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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

There is growing literature on the subject of aneurysmal degeneration of arteries in patients who are infected with HIV. A patient recently seen at our medical center with an aneurysm of the carotid artery stimulated our interest in reviewing the mechanisms by which HIV may initiate or predispose to these pathologies. There are at least three major possibilities: (1) immunodeficiency allows bacteria that are known to cause mycotic aneurysms to proliferate without immune restraint; (2) one or more of the HIV envelope proteins sufficiently resemble one or more artery-specific-antigenic proteins (ASAPs) that may trigger an autoimmune response (molecular mimicry); and (3) the HIV virus itself infects arterial-resident cells that maintain the integrity of the load-bearing matrix. The computational searches reported here suggest that the ASAP, matrix cell adhesion molecule-1 (Mat-CAM-1), has a high degree of similarity to known ligands for HIV envelope proteins gp41 and gp120. No similarities of Mat-CAM-1 to the HIV envelope glycoproteins were detected. Accordingly, among the possibilities for explaining the HIV/aneurysm connection, direct infection of aortic fibroblasts by the HIV virus is more likely to be the pathogenetic mechanism than the process of molecular mimicry.
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PMID:Arterial aneurysms in HIV patients: molecular mimicry versus direct infection? 1718 60

Human monoclonal antibodies (hmAbs) that neutralize HIV isolates from different clades at physiologically relevant concentrations (broadly cross-reactive neutralizing antibodies (bcnAbs)) are rare in infected individuals. Only small number of such antibodies have been identified and extensively characterized, but efforts to elicit them in vivo have not been successful. We have recently developed novel approaches, based on sequential (SAP) and competitive (CAP) antigen panning methodologies, and the use of antigens with increased exposure of conserved epitopes, for enhanced identification of bcnAbs to gp120-gp41. Some of the antibodies identified by using these approaches (X5, m6, m9) bind better to gp120-CD4 complexes than to gp120 alone (CD4i antibodies); they exhibit exceptional neutralizing activity and breadth of neutralization as scFvs and on average lower potency as Fabs and IgGs. Other antibodies that compete with CD4 for binding to gp120 (m14, m18) (CD4bs antibodies) are weaker neutralizers but also exhibit broad neutralizing activity although at relatively high concentrations. The anti-gp41 antibodies (m43, m44, m45, m47 and m48) appear to have broad cross-reactivity and bind to a new group of conserved conformational epitopes distinct from those of the bcnAbs 4E10, 2F5 and Z13. Recently, the crystal structures of X5, m14 and m18 have been solved and compared to those of 17b and b12; they all contain long H3s that play a major role in their mechanism of binding. The H3s of X5, m6 and m9, unlike the others known, appear to be very flexible which may be related to the mechanism of their exceptional neutralizing activity. The further characterization of the molecular interactions of the bcnAbs with gp120-gp41 will undoubtedly help in our understanding of the mechanisms of virus neutralization, and in the design of entry inhibitors and vaccines.
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PMID:Novel approaches for identification of broadly cross-reactive HIV-1 neutralizing human monoclonal antibodies and improvement of their potency. 1726 28

A human cervical explant culture was utilized for the preclinical assessment of anti-human immunodeficiency virus type 1 (HIV-1) activity and tissue toxicity of formulated, candidate topical microbicides. Products tested included cellulose acetate 1,2-benzene dicarboxylate (CAP), a carrageenan-based product (PC-515), a naphthalene sulfonate polymer (PRO 2000), a lysine dendrimer (SPL7013), a nonnucleoside reverse transcriptase inhibitor (UC781), and an antimicrobial peptide (D2A21), along with their placebos. Cervical explants were cultured overnight with HIV-1 with or without product, washed, and monitored for signs of HIV-1 infection. HIV-1 infection was determined by p24gag levels in the basolateral medium and by immunohistochemical analysis of the explant. Product toxicity was measured by the MTT [1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan] assay and histology. CAP, PRO 2000, SPL7013, and UC781 consistently prevented HIV-1 infection in all explants tested. PC-515 and D2A21 prevented HIV-1 infection in 50% or fewer of the explants tested. Placebos did not prevent infection in any of the explants tested. With the exception of PRO 2000 (4%), the MTT assay and histological analysis of the other products and placebos showed minimal toxicity to the epithelium and submucosa. Collectively, these data suggest that this culture system can be used for evaluating the safety and efficacy of topical microbicides designed for vaginal use.
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PMID:Preclinical testing of candidate topical microbicides for anti-human immunodeficiency virus type 1 activity and tissue toxicity in a human cervical explant culture. 1735 37

Topical microbicides (cellulose acetate 1,2 benzene dicarboxylate [CAP], PRO 2000, SPL7013, and UC781) are being investigated to reduce the sexual transmission of human immunodeficiency virus type 1 (HIV-1). These products were shown to prevent the transfer of infectious HIV-1 from urogenital and colorectal epithelial cell lines to peripheral blood mononuclear cells. However, it was unclear if the topical microbicides rendered the virus noninfectious and/or reduced the binding to the epithelial cells. To test this, epithelial cells were cultured with HIV-1 in the presence or absence of topical microbicides or their placebos. The cells were washed, RNA lysates were made, and real-time PCR was performed for HIV-1. PRO 2000 and SPL7013 significantly (P < 0.0001) reduced the amount of bound HIV-1 to the colorectal epithelial cell line across clades A, B, C, and CRF01-AE. While none of the products reduced the binding of HIV-1 clades A and C to the urogenital cell line, CAP, PRO 2000, and SPL7013 significantly (P </= 0.002) reduced the binding of clades B and CRF01-AE. In general, PRO 2000 and SPL7013 placebos significantly (P < 0.0001) reduced the amount of bound HIV-1 but were less than the active products. UC781, its placebo, and hydroxyethyl cellulose (placebo for CAP) minimally affected the amount of bound HIV-1. These results suggest that rendering HIV-1 noninfectious may not correlate to the amount of HIV-1 bound to epithelial cells and possible shedding into mucosal secretions. Therefore, functional virological assays in addition to measuring viral RNA should be included when clinically evaluating topical microbicide use by infected persons.
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PMID:Effect of topical microbicides on infectious human immunodeficiency virus type 1 binding to epithelial cells. 1740 8

The COBAS AmpliPrep/COBAS AMPLICOR HIV-1 MONITOR Test, version 1.5 (CAP/CA), and the COBAS AMPLICOR HIV-1 MONITOR Test, version 1.5, were compared. CAP/CA reduced and consolidated labor while modestly increasing assay throughput without increased failure rates or direct costs, regardless of batch size and assay format.
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PMID:Impact of the COBAS AmpliPrep/COBAS AMPLICOR HIV-1 MONITOR Test, Version 1.5, on clinical laboratory operations. 1763 8

In the present study, 277 clinical samples from untreated and treated HIV-1-infected patients with different clades were used to assess the agreement between the COBAS AmpliPrep/COBAS TaqMan HIV-1 test (CAP/CTM) and VERSANT HIV-1 RNA 3.0 Assay (bDNA). A qualitative comparison of the results of the two assays showed concordance for 255 positive and 15 negative samples (94.95%, kappa = 0.798). However, seven samples with viral loads close to the lower limit of detection for CAP/CTM were negative by bDNA. A significant correlation (r = 0.881, p < 0.001) was observed for 253 samples with viral loads within the dynamic ranges of the two assays, and Bland-Altman analysis showed good agreement (96.05%) between the two assays for these 253 samples [mean (+/-2 SD), 0.389(-0.385, 1.163)]. Furthermore, ART drugs had no impact on the performances of the two assays. For samples with different clades predominant in China, the fitted regression line differed significantly from the line of equality, although significant correlations (r = 0.850-0.891, p < 0.001) and good agreements (92.86-97.25%) were found for the two assays. The mean differences for clade B' and BC samples were significant (p < 0.01). Good precision for clade B' samples was achieved for the CAP/CTM (CV: 20.73%) and bDNA (CV: 12.19%) assays. Furthermore, for clades B', BC, and AE, both assays exhibited good linearities (r = 0.9773-0.9998). Thus, the CAP/CTM and bDNA assays could be useful for quantifying HIV-1 RNA in routine clinical samples and monitoring viral loads in treated and untreated HIV-infected patients in China.
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PMID:Comparative evaluation of the COBAS AmpliPrep/COBAS TaqMan HIV type 1 test (CAP/CTM) and VERSANT HIV type 1 RNA 3.0 assay (bDNA) for quantifying HIV type 1 viral loads in China. 1892 95

Cellulose acetate phthalate (CAP, cellulose acetate 1,2-benzenedicarboxylate) is a common polymeric oral tablet coating. CAP is also a vaginal microbicide candidate that potently inhibits HIV-1 proliferation. This paper describes the development of a precise, stability-indicating gel permeation chromatography (GPC) assay for CAP. During accelerated stability studies monitored by separate reversed-phase high performance liquid chromatography (RP-HPLC) and GPC analyses, an apparent loss of mass balance was observed. This deficit was corrected by recalculating the response factor (RF) for each degraded sample, proportional to the fraction of phthalate remaining bound to the polymeric CAP. The correction factor enabled CAP and the degradation product phthalic acid (PA) to be quantitated by a single GPC analysis. The chromatographic approach taken here could potentially apply to any polymer containing degradable chromophores.
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PMID:Development of a gel permeation chromatographic assay to achieve mass balance in cellulose acetate phthalate stability studies. 1907 Sep 84

Abstract While infection with HIV-1 has become a pandemic, the presence of HIV-2 is also of concern in certain regions of the world. We have characterized the gp105 region of the envelope gene of HIV-2 isolates from Western India. Phylogenetic analysis of all 18 sequences revealed that these sequences were closely related to each other as well as to published African and European HIV-2 group A sequences, with an overall genetic divergence of 10.9% (range 2-14%). Our study sequences showed close relatedness with West African HIV-2 group A (CAM group) sequences from Guinea Bissau with 89% homology. This was further confirmed by SimPlot as well as RIP analysis. Accordingly, the sequences presented here demonstrate the predominance of HIV-2 group A infection and show no evidence of HIV-2 recombination in Western India.
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PMID:Molecular phylogenetics of nearly full-length HIV type 2 envelope gene sequences from West India. 1918 24

The Abbott RealTime human immunodeficiency virus type 1 (HIV-1) assay (ART) and the Cobas AmpliPrep/Cobas TaqMan HIV-1 test (CTM) are commercially available assays for quantification of HIV-1 RNA in plasma. We evaluated performance characteristics, workflow, throughput, reliability, and direct costs of these assays. Both assays yielded good correlation of quantitative results (r = 0.95) among clinical specimens, with a mean difference of -0.34 log(10) copies/ml. Testing of healthy donor plasma specimens yielded "target not detected" results by ART, with "HIV-1 RNA detected, <40 copies/ml" results for 3.3% (3 of 90 samples) of these specimens by CTM. Both the m2000sp/m2000rt (ART) and docked CAP/CTM96 (CTM) instrument systems were capable of operating with continuous, uninterrupted workflow. When daily maintenance and cleaning were included, ART and CTM run durations (5 h 52 min and 6 h 4 min, respectively) and hands-on times (53 min and 46 min, respectively) were similar for a run batch size of 24. While ART was more flexible in terms of run batch size, CTM required fewer user interventions and consistently produced higher specimen throughput rates at 8, 16, and 24 h. Assay run failure rates were 6.3% (1 of 16 runs) and 4.2% (1 of 24 runs) for ART and CTM, respectively (P = 1.000), with invalid specimen result rates of 1.0% (5 of 495 specimens) and 2.8% (11 of 399 specimens), respectively (P = 0.073). Direct reagent and consumable costs for each assay were comparable (difference of <10%). In selecting an assay for implementation, laboratories should consider how various assay and instrument features might impact laboratory operation and patient care.
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PMID:Comparison of the Abbott realtime human immunodeficiency virus type 1 (HIV-1) assay to the Cobas AmpliPrep/Cobas TaqMan HIV-1 test: workflow, reliability, and direct costs. 1919 37

The semen plasma virus load is measured to ensure the safety of sperm processing during medically assisted procreation (MAP) for couples with a human immunodeficiency virus type 1 (HIV-1)-infected man. A practical, automated protocol using the COBAS Ampliprep CAP/CTM kit in the COBAS TaqMan96 system was developed to measure the HIV-1 load in semen plasma samples. HIV-1 was detected in 13.4% of the semen samples processed at our MAP center. Of the eight patients having a detectable semen HIV-1 load, five had no detectable virus in their blood plasma. This highlights the residual risk of HIV-1 transmission during unprotected intercourse and raises the question of the possible consequences of ineffective highly active antiretroviral therapy in the genital tract.
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PMID:Determining seminal plasma human immunodeficiency virus type 1 load in the context of efficient highly active antiretroviral therapy. 1964 Oct 60


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