Enteric intussusception presenting as a rapidly enlarging mass.

Enteric intussusception is unusual in adults and frequently presents in a confusing manner. A case of jejunojejunal intussusception is presented in which a 15-cm abdominal mass developed in 24 h. The plain film, barium, and ultrasound findings in enteric intussusception are stressed.

Sonographic features of hepatocellular disease in neonates and infants.

The sonograms of 12 neonates and infants with documented nonneoplastic parenchymal liver diseases, including cytomegalovirus infection, biliary atresia, alpha 1-antitrypsin deficiency, nesidioblastosis, Alagille association, microabscesses, and idiopathic neonatal jaundice, were analyzed by various sonographic criteria. Nine (75%) of the hepatic sonograms were abnormal; however, most showed only one sonographic abnormality. Although it was not possible to distinguish one condition from another sonographically, focal areas of heterogeneity simulating mass lesions and accentuated periportal brightness were the most notable abnormal features. The prime indication for hepatic sonography in this age group continues to be the differentiation of obstructive from nonobstructive jaundice. Nonetheless, when obstruction has been excluded, sonography may demonstrate the presence of hepatic parenchymal disease and provide a noninvasive means for following its course over time.

The relative roles of input and output mechanisms in directed forgetting.

When Ss are presented a first set of items (Set A) followed by a second set (Set B), a postinput cue to recall only Set B results in better recall of Set B than does a cue to recall Set B then Set A; to a lesser extent, the same result holds for Set A. Such "Only" effects (Epstein, 1970) have typically been attributed to selective search processes at the time of recall. In the free-recall experiment reported here, cues to remember all, only two, or none of the items in each of eight successive four-word blocks were presented either before or after a 3-sec rehearsal period. Even though the search set at output was constant (16 to-be-recalled words), there was an Only effect for blocks followed by selective (postcue) rehearsal, whereas nonselective (precue) rehearsal produced no such effect. More striking than that result was the incredible ability of Ss, whatever the condition, to differentiate to-be-remembered and to-be-forgotten items. Set differentiation during input appears much more important as a mechanism of directed forgetting than either selective search or selective rehearsal.