From 1986 to 1990 a prospective comparative study was undertaken to compare the relative accuracy of computed tomography, endogastric ultrasonography, and intraoperative surgical assessment in evaluating the depth of invasion (T category)

We undertook a prospective study to determine whether endoscopic ultrasound is useful in the preoperative staging of tumours of the oesophagus. We found clear evidence that it is a more reliable clinical tool than computed tomography in TN staging of these tumours.

In order to localise neuroendocrine tumours of the foregut type (that is, of the stomach, duodenum, and pancreas), 18 patients were studied prospectively by endoscopic ultrasonography, computed tomography, transabdominal ultrasonography, magnetic resonance imaging, and somatostatin receptor scintigraphy. These 18 patients had a total of 25 primary tumour lesions which were verified histologically in tissue obtained by surgery or by ultrasound or endoscopy guided biopsy.Tumours were found in the stomach (n=-), duodenum (n=6), pancreas (n=17), and liver (n=l). Endoscopic ultrasonography had the highest sensitivity for tumour detection, followed by somatostatin receptor scintigraphy, computed tomography, transabdominal ultrasonography, and magnetic resonance imaging (88%, 52%, 36%, 32%, and 24% respectively). Endoscopic ultrasonography was especially sensitive in tumours smaller than 2 cm in diameter (88% v somatostatin receptor scintigraphy 35%; computed tomography 12%; transabdominal ultrasonography 6%; and magnetic resonance imaging 0%). Of 17 tumours located in the pancreas, endoscopic ultrasonography showed a sensitivity of 94% (somatostatin receptor scintigraphy 47%; computed tomography 47%; transabdominal ultrasonography 41%; and magnetic resonance imaging 29%). Of eight extrapancreatic tumours, six were identified by endoscopic ultrasonography, five by somatostatin receptor scintigraphy, and only one by computed tomography, transabdominal ultrasonography, and magnetic resonance imaging. One neuroendocrine tumour that was not detected by endoscopic ultrasonography was correctly identified by somatostatin receptor scintigraphy. Endoscopic ultrasound allowed correct determination ofthe tumour size and tumour spread into parapancreatic structures, especially the large vessels (T stage), in all 14 patients operated upon. The lymph node stage (N stage) was correctly determined in 10 of these 14 patients. In summary, endoscopic ultrasonography and somatostatin receptor scintigraphy were the most sensitive imaging methods for the localisation of these tumours and should be used as early diagnostic procedures to accurately stage neuroendocrine tumours of the foregut type. (Gut 1994; 35: 471-475)

A system was developed to study the binding of Listeria monocytogenes-specific T cells to L. monocytogenes-pulsed macrophages as an analogue of the initial phase of T-cell activation: antigen recognition. Specific binding, demonstrable after a brief (1 h) contact, was quantitated by the depletion of L. monocytogenes-specific T-cell activity in the cells nonadherent to L. monocytogenes-pulsed macrophage monolayers. L. monocytogenes-specific T-cell function was measured by its ability to activate L. monocytogenes-pulsed macrophages, both to secrete a protein mitogenic for thymocytes and to effect nonspecific tumoricidal activity. These manifestations of T-cell function are known to be regulated by products of I region of the H-2 gene complex. Studies designed to determine the role of H-2 gene products in specific T-cell-macrophage binding have revealed the following. T cells bind specifically to syngeneic macrophages and poorly to allogeneic macrophages. The binding ability appears to map to the K end of the H-2 gene complex (K through I-E). At least two distinct populations of B6AF1 T cells with binding avidity for L. monocytogenes presented on parental macrophages can be identified. Finally, the binding of a given parental-reactive B6AF1 T-cell clone can be specifically inhibited by pretreatment of the antigen-pulsed B6AF1 binding macrophage with anti-H-2 (anti-Ia) antibodies reactive with the appropriate parental haplotype. These results strongly suggest that H-2 gene products play a direct role in mediating the specific binding of T cells to macrophages and imply that the antigen-dependent physical interaction between T cells and macrophages is the initial, and determining, event in some forms of H-2 gene control of immune reactivity.

Primary motility disorders of the esophagus require the exclusion of intramural tumors. The procedures currently used for the differential diagnosis of achalasia such as endoscopy with biopsy, esophageal and gastric radiography, abdomino-thoracic computed tomography and intraluminal esophageal manometry, are unsatisfactory when a tumor growing intramurally is suspected. A more recent method of studying the integrity of the gastrointestinal wall and its surrounding tissue is endoscopic ultrasonography. In 16 patients suspected of having achalasia, endosonography was performed in addition to the above-mentioned conventional examinations. Fifteen of them showed a normal ultrasonic structure of the wall of the gastro-esophageal junction, with no sign of hypertrophy of the smooth muscle layer. In the remaining case endoscopic ultrasonography was able to detect an intramural tumor, as evidenced by the inhomogeneous ultrasonic structure of the esophageal wall. Computed tomography and all the other conventional diagnostic procedures used failed to demonstrate this tumor. In conclusion, the findings presented strongly suggest that endosonography can contribute to the differential diagnosis of achalasia and intramural tumors.