39 research outputs found

    Impact of Virologic Breakthrough and HBIG Regimen on Hepatitis B Recurrence After Liver Transplantation

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    The availability of hepatitis B immune globulin (HBIG) and several oral antiviral therapies has reduced but not eliminated hepatitis B virus (HBV) recurrence. We aimed to determine the rate of HBV recurrence after orthotopic liver transplantation (OLT) in relation to virologic breakthrough pre-OLT and HBIG regimens post-OLT. Data from the NIH HBV-OLT database were analyzed. A total of 183 patients transplanted between 2001 and 2007 followed for a median of 42 months (range 1–81) post-OLT were studied. At transplant, 29% were hepatitis B e antigen (HBeAg) (+), 38.5% had HBV DNA > 5 log 10 copies/mL, 74% were receiving antiviral therapy. Twenty-five patients experienced virologic breakthrough before OLT. Post-OLT, 26%, 22%, 40% and 12% of patients received intravenous (IV) high-dose, IV low-dose, intramuscular low-dose and a finite duration of HBIG, respectively as maintenance prophylaxis. All but two patients also received antiviral therapy. Cumulative rates of HBV recurrence at 1 and 5 years were 3% and 9%, respectively. Multivariate analysis showed that listing HBeAg status and HBV DNA level at OLT were the only factors associated with HBV recurrence. In conclusion, low rates of HBV recurrence can be accomplished with all the HBIG regimens used when combined with antiviral therapy including patients with breakthrough pre-OLT as long as rescue therapy is administered pre- and post-OLT.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79358/1/j.1600-6143.2010.03046.x.pd

    Systematic KMTNet Planetary Anomaly Search. V. Complete Sample of 2018 Prime-Field

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    We complete the analysis of all 2018 prime-field microlensing planets identified by the KMTNet AnomalyFinder. Among the 10 previously unpublished events with clear planetary solutions, 8 are either unambiguously planetary or are very likely to be planetary in nature: OGLE-2018-BLG-1126, KMT-2018-BLG-2004, OGLE-2018-BLG-1647, OGLE-2018-BLG-1367, OGLE-2018-BLG-1544, OGLE-2018-BLG-0932, OGLE-2018-BLG-1212, and KMT-2018-BLG-2718. Combined with the 4 previously published new AnomalyFinder events and 12 previously published (or in preparation) planets that were discovered by eye, thismakes a total of 24 2018 prime-field planets discovered or recovered by AnomalyFinder. Together with a paper in preparation on 2018 sub-prime planets, this work lays the basis for the first statistical analysis of the planet mass-ratio function based on planets identified in KMTNet data. By systematically applying the heuristic analysis of Hwang et al. (2022) to each event, we identify the small modification in their formalism that is needed to unify the so-called close/wide and inner/outer degeneracies, as conjectured byComment: 22 pages, 14 tables, 15 figure

    Systematic KMTNet Planetary Anomaly Search, Paper I: OGLE-2019-BLG-1053Lb, A Buried Terrestrial Planet

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    In order to exhume the buried signatures of "missing planetary caustics" in the KMTNet data, we conducted a systematic anomaly search to the residuals from point-source point-lens fits, based on a modified version of the KMTNet EventFinder algorithm. This search reveals the lowest mass-ratio planetary caustic to date in the microlensing event OGLE-2019-BLG-1053, for which the planetary signal had not been noticed before. The planetary system has a planet-host mass ratio of q=(1.25±0.13)×105q = (1.25 \pm 0.13) \times 10^{-5}. A Bayesian analysis yields estimates of the mass of the host star, Mhost=0.610.24+0.29 MM_{\rm host} = 0.61_{-0.24}^{+0.29}~M_\odot, the mass of its planet, Mplanet=2.480.98+1.19 MM_{\rm planet} = 2.48_{-0.98}^{+1.19}~M_{\oplus}, the projected planet-host separation, a=3.40.5+0.5a_\perp = 3.4_{-0.5}^{+0.5} au, and the lens distance of DL=6.80.9+0.6D_{\rm L} = 6.8_{-0.9}^{+0.6} kpc. The discovery of this very low mass-ratio planet illustrates the utility of our method and opens a new window for a large and homogeneous sample to study the microlensing planet-host mass-ratio function down to q105q \sim 10^{-5}.Comment: published by A

    Investigating the role of microbes in mineral weathering: Nanometre-scale characterisation of the cell-mineral interface using FIB and TEM

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    Focused ion beam (FIB) sample preparation in combination with subsequent transmission electron microscopy (TEM) analysis are powerful tools for nanometre-scale examination of the cell-mineral interface in bio-geological samples. In this study, we used FIB-TEM to investigate the interaction between a cyanobacterium (Hassallia byssoidea) and a common sheet silicate mineral (biotite) following a laboratory-based bioweathering, incubation experiment. We discuss the FIB preparation of cross-sections of the cell mineral interface for TEM investigation. We also establish an electron fluence threshold (at 200. keV) in biotite for the transition from scanning (S)TEM electron beam induced contamination build up on the surface of biotite thin sections to mass loss, or hole-drilling within the sections. Working below this threshold fluence nanometre-scale structural and elemental information has been obtained from biotite directly underneath cyanobacterial cells incubated on the biotite for 3 months. No physical alteration of the biotite was detected by TEM imaging and diffraction with little or no elemental alteration detected by STEM-energy dispersive X-ray (EDX) elemental line-scanning or by energy filtered TEM (EF-TEM) jump ratio elemental mapping. As such we present evidence that the cyanobacterial strain of H. byssoidea did not cause any measurable alteration of biotite, within the resolution limits of the analysis techniques used, after 3 months of incubation on its surface

    The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts

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    Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species’ threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015

    Preliminary results: Outcome of liver transplantation for hepatitis B virus varies by hepatitis B virus genotype

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    Hepatitis B virus (HBV) is a leading cause of liver failure throughout the world. HBV has seven different genotypes based on variations within the viral nucleotide sequence. Initially, patients who underwent liver transplantation for HBV had high recurrence rates and poor survival. Recently, improved outcomes have been reported when patients are administered hepatitis B immunoglobulin (HBIg) infusions to maintain high serum hepatitis B surface antibody titers after transplantation. Unfortunately, recurrence rates are still high in patients with active pretransplant HBV replication. The aims of this study are to evaluate the impact of HBV genotype on pretransplantation HBV replication and posttransplantation HBV recurrence rate, morbidity, and mortality. Sera from 22 patients who underwent transplantation for HBV at our center were tested for HBV genotype by an enzyme-linked immunosorbent assay technique using monoclonal antibodies to the pre-S2 region. All patients were administered HBIg after transplantation; 5 patients were administered both lamivudine and HBIg. HBV genotypes were distributed as follows: genotype A (10 patients), genotype C (6 patients), genotype D (5 patients), and genotype E (1 patient). Pretransplantation HBV replication was most common with genotype A (80%), whereas less so with genotypes C (33%) and D (40%). Nine patients (41%) developed recurrent HBV infection: genotype A (2 patients; 20%), genotype C (3 patients; 50%), and genotype D (4 patients; 80%). Mortality was greatest with genotype D (40%). Our data suggest that patients with genotype A have the lowest risk for HBV recurrence despite having the highest rate of pretransplantation HBV viral replication. Patients with genotype D appear to have the highest risk for HBV recurrence and mortality. Additional larger multicenter studies are needed to confirm these findings
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