107 research outputs found
Body weight estimation of Bovidae and Plio-Pleistocene faunal change, Turkana Basin, Kenya
Plio-Pleistocene mammalian faunal evolution has been causally linked to global climate change. This study investigates the extent to which climate affected the faunal representation of large mammals in the fossil assemblages from the Turkana Basin, in East Africa during the Plio-Pleistocene. The research project involved the collection and study of both modem and fossil specimens Relative abundances of fossil mammalian families and the Bovidae are explored. To interpret climatically driven faunal change, comparisons are made with fossil faunas from the Nachukui, Shungura and Koobi Fora Formations. The combined relative abundances of bovid tribes through time are used to infer changes in habitat representation. The reduncines, wet habitats indicators, are abundant around 2.5 ma in contrast to the Shungura Formation represented by closed-dry habitats. This suggests that local rather than global scale climatic influences are affecting habitat representation. At 1.7 ma the inferred habitat in the Nachukui Formation shows similarity with more distant localities, namely the Olduvai Basin in Tanzania, where more arid and open environments become increasingly dominant. In a second part of this study, data were collected from modem antelope remains to develop new body weight estimation equations, essential for the estimation of body weights of fossil antelopes from the Nachukui Formation assemblage. Dental remains are less accurate estimators of body weight than are postcranial remains. The body weight estimation equations developed in this study are more accurate than published estimation equations when compared. The body weights of Nachukui Formation fossil bovids were estimated using the equations developed in this study. Variation in body weight representation of bovid tribes through time, in the context of changing habitats, and the use of bovid body weights in taxonomic identification of isolated teeth are explored for the Nachukui Formation
Mucosal Expression of T Cell Gene Variants Is Associated with Differential Resistance to Teladorsagia circumcincta
Resistance of sheep to the gastrointestinal nematode Teladorsagia circumcincta is a heritable characteristic. Control of parasite colonization and egg production is strongly linked to IgA antibody levels regulated by Th2 T cell activation within lymphoid tissue; and persistently-infected susceptible animals develop an inflammatory Th1/Th17 response within the abomasum that fails to control infection. Differential T cell polarization therefore is associated with parasite resistance and/or susceptibility and is controlled by a specific set of transcription factors and cytokine receptors. Transcript variants of these genes have been characterized in sheep, while in humans and mice different variants of the genes are associated with inflammatory diseases. RT-qPCR was used to quantify mucosal expression of the transcript variants of the sheep genes in trickle-infected animals with defined phenotypic traits. Genes that encode full-length GATA3 and IL17RB were shown to be significantly increased in resistant sheep that had controlled parasite infection. Expression levels of both were significantly negatively correlated with abomasal worm count (a parameter of susceptibility) and positively correlated with body weight (a parameter of resistance). These data show that polarized Th2 T cells within the abomasal mucosa play an important role in the maintenance of resistance
Investigating differential T cell polarization in the two pathological forms of sheep paratuberculosis
Paratuberculosis is a chronic enteropathy of ruminants that presents as two
distinct disease forms in sheep; paucibacillary (or tuberculoid) and
multibacillary (or lepromatous) disease. The immunopathology of
paucibacillary and multibacillary sheep paratuberculosis has been linked to
inflammatory Th1/Th17 cell and Th2/macrophage responses respectively.
IL23 and IL25 are key to the development of these responses by interaction
with their complex receptors, IL23R/IL12RB1 and IL17RA/IL17RB.
Furthermore, the polarization of T cells and the development of appropriate
immune responses is controlled by the master regulator transcription factor;
T-bet, GATA3, RORγt and RORα. In humans, variations in the structure,
sequence and/or expression of the genes encoding these proteins have been
implicated in the different pathological forms of tuberculosis and leprosy, and
gastrointestinal inflammatory disorders such as Crohn’s disease. In the
current study, sequencing has identified multiple transcript variants of sheep
IL23R, IL12RB1 and IL17RB and a single IL17RA transcript. RT-qPCR
assays were developed for the cytokine receptor variants identified in this
study and known transcript variants of the transcription factor genes.
Expression levels were compared in the ileo cecal lymph node of
paucibacillary or multibacillary paratuberculosis diseased sheep. Of the
cytokine receptors; the IL12RB1v3 variant, which lacks the receptor
activation motif, was differentially expressed and was significantly increased
in multibacillary disease; this may contribute to high Th2 responses. Full
length IL17RB was differentially expressed and was significantly increased in
multibacillary pathology, which may also contribute to Th2 polarization.
IL17RA was significantly increased in paucibacillary disease. The contrast
between the IL17RA and IL17RB results may indicate that, in addition to Th1
cells, Th17 T cells are also involved in paucibacillary pathology. Of the
transcription factor transcripts; full length TBX21 (T-bet) was differentially
expressed and was significantly increased in paucibacillary disease; this may
explain increased Th1 responses in these sheep. Full length GATA3 was
significantly increased in paucibacillary compared to multibacillary sheep,
suggesting a loss of Th2 responses in late-stage multibacillary pathology.
RORAv1 variant was differentially expressed and was significantly increased
in paucibacillary pathology, indicating a role of Th17 T cells in paucibacillary
pathology
Proteomic and Glucosinolate Profiling of Rapeseed Isolates from Meals Produced by Different Oil Extraction Processes
Acknowledgment This work is part of the Strategic Research 2011–2016 and is funded by the Scottish Government's Rural and Environment Science and Analytical Services Division (RESAS).Peer reviewedPostprin
Validity of the new lifestyles NL-1000 accelerometer for measuring time spent in moderate-to-vigorous physical activity in school settings
Current interest in promoting physical activity in the school environment necessitates an inexpensive, accurate method of measuring physical activity in such settings. Additionally, it is recognized that physical activity must be of at least moderate intensity in order to yield substantial health benefits. The purpose of the study, therefore, was to determine the validity of the New Lifestyles NL-1000 (New Lifestyles, Inc., Lee's Summit, Missouri, USA) accelerometer for measuring moderate-to-vigorous physical activity in school settings, using the Actigraph GT1M (ActiGraph, Pensacola, Florida, USA) as the criterion. Data were collected during a cross-country run (n = 12), physical education (n = 18), and classroom-based physical activities (n = 42). Significant and meaningful intraclass correlations between methods were found, and NL-1000 estimates of moderate-to-vigorous physical activity were not meaningfully different from GT1M-estimated moderate- to-vigorous physical activity. The NL-1000 therefore shows promising validity evidence as an inexpensive, convenient method of measuring moderate-to-vigorous physical activity in school settings
Nutritional B vitamin deficiency alters the expression of key proteins associated with vascular smooth muscle cell proliferation and migration in the aorta of atherosclerotic apolipoprotein E null mice.
Low B vitamin status is linked with human vascular disease. We employed a proteomic and biochemical approach to determine whether nutritional folate deficiency and/or hyperhomocysteinemia altered metabolic processes linked with atherosclerosis in ApoE null mice. Animals were fed either a control fat (C; 4 % w/w lard) or a high-fat [HF; 21 % w/w lard and cholesterol (0/15 % w/w)] diet with different B vitamin compositions for 16 weeks. Aorta tissue was prepared and global protein expression, B vitamin, homocysteine and lipoprotein status measured. Changes in the expression of aorta proteins were detected in response to multiple B vitamin deficiency combined with a high-fat diet (P < 0.05) and were strongly linked with lipoprotein concentrations measured directly in the aorta adventitia (P < 0.001). Pathway analysis revealed treatment effects in the aorta-related primarily to cytoskeletal organisation, smooth muscle cell adhesion and invasiveness (e.g., fibrinogen, moesin, transgelin, vimentin). Combined B vitamin deficiency induced striking quantitative changes in the expression of aorta proteins in atherosclerotic ApoE null mice. Deregulated expression of these proteins is associated with human atherosclerosis. Cellular pathways altered by B vitamin status included cytoskeletal organisation, cell differentiation and migration, oxidative stress and chronic inflammation. These findings provide new insight into the molecular mechanisms through which B vitamin deficiency may accelerate atherosclerosis
Risk and protective factors for self-harm and suicide in children and adolescents: a systematic review and meta-analysis protocol.
INTRODUCTION
Self-harm and suicide are major public health concerns among children and adolescents. Many risk and protective factors for suicide and self-harm have been identified and reported in the literature. However, the capacity of these identified risk and protective factors to guide assessment and management is limited due to their great number. This protocol describes an ongoing systematic review and meta-analysis which aims to examine longitudinal studies of risk factors for self-harm and suicide in children and adolescents, to provide a comparison of the strengths of association of the various risk factors for self-harm and suicide and to shed light on those that require further investigation.
METHODS AND ANALYSIS
We perform a systematic search of the literature using the databases EMBASE, PsycINFO, Medline, CINAHL and HMIC from inception up to 28 October 2020, and the search will be updated before the systematic review publication. Additionally, we will contact experts in the field, including principal investigators whose peer-reviewed publications are included in our systematic review as well as investigators from our extensive research network, and we will search the reference lists of relevant reviews to retrieve any articles that were not identified in our search. We will extract relevant data and present a narrative synthesis and combine the results in meta-analyses where there are sufficient data. We will assess the risk of bias for each study using the Newcastle-Ottawa Scale and present a summary of the quantity and the quality of the evidence for each risk or protective factor.
ETHICS AND DISSEMINATION
Ethical approval will not be sought as this is a systematic review of the literature. Results will be published in mental health journals and presented at conferences focused on suicide prevention.
PROSPERO REGISTRATION NUMBER
CRD42021228212
A candidate gene approach to study nematode resistance traits in naturally infected sheep
Sheep naturally acquire a degree of resistant immunity to parasitic worm infection through repeated exposure. However, the immune response and clinical outcome vary greatly between animals. Genetic polymorphisms in genes integral to differential T helper cell polarization may contribute to variation in host response and disease outcome. A total of twelve single nucleotide polymorphisms (SNPs) were sequenced in IL23R, RORC2 and TBX21 from genomic DNA of Scottish Blackface lambs. Of the twelve SNPs, six were non-synonymous (missense), four were within the 3′ UTRs and two were intronic. The association between nine of these SNPs and the traits of body weight, faecal egg count (FEC) and relative T. circumcincta L3-specific IgA antibody levels was assessed in a population of domestic Scottish Blackface ewe lambs and a population of free-living Soay ewe lambs both naturally infected with a mixture of nematodes. There were no significant associations identified between any of the SNPs and phenotypes recorded in either of the populations after adjustment for multiple testing (Bonferroni corrected P value ≤ 0.002). In the Blackface lambs, there was a nominally significant association (P = 0.007) between IL23Rp.V324M and weight at 20 weeks. This association may be worthy of further investigation in a larger sample of sheep
Vitamin D3 and calcium carbonate supplementation for adolescents with HIV to reduce musculoskeletal morbidity and immunopathology (VITALITY trial): study protocol for a randomised placebo-controlled trial.
BACKGROUND: Of the 2 million children living with HIV globally, 90% live in sub-Saharan Africa. Despite antiretroviral therapy, longstanding HIV infection is associated with several chronic complications in children including growth failure, particularly stunting and delayed puberty. Vitamin D deficiency, which is highly prevalent among children living with HIV in sub-Saharan Africa, has a further adverse impact on bone health. This trial aims to establish whether supplementation with vitamin D3 and calcium carbonate improves musculoskeletal health among peripubertal children living with HIV. METHODS/DESIGN: We will conduct an individually randomised, double-blinded, placebo-controlled trial of weekly high-dose vitamin D3 (20,000 IU) plus daily calcium carbonate (500mg) supplementation for 48 weeks. Eight hundred and forty children living with HIV aged 11-19 years taking ART for ≥6 months will be enrolled and followed up for 96 weeks. The primary outcome is total body less-head bone mineral content for lean mass adjusted for height (TBLH-BMCLBM) Z-score at 48 weeks, measured by dual-energy X-ray absorptiometry (DEXA). Secondary outcomes are DEXA-measured lumbar spine bone mineral apparent density Z-score, number of respiratory infections, lean muscle mass and grip strength at 48 and 96 weeks and TBLH-BMCLBM Z-scores at 96 weeks. Sub-studies will investigate the effect of the intervention on vitamin D3 pathway metabolites and markers of bone turnover, intestinal microbiota, and innate and acquired immune function. DISCUSSION: This is the largest trial to date of vitamin D supplementation in children living with HIV. Intervening to address deficits in bone accrual in childhood is critical for optimising adolescent and early adult bone health and prevention of later adult osteoporotic fractures. Trial results will draw attention to the need to screen for and treat long-term comorbidities in children living with HIV in resource-limited settings. TRIAL REGISTRATION: Pan African Clinical Trials Registry PACTR20200989766029 . Registered on 3 September 2020
Seven features of safety in maternity units: a framework based on multisite ethnography and stakeholder consultation
Background: Reducing avoidable harm in maternity services is a priority globally. As well as learning from mistakes, it is important to produce rigorous descriptions of ‘what good looks like’. Objective: We aimed to characterise features of safety in maternity units and to generate a plain language framework that could be used to guide learning and improvement. Methods: We conducted a multisite ethnography involving 401 hours of non-participant observations 33 semistructured interviews with staff across six maternity units, and a stakeholder consultation involving 65 semistructured telephone interviews and one focus group. Results: We identified seven features of safety in maternity units and summarised them into a framework, named For Us (For Unit Safety). The features include: (1) commitment to safety and improvement at all levels, with everyone involved; (2) technical competence, supported by formal training and informal learning; (3) teamwork, cooperation and positive working relationships; (4) constant reinforcing of safe, ethical and respectful behaviours; (5) multiple problem-sensing systems, used as basis of action; (6) systems and processes designed for safety, and regularly reviewed and optimised; (7) effective coordination and ability to mobilise quickly. These features appear to have a synergistic character, such that each feature is necessary but not sufficient on its own: the features operate in concert through multiple forms of feedback and amplification. Conclusions: This large qualitative study has enabled the generation of a new plain language framework—For Us—that identifies the behaviours and practices that appear to be features of safe care in hospital-based maternity units
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