| prevalence of feline leukemia virus infection in random source laboratory cats. | three years of quarantine data involving the prevalence of feline leukemia virus (felv) in laboratory cats (felis catus) was evaluated. testing was performed using a commercially available elisa system. annual prevalence of infection ranged from 5.4 to 10.7% of the 937 cats tested. results obtained with the enzyme linked immunosorbent assay (elisa) system compared well with tests performed using an immunofluorescent antibody assay system (ifa). seasonal periodicity was noted with higher infectio ... | 1987 | 3039250 |
| a micro-enzyme-linked immunosorbent assay (elisa) test for detection of feline leukemia virus in cats. | | 1981 | 6269798 |
| transforming potential of a myc-containing variant of feline leukemia virus in vitro in early-passage feline cells. | we studied a naturally occurring variant of feline leukemia virus (felv) in which the oncogene myc has substituted for a portion of the viral structural genes (myc-felv). myc-felv was rescued by replication in the presence of felv as helper, and its biological activity was examined in early-passage feline cells in vitro. infection of leukocytes from peripheral blood, spleen, or thymus, or of kitten fibroblasts did not immortalize these cells or alter them morphologically. northern blot (rna blot ... | 1987 | 3041029 |
| prevalence and sequelae of feline leukemia virus infection in laboratory cats. | over a 4-year period, 1,683 pound-source cats received at a research institution were screened for feline leukemia virus (felv) infection, using an indirect fluorescent antibody test. viremia was detected in 83 of the cats, for a prevalence of 4.9%. during this period, felv infection was detected in 5 kittens on a research project; lymphoma or anemia developed 6 to 17 months after the infections were detected. it was concluded that apparently healthy cats infected with felv may not be appropriat ... | 1981 | 6276347 |
| protection against feline leukemia by vaccination with a subunit vaccine. | an effective vaccine against feline leukemia virus infection has been developed by the collection and concentration of tissue culture medium harvested from a tumor cell line. lymphoid cells were grown to near saturation density in a normal growth medium and then transferred to a serum-free medium. the serum-free medium was collected, concentrated, and evaluated for its vaccine potential. cats receiving the vaccine emulsified in complete freund adjuvant developed high antiviral and antitumor tite ... | 1981 | 6277792 |
| isolation of a t-lymphotropic virus from domestic cats with an immunodeficiency-like syndrome. | a highly t-lymphotropic virus was isolated from cats in a cattery in which all the animals were seronegative for feline leukemia virus. a number of cats in one pen had died and several had an immunodeficiency-like syndrome. only 1 of 18 normal cats in the cattery showed serologic evidence of infection with this new virus, whereas 10 of 25 cats with signs of ill health were seropositive for the virus. tentatively designated feline t-lymphotropic lentivirus, this new feline retrovirus appears to b ... | 1987 | 3643650 |
| feline leukaemia virus testing. | | 1981 | 6278376 |
| guinea pig erythrocyte rosette formation as a nonspecific cell surface receptor assay in the cat. | the specificity of guinea pig erythrocyte (gpe) rosettes for feline peripheral blood lymphocytes was studied. of the gpe rosette-positive cells from peripheral blood, 54% were monocytes, 29% were granulocytes, and only 17% were lymphocytes. results were similar for rosettes incubated at 4 c and those incubated at 37 c. mononuclear cells separated with polyvinylpyrrolidone-coated silica formed fewer monocyte rosettes (49%) and more granulocyte rosettes (34%) than did cells separated with sodium d ... | 1986 | 3954230 |
| detection of transient and persistent feline leukaemia virus infections. | a study was made of cats persistently or transiently viraemic with feline leukaemia virus (felv) following experimental oronasal infection. cats of two ages were exposed to the virus. one group was infected when eight weeks old in the expectation that most of the cats would become persistently viraemic, and the second group when 16 weeks old, so that some would show signs of a transient infection and then recover. the periods following infection when virus was detectable in the blood and in the ... | 1982 | 6281958 |
| fucosylglycolipid metabolism in oncornavirus-transformed cell lines. | | 1973 | 4353889 |
| effects of retrovirus protein on the feline one-way mixed leukocyte reaction. | the objective of this study was to evaluate the effects of feline retrovirus protein on cat lymphocyte recognition of allogeneic cells in the mixed leukocyte reaction (mlr), using u.v.-inactivated feline leukaemia virus (felv) and a non-disease-producing endogenous cat virus (rd-114). twenty micrograms of u.v.-inactivated virus protein from each virus were added to mixed leukocyte cultures. felv induced significant suppression of the mlr (p less than 0.005) whereas no significant suppression was ... | 1983 | 6300313 |
| molecular cloning and characterization of endogenous feline leukemia virus sequences from a cat genomic library. | recombinant bacteriophage lambda clones from a cat genomic library derived from placental dna of a specific pathogen-free cat were screened to identify endogenous feline leukemia virus (felv) sequences. restriction endonuclease mapping of four different clones indicates that there are a number of similarities among them, notably the presence of a 6.0- to 6.4-kilobase pair (kbp) ecori hybridizing fragment containing portions of sequences homologous to the gag, pol, env, and long terminal repeat-l ... | 1983 | 6304345 |
| erythrocyte macrocytosis in feline leukemia virus associated anemia. | using erythrocyte volume distribution histograms (erythrograms), erythrocyte macrocytosis and anisocytosis were quantitated in 139 cats tested for feline leukemia virus group-specific antigen. feline leukemia virus-negative cats with non-regenerative anemia or normal packed cell volumes had normal mean corpuscular volume values. uninfected cats with regenerative anemia had prominent significantly increased macrocytosis and anisocytosis (p less than 0.01). ninety percent of 62 feline leukemia vir ... | 1983 | 6316617 |
| isolation of feline leukemia virus from a leopard cat cell line and search for retrovirus in wild felidae. | a strain of feline leukemia virus (felv), subgroup a, was isolated in early subpassage of a testicular fibroblast culture obtained from a captive asian leopard cat. neither felv nor rd-114 virus was recovered from cultured tissues of 15 other animals, representing eight species of wild felidae. | 1981 | 6268887 |
| feline leukemia virus nonproducer lymphosarcomas of cats as a model for the etiology of human leukemias. | | 1981 | 6274764 |
| [feline leukemia virus (felv) and felv-associated diseases in cats: a review]. | feline leukaemia virus (felv) usually occurs in its natural species, the domestic cat. felv is also important to human individuals as a comparative model, as felv may cause a variety of diseases which are partly malignant and partly benign, such as immunosuppression which bears a resemblance to aids (acquired immune deficiency syndrome) in man. although felv is a common infective agent, the incidence of disease due to felv is much higher in cats kept in closed households in which several of them ... | 1987 | 3039686 |
| selective effect of feline leukaemia virus on early erythroid precursors. | | 1982 | 6278316 |
| 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 |
| chronic idiopathic neutropenia in a cat. | persistent neutropenia (0-0.6 x 10(9) neutrophils/l) was documented during a 10-month period in a 4-year-old spayed female domestic shorthair cat that was presented for anorexia and depression. salient abnormalities detected on physical examination were fever (40.3 degrees c), dehydration, and gingivitis. the cat was neutropenic (0.5 x 10(9) neutrophils/l) and enzyme-linked immunosorbent assay (elisa) test for feline leukemia virus was negative. a bone marrow aspirate showed decreased numbers of ... | 1988 | 3221355 |
| the u3 portion of feline leukemia virus dna identifies horizontally acquired proviruses in leukemic cats. | the presence and location of dna sequences related to the u3 and u5 portions of the infectious exogenous feline leukemia virus (felv) long terminal repeat (ltr) in various cat dnas have been determined by hybridization experiments. in uninfected cat dnas, the u5 ltr segment from the gardner-arnstein strain b virus is present at approximately 150 copies per cell. this level is approximately 10-fold greater than that of endogenous internal felv sequences. the u5 sequences differ in copy number and ... | 1981 | 6278488 |
| retroviruses in human leukemia. | after decades of work, a retrovirus of true human origin has been isolated first from a u.s. adult case of t-cell lymphoma and then from cases from various regions of the world. this virus, named htlv-i, is strongly associated with a malignant leukemia-lymphoma of mature t-cells. this disease was first clinically characterized in japan but subsequently found to cluster in the caribbean region, areas of the u.s. and in other countries. this retrovirus-associated malignancy has an adult onset and ... | 1983 | 6329935 |
| feline leukemia: a naturally occurring cancer of infectious origin. | | 1982 | 6291969 |
| a fluorescent antibody technique for the detection of the group-specific antigen of feline leukemia virus in infected tissue-culture cells. | | 1971 | 4105993 |
| rd 114 virus-specific sequences in feline cellular rna: detection and characterization. | rna extracted from cat cells contains sequences homologous to rd-114 viral rna. the sequences are measured by molecular hybridization with a single-stranded dna probe synthesized by the virion polymerase using the endogenous viral rna as template. viral-specific rna has been detected in all cells of cat origin tested thus far, but not in cells of other animals, except for the virus-producing human rhabdomyosarcoma cell, rd-114. the extent of hybridization of the dna probe to cellular rna was equ ... | 1973 | 4358169 |
| editorial: cat leukemia: a threat to man? | | 1974 | 4359320 |
| is it possible to catch leukemia from a cat? | | 1995 | 7616826 |
| 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 |
| molecular genetic characterization of the rd-114 gene family of endogenous feline retroviral sequences. | rd-114 is a replication-competent, xenotropic retrovirus which is homologous to a family of moderately repetitive dna sequences present at ca. 20 copies in the normal cellular genome of domestic cats. to examine the extent and character of genomic divergence of the rd-114 gene family as well as to assess their positional association within the cat genome, we have prepared a series of molecular clones of endogenous rd-114 dna segments from a genomic library of cat cellular dna. their restriction ... | 1984 | 6090693 |
| the management of feline lymphosarcoma. | lymphoma may occur in almost any site, in a cat of any age, in either a felv-infected or uninfected animal. as the most common tumor type found in this species, lsa should be included in the differential diagnosis for virtually any clinical problem in any body system. for the unusual forms of this malignancy, just as for the more common types, the prognosis and response to cytotoxic therapy is generally based on the pretreatment volume and location of the tumor, as well as on the overall status ... | 1984 | 6097009 |
| [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 |
| biochemical and immunological properties of the dna polymerase and rnaase h activities of purified feline leukemia virus reverse transcriptase. | feline leukemia virus dna polymerase was purified by ion-exchange and nucleic acid affinity chromatographies. the enzyme consists of a single polypeptide chain of mol. wt. approx. 72,000 as determined by both glycerol density gradient centrifugation and sds-polyacrylamide gel electrophoresis. the preferred divalent cation for dna synthesis is mn2+ on a variety of template-primers, and its optimum concentration appears to be significantly lower than reported results of other mammalian type-c vira ... | 1980 | 6159069 |
| nucleotide sequences of feline retroviral oncogenes (v-fes) provide evidence for a family of tyrosine-specific protein kinase genes. | the nucleotide sequences encoding the transforming polyproteins of the snyder-theilen and gardner-arnstein strains of feline sarcoma virus (fesv) have been determined. these sequences include a viral transforming gene (v-fes), derived from cellular proto-oncogene sequences (c-fes) of domestic cats by recombination with feline leukemia virus (felv). the v-fes sequences are predicted to encode a polypeptide domain strikingly similar to that specified by the transforming gene (v-fps) of the avian f ... | 1982 | 6183005 |
| monoclonal antibodies to three epitopic regions of feline leukemia virus p27 and their use in enzyme-linked immunosorbent assay of p27. | three different monoclonal antibodies were developed against the major core protein (p27) of feline leukemia virus (felv). each antibody was directed against a different epitope of the species-specific portion of felv-p27. the 3 antibodies reacted with 5 different isolates of felv but not with 7 other retroviruses (mulv (rauscher), mulv (akr), mpmv, mmtv, smrv, baev, rd 114). these monoclonal antibodies could readily be adapted to an enzyme-linked immunosorbent assay (elisa) for the specific mea ... | 1983 | 6186744 |
| [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 |
| protection of cats against feline leukemia virus-positive and virus-negative tumors by complement-dependent antibody. | | 1980 | 6246303 |
| feline chronic progressive polyarthritis. | twenty cats with a chronic progressive polyarthritis were studied. the disorder occurred exclusively in male cats, and all but six of the cats were between 1.5 and 5.0 years of age. there were two forms of the disease as determined by radiographic changes: joint instability and deformity, and clinical course. the most prevalent form of the disease was characterized by osteopenia and periosteal new bone formation surrounding affected joints. marginal periarticular erosions and collapse of the joi ... | 1980 | 6250422 |
| feline leukemia. | | 1980 | 6251017 |
| thoughts on retroviruses. | | 1995 | 7782231 |
| in defense of leukoassay f. | | 1980 | 6254939 |
| feline leukemia virus and hepatitis b virus: a comparison of late manifestations. | | 1981 | 6262865 |
| hematologic abnormalities preceding apparent recovery from feline leukemia virus infection. | a 5-month-old domestic short-haired cat was referred to the western college of veterinary medicine because of hemorrhage from the mouth. neutropenia and bone marrow dyscrasia developed within 2 weeks, and results of a fluorescent antibody test for feline leukemia virus (felv) were positive. during the next 6 months, the feline oncornavirus cell membrane-associated antibody titer increased, the hematologic abnormalities regressed, and the cat became negative to the felv fluorescent antibody test ... | 1981 | 6263848 |
| isolation of a novel subgroup b feline leukemia virus from a cat infected with felv-a. | proviruses were cloned directly from a cat that developed neurological disorders approximately 28 months after inoculation with a molecularly cloned, minimally pathogenic subgroup a feline leukemia virus (felv-a). in addition to felv-a proviruses that were nearly identical to the inoculated virus, we detected a subgroup b-like variant in brain, bone marrow, and lymph node that apparently had acquired the major portion of its extracellular envelope gene (gp70) from endogenous felv-related sequenc ... | 1994 | 7941350 |
| evaluation of in vivo and in vitro interactions of feline immunodeficiency virus and feline leukemia virus. | to determine the potential mechanisms for disease potentiation where feline immunodeficiency virus (fiv) infection of persistently feline leukemia virus (felv)-infected cats results in more severe fiv disease and increased mortality than fiv infection of specific pathogen-free cats. | 1994 | 7946095 |
| serologic survey and serum biochemical reference ranges of the free-ranging mountain lion (felis concolor) in california. | serum samples from 58 mountain lions (felis concolor) in california (usa) were collected between april 1987 and february 1990. nineteen serum samples were used for serum biochemistry determinations; the ranges were similar to reference values in domestic cats, captive exotic felidae and free-ranging mountain lions. a serological survey was conducted to determine whether antibodies were present against selected infectious agents. fifty-four (93%) of 58 sera had antibodies against feline panleukop ... | 1994 | 8028105 |
| 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 |
| vaccination against feline leukaemia virus. | | 1994 | 8080585 |
| [infection with feline leukemia virus: immunology and serodiagnosis as a basis for the prevention of infection. 2]. | | 1984 | 6324338 |
| a new package for an old oncogene. | | 1984 | 6325919 |
| 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 |
| characterization of the expression of cellular retrovirus genes and oncogenes in feline cells. | expression of endogenous retrovirus genes and two different cellular oncogenes (c-onc genes) was examined at the transcriptional level in a variety of normal and lymphoma/leukemia tissues of the domestic cat. the two oncogenes, c-myb(related to avian myeloblastosis virus) and c-myc(related to avian myelocytomatosis virus) were selected for their association with the induction of hematopoietic malignancies, when present in the transforming retroviruses. tissue-specific expression of endogenous fe ... | 1983 | 6329934 |
| characterization of a differentiated cat melanoma cell line. | we have established several long-term cultures of a naturally occurring metastatic melanoma of a domestic cat. the cells are fully differentiated as indicated by the fontana-masson staining of the melanin in the perinuclear region and by electron microscopy of the cytoplasmic melanosomes in various stages of development. the melanoma cells do not produce virus particles or the major core proteins (i.e., protein with a molecular weight of 30,000) of the feline leukemia virus or the endogenous cat ... | 1983 | 6850643 |
| ultrasensitive retrovirus detection by a reverse transcriptase assay based on product enhancement. | reverse transcriptase (rt) is an indispensable component of infectious retroviruses. we have developed an ultrasensitive rt test in which rna of bacteriophage ms2 serves as the template for rt-mediated cdna synthesis. a fragment of the cdna is selectively amplified by polymerase chain reaction and the amplification product is analyzed by southern blot hybridization or enzyme immunoassay. the procedure was 10(6) to 10(7) times more sensitive than a conventional rt test and detected as little as 1 ... | 1994 | 7509077 |
| differential antiviral activities and intracellular metabolism of 3'-azido-3'-deoxythymidine and 2',3'-dideoxyinosine in human cells. | dideoxynucleosides such as 3'-azido-3'-deoxythymidine (azt) and 2',3'-dideoxyinosine (ddi) can effectively inhibit the replication of human immunodeficiency virus (hiv) in t lymphoid cells. there is evidence that hiv can infect and replicate in other cells including monocytoid cells and macrophages. the present study compared the antiretroviral activities of ddi and azt in three lineages of human cells, i.e., molt4 (t lymphocytoid, cd4+), u937 (monocytoid, cd4+), and ht1080 (fibroblastoid, cd4-) ... | 1994 | 7526781 |
| 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 |
| cdna encoding a functional feline liver/bone/kidney-type alkaline phosphatase. | feline alkaline phosphatase (fealp) was copurified with the putative 70-kda feline leukemia virus subgroup-a (felv-a) receptor protein from feline t-lymphocyte cells (fet) by two-dimensional gel electrophoresis. the sequence of the n-terminal 17 amino acids and five other internal tryptic peptides revealed that it is homologous to the liver/bone/kidney (l/b/k)-type alkaline phosphatase of other mammalian species. corresponding oligonucleotides were synthesized and used for amplification of a 1.2 ... | 1995 | 7574682 |
| recombinant felv vaccine: long-term protection and effect on course and outcome of fiv infection. | the efficacy and the long-term protection of a recombinant feline leukemia virus (felv) vaccine were determined in 30 specified pathogen free cats for over 3 years. at the same time, in order to specify the effects of feline immunodeficiency virus (fiv) on the immune system, one half of the cats (n = 15) were previously infected with the swiss isolate fiv zurich 2. the second half of the animals (n = 15) served as non-infected controls. eighteen (nine fiv-negative, nine fiv-positive) vaccinated ... | 1995 | 7618252 |
| therapeutic effects of diethylcarbamazine and 3'-azido-3'-deoxythymidine on feline leukemia virus lymphoma formation. | twenty-four specific pathogen-free kittens were infected with the rickard strain of feline leukemia virus (felvr). the kittens were divided into four equal groups and were orally administered either a high dose of diethylcarbamazine (dech, 12 mg kg-1), a low dose of diethylcarbamazine (decl, 3 mg kg-1), 3'-azido-3'-deoxythymidine (azt, 15 mg kg-1, b.i.d.), or a placebo (250 mg granular dextrose) daily for 10 weeks. blood was collected at 2-week intervals for complete blood counts (cbc) and flow ... | 1995 | 7618257 |
| identification of differentially expressed genes in t-lymphoid malignancies in an animal model system. | the molecular events characterizing lymphoid malignancy have been examined in an animal model system, specifically, the retroviral induction of leukemia and lymphoma in the domestic cat following infection with feline leukemia virus (felv). genes differentially expressed in felv-induced lymphomas were isolated using a strategy of differential hybridization. six genes were identified which demonstrate a higher level of expression in an felv-induced feline thymic tumor as compared with normal thym ... | 1995 | 7628875 |
| feline leukemia virus infection downmodulates the production of growth-inhibitory activity by marrow stromal cells. | to determine the role of infected marrow accessory cells in the pathogenesis of viral-associated hematologic disorders, we evaluated whether feline leukemia virus (felv) infection alters the cytoadhesive properties of long-term marrow culture (ltmc) stromal cells, the support of stromal-associated progenitors in ltmcs, and the production of progenitor growth-promoting and -inhibiting activities by marrow stromal cells. our previous studies demonstrated that ltmcs containing felv-infected stromal ... | 1995 | 7656928 |
| parasite prevalence in free-ranging farm cats, felis silvestris catus. | no animals tested were positive for feline leukemia virus antigen and chlamydia psittaci antibodies, but all were positive for antibodies to feline calicivirus (fcv), feline herpesvirus 1 (fhv1) and rotavirus. they had antibodies to feline parvovirus (96%), feline coronavirus (84% and cowpox virus (2%). antibody to feline immunodeficiency virus (fiv) was found in 53% of animals, which were less likely to be infected with haemobartonella felis, and had higher fhv antibody titres than cats without ... | 1996 | 8620914 |
| histologic classification and immunophenotype of lymphosarcomas in cats with naturally and experimentally acquired feline immunodeficiency virus infections. | lymphosarcoma (malignant lymphoma) is the commonest hematopoietic tumor in the cat. many cases are associated with feline leukemia virus (felv) infection, but epidemiologic and experimental data suggest that feline immunodeficiency virus (fiv) may also have a role in lymphomagenesis. in this paper, we describe the clinical presentation, histologic classification, and immunophenotype of lymphosarcoma in eight domestic cats with natural or experimental fiv infections. the tumors were often of unus ... | 1996 | 8740699 |
| detection of felv antigen by indirect immunofluorescence in elisa/cite negative cats. | | 1995 | 7660550 |
| haematological disorders associated with feline retrovirus infections. | feline oncornavirus and lentivirus infections have provided useful models to characterize the virus and host cell factors involved in a variety of marrow suppressive disorders and haematological malignancies. exciting recent progress has been made in the characterization of the viral genotypic features involved in felv-associated diseases. molecular studies have clearly defined the causal role of variant felv env gene determinants in two disorders: the t-lymphocyte cytopathicity and the clinical ... | 1995 | 7663052 |
| identification and deletion of sequences required for feline leukemia virus rna packaging and construction of a high-titer feline leukemia virus packaging cell line. | sequences required for specific encapsidation of feline leukemia virus (felv) genomic rna have not yet been defined. deletion of 107 nucleotides between the splice donor (sd) and the gag coding region of a prototypic subgroup a felv, 61e, resulted in an approximately 200-fold reduction of packaged viral rna. virus particle production was not disrupted by the deletion, although viral infectivity was dramatically reduced. these data indicate that the 107-nucleotide sequence comprises a portion of ... | 1996 | 8806483 |
| induction of feline leukaemia virus-neutralizing antibodies by immunization with synthetic peptides derived from the felv env gene. | the surface glycoprotein, gp70, of feline leukaemia virus (felv) contains sites which are important in inducing neutralizing antibodies. using synthetic peptides corresponding to nucleotide sequence 729-957 (amino acid sequence 243-319) of felv-a/glasgow-1, the antigenicity and immunogenicity of this part of the viral surface glycoprotein were investigated. the region contains two highly conserved domains separated by a variable region (vr4), when compared with felv of subgroups b and c, and an ... | 1993 | 7692683 |
| comparison of fibrosarcomas that developed at vaccination sites and at nonvaccination sites in cats: 239 cases (1991-1992). | questionnaires were sent to veterinarians who had submitted a fibrosarcoma from a cat to the surgical pathology services of the veterinary schools of the university of pennsylvania and tufts university between jan 1, 1991 and june 30, 1992. questionnaire items included signalment, felv and feline immunodeficiency virus status, site of sarcoma, vaccination site, vaccines used, treatment, biologic behavior of the tumor, and final outcome. data were analyzed, using student's t-test for continuous d ... | 1994 | 7698923 |
| induction of feline acquired immune deficiency syndrome by feline leukemia virus: alteration in response to hormones in the hypothalamic-pituitary-gonadal system. | male kittens who were infected with the feline leukemia virus (felv) were found at various times after exposure to contain a sequence of dysfunction in their hypothalamic-pituitary-gonadal (hpg) system. to understand whether the involved endocrine glands in this system were damaged by felv, the hypothalamus, pituitary, and testes were tested for hormonal responsiveness in vivo and in vitro. the infected cats were administered with luteinizing hormone-releasing hormone (lhrh) and human chorionic ... | 1995 | 7700890 |
| seroepidemiological survey of feline retrovirus infections in cats in taiwan in 1993 and 1994. | in order to investigate the prevalence of infections with three feline retroviruses feline immunodeficiency virus (fiv), feline leukemia virus (felv) and feline syncytial virus (fsv) in taiwan, we collected a total of 75 blood samples from cats from veterinary hospitals, a breeding cattery and a homeless shelter in 1993 and 1994. we examined the presences of anti-fiv and fsv antibodies and felv-p27 antigen in these samples by the indirect immunofluorescence and/or enzyme-linked immunosorbent ass ... | 1995 | 7756412 |
| coccidioidomycosis in 48 cats: a retrospective study (1984-1993) | coccidioidomycosis was diagnosed in 48 cats. forty-one cases were identified within a period of 3 years. coccidioides immitis was revealed by cytological or histopathological examinations, or culture in 70% of cats. the remaining 30% of cases were diagnosed by appropriate clinical signs, radiographic lesions, and serological test results. the average age of affected cats was 6.2 years with a median age of 5.0 years. fifty-four percent (n = 26) were female and 46% (n = 22) were male. domestic sho ... | 1995 | 7760314 |
| applications of pox virus vectors to vaccination: an update. | recombinant pox viruses have been generated for vaccination against heterologous pathogens. amongst these, the following are notable examples. (i) the engineering of the copenhagen strain of vaccinia virus to express the rabies virus glycoprotein. when applied in baits, this recombinant has been shown to vaccinate the red fox in europe and raccoons in the united states, stemming the spread of rabies virus infection in the wild. (ii) a fowlpox-based recombinant expressing the newcastle disease vi ... | 1996 | 8876138 |
| in vivo selection of long terminal repeat alterations in feline leukemia virus-induced thymic lymphomas. | to determine what genetic changes are selected in the enhancer sequences of the feline leukemia virus (felv) long terminal repeat in cats that develop t cell tumors, we cloned proviral u3 sequences in cats that died with thymic lymphoma following infection with molecularly cloned felv. analysis of the u3 enhancer region revealed single base changes, including point mutations in the core and flv-1 sequences. additionally, in clones from two of four cat tumors, portions of the enhancer including l ... | 1995 | 7831823 |
| hemostatic disorders in feline immunodeficiency virus-seropositive cats. | the hemostatic function of 40 feline immunodeficiency virus (fiv) seropositive and 8 fiv and feline leukemia virus (felv) seropositive cats was evaluated and compared with reference values from 30 clinically healthy cats. the fiv-positive cats were divided into 3 groups: group i included asymptomatic carriers; group ii comprised sick fiv-infected cats with illnesses not likely to influence the hemostatic system; and group iii included fiv-positive cats with diseases potentially associated with c ... | 1994 | 7837113 |
| evaluation of feline leukemia virus vaccines. | | 1994 | 7928542 |
| vaccination against feline leukaemia using a new feline herpesvirus type 1 vector. | a recombinant feline herpesvirus type 1 (fhv-1) was constructed expressing the envelope glycoprotein gene from feline leukaemia virus (felv). the expression cassette containing the long terminal repeat promoter from rous sarcoma virus was stably integrated at the locus downstream of the gc homologue in fhv-1. oronasal vaccination with recombinant fhv-1 engendered significant protection against challenge with the homologous felv-a/glasgow-1 isolate. three of four vaccinated cats did not become vi ... | 1996 | 9014292 |
| defective endogenous proviruses are expressed in feline lymphoid cells: evidence for a role in natural resistance to subgroup b feline leukemia viruses. | endogenous feline leukemia virus (felv)-related sequences (enfelv) are a family of proviral elements found in domestic cats and their close relatives. these elements can recombine with exogenous, infectious felvs of subgroup a (felv-a), giving rise to host range variants of felv-b. we found that a subset of defective enfelv proviruses is highly expressed in lymphoma cell lines and in a variety of primary tissues, including lymphoid tissues from healthy specific-pathogen-free cats. at least two r ... | 1994 | 8138999 |
| cutaneous t-cell lymphoma in a cat. | an 8-year-old castrated male cat was examined because of a chronic, nonhealing, ulcerative lesion on the left hind limb. cutaneous lymphoma was diagnosed on the basis of the morphologic appearance of malignant cells and pautrier's microabscesses on light and electron microscopic examination. the tumor was found to be of t-cell origin by use of a polyclonal antibody recognizing t-cell antigen. results of serum elisa for felv were negative. the gp70 antigen of felv was not detected immunohistochem ... | 1994 | 8163416 |
| evaluation of a feline leukemia virus vaccine in a controlled natural transmission study. | twenty-six 8-week-old specific-pathogen-free cats were vaccinated subcutaneously with 2 doses of a commercially available felv vaccine, and 26 age-matched specific-pathogen-free cats were similarly vaccinated with a placebo vaccine containing the same adjuvant as the felv vaccine. cats then were randomly assigned to 2 groups of 26 cats (13 felv-vaccinated cats and 13 control cats), and each group was housed with 5 cats previously inoculated with felv. all cats were tested biweekly for the next 2 ... | 1994 | 8188511 |
| felv vaccination. | | 1993 | 8279119 |
| recombination between feline exogenous and endogenous retroviral sequences generates tropism for cerebral endothelial cells. | brain tissues of domestic cats that died of aplastic anemia from infection with either parental feline leukemia virus (felv), subgroup c, or a mixture of felv-c and recombinants between felv-c and an endogenous felv provirus were examined by the immunoperoxidase staining technique using a monoclonal antibody (c11d8) directed against an epitope of the viral surface glycoprotein (su). positive staining of the central nervous system (cns) capillary endothelial cells with no labeling on neuronal or ... | 1994 | 8311118 |
| feline leukemia virus. immunization and prevention. | our understanding of the pathogenesis of felv infection is little changed from what was described by hardy and his colleagues in the mid-1970s. the prevention of felv infection consists, first, of avoiding the agent and, second, of providing optimum immunologic resistance. in multi-cat environments, the former is achieved through test-and-removal methods perennially reviewed in the literature and by minimizing exposure to outdoor cats. the latter is possible by attempting to maintain a low-stres ... | 1993 | 8380657 |
| advances in the understanding of feline leukaemia virus. | | 1993 | 8384389 |
| flvi-2, a target of retroviral insertional mutagenesis in feline thymic lymphosarcomas, encodes bmi-1. | lc-felv is a myc-containing strain of feline leukemia virus which induces thymic lymphosarcoma in the domestic cat with short latency. a locus in feline dna, termed flvi-2, is commonly interrupted in naturally occurring and experimentally induced thymic lymphosarcomas containing lc-felv; thus, interruption of a gene encoded by flvi-2 may cooperate with the myc oncogene in the induction of t-cell tumors by lc-felv. clones homologous to flvi-2 have been isolated from a normal human thymus cdna lib ... | 1993 | 8390036 |
| structure and function of the long terminal repeats of feline leukemia viruses derived from naturally occurring acute myeloid leukemias in cats. | long terminal repeats of feline leukemia viruses cloned from feline acute myeloid leukemias frequently contained direct repeats of 40 to 74 bp in the upstream region of the enhancer (ure). the repetitive ure conferred an enhancer function upon gene expression in myeloid cells, suggesting its association with tumorigenic potential in myeloid cells. | 1997 | 9371654 |
| a comparison of antibody responses to veterinary vaccine antigens potentiated by different adjuvants. | six adjuvant formulations were compared for their ability to potentiate the primary and memory antibody responses in mice to three companion animal vaccine immunogens--feline leukemia virus (felv), feline immunodeficiency virus (fiv), and a recombinantly-derived heartworm antigen. the combination of a novel bacterial immunostimulator, gliding bacterial adjuvant (gba), either adsorbed onto an aluminum hydroxide gel (rehydragel hpa), or emulsified with a vehicle of polyalcohol and detergent, elici ... | 1997 | 9413100 |
| a common proviral integration region, fit-1, in t-cell tumors induced by myc-containing feline leukemia viruses. | feline leukemia viruses carrying transduced v-myc genes (myc-felv) induce tumors of clonal origin, suggesting that activated myc alone is not sufficient for tumorigenesis. to investigate the hypothesis that insertional mutagenesis plays a role by activating genes which collaborate with v-myc, we looked for evidence of common proviral integration sites in these tumors. by inverse polymerase chain reaction we identified a 6-kb domain, designated fit-1, in which felv proviruses were inserted in fou ... | 1993 | 8396812 |
| systemic diseases with cutaneous manifestations. | the purpose of this article is to briefly discuss the following cutaneous manifestations of selected systemic diseases: poxvirus; feline leukemia virus (felv); feline immunodeficiency virus (fiv); herpesvirus; calcivirus; pseudorabies; plague; tularemia; toxoplasmosis; leishmania; hypothyroidism; hyperthyroidism; hyperadrenocorticism; diabetes mellitus; acromegaly; thallium poisoning; pancreatic disease; hypereosinophilic syndrome; mucopolysaccharidosis; and pansteatitis. recognition of these cu ... | 1995 | 8525575 |
| chromosomal translocations in two feline t-cell lymphomas. | two feline malignant lymphoma cell lines, ft-1 and ft-g, established from cats naturally infected with the feline leukemia virus were analyzed for chromosomal aberrations. both ft-1 and ft-g cells had a modal number of 38 which is the normal diploid (2n) chromosome number of the domestic cat. g-banding-analysis showed that ft-1 had a translocation involving the short arms of chromosome a2 and d3--t (a2;d3) (p-;p+), and ft-g had a translocation involving the short arms of chromosomes a2 and b2--t ... | 1995 | 8551803 |
| feline leukemia virus variants in experimentally induced thymic lymphosarcomas. | this study was initiated to evaluate the in vivo infectivity and pathogenicity of a group of recombinant feline leukemia viruses (rfelvs) previously generated by in vitro forced recombination between a felv subgroup a virus (felv-a) and an endogenous felv (enfelv) envelope (env) element (sheets et al., 1992, virology 190, 849-855). to determine infectivity of rfelvs, neonatal cats were inoculated with rfelvs alone or in combination with felv-a. the recombinant viruses were able to replicate effi ... | 1995 | 8553560 |
| clinicopathological and immunological characteristics of six cats with granular lymphocyte tumors. | clinical and immunological characteristics were investigated in six cases of feline granular lymphocyte (gl) tumor. the ages of the affected cats were relatively old, ranging from 4 to 13 years of age. gastrointestinal signs were commonly observed in these cases. only one of the six gl tumor cases was positive for feline leukemia virus (felv) antigen. phenotypic analysis revealed that the gl tumor cells from all of the six cases lacked the t- or b-cell markers. these gl tumor cells were examined ... | 1998 | 9597305 |
| retroviral transmission in bone allotransplantation. the effects of tissue processing. | the transmission of a retrovirus through transplantation of processed bone allografts was studied using the feline leukemia virus. the long bones of 4 previously infected donor cats were harvested and assigned to 1 of 3 treatment groups: single freeze/thaw cycle, double freeze/thaw cycle, or double freeze/thaw cycle with water flush to remove bone marrow. cortical bone grafts and corticocancellous bone grafts from each treatment group were transplanted into individual specific-pathogen-free reci ... | 1996 | 8595768 |
| use of immunohistochemistry and polymerase chain reaction for detection of oncornaviruses in formalin-fixed, paraffin-embedded fibrosarcomas from cats. | to determine whether there was intralesional infection or expression of felv or feline sarcoma virus in suspected vaccine-associated fibrosarcomas in cats. | 1996 | 8756876 |
| felv testing. | | 1996 | 8795188 |
| pulmonary and mediastinal metastases of a vaccination-site sarcoma in a cat. | sarcomas at vaccination sites in cats were first reported in 1992. recent retrospective studies have confirmed an association between these vaccination-site sarcomas (vss) and feline leukemia virus (felv) and/ or rabies vaccines. in most cases, vss are locally invasive fibrosarcomas that tend to recur but rarely metastasize. we report the mediastinal and pulmonary metastases of a vss in a felv-and feline immunodeficiency virus-negative, 8-year-old, domestic short-haired cat. the primary sarcoma ... | 1996 | 8817854 |
| caring for the retrovirus infected cat. | no commercial vaccine [correction of vacine] exists for feline immunodeficiency virus (fiv), and although feline leukemia virus (felv) vaccines are available, they are neither 100% effective nor used in all cats. these realities clearly indicate the veterinarian will be required to treat either felv- or fiv-positive cats for some time to come. the management of fiv- or felv-positive cats may require supportive therapies as well as virus-specific therapies such as zidovudine (azt; retrovir, burro ... | 1995 | 8820595 |
| hematologic abnormalities associated with retroviral infections in the cat. | feline patients with unexplained peripheral blood cytopenias, circulating immature or neoplastic cells, dysplastic or dysmorphic bone marrow abnormalities, and/or lymphoid tumors are likely suffering from an underlying retroviral infection with feline leukemia virus (felv) and/or feline immunodeficiency virus (fiv). cytopenic hematologic disorders are often caused by the direct or indirect hematosuppressive effects of these retroviruses. alternatively, secondary infections, nutritional deficienc ... | 1995 | 8820596 |
| development and testing of an inactivated feline leukemia virus vaccine. | we assessed an inactivated whole virus feline leukemia virus (felv) vaccine developed from a molecularly cloned feline leukemia virus isolate (felv-61e-a) for its ability to protect cats against homologous and heterologous virulent virus challenge. the fractions of cats that resisted the induction of persistent viremia after felv challenge were the following: (1) felv-61e-a vaccine, 95%; (2) adjuvant controls, 26%; and (3) established commercial control felv vaccine, 35%. the pre-challenge mean ... | 1995 | 8820598 |
| endogenous env elements: partners in generation of pathogenic feline leukemia viruses. | feline leukemia viruses (felvs), which are replication-competent oncoretroviruses of the domestic cat species, are contagiously transmitted in natural environments. they are capable of inducing either acute antiproliferative disease or, after prolonged latency, lymphoid malignancies in this animal population. current knowledge of the recombinational events between infectious felv and noninfectious endogenously inherited felv-like elements is reviewed, and the potential role of the derived recomb ... | 1995 | 8828142 |
| prevalence of antibodies to feline parvovirus, calicivirus, herpesvirus, coronavirus, and immunodeficiency virus and of feline leukemia virus antigen and the interrelationship of these viral infections in free-ranging lions in east africa. | while viral infections and their impact are well studied in domestic cats, only limited information is available on their occurrence in free-ranging lions. the goals of the present study were (i) to investigate the prevalence of antibodies to feline calicivirus (fcv), herpesvirus (fhv), coronavirus (fcov), parvovirus (fpv), and immunodeficiency virus (fiv) and of feline leukemia virus (felv) antigen in 311 serum samples collected between 1984 and 1991 from lions inhabiting tanzania's national pa ... | 1996 | 8877134 |
| evidence that high-dosage zidovudine at time of retrovirus exposure reduces antiviral efficacy. | the antiviral efficacy of prophylactic 3'-azido-3'-deoxythymidine (azt) therapy administered by continuous infusion or intermittent injection was compared in pediatric cats infected with feline leukemia virus. a 4-week treatment regimen of azt was initiated at -48, 8, or 96 h postinfection (p.i.). for azt therapy begun at -48 h p.i., significant efficacy was attained when therapy was given by continuous infusion but not by intermittent injection. however, when azt therapy was delayed until 96 h ... | 1996 | 8878603 |
| parameters of disease progression in long-term experimental feline retrovirus (feline immunodeficiency virus and feline leukemia virus) infections: hematology, clinical chemistry, and lymphocyte subsets. | after several years of latency, feline immunodeficiency virus (fiv) and feline leukemia virus (felv) cause fatal disease in the cat. the aim of this study was to determine laboratory parameters characteristic of disease progression which would allow a better description of the asymptomatic phase and a better understanding of the pathogenesis of the two infections. therefore, experimentally infected cats (fiv and/or felv positive) and control animals were observed over a period of 6.5 years under ... | 1997 | 9008278 |