Somatostatinoma/inhibitory syndrome: a statistical evaluation of 173 reported cases as compared to other pancreatic endocrinomas.

Somatostatin is known to inhibit the secretory release of other peptide hormones. Somatostatinomas associated either with or without somatostatinoma (inhibitory) syndrome are rare neoplasms among gut-pancreatic endocrinomas. Collected from international literature, this study aimed to perform a statistical analysis on 173 patients with somatostatinoma/inhibitory syndrome. The evaluation further attempted to provide investigators in this particular field of research with extensive and precise information on the present situation of somatostatinoma. The 173 patients consisted of 81 with pancreatic somatostatinomas and 92 with extrapancreatic somatostatinomas. Most of the latter were found to have originated in the duodenum and may be termed as carcinoid somatostatinoma. Where data were considered to be adequate, a comparative study was carried out between two groups, pancreatic and duodenal, each consisting of 81 patients. A statistically significant difference between these two groups was found in the incidence of inhibitory syndrome (18.5% versus 2.5%) and von Recklinghausen's disease (1.2% versus 43.2%), large size of tumor (>20 mm) (85.5% versus 41.4%), multisecretory activities (33.3% versus 16.3%), and presence of psammoma bodies (2.5% versus 49.4%). There was no statistically significant difference in the rate of metastases and malignancy between the two groups. The average postoperative 5-year survival rate was 75.2% in 90 patients overall, 59.9% in 44 with metastases and 100.0% in 46 without metastases. Compared with the other pancreatic endocrinomas, including PPomas, glucagonomas, vipomas, gastrinomas, and insulinomas, somatostatinomas were characterized by the low rate of the relevant syndrome and multiple endocrine neoplasia syndrome type 1. There was a low rate of multiplicity, and a high incidence of psammoma bodies in the duodenal group particularly with von Recklinghausen's disease. A high rate of malignancy was recorded, resulting in a low postoperative survival rate of patients with metastases. In conclusion, somatostatinomas exhibited characteristic features quite different from those of the other pancreatic endocrinomas regarding multiple points.     

Polymerization of propene with zirconocene-containing supported catalysts activated by common trialkylaluminiums

This paper reports on propene polymerization conducted with modified Kaminsky-type catalysts activated by common alkylaluminiums. Several kinds of heterogeneous catalysts containing zirconocene were prepared by supporting Et[IndH₄]₂ZrCl₂, iPr(Flu)(Cp)ZrCl₂ and Cp₂ZrCl₂ on A1₂O₃, SiO₂, MgO, MgCl₂, MgF₂, CaF₂ and AlF₂ using an impregnation method. When Al₂O₃, MgCl₂, MgF₂, CaF₂ and AlF₃ were used as carriers, the resulting catalysts were easily activated by common trialkylaluminiums to give isotactic, syndiotactic and atactic polypropene in fairly good yields, whereas the other supported catalysts, combined with common trialkylaluminiums, did not show any polymerization activity. However, highly active catalysts were obtained by supporting the zirconocene compound on SiO₂ that had been reacted with a small amount of methylaluminoxane. The use of C1-containing alkylaluminiums always killed the catalyst activity.     

Studies on the roentgenological differentiation between complex and simple bowel obstruction

We studied 81 cases of organic bowel obstruction. In complex obstruction 7 cases out of 25 (28%) were diagnosed on the plain film before operation, although in simple obstruction 54 cases out of 56 (96%). But in retrospective evaluation of the plain films, we noticed that in some cases of complex obstruction, marked small bowel obstruction and ascites were seen from the onset, which were never seen in simple obstruction. We considered this finding as the key point for the roentgenological differentiation between complex and simple obstruction.     

Ultrastructural study of a rectal carcinoid showing direct contact with nerves

A small carcinoid was found in the rectum of a 55-year-old man, who had neither subjective symptoms nor the carcinoid syndrome. His serum serotonin level was within normal limits. Under a light microscope, the tumor was found to be a mixed type carcinoid which had infiltrated the submucosal layer, and showed a negative reaction to Grimelius' argyrophil staining. The ultrastructural study indicated that the tumor cells possessed the characteristically round granules and occasional direct contact with unmyelinated nerve fibers. But, no synaptic figure was encountered. Schwann-like cells were often observed surrounding these tumor cell-nerve fiber complexes. These findings may indicate that carcinoids have an affinity to the nervous tissue. This study was presented at the 25th Annual Meeting of the Clinical Electron Microscopy Society of Japan, Matsumoto, September 28–30, 1993.     

Difference in calcium metabolism following Billroth-I and Billroth-II procedures for gastric and duodenal ulcers

There have been 7 patients with postoperative osteomalacia in our series of 500 patients who had a gastrectomy for gastric or duodenal ulcers. All seven of these patients had a Billroth-II type gastrojejunostomy or esophagojejunostomy which caused food to bypass the duodenum and the upper part of the jejunum, and six of these patients showed milk intolerance and had diarrhea on food other than cow's milk. From this finding, it may be surmised that patients are predisposed to osteopenia after gastrectomy due to disorder in the process of calcium absorption and they develop osteomalacia when treated with the Billroth-II procedure, showing milk intolerance and diarrhea on food other than cow's milk.