625 research outputs found

    The pH and ionic composition of the sub-embryonic fluid of the Japanese quail (Coturnix c. japonica)

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    The current theory of acid-base chemistry regards [H+] as a dependent variable: changes in pH of a fluid can only occur by alteration of strong ion concentrations ([Na+], [K+], [Cl-]). The objective of this study was to determine whether manipulation of sub-embryonic fluid strong ion composition would alter [H+] in the direction predicted by theory. Changes to fluid strong ion concentrations decreased pH in the way predicted and the changes in Cl- suggest a passive distribution. Also, changes in organic anions suggest an essential role for these in acid-base chemistry of this fluid. It was notable that both Na and HCO3- were unaffected by the treatments emphasising the importance of these two ions in fluid production by the quail blastoderm

    Evaluation of a theory-informed implementation of a nursing discharge teaching intervention for older adults.

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    To evaluate the implementation process of a multi-site trial of a novel discharge teaching intervention. Hybrid type 3 trial. A discharge teaching intervention for older adults was implemented in medical units from August 2020 to August 2021 with 30 nurse participants. The implementation process was guided by behaviour change frameworks. Outcome data comprised determinants of nurses' behaviours related to teaching and the acceptability, appropriateness, feasibility of the intervention and frequency of teaching activities received by the participants. This study adheres to StaRI and TIDieR reporting guidelines. Twelve of 18 determinants of nurses' behaviour domains improved post-implementation. Being trained reinforced nurses' knowledge and skills in patient teaching. Practicing the intervention increased their awareness on the gaps between evidence-based teaching principles and their actual practice. The intervention was considered acceptable and moderately appropriate and feasible. A theoretically informed implementation process can influence nurses' perceptions and behaviours related to discharge teaching by targeting specific behaviour domains. Practice change to improve discharge teaching will require organizational support from nursing management. Although the conceptual foundations of the intervention tested in this study were informed by the priorities and experience of patients, this population was not directly involved in the design and conduct of the study. ClinicalTrials.gov: NCT04253665

    Neuropilins 1 and 2 mediate neointimal hyperplasia and re-endothelialization following arterial injury

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    AIMS: Neuropilins 1 and 2 (NRP1 and NRP2) play crucial roles in endothelial cell migration contributing to angiogenesis and vascular development. Both NRPs are also expressed by cultured vascular smooth muscle cells (VSMCs) and are implicated in VSMC migration stimulated by PDGF-BB, but it is unknown whether NRPs are relevant for VSMC function in vivo. We investigated the role of NRPs in the rat carotid balloon injury model, in which endothelial denudation and arterial stretch induce neointimal hyperplasia involving VSMC migration and proliferation. METHODS AND RESULTS: NRP1 and NRP2 mRNAs and proteins increased significantly following arterial injury, and immunofluorescent staining revealed neointimal NRP expression. Down-regulation of NRP1 and NRP2 using shRNA significantly reduced neointimal hyperplasia following injury. Furthermore, inhibition of NRP1 by adenovirally overexpressing a loss-of-function NRP1 mutant lacking the cytoplasmic domain (ΔC) reduced neointimal hyperplasia, whereas wild-type (WT) NRP1 had no effect. NRP-targeted shRNAs impaired, while overexpression of NRP1 WT and NRP1 ΔC enhanced, arterial re-endothelialization 14 days after injury. Knockdown of either NRP1 or NRP2 inhibited PDGF-BB-induced rat VSMC migration, whereas knockdown of NRP2, but not NRP1, reduced proliferation of cultured rat VSMC and neointimal VSMC in vivo. NRP knockdown also reduced the phosphorylation of PDGFα and PDGFβ receptors in rat VSMC, which mediate VSMC migration and proliferation. CONCLUSION: NRP1 and NRP2 play important roles in the regulation of neointimal hyperplasia in vivo by modulating VSMC migration (via NRP1 and NRP2) and proliferation (via NRP2), independently of the role of NRPs in re-endothelialization

    Emerging Roles for Neuropilin-2 in Cardiovascular Disease

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    Cardiovascular disease, the leading cause of death worldwide, is predominantly associated with atherosclerosis. Atherosclerosis is a chronic inflammatory disease characterised by the narrowing of large to medium-sized arteries due to a build-up of plaque. Atherosclerotic plaque is comprised of lipids, extracellular matrix, and several cell types, including endothelial, immune, and vascular smooth muscle cells. Such narrowing of the blood vessels can itself restrict blood flow to vital organs but most severe clinical complications, including heart attacks and strokes, occur when lesions rupture, triggering the blood to clot and obstructing blood flow further down the vascular tree. To circumvent such obstructions, percutaneous coronary intervention or bypass grafts are often required; however, re-occlusion of the treated artery frequently occurs. Neuropilins (NRPs), a multifunctional family of cell surface co-receptors, are expressed by endothelial, immune, and vascular smooth muscle cells and are regulators of numerous signalling pathways within the vasculature. Here, we review recent studies implicating NRP2 in the development of occlusive vascular diseases and discuss how NRP2 could be targeted for therapeutic intervention

    VEGF (Vascular Endothelial Growth Factor) Induces NRP1 (Neuropilin-1) Cleavage via ADAMs (a Disintegrin and Metalloproteinase) 9 and 10 to Generate Novel Carboxy- Terminal NRP1 Fragments That Regulate Angiogenic Signaling

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    OBJECTIVE: NRP1(neuropilin-1) acts as a coreceptor for VEGF (vascular endothelial growth factor) with an essential role in angiogenesis. Recent findings suggest that posttranslational proteolytic cleavage of VEGF receptors may be an important mechanism for regulating angiogenesis, but the role of NRP1 proteolysis and the NRP1 species generated by cleavage in endothelial cells is not known. To characterize NRP1 proteolytic cleavage in endothelial cells, determine the mechanism, and investigate the role of NRP1 cleavage in regulation of endothelial cell function. APPROACH AND RESULTS: NRP1 species comprising the carboxy (C)-terminal and transmembrane NRP1 domains but lacking the ligand-binding A and B regions are constitutively expressed in endothelial cells. Generation of these C-terminal domain NRP1 proteins is upregulated by phorbol ester and Ca2+ ionophore, and reduced by pharmacological inhibition of metalloproteinases, by small interfering RNA-mediated knockdown of 2 members of ADAM (a disintegrin and metalloproteinase) family, ADAMs 9 and 10, and by a specific ADAM10 inhibitor. Furthermore, VEGF upregulates expression of these NRP1 species in an ADAM9/10-dependent manner. Transduction of endothelial cells with adenoviral constructs expressing NRP1 C-terminal domain fragments inhibited VEGF-induced phosphorylation of VEGFR2 (VEGF receptor tyrosine kinase)/KDR and decreased VEGF-stimulated endothelial cell motility and angiogenesis in coculture and aortic ring sprouting assays. CONCLUSIONS: These findings identify novel NRP1 species in endothelial cells and demonstrate that regulation of NRP1 proteolysis via ADAMs 9 and 10 is a new regulatory pathway able to modulate VEGF angiogenic signaling

    Optical Detection of Paramagnetic Defects in a CVD-grown Diamond

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    The electronic spins of the nitrogen-vacancy centers (NV centers) in Chemical-Vapor-Deposition (CVD) grown diamonds form ideal probes of magnetic fields and temperature, as well as promising qu-bits for quantum information processing. Studying and controlling the magnetic environment of NV centers in such high purity crystals is thus essential for these applications. We demonstrate optical detection of paramagnetic species, such as hydrogen-related complexes, in a CVD-grown diamond. The resonant transfer of the NV centers' polarized electronic spins to the electronic spins of these species generates conspicuous features in the NV photoluminescence by employing magnetic field scans along the [100] crystal direction. Our results offer prospects for more detailed studies of CVD-grown processes as well as for coherent control of the spin of novel classes of hyper-polarized paramagnetic species.Comment: 8 pages including appendi

    Applying Moral Development Literature And Ethical Theories To The Administration Of Taxes In Kosovo

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    The population of Kosovo had suffered years of abuse, ethnic cleansing, turmoil, human atrocities, and constant conflict - the results of which plunged Kosovo into costly war. Following the war Kosovo was placed under the protection of the United Nations in 1999. Kosovo received many years of support and developmental assistance from the international community and became a sovereign nation in February 2008. It was very important for Kosovo’s government to serve the needs of the people without continued oversight and intervention by the United Nations. Public institutions are vital to the success of the government. There is no institution more important to the successful development of a sovereign nation and their economy than the ethical administration of a tax authority. In the spring of 2008, after Kosovo’s declaration of independence, this study was initiated to determine the moral maturity of the members of the Tax Authority of Kosovo. This study provides a review of the current situation in Kosovo and discusses ethical considerations in tax administration. The paper further provides a comprehensive discussion of ethical concerns and discusses the importance of moral development in the tax administration of Kosovo. Recommendations for managers and future research are presented

    Microporous Biodegradable Films Promote Therapeutic Angiogenesis

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    Peripheral arterial disease and critical limb ischemia are common symptoms of cardiovascular disease. Vascular surgery is used to create a bypass around occluded blood vessels to improve blood flow to ischemic muscle, thus avoiding the need for amputation. Attempts to vascularize tissues by therapeutic angiogenesis using delivery of exogenous angiogenic agents are underwhelming. A material-based approach that provides an endogenous stimulus capable of promoting angiogenesis and increased tissue perfusion would provide a paradigm shift in treatment options available. It is reported here that microporous biodegradable films produced using thermally induced phase separation provide a localized biophysical stimulus of proangiogenic genes in vivo that is associated with increased blood vessel density and restoration of blood flow to ischemic tissue. These findings show, for the first time, that acellular, nonfunctionalized biodegradable biomaterials can provide an innovative, material-based approach for therapeutic angiogenesis to enhance tissue reperfusion in vivo
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