482 research outputs found

    Phage Therapy and Development of Delivery Systems for Gram-Positive Phage Endolysins

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    This thesis focussed on Gram positive phages and their endolysins. Here, two similar kay-like staphylococcal phages B1 (vB_SauM_B1) and JA1 (vB_SauM_JA1) were isolated from a commercial therapeutic phage mix. Their host range was established on the Irish National MRSA bank, which included twenty one sequence types in addition relevant control strains. Based on this, distinct phages were identified and subjected to genome sequencing. The sequences were compared with the sequence of phage K (vB_SauM_K), which was also determined in this work. All three phages had a genome size of at least 139 kb, although some key differences were identified between each. The new phages B1 and JA1 possessed double stranded DNA and generally had a broader host range than phage K. A comparative genomic analysis on the phage genomes identified several (open reading frames) ORFs that were absent in the genome of phage K but present in genomes of phages B1 and JA1. One of the cloned genes from phage K was shown to encode a protein for the receptor-binding-protein and this protein was demonstrated to slightly inhibit phage adsorption. The other cloned gene encoded the phage endolysin and this peptidoglycan hydrolase were identical across all three phages and thus, the CHAPk endolysin of phage K was chosen to demonstrate the application of the endolysin for the control of staphylococci in milk. A two-log reduction in staphylococcal numbers in milk was observed. When the endolysin was introduced into a lactococcal secretion system using the pNZ8048 vector, detectable secretion was successfully demonstrated. Simultaneously, a Clostridium difficile phage endolysin, an amidase, was also cloned into the same secretion system with successful secretion also being demonstrated. In addition, this latter endolysin was also secreted from a recombinant E. coli strain, suggesting potential applications for delivery of the endolysin to the intestine from a hypothetical probiotic E. coli strain

    Interfering with the CCL2–glycosaminoglycan axis as a potential approach to modulate neuroinflammation

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    Multiple Sclerosis, a chronic inflammatory demyelinating disease of the central nervous system, involves an increased expression of monocyte chemotactic protein 1 MCP1-/CCL2. For exerting its chemotactic effects, chemokine binding to glycosaminoglycans (GAGs) is required and therefore this interaction represents a potential target for therapeutic intervention. We have designed an anti inflammatory decoy variant, Met-CCL2 (Y13AS21K Q23R), embodying increased affinity for GAGs as well as knocked out GPCR activation properties. This non-signalling dominant-negative mutant is shown here to be able to displace wild type CCL2 from GAGs by which it is supposed to interfere with the chemokine-related inflammatory response. In vivo, the anti-inflammatory properties were successfully demonstrated in a murine model of zymosan-induced peritonitis as well as in an experimental autoimmune encephalomyelitis, a model relevant for multiple sclerosis, where the compound lead to significantly reduced clinical scores due to reduction of cellular infiltrates and demyelination in spinal cord and cerebellum. These findings indicate a promising potential for future therapeutic development

    On the application of YOLO‑based object detection models to classify and detect defects in laser‑directed energy deposition process

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    Reducing the defects in the additively manufactured components using Laser-Directed Energy Deposition (L-DED) process is important for ensuring structural integrity, surface quality, and functional performance. The first required step for reducing defects in the L-DED manufactured components is the identification and understanding of the type of defects using the object detection approach. This paper aims to use a YOLO-based object detection models to classify and detect defects in the horizontal wall, vertical wall, and cuboid structures manufactured using various combinations of L-DED process parameters. The objectives involved are training, testing and validating of YOLOv7, YOLOv8, YOLOv9, and YOLOv9-GELAN models on the independent dataset of defects such as flash formation, void and rough texture, identifying the best YOLO model capable of detecting small and big size multiple defects within a single image and comparing the defects captured by YOLO model with previously used conventional CNN model such as VGG16. The results revealed that YOLOv9-GELAN exhibited good performance indicators compared to other YOLO models. The increasing trend for mAP0.5:0.95 signifies YOLOv9- GELAN as a good choice for defect detection of multiple defects in a single image. It also gave mAP of 95.7%, precision of 94%, recall of 96%, and F1-score of 90%, indicating accuracy in defect localisation and classification with minimal false positives and negatives. These high values for YOLOv9-GELAN indicate its capability to accurately highlight the defects using the bounding box compared to the previously proposed VGG16 model. In addition, YOLOv9-GELAN capability of processing 62 images per second showed its potential for higher frames processing compared to other YOLO models. This research will progress the development of AI-based in-situ defect monitoring for the L-DED process

    Invariant natural killer T cells act as an extravascular cytotoxic barrier for joint-invading Lyme Borrelia

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    SignificanceInvariant natural killer T cells (iNKT) have been found primarily patrolling inside blood vessels in the liver, where they respond to bacterial glycolipids presented by CD1d on liver macrophages. We show joint iNKT cells are localized outside of blood vessels and respond directly to the joint-homing pathogen, Borrelia burgdorferi, which causes Lyme borreliosis using multichannel spinning-disk intravital microscopy. These iNKT cells interacted with B. burgdorferi at the vessel wall and disrupted its dissemination attempts into joints. Successful penetrance of B. burgdorferi out of the vasculature and into the joint tissue was met by a lethal attack by extravascular iNKT cells through a granzyme-dependent pathway. These results suggest a critical extravascular iNKT cell immune surveillance in joints that functions as a cytotoxic barrier

    Planetary health benefits from strengthening health workforce education on the social determinants of health.

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    Social inequalities are perpetuating unhealthy living and working conditions and behaviours. These causes are commonly called 'the social determinants of health'. Social inequalities are also impacting climate change and vice-versa, which, is causing profound negative impacts on planetary health. Achieving greater sustainability for human and planetary health demands that the health sector assumes a greater leadership role in addressing social inequalities. This requires equipping health and social care workers to better understand how the social determinants of health impact patients and communities. Integration of the social determinants of health into education and training will prepare the workforce to adjust clinical practice, define appropriate public health programmes and leverage cross-sector policies and mechanisms being put in place to address climate change. Educators should guide health and social workforce learners using competency-based approaches to explore critical pathways of social determinants of health, and what measurements and interventions may apply according to the structural and intermediary determinants of health and health equity. Key institutional and instructional reforms by decision-makers are also needed to ensure that the progressive integration and strengthening of education and training on the social determinants of health is delivered equitably, including by ensuring the leadership and participation of marginalized and minority groups. Training on the social determinants of health should apply broadly to three categories of health and social workforce learners, namely, those acting on global or national policies; those working in districts and communities; and those providing clinical services to individual families and patients

    Gender-differences of in vitro colonic motility after chemo- and radiotherapy in humans.

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    Background: The aim of the present in vitro study was to investigate, in different genders, motor responses in surgical colonic specimens from patients with rectal cancer undergoing and not undergoing chemotherapy with capecitabine and radiotherapy. Methods: This in vitro study was conducted from October 2015 to August 2017 at the Experimental Pharmacology Laboratory at the National Institute “S. de Bellis” after collecting samples at the Department of Surgery. Segments of sigmoid colon were obtained from 15 patients (Male (M)/Female (F) = 8/7; control group, CG) operated on for elective colorectal resection for rectal cancer without obstruction and 14 patients (M/F = 7/7; study group, SG) operated on for elective colorectal resection for rectal cancer who also received chemotherapy, based on capecitabine twice daily, and radiotherapy. Isometric tension was measured on colonic circular muscle strips exposed to increasing carbachol or histamine concentrations to obtain concentration-response curves. The motor responses to electrically evoked stimulation were also investigated. Results: In males, carbachol and histamine caused concentration-dependent contractions in the CG and SG. An increased sensitivity and a higher response to carbachol and histamine were observed in SG than CG (P < 0.01). On the contrary, in females, the response to carbachol was not significantly different in CG from the SG and the maximal responses to carbachol were greater in CG than in SG (P < 0.001). The same applied to histamine for half-maximal effective concentrations and maximal response in that they were not significantly different in CG from the SG. Electrically evoked contractions were significantly more pronounced in males, especially in the SG (P < 0.05). Conclusions: This preliminary in vitro study has shown gender differences in motor responses of colonic circular muscle strips in patients who had received chemotherapy with capecitabine and radiotherapy

    Concise Review: Mesenchymal Stem Cells for Acute Lung Injury: Role of Paracrine Soluble Factor

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    Morbidity and mortality have declined only modestly in patients with clinical acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), despite extensive research into the pathophysiology. Current treatment remains primarily supportive with lung-protective ventilation and a fluid conservative strategy. Pharmacologic therapies that reduce the severity of lung injury in preclinical models have not yet been translated to effective clinical treatment options. Consequently, further research in translational therapies is needed. Cell-based therapy with mesenchymal stem cells (MSCs) is one attractive new therapeutic approach. MSCs have the capacity to secrete multiple paracrine factors that can regulate endothelial and epithelial permeability, decrease inflammation, enhance tissue repair, and inhibit bacterial growth. This review will focus on recent studies, which support the potential therapeutic use of MSCs in ALI/ARDS, with an emphasis on the role of paracrine soluble factors

    Bone marrow stromal cells attenuate sepsis via prostaglandin E2— dependent reprogramming of host macrophages to increase their interleukin-10 production

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    Sepsis causes over 200,000 deaths yearly in the US; better treatments are urgently needed. Administering bone marrow stromal cells (BMSCs—also known as mesenchymal stem cells) to mice before or shortly after inducing sepsis by cecal ligation and puncture reduced mortality and improved organ function. The beneficial effect of BMSCs was eliminated by macrophage depletion or pretreatment with antibodies specific for interleukin-10 (IL-10) or IL-10 receptor. Monocytes and/ or macrophages from septic lungs made more IL-10 when prepared from mice treated with BMSCs versus untreated mice. Lipopolysaccharide (LPS)-stimulated macrophages produced more IL-10 when cultured with BMSCs, but this effect was eliminated if the BMSCs lacked the genes encoding Toll-like receptor 4, myeloid differentiation primary response gene-88, tumor necrosis factor (TNF) receptor-1a or cyclooxygenase-2. Our results suggest that BMSCs (activated by LPS or TNF-α) reprogram macrophages by releasing prostaglandin E2 that acts on the macrophages through the prostaglandin EP2 and EP4 receptors. Because BMSCs have been successfully given to humans and can easily be cultured and might be used without human leukocyte antigen matching, we suggest that cultured, banked human BMSCs may be effective in treating sepsis in high-risk patient groups.Sepsis, a serious medical condition that affects 18 million people per year worldwide, is characterized by a generalized inflammatory state caused by infection. Widespread activation of inflammation and coagulation pathways progresses to multiple organ dysfunction, collapse of the circulatory system (septic shock) and death. Because as many people die of sepsis annually as from acute myocardial infarction1, a new treatment regimen is desperately needed. In the last few years, it has been discovered that BMSCs are potent modulators of immune responses2-5. We wondered whether such cells could bring the immune response back into balance, thus attenuating the underlying pathophysiology that eventually leads to severe sepsis, septic shock and death6,7. As a model of sepsis, we chose cecal ligation and puncture (CLP), a procedure that has been used for more than two decades8. This mouse model closely resembles the human disease: it has a focal origin (cecum), is caused by multiple intestinal organisms, and results in septicemia with release of bacterial toxins into the circulation. With no treatment, the majority of the mice die 24-48 h postoperatively. Originally published Nature Medicine, Vol. 15, No. 1, Jan 200
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