Hg Ratio Research Articles

Intergenerational transmission of the structure of the auditory cortex and reading skills.

High-level cognitive skill development relies on genetic and environmental factors, tied to brain structure and function. Inter-individual variability in language and music skills has been repeatedly associated with the structure of the auditory cortex: the shape, size and asymmetry of the transverse temporal gyrus (TTG) or gyri (TTGs). TTG is highly variable in shape and size, some individuals having one single gyrus (also referred to as Heschl's gyrus, HG) while others presenting duplications (with a common stem or fully separated) or higher-order multiplications of TTG. Both genetic and environmental influences on children's cognition, behavior, and brain can to some to degree be traced back to familial and parental factors. In the current study, using a unique MRI dataset of parents and children (135 individuals from 37 families), we ask whether the anatomy of the auditory cortex is related to reading skills, and whether there are intergenerational effects on TTG(s) anatomy. For this, we performed detailed, automatic segmentations of HG and of additional TTG(s), when present, extracting volume, surface area, thickness and shape of the gyri. We tested for relationships between these and reading skill, and assessed their degree of familial similarity and intergenerational transmission effects. We found that volume and area of all identified left TTG(s) combined was positively related to reading scores, both in children and adults. With respect to intergenerational similarities in the structure of the auditory cortex, we identified structural brain similarities for parent-child pairs of the 1st TTG (Heschl's gyrus, HG) (in terms of volume, area and thickness for the right HG, and shape for the left HG) and of the lateralization of all TTG(s) surface area for father-child pairs. Both the HG and TTG-lateralization findings were significantly more likely for parent-child dyads than for unrelated adult-child pairs. Furthermore, we established characteristics of parents' TTG that are related to better reading abilities in children: fathers' small left HG, and a small ratio of HG to planum temporale. Our results suggest intergenerational transmission of specific structural features of the auditory cortex; these may arise from genetics and/or from shared environment.

Solid-structured phosphine sulfide as a new precursor in the synthesis of mercury sulfide quantum dots

Tricyclohexylphosphine sulfide (Cy)3PS, a solid-structured phosphine sulfide precursor, was used for the first time in the synthesis of sphere-shaped colloidally stable β-HgS CQDs. DFT calculations applying the TPSS-D3/def2-TZVP level of theory in the gas phase showed that the chemical reactivity of the titled precursor is similar to that of TOPS. The nanocrystals produced using HgCl2/(Cy)3PS/THF were colloidally stable, possessing near- and mid-infrared absorptions. As the reaction time increased, the first excitonic peaks were redshifted in the near-infrared window between 0.8 and 1.1 µm. Meanwhile, the red shifting of the mid-wavelength intraband (1Se‐1Pe) absorption peaks was between 3.9 and 4.8 µm. A good agreement between the diameters calculated using the atomistic tight-binding approach and those obtained using TEM was observed. The concentration and molar absorption coefficient (ε400) of the prepared QDs were determined as well. An increase in the ε400 of the quantum dots with increasing reaction time was shown. XPS elemental analysis showed that HgS NCs with a nearly equal atomic ratio of Hg:S were poorly colloidally stable, and their FT-IR spectra had no intraband absorptions in the mid-IR window. Meanwhile, high colloidally stable and mid-wavelength intraband absorption peaks in the FT-IR spectra were shown for mercury-rich HgS CQDs.

Trace element concentrations in common dolphins (Delphinus delphis) in the Celtic Seas ecoregion: Interelement relationships and effects of life history and health status

Given the increased extraction of trace elements for use by new and emerging technologies, monitoring the environmental fate and potential effects of these compounds within the aquatic environment has never been more critical. Here, hepatic trace element concentrations were assessed in a key sentinel predator, the common dolphin (Delphinus delphis), using a long-term dataset. Variation in concentrations were assessed in relation to other elements, time period, decomposition state, sex, age, total body length, sexual maturity and nutritional status, and cause of death. Additionally, mercury toxicity thresholds for evaluating risk were reviewed and employed. Concentrations of elements which bioaccumulate, THg, MeHg, Cd, and Pb, in addition to Se and V, were strongly correlated with age, and/or body length. An association was observed between Zn concentrations and disease status, with significantly higher concentrations measured in individuals that died from infectious disease, compared to other causes. Strong inter-elemental relationships were detected, namely between Hg and Se, MeHg and Se, Cd and Se, and Cu and Zn. While THg:Se molar ratio values were observed to increase with age and body length, approaching equimolarity. THg was largely comprised of inorganic Hg in older individuals, potentially bound to Se, therefore the effects from THg toxicity may possibly be less important than originally assumed. In contrast, higher MeHg:Hg ratio values were reported in juveniles, suggesting a poorer efficiency in demethylation and a higher sensitivity. The generation of data on proportions of hepatic MeHg and inorganic Hg is highly informative to both future toxicity threshold assessments within pollutant indicator assessments, and to understanding the ultimate fate of mercury in the marine web.

Biomonitoring of mercury and selenium in commercially important shellfish: Distribution pattern, health benefit assessment and consumption advisories.

This study aims to explore the concentrations of Se and Hg in shellfish along the Gulf of Mannar (GoM) coast (Southeast India) and to estimate related risks and risk-based consumption limits for children, pregnant women, and adults. Se concentrations in shrimp, crab, and cephalopods ranged from 0.256 to 0.275mgkg-1, 0.182 to 0.553mgkg-1, and 0.176 to 0.255mgkg-1, respectively, whereas Hg concentrations differed from 0.009 to 0.014mgkg-1, 0.022 to 0.042mgkg-1 and 0.011 to 0.024mgkg-1, respectively. Se and Hg content in bamboo shark (C. griseum) was 0.242mgkg-1 and 0.082mgkg-1, respectively. The lowest and highest Se concentrations were found in C. indicus (0.176mgkg-1) and C. natator (0.553mgkg-1), while Hg was found high in C. griseum (0.082mgkg-1) and low in P. vannamei (0.009mgkg-1). Se shellfishes were found in the following order: crabs > shrimp > shark > cephalopods, while that of Hg were shark > crabs > cephalopods > shrimp. Se in shellfish was negatively correlated with trophic level (TL) and size (length and weight), whereas Hg was positively correlated with TL and size. Hg concentrations in shellfish were below the maximum residual limits (MRL) of 0.5mgkg-1 for crustaceans and cephalopods set by FSSAI, 0.5mgkg-1 for crustaceans and 1.0mgkg-1 for cephalopods and sharks prescribed by the European Commission (EC/1881/2006). Se risk-benefit analysis, the AI (actual intake):RDI (recommended daily intake) ratio was > 100%, and the AI:UL (upper limit) ratio was < 100%, indicating that all shellfish have sufficient level of Se to meet daily requirements without exceeding the upper limit (UL). The target hazard quotient (THQ < 1) and hazard index (HI < 1) imply that the consumption of shellfish has no non-carcinogenic health impacts for all age groups. However, despite variations among the examined shellfish, it was consistently observed that they all exhibited a Se:Hg molar ratio > 1. This finding implies that the consumption of shellfish is generally safe in terms of Hg content. The health benefit indexes, Se-HBV and HBVse, consistently showed high positive values across all shellfish, further supporting the protective influence of Se against Hg toxicity and reinforcing the overall safety of shellfish consumption. Enhancing comprehension of food safety analysis, it is crucial to recognize that the elevated Se:Hg ratio in shellfish may be attributed to regular selenoprotein synthesis and the mitigation of Hg toxicity by substituting Se bound to Hg.

Selenium and mercury concentrations, Se:Hg molar ratios and their effect on the antioxidant system in wild mammals

The aim of this study was to a) evaluate the concentration of Se and Hg and their relationship in the tissues of 4 species of wild mammals, including Se:Hg molar ratios, and b) evaluate the effect of the analysed elements and their mutual proportions expressed as Se:Hg molar ratio, on the antioxidant system in the tissues of the tested animals. The study was performed on 31 animals belonging to four species: wild boar, red fox, roe deer, brown hare. Determination of Hg in liver, kidney and muscle of animals was performed using an AMA 254 mercury analyser. Total Se concentrations were determined using the spectrofluorometric method.In omnivores demonstrated higher Se concentrations in all analysed organs compared to the herbivores. The highest concentration of Hg was found in the kidneys of the tested animals, and the lowest in the muscles. High and moderate correlation between Se and Hg was observed in the liver of omnivorous, while in herbivores this correlation was weak. In all analysed samples, the Se:Hg molar ratios were above 1 (min: liver 5.9, max: kidney 110). Generally, the highest Se:Hg ratio values were found in kidney and the lowest in liver of tested animals. No significant correlation was found between GPx, GST and SOD activity and Se or Hg concentration in analysed organs. But it was observed that Se:Hg molar was negatively correlated with CAT activity in the most samples.The obtained results may suggest that omnivorous animals demonstrate greater Hg sequestration in the liver than herbivores, which has been proposed as one of the mechanisms of Se antagonistic action towards Hg. The ratio between Se and Hg, rather than the concentration of these elements in organs, affected the antioxidant status in the animal organism, specifically the CAT activity.

Volcanism and carbon cycle perturbations in the High Arctic during the Late Jurassic – Early Cretaceous

Large perturbations in the global carbon cycle recorded as carbon-isotope (δ13C) excursions (CIEs) in both organic carbon and carbonate records have been linked to volcanism during the emplacement of Large Igneous Provinces (LIPs). This link is based primarily on the purported temporal coincidence between CIEs and LIP emplacement. Mercury (Hg) concentration in sedimentary rocks has been used as a regional to global tracer of large-scale volcanic activity, yet few studies have been undertaken on Upper Jurassic – Lower Cretaceous sediments from Boreal localities compared to those for Tethyan (northern mid-latitude) successions. This has limited our understanding of the regional-to-global spatial impact of volcanic activity during this period. This study examines the Hg record as a proxy for volcanism, and the δ13C records from organic matter (δ13Corg) of CIEs from the uppermost Jurassic to Lower Cretaceous (Callovian – Aptian) successions from Axel Heiberg and Spitsbergen in the Canadian Arctic and Svalbard archipelagos, respectively. This interval includes three regional- to global CIEs. These sections show no significant variation in the ratio of Hg to total organic carbon (TOC) across the Boreal-wide Volgian negative CIE (Volgian Isotopic Carbon Excursion, “VOICE”), which has not been associated with LIP volcanism. The examined successions spanning this interval all show some influence from changing environmental or post-burial parameters, however, which could have (partially) overprinted a volcanic signal. Despite some problems in stratigraphically constraining the Weissert Event, increased Hg/TOC ratios are observed across this interval, which may be partially driven by volcanism associated with the emplacement of the Paraná-Etendeka Traps. A spike in Hg/TOC is observed immediately prior to the negative peak of the Aptian Oceanic Anoxic Event (OAE1a) CIE, supporting recent evidence of a pulse of High Arctic Large Igneous Province (HALIP) volcanic activity preceding this oceanic anoxic event.

The effect of mono‐diglycerides on the mechanical properties, microstructure, and physical stability of an edible rice bran wax–gelatin biphasic gel system

AbstractBigels are prepared by homogenization of an organogel and hydrogel. Bigels can offer improved properties such as enhanced physical stability and the ability to interact with both hydrophilic and lipophilic moieties and substances when compared to other gelled systems due to its semi‐solid internal phase, biphasic nature, and supramolecular interactions between components. The objective of this study was to determine the effect of mono‐diglycerides (MDG) on the supramolecular structure and interactions, physical stability, and mechanical properties of a rice bran wax–gelatin bigels. The organogel‐to‐hydrogel (OG:HG) ratios tested were 60:40, 70:30, and 80:20 with MDG incorporated at four concentrations (0.5%, 1%, 2%, 3% [w/w]). Bigels were analyzed using nuclear magnetic resonance spectroscopy, confocal scanning laser microscopy (CSLM), Fourier transform infrared spectroscopy (FTIR), texture analysis, and liquid binding capacity studies. The results showed that MDG have a dual effect on the structural organization and stability of the systems; they act as emulsifiers and/or crystallization modifiers. CSLM and FTIR showed that the addition of MDG had the greatest effect on the microstructure of the 60:40 OG:HG ratio, where MDG concentrations 0.5% and 1% (w/w) exhibited a reduction in the size of the oleogel regions while concentrations 2% and 3% (w/w) showed a phase inversion. MDG addition resulted in a gradual decrease in bigel hardness, but an enhancement of physical stability.

IDH1 p.R132H ctDNA and D-2-hydroxyglutarate as CSF biomarkers in patients with IDH-mutant gliomas.

We aimed to evaluate IDH1 p.R132H mutation and 2-hydroxyglutarate (2HG) in cerebrospinal fluid (CSF) as biomarkers for patients with IDH-mutant gliomas. CSF was collected from patients with infiltrating glioma, and 2HG levels were measured by liquid chromatography-mass spectrometry. IDH1 p.R132H mutant allele frequency (MAF) in CSF-ctDNA was measured by digital droplet PCR (ddPCR). Tumor volume was measured from standard-of-care magnetic resonance images. The study included 48 patients, 6 with IDH-mutant and 42 with IDH-wildtype gliomas, and 57 samples, 9 from the patients with IDH-mutant and 48 from the patients with IDH-wildtype gliomas. ctDNA was detected in 7 of the 9 samples from patients with IDH-mutant glioma, and IDH1 p.R132H mutation was detected in 5 of the 7 samples. The MAF ranged from 0.3 to 39.95%. Total 2HG level, D-2HG level, and D/L-2HG ratio in CSF were significantly higher in patients with IDH-mutant gliomas than in patients with IDH-wildtype gliomas. D-2HG level and D/L-2HG ratio correlated with total tumor volume in patients with IDH-mutant gliomas but not in patients with IDH-wildtype gliomas. Our results suggest that detection of IDH1 p.R132H mutation by ddPCR and increased D-2HG level in CSF may help identify IDH-mutant gliomas. Our results also suggest that D-2HG level and D/L-2HG ratio correlate with tumor volume in patients with IDH-mutant gliomas. Further prospective studies with larger cohorts are needed to validate these findings.

Birds of different feeding habits as biomonitors for trace elements in a wetland of the Central Asian Flyway, Sri Lanka

Monitoring the environmental exposure of wildlife to toxic trace elements is important for conservation. Sri Lanka does not have a biomonitoring programme for exposure of wildlife to pollutants. We measured levels of Hg, Pb, Cd, As, and Se in feathers of resident and migratory birds with different food habits in a wetland ecosystem of Sri Lanka, which is located at the southern-most point of the Central Asian Flyway. Diet and migratory status significantly affected concentrations of Hg, Pb, and As. Migrant invertivores showed the highest concentration of Hg and As. The highest concentration of Pb was in resident frugivores. Diet was the only significant explanatory variable for Cd, with frugivores recording the highest concentrations. Migratory status was the only factor significantly affecting feather Se, with migrant birds recording higher levels of Se; however, migratory status did not affect the Se: Hg ratio. The mean Se: Hg ratio was significantly affected by diet, but was >1 in birds of all food habits. Some birds in our study had concentrations of Hg, Pb, and Cd at higher levels than thresholds for adverse effects. High levels of these elements were recorded in both resident and migratory birds of differing food habits. Our study highlights the necessity of including biomonitors from diverse habitats and foraging guilds. This study establishes the baseline information for exposure of wildlife to several toxic trace elements necessary to establish a long-term biomonitoring programme important for the conservation of birds both in a national and global context.

Mercury, selenium, and fatty acids in the axial muscle of largemouth bass: evaluating the influence of seasonal and sexual changes in fish condition and reproductive status.

Largemouth bass (LMB, 265-475 mm) were collected to document whether changes in fish condition and reproductive status influenced the concentration of total mercury (Hg) and selenium (Se) in axial muscle by season and sex. The fatty acid (FA) composition of fish was also examined to describe seasonal and sexual differences and identify whether arachidonic acid (ARA) could be used as a biomarker of Hg toxicity. There was a trend for females to have lower (p < 0.062) Se concentrations than males. The concentration of Se for females during spring (mean ± SD, 686 ± 51 ng/g dw) was 15% lower than males (806 ± 67 ng/g dw). Lower Se concentrations in females than males continued through summer and fall. Concentration of Hg for females during spring (152 ± 39 ng/g ww) was also 59% lower than males (373 ± 303 ng/g ww), but the difference was not significant (p > 0.2). The percent of lipids was greatest in fall and winter (3%) and comprised primarily of omega-3 fatty acids (35 g/100 g lipid). Fish condition as measured by percent lipids and relative weight was negatively (p < 0.02) related to Hg concentration for females and males. Lipid content for both sexes was also positively (p < 0.05) related to the Se:Hg ratio. Relative weight was positively related to the Se:Hg ratio for females during all seasons (p = 0.014), but only during spring and summer for males (p < 0.007). A low Se:Hg value was associated with an elevation in ARA for both sexes and a reduced hepatosomatic index in males. Data suggested that females transferred muscle stores of Se and Hg to developing oocytes during spring. This study generates hypotheses regarding the physiological drivers of seasonal and sexual variability in Hg, Se, and FA in LMB that may be applicable to other species and have implications for fisheries health and management.

Concentration of Selenium and Mercury in six species of fishes from Shatt Al-Arab River, Iraq

The present study deal with determination of Se:Hg ratio in six fish species collected from Shatt Al-Arab river during the period June 2010 to Augest 2010. Muscles of the most important six commercial species of fish C. Carpio, B. luteus, L. abu, T. zilli, B. sharpeyi and T. ilisha have been analyzed after wet digestion with a mixture of concentrated acids (HClO4 / HNO3).The obtained results show that L. abu species having the highest Se:Hg ratio, while B. luteus species having the lowest Se:Hg ratio. Tissues analysis (skin, gills, kidney, liver, muscles) of B. sharpeyi reveals that skin accumulates the highest Se:Hg ratio levels, while muscles contained the lowest Se:Hg ratio. The values obtained are compared with literature data and selenium contents in fish muscle.

Mass flow, enrichment and potential environmental impacts of mercury in a preheater-precalciner cement plant using multiple mining and industrial wastes

Cement plants (CPs) are one of the most important anthropogenic sources of mercury (Hg) emissions in China. Over 1000 cement production lines operate in China and use various raw materials; however, little data on Hg emissions is recorded on site. This study investigated a CP in Guizhou Province that uses multiple mining and industrial wastes as part of the circular economy policy. Among the various raw materials, carbide slag had the highest Hg content (2.6 mg/kg) and contributed half of the Hg input. High Hg concentration (27 mg/kg) in the kiln tail dust and a strong Hg enrichment factor (39) was found, which was determined as the ratio of total Hg accumulated within the clinker production process to the daily Hg input from raw materials and fuel. The clinker had negligible Hg (0.001 mg/kg), while the Hg in cement products (0.04 mg/kg) mostly came from additives and retarders. The estimated atmospheric emission factor of Hg from this CP was 161.5 mg Hg/t clinker, which was much higher than those of other CPs in Guizhou that employ low-Hg raw materials. A five-step sequential extraction experiment with kiln tail dust indicates that Hg mainly existed in fraction of F4 (73–96% of the total Hg, possibly as Hg2Cl2) and that some samples had high proportions of water-soluble Hg (up to 21% of the total), which may be easily released into surrounding water bodies and pose high environmental risks. Using low-Hg raw (or alternative raw) materials and conducting proper disposal of kiln tail dust will reduce the environmental risk of Hg from CPs.

Concentrations, leachability, and health risks of mercury in green tea from major production areas in China

Green tea has many health benefits and is the most consumed type in China. However, the heavy metals and contaminants in tea can also pose a great risk to human health. In this study, mercury (Hg) concentration in green tea collected from 11 provinces in China was examined. The leaching characteristics of Hg during brewing and the associated exposure to drinkers were also evaluated. Results indicated a low potential of Hg accumulation in green tea. The Hg content of green tea from Wanshan District, Guizhou Province—which has the largest Hg mine in China and is severely contaminated by Hg—could be limited by controlling the harvest time of tea leaves. The average Hg content of green tea from 43 tea production sites in China was only 6.3 ± 6.4 µg/kg dry weight. The brewing experiments of green tea showed that the leaching ratio of Hg was 22.61 ± 7.58% for 40 min of a single brew, and increased to 32.83 ± 12.37% after four rounds (3 min/ round) of brewing. The leaching of Hg from tea leaves was significantly affected by leaching time, temperature, and solid-liquid ratio but not by water hardness. The risk of Hg exposure from green tea intake was found to be very low, with an average hazard quotient (HQ) value of only 1.82 ± 1.85% for a single brew in 40 min and 2.64 ± 2.68% after four rounds of brewing. However, in some highly contaminated areas, with HQ values as high as 43.12 ± 2.41%, green tea intake may still pose a high risk of Hg exposure, and this risk should not be ignored.

Utilization of desulfurization gypsum potentially impairs the efforts for reducing Hg emissions from coal-fired power plants in China

The thermal instability of most mercury (Hg) species in flue gas desulfurization (FGD) gypsum may lead to the release of large amounts of Hg into the atmosphere. In this study, gypsum samples were collected from 13 major coal-fired power plants (CFPPs) for evaluating the Hg thermal stability within a temperature range of 100–200 °C. Results indicated that the release ratio of Hg from FGD gypsum varied considerably among the CFPPs. Such significant differences were caused by different proportions of the major Hg compounds, especially of HgClx (HgCl2 and Hg2Cl2), in the FGD gypsum samples. The release ratio appeared extremely sensitive to changes in the treatment temperature and duration. Wallboard manufacturing and its use as cement retarder are the leading causes of Hg emission (corresponding to greater than 95% of the total) during FGD gypsum resource utilization. The total average Hg emitted due to FGD gypsum resource utilization in China in 2017 was estimated to be 11.42 tons (ranging between 2.15 and 38.35 tons), which accounted for about 23.8 % (ranging between 4.6 and 79.8%) of the stack Hg emissions from CFPPs in that year. The results of this study indicate that the resource utilization processes of FGD gypsum are important Hg emission sources and that they should be considered with care in future emission control policies.

Mercury in Sediment Core Samples From Deep Siberian Ice-Rich Permafrost

We determine Hg concentrations of various deposits in Siberia’s deep permafrost and link sediment properties and Hg enrichment to establish a first Hg inventory of late Pleistocene permafrost down to a depth of 36 m below surface. As Arctic warming is transforming the ice-rich permafrost of Siberia, sediment is released and increases the flux of particulates to the Arctic shelf seas through thawing coasts, lakeshores, and river floodplains. Heavy metals within soils and sediments are also released and may increasingly enter Arctic waters and the biological food chain. High levels of mercury (Hg) have been reported from shallow soils across the Arctic. Rapid thawing is now mobilizing sediment from deeper strata, but so far little is known about Hg concentrations in deep permafrost. Here, forty-one samples from sediment successions at seven sites and of different states of permafrost degradation on Bykovsky Peninsula (northern Yakutian coast) and in the Yukechi Alas region (Central Yakutia) were analyzed for Hg, total carbon, total nitrogen, and total organic carbon as well as grain-size distribution, bulk density, and mass specific magnetic susceptibility. We show average Hg concentrations of 9.72 ± 9.28 μg kg−1 in the deep sediments, an amount comparable to the few previous Arctic studies existing, and a significant correlation of Hg content with total organic carbon, total nitrogen, grain-size distribution, and mass specific magnetic susceptibility. Hg concentrations are higher in the generally sandier sediments of the Bykovsky Peninsula than in the siltier sediments of the Yukechi Alas. The ratio of Hg to total organic carbon in this study is 2.57 g kg−1, including samples with very low carbon content. We conclude that many deep permafrost sediments, some of which have been frozen for millennia, contain elevated concentrations of Hg and the stock of Hg ready to be released by erosion is of significance for the Arctic ecosystem. The Hg mobilized may accumulate on the way to or in the shallow sea, and where it enters into active biogeochemical cycles of aquatic systems it may concentrate in food webs. Our study highlights the need for better understanding Hg stocks and Hg release from permafrost.

Estimation of Mercury Losses and Gold Production by Artisanal and Small-Scale Gold Mining (ASGM)

Artisanal and small-scale gold mining (ASGM) utilizes mercury (Hg) for the extraction of gold (Au) and is responsible for the largest anthropogenic source of emissions and releases of Hg to the environment. Previous estimates of Hg use in ASGM have varied widely. In this effort, Hg losses in ASGM were derived from the difference between estimates of total Au production and the production reported by conventional gold mining. On the basis of this result, the average ratio of Hg lost to Au produced in ASGM was estimated to be 1.96 in Africa, 4.63 in Latin America, and 1.23 in Asia. The difference among regions can be attributed to the amalgamation procedure used by the miners, in which whole-ore amalgamation is predominant in Latin America and Asia. The obtained estimated ratio of Hglost:Auproduced suggested the possibility to detect either Au or Hg smuggling from one country to another. On the other hand, the importance of considering cyanidation in ASGM was also suggested.Graphical

A Phase Ib Clinical Trial of Metformin and Chloroquine in Patients with IDH1-Mutated Solid Tumors.

Simple SummaryMutations in the isocitrate dehydrogenase 1 (IDH1) gene occur in high-grade chondrosarcoma, high-grade glioma and intrahepatic cholangiocarcinoma. Due to the lack of effective treatment options, these aggressive types of cancer have a dismal outcome. The metabolism of IDH1-mutated cancer cells is reprogrammed in order to produce the oncometabolite D-2-hydroxyglutarate (D-2HG). In this clinical trial, we used the oral antidiabetic drug metformin and the oral antimalarial drug chloroquine to disrupt the vulnerable metabolism of IDH1-mutated solid tumors. We found that the combination regimen of metformin and chloroquine is well tolerated, but the combination did not induce a clinical response in this patient population. Secondly, we confirmed the clinical usefulness of D/L-2HG ratios in serum as a biomarker and the ddPCR-facilitated detection of an IDH1 mutation in circulating DNA from peripheral blood.Background: Mutations in isocitrate dehydrogenase 1 (IDH1) occur in 60% of chondrosarcoma, 80% of WHO grade II-IV glioma and 20% of intrahepatic cholangiocarcinoma. These solid IDH1-mutated tumors produce the oncometabolite D-2-hydroxyglutarate (D-2HG) and are more vulnerable to disruption of their metabolism. Methods: Patients with IDH1-mutated chondrosarcoma, glioma and intrahepatic cholangiocarcinoma received oral combinational treatment with the antidiabetic drug metformin and the antimalarial drug chloroquine. The primary objective was to determine the occurrence of dose-limiting toxicities (DLTs) and the maximum tolerated dose (MTD). Radiological and biochemical tumor responses to metformin and chloroquine were investigated using CT/MRI scans and magnetic resonance spectroscopy (MRS) measurements of D-2HG levels in serum. Results: Seventeen patients received study treatment for a median duration of 43 days (range: 7–74 days). Of twelve evaluable patients, 10 patients discontinued study medication because of progressive disease and two patients due to toxicity. None of the patients experienced a DLT. The MTD was determined to be 1500 mg of metformin two times a day and 200 mg of chloroquine once a day. A serum D/L-2HG ratio of ≥4.5 predicted the presence of an IDH1 mutation with a sensitivity of 90% and a specificity of 100%. By utilization of digital droplet PCR on plasma samples, we were able to detect tumor-specific IDH1 hotspot mutations in circulating tumor DNA (ctDNA) in investigated patients. Conclusion: Treatment of advanced IDH1-mutated solid tumors with metformin and chloroquine was well tolerated but did not induce a clinical response in this phase Ib clinical trial.

Mercury in blood, hair, and feces from subsistence fish-eating riverines of the Madeira River Basin (Western Amazon)

BackgroundThe Madeira River (Amazon Basin) has been impacted by activities related to artisanal and small-scale gold mining (ASGM), deforestation and burning (for timber, agriculture, and hydroelectric dam projects). All these activities contribute to environmental mercury (Hg) release and cycling into the Amazon ecosystem and thus to changing lifestyles. MethodWe assessed exposure to total and MeHg in two small riverine communities of the Madeira River (Amazon): Lago Puruzinho (LP, n = 26 families) and São Sebastião do Tapurú (SST, n = 31 families). Samples of human hair (n = 137), blood (n = 39), and feces (n = 41) were collected from adults and children (0–15 years of age). ResultsIn women of childbearing age from LP village, the mean blood total-Hg (THg) (45.54 ± 24.76 μg.L−1) and MeHg (10.79 ± 4.36 μg.L−1) concentrations were significantly (p = 0.0024; p < 0.0001, respectively) higher than in women from SST village (THg: 25.32 ± 16.75 μg.L−1; MeHg: 2.32 ± 1.56 μg.L−1) village; the trend in hair-Hg persisted but was statistically significant (p < 0.0145) only for THg (LP, 11.34 ± 5.03 μg. g−1; SST, 7.97 ± 3.51 μg. g−1). In women, the median hair:blood ratio of total Hg was 269. In children, the mean hair THg concentrations were 6.07 ± 3.60 μg. g−1 and 6.47 ± 4.16 μg. g−1 in LP and SST; thus, not significantly different (p = 0.8006). There was a significant association (p < 0.001) between hair-Hg concentrations of mothers and their respective children. The excretion of Hg in feces of women (0.52 μg. g−1 dw) was not significantly different from children (0.49 μg. g−1 dw). The only statistically significant correlation between Hg in feces and in hair was found in children, (n = 16, rs = 0.38, p = 0.005). Significant relationship was seen between the levels of THg in blood and hair of women from LP and SST. Based on hair-Hg concentrations, fish consumption rate ranged from 94.5 to 212.3 g.day−1. ConclusionWomen and children excrete THg in feces in comparable concentrations. However, the mean fish consumption rate and blood MeHg are higher in the most remote villagers. Mother`s hair-Hg concentration is a good predictor of children’s hair-Hg.

Distribution of mercury in serum and blood cells and risk of spontaneous preterm birth: A nested case–control study in China

The relationship between maternal mercury (Hg) intake and the risk of spontaneous preterm birth (SPB) remains unclear. We conducted a nested case–control study from a prospective cohort in Shanxi Province, China, to explore their associations. In total, 126 pregnant women with SPB (cases) and 348 controls with term delivery were included. We measured the Hg concentrations in their serum (Hgs) and blood cell (Hgc) fractions and calculated the concentration ratio of Hg in serum to Hg in blood cells (Hgs/c). We found that only the Hgs/c in the case group was slightly higher than that in control group. The OR of Hgs/c associated with SPB risk was 1.57 [95%CI: 0.99–2.46] with adjusting confounders. After stratification by sampling time, the association above was only statistically significant in the first trimester. High Hgs/c may increase the risk of SPB in the first trimester among women with relatively low Hg exposure.

Study of the Effect of Chemical Pollution with Coal-Fired Power Plant on the Fish of Lake Kenon (Trans-Baikal Territory, Russia)

Abstract In this study, contamination of potentially toxic elements (Cr, Mn, Cu, Zn, Hg and Pb) and species dominant in the fish community of Lake Kenon – Carassius auratus gibelio (Bloch 1782) and Perca fluviatilis (Linnaeus 1758) – were investigated. Chemical elements in samples were determined by atomic emission spectrometry (iCAP-6500, Thermo Scientific, USA) and mass spectrometry (X-7, Thermo Elemental, USA). It was reported that water in Lake Kenon contained low concentrations of the studied metals. The bottom sediments are enriched with Mn, Zn, Hg and Pb. Bioaccumulation factors of chemical elements accumulated from the surrounding water for P. fluviatus and C. auratus gibelio in descending order are as follows: Zn &gt; Pb &gt; Hg &gt; Cu. P. fluviatus accumulates Hg in equal measure from both water and bottom sediments. Manganese and mercury are accumulated in the muscles of C. auratus gibelio from bottom sediments. The high accumulation ratio of Zn and Hg in C. auratus gibelio was obtained from Chara sp. (24 times) and Chironomus spp. (38 times), respectively. High accumulation ratio of Zn (26 times) and Hg (29 times) in P. fluviatus was obtained from amphipods. At the same time, Hg in P. fluviatus muscles was accumulated at high level from Chironomus spp. (67 times). In this way, management decisions for mitigation practices in Lake Kenon should be focussed on for the disposal of wastewater from the ash dump contaminated with chemical elements.