Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| establishment of b-lymphoblastoid cell lines from marek's disease virus-induced tumors in turkeys. | four lymphoblastoid cell lines were established from tumours of turkeys inoculated with high doses of the ga strain of marek's disease virus (mdv). unlike other md lymphoblastoid cell lines of chicken origin, these mdv transformed turkey line appear to be b lymphocytes and produce immunoglobulin. growth characteristics of these cell lines are slightly different; however, they all produce low levels of mdv-specific antigen and carry the complete genome of the virus as determined by virus rescue i ... | 1982 | 6277804 |
| the mechanism of genetic resistance to marek's disease in chickens. | genetic resistance to marek's disease in rpl line-6 chickens is expressed not only at the level of host immunological responses against virus an tumour antigens, but also at the level of target lymphoid cells for virus infection and transformation. the nature of the target cell involved was investigated. spleen cells from susceptible line-7 chickens adsorbed more marek's disease virus and turkey herpesvirus in vitro than line-6 spleen cells. in the case of marek's disease virus this was reflecte ... | 1982 | 6277808 |
| marek's disease tumors in chickens vaccinated with turkey herpesvirus vaccine. | this study evaluated the protective ability of cell-free and cell-associated turkey herpesvirus (hvt) vaccine against marek's disease (md). four variables were evaluated: cell-free versus cell-associated hvt; dose of hvt; time of exposure to md virus (mdv), and comparison of md challenge virus types. it was determined that gross lesions of md were more prevalent in chickens placed in an environment at one day of age with three-week-old chickens shedding the cpf-1 isolate of md, as in chickens gi ... | 1982 | 7166202 |
| protection by attenuated and polyvalent vaccines against highly virulent strains of marek's disease virus. | tests confirmed that turkey herpesvirus (hvt) vaccine protected chickens poorly against challenge with the highly virulent md5 strain of marek's disease (md) virus, especially in chickens with homologous hvt antibodies. the naturally avirulent sb-1 vaccine virus was likewise poorly protective against challenge with the md5 strain. homologous antibodies reduced the protective efficacy of both vaccines, but sb-1 was not affected by hvt antibodies. in order to provide better protection against stra ... | 1982 | 18770172 |
| characterisation of two highly oncogenic strains of marek's disease virus. | the rb-1b and ala-8 strains of marek's disease (md) virus, which were isolated from chickens with md and which had been vaccinated with the herpesvirus of turkeys (hvt), were evaluated for their oncogenic potential in genetically susceptible (p-line) and resistant (n-line, pdrc) chickens. rb-1b and ala-8 were both highly oncogenic, causing a high incidence of md in both susceptible and resistant birds. vaccination of p-line birds with sb-1 or hvt did not protect satisfactorily against rb-1b. how ... | 1982 | 18770225 |
| effects of avian viruses on cultured chicken bone-marrow-derived macrophages. | cultured chicken bone-marrow-derived macrophages have been assayed for their susceptibility to infection with various avian viruses. three criteria of infection were employed: (1) virus-induced alterations in cell morphology ; (2) presence of intracellular viral antigens detectable by immunofluorescence; (3) kinetics of virus release by infected macrophages. macrophages proved to be resistant to marek's disease virus (mdv), herpesvirus of turkeys (hvt-fc126), infectious bronchitis virus (ibv) an ... | 1983 | 18766776 |
| herpesvirus-induced atherosclerosis in chickens. | repeated experiments have established that infection with marek's disease herpesvirus (mdv) leads to atherosclerosis in specific pathogen free (spf) normocholesterolemic chickens. neither normocholesterolemic nor hypercholesterolemic uninfected spf chickens develop this disease. the mdv-induced arterial disease is remarkably similar to chronic human atherosclerosis. cholesterol and saturated cholesteryl esters accumulated in cultured arterial smooth muscle cells (smc) infected with mdv. similar ... | 1983 | 6840298 |
| monoclonal antibodies with specificity for three different serotypes of marek's disease viruses in chickens. | a total of 50 antibody-secreting hybridoma cells against marek's disease virus (mdv) and turkey herpesvirus (hvt) have been produced. eleven hybridomas were used for serotyping a panel of 15 pathogenic and nonpathogenic strains of mdv and hvt, representing three serotypes. the antibodies from the culture medium have fluorescence antibody (fa) titers of up to 100 and those from mouse ascitic fluid have titers ranging from 10(4) to 10(6). monoclonal antibody t81 is type-common, i.e., it reacts at ... | 1983 | 6184394 |
| most virus-specific polypeptides in cells productively infected with marek's disease virus or herpesvirus of turkeys possess cross-reactive determinants. | most virus-specific polypeptides in cells productively infected with marek's disease virus (mdv) or herpesvirus of turkeys (hvt) possess cross-reactive antigenic determinants, although the two viruses have very little dna homology. the cross-reactivity appeared to be more evident when [35s]methionine-labelled polypeptides were immunoprecipitated than when the [3h]glucosamine-labelled polypeptides were immunoprecipitated, suggesting that the glycoproteins of mdv and hvt may be less related in str ... | 1983 | 6187896 |
| vaccination against marek's disease and infectious bursal disease. i. development of a bivalent live vaccine by co-cultivating turkey herpesvirus and infectious bursal disease vaccine viruses in chicken embryo fibroblast monolayers. | vaccine viruses of marek's disease (md), the fc-126 strain of the herpesvirus of turkeys (hvt), and infectious bursal disease (ibd), the bursa-vac-m strain of ibd virus (ibdv), were propagated in the same chicken embryo fibroblast (cef) monolayers by superinfection. co-infection of the two viruses in the same cef culture or in a single cell can be demonstrated by staining with acridine orange and by electron microscopy.l this study was conducted with a superinfected live bivalent vaccine (hvt/ib ... | 1983 | 6322146 |
| in vivo and in vitro infections of chicken lymphocytes with marek's disease virus or herpesvirus of turkeys. | 1983 | 6323800 | |
| marek's disease herpesviruses. iv. molecular characterization of marek's disease herpesvirus a antigen. | marek's disease herpesvirus a antigen (mdhv-a) was identified as a 61,000- to 65,000-dalton glycoprotein by sodium dodecyl sulfate-polyacrylamide gel electrophoresis after immunoprecipitation from the culture medium of both [35s]methionine- and [14c]glucosamine-labeled infected cells by specific rabbit serum directed against mdhv-a. rigorous identification was accomplished by selective blocking of this specific immunoprecipitation of the glycoprotein with purified mdhv-a that was isolated at its ... | 1983 | 6300460 |
| characteristics of marek's disease viruses isolated from vaccinated commercial chicken flocks: association of viral pathotype with lymphoma frequency. | fifty-three marek's disease (md) virus (mdv) isolates were obtained from turkey-herpesvirus-vaccinated broiler or layer flocks with excessive md losses, from control field flocks without excessive md losses, and from laboratory collections. twelve isolates were typed as very virulent (vvmdvs) on the basis of excessive pathogenicity for vaccinated chickens, 31 were typed as virulent (vmdvs), and 10 were typed as nonpathogenic (npmdvs). the npmdvs could be distinguished from turkey herpesviruses b ... | 1983 | 6303287 |
| embryo vaccination against marek's disease with serotypes 1, 2 and 3 vaccines administered singly or in combination. | marek's disease virus (mdv) vaccines of serotypes 1 and 2 administered in 18-day-old embryonated eggs induced better protection against post-hatch challenge at 3 days with virulent mdv than vaccines given at hatch. embryonal vaccination with a polyvalent vaccine containing equal quantities of serotypes 1 and 2 of mdv and serotype 3 virus (turkey herpesvirus, hvt) was also significantly more effective than post-hatch vaccination. these and earlier results indicate that protective efficacy of sing ... | 1983 | 6307248 |
| simultaneous vaccination of one-day-old broiler chickens with tenosynovitis virus and turkey herpesvirus. | an attenuated tenosynovitis virus vaccine and turkey herpesvirus (hvt) vaccine mixed prior to vaccination were injected subcutaneously into one-day-old chicks. in laboratory and field trials there did not appear to be any interference, because chickens vaccinated with both vaccines were effectively immunized against challenge with virulent marek's disease virus or tenosynovitis virus when compared with unvaccinated chickens or chickens vaccinated with either hvt or tenosynovitis virus. the combi ... | 1983 | 6312445 |
| field trials with a bivalent vaccine (hvt and sb-1) against marek's disease. | white leghorn chickens on five farms were given a bivalent marek's disease (md) vaccine consisting of turkey herpesvirus (hvt) and sb-1 (a nononcogenic md virus); other chickens received only hvt. the farms had histories of "vaccination failures," presumably owing to an exceptionally virulent challenge md virus. the bivalent vaccine uniformly protected chickens better than hvt alone between 12 and 16-20 weeks of age, when serious md losses occurred. during that period, total mortality in groups ... | 1983 | 6314982 |
| restriction endonuclease analysis of marek's disease virus dna and homology between strains. | the restriction endonuclease patterns of viral dna obtained from serotypes 1 and 2 strains of marek's disease virus have been compared and homology between the strains examined by hybridization. the results have shown that hprs 16 (serotype 1) dna has a structure similar to its attenuated variant hprs 16/att except for a few fragments that are present only in the virulent strain. evidence was obtained which suggested that these restriction fragments contained repeat sequences and that insertion ... | 1983 | 6319562 |
| marek's disease virus and herpesvirus of turkeys: antigenic aspects. | 1983 | 6195671 | |
| antigenic relatedness of pigeon herpes encephalomyelitis virus to other avian herpesviruses. | pigeon herpes encephalomyelitis virus (phev) was compared with seven avian herpesviruses for antigenic relatedness using monospecific antisera and the indirect fluorescent-antibody (ifa), agar-gel-immunodiffusion, and serum-neutralization tests. no antigenic relationship was detected between phev and marek's disease virus, turkey herpesvirus, infectious laryngotracheitis virus, and duck enteritis virus. a common precipitating antigen was detected between the phev and pigeon herpesvirus (phv), ow ... | 1983 | 6196014 |
| comparative studies on antigens induced by turkey herpesvirus and marek's disease virus. i. agar gel precipitation and neutralization studies. | 1983 | 6196928 | |
| comparative studies on antigens induced by turkey herpesvirus and marek's disease virus. ii. immunofluorescent studies. | 1983 | 6197828 | |
| monoclonal antibodies reactive with the surface and secreted glycoproteins of marek's disease virus and herpesvirus of turkeys. | hybridomas were formed between mouse myeloma cells and spleen cells from mice immunized with marek's disease virus (mdv) or with herpesvirus of turkeys (hvt). three monoclonal antibodies were obtained, two (m26 and m34) from mdv clones and one (h9) from an hvt clone, all of which were specific for cross-reactive membrane antigen (ma) expressed on the surface of cells infected with mdv or hvt. all three antibodies also reacted with mdv- and hvt-specific glycoproteins in the molecular weight (mol. ... | 1983 | 6198439 |
| monoclonal antibody-mediated immunoprecipitation of proteins from cells infected with marek's disease virus or turkey herpesvirus. | the major immunogenic viral proteins of marek's disease virus (mdv) and turkey herpesvirus (hvt) share antigenic determinants. the polyacrylamide gel electrophoresis pattern of five viral polypeptides immunoprecipitated with homologous convalescent chicken plasma was identical with the pattern obtained after immunoprecipitation with heterologous convalescent chicken plasma. a panel of monoclonal antibodies was used to identify mdv and hvt polypeptides. sixteen monoclonal antibodies were positive ... | 1984 | 6205501 |
| studies on the serological cross-reaction between marek's disease virus and herpesvirus of turkeys using monoclonal antibodies to major virus-specific polypeptides. brief report. | a major virus-specific polypeptide antigenically cross-reactive between marek's disease virus (mdv) and herpesvirus of turkeys (hvt) was characterized by two monoclonal antibodies against mdv. the antigenic determinant recognized by one monoclonal antibody was present only in the mdv polypeptide but not in the hvt polypeptide, whereas the antigenic determinant recognized by the other antibody was present in both mdv and hvt polypeptides. peptide mapping showed the difference in the amino acid se ... | 1984 | 6206826 |
| evaluation of dna homology of marek's disease virus, herpesvirus of turkeys and epstein-barr virus under varied stringent hybridization conditions. | marek's disease virus (mdv) showed only 0.3-0.6% homology in dna sequence with herpesvirus of turkeys (hvt) at tm-24.4 degrees c in spite of its antigenic similarity to the latter. southern blot hybridization under stringent conditions showed that the homology between mdv and hvt is located in the restricted portion of these viral genomes. at tm-49.6 degrees c, which permits the detection of homology with one base mismatch in three between the mdv and hvt dnas, sequences with weak homology were ... | 1984 | 6086596 |
| comparative viral, immunologic, and pathologic responses of chickens inoculated with herpesvirus of turkeys as embryos or at hatch. | chickens were vaccinated with the herpesvirus of turkeys (hvt) at embryonation day 17 or 18 or at hatch and various responses of the 2 vaccinated groups were compared. in embryo-vaccinated chickens, hvt titers were high in the lungs before hvt could be isolated from other tissues. seemingly, embryos acquired infection via the respiratory tract. in hatch-vaccinated chickens, hvt was first isolated from spleen and then from other tissues. titers of recoverable hvt in tissues of embryo-vaccinated c ... | 1984 | 6089624 |
| vaccination against marek's disease and infectious bursal disease. ii. titration and in vivo efficacy of the coinfection-derived bivalent live vaccine for turkey herpesvirus and infectious bursal disease virus. | the bivalent hvt/ibdv live vaccine, developed by cocultivation of the turkey herpesvirus (hvt) and infectious bursal disease virus (ibdv) vaccine in cell cultures, was quantitated. the titer of each constituent virus could be successfully determined in vitro by pretreatment of the vaccine with anti-ibdv serum or chloroform (chcl3). studies in vivo further demonstrated that the anti-ibdv serum-treated hvt/ibdv vaccine lost its immunogenicity by failing to induce ibdv-neutralizing antibody or to p ... | 1984 | 6091083 |
| effect of infectious bursal disease virus on protection against marek's disease by turkey herpesvirus vaccine. | chickens inoculated at hatch with pathogenic infectious bursal disease virus (ibdv) and the turkey herpesvirus (hvt) vaccine were poorly protected against challenge at 1 week with virulent marek's disease virus (mdv). however, if vaccination with hvt preceded ibdv inoculation such as by embryonal vaccination with hvt and exposure to ibdv at hatch, or by vaccination at hatch and ibdv exposure 5 days or longer postvaccination, then the vaccinal efficacy of hvt was not influenced. further, the inhi ... | 1984 | 6091603 |
| processing of glycoprotein gb related to neutralization of marek's disease virus and herpesvirus of turkeys. | the glycoprotein gb related to neutralization of marek's disease virus (mdv) and herpesvirus of turkeys (hvt) is composed of several glycosylated polypeptides, which were immunoprecipitated with monoclonal antibodies and rabbit antiserum cross-reactive to mdv-gb and hvt-gb, and analyzed by sds-polyacrylamide gel electrophoresis. the present pulse-chase experiments showed that the precursor forms of mdv- and hvt-gb were glycoproteins with molecular weights of 110k to 115k (gp115/110) and 115k (gp ... | 1984 | 6094991 |
| latent herpesvirus infection of testes and spinal ganglia of turkeys with semen abnormalities. | the present study confirms that herpesviruses (lf) previously isolated from testes and buffy coat cells of male turkeys with semen abnormalities establish a latent infection in testicular cells. these experiments also present the first evidence that these herpesviruses are harbored latently in cells of spinal ganglia. one-week-old turkeys were inoculated with either the lf isolates or the prototype turkey herpesvirus fc 126; allowed to mature sexually through one breeding season and necropsied a ... | 1984 | 6095790 |
| cell-specific antiviral activity of 1-(2-fluoro-2-deoxy-beta-d-arabinofuranosyl)-5-iodocytosine (fiac) against marek's disease herpesvirus and turkey herpesvirus. | three new fluoroarabinosylpyrimidine nucleosides (fiac, fiau and fmau) were tested for in vitro activity against oncogenic and nononcogenic strains of marek's disease virus (mdv) and herpesvirus of turkeys (hvt). marek's disease is a herpesvirus-induced lymphoma in chickens. nononcogenic strains of mdv and hvt can protect against this disease. all viruses were inhibited by 1 microm of these drugs in chick kidney cell (ckc) cultures, but only fmau and fiau were active in chicken embryo fibroblast ... | 1984 | 6097179 |
| identification with monoclonal antibodies of glycoproteins of marek's disease virus and herpesvirus of turkeys related to virus neutralization. | by use of monoclonal antibodies cross-reactive with marek's disease virus and herpesvirus of turkeys, three glycoproteins (for marek's disease virus, gp115/110, gp63, and gp50; for herpesvirus of turkeys, gp115, gp62 and gp52) related to virus neutralization were identified. immunization of chickens or rabbits with these glycoproteins purified by affinity chromatography resulted in production of neutralizing antibodies. | 1984 | 6321752 |
| immunization against marek's disease transplantable cell lines. | continuous passage of mdcc-rp1, a highly tumorigenic marek's disease (md) lymphoblastoid cell line, in cell culture resulted in a gradual loss in ability of the cell line to cause progressive tumors in susceptible day-old chicks. inoculation of day-old chicks with high-cell-culture-passaged (187th to 417th) nontumorigenic mdcc-rp1 cells gave excellent protection against challenge at 8 days with low-passaged tumorigenic mdcc-rp1 cells but failed to protect against primary tumors caused by inocula ... | 1984 | 6326737 |
| field trials to test the efficacy of polyvalent marek's disease vaccines in broilers. | the efficacies of trivalent (md11/75c + sb-1 + hvt), bivalent (sb-1 + hvt), and turkey herpesvirus (hvt) vaccines against marek's disease (md) were compared in commercial broiler flocks in four trials involving 11 farm locations and 486,300 chickens. in all four trials, chickens receiving polyvalent vaccines had lower leukosis (md) condemnation rates than chickens vaccinated with hvt alone; when data were summarized for each vaccine type in each trial, condemnation rates for the bivalent- or tri ... | 1984 | 6326743 |
| extensive homology exists between marek disease herpesvirus and its vaccine virus, herpesvirus of turkeys. | marek disease is a lymphomatous disease of chickens caused by infection of a herpesvirus, marek disease virus (mdv). marek disease is the only neoplastic disease for which a successful vaccine has been developed. the vaccine virus, herpesvirus of turkeys (hvt), is non-oncogenic in chickens. despite the strong antigenic relationship between these viruses, previous studies showed that the two viral dnas share little or no homology. using less stringent hybridization conditions and methods that gre ... | 1984 | 6328512 |
| polyvalent marek's disease vaccines: safety, efficacy and protective synergism in chickens with maternal antibodies. | three marek's disease (md) vaccines were evaluated for safety and protective efficacy in chickens with maternal antibodies against serotype 1, 2 and 3 md viruses and in chickens with no maternal antibodies. the vaccines were: (1) md11/75c, an attenuated serotype 1 md virus, (2) a trivalent mixture of md virus strains md11/75c and sb-1, and turkey herpesvirus (hvt) strain fc 126, and (3) bivalent mixtures of these three viruses. these vaccines were compared with hvt or sb-1 vaccines in some trial ... | 1984 | 18766823 |
| the expression of marek's disease tumour-associated surface antigen in various avian species. | marek's disease tumour-associated surface antigen (matsa) was detected on lymphoid cells from chickens infected with marek's disease virus (mdv) or the herpesvirus of turkeys (hvt), from a chicken-quail hybrid infected with mdv, and from turkeys infected with the ga strain of mdv, but not on cells from turkeys infected with hvt or the hprs-16 strain of mdv or from mdv-infected japanese quails or bobwhite quails, despite the presence of lymphomas in some japanese quails. two complementary explana ... | 1984 | 18766850 |
| partial protection against marek's disease in chickens immunized with glycoproteins gb purified from turkey-herpesvirus-infected cells by affinity chromatography coupled with monoclonal antibodies. | glycoproteins gb of marek's disease virus (mdv) and herpesvirus of turkeys (hvt) related to virus neutralization were purified from hvt-infected cells by affinity chromatography. immunization of chickens with purified glycoproteins gb resulted in partial protection against md. neutralizing antibodies were detected in chickens immunized with hvt-gb. | 1985 | 3896223 |
| field trials to test the efficacy of polyvalent marek's disease vaccines in layer and broiler breeder chickens. | as a follow-up to earlier trials to evaluate the efficacy of polyvalent marek's disease (md) vaccines in broilers, four trials were conducted with layer or broiler breeder flocks. chickens caccinated with trivalent (md11/75c plus sb-1 plus hvt) and bivalent (sb-1 plus hvt) vaccines were compared with those vaccinated with turkey herpesvirus (hvt) alone. data from three of the four trials indicated polyvalent vaccines were more efficacious than hvt. however, critical interpretations were confound ... | 1985 | 3912753 |
| inhibition of turkey herpesvirus replication by anti-cellular serum. | quail embryo fibroblasts were used to investigate how rabbit and chicken antisera against chicken erythrocytes carrying different b alleles of the major histocompatibility antigens affect the neutralization of herpesvirus of turkeys (hvt). although the neutralizing activities of these antisera were rather low, the hvt propagated in chicken embryo fibroblasts (cef) from certain genotypic embryos was neutralized more by the antisera to the corresponding erythrocytes. after absorption of these anti ... | 1985 | 3985879 |
| altered cholesteryl ester cycle is associated with lipid accumulation in herpesvirus-infected arterial smooth muscle cells. | we describe herein the effects of marek's disease herpesvirus (mdv) on cholesterol and cholesteryl ester metabolism in cultured chicken arterial smooth muscle cells. infection of arterial smooth muscle cells from specific pathogen-free chickens with mdv, but not a virus control, herpesvirus of turkeys led to a 7-10-fold increase in the accumulation of free and esterified cholesterol and a 2-fold increase in phospholipids. the cellular lipid changes observed in the mdv-infected arterial smooth mu ... | 1985 | 3997816 |
| monoclonal antibodies against virus-specific antigens in culture cells infected with herpesvirus of turkeys. | 1985 | 4068446 | |
| map location of homologous regions between marek's disease virus and herpesvirus of turkey and the absence of detectable homology in the putative tumor-inducing gene. | the dna region having homology between marek's disease virus and herpesvirus of turkey was assigned to the restriction map of marek's disease virus by southern blot hybridization. under moderate conditions at the level of 15% mismatching, homology was found to be distributed throughout the marek's disease virus genome. the long inverted-repeat regions (trl and irl), which are considered to play a significant role in tumorigenicity, did not show any homology to herpesvirus of turkey dna. | 1985 | 2983105 |
| simultaneous application of live turkey herpesvirus and infectious bursal disease vaccines against marek's disease and infectious bursal disease. | the efficacy of cell-associated (ca) and cell-free (cf) infectious bursal disease (ibd) vaccines in maternal antibody (mab)-bearing broiler chickens was compared. compatibility and potency of a mixed vaccine combining live ca turkey herpesvirus (hvt) and ca ibd vaccine viruses were also tested against gross lesions induced by marek's disease (md) or ibd in specific-pathogen-free chickens. both ca and cf ibd vaccines provided significant protection against gross bursal lesions of ibd in the prese ... | 1985 | 2983300 |
| gel electrophoretic analysis of polypeptides from nucleocapsids of marek's disease virus strains and herpesvirus of turkey. | the polypeptides of nucleocapsids of marek's disease virus (mdv) strains with different biological properties and of antigenically related herpesvirus of turkey (hvt) strains were analysed by one- and two-dimensional (1d and 2d, respectively) gel electrophoresis. based on small differences in migration behaviour (size and charge) of a number of corresponding nucleocapsid polypeptides, the virus strains could be differentiated into three groups. the polypeptide pattern of group i, comprising the ... | 1985 | 2986577 |
| differences in the processing of secreted glycoprotein a induced by marek's disease virus and herpesvirus of turkeys. | the steps from the precursor to the processed forms of a secreted glycoprotein (ga) of marek's disease virus (mdv) and of herpesvirus of turkeys (hvt) were examined by two-dimensional gel electrophoresis of immunoprecipitates from the cell lysate and medium of infected cultures with monoclonal antibodies. differences between mdv- and hvt-ga were particularly observed in isoelectric points of the glycosylated or unglycosylated precursor forms. | 1985 | 2987399 |
| vaccination against marek's disease and infectious bursal disease iii. growth rate of both turkey herpesvirus and infectious bursal disease virus in coinfected cell cultures. | titers of the turkey herpesvirus (hvt) and infectious bursal disease virus (ibdv) in coinfected cell cultures, used to produce a live bivalent hvt/ibdv vaccine, were determined daily. based on the daily titers, cells harvested either 2 or 3 days after inoculating the second virus (ibdv) into hvt infected cell cultures yielded the maximum titers for both viruses. harvesting coinfected cell cultures on either day provided the most suitable source of the live hvt/ibdv vaccine against marek's diseas ... | 1985 | 2987896 |
| production of herpesvirus of turkeys in microcarrier culturing system--a new method for production of vaccine against marek's disease. | a microcarrier (mc) culturing system for production of a vaccine against marek's disease virus is presented. cytodex-3 beads (pharmacia) and de-53 microgranular (whatman) are the recommended microcarriers. primary cells from chick embryo as well as cells from a quail cell line (qt-6, established from a japanese quail) were found to be good hosts for growth of herpesvirus of turkeys (hvt). hvt, the vaccine strain against marek's disease, was successfully grown and harvested on the above mentioned ... | 1985 | 2995176 |
| herpesviruses provide helper functions for avian adeno-associated parvovirus. | the avian herpesviruses infectious laryngotracheitis virus (iltv) and herpesvirus of turkeys (hvt), as well as the mammalian herpesvirus pseudorabies virus (prv) were able to provide complete helper activity for the production of infectious avian adeno-associated virus (aaav) in chicken cells. the presence of aaav in the infected chicken cell reduced the multiplication of hvt. iltv or prv, however, were not affected if used as helper viruses. infectious aaav was determined by an indirect immunof ... | 1986 | 3003233 |
| chicken embryonal vaccination with avian infectious bronchitis virus. | a commercial infectious bronchitis virus (ibv) vaccine of the massachusetts 41 strain was injected in embryonating chicken eggs on embryonation day (ed) 18. the ibv vaccine was pathogenic for embryos, and it was passaged in chicken kidney tissue culture to reduce the pathogenicity. at the 40th tissue culture passage (p40-ibv), the virus became apathogenic for the embryos. maternal antibody-positive or -negative chicks hatching from eggs injected with p40-ibv developed antibody to ibv and were pr ... | 1986 | 3008613 |
| herpesvirus infection prevents activation of cytoplasmic cholesteryl esterase in arterial smooth muscle cells. | herpesvirus infection has been shown to alter the cholesteryl ester cycle in avian arterial smooth muscle cells, resulting in cytoplasmic cholesteryl ester accumulation (hajjar, d. p., falcone, d. j., fabricant, c. g., and fabricant, j. (1985) j. biol. chem. 260, 6124-6128). in this study, we attempted to define some of the regulatory mechanisms associated with the control of cytoplasmic cholesteryl esterase in marek's disease herpesvirus (mdv)-infected cells. we found that cholesteryl esterase ... | 1986 | 3011790 |
| a comparison of the biological properties of type 2 plaque-producing agent derived from the cal-1 strain of marek's disease virus with other related viruses. | the serological and biological properties of the type 2 plaque-producing agent (ppa) derived from the cal-1 strain of marek's disease virus (mdv) were compared with those of reference strains of the three serotypes of mdv and herpesvirus of turkeys (hvt) groups; namely jm, hprs-24 strains of mdv and the fc-126 strain of hvt for serotype 1, 2, and 3, respectively. by agar gel precipitation (agp), indirect fluorescent antibody and virus neutralization tests, type 2 ppa was related but not identica ... | 1986 | 3013131 |
| pathogenicity studies with plaque-purified preparations of marek's disease virus strain cvi-988. | the pathogenicity of marek's disease (md) strain cvi-988 vaccine, eight plaque-purified preparations originating from this strain, and the vaccine hvt fc126 (based on herpesvirus of turkeys) was determined by intramuscular administration of high virus doses to day-old specific-pathogen-free rhode island red (rir) chickens, which are extremely md-susceptible. paralysis and neuritis were observed in 88% of rir chickens inoculated with mdv cvi-988 at the cell-passage level of the commercial vaccine ... | 1986 | 3015112 |
| protective efficacy of marek's disease virus (mdv) cvi-988 cef65 clone c against challenge infection with three very virulent mdv strains. | comparative 50% protective dose (pd50) assays were performed using a plaque-purified preparation of marek's disease virus (mdv) strain cvi-988 at the 65th chicken embryo fibroblast (cef) passage level (mdv cvi-988 cef65 clone c) and three commercial md vaccines: herpesvirus of turkeys (hvt) fc126, mdv cvi-988 cef35, and a bivalent vaccine composed of hvt fc126 and mdv sb-1. in addition, comparative pd50 assays were performed in groups of chickens with maternal antibody to each of the three vacci ... | 1986 | 3015113 |
| chronological observations of marek's disease-associated feather-pulp lesions in field chickens. | fourteen test groups consisting of a total of 541 field chickens in six rearing farms, all of which were vaccinated with turkey herpesvirus at one day old, were investigated for chronological changes in marek's disease (md)-associated feather-pulp lesions (fpl) and their association with nuclear-inclusion (ni) formation in the feather-follicle epithelium (ffe) and with incidence of md. the fpl observed were categorized into r1-type (non-tumorous lymphoid lesion), r2-type (inflammatory lesion con ... | 1986 | 3015114 |
| use of lectins to detect and differentiate subtypes of marek's disease virus and turkey herpesvirus glycoproteins in tissue culture. | biotinylated lectins in conjunction with an avidin-biotin-peroxidase complex were used for the first time to reveal glycoproteins in chicken and duck embryo fibroblasts infected with three prototype members of the avian herpesvirus group, marek's disease virus serotypes 1 and 2 and turkey herpesvirus. by using a panel of 10 lectins, a pattern of reactivity emerged which was both group- and type-specific. morphological details of the lectin-stained cells include cytoplasmic granulation, capping a ... | 1986 | 3016013 |
| molecular characterization of marek's disease herpesvirus b antigen. | the marek's disease herpesvirus (mdhv) b antigen (mdhv-b) was identified and molecularly characterized as a set of three glycoproteins of 100,000, 60,000, and 49,000 apparent molecular weight (gp100, gp60, and gp49, respectively) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) after immunoprecipitation from [35s]methionine-labeled infected cells by specific rabbit antiserum directed against mdhv-b (r alpha b), as previously determined by immunodiffusion. further identific ... | 1986 | 3016305 |
| isolation of very virulent pathotypes of marek's disease virus from vaccinated chickens in europe. | two very virulent strains of marek's disease virus were isolated from two separate farms in northern italy that had experienced outbreaks of marek's disease in vaccinated flocks. the isolates were similar to very virulent strains reported in the usa in terms of their enhanced pathogenicity, both for chickens vaccinated with the herpesvirus of turkeys, and for genetically resistant chickens. this first description of very virulent strains of marek's disease virus from outside the usa suggests tha ... | 1986 | 3016970 |
| preparation of monoclonal antibodies against marek's disease virus and herpesvirus of turkeys. | 1986 | 3029494 | |
| similarities and dissimilarities in the structure and expression of viral genomes of various virus strains immunologically related to marek's disease virus. | various strains immunologically related to marek's disease virus (mdv) have been subdivided into three serotypes: serotype 1, pathogenic strains of mdv and attenuated or apathogenic variants derived from them; serotype 2, naturally occurring apathogenic strains of mdv; serotype 3, herpesvirus of turkey (hvt). the viral genome structures of these three serotypes were compared by a simple, practical method using total dna extracted from virus-infected cells instead of viral dna purified from virio ... | 1986 | 2424404 |
| monoclonal antibody to chicken fetal antigen on marek's disease lymphoblastoid cell line mdcc-msb1. | a monoclonal antibody (2h3) to chicken fetal antigen (cfa) expressed on the cell surface of the marek's disease lymphoblastoid cell line mdcc-msb1 was generated. 2h3 reacted specifically with various cells from chicken embryos, especially with fetal red blood cells, fetal bursa-derived lymphocytes, fetal liver cells, and embryo fibroblasts but not with fetal peripheral blood lymphocytes. 2h3 reacted also with all lymphoblastoid cell line cells tested: marek's disease, avian leukosis, and reticul ... | 1986 | 2428485 |
| virus-induced atherosclerosis. herpesvirus infection alters aortic cholesterol metabolism and accumulation. | infection of normocholesterolemic, specific-pathogen-free chickens with marek's disease herpesvirus (mdv) has been shown histologically to lead to chronic atherosclerosis like that in humans. the development of herpesvirus-induced atherosclerosis in vivo and the presence of specific marek's antigen within aortic cells suggested that mdv infection may modify lipid metabolism and lead to significant lipid accumulation. experiments reported herein were designed to determine the types and quantity o ... | 1986 | 2934987 |
| characterization of herpesvirus of turkeys. replication using recombinant dna. | dna has been isolated from herpesvirus of turkeys (hvt) virions and used to construct a partial gene library in pbr-322. the recombinants have been characterized and shown to contain hvt dna inserts. a representative recombinant containing a 5.9-kilobase hindiii fragment was used as a probe to quantitate the yields of hvt dna in vitro and to follow the kinetics of viral dna replication. the data shown that in chicken fibroblasts, viral dna synthesis initiates by about 12-14 hr postinfection and ... | 1986 | 3729874 |
| establishment of a variant type of turkey herpesvirus which releases cell-free virus into the culture medium in large quantities. brief report. | a variant turkey herpesvirus (hvt/vt) which releases 10(5.0) plaque-forming units per 0.1 ml of cell-free virus into the culture medium was established from the prototype hvt fc 126 strain (hvt/wt). many enveloped and naked virions of hvt/vt but only naked virions of hvt/wt were found in the culture medium. by the hindiii restriction cleavage patterns, the hvt/vt dnas were almost identical to those of hvt/wt. the hvt/vt was replication-defective in chickens. | 1986 | 3753201 |
| a study of marek's disease in japanese quails vaccinated with herpesvirus of turkeys. | in a study of outbreaks of marek's disease in quails, 220 adult quails vaccinated with herpesvirus of turkeys (hvt) were examined pathologically and serologically for marek's disease (md). forty-three of the 220 quails exhibited microscopic lesions similar to those of chickens with md. md-virus-specific antigen was found in feather tips of 44 of the 220 birds, and the hvt-specific antibody was found in sera of 56 of the 220 birds by agar gel precipitation. there was a positive correlation betwee ... | 1986 | 3814019 |
| marek's disease: a model for protection against herpesvirus-induced tumours. | marek's disease (md) is a lymphoproliferative disease of chickens caused by a herpesvirus (mdv). several effective vaccines have been developed and md is therefore often considered as a model for studying antitumour vaccines. key factors for the understanding of vaccine-induced immunity are discussed. three serotypes have been characterized: serotype 1 or oncogenic mdv, serotype 2 or non-oncogenic mdv and serotype 3 or herpesvirus of turkeys. the three serotypes have clearly different genomes an ... | 1987 | 2825984 |
| restriction enzyme map of herpesvirus of turkey dna and its collinear relationship with marek's disease virus dna. | the genome of herpesvirus of turkey (hvt) was shown to consist of long and short unique regions flanked by inverted repeats (j. cebrian, kaschka-dietrich, c., berthelot, n., and sheldrick, p., 1982, proc. natl. acad. sci. usa 79, 555-558). in this paper we report the construction of the linkage map of hvt dna for bamhi, hindiii, and psti restriction endonucleases. the maps were constructed by hybridization of 19 cloned bamhi fragments of hvt dna to electrophoretically separated digests of genomi ... | 1987 | 3029976 |
| efficacy of a bivalent vaccine against marek's disease. | a bivalent vaccine was prepared by combining inactivated marek's disease virus and turkey herpesvirus. the efficacy of this vaccine, compared to turkey herpesvirus and inactivated marek's disease virus separately, was studied in unsexed white leghorn chicks which were vaccinated at one day old and then challenged at 21 days old with fowl blood infected with virulent marek's disease virus. the bivalent vaccine appreciably delayed mortality resulting from marek's disease and elicited the highest p ... | 1987 | 3035660 |
| effect of acyclovir on the replication of turkey herpesvirus and marek's disease virus. | the toxicity of acyclovir for chick embryo fibroblasts and its effect on the replication of turkey herpesvirus (strain fc 126) and marek's disease virus (strain hprs 16) multiplied on fibroblast culture was studied. the influence of using acyclovir on the development of the tumour process in birds infected with a virulent marek's disease virus was also determined. acyclovir used in doses below 12.5 micrograms ml-1 proved to be nontoxic for chick embryo fibroblast culture. it inhibited in vitro r ... | 1987 | 3039621 |
| acid alpha naphthyl acetate esterase reacting lymphocytes in the peripheral blood of chickens challenged with marek's disease after vaccination with three different vaccines. | the average percentage of acid alpha naphthyl acetate esterase reacting lymphocytes (aparl) was enumerated in the peripheral blood of chickens challenged with marek's disease after vaccination with either turkey herpesvirus (hvt), inactivated marek's disease virus (imdv) or a mixture of the two (bivalent vaccine). a gradual increase in aparl value was noticed in the vaccinated chickens from day 7 to 70 after challenge with a virulent marek's disease virus. the increase was consistent and signifi ... | 1987 | 3628992 |
| enhancement of natural killer cell activity by marek's disease vaccines. | vaccination against marek's disease with herpesvirus of turkeys (hvt) has been reported to cause increased natural killer (nk) cell activity as detected in vitro against lscc-rp9 target cells. the effect of vaccination with sb-1 (a nononcogenic chicken herpesvirus), hvt and the hvt/sb-1 combination on nk cell activation was compared in marek's disease susceptible (p-2) and resistant (n-2) chickens. birds were vaccinated at 7 days of age and nk cell activity was measured between 3 and 42 days aft ... | 1987 | 18766591 |
| isolation of chicken anaemia agent and marek's disease virus from chickens vaccinated with turkey herpesvirus and lesions induced in chicks by inoculating both agents. | a disease that was characterised by high mortality, necrotic lesions, severe thymic and bursal atrophy, as well as marek's disease (md) lesions, occurred in two young layer chicken flocks vaccinated with turkey herpesvirus (hvt) at hatching. an agent similar to the chicken anaemia agent, designated caa82-2, and a virulent md virus strain, designated md82-2, were isolated from the kidneys of affected chickens. dual inoculation of young chicks with both agents resulted in early mortality associate ... | 1987 | 18766615 |
| embryo vaccination of chickens with turkey herpesvirus: characteristics of the target cell of early viral replication in embryonic lung. | inoculation of turkey herpesvirus (hvt) into chicken eggs at the 17th day of embryonation resulted in recovery of high titres of the virus from the lung of the embryo. infection of the lung was not characterised by extensive virus-induced cell lysis because in situ viral internal antigen (via) of hvt was not detected. examination of single cell suspensions of lungs from embryos at peak viral activity revealed that the target cells of virus infection were adherent and lacked surface antigens dete ... | 1987 | 18766646 |
| depression of vaccinal immunity to marek's disease by infection with chicken anaemia agent. | chicken anaemia agent (caa) depressed protective vaccinal immunity against marek's disease (md) when vaccinated chicks were inoculated with caa at 1 to 14 days of age. in chicks inoculated with caa alone, a typical caa infection as manifested by early mortality, decrease in haematocrit value, severe lymphoid depletion in the lymphoid organs, and aplasia of the bone marrow occurred only when one-day-old chicks were inoculated. when both turkey herpesvirus (hvt) and caa were inoculated, a typical ... | 1988 | 18766691 |
| antigen a gene of marek's disease virus (mdv) detects two mrna species (3.7 and 2.1 kb) in mdv- and hvt-infected cells. | the gene of glycoprotein a of marek's disease virus (mdv) detected to mrna species (3.7 and 2.1 kb) by northern blot hybridization. these two mrna species were also detected in rna extracted from herpesvirus of turkeys (hvt)-infected chick embryo fibroblasts (cef) and from the msb-1 cell line. | 1988 | 3245131 |
| turkey herpesvirus. vii. the evolution of marek's disease in chickens vaccinated at one day of age and challenged at different periods of time after vaccination. | the single comb white leghorn, the cornell s strain chickens vaccinated at one day of age with cell free herpesvirus of turkey (hvt) 100 and 1000 focus forming-units (ffu) per bird were raised in isolatores. at different periods of time the vaccinated and control chickens were reared together with chickens with clinical symptoms of marek's disease previously inoculated with jm-strain of marek's disease virus (mdv) in a separate isolation room throughout the experiment. the specific protective ef ... | 1988 | 2837003 |
| gene sequence and mapping data from marek's disease virus and herpesvirus of turkeys: implications for herpesvirus classification. | purified dnas from marek's disease virus (mdv) and the herpesvirus of turkeys (hvt) were randomly sheared and cloned into the m13 bacteriophage. two-hundred and ten mdv and 130 hvt clones were sequenced to give representative samples of the genome sequences. the predicted amino acid sequences from these gammaherpes-viruses were compared to known sequences from other herpesviruses using computer analysis. thirty-five mdv and 24 hvt genes were identified by comparison with varicella-zoster virus ( ... | 1988 | 2841415 |
| presence of natural suppressor cells in the chicken embryo spleen and the effect of virus infection of the embryo on suppressor cell activity. | spleen cells but not the thymus or the bursa cells of chicken embryos suppressed the in vitro mitogenesis of spleen cells of adult syngeneic or allogeneic chickens. the natural suppressor cell activity of embryo spleen was present at embryonation day 16, reached peak levels at embryonation day 18 and disappeared at hatch. the embryo spleen cells did not by themselves respond to phytohemagglutinin stimulation in vitro. the suppressive effect of embryonic spleen cells on adult spleen cells was pre ... | 1988 | 2845637 |
| the effect of substrate on the production of infectious virus by cells in culture. | herpes simplex virus type i (hsv-1), infectious bovine rhinotracheitis virus (ibr) and turkey herpesvirus were examined for growth in cells cultured on three different substrates. the substrates were glass, deae-dextran and collagen gel. with two of the viruses, hsv-1 and ibr, there were no apparent differences in production as a function of substrate. in contrast, the amount of the turkey herpesvirus which was recovered varied greatly with the substrate. titers were highest on glass, followed b ... | 1988 | 2848844 |
| immune response of chicks inoculated with chicken anemia agent alone or in combination with marek's disease virus or turkey herpesvirus. | 1988 | 2848964 | |
| in situ production of interferon in tissues of chickens exposed as embryos to turkey herpesvirus and marek's disease virus. | chicken eggs at embryonation day (ed) 18 or newly hatched chicks were inoculated with turkey herpesvirus (hvt), marek's disease virus (mdv), or virus-free diluent and, at intervals after inoculation, tissue homogenates of virus-exposed and virus-free chickens or chicken embryos were examined for interferon (ifn) activity. homogenates of lung, thymus and spleen specimens from chickens given hvt at ed 18 had ifn activity. activity of ifn in the lungs was studied further. homogenates of lung specim ... | 1989 | 2475045 |
| augmentation of retrovirus-induced lymphoid leukosis by marek's disease herpesviruses in white leghorn chickens. | our objective was to determine whether the cell-associated herpesvirus vaccines used in chickens to control marek's disease tumors can augment development of lymphoid leukosis (ll) induced by exogenous avian leukosis virus (alv). various single or mixed marek's disease vaccines were inoculated at day 1, and alv was injected at 1 to 10 days, with chickens of several experimental or commercial strains. development of ll was monitored at 16 to 48 weeks in various experiments. in several strains of ... | 1989 | 2536088 |
| nucleotide sequence and characterization of the marek's disease virus homologue of glycoprotein b of herpes simplex virus. | the marek's disease virus (mdv) homologue of the herpes simplex virus (hsv) gene encoding glycoprotein b (gb) has been identified within bamhi fragments i3 and k3 of the 'highly oncogenic' strain rb1b of mdv. the entire nucleotide sequence of the gene has been determined and its predicted amino acid sequence shown to share gross overall structural features with the gb genes of hsv, varicella-zoster virus (vzv) and other mammalian herpesviruses. in particular, all 10 cysteine residues were conser ... | 1989 | 2544666 |
| the role of the reticuloendothelial system in the immunopathology of marek's disease. | the role of macrophages in immunity against marek's disease (md) was studied. chickens of one group were subjected to depletion of macrophages using repeated doses of francil amorphous silica and those of another group were subjected to activation of macrophages using repeated doses of brewer's thioglycollate broth. chickens of a third group were vaccinated with herpesvirus of turkeys fc 126 vaccine followed by depletion of macrophages. chickens of these three groups, as well as groups of health ... | 1989 | 2549684 |
| identification of virus-specific polypeptides by monoclonal antibodies against serotype 2 marek's disease virus. | a total of 41 antibody-secreting hybridoma cells against the hprs24 strain of marek's disease virus (mdv) type 2 (mdv2) have been isolated. of these monoclonal antibodies (mabs), 24 were found by immunofluorescence tests to react specifically with mdv2-infected cells, but not mdv type 1 (mdv1)- or herpesvirus of turkeys (hvt)-infected cells, while eight reacted with mdv1- or mdv2-infected cells and nine with mdv1-, mdv2- or hvt-infected cells. by using these mabs, seven classes of mdv type-speci ... | 1989 | 2552003 |
| studies on the pathology of marek's disease following challenge in chicks vaccinated with three different vaccines. | the pathology of marek's disease (md) was studied in chickens vaccinated separately with three different vaccines, namely herpesvirus of turkeys (hvt), inactivated marek's disease virus (imdv) and a bivalent vaccine. the md-specific mortality following challenge was significantly lower (2.0 per cent) in bivalent vaccinated birds than in those vaccinated with either hvt (5.9 per cent) or imdv (13.7 per cent) alone. the occurrence, extent and severity of gross lymphomas and lymphoproliferative les ... | 1989 | 2555401 |
| a comparative analysis of the sequence of the thymidine kinase gene of a gammaherpesvirus, herpesvirus saimiri. | we present the nucleotide sequence of a region from the genome of the a + t-rich gammaherpesvirus, herpesvirus saimiri (hvs), which includes the coding sequences for the viral thymidine kinase (tk) gene. the organization of genes in this region resembles the homologous region of the epstein-barr virus (ebv) genome and is very compact, using overlapping coding sequences and with nucleotides shared by initiation and termination codons of neighbouring reading frames. the hvs tk is predicted to cont ... | 1989 | 2555434 |
| nucleotide and predicted amino acid sequences of the marek's disease virus and turkey herpesvirus thymidine kinase genes; comparison with thymidine kinase genes of other herpesviruses. | in this paper we present the nucleotide sequences of the thymidine kinase (tk) genes of two avian herpesviruses: a highly oncogenic strain of marek's disease virus (mdv strain rb1b) and its serologically related vaccine virus, the herpesvirus of turkeys (hvt strain fc-126). the predicted coding regions of the two genes are 1029 and 1050 nucleotides respectively, corresponding to polypeptides of 343 and 350 amino acids in length. putative nucleotide- and nucleoside-binding sites have been identif ... | 1989 | 2555435 |
| homologies between herpesvirus of turkey and marek's disease virus type-1 dnas within two co-linearly arranged open reading frames, one encoding glycoprotein a. | the genomes of two avian herpesviruses, marek's disease virus type 1 (mdv1) and herpesvirus of turkey (hvt), share close homology only within certain dna regions. one such homologous region of hvt dna was cloned and sequenced. two open reading frames (orfs) were found in the long unique region, orf1 encoding the glycoprotein a (ga), and orf2 encoding a still unidentified protein. these two hvt-orfs are located at almost the same positions as the homologous mdv1-orfs. the nucleotide sequence homo ... | 1989 | 2558972 |
| genomic difference of herpesvirus of turkeys at low and high passage levels in culture of o1 and fc126 strains. | serial passages in culture of herpesvirus of turkeys resulted in structural genomic changes at the regions common to two virus strains with loss of their protective ability against marek's disease. | 1989 | 2615678 |
| genetic and biochemical characterization of the thymidine kinase gene from herpesvirus of turkeys. | the thymidine kinase gene encoded by herpesvirus of turkeys has been identified and characterized. a viral mutant (atr0) resistant to 1-beta-d-arabinofuranosylthymine was isolated. this mutant was also resistant to 1-(2-fluoro-2-deoxy-beta-d-arabinofuronosyl)-5-methyluracil and was unable to incorporate [125i]deoxycytidine into dna. the mutant phenotype was rescued by a cloned region of the turkey herpesvirus genome whose dna sequence was found to contain an open reading frame similar to that fo ... | 1989 | 2724415 |
| characterization of a highly transcribed dna region of herpesvirus of turkeys. | a highly transcribed dna region of turkey herpesvirus (hvt) codes for multiple species of rna. although the rna is transcribed from both strands of dna, no overlapping complementary transcripts have been detected. the complete nucleotide sequence corresponding to the cdna of one of the hvt transcripts was determined. this sequence is highly homologous to the nucleotide sequence of marek's disease virus antigen gp57-65-coding gene and appears to represent the corresponding hvt-coding gene. | 1989 | 2792768 |
| further characterisation of a variant type of turkey herpesvirus which releases large quantities of cell-free viruses into culture medium. | a variant type of turkey herpesvirus (hvt/vt) which releases large quantities of cell-free virus into its culture medium was compared with the prototype of the fc 126 strain of hvt (hvt/wt) as to the biological and serological characteristics. the lack of replication-defective hvt/vt in chickens was considered to be due to the inability of the virus to infect and replicate in lymphocytes and not to temperature-sensitive defects at 41 degrees c. no obvious antigenic differences were found between ... | 1989 | 18679841 |
| characterization of the gene encoding herpesvirus of turkeys gp57-65: comparison to marek's disease virus gp57-65 and herpes simplex virus glycoprotein c. | a gene encoding herpesvirus of turkeys (hvt) strain fc 126 gp57-65 has been mapped to the viral genome and sequenced. the hvt (fc 126) gp57-65 gene maps to bamhi fragments k1 and m, colinear with the gene from marek's disease virus (mdv) strain ga. hvt gp57-65 gene sequences were compared to the mdv strain ga gp57-65 gene that we sequenced previously. overall, the two sequences are 66% identical, with greater similarity in the 3' proximal two thirds of the genes. hvt gp57-65 gene sequences have ... | 1990 | 2161583 |
| isolation of serotype 2 marek's disease virus from birds belonging to genus gallus in japan. | serotype 2 of marek's disease virus (mdv) was isolated from apparently healthy birds belonging to genus gallus that had no history of vaccination with mdv or herpesvirus of turkeys (hvt). buffy-coat cells from these birds were inoculated onto chicken embryo fibroblast (cef) cultures for primary isolation. thirteen isolates from one golden pheasant and three white silky fowls, three black silky fowls, three japanese long crowers, and three japanese bantams produced herpes-like cytopathic effects ... | 1990 | 2164389 |
| identification of the cross-reactive antigens between marek's disease virus and pseudorabies virus by monoclonal antibodies. | among the 33 monoclonal antibodies (mabs) against pseudorabies virus (prv) examined, three mabs (24-17, 74-26, and 8) were found to react with cells infected with marek's disease virus (mdv)-related viruses by immunofluorescence test. two of the mabs (24-17 and 74-26) reacted with the nuclei of cells infected with mdv serotype 1 (mdv1), mdv serotype 2 (mdv2), and herpesvirus of turkeys (hvt), whereas mab 8 reacted with the cytoplasm of mdv2- and hvt-infected cells. however, none of the mabs agai ... | 1990 | 2164393 |
| isolation of very virulent marek's disease viruses from vaccinated chickens in australia. | very virulent marek's disease viruses (vvmdv), defined as isolates against which the herpesvirus of turkey (hvt) vaccine provide poor protection, have been isolated from poultry flocks in both the united states and europe. twenty-one samples from vaccinated australian flocks, experiencing problems with excessive marek's disease (md), were tested for the presence of transmissible md viruses (mdv). of the 16 samples which contained a transmissible agent, 14 were pathogenic in chickens, based on th ... | 1990 | 2171476 |
| humoral immune responses to inactivated oil-emulsified marek's disease vaccine. | when inactivated md11/75c vaccine was inoculated into 1-day-old chickens, it stimulated antibodies detectable by enzyme-linked immunosorbent assay (at a titer of 6400) and indirect fluorescent antibody test (at a titer of 640), but lacking virus-neutralizing activity. chickens passively inoculated with these antibodies were protected against bursal atrophy, weight loss, and early mortality when challenged with the virulent md5 strain of marek's disease virus (mdv). that led to the conclusion tha ... | 1991 | 1659363 |
| attenuated revertant serotype 1 marek's disease viruses: safety and protective efficacy. | in earlier studies, a revertant serotype 1 marek's disease virus (mdv), clone md11/75c/r2, was found to be a highly protective vaccine virus but was mildly pathogenic for susceptible chickens. the term "revertant" indicates that the virus, after attenuation, gained virulence following backpassage in chickens. the present study is an attempt to develop a more attenuated but still protective vaccine virus from md11/75c/r2. forty-two derivative viruses or clones from md11/75c/r2 were evaluated. two ... | 1991 | 1664721 |
| identification of viral proteins encoded by two dna fragments of herpesvirus of turkeys (hvt). | herpesvirus of turkeys (hvt) vaccine is used worldwide to immunize chickens against marek's disease (md). polyclonal antiserum directed against one virus cross-reacts with proteins of the other, while only 5% homology at the dna level was demonstrated between the two viruses. a partial library of hvt dna fragments ranging from 1.5 to 13.5 kbp in size was constructed in pbr 322. under stringent conditions of hybridization (low salt concentration, 10% dextran sulfate at 68 degrees c), two of the c ... | 1991 | 1722930 |