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Biomedical subjects

A Gerolami

Publications and source records attributed to A Gerolami.

10 recordsLinked to original sources

Distinct effects of three bile salts on cholesterol solubilization by oleate-monoolein-bile salt micelles.

Micellar cholesterol solubilities in bile salt-monoolein-oleic acid systems have been determined. Whatever the bile salt/oleyl compounds ratio, taurochenodeoxycholate solubilizes more cholesterol than taurocholate and much more than tauroursodeoxycholate. At pH 6.7, the cholesterol solubility limit is about the same with either oleate or monoolein. Cholesterol solubility falls in oleate-bile acid mixtures as the pH is raised. The capacity for supersaturation with cholesterol is greater for bile salt-monoolein than for bile salt-oleate micelles. For the latter it decreases as pH increases.

Bile Acids and Salts

Effect of bile salts on the biliary excretion of glycodihydrofusidate in the rat.

The biliary elimination of glycodihydrofusidate (GDHF), a structural analogue of bile salts, was studied in bile fistula rats. GDHF was excreted in bile with a maximal excretory rate (Tm = 0.80 mumol min-1 kg-1) which is much lower than bile salts Tm. The effects of dehydrocholate and taurocholate on GDHF biliary secretion suggest a stimulatory effect of bile salts on canalicular excretion of the drug. (a) When a bolus intravenous injection of 3 mumol of GDHF was followed after 2 min by a continuous dehydrocholate perfusion (10 mumol min-1 kg-1), biliary excretion of GDHF was increased in comparison with control rats. (b) Upon attaining the biliary Tm by continuous perfusion of GDHF at a rate of 1.35 mumol min-1 kg-1, infusion with either taurocholate or dehydrocholate increased its Tm to a similar degree. These results are similar to those previously obtained with the effects of bile salt infusions on the Tm of bromosulfophthalein. They suggest therefore that hepatic transport of GDHF and bile salts occurs by routes which are distinct for canalicular transport in spite of the striking structural similarities between GDHF and bile salts.

Animals

Diet and cholesterol gallstones. A multicenter study.

In France, changes in the incidence of gallstones during the 20 years following World War II paralleled the changes in total calories, protein and lipid of the diet. The incidence of gallstones in autopsy statistics has been compared to the diets in different countries: France, India, Japan, Portugal, South Africa, Sweden and Uganda. Low calorie, low protein, low lipid intake and vegetable diet are associated with a low incidence of gallstones. A positive correlation between calorie intake and gallstones incidence was found at necropsy for calorie intakes lower than 3,000 kcal. In countries with high calorie, high protein and high lipid intakes, such a correlation was not found. These results suggest that a hypocaloric diet associated with a low intake of fat and protein mostly of vegetable origin, is protective against cholelithiasis.

Cholelithiasis

Diet and cholesterol gallstones. A further study.

In a first study, a population of 1,045 women from 20 to 61 years old has been studies. 24 (2.3%) were known to have gallstones. After excluding these 24 cases, 214 were drawn from the same population and accepted an oral cholecystography. 11 cases of stones (5.1%) were discovered. The diet of these 11 patients and of the 202 women without gallstones was not significantly different. In a second study, the diet of 50 patients with known gallstones and the diet of 50 matched controls have been compared. No significant difference between the two groups can be demonstrated for calories, protein, fat or carbohydrates intake. These results are compared to previous results which showed overconsumption of food in gallstone patients. The method for all studies being similiar, it seems that the dietetic factors are now less important in cholesterol stones pathogenesis than during the period which followed the second world war starvation in southeast France. The assumption that undernutrition diminishes the chance for a women to develop gallstones is proposed.

Adult

Controlled trial of chenodeoxycholic therapy for radiolucent gallstones. A multicenter study.

134 patients with radiolucent gallstones were randomly allocated to receive either placebo or 1 of 3 different doses of chenodeoxycholic acid (CDCA); 750, 1,500, or 3,000 mg). The initial dose was lowered if not well tolerated. 107 patients were treated for more than 3 months. Among them, stones dissolved in 21 and were smaller in 25 patients. Partial or complete dissolution occurred in 4 of the 13 receiving 375 mg/day, 14 of 37 receiving 750 mg, 24 of the 38 receiving 1,500 mg and 4 of 8 receiving 3,000 mg/day. The number of responders to the therapy was significantly greater in the groups of patients receiving 1,500 mg/day or 17-24 mg/kg body weight than in any other group. However, side effects, i.e., diarrhea and transaminase increase, are also dose related. It appears from this study that the optimal dose of CDCA may be between 17 and 20 mg/kg body weight.

Adult

Intrahepatic metabolism and secretion of biliary lipids.

The purpose of this work is to review the arguments which support the role of mixed micelle formation in the biliary secretion of lipids. These arguments are derived from in vitro physicochemical studies and from results obtained in vivo during biliary drainage in animals and in man. They show that, for the essential, mixed micelle formation between lecithins, cholesterol and bile salts can explain the biliary lipid secretion. The amount of lipids transported into the bile depends on the intrahepatic metabolism of cholesterol and lecithins. Different bile salts have opposite effects on the saturation of bile with cholesterol. During chronic administration of bile salts, the differences may be explained by specific actions on cholesterol metabolism and particularly on cholesterol absorption. On the contrary, during acute injection of bile salts, in most animal species, those bile salts which have the greatest ability of dissolving cholesterol in vitro (dihydroxy being more efficient than trihydroxy) are those which determine the greatest biliary secretion of cholesterol.

Animals