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Biomedical subjects

A Cantafora

Publications and source records attributed to A Cantafora.

102 records · Page 6Linked to original sources
PubMed1981

Sulfated bile acids in serum, bile, and urine of cirrhotic patients before and after portacaval anastomosis.

Sulfated and unsulfated bile acid composition was studied in serum and bile in 10 patients with alcoholic cirrhosis. Samples, collected before and 2 months after portacaval anastomosis, were analyzed using a gaschromatographic method. Mean total serum bile acid levels rose from 32.0 +/- 5.3 (SE) mumol/liter before to 87.4 +/- 13.3 mumol/liter after surgery (P less than 0.005). The increase in serum bile acid levels was significantly only with respect to the unsulfated fraction (22.7 +/- 3.0 mumol/liter to 67.6 +/- 8.1 mumol/liter, P less than 0.005). Thus the percent sulfation of total serum bile acid decreased from 24.6% to 19.2%. The sulfated bile acid fraction comprised mainly chenodeoxycholate both before and after surgery. Percent sulfation of individual bile acids was not modified after portacaval anastomosis. Bile acid sulfates were present in bile only in negligible amounts. The daily urinary excretion of bile acids, studied in 6 patients, increased significantly (P less than 0.05) after surgery, the increase being due only to the unsulfated compounds. Data from this study indicate that in cirrhotic patients no significant changes occur in serum with respect to sulfated bile acids after portacaval anastomosis, despite a definite increase in serum unsulfated bile acid levels. This is likely due to the lack of an efficient enterohepatic circulation of bile acid sulfates.

Adult↗
PubMed1981

Structure of biliary phosphatidylcholine in cholesterol gallstone patients.

The fatty acid composition of biliary phosphatidylcholine was analyzed in 13 patients with radiolucent gallstones undergoing elective cholecystectomy, and in 11 normolipemic patients without gallstone undergoing abdominal surgery. The only difference in the percentage fatty acid composition between the two groups was a significantly (p less than 0.05) higher percentage arachidonic acid in the first group. This acid was exclusively located in the sn-2 position of phosphatidylcholine (PC), accounting for 13.0 +/- 4.9% in the first group and 8.2 +/- 4.9% in the second (p less than 0.05). The percentage arachidonic acid of PC was negatively correlated (p less than 0.001) with the percentage biliary chenodeoxycholate in gallstone patients, but not in controls. Explanation of these findings is, at present, only speculative.

Adult↗
PubMed1980

Red blood cell fatty acid composition in a sample of Italian middle-aged men on free diet.

Within the framework of a project of primary prevention of coronary heart disease the erythrocyte fatty acid composition was determined in 140 Italian middle-aged men on free diet. The linoleic/oleic ratio ranged from 0.27 to 0.96 pointing out remarkable differences in dietary fat intake. A negative correlation was observed between erythrocyte linoleic/oleic ratio and plasma cholesterol levels. This gives indirect support to the validity of this ratio as an index of adherence to cholesterol-lowering diets in long-term studies.

Adult↗
PubMed1979

An improved gas-chromatographic method for the determination of sulfated and unsulfated bile acids in serum.

This study has been aimed at improving some steps in the gas-liquid chromatographic determination of sulfated bile acids. The best conditions for the enzymatic hydrolysis with cholylglycine hydrolase of sulfolithocholylglycine and sulfolithocholyltaurine are described. Recoveries of more than 85% were obtained after prolonging the incubation to 12 h. A single-step procedure for solvolysis and methylation of bile acids was achieved by using, as a water scavenger, 2,2-dimethoxypropane added directly to the hydrolysis mixture. This procedure avoided the difficulty of the extraction of sulfated bile acids from aqueous solutions.

Amidohydrolases↗
PubMed1979

Differences in serum bile acid composition between unoperated cirrhotic patients and patients with portacaval or mesocaval shunt.

Serum bile acids were determined in 13 cirrhotic patients with portacaval shunt and in 15 with mesocaval shunt. 20 nonshunted cirrhotics were used as controls. Serum bile acid levels were higher in portacaval (26.7 +/- 14.3 micrograms/ml) than in mesocaval shunt patients (16.9 +/- 8.1 micrograms/ml) and controls (14.1 +/- 11.5 micrograms/ml). The cholic/chenodeoxycholic ratio was lower after portacaval shunt than after mesocaval shunt (0.36 +/- 0.15 and 0.63 +/- 0.26, respectively). It is hypothesized that these findings may be consistent with a larger hepatic blood flow present in mesocaval shunted patients and with chenodeoxycholic absorption in the upper small intestine.

Adult↗
PubMed1977

Sertoli cells of adult rats "in vitro". A morphologic and functional study.

A cell line obtained from isolated seminiferous tubules of adult rat testis has been studied "in vitro" over a period of 35 days. Light and electron microscopic studies performed from hour 2 to the end of culture have shown the presence of a monomorphic cell population. After 5-6 days of culture the cells formed a monolayer. The cytoplasm of the cells contained numerous lipid bodies and produced numerous projections. The nucleus showed several indentations and one or more nucleoli. From the 9th to the 15th day of culture the cells developed a large amount of endoplasmic reticulum, Golgi apparatus and aggregates of electron dense granules. From the 20th to 40th day the cell cultures progressively degenerated. Immunochemical analysis of the culture medium revealed the presence of estradiol-17beta, which reached its maximum production rate from the 8th day to the 18th day of culture. Corresponding to cell involution estradiol concentration underwent a rapid decrease. On the basis of morphological and biochemical data the cells could be considered Sertoli cells.

Animals↗
PubMedDate not supplied

Age-related changes in blood and liver lipids of male Wistar rats.

The results of this study indicate that the age-dependent plasma cholesterol increase observed in male Wistar rats is correlated with changes in both the distribution of high-density lipoprotein fractions and the storage of hepatic cholesterol. Specifically, the lipoprotein distribution showed a significant increase in the proportion of HDL(1) and a symmetrical decrease in both the HDL(2) and HDL(3) fractions during the 3 month to 18 month age period. There were no significant changes in the very-low density and low-density lipoprotein fractions. The chemical composition of lipoproteins showed many age-related variations, especially in the proportion of cholesteryl ester and in the distribution of HDL subfractions. A study of fatty acyl composition of the major lipid classes showed that, within cholesteryl ester found in liver, there was an increase in the proportion of saturated fatty acids. Polyunsaturated fatty acids increased in the cholesteryl esters found in high-density lipoproteins of older rats. These observations suggest that the age-dependent accumulation of body cholesterol occurs by a reduced catabolism of HDL(1) fraction, and modifications in plasma and liver lipids.

Journal Article↗
PubMedDate not supplied

Neutral lipids production, transport, utilization.

Malignant tumors increase the levels of triacylglycerol carriers, i.e., very low density lipoproteins (VLDL), and lower the concentrations of cholesterol carriers, i.e., low-density and high-density lipoprotein fractions (LDL and HDL). The rise in VLDL levels may be caused by increased hepatic secretion of this lipoprotein fraction and reduced conversion of VLDL to LDL caused by cachexia-inducing proteins. The hypocholesterolemia is probably related to lowered LDL and HDL cholesterol levels that depend on a greater utilization of cholesterol for the biogenesis of new membranes and the accumulation of cholesteryl ester in tumoral tissue. The involvement of neutral lipids in cancer development is further evidence by the occurrence of certain tumors following the intake of high-fat diets. Furthermore, epidemiological and experimental studies showed that hypercaloric diets rich in n-6 polyunsaturated fatty acids (n-6, PUFA) stimulated tumorigenesis, while diets rich in marine fats (n-3, PUFA) inhibited it. In conclusion, changes ill neutral lipids production, transport and utilization play an importantly role in determining the alterations in energy storage and membrane properties observed in tumor cells.

Animals↗