Segmentation of transitional cell carcinoma nuclei by nonsupervised thresholding in different color spaces.

Objective: To develop a method for nonsupervised thresholding of transitional cell carcinoma nuclei of hematoxylin-eosin-stained histologic sections.

Study Design: For grayscale, RGB, HSL and L*a*b* thresholding we used an extension of a clustering method, based on a between-class/within-class criterion, applying optimal gray-level thresholding to distributions of R, G, B, or H and S or L* color domains. Algorithms were tested on 20 hematoxylin-eosin-stained sections of bladder carcinomas.

Post-exercise response of the systolic blood pressure in the diagnosis of coronary artery disease: comparison of two exercise methods.

We studied 81 angiographically documented coronary artery disease patients and 28 with normal coronary arteries, having paired exercise tests (the Bruce treadmill protocol and the jogging in place test) in order to investigate the value of the ratio of recovery systolic blood pressure to peak exercise systolic blood pressure (postexercise pressure ratio) compared to the classic ST depression. The postexercise pressure ratio was significantly higher in patients with coronary artery disease than in patients with normal coronary arteries for each of the 2 exercise tests (P less than 0.001--P less than 0.