Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
mode of action of sdz nim 811, a nonimmunosuppressive cyclosporin a analog with activity against human immunodeficiency virus (hiv) type 1: interference with hiv protein-cyclophilin a interactions.cyclosporins, in particular the nonimmunosuppressive derivative sdz nim 811, exhibit potent anti-human immunodeficiency virus type 1 (hiv-1) activity in vitro. sdz nim 811 interferes at two stages of the viral replication cycle: (i) translocation of the preintegration complex to the nucleus and (ii) production of infectious virus particles. immunosuppressive activity is not correlated with anti-hiv-1 activity of cyclosporins. however, binding to cyclophilin a, the major cellular receptor protein ...19957884893
chimeric macaque/human fab molecules neutralize simian immunodeficiency virus.a collection of simian immunodeficiency virus (siv) neutralizing recombinant fab fragments was generated using the combinatorial antibody library approach. functional antibody fragments efficiently expressed in escherichia coli were identified only in the form of chimeric macaque heavy chain gamma 1 and human light chain kappa. the gamma 1 and kappa chains were derived from a clinically healthy long-term surviving sivsm-infected cynomolgus macaque and from an asymptomatic hiv-2 seropositive indi ...19957886953
insertion of a short human immunodeficiency virus (hiv)-2 gp36 sequence into an hiv-1 p24 recombinant protein results in a polypeptide with potent and tcrbv-restricted t cell triggering activity.in the present work we investigate whether artificial alterations of the structure of an inactive retrovirus-encoded protein could transform it in a superantigen. as a model system we used a recombinant human immunodeficiency virus (hiv)-1 p24 protein and two of its variants in which a short peptide corresponding to sequences of gp41 of hiv-1 (hiv-1 p24*) or gp36 of hiv-2 (hiv-1-2 p24*) has been inserted nearby the carboxy-terminal end of hiv-1 p24. as expected both hiv-1 p24 and hiv-1 p24* were ...19957843234
cosalane analogues with enhanced potencies as inhibitors of hiv-1 protease and integrase.several new analogues of the novel anti-hiv agent cosalane have been synthesized and evaluated as inhibitors of hiv-1 integrase and protease, hiv-1 replication, hiv-1 and hiv-2 cytopathicity, hiv-1- and hiv-2-mediated syncytium formation, and cytopathicity of a variety of human pathogenic viruses. the congeners displayed enhanced potencies relative to cosalane itself as inhibitors of hiv-1 integrase and protease. the two most potent analogues against hiv-1 integrase displayed ic50 values of 2.2 ...19957853337
reactivation of human immunodeficiency virus type 2 in macaques after simian immunodeficiency virus sivmac superinfection.by superinfection of human immunodeficiency virus type 2 (hiv-2) strain hiv-2ben-infected macaques with simian immunodeficiency virus (siv) strain sivmac, we investigated the mutual influences of an apathogenic and a pathogenic virus in vivo. four rhesus and two cynomolgus monkeys were infected with hiv-2ben in 1988 and 1989, respectively. virus could be reisolated from five of six animals 6 weeks after infection. the monkeys remained healthy over the next 2 to 3 years. pcr for viral rna became ...19957853490
lentivirus tat proteins specifically associate with a cellular protein kinase, tak, that hyperphosphorylates the carboxyl-terminal domain of the large subunit of rna polymerase ii: candidate for a tat cofactor.efficient replication of human immunodeficiency virus types 1 and 2 (hiv-1 and hiv-2) requires the virus transactivator proteins known as tat. in order to understand the molecular mechanisms involved in tat transactivation, it is essential to identify the cellular target(s) of the tat activation domain. using an in vitro kinase assay, we previously identified a cellular protein kinase activity, tat-associated kinase (tak), that specifically binds to the activation domains of tat proteins. here i ...19957853496
virion incorporation of envelope glycoproteins with long but not short cytoplasmic tails is blocked by specific, single amino acid substitutions in the human immunodeficiency virus type 1 matrix.incorporation of envelope glycoproteins into a budding retrovirus is an essential step in the formation of an infectious virus particle. by using site-directed mutagenesis, we identified specific amino acid residues in the matrix domain of the human immunodeficiency virus type 1 (hiv-1) gag protein that are critical to the incorporation of hiv-1 envelope glycoproteins into virus particles. pseudotyping analyses were used to demonstrate that two heterologous envelope glycoproteins with short cyto ...19957853546
time course of detection of viral and serologic markers preceding human immunodeficiency virus type 1 seroconversion: implications for screening of blood and tissue donors.almost all human immunodeficiency virus (hiv) transmission via blood or tissues that has occurred since anti-hiv screening was implemented in 1985 is traceable to blood given after infection but before antibody seroconversion, a time that is referred to as the window period. in this study, the performance of newer assays designed to detect viral and serologic markers soon after infection is assessed, and the reduction in the window period achieved by these assays is estimated.19957825218
synthesis and structure-activity relationships of phenylenebis(methylene)-linked bis-tetraazamacrocycles that inhibit hiv replication. effects of macrocyclic ring size and substituents on the aromatic linker.we have previously described the potent and selective inhibition of several strains of human immunodeficiency virus type 1 (hiv-1) and type 2 (hiv-2) by jm2763, an n-propyl-linked dimer of the 1,4,8,11-tetraazamacrocyclic (cyclam) ring system. upon further investigation, we have also found that incorporating an aromatic rather than aliphatic linker leads to analogs with higher antiviral potency. the prototype, jm3100 (19a, isolated as the octahydrochloride salt), which contains a p-phenylenebis( ...19957830280
activities and substrate specificity of the evolutionarily conserved central domain of retroviral integrase.the retroviral integrase (in) is a virus-encoded enzyme that is essential for insertion of viral dna into the host chromosome. in order to map and define the properties of a minimal functional domain for this unique viral enzyme, a series of n- and c-terminal deletions of both rous sarcoma virus (rsv) and human immunodeficiency virus (hiv) ins were constructed. the rsv in deletion mutants were first tested for their ability to remove two nucleotides from the end of a substrate representing the t ...19957831800
full expression of transfected nonproducer interfering hiv-1 proviral dna abrogates susceptibility of human he-la cd4+ cells to hiv.an hut-78 cell clone (f12) harboring a nonproducer human immunodeficiency virus-1 (hiv) variant, and showing a complete resistance to hiv-1 or hiv-2 superinfection, was previously characterized. we demonstrated that the replication of the superinfecting hivs is blocked at the retrotranscription step, despite the cd4 down-regulation, since hivs are able to cross the hut-78/f12 cell membrane. in order to establish if the expression of the hiv-1 variant (f12/hiv) could be per se sufficient to induc ...19957831838
enhancement of infectivity of a non-syncytium inducing hiv-1 by scd4 and by human antibodies that neutralize syncytium inducing hiv-1.enhancement of virus infectivity after scd4 treatment has been documented for sivagm and hiv-2. it has been suggested that a similar phenomenon may play a role in hiv-1 infection. in the present study we have analysed biological activities of virus neutralizing polyclonal and monoclonal human antibodies and of scd4, towards hiv-1 chimeras with envelope proteins derived from one donor, which display different biological phenotypes. the antibodies, which recognize the v3 and/or the cd4 binding dom ...19957824885
evidence of serological cross-reactivities with human immunodeficiency virus types 1 and 2 and human t-lymphotropic virus types i and ii in sera of pregnant women in ibadan, nigeria.our previous studies have indicated that the human immunodeficiency virus (hiv) and human t-lymphotropic virus (htlv) groups of retroviruses are endemic among various populations in nigeria. these viruses are antigenically distinct and antibodies to hiv and htlv do not cross-react, so we studied the prevalence of hiv-1, hiv-2, htlv-i and htlv-ii antibodies in sera of pregnant women attending an antenatal clinic in ibadan, nigeria.19957797344
a conserved domain and membrane targeting of nef from hiv and siv are required for association with a cellular serine kinase activity.among the primate lentiviruses (human immunodeficiency virus (hiv) -1, hiv-2, and simian immunodeficiency virus (siv), the nef gene is highly conserved and encodes a myristylated protein of approximately 27 kda (hiv-1) or approximately 34 kda (hiv-2, siv). previously, we found nef expressed either as a cd8-nef fusion protein or as a native protein in virally infected t cell lines associates with a cellular serine kinase. this kinase activity phosphorylated two proteins of 62 and 72 kda that coim ...19957797518
regions required for cd4 binding in the external glycoprotein gp120 of simian immunodeficiency virus.the external domain of the envelope glycoprotein, gp120, of simian immunodeficiency virus (siv) has been expressed as a mature secreted product using recombinant baculoviruses and the expressed protein, which has an observed molecular mass of 110 kda, was purified by monoclonal antibody (mab) affinity chromatography. n-terminal sequence analysis showed a signal sequence cleavage identity similar to that of the gp120s of both human immunodeficiency virus type 1 (hiv-1) and hiv type 2. the express ...19957815501
[virulence of human immunodeficiency virus].virulence is relative capacity of a virus, compared to other closely related viruses, to produce disease in a host. viral strains considered as virulent have been described in hiv-1 infected patients. they are characterized in vitro by enhanced cellular host range, rapid kinetic of replication and increased capacity of syncytium induction. some genetic modification of the v3 loop in the envelope gene have been associated with the emergence of these strains. but at aids diagnosis, and even at the ...19957754307
comparison of 24 different adjuvants for inactivated hiv-2 split whole virus as antigen in mice. induction of titres of binding antibodies and toxicity of the formulations.the objective of this study was the comparison of the quantity and quality of the humoral immune response against inactivated whole human immunodeficiency virus type 2. twenty-four different adjuvants were tested. the toxicity of these preparations was determined. due to the large number of experiments, the animal model used was the nmri mouse. sera were assayed for the presence of antibodies by elisa and western blot. the toxicity of the adjuvants was determined by observing lethal side-effects ...19957762277
lack of relationship between human immunodeficiency virus infection and systemic lupus erythematosus.the objective of this work was to determine whether hiv-1 and hiv-2 could be involved in the pathogenesis of systemic lupus erythematosus (sle). seventy-five consecutive caucasian patients with sle presenting at one institution over a 2-year period were studied. serum samples were surveyed for anti-hiv-1 antibodies by a commercial elisa coated with hiv-1-p24. for confirmation, conventional immunoblots were performed with the following antigens: hiv-1-gp41, p31, p24 and p17 (recombinant) and hiv- ...19957767339
detection of hiv-1 rna in plasma and serum samples using the nasba amplification system compared to rna-pcr.the presence of hiv-1 rna in the plasma and serum of european and african patients was monitored using rna-polymerase chain reaction (rna-pcr) and the new isothermal nasba nucleic acid amplification system encompassing a gel-based detection assay (elga). identical rna extraction procedures, provided by the nasba amplification system, were used for both methods. the detection limit for hiv-1 rna, measured on a 10-fold dilution series of spiked hiviiib in negative plasma, was about 0.05 ccid50 per ...19957769025
epidemiological characteristics of human immunodeficiency virus type-2 infection in africa.there are things yet to be clarified about african hiv-2 infection, compared to hiv-1 infection. however, the epidemiological characteristics have gradually been elucidated through various studies. hiv-2 infection is believed to have existed in the 1960s in africa and is presently epidemic in west africa. the hiv-2 seropositive rate for the general population is higher in urban regions than in rural areas. the peak age of persons infected with the hiv-2 tends to be higher than that of persons in ...19957779934
humoral and cellular immune responses in rhesus macaques infected with human immunodeficiency virus type 2.eighteen rhesus macaques were inoculated with either an infectious molecularly cloned human immunodeficiency virus type 2 (hiv-2)sbl/isy, or with one of eight mutants defective in one or more accessory genes. the immune responses generated by the macaques were monitored for up to 2 years postinfection. all the macaques except those that received mutants lacking the vpr or vif genes demonstrated low to moderate antibody titers. macaques inoculated with vpx- mutants exhibited a persistent serologi ...19957786583
evaluation of hiv type 1 western blot-indeterminate blood donors for the presence of human or bovine retroviruses.from 1985 through 1990, 1100 of 500,000 human blood donations in syracuse, new york were repeatedly reactive by elisa for antibodies to the human immunodeficiency virus type 1 (hiv-1). nine hundred of the elisa-reactive samples were confirmed as negative by western blot (wb), 40 were confirmed as positive, and the remaining 160 sera were indeterminate, reacting mainly with hiv-1 gag gene products. twenty donors with the most reactive indeterminate wb were selected for follow-up studies. four of ...19957786586
the epidemiology of hiv in india.india is the first country outside africa where an hiv-2 epidemic is running in parallel to an hiv-1 epidemic, resulting in a significant proportion of double infections. hiv is spreading rapidly, mainly by heterosexual contact, but also among intravenous drug users. genetic analyses of the hiv variants circulating in india point towards hiv-1 and hiv-2 having been introduced into the country recently.19957719634
recombination in aids viruses.recombination contributes to the generation of genetic diversity in human immunodeficiency viruses (hiv) but can only occur between viruses replicating within the same cell. since individuals have not been found to be simultaneously coinfected with multiple divergent strains of hiv-1 or hiv-2, recombination events have been thought to be restricted to the rather closely related members of the quasispecies that evolves during the course of hiv infection. here we describe examples of both hiv-1 an ...19957723052
antiviral properties of aminodiol inhibitors against human immunodeficiency virus and protease.a series of aminodiol inhibitors of human immunodeficiency virus type 1 (hiv-1) protease were identified by using an in vitro peptide cleavage assay. bms 182,193, bms 186,318, and bms 187,071 protected cells against hiv-1, hiv-2, and simian immunodeficiency virus infections, with 50% effective doses ranging from 0.05 to 0.33 microm, while having no inhibitory effect on cells infected with unrelated viruses. these compounds were also effective in inhibiting p24 production in peripheral blood mono ...19957726501
evaluation of an agglutination hiv-1 + 2 antibody assay.studies have shown that an hiv (hiv-pa) agglutination assay (serodia) for the detection of antibody to human immunodeficiency virus (hiv) can be as sensitive and as specific as enzyme-linked immunosorbent assay (elisa). however, since this hiv assay was designed to detect antibody to the hiv-1 virus, a substantial number of hiv-2 positive sera are missed by this assay. since the hiv-2 has now been found throughout the world this test is becoming less suitable. the new hiv-1 + 2 assay version (hi ...19957730430
mutagenesis of the putative alpha-helical domain of the vpr protein of human immunodeficiency virus type 1: effect on stability and virion incorporation.vpr is one of the auxiliary genes of human immunodeficiency virus type 1 (hiv-1) and is conserved in the related hiv-2/simian immunodeficiency virus lentiviruses. the unique feature of vpr is that it is the only nonstructural protein incorporated into the virus particle. secondary structural analysis predicted an amphipathic alpha-helical domain in the amino terminus of vpr (residues 17-34) which contains five acidic and four leucine residues. to evaluate the role of specific residues of the hel ...19957731985
oligomerization of the hiv type 2 nef protein: mutational analysis of the heptad leucine repeat motif and cysteine residues.the human immunodeficiency virus type 2 (hiv-2) nef protein expressed in escherichia coli forms highly stable homooligomeric complexes in vitro. similarly, the native protein synthesized in the persistently infected h9 t cell line also forms stable homooligomers in vivo. to determine whether homooligomer formation is mediated by the leucine zipper-type sequence located in the middle region of the protein, site-directed mutagenesis was used to introduce double and triple point mutations at heptad ...19957734198
human immunodeficiency virus type 2 (hiv-2): packaging signal and associated negative regulatory element.human immunodeficiency virus type 2 (hiv-2)-based retroviral vectors will have several desirable features as vehicles for gene therapy. these include target cell specificity, regulated expression, and attenuated cytopathicity. such vectors require efficient packaging of rna into retroviral particles which depends on a cis-acting sequence element called packaging signal or psi site. for most retroviruses, the principal part of this element is located between the major splice donor site and the ga ...19957734518
serological, virological, and polymerase chain reaction studies of hiv type 1 and hiv type 2 infections in ghanaian patients with aids and aids-related complex.we have used a particle agglutination (pa) test, western blot (wb) test, polymerase chain reaction (pcr) test, and virus isolation to define the human immunodeficiency virus (hiv) status of 17 acquired immunodeficiency syndrome (aids), 6 aids-related complex (arc), and 2 asymptomatic ghanaians. hiv-1 antibodies were more frequently detected. the pcr detected 66.7% hiv-1, 11.1% hiv-2, and 5.6% of both hiv-1 and hiv-2 proviral dna in peripheral blood mononuclear cell (pbmcs) and pbmc-molt 4 cocult ...19957742046
crystal structures of hiv-2 protease in complex with inhibitors containing the hydroxyethylamine dipeptide isostere.the hiv protease is essential for the life cycle of the virus and is an important target for the development of therapeutic treatments against aids. the structures of hiv protease in complex with different inhibitors have helped in understanding the interactions between inhibitors and the protease and in the design and optimization of hiv protease inhibitors.19957743130
targeting foreign proteins to human immunodeficiency virus particles via fusion with vpr and vpx.the human immunodeficiency virus type 1 (hiv-1) and hiv-2 vpr and vpx proteins are packaged into virions through virus type-specific interactions with the gag polyprotein precursor. to examine whether hiv-1 vpr (vpr1) and hiv-2 vpx (vpx2) could be used to target foreign proteins to the hiv particle, their open reading frames were fused in frame with genes encoding the bacterial staphylococcal nuclease (sn), an enzymatically inactive mutant of sn (sn*), and chloramphenicol acetyltransferase (cat) ...19957745685
reduced glycosylation of human cell lines increases susceptibility to cd4-independent infection by human immunodeficiency virus type 2 (lav-2/b).the human immunodeficiency virus type 2 (hiv-2) strain lav-2/b is able to infect a variety of human cell lines via a cd4-independent pathway. we have used the glycosylation inhibitors tunicamycin, swainsonine, and deoxymannojirimycin to further characterize this putative alternative receptor for hiv-2 (lav-2/b). these antibiotics resulted in an increase (5- to 30-fold) in the susceptibility of a variety of cd4- human cell lines to infection by lav-2/b (rd, hela, ht29, rsb, heb7a, hos, and daudi) ...19957745686
inducible and conditional inhibition of human immunodeficiency virus proviral expression by vesicular stomatitis virus matrix protein.besides its role in viral assembly, the vesicular stomatitis virus (vsv) matrix (m) protein causes cytopathic effects such as cell rounding (d. blondel, g. g. harmison, and m. schubert, j. virol. 64:1716-1725, 1990). dna cotransfection assays demonstrated that vsv m protein was able to inhibit the transcription of a reporter gene (b. l. black and d. s. lyles, j. virol. 66:4058-4064, 1992). we have confirmed these observations by using cotransfections with an infectious clone of human immunodefic ...19957745700
comparative analyses of human immunodeficiency virus type 1 (hiv-1) and hiv-2 vif mutants.virion infectivity factor (vif), a gene found in all lentiviruses, plays an essential role in virus replication in certain target cells. we examined the replication competence of the human immunodeficiency virus type 2 (hiv-2) vif mutant in different t-cell lines and primary cells in comparison with that of the hiv-1 vif mutant. both mutant viruses were unable to replicate in peripheral blood-derived mononuclear cells but replicated with wild-type efficiency in certain t-cell lines, such as supt ...19957745702
cytotoxicity of 3'-azido-3'-deoxythymidine correlates with 3'-azidothymidine-5'-monophosphate (aztmp) levels, whereas anti-human immunodeficiency virus (hiv) activity correlates with 3'-azidothymidine-5'-triphosphate (azttp) levels in cultured cem t-lymphoblastoid cells.activation of the anti-human immunodeficiency virus (hiv) compound 3'-azido-3'-deoxythymidine (azt) is dependent on its 5'-phosphorylation by cellular nucleoside and nucleotide kinases. azidothymidine 5'-triphosphate (azttp) is considered to be the metabolite responsible for both the anti-hiv effect of azt, via inhibition of reverse transcriptase, and cytoxicity by interference with cellular dna polymerases. during the characterization of azt metabolism in cultured human t-lymphoblastoid cem cel ...19957702641
abt-538 is a potent inhibitor of human immunodeficiency virus protease and has high oral bioavailability in humans.examination of the structural basis for antiviral activity, oral pharmacokinetics, and hepatic metabolism among a series of symmetry-based inhibitors of the human immunodeficiency virus (hiv) protease led to the discovery of abt-538, a promising experimental drug for the therapeutic intervention in acquired immunodeficiency syndrome (aids). abt-538 exhibited potent in vitro activity against laboratory and clinical strains of hiv-1 [50% effective concentration (ec50) = 0.022-0.13 microm] and hiv- ...19957708670
hiv-2 strikes injecting drug users (idus) in india.manipur, a north-eastern state of india bordering myanmar, observed introduction of hiv-1 among fairly large number of idus in october 1989, followed by rapid spread within the next 6 months. hiv-2 in injectors was not present until recently, though it was detected from other parts of india in 1991. this communication reports for the first time presence of hiv-2 among young injectors of manipur. all the hiv-2 infected idus were also found to be infected with hiv-1. hiv-2 has affected a large num ...19958522832
identification of a hexapeptide inhibitor of the human immunodeficiency virus integrase protein by using a combinatorial chemical library.integration of human immunodeficiency virus (hiv) dna into the human genome requires the virus-encoded integrase (in) protein, and therefore the in protein is a suitable target for antiviral strategies. to find a potent hiv in inhibitor, we screened a "synthetic peptide combinatorial library." we identified a hexapeptide with the sequence hckfww that inhibits in-mediated 3'-processing and integration with an ic50 of 2 microm. the peptide is active on in proteins from other retroviruses such as h ...19958524782
identification of rantes, mip-1 alpha, and mip-1 beta as the major hiv-suppressive factors produced by cd8+ t cells.evidence suggests that cd8+ t lymphocytes are involved in the control of human immunodeficiency virus (hiv) infection in vivo, either by cytolytic mechanisms or by the release of hiv-suppressive factors (hiv-sf). the chemokines rantes, mip-1 alpha, and mip-1 beta were identified as the major hiv-sf produced by cd8+ t cells. two active proteins purified from the culture supernatant of an immortalized cd8+ t cell clone revealed sequence identity with human rantes and mip-1 alpha. rantes, mip-1 alp ...19958525373
antiviral, metabolic, and pharmacokinetic properties of the isomeric dideoxynucleoside 4(s)-(6-amino-9h-purin-9-yl)tetrahydro-2(s)-furanmethanol.4(s)-(6-amino-9h-purin-9-yl)tetrahydro-2(s)-furanmethanol (isodda) is the most antivirally active member of a novel class of optically active isomeric dideoxynucleosides in which the base has been transposed from the natural 1' position to the 2' position and the absolute configuration is (s,s). isodda was active against human immunodeficiency virus type 1 (hiv-1) (strain iiib), hiv-2 (strain zy), and hiv-1 clinical isolates. combinations of the compound with zidovudine (3'-azido-3'-deoxythymidi ...19958540705
characteristics and clinical significance of a stabilization assay to detect specific antibodies to reverse transcriptase of human immunodeficiency virus.antibodies against reverse transcriptase (rt) of human immunodeficiency virus type 1 (hiv-1) have been detected in seropositive subjects by immunoprecipitation, western immunoblotting, and neutralization assay. recently, we noticed that the antibodies against rt stabilized rt upon heat inactivation, and we have developed a stabilization assay of rt antibody. briefly, the rt of hiv-1 is completely inactivated by incubation at 56 degrees c for 20 min, but this inactivation is inhibited in the pres ...19958548538
mother-to-child transmission of human immunodeficiency virus type 1 and type 2 and dual infection: a cohort study in banfora, burkina faso.a prospective cohort study on the mother-to-child transmission of human immunodeficiency virus type 1 (hiv1), type 2 (hiv2) and dual positivity (hiv1 + hiv2) was carried out in banfora, west burkina faso. the study samples consist of 117 newborns of hiv-seropositive women matched to 234 newborns of hiv-seronegative women. among cases, 91 were born of hiv1-seropositive mothers, 15 were born of hiv2-seropositive mothers and 11 were born of hiv1 and hiv2 dual-seropositive mothers and were included ...19958584359
potent inhibition of human immunodeficiency virus by mdl 101028, a novel sulphonic acid polymer.mdl 101028, a novel biphenyl disulphonic acid urea co-polymer was designed and synthesised as a heparin mimetic. this low molecular weight polymer showed potent inhibition of human immunodeficiency virus type 1 (hiv-1) replication in a number of host-cell/virus systems, including primary clinical isolates of the virus cultured in human peripheral blood mononuclear cells (pbmcs). when compared with the heterogeneous polysulphated molecules, heparin and dextran sulphate, this chemically defined co ...19958585769
simple enzyme immunoassay for titration of antibodies to the cd4-binding site of human immunodeficiency virus type 1 gp120.we report the development of an immunoassay for the titration of antibody to the cd4-binding site (cd4bs) of the human immunodeficiency virus type 1 (hiv-1) surface glycoprotein gp120. this assay is a competitive enzyme-linked immunosorbent assay in which serum antibodies compete with labeled f105, a human monoclonal antibody whose corresponding epitope overlaps the conformation-dependent cd4bs, for binding to purified recombinant gp120 coated on a solid phase. ninety-nine percent (109 of 110) o ...19958586727
evaluation of a dipstick method for the detection of human immunodeficiency virus infection.serology has been a fundamental tool to prevent post-transfusional infection with human immunodeficiency virus (hiv) and for epidemiological surveys, the first step to attempt control of the pandemia. enzyme immunoassay is in widespread use. nevertheless, simpler methods are needed in many countries, where laboratory facilities and trained personnel are limited, and hiv prevalence is high. the evaluation of a simple and noninstrumented hiv antibody test is presented here. the test employs synthe ...19958587001
[synthesis of an ethylamide of the cyclic undecapeptide sequence 593-603 of transmembrane glycoprotein gp41 of the human immunodeficiency virus type 2].ethylamide of cyclic disulfide of peptide hiv-2 antigen corresponding to 593-603 sequence of gp41 protein was synthesized by conventional methods of peptide chemistry in solution. the absence of racemization during fragment condensation was shown. different methods of disulfide bond formation were compared.19958588812
human immunodeficiency virus infection and human african trypanosomiasis: a case-control study in côte d'ivoire.to assess the association between human immunodeficiency virus (hiv) infection and human african trypanosomiasis (hat) in côte d'ivoire, west africa, a cross-sectional case-control study was conducted on 301 hat patients recruited in the main foci of the country. for each hat patient, 3 controls, matched for sex, age and residence, were selected. data relating to socio-demographic factors and potential risk factors for trypanosoma brucei gambiense and hiv infections were obtained, and serum samp ...19958594681
sc-52151, a novel inhibitor of the human immunodeficiency virus protease.sc-52151 is a potent, selective, tight-binding human immunodeficiency virus (hiv) protease inhibitor containing the novel (r)-(hydroxyethyl) urea isostere. the mean 50% effective concentration for lymphotropic, monocytotropic strains and field isolates of hiv type 1 (hiv-1), hiv-2, and simian immunodeficiency virus is 26 ng/ml (43 nm). the combination of sc-52151 and nucleoside reverse transcriptase inhibitors synergistically inhibited hiv-1 replication without additive toxicity. an extended pos ...19958619573
potent and specific inhibition of human immunodeficiency virus type 1 replication by 4-(2,6-dichlorophenyl)-1,2,5-thiadiazol-3-y1 n,n-dialkylcarbamate derivatives.4-(2,6-dichlorophenyl)-1,2,5-thiadiazol-3-yl n,n-dialkylcarbamate (tda) derivatives were found to be highly potent and specific inhibitors of human immunodeficiency virus type 1 (hiv-1) replication in a variety of cell cultures. the most potent congener of tda derivatives, rd4-2024, inhibited hiv-1 replication by 50% at concentrations of 12.5 and 4.8 nm in mt-4 cells and peripheral blood mononuclear cells, respectively. these concentrations were more than 2,000- and 30,000-fold lower than its 50 ...19958619592
[morphological analysis of a cell system, infected with different strains of the human immunodeficiency virus].cell systems infected with 63 strains of types 1 and 2 hiv virus (hiv-1 and hiv-2) were examined under electron microscope. hiv virions were most frequently detected near the cell membrane or budding from it. in the cytoplasm hiv occurred only in vacuole-like formations. accumulations of mature virions were seen in the cell-to-cell space. mature particles of hiv-1 and hiv-2 differed by their morphology from oncoviral c particles and were similar rater to the visna/medi type lentiviruses. morphol ...19958659180
phylogeny and natural history of the primate lentiviruses, siv and hiv.studies of primate lentivirus phylogeny over the past decade have established a minimum of five related, but genetically distinct, groups of simian immunodeficiency virus (siv), each originating from a different african primate species. the hypothesis that hiv-2 (and sivmac) arose by cross-species transmission from sooty mangabeys (cercocebus atys has been strengthened by a more detailed characterization of the sivsm/sivmac/hiv-2 group of viruses. siv from all four subspecies of african green mo ...19958745080
tyrosine phosphorylation as a possible regulatory mechanism in the expression of human immunodeficiency virus genes.phosphorylation of proteins on serine, threonine and tyrosine is one of the significant regulatory mechanisms in gene expression and post-translational modifications in both eukaryotes and prokaryotes. protein tyrosine phosphorylation in particular is implicated in cell proliferation, differentiation and certain pathological modifications including transformation. the overall protein tyrosine phosphorylation is modulated by protein tyrosine kinases (ptk) and protein tyrosine phosphatases (ptp). ...19958748091
isolation and characterization of the first simian immunodeficiency virus from a feral sooty mangabey (cercocebus atys) in west africa.the lineage of hiv-2-like viruses was studied in feral sooty mangabeys (sms) by serological and genetic methods. four feral sooty mangabeys were positive for simian immunodeficiency virus (siv) antibodies and a new isolate, sivsmsl92a, was obtained. genetic analysis of gag genes showed that sivsmsl92a was highly diverse and a distinct sequence subtype within the siv sm/hiv-2 family. the results showed that sivsm is the most diverse group of sivs found thus far in a single monkey species.19958751049
targeting of chrolamphenicol acetyltransferase to human immunodeficiency virus particles via vpr and vpx.vpr and vpx are the auxiliary proteins of human immunodeficiency viruses (hivs) selectively incorporated into mature viral particles. we showed that the bacterial chloramphenicol acetyltransferase (cat) fused to the n-terminus of hiv-1 vpr, hiv-2 vpr, or hiv-2 vpx was incorporated into mature virions in a type-selective manner. by using chimeric proteins between hiv-1 vpr and hiv-2 vpx, we found that the n-terminal side of these proteins was mainly important for type-selective virion incorporati ...19958789063
poly a-linked non-isotopic microtiter plate reverse transcriptase assay for sensitive detection of clinical human immunodeficiency virus isolates.a colorimetric reverse transcriptase assay (crt assay) was developed for quantitative detection of hiv-1. in this format, reverse transcriptase incorporates biotin-labeled dutp onto oligo-dt primers hybridized to poly a templates. the templates are covalently bound to the surface of microtiter wells. the amount of incorporated biotin-labeled dutp is measured by binding horseradish peroxidase conjugated streptavidin, washing away unbound peroxidase, adding colorimetric substrate and then reading ...19958609200
distinct rate and patterns of human cd4+ t-cell depletion in hu-pbl-scid mice infected with different isolates of the human immunodeficiency virus.the most fundamental question about infection with the human immunodeficiency virus is the mechanism by which infection leads to depletion of cd4+ t lymphocytes, a critical cell type for the regulation of both cellular and humoral immunity. we have studied this issue using a unique small-animal model that is highly susceptible to infection with human immunodeficiency virus. severe combined immune deficient mice are transplanted with human peripheral blood leukocytes to create hu-pbl-scid mice, w ...19958613486
inhibition of hiv-1 expression by hiv-2.hiv-1 and hiv-2 are co-endemic in certain geographic areas. hiv-2 is more weakly pathogenic than hiv-1, and progression to aids occurs less frequently and over a longer period of time. recent epidemiologic studies suggest that individuals infected with hiv-2 have a lower risk of hiv-1 infection. both immune mechanisms and various modes of viral interference have been proposed to account for these results. our findings, described in this paper, suggest that hiv-2 inhibits hiv-1 replication. to st ...19958825754
retrovirus and filovirus "immunosuppressive motif" and the evolution of virus pathogenicity in hiv-1, hiv-2, and ebola viruses.the "immunosuppressive motif" was found to be present in the glycoproteins of retroviruses and filoviruses. this sequence is also conserved in the pathogenic lentiviruses, hiv-1 and siv, and is absent from hiv-2 gp41 and from an apathogenic simian retrovirus. the present analysis deals with the possible involvement of the "immunosuppresessive motif" in the pathogenicity of retroviruses and filoviruses, and the reasons for the conservation of this motif. the ancestral gene from which the "immunos ...19958828145
t-helper reactivity to simian immunodeficiency virus gag synthetic peptides in human immunodeficiency virus type 2 infected individuals.west african populations are infected with divergent strains of human immunodeficiency virus type 2 (hiv2), some of which are closely related to simian immunodeficiency virus (siv) and it has been postulated that the hiv2 epidemic might have arisen by cross-species spread of siv into the human population in west africa. to gain some insight into the possible basis for cross protection between these two closely related viruses, the t-helper responses to 15 synthetic peptides from siv gag syntheti ...19958830117
conformational stability of dimeric hiv-1 and hiv-2 reverse transcriptases.the dissociation of dimeric reverse transcriptase (rt) of the human immunodeficiency virus (hiv) types 1 and 2 has been investigated using acetonitrile as a dissociating agent. the equilibrium transitions were monitored by combining different approaches (fluorescence spectroscopy, polymerase activity assay, and size-exclusion hplc). the dissociation of rt induced a complete loss of polymerase activity and a 25% increase of the intrinsic fluorescence. it is fully reversible, and the midpoints of ...19958845359
prevalence of blood-borne viruses among intravenous drug users and alcoholics in hiroshima, japan.we investigated the prevalence of human immunodeficiency viruses-1 and 2 (hiv-1 and hiv-2), human t-lymphotropic virus type i and ii, hepatitis b virus (hbv), hepatitis c virus (hcv) and hepatitis d virus among intravenous drug users (ivdu) in hiroshima, japan, where little is known about their present levels. from june to december 1993, serum samples were collected from 47 ivdu and 98 alcoholics in hiroshima, japan, and examined for markers of virus infection. the prevalence of antibody to hcv ...19958845404
hiv-1 gp41 selectively inhibits spontaneous cell proliferation of human cell lines and mitogen- and recall antigen-induced lymphocyte proliferation.human immunodeficiency virus type 1 (hiv-1) transmembrane glycoprotein 41 (gp41) contains an immunosuppressive domain (env amino acids 583-599). previous studies by us and others using recombinant soluble gp41 (rsgp41; amino acids 539-684) and immunosuppressive peptide (1sp; a gp41 peptide, amino acids 583-599) have shown that hiv-1 gp41 by the immunosuppressive domain could bind to several proteins on human t, b and monocyte cell lines, and also to normal human peripheral blood mononuclear cell ...19958847089
human immunodeficiency virus (hiv) antigen testing to detect hiv infection in female sex workers in singapore.human immunodeficiency virus (hiv) infection is characterised by seroconversion after a ¿window¿ period of 2 to 3 months. after this period antibodies are usually detectable by screening tests (enzyme immunoassay or particle agglutination) confirmed by western blot analysis. we studied 1000 newly enrolled female sex workers who had not been previously tested for hiv to assess the usefulness of hiv antigen testing to improve the efficacy of hiv infection detection. blood was taken at enrollment f ...19958849183
clinico-epidemiological patterns of hiv infection in std patients in ibadan.the hiv-seropositive subjects identified among the std clinic patients seen at a special treatment clinic between 1989 and 1990 were studied to determine the epidemiological and clinical trends of hiv infection in these patients, and to demonstrate any association between the stds and hiv- seropositivity. thirty-seven out of the 581 patients investigated have been confirmed hiv-seropositive by western bolt. the prevalence of hiv infection was 6.4%. anti-hiv-1 antibody prevalence (3.6%) was highe ...19958886145
severe illness in african children with diarrhoea: implications for case management strategies.to identify clinical disorders associated with severe illness in african children with diarrhoea, we studied a group of under-5-year-olds with diarrhoea who had been brought to a large public hospital in central cote d'ivoire. the general condition of children with diarrhoea was assessed and classified according to criteria recommended by who, and then used as a nonspecific indicator of severity. of the 264 children with diarrhoea who were enrolled in the study, 196 had nonsevere illness and 68 ...19958907771
detection of circulating human immunodeficiency virus type 2 in plasma by reverse transcription polymerase chain reaction.genomic rna was detected using a reverse transcription (rt) nested polymerase chain reaction (pcr) method on plasma from 24 hiv2-infected patients. results were interpreted based on immune and clinical status and results of plasma and cellular viraemia assays. amplification of rna extracted from plasma was positive in 13 of the 24 cases studied (54%). there was a negative correlation between the detection of rna in plasma and the patients' cd4+ cell counts: all 5 patients with counts below 200 x ...19958834757
antiviral and resistance studies of ag1343, an orally bioavailable inhibitor of human immunodeficiency virus protease.ag1343 ([3s-(3r*,4ar*,8ar*,2's*,3's*)]-2-[2' hydroxy-3'-phenylthiomethyl-4'-aza-5'-oxo-5'-(2''-methyl-3''-hydro xy-phenyl) pentyl]-decahydroiso-quinoline-3-n-t-butylcarboxamide methanesulfonic acid) is a selective, nonpeptidic inhibitor of human immunodeficiency virus (hiv) protease (ki = 2 nm) that was discovered by protein structure-based drug design methodologies. ag1343 was effective against the replication of several laboratory and clinical hiv type 1 (hiv-1) or hiv-2 isolates including pyr ...19968834868
a model for alignment of env v1 and v2 hypervariable domains from human and simian immunodeficiency viruses.hiv-1 env gene encodes a multifunctional glycoprotein that is involved in virus infectivity, interactions between the virus and the host immune system, and phenotypic characteristics of virus isolates in culture. a number of env functions map by genetic analysis to v3, one of five hypervariable domains that compose the surface component of env gp120. v1 and v2 hypervariable domains of env also contribute to the phenotype of hiv-1, although relationships between v1 and v2 genotypes and biological ...19968844021
evaluation of a new third generation anti-hiv-1/anti-hiv-2 assay with increased sensitivity for hiv-1 group o.although the hiv-1 group o virus found in two persons of cameroonian origin has been described in 1990 (de leys et al., 1990), sera from group o infected individuals became available only recently. several studies showed that some of the anti-hiv-1/hiv-2 screening tests failed to detect all of these samples (loussert-ajaka et al., 1994; simon et al., 1994; schable et al., 1994; gürtler et al., 1995). in the current version of an anti-hiv-1/anti-hiv-2 screening assay, namely the vironostika hiv u ...19968844618
cdc42 and rac1 are implicated in the activation of the nef-associated kinase and replication of hiv-1.the negative factor (nef) of human and simian immunodeficiency viruses (hiv-1, hiv-2 and siv) is required for high levels of viremia and progression to aids. additionally, nef leads to cellular activation, increased viral infectivity and decreased expression of cd4 on the cell surface. previously, we and others demonstrated that nef associates with a cellular serine kinase (nak) activity. recently, it was demonstrated that nak bears structural and functional similarity to p21-activated kinases ( ...19968994833
[course of hiv2 seroprevalence at the national hospital of niamey (niger)].about the 25,368 serological tests done among the different groups of the population at the biological laboratory of the national hospital of niamey from march 1987 to may 1990, the author studied the seroprevalence evolution of the infection hiv2. a regular fall for the hiv2 appeared in this period. the author tries to explain this fall of the hiv2 in a country newly infected by the hiv by the lower infectivity of the hiv2 and/or a failure to adjust of this virus in niger.19968998417
cd8+ cells from asymptomatic human immunodeficiency virus-infected individuals suppress superinfection of their peripheral blood mononuclear cells.most human immunodeficiency virus (hiv)-infected individuals show evidence of infection by only one strain of the virus despite possible frequent contact with multiple strains. the reason(s) for the emergence of a dominant strain of virus in hiv-infected people and the mechanism(s) which prevent other strains from establishing an infection is not known. in the present study, we demonstrate that peripheral blood mononuclear cells (pbmc) of asymptomatic hiv-infected individuals can resist producti ...19969000085
[occurrence of false positives in tests with synthetic peptides for the analysis of antibodies against the human immunodeficiency virus type 2 (hiv-2) in brazilian patients infected with the human immunodeficiency virus type 1 (hiv-1)]. 19969011891
chemical trapping of ternary complexes of human immunodeficiency virus type 1 integrase, divalent metal, and dna substrates containing an abasic site. implications for the role of lysine 136 in dna binding.we report a novel assay for monitoring the dna binding of human immunodeficiency virus type 1 (hiv-1) integrase and the effect of cofactors and inhibitors. the assay uses depurinated oligonucleotides that can form a schiff base between the aldehydic abasic site and a nearby enzyme lysine epsilon-amino group which can subsequently be trapped by reduction with sodium borohydride. chemically depurinated duplex substrates representing the u5 end of the hiv-1 dna were initially used. we next substitu ...19968910309
antiviral activity and mechanism of action of calanolide a against the human immunodeficiency virus type-1.calanolide a, recently discovered in extracts from the tropical rainforest tree, calophyllum lanigerum, is a novel inhibitor of the human immunodeficiency virus (hiv) type 1. the compound is essentially inactive against strains of the less common hiv type 2. the present study focused on the further characterization of the selective antiviral activity and mechanism of action of calanolide a. the compound inhibited a wide variety of laboratory strains of hiv type 1, with ec50 values ranging from 0 ...19968930167
activation of pak by hiv and siv nef: importance for aids in rhesus macaques.the primate lentiviruses, human immunodeficiency virus types 1 and 2 (hiv-1 and hiv-2) and simian immunodeficiency virus (siv), encode a conserved accessory gene product, nef. in vivo, nef is important for the maintenance of high virus loads and progression to aids in siv-infected adult rhesus macaques. in tissue culture cells expressing nef, this viral protein interacts with a cellular serine kinase, designated nef-associated kinase.19968939608
nuclear import and cell cycle arrest functions of the hiv-1 vpr protein are encoded by two separate genes in hiv-2/siv(sm).the vpr genes of human and simian immunodeficiency viruses (hiv/siv) encode proteins which are packaged in the virus particle. hiv-1 vpr has been shown to mediate the nuclear import of viral reverse transcription complexes in non-dividing target cells (e.g. terminally differentiated macrophages), and to alter the cell cycle and proliferation status of the infected host cell. members of the hiv-2/siv(sm) group encode, in addition to vpr, a related protein called vpx. because these two proteins sh ...19968947037
serial cd4 and cd8 t-lymphocyte counts and associated mortality in an hiv-2-infected population in guinea-bissau.in an urban community in guinea-bissau, we followed a cohort of human immunodeficiency virus type 2 (hiv-2) seropositive individuals (n = 47) and seronegative controls (n = 82). t-lymphocyte subset determinations were done in 1988, 1990, and 1992. serial determinations of cd4 percentages, cd8 percentages, and cd4/cd8 ratios for the same individual were stable for 31 seropositive and 51 seronegative individuals with repeated measurements. we found no significant differences in the changes during ...19968948374
baboon endogenous virus evolution and ecology.cross-species transmission of retroviruses among primates has recently been recognized as the source of the current epidemics of hiv-1, hiv-2 and human t cell leukemia virus type 1 (htlv-1). the distribution of baboon endogenous virus among non-human primates resembles that of exogenous viruses and appears to be a consequence of different primate species sharing the same habitat.19968950816
distinct quasi-species in the blood and the brain of an hiv-2-infected individual.sequences of the hiv-2 envelope c2-c3 region were obtained after direct pcr amplification of proviral dna from the brain and peripheral blood mononuclear cells of an hiv-2-infected aids patient. tissue-specific sequences confirmed previous observations that hiv-2 is indeed present in the central nervous system of infected individuals. distinct but related quasi-species were present in these two different tissues of the same individual. residues at position 18 and 19 of the v3 loop and overall ch ...19968955063
novel l-lyxo and 5'-deoxy-5'-modified tsao-t analogs: synthesis and anti-hiv-1 activity.novel l-lyxo-tsao-t analogs with an inverted configuration at the c-4'-position of the sugar moiety and 5'-deoxy-5'-modified tsao-t derivatives have been prepared and evaluated for their inhibitory effect on human immunodeficiency virus type 1 (hiv-1) and type 2 (hiv-2) replication in cell culture. none of the compounds showed marked antiviral efficacy. the inactivity of the tsao-t derivatives may most likely be explained by either their different 4'-configuration or their different chemical str ...19968955510
inhibition of bovine immunodeficiency virus by anti-hiv-1 compounds in a cell culture-based assay.the bovine immunodeficiency virus (biv) and human immunodeficiency virus types 1 and 2 (hiv-1 and -2) are members of the lentivirus genus of retroviruses. although dna sequences of these viruses have diverged considerably, the biv genome organization, function of structural and regulatory genes, and replication cycle are very similar to that of hiv-1, making biv a potentially useful model to study compounds with anti-hiv-1 activity. a cell culture-based antiviral assay was developed to test comp ...19968955850
inhibition of human immunodeficiency virus replication by the sulfonated stilbene dye resobene.the anti-hiv sulfonated dye, resobene, was found to be a potent inhibitor of the attachment of hiv to target cells, the fusion of envelope- and cd4-expressing cells, and the cell-to-cell transmission of virus. resobene inhibited the infection of phenotypically distinct, established human cell lines and fresh human peripheral blood lymphocytes and macrophages by laboratory-derived isolates of human immunodeficiency virus type 1 (hiv-1) and type 2 (hiv-2), and a panel of biologically diverse prima ...19968955852
hiv-2 infection in 12 european residents: virus characteristics and disease progression.to assess the disease progression rate among 12 hiv-2-infected west european residents (nine of west african descent), compared with the disease progression rate among hiv-1-infected individuals of the same population, and the characteristics of the hiv-2 strains involved.19968970685
summary of track c: epidemiology and public health.aim: to review track c on epidemiology and public health. descriptive epidemiology: recent trends in the descriptive epidemiology are reported, for example, the rapid spread of hiv in certain asian countries and the more precise insights in the spread thanks to subtyping of hiv-1 (and hiv-2). transmission: there is now ample evidence that sexually transmitted diseases enhance the rate of transmission. viral load in the plasma of the mother is highly predictive for perinatal transmission. progres ...19968970718
the human immunodeficiency virus (hiv) type 2 envelope protein is a functional complement to hiv type 1 vpu that enhances particle release of heterologous retroviruses.we have recently shown that the envelope glycoprotein of the rod10 isolate of human immunodeficiency virus type 2 (hiv-2) has the ability to positively regulate hiv-2 viral particle release. the activity provided by the rod10 env was remarkably similar to that of the hiv-1 vpu protein, thus raising the possibility that the two proteins act in a related fashion. we now show that the rod10 env can functionally replace vpu to enhance the rate of hiv-1 particle release. when provided in trans, both ...19968970948
specific cleavage sites of nef proteins from human immunodeficiency virus types 1 and 2 for the viral proteases.human immunodeficiency virus type 2 (hiv-2) nef is proteolytically cleaved by the hiv-2-encoded protease. the proteolysis is not influenced by the absence or presence of the n-terminal myristoylation. the main cleavage site is located between residues 39 and 40, suggesting a protease recognition sequence, ggey-sqfq. as observed previously for nef protein from hiv-1, a large, stable core domain with an apparent molecular mass of 30 kda is produced by the proteolytic activity. cleavage of nef from ...19968971042
bile pigments as hiv-1 protease inhibitors and their effects on hiv-1 viral maturation and infectivity in vitro.using recently developed molecular-shape description algorithms, we searched the available chemical directory for known compounds similar in shape to the potent hiv-1 protease inhibitor merck l-700,417; 15 compounds most similar in shape to the inhibitor were selected for testing in vitro. four of these inhibited the protease at 100 microm or less and the most active of the four were the naturally occurring pigments biliverdin and bilirubin. biliverdin and bilirubin inhibited recombinant hiv-1 p ...19968973584
binding properties of human immunodeficiency virus type-2 (hiv-2) rna corresponding to the packaging signal to its nucleocapsid protein.the nucleocapsid (nc) protein of human immunodeficiency virus type-1 (hiv-1) contains two zinc finger motifs (zfms), and binds specifically to the packaging signal which is located in the 5' leader sequence of the viral genomic rna between the first splice donor and the gag initiator codon (aug). in this study, we analyzed the specificity of the binding of the corresponding region of hiv-2 (region 3) to its nc protein (ncp8), by performing a competitive ultraviolet (uv) cross-linking assay using ...19968886267
t cell apoptosis in human immunodeficiency virus type 2- and simian immunodeficiency virus-infected macaques.recent evidence suggests that t cell apoptosis could be involved in the pathogenesis of hiv infection. in addition, lymphocyte apoptosis has been described in siv-infected macaques that developed simian aids. to investigate further the role of apoptosis in aids pathogenesis, we studied lymphocytes of hiv-2-infected cynomolgus macaques that did not develop simian aids. we compared apoptosis of lymphocytes from animals infected with non-pathogenic hiv-2 to that in macaques infected with pathogenic ...19968887474
rapid sequon evolution in human immunodeficiency virus type 1 relative to human immunodeficiency virus type 2. 19968891118
development of a chronically catheterized maternal-fetal macaque model to study in utero mother-to-fetus hiv transmission: a preliminary report.the lack of a representative animal model that permits frequent in utero fetal blood sampling is a major limiting factor for the study of maternal-fetal hiv transmission. therefore, we have developed a maternal-fetal virus infection model using chronically catheterized macaques to simultaneously study the time-course of viral infection in the mother and the response of the fetus to maternal hiv infection. pregnant macaques were infected with 10(3) infectious units of hiv-2(287); every 3 days blo ...19968892043
infectivities of human and other primate lentiviruses are activated by desialylation of the virion surface.the envelope protein, gp120, of human immunodeficiency virus type 1 (hiv-1) is heavily glycosylated and sialylated. the heavy sialylation greatly affects the physical properties of the protein, as it resolves into a wide acidic ph range despite the basic pi value predicted for its polypeptide backbone (b. s. stein and e. g. engleman, j. biol. chem. 265:2640-2649, 1990). however, the functional significance of the heavy sialylation remains elusive. here, we show that desialylation of hiv-1 with n ...19968892864
inhibition of human immunodeficiency virus type 1 and type 2 tat function by transdominant tat protein localized to both the nucleus and cytoplasm.we introduced various mutations into the activation and rna binding domains of human immunodeficiency virus type 1 (hiv-1) tat in order to develop a novel and potent transdominant tat protein and to characterize its mechanism of action. the different mutant tat proteins were characterized for their abilities to activate the hiv ltr and inhibit the function of wild-type tat in trans. a tat protein containing a deletion of the basic domain (tat(delta)49-57) localized exclusively to the cytoplasm o ...19968892930
possible role of the v3 domain of gp120 in resistance to an amphotericin b derivative (ms8209) blocking human immunodeficiency virus entry.ms8209, an amphotericin b derivative blocking human immunodeficiency virus type 1 (hiv-1) entry after cd4 binding, neutralized the hiv-2 strains eho and rod10 but not rod(cem). in the v3 domain of gp120, rod(cem) differed from rod10 at two positions (a threonine instead of an isoleucine at position 312 and an arginine instead of a glutamine at position 329), and drug resistance was conferred to hiv-1 by substitution of the rod(cem) v3 but not the rod10 v3. v3 mutations may prevent the interactio ...19968892962
prevalence of hiv-1, hiv-2 and htlv antibody, in fortaleza, ceara, brazil, 1993-1994.to evaluate the respective part of hiv-1, hiv-2, and human t lymphotropic virus (htlv) infection in fortaleza, the principal city of the ceara state (northeast of brazil), a cross-sectional seroepidemiological survey was conducted from july 1993 to february 1994 in 6 selected groups: pregnant women, tuberculosis (tb) patients, sexually transmitted disease (std) patients, female and male commercial sex workers (csws) and prisoners. sera were screened by mixt hiv-1/hiv-2 commercial enzyme immunoas ...19968894828
receptor interference mediated by the envelope glycoproteins of various hiv-1 and hiv-2 isolates.the envelope glycoprotein of human immunodeficiency virus type 1 (hiv-1) plays a major role in the down-regulation of its receptor, cd4. this down-regulation, at least in part, is caused by the formation of gp160-cd4 intracellular complexes which fail to transport out of the endoplasmic reticulum (er). in this report, we have evaluated the ability of envelope glycoproteins from various isolates to block cd4 transport within the endoplasmic reticulum. using a recombinant vaccinia virus expression ...19968896248
immunogenicity and protective efficacy of a human immunodeficiency virus type 2 recombinant canarypox (alvac) vaccine candidate in cynomolgus monkeys.the efficacy of a recombinant human immunodeficiency virus (hiv) type 2 canarypox (alvac hiv-2) vaccine candidate given alone or in combination with hiv-2 envelope gp125 or hiv-2 v3 synthetic peptides was investigated in 14 cynomolgus monkeys. high antibody titers to hiv-2 gp125 were demonstrated in monkeys given booster immunizations with gp125. neutralizing antibody titers were low (< or = 20) in all monkeys except 2. significant lymphocyte proliferative responses to killed hiv-2 virions were ...19968896498
evaluation of chiron hiv-1/hiv-2 recombinant immunoblot assay.in a study to determine the reliability, sensitivity, and specificity of the chiron riba hiv-1/hiv-2 strip immunoblot assay (riba hiv-1/2 sia) for confirmation of human immunodeficiency virus type 1 (hiv-1) and hiv-2 antibodies, 1,263 serum samples from various populations in the united states, caribbean, africa, india, and thailand were evaluated by riba hiv-1/2 sia, and the results were compared with those obtained by an hiv-1 western blot (immunoblot) assay. all sera were tested by hiv enzyme ...19968897158
Refresh
firstprev
...11121314151617181920...
nextlast
Displaying items 1001 - 1100 of 2683