bluuebunny/crossref_metadata_2025_split huggingface dataset:
Usefulness of chromosome 19 RFLP haplotypes in the diagnosis of myotonic dystrophy
Authors: Nokelainen Pekka T. , Alanen‐Kurki Leena , Somer Hannu V. K. , Pihko S. Helena , Peltonen Leena 
Published: January 2005

AbstractThree DNA probes (APOC2, PSC11, and LDR152) detecting RFLP polymorphisms were used to test the usefulness of the RFLP approach in myotonic dystrophy (MD) families from the isolated Finnish population. The informativeness of these polymorphisms did not differ from that reported in more mixed populations: in the 13 families of the study most of the 79 meiotic events studied were informative. One known recombinant is included in the study. The highest lod score obtained in the multilocus linkage analysis was z = 5.941 at recombination fraction θ = 0.02. The RFLP results significantly facilitated genetic counseling in problematic cases among the families studied. Although evidence could be found for linkage disequilibrium of the RFLP haplotypes formed in Finnish MD patients, our results do not exclude the possible existence of more than one ancient MD mutation in this population.
Slowly conducting myelinated fibers in peripheral neuropathy
Authors: Shefner Jeremy M. , Buchthal Fritz , Krarup Christian 
Published: January 2005

AbstractThe main component of the compound sensory action potential reflects the activity of large myelinated sensory fibers with diameters of greater than 9 μm. By recording the averaged potential using a needle electrode placed close to the nerve, small late components can be measured. The latency of these late components can be used to calculate minimum conduction velocity (CV); in normal subjects, average minimum CV is 15 m/s, correspending to conduction in fibers of about 4 μm in diameter. Minimum CV was measured in median, ulnar, and sural nerves of 187 patients with mild to severe neuropathic symptoms. A reduction in minimum CV was a sensitive measure of peripheral nerve dysfunction, often showing abnormalities when measures derived from the main component were normal. Patients with isolated abnormalities in minimum CV tended to have neuropathic symptoms but no signs of neuropathy. In addition, reduced minimum conduction velocity has implications for the pathology of different types of neuropathy. Slowing conducting potentials may originate from regenerating fibers, which may be of particular relevance in patients with neuropathic pain.
“Smoothed histograms”: A visual aid for the analysis of distributions of muscle fiber areas
Authors: Lexell Jan , Taylor Charles 
Published: January 2005

AbstractThe Kernel Density Estimator (KDE) is a versatile nonparametric technique with very good theoretical properties. It is used to obtain “smoothed histograms” which allows several distributions to be presented and analyzed more easily on one graph, and direct combination into average distributions. The application of the KDE method as a visual aid for the analysis of distributions of muscle fiber areas is presented here.
AAEM minimonograph #36: Basic concepts of electricity and electronics in clinical electromyography
Authors: Barry Daniel T. 
Published: January 2005

AbstractFundamental principals of electricity provide a basis for understanding the design and operation of electromyography equipment. An intuitive and quantitative explanation of charge, voltage, current, and impedance provides an introduction to the concepts of resistance, capacitance, and input impedance. These concepts form the basis for discussion of filters, amplifiers, electrodes, digital electronics, stimulators, and patient safety. The monograph assumes no specialized training in engineering or mathematics. The topics are discussed at an introductory level to provide understanding for readers with no electronics background and intuitive insight for more experienced readers.
Muscle histology in becker muscular dystrophy
Authors: Kaido Misako , Arahata Kiichi , Hoffman Eric P. , Nonaka Ikuya , Sugita Hideo 
Published: January 2005

AbstractTwenty patients with Becker muscular dystrophy (BMD), confirmed by dystrophin tests, were studied histologically. There were several morphological differences between younger (≤15‐year‐old) and older (>15‐year‐old) patients. In the younger patients, active muscle fiber necrosis followed by a regenerating process was conspicuous. In the older patients, the active degenerative changes appeared less prominent and, instead, more chronic myopathic changes such as moth‐eaten fibers, fiber splitting, and hypertrophic fibers were evident. These age‐dependent differences in the pathology of BMD were irrespective of the duration of clinical symptoms, i.e., BMD patients of a similar age showed a similar morphological feature regardless of age at onset. Although the presence of mild fiber type grouping and some small angulated atrophic fibers suggested a certain degree of neurogenic involvement, none of biopsies showed significant grouped atrophy as seen in neuropathic disorders. There was no correlation between the histological changes and the specific dystrophin abnormality.
Martin‐Gruber anastomosis and unusual sensory innervation of the fingers: Report of a case
Authors: Valls‐Sole Josep 
Published: January 2005

AbstractWe report the electrophysiological study of a patient with carpal tunnel syndrome who, besides the features of median nerve entrapment at the wrist, showed an aberrant motor innervation of Martin‐Gruber type and an unusual distribution of the sensory innervation of the fingers. Studies based on collision between sensory volleys showed that the fibers supplying the anomalous innervation did not follow the same path as the aberrant motor fibers. This finding is consistent with the hypothesis that Martin‐Gruber anastomosis is made up of motor axons only, and supports the idea that other abnormalities of innervation may be found in patients with Martin‐Gruber anastomosis.
Maximal and minimal motor nerve conduction velocities in patients with motor neuron diseases: Correlation with age of onset and duration of illness
Authors: Iijima Masakazu , Arasaki Keisuke , Iwamoto Hiroyuki , Nakanishi Takao 
Published: January 2005

AbstractWe measured the maximal and minimal motor nerve conduction velocities of the ulnar nerve in 17 patients with spinal muscular atrophy (SMA), 27 patients with amyotrophic lateral sclerosis (ALS), and 40 age‐matched control subjects. Crude values of the maximal and minimal motor nerve conduction velocities were reduced in both patient groups, but their difference in each patient was not statistically different from that of a control subject. The conduction velocities adjusted according to each patient's age were faster in SMA patients than in ALS patients. Among patients with either ALS or SMA, the age‐adjusted conduction velocities were larger in those who had developed the disease at younger ages and suffered from it for shorter periods of time. These findings suggest that the motor nerve fibers regenerate more in younger patients in the early stages of the disease, particularly in SMA.
Autosomal recessive duchenne like muscular dystrophy: Molecular and histochemical results
Authors: McGuire Stephen A. , Fischbeck Kenneth H. 
Published: January 2005

AbstractAn autosomal recessive disorder which mimics Duchenne muscular dystrophy has long been suspected as a cause of muscular dystrophy in karyotypically normal girls and in both boys and girls with consanguineous parents. Analysis of dystrophin now allows confirmation of the existence of this disorder. We report the results of this analysis in a brother and sister who have the typical clinical features of Duchenne muscular dystrophy, but no demonstrable abnormality in dystrophin or its gene.
Invited review: Autonomic dysfunction in peripheral nerve disease
Authors: McLeod James G. 
Published: January 2005

AbstractThe autonomic nervous system is affected, in most peripheral neuropathies. but only in a small number of conditions, such as diabetes, amyloidosis, Guillain‐Barré syndrome, porphyria, and familiar dysautonomia, is autonomic dysfunction of clinical importance. The pathological changes in the peripheral autonomic nervous system are similar to those in the peripheral somatic nerves. Autonomic disturbances are most likely to occur when there is acute demyelination or damage to small myelinated and unmyelinated fibers. Autonomic investigations should include tests of both sympathetic and parasympathetic function. Treatment consists of management of the underlying cause of peripheral neuropathy, physical and pharmacological measures.
Far‐field potentials in circular volumes: Evidence to support the leading/trailing dipole model
Authors: Dumitru Daniel , King John C. 
Published: January 2005

AbstractThe leading/trailing dipole model explains the production of far‐field potentials as an asymmetry in the leading and trailing dipole moments of a propagating action potential detected by a referential montage. This investigation documents the production of far‐field potentials produced by a pure dipole generator in a circular volume conductor. Multiple equipotential waveforms are recorded in an adjoining circular volume conductor attached to the one in which the dipole generator is located. This finding substantiates the “wick electrode” effect that explains the equipotential and instantaneous distribution of far‐field potentials over relatively large distances in volume conductors. The present findings support a number of the leading/trailing dipole model proposals which explain far‐field potential generation.
Fatigue‐related changes in motor unit action potentials of adult cats
Authors: Enoka Roger M. , Trayanova Natalia , Laouris Yiannakis , Bevan Leslie , Reinking Robert M. , Stuart Douglas G. 
Published: January 2005

AbstractThe purpose of this study was to quantify the changes in motor‐unit action potentials (MUAP) and force during a standard motor‐unit fatigue test. MUAP waveforms were characterized by the measurement of amplitude, duration, area, and shape (as reflected in a coefficient of proportionality). Fatigue‐resistant motor units exhibited small, but statistically significant, changes in MUAP amplitude and area during the fatigue test, whereas fatigable motor units displayed variable changes in MUAP amplitude, duration, and area. For all motor‐unit types, the coefficient of proportionality did not change, and hence the change in MUAP area was proportional to the combined changes in amplitude and duration. The between‐ and withintrain changes in MUAP were also distinct for the fatigue‐resistant and fatigable motor units. Although several mechanisms could be responsible for the changes in the MUAP as the fatigue test proceeded, the dissociation of the time courses for MUAP and force indicated that these MUAP changes were not the principal reason for the decline in force under these conditions.
Fiber density in acute and chronic inflammatory demyelinating polyneuropathy
Authors: Gantayat Maya , Swash Michael , Schwartz Martin S. 
Published: January 2005

AbstractThe fiber density in the deltoid, extensor digitorum communis, and first dorsal interosseous muscles was measured using SFEMG in 11 patients with acute and chronic inflammatory demyelinating polyneuropathy. The fiber density was increased in 58% of the muscles studied. The deltoid muscle was the most abnormal of the 3 muscles studied. There was no correlation with the clinical syndrome, with conduction block or slowed motor conduction, or with the distribution of weakness. Changes were noted even in patients studied within 3 weeks of presentation, suggesting that reinnervation begins soon after the onset of the disease.
Denervation increases clenbuterol sensitivity in muscle from young rats
Authors: Maltin Charlotte A. , Delday Margaret I. , Hay Susan M. , Baillie Andrew G. S. 
Published: January 2005

AbstractClenbuterol has been shown to ameliorate denervation‐induced atrophy and, therefore, clearly has therapeutic potential in the treatment of muscle wasting conditions in man. Previous studies have used dosages in rats which would be unacceptable in clinical practice, but the present results show that denervated muscle has a greater sensitivity to the drug than innervated or cardiac muscle. Fiber hypertrophy and an increase in protein and RNA content could be observed in denervated muscles but not in innervated muscles at a dose of 10 μg/kg body weight. When considered on a metabolic body weight basis, the effective dose in rats and the "safe" dose in man are surprisingly comparable. The observations imply that there is good reason to suppose that clenbuterol could be effective in ameliorating similar wasting conditions in man.
Lack of anionic phospholipid calcium binding sites in duchenne muscular dystrophy
Authors: Moggio Maurizio , Fagiolari Gigliola , Prelle Alessandro , Gallanti Andrea , Sciacco Monica , Scarlato Guglielmo 
Published: January 2005

AbstractWe studied membrane ultrastructural localization of anionic phospholipids (AP) and sialic acid (SA) calcium binding sites in muscle biopsies from Duchenne muscular dystrophy (DMD) and 3 Becker's muscular dystrophy (BMD) patients using polymyxin B (PXB) and limulus polyphemus (LP) as cytochemical markers. We found that AP calcium binding sites are lacking at muscle cell surface in all DMD muscle tissues, in both intact and degenerating muscle fibers. In BMD, AP have an unusual distribution along plasma membrane. Sialic acid calcium binding sites have the same localization along plasma membrane and basal lamina in DMD, BMD, and control muscles. The absence or alterations of structures involved in calcium binding in DMD and BMD may alter membrane calcium permeability, leading to abnormal Ca2+ influx into cells causing muscle necrosis.
Improved techniques for measuring muscle fiber conduction velocity
Authors: Yaar Isreal , Niles Les 
Published: January 2005

AbstractCross‐correlation (CCT) and dip analysis (DAT) are accpeted techniques for estimating muscle fiber conduction velocity (MFCV). In the DAT, the product of the power spectrum of the conducted EMG times a cosine function of the MFCV is added to and inseparable from the noise power spectrum. The inclusion of the noise power is the weakness of the DAT. We propose and evaluate 2 new techniques that directly estimate the cosine function and, hence, the MFCV, avoiding the noise power: (1) The power‐modulating‐component (PMC), which equals the real part of the crosspower‐spectrum of the EMG signal divided by its magnitude; and (2) The power spectrum of the PMC (PMCP). We recorded intramuscular from 229 biceps in isometric maximum voluntary contraction. The EMG signals were analyzed by the 4 techniques, and the results were compared in pairwise design (sign‐tests and t tests) for quality and bias. The PMC surpassed the DAT (P < 0.00005); both the CCT and PMCP performed equally well and better than the DAT and the PMC (P < 0.00005). Also, the new techniques were superior with simulated EMG. In many cases only the PMCP worked. We conclude that the new techniques are valuable in supplementing the others, and most likely will enhance clinical use of MFCV estimations.
Localization of nerve depolarization with magnetic stimulation
Authors: Odderson Ib R. , Halar Eugen M. 
Published: January 2005

AbstractThe specific location on the magnetic stimulation (MS) coil that may correspond to the area of nerve depolarization has not been determined. In order to localize such and area, MS with 9‐cm and 5‐cm diameter coils was compared with conventional percutaneous electric stimulation (ES). On the 9‐cm coil the distribution of points of nerve depolarization corresponded to that quarter of the coil which was placed over and parallel to the median nerve, whereas on the 5‐cm coil, this area also extended outside the coil. The points of median nerve depolarization with MS were distributed over a distance of 7 cm on the stimulator head and was nearly identical for the 2 coil size at the wrist and elbow. Ulnar nerve costimulation was less frequent with the smaller coil at the wrist. A calculated reference point on the coil is suggested for more accurate NCV determinations.
Demyelinating polyneuropathy in eosinophilia–myalgia syndrome
Authors: Donofrio Peter D. , Stanton Constance , Miller Van S. , Oestreich Lisa , Lefkowitz David S. , Walker Francis O. , Ely E. Wesley 
Published: January 2005

AbstractEosinophilia–myalgia syndrome (EMS) is a newly recognized disorder, characterized by myalgia, weakness, scleroderma‐like changes, and eosinophilia. EMS is associated with lots of L‐tryptophan allegedly contaminated with byproducts of the manufacturing process. We describe 3 patients with EMS who presented with a severe demyelinating sensorimotor polyneuropathy. Electrodiagnostic studies revealed multifocal conduction block, slowing and temporal dispersion of motor responses, and prolonged or absent F‐responses. Despite plasmapheresis; corticosteroids; and, in 1 patient, cyclophosphamide, 2 patients died and the remaining patient experienced minimal recovery. Pathology revealed patchy perivascular infiltrates and fibrosis in the connective tissue of muscle and nerve. Autopsy of the central nervous system in 2 patients did not reveal changes unique to EMS. In addition to other organ involvement, EMS may manifest as a potentially fatal polyneuropathy, which initially appears to have prominent demyelinating features.
AAEM minimonograph #39: Digital filtering: Basic concepts and application to evoked potentials
Authors: MacCabee Paul J. , Hassan Nasser F. 
Published: January 2005

AbstractFiltering of evoked potentials has been performed in clinical laboratories using both analog and digital methods. Analog methods introduce distortion caused by nonlinear phase shift which may be quite severe. Digital methods, while avoiding distortion caused by phase shift, reveal evoked potential components which may or may not correspond to distinct singular neuranatomic generators or homogeneous neuroanatomic systems. Thus, components identified with zero phase shift digital filters at restricted bandpass must be compared with components seen in open bandpass recordings. In some specific circumstances, high‐pass filtering of short‐latency somatosensory‐evoked potentials may distinguish slow asynchronous synaptic activity from fast and synchronous synaptic, lemniscal, or axonal activity. © 1992 John Wiley & Sons, Inc.
Treatment of hemifacial spasm with botulinum toxin
Authors: Yoshimura Don M. , Aminoff Michael J. , Tami Thomas A. , Scott Alan B. 
Published: January 2005

AbstractThe effectiveness of botulinum toxin injections in 11 patients with hemifacial spasm was investigated in a prospective placebo‐controlled blinded study. The patients were treated with four sets of injections to various facial muscles, selected by clinical evaluation. Three injections were with graded doses of toxin and one was with placebo. The order of injections was random and unknown to the patients. Results were scored both subjectively by patient assessment of symptoms and objectively by blinded review of videotapes made one month after each injection. Subjective improvement occurred after 79% of injections with botulinum toxin, regardless of dose of toxin. Only 1 patient improved after placebo. Objective improvement was seen after 84% of injections with botulinum toxin. No patient showed objective improvement after placebo injection. The most frequent side effect was facial weakness, seen after 97% of injections of botulinum toxin. Facial bruising (20%), diplopia (13%), ptosis (7%), and various other mild side effects were seen less frequently. Botulinum toxin appears to be an effective and safe method of therapy for hemifacial spasm. © 1992 John Wiley & Sons, Inc.
Impaired neuromuscular transmission during partial inhibition of acetycholinest‐erase: The of stimulus‐induced antiromic backfiring in the generation of the decrement–increment phenomenon
Authors: Besser Roland , Vogt Thomas , Gutmann Ludwig , Hopf Hanns C. , Wessler Ignaz 
Published: January 2005

AbstractNeuromusuclar transmission was studied in the rat phrenic nerve–hemidiaphragm preparation with acetylcholinesterase (AChE) partially inactivated. Enzyme inhibition resulted in (1) increased single‐twitch tension of the diaphragm; (2) compound muscle action potential (CMAP) containing repetitive discharges; (3) stimulus‐induced antidromic backfiring (SIAB) seen in the phrenic nerve; and (4) repetitive nerve stimulation (RNS) eliciting a decrement—increment (D‐I) phenomenon (i.e., amplitude reduction maximal with the second CMAP). Using a high‐calcium and low‐magnesium solution, SIAB and the decrement of the second CMAP during RNS were intensified, whereas closely spaced trains and (+)‐tubocurarine (TC) abolished SIAB and simultaneously prevented the decrement of the second CMAP. Importantly, low concentrations of (+)‐TC prevented SIAB in the phrenic nerve, while the repetitive discharges of the CMAP and the increase in twitch tension remained unaffected. This observation suggests that preterminal nicotinic receptors stimulated by released acetylcholine induce SIAB, whereas postsynaptic events are less important in the generation of SIAB. SIAB, a presynaptic event, appears to be responsible for the transient impairment of the neuromuscular transmission, i.e., the D‐I phenomenon.
Dissociation of [H+] from fatigue in human muscle detected by high time resolution 31P‐NMR
Authors: Degroot Michael , Massie Barry M. , Boska Michael , Gober Joel , Miller Robert G. , Weiner Michael W. 
Published: January 2005

AbstractPrevious in vivo studies of skeletal muscle fatigue have demonstrated significant relationships between the decline of muscular force and changes in muscle metabolism. However, these studies performed measurements over relatively long time intervals or during steady state exercise, thereby obscuring rapid metabolic changes occurring at the onset of exercise and recovery. To overcome these limitations, fatigue of human calf musculature during sustained isometric foot plantar flexion was quantified continuously as the decline in maximal voluntary contraction force (MVC), while concentrations of phosphocreatine (PCr), inorganic phosphate (Pi), intracellular free hydrogen ion (H+), and monovalent phosphate (H2PO) were simultaneously measured at 2‐second intervals by 31P nuclear magnetic resonance. The first major finding was that [H+], which has been thought to be a mediator of muscle fatigue, actually declined during the first 10 seconds of exercise when force was declining and rose immediately postexercise, when force partially recovered. Second, the correlations of [H+], [H2PO] and Pi with MVC during the first minute of exercise were determined to be curvilinear and not linear as previously suggested. Furthermore, using either a linear or curvilinear regression model, [H2PO] and Pi demonstrated a closer correlation to MVC than [H+] during the first minute of exercise. Thus, these results reveal nuances in the relationships of MVC to metabolites previously undetected by low time‐resolution measurements. These findings suggest that during sustained isometric exercise, rising [H+] is not likely to be the sole mechanism of muscle fatigue and are consistent with the view that a rise of Pi or [H2PO4] is a major causation factor in force reduction. © 1993 John Wiley & Sons, Inc.