This study found that plasma cells from the bone marrow of patients with myeloma and osteolytic lesions expressed high levels of the DKK1 gene and produced the DKK1 protein, whereas plasma cells from patients without bone lesions did not overexpress the gene or produce the protein.

DKK1 inhibits Wnt signaling, which is essential for the growth and development of osteoblasts. The DKK1 produced by myeloma cells seems to tip the balance between osteoblasts and osteoclasts in favor of bone resorption. The study sheds new light on how osteolytic lesions form in multiple myeloma.

This investigation of the treatment of multiple myeloma compared one cycle of high-dose chemotherapy plus a single autologous stem-cell transplantation with two cycles of high-dose chemotherapy, each followed by stem-cell transplantation. The double-transplantation regimen had a substantial survival benefit.

This well-conducted, large trial indicates that double transplantation can benefit patients with myeloma who are younger than 60 years, especially those with an unsatisfactory response after a single transplantation.

Lack of glycogen phosphorylase in patients with McArdle's disease blocks muscle glycogenolysis, resulting in low exercise tolerance and often in muscle injury, particularly in the first minutes of exercise. As the investigators in this single-blind, randomized, placebo-controlled trial hypothesized, ingesting sucrose before exercise increased the availability of glucose and therefore improved exercise tolerance in patients with the disease.

The ingestion of oral sucrose seems to improve exercise capacity and a sense of well-being in patients with McArdle's disease and may provide protection against exercise-induced rhabdomyolysis.

This prospective cohort study compared the performance of two clinical decision rules for evaluating cervical-spine injury. As compared with the NEXUS Low-Risk Criteria (which are widely recommended), the Canadian C-Spine Rule was more sensitive and more specific for clinically important injury and would have resulted in fewer orders for cervical-spine radiographs.

These data have important implications for the evaluation of possible cervical-spine injury in the emergency department.

The transportation of illicit drugs by concealment within the body is now a common practice, and it has implications for clinical care. Body packers may ingest dozens of packets containing life-threatening doses of heroin, cocaine, or amphetamines. These smugglers may then present to physicians for evaluation while in legal custody or because of drug-induced toxic effects or obstruction or perforation of the gastrointestinal tract. This review provides guidance for the recognition and management of this clinical problem, which often also poses ethical and legal challenges for the clinician.

In acquired pulmonary alveolar proteinosis, lipids and proteins accumulate within the alveoli because alveolar macrophages cannot catabolize surfactants. Surprisingly, alveolar macrophages require granulocyte–macrophage colony-stimulating factor (GM-CSF) to perform this function. Autoantibodies against GM-CSF may cause pulmonary alveolar proteinosis.

Studies of this rare disease have revealed an important function of alveolar macrophages and the ways in which the lung protects itself from infection. This review makes a strong argument that pulmonary alveolar proteinosis is an autoimmune disease.

The discovery of a molecule that interferes with a component of the insulin-signaling pathway provides a target for drug development.