152 research outputs found

    Antiviral drug-resistant HBV: Standardization of nomenclature and assays and recommendations for management

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    Substantial advances have been made in the treatment of chronic hepatitis B in the past decade. Approved treatments for chronic hepatitis B include 2 formulations of interferon and 4 nucleos(t)ide analogues (NAs). Sustained viral suppression is rarely achieved after withdrawal of a 48-week course of NA therapy, necessitating long, and in many cases, indefinite treatment with increasing risk of development of drug resistance. Antiviral resistance and poor adherence are the most important factors in treatment failure of hepatitis B. Thus, there is a need to standardize nomenclature relating to hepatitis B antiviral resistance, and to define genotypic, phenotypic, and clinical resistance to NA therapy. (H EPATOLOGY 2007;46:254–265.)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56065/1/21698_ftp.pd

    Assessment of HBV flare in a randomized clinical trial in HIV/HBV coinfected subjects initiating HBV-active antiretroviral therapy in Thailand

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    BACKGROUND: Hepatic Flare (HF) after initiation of highly active antiretroviral therapy (HAART) in HIV-HBV coinfected individuals is well recognized but prospective data on predictors and subsequent outcome are limited. METHODS: The Tenofovir in HIV-HBV coinfection study was a randomized clinical trial of HBV-active HAART including lamivudine and/or tenofovir in antiretroviral naïve HIV-HBV individuals in Thailand. RESULTS: Early HF (EHF) was defined as ALT > 5 × ULN during the first 12 weeks. EHF was observed in 8 (22%) of individuals at a median of 56 days. 6/8 EHF cases were asymptomatic and resolved with HAART continuation, however one subject with underlying cirrhosis died following rapid hepatic decompensation. EHF was significantly associated with higher baseline ALT (79 IU/L vs 36 IU/L non-EHF, p = 0.008) and HBV DNA (9.9 log10 c/ml vs 8.4 log10 c/ml non EHF, p = 0.009), and subsequent serological change. HBeAg loss occurred in 75% of EHF cases versus 22% in non-EHF (p = 0.04), and HBsAg loss in 25% of EHF cases versus 4% of non-EHF (p = 0.053). CONCLUSION: EHF after HBV active HAART initiation was frequently observed in this population. Timing of EHF, association with elevated ALT and HBV DNA and high rate of seroconversion are all consistent with immune restoration as the likely underlying process. CLINICAL TRIAL NUMBER: NCT00192595

    Deep seafloor arrivals : an unexplained set of arrivals in long-range ocean acoustic propagation

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    Author Posting. © Acoustical Society of America, 2009. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 126 (2009): 599-606, doi:10.1121/1.3158826.Receptions, from a ship-suspended source (in the band 50–100 Hz) to an ocean bottom seismometer (about 5000 m depth) and the deepest element on a vertical hydrophone array (about 750 m above the seafloor) that were acquired on the 2004 Long-Range Ocean Acoustic Propagation Experiment in the North Pacific Ocean, are described. The ranges varied from 50 to 3200 km. In addition to predicted ocean acoustic arrivals and deep shadow zone arrivals (leaking below turning points), “deep seafloor arrivals,” that are dominant on the seafloor geophone but are absent or very weak on the hydrophone array, are observed. These deep seafloor arrivals are an unexplained set of arrivals in ocean acoustics possibly associated with seafloor interface waves.The LOAPEX source deployments, the moored DVLA receiver deployments, and some post-cruise data reduction and analysis were funded by the Office of Naval Research under Award Nos. N00014-1403-1-0181, N00014-03-1-0182, and N00014-06-1-0222. Additional post-cruise analysis support was provided to RAS through the Edward W. and Betty J. Scripps Chair for Excellence in Oceanography. The OBS/Hs used in the experiment were provided by Scripps Institution of Oceanography under the U.S. National Ocean Bottom Seismic Instrumentation Pool (SIO-OBSIP—http://www.obsip.org). To cover the costs of the OBS/H deployments funds were paid to SIO-OBSIP from the National Science Foundation and from the Woods Hole Oceanographic Institution Deep Ocean Exploration Institute

    Hepatitis B surface antigen quantification: Why and how to use it in 2011 – A core group report

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    Quantitative HBsAg had been suggested to be helpful in management of HBV, but assays were cumbersome. The recent availability of commercial quantitative assays has restarted the interest in quantitative serum hepatitis B surface antigen (HBsAg) as a biomarker for prognosis and treatment response in chronic hepatitis B. HBsAg level reflects the transcriptional activity of cccDNA rather than the absolute amount of cccDNA copies. Serum HBsAg level tends to be higher in hepatitis B e antigen (HBeAg)-positive than HBeAg-negative patients. Among patients with a low HBV DNA (<2000IU/ml), HBsAg <1000IU/ml in genotype D HBV infection and HBsAg <100IU/ml in genotype B/C HBV infection is associated with inactive carrier state in HBeAg-negative patients. The HBsAg reduction by nucleos(t)ide analogues (NA) is not as pronounced as by interferon treatment. On peginterferon treatment, sustained responders tend to show greater HBsAg decline than the non-responders. The optimal on-treatment HBsAg cutoff to predict response needs further evaluation in HBeAg-positive patients, but an absence of HBsAg decline together with a <2 log reduction in HBV DNA at week 12 can serve as stopping rule in HBeAg-negative patients with genotype D HBV infection. A rapid serum HBsAg decline during NA therapy may identify patients who will clear HBsAg in the long-term. There are early reports among Asian patients that an HBsAg level of <100IU/ml might predict lower risk of relapse after stopping NA treatment. In clinical practice, serum HBsAg level should be used together with, but not as a substitute for, HBV DNA

    Factors Associated with Elevated ALT in an International HIV/HBV Co-Infected Cohort on Long-Term HAART

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    Previous studies have demonstrated that hepatitis B virus (HBV) infection increases the risk for ALT elevations in HIV-HBV co-infected patients during the first year of HAART; however, there is limited data on the prevalence of ALT elevations with prolonged HAART in this patient group.To identify factors associated with ALT elevations in an HIV-HBV co-infected cohort receiving prolonged HAART, data from 143 co-infected patients on HAART enrolled in an international HIV-HBV co-infected cohort where ALT measurements were obtained every 6 months was analysed. A person-visit analysis was used to determine frequency of ALT elevation (≥ 2.5×ULN) at each visit. Factors associated with ALT elevation were determined using multivariate logistic regression with generalized estimating equations to account for correlated data. The median time on HAART at the end of follow-up was 5.6 years (range 0.4-13.3) years. During follow-up, median ALT was 36 U/L with 10.6% of person-visits classified as having ALT elevation. Most ALT elevations were grade 2 (86.5%), with only 13.5% of all ALT elevations grade 3 or higher. Univariate associations with ALT elevation (p<0.05) included history of AIDS, HBV DNA ≥ 2,000 IU/ml, HBeAg positive, study visit CD4 <200 cells/ml and nadir CD4 <200 cells/ml. In the multivariate analysis, only study visit CD4 <200 cells/ml (OR 2.07, 95%CI 1.04-4.11, p = 0.04) and HBeAg positive status (OR 2.22, 95%CI 1.03-4.79, p = 0.04) were independently associated with ALT elevation.In this HIV-HBV co-infected cohort, elevated ALT after >1 year of HAART was uncommon, and severe ALT elevations were rare. HIV-HBV co-infected patients on long-term HAART who are either HBeAg positive or have a CD4 count of <200 cells/ml are at increased risk for ALT elevations

    The Lombard effect in singing humpback whales : source levels increase as ambient ocean noise levels increase

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    Funding: Office of Naval Research (Code 322, Marine Mammals and Biology), Commander, U.S. Pacific Fleet (Code N465JR), and the Naval Facilities Engineering Command Living Marine Resources Program.Many animals increase the intensity of their vocalizations in increased noise. This response is known as the Lombard effect. While some previous studies about cetaceans report a 1 dB increase in the source level (SL) for every dB increase in the background noise level (NL), more recent data have not supported this compensation ability. The purpose of this study was to calculate the SLs of humpback whale song units recorded off Hawaii and test for a relationship between these SLs and background NLs. Opportunistic recordings during 2012-2017 were used to detect and track 524 humpback whale encounters comprised of 83 974 units on the U.S. Navy's Pacific Missile Range Facility hydrophones. Received levels were added to their estimated transmission losses to calculate SLs. Humpback whale song units had a median SL of 173 dB re 1 μ Pa at 1 m, and SLs increased by 0.53 dB/1 dB increase in background NLs. These changes occurred in real time on hourly and daily time scales. Increases in ambient noise could reduce male humpback whale communication space in the important breeding area off Hawaii. Since these vocalization changes may be dependent on location or behavioral state, more work is needed at other locations and with other species.Publisher PDFPeer reviewe

    Increasing hepatitis B viral load is associated with risk of signi¢cant liver ¢brosis in HBeAg-negative but not HBeAg-positive chronic hepatitis B

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    Abstract Background/aims: To evaluate the association between demographical features, serum ALT and HBV DNA and the prevalence of significant fibrosis and inflammation on liver biopsy in patients with chronic hepatitis B. Methods: In this cross-sectional study of patients on St Vincent&apos;s Hospital HBV database, patients were classified into three groups on the basis of HBeAg status and HBV DNA level and the prevalence of significant (F2/3/4) fibrosis and (A2/3) inflammation in each group was established. Patients were also divided into HBeAg-positive and -negative groups and examined for the prevalence of significant fibrosis/inflammation in the strata of HBV DNA and ALT. Predictors of significant fibrosis and inflammation in HBeAg-positive and -negative patients were examined by logistic regression. Results: Three hundred and ninety four patients (HBeAg positive = 198; HBeAg negative = 196) with liver biopsy were identified. Fifty-eight percent of HBeAg-negative patients with HBV DNA 4 25 000 IU/ml had F2/3/4 fibrosis. HBV DNA and F2/3/4 were positively correlated in HBeAg-negative patients [odds ratio (OR) 1.42, P = 0.001] but inversely correlated in HBeAg-positive patients (OR 0.71, P = 0.03). HBV DNA was an independent predictor of significant fibrosis in HBeAg negative (P = 0.03) but not HBeAg-positive patients. In HBeAgpositive patients, age was the only predictor of significant fibrosis (P = 0.001) and ALT the only predictor of significant inflammation (P = 0.003). In the whole cohort there was a close positive association between inflammation and fibrosis. Conclusion: Increasing levels of HBV DNA are associated with increasing prevalence of significant fibrosis only in patients with HBeAgnegative CHB

    Update of the statements on biology and clinical impact of occult hepatitis B virus infection

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    Summary In October 2018 a large number of international experts with complementary expertise came together in Taormina to participate in a workshop on occult hepatitis B virus infection (OBI). The objectives of the workshop were to review the existing knowledge on OBI, to identify issues that require further investigation, to highlight both existing controversies and newly emerging perspectives, and ultimately to update the statements previously agreed in 2008. This paper represents the output from the workshop

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2008 update

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    Large amounts of new data on the natural history and treatment of chronic hepatitis B virus (HBV) infection have become available since 2005. These include long-term follow-up studies in large community-based cohorts or asymptomatic subjects with chronic HBV infection, further studies on the role of HBV genotype/naturally occurring HBV mutations, treatment of drug resistance and new therapies. In addition, Pegylated interferon α2a, entecavir and telbivudine have been approved globally. To update HBV management guidelines, relevant new data were reviewed and assessed by experts from the region, and the significance of the reported findings were discussed and debated. The earlier “Asian-Pacific consensus statement on the management of chronic hepatitis B” was revised accordingly. The key terms used in the statement were also defined. The new guidelines include general management, special indications for liver biopsy in patients with persistently normal alanine aminotransferase, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patients receiving immune-suppressive medications or chemotherapy and patients in the setting of liver transplantation, are also included
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