Interactive brain atlas with the Visible Human Project data: development methods and techniques.

A prototype of an interactive digital brain atlas was developed by using the Visible Human Project data set of the National Library of Medicine. This data set provides corresponding axial magnetic resonance images, computed tomographic images, and cryosections of the brain. The prototype was developed to demonstrate the techniques and methods that will be used throughout the development process of the atlas. The atlas has a graphical user interface, supports user interaction with various representations of the brain (i.e., two-dimensional and three-dimensional [3D]), and displays multiple images simultaneously. Motion sequences of the 3D brain were incorporated in the atlas to provide an important link between two-dimensional brain slices and volume-rendered 3D anatomic structures. Volume visualization tools were used to interactively render, rotate, and reslice the volumetric brain data. The brain was segmented with manual tracing, thresholding, and morphologic algorithms and then rendered with volume-rendering tools.

Leukotrienes in bile during the early and the late airway responses after allergen challenge of sensitized rats.

The Brown Norway rat produces high levels of IgE in response to active immunization and develops both early and late airway constrictor responses after subsequent allergen challenge. We have used this model of allergic asthma to investigate the temporal relationship between the in vivo synthesis of peptidoleukotrienes (peptido-LTs) and the late response. Brown Norway rats that had been sensitized by injection of ovalbumin 2 to 3 wk prior to the commencement of the experiment were subjected to bile duct cannulation and tracheal intubation. The rats were challenged 2 h later by intratracheal instillation of ovalbumin. Lung resistance was measured before and at frequent intervals after antigen challenge. Biliary peptido-LTs (LTC4, LTD4, LTE4, and N-acetyl-LTE4) were measured by a combination of high pressure liquid chromatography and radioimmunoassay in bile samples collected for a period of 1 h before instillation of ovalbumin, and between zero and 1 h, 1 and 4 h, 4 and 6 h, and 6 and 8 h, subsequently. All of the 10 rats subjected to antigen challenge developed early responses. Of these, six also developed late responses, whereas two died about 1 h after challenge. The levels of peptido-LTs excreted in bile between 4 and 8 h after antigen challenge (corresponding in time to the late responses) were about four times higher in the ovalbumin-instilled rats that developed late responses (n = 6) than in the ovalbumin-sensitized control rats that had been subjected to instillation of saline (n = 6; p < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)