ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectivesThe characterization and localization of HIV-1 Nef highly expressed in permanently infected astrocytes (TH4–7-5) as a model for latent infection of human brain cells.DesignImmunochemical methods are an appropriate tool to investigate expression and localization of cellular proteins.MethodsNef expression was analysed by Western blot and immunoperoxidase staining using a panel of monoclonal and polyclonal antibodies. Cellular localization studies were performed by indirect immunofluorescence and subcellular fractionation of TH4–7-5 cells. Myristoylation of Nef was investigated by immunoprecipitation of [3H]myristic acid-labelled cell extract. TH4–7-5 nef gene was cloned and amplified by polymerase chain reaction and the nef nucleotide sequence analysed.ResultsReactivities of various Nef-specific antibodies with Nef antigen in TH4–7-5 cells were demonstrated by Western blot analysis. Immunofluorescence revealed cytoplasmic perinuclear staining of Nef with most antibodies. However, one monoclonal antibody against amino acids 168–175 of Nef showed intense homogeneous nuclear staining in TH4–7-5 cells. Reactivity of this Nef antibody was blocked with recombinant Nef derived from TH4–7-5 cells. After subcellular fractionation, Nef was detected in nuclear, membrane and cytosolic fractions of TH4–7-5 cells. No myristoylated Nef antigen was detectable, perhaps because of a serine residue at position 2 of the TH4–7-5 nef gene instead of the glycine residue required for myristoylation.ConclusionsChronically HIV-1-infected astrocytoma cells with restricted virus production express different antigenic forms of Nef, which can be distinguished by their subcellular localization. Variant subcellular targeting of Nef suggests the existence of multiple activities of Nef within HIV-infected cells.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo determine whether human adrenal cells can be infected by HIV.MethodsCultured human fetal adrenal cells and the SW13 human adrenocortical carcinoma cell line were inoculated with several HIV-1 and HIV-2 strains. Virus replication was detected by viral core antigen enzyme-linked immunosorbent and reverse transcriptase assays. CD4 expression was measured by Northern blot and polymerase chain reaction procedures.ResultsHIV infection of these adrenal cells was detected and was most evident after cocultivation of the inoculated cells with peripheral blood mononuclear cells. Infection does not involve the CD4 molecule, which is not expressed by these adrenal cells. The relative level of HIV replication depended on the viral strain used. Virus production occurred best in cells that maintained evidence of adrenal cell function. Infection did not appear to disturb steroidogenesis measured in the cells.ConclusionsThese observations indicate that human adrenal cells are susceptible to HIV infection, and provide further evidence of the polytropic nature of the virus.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo compare biological properties of zidovudine-resistant variants of HIV-1 isolated from subjects on long-term drug therapy with drug-sensitive parental isolates obtained from the same patients before initiation of treatment.MethodsClinical HIV-1 strains were isolated following co-incubation of patient peripheral blood mononuclear cells with mitogen-stimulated umbilical cord blood lymphocytes. Drug resistance was evaluated by infecting MT-4 cells pretreated with zidovudine and maintained under drug pressure.ResultsThe drug-resistant phenotype remained stable, following many viral replication cycles in the absence of zidovudine. Drug-resistant variants contained fewer replication-competent viruses but were more cytopathogenic than their corresponding zidovudine-sensitive parental strains.ConclusionsThese results suggest that drug-resistant strains possess biological properties that may differ from those of drug-sensitive variants of HIV-1.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo map epitopes on gp120 defined by human antibodies and to examine the neutralizing activity of these antibodies.Design and methodsSerum from HIV-1-antibody-positive individuals was used to screen a random fragment expression library representing gp120 from the HIVIIIBclone BH10. The library was based on the pUEX1 expression vector. Serum was tested for in vitro neutralizing activity using H9 cells and the HIVIIIBisolate.ResultsFour different epitopes defined by human antibodies were mapped on gp120. Two of these have not previously been reported and are located within amino acids (aa) 90–100 in the C1 region and aa 355–365 in the semi-conserved region between V3 and V4. The other two are located within aa 140–145 and aa 286–309. These epitopes are situated in regions that have been shown to demarcate human epitopes. Three serum samples with neutralization titres ≤1024 were identified. None of the purified antibody fractions defining the mapped epitopes on gp120 had any neutralizing capacity against HIVIIIB.ConclusionsThis study is the first demonstration of the applicability of random fragment expression libraries for the direct screening of human serum in order to map epitopes on gp120. Two new epitopes and two previously identified epitopes were mapped in this way. However, none of the linear epitopes was defined by antibody fractions neutralizing HIIIB, and it was not possible to map epitopes defined by neutralizing antibodies in the serum samples capable of neutralizing HIIIBinfection of H9 cells. Thus, it appears that the neutralizing activity of serum in this study was not due to anti-gp120 antibodies defining linear epitopes.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo study the safety of intravenously administered porcine-derived hyperimmune immunoglobulin to HIV-1, PASSHIV-1, in humans.MethodsFourteen HIV-1-infected individuals were treated for 5–7 days with intravenous infusions of highly purified PASSHIV-1 (<95% pure). Two of the 14 patients were retreated 3 months later with PASSHIV-1 for an additional 5 days to evaluate side-effects from retreatment with porcine immunoglobulins.ResultsTen of the patients had no side-effects from PASSHIV-1 therapy. Three patients experienced transient urticarial eruptions, which responded to antihistamine administration and did not require discontinuation of therapy. One patient, who received concomitant administration of human gammaglobulin, experienced serum sickness (type 3 hypersensitivity reaction). All patients demonstrated a significant improvement in fatigue (100% response), weight (all those with previous weight loss gained weight), fever (100% response), polyneuropathy (100% response), bronchitis (100% response), candidiasis (100% response), diarrhea (100% response), and dermatitis (100% response). One out of the five patients with Kaposi's sarcoma demonstrated >50% improvement. Mean CD4+ cell counts in the group rose from 143 ±263 to 234 ±323 × 106/1 4–6 months following completion of therapy (P= 0.013, paired Student's t-test); CD4+ counts rose > twofold in six individuals. P24antigen, present in four patients, was negative following therapy in all patients. Other laboratory parameters that responded to therapy included: platelet counts (71% response), leukopenia (57% response), elevated lactic dehydrogenase (100% response), and elevated alkaline phosphatase (100% response). PASSHIV-1 was well tolerated by HIV-1-infected individuals.ConclusionThis therapy appears to be efficacious in ameliorating some of the clinical aspects and symptoms of HIV-1 infection.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo evaluate the humoral response to routine childhood immunization of HIV-infected children.DesignResponse rate, antibody titres and persistence after polio and tetanus vaccination were compared in 72 children with HIV seropositivity at birth and divided according to HIV infection status as determined by clinical and laboratory tests.MethodsPolio antibodies were titred in a microneutralization test (positive titres, ≥1:4), and antibody to tetanus toxoid with a passive haemagglutination method (protective titres, ≥1:1024).ResultsThe response rates to polio and tetanus vaccination (>80 and >75%) were similar in the HIV-infected and non-infected children, as were antibody levels. In the subgroup with sera obtained some months after the last dose of vaccine, polio antibody levels decreased in all four HIV-infected and in three of the seven non-infected children; protective tetanus antitoxin levels were detected in three of the six infected and in all three non-infected children.ConclusionsThis study demonstrates the ability of children with HIV infection to respond adequately to the two vaccines considered, although tetanus antitoxin levels were inferior, compared with those in the seroreverted children. The unsatisfactory antibody levels observed in the admittedly few HIV-positive children studied some months after the last vaccination could be the result of a lower initial protective level and not necessarily an expression of severely impaired immunocompetence. The administration of booster doses in addition to the traditional immunization schedule could be useful in children with HIV infection.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo determine the safety and pharmacokinetics of the nucleoside analogue,3TC.DesignA Phase I, open-label, single-centre study.MethodsTwenty asymptomatic, HIV-infected male patients with CD4 lymphocyte counts <500 × 106/l who had not received previous antiretroviral therapy completed the study. Each patient received a single intravenous dose followed by a single oral dose of 3TC. Four patients were dosed at each of five dose levels (0.25, 1.0, 2.0, 4.0 and 8.0 mg/kg).ResultsThe most commonly reported adverse event was headache, which was generally reported to be mild. The mean bioavailability of 3TC was 82% following oral administration. The majority of the dose (approximately 70%) was excreted unchanged in the urine.ConclusionsOverall, 3TC was well tolerated following dosing, and there were no significant changes in the safety parameters measured. Phase l/ll clinical trials with 3TC are ongoing to evaluate its safety, pharmacokinetics and preliminary activity.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectiveTo determine the maximum tolerated dose of granulocyte-macrophage colony-stimulating factor (CM-CSF) that would reduce the severity and duration of neutropenia from combination cytotoxic chemotherapy in the treatment of AIDS-related Kaposi's sarcoma (KS).DesignPhase I, dose escalation.SettingOutpatient clinic of a university hospital.PatientsHIV-seropositive patients with advanced KS.InterventionsCombination chemotherapy consisting of adriamycin, bleomycin, and vincristine (ABV), with escalating doses of recombinant human GM-CSF (rhGM-CSF). Patients were treated for a median of six cycles (range, between two and seven cycles) of biweekly chemotherapy with GM-CSF administered in divided daily subcutaneous doses on days 2–12. Serum cytokine levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α were measured before, during, and after therapy to correlate with response to therapy.ResultsA GM-CSF dose of 250 μg/m2was well tolerated, whereas the next dose escalation, of 500μg/m2, was associated with dose-limiting toxicities, including grade 3 fever, fatigue, and diarrhea. GM-CSF produced predictable cyclic increases in granulocytes, allowing for delivery of full-dose chemotherapy on schedule. All patients were HIV-p24-antigen-negative at study entry; no activation of p24 antigenemia was observed after repeat testing. Consistent changes in cytokine levels were not observed. Responses included one complete and three partial responses, and two patients with stable disease parameters.ConclusionsWe conclude that GM-CSF can be administered safely to patients with AIDS-related KS receiving myelosuppressive chemotherapy, resulting in granulocytic response, without up-regulation of HIV p24 antigen levels in serum.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

ObjectivesTo evaluate efficacy and tolerance of bleomycin in AIDS-associated mucocutaneous Kaposi's sarcoma. A previous study showed that bleomycin was effective and well tolerated in this setting.DesignA non-comparative, open, prospective study.MethodsSeventy patients were treated with 5 mg per day intramuscular bleomycin on 3 consecutive days every 2 weeks.ResultsTwo patients achieved a complete response and 50 a partial response (overall response rate, 74%). Median time to treatment response was 4 weeks (range, 2–12 weeks) and median time to relapse 10 weeks (range, 2–36 weeks). Dose-limiting toxicity consisted of cutaneous adverse reactions.ConclusionBleomycin is active against AIDS-associated mucocutaneous Kaposi's sarcoma; relapse occurs after discontinuation of therapy.

ISSN:0269-9370    

出版商:OVID    

年代:1992

数据来源: OVID