33 results on '"Shiels P"'
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2. Through the Cat-Map Gateway: A Brief History of Cataract Genetics
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Alan Shiels
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lens ,cataract(s) ,inherited ,age-related ,genes ,mutations/variants ,Genetics ,QH426-470 - Abstract
Clouding of the transparent eye lens, or cataract(s), is a leading cause of visual impairment that requires surgical replacement with a synthetic intraocular lens to effectively restore clear vision. Most frequently, cataract is acquired with aging as a multifactorial or complex trait. Cataract may also be inherited as a classic Mendelian trait—often with an early or pediatric onset—with or without other ocular and/or systemic features. Since the early 1990s, over 85 genes and loci have been genetically associated with inherited and/or age-related forms of cataract. While many of these underlying genes—including those for lens crystallins, connexins, and transcription factors—recapitulate signature features of lens development and differentiation, an increasing cohort of unpredicted genes, including those involved in cell-signaling, membrane remodeling, and autophagy, has emerged—providing new insights regarding lens homeostasis and aging. This review provides a brief history of gene discovery for inherited and age-related forms of cataract compiled in the Cat-Map database and highlights potential gene-based therapeutic approaches to delay, reverse, or even prevent cataract formation that may help to reduce the increasing demand for cataract surgery.
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- 2024
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3. What Can the Gut Microbiota of Animals Teach Us about the Relationship between Nutrition and Burden of Lifestyle Diseases?
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Denise Mafra, Natália A. Borges, Beatriz G. Baptista, Layla F. Martins, Gillian Borland, Paul G. Shiels, and Peter Stenvinkel
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biomimetics ,food ,chronic diseases ,gut microbiota ,Nutrition. Foods and food supply ,TX341-641 - Abstract
The gut microbiota performs several crucial roles in a holobiont with its host, including immune regulation, nutrient absorption, synthesis, and defense against external pathogens, significantly influencing host physiology. Disruption of the gut microbiota has been linked to various chronic conditions, including cardiovascular, kidney, liver, respiratory, and intestinal diseases. Studying how animals adapt their gut microbiota across their life course at different life stages and under the dynamics of extreme environmental conditions can provide valuable insights from the natural world into how the microbiota modulates host biology, with a view to translating these into treatments or preventative measures for human diseases. By modulating the gut microbiota, opportunities to address many complications associated with chronic diseases appear. Such a biomimetic approach holds promise for exploring new strategies in healthcare and disease management.
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- 2024
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4. Sex Differences in Cancer Incidence Rates by Race and Ethnicity: Results from the Surveillance, Epidemiology, and End Results (SEER) Registry (2000–2019)
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Sararat Tosakoon, Wayne R. Lawrence, Meredith S. Shiels, and Sarah S. Jackson
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sex differences ,cancer epidemiology ,cancer registries ,SEER ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Men have 2–3 times the rate of most non-sex-specific cancers compared to women, but whether this is due to differences in biological or environmental factors remains poorly understood. This study investigated sex differences in cancer incidence by race and ethnicity. Cancer incidence data from the Surveillance, Epidemiology, and End Result (SEER) program (2000–2019) were used to calculate male-to-female incidence rate ratios (MF IRRs) for each cancer site, stratified by race and ethnicity, and age-standardized to the 2000 U.S. population for individuals ages ≥ 20 years. Among 49 cancer sites, 44 showed male predominance (MF IRR > 1), with seven inconsistencies across race and ethnicity, including cancers of the lip, tongue, hypopharynx, retroperitoneum, larynx, pleura cancers, and Kaposi sarcoma. Four cancers exhibited a female predominance (MF IRR < 1), with only gallbladder and anus cancers varying by race and ethnicity. The MF IRRs for cancer of the cranial nerves and other nervous system malignancies showed no sex differences and were consistent (MF IRR = 1) across race and ethnicity. The MF IRRs for most cancers were consistent across race and ethnicity, implying that biological etiologies are driving the observed sex difference. The lack of MF IRR variability by race and ethnicity suggests a minimal impact of environmental exposure on sex differences in cancer incidence. Further research is needed to identify biological drivers of sex differences in cancer etiology.
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- 2024
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5. Enrichment of Whole-Grain Breads with Food-Grade Extracted Apple Pomace Bioactives Enhanced Their Anti-Inflammatory, Antithrombotic and Anti-Oxidant Functional Properties
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Alexandros Tsoupras, Donal Moran, Katie Shiels, Sushanta Kumar Saha, Ibrahim M. Abu-Reidah, Raymond H. Thomas, and Shane Redfern
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apple pomace ,whole-grain bread ,bioactives ,polar lipids ,phenolics ,carotenoids ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Apple pomace (AP) is a bio-waste product of apples that is co-produced as a by-product during apples’ processing for making apple-based products, mainly apple juice, cider and vinegar. AP is a rich source of several bioactives that can be valorized as ingredients for developing novel functional foods, supplements and nutraceuticals. Within the present study, food-grade extracts from AP with different tannin contents were found to contain bioactive polar lipids (PLs), phenolics and carotenoids with strong anti-oxidant, antithrombotic and anti-inflammatory properties. The extract from the low-in-tannins AP showed stronger anti-inflammatory potency in human platelets against the potent thrombo-inflammatory mediator platelet-activating factor (PAF), while it also exhibited considerable anti-platelet effects against the standard platelet agonist, adenosine diphosphate (ADP). The infusion of 0.5–1.0 g of this bioactive AP extract as functional ingredients for whole-grain bread-making resulted in the production of novel bio-functional bread products with stronger anti-oxidant, antithrombotic and anti-inflammatory potency against both PAF and ADP in human platelets, compared to the standard non-infused control breads. Structural analysis by LCMS showed that the PL-bioactives from all these sources (AP and the bio-functional breads) are rich in bioactive unsaturated fatty acids (UFA), especially in the omega-9 oleic acid (OA; 18:1n9), the omega-3 alpha linolenic acid (ALA; 18:n3) and the omega-6 linoleic acid (LA; 18:2n6), which further supports their strong anti-inflammatory and antithrombotic properties. All food-grade extracted AP including that infused with AP-bioactives novel functional breads showed higher hydrophilic, lipophilic and total phenolic content, as well as total carotenoid content, and subsequently stronger antioxidant capacity. These results showed the potential of appropriately valorizing AP-extracts in developing novel bio-functional bakery products, as well as in other health-promoting applications. Nevertheless, more studies are needed to fully elucidate and/or validate the anti-inflammatory, antithrombotic and antioxidant potential of novel bio-functional products across the food and cosmetic sectors when infused with these AP bioactives.
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- 2024
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6. A Cataract-Causing Mutation in the TRPM3 Cation Channel Disrupts Calcium Dynamics in the Lens
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Yuefang Zhou, Thomas M. Bennett, Philip A. Ruzycki, Zhaohua Guo, Yu-Qing Cao, Mohammad Shahidullah, Nicholas A. Delamere, and Alan Shiels
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lens ,cataract ,TRPM3 ,calcium ,gene expression ,miR-204/211 ,Cytology ,QH573-671 - Abstract
TRPM3 belongs to the melastatin sub-family of transient receptor potential (TRPM) cation channels and has been shown to function as a steroid-activated, heat-sensitive calcium ion (Ca2+) channel. A missense substitution (p.I65M) in the TRPM3 gene of humans (TRPM3) and mice (Trpm3) has been shown to underlie an inherited form of early-onset, progressive cataract. Here, we model the pathogenetic effects of this cataract-causing mutation using ‘knock-in’ mutant mice and human cell lines. Trpm3 and its intron-hosted micro-RNA gene (Mir204) were strongly co-expressed in the lens epithelium and other non-pigmented and pigmented ocular epithelia. Homozygous Trpm3-mutant lenses displayed elevated cytosolic Ca2+ levels and an imbalance of sodium (Na+) and potassium (K+) ions coupled with increased water content. Homozygous TRPM3-mutant human lens epithelial (HLE-B3) cell lines and Trpm3-mutant lenses exhibited increased levels of phosphorylated mitogen-activated protein kinase 1/extracellular signal-regulated kinase 2 (MAPK1/ERK2/p42) and MAPK3/ERK1/p44. Mutant TRPM3-M65 channels displayed an increased sensitivity to external Ca2+ concentration and an altered dose response to pregnenolone sulfate (PS) activation. Trpm3-mutant lenses shared the downregulation of genes involved in insulin/peptide secretion and the upregulation of genes involved in Ca2+ dynamics. By contrast, Trpm3-deficient lenses did not replicate the pathophysiological changes observed in Trpm3-mutant lenses. Collectively, our data suggest that a cataract-causing substitution in the TRPM3 cation channel elicits a deleterious gain-of-function rather than a loss-of-function mechanism in the lens.
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- 2024
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7. The Ex Vivo and In Vitro Antithrombotic Properties of Fermented Irish Ovine Yogurt Drink
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Sakshi Hans, Harishkumar Rajendran, Katie Shiels, Sushanta Kumar Saha, Alexandros Tsoupras, Ronan Lordan, and Ioannis Zabetakis
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yogurt ,polar lipids ,platelet aggregation ,thrombin-activator receptor peptide-6 (TRAP-6) ,nutraceuticals ,antithrombotic ,Plant ecology ,QK900-989 ,Animal biochemistry ,QP501-801 ,Biology (General) ,QH301-705.5 - Abstract
Platelet function is closely linked to cardiovascular health. Functional foods such as yogurt and oily fish are enriched in bioactive polar lipids, which can reduce platelet activation and the incidence of cardiovascular disease. This pilot project investigated the effect of fermented ovine yogurt on platelet sensitivity in human plasma. Overall, in vitro studies established that yogurt lipid fractions inhibit platelet aggregation. Preliminary dietary intervention data indicate that yogurt intake may reduce platelet activation against the thrombin pathway, compared to the placebo. However, larger studies are required to robustly establish the effect of yogurt intake on platelet sensitivity, following this interim analysis.
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- 2023
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8. Microvesicle-Mediated Tissue Regeneration Mitigates the Effects of Cellular Ageing
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Nikolaos Panagiotou, Dagmara McGuinness, Armand M. G. Jaminon, Barend Mees, Colin Selman, Leon Schurgers, and Paul G. Shiels
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ageing ,regenerative medicine ,stem cells ,extracellular vesicles ,microvesicles ,exosomes ,Cytology ,QH573-671 - Abstract
Extracellular vesicles (EVs), comprising microvesicles (MVs) and exosomes (Exos), are membranous vesicles secreted by cells which mediate the repair of cellular and tissue damage via paracrine mechanisms. The action of EVs under normative and morbid conditions in the context of ageing remains largely unexplored. We demonstrate that MVs, but not Exos, from Pathfinder cells (PCs), a putative stem cell regulatory cell type, enhance the repair of human dermal fibroblast (HDF) and mesenchymal stem cell (MSC) co-cultures, following both mechanical and genotoxic stress. Critically, this effect was found to be both cellular age and stress specific. Notably, MV treatment was unable to repair mechanical injury in older co-cultures but remained therapeutic following genotoxic stress. These observations were further confirmed in human dermal fibroblast (HDF) and vascular smooth muscle cell (VSMC) co-cultures of increasing cellular age. In a model of comorbidity comprising co-cultures of HDFs and highly senescent abdominal aortic aneurysm (AAA) VSMCs, MV administration appeared to be senotherapeutic, following both mechanical and genotoxic stress. Our data provide insights into EVs and the specific roles they play during tissue repair and ageing. These data will potentiate the development of novel cell-free therapeutic interventions capable of attenuating age-associated morbidities and avoiding undesired effects.
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- 2023
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9. Vitamin K and Hallmarks of Ageing: Focus on Diet and Gut Microbiome
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Lu Dai, Denise Mafra, Paul G. Shiels, Tilman M. Hackeng, Peter Stenvinkel, and Leon J. Schurgers
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vitamin K ,ageing ,gut microbiome ,food pattern ,Nutrition. Foods and food supply ,TX341-641 - Abstract
Vitamin K and vitamin K-dependent proteins have been reported to be associated with a large spectrum of age-related diseases. While most of these associations have been deduced from observational studies, solid evidence for the direct impact of vitamin K on cellular senescence remains to be proven. As vitamin K status reflects the complexity of interactions between dietary intake, gut microbiome activity and health, we will demonstrate the pivotal role of the diet-microbiome-health axis in human ageing and exemplify how vitamin K is implicated therein. We propose that food quality (i.e., food pattern) should be highlighted beyond the quantity of total vitamin K intake. Instead of focusing on a single nutrient, exploring a healthy diet containing vitamin K may be more strategic. As such, healthy eating patterns can be used to make dietary recommendations for the public. Emerging evidence suggests that dietary vitamin K is a modulator of the diet-microbiome-health axis, and this needs to be incorporated into the investigation of the impact of vitamin K on gut microbial composition and metabolic activities, along with host health outcomes. In addition, we highlight several critical caveats that need to be acknowledged regarding the interplay between diet, vitamin K, gut microbiome and host health that is pivotal for elucidating the role of vitamin K in ageing and responding to the urgent call of healthy eating concerning public health.
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- 2023
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10. Differential Methylation of Telomere-Related Genes Is Associated with Kidney Disease in Individuals with Type 1 Diabetes
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Claire Hill, Seamus Duffy, Laura M. Kettyle, Liane McGlynn, Niina Sandholm, Rany M. Salem, Alex Thompson, Elizabeth J. Swan, Jill Kilner, Peter Rossing, Paul G. Shiels, Maria Lajer, Per-Henrik Groop, Alexander Peter Maxwell, Amy Jayne McKnight, and on behalf of the GENIE Consortium
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biological ageing ,diabetic kidney disease ,epigenetic ,genetic ,methylation ,SNP ,Genetics ,QH426-470 - Abstract
Diabetic kidney disease (DKD) represents a major global health problem. Accelerated ageing is a key feature of DKD and, therefore, characteristics of accelerated ageing may provide useful biomarkers or therapeutic targets. Harnessing multi-omics, features affecting telomere biology and any associated methylome dysregulation in DKD were explored. Genotype data for nuclear genome polymorphisms in telomere-related genes were extracted from genome-wide case–control association data (n = 823 DKD/903 controls; n = 247 end-stage kidney disease (ESKD)/1479 controls). Telomere length was established using quantitative polymerase chain reaction. Quantitative methylation values for 1091 CpG sites in telomere-related genes were extracted from epigenome-wide case–control association data (n = 150 DKD/100 controls). Telomere length was significantly shorter in older age groups (p = 7.6 × 10−6). Telomere length was also significantly reduced (p = 6.6 × 10−5) in DKD versus control individuals, with significance remaining after covariate adjustment (p = 0.028). DKD and ESKD were nominally associated with telomere-related genetic variation, with Mendelian randomisation highlighting no significant association between genetically predicted telomere length and kidney disease. A total of 496 CpG sites in 212 genes reached epigenome-wide significance (p ≤ 10−8) for DKD association, and 412 CpG sites in 193 genes for ESKD. Functional prediction revealed differentially methylated genes were enriched for Wnt signalling involvement. Harnessing previously published RNA-sequencing datasets, potential targets where epigenetic dysregulation may result in altered gene expression were revealed, useful as potential diagnostic and therapeutic targets for intervention.
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- 2023
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11. Autophagy Requirements for Eye Lens Differentiation and Transparency
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Lisa Brennan, M. Joseph Costello, J. Fielding Hejtmancik, A. Sue Menko, S. Amer Riazuddin, Alan Shiels, and Marc Kantorow
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autophagy ,lens ,differentiation ,cataract ,Cytology ,QH573-671 - Abstract
Recent evidence points to autophagy as an essential cellular requirement for achieving the mature structure, homeostasis, and transparency of the lens. Collective evidence from multiple laboratories using chick, mouse, primate, and human model systems provides evidence that classic autophagy structures, ranging from double-membrane autophagosomes to single-membrane autolysosomes, are found throughout the lens in both undifferentiated lens epithelial cells and maturing lens fiber cells. Recently, key autophagy signaling pathways have been identified to initiate critical steps in the lens differentiation program, including the elimination of organelles to form the core lens organelle-free zone. Other recent studies using ex vivo lens culture demonstrate that the low oxygen environment of the lens drives HIF1a-induced autophagy via upregulation of essential mitophagy components to direct the specific elimination of the mitochondria, endoplasmic reticulum, and Golgi apparatus during lens fiber cell differentiation. Pioneering studies on the structural requirements for the elimination of nuclei during lens differentiation reveal the presence of an entirely novel structure associated with degrading lens nuclei termed the nuclear excisosome. Considerable evidence also indicates that autophagy is a requirement for lens homeostasis, differentiation, and transparency, since the mutation of key autophagy proteins results in human cataract formation.
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- 2023
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12. Fermentation Enhances the Anti-Inflammatory and Anti-Platelet Properties of Both Bovine Dairy and Plant-Derived Dairy Alternatives
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Kyeesha Glenn-Davi, Alison Hurley, Eireann Brennan, Jack Coughlan, Katie Shiels, Donal Moran, Sushanta Kumar Saha, Ioannis Zabetakis, and Alexandros Tsoupras
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fermentation ,bovine ,dairy alternatives ,yogurt ,anti-inflammatory ,anti-platelet ,Fermentation industries. Beverages. Alcohol ,TP500-660 - Abstract
Within the present study, the effects of fermentation on the anti-inflammatory and anti-platelet properties of both homemade and commercially purchased bovine dairy and almond, coconut, and rice-based dairy alternatives were evaluated. The extracted total lipids (TL) from homemade and commercially purchased fermented and unfermented bovine, almond, coconut, and rice-based products were further separated into their neutral lipids (NL) and polar lipids (PL) fractions by counter current distribution. The TL, PL, and NL of each sample were assessed in human platelets against the inflammatory and thrombotic mediator, platelet-activating factor (PAF), and the well-established platelet agonist, adenosine 5′ diphosphate (ADP). In all samples, the PL fractions showed significantly stronger inhibitory effects against human platelet aggregation induced by PAF or ADP, in comparison to the TL and NL, with higher specificity against PAF. PL of all fermented products (bovine yogurt and fermented dairy alternatives from almond, rice, and coconut), exhibited the strongest anti-inflammatory and anti-platelet potency, in comparison to PL from their initial pasteurized materials (bovine milk and rice, almond, and coconut-based dairy alternative drinks). PL of the pasteurized rice-based drink and, especially PL from the novel homemade rice-based fermented product (HMFRD), showed the strongest anti-PAF and anti-ADP potency compared to all samples, with anti-PAF activity being most potent overall. The unfermented pasteurized coconut-based drink showed the lowest anti-inflammatory and anti-platelet potency, and the bovine and almond-based fermented products showed an intermediate effect. Further lipidomics with LC-MS analysis of all these PL fractions revealed that fermentation altered their fatty acid content in a way that decreased their degree of saturation and increased the content of unsaturated fatty acids, thus providing a rationale for the stronger anti-inflammatory and anti-platelet potency of the more unsaturated PL fractions of the fermented products. This study has shown that fermentation alters the fatty acid content and the bio-functionality of the PL bioactives in both fermented bovine dairy and plant-based dairy alternatives, and subsequently improved their anti-inflammatory and anti-platelet functional properties.
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- 2022
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13. Refining Glioblastoma Surgery through the Use of Intra-Operative Fluorescence Imaging Agents
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Oluwakanyinsolami Netufo, Kate Connor, Liam P. Shiels, Kieron J. Sweeney, Dan Wu, Donal F. O’Shea, Annette T. Byrne, and Ian S. Miller
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glioblastoma ,fluorescence guided surgery ,5-ALA ,fluorescein ,NIR-AZA ,Medicine ,Pharmacy and materia medica ,RS1-441 - Abstract
Glioblastoma (GBM) is the most aggressive adult brain tumour with a dismal 2-year survival rate of 26–33%. Maximal safe resection plays a crucial role in improving patient progression-free survival (PFS). Neurosurgeons have the significant challenge of delineating normal tissue from brain tumour to achieve the optimal extent of resection (EOR), with 5-Aminolevulinic Acid (5-ALA) the only clinically approved intra-operative fluorophore for GBM. This review aims to highlight the requirement for improved intra-operative imaging techniques, focusing on fluorescence-guided imaging (FGS) and the use of novel dyes with the potential to overcome the limitations of current FGS. The review was performed based on articles found in PubMed an.d Google Scholar, as well as articles identified in searched bibliographies between 2001 and 2022. Key words for searches included ‘Glioblastoma’ + ‘Fluorophore’+ ‘Novel’ + ‘Fluorescence Guided Surgery’. Current literature has favoured the approach of using targeted fluorophores to achieve specific accumulation in the tumour microenvironment, with biological conjugates leading the way. These conjugates target specific parts overexpressed in the tumour. The positive results in breast, ovarian and colorectal tissue are promising and may, therefore, be applied to intracranial neoplasms. Therefore, this design has the potential to produce favourable results in GBM by reducing the residual tumour, which translates to decreased tumour recurrence, morbidity and ultimately, mortality in GBM patients. Several preclinical studies have shown positive results with targeted dyes in distinguishing GBM cells from normal brain parenchyma, and targeted dyes in the Near-Infrared (NIR) emission range offer promising results, which may be valuable future alternatives.
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- 2022
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14. A Survey of Farm Management Practices Relating to the Risk Factors, Prevalence, and Causes of Lamb Mortality in Ireland
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Dwayne Shiels, Jason Loughrey, Cathy M. Dwyer, Kevin Hanrahan, John F. Mee, and Timothy W. J. Keady
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ewe productivity ,gross margin ,questionnaire ,hygiene ,colostrum ,Veterinary medicine ,SF600-1100 ,Zoology ,QL1-991 - Abstract
Lamb mortality is a key factor influencing ewe productivity and profitability. The current study investigated risk factors associated with and management practices implemented on sheep farms to reduce lamb mortality. A survey consisting of 13 multiple-part questions (57 separate questions) was administered to all sheep farmers participating in the Teagasc National Farm Survey, representative of the Irish national population of sheep farms. A total of 60% of respondents identify mating or lambing date, and this practice tended to be associated with reduced lamb mortality (1.2%, p = 0.08). Individual lambing pens were used by 88% of farmers, but 26% did not clean or disinfect them. A total of 79% and 9.5% of farmers applied iodine to all lambs’ navels and administered antibiotics to all lambs to treat and/or prevent diseases, respectively. Most farmers vaccinated their ewes (86%) and lambs (79%) against clostridial diseases and/or pasteurellosis; 13% vaccinated against abortion agents. Lamb mortality tended to be lower (Kruskal–Wallis (KW) = 2.749; p = 0.09) on farms that used stomach tubing, heat box, iodine, hospital, and individual pens compared with farms that do not implement all those practices. Predators, lamb birth weight, and diseases were perceived by respondents to be the three main causes of live-born lamb mortality. The gross margin is significantly higher on lowland farms by €37 per ewe compared with hill farms (Kruskal–Wallis (KW) = 4.056; p < 0.001). The combination of full-time farming and the use of hospital and individual pens improved gross margin (€18/ewe, p = 0.028). It is concluded that on-farm management practices affect both lamb mortality and flock gross margin.
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- 2021
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15. Incivility in Higher Education: Challenges of Inclusion for Neurodiverse Students with Traumatic Brain Injury in Ireland
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Teresa Shiels, Neil Kenny, Roy Shiels, and Patricia Mannix-McNamara
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incivility ,students with traumatic brain injury ,higher education ,power ,Social sciences (General) ,H1-99 - Abstract
This paper explores the lived experience of incivility for neurodiverse students with traumatic brain injury (TBI) in Ireland. The higher education (HE) environment can be challenging for students with TBI. Incivility is common in higher education, and students with disabilities such as TBI are often marginalized within academia, making them more vulnerable to incivility. For this paper, data are drawn from the first author’s autoethnographic study, and is supplemented with semi-structured interviews from a sample of HE seven students also with TBI. Results revealed that participants’ experiences of incivility were common and were linked to the organizational culture of higher education. Our experiences point to a need for better responsiveness when interactions are frequently uncivil, despite there being policies that recognize diversity and equality. This is the first paper of its kind to explore this particular experience in Ireland and the purpose of this paper is to raise awareness of the challenges of neurodiverse students and how they are exacerbated by organizational and interpersonal incivility.
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- 2021
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16. Mutation of the EPHA2 Tyrosine-Kinase Domain Dysregulates Cell Pattern Formation and Cytoskeletal Gene Expression in the Lens
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Yuefang Zhou, Thomas M. Bennett, Philip A. Ruzycki, and Alan Shiels
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lens ,ephrin receptor ,cell patterning ,cytoskeleton ,cataract ,Cytology ,QH573-671 - Abstract
Genetic variations in ephrin type-A receptor 2 (EPHA2) have been associated with inherited and age-related forms of cataract in humans. Here, we have characterized the eye lens phenotype and transcript profile of germline Epha2 knock-in mutant mice homozygous for either a missense variant associated with age-related cataract in humans (Epha2-Q722) or a novel insertion-deletion mutation (Epha2-indel722) that were both located within the tyrosine-kinase domain of EPHA2. Confocal imaging of ex vivo lenses from Epha2-indel722 mice on a fluorescent reporter background revealed misalignment of epithelial-to-fiber cell meridional-rows at the lens equator and severe disturbance of Y-suture formation at the lens poles, whereas Epha2-Q722 lenses displayed mild disturbance of posterior sutures. Immunofluorescent labeling showed that EPHA2 was localized to radial columns of hexagonal fiber cell membranes in Epha2-Q722 lenses, whereas Epha2-indel722 lenses displayed disorganized radial cell columns and cytoplasmic retention of EPHA2. Immunoprecipitation/blotting studies indicated that EPHA2 formed strong complexes with Src kinase and was mostly serine phosphorylated in the lens. RNA sequencing analysis revealed differential expression of several cytoskeleton-associated genes in Epha2-mutant and Epha2-null lenses including shared downregulation of Lgsn and Clic5. Collectively, our data suggest that mutations within the tyrosine-kinase domain of EPHA2 result in lens cell patterning defects and dysregulated expression of several cytoskeleton-associated proteins.
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- 2021
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17. Settable Polymeric Autograft Extenders in a Rabbit Radius Model of Bone Formation
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Lauren A. Boller, Madison A.P. McGough, Stefanie M. Shiels, Craig L. Duvall, Joseph C. Wenke, and Scott A. Guelcher
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autograft extender ,bone ,polyurethane ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
Autograft (AG) is the gold standard for bone grafts, but limited quantities and patient morbidity are associated with its use. AG extenders have been proposed to minimize the volume of AG while maintaining the osteoinductive properties of the implant. In this study, poly(ester urethane) (PEUR) and poly(thioketal urethane) (PTKUR) AG extenders were implanted in a 20-mm rabbit radius defect model to evaluate new bone formation and graft remodeling. Outcomes including µCT and histomorphometry were measured at 12 weeks and compared to an AG (no polymer) control. AG control examples exhibited new bone formation, but inconsistent healing was observed. The implanted AG control was resorbed by 12 weeks, while AG extenders maintained implanted AG throughout the study. Bone growth from the defect interfaces was observed in both AG extenders, but residual polymer inhibited cellular infiltration and subsequent bone formation within the center of the implant. PEUR-AG extenders degraded more rapidly than PTKUR-AG extenders. These observations demonstrated that AG extenders supported new bone formation and that polymer composition did not have an effect on overall bone formation. Furthermore, the results indicated that early cellular infiltration is necessary for harnessing the osteoinductive capabilities of AG.
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- 2021
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18. Socio-Economic Deprivation and Symptom Burden in UK Hospice Patients with Advanced Cancer—Findings from a Longitudinal Study
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Mari Lloyd-Williams, Christopher Shiels, Christopher Dowrick, and David Kissane
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socio-economic deprivation ,palliative care ,advanced cancer ,symptom burden ,pain ,depression ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Socio-economic deprivation is known to impact on cancer diagnosis, treatment and access to services, but little is known of the impact of socio-economic deprivation on symptom burden in patients with advanced cancer. Patients with advanced cancer attending hospice day services were recruited into a 24 week longitudinal study. An area-based index of social deprivation was collected along with depression and symptom burden at baseline, 8, 16 and 24 weeks. Of the 595 patients included, with an age range of 33–89 years and a mean age of 68 years, 67% were female, and 37% were diagnosed with cancer in the last 12 months. Twenty nine percent lived in one of the most deprived 20% of neighbourhoods. Patients living in the most socio-economically deprived areas were significantly likely to report receiving insufficient information regarding their cancer at diagnosis (p = 0.007), greater pain (p = 0.02), moderate to severe depression (p = 0.04) and higher global symptom burden (p = 0.04). This study is the first to report that patients with advanced cancer attending hospice services, living in the most deprived neighbourhoods experience significantly greater symptom burden, notably depression and pain. We recommend using patient outcome measures in order to provide targeted support and thereby reduce the increased symptom burden that socio-economically disadvantaged patients experience at the end of life.
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- 2021
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19. An Immunoregulatory Role for Complement Receptors in Murine Models of Breast Cancer
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Fazrena Nadia Md Akhir, Mohd Hezmee Mohd Noor, Keith Weng Kit Leong, Jamileh A. Nabizadeh, Helga D. Manthey, Stefan E. Sonderegger, Jenny Nga Ting Fung, Crystal E. McGirr, Ian A. Shiels, Paul C. Mills, Trent M. Woodruff, and Barbara E. Rolfe
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complement C5a ,complement C3a ,complement receptors ,mammary carcinoma ,immunoregulation ,tumor infiltrating leukocytes ,Immunologic diseases. Allergy ,RC581-607 - Abstract
The complement system has demonstrated roles in regulating tumor growth, although these may differ between tumor types. The current study used two murine breast cancer models (EMT6 and 4T1) to investigate whether pharmacological targeting of receptors for complement proteins C3a (C3aR) and C5a (C5aR1) is protective in murine breast cancer models. In contrast to prior studies in other tumor models, treatment with the selective C5aR1 antagonist PMX53 had no effect on tumor growth. However, treatment of mice with a dual C3aR/C5aR1 agonist (YSFKPMPLaR) significantly slowed mammary tumor development and progression. Examination of receptor expression by quantitative polymerase chain reaction (qPCR) analysis showed very low levels of mRNA expression for either C3aR or C5aR1 by EMT6 or 4T1 mammary carcinoma cell lines compared with the J774 macrophage line or bone marrow-derived macrophages. Moreover, flow cytometric analysis found no evidence of C3aR or C5aR1 protein expression by either EMT6 or 4T1 cells, leading us to hypothesize that the tumor inhibitory effects of the dual agonist are indirect, possibly via regulation of the anti-tumor immune response. This hypothesis was supported by flow cytometric analysis of tumor infiltrating leukocyte populations, which demonstrated a significant increase in T lymphocytes in mice treated with the C3aR/C5aR1 agonist. These results support an immunoregulatory role for complement receptors in primary murine mammary carcinoma models. They also suggest that complement activation peptides can influence the anti-tumor response in different ways depending on the cancer type, the host immune response to the tumor and levels of endogenous complement activation within the tumor microenvironment.
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- 2021
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20. Bioactive Lipids of Marine Microalga Chlorococcum sp. SABC 012504 with Anti-Inflammatory and Anti-Thrombotic Activities
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Katie Shiels, Alexandros Tsoupras, Ronan Lordan, Constantina Nasopoulou, Ioannis Zabetakis, Patrick Murray, and Sushanta Kumar Saha
- Subjects
marine microalga ,Chlorococcum sp. ,bioactive lipid ,anti-inflammatory ,antithrombotic ,platelets ,Biology (General) ,QH301-705.5 - Abstract
Microalgae are at the start of the food chain, and many are known producers of a significant amount of lipids with essential fatty acids. However, the bioactivity of microalgal lipids for anti-inflammatory and antithrombotic activities have rarely been investigated. Therefore, for a sustainable source of the above bioactive lipids, the present study was undertaken. The total lipids of microalga Chlorococcum sp., isolated from the Irish coast, were fractionated into neutral-, glyco-, and phospho-lipids, and were tested in vitro for their anti-inflammatory and antithrombotic activities. All tested lipid fractions showed strong anti-platelet-activating factor (PAF) and antithrombin activities in human platelets (half maximal inhibitory concentration (IC50) values ranging ~25–200 μg of lipid) with the highest activities in glyco- and phospho-lipid fractions. The structural analysis of the bioactive lipid fraction-2 revealed the presence of specific sulfoquinovosyl diacylglycerols (SQDG) bioactive molecules and the HexCer-t36:2 (t18:1/18:1 and 18:2/18:0) cerebrosides with a phytosphingosine (4-hydrosphinganine) base, while fraction-3 contained bioactive phosphatidylcholine (PC) and phosphatidylethanolamine (PE) molecules. These novel bioactive lipids of Chlorococcum sp. with putative health benefits may indicate that marine microalgae can be a sustainable alternative source for bioactive lipids production for food supplements and nutraceutical applications. However, further studies are required towards the commercial technology pathways development and biosafety analysis for the use of the microalga.
- Published
- 2021
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21. Targeting the RhoGEF βPIX/COOL-1 in Glioblastoma: Proof of Concept Studies
- Author
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Kate Connor, David W. Murray, Monika A. Jarzabek, Nhan L. Tran, Kieron White, Patrick Dicker, Kieron J. Sweeney, Philip J. O’Halloran, Brian MacCarthy, Liam P. Shiels, Francesca Lodi, Diether Lambrechts, Jann N. Sarkaria, Raymond M. Schiffelers, Marc Symons, and Annette T. Byrne
- Subjects
glioblastoma ,bevacizumab resistance ,anti-invasive therapy ,RhoGEF ,Beta-Pix/COOL-1 ,ARHGEF7 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Glioblastoma (GBM), a highly invasive and vascular malignancy is shown to rapidly develop resistance and evolve to a more invasive phenotype following bevacizumab (Bev) therapy. Rho Guanine Nucleotide Exchange Factor proteins (RhoGEFs) are mediators of key components in Bev resistance pathways, GBM and Bev-induced invasion. To identify GEFs with enhanced mRNA expression in the leading edge of GBM tumours, a cohort of GEFs was assessed using a clinical dataset. The GEF βPix/COOL-1 was identified, and the functional effect of gene depletion assessed using 3D-boyden chamber, proliferation, and colony formation assays in GBM cells. Anti-angiogenic effects were assessed in endothelial cells using tube formation and wound healing assays. In vivo effects of βPix/COOL-1-siRNA delivered via RGD-Nanoparticle in combination with Bev was studied in an invasive model of GBM. We found that siRNA-mediated knockdown of βPix/COOL-1 in vitro decreased cell invasion, proliferation and increased apoptosis in GBM cell lines. Moreover βPix/COOL-1 mediated endothelial cell migration in vitro. Mice treated with βPix/COOL-1 siRNA-loaded RGD-Nanoparticle and Bev demonstrated a trend towards improved median survival compared with Bev monotherapy. Our hypothesis generating study suggests that the RhoGEF βPix/COOL-1 may represent a target of vulnerability in GBM, in particular to improve Bev efficacy.
- Published
- 2020
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22. Implementing Systems Modelling and Molecular Imaging to Predict the Efficacy of BCL-2 Inhibition in Colorectal Cancer Patient-Derived Xenograft Models
- Author
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Alice C. O’Farrell, Monika A. Jarzabek, Andreas U. Lindner, Steven Carberry, Emer Conroy, Ian S. Miller, Kate Connor, Liam Shiels, Eugenia R. Zanella, Federico Lucantoni, Adam Lafferty, Kieron White, Mariangela Meyer Villamandos, Patrick Dicker, William M. Gallagher, Simon A. Keek, Sebastian Sanduleanu, Philippe Lambin, Henry C. Woodruff, Andrea Bertotti, Livio Trusolino, Annette T. Byrne, and Jochen H. M. Prehn
- Subjects
ABT-199 ,Venetoclax ,colorectal cancer ,BCL-2 ,FOLFOX ,PDX ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Resistance to chemotherapy often results from dysfunctional apoptosis, however multiple proteins with overlapping functions regulate this pathway. We sought to determine whether an extensively validated, deterministic apoptosis systems model, ‘DR_MOMP’, could be used as a stratification tool for the apoptosis sensitiser and BCL-2 antagonist, ABT-199 in patient-derived xenograft (PDX) models of colorectal cancer (CRC). Through quantitative profiling of BCL-2 family proteins, we identified two PDX models which were predicted by DR_MOMP to be sufficiently sensitive to 5-fluorouracil (5-FU)-based chemotherapy (CRC0344), or less responsive to chemotherapy but sensitised by ABT-199 (CRC0076). Treatment with ABT-199 significantly improved responses of CRC0076 PDXs to 5-FU-based chemotherapy, but showed no sensitisation in CRC0344 PDXs, as predicted from systems modelling. 18F-Fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) scans were performed to investigate possible early biomarkers of response. In CRC0076, a significant post-treatment decrease in mean standard uptake value was indeed evident only in the combination treatment group. Radiomic CT feature analysis of pre-treatment images in CRC0076 and CRC0344 PDXs identified features which could phenotypically discriminate between models, but were not predictive of treatment responses. Collectively our data indicate that systems modelling may identify metastatic (m)CRC patients benefitting from ABT-199, and that 18F-FDG-PET could independently support such predictions.
- Published
- 2020
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23. Structural Elucidation of Irish Ale Bioactive Polar Lipids with Antithrombotic Properties
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Alexandros Tsoupras, Ronan Lordan, Eoin O'Keefe, Katie Shiels, Sushanta Kumar Saha, and Ioannis Zabetakis
- Subjects
beer ,CVD ,PAF ,polar lipids ,platelet aggregation ,fatty acids ,Microbiology ,QR1-502 - Abstract
The structures of bioactive polar lipids (PLs) of Irish ale with potent antithrombotic and cardioprotective properties were elucidated. Ale PL was fractionated by preparative thin layer chromatography (TLC) into subclasses, and their antithrombotic effect was assessed against human platelet aggregation induced by the pro-inflammatory mediator, platelet-activating factor (PAF). The fatty acid content and the overall structures of ale PL were elucidated by liquid chromatography mass spectrometry (LC-MS). Phosphatidylcholines (PC) and molecules of the sphingomyelin (SM) family exhibited the strongest anti-PAF effects, followed by phosphatidylethanolamines (PE). PC contained higher amounts of omega-3 polyunsaturated fatty acids (n-3 PUFA) and thus the lowest n-6/n-3 ratio. Bioactive diacyl and alkyl-acyl PC and PE molecules bearing n-3 PUFA at their sn-2 position, especially docosahexaenoic acid (DHA) and α-linolenic acid (ALA) but mostly oleic acid (OA), were identified in both PC and PE subclasses. Eicosapentaenoic acid (EPA) was present only in bioactive PC molecules and not in PE, explaining the lower anti-PAF effects of PE. Bioactive sphingolipid and glycolipid molecules with reported anti-inflammatory and anti-tumour properties, such as specific ceramides and glucosylcerebrosides with sphingosine, phytosphingosine and dihydrosphingosine bases but also specific monogalactodiglycerides and SM species bearing ALA at their sn-2 position, were identified in the SM subclass, providing a rational for its strong bioactivities against the PAF pathway. Further studies are required on the health benefits of bioactive PL from beer and brewery by-products.
- Published
- 2020
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- View/download PDF
24. Inflammation and Premature Ageing in Chronic Kidney Disease
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Thomas Ebert, Sven-Christian Pawelzik, Anna Witasp, Samsul Arefin, Sam Hobson, Karolina Kublickiene, Paul G. Shiels, Magnus Bäck, and Peter Stenvinkel
- Subjects
ageing ,chronic kidney disease ,end-stage kidney disease ,inflammation ,premature ageing ,senescence ,Medicine - Abstract
Persistent low-grade inflammation and premature ageing are hallmarks of the uremic phenotype and contribute to impaired health status, reduced quality of life, and premature mortality in chronic kidney disease (CKD). Because there is a huge global burden of disease due to CKD, treatment strategies targeting inflammation and premature ageing in CKD are of particular interest. Several distinct features of the uremic phenotype may represent potential treatment options to attenuate the risk of progression and poor outcome in CKD. The nuclear factor erythroid 2-related factor 2 (NRF2)–kelch-like erythroid cell-derived protein with CNC homology [ECH]-associated protein 1 (KEAP1) signaling pathway, the endocrine phosphate-fibroblast growth factor-23–klotho axis, increased cellular senescence, and impaired mitochondrial biogenesis are currently the most promising candidates, and different pharmaceutical compounds are already under evaluation. If studies in humans show beneficial effects, carefully phenotyped patients with CKD can benefit from them.
- Published
- 2020
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25. Molecular Characterization of Twenty-Five Marine Cyanobacteria Isolated from Coastal Regions of Ireland
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Katie Shiels, Norma Browne, Fiona Donovan, Patrick Murray, and Sushanta Kumar Saha
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marine cyanobacteria ,morphology ,molecular characterization ,16S rRNA sequence ,isoenzyme banding pattern ,superoxide dismutase (SOD) ,malate dehydrogenase (MDH) ,Biology (General) ,QH301-705.5 - Abstract
Twenty-five marine cyanobacteria isolated from Irish coasts were characterized based on their morphological characters and 16S rRNA gene sequence analysis. In addition, superoxide dismutase (SOD) and malate dehydrogenase (MDH) isoenzyme banding patterns were used to differentiate two morphologically ambiguous isolates. In this study, six new cyanobacteria-specific primers were designed, and a 16S rRNA gene of twenty-five morphologically diverse cyanobacteria was successfully PCR amplified (1198−1396 bps). Assembled 16S rRNA sequences were used both for a basic local alignment search tool (BLAST) analysis for genus-level identification and to generate a phylogenetic tree, which yielded two major clusters: One with morphologically homogenous cyanobacteria and the other with morphologically very diverse cyanobacteria. Kamptonema okenii and Tychonema decoloratum were isolated from a single field sample of Ballybunion and were originally identified as the same ‘Oscillatoria sp.’ based on preliminary morphological observations. However, an alignment of 16S rRNA gene sequences and SOD and MDH isoenzyme banding pattern analyses helped in differentiating the morphologically-indistinguishable ‘Oscillatoria sp.’. Finally, after a re-evaluation of their morphological characters using modern taxonomic publications, the originally identified ‘Oscillatoria sp.’ were re-identified as Kamptonema okenii and Tychonema decoloratum, thus supporting the polyphasic approach of cyanobacteria characterization.
- Published
- 2019
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26. Senescent Cells in Early Vascular Ageing and Bone Disease of Chronic Kidney Disease—A Novel Target for Treatment
- Author
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Sam Hobson, Samsul Arefin, Karolina Kublickiene, Paul G. Shiels, and Peter Stenvinkel
- Subjects
chronic kidney disease ,uremic toxins ,senescence ,Nrf2 ,ageing ,Medicine - Abstract
Together with bone-mineral disorders, premature vascular ageing is a common feature of the uremic phenotype. A detailed understanding of mechanisms involved remains unclear and warrants further research. Available treatment options for end stage renal disease are principally dialysis and organ transplantation, as other treatment alternatives have proven insufficient. Chronic kidney disease (CKD) has been proposed as a model of early vascular and bone ageing, with accumulating evidence supporting the contribution of cellular senescence and the senescence-associated secretory phenotype (SASP) to cardiovascular pathology in CKD. Correspondingly, novel therapies based around the use of senolytic compounds and nuclear factor-erythroid-2-related factor 2 (Nrf2) agonists, have been suggested as attractive novel treatment options. In this review, we detail the contribution of the uremic environment to these processes underpinning ageing and how these relate to vascular health.
- Published
- 2019
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27. In Vitro Antithrombotic Properties of Salmon (Salmo salar) Phospholipids in a Novel Food-Grade Extract
- Author
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Alexandros Tsoupras, Ronan Lordan, Katie Shiels, Sushanta Kumar Saha, Constantina Nasopoulou, and Ioannis Zabetakis
- Subjects
salmon ,polar lipids ,platelet aggregation ,platelet-activating factor (PAF) ,thrombin ,phosphatidylcholine ,phosphatidylethanolamine ,LC-MS ,EPA ,DHA ,PUFA ,phospholipids ,Biology (General) ,QH301-705.5 - Abstract
Marine and salmon polar lipids (PLs) extracted by conventional extractions with non-food-grade solvents (CE-salmon-PLs) possess antithrombotic bioactivities against platelet-activating factor (PAF) and thrombin. Similar effects of food-grade-extracted (FGE) marine PLs have not yet been reported. In this study, food-grade solvents were used to extract PLs from Irish organic farmed salmon (Salmo salar) fillets (FGE-salmon-PLs), while their antithrombotic bioactivities were assessed in human platelets induced by platelet aggregation agonists (PAF/thrombin). FGE-salmon-PLs were further separated by thin layer chromatography (TLC) into lipid subclasses, and the antithrombotic bioactivities of each subclass were also assessed. LC-MS was utilized to elucidate the structure-activity relationships. FGE-salmon-PLs strongly inhibited PAF-induced platelet aggregation, while their relevant anti-thrombin effects were at least three times more potent than the previously reported activities of CE-salmon-PLs. TLC-derived lipid fractions corresponding to phosphatidylcholines (PC) and phosphatidylethanolamines (PE) were the most bioactive lipid subclasses obtained, especially against thrombin. Their LC-MS analysis elucidated that they are diacyl- or alkyl-acyl- PC and PE moieties baring ω3 polyunsaturated fatty acids (PUFA) at their sn-2 position, such as eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA). Our results concerning the potent antithrombotic effects of FGE-salmon-PLs against both PAF and thrombin pathways strongly suggest that such food-grade extracts are putative candidates for the development of novel cardioprotective supplements and nutraceuticals.
- Published
- 2019
- Full Text
- View/download PDF
28. Extracellular Vesicles, Ageing, and Therapeutic Interventions
- Author
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Nikolaos Panagiotou, Ognian Neytchev, Colin Selman, and Paul G. Shiels
- Subjects
ageing ,extracellular vesicles ,microvesicles ,exosomes ,stem cells ,epigenetics ,Cytology ,QH573-671 - Abstract
A more comprehensive understanding of the human ageing process is required to help mitigate the increasing burden of age-related morbidities in a rapidly growing global demographic of elderly individuals. One exciting novel strategy that has emerged to intervene involves the use of extracellular vesicles to engender tissue regeneration. Specifically, this employs their molecular payloads to confer changes in the epigenetic landscape of ageing cells and ameliorate the loss of functional capacity. Understanding the biology of extracellular vesicles and the specific roles they play during normative ageing will allow for the development of novel cell-free therapeutic interventions. Hence, the purpose of this review is to summarise the current understanding of the mechanisms that drive ageing, critically explore how extracellular vesicles affect ageing processes and discuss their therapeutic potential to mitigate the effects of age-associated morbidities and improve the human health span.
- Published
- 2018
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29. Synthesis and Physical Property Characterisation of Spheroidal and Cuboidal Nuclear Waste Simulant Dispersions
- Author
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Jessica Shiels, David Harbottle, and Timothy N. Hunter
- Subjects
inorganic synthesis ,nuclear waste ,caesium phosphomolybdate ,zirconium molybdate ,sedimentation ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
This study investigated dispersions analogous to highly active nuclear waste, formed from the reprocessing of Spent Nuclear Fuel (SNF). Non-radioactive simulants of spheroidal caesium phosphomolybdate (CPM) and cuboidal zirconium molybdate (ZM-a) were successfully synthesised; confirmed via Scanning Electron Microscopy (SEM), powder X-ray diffraction (PXRD) and Fourier transform infrared (FTIR) spectroscopy. In addition, a supplied ZM (ZM-b) with a rod-like/wheatsheaf morphology was also analysed along with titanium dioxide (TiO2). The simulants underwent thermal gravimetric analysis (TGA) and size analysis, where CPM was found to have a D50 value of 300 nm and a chemical formula of Cs3PMo12O40·13H2O, ZM-a a D50 value of 10 μm and a chemical formula of ZrMo2O7(OH)2·3H2O and ZM-b to have a D50 value of 14 μm and a chemical formula of ZrMo2O7(OH)2·4H2O. The synthesis of CPM was tracked via Ultraviolet-visible (UV-Vis) spectroscopy at both 25 °C and 50 °C, where the reaction was found to be first order with the rate constant highly temperature dependent. The morphology change from spheroidal CPM to cuboidal ZM-a was tracked via SEM, reporting to take 10 days. For the onward processing and immobilisation of these waste dispersions, centrifugal analysis was utilised to understand their settling behaviours, in both aqueous and 2 M nitric acid environments (mimicking current storage conditions). Spheroidal CPM was present in both conditions as agglomerated clusters, with relatively high settling rates. Conversely, the ZM were found to be stable in water, where their settling rate exponents were related to the morphology. In acid, the high effective electrolyte resulted in agglomeration and faster sedimentation.
- Published
- 2018
- Full Text
- View/download PDF
30. Bioremediation of Aluminium from the Waste Water of a Conventional Water Treatment Plant Using the Freshwater Macroalga Oedogonium
- Author
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David A. Roberts, Laura Shiels, Julian Tickle, Rocky de Nys, and Nicholas A. Paul
- Subjects
conventional water treatment ,bioremediation ,macroalgae ,aluminium ,alum ,coagulation ,flocculent ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
Conventional water treatment processes use aluminium sulphate (alum) as a coagulant in the production of potable water. While alum is an inexpensive and reliable means of treating water, the process generates waste water containing dissolved Al. This waste water is primarily dealt with via on-site retention. In this study we investigate the cultivation of the freshwater macroalga Oedogonium as a means to sequester dissolved Al from waste water from a conventional water treatment plant. Furthermore, we examine the use of CO2 to manipulate the pH of cultivation as a means of enhancing the sequestration of Al by either increasing the productivity of Oedogonium or increasing the bioavailability of Al in the waste water. The relative bioavailability of Al under conditions of CO2 and no-CO2 provision was contrasted by comparing Al uptake by Diffusive Gradients in Thin Films (DGTs). Oedogonium was able to grow rapidly in the waste water (12 g dry weight m−2 day−1) while consistently sequestering Al. The Oedogonium-treated waste water had a sufficiently low Al concentration that it could be used in unrestricted irrigation in the surrounding region. When CO2 was added to the waste water containing concentrations of Al up to 8 mg L−1, there was a slight increase (~10%) in the rate of sequestration of Al by Oedogonium relative to waste water not receiving CO2. This was due to two concurrent processes. The provision of CO2 increased the productivity of Oedogonium by 15% and the bioavailability of Al by up to 200%, as measured by the DGTs. Despite this strong effect of CO2 on Al bioavailability, the increase in Al sequestration by Oedogonium when CO2 was provided was modest (~10%). Al was sequestered by Oedogonium to concentrations below permissible limits for discharge without the need for the addition CO2. The cultivation of Oedogonium in waste water from conventional treatments plants can simultaneously treat waste water for re-use and provide a biomass source for value-added applications.
- Published
- 2018
- Full Text
- View/download PDF
31. Cysteine Proteinase C1A Paralog Profiles Correspond with Phylogenetic Lineages of Pathogenic Piroplasmids
- Author
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Mariano E. Ascencio, Monica Florin-Christensen, Choukri B. Mamoun, William Weir, Brian Shiels, and Leonhard Schnittger
- Subjects
cysteine proteinases ,C1A cysteine-proteinases ,piroplasmids ,Theileria ,Babesia ,Cytauxzoon ,taxonomy ,molecular phylogeny ,comparative genomics ,evolutionary genomics ,Veterinary medicine ,SF600-1100 - Abstract
Piroplasmid parasites comprising of Babesia, Theileria, and Cytauxzoon are transmitted by ticks to farm and pet animals and have a significant impact on livestock industries and animal health in tropical and subtropical regions worldwide. In addition, diverse Babesia spp. infect humans as opportunistic hosts. Molecular phylogeny has demonstrated at least six piroplasmid lineages exemplified by B. microti, B. duncani, C. felis, T. equi, Theileria sensu stricto (T. annulata, T. parva, and T. orientalis) and Babesia sensu stricto (B. bovis, B. bigemina, and B. ovis). C1A cysteine-proteinases (C1A-Cp) are papain-like enzymes implicated in pathogenic and vital steps of the parasite life cycle such as nutrition and host cell egress. An expansion of C1A-Cp of T. annulata and T. parva with respect to B. bovis and B. ovis was previously described. In the present work, C1A-Cp paralogs were identified in available genomes of species pertaining to each piroplasmid lineage. Phylogenetic analysis revealed eight C1A-Cp groups. The profile of C1A-Cp paralogs across these groups corroborates and defines the existence of six piroplasmid lineages. C. felis, T. equi and Theileria s.s. each showed characteristic expansions into extensive families of C1A-Cp paralogs in two of the eight groups. Underlying gene duplications have occurred as independent unique evolutionary events that allow distinguishing these three piroplasmid lineages. We hypothesize that C1A-Cp paralog families may be associated with the advent of the schizont stage. Differences in the invertebrate tick host specificity and/or mode of transmission in piroplasmid lineages might also be associated with the observed C1A-Cp paralog profiles.
- Published
- 2018
- Full Text
- View/download PDF
32. Telomere Homeostasis: Interplay with Magnesium
- Author
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Donogh Maguire, Ognian Neytchev, Dinesh Talwar, Donald McMillan, and Paul G. Shiels
- Subjects
telomeres ,telomerase ,TERT ,mitochondria ,oxidative stress ,magnesium ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Telomere biology, a key component of the hallmarks of ageing, offers insight into dysregulation of normative ageing processes that accompany age-related diseases such as cancer. Telomere homeostasis is tightly linked to cellular metabolism, and in particular with mitochondrial physiology, which is also diminished during cellular senescence and normative physiological ageing. Inherent in the biochemistry of these processes is the role of magnesium, one of the main cellular ions and an essential cofactor in all reactions that use ATP. Magnesium plays an important role in many of the processes involved in regulating telomere structure, integrity and function. This review explores the mechanisms that maintain telomere structure and function, their influence on circadian rhythms and their impact on health and age-related disease. The pervasive role of magnesium in telomere homeostasis is also highlighted.
- Published
- 2018
- Full Text
- View/download PDF
33. Segmental Aging Underlies the Development of a Parkinson Phenotype in the AS/AGU Rat
- Author
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Sohair M. Khojah, Anthony P. Payne, Dagmara McGuinness, and Paul G. Shiels
- Subjects
AS/AGU rat ,sirtuins ,p16Ink4a ,SA-β-Gal ,senescence ,brain ,Parkinson’s disease ,Cytology ,QH573-671 - Abstract
There is a paucity of information on the molecular biology of aging processes in the brain. We have used biomarkers of aging (SA β-Gal, p16Ink4a, Sirt5, Sirt6, and Sirt7) to demonstrate the presence of an accelerated aging phenotype across different brain regions in the AS/AGU rat, a spontaneous Parkinsonian mutant of PKCγ derived from a parental AS strain. P16INK4a expression was significantly higher in AS/AGU animals compared to age-matched AS controls (p < 0.001) and displayed segmental expression across various brain regions. The age-related expression of sirtuins similarly showed differences between strains and between brain regions. Our data clearly show segmental aging processes within the rat brain, and that these are accelerated in the AS/AGU mutant. The accelerated aging, Parkinsonian phenotype, and disruption to dopamine signalling in the basal ganglia in AS/AGU rats, suggests that this rat strain represents a useful model for studies of development and progression of Parkinson’s disease in the context of biological aging and may offer unique mechanistic insights into the biology of aging.
- Published
- 2016
- Full Text
- View/download PDF
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