bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lead uptake in motor axons
Authors: Pamphlett Roger , Bayliss Alexandra 
Published: January 2005

AbstractIn an attempt to determine wheather lead (Pb) in striated muscle can be taken up by motor axon, mice were injected intramuscularly with a 5% nitrate solution, and the passage of Pb through the tissues was traced with electron mocroscopy. Thirty minutes after injection in the tibialis anterior muscle, Pb was seen at the sarcolemma and axolemma of the neuromuscular junction (NMJ) and in the adjacent sarcoplasmic reticulum (SR). Pb was also present in the axoplasm and mitochondria of terminal and preterminal motor axons. The presence of Pb was confirmed with x‐ray elemental microanalysis. The results indicate that there is a pathway for intramuscular Pb to enter terminal motor axons. This supports the hypothesis that some forms of motor neuron disease (MND) may be due to axonal uptake and retrograde transport of Pb.
Motor‐evoked responses in primary lateral sclerosis
Authors: Brown W. F. , Ebers G. C. , Hudson A. J. , Pringle C. E. , Veitch J. 
Published: January 2005

AbstractPrimary lateral sclerosis (PLS) may be distinguished on the basis of clinical and pathological features from amyotrophic lateral sclerosis (ALS). The former is featured by a much longer clinical course, exclusively upper motor neuron findings, losses of precentral pyramidal neurons, and preservation of anterior horn cells. Electrophsiological studies of 7 PLS cases have shown normal peripheral motor conduction, absent or very delayed motor‐evoked poteintials, the occasional late development of denervation activity in distal muscles, and normal somatosensory‐evoked potentials.
Major growth reduction and minor decrease in mitochondrial enzyme activity in cultured human muscle cells after exposure to zidovudine
Authors: Herzberg Nicole H. , Zorn Ina , Zwart Rob , Portegies Peter , Bolhuis Pieter A. 
Published: January 2005

AbstractZidovudine‐induced mitochondrial myopathy in AIDS patients reported recently might be due to inhibition of mitochondrial DNA polymerase γ. We investigated the effect of zidovudine on proliferation, differentiation, activity of mitochondrial‐ and nuclear‐encoded enzymes, and mitochondrial DNA (mtDNA), in cultured human muscle cells. Marked inhibition of cell proliferation was found, even in the presence of low (10 μmol/L) zidovudine concentrations. Enzyme activity of the nuclear‐encoded mitochondrial citrate synthase was not affected, and the partially mitochondrial‐encoded cytochrome c oxidase was not decreased, except only after exposure to high concentrations (5 mmol/L) zidovudine. No decrease of mtDNA content and no mtDNA deletions were found in zidovudine‐exposed muscle cells. We propose that the effect of zidovudine on muscle, seen in zidovudine‐treated AIDS patients, results mainly from decrease in proliferation of muscle cells rather than inhibition of mtDNA replication.
AAEM case report #24: Electrodiagnosis in posttraumatic syringomyelia
Authors: Little James W. , Robinson Lawrence R. 
Published: January 2005

AbstractAn adult male with C‐7 quadriplegia developed neck pain. Axillary F central latencies were prolonged, and MRI showed a syrinx extending to C‐1. After shunting, F latencies normalized. At subsequent follow‐up, a rostral syrinx persisted by magnetic resonance imaging (MRI); motor evoked potential (MEP) latencies were prolonged but F latencies were normal. Later, the syrinx was less distended by MRI, MEPs normalized, and strength improved. We discuss the electrophysiologic methods available for diagnosing and monitoring posttraumatic syringomyelia. © 1992 John Wiley & Sons, Inc.
Insulin increases amino acid transport into rat soleus motor axons
Authors: Pickett Jackson B. 
Published: January 2005

AbstractHyperosmotic neurosecrtion was used to measure basal and insulin‐stimulated amino acid and myoinosital transport into rat motor nerve terminals. L‐Alanine and α(methylamino)‐isobutyric acid (a nonmetabolizable system A‐specific analog) transport was rapid into motor nerve terminals innervating a fast‐twitch muscle, the extensor digitorum longus, and slow into motor nerve terminals innervating the soleus, a slow‐twitch muscle. A physiological concentration of insulin, 10 μU/mL, increased L‐alanine and α(methylamino)‐isobutyric acid transport into motor nerve terminals in the soleus. Large doses of insulin, 100 or 1000 μU/mL, had no effect on L‐alanine or α(methylamino)‐isobutyric acid transport into nerve terminals in the extensor digitorum longus. There was negligible basal or insulin‐stimulated transport of D‐alanine or myoinsitol into nerve terminals of the soleus or extensor digitorum longus. These studies show that insulin regulates sterospecific amino acid transport into extensor digitorum longus motor axons. Differences in basal and insulin‐stimulated tranpsort suggest that motor axons differ in their metabolism, and might be selectively vulnerable to disease processes.
Muscle fiber conduction velocity and mean power spectrum frequency in neuromuscular disorders and in fatigue
Authors: Yaar Israel , Niles Les 
Published: January 2005

AbstractThis study investigated the relation of muscle fiber conduction velocity (MFCV) to difference power spectrum mean frequency (MF), their fatigue trends, and differences between their values and their fatigue trends in various neuromuscular disorders. Electromyographic interference pattern was recorded inside the biceps in continuous isometric maximal voluntary contractions. Each subject was encouraged to pull for as long as possible. Fatigue was calculated as percent of time to complete inability to sustain contraction. The MFCV was computed by cross‐correlation. The MF was computed by differencing, windowing, FFT, squaring of coefficient, and repeat averaging. There were 33 healthy, 86 polyneuropathic, 28 myasthenic, 13 myotonic, and 32 myopathic patients. Both MFCV and MF changed significantly with fatigue–the MFCV linearly, while the MF in a markedly nonlinear fashion. Both were found to be insensitive to the end stages of muscle fatigue–the MFCV did not change its slope toward complete fatigue, and the MF did not change at all beyond the 40% fatigue point. A statistically sound fatigue regression equation was derived for each, and a nonlinear equation was found to best describe their relationship. Neither MFCV nor its fatigue changes were found to be significantly different across the neuromuscular disorders. The MF, however, was found to be significantly different in some neuromuscular disorders in both its average values and fatigue trends. This study showed, in contrast to the literature, a nonlinear relationship between MFCV and MF. It also shows that neither the MFCV nor the MF had reasonable diagnostic power on its own; however, the MF was very promising to serve as an adjunct to other variables.
Familial amyloid polyneuropathy related to transthyretin Gly42 in a Japanese family
Authors: Uemichi Tomoyuki , Ueno Satoshi , Fujimura Harutoshi , Umekage Tadashi , Yorifuji Shiro , Matsuzawa Yuji , Tarui Seiichiro 
Published: January 2005

AbstractA Japanese family is described in which 6 persons showed familial amyloid polyneuropathy (FAP). Mean ages of onset were 38 for 4 males and 54 for 2 females. Three of the 6 became emaciated and died after 4 to 10 years. In 5, muscular weakness and autonomic dysfunction were the initial symptoms followed by sensory disturbances. Amyloidotic cardiomyopathy was present in 3 of the subjects. Amyloid deposits showed an immunohistological relation to transthyretin (TTR). Analysis of 1 patient's TTR gene revealed a single base change (A→G) that led to amino acid substitution (Glu42→Gly). This base change produced a new restriction site for endonuclease Cfr13 l in exon 2. Polymorphic analysis of the length of the Cfr13 l‐restriction fragment confirmed the base change, and made it possible to detect the mutant TTR Gly42 gene in the FAP subjects. Amino acid sequencing analysis showed a variant of TTR Gly42 in 1 patient's serum. © 1992 John Wiley & Sons, Inc.
Satellite cells in innervated and denervated muscles treated with clenbuterol
Authors: Maltin Charlotte A. , Delday Margaret I. 
Published: January 2005

AbstractThe sympathomimetic agent, clenbuterol, induces a muscle‐specific hypertrophy in both normal and catabolic muscle. Drug‐induced hypertrophy is not generally associated with an increase in DNA content, thus the role of satellite cells in the response of soleus muscles from weanling rats is questioned. Following simultaneous sciatic section and administration of clenbuterol, responses are similar in innervated and denervated muscles after 4 days. Increased protein accretion in treated muscles is associated with evidence of satellite cell activation, but with little evidence of division. It is speculated that satellite cell production of growth factors may play an important role in the hypertrophic action of clenbuterol, and the clinical implications of the findings are discussed. © 1992 John Wiley & Sons, Inc.
Autonomic surface potential analysis: Assessment of reproducibility and sensitivity
Authors: Hoeldtke Robert D. , Davis Karen M. , Hshieh Paul B. , Gaspar Stephen R. , Dworkin Gerald E. 
Published: January 2005

AbstractThere has been recent interest in measuring sympathetic sudomotor function by autonomic surface potential analysis. The purpose of the present study was to assess factors affecting the reproducibility of the test. We determined the within‐day and between‐day reproducibility in 24 healthy vclunteers. We used an increasing rather than a constant electrical stimulus to minimize habituation. The amplitudes were still highly variable (an average within‐day coefficient of variation in the soles of 35%). Habituation did not, however, affect the latencies of the responses, which were much more reproducible (an average within‐day coefficient of variation in the soles of 8%). Studies of between‐day reproducibility revealed that the mean amplitudes were lower on day 2 vs. day 1 (0.706 ± 0.10 vs. 0.85 ± 0.10 mV in the soles, P < 0.01) but the mean latencies were similar on the different testing days (2.09 ±.04 seconds for the soles on day 1 vs. 2.16 ±.05 seconds on day 2). We also assessed the sensitivity of surface potential analysis and report the results of testing 35 patients with far advanced autonomic neuropathy. © 1992 John Wiley & Sons, Inc.
SEPs and CNS magnetic stimulation in syringomyelia
Authors: Nogués Martin A. , Pardal Ana María , Merello Marcelo , Miguel Miguel A. 
Published: January 2005

AbstractSomatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) to transcranial and spinal stimulation from upper and lower limb muscles were elicited in 13 patients with syringomyelia. Seven had an associated Chiari type I anomaly. Diagnosis was confirmed by MRI. In 5 cases, SEPs and MEPs were performed before and after surgical treatment. Prolonged central motor conduction times or absent motor responses in upper or lower limbs were found in most patients. The greatest number of abnormalities was disclosed by measurement of CMCT followed by SEPs after tibial nerve stimulation. Two of 5 cases undergoing surgery improved clinically and showed reduction in CMCT after surgical treatment. Our study shows that MEPs were useful in the evaluation of neurophysiological status in syringomyelia patients, helping to estimate anterolateral spinal cord function.
Active muscle length reduction progressively damages soleus in hindlimb‐suspended rabbits
Authors: Sancesario Giuseppe , Massa Roberto , Anzil Archinto P. , Bernardi Giorgio 
Published: January 2005

AbstractThis study describes the morphologic changes in rabbit soleus muscle following hindlimb suspension (HS) for 1 to 4 weeks (group A); or following HS with hindfeet passively dorsiflexed, by means of an elastic band, for 1 to 2 weeks (group B). In the latter, elastic band use allowed phasic contractions of foot extensor muscles against resistance and prevented 35% chronic soleus shortening, which occurred in group A animals. In group A, the soleus revealed progressive muscle atrophy and myofibrillar damage. Myofibrils underwent dissolution, muscle regeneration was ineffective, and adipose tissue developed from about 2‐week suspension onward. Conversely, passive dorsiflexon of unloaded hindfeet was essential in maintaining mass and structural muscle integrity in the soleus of group B. It is hereby demonstrated that HS‐induced soleus damage in the rabbit is progressive, and can be prevented, avoiding long‐term shortening of soleus and its phasic unloaded contractions, Soleus sensitivity to unloading conditions, such as HS, tenotomy, and hypogravity, may depend on the particular physiology of this tonic antigravity muscle, engaged mainly in developing long‐lasting isometric contractions in a strectched lenth. © 1992 John Wiley & Sons, Inc.
Improvement of the exercise test after therapy in thyrotoxic periodic paralysis
Authors: Jackson Carlayne E. , Barohn Richard J. 
Published: January 2005

AbstractThe diagnosis of periodic paralysis (PP) can be aided by demonstrating a decrease in compound motor action potential (CMAP) amplitude after several minutes of exercise. We report a case of secondary hypokalemic PP due to thyrotoxicosis in which the decrease in the CMAP amplitude after exercise dramatically improved after treatment, when a euthyroid state was achieved. The exercise test is a useful electropghysiologic means of monitoring the neuromuscular status of patients with thyrotoxic periodic paralysis prior to, and after treatment of the thyrotoxicosis.
AAEM minimonograph #13: H reflexes and F waves: Physiology and clinical indications
Authors: Fisher Morris A. 
Published: January 2005

AbstractMotoneurons can be activated both reflexly and antidromically following electrical stimulation of peripheral nerves. These H reflexes and F waves are clinically useful responses which interface at the level of the peripheral nerves and the spinal cord. Because these responses are commonly employed in the electrodiagnostic evaluation of patients, an understanding of their physiology and clinical applications is important. These are reviewed. Reasoning from the physiology, both the value and limitations of H‐reflex and F‐wave studies are considered for disorders of peripheral nerves, roots, and the central nervous system. Theoretical concepts about the physiology and pathophysiology of the nervous system based on H‐reflex and F‐wave data are also discussed. © 1992 John Wiley & Sons, Inc.
Surface EMG in the recording of fasciculations
Authors: Howard Robin S. , Murray Nicholas M. F. 
Published: January 2005

AbstractThe usefulness of multichannel surface recording of fasciculations was evaluated by a retrospective study of 116 patients with various neurological disorders. Eight channels of a conventional electroencephalograph were used with plate electrode recordings from the upper arms and legs. Widespread fasciculations (defined as five or more of the eight muscle groups) were recorded in 48 of 54 patients with motor neuron disease, spinal muscular atrophy or postpolio syndrome, but noted on routine clinical examination at presentation in only 6. Eleven of 23 patients with peripheral neuropathy or myelopathy had fasciculations in five or more leads compared to one clinically, and 3 of 39 with other neurological diseases had fasciculations electrically but in only one were they clincally observed. The method is a noninvasive and sensitive adjunct to clinical examination for detecting fasciculations. Its diagnostic value is limited by the relatively high incidence of fasciculations in neuropathies and myelopathies. However, this study suggests that “false negatives” are rare and that the diagnosis of motor neuron disease should be reconsidered when less than five leads shows fasciculations. © 1992 John Wiley & Sons, Inc.
Lumbrical and interossei recording in carpal tunnel syndrome
Authors: Preston David C. , Logigian Eric L. 
Published: January 2005

AbstractMedian motor studies are commonly “normal” in mild carpal tunnel syndrome (CTS). This reflects either the sparing of motor compared to sensory fibers, or the inability of conventional studies to detect an abnormality. A novel approach to demonstrate early motor fiber involvement in CTS is the placement of the same active electrode lateral to the third metacarpal, allowing recording from the second lumbrical or the deeper interossei, when stimulating the median or ulnar nerves at the wrist, respectively. We compared the difference between these latencies in 51 normal control hands to 107 consecutive patient hands referred with symptoms and signs suggestive of CTS, who were subsequently proven to have electrophysiologic CTS by standard nerve conduction criteria. A prolonged lumbrical—interossei latency difference ( > 0.4 ms) was found to be a sensitive indicator of CTS in all patient groups. It was also helpful in patients with coexistent polyneuropathy, where localization at the wrist was otherwise difficult. © 1992 John Wiley & Sons, Inc.
Differential effects of amitriptyline on sudomotor, cardiovagal, and adrenergic function in human subjects
Authors: Low Phillip A. , Opfer‐Gehrking Tonette L. 
Published: January 2005

AbstractTricyclic antidepressants, especially amitriptyline (AMI), are widely used by patients who require tests of autonomic function. AMI effects autonomic function, but its quantitative and differential effects are not known. We prospectively evaluated the effect of AMI on sudomotor (M3 receptor), cardiovagal (M2) and adrenergic functions in 6 subjects, aged 20‐40 years before, during, and 48 hours after AMI 75 mg/d. M3 receptor function was evaluated using QSART (quantitative sudomotor axon reflex test) recordings from four sites, M2 receptor function from cardiovagal studies [HR response to deep breathing (HRDB) and the Valsalva ratio (VR)], and adrenergic function from an analysis of beat‐to‐beat BP responses to tilt and the Valsalva maneuver. Plasma AMI was determined from blood samples obtained within 2 hours of autonomic testing. QSART volume was reduced by 47% by AMI (P = 0.01), and recovered to 81% of baseline following a 48‐hour washout. HRDB was unaffected by AMI (P > 0.05). VR was increased by 10% (NS) with AMI and by 14% (P ≤ 0.05) with washout. The percent change in hemodynamic parameters by AMI were: orthostatic reduction in SBP, 62% (NS); orthostatic HR increment, 66%, (P = 0.03); and phase IIe SBP decrement, 665%, (P = 0.02). We conclude that AMI in the moderate doses used, resulted in greater inhibition of M3 than M2 receptors. The BP, HR, and beat‐to‐beat BP alterations likely reflect adrenergic inhibition resulting in a reduction in effective plasma volume. A washout of 48 hours is adequate for muscarinic but not adrenoreceptors. © 1992 John Wiley & Sons, Inc.
The silent period in pure sensory neuronopathy
Authors: Leis A. Arturo , Kofler Markus , Ross Mark A. 
Published: January 2005

Abstract“Normal” electromyographic silent periods (SPs), produced by electrical stimulation of digital nerves, were recorded in the voluntarily contracting abductor pollicis brevis (APB) muscle of a patient with pure sensory neuronopathy and absent sensory nerve action potentials (SNAPs). Such findings implicate the smaller, slower conducting fibers in the genesis of the cutaneous silent period. These same fibers may be activated during more proximal stimulation to contribute to the latter portions of the mixed nerve silent period. © 1992 John Wiley & Sons, Inc.
Effect of caffeine and high potassium on normal and dystrophic mouse EDL muscles at various developmental stages
Authors: Dangain Josette , Neering Ian R. 
Published: January 2005

AbstractEDL muscles from normal and dystrophic (dy2j) mice of various ages were examined. Muscles were divided into three groups according to age: 7 to 14 days postnatal, 16 to 21 days postnatal, and 6 months old, to assess age and/or phenotype related differences in the muscle response to caffeine or high K+. The response of normal muscles to caffeine decreased with age and reached adult characteristics between the second and third week of postnatal life. Their response to high K+ also changed during post‐natal development; specifically, the time taken to recover to 50% pretest twitch tension decreased with age, probably reflecting developmental changes in Cl− conductance. Up to 21 days of age, the sensitivity of dystrophic muscles to both caffeine and high K+ was essentially similar to normal, while marked differences were observed in the adult. Taken altogether, our results suggest that while the maturation of a number of systems might be delayed in dystrophic muscles at preclinical stages of the disease, their e–c coupling and SR function (Ca2+ release and reuptake) appear to be quite normal. Our results further suggest that the “abnormal” responses of dystrophic muscles at more advanced stages of the disease, when challenged by drugs acting on either of these systems, may be explained in terms of changes in muscle fiber type proportions. © 1993 John Wiley & Sons, Inc.
Progressive unilateral hypertrophic myopathy: A case study
Authors: Pihko Helena , Lehtinen Ilkka , Tikkanen Heikki , Härkönen Matti , Rapola Juhani , Lamminen Antti , Sahlman Antero , Somer Hannu 
Published: January 2005

AbstractA 12‐year‐old girl had progressive unilateral muscle hypertrophy limited to the sole, tibialis anterior, and biceps femoris muscles. The affected muscles showed complex repetitive discharges by electromyography, necrosis and variation of fiber size upon histopathological examination, and increased metabolic activity in biochemical studies. The findings suggest a myopathic origin, but the actual cause remains unknown. © 1993 John Wiley & Sons, Inc.
HTLV‐1 in acquired adult myopathy
Authors: Dickoff David J. , Simpson David M. , Wiley Clayton A. , Mendelson Stuart G. , Farraye Joseph , Wolfe David E. , Wachsman William 
Published: January 2005

AbstractWe report a 53‐year‐old Jamaican man with 20 years of progressing weakness involving proximal limb muscles and neck flexors. Serum CK was 1100 IU/L. EMG demonstrated spontaneous activity, myopathic motor units, and full recruitment patterns in weak muscles. Muscle biopsy revealed marked myofiber degeneration with extensive fibrosis, suggesting a chronic myopathic process. HTLV‐1 antibody was present in serum in high titers by ELISA and Western blot. Immunohistochemistry with rabbit polyclonal antisera to HTLV‐1 showed rare staining myocytes. PCR demonstrated HTLV‐1 DNA in frozen muscle tissue. This myopathy, associated with HTLV‐1 infection, has clincal and pathological features similar to a dystrophy. We recommend serological screening for HTLV‐1 in cryptogenic adult myopathies. © 1993 John Wiley & Sons, Inc.
Acoustic myography compared to electromyography during isometric fatigue and recovery
Authors: Rodriquez Arthur A. , Agre James C. , Knudtson Eileen R. , Cota  , Franke Todd M. , Ng Alexander V. 
Published: January 2005

AbstractThis study compared the acoustic (RMS‐AMG) to electromyographic (RMS‐EMG) signal, median frequency of EMG power spectrum (Fm), and quadriceps torque during isometric fatiguing contraction (FC) and recovery. Seven subjects were tested for strength (MVC) and then, on separate days, maintained 20%, 40%, or 80% MVC to exhaustion followed by MVC testing at regular intervals. Throughout FC, RMS‐EMG significantly (P < 0.05) increased and Fm significantly (P < 0.05) decreased during all trials; RMS‐AMG significantly (P < 0.05) increased only during the 20% and 40% trials. During recovery, MVC and RMS‐EMG recovered most slowly after the 20% trial and most rapidly after the 80% trial; Fm and RMS‐AMG recovered by 90 seconds after all trials. RMS‐AMG reflects RMS‐EMG during low but not high levels of FC. Recovery of strength is most depressed following FC at lower relative levels of torque. We conclude that RMS‐AMG behaves differently than RMS‐EMG, torque, and Fm during FC and recovery. © 1993 John Wiley & Sons, Inc.