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female cats have lower rates of apoptosis in peripheral blood lymphocytes than male cats: correlation with estradiol-17beta, but not with progesterone blood levels.during earlier study, we quantified by flow cytometry the rate of apoptotic feline lymphocytes after overnight culture. we found evidence that the sex of the animals influences the rate of apoptosis, intact females showed lower rates of apoptosis in lymphocytes cultured overnight than castrated male cats. this observation was also confirmed for cats that were previously experimentally infected with the feline immunodeficiency virus (fiv). in an attempt to find an explanation for these sexually d ...19989839870
dna vaccination affords significant protection against feline immunodeficiency virus infection without inducing detectable antiviral antibodies.to test the potential of a multigene dna vaccine against lentivirus infection, we generated a defective mutant provirus of feline immunodeficiency virus (fiv) with an in-frame deletion in pol (fivdeltart). in a first experiment, fivdeltart dna was administered intramuscularly to 10 animals, half of which also received feline gamma interferon (ifn-gamma) dna. the dna was administered in four 100-microg doses at 0, 10, and 23 weeks. immunization with fivdeltart elicited cytotoxic t-cell (ctl) resp ...19989696827
cross virus neutralizing antibodies against feline immunodeficiency virus genotypes a, b, c, d and e.feline immunodeficiency virus (fiv) is classified into five genotypes, a, b, c, d and e, based on the phylogenetic analysis of the env v3-v5 region. however, whether there is correlation between phylogenetic and antigenic diversities remains unknown. in this study, we examined the cross virus neutralization of fiv genotypes a through e by sera from cats infected with a single genotype. the results indicated some relationships between phylogenetic genotype and neutralization serotype, and that cr ...19989505973
in vivo functions of the auxiliary genes and regulatory elements of feline immunodeficiency virus.feline immunodeficiency virus (fiv) is a widespread lentivirus of domestic cats that causes an acquired immunodeficiency syndrome (aids)-like disease similar to human aids caused by human immunodeficiency virus. fiv has a complex genome structure including structural, enzymatic and auxiliary genes and regulatory elements. in this article, we review the in vivo roles of some of these fiv auxiliary genes and regulatory elements, especially focusing on the dutpase, vif, and orf-a genes and ap-1 bin ...19989646446
antibodies to orthopoxvirus in domestic cats in norway.the prevalence of antibodies to orthopoxvirus in 217 sera collected from domestic cats in the western part of norway was 10.1 per cent as measured by a competitive elisa. in one of the seropositive cats antibodies were also detected by an immunofluorescence assay. the average age of the cats sampled was 4.9 years, but the average age of the seropositive individuals was 7.3 years, higher than the average age of clinical cowpox virus cases in britain (4.2 years), and in germany (3.9 years). antibo ...19989725176
mucosally transmitted feline immunodeficiency virus induces a cd8+ antiviral response that correlates with reduction of cell-associated virus.intravaginal inoculation of cats with feline immunodeficiency virus (fiv) results in acute systemic infection accompanied by a strong cd8+ immune response that inhibits viral replication. cd8+ anti-fiv activity, revealed by increased fiv replication in peripheral blood mononuclear cells (pbmc) depleted of cd8+ lymphocytes, was detected by 6 weeks after inoculation and correlated with reduced pbmc-associated virus at 12, 16, and 32 weeks after inoculation. some cats with strong cd8+ anti-fiv acti ...19989419165
analysis of the s3 and s3' subsite specificities of feline immunodeficiency virus (fiv) protease: development of a broad-based protease inhibitor efficacious against fiv, siv, and hiv in vitro and ex vivo.the s3 and s3' subsite binding specificities of hiv and feline immunodeficiency virus proteases (fiv) proteases (prs) have been explored by using c2-symmetric competitive inhibitors. the inhibitors evaluated contained (1s, 2r, 3r, 4s)-1,4-diamino-1, 4-dibenzyl-2,3-diol as p1 and p1' units, val as p2 and p2' residues, and a variety of amino acids at the p3 and p3' positions. all inhibitors showed very high potency against hiv pr in vitro, and their ki values ranged between 1.1 and 2.6 nm. in cont ...19989448264
efficacy evaluation of prime-boost protocol: canarypoxvirus-based feline immunodeficiency virus (fiv) vaccine and inactivated fiv-infected cell vaccine against heterologous fiv challenge in cats.to evaluate the immunogenicity and prophylactic efficacy of immunization schemes employing a recombinant canarypoxvirus ('alvac')-based feline immunodeficiency virus (fiv) vaccine alone or in combination with an inactivated fiv-infected cell vaccine against homologous and heterologous fiv challenges in cats.19989456250
effects of feline immunodeficiency virus on astrocyte glutamate uptake: implications for lentivirus-induced central nervous system diseases.feline immunodeficiency virus (fiv) is a lentivirus of domestic cats that causes a spectrum of diseases remarkably similar to aids in hiv-infected humans. as part of this spectrum, both hiv-1 and fiv induce neurologic disorders. because astrocytes are essential in maintaining the homeostasis of the central nervous system, we analyzed fiv for the ability to infect feline astrocytes. through immunocytochemistry and reverse transcriptase activity, it was demonstrated that two molecular clones of fi ...19989482937
effect of enzymatic deglycosylation on feline immunodeficiency virus sensitivity to antibody-mediated neutralization.we have investigated the effect of deglycosylation with peptide-n-glycosidase f (pngase f) on the sensitivity to inhibition by immune sera of two variants of the petaluma strain of feline immunodeficiency virus (fiv-pet), one sensitive to antibody-mediated neutralization because tissue culture adapted and the other, obtained by passaging the previous one in vivo, resistant to neutralization. the partial deglycosylation achieved did not appreciably affect fiv-pet infectivity for t lymphoid cell c ...19989491909
retroviruses and sexual size dimorphism in domestic cats (felis catus l.).hochberg and co-workers have predicted that an increase in host adult mortality due to parasites is balanced by an earlier age at first reproduction. in polygynous species we hypothesize that such a pattern would lead to diverging selection pressure on body size between sexes and increased sexual size dimorphism. in polygynous mammals, male body size is considered to be an important factor for reproductive success. thus, under the pressure of a virulent infection, males should be selected for ra ...19989493404
delayed infection after immunization with a peptide from the transmembrane glycoprotein of the feline immunodeficiency virus.recent advances in the quantitative assessment of viral burden, by permitting the extension of criteria applied to assess the efficacy of vaccines from all-or-none protection to diminution of the viral burden, may allow the identification of original immunogens of value in combined vaccines. peptides corresponding to three domains of the envelope glycoproteins of feline immunodeficiency virus that are recognized during natural infection were used to immunize cats. after challenge with a primary ...19989499101
interstitial lung disease in feline immunodeficiency virus (fiv) infected cats.postmortem bronchoalveolar lavage of feline immunodeficiency virus-infected cats indicated an alveolitis process, and histological examination of their lungs confirmed the occurrence of alveolitis, parenchymatous lymphoplasmocytic infiltration and myomatosis. similar lymphoid interstitial pneumonitis has been described in human and animal lentiviral diseases: lymphocytic interstitial pneumonitis in hiv-1-infected human beings, and maedi in sheep infected by the maedi-visna virus. such lymphoid i ...19979300550
perspectives on fiv vaccine development.feline immunodeficiency virus (fiv), discovered a decade ago, is the causative agent of feline immunodeficiency syndrome (faids), a chronically degenerative, fatal disease in domestic cats. our understanding of the immunopathogenesis of fiv has improved but the development of an effective therapy and prophylaxis has been slow, reflecting the remarkable adaptability of the virus to modern medical intervention. fiv vaccine development has had its successes and failures similar to those encountered ...19979302758
vaccination with a feline immunodeficiency virus multiepitopic peptide induces cell-mediated and humoral immune responses in cats, but does not confer protection.cats were immunized with a 46-residue multiepitopic synthetic peptide of feline immunodeficiency virus (fiv) comprising immunodominant epitopes present in the third variable domain of the envelope glycoprotein, transmembrane glycoprotein (tm), and p24 gag core protein, using quil a as an adjuvant. all vaccinated cats developed a humoral response which recognized the synthetic peptide immunogen and the intact viral core and envelope proteins. a fiv gag- and env-specific effector cytotoxic t-lymph ...19979311839
characterization of the transcription map and rev activity of a highly cytopathic feline immunodeficiency virus.a highly cytopathic feline immunodeficiency virus, fiv-oma, was previously isolated from a nondomestic cat. in this report, we describe experiments to characterize its transcription map and examine its rev activity. the temporal progression of viral gene expression is similar to that of hiv-1. the splicing pattern of viral transcripts was determined by sequence analysis of rt-pcr-amplified viral cdnas. in vitro transcription and translation of two putative rev cdnas revealed that they encode at ...19979325234
a comparison of antibody responses to veterinary vaccine antigens potentiated by different adjuvants.six adjuvant formulations were compared for their ability to potentiate the primary and memory antibody responses in mice to three companion animal vaccine immunogens--feline leukemia virus (felv), feline immunodeficiency virus (fiv), and a recombinantly-derived heartworm antigen. the combination of a novel bacterial immunostimulator, gliding bacterial adjuvant (gba), either adsorbed onto an aluminum hydroxide gel (rehydragel hpa), or emulsified with a vehicle of polyalcohol and detergent, elici ...19979413100
molecular analysis of the feline immunodeficiency virus protease: generation of a novel form of the protease by autoproteolysis and construction of cleavage-resistant proteases.the feline immunodeficiency virus (fiv) protease is essential for virion maturation and subsequent viral replication in that it cleaves the gag and gag/pol polyproteins at eight sites to release the respective structural proteins and enzymes. during purification of a recombinant fiv protease (pr), we noted that it underwent autoproteolysis (autolysis) to give discrete cleavage products. these additional pr cleavage sites were defined using n-terminal amino acid sequence analysis and mass spectro ...19979188624
growth of lion and puma lentiviruses in domestic cat cells and comparisons with fiv.feline immunodeficiency virus (fiv-fca) is a lentivirus that causes gradual immunological deterioration in domestic cats. lentiviruses related to fiv have been detected in several nondomestic feline species; the biologic significance of these viruses remains to be defined. to examine the in vitro cell tropism of these nondomestic cat lentiviruses, prototypical puma and lion lentiviruses (fiv-pco and fiv-ple) were cultured in a variety of feline cell cultures. a domestic cat t lymphoma cell line, ...19979201228
mechanism(s) of fiv vaccine protection.infection of domestic cats with the feline immunodeficiency virus (fiv) represents an important veterinary health problem and a useful animal model for the development of vaccines against aids. two experimental fiv vaccines have been developed: one consisting of fixed infected cells and the other of inactivated whole virus. both vaccines elicited strong ctl responses to fiv and high virus neutralizing (vn) antibody titers. over 90% of vaccinated cats were protected against intraperitoneal infect ...19979209311
dynamics of two feline retroviruses (fiv and felv) within one population of cats.we present a deterministic model of the dynamics of two microparasites simultaneously infecting a single host population. both microparasites are feline retroviruses, namely feline immunodeficiency virus (fiv) and feline leukaemia virus (felv). the host is the domestic cat felis catus. the model has been tested with data generated by a long-term study of several natural cat populations. stability analysis and simulations show that, once introduced in a population, fiv spreads and is maintained, ...19979225475
targeting antiviral nucleotide analogues to macrophages.macrophages are important target cells for human immunodeficiency virus type 1 (hiv-1) infection. we have developed a drug targeting system for the selective delivery of phosphorylated nucleoside analogues to these phagocytosing cells. this system is based on the possibility of encapsulating the phosphorylated drugs into autologous erythrocytes and on the subsequent selective modification of their membranes to promote macrophage recognition and phagocytosis. targeted delivery of phosphorylated n ...19979226004
shared usage of the chemokine receptor cxcr4 by the feline and human immunodeficiency viruses.feline immunodeficiency virus (fiv) induces a disease state in the domestic cat that is similar to aids in human immunodeficiency virus (hiv)-infected individuals. as with hiv, fiv can be divided into primary and cell culture-adapted isolates. adaptation of fiv to replicate and form syncytia in the crandell feline kidney (crfk) cell line is accompanied by an increase in the net charge of the v3 loop of the envelope glycoprotein, mirroring the changes observed in the v3 loop of hiv gp120 with the ...19979261358
a single amino acid substitution in the transmembrane envelope glycoprotein of feline immunodeficiency virus alters cellular tropism.the cellular tropism of the feline immunodeficiency virus (fiv) is affected by changes in variable region 3 (v3) of the surface (su) envelope glycoprotein (verschoor, e. j., et al., j. virol. 69:4752-4757, 1995). by using high-dose dna transfection, an fiv molecular clone with a non-crfk-tropic v3 acquired the ability to replicate in crfk cells. a single point mutation from a methionine to a threonine in the ectodomain of its transmembrane (tm) envelope glycoprotein was responsible for this chan ...19979261450
most potential linear b cell epitopes of env glycoproteins of feline immunodeficiency virus are immunogenically silent in infected cats.a battery of sixty-six 20- to 23-amino acid synthetic peptides, partially overlapping by 10-12 amino acids, spanning the entire sequence of the envelope (env) glycoproteins of the petaluma isolate of feline immunodeficiency virus (fiv-pet), has been used to map env linear b cell epitopes. by screening fiv-infected cat sera for anti-peptide reactivity, the existence of two immunodominat domains, namely the v3 region of the surface (su) glycoprotein and the domain including the highly conserved se ...19979282817
parameters of disease progression in long-term experimental feline retrovirus (feline immunodeficiency virus and feline leukemia virus) infections: hematology, clinical chemistry, and lymphocyte subsets.after several years of latency, feline immunodeficiency virus (fiv) and feline leukemia virus (felv) cause fatal disease in the cat. the aim of this study was to determine laboratory parameters characteristic of disease progression which would allow a better description of the asymptomatic phase and a better understanding of the pathogenesis of the two infections. therefore, experimentally infected cats (fiv and/or felv positive) and control animals were observed over a period of 6.5 years under ...19979008278
common mechanism of infection by lentiviruses. 19979024654
proviral organization and sequence analysis of feline immunodeficiency virus isolated from a pallas' cat.the nucleotide sequence and genomic organization have been determined for a highly cytopathic feline immunodeficiency virus (fiv) isolated from a pallas' cat. the 9747-bp provirus of this virus, fiv-oma, has typical lentivirus organization with ltrs, gag, pol, and env open reading frames (orfs), putative vif and rev orfs, and an orf similar to orf2/orfa of domestic cat fiv isolates. although the fiv-oma provirus is 300 to 600 bp longer than other fiv proviruses, these additional bases are distri ...19979024812
detection of fiv antibodies. 19979076928
probing interactions between viral dna and human immunodeficiency virus type 1 integrase using dinucleotides.retroviral integrases are essential for viral replication and represent an attractive chemotherapeutic target. in the current study, we demonstrated the activity of micromolar concentrations of dinucleotides against human immunodeficiency virus type 1 (hiv-1), hiv type 2 (hiv-2), simian immunodeficiency virus, and feline immunodeficiency virus integrases. the structure-activity relationship indicates that 5'-phosphorylation enhances potency and that phosphodiester and sugar modifications affect ...19979106620
infectivity of lion and puma lentiviruses for domestic cats.infection of domestic cats with feline immunodeficiency virus (fiv) causes progressive immunological deterioration similar to that caused by human immunodeficiency virus (hiv). lentiviruses related to but phylogenetically distinct from fiv have been detected in several non-domestic feline species. serological cross-reactivity of these viruses raises the question as to whether inter-species transmission may occur. to address this issue, we asked whether lion lentivirus (fiv-ple) or two strains of ...19979129651
feline immunodeficiency virus causes increased glutamate levels and neuronal loss in brain.feline immunodeficiency virus, like human immunodeficiency virus type 1, is a retrolentivirus causing neurological disease and immune suppression. primary neurological complications, including human immunodeficiency virus encephalopathy and peripheral neuropathy, and neuropathological changes, including gliosis, neuronal injury and multinucleated giant cells, have been described for human immunodeficiency virus type 1 infection. excitatory amino acids have been implicated as a basis for human im ...19979130796
fiv infection of the domestic cat: an animal model for aids. 19979136455
[antithrombin iii activity in health cats and its changes in selected disease].measurements of the antithrombin iii (at iii) activity in feline plasma with a thrombin dependent chromogenic substrate assay using an automatic analyzer showed a high within run precision. the coefficient of variance was 1.82% (normal at iii activity) or 3.19% (decreased at iii activity), respectively. in comparison with the feline pool plasma the at iii activity in canine plasma was similar (93.7%) and in human reference plasma was lower (71.7%). respecting healthy cats aged more than three mo ...19979451844
immunological and histological disorders in cats experimentally infected with feline immunodeficiency virus subtype b (tm2 stain).three conventional cats were experimentally infected with subtype b (tm2 strain) of fiv, and two conventional cats served as controls. the infected cats were examined immunologically 99-176 weeks post fiv inoculation (wpi) and histologically at 130 wpi. two of the three infected cats exhibited lower cd4/cd8 t cell ratios and hypergammaglobulinemia compared with two control cats. further, all the infected cats showed morphological changes in popliteal lymph nodes such as lymphoid depletion, atrop ...19979444068
fractionation of feline bone marrow with the soybean agglutinin lectin yields populations enriched for erythroid and myeloid elements: transplantation of soybean agglutinin-negative cells into lethally irradiated recipients.feline bone marrow cells treated with the soybean agglutinin (sba) lectin are separated into two populations, the agglutinated sba(+) fraction containing predominantly cells of myeloid origin and the nonagglutinated sba(-) fraction consisting of cells primarily of the erythroid lineage. facscan analyses revealed a clear distinction of the cells based on their light scattering properties, i.e., large cells and cells with high granularity were found in the sba(+) fraction, whereas cells having a l ...19979275120
feline immunodeficiency virus (fiv) infection in cats at necropsy: a serological study.sera collected post mortem during a 6-month period from cats were tested for feline immunodeficiency virus (fiv)-specific antibodies by (1) an enzyme-linked immunosorbent assay (elisa), (2) an indirect peroxidase-based immunocytological test (ip), (3) a western immunoblotting (wb) method with fiv-infected cell lysates, and (4) a wb method with purified viral antigen. all four methods were capable of detecting fiv-specific antibodies in haemolysed sera. however, the elisa showed the lowest "posit ...19979179747
serologic reactivity using conserved envelope epitopes in feline lentivirus-infected felids.an enzyme-linked immunosorbent assay (elisa) based on synthetic peptides identical to lentivirus envelope protein amino acid sequences was used to study serologic reactivity of lentivirus-infected domestic cats and nondomestic felids. one feline immunodeficiency virus (fiv) peptide, p237, was consistently recognized by antibodies from fiv-infected cats, but 2 other fiv peptide antigens were not. the molecular basis for this serologic reactivity was examined. lentivirus-infected nondomestic felis ...19979211229
evaluation of commercially available assays of neopterin and beta 2-microglobulin for the assessment of disease progression in fiv-infected cats.serum or plasma samples from cats at different stages of feline immunodeficiency (fiv) infection and from uninfected cats were tested using immunoassays designed to detect human neopterin and beta 2-microglobulin (beta 2m). the results obtained from the anti-human neopterin assay did not correlate with infection status, time post-infection, fcd4 count or clinical picture. feline samples gave negative results in the anti-human beta 2m assay. the assay kits used in this study are not suitable for ...19979220591
molecular characteristics of malignant lymphomas in cats naturally infected with feline immunodeficiency virus.neoplastic disease, especially malignant lymphomas, are often observed in cats infected with feline immunodeficiency virus (fiv). in order to clarify the characteristics of lymphoma cells and to investigate the pathogenesis in fiv-infected cats, we examined the lymphoma tissues developed in five cats naturally infected with fiv by southern blot analyses using feline immunoglobulin (ig), t-cell receptors (tcr) and fiv probes. all of the five cases were serologically positive for anti-fiv antibody ...19979261955
analysis of the genetic diversity and phylogenetic relationship of italian isolates of feline immunodeficiency virus indicates a high prevalence and heterogeneity of subtype b.the genetic diversity of 32 italian isolates of feline immunodeficiency virus (fiv) was studied. isolates were obtained from domestic cats living in different areas. sequence data were obtained from a 308 bp fragment of the p25 region of the gag gene. phylogenetic relationships among these sequences and previously published sequences were determined. all the italian isolates could be assigned to subtype b; however, four isolates formed two separate clusters and may represent genetic outliers. th ...19979292012
a fiv epitope defined by a phage peptide library screened with a monoclonal anti-fiv antibody.phage peptide libraries constitute powerful tools for the mapping of epitopes recognized by monoclonal antibodies. we report here the characterization of an antibody directed against a 20-residue peptide derived from the surface glycoprotein of the feline immunodeficiency virus. the isolation of the wrpdf consensus sequence from a phage display library defined the exact epitope recognized by the mab. compared with known immunogenic peptides of the fiv envelope, it corresponds to the most immunod ...19979419019
alteration of t-cell subsets in the lymph nodes from cats infected with feline immunodeficiency virus.alterations of t-cell subsets in the lymph nodes from fiv-infected cats in various clinical disease stages were examined histologically. in the early stage of infection (ap stage), follicular hyperplasia accompanied by expansion of the paracortical area was observed. follicular involution and depletion with reduced paracortical area was observed in the arc and aids stage nodes. the maximum section area of the entire popliteal lymph node was expanded significantly in the ap nodes. the paracortica ...19979342695
immunopathologic changes in the thymus during the acute stage of experimentally induced feline immunodeficiency virus infection in juvenile cats.the feline thymus is a target organ and site of viral replication during the acute stage of feline immunodeficiency virus (fiv) infection. this was demonstrated by histologic, immunohistologic, flow cytometric, and virologic tests. thymic lesions developed after 28 days postinoculation (p.i.) and included thymitis, premature cortical involution, and medullary b-cell hyperplasia with germinal center formation and epithelial distortion. alterations in thymocyte subsets also developed. fewer cd4+ c ...19979343221
salmonella typhimurium aroa recombinants and immune-stimulating complexes as vaccine candidates for feline immunodeficiency virus.two experimental feline immunodeficiency virus (fiv) vaccines were tested, either alone or in combination, in four groups of cats (a-d). one vaccine (sl3261-fiv) was composed of live attenuated salmonella typhimurium aroa (sl3261) strains expressing the capsid (gag) and part of the envelope (env) proteins of fiv. the other was composed of fiv gag and env proteins incorporated into immune-stimulating complexes (iscom-fiv). cats of group a were immunized four times with sl3261-fiv. cats of group b ...19979400977
relationship of lower urinary tract signs to seropositivity for feline immunodeficiency virus in cats.a group of 41 cats with signs of lower urinary tract disease was compared to a group of 41 cats without any history of disease for prevalence of seropositivity for feline immunodeficiency virus (fiv). the group of healthy cats was similar in age and gender to the group of cats with signs of lower urinary tract disease. three of the cats with lower urinary tract disease and one control cat were seropositive for fiv. this difference was not statistically significant. the most common cause of lower ...19968965266
evaluation of subunit vaccines against feline immunodeficiency virus infection.subunit vaccines prepared against feline immunodeficiency virus (fiv) infection were evaluated in two trials. first, cats were immunized with bacterial expression products of an envelope fragment that contained the v3 neutralization domain of the fiv surface protein fused to either galactokinase (k-su3) or glutathione-s-transferase (g-su3). quantitative and qualitative differences in the humoral immune response were observed with three adjuvants of which quil a was the best in terms of total and ...19968744554
selection and characterization of a mutant of feline immunodeficiency virus resistant to 2',3'-dideoxycytidine.we have selected and plaque purified a mutant of feline immunodeficiency virus (fiv) that is resistant to 2',3'-dideoxycytidine (ddc). this mutant was selected in cultured cells in the continuous presence of 25 microm ddc. the mutant, designated dcr-5c, was fourfold resistant to ddc, threefold resistant to 2',3'-dideoxyinosine, and more than fourfold resistant to phosphonoformic acid. dcr-5c displayed little or no resistance to (-)-beta-2',3'-dideoxy-3'-thiacytidine, 3'-azido-3'-deoxythymidine, ...19968849258
fiv monitoring project. 19968883354
quasispecies and naturally occurring superinfection in feline immunodeficiency virus infection.analysis of individual clones containing the v1 and v2 domains of the segment of the fiv env gene present in a naturally infected cat (t) was carried out. the polymerase chain reaction (pcr) was used to amplify proviral fiv dna extracted from peripheral blood mononuclear cells (pbmcs) obtained in october 1994 from this cat. the pcr products were cloned and the dna sequences determined for 11 clones. sequences obtained were aligned with sequences corresponding to fiv isolates (t90, t91, t92) prev ...19968893792
proficiency testing of selected antigen and antibody tests for use in dogs and cats.to determine the correlation of seroimmunologic test results between reference and nonreference laboratories.19968790539
reduced sensitivity to strain-specific neutralization of laboratory-adapted feline immunodeficiency virus after one passage in vivo: association with amino acid substitutions in the v4 region of the surface glycoprotein. 19968834468
encephalitis associated with giant cells in a cat with naturally occurring feline immunodeficiency virus infection demonstrated by in situ hybridization.this report describes the clinical, pathological, immunocytochemical, and in situ hybridization characteristics of encephalitis associated with feline immunodeficiency virus (fiv) infection in a 4-year-old domestic cat. lesions were identified throughout the brain, affecting the cerebrum, medulla, and cervical spinal cord. perivascular lymphocytic cuffing, gliosis, and white matter vacuolation were most severe in the cerebrum, affecting the white matter and the deep laminae of the grey matter. g ...19968952030
detection of apoptosis induced in peripheral blood lymphocytes from cats infected with feline immunodeficiency virus.peripheral blood lymphocytes (pbl) from cats infected with feline immunodeficiency virus (fiv) were examined for the occurrence of apoptosis after short-term culture. in the pbl from fiv-infected cats, changes in flow-cytometry scattergram, morphological characteristics of apoptosis and nucleosomal dna fragmentation were observed. percentages of apoptotic cells by flowcytometry analysis in pbl from fiv-infected cats (22.4% +/- 9.4%) were significantly higher than those in pbl from uninfected con ...19968893788
comparative properties of feline immunodeficiency virus (fiv) and human immunodeficiency virus type 1 (hiv-1) proteinases prepared by total chemical synthesis.the aspartyl proteinase (pr) encoded by the feline immunodeficiency virus (fiv) was prepared by total chemical synthesis. the 116-amino-acid polypeptide chain was assembled in a stepwise fashion using a boc chemistry solid-phase peptide synthesis approach and subsequently folded into the biologically active dimeric proteinase. the synthetic enzyme showed proteolytic activity against a variety of different peptide substrates corresponding to putative cleavage sites of the gag and gag-pol polyprot ...19968862421
env-specific ctl predominate in cats protected from feline immunodeficiency virus infection by vaccination.animal models of hiv-1 have a key role to play in elucidation of the cellular mechanisms responsible for protective immunity. vaccination of domestic cats with whole inactivated feline immunodeficiency virus (fiv) elicits virus-neutralizing abs and virus-specific ctl in the peripheral blood and lymphoid organs and affords protection from homologous virus challenge. in the present study we confirm the induction of virus-specific ctl following immunization with whole inactivated fiv vaccine and de ...19968871667
prevalence of antibodies to feline parvovirus, calicivirus, herpesvirus, coronavirus, and immunodeficiency virus and of feline leukemia virus antigen and the interrelationship of these viral infections in free-ranging lions in east africa.while viral infections and their impact are well studied in domestic cats, only limited information is available on their occurrence in free-ranging lions. the goals of the present study were (i) to investigate the prevalence of antibodies to feline calicivirus (fcv), herpesvirus (fhv), coronavirus (fcov), parvovirus (fpv), and immunodeficiency virus (fiv) and of feline leukemia virus (felv) antigen in 311 serum samples collected between 1984 and 1991 from lions inhabiting tanzania's national pa ...19968877134
accelerated viremia in cats vaccinated with recombinant vaccinia virus expressing envelope glycoprotein of feline immunodeficiency virus. 19968882329
co-infection of toxoplasma gondii with other pathogens: pathogenicity and chemotherapy in animal models. 19968791703
the value of primate models for studying human immunodeficiency virus pathogenesis.research on human immunodeficiency virus (hiv) infection is compromised by the obvious limitation in having for study only virus-infected individuals or those exposed to the virus. steps involved in transmission or pathogenesis require planned experimentation. the identification of animal models of acquired immunodeficiency syndrome (aids) has therefore been helpful for evaluating phases of hiv pathogenesis. of the seven subgenera of lentiviruses now recognized, two share the characteristics wit ...19968892037
transmission of feline immunodeficiency virus in domestic cats via artificial insemination.the objective of this study was to determine whether semen from male domestic cats infected with feline immunodeficiency virus (fiv) can transmit virus to females. twelve inseminations were performed by an intrauterine laparoscopic technique with fresh or cryopreserved electroejaculates from asymptomatic males chronically infected with the ncsu1 strain of fiv. of six inseminations performed with fresh semen, three resulted in infection of queens, as indicated by seroconversion, expression of fiv ...19968892958
proviral burden and infection kinetics of feline immunodeficiency virus in lymphocyte subsets of blood and lymph node.feline immunodeficiency virus (fiv) is similar to human immunodeficiency virus type 1 virologically and induces a clinical syndrome in cats comparable to human immunodeficiency virus type 1 syndrome in humans. to determine the lymphoid target cells of fiv, populations of cd4+ lymphocytes, cd8+ lymphocytes, and cd21+ lymphocytes (b cells) were enriched to more than 96.5% purity and then analyzed for fiv provirus by semiquantitative dna amplification. we found fiv provirus in cd4+, cd8+, and b lym ...19968764024
genetic diversity of argentine isolates of feline immunodeficiency virus.we report the nucleotide sequence and genetic diversity of part of the envelope (env) gene of four strains of feline immunodeficiency virus (fiv) isolated from argentine domestic cats. the dna encoding the v3 to v5 regions of the env gene of the fiv isolates were amplified by pcr, cloned and sequenced. phylogenetic analysis revealed that the argentine isolates did not cluster into a single group; one isolate clustered with subtype b fiv isolated in the usa and japan, whereas the others formed a ...19968811000
initiation of (-) strand dna synthesis from trna(3lys) on lentiviral rnas: implications of specific hiv-1 rna-trna(3lys) interactions inhibiting primer utilization by retroviral reverse transcriptases.initiation of minus (-) strand dna synthesis was examined on templates containing r, u5, and primer-binding site regions of the human immunodeficiency virus type 1 (hiv-1), feline immunodeficiency virus (fiv), and equine infectious anemia virus (eiav) genomic rna. dna synthesis was initiated from (i) an oligoribonucleotide complementary to the primer-binding sites, (ii) synthetic trna(3lys), and (iii) natural trna(3lys), by the reverse transcriptases of hiv-1, fiv, eiav, simian immunodeficiency ...19968816751
pulmonary and mediastinal metastases of a vaccination-site sarcoma in a cat.sarcomas at vaccination sites in cats were first reported in 1992. recent retrospective studies have confirmed an association between these vaccination-site sarcomas (vss) and feline leukemia virus (felv) and/ or rabies vaccines. in most cases, vss are locally invasive fibrosarcomas that tend to recur but rarely metastasize. we report the mediastinal and pulmonary metastases of a vss in a felv-and feline immunodeficiency virus-negative, 8-year-old, domestic short-haired cat. the primary sarcoma ...19968817854
molecularly cloned feline immunodeficiency virus ncsu1 jsy3 induces immunodeficiency in specific-pathogen-free cats.a full-length feline immunodeficiency virus ncsu1 (fiv-ncsu1) genome (jsy3) was cloned directly from fiv-ncsu1-infected feline cd4+ lymphocyte (fcd4e) genomic dna and identified by pcr amplification with 5' long terminal repeat, gag, env, and 3' long terminal repeat primer sets. supernatant from fcd4e cells cocultured with jsy3-transfected crandell feline kidney (crfk) cells was used as an inoculum. cell-free jsy3 virus was cytopathogenic for fcd4e lymphocytes but did not infect crfk cells in vi ...19968627777
roles of the auxiliary genes and ap-1 binding site in the long terminal repeat of feline immunodeficiency virus in the early stage of infection in cats.to examine the roles of auxiliary genes and the ap-1 binding site in the long terminal repeat of feline immunodeficiency virus (fiv) in vivo, three mutant viruses, which are defective in the vif gene ([delta]vif), orf-a gene (deltaorf-a), and ap-1 binding site (deltaap-1), and wild-type virus as a positive control were separately inoculated into three specific-pathogen-free cats. these cats were assessed by measuring the number of proviral dna copies in peripheral blood mononuclear cells (pbmcs) ...19968970975
neurologic dysfunctions caused by a molecular clone of feline immunodeficiency virus, fiv-ppr.fiv is a lentivirus of domestic cats that causes a spectrum of diseases that is remarkably similar to the clinical syndrome produced by hiv infection in people. both hiv and fiv has been shown to cause neurologic dysfunction. specific pathogen-free (spf) cats were placed into one of three groups: fiv-ppr infected; du-fiv-ppr (a dutpase mutant of the fiv-ppr clone) infected; or an age-matched control group. in both infected groups, the general clinical signs of infection included lymphadenopathy, ...19968972420
a longitudinal study of lymphocyte subsets in a cohort of cats naturally-infected with feline immunodeficiency virus.despite the potential of feline immunodeficiency virus (fiv) as an animal model for human immunodeficiency virus (hiv) studies, the long term effects of naturally-occurring infection have not been determined. hiv infection causes an ongoing deterioration in immune function which directly correlates with disease, in particular acquired immunodeficiency syndrome (aids). however, it is not known whether fiv-induced immunosuppression is progressive or related to the clinical condition. this study ex ...19968893992
persistence of high virus neutralizing antibody titers in cats experimentally infected with feline immunodeficiency virus.the development of virus neutralizing (vn) antibody is one of the most effective host defense mechanisms against virus infection. in the present study, we developed a new vn assay against feline immunodeficiency virus (fiv) using a feline t-lymphoblastoid cell line, mya-1 cells, based on inhibition of viral reverse transcriptase production. this assay is applicable to strains of fiv which can not infect crfk cells. by using the assay, we examined long-term responses of vn antibody in cats experi ...19968898296
does coinfection of bartonella henselae and fiv induce clinical disorders in cats?it was found that bartonella henselae (b. henselae) may induce clinical disorders in cats in natural conditions from a comparison of the serological status for b. henselae with the serostatus for feline immunodeficiency virus (fiv) and several clinical characteristics in 170 domestic cats. seropositivity for b. henselae was not significantly different between fiv antibody-positive and -negative cats (18.4% vs 16.0%). the incidence of clinical characteristics were compared among four cat groups d ...19968908605
quantitation of feline immunodeficiency proviruses in doubly infected cats using competitive pcr and a fluorescence-based rflp.a nested polymerase chain reaction assay, which amplifies a region of the gag gene, was developed for the direct detection of feline immunodeficiency virus (fiv) dna sequences in the blood of infected cats. this method detects as few as ten copies of a plasmid containing the whole genome of the fiv-pet isolate on agarose gel. to distinguish two fiv isolates in double infected cats, we devised an rflp analysis on pcr amplified products exploiting sequence differences in the gag gene of the two st ...19968910645
uveitis in dogs and cats: guidelines for the practitioner.uveitis is a commonly misdiagnosed ophthalmic condition with a wide aetiological base and often the cause cannot be established. uveitis can be associated with systemic diseases like feline infectious peritonitis, feline immunodeficiency virus, feline leukaemia virus, lymphoma, toxoplasmosis and canine ehrlichiosis. the classification and general clinical signs of uveitis are discussed. applicable clinical cases, manifestations and diagnostic methods of the selected diseases are mentioned, and a ...19968786609
parasite prevalence in free-ranging farm cats, felis silvestris catus.no animals tested were positive for feline leukemia virus antigen and chlamydia psittaci antibodies, but all were positive for antibodies to feline calicivirus (fcv), feline herpesvirus 1 (fhv1) and rotavirus. they had antibodies to feline parvovirus (96%), feline coronavirus (84% and cowpox virus (2%). antibody to feline immunodeficiency virus (fiv) was found in 53% of animals, which were less likely to be infected with haemobartonella felis, and had higher fhv antibody titres than cats without ...19968620914
histologic classification and immunophenotype of lymphosarcomas in cats with naturally and experimentally acquired feline immunodeficiency virus infections.lymphosarcoma (malignant lymphoma) is the commonest hematopoietic tumor in the cat. many cases are associated with feline leukemia virus (felv) infection, but epidemiologic and experimental data suggest that feline immunodeficiency virus (fiv) may also have a role in lymphomagenesis. in this paper, we describe the clinical presentation, histologic classification, and immunophenotype of lymphosarcoma in eight domestic cats with natural or experimental fiv infections. the tumors were often of unus ...19968740699
genetic and phylogenetic divergence of feline immunodeficiency virus in the puma (puma concolor).feline immunodeficiency virus (fiv) is a lentivirus which causes an aids-like disease in domestic cats (felis catus). a number of other felid species, including the puma (puma concolor), carry a virus closely related to domestic cat fiv. serological testing revealed the presence of antibodies to fiv in 22% of 434 samples from throughout the geographic range of the puma. fiv-pco pol gene sequences isolated from pumas revealed extensive sequence diversity, greater than has been documented in the d ...19968794304
vaccination protects against in vivo-grown feline immunodeficiency virus even in the absence of detectable neutralizing antibodies.so far, vaccination experiments against feline immunodeficiency virus have used in vitro-grown virus to challenge the vaccinated hosts. in this study, cats were vaccinated with fixed feline immunodeficiency virus-infected cells and challenged with plasma obtained from cats infected with the homologous virus diluted to contain 10 cat 50% infectious doses. as judged by virus culture, pcrs, and serological analyses performed over an 18-month period after the challenge, all of the vaccinated cats we ...19968523581
comparative study of the cell tropism of feline immunodeficiency virus isolates of subtypes a, b and d classified on the basis of the env gene v3-v5 sequence.feline immunodeficiency virus (fiv) isolates have been classified into subtypes a, b, c and d based on the env gene v3-v5 sequence. the cell tropism of seven new japanese isolates and a petaluma (prototype) isolate of fiv, which classified into subtypes a, b and d, for feline lymphoblastoid and feline fibroblastoid cell lines was compared. fet-1 (cd4+/-, cd8-, and cd9+2) and kumi-1 (cd4+2, cd8- and cd9+2) cells were used as the interleukin-2 (il-2)-dependent feline t-lymphocyte cell lines and fe ...19968558132
influence of orf2 on host cell tropism of feline immunodeficiency virus.feline immunodeficiency virus (fiv) is a lentivirus associated with an immunodeficiency syndrome of the domestic cat. a short open reading frame (orf2), of unknown function, is present in all fiv isolates. we have investigated the role of orf2 in determining the cell tropism of two infectious molecular clones of fiv. fiv-ppr is able to productively infect feline peripheral blood leukocytes (pbls) and a t lymphocyte cell line (mch5-4), but not a feline astrocyte cell line (g355-5) or crandell fel ...19968553580
the mutation frequency of feline immunodeficiency virus enhanced by 3'-azido-3'-deoxythymidine.we have developed a host range system to measure the mutation frequency of feline immunodeficiency virus (fiv), the feline homologue of human immunodeficiency virus type 1 (hiv-1). when wild-type fiv was grown in the presence of a known mutagen, 5-bromo-2'-deoxyuridine (budr), a dose-dependent increase of host range mutants was detected. using this system, we have evaluated the effects of antiviral drugs upon the mutation frequency of fiv. subinhibitory concentrations of 3'-azido-3'-deoxythymidi ...19968624757
neutralization sensitivity and accessibility of continuous b cell epitopes of the feline immunodeficiency virus envelope.antibodies elicited during natural infection of domestic cats by the feline immunodeficiency virus (fiv) recognize continuous epitopes in nine domains of the virus envelope glycoproteins. whereas antibodies directed against the v3 envelope region can neutralize laboratory-adapted virus, neutralization of fiv has been shown to depend upon cellular substrate, and virus adaptation to laboratory cell lines may alter sensitivity to neutralizing antibodies. we therefore undertook a systematic analysis ...19968627265
synthesis and targeted delivery of an azidothymidine homodinucleotide conferring protection to macrophages against retroviral infection.the infectivity and replication of human (hiv-1), feline (fiv), and murine (lp-bm5) immunodeficiency viruses are all inhibited by several nucleoside analogues after intracellular conversion to their triphosphorylated derivatives. at the cellular level, the main problems in the use of these drugs concern their limited phosphorylation in some cells (e.g., macrophages) and the cytotoxic side effects of nucleoside analogue triphosphates. to overcome these limitations a new nucleoside analogue homodi ...19968633079
plasma viral rna load predicts disease progression in accelerated feline immunodeficiency virus infection.viral rna load has been shown to indicate disease stage and predict the rapidity of disease progression in human immunodeficiency virus type 1 (hiv-1)-infected individuals. we had previously demonstrated that feline immunodeficiency virus (fiv) rna levels in plasma correlate with disease stage in infected cats. here we expand upon those observations by demonstrating that plasma virus load is 1 to 2 logs higher in cats with rapidly progressive fiv disease than in long-term survivors. differences ...19968642679
coccidioidomycosis in 48 cats: a retrospective study (1984-1993)coccidioidomycosis was diagnosed in 48 cats. forty-one cases were identified within a period of 3 years. coccidioides immitis was revealed by cytological or histopathological examinations, or culture in 70% of cats. the remaining 30% of cases were diagnosed by appropriate clinical signs, radiographic lesions, and serological test results. the average age of affected cats was 6.2 years with a median age of 5.0 years. fifty-four percent (n = 26) were female and 46% (n = 22) were male. domestic sho ...19957760314
regional distribution of lesions in the central nervous system of cats infected with feline immunodeficiency virus.neuropathological examination of the central nervous system of 13 naturally and 13 experimentally feline immunodeficiency virus (fiv)-infected cats revealed diffuse gliosis of gray and white matter and vacuolar myelinopathy in a large proportion of infected animals, sometimes associated with lymphocytic meningitis. multinucleated giant cell formation, the hallmark of multifocal giant cell encephalitis in hiv infection, was never observed. morphometric analysis confirmed a marked increase of gfap ...19958573382
seroepidemiological survey of feline retrovirus infections in cats in taiwan in 1993 and 1994.in order to investigate the prevalence of infections with three feline retroviruses feline immunodeficiency virus (fiv), feline leukemia virus (felv) and feline syncytial virus (fsv) in taiwan, we collected a total of 75 blood samples from cats from veterinary hospitals, a breeding cattery and a homeless shelter in 1993 and 1994. we examined the presences of anti-fiv and fsv antibodies and felv-p27 antigen in these samples by the indirect immunofluorescence and/or enzyme-linked immunosorbent ass ...19957756412
variable expression of major histocompatibility complex class ii in the domestic cat.this paper describes the characterisation of six independently produced monoclonal antibodies (mabs) specific for non-polymorphic determinants of feline major histocompatibility complex (mhc) class ii. one mab is an anti-sheep class ii which cross-reacts with the cat and five have been produced in response to immunisation with purified feline immunodeficiency virus. despite their independent source all the mabs have identical reactivities, immunoprecipitating two complex groups of polypeptides o ...19958588090
[findings in the eyes of serologically fiv (feline immunodeficiency virus) positive cats].the findings in the eyes of 19 serologically fiv-positive cats in the terminal stage of the disease were compared to those in 23 serologically fiv-negative cats. an inflammation of iris and ciliary body was more common in the fiv-group than in the other cats and could be seen in 16 out of 19 serologically fiv-positive cats. in most cases a diffuse infiltration of both lymphocytes and plasma cells could be observed. there were only few signs of acute inflammation in the posterior segment. degener ...19958591769
molecular interactions between retroviruses and herpesviruses.human and animal herpesviruses are able to stimulate gene expression of various human and animal retroviruses and the activation appears to be a common theme. it is of interest why the retroviruses can be commonly activated by herpesviruses despite clear diversities in each mechanism for retrovirus gene expression. in this review, three typical examples of the interactions; human immunodeficiency virus and human herpesviruses, avian retroviruses and marek's disease virus, and feline immunodefici ...19958593284
systemic diseases with cutaneous manifestations.the purpose of this article is to briefly discuss the following cutaneous manifestations of selected systemic diseases: poxvirus; feline leukemia virus (felv); feline immunodeficiency virus (fiv); herpesvirus; calcivirus; pseudorabies; plague; tularemia; toxoplasmosis; leishmania; hypothyroidism; hyperthyroidism; hyperadrenocorticism; diabetes mellitus; acromegaly; thallium poisoning; pancreatic disease; hypereosinophilic syndrome; mucopolysaccharidosis; and pansteatitis. recognition of these cu ...19958525575
breaking the shackles of the genetic code: engineering retroviral proteases through total chemical synthesis. 19958540353
molecular modeling of the structure of fiv protease. 19958540361
nucleotide sequence of feline immunodeficiency virus: classification of japanese isolates into two subtypes which are distinct from non-japanese subtypes.seven isolates of feline immunodeficiency virus (fiv), shizuoka, yokohama, sendai-1, sendai-2, fukuoka, aomori-1, and aomori-2, were isolated from fiv-seropositive domestic cats in japan, and their proviral dnas were amplified by pcr. the nucleotide sequences of their env and gag genes were determined and compared with those of previously described isolates: u.s. and european isolates and one japanese isolate, tm2. phylogenetic analyses of complete env gene sequences demonstrate that worldwide i ...19957745712
involvement of gag- and env-specific cytotoxic t lymphocytes in protective immunity to feline immunodeficiency virus.definition of the immunological mechanisms involved in protective immunity against lentiviral infections is crucial to the development of an effective vaccine. the induction of gag- and env-specific cell-mediated immune responses was studied in cats following vaccination with whole inactivated feline immunodeficiency virus (fiv). cats were immunized by inoculation with three doses of paraformaldehyde-inactivated fiv, derived from the feline lymphoid cell line, fl-4, which is persistently infecte ...19958554908
dehydroepiandrosterone inhibits replication of feline immunodeficiency virus in chronically infected cells.dehydroepiandrosterone (dhea) is a steroid hormone produced by the adrenal cortex that serves as an intermediary in sex steroid synthesis. dhea is produced in abundance by humans and most other warm-blooded animals. based upon previous reports demonstrating the antiviral and immunostimulatory activities of dhea and dhea-sulfate (dheas) we sought to determine whether introduction of these compounds would affect replication of feline immunodeficiency virus (fiv) in chronically infected cells. when ...19957542411
development of monoclonal antibodies and capture immunoassays for feline immunodeficiency virus.we generated monoclonal antibodies (mab) against feline immunodeficiency virus (fiv) and characterized these mab by single competition enzyme immunoassays (eia), immunoblot analysis, and radioimmunoprecipitation. four mab identified 3 distinct epitopes of the fiv p24/26 gag major core protein. one mab recognized the p16/17 gag protein; none recognized envelope proteins. we developed an fiv p26 antigen capture eia that proved more sensitive (0.5 ng of p26/ml), less expensive, and less time-consum ...19957544555
quantification of feline immunodeficiency virus (fiv) proviral dna in peripheral blood mononuclear cells of cats infected with japanese strains of fiv.the polymerase chain reaction (pcr) method was applied for measurement of the proviral dna copy number of feline immunodeficiency virus (fiv) in peripheral blood mononuclear cells (pbmc) of cats experimentally and naturally infected with fiv. in experimentally infected cats except one cat infected with the petaluma strain, fiv-specific dnas were efficiently amplified with the pcr method under the conditions used in this study. in the naturally fiv-infected cats, the specific dnas were also ampli ...19957548402
recombinant felv vaccine: long-term protection and effect on course and outcome of fiv infection.the efficacy and the long-term protection of a recombinant feline leukemia virus (felv) vaccine were determined in 30 specified pathogen free cats for over 3 years. at the same time, in order to specify the effects of feline immunodeficiency virus (fiv) on the immune system, one half of the cats (n = 15) were previously infected with the swiss isolate fiv zurich 2. the second half of the animals (n = 15) served as non-infected controls. eighteen (nine fiv-negative, nine fiv-positive) vaccinated ...19957618252
evaluation of an autologous red cell agglutination test, vetred fiv, for the presence of fiv antibody in cats.a commercially available whole blood agglutination test, vetred fiv, used for the detection of antibodies to feline immunodeficiency virus (fiv), was evaluated. the test is based on the use of a synthetic peptide conjugated to a non-agglutinating anti-feline red blood cell monoclonal antibody. the amino acid sequence of the synthetic peptide was derived from the predicted sequence of the transmembrane protein of fiv. the sensitivity and specificity of vetred fiv was 100% when 34 known fiv-positi ...19957618263
tumor necrosis factor-alpha responses are depressed and interleukin-6 responses unaltered in feline immunodeficiency virus infected cats.feline immunodeficiency virus (fiv), a lentivirus similar to hiv, causes an acquired immunodeficiency syndrome in cats. similar to human immunodeficiency virus (hiv), the pathogenesis of fiv is associated with dysregulation of the cytokine network. while alterations in tumor necrosis factor-alpha (tnf-alpha) and interleukin-6 (il-6) expression have been reported in hiv-infected patients, changes attributable to hiv and those caused by cofactors such as secondary infections cannot always be readi ...19957618260
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