bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunocytochemical study of dystrophin at the myotendinous junction
Authors: Samitt Craig E. , Bonilla Eduardo 
Published: January 2005

AbstractDystrophin is the protein whose deficiency results in Duchenne muscular dystrophy. The protein has homologies with a number of cytoskeletal proteins, is localized at the muscle sarcolemma and it may provide stability to the muscle plasma membrane. Using immunocytochemical techniques, we have studied dystrophin localization at the myotendinous junction, a region of membrane complexity that requires more stability because it is subjected to great mechanical stress during the transmission of contractile force to the tendon. The results showed subsarcolemmal deposits of dystrophin at the junctional folds of the myotendon as well as membrane‐associated dystrophin at extrajunctional sarcolemma. The findings suggest that dystrophin may be one of the components linking terminal actin filaments to the subplasmalemmal surface of the junctional folds of the myotendon.
Muscle biopsy in AIDS and ARC: Analysis of 50 patients
Authors: Gabbai Alberto A. , Schmidt Beny , Castelo Adauto , Oliveira Acary S. B. , Lima Jose G. C. 
Published: January 2005

AbstractWe report a large spectrum of histological muscle abnormalities in 50 homosexual men with AIDS and ARC. We encountered moth‐eaten fibers in 76%, angulated fibers in 76%, type groupings in 62%, type 2 fiber atrophy in 58%, mononuclear endomysial and/or perivascular in filtrates in 36%, necrosis and phagocytosis in 30%, and target fibers in 6%. Two patients showed vasculitis and two others showed perifascicular atrophy. On the whole, 96% of the biopsies showed substantial abnormalities. Muscle involvement in AIDS seems more common than previously suspected.
Effects of intermittent high frequency electrical stimulation on denervated EDL muscle of rabbit
Authors: Nix Wilfred A. 
Published: January 2005

AbstractThis study was performed to determine whether electrical stimulation can retard denervation‐induced changes. The denervated extensor digitorum longus of the rabbit, a fast‐twitch muscle, was stimulated at a rate mimicking its motoneuron firing pattern. The 100‐Hz stimulation given intermittently ubjected the muscle to a low mean total daily frequency of 1.6 Hz. Four weeks of stimulation resulted in no effect upon the denervated stimulated muscle. This stimulation protocol, therefore, is unable to substitute for the lost neuronal influence of the nerve. The muscle contralateral to the stimulated side showed physiological changes making it unsuitable to serve as a control.
Early myelin lesions in experimental allergic neuritis
Authors: Rosen Janet L. , Brown Mark J. , Hickey William F. , Rostami Abdolmohammad 
Published: January 2005

AbstractWe examined the evolution of demyelination in spinal roots of Lewis rats immunized with whole nerve and complete Freund' adjuvant. Roots were morphologically normal until 11 days after immunization, when we found endoneurial edema and myelin vesiculation in the absence of mononuclear cell contacts. Macrophage‐associated myelin stripping was not detected until day 12. Macrophage infiltrations were extensive by day 14, but lymphocytes were sparse. These observations indicate that in experimental allergic neuritis, myelin injury may occur before macrophage‐mediated demyelination, and provide support for an early role of serum factors in the development of this disorder.
Forearm ulnar‐to‐median nerve anastomosis of sensory axons
Authors: Hopf Hanns C. 
Published: January 2005

AbstractA 22‐year‐old man showed electrophysiological evidence of an ulnar‐to‐median nerve communication involving only sensory fibers. The nerve action potentials evoked by stimulation of the middle finger (ulnar side) and the ring finger (radial side) digital nerves were propagated with the median nerve at the wrist and the ulner nerve at the elbow. He was the only subject among 30 studied with this abnormality.
Clinical and electromyographic studies of postpoliomyelitis muscular atrophy
Authors: Ravits John , Hallett Mark , Baker Michael , Nilsson Jan , Dalakas Marinos 
Published: January 2005

AbstractEleven patients with progressive weakness following polio (postpoliomyelitis muscular atrophy syndrome) were compared electromyographically with nine patients who had stable strength following polio. Abnormalities included (1) abnormal motor unit characteristics in many muscles indicating widespread loss of motor neurons and reinnervation in muscles, including many not clinically affected by the polio; (2) prevalent spontaneous denervation potentials; and (3) abnormalsingle‐fiber electromyographic jitter. These electromyographic abnormalities were similar in progressive and stable postpoliomyelitis patients even when muscles were separated by strength, stability, age and duration of the postpoliomyelitis state. Postpoliomyelitis muscular atrophy appears to be the clinically apparent end of the spectrum of abnormalities existing in all postpoliomyelitis patients.
Aberrant reinnervation
Authors: Sumner Austin J. 
Published: January 2005

AbstractAlthough great empasis is placed on providing a satisfactory conduit for regeneration of peripheral axons after nerve repair, the quality of functional restoration is influenced as much by the quality as the quantity of axonal regeneration. Misdirected regeneration is so commonly encountered that motor axons appear to enter and regenerate to muscles in an almost random manner. Thus, when there are several choices, as usually is the case with more proximal nerve or plexus repairs, misdirected reinnervation accounts in many incidences for a poor quality of functional restoration. The regenerative capacities of type I and type II motor axons appear to differ. Proprioceptors and other sensory axons have been shown to reinnervate inappropriate end organs. Consequently, deranged central reflex modulation and disturbed orderly recruitment of motor units according to the size principle also contributes to this problem. Central re‐education or adaptation to misdirected regeneration does not occur to any appreciable extent.
Surgical repair of peripheral nerve injury
Authors: Kline David G. 
Published: January 2005

AbstractMagnification, useof fine interfascicular grafts for repair, and development of intraoperative electrophysiologic measurements of function have had a substantial impact on this field in the last 10 to 20 years. Basic surgical principles established during and since World War II remain the foundation for surgical repair of peripheral nerve injury but have been complemented nicely by these more recent advances. Selection of patients for surgery, as well as the timing of such, has been reviewed with emphasis on the differences between suspected transections and lesions in continuity, as well as comments on serious peripheral enterpments and tumors affecting nerve. The importance of not only preoperative electromyographic studies but also the intraoperative use of stimulation and stimulation and recording of nerve action potentials (NAPs) for lesions in continuity has been stressed. Operative techniques such as neurolysis, NAP recordings, suture, split repair, and interfascicular graft repair have been reviewed and some commentary on results provided. There has been a gradual evolution of centers in this country and abroad for care of the more serious surgical nerve problems. It is anticipated that in the future, such centers will be able to provide improved data concerning results with civilian nerve injuries.
Recording and physical characteristics of disposable concentric needle EMG electrodes
Authors: Nandedkar Sanjeev D. , Tedman Brian , Sanders Donald B. 
Published: January 2005

AbstractThere is currently considerable interest in using disposable concentric needle (CN) electrodes for clinical electromyography (EMG). To determine how these electrodes compare with reusable CN electrodes, we have compared signals recorded by these two electrode types from the same muscle in normal subjects. We also made similar recordings with two groups of reusable electrodes. There was no difference in the features of motor unit action potentials (MUAPs) recorded by the two groups of reusable electrodes. Disposable electrodes performed satisfactorily in conventional EMG examination. However, compared to reusable electrodes, the disposable electrodes recorded MUAPs with smaller amplitude and area but with the same area: amplitude ratio and MUAP duration. The physical and electrical properties of the CNE groups were also investigated. Disposable electrodes had lower electrical resistance and greater capacitance than reusable electrodes when measurements were made in saline. Photomicrographs showed that the disposable electrodes had smaller recording surfaces and that the central wire was frequently eccentric in the cannula. The differences in electrical recording characteristics could be due to differences in the size of the recording surface, eccentric placement of the central wire in the cannula or differences in the metal used for the central wire. We conclude that electrical and physical testing may not predict the recording characteristics of needle electrodes. Electrophysiologic testing is necessary to determine how EMG signals recorded by new types of electrodes compare with those recorded by currently used electrodes.
A comparison of magnetic and electrical stimulation of peripheral nerves
Authors: Olney Richard K. , So Yuen T. , Goodin Douglas S. , Aminoff Michael J. 
Published: January 2005

AbstractWe compared magnetic stimulation using different coil designs (2 rounded coils and a butterfly‐prototype coil) with electrical stimulation of the median and ulnar nerves in 5 normal subjects. Using magnetic stimulation we were able to record technically satisfactory maximal sensory and motor responses only with butterfly coil. Submaximal electrical stimuli preferentially activated sensory rather than motor axons, but submaximal magnetic stimuli did not. The onset latency, amplitude, are and duration of responses elicited electrically or magnetically with the butterfly coil during routine sensory and motor nerve conduction studies were similar, and motor and sensory conduction velocities were comparable when studied over long segments of nerve. However, the motor conduction velocities with magnetic and electrical stimulation differed by as much as 18 m/sec in the across‐elbow segment of ulnar nerve. Thus, recent developments in magnetic stimulator design have improved the focality of the stimulus, but the present butterfly coil design cannot replace electrical stimulation for the detection of focal changes in nerve conduction velocity at common entrapment sites, such as in the across‐elbow segment of the ulnar nerve.
Central motor conduction: Method and normal results
Authors: Claus Detlef 
Published: January 2005

AbstractNormal results of CMCT to upper extremities do not correlate with height, age, or sex. In cases of peripheral conduction slowing, upper limits of CMCT must be adapted. Cervical root excitation can be carried out by electrical or magnetic stimulation. The F wave technique also produces reliable results. Electrical stimulation of lumbar roots produces the most reliable results when measuring CMCT to leg muscles. CMCT to the tibialis anterior correlates with height, but not with age or sex. The same is true for intraspinal motor conduction time. Contraction of the target muscle enlarges CMAP amplitudes after cervical and transcranial stimulation. However, a latency shortening is only seen after brain stimulation. This is thought to be at least partially due to spatial summation of D and I waves. Age affects peripheral nerve conduction and central nerve conduction in different ways.
Diaphragmatic fatigue produced by constant or modulated electric currents
Authors: Jammes Yves , Collett Peter , Lenoir Patrick , Lama Abdelkalek , Berthelin Francis , Roussos Charis 
Published: January 2005

AbstractIn anesthetized rabbits the efficiency of phrenic nerve stimulation with trains of electric current was studied either when ventilation was effected entirely by bilateral nerve stimulation (electrophrenic ventilation) or during unilateral nerve stimulation when animals were ventilated with a pump and open chest. Trains of rectangular electric pulses (RPT) with constant amplitude and frequency or sine waves, both the amplitude and frequency of which were modulated and controlled by a computer (MSWT), were used with each animal. MSWT closely reproduced the physiological shape of transdiaphragmatic pressure waves. Diaphragm fatigue, as determined from the decrease in the maximal relaxation rate of twitches, occurred after 20 minutes of bilateral or unilateral nerve stimulation with RPT, but only after 60 min (unilateral stimulation) or 98 min (bilateral stimualtion) with MSWT. These data show the importance of the motor signal pattern in long‐lasting nerve stimulation.
Dystrophin: Localization and presumed function
Authors: Miyatake Masahiko , Teruhisa Miike , Zhao Ji‐En , Yoshioka Kowashi , Uchino Makoto , Usuku Gentaro 
Published: January 2005

AbstractTo determine the localization and functional significance of dystrophin, we studied various tissues from almost the entire body of control and mdxmice, and control rats, using polyclonal antibodies against dystrophin. We observed a dystrophin reaction in synaptic regions such as neuromuscular junctions, the equatorial region of intrafusal muscle fibers, the outer plexiform layer of the retina, the myoepithelial cell layer of salivary and sweat glands, tactile nerve endings, and neurons in the brain. These dystrophinpositive regions reportedly contain actin filaments as a common characteristic, which is compatible with the dystrophin cDNA sequence. Dystrophin was absent in these regions in mdx mice. These results suggest that dystrophin plays an important physiological and/or structural role in cell motility as a trigger for propagating contractile force in, for example, the conduction system, with some relationship between actin filaments.
Invited review: Myoblast transfer: A possible therapy for inherited myopathies?
Authors: Partridge Terence A. 
Published: January 2005

AbstractA potential therapeutic strategy for genetic diseases is to alter the genetic constitution of the affected tissues by means of grafts of normal precursor or stem cells. Over several years, evidence has accumulated to suggest that primary diseases of skeletal muscle, such as Duchenne muscular dystrophy, may be susceptible to this approach. This review makes a critical examination of such background evidence, and also of more recent data directly addressing the concept of therapy by means of grafts of normal myogenic cells. It is concluded that the data establish the principle that such grafts effect an alteration of the genetic constitution and phenotype of skeletal muscle and, therefore, might be used to alleviate recessively inherited myopathies. Several obstacles to the therapeutic application of this method to human disease are also identified; these seem to be problems of a technical nature rather than of basic principle, and none appears insuperable.
Expression of heat shock protein epitopes in tubular aggregates
Authors: Martin Joanne E. , Mather Kanti , Swash Michael , Gray Alan B. 
Published: January 2005

AbstractTubular aggregates may be found in a variety of conditions and have been associated with a wide range of chemical and ischemic insults. We report clinical and histological features in a case of myopathy with tubular aggregates. The structure of these tubular aggregates was examined using antibodies to cytoskeletal proteins and heat shock proteins. Epitopes of the 72 kD heat shock protein were expressed in the areas of abnormality in this case and in a case of hypokalemic periodic paralysis with tubular aggregates. Heat shock proteins have a role in the modulation of the tertiary structure of proteins and may be involved in the pathogenesis of tubular aggregates and other microtubular abnormalities in muscle.
AAEM case report #22: Polymyositis
Authors: Robinson Lawrence R. 
Published: January 2005

AbstractPolymyositis usually presents with progressive proximal muscle weakness, increased serum levels of muscle enzymes, inflammatory changes on muscle biopsy, and characteristic electromyographic (EMG) abnormalities. Motor unit action potential (MUAP) changes of configuration, duration, and amplitude are the most frequently observed EMG abnormality. Fibrillation potentials are commonly seen and tend to reflect active disease, diminishing after successful medical management or disease regression. Other muscle diseases can present with similar electromyographic abnormalities, thereby necessitating muscle biopsy for definitive diagnosis.
CO2 laser‐induced pain‐related somatosensory evoked potentials in peripheral neuropathies: Correlation between electrophysiological and histopathological findings
Authors: Kakigi Ryusuke , Shibasaki Hiroshi , Tanaka Kaoru , Ikeda Teruaki , Oda Ken‐Ichiro , Endo Chiyoko , Ikeda Akio , Neshige Ryuji , Kuroda Yasuo , Miyata Kiyonori , Yi Shigehiro , Ikegawa Shinichi , Araki Shukuro 
Published: January 2005

AbstractPain‐related somatosensory evoked potentials (pain SEPs) following co2 laser stimulation as well as conventional electrically stimulated SEPs (electric SEPs) were examined in 10 patients with peripheral neuropathies in whom the histopathological examination of the sural nerve was done. Results of pain SEPs showed a positive relationship with clinical impairment of pain sensation and densities of small myelinated fibers of the sural nerve. In contrast, results of electric SEPs showed a positive relationship with clinical impairment of deep and tactile sensations and with densities of large myelinated fibers of the sural nerve. Therefore, pain SEPs are considered to be generated by ascending signals mediated through nociceptive receptors and Aδ fibers. The pain SEP is only one noninvasive and objective method currently available to investigate a physiological condition of the sensory pathway responsible for pain sense, and is especially useful when combined with the conventional electric SEPs.
Ultrasound imaging of the quadriceps muscle in elderly athletes and untrained men
Authors: Sipila Sarianna , Suominen Harri 
Published: January 2005

AbstractUltrasound (US) technique was applied to measure the thickness, crosssectional area (CSA), and internal structure of the quadriceps muscle ih 70‐to 80‐year‐old endurance and power athletes and untrained men. Isometric knee extension strength was higher in the power athletes than in the other groups. The mean values for thickness and CSA did not differ between the athletes and the untrained men. The intensity of the intramuscula echo was, however, lower and the echo reflected from the connective tissue septa and bone was higher in the athletes than in the untrained men. Both the CSA and internal structure of the muscle group correlated signifjaayntly with muscle strength and number of training kilometers per year. The resuits suggest that long‐term training maintains the muscle architecture and counteracts the age‐related replacement of contractile tissue by other tissues such as fat.
Immobilization‐induced changes in motor unit force and fatigability in the cat
Authors: Robinson Grant A. , Enoka Roger M. , Stuart Douglas G. 
Published: January 2005

AbstractThe purpose of this study was to examine the effects of 3 weeks of immobilization on the mechanical properties of motor units in a cat hindlimb muscle. The muscle, tibialis posterior, was immobilized in a shortened position. Motor units were classified as type FF, F(int), FR, or S. Force, axonal conduction velocity, fatigability, and proportions of motor unit types were compared in control and immobilized muscles. All properties exhibited some change after immobilization, including slower axonal conduction velocities, greater twitch forces, slower twitch contraction times, and greater tetanic forces. In addition, most motor units were less fatigable after immobilization. The number of motor units that could not be included in one of the four classification categories increased significantly after immobilization; these units exhibited normal axon conductivity but failed to produce measurable force or associated EMG. Short‐term immobilization induced a variety of physiological adaptations in neuromuscular processes that varied with motor unit type.
Carnitine in muscle, serum, and urine of nonprofessional athletes: Effects of physical exercise, training, and L‐carnitine administration
Authors: Arenas J. , Ricoy J. R. , Encinas A. R. , Pola P. , D'Iddio S. , Zeviani M. , DiDonato Stefano , Corsi M. 
Published: January 2005

AbstractEfficient utilization of fatty acids to sustain prolonged physical efforts is thought to be dependent on the carnitine shuttle of muscle. A study has been carried out in 24 athletes (13 long‐distance runners and 11 sprinters). These subjects received placebo or L‐carnitine (1 g/orally b.i.d.) during a 6‐month period of training. In endurance athletes, training induced lowering of total and free muscle carnitine. Increase of esterified muscle carnitine was also observed. Post‐exertional overflow of acetylcarnitine and long chain acylcarnitine, as well as reduction of the free fraction was also noticed in the blood. Fasting plasma carnitine levels, however, were not affected in carnitine‐treated atheletes at rest. These changes were likely related with the significantly increased urinary excretion of esterified and total carnitine which occurred after physical exercise. In the sprinters only, a decrease in free and total carnitine of muscle was detected after training. Both these potentially unfavourable effects were prevented by oral administration of L‐carnitine. Our data suggest that training in endurance athletes, and to a lesser extent, in sprinters, is associated with a decrease in free and total carnitine of muscle, due to an increased overflow of short‐chain carnitine esters in urine.
Type 2 fiber predominance in lambert–eaton myasthenic syndrome
Authors: Squier Marian , Chalk Colin , Hilton‐Jones David , Mills Kerry R. , Newsom‐Davis John 
Published: January 2005

AbstractSerial muscle biopsies in a noncarcinomatous case of Lambert–Eaton myasthenic syndrome (LEMS) have shown progressive atrophy and loss of type 1 fibers, resulting in overwhelming type 2 predominance. A similar abnormality was found in a single biopsy from a second case of LEMS without associated carcinoma. Review of the literature suggests that type 2 fiber predominance has been observed in at least one other biopsied case. Interference with transmitter release caused by anti–voltage‐gated calcium channel antibodies may deprive type 1 muscle fibers of the low frequency discharge necessary to maintain their metabolic properties.
Acute peripheral arterial occlusion: Electrophysiologic study of 32 cases
Authors: Lachance Daniel H. , Daube Jasper R. 
Published: January 2005

AbstractThirty patients with 32 acute peripheral arterial occlusions underwent nerve conduction and electromyographic studies at a mean of 12.4 months after the vascular occlusion. Compound action potentials showed greater reduction than conduction velocity (26% to 75% vs 8% to 13% lower than normal). All changes were more prominent in the legs than arms, including fibrillation potentials (64% vs 28%). Short motor unit potentials were seen in extent of abnormality vareid with location of occlusion. Signs of nerve damage were significantly decreased in patients who had early revascularization. The electrophysiologic findigns suggested exonal destruction rather than demyelination.