Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| lymphotropic retroviruses of animals and man. | 1988 | 2847502 | |
| feline leukemia/sarcoma viruses and immunodeficiency. | 1988 | 2847504 | |
| antithymocyte globulin treatment of retrovirus-induced feline erythroid aplasia: in vivo and in vitro studies. | the kawakami-theilen strain of feline leukemia virus (felv-kt) was used experimentally to produce erythroid aplasia in cats. the in vivo effects of goat anti-feline-thymocyte globulin (atg) on hematopoiesis were investigated in felv-negative normal and felv-positive anemic cats. treatment was initiated in anemic cats between 4 and 6 weeks postinoculation (pi) when erythroid progenitors were reduced to 10% of normal levels. during the first 2 weeks of treatment, atg significantly increased the nu ... | 1988 | 2847891 |
| [critical application of the cite-felv test, a new concept elisa for the study of feline leukemia virus in blood samples from cats]. | 1988 | 2848490 | |
| feline immunodeficiency syndrome--a comparison between feline t-lymphotropic lentivirus and feline leukemia virus. | a feline t-lymphotrophic lentvirus (ftlv) has recently been isolated from a domestic cat free of feline leukemia virus (felv). this virus is distinct from felv (an oncornavirus), although they share a common denominator, namely, the ability to cause immunosuppression and induce lymphadenopathy and anemia. their differences can be revealed by examining the following: the metal requirement for reverse transcriptase activity, the antigenic comparison by western blot analysis, the different suscepti ... | 1988 | 2848998 |
| activation of the feline c-fms proto-oncogene: multiple alterations are required to generate a fully transformed phenotype. | the v-fms oncogene is capable of producing tumors in vivo and transforming cells in culture; in contrast, the c-fms proto-oncogene is nontransforming. in this report we present the complete nucleotide sequence of a feline c-fms cdna, the progenitor of the v-fms oncogene. comparison of this sequence with that of v-fms shows that the proteins encoded by these two genes differ by nine amino acid substitutions and the replacement of 50 c-terminal amino acids present in c-fms by 11 unrelated residues ... | 1988 | 2849512 |
| igg-fc-receptor positive and negative t cells from feline leukemia virus-infected cats. | 1988 | 2850387 | |
| suppression of feline bone marrow fibroblast colony-forming units by feline leukemia virus. | bone marrow fibroblast colony-forming units (cfu-f) were evaluated in cats experimentally infected with feline leukemia virus (felv). cats that developed persistent viral infection and anemia (progressor cats) had a progressive decrease in the number of cfu-f at 2, 4, 6, 8, and 10 weeks after inoculation with felv. this suppression of cfu-f number in progressor cats ranged from 16 to 44% of the preinoculation cfu-f value. cats that did not develop persistent viral infection or anemia (regressor ... | 1988 | 2831764 |
| effect of continuous oral diethylcarbamazine treatment on lymphocyte counts of feline leukemia virus-infected cats. | in previous studies, administration of diethylcarbamazine (dec) resulted in increased serum antibody titers to feline oncornavirus-associated cell membrane antigen (focma) in cats infected with feline leukemia virus (felv). felv infection of cats frequently results in immunosuppression associated with lymphopenia. the present investigation demonstrated that chronic administration of dec prevented or delayed severe lymphopenia in two felv-infected offspring of an felv-infected queen as compared t ... | 1988 | 2855080 |
| receptor-mediated leukaemogenesis: hypothesis revisited. | the discovery of the first example of retroviral transduction of an immunological effector molecule has led us to reconsider the possible importance of cell surface receptors of the immune system in leukaemia development. antigen receptors on lymphoid cells not only bind external ligands but are crucial in the control of cellular proliferation. the concept of autocrine stimulation in oncogenesis is already well established and we see no reason to exclude the possibility of analogous mechanism op ... | 1988 | 2855466 |
| colony stimulating factor-1 induced growth stimulation of v-fms transformed fibroblasts. | the v-fms oncogene, which is capable of transforming fibroblasts, was derived by recombination of a feline leukemia virus with a cellular gene (c-fms) that encodes the receptor for colony stimulating factor 1 (csf-1). we examined the capacity of recombinant human csf-1 (produced in a yeast expression system) to stimulate the growth of v-fms transformed rat fibroblasts. recombinant human csf-1 bound to v-fms transformed fibroblasts with high affinity (apparent kd = 6.0 x 10(-10) m); only non-spec ... | 1988 | 2856249 |
| molecular cloning of a feline leukemia virus that induces fatal immunodeficiency disease in cats. | a replication-defective variant of feline leukemia virus was molecularly cloned directly from infected tissue and found to induce a rapid and fatal immunodeficiency syndrome in cats. studies with cloned viruses also showed that subtle mutational changes would convert a minimally pathogenic virus into one that would induce an acute form of immunodeficiency. the data suggest that acutely pathogenic viruses may be selected against by current methods for isolation of the human and simian immunodefic ... | 1988 | 2893454 |
| transduction of endogenous envelope genes by feline leukaemia virus in vitro. | feline leukaemia viruses (felv) are exogenous retroviruses that can be detected in most cats with leukaemia, aplastic anaemia, myeloproliferative diseases and fatal immunosuppression. felv isolates have been divided into three subgroups, based on the viral envelope-determined properties of interference and host range in vitro. felv-a is present in all natural isolates and is generally minimally pathogenic. felv-b is found with felv-a in isolates from approximately 40% of natural infections and i ... | 1988 | 2895894 |
| retroviruses: leukemia and immunosuppression. the yohei ito memorial lecture. | 1988 | 2904514 | |
| non-lymphoid hematopoietic neoplasia in cats: a retrospective study of 60 cases. | sixty cats with hematologic abnormalities indicative of non-lymphoid hematopoietic neoplasia were classified into two groups, myelodysplastic syndromes (mds) and acute myelogenous leukemias (aml), using criteria developed for human patients with similar diseases. cats with myeloblast counts in bone marrow of less than 30% were classed as mds and cats with myeloblast counts of 30% or greater were classed as aml. the clinical, laboratory, and postmortem findings in each group were described and co ... | 1988 | 2826080 |
| o-linked glycosylation of retroviral envelope gene products. | treatment of [3h]glucosamine-labeled friend mink cell focus-forming virus (frmcf) gp70 with excess peptide:n-glycanase f (pngase f) resulted in removal of the expected seven n-linked oligosaccharide chains; however, approximately 10% of the glucosamine label was retained in the resulting 49,000-mr (49k) product. for [3h]mannose-labeled gp70, similar treatment led to removal of all the carbohydrate label from the protein. prior digestion of the pngase f-treated gp70 with neuraminidase resulted in ... | 1988 | 2828650 |
| strong sequence conservation among horizontally transmissible, minimally pathogenic feline leukemia viruses. | we report the first complete nucleotide sequence (8,440 base pairs) of a biologically active feline leukemia virus (felv), designated felv-61e (or f6a), and the molecular cloning, biological activity, and env-long terminal repeat (ltr) sequence of another felv isolate, felv-3281 (or f3a). f6a corresponds to the non-disease-specific common-form component of the immunodeficiency disease-inducing strain of felv, felv-faids, and was isolated from tissue dna of a cat following experimental transmissi ... | 1988 | 2828667 |
| immunotherapy for feline leukemia, using staphylococcal protein a or heterologous interferons: immunopharmacologic actions and potential use. | 1988 | 2453494 | |
| the aids virus can take on many guises. | 1988 | 2457946 | |
| major structural polypeptides of retrovirus produced by a suncus murinus mammary tumor cell line and type d retrovirus share interspecies antigenic determinants. | constitutive polypeptides of retrovirus produced by a suncus murinus mammary tumor cell line (sm-mtv) were characterized by immunofluorescence and immunoblotting. the major structural polypeptide of sm-mtv, molecular weight 44/43k, immunologically cross reacted with the structural polypeptides of mason-pfizer monkey virus (mpmv) (molecular weights 27k and 12/10k). sm-mtv constitutive polypeptides did not show antigenic relatedness with those of the following mammalian retroviruses: murine mammar ... | 1988 | 2460996 |
| induction of anti-viral immune response by immunization with monoclonal anti-idiotype antibodies directed to private idiotopes. | syngeneic monoclonal anti-idiotypic antibodies were raised against idiotopes on neutralizing monoclonal antibodies with specificity for feline leukemia virus and canine parvovirus. the anti-idiotypic antibodies were shown to recognize paratope-related private idiotopes. mice were injected with the monoclonal anti-idiotypic antibodies and the sera of these mice were screened for antiviral reactivities. antibodies to both feline leukemia and canine parvovirus could be induced as determined by elis ... | 1989 | 2482029 |
| posttranslational modifications distinguish the envelope glycoprotein of the immunodeficiency disease-inducing feline leukemia virus retrovirus. | the envelope glycoprotein (gp70) of a molecularly cloned, replication-defective feline leukemia virus (felv-faids clone 61c) carries determinants for induction of fatal immunodeficiency disease, whereas the gp70 of its companion replication-competent, probably parent virus (clone 61e) does not. immunoprecipitation analysis of the extracellular glycoproteins of 61e and eecc, a replication-competent viral construct composed of the 61c env and 3' long terminal repeat fused to the 61e gag-pol genes, ... | 1989 | 2535725 |
| feline lymphomas: immunological and cytochemical characterization. | the immunological and cytochemical phenotypes of five primary feline lymphomas and six feline lymphoma lines are reported. thymic lymphomas induced by the rickard strain of felv (felv-r) are of prothymocyte or (immature) cortical thymocyte origin, as these express terminal deoxynucleotidyl transferase, the guinea pig erythrocyte rosette receptor, ia antigens, partial cortisone sensitivity, and nonspecific esterase. lymphomas associated with other strains of felv form rosettes with guinea pig ery ... | 1989 | 2535958 |
| in vitro erythrocytopathic activity of an aplastic anemia-inducing feline retrovirus. | although feline leukemia viruses (felv) cause a spectrum of proliferative and anti-proliferative diseases in vivo, in vitro studies demonstrating cell lineage-specific pathogenic properties of feline retroviruses have been rare. we describe here an efficient in vitro system that demonstrates the selective cytopathic effect of a molecularly cloned anemogenic felv (felv-sarma-subgroup c; fsc) on erythroid progenitor cells. forty-eight-hour coculture of normal feline bone marrow mononuclear cells w ... | 1989 | 2536328 |
| colony forming t lymphocyte deficit in the development of feline retrovirus induced immunodeficiency syndrome. | the identification and molecular cloning of a feline leukemia virus (felv) isolate (felv-faids) that consistently produces immunodeficiency syndrome has allowed prospective investigation of events that occur in the prodromal phase of disease. using a t-lymphocyte colony forming assay (t-cfu-ic) we have demonstrated that a drastic depletion of circulating t-cfu-ic prefigures the development of clinical immunodeficiency disease in inoculated cats and correlates with the appearance and replication ... | 1989 | 2537113 |
| feline immunodeficiency virus infection in cats of japan. | a seroepidemiologic survey for feline immunodeficiency virus (fiv) infection was conducted in japan. between june and december 1987, individual sera (n = 3,323) were submitted by veterinary practitioners from many parts of the country. specimens were from 1,739 cats with clinical signs suggestive of fiv infection and from 1,584 healthy-appearing cats seen by the same practitioners. the overall fiv infection rate among cats in japan was 960/3,323 cats (28.9%). the infection rate was more than 3 t ... | 1989 | 2537270 |
| serologic response of domestic ferrets (mustela putorius furo) to canine distemper and rabies virus vaccines. | nine unrelated 12-week-old naive domestic ferrets (mustela putorius furo) were used to evaluate the serologic responses to commercial canine distemper virus (cdv) and rabies virus (rv) vaccines. five of the ferrets (group 1) were inoculated 3 times at 2-week intervals with a multivalent modified-live virus vaccine of canine cell-line origin, containing cdv and an inactivated rv vaccine. four of the ferrets (group 2) were inoculated once with the multivalent modified-live virus vaccine containing ... | 1989 | 2537273 |
| feline leukemia virus and feline immunodeficiency virus infections in a cat with lymphoma. | lymphoma was diagnosed in a 7-year-old domestic cat found to be infected with felv and feline immunodeficiency virus (fiv). the cat was affected by chronic disorders suggestive of immunosuppression, including gingivitis, periodontitis, keratitis, and abscesses. despite treatment, peripheral keratitis of the left eye progressed, resulting in uveitis, chronic glaucoma, and eventual corneal rupture. microscopic retinal and optic disk pathologic processes also were suspected. abnormal jaw movements ... | 1989 | 2537274 |
| interleukin-2 suppression in cats naturally infected with feline leukemia virus. | feline peripheral blood lymphocytes (pbls) produce interleukin-2 (il-2) when stimulated with concanavalin a (con a) or the combination of the ca2+ ionophore a23187 (a2) plus the phorbol ester phorbol-12-myristate-13-acetate (pma). to determine the status of t helper cell function in cats naturally infected with feline leukemia virus (felv), pbls from 19 normal cats and 49 felv-infected (34 asymptomatic and 15 symptomatic) cats were tested for their ability to produce il-2 in response to con a or ... | 1989 | 2537886 |
| vaccines against tumor antigens. | effective vaccines against tumor antigens have not yet been produced. however, immunomodulators hold much promise in cancer therapy. such treatments will probably involve using combinations of various immunomodulators together with activated killer cells. development of vaccines against tumor-causing viruses seems to be a rational approach to preventing the onset of virus-induced cancers. it seems that efficient vaccines have already been developed for hepatitis b virus; such vaccines have the p ... | 1989 | 2539001 |
| structure, origin, and transforming activity of feline leukemia virus-myc recombinant provirus ftt. | a myc-containing recombinant feline leukemia provirus, designated ftt, was molecularly cloned from the cat t-cell lymphoma line f422. its transforming activity, as well as the nucleotide sequence of the 3' 2.7 kilobases of ftt, including v-myc, was determined. the predicted v-myc protein differs from feline c-myc by three amino acid changes and is truncated by two amino acids at the carboxyl terminus. comparison with feline leukemia virus (felv), feline c-myc, and other felv proviruses indicates ... | 1989 | 2539507 |
| nucleotide sequence and distinctive characteristics of the env gene of endogenous feline leukemia provirus. | nucleotide sequence analysis of the env gene of two different endogenous feline leukemia virus (felv) loci, cfe-6 and cfe-16, of domestic cats revealed the following characteristics. (i) both proviruses contain an open reading frame in the env region; (ii) whereas the full complement of the exogenous felv env is generally present in cfe-6 dna, it is truncated in cfe-16 dna such that the 5' half of the gp70 domain and the untranslated region 3' to the p15e domain have been fused by an internal de ... | 1989 | 2539525 |
| molecular cloning of a feline leukemia provirus integrated adjacent to the c-myc gene in a feline t-cell leukemia cell line and the unique structure of its long terminal repeat. | this paper reports the molecular cloning of a rearranged c-myc region from the ft-1 cell line, which was derived from a spontaneous feline t-cell leukemia carrying the feline leukemia virus (felv). an abnormal c-myc ecori fragment of about 18 kilobases, detected by southern blotting, was molecularly cloned from the dna of the ft-1 cell line. the c-myc rearrangement in ft-1 was due to direct integration of the felv provirus genome immediately upstream of the c-myc gene in the opposite transcripti ... | 1989 | 2539700 |
| feline leukemia virus-induced immunodeficiency syndrome in cats as a model for evaluation of antiretroviral therapy. | severe progressive immunodeficiency syndrome can be induced experimentally with a molecularly cloned isolate of feline leukemia virus (felv-faids). the resultant disease syndrome is characterized by persistent viremia, lymphopenia, progressive weight loss, persistent diarrhea, enteropathy, and opportunistic infections. the onset of clinical immunodeficiency disease is prefigured by the replication of the felv-faids variant virus in bone marrow and other tissues. the felv-faids system can be used ... | 1989 | 2540109 |
| testing of nucleoside analogues in cats infected with feline leukemia virus: a model. | in the present communication we evaluate the feline leukemia virus (felv) infection of cats as a model for antiretroviral chemotherapy studies. additionally, we report the results of testing the antiviral effect of the compounds, 3'-azido-3'-deoxythymidine (azt), 2',3'-dideoxycytidine, 2',3'-dideoxyinosine and 2',3'-dideoxyadenosine against felv replication in vitro. cumulative data from experiments in which felv-infected cats were treated with azt at different stages of experimental infection a ... | 1989 | 2540111 |
| negative control region at the 5' end of murine leukemia virus long terminal repeats. | using in vitro protein binding and in vivo functional studies, we have identified novel regulatory sequences near the 5' end of murine leukemia virus (mulv) long terminal repeats (ltrs). these sequences are highly conserved in all mulv ltrs as well as in feline leukemia virus and gibbon ape leukemia virus ltrs. in this upstream conserved region (ucr), gel retardation assays detected two overlapping but distinct binding sites (ucr-u and ucr-l) for nuclear proteins (ucrf-u and ucrf-l). three lines ... | 1989 | 2540425 |
| prevalence of feline calicivirus, feline leukaemia virus and antibodies to fiv in cats with chronic stomatitis. | the prevalence of feline calicivirus (fcv), feline leukaemia virus (felv) and feline immunodeficiency virus (fiv) antibodies were assessed in 78 british and 18 north american household cats with chronic stomatitis and in appropriate controls. in british cats, fcv was significantly (p less than 0.005) more prevalent in both hospital (92 per cent) and general practice (79 per cent) cases compared to their controls (19 per cent in both cases). a similar difference in prevalence of fcv was noted in ... | 1989 | 2541529 |
| atypical localised viral expression in a cat with feline leukaemia. | 1989 | 2541530 | |
| free gp70 from felv: enrichment from cell culture fluid by ferric oxide-agarose chromatography. | a new chromatographic material based on beads of macroporous crosslinked agarose containing ferric oxide particles was used for enrichment of gp70--the envelope glycoprotein of feline leukemia virus (felv). free gp70 was purified from cell culture fluid in one step with a recovery of 50 to 60% and a purification of about 60 times. the described procedure is a suitable first step for the purification of gp70 from large volumes of cell culture fluid. | 1989 | 2541738 |
| retroviruses and malignant lymphoma. | retroviruses are single stranded rna viruses that possess a unique enzyme, reverse transcriptase. this enzyme facilitates the synthesis of double stranded dna intermediates able to integrate into the genome of the host cell. although primarily a means of remaining latent, this integration can have the effect of transforming the cell to malignant growth, either by activation of growth control genes in cis or trans, or by insertion of an integrated oncogene. malignant lymphomas caused by retroviru ... | 1989 | 2541838 |
| remission of felv-associated lymphosarcoma and persistent viral infection after extracorporeal immunoadsorption of plasma using staphylococcal protein a columns: details of immune response. | sixteen feline leukemia virus (felv)-infected cats with lymphosarcoma (lsa) were treated by extracorporeal immunoadsorption using staphylococcal protein a columns in order to remove immunoglobulin g (igg) and circulating immune complexes (cic) from plasma. complete viral clearance and long-lasting tumor regression were achieved in nine of the cats and tumor regression without virus clearance was observed in two other cats. since lsa cats rarely go into spontaneous remission, and since other form ... | 1989 | 2543084 |
| modulation of immunity in patients with autoimmune disease and cancer treated by extracorporeal immunoadsorption with prosorba columns. | extensive animal studies and clinical observations support an immunosuppressive role for certain antibodies and circulating immune complexes (cic) in malignant and autoimmune diseases. investigators have attempted to correct or modulate dysfunction by removal of antibodies or cic from plasma. extra-corporeal immunoadsorption of plasma over columns containing a silica matrix and covalently attached highly purified staphylococcal protein a (prosorba column) is a procedure that specifically removes ... | 1989 | 2543085 |
| hematologic effects of short-term oral diethylcarbamazine treatment given to chronically feline leukemia virus-infected cats. | diethylcarbamazine (n,n-diethyl-4-methyl-1-piperazine carboxamide [dec]) is widely used, especially in tropical regions, to prevent and treat filariasis. the antifilarial effect of this drug has been attributed to immunomodulation. evidence is accumulating to indicate that dec may mitigate the course of feline leukemia virus infection (felv) in cats. previous studies have suggested that continuous oral dec treatment given shortly after evidence of felv infection prevents or delays lymphopenia an ... | 1989 | 2543497 |
| treatment of felv-induced immunodeficiency syndrome (felv-faids) with controlled release capsular implantation of 2',3'-dideoxycytidine. | 2',3'-dideoxycytidine (ddc) inhibits replication of the immunodeficiency inducing strain of feline leukemia virus (felv-faids) in vitro at concentrations ranging from 1-10 micrograms/ml. additive antiviral effect is achieved when ddc is combined with either human recombinant alpha interferon (ifn alpha) or tumor necrosis factor (tnf) plus ifn alpha. initial in vivo pharmacokinetic studies in cats, utilizing bolus intravenous administration of ddc (20 mg/kg), resulted in peak plasma concentration ... | 1989 | 2544137 |
| feline cytotoxic large granular lymphocytes induced by recombinant human il-2. | large granular lymphocytes (lgl) have been characterized phenotypically and functionally as cytotoxic t lymphocytes, nk cells or lymphokine-activated killer cells. the most prominent morphologic feature of lgl is large cytoplasmic granules that are thought to contain the molecules responsible for cell lysis. in this study, we describe the morphologic and functional characteristics of il-2-dependent cytotoxic lymphocytes derived from feline pbl. stimulation of feline pbl with con a followed by cu ... | 1989 | 2544649 |
| concentration and purification of feline leukaemia virus (felv) and its outer envelope protein gp70 by aqueous two-phase systems. | the major protective antigens of retroviruses are considered to be their glycosylated envelope proteins. however, the methods commonly employed to enrich and purify virus from culture media such as pelleting and density-gradient centrifugation result in a low recovery of the viral external glycoproteins. this is an obvious drawback when the virus is intended for use in a vaccine. in search for alternative methods to concentrate and purify felv, we have attempted extraction in two-phase systems b ... | 1989 | 2547820 |
| diagnosis of feline leukemia virus and feline immunodeficiency virus infections. | feline leukemia virus is an oncogenic retrovirus that can result in a wide variety of neoplastic and non-neoplastic diseases, including immunosuppression. diagnosis of felv infection can be achieved by several methods, including virus isolation; ifa assay of a peripheral blood smear; and detection of a viral protein (called p27) by elisa testing of whole blood, plasma, serum, saliva, or tears. commercially available elisa kits have revolutionized felv testing and have become very popular as "in- ... | 1989 | 2549672 |
| feline immunodeficiency virus infection. | feline immunodeficiency virus (fiv) (formerly feline t-lymphotropic lentivirus or ftlv) was first isolated from a group of cats in petaluma, california in 1986. the virus is a typical lentivirus in gross and structural morphology. it replicates preferentially but not exclusively in feline t-lymphoblastoid cells, where it causes a characteristic cytopathic effect. the major structural proteins are 10, 17 (small gag), 28 (major core), 31 (endonuclease?), 41 (transmembrane?), 52 (core precursor pol ... | 1989 | 2549690 |
| felv-faids-induced immunodeficiency syndrome in cats. | findings are reviewed, relevant to elucidation of the pathogenic, genetic and biochemical properties of a single, genetically heterogeneous isolate of feline leukemia virus (felv-faids) shown to induce fatal immunodeficiency disease in nearly 100% of inoculated cats. hypotheses are suggested which pertain to the mechanism of t-cell killing by this virus, and which extrapolate findings in the felv-faids animal model to aids induced in humans by human immunodeficiency virus (hiv). | 1989 | 2549691 |
| immunodeficiency in latent feline leukemia virus infections. | challenge of naive experimental animals with a retroviral inoculum may result in one of two broad sequelae. the first is the establishment of an appropriate humoral and cellular immune response leading to a condition of immunity to subsequent infection with the retrovirus. alternatively, the host may fail to develop a successful immune response, resulting in a chronic viremia associated with immunosuppression and ultimately death due to secondary pathogens. an alternate disease course is the est ... | 1989 | 2549692 |
| felv-induced immunosuppression through alterations in signal transduction: changes in intracellular free calcium levels. | feline leukemia virus (felv) is a retrovirus with immunosuppressive properties. the mechanism(s) of immunosuppression is unknown. calcium has been shown to be a second messenger in cellular activation and regulation. this study was designed to determine whether felv alters intracellular free calcium (ifc) levels in an felv-infected feline lymphoid cell line. control cells and felv-infected cells were exposed to concanavalin a, formyl-l-methionyl-l-leucyl-l-phenylalanine, and leukotriene b4. the ... | 1989 | 2549693 |
| felv-induced immunosuppression through alterations in signal transduction: down regulation of protein kinase c. | activation of protein kinase c by a phorbol ester, 12-o-tetradecanoylphorbol-13-acetate (tpa), was shown to stimulate the respiratory burst in normal cat neutrophils. neutrophils from feline leukemia virus (felv)-exposed viremic and nonviremic cats had significant suppression of their respiratory burst when stimulated with tpa. the addition of whole ultraviolet light-inactivated felv and felv proteins to normal cat neutrophils produced no significant suppression of the respiratory burst. these d ... | 1989 | 2549694 |
| control of feline leukaemia virus. | 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 it may cause a variety of diseases, some malignant and some benign, such as immunosuppression, which bears a resemblance to aids (acquired immune deficiency syndrome) in man. felv is transmitted among cats by contagion. the main sources of infection are persistently infected carrier cats which continuously excrete virus. dissemination of fe ... | 1989 | 2549695 |
| diseases associated with spontaneous feline leukemia virus (felv) infection in cats. | more than 2000 cats sent for necropsy in order to provide a diagnosis were investigated immunohistologically using paraffin sections for the presence of a persistent infection with feline leukemia virus (felv). the spectrum of neoplastic and non-neoplastic diseases associated significantly with felv infection was determined statistically. three-quarters of the cats with persistent felv infections died of non-neoplastic diseases and about 23% died of tumors, nearly exclusively those of the leukem ... | 1989 | 2549696 |
| false-positive reactions associated with anti-mouse activity in serotests for feline leukemia virus antigen. | false-positive reactions were observed in commercial test kits designed to detect felv infections in cats. the false-positive reactions were associated with heterophilic antibody in cat serum directed primarily against mouse immunoglobulins. of 2,830 sera tested, 579 were considered felv positive or equivocal via elisa; of these, 10 were found that did not have felv antigen but did have anti-mouse antibody. with 95% confidence, 0.14% to 0.57% of cats would have such false-positive reactions in e ... | 1989 | 2551863 |
| sensitivity and specificity of blood test kits for feline leukemia virus antigen. | enzyme-linked immunosorbent assay (elisa) test kits have been used widely to diagnose felv infection. several companies have licensed such kits, but because these test kits are designed somewhat differently, a demonstration of their relative merits was needed. differences in the sensitivity and specificity of 7 commercial test kits were determined by testing sera that induce false-negative (limiting dilution of felv group specific antigen, p27), and false-positive (cat anti-mouse antibody) test ... | 1989 | 2551864 |
| interpreting feline leukemia test results. | routine prevaccinal screening for felv has inherent statistical limitations owing to the magnification of false-positive test errors by the low prevalence of felv viremia in the general cat population. positive elisa test results obtained in a screening program should be interpreted with caution, because a high proportion--approximately 72%--of such are likely to be false-positive results. on the other hand, routine screening is an excellent method for ruling out felv viremia, because a false-ne ... | 1989 | 2551866 |
| induction of aplastic anemia by intra-bone marrow inoculation of a molecularly cloned feline retrovirus. | intra-bone marrow inoculation of cells infected with molecularly cloned feline retrovirus (felv-c-sarma [fsc]) associated with aplastic anemia was examined to test the hypothesis that cell-to-cell transmission of virus might facilitate marrow cell infection and anemogenesis, a possibility suggested by in-vitro co-culture experiments. ibm inoculation of either fsc-infected feline marrow cells or fibroblasts of weanling cats bypassed age-related restriction of fsc replication, initiated viremia, c ... | 1989 | 2552228 |
| [cat retroviruses and human retroviruses: elements of comparison]. | following emotional head-lines of certain articles in the press, making believe that the cat could be susceptible to the aids virus, the authors present elements of comparison between principal feline retroviruses (the feline leucosis virus and the feline immunodeficiency virus) and the two human immunodeficiency viruses (hiv). the feline leucosis virus in differentiated from the human and the feline immunodeficiency viruses by its virological, pathological and epidemiological characteristics. b ... | 1989 | 2553219 |
| scrambled duplications in the feline leukemia virus gag gene: a putative pattern for molecular evolution. | the present study is a detailed computer-assisted analysis of the feline leukemia virus gag gene nucleotide sequence together with its flanking sequences (st-felv gag) that is compared with the aligned sectors of the moloney strain of murine leukemia virus (mo-mulv gag) and of three strains of feline sarcoma virus. it shows that perfectly matched repeated oligomers up to 13 nucleotides long are overrepresented and scattered throughout both st-felv gag and mo-mulv gag, in noncoding and coding sec ... | 1989 | 2553988 |
| prevalence of feline leukaemia virus and antibodies to feline immunodeficiency virus in cats in the united kingdom. | a representative sample of the pet cat population of the united kingdom was surveyed. blood samples from 1204 sick and 1007 healthy cats of known breed, age and sex were tested for antibodies to feline immunodeficiency virus (fiv) and feline leukaemia virus (felv). the prevalence of fiv was 19 per cent in sick cats and 6 per cent in healthy cats, and the prevalence of felv was 18 per cent in sick cats and 5 per cent in healthy cats; both infections were more common in domestic cats than in pedig ... | 1989 | 2554556 |
| lymphoid and mesenchymal tumors in transgenic mice expressing the v-fps protein-tyrosine kinase. | src, abl, and fps/fes are prototypes for a family of genes encoding nonreceptor protein-tyrosine kinases. the oncogenic potential of the v-fps protein-tyrosine kinase was investigated by introduction of the gag-fps coding sequence of fujinami sarcoma virus into the mouse germ line. transgenic mice with v-fps under the transcriptional control of a 5' human beta-globin promoter (gf) or with both 5' and 3' beta-globin regulatory sequences (gef) were viable. unexpectedly, both gf and gef transgenes ... | 1989 | 2555699 |
| animal models of aids. | animal models of aids are essential for understanding the pathogenesis of retrovirus-induced immune deficiency and encephalopathy and for development and testing of new therapies and vaccines. aids and related disorders are etiologically linked to members of the lentivirus subfamily of retroviruses; these lymphocytopathic lentiviruses are designated human immuno-deficiency virus type 1 (hiv-1) and human immuno-deficiency virus type 2 (hiv-2). the only animals susceptible to experimental hiv-1 in ... | 1989 | 2556312 |
| on interpretation of feline leukemia test results. | 1989 | 2557312 | |
| a survey of the feline leukaemia virus in singapore. | in this survey for the presence of the feline leukaemia virus (felv) in the singapore domestic cat population, the sera of two different groups of unvaccinated mainly short haired cats which were over 6 months old were sampled. the felv enzyme-linked immunoadsorbent assay (elisa) diagnostic test kit was used to detect the presence of the felv group specific (gs) antigens in the blood of cats. of the 345 clinically healthy cats surveyed, 34 sera (9.9%) were found to be positive and of the group o ... | 1989 | 2560357 |
| isolation and characterisation of a myeloid leukaemia inducing strain of feline leukaemia virus. | 1989 | 2560447 | |
| the mutated, myeloid cell-specific growth factor receptor v-fms transforms avian erythroid but not myeloid cells. | in avian hematopoietic cells, transformation by tyrosine kinase oncogenes is restricted to the erythroid lineage. to study the mechanism of this striking target cell specificity, we constructed an avian retrovirus correctly expressing the feline v-fms protein, an oncogenic version of the myeloid-specific csf-1 receptor. similar to other tyrosine kinase oncogenes (erbb, src, fps, sea), the v-fms oncogene induced progenitor cells to self-renew in an erythropoietin-independent manner. spontaneous d ... | 1989 | 2560752 |
| feline immunodeficiency virus infection in a population of pet cats from southeastern florida. | blood samples from 95 randomly selected pet cats that were brought to veterinarians in southeastern florida were tested for antibodies to feline immunodeficiency virus (fiv). virus-specific antibodies (indicative of virus infection) were found in 8 of the 95 (8.4%) cats tested. all of the virus-infected cats were males (statistically significant, p less than or equal to 0.016) and were at least 1 year of age. the 3 most severely ill cats infected with fiv were also infected with feline leukemia ... | 1989 | 2562225 |
| identification, using synthetic peptides, of the minimum amino acid sequence from the retroviral transmembrane protein p15e required for inhibition of lymphoproliferation and its similarity to gp21 of human t-lymphotropic virus types i and ii. | synthetic peptides containing portions of a highly conserved region of retroviral transmembrane proteins of human and animal retroviruses were tested for their ability to inhibit lymphoproliferation to determine the minimum amino acid sequence required. the previously reported immunosuppression mediated by the peptide cks-17 was confirmed and further localized to a sequence of eight residues essentially identical to the sequence present in the transmembrane protein gp21 of human t-lymphotropic v ... | 1989 | 2746730 |
| serological responses in cats vaccinated with felv iscom and an inactivated felv vaccine. | various approaches have been considered for generation of effective and safe vaccines against retroviruses, including hiv, with limited success. in the present vaccination study, encompassing 137 household cats, we have composed an experimental iscom subunit vaccine containing gp70 of feline leukaemia virus (felv)--the external glycosylated envelope protein, and the transmembrane protein p15e, with a commercial available inactivated felv vaccine (leukocell). the two vaccines were estimated to co ... | 1989 | 2750271 |
| formation and characterization of felv iscoms. | immunostimulating complexes (iscoms) have been prepared from feline leukaemia virus (felv) envelope proteins. the iscoms were characterized biochemically in sds-polyacrylamide gel electrophoresis showing the presence of proteins of estimated molecular weights of 15,000, 27,000 and 70,000. immunoblotting showed that both the transmembrane protein p15e and the external glycoprotein gp70 (making up the gp85 protein) were present in the iscom. furthermore, a degradation product of gp70 with an estim ... | 1989 | 2750272 |
| use of 8-methoxypsoralen and long-wavelength ultraviolet radiation for decontamination of platelet concentrates. | transmission of viral diseases through blood products remains an unsolved problem in transfusion medicine. we have developed a psoralen photochemical system for decontamination of platelet concentrates in which platelets are treated with long wavelength ultraviolet radiation (uva, 320-400 nm) in the presence of 8-methoxypsoralen (8-mop). bacteria, rna viruses, and dna viruses ranging in genome size from 1.2 x 10(6) daltons, encompassing the size range of human pathogens, were inoculated into pla ... | 1989 | 2752129 |
| clinical feline toxoplasmosis. serologic diagnosis and therapeutic management of 15 cases. | clinical toxoplasmosis was diagnosed in 15 cats by correlating serologic evidence of infection and clinical signs to either response to therapy or histopathologic demonstration of the organism. ophthalmic manifestations, primarily involving the anterior segment, were common. other common physical examination abnormalities included muscle hyperesthesia, fever, and weight loss. response to therapy was variable, but administration of clindamycin hydrochloride resulted in resolution of all clinical ... | 1989 | 2778747 |
| investigation of immunosuppressive properties of inactivated human immunodeficiency virus and possible neutralization of this effect by some patient sera. | retroviral infections are accompanied by immunosuppression in a variety of species. for feline leukemia virus, the immunosuppression has been ascribed to the transmembrane envelope protein, p15e, which suppresses the proliferative responses of cat, mouse, and human lymphocytes. a similar suppressive effect has been shown for a lysate of human immunodeficiency virus (hiv), strain htlv-iiib. here we determined that detergent-disrupted htlv-iiib lystate exerted a strong suppressive effect on pha-st ... | 1989 | 2786762 |
| virus neutralizing and enhancing epitopes characterized by synthetic oligopeptides derived from the feline leukaemia virus glycoprotein sequence. | synthetic peptides that mimic antigenic determinants of viral proteins were used in vaccine studies of feline leukaemia virus (felv) infection. immunoreactive epitopes on felv gp70 and p15e were predicted according to the criteria of their terminal position, hydrophilicity and the probability of them constituting helical structures. nineteen peptides, consisting of seven to 19 amino acid residues, were synthesized, of which two peptides were derived from the felv subtype a, 16 from subtype b and ... | 1990 | 1689371 |
| biological effects of staphylococcal protein a immunotherapy in cats with induced feline leukemia virus infection. | biological effects of staphylococcal protein a (spa) immunotherapy were studied in 5 viremic and 6 nonviremic cats with induced felv infection and in 6 control cats. the spa therapy neither reversed felv viremia nor resulted in consistent improvement in humoral immune responses to felv antigens. however, spa immunotherapy induced a proliferative response in bone marrow granulocytic lineage, possibly resulting in expression of felv-free mature neutrophils in the blood. seemingly, viral burden and ... | 1990 | 1690524 |
| receptor interference groups of 20 retroviruses plating on human cells. | the types of receptors on the surfaces of human and other mammalian cells for 13 c-type and 7 d-type retrovirus strains were determined by interference to the formation of syncytia and the plating of viral pseudotypes. all the d-type simian retroviruses (srv-1-5, smrv, po-1-lu) share a common receptor which is also utilized by the baboon and cat endogenous c-type viruses (baev, rd114). syncytial cross-interference was also observed in human cells between the gibbon ape leukemia/simian sarcoma as ... | 1990 | 1691887 |
| presentation and immunogenicity of viral epitopes on the surface of hybrid hepatitis b virus core particles produced in bacteria. | we recently reported the enhanced immunogenicity of a peptide epitope when it was presented as a fusion protein with hepatitis b core antigen. in those experiments the fusion protein was expressed in vaccinia virus. we have now refined the system so that large amounts of highly immunogenic particles can be produced using a simple bacterial expression system. we describe the expression of three different viral epitopes as chimeric particles that induce good antibody responses to each epitope afte ... | 1990 | 1693163 |
| tyrosine protein kinase activity of the hz4-feline sarcoma virus p80gag-kit-transforming protein. | the hardy-zuckerman 4 feline sarcoma virus (hz4-fesv), isolated from a feline fibrosarcoma, is a replication defective acute transforming feline retrovirus that originated by transduction of feline c-kit sequences with feline leukemia virus (felv). the v-kit sequences of the hz4-fesv, a segment of 1106 nucleotides, correspond to sequences of the cytoplasmic domain of the c-kit receptor kinase. the hz4-fesv is known to encode an 80-kilodalton protein with felv gag and kit determinants. the p80gag ... | 1990 | 1697669 |
| therapy of presymptomatic felv-induced immunodeficiency syndrome with azt in combination with alpha interferon. | azt inhibited replication of an immunodeficiency-inducing strain of feline leukemia virus (felv-faids) in vitro at concentrations as low as 0.005 microgram/ml. this antiviral activity was augmented an additional 25-30% when azt was combined with human recombinant alpha-interferon (2b) (ifn alpha). administration of azt alone or in combination with ifn alpha, beginning at the time of exposure to a 100% persistent viremia-inducing dose of felv-faids, abrogated the progression of viral infection an ... | 1990 | 1964030 |
| induction of feline immunodeficiency syndrome by feline leukemia virus: pituitary and adrenocortical dysfunctions. | seven young cats were injected with feline leukemia virus (felv); six of them became viremic. all of the viremic cats developed aids-related symptoms, i.e. lymphopenia, neutropenia, thymic atrophy, and wasting syndrome, along with an altered pituitary and adrenocortical function. these symptoms closely resemble human aids induced by hiv. it was discovered that, after 2 weeks of infection, the average amount of plasma adrenocorticotropic hormone (acth) detected in the infected cats was reduced by ... | 1990 | 1965124 |
| a serologic survey of oklahoma cats for antibodies to feline immunodeficiency virus, coronavirus, and toxoplasma gondii and for antigen to feline leukemia virus. | a serologic survey was done on 618 cat sera submitted to the oklahoma animal disease diagnostic laboratory between july 1, 1987 and june 30, 1988. the samples were collected from clinically normal and sick cats. the sera were tested for the presence of antibodies to feline immunodeficiency virus by a commercial immunoassay, to a coronavirus by an indirect fluorescent antibody test, and to toxoplasma gondii by a commercial latex agglutination test and for the presence of feline leukemia virus ant ... | 1990 | 1965583 |
| effect of administration of diethylcarbamazine on murine leukemia virus (cas-br-m) infected mice. | previous studies indicate that decreased serum viral infectivity and viral antigen levels follow oral administration of diethylcarbamazine (dec) in feline leukemia virus infected cats, even though dec has not been shown to exhibit in vitro antiviral activity. in this investigation, dec was given by oral administration or (single dose) ip injection to murine leukemia virus (cas-br-m) inoculated mice to permit evaluation of its effect on viral-induced central nervous system disease. the survival o ... | 1990 | 1967004 |
| biological activities of a synthetic peptide composed of two unlinked domains from a retroviral transmembrane protein sequence. | we report several biological activities of a synthetic peptide whose sequence contains the highly conserved region of feline leukemia virus transmembrane protein (tm) synthetically linked to another short tm-derived sequence particularly rich in polar positive residues. this 29-amino-acid peptide blocked [3h]thymidine uptake 30 to 50% by concanavalin a-stimulated cd4(+)--but not cd8(+)-enriched murine splenocytes. maximal suppression was detected at 12.5 micrograms (3 microm) to 75 micrograms (1 ... | 1990 | 1969500 |
| natural killer cell activity of rhesus macaques against retrovirus-pulsed cd4+ target cells. | rhesus peripheral blood mononuclear cells (pbmc) fail to demonstrate natural killer (nk) activity against the human t-cell lines cem, cem x 174, or sup-t1. however, these cell lines could act as nk-sensitive target cells if they were pulsed with heat-inactivated, whole simian immunodeficiency virus (siv). the ability of these siv-pulsed t-cell lines to act as nk-sensitive target cells was directly related to the relative density of cd4 on their surface. target cell generation was inhibited by pr ... | 1990 | 1975194 |
| lymphocyte subset alterations and viral determinants of immunodeficiency disease induction by the feline leukemia virus felv-faids. | the felv-faids strain of feline leukemia virus consistently induces fatal immunodeficiency. to investigate the immunopathogenesis and viral genetic determinants responsible for the induction of immunodeficiency disease in vivo, we have generated chimeras between the two major viral genomes in the original virus isolate, designated common form clone 61e and major variant clone 61c, which were molecularly cloned directly from dna of the same animal and tissue. each of three 61e/c chimeras, contain ... | 1990 | 1976822 |
| asymptomatic feline leukemia virus carrier cats have an enhanced susceptibility to feline immunodeficiency virus-induced disease. | 1990 | 1980900 | |
| lymphocyte population changes in cats naturally infected with feline immunodeficiency virus. | feline immunodeficiency virus (fiv) is associated with feline acquired immunodeficiency syndrome (faids) and has been suggested as a model for hiv-induced human aids. the most obvious immunological defect in hiv infection is a reduction in cd4+ cell numbers and an inversion of the cd4:cd8 ratio. to determine whether the same is true in fiv infection, we analyzed by flow cytometry using a panel of monoclonal antibodies to feline lymphocyte populations the cd4:cd8 ratios in cats naturally infected ... | 1990 | 1982410 |
| serological survey of the iriomote cat (felis iriomotensis) in japan. | the iriomote cat (felis iriomotensis) was first discovered on iriomote island in the yaeyama islands of japan in 1965. ten male and 11 female adult cats were captured during the 6 yr period from 1983 to 1988. these were examined for evidence of viral and mycoplasmal infections. neither mycoplasma sp. nor ureaplasma sp. were detected in swab samples of oropharyngeal and urogenital regions. a foamy virus was isolated from the oropharyngeal swab of a female cat examined in 1988. feline leukemia vir ... | 1990 | 2110982 |
| sensitivity, specificity, and predictive values of clinease-virastat saliva test for feline leukemia virus infection. | detection of virus in saliva using a commercial enzyme-linked immunosorbent assay (elisa), clinease-virastatr, was compared to evidence of felv infection by the indirect immunofluorescent antibody assay (ifa) and plasma elisa. the sensitivity and specificity of the saliva elisa were derived by comparison to ifa and plasma elisa in 103 cats from a large colony in new york state. the sensitivity of the saliva test in relation to ifa and plasma elisa was approximately 100% and 93%, respectively. th ... | 1990 | 2152775 |
| feline leukemia virus infection as a potentiating cofactor for the primary and secondary stages of experimentally induced feline immunodeficiency virus infection. | preexistent feline leukemia virus (felv) infection greatly potentiated the severity of the transient primary and chronic secondary stages of feline immunodeficiency virus (fiv) infection. of 10 felv-fiv carrier cats, 5 died of experimentally induced fiv infection, compared with 2 deaths in 10 cats infected only with felv and 1 death in 7 cats infected only with fiv. fiv-infected cats with preexistent felv infections developed severe depression, anorexia, fever, diarrhea, dehydration, weight loss ... | 1990 | 2153226 |
| randomized blind trial of a commercial felv vaccine. | a randomized blind trial of a commercial felv vaccine was conducted to evaluate its performance in cats under conditions of long-term natural exposure. seventy-nine nonviremic, seronegative cats were randomized into 2 groups. cats were given 3 doses of either felv vaccine or placebo (killed rabies virus vaccine) sc at weeks 0, 3, and 9 of the trial. six weeks later, 44 known-viremic cats were added to the colony. cats were housed in a single large room and food dishes and litter pans were used i ... | 1990 | 2154424 |
| molecular cloning and characterization of a defective recombinant feline leukaemia virus associated with myeloid leukaemia. | the gm1 strain of feline leukaemia virus (felv) was isolated from a naturally occurring case of myeloid leukaemia and induces severe haematopoietic abnormalities, including myeloblastic leukaemia, on inoculation into cats. molecular clones of felv-gm1 proviruses were obtained and studied by restriction enzyme mapping, blot hybridization and partial dna sequence analysis. two types of clone were isolated; the first was a replication-competent felv of subgroup a, resembling other low or minimally ... | 1990 | 2155287 |
| evaluation of immunosuppressive effect and efficacy of an improved-potency feline leukaemia vaccine. | an inactivated feline leukaemia vaccine was tested to determine if process improvements would permit it to be effectively used in a two-dose primary regimen versus the three-dose regimen required for a previous vaccine. twenty-five cats were vaccinated with two subcutaneous doses given 3 weeks apart. vaccinates and controls were artificially immunosuppressed to enhance susceptibility to challenge, and inoculated with virulent feline leukaemia virus (felv) 2 weeks after the second dose. following ... | 1990 | 2156386 |
| structural diversity and nuclear protein binding sites in the long terminal repeats of feline leukemia virus. | the long terminal repeat u3 sequences were determined for multiple feline leukemia virus proviruses isolated from naturally occurring t-cell tumors. heterogeneity was evident, even among proviruses cloned from individual tumors. proviruses with one, two, or three repeats of the long terminal repeat enhancer sequences coexisted in one tumor, while two proviruses with distinct direct repeats were found in another. the enhancer repeats are characteristic of retrovirus variants with accelerated leuk ... | 1990 | 2157050 |
| inhibition of phorbol ester-induced neutrophil chemiluminescence by felv. | receptor-mediated activation is accompanied by phospholipid metabolism and by calcium fluctuation resulting in a chemiluminescence (cl) response in the neutrophil. this pathway involves activation of protein kinase c (pkc) and the nadph oxidase. artificial stimulants such as phorbol esters, specifically 12-o-tetradecanylphorbol-13-acetate (tpa), circumvent the receptor-mediated pathway and activate pkc resulting in a measurable cl response. neutrophils from feline leukemia virus (felv) exposed c ... | 1990 | 2158290 |
| prevalence of disease in nonviremic cats previously exposed to feline leukemia virus. | feline leukemia virus status and antibody titer to feline oncornavirus-associated cell membrane antigen (focma) were determined on plasma from 183 outpatient cats and 61 cats from 2 closed, felv-positive, multiple-cat households. cats with focma antibody titer had a significantly (p less than 0.02) higher prevalence of history of disease than did cats without focma antibody. diseases included upper respiratory tract infections, abscesses, ear infections, lower urinary tract infections, gastroint ... | 1990 | 2158493 |
| feline immunodeficiency virus and feline leukemia virus infections and their relationships to lymphoid malignancies in cats: a retrospective study (1968-1988). | sera from 353 cats with naturally occurring feline leukemia virus (felv) infection were collected in boston, los angeles, new york city, and seattle between 1968 and 1988. these sera were retrospectively assayed by enzyme-linked immunosorbent assay for antibodies to feline immunodeficiency virus (fiv). fifty-one (14.4%) of the felv-positive sera had antibodies to fiv, indicating dual oncovirus and lentivirus infections. fiv infections were confirmed by western blot analysis, antibodies against t ... | 1990 | 2159993 |
| efficacy of a feline leukemia virus vaccine in a natural exposure challenge. | a commercial feline leukemia virus (felv) vaccine was evaluated in a natural exposure system. all kittens were negative for felv antigen on two enzyme-linked immunosorbent assay (elisa) tests and one indirect immunofluorescence antibody (ifa) test before vaccination or exposure. twenty-three kittens were vaccinated subcutaneously at nine and 12 weeks of age. the vaccinated kittens and 14 unvaccinated littermates were housed in an infected environment starting at 14 weeks. the kittens were expose ... | 1990 | 2160531 |
| purine metabolism in feline lymphomas. | deficiency of the purine metabolic enzyme adenosine deaminase causes severe immunodeficiency. retroviruses have been reported to decrease the activity of adenosine deaminase, and many retroviruses, including feline leukemia virus, cause immunodeficiency. levels of purine metabolic enzymes including adenosine deaminase and consequences of adenosine deaminase inhibition were investigated in feline leukemia virus-infected fresh tumor cells and infected and uninfected cell lines. no evidence of viru ... | 1990 | 2161136 |