Regulation of synthesis and roles of hyaluronan in peritoneal dialysis.

Hyaluronan (HA) is a ubiquitous extracellular matrix glycosaminoglycan composed of repeated disaccharide units of alternating D-glucuronic acid and D-N-acetylglucosamine residues linked via alternating ß-1,4 and ß-1,3 glycosidic bonds. HA is synthesized in humans by HA synthase (HAS) enzymes 1, 2, and 3, which are encoded by the corresponding HAS genes. Previous in vitro studies have shown characteristic changes in HAS expression and increased HA synthesis in response to wounding and proinflammatory cytokines in human peritoneal mesothelial cells. In addition, in vivo models and human peritoneal biopsy samples have provided evidence of changes in HA metabolism in the fibrosis that at present accompanies peritoneal dialysis treatment. This review discusses these published observations and how they might contribute to improvement in peritoneal dialysis.

Use of transthoracic echocardiography in the evaluation of chest pain: illustrative cases and review of recent guidelines.

Chest pain (CP) is a very common presentation with a wide range of differential diagnoses, including life-threatening conditions, which need to be considered, diagnosed and treated urgently. Cardiac CP accounts for less than one-third of causes. Echocardiography is a valuable non-invasive tool that can help in diagnosing and treating patients presenting with CP. National Institute for Health and Care Excellence (NICE), European Society of Cardiology (ESC) and American Heart Association (AHA) guidelines state that echocardiography can help in the diagnosis of acute coronary syndromes and also in ruling out other serious conditions. We present three cases where transthoracic echocardiography (TTE) was essential in assessing patients, making the correct diagnosis and offering the right treatment. This article emphasises the importance of using TTE in assessing patients with CP and hopes to promote its consideration in day-to-day practice.