Analysis of the Mercury Distribution in Blood as a Potential Tool for Exposure Assessment - Results from Two Artisanal and Small-Scale Gold Mining Areas in Zimbabwe

People in artisanal and small-scale gold mining (ASGM) areas are frequently exposed to high levels of mercury (Hg). Hg analyses in urine and whole blood are the gold standard of biomonitoring, although this may not provide sufficient information about the source of exposure, e.g., due to the use of Hg for gold extraction or due to nutrition. To evaluate, whether the pharmacokinetic properties of individual Hg species may be useful for exposure assessment, we determined the Hg levels in different blood components from 199 participants. Therefore, whole blood was centrifuged on-site to yield erythrocytes and plasma. Globin was isolated from the erythrocytes by precipitation with ethyl acetate. Albumin was isolated from plasma by gradual precipitation with saturated ammonium sulfate solution. Hg levels in all samples were determined by using a direct Hg analyzer. Median Hg levels for whole blood, erythrocytes, and plasma were 2.7, 3.7, and 1.3 μg/l, respectively. In globin and albumin, median Hg levels were 10.3 and 7.9 μg/kg, respectively. The distribution of Hg was strongly correlated with whole blood Hg levels (p < 0.01) and the time between the last use of Hg and the date of the participation (p < 0.01). The results suggest that the distribution of Hg in blood is substantially affected by the extent and the frequency of the exposure to elemental Hg. Therefore, the analysis of Hg in erythrocytes and plasma may be a valuable tool for Hg exposure assessment in ASGM areas

Antiviral treatment with valacyclovir reduces virus shedding in saliva of Antarctic expeditioners

IntroductionReactivation of herpes viruses, such as Epstein–Barr virus (EBV), herpes simplex virus 1 (HSV1), and varicella zoster virus (VZV), increases in astronauts during spaceflight, compared with their preflight and postflight levels. Reactivations can increase the risk of associated clinical conditions, such as herpes zoster, chronic neuropathic pain, vision loss, stroke, cognitive impairment, and cold sores. Furthermore, continued viral shedding for longer periods after space travel may increase the risk of viral transmission to uninfected crew contacts, including, but not limited to, the immunocompromised and newborn infants. Thus, it is essential to develop spaceflight countermeasures to prevent herpes viral reactivations to ensure the health of crewmembers and their contacts. One such countermeasure is the prophylactic administration of an antiviral drug (valacyclovir) against the alpha herpesviruses (VZV and HSV1). To determine the effectiveness of this countermeasure, we studied the shedding of EBV, VZV, and HSV1 in Antarctic expeditioners, who have similar salivary viral shedding patterns during winter-over to astronauts during long spaceflights.MethodsThe efficacy of this antiviral drug as a countermeasure was determined using three major parameters in the saliva of expeditioners during winter-over with and without administration of this drug: (i) viral load and frequency, (ii) physiological stress biomarkers [i.e., levels of cortisol, dehydroepiandrosterone (DHEA), and amylase), and (iii) immune markers (i.e., inflammatory cytokines)]. Thirty-two volunteers from two Antarctic stations (McMurdo and South Pole) participated in this study. Participants were randomly assigned to either the treatment group (valacyclovir HCl: 1 g/day) or placebo group (oyster calcium: 500mg/day). ResultsViral shedding of EBV reduced significantly (&gt; 24-fold) in the treatment group compared with the placebo group. HSV1 was also reduced by more than fivefold, but this was not statistically significant. No VZV shedding was observed in any of the participants. In the placebo group 50% of the saliva samples had measurable viral DNA (EBV, HSV1, or both), compared with 19% of the treatment group. There was no significant change in the ratio of cortisol to DHEA or levels of alpha-amylase, indicating that physiological stress was similar between the groups. No difference was detected in levels of salivary cytokines, except IL-10, which was found in significantly lower levels in the treatment group. DiscussionThese data indicate that valacyclovir is a safe and successful intervention to reduce EBV and HSV1 shedding in individuals subjected to extreme environments and stressors

Daily and Nondaily Oral Preexposure Prophylaxis in Men and Transgender Women Who Have Sex With Men: The Human Immunodeficiency Virus Prevention Trials Network 067/ADAPT Study

Background: Nondaily dosing of oral preexposure prophylaxis (PrEP) may provide equivalent coverage of sex events compared with daily dosing. Methods: At-risk men and transgender women who have sex with men were randomly assigned to 1 of 3 dosing regimens: 1 tablet daily, 1 tablet twice weekly with a postsex dose (time-driven), or 1 tablet before and after sex (event-driven), and were followed for coverage of sex events with pre- and postsex dosing measured by weekly self-report, drug concentrations, and electronic drug monitoring. Results: From July 2012 to May 2014, 357 participants were randomized. In Bangkok, the coverage of sex events was 85% for the daily arm compared with 84% for the time-driven arm (P = .79) and 74% for the event-driven arm (P = .02). In Harlem, coverage was 66%, 47% (P = .01), and 52% (P = .01) for these groups. In Bangkok, PrEP medication concentrations in blood were consistent with use of ≥2 tablets per week in >95% of visits when sex was reported in the prior week, while in Harlem, such medication concentrations occurred in 48.5% in the daily arm, 30.9% in the time-driven arm, and 16.7% in the event-driven arm (P < .0001). Creatinine elevations were more common in the daily arm (P = .050), although they were not dose limiting. Conclusions: Daily dosing recommendations increased coverage and protective drug concentrations in the Harlem cohort, while daily and nondaily regimens led to comparably favorable outcomes in Bangkok, where participants had higher levels of education and employment

Persistent neuropsychiatric symptoms after COVID-19: a systematic review and meta-analysis.

The nature and extent of persistent neuropsychiatric symptoms after COVID-19 are not established. To help inform mental health service planning in the pandemic recovery phase, we systematically determined the prevalence of neuropsychiatric symptoms in survivors of COVID-19. For this pre-registered systematic review and meta-analysis (PROSPERO ID CRD42021239750), we searched MEDLINE, EMBASE, CINAHL and PsycINFO to 20 February 2021, plus our own curated database. We included peer-reviewed studies reporting neuropsychiatric symptoms at post-acute or later time-points after COVID-19 infection and in control groups where available. For each study, a minimum of two authors extracted summary data. For each symptom, we calculated a pooled prevalence using generalized linear mixed models. Heterogeneity was measured with I 2. Subgroup analyses were conducted for COVID-19 hospitalization, severity and duration of follow-up. From 2844 unique titles, we included 51 studies (n = 18 917 patients). The mean duration of follow-up after COVID-19 was 77 days (range 14-182 days). Study quality was most commonly moderate. The most prevalent neuropsychiatric symptom was sleep disturbance [pooled prevalence = 27.4% (95% confidence interval 21.4-34.4%)], followed by fatigue [24.4% (17.5-32.9%)], objective cognitive impairment [20.2% (10.3-35.7%)], anxiety [19.1% (13.3-26.8%)] and post-traumatic stress [15.7% (9.9-24.1%)]. Only two studies reported symptoms in control groups, both reporting higher frequencies in COVID-19 survivors versus controls. Between-study heterogeneity was high (I 2 = 79.6-98.6%). There was little or no evidence of differential symptom prevalence based on hospitalization status, severity or follow-up duration. Neuropsychiatric symptoms are common and persistent after recovery from COVID-19. The literature on longer-term consequences is still maturing but indicates a particularly high prevalence of insomnia, fatigue, cognitive impairment and anxiety disorders in the first 6 months after infection

Skeletal Muscle-Specific Ablation of γcyto-Actin Does Not Exacerbate the mdx Phenotype

We previously documented a ten-fold increase in γcyto-actin expression in dystrophin-deficient skeletal muscle and hypothesized that increased γcyto-actin expression may participate in an adaptive cytoskeletal remodeling response. To explore whether increased γcyto-actin fortifies the cortical cytoskeleton in dystrophic skeletal muscle, we generated double knockout mice lacking both dystrophin and γcyto-actin specifically in skeletal muscle (ms-DKO). Surprisingly, dystrophin-deficient mdx and ms-DKO mice presented with comparable levels of myofiber necrosis, membrane instability, and deficits in muscle function. The lack of an exacerbated phenotype in ms-DKO mice suggests γcyto-actin and dystrophin function in a common pathway. Finally, because both mdx and ms-DKO skeletal muscle showed similar levels of utrophin expression and presented with identical dystrophies, we conclude utrophin can partially compensate for the loss of dystrophin independent of a γcyto-actin-utrophin interaction

U.S. Billion-ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry

The Report, Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply (generally referred to as the Billion-Ton Study or 2005 BTS), was an estimate of “potential” biomass within the contiguous United States based on numerous assumptions about current and future inventory and production capacity, availability, and technology. In the 2005 BTS, a strategic analysis was undertaken to determine if U.S. agriculture and forest resources have the capability to potentially produce at least one billion dry tons of biomass annually, in a sustainable manner—enough to displace approximately 30% of the country’s present petroleum consumption. To ensure reasonable confidence in the study results, an effort was made to use relatively conservative assumptions. However, for both agriculture and forestry, the resource potential was not restricted by price. That is, all identified biomass was potentially available, even though some potential feedstock would more than likely be too expensive to actually be economically available. In addition to updating the 2005 study, this report attempts to address a number of its shortcoming

The redmapper galaxy cluster catalog from DES Science Verification data

We describe updates to the redMaPPer algorithm, a photometric red-sequence cluster finder specifically designed for large photometric surveys. The updated algorithm is applied to 150 {{deg}}2 of Science Verification (SV) data from the Dark Energy Survey (DES), and to the Sloan Digital Sky Survey (SDSS) DR8 photometric data set. The DES SV catalog is locally volume limited and contains 786 clusters with richness lambda \gt 20 (roughly equivalent to {M}{{500c}}≳ {10}14 {h}70-1 {M}o ) and 0.2\lt z\lt 0.9. The DR8 catalog consists of 26,311 clusters with 0.08\lt z\lt 0.6, with a sharply increasing richness threshold as a function of redshift for z≳ 0.35. The photometric redshift performance of both catalogs is shown to be excellent, with photometric redshift uncertainties controlled at the {sigma }z/(1+z)~ 0.01 level for z≲ 0.7, rising to ~0.02 at z~ 0.9 in DES SV. We make use of Chandra and XMM X-ray and South Pole Telescope Sunyaev--Zeldovich data to show that the centering performance and mass--richness scatter are consistent with expectations based on prior runs of redMaPPer on SDSS data. We also show how the redMaPPer photo-z and richness estimates are relatively insensitive to imperfect star/galaxy separation and small-scale star masks

The evolution of active galactic nuclei in clusters of galaxies from the Dark Energy Survey

The correlation between active galactic nuclei (AGNs) and environment provides important clues to AGN fuelling and the relationship of black hole growth to galaxy evolution. In this paper, we analyse the fraction of galaxies in clusters hosting AGN as a function of redshift and cluster richness for X-ray-detected AGN associated with clusters of galaxies in Dark Energy Survey (DES) Science Verification data. The present sample includes 33 AGNs with LX > 1043 erg s−1 in non-central, host galaxies with luminosity greater than 0.5L* from a total sample of 432 clusters in the redshift range of 0.1 0.7. This result is in good agreement with previous work and parallels the increase in star formation in cluster galaxies over the same redshift range. However, the AGN fraction in clusters is observed to have no significant correlation with cluster mass. Future analyses with DES Year 1 through Year 3 data will be able to clarify whether AGN activity is correlated to cluster mass and will tightly constrain the relationship between cluster AGN populations and redshift

The XMM cluster survey: exploring scaling relations and completeness of the dark energy survey year 3 redMaPPer cluster catalogue

We cross-match and compare characteristics of galaxy clusters identified in observations from two sky surveys using two completely different techniques. One sample is optically selected from the analysis of 3 years of Dark Energy Survey observations using the redMaPPer cluster detection algorithm. The second is X-ray selected from XMM observations analysed by the XMM Cluster Survey. The samples comprise a total area of 57.4 deg2, bounded by the area of four contiguous XMM survey regions that overlap the DES footprint. We find that the X-ray-selected sample is fully matched with entries in the redMaPPer catalogue, above λ > 20 and within 0.1 <0.9. Conversely, only 38 per cent of the redMaPPer catalogue is matched to an X-ray extended source. Next, using 120 optically clusters and 184 X-ray-selected clusters, we investigate the form of the X-ray luminosity-temperature (LX -TX ), luminosity-richness (LX -λ), and temperature-richness (TX -λ) scaling relations. We find that the fitted forms of the LX -TX relations are consistent between the two selection methods and also with other studies in the literature. However, we find tentative evidence for a steepening of the slope of the relation for low richness systems in the X-ray-selected sample. When considering the scaling of richness with X-ray properties, we again find consistency in the relations (i.e. LX -λ and TX -λ) between the optical and X-ray-selected samples. This is contrary to previous similar works that find a significant increase in the scatter of the luminosity scaling relation for X-ray-selected samples compared to optically selected samples