Assessment of stable coronary artery disease by cardiovascular magnetic resonance imaging: Current and emerging techniques

Coronary artery disease(CAD) is a leading cause of death and disability worldwide. Cardiovascular magnetic resonance(CMR) is established in clinical practice guidelines with a growing evidence base supporting its use to aid the diagnosis and management of patients with suspected or established CAD. CMR is a multi-parametric imaging modality that yields high spatial resolution images that can be acquired in any plane for the assessment of global and regional cardiac function, myocardial perfusion and viability, tissue characterisation and coronary artery anatomy, all within a single study protocol and without exposure to ionising radiation. Advances in technology and acquisition techniques continue to progress the utility of CMR across a wide spectrum of cardiovascular disease, and the publication of large scale clinical trials continues to strengthen the role of CMR in daily cardiology practice. This article aims to review current practice and explore the future directions of multi-parametric CMR imaging in the investigation of stable CAD.

Diabetic cardiomyopathy: Pathophysiology, theories and evidence to date

The prevalence of type 2 diabetes(T2D)has increased worldwide and doubled over the last two decades.It features among the top 10 causes of mortality and morbidity in the world.Cardiovascular disease is the leading cause of complications in diabetes and within this,heart failure has been shown to be the leading cause of emergency admissions in the United Kingdom.There are many hypotheses and well-evidenced mechanisms by which diabetic cardiomyopathy as an entity develops.This review aims to give an overview of these mechanisms,with particular emphasis on metabolic inflexibility.T2D is associated with inefficient substrate utilisation,an inability to increase glucose metabolism and dependence on fatty acid oxidation within the diabetic heart resulting in mitochondrial uncoupling,glucotoxicity,lipotoxicity and initially subclinical cardiac dysfunction and finally in overt heart failure.The review also gives a concise update on developments within clinical imaging,specifically cardiac magnetic resonance studies to characterise and phenotype early cardiac dysfunction in T2D.A better understanding of the pathophysiology involved provides a platform for targeted therapy in diabetes to prevent the development of early heart failure with preserved ejection fraction.

Ligand-induced dimerization of syndecan-3 at the cell surface

Syndecan-3 (N-syndecan) is a transmembrane heparan sulfate proteoglycan abundantly expressed in developing brain. In addition to acting as a coreceptor, syndecan-3 acts as a signaling receptor upon binding of its ligand HB-GAM (heparin-binding growth-associated molecule;pleiotrophin), which activates the cortactin-src kinase signaling pathway. This leads to rapid neurite extension in neuronal cells, which makes syndecan-3 as an interesting transmembrane receptor in neuronal development and regeneration. However, little is known about the signaling mechanism of syndecan-3. Here we have analyzed formation of ligand-N-syndecan signaling complexes at the cell surface using fluorescence resonance energy transfer (FRET) and bioluminescence resonance energy transfer (BRET). We show that ligand binding leads to dimerization of syndecan-3 at the cell surface. The dimerized syndecan-3 colocalizes with actin in the filopodia of cells. Several amino acid residues (K383, G392 and G396) in the transmembrane domain are shown to be important for the ligand-induced dimerization, whereas the cytosolic domain is not required for the dimerization.