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"Todd, Helen"
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Mastitis Pathogens Mannheimia haemolytica, Staphylococcus aureus, and Streptococcus uberis Selectively Alter TLR Gene Transcription in Sheep Mammary Epithelial Cells
by
Tassi, Riccardo
,
Ballingall, Keith T.
,
Todd, Helen
in
Animal lactation
,
Animal welfare
,
Bacteria
2024
Despite the impact of mastitis on sheep production worldwide, the pathogenesis and host response to bacterial infection of the ovine mammary gland are poorly characterized. Studies in cattle highlight the significance of the mammary epithelium in pathogen recognition and the subsequent host response. The objective of this study was to assess bacterial adherence, invasion, and Toll like receptor (TLR) gene expression in primary sheep mammary epithelial cells (pMEC) following co-culture with the three principal mastitis pathogens of sheep, Mannheimia haemolytica, Staphylococcus aureus, and Streptococcus uberis. S. aureus was 140-fold more adherent than S. uberis and 850-fold more adherent than M. haemolytica. However, only S. aureus was internalized after 3 h of co-culture. TLR1, 2, 3, 4, 6, and 9 were shown to be constitutively transcribed by pMEC. M. haemolytica induced upregulation of transcription of TLR1, 2, 3, and 4. By contrast, S. uberis and S. aureus induced concentration-dependent transcription of TLR2 and TLR4 with a higher level of transcription in cells stimulated with the bacteria at a multiplicity of infection (MOI) of 200 compared to cells stimulated with a MOI of 20. These experiments define the range of TLR genes constitutively transcribed in sheep pMEC and show that bacterial infection has the capacity to regulate transcription in a species-specific and concentration-dependent manner.
Journal Article
Arts-based approaches to promoting health in sub-Saharan Africa: a scoping review
by
Lwanda, John
,
Kalinga, Chisomo
,
Abdulla, Sharifa
in
Acquired immune deficiency syndrome
,
Africa South of the Sahara - epidemiology
,
AIDS
2020
IntroductionArts-based approaches to health promotion have been used widely across sub-Saharan Africa (SSA), particularly in public health responses to HIV/AIDS. Such approaches draw on deep-rooted historical traditions of indigenous groups in combination with imported traditions which emerged from colonial engagement. To date, no review has sought to map the locations, health issues, art forms and methods documented by researchers using arts-based approaches in SSA.MethodsUsing scoping review methodology, 11 databases spanning biomedicine, arts and humanities and social sciences were searched. Researchers screened search results for papers using predefined criteria. Papers included in the review were read and summarised using a standardised proforma. Descriptive statistics were produced to characterise the location of the studies, art forms used or discussed, and the health issues addressed, and to determine how best to summarise the literature identified.ResultsSearches identified a total of 59 794 records, which reduced to 119 after screening. We identified literature representing 30 (62.5%) of the 48 countries in the SSA region. The papers covered 16 health issues. The majority (84.9%) focused on HIV/AIDS-related work, with Ebola (5.0%) and malaria (3.3%) also receiving attention. Most studies used a single art form (79.0%), but a significant number deployed multiple forms (21.0%). Theatre-based approaches were most common (43.7%), followed by music and song (22.6%), visual arts (other) (9.2%), storytelling (7.6%) and film (5.0%).ConclusionsArts-based approaches have been widely deployed in health promotion in SSA, particularly in response to HIV/AIDS. Historically and as evidenced by this review, arts-based approaches have provided a platform to facilitate enquiry, achieved significant reach and in some instances supported demonstrable health-related change. Challenges relating to content, power relations and evaluation have been reported. Future research should focus on broadening application to other conditions, such as non-communicable diseases, and on addressing challenges raised in research to date.
Journal Article
A novel technique for retrospective genetic analysis of the response to vaccination or infection using cell-free DNA from archived sheep serum and plasma
by
Ballingall, Keith T.
,
Hanks, Eve
,
Palarea-Albaladejo, Javier
in
Alleles
,
Animal genetic engineering
,
Australia
2020
Genetic variation is associated with differences in disease resistance and susceptibility among individuals within a population. To date, molecular genetic analyses of host responses have relied on extraction of genomic DNA from whole blood or tissue samples. However, such samples are not routinely collected during large-scale field studies. We demonstrate that cell-free genomic DNA (cfDNA) may be extracted and amplified from archived plasma samples, allowing retrospective analysis of host genetic diversity. This technique was also applicable to archived serum samples up to 35 years old and to different ruminant species. As proof of concept, we used this cfDNA approach to genotype the major histocompatibility complex (MHC) class II
DRB1
locus of 224 Merino sheep which had participated in field trials of a commercial
Haemonchus contortus
vaccine, Barbervax
®
, in Australia. This identified a total of 51 different
DRB1
alleles and their relative frequencies. This is the first study to examine host MHC diversity using DNA extracted from archived plasma samples, an approach that may be applied to retrospective analyses of genetic diversity and responses to vaccination or infection across different species and populations.
Journal Article
Radiomic Feature Characteristics of Ovine Pulmonary Adenocarcinoma
by
Savage, Jennifer
,
Storer, Nicole
,
Meehan, James
in
Adenocarcinoma
,
Anesthesia
,
Animal welfare
2025
Radiomic feature (RF) analysis of computed tomography (CT) images may aid the diagnosis and staging of ovine pulmonary adenocarcinoma (OPA). We assessed the RF characteristics of OPA tumours in JSRV-infected sheep compared to non-tumour lung tissues, examined their stability over time, and analysed RF variations in the nascent tumour field (NTF) and nascent tumour margin field (NTmF). In monthly CT scans, lung tissues were automatically segmented by density, and lung tumours were manually segmented. RFs were calculated for each imaging session, selected according to stability and reproducibility, and adjusted for volume dependence where appropriate. Comparisons between scans within sheep were facilitated through fiducial registration and spatial transformations. Initially, 9/36 RFs differed significantly from non-tumour lung tissue of similar density. Predominant RF changes included ngtdm_Complexity, glrlm_RunLNUnif_VN, and gldm_SmDHGLE. RFs in lung tumour segments showed time-dependent changes, whereas non-tumour lung tissue of similar density remained consistent. OPA lung tumour RF characteristics are distinct from those of other lung tissues of similar density and evolve as the tumour develops. Such characteristics suggest that radiomic analysis offers potential for the early detection and management of JSRV-related lung tumours. This research enhances the understanding of OPA imaging, potentially informing better diagnosis and control measures for naturally occurring infections.
Journal Article
Intramammary Immunisation Provides Short Term Protection Against Mannheimia haemolytica Mastitis in Sheep
by
Tassi, Riccardo
,
Ballingall, Keith T.
,
Ewing, David
in
Animal lactation
,
Animal welfare
,
Animals
2021
Mastitis affects both dairy and meat/wool sheep industries with losses due to reductions in milk quality and quantity, increased treatment costs and restricted lamb growth. Effective vaccines would be important tools for mastitis control. However, the development of vaccines against mastitis has proved challenging due to the failure to target protective immunity to the mammary gland. In order to target responses to the mammary gland, this study tested whether local administration directly into the gland through the teat canal or in the udder skin confers protection against an intramammary infection. In this study, we tested a vaccine that confers protection against respiratory disease caused by Mannheimia haemolytica to determine if it also protects against intramammary infection by the same organism. No evidence of protection was observed in animals that received a subcutaneous immunisation in the udder skin, however, intramammary immunisation provided almost complete protection against an experimental challenge administered 7 days post immunisation but not if the challenge was delivered 14 days post immunisation. To investigate further the nature of this variation in response, the somatic cell count and concentration of cytokines Interleukin-1β, Interleukin-10 and Interleukin-17A was determined in milk over the course of each study. Intramammary immunisation induced an inflammatory response within the mammary gland, characterised by increases in SCC and in the production of cytokines IL-1β, IL-10, and IL-17A. This response was similar to that observed in un-vaccinated control animals post challenge. The SCC and cytokine levels had returned to levels comparable with un-vaccinated controls prior to challenge at both 7 and 14 days post immunisation. The transient nature of the protective effect is consistent with the priming of an innate antibacterial response within the mammary gland which provides protection against challenge at 7 days but is diminished by 14 days post-vaccination. Further studies are planned to determine the nature of the innate immune mechanisms associated with the protective effect described here to determine whether it may be exploited to improve ruminant udder health.
Journal Article
Tracking Ovine Pulmonary Adenocarcinoma Development Using an Experimental Jaagsiekte Sheep Retrovirus Infection Model
by
Gregson, Rachael
,
Meehan, James
,
Chang, Ziyuan
in
Adenocarcinoma
,
Adenocarcinoma of Lung - diagnostic imaging
,
Adenocarcinoma of Lung - pathology
2024
Ovine pulmonary adenocarcinoma (OPA) is an infectious, neoplastic lung disease of sheep that causes significant animal welfare and economic issues throughout the world. Understanding OPA pathogenesis is key to developing tools to control its impact. Central to this need is the availability of model systems that can monitor and track events after Jaagsiekte sheep retrovirus (JSRV) infection. Here, we report the development of an experimentally induced OPA model intended for this purpose. Using three different viral dose groups (low, intermediate and high), localised OPA tumour development was induced by bronchoscopic JSRV instillation into the segmental bronchus of the right cardiac lung lobe. Pre-clinical OPA diagnosis and tumour progression were monitored by monthly computed tomography (CT) imaging and trans-thoracic ultrasound scanning. Post mortem examination and immunohistochemistry confirmed OPA development in 89% of the JSRV-instilled animals. All three viral doses produced a range of OPA lesion types, including microscopic disease and gross tumours; however, larger lesions were more frequently identified in the low and intermediate viral groups. Overall, 31% of JSRV-infected sheep developed localised advanced lesions. Of the sheep that developed localised advanced lesions, tumour volume doubling times (calculated using thoracic CT 3D reconstructions) were 14.8 ± 2.1 days. The ability of ultrasound to track tumour development was compared against CT; the results indicated a strong significant association between paired CT and ultrasound measurements at each time point (R2 = 0.799, p < 0.0001). We believe that the range of OPA lesion types induced by this model replicates aspects of naturally occurring disease and will improve OPA research by providing novel insights into JSRV infectivity and OPA disease progression.
Journal Article
Structural and functional diversity arising from intra- and inter-haplotype combinations of duplicated DQA and B loci within the ovine MHC
by
Ballingall, Keith T
,
Lantier, Frederic
,
Lantier, Isabelle
in
Biological evolution
,
Bovidae
,
CD4 antigen
2018
In sheep, the A and B loci encoding the α and β chains of the classical class II MHC molecules are DRA and DRB and DQA and DQB. Previous analyses described the duplication of the DQA and DQB genes. The majority of haplotypes include DQA1 and DQA2 loci, however, in a number of haplotypes, DQA1 appears absent and these haplotypes have been described as DQA1 null. In these haplotypes, the DQA2 locus is found in combination with a second locus which appeared more closely related to DQA2 than DQA1, hence the description of this locus as DQA2-like. Here we combine our previous analysis of the DQA transcripts with an analysis of the associated DQB transcripts in ten haplotypes from MHC homozygous animals. This allows the potential for surface expression of different haplotype combinations of DQA and B genes and the functional significance of DQA2-like and its predicted DQB partner to be determined. Atypical DQB transcripts (DQB2-like) were identified in haplotypes classified as DQA1-null and conserved DQB2-like orthologues were identified in other Bovidae indicating trans-species conservation of the allelic lineage. Functional combinations detected by co-transfection of DQ1, DQ2 and DQ2-like genes demonstrates the potential for a wide range of DQ molecules derived from both intra- and inter-haplotype as well as inter-locus combinations. We provide evidence that DQA2-like and B2-like genes form an evolutionary conserved pair which generates structurally distinct class II molecules that are likely to present a distinct range of peptides to CD4+ T cells.
Journal Article
Alcelaphine herpesvirus 1 glycoprotein B: recombinant expression and antibody recognition
by
Russell, George C
,
Manson, Erin D. T
,
Percival, Ann
in
Alcelaphine gammaherpesvirus 1
,
Alcelaphine herpesvirus 1
,
Animals
2016
The gammaherpesvirus alcelaphine herpesvirus 1 (AlHV-1) causes fatal malignant catarrhal fever (MCF) in susceptible species including cattle, but infects its reservoir host, wildebeest, without causing disease. Pathology in cattle may be influenced by virus-host cell interactions mediated by the virus glycoproteins. Cloning and expression of a haemagglutinin-tagged version of the AlHV-1 glycoprotein B (gB) was used to demonstrate that the AlHV-1-specific monoclonal antibody 12B5 recognised gB and that gB was the main component of the gp115 complex of AlHV-1, a glycoprotein complex of five components identified on the surface of AlHV-1 by immunoprecipitation and radiolabelling. Analysis of AlHV-1 virus particles showed that the native form of gB was detected by mAb 12B5 as a band of about 70 kDa, whilst recombinant gB expressed by transfected HEK293T cells appeared to be subject to additional cleavage and incomplete post-translational processing. Antibody 12B5 recognised an epitope on the N-terminal furin-cleaved fragment of gB on AlHV-1 virus particles. It could be used to detect recombinant and virus-expressed gB on western blots and on the surface of infected cells by flow cytometry, whilst recombinant gB was detected on the surface of transfected cells by immunofluorescence. Recombinant gB has potential as an antigen for ELISA detection of MCF virus infection and as a candidate vaccine antigen.
Journal Article
Justice for the Environment: Developing a Set of Indicators of Environmental Justice for Scotland
by
Todd, Helen
,
Zografos, Christos
in
Analytical Hierarchy Process
,
Environmental Justice
,
Indicator
2005
This paper explores the context of environmental justice (EJ) in Scotland, and presents a case study whereby the main attributes for an indicator of EJ were identified, encompassing procedural and distributive aspects of justice. Through a participatory process, weights were assigned
using a Multi-Criteria Analysis tool, the Analytical Hierarchy Process (AHP). Results show that overall, environmental injustices are mostly associated by respondents to unequal distribution of health burdens due to pollution, yet greater weight is attached to procedural justice by community
environmental activists. The paper suggests that AHP may be applied to many situations and could form a basis for the development of tools to address and deliver EJ in Scotland.
Journal Article
Rewriting the egyptian river: the nile in hellenistic and imperial greek literature
2015
This thesis explores Hellenistic and imperial Greek texts that represent or discuss the river Nile. The thesis makes an original contribution to scholarship by examining such texts in he light of the history of Greek discourse about the Nile and in the context of social, political and cultural changes, and takes account of relevant ancient Egyptian texts. I begin with an introduction that provides a survey of earlier scholarship about the Nile in Greek literature, before identifying three themes central to the thesis: the relationship between Greek and Egyptian texts, the tension between rationalism and divinity, and the interplay between power and literature. I then highlight both the cultural significance of rivers in classical Greek culture, and the polyvalence of the river Nile and its inundation in ancient Egyptian religion and literature. Chapter 1 examines the significance of Diodorus Siculus' representation of the Nile at the beginning of his universal history; it argues that the river's prominence constructs Egypt as a primeval landscape that allows the historian access to the distant past. The Nile is also seen to be useful to the historian as a conceptual parallel for his historiographical project. Whereas Diodorus begins his universal history with the Nile, Strabo closes his universal geography with Egypt; the second chapter demonstrates how Strabo incorporates the Nile into his vision of the new Roman world. Chapter 3 presents a diachronic study of Greek discourse concerning the two major Nilotic problems, the cause of the annual inundation and the location of the sources. It examines first the construction of the debates, and second the transformation of that tradition in Aelius Aristides' Egyptian Oration. The functions of the Nile in Greek praise-poetry are the subject of chapter 4; it is shown that the Nile and its benefactions are used by poets to lay claim to political, religious or cultural authority, and to situate Egypt within an expanding oikoumene. The fifth and final chapter turns to Greek narrative fictions from the imperial period. The chapter demonstrates that the Nile is more familiar than exotic in these texts. It is shown that Xenophon of Ephesus and Achilles Tatius play with the trope of 'novelty' in this very familiar literary landscape, while Heliodorus articulates a more profound disruption of the expected Egyptian tropes, and ultimately replaces Egypt with Ethiopia as a new Nilotic environment.
Dissertation