bluuebunny/crossref_metadata_2025_split huggingface dataset:
Limb myokymia
Authors: Albers James W. , Allen Arthur A. , Bastron James A. , Daube Jasper R. 
Published: January 2005

AbstractThirty‐eight patients with myokymic discharges localized to limb muscles on needle electromyography had various neurologic lesions, both acute and chronic. Of the 38 patients, 27 had had previous radiation therapy and the clinical diagnosis of radiation‐induced plexopathy, myelopathy, or both. For the remaining 11 patients, the diagnoses included multiple sclerosis, inflammatory polyradiculoneuropathy, ischemic neuropathy, inflammatory myopathy, and chronic disorders of the spinal cord and peripheral nerves. The clinical presentations and results of local ischemia, peripheral nerve block, and percutaneous stimulation suggest that most limb myokymic discharges arise focally at the site of a chronic peripheral nerve lesion.
The effects of diltiazem in dystrophic hamsters
Authors: Bhattacharya Syamal K. , Palmieri Genaro M. A. , Bertorini Tulio E. , Nutting David F. 
Published: January 2005

AbstractCalcium accumulates in muscles of dystrophic hamsters (DH) and patients with Duchenne muscular dystrophy. Various Ca antagonists were beneficial to the cardiomyopathy of DH, but had only minor effects on skeletal muscle. We administered a new Ca antagonist, diltiazem, 25 mg/kg/day orally to normal and dystrophic hamsters from ages 37 to 92 days. We observed a marked reduction in muscle Ca in DH treated with diltiazem: 73% in the heart, 61% in the diaphragm, and 48% in the rectus femoris. Plasma CK was significantly lower (by 37%) in treated DH, while the elevated rate of noncollagen protein synthesis in the diaphragm was not diminished. Histologically, the most important change was a reduction in Ca deposits in the heart. Diltiazem was well‐tolerated by all animals and did not modify Ca content in normal hamsters. This study suggests that diltizem may have therapeutic value in those conditions that are accompanied by excessive accumulation of Ca in tissues, such as muscular dystrophy.
Treatment of ongoing experimental myasthenia gravis with short term high dose cyclophosphamide
Authors: Pestronk Alan , Drachman Daniel B. , Adams Robert N. 
Published: January 2005

AbstractWe have treated animals with an ongoing autoimmune disease, experimental autoimmune myasthenia gravis (EAMG), using a strategy designed to eliminate the antibody‐producing cells. During well‐established EAMG, a single high doese of cyclophosphamide was given because of its known effectiveness against B‐lymphocytes. To counteract the lethal effects of the drug, the rats were “rescued” by bone marrow cell transplantation. This treatment produced a rapid and sustained fall of antibody titers against both the immunizing antigen (Torpedo acetylcholine receptor) and the autoantigen (rat acetylcholine receptor). Immunologic memory, as measured by an anamnestic response to the antigen, was partially suppressed. Cyclophosphamide treatment produced improvement in the neuromuscular defect: treated animals had, on the average, twice as many acetylcholine receptors at neuromuscular junctions compared with untreated EAMG animals. This treatment method of short‐term high doses of an immunosuppressive drug, such as cyclophosphamide, may eventually prove useful for human myasthenia gravis and other autoimmune diseases.
Virological studies in amyotrophic lateral sclerosis
Authors: Kascsak Richard J. , Carp Richard I. , Vilcek Jan T. , Donnenfeld Hyman , Bartfeld Harry 
Published: January 2005

AbstractComplement‐fixing antibody response to eleven different viruses were measured in amyotrophic lateral sclerosis (ALS) patients, contacts of ALS patients, neurological controls, and normal controls. The normal controls showed a decreased response to adeno‐associated virus and an increased response to adenovirus when compared to the other groups. Levels of interferon‐like substances also were investigated in sera and cerebrospinal fluids of ALS patients and neurological controls. Responses were of a low titer and were not increased in the ALS group. Explant cultures were established from tissues of 24 ALS autopsy cases. Cultures were investigated directly or following fusion to various indicator cell lines for viral‐like agents. Techniques such as interference assays, 5‐bromodeoxyuridine (BudR) induction, hemadsorption, and fluorescent antibody staining failed to detect virus. By addition of helper adenovirus to primary explant cultures, adeno‐associated virus was isolated from 2 of 11 ALS cases.
Age‐related impeded regeneration of mouse minced anterior tibial muscle
Authors: Zacks Sumner I. , Sheff Michael F. 
Published: January 2005

AbstractThe effect of increasing age on the completeness of anterior tibial muscle regeneration from autotransplants of minced muscle has been studied in Swiss Webster and C57/B6J mice aged 18 to 120 days. A progressively declining capability to regenerate new myofibers was associated with a decreasing phagocytic clearance of implanted myofiber debris. Concurrently, there was decreased presumptive myoblast proliferation and new myofiber formation. The importance of age‐related host factors, including nonspecific macrophage activity, in muscle mince regeneration was demonstrated by: (1) the successful regeneration of muscle in hetero‐transplanted muscle minces from older mice implanted in younger animals and (2) the failure of muscle regeneration when the reverse experiment was performed in syngeneic animals. Heterologous striated muscle from the diaphragm regenerated in the bed of the excised anterior tibial muscle, whereas heterologous cardiac muscle failed to regenerate as expected because of the absence of satellite cells. The failure of phagocytic clearance of implanted myofiber mince and concurrent retardation of regeneration suggests a major age‐related nonimmune role of phagocytic macrophages in the early stages of regeneration of anterior tibial muscle from isotopic minced muscle implants.
Giant axonal neuropathy: An inborn error of organization of intermediate filaments
Authors: Pena Sergio D. J. 
Published: January 2005

AbstractLight microscopic examination of cultured skin fibroblasts from three patients with giant axonal neuropathy (GAN) revealed large aggregates of intermediate filaments (IF). However, electrophoretic analysis of these cells showed normal amounts of vimentin, the fibroblast IF subunit protein. The isoelectric point and peptide mapping of vimentin were identical to controls. Moreover, vimentin was synthesized and phosphorylated at a normal rate. These findings demonstrate that GAN is an inborn error of the organization of IF and suggest that the basic genetic defect in GAN does not involve primarily the IF subunit proteins.
Palmitate oxidation in human muscle: Comparison to CPT and carnitine
Authors: Shumate Jack B. , Carroll James E. , Brooke Michael H. , Choksi Rati M. 
Published: January 2005

AbstractThe evaluation of palmitate oxidation in muscle tissue may be a useful screening test for detecting defects in fatty acid metabolism in human neuromuscular disease. If the test is to be useful, it is necessary to obtain data on a wide variety of muscle illnesses for comparative purposes. We report our experience with palmitate oxidation, muscle carnitine, and carnitine palmityl transferase (CPT) activity in 148 muscle biopsies from a variety of illnesses. The efficacy of using total protein, citrate synthase, and (1‐14C) pyruvate oxidation as internal references was investigated. Palmitate oxidation was significantly less than normal (P ≤ 0.01) in Duchenne muscular dystrophy, congenital nonprogressive myopathy, congenital muscular dystrophy, malignant hyperpyrexia, and denervation, depending on the internal reference used. Muscle carnitine levels followed a similar pattern, however, CPT activity did not. The possibility of these findings being secondary to inactivity is discussed.
Acrylamide neuropathy and changes in the axonal transport and muscular content of the molecular forms of acetylcholinesterase
Authors: Couraud J. Y. , Di Giamberardino L. , Chretien M. , Souyri F. , Fardeau M. 
Published: January 2005

AbstractAcetylcholinesterase (AChE) is present in nervous and muscular tissues of normal chickens in four main molecular forms (G1, G2, G4, and A12), distinguishable by sedimentation analysis. In the sciatic nerve of acrylamidepoisoned chickens, the anterograde axonal transport of A12 AChE was reduced by 60%, and that of G4 by 21%, compared to control values, whereas the slow axoplasmic transport of G1 and G2 was unaffected. Regarding the leg muscles, only the tibialis anterior revealed dramatic alterations in the distribution of its AChE forms coinciding with a large reduction in the number of nerve endings. In acrylamide poisoning, the AChE molecular forms were considered as very sensitive markers of both axonal transport phases and of the innervation state. Our results support the hypothesis that a defect in the fast axonal transport of proteins might be involved in the degeneration process of the disease.
Unilateral calf enlargement following S1 radiculopathy
Authors: Mielke Ulrich , Ricker Kenneth , Emser Wendelin , Boxler Konstantin 
Published: January 2005

AbstractTwo cases of unilateral calf enlargement following S1 radiculopathy are reported. “True” muscular hypertrophy could be confirmed by computerized tomography of the muscle. Muscle biopsy disclosed that fiber hypertrophy exceeded grouped fiber atrophy. In one case both fiber types were involved, and in the other mostly type 1 fibers were affected. Electromyography revealed dense pseudomyotonic activity and fasciculations. These findings are discussed in view of the current literature.
Lipid composition of sarcoplasmic reticulum from mice with muscular dystrophy
Authors: Mrak Robert E. , Fleischer Sidney 
Published: January 2005

AbstractWe have recently reported on the isolation and characterization of sarcoplasmic reticulum (SR) from normal and dystrophic mice. These purified fractions were similar in functional characteristics. We now present an analysis of the lipids in our purified SR. The lipids were generally found to be similar. Most of the differences found between the two preparations were consistent with a somewhat greater surface membrane contamination in SR fractions from dystrophic mice. This was so with respect to cholesterol content and fatty acid composition. A small decrease, however, in content of phosphatidylcholine was observed in the dystrophic SR fractions. Fluorescence polarization studies using the probe 1,6‐diphenyl‐1,3,5‐hexatriene in sarcoplasmic reticulum membranes over the temperature range 3 to 38 C showed slightly greater anisotropy in the dystrophic fractions, which is also consistent with a greater contamination of this fraction by surface membrane elements (sarcolemma and transverse tubule).
T system abnormalities in differentiating skeletal fibers of dystrophic chickens
Authors: Kidd Parris M. , Yasumura Thomas 
Published: January 2005

AbstractUltrastructural T system abnormalities are common in mature skeletal fibers from dystrophic chickens, but little is known of their development. Muscle strips from dystrophic and normal chickens aged 1 day through 4 weeks were examined in ultrathin plastic sections. At hatching, triads were sparse, with no apparent abnormalities. At 1 week, triads were more common; in some dystrophic fibers the T tubules were swollen, ballooned beyond the triad, or assembled asymmetrically, with or without supernumerary (>2) junctional sarcoplasmic reticulum components. At 2 weeks, many dystrophic fibers also displayed degenerative changes, i.e., myofibrillar disintegration and cytoplasmic dispersion. At 4 weeks, when normal triad assembly was complete, T system abnormalities were widespread in dystrophic fibers. Fiber degeneration had progressed to breakdown and replacement. Thus, derangement of the T system (which parallels onset of muscle dysfunction) superimposed on triad assembly suggests that compromised excitation‐contraction coupling is an early event in the chicken dystrophy.
Plasma exchange in chronic inflammatory polyneuropathy: Evidence suggestive of a pathogenic humoral factor
Authors: Toyka Klaus V. , Augspach Regine , Wiethölter Horst , Besinger Uwe A. , Haneveld F. , Liebert Uwe G. , Heininger Kurt , Schwendemann G. , Reiners Karlheinz , Grabensee Bernd 
Published: January 2005

AbstractChronic progressive or relapsing inflammatory polyneuropathy (CRIP) can be treated effectively with immunosuppressive drugs and/or plasma exchange (PE). This report describes a patient who responded dramatically and reproducibly to PE during four successive relapses and remained in remission while on medical immunosuppression with azathioprine and corticosteroids. The clinical course was closely correlated with electrophysiologic parameters such as compound muscle action potential amplitudes and distal latencies. The purified lgG fraction of PE filtrate bound to rat and human sciatic nerve on immunohistochemistry. Furthermore, a similar staining pattern was achieved by purified Fab fragments, which was absent in all control preparations. These findings support the hypothesis that circulating plasma factors may play a role in CRIP and that one of these factors may be an IgG antibody to peripheral nerve components.
Inflammatory myopathy: A review of etiologic and pathogenetic factors
Authors: Whitaker John N. 
Published: January 2005

AbstractHuman idiopathic inflammatory myopathy is an acquired disorder with an annual incidence of two to five cases per million. A genetic influence of two to five cases per million. A genetic influence on host susceptibility may also play a role. With the marked heterogeneity of the disease one of the major challenges is to identify subsets that might share a more uniform pathogenesis and manifest a less diverse profile of clinical findings, histopathological abnormalities, and natural history. Dermatomyositis can be distinguished by clinical appearance and pathological changes, but the recognition of additional disease subsets remains very inexact. Current evidence suggests that dermatomyositis occurs as a result of a vasculopathy, but immune mechanisms involved in other categories of idiopathic inflammatory myopathy may also involve cell‐mediated immunity and possibly multiple mechanisms. Even though viral‐induced muscle inflammation occurs in humans, there is no convincing evidence for a viral cause of idiopathic inflammatory myopathy. Experimental allergic myositis may be produced by the injection of animals with skeletal muscle homogenates and complete Freund's adjuvant, but the myositogenic factor is unknown and the parallels between experimental allergic myositis and human idiopathic inflammatory myopathy are limited.
Transient paresis in myotonic syndromes: A simplified electrophysiologic approach
Authors: Streib Erich W. , Sun Sallie F. , Yarkowsky Tony 
Published: January 2005

AbstractPatients with different myotonic syndromes were evaluated for the presence of transient decrease of muscle fiber excitability. The evoked compound muscle action potential (CMAP) was recorded from the hypothenar eminence; single, supramaximal stimuli were applied to the ulnar nerve at the wrist before and after various periods of voluntary, isometric exercise of the hand muscles. A variable decline of the CMAP after exercise was present in all subjects with myotonia. The results were similar to those obtained with rapid repetitive nerve stimulation.
Myosin light chains in normal and pathological human skeletal muscles
Authors: Pons Françoise , Leger Jocelyne , Georgesco Michel , Bonnel François , Leger Jean J. 
Published: January 2005

AbstractThirty‐nine human skeletal muscle biopsies from 24 individuals were classified as normal, neuropathic, or myopathic muscle according to classical clinical observations and histopathological properties of the muscles. The content in myosin light chains (LC) of each muscle sample was analyzed by means of a new technique of polyacrylamide gel electrophoresis that gives an improved discrimination, involving isoelectrofocusing of the muscle homogenate for the first dimension and successive migration in a urea‐containing gel for the second dimension. Four different LC patterns have been observed in the normal muscles; these four patterns and three different ones have been observed in the pathological muscles. No apparent correlation exists between the myosin LC content and the histochemical fiber typing. It is concluded that the myosin LC are apparently not a useful marker to detect the normality or the pathology of human muscle.
The relationship of insulin receptors to hypokalemic periodic paralysis
Authors: Hofmann William W. , Adornato Bruce T. , Reich Harald 
Published: January 2005

AbstractSingle muscle fibers from a typical case of hypokalemic periodic paralysis (HOPP) have been found to be depolarized in all test media and to be cathodally blocked after exposure to insulin. The diseased fibers also bind more insulin and consume more oxygen than controls. The hypothesis proposed is that increased amount or affinity of insulin binding on the HOPP muscles causes continual depolarization in the presence of normally subthreshold concentrations of circulating insulin. This is because of steady effects of the hormone on passive K+ and Na+ fluxes. Additional insulin causes rapid further depolarization with paralysis. Hypokalemia follows if the insulin increment is enough to stimulate active K+ and Na+ transport.
High energy phosphate depletion in a model of defective muscle glycolysis
Authors: Brumback Roger A. , Gerst Jeffery W. , Knull Harvey R. 
Published: January 2005

AbstractAn animal model of defective muscle glycolysis can be produced by intra‐aortic injection of iodoacetate which blocks the glycolytic enzyme glyceraldehyde‐3‐phosphate dehydrogenase. The animals show exercise‐induced, electrically silent muscle cramps and postexercise rhabdomyolysis. Exercised, cramped soleus and extensor digitorum longus muscles from these animals show marked depletion of the high energy compounds adenosine triphosphate (ATP) and creatine phosphate and accumulation of fructose‐1, 6‐diphosphate. This finding supports the hypothesis that exercise‐induced muscle contracture and cell damage in disorders of muscle glycolysis/glycogenolysis are the result of depletion of high energy molecules in the muscle cells.
Stimulation by ACTH4–10 of nerve fiber regeneration following sciatic nerve crush
Authors: Bijlsma Wim A. , Jennekens Frans G. I. , Schotman Peter , Gispen Willem‐Hendrik 
Published: January 2005

AbstractThe number of newly formed myelinated nerve fibers was counted in the sciatic and tibial nerves in the rat following sciatic nerve crush. Beginning at days 8 and 14 in the sciatic and tibial nerve, respectively, the number of new myelinated fibers increased steadily and eventually exceeded the original number by 40 and 30%, respectively. This overshoot in nerve fibers was accompanied by the presence of clusters of fibers. Both the overshoot and the clusters disappeared at later stages and returned gradually to normal values within 3 months. Chronic administration of ACTH4‐10 to the animals resulted in higher numbers of new myelinated nerve fibers throughout the process of regeneration. This stimulation was most pronounced (a three‐fold increase) during the initial stages of regeneration. A higher number of myelinated nerve fibers was also observed in ACTH‐treated rats 60 and 96 days after sciatic nerve crush. No changes in diameter of the fibers could be observed. The results are discussed in terms of a stimulation of the number of outgrowing nerve fibers caused by the peptide treatment.
Two cases of adynamia episodica hereditaria: In vitro investigation of muscle cell membrane and contraction parameters
Authors: Lehmann‐Horn Frank , Rüdel Reinhardt , Ricker Kenneth , Lorković Hrvoje , Dengler Reinhard , Hopf Hanns Christian 
Published: January 2005

AbstractMembrane potentials, current–voltage relationships, and contractile parameters were studied in intact muscle cell bundles obtained from two patients with adynamia episodica hereditaria. In a normal extracellular medium, the cell membranes had resting potentials of about –80 mV and their current–voltage relationships were not significantly different from control curves. In contrast to normal muscles the afflicted cells were paralyzed in a medium having 6–10 mmol/liter potassium. The mechanisms of paralysis in the two specimens were different from each other. Many fibers from one patient were spontaneously active even in normal solution. In high potassium solution spontaneous activity was increased and the cells gradually depolarized to values at which excitatory sodium current is normally inactivated. This depolarization was connected with an increased sodium conductance and was reversed by the application of tetrodotoxin (TTX). The fibers from the other patient were not spontaneously active. In high potassium solution they were paralyzed at membrane potential values at which normal fibers would still contract. The reason for this paralysis was a reduced excitability.
Myasthenia gravis immunoglobulin augments motor neuron survival without producing muscle paralysis
Authors: Sohal G. S. , Leshner Robert T. , Swift Thomas R. 
Published: January 2005

AbstractEffects of sera or immunoglobulins from patients with acquired myasthenia gravis on motor neuron survival during critical stages of embryonic development were investigated in the trochlear nucleus–superior oblique muscle system of white Peking duck embryos. A significant increase in motor neuron survival occurred following application of myasthenia gravis sera or myasthenic immunoglobulin during the period of embryonic death of motor neurons. There was no reduction in limb or extraocular muscle movement in treated embryos. Trochlear motor neuron survival persisted after sera or immunoglobulin treatment was discontinued. The total number of muscle fibers and acetylcholine receptros were unchanged following immunoglobulin treatment. Myasthenic immunoglobulin is therefore unique in preventing motor neuron death without producing muscle paralysis and in promoting a prolonged augmentation of motor neuron survival. It is concluded that factors other than muscle activity may also control neuron survival during embryogenesis. Previous studies of myasthenic sera in muscle have shown effects only postsynaptically. This is the first demonstration that myasthenic immunoglobulin affects structures in the central nervous system.
Experimental myasthenia: Lack of correlation between the autoantibody titer and the reduction of acetylcholine‐controlled ionic channels measured at functioning endplates
Authors: Hohlfeld Reinhard , Sterz Raimund , Kalies Inge , Wekerle Hartmut , Peper Klaus 
Published: January 2005

AbstractInbred rats with experimental autoimmune myasthenia gravis (EAMG) show no correlation between the serum autoantibody (Antiacetylcholine receptor antibody) concentration and the reduction of endplate acetylcholine‐controlled ionic channels, as measured by a novel electrophysiological technique termed quantitative ionophoresis. This has implications for attempts to explain the well‐documented lack of correlation between the autoantibody titer and the clinical severity of myasthenia gravis (MG).