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S Rojas

Publications and source records attributed to S Rojas.

35 records · Page 2Linked to original sources
PubMed1985

Effects of ethanol ingestion on amino acid uptake in the dog liver in vivo.

The effect of ethanol ingestion on the uptake of labeled amino acids was studied in the in situ autoperfused dog liver. Ethanol was administered orally, as a 15% water solution, in a dose of 4 g/kg body weight/day as the only source of water for 2 days. Amino acid uptake was measured in anesthetized dogs by means of the single-passage, multiple-tracer dilution technique. In control animals, hepatic uptake of 14C-glycine, 3H-alpha-aminoisobutyric acid (3H-AIB) and 3H-L-leucine were 50, 15 and 66%, respectively. In the ethanol-treated dogs, glycine and AIB uptake was reduced by 70 and 63%, respectively. L-leucine uptake was reduced by only 23%. The plasma concentration of the naturally occurring amino acids was significantly increased after ethanol treatment, probably due to a reduced influx into hepatocytes. Simultaneous measurements of hemodynamic parameters showed a significant increase in the portal vein pressure of ethanol-treated animals, whereas the portal vein blood flow and hepatic extracellular volume were unaffected.

Amino Acids↗
PubMed1981

Decreased bioavailability of prednisone due to antacids in patients with chronic active liver disease and in healthy volunteers.

To investigate the potential action of antacids on prednisone absorption and on prednisolone serum levels, we studied 5 healthy volunteers and 12 patients with chronic active liver disease. Six patients responded to treatment and 6 did not. After administering two 5-mg tablets of prednisone with 60 ml of water, 60 ml of Melox (AlOH 3.75 g/100 ml + MgOH 4.0 g/100 ml), or 60 ml of Aldrox (AlOH 8.0 g/100 ml + MgOH 1.95 g/100 ml), we measured prednisolone by radioimmunoassay. Both peak heights and areas under the serum-concentration curves were significantly reduced when prednisone was administered with antacids. The relative bioavailability of prednisone after prednisone-antacid treatments compared to that after prednisone-water treatment was 74% +/- 13% (p less than 0.05) with Melox and 57% +/- 15% (p less than 0.01) with Aldrox in healthy volunteers. In patients with chronic active liver disease responding to treatment, prednisone bioavailability was 65% +/- 120% (p less than 0.01) and 87% +/- 20%, respectively. Among patients with chronic active liver disease not responding to treatment, this parameter was 76% +/- 12% (p less than 0.05) and 80% +/- 21% (p less than 0.05), respectively. To insure adequate prednisolone levels in patients with chronic active liver disease, prednisone should not be given simultaneously with antacids.

Adult↗
PubMed1975

Polyamines and ornithine decarboxylase activity during growth and differentiation in Blastocladiella emersonii.

The activity of ornithine decarboxylase (EC 4.1.1.17, L-ornithine carboxy-lyase) was determined during the life cycle of Blastocladiella emersonii. The specific activity of the enzyme was found to be low in the zoospores, to rise 20-fold during germination and early growth, to fall during growth and to rise again during sporulation. This rise in enzyme activity was shown to be dependent on protein synthesis. Putrescine levels, on a per mg of protein basis, paralleled the fluctuation found in ornithine decarboxylase activity. Putrescine and spermidine were the only polyamines found in extracts of B. emersonii.

Blastocladiella↗
PubMedDate not supplied

Effect of ethanol on human placental transport and metabolism of adenosine.

It has been suggested that adenosine is involved in the acute effects of ethanol in a number of tissues. The present study was undertaken to evaluate the role of adenosine on the vascular responses of perfused isolated human placental cotyledons after the acute administration of ethanol. The possibility that ethanol may effect the uptake and metabolism adenosine was also investigated. Uptake of adenosine was studied using the single-circulation paired-tracer dilution technique. Both adenosine and ethanol caused a dose-related increase in perfusion pressure of placental lobules. Pharmacologically relevant concentrations of ethanol (10-65 mM) significantly inhibited the uptake of [3H]adenosine between 25 and 50 per cent. Thin-layer chromatographic analysis of the perfusate after the administration of ethanol showed in a 17.9 +/- 0.6 per cent reduction of [3H]adenosine metabolism. These findings support the working hypothesis that placental adenosine, at least partially, mediates the placental disturbance elicited by the administration of acute ethanol, which may contribute to the pathogenesis of fetal alcohol syndrome.

Adenosine↗
PubMedDate not supplied

[Furosemide-amiloride combination in the treatment of ascitic-edema in patients with hepatic cirrhosis].

The combination of furosemide-amiloride was used in the management of fluid retention in 16 cirrhotic patients. The study lasted 60 days. In 15 out of the 16 patients a clinical response was observed, namely increased urinary volumen and reduction of abdominal girth. The body weight was reduced by a mean of 7.7 Kg. Serum potassium rose, within normal limits, in 14 patients and a reduction of urinary potassium elimination was observed. Mild hepatic encephalopathy was noticeable in 3 cases, rapidly responding to treatment reduction or withdrawal. The combination of furosemide-amiloride seems to be of value in the management of fluid retention in liver cirrhosis and is uncommonly associated to side effects.

Adult↗