an outbreak of toxic liver disease has been associated with exposure to dimethylformamide in the workplace. The diagnosis of toxic liver disease was established by the clinical histories, negative viral serologies, an enzyme pattern of ALT levels being greater than AST levels, epidemiologic data on coworkers, and liver biopsy specimens. The high prevalence of unsuspected liver enzyme abnormalities in these workers suggests that occupational liver disease may occur more frequently than is generally recognized.

With the technical assistance of Sue Marie Sanabria and Francesca MigliaccioTo evaluate the effect of balloon size and inflation pressure on acute and subsequent outcome following balloon angioplasty (BA), 70 New Zealand White rabbits with bilateral femoral atherosclerosis were assigned to four groups: group 1, oversized balloon, low inflation pressure (n=35 vessels; balloon size, 3.0 mm/inflation pressure, 5 atm); group 2, oversized balloon, high inflation pressure (n=36; 3.0 mm/10 atm); group 3, appropriate size, low inflation pressure (n = 17; 2.5 mm/5 atm); and group 4, appropriate size balloon, high inflation pressure (n = 19; 2.5 mm/10 atm). Angiograms were obtained before, 10 minutes after, and 28 days after BA and read by two blinded observers using electronic calipers. The in vivo ballon-to-vessel ratio was measured for each group. There were eight non-BA controls. Rabbits were sacrificed either immediately (n=34) or at 28 days after BA (n=36), with the femoral vessels pressure perfused for histologic and morphometric analysis. The 3, 9/17 [53%]; p

Redistribution thallium-201 imaging 2 to 4 h after exercise may be incomplete and therefore may be inadequate to fully assess myocardial variability. Late redistribution imaging 24 h after exercise has been proposed to overcome this limitation of thallium stress imaging. However, because of poor count density the image quality on these studies is often suboptimal. In the present study the diagnostic information on 24-h planar thallium redistribution images was compared with that on images obtained after a reinjection of thallium at rest. Eighty-four patients with a stress thallium-201 defect had delayed redistribution imaging after 2 to 4 h and 24 h later, and again after an injection of thallium at rest. Defect reversibility on 24-h redistribution images was compared quantitatively with that on images after injection of thallium at rest. The quality of thallium images at rest was consistently better than that of 24-h redistribution images. Poor quality studies occurred in 13% of 24-h redistribution images compared with 0.4% of the studies at rest. Significantly more defect reversibility was detected on images after the reinjection at rest. Of 41 patients who appeared to have a fixed defect at 2- to 4-h redistribution imaging, 11 (27%) had a reversible defect by 24-h redistribution imaging compared with 29 (71%) after thallium-201 reinjection. No clinical variables at the time of stress testing were predictive of late defect reversibility. It is concluded that in patients with fixed a thallium defect at 2 to 4 h after exercise, reimaging after a reinjection at rest provides better diagnostic information than does 24-h late redistribution imaging.

No abstract

Alterations in vessel wall reactivity (VR) at or adjacent to the dilation site after balloon angioplasty (BA) may vary according to the inflation protocol and the time after angioplasty and may influence outcome. In 64 atherosclerotic rabbit femoral arteries, we evaluated VR after BA with intravenous ergonovine (ERGO) (40 ,ug/min for 5 minutes) and intra-arterial nitroglycerin (NTG) (2,500 ,ug single bolus)