[Vårdfacket's language school. Dialysis nurse].
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Biomedical subjects
Publications and source records attributed to J Larsson.
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Muscle energy metabolism was studied by chemical analysis of biopsy samples from: 1) trigger points in the trapezius muscle from 15 patients with primary fibromyalgia (PF), 2) nonpainful, anterior tibial muscle from 6 patients with PF, and 3) the trapezius muscle from 8 healthy controls. We found a decrease in the levels of adenosine triphosphate, adenosine diphosphate, and phosphoryl creatine, and an increase in the levels of adenosine monophosphate and creatine, in the trapezius muscles from the patients. These findings support the notion that the pain in patients with PF is of muscular origin.
Measuring skeletal muscle function may be a diagnostic aid to detect malnutrition. To evaluate this hypothesis 11 lean women were studied before and after 5 days of total starvation. Skeletal muscle function was assessed as hand grip strength and as adductor pollicis muscle function after electrical stimulation of the ulnar nerve. The muscle function variables were force of contraction at 5, 10, 20 and 50 Hz stimulation, relaxation rate and endurance. In addition some currently used anthropometric and biochemical nutritional indices were serially determined. Hand grip strength was decreased (p < 0.05) and the function of the adductor pollicis muscle was altered with a higher contraction force at 10 Hz (p < 0.01), a slower relaxation rate (p < 0.05) and a reduced endurance (p < 0.05). These changes were all within the normal ranges. Triceps skin fold and arm muscle circumference were not changed after a mean weight loss of 3.3 kg (p < 0.05). However blood glucose, insulin and triiodothyronine all decreased (p < 0.01) indicating a metabolic adaptation to starvation. Prealbumin (p < 0.05) and fibronectin (p < 0.01) were also lowered. In conclusion, skeletal muscle function was significantly altered after five days of total starvation. However, to identify short term nutritional depletion in clinical practice the changes in muscle function were too small to be diagnostically useful.
Carnitine is necessary for the transport of long-chain fatty acids across the mitochondrial membrane. Carnitine is derived from the diet and from endogenous synthesis from lysine and methionine. About 98% of the body's carnitine pool is located in skeletal muscle tissue. Skeletal muscle carnitine levels were determined in two groups of malnourished patients, eight patients with anorexia nervosa with a weight loss of 32.4% +/- 1.8 (mean +/- SEM) and six surgical patients with major gastrointestinal disorders and a weight loss of 15.2% +/- 2.7. Their hepatic and kidney functions were normal. On admission, the muscle carnitine levels were 16.9 +/- 4.0 mumol/g dry weight (mean +/- SD) for the surgical patients and 20.8 +/- 5.0 mumol/g dry weight for the anorexia nervosa patients, which corresponded to carnitine levels seen in healthy subjects. No statistical significance was found between the two groups. Total parenteral nutrition was given to the surgical patients for 2 weeks and to the anorexia nervosa patients for 3-5 weeks. No statistical difference in muscle carnitine levels was found in either group after nutritional support. These malnourished patients had no decreased muscle carnitine levels on admission and maintained them during several weeks of total parenteral nutrition.
Olfactory rosettes from trout (Salmo gairdneri) were found to metabolise (14C-ethyl)-phenacetin to 14CO2 in vitro. Based on wet weight, the rate of metabolism was lower than that in liver and gills. Based on protein content, the rate of metabolism was about equal to that in liver and gills. Addition of the cytochrome P-450 inhibitors metyrapone, 9-hydroxyellipticine and piperonyl butoxide significantly decreased the formation of 14CO2 from (14C-ethyl)-phenacetin in olfactory rosettes. Microautoradiography of rosettes incubated with (14C-ethyl)-phenacetin showed the presence of non-extractable metabolites in the sensory and indifferent epithelium. Addition of metyrapone decreased the binding of radioactivity in the epithelia considerably. When olfactory rosettes were incubated with (14C-dimethylamine)-aminopyrine, no formation of 14CO2 was observed. The results are concluded to indicate that cytochrome P-450 dependent enzyme activity is present in the epithelia of the trout olfactory rosette.
Seventy-seven muscle biopsies from 57 patients with primary fibromyalgia and 17 biopsies from 9 healthy controls were examined by routine histopathological and histochemical methods. All patients fulfilled strict diagnostic criteria. 42 biopsies from patients were deemed normal or borderline, while 35 showed discrete pathological changes (degeneration, regeneration, inflammatory infiltrates, ragged red fibres, and 'moth-eaten' fibres in muscles other than m. trapezius). Biopsies from controls were normal or borderline in 14 and showed mild focal abnormalites in 3 cases. 'Moth-eaten' fibres were found in 35 of 41 trapezius biopsies taken from patients and in 9 of 10 trapezius biopsies from controls. Ragged red fibres were found in 15 of 41 trapezius biopsies taken from patients. In the deltoid muscle, 'moth-eaten' fibres were found in 3 and ragged red fibres in 2 of 9 biopsies from patients. Frequency of type I and type II fibres and the area of muscle fibres were the same in patients as in controls. Capillary density was the same in both groups. These changes, although not sufficient to constitute a diagnostic test for PF, indicate that this condition has an organic basis.
Skeletal muscle function may be used to assess nutritional status. To approach this hypothesis nine malnourished surgical patients were studied at admission and after two weeks of preoperative total parenteral nutrition. The muscle function variables, force at 10 Hz stimulation (F10), relaxation rate (RR) and endurance (E) were determined. Energy metabolites were measured in muscle biopsies. At admission muscle function and content of energy-rich phosphates were normal, muscle glycogen was low and water was increased. After nutritional therapy, F10 and E were unchanged, RR was increased (p less than 0.05), glycogen was normalized, muscle water remained high while the nutritional markers prealbumin and skin test were markedly improved. In conclusion, skeletal muscle function and content of energy-rich phosphates were normal in semistarved malnourished patients. After nutritional therapy, RR was increased and this may prove useful in following the effect of nutritional repletion.
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The effect of two weeks of total parenteral nutrition (TPN) on energy-rich phosphates, muscle water, electrolytes and free amino acids in skeletal muscle were determined in ten malnourished patients with gastric carcinoma. The total adenine nucleotide pool, phosphocreatine, creatine and glycogen were decreased before TPN, and only glycogen returned to normal after TPN compared with controls. Total muscle water and the intramuscular concentrations of sodium and chloride were initially increased and were not influenced by TPN. The total non-essential amino acids in muscle were decreased by 9 per cent, mainly due to a 15 per cent decrease in glutamine. The concentrations of free amino acids in muscle were not affected by two weeks of TPN. This study demonstrates disturbances in energy, water and amino acid metabolism in skeletal muscle of malnourished patients with gastric carcinoma, and that two weeks of TPN could not normalize these changes, except in the case of glycogen. The reason for this might be enzyme abnormalities due to adaptation to energy or protein deficit. A longer period of refeeding might therefore be necessary to improve peripheral metabolism in these patients.
The concentrations of free amino acids in muscle and plasma were determined in nine female patients with severe anorexia nervosa before and after 3 to 5 weeks of total parenteral nutrition (TPN). The patients had lost 25 to 42% of their pre-morbid weight. During TPN their weight gain was around 2.5 kg/week. Initially total non-essential amino acids (NEAA) in muscle were decreased 30% compared to controls. The major part of this depletion was due to a 40% reduction in glutamine. After TPN the level of glutamine normalized. Alanine, being normal before TPN, decreased after TPN. Proline and several other non-essential amino acids in muscle were decreased before and after TPN. Total essential amino acids (EAA) in muscle were initially normal and were not significantly affected by TPN. Total NEAA in plasma were decreased at admission and normalized after TPN. Total EAA in plasma, however, were normal both before and after TPN. This study demonstrates that severely malnourished patients with anorexia nervosa have changes in amino acid patterns in both muscle and plasma. These changes were largely, though not completely, reversed after 3 to 5 weeks of TPN.
Nutritional assessment variables were measured weekly in 10 young women with severe anorexia nervosa during treatment with total parenteral nutrition (TPN) for a 5 week period. Before the start of treatment the patients had lost 25-53% of their habitual weight, triceps skin fold (TSF) and arm muscle circumference (AMC) measurements were below the 5th percentile and all were anergic in the delayed hypersensitivity (DH) response. Plasma protein levels were normal except in fibronectin and prealbumin where levels below the reference interval was found in five patients. During TPN the body weight increased most likely due to rehydration and increase in lean body mass. Significant increases were seen in body weight weekly, but in TSF and AMC only after 4 and 3 weeks respectively. TSF and AMC were still below or at the 5th percentile after 5 weeks of TPN. DH response as well as fibronectin and prealbumin levels normalised in all patients. Despite only partial recovery in body cell mass the clinical picture had changed markedly so that the patients now were amenable to psychotherapy and had an adequate intake of food orally, enabling further nutritional therapy to be completed without parenteral support.
The effect of up to 2.5 h circulatory occlusion on muscle pH and energy metabolism of the quadriceps muscle was studied in 13 patients operated on for an inveterate knee injury. Muscle samples were taken by the percutaneous needle biopsy technique at different times during the arterial occlusion and after restoration of circulation. Energy was provided by a complete utilization of phosphocreatine and by a low rate of glycolysis during 2 h of occlusion. The ATP level remained unchanged throughout the occlusion period. Muscle pH decreased from 7.0-7.1 to about 6.8 after 2 h occlusion. Muscle pH was essentially normalized within 20 min after restoration of the blood flow.
The metabolic effects of TPN containing high amounts of amino acids (18 gm N) was evaluated with respect to sulfur amino acid metabolism and protein breakdown in nine severely burned patients. The results were compared to corresponding data from burned patients receiving more moderate amounts of amino acids (9.2 gm N) or isocaloric amounts of carbohydrate and fat. Significantly increased urinary excretion and intracellular muscle tissue concentrations of methionine were found in patients receiving the concentrated amino acid solution, probably reflecting a combined effect of the injury and an increased load of the compound. These patients also showed a reduced oxidation of sulfur amino acids to inorganic sulfate, which may reflect an increased protein synthesis during treatment. A significantly decreased urinary excretion of 3-methyl-histidine and mercaptolactate was found in patients receiving the concentrated amino acid solution, probably reflecting a decreased breakdown of body protein. The findings favor the hypothesis of an anabolic effect of the new amino acid solution in burned patients during the early catabolic phase, but also emphasize the importance of monitoring the amounts of amino acids, e.g., methionine, given.
In recent years, reports have shown positive effects of hyperbaric oxygen (HBO) treatment in posttraumatic circulatory insufficiency of the extremities. A tourniquet model for temporary ischemia was used to examine such treatment in rats. The circulation of the rat hindlimb was interrupted for 3 hours, while the contralateral uninjured leg served as control. There was a significant (p less than 0.001) postischemic edema in the tourniquet leg up to 48 hours after restoration of circulation. One group of animals received treatment with hyperbaric oxygen at 2.5 atmospheres absolute (ATA) for 45 minutes after release of the tourniquet. This significantly reduced (p less than 0.001) the postischemic edema, and the reduction persisted for 40 hours after the last treatment. It is concluded that hyperbaric oxygen reduces postischemic edema. Hyperbaric oxygen may therefore be useful as an adjuvant in the treatment of acute ischemic conditions when surgical repair alone fails or is not sufficient to reverse the ischemic process.
Severe anorexia nervosa in which psychiatric treatment has failed is a life-threatening condition since the degree of emaciation can be profound. Nine young women with a weight loss of 25-50% of their habitual weights were given total parenteral nutrition (TPN) over 3-8 weeks through a tunneled central venous silicone catheter. They initially received a mean of 55 kcal/kg body weight/24 hours increasing to 65-70 kcal/kg body weight during the first week. The initial bradycardia and hypotension were normalized and body weight increased with a mean of 2.5 kg/week. All patients showed a general somato-psychic improvement after two weeks of TPN. The electrolyte disturbances seen at the beginning were normalized during the first weeks of treatment and the previously reported life-threatening electrolyte disturbances and dehydration in connection with TPN treatment were not seen. The only adverse effect registered was a rise in liver enzymes in two patients who were given greater than 80 kcal/kg and day. With a reduction of the caloric supply these changes normalized, and TPN could be continued. After 3-8 weeks the oral intake had normalized and TPN was discontinued. This study confirms that TPN can be used successfully and with minimal risk in severe anorexia nervosa until the patients have normalized their oral intake.
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To assess the viability of traumatized skeletal muscle, only clinical criteria have been available. Discolouration of the muscle following the trauma is one such criterion, and was earlier found to be associated with impaired circulation and severe metabolic disorders. The present study, continuing investigations into the pathophysiologic basis for the clinical criteria, was concerned with local electrolyte and water changes in skeletal muscle subjected to high-energy trauma. Biopsies were made from discoloured traumatized muscle and from adjacent normally coloured muscle 1, 5 and 10 hours after the trauma. Discoloured muscle showed little change in water content, but elevated values of Na+ and Cl- and very low K+ and Mg++ values. The changes progressed with time and showed no tendency to reversibility. The adjacent normally coloured muscle did not differ in electrolyte or water content from nontraumatized muscle. The magnitude of the electrolyte changes in discoloured muscle implied very severe cellular damage. This could have been due to mechanical disruption caused by the pressure wave, or to inability of the muscle cell to maintain a normal transmembrane potential, or to both factors. The findings correlate well with results of earlier metabolic and circulatory studies indicating that discolouration of traumatized skeletal muscle signifies nonviability.
Two different methods for estimating muscle function were compared; hand grip strength (HGS) and adductor pollicis muscle function after electrical stimulation of the ulnar nerve. Fifty-two 'normal' subjects, who were divided into four groups, according to sex and age, were investigated. Technical modifications of the latter method are presented for the measurement of human skeletal muscle function, independent of the motivation of the subject. Maximal voluntary force, as measured with a hand dynamometer, was higher in males than in females. Young males were stronger than males over 50 years old, and young females were stronger than old women. The statistical analysis of the muscle function variables after electrical stimulation showed that young females developed relatively more force at low stimulating frequencies than females over 50 years old. Females had a significantly longer contraction time to tetany compared to males. The relaxation rate after tetanic stimulation was independent of sex and age. Endurance was reduced in old males compared to females in the same age-group and to young males.