Showing papers by "Iain M. Johnstone published in 1993"
TL;DR: The preliminary results suggest that diltiazem can prevent the usual reduction in the diameter of the coronary artery in cardiac-transplant recipients, but further follow-up will be required to determine whether dilt Diazem can decrease the long-term incidence of symptomatic coronary artery disease.
Abstract: Background Accelerated coronary artery disease is a major cause of late morbidity and mortality among heart-transplant recipients. Because calcium-channel blockers can suppress diet-induced atherosclerosis in laboratory animals, we assessed the efficacy of diltiazem in preventing coronary artery disease in transplanted hearts. Methods Consecutive eligible cardiac-transplant recipients were randomly assigned to receive diltiazem (n = 52) or no calcium-channel blocker (n = 54). Coronary angiograms obtained early after cardiac transplantation and annually thereafter were used for the visual assessment of the extent of coronary artery disease. The average diameters of identical coronary artery segments were measured on the angiograms obtained at base line and at the first and second follow-up examinations. Results In the 57 patients who had all three angiograms, the average coronary artery diameter (±SD) decreased in the group that received no calcium-channel blocker from 2.41 ±0.27 mm at base line to 2.19 ±0...
300 citations
Journal Article•
TL;DR: In this paper, the authors studied the asymptotic behavior of the minimax risk p (m T) and the construction of the minimum risk minimax estimators as m ~ oo, using the information normalized loss L i = 1.
Abstract: Suppose that the mean c of a vector of independent Poisson variates (Xl, ... , Xp) lies in a subset m T of RP, where T is a bounded domain and We study the asymptotic behavior of the minimax risk p (m T) and the construction of asymptotic minimax estiP mators as m ~ oo, using the information normalized loss L i= 1 With the use of the polydisc transform, a many-to-one mapping from 1R2p to we show that where X (Q) is the principal eigenvalue for the Laplace operator on the pre-image Q of T under this transform. The proofs exploit the connection between p-dimensional Poisson estimation in T and 2 p-dimensional Gaussian estimation inQ.
4 citations