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Biomedical subjects

K G Henriksson

Publications and source records attributed to K G Henriksson.

At least 55 records · Page 3Linked to original sources

X-linked myotubular myopathy: clinical and pathological findings in a family.

A five-generation family with recessively inherited X-linked myotubular myopathy was investigated. Two of the affected boys, who were siblings and were verified by muscle biopsy to have the disease, died 3 days and 3 months, respectively, after birth. They showed marked hypotonus from birth, general muscle weakness and asphyxia. Three other boys, who were probably affected by the disease, had severe asphyxia and died shortly after birth. In three of the five cases there was polyhydramnios. The muscle biopsies of the two siblings revealed predominance of small fibres with central nuclei and accumulation of mitochondria in the central parts of the fibres. In one of the boys mainly the type 1 fibres were hypotrophic. The postmortem examination revealed variation in the involvement of different muscles, the anterior tibial muscle being the most severely affected. Intrafusal muscle fibres and myocardium were apparently unaffected. There was no involvement of the spinal cord. The clinical examination of two obligate carriers in the family revealed no muscle weakness but the muscle biopsy showed pathological changes including greatly increased variability of fibre size, and many fibres with central nuclei. The findings indicate that muscle biopsy is of value in genetic counselling to detect carriers although the observed changes were unspecific.

Adolescent↗

The muscle in fibromyalgia--a review of Swedish studies.

In Sweden, several studies have been performed in patients with fibromyalgia to study muscle morphology, chemistry and physiology in order to understand the origin of the most prominent symptoms in fibromyalgia: muscle pain, muscle fatigue and muscle stiffness. These studies have shown changes indicating disturbed microcirculation, mitochondrial damage and a reduced content of high energy phosphates. Thus, there may be an energy deficiency state in the resting painful muscle in fibromyalgia. Pain analysis has supported the idea that there is a nociceptive origin of the pain. Our hypothesis is that any condition that could lead to constant muscle hypoxia, e.g., through establishment of abnormal motor patterns, might be a possible cause of fibromyalgic pain.

Adenosine Triphosphate↗

Muscle pain in neuromuscular disorders and primary fibromyalgia.

Muscle fiber degeneration and regeneration, inflammation in the intramuscular connective tissue and hypoxia in resting muscle are not necessarily associated with pain. However, when sustained or dynamic muscle contractions are performed in an ischaemic muscle, severe pain develops. In the chronic muscle pain syndrome called fibromyalgia (or fibrositis) the most likely cause of the pain is a combination of muscle tension and muscle hypoxia. This conclusion is supported by the finding of a pathological distribution of tissue oxygen pressure in painful muscles and a subjective feeling of muscle tension and muscle stiffness in the majority of patients. A decrease of high energy phosphates is found in biopsies from painful muscle. The most characteristic morphological finding is the so-called ragged red fiber, a finding that can be seen in mitochondrial disorders. The morphological and chemical findings are possibly a consequence of a long standing hypoxia. The possibility that sympathetic nerve activity is important for the development of chronic muscle pain is discussed.

Fibromyalgia↗

Isometric muscle force and anthropometric values in normal children aged between 3.5 and 15 years.

Isometric muscle force was measured in 217 normal children aged 3.5-15 years. The standard error of a single determination made by the same observer was ca. 9% of the muscle force. When two measurements were made by different observers the standard error of the difference was estimated at ca. 17%. Reference values for isometric force are given for boys and girls separately. With regard to 7 of the 10 muscle groups tested the force was significantly greater in boys than in girls as early as at ca. 10 years of age. Age and weight were the most important predictors of muscle force.

Adolescent↗

Muscle pain in neuromuscular disorders and primary fibromyalgia.

Muscle fibre degeneration and regeneration, inflammation in intramuscular connective tissue and hypoxia in resting muscle are not necessarily associated with pain. However, when sustained or dynamic muscle contractions are performed in an ischaemic muscle, severe pain develops. In the chronic muscle pain syndrome called fibromyalgia (or fibrositis) the most likely cause of the pain is a combination of muscle tension and muscle hypoxia. This conclusion is supported by the finding of a pathological distribution of tissue oxygen tension in painful muscles and a subjective feeling of muscle tension and muscle stiffness in the majority of patients. A decrease in high energy phosphates is found in biopsies from painful muscle. The most characteristic morphological finding is the so called ragged red fibre, which is a finding that can been seen in mitochondrial disorders. The morphological and chemical findings are possibly a consequence of a long standing hypoxia. The possibility that activity in muscle sympathetic nerves is important for the development of chronic muscle pain is discussed.

Energy Metabolism↗

The impact of time after portacaval shunt in the rat on behavior, brain serotonin, and brain and muscle histology.

We investigated open field behavior, cellular fluorescence of brain serotonin and serotonin metabolism in different regions of the central nervous system (CNS), and brain and muscle histology in rats 3 weeks or 6 months after surgical end-to-side portacaval shunt (PCS). The results revealed a similar disturbance of the CNS serotonin at 3 weeks and 6 months after PCS in the rat. Progressive neurohistological changes were present between 3 weeks and 6 months after PCS. The open field behavioral impairment appeared, however, to diminish with time. There was no evidence from muscle biopsies that lesions in the muscles or in the peripheral nerves contributed to the motor disturbance.

5-Hydroxytryptophan↗

Muscle function and morphology in myotonic dystrophy.

Patients with myotonic dystrophy classified clinically into function groups were studied. Muscle strength for knee extension and flexion was, with few exceptions, moderately or markedly reduced with successively more severe clinical disability. The reduction in maximal walking speed showed a similar tendency. There was a large percentage of both type I and in relation to normal findings of type II C fibers in biopsies from most patients. The fiber area varied greatly even in the patients in the best function groups, some of whom had large type II fibers. The most common-histopathological changes, found in all function groups, were fiber atrophy with small angular fibers, internal nuclei, splitting, fibrosis and moth-eaten fibers. A high percentage of type I fibers can already be seen in patients with practically no other morphological changes and without significant functional deterioration.

Adult↗

Skeletal muscle characteristics in children 9-15 years old: force, relaxation rate and contraction time.

Relaxation rate (RR), half contraction time to tetanus (CTT1/2) and force-frequency curves were investigated in 77 children, aged 9-15 years, using supramaximal stimulation of the ulnar nerve and recording from the adductor pollicis muscle. No sex differences were found in these variables. The RR was independent of age and similar to that in adults. The CTT1/2 was least at the age of 15. The only age-dependent parameter in the force-frequency curves was the relative force developed at a stimulus frequency of 10 Hz, which increased with increasing age. A fatiguability test was performed in 25 children. Reference values for the different parameters are given.

Adolescent↗

Selenium and vitamin E treatment of Duchenne muscular dystrophy: no effect on muscle function.

16 boys with Duchenne muscular dystrophy (DMD) were treated with sodium selenite and vitamin E for one year. One group of patients (10 boys) was examined using a battery of tests to assess muscular strength and function and cardiopulmonary function, and by CT scanning of 2 muscle groups over the 4 years prior to treatment. Six boys with DMD entered the study when the treatment was begun. Tests of muscular force and function, cardiopulmonary tests and CT-scanning were performed at the onset of treatment, and after 6 and 12 months. No beneficial effect on either muscular force or function was found during the treatment period. It is concluded that selenium and vitamin E in high doses do not improve muscle function in DMD.

Adolescent↗

Skeletal muscle function in primary fibromyalgia. Effect of regional sympathetic blockade with guanethidine.

Muscle fatigue is the most disabling symptom in primary fibromyalgia (PF), which in addition is characterized by generalised pain and muscle stiffness. In order to assess whether the fatigue is of central and/or peripheral origin, skeletal muscle function was studied by measuring maximum voluntary hand grip strength, and by measuring various contraction characteristics in the adductor pollicis muscle after electrical stimulation of the ulnar nerve. The PF-patients were also studied after a regional sympathetic blockade of the forearm with guanethidine. A lower hand grip strength was found in the PF-patients compared to the controls, before as well as during the sympathetic blockade. The developed force, measured during electrical stimulation, did not differ between patients and controls. A lower muscle relaxation rate was found in the PF-patients. The relaxation rate increased in the PF-patients during the sympathetic blockade. The results indicate both a central and a peripheral cause of muscle dysfunction. Activity in the muscle sympathetic system may be one link in the chain of events that leads to muscular symptoms in PF.

Action Potentials↗

Skeletal muscle contraction characteristics in vivo in malignant hyperthermia susceptible subjects.

Ten malignant hyperthermia susceptible (MHS) subjects were investigated, all of them positive in in vitro tests. As a control group 12 healthy subjects were investigated. The investigation was done in a blind fashion during strictly standardized conditions. Electromechanical delay of contraction and half contraction time to tetanus were faster (P less than 0.05) while half relaxation time was shorter in the MHS subjects (P less than 0.05). Skin and intramuscular temperature were significantly higher in the MHS subjects (P less than 0.05). This indicates that MHS subjects differ in various skeletal muscle characteristics during "normal" conditions. Further studies to define the temperature level at which the test of muscle function is most discriminating are needed before it can be used for diagnostic purposes.

Adolescent↗

Effects of hyperbaric oxygen treatment in post-ischemic muscle. A quantitative morphological study.

In the post-ischemic muscle, hyperbaric oxygen (HBO) treatments have been shown to reduce post-ischemic edema and enhance aerobic metabolism. In the present paper histological, histochemical and ultrastructural methods were used to study the influences of HBO treatment on the morphology of post-ischemic skeletal muscle. The changes were also quantified using morphometry. The circulation of the rat hindlimb was interrupted for 3 hours and muscle biopsies were taken 5 and 12 hours post-ischemia. Light microscopy showed signs of ischemic changes in the muscle. Morphometrically, the area with activity of the muscle enzyme phosphorylase was greatly reduced post-ischemia. HBO treatment at 2.5 atmospheres of absolute pressure (ATA) for 45 min significantly increased muscle cross sectional area with a positive phosphorylase reaction 5 hours post-ischemia. Three HBO treatments were necessary to maintain this effect, 12 hours post-ischemia. Ultrastructurally, the ischemic changes seen using light microscopy were confirmed. Morphometrically, there was a significant increase of mitochondrial size in the ischemic muscle compared with the control uninjured muscle but HBO did not markedly reduce these ultrastructural changes. It was concluded that the reduction of phosphorylase activity, a sensitive marker for muscle cell damage, is to a great extent prevented by HBO treatment in the post-ischemic phase.

Animals↗

Muscle changes in work-related chronic myalgia.

Muscle biopsies from the descending portion of the trapezius muscle were studied in 9 healthy subjects and in 10 patients with localized chronic myalgia related to static load during repetitive assembly work for 16 (10-31) years, with 10 (4-26) months of sick leave at the time of biopsy. Both categories showed isolated atrophic muscle fibers and occasional abnormal fibers with internally situated nuclei, some variation in fiber diameter, and fiber splitting. Fibers with a "moth-eaten" appearance due to a multifocal loss of oxidative enzyme activity were frequent both in the healthy and in the myalgic individuals. In contrast, isolated pathologic "ragged red" fibers were only found in the cases with myalgia (8 of 10), strongly suggesting mitochondrial damage. The phenomenon was confined to the Type 1 fibers. The frequency of Type 1 fibers was increased. Levels of adenosine triphosphate and adenosine diphosphate were reduced in myalgia patients, whereas lactate, pyruvate, and glycogen levels were normal, as well as phosphoryl creatine and total creatine.

Adult↗

Abnormal relaxation rates in subjects susceptible to malignant hyperthermia.

The acute malignant hyperthermia crisis appears to be mediated by a sudden and sustained rise in the concentration of sarcoplasmic calcium, leading to a prolonged muscle contraction. It is not known whether calcium metabolism in skeletal muscle is abnormal in malignant hyperthermia susceptible (MHS) subjects under normal conditions. A hypermetabolic state in skeletal muscle can be assessed in vivo by measuring relaxation rate. In the present study the relaxation rate was measured in the adductor pollicis muscle after electrical stimulation of the ulnar nerve. Ten MHS subjects with no clinical symptoms of muscle disease were investigated. Relaxation rates were found to be significantly higher in the MH-susceptible subjects compared with controls even under normal conditions (p less than 0.001). Determination of relaxation rate could thus be considered a possible addition to those methods currently available for the diagnosis of MHS.

Adolescent↗

Reduced high-energy phosphate levels in the painful muscles of patients with primary fibromyalgia.

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.

Adult↗

Clinical and muscle biopsy findings in malignant hyperthermia susceptibility.

Patients (155) were investigated for malignant hyperthermia susceptibility (MHS), by in vitro testing of muscle taken from the vastus medialis muscle. Histopathological and histochemical investigation of muscle was also performed. Ultrastructural investigation was performed in 13 MHS patients; 90% of the patients replied to a questionnaire concerning present or previous neuromuscular symptoms. The majority of MHS and MH negative (MHN) patients had no or only minor histopathological and histochemical abnormalities. Core-targetoid fibres were the only potentially important abnormalities found in MHS patients. There were no differences in neuromuscular symptoms between MHS, MHN and control patients, and most patients in both the MHS and MHN group were normal on clinical examination.

Adolescent↗

Primary fibromyalgia. A clinical and laboratory study of 55 patients.

The clinical symptoms of 55 patients with primary fibromyalgia (PF) were studied and compared with 30 patients with rheumatoid arthritis (RA). The PF patients expressed a more intense feeling of illness than did the RA patients. Stiffness occurred just as often in PF as in RA. Trigger points occurred less frequently in RA patients. Muscular fatigue appeared to be one of the most disabling symptoms in PF. Neurophysiological studies indicated that the fatigue was at least partly of central origin. Ischemic forearm exercise test gave no evidence of impaired glycogenolysis. Laboratory investigation revealed normal 25-hydroxyvitamin D, cobalamin, folate, estrogen, testosterone, and myoglobin in the PF patients.

Adult↗