| [the seroepidemiology of infection with the human immunodeficiency virus type 2 (hiv-2) in spain (1990). the spanish group for the study and follow-up of hiv-2 infection]. | | 1992 | 1552768 |
| site-specific cleavage of the transactivation response site of human immunodeficiency virus rna with a tat-based chemical nuclease. | tat, an essential transactivator of gene transcription in the human immunodeficiency virus (hiv), is believed to activate viral gene expression by binding to the transactivation response (tar) site located at the 5' end of all viral mrnas. the tar element forms a stem-loop structure containing a 3-nucleotide bulge that is the site for tat binding and is required for transactivation. here we report the synthesis of a site-specific chemical ribonuclease based on the tar binding domain of the hiv t ... | 1992 | 1565648 |
| human immunodeficiency virus type 2 infection and fusion of cd4-negative human cell lines: induction and enhancement by soluble cd4. | we describe human immunodeficiency type 2 (hiv-2) strains which induce cell-to-cell fusion and infect certain cd4- human cell lines. soluble cd4 (scd4) induces or enhances fusion by most hiv-2 strains tested. soluble cd4-immunoglobulin g chimeras and conjugates of scd4 and antibody to the third domain of cd4 block hiv-2 fusion of cd4- cells. we conclude that hiv-2 can enter cd4- cells via an alternative cell surface receptor to cd4. while some strains entered efficiently, others retained a depen ... | 1992 | 1583722 |
| cytoplasmic domain truncation enhances fusion activity by the exterior glycoprotein complex of human immunodeficiency virus type 2 in selected cell types. | to investigate the glycoprotein determinants of viral cytopathology, we constructed chimeric env genes between a noncytopathic strain of human immunodeficiency virus type 2 (hiv-2), designated hiv-2/st, and a highly fusogenic and cytopathic variant derived from this virus. expression of the resulting chimeric glycoproteins indicated that efficient syncytium formation in the human t-cell line sup t1 mapped to the c-terminal region of the transmembrane (tm) glycoprotein subunit. in this region, th ... | 1992 | 1583738 |
| evolutionarily conserved ets family members display distinct dna binding specificities. | members of the ets family of proto-oncogenes encode sequence-specific transcription factors that bind to a purine-rich motif centered around a conserved gga trinucleotide. ets binding sites have been identified in the transcriptional regulatory regions of multiple t cell genes including the t cell receptor alpha and beta (tcr-alpha and -beta) enhancers and the il-2 enhancer, as well as in the enhancers of several t cell-trophic viruses including maloney sarcoma virus, human leukemia virus type 1 ... | 1992 | 1569404 |
| human immunodeficiency virus type 2 infection in the united states. epidemiology, diagnosis, and public health implications. | | 1992 | 1578597 |
| comparative analysis of rev function in human immunodeficiency virus types 1 and 2. | the rev proteins of the related but distinct human immunodeficiency virus types 1 and 2 (hiv-1 and hiv-2) display incomplete functional reciprocity. one possible explanation for this observation is that hiv-2 rev is unable to interact with the hiv-1 rev-response element (rre1). however, an analysis of the biological activity of chimeric proteins derived from hiv-1 and hiv-2 rev reveals that this target specificity does not map to the rev rna binding domain but is instead primarily determined by ... | 1992 | 1602545 |
| role of the fusogenic peptide sequence in syncytium induction and infectivity of human immunodeficiency virus type 2. | syncytium induction is a characteristic feature of infection by human immunodeficiency virus (hiv) in vitro. the hydrophobic amino terminus of the transmembrane glycoprotein of hiv type 1 is an essential determinant of virus entry into the target cell population and the formation of syncytia in cell culture. to define the role of the hiv type 2 fusion peptide during infection and syncytium formation, we introduced 8 amino acid substitutions into the hydrophobic amino terminus of gp41, changing e ... | 1992 | 1602558 |
| in vivo genetic variability of the human immunodeficiency virus type 2 v3 region. | the principal neutralizing epitope of the human immunodeficiency virus type 1 (hiv-1) lies between two invariant cysteines in the third variable region (v3) of the viral envelope (gp120), and its amino acid sequence varies among different hiv-1 isolates. hiv-2 carries an analogous amino acid sequence between two cysteines of the v3 regions, but its functional similarity with the hiv-1 principal neutralizing epitope is uncertain. we studied the degree of genetic variation of the hiv-2 v3 region i ... | 1992 | 1602560 |
| potent and selective inhibition of human immunodeficiency virus (hiv)-1 and hiv-2 replication by a class of bicyclams interacting with a viral uncoating event. | a series of bicyclams have been shown to be potent and selective inhibitors of human immunodeficiency virus (hiv). the compounds are inhibitory to the replication of various hiv-1 and hiv-2 strains in various human t-cell systems, including peripheral blood lymphocytes, at 0.14-1.4 microm, without being toxic to the host cells at 2.2 mm. the bicyclam jm2763 is active against 3'-azido-3'-deoxythymidine (zidovudine; azt)-resistant hiv-1 strains and acts additively with azt. mechanism of action stu ... | 1992 | 1608936 |
| vaccine protection of chimpanzees against challenge with hiv-1-infected peripheral blood mononuclear cells. | because human immunodeficiency virus (hiv) can be transmitted as cell-free virus or as infected cells (cell-associated virus), vaccines must protect against infection by both viral forms. vaccine-mediated protection of nonhuman primates against low doses of cell-free hiv-1, hiv-2, or simian immunodeficiency virus (siv) has been demonstrated. it is now shown that multiple immunizations of chimpanzees with hiv-1 antigens protected against infection with cell-associated virus. protection can persis ... | 1992 | 1609280 |
| neurosyphilis and human immunodeficiency virus type 2 infection. | | 1992 | 1580801 |
| replication of hiv-1 and hiv-2 in human bone marrow cultures. | the bone marrow is a target organ for the human immunodeficiency virus (hiv), but the mechanisms by which suppression of hematopoiesis occurs during the course of hiv infection are not well understood. to study this issue, the effect of several different hiv-1 isolates (monotrophic and lymphotrophic) and one hiv-2 isolate on in vitro colony formation by bfu-e and cfu-gm from normal human marrow were examined. the monotrophic strain ad-87 (m) failed to replicate in marrow cultures as documented b ... | 1992 | 1585651 |
| chemical synthesis of a biotinylated derivative of the simian immunodeficiency virus protease. purification by avidin affinity chromatography and autocatalytic activation. | the protease from simian immunodeficiency virus (siv) was chemically synthesized by automated solid-phase technology as an nh2-terminally extended derivative, capped with biotin. biotin-linker-(siv protease (1-99)): the linker segment, gly-gly-asp-arg-gly-phe-ala-ala, corresponds to the amino acid sequence preceding that of the protease in the siv gag/pol precursor polyprotein. accordingly, the ala-pro bond joining the octapeptide linker to the protease constitutes a site naturally cleaved by th ... | 1992 | 1587812 |
| variability of hiv infections. | genetic variation is the hallmark of infections with lentiviruses in general and the human immunodeficiency viruses (hiv-1, hiv-2) in particular. this article reviews both experimental evidence for the variability of the hiv genome during the course of an individual infection and mathematical models that outline the potential importance of antigenic variation as a major factor to drive disease progression. the essential idea is that the virus evades immune pressure by the continuous production o ... | 1992 | 1619947 |
| infection of macaca nemestrina by human immunodeficiency virus type-1. | after observations that macaca nemestrina were exceptionally susceptible to simian immunodeficiency virus and human immunodeficiency virus type-2 (hiv-2), studies of hiv-1 replication were initiated. several strains of hiv-1, including a recent patient isolate, replicated in vitro in peripheral blood mononuclear cells (pbmcs) and in cd4-positive m. nemestrina lymphocytes in a cd4-dependent fashion. eight animals were subsequently inoculated with either cell-associated or cell-free suspensions of ... | 1992 | 1621083 |
| [multicenter study of the prevalence of type 2 human immunodeficiency virus infection in spain (1990)]. | hiv-2 is a new retrovirus which may produce aids and has been mainly described in individuals from west africa. more than 400 cases have been reported in france and portugal while in spain very few cases of hiv-2 infection have been reported with few studies having been made concerning the prevalence of the disease. this multicentric study analyzes the prevalence of hiv-2 infection in subjects of different risk groups in spain and evaluates the diagnostic efficacy of different methodologies. | 1992 | 1635394 |
| detection of antibodies to human immunodeficiency virus type 2 (hiv-2) in blood donor sera using united states assay methods for anti-hiv type 1. | twelve serum samples from french blood donors that were uniformly reactive in tests for antibody to human immunodeficiency virus type 2 (anti-hiv-2) also were reactive in 92 to 100 percent of tests with three anti-hiv type 1 (anti-hiv-1) enzyme-linked immunoassays currently in widespread use for donor screening in the united states. supplemental tests for anti-hiv-1 on these anti-hiv-2-reactive samples differed in their responses. all samples reacted in a licensed anti-hiv-1 western blot, but th ... | 1992 | 1626342 |
| compliance with infection control procedures among california orthodontists. | we conducted a survey of a random sample of california orthodontists and of general dentists to compare their infection control procedures. questionnaires were returned by 124 orthodontists (56% response rate) and 126 general dentists (61% response rate). eighteen questions were asked covering practice profile, perception of risk from hepatitis b virus (hbv) and human immunodeficiency virus (hiv), exposure to blood, barrier protection used, and sterilization and disinfection procedures. gloves a ... | 1992 | 1626533 |
| functional mapping of the rev-responsive element of human immunodeficiency virus type 2 (hiv-2): influence of hiv-2 envelope-encoding sequences on hiv-1 gp120 expression in the presence or absence of rev. | the human immunodeficiency virus type 1 (hiv-1) regulatory protein rev stimulates expression of structural viral proteins via a target response element (rre) located within gag-pol and env mrnas. to analyse the hiv-2 rev trans-activation effect on the expression of the envelope protein, we cloned a functionally active hiv-2 rev cdna and showed that it contained four exons. using transient expression assays, we mapped a 353 bp rre fragment within the env gene of hiv-2 on which both hiv-1 and hiv- ... | 1992 | 1629702 |
| human infection by genetically diverse sivsm-related hiv-2 in west africa. | our understanding of the biology and origins of human immunodeficiency virus type 2 (hiv-2) derives from studies of cultured isolates from urban populations experiencing epidemic infection and disease. to test the hypothesis that such isolates might represent only a subset of a larger, genetically more diverse group of viruses, we used nested polymerase chain reactions to characterize hiv-2 sequences in uncultured mononuclear blood cells of two healthy liberian agricultural workers, from whom vi ... | 1992 | 1641038 |
| multicentric kaposi's sarcoma in a 5-year-old human immunodeficiency virus-negative renal allograft recipient. | we describe the clinical and pathologic features of a case of pediatric multicentric kaposi's sarcoma (ks) associated with allograft transplantation in a human immunodeficiency virus (hiv)-negative child. a lethal polyadenopathic and visceral ks occurred in a 5-year-old caribbean boy who had undergone an allogenic renal transplantation for diffuse mesangial sclerosis with end-stage renal failure 4 months previously. the hiv-1 and hiv-2 serologies were negative. despite its rarity, ks must be con ... | 1992 | 1644441 |
| complementation of human immunodeficiency virus glycoprotein mutations in trans. | the external glycoproteins of human immunodeficiency virus type 1 (hiv-1) (gp120) and hiv-2 (gp105) are responsible for binding the cellular receptor cd4. the proteins are functionally identical although their affinity for cd4 varies, with gp120 binding 10- to 20-fold more efficiently than gp105. to investigate the structural requirements for cd4 binding in each molecule we have constructed a number of hybrid glycoproteins in which sequences are exchanged between the two molecules via conserved ... | 1992 | 1645136 |
| functional analysis of long terminal repeats derived from four strains of simian immunodeficiency virus sivagm in relation to other primate lentiviruses. | the promoter activity of long terminal repeats (ltrs) of four strains of the simian immunodeficiency virus isolated from african green monkeys (sivagm) was compared with those of various ltrs derived from the other representative primate lentiviruses: human immunodeficiency virus type 1 (hiv-1), type 2 (hiv-2), siv from a rhesus monkey (sivmac), and siv from a mandrill (sivmnd). the expression of the ltrs was evaluated by monitoring chloramphenicol acetyltransferase production after transfection ... | 1991 | 1656599 |
| the first decade of human retroviruses: a nomenclature for the clinician. | the decade of the 1980s has provided at least 10 terms for human retroviruses, of which five are currently recognized as defining distinct human infectious disease agents. of these five, three are human t-cell lymphotropic viruses (htlv-i, htlv-ii, htlv-v) and two are human immunodeficiency viruses (hiv-1, hiv-2). hiv-1 and hiv-2 can cause the acquired immunodeficiency syndrome (aids), whereas htlv-i, htlv-ii, and htlv-v do not. htlv-i can cause a t-cell leukemia/lymphoma as well as a progressiv ... | 1991 | 1660967 |
| rna pseudoknots downstream of the frameshift sites of retroviruses. | rna pseudoknot structural motifs could have implications for a wide range of biological processes of rnas. in this study, the potential rna pseudoknots just downstream from the known and suspected retroviral frame-shift sites were predicted in the rous sarcoma virus, primate immunodeficiency viruses (hiv-1, hiv-2, and siv), equine infectious anemia virus, visna virus, bovine leukemia virus, human t-cell leukemia virus (types i and ii), mouse mammary tumor virus, mason-pfizer monkey virus, and si ... | 1991 | 1663382 |
| hiv-2 in the united kingdom--a review. | human immunodeficiency virus type 2 (hiv-2) was first recognised in 1986 and subsequently the infection was shown to be widespread in west africa. there have been few case reports from countries outside the african continent. in north america and europe the highest number of infections have been in portugal and france. twelve hiv-2 infections have been identified in the united kingdom (uk) and nine of the twelve had some connection with africa, mostly west africa; in three cases only "sub-sahara ... | 1991 | 1669765 |
| human immunodeficiency virus (hiv) infection in cd4+ t lymphocytes genetically deficient in lfa-1: lfa-1 is required for hiv-mediated cell fusion but not for viral transmission. | in the present study, we demonstrated that expression of the lfa-1 molecule is necessary for cell fusion and syncytia formation in human immunodeficiency virus (hiv)-infected cd4+ t lymphocytes. in contrast, the lack of expression of lfa-1 does not influence significantly cell-to-cell transmission of hiv. in fact, lfa-1- t lymphocytes obtained from a leukocyte adhesion deficiency patient were unable to fuse and form syncytia when infected with hiv-1 or hiv-2, despite the fact that efficiency of ... | 1991 | 1671082 |
| specific cell surface requirements for the infection of cd4-positive cells by human immunodeficiency virus types 1 and 2 and by simian immunodeficiency virus. | human cd4 was expressed on a range of mammalian cell lines. cd4+ non-primate cells, derived from rat, hamster, mink, cat, and rabbit, bind recombinant gp120 of human immunodeficiency virus type 1 (hiv-1) but are resistant to hiv-1 infection. cd4 expression on various human, rhesus, and african green monkey cell lines confers differential susceptibilities for hiv-1, hiv-2, and simian immunodeficiency (siv) strains. for example, cd4+ te671 rhabdomyosarcoma cells are sensitive to hiv-1 and hiv-2 bu ... | 1991 | 1673040 |
| field evaluation of alternative hiv testing strategy with a rapid immunobinding assay and an agglutination assay. | a rapid immunobinding assay ('hivchek', ortho) and an agglutination assay ('serodia-hiv', fujirebio) were evaluated as an alternative to enzyme-linked immunosorbent assay (elisa) and western blot under field conditions in africa for detection of antibody to human immunodeficiency virus (hiv). 7106 specimens were tested at 25 laboratories in kenya, ghana, senegal, and zaire. hivchek was used as a screening test, and serodia-hiv as a supplemental test to evaluate these assays in an alternative tes ... | 1991 | 1674306 |
| selective inhibitory activity of polyhydroxycarboxylates derived from phenolic compounds against human immunodeficiency virus replication. | polyhydroxycarboxylates (mw: 3,800-14,000) derived from phenolic (pdp) compounds have been found to inhibit the cytopathicity of hiv-1 and hiv-2 in mt-4 cells at concentrations that are not toxic to the host cells. the pdp compounds also inhibited syncytium formation in cocultures of molt-4 cells with hiv-1- or hiv-2-infected hut-78 cells. they also interfered with the binding of okt4a/leu3a monoclonal antibody (mab) to the cd4 receptor, the binding of anti-gp120 mab to hiv-1 gp120, and attachme ... | 1991 | 1675677 |
| antibody response to the negative regulatory factor (nef) in experimentally infected macaques: correlation with viremia, disease progression, and seroconversion to structural viral proteins. | the antibody response to structural and regulatory viral proteins was studied in 14 rhesus (macaca mulatta) and 6 cynomolgus (macaca fascicularis) macaques experimentally infected with hiv-2 or sivmac. to investigate the humoral antibody response to the negative regulatory factor (nef), the recombinant protein was expressed to high levels with recombinant vaccinia virus (vv). nef-specific antibodies were detected in 14 of 20 infected macaques (70%). in sera of all infected monkeys antibodies dir ... | 1991 | 1675823 |
| rheumatic manifestations in a patient with human immunodeficiency virus type 2 infection. | | 1991 | 1675851 |
| prevention of hiv-2 and sivsm infection by passive immunization in cynomolgus monkeys. | infection of macaques with simian immunodeficiency virus (siv) and human immunodeficiency virus type 2 (hiv-2) are useful models for studies of immunotherapy and vaccination against hiv as well as for testing of antiviral drugs. vaccine research showing protective immunity in immunized monkeys has indicated that it will be possible to develop a vaccine for prevention of human hiv infection, although many hurdles remain. the design of an hiv vaccine would be helped if the basis of the protective ... | 1991 | 1677743 |
| evidence of brain methyltransferase inhibition and early brain involvement in hiv-positive patients. | the myelopathy associated with human immunodeficiency virus (hiv) infection closely resembles that in subacute combined degeneration, a disorder of vitamin b12 metabolism. to investigate whether the disorders share a pathogenetic mechanism, s-adenosylmethionine (sam) and s-adenosylhomocysteine (sah) were measured in the cerebrospinal fluid (csf) of 20 hiv-seropositive patients and 30 hiv-negative patients who were undergoing lumbar puncture for other medical reasons. the hiv-seropositive patient ... | 1991 | 1678030 |
| peripheral facial nerve palsy related to hiv infection: relationship with the immunological status and the hiv staging in central africa. | twelve cases of infranuclear facial nerve palsy associated with infection by the human immunodeficiency virus in the heterosexual african are reported with clinical and immunological studies. eight cases were healthy hiv carriers, three patients manifested aids-related complex and one case fulfilled the cdc criteria for aids. nine patients had a typical bell's palsy, two presented cephalic herpes zoster infection with ramsay hunt syndrome and one, who suffered from progressive facial weakness, c ... | 1991 | 1680026 |
| cd8+ t cells from hiv-1-infected individuals inhibit acute infection by human and primate immunodeficiency viruses. | t lymphocytes expressing the cd8 surface antigen block hiv replication in cd4+ peripheral blood cells from hiv-infected individuals. we report here that cd4+ cells from hiv seronegative donors, when infected in vitro with hiv, also do not replicate virus when cocultured with cd8+ t cells from hiv-infected individuals. cd8+ cells from hiv-uninfected donors did not show this effect on virus replication. hla-restriction of the antiviral response was not observed, and virus-containing cells were not ... | 1991 | 1680028 |
| a mathematical model of vaccination against hiv to prevent the development of aids. | vaccination and post-exposure immunization against the human immunodeficiency viruses (hiv-1 and hiv-2) faces the problem of the extensive genetic and antigenic variability of these viruses. this raises the question of what fraction of all possible antigen strains of the virus must be recognized by the immune response to a vaccine to prevent development of acquired immunodeficiency disease (aids). the success of a vaccine can depend on the variability of the target epitopes. the different hiv va ... | 1991 | 1685238 |
| potent and selective inhibition of hiv-1 replication in vitro by a novel series of tibo derivatives. | in the search for compounds active against human immunodeficiency virus (hiv), we have found that members of a novel series of tetrahydro-imidazo[4,5,1-jk][1,4]-benzodiazepine-2(1h)-one and -thione (tibo) derivatives inhibit the replication of hiv-1, the main aetiological agent of aids, but not of hiv-2, or of any other dna or rna viruses. in five cell systems, hiv-1 is inhibited by tibo derivatives in nanomolar amounts, which are 10(4)-10(5) times lower than the cytotoxic concentration. the unp ... | 1990 | 1689015 |
| characterization of monoclonal antibodies that distinguish simian immunodeficiency virus isolates from each other and from human immunodeficiency virus types 1 and 2. | two monoclonal antibodies (mabs) against p27 and one against p17 of simian immunodeficiency virus (siv) from rhesus macaques were produced and characterized by reacting with disrupted, viral antigens on immunoblots. human immunodeficiency virus type 1 (hiv-1), hiv-2 and siv isolates from sooty mangabey, stump-tailed macaque, rhesus macaque and african green monkey (sivsm, sivstm, sivmac and sivagm) were used for comparative analysis. the p27 monoclonal antibodies he3 and fa2 reacted with sivmac ... | 1990 | 1689369 |
| establishment of a bioassay to determine serum levels of dextran sulfate and pentosan polysulfate, two potent inhibitors of human immunodeficiency virus. | dextran sulfate and pentosan polysulfate are two promising candidate anti-acquired immune deficiency syndrome (aids) drugs that have already been the subject of initial clinical trials in patients with aids. there is at present no reliable assay method to monitor blood drug levels in humans following the administration of either drug. we have now developed a sensitive bioassay system based on the inhibitory activity of the compounds against human immunodeficiency virus type 2 (hiv-2) in mt-4 cel ... | 1990 | 1690285 |
| the budding of defective human immunodeficiency virus type 1 (hiv-1) particles from cell clones persistently infected with hiv-1. | three cell clones producing large numbers of infectious or noninfectious particles of human immunodeficiency virus type 1 (hiv-1), designated m 10/lav-2, m 16/lav-3, and mt/lav-17, were isolated from persistently hiv-1-infected mt-4 cells. in m 10/lav-2, the hiv-1 proteins were defective in the cleavage of gag precursor protein, and the particles were doughnut-shaped with a double-ring structure. these particles were produced by budding at the cell surface from crescentic structures followed by ... | 1990 | 1691624 |
| production and characterization of a human monoclonal antibody, reactive with a conserved epitope on gp41 of human immunodeficiency virus type i. | a human epstein-barr virus-transformed lymphoblastoid b-cell line was generated from peripheral blood mononuclear cells (pbmc) of an asymptomatic human immunodeficiency virus type i (hiv-1) seropositive donor, which produces a human monoclonal antibody k14 (igg1), reactive with an epitope on the transmembrane part (gp41) of the envelope glycoprotein of hiv-1. this monoclonal antibody reacts with a lysate of hiv-1-infected h9 cells, gradient purified hiv-1, and a vaccinia recombinant hiv-1 gp160 ... | 1990 | 1692724 |
| hiv2 chronic infection of promonocytic cells. | hiv1 infection of mononuclear phagocytes is now well established, whereas hiv2 infection of these cells is less well documented. in this work, we studied the replication of the hiv2rod strain in the u-937 promonocytic cell line and compared it with that of the hiv1bru strain. p24 antigen and rt (reverse transcriptase) activity were assessed at regular intervals in cell-free supernatants, as was the infectiousness of the produced virus. in the case of hiv2, after a phase of high cell mortality, a ... | 1990 | 1693223 |
| differences in the interaction of hiv-1 and hiv-2 with cd4. | inhibition of infectivity, cytopathicity, and binding by soluble cd4 was determined for several human immunodeficiency virus (hiv)-1 and hiv-2 strains. although infectivity and binding of both groups were blocked equally well by okt4a, hiv-2 viruses were more refractory to inhibition by soluble cd4. rates of envelope shedding, as determined by thermal stability, did not differ between hiv-1 and hiv-2; however, scatchard plot analysis of radiolabeled virus binding revealed that fewer hiv-2 virion ... | 1990 | 1693676 |
| interference with human immunodeficiency virus (hiv) replication by cd8+ t cells in peripheral blood leukocytes of asymptomatic hiv carriers in vitro. | a long asymptomatic period is one of the characteristics of human immunodeficiency virus (hiv) infection, despite its fatal consequences. antiviral defense in hiv-infected individuals controls viral replication during this period. in the present study, we demonstrate that peripheral blood leukocytes (pbl) of asymptomatic hiv-1 carriers, following exogenous hiv-1 infection in vitro, do not support viral replication. these cells do not produce detectable amounts of reverse transcriptase or accumul ... | 1990 | 1693704 |
| retroviral expression in mononuclear blood cells isolated from a patient with osteopetrosis (albers-schönberg disease). | we report the presence of reverse transcriptase activity in the supernatant of long-term culture of mononuclear blood cells (monocytes and lymphocytes) isolated from a 27-year-old patient suffering from benign osteopetrosis. the enzyme was purified to homogeneity according to the technique of chandra and steel, by chromatography, first on deae-cellulose (de 52) and then on phosphocellulose (p11). after purification, the enzyme was characterized biochemically for its template specificity and ioni ... | 1990 | 1695060 |
| linear b-cell epitopes of the major core protein of human immunodeficiency virus types 1 and 2. | nine murine monoclonal antibodies directed to the major core protein p24 of human immunodeficiency virus type 1 (hiv-1) were obtained and then tested by using an epitope mapping system (pepscan) covering the whole p24hiv1 protein to characterize antigenic domains. four different linear epitopes were identified. monoclonal antibodies recognizing three of these epitopes also reacted to p26hiv2 in western blotting (immunoblotting). a monoclonal antibody specific for the fourth epitope, located at p ... | 1990 | 1696638 |
| multiple antigenic epitopes expressed on gag proteins, p26 and p15, of a human immunodeficiency virus (hiv) type 2 as defined with a library of monoclonal antibodies. | thirty-two hybridoma clones producing monoclonal antibody (mab) against hiv-2[gh-1] were established from mice immunized with np-40-disrupted purified whole virus of a ghanaian isolate of human immunodeficiency virus type 2 (hiv-2), strain hiv-2[gh-1]. of these 32 mabs, 20 reacted with p26 and the other mabs recognized p15 of the hiv-2[gh-1] isolate. from the results of serological characterization by these mabs, p26 and p15 were identified as capsid proteins and matrix protein, respectively, of ... | 1990 | 1697178 |
| alpha-(1-3)- and alpha-(1-6)-d-mannose-specific plant lectins are markedly inhibitory to human immunodeficiency virus and cytomegalovirus infections in vitro. | the alpha-(1-3)-d-mannose- and alpha-(1-6)-d-mannose-specific agglutinins (lectins) from galanthus nivalis, hippeastrum hybrid, narcissus pseudonarcissus, and listera ovata inhibited infection of mt-4 cells by human immunodeficiency virus types 1 and 2 (hiv-1 and hiv-2) and simian immunodeficiency virus at concentrations comparable to the concentrations at which dextran sulfate (molecular weight, 5,000 [ds-5000]) inhibits these viruses (50% effective concentration, 0.2 to 0.6 microgram/ml). unli ... | 1991 | 1645507 |
| full-length and truncated versions of the hepatitis b virus (hbv) x protein (px) transactivate the cmyc protooncogene at the transcriptional level. | the products of the human hepatitis b virus (hbv) and woodchuck hepatitis b virus x genes (pxs) transactivate homologous and heterologous genes including the hbv-x and core promoters, the human immunodeficiency viruses 1 (hiv-1) and 2 (hiv-2) long terminal repeats and the beta interferon regulatory sequences. we report here that px is also able to influence the expression of both extrachromosomal transfected c-myc regulatory sequences and endogenous c-myc gene. px acts by increasing transcriptio ... | 1991 | 1645550 |
| antibodies to gag gene coded polypeptides of type d retroviruses in healthy people from guinea-bissau. | antibodies to proteins of mason-pfizer monkey virus (m-pmv) were screened in sera from 61 healthy donors living in guinea-bissau (4 hiv-1 and hiv-2 antibody positive hiv = human immunodeficiency virus), from 19 healthy french european blood donors, and from 9 french patients with induced immunodeficiency prior to bone marrow transplantation (all hiv-1 antibody negative). in 30 (49%) of the african sera tested, antibodies reacting against p27 and/or p14 were detected by western blot. some of thes ... | 1991 | 1650766 |
| [application of sensitive reverse transcriptase assay to human immunodeficiency virus (hiv) type 2]. | sensitive reverse transcriptase assay was applied to human immunodeficiency virus type 2. the kinetics of this assay, stability of the enzyme and the effect of bsa to this assay indicated that the condition of this assay should be 37 degrees c in reaction temperature. the sensitivity of this assay increased by adding more than 10 micrograms/ml of bsa. the sensitivity of this assay is at least four times more than that of cpe assay using molt-4 cell. other hiv-2 isolate, lav-2 in culture medium w ... | 1990 | 1700034 |
| association of antibodies blocking hiv-1 gp 160-scd4 attachment with virus neutralizing activity in human sera. | sera, from hiv-1 and hiv-2 seropositive individuals, were tested for the presence of antibodies able to inhibit the binding (bi) of hiv-iiib gp 160 (produced in mammalian cells using a vaccinia expression system) to the extracellular portion of the cd4 receptor. a competition enzyme immunoassay (eia) with soluble cd4 (scd4) was used. bi antibodies were highly prevalent among hiv-1 seropositives but not in hiv-2 infected individuals. attempts to localize the binding site for these bi antibodies o ... | 1990 | 1697332 |
| soluble cd4 enhances simian immunodeficiency virus sivagm infection. | the cd4 molecule is expressed on t-helper cells and serves as the cellular receptor for the human immunodeficiency virus types 1 and 2 (hiv-1 and hiv-2) and for the simian immunodeficiency viruses sivmac and sivagm. hiv-1, hiv-2, and sivmac infectivity can be blocked by monoclonal antibodies (mabs) directed against the cd4 molecule and by soluble cd4 proteins (scd4). in the present study, we demonstrated not only lack of inhibition, but 10- to 100-fold scd4-dependent enhancement of sivagm infect ... | 1990 | 1700834 |
| comparative studies on tat mutants of three primate lentiviruses. | a frame-shift tat gene mutant of human immunodeficiency virus type 1 (hiv-1), which showed no detectable trans-activation potential, was constructed in vitro. upon transfection, this clone directed the synthesis of virus mrnas, gag proteins and virion-associated reverse transcriptase (rt) at a low level as was observed with the tat mutants of hiv-2 and simian immunodeficiency virus isolated from african green monkey (sivagm). using these mutant viruses, trans-activation efficiency of viral gene ... | 1990 | 1700693 |
| characterization of monoclonal antibodies directed against distinct conserved epitopes of human immunodeficiency virus type 1 core proteins. | two mouse hybridoma cell lines secreting antibodies to the human immunodeficiency virus (hiv) p25 major core protein and its precursors p55 and p41, were developed after immunization with the highly cytopathic zaïrian hiv-1 isolate, ndk. these monoclonal antibodies also react with the gag gene products from hiv-1-bru prototype and present cross reaction with hiv-2-rod, and siv-agm. they map into topographically distinct areas of p25 and define epitopic regions topographically separated from thos ... | 1990 | 1703272 |
| functional comparison of transactivation by human retrovirus rev and rex genes. | the effect of rev-responsive element deletion on human immunodeficiency virus type 1 (hiv-1) and type 2 (hiv-2) gene expression was examined. the phenotypes of hiv-1 and hiv-2 provirus dnas lacking the rev-responsive element, as determined by transfection experiments, were indistinguishable from those of virus dnas carrying rev gene mutations. by using rev-response elements derived from these two viruses, we developed two monitoring systems to evaluate the functionality of hiv-1 rev, hiv-2 rev, ... | 1990 | 1700826 |
| cross-reactivity with sivmac in east african hiv-1-positive sera: evidence against double infection with hiv-1 and a sivmac/hiv-2-like virus. | igg antibodies reactive with simian immunodeficiency virus isolated from a rhesus monkey suffering from simian acquired immunodeficiency syndrome (sivmac, strain 239, a virus which is very closely related to human immunodeficiency virus type 2-hiv-2) were found in 18 of 120 swedish and 8 of 11 east african confirmed hiv-1 antibody positive (hiv-1 ab+) sera, both by enzyme immunoassay and electrophoretic immunoblotting (p = 1 x 10(-6). in electrophoretic immunoblotting most of the cross-reactivit ... | 1990 | 1703133 |
| mutational analysis of the dna polymerase and ribonuclease h activities of human immunodeficiency virus type 2 reverse transcriptase expressed in escherichia coli. | we have constructed a plasmid that, when introduced into escherichia coli, induces the synthesis of large quantities of a polypeptide with an apparent molecular weight of 68 kda. the hiv-2 reverse transcriptase (rt) made in e. coli is soluble in bacterial extracts and possesses both rna-dependent dna polymerase and ribonuclease h (rnase h) activities typical of retroviral rts. the hiv-2 rt expression clone was used to generate mutations in hiv-2 rt. there is a strong correlation between the effe ... | 1991 | 1701948 |
| potent and selective inhibition of human immunodeficiency virus type 1 (hiv-1) by 5-ethyl-6-phenylthiouracil derivatives through their interaction with the hiv-1 reverse transcriptase. | in the search for 1-[(2-hydroxyethoxy)-methyl]-6-(phenylthio)thymine (hept) derivatives, we have found several 5-ethyl-6-(phenylthio)uracil analogues to be highly potent and selective inhibitors of human immunodeficiency virus (hiv) type 1. 1-benzyloxymethyl-5-ethyl-6-phenylthiouracil, the most potent congener of the series, inhibits hiv-1 replication in a variety of cell systems, including peripheral blood lymphocytes, at a concentration of 1.5-7.0 nm, which is lower by a factor of 10(3) than t ... | 1991 | 1706522 |
| siv, stlv-i and type d retrovirus antibodies in captive rhesus macaques and immunoblot reactivity to siv p27 in human and rhesus monkey sera. | the prevalence of simian immunodeficiency virus (siv), simian t-cell lymphotropic virus type 1 (stlv-i), and type d retrovirus (srv-d) antibodies was determined for 1229 rhesus monkeys (macaca mulatta) from two research colonies. serum samples were tested by using enzyme-linked immunosorbent assay (elisa), immunoblot (ib), and radioimmunoprecipitation assay (ripa). seropositive results for the three retroviruses tested were 0 for siv, 270 (22%) for stlv-i, and 103 (8.4%) for type d retrovirus. o ... | 1990 | 1706606 |
| an antiviral target on reverse transcriptase of human immunodeficiency virus type 1 revealed by tetrahydroimidazo-[4,5,1-jk] [1,4]benzodiazepin-2 (1h)-one and -thione derivatives. | screening of pharmacologically acceptable prototype compounds has recently led to the discovery of a series of ultraselective inhibitors of human immunodeficiency virus (hiv)-1 replication, the tetrahydroimidazo[4,5,1-jk] [1,4]-benzodiazepin-2(1h)-one and -thione (tibo) derivatives. the tibo compounds completely suppress the formation of proviral dna in acutely infected cells, as revealed by polymerase chain reaction (pcr) analysis. tibo derivatives are inhibitory to the reverse transcriptase (r ... | 1991 | 1705038 |
| strain-specific neutralizing determinant in the transmembrane protein of simian immunodeficiency virus. | monoclonal antibody sf8/5e11, which recognizes the transmembrane protein (tmp) of simian immunodeficiency virus of macaque monkeys (sivmac), displayed strict strain specificity. it reacted with cloned and uncloned sivmac251 but not with cloned sivmac142 and sivmac239 on immunoblots. this monoclonal antibody neutralized infection by cloned, cell-free sivmac251 and inhibited formation of syncytia by cloned sivmac251-infected cells; these activities were specific to cloned sivmac251 and did not occ ... | 1991 | 1705994 |
| antiretroviral activity, biochemistry, and pharmacokinetics of 3'-azido-2',3'-dideoxy-5-methylcytidine. | 3'-azido-2',3'-dideoxy-5-methylcytidine (cs-92, azddmec) is an antiviral nucleoside analogue structurally related to 3'-azido-3'-deoxythymidine (azt). cs-92 is a potent and selective inhibitor of hiv-1 reverse transcriptase and hiv-1 replication in human lymphocytes and macrophages. the ec50 for cs-92 in hiv-1-infected human pbm cells was 0.09 microm. in hiv-1-infected human macrophages, the ec50 was 0.006 microm. this compound was also effective against human immunodeficiency virus type 2 in ly ... | 1990 | 1706574 |
| a capture enzyme immunoassay for detection of hiv-2/siv antigen. | an antigen capture enzyme immunoassay was developed for the demonstration of human immunodeficiency virus type 2 (hiv-2) and simian immunodeficiency virus (siv). the assay (hiv-2 ce) has a sensitivity of approximately 250 pg/ml of hiv-2/siv antigen. the hiv-2 ce was 4-16 times more sensitive than the abbott hiv-1 antigen assay for detection of hiv-2/siv antigen in cell culture supernatant. the sensitivity for detection of hiv-2/siv antigen in serum or plasma was 98.5% in the hiv-2 ce and 95.5% i ... | 1991 | 1706769 |
| monoclonal antibodies to conserved regions of the major core protein (gag24) of hiv-1 and hiv-2. | five mouse monoclonal antibodies were raised against a recombinant protein comprising the complete sequence of gag24 protein from htlv-iiib. all monoclonal antibodies recognized the native protein in enzyme-linked immunosorbant assay (elisa) and western blots. all monoclonal antibodies also cross-reacted with an human immunodeficiency virus type 2 (hiv-2) strain in western blots, whereas only one antibody detected hiv-2 p25 in elisa. by using synthetic peptides, cross-reacting epitopes were mapp ... | 1991 | 1707645 |
| inhibition of human immunodeficiency virus type 1 (hiv-1) replication by the dipyridodiazepinone bi-rg-587. | the dipyridodiazepinone human immunodeficiency virus type 1 (hiv-1)-specific reverse transcriptase (rt) inhibitor bi-rg-587 was tested for its ability to inhibit hiv-1 replication in both acutely and chronically infected cell lines. the ability of bi-rg-587 to inhibit steps in the virus replicative cycle other than reverse transcription was also assessed. bi-rg-587 was found to be a potent inhibitor of hiv-1 replication in acutely infected cells (50% inhibitory concentration [ic50] = 37.2 nm), a ... | 1991 | 1708400 |
| immune response to a major epitope of p24 during infection with human immunodeficiency virus type 1 and implications for diagnosis and prognosis. | a sequential inhibition enzyme-linked immunoassay (sieia) using a peroxidase-conjugated monoclonal antibody reacting to the sequence aaewdrvhp of p24hiv-1 (amino acids 209 to 217 of p55) was developed in order to detect and determine the titer of antibody to this epitope in various populations of human immunodeficiency virus type 1 (hiv-1)-positive patients. there was a good correlation between sieia and a commercially available competition assay that uses recombinant p24 protein and polyclonal ... | 1991 | 1709947 |
| in vitro efficacy of anti-hiv immunotoxins targeted by various antibodies to the envelope protein. | six different anti-hiv envelope antibodies and one irrelevant control antibody were coupled to ricin a chain and tested for their efficacy in inhibiting hiv tissue culture infections. the anti-hiv antibodies consisted of five monoclonals, three of murine and two of human origin, and one polyclonal preparation prepared by affinity purifying pooled serum antibodies from hiv-infected humans on rgp160. the binding specificity of the antibodies was defined by elisa by using recombinant envelope prote ... | 1991 | 1710247 |
| characterization of human antibody-binding sites on the external envelope of human immunodeficiency virus type 2. | antibody-reactive peptide scanning (pepscan) using overlapping nonapeptides and human sera as probes allows the identification of amino acids contributing significantly to antigen-antibody interaction. five-hundred and two overlapping nonapeptides derived from the human immunodeficiency virus type 2 strain rod (hiv-2rod) external envelope glycoprotein gp125 were synthesized to serve as probes for reactivity with eight sera of hiv-2-infected individuals. fifteen antibody-binding regions were iden ... | 1991 | 1710645 |
| dehydroandrographolide succinic acid monoester as an inhibitor against the human immunodeficiency virus. | dehydroandrographolide succinic acid monoester (dasm) is the dehydroandrographolyl ester of succinic acid; and andrographolide, from which dasm is made, is the major diterpenoid lactone found in the chinese medicinal herb, andrographis paniculata. dasm has been found to be an inhibitor against the human immunodeficiency virus (hiv) in vitro. it was nontoxic to the h9 cell at the concentrations of 50-200 (average, 108) micrograms/ml and was inhibitory to the hiv-1 (iiib) at the minimal concentrat ... | 1991 | 1708503 |
| bi-rg-587 is active against zidovudine-resistant human immunodeficiency virus type 1 and synergistic with zidovudine. | a series of dipyridodiazepinones have been shown to be potent inhibitors of human immunodeficiency virus type 1 (hiv-1) reverse transcriptase. the lead compound, bi-rg-587, had a 50% inhibitory concentration of 84 nm against hiv-1 reverse transcriptase activity. this compound reduced plaque formation of hiv-1 in hela cells expressing the cd4 receptor by 50% at 15 nm. bi-rg-587 at comparable concentrations inhibited the production of p24 antigen following the acute infection of cem t-lymphoblasto ... | 1991 | 1708976 |
| selective antiviral activity of synthetic soluble l-tyrosine and l-dopa melanins against human immunodeficiency virus in vitro. | melanins are pigments found in hair, skin, irides of the eye, and brain. their functions in mammals include protection from exposure to sunlight, camouflage from predators, sexual recognition within species, and possible electron transfer reactants. most natural melanins exist in an insoluble form, which is one reason there is little information on the biological properties of soluble melanins. here, synthetic soluble melanins were obtained by chemical oxidation of l-tyrosine or spontaneous oxid ... | 1991 | 1709802 |
| highly potent and selective inhibition of human immunodeficiency virus type 1 by a novel series of 6-substituted acyclouridine derivatives. | in the search for novel derivatives of 1-[2-(hydroxyethoxy)methyl]-6-(phenylthio)thymine (hept), we have found that several 5-ethyl-6-(3,5-dimethylphenylthio)uracil and 5-ethyl-6-(3,5-dimethylbenzyl)uracil analogues are exquisitely potent and selective inhibitors of human immunodeficiency virus type 1 (hiv-1) replication in a variety of cell culture systems. of this series, 5-ethyl-1-ethoxymethyl-6-(3,5-dimethylbenzyl)uracil (e-ebu-dm) emerged as the most active congener. its 50% inhibitory conc ... | 1991 | 1711148 |
| 9-[(2rs)-3-fluoro-2-phosphonylmethoxypropyl] derivatives of purines: a class of highly selective antiretroviral agents in vitro and in vivo. | a new class of compounds, 9-[(2rs)-3-fluoro-2-phosphonylmethoxypropyl] [(rs)-fpmp] derivatives of purines, is described that has selective activity against a broad spectrum of retroviruses [including human immunodeficiency virus type 1 (hiv-1) and type 2 (hiv-2)] but not other rna or dna viruses. this activity spectrum is completely different from that of the parental compounds, 9-[(2s)-3-hydroxy-2-phosphonylmethoxypropyl] [(s)-hpmp] derivatives of purines, which are active against a broad range ... | 1991 | 1711214 |
| comparison of linear antigenic sites in the envelope proteins of human immunodeficiency virus (hiv) type 2 and type 1. | the occurrence of dominant linear antigenic sites in the envelope glycoproteins of human immunodeficiency virus type 2 (hiv-2) was evaluated. twenty-five peptides representing different regions of hiv-2, strain sbl-6669, were synthesized. for comparison the corresponding peptides of hiv-1, strain bru, were also prepared. the peptides were tested in enzyme-linked immunosorbent assay (elisa) with human sera from individuals with proven hiv-1 or hiv-2 infection and simian sera from animals infected ... | 1991 | 1712215 |
| monoclonal antibodies define linear and conformational epitopes of hiv-1 pol gene products. | purified recombinant reverse transcriptase (rt) from human immunodeficiency virus type 1 (hiv-1) was used to raise 21 monoclonal antibodies with anti-rt specificities. the antibodies were characterized using western blotting against native virus and recognized either the p66 or p66, p51 components of rt. further immunoblotting using either cyanogen bromide fragmented rt or truncated mutants of rt along with cross-competition studies enabled the location of various immunogenic regions of rt to be ... | 1991 | 1712217 |
| oxathiin carboxanilide, a potent inhibitor of human immunodeficiency virus reproduction. | oxathiin carboxanilide (oc), nsc 615985, a compound originally synthesized as a potential fungicide, was demonstrated to be highly active in preventing human immunodeficiency virus (hiv)-induced cell killing and in inhibiting hiv reproduction. virus-infected cd4+ lymphocytes were completely protected by 0.5 microm oc, whereas no toxicity was observed at concentrations below 50 microm oc. production of infectious virus, viral p24 antigen, and virion reverse transcriptase were reduced by oc at con ... | 1991 | 1713689 |
| expression of the heterodimeric form of human immunodeficiency virus type 2 reverse transcriptase in escherichia coli and characterization of the enzyme. | a system for the expression of recombinant human immunodeficiency virus type 2 (hiv-2) reverse transcriptase (rt) in escherichia coli has been developed, which allows purification of the heterodimeric form of the enzyme as well as the separate purification of the two subunits. it is shown that equilibrium formation between monomeric and homodimeric forms of the recombinant 66- and 51-kda subunits is considerably more rapid than in the case of the corresponding homodimeric forms of hiv-1 rt. in a ... | 1991 | 1713589 |
| competition elisa using a human monoclonal antibody for detection of antibodies against human immunodeficiency virus type 1. | a novel competition elisa for detection of antibodies against hiv-1 was developed. the assay is based on competition at the single epitope level and utilises a human monoclonal antibody and an e. coli-produced fragment of the transmembrane glycoprotein gp41. the sensitivity of the assay was 100% in tests on 247 serum samples obtained from 219 individuals previously shown to be hiv-1 antibody positive by both conventional indirect elisa and the immunoblotting test. the patients represented variou ... | 1991 | 1712361 |
| localization of immunogenic domains in the human immunodeficiency virus type 2 envelope. | highly immunogenic domains have not yet been defined in the extracellular protein of the human immunodefiency virus type 2 (hiv-2) envelope. in this study, six contiguous segments covering the entire hiv-2st envelope were amplified and cloned into a bacterial expression vector to localize the relative immunogenic reactivity of different regions of the molecule by western blot (immunoblot) analysis. our results demonstrate that the extracellular protein of the hiv-2 envelope contains highly immun ... | 1991 | 1714524 |
| the vpx gene of simian immunodeficiency virus facilitates efficient viral replication in fresh lymphocytes and macrophage. | vpx is a unique open reading frame found in simian immunodeficiency virus (siv) and human immunodeficiency virus type 2 (hiv-2) but not in hiv-1. it encodes a 12- to 16-kda virion-associated protein. although vpx is dispensable for viral replication in several established human lymphocyte cell lines, there is no consensus regarding whether this gene is required for efficient viral replication in freshly isolated lymphocytes. we report here that the vpx mutant of sivmac exhibits different degrees ... | 1991 | 1714525 |
| characterization of murine monoclonal antibodies directed against the core proteins of human immunodeficiency virus types 1 and 2. | monoclonal antibodies (mabs) raised against the core proteins of human immunodeficiency virus type 1 (hiv-1; laboratory strain htlv-iiib) and hiv-2 (strain rod) were investigated in a variety of tests, e.g., enzyme-linked immunosorbent assay (elisa), immunostaining of western immunoblots, immunofluorescence, immunoprecipitation, and alkaline phosphatase anti-alkaline phosphatase assay. the mabs were grouped according to their cross-reactions. seven hiv-1-specific mabs reacted exclusively with hi ... | 1991 | 1712863 |
| several cd4 domains can play a role in human immunodeficiency virus infection in cells. | the human immunodefiency virus (hiv) uses the human cd4 glycoprotein as a receptor for infection of susceptible cells. cells expressing a series of mutated forms of the cd4 gene have shown a variability in their ability to support replication of three hiv type 1 (hiv-1) and three hiv-2 strains. moreover, when different stages of virus production were examined by a variety of assays, a consistent delay was observed in all cell lines containing cd4 mutants compared with those with intact full-leng ... | 1991 | 1714523 |
| characterization of monoclonal antibodies against the human immunodeficiency virus matrix protein, p17gag: identification of epitopes exposed at the surfaces of infected cells. | eight monoclonal antibodies reactive with the matrix protein of human immunodeficiency virus type 1 (hiv-1), p17gag, were isolated from rats which had been immunized with solubilized hiv-1 lysate. the epitope specificities of these antibodies were determined with a series of synthetic peptides representing overlapping regions of p17. six of the antibodies were mapped to three distinct regions of p17, while two antibodies (g11g1 and g11h3) reacted only with intact recombinant p17, suggesting that ... | 1991 | 1714518 |
| human immunodeficiency virus type 2 vpx protein augments viral infectivity. | the genomes of hiv and siv are complex and contain several accessory genes which modulate viral replication and pathogenicity. one of these genes, vpx, is unique to the hiv-2/siv group of viruses and encodes a virion-associated protein of unknown function. to examine the function of vpx, we constructed a vpx-deficient hiv-2 proviral clone and characterized its in vitro biological properties. following transfection into immortalized t-cell lines, vpx-mutant hiv-2 was fully replication competent a ... | 1991 | 1714662 |
| compatibility of rev gene activity in the four groups of primate lentiviruses. | the compatibility of rev genes derived from various primate immunodeficiency viruses of all distinct subgroups identified was assessed in three experimental systems: complementation experiments between proviral rev and gag mutants, evaluation of the ability of the rev gene products to activate proviral reporters, and examination of the capacity of various viruses to augment marker gene expression in the infected reporter cell lines. in all systems, human immunodeficiency virus type 1 (hiv-1) rev ... | 1991 | 1716025 |
| characterization of monoclonal antibodies identifying type and strain-specific epitopes of human immunodeficiency virus type 1. | several hybridoma cell lines were raised against the highly cytopathic zaïrian isolate of human immunodeficiency virus (hiv), hiv1-ndk. the specificity of the secreted monoclonal antibodies (mab) was demonstrated by immunoblotting, radioimmunoprecipitation and immunofluorescence. two hybridoma cell lines secreted mab reacting with independent epitopes of the ndk p17 capsid protein and its precursors. one, rl16.24.5, is specific for the ndk isolate whereas the other, rl16.45.1, along with anti-p2 ... | 1991 | 1715507 |
| nonnucleoside reverse transcriptase inhibitors that potently and specifically block human immunodeficiency virus type 1 replication. | certain bis(heteroaryl)piperazines (bhaps) are potent inhibitors of the human immunodeficiency virus type 1 (hiv-1) reverse transcriptase (rt) at concentrations lower by 2-4 orders of magnitude than that which inhibits normal cellular dna polymerase activity. combination of a bhap with nucleoside analog hiv-1 rt inhibitors suggested that together these compounds inhibited rt synergistically. in three human lymphocytic cell systems using several laboratory and clinical hiv-1 isolates, the bhaps b ... | 1991 | 1717988 |
| chimeric human immunodeficiency virus type 1/type 2 reverse transcriptases display reversed sensitivity to nonnucleoside analog inhibitors. | human immunodeficiency virus type 1 (hiv-1) reverse transcriptase (rt), an important therapeutic target in the treatment of aids, is effectively inhibited by a class of nonnucleoside analog compounds that includes nevirapine (bi-rg-587) and tetrahydroimidazo[4,5,1-jk]-[1,4]benzodiazepin-2(1h)-one and -thione. we show that both tyrosine residues at positions 181 and 188 flanking the putative catalytic site of hiv-1 rt are required for sensitivity of the enzyme to these compounds. hiv-2 rt, which ... | 1991 | 1719542 |
| human immunodeficiency virus can infect the apical and basolateral surfaces of human colonic epithelial cells. | the gastrointestinal tract is considered to be a major route of infection for the human immunodeficiency virus (hiv). to understand the interaction of hiv with epithelial cells of the intestinal mucosa, we have studied the infection of a human colon cancer cell clone ht-29-d4. the enterocyte-like differentiation of this clone can be modulated in vitro according to the concentration of glucose. we show that: (i) undifferentiated ht-29-d4 cells can be infected by hiv types 1 and 2 (hiv-1 and hiv-2 ... | 1991 | 1718004 |
| effect of evans blue and trypan blue on syncytia formation and infectivity of human immunodeficiency virus type i and type ii in vitro. | polyanionic compounds were used to inhibit infectivity of human immunodeficiency virus in vitro. suramin, evans blue, and trypan blue were shown to inhibit syncytia formation normally observed when hiv-1-infected cells are cocultured with cd4+ cells. the inhibition was more pronounced with evans blue than with any of the other polyanions studied. the inhibitory effect was significantly weaker in hiv-2 systems. however, the reverse transcriptase activities of both types of viruses were inhibited ... | 1991 | 1718343 |
| broadly neutralizing antibodies targeted to mucin-type carbohydrate epitopes of human immunodeficiency virus. | the cancer-related mucin-type carbohydrate neoantigen tn was found on gp160 and gp120 of human immunodeficiency virus (hiv). immunoglobulin g (igg) and igm monoclonal antibodies (mabs) against tn neutralized infection with cell-free virus and blocked fusion between hiv-infected and uninfected cells. this inhibition was found in infection of both lymphocytic cells and monocytoid cells. viruses tested included six hiv-1 and five hiv-2 isolates propagated in different cells, as well as infectious p ... | 1991 | 1719230 |
| antibody to reverse transcriptase of human retroviruses in multiple sclerosis. | htlv-1, hiv-1 and hiv-2 western blot analysis of sera from patients with multiple sclerosis (ms), from patients with other neurological diseases and from blood donors, revealed a rather frequent cross-reactivity with retroviral proteins in the ms group, though no patient was positive with the corresponding specific elisa serology. statistical analysis revealed a significant difference between the ms group and the two control groups for hiv-1 and hiv-2 reverse transcriptase fragments and for htlv ... | 1991 | 1724334 |
| isolation of hiv-1 from seropositive people living in cotonou, benin. | benin is located in west africa and is situated between hiv-2 and hiv-1-endemic zones. the first cases of hiv-1 infection in benin were reported in 1987. since then, aids cases have been diagnosed there and the number of known hiv-seropositive people has rapidly increased. blood samples were collected from 14 seropositive and 11 seronegative patients living in the main city, cotonou, and their peripheral blood mononuclear cells were cultured. in seven of the seropositive cases, a retrovirus was ... | 1990 | 1708264 |
| general principles of retrovirus immunodetection tests. | because infecting retroviruses contain protein and glycoprotein antigenic determinants that can be readily distinguished from host cell determinants, the development of immunologic detection systems, immunodetection tests, or immunoassays capable of identifying antigens of some retroviruses (oncoretroviruses) in blood, body fluids, or cells is possible. conversely, detection of antibodies produced by animals against some infecting retroviruses can also be used to identify current infections of l ... | 1991 | 1724772 |
| human immunodeficiency virus type 1 and type 2 protease monomers are functionally interchangeable in the dimeric enzymes. | human immunodeficiency virus type 1 (hiv-1) and hiv-2 proteases are dimers of identical subunits. we made a construct for the expression of recombinant one-chain hiv-2 protease dimer, which, like the previously described one-chain hiv-1 protease dimer, is fully active. the constructs for the one-chain dimers of hiv-1 and hiv-2 proteases were modified to produce hybrid one-chain dimers consisting of both hiv-1 and hiv-2 protease monomers. although the monomers share only 47.5% sequence identity, ... | 1992 | 1731102 |
| production and characterization of mouse monoclonal antibodies against the transmembrane protein of a human immunodeficiency virus type 2. | we established seven hybridoma clones producing monoclonal antibodies (mabs) against the envelope transmembrane protein (tmp) of a ghanian isolate of human immunodeficiency virus type 2 (hiv-2[gh-1]) from mice immunized with the detergent-disrupted purified whole virus. the mabs were found to react with 35 kilodalton (kd) tmp of the hiv-2[gh-1] virus in a western blot assay (wb). two of these mabs recognized 135 kd proteins in addition to tmp in the lysate of hiv-2[gh-1]-infected cells. two othe ... | 1991 | 1725959 |
| differential inhibitory effects of sulfated polysaccharides and polymers on the replication of various myxoviruses and retroviruses, depending on the composition of the target amino acid sequences of the viral envelope glycoproteins. | sulfated polysaccharides (i.e., dextran sulfate) and sulfated polymers (i.e., sulfated polyvinylalcohol and sulfated copolymers of acrylic acid with vinylalcohol) were found to be potent and selective inhibitors of the replication of respiratory syncytial virus (rsv) and influenza virus type a (influenza a virus) but not of other myxoviruses (parainfluenza 3, measles, and influenza b viruses). the compounds were also inhibitory to human immunodeficiency virus type 1 (hiv-1) and hiv-2 and simian ... | 1991 | 1725692 |