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Biomedical subjects

G Einarsson

Publications and source records attributed to G Einarsson.

13 recordsLinked to original sources

Guidance levels in the Nordic countries: a preliminary report for selected interventional procedures.

The Nordic radiation protection authorities have already published recommended guidance levels for patient doses for six conventional radiological examinations. Over the past two years a similar protocol has been in progress for three interventional procedures. Measurements have been performed in 22 different hospitals in the Nordic countries on patients in the weight range 40-100 kg. The selected procedures are percutaneous transluminal coronary angioplasty (PTCA), percutaneous transluminal angioplasty (PTA) and endoscopic retrograde cholangio- and pancreatio-graphy (ERCP). A total of 281 PTCA procedures, 304 PTA procedures and 147 ERCP procedures are included in the study. The results from this survey are presented as a first attempt to set guidance levels.

Angioplasty, Balloon↗

A Nordic survey of patient doses in diagnostic radiology.

The aim of this study was to test the applicability of the guidance levels for patient doses cooperatively set by the radiation protection authorities in the five Nordic countries. The kerma-area product (KAP) for five conventional radiological examination types was obtained from several hospitals in each of the Nordic countries. The number of radiographic images and fluoroscopy time were also registered, and the mean values for each examination type and hospital were established based on a representative number of patients (40-100 kg). The results indicate that the situation is very similar in the five Nordic countries, even though some differences were identified. Most of the hospitals demonstrated lower doses than the proposed guidance levels for chest, probably explained by use of faster film/screen combinations during the past decade. An increased use of fluoroscopy for positioning was observed for radiographic examinations of lumbar spine and urography. Large variations in patient doses were found for barium enema depending on the use of fluorospot or 100-mm camera vs full-format film, the range in fluoroscopy times, dose rate, and field size. The guidance levels for lumbar spine (10 Gy x cm2), pelvis (4 Gy x cm2), urography (20 Gy x cm2), and barium enema (50 Gy x cm2) seem to reflect the present quality of X-ray equipment and examination techniques in the Nordic countries. The guidance levels for chest (1 Gy x cm2) should be lowered to 0.6 Gy x cm2.

Barium Sulfate↗

A comparison of symptoms between Swedish and American post-polio individuals and assessment of lower limb strength--a four-year cohort study.

A cohort study with initial and 4-year follow-up evaluations was performed in 78 post-polio volunteers aged 34-65 years at the time of enrolment in the study, which was made to compare post-polio individuals living in Sweden and the United States, to determine whether lower limb musculature becomes weaker over time, and to determine whether individuals with complaints of post-polio syndrome, new weakness, fatigue, walking or stair climbing difficulty were weaker or lost more strength over a 4-year interval than those individuals without such complaints. Dynametrically-measured knee extensor and flexor strength and questionnaire data were obtained initially and 4 years later. The two cohorts were fairly similar, though they differed in weight gain. The Americans gained significantly (p < 0.05) more weight than the Swedish subjects. Both groups lost significant (p < 0.05) knee extensor strength (approximately 8%), but the loss was not significantly (p < 0.05) different between the groups. Knee flexor strength did not change significantly (p < 0.05) over time. Subjects acknowledging new strength loss were not significantly (p < 0.05) weaker than those denying strength loss; however, they lost significantly (p < 0.05) more isometric knee extensor strength than the other individuals. Subjects acknowledging new fatigue, walking or stair climbing difficulty were significantly (p < 0.05) weaker in both muscle groups than those without such complaints. Subjects acknowledging post-polio syndrome were significantly (p < 0.05) weaker than those denying this symptom, but the amount of loss of strength over time was not significantly (p < 0.05) different. We conclude that the two cohorts were quite similar. Knee extensor strength decreased during the study interval. Individuals acknowledging post-polio syndrome had weaker knee extensor musculature. Subjects with new fatigue, walking difficulty, or stair climbing difficulty were weaker in both the knee extensors and the knee flexors than the other subjects. Subjects reporting new muscle weakness also had a greater decline in isometric knee extensor strength during the study interval than those without such complaint.

Adult↗

Muscle adaptation and disability in late poliomyelitis.

Persons who suffered poliomyelitis 3 or more decades ago now report functional decline and symptoms designated as "post-polio syndrome". The objects of this investigation were to identify subjects fulfilling the criteria of this syndrome, to describe their motor impairment and resulting disabilities/handicaps, to study the adaptive changes in the muscle structure and effects of a resistance exercise program. Forty-one late-polio subjects, 40-65 years old, volunteered for the studies of motor impairment, subgroups of those volunteered to further studies of long-term and short-term adaptations. Seventy-five per cent of the subjects met the criteria for the post-polio syndrome. Complete manual muscle tests and dynamometer measurements of knee muscle strength revealed severe motor impairment predominantly in the lower extremities, the strength of the latter correlating to the degree of mobility handicap. In biopsies from the vastus lateralis muscle, type grouping was frequent. Half of the subjects demonstrated over 70% occurrence of type I fibers with negative significant correlation to strength in the female subjects. Cross-section areas of muscle fibers were on average twice the normal, with negative significant correlation to strength values in male subjects. Muscle enzymatic activity values showed large individual variations; oxidative activities (citrate synthase) were low or very low, while average glycolytic activities were nearly normal. Macro EMG and single-fiber EMG measurements in the vastus lateralis muscle demonstrated large macro motor unit potentials and increased fiber density. Neuromuscular transmission was disturbed as identified by jitter and blockings in most subjects regardless of the occurrence of new muscular symptoms. A statistically significant increase in strength (25-30%) resulted from a 6 weeks' heavy resistance exercise program, utilizing a dynamometer, without any obvious side-effects. Strength improvement was maintained for 6-12 months after training while fatigue index increased. A substantial impact on intermediate (secondary or instrumental) ADL, most severely affecting the quality of mobility, was generally found, while little effect was found on primary ADL as revealed by the Katz' ADL index, the Functional Status Questionnaire and the WHO ICIDH Classification of Handicap. The impaired motor function confirms findings in earlier studies. It also corresponds with the locomotor disabilities and handicaps. The negative correlation of strength to cross-section fiber area might result from excessive use of remaining fibers leading to a prominent hypertrophy in the weakest subjects. Enzyme activities probably reflect the pattern of everyday activities with little demands on endurance.(ABSTRACT TRUNCATED AT 400 WORDS)

Activities of Daily Living↗

Muscle conditioning in late poliomyelitis.

To study the adaptability of postpolio muscles, 12 subjects (mean age 54 years) participated in a high-intensity resistance exercise program. Seventy-five percent met the criteria for postpolio syndrome. Isometric and isokinetic strength and muscle endurance were measured. Polio-affected muscles were identified in muscle biopsies. The biopsies were also used for measurements of enzymatic activities and for histochemical and histopathologic analyses. Pretraining strength values were less than half those of healthy controls, mean fiber areas were twice those of healthy controls, and oxidative enzyme activity was low. After training, a significant increase in isometric (mean 29%) and isokinetic (mean 24%) strength was observed and maintained for some time. This demonstrates remaining adaptability in muscles already compensated from long-standing polio.

Adaptation, Physiological↗

Electromyographic and morphological functional compensation in late poliomyelitis.

Patients with prior poliomyelitis may experience muscle function deterioration decades after onset of disease. The present study is aimed at describing electromyographic and morphometric evidence of muscular compensation and of on-going muscular instability. Ten subjects 42-62 years of age with onset of polio 25-52 years earlier were studied with macro EMG, single-fiber EMG (SFEMG), muscle strength measurement, and morphometrical analysis of muscle biopsies from the vastus lateralis muscle. SFEMG revealed increased fiber density (FD) and large macro-MUP potentials indicating pronounced reinnervation as compensation to loss of motor neurons. From electrophysiological data of motor unit size, morphometric measures of fiber size, and muscle strength data, the minimal degree of motor neuron loss was estimated to be greater than 70%.

Adult↗

Disability and handicap in late poliomyelitis.

The impact of long-standing polio sequelae in terms of disability and handicap was studied in 41 patients (17 men and 24 women, mean age 54 years). Twenty-nine (71%) of these met the criteria for post-polio syndrome. The Katz' ADL index, the Functional Status Questionnaire (FSQ), selected questions concerning social needs and support and the WHO ICIDH-Classification of handicaps were used. A substantial impact on intermediate (secondary or instrumental) ADL was a consistent finding, most severely affecting the quality of mobility. This emphasizes needs for individual rehabilitation services including transportation, walking and domestic aids.

Activities of Daily Living↗

Muscle adaptive changes in post-polio subjects.

Nineteen post-polio subjects (9 men and 10 women) aged 41-65 years were studied by means of muscle strength measurements (Cybex) of knee extension and muscle biopsies of the vastus lateralis for morphometric, histopathological and enzymatic analyses. Data from a reference group of 10 male subjects, age 42-51 years, are also given. Fourteen of the post-polio subjects had experienced a post-polio syndrome-like drop in function. All had had polio at least 25 years earlier. In nine of the 19 subjects, type I fibers accounted for more than 70% of the total. There was a significant negative correlation between muscle strength and the percentage of type I fibers in women. Large cross-section areas of muscle fibers were found, with an average mean fiber area of 8 microns 2 X 10(3). It is assumed that the large muscle fiber areas are due to an extreme use of the remaining muscle fibers in post-polio subjects with low muscle strength. There were significant negative correlations between muscle strength values and mean fiber area in men. Most subjects had single atrophic fibers; groups of atrophic fibers were less common. Internal nuclei and splitting were seen in about half of the subjects. The activity of citrate synthase was low, but normal for glycolytic enzymes.

Adult↗

Muscle morphology with special reference to muscle strength in post-polio subjects.

The main histopathologic finding is large grouping of type I and type II fibers. Subjects with low muscle strength had a large number of type I fibers. Large fibers were found especially in men with low muscle strength. The oxidative enzymatic activity was reduced. The findings suggest a compensatory process, with an increased number of type I fibers in subjects, a large reduction in muscle strength, and also an increase in the fiber size. There is a sex difference in the fiber hypertrophy.

Adult↗

Penile replantation.

A case of penile amputation and replantation is presented. Partial amputation may be repaired without microsurgical technique with good results. For complete amputation, specific microneurovascular repair is recommended.

Amputation, Traumatic↗