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
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
[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
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
isolation of marek's disease virus from affected chickens. 1975170571
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
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
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
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
[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
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
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
[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
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
[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
marek's disease: epizootiology, control and relationship to oncornaviruses. 1975183670
the role of herpesviruses in marek's disease lymphoma of chickens. 1976185662
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
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
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
studies on the mechanism of vaccinal immunity to marek's disease. 197893038
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
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
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
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
isolation of marek's disease virus dna from infected cells by electrophoresis on polyacrylamide gels.marek's disease virus dna isolated from the nuclear fraction of infected chicken embryo fibroblasts and sucrose-purified particles was electrophoresed on 3 per cent polyacrylamide gels and was compared in its electrophoretical behaviour with isolated pseudorabies and herpes simplex dna, strain hf. the dna molecules eluted from the gel were identified by their sedimentation coefficient (53--55s) and buoyant density (1.707 g/ml) to be of viral origin. mdv dna molecules were electrophoretically als ...1977196577
isolation and identification of marek's disease virus by fluorescent antibody technique.cell-associated herpesvirus related to marek's disease (md) was isolated from the direct culture of kidney cells of naturally infected chickens at taoyuan or by inoculation of clinical specimens to chick kidney (ck) and chick embryo fibroblast cells. the virus isolates replicated in ck or chick embryo kidney cell cultures were identified to be md by the fluorescent-antibody technique.1976196818
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
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
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
[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
[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
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
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
pathological changes in chickens inoculated with reticuloendotheliosis-virus-contaminated marek's disease vaccine.a disease characterized by delayed growth, anemia, abnormal feathers, and leg paralysis occurred among chickens inoculated with marek's disease vaccine over a period from spring to fall in 1974. these chickens were recognized among flocks inoculated with the vaccine produced by two vaccine makers. the affected ones were examined pathologically. gross examination revealed a slight enlargement of peripheral nerves and atrophy of the spleen, thymus, and bursa of fabricius. histopathologically, the ...1977203872
dual virus maturation of both pathogenic and apathogenic marek's disease herpesvirus (mdhv) in the feather follicles of dually infected chickens.infectious cell-free viruses of both pathogenic and apathogenic marek's disease herpesvirus (mdhv) were detected in feather-tip extracts of chickens dually infected with both mdhv isolants either by inoculation or by contact exposure. this indicated concurrent viral maturation of both pathogenic and apathogenic mdhv isolants in the feather-follicle epithelium, resulting in possible double shedding of the two isolants.1977204277
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
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
vaccination immunity to selected diseases in chickens fed the androgen analog mibolerone.chickens fed the androgen analog mibolerone during the first 7 weeks of life regress their bursa of fabricius but can be properly immunized by vaccination against avian pathogens of major economic importance such as newcastle disease virus, infectious laryngotracheitis virus, avian encephalomyelitis virus, infectious bronchitis virus, fowl pox virus, marek's disease virus, and pasteurella multocida, the pathogen causing fowl cholera. these findings on immunocompetence to infectious agents are im ...1978209430
a comparative pathogenesis of two mareks disease virus isolates.the pathogenesis of the jm and ga isolates of marek's disease virus (mdv) infection was compared by studying the sequential tissue distribution of mdv associated antigens with gross and microscopic lesions in infected chickens. with both mdv isolates the initial sites of viral replication were the lymphoid organs, skin, and featers. both the ga and jm isolates were viscerotropic as demonstrated by the presence of mdv antigens with gross and microscopic changes occurring in several visceral organ ...1978209437
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
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
[immunogenic activity of vaccines against marek's disease]. 1978210559
turkey herpesvirus infection in chickens: induction of lymphoproliferative lesions and characterization of vaccinal immunity against marek's disease.chickens vaccinated at hatching with high doses of turkey herpesvirus (hvt) developed viremia that peaked in titer around the 12th day and gradually declined. hvt infection also induced mild microscopic lymphoproliferative lesions in the nerves and gonads. these lesions were most prominent around the 12th day and then regressed. the fact that such lesions were also induced by hvt in cyclophosphamide-treated chicks suggests that they were t-cell-dependent. some of the cells in early hvt lesions a ...1976186008
demonstration of marek's disease tumor-associated surface antigen in chickens infected with nononcogenic marek's disease virus and herpesvirus of turkeys.the presence of marek's disease tumor-associated surface antigen (matsa) was demonstrated on spleen cells from p-line chickens inoculated 5--6 days earlier with herpesvirus of turkeys and sb-1 (a nononcogenic marek's disease virus). antisera against matsa expressed on five marek's disease lymphoblastoid cell lines were able to recognize the matsa present on sb-1-infected spleen cells. no viral membrane antigens and only a low incidence of viral internal antigens could be demonstrated.1978211242
lymphoproliferative diseases of fowl: characterization of transplantable g-b1 marek's disease tumor cells in culture.a transplantable marek's disease tumor, derived and maintained through in vivo passage in syngeneic g-b1 chickens, was established in cell culture and characterized. the cells (gbt cells) grew in suspension and appeared morphologically similar to other marek's lymphoblastoid lines except for prominent nucleoli in gbt cells. the number of chromosomes increased during in vitro cultivation from near triploid to subtetraploid. chromosome no. 3 was abnormally short. the gbt cells retained surface b1 ...1978212000
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
nonprotective and temperature-sensitive variants of marek's disease vaccine viruses. 1979214607
protection against marek's disease-derived tumor transplants by the nononcogenic sb-1 strain of marek's disease virus.a series of experiments was conducted to study the in vivo protection against marek's disease-derived tumor transplants by the nononcogenic sb-1 strain of marek's disease virus. intact, embryonally bursectomized (bx), thymectomized (tx), or cyclophosphamide (cy)-treated chickens of four genetic lines were vaccinated with live or inactivated sb-1. jmv, a non-virus-producing transplant, and ga/tr-1 and mdt-198, two virus-producing transplants were used for challenge. optimal protection against jmv ...1978215543
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
[experiments with the simultaneous or combined vaccination of chicks against marek's disease and newcastle disease].simultaneous vaccination was carried out of day-old chicks against marek's disease (strain c3--1) and newcastle disease (strains b1 and la sota) which did not prove to be effective in conferring a lasting immunity to newcastle disease though it was tolerated without any disturbances whatever. one could resort to it by way of an exception only, with an obligatory revaccination 15 days later, when the unfavourable epizootic status made it necessary. the immunity built up against marek's disease di ...1978219586
transcription of the marek's disease virus genome in a nonproductive chicken lymphoblastoid cell line. 1979219594
marek's disease virus dna in a chicken lymphoblastoid cell line (msb-1) and in virus-induced tumours. 1975191363
in vitro inactivation of cell-free marek's disease herpesvirus by immune peripheral blood lymphocytes.the effect of peripheral blood lymphocytes (pbl) on cell-free marek's disease virus (mdv) was studied in vitro in pbl from intact or embryonal bursectomized (bx) chicks infected with the apathogenic sb-1 isolate of mdv. the pbl were harvested purified and were mixed, 200 or 2,000 to 1, with cell-free ga-5 of mdv. virus survival was assayed after incubation for 1 hour at 36 c by the standard assay for cell-free mdv. pbl from intact but not bx chickens were able to inactivate virus. when the effec ...1978219833
status of endogenous avian rna tumor virus in marek's disease lymphoblastoid cell lines and susceptibility of those lines to exogenous rna tumor viruses.three lymphoblastoid cell lines from marek's disease (md) tumors, two md virus (mdv) producer lines (msb-1 and hprs-1), and a nonproducer line (rpl-1) were studied for the expression of avian leukosis sarcoma (als) viruses. the msb-1 line was free of all known endogenous expressions, including replicating virus (rav-o), group-specific (gs) antigens, and chick helper factor (chf). the rpl-1 and hprs-1 were positive for gs antigens and chf. the rpl-1 and msb-1 lines showed no evidence of an exogen ...1978219836
isolation from a transmissible lymphoid tumour (tlt) lymphoblastoid cell line of a herpesvirus similar to marek's disease virus.a chicken lymphoblastoid cell line (tlt)-6855 originally established from an avian oncornavirus-induced lymphoma (siegfried and olson, 1972) was studied for the presence and expression of marek's disease virus (mdv) genome. by nucleic acid hybridization a significant amount of mdv dna was found in this cell line. this virus dna, however, was not expressed in either virus-specific intracellular or membrane antigens or the md-associated tumour-specific surface antigen (matsa). moreover, mdv-specif ...1977191411
[effect of izatizon and ol-56 on the reproductive and transformational properties of marek's disease virus]. 1977191986
pathogenicity of low-virulence marek's disease viruses in normal versus immunologically compromised learn whether "low virulence" isolants of marek's disease (md) virus have a low inherent oncogenic potential, 3 isolants (cu-1, cu-2, s-11) were given to genetically susceptible s-strain or p-line birds with or without immunosuppressive treatments. based on lesion incidence and type during an 8-10-week experimental period, embryonal (17-day) bursectomy and neonatal cyclophosphamide (cy) treatment were without effect on cu-1 and cu-2 infections in p-lines. s-11 virus was virulent for p-lines, ...1977199152
contrasting characteristics of marek's disease herpesvirus isolated from chickens with and without avian leukosis virus infection.marek's disease herpesvirus (mdhv) isolated from chickens free of naturally occurring avian leukosis virus (alv) infection produced characteristic foci in both chicken embryo fibroblast (cef) and chicken kidney cell (ckc) cultures. mdhv-a, which was extracted from the feather follicle epithelium of chickens naturally infected with alv, did not induce cytologic changes in cef cultures, but did cause focus formation in ck cultures. alv was detected in mdhv-a, but not in mdhv preparations. mdhv-a ( ...1978204600
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
[mechanism of postvaccinal immunity in marek's disease].the apathogenic variant no. 38 of marek's disease virus, kekava strain (mdv-kekava), at the level of the 16th and 45th passages in vitro made chickens resistant to marek's disease when inoculated 14 days before the infection of the chickens with the pathogenic variant no. 55 of mdv-kekava. a simultaneous administration of both variants did not protect the animals against the disease. the occurrence in variants of mdv-kekava of genetic markets manifest upon virus passages in chick embryo fibrobla ...1977198968
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
notes on the mechanism of postvaccination immunity in marek's disease.the investigated 16th and 45th in vitro passages of non-pathogenic variant 83 of the kekava strain marek's disease virus have led in chickens to resistance to marek's disease by introduction of the above-mentioned virus 14 days before application of pathogenic variant 55 of the kekava strain marek's disease virus. simultaneous administration of both variants of the kekava strains marek's disease virus did not protect chickens from the disease. presence in those variants of the kekava strain mare ...1977198688
lymphomas resembling lymphoid leukosis in chickens inoculated with reticuloendotheliosis virus.chickens inoculated as embyros or at hatching with the chick syncytial strain of reticuloendotheliosis virus developed a high incidence of lymphoid neoplasms between the 17th and 43rd weeks of age, involving principally the liver and bursa of fabricius. on the basis of organ distribution, latent period, pathology and surface igm production, the lymphomas closely resembled those of lymphoid leukosis. one inoculated chicken developed a myxosarcoma. no tumors were observed in uninoculated controls. ...1979222694
transcription of the marek's disease virus genome in virus-induced tumors.transcription of the marek's disease virus (mdv) genome in tumor tissues from mdv-infected chickens has been studied by analyzing the hybridization kinetics of (3)h-labeled mdv dna with unlabeled rna extracted from these tissues. lymphoid tumors of ovary, spleen, liver, and kidney contained mdv genomes, but the virus-specific rna sequences were transcribed from less than 15% of the viral dna. a virus nonproductive lymphoblastoid cell line, designated mkt-1, has been established from a kidney lym ...1979225531
[testing the immunogenicity of the dermal antigen in marek's disease virus].an experiment was performed to study the immunogenicity of the dermal antigen of marek's disease virus, extracted from the skin of 30-day-old chickens, infected with marek's disease virus on the first day of life. three kinds of samples were tested: (1) dermal antigen centrifuged at 10 000 g per 0.5 h, (2) dermal antigen centrifugated at 10 000 g per 0.5 h and 100 000 g per 1 h, (3) dermal antigen treated like sample (2) and partly purified by deae-cellulose chromatography. samples (1) and (2) w ...1978209603
biochemical evidence of the nonintegrated status of marek's disease virus dna in virus-transformed lymphoblastoid cells of chicken. 1978209622
suppression and enhancement of mitogen response in chickens infected with marek's disease virus and the herpesvirus of turkeys.the kinetics of phytohemagglutinin (pha) response of peripheral blood lymphocytes from chickens infected with oncogenic marek's disease (md) virus (mdv) or nononcogenic herpesvirus of turkeys (hvt) was studied with a whole blood microassay. at about 7 days after inoculation, a depression in pha response was observed in mdv-inoculated resistant line n or susceptible line 7(2) chickens and in hvt-inoculated line 7(2) chickens. all chickens initially regained their pha responsiveness. susceptible c ...1978211085
[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
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
expression of genetic resistance to an oncogenic herpesvirus at the target cell level. 1979223067
development of cell-mediated immunity to marek's disease tumor cells in chickens inoculated with marek's disease vaccines.chickens inoculated with herpesvirus of turkeys or with apathogenic or attenuated vaccine strains of marek's disease virus (mdv) developed a t-cell-mediated immune response to marek's disease (md) tumor cells. this immune response was detected in a 4-hour 51cr-release assay in which effector cells obtained from spleens of vaccinated chickens were reacted with 51cr-labeled target cells of an md lymphoblastoid cell line (msb-1). the cytotoxic effector cells generated by the vaccine viruses had cha ...1978213610
induction of virus-neutralizing antibody by glycoproteins isolated from chicken cells infected with a herpesvirus of turkeys.the production of virus-induced proteins in chicken embryo fibroblast cells infected with a herpesvirus of turkeys was studied. it was found that glycoproteins isolated from membrane-rich fractions of infected cells by affinity chromatography using concanavalin a induced neutralizing and precipitating antibody in rabbits and chickens. after analytical electrophoresis, such isolates were found to contain three polypeptide bands of between 100 x 10(3) and 120 x 10(3) molecular weight not present i ...1979225277
low incidence of lymphoid tumors in chickens continuously producing endogenous virus.a flock of 258 male and 243 female chickens of a cross of regional poultry research laboratory lines 15b and 7(2) were kept in a filtered-air positive-pressure house and observed for tumors from 100 to more than 729 days of age. these birds produced high titers of a subgroup e endogenous virus from the middle of the embryonic incubation period through the end of the experiment. no neoplasms were observed in the males. the females had two neoplasms indistinguishable from lymphoid leukosis and thr ...1979230806
infection studies on a reticuloendotheliosis virus contaminant of a commercial marek's disease vaccine.reticuloendotheliosis virus (rev) was isolated in cell cultures from commercial marek's disease (herpesvirus of turkeys) vaccine and re-isolated from the organs of vaccinated chickens. runting and feathering abnormalities were produced when 1-day-old specific pathogen free chickens were inoculated with rev. histopathological lesions in infected chickens were hypoplasia of the thymus, bursa and spleen, and inflammation of the proventriculus, kidneys and liver. serological responses to rev were de ...1979223539
enhanced oncornavirus expression in marek's disease tumors from specific-pathogen-free oncornavirus was recovered from cell cultures of kidney tumors from specific-pathogen-free chickens inoculated with marek's disease herpesvirus (mdhv). the mdhv inoculum was free of infectious avian leukosis virus (alv). direct examination of a variety of tissues from mdhv-inoculated chickens demonstrated increased levels of alv-specific rna compared to tissues from diluent-inoculated (control) chickens. dna from cultured kidney tumor cells annealed to an alv complementary dna probe at the sa ...1979216833
non-protective variants of marek's disease vaccine viruses.two variant marek's disease-vaccine viruses failed to induce protective immune responses in chickens and replicated poorly in vivo. one of these, mdv/200d, was defective for growth at 41 degrees c, and clones from this stock had 38 degrees c/41 degrees c plating ratios as high as 10(4). the basis for the poor in vivo replicative ability was not determined.1978221372
the role of the macrophages in marek's disease: in vitro and in vivo studies.macrophages form s- and k-strain leghorn chickens, susceptible and restant to marek's disease (md) respectively, were studied to determine the macrophage contribution to the dynamics of md infection, tumorigenesis and genetic resistance to this disease. in vitro studies demonstrated that macrophages from bothstrains were similar in their responses toward jm strain of marek's disease virus (mdv) and jm-1 tumor cells. macrophages were observed to phagocytize jm virus, but the interiorized virus wa ...1979222692
pathogenesis of marek's disease; effect of immunization with inactivated viral and tumor-associated antigens.inactivated marek's disease virus-infected chicken kidney cells and inactivated msb-1 lymphoblastoid marek's disease tumor cells were used to immunize chickens as virus- and tumor-associated antigens, respectively. immune and nonimmune birds were then challenged by exposure to live virulent marek's disease virus. both vaccines protected significant numbers of chickens (p less than 0.05) against subsequent tumor development, although viral antigen appeared superior to tumor antigen. after challen ...1979232690
[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
marek's disease virus (kekava strain) replication in chickens, chick embryos and cell the course of 12 passages of marek's disease virus (mdv) strain kekava (mdv-kekava) in chickens, the morbidity varied greatly (from 23 to 50 percent). mdv-kekava produced plaques in cultures of chick embryo kidney and adult chicken kidney cells and chick embryo fibroblasts (cef). the virus adaptation to the cultures was very slow. mdv-kekava induced the formation of pocks on the chorioallantoic membranes (cam) of chick embryos but the proportion of embryos with cam lesions did not exceed 24 p ...1975241226
[study of the vaccinating properties of 2 variants of marek's disease virus].the vaccinating properties of two variants of marek's disease virus, kekava strain (mdv-kekava) have been studied. one of them is naturally attenuated, the other has been produced as a result of attenuation of the pathogenic mdv-kekava by long-term passages in chick embryo fibroblast (cef) culture. the vaccinating properties of the naturally attenuated strains (mdv-kekava 83) were first studied in an experiment in which the blood of chicken no. 1683 was used as the vaccine. in paralled. the mdv- ...1977200016
lymphoproliferative diseases of fowl: jm-v leukemic lymphoblasts in cell leukemic lymphoblasts were established in cell culture. the cultured cells (jm-vlc cells) were transplantable in young chicks and produced a disease indistinguishable from jm-v lymphoblastic leukemia as initiated by whole-blood inoculation. jm-vlc cells maintained a normal female karyotype through 13 passages in rhode island red cockerels. with the use of jm-v antisera and antisera from birds with naturally occurring marek's disease (md), specific antigens were detected on the surfaces of l ...1977195070
macrophage restriction of marek's disease virus replication and lymphoma cell proliferation.macrophages are shown to restrict the replication of marek's disease virus (mdv) and isotope uptake by spleen cells from chickens bearing marek's disease (md) tumors. the titer of virus from duck embryo fibroblasts (def) co-cultivation with mdv-spleen cells pretreated to deplete marcophages was 4- to 18-fold higher than with untreated cells. treated mdv-spleen cells increased isotope uptake by 2-fold. these restrictive activities are attributable to macrophage regulation of cell proliferation.1979224109
demyelination in allergic and marek's disease virus induced neuritis. comparative electron microscopic studies.patterns of demyelination were studied in sciatic nerves, spinal roots and ganglia of chickens afflicted with either marek's disease (md) or experimental allergic neuritis (ean). md was induced in susceptible chicks after hatching by inoculation of the jm strain of md herpes virus. tissues from these chickens were examined 7-83 days after infection. ean was studied 10-21 days after sensitization of 4 week old chickens to emulsions containing human peripheral nerve with complete freund's adjuvant ...1977201143
isolation of marek's disease herpesvirus of low pathogenicity from commercial chickens. 1977201237
in vitro establishment of marek's disease herpesvirus-transformed productive and nonproductive lymphoblastoid cell lines.the establishment of two marek's disease herpesvirus-transformed lymphoblastoid cell lines (jmv-1 and jm-1) is reported. cocultivation with chicken embryo fibroblasts, attempts to rescue marek's disease virus from kidney cell cultures, and immunofluorescent staining show that jmv-1 is a nonproductive line and jm-1 is a productive line.1978208974
[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
effectiveness of cell-free or cell-associated turkey herpesvirus vaccine against marek's disease in chickens as influenced by maternal antibody, vaccine dose, and time of exposure to marek's disease virus. 1978219826
transfection studies in vitro and in vivo with isolated marek's disease virus dna.for tranfection studies in vitro and in vivo, infectious marek's disease virus (mdv) dna was isolated from purified virus particles. its sedimentation coefficient in neutral sucrose gradients was found to be 53 +/- 2s and the buoyant density in caesium chloride corresponded to 1.707 g/cm3. the virus dna was also analysed by using the restriction endonucleases ecori and hindiii. high molecular-weight mdv dna precipitated by the calcium phosphate technique was shown to be infectious in cultivated ...1978221387
expression of marek's disease virus in producer and non-producer lymphoblastoid cell lines.continuous in vitro propagation of a producer marek's disease (md) lymphoblastoid cell line reduced the number of cells producing virus antigens and the inducibility of these antigens to 5-iododeoxyuridine (iudr) but did not change the oncogenicity of the cells for chickens. in contrast, propagation of a non-producer md cell line did not change the non-productivity of the cell line, but decreased the transplantability of the cells. the md lines were free of replicating avian leukosis sarcoma vir ...1978221388
inhibitory effects of macrophages against marek's disease virus plaque formation in chicken kidney cell cultures.inhibition of plaque formation by marek's disease virus (mdv) in chicken kidney cell cultures was investigated with the use of peritoneal exudate cells (pec) from chickens. pec from mdv-infected white leghorn chickens inhibited the formation of mdv plaques, whereas the inhibitory effect of pec from chickens vaccinated with herpesvirus of turkey (hvt) or pec from normal chickens was very weak. however, pec from either normal chickens or hvt-vaccinated chickens inhibited the mdv plaque formation i ...1979228107
replication of turkey herpesvirus and marek's disease virus in chick embryo skin organ culture.turkey herpesvirus (hvt) and an attenuated marek's disease virus (mdv) replicated in organ cultures of chick embryo skin as assessed by immunofluorescence and/or electron microscopy. hvt-specific immunofluorescent antigen was detected in the feather follicle epithelium (ffe) and in the surface layer of the skin epidermis. electron microscopy of infected explants revealed herpes-type cytopathology. immature particles of both viruses appeared first in the nucleus. oval or horseshoe-shaped non-enve ...1979228368
comparative pathogenesis studies with oncogenic and nononcogenic marek's disease viruses and turkey apparently nononcogenic marek's disease virus (sb-1) and turkey herpesvirus could be readily isolated from spleen, bursa of fabricius, thymus, and peripheral blood lymphocytes of chickens beginning 4 to 6 days after inoculation, but unlike infections with two isolates of oncogenic marek's disease virus (jm-10 and cu-2), virus replication in these cells was rare, and necrosis in the organs was essentially absent. splenic enlargement was observed regularly during the first 4 to 11 days after in ...1979229747
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