Gastric cancer is the second most common cause of cancer death in the world. Helicobacter pylori infection is now a well-accepted cause of this malignancy; in some parts of the world, up to eighty percent of all gastric cancers are at least in part caused by H. pylori infection. H. pylori infection typically starts in childhood as an inflammatory process in the stomach. The changes in the gastric microenvironment facilitate gastric cancer over time. Among infected individuals, genotype of H. pylori, coincident environmental exposures, and genetic factors of host seem to play roles in determining who will get gastric cancer and who will not. Unfortunately, it remains unknown whether treatment of H. pylori prevents gastric cancer. Thus, screening for H. pylori to prevent cancer is not yet widely recommended. Some consensus groups, however, have recommended screening for and treating H. pylori infection in individuals with family histories of gastric malignancy. In high-risk countries, screening programs for early gastric cancer itself may improve therapeutic outcome for this highly lethal disease.

Background: Cohort and case-crossover studies were conducted to evaluate whether new Helicobacter pylori infections are followed by increased diarrhea.

Methods: Participants were 6-month-old to 12-year-old shantytown residents living near Lima, Peru. Baseline data were collected from community households. Health interviews were completed daily, and sera, drawn every 4 months, were tested for H pylori immunoglobulin G. Diarrhea rates among newly H pylori-infected (seroconverting) children were compared with rates among persistently uninfected and infected children using cohort and case-crossover analyses.

Results: Sera were obtained from 345 children from January 1, 1995, through September 1, 1997. H pylori incidence was 12% per year (36 H pylori infections in 109 866 seronegative days). In adjusted cohort analyses, seroconverters had more diarrhea days (rate ratio: 2.0; 95% confidence interval: 1.6-2.4), episodes, and sick days in the year after infection than did uninfected children; and more diarrhea days and sick days than did persistently infected children. This effect was strongest in the first 2 months. Case-crossover analyses supported these findings.

Conclusion: Preventing H pylori infection may help reduce pediatric diarrheal disease.

Measuring the expression of most or all of the genes in a biological system raises major analytic challenges. A wealth of recent reports uses microarray expression data to examine diverse biological phenomena - from basic processes in model organisms to complex aspects of human disease. After an initial flurry of methods for clustering the data on the basis of similarity, the field has recognized some longer-term challenges. Firstly, there are efforts to understand the sources of noise and variation in microarray experiments in order to increase the biological signal. Secondly, there are efforts to combine expression data with other sources of information to improve the range and quality of conclusions that can be drawn. Finally, techniques are now emerging to reconstruct networks of genetic interactions in order to create integrated and systematic models of biological systems.

Thoroughly updated for its Second Edition, Hospital Medicine offers practical, evidence-based guidelines for the care of hospitalized patients. The only book geared directly and exclusively to inpatient management - and edited by the national leaders of the hospitalist field - Hospital Medicine includes indications for admission, guidelines for consultation, procedures for hospital discharge, diagnostic algorithms, and critical paths detailing effective, outcomes-oriented treatment plans for a range of diseases and disorders. New chapters in this edition focus on the hospitalist's increasing role in providing critical care, managing surgical patients with medical co-morbidities, ensuring patient safety and preventing adverse events, and directing hospital systems areas such as informatics, quality improvement, and practice management.

Prevention is an important role for all health care providers. Providers can help individuals stay healthy by preventing disease, and they can prevent complications of existing disease by helping patients live with their illnesses. To fulfill this role, however, providers need data on the impact of their services and the opportunity to compare these data over time or across communities. Local, State, and Federal policymakers also need these tools and data to identify potential access or quality-of-care problems related to prevention, to plan specific interventions, and to evaluate how well these interventions meet the goals of preventing illness and disability.

The Agency for Healthcare Research and Quality (AHRQ) Prevention Quality Indicators (PQIs) represent one such tool. Local, State, or national data collected using the PQIs can flag potential problems resulting from a breakdown of health care services by tracking hospitalizations for conditions that should be treatable on an outpatient basis, or that could be less severe if treated early and appropriately. The PQIs represent the current state of the art in measuring the outcomes of preventive and outpatient care through analysis of inpatient discharge data.

In response to a mail survey, 225 leading general internists provided their opinions of the relative importance to patients of thirty medical innovations. They also provided information about themselves and their practices. Their responses yielded a mean score and a variability score for each innovation. Mean scores were significantly higher for innovations in procedures than in medications and for innovations to treat cardiovascular disease than for those to treat other diseases. The rankings were similar across subgroups of respondents, but the evaluations of a few innovations were significantly related to physicians' age. The greatest variability in response was usually related to the physician's patient mix.

The specter of multidrug-resistant tuberculosis (MDR-TB) threatens the gains achieved by tuberculosis control through international recommendations currently accepted by 127 countries. The high cost of second-line drugs is a clear example of a market failure serving as a barrier to treatment of MDR-TB cases. Gupta et al. describe an approach based on policy development, consolidating and increasing demand, and increasing supply to decrease the cost of second-line drugs. As a result, prices decreased from 48-97% for a treatment regimen and competition was increased in monopoly markets. An independent scientific committee fosters access to the drugs under tightly monitored pilot projects to prevent the creation of resistance to second-line drugs. This strategy may be applicable to other infectious-disease treatment efforts.