Flow Decay: A Novel Spirometric Index to Quantify Dynamic Airway Resistance.

Background: Dynamic airway resistance from obstructive disease causes a concavity in the mid-expiratory portion of the spirometric flow-volume loop. We developed a simple model to measure the exponential decay in air flow during forced exhalation to quantify the extent of dynamic airway obstruction and facilitate the detection of obstructive airway diseases clinically.

Methods: We calculated flow decay as the slope of volume versus ln(1/flow) in mid-exhalation.

Need for injury-prevention education in medical school curriculum.

Injury is the leading cause of death and disability among the U.S. population aged 1 to 44 years.

BMPs regulate multiple aspects of growth-plate chondrogenesis through opposing actions on FGF pathways.

Bone morphogenetic protein (BMP) signaling pathways are essential regulators of chondrogenesis. However, the roles of these pathways in vivo are not well understood. Limb-culture studies have provided a number of essential insights, including the demonstration that BMP pathways are required for chondrocyte proliferation and differentiation.

Bmpr1a and Bmpr1b have overlapping functions and are essential for chondrogenesis in vivo.

Previous studies have demonstrated the ability of bone morphogenetic proteins (BMPs) to promote chondrogenic differentiation in vitro. However, the in vivo role of BMP signaling during chondrogenesis has been unclear. We report here that BMP signaling is essential for multiple aspects of early chondrogenesis.