Treatment of the Guillain-Barré syndrome by plasmapheresis.

Treatment by plasmapheresis was performed in eight adult patients with the Guillain-Barré syndrome. One patient with a chronic relapsing form underwent four separate courses of plasmapheresis and her condition improved rapidly each time. Of seven patients with acute Guillain-Barré syndrome, the condition of three improved markedly, in one partially, and in three it did not improve in association with treatment. There were no apparent differences concerning clinical and neurophysiologic parameters between those whose conditions improved and those whose conditions did not.

Retrospective evaluation of cervical smears in women harbouring biopsy proven SIL.

Detection and evaluation of cervical pre-neoplasia is the purpose of cervical cytologic screening in the prevention of death from cervical carcinoma. This investigation is an attempt to evaluate previously taken cervical smears in women harbouring a biopsy proven squamous intraepithelial lesion (SIL). All cervical smears sampled during 4 years prior to biopsy as well as some of the smears during a 5 year follow-up were re-examined for 208 women who in a defined geographical area, the County of Gävleborg, in 1988 had a biopsy proven squamous intraepithelial lesion (SIL). The present study shows that a patient with a LSIL in the Pap smear is at high risk of harbouring or developing cervical squamous intraepithelial neoplasia.

Evaluation of a dynamometer for measurement of isometric and isokinetic torques.

A modified version of the original Cybex II dynamometer with a temperature compensated strain gauge transducer has been evaluated. It was found that the calibration constant was dependent of the vertical load of the device. The ratio (k) between the applied and the recorded torque is angle independent during extension and k is equal to 1.18 and during flexion k is angle dependent and can be expressed as k = -.0008 theta + 1.208, where theta is the angle of flexion.

Isometric muscle strength and endurance after knee arthroplasty with the modular knee in patients with osteoarthrosis and rheumatoid arthritis.

Maximum isometric muscle strength and endurance were used in an investigation of knee extension and knee flexion in patients with rheumatoid arthritis (RA) and osteoarthrosis (OA) with such severe changes of the joint that arthroplasty with the Modular prosthesis was performed. The measurements were done preoperatively and 3, 12, 24 and 36 months postoperatively. Muscle strength preoperatively was very weak compared with that of a group of healthy persons. The muscle strength 3 months postoperatively remained unchanged, which could mean a very slight trauma from the operation, very good pain relief and efficient physiotherapy. During the first 2 years the maximum isometric muscle strength was significantly increased both in patients with RA and in those with OA. Thereafter there was no increase in the RA patients, whereas in women with OA there was an improvement up to 3 years postoperatively. The improvement in the flexion strength was greater than that of the extension strength, thus indicating the importance of postoperative training of extension strength. Isometric muscle strength measurements show that there is an equalization between the non-diseased knee and the one operated with the Modular knee.

Isometric strength and endurance in patients with severe rheumatoid arthritis or osteoarthrosis in the knee joints. A comparative study in healthy men and women.

Maximum isometric muscle strength on extension and flexion of the knee joints and endurance on extension has been studied in patients with rheumatoid arthritis (RA) and osteoarthrosis (OA), with such severe degeneration of the knees that arthroplasty was indicated. This material was compared with a group of healthy volunteers. The reduction in muscle strength was most pronounced in the RA group, which had 30-45% of the strength of the healthy volunteers. In the OA group the strength, similarly compared, was 55-70%. The difference is explained by the effect of the rheumatic disease on the muscles. The results indicate that in therapeutic measures due to trauma or in joint surgery, methods that contribute to a further decrease in muscle strength, e.g. immobilization with casts, bandages, or traction treatment, should be avoided.

Isokinetic knee extension strength and pain before and after correction of recurrent patellar dislocation.

The maximal isokinetic knee extension strength was measured in 20 patients before and after surgical correction of recurrent dislocations of the patella and the pain evoked during the recordings was rated. The preoperative muscle strength was significantly higher and pain was less severe than in a previously studied group of patients with chondromalacia or patellofemoral osteoarthrosis. Twenty months after patella realignment by a new surgical procedure including an extensive lateral release and anteromedial displacement of the tibial tuberosity by an oblique osteotomy through the anterior crest of the tibia, a significant decrease of patellofemoral pain and a slight increase of muscle strength was noted.

Isokinetic knee extension strength and pain before and after advancement osteotomy of the tibial tuberosity.

In 30 patients with patellofemoral chondromalacia and osteoarthrosis the maximal isokinetic knee extension strength was measured. The pain evoked during the recordings was rated on a nine-grade scale. The peak extension torques were markedly lower than in the non-diseased knee and in a reference group of healthy volunteers. Twenty months after advancement of the tibial tuberosity, the muscle strength was significantly increased and pain significantly alleviated, well parallelling the clinical improvement. Intra-articular anaesthesia almost instantaneously increased the knee extension torque considerably, although knee pain was unchanged.

The validity of four bicycle ergometer tests.

The aim of this study was to compare the validity of four physical work and performance tests on bicycle ergometers commonly used in Sweden. The following four tests were compared: a) a work test of submaximal character designed for estimation of the maximal oxygen uptake of the individual (Vo2 max); b) a work test of maximal character designed for estimation of the highest work load an individual can sustain for 6 minutes (Wmax6min); c) the Cycling Strength and Endurance Test (CSET)-a performance test of maximal character consisting of a series of intermittently determined terminal thresholds; and d) a flexible work test of maximal character, the Individually Adapted Work Test (the IA-test): by a feedback mechanism the highest work load an individual can be expected to sustain for 4 minutes is determined. Criteria were cross-country runs (altogether 4) arranged a short time before and after the tests on the bicycle ergometer. Subjects were military conscripts, aged 17-25. When comparisons were made between the best prediction variable of each test, no significant differences were obtained. The size of the validity coefficients was .55-.70. However, the maximal work tests showed the highest validity coefficients. The investigation indicates that, when a work test is to be chosen, the problem, the practical conditions and the resources available should guide this choice.

Isometric and isokinetic muscle strength, anthropometry and physical activity in 8 and 13 year old Swedish children.

Isometric muscle strength of the hand-grip and of trunk flexion and extension, and isokinetic torque of elbow and knee flexion and knee extension were assessed in a random sample of 8 and 13 year old Swedish children. The results were compared with respect to sex and age in absolute terms and relative to weight, height2 and estimates of lean body mass and cross-sectional muscle area. Daily physical activity was also estimated. The muscle strength variables were in general found to be very similar in the 8 year old boys and girls. In the 13 year old group the boys were generally stronger than the girls, in both absolute and relative terms, except for similar torque values during knee extension. The absolute and relative muscle strength and torque values were higher in the older than in the younger children, with the exception of trunk strength per unit of body weight and of lean body mass, which were similar in boys of both ages and significantly lower in the older than in the younger girls. No significant correlation was found between the estimates of physical activity and isometric and isokinetic muscle strength and torque.

Resection arthroplasty for repair of complete acromioclavicular separations.

Oblique resection of the lateral end of the clavicle and transfer of the coracoacromial ligament into the medullary cavity of the clavicle according to Weaver and Dunn had been performed in 12 fresh and 5 old type 3 separations of the AC-joint. At follow-up 1--5 years after the operation all patients had stable and painless shoulders. Heavy work and competitive sports had been resumed. The functional and cosmetic results were excellent. Stress radiographs showed good alignment and stability. The muscle strength, recorded with an isokinetic technique, was normal in the shoulder and slightly lowered in the elbow.

The effect of circulatory occlusion on isometric exercise capacity and energy metabolism of the quadriceps muscle in man.

Occlusion of the circulation to the quadriceps muscle for 20 min resulted in decreases in the muscle ATP and phosphorylcreatine (PC) contents of 1 and 32 per cent, respectively, and increases in ADP and AMP of 7 and 37 per cent. Decrease in PC was statistically significant after 4 min of occlusion, suggesting that the local intramuscular oxygen store was sufficiently depleted at this time as to be limiting to normal mitochondrial function. Pyruvate and lactate concentrations in muscle and the lactate to pyruvate ratio were significantly increased after 15 min of occlusion but not before. The calculated local oxygen store in the muscle was 2.0 mmol O2 - (kg dry muscle)-1. Local oxygen store depletion after 4 and 10 min of occlusion was estimated to be 40-50 and 90-100 per cent complete. Increasing time of pre-exercise occlusion resulted in decreased isometric endurance capacity. The observed decreases in endurance, however, were far greater than could be accounted for by any parallel decrease in the local muscle energy stores.

The time course of phosphorylcreatine resynthesis during recovery of the quadriceps muscle in man.

The time course of phosphorylcreatine (PC) resynthesis in the human m. quadriceps femoris was studied during recovery from exhaustive dynamic exercise and from isometric contraction sustained to fatigue. The immediate postexercise muscle PC content after either form of exercise was 15-16% of the resting muscle content. The time course of PC resynthesis during recovery was biphasic exhibiting a fast and slow recovery component. The half-time for the fast component was 21-22s but this accounted for a smaller fraction of the total PC restored during recovery from the isometric contraction than after the dynamic exercise. The half-time for the slow component was in each case more than 170 s. After 2 and 4 min recovery the total amount of PC resynthesized after the isometric exercise were significantly lower than from the dynamic exercise. Occlusion of the circulation of the quadriceps completely abolished the resynthesis of PC. Restoration of resynthesis occurred only after release of occlusion.

Effect of temperature on muscle energy metabolism and endurance during successive isometric contractions, sustained to fatigue, of the quadriceps muscle in man.

1. The effects of altered tissue temperature on muscle metabolism during successive isometric contractions, sustained to fatigue, have been studied in the quadriceps muscle of man by combining biochemical analyses of metabolites in needle biopsy samples with measurements of endurance time with a force of 2/3 maximum voluntary contraction. Fatigue and recovery were observed repeatedly in a series of seven contractions at intervals of 20 sec, following immersion of the test leg in water at 12, 26 or 44 degrees C for 45 min. Muscle temperatures corresponding to these water temperatures were 22.5, 32.6 and 38.6 degrees C respectively.2. Increased levels of several glycolytic intermediates at rest in the heated muscle suggested an increased rate of glycolysis. ATP and phosphoryl creatine were lower at the end of the first contraction and the calculated rate of ATP utilization (including the contribution from anaerobic glycolysis) was highest in the heated nuscle.3. Significantly shorter endurance times were found for the heated muscle. These could not be attributed to depletion of local energy resources in muscle. Fatigue may be due to a reduction in the rate of regeneration of ATP from anaerobic glycolysis below that needed to maintain the contraction force. Lower values for the ratio of fructose 1,6-diphosphate: fructose 6-phosphate at the end of contractions, particularly at the highest temperature, are compatible with the hypothesis that there is partial inhibition of the rate controlling enzyme phosphofructokinase, possibly due to the accumulation of hydrogen ions in muscle.

The quadriceps femoris muscle in 20-70-year-old subjects: relationship between knee extension torque, electrophysiological parameters, and muscle fiber characteristics.

Comparisons have been made between torque (isometric and isokinetic), electrophysiological (SFEMG, Macro EMG), and muscle fiber characteristics in the vastus lateralis muscle of both legs in healthy subjects aged between 20 and 70 years. Torque was greater in males and decreased with age in both sexes. Multifactorial analysis showed a positive correlation between torque, body surface area, and mean fiber area. These variables explained only about 30-40% of the torque changes. The electrophysiological parameters (Marco EMG amplitudes and fiber density) revealed evidence of reinnervation, indicating preceeding denervation and therefore loss of motor units. It was concluded that this fall out of motor units also contributes to the reduction in torque, when compensatory reinnervation begins to fall. Other factors, such as reduction in muscle fiber contractility, metabolic factors, and central factors, may also play a role in age-related reduction in torque.