RVC Repository (Royal Veterinary College)
Not a member yet
10877 research outputs found
Sort by
Bioenergetic Profiling in Zebrafish NCL Models
No full textNeuronal Ceroid Lipofuscinoses (NCLs) are a group of inherited neurodegenerative disorders characterized by autofluorescent lipopigment accumulation. NCLs consist of various types, spanning from CLN1 to CLN14 (except for “CLN9”), each linked to a particular mutated gene. Although the symptoms exhibit resemblances, the age at which each symptom manifests differs across the distinct types. Mitochondrial impairment has been implicated in the pathogenesis of NCLs, with studies suggesting contributions from dysfunctional oxidative phosphorylation and altered mitochondrial membrane potential to the progressive neurodegeneration observed in affected individuals. Utilizing Seahorse XF Analyzer, this study presents a method for the nuanced exploration of mitochondrial function and cellular metabolism, offering insights into potential therapeutic avenues. Zebrafish models reveal phenotypic similarities to human patients, making them promising for disease studies. Our research optimizes the Seahorse Mito Stress assay at 2 days post-fertilization (dpf) in zebrafish. This emerging approach holds great promise for identifying novel therapies
Characterisation of the UK domestic dog (Canis lupus familiaris) population for identification purposes using a forensically validated set of 13 autosomal STR markers
No full textCanine evidence in the UK is currently not being fully investigated, partly due to the lack of comprehensive genetic databases that are able to clarify the complexity of the highly inbred breeds that make up the canine population. The study here proposes the use of the CaDNAP markers, a forensically validated panel, to be applied to the wider UK canine population. For this purpose, over 1200 dogs have been genotyped for 13 STRs, belonging to 80 breeds. Mathematical corrections have been investigated to address the uneven breed distribution in the country in order to produce a more reliable allele frequency database for the whole UK canine population. In addition, a selection of the most common breeds (11) has been further investigated to produce allele frequency databases that are breed-specific with the aim of producing more accurate match probabilities should the breed of the animal of interest be known. The application of either set of frequencies has been scrutinized to evaluate their applicability in the field and are compared to current databases available in mainland Europe. A recommendation is made to use a minimum FST correction of 0.2 when estimating direct match likelihood ratios from whole country allele frequency databases
The Organization of Central Retinal Projections in Anna's Hummingbirds (Calypte anna) and Zebra Finches (Taeniopygia castanotis)
No full textHummingbirds (family Trochilidae) are easily recognized due to their unique ability to hover. Critical to hovering flight is head and body stabilization. In birds, stabilization during flight is mediated, among other things, by the detection of optic flow, the motion that occurs across the entire retina during self-motion. Given this increased requirement for stabilization, it is not surprising that previous studies have shown that hummingbirds have neural specializations in the visual pathways involved in the detection of optic flow. Particularly, previous studies have found some structural and functional differences in the hummingbird brain, in the pretectal nucleus lentiformis mesencephali (LM): compared to other avian species, LM shows a massive hypertrophy, and LM neurons have unique response properties to optic flow stimuli. Here, we used intraocular injections of a neural tracer, cholera toxin subunit B (CTB) conjugated with a fluorescent molecule, to study the retinal projections in Anna's hummingbirds (Calypte anna) and compare them to those of a similarly sized non-hovering species, the zebra finch (Taeniopygia castanotis). Retinal targets in both birds were similar and correspond closely to those reported in other birds from a variety of avian clades. Importantly, we found differences in the projections to LM between hummingbirds and zebra finches. Consistent with previous reports of specialization of LM, it was more intensely labelled compared to other retinal-recipient nuclei in hummingbirds. Moreover, this increase in intensity was most apparent in the lateral subnucleus. This study reinforces previous evidence that the LM of hummingbirds is adapted to sustain the unique flight abilities of this clade
Glycoengineering of nematode antigens using insect cells: a promising approach for producing bioactive vaccine antigens of the barber's pole worm Haemonchus contortus
No full textThe H11 antigens, located on the intestinal microvilli of Haemonchus contortus, comprise a group of homologous aminopeptidases essential for the parasite's digestion of blood meals. Native H11 proteins are promising vaccine antigens, capable of eliciting robust protective immunity against H. contortus in sheep and goats. However, recombinant forms of H11, produced either in conventional expression systems or in transgenic Caenorhabditis elegans, failed to replicate the protective efficacy of the native form, most likely due to two critical factors: improper glycosylation and protein misfolding. To address these limitations, we developed a novel strategy to produce recombinant Haemonchus antigens in glycoengineered insect cells. By introducing three C. elegans genes that alter the native N-glycosylation pathways of Hi5 insect cells we successfully expressed soluble H11 and GA1 antigens featuring nematode-specific glycan epitopes, including tri-fucosylated structures and the Gal beta 1,4Fuc motif. The glycoengineered H11 proteins retained aminopeptidase activity and stimulated cytokine secretion from ovine peripheral blood mononuclear cells in vitro. These findings establish a platform for producing bioactive vaccine antigens against the parasitic nematode H. contortus
Hindlimb functional morphology and locomotor biomechanics of the small Late Triassic pseudosuchian reptile Gracilisuchus stipanicicorum (Archosauria: Gracilisuchidae)
No full textGracilisuchus stipanicorum was a pseudosuchian archosaur from the Late Triassic period in Argentina. Because it was small-bodied with relatively long, slender limbs, traits that are potentially ancestral for archosaurs, such as its locomotor functions, are important to estimate. It has been illustrated as a quadruped with plantigrade autopodia, and probably with an 'erect' or 'semi-erect' stance, because it is a suchian archosaur, but there has been no deep analysis of these reconstructions. Here, we detail our reconstruction of a three-dimensional digital skeleton of Gracilisuchus from scans of the bones of four main specimens, including the holotype. In this procedure, we found hitherto unrecognised elements of the manus (metacarpals) and incorporated them in our model of the whole organism. We added estimated hindlimb musculature and body segment mass properties to form a musculoskeletal model. This model allowed us to address three key questions: Was it quadrupedal or bipedal; plantigrade or digitigrade; and more sprawling or more erect? Furthermore, we examine how its hindlimb muscle moment arms compare to those of three other small-bodied Triassic archosauriforms and an extant juvenile Nile crocodile in order to assess the diversity and potential evolutionary polarity of these traits. Our analyses of the model support the inferences that Gracilisuchus was quadrupedal (but facultative bipedalism cannot be ruled out) and plantigrade, and not strongly sprawling, but probably not strongly erect hindlimbs; although terming this posture 'semi-erect' would be an oversimplification. Gracilisuchus, as modelled here, seems to roughly be a reasonable approximation of the ancestral state of the archosaurian locomotor system. Our synthesis of numerous lines of evidence, from qualitative functional morphology to whole-body centre of mass and muscle moment arms, forms a new reconstruction of Gracilisuchus that future analyses can build on, both biomechanically and comparatively, in order to better understand archosauriform locomotor evolution
A framework to refocus the conversation around the welfare of UK purebred cats
No full textPreviously, consideration of purebred cat welfare has focused heavily on links between specific breeds and their predispositions to disease, extreme morphology, and behavioural traits. While these are certainly important to consider, negative messaging about purebred cats is often poorly evidenced and can be alienating to owners and breeders, with consequent limited or even negative welfare gain. Negative focus on individual breeds also risks overlooking the wider picture, where propagation of genetic traits that impinge upon welfare should be avoided across all cats (Felis catus). An account of purebred cat welfare must also consider husbandry and breeding practices, new experimental breeds and motivations behind changing acquisition trends. This review used a framework based on the five welfare needs from UK legislation, bolstered by published feline quality of life assessment tools, to review the literature on purebred cats. This aimed to re-orient the discussion on purebred cat welfare away from excessive focus on individual breed statements and instead explore broader, generalisable evidence-based welfare considerations. The review concludes that purebred cat welfare in the UK falls short of ideal in numerous ways. These include more obvious conformational concerns, such as osteochondrodysplasia in Scottish Folds and the increasingly flattened faces of brachycephalic cats. Several areas where strong evidence is lacking were also identified, including current breeding conditions, impact of morphological changes on social behaviour, and the breeding and keeping of hybrid cats. More evidence on the motivations behind owning cats with specific morphology is also required to better target interventions to improve the lives of cats
Descriptive epidemiology of long-term injuries in jump racing Thoroughbreds in Great Britain
No full textBackground Race-related injuries in horse racing, especially those requiring extended recovery, are a welfare concern and threaten the sport's social licence. Previous studies predominantly report on fatalities; however, serious non-fatal musculoskeletal injuries often end horses' racing careers or have a high recurrence risk. No recent studies have described or quantified long-term injuries (LTIs) in racing Thoroughbreds, which is essential to inform targeted risk prevention strategies.Objectives To describe the types, frequencies and incidences of LTIs in British jump racing.Study Design Retrospective cohort.Methods Analyses included all starts made in British hurdle and steeplechase races between 1 May 2018 and 30 April 2024. An LTI was defined as any non-fatal musculoskeletal injury incurred during racing, following which the horse had a minimum 90-day break from racing. LTIs were described by clinical diagnosis(es), body region(s) and anatomical structure(s) affected. Incidence per 1000 starts was calculated overall, by race type and year. Stratified incidence rates were calculated for selected injury types by age, sex, season, going and faller status.Results There were 918 LTIs recorded in 898 horses. The overall incidence of LTIs was 5.5 per 1000 jump starts (95% CI 5.2-5.9), with 5.2 per 1000 hurdle starts (95% CI 4.8-5.7) and 6.0 per 1000 steeplechase starts (95% CI 5.4-6.7). Tendon and ligament injuries (TLIs) were the most common, accounting for 72.9% of LTIs in hurdle starts and 70.6% in steeplechase starts. Firmer going, summer and falling in a race were associated with a higher LTI incidence.Main Limitations Classification of LTIs commonly relied upon presumptive diagnoses.Conclusions The incidence of LTIs was higher in steeplechase than hurdle starts, and TLIs are an important cause of morbidity in British jump racehorses. This study provides a benchmark for ongoing LTI surveillance in jump racing, against which to monitor the effects of future interventions
A Cross-Sectional Virological and Sero-Epidemiological Study of Exposures to Avian Influenza A(H5N1) and A(H9N2) Viruses in Live Bird Market Workers in Dhaka, Bangladesh
No full textBackground Avian influenza A viruses (AIVs) are endemic among poultry in Bangladesh sold at live bird markets (LBMs). We assessed virologic and serologic evidence of exposure to AIVs among LBM workers.Methods A cross-sectional study recruited 702 randomly sampled workers from 42 LBMs in Dhaka, Bangladesh, during 2017. Nasal and throat swabs collected from workers and air samples from LBMs were tested for influenza A virus by RT-PCR with positives subtyped for A(H5), A(H7), and A(H9). Baseline sera from 695 workers and follow-up sera from 89 workers with influenza A positive respiratory specimens were tested by microneutralization assay for antibodies to A(H5N1) clade 2.3.2.1a and A(H9N2) G1 lineage viruses circulating in poultry. A seropositive result was defined as a neutralizing antibody titer >= 1:40.Results Most LBM workers reported slaughtering (93.3%) and defeathering (84.5%) poultry. Ninety-nine (14.1%) had >= 1 respiratory specimen that tested influenza A positive but negative for A(H1) and A(H3). Of these 99, subtyping identified 28 (28.3%) A(H9), 2 (2%) A(H5), 3 (3%) both A(H5) and A(H9), and 66 (66.7%) A (nonsubtypeable). Influenza A viruses were detected in air samples at 25 LBMs (59.5%), including A(H9) only in 10 LBMs (40%), A(H5) only in one (4%), both A(H5) and A(H9) in 13 (52%), and one A (nonsubtypeable) (4%). None of the participants were seropositive for AIVs.Conclusions LBM workers had extensive exposure to AIVs, but none had serologic evidence of infection with A(H5N1) or A(H9N2) viruses circulating among poultry in Bangladesh. Ongoing surveillance of AIVs in LBMs and poultry workers is needed
Reassessment confirms motivational trade-offs and modulation of nociception in bumble bees
No full textThe dilemma surrounding the euthanasia or rehoming of a suspected banned-breed puppy
No full textLegislative amendments to the Dangerous Dogs Act 1991 implemented in February 2024 introduced restrictions on owning and rehoming XL Bully-type dogs. Consequent pressures on practice include rising requests to euthanase healthy animals and uncertainty around type assessment, particularly in puppies, with limited support for Dog Legislation Officers. This article examines the Registered Veterinary Nurse's responsibilities to animals, clients and the profession when asked to assist with euthanasia of a dog that may later meet the XL Bully-type definition. Legal context, moral considerations and professional accountability are explored with reference to the Royal College of Veterinary Surgeons Code of Professional Conduct for Veterinary Nurses, alongside practical guidance for decision-making, documentation and communication. The analysis is presented in a fictitious practice scenario reflecting issues reported across UK practice over the preceding 12 months and set in England and Wales, where the Dangerous Dogs Act primarily applies; parallel frameworks in Scotland and Northern Ireland, including the Control of Dogs (Scotland) Act 2010, are noted but fall outside scope