Publications

immunologic profiles of cats with persistent, naturally acquired feline leukemia virus infection.	several immunologic responses were measured in 13 healthy cats with naturally acquired, persistent feline leukemia virus (felv) viremia from 4 multiple-cat households and were compared with responses from 28 of their healthy, non-felv-viremic housemates. significant differences (p = less than 0.05) were not observed between results of felv-viremic and nonviremic cats for peripheral blood leukocyte or lymphocyte count, percentage of peripheral blood mononuclear cells able to form rosettes with gu ...	1986	3021028
demonstration of depressed polymorphonuclear leukocyte function in nonviremic felv-infected cats.	polymorphonuclear leukocytes (pmn) from healthy, normal control cats and felv-infected cats were analyzed for differences in phagocytic capabilities. one week after experimental infection, pmns from felv-infected cats exhibited a marked decrease in phagocytic function as determined by the luminol-dependent chemiluminescent response. depressed pmn function was observed in these cats during the viremic stage of infection and subsequently remained depressed after the cessation of viremia. the data ...	1986	3021292
humoral immune response of asymptomatic cats naturally infected with feline leukemia virus.	the humoral immune response of cats that were naturally infected with the feline leukemia virus (felv) was examined after antigenic stimulation with the synthetic antigen poly(l-tyr, l-glu)-poly(dl-ala)-poly(l-lys). the primary humoral antibody response in felv-infected cats was both delayed and greatly reduced, compared with that seen in uninfected control cats. a similar discordance was observed after secondary stimulation with the antigen, in the felv-infected cats had both a delayed response ...	1986	3022000
infectious feline leukaemia virus is erythrosuppressive in vitro.	the direct effect of the feline leukaemia virus (felv) on erythroid colony formation in vitro was investigated. bone marrow mononuclear cells (bmmc) from felv-naïve, specific-pathogen-free (spf), adult cats were inoculated with felvs of characterized strains and biologically cloned subgroups and the subsequent development of colony forming units-erythroid (cfue) and burst forming units-erythroid (bfue) and colony forming units-granulocyte-macrophage (cfugm) was monitored. exposure to the anaemia ...	1986	3022080
effect of suramin on serum viral replication in feline leukemia virus-infected pet cats.	suramin treatments were administered (iv) to 2 healthy adult cats infected with naturally acquired feline leukemia virus. serum viral infectivity--as assessed by focus induction by the method of fischinger, using serial serum samples titrated on clone 81 cells--ceased transiently in both cats during treatment with suramin, but returned to significantly high levels approximately 14 days after treatment was stopped. both cats tested positive for felv internal antigens in peripheral blood cells and ...	1986	3022623
quantitative studies of erythropoiesis in the clinically normal, phlebotomized, and feline leukemia virus-infected cat.	erythropoiesis was evaluated in 5 cats at base line with normal pcv and then in the same cats with anemia induced by phlebotomy and in 5 other cats with nonregenerative anemia from community-acquired feline leukemia virus (felv) infection. the hematologic evaluation included complete blood cell and reticulocyte counts, marrow morphologic features, determination of serum erythropoietin concentrations by radioimmunoassay, ferrokinetic studies, and in vitro marrow culture of early erythroid progeni ...	1986	3022625
oncogenic viruses of domestic animals.	the objective of this article is to review the relevant oncogenic viruses of small animals. basic scientific principles that have been discovered by research into feline leukemia and other animal cancer viruses have enhanced our understanding of oncogenesis and have led to practical methods of cancer control and prophylaxis.	1986	3024377
monoclonal antibodies. clinical uses and potential.	an overview of monoclonal antibody technology and some examples of its relevance to veterinary medicine are presented in this article. a technical description of the generation of immune spleen cells and hybridization is included. feline leukemia, canine parvovirus, and their respective diseases are included as examples of cases in which monoclonal antibodies can be applied in the diagnosis and characterization of these diseases and their etiologic agent.	1986	3024378
monoclonal antibodies to the v-fes product and to feline leukemia: virus p27 interspecies-specific determinants encoded by feline sarcoma viruses.	monoclonal antibodies to p27 gag and v-fes specific determinants on the gag-onc poly-protein encoded by snyder-theilen feline sarcoma virus (st-fesv) were prepared. in order to obtain hybridoma clones specific to the antigenic determinants encoded by the fesv genome, lou rats were immunized with st-fesv-transformed, virus-nonproducing syngeneic cells, and boosted with either the same cells or affinity-purified feline leukemia virus (felv) p27. three distinct clones reactive to both felv p27 and ...	1986	3024406
disease-specific and tissue-specific production of unintegrated feline leukaemia virus variant dna in feline aids.	feline leukaemia viruses (felvs) have long been known to be associated with induction of proliferative and anti-proliferative diseases of domestic cats. strains of felv have been recognized which specifically induce lymphosarcoma, aplastic anaemia, myelodysplastic anaemia, and, recently, feline aids (acquired immune deficiency syndrome), a naturally occurring immunosuppressive syndrome strikingly similar to human aids which is lethal in 100% of inoculated and viraemic specific-pathogen-free (spf ...	1986	3001539
[enzootic bovine leukosis and feline leukosis. 2 current animal models for the study of virus-induced lymphomas and immunodepression syndrome in man].		1986	3030513
feline leukemia virus infection in a captive cheetah and the clinical and antibody response of six captive cheetahs to vaccination with a subunit feline leukemia virus vaccine.		1986	2851578
feline leukemia virus vaccines.		1986	2853437
control of feline leukaemia virus infection by a removal programme.		1986	3026079
identification of calmodulin activity in purified retroviruses.	several viruses have been shown to require calcium for their function, and to bind calcium at specific sites. however, the nature of the calcium binding molecule on viruses has not been established. one possibility is the ubiquitous calcium-binding protein calmodulin. our studies were designed to determine whether feline leukemia virus contained calmodulin. accordingly, we tested purified feline leukemia virus for the presence of calmodulin-like activity. the virus, like authentic calmodulin, ac ...	1986	3028385
from jenner to jerne: towards idiotype vaccines.		1986	2422113
characterization of a newly established feline lymphoma-derived cell line (bkd) lacking t and b cell surface markers.	a new feline lymphoma-derived cell line, designated bkd, was isolated from an anterior mediastinal tumor. cells of this line were characterized as lymphoid based on morphology, the lack of intracellular esterase and peroxidase activity, and absence of phagocytic function. in contrast with other established feline lymphoma-derived cell lines, cells of the bkd line lack characteristics of both feline t-cells and b-cells in that they neither form rosettes with guinea pig erythrocytes nor have demon ...	1986	2423498
analysis of retroviral pol gene products with antisera raised against fusion proteins produced in escherichia coli.	portions of the pol gene of moloney murine leukemia virus (mulv) were expressed as fusion proteins in escherichia coli, and the purified proteins were used to elicit antibodies in escherichia coli, and the purified proteins were used to elicit antibodies in rabbits. the sera were used to examine the mature pol gene products contained in virion particles and identified the reverse transcriptase and a second protein, p46pol, encoded by the 3' portion of the gene. the p46 protein was not phosphoryl ...	1986	2426463
guinea pig erythrocyte rosette formation as a nonspecific cell surface receptor assay in the cat.	the specificity of guinea pig erythrocyte (gpe) rosettes for feline peripheral blood lymphocytes was studied. of the gpe rosette-positive cells from peripheral blood, 54% were monocytes, 29% were granulocytes, and only 17% were lymphocytes. results were similar for rosettes incubated at 4 c and those incubated at 37 c. mononuclear cells separated with polyvinylpyrrolidone-coated silica formed fewer monocyte rosettes (49%) and more granulocyte rosettes (34%) than did cells separated with sodium d ...	1986	3954230
dysmyelopoiesis in the cat: a hematological disorder resembling refractory anemia with excess blasts in man.	clinical and pathological findings in three cats affected with a myelodysplastic disorder are presented. this hematological disorder resembles that of refractory anemia with excess of blasts as seen in man. the hematological profile in man is one of peripheral cytopenia in one or all of the marrow cell lines which occurs despite a normal to hypercellular bone marrow. quantitatively, the marrow has a preponderance of blasts (up to 20%). qualitative abnormalities consist of dysthrombopoiesis and/o ...	1986	3742354
distinctive peripheral lymph node hyperplasia of young cats.	peripheral lymph node enlargement was found in 14 of a series of 132 feline lymph node biopsy specimens. six of nine cats tested had antibodies for feline leukemia virus (felv). half of the cats were clinically normal while the remainder had fever, lethargy, anorexia, and hepatosplenomegaly. there was severe distortion of lymph nodal architecture with variable loss of discernible follicles and sinuses. histiocytes, lymphocytes, immunoblasts, and plasma cells were present in expanded paracortical ...	1986	3750732
cross-reactivity to human t-lymphotropic virus type iii/lymphadenopathy-associated virus and molecular cloning of simian t-cell lymphotropic virus type iii from african green monkeys.	simian t-lymphotropic retroviruses with structural, antigenic, and cytopathic features similar to the etiologic agent of human acquired immunodeficiency syndrome, human t-lymphotropic virus type iii/lymphadenopathy-associated virus (htlv-iii/lav), have been isolated from a variety of primate species including african green monkeys (stlv-iiiagm). this report describes nucleic acid cross-reactivity between stlv-iiiagm and htlv-iii/lav, molecular cloning of the stlv-iiiagm genome, and evaluation of ...	1986	3491989
the amino-terminal domain of the v-fms oncogene product includes a functional signal peptide that directs synthesis of a transforming glycoprotein in the absence of feline leukemia virus gag sequences.	the nucleotide sequence of a 5' segment of the human genomic c-fms proto-oncogene suggested that recombination between feline leukemia virus and feline c-fms sequences might have occurred in a region encoding the 5' untranslated portion of c-fms mrna. the polyprotein precursor gp180gag-fms encoded by the mcdonough strain of feline sarcoma virus was therefore predicted to contain 34 v-fms-coded amino acids derived from sequences of the c-fms gene that are not ordinarily translated from the proto- ...	1986	3525854
structure of the feline c-fes/fps proto-oncogene: genesis of a retroviral oncogene.	the nucleotide sequence of the feline c-fes/fps proto-oncogene was analyzed. comparison with v-fes and v-fps revealed that all v-fes/fps homologous sequences were dispersed over 11 kilobase pairs in 19 interspersed segments. all segments, numbered exon 1 to exon 19 as in the chicken and human loci, were flanked by consensus splice junctions. the putative promoter region contained a catt sequence and three ccgccc motifs which were also found in the human locus at similar positions. about 200 nucl ...	1987	3553615
viremia, antigenemia, and serum antibodies in rhesus macaques infected with simian retrovirus type 1 and their relationship to disease course.	the course of simian retrovirus type 1 (srv-1) infection was studied in 14 experimentally inoculated juvenile rhesus monkeys. viral transmembrane protein antigenemia and antibodies to whole virus were measured by enzyme linked immunosorbent assay and correlated with the clinical course of disease and virus isolation. based on these parameters, animals with simian retrovirus type 1-induced disease were divided into three categories: monkeys dying within a few months of fulminating simian acquired ...	1987	3599907
isolation of a t-lymphotropic virus from domestic cats with an immunodeficiency-like syndrome.	a highly t-lymphotropic virus was isolated from cats in a cattery in which all the animals were seronegative for feline leukemia virus. a number of cats in one pen had died and several had an immunodeficiency-like syndrome. only 1 of 18 normal cats in the cattery showed serologic evidence of infection with this new virus, whereas 10 of 25 cats with signs of ill health were seropositive for the virus. tentatively designated feline t-lymphotropic lentivirus, this new feline retrovirus appears to b ...	1987	3643650
localization of neutralizing regions of the envelope gene of feline leukemia virus by using anti-synthetic peptide antibodies.	we synthesized 27 synthetic peptides corresponding to approximately 80% of the sequences encoding gp70 and p15e of gardner-arnstein feline leukemia virus (felv) subtype b. the peptides were conjugated to keyhole limpet hemocyanin and injected into rabbits for preparation of antipeptide antisera. these sera were then tested for their ability to neutralize a broad range of felv isolates in vitro. eight peptides elicited neutralizing responses against subtype b isolates. five of these peptides corr ...	1987	2431166
infection of feline lymphoid cells with feline leukemia virus in culture.	an in-vitro system for infection of cat t lymphocytes with feline leukemia virus (felv) was developed. for establishment of this system, felv was inoculated in vitro into concanavalin-a stimulated primary lymphoid cells and long-term cultured t cells grown with interleukin-2 (il-2) from various feline lympho-hematopoietic organs. during serial cultivation with il-2, felv group-specific antigen (gsa) was detected 5-6 weeks after infection in the primary cultures, and 1 week after infection in the ...	1987	2439849
natural feline leukemia virus variant escapes neutralization by a monoclonal antibody via an amino acid change outside the antibody-binding epitope.	we have molecularly cloned a natural variant of feline leukemia virus subtype b. this isolate is unique in that it is not neutralized by a monoclonal antibody which neutralized all other feline leukemia virus isolates tested, including members of the a, b, and c subtypes. western immunoblotting indicated that the monoclonal antibody was less able to bind to the gp70 of the resistant isolate (designated lambda b1) than to the gp70s of susceptible viruses. nucleotide sequence analysis of the envel ...	1987	2444714
demonstration of retroviral proteins associated with erythroid progenitors of cats with feline leukemia virus-induced erythroid aplasia.	feline erythroid aplasia is a fatal retrovirus-induced disease related to infection with feline leukemia virus of subgroup c. when bone marrow cells from cats inoculated with felv were incubated with polyvalent antibody to felv and cultured for erythroid colony formation, a complement-dependent inhibition of erythroid progenitors was demonstrated with virtually complete suppression of erythroid colony-forming units (cfu-e) and burst-forming units (bfu-e) evident from post-inoculation week 4 unti ...	1987	2826931
[the distribution of feline leukemia virus (felv) in switzerland].		1987	2820053
effects of treatment with cobra venom factor on experimentally induced feline leukemia.	five- to six-month-old specific-pathogen-free cats were exposed to cobra venom factor (cvf) alone (4 cats), rickard feline leukemia virus (felv; 9 cats), or cvf and felv (6 cats). host-virus relationships were evaluated by monitoring the development of viremia, production of antibody against feline oncornavirus-associated cell membrane antigen, and amount of circulating immune complexes (cic). exposure to cvf induced complement depletion, which lasted 8 to 15 days. however, complement depletion ...	1987	2820273
influence of inactivated feline retrovirus on feline alpha interferon and immunoglobulin production.	the effect of ultraviolet-inactivated feline leukaemia virus (uv-felv) on the development of feline immunoglobulin-secreting cells (isc) was investigated using a reverse haemolytic plaque assay. low concentrations of uv-felv at 2 x 10(-4) to 2.0 micrograms/ml stimulated the production of isc. by contrast, the same concentration of uv-felv suppressed the development of pokeweed mitogen (pwm)-driven isc. maximum suppression of isc occurred at 50 micrograms/ml of uv-felv. the generation of an inter ...	1987	2820639
retrovirus-induced feline pure red cell aplasia: the kinetics of erythroid marrow failure.	cats viremic with feline leukemia virus subgroup c (felv-c) develop pure red cell aplasia (prca) characterized by the loss of detectable late erythroid progenitors (cfu-e) in marrow culture. normal numbers of early erythroid progenitors (bfu-e) and granulocyte-macrophage progenitors (cfu-gm) remain, suggesting that the maturation of bfu-e to cfu-e is impaired in vivo. we have examined the cell cycle kinetics of bfu-e and their response to hematopoietic growth factor(s) to better characterize ery ...	1987	2821017
retrovirus-induced feline pure red cell aplasia. hematopoietic progenitors are infected with feline leukemia virus and erythroid burst-forming cells are uniquely sensitive to heterologous complement.	feline leukemia virus subgroup c/sarma (felv-c) induces pure red cell aplasia (prca) in cats. just before the onset of anemia, erythroid colony-forming cells (cfu-e) become undetectable in marrow culture, yet normal frequencies of erythroid burst-forming cells (bfu-e)- and granulocyte-macrophage colony-forming cells (cfu-gm) persist. to determine if erythroid progenitors were uniquely infected with retrovirus, marrow mononuclear cells from cats viremic with felv-c were labeled with monoclonal an ...	1987	2821071
molecular cloning of an endogenous cat retroviral element (ece 1)--a recombinant between rd-114 and felv-related sequences. brief report.	a lambda l 47.1 clone library was constructed from bamhi digests of cellular cat dna and was screened with cdna probes specific for the 3'-terminus of the replication competent rd-114 virus. the first analysis of one clone (lambda-ece 1) shows that it consists at least of a 3'-ltr and a 5' adjacent env gene. the ltr nucleotide sequences of the rd-114 cdna clones and ece 1 are identical within the r region and unrelated to felv. otherwise, the region upstream from the 3'-ltr of ece 1 shows homolo ...	1987	2821968
structural abnormality and over-expression of the myc gene in feline leukemias.	tumor cells of feline leukemia were examined for structural abnormality and expression of the myc gene. four of 12 spontaneous leukemia cases showed structural abnormalities of the myc gene detected by southern blotting analysis. of these 4 cases, one (case 1) showed a dna rearrangement in the 5' portion of the c-myc locus associated with integration of feline leukemia virus (felv) genome. another case had a newly inserted myc gene which was transduced by felv. in the 2 other cases, no relation ...	1987	2822586
nucleotide sequence analysis of the ltrs and env genes of sm-fesv and ga-fesv.	the nucleotide sequences of the env genes and the ltrs of sm- and ga-fesv lambda recombinants have been determined by the maxam and gilbert method and/or the dideoxy method with specific sequencing primers. comparison of the two sequences reveals a homology of 93%, the differences being randomly distributed. two frameshift mutations are observed in the ga-fesv isolate which close the reading frame and would prevent the synthesis of the env protein. comparison of these two fesv sequences with the ...	1987	2823466
experimental transmission and pathogenesis of immunodeficiency syndrome in cats.	we describe the identification, experimental transmission, and pathogenesis of a naturally occurring powerfully immunosuppressive isolate of feline leukemia virus (designated here as felv-faids) which induces fatal acquired immunodeficiency syndrome (aids) in 100% (25 of 25) of persistently viremic experimentally infected specific pathogen-free (spf) cats after predictable survival periods ranging from less than 3 months (acute immunodeficiency syndrome) to greater than one year (chronic immunod ...	1987	2823940
cryptosporidiosis in a feline leukemia virus-positive cat.	a 4-year-old felv-positive cat with a 1-year history of intermittent diarrhea and subsequent anorexia, depression, and weight loss had enteric cryptosporidiosis at necropsy. cryptosporidium sp is an important cause of gastroenteritis and diarrhea in various species, including human beings with acquired immunodeficiency syndrome. a major determinant of the severity of the disease caused by cryptosporidium sp is the immunologic status of the affected animal. cryptosporidiosis should be included in ...	1987	2824411
low-dose cytosine arabinoside-induced remission of lymphoblastic leukemia in a cat.	low-dose cytosine arabinoside (10 mg/m2, q 12 h), an antimetabolite chemotherapeutic agent, was administered subcutaneously to a cat with aleukemic lymphoblastic leukemia. after several weeks of this treatment, there was marked improvement in the neutrophil count and pcv, as well as restoration of adequate numbers of normal bone marrow cells. the remission lasted 10 weeks.	1987	2824412
comparison of serological responses in cats vaccinated with two different felv vaccine preparations.		1987	2825396
the role of feline leukaemia virus in naturally occurring leukaemias.		1987	2825985
feline leukemia virus: current status of the feline induced immune depression and immunoprevention.	this is a review of the current knowledge of feline leukemia virus (felv) associated with immune depression observed in cats. it will focus on the clinical and experimental observations associated with feline retroviral infection and presence in vivo and in vitro. we will briefly describe retroviral-associated acquired immune deficiency syndrome associated with felv infection in the cat and specific cellular pathology associated with felv latency. in addition, we will focus on the action of felv ...	1987	2826030
suppression of in vitro neutrophil function by feline leukaemia virus (felv) and purified felv-p15e.	feline neutrophils (pmn) were isolated and exposed to ultraviolet light-inactivated feline leukaemia virus (uv-felv) and purified envelope component p15e (felv-p15e). functional capacity of exposed pmn was measured in vitro utilizing the chemiluminescence (cl) response. pmn exposed to uv-felv demonstrated depressed cl responses to ca2+-ionophore a23187 and latex particles. however, felv-p15e produced significant suppression in the cl response to a23187 but failed to produce significant alteratio ...	1987	3029288
nucleic acid sequence and oncogenic properties of the hz2 feline sarcoma virus v-abl insert.	hardy-zuckerman 2 feline sarcoma virus (hz2-fesv), isolated from a multicentric feline fibrosarcoma is a replication-defective acute transforming feline retrovirus which originated by transduction of feline c-abl sequences with feline leukemia virus (felv) and is known to encode a 110-kilodalton gag-abl fusion protein with tyrosine-specific protein kinase activity (p. besmer, w. d. hardy, e. e. zuckerman, p. j. bergold, l. lederman, and h. w. snyder, nature (london) 303:825-828, 1983). the nucle ...	1987	3029415
retroviral transduction of t-cell antigen receptor beta-chain and myc genes.	support for multistage models of oncogenesis has been provided by several highly leukaemogenic retrovirus isolates that have transduced more than one host cell gene. where functional studies have been performed, these retroviral oncogenes show synergy for in vitro transformation and leukaemogenesis. in naturally occurring feline leukaemias associated with feline leukaemia virus (felv), retroviral transduction of myc is a frequent oncogenic mechanism. but evidence suggesting that the felv v-myc g ...	1987	3029597
feline leukemia virus-associated enteritis--a condition with features of feline panleukopenia.	infection with feline leukemia virus (felv) was demonstrated immunohistologically in 218 necropsied cats suffering from enteritis. the animals were divided into three groups according to histopathological criteria. the first group exhibited the signs of feline panleukopenia in intestine, lymphoid tissues, and bone marrow. only 1.6% of these animals were felv-infected. the animals of the second group had histopathological alterations as seen in cats suffering from feline panleukopenia, but these ...	1987	3029936
effects of feline leukemia virus infection on neutrophil chemotaxis in vitro.	a procedure for measuring in vitro feline neutrophil chemotaxis was developed, using a modified boyden chamber apparatus and 3-microns-pore polycarbonate filters. a pooled feline serum sample was used as the chemoattractant. chemotaxis was evaluated in 5 groups of cats: group 1-specific-pathogen-free cats that had not been exposed to feline leukemia virus (felv); group 2-previremic, felv-infected, specific-pathogen-free cats; group 3-felv-viremic, subclinically affected cats; group 4-felv-viremi ...	1987	3030165
structure and origins of the hz2-feline sarcoma virus.	the hz2-feline sarcoma virus (hz2-fesv) is a replication-defective acute transforming feline retrovirus with oncogene homology to abelson murine leukemia virus (a-mulv) (p. besmer, w.d. hardy,jr., e. e. zuckerman, p. j. bergold, l. lederman, and h. w. snyder, jr. (1983) nature (london) 303, 825-828). in contrast to a-mulv which was isolated from a hematopoietic tumor, the hz2-fesv derives from a multicentric fibrosarcoma. we have molecularly cloned the hz2-fesv provirus from mink hz2-fesv nonpro ...	1987	2884777
feline leukemia virus infection in street cats in tokyo area.		1987	2828737
murine monoclonal antibodies cross-reactive with feline peripheral blood mononuclear cells.	twelve murine monoclonal antibodies (mab), specific for canine, human, and mouse cell surface determinants on lymphohemopoietic cells, were tested for reactivity (using indirect immunofluorescence) with peripheral blood mononuclear cells (pbmc) from 3 normal cats and 3 felv-positive cats with lymphoblastic leukemia. mab dly6 and 1h3, specific for canine lymphocytes, mab hb57s, specific for human mu(igm) chain, mab j-118 40.164.3 and h81.98.71, specific for murine and human ia, all had higher bin ...	1987	2829413
effect of diethylcarbamazine on cats given feline leukaemia virus vaccine.	leukocell (norden laboratories, lincoln, ne, usa), a commercially available retroviral vaccine, is given to protect susceptible cats against feline leukaemia virus. oral diethylcarbamazine, an immunomodulator used in the treatment of filariasis, when given with 1 ml i.m. leukocell, increased titres and duration of serum antibodies to feline oncornavirus-associated cell membrane antigen and transient average monocyte counts in treated/vaccinated cats as compared to cats that received vaccine with ...	1987	2829454
feline leukemia virus and pneumocystis carinii infection.		1987	2830393
idiotype networks in the immune response to feline leukemia virus.		1987	2830503
epidemiology of feline leukaemia virus infections.	in cats the commonest cause of leukaemia and lymphomas is infection with feline leukaemia virus (felv). following infection with this retrovirus some cats eliminate the virus and produce neutralizing antibody whereas others remain latently infected. a final group become persistently infected, and eventually succumb to neoplastic or non-neoplastic diseases induced by the virus. the proportion of cats falling into these different post-infection states depends on the age of exposure and the dose of ...	1987	2832022
viral transduction of host genes in naturally occurring feline t-cell leukaemias: transduction of myc and a t-cell antigen receptor beta-chain gene.		1987	2832272
the zoonotic potential of feline leukemia virus.	the many studies that have addressed the possibility for felv infection in human beings are reviewed in this article. because of the many similarities between felv-induced immune system impairment in cats and retrovirus related acquired immune deficiency syndrome in man, these two conditions are discussed as well.	1987	3031865
feline leukemia virus envelope protein expression encoded by a recombinant vaccinia virus: apparent lack of immunogenicity in vaccinated animals.	we have constructed a recombinant vaccinia virus encoding the expression of the feline leukemia virus (felv) envelope gene of the gardner-arnstein strain of felv subgroup b. human cells infected with the recombinant virus (vfelvenv) express and process the felv envelope protein similarly to cells infected with authentic felv. the mature gp 70 protein is transported to and accumulates on the surface of vfelvenv-infected cells. vaccinia virus replication and felv gp70 accumulation was also observe ...	1987	3031895
clearance of retroviremia and regression of malignancy in cats with leukemia-lymphoma during treatment with staphylococcal protein a.	cats persistently infected with a type c retrovirus (feline leukemia virus; felv) were treated either by the extracorporeal perfusion of their plasma through filter columns containing staphylococcal protein a (spa) or by the intraperitoneal injection of spa for up to 32 treatments. the clearance of evidence of viral infection occurred during treatment with spa in 67% of the treated cats with chronic viral infection that had felv-related abnormalities other than overt malignancy. this rate of vir ...	1987	3032440
the decline in the production of interleukin 2 in cats spontaneously infected with feline leukemia virus.		1987	3033380
altered structure and expression of c-myc in feline t-cell tumours.	the c-myc gene is rearranged in a subset of feline t-cell lymphosarcomas. detailed mapping of c-myc rearrangements showed that some result from feline leukaemia virus (felv) proviral integration within or upstream of c-myc, but one case involves a complex 3' alteration and amplification which is apparently not directly virus-induced. s1 nuclease mapping of rna from normal cells using c-myc probes revealed two presumptive 5' ends, each corresponding to a promoter-like sequence (p1 and p2), and a ...	1987	3033889
3'-azido-3'-deoxythymidine in feline leukemia virus-infected cats: a model for therapy and prophylaxis of aids.	due to similarities between human immunodeficiency virus and feline leukemia virus, the etiological agents of acquired immunodeficiency syndromes in humans and cats, the feline system was used as a model to conduct preliminary investigations as to the efficacy of the thymidine analogue 3'-azido-3'-deoxythymidine (azt) as a therapeutic and preventive agent against retroviruses. in vitro evaluations of azt cytotoxicity and its antiviral effects were conducted. subsequently, 50 6-week-old specific ...	1987	3034403
detection of feline leukemia virus infection in saliva.	the question was investigated whether feline leukemia virus (felv) infection may be diagnosed by testing saliva in an enzyme-linked immunosorbent assay (elisa). saliva was collected with commercially available swabs, eluted from the swabs, and tested in the elisa. a comparison of results with saliva and serum samples from 60 specific-pathogen-free cats, 9 experimentally infected cats, and 1,117 field cats led to the following conclusions. false-positive saliva results, if any occurred, were rare ...	1987	3034965
recombinant feline viruses containing the myc gene rapidly produce clonal tumours expressing t-cell antigen receptor gene transcripts.	we, and others, have recently shown that recombinant feline leukaemia viruses (felv) containing the myc gene (felv-myc) occur in up to 30% of naturally occurring cases of t-cell lymphosarcoma. investigation of the disease spectrum of two felv-myc isolates showed that they induced clonal or oligoclonal t-cell tumours after a short latent period. the phenotypic pattern of the thymic tumours was restricted in that they all expressed the alpha and beta chains of the t-cell antigen receptor and could ...	1987	3036720
feline leukaemia vaccine protection against viral latency.	seventeen cats, which were previously vaccinated with a subunit, feline leukaemia vaccine (leukocell) and subsequently challenged with virulent feline leukaemia virus (felv), were tested at 2 to 4 years postchallenge for reactivation of latent felv infections. administration of weekly doses of methylprednisolone induced significant decreases in lymphocyte numbers, but did not reactivate virus in bone marrow cultures from 15 cats in vivo or in vitro. these cats were observed to be neither persist ...	1987	3037814
frequency and significance of feline leukemia virus infection in necropsied cats.	feline leukemia virus (felv) infection was diagnosed immunohistologically on paraffin-embedded tissues obtained from 1,095 necropsied cats. significant association of felv infection was demonstrated by chi 2 and fisher's tests with various conditions and diseases (ie, anemia, tumors of the leukemia/lymphoma complex, feline infectious peritonitis, bacterial infections, emaciation, felv-associated enteritis, lymphatic hyperplasia, and hemorrhage). unexpected findings associated with felv infection ...	1987	3037951
testing for feline leukemia.		1987	3038803
cyclic hematopoiesis associated with feline leukemia virus infection in two cats.	cyclic oscillations in the numbers of blood elements were detected in 2 cats with felv infection. periodic neutropenia, followed by a return to normal neutrophil numbers, was detected in both cats. the mean cycle duration was 11.8 days, with a range of 8 to 14 days. just before the return of normal neutrophil numbers, monocytosis developed. in 1 cat, cyclic variations in the number of reticulocytes and platelets also were detected. bone marrow aspirates obtained during periods of neutropenia had ...	1987	3038808
saliva as a source of feline leukemia virus antigen for diagnosis of disease.	an enzyme-linked immunosorbent assay (elisa) for detection of feline leukemia virus (felv) p27 in saliva was tested for its accuracy and sensitivity in diagnosing felv infections. saliva and serum samples from 564 clinical cases were tested with a 99.2% specificity. the overall accuracy of the saliva elisa reactive to the serum elisa was 97.9%. experimentally, the elisa saliva was the least sensitive in diagnosing early felv infections. however, the overall accuracy, ease of use, and simplicity ...	1987	3038950
selective removal of antigen-complexed igg from cat plasma by adsorption onto a protein a-silica matrix.	the binding of normal cat igg, heat-aggregated cat igg and specific immune complexes (ic) containing cat igg to a silica matrix containing covalently bound staphylococcus aureus protein a was evaluated. the amounts of serum relative to protein a-silica, the flow rates and the perfusion times were representative of those existing when protein a-silica columns are used for therapeutic extracorporeal immunoadsorption of igg and ic from humans and animals. when cat igg was present in a large excess, ...	1987	3039006
prevalence of feline leukemia virus infection in random source laboratory cats.	three years of quarantine data involving the prevalence of feline leukemia virus (felv) in laboratory cats (felis catus) was evaluated. testing was performed using a commercially available elisa system. annual prevalence of infection ranged from 5.4 to 10.7% of the 937 cats tested. results obtained with the enzyme linked immunosorbent assay (elisa) system compared well with tests performed using an immunofluorescent antibody assay system (ifa). seasonal periodicity was noted with higher infectio ...	1987	3039250
[feline leukemia virus (felv) and felv-associated diseases in cats: a review].	feline leukaemia virus (felv) usually occurs in its natural species, the domestic cat. felv is also important to human individuals as a comparative model, as felv may cause a variety of diseases which are partly malignant and partly benign, such as immunosuppression which bears a resemblance to aids (acquired immune deficiency syndrome) in man. although felv is a common infective agent, the incidence of disease due to felv is much higher in cats kept in closed households in which several of them ...	1987	3039686
[infections with feline leukemia virus (felv) in postmortem cats].	cats presented for post-mortem examination were examined by immune histological techniques for the presence of persistent felv infections. persistent felv infection was found to be the most common fatal infectious disease currently occurring in cats. it was detected in 16 per cent of the cats referred for post-mortem examination, whereas a proportion of 3 per cent may be regarded as likely in the normal population.	1987	3039688
transforming potential of a myc-containing variant of feline leukemia virus in vitro in early-passage feline cells.	we studied a naturally occurring variant of feline leukemia virus (felv) in which the oncogene myc has substituted for a portion of the viral structural genes (myc-felv). myc-felv was rescued by replication in the presence of felv as helper, and its biological activity was examined in early-passage feline cells in vitro. infection of leukocytes from peripheral blood, spleen, or thymus, or of kitten fibroblasts did not immortalize these cells or alter them morphologically. northern blot (rna blot ...	1987	3041029
is an aids vaccine already available?		1987	3041063
effect of feline leukemia virus on the development of plaque forming cells in feline peripheral blood lymphocytes.		1987	3041092
lymphocytes and antibody in retrovirus-induced feline pure red cell aplasia.	the possible role of antibody and t-lymphocytes was investigated in the pure red cell aplasia (prca) associated with feline leukemia virus, subgroup c (felv-c), infection. in previous studies, erythroid colony-forming cells were undetectable in marrow culture of cats with prca. yet erythroid burst-forming cells (bfu-e) remained, suggesting that bfu-e were able to differentiate in vitro but not in vivo. it was inferred that immunologic suppression may contribute to the pathogenesis of feline prca ...	1987	3025500
suppressive effect on polyclonal b-cell activation of a synthetic peptide homologous to a transmembrane component of oncogenic retroviruses.	purified feline leukemia virus, uv light-inactivated feline leukemia virus, and a synthetic peptide (cks-17) homologous to a well-conserved region of the transmembrane components of several human and animal retroviruses were each studied for their effects on igg production by feline peripheral blood lymphocytes. using a reverse hemolytic plaque assay, both the viable virus and the uv-inactivated feline leukemia virus, but not the cks-17, activated b lymphocytes to secrete igg. when staphylococca ...	1987	3025858
spectrum of antiviral activity and mechanism of action of zidovudine. an overview.	zidovudine is a potent in vitro inhibitor of human immunodeficiency virus (hiv) with varying efficacy against other retroviruses. with the exception of epstein-barr virus, all non-retroviruses tested so far have been insensitive to inhibition by zidovudine. in vivo, efficacy of zidovudine was demonstrated against rauscher murine leukemia virus and feline leukemia virus. in both experimental models, infections completely resolved in animals when the drug was administered soon after infection. the ...	1988	3044082
oral use of human alpha interferon in cats.	low doses (0.5 or 5.0 u) of human alpha interferon (huifn alpha) given orally prevented the experimental development of fatal feline leukemia virus (felv)-related disease. twenty-one felv-susceptible cats were inoculated with the rickard strain of felv. cats given oral huifn alpha survived significantly (p less than 0.001) longer than untreated felv-infected cats. moreover, only 4 of 13 (30.8%) huifn alpha-treated cats developed clinical disease during the course of the study, whereas 100% of th ...	1988	3183686
evolution of the structural proteins of human immunodeficiency virus: selective constraints on nucleotide substitution.	we have estimated the frequency of synonymous (ks) and amino acid replacement nucleotide substitutions (ka) among gag and env genes of published hiv sequences. the ratio of ks to ka can be used as an indicator of the intensity of the selective constraints on the amino acid sequence of a protein. by this approach we have shown that for both gp120 and gp41, the rate of change in amino acid sequence relative to the overall rate of change in nucleotide sequence is higher than for any other protein y ...	1988	3219234
chronic idiopathic neutropenia in a cat.	persistent neutropenia (0-0.6 x 10(9) neutrophils/l) was documented during a 10-month period in a 4-year-old spayed female domestic shorthair cat that was presented for anorexia and depression. salient abnormalities detected on physical examination were fever (40.3 degrees c), dehydration, and gingivitis. the cat was neutropenic (0.5 x 10(9) neutrophils/l) and enzyme-linked immunosorbent assay (elisa) test for feline leukemia virus was negative. a bone marrow aspirate showed decreased numbers of ...	1988	3221355
parameters of production and partial characterization of feline interleukin 2.	the conditions for the production of feline interleukin 2 (il-2) from peripheral blood leukocytes (pbl) and splenocytes by concanavalin a (con a) stimulation are described. feline il-2 was quantitated by measuring dna synthesis in the murine il-2-dependent cell line, ctll-20. in addition, feline il-2 was generated for the maintenance of long-term cultures of con a-stimulated feline pbl and for biochemical characterization. finally, il-2 production was evaluated from the pbl of feline leukemia vi ...	1988	3266982
pathogenic and host range determinants of the feline aplastic anemia retrovirus.	feline leukemia virus (felv) c-sarma (or fsc) is a prototype of subgroup c felvs, which induce fatal aplastic anemia in outbred specific-pathogen-free (spf) cats. felv c isolates also possess an extended host range in vitro, including an ability, unique among felvs, to replicate in guinea pig cells. to identify the viral determinants responsible for the pathogenicity and host range of fsc we constructed a series of proviral dnas by exchanging gene fragments between fsc and felv-61e (or f6a), the ...	1988	2833751
myelofibrosis in cats with myelodysplastic syndrome and acute myelogenous leukemia.	bone marrow sections from 44 cats with myelodysplastic syndrome (mds) or acute myelogenous leukemia (aml) were graded for reticulin content using light microscopic methods. twenty-seven (61%) of the cats had slight to marked reticulin myelofibrosis. the association of myelofibrosis with possible pathogenetic factors, including megakaryocyte count, intramedullary lymphoid follicles, hemosiderin content, and felv antigenemia, was examined. no evidence was found that indicated a causal relationship ...	1988	2834859
feline haemobartonellosis: clinical, haematological and pathological studies in natural infections and the relationship to infection with feline leukaemia virus.	haemobartonella felis infection was demonstrated in 38 cats which could be divided into four groups as follows: group a, feline leukaemia virus (felv) free cats with h felis infection alone; group b, felv free cats with h felis infection and other clinical conditions; group c, felv positive cats with h felis infection but no clinical manifestation of felv related or any other intercurrent disease; and group d, felv positive cats with h felis infection and clinical manifestations of felv related ...	1988	2834861
use of a subunit feline leukemia virus vaccine in exotic cats.	three adult bengal tigers, 2 immature white tigers, and 3 adult servals were vaccinated im with three 1-ml doses of a subunit felv vaccine with dosage interval guidelines of the manufacturer. all cats had increased antibody titers to felv gp 70 capsular antigen and feline oncornavirus cell membrane-associated antigen during the vaccination trial. three weeks after the third vaccination, 7 of the 8 cats had gp70 antibody titers greater than 0.2 (optical density), and all 8 cats had feline oncorna ...	1988	2835347
effect of diethylcarbamazine on serum antibody to feline oncornavirus-associated cell membrane antigen in feline leukemia virus cats.	diethylcarbamazine (n,n-diethyl-4-methyl-1-piperazine carboxamide; dec) is a drug frequently used for prevention and treatment of the filariases. an opsonic action of dec may generate increased immune responses to microfilariae. we tested the hypothesis that dec treatment could result in higher antibody levels to other infectious agents. a retroviral animal model was studied, in light of the consideration that use of dec as an antifilarial agent could conceivably alter seroepidemiologic surveys ...	1988	2836593
a case of feline large granular lymphoma.		1988	2838677
[serological survey of feline leukemia virus infection and the outcome of antibody-positive cats].	a serological survey was carried out to examine the presence of antibodies against feline leukemia virus (felv) and feline oncornavirus-associated cell membrane antigen (focma) in 208 cat sera collected at teikyo university school of medicine. seven cats (3.4%) were positive for felv antibodies by enzyme-linked immunosorbent assay whereas no cat was positive for focma antibody by indirect membrane immunofluorescent test. anemia, leukemia and/or lymphoma formation were not observed in these felv ...	1988	2840305
effects of increasing cyclic amp or calcium on feline erythroid progenitors in vitro: normal cells are stimulated while cells from retrovirus-infected cats are suppressed.	pharmacologic modulators of cyclic 3',5'-adenosine monophosphate (camp) and calcium were added to cultures of bone marrow cells from normal cats and cats with retrovirus-induced erythroid aplasia (ea). treatment with the following reagents increased the number of erythroid progenitors (cfu-e and bfu-e) in cells from normal cats: isoproterenol, dibutyryl camp, forskolin, ro-20-1724 and a23187. however, treatment of cells collected from viremic cats not only failed to enhance cfu-e and bfu-e but i ...	1988	2840470
structure and function of endogenous feline leukemia virus long terminal repeats and adjoining regions.	the nucleotide sequence of the 5' long terminal repeat (ltr) of three independent loci (cfe-6, cfe-16, and cf-14) of endogenous feline leukemia virus (felv) dnas of the domestic cat genome was determined. the 3' ltr of the cfe-6 clone was also sequenced. the endogenous felv ltrs, which were very similar to each other in sequence and in organization of the functional domains, differed considerably from the exogenous felv ltr in the u3 region. the major differences in u3 included variations in set ...	1988	2843665
a feline model for the myelodysplastic syndrome: pre-leukaemic abnormalities caused in cats by infection with a new isolate of feline leukaemia virus (felv), ab/gm1.		1988	2844635
sir william weipers commemorative lecture. cancer and aids; the contribution of comparative medicine.		1988	2845627
fluorometric enzyme immunoassay for measurement of infectious feline leukemia virus and its neutralization.	a fluorometric enzyme immunoassay using an alkaline phosphatase-conjugated monoclonal antibody was developed to quantitate feline leukemia virus (felv) infection. monoclonal antibodies, directed against the felv structural protein p27, were conjugated with alkaline phosphatase using a modified maleimide method. the enzyme immunoassay requires only 4 days to reproducibly measure felv production instead of the 12 days required for the commonly used transformation assay using c81 cells. a linear co ...	1988	2846700
protein immunoassay based on agglutination of antibody-coated ferric oxide particles.	a novel immunoassay is described based on the agglutination by antigens of antibody-coated ferric oxide (fe2o3) particles. the procedure for attachment of antibodies to the ferric oxide particles is simple and fast. the assay was used for identification and quantification of gamma-globulin in human serum and in chromatographic fractions as well as of gp70 (an envelope protein from feline leukemia virus) in the culture medium and for identification of the thyroid-stimulating hormone (tsh).	1988	2846702
tumorigenic potential of a myc-containing strain of feline leukemia virus in vivo in domestic cats.	the oncogenic capacity of a myc-containing strain of feline leukemia virus (felv), termed lc-felv, has been examined after inoculation of the virus into neonatal kittens. like other myc-containing strains of felv, lc-felv may induce with relatively short latency, but does not necessarily induce, thymic lymphosarcoma in viremic animals. naturally occurring and experimentally induced tumors are t-cell lymphomas which contain clonally integrated lc-felv proviral dna and which cannot readily be cult ...	1988	2846887
clinical and immunologic aspects of felv-induced immunosuppression.	cats exposed to the feline leukemia virus (felv) may mount an effective immune response and eliminate the virus, develop a non-viremic, latent infection or become persistently infected and shed the virus. persistently infected cats commonly die of secondary opportunistic infections that result from felv-induced immunosuppression. the acquired immunosuppression is the most frequent and most devastating consequence of felv infection in the cat. immunosuppression is targeted primarily to the cell-m ...	1988	2847393
feline leukemia virus vaccine: new developments.		1988	2847394