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Biomedical subjects

J Larsson

Publications and source records attributed to J Larsson.

At least 253 records · Page 14Linked to original sources

Metabolic studies in severe burns. Clinical features, routine biochemical analyses, nitrogen balance and metabolic rate.

The effects of two isocaloric regimens for parenteral nutrition were compared on days 2 to 8 after severe burns in 16 patients. Energy expenditure, plasma catecholamines, biochemical variables and N-balance were measured. The 8 patients in group I, with mean burn size 55/25%, received fat and glucose, while the 8 in group II, mean burn size 60/40%, were given 24 g amino acid nitrogen daily in addition to the fat and glucose. The mean metabolic rate on days 2-8 after burning was 70 +/- 7 and 69 +/- 5 kcal/m2/h in groups I and II, respectively. The mean values for plasma noradrenaline in the same period were 8.35 +/- 0.89 and 7.9 +/- 0.77 nmol/l. The biochemical changes showed a pattern typical of burns. There were no intergroup differences except for urea, which was significantly higher in the group (II) receiving amino acids. The cumulative N-balance was markedly less negative 8 days after trauma (-24 g N +/- 8 g) in group II than in group I (-100 g N +/- 10 g). These results indicate that a high nitrogen intake, together with adequate energy supply, improves the N-balance significantly in the early post-burn period. The high-energy supply from fat and glucose did not seem to cause the patients additional stress.

Adolescent↗

Isolation and partial characterization of a low molecular weight trypsin inhibitor from human urine.

A low molecular weight glycoprotein which completely inhibited trypsin at a 1 : 1 molar ratio was isolated from human urine. It was generated from a precursor molecule which in turn derived from plasma inter-alpha-trypsin inhibitor. It had one polypeptide chain with a molecular weight of about 20 000 and a high content of half-cystine residues. Its amino-terminal amino-acid sequence was Val-Thr-Glu-Val-Thr-X-Leu-Glu-Asp-.

Alpha-Globulins↗

Metabolic studies in multiple injured patients. Clinical features, routine chemical analyses and nitrogen balance.

The effect of three different isocaloric parenteral nutritional regimes has been investigated in the early postoperative period in 19 patients with severe multiple injuries. Clinical course, biochemical analyses and nitrogen balance were monitored. The first group received glucose and insulin (n = 7), the second group fat and glucose (n = 6) and the third group fat, glucose and 24 g aminoacid-nitrogen (n = 6). The clinical course was similar in the three groups and all patients survived. The biochemical changes showed a typical pattern for trauma and there were no differences between the groups except for urea, which was significantly higher in the group receiving amino acids. The cumulative nitrogen balance was markedly less negative one week after trauma (-45 g N +/- 8) in the group given amino acids, glucose and fat compared to those given isocaloric amounts of glucose (-84 g N +/- 12) or glucose and fat (-95 g N +/- 10). This improvement in nitrogen balance was probably mainly due to an increase in protein synthesis.

Adolescent↗

The occurrence of paracrystalline mitochondrial inclusions in normal human skeletal muscle.

Two different types of paracrystalline mitochondrial inclusions identical with or very similar to those already described in the literature for a variety of muscle diseases were found in human skeletal muscle biopsies obtained under general anesthesia before ischemia and after various periods of anoxia up to 150 min. As these crystalloids could be observed in seven of 14 healthy subjects and occurred in five of these seven cases either before or only 10 min after onset of ischemia, it is suggested that such mitochondrial inclusions develop not only under the influence of variant noxious stimuli, but may also represent a normal constituent of human skeletal muscle mitochondria.

Adolescent↗

Biochemical changes associated with severe trauma.

The effects of different intravenous nutritional regimens on a number of biochemical indices of nutritional status were studied during the 8-day period following severe trauma. The inclusion of large amounts of amino acids (high nitrogen (N) was shown to greatly improve N balance over an isocaloric regimen containing no amino acids (O g N). The concentration of serum albumin, transferrin, prealbumin, and retinol-binding protein all fell during the study period in both patient groups, whereas the serum concentrations of acute phase reactants and of ribonuclease increased in the two groups. The sum of plasma levels of branched-chain amino acids and the essential amino acids was increased to a greater extent in the high N group. These amino acid totals and the ratio of glycine/valine showed a significant correlation with N balance in this group. Despite the marked difference in N balance, 3-methylhistidine excretion was increased but equal in the two nutritional groups, suggesting an increased rate of muscle protein breakdown in both groups, which appears not to be influenced by amino acid nutrition. It is concluded that N balance can be significantly improved in the immediate posttrauma period by provision of amino acids together with energy substrates. None of the biochemical variables measured, with the exception of plasma levels of essential amino acids, reflected these marked differences in N balance.

Adult↗

The effect of long-term arterial occlusion on energy metabolism of the human quadriceps muscle.

The effect of 1.5 to 2.5 h tourniquet ischemia on energy metabolism of the quadriceps muscle was studied using percutaneous needle biopsy technique in sixteen patients operated on for an inveterated knee injury. During occlusion there was a moderate decrease in ATP with an increase in ADP and AMP. This change resulted in a decreased energy charge potential. At the same time phosphorylcreatine (PC) decreased markedly while creatine (Cr) increased giving a constant total creatine (TCr). An accumulation of lactate during occlusion with values up to 80 mmol/kg d.m. (dry muscle) was seen. A 15% reduction in glycogen was calculated. After release of the tourniquet the active phosphate concentration and the energy charge potential returned to basal levels within 5 min and most of the metabolites in the glycolytic sequence were also normalized. Muscle lactate content was normal after 30 min of intact circulation. The results suggest that longterm tourniquet ischemia induces marked changes in energy metabolism in skeletal muscle, but that the changes are rapidly and completely reversible with restoration of blood flow.

Adenosine Diphosphate↗

Treatment of pilonidal sinus by radical excision and reconstruction by rotation flap surgery of Z-plasty technique.

Defects after excision of large pilonidal sinuses were reconstructed by either rotation skin flaps or a Z-plasty technique. Altogether, 16 patients were operated on, 10 with a rotation flap and 6 with a Z-plasty technique. All the patients except one underwent a radical operation. The patient not having a radical operation had a recurrence. Two cases in the Z-plasty groups acquired an infection in the distal part of the wound necessitating reoperation on the resultant sinus. The disability after this more extensive surgery was not more pronounced than after ordinary surgical procedures. For large recurrent pilonidal sinuses, radical excision and primary suturing of the wound using a rotation flap is recommended as the method of choice.

Adult↗

Activation of the kallikrein-kinin system in bullet wounding.

Anesthetized pigs were wounded in the thigh with a spherical missile at an impact velocity of 1500 m/sec. Arterial blood samples were taken before injury and at frequent intervals up to 12 hours after injury. Unbound (free) and total kallikrein (kallikrein + prekallikrein) were analyzed with a chromogenic substrate (S-2302, Kabi, Sweden) in which enzyme activity is determined spectrophotometrically by the development of a yellow colour. The results indicate an activation of the kallikrein-kinin system in bullet wounding, the significance of which remains to be determined.

Animals↗

The local hemodynamic effects of operation in a bloodless field.

Skeletal muscle blood flow and transport function were investigated in 25 patients operated on for a knee injury in a bloodless field. With a double-isotope-clearance technique, measurements were carried out in the operated leg immediately after re-establishment of blood flow, and 1-2 days postoperatively in both the operated and the non-operated leg. A significant increase in blood flow and transport function was registered immediately after release of the tourniquet. The initial maximal hyperemic flow and transport responses were inversely related to the duration of the occlusion. The peak of the blood flow response was more marked and somewhat earlier in the patients with a short duration of occlusion (less than or equal to 60 min) than in those with longer occlusions. 9 of 16 operated legs showed a maximal transport function 1-2 days postoperatively. Peripheral vascular resistance decreased after re-establishment of blood flow. The blood flow in the non-operated leg showed no changes after release of the tourniquet in the operated leg.

Adult↗

Electrolyte changes in muscle tissue and plasma in tourniquet-ischemia.

The effect of long-term tourniquet ischemia on electrolyte levels in muscle tissue and plasma during and after occlusion was investigated in man. Muscle tissue electrolytes were studied in nine patients using a percutaneous muscle biopsy technique. The estimation of the intra- and extracellular electrolyte content was based on the determination of the chloride space. In another similar group of patients (n=11) plasma electrolytes were investigated by taking blood samples from fine plastic catheters inserted into both femoral veins and one radial artery. Capillary blood flow was measured using the 133Xenon-clearance technique. During occlusion there were no significant changes in muscle tissue or plasma electrolytes. After release of the tourniquet an increase in plasma potassium of the operated leg and arterial plasma were observed. Maximal muscle blood flow and maximal potassium values occurred at the same time giving a pronounced potassium release from the operated leg. The osmol release from the occluded leg showed a maximum 1 min after tourniquet release. The total and intracellular content of potassium and sodium in the muscle tissue did not significantly alter after release of the occlusion. A moderate increase in extracellular water was found after tourniquet release.

Adult↗