Gastrinoma

Although there are multiple etiologies of clinical hypergastrinemia, the most important cause is gastrinoma [Zollinger-Ellison (ZE) syndrome]. The most significant advance in the management of patients with the ZE syndrome has been the development of the ability to establish firmly the correct preoperative diagnosis by radioimmunoassay. We believe that all patients who have the ZE syndrome should undergo operation for two reasons: to identify and resect all tumor and because in patients in whom no tumor is found or in whom all tumor cannot be resected, the most reliable relief of hypersecretory symptoms for the life of the patient can be achieved by total gastrectomy.     

Fibroma of tendon sheath

Fibroma of the tendon sheath is a distinct clinicopathologic entity rarely occurring on the foot. It is a benign tumor derived from the fibroblast that clinically appears as a slow-growing painless mass. Complete surgical excision is curative. Recurrence occurs in 24% of the cases, usually due to inadequate excision. This report describes a 36-year-old man with such a tumor of the foot.     

The role of neurotensin in human gallbladder motility.

Gallbladder contraction in response to a fatty meal is thought to be caused by release of cholecystokinin (CCK). We have previously demonstrated a close correlation between circulating concentrations of CCK and contraction of the gallbladder in normal humans and in gallstone patients. Recent studies in animals, however, have shown that other potentially cholecystokinetic hormonal agents are released by a fatty meal, which suggests that other hormones may be involved in postprandial gallbladder contraction. Neurotensin, a 13-amino acid peptide, is released by fat; we have shown it to cause gallbladder contraction in dogs. In the present study, we measured release of neurotensin in seven normal adult volunteers. We determined the effects of infused neurotensin (4 pmol/kg-min) on gallbladder contractility, measured by ultrasonography in 10 adult volunteers, and we evaluated release of neurotensin in eight patients with gallstones. After ingestion of fat, we found significant release of neurotensin in normal volunteers from a mean basal concentration of 15.9 +/- 3.5 pg/ml to a maximum of 34.7 +/- 0.2 pg/ml. In the gallstone patients after fat ingestion, neurotensin rose from a basal of 16.8 +/- 3.1 pg/ml to a maximum of 53.4 +/- 28.1 pg/ml, which was a significantly greater release than in controls. Intravenous infusion of neurotensin produced dilatation of the gallbladder (from a mean basal volume of 13.7 +/- 2.3 cc to 20.0 +/- 1.8 cc). Neurotensin causes relaxation of the gallbladder in humans and, by contributing to stasis, may be involved in the formation of gallstones.     

A normalization technique for 3D PET data

Prior to reconstruction, emission data from a multi-ring PET camera must be corrected (normalized) for variations in detector sensitivity. The appropriate correction coefficients are obtained by measuring the response of all coincidence lines to a calibrated source of activity (a blank scan). State-of-the-art cameras may contain up to a million such lines of response (LORs), and therefore around 400 million counts will be required to calibrate each LOR to a statistical accuracy of 5%. Alternatively, by modelling the LOR sensitivity as the product of the individual detector efficiencies and a geometrical factor, a calibration procedure has been proposed which requires the determination of only 6000 parameters from this same data set. A significant improvement in the statistical accuracy of the coefficients can therefore be expected. Recently, multi-ring scanners have been operated with the septa retracted, increasing the number of measured LORs by a factor of eight. The acquisition of the calibration data necessary to achieve adequate statistical accuracy then becomes prohibitive. We show that, by modelling the LOR sensitivity, it is possible, with certain approximations, to normalize a septa-retracted emission data set with good accuracy. The input to the model is a high statistics blank scan acquired with the septa extended, which offers a number of practical advantages.     

Trophic response of gut and pancreas after ileojejunal transposition.

OBJECTIVE: The authors determined whether ileojejunal transposition (IJT) stimulates the growth of the pancreas or the nontransposed segment of small intestine, and ascertained whether this trophic effect is altered by the location of transposed gut segment. SUMMARY BACKGROUND DATA: Transposition of the ileum to the proximal small intestine stimulates a marked mucosal growth of the transposed ileal segment; the cellular mechanisms responsible for this adaptive hyperplasia are not known. METHODS: The distal quarter of the small intestine (distal ileum) was transposed into the proximal (Type I), middle (Type II), or distal (Type III) portions of the remaining small intestine. On postoperative day 28, the pancreas and scraped mucosa from the segments of transposed ileum, proximal ileum, and duodenum were obtained, weighed, and examined for DNA and protein content. RESULTS: All types of IJT increased mucosal weight and DNA content of the transposed ileum. Types I and II IJT produced a significant proliferation of the pancreas and mucosa of the duodenum and proximal ileum. The magnitude of proliferative increases was greatest in Type I IJT. CONCLUSIONS: Ileojejunal transposition appears to be an excellent model to examine the mechanisms by which intestinal epithelial cells proliferate in response to luminal nutrients or humoral factors.