Dyspnea is a common symptom of cardiac and noncardiac disorders, but its prognostic significance has not been extensively evaluated. In a study of nearly 18,000 patients undergoing stress and resting myocardial-perfusion imaging, those presenting with dyspnea had more than twice the risk of death from cardiac causes or from any cause of those presenting with typical angina.

With the use of molecular methods, investigators characterized the bacteria in vaginal fluid from 27 women with bacterial vaginosis and from 46 women without the condition. In the women with bacterial vaginosis there were more species and far greater bacterial diversity, including several new organisms not previously described. Three bacteria in the Clostridiales order were highly specific for the presence of bacterial vaginosis.

Patients with active Crohn's disease who were randomly assigned to receive natalizumab did not have a significantly higher rate of initial response than those assigned to placebo (56 percent vs. 49 percent, P=0.05). Among patients with a response, those randomly assigned to continue natalizumab were more likely to have a sustained response than those assigned to placebo (61 percent vs. 28 percent, P<0.001). One patient treated with natalizumab died from progressive multifocal leukoencephalopathy associated with the JC virus, a human polyomavirus.

This report describes two neurologically devastated infants who died as newborns from congenital glutamine synthetase deficiency and profoundly low levels of glutamine in bodily fluids and the circulation. Homozygous mutations in glutamine synthetase, which plays a major role in ammonia detoxification, interorgan nitrogen flux, acid–base homeostasis, and cell signaling, were detected.

A Baltimore college student has rhinorrhea, sneezing, nasal congestion, and itchy, watery eyes in the spring. He reports having had similar symptoms the previous spring. Over-the-counter allergy pills failed to help his symptoms and caused dry mouth and somnolence. He wants relief and assurance that he won't be ill, have dry mouth, or feel drowsy during final exams. On examination, his conjunctivae are injected, and his nasal mucous membranes are pale, wet, and boggy. What should the physician recommend?

There are an estimated 13 million injection-drug users worldwide, and infections are among the most serious complications of drug use. This article reviews the common problems associated with drug use, including skin and soft-tissue infections, septic arthritis, osteomyelitis, and endovascular infections. The authors describe the most common organisms and provide guidance on both treatment and prevention.

A 21-year-old male college student presented to the student health center with two days of extreme fatigue. Over the course of the previous two months, frequent headaches, difficulty concentrating, and decreased exercise tolerance had developed. He recently had had several days of nasal congestion and sore throat, but these symptoms had improved. A cursory physical examination was normal, but pulse oximetry revealed an oxygen saturation of only 55 percent.