bluuebunny/crossref_metadata_2025_split huggingface dataset:
X‐Irradiation improves mdx mouse muscle as a model of myofiber loss in DMD
Authors: Wakeford Susan , Watt Diana J. , Partridge Terence A. 
Published: January 2005

AbstractThe mdx mouse, although a genetic and biochemical homologue of human Duchenne muscular dystrophy (DMD), presents a comparatively mild histopathological and clinical phenotype. These differences are partially attributable to the greater efficacy of regeneration in the mdx mouse than in DMD muscle. To lessen this disparity, we have used a single dose of X‐irradiation (16 Gy) to inhibit regeneration in one leg of mdx mice. The result is an almost complete block of muscle fiber regeneration leading to progressive loss of muscle fibers and their replacement by loose connective tissue. Surviving fibers are mainly peripherally nucleated and, surprisingly, of large diameter. Thus, X‐irradiation converts mdx muscle to a model system in which the degenerative process can be studied in isolation from the complicating effect of myofiber regeneration. This system should be of use for testing methods of a leviating the myofiber degeneration which is common to mdx and DMD.
Study on the erythrocytes from myotonic dystrophy with multi‐nuclear NMR
Authors: Kuwabara Takeo , Yuasa Tatsuhiko , Ohno Takao , Yamamuro Manabu , Miyatake Tadashi 
Published: January 2005

AbstractWe have studied the water permeability through membranes, the function of the Na pump, and glucose metabolism of erythrocytes of patients with myotonic muscular dystrophy (MyD) using 1H–, 23Na, and 13C‐NMR techniques. A significant decrease in water permeability was recognized in the MyD erythrocyte membrane, and impaired Na pumping was suspected to be correlated with the former biochemical abnormalities in band III protein of MyD erythrocyte membrane. Significant acceleration of glycolysis in the erythrocyte for the first 160 minutes was also recognized in MyD: however, the production of lactate showed no difference between MyD and controls. The increased glucose uptake in MyD may be compensatory to the diminished pumping mechanism, but further information, such as inorganic phosphate permeability and the activity of the rate‐limiting enzyme of erythrocyte glycosis, is needed.
Recording characteristics of monopolar emg electrodes
Authors: Nandedkar Sanjeev D. , Sanders Donald B. 
Published: January 2005

AbstractMotor unit action potentials (MUAPs) and the electromyographic (EMG) interference pattern (IP) were recorded from the biceps muscle of 5 normal subjects using both a concentric needle (CN) and a disposable monopolar needle (MN) electrode. The MUAPs recorded by the MN electrode had higher amplitude and area and were more frequently complex than those recorded with the CN electrode. The MUAP duration and area: amplitude ratio were similar for both electrodes. Although the MN electrode had a larger recording surface, its dimensions (maximum diameter and length of the cone shaped tip) were similar to those of the CN electrode (minor and major axes of the elliptical recording tip). Based on these observations, we infer that the MN electrode may be more selective than the CN electrode, ie, the AP amplitude recorded by the MN electrode decreases faster than the AP amplitude recorded by a CN electrode when the distance of the muscle fiber from the recording electrode increases. Photomicrographs of the MN electrode after use demonstrated no evidence that the insulating material had peeled off. There was also no evidence that MUAP measurement values changed during the recordings as would be expected if the recording surface changed due to peeling of the insulating material.
Uni‐ and bipolar surface recording of human nerve responses
Authors: Winkler Tomas , Stårlberg Erik , Haas Lindsay F. 
Published: January 2005

AbstractNerve conduction studies are of great clinical value in diagnosing nerve pathology and injury. In most neurophysiological laboratories nerve conduction recordings are routinely made with surface bipolar electrodes. More rarely, needle electrodes are used. A bipolarly recorded nerve action potential (NAP) is the difference between 2 unipolar NAPs recorded from each pole of a bipolar electrode and a remote reference. The delay between the 2 separated unipolar NAPs depends on the distance between the poles and the conduction velocity (CV). When the delay between the unipolar NAPs was increased (partly through simulation), the following changes of the bipolar NAP occurred: (1) total amplitude was maximal at a certain delay but decreased if the delay was shorter or longer, (2) latencies of the first positive and the first negative peaks increased slightly until their amplitudes reached maximal values, (3) a second negative peak of increasing latency appeared with longer delays, (4) latencies of later peaks increased linearly, and (5) total area increased nonlinearly. All parameters of the bipolarly recorded NAP (except the onset of the first positive phase) changed with increasing delay. The significance of this is that if NAPs are recorded with a bipolar electrode, standard values obtained for each nerve cannot be transferred between laboratories if different interelectrode (interpolar) distances are used. Furthermore, the assumption that a fixed interelectrode distance allows comparisons between reference values and patient data is incorrect.
Segregation by modality of myelinated and unmyelinated fibers in human sensory nerve fascicles
Authors: Hallin Rolf G. , Ekedahl Rolf , Frank Ove 
Published: January 2005

AbstractThin diameter concentric needle electrodes with a small recording surface were used to explore the characteristics of neighboring fibers in sensory median nerve fascicles. Fibers which were close neighbors in the fascicle, were not randomly distributed intraneurally. Instead there was an intrafascicular segregation by modality of both myelinated and unmyelinated fibers. In addition, evidence was obtained which suggested that the contents of different Schwann cells vary. Some Schwann cell systems envelop afferent C fibers whereas others hold efferent sympathetic C axons. The results imply a modality segregation amongst both A and C fibers in human peripheral sensory nerve fascicles.
Myosin expression in hypertrophied fast twitch and slow tonic muscles of normal and dystrophic chickens
Authors: Kennedy John M. , Zak Radovan , Gao Lizhu 
Published: January 2005

AbstractDisruption of the developmental program of myosin gene expression has been reported in chicken muscular dystrophy. In the present report, the relationship between muscular dystrophy and the ability of muscle to respond to an increased work load with a transition in the myosin phenotype has been investigated. Hypertrophy of slow tonic anterior latissimus dorsi (ALD) and fast twitch patagialis (PAT) muscles was induced by overloading for 35 days and myosin expression was analyzed by electrophoresis and immunocytochemistry. Normal and dystrophic chicken ALD muscles have nearly identical proportions of SMhyphen;1 and SMhyphen;2 isomyosins and both exhibit an age‐related repression of the SMhyphen;1 isomyosin which is enhanced and accelerated by overloading. Immunocytochemistry with anti‐myosin heavy chain (MHC) antibodies demonstrates the appearance of nascent myofibers in overloaded ALD muscles from both normal and dystrophic chickens. A minor fast twitch fiber population is also identified which doubles in number with overloading in normal ALD muscles. There are only half as many fast twitch fibers in control dystrophic ALD muscles and this number does not increase with overloading. In contrast to ALD muscles, the isomyosin profile of normal and dystrophic PAT muscles is quite different. There is significantly more FMhyphen;3 and significantly less FMhyphen;1 isomyosin in the dystrophic PAT muscle. However, both normal and dystrophic PAT muscles exhibit an overload‐induced accumulation of the FMhyphen;3 isomyosin. Immunocytochemistry reveals that, unlike the normal PAT muscle, the dystrophic PAT muscle contains a population of myofibers which express slow MHCs. As in the ALD muscle, overload‐induced hypertrophy is associated with a repression of the SMhyphen;1 MHC in these fibers. Nascent myofiber formation does not occur in either normal or dystrophic overloaded PAT muscles.
Steroid‐responsive tubular aggregate myopathy
Authors: Gilchrist James M. , Ambler Mary , Agatiello Paul 
Published: January 2005

AbstractWe report a man with an acute myalgia/cramp syndrome and tubular aggregates on his muscle biopsy. He was placed on prednisone and was found to be exquisitely sensitive to the drug, with changes of only 5 mg precipitating recurrence of symptoms. He was eventually tapered off all steroids, without symptoms, and repeat biopsy showed no tubular aggregates. We recommend similar patients be given a trial of high‐dose steroids.
Electrophysiological findings in localized hypertrophic mononeuropathy
Authors: Phillips Lawrence H. , Persing John A. , Vandenberg Scott R. 
Published: January 2005

AbstractLocalized hypertrophic mononeuropathy (LHM) is a rare foccal neuropathy associated with perineurial cell proliferation due to an undefined stimulus. We report a case of LHM involving the proximal ulnar nerve in a 13‐year‐old boy. Serial clinical and electrophysiological observations were done, including intraoperative recordings directly from the nerve on two occasions. The evolution of abnormalities, as documented by electrophysiological and immunohistochemical studies, is compatible with a process of progressive thinning of myelin sheaths, culminating in axonal degeneration in later stages. Intraoperative recording of nerve action potentials was used to guide surgical management of the lesion. Ultimately, there was a good clinical and electrophysiological response to resection of the lesion and sural nerve fascicular grafting.
Inclusion body myositis with cricopharyngeus muscle involvement and severe dysphagia
Authors: Verma A. , Bradley Walter , Adesina A. M. , Sofferman R. , Pendlebury W. W. 
Published: January 2005

AbstractA patient with inclusion body myositis (IBM) is presented. Unusual aspects of this case include a myopathy of 36 years duration, severe dysphagia due to cricopharyngeus muscle dysfunction, improvement with cricopharyngeus myotomy, and a diagnostic cricopharyngeus muscle biopsy.
Analysis of inflammatory cells and complement C3 in bupivacaine‐induced myonecrosis
Authors: Orimo Satoshi , Hiyamuta Eizo , Arahata Kiichi , Sugita Hideo 
Published: January 2005

AbstractImmunohistochemical analysis of the inflammatory cells and complement C3 in the rat skeletal muscle was performed chronologically in bupivacaine‐induced myonecrosis. At 30 minutes after injection, polymorphonuclear leukocytes appeared and increased in number, with a peak value at 12 hours, while macrophages reached the highest level at 2 days. In contrast, T cells comprised only a small population. Two weeks after the injection, all types of the inflammatory cells returned to the normal level. Deposition of complement C3 was recognized at 60 minutes at the surface membrane of de erating muscle fiber. Our observation suggests the importance of both polymorphonuclear leukocytes and complement C3 in the early stage, and macrophages in the later stage of bupivacaine‐induced myonecrosis. In addition, our findings cast doubt on the pathological significance of T cells in this model.
In vivo effects of sera from Guillain‐Barré subgroups: An electrophysiological and histological study on rat nerves
Authors: Oomes Peter G. , Van Der Meché Frans G. A. , Markus‐Silvis Loes , Meulstee Jan , Kleyweg Ruud P. 
Published: January 2005

AbstractSerum from 20 patients with Guillain‐Barré syndrome (GBS), 10 healthy controls and 10 patients with recent cytomegalovirus, Epstein‐Barr virus, or Campylobacter jejuni/coli infections was injected into rat sciatic nerve. The 20 GBS patients consisted of 2 groups of 10 patients with different electrophysiological and clinical disease patterns. The main aim of the study was to investigate possible differences in humoral (auto‐)immunity between these subgroups. We found no statistically significant differences in electrophysiological or histological parameters between nerves injected with sera from the 2 GBS groups. The sera of the‐GBS groups caused significantly more compound muscle action potential reduction at 3 to 5 days postinjection than the healthy control sera. No significant difference in nerve conduction was found between nerves injected with GBS serum and serum of patients with proven infections without GBS. Histological analysis of the same nerves that were studied electrophysiologically showed no significant differences in demyelination or other histological parameters between patients and controls at 5 days postinjection. Based on the findings in this study that sera of GBS groups with important differences in disease pattern and sera of patients with proven infection but without GBS show similar in vivo effects on rat nerves, we suggest it may be more likely that these effects are caused by aspecific serum factors associated with immune‐system activation, especially by precedent infections, than by specific disease‐related factors such as anti‐myelin antibodies.
Quantitative comparison of motor unit potential parameters between monopolar and concentric needles
Authors: Chan Rai Chi , Hsu Tao Chang 
Published: January 2005

AbstractThis study quantitatively compared the simultaneous recording of the “same” motor unit potentials recorded by closely positioned concentric and monopolar needles. The motor unit potentials from the anterior tibialis of 12 young subjects were analyzed independently by both needles being connected to 2 sets of EMG‐computer combinations. Recordings of the same motor unit potentials were confirmed by triggering and averaging of the 2 sets of motor unit potentials with identical firing patterns on both EMG screens. Automatic analysis disclosed the monopolar recordings had a significantly higher mean amplitude (2.05 times), larger surface area (2.64 times), and longer duration (1.86 times) than the concentric recordings, while the mean number of phases (1.58 times) and turns (1.35 times) revealed no statistical differences. Both active recording and reference electrodes contributed to these differences.
AAEM minimonograph #37: Facial and limb myokymia
Authors: Gutmann Ludwig 
Published: January 2005

AbstractMyokymia is a clinical phenomenon associated with characteristic electromyographic activity referred to as myokymic discharges. These are spontaneously generated bursts of individual motor unit potentials with each burst recurring rhythmically or semirhythmically, usually several times per second. It involves facial muscles more commonly than those of the extremities, and is most often seen in association with Guillain‐Barré syndrome, multiple sclerosis, radiation plexopathy, pontine tumors, and timber rattlesnake envenomation. An alteration in the biochemical microenvironment of axon membranes at one of the various sites along the motor axon is the likely basis for the altered membrane excitability that underlies the myokymic discharges in most cases. The similarity of these discharges to those seen with hypocalcemic tetany, and the ability to manipulate myokymic discharges by altering serum‐ionized Ca++, suggests that decrease in the ionized Ca++ in the microenvironment of the axon may play an important role.
Effect of statistical methodology on normal limits in nerve conduction studies
Authors: Robinson Lawrence R. , Temkin Nancy R. , Fujimoto Wilfred Y. , Stolov Walter C. 
Published: January 2005

AbstractMean ± 2 standard deviations (SD), which relies on a Gaussian distribution, has traditionally been used to derive normal limits for nerve conduction studies. Our purpose was to examine skew in nerve conduction study (NCS) parameters, and to compare normal limits derived by several alternative methods. We examined 22 NCS parameters from 75 asymptomatic, nondiabetic men (controls). The coefficient of skewness (g1) was significantly positive (P < 0.10, two‐tailed test) in 5 of 8 amplitude and 6 of 8 latency measurements. Transformation reduced g1 in 19 of 22 parameters, and was optimal when g1 was closest to zero. For each measurement, ideal normal limits were defined as mean ± 2 SD of the optimally transformed data of the control subjects. The percentage of 66 diabetic subjects classified as abnormal by the raw data, but normal by the ideal normal limits, was the positive misclassification rate; while the percentage considered normal by the raw data, but abnormal by the ideal normal limits, was the negative misclassification rate. Mean ± 2 SD of the raw data produced up to 11% positive misclassifications and 12% negative misclassifications. When the range of observed values was used, up to 6% positive misclassifications and 13% negative misclassifications were found, while the 2.5 or 97.5 percentile values produced up to 10% positive misclassifications and 13% negative misclassifications. We conclude that analyses using the raw data to derive normal limits result in an unacceptable rate of misclassification. Normal limits should be derived from the mean ± 2 SD of the optimally transformed data.
Changes in nerve fiber numbers distal to a nerve repair in the rat sciatic nerve model
Authors: MacKinnon Susan E. , Dellon A. L. , O'Brien J. P. 
Published: January 2005

AbstractChanges in nerve fiber numbers distal to a nerve repair in the sciatic nerve of 48 rats were evaluated over a 1‐ to 24‐month period. The results of the morphometric evaluation in the sciatic nerve distal to the nerve repair demonstrated an increase in nerve fiber counts as early as 1 month following the nerve repair. The number of nerve fibers in the distal nerve was greatest at 3 months and did not return to normal levels until 24 months. The results of this study will influence the timing of experimental studies in which nerve fiber counts are critical for evaluation, and provides a better understanding of the clinical events occurring following nerve repair.
Aaem case report #23: Acute paralytic poliomyelitis
Authors: So Yuen T. , Olney Richard K. 
Published: January 2005

AbstractA 56‐year‐old man with acute paralytic poliomyelitis is described. The illness started with fever and diarrhea after an overseas trip, and an enterovirus other than poliovirus was isolated from the patient's stool. The onset of weakness was rapid and asymmetric, with primary involvement of the lower extremities. Nerve conduction studies revealed low amplitude motor responses after the first week, with normal results for sensory studies. Serial electromyographic studies were performed, documenting acute denervation followed later by reinnervation in the distribution of multiple segments. The clinical and electrodiagnostic features of acute poliomyelitis are reviewed.
Use of the photoplethysmographic technique to analyze the valsalva maneuver in normal man
Authors: Benarroch Eduardo E. , Opfer‐Gehrking Tonette L. , Low Phillip A. 
Published: January 2005

AbstractWe analyzed the Valsalva maneuver (VM) using a photoplethysmographic technique in 24 normal subjects. We studied the effects of test duration (range 5 to 20 seconds) and magnitude of expiratory pressure (EP, range 20 to 50 mmHg) on maximal (%Δ) and time integrated (int) changes in heart rate (HR), and mean (MAP) and pulse (PP) pressures during phases II and IV. At all EPs, there was correlation (P < 0.01) between %Δ MAP in both late phase II and phase IV and duration of the VM. The Valsalva ratio (VR) correlated with test duration only at high EPs. All responses, except the fall in MAP in early phase II and bradycardia in phase IV, correlated with EPs. The VR correlate not only with HR responses in phases II and IV but also with MAP and PP overshoot in phase IV. Correlations between maximal AP and HR changes in either phase II and IV were poor. Our study indicates that the photoplethysmographic technique allows a more rational interpretation of the VM in the clinical setting. The VR cannot be adequately interpreted without comcomitant monitoring of arterial pressure during the VM.
Quantitation of the alternate movement rate in normal and diabetic subjects
Authors: Kennedy William R. , Navarro Xavier , Stewart Nathaniel J. 
Published: January 2005

AbstractFunctional abnormalities of alternate movement rate (AMR) of finger and foot tapping were quantitated in 162 patients with diabetic neuropathy and 30 control subjects using a simple electronic device. The quantitative AMR (QAMR) averaged 29.5 ± 3.0 for finger tapping and 20.4 ± 3.7 for foot tapping in controls, and 27.5 ± 4.8 (P < 0.05) and 17.0 ± 5.6 (P < 0.005) for finger and foot, respectively, in diabetic patients. Fifty‐one patients had abnormal QAMR in the finger and 79 in the foot. The QAMR values correlated with the results of nerve conduction studies of patients. Testing for abnormalities of AMR is a useful addition to the testing of dysfunction secondary to diabetic neuropathy. It provides quantitation of a common, subject‐initiated, functional task more accurately than possible by clinical observation.
Peripheral sensory abnormalities in patients with multiple sclerosis
Authors: Shefner Jeremy M. , Carter Jonathan L. , Krarup Christian 
Published: January 2005

AbstractAlthough multiple sclerosis primarily affects myelin within the central nervous system, both pathologic and physiological studies suggest that mild deficits in peripheral nervous system myelin may be common. To evaluate this question further, we performed near nerve studies on sural nerves of 14 patients with multiple sclerosis. Peak‐to‐peak amplitude and maximum conduction velocity were normal in 9 of 14 patients, while minimum conduction velocity, or the velocity of the slowest‐conducting component of the sensory action potential, was abnormally reduced in 9 patients. In addition, the supernormal period was evaluated for patients and compared with a control sample; multiple sclerosis patients showed a significant reduction in the amplitude of supernormality. Both the reduction in minimum conduction velocity and the alteration in the supernormal period are consistent with a mild defect in peripheral myelin.
A study of motor unit structure by means of scanning EMG
Authors: Gootzen Theis H. J. M. , Vingerhoets Dick J. M. , Stegeman Dick F. 
Published: January 2005

AbstractWe used the scanning EMG technique to investigate the structure of human quadriceps muscle motor units. A group of healthy volunteers and 2 groups of patients with proven neurogenic or myogenic neuromuscular pathology have been studied. In total, 86 scans were obtained. An estimate of the motor unit territory (S) separates the 2 patient groups: the majority of territories of myogenic patients are smaller than 4 mm, whereas almost all motor unit territories of neurogenic patients are larger. However, the sizes of the pathologic units only occasionally exceed the upper and lower limits of normal units (2 to 8 mm). The myogenic scans show, on average, a much larger temporal dispersion (T) between the MUAPs within a motor unit than the normal scans. These findings are in accordance with observations with the same technique by others. For the neuropathic scans, there is a significant positive correlation between S and T, which is completely absent in myopathic scans. These observations are confronted with current morphometrical knowledge on motor unit physiology and anatomy.