We performed mass screening for gastric cancer by means of X-ray in Costa Rica from 1996 through 1999. Screening was performed on 10064 subjects and 69 gastric cancers were detected (screening group). During the same period 172 gastric cancer patients were referred to us (non-screening group). Results of screening in Japan (Japanese group) were quoted from the annual report of the Japanese Society of Gastroenterological Mass Survey. This study is a comparison of these 3 groups. The detection rate was 0.68% in the screening group, 0.11% in the Japanese group. The operability was 92.7%, 76.1%, 97.0%, the resectability 96.8%, 83.2%, 98.6%, the rate of early gastric cancer 64.5%, 30.3%, 65.9%, and the rate of curability A 79.0%, 38.5%. 82.6% in the screening group, non-screening group and Japanese group respectively. The results in the screening group were exactly equal to those in the Japanese group. These results show that the same results can be obtained in Costa Rica as in Japan, if screening is performed with the same diagnostic level and skill as in Japan.
To elucidate the morphological feature of portal hypertensive colopathy (PHC), the macroscopic and microscopic vascular alterations of colonic mucosa was observed in rats with thioacetamide-induced liver cirrhosis. The colered latex was injected into the portal vein and filled the peripheral veins on the colonic mucosa. Histologic study revealed an increased in the number of the cross sections of venous vessels containing the colered lactices in the lamina propria mucosa (LP), lamina submucosal (SM) and muscularis propria (MP) in the cirrhotic rats. Stereoscopic results of the vascular cast obtained from the cirrhotic rats showed the presence of two characteristic vascular sings, i.e., winding and tree like dilated vessels (WT) and vascular ectasia (VE). WT was characterized by tortuosity, dilatation and increase of the venous vessels in the LP, SM and MP, and VE was vascular spider-like lesion mainly in the LP or a clump of tortuous vessels in LP, SM and MP. In the clinical study, 38 patients with liver cirrhosis and 40 normal control received colonoscopic examinations. The vascular lesions similar to WT and VE were seen in 78.9% and 65.8% of cirrhotic patients, compared to 10.0% and 7.5% in the control. The differences were statistically significant indicated that WT and VE were thought to be the typical experimental models of PHC. Since the cirrhotic rats used the present study were administered thioacetamide for only 12 weeks, it was suggested that PHC could occurred even in early stage of liver cirrhosis with mild portal hypertension. Neither WT nor VE were associated with the Child-Pugh's grade of cirrhosis.