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Robert L Murphy

Publications and source records attributed to Robert L Murphy.

27 records · Page 2Linked to original sources
PubMed2003

Genetic and functional analysis of full-length human immunodeficiency virus type 1 env genes derived from brain and blood of patients with AIDS.

The genetic evolution of human immunodeficiency virus type 1 (HIV-1) in the brain is distinct from that in lymphoid tissues, indicating tissue-specific compartmentalization of the virus. Few primary HIV-1 envelope glycoproteins (Envs) from uncultured brain tissues have been biologically well characterized. In this study, we analyzed 37 full-length env genes from uncultured brain biopsy and blood samples from four patients with AIDS. Phylogenetic analysis of intrapatient sequence sets showed distinct clustering of brain relative to blood env sequences. However, no brain-specific signature sequence was identified. Furthermore, there was no significant difference in the number or positions of N-linked glycosylation sites between brain and blood env sequences. The patterns of coreceptor usage were heterogeneous, with no clear distinction between brain and blood env clones. Nine Envs used CCR5 as a coreceptor, one used CXCR4, and two used both CCR5 and CXCR4 in cell-to-cell fusion assays. Eight Envs could also use CCR3, CCR8, GPR15, STRL33, Apj, and/or GPR1, but these coreceptors did not play a major role in virus entry into microglia. Recognition of epitopes by the 2F5, T30, AG10H9, F105, 17b, and C11 monoclonal antibodies varied among env clones, reflecting genetic and conformational heterogeneity. Envs from two patients contained 28 to 32 N-glycosylation sites in gp120, compared to around 25 in lab strains and well-characterized primary isolates. These results suggest that HIV-1 Envs in brain cannot be distinguished from those in blood on the basis of coreceptor usage or the number or positions of N-glycosylation sites, indicating that other properties underlie neurotropism. The study also demonstrates characteristics of primary HIV-1 Envs from uncultured tissues and implies that Env variants that are glycosylated more extensively than lab strains and well-characterized primary isolates should be considered during development of vaccines and neutralizing antibodies.

Acquired Immunodeficiency Syndrome↗
PubMed2002

Persistent abnormalities in lymphoid tissues of human immunodeficiency virus-infected patients successfully treated with highly active antiretroviral therapy.

Effective highly active antiretroviral therapy (HAART) for human immunodeficiency virus type 1 is associated with virus suppression and immune reconstitution. However, in some patients, this reconstitution is partial or incomplete because CD4(+) cell counts do not increase significantly. This may be due to damage in the microenvironment of lymphoid tissues (LTs), where CD4(+) T cells reside. To test this hypothesis, LT samples were obtained from 23 patients enrolled in a prospective trial that compared 3 different HAART regimens. Analysis of LT architecture and CD4(+) T cells populations revealed abnormalities in 100% of the LT samples, especially in the follicles, with 43% showing absence, 14% showing regression, and 43% showing hyperplasia. CD4(+) T cell populations were abnormal in 16 (89%) of 18 tissue samples, with 7 (39%) of 18 decreased by >50% of normal levels. These data are consistent with the hypothesis that persistent abnormalities in the microenvironment can influence immune reconstitution and document persistent LT abnormalities with HAART not detected by measures of peripheral CD4(+) T cell count.

Adult↗
PubMed2002

Influence of filgrastim (granulocyte colony-stimulating factor) on human immunodeficiency virus type 1 RNA in patients with cytomegalovirus retinitis.

Filgrastim, or granulocyte colony-stimulating factor, reverses neutropenia associated with human immunodeficiency virus type 1 (HIV-1) and cytomegalovirus (CMV) infections. During a trial of anti-CMV retinitis therapies coadministered with antiretroviral therapy, 2-4 plasma specimens of HIV-1 RNA were collected from 36 HIV-1-infected patients receiving filgrastim to prevent neutropenia and from 36 patients not receiving filgrastim. For both groups, the crude mean and mean rate of change of HIV-1 log(10) RNA levels were similar. Adjustment for covariates (CD4(+) T cell lymphocytes, virus load at enrollment, level of neutropenia and antiretroviral therapy [mainly non-highly active antiretroviral therapy], and anti-CMV therapy during follow-up) resulted in a mean log(10) HIV-1 RNA level for individuals receiving filgrastim versus those not receiving the drug of 5.11 versus 4.87 (P=.12) and respective log mean rates of change per month of -0.08 versus -0.21 (P=.08). This latter difference has borderline statistical significance, which suggests that filgrastim may reduce the decline of HIV-1 RNA loads.

AIDS-Related Opportunistic Infections↗
PubMed2002

The safety, plasma pharmacokinetics, and antiviral activity of subcutaneous enfuvirtide (T-20), a peptide inhibitor of gp41-mediated virus fusion, in HIV-infected adults.

Enfuvirtide (T-20) is a novel antiretroviral agent that blocks HIV-1 cell fusion. A 28-day randomized dose-comparison study was conducted to determine the safety, pharmacokinetics, and antiviral activity of enfuvirtide in 78 HIV-infected adults, most with extensive treatment experience. Patients received enfuvirtide, added to a failing regimen, either by continuous subcutaneous infusion (CSI: 12.5, 25, 50 or 100 mg/day) or by subcutaneous (SC) injection (50 or 100 mg twice daily). Dose-related decreases in viral load were observed, with a maximum mean reduction from baseline of 1.6 log(10) copies/ml (p< 0.001) seen in the 100 mg bid SC group. Most responses diminished by 28 days. Plasma pharmacokinetics and antiviral responses were more consistent for SC injection than for CSI because of technical difficulties experienced with CSI. Injection site reactions were common but generally mild. These results indicate that enfuvirtide is a promising new therapeutic agent for HIV-infected patients, including those with prior antiretroviral treatment.

Acquired Immunodeficiency Syndrome↗
PubMed2002

The pharmacokinetics of amprenavir, zidovudine, and lamivudine in the genital tracts of men infected with human immunodeficiency virus type 1 (AIDS clinical trials group study 850).

The AIDS Clinical Trials Group Study 850 (ACTG 850) evaluated the penetration of zidovudine (ZDV), lamivudine (3TC), and amprenavir (APV), given alone and in combination with the 2 nucleoside analogues, into the male genital tract, because these factors may affect human immunodeficiency virus (HIV) type 1 suppression and transmission. Nineteen men receiving APV monotherapy and 12 men receiving triple therapy donated blood plasma (BP) and seminal plasma (SP) during therapy. Paired SP and BP were used to calculate compartmental concentration ratios. APV SP concentrations were consistently lower than BP concentrations, ZDV SP concentrations approximated BP concentrations early but became greater later in the dosing interval, and 3TC SP concentrations were substantially greater than BP concentrations throughout. Observed SP concentrations plotted with population BP concentration-time curves confirmed these findings, suggesting that passive diffusion (APV), slowed elimination (ZDV), and either active accumulation and/or inhibition of elimination (3TC) are responsible for SP concentrations of these agents. The antiretroviral effect of APV monotherapy was related to APV concentrations.

Adult↗
PubMed2002

Safety and antiviral activity at 48 weeks of lopinavir/ritonavir plus nevirapine and 2 nucleoside reverse-transcriptase inhibitors in human immunodeficiency virus type 1-infected protease inhibitor-experienced patients.

The safety and antiviral activity of lopinavir (Lpv), a protease inhibitor (PI) coformulated with ritonavir (Rtv) to enhance its pharmacokinetic properties, were evaluated in 70 patients with plasma human immunodeficiency virus type 1 (HIV-1) RNA levels of 1000-100,000 copies/mL on a first PI-containing regimen. Patients were randomized to substitute only the PI with Lpv/Rtv, 400/100 mg or 400/200 mg twice daily. On day 15, nevirapine (200 mg 2x/day) was added, and nucleoside reverse-transcriptase inhibitors were changed. Despite a >4-fold reduction in phenotypic susceptibility to the preentry PI in 63% of patients, mean plasma HIV-1 RNA levels declined by 1.14 log(10) copies/mL after 2 weeks of Lpv/Rtv. At week 48, 86% of subjects receiving treatment had plasma HIV-1 RNA levels of <400 copies/mL; 76% had levels <50 HIV-1 RNA copies/mL (intent-to-treat: 70% and 60%, respectively). Mean CD4 cell counts increased by 125 cells/muL. Three patients discontinued therapy for drug-related adverse events.

Adult↗
PubMed2002

Characteristics of patients with cytomegalovirus retinitis in the era of highly active antiretroviral therapy.

PURPOSE: To describe the characteristics of patients with AIDS and cytomegalovirus retinitis in the era of highly active antiretroviral therapy (HAART). METHODS: Prospective cohort study. Baseline (enrollment) data were compared between patients with newly diagnosed cytomegalovirus retinitis (incident cases) and those with previously diagnosed cytomegalovirus retinitis (prevalent cases). RESULTS: As of December 31, 2000, 45 incident and 200 prevalent cases had been enrolled. Among prevalent cases, the median time from cytomegalovirus retinitis diagnosis was 2.9 years. Incident cases were more likely than prevalent cases to be women (35.4% vs 15.3%, P =.001), African American (45.4% vs 20.4%, P =.002), and uninsured (29.6% vs 7.6%, P <.001). Incident cases were less likely than prevalent cases to be on HAART (51.2% vs 77.6%, P =.001) and to have had an immunologic response to HAART (increase in CD4(+) T-cell count to > 100 cells/microl) (12.2% vs 57.5%, P <.001). The median CD4(+) T-cell count at enrollment among incident cases was 17 cells/microl and among prevalent cases was 159 cells/microl (P <.001). Immune recovery uveitis had been diagnosed in 15.5% of the prevalent cases. Sixty-three percent of prevalent cases were not on anticytomegalovirus therapy. CONCLUSIONS: There is a population of patients with previously diagnosed and longstanding cytomegalovirus retinitis who have experienced immune recovery as a consequence of HAART and are no longer receiving anticytomegalovirus therapy. There are demographic differences between incident and prevalent cases that may reflect the evolution of the AIDS epidemic and differences in utilization of health care services.

AIDS-Related Opportunistic Infections↗
PubMed2002

The AIDS autopsy spleen: a comparison of the pre-anti-retroviral and highly active anti-retroviral therapy eras.

Pathologic findings attributed to human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS) are described in the spleen in studies that encompassed the years preceding highly active anti-retroviral therapy (HAART). Major findings included white-pulp depletion, hemosiderin deposition, spindle cell proliferations, and perivascular hyalinization. Infectious and malignant infiltrates were commonly noted and characterized. The histopathology of AIDS autopsy spleens since the introduction of protease inhibitors has not been studied. Histologic sections from 168 cases of AIDS spleens examined at autopsy over a 19-year period (1982-2000) were evaluated for significant pathologic findings. Multiple morphologic parameters were recorded, including a graded estimation of white-pulp depletion. Significantly less white-pulp depletion was observed in the 39 HAART-era spleens (1995-2000) compared with the 129 spleens from the 1982-1994 patient group (P =.001). The rates of splenic involvement by atypical mycobacteria and cytomegalovirus were similar to those in the past, although the overall clinical rates of these opportunistic infections were found to be decreased. The annual numbers of AIDS autopsies have decreased, reflecting a nationwide trend of lower autopsy rates. Increased survival with HIV infection and AIDS is now apparent. Protease inhibitors, in conjunction with other contemporary therapies, may have contributed to the preservation of white pulp observed in the HAART patient group.

Acquired Immunodeficiency Syndrome↗