MR enterography in the evaluation of small bowel dilation.

Magnetic reasonance (MR) enterography enables high contrast resolution depiction of the location and cause of bowel obstruction through a combination of predictable luminal distension and multiplanar imaging capabilities. Furthermore, because the patient is not exposed to ionizing radiation, sequential "dynamic" MR imaging can be performed repeatedly over time further facilitating depiction of the site and/or the cause of obstruction. With increasing availability of MR imaging and standardization of the oral contrast medium regimens, it is likely that this technique will assume an ever-increasing role in the evaluation of small bowel dilation in the coming years. We illustrate the utility of MR enterography in the evaluation of small bowel dilation, whether it be mechanical, functional (e.g., ileus), or related to infiltrative mural disease.

Pediatric trauma center criteria: an outcomes analysis.

BACKGROUND/PURPOSE: Trauma centers (TC) are certified based on widely accepted criteria. These specific criteria rarely are scrutinized individually. The purpose of this study was to analyze the individual components of a pediatric trauma center for their effect on outcome. METHODS: Members of the National Pediatric Trauma Registry were queried about the following: (1) separate pediatric emergency department (ED), (2) pediatric intensive care unit (PICU), (3) pediatric intensivist as PICU director, (4) pediatric surgeon as TC director, (5) in-house attending surgeon, (6) in-house pediatric emergency physician, (7) 24-hour operating room, (8) 24-hour computed tomography (CT) scan. Outcomes analyzed included mortality, length of stay, time in ED, days in PICU, and disability. Victims were stratified based on age (<7 or > or = 7 years) and severity of injury (ISS < or = 16, 17-35, > or = 36). Results were compared using Student's t test and chi2 analysis. RESULTS: A total of 59 of 74 centers responded, 18 were dropped because of low enrollment (mean, 1.6 patients). Questions 3, 4, 6, and 7 were eliminated because of skewed data. An in-house surgeon reduced the amount of time a mildly injured patient (ISS < or = 16) spent in the ED (210 v434 minutes), as did the separate pediatric ED (333 v592 minutes) and pediatric emergency physicians (344 v 507 minutes) in younger patients (> or = 7 years). An in-house surgeon reduced the morality rate in older (> or = 7) severely injured (ISS > or = 36) patients (46.7% v 56.8%; P < .05 for all). No other differences were significant. CONCLUSIONS: In-house personnel improved efficiency for the less severely injured, and an in-house attending surgeon reduced mortality in the severely injured older patient. None of the other variables were found to have a significant impact on outcome.

Evidence that platelet and tumour heparanases are similar enzymes.

In order to enter tissues, blood-borne metastatic tumour cells and leucocytes need to extravasate through the vascular basal lamina (BL), a process which involves a battery of degradative enzymes. A key degradative enzyme is the endoglycosidase heparanase, which cleaves heparan sulphate (HS), an important structural component of the vascular BL. Previously, tumour-derived heparanase activity (which has been shown to be related to the metastatic potential of murine and human melanoma cell lines) was reported to cleave HS and be inhibited by heparin, as distinct from human platelet heparanase, which cleaved both substrates [Nakajima, Irimura and Nicolson (1988) J. Cell Biochem. 36, 157-167]. We recently reported the purification of human platelet heparanase and showed that the enzyme is a 50-kDa endoglucuronidase [Freeman and Parish (1998) Biochem. J. 330, 1341-1350]. We now report the purification and characterization of heparanase activity from highly metastatic rat 13762 MAT mammary adenocarcinoma and human HCT 116 colonic carcinoma cells and from rat liver using essentially the same procedure that was reported for purification of the human platelet enzyme. The rat 13762 MAT tumour enzyme, which has a native M(r) of 45 kDa when analysed by gel-filtration chromatography and by SDS/PAGE, was observed to be an endoglucuronidase that degraded heparin and HS to fragments of the same sizes as the human platelet enzyme does. N-deglycosylation of both the human platelet and rat 13762 MAT tumour enzymes gave, in each case, a 41-kDa band by SDS/PAGE analysis, demonstrating that the observed difference in M(r) between the platelet and tumour enzymes may have been due largely to differences in the relative amounts of N-glycosylation. Two peptides were isolated following Endoproteinase Lys-C digestion of both the human platelet and rat 13762 MAT tumour heparanases and were shown to be highly similar. Both the rat liver and human colonic carcinoma heparanases also degraded both heparin and HS to fragments of the same sizes as the human platelet enzyme does. Western-blot analysis of an SDS/PAGE gel using antibodies raised against human platelet heparanase demonstrated that human platelet, human tumour and rat tumour heparanases were immunochemically cross-reactive. In conclusion, because of the similarities in their sizes, substrate specificities, peptide sequences and immunoreactivities, we propose that heparanase activities present in human platelets, rat liver and in rat and human tumour cells are, in fact, mediated by a similar enzyme.