Effect of magnitude of airway responsiveness and therapy with inhaled corticosteroid on histamine tachyphylaxis in asthma.

Histamine challenge testing is used to measure airway responsiveness in asthma. Histamine tachyphylaxis has been demonstrated after repeated challenges in mild asthmatics not using inhaled corticosteroid. Other studies, using subjects with variable severity of asthma, have not demonstrated histamine tachyphylaxis.

The ultrasound macroscope: initial studies of breast tissue.

A system called the ultrasound macroscope has been developed to measure the ultrasonic properties of tissues. Based on the concept of the scanning acoustic microscope, it is capable of generating quantitative images of ultrasound velocity, attenuation and backscatter for macroscopic slices of tissue. By maintaining high resolution (approximately 120 microns at 13 MHz) the morphology of complex tissues is well delineated.