63 research outputs found

    HIV-1 Envelope Subregion Length Variation during Disease Progression

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    The V3 loop of the HIV-1 Env protein is the primary determinant of viral coreceptor usage, whereas the V1V2 loop region is thought to influence coreceptor binding and participate in shielding of neutralization-sensitive regions of the Env glycoprotein gp120 from antibody responses. The functional properties and antigenicity of V1V2 are influenced by changes in amino acid sequence, sequence length and patterns of N-linked glycosylation. However, how these polymorphisms relate to HIV pathogenesis is not fully understood. We examined 5185 HIV-1 gp120 nucleotide sequence fragments and clinical data from 154 individuals (152 were infected with HIV-1 Subtype B). Sequences were aligned, translated, manually edited and separated into V1V2, C2, V3, C3, V4, C4 and V5 subregions. V1-V5 and subregion lengths were calculated, and potential N-linked glycosylation sites (PNLGS) counted. Loop lengths and PNLGS were examined as a function of time since infection, CD4 count, viral load, and calendar year in cross-sectional and longitudinal analyses. V1V2 length and PNLGS increased significantly through chronic infection before declining in late-stage infection. In cross-sectional analyses, V1V2 length also increased by calendar year between 1984 and 2004 in subjects with early and mid-stage illness. Our observations suggest that there is little selection for loop length at the time of transmission; following infection, HIV-1 adapts to host immune responses through increased V1V2 length and/or addition of carbohydrate moieties at N-linked glycosylation sites. V1V2 shortening during early and late-stage infection may reflect ineffective host immunity. Transmission from donors with chronic illness may have caused the modest increase in V1V2 length observed during the course of the pandemic

    Characterization of a new simian immunodeficiency virus strain in a naturally infected Pan troglodytes troglodytes chimpanzee with AIDS related symptoms

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    <p>Abstract</p> <p>Background</p> <p>Data on the evolution of natural SIV infection in chimpanzees (SIVcpz) and on the impact of SIV on local ape populations are only available for Eastern African chimpanzee subspecies (<it>Pan troglodytes schweinfurthii</it>), and no data exist for Central chimpanzees (<it>Pan troglodytes troglodytes</it>), the natural reservoir of the ancestors of HIV-1 in humans. Here, we report a case of naturally-acquired SIVcpz infection in a <it>P.t.troglodytes </it>chimpanzee with clinical and biological data and analysis of viral evolution over the course of infection.</p> <p>Results</p> <p>A male chimpanzee (Cam155), 1.5 years, was seized in southern Cameroon in November 2003 and screened SIV positive during quarantine. Clinical follow-up and biological analyses have been performed for 7 years and showed a significant decline of CD4 counts (1,380 cells/mm<sup>3 </sup>in 2004 vs 287 in 2009), a severe thrombocytopenia (130,000 cells/mm<sup>3 </sup>in 2004 vs 5,000 cells/mm<sup>3 </sup>in 2009), a weight loss of 21.8% from August 2009 to January 2010 (16 to 12.5 kg) and frequent periods of infections with diverse pathogens.</p> <p>DNA from PBMC, leftover from clinical follow-up samples collected in 2004 and 2009, was used to amplify overlapping fragments and sequence two full-length SIVcpz<it>Ptt</it>-Cam155 genomes. SIVcpz<it>Ptt</it>-Cam155 was phylogenetically related to other SIVcpz<it>Ptt </it>from Cameroon (SIVcpz<it>Ptt</it>-Cam13) and Gabon (SIVcpz<it>Ptt</it>-Gab1). Ten molecular clones 5 years apart, spanning the V1V4 gp120 <it>env </it>region (1,100 bp), were obtained. Analyses of the <it>env </it>region showed positive selection (dN-dS >0), intra-host length variation and extensive amino acid diversity between clones, greater in 2009. Over 5 years, N-glycosylation site frequency significantly increased (p < 0.0001).</p> <p>Conclusions</p> <p>Here, we describe for the first time the clinical history and viral evolution of a naturally SIV infected <it>P.t.troglodytes </it>chimpanzee. The findings show an increasing viral diversity over time and suggest clinical progression to an AIDS-like disease, showing that SIVcpz can be pathogenic in its host, as previously described in <it>P.t.schweinfurthii</it>. Although studying the impact of SIV infection in wild apes is difficult, efforts should be made to better characterize the pathogenicity of the ancestors of HIV-1 in their natural host and to find out whether SIV infection also plays a role in ape population decline.</p

    The concordance of the limiting antigen and the Bio-Rad avidity assays in persons from Estonia infected mainly with HIV-1 CRF06_cpx

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    BACKGROUND: Serological assays to determine HIV incidence have contributed to estimates of HIV incidence, monitoring of HIV spread, and evaluation of prevention strategies. Two frequently used incidence assays are the Sedia HIV-1 LAg-Avidity EIA (LAg) and the Bio-Rad avidity incidence (BRAI) assays with a mean duration of recent infection (MDRI) of 130 and 240 days for subtype B infections, respectively. Little is known about how these assays perform with recombinant HIV-1 strains. We evaluated the concordance of these assays in a population infected mainly with HIV-1 CRF06_cpx. MATERIAL/METHODS: Remnant serum samples (n = 288) collected from confirmed, newly-diagnosed HIV-positive persons from Estonia in 2013 were tested. Demographic and clinical data were extracted from clinical databases. LAg was performed according to the manufacturer’s protocol and BRAI testing was done using a validated protocol. Samples with LAg-pending or BRAI-invalid results were reclassified as recent if they were from persons with viral loads <1000 copies/mL or were reclassified as long-term if presenting with AIDS. RESULTS: In total 325 new HIV infections were diagnosed in 2013 in Estonia. Of those 276 persons were tested with both LAg and BRAI. Using assay results only, the recency rate was 44% and 70% by LAg and BRAI, respectively. The majority of samples (92%) recent by LAg were recent by BRAI. Similarly, 89% of samples long-term by BRAI were long-term by LAg. After clinical information was included in the analysis, the recency rate was 44% and 62% for LAg and BRAI, respectively. The majority of samples (86%) recent by LAg were recent by BRAI and 91% of long-term infections by BRAI were long-term by LAg. CONCLUSIONS: Comparison of LAg and BRAI results in this mostly CRF06_cpx-infected population showed good concordance for incidence classification. Our finding of a higher recency rate with BRAI in this population is likely related to the longer MDRI for this assay

    Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

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    BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

    Comparison Among Clark’s, Breslow’s, and TNM Classifications for Cutaneous Head and Neck Malignant Melanoma

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    This retrospective study was carried out to assess the prognostic value of three classification systems used for staging cutaneous head and neck malig- nant melanoma (CHNME). Fifty-three patients with histologically proven CHNME were analyzed. Thirty patients were never treated before admis- sion, whereas 23 (43.4%) had a second radical re- section of the primary tumor location, 9 (17%) had neck nodes, none had distant metastasis, and all had a minimum of 5 years of follow-up. Results show that T-stage is the most important clinical prognostic parameter, whereas Clark’s and Breslow’s classifications have lower impact in defining prog- nosis. Sites of primary tumor determines different clinical outcomes, but this does not reach statistically significant values. A second surgery on the primary tumor location is possible and is effective toward survival. No statistical differences were noted be- tween the previously untreated and treated groups. Neck nodes have to be removed with neck dissection, and this regimen can improve the clinical outcome; however, only 40% of neck positive patients survive more than 5 years

    Comparison Among Clark's, Breslow's, and TNM Classifications for Cutaneous Head and Neck Malignant Melanoma.

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    This retrospective study was carried out to assess the prognostic value of three classification systems used for staging cutaneous head and neck malignant melanoma (CHNME). Fifty-three patients with histologically proven CHNME were analyzed. Thirty patients were never treated before admission, whereas 23 (43.4\%) had a second radical resection of the primary tumor location, 9 (17\%) had neck nodes, none had distant metastasis, and all had a minimum of 5 years of follow-up. Results show that T-stage is the most important clinical prognostic parameter, whereas Clark's and Breslow's classifications have lower impact in defining prognosis. Sites of primary tumor determines different clinical outcomes, but this does not reach statistically significant values. A second surgery on the primary tumor location is possible and is effective toward survival. No statistical differences were noted between the previously untreated and treated groups. Neck nodes have to be removed with neck dissection, and this regimen can improve the clinical outcome; however, only 40\% of neck positive patients survive more than 5 years

    Comparison Among Clark\u2019s, Breslow\u2019s, and TNM Classifications for Cutaneous Head and Neck Malignant Melanoma

    No full text
    This retrospective study was carried out to assess the prognostic value of three classification systems used for staging cutaneous head and neck malig- nant melanoma (CHNME). Fifty-three patients with histologically proven CHNME were analyzed. Thirty patients were never treated before admis- sion, whereas 23 (43.4%) had a second radical re- section of the primary tumor location, 9 (17%) had neck nodes, none had distant metastasis, and all had a minimum of 5 years of follow-up. Results show that T-stage is the most important clinical prognostic parameter, whereas Clark\u2019s and Breslow\u2019s classifications have lower impact in defining prog- nosis. Sites of primary tumor determines different clinical outcomes, but this does not reach statistically significant values. A second surgery on the primary tumor location is possible and is effective toward survival. No statistical differences were noted be- tween the previously untreated and treated groups. Neck nodes have to be removed with neck dissection, and this regimen can improve the clinical outcome; however, only 40% of neck positive patients survive more than 5 years
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