The mechanisms underlying the chronic intestinal inflammation that is a hallmark of inflammatory bowel diseases (IBD) are complex. Components of the pathological response include the adaptive and innate immune systems, as well as the intestinal epithelium and endothelium. Advances in the understanding of the roles of each of these components have resulted in the development of multiple biological agents that all represent an alternative to the use of current therapies in patients with refractory Crohn's disease or ulcerative colitis. This study systematically reviews the mechanisms of action, efficacy and safety of new and emerging therapies that are currently in clinical trials and discusses future directions in the treatment of IBD.

Alcoholic liver disease (ALD) accounts for the majority of chronic liver disease in Western countries. The spectrum of ALD includes steatosis with or without fibrosis in virtually all individuals with an alcohol consumption of >80 g/day, alcoholic steatohepatitis of variable severity in 10-35% and liver cirrhosis in approximately 15% of patients. Once cirrhosis is established, there is an annual risk for hepatocellular carcinoma of 1-2%. Environmental factors such as drinking patterns, coexisting liver disease, obesity, diet composition and comedication may modify the natural course of ALD. Twin studies have revealed a substantial contribution of genetic factors to the evolution of ALD, as demonstrated by a threefold higher disease concordance between monozygotic twins and dizygotic twins. With genotyping becoming widely available, a large number of genetic case-control studies evaluating candidate gene variants coding for proteins involved in the degradation of alcohol, mediating antioxidant defence, the evolution and counteraction of necroinflammation and formation and degradation of extracellular matrix have been published with largely unconfirmed, impeached or even disproved associations. Recently, whole genome analyses of large numbers of genetic variants in several chronic liver diseases including gallstone disease, primary sclerosing cholangitis and non-alcoholic fatty liver disease (NAFLD) have identified novel yet unconsidered candidate genes. Regarding the latter, a sequence variation within the gene coding for patatin-like phospholipase encoding 3 (PNPLA3, rs738409) was found to modulate steatosis, necroinflammation and fibrosis in NAFLD. Subsequently, the same variant was repeatedly confirmed as the first robust genetic risk factor for progressive ALD.

The number of patients with chronic gastrointestinal (GI) symptoms after cancer therapies which have a moderate or severe impact on quality of life is similar to the number diagnosed with inflammatory bowel disease annually. However, in contrast to patients with inflammatory bowel disease, most of these patients are not referred for gastroenterological assessment. Clinicians who do see these patients are often unaware of the benefits of targeted investigation (which differ from those required to exclude recurrent cancer), the range of available treatments and how the pathological processes underlying side effects of cancer treatment differ from those in benign GI disorders. This paper aims to help clinicians become aware of the problem and suggests ways in which the panoply of syndromes can be managed.

These guidelines update previous guidance published in 2005. They have been revised by a group who are members of the UK and Ireland Neuroendocrine Tumour Society with endorsement from the clinical committees of the British Society of Gastroenterology, the Society for Endocrinology, the Association of Surgeons of Great Britain and Ireland (and its Surgical Specialty Associations), the British Society of Gastrointestinal and Abdominal Radiology and others. The authorship represents leaders of the various groups in the UK and Ireland Neuroendocrine Tumour Society, but a large amount of work has been carried out by other specialists, many of whom attended a guidelines conference in May 2009. We have attempted to represent this work in the acknowledgements section. Over the past few years, there have been advances in the management of neuroendocrine tumours, which have included clearer characterisation, more specific and therapeutically relevant diagnosis, and improved treatments. However, there remain few randomised trials in the field and the disease is uncommon, hence all evidence must be considered weak in comparison with other more common cancers.

Iron deficiency is a common condition increasingly diagnosed and treated by gastroenterologists. The most common presentation of iron deficiency is anaemia; however, it is a systemic disorder affecting multiple aspects of health in various organs. Iron is an essential element, with iron-containing proteins exerting a variety of vital functions, including oxygen transport, cellular respiration, intermediary metabolism, regulation of transcription and DNA repair. Major pathways of iron utilisation and production of iron-containing proteins include iron sulphur cluster biosynthesis, haem synthesis and storage within ferritin. The main site of iron absorption is the small intestine, but most iron is recycled by the monocyte-macrophage system via phagocytosis of senescent erythrocytes. Hepcidin, the key iron-regulating peptide binds to the iron exporter ferroportin and leads to its degradation, thereby inhibiting intestinal iron absorption and cellular export. Hepcidin levels are regulated on a transcriptional level by various stimuli, including transferrin saturation, erythropoietic activity, hypoxia and inflammation. Iron deficiency evokes adaptive responses resulting in alteration of cellular metabolism, changes in gene expression, activation of signalling pathways, cell cycle regulation, differentiation and cell death. Such responses are mediated by a number of iron-sensitive signalling pathways, including the IRE/IRP system, HIF and haem signalling. This review provides a molecular perspective for the clinician and highlights important biological aspects of iron deficiency.

Transcription factors are proteins that regulate gene expression by modulating the synthesis of messenger RNA. Since this process is often one dominant control point in the production of many proteins, transcription factors represent the key regulators of numerous cellular functions, including proliferation, differentiation and apoptosis. Pancreatic cancer progression is characterised by activation of inflammatory signalling pathways converging on a limited set of transcription factors that fine-tune gene expression patterns contributing to the growth and maintenance of these tumours. Thus strategies targeting these transcriptional networks activated in pancreatic cancer cells could block the effects of upstream inflammatory responses participating in pancreatic tumorigenesis. The authors review this field of research and summarise current strategies for targeting oncogenic transcription factors and their activating signalling networks in the treatment of pancreatic cancer.

Crohn's disease is a chronic inflammatory disorder that follows a progressive and destructive course. Ultimately, uncontrolled inflammation leads to bowel damage from disease-related complications such as strictures, fistulas and abscesses and surgical resection. Conventional 'step-care', whereby corticosteroids and immunosuppressives are prescribed sequentially, is an incremental approach to treatment that does not prevent disease progression and conveys an important risk of adverse events from repeated courses of corticosteroids. Although the immunosuppressives azathioprine, 6-mercaptopurine and methotrexate are corticosteroid-sparing, they are not highly effective for inducing mucosal healing or preventing disease progression. Tumour necrosis factor antagonists induce and maintain mucosal healing and reduce surgery and hospitalisation rates. This holds out the possibility that long-term use of these agents may prevent bowel damage. Combination therapy with immunosuppressives and tumour necrosis factor antagonists is likely the best strategy for achieving optimal outcomes in patients at high risk of disease progression. However, accurate prognostic markers must be identified to guide patient selection. Long-term prospective studies with robust outcomes are still needed to establish definitively the efficacy and safety of early combination therapy to prevent bowel damage, loss of gastrointestinal tract function and permanent disability.

The risk of oesophageal adenocarcinoma (OAC) in non-dysplastic Barrett's oesophagus (BO) may have been overestimated. The objective was to estimate the incidence of OAC in patients with BO without dysplasia.

Proteases play a decisive role in health and disease. They fulfil diverse functions and have been associated with the pathology of gastrointestinal disorders such as inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). The current knowledge focuses on host-derived proteases including matrix metalloproteinases, various serine proteases and cathepsins. The possible contribution of bacterial proteases has been largely ignored in the pathogenesis of IBD and IBS, although there is increasing evidence, especially demonstrated for proteases from pathogenic bacteria. The underlying mechanisms extend to proteases from commensal bacteria which may be relevant for disease susceptibility. The intestinal microbiota and its proteolytic capacity exhibit the potential to contribute to the pathogenesis of IBD and IBS. This review highlights the relevance of host- and bacteria-derived proteases and their signalling mechanisms.

Coeliac disease is a gut disease driven by an abnormal immune response towards dietary gluten in genetically susceptible individuals. Whether and, if so, how abnormal transport of gluten across the gut epithelium may participate in the pathogenesis of coeliac disease remains debatable. This paper summarises the interactions of gluten-derived peptides with the intestinal epithelium and discusses the mechanisms that control their transport across the epithelium. It shows how recent data point to a key role for the transcellular pathway and highlights the 'Trojan horse' role of secretory IgA which can hijack the transferrin receptor and allow the rapid translocation of intact gluten peptides into the mucosa. These recent findings might be useful for the design of new treatments.

Over recent years, it has become increasingly accepted that virus-specific CD4+ and CD8+ T cell responses play a major role in outcome and pathogenesis of hepatitis C virus (HCV) infection. Indeed, while the emergence of strong and multispecific T cell responses may correlate with spontaneous viral clearance, the virus has developed several mechanisms to avoid T cell control in the majority of acutely HCV-infected patients that subsequently develop persistent HCV infection. In this review, we will discuss the current knowledge about the role of cellular immune responses in HCV infection. Specifically, we will emphasise recent new insights into the effector functions of T cells, possible mechanisms of their failure and the host-virus interactions occurring at the site of the disease, the liver.

Pancreatic ductal adenocarcinoma (PDAC) remains a devastating disease despite tremendous scientific efforts. Numerous trials have failed to improve the outcome on this deadliest of all major cancers. Potential causes include a still insufficient understanding of key features of this cancer and imperfect preclinical models for identification of active agents and mechanisms of therapeutic responses and resistance. Modern genetically engineered mouse models of PDAC faithfully recapitulate the genetic and biological evolution of human PDAC, thereby providing a potentially powerful tool for addressing tumour biological issues as well as strategies for early detection and assessment of responses to therapeutic interventions. Here, the authors will discuss opportunities and challenges in the application of genetically engineered mouse models for translational approaches in pancreatic cancer and provide a non-exhaustive list of examples with already existing or future clinical relevance.

Current advances in our understanding of stem and precursor cell biology and in the protocols of stem cell isolation and transplantation have opened up the possibility of transplanting neural stem cells for the treatment of gastrointestinal motility disorders. This review summarises the current status of research in this field, identifies the major gaps in our knowledge and discusses the potential opportunities and hurdles for clinical application.

Functional gastrointestinal disorders (FGIDs) are characterised by visceral pain or discomfort with an unknown cause. There is increasing evidence for abnormal processing of sensory input in FGIDs. Modulation of sensory input occurs at all levels of the nervous system, with a dynamic balance between facilitation and inhibition and close integration with the body's wider homoeostatic control. Cognitive, emotional, autonomic and spinal reflex pathways effectively orchestrate supraspinal and spinal pain modulation, as demonstrated in neurophysiological and brain imaging studies. Endogenous pain modulation has been studied in visceral pain conditions and abnormal regulation has been shown in irritable bowel syndrome (IBS) and functional dyspepsia, as well as other chronic pain syndromes. A majority of patients with IBS have diminished pain inhibition or even pain facilitation compared with healthy controls. Brain imaging during specific activation of endogenous pain modulation demonstrates a fairly consistent functional hub of mainly frontal, limbic and brainstem modulatory regions in healthy humans. Patients with IBS have a different pattern of activation and a correlation between the imaging and sensory changes. Because the modulatory balance of inhibition and facilitation appears to be distributed within the same functional network, future imaging studies of modulation mechanisms should include conditions allowing quantification of inhibitory and facilitatory components. An altered modulatory balance may well be a unifying pathophysiological mechanism in FGID as it can be driven by both top-down (ie, CNS pathology) and bottom-up (ie, peripheral immune activation) influences, but further validation in diverse FGID groups over time is required. Therapeutic manipulation of the modulatory system is possible by both pharmacological and non-pharmacological means.

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease which, if untreated, often leads to cirrhosis, liver failure and death. Major advances were made in its management based on controlled trials performed in England and the USA in the 1970s and 1980s. Unfortunately, in recent decades there has been a dearth of controlled clinical trials and, thus, many questions regarding the optimal management of this disease remain unanswered. Many promising newer immunosuppressive therapies await formal comparison with standard therapies and also many important details in relation to the application of standard therapies remain unclear. These guidelines describe the optimal management strategies in adults based on available published evidence, including the American Association for the Study of Liver Diseases practice guidelines for the diagnosis and treatment of AIH published in 2002 and recently updated.

Pancreatic ductal adenocarcinoma (PDAC) has long been considered to arise from pancreatic ducts on the basis of its morphology, the occurrence of dysplasia in putative preneoplastic ductal lesions, and the absence of acinar dysplasia in the pancreas of patients with PDAC. However, evidence gathered through both in vitro studies and--more importantly--genetic mouse models of PDAC shows that ductal-type tumours can arise from acinar cells. These findings raise new important questions related to PDAC pathophysiology and call for in-depth studies of acinar cell differentiation in order to better understand PDAC biology. The authors review these issues and discuss how the novel findings should impact on future work aiming at early diagnosis and improved outcome of patients with PDAC.

The impact of inflammatory bowel disease (IBD) on disability remains poorly understood. The World Health Organization's integrative model of human functioning and disability in the International Classification of Functioning, Disability and Health (ICF) makes disability assessment possible. The ICF is a hierarchical coding system with four levels of details that includes over 1400 categories. The aim of this study was to develop the first disability index for IBD by selecting most relevant ICF categories that are affected by IBD.