bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction by 31P‐NMR of the irreversibility of ischemic injury in rat skeletal muscle after ligation of the femoral artery
Authors: Authier B. , Rossi A. , Albrand J. P. , Decorps M. 
Published: January 2005

AbstractRat leg muscles, rendered ischaemic 1 hour previously by ligation of the femoral artery, were submitted to 20 minutes exercise by electrical stimulation of the sciatic nerve. 31P‐NMR spectroscopy was used to monitor the changes in high‐energy phosphate content of the muscles before, during, and after exercise. Fifteen of the 35 studied muscles evolved toward total necrosis, whereas the others showed signs of recovery over a 2–5‐hour postexercise period. Those muscles which did not subsequently recover contained significantly more inorganic phosphate (Pi) at rest (before exercise) than those which recovered. It is suggested that under acute ischaemic conditions the Pi level at rest is correlated with the extent of blood flow restriction and can be used to predict the severity of the ischemia.
Myosin heavy chain composition of muscle fibers in spinal muscular atrophy
Authors: Biral Donatella , Scarpini Elio , Angelini Corrado , Salviati Giovanni , Margreth Alfredo 
Published: January 2005

AbstractMuscle biopsies from 20 cases of spinal muscular atrophy (SMA), mostly diagnosed as Werdnig–Hoffmann (W–H) disease, were examined for myosin heavy chain (HC) composition. The fetal, fast, and slow heavy chains were characterized in the isolated muscle myosin, and in myosin of single, chemically skinned fibers, by electrophoresis in SDS‐6% polyacrylamide gels and by immunoblot techniques, using specific antibodies directed to each main type of myosin HC. The fiber distribution of myosin HC isozymes was further investigated on muscle cryostat sections by an indirect immunofluorescent technique. Fetal myosin HC was found to be expressed in a subpopulation of severely atrophic fibers, alone or together with the slow form of myosin HC. Triangulated fibers of intermediate size contained fetal and fast myosin or fast myosin alone. The hypertrophic fibers were characterized by the predominant expression of slow myosin HC; but in some of these fibers, also low amounts of HC fetal were found to be expressed. These findings are discussed in relation to developmental transitions of myosin heavy chains in human muscle.
Recording sound from human skeletal muscle: Technical and physiological aspects
Authors: Bolton Charles F. , Parkes Anthony , Thompson Terry R. , Clark Michael R. , Sterne Chris J. 
Published: January 2005

AbstractIn order to examine technical factors that influence muscle sound recording, single twitches of muscle were utilized since their waveforms were likely to be reproducible. We observed that satisfactory recordings could be made with either Archer air interface, or Hewlett‐Packard direct contact sensor, microphones. Firm contact and stability between the microphone and the skin surface were particularly important. Frequencies below 20 Hz, the lower limit of the human auditory range, must be recorded, since they account for at least 90% of the power of the muscle sound wave. The chief frequencies were below 4 Hz.The sound wave produced by a maximal twitch of human thenar muscle induced by median nerve stimulation at the wrist is maximal in amplitude over the center and recedes to near zero at the margins of the muscle. It is preceded by the muscle compound action potential and is followed by the force curve, recorded with a strain gauge attached to the thumb. The sound resembles force in total time course, and it increases with increasing strengths of nerve stimulation. However, it differs in its latency, phase relationships, and response to nerve stimulation at different frequencies. Some of the features of muscle sound suggest it relates to both the active contractile and the parallel elastic components of muscle during a twitch contraction, but not the series elastic component.
Fibrillatory activity and other membrane changes in partially denervated muscles
Authors: Arancio Ottavio , Cangiano Alberto , De Grandis Domenico 
Published: January 2005

AbstractRat soleus muscles were partially or totally denervated by sectioning the radicular nerve L5 or the radicular nerves L3 through L6, respectively. Three days after these procedures, fibrillation potentials were not observed in the case of partial denervation, whereas they were clearly detectable after total denervation. At later times, spontaneous spike activity also developed in the partially denervated muscles. The difference in time of onset of fibrillation between partially and totally denervated muscles was confirmed by a more gradual increase in the number of acetylcholine receptors and a greater sensitivity to tetrodotoxin of the former muscles. These differences between partially and totally denervated muscles are interpreted on the basis of the different amounts of nerve breakdown products generated in the two situations.
The in vitro determination of susceptibility to malignant hyperthermia
Authors: Iaizzo Paul A , Lehmann‐Horn Frank 
Published: January 2005

AbstractTo evaluate the reliability of the in vitro contracture test for susceptibility to malignant hyperthermia, we studied muscles from normal pigs and those susceptible to malignant hyperthermia. We performed the contracture test with various muscles from the same animal. Trapezius and intercostal muscles gave similar results, whereas the extensor digiti II muscle had lower sensitivities to both caffeine and halothane. Thus, the muscle chosen to determine susceptibility to malignant hyperthermia is important. In several animals, a false negative diagnosis would have resulted if only the distal muscle had been studied, and this was true even if weak contractures (<200 mg) were considered significant. In addition, we compared the response to caffeine or halothane of cut and intact muscle fibers. Although the cut fibers were depolarized, the sensitivity to these drugs was unchanged. Hence, results of the in vitro contracture test are independent of the resting membrane potential.
Handcuff neuropathy revisited
Authors: Scott Thomas F. , Yager John G. , Gross John A. 
Published: January 2005

AbstractPeripheral nerve injury due to handcuff placement has been reported in the past, always involving the superficial radial nerve, and sometimes involving other peripheral nerves at the wrist. We present two unusual cases in which the ulnar nerves were affected, but the radial nerves were normal or only minimally affected. This serves to emphasize a broader clinical spectrum of handcuff injury. Significant disability may result. These cases also involve alcohol intoxication, which may predispose patients to this type of injury because of overly aggressive application of restraints motivated by the patients' bellicose behavior.
Duchenne muscular dystrophy: A study of wrist and hand function
Authors: Wagner Marilyn B. , Vignos Paul J. , Carlozzi Chris 
Published: January 2005

AbstractThe wrist and hands of 18 Duchenne muscular dystrophy (DMD) patients were assessed for abnormalities. The subjects were divided into three groups by age. Flexion and ulnar deviation contractures of the wrist began in the youngest age group, 8–14 years. Other abnormalities, present in all age groups, included extrinsic and Intrinsic digital muscle shortness, boutonniere and swan neck deformities, and hyperextension of the digital interphalangeal joints. Pain found with passive proximal interphalangeal joint flexion has not been reported previously. This study supports the importance of early assessment of the wrist and hand in DMD and suggests intervention techniques to possibly retard the deforming process.
Abnormalities of the fast sodium current in myotonic dystrophy, recessive generalized myotonia, and adynamia episodica
Authors: Rüudel Reinhardt , Ruppersberg Johann Peter , Spittelmeister Wolfgang 
Published: January 2005

AbstractMyoballs, i.e., spherical muscle cell regenerates, were cultured from the biopsied muscles of three patients with myotonic dystrophy, three patients with recessive generalized myotonia, and a patient with adynamia episodica. The membrane of these myoballs was voltage‐clamped in the whole‐cell mode for the recording of sodium currents (at 11, 24, and 37°C). The voltage dependence of the steady‐state activation and inactivation curves showed only minor abnormalities in all cases. The time constants of activation (τm) and inactivation (τh), when studied at the three temperatures, showed a characteristic pattern of abnormalities. In myotonic dystrophy, both τm and τh were larger than control; in recessive generalized myotonia and adynamia episodica both τm and τh were smaller than control. In the latter diseases, these time constants also showed a smaller than normal decrease with membrane depolarization. The changes seen for recessive generalized myotonia and adynamia episodica would favour the occurence of myotonia, the opposite results for myotonic dystrophy would oppose myotonia.
Therapeutic strategies in promoting peripheral nerve regeneration
Authors: Horowitz Steven H. 
Published: January 2005

AbstractCurrently, regeneration chambers, adrenocorticotropic hormone (ACTH) and related peptides, and gangliosides appear to be the most promising therapies in the promotion of peripheral nerve regeneration, growth, and repair. Regeneration chambers enhance rat sciatic nerve regeneration in vivo after transection by providing a structurally organized and protected preformed space within which nerve fibers are exposed to macromolecular compounds which direct and enhance nerve growth. ACTH and related peptides, independent of their corticotropic activities, increase the availability of structural proteins to the axon terminal in rats subjected to nerve crush injuries and demonstrate inotropic effects in adrenalectomized and/or hypophysectomized rats. Exogenously administered gangliosides promote neuronal sprouting, regeneration, and reinnervation in experimental situations and have undergone clinical testing in acute and chronic peripheral nerve disorders. At the current dosage levels and schedules, the clinical results of ganglioside therapy have been mixed. The success of the experimental studies supports further clinical testing of these therapies in peripheral nerve disorders.
Electromyographic evaluation of an accessory hand muscle
Authors: McManis Philip G. , Daube Jasper R. 
Published: January 2005

AbstractAccessory hand muscles consistent with extensor digitorum brevis manus muscles were noted in a young women. Well‐defined compound muscle action potentials were elicited in these muscles with stimulation of the radial nerve. Needle electromyography showed poor recruitment and large motor unit potentials with frequent cramp discharges only in the anomalous muscles. Therefore, the extensor digitorum brevis manus is innervated by the posterior interosseous nerve, and symptoms may be due to chronic denervation and cramping.
Single‐fiber EMG study of the flexor carpi radialis H reflex
Authors: Jabre Joe F. , Stålberg Erik V. 
Published: January 2005

AbstractLate responses were studied in the flexor carpi radialis muscle by surface‐recording and single‐fiber electromyography. By single‐fiber studies we were able to distinguish 2 distinct components. One was an H reflex obtained without a preceding M response and with a stimulus response jitter of about 100 μsec; its latency was shortened and jitter decreased with the Jendrassik maneuver. The other was an F wave always preceded by an M response and with a stimulus response jitter of under 50 μsec; its jitter and latency are unaffected by the Jendrassik maneuver. At the single‐fiber level it was possible to determine the rate of occurrence of individual H reflexes and F responses for a given number of surface‐applied stimuli. The H reflex had a very high rate of occurrence (up to 97%), whereas the F wave occurred very infrequently (less than 2% of the time). Using the H reflex rate of occurrence in conjunction with the maximal surface H/M amplitude ratios allowed us to determine the proportion of alpha motor neurons which participate in the H‐reflex generation. The study of H‐reflex jitter gives an estimate of the central synaptic jitter and effectiveness of the spatial and temporal summation of type 1a fiber inputs on the motor neurons.
AAEE minimonograph #33: Electrodiagnostic approach to defects of neuromuscular transmission
Authors: Keesey John C. 
Published: January 2005

AbstractClinical testing for neuromuscular dysfunction is supported by an extensive amount of excellent basic information about normal and abnormal subcellular physiology and ultrastructure. This information provides an essential frame of reference for describing the rationale of single‐fiber electromyography (SFEMG). SFEMG in turn helps to explain the more conventional clinical testing of neuromuscular function by repetitive nerve stimulation (RNS). Electrical findings in myasthenia gravis, Lambert–Eaton myasthenic syndrome, and botulinum intoxication are discussed from the subcellular level via the cellular level (SFEMG) to the integrated responses of whole muscle (RNS) as a rational means of understanding the technique of clinical repetitive nerve stimulation.
Coexpression of myosin isoforms in muscle of patients with neurogenic disease
Authors: Sawchak Judith A. , Lewis Simeon , Shafiq Saiyid A. 
Published: January 2005

AbstractThree well‐characterized antimyosin heavy chain monoclonal antibodies (McAbs) were used as immunocytochemical reagents to study myosin iso‐form expression in relationship to adenosine triphosphatase (ATPase) defined fiber types in human muscle. The biopsy specimens were from patients with neurogenic muscle disease whose muscle exhibited fiber type grouping and group atrophy. The use of McAbs revealed heretofore unrecognized coexpression of multiple myosin isoforms in selected fibers in the pathologic samples which was not apparent with ATPase reactions and not present in normal muscle. The fibers containing multiple myosin isoforms were probably undergoing neurally directed fiber type transformation. Furthermore, a small population of fibers in neurogenic specimens expressed a “prenatal” myosin signifying the presence of regenerating fibers. We also demonstrated immunocytochemical evidence of the persistence of adult slow myosin in denervated mature human skeletal muscle despite the reputed necessity of innervation for maintenance of expression of this myosin isoform proffered by others.
Localization and characterization of dystrophin in muscle biopsy specimens from Duchenne muscular dystrophy and various neuromuscular disorders
Authors: Uchino Makoto , Araki Shukuro , Miike Teruhisa , Teramoto Hitoo , Nakamura Tetsuji , Yasutake Toshiaki 
Published: January 2005

AbstractDystrophin, surmised to be the causative protein of Duchenne muscular dystrophy (DMD) was studied for its intracellular localization and characterization by immunostaining and Western blotting using antidystrophin antibodies. In normal controls and in patients with various neuromuscular diseases other than DMD and Becker's muscular dystrophy (BMD), dystrophin was detected homogeneously on the entire surface membrane of the muscle fibers, whereas it was absent in DMD patients and partially observed in BMD cases. The density of dystrophin was low in BMD and female DMD patients. In mouse skeletal and cardiac muscles, too, dystrophin localized in the muscle surface membrane, and its presence in the brain was also suggested. However, dystrophin was not detected in mdx mice. These data suggest that myofiber necrosis in DMD patients and mdx mice is likely to be the result of plasma membrane instability.
Paramyotonia congenita or hyperkalemic periodic paralysis? Clinical and electrophysiological features of each entity in one family
Authors: de Silva Shari M. , Kuncl Ralph W. , Griffin John W. , Cornblath David R. , Chavoustie Steven 
Published: January 2005

AbstractThe nosological distinction between paramyotonia congenita (PC) and hyperkalemic periodic paralysis (HPP) continues to generate debate. Recently, electrophysiological signs thought to be specific for each entity have been described and have been used to bolster the argument that the two disorders are distinct. We report a particularly instructive family wherein individual members had clinical features of either PC or HPP and electrophysiological features of both. We suggest that PC and HPP represent part of the spectrum of a single genetic disorder. Evoked response testing, with exercise and cold provocation, may be useful in determining the physiologic pattern that predominates in any one individual.
Neurofibromatous neuropathy
Authors: Thomas P. K. , King R. H. M. , Chiang T. R. , Scaravilli F. , Sharma A. K. , Downie A. W. 
Published: January 2005

AbstractThree cases of chronic distal sensorimotor neuropathy are described in patients with neurofibromatosis. One had type 2 or central neurofibromatosis with a chromosome 22 deletion; the precise form of the disease was not established in the other two. A striking clinical feature was a diffuse nodular enlargement of the peripheral nerves. Nerve biopsies from all three cases demonstrated the presence of neurofibromatous pathology. Neurofibromatous neuropathy constitutes a rare manifestation of neurofibromatosis, related to diffuse neurofibromatous changes in the peripheral nerves.
Steroid‐responsive electromyographic abnormalities in polymyalgia rheumatica
Authors: Bromberg Mark B. , Donofrio Peter D. , Segal Barbara M. 
Published: January 2005

AbstractPrior to definitive diagnosis, electrodiagnostic studies are often requested in patients with polymyalgia rheumatica to evaluate complaints of muscle aching, tenderness, and weakness. These studies are generally normal, although rare reports of electromyographic abnormalities in polymyalgia rheumatica exist. Two patients with polymyalgia rheumatica and electro diagnostic findings consistent with diffuse denervation are described. Following steroid treatment, both patients experienced impressive clinical and electromyographic improvement. To explain this improvement, we hypothesize a steroid‐responsive microvascular arteritis resulting in ischemic damage to axons of motor nerve terminal branches.
Electromyographic and morphological functional compensation in late poliomyelitis
Authors: Einarsson Gisli , Grimby Gunnar , Stålberg Erik 
Published: January 2005

AbstractPatients 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%.
Toward more rational nerve conduction interpreations: The effect of height
Authors: Rivener Micheael H. , Swift Thomas R. , Crout Barbara O. , Rhodes Karen P. 
Published: January 2005

AbstractOne hundred four normal subjects ranging in age from 17 to 77 years and in height from 115 to 203 cm underwent nerve conduction studies of sural, peroneal, tibial, and median nerves. Foot temperature was measured in each patient. A strong inverse correlation was found between height and sural (r = −0.7104), peroneal (r = −0.6842), and tibial (r = −0.5044) conduction velocities. These correlations were significant at the P< 0.001 level. Median conduction velocity was not correlated with height. Height was correlated with the distal latencies of all nerves studied (sural r = 0.6518), peroneal r = 0.4583, tibial r = 0.7217, median (r = 0.5440). These correlations were significant at the P < 0.001 level. Age was inversely correlated with both tibial (r = −0.4071) and median (r = −0.3464) nerve conduction velocities but not with sural and peroneal conductions. There were no correlations between distal latencies and age. If the variation in conduction velocity accounted for by the linear relationship with height was removed, then age would be inversely correlated to all conduction velocity measurements with the exception of the sural. Temperature is inversely correlated with the sural (r = −0.2233), peroneal (r = −0.2102), and tibial (r = −0.2710) distal latencies. In all instances, the effects of age and temperature were minor determinants when compared with the effects of height. Diagnostic conclusions made from nerve conduction data without correcting for height may be invalid in patients taller and shorter than normal. We believe that using normal values for nerve conductions that do not take height into account can no longer be considered an acceptable standard of practice.
Muscle fatigue unrelated to phosphocreatine and pH: An “in vivo” 31‐P NMR spectroscopy study
Authors: Le Rumeur Elisabeth , Le Moyec Laurence , Toulouse Pierre , Le Bars René , de Certaines Jacques D. 
Published: January 2005

AbstractMetabolic events were followed by 31‐P NMR spectroscopy during mechanical exhaustion of directly stimulated rat gastrocnemius. During mechanical fatigue, phosphocreatine (PCr) and pH first declined but although stimulation continued high values were recovered without mechanical recovery. Total recovery was only observed after cessation of stimulation. Partial mechanical recovery was elicited by lowering stimulation rhythm; it was accompanied by decrease in PCr to a steady–state level without pH alteration. When exhaustive exercise was induced immediately after nonexhaustive exercise, failure of mechanical function occurred without decrease in pH. Major findings were: first, during exhaustive stimulations, the greater the muscle fatigue, and the higher the PCr level at the end of stimulation. Secondly, PCr and force levels did not depend on preceding levels of PCr and pH. Thirdly, acidosis was observed transiently during the first minutes of the first exercise period. These findings strongly suggested that electrical events and/or excitation–contraction (EC) coupling play a crucial role in this type of fatigue.
Use of electrophysiologic tests to measure disease progression in ALS therapeutic trials
Authors: Kelly John J. , Thibodeau Linda , Andres Patricia L. , Finison Lorenz J. 
Published: January 2005

AbstractA battery of electrophysiologic tests was developed to assess the relative degree of lower and upper motor neuron (spasticity) deficit in a group of ALS patients enrolled in a therapeutic trial. Test results were correlated with strength in the tibialis anterior muscle as determined by measurement of maximum voluntary isometric contraction (MVIC), using strain gauge tensiometers, and were also correlated with a clinical spasticity rating scale. Patients were tested every 6 to 8 weeks over more than 1 year. Compound muscle action potential amplitude (CMAPa) from tibialis anterior correlated best with MVIC and also showed a strong linear correlation with time, as did MVIC. Other tests correlated poorly with MVIC on the average, although individual patients did show high correlations. In those patients where correlation between CMAPa and MVIC was low, MVIC did not show a high linear correlation with time and was also highly variable. This study suggests that the addition of CMAPa should be considered in ALS therapeutic trials if MVIC is not available. In addition, CMAPa can be useful in study samples where MVIC deterioration is not linear over time or is highly variable.