Computed tomographic studies of the painful abdomen

Abdominal CT scans were reviewed in a series of 53 patients who had abdominal pain without objective physical, radiographic, or laboratory abnormalities. Forty patients presented with abdominal pain alone, while the remaining patients had abdominal pain associated with nausea, vomiting, or mild weight loss. Abdominal CT scans in all patients were interpreted as normal. In all but one patient, the final diagnosis was an insignificant benign condition. One patient had a pancreatic carcinoma discovered at surgery one month after the CT scan was obtained. The patients were followed up for 6 to 12 months to confirm absence of significant disease. Our analysis suggests a very low yield from abdominal CT in patients with abdominal pain and no other objective findings.     

Optimal double-contrast visualization of the posteriorly directed duodenal bulb

The posteriorly directed duodenal bulb can be difficult to demonstrate because of the overlapping gastric antrum. A technique is described for displacing the antrum from the bulb while simultaneously distending the barium-coated duodenal bulb with air.     

Cell-cell recognition in yeast: isolation of intact alpha-agglutinin from Saccharomyces kluyveri.

The heat-labile sexual agglutinin from Saccharomyces kluyveri strain 17 (alpha-agglutinin) has been isolated in an apparently intact form from wild-type and mnn1 (glycosylation-defective) cells. The wild-type agglutinin is polydisperse, due to variable degrees of glycosylation, and migrates on native gels with an apparent mass of greater than 400 kDa, whereas under denaturing conditions it appears somewhat smaller. The mnn1 agglutinin is also heterogeneous but has a lower molecular mass due to the presence of shorter N- and O-linked polymannose chains. Both agglutinins are converted sequentially by proteolysis to active fragments of approximately equal to 150 and 60 kDa, but the rate of proteolysis of the more highly glycosylated wild-type agglutinin is much slower than that of the mnn1 agglutinin. The 60-kDa fragment was isolated by HPLC and found to contain 46% carbohydrate as mannose, all of which was linked to serine and threonine. Thus, the N-linked oligosaccharides are restricted to that part of the agglutinin molecule that presumably anchors the agglutinin in the cell wall.     

The effects of rate and forward masking on human adult and newborn auditory evoked brainstem response thresholds

Several investigators have reported that human newborn auditory brainstem evoked response (ABR) thresholds to clicks are about 10-20 dB higher than human adult thresholds to the same stimuli (Galambos amp; Hecox, 1978; Shulman-Galambos amp; Galambos, 1979; Lasky, Rupert, amp; Waller, 1987). The present study replicated these results, but, in addition, addressed developmental differences in ABR thresholds due to forward masking and changes in stimulus repetition rate. Eight human newborns and seven human adults served as subjects. Newborn ABR thresholds to a 100 μs click which followed a 82 db (A) SPL 50 ms broadband forward masker by 10 ms were significantly more elevated relative to their unmasked ABR thresholds than were those of the adults. Relatively loud sounds seem to have a greater effect on the newborn's ability to process subsequently presented soft sounds than they do on adult processing. In contrast, changes in repetition rate of 100μs clicks from 10/s to 50/s had no greater effect on newborn than adult ABR thresholds. At near threshold stimulus levels, rate effects on the ABR are not apparent in newborns nor adults.     

Adult Hirschprung disease: radiographic findings

Hirschprung disease is usually diagnosed in infancy. Occasionally patients reach adulthood without diagnosis or treatment. Four cases of adult Hirschprung disease are described. The principal radiographic findings are a markedly dilated, feces-filled colon above the zone of transition; a narrowed rectum; a cone- or funnel-shaped zone of transition; and a mosaic colonic pattern caused by collapsed redundant mucosa after colonic cleansing. In an adult, identification on a barium enema examination of an abrupt, smooth transition zone in the rectum with proximal colonic dilatation, in conjunction with an appropriate clinical history, should suggest the diagnosis of adult Hirschprung disease.