Review Articles, News & Views, Perspectives, Hypotheses, Analyses and Review in 2005

Accumulation of visceral adipose tissue and the subsequent alteration in the secretion of adipocytokines could contribute to hypertension, impaired fibrinolysis and insulin resistance. This review discusses the role of visceral adipose tissue and the adipocytokines in nonalcoholic fatty liver disease.

The main vascular complications of inflammatory bowel disease are arterial and venous thrombosis. The mechanisms underlying these associations are not yet clear. This Review discusses the role of prothrombotic factors in the development of thromboembolism in patients with inflammatory bowel disease and considerations for therapy.

Coinfection with HCV and HIV is common and an increasingly important public health problem. Management of hepatitis C in HIV-infected patients is complicated by immune suppression, potential drug interactions and toxicities, and the relative paucity of health-care providers with expertise in the management of both diseases. Data now support the safety, tolerability and efficacy of hepatitis C treatment with peginterferon plus ribavirin in HIV-infected patients.

Direct infections of the gastrointestinal tract cause most cases of diarrhea, but diarrhea can also be caused by systemic infections or infections that affect other organ systems. The authors of this Review discuss clinically relevant infectious diseases that do not primarily affect the gastrointestinal tract but commonly cause diarrhea, and note that they should be included in the differential diagnosis and diagnostic approach to diarrhea.

Osteoporosis is an important problem for some patients with inflammatory bowel disease (IBD). Reports of low bone mineral density (BMD) in IBD patients buoyed widespread BMD testing for osteoporosis, but data on fracture incidence have now tempered these concerns. This Review considers the authors' approach to prevention and treatment of osteoporosis in IBD patients—a controversial subject, with advocates for more or less aggressive management.

The diagnosis of Budd–Chiari syndrome (BCS) is made difficult by its wide spectrum of presentations and the varying severity of liver damage seen in these patients. In addition, prognosis defined by the traditional BCS classification—as fulminant, acute or chronic—makes assessing therapeutic benefit more difficult. This Review highlights advances in the classification, prognosis and therapy of BCS.

Approximately 20-million episodes of travelers' diarrhea occur on an annual basis. Preventive measures and self-treatment are commonly used to combat the incapacitation that is associated with travelers' diarrhea and the possible development of chronic enteric complications. This Review focuses on current and future antibacterial drugs for the prevention and therapy of travelers' diarrhea, including the minimally absorbed antimicrobial drug rifaximin.

Nonalcoholic fatty liver disease is an increasingly recognized health problem. Its presentation ranges from simple steatosis to its inflammatory representation of nonalcoholic steatohepatitis. This Review considers various modalities that have been tried for nonalcoholic fatty liver disease, such as weight loss and/or exercise, thiazolidinediones, metformin, lipid-lowering agents and antioxidants, as well as considering treatments that are on the horizon.

At present, the only available treatment for celiac disease is a strict gluten-exclusion diet. Increasing numbers of patients are being diagnosed with celiac disease, making the need for alternative treatments even more urgent. Recent advances have improved our understanding of the molecular basis of celiac disease and new targets for rational therapy have been identified. This Review discusses concepts for new treatments and their current status.

Several mechanisms that control food intake have been described. As a result, effective appetite suppressants have been developed, and others are being evaluated. Monoamines, amino acids, and peptides all contribute to the control of feeding, and each of the pathways they are part of could contribute to the development of clinically useful drugs for the treatment of obesity.

Distinguishing patients with inflammatory bowel disease (IBD) from those with irritable bowel syndrome can be difficult, and a simple and reliable test that detects intestinal inflammation would be very useful in the clinic. This Review discusses the formation, measurement and intended clinical use of three novel markers of IBD—fecal calprotectin, fecal lactoferrin and luminal nitric oxide.

The choice of therapy for patients with irritable bowel syndrome (IBS) has been based on the predominant bowel symptom; however, it has proven difficult to identify any optimal single pharmacological therapeutic targets. This Review summarizes current and future therapeutic strategies for the treatment of IBS on the basis of putative pathophysiological models.

The total adipose tissue mass is now defined as a real endocrine organ, thanks to the discovery of adipocytokines. Adipocytokines are involved in many processes, including immune function and regulating energy homeostasis. This Review discusses the role of visceral adipose tissue and adipocytokines in intestinal and mesenteric diseases, with special focus on 'creeping fat' in Crohn's disease and mesenteric panniculitis.

In 2002, the United Network for Organ Sharing introduced the model for end-stage liver disease (MELD)/pediatric end-stage liver disease (PELD) organ allocation system. This Review discusses the history of donor liver allocation in the US, the development of the MELD/PELD allocation system, its success so far and its shortcomings, and the need to optimize the donor organ pool.

Two new types of imaging technology—laser-scanning confocal endoscopy series and contact endoscopy series—could reduce the number of biopsies that need to be taken by enabling anin vivo'virtual' histological diagnosis. Although it is currently not clear which technology should be adopted, microscopic evaluation of living tissue is now a reality.

The histologic spectrum of nonalcoholic fatty liver disease extends from isolated hepatic steatosis to steatohepatitis. Its pathogenesis is linked to insulin resistance and underlying metabolic syndrome. This Review discusses the physiologic basis for hepatic lipid homeostasis, its disturbance in insulin resistance and the genesis of nonalcoholic fatty liver and nonalcoholic steatohepatitis.

Over the past 20 years the applications of endoscopic ultrasound (EUS) have expanded, with real-time EUS-guided fine-needle aspiration and fine-needle injection now possible. This Review describes the current clinical status of EUS in gastrointestinal oncology, possible future and novel indications and therapeutic strategies.