resistance to marek's disease. effect of corynebacterium parvum and marek's tumor cell vaccines on tumorigenesis in chickens.a study of nonspecific stimulation of the avian immune system with corynebacterium parvum and specific stimulation with marek's tumor cell vaccines revealed that nonspecifically stimulated outbred white leghorn-type cockerels had higher incidences of tumors than did controls. a study of tumor cell cytotoxicity of sera from marek's disease virus exposed birds indicated that humoral factors may play some role in tumor resistance.197824754
marke's disease herpesviruses. iii. purification and characterization of marek's disease herpesvirus b antigen.sera from chickens naturally infected with marek's disease herpesvirus (mdhv) form preciptin lines with at least two immunologically distinct soluble antigens designated mdhv-a and mdhv-b. partial purification and characterization of the glycoprotein mdhv-a antigen was previously reported. mdhv-b was found predominantly in the sonically treated extracts of infected cells, in contrast to the predominantly extracellular mdhv-a. analysis of these extracts from 14cglucosamine-labeled cells by immuno ...197829134
report of iabs committee on avian product standardization.the international association of biological standardization (iabs) organized an international symposium in august 1973 on the "requirements for poultry virus vaccines" at lyon (france). the proceedings of this symposium were subsequently published as "developments in biological standardization", volume 25. at the conclusion of this symposium, it was resolved that an avian biological products standardization committee should be established, this committee including four subcommittees, each under ...197838158
mechanism of phosphonoacetate inhibition of herpesvirus-induced dna polymerase.phosphonoacetate was an effective inhibitor of both the marek's disease herpesvirus- and the herpesvirus of turkey-induced dna polymerase. using the herpesvirus of turkey-induced dna polymerase, phosphonoacetate inhibition studies for the dna polymerization reaction and for the deoxyribonucleoside triphosphate-pyrophosphate exchange reaction were carried out. the results demonstrated that phosphonoacetate inhibited the polymerase by interacting with it at the pyrophosphate binding site to create ...197655273
relation between common antigen and membrane antigens associated with marek's disease herpesvirus and turkey herpesvirus infections.the appearance of two kinds of membrane antigen (ma) in marek's disease herpesvirus (mdhv) or herpesvirus of turkey (hvt) infected cells was examined using antiserum to the common antigen (common-ag). no early-appearing ma(ema) was detected in these cultures until 16 hours post-inoculation, after which a number of cells in these cultures had late-appearing membrane antigen (lma) as detected by immunofluorescence (if). fluids from cultures infected with these viruses were examined for the presenc ...197658652
isolation of virus-induced antigens from cells infected with marek's disease and turkey herpesviruses. 197566181
t-lymphoblastoid cell lines from marek's disease lymphomas.the establishment and continuous culture of two lymphoblastoid cell lines derived from marek's disease lymphomas is described. although the cells carried t-lymphocyte surface antigens, they had many features in common with cultured burkitt's lymphoma lymphoblasts, which carry b-cell determinants. a small proportion acted as infectious units in tissue culture, and a similarly small proportion contained intranuclear immature herpesvirus particles. the cells did not respond to phytohaemagglutinin. ...197566182
expression of virus-specific, thymus-specific and tumour-specific antigens in lymphoblastoid cell lines derived from marek's disease lymphomas. 197769011
[structure and function of virus-induced antigens in cultured cells infected with marek's disease and turkey herpes viruses. i. alteration of the immunological specificity of plasma membranes in infected cells (author's transl)].virus-induced proteins were detected in the plasma membranes of cells infected with marek's disease (mdv) and turkey herpes (hvt) viruses and analyzed by biochemical and serological methods. the virus-induced membrane proteins were shown to induce virus-neutralizing antibodies and to protect inoculated chickens against the challenge infection with oncogenic mdv. two virus-induced proteins at least were also demonstrated by the sds polyacrylamide gel electrophoresis in the purified plasma membran ...197772346
herpesviruses and cancer. 197878013
demonstration of chicken fetal antigen (cfa) on normal splenic lymphocytes, marek's disease lymphoblastoid cell lines and other neoplasms.chicken fetal antigen (cfa) was detected on normal splenic lymphocytes and a direct relationship was observed between the percentage of cfa-positive cells and the age of the donor. the fetal antigen was also detected on lymphoblastoid tumor cells and cell lines induced by known avian oncogenic viruses (marek's disease virus and avian leukosis virus), and on spontaneously occurring adenocarcinoma cells. the fetal antigen appears to be distinct from marek's disease tumor-associated surface antigen ...197990665
studies on the mechanism of vaccinal immunity to marek's disease. 197893038
[immunological aspects of marek's disease in chickens with maternal antibodies].the dynamics of the production of immunoprecipitation antibodies to marek's disease virus was studied in the serum of chickens with maternal antibodies in relation to the occurrence of the immunoprecipitation antigens of marek's disease virus in feather follicles. one-day-old chickens were infected by the contact method with marek's disease virus. the first occurrence of immunoprecipitation antigen was detected on the 14th day after infection and this occurrence persisted throughout the experime ...197899864
natural pox and herpes as a dual virus infection in chickens.a natural dual viral infection was confirmed in chickens of university of illinois poultry farm by histopathologic, immunologic, and electron-microscopic examination of formalin-fixed tracheal tissue. histopathologic examination of the tracheal mucosa revealed eosinophilic cytoplasmic inclusions characteristic of fowlpox and intranuclear inclusions suggestive of marek's disease. treatment of the formalin-fixed tracheal tissue with peroxidase and fluorescent-labeled antibody against marek's disea ...1975164178
newer knowledge in comparative virology--its contribution to human health other comparative sciences, and despite its recent beginning comparative virology has already contributed useful applications and observations to human health research. teachings derived from the study of marek's disease found application in that of burkitt's lymphoma, and may lead to a possible vaccine against the human disease. equally useful information came from the study of canine distemper in the development of a chorio-allantoic membrane attenuated measles vaccine, and in our knowled ...1975167504
proceedings: immunization against marek's disease using virus specific antigens free from infectious virus. 1975169863
isolation of marek's disease virus from affected chickens. 1975170571
effects of viruses on immune response. 1975171931
continuous cell culture from lymphoma of marek's disease. 1975169828
effect of cyclophosphamide on the response of chickens to a virulent strain of marek's disease virus.the effect of cyclophosphamide on the pathogenesis of marek's disease was examined in a line of chickens which is relatively resistant to marek's disease. the injection of cyclophosphamide into newly hatched chickens delayed and reduced viremia and also reduced the development of marek's disease lesions until 2 weeks after exposure to marek's disease virus. the data indicate that a population of t cells susceptible to infection with virus and possibly viral transformation is affected by cyclopho ...1975172451
experiments to vaccinate marmoset monkeys against malignant lymphoma.humoral antibodies can be induced in cotton topped (ct) marmosets with killed herpesvirus saimiri (hvs) vaccines. the serum antibodies delayed, but did not prevent, malignant lymphoma in actively and passively immunized monkeys after inoculation with 10(3.8)tcid50 of cell-free hvs. experiments are in progress to determine whether the vaccines are able to protect against smaller challenge dosages of hvs. the immunized monkeys were not resistant against transplantation of tumor cells. infection wi ...1975169814
oncogenesis by marek's disease herpesvirus in chickens lacking expression of endogenous (gs, chick helper factor, rous-associated virus-o) and exogenous avian rna tumor viruses.chickens free of exogenous avian leukosis virus (alv) infection, replicating endogenous alv (rous-associated virus-o), gs antigen, and chick helper factor were fully susceptible to induction of marek's disease (md) by alv-free md viruses. dual infection with rous-associated virus-2 and md virus did not significantly alter the character of the md lesions. thus exogenous alv infection was not requisite for md virus-induced oncogenesis. although participation of endogenous rna tumor virus genes in ...1975169364
influence of vaccination with avirulent herpesvirus on subsequent infection of chickens with virulent marek's disease herpesvirus.vaccination of chickens with turkey herpesvirus (hvt) or attenuated marek's disease herpesvirus (amdhv) blocked infection with virulent mdhv (vmdhv) for approximately 5 weeks after contact exposure. however, there was no apparent blockage of infection when challenge virus was administered intraabdominally (ia). evidence for infection with vmdhv was based on viral isolation by in vivo assay or by detecting precipitins to "a" antigen associated with virulent virus. the hvt stimulated production of ...1975168799
trials with marek's disease vaccines prepared from a turkey herpes virus and an attenuated marek's disease field trials involving over 224,000 fowls in 11 different commercial flocks, three vaccines were used, namely a freeze-dried vaccine prepared from a turkey herpes virus, a cell-associated virus vaccine prepared from the same isolate and a cell-associated vaccine prepared from a strain of marek's disease virus isolated from a fowl. the mortality from marek's disease was reduced by 80 per cent to 95 per cent in birds vaccinated with the freeze-dried vaccine. cell associated vaccines gave slight ...1975168681
testing veterinary vaccines. 1975174269
depression of in vitro responsiveness to phytohemagglutinin in spleen cells cultured from chickens with marek's disease.cultures of dispersed spleen cells, prepared from mdv-infected chickens with md visceral lymphomas, showed marked depression of responsiveness to the t cell mitogen pha, as measured by 3h-tdr incorporation in cells in vitro. when data are expressed quantitatively in terms of cpm/10(5) viable cells, the functional depletion of pha-responsive cells appear to result from lower levels of 3h-tdr incorporation in the pha-stimulated spleen cultures from chickens with acute md symptoms, as compared to s ...1975168267
detection of viral cores having toroid structures in eight herpes viruses. 1975167709
studies of marek's disease herpesvirus and turkey herpesvirus specific common antigen which stimulates the production of neutralizing agar-gel precipitation antigen prepared from the skin (feather-ag) of chicken infected with jm strain of marek's disease herpesvirus (mdhv) and cell extracts of cultures infected with either type 2 plaque producing agent (ppa) of mdhv or turkey herpesvirus (hvt) (type 2-ag, hvt-ag) had 1 precipitation line in common. hyperimmune sera to the common antigen (common-ag) neutralized to a greater extent by homologous antiserum. absorption of hvt antiserum or hyperimmune serum to type 2 ppa with co ...1975167687
vertebrate dna polymerases. 1975166759
antibody response of genetically susceptible and resistant chickens to cell-free and attenuated jm-v leukosis strain and its influence on early type ii (marek's) leukosis infection.experiments were carried out to: 1) determine the antibody response of chickens to cell-free and attenuated preparations of jmv leukosis strain, 2) determine the differences in antibody response to these antigens between susceptible (p-line) and resistant (n-line) chickens by means of serum neutralization and indirect fluorescent antibody tests, 3) investigate the influence of maternal (passive) antibody on early (day-old) jmv vaccination and 4) investigate the influence of maternal antibody in ...1975166367
pathogenic and serologic studies of japanese quail infected with jm strain of marek's disease herpesvirus.japanese quail were inoculated with marek's disease herpesvirus at 1 day of age, and a second group of the same age was infected by contact with inoculated quail. a third group raised in our laboratory as a source of hatching eggs was accidentally infected with marek's disease (md). all quail were observed and examined for periods up to 360 days; the usual clinical signs of md were not observed. however, the birds were susceptible to md infection because of the evidence that: 1) the md-specific ...1975164560
a lymphoproliferative disease in japanese quail.a naturally occurring lymphoproliferative disease was found in 3 flocks of japanese quail in mexico. the tumorlike lesions were detected mainly in livers and spleens. histopathology revealed a pleomorphic lymphoproliferative infiltration with dark-staining large cells, lymphocytes of different sizes, and reticulumlike cells. marek's disease (md) herpesvirus was not isolated from 74 quail tested, nor were antibodies to md detected in 84 sera. antibodies to reticuloendotheliosis (3/24) and avain l ...1976176987
in ovo assay for marek's disease virus and turkey herpesvirus.marek's disease virus (mdv) and the turkey herpesvirus (hvt) may be assayed on the chorioallantoic membrane (cam) of the chicken embryo after intravenous inoculation of chicken embryo fibroblasts (cef) or chicken blood leukocytes infected with these viruses. free hvt, mdv associated with marek's tumor cells, and lymphoblastoid cell lines derived from marek's tumors, may be assayed in the same way. the intravenous assay is quicker than the yolk sac assay and somewhat more sensitive than in vitro ...1975164413
marek's disease in chickens: development of viral antigen in feather follicles and of circulating antibodies.the infection of young chickens with marek's disease herpesvirus (mdhv) leads to the early appearance of viral antigen in the bursa fabricii, in the kidney tubular epithelium, and particularly in the epithelial cells of growing feather follicles (calnek and hitchner, 1969; purchase, 1970). viral antigen may persist in feather follicles over several months, whereas in neural lesions or in lymphoid tumors induced by mdhv viral antigen is either lacking or present only in a few cells (calnek and hi ...1976179946
some effects of silical treatment on marek's disease.treatment of newly hatched chicks with silica by the intraperitoneal route delayed the onset of mortalities due to the jm strain of marek's disease (md' virus inoculated at 6 days of age. during the 88-day observation period fewer silica-treated chicks died of md, but this difference was not usually statistically significant. silica treatment had no effect on the susceptibility of 4-week-old birds. silica treatment reduced the antibody response to md but, in general, not significantly. the antib ...1976179947
a transovarian transmission study of marek's disease in japanese quail.experiments were conducted to determine if transovarian transmission of the jm strain of marek's disease virus (mdv) occurs in japanese quail. in one experiment, parent quail were infected with mdv when one-day-old; in another experiment, parent quail were infected when seven weeks old. no precipitating antigen or cytopathic or infective agent was isolated from the egg yolks, embryos, newly hatched quail, or progeny quail of the infected parents. during the eight weeks observation period, the pr ...1975180501
marek's disease in japanese quail -- a pathological, virological and serological study.experimental studies were performed to see whether japanese quail (coturnix coturnix japonica) are susceptible to jm strain of marek's disease virus (mdv). in three identical trials, a total of 120, one-day-old quail were inoculated intra-abdominally with 0.2 ml. of chicken blood infected with mdv (jm strain) and raised in fapp isolators. uninfected controls were inoculated with normal saline only and raised separately. during the 18-week post infection observation period, 65-80% of the infecte ...1975180503
cyclophosphamide-induced amelioration of marek's disease in marek's disease-susceptible chickens.bursa- and thymus-dependent functions were examined in marek's disease (md)-susceptible normal chickens and in chickens treated with 5 and 16 mg of cyclophosphamide (cy) at the time of hatching. chickens not exposed to marek's disease virus (mdv) and treated with cy temporarily lost mitogenic response to concanavalin a but regained full response after 5 weeks. bursa-dependent functions, such as presence of germinal centers in spleen and cecal tonsils, morphologic features of bursa, and sheep red ...1976180852
in vitro biological differences between the pathogenic and the apathogenic marek's disease herpesvirus.when three pathogenic and four apathogenic isolants of marek's disease herpesvirus (mdhv) were compared, the pathogenic isolants differed from the apathogenic isolants in their in vitro growth and sensitivity to plaque inhibition by dextran sulfate. plaques by the pathogenic mdhv isolants were distinctively different in their morphology from those by the apathogenic isolants, the plaque difference being most pronounced in chick embryo fibroblase (cef) and duck embryo fibroblast (def) cell cultur ...1976180957
a possible association between plaque type and pathogenicity of marek's disease herpesvirus.eighteen isolants of marek's disease herpesvirus (mdhv) were examined for their plaque types in chicken embryo fibroblast cell cultures and their pathogenicity to an experimental line of white leghorns highly susceptible to md. seven isolants (id-1, ga, wsu-gf, and 4 field isolants) induced morphologically similar small-cell plaques (sc plaques) consisting of small round refractile cells, whereas 11 isolants (hn and 10 isolants from zoo birds) all induced large-cell plaques (lc plaques) containi ...1976180958
studies on the pathogenicity of high- and low-passages of a marek's disease virus (cprl ii). 1975163469
properties of a chicken lymphoblastoid cell line from marek's disease of a chicken lymphoblastoid cell line (msb-1) from a marek's disease tumor were studied. the cell line grew well at 41 degrees c in medium rpmi-1640 supplemented with 10% bovine fetal serum and had a doubling time of 8-12 hours. cells grown in stationary suspension culture did not attach to the vessel and had the morphology of typical lymphoblasts. at 37 degrees c, the cell line grew initially but ceased to divide after several subcultures. in the subcultures maintained for 48-72 hour ...1975163334
a phosphonoacetate-resistant mutant of herpesvirus of turkeys.a phosphonoacetate (pa)-resistant mutant of the herpesvirus of turkeys (hvt) was isolated and characterized. the mutant of hvt resistant to pa (hvtpa) replicated in duck embryo fibroblast (def) culture in media containing 300 microgram pa/ml, whereas the replication of the wild type of hvt (hvtwt) was completely inhibited in def culture in media containing 100 microgram pa/ml. the hvtpa was distinct from the hvtwt in plaque morphology, but was indistinguishable antigenically and showed in vitro ...197876681
characterization of an apparently nononcogenic marek's disease virus.a new isolate of marek's disease virus (mdv) was described. this virus, sb, and a clone, sb-1, differed from pathogenic isolates in in vitro growth characteristics as described for other apathogenic isolates. serologically, as with other apathogenic isolates, sb could be distinguished from pathogenic mdv and the avirulent turkey herpesvirus. sb failed to induce lesions characteristic of marek's disease (md) during a 6- to 11-week experimental period. also, sb was nononcogenic in immunosuppressed ...197876680
cell-mediated cytotoxic response to cells bearing marek's disease tumor-associated surface antigen in chickens infected with marek's disease a microcytotoxicity test in which 51cr-labeled cells of a marek's disease (md) lymphoblastoid line (msb-1 line) were used, cell-mediated cytotoxicity of spleen cell suspensions prepared from chickens inoculated with md virus was demonstrated. this cytotoxic response, presumably directed against md tumor-associated surface antigen, was detectable briefly after virus infection and paralleled the appearance of early lymphoproliferative lesions characteristic of md.197768120
application of the turkey herpesvirus vaccine by the aerogenic route for the prevention of marek's disease.recently in laboratory and field trials, birds were vaccinated with cell-free hvt vaccine by aerosol spray. in laboratory trials, birds vaccinated by aerosol spray were as well protected against challenge with virulent md (ga isolate) as those vaccinated by subcutaneous inoculation. birds were vaccinated with a sprayer (spraying systems company, wheaton, illinois) which emits a particle size in which 90% are less than microns. the chicks were sprayed with 1,000 to 10,000 pfu per bird dose and r ...1976182596
pathogenesis of marek's disease. 1976182652
[problems in the immunoprophylaxis of marek's disease]. 1976183346
[differentiation of antibodies against turkey herpesvirus and 2 serotypes of marek's disease virus in the sera of farm chickens]. 1976183416
marek's disease vaccine breaks: differences in viremia of vaccinated chickens between those with and without marek's disease.viremia with turkey herpesvirus (hvt) and/or marek's disease (md) herpesvirus (mdhv) was examined in chickens from three different commercial flocks experiencing "vaccine breaks" following vaccination with hvt vaccine against md. in all groups of sample chickens from the flocks, the incidence of detectable hvt viremia was significantly less in the md-affected than in the healthy penmates, and incidence of md was significantly higher in the birds without detectable hvt viremia than in the viremic ...1976183650
characterization of a new serotype of marek's disease herpesvirus.the hprs-24 strain of marek's disease herpesvirus was selected for closer study from a group of virus isolates that appeared apathogenic under standard test conditons. protection studies revealed an immunological relationship between this virus strain and acute marek's disease herpesvirus. in chicken kidney cell cultures, the hprs-24 strain caused small and slowly developing plaques, and the proportion of infected cells was less than with other strains. in chicken embryo fibroblast cultures, thi ...197566180
[comparative antigenic characteristics of 2 marek's disease virus variants and of herpesvirus of turkeys isolated in the ussr].the antigens induced by pathogenic (55) and nonpathogenic (83) variants of marek's disease virus, the kekava strain (mdv-kekava) and herpesvirus of turkeys, the m-24-72 strain (hvt-m24-72) were tested in the agar gel precipitation test. the antigens were prepared from feather follicles (ff) of the infected chickens, from the infected cultures of chick embryo fibroblasts (cef) and from the culture fluid (cf) of these culttures. in the ff and cef cultures infected with mdv-kekava-83, the synthesis ...197664031
the role of herpesviruses in marek's disease lymphoma of chickens. 1976185662
serological relationship between a pathogenic strain of marek's disease virus, its attenuated derivative and herpes virus of turkeys.precipitating antigens present in extracts of chick embryo cells infected with the hprs-16 attenuated strain of marek's disease virus (att-mdv) were separated by gel filtration on sephadex g200 and some of their properties determined. the two main antigens detected with convalescent md serum, referred to as 'b' and 'c' antigens, had mobilities of 0-55 and 0-25 respectively relative to phenol red on electrophoresis in 7-5% acrylamide gel. the b antigen was relatively stable and of low mol. wt. in ...197551042
influence of some physical factors on survival of marek's disease vaccine virus.cell-associated marek's disease (md) vaccine was suspended at dilutions normally used for vaccination in seven commercially available diluents and in tryptose phosphate broth. the stability of diluted vaccines was determined by assay in cell cultures subjected to 0 to 37 c for 0 to 90 minutes. optimum holding temperatures for md vaccine virus survival varied with the specific diluents employed. some diluents afforded greatest survival when dilution was at 0 c and held at 0 c, while others perfor ...1975987
immunoglobulins and anti-marek's disease virus antibody synthesis in chickens after passive immunization with immunoglobulin y anti-marek's disease virus antibody.the effect of passive immunization with immunoglobulin y (igy) antibody against marek's disease virus (mdv) was examined in mdv-susceptible chickens. the production of igy, immunoglobulin m, and probably also immunoglobulin a was depressed in passively immunized chickens when compared with that in mdv-exposed chickens which had not been given igy anti-mdv antibody. in passively immunized chickens, the synthesis of immunoglobulin m and igy anti-mdv antibodies in response to mdv infection also was ...1975171985
[testing of the protective effect of cell-free lyophilized vaccine against marek's disease in field trials].the protective effect of a lyophilized vaccine against marek's disease ("keramvac"--pfizer), prepared from a cell-free turkey's herpesvirus (strain fc 126), was compared in field trials with losses in the group of non-vaccinated chickens. under the indicated conditions, the vaccine had only a 50.86% effectiveness. the possible causes of the reduced vaccination effect are discussed with regard to the pathomorphological and virological findings suggesting, among others, an increased incidence of t ...1975171821
marek's disease--the disease and its prevention by vaccination.marek's disease (md) is a common lymphoproliferative disease of the domestic chicken caused by a cell associated herpesvirus. vaccines used for the prophylaxis of md have been derived from non-pathogenic field marek's disease virus (mdv), pathogenic mdv and the herpesvirus of turkeys (hvt). vaccines derived from mdv have been developed by attenuation of virus strains which produce the acute form of md and virus strains which produce the classical form. they have also been developed by suitable m ...1975170953
immunization against marek's disease using marek's disease virus-specific antigens free from infectious virus.immunity against marek's disease was conferred by the use of non-infectious materials extracted with non-ionic detergents from cells infected with the attenuated strain of marek's disease virus (mdv). antibody-free rhode island red chicks were inoculated at 1 week of age with cell extracts emulsified in freund's complete adjuvant and were given a second inoculation 1 week later without adjuvant. protection against natural infection was obtained in groups inoculated with both soluble (not sedimen ...1975170213
responses of isolator-derived japanese quail and quail cell cultures to selected animal viruses.thirteen oncogenic and necrotizing animal viruses were assayed in life sciences, inc. (lsi)-specific pathogen-free japanese quail and lsi-specific pathogen-free chicken embryo cell cultures. nine viruses produced similar titers in the quail and chicken cell systems, whereas four viruses showed significantly higher titers in chickens. young japanese quail and chickens were inoculated with five selected avain viruses and maintained in stainless-steel isolators. comparable responses were noted in q ...1975172527
morphological response of maternal antibody-negative chickens infected with marek's disease virus (mdv), herpesvirus of turkeys (hvt) and both viruses. 1975172684
enhancement and interference in chickens inoculated with marek's disease herpesvirus and oncornaviruses.enhancement of mortality rates and symptomatology was observed in isolator-held lsi-spf chickens concurrently inoculated with mdhv and avian oncornaviruses (rav-1, rav-2, rav-7, rav-50, or rev). interference with md antigen production also was demonstrated in extracts of the feather follicle epithelium from chickens inoculated with both mdhv and rav-1.1975174137
[mark's disease: v. experimental behavior of 3 isolates taken place in the country].three experiments were designed to determine the parameters of virus infection, antibodies and mortality with three different md isolates inoculated in one day old birds from commercial origin. the animals were divided in three inoculated lots (1-2-3) and three control groups (4-1, 4-2, 4-3) and were followed weekly from hatching through 17 weeks. the former were inoculated respectivelly with fov-6, fcv-8 and fcv-9. each day old bird received between 50-75 fpu/bird by i.p. route. samples were ta ...1975174161
effect of in vitro adaptation of marek's disease virus on pock induction on the chorioallantoic membrane of embryonated chicken eggs.cell-associated preparations of several isolates of marek's disease virus produced more pocks on the chorioallantoic membrane of embryonated chicken eggs than plaques in duck embryo fibroblasts, thus indicating that lesion response in eggs was more sensitive than cytopathic response in duck embryo fibroblasts for assaying low-passage marek's disease virus. adaptation of the virus to cell cultures by serial passages, however, substantially reduced its pock response so that the titer ratio (plaque ...1976175018
lack of correlation between marena tumor induction and expression of endogenous avian rna tumor virus genome.infection with marek's disease virus (mdv) and subsequent tumor development failed to induce the expression of endogenous avian rna tumor virus genome in line-15i and line-7 chickens which lacked such expression at 1 day of age. titers of avian leukosis virus (alv) group-specific (gs) antigen detected by the cofal test and expression of chick helper factor (chf) activity remained relatively constant in birds which expressed these genome functions at hatching time. endogenous alv belonging to the ...1976175029
[pathogenesis of neural lesions in marek's disease. ii. transmission of neural lesions by spleen cells from ill donors (author's transl) ].viable spleen lymphocytes of 13 chickens with clinical and histological signs of marek's disease were transferred by intravenous injection to 46 chickens 4-10 days old, x-rayed 24 hours before inoculation. histologically marek-like neural lesions were almost regularly observed in the chickens after 6-14 days. chickens having received destroyed spleen lymphocytes of marek-donors were free of nerve infiltrations. there were also no neural lesions detectable within 14 days after application of path ...1975175595
experimental models for dna-rna viral interactions: a brief review.evidences that demonstrate or imply the occurrence of dna-rna viral interactions in man and animals are reviewed. the concurrent presence of two dissimilar oncogenic viruses influenced responses both in vivo and in vitro. cell-mediated immune responses to marek's disease herpesvirus were altered in specific-pathogen-free chickens inoculated as embryos with an avian leukosis virus. the possible roles of immunological factors in the pathogenesis and control of tumor development associated with dna ...1976175924
natural mechanisms of controlling lymphotropic herpesvirus infection (marek's disease) in the chicken.four categories of natural resistance phenomena against mareks disease in chickens, i.e., maternal antibody, age resistance, genetic resistance, and natural immunization, are described. in nature, these forms of resistance probably act in concert through comlex interrelationships. the mechanisms are not well understood but include humoral immunity (maternal antibody), cell-mediated immunity, and possibly other mechanisms. the possible role of newly discovered tumor-specific antigens in cell-medi ...1976175926
effect of phosphonoacetate on marek's disease virus replication.phosphonoacetate (pa), but not any of its analogues tested, effectively inhibited avian herpesvirus replication and viral dna synthesis in cell cultures. at 100 mug/ml culture medium, pa completely inhibited the replication of marek's disease virus (mdv), herpesvirus of turkeys, and owl herpesvirus, but had no measurable effect on normal cell growth. pa also inhibited dna polymerases induced by these avian viruses. enzyme inhibition was 50% at a pa concentration of 0.2 mug/ml. at a concentration ...1976176410
pathogenicity for chicks of line cells from lymphoma of marek's disease.pathogenicity for chicks of the msb-1 line, a cell line derived from the tumorous tissue of a chick with marek's disease (md) and established by akiyama & kato, was studied. five groups, including a control one, of 20 chicks each were inoculated with 1 x 10(3), 1 x 10(4), 1 x 10(5), 1 x 10(6) and no cells of a 180-day culture of the cell line at one day of age. they were housed all together in an isolation unit. an attempt was first made successfully to isolate md virus (mdv) directly in culture ...1976177892
detection of t-cell surface determinants in three marek's disease lymphoblastoid cell lines.the t-cell surface antigens on three lymphoblastoid cell lines, mob1, mob-2 and msb-1, derived from marek's disease lymphomas were examined by the cytotoxicity test and the indirect membrane immunofluorescent test. these cell lines reacted specifically with antisera prepared against chicken thymus cells, although their reactivities were less than that of typical thymus cells. these three cell lines were of thymus origin.1976180968
a lymphoblastoid cell line dually infected with marek's disease virus and avian leukosis virus. 1976180969
lack of expressions of endogenous (gs, chick helper factor) and exogenous avian rna tumor viruses in the mob-1 and msb-1 lines derived from marek's disease lymphomas. 1976180970
induction of marek's disease virus antigens by idurd in a chicken lymphoblastoid cell line.marek's disease virus (mdv) antigens, as detected by immunofluorescence, were induced in a lymphoblastoid cell line, msb-i, in the presence of idurd. when treated with 20 microng/ml of idurd there was no increase in the number of cells producing virus particles. if idurd was removed, an increase in virus production followed. activation of the mdv genome appeared to require incorporation of idurd into cellular dna and occurred during the first 12 h of culture. expression of the activated genome r ...1977192834
[human cancer and herpesviruses. marek's disease. models for eb virus studies]. 1976181615
[effectiveness of a bulgarian vaccine against marek's disease in broilers].studies were carried out to establish the effectiveness of the immunization of broilers against marek's disease using a bulgarian vaccine produced with strain c3-1 of a turkey herpes virus. the experiments were done under the conditions of an industrial poultry dressing combine with a total of 52,450 day-old hybrid birds vaccinated at the rate of 1000 plaque-forming units (pfu), 39,450 birds vaccinated with 500 pfu each, and 91,564 unvaccinated control birds. after the 60-63-day fattening period ...1976181895
marek's disease: epizootiology, control and relationship to oncornaviruses. 1975183670
interaction of marek's disease virus with host cell. 1975183685
bioassay of local mareks disease agent in cell culture. 1976186402
[heterogeneity of a population of the kekaya strain of marek disease virus].while infecting vmd-kekava chick fibroblasts cultures two plaque-forming variants of the virus were isolated. both variants are cell-associated viruses; during a prolonged period these are circulating in the blood of infected chicks, including also healthy ones. the cultures infected contain a common precipitating antigen; sera from the infected chicks have antibodies to vmd feather antigen, both viruses produced, although in a different degree, in the infected chicks lymphoid infiltration of ne ...1976186953
characteristics of jmv marek's disease tumor: a nonproductively infected transplantable cell lacking in rescuable virus.cells of the jmv marek's disease (md) tumor, originally produced by rapid serial passage of md lymphoma cells in chickens, were characterized to determine whether they were of host or donor origin and to ascertain certain virus-host cell interrelationships. differences noted in blood group b surface alloantigens between tumor cells and host lymphocytes indicated a probable nonhost origin (i.e., transplantability) of the tumor. jmv spleen tumors contained predominantly large lymphoblasts bearing ...1976187779
[methods for the control of avian tumour virus diseases (author's transl)].methods developed in the netherlands for the control of avian tumour virus diseases, marek's disease and lymphoid leukosis, are discussed. marek's disease is successfully kept under control by vaccination of all day-old chickens raised for egg production. broilers are not vaccinated. during 1975 over 23 million chicks were vaccinated with cell-associated marek's disease virus cvi 988 vaccines and about 3 million doses of hvt vaccine were administered, mostly in lyophilised form. the mechanism of ...1977189455
dissociation of antiviral and antitumor immunity in resistance to marek's disease.immunization of chickens either with gluteral-dehyde-inactivated chicken kidney cells infected with marek's disease (md) virus or with glutaraldehyde-inactivated cells of md lymphoma-derived continuous lymphoblastoid cell lines protected against md. the former type of immunity was associated with an immunologic suppression of virus replication and virus antigen production after challenge with virulent virus, but lymphocytes specifically cytotoxic to cells bearing md tumor antigens were not detec ...1977197249
antiviral t cell-mediated immunity in marek's disease. 1977197421
[radial immunodiffusion test for the detection of marek's disease virus in hens]. 1976190062
induction of an early antigen of marek's disease virus in a lymphoblastoid cell line. 1975190138
transformation in vitro by herpesviruses - a review. 1975190141
properties of the dna polymerase induced by marek's disease herpesvirus, strain ga, upon infection of duck embryo fibroblasts. 1975190161
[study of the synthesis of rous virus-specific rna in chick embryo cells].the presence of virus-specific rna in commercial chick embryos and its lack in chick embryos of leukemia-free chicken farm of the ussr ams oncological research center as well as in cell cultures from rif-free chicken infected with marek's disease virus was demonstrated by hybridizationof 3h-dna-product of rous sarcoma virus synthesized in vitro in the presence of actinomycin d with the total preparation of cellular rna.1977200014
reduced incidence of marek's disease gross lymphomas in t-cell-depleted chickens.chickens of line 7, highly susceptible to marek's disease (md), were depleted of t-cells by neonatal thymectomy, total-body gamma-irradiation, and multiple injections with antithymocyte serum. in two replicate experiments, significantly fewer gross lymphomas were present in t-cell-depleted chickens than in intact or in t-cell-depleted, reconstituted hatchmates; these findings provided evidence that t-cells may be the principal target for md virus (mdv) transformation, t-cell depletion was not co ...1977190413
a nonproducer t lymphoblastoid cell line from marek's disease transplantable tumor (jmv).a continuous lymphoblastoid cell line was established from a jmv tumor transplant related to marek's disease (md). it is designated rpl1 (jmv) lymphoblastoid cell line. this cell line contains dna sequences complementary to md virus dna and has an antigen similar to md-tumor-associated surface antigen (matsa). however, it lacks any md virus (mdv) rescuable in vivo or in vitro. the cell line has surface antigens typical of chicken thymus cells (t cells) and histocompatability antigens different f ...1977190995
lymphoid cell lines from lymphomas of marek's disease. 1975191350
experimental evidence for influence of type-c viruses on marek's disease virus-associated oncogenesis. 1975191359
marek's disease virus dna in a chicken lymphoblastoid cell line (msb-1) and in virus-induced tumours. 1975191363
vaccination against oncogenic herpesviruses - a review. 1975191377
inhibition of herpesvirus replication and herpesvirus-induced deoxyribonucleic acid polymerase by phosphonoformate.phosphonoformate was found to be an inhibitor of the deoxyribonucleic acid polymerase induced by the herpesvirus of turkeys. the apparent inhibition constants were 1 to 3 mum. phosphonoformate was also able to block the replication in cell culture of marek's disease herpesvirus, the herpesvirus of turkeys, and herpes simplex virus. it was as effective as phosphonoacetate. phosphonoformate was not an effective inhibitor of a phosphonoacetate-resistant mutant of the herpesvirus of turkeys nor of i ...1978206200
an improved method for extracting cell-free herpesviruses of marek's disease and turkeys from infected cell cultures.sonic extraction of cell-free marek's disease herpesvirus (mdhv) and turkey herpesvirus (hvt) from infected cell cultures was improved by incorporating sorbitol in the suspending media. yields of cell-free virus of virulent mdhv were significantly increased with 10% sorbitol added to spga-edta buffer. avirulent strains of mdhv and hvt were respectively readily extracted with spga-edta and spga as the suspending medium, and extraction of their cell-free viruses was moderately improved by adding s ...1978206250
spontaneously occurring lymphoproliferative disease in ducks.a naturally occurring lymphoproliferative disease was observed in a domestic flock of muscovy ducks. gross lesions were observed only in one of three ducks necropsied (in the small intestine). microscopic lesions consisted of mononuclear cell infiltrates composed primarily of reticuloendothelial cells, mature lymphocytes, and plasma cells in livers, spleens, small intestines, peripheral nerves, and brains. antibodies to reticuloendotheliosis virus were detected in sera of four ducks, whereas all ...1978206252
[current problems posed by viruses of the herpes group]. 1977193083
rejectability of virus-induced tumors and nonrejectability of spontaneous tumors: a lesson in contrast to the excellent surveillance against tumors induced by the ubiquitous viruses in their natural host species, spontaneous tumors developing naturally, without experimental interference, evoke little or no rejection reaction. this may be viewed in relation to the natural history of tumors. in most cases, tumors evolve in several steps, with a successful of clonal variants following each other, characterized by increasing independence of host regulations (including immune restrictions) ...1977194366
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