Distal Colorectal Polyps and the Risk of Advanced Proximal Neoplasms It is uncertain how best to screen asymptomatic persons for colorectal cancer. This study determined the relative risk of advanced proximal neoplasms in persons 50 years of age or older who had distal polyps, as compared with those who did not have distal polyps. The authors found that although persons with distal polyps were at increased risk for advanced proximal neoplasia, about half of all cases would not have been detected if colonoscopy had been performed only in those with distal polyps.

Rapid Detection of Group B Streptococci This study compared the efficacy of a rapid polymerase-chain-reaction (PCR) assay, a conventional PCR assay and culture for the detection of group B streptococci in 112 women at the time of delivery. The sensitivity of both PCR assays was 97.0 percent, and both had a negative predictive value of 98.8 percent. The rapid PCR assay (process time, about 1 hour) identifies group B streptococci in time to allow the institution of antibiotic prophylaxis before delivery in many women.

Acetylcysteine to Prevent Contrast-Agent­Induced Reductions in Renal Function Radiographic contrast agents can reduce renal function. This study evaluated the use of acetylcysteine, which has antioxidant properties, to prevent deterioration of renal function in patients with renal insufficiency who must undergo scanning with contrast material. Among 41 patients given acetylcysteine before administration of the contrast agent, only 2 percent had an increase in the serum creatinine concentration, as compared with 21 percent of 42 patients given placebo.