bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neuromuscular disorders and thymoma
Authors: Witt N. J. , Bolton C. F. 
Published: January 2005

AbstractWe describe a patient who had asymmetrical atrophy of limb muscles and myasthenic weakness of neck, facial, and bulbar muscles. Electrophysiological tests indicated myasthenia gravis of facial muscles and changes consistent with an asymmetrical motor neuropathy as a cause of the muscle atrophy. Both conditions occurred as complications of a locally invasive thymoma, and both failed to improve after surgery and radiation but substantially improved with subsequent treatment by corticosteroids, azathioprine, and plasmapheresis. Review of the literature disclosed that several neuromuscular conditions may be associated with thymoma, the commonest being myasthenia gravis. Muscle atrophy may occur in 10% of patients who have myasthenia gravis, whether associated with or without thymoma. Its mechanism is debated, and further studies are needed, but observations in our patient suggest the atrophy is due to a motor neuropathy. Primary treatment of the thymoma by surgery, irradiation if the tumor is invasive, and immunosuppressive therapy for neuromuscular complications offers a relatively good prognosis for this group of patients.
Methods for estimating numbers of motor units in biceps‐brachialis muscles and losses of motor units with aging
Authors: Brown William F. , Strong Michael J. , Snow Robert 
Published: January 2005

AbstractThis paper presents a new method, here applied to the biceps‐brachialis muscles, for estimating motor unit numbers in healthy subjects. This method combines isometric contraction, intramuscular needle electrode recordings, and spike‐triggered averaging techniques to measure the sizes of motor unit potentials as recorded in the innervation zone with surface electrodes. The number of motor units is then estimated by division of the maximum biceps‐brachialis “M” potential recorded with the same surface electrodes and evoked by supramaximal stimulation of the musculocutaneous nerve, by the mean of at least 10 surface‐recorded motor unit potentials. The requisite intramuscular recordings provide additional information as to innervation density, incidence of linked potentials, and impulse blocking, phenomena that are particularly common in neurogenic and myogenic disoders. There was clear evidence of losses of motor units in older subjects: subjects over 60 years of age having approximately half the numbers of motor units of subjects under 60 years of age.
Regeneration of dystrophic muscle following multiple injections of bupivacaine
Authors: Martin Hunter , Ontell Marcia 
Published: January 2005

AbstractRegenerated myofibers formed subsequent to orthotopic transplantation of young, dystrophic mouse muscle fail to display the extensive histopathological changes characteristics of murine dystrophy.3 In order to determine whether this modification of the phenotypic expression of murine dystrophy is unique to the transplantation system or whether it can be found when other extreme trauma induces dystrophic muscle to regenerate, the extensor digitorum longus muscles of 4–6‐week‐old normal (129 ReJ +/+) and dystrophic (129 ReJ dy/dy) mice were given two series of injections of the myctoxin bupivacaine, spaced 12 hours apart. These injections resulted in necrosis of ∼90% of the original myofibers. At 100 days after injection, the regenerated normal muscle appeared “healthy,” whereas the regenerated dystrophic muscle displayed histopathological changes. It is suggested that the differences in the time course of innervation of the myotubes in the transplantation system as compared with that in the bupivacaine system may be a factor in determining whether regenerated dystrophic myofibers express a dystrophic morphology.
Stability of lumbosacral somatosensory evoked potentials in a long‐term follow‐up
Authors: Berić Aleksandar 
Published: January 2005

AbstractVariability of the lumbosacral somatosensory evoked potential (LSEP) in test/retest situations was assessed in 49 patients with nonprogressive neurological disorder and 20 healthy subjects. The average time of LSEP follow‐up in the patients was 16.2 months. The first group of healthy subjects had a short test/retest period of between 2 days and 2 weeks, and the second group had a long period between tests, with a mean of 35.7 months. The R and S waves of the LSEP were analyzed separately for latency and amplitude. Test/retest differences were statistically compared. The average correlation coefficient for healthy subjects was 0.84 and for patients was 0.78. These results suggested a remarkable stability of LSEPs in both healthy subjects and patients with nonprogressive neurological disorders. Therefore, we propose that LSEPs can be used in follow‐up both to screen for initial dysfunction of the sensory system and to detect any changes in present dysfunction.
Effect of desynchronized inputs on compound sensory and muscle action potentials
Authors: Kimura Jun , Sakimura Yoko , Machida Masafumi , Fuchigami Yasunori , Ishida Tetsuro , Claus Detlef , Kameyama Shigeki , Nakazumi Yuji , Wang Jin , Yamada Thoru 
Published: January 2005

AbstractStimulation of the second (S1) or third (S2) digit elicits a median sensory potential at the wrist. Similarly, a shock applied to the median (Sm) or ulnar (Su) nerve at the wrist evokes a sensory potential of the fourth digit and a muscle potential over the thenar eminence. Hence, a concomitant application of S1 and S2 or Sm and Su with varying interstimulus intervals simulates the effect of desynchronized inputs. In 10 hands, a shift in latency on the order of 1 msec between S1 and S2 or Sm and Su caused a major reduction in sensory potential by as much as 30–40% but little change in muscle action potential. A latency difference slightly less than one‐half the total duration of unit discharge maximized the phase cancellation between the two components and consequently the loss of area under the wave‐form.
Comparison of force and stiffness in normal and dystrophic mouse muscles
Authors: Gordon T. , Stein R. B. 
Published: January 2005

AbstractIsometric force and stiffness of fast‐ and slow‐twitch muscles of affected and normal mice of the 129/ReJ dy/dy strain were studied at rest and during active contraction at a variety of lengths. Dystrophic muscles developed less force in response to stimulation, but the resting stiffness was not reduced as much, particularly at long muscle lengths. This is consistent with the replacement of muscle fibers by connective tissue that is considerably less elastic. When second and third stimuli are superimposed on the rising phase of a twitch in a normal muscle, a less‐than‐linear summation of force and stiffness generation (early depression) is followed by a more‐than‐linear summation (later facilitation). Dystrophic muscles showed a smaller early depression and a greater later facilitation of force and active muscle stiffness. Many of these phenomena can be predicted from a simple model of Ca2+ release and binding to troponin.
Immunocytochemical localization of α‐actinin in frog muscle treated with the ionophore A23187
Authors: Llados Fernando T. , Kriho Virginia , Pappas George D. 
Published: January 2005

AbstractIncubation of frog skeletal muscle with the ionophore A23187 induces severe damage in the muscle. At the level of the Z line, the ionophore induces redistribution and release of the protein α‐actinin, as shown by immunocytochemical techniques. The ionophore does not induce damage in denervated preparations or in preparations pretreated with d‐tubocurarine, which indicates that the effect is indirect and neurally mediated. It is concluded that the increase in spontaneous transmitter release produced by the ionophore induces Ca2+ influx through the acetylcholine receptor. Calcium ions activate neutral proteases which release α‐actinin from the Z line.
AAEE minimonograph #31: The electrodiagnosis of ulnar neuropathy at the elbow
Authors: Kincaid John C. 
Published: January 2005

AbstractSuspected ulnar neuropathy at the elbow is commonly evaluated in the electromyography lab. In this report the anatomy and pathology of ulnar elbow lesions are reviewed. The patterns of electrophysiologic abnormality that have been reported in the literature and in the author's own laboratory are discussed along with a suggested routine for evaluation.
Isomyosin changes after functional electrostimulation of denervated sheep muscle
Authors: Carraro Ugo , Catani Claudia , Saggin Leopoldo , Zrunek Michael , Szabolcs Mathias , Gruber Helmut , Streinzer Wilhelm , Mayr Winfried , Thoma Herwig 
Published: January 2005

AbstractIsomyosin analyses by biochemical, immunochemical, and histochemical investigations have been carried out in five sheep following unilateral recurrent laryngeal nerve paralysis and direct functional electrostimulation of the denervated cricoarytenoid posterior muscle. Myosin light chains were identified by two‐dimensional gel electrophoresis. Myosin heavy chains were analyzed by one‐dimensional SDS‐polyacrylamide gel electrophoresis. Slow myosin heavy chain was identified by orthogonal peptide mapping and immunochemistry. The stimulation effect at cellular level was determined using adenosine triphosphatase (ATPase) histochemistry. A dramatic increase of the type 1 fiber area (slow, fatigue‐resistant fibers) could be seen after many weeks of an increasing regime of low‐frequency direct electrical stimulation. Biochemically, the amout of slow myosin was always higher than in normal muscles. Some muscles were transformed almost completely to the slow type. At the time they were studied and with the methods employed, the expression of embryonic isomyosin was not observed. In conclusion, after numerous weeks of maintained functional activity, elicited by direct electrostimulation, the denervated muscle regionally showed areas of hypertrophy or at least lack of atrophy of slow myofibers without major signs of muscle damage.
The distribution of slow myosin in rat muscles after neonatal nerve crush
Authors: Lowrie Margaret B. , Dhoot Gurtej K. , Vrbova Gerta 
Published: January 2005

AbstractFollowing neonatal nerve injury fast skeletal muscles recover less well than slow ones. This is because many muscle fibers are lost during reinnervation. Since fast muscles normally contain a small population of slow muscle fibers, we have used a monoclonal antibody to slow myosin heavy chains (SMHC) to study their number and pattern of distribution in fast muscles following temporary denervation at 5–6 days of age and subsequent reinnervation. During this time the original distribution of slow fibers changed to one showing irregular grouping, indicating that reinnervation of muscles after neonatal nerve injury is as nonselective as it is after nerve injury in adults. Despite a large reduction in the total number of muscle fibers during reinnervation, the number of slow fibers did not decrease. Thus muscle fiber loss was at the expense of the fast motor units alone.
The human cervical myotomes: An antatomical correlation between electromyography and CT/myelography
Authors: Katirji M. Bashar , Agrawal Rakesh , Kantra Trudy A. 
Published: January 2005

AbstractTo correlate the accuracy of electromyography in diagnosing the correct root involved in cervical radiculopathy, 20 patients with cervical radiculopathy, diagnosed by electromyography using strict inclusion and exclusion criteria, were studied. Metrizamide myelography/computerized tomography were evaluated in all 20 patients independently, and the involved root was defined. The root involved, using the EMG examination and the myotome chart of the Medical Research Council, was C5 in 3 patients, C6 in 6, C7 in 9 patients, and C8 in 2 patients. The overall correlation with myelography/CT was 65% (33.3, 66.6, 77.7, and 50% for C5, C6, C7, and C8, respectively). EMG done properly has a good correlation of myelography/CT. This correlation is higher (73.3%) for the commonly occurring cervical radiculopathies (C6 and C7).
X‐linked dominant charcot–marie–tooth neuropathy with 15 cases in a family genetic linkage study
Authors: Ionasescu Victor V. , Burns Trudy L. , Searby Charles , Ionasescu Rebecca 
Published: January 2005

AbstractA large CMT family with 5 affected males and 10 affected females of 37 members in four generations was investigated by recombinant DNA studies. The proband patient in his original desscription of the pedigree indicated male‐to‐ male transmission in one of his relatives, suggesting autosomal dominant inheritance. The genetic linkage study between the CMT locus and the loci of six markers mapped on chromosome 1 (FY, APCS, AT3, REN, APOA2, and GBA) gave negative results. These findings prompted further pedigree investigation which proved that male‐to‐male transmission was not present. A genetic linkage study with DXYS1, which is a DNA marker mapped on the long arm of the chromosome X, revealed tight linkage with ẑ = 3.15 at θ = 0.10.
Clinical investigation in Duchenne muscular dystrophy: Penicillamine and vitamin E
Authors: Fenichel Gerald M. , Brooke Michael H. , Griggs Robert C. , Mendell Jerry R. , Miller J. Phillip , Moxley Richard T. , Park Jane H. , Provine Michael A. , Florence Julaine , Kaiser Kenneth K. , King Wendy M. , Pandya Shree , Robison Jenny , Signore Linda 
Published: January 2005

AbstractA double‐blind controlled trial of penicillamine and vitamin E against placebo was conducted in 106 boys with Duchenne muscular dystrophy. Nine dropped out of the study after being randomized. Patients were evaluated using an established protocol that measures muscle strength, joint contractures, functional grade, and pulmonary function. The trial lasted for 18 months. The power of the study to detect a 75% slowing of the disease was 0.95 at a P < 0.05. No therapeutic effect was observed in the patients taking penicillamine and vitamin E as compared with those taking placebo.
Structural and functional analysis of murine skeletal muscle after castration
Authors: Bmed Bian Jiang , Klueber Kathleen M. 
Published: January 2005

AbstractA previous histochemical and morphometic study demonstrated that castration caused a significant decrease in myofiber and muscle size in the extensor digitorum longus (EDL) muscles of male ReJ 129 mice. The objective of the present study was to examine the effects of castration on the morphology and physiology of the EDL. Muscle wet weight was significantly decreased in the castrated group. The morphological survey demonstrated a significant degree of degeneration in the EDL muscles from castrated animals, consisting of disruption of normal myofilament arrangement and necrosis, invasion of active macrophages, and atrophic myofibers. These findings were significantly correlated with the decrease in peak tension observed in the castrated groups. No significant difference was detected in the time to peak tension and half‐relaxation time in the castrated groups compared with the control. Thus, alterations of the morphological integrity and myofiber size of skeletal muscle affect muscle strength in castrated animals.
Hereditary increased muscle mechanical irritability and progressive contracture with stretch‐induced electromyog‐raphic activity
Authors: Jušić Anica 
Published: January 2005

AbstractA son and mother are reported with autosomal dominantly transmitted painless, increased mechanical irritability in the limb and trunk muscles and progressive finger contracture. Immediately after a tap, muscle swelling appeared. With light tapping, wavelike muscle surface movements appeared. Progressive contractures developed first in the proximal interphalangeal finger joints and subsequently involving the lower arm muscles. The contractures disappeared in the local curare test. No spontaneous activity was recorded on concentric needle recording. Serial repetitive activity was recorded with fine wire electrode recording, induced by muscle stretch, performed by percussion hammer blows or by prolonged finger grasp. A slight, irritative peripheral nervous lesion could be the cause. The chronic sensorimotor polyneuropathy may be also a part of the syndrome.
Evaluation of an automatic method of measuring features of motor unit action potentials
Authors: Stewart Charles R. , Nandedkar Sanjeev D. , Massey Janice M. , Gilchrist James M. , Barkhaus Paul E. , Sanders Donald B. 
Published: January 2005

AbstractThis study was performed to evaluate an automatic method of motor unit action potential (MUAP) analysis developed in our laboratory. MUAPs were recorded from the biceps brachii muscle of 68 normal subjects and 122 patients with nerve or muscle disease. The values of mean MUAP durations from normal subjects obtained by automatic analysis were similar to those reported in the literature. However, the normal range of MUAP amplitude and the incidence of polyphasic MUAPs were much higher. Normal ranges of mean MUAP area, area/amplitude ratio, and the number of turns were also defined. Automatic analysis demonstrated an abnormality of at least one MUAP feature in 70% of patients. There was concordance between automated analysis and visual assessment of MUAPs in 76% of patients with neuropathy but in only 50% of patients with myopathy. The relationships between different MUAP features seen in neuropathy and myopathy are explained in physiologic terms.
Mechanisms that produce rapid damage to myofilaments of amphibian skeletal muscle
Authors: Duncan Christopher J. 
Published: January 2005

AbstractThe system causing myofilament damage is separate from the phospholipase A2 pathway, Ca activation of which ultimately causes sarcolemma breakdown in muscle cells. Mitochondrial agents cause myofilament damage in saponin‐skinned frog pectoris cutaneous muscle when [Ca] = 0. There are parallels with other systems that generate oxygen radicals. However, a variety of protectors against oxygen radicals, or anoxia, failed to protect; Ca‐activated damage was not augmented by diethylthicarbamate, nor was it accompanied by a respiratory burst. Thus, there is no firm evidence implicating oxygen radicals in myofilament damage. Thiol‐oxidizing agents cause contraction damage in skinned muscle that resembles the quasirigor induced in myosin by N‐ethylmaleimide. Activation of transmembrane dehydrogenases and electron flow produced damage and increased Ca sensitivity in skinned muscle, and it is suggested that this enzyme system may be implicated in characteristic damage to the myofilaments via redox cycling and modification of sulphydryl groups; its possible location on the sarcoplasmic reticulum is discussed.
Scanning electron microscopy of teased intrafusal muscle fibers from rat muscle spindles
Authors: Schröder J. Michael , Bodden Herbert , Hamacher Alfred , Verres Christoph 
Published: January 2005

AbstractScanning electron microscopic (SEM) studies on intrafusal muscle fibers and their various sensory and motor endings are not available thus far although SEM greatly increases the resolution power for analyzing surface structures in comparison to light microscopic preparations. From a total of 68 isolated muscle spindles in lumbrical muscles of Wistar rats, only one primary sensory ending could be isolated. Secondary sensory endings were of an annulospiral, a flat, cuff‐shaped, or a more complicated branched type; they were always completely surrounding intrafusal muscle fibers. Motor terminals were more focally arranged not surrounding the muscle fibers. Three types could be distinguished. Collagen fibrils were seen to insect on capsular elements as well as on the surface of intrafusal muscle fibers. Thus SEM helps understanding the most complicated electromechanical system for motor control.
Spontaneous diabetes mellitus in a rhesus monkey: Neurophysiological studies
Authors: Cornblath David R. , Dellon A. Lee , MacKinnon Susan E. 
Published: January 2005

AbstractPeripheral neuropathy is a common complication of human diabetes, but its occurrence in spontaneously diabetic monkeys is unknown. Four months after developing diabetes, a 22‐year‐old female rhesus monkey had nerve conduction studies which were compared with control data obtained from 9 nondiabetic rhesus monkeys. In the diabetic monkey, median and ulnar sensory action potential amplitudes and the median motor distal latency differed from controls by more than two standard deviations. Conduction velocities in the diabetic monkey were less than the mean values in controls, although none were beyond two standard deviations of control means. These electrophysiologic abnormalities are similar to those described in human diabetes and suggest that the spontaneously diabetic monkey peripheral nervous system may be a suitable model of experimental diabetic neuropathy.
Proteins of muscle subcellular fractions in Duchenne progressive muscular dystrophy stained with “Stains‐all” cationic carbocyanine dye and with Coomassie blue
Authors: Niebroj‐Dobosz I. , Kornguth S. , Schutta H. , Siegel F. L. , Hausmanowa‐Petrusewicz I. 
Published: January 2005

AbstractThe protein compositions of subcellular fractions of muscle obtained from 17 Duchenne dystrophy patients, 15 disease controls (10 different primary myopathies, 5 spinal muscular atrophy patients), and 10 normals were examined by polyacrylamide gel electrophoresis. The gels were stained with Coomassie Brilliant Blue and with “Stains‐all,” which stains calcium‐binding proteins, sialic acid‐rich glycoproteins, and phosphoproteins. In muscle membrane fractions of Duchenne dystrophy patients there was a marked reduction in the concentrations of calsequestrin and a 39 kDa protein that stained blue with “Stains‐all.” There were changes in the proteins of all sub‐cellular fractions of Duchenne's patients; some of these changes appear to be specific for Duchenne dystrophy (DD). There was no apparent correlation between the protein changes observed on acrylamide gels and the age of the patients, the duration of the disease, the degree of disability, or activity of creatine kinase. A decreased level of calsequestrin in DD sarcoplasmic reticulum may contribute to an increased level of free calcium seen in muscle from these patients.
Muscle glycerol kinase in Duchenne dystrophy and glycerol kinase deficiency
Authors: Seltzer William K. , Angelini Corrado , Dhariwal Gulshan , Ringel Steven P. , McCabe Edward R. B. 
Published: January 2005

AbstractThe complex glycerol kinase deficiency (GKD) syndrome is an X‐linked recessive genetic disorder. The syndrome often includes a myopathy that is similar histologically to Duchenne muscular dystrophy (DMD). The glycerol kinase (GK) locus is in the Xp21 region in the midportion of the short arm of the X chromosome and is in close proximity to the DMD locus. We have investigated GK activity and subcellular distribution of muscle GK in DMD patients and in a patient with the complex GKD syndrome presenting with myopathy. We found no abnormality of muscle GK specific activity or sub‐cellular distribution in DMD. In the patient with the complex GKD syndrome the specific activity and kinetics of muscle GK were normal, but the subcellular distribution of muscle GK was altered. Liver GK had less than 10% of normal activity and showed markedly altered kinetics. These findings indicate that there is no abnormality of muscle GK activity in DMD muscle. Furthermore, the normal GK activity in an individual with the complex GKD syndrome suggests that muscle and liver GK are genetically distinct. These findings support the concept that the complex GKD syndrome results from small deletions that affect closely linked but separate loci for DMD, GK and adrenal hypoplasia.