159 research outputs found

    A Peroxisomal Acyltransferase in Mouse Identifies a Novel Pathway for Taurine Conjugation of Fatty Acids.

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    A wide variety of endogenous carboxylic acids and xenobiotics are conjugated with amino acids, before excretion in urine or bile. The conjugation of carboxylic acids and bile acids with taurine and glycine has been widely characterized and de-novo synthesized bile acids are conjugated to either glycine or taurine in peroxisomes. Peroxisomes are also involved in the oxidation of several other lipid molecules, such as very long chain acyl-CoAs, branched chain acyl-CoAs and prostaglandins. In this study we have now identified a novel peroxisomal enzyme called acyl-CoA:amino acid N-acyltransferase (ACNAT1). Recombinantly expressed ACNAT1 acts as an acyltransferase that efficiently conjugates very long-chain and long-chain fatty acids to taurine. The enzyme shows no conjugating activity with glycine, showing that it is a specific taurine conjugator. Acnat1 is mainly expressed in liver and kidney and the gene is localized in a gene cluster, together with two further acyltransferases, one of which conjugates bile acids to glycine and taurine. In conclusion, these data describe ACNAT1 as a new acyltransferase, involved in taurine conjugation of fatty acids in peroxisomes, identifying a novel pathway for production of N-acyltaurines as signaling molecules or for excretion of fatty acids

    Multiple generations of antibiotic exposure and isolation influence host fitness and the microbiome in a model zooplankton species

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    Background Chronic antibiotic exposure impacts host health through changes to the microbiome, increasing disease risk and reducing the functional repertoire of community members. The detrimental effects of antibiotic perturbation on microbiome structure and function after one host generation of exposure have been well-studied. However, much less is understood about the multigenerational effects of antibiotic exposure and how the microbiome may recover across host generations. Results In this study, we examined microbiome composition and host fitness across five generations of exposure to a suite of three antibiotics in the model zooplankton host Daphnia magna. By utilizing a split-brood design where half of the offspring from antibiotic-exposed parents were allowed to recover and half were maintained in antibiotics, we aimed to examine recovery and resilience of the microbiome. Unexpectedly, we discovered that experimental isolation of single host individuals across generations also exerted a strong effect on microbiome composition, with composition becoming less diverse over generations regardless of treatment. Simultaneously, Daphnia magna body size and cumulative reproduction increased across generations while survival decreased. Though antibiotics did cause substantial changes to microbiome composition, the microbiome generally became similar to the no antibiotic control treatment within one generation of recovery no matter how many prior generations were spent in antibiotics. Conclusions Contrary to results found in vertebrate systems, Daphnia magna microbiome composition recovers quickly after antibiotic exposure. However, our results suggest that the isolation of individual hosts leads to the stochastic extinction of rare taxa in the microbiome, indicating that these taxa are likely maintained via transmission in host populations rather than intrinsic mechanisms. This may explain the intriguing result that microbiome diversity loss increased host fitness

    The development of visuotactile congruency effects for sequences of events.

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    Abstract Sensitivity to the temporal coherence of visual and tactile signals increases perceptual reliability and is evident during infancy. However, it is not clear how, or whether, bidirectional visuotactile interactions change across childhood. Furthermore, no study has explored whether viewing a body modulates how children perceive visuotactile sequences of events. Here, children aged 5–7 years (n = 19), 8 and 9 years (n = 21), and 10–12 years (n = 24) and adults (n = 20) discriminated the number of target events (one or two) in a task-relevant modality (touch or vision) and ignored distractors (one or two) in the opposing modality. While participants performed the task, an image of either a hand or an object was presented. Children aged 5–7 years and 8 and 9 years showed larger crossmodal interference from visual distractors when discriminating tactile targets than the converse. Across age groups, this was strongest when two visual distractors were presented with one tactile target, implying a "fission-like" crossmodal effect (perceiving one event as two events). There was no influence of visual context (viewing a hand or non-hand image) on visuotactile interactions for any age group. Our results suggest robust interference from discontinuous visual information on tactile discrimination of sequences of events during early and middle childhood. These findings are discussed with respect to age-related changes in sensory dominance, selective attention, and multisensory processing

    Evaluation of a health promotion program in children: Study protocol and design of the cluster-randomized Baden-WĂĽrttemberg primary school study [DRKS-ID: DRKS00000494]

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    <p>Abstract</p> <p>Background</p> <p>Increasing prevalences of overweight and obesity in children are known problems in industrialized countries. Early prevention is important as overweight and obesity persist over time and are related with health problems later in adulthood. "Komm mit in das gesunde Boot - Grundschule" is a school-based program to promote a healthier lifestyle. Main goals of the intervention are to increase physical activity, decrease the consumption of sugar-sweetened beverages, and to decrease time spent sedentary by promoting active choices for healthy lifestyle. The program to date is distributed by 34 project delivery consultants in the state of Baden-WĂĽrttemberg and is currently implemented in 427 primary schools. The efficacy of this large scale intervention is examined via the Baden-WĂĽrttemberg Study.</p> <p>Methods/Design</p> <p>The Baden-WĂĽrttemberg Study is a prospective, stratified, cluster-randomized, and longitudinal study with two groups (intervention group and control group). Measurements were taken at the beginning of the academic years 2010/2011 and 2011/2012. Efficacy of the intervention is being assessed using three main outcomes: changes in waist circumference, skinfold thickness and 6 minutes run. Stratified cluster-randomization (according to class grade level) was performed for primary schools; pupils, teachers/principals, and parents were investigated. An approximately balanced number of classes in intervention group and control group could be reached by stratified randomization and was maintained at follow-up.</p> <p>Discussion</p> <p>At present, "Komm mit in das Gesunde Boot - Grundschule" is the largest school-based health promotion program in Germany. Comparative objective main outcomes are used for the evaluation of efficacy. Simulations showed sufficient power with the existing sample size. Therefore, the results will show whether the promotion of a healthier lifestyle in primary school children is possible using a relatively low effort within a school-based program involving children, teachers and parents. The research team anticipates that not only efficacy will be proven in this study but also expects many other positive effects of the program.</p> <p>Trial registration</p> <p>German Clinical Trials Register (DRKS), DRKS-ID: DRKS00000494</p

    Diet and food strategies in a southern al-Andalusian urban environment during Caliphal period, ecija, Sevilla

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    The Iberian medieval period is unique in European history due to the widespread socio-cultural changes that took place after the arrival of Arabs, Berbers and Islam in 711 AD. Recently, isotopic research has been insightful on dietary shifts, status, resource availability and the impact of environment. However, there is no published isotopic research exploring these factors in southern Iberian populations, and as the history of this area differs to the northern regions, this leaves a significant lacuna in our knowledge. This research fills this gap via isotopic analysis of human (n = 66) and faunal (n = 13) samples from the 9th to the 13th century Écija, a town renowned for high temperatures and salinity. Stable carbon (δ13C) and nitrogen (δ15N) isotopes were assessed from rib collagen, while carbon (δ13C) values were derived from enamel apatite. Human diet is consistent with C3 plant consumption with a very minor contribution of C4 plants, an interesting feature considering the suitability of Écija to C4 cereal production. δ15N values vary among adults, which may suggest variable animal protein consumption or isotopic variation within animal species due to differences in foddering. Consideration of δ13C collagen and apatite values together may indicate sugarcane consumption, while moderate δ15N values do not suggest a strong aridity or salinity effect. Comparison with other Iberian groups shows similarities relating to time and location rather than by religion, although more multi-isotopic studies combined with zooarchaeology and botany may reveal subtle differences unobservable in carbon and nitrogen collagen studies alone.OLC is funded by Plan Galego I2C mod.B (ED481D 2017/014). The research was partially funded by the projects “Galician Paleodiet” and by Consiliencia network (ED 431D2017/08) Xunta de GaliciaS

    Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanoparticles

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    We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles

    Genome-wide association meta-analyses and fine-mapping elucidate pathways influencing albuminuria

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    Abstract: Increased levels of the urinary albumin-to-creatinine ratio (UACR) are associated with higher risk of kidney disease progression and cardiovascular events, but underlying mechanisms are incompletely understood. Here, we conduct trans-ethnic (n = 564,257) and European-ancestry specific meta-analyses of genome-wide association studies of UACR, including ancestry- and diabetes-specific analyses, and identify 68 UACR-associated loci. Genetic correlation analyses and risk score associations in an independent electronic medical records database (n = 192,868) reveal connections with proteinuria, hyperlipidemia, gout, and hypertension. Fine-mapping and trans-Omics analyses with gene expression in 47 tissues and plasma protein levels implicate genes potentially operating through differential expression in kidney (including TGFB1, MUC1, PRKCI, and OAF), and allow coupling of UACR associations to altered plasma OAF concentrations. Knockdown of OAF and PRKCI orthologs in Drosophila nephrocytes reduces albumin endocytosis. Silencing fly PRKCI further impairs slit diaphragm formation. These results generate a priority list of genes and pathways for translational research to reduce albuminuria

    Loci influencing blood pressure identified using a cardiovascular gene-centric array

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    Blood pressure (BP) is a heritable determinant of risk for cardiovascular disease (CVD). To investigate genetic associations with systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP) and pulse pressure (PP), we genotyped 50 000 single-nucleotide polymorphisms (SNPs) that capture variation in 2100 candidate genes for cardiovascular phenotypes in 61 619 individuals of European ancestry from cohort studies in the USA and Europe. We identified novel associations between rs347591 and SBP (chromosome 3p25.3, in an intron of HRH1) and between rs2169137 and DBP (chromosome1q32.1 in an intron of MDM4) and between rs2014408 and SBP (chromosome 11p15 in an intron of SOX6), previously reported to be associated with MAP. We also confirmed 10 previously known loci associated with SBP, DBP, MAP or PP (ADRB1, ATP2B1, SH2B3/ATXN2, CSK, CYP17A1, FURIN, HFE, LSP1, MTHFR, SOX6) at array-wide significance (P 2.4 10(6)). We then replicated these associations in an independent set of 65 886 individuals of European ancestry. The findings from expression QTL (eQTL) analysis showed associations of SNPs in the MDM4 region with MDM4 expression. We did not find any evidence of association of the two novel SNPs in MDM4 and HRH1 with sequelae of high BP including coronary artery disease (CAD), left ventricular hypertrophy (LVH) or stroke. In summary, we identified two novel loci associated with BP and confirmed multiple previously reported associations. Our findings extend our understanding of genes involved in BP regulation, some of which may eventually provide new targets for therapeutic intervention.</p
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