bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of anticholinesterase‐induced neuromuscular transmission failure
Authors: Maselli Ricardo A. , Leung Cynthia 
Published: January 2005

AbstractTo define the underlying mechanism of neuromuscular transmission failure induced by anticholinesterases, we simultaneously performed surface recordings of compound muscle action potentials (CMAPs) and intracellular recordings of miniature end‐plate potentials (MEPPs), miniature end‐plate current (MEPCs), and end‐plate potential (EPPs) in rat diaphragms exposed in vitro to 1 × 10−4 to 2 × 10−2 mmol/L neostigmine methylsulfate. At low concentrations of neostigmine, repetitive stimulation of the phrenic nerve resulted in decrement followed by complete recuperation of CMAP amplitudes. This bimodal pattern was associated with maximal end‐plate depolarization at the beginning of the stimulation period, increased MEPP amplitudes, and prolonged time constants of MEPC decays. Higher concentrations of neostigmine resulted in a unimodal decline of amplitudes of CMAPs and EPPS, reduced MEPP amplitudes, and a double exponential time course of MEPC decays. These results indicate that low concentrations of anticholinesterases impaired neuromuscular transmission by producing transient depolarization of the end‐plate region. Higher concentrations induced desensitization and direct blockade of the end‐plate receptor channel, probably in its open conformation. © 1993 John Wiley & Soncs, Inc.
Long‐term follow‐up of patients with Duchenne muscular dystrophy receiving ventilatory support
Authors: Fukunaga Hidetoshi , Okubo Ryuichi , Moritoyo Takashi , Kawashima Nozomu , Osame Mitsuhiro 
Published: January 2005

AbstractWe, retrospectively, examined the clinical course, decline in pulmonary function, and requirements for ventilatory assistance in 54 patients with Duchenne‐type muscular dystrophy (DMD) who were followed in the muscle disease ward of the National Hospital in Kagoshima, Japan, over the past 20 years. The percentage of the predicted vital capacity (%VC) declined in relation to age and stage of disease. Most patients required assisted ventilation when the %VC fell below 10%. Twenty patients were treated with a negative pressure chest respirator. Six of these died at the mean age of 23.2 years after being on the respirator for a mean period of 18 months. Fourteen patients are surviving at a mean age of 23.5 years after being on the respirator for a mean period of 39 months. © 1993 John Wiley & Soncs, Inc.
Acute morphologic changes in orbicularis oculi muscle after doxorubicin injection into the eyelid
Authors: McLoon Linda Kirschen , Luo Xing Xing , Wirtschafter Jonathan 
Published: January 2005

AbstractThis study attempts to gain a better understanding of the primary cause of doxorubicin myotoxicity to aid in the development of a protocol to increase its effectiveness in treating muscle spasm diseases. The time course of acute injury to the orbicularis oculi muscle after injection of doxorubicin into the eyelids of rabbits was examined. The effects of doxorubicin injection were immediate and dramatic. Within 5 minutes, the muscle cells in the eyelids showed signs of myofibrillar dissolution. This process continued for the first 24 hours, with a marked decrease in the total number of myofibers by 1 hour after drug treatment. By 4 days after doxorubicin injection, most of the treated muscle had a more normal morphology, although some ongoing myofibrillar dissolution was present. There was evidence for a limited amount of muscle regeneration. Three levels of injury were seen: a severe, irreversible injury in the majority of the myofibers; a mild, reversible injury in a subset of the fibers; and a group of myofibers apparently uninjured as a result of doxorubicin treatment. Doxorubicin toxicity in skeletal muscle is of rapid onset. Understanding the primary cause and acute changes in doxorubicin myotoxicity may accelerate the development of improved protocols to increase the effectiveness of doxorubicin in treating muscle spasm diseases.
Na+ currents near and away from endplates on human fast and slow twitch muscle fibers
Authors: Ruff Robert L. , Whittlesey Diana 
Published: January 2005

AbstractFast and slow twitch muscle fibers have distinct contractile properties. Here we determined that membrane excitability also varies with fiber type. Na+ currents (INA) were studied with the loose‐patch voltage clamp technique on 29 histochemically classified human intercostal skeletal muscle fibers at the endplate border and <200 μm from the endplate (extrajunctional). Fast and slow twitch fibers showed slow inactivation of endplate border and extrajunctional INA and had increased INA at the endplate border compared to extrajunctional membrane. The voltage dependencies of INA were similar on the endplate border and extrajunctional membrane, which suggests thatboth regions have physiclogically similar channels. Fast twitch fibers had larger INA on the endplate border and extrajunctional membrane and manifest fast and slow inactivation of INA at more negative potentials than slow twitch fibers. For normal muscle, the differences between INA on fast and slow twitch fibers might: (1) enable fast twitch fibers to operate at high firing frequencies for brief periods; and (2) enable slow twitch fibers to operate at low firing frequencies for prolonged times. Disorders of skeletal membrane excitability, such as the periodic paralyses and myotonias, may impact fast and slow twitch fibers differently due to the distinctive Na+ channel properties of each fiber type. © 1993 John Wiley & Sons, Inc.
Invited Review. The potential for gene therapy in duchenne muscular dystrophy and other genetic muscle diseases
Authors: Karpati George , Acsadi Gyula 
Published: January 2005

AbstractDystrophin cDNAs have been introduced into skeletal muscle fibers of dystrophin‐deficient mice (mdx) through direct DNA injection in plasmid expression vectors and by replication‐defective recombinant adenovirus vectors. The introduced genes appear to protect those muscle fibers from necrosis in which they become expressed. By direct injection of dystrophin cDNA in plasmid expression vector, only 1–2% of adult mdx muscle fibers of the injected muscle expressed dystrophin. On the other hand, by recombinant adenovirus injection into very young mdx muscle, a better efficiency has been reported. We have discussed several putative and proven factors that may contribute to the thus far demonstrated relatively low efficiency of dystrophin gene transfer. These include poor uptake of gene constructs by muscle fibers, degradation of the injected DNA, and poor access of gene constructs to the nuclear compartment. Neutralization or elimination of these factors could improve the efficiency of gene transfer so that it might, in the future, qualify as an effective therapy for DMD and some other genetic diseases of muscle.© 1993 John Wiley & Sons, Inc.
Muscle cramp as the result of impaired gaba function—an electrophysiological and pharmacological observation
Authors: Obi T. , Mizoguchi K. , Matsuoka H. , Takatsu M. , Nishimura Y. 
Published: January 2005

AbstractWe investigated the mechanism of cramps in 2 patients: a 48‐year‐old man with bulbospinal neuronopathy, and a 46‐year‐old man with amyotrophic lateral sclerosis. Cramps were quite easily induced by volitional exertion and high‐frequency stimulation of the peripheral nerves. When an ulnar nerve was blocked with lidocaine at the elbow, no cramp was induced despite the application of high‐frequency stimulation at the wrist. Diazepam (GABAA agonist) was effective in the first patient and baclofen (GABAB agonist) in the second, with no cramps induced in spite of increasing stimulation intensity. Impairment of interneurons mediated by GABA as the neurotransmitter is thought to be involved in the mechanism of the cramps. © 1993 John Wiley & Sons, Inc.
Acetylcholine receptor subunit gene expression in thymic tissue
Authors: Kaminski Henry J. , Fenstermaker Robert A. , Abdul‐Karim Fadi W. , Clayman Julie , Ruff Robert L. 
Published: January 2005

AbstractIt is controversial whether acetylcholine receptors (AChR) or AChR‐like proteins exist in human thymus. To evaluate this question we isolated RNA from paraffin‐embedded thymic tissue of 5 myasthenics and 5 nonmyasthenics. RNA was subjected to reverse transcription followed by polymerase chain reaction (RT‐PCR) using primers specific for β‐actin, subunits of the fetal‐ and adult‐type AChR, and Myf‐4, a gene product which regulates AChR expression in muscle. β‐Actin transcripts were identified in specimens from 8 of 10 patients. In these 8 patients α‐and ε‐subunit transcripts were identified. Presence of these transcripts did not correlate with thymic pathology or clinical presentation. No γ‐subunit (specific for the fetal‐type AChR) or Myf‐4 transcripts were found. Our results indicate that mRNA for subunits of the adult‐type AChR are expressed in thymic tissue by mechanisms not involving Myf‐4. AChR subunits in pathological thymus may provide a target for immune attack in MG. However, as AChR subunits were found in thymus tissue from myasthenics and nonmyasthenics, the presence of AChR subunits in the thymus alone is not sufficient to produce myasthenia gravis. © 1993 John Wiley & Sons, Inc.
Literature review of the usefulness of nerve conduction studies and electromyography for the evaluation of patients with carpal tunnel syndrome
Authors: AAEM Quality Assurance Committee  , Jablecki Charles K. , Andary Chair Michael T. , So Yuen T. , Wilkins Dennis E. , Williams Faren H. 
Published: January 2005

AbstractThe sensitivity and specificity of nerve conduction studies (NCS's) and electromyography (EMG) for the diagnosis of carpal tunnel syndrome CTS) were evaluated by a critical review of the literature. With a search of the medical literature in English through May 1991, 165 articles were identified and reviewed on the basis of six criteria of scientific methodology. The findings of 11 articles that met all six criteria and the results of 48 additional studies that met four or five criteria are presented. We concluded that median sensory and motor NCS's are valid and reproducible clinical laboratory studies that confirm a clinical diagnosis of CTS with a high degree of sensitivity and specificity. Clinical practice recommendations are made based on a comparison of the sensitivities of the several different median nerve conduction study (NCS) techniques.
Early appearance of aging phenomenon in the interdigital nerves of the foot
Authors: Lee Kwang W. , Oh Shin J. 
Published: January 2005

AbstractTo test the hypothesis that the interdigital nerves of the foot are the first to be affected by aging, we studied sensory nerve conduction in the nerves of normal subjects between the ages of 10 and 79, using the near‐nerve needle technique. In normal individuals up to the seventh decade we could get sensory CNAPs without any difficulty by 256 averagings. In 10% of the 70–79‐year‐old group we could not obtain those potentials in some digital or interdigital nerves. Between the 10–49‐year‐old and 50–79‐year‐old groups, there was a significant slowing in the sensory NCVs, a significant decline in the amplitude of the sensory CNAPs, and a significant prolongation of the duration of sensory CNAPs for the various interdigital nerves. Thus, our study documented the earlier presence of aging phenomenon in the sensory nerve conduction of the interdigital nerves of the foot compared with the previously reported sensory nerve conduction change with age in the other nerves. We conclude that the “degeneration” of various interdigital nerves of the foot is accelerated from the early 50s on, possibly resulting from the normal aging process. © 1994 John Wiley & Sons, Inc.
Anti‐GM1 antibodies and impaired blood–nerve barrier may interfere with remyelination in multifocal motor neuropathy
Authors: Kaji Ryuji , Hirota Nobuyuki , Oka Nobuyuki , Kohara Nobuo , Watanabe Tetsuya , Nishio Takeshi , Kimura Jun 
Published: January 2005

AbstractMultifocal motor neuropathy has pure motor manifestation and nonremittent clinical courses. Antiganglioside antibodies, though variable in titers, are characteristically elevated in the majority of these patient. In our cases, pathological findings at the site of conduction block suggested impaired remyelination and disruption of blood–nerve barrier. These findings lead us to postulate that antibodies toward gangliosides or toward unknown antigens containing gangliosides initiate motorspecific demyelination. The lesion, once produced, may persist as a result of impaired remyelination caused by disrupted blood–nerve barrier. The antibodies bound to denuded axons may also interfere with a remyelinative process. If so, antibodies may not always be circulating, thus accounting for variable levels of titers. © 1994 John Wiley & Sons, Inc.
Nerve root hypertrophy in chronic inflammatory demyelinating polyneuropathy
Authors: de Silva Rajith N. , Willison Hugh J. , Doyle David , Weir Andrew I. , Hadley Donald M. , Thomas A. Myfanwy 
Published: January 2005

AbstractA patient with chronic inflammatory demyelinating polyneuropathy (ClDP) and centrel demyelinating disease is desoribed in whom striking nodular filling defects on multiple lumbar–sacral nerve roots, mimicking neurofibromata, were observed at myelography and magnetic resonance imaging. We suggest that these lesions are secondary to recurrent segmental demyelination and remyelination and that the differential diagnosis of this radiological feature should include CIDP. © 1994 John Wiley & Sons, Inc.
AAEM case report #5: Amyotrophic lateral sclerosis
Authors: Denys Eric H. 
Published: January 2005

AbstractA 40‐year‐old man presented with a gradual onset of gait unsteadiness and weakness in the arms. The stretch reflexes were normal in the upper extremities but hyperactive in the lower extremities with bilateral Babinski signs. A myelogram revealed a partial obstruction at C‐5–6. Two prior electromyograms, 7 and 5 months prior to admission, reportedly showed positive waves only in two peroneal supplied muscles. Repeat electromyographic testing demonstrated normal nerve conduction velocities and needle electrode abnormalities in upper and lower extremities as well as thoracic paraspinal muscles allowing a diagnosis of amyotrophic lateral sclerosis (ALS). The importance of electromyographic testing in clinically nonaffected areas is stressed as well as its role in patients presenting with upper motor neuron signs. It is the task of the clinical electromyographer to consider other entities in the differential diagnosis, such as a multifocal motor neuropathy with conduction blocks and design the tests accordingly. The role of electromyography in the prediction of the course of ALS by assessing the degree of reinnervation is discussed. This will become increasingly important in the design of treatment trials.
Acute necrotizing myopathy of intensive care: Electrophysiological studies
Authors: Zochodne Douglas W. , Ramsay David A. , Saly Viera , Shelley Steven , Moffatt Susan 
Published: January 2005

AbstractA series of recent reports have identified cases of a quadriplegic myopathy characterized by myofiber necrosis and loss of myosin filaments associated with the use of nondepolarizing muscle blocking agents and glucocorticoids. We report electrophysiological findings in 7 intensive care unit patients who developed evidence of an acute myopathy in association with the use of nondepolarizing muscle blocking agents. Several important features were identified: (i) a neuromuscular transmission deficit was observed in 3 patients up to 7 days following withdrawal of vecuronium; (ii) motor M potentials were of low amplitude, there was mild abnormal spontaneous activity on needle electromyography, and sensory conduction was relatively preserved; (iii) not all patients received glucocorticoids or were asthmatic; (iv) 2 patients given vecuronium had very high creatine kinase levels and developed acute renal failure associated with myoglobinuria; and (v) rises in motor M potentials accompanied clinical recovery. This complication of intensive care may be severe, but is reversible and possibly avoidable. Our findings implicate nondepolarizing muscle blocking agents in the development of the myopathy. Electrophysiological studies provide important prognostic guidance. © 1994 John Wiley & Sons, Inc.
Axonal neuropathy in eosinophilia–myalgia syndrome
Authors: Burns S. M. , Lange D. J. , Jaffe I. , Hays A. P. 
Published: January 2005

AbstractThree patients with eosinophilia–myalgia syndrome linked to consumption of L‐tryptophan supplement developed a severe sensorimotor axonal neuropathy. All three had myalgia, elevated eosinophil count, and later developed fasciitis. Neuropathy was found at all stages of the illness and resulted in disability which was irreversible despite cessation of L‐tryptophan. Nerve conduction studies showed reduced motor and sensory evoked response amplitudes with select sparing of some nerves and the arms were more involved than the legs. Cerebrospinal fluid protein content was increased in one of two patients so tested. Creatine kinase was normal and muscle biopsy showed perimysial inflammation. Sural nerve biopsy in one case showed epineural perivascular inflammation. Our data showed that a severe sensorimotor axonal neuropathy occurs in eosinophilia–myalgia syndrome, suggestive of mononeuritis multiplex. © 1994 John Wiley & Sons, Inc.
Dystrophin and dystrophin‐related protein in the brains of normal and mdx mice
Authors: Uchino Makoto , Yoshioka Kowashi , Miike Teruhisa , Tokunaga Makoto , Uyama Eiichiro , Teramoto Hitoo , Naoe Hiroaki , Ando Masayuki 
Published: January 2005

AbstractTo clarify the localization and characterization of dystrophin and dystrophin‐related protein (DRP) in the brains of normal and mdx mice, we carried out immunostaining and immunoblotting studies using four region‐specific antidystrophin and anti‐DRP antibodies. With immunostaining, punctate immunoreactivity of dystrophin was seen along the cell bodies and dendrites of the cerebral cortical neurons in the normal mice. By contrast, dystrophin was not detected at all in the brains of mdx mice. Immunoreactivity of DRP was observed in the vascular walls, pia mater, and choroid plexus of both normal and mdx brains, but not in the neuronal cells. The possible compensatory increase of DRP as seen in the skeletal muscles of mdx mice was not noted in the brains. The immunoblot findings were very consistent with those of immunostain. Although further studies of brain‐type dystrophin are necessary, it seems unlikely that DRP participates in any physiological function of the neuronal cells. © 1994 John & Sons, Inc.
Limited benefit of electrophysiological studies during dorsal rhizotomy
Authors: Pollack Michael A. 
Published: January 2005

AbstractUsing a formula for standard deviation and several assumptions, the potential benefit of electrophysiological recording (ER) during dorsal rhizotomy for cerebral palsy is calculated and expressed in a ratio, the electrophysiological recording benefit ratio (ERBR). ERBR is approximately 1.1 in most of the examples, but other factors may reduce this ratio. Severing an additional rootlet appears to be a viable alternative to ER in most of the examples. Advantages of dorsal rhizotomy without ER include reduced expense and operative time. Prospective studies are recommended to evaluate further the benefit of ER during dorsal rhizotomy. If stimulation of dorsal rootlets is abandoned during dorsal rhizotomy, stimulation of whole dorsal and ventral roots may still be necessary to prevent inadvertent severing of motor fibers. © 1994 John & Sons, Inc.
Expression of myoglobin gene in skeletal muscle of patients with neuromuscular diseases
Authors: Kawai Hisaomi , Naruo Takako , Yoneda Kenji , Masuda Kenjiro , Mitsui Takao , Nishida Yoshihiko 
Published: January 2005

AbstractExpression of the myoglobin (Mb) gene in skeletal muscle was studied in patients with Duchenne muscular dystrophy (DMD), polymyositis (PM), or amyotrophic lateral sclerosis (ALS) by measuring Mb concentration by radioimmunoassay and Mb messenger ribonucleic acid (RNA) (MbmRNA) levels by Northern blot analysis. Mb concentrations in the muscle cells (Mb/noncollagenous protein) were decreased in patients with DMD, PM, or ALS. However, while Mb concentrations per MbmRNA content (Mb/MbmRNA) were decreased in DMD and PM patients, these values were normal in ALS patients. These results suggest that Mb synthesis is increased in muscles of DMD and PM patients, but is not sufficient to compensate for the excessive loss of Mb from the affected muscles, and that the synthesis is decreased in the muscles of ALS patients. © 1994 John Wiley & Sons, Inc.
Compound sensory action potentials evoked by tactile and by electrical stimulation in normal median and sural nerves
Authors: Krarup Christian , Trojaborg W. 
Published: January 2005

AbstractThe compound sensory action potential evoked by electrical stimulation provides a measure of the number and physiological properties of myelinated fibers in the nerve but does not allow evaluation of the most distal part of the sensory nerve. This study compares the compound sensory action potential, evoked by electrical and tactile stimuli, and recorded through needle electrodes placed close to the median and sural nerves of 22 normal males aged 16–51 years. The tactile probe, with a slight preindentation, delivered an indentation of the skin of 200 μm at a rate of 400 μ/ms at the tip of digit III and the dorsolateral side of the foot. The responses were recorded from the median nerve at wrist and elbow and from the sural nerve at the lateral malleolus and midcalf. The amplitudes of the responses averaged 0.5 μV and 0.7 μV in the sural and the median nerves (P < 0.02), respectively, which was only 5–10% of the amplitude evoked by electrical stimulation. The mean maximal conduction velocity determined by tactile stimulation was 54 m/s in the sural nerve compared with 65 m/s in the median nerve and similar to that calculated after electrical stimulation. In the median nerve the sensory conduction velocity was 8% faster than the motor conduction velocity. These findings indicated that only a fraction of the fibers in the nerve were activated by the probe and that the response was conducted along large myelinated sensory fibers. The latency of the tactile response was longer than that of the electrically evoked response due to the receptor delay and conduction along thin distal fiber portions. The delay at the mechanoreceptors was about 1 ms in the sural and 0.65 ms in the median nerve (P < 0.01). © 1994 John Wiley & Sons, Inc.
Conduction velocity in motor, cutaneous afferent, and muscle afferent fibers within the same mixed nerve
Authors: Shefner Jeremy M. , Logician Eric L. 
Published: January 2005

AbstractMammalian axons subserving different functions have different conduction velocities (CV); motor fibers conduct more slowly than cutaneous fibers, which conduct slower than muscle afferents. However, human studies have yielded conflicting results. We studied isolated fiber populations in human sciatic nerve to examine further this question. Motor studies were performed in standard fashion, stimulating at gluteal fold (GF) and popliteal fossa (PF) and recording soleus. In addition, conduction velocity of a pure motor nerve volley was calculated for 3 subjects. Stimulating and recording electrodes were needles placed close to the nerve. Cutaneous afferents were studied by stimulating the sural nerve at the ankle and recording at PF and GF. Muscle afferent velocity was assessed by comparing soleus H reflex latency with stimulation at PF and GF. Results in 10 subjects showed muscle afferent CV of 57.6, cutaneous afferent CV of 55.1, motor CV of 52.4. and mixed nerve CV of 56.3 m/s. Although statistically significant, these differences are much smaller than in animal studies. These results have implications for understanding what fibers contribute to Spinal reflexes. © 1994 John Wiley & Sons, Inc.