Publications

lymphosarcoma and persistent feline leukemia virus infection of pet cats: a system to study responses during extracorporeal treatments.	pet cats, persistently infected with feline leukemia virus and having lymphosarcoma, were treated by extracorporeal immunoadsorption using staphylococcus aureus cowan i (which has protein a on its surface) to remove immunoglobulin g and circulating immune complexes. complete viral clearance and long-lasting tumor regression were achieved following such treatments in 9 of 16 cats. in addition, in vitro immunologic assays have been developed that are useful in the clinical evaluation of cats durin ...	1984	6086847
interaction between feline leukaemia virus subgroups in the pathogenesis of erythroid hypoplasia.	the interaction of feline leukaemia virus (felv) of subgroups a and c in the pathogenesis of erythroid hypoplasia in cats was studied. weanling kittens infected with felv-a became permanently viraemic but remained haematologically normal over a period of 36 weeks. similar kittens inoculated with felv-c, which produces erythroid hypoplasia when administered to newborn kittens, neither became viraemic nor developed the disease. however, weanling kittens inoculated with a mixture of felv-a and c be ...	1984	6088406
[detection of antigenic determinants of the major structural proteins of various mammalian type c retroviruses in the leukocytes of patients with hemoblastoses and in healthy donors by the elisa method].	using the enzyme-labelled antibodies it was shown that extracts from leukocytes of patients with leukemias and healthy donors contain antigenic determinants related to major virus protein of mammalian c type oncornaviruses ssv/ssav, baev, felv and rlv. the highest antigen activity in patients was detected in the feline leukemia (felv) system, and the least one--in the system of murine leukemia (rlv). common antigenic determinants of major virus protein of the viruses under study were detected in ...	1984	6209091
immune-mediated disorders of cats.	immune-mediated disorders in cats share many clinical and pathologic similarities with their counterparts in other species. cats, however, are unique among domestic animals owing to the involvement of feline leukemia virus. in addition, a number of other infectious organisms can produce immune-mediated sequelae--that is, fip virus, fesfv, and h. felis. therefore, the diagnostic and therapeutic aims in the management of feline immune-mediated disorders must take into account the probability of a ...	1984	6149649
method to map antigenic determinants recognized by monoclonal antibodies: localization of a determinant of virus neutralization on the feline leukemia virus envelope protein gp70.	a method is presented whereby antigenic determinants recognized by specific monoclonal antibodies can be mapped to specific sites on a protein sequence with high resolution. short dnase i-generated dna fragments encoding portions of the protein of interest are molecularly cloned into the ecori site of the beta-galactosidase gene of phage lambda charon 16 so as to obtain expression of random protein fragments as fusion proteins. the monoclonal antibody is used to screen the phage library to isola ...	1984	6203125
the immunobiology of the feline leukemia virus.		1984	6204435
[clinical aspects of infection with feline leukemia virus in cats].	the leukemia-sarcoma complex constitutes the most common group of malignancies in the cat. epizootiology of felv infections and pathogenesis, which can be divided into three stages, are described. diagnosis can be made by immunofluorescent, elisa and virus isolation techniques, as well as focma-antibody tests. symptomatology of felv related illnesses is presented. feline lymphoma can be categorized into four anatomic types: thymic, alimentary and multicentric type and true leukemia. forms, which ...	1984	6098972
remission of leukemia and loss of feline leukemia virus in cats injected with staphylococcus protein a: association with increased circulating interferon and complement-dependent cytotoxic antibody.	we have injected purified staphylococcus aureus protein a intraperitoneally into leukemic cats infected with feline leukemia virus, into cats persistently infected with feline leukemia virus but without hematologic or cytologic abnormalities, and into healthy cats without feline leukemia virus infection. pre- and post-treatment serum samples were evaluated sequentially for interferon activity and for complement-dependent cytotoxic antibody. our results indicate that serum interferon increased dr ...	1984	6208551
comparison of feline leukemia virus-infected and normal cat t-cell lines in interleukin 2-conditioned medium.	following mitogen stimulation (phytohemagglutinin or concanavalin a), feline lymphocytes were maintained in medium containing feline interleukin 2. lymphocyte lines derived from the blood of feline leukemia virus-infected cats contained cells 50 to 90% of which expressed virus antigens, but lymphocyte lines derived from uninfected cats remained virus free. leukemia virus-positive and -negative lymphocyte lines retained total dependence upon the presence of interleukin 2 for finite life spans of ...	1984	6318972
location of human t-cell leukemia virus (htlv) p19 antigen on virus-producing cells.	mouse monoclonal antibody to htlv p19 was used to locate htlv p19 on the surface of cells and virions by immunofluorescence microscopy (ifm) and immunoelectron microscopy (iem). when htlv-producing cells hut 102 (b2 clone), mt-2 and strain a were used as target cells, htlv p19 was detected on the surface of cells and virions as spots or small sectors by both ifm and iem. cells infected with animal type-c retroviruses, e.g., gibbon ape leukemia virus, simian sarcoma virus, feline leukemia virus, ...	1984	6319298
clearance of feline leukemia virus from persistently infected pet cats treated by extracorporeal immunoadsorption is correlated with an enhanced antibody response to felv gp 70.	six persistently feline leukemia virus (felv)-infected pet cats were treated by extracorporeal immunoadsorption with staphylococcus aureus cowan i (sac) to remove circulating immune complexes and immunoglobulin g (igg) from plasma. in three of these cats, the felv infection was eliminated, whereas in the other three cats the infection persisted. the amounts of peripheral blood leukocyte (pbl)-associated felv, soluble felv envelope glycoprotein (gp70) antigens in serum, and felv-gp70-specific ant ...	1984	6319496
nucleotide sequences of the envelope genes of two isolates of feline leukemia virus subgroup b.	we determined the nucleotide sequences of the envelope genes of the snyder-theilen and gardner-arnstein isolates of feline leukemia virus subgroup b. comparison of the deduced amino acid sequences of the envelope gene products revealed regions of sequence divergence, which we relate to structural features of the viral protein. we also examined nucleotide sequences within the long terminal repeats of these related isolates of feline leukemia virus subgroup b.	1984	6319767
suspected feline leukemia virus infection and pancytopenia in a western cougar.		1984	6096331
complete amino acid sequence of the basic nucleic acid binding protein of feline leukemia virus.	the complete amino acid sequence of the nucleic acid binding protein p10 of the rickard strain of feline leukemia virus (felv) has been determined. fragments obtained by enzymatic digestion were purified by reverse-phase liquid chromatography and subjected to semiautomated edman degradation. felv p10 is a basic polypeptide composed of 57 amino acids with mr = 6604. the structure of p10 is compared to the structures of other retroviral nucleic acid binding proteins, and an analysis of a highly co ...	1984	6322425
characterization of monoclonal antibodies directed against the envelope proteins of feline leukemia virus.	monoclonal antibodies directed against the feline leukemia virus (felv) envelope proteins, gp70 and p15e, were identified by radioimmunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. six of these monoclonal antibodies were specific for the gp70; two for the p15e. enzyme-linked immunosorbent assay binding assays against felv subtypes a, b, and c showed that most of the monoclonal antibodies bound to more than one subtype but have a greater affinity for subtype b. one ...	1984	6331649
viruses and bone marrow failure.		1984	6322884
inhibition of erythroid colony-forming cells by a mr 15,000 protein of feline leukemia virus.	the effects of concentrated ultraviolet-inactivated feline leukemia virus (felv), the purified mr 15,000 envelope protein (p15e) of felv, or the purified mr 27,000 structural protein (p27) of felv on feline bone marrow mononuclear cells were studied in vitro in methylcellulose cultures. whole virus and purified viral proteins were from the kawakami-theilen isolate of felv, which induces erythroid aplasia in cats. bone marrow mononuclear cells from felv-negative young adult cats were preincubated ...	1984	6322979
a new package for an old oncogene.		1984	6325919
transduction and rearrangement of the myc gene by feline leukaemia virus in naturally occurring t-cell leukaemias.	evidence of myc gene transduction by feline leukaemia virus in several spontaneous lymphoid tumours of cats suggests that recombinant viruses carrying oncogenes may be much more involved in oncogenesis in natural conditions than previously recognized.	1984	6325920
isolation of a feline leukaemia provirus containing the oncogene myc from a feline lymphosarcoma.	the molecular mechanism by which feline leukaemia virus (felv) induces lymphoid malignancy in domestic cats is largely unknown. using the insertional activation model of c-myc by avian leukosis virus in the induction of bursal lymphoma in chickens, we have now characterized the c-myc locus in feline tissues and investigated the possibility that felv may also insert within feline c-myc. we used the 1.5 kilobase (kb) psti fragment of mc29 v-myc in southern blot analysis to characterize the structu ...	1984	6325921
viral transduction of c-myc gene in naturally occurring feline leukaemias.	feline leukaemia virus (felv) is epidemiologically associated with induction of the majority of lymphoid tumours of the domestic cat. however, about one-third of these tumours are devoid of exogenous virus or show evidence of virus integration only after tumour outgrowth. to help define the genetic mechanisms of feline lymphomagenesis we have explored here the possibility that cellular oncogenes (c-onc genes) are rearranged in tumour cell dna. of 16 felv-positive t-cell tumours among 31 naturall ...	1984	6325922
nucleotide sequence of the gag gene and gag-pol junction of feline leukemia virus.	the nucleotide sequence of the gag gene of feline leukemia virus and its flanking sequences were determined and compared with the corresponding sequences of two strains of feline sarcoma virus and with that of the moloney strain of murine leukemia virus. a high degree of nucleotide sequence homology between the feline leukemia virus and murine leukemia virus gag genes was observed, suggesting that retroviruses of domestic cats and laboratory mice have a common, proximal evolutionary progenitor. ...	1984	6328019
appearance of cytotoxic antibody to viral gp70 on feline lymphoma cells (fl-74) in cats during ex vivo immunoadsorption therapy: quantitation, characterization, and association with remission of disease and disappearance of viremia.	fifty cats with feline leukemia virus (felv) infection and leukemia-lymphoma complex were treated by ex vivo immunoadsorption with staphylococcus protein a-bound filters. most cats responded to therapy. twelve showed tumor regression, including disappearance of tumor cells, but died later of other complications. three have had long-term remission of more than 1 year and remain healthy. a consistent finding in these three cats was the appearance during treatment of a complement-dependent cytotoxi ...	1984	6328520
infection with feline leukemia virus associated with induction of humoral response to a normal cell protein.	selected populations of cats that were naturally exposed to the feline leukemia virus (felv) were found to have humoral antibodies to a normal cell protein designated ncp105. earlier studies revealed that cats exposed to felv often had serum antibodies to the feline oncornavirus-associated cell membrane (focma) as well as to a feline sarcoma virus (fesv) -specific transforming protein designated gag-fes. cats with no history of exposure to felv or fesv lacked antibodies to all three antigens: nc ...	1984	6329486
transcriptional control of the bovine leukemia virus genome: role and characterization of a non-immunoglobulin plasma protein from bovine leukemia virus-infected cattle.	using cloned bovine leukemia virus (blv) dna as a probe in the dot blot hybridization technique, we demonstrated that the expression of the blv genome in infected lymphocytes is blocked in vivo at the transcriptional level. this blocking effect is due to a non-immunoglobulin protein present in the plasma but not in the serum of blv-infected cattle. the plasma blv-blocking protein also blocks the expression of the blv genome in fibroblast cells of bovine and nonbovine origin infected with blv in ...	1984	6321796
indirect leukocyte migration inhibition in breast cancer and benign breast disease patients by mouse mammary tumor virus grown in feline kidney cells.	indirect migration inhibition assays were performed with normal and mammary tumor-bearing c3h/hen mice and patients with breast disease to assess cellular immunity against three different mouse mammary tumor virus (mtv) preparations grown in feline kidney cell cultures and against a mouse-derived mtv preparation. mtv obtained after passage through feline kidney cells and the mouse-derived mtv were capable of eliciting macrophage migration inhibitory factor production by mouse spleen cells obtain ...	1984	6321840
biological behavior of tumors and associated retroviremia in cats inoculated with snyder-theilen fibrosarcoma virus and the phenomenon of tumor recurrence after primary regression.	the fate of tumors and associated retroviremia was studied in 111 cats infected with the snyder-theilen strain of feline sarcoma virus (fesv). tumors appeared at the site of inoculation within 7 to 10 days. a retroviremia, due mainly to the associated feline leukemia virus helper virus (felv-helper), developed at the same time as tumors. of the cats, 44 developed progressively growing tumors and therefore had to be killed, and 67 developed tumors that regressed. there was a strong correlation be ...	1984	6319286
[infection with feline leukemia virus: immunology and serodiagnosis as the basis for control. 1].		1984	6324337
[infection with feline leukemia virus: immunology and serodiagnosis as a basis for the prevention of infection. 2].		1984	6324338
nucleotide sequence of the feline retroviral oncogene v-fms shows unexpected homology with oncogenes encoding tyrosine-specific protein kinases.	the nucleotide sequence encoding the transforming polyprotein of the mcdonough strain of feline sarcoma virus was determined. this sequence includes 231 nucleotides specifying a leader peptide, 1,377 nucleotides encoding most of the feline leukemia virus-derived gag gene, and 2,969 nucleotides representing the viral transforming gene v-fms. a single open reading frame was predicted to encode a fusion polyprotein of 160,000 daltons (p160gag-fms). fourteen potential sites for glycosylation were pr ...	1984	6582485
multicentric fibrosarcoma in a cat and a review of the literature.	a case of multicentric fibrosarcoma in a ten month old domestic short-haired cat is presented and discussed. tumor tissue was found to involve the right distal forepaw, right shoulder area and a popliteal lymph node. this anaplastic neoplasm was concentrated primarily in subcutaneous tissues but also extended to muscle, bone and lung. the cat was found to be positive for feline leukemia virus by the elisa test. based on these findings, it is likely that the lesions in this case result from an in ...	1984	17422403
susceptibility of cats, sheep, and swine to a rabbit isolate of encephalitozoon cuniculi.	newborn cats, pigs, and sheep (3 to 14 days old) and postweanling cats (2.5 months old) that had been inoculated with gardner feline sarcoma virus and feline leukemia virus at 10 days of age were infected experimentally with a rabbit isolate of the mammalian protozoan parasite encephalitozoon cuniculi. infection occurred in all cats and in some sheep, but was questionable in pigs. brain and kidney were the 2 major target organs in cats. the lesions were compatible with, but less severe than, tho ...	1985	3923875
polyclonal induction of immunoglobulin synthesis by feline leukocytes as identified in a reverse hemolytic plaque assay.	optimal conditions of culture and assay for identification of feline immunoglobulin-secreting mononuclear cells were determined for the staphylococcal protein a-reverse hemolytic plaque assay (spa-rhpa). hemolytic plaques were most distinct and numerous when peripheral blood mononuclear cells were stimulated with 6.9 micrograms/ml pokeweed mitogen for 7 days. immunoglobulin-secreting cells were identified morphologically within a zone of hemolysis utilizing a 1:5 dilution of rabbit anti-cat igg ...	1985	3894522
subunit vaccines against exogenous retroviruses: overview and perspectives.	vaccines prepared from purified viral envelope complexes are effective against certain animal model tumors induced by exogenous retroviruses. related viruses have recently been isolated from humans and obviously cause adult t-cell leukemia and the acquired immunodeficiency syndrome. knowledge accumulated in experiments with subunit vaccines against animal retroviruses could help to develop immunopreventive regimens against human retroviruses.	1985	2410114
molecular analysis of several classes of endogenous feline leukemia virus elements.	five recombinant dna clones of endogenous feline leukemia virus-related dna sequences were isolated by screening a lambda phage genomic library of cat placental dna with a probe specific to the gag-pol region of infectious feline leukemia virus. the clones containing retroviral long terminal repeat-like sequences demonstrated the existence of different size classes of endogenous elements in the cat genome, including those of nearly full length in which the gag region is heterogeneous but all of ...	1985	2415715
pelger-huët anomaly in cats.	pelger-huët anomaly was diagnosed in a young male cat on the basis of persistent nuclear hyposegmentation of blood granulocytes, absence of clinical disease or feline leukemia virus infection, and demonstration of genetic transmission of the anomaly. neutrophils, eosinophils, basophils, and monocytes had significantly less nuclear segmentation when compared to similar leukocyte types from a control cat. on smears of bone marrow, megakaryocytes also appeared hyposegmented. a test mating with an u ...	1985	4035941
feline leukemia virus-and feline sarcoma virus-related polypeptides released by virus producer and nonproducer cells.	polypeptides specific for feline leukemia virus (felv) have been identified in the media of cells that produce felv as well as in nonproducer cells transformed by feline sarcoma viruses (fesv). cat fibroblasts that were persistently infected with felv release the major virus envelope glycoprotein, whereas cultured cat lymphoma cells shed both glycopeptides related to the virus core gene (gag) and glycopeptides related to the virus envelope gene (env). mink cells and cat cells transformed by fesv ...	1985	3002564
translational readthrough of an amber termination codon during synthesis of feline leukemia virus protease.	feline leukemia virus contains a protease which apparently has the same specificity as murine leukemia virus protease. it cleaves in vitro the pr65gag of gazdar-mouse sarcoma virus into the constituent p15, p12, p30, and p10 proteins. we purified the protease and determined its nh2-terminal amino acid sequence (the first 15 residues). alignment of this amino acid sequence with the nucleotide sequence (i. laprevotte, a. hampe, c. h. sherr, and f. galibert, j. virol. 50:884-894, 1984) reveals that ...	1985	2991607
killer cells of feline leukemia virus- and feline sarcoma virus-infected transformed cells: the role of nk, adcc, and in vitro generated cytotoxic cells.	feline white blood cells (wbc) manifested a primary in vitro mixed lymphocyte tumor cell culture (mltc) proliferative response to feline leukemia virus-feline sarcoma virus (felv-fesv)-infected transformed target cells, which reached a peak at day 15. furthermore, primary in vitro mltc cultures generated cytotoxic killer cells capable of killing a variety of targets in non-major histocompatibility gene complex restricted fashion, and effector cells were capable of killing targets introduced repe ...	1985	2992811
blocking (suppressor) factors, immune complexes, and extracorporeal immunoadsorption in tumor immunity.		1985	2992879
feline leukaemia virus.		1985	2993169
rheumatoid factors in natural retrovirus infections of the cat and cattle.	the occurrence of igm-rheumatoid factors (rfs) was investigated in natural retrovirus infection of cats with feline leukaemia virus and of cattle with bovine leukaemia virus. igm-rfs of polyclonal character were detected. no significant differences were observed between the amounts of igm-rfs in the retrovirus-infected animals and their respective controls.	1985	2993377
stimulation of a cell-mediated cytotoxic response to felv-induced t cell lymphomas in the cat.	nonspecific cell-mediated cytotoxicity was examined in the peripheral blood and spleens of normal and vaccinia virus-infected adult domestic cats. natural cytotoxic (nc)-like cells, as measured by lysis of vaccinia- or hsv-infected, adherent cat tongue cells, were found in both the spleen and peripheral blood of normal, nonimmune cats. cytotoxicity was expressed in a 16-hr assay but not in a 4-hr assay. natural killer (nk)-like cells, as measured by lysis of an felv-induced lymphoid tumor cell l ...	1985	2993416
epizootiologic survey of feline leukemia virus in south-kyushu area.		1985	2995717
quantitation of specific antibodies bound to feline leukemia virus in the plasma of pet cats.	a method is described for determining levels of circulating immune complexes (cic) composed of feline leukemia virus (felv) antigens and corresponding antibodies in plasma of persistently-infected pet cats. the procedure is based on the ability of high-titered heterologous anti-felv serum to chase cat anti-felv igg from dissociated cic by successfully competing for binding of free antigen. the eluted cat antibody is then collected and quantitated. in a study of cats in the process of clearing pe ...	1985	2995795
inhibition of lymphocyte proliferation by a synthetic peptide homologous to retroviral envelope proteins.	the retroviral transmembrane envelope protein p15e is immunosuppressive in that it inhibits immune responses of lymphocytes, monocytes, and macrophages. a region of p15e has been conserved among murine and feline retroviruses; a homologous region is also found in the transmembrane envelope proteins of the human retroviruses htlv-i and htlv-ii and in a putative envelope protein encoded by an endogenous c-type human retroviral dna. a peptide (cks-17) was synthesized to correspond to this region of ...	1985	2996136
the reversal of feline retroviral-induced suppression of lymphocyte con a receptor mobility by indomethacin and pge2.	ultraviolet light-inactivated feline leukemia virus (felv) and its 15,000 dalton envelope protein (p15e) inhibited concanavalin a receptor motility of feline peripheral lymphocytes (pbl). in contrast, the virus had no effect on immunoglobulin capping of feline pbl. the inhibitory action of felv and felv p15e was reversed by the addition of indomethacin. the indomethacin effect was titratable and gave significant reversal between 1 x 10(-5) and 1 x 10(-10) m. the indomethacin inhibition of the pr ...	1985	2999519
the prospects for and pathways toward a vaccine for aids.	this article reviews prospects for a vaccine for acquired immunodeficiency syndrome (aids), considered the only certain barrier to further spread of the disease. the development of an effective vaccine against another retrovirus, feline leukemia virus, suggests the possibility that a retrovirus vaccine for humans might work. however, vaccine production depends on the ability to manufacture large quantities of a safe antigen that stimulates protective immunity when it is injected into humans. ...	1985	2999596
chronic eosinophilic leukaemia in blast crisis in a cat negative for feline leukaemia virus.		1985	3000060
duration of the latent state in feline leukaemia virus infections.		1985	3000061
[aids--general characteristics and new clues in the studies of etiopathogenesis of the syndrome--the role of htlv].		1985	3000090
reversal of feline retroviral suppression by indomethacin.	the immunosuppressive effect of feline leukemia virus (felv) and its 15,000 dalton envelope protein (p15e) were studied to determine if the mechanism of action was due to an increase in prostaglandin production. we examined the effects of exogenous pge1 and pge2 on the normal con a response of feline peripheral blood lymphocytes (pbl) and found them to be inhibitory. the addition of the cyclooxygenase inhibitor indomethacin to cells incubated with felv or felv p15e and con a completely abrogated ...	1985	3001436
suppression of gamma interferon production by inactivated feline leukemia virus.	supernatants from cultures of normal feline lymphocytes stimulated with staphylococcus enterotoxin a showed antiviral activity, characterized as a gamma-like interferon. with the addition of inactivated feline leukemia virus, markedly less interferon was produced. the reduction in interferon production was not attributable to lowered lymphocyte viability or reduced mitogenic properties of staphylococcus enterotoxin a and appears to be a direct retroviral effect. this finding may reflect clinical ...	1985	2983424
molecular cloning of the feline c-fes proto-oncogene and construction of a chimeric transforming gene.	the feline c-fes proto-oncogene, different parts of which were captured in feline leukemia virus (felv) to generate the transforming genes (v-fes) of the gardner-arnstein (ga) strain of feline sarcoma virus (fesv) and the snyder-theilen strain (st) of fesv, was cloned and its genetic organization determined. southern blot analysis revealed that the c-fes genetic sequences were distributed discontinuously and colinearly with the v-fes transforming gene over a dna region of around 12.0 kb. using c ...	1985	2993104
feline glucose-6-phosphate dehydrogenase cellular mosaicism. application to the study of retrovirus-induced pure red cell aplasia.	neoplasms result from the uncontrolled proliferation of abnormal or transformed cells. the early stages of this process are difficult to study because of the lack of sensitive and specific markers of clonal evolution in an experimental system. we have developed a cat model using cellular mosaicism for glucose-6-phosphate dehydrogenase (g-6-pd). our findings confirm that the structural locus for feline g-6-pd is on the x-chromosome and demonstrate that it is randomly inactivated in somatic cells. ...	1985	2981248
haemadsorption and haemagglutination by feline leukaemia viruses.	the interaction of feline leukaemia viruses (felv) with erythrocytes was investigated. haemadsorption (had) was observed on the surface of feline embryonic fibroblast cells infected with felv. had was detected in various degrees when cat, hamster or horse erythrocytes were incubated with cells infected with viruses of subgroup c (felv-c) and on cells infected with some felv subgroup a viruses (felv-a), but not on cells infected with felv subgroup b viruses (felv-b). had of sheep erythrocytes was ...	1985	2981974
isolation from cats of an endogenous type c virus with a novel envelope glycoprotein.	a search for variant endogenous cat viruses led to a novel isolate. although the major envelope glycoprotein of this virus was similar in size to that of an rd-114-like virus that was coisolated, it was unrelated to rd-114 or feline leukemia virus by immunological and biological criteria. this degree of dissimilarity suggests a different evolutionary progenitor from that for the rd-114 and feline leukemia virus viral envelopes. the novel virus did, however, code for gag gene polypeptides which a ...	1985	2983093
clinicopathologic responses in cats with feline leukemia virus-associated leukemia-lymphoma treated with staphylococcal protein a.	purified protein a from staphylococcus aureus cowan i was injected intraperitoneally or was incorporated in filters ex vivo through which plasma from cats with feline leukemia virus (felv)-associated leukemia-lymphoma was passed. before treatment, 65% of the felv-infected cats were anemic, and 70% were thrombocytopenic. concomitant infections, or immune-mediated disease, was common. during treatment 50% of the cats with felv-associated disease improved objectively with normal posttreatment hemat ...	1985	2983560
antitumor activity of protein a administered intravenously to pet cats with leukemia or lymphosarcoma.	extracorporeal immunoadsorption with protein a (spa) containing staphylococcus aureus cowan i (sac) has previously been shown to induce an antitumor and antiviral response in some feline leukemia virus (felv)-infected, lymphosarcoma (lsa) cats. however, the mechanism by which this response is induced is unknown. since it is possible that spa dissociates from the sac column during treatment, and that intravenous infusion of spa could be a more efficacious form of treatment than extracorporeal imm ...	1985	2983866
retrovirus-mediated immunosuppression. i. felv-uv and specific felv proteins alter t lymphocyte behavior by inducing hyporesponsiveness to lymphokines.	murine splenocytes were used to study the in vitro immunosuppressive effects of uv-inactivated feline leukemia virus (felv-uv). felv-uv blocks both alloantigen (dba/2)-induced and con a-induced proliferation of c57bl/6 splenocytes in a dose-dependent manner. furthermore, c57bl/6 anti-dba/2 mixed lymphocyte cultures containing felv-uv fail to develop detectable dba/2-specific cytolytic activity, although felv-uv has no effect on the cytolytic activity of preformed c57bl/6 anti-dba/2 cytolytic t c ...	1985	2984289
ultrastructural morphology of leukemic cells in the cat.	transmission and scanning electron microscopic characteristics of leukemic cells from eight cats with spontaneous leukemia are described. nuclear blebs, myelin figures, cytoplasmic microfibrils and c-type virus were seen more frequently in leukemic cells. surface ridges and ruffles seen with the scanning electron microscopy were helpful in distinguishing myelogenous from lymphogenous leukemia.	1985	2984829
influence of antibody infusion on pathogenesis of experimental feline leukemia virus infection.	for examination of the influence of antibody on the pathogenesis of feline leukemia virus (felv) infection, 12 weanling specific-pathogen-free cats were inoculated with isolates of felv and were treated beginning at 7, 19, 21, 24, 34, or 49 days post inoculation (dpi) with feline anti-felv hyperimmune serum (10 infusions, 37 mg globulin/kg each at 48-hr intervals). anti-felv serum infusion initiated at 7 dpi prevented the onset of hematopoietic cell infection and viremia. antibody treatment init ...	1985	2985857
serologic evaluation of vaccinated american river otters.	the oklahoma department of wildlife conservation acquired 20 american river otters (lutra canadensis) between 1984 and 1985 for reintroduction into oklahoma waterways. in 1985, 10 otters were evaluated for serum antibody titers after vaccination with canine distemper virus, canine adenovirus type 2, canine parvovirus (cpv), feline panleukopenia virus (fpv), feline rhinotracheitis virus (frv), and feline calicivirus. prevaccination serum-virus neutralization (svn) antibody to feline rhinotracheit ...	1985	3001000
feline leukaemia viruses: molecular biology and pathogenesis.	the feline leukaemia virus (felv) group represents one of the most important viral pathogens of the domestic cat. in addition, this virus - host system is one of the major experimental models for retroviral pathogenesis. under natural conditions, the virus is horizontally transmitted through the cat population. the outcome of infection depends on a variety of factors including the virus does encountered and the age and immune status of the host. felvs can establish persistent infection, either o ...	1985	2986521
retrovirus-mediated immunosuppression. ii. felv-uv alters in vitro murine t lymphocyte behavior by reversibly impairing lymphokine secretion.	murine splenocytes and cloned murine t cells were used to study the in vitro immunosuppressive effects of uv-inactivated feline leukemia virus (felv-uv) on lymphokine secretion. felv-uv can significantly depress the accumulation of il 2 in cultures of con a-stimulated c57bl/6 splenocytes and in cultures containing the alloreactive helper t cell clone b6d/2-2m plus con a. inhibition of lymphokine accumulation in these cultures could not be attributed to absorption or inactivation of il 2 by the f ...	1985	2987350
induction of protective immune response in cats by vaccination with feline leukemia virus iscom.	an effective candidate subunit vaccine consisting of the gp 70/85 of feline leukemia virus (felv) was prepared by using the immunostimulating complex (iscom) method for the presentation of membrane proteins of enveloped viruses. two 32-wk-old specific pathogen-free (spf) cats were immunized with a felv iscom vaccine prepared from the supernatant fluid of the fl74 tumor cell line without adjuvant. both cats developed felv serum antibodies, as measured in an enzyme-linked immunosorbent assay (elis ...	1985	2987351
effects of cobra venom factor treatment on latent feline leukemia virus infection.	the role of the complement system in containment of feline leukemia virus infection was studied by cobra venom factor treatment of feline leukemia virus-immune cats. one to three weeks after cobra venom factor treatment, an increase in viral antigen in marrow myelomonocytic cells and circulating immune complexes was noted. prevention of reactivation of feline leukemia virus infection may in part depend on an intact complement system.	1985	2987539
retroviral-associated eosinophilic leukemia in the cat.	fourteen specific-pathogen-free cats were inoculated with a putative env gene recombinant feline retrovirus, pr8. an isolate of the rickard strain of feline leukemia virus (felv-r), pr8, has the properties of both an exogenous (felv-r) and an endogenous (xenotropic) feline retrovirus (rd-114). twelve of the pr8-inoculated cats developed viremia; 2 of the 12 cats developed eosinophilia, with 1 being diagnosed with eosinophilic leukemia and the other with extreme eosinophilic hyperplasia. eosinoph ...	1985	2988377
the promoter of the long terminal repeat of feline leukemia virus is effective for expression of a mouse h-2 histocompatibility gene in mouse and human cells.	dna-mediated gene transfer techniques have been used to study the effectiveness of a novel construction involving the feline leukemia virus long terminal repeat (felv ltr) for expressing the mouse h-2 ld gene in mouse and human cells. in this construction, the transcription initiation (promoter) and termination (polyadenylation) functions of the felv ltr have been split by insertion of a promoterless h-2 gene between them. an s1 nuclease assay has been developed that makes it possible to measure ...	1985	2989102
nucleotide sequence of a transduced myc gene from a defective feline leukemia provirus.	the nucleotide sequence of a feline v-myc gene and feline leukemia virus (felv) flanking regions was determined. both the nucleotide and predicted amino acid sequences are very similar to the murine and human c-myc genes (ca. 90% identity). the entire c-myc coding sequence is represented in feline v-myc and replaces portions of the gag and env genes and the entire pol gene. the coding sequence is in phase with the gag gene reading frame; v-myc, therefore, appears to be expressed as a gag-myc fus ...	1985	2989554
animal models: lessons from feline and bovine leukaemia virus infections.		1985	2989623
hypercalcemia in cats with feline-leukemia-virus-associated leukemia-lymphoma.	three cases of hypercalcemia were recognized among 11 cats presenting with leukemia-lymphoma for ex vivo immunoadsorption therapy using staphylococcal protein-a-coated filters. in addition, the initial mean serum calcium concentration of cats with leukemia-lymphoma was significantly higher (p less than 0.005) than that of healthy control cats or feline-leukemia-virus-infected cats without malignancy. during immunotherapy of the hypercalcemic cats, objective reduction in the extent of the maligna ...	1985	2990654
retroviruses associated with leukemia and ablative syndromes in animals and in human beings.	t-lymphotropic retroviruses of cats cause lymphopenia and immunosuppression and represent the major cause of death in that species. similarly htlv-i which is t4 tropic is associated with an increased risk for development of infectious disease in regions where the virus is endemic. since htlv-i is also believed to be transmitted by blood and by sexual intercourse we considered the possibility that a variant form of htlv might cause aids. the identification of cross-reactive antibodies to htlv-i-m ...	1985	2990682
possible immunoenhancement of persistent viremia by feline leukemia virus envelope glycoprotein vaccines in challenge-exposure situations where whole inactivated virus vaccines were protective.	kittens immunized with purified native felv-gp70 or -gp85 envelope proteins developed elisa, but not virus neutralizing, antibodies in their serum to both whole felv and felv-gp70. kittens vaccinated with envelope proteins and infected with feline sarcoma virus (fesv) developed smaller tumors than nonvaccinates, but a greater incidence of persistent retroviremia. similarly, felv-gp70 and -gp85 vaccinated kittens were more apt to become persistently retroviremic following virulent felv challenge ...	1986	3008409
feline leukemia vaccine: efficacy, contents and probable mechanism.	an effective subunit vaccine against feline leukemia virus infection and related diseases has been developed. the source of the vaccine immunogen is feline retrovirus persistently infected cells that continuously synthesize and shed virus polypeptides. western blot analysis identifies felv-gp70, p27, p15, p12, and p10 in the subunit vaccine preparation. cats immunized with the vaccine developed antibodies to a 70,000 mw protein of the vaccine that seems to be distinct from, but related to the fe ...	1986	3008410
prevalence of feline leukemia virus infection among adult cats at an animal control center: association of viremia with phenotype and season.	the overall frequency of feline leukemia virus infection among 555 cats tested from the hillsborough county florida animal control facility, using a commercial enzyme-linked immunosorbent assay, was 9.4%. among male cats, the frequency was 13.8%, which was statistically higher (p = 0.003) than that for females (5.9%). there was no statistical evidence to associate frequency of viral infection with hair length or coloration. there was an association with color distribution. the frequency of viral ...	1986	3008609
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
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
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
[occurrence of feline leukemia in kosice].		1986	3017266
feline leukemia virus-induced thrombocytopenia and macrothrombocytosis in cats.	the kawakami-theilen strain of feline leukemia virus (felv-kt), an exogenous anemia-inducing retrovirus, induced significant macrothrombocytosis and thrombocytopenia during acute infections of cats. the geometric mean platelet volumes of both freshly isolated fixed platelets and ethylenediamine tetraacetic acid-sphered platelets from infected cats were increased, but the ratio of fresh-fixed to ethylenediamine tetraacetic acid-sphered platelet volumes, an estimate of ethylenediamine tetraacetic ...	1986	3004002
flow cytometric and radioisotopic determinations of platelet survival time in normal cats and feline leukemia virus-infected cats.	this study demonstrates the potential usefulness of a flow cytometric technique to measure platelet survival time in cats utilizing autologous platelets labeled in vitro with fluorescein isothiocyanate (fitc). when compared with a 51cr method, no significant differences in estimated survival times were found. both the 51cr and fitc-labeling procedures induced similar changes in platelet shape and collagen-induced aggregation. platelets labeled with fitc had significantly greater volumes compared ...	1986	3004846
evaluating the reliability of diagnostic test results.		1986	3005202
[feline leukemia: current status regarding prevention].	particularly as a result of the increasing popularity of keeping cats as pets, feline leukaemia constituted a risk to the cat population for many years; it was uncontrollable because of its insidious course and the spread of the virus, which passed unnoticed. during the past decade, diagnostic laboratory tests resulted in progress in the control of the infection for the first time. dissemination of the virus could then at least be checked to some extent. prevention by vaccination did not appear ...	1986	3006279
a feline retrovirus induced t-lymphoblastoid cell-line that produces an atypical alpha type of interferon.	a cell-line, designated lsa-1, was derived from a thymic lymphosarcoma that occurred in a cat with experimentally induced feline leukemia virus (felv) infection. lsa-1 cells possessed surface receptors and antigens of normal t-lymphocytes, but were unresponsive to interleukin-2 stimulation. the lsa cell-line was found to constitutively produce and release an interferon into the culture supernatants. production of this interferon was enhanced in certain clones of the original lsa-1 cell lines. th ...	1986	3006326
multilineage, non-species specific hematopoietic growth factor(s) elaborated by a feline fibroblast cell line: enhancement by virus infection.	in studies designed to determine the role of feline leukemia virus (felv) in the pathogenesis of marrow failure in the cat, we tested medium conditioned by uninfected and felv-infected feline embryonic fibroblasts (fea) for its effect on hematopoietic colony growth in culture. as opposed to an inhibitory effect, we found that the conditioned medium (cm) from fea or fea/felv increased the in vitro growth of multiple hematopoietic progenitor cell types including erythroid burst-forming cells (bfu- ...	1986	3007539
felv-induced feline acquired immune deficiency syndrome. a model for human aids.		1986	3008168
evaluation of terminal deoxynucleotidyl transferase expression in bone marrow of clinically normal and feline leukemia virus-exposed cats.	bone marrow cells from 8 specific-pathogen-free and 11 feline leukemia virus-exposed cats were examined for the expression of the nuclear antigen terminal deoxynucleotidyl transferase (tdt). using a standard indirect immunofluorescence technique, feline leukemia-exposed cats had increased expression of tdt in bone marrow aspirates (2.0% to 29.0%) when compared with that in bone marrow cells from specific-pathogen-free cats (2.5% to 6.0%). seemingly, tdt can be used as an antigenic marker in leuk ...	1986	3008612
changing manifestations of a chronic feline haematopoietic proliferative disease during immunotherapy with staphylococcal protein a.	a cat with feline leukaemia virus-associated malignant disease was treated by ex vivo immunoadsorption using staphylococcal protein a coated filters. during the 12-week course of treatment, the morphological manifestations of the haematopoietic disease showed a progressive transition from erythroid to myeloerythroid to myeloid predominance, and the disease was preceded by and associated initially and terminally with a blast transformation of lymphoblastic morphology. necropsy revealed massive me ...	1986	3009564
nucleotide sequences of a feline leukemia virus subgroup a envelope gene and long terminal repeat and evidence for the recombinational origin of subgroup b viruses.	molecular clones of the subgroup a feline leukemia virus felv-a/glasgow-1 have been obtained. nucleotide sequence analysis of the 3' end of the proviral genome and comparison with the published sequence of felv-b/gardner-arnstein showed that the most extensive differences are located within the 5' domain of the env gene. within this domain, several divergent regions of env are separated by more conserved segments. the 3' end of env is highly conserved, with only a single amino acid coding differ ...	1986	3009890
recombinant dna approaches to feline leukemia virus immunization.	we have utilized 2 recombinant dna strategies for immunization against felv in cats: (a) modified live virus was attenuated by mutation and recombination, and (b) an immunogen, consisting of subunit envelope protein, was prepared in genetically engineered yeast. results indicated that the genetically manipulated live virus preparations were not protective against felv challenge because they were either not attenuated in virulence or were not sufficiently antigenic. immunization with yeast-synthe ...	1986	3010935
use of tears for diagnosis of feline leukemia virus infection.	a comparison was made of the use of serum, tears, and saliva for the detection of feline leukemia virus (felv) infection in cats. cotton swabs were used to collect saliva, and tear-test strips were used to collect tears. specimens were analyzed by a commercially available elisa. using a 10- to 15-minute specimen incubation period, felv was detected in 70% of the saliva specimens and in 73% of the tear specimens from viremic (serum-positive) cats. feline leukemia virus antigen was not detected in ...	1986	3011717
transmission of feline leukaemia virus in the milk of a non-viraemic cat.	the possibility of the transmission of feline leukaemia virus (felv) from latently infected cats was studied. five female cats with latent infections were examined for evidence of transmission of the virus to their kittens. one of the cats infected members of four consecutive litters of kittens which subsequently became persistently viraemic and transmitted the virus to other susceptible kittens by contact. shortly after birth its kittens were apparently felv-free since neither viral antigen nor ...	1986	3012849
feline leukaemia virus antigen in cats from beirut, lebanon.		1986	3012854
post-exposure treatment with monoclonal antibodies in a retrovirus system: failure to protect cats against feline leukemia virus infection with virus neutralizing monoclonal antibodies.	we have attempted to protect kittens against oronasal infection with felv (strain a/glasgow-1) by treatment with a mixture of two virus-neutralizing (vn) mabs (iggl, k) directed against the same epitope on the viral glycoprotein gp70. ten spf 9-week-old kittens were infected on day 0 with 10(6) ffu felv and subsequently inoculated i.m. with mabs every 2 days over a 20-day period at different times after infection. the results clearly show that no protection was achieved. it is unlikely that the ...	1986	3013786
[the feline leukemia virus vaccine leukocell: reference for use].		1986	3014644