| serological definition of the lentivirus group of retroviruses. | the major polypeptides of visna viruses and other lentiviruses have been isolated and shown to be closely related if not identical in radioimmunoassays. by this criterion the lentiviruses form a distinct group of retroviruses unrelated to spuma viruses, mammalian and avian retroviruses that cause tumors, and unclassified retroviruses of cattle and horses. two sera obtained from goats immunized with mason-pfizer monkey virus or squirrel monkey virus reacted with visna p30. additional data suggest ... | 1979 | 85722 |
| characterization of early pathogenic effects after experimental infection of calves with bovine immunodeficiency-like virus. | the early pathogenic effects of bovine immunodeficiency-like virus (biv) were studied in calves experimentally inoculated with biv. all animals inoculated with biv r29-infected cells seroconverted by 6 weeks postinoculation, and biv was recoverable from each animal at 2 weeks postinoculation. however, levels of biv replication in vivo appeared to be low. in situ hybridization studies indicated that during peak periods of viral replication in vivo, less than 0.03% of peripheral blood mononuclear ... | 1992 | 1309889 |
| regulation of gene expression directed by the long terminal repeat of the feline immunodeficiency virus. | the long terminal repeat (ltr) of a retrovirus contains sequence elements that constitute a promoter for controlling viral gene expression in infected cells. we have examined regulation of ltr-directed gene expression in feline immunodeficiency virus (fiv), a t-lymphocytopathic lentivirus associated with a fatal aids-like disease in domestic cats. two independent virus isolates, designated fiv-petaluma and fiv-ppr, have been molecularly cloned and show greater than 85% sequence homology. both cl ... | 1992 | 1310554 |
| activation of bovine immunodeficiency-like virus expression by bovine herpesvirus type 1. | bovine immunodeficiency-like virus (biv) is a recently identified lentivirus that infects cattle. the virus has structural and genetic similarities to human hiv. the present study demonstrates that biv can be activated by bovine herpesvirus type 1 (bhv-1), a pathogen frequently associated with cattle diseases. activation of biv expression can be detected as increased biv reverse transcriptase activity, increased in the number of syncytia induced by biv, and increased in the steady state level of ... | 1992 | 1312280 |
| conservation of amino-acid sequence motifs in lentivirus vif proteins. | the nonstructural/regulatory genes of human immunodeficiency virus type 1 (hiv-1) and other lentiviruses are believed to play an important role in the replication and pathogenesis of these viruses. in hiv-1 and other lentiviruses, the vif (viral infectivity factor) open reading frame (orf) (also termed sor or q in some lentivirus genomes) is located in the central region, overlapping the 3' end of the pol orf, but in a different reading frame. among the lentiviruses, only equine infectious anemi ... | 1992 | 1312756 |
| infection of rabbits with bovine immunodeficiency-like virus. | new zealand white rabbits, which had been prepared for inoculation by intraperitoneal treatment with thioglycollate, were inoculated intraperitoneally with bovine immunodeficiency-like virus (biv). infected materials from various sources were used including cultured cells and culture fluids, peripheral blood leukocytes from infected cattle and spleen tissue from previously infected rabbits. virus isolations and serological responses detected by western blotting provided clear evidence that infec ... | 1992 | 1313619 |
| bovine immunodeficiency-like virus encodes factors which trans activate the long terminal repeat. | lentiviruses are known to encode factors which trans activate expression from the viral long terminal repeat (ltr); the primary trans activator is the tat gene product. one of the putative accessory genes (tat) of the bovine immunodeficiency-like virus (biv) bears sequence similarity to other lentivirus tat genes. this finding suggests that biv may encode a trans-activating protein capable of stimulating ltr-directed gene expression. to test this hypothesis in vitro, biv ltr-chloramphenicol acet ... | 1992 | 1313891 |
| transmembrane protein oligomers of caprine arthritis-encephalitis lentivirus are immunodominant in goats with progressive arthritis. | to dissect mechanisms of caprine arthritis-encephalitis lentivirus-induced arthritis, an undefined immunodominant viral glycoprotein, gp90 (g. c. johnson, a. f. barbet, p. klevjer-anderson, and t. c. mcguire, infect. immun. 41:657-665, 1983), was characterized. monoclonal antibody to gp90 and specific antiserum to env gene products demonstrated that gp90 was a transmembrane protein (tm) dimer. goats with progressive arthritis had high antibody titers to oligomeric and monomeric (38-kda) tm. | 1992 | 1313930 |
| detection of antibodies to ovine lentivirus using a recombinant antigen derived from the env gene. | the western blot assay was performed to characterize antibodies to the transmembrane glycoprotein (tgp) of ovine progressive pneumonia virus (oppv) by using glutathione-s-transferase-tgp (gst-tgp) protein. the gst-tgp protein was efficiently expressed in escherichia coli (e. coli) and was highly immunoreactive in the western blot assay. this assay detected antibodies in 97% (103/106) of the sera from agarose gel immunodiffusion (agid) positive opp animals. like human aids patients, antibodies to ... | 1992 | 1314572 |
| prevalence of antibody to caprine arthritis-encephalitis virus in goats in the united states. | goats from 28 states were tested for antibodies to caprine arthritis-encephalitis virus. of 3,790 goats, 1,175 (31%) tested positive, and of 196 herds tested, 143 (73%) had 1 or more seropositive members. this prevalence, based on serum samples from all goats in the participating herds, was lower than most rates reported in other studies. such studies were based on fewer samples, incomplete sampling of herds, or smaller geographic base. prevalence was highest in western pacific and northern plai ... | 1992 | 1314795 |
| a comparison of regulatory features in primate lentiviruses. | historically, research into the regulation of gene expression in primate lentiviruses has focused on human immunodeficiency virus type 1 (hiv-1), the primary cause of acquired immunodeficiency syndrome (aids) in humans. the increasing emergence of hiv-2 as a human pathogen, and the importance of the various simian immunodeficiency viruses (siv) as models for the treatment and prevention of hiv-1-induced disease, suggest that an understanding of gene regulation in these related viruses will becom ... | 1992 | 1315144 |
| examination of whether persistently indeterminate human immunodeficiency virus type 1 western immunoblot reactions are due to serological reactivity with bovine immunodeficiency-like virus. | the bovine lentivirus, known as bovine immunodeficiency-like virus (biv), is genetically, structurally, and antigenically related to human immunodeficiency virus type 1 (hiv-1). it is not known whether sera from persons exposed to biv proteins would show either positive or indeterminate reactivity on hiv-1 antibody tests. we used a biv western blot (immunoblot) analysis to examine human sera characterized as hiv-1 antibody positive, hiv-1 antibody negative, hiv-1 persistently indeterminate, hiv- ... | 1992 | 1315332 |
| genomic variation and segregation of equine infectious anemia virus during acute infection. | equine infectious anemia virus (eiav) is a lentivirus that infects and persists in the monocyte/macrophage populations of blood and tissues. we employed polymerase chain reaction to investigate the distribution and the level of genome variability of eiav dna in different tissues of a horse infected with a highly virulent variant of the wyoming strain of the virus. long terminal repeat, gag, and pol primer pairs were used to direct the amplification of eiav dna from the peripheral blood mononucle ... | 1992 | 1316487 |
| molecular mechanisms of visna virus tat: identification of the targets for transcriptional activation and evidence for a post-transcriptional effect. | visna virus is a pathogenic lentivirus of sheep that is distantly related to the primate lentiviruses, including the human immunodeficiency virus type 1 (hiv-1). replication of hiv-1 in cell culture requires the expression of a virus-encoded protein, tat, which is a potent trans-activator of viral gene expression. visna virus encodes an analogous tat protein that greatly increases gene expression directed by the visna viral ltr. this report uses a stable vero cell line that constitutively expres ... | 1992 | 1316669 |
| cpf-dd is an inhibitor of infection by human immunodeficiency virus and other enveloped viruses in vitro. | the initial step in the infection cycle of human immunodeficiency virus type 1 (hiv-1) involves binding of its surface glycoprotein gp 120 to the t lymphocyte cd4 antigen. cpf-dd is a low molecular weight inhibitor of hiv infectivity that inhibits gp 120 binding to cd4 in vitro (finberg et al., science 249, 287-291, 1990). we find, however, that the actions of cpf-dd are not limited to its ability to interfere with gp 120-cd4 binding; its predominant action is to remove the viral envelope from t ... | 1992 | 1316672 |
| evidence for a lentiviral etiology in an epizootic of immune deficiency and lymphoma in stump-tailed macaques (macaca arctoides). | a retrospective study determined that an epizootic of immune suppression and lymphoma in stump-tailed macaques (macaca arctoides) that began in 1976 was associated with a horizontally spread lentivirus infection. this conclusion was based on serology, epidemiology, pathology, and virus isolation. the lesions found in the stump-tailed macaques were more compatible with lesions seen in siv-infected rhesus than those seen in rhesus macaques infected with type d retroviruses. a lentivirus, isolated ... | 1992 | 1318381 |
| persistent infection of rabbits with bovine immunodeficiency-like virus. | chronic infection of rabbits was induced by a single intraperitoneal injection of bovine immunodeficiency-like virus (biv)-infected cells. ten biv-infected animals were monitored serologically for up to 2 years. results of serologic and virus rescue assays indicated that all animals became infected and demonstrated a rapid and sustained biv-specific humoral response. biv was rescued by cocultivation from spleen, lymph nodes, and peripheral blood leukocytes of infected animals. viral dna in immun ... | 1992 | 1318416 |
| defective viral particles in caprine arthritis encephalitis virus infection. | attempts to isolate full-length unintegrated circular forms of the caprine arthritis encephalitis virus (caev) genome yielded only a large number of molecules with deletions. the 3' borders of most of these deletions were near the u3 region of the long terminal repeat whereas the 5' edges were found at various upstream sites within pol or env. with one exception, gag sequences were always present. analysis of molecular clones derived from integrated proviral caev genomes from the same infected c ... | 1992 | 1318611 |
| production of feline immunodeficiency virus in feline and non-feline non-lymphoid cell lines by transfection of an infectious molecular clone. | an infectious molecular clone of the tm1 strain of feline immunodeficiency virus (fiv) was transfected into each of one feline (crfk), two simian (cos and vero) and two human (sw480 and hela) non-lymphoid cell lines, and virus production was assayed on feline t lymphoblastoid mya-1 cells by monitoring reverse transcriptase activity. infectious virus was produced in crfk, vero and hela cells, but not in cos and sw480 cells. when the basal promoter activity of the fiv long terminal repeat (ltr) wa ... | 1992 | 1318947 |
| lentivirus induced arthritis in animals. | retroviral arthritis in sheep and goats depends on persistent infection in the animals. virus is latent in macrophage precursor cells and viral replication is initiated when these cells are induced to differentiate. antiviral antibodies and cytokines modulate the efficiency of viral gene product expression. specific cytokines induced during replication of the lentivirus in mononuclear cells are also responsible for directing infected cells from peripheral blood through the vascular endothelium t ... | 1992 | 1319487 |
| comparison of early and late feline immunodeficiency virus encephalopathies. | the study of the early and late stages of encephalopathy following infection by the feline immunodeficiency virus (fiv) was carried out with laboratory and naturally infected cats. | 1992 | 1319717 |
| seroprevalence of bovine immunodeficiency-like virus and bovine leukemia virus in a dairy cattle herd. | to determine the prevalence of single vs. dual infection with bovine immunodeficiency virus (biv) and bovine leukemia virus (blv), sera (n = 95) from a dairy cattle herd were analyzed for anti-biv and anti-blv antibodies by an enzyme linked immunosorbent assay. twenty-one percent (20/95) of samples were biv-seropositive, while 52% (49/95) of the same samples were blv-seropositive. a significantly greater percentage of biv-seronegative samples were blv-seropositive, 57% (43/75), than were biv-ser ... | 1992 | 1320785 |
| seroprevalence of ovine progressive pneumonia virus in sheep in the united states as assessed by analyses of voluntarily submitted samples. | ovine progressive pneumonia (opp) is a lentivirus-induced disease of sheep in the united states that is similar, if not identical, to maedi/visna in many other countries. prevalence estimates of seropositivity to this virus in sheep in the united states have been confined to limited groups or flocks of sheep and have varied from 1 to 90%. in this study of detection of antibodies against opp virus, we found a lower general prevalence of antibodies to opp virus in sheep than was previously reporte ... | 1992 | 1320816 |
| [cerebral glioblastoma: a new complication of hiv-1 infection]. | a new case of supratentorial malignant glioma is reported in an hiv-1 infected male homosexual. tumours of the nervous system account for only 5 to 10 percent of neurological complications of aids, and most of them are lymphomas or metastases from kaposi's sarcomas. in fact, hiv-1 is a neurotropic lentivirus, not transforming by definition. our patient had a frontal tumoral syndrome resistant to the conventional anti-toxoplasmic treatment. pathological examination of a tumoral fragment obtained ... | 1992 | 1322536 |
| analysis of a human immunodeficiency virus type 1 isolate carrying a truncated transmembrane glycoprotein. | we have recently reported the isolation of a human immunodeficiency virus type 1 (hiv-1), kb-1gp32 carrying a shorter size (32 kda) of transmembrane glycoprotein (tmp) from tall-1 cells persistently infected with kb-1gp41 virus strain (shimizu et al., 1990a). endoglycosidase treatments showed that the different size of the tmp between the two strains was due to a truncation of 9 kda of polypeptide in the kb-1gp32 tmp coding region. sequence analysis revealed the substitution of a cag codon to a ... | 1992 | 1322587 |
| identification and subcellular localization of the q gene product of visna virus. | the genome of the sheep visna lentivirus contains an open reading frame, q, which has a coding potential of 230 amino acid residues. this paper reports the identification and the subcellular localization of the q orf-encoded protein detected in lysates of visna virus-infected sheep choroid plexus cells. sera from sheep either experimentally or naturally infected with visna virus reacted with the bacterially synthesized q protein indicating that the in vivo expressed q product is immunogenic. ant ... | 1992 | 1322597 |
| detection of salivary antibodies in cats infected with feline immunodeficiency virus. | the saliva of cats infected with feline immunodeficiency virus was examined for total immunoglobulin content and antiviral antibodies. seropositive cats showed an increase in salivary immunoglobulin g levels, which was only partly attributable to the enhanced prevalence of oral inflammatory lesions, compared with the levels in seronegative cats. immunoglobulin g, but not immunoglobulin m, levels in serum were also increased. salivary antibodies were determined by indirect immunofluorescence and ... | 1992 | 1323574 |
| effects of virus load in the pathogenesis of lentivirus-induced lymphoid interstitial pneumonia. | to better define the relationship between ovine lentivirus (ovlv) infection and respiratory disease, pulmonary leukocytes and postmortem lung specimens from 42 sheep seropositive or at risk for ovlv infection were obtained. the lungs were examined for lesions of lymphoid interstitial pneumonia (lip), and animals were categorized into five groups by severity of lip and ovlv serologic status. the presence of ovlv in alveolar macrophages was established by proviral dna amplification using the polym ... | 1992 | 1323619 |
| induction of feline immunodeficiency virus-specific cytolytic t-cell responses from experimentally infected cats. | we have examined the in vitro induction and activity of feline immunodeficiency virus (fiv)-specific cytolytic t cells obtained from cats experimentally infected for 7 to 17 weeks or 20 to 22 months with the petaluma isolate of fiv. normal or fiv-infected autologous and allogeneic t lymphoblastoid cells were used as target cells in chromium-51 or indium-111 release assays. when effector cells consisted of either fresh peripheral blood mononuclear cells or concanavalin a- and interleukin-2-stimul ... | 1992 | 1323704 |
| evolution of the primate lentiviruses: evidence from vpx and vpr. | the genomes of the four primate lentiviral groups are complex and contain several regulatory or accessory genes. two of these genes, vpr and vpx, are found in various combinations within the four groups and encode proteins whose functions have yet to be elucidated. comparison of the encoded protein sequences suggests that the vpx gene within the hiv-2 group arose by the duplication of an ancestral vpr gene within this group. evolutionary distance analysis showed that both genes were well conserv ... | 1992 | 1324171 |
| major core proteins, p24s, of human, simian, and feline immunodeficiency viruses are partly expressed on the surface of the virus-infected cells. | we have previously shown the expression of human immunodeficiency virus type 1 (hiv-1) major gag protein, p24, on the surface of persistently hiv-1-infected cells by using murine monoclonal antibodies (mab). we now report that the cell surface gag p24 antigen expression is a universal phenomenon among hiv-1, simian immunodeficiency virus (siv), and feline immunodeficiency virus (fiv). the mabs prepared by immunization with purified hiv-1 particles were used as antibodies cross-reactive to hiv-1 ... | 1992 | 1326145 |
| origins of genes: "big bang" or continuous creation? | many protein families are common to all cellular organisms, indicating that many genes have ancient origins. genetic variation is mostly attributed to processes such as mutation, duplication, and rearrangement of ancient modules. thus it is widely assumed that much of present-day genetic diversity can be traced by common ancestry to a molecular "big bang." a rarely considered alternative is that proteins may arise continuously de novo. one mechanism of generating different coding sequences is by ... | 1992 | 1329098 |
| [alveolar lymphocyte subsets and their state of activation during the course of interstitial pneumonia of sheep induced by the visna-maedi lentivirus]. | | 1992 | 1329603 |
| [the lymphocytes of the milk of ewes infected by the maedi-caev virus at the moment of lambing]. | | 1992 | 1329606 |
| bovine immunodeficiency virus. | | 1992 | 1329846 |
| feline immunodeficiency virus: a brief review. | feline immunodeficiency virus (fiv), previously known as feline t-lymphotropic lentivirus (ftlv), was first described by pedersen et al. (1987) who isolated the virus from cats with a variety of clinical signs suggestive of immunodeficiency. since then fiv has become one of the most studied feline viruses, not least because of its similarity to human immunodeficiency viruses (hiv) which cause acquired immunodeficiency syndrome (aids) in man. | 1992 | 1330201 |
| evaluation of an enzyme-linked immunosorbent assay for the detection of antibodies to caprine arthritis-encephalitis virus in goat serum. | an indirect enzyme-linked immunosorbent assay (elisa), was evaluated for its ability to detect serum antibodies against caprine arthritis-encephalitis virus (caev). the elisa was compared to three other serological immunoassays, agar gel immunodiffusion test (agidt), immunoblot assay (iba), and a fixed-cell immunoperoxidase assay (fcipa). a total of 511 samples, from 40 farms representing a variety of goat breeds and ages were tested. an estimate of the elisa sensitivity and specificity was made ... | 1992 | 1330278 |
| mls genes and self-superantigens. | the mls gene products, which have long been known for their potent t-cell stimulatory function, have recently come of age through two pivotal discoveries, revealing that they act as superantigens and originate from retroviruses. in addition, recent experiments suggest that two retroviruses, the murine b-type mammary tumor virus and the human lentivirus hiv, make use of the t-cell stimulatory capacity of a virally encoded superantigen for facilitating viral replication. | 1992 | 1332231 |
| no evidence of vertical transmission of naturally acquired feline immunodeficiency virus infection. | a naturally occurring feline immunodeficiency virus (fiv) infection in a closed breeding colony of cats, was studied for a period of 9 months. the colony consisted of 25 adult cats, of which six proved to be infected with fiv as judged by serological examination and virus isolation. in all, 48 kittens were monitored for levels of antibodies against fiv during their first 6 months of life. all the kittens (n = 30) born of fiv-infected queens showed maternal antibodies against fiv, although these ... | 1992 | 1332250 |
| detection of ovine lentivirus in seronegative sheep by in situ hybridization, pcr, and cocultivation with susceptible cells. | serological surveys for ovine lentivirus (ovlv), a worldwide cause of pneumonia and chronic debilitation in sheep, have demonstrated a wide range of seroprevalence rates. this study analyzed ovlv infection in a purebred sheep flock with a history of ovlv disease (flock 1), and compared the prevalence with that of a flock lacking previous ovlv-associated disease (flock 2). serological tests (elisa and western blot assay) indicated that 25% of sheep of all ages in flock 1 (group a) and 33% of anim ... | 1992 | 1333379 |
| analysis of ovine lentivirus infectivity and replication by using a focal immunoassay and an antigen-capture enzyme-linked immunosorbent assay. | a focal immunoassay and an antigen-capture enzyme-linked immunosorbent assay (antigen-capture elisa) were developed to quantify infectious ovine lentivirus (ovlv) and ovlv capsid protein (ca) (p27), respectively. the in vitro kinetics of replication and cytopathogenicity of distinct biological clones of ovlv (rapid/high and slow/low phenotypic variants) were assessed. both viruses were detected by focal immunoassay within 48 h postinfection, 2 days before syncytia were observed in goat synovial ... | 1992 | 1333481 |
| infection and dysfunction of monocytes induced by experimental inoculation of calves with bovine immunodeficiency-like virus. | three calves were experimentally inoculated with bovine immunodeficiency-like virus (biv) to examine biv pathogenesis. inoculated calves produced specific antibody that could be detected from 3 to 5 weeks up to 1 year postinoculation (pi). virus was isolated from peripheral blood mononuclear cells (pbmc) 3-4 weeks pi by syncytia assay. thereafter, the virus could be continually isolated. biv could be isolated from monocytes but not from t cells. likewise, monocytes could be infected with biv in ... | 1992 | 1333528 |
| 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 |
| caprine arthritis-encephalitis control in france. | | 1992 | 1335189 |
| computer analysis of the amino acid sequences in gp41 of apathogenic african green monkey (agm) virus, less pathogenic hiv-2 and highly pathogenic siv and hiv-1 lentiviruses. | the bestfit computer program was used to compare the amino acid sequence of the gp160 envelope glycoprotein of an apathogenic agm and the pathogenic sivagm monkey lentiviruses. it was found that the gp120 envelope glycoproteins of these viruses resembled each other in their functional domains. however, an insert of 40 amino acids was found in the gp41 envelope glycoproteins of the pathogenic sivagm virus in the amino acid sequence between the membrane anchoring sequence and the carboxyterminus. ... | 1992 | 1335629 |
| cohort study of natural transmission and two methods for control of caprine arthritis-encephalitis virus infection in goats on a california dairy. | a prospective observational cohort study of 361 dairy goat kids was conducted to compare 2 methods of controlling caprine arthritis-encephalitis virus infection under commercial dairy conditions. to compare effectiveness of feeding kids pasteurized milk vs serologic testing and segregation in addition to pasteurized milk feeding, goats were monitored up to the age of 30 months by use of monthly agar gel immunodiffusion testing. survival analysis methods were used to determine whether age at sero ... | 1992 | 1335709 |
| risk factors associated with the incidence of seroconversion to caprine arthritis-encephalitis virus in goats on california dairies. | incidence of seroconversion to caprine arthritis-encephalitis virus (caev) was determined for 1,194 goats on 11 dairies, using 2 repeated annual herd tests for caev. current life table methods were used to compare age-specific incidence of seroconversion for pasteurized milk-raised and unpasteurized milk-raised goats. logistic regression models were used to determine the risk factors associated with caev seroconversion, and to estimate odds ratios for seroconversion for various factor levels. go ... | 1992 | 1335710 |
| detection of multiple retroviral infections in cattle and cross-reactivity of bovine immunodeficiency-like virus and human immunodeficiency virus type 1 proteins using bovine and human sera in a western blot assay. | bovine antibovine immunodeficiency-like virus (biv) antibodies were detected by western blot analysis (wba) using a chemiluminescence protocol. bovine sera with anti-biv activity, obtained from cows in two dairy herds, had antibodies directed against a variety of biv-specific antigens indicating chronic infections. these sera were also tested for serological reactivity against bovine leukemia virus (blv) and bovine syncytial virus (bsv). cows most commonly had anti-bsv antibodies (12 of 39). evi ... | 1992 | 1335835 |
| antiviral (rna) activity of selected amaryllidaceae isoquinoline constituents and synthesis of related substances. | a series of 23 amaryllidaceae isoquinoline alkaloids and related synthetic analogues were isolated or synthesized and subsequently evaluated in cell culture against the rna-containing flaviviruses (japanese encephalitis, yellow fever, and dengue viruses), bunyaviruses (punta toro, sandfly fever, and rift valley fever viruses), alphavirus (venezuelan equine encephalomyelitis virus), lentivirus (human immunodeficiency virus-type 1) and the dna-containing vaccinia virus. narciclasine [1], lycoricid ... | 1992 | 1336040 |
| animal immunodeficiency viruses. | feline immunodeficiency virus (fiv) has morphological, physical and biochemical characteristics similar to human immunodeficiency virus (hiv), the cause of aids in man. however, it is antigenically and genetically distinct from hiv; an antigenic relatedness with equine infectious anaemia virus has been demonstrated. fiv has been molecularly cloned and sequenced. diagnostic tests are commercially available and attempts at preparing inactivated, subunit and molecularly engineered vaccines are bein ... | 1992 | 1336243 |
| spatial visualization of progressive states of maturing lentivirus. | progressive states of maturing lentivirus: maedia visna virus (mvv) and human immunodeficiency virus (hiv), respectively, have been visualized by 2-d electron microscopy and by 3-d electron microscopic tomography. a major fraction of mvv and a low percentage of hiv appear as immature particles 4 to 5 days post virus infection. upon budding the gag-precursor material is densely packed inside the external envelope. after virus release the major portion of precursors is assembled within an approxim ... | 1992 | 1336244 |
| equine lentivirus, comparative studies on four serological tests for the diagnosis of equine infectious anaemia. | serological diagnosis of equine infectious anemia is of necessity group-reactive, i.e. based on viral core protein p26, because viral envelope components as well as the host's immune response to them undergo rapid antigenic change. since 1970 the agar gel-immunodiffusion test ("coggins-test") has been the diagnostic method of choice. recently, elisa tests have been introduced for faster and theoretically more sensitive serodiagnosis, while western blots have been used to clarify doubtful results ... | 1992 | 1336247 |
| 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 |
| serological evidence for the presence of bovine lentivirus infection in cattle in australia. | | 1992 | 1337246 |
| 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 |
| evaluation of 9-(2-phosphonylmethoxyethyl) adenine therapy for feline immunodeficiency virus using a quantitative polymerase chain reaction. | to determine the efficacy of 9-(2-phosphonylmethoxyethyl)adenine (pmea) as a prophylactic chemotherapeutic agent for the treatment of lentivirus infections, three groups of specific pathogen free cats were treated with 0, 3, or 6 mg kg-1 twice daily doses of pmea beginning 24 h prior to virus challenge with feline immunodeficiency virus petaluma strain. treatment was continued for 7 weeks post challenge. during this time cats were monitored for drug toxicity, virus specific antibody response, ci ... | 1992 | 1337395 |
| 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 |
| incidence of feline immunodeficiency virus reactive antibodies in free-ranging lions of the kruger national park and the etosha national park in southern africa detected by recombinant fiv p24 antigen. | lion sera from the kruger national park (knp) dating back to 1977 and from the etosha national park (enp), obtained from 1989 to 1991, have been analysed by elisa and western blot analyses using a genetically engineered antigen representing the p24 structural protein of feline immunodeficiency virus (fiv). it was concluded that some 83% of 98 knp lion sera reacted with the p24 antigen, while none of 28 enp lion sera reacted. a few other knp felids (cheetahs and genets) gave samples that did not ... | 1992 | 1338477 |
| caprine arthritis-encephalitis (cae). occurrence of positive sera in goats raised in brazil. | | 1992 | 1339003 |
| 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 |
| lentiviral arthritis and encephalitis in goats in north-west syria. | a survey for antibodies against caprine arthritis and encephalitis (cae) virus was undertaken in north-west syria. out of 72 sera, using agar immuno-diffusion test, 12.5% showed a positive reaction. despite the seropositiveness, no clinical evidence of the infection was found in the tested animals. the findings indicate that the infection is endemic in the area studied. | 1992 | 1339988 |
| neurological aspects of lentiviral infections in animals. | | 1992 | 1344653 |
| ovine lentivirus is macrophagetropic and does not replicate productively in t lymphocytes. | the lentiviruses of sheep, goats, and horses cause chronic multiorgan disease in which macrophages are highly permissive for viral replication. monocytes, which mature into macrophages, are thought to be latently infected with lentivirus, but the extent to which other leukocytes are infected is unknown. dendritic cells have not been studied separately from monocytes and t-cell subsets have not been examined in previous attempts to identify infected cells in peripheral blood mononuclear cells (pb ... | 1992 | 1348546 |
| characteristics of the t cell-mediated immune response to maedi-visna virus. | virus-specific t cell-mediated immunity was investigated in healthy sheep persistently infected with the ruminant lentivirus maedi-visna. visna-specific lymphocyte proliferation was demonstrated in response to both purified virions and recombinant p25, the major core protein of maedi-visna virus. the responding t cell population in this assay was mainly of the cd4+ phenotype, although in some individuals cd8+ t cells were also shown to respond to visna antigen in this system. | 1992 | 1360179 |
| animal cell culture and the aids problem. | | 1990 | 1369270 |
| tests to combat lentiviruses in domestic animals. biotechnology research group. | since the discovery of human immunodeficiency virus (hiv) as the cause of aids the study of other members of the virus group lentivirinal has intensified. a major outcome of this research have been the development of "state of the art" diagnostic tests. while it has long been realised that these viruses were important causes of slowly developing diseases in sheep and horses other lentiviruses have recently been implicated in similar disease situations in goats, cats and cattle. membership of the ... | 1992 | 1369414 |
| use of bacterial trpe fusion vectors to express and characterize the bovine immunodeficiency-like virus core protein. | the gag coding region from bovine immunodeficiency-like virus (biv) was cloned into e. coli and expressed as a bacterial fusion protein. six different clones spanning various regions of the gag open reading frame were generated. the resulting fusion proteins were expressed at high concentrations and readily purified. a panel of bovine immune sera specifically recognized the recombinant gag proteins, as did immune sera from animals infected or immunized with lentiviruses related to biv, such as e ... | 1992 | 1372612 |
| characterisation of visna virus reverse transcriptase: a micro scale reverse transcriptase assay adapted for use with an automated cell harvester. | the reverse transcriptase of the sheep lentivirus visna/maedi virus has been characterised. optima for magnesium ion concentration (5-10 mm), potassium ion concentration (150 mm) and ph (8.25) for this enzyme are very similar to those previously described for the human immunodeficiency viruses. the assay used for this work makes use of a cell harvester to speed up the processing of multiple samples. it is small scale, requiring 15 microliters of sample, is rapid, and is able to detect virus at t ... | 1992 | 1372910 |
| propagation and characterization of novel canine lentivirus isolated from a dog. | we have recently isolated a novel canine lentivirus (canine immunodeficiency virus, [civ]) from a leukemic dog. the virus was isolated from buffy coat cells obtained from the leukemic dog co-cultivated with indicator cells. the virus particles encode a reverse transcriptase with a preference for magnesium, have a density of 1.16 g/ml in sucrose, and induce syncytia in permissive cell lines such as himalayan tahr ovary and canine fetal thymus. civ replicates to high titer and highly purified viru ... | 1992 | 1376381 |
| wild-type equine infectious anemia virus replicates in vivo predominantly in tissue macrophages, not in peripheral blood monocytes. | in situ hybridization of tissues from two horses infected with the wild-type wyoming strain of equine infectious anemia virus (eiav) identified the liver, spleen, lymph nodes, kidney, lung, and adrenal gland as the primary host tissue sites for viral transcription during acute infection. combined immunohistochemistry, with a monoclonal antibody recognizing a cytoplasmic antigen of equine mononuclear phagocytes, and in situ hybridization for viral rna identified most infected cells as mature tiss ... | 1992 | 1382143 |
| worldwide prevalence of lentivirus infection in wild feline species: epidemiologic and phylogenetic aspects. | the natural occurrence of lentiviruses closely related to feline immunodeficiency virus (fiv) in nondomestic felid species is shown here to be worldwide. cross-reactive antibodies to fiv were common in several free-ranging populations of large cats, including east african lions and cheetahs of the serengeti ecosystem and in puma (also called cougar or mountain lion) populations throughout north america. infectious puma lentivirus (plv) was isolated from several florida panthers, a severely endan ... | 1992 | 1382145 |
| subtyping of human immunodeficiency virus isolates with a panel of monoclonal antibodies: identification of conserved and divergent epitopes on p17 and p25 core proteins. | we have investigated the feasibility and significance of subtyping of human immunodeficiency virus (hiv) isolates with monoclonal antibodies (mab) raised against the core proteins of hiv. a panel of 37 mab tested for reactivity with hiv1 oligopeptides was used to analyse the antigenic relatedness among 14 hiv isolates which included 12 isolates of hiv1 from different geographical origins and 2 isolates of hiv2. three out of these 37 mab reacted with conserved epitopes expressed by all 14 hiv iso ... | 1992 | 1382219 |
| a nonradioactive micro-assay for released reverse transcriptase activity of a lentivirus. | a nonradioactive micro-assay procedure for detection of released reverse transcriptase activity from cells infected with equine infectious anemia virus is described. this procedure utilizes biotinylated-dutp in conjunction with a streptavidin-alkaline phosphatase conjugate. detection of alkaline phosphatase is by autoradiography of the chemiluminescence produced during enzymatic dephosphorylation of lumi phos 530. this method, as with reverse transcriptase micro-assays employing 32p-labeled nucl ... | 1992 | 1382469 |
| analysis of antibody response to ovine lentivirus by using viral gene products expressed in a prokaryotic system. | the polymerase chain reaction (pcr) was used to amplify, clone, and express eight dna fragments encoding p25, p16, reverse transcriptase (rt) core, c'-terminal rt, n'- and c'-terminals of external (gp70), and transmembrane (gp40) envelope proteins from visna virus infectious recombinant dna. efforts were focused on characterizing the nature of the humoral immune response of ovine progressive pneumonia (opp) virus infected animals and identifying the conserved and prime-reactive antigenic determi ... | 1992 | 1384477 |
| phenotypic analysis of lymphocyte populations in the lungs and regional lymphoid tissue of sheep naturally infected with maedi visna virus. | we have analysed the phenotype of lymphocytes in lung and regional lymph node of symptomatic and asymptomatic sheep infected with the ovine lentivirus, maedi visna virus (mvv). compared to equivalent tissues from age-matched, non-infected controls, mvv-infected sheep show increased numbers of lymphocytes in the lung, both in the bronchus-associated lymphoid tissue (balt) and in the alveolar septae. both cd8+ and cd4+ t lymphocyte numbers in alveolar septae were increased, particularly in animals ... | 1992 | 1385026 |
| morphogenesis of human immunodeficiency virus type 1. | human immunodeficiency virus (hiv) has been implicated as the etiologic agent of acquired immunodeficiency syndrome and is a member of the sub-family lentivirinae within the family retroviridae. hiv type 1 (hiv-1) contains three major genes, gag, pol and env, which code for (1) core proteins, (2) a protease, reverse transcriptase and integrase, and (3) envelope glycoproteins, respectively. the core proteins p17, p24 and p15 are derived from gag precursor, p55, by endoproteolytic cleavage. the tw ... | 1992 | 1388714 |
| arteriopathy in macaques infected with simian immunodeficiency virus. | an arteriopathy characterized by intimal and medial thickening and fibrosis was seen in 19 of 85 rhesus monkeys infected with simian immunodeficiency virus (siv), a lentivirus with morphologic, genetic, and biologic similarities to hiv-1 and hiv-2. | 1992 | 1405492 |
| mononuclear phagocytes as targets, tissue reservoirs, and immunoregulatory cells in human immunodeficiency virus disease. | we have presented evidence in this review for the following: 1. macrophages are likely the first cell infected by hiv. studies document recovery of hiv into macrophages in the early stages of infection in which virus isolation in t cells is unsuccessful and detectable levels of antibodies against hiv are absent. 2. macrophages are major tissue reservoirs for hiv during all stages of infection. unlike the lytic infection of t cells, many hiv-infected macrophages show little or no virus-induced cy ... | 1992 | 1424782 |
| simian immunodeficiency virus vectors: replication and pseudotyping. | we studied a single round of replication of simian immunodeficiency virus (siv) through the use of a replication defective vector that expresses the hygromycin resistance gene. it was possible to pseudotype siv particles by complementation with the env gene from a murine amphotropic retrovirus. moreover, siv rna was packaged and propagated by core particles of the heterologous lentivirus, hiv-1. these results indicate that coinfection of cells with siv and other retroviruses could lead to infect ... | 1992 | 1433269 |
| [suspicion of visna in a sheep from graubünden canton]. | a lentivirus belonging to the group of retroviridae causes a chronic progressive interstitial pneumopathy (maedi) or a demyelinating encephalo-myelitis (visna) in sheep and goats. pulmonary lesions of maedi as well as sero-positive, clinically healthy animals can be observed in switzerland; visna, which even in countries with endemic infection does not occur frequently, is extremely rare. the head and cervical spine of an ewe with severe nervous troubles suspected of scrapie were submitted for p ... | 1992 | 1439707 |
| animal models for anti-aids therapy. | primate and non-primate species have been used to study the pathobiology of the simian immunodeficiency virus (siv) and of the human immunodeficiency virus type 1 (hiv-1), respectively, and to develop new therapeutic regimes. transgenic mice which express either the entire hiv-1 provirus or subgenomic fragments have been used to analyze viral gene products in vivo and may serve as models for the development of agents targeted to select viral functions. chimeric mice which were created by transpl ... | 1992 | 1444326 |
| conserved structural features in the interaction between retroviral surface and transmembrane glycoproteins? | among the retroviruses, the surface (su) and transmembrane (tm) glycoproteins of lentiviruses are linked exclusively by noncovalent bonds. for some c-type retroviruses, however, a small proportion of the su proteins has been shown to be linked to their tm proteins by a disulfide bond, with the remainder being noncovalently associated. a region near the carboxyl terminus of the hiv-1 su glycoprotein has been implicated in contacting the tm glycoprotein. computer modelling indicates that this regi ... | 1992 | 1457203 |
| use of lentivirus-like particles alone and in combination with live vaccinia-virus-based vaccines. | | 1992 | 1466979 |
| comparison of protection afforded by whole virus iscom versus mdp adjuvanted formalin-inactivated siv vaccines from iv cell-free or cell-associated homologous challenge. | a siv-iscom and a siv-mdp adjuvanted vaccine were tested for their potential to induce protection from intravenous cell-free or cell-associated homologous siv challenge in rhesus monkeys (macaca mulatta). seven monkeys vaccinated four times over a four-month period with either the siv-iscom or the siv-mdp vaccine were challenged intravenously with approximately 10 mid50 cell-free sivmac251 (32h). they all were protected from developing viremia during a three-month observation period. two other g ... | 1992 | 1466991 |
| the simian immunodeficiency virus infected macaque: a model for pediatric aids. | maternal-to-infant transmission of simian immunodeficiency virus (siv) has been demonstrated in the rhesus macaque following experimental infection of pregnant rhesus monkeys, either parenterally or by inoculation of virus into the amniotic fluid. virus infection occurred in 3 of 12 (25%) rhesus infants born to mothers with siv infection induced by parenteral inoculation of virus during gestation. however, these infants did not become seropositive or virus positive until they were 9-15 months ol ... | 1992 | 1480404 |
| differences in neutralization of simian lentivirus (sivmac) in lymphocyte and macrophage cultures. | comparison of neutralization of sivmac251 in primary macrophage cultures with neutralization in lymphocytes (cem174 cells) showed that neutralizing antibodies induced by siv251 in infected rhesus macaques protected both macrophages and t lymphocytes against infection when the virus was preincubated with the antibodies. in macrophages, the neutralizing antibodies also protected against infection when added 1 hour after the virus. addition of antisera to macrophages between 24 and 48 hours after v ... | 1992 | 1503828 |
| synthesis and antiviral evaluation of n-carboxamidine-substituted analogues of 1-beta-d-ribofuranosyl-1,2,4-triazole-3-carboxamidine hydrochloride. | ten, hitherto unreported, analogues of 1-beta-d-ribofuranosyl-1,2,4-triazole-3-carboxamidine hydrochloride (2a, ribamidine) and methyl carboximidate 5 have been synthesized. these include the n-cyano (2b), n-alkyl (2c-e), n-amino acid (2f-h), n,n'-disubstituted (6, 7a,b), and the n-methylated carboxamide (1f) analogues of ribavirin. in addition, a new facile synthesis of carboxamidine 2a was also developed. all compounds were evaluated for biological activity against the following rna viruses: p ... | 1992 | 1507208 |
| serum amyloid a gene transcription in synovial cells during retroviral arthritis. | in situ hybridization was used to demonstrate serum amyloid a (saa) gene expression in arthritic joint tissue from lentivirus-infected sheep and goats. saa gene transcription occurs in isolated individual synovial cells and occasional giant cells but not in uninfected or uninflamed synovial tissue. these findings support the notion (derived from in vitro observations) that at least one member of the saa gene/protein family may function as an autocrine collagenase inducer in inflammatory arthriti ... | 1992 | 1519661 |
| protection of macaques against siv infection by subunit vaccines of siv envelope glycoprotein gp160. | simian immunodeficiency virus (siv) is a primate lentivirus related to human immunodeficiency viruses and is an etiologic agent for acquired immunodeficiency syndrome (aids)-like diseases in macaques. to date, only inactivated whole virus vaccines have been shown to protect macaques against siv infection. protective immunity was elicited by recombinant subunit vaccines. four macaca fascicularis were immunized with recombinant vaccinia virus expressing sivmne gp160 and were boosted with gp160 pro ... | 1992 | 1531159 |
| hiv infection and rheumatic diseases--autoimmune mechanisms in immunodeficient hosts. | the recognition of a newly acquired immunodeficiency syndrome (aids) in 1981 has had dramatic social and economic implications. eventually, an epidemic of the viral infection developed with a potential to spread globally. the extraordinary breadth of aids research lead to the early identification of the causative agent: the human immunodeficiency virus (hiv) is a member of the lentivirus family and is characterized by its ability to remain latent within the genome of the infected host. the prima ... | 1992 | 1535472 |
| hiv-1 replication and potential targets for intervention. | intense research into fundamental processes of human immunodeficiency syndrome type 1 (hiv-1) replication has yielded knowledge that in many aspects equals or exceeds that of the oncogenic retroviruses. the availability of sensitive virus detection methods has allowed a more thorough characterization of the biology of virus persistence and latency in vivo and removed the dependence on in vitro models. as a clearer picture of the pattern of hiv-1 replication in vivo evolves, it becomes apparent t ... | 1992 | 1540400 |
| quantitation of a lentivirus in its natural host: simian immunodeficiency virus in african green monkeys. | we have examined the viral load in the peripheral blood of simian immunodeficiency virus (siv)-infected african green monkeys with a view to the unexplained apathogenicity of african green monkey siv (sivagm) in its natural host. by using polymerase chain reaction, viral dna was detected in fresh peripheral blood mononuclear cells (pbmc) of each of nine seropositive animals. the virus dna load was variable among the monkeys tested, ranging from 5 to 50 (mean = 15) copies per 10(5) pbmc, which is ... | 1992 | 1548755 |
| ovine lentivirus: a real or imagined threat? | | 1992 | 1559865 |
| the immunology of virus infections. | in order to describe the complex virus-host relationship the authors review the viral mechanisms of infection and viral replication as well as the basic pattern of the immune responses. the delicate balance of the infection-immunity equation is complicated by the instability of both entities. the better understanding of these factors provides a rationale for the therapeutic counteraction of virus infections, reducing the likelihood of viral exposure becoming clinical viral infection. | 1992 | 1568354 |
| derivation of neurotropic simian immunodeficiency virus from exclusively lymphocytetropic parental virus: pathogenesis of infection in macaques. | neurological disease resulting from lentivirus (including human immunodeficiency virus) infections is usually caused by a strain of virus that replicates productively in microglia in vivo and in macrophage cultures in vitro. we undertook this study using the model of simian immunodeficiency virus in macaques (sivmac) to test the hypothesis that macrophage tropism is a prerequisite for neurotropism of the virus. using molecularly cloned sivmac239, a virus which is lymphocyte- but not macrophagetr ... | 1992 | 1583723 |
| [lentivirus expression at the moment of lambing modifies the leukocyte number in the milk of multiparous ewes]. | lambing in small ruminants is a time of high lentivirus expression; infected mononuclear phagocytes are frequent in colostrum and milk. we have studied mammary secretions in 5 multiparous ewes and shown that infected macrophages in milk are accompanied by an augmentation of leucocyte number. the lymphocyte cd8 subpopulation increased in size simultaneously with the onset of infected cell excretion. the udder infection by coagulase negative staphylococci did not modulate milk lymphocyte content. ... | 1992 | 1610081 |
| isolation and characterization of a new chimpanzee lentivirus (simian immunodeficiency virus isolate cpz-ant) from a wild-captured chimpanzee. | to assess the prevalence of infection with simian immunodeficiency virus (siv) isolate cpz, a lentivirus closely related to hiv-1, in chimpanzees, and to obtain new sivcpz isolates. | 1992 | 1616649 |
| prospects for reducing virus-associated human cancers by antiviral vaccines. | the last 25 years have seen a major effort to identify human viruses that either cause cancer in humans directly or can be considered significant cofactors or promoters of cancer. the prevailing view is that tumor-associated viruses are necessary but not sufficient for tumor causation. a long latent period between the initial infection and the appearance of the neoplasm is the norm. generally, the virus implicated as causative is integrated into cellular dna. various virus types have been identi ... | 1992 | 1616793 |
| 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 |
| [basic understanding of retroviruses]. | retroviruses contain a reverse transcriptase in the virion that converts viral genomic rna to proviral dna. retroviruses are divided into three groups; oncovirus, lentivirus, and spumavirus. the oncovirus group contains htlv-1, which causes adult t-cell leukemia, encephalomyeloneuropathy, arthritis, and alveolo-bronchopathy. the lentivirus groups contains hiv, which causes acquired immunodeficiency syndrome and dementia. the genomic structures and functions of htlv-1 and hiv have been demonstrat ... | 1992 | 1630036 |