Biomedical subjects

A J Petersen

Publications and source records attributed to A J Petersen.

3 recordsLinked to original sources

PubMed1992

Branched-chain amino acids increase the seizure threshold to picrotoxin in rats.

During infusion of branched-chain amino acids (BCAAs) in humans, changes in ventilatory drive, appetite, and sleep have been reported. The mechanism by which BCAAs exert their effects on CNS remains unclear. Picrotoxin is a proconvulsant drug, acting as an antagonist on the GABA-benzodiazepine receptor complex. Twenty rats were randomized to receive either an IP injection with 4% BCAAs (300 mg/kg; 8 ml/kg) (n = 10) or placebo (saline 8 ml/kg) (n = 10). The mean latency time from injection to onset of seizures was recorded as an indication of the seizure threshold. Latency time was significantly longer for BCAAs than for placebo, 11.2 (+/- 1.9) vs. 8.3 (+/- 1.8) min. Thus, a BCAA injection increased the seizure threshold to picrotoxin (p < 0.03). This suggests that BCAA infusion may exert effects on the GABA-benzodiazepine receptor complex.

Amino Acids, Branched-Chain↗

PubMed1990

[Fluid therapy changes in surgical treatment of abdominal aortic aneurysm].

The use of blood components and blood substitutes was studied in 25 patients undergoing surgical treatment for abdominal aortic aneurysm in 1983, and was compared with the use of such components in 44 patients operated in 1988. The use of blood components had decreased by 49% from 1983 to 1988. In 1988, erythrocytes were administered only when the hemoglobin concentration fell under 9 g/100 ml. The use of plasma postoperatively was reduced to a minimum. Normovolemia was maintained with polygeline, dextran, electrolytes and autotransfusion. The change in transfusion praxis did not lead to any reduction in postoperative hemoglobin values. The stay in hospital and the number of hours spent in a respirator were both reduced, and there was a general improvement in results.

Aorta, Abdominal↗

PubMed1968

Solid ion-exchange electrode selective for calcium ion.

A calcium-selective electrode with solid ion exchanger was prepared from a solution of the calcium salt of a dialkylphosphoric acid in collodion. The electrode responds rapidly and reproducibly to activity of calcium ion and demonstrates a selective response for calcium ion in the presence of alkaline earth and alkali metal cations.

Calcium↗