CT findings of mesenteric injury after blunt trauma: implications for surgical intervention.

OBJECTIVE: The purposes of this study were to determine the spectrum of CT findings of mesenteric injury, to compare CT findings of mesenteric injury with surgical observations, and to assess the potential of CT to predict which patients with mesenteric injury require laparotomy. MATERIALS AND METHODS: Blunt trauma patients admitted to our facility during a 5-year 4-month period with a CT or surgical diagnosis of mesenteric injury were identified from a radiology database and trauma registry. Patients with CT findings of full-thickness bowel injury associated with mesenteric injury or diagnostic peritoneal lavage performed before CT were excluded. CT scans of all patients were retrospectively reviewed both with and without knowledge of surgical results. Medical records of all study patients were reviewed to ascertain admission physical findings and surgical results. RESULTS: Twenty-seven of 29 patients meeting the study criteria underwent laparotomy, and two others were managed conservatively. Among the 27 patients who had surgery. 24 (89%) had CT findings of mesenteric injury confirmed. Surgical findings showed CT scans to be falsely negative in two other patients and falsely positive in one other patient. No major discrepancies were found between retrospective CT review done with and without knowledge of the surgical findings. Two CT findings unique to patients whose injuries, in the judgment of the surgical team, required surgical repair were active extravasation of IV contrast material and bowel wall thickening associated with mesenteric findings. Physical findings did not correlate well with the type and clinical significance of the mesenteric injury. CONCLUSION: The CT finding of mesenteric bleeding or bowel wall thickening associated with mesenteric hematoma or infiltration in the blunt trauma patient indicates a high likelihood of a mesenteric or bowel injury requiring surgery. The finding of focal mesenteric hematoma or infiltration without adjacent bowel wall thickening is nonspecific and can occur both in mesenteric or bowel lesions that require surgery and those that do not.

Protease activity associated with loss of adhesiveness in mouse teratocarcinoma.

We have observed the spontaneous conversion of an embryoid body (multicellular) form of 129/J mouse ascites teratocarcinoma to a single cell form. Concomitant with the conversion, a rapid increase in growth rate and ascites fluid accumulation have been observed. This report presents data on protease activity in the ascites fluid after the conversion and evidence that the protease causes decreased tumor cell adhesiveness. Ascites protease has a pH optimum of 2.0-3.0 and is inhibited by both DAN (diazoacetyl-DL-norleucine methyl ester) and Pepstatin A. Using denatured bovine hemoglobin as a substrate, the low pH optimum and inhibition by DAN and Pepstatin A allow tentative identification of the enzyme as the carboxypeptidase Cathepsin D. Approx. 0.036 X 10(-2) micrograms of Cathepsin D per mg of protein was found in the ascites fluid of the single cell form of the mouse teratocarcinoma. We show that Pepstatin A-derivatized agarose beads bind the single ascites cells, causing them to display increased cell-cell adhesion, a phenomenon not observed with control beads. The results suggest that ascites protease may play a role in transformation of a slow growing, clustered tumor into a rapidly growing, non-adhesive, single cell form. We found that an embryoid-like tissue culture line of mouse teratocarcinoma, that we established, disaggregated into single cells, upon addition of ascites fluid from the single cell tumor, to the culture medium. Pepstatin A prevented disaggregation of the cell clusters. These results further support the contention that specific ascites protease plays a role in the transformation of a clustered tumor into a single cell form.