Molecular analysis of ovine CD1 expression

The CD1 family is a family of molecules with structural homology to MHC class I and low but significant sequence homology to both MHC class I and MHC class II. A key feature of the CD1 family is restricted tissue distribution. This distribution varies with isotype but includes cortical thymocytes, antigen presenting cells and intestinal epithelial cells. It has recently been shown that CD1 can present mycobacterial lipid antigens to T cells (Beckman et al. 1994, Sieling et al. 1995). Another major feature of CD1 is limited polymorphism which is in contrast to the extensive polymorphism associated with MHC molecules.In humans, five CD1 genes exist (CD1A-E) which encode four CD1 molecules (CDla-d). CD1 genes have also been described in mice, rats, rabbits and sheep. Studies in cattle and pigs have been at the protein level using anti-CD 1 mAbs. Studies on ovine CD1 were initially carried out using mAbs to study expression in cells and tissues. More recently, four ovine CD1 cDNA clones (SCD1A25, SCD1B42, SCD1B52 and SCD1T10) have been isolated all of which have closest homology to human CD IB (Ferguson et al. 1996). SCD1B52 contains a precise deletion of exon 4 which encodes the oc3 domain. Southern hybridization has indicated the existence of up to seven ovine CD1 genes.The aim of the work carried out in this thesis was to further investigate the ovine CD1 family and clarify the existing information at the cellular and molecular level. Initial studies utilised existing anti-CD 1 mAbs to clarify the pattern of tissue expression of ovine CD1. Two distinct clusters of mAbs were shown to exist - the majority recognise a molecule with tissue distribution similar to CD lb whilst three mAbs, SBU-T6, CC43 and CC118 demonstrate staining of tissue macrophages, the majority of B cells and monocytes in addition to thymocytes and dendritic cells. NH2-terminal sequencing was subsequently used to establish the antigens recognised by the mAbs SBU-T6 and CC14. This technique demonstrated that the CC14 antigen was consistent with the predicted sequence of the SCD1B42 cDNA clone whereas the SBU-T6 antigen had closest homology to the predicted amino-acid sequence of the human CD IE gene. This is particularly noteworthy as no protein product of the CD IE gene has yet been described in any species.Subsequent work attempted to isolate the gene encoding the molecule recognised by SBU-T6 using a transient expression system in which COS cells were transfected with a lymph node cDNA library contained within the vector pcDNA3. This was unsuccessful, however a sheep CD ID-like sequence was isolated from this library utilising primers based on the NH2-terminal sequence of the SBU-T6 antigen. Expression of the SCD1D gene was investigated using in situ hybridization and RT-PCR. SCD1D transcripts were demonstrated in thymus, liver, intestine, lymph node and PBLs. A further experiment investigated the expression of the SCD1B52 gene (which contains a precise deletion of exon 4). These studies have extended the knowledge of the ovine CD1 family and establish it as one of the most complex described to date. This work has demonstrated that sheep clearly express multiple CD1 isotypes as in man and rabbits in addition to the multiple CD IB-like genes reported previously

Embedding assessment literacy can enhance graduate attribute development in a Biomedical Sciences curriculum

This paper describes the successful implementation of an assessment literacy strategy within a Biomedical Sciences degree.Teaching was aligned with an assessment literacy framework and aimed to prepare undergraduates for a literature comprehension assessment. Students were introduced to the assessment purpose and an adapted Miller's pyramid model illustrated how the assessment contributed to competency development during their degree. Students read primary research papers and answered questions relating to the publications. They were then introduced to the processes of assessment and collaboratively graded answers of different standards. Finally, student and faculty grades were compared, differences considered, and key characteristics of answers discussed. Most students reported that they understood more about assessment standards than prior to the intervention (139/159 (87.4%)) and felt it had helped prepare them for their exam (138/159 (86.8%)). The majority also reported they had increased confidence in evaluating data (118/ 159 (74%)), communicating their reasoning (113/159 (71%)) and considering what a reader needs to know (127/159 (79.9%)). Students were asked to state the most important thing they had learned from the assessment literacy teaching. Notably, no responses referred to domain-specific knowledge. 129 free text responses were mapped to the University of Edinburgh graduate attribute framework. 93 (72%) statements mapped to the graduate attribute category "Research and Enquiry", 66 (51.16%) mapped to "Communication" and 21 (16.27%) mapped to "Personal and Intellectual Autonomy". To explore any longer-term impact of the assessment literacy teaching, a focus group was held with students from the same cohort, 2 years after the original intervention. Themes from this part of the study included that teaching had provided insights into standards and expectations for the assessment and the benefits of domain specific knowledge. A variety of aspects related to graduate attributes were also identified. Here, assessment literacy as a vehicle for graduate attribute development was an unexpected outcome. We propose that by explicitly engaging students with purpose, process, standards, and expectations, assessment literacy strategies may be used to successfully raise awareness of developmental progression, and enhance skills, aptitudes, and dispositions beneficial to Biomedical Sciences academic achievement and life after university

Taking the lead: learners’ experiences across the disciplines

The first year at university is a time of significant flux for students, as they adjust to unfamiliar environments, encounter new approaches to teaching and develop fresh learning strategies on the road to becoming self-directed learners. This sense of uncertainty may be compounded by the need to interact with unfamiliar and frequently complex online systems and technologies, possibly even before arrival. Furthermore, although technology is embedded seamlessly into the personal lives of many of today’s students, recent reports have questioned the widespread assumption that young adults have the sophisticated information skills and digital literacy needed to become autonomous learners. In this paper we present findings from a recently-completed study addressing these important issues. We investigated the utilisation of ICT and learning technologies by first-year undergraduates from a variety of different entry routes and academic disciplines, including Physics, Divinity and Veterinary Medicine, at the University of Edinburgh. The focus of the work was on the impact of technology on students’ transition to university and how this changed as they progressed through their first year. The overall shape of the research was based on a student-centred approach, with students’ own views and opinions placed central to the study; and used a holistic approach in which students’ use of e-learning and technology was set within the context of their learning experiences as a whole. To capture the breadth and complexity of their experiences we used a mixed-mode approach, including a series of reflective diaries recorded by learners (in video, audio or text format) together with surveys and focus groups. Students do not form a homogenous group, and findings in this area are inevitably complex. They have high expectations and are generally confident with technology; however, they may not always recognise technology’s potential to support and enhance learning. The term e-learning does not mean much to them; there is simply learning with strands of technology running through. This is reflected in a strong desire for face-to-face contact, with technology used to supplement and enhance this. Students are social, with informal group learning often facilitated by technology. They find their comfort zones and ways of working that are personal to them, and use technology to suit their own way of learning

Effective student feedback in clinical practice

Catriona Bell – ORCID: 0000-0001-8501-1697 https://orcid.org/0000-0001-8501-1697Item not available in this repository.Item previously deposited in University of Bristol repository at: https://research-information.bris.ac.uk/en/publications/96d3f1ae-b5ad-4c08-88ea-5281c5c7c269This article, the third in a series aimed at providing veterinary staff and students with tips and tools to enhance teaching and learning, considers how to give feedback to students in a constructive manner that enhances learning in practice.https://doi.org/10.1136/inp.g216936pubpub

Creating entrances to tree cavities attracts hollow-dependent fauna : proof of concept

Redressing the paucity of tree hollows is essential for conservation of hollow-dependent fauna in many landscapes around the world. We describe a method of accelerating availability of natural hollows in regenerating landscapes by mechanically creating entrances in tree stems that have existing voids or internal decay but have not yet developed entrances. We trialed this method in woodland and forest of south-eastern Australia in 39 stems in the closely related tree genera Eucalyptus and Angophora. Exploratory drilling of 10-mm diameter holes was used to detect the presence of internal decay or voids. We then drilled 40-, 65-, or 90-mm diameter entrance holes, depending on the size of the potential cavity, 2.4–4.8 m above ground level. Camera traps showed that drilled entrances were investigated or used within hours of creation. A diverse suite of invertebrates, reptiles, mammals, and birds were recorded entering or leaving entrances, including threatened species. All 39 holes were used by animals with up to six vertebrate taxa using some entrances. Two bird species excavated material from within cavities, and three species of marsupial were recorded taking nesting material into the cavities. This trial provides evidence that adding entrances to currently inaccessible internal cavities in trees has potential to accelerate development of habitat for hollow-dependent fauna, particularly in regenerating vegetation

Local lung responses following endobronchial elastase and lipopolysaccharide instillation in sheep

Chronic lipopolysaccharide (LPS) exposure may contribute to the pathogenesis of a number of lung diseases including COPD and emphysema. We sought to develop a large- animal model of emphysema using repeated LPS administration into sheep lung segments. An experimental protocol was designed to facilitate comparisons with elastase-treated and control segments within the same lung of individual sheep. Histopathologic evaluation of segments treated with LPS demonstrated low-grade inflammation characterized by an increase in the number of intra-alveolar macrophages and lymphocytes. Treated segments demonstrated a significant reduction in airspace surface area (ASA), an increase in percent disrupted alveolar attachments and the distance between normal alveolar attachments, and a reduction in the number of normal alveolar attachments surrounding nonrespiratory bronchioles. Coefficient of variation of individual ASA measurements in elastase-treated segments was indicative of a heterogeneous parenchymal response, in contrast to that associated with chronic LPS treatment. Our results demonstrate that chronic LPS treatment of individual lung segments in sheep induces microscopic emphysema qualitatively and quantitatively consistent with both accepted pathologic definitions of this condition and with that produced by airway instillation of elastolytic enzymes. Development of this phenotype is associated with evidence of downregulated activation of transforming growth factor beta

Differential cytokine gene expression profiles in the three pathological forms of sheep paratuberculosis

<p>Abstract</p> <p>Background</p> <p>Johne's disease is a chronic inflammatory disease of the gut caused by infection with <it>Mycobacterium avium </it>subspecies <it>paratuberculosis </it>(MAP). Symptoms include wasting, diarrhoea, loss of condition and eventual death. Three forms of Johne's disease have been described in sheep – paucibacillary, multibacillary and asymptomatic. The paucibacillary form is characterized by an inflammatory, Th1-type immune response. The multibacillary form of the disease, which disseminates the infection, is characterized by macrophage infiltration mediated by a Th2-type immune response, and asymptomatic animals have no clinical symptoms or pathology but are infected with MAP. What determines these three forms of the disease is unknown. To further understand these differences, we used real-time RT-PCR to compare the expression of thirteen cytokine and cytokine-related genes in ileal tissue from sheep with the three forms of the disease.</p> <p>Results</p> <p>Three pathological forms of sheep paratuberculosis were defined on the basis of histopathology, cytochemistry (Zeihl-Neelsen) and IS900 PCR. Paucibacillary lesions have largely T cell and eosinophil infiltration and are ZN negative; multibacillary lesions have macrophage infiltration and large numbers of acid-fast bacteria. The pauci- and multibacillary forms are linked to the differential expression of IFNγ and IL-10 respectively. In addition the increased levels of the proinflammatory cytokines (IL-1β and TNFα), IL-8, IL-18 and TRAF-1 in both diseased forms is indicative of persistent inflammatory lesions. No changes were seen in IL-1α in any sheep ileum tissues. Asymptomatic animals are IS900+ with normal histology but have significantly decreased levels of IL-18 and increased levels TNFα.</p> <p>Conclusion</p> <p>We have quantified the expression levels of thirteen cytokine and cytokine related genes in three forms of ovine paratuberculosis using real-time PCR analyses and confirm that sheep pauci- and multibacillary disease are linked to type 1 and type 2 T cell responses respectively. The expression patterns of other cytokines shows that both disease forms have an inflammatory aetiology but that the central role for IL-1α in bovine paratuberculosis is not seen in the sheep infection. Asymptomatic animals are infected and show no pathology but can be distinguished, in terms of cytokine expression pattern, from uninfected controls.</p