Publications

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 ...	1976	186008
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.	1976	196818
[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 ...	1976	64031
the role of herpesviruses in marek's disease lymphoma of chickens.		1976	185662
[differentiation of antibodies against turkey herpesvirus and 2 serotypes of marek's disease virus in the sera of farm chickens].		1976	183416
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 ...	1976	183650
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 ...	1976	180958
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 ...	1976	175029
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 ...	1976	175018
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 ...	1976	175924
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 ...	1976	175926
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 ...	1976	179946
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 ...	1976	176410
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 ...	1977	191411
[effect of izatizon and ol-56 on the reproductive and transformational properties of marek's disease virus].		1977	191986
rejectability of virus-induced tumors and nonrejectability of spontaneous tumors: a lesson in contrasts.	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) ...	1977	194366
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 ...	1977	197249
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 ...	1977	196577
[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 ...	1977	72346
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 ...	1977	203872
cell-mediated cytotoxic response to cells bearing marek's disease tumor-associated surface antigen in chickens infected with marek's disease virus.	in 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.	1977	68120
[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 ...	1977	189455
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 ...	1977	198688
[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 ...	1977	198968
pathogenicity of low-virulence marek's disease viruses in normal versus immunologically compromised chickens.	to 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, ...	1977	199152
[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.	1977	200014
[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- ...	1977	200016
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 ...	1977	201143
isolation of marek's disease herpesvirus of low pathogenicity from commercial chickens.		1977	201237
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 ...	1977	190413
susceptibility of turkeys to georgia strain of marek's disease virus of chicken origin.	two experiments were conducted to study the susceptibility of turkeys to georgia strain of marek's disease virus (mdv). one-day-old chickens and turkeys were experimentally inoculated with marek's disease (md) infective plasma (experiment 1) or tumor homogenate (experiment 2) and raised in isolation for 29 weeks. the mdv inoculums were pathogenic for chickens and turkeys and caused high mortality (chickens, 100% and turkeys, 70%). macroscopic lesions of md were observed in liver, spleen, lungs, ...	1977	931149
immune responses of chickens fed the androgen analog mibolerone.	mibolerone, an androgen analog (17 beta-hydroxy-7-alpha, 17-dimethylestr-4-en-3-one), induces a slow but progressive involution of the bursa of fabricius when fed to chickens at microng levels during the first 7 weeks of life. chickens receiving mibolerone remained immunologically competent, evidenced by: 1) their antibody response to nonreplicating antigens and infectious antigens; 2) the number of antibody-producing cells in their spleens; 3) the stimulation of their peripheral leukocytes with ...	1977	405963
isolation and characterisation of herpes virus from turkeys.	turkey herpesvirus (hvt) was isolated from the kidneys of 6 of 8 turkey poults from two flocks. the isolates were identified by syncytial-type of cytopathology, inhibition of plaque formation by 5-bromodeoxyuridine, formation of cowdry type a intranuclear inclusions in cell cultures, and presence of herpes-type virions in negatively stained preparations and thin sections of infected cell cultures. one of these isolates inoculated into chickens proved apathogenic over an observation period of 10 ...	1977	614022
cell-mediated immunity to tumor antigen in marek's disease: susceptibility of effector cells to antithymocyte serum and enhancement of cytotoxic activity by vibrio cholerae neuraminidase.	spleen cells from chickens inoculated 7 to 8 days previously with marek's disease virus were cytotoxic for 51cr-labeled cells of a marek's disease lymphoblastoid cell line (msb-1 line) in a 4-h in vitro cytotoxic assay. the cytotoxic activity of spleen cells was inhibited by pretreatment with antithymocyte serum and complement, but not with complement alone or in combination with anti-bursa cell serum or normal preimmune serum. the conclusion was that the effector cell in the above cytotoxic ass ...	1977	302827
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.	1977	204277
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 ...	1977	192834
lymphoproliferative diseases of fowl: jm-v leukemic lymphoblasts in cell culture.	jm-v 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 ...	1977	195070
marek's disease virus-induced antigens in relation to immunity.	protection experiments using isolated marek's disease (md) antigens were performed in antibody-free rhode island red chickens. in addition to virus a antigen (mdv-a) and herpes virus of turkeys (hvt)-induced intracellular (hvt-via) antigens, tumour-specific antigens from the lympho-blastoid msb-1 cells were prepared and isolated plasma membranes were used as vaccines. neither the tested mdv-a and hvt-via nor tumour-specific marek's disease antigens induced statistically significant protection in ...	1977	18770329
disinfection of marek's disease virus in poultry dust.	dust samples from farms contaminated with marek's disease virus (mdv) were exposed to various disinfectants under experimental and field conditions. after the disinfection treatment, examination was made for the presence and oncogenicity of surviving mdv by the inoculation of tissue cultures and susceptible chickens. a combination of formaldehyde vapour and a preparation based on iodine bound to organic carriers appeared to be the most effective for disinfection.	1977	18770332
further characterisation of the cvi 988 strain of marek's disease virus.	the cvi 988 strain of marek's disease virus (mdv) has been studied for markers in vitro and in vivo. it was shown by indirect immunofluorescence assays that this strain belonged to the hprs-16 serotype of md viruses. the virus was positive for precipitating 'a' antigen. medium plaques were produced in cell cultures. therefore the cvi 988 strain could not be distinguished in vitro from other virus strains of the same serotype. the cvi 988 strain proved to be pathogenic for genetically susceptible ...	1977	18770348
cross-protection between jmv marek's disease-derived tumour transplant, marek's disease and turkey herpesviruses.	cross-protection tests were conducted using attenuated jmv (jmv-a) marek's disease-derived lymphoblasts, glutaraldehyde-treated jmv tumour cells, attenuated marek's disease virus (mdv, strain hprs-16/att) and turkey herpesvirus (hvt, strain fc126) as vaccines, and virulent jmv and mdv (hprs-16) for challenge. the jmv and jmv-a preparations were free of mdv, leukosis and reticuloendotheliosis viruses. vaccination of chickens with attenuated mdv or with hvt provided good protection against both jm ...	1977	18770345
quantitative pathogenicity of marek's disease virus and vaccine virus strains in chickens: macroscopical aspects.	two virulent strains (jm and k) and one vaccine strain (cvi 988) of marek's disease virus (mdv), together with two vaccine strains of the herpesvirus of turkeys (hvt) (fc 126 and pb-thv 1), all in the cell-associated state, were administered intramuscularly at 3.7 log tcid50 per dose to day-old spf white leghorn chickens. a control group of chicks received uninfected cells. the pathological parameters studied were onset and duration of clinical symptoms, mortality, bird weight and macroscopical ...	1978	18770360
absence of marek's disease virus antigen in the feather follicle epithelium of vaccinated chicks demonstrated by immunofluorescence.	in chickens vaccinated with mdv strain cvi 988, hvt strain fc 126 or pb-thv 1, no mdv-specific antigens could be demonstrated in the feather follicle epithelium by immunofluorescence (if). in chickens given virulent mdv strains, the epithelium of the feather follicle was positive in if. in an experiment where chickens were vaccinated with strain cvi 988, positive if was observed in the lung, bursa and pancreas, but not in the feather follicle epithelium, kidney, cloaca, or caecal tonsils. absenc ...	1978	18770361
protection against the jmv marek's disease-derived transplantable tumour by marek's disease virus-specific antigens.	chickens immunised with inactivated chicken kidney cells infected with marek's disease (md) virus were protected against the lethal effects of inoculation with the md-derived tumour transplant jmv, which appears not to express viral antigens. it is concluded that the distinction between md virus-specific and tumour-specific antigens is not as complete as has been thought.	1978	18770382
vaccination of bursectomised chickens with inactivated marek's disease virus-specific antigens.	bursectomised chickens were protected against marek's disease (md) by vaccination with inactivated md virus-specific antigens. the immunity was associated with lowered lymphocyte-associated md viraemia following challenge. evidence is presented that the immunity was not dependent on a humoral immune response but possibly on the presence of lymphocytes sensitised to virus-specific antigens.	1978	18770396
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 ...	1978	213610
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 ...	1978	215543
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 ( ...	1978	204600
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.	1978	208974
biochemical evidence of the nonintegrated status of marek's disease virus dna in virus-transformed lymphoblastoid cells of chicken.		1978	209622
[immunogenic activity of vaccines against marek's disease].		1978	210559
pathogenesis of marek's disease: early appearance of marek's disease tumor-associated surface antigen in infected chickens.	marek's disease tumor-associated surface antigen (matsa) appeared in different lymphoid tissues of p-line chickens soon after they were infected with bc-1 strain of marek's disease virus. matsa-bearing cells first appeared in spleens by 5 days post infection (pi) and were observed through a 21-day experimental period at mean levels varying from 3.8 to 21.9% of the total cells examined. lower percentages of matsa-bearing cells were observed in the thymus, in the bursa of fabricius, among peripher ...	1978	357748
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 ...	1978	211085
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.	1978	211242
density-gradient separation of spleen-cell subpopulations from marek's disease virus-infected chickens.	ficoll gradient separation of spleen-cell suspensions has shown that depressed t-cell mitogen reactivity in cultures of jm-vs and md cells results from selective depletion of mitogen-responsive t-cells.	1978	312761
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.		1978	219826
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 ...	1978	219836
suppression of mitogen-induced proliferation of normal spleen cells by macrophages from chickens inoculated with marek's disease virus.	spleen cells from chickens 7 days after inoculation with marek's disease virus (mdv) responded poorly to stimulation by phytohemagglutinin (pha). addition of these cells to syngeneic normal spleen cells caused of marked suppression of the pha response of the normal cells. the mdv spleen cells also inhibited the dna synthesis of msb-1 lymphoblastoid cells in vitro. the suppressive activity is attributed to the presence in mdv spleen cells of a population of suppressor cells with characteristics t ...	1978	659861
transfer to chick embryos of incompatible dna.	after the transfer of chicken dna to chick embryos incompatible at the b locus a retardation of growth was observed. retarded differentiation of muscle fibres was histochemically detected in hatched chicks by the demonstration of enzymatic activities. the manifestations of apparent weakness of the dorsal muscles resembled a "myasthenia-like" syndrome. infection with marek's disease virus was not responsible for the damage caused by transferred dna.	1978	700217
[intravital diagnosis of chicken infection with marek disease virus by a modified method of detecting virus-specific antigen in feather follicle epithelium].		1978	735022
marek's disease virus-induced tumor transplants: development and rejection in various genetic strains of chickens.	this study compares the ability of strains of chickens of varied genetic resistance to marek's disease (md) to resist or regress both local and general reactions to transplantable tumor cells induced by a variety of md virus strains and to transmissible lymphoid tumor cells (olson's tlt) induced by an avian leukosis-sarcoma retrovirus. previous studies have dealt with only a single md transplant. three conclusions can be drawn from our data: 1) md virus infection alone could induce progressive t ...	1978	749890
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 ...	1978	219833
[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 ...	1978	219586
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.	1978	221372
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 ...	1978	221387
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 ...	1978	221388
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.	1978	24754
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 ...	1978	76681
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 ...	1978	76680
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 ...	1978	29134
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 ...	1978	212000
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 ...	1978	209430
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 ...	1978	209437
[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 ...	1978	209603
[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 ...	1978	99864
studies on the mechanism of vaccinal immunity to marek's disease.		1978	93038
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 ...	1979	90665
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 ...	1979	222692
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. ...	1979	222694
expression of genetic resistance to an oncogenic herpesvirus at the target cell level.		1979	223067
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 ...	1979	223539
nonprotective and temperature-sensitive variants of marek's disease vaccine viruses.		1979	214607
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 ...	1979	225277
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 ...	1979	225531
increased agglutinability and haemadsorption of marek's disease hprs line 1 lymphoblastoic cells after concanavalin a treatment.	the hprs line 1 lymphoblastoid cells derived from an ovarian lymphoma induced by marek's disease virus in chickens displayed increased agglutinability and haemadsorption when incubated with con a. the increase was proportional to the concentration of con a used. the same con a-untreated cells and normal chicken lymphocytes incubated with con a exhibited no increase in agglutinability and haemadsorption, however.	1979	231521
serum protein changes in chickens with experimental marek's disease.	serum protein alterations in chickens contact-exposed to marek's disease virus (mdv) were studied by crossed immunoelectrophoresis. total protein values of infected chickens were initially, i.e. in the 4th week, low and later not significantly changed from those of the controls. in all infected chickens a significant increase was seen in the igg components. three of 6 infected chickens showing a prolonged period of clinical illness presented the most pronounced changes in other serum proteins, m ...	1979	523311
pathogenicity of a marek's disease virus for chickens vaccinated with graded doses of herpesvirus of turkeys.	six different groups of one-day-old chickens were vaccinated with herpesvirus of turkeys (hvt) vaccine at doses of 0, 4, 16, 64, 256 and 1,024 plaqueforming units. at 9 days of age they were challenged with an acute strain of marek's disease herpesvirus (mdhv). gross and microscopic lesions in nerves and gonads were investigated and combined for quantitative expression of mdhv pathogenicity. including the microscopic lesions improved the accuracy of the hvt doses/mdhv response. the qualitative a ...	1979	546406
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.	1979	224109
atheroarteriosclerosis induced by infection with a herpesvirus.	atheroarteriosclerosis closely resembling that in humans was induced in normocholesterolemic and hypercholesterolemic chickens by infection with marek's disease herpesvirus (mdv). four comparably sized groups of chickens were used. each group was initially fed a diet relatively poor in cholesterol. group i and ii were inoculated intratracheally at 2 days of age with mdv. at 15 weeks, one group of virus-infected chickens (group ii) and one group of uninfected controls (group iv) were fed a 2% cho ...	1979	382868
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 ...	1979	228107
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 ...	1979	228368
comparative pathogenesis studies with oncogenic and nononcogenic marek's disease viruses and turkey herpesvirus.	an 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 ...	1979	229747
intracellular state of marek's disease virus dna in two tumour-derived chicken cell lines.		1979	230282
comparative studies on marek's disease virus and herpesvirus of turkey dnas.	dna of marek's disease virus (mdv) was compared to that of herpes virus of turkey (hvt). centrifugation of the two virus dnas in neutral glycerol and cscl density gradients showed that the mdv genome was slightly larger than that of hvt and that the buoyant density (1.705 g/ml) of mdv dna in cscl gradients was slightly lower than that (1.707 g/ml) of hvt dna. mdv and hvt dnas were digested with either ecori or hindiii restriction endonuclease and analysed by 0.5% agarose gel electrophoresis. the ...	1979	230299
marek's disease in chickens: correlation of marek's disease with nuclear-inclusion formation in feather-follicle epithelium.	the dynamics of nuclear-inclusion (ni) formation in feather-follicle epithelium of chickens inoculated with marek's disease virus (with or without prior immunization with turkey herpesvirus) could be divided into two patterns: 1) transient ni formation at the initial stage postchallenge; and 2) persistent ni formation. incidence of marek's disease was closely correlated with the dynamics of ni formation. active ni formation recurred in chickens showing pattern 2 and was closely related to the in ...	1979	230801
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 ...	1979	230806
effect of culture temperature on the production of marek's disease virus antigens in a chicken lymphoblastoid cell line.		1979	231431
establishment of marek's disease lymphoblastoid cell lines from chickens with babk of b blood groups.		1979	231432
marek's disease virus and herpesvirus of turkey noninfective to chickens, obtained by repeated in vitro passages.	the relation between the passage level of marek's disease virus, c2 strain, and of herpesvirus of turkey (hvt), o1 strain, in cell culture and the level of the serological response of chickens to these viruses was examined. in both cases the immune response of chickens to these viruses decreased with increase in the number of in vitro passages of virus. virus was not recovered from chickens inoculated with hvt highly passaged in vitro, which had become a high producer of cell-free virus in vitro ...	1979	231437
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 ...	1979	232690