellent immunity observed confirms the immunocompetence of 7-day-old piglets. in piglets born of immune sows and also weaned at 7 days, passive protection can extend beyond the age of 2 months if the sow is vaccinated several months prior to gestation. the immune level of the piglets ... | 1983 | 6671375 |
| replication of hog cholera virus in porcine alveolar macrophage cultures. | eight hog cholera viral strains were tested for virulence for pigs and ability to replicate in porcine alveolar macrophage cultures. of them, five were virulent and replicated well in the macrophage culture. the other three were avirulent and grew less remarkably in this culture than them. it was suggested that the ability of the hog cholera viral strains to replicate in porcine macrophages might be correlated with their virulence. | 1983 | 6677832 |
| pathophysiology of gravidity. | regulating processes during embryonal and fetal growth are discussed (genes, hormones). due to viral infections there can be disorder of fetal life (resorption, mumification, abortion and malformations). mucosal disease is hold up as an example to describe that it depends on the moment of infection, on the development of immunologic competence and on the qualities of the virus, what happens after infection. the development of immunologic competence is considered carefully. an infection with muco ... | 1983 | 6683837 |
| 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 |
| [control of european (classical) hog cholera]. | | 1980 | 6758195 |
| [african swine plague in brazil: 3 years of laboratory study]. | | 1982 | 6765357 |
| 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 |
| effect of a hog cholera vaccine strain on the bactericidal activity of porcine alveolar macrophages. | | 1980 | 6794120 |
| [effect of specific vaccinal antigens and preparations on general resistance in growing experimental and domestic animals]. | studied was the effect of some viral and bacterial antigens as well as of a preparation obtained by filatov's method (modified by the author) on the general resistance in growing laboratory and domestic animals. it was found that in infantile albino mice the best protection against challenge with escherichia coli and pasteurella avicida was provided through the treatment with a biostimulator and a killed culture of a strongly proteolytic, unidentified strain of the 't3' bacterium. the vaccines a ... | 1982 | 6820584 |
| congenital tremor type ai: light and electron microscopical observations on the spinal cords of affected piglets. | the histology and ultrastructure of the spinal white matter from the dorsolateral funiculus of the third cervical segment was studied in normal control pigs and pigs whose dams were inoculated with the weybridge congenital tremor strain of swine fever virus in early pregnancy. only inoculated sows produced abnormal piglets. these showed congenital tremors and ataxia. the severity of clinical signs was related to the degree of spinal myelin deficiency. morphologically this was quantified by deter ... | 1983 | 6841693 |
| effect of infections with swine fever virus on immune functions. ii. lymphocyte response to mitogens and enumeration of lymphocyte subpopulations. | peripheral blood and spleen lymphocytes from pigs infected with a low-virulent strain of swine fever virus (sfv) were transiently hyporesponsive to the mitogenic action of pha, pwm and con a. the mitogenic reactivity of lymphocytes from lymph nodes from such pigs appeared to be enhanced rather than depressed at that time. in addition, hyper-responsiveness of peripheral blood lymphocytes (pbl) to these mitogens occurred in some pigs. pbl from pigs lethally infected with virulent sfv showed a pers ... | 1983 | 6845636 |
| effect of infections with swine fever virus on immune functions. iii. antibody response to lipopolysaccharide and sheep red blood cells. | in order to determine the effect of infections with low-virulent swine fever virus (sfv) on antibody responses, pigs were administered lipopolysaccharide (lps) or sheep red blood cells (srbc), 2 days after infection. infected pigs showed an enhanced primary response to lps late during infection. the secondary response to lps seemed to be unaffected. both the primary and secondary antibody response to srbc appeared to be enhanced rather than depressed in infected pigs. these in vivo findings sugg ... | 1983 | 6845637 |
| 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 |
| [african swine plague: study of viral resistance to the action of crystal violet]. | | 1982 | 6985409 |
| [ultramicroscopic observations of african swine plague virus in swine erythrocytes]. | | 1982 | 6985411 |
| replication of african swine fever virus in cell cultures. | infection-specific, nonstructural, african swine fever virus antigens, as visualized by the immunofluorescence technique, appeared as fine stipplings, evenly distributed in the cytoplasm and nucleus of vero cells and in monocytes by postinoculation hour (pih) 3. cytoplasmic inclusion bodies (ib) appeared at pih 4 and continued to increase in size up to pih 8. the viral dna was solely synthesized within the ib of infected monocytes, as evidenced by an autoradiographic chase experiment; maximum sy ... | 1980 | 7004279 |
| field evaluation of enzyme-linked immunosorbent assay for detection of antibody to african swine fever virus. | the enzyme-linked immunosorbent assay (elisa) for detection of antibodies to african swine fever virus was evaluated under field conditions in the dominican republic. a total of 3,402 swine serums were tested by elisa. all elisa-positive serums (n = 224) and 426 of 2,760 elisa-negative serums were retested by indirect immunofluorescence (iif). there were no antibodies to asf virus detected by iif in elisa-negative serums. by iif, antibodies were detected in only a small portion of the elisa-posi ... | 1981 | 7027849 |
| end-point dilution-fluorescent antibody technique for cloning hog cholera virus. | hog cholera virus was cloned by incubating selected pretitrated dilutions of the virus on pk-15 cell cultures for 2 hours. after a thorough washing, the coverslip cell cultures were overlaid with medium containing 0.1% hog cholera immune serum to prevent secondary foci. forty-eight hours later, the cultures were vigorously washed and maintenance medium containing 5% bovine fetal serum was added. when examined by the fluorescent antibody technique 18 hours later, single plaques were observed in s ... | 1982 | 7041710 |
| inactivation of african swine fever virus in tissues by gamma radiation. | | 1982 | 7046538 |
| complement-mediated lysis of african swine fever virus-infected cells. | using an homologous pig system, th lysis of african swine fever virus-infected cells by antibody and complement was investigated. the optimal conditions necessary for lysis are described, and it was found that the system was unique amongst reported virus infections in that infected cells were lysed by the classical complement pathway and not the alternative pathway. development of antibody capable of initiating complement-mediated lysis was relatively late in the infected pig, although functiona ... | 1982 | 7076281 |
| production and titration of african swine fever virus in porcine alveolar macrophages. | the broncho-alveolar lavage of a pig (20-40 kg) contains about 1.6 x 10(9) alveolar cells, half of which were macrophages. the number of cells in the lavage of bacille calmette guerin (bcg)-treated pigs increased about 4-fold. both african swine fever virus-infected porcine alveolar macrophages and blood monocytes produced about 1000 hemadsorption units/cell, a value 10-fold larger than that obtained in virus-infected vero cells. porcine alveolar cells could be stored frozen and, after thawing, ... | 1982 | 7085838 |
| [relevance of particle size for aerogenic immunization]. | | 1982 | 7138219 |
| [onset and persistence of immunity to swine fever following aerogenic immunization]. | | 1982 | 7138220 |
| in vivo labelling of viral proteins with 75selenomethionine. | a method is described for in vivo labelling of viral proteins with a gamma ray emitting radionuclide. the amino acid methionine labelled with 75se instead of 35s will be accepted by cells in culture for protein synthesis. a high specific labelling of viral proteins is achieved which allows rapid detection of virus or viral proteins in gradient centrifugation and page as well as further biochemical or serological analysis of the proteins. as an example hog cholera virus (family togaviridae) was l ... | 1982 | 7153307 |
| micro method for performing titration and neutralization test of hog cholera virus using established porcine kidney cell strain. | hog cholera (hc) virus and antibody against it were estimated by the end method with microplates and cpk porcine kidney cell strain. to establish the technique of this method, studies were made on such basic conditions of the method as the type of strain of newcastle disease virus (ndv), the time of challenge with this virus, and the concentration of serum in culture fluid. there was little difference in the infective titer of hc virus estimated between the end method performed by the establishe ... | 1981 | 7200574 |
| western hemisphere isolates of african swine fever virus: asymptomatic carriers and resistance to challenge inoculation. | convalescent clinically normal pigs were tested for the persistence of african swine fever (asf) infection. one group of pigs was examined 135 days after inoculation with a brazilian isolate and a 2nd group was examined 110 days after inoculation with a dominican republic isolate. susceptible pigs exposed by contact to these groups remained clinically normal. these contact pigs plus 2 more pigs added to each group developed asf after being fed and inoculated with tissues collected from recovered ... | 1980 | 7212418 |
| sedimentation coefficient of african swine fever virus. | the sedimentation coefficient of the infective unit of african swine fever in tissue culture harvest fluids was measured in a preparative ultracentrifuge. the boundary locator method used also permitted making an estimate of heterogeneity. the sedimentation coefficient ranged from 3,000 to 8,000 svedberg units, representing many classes of infective particles. electron microscopy on culture fluids from infected cells showed many kinds of virus-containing units. sucrose-cscl gradient centrifugati ... | 1980 | 7212420 |
| atypical hog cholera infection: viral isolation and clinical study of in utero transmission. | sows in different stages of pregnancy were inoculated with a low-virulence hog cholera strain. clinical signs of disease were not observed in the sows during pregnancy, but most of their pigs were splaylegged and had nervous disorders; perinatal mortality was high. a few pigs from sows that were inoculated during the 1st trimester of pregnancy survived and remained inapparent carriers of virus, without developing antibodies. seemingly, these pigs were immunotolerant. virus was transmitted from i ... | 1980 | 7212435 |
| experimental transplacental transmission of hog cholera virus in pigs. iii. histopathological findings in the fetus. | | 1980 | 7223180 |
| congenital tremor in pigs farrowed from sows given hog cholera virus during pregnancy. | at different stages of gestation, 3 groups of pregnant sows were inoculated with a strain of hog cholera virus (hcv). after the infection, clinical signs of hog cholera were not observed in the sows. pigs from the sows infected on day 22 or 43 of gestation showed varying degrees of muscular tremor, ataxia, splayleg, and suckling inability. of the pigs with tremor, 83% had cerebellar hypoplasia. surviving pigs demonstrated persistent viral infection and continued to shed hcv, but did not have ant ... | 1981 | 7224307 |
| [hog cholera diagnosis: an improved technique of seroneutralization based on use of a cytolytic virus strain in microplate (author's transl)]. | an improved technique for the detection of hog cholera virus (hcv) neutralizing antibodies is described, in which running of the test is greatly facilitated by use of a cytolytic strain of hcv. this strain was isolated from persistently infected ib-rs 2, and was shown to induce a distinct cytopathic effect in several pig kidney cell lines (laude, 1978). for the assay, serum samples at 1 : 10 are diluted serially twofold in disposable microplates, then 1 x 10(4) pfu of the virus-stock are added i ... | 1980 | 7259033 |
| possible factors influencing immunoglobulin a concentration in swine colostrum. | the immunoglobulin (ig) a concentration in swine colostrum was determined by the single radial immunodiffusion method, using 157 samples collected from the same number of farm-raised sows in the yamaguchi prefecture of japan during 1976 and 1977. the mean iga value was 12.26 +/- 3.30 mg/ml, and the maximum and minimum values were 28.14 mg/ml and 5.63 mg/ml, respectively. to determine factors influencing the iga concentration in swine colostrum, the following items were analyzed in the present st ... | 1981 | 7271021 |
| a simple procedure for the concentration and purification of hog cholera virus (hcv) using the lectin of ricinus communis. | | 1981 | 7295042 |
| [use of the hemadsorption method to demonstrate the african swine fever virus in angola]. | attempts were made to modify the hemadsorption method used in the demonstration of the african swine fever virus. use was made of fourteen strains of the virus with known hemadsorption properties and infectious titers, which were replicated in leukocyte cultures of swine blood, in three variants: (a) at direct infection of the cultures without changing the medium; (b) at infecting with changing the medium and adding erythrocytes to the new medium; and (c) infecting the cultures with changing the ... | 1981 | 7303482 |
| [one of aberrant organisms isolated from swine kidney culture cells (author's transl)]. | | 1980 | 7304099 |
| [study on hog cholera-sine erysipelas combined liver vaccine. i. experimental preparation of combined live vaccine (author's transl)]. | | 1980 | 7304106 |
| [study on hog cholera swine erysipelas combined live vaccine. -ii. indoor test of vaccination (author's transl)]. | | 1980 | 7304108 |
| induced african swine fever in feral pigs. | feral pigs trapped in florida were exposed by intranasal/oral inoculation or contact to african swine fever virus isolants from the iberian peninsula and the dominican republic. all exposed pigs became sick and died or were killed after becoming moribund. necropsy revealed lesions typical of african swine fever, but several pigs had marked hemorrhage surrounding the kidneys or rectum or in the gastric, hepatic, or ventral abdominal region that, in the field, might have suggested trauma or poison ... | 1981 | 7309606 |
| [study on hog cholera-swine erysipelas combined live vaccine. -iii. field trial of vaccination (author's transl)]. | | 1981 | 7324808 |
| experimental transplacental transmission of hog cholera virus in pigs. iv. virological and serological studies in newborn piglets. | | 1981 | 7336835 |
| experimental transplacental transmission of hog cholera virus in pigs. v. immunopathological findings in newborn pigs. | | 1981 | 7342578 |
| in vitro study of the cellular response of pigs vaccinated against classical swine fever. | | 1981 | 7342581 |
| african swine fever virus (malta/78) in pigs. | | 1981 | 7345110 |
| dna-dependent rna polymerase in african swine fever virus. | | 1980 | 7355576 |
| a microtechnique for the titration for african swine fever virus. | african swine fever virus isolates were titrated in swine monocyte cultures established in microtitre trays. although technically simpler and less laborious than conventional tube assays the microtitration assay was less sensitive, but for routine and comparative titrations offers distinct advantages. | 1980 | 7377975 |
| experimental transmission of african swine fever virus by ornithodoros coriaceus, an argasid tick indigenous to the united states. | three ticks, indigenous to the united states, were assessed for their ability to maintain and transmit african swine fever virus (asfv). amblyomma americanum and a cajennense adults and nymphs maintained virus for 4 to 7 days after engorging on infected swine blood; however, virus was not carried through the subsequent molt of nymphs and it was not transmitted vertically to the eggs and larvae of the infected females. on refeeding of the ticks, infection was not transmitted to healthy swine. orn ... | 1980 | 7406278 |
| lymphocyte responses to african swine fever virus infection. | the immunological response of pigs infected with african swine fever virus was related to both quantitative and qualitative changes in the lymphocyte population. the cytolytic effect of the virus on lymphocytes caused a proportionally greater drop in b cell than in t cell numbers. a blastogenic test was developed to measure the appearance of specifically sensitised lymphocytes in the circulation. these appeared about 10 days after infection in animals infected with attenuated virus; pigs infecte ... | 1980 | 7414064 |
| [epizootiological prerequisites and results of use of live vaccines]. | immunobiological action holds a firm position in veterinary legislation of the gdr with regard to the prevention and control of zoonoses, parasitoses, and other risk factors. here are some of the conditions which have to be satisfied for systematic and purpose-oriented application of live vaccines: (a) stringent procedures and rules for testing and acceptance of pharmaceutical preparations; (b) availability of scientifically founded concepts of application which have to be submitted for translat ... | 1980 | 7416892 |
| [requirements of rabbit-adapted swine fever vaccine]. | studies were conducted into the demands made on both harmlessness and effectiveness of suvac, a swine fever vaccine prepared from strain "c", a rabbit-adapted chinese virus strain. the following findings were obtained: --the vaccine strain was attenuated to an extent by which it could be used without serum. --the vaccine was harmless even with immunodepressor action. its immunogenicity was good, and live weight growth of the animals was not impaired. --the vaccine was harmless to the foetuses. - ... | 1980 | 7416897 |
| [use of lapinized "c" vaccine as aerosol in immunoprophylaxis against swine fever]. | lapinised vaccine, strain "c", was used on 3500 fattening pigs on two farms in experiments for aerogenic immunisation. two ordinary pigsties were modified for use as aerosol application chambers. a ussr-made disc-type aerosol generator, dag-2, was used for vaccine dispersion. piglets were allowed to be in contact with the aerosolic vaccine antigen for about 60 minutes. no deterioration in general health condition was observed, when longer contact periods were allowed. existing respiratory disord ... | 1980 | 7416898 |
| [immunologic abnormalities in pigs with hog cholera virus infection (author's transl)]. | the effects of an acute hog cholera virus (hcv) infection upon immune functions of experimentally infected pis were studied. leukopenia was found to occur in both vaccinated and non-vaccinated infected animals but without any decrease in lymphocyte proportion. lymphocytes from infected pigs had an altered response to phytohemagglutinin (pha) as judged by an in vitro tritiated thymidine uptake of pha-stimulated lymphocyte cultures. the beginning of a secondary humoral immune response to lysozyme ... | 1980 | 7436328 |
| proteins specified by african swine fever virus. i. analysis of viral structural proteins and antigenic properties. | at least 28 polypeptides have been identified in intracellular virus, with molecular weights ranging from 11,500 to 243,000 daltons. by treatment with nonidet p-40 and 2-mercaptoethanol it is possible to obtain subviral particles that have lost some proteins and have a density in cscl of 1.31 g/cm3 which is higher than that of the complete virus (1.23 g/cm3). after addition of nacl the virus loses its major protein vp73 which indicates that it is localized in the viral envelope. cores obtained a ... | 1980 | 7436740 |
| experimental infection of warthos (phacochoerus aethiopicus) with african swine fever virus. | although there were no obvious signs of illness following experimental infection of young warthog with african swine fever virus, the animals developed viraemias between 10(2,4) and 10(3,6) hd50/ml within the first week of infection, and virus concentrations in a number of lymphatic tissues attained high levels (greater than or equal to 10(6) hd50/g). unlike in blood, and to some extent in the spleen, virus titres in lymph nodes did not decline appreciable during the 33-day observation period, s ... | 1980 | 7454231 |
| experimental transplacental transmission of hog cholera virus in pigs. i. virological and serological studies. | | 1980 | 7467990 |
| experimental transplacental transmission of hog cholera virus in pigs. ii. immunopathological findings in the fetus. | | 1980 | 7467996 |
| experimental study of a mild virulence strain of hog cholera: individual variations and horizontal transmission. | | 1980 | 7468006 |
| synthesis of substituted 1-norbornylamines with antiviral activity. | the reaction of (+/-)-camphor (7) with triflic anhydride (tf2o) yields the bridgehead triflate 8. the nametkin rearrangement of 8 to 3 was realized by treatment with triflic acid (tfoh). the solvolysis of the bridgehead triflates 3 and 8 in acetonitrile affords the n-acetyl-1-norbornylamines 4 and 9. the pd(0)-catalyzed hydrogenation of 4 and 9 gives the amides 5 and 10. the corresponding 1-norbornylamines 2 and 13 and the n-ethyl derivatives 1, 6, 11, and 12 were obtained by basic hydrolysis or ... | 1995 | 7473574 |
| [localizing the major peptides of african swine fever virus and virus-associated enzymes in the virion structure]. | african swine fever virus polypeptides with molecular weight of 120, 78, 69, 59, 56, 45, 39, 28, 26, 24, 16, and 14 kd are the major proteins in the purified virions, as shown by electrophoresis and immunoblotting. a mixture of proteases and pancreatic lipase hydrolyzed the polypeptides of 120 and 78 kd in viral preparations at low concentrations of enzymes, polypeptides of 69, 56, 45, 39, 28, and 14 kd disappeared after treatment with this mixture at medium concentrations, and 26 kd polypeptide ... | 1995 | 7477038 |
| [apoptosis in the african swine fever virus-swine mononuclear phagocyte system]. | routine electronmicroscopic examination of interactions between african swine fever virus and mononuclear phagocytes showed signs of apoptosis as a morphological phenomenon and form of cellular death in an infected culture treated with defective interfering virus particles and in target cells under the effect of virus specific cytotoxic t-lymphocytes. the morphology of induced apoptosis in the aforesaid virus-cell system is illustrated and described in detail. | 1995 | 7477039 |
| [natural killers and cytotoxic lymphocytes in classical hog cholera]. | the formation of immune mechanisms directed at elimination of infected cells and including the activity of natural killers and cytotoxic lymphocytes was assessed in pigs infected with hog cholera virus. in acute disease natural killer activity in the blood is reduced, while in vaccinal process it is increased. vaccination in parallel with cyclophosphamide immunodepression lead to inhibition of natural killer activity. leukocytes and lymphocytes of immunized pigs can cause cytolysis of autologous ... | 1995 | 7483572 |
| african swine fever virus structural protein p72 contains a conformational neutralizing epitope. | we have previously described a monoclonal antibody (mab 135d4) to an unidentified 70- to 72-kda african swine fever virus (asfv) protein that exhibited high levels of neutralizing activity against various virulent asfv isolates. here, we identify the reactive asfv protein as the major virus structural protein p72. in vitro-translated products of the p72 protein gene were specifically immunoprecipitated by mab 135d4. immunoprecipitation of a nested set of truncated p72 in vitro translation produc ... | 1994 | 7514322 |
| antigenic structure of envelope glycoprotein e1 of hog cholera virus. | envelope glycoprotein e1 (gp51 to gp54) is the most antigenic protein of hog cholera virus or classical swine fever virus (csfv). four antigenic domains, a to d, have been mapped on e1 with a panel of monoclonal antibodies (mabs) raised against csfv strain brescia. the boundaries of these domains have been established by extensive studies on binding of mabs to transiently expressed deletion mutants of e1 (p. a. van rijn, e. j. de meijer, h. g. p. van gennip, and r. j. m. moormann, j. gen. virol. ... | 1994 | 7514680 |
| the influence of protease inhibitors of the organism, especially bovine aprotinin, on the production of virulent hog cholera virus in tissue cultures. | the influence of biological protease inhibitors, especially aprotinin, on the production of virulent hog cholera virus in cell cultures. production of number and size of fluorescent plaques after infection pk 15 cells with hc virus depended on properties of fetal calf sera added to the medium. by affinity chromatography on bovine alpha-chymotrypsin bound to cm-cellulose inhibitory proteins against chymotrypsin-like proteases could be eliminated from inhibiting sera. the fraction free from inhibi ... | 1994 | 7516855 |
| rapid characterization of new pestivirus strains by direct sequencing of pcr-amplified cdna from the 5' noncoding region. | reverse transcription coupled with the polymerase chain reaction (rt-pcr) was used for the rapid laboratory diagnosis of pestivirus infections. a direct dna sequencing method was developed for the analysis of the amplified cdna from the 5' noncoding region of the viral genome. 70 pestivirus strains were compared in this study. sequence analysis allowed the characterization of each isolate as either classical swine fever virus (csfv), bovine viral diarrhea virus, or border disease virus, respecti ... | 1994 | 7529990 |
| uses of flow cytometry in virology. | this article reviews some of the published applications of flow cytometry for in vitro and in vivo detection and enumeration of virus-infected cells. sample preparation, fixation, and permeabilization techniques for a number of virus-cell systems are evaluated. the use of flow cytometry for multiparameter analysis of virus-cell interactions for simian virus 40, herpes simplex viruses, human cytomegalovirus, and human immunodeficiency virus and its use for determining the effect of antiviral comp ... | 1994 | 7530594 |
| partial sequencing of hog cholera virus alfort strain genome and its comparison with other pestivirus strains. | after molecular rna cloning of the alfort strain (alfort/lcrv) of hog cholera virus (hcv), the nucleotide sequence of about 70% of the total genome was determined. this sequence was compared with homologous parts of previously published pestivirus genomes. the average homology with another clone of the alfort strain (alfort/frc) was found to be lower (86.1%) than with brescia strain of hcv (94.3%), while, compared with nadl, osloss and sd-1 (3 different strains of bovine viral diarrhea virus, bv ... | 1995 | 7550401 |
| pestivirus diversity. | | 1995 | 7560298 |
| pathological changes in the renal interstitial capillaries of pigs inoculated with two different strains of african swine fever virus. | african swine fever is a viral disease of pigs characterized predominantly by haemorrhagic lesions. this paper reports the lesions observed in the renal interstitial capillaries of pigs inoculated with african swine fever virus strains of differing virulence: the malawi'83 strain (haemadsorbent and highly virulent) and the dominican republic'78 strain (haemadsorbent and moderately virulent). in pigs infected with the malawi'83 strain, petechial haemorrhages and microhaemorrhages were observed 5 ... | 1995 | 7560303 |
| experimental african swine fever: apoptosis of lymphocytes and virus replication in other cells. | in order to determine the cause of cellular death of lymphocytes in pigs with acute african swine fever and the relationships between african swine fever virus (asfv) and interstitial cells, ten pigs were inoculated with a highly virulent strain of asfv (malawi '83) and samples taken for ultrastructural study of hepatic and renal interstitial tissues. we demonstrated death by apoptosis of lymphocytes and virus replication in fibroblasts, smooth muscle cells and endothelial cells in the interstit ... | 1995 | 7561784 |
| inactivation of viruses in liquid manure. | the stability of some viruses and methods of virus inactivation in liquid manure are reviewed. the authors discuss experimental data on the stability of foot and mouth disease virus, classical swine fever virus, aujeszky's disease virus, african swine fever virus, swine influenza virus, porcine paramyxovirus, bovine virus diarrhoea virus and transmissible gastroenteritis of pigs virus. recommendations and practical advice are given for the choice and application of chemical disinfectants for slu ... | 1995 | 7579641 |
| inhibition of il-2r and sla class ii expression on stimulated lymphocytes by a suppressor activity found in homogenates of african swine fever virus infected cultures. | virus free supernatants (vfs) obtained by ultracentrifugation of homogenates of african swine fever (asf) virus infected cultures inhibited the proliferative response and the expression in peripheral blood mononuclear cells of two activation molecules, the il-2 receptor (il-2r) and the swine mhc class ii antigens (sla ii), induced by several stimuli (lectins, pma plus the calcium ionophore a23187 or specific antigen). this inhibition was time dependent: no effect was seen on il-2r expression whe ... | 1995 | 7611879 |
| vectors for the genetic manipulation of african swine fever virus. | plasmid vectors designed to facilitate the genetic manipulation of african swine fever virus (asfv) are described. our results demonstrate that the beta-glucuronidase enzyme (gus) can be used to follow gene expression in asfv-infected cells. infectious plaques formed by asfv expressing gus are visually detectable, thus providing a simple and highly sensitive method for the selection of asfv recombinants. these and previous results have allowed us to construct two chimeric gene cassettes that con ... | 1995 | 7612241 |
| production and purification of recombinant african swine fever virus attachment protein p12. | the conditions for cultivation of spodoptera frugiperda (sf9) insect cells for production of recombinant baculoviruses have been studied, to scale-up and improve the efficiency of the process for production of the african swine fever virus attachment protein p12 in the baculovirus expression system. it was shown that the total virus and recombinant protein production in insect cells infected with the acp12 recombinant baculovirus were slightly dependent on cell density, but largely dependent on ... | 1995 | 7612242 |
| isolation and characterization of tk-deficient mutants of african swine fever virus. | african swine fever virus induces the synthesis of thymidine kinase (tk) in bhk tk-negative cells as an immediate early protein. the tk gene is not essential for growth of asfv in cell culture and a stable viral strain deficient in tk has been isolated (e70ntkp). the genetic lesion of this asfv tk- strain was identified by tk gene nucleotide sequencing, showing a nucleotide deletion leading to a -1 frameshift and a nonsense codon residue downstream of the deletion. the availability of this viabl ... | 1995 | 7625127 |
| comparison of the entire nucleotide and deduced amino acid sequences of the attenuated hog cholera vaccine strain gpe- and the wild-type parental strain ald. | we have determined the complete nucleotide sequences of a live attenuated hog cholera virus (hcv) and its progenitor strain. the viral rna of each strain consisted of 12,298 nucleotides including untranslated regions of 373 and 228 bases at the 5' and 3' end, respectively. there was a single large open reading frame spanning 11,697 nucleotides which could encode a large protein of 3,899 amino acids with a calculated molecular weight of 438-kda. we have found 225 nucleotide difference between the ... | 1995 | 7661692 |
| classical swine fever virus: independent induction of protective immunity by two structural glycoproteins. | to study which proteins of classical swine fever virus (csfv) are able to confer protective immunity in swine, n-terminal autoprotease, viral core protein, and the three structural glycoproteins were expressed via vaccinia virus recombinants (vvr). csfv proteins synthesized in cells infected with vvr showed migration characteristics on sodium dodecyl sulfate gels identical to those of their respective csfv counterparts. apparently authentic dimerization of the recombinant glycoproteins was obser ... | 1995 | 7666549 |
| localization of the african swine fever virus attachment protein p12 in the virus particle by immunoelectron microscopy. | the african swine fever virus attachment protein p12 was localized in the virion by immunoelectron microscopy. purified virus particles were incubated, before or after different treatments, with p12-specific monoclonal antibody 24bb7 and labeled with protein a-colloidal gold. untreated virus particles showed labeling only in lateral protrusions that followed the external virus envelope. mild treatment of african swine fever virions with the nonionic detergent octyl-glucoside or with ethanol onto ... | 1993 | 7679861 |
| reverse interference method for measurement of hog cholera virus (hcv) and anti-hcv antibody. | a new procedure was developed for the assay of the hog cholera virus (hcv) and anti-hcv antibody. initially, the suppression effect of hcv on interferon (ifn) by hcv production was confirmed. swine kidney cell cultures preinfected with hcv produced no ifn, even following the addition of ifn inducers. however the sensitivity of the cell to ifn was not influenced by the infection with this virus. based on these results, a new method, named reverse interference method, was established. in this meth ... | 1993 | 7685639 |
| characterization of structural and non-structural proteins of hog cholera virus by means of monoclonal antibodies. | a panel of 15 monoclonal antibodies, produced against the hog cholera virus, were characterized by radioimmunoprecipitation assays. using this panel, we were able to identify 4 sets of monoclonal antibodies precipitating each a different viral protein with relative molecular weight of 40, 46, 120 kda, respectively, and a protein complex containing 15, 16, 27, and 55 kda polypeptides which were further characterized. one monoclonal antibody recognized an antigenic determinant at the c-terminal cl ... | 1993 | 7688508 |