Publications by authors named "Adrian Chester"

Objectives: As part of a wider study, our aim was to elicit perspectives of people with congenital heart disease (CHD) and/or their parents/carers about their experiences of healthcare and what is important to them when receiving care.

Design And Setting: A qualitative study involving a series of closed, asynchronous, online discussion forums underpinned by an interpretivist framework and set up and moderated by three patient charities via their Facebook pages.

Participants: People with CHD and parents/carers of people with CHD from the UK.

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Delayed wound healing is a major complication that diabetic patients suffer from due to high microbial infection susceptibility, high diabetic wound alkalinity, a low lymphangiogenesis rate, and a high inflammation rate, resulting in severe gangrene. Hence, this study aims to develop a multifunctional adhesive nanofibrous patch to promote the wound healing process. Phenytoin, sildenafil citrate, and/or nitric oxide-eluting nanoparticles were incorporated separately within the polylactic acid nanofibrous layer.

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Heart valve disease is a major cause of mortality and morbidity worldwide with no effective medical therapy and no ideal valve substitute emulating the extremely sophisticated functions of a living heart valve. These functions influence survival and quality of life. This has stimulated extensive attempts at tissue engineering "living" heart valves.

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Mycelia were cultivated from a Thai wild mushroom identified as Ganoderma australe based on polymerase chain reaction (PCR) and morphological analyses. The mycelial extracts were examined for their active ingredients using a liquid chromatography-tandem mass spectrometry (LC‒MS/MS) method. This revealed the presence of lovastatin and tentative compounds including p-coumaric, nicotinamide, gamma-aminobutyric acid, choline, nucleosides, amino acids, and saccharides.

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The 2016 Albert Lasker Basic Medical Research Award and subsequently the 2019 Nobel Prize in Physiology or Medicine were awarded to William Kaelin, Jr., Sir Peter Ratcliffe, and Gregg Semenza for their work on how cells sense and adapt to hypoxic conditions. Their work showed that the changes in gene expression, cell metabolism, and tissue remodelling that occur in response to low oxygen concentrations are orchestrated by the transcription factor, hypoxia inducible factor-1 (HIF-1).

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Calcific aortic valve disease affects the aortic side of the valve, exposed to low magnitude multidirectional ("disturbed) blood flow, more than it affects the ventricular side, exposed to high magnitude uniaxial flow. Overt disease is preceded by endothelial dysfunction and inflammation. Here we investigate the potential role of the transforming growth factor-β (TGF-β) receptor ALK5 in this process.

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Statins are now one of the most prescribed drugs in the world and have made a major impact to the prevention and treatment of cardiovascular disease, thereby extending the lives of millions of people across the world. The scientist responsible for the discovery of the first statin, Professor Akira Endo, was recently honoured for his 'exceptional contribution to cardiovascular medicine' by award of the European Society of Cardiology Gold Medal in 2021. Inspired by the work of Sir Alexander Fleming as a young scientist, Professor Endo pursued a long research career focusing on fungal enzymes and their potential use in medicine; a journey that eventually led him to the discovery of statins.

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Cardiac valves exhibit highly complex structures and specialized functions that include dynamic interactions between cells, extracellular matrix (ECM) and their hemodynamic environment. Valvular gene expression is tightly regulated by a variety of mechanisms including epigenetic factors such as histone modifications, RNA-based mechanisms and DNA methylation. To date, methylation fingerprints of non-diseased human aortic and mitral valves have not been studied.

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Objective: We have previously reported that human calcified aortic cusps have abundant expression of smooth muscle (SM) markers and co-activators. We hypothesised that cells in bicuspid aortic valve (BAV) cusps and those affected by rheumatic heart valve (RHV) disease may follow a similar phenotypic transition into smooth muscle cells, a process that could be regulated by transforming growth factors (TGFs).

Aims: Cusps from eight patients with BAV and seven patients with RHV were analysed for early and late SM markers and regulators of SM gene expression by immunocytochemistry and compared to healthy aortic valves from 12 unused heart valve donors.

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The success of tissue-engineered heart valves rely on a balance between polymer degradation, appropriate cell repopulation, and extracellular matrix (ECM) deposition, in order for the valves to continue their vital function. However, the process of remodeling is highly dynamic and species dependent. The carbon fibers have been well used in the construction industry for their high tensile strength and flexibility and, therefore, might be relevant to support tissue-engineered hearts valve during this transition in the mechanically demanding environment of the circulation.

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A significant amount of knowledge has been gained with the use of cell-based assays to elucidate the mechanisms that mediate heart valve calcification. However, cells used in these studies lack their association with the extra-cellular matrix or the influence of other cellular components of valve leaflets. We have developed a model of calcification using intact porcine valve leaflets, that relies upon a biological stimulus to drive the formation of calcified nodules within the valve leaflets.

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Calcific aortic valve disease (CAVD) is an athero-inflammatory process. Growing evidence supports the inflammation-driven calcification model, mediated by cytokines such as interferons (IFNs) and tumor necrosis factor (TNF)-α. Our goal was investigating IFNs' effects in human aortic valve endothelial cells (VEC) and the potential differences between aortic (aVEC) and ventricular (vVEC) side cells.

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CD4 T cells expressing choline acetyltransferase (ChAT) have recently been shown to cause a drop in systemic blood pressure when infused into mice. The aim of this study was to determine if ChAT-expressing T cells could regulate coronary vascular reactivity. Preconstricted segments of epicardial and intramyocardial porcine coronary arteries relaxed in response to Jurkat T cells (JT) that overexpressed ChAT (JT cells).

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Objectives: Globally, healthcare systems have been stretched to the limit by the COVID-19 pandemic. Significant changes have had to be made to the way in which non-COVID-19-related care has been delivered. Our objective was to understand, from the perspective of patients with a chronic, life-long condition (congenital heart disease, CHD) and their parents/carers, the impact of COVID-19 on the delivery of care, how changes were communicated and whether healthcare providers should do anything differently in a subsequent wave of COVID-19 infections.

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Elevated serum concentrations of leucine-rich α-2-glycoprotein (LRG1) have been reported in patients with inflammatory, autoimmune, and cardiovascular diseases. This study aims to investigate the role of LRG1 in endothelial activation. LRG1 in endothelial cells (ECs) of arteries and serum of patients with critical limb ischemia (CLI) was assessed by immunohistochemistry and ELISA, respectively.

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Background: The ability of heart valve cells to respond to their mechanical environment represents a key mechanism by which the integrity and function of valve cusps is maintained. A number of different mechanotransduction pathways have been implicated in the response of valve cells to mechanical stimulation. In this study, we explore the expression pattern of several mechanosensitive ion channels (MSC) and their potential to mediate mechanosensitive responses of human valve interstitial cells (VIC).

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Over the last 20 years, the designs of tissue engineered heart valves have evolved considerably. An initial focus on replicating the mechanical and structural features of semilunar valves has expanded to endeavors to mimic the biological behavior of heart valve cells as well. Studies on the biology of heart valves have shown that the function and durability of native valves is underpinned by complex interactions between the valve cells, the extracellular matrix, and the mechanical environment in which heart valves function.

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Cardiac regeneration post-injury is a tantalizing feature of many lower vertebrates such as fishes and urodeles, but absent in adult humans. Restoration of pumping function is a key endpoint of cardiac regeneration, but very little is known about the biomechanical remodeling process. Here, we quantify and compare the evolution of cellular composition and mechanical stiffness of the zebrafish ventricular myocardium during maturation and following cryoinjury during regeneration to better understand the dynamics of biomechanical remodeling during these two processes.

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Background: The calcific aortic valve disease (CAVD) is a common heart pathology that involves inflammation, fibrosis, and calcification of aortic valve leaflets. All these processes could be affected by changes in the extracellular purinergic signaling that depend on the activity of ectonucleotidases, mainly ectonucleoside triphosphate diphosphohydrolase 1 (CD39, eNTPD1) and ecto-5'nucleotidase (CD73, e5NT).

Objective And Methods: We investigated the localization of CD39 and CD73 proteins in human noncalcified and calcified aortic valves using immunohistochemistry together with analysis of NTPDases and e5NT activities in aortic valve homogenates by analysis of substrate into product conversion by high-performance liquid chromatography.

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The pathogenesis of pulmonary arterial hypertension remains undefined. Changes in the expression and effects mediated by a number of vasoactive factors have been implicated to play a role in the onset and progression of the disease. The source of many of these mediators, such as nitric oxide (NO), prostacyclin and endothelin-1 (ET-1), is the pulmonary endothelium.

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Medial calcification in the human aorta accumulates during aging and is known to be aggravated in several diseases. Atherosclerosis, another major cause of cardiovascular calcification, shares some common aggravators. However, the mechanisms of cardiovascular calcification remain poorly understood.

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Representative compounds from three classes of microporous solids, namely, metal-organic frameworks (MOFs), hybrid ultra-microporous materials (HUMs), and porous-organic polymers (POPs), were investigated for their nitric oxide gas uptake and release behavior. Low-pressure sorption studies indicated strong chemisorption of NO on the free amine groups decorating the MOF UiO-66-NH when compared to its non-amine-functionalized parent. The HUMs demonstrated reversible physisorption within the low-pressure regime, but interestingly in one case there was evidence for chemisorption following pressurization with NO at 10 bar.

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