摘要:

Background:Plasma HIV-1 RNA levels are high in vertically infected infants. Information in older children is limited, particularly in those who have not received antiretroviral therapy.Objectives:To describe the relationships between HIV-1 RNA, age and CD4 cell count in untreated vertically infected children.Design:HIV-1 RNA was measured in 70 children [median age, 3.5 years (range, 0.4–11.9 years); median CD4 cell count, 881 × 106/l (interquartile range, 576–1347 × 106cells/l)] enrolled in a randomized placebo-controlled trial comparing immediate with deferred zidovudine in asymptomatic or mildly symptomatic vertically infected children (PENTA-1 trial). Short-term variability was assessed by comparing HIV-1 RNA at −2 and 0 weeks (prior to randomization). The relationship between age and HIV-1 RNA, and CD4 cell count was analysed using data from all children prior to randomization and sequential samples from 35 remaining on placebo for up to 105 weeks, by fitting mixed linear models.Results:The within-individual SD in viral load was 0.26 log10copies/ml. The median plasma HIV-1 RNA at enrolment was 4.61 log10(range, 2.3–6.56 log10copies/ml), significantly higher in children aged ≤ 2 years (median, 5.23 log10copies/ml) than in those aged > 2 years (4.51 log10copies/ml;P< 0.0001). Mean HIV-1 RNA fell by 0.38 log10copies/ml per year up to 2 years of age, by 0.21 log10copies/ml per year from 2 to 4 years of age, and by 0.03 log10copies/ml per year from 4 to 6 years of age reaching a nadir of 4.25 log10copies/ml at 6 years. Mean log10CD4 cell count declined steadily with age and was not significantly correlated with HIV-1 RNA, although there was some evidence that the rate of log10CD4 cell decline was negatively correlated with the initial rate of HIV-1 RNA decline. No mutations associated with resistance to zidovudine were observed.Conclusions:Age is a key factor in the interpretation of both viral load and CD4 cell count in vertically infected children.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objectives:This study examines the cytotoxicity potential and the mechanism of toxicity of the HIV-1 gp120 on human neuroblastoma cells.Design:Previous data from our group have suggested that the HIV-1 envelope protein gp120 promotes the secretion of tumor necrosis factor-α and other factors by astrocytes and microglial cells present in primary human brain cell cultures, thereby contributing to the injury of neurons in these cultures. This study investigates the cytotoxicity potential and the mechanism of toxicity of gp120 on human neuroblastoma cells.Methods:SK-N-SH cells were treated with HIV-1 gp120, and was followed byin situDNA fragmentation staining and small molecular weight DNA extraction studies to ascertain the induction of apoptosis by gp120 in these cells. To evaluate a potential role of the growth suppressor gene p53, gp120-treated SK-N-SH cells were subjected to reverse transcription polymerase chain reaction (RT-PCR) and Western blot analyses for the induction of p53. An antisense oligodeoxynucleotide against p53 was used to investigate the role of p53 in the gp120-induced apoptosis in these cells.Results:Data from T7 DNA polymerase staining and small molecular weight DNA extraction studies demonstrated that gp120-induced DNA breakage in SK-N-SH cells with fragmentation patterns characteristic of apoptosis. RT-PCR and Western blot analyses revealed that the gp120-mediated induction of apoptosis was dependent on a gp120-induced and gp120-sustained upregulation of p53. The induction of p53 by gp120 was specific, since an antibody against gp120 prevented both the induction of p53 and subsequent apoptosis in SK-N-SH cells. The critical role of p53 was further illustrated by the effectiveness of a p53 antisense oligodeoxynucleotide to inhibit the gp120-induced apoptosis. As a control, the apoptosis-inducing potential of gp120 on SK-N-SH cells was not seen in the HIV-1 Gag proteins even when used at up to 5 nM.Conclusions:These results established that HIV-1 gp120 is potentially cytotoxic to human neuronal cells through the induction of p53, which may eventually lead to induction of apoptosis.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objective:Concentrations of quinolinic acid, anN-methyl-D-aspartate agonist, are often elevated for long periods of time in the cerebrospinal fluid (CSF) and brain tissue of patients with AIDS dementia complex (ADC). This study was designed to test the hypothesis that chronic exposure of human neurons to quinolinic acid levels equivalent to those in the CSF of ADC patients is neurotoxic.Design and methods:Human fetal brain 14–16 weeks post-menses was cultured in medium with no detectable levels of quinolinic acid. After 4 weeks, 350 or 1200 nmol/l quinolinic acid was added to the feeding medium for a further 5 weeks. Neurotoxicity was evaluated using immunohistochemistry, transmission and scanning electron microscopy, and image analysis.Results:A total of 1200 nmol/l quinolinic acid caused altered cell associations, a decrease in cell density and decreased microtubule-associated protein (MAP)-2 immunoreactivity compared with cultures exposed to 350 nmol/l quinolinic acid or controls. Image analysis of neurons in randomly selected fields revealed significantly swollen cells (P< 0.0001) compared with those treated with 350 nmol/l quinolinic acid or controls. Dendritic varicosities and discontinuous microtubular arrays were present in neurons exposed to both quinolinic acid concentrations, but not in control cultures.Conclusions:This study is the first to assess quinolinic acid levels in the experimental medium, and demonstrates that chronic exposure of human neurons to concentrations of quinolinic acid equivalent to those in the CSF of patients with ADC leads to alterations in dendritic ultrastructure and MAP-2 immunoreactivity, which is consistent with ADC pathology.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objective:Human cytomegalovirus (HCMV) is often isolated from HIV-1-infected patients and the two viruses can infect the same cell type giving rise to direct bidirectional interactions. Whereas the long terminal repeat (LTR) transactivation ability of HCMV immediate early gene (IE1/IE2) is well documented, no information is available on the possible role of other HCMV proteins. In this study, the activity of ppUL44, an early DNA-binding protein, on HIV LTR transactivation was investigated.Methods:HIV LTR transactivation by ppUL44 in presence or absence of HIV-1 Tat and HCMV IE1/IE2 was determined in J-Jhan and U973 cells through transient transfection experiments with a series of different expression vectors. Some experiments were also performed on U373-MG astrocytoma cells permanently transfected with UL44 or with another HCMV gene used as a control (UL55).Results:The basal transactivation activity of the HIV LTR was not influenced by the presence of ppUL44. On the contrary, the transactivation observed in the presence of Tat, IE1/IE2 or both factors in synergy was strongly downregulated by ppUL44 in a dose-dependent manner. Deletion constructs of ppUL44 demonstrated that the region of the molecule responsible for the inhibition of the LTR is located within the last 114 amino acids at the carboxyl-terminal region.Conclusions:The results obtained indicate that within the last 114 amino acids of ppUL44 there is a domain that has a negative effect on the ability of HIV-1 LTR to be activated by both its autologous transactivator Tat and the heterologous transactivator HCMV IE1/IE2 functioning individually or synergistically.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objectives:To determine the ability of neutrophils isolated from HIV-seropositive patients to produce proinflammatory cytokines.Design:Thein vitroresponsiveness of polymorphonuclear neutrophils (PMN) and peripheral blood mononuclear cells (PBMC) to lipopolysaccharide (LPS), used in the presence or absence of interferon (IFN)-γ, was determined in 47 HIV-positive patients with advanced stages of virus infection.Methods:Cytokines in cell-free supernatants were measured by enzyme-linked immunosorbent assay or radioimmunoassay.Results:Cell-free supernatants from PMN isolated from the peripheral blood of HIV-positive patients and stimulated with LPS contained increased amounts of tumour necrosis factor (TNF)-α and interleukin (IL)-8 with respect to supernatants obtained from PMN of normal donors. In contrast, release of IL-1β and IL-1ra (IL-1 receptor antagonist) in response to LPS, or LPS plus IFN-γ, was found to be lower in PMN from HIV-positive patients than in PMN from controls, but was significant only in the case of IL-1ra. Furthermore, the release of IL-12 induced by LPS or LPS plus IFN-γ did not significantly differ between PMN from HIV-positive patients and healthy donors. Concerning PBMC, the production of TNF-α and IL-12 in response to LPS, or LPS plus IFN-γ, was found to be significantly higher in cells isolated from HIV-positive patients, whereas the release of IL-1β was significantly lower. In the case of IL-8, no statistically significant difference was found between PBMC isolated from HIV-positive patients and healthy donors.Conclusions:Collectively, the data suggest that in HIV-positive patients with advanced stages of disease, the ability of PMN to produce specific cytokines in response to LPS is significantly altered. Alterations in this ability might contribute to the evolution of HIV disease.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objective:To study the influence of hepatitis C virus (HCV) co-infection on clinical and immunological evolution of HIV-infected patients.Design:A longitudinal study of HIV-infected individuals with or without HCV infection, identified at the Infectious Diseases Department of Dijon University Hospital and enrolled in a historical cohort, was performed.Methods:One hundred and nineteen HIV-infected people co-infected with HCV and 119 matched individuals infected with HIV alone were included in the cohort (median participation time 3 years; range, 2 months to 11.5 years). Clinical progression was defined as one or more of the following: a 30% decrease in the Karnofsky index; a 20% loss of body weight; an AIDS-defining illness (for non-AIDS patients); death (except by accident, suicide or overdose). Immunological progression was defined as a 50% decrease in the initial CD4 T-cell count (for patients with an initial count > 100 × 106cells/l). Effects of HCV co-infection were evaluated using Kaplan-Meier survival analysis and significance was tested using univariate (log-rank and Peto's tests) and multivariate methods (Cox's model).Results:In univariate analysis, immunological progression was not statistically different between the HCV-positive group and the HCV-negative group, whereas clinical progression was significantly faster in HCV-positive patients (P< 0.005, log–rank test). In a multivariate Cox model, clinical progression remained significantly associated with infection by HCV [hazard ratio (HR), 1.64; 95% confidence interval (CI), 1.06–2.55;P< 0.05]. Stratified multivariable analysis retained HCV as a significant prognostic factor of clinical progression (HR, 10.9; 95% CI, 1.09–109.3;P< 0.05) and immunological progression (HR, 2.31; 95% CI, 1.16–4.62;P< 0.02) for patients with an initial CD4 count above 600 × 106cells/l.Conclusions:Clinical progression is more rapid in HIV–HCV co-infected patients than in HIV-seropositive patients are not infected by HCV. The prognostic value of HCV infection for both clinical and immunological progression is significant at early stages of HIV infection. These findings may argue for active management of hepatitis C infection in co-infected individuals, especially for asymptomatic patients whose CD4 count is above 600 × 106cells/l, to predict and prevent accelerated progression of HCV and HIV diseases.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objective:Neuropathological abnormalities induced by HIV-1 are not always predictable on the basis of the presence of HIV-related neurological symptoms. HIV-1 RNA load was measured in the cerebrospinal fluid (CSF) of HIV-infected patients to verify whether it could be a marker of HIV-induced neuropathology.Design and methods:Histopathological and immunohistochemical examination of the brain for HIV-1 p24 antigen was performed in 50 HIV-infected patients with neurological symptoms; patients were defined as having HIV encephalitis in the presence of HIV-related lesions or HIV-1 p24 antigen-positive cells. Quantitative polymerase chain reaction for HIV-1 RNA was retrospectively applied to CSF samples that had been drawn 1–60 days prior to death from these 50 patients; paired plasma samples of 28 patients were also analysed.Results:The CSF HIV-1 RNA copy numbers were significantly higher in 22 patients with HIV encephalitis than in 28 patients without (median, 4.77 log10versus 3.45 log10copies/ml;P= 0.0003). No correlation was found between CSF HIV-1 RNA load and the presence of opportunistic brain pathologies at post-mortem examination or between HIV-1 RNA loads in paired CSF and plasma samples.Conclusions:High CSF HIV-1 RNA levels are associated with HIV encephalitis, regardless of the presence of opportunistic brain diseases or HIV-1 RNA levels in plasma. Quantitative CSF HIV-1 RNA may therefore be used as a specific marker of HIV-induced neuropathology.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objective:To investigate the different responses to antiretroviral treatment including zidovudine, of patients harbouring HIV with primary resistance to zidovudine, serum viral load, and CD4+ cell counts, for 24 weeks in a group of antiretroviral-naive patients with the codon 215 mutation of the HIVpolgene and in a control group at the start of treatment.Design:A case–control retrospective study (1989–1996).Method:Nineteen out of 210 patients previously studied harboured the codon 215 mutation, had a self-reported compliance with treatment, a minimum follow-up of 24 weeks, and were treated with zidovudine alone or in combination with other nucleoside analogues. These patients were matched with 19 patients with wild-type strains at entry by initial CD4+ cell counts, clinical status, and antiretroviral treatment.Results:During the first 12 weeks, CD4+ cell counts increased (76 ± 26 and 64 ± 26 × 106/l in wild-type and mutant virus-infected groups, respectively), decreasing slightly until week 24, although no significant differences were found between the two groups studied. Serum viral load decreased in both groups (change in serum viral load of 0.80 ± 0.11 log10and 0.87 ± 0.26 log10copies/ml, wild-type and mutant virus-infected, respectively), although no significant differences were found between groups.Conclusion:No significant differences were found between patients with the primary mutation to zidovudine and control patients harbouring wild-type virus in terms of short-term response measured by serum viral load and CD4+ cell counts.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Objective:To determine the safety and efficacy of the sulphated polysaccharide, dextrin 2-sulphate, when delivered to the lymphatic circulation by the peritoneal route.Design:An open Phase I/II dose-escalation clinical study in which six patients with AIDS were treated with seven courses of dextrin 2-sulphate each lasting 1 month.Methods:During each course of treatment, the drug was administered daily for 28 days using an intraperitoneal catheter. Viral load was measured at frequent intervals using a plasma tissue culture infectious dose (TCID) assay, a cellular TCID assay, p24 antigenaemia, HIV-1 RNA and HIV-1 DNA. Plasma β-chemokine levels were also measured.Results:Dose escalation was completed without toxicity. A total of 7 patient-months of treatment were completed. With increasing doses of dextrin 2-sulphate, the infectious plasma viraemia, cellular viraemia and p24 antigenaemia all fell during the period of drug administration, but with no significant change in HIV-1 RNA. This was associated with increased plasma levels of macrophage inflammatory protein (MIP)-1α and MIP-1β. Dextrin 2-sulphate accumulated in peritoneal macrophages and induced the release of MIP-1α and MIP-1β from these cellsin vitro. These β-chemokines could have augmented the cell surface-mediated anti-HIV-1 effect of dextrin 2-sulphatein vivoby binding to and blocking the CC-chemokine receptor-5. A second fall in infectious plasma viraemia, cellular viraemia, p24 antigenaemia and HIV-1 RNA was seen at day 100 which was then sustained for several months. A clinical improvement in Kaposi's sarcoma was also seen.Conclusions:Our results suggest that the intraperitoneal administration of dextrin 2-sulphate can reduce the replication of HIV-1 in patients with AIDS. With increasing doses of dextrin 2-sulphate, the fall in viral load was seen during the period of drug administration and again 2 months after completing treatment.

ISSN:0269-9370    

出版商:OVID    

年代:1998

数据来源: OVID