Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| report of the national felv/fiv awareness project. | 1991 | 1666080 | |
| prevalence of feline immunodeficiency virus and feline leukemia virus infections in random-source cats. | retroviral serologic profiles were generated for 506 random-source cats (felis catus) that were received by our facility during a twenty-month period. feline leukemia virus antigens were detected in plasma samples from 26 (5.1%) of the cats. antibodies to feline immunodeficiency virus were present in 24 (4.7%) of the samples tested. a single cat (0.2%) was positive for both viruses. neither gender nor vendor correlation with retroviral seropositivity could be demonstrated. | 1991 | 1667194 |
| neoplasia associated with feline immunodeficiency virus infection in cats of southern california. | between 1988 and 1991, feline immunodeficiency virus (fiv) infection status was evaluated in 1,160 cats examined at an oncology referral and general practice in los angeles, california. twenty-nine (2.5%) cats were fiv positive. neoplasia was present in 18 of the 29 (62%) cats. sampling for neoplasia was intentionally biased in the oncology referral group. however, 33% (6/18) of fiv-infected cats with neoplasia originated from the general practice. three neoplastic processes were observed; myelo ... | 1991 | 1666082 |
| comparison of diagnostic methods for feline leukemia virus and feline immunodeficiency virus. | 1991 | 1666083 | |
| ten-year study comparing enzyme-linked immunosorbent assay with the immunofluorescent antibody test for detection of feline leukemia virus infection in cats. | immunodetection tests for feline retroviruses are powerful tools used in modern veterinary practice. veterinarians must fully understand the characteristics--strengths and weaknesses--of the felv tests so that the information gained from them can be used properly. any felv elisa or immunofluorescent antibody (ifa) test is a method for detection of felv infection (the virus) and is not a diagnostic test for leukemia or other feline disease. from previous studies, it was determined that the most a ... | 1991 | 1666084 |
| comparison of four test kits for feline leukemia virus antigen. | the sensitivity and specificity of 4 commercial felv elisa kits, using blood, were compared with results of virus isolation from blood and immunofluorescent antibody (ifa) testing on blood. significant differences were not found among the 4 elisa kits. marked decrease in sensitivity of the elisa kits was detected when virus isolation was used as the standard of positivity rather than the ifa test. virus isolation was a more sensitive indicator of early infection, with marked discrepancy among re ... | 1991 | 1666085 |
| 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 |
| use of hollow fiber technology for large scale production of viruses and viral antigens. | 1990 | 1369281 | |
| 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 |
| 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 | |
| existence of feline immunodeficiency virus infection in japanese cat population since 1968. | 1990 | 2168001 | |
| 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 |
| 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 retroviruses: a brief review. | representatives of all three retrovirus subfamilies are recognized in the cat: feline leukaemia virus (an oncovirus), feline syncytium-forming virus (a spumavirus) and feline immunodeficiency virus (a lentivirus). each of these is briefly reviewed. | 1990 | 2169669 |
| 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 |
| 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 |
| feline immunodeficiency virus, feline leukaemia virus, toxoplasma gondii, and intestinal parasitic infections in taiwanese cats. | a population consisting of 70 breeder cats, 43 clinical cases, and 16 feral cats was examined for the presence of toxoplasma gondii, feline immunodeficiency virus (fiv), and feline leukaemia virus (felv). no oocysts of t. gondii were observed in 96 faecal samples; faecal samples were not available from the feral cats. other intestinal parasites identified included isospora felis (three cats), isospora rivolta (five), dipylidium canium (two), toxocara cati (four), toxascaris leonina (one), and an ... | 1990 | 2171713 |
| 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 |
| prevalence of antibody to hantavirus in some cat populations in britain. | 1990 | 2177930 | |
| feline retrovirus infections. | 1990 | 2178110 | |
| origins and characteristics of pathogenic variants of feline leukaemia virus. | 1990 | 2178111 | |
| pathogenic mechanisms of immunodeficiency syndrome and aplastic anemia induced by feline leukemia viruses. | 1990 | 2178112 | |
| the felv and siv aids pathogenesis models: search for and analysis of molecularly defined pathogens. | 1990 | 2178113 | |
| vaccination against feline retroviruses. | 1990 | 2178114 | |
| evaluation of humoral immunity tests in felv infected cats. | 1990 | 2178116 | |
| 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 |
| type c retroviral expression in spontaneous feline olfactory neuroblastomas. | three cases of spontaneous olfactory neuroblastoma (onb) in domestic cats were morphologically and immunocytochemically characterized. diagnostic light microscopic features included flexner and homer-wright rosettes, while ultrastructurally the cells had neuritic processes, intracellular intermediate filaments, and intercellular junctions. immunocytochemically, the tumors stained positively for neuron-specific enolase, cytokeratins, and s-100 protein antigens. in each case, a key finding was the ... | 1990 | 2174630 |
| alpha interferon (2b) in combination with zidovudine for the treatment of presymptomatic feline leukemia virus-induced immunodeficiency syndrome. | the therapeutic efficacies of human recombinant alpha interferon (ifn-alpha), ifn-alpha plus zidovudine (azt), and azt alone were evaluated in presymptomatic cats with established feline leukemia virus (felv)-acquired immunodeficiency syndrome (faids) infection and high levels of persistent antigenemia. subcutaneous injection of 1.6 x 10(6) u of human recombinant ifn-alpha 2b per kg delivered peak concentrations in plasma of 3,600 u/ml at 2 h postadministration with a half-life of elimination of ... | 1990 | 2178336 |
| 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 |
| a feline large granular lymphoma and its derived cell line. | a lymphoma cell line (mcc) was derived from an abdominal mass from a 13-yr-old castrated male cat. the cells resemble natural killer precursor cells, have membrane-bound granules, and are positive for chloroacetate esterase, alpha-naphthyl butyrate esterase, and tartrate-resistant acid phosphatase activities. the mcc cells are negative for rearranged feline t-cell receptor genes, negative for feline t-cytotoxic antigen, ia, and surface mu, tau, and lambda chains and do not form e-rosettes. the m ... | 1990 | 2161827 |
| 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 |
| 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 |
| 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 |
| 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 |
| flvi-1, a common integration domain of feline leukemia virus in naturally occurring lymphomas of a particular type. | a locus in feline dna, termed flvi-1, which may play an important role in the natural induction of lymphomas by feline leukemia virus (felv) was identified. examination of a bank of 21 naturally occurring felv-positive feline lymphomas revealed that felv proviral integration occurs at flvi-1 in four independent tumors (19%). independent integrations occurred within a 2.4-kilobase region of flvi-1, the probability of which by random chance can be estimated as 10(-16). several lines of evidence, i ... | 1990 | 2161948 |
| molecular cloning of feline leukemia provirus genomes integrated in the feline large granular lymphoma cells. | feline leukemia virus (felv) is a horizontally transmitted agent of the domestic cat which is known to be associated with wide spectrum of diseases of the hematopoietic system. in the present study, proviral dnas of felv proviruses were examined in the tumor cells of natural killer cell lineage which is very rare in cats. in the chromosomal dna of the tumor cells, 5 distinct bands corresponding to exogenous felv provirus genomes were detected by digestion with ecori which does not cut most felv ... | 1990 | 2162159 |
| zidovudine toxicity to cats infected with feline leukemia virus. | feline leukemia virus (felv) infection of cats is a model for the acquired immunodeficiency syndrome in humans. the toxicity of zidovudine was evaluated in spf cats experimentally infected with felv. at initiation of the zidovudine study, all cats were antibody positive for felv antigens but clinically asymptomatic. four cats were also viremic. thirteen, 6- to 10-month-old cats were divided into five dosage groups and given zidovudine po at 0, 7.5, 15, 30, or 60 mg/kg daily in three equally divi ... | 1990 | 2163339 |
| should cats be vaccinated for feline leukemia? | 1990 | 2163809 | |
| zidovudine in combination with alpha interferon and interleukin-2 as prophylactic therapy for felv-induced immunodeficiency syndrome (felv-faids). | zidovudine (3'-azido-3'-deoxythymidine; azt) inhibited replication of an immunodeficiency-inducing strain of feline leukemia virus (felv-faids) in vitro at concentrations of 0.5-0.005 micrograms/ml. a 25-30% additional antiviral effect was achieved in vitro when azt was combined with human recombinant alpha interferon 2a (ifn alpha). oral administration of azt (20 mg/kg three times daily) to cats resulted in plasma concentrations of 3 micrograms/ml at 2 h post-administration with a t1/2 of appro ... | 1990 | 2164083 |
| an unusual retrovirus-like sequence identified in human dna. | the human genome contains many different types of endogenous proviruses and retrovirus-like elements. an unusual element of this kind has been isolated from human dna on the basis of its relatedness to the integrase-coding domain of the pol gene of feline leukaemia virus (felv). the element, termed hs5, is related to felv only over a short region of 81 nucleotides predicted to encode the carboxyl terminus of the felv integrase protein, p46pol. the region of relatedness between hs5 and felv ident ... | 1990 | 2165140 |
| epizootiologic association between feline immunodeficiency virus infection and feline leukemia virus seropositivity. | five hundred twenty-one feline serum samples submitted to the texas veterinary medical diagnostic laboratory between nov 1, 1988, and jan 31, 1989 were tested for antibody to feline immunodeficiency virus (fiv) by use of an elisa. the prevalence of fiv infection in this population was 11.3% (95% confidence interval: 8.6 to 14.0%). serologic test results for felv were available for 156 of the 521 cats. a significant (p = 0.008) association between fiv infection and felv seropositivity was observe ... | 1990 | 2166726 |
| characterization and significance of delayed processing of the feline leukemia virus felv-faids envelope glycoprotein. | felv-faids, an immunodeficiency-inducing isolate of feline leukemia virus, is composed of a pathogenic but replication-defective genome (molecular clone 61c) and a replication-competent but non-immunodeficiency-inducing variant genome (molecular clone 61e). the chimeric virus eecc, composed of the 5' gag-pol of 61e fused to the env-3' ltr of 61c, also induces immunodeficiency. the 61c (or eecc) gp80 can be distinguished from that of 61e on the basis of antigenic recognition, size, and rate of po ... | 1990 | 2166820 |
| in vitro and in vivo evidence that the antiviral activity of 2',3'-dideoxycytidine is target cell dependent in a feline retrovirus animal model. | 2',3'-dideoxycytidine (ddc) was evaluated for prophylactic antiviral activity in vitro and in vivo, using the feline leukemia virus (felv)-cat animal model. in vitro antiviral activity of ddc against felv was dependent upon the target cell used for infection. ddc (5 to 10 microm) inhibited felv infection of feline lymphoid cells by greater than 80%, while 6.07 to 12.13 microm ddc was required to similarly inhibit infection of feline fibroblasts. however, 43 to 384 microm ddc was needed to inhibi ... | 1990 | 2167039 |
| [feline immunodeficiency virus in switzerland: clinical aspects and epidemiology in comparison with feline leukemia virus and coronaviruses]. | serum samples from 1421 domestic cats (561 healthy, 860 sick) were tested for fiv-, felv- and coronavirus infection. the results were stored in a computer data base and compared with epidemiologic data and clinical findings. all 3 infections were significantly more prevalent in sick than healthy cats: fiv was found in 0.7% of healthy and 3.4% of sick cats. for felv the prevalence was 3.0% and 13.0% and for coronavirus 21% and 36.2%, respectively. fiv-infected cats were mostly male (73%); no sex ... | 1990 | 2167513 |
| reference intervals for feline cerebrospinal fluid: biochemical and serologic variables, igg concentration, and electrophoretic fractionation. | reference intervals are reported for feline csf biochemical and serologic variables, igg concentration, and electrophoretic fractionation, derived from 58 clinically normal adult cats that did not have histologic lesions of the cns. there was no apparent effect of age on any variable. the csf total protein concentration was significantly (p = 0.012) greater in males than in females, but all other variables were unaffected by gender. the only variable that had a statistically significant correlat ... | 1990 | 2167619 |
| effect of toxoplasma lysate antigen (tla) on feline cytotoxicity against felv positive lymphoma cells. | the cytotoxic activities of feline spleen cells treated with toxoplasma lysate antigen (tla) were assayed against feline leukemia virus (felv)-producing lymphoma. fl74 cells, and xenogeneic target lymphoma, mouse yac-1 cells. the tla treatments were performed in vivo alone, in vitro alone, and in vivo plus in vitro, respectively. in vivo plus in vitro treatments with tla induced a marked augmentation in cytotoxic activity of spleen cells to fl74 cells. the treatment with tla in vivo alone showed ... | 1990 | 2167995 |
| fv-1 restriction of endogenous feline c-type rd114 virus genome phenotypically mixed with ecotropic murine leukemia viruses. | endogenous feline leukemia rd114 virus genome rendered capable of infecting mouse cells by phenotypic mixing with an ecotropic murine leukemia virus (mulv) exhibited the fv-1 restriction pattern of the ecotropic murine virus. however, rd114 genomes phenotypically mixed with ecotropic mulv showed one-hit dose-response kinetics, even when titrated with murine cells with the restricted fv-1 phenotype. | 1990 | 2168865 |
| recombinant feline herpesviruses expressing feline leukemia virus envelope and gag proteins. | we constructed recombinant feline herpesviruses (fhvs) expressing the envelope (env) and gag genes of feline leukemia virus (felv). expression cassettes, utilizing the human cytomegalovirus immediate-early promoter, were inserted within the thymidine kinase gene of fhv. the felv env glycoprotein expressed by recombinant fhv was processed and transported to the cell surface much as in felv infection, with the exception that proteolytic processing to yield the mature gp70 and p15e proteins was les ... | 1990 | 2168977 |
| immunosuppressive actions of retroviruses. | the immunosuppressive properties of retroviruses were first demonstrated by old et al. we later showed that gross passage a retrovirus superinfection in mice resulted in decreased antibody production and diminished allograft rejection. we have studied in some detail the immunosuppression which occurs subsequent to infection with feline leukemia virus (felv) as characterized by profoundly depressed t and b lymphocyte responses and decreased production of gamma-interferon. injection of staphylococ ... | 1990 | 2170777 |
| lymphatic tissue changes in aids and other retrovirus infections: tools and insights. | based on immunohistochemistry, in situ hybridization, and electron microscopy, lymphatic tissue changes in human immunodeficiency virus (hiv) and other retroviral infections represent different stages of a dynamic process progressing from hyperplasia to atrophy. the germinal centers (gc) function early as a virus reservoir in both hiv and feline leukemia virus infection, which also produces lymphadenopathy, severe immune impairment, and death from opportunistic infections. core proteins of hiv c ... | 1990 | 2170778 |
| the polymerase chain reaction (pcr): a valuable method for retroviral detection. | although the detection of antibodies to a specific pathogen is used initially as the assay of choice, direct detection of human retroviruses is difficult. first, only a small fraction of cells are infected in the peripheral blood and lymphatic tissue may serve as a reservoir for infection. second, infected cells may harbor only a small number of copies of the viral sequences. third, a latent infection marked by transcriptional dormancy is often established thereby obviating the use of proteins o ... | 1990 | 2170779 |
| human recombinant interleukin-2 induces maturation and activation signals for feline eosinophils in vivo. | immunotherapy, with interleukin-2 (il-2) or il-2 plus lymphokine-activated killer (lak) cells, has been used to treat cancer and acquired immunodeficiency syndrome (aids) in man. similarities between feline leukemia virus (felv) infection in the cat and human immunodeficiency virus (hiv) infection in man have prompted immunotherapeutic studies in the cat. to develop baseline data on hematological responses to infused il-2, cats were given daily (1-14 days) i.v. injections of 5 x 10(4) u/kg of re ... | 1990 | 2230598 |
| the iscom: an immunostimulating system. | to make purified antigens highly immunogenic, they have to be presented in several copies in the form of a microscopic or submicroscopic particle. this is the case, regardless of whether the antigens are obtained by isolation from conventional microorganisms, or from gene-manipulated cells, or synthesized. in the iscom, the antigens are attached as multimers to a 40-nm cage-like particle with a built-in adjuvant. the antigens in iscoms are rapidly transported from the injection site to the drain ... | 1990 | 2283159 |
| hematologic manifestations of feline immunodeficiency virus infection. | studies were done on 53 cats with community-acquired infection with the feline immunodeficiency virus (fiv) to determine if hematologic abnormalities were comparable with those observed in patients seropositive for the human immunodeficiency virus (hiv). nine cats were asymptomatic, 24 had clinical symptoms equivalent to aids-related complex (arc), and 20 had aids-like disease. hematologic abnormalities were detected in 75% (40 of 53) of fiv-seropositive cats, and multiple concurrent cytopenias ... | 1990 | 2400806 |
| iscoms. | the common problem for defined purified antigens or antigen determinants has been to make them immunogenic regardless of whether they are produced conventionally, produced as cloned genetechnology products or chemically synthesized. the first problem is to get the protective antigen into a submicroscopic particle where the antigen is presented in several copies, i.e. as a multimer. for some antigens it seems also necessary to enhance the immunogenicity with an adjuvant. the immunostimulating com ... | 1990 | 2205974 |
| 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 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |