Browsing by Author "GOMEZ, G"

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    EARLY STAGES OF GALLSTONE FORMATION IN GUINEA-PIG ARE ASSOCIATED WITH DECREASED BILIARY SENSITIVITY TO CHOLECYSTOKININ
    (1992) POSTON, GJ; SINGH, P; DRAVIAM, E; YAO, CZ; GOMEZ, G; THOMPSON, JC
    The purpose of this study was to measure differences in gallbladder sensitivity to cholecystokinin (CCK) in vivo during the early stages of gallstone formation and to correlate these findings to gallbladder CCK receptors. Guinea pigs were placed on either a normal diet or a two-week cholelithogenic diet, after which gallbladder emptying pressure to exogenously administered CCK was measured in vivo. according to the presence or absence of gallstones. At all doses of CCK tested (except 10(-10) mol/kg), the gallbladder response to CCK of guinea pigs that did not develop gallstones (on the cholelithogenic diet) was more sensitive than that of guinea pigs that did develop gallstones. Neither group was different from guinea pigs on a normal diet. In a second experiment, CCK receptors were measured on gallbladder muscularis from guinea pigs after two weeks on the same diet as in the first experiment. Those guinea pigs that did not develop gallstones had greater concentrations of CCK receptors (149 +/- 9 fmol/mg protein) than those that did develop gallstones (70 +/- 23 fmol/mg protein). Neither group was different from normal diet guinea pigs (119 +/- 57 fmol/mg protein). At the time point measured, there were no differences in the lipid chemistry or protein concentrations of gallbladder bile between the guinea pigs on the cholelithogenic diet that did or did not develop gallstones, or those on normal guinea pig chow. We conclude that the early stages of gallstone formation in guinea pigs are associated with decreased gallbladder sensitivity to CCK and that this change may be due to a lower concentration of CCK receptors on the gallbladder smooth muscle.
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    FREQUENCY OF GALLBLADDER CANCER IN CHILE, A HIGH-RISK AREA
    (1988) NERVI, F; DUARTE, I; GOMEZ, G; RODRIGUEZ, G; DELPINO, G; FERRERIO, O; COVARRUBIAS, C; VALDIVIESO, V; TORRES, MI; URZUA, A
    We report an autopsy study of gallbladder cancer prevalence in Chile, where the risk of this disease is among the highest reported world-wide. In 14,768 autopsy protocols obtained from 3 university hospitals, 45% of women and 20% of men older than 20 years had gallstone disease (the major known risk factor for gallbladder cancer). The prevalence of gallbladder cancer in Chileans was compared to that found in a Swedish-Czechoslovakian autopsy study previously published. These countries were chosen because of their high frequency of gallstone disease. The comparison was performed by using logistic regression models adjusting for possible differences in the age-sex structure or the true incidence of gallstones in both populations. We found that the most important single risk factor for gallbladdr cancer in Chile was gallstone disease, with an estimated effect on the logistic scale meaning that the cancer risk for subjects with gallstones is seven times higher than for those without the disease. Second in importance was the risk for sex, women being 2.8 times higher than for men. The estimated difference in the sex composition and the incidence of gallstones resulted in 17.9% higher odds of cancer in Chile than in Sweden and Czechoslovakia. However, this difference was not significant. This study suggests that the major etiologic factors of gallbladder cancer in Chileans, Swedes and Czechoslovakians are primarily related to gallstone disease.