| the use of feline herpesvirus and baculovirus as vaccine vectors for the gag and env genes of feline leukaemia virus. | the env and gag genes from feline leukaemia virus were expressed in a thymidine kinase-negative feline herpes-virus and a baculovirus. cats were vaccinated with various combinations of these recombinant viruses and 100% protection against feline leukaemia virus challenge was achieved using an immunization schedule which utilized both env and gag products delivered at both a mucosal and systemic site. | 1992 | 1321214 |
| expression of feline leukaemia virus gp85 and gag proteins and assembly into virus-like particles using the baculovirus expression vector system. | in order to test components of feline leukaemia virus (felv) as subunit vaccines, we have constructed recombinant baculoviruses that express the felv envelope glycoprotein gp85 [autographa californica nuclear polyhedrosis virus (acnpv)-gp85] and the structural protein, gag (acnpvgag). the gag protein is expressed and shed into the medium of infected cells as particles which have a buoyant density on sucrose gradients and appearance by electron microscopy similar to those of authentic felv virion ... | 1992 | 1321215 |
| studies in feline long-term marrow culture: hematopoiesis on normal and feline leukemia virus infected stromal cells. | to study the effects of feline leukemia virus (felv) on the hematopoietic microenvironment, a two-step feline long-term marrow culture (ltmc) system was developed and characterized. the adherent, stromal layer of these cultures is composed of fibroblastoid cells (50% to 80%), macrophages (10% to 30%), fat cells (10% to 20%), and large, polygonal cells that express muscle actin (1% to 2%). when fresh, enriched marrow mononuclear cells (mmnc) were added to 3-week-old irradiated stromal cultures, n ... | 1992 | 1322201 |
| [kittens and felv]. | | 1992 | 1322571 |
| detection of enhancer repeats in the long terminal repeats of feline leukemia viruses from cats with spontaneous neoplastic and nonneoplastic diseases. | enhancer duplication in the long terminal repeat of feline leukemia virus (felv) was examined in primary cells from naturally felv-infected cats with various neoplastic and nonneoplastic diseases using the polymerase chain reaction. in all cases, a 170-bp band, corresponding to a standard exogenous felv with one copy of enhancer, was detected. repeated enhancer sequences were found in all 8 cases of thymic-form lymphosarcoma, in some cases of lymphosarcoma of other forms (3/8) and myeloid tumors ... | 1992 | 1322598 |
| hematopoietic target cells of anemogenic subgroup c versus nonanemogenic subgroup a feline leukemia virus. | feline leukemia viruses (felvs) belonging to interference subgroup c induce fatal anemia resembling human pure red cell aplasia (prca). subgroup a felvs, although closely related genetically to felvs of subgroup c, do not induce prca. the determinants for prca induction by a molecularly cloned prototype subgroup c virus (felv-sarma-c [fsc]) have been localized to the n-terminal 241 amino acids of the surface glycoprotein (su) gp70. to investigate whether the anemogenic activity of fsc reflects a ... | 1992 | 1323710 |
| in vivo infection of marrow stromal fibroblasts by feline leukemia virus. | marrow stromal fibroblasts (fbs) likely play an important role in the regulation of hematopoiesis within the marrow microenvironment. infection of these cells by feline leukemia virus (felv) might not only contribute to the pathogenesis of felv-induced hematologic diseases, but could provide a reservoir for virus in the infected cat. to determine the frequency of felv infection among marrow fb precursor cells (fibroblast colony-forming units, cfu-f) of cats viremic with felv-c/sarma and felv-a/6 ... | 1992 | 1324184 |
| fistularin 3 and 11-ketofistularin 3. feline leukemia virus active bromotyrosine metabolites from the marine sponge aplysina archeri. | two brominated tyrosine metabolites, fistularin 3 [1] and a new compound 11-ketofistularin 3 [2] have been isolated from a marine sponge, aplysina archeri. their structures were determined on the basis of spectral data. both compounds inhibited the growth of feline leukemia virus. | 1992 | 1324982 |
| feline leukemia virus subgroup c phenotype evolves through distinct alterations near the n terminus of the envelope surface glycoprotein. | feline leukemia viruses (felvs) belonging to the c subgroup induce aplastic anemia in domestic cats and have the ability, unique among felv strains, to proliferate in guinea pig fibroblasts in tissue culture. previous studies have shown that the pathogenic and host range specificity of a prototype molecular clone of felv-c [felv-sarma-c (fsc)] colocalize to a region encoding the 3' 73 amino acids of the pol gene product and the n-terminal 241 amino acids of the envelope surface glycoprotein name ... | 1992 | 1326757 |
| feline leukemia virus: pathogenesis of neoplastic disease. | | 1992 | 1327427 |
| optimal administration of dual screening tests for detecting a characteristic with special reference to low prevalence diseases. | we consider the problem of deciding optimally whether a characteristic exists based on one or two screening tests. we discuss the relative merits of giving either one or two tests, including the order in which they might be given, as well as their costs. operating in the bayesian mode, we derive posterior distributions for the accuracies of the tests and the prevalence of the characteristic. applications to detecting rare conditions, such as the aids virus, are discussed. | 1992 | 1330025 |
| retrospective serologic survey for the presence of feline immunodeficiency virus antibody: a comparison of elisa and ifa techniques. | a total of 878 samples from the new york state diagnostic laboratory (nysdl), dating from january 1984 to may 1987, were examined to detect antibodies to feline immunodeficiency virus (fiv). we used 2 screening methods; an indirect immunofluorescence assay (ifa) and an enzyme-linked immunosorbent assay (elisa). of these, 211 samples were from cats that tested negative for feline leukemia virus (felv) and exhibited disease signs consistent with immunodeficiency disease; 19 (9.0%) serum samples we ... | 1992 | 1330430 |
| serologic prevalence of selected infectious diseases in cats with uveitis. | serologic evidence of infection by toxoplasma gondii, feline leukemia virus, feline coronaviruses, or feline immunodeficiency virus (fiv) is commonly found in cats with uveitis. serum samples from 124 cats with uveitis were assayed by use of elisa for the detection of t gondii-specific immunoglobulin m (igm), igg, and circulating antigens (ag), as well as an elisa for feline leukemia virus ag, an elisa for antibodies to fiv, and an indirect fluorescent antibody assay for antibodies to feline cor ... | 1992 | 1330998 |
| nonhematopoietic hepatic neoplasms in cats: 21 cases (1983-1988). | nonhematopoietic hepatic neoplasms (n = 25) were diagnosed in 21 cats during a 5.5-year period. thirteen of the neoplasms were benign bile duct adenomas and 12 were malignant, 6 of which were bile duct adenocarcinomas. all cats were greater than or equal to 10 years old, and 14 were male. main clinical signs were anorexia and lethargy, and 15 of 21 cats had hepatomegaly. all 21 cats were feline leukemia virus-test negative. although there was a trend toward high activities of serum alanine trans ... | 1992 | 1330999 |
| partial dissociation of subgroup c phenotype and in vivo behaviour in feline leukaemia viruses with chimeric envelope genes. | feline leukaemia viruses (felvs) are classified into subgroups a, b and c by their use of different host cell receptors on feline cells, a phenotype which is determined by the viral envelope. felv-a is the ubiquitous, highly infectious form of felv, and felv-c isolates are rare variants which are invariably isolated along with felv-a. the felv-c isolates share the capacity to induce acute non-regenerative anaemia and the prototype, felv-c/sarma, has strongly age-restricted infectivity for cats. ... | 1992 | 1331290 |
| early and progressive helper t-cell dysfunction in feline leukemia virus-induced immunodeficiency. | cats infected with the highly pathogenic feline leukemia virus isolate felv-faids develop an immunodeficiency syndrome characterized by progressive loss of cd4+ t cells and eventual pan-lymphocyte depletion. prior to the decline in circulating cd4+ cells, infected cats are unable to mount primary antibody responses to t-dependent antigens. we investigated whether the altered ability of helper t cells to produce cytokines necessary for b cell growth and differentiation might be a primary event in ... | 1992 | 1333529 |
| feline immunodeficiency virus: quantification in peripheral blood mononuclear cells and isolation from plasma of infected cats. | the titer of feline immunodeficiency virus in peripheral blood mononuclear cells (pbmc) and the presence of infectious virus in plasma was investigated over 20 week period in 8 experimentally infected cats, 3 uninfected cats and 2 naturally infected cats by end point dilution cultures using a feline t-lymphoblastoid cell line (mya-1). fiv was isolated from pbmc of all infected cats, but not from the uninfected cats. fiv was also isolated consistently from 100 microliters plasma from most of the ... | 1992 | 1333753 |
| amplimers with 3'-terminal phosphorothioate linkages resist degradation by vent polymerase and reduce taq polymerase mispriming. | the 3'-->5' exonuclease activity of vent, a thermostable polymerase from thermococcus litoralis, enhances dna replication fidelity but also diverts pcr primers (amplimers) from targeted amplification by degrading their 3' termini. we demonstrate that amplimers with a 3-base 3'-terminal mismatch can be efficiently truncated by vent to prime dna polymerizations that compete with the specific amplification reaction. however, amplimers with phosphorothioate bonds joining their 3'-terminal residues a ... | 1992 | 1335814 |
| pre- and postexposure chemoprophylaxis: evidence that 3'-azido-3'-dideoxythymidine inhibits feline leukemia virus disease by a drug-induced vaccine response. | the benefits of postexposure 3'-azido-3'-dideoxythymidine (azt) prophylaxis following human immunodeficiency virus exposure are unknown. we describe a comprehensive assessment of pre- and postexposure azt therapy in the feline leukemia virus (felv)-cat model for aids which included in vitro testing, an in vivo dose-response titration, a postexposure treatment study, plasma drug concentration determinations, and evaluation of the immune response to felv. in in vitro studies, azt prevented felv in ... | 1992 | 1336345 |
| effects of ultraviolet-inactivated feline leukemia virus on the production of alpha/beta interferon by feline peripheral blood mononuclear cells. | the effects of ultraviolet-inactivated feline leukemia virus (uv-felv) on the production of alpha and/or beta interferon (ifn) by mononuclear cells stimulated with the newcastle disease virus (ifn-ndv) was investigated. the production of ifn-ndv and gamma ifn was suppressed by 50% as compared to the control in the presence of 200 ng/ml or 200 micrograms/ml of uv-felv, respectively. the presence of uv-felv decreased the rate of the production, but the time to reach the plateau of the ifn activity ... | 1992 | 1336472 |
| chromosome abnormalities and oncogenesis in cat leukemias. | chromosome abnormalities are found in feline leukemia virus (felv)-infected tumor cells as well as in tumor cells free of the virus. three cell lines derived from tumors in the domestic cat (felis catus), two of thymic origin and one of multicentric lymphoma origin, were analyzed cytogenetically to determine whether the felv virus was associated with chromosomal abnormalities in these tumor cell lines. one thymic tumor and the multicentric lymphoma were felv infected. the other thymic tumor cell ... | 1992 | 1336708 |
| association between feline immunodeficiency virus antibodies and host characteristics in finnish cats. | toward the end of 1989 the largest private veterinary laboratory in finland (vet/lab) began using a commercial combined elisa test for feline immunodeficiency virus (fiv) antibodies and feline leukemia virus (felv) antigens (cite combo). the overall proportion of fiv seropositive feline samples was 5% during the 22 month study period. the number of tests performed increased slowly while the positive test results decreased with time (7% in 1990 and 4% in 1991). the decrease in prevalence was assu ... | 1992 | 1336930 |
| identification and evaluation of new primer sets for the detection of lentivirus proviral dna. | we have developed sets of degenerate oligonucleotides designed to detect pol gene sequences from any member of the lentivirus subfamily when used as primers in amplification techniques such as the polymerase chain reaction (pcr). this pan-lentivirus-specific primer set (plsps) consists of primers, lv1, lv2, and lv3, based on conserved regions common to lentiviruses only. our protocol is based on primary amplification with lv1 and lv2 followed by secondary amplification with a nested primer set b ... | 1992 | 1337258 |
| enhancement after feline immunodeficiency virus vaccination. | cats were vaccinated with one of the three preparations: purified feline immunodeficiency virus (fiv) incorporated into immune stimulating complexes (iscoms), recombinant fiv p24 iscoms, or a fixed, inactivated cell vaccine in quil a. cats inoculated with the fiv iscoms or the recombinant p24 iscoms developed high titres of antibodies against the core protein p24 but had no detectable antibodies against the env protein gp120 or virus neutralising antibodies. in contrast, all of the cats inoculat ... | 1992 | 1337397 |
| retrovirus infections in non-domestic felids: serological studies and attempts to isolate a lentivirus. | an african lioness from the zoo of zurich had to be euthanized because of an inoperable tumor. the serum tested negative for feline leukemia virus (felv) p27 antigen by enzyme-linked immunosorbent assay (elisa) but was strongly positive for feline immunodeficiency virus (fiv) antibodies by elisa and western blot. when her only offspring and mate were tested for fiv, high antibody titers to fiv were also found in their serum. lymphocytes were prepared from these two lions on different occasions a ... | 1992 | 1337398 |
| detection of feline immunodeficiency virus infection in bone marrow of cats. | natural or experimental feline immunodeficiency virus (fiv) infection in cats is often associated with hematologic abnormalities which are similar to those observed in human immunodeficiency virus (hiv) infected patients. to determine if cells in bone marrow are infected with fiv and whether severity of hematopoietic disorder is correlated with the level of viral infection, bone marrow tissues from ten experimentally and two naturally fiv infected cats were examined by in situ hybridization for ... | 1992 | 1337401 |
| tumor necrosis factor alpha levels in cats experimentally infected with feline immunodeficiency virus: effects of immunization and feline leukemia virus infection. | tumor necrosis factor alpha (tnf alpha) levels were determined by enzyme-linked immunosorbent assay (elisa) and by cell culture bioassay in supernatants of lipopolysaccharide-stimulated feline monocyte cultures and in cat serum samples. there was a good correlation between the results obtained by the two methods. from the fact that tnf alpha was neutralized quantitatively by antibodies to human tnf alpha in feline monocyte supernatants and in feline sera, it was concluded that feline tnf alpha i ... | 1992 | 1337403 |
| diseases of the european wildcat (felis silvestris schreber, 1777) in great britain. | the author describes an examination conducted in collaboration with the nature conservancy council of great britain into the status with regard to disease, conservation and genetics of the european wildcat (felis silvestris). feline leukaemia virus (felv) infection was detected by positive enzyme-linked immunosorbent assay in blood from 2 of 23 wildcats and was tested and confirmed by felv isolation in one of the two cats. this is the first time the virus has been clearly demonstrated in a free- ... | 1992 | 1339067 |
| lymphocytotoxic strains of feline leukemia virus induce apoptosis in feline t4-thymic lymphoma cells. | feline leukemia retrovirus (felv) strains with subgroup c env genes kill feline t4 lymphoma 3201 cells by 7 to 12 days after in vitro inoculation, whereas felv strains with subgroup a env genes do not. neither felv-a nor felv-c kill feline fibroblasts. felv-c, but not felv-a, is replicated to higher titer by 3201 cells and productive infection precedes death by 3 to 7 days. transcriptional activity of the felv-c long terminal repeat, as assessed by chloramphenicol acetyltransferase activity, is ... | 1992 | 1349933 |
| use of two virustatica (azt, pmea) in the treatment of fiv and of felv seropositive cats with clinical symptoms. | in the present study the therapeutic efficacy and the side effects of two antiretroviral compounds used in human acquired immunodeficiency syndrome (aids) research, 3'-azido-2',3'-dideoxythymidine (azt, zidovudine, retrovir) and 9-(2-phosphonylmethoxyethyl)adenine (pmea), were investigated in the treatment of cats naturally infected with feline immunodeficiency virus (fiv) and cats naturally infected with feline leukemia virus (felv). azt was administered subcutaneously at a dose of 5 mg kg-1 bo ... | 1992 | 1363008 |
| immunization-induced decrease of the cd4+:cd8+ ratio in cats experimentally infected with feline immunodeficiency virus. | in a previous experiment a group of 15 specified pathogen free (spf) cats were experimentally infected with a swiss isolate of feline immunodeficiency virus (fiv). a group of 15 spf cats served as fiv negative controls. nine cats of each group were vaccinated with a recombinant feline leukemia virus (felv) vaccine, six cats in each group with a placebo vaccine. all vaccinated cats developed high antibody titers to felv and were protected against subsequent felv challenge infection. in both contr ... | 1992 | 1363009 |
| persistent upregulation of mhc class ii antigen expression on t-lymphocytes from cats experimentally infected with feline immunodeficiency virus. | a significant elevation in the percentage of cd4+ and cd8+ t-lymphocytes expressing major histocompatibility complex (mhc) class ii antigens was observed in the blood of cats shortly after they were experimentally infected with feline immunodeficiency virus (fiv). in addition to an increase in the relative proportion of t-lymphocytes expressing class ii antigens, there was an increase in the density of class ii antigens on the cell surface. these elevations were still evident at the completion o ... | 1992 | 1363010 |
| use of hollow fiber technology for large scale production of viruses and viral antigens. | | 1990 | 1369281 |
| photodynamic inactivation of retrovirus by benzoporphyrin derivative: a feline leukemia virus model. | the ability of a photosensitizer, benzoporphyrin derivative monoacid ring a (bpd-ma), and either broad-spectrum (400-1200 nm) or narrow-band (600-700 nm) red light to kill feline leukemia virus (felv) and felv-infected cat t cells (cell line 3201) was investigated in culture medium containing fetal calf serum and in blood from infected cats. a molecular clone of felv, 61e, is minimally pathogenic and productively infects 3201 cells while causing no change in rate of cell division, viability, or ... | 1992 | 1371895 |
| isolation and characterization of a retrovirus from the fish genus xiphophorus. | a cell line (bst) established from neoplastic embryonal tissues of the platyfish (xiphophorus maculatus) released spontaneously retrovirus-like particles. the particles have a buoyant density of 1.16 g/ml, a mean diameter of 100 nm and the morphology of immature retroviruses. the particle-associated proteins p70, p65, and p28 react with an antiserum directed against the major internal feline leukemia virus structural protein p27. the particles are associated with a reverse transcriptase. the pur ... | 1992 | 1374984 |
| biologically selected recombinants between feline leukemia virus (felv) subgroup a and an endogenous felv element. | in efforts to elucidate the proximal leukemogens that might be produced during a feline leukemia virus (felv) infection of cats, homologous recombinations between molecularly cloned exogenous and endogenous felv proviruses of known sequences were examined in cell cultures in vitro. a plasmid containing an infectious member of the most commonly occurring felv subgroup (felv subgroup a or felv-a) was coexpressed with noninfectious constructs containing the envelope (env) gene of an endogenously in ... | 1992 | 1381539 |
| cell lines produce factors that induce fetal hemoglobin in human bfue-derived colonies. | established cell lines were screened for secretion of activities than can stimulate fetal hemoglobin (hbf) production in adult burst-forming unit-erythroid (bfue) cultures. conditioned media from four cell lines, a human teratocarcinoma, an osteosarcoma, a bladder cell carcinoma, and feline leukemia virus (felv) a-infected feline fibroblasts (fef-a cells), consistently increased the relative production of fetal globin in bfue-derived colonies. in vitro translation of rna from these cells in xeno ... | 1992 | 1384795 |
| enzyme-linked immunosorbent assays for the detection of toxoplasma gondii-specific antibodies and antigens in the aqueous humor of cats. | serum and aqueous humor samples, collected from 14 clinically normal cats and 96 cats with clinical evidence of intraocular inflammation, were assayed with elisa for toxoplasma gondii-specific immunoglobulin m (igm), t gondii-specific igg, t gondii-specific antigens, total igg, and total igm. additionally, serum was assayed with elisa for feline leukemia virus p27 antigen and antibodies against the feline immunodeficiency virus as well as with an immunofluorescent antibody assay for antibodies a ... | 1992 | 1429123 |
| [the effectiveness of paramunization for the control of feline coryza]. | 20 cats in a cat home were treated prophylactically and therapeutically with baypamun hk. the animals were allocated into three groups as described. 7 freshly admitted clinically healthy cats were treated prophylactically on day 1, 2 and 9 with 1 ml baypamun hk (group i). 7 cats, who already were allocated for one year in the home and were sick of the feline respiratory disease complex were treated as described for group i (group ii). 6 further cats, who also showed symptoms of the feline respir ... | 1992 | 1524577 |
| synthetic hexapeptides derived from the transmembrane envelope proteins of retroviruses suppress n-formylpeptide-induced monocyte polarization. | retroviral infections are frequently associated with immunosuppression. retroviral transmembrane envelope proteins (tm proteins) play an important role in this phenomenon. cks-17, a synthetic heptadecapeptide, represents the immunosuppressive site of these retroviral tm proteins. here we support on the further delineation of this immunosuppressive site using cks-17-derived hexapeptides. the n-formyl-methionyl-leucyl-phenylalanine-induced monocyte polarization assay was used throughout this study ... | 1992 | 1541910 |
| simultaneous separation and purification of mononuclear and polymorphonuclear cells from the peripheral blood of cats. | peripheral blood mononuclear cells (pbmc) and polymorphonuclear cells (pmnc) play important roles in immunodeficiency diseases and aids-like syndromes in cats caused by feline leukemia virus (felv) and presumably also when caused by feline immunodeficiency virus (fiv). for comparative or functional studies it is advantageous or necessary to obtain these cells as separate entities from the same sample of an animal. therefore, we analyzed the technical parameters of obtaining, separating and purif ... | 1992 | 1556164 |
| use of 8-methoxypsoralen and long wavelength ultraviolet radiation for decontamination of platelet concentrates. | transmission of viral diseases through blood products remains a problem in transfusion medicine. we have developed a photochemical decontamination system (pcd) for platelet concentrates (pc) utilizing treatment with long wavelength ultraviolet radiation (uva, 320-400 nm) and 8-methoxypsorlan (8-mop). this system is capable of inactivating 25-30 logs/hour of bacteria e. coli or s. aureus, 6 logs/hour of bacteriophage fd, 0.9 log/hour of bacteriophage r17, and 1.1 logs/hour of feline leukemia viru ... | 1992 | 1617193 |
| evaluation of feline immunodeficiency virus and feline leukemia virus transmembrane peptides for serological diagnosis. | the general model for retrovirus transmembrane (tm) proteins proposed by gallaher et al. (w. r. gallaher, j. m. ball, r. f. garry, m. c. griffin, and r. c. montelaro, aids res. hum. retroviruses 5:431-440, 1989) suggests that all retrovirus tm proteins may contain an immunodominant domain (imd-tm peptide) located at the apex of the tm polypeptide. although this imd-tm peptide has been shown to be immunodominant in a variety of lentivirus infections, there has not been a detailed serological anal ... | 1992 | 1629349 |
| naturally occurring animal models of the acquired immune deficiency syndrome (aids). | | 1991 | 1645558 |
| genetically-engineered subunit vaccine against feline leukaemia virus: protective immune response in cats. | a recombinant retroviral subunit vaccine has been developed that successfully protects cats from infectious feline leukaemia virus (felv) challenge. the antigen used is a non-glycosylated protein derived from the envelope glycoprotein of felv subgroup a, expressed in escherichia coli. this recombinant protein, rgp70d, includes the entire exterior envelope protein gp70, plus the first 34 amino acids from the transmembrane protein p15e. the vaccine consists of purified rgp70d absorbed on to alumin ... | 1991 | 1647576 |
| anti-idiotypic antibodies to feline leukemia virus: an approach for retroviral immunization strategies. | the present study describes an approach to the development and use of anti-idiotypic antibodies as a possible immunization strategy to prevent retroviral infection. the rationale for using anti-idiotypes (anti-ids) to try to elicit an antigenic-specific immune response is examined, and the production and characterization of polyclonal and monoclonal anti-ids are described. several techniques were used to determine antigenic mimicry and anti-id subtypes. the potential use of anti-ids in feline le ... | 1991 | 1648360 |
| prevention of retrovirus infection after injury with contaminated instruments: an experimental study. | owing to similarities between human immunodeficiency virus and feline retroviruses, the feline model was chosen for the study to investigate the efficacy of timely topical treatment of accidental human immunodeficiency virus infection in the operating room. cats were subcutaneously inoculated with either feline leukemia virus or feline immunodeficiency virus. an effort was made to neutralize the virus in loco either by infiltration of the inoculation site with povidone-iodine or with monoclonal ... | 1991 | 1648894 |
| studies of the effect of acemannan on retrovirus infections: clinical stabilization of feline leukemia virus-infected cats. | feline leukemia is a disease induced by an oncornavirus infection that inevitably causes clinically affected cats to die. it has been estimated that 40% of cats are dead within 4 weeks and 70% within 8 weeks of the onset of clinical symptoms. acemannan is a complex carbohydrate with both immunostimulatory and direct antiviral properties. administration of acemannan for 6 weeks intraperitoneally to clinically symptomatic cats significantly improved both the quality of life and the survival rate. ... | 1991 | 1648929 |
| specific association of retroviral envelope protein, p15e, with human cell surfaces. | experiments were carried out to analyze the binding sites on human cells for highly purified retroviral protein p15e isolated from feline leukemia virus, rickard strain. binding of 125i-labeled p15e was tested with surfaces of human peripheral blood lymphocytes and 3 cell lines, raji, molt-4, and u-937. 125i-labeled p15e showed specific binding to human peripheral blood lymphocytes. in addition, all of the cell lines tested showed binding of 125i-labeled p15e. using u-937 cells, we characterized ... | 1991 | 1649129 |
| viral genetic determinants of t-cell killing and immunodeficiency disease induction by the feline leukemia virus felv-faids. | within the fatal immunodeficiency disease-inducing strain of feline leukemia virus, felv-faids, are viruses which range in pathogenicity from minimally (clone 61e is the prototype) to acutely pathogenic, most of the latter of which are also replication defective (clone 61c is the prototype). mixtures of 61e and 61c virus and chimeras generated between them, but not 61e alone, killed feline t cells. t-cell killing depended on changes within a 7-amino-acid region near the c terminus of the gp70 en ... | 1991 | 1649341 |
| cytochemical and immunological properties of leukemic cells from a cat with reticuloendotheliosis. | | 1991 | 1650603 |
| pathological features of lymphoid tissues in cats with natural feline immunodeficiency virus infection. | a range of tissues from a total of 17 cats naturally infected with the feline immunodeficiency virus was examined histologically. in 11 cases, chronic inflammatory lesions were present in various tissues including, most commonly, the intestine, brain and lung. extensive inflammation in the intestinal wall was present in seven of the cats. no particular bacterial organisms were demonstrated in these inflammatory lesions. a range of changes was present in the lymph nodes, including hyperplasia, at ... | 1991 | 1651959 |
| [paramunization of felv-positive cats with pind-avi]. | 84 felv-positive cats were continually treated with the paramunity inducer (immunomodulator) pind-avi (23 healthy cats once a week, 61 diseased cats up to 3 times a week), the frequency depending on their general condition. the elisa control tests were repeated after 4 to 6 weeks. paramunization was continued in cats still viremic until remission of viremia. 21 healthy cats already reacted negatively to the first control elisa, the 2 others after 8 weeks of paramunization. within an observation ... | 1991 | 1653471 |
| recombination between feline leukemia virus subgroup b or c and endogenous env elements alters the in vitro biological activities of the viruses. | an important question in feline leukemia virus (felv) pathogenesis is whether, as in murine leukemia virus infection, homologous recombination between the infecting felv and the noninfectious endogenous felv-like proviruses serves as a significant base for the generation of proximal pathogens. to begin an analysis of this issue, several recombinant felvs were produced by using two different approaches: (i) the regions of the viral envelope (env) gene of a cloned felv (subgroup b virus [felv-b], ... | 1991 | 1658356 |
| selective impairment of humoral immunity in feline leukemia virus-induced immunodeficiency. | we used a panel of in vitro assays to investigate the nature of immune dysfunction in cats infected with felv-faids, a naturally occurring, molecularly cloned feline leukemia virus (felv) isolate which induces a fatal immunodeficiency syndrome in infected cats. during the asymptomatic period preceding immunodeficiency disease, we were unable to detect any deficits in concanavalin a-induced blastogenesis, xenogeneic mixed-lymphocyte reaction assays, stimulation of lymphocytes by soluble protein a ... | 1991 | 1659028 |
| chronic oral infections of cats and their relationship to persistent oral carriage of feline calici-, immunodeficiency, or leukemia viruses. | two hundred and twenty-six cats from the veterinary medical teaching hospital (vmth), a cat shelter, and a purebred cattery were tested for chronic feline calicivirus (fcv), feline leukemia virus (felv) and feline immunodeficiency virus (fiv) infections. chronic oral carriage of fcv was present in about one-fifth of the cats in each of the groups. fiv infection was not present in the purebred cattery, was moderately prevalent (8%) in the pet population of cats examined at the vmth for various co ... | 1991 | 1659031 |
| feline leukemia virus-associated lymphosarcoma following renal transplantation in a cat. | | 1991 | 1661037 |
| evaluation of antiviral activity and toxicity of dextran sulfate in feline leukemia virus-infected cats. | the feline leukemia virus (felv) disease model was used to conduct a toxicity and antiretrovirus efficacy trial of dextran sulfate (ds; molecular mass, 7,000 to 8,000 da). in vitro, felv infection of feline lymphoid cells was inhibited by 10 micrograms of ds per ml. ds was administered to cats by continuous intravenous infusion at doses of 600, 120, 24, or 4.8 mg/kg of body weight per day, beginning 24 h before felv challenge. doses of 24 mg/kg/day and more were excessively toxic, causing intest ... | 1991 | 1662026 |
| early therapy of feline leukemia virus infection (felv-faids) with 9-(2-phosphonylmethoxyethyl)adenine (pmea). | cats infected with molecularly cloned felv-faids develop an immunodeficiency syndrome characterized by persistent antigenemia, decline in circulating cd4+ t lymphocytes, and impaired t-cell-dependent immune responses and opportunistic infection. we evaluated the capacity of pmea to inhibit the replication of felv-faids in vitro and to inhibit the progression of felv-faids infection in vivo. we found that pmea inhibited replication of felv-faids by greater than or equal to 50% at concentrations o ... | 1991 | 1663730 |
| cryptosporidium infection in cats: prevalence of infection in domestic and feral cats in the glasgow area. | a clinical and post mortem survey of domestic and feral cats in the glasgow area revealed that 19 of 235 (8.1 per cent) were infected with cryptosporidium species. more kittens than adults were infected (p less than 0.01), and of 51 of the cats which had diarrhoea, four also had cryptosporidium infection. of seven domestic cats with cryptosporidium infection, two were also positive for feline immunodeficiency virus. there was no significant difference between the prevalence of cryptosporidium in ... | 1991 | 1664551 |
| variable suppression of feline bone marrow fibroblast colony-forming units by two isolates of feline leukemia virus. | bone marrow fibroblast colony-forming units (cfu-f) were evaluated in cats experimentally infected with different, isolates of felv. cats infected with the kawakami-theilen isolate of felv (felv-kt) had progressive decrease in the number of cfu-f at 2, 4, and 6 weeks after infection. the number of cfu-f in felv-kt-infected cats ranged from 38 to 70% of the preinoculation cfu-f value. of 3 cats with felv-kt-induced suppression of cfu-f, 2 developed fatal nonregenerative anemia. cats infected with ... | 1991 | 1664674 |
| panel report on the colloquium on feline leukemia virus/feline immunodeficiency virus: tests and vaccination. | | 1991 | 1666068 |
| overview of feline leukemia virus research. | | 1991 | 1666069 |
| feline leukemia virus infection and diseases. | feline leukemia virus is a naturally occurring, contagiously transmitted and oncogenic immunosuppressive retrovirus of cats. the effects of felv are paradoxical, causing cytoproliferative and cytosuppressive disease (eg, lymphoma and myeloproliferative disorders vs immunodeficiency and myelosuppressive disorders). in the first few weeks after virus exposure, interactions between felv and hemolymphatic system cells determine whether the virus or the cat will dominate in the host/virus relationshi ... | 1991 | 1666070 |
| pathogenesis of infection by the feline leukemia virus. | | 1991 | 1666072 |
| early events in the immunopathogenesis of feline retrovirus infections. | feline leukemia virus and feline immunodeficiency virus (fiv) are lymphotropic retroviruses that cause a wide range of diseases in domestic cats. although it is known that both viruses are capable of infecting t lymphocytes and that infected cats are lymphopenic, it was not known how infection with either virus might alter specific lymphocyte subpopulations. using a panel of monoclonal antibodies to feline lymphocyte subpopulations, we examined, by use of flow cytometric analysis, lymphocyte cha ... | 1991 | 1666073 |
| study of feline leukemia virus immunity. | fifteen specific-pathogen-free cats were experimentally infected with felv; 8 cats recovered after transient or nondetectable viremia, and 7 cats became persistently viremic. four additional cats served as noninfected controls. antibodies to whole felv (elisa and immunoblot [western] analysis), antibodies to fixed felv-infected cells, and virus-neutralizing antibodies were monitored for as long as 3 years after infection. as a group, cats that recovered after acute infection developed higher tit ... | 1991 | 1666074 |
| regulatory considerations for licensing feline leukemia virus antigen or antibody test kits. | | 1991 | 1666075 |
| development of the immunofluorescent antibody test for detection of feline leukemia virus infection in cats. | studies of the immunodetection of various microorganisms by various assay systems indicated that the most specific and sensitive assays are immunofluorescence, radioimmunoassay, and immunoblot analysis (western blot), followed by sensitive but less specific elisa and agglutination assays and, finally, by even less sensitive but very specific virus isolation and double immunodiffusion techniques. the first test for the clinical detection of felv infection in pet cats was the immunofluorescent ant ... | 1991 | 1666076 |
| enzyme-linked immunosorbent assay methods for detection of feline leukemia virus and feline immunodeficiency virus. | enzyme-linked immunosorbent assays have been widely used for diagnosis of felv and feline immunodeficiency virus (fiv) infections. various elisa kits for felv are available from several manufacturers. although these tests are configured in a variety of formats, they are all direct antigen-detection systems for the viral core protein p27. on the other hand, elisa for fiv exposure detects specific feline antibody to fiv. basic immunoassay principles and the application of elisa technology used in ... | 1991 | 1666077 |
| use of western blot and radioimmunoprecipitation for diagnosis of feline leukemia and feline immunodeficiency virus infections. | the uses and limitations of the western blot (wb) and radioimmunoprecipitation assay (ripa) techniques for study of feline immunodeficiency virus (fiv) and felv were evaluated. western blot analysis was used to detect antigenic relatedness between the 2 lentiviruses. using a rabbit serum directed against p26 of the equine infectious anemia virus (eiav) and anti-eiav horse serum obtained from an infected horse, cross-reactivity with p24 of fiv was revealed. cat sera obtained late after experiment ... | 1991 | 1666078 |
| how well do serodiagnostic tests predict the infection or disease status of cats? | | 1991 | 1666079 |
| report of the national felv/fiv awareness project. | | 1991 | 1666080 |
| 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 |
| saliva and tear tests for feline leukemia virus. | | 1991 | 1666087 |
| evaluation of feline leukemia virus diagnostic tests available for in-office use by veterinarians. | blood samples from cats were tested for felv group-specific antigen by use of an indirect immunofluorescent antibody (ifa) test, elisa, or both. several elisa kits were evaluated as they would be used in a veterinary clinic, and some elisa kits were compared with an ifa test for agreement of results. good agreement of results was evident among the commercially available elisa kits; results for most blood samples were clearly negative or decidely positive. occasionally, test results were equivoca ... | 1991 | 1666088 |
| comparative study of diagnostic testing for feline leukemia virus infection. | results of commercially available diagnostic test kits and commercial laboratory test results were compared for ability to detect felv antigen. results of the immunofluorescent antibody (ifa) test were compared with test kit elisa results and with results of a system in which samples were applied to an absorbent material, dried, sent to a laboratory, eluted, and assayed by a plate elisa. test kits were generally highly sensitive and specific, compared with the ifa test performed at a commercial ... | 1991 | 1666089 |
| protection against feline leukemia virus infection by use of an inactivated virus vaccine. | the protective immunity induced by 3 experimental felv vaccines were evaluated: prototype inactivated felv vaccine developed from a molecularly cloned felv isolate (felv-faids-61e-a); a mixture of immunodominant synthetic peptides corresponding to regions of the felv-gardner-arnstein-b (felv-ga-b) envelope proteins; and an adjuvant-disrupted but non-activated virus prepared from a non-cloned felv field isolate comprised of subgroup a and b viruses (felv-05821-ab). included as controls were paral ... | 1991 | 1666090 |
| united states department of agriculture licensing requirements for feline leukemia virus vaccines. | | 1991 | 1666091 |
| review of the first feline leukemia virus vaccine. | | 1991 | 1666092 |
| evaluation of a killed, whole virion feline leukemia virus vaccine. | | 1991 | 1666093 |
| feline leukemia virus vaccine development. | | 1991 | 1666094 |
| development of a whole killed feline leukemia virus vaccine. | a whole killed felv vaccine was developed. by use of a chromatography method of purification and concentration, the resulting vaccine has been shown to be significantly lower in bovine serum albumin and total protein contents than were the same ingredients in the starting materials. the virus was inactivated or killed as an essential part of the vaccine development process. vaccination trials with the vaccine without use of adjuvants indicated appreciable virus-neutralizing serum titer (greater ... | 1991 | 1666095 |
| development of a genetically engineered vaccine against feline leukemia virus infection. | a genetically engineered subunit vaccine against felv infection was developed. the protective immunogen in the vaccine was a purified recombinant protein containing the entire amino acid sequence of felv subgroup a gp70 envelope protein. the optimal adjuvant was determined to be a highly purified saponin, qs-21, derived from quillaja saponaria molina. a vaccine formulation containing the recombinant protein, qs-21, and aluminum hydroxide was tested in specific-pathogen-free kittens and was shown ... | 1991 | 1666096 |
| evaluation of efficacy and safety of an inactivated virus vaccine against feline leukemia virus infection. | an inactivated virus vaccine was developed for prevention of felv infection in domestic cats. when given in 2 doses, 3 weeks apart, to cats that were greater than or equal to 9 weeks old at the time of first vaccination, the vaccine prevented persistent viremia from developing in 132 of 144 (92%) vaccinates after oronasal challenge exposure with virulent felv. in contrast, persistent viremia developed after oronasal challenge exposure with felv in 39 of 45 (87%) age-matched nonvaccinated control ... | 1991 | 1666097 |
| year two of follow-up evaluation of a randomized, blind field trial of a commercial feline leukemia virus vaccine. | a blind randomized field trial of a commercial felv vaccine was conducted. cats on study were vaccinated with either a commercial felv vaccine or a placebo, then housed with felv-positive cats in a ratio of approximately 2 study cats to 1 infected cat (results of the first 12 months of the study have been reported). all surviving placebo-treated and felv-vaccinated cats were re-vaccinated 1 year after initial exposure to felv-infected cats. exposure continued for an additional 12 months, and the ... | 1991 | 1666098 |
| efficacy and safety field trials of a recombinant dna vaccine against feline leukemia virus infection. | a new recombinant gp70 vaccine was found to be safe and effective for prevention of infection by felv. the vaccine incorporates a unique purified saponin adjuvant with the recombinant antigen. serious systemic reactions were not observed during the efficacy trial. local reactions were transient and mild. more than 2,000 doses were administered to a cross section of household cats in a field safety trial. only 1 cat had hypersensitivity reaction, which resolved. among veterinarians who used the v ... | 1991 | 1666099 |
| toward vaccination against feline leukemia virus and feline immunodeficiency virus infections. | | 1991 | 1666100 |
| vaccination of cats experimentally infected with feline immunodeficiency virus, using a recombinant feline leukemia virus vaccine. | a group of 15 cats experimentally infected with a swiss isolate of feline immunodeficiency virus (fiv) and a group of 15 fiv-negative control cats were inoculated with an felv vaccine containing recombinant felv-envelope. high elisa antibody titer developed after vaccination in fiv-positive and fiv-negative cats. vaccinated and nonvaccinated controls were later challenge exposed by intraperitoneal administration of virulent felv subtype a (glasgow). although 12 of 12 nonvaccinated controls becam ... | 1991 | 1666101 |
| comparative efficacy of three commercial feline leukemia virus vaccines against methylprednisolone acetate-augmented oronasal challenge exposure with virulent virus. | three commercial felv vaccines, (a, b, and c) were purchased on the open market and administered to 8- to 20-week-old specific-pathogen-free kittens, according to manufacturers' instructions. a similar group of nonvaccinated kittens served as controls. all kittens were challenge-exposed oronasally with virulent felv 4 weeks after the final vaccination. serum samples were monitored for felv-p27 antigenemia using an elisa at 1- to 2-week intervals for at least 16 weeks after the last day of challe ... | 1991 | 1666102 |
| comparison of the efficacy of three commercial feline leukemia virus vaccines in a natural challenge exposure. | forty-seven kittens were exposed for 31 weeks to 12 felv-positive carrier cats. the carrier cats were infected with 2 laboratory strains of felv and at least 2 strains of street virus. eleven nonvaccinated control kittens and 12 vaccinated kittens were allotted to 3 groups. after 31 weeks of exposure, the following kittens were persistently blood felv positive by elisa and immunofluorescence antibody (ifa) testing: 7 of the 11 control kittens, 0 of 12 kittens inoculated with vaccine a, 5 of 12 k ... | 1991 | 1666103 |
| antibody response of kittens after vaccination followed by exposure to feline leukemia virus-infected cats. | protein (western) blot analysis and virus-neutralization assay were used to evaluate the antibody response of specific-pathogen-free kittens to felv vaccination and followed by natural exposure. several kittens had barely detectable reactions to specific felv antigens prior to vaccination or exposure. correlation was not found between protection against persistent viremia and antibody response after vaccination as measured by western blot analysis or virus neutralization assay. a statistically s ... | 1991 | 1666104 |
| management of healthy feline leukemia virus-positive cats. | | 1991 | 1666105 |
| husbandry practices for cats infected with feline leukemia virus or feline immunodeficiency virus. | cats that are persistently infected with felv or feline immunodeficiency virus but are not manifesting clinical signs of disease are at risk for developing a wide variety of immunosuppressive, degenerative, or neoplastic diseases. infected cats should be isolated to prevent transmission of virus to healthy cats, and to protect infected cats from exposure to pathogens that can cause life-threatening secondary infections. iatrogenic transmission of virus from infected cats in isolation to healthy ... | 1991 | 1666106 |
| low-dose orally administered alpha interferon treatment for feline leukemia virus infection. | | 1991 | 1666107 |
| 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 |
| conversion of human fibroblasts to tissue macrophages by the snyder-theilen feline sarcoma virus (st:fesv) is associated with the de-novo expression of il-1 alpha, il-1 beta, ifn-alpha, tnf-alpha, gm-csf, and cd4. | in an earlier study, we have demonstrated the conversion of human fibroblasts (hf) to tissue macrophages (tm) by the snyder-theilen feline sarcoma virus (st:(fesv)) [1]. the present study shows that conversion of cultured hf by the st:fesv to tm resulted in the de-novo expression of interleukin-1 alpha, il-1 beta, interferon-alpha, tumor necrosis factor-alpha, granulocyte-macrophage colony stimulating factor, and cd4. the conversion of hf to tm was also associated with increased expression of no ... | 1991 | 1667481 |