Incidence and treatment of periampullary duodenal cancer in the U.S. veteran patient population.

BACKGROUND: Because fewer than 1000 cases of primary adenocarcinoma of the duodenum have been reported, earlier series are limited by local referral patterns and the long periods of time needed for retrospective reviews. METHODS: This study reports the outcomes of preiampullary duodenal adenocarcinoma treatments in all hospitals of the Department of Veterans Affairs from 1987 through 1991, using computer and tumor registry records. Patients were grouped by their most aggressive treatment (resection > operative bypass > percutaneous biliary intubation) and survival calculated from the date of this procedure. RESULTS: Of 2185 patients with periampullary cancers (1753 pancreatic, 432 other periampullary), 85 were duodenal and thus comprised only 4% of periampullary tumors. Thirty-four duodenal cancers were resected, 44 bypassed, and 7 had biliary intubation, with 30-day mortality rates of 6%, 18%, and 0%, respectively. Mean survival exceeded 1 year in all groups, and resection resulted in a significant increase in mean survival (784 vs. 438 days for nonresection, P = 0.01). The projected 5-year survival rate after resection was 23%. Mean survival after resection of 9 Stage I-II cancers was 668 days, but was similar after 5 resections with nodal or other metastases. Similarly, survival did not correlate with cancer stage in 13 palliated patients. CONCLUSIONS: This large study of patients with duodenal cancer provides a unique perspective of disease prevalence and response to surgical treatment. Prolonged survival is common with any treatment, but the longest survivals were after resection.

Picomolar platelet-activating factor mobilizes Ca to change platelet shape without activating phospholipase C or protein kinase C; simultaneous fluorometric measurement of intracellular free Ca concentration and aggregation.

The purpose of this study was to investigate signal transduction mechanisms activated by low and high concentrations of platelet-activating factor (PAF) in rabbit platelets and to contrast the responses to those induced by thrombin. We measured changes in intracellular free calcium ([Ca++]i) with fura2, while monitoring light scatter simultaneously as a measure of shape change and aggregation in a dual-excitation dual-emission spectrofluorometer. An abrupt 20% fall in light scatter, coincident with the peak of the [Ca++]i, indicated shape change in Ca-containing or Ca-free medium and was blocked by BAPTA loading and 10 microM cytochalasin B. A secondary decline in light scatter, indicating aggregation, occurred only in Ca-containing medium and only under conditions favoring protein kinase C (PKC) activation. PAF at 10(-12) M did not increase 1,4,5-inositol triphosphate content, which suggested PKC would not be activated. However, PAF at 10(-12) rapidly increased [Ca++]i to 900 nM in 7 sec seemingly by Ca influx through receptor-operated channels inducing shape change. PAF at 10(-9) and 10(-8) M increased [Ca++]i to 2 microM in 12 sec and induced both shape change and aggregation. However, in platelets pretreated with 100 nM staurosporine to inhibit protein kinases, 10(-9) M PAF did not cause aggregation even though [Ca++]i still rose to 2 microM, which indicated that PKC plays a role in aggregation but not in Ca++ mobilization.(ABSTRACT TRUNCATED AT 250 WORDS)