481 research outputs found
Prevalence and clinical features of patients with concurrent HBsAg and antiâHBs: Evaluation of the hepatitis B research network cohort
The prevalence of concurrent HBsAg and antiâHBs in plasma of persons with chronic hepatitis B virus (HBV) infection is variable and its clinical significance enigmatic. We examined the prevalence and clinical and virological features of concurrent HBsAg and antiâHBs in children and adults with chronic HBV infection living in North America. A total of 1462 HBsAg positive participants in the Hepatitis B Research Network paediatric and adult cohorts were included (median age 41 (range 4â80) years, 48% female, 11% white, 13% black, 73% Asians). Only 18 (1.2%) were found to be antiâHBs positive (âĽ10 mIU/mL) at initial study evaluation. Distributions of sex, race, HBV genotype and ALT were similar between participants with and without concurrent antiâHBs. Those who were antiâHBs positive appeared to be older (median age 50 vs 41 years, P = .06), have lower platelet counts (median 197 vs 222 Ă 103/mm3, P = .07) and have higher prevalence of HBeAg (44% vs 26%, P = .10). They also had lower HBsAg levels (median 2.0 vs 3.5 log10 IU/mL, P = .02). Testing of followâup samples after a median of 4 years (range 1â6) in 12 of the 18 participants with initial concurrent antiâHBs showed antiâHBs became undetectable in 6, decreased to <10 mIU/mL in 1 and remained positive in 5 participants. Two patients lost HBsAg during followâup. In conclusion, prevalence of concurrent HBsAg and antiâHBs was low at 1.2%, with antiâHBs disappearing in some during followâup, in this large cohort of racially diverse children and adults with chronic HBV infection living in North America. Presence of concurrent HBsAg and antiâHBs did not identify a specific phenotype of chronic hepatitis B, nor did it appear to affect clinical outcomes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156489/3/jvh13312.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156489/2/jvh13312-sup-0001-FigS1-S3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156489/1/jvh13312_am.pd
Objectively measured physical activity of USA adults by sex, age, and racial/ethnic groups: a cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Accelerometers were incorporated in the 2003â2004 National Health and Nutritional Examination Survey (NHANES) study cycle for objective assessment of physical activity. This is the first time that objective physical activity data are available on a nationally representative sample of U.S. residents. The use of accelerometers allows researchers to measure total physical activity, including light intensity and unstructured activities, which may be a better predictor of health outcomes than structured activity alone. The aim of this study was to examine objectively determined physical activity levels by sex, age and racial/ethnic groups in a national sample of U.S. adults.</p> <p>Methods</p> <p>Data were obtained from the 2003â2004 NHANES, a cross-sectional study of a complex, multistage probability sample of the U.S. population. Physical activity was assessed with the Actigraph AM-7164 accelerometer for seven days following an examination. 2,688 U.S. adults with valid accelerometer data (i.e. at least four days with at least 10 hours of wear-time) were included in the analysis. Mean daily total physical activity counts, as well as counts accumulated in minutes of light, and moderate-vigorous intensity physical activity are presented by sex across age and racial/ethnic groups. Generalized linear modeling using the log link function was performed to compare physical activity in sex and racial/ethnic groups adjusting for age.</p> <p>Results</p> <p>Physical activity decreases with age for both men and women across all racial/ethnic groups with men being more active than women, with the exception of Hispanic women. Hispanic women are more active at middle age (40â59 years) compared to younger or older age and not significantly less active than men in middle or older age groups (i.e. age 40â59 or age 60 and older). Hispanic men accumulate more total and light intensity physical activity counts than their white and black counterparts for all age groups.</p> <p>Conclusion</p> <p>Physical activity levels measured objectively by accelerometer demonstrated that Hispanic men are, in general, more active than their white and black counterparts. This appears to be in contrast to self-reported physical activity previously reported in the literature and identifies the need to use objective measures in situations where the contribution of light intensity and/or unstructured physical activity cannot be assumed homogenous across the populations of interest.</p
Fold Lens Flux Anomalies: A Geometric Approach
We develop a new approach for studying flux anomalies in quadruply-imaged
fold lens systems. We show that in the absence of substructure, microlensing,
or differential absorption, the expected flux ratios of a fold pair can be
tightly constrained using only geometric arguments. We apply this technique to
11 known quadruple lens systems in the radio and infrared, and compare our
estimates to the Monte Carlo based results of Keeton, Gaudi, and Petters. We
show that a robust estimate for a flux ratio from a smoothly varying potential
can be found, and at long wavelengths those lenses deviating from from this
ratio almost certainly contain significant substructure.Comment: 16 pages, including 8 figure
Physical Activity Levels of Patients Undergoing Bariatric Surgery in the Longitudinal Assessment of Bariatric Surgery (LABS) Study
Background- Bariatric surgery candidates' physical activity (PA) level may contribute to the variability of weight loss and body composition changes following bariatric surgery. However, there is little research describing the PA of patients undergoing bariatric surgery to inform PA recommendations in preparation for, and following, surgery.
Objectives- Describe PA assessment in the LABS-2 study and report pre-surgery PA level. Examine relationships between objectively determined PA level and 1) BMI and 2) self-reported purposeful exercise.
Setting- Six sites in the U.S.
Methods- Participants wore an accelerometer and completed a PA diary. Standardized measures of height and weight were obtained.
Results- Of 757 participants, 20% were sedentary (<5000 steps/day), 34% low active (5000-7499 steps/day), 27% somewhat active (7500-9999 steps/day), 14% active (10000-12499 steps/day), and 6% were highly active (greater than or equal to 12500 steps/day). BMI was inversely related to mean steps/day and mean steps/minute during the most active 30 minutes each day. The most commonly reported activities were walking, 44%; gardening, 11%; playing with children, 10%; and stretching, 7%. Self-report of minutes of exercise accounted for 2% of the variance in objectively determined steps.
Conclusion- Patients present for bariatric surgery with a wide range of PA levels, with almost half categorized as somewhat active or active. BMI is inversely related to total amount and intensity of PA. Few patients report a regular pre-operative exercise regimen suggesting most PA is accumulated from activities of daily living. Patient report of daily minutes of walking or exercise may not be a reliable indication of their PA level. Originally published Surgery for Obesity and Related Diseases, Vol. 4, No. 6, Nov-Dec 200
Ecological and Genomic Attributes of Novel Bacterial Taxa That Thrive in Subsurface Soil Horizons.
While most bacterial and archaeal taxa living in surface soils remain undescribed, this problem is exacerbated in deeper soils, owing to the unique oligotrophic conditions found in the subsurface. Additionally, previous studies of soil microbiomes have focused almost exclusively on surface soils, even though the microbes living in deeper soils also play critical roles in a wide range of biogeochemical processes. We examined soils collected from 20 distinct profiles across the United States to characterize the bacterial and archaeal communities that live in subsurface soils and to determine whether there are consistent changes in soil microbial communities with depth across a wide range of soil and environmental conditions. We found that bacterial and archaeal diversity generally decreased with depth, as did the degree of similarity of microbial communities to those found in surface horizons. We observed five phyla that consistently increased in relative abundance with depth across our soil profiles: Chloroflexi, Nitrospirae, Euryarchaeota, and candidate phyla GAL15 and Dormibacteraeota (formerly AD3). Leveraging the unusually high abundance of Dormibacteraeota at depth, we assembled genomes representative of this candidate phylum and identified traits that are likely to be beneficial in low-nutrient environments, including the synthesis and storage of carbohydrates, the potential to use carbon monoxide (CO) as a supplemental energy source, and the ability to form spores. Together these attributes likely allow members of the candidate phylum Dormibacteraeota to flourish in deeper soils and provide insight into the survival and growth strategies employed by the microbes that thrive in oligotrophic soil environments.IMPORTANCE Soil profiles are rarely homogeneous. Resource availability and microbial abundances typically decrease with soil depth, but microbes found in deeper horizons are still important components of terrestrial ecosystems. By studying 20 soil profiles across the United States, we documented consistent changes in soil bacterial and archaeal communities with depth. Deeper soils harbored communities distinct from those of the more commonly studied surface horizons. Most notably, we found that the candidate phylum Dormibacteraeota (formerly AD3) was often dominant in subsurface soils, and we used genomes from uncultivated members of this group to identify why these taxa are able to thrive in such resource-limited environments. Simply digging deeper into soil can reveal a surprising number of novel microbes with unique adaptations to oligotrophic subsurface conditions
Australian students transitioning through the âlost yearâ of higher education
The Issue Student transitions through university have previously focussed on the move into first year (retention and success strategies) from high school or out of university into the workforce (with career readiness and employability). However, second year transitions have only recently begun to attract attention as an area where students may experience hurdles which impact on their progression and overall degree experience and success. Evidence from Australian universities to date has shown similarities between Australian and International second year science cohorts in their thriving behaviours and their risk of academic slump (Loughlin et al, 2013; Gregory & McDonnell, 2012)
Previous success strategies have looked at initial transition into second year (McBurnie et al, 2012, Harrison, 2007) or an embedded support strategy (Quinlavan, 2010). However, a more holistic approach to second year transition using multiple interventions is more likely to demonstrate long-term impact on student transition and success. There is also a need to gather more evidence of the âsophomore slumpâ within Australian institutions and to work collaboratively to achieve this.
Approach Currently at Griffith University in the School of Biomolecular & Physical Sciences multiple aspects of engagement scheme has been implemented across all year levels. However, in second year, identifying and reflecting on individual student cohort challenges and providing support as appropriate is being trialled. Elements of both curricular and co-curricular in activities are incorporated, staff awareness is being developed and the entire process is being overseen by a second year student co-ordinator.
At James Cook University initial interest has been cultivated with early adoption of identification of second year challenges specifically in the Faculties of Health and Arts/Education.
At Deakin University a successful re-introduction activity for second year students has been hosted for several years and uptake of the Thriving Quotient survey will occur in 2013.
At University of South Australia early interest in second year student transitions has developed from first year activities with initial evaluations being conducted.
Development of a cross-institutional OLT submission for 2014 that looks at both gathering more evidence of slump using a triangulated data approach and then investigating and evaluating activities that will potentially reduce the impact slump may have on persistence and progression
Marine Mammal Brucella Genotype Associated with Zoonotic Infection
Marine Mammal Brucella Genotype Associated with Zoonotic Infectio
Sediment Cores from White Pond, South Carolina, contain a Platinum Anomaly, Pyrogenic Carbon Peak, and Coprophilous Spore Decline at 12.8 ka
A widespread platinum (Pt) anomaly was recently documented in Greenland ice and 11 North American sedimentary sequences at the onset of the Younger Dryas (YD) event (~12,800ââŹâ°calââŹâ°yr BP), consistent with the YD Impact Hypothesis. We report high-resolution analyses of a 1-meter section of a lake core from White Pond, South Carolina, USA. After developing a Bayesian age-depth model that brackets the late Pleistocene through early Holocene, we analyzed and quantified the following: (1) Pt and palladium (Pd) abundance, (2) geochemistry of 58 elements, (3) coprophilous spores, (4) sedimentary organic matter (OC and sedaDNA), (5) stable isotopes of C (Ă´13C) and N (Ă´15N), (6) soot, (7) aciniform carbon, (8) cryptotephra, (9) mercury (Hg), and (10) magnetic susceptibility. We identified large Pt and Pt/Pd anomalies within a 2-cm section dated to the YD onset (12,785ââŹâ°Ă¹ââŹâ°58ââŹâ°calââŹâ°yr BP). These anomalies precede a decline in coprophilous spores and correlate with an abrupt peak in soot and C/OC ratios, indicative of large-scale regional biomass burning. We also observed a relatively large excursion in Ă´15N values, indicating rapid climatic and environmental/hydrological changes at the YD onset. Our results are consistent with the YD Impact Hypothesis and impact-related environmental and ecological changes
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The first 20 months of the COVID-19 pandemic: Mortality, intubation and ICU rates among 104,590 patients hospitalized at 21 United States health systems
Main objective: There is limited information on how patient outcomes have changed during the COVID-19 pandemic. This study characterizes changes in mortality, intubation, and ICU admission rates during the first 20 months of the pandemic. Study design and methods: University of Wisconsin researchers collected and harmonized electronic health record data from 1.1 million COVID-19 patients across 21 United States health systems from February 2020 through September 2021. The analysis comprised data from 104,590 adult hospitalized COVID-19 patients. Inclusion criteria for the analysis were: (1) age 18 years or older; (2) COVID-19 ICD-10 diagnosis during hospitalization and/or a positive COVID-19 PCR test in a 14-day window (+/- 7 days of hospital admission); and (3) health system contact prior to COVID-19 hospitalization. Outcomes assessed were: (1) mortality (primary), (2) endotracheal intubation, and (3) ICU admission. Results and significance: The 104,590 hospitalized participants had a mean age of 61.7 years and were 50.4% female, 24% Black, and 56.8% White. Overall risk-standardized mortality (adjusted for age, sex, race, ethnicity, body mass index, insurance status and medical comorbidities) declined from 16% of hospitalized COVID-19 patients (95% CI: 16% to 17%) early in the pandemic (February-April 2020) to 9% (CI: 9% to 10%) later (July-September 2021). Among subpopulations, males (vs. females), those on Medicare (vs. those on commercial insurance), the severely obese (vs. normal weight), and those aged 60 and older (vs. younger individuals) had especially high mortality rates both early and late in the pandemic. ICU admission and intubation rates also declined across these 20 months. Conclusions: Mortality, intubation, and ICU admission rates improved markedly over the first 20 months of the pandemic among adult hospitalized COVID-19 patients although gains varied by subpopulation. These data provide important information on the course of COVID-19 and identify hospitalized patient groups at heightened risk for negative outcomes. Trial registration: ClinicalTrials.gov Identifier: NCT04506528 (https://clinicaltrials.gov/ct2/show/NCT04506528).</p
Biological and Clinical Implications of Gene-Expression Profiling in Diffuse Large B-Cell Lymphoma:A Proposal for a Targeted BLYM-777 Consortium Panel as Part of a Multilayered Analytical Approach
Gene-expression profiling (GEP) is used to study the molecular biology of lymphomas. Here, advancing insights from GEP studies in diffuse large B-cell lymphoma (DLBCL) lymphomagenesis are discussed. GEP studies elucidated subtypes based on cell-of-origin principles and profoundly changed the biological understanding of DLBCL with clinical relevance. Studies integrating GEP and next-generation DNA sequencing defined different molecular subtypes of DLBCL entities originating at specific anatomical localizations. With the emergence of high-throughput technologies, the tumor microenvironment (TME) has been recognized as a critical component in DLBCL pathogenesis. TME studies have characterized so-called âlymphoma microenvironments" and âecotypesâ. Despite gained insights, unexplained chemo-refractoriness in DLBCL remains. To further elucidate the complex biology of DLBCL, we propose a novel targeted GEP consortium panel, called BLYM-777. This knowledge-based biology-driven panel includes probes for 777 genes, covering many aspects regarding B-cell lymphomagenesis (f.e., MYC signature, TME, immune surveillance and resistance to CAR T-cell therapy). Regarding lymphomagenesis, upcoming DLBCL studies need to incorporate genomic and transcriptomic approaches with proteomic methods and correlate these multi-omics data with patient characteristics of well-defined and homogeneous cohorts. This multilayered methodology potentially enhances diagnostic classification of DLBCL subtypes, prognostication, and the development of novel targeted therapeutic strategies. Simple Summary: This review summarizes gene-expression profiling insights into the background and origination of diffuse large B-cell lymphomas (DLBCL). To further unravel the molecular biology of these lymphomas, a consortium panel called BLYM-777 was designed including genes important for subtype classifications, genetic pathways, tumor-microenvironment, immune response and resistance to targeted therapies. This review proposes to combine this transcriptomic method with genomics, proteomics, and patient characteristics to facilitate diagnostic classification, prognostication, and the development of new targeted therapeutic strategies in DLBCL
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