Search PubMed⌕ Search

Biomedical subjects

E Vinnars

Publications and source records attributed to E Vinnars.

120 records · Page 7Linked to original sources
PubMedDate not supplied

Preliminary studies of energy-rich phosphagens in muscle from severely ill patients.

Preliminary studies on muscle tissue metabolism were made in a series of 18 patients treated in an intensive care unit. In acutely ill patients with circulatory or respiratory insufficiency, there was an increase in muscle lactate content, a decrease in the phosphorylcreatine stores as well as decreased in adenosine triphosphate (ATP) and total adenine (TA) contents. These findings could partly be explained by a relative hypoxia in the muscle but acute hypoxia alone would not account for the decrease in ATP or TA. These changes in the adenylate pool were still more pronounced in patients with prolonged diseases. In this series the ATP content was only 50% of the normal, despite normal lactate content. The reason for the low adenine nucleotide level in muscle tissue is thought to be due primarily to an increased formation and deamination of adenosine monophosphate during hypoxia in combination with a decreased rate of purine synthesis in the liver and/or a decreased capacity for "purine salvage" in the muscle. This itself might, in turn, be mediated by a low energy state in muscle or liver or be due to other metabolic disturbances or tissue damage. It was found that prolonged immobilization without metabolic disturbances did not change the TA content in muscle, while short-lasting severe metabolic acidosis decreased the TA content. A correction of the metabolic disturbance immediately increased the TA content in muscle. A low energy charge potential was found in patients with prolonged diseases, possibly being the cellular expression for the concept of the post-traumatic catabolic state.

Adenine↗
PubMedDate not supplied

Protein synthesis in skeletal muscle in relation to nitrogen balance after abdominal surgery: the effect of total parenteral nutrition.

Protein synthesis in skeletal muscle was studied in patients after elective abdominal surgery, using the concentration and size distribution of ribosomes. The patients were given either an electrolyte solution or total parenteral nutrition postoperatively. The analyses were performed on muscle biopsy specimens taken prior to surgery and on days 1 and 3 following surgery. The percentage content of polyribosomes, total ribosome concentration and the polyribosome concentrations per milligram of tissue DNA were determined. Elective abdominal surgery caused a significant decrease (p less than 0.05) in the three variables. Total parenteral nutrition did not prevent the decrease. The negative nitrogen balance was significantly improved by total parenteral nutrition, but it did not reach equilibrium. The results show that total parenteral nutrition given postoperatively did not maintain protein synthesis activity in skeletal muscle. The improvement in nitrogen balance suggests that amino acids are utilized by tissues other than skeletal muscle.

Cholecystectomy↗
PubMedDate not supplied

Role of glutamine and its analogs in posttraumatic muscle protein and amino acid metabolism.

Skeletal muscle protein catabolism following trauma has until recently not been possible to counteract by intravenous nutritional means. The obligatory loss of nitrogen with concomitant reduction of skeletal muscle protein synthesis is also accompanied by a decrease of muscle free glutamine, the extent of which is proportional to the muscle protein catabolism. Serving as a human model of surgical trauma, patients undergoing elective cholecystectomy were given total parenteral nutrition including additions of either glutamine or its analogs (ornithine-alpha-ketoglutarate, alpha-ketoglutarate, or alanylglutamine) during 3 postoperative days. The polyribosome concentration and the intracellular glutamine concentration in skeletal muscle, as well as nitrogen balance, showed a less pronounced skeletal muscle catabolism in these groups than when conventional total parenteral nutrition was given. It is concluded that a support of either glutamine or its carbon skeleton, alpha-ketoglutarate, counteracts the postoperative fall of muscle free glutamine and of muscle protein synthesis. Furthermore, statistical correlations could be shown between the changes of muscle glutamine and muscle protein synthesis and the postoperative nitrogen losses.

Amino Acids↗
PubMedDate not supplied

Long-term effect of glycyl-glutamine after elective surgery on free amino acids in muscle.

In order to evaluate the long-term effect of total parenteral nutrition supplemented with glutamine after surgery, patients (n = 17) undergoing elective abdominal surgery were randomized into two groups and studied for 30 days after surgery. During the 3 days immediately after surgery, one group (n = 8) was given total parenteral nutrition including a conventional amino acid solution (control group). The other group (n = 9) was given isocaloric and isonitrogenous total parenteral nutrition including the same amino acid solution supplemented with the dipeptide, glycyl-glutamine (GLN group). Oral food intake started on the third postoperative day and was gradually increased at will. The concentration of free amino acids in percutaneous muscle biopsy specimens was determined preoperatively and on days 3, 10, 20, and 30 after the operation. Free glutamine decreased in skeletal muscle in the control group on days 3 and 10 by 32.2 +/- 5.4% (p < .01) and 20.1 +/- 6.9% (p < .05), respectively. In the glycyl-glutamine group, the decrease in glutamine was delayed until day 10 when it was 22.1 +/- 8.1% (p < .05). The glutamine levels were restored on days 20 and 30 in both groups. Total parenteral nutrition supplemented with glutamine maintained the free glutamine levels in skeletal muscle after surgery, but when treatment was discontinued, the glutamine concentration in muscle dropped, despite a normal enteral dietary intake.

Amino Acids↗
PubMedDate not supplied

Effect of epidural analgesia on muscle amino acid pattern after surgery.

Free amino acids in muscle were studied before and 96 hours after skin incision in 14 patients undergoing elective hip replacement and allocated to general anesthesia or epidural analgesia (T10-S5) effective before incision and maintained with intermittent 0.5% bupivacaine during the first 24 postoperative hours. The general anesthesia group (n = 8) showed the characteristic changes in muscle amino acids, with increase of branched chain amino acids and phenylalanine and decreased glutamine, arginine and lysine, as well as raised plasma levels of cortisol and glucose. The epidural group (n = 6), contrastingly, showed no significant changes in plasma cortisol and glucose and an attenuated postoperative response in all amino acids, without significant difference from the preoperative values. Differences in postoperative muscle amino acid concentrations between the epidural and the general anesthesia group were significant as regards glutamine, valine and asparagine. These results suggest that post-trauma changes in muscle amino acids are predominantly mediated by afferent neurogenic stimuli and the secondary increase in catabolic hormones.

Aged↗