IL-21 shapes the B cell response in a context-dependent manner.

The T-cell-derived cytokine IL-21 is crucial for germinal center (GC) responses, but its precise role in B cell function has remained elusive. Using IL-21 receptor (Il21r) conditional knockout mice and ex vivo culture systems, we demonstrate that IL-21 has dual effects on B cells. While IL-21 induced apoptosis in a STAT3-dependent manner in naive B cells, it promoted the robust proliferation of pre-activated B cells, particularly IgG1 B cells.

The Melody Valve in Small Children Undergoing First Mitral Valve Replacement: Better Than Mechanical?

Background: In small children with left atrioventricular valve dysfunction, valve repair is preferred but some will require valve replacement. No prosthetic valve has growth potential, bioprostheses have poor durability, and mechanical prostheses have high rates of thromboembolic and hemorrhagic complications. We reviewed our experience with a modified bovine jugular vein valve designed for use in the right ventricular outflow tract (Melody valve, Medtronic) and compared this with contemporary mechanical valve replacement.

Patterns in California Ambulance Patient Offload Times by Local Emergency Medical Services Agency.

Importance: Ambulance offload delays are a timely and crucial issue with implications for patients, emergency medical services (EMS) agencies, hospitals, and communities. Published data on recent patterns in ambulance patient offload times (APOTs) are sparse.

Objective: To examine patterns in APOT by California local EMS agency and variation between and within local agencies.