X-ray structure of <i>Fasciola hepatica</i> Sigma class glutathione transferase 1 reveals a disulfide bond to support stability in gastro-intestinal environment

This is the final version. Available on open access from Nature Research via the DOI in this recordData delivery: The structure factors and the refined coordinates of the FhGST-S1 structures have been deposited with the Protein Data Bank and have the access codes 2WB9 and 2WDU.Sigma class GST (Prostaglandin D synthase), FhGST-S1, is present in the excretory–secretory products (ES) of the liver fluke parasite Fasciola hepatica as cargo of extracellular vesicles (EVs) released by the parasite. FhGST-S1 has a well characterised role in the modulation of the immune response; a key fluke intercession that allows for establishment and development within their hosts. We have resolved the three-dimensional structure of FhGST-S1 in complex with its co-factor glutathione, in complex with a glutathione-cysteine adduct, and in a glutathione disulfide complex in order to initiate a research pipeline to mechanistically understand how FhGST-S1 functions within the host environment and to rationally design selective inhibitors. The overall fold of FhGST-S1 shows high structural similarity to other Sigma class GSTs. However, a unique interdomain disulfide bond was found in the FhGST-S1 which could stabilise the structure within the host gastro-intestinal environment. The position of the two domains of the protein with respect to each other is seen to be crucial in the formation of the active site cleft of the enzyme. The interdomain disulfide bond raises the possibility of oxidative regulation of the active site of this GST protein.European Union FP6Biotechnology and Biological Sciences Research Council (BBSRC)NRN WalesUniversity of Exete

Sex Ratio Changes as Sentinel Health Events of Endocrine Disruption

The production and widespread use of synthetic chemicals since the 1940s have resulted in ubiquitous contamination of fish, wildlife and human populations. Since the 1960s, observers have documented major damage to wildlife reproduction across the globe, and subsequently, damage to reproductive health in exposed humans as well. The sex ratio in human communities and populations can be readily measured to ascertain whether reproductive effects, such as subtle birth defects of the reproductive tract caused by exposures to chemicals, might be occurring. Male to femalesex ratios appear to be declining in populations in several parts of the globe, possibly as a result of prenatal exposures to chemicals. Sex ratio data for communitieswith unusual occupational or environmental exposures can be compiled using traditional epidemiological techniques in pursuit of environmental justice. Local, regional and national population health researchers and occupational hygienists can use health statistics toexamine sex ratios as sentinel health events that might portend patterns of subtle structural birth defects of the reproductive tract and functional deficits in neurodevelopment

Towards delineating functions within the fasciola secreted cathepsin L protease family by integrating in vivo based sub-proteomics and phylogenetics

BACKGROUND: Fasciola hepatica, along with Fasciola gigantica, is the causative agent of fasciolosis, a foodborne zoonotic disease affecting grazing animals and humans worldwide. Pathology is directly related to the release of parasite proteins that facilitate establishment within the host. The dominant components of these excretory-secretory (ES) products are also the most promising vaccine candidates, the cathepsin L (Cat L) protease family. METHODOLOGY/PRINCIPAL FINDINGS: The sub-proteome of Cat L proteases from adult F. hepatica ES products derived from in vitro culture and in vivo from ovine host bile were compared by 2-DE. The individual Cat L proteases were identified by tandem mass spectrometry with the support of an in-house translated liver fluke EST database. The study reveals plasticity within the CL1 clade of Cat L proteases; highlighted by the identification of a novel isoform and CL1 sub-clade, resulting in a new Cat L phylogenetic analysis including representatives from other adult Cat L phylogenetic clades. Additionally, for the first time, mass spectrometry was shown to be sufficiently sensitive to reveal single amino acid polymorphisms in a resolved 2-DE protein spot derived from pooled population samples. CONCLUSIONS/SIGNIFICANCE: We have investigated the sub-proteome at the population level of a vaccine target family using the Cat L proteases from F. hepatica as a case study. We have confirmed that F. hepatica exhibits more plasticity in the expression of the secreted CL1 clade of Cat L proteases at the protein level than previously realised. We recommend that superfamily based vaccine discovery programmes should screen parasite populations from different host populations and, if required, different host species via sub-proteomic assay in order to confirm the relative expression at the protein level prior to the vaccine development phase

The significance of motivation in student-centred learning : a reflective case study

The theoretical underpinnings of student-centred learning suggest motivation to be an integral component. However, lack of clarification of what is involved in motivation in education often results in unchallenged assumptions that fail to recognise that what motivates some students may alienate others. This case study, using socio-cognitive motivational theory to analyse previously collected data, derives three fuzzy propositions which, collectively, suggest that motivation interacts with the whole cycle of episodes in the teachinglearning process. It argues that the development of the higherlevel cognitive competencies that are implied by the term, student-centred learning, must integrate motivational constructs such as goal orientation, volition, interest and attributions into pedagogical practices

Outcomes after angiography with sodium bicarbonate and acetylcysteine

Background: Intravenous sodium bicarbonate and oral acetylcysteine are widely used to prevent acute kidney injury and associated adverse outcomes after angiography without definitive evidence of their efficacy. Methods: Using a 2-by-2 factorial design, we randomly assigned 5177 patients at high risk for renal complications who were scheduled for angiography to receive intravenous 1.26% sodium bicarbonate or intravenous 0.9% sodium chloride and 5 days of oral acetylcysteine or oral placebo; of these patients, 4993 were included in the modified intention-to-treat analysis. The primary end point was a composite of death, the need for dialysis, or a persistent increase of at least 50% from baseline in the serum creatinine level at 90 days. Contrast-associated acute kidney injury was a secondary end point. Results: The sponsor stopped the trial after a prespecified interim analysis. There was no interaction between sodium bicarbonate and acetylcysteine with respect to the primary end point (P=0.33). The primary end point occurred in 110 of 2511 patients (4.4%) in the sodium bicarbonate group as compared with 116 of 2482 (4.7%) in the sodium chloride group (odds ratio, 0.93; 95% confidence interval [CI], 0.72 to 1.22; P=0.62) and in 114 of 2495 patients (4.6%) in the acetylcysteine group as compared with 112 of 2498 (4.5%) in the placebo group (odds ratio, 1.02; 95% CI, 0.78 to 1.33; P=0.88). There were no significant between-group differences in the rates of contrast-associated acute kidney injury. Conclusions: Among patients at high risk for renal complications who were undergoing angiography, there was no benefit of intravenous sodium bicarbonate over intravenous sodium chloride or of oral acetylcysteine over placebo for the prevention of death, need for dialysis, or persistent decline in kidney function at 90 days or for the prevention of contrast-associated acute kidney injury. (Funded by the U.S. Department of Veterans Affairs Office of Research and Development and the National Health and Medical Research Council of Australia; PRESERVE ClinicalTrials.gov number, NCT01467466.

Proteomic analysis of embryonic Fasciola hepatica: Characterization and antigenic potential of a developmentally regulated heat shock protein

Fasciola hepatica is responsible for human disease and economic livestock loss on a global scale. We report the first post-genomic investigation of cellular proteins expressed by embryonic F. hepatica via two-dimensional electrophoresis, image analysis and tandem mass spectrometry. Antioxidant proteins and protein chaperones are prominently expressed by embryonic F. hepatica. Molecular differences between the egg and other characterized F. hepatica lifecycle stages were noted. Furthermore, proteins expressed within liver fluke eggs differ to those isolated from the well-characterized eggs of the human blood flatworm Schistosoma mansoni were revealed. Plasticity in expression of major proteins, particularly a prominently expressed 65 kDa protein cluster was seen between natural populations of embryonating F. hepatica eggs suggesting that liver fluke embryogenisis is a plastic process. Immunoblotting revealed that the abundant 65 kDa protein cluster is recognised by infection sera from three F. hepatica challenged host species. Mass spectrometry and BLAST analyses demonstrated that the 65 kDa antigen shows homology to egg antigens of other flatworm parasites, and is represented in a F. hepatica EST database constructed from adult fluke transcripts. EST clones encoding the egg antigen were re-sequenced, predicting two forms of the protein. Four clones predict a 312 aa polypeptide, three clones encode a putative 110 amino acid extension at the N-terminus which may be involved in protein secretion, although this extension was not expressed by natively extracted proteins. Consistent expression of alpha crystallin domains confirmed the protein to be a member of the alpha crystallin containing small heat shock protein (AC/sHSP) superfamily. AC/sHSPs are ubiquitous in nature, however, this is the first time a member of this protein superfamily has been described from F. hepatica. The antigenic AC/sHSP was named Fh-HSP35α based on predictions of molecular weight. Production of recombinant Fh-HSP35α reveals considerable mass discrepancy between native and recombinant proteins, although descriptions of other characterized flatworm AC/sHSPs, suggest that the native form is a dimer. Immunoblot analyses confirm that the recombinant protein is recognised by F. hepatica challenged hosts, but does not react with sera from non-infected animals. We discuss the potential of recombinant Fh-HSP35α as an egg-based diagnostic marker for liver fluke infection

Association Between p.Leu54Met Polymorphism at the Paraoxonase-1 Gene and Plantar Fascia Thickness in Young Subjects With Type 1 Diabetes

OBJECTIVE— In type 1 diabetes, plantar fascia, a collagen-rich tissue, is susceptible to glycation and oxidation. Paraoxonase-1 (PON1) is an HDL-bound antioxidant enzyme. PON1 polymorphisms have been associated with susceptibility to macro- and microvascular complications. We investigated the relationship between plantar fascia thickness (PFT) and PON1 gene variants, p.Leu54Met, p.Gln192Arg, and c.-107C>T, in type 1 diabetes

Active Children Through Individual Vouchers Evaluation: A Mixed-Method RCT

Introduction Physical activity declines in adolescence, especially among those in deprived areas. Research suggests this may result from accessibility barriers (e.g., cost and locality). The Active Children Through Individual Vouchers Evaluation RCT aimed to improve the fitness and heart health of teenagers in Wales with the help of teenagers who co-produced the study. Study design This study was a mixed-method RCT. Setting/participants Before data collection, which took place at baseline, 6 months, and 12 months for both arms, 7 schools were randomized by an external statistician (4 intervention schools, n=524; 3 control schools, n=385). Intervention The Active Children Through Individual Vouchers Evaluation intervention included provision of activity vouchers (£20 per month), a peer mentoring scheme, and support worker engagement for 12 months between January and December 2017. Data analysis occurred February–April 2018. Main outcome measures Data included measures of cardiovascular fitness, cardiovascular health (blood pressure and pulse wave analysis), motivation, and focus groups. Results The intervention showed a trend to improve the distance ran (primary outcome) and was significant in improving the likelihood of intervention teenagers being fit (OR=1.21, 95% CI=1.07, 1.38, p=0.002). There was a reduction in teenagers classified as having high blood pressure (secondary outcome) in the intervention group (baseline, 5.3% [28/524]; 12 months, 2.7% [14/524]). Data on where teenagers used vouchers and evidence from focus groups showed that teenagers wanted to access more unstructured, informal, and social activities in their local areas. Conclusions Active Children Through Individual Vouchers Evaluation identified methods that may have a positive impact on cardiovascular fitness, cardiovascular health, and perspectives of activity. Consulting with teenagers, empowering them, and providing more local opportunities for them to take part in activities that are fun, unstructured, and social could positively impact teenage physical activity

COVID-19 mitigation measures in primary schools and association with infection and school staff wellbeing: An observational survey linked with routine data in Wales, UK

IntroductionSchool-based COVID-19 mitigation strategies have greatly impacted the primary school day (children aged 3–11) including: wearing face coverings, two metre distancing, no mixing of children, and no breakfast clubs or extra-curricular activities. This study examines these mitigation measures and association with COVID-19 infection, respiratory infection, and school staff wellbeing between October to December 2020 in Wales, UK.MethodsA school staff survey captured self-reported COVID-19 mitigation measures in the school, participant anxiety and depression, and open-text responses regarding experiences of teaching and implementing measures. These survey responses were linked to national-scale COVID-19 test results data to examine association of measures in the school and the likelihood of a positive (staff or pupil) COVID-19 case in the school (clustered by school, adjusted for school size and free school meals using logistic regression). Linkage was conducted through the SAIL (Secure Anonymised Information Linkage) Databank.ResultsResponses were obtained from 353 participants from 59 primary schools within 15 of 22 local authorities. Having more direct non-household contacts was associated with a higher likelihood of COVID-19 positive case in the school (1–5 contacts compared to none, OR 2.89 (1.01, 8.31)) and a trend to more self-reported cold symptoms. Staff face covering was not associated with a lower odds of school COVID-19 cases (mask vs. no covering OR 2.82 (1.11, 7.14)) and was associated with higher self-reported cold symptoms. School staff reported the impacts of wearing face coverings on teaching, including having to stand closer to pupils and raise their voices to be heard. 67.1% were not able to implement two metre social distancing from pupils. We did not find evidence that maintaining a two metre distance was associated with lower rates of COVID-19 in the school.ConclusionsImplementing, adhering to and evaluating COVID-19 mitigation guidelines is challenging in primary school settings. Our findings suggest that reducing non-household direct contacts lowers infection rates. There was no evidence that face coverings, two metre social distancing or stopping children mixing was associated with lower odds of COVID-19 or cold infection rates in the school. Primary school staff found teaching challenging during COVID-19 restrictions, especially for younger learners and those with additional learning needs