No abstract

ABSTRACT. Gastric carcinoid tumors were found in seven of 135 striped field mice (Apodemus agrarius) by routine histopathologic examination. All these carcinoids occurred in mature striped field mice aged 72-100 weeks. Six animals were females and only one was male. Only two of seven tumors were detectable by gross examination. Grossly, tumors were located in the fundus of the glandular stomach. All seven tumors were microscopically single in the stomach and two mice exhibited extragastric metastasis. Tumors from all the mice were characterized by densely packed sheets of round to polygonal cells, subdivided into packets by a fine fibrovascular stroma. The cytoplasm of all tumor cells from all the mice contained argyrophil granules when stained by Grimelius and Sevier-Munger silver procedures. All seven mice with gatric carcinoids exhibited positive immunoreactivity to neuron specific enolase. Psammoma bodies, concentrically laminated microcalcification, were characteristic findings in gastric carcinoids from five mice. There were also a concomitant and independent hepatocellular adenoma in one case and hepatocellular carcinoma in two cases. The present cases provide the first description of spontaneous gastric carcinoid tumors in the striped field mice. -KEY WORDS: gastric carcinoid tumor, striped field mouse.

Genetic polymorphisms in the coding exons of the CYP1A1 gene were analyzed in 100 Koreans. Three types of CYP1A1 polymorphisms, specifically G134A, G184C and A2455G, were identified with allelic frequencies of 18, 3, and 16%, respectively, and no linkage was observed among them. The novel G184C polymorphism identified in this study was associated with the mutation of an alanine residue at position 62 to proline. Other earlier-reported polymorphisms in the coding region of CYP1A1 were not detected.