62 research outputs found

    FH phenotype: monogenic, polygenic and other causes

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    Familial Hypercholesterolaemia (FH) is a monogenic disorder characterised by high LDL-C concentrations and increased cardiovascular risk. However, in clinically defined FH cohorts worldwide, an FH-causing variant is only found in 40-50% of the cases. The aim of this work was to characterise the genetic cause of the FH phenotype in Portuguese clinical FH patients. Methods and Results Between 1999 and 2017, 731 index patients (311 children and 420 adults) who met the Simon Broome diagnostic criteria had been referred to our laboratory. LDLR, APOB, PCSK9, APOE, LIPA, LDLRAP1, ABCG5/8 genes were analysed by PCR amplification and Sanger sequencing. The 6-SNP LDL-C genetic risk score (GRS) for polygenic hypercholesterolaemia was validated in the Portuguese population and cases with a GRS over the 25th percentile were considered to have a high likelihood of polygenic hypercholesterolaemia. An FH-causing mutation was found in 39% of patients (94% in LDLR, 5% APOB and 1% PCSK9), while at least 29% have polygenic hypercholesterolaemia and 1% have other lipid disorders. A genetic cause for the FH phenotype was found in 503 patients (69%). All known causes of the FH phenotype should be investigated in FH cohorts to ensure accurate diagnosis and appropriate management.Cibelle Mariano was supported by a PhD student grant [SFRH/BD/52494/2014]. Marta Futema is supported by the Fondation Leducq Transatlantic Networks of Excellence Program grant (no 14 CVD03). The work of Marilia Antunes is partially funded by UID/MAT/000016/2019. SEH acknowledges funding from the British Heart Foundation grant (BHF PG08/008) and from the NIHR UCLH BRC. MB acknowledges funding from Science and Technology Foundation (PIC/IC/83020/2007) (PIC/IC/83333/2007) for the e_COR and Portuguese FH Study and from Portuguese Cardiology Society for the Portuguese FH Study.info:eu-repo/semantics/publishedVersio

    Imaging assessment of children presenting with suspected or known juvenile idiopathic arthritis : ESSR-ESPR points to consider

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    Juvenile idiopathic arthritis (JIA) is the most common paediatric rheumatic disease. It represents a group of heterogenous inflammatory disorders with unknown origin and is a diagnosis of exclusion in which imaging plays an important role. JIA is defined as arthritis of one or more joints that begins before the age of 16 years, persists for more than 6 weeks and is of unknown aetiology and pathophysiology. The clinical goal is early suppression of inflammation to prevent irreversible joint damage which has shifted the emphasis from detecting established joint damage to proactively detecting inflammatory change. This drives the need for imaging techniques that are more sensitive than conventional radiography in the evaluation of inflammatory processes as well as early osteochondral change. Physical examination has limited reliability, even if performed by an experienced clinician, emphasising the importance of imaging to aid in clinical decision-making. On behalf of the European Society of Musculoskeletal Radiology (ESSR) arthritis subcommittee and the European Society of Paediatric Radiology (ESPR) musculoskeletal imaging taskforce, based on literature review and/or expert opinion, we discuss paediatric-specific imaging characteristics of the most commonly involved, in literature best documented and clinically important joints in JIA, namely the temporomandibular joints (TMJs), spine, sacroiliac (SI) joints, wrists, hips and knees, followed by a clinically applicable point to consider for each joint. We will also touch upon controversies in the current literature that remain to be resolved with ongoing research

    Identification of a novel proinsulin-associated SNP and demonstration that proinsulin is unlikely to be a causal factor in subclinical vascular remodelling using Mendelian randomisation

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    Background and aims Increased proinsulin relative to insulin levels have been associated with subclinical atherosclerosis (measured by carotid intima-media thickness (cIMT)) and are predictive of future cardiovascular disease (CVD), independently of established risk factors. The mechanisms linking proinsulin to atherosclerosis and CVD are unclear. A genome-wide meta-analysis has identified nine loci associated with circulating proinsulin levels. Using proinsulin-associated SNPs, we set out to use a Mendelian randomisation approach to test the hypothesis that proinsulin plays a causal role in subclinical vascular remodelling. Methods We studied the high CVD-risk IMPROVE cohort (n = 3345), which has detailed biochemical phenotyping and repeated, state-of-the-art, high-resolution carotid ultrasound examinations. Genotyping was performed using Illumina Cardio-Metabo and Immuno arrays, which include reported proinsulin-associated loci. Participants with type 2 diabetes (n = 904) were omitted from the analysis. Linear regression was used to identify proinsulin-associated genetic variants. Results We identified a proinsulin locus on chromosome 15 (rs8029765) and replicated it in data from 20,003 additional individuals. An 11-SNP score, including the previously identified and the chromosome 15 proinsulin-associated loci, was significantly and negatively associated with baseline IMTmean and IMTmax (the primary cIMT phenotypes) but not with progression measures. However, MR-Eggers refuted any significant effect of the proinsulin-associated 11-SNP score, and a non-pleiotropic SNP score of three variants (including rs8029765) demonstrated no effect on baseline or progression cIMT measures. Conclusions We identified a novel proinsulin-associated locus and demonstrated that whilst proinsulin levels are associated with cIMT measures, proinsulin per se is unlikely to have a causative effect on cIMT

    Diving into the vertical dimension of elasmobranch movement ecology

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    Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements

    Application of a Poisson distribution quality control measure to the analysis of two human hookworm drug treatment studies in Ghana

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    We examined faecal egg count reduction tests (FECRTs) conducted with hookworm-infected humans in Ghana in 2007 (study 1) and 2010 (study 2) in order to explore aspects of the test analysis. Some subjects showed increased FEC following drug treatment. This occurred mostly in <150. epg pre-treatment FEC subjects. We sought a means to remove 'erroneous' negative drug efficacy cases from the FECRT analysis. Pre- and post-treatment FECs from negative drug efficacy cases were examined to determine whether they represented replicates from a single randomly distributed sample, that is, if they were consistent with a Poisson distribution. Cases where the post-treatment FEC was greater than that expected if it and the pre-treatment sample had been taken from a single random distribution of eggs were excluded from the FECRT. We suggest that these cases most likely represent non-random distribution of eggs in stools, day-to-day variations in egg excretion, or worm patency onset after drug treatment, and hence are not accurate measurements of drug efficacy. This led to exclusion of the most extreme negative drug efficacy cases, with significant increases in overall drug efficacy for study 1 (81.6% vs 89.2%) and study 2 (86.7% vs 89.4%). Excluding FEC <150 individuals from the analysis also increased the study 1 efficacy (81.6% vs 88.9%), however, this resulted in the exclusion of 45% of the study subjects, compared to the exclusion of just 5% using the Poisson distribution method. While low FEC subjects are excluded from livestock FECRTs, the significant prevalence of such subjects in human FECRTs suggests that their exclusion may not be practical. Hence, we suggest that the influence of low FECs can be minimised by excluding 'erroneous' negative efficacy cases using a simple Poisson distribution analysis

    Continuous removal of Cr(VI) from aqueous solution catalysed by palladised biomass of <i>Desulfovibrio vulgaris</i>

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    Growth-decoupled cells of Desulfovibrio vulgaris NCIMB 8303 can be used to reduce Pd(II) to cell-bound Pd(0) (Bio-Pd0), a bioinorganic catalyst capable of reducing hexavalent chromium to less toxic Cr(III), using formate as the electron donor. Magnetic resonance imaging showed that Bio-Pd0, immobilized in chitosan and agar beads, is distinguishable from the surrounding gel and is evenly dispersed within the immobilization matrix. Agar-immobilized Bio-Pd0 and `chemical Pd0' were packed into continuous-flow reactors, and challenged with a solution containing 100 μm Cr(VI) (pH 7) at a flow rate of 2.4 ml h−1. Agar-immobilized chemical Pd0 columns lost Cr(VI) reducing ability by 160 h, whereas columns containing immobilized Bio-Pd0 maintained 90% reduction until 680 h, after which reduction efficiency was gradually lost

    Reduction of Cr(VI) by immobilized cells of <i>Desulfovibrio vulgaris</i> NCIMB 8303 and <i>Microbacterium</i> sp. NCIMB 13776

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    Hexavalent chromium, a carcinogen and mutagen, can be reduced to Cr(III) by Desulfovibrio vulgaris NCIMB 8303 and Microbacterium sp. NCIMB 13776. This study examined Cr(VI) reduction by immobilized cells of the two strains in a common solution matrix using various entrapment matrices. Chitosan and PVA-borate beads did not retain integrity and supported low or no reduction of Cr(VI) by the cells. A commercial preparation (Lentikats) was stable but also did not support Cr(VI) reduction. K-carrageenan beads were stable in batch suspensions but gel integrity was lost after only 5 h in a flow-through system in the presence of 100 μM Cr(VI). The best immobilization matrices were agar and agarose, where the initial rates of reduction of Cr(VI) (from 500 μM solution) for D. vulgaris NCIMB 8303 and Microbacterium sp. NCIMB 13776 were 127 (agar) and 130 (agarose), and 15 (agar) and 12 (agarose) nmol h−1 mg dry cell wt−1, respectively. The higher removal of Cr(VI) by D. vulgaris was also seen in 14-mL packed-bed flow-through columns, where, at a flow rate of 2.4 mL h−1, the percentage removal of Cr(VI) was ∼95% and 60% for D. vulgaris and Microbacterium sp., respectively (agar-immobilized cells). The Cr(VI) reducing activities of D. vulgaris and Microbacterium sp. were lost after 159 and 140 h, respectively. Examination of the beads for structural integrity within the columns in situ using magnetic resonance imaging after 24 and 100 h of continuous operation against Cr(VI) (with negligible Cr retained within the columns) showed that agar beads were more stable with time. The most appropriate system for development of a continuous bioprocess is thus the use of D. vulgaris NCIMB 8303 immobilized in an agar gel matrix

    The FH phenotype: monogenic familial hypercholesterolaemia, polygenic dyslipidaemia and other causes

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    Familial hypercholesterolaemia (FH) is a monogenic autosomal condition where patients present very high LDL-C values and an increase cardiovascular risk. FH is caused by mutations in 3 genes: LDLR, APOB and PCSK9. However in only about 40%-50% of the cases an FH causing mutation is found. The FH phenotype has been associated recently to other monogenic disorders as lysosomal acid lipase deficiency or can have a polygenic origin. The aim of this work was to characterize the origin of FH phenotype in a cohort of patients with a clinical diagnosis of FH.Cibelle Mariano was funded by SFRH/BD/52494/2014.N/
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