Novel association of achalasia with hereditary sensory and motor neuropathy with sensorineural deafness.

Achalasia is a primary esophageal motility disorder. Unlike diffuse esophageal spasm, it has not previously been described in association with hereditary sensory and motor neuropathy (HSMN). An 18-year-old-male with HSMN with sensorineural deafness presented with a 2-day history of dysphagia to solids and liquids. Achalasia was diagnosed after extensive investigations, and his symptoms resolved with endoscopic and definitive surgical management. His monozygotic twin brother had also been diagnosed with HSMN and suffered from chronic dysphagia, which was also subsequently diagnosed with achalasia. This is the first case to illustrate an association between HSMN with sensorineural deafness and achalasia.

Review article: vitamin D and inflammatory bowel disease--established concepts and future directions.

BACKGROUND: Understanding of the role of vitamin D in health and disease has increased markedly in the past decade, with its involvement extending well beyond traditional roles in calcium and phosphate homeostasis and musculoskeletal health. This conceptual expansion has been underpinned by identification and exploration of components of this axis including vitamin D-binding protein, key enzymes and receptors in multiple cell types, and a greater recognition of nonclassical autocrine and paracrine effects. Its influence in IBD remains uncertain. AIM: To review the role of vitamin D in bone health, immune regulation and cancer prevention in IBD, and to outline practical issues and limitations of its use. METHODS: An extensive online literature review including PubMed and Medline. RESULTS: In patients with IBD, the vitamin D axis provides an important and often underutilised pathway to preserving bone health. Furthermore, an exciting body of clinical and basic science research demonstrates that these pathways may have an integral part to play in regulation of the immune response in IBD, through effects on the intestinal barrier, antigen presenting cells and adaptive T cells. The possibility of chemoprevention requires further study. The optimal target level of 25-hydroxy vitamin D in patients with IBD is currently uncertain, as is the best therapeutic modality. CONCLUSIONS: Study of vitamin D pathways may result in the development of relatively inexpensive therapeutic options to optimise patient outcomes. Further prospective clinical research is required to address efficacy and long-term safety.

Review article: the pathophysiological roles of the renin-angiotensin system in the gastrointestinal tract.

BACKGROUND: The renin-angiotensin system (RAS) is a homeostatic pathway widely known to regulate cardiovascular and renal physiology; however, little is known about its influence in gastrointestinal tissues. AIM: To elicit the anatomical distribution and physiological significance of the components of the RAS in the gastrointestinal tract. METHODS: An extensive online literature review including Pubmed and Medline. RESULTS: There is evidence for RAS involvement in gastrointestinal physiology and pathophysiology, with all the components required for autonomous regulation identified throughout the gastrointestinal tract. The RAS is implicated in the regulation of glucose, amino acid, fluid and electrolyte absorption and secretion, motility, inflammation, blood flow and possibly malignant disease within the gastrointestinal tract. Animal studies investigating the effects of RAS blockade in a range of conditions including inflammatory bowel disease, functional gut disorders, gastrointestinal malignancy and even intestinal ischaemia have been encouraging to date. Given the ready availability of drugs that modify the RAS and their excellent safety profile, an opportunity exists for investigation of their possible therapeutic role in a variety of human gastrointestinal diseases. CONCLUSIONS: The gastrointestinal renin-angiotensin system appears to be intricately involved in a number of physiological processes, and provides a possible target for novel investigative and therapeutic approaches.

Angiotensin converting enzyme 2 (ACE2) activity in fetal calf serum: implications for cell culture research.

Cell culture experiments often employ the use of culture media that contain fetal calf serum (FCS). The angiotensin peptides angiotensin II and angiotensin 1-7 have opposing effects with angiotensin converting enzyme 2 (ACE2) being the enzyme predominantly responsible for generating angiotensin 1-7 from angiotensin II. The effect of FCS on angiotensin peptides has not previously been described. We have shown that FCS has ACE2 enzyme activity capable of degrading angiotensin II and generating angiotensin 1-7. Researchers should be aware that FCS possesses ACE2 activity and that heat-treating FCS to 56 degrees C only partially inhibits this enzyme activity, whereas heat-treating to 70 degrees C completely abolishes ACE2 activity.

Hepatitis B virus reactivation following immunosuppressive therapy: guidelines for prevention and management.

It is well known that immunosuppressive drugs or cancer chemotherapy can stimulate replication of hepatitis B virus (HBV) and precipitate severe flares of HBV infection. The risk of this syndrome of 'reactivation hepatitis B' is highest in haematopoietic stem cell or solid organ transplant recipients and in those undergoing chemotherapy for haematological malignancies; however, it has been described following almost any form of immunosuppressive treatment. Fortunately, it can be largely prevented by prophylactic therapy with oral anti-HBV nucleoside/nucleotide analogues. Importantly, chronic HBV infection is usually asymptomatic, and most patients at risk are likely to be unaware that they carry the infection. Thus, the key to avoiding this potentially fatal complication of immunosuppressive treatment is to ensure that all patients at risk of chronic HBV infection are screened for the disease before commencing immunosuppressive treatment or chemotherapy.

Modern management of portal hypertension.

The development of portal hypertension plays a major role in the pathogenesis of many of the complications of chronic liver disease. In developed countries, most patients with portal hypertension have cirrhosis, and, in this condition, portal pressure is elevated as a result of both an increase in hepatic resistance to portal perfusion and increased mesenteric blood flow. Bleeding from oesophageal varices is a major cause of mortality in patients with significant portal hypertension. This review concentrates on the recognition, prevention and acute management of this life threatening complication of cirrhosis.