171 research outputs found

    Recent key advances in human immunodeficiency virus medicine and implications for China

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    In this article we summarize several recent major developments in human immunodeficiency virus treatment, prevention, outcome, and social policy change. Updated international guidelines endorse more aggressive treatment strategies and safer antiretroviral drugs. New antiretroviral options are being tested. Important lessons were learned in the areas of human immunodeficiency virus vaccines and microbicide gels from clinical studies, and additional trials in prevention, especially pre-exposure prophylaxis, are nearing completion. Insight into the role of the virus in the pathogenesis of diseases traditionally thought to be unrelated to acquired immunodeficiency syndrome has become a driving force for earlier and universal therapy. Lastly, we review important achievements of and future challenges facing China as she steps into her eighth year of the National Free Antiretroviral Treatment Program

    Massively parallel pyrosequencing-based transcriptome analyses of small brown planthopper (Laodelphax striatellus), a vector insect transmitting rice stripe virus (RSV)

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    <p>Abstract</p> <p>Background</p> <p>The small brown planthopper (<it>Laodelphax striatellus</it>) is an important agricultural pest that not only damages rice plants by sap-sucking, but also acts as a vector that transmits rice stripe virus (RSV), which can cause even more serious yield loss. Despite being a model organism for studying entomology, population biology, plant protection, molecular interactions among plants, viruses and insects, only a few genomic sequences are available for this species. To investigate its transcriptome and determine the differences between viruliferous and naïve <it>L. striatellus</it>, we employed 454-FLX high-throughput pyrosequencing to generate EST databases of this insect.</p> <p>Results</p> <p>We obtained 201,281 and 218,681 high-quality reads from viruliferous and naïve <it>L. striatellus</it>, respectively, with an average read length as 230 bp. These reads were assembled into contigs and two EST databases were generated. When all reads were combined, 16,885 contigs and 24,607 singletons (a total of 41,492 unigenes) were obtained, which represents a transcriptome of the insect. BlastX search against the NCBI-NR database revealed that only 6,873 (16.6%) of these unigenes have significant matches. Comparison of the distribution of GO classification among viruliferous, naïve, and combined EST databases indicated that these libraries are broadly representative of the <it>L. striatellus </it>transcriptomes. Functionally diverse transcripts from RSV, endosymbiotic bacteria <it>Wolbachia </it>and yeast-like symbiotes were identified, which reflects the possible lifestyles of these microbial symbionts that live in the cells of the host insect. Comparative genomic analysis revealed that <it>L. striatellus </it>encodes similar innate immunity regulatory systems as other insects, such as RNA interference, JAK/STAT and partial Imd cascades, which might be involved in defense against viral infection. In addition, we determined the differences in gene expression between vector and naïve samples, which generated a list of candidate genes that are potentially involved in the symbiosis of <it>L. striatellus </it>and RSV.</p> <p>Conclusions</p> <p>To our knowledge, the present study is the first description of a genomic project for <it>L. striatellus</it>. The identification of transcripts from RSV, <it>Wolbachia</it>, yeast-like symbiotes and genes abundantly expressed in viruliferous insect, provided a starting-point for investigating the molecular basis of symbiosis among these organisms.</p

    Quantifying the Impact of Reclaimed Asphalt Pavement on the Skid Resistance of Surface Mixtures

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    Pavement skid resistance is critical for public safety, especially in wet-weather conditions. In Texas, as the population grows and the likelihood of wet-surface crashes and fatalities increases, the use of Surface Aggregate Classification A (SAC-A) aggregate has significantly increased each year to improve pavement skid resistance. Texas Department of Transportation specifications allow for the use of reclaimed asphalt pavement (RAP) to conserve natural resources and save costs. However, the impact of RAP on the skid resistance of the surface mixture was unknown or not quantitatively studied. Currently, all RAPs are categorized as Surface Aggregate Classification B aggregate in Texas. This study proposed a method of quantitatively evaluating the skid resistance of RAP aggregate using a dynamic friction tester (DFT). The DFT test results (friction numbers) for RAP and raw aggregate were combined according to their gradations and stockpile percentages in the mixture design, called “blended-DFT,” to predict the skid resistance of the surface mixture. Twenty asphalt mixtures with different RAP types and percentages were designed and tested to study the impact of RAP on mixtures’ skid resistance. The researchers found that adding high skid-resistant RAP increases the mixture slab DFT values, while low skid-resistant RAP decreases the slab DFT values. This confirms the potential of using high skid-resistant RAP to conserve SAC-A raw aggregate resources. A preliminary DFT threshold for RAP to be rated as SAC-A aggregate was proposed in this study

    Recent key advances in human immunodeficiency virus medicine and implications for China

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    Abstract In this article we summarize several recent major developments in human immunodeficiency virus treatment, prevention, outcome, and social policy change. Updated international guidelines endorse more aggressive treatment strategies and safer antiretroviral drugs. New antiretroviral options are being tested. Important lessons were learned in the areas of human immunodeficiency virus vaccines and microbicide gels from clinical studies, and additional trials in prevention, especially pre-exposure prophylaxis, are nearing completion. Insight into the role of the virus in the pathogenesis of diseases traditionally thought to be unrelated to acquired immunodeficiency syndrome has become a driving force for earlier and universal therapy. Lastly, we review important achievements of and future challenges facing China as she steps into her eighth year of the National Free Antiretroviral Treatment Program

    0-6839: Designing Pavements to Support the Heavy Loads in the Energy Development Areas

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    0-6839In recent years, rapid energy development in Texas has caused significant damage to many farm-to-market (FM) roads, which traditionally have a thin asphalt surface layer plus a stabilized base directly over the subgrade. These roadways were often rehabilitated with full-depth reclamation (FDR), and often 2 to 3 percent cement was added to the pulverized existing materials. These roadways performed well under normal traffic loads but failed dramatically under the energy-sector truck loads. Figure 1 shows the damaged FM roads. The impact of overloading traffic on pavement damage is not only limited to FM roads; it also has significant influence on the pavement life of state highways and even interstate highways. There is an urgent need to repair many of these badly damaged roadways in all energy development areas

    Hepatitis B and Hepatitis C Seroprevalence in Children Receiving Antiretroviral Therapy for Human Immunodeficiency Virus-1 Infection in China, 2005–2009

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    Coinfection of hepatitis B virus (HBV) or hepatitis C virus (HCV) may compromise pediatric antiretroviral therapy (ART) in China. In this study, we evaluated the seroprevalence of HBV and HCV in children receiving ART and associated factors

    Risk Factors for SARS among Persons without Known Contact with SARS Patients, Beijing, China

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    Most cases of severe acute respiratory syndrome (SARS) have occurred in close contacts of SARS patients. However, in Beijing, a large proportion of SARS cases occurred in persons without such contact. We conducted a case-control study in Beijing that compared exposures of 94 unlinked, probable SARS patients with those of 281 community-based controls matched for age group and sex. Case-patients were more likely than controls to have chronic medical conditions or to have visited fever clinics (clinics at which possible SARS patients were separated from other patients), eaten outside the home, or taken taxis frequently. The use of masks was strongly protective. Among 31 case-patients for whom convalescent-phase (>21 days) sera were available, 26% had immunoglobulin G to SARS-associated coronavirus. Our finding that clinical SARS was associated with visits to fever clinics supports Beijing’s strategy of closing clinics with poor infection-control measures. Our finding that mask use lowered the risk for disease supports the community’s use of this strategy

    Failure to prescribe pneumocystis prophylaxis is associated with increased mortality, even in the cART era: results from the Treat Asia HIV observational database

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    <p>Abstract</p> <p>Background</p> <p>Pneumocystis jiroveci pneumonia (PCP) prophylaxis is recommended for patients with CD4 counts of less than 200 cells/mm<sup>3</sup>. This study examines the proportion of patients in the TREAT Asia HIV Observational Database (TAHOD) receiving PCP prophylaxis, and its effect on PCP and mortality.</p> <p>Methods</p> <p>TAHOD patients with prospective follow up had data extracted for prophylaxis using co-trimoxazole, dapsone or pentamidine. The proportion of patients on prophylaxis was calculated for each calendar year since 2003 among patients with CD4 counts of less than 200 cells/mm<sup>3</sup>. The effect of prophylaxis on PCP and survival were assessed using random-effect Poisson regression models.</p> <p>Results</p> <p>There were a total of 4050 patients on prospective follow up, and 90% of them were receiving combination antiretroviral therapy. Of those with CD4 counts of less than 200 cells/mm<sup>3</sup>, 58% to 72% in any given year received PCP prophylaxis, predominantly co-trimoxazole. During follow up, 62 patients developed PCP (0.5 per 100 person-years) and 169 died from all causes (1.36/100 person-years). After stratifying by site and adjusting for age, CD4 count, CDC stage and antiretroviral treatment, those without prophylaxis had no higher risk of PCP, but had a significantly higher risk of death (incident rate ratio 10.8, p < 0.001). PCP prophylaxis had greatest absolute benefit in patients with CD4 counts of less than 50 cells/mm<sup>3</sup>, lowering mortality rates from 33.5 to 6.3 per 100 person-years.</p> <p>Conclusions</p> <p>Approximately two-thirds of TAHOD patients with CD4 counts of less than 200 cells/mm<sup>3 </sup>received PCP prophylaxis. Patients without prophylaxis had significantly higher mortality, even in the era of combination ART. Although PCP may be under-diagnosed, these data suggest that prophylaxis is associated with important survival benefits.</p

    Loss to Followup in HIV-Infected Patients from Asia-Pacific Region: Results from TAHOD

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    This study examined characteristics of HIV-infected patients in the TREAT Asia HIV Observational Database who were lost to follow-up (LTFU) from treatment and care. Time from last clinic visit to 31 March 2009 was analysed to determine the interval that best classified LTFU. Patients defined as LTFU were then categorised into permanently LTFU (never returned) and temporary LTFU (re-entered later), and these groups compared. A total of 3626 patients were included (71% male). No clinic visits for 180 days was the best-performing LTFU definition (sensitivity 90.6%, specificity 92.3%). During 7697 person-years of follow-up, 1648 episodes of LFTU were recorded (21.4 per 100-person-years). Patients LFTU were younger (P = 0.002), had HIV viral load ≥500 copies/mL or missing (P = 0.021), had shorter history of HIV infection (P = 0.048), and received no, single- or double-antiretroviral therapy, or a triple-drug regimen containing a protease inhibitor (P < 0.001). 48% of patients LTFU never returned. These patients were more likely to have low or missing haemoglobin (P < 0.001), missing recent HIV viral load (P < 0.001), negative hepatitis C test (P = 0.025), and previous temporary LTFU episodes (P < 0.001). Our analyses suggest that patients not seen at a clinic for 180 days are at high risk of permanent LTFU, and should be aggressively traced
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