bluuebunny/crossref_metadata_2025_split huggingface dataset:
Motor and sensory neurons of the rat sural nerve: A horseradish peroxidase study
Authors: Peyronnard Jean‐Marie , Charron Louise 
Published: January 2005

AbstractNeurons of origin of the rat sural nerve were labelled with horseradish peroxidase. Dorsal root ganglionic cells were located in the L4 and L5 ganglia, and occasionally at the L6 level. Most of these sensory neurons measured under 35 μm in diameter. In keeping with previous electrophysiological studies suggesting the presence of motor fibers to plantar muscles in the rat sural nerve, motoneurons were identified at the caudal end of the L5 spinal segment, intermingled in the posterior aspect of the ventral horn with posterior tibial motor cells supplying the foot muscles. A quantitative analysis of HRP‐labelled motoneurons revealed no difference between normal (average 67) and deafferented animals (average 70), the values being only marginally lower than counts of motor axons in deafferented sural nerves (average 80).
Antagonism of botulinum toxin paralysis by low temperature
Authors: Lundh Håkan 
Published: January 2005

AbstractDecreasing the temperature from 37 C to 20 C in vitro reactivates muscle twitch in response to nerve stimulation in a muscle previously paralyzed by botulinum toxin. Transmitter release calculated as quantum content of endplate potentials has an extremely enhanced sensitivity to temperature in botulinum paralysis (Q10 about 45) compared to normal muscle blocked by high magnesium concentration (Q10 about 2). This difference is not caused by increased efficacy of the calcium mechanism of transmitter release in botulinum poisoning at low temperature, as demonstrated by unaltered calcium‐dependence of quantum content at 22 C compared to 35 C for both types of neuromuscular block. The results give exciting clues to the mode of action of botulinum toxin.
Reinnervation in duchenne muscular dystrophy
Authors: Dubrovsky Alberto , Taratuto Ana Lía 
Published: January 2005

AbstractMotor neuron abnormalities have been implicated in the pathogenesis of Duchenne muscular dystrophy. Evidence concerning the effect of injury on motor neurons of human Duchenne muscular dystrophy (DMD) is lacking. We report a DMD patient having, in addition, an obstetric paresis on his left arm. EMG and muscle histochemistry showed signs of reinnervation superimposed on myopathy in his left arm. This suggests that sprouting is preserved in DMD motor neurons and that muscle fibers retain the capability of accepting reinnervation.
Recombinant DNA strategies in genetic neurological diseases
Authors: Roses Allen D. , Pericak‐Vance Margaret A. , Yamaoka Larry H. , Stubblefield Elton , Stajich Jeffery , Vance Jeffery M. , Roses Marcia J. , Carter Donald B. 
Published: January 2005

AbstractThe application of recombinant DNA techniques applied to the study of genetic neurological diseases will play a major role in the practice of neurology in upcoming years. Strategies are now available to develop useful and relatively simple biochemical diagnostic tests for heterozygous individuals with diseases inherited as autosomal dominant traits. In addition, molecular genetic methods will lead to the delineation of the genomic mutations responsible for these diseases. This review will update the current status of research in several neurological genetic diseases including myotonic muscular dystrophy, Huntington's disease, Charcot‐Marie‐Tooth disease and Duchenne muscular dystrophy (X‐linked). An introduction and overview of the methodology is provided. Specific research strategies including random screening of libraries, chromosome walking, messenger RNA selection, and messenger RNA translation are described. These strategies are designed to provide heterozygote identification, prenatal diagnosis and gestational management, the development of rational therapies, and the understanding of the molecular basis of disease expression.
Presynaptic and postsynaptic actions of procainamide on neuromuscular transmission
Authors: Lee David C. , Kim Yong I. , Liu Humphrey H. , Johns T. R. 
Published: January 2005

AbstractProcainamide (PA), a cardiac anti‐arrhythmic agent, was applied in vitro to the rat neuromuscular junction and its effect on neuromuscular transmission was investigated using intracellular microelectrode recording techniques. Clinically relevant doses of PA produced a dosedependent decrease in the amplitude of spontaneous miniature endplate potentials (MEPPs) and a marked increase in the half‐decay time without altering MEPP frequency or resting membrane potential. The amplitude of impulse‐evoked end‐plate potentials was also reduced in a similar dose‐dependent manner, with a marked prolongation of the decaying phase. Direct quantal analysis using magnesium‐blocked preparations showed that the drug also caused a reduction in the mean number of acetylcholine quanta released per nerve impulse. This presynaptic inhibitory effect of the drug, however, contributed less to the overall blocking action than did the postsynaptic effect. The junctional effects of the drug were completely reversible, with all affected parameters returning to the control levels after washout of PA with control solution. These direct inhibitory actions on neuromuscular transmission could account for the clinical exacerbations associated with the administration of PA to patients with myasthenia gravis and other neuromuscular diseases.
Increases in myofibrillar ATPase intermediate human skeletal muscle fibers in response to endurance training
Authors: Schantz Peter , Henriksson Jan 
Published: January 2005

AbstractThe response of human muscle triceps brachii (TB) to training, which consisted of skiing with sledges 500 miles over a period of 36 days, has been investigated by means of histochemical fiber typing (myofibrillar ATPase, n = 7). Muscle biopsies were taken in the right TB during pretraining, and in the right as well as in the left TB after training. The percentage of type 2 fibers and intermediate fibers (type 2C and 1B) in the right TB decreased and increased, respectively, by 13%. The fiber type distribution in the left TB after training was very similar to that in the right TB after training. This concordance indicates that the change in fiber type distribution was a result of the training per se, and not related to any eventual effect of the biopsy‐sampling.
Changes in fiber type composition in growing muscle as a result of dynamic exercise and static overload
Authors: Watt P. W. , Goldspink G. , Ward P. S. 
Published: January 2005

AbstractThe effects of dynamic exercise (jumping) and static overload (synergist tenotomy) on rat soleus muscle were investigated during a growing phase in juvenile animals. The relative proportions of slow twitch (type 1), fast twitch (type 2a) and intermediate (type 2c) fibers were determined histochemically. The control animals, as part developmental process, lost type 2a fibers apparently by conversion to type 1 fibers via the type 2c form. Synergist tenotomy enhanced the conversion of type 2a fibers to type 2c fibers as these muscles displayed fewer type 2a fibers than control animals at the same age. In contrast, the dynamic exercise delayed the loss of type 2a fibers from the soleus. When the two exercises were combined the effects on fiber type proportions cancelled each other; this group also had a large number of type 2c fibers. This present study indicates that the activity imposed on a muscle influences the maturational development of the constituent fiber types.
The resting membrane parameters of human intercostal muscle at low, normal, and high extracellular potassium
Authors: Kwieciński Hubert , Lehmann‐Horn Frank , Rüdel Reinhardt 
Published: January 2005

AbstractMembrane parameters at the respective resting potentials in low, normal, and high extracellular potassium solutions were determined in intercostal muscle fibers from 15 patients with no known neuromuscular disease. In synthetic interstitial fluid (normal potassium concentration 3.5 mmol/liter), we found the following mean values: resting membrane potential RP = ‐−83.3 mV, space constant γLD = 2364 μm, fiber diameter d = 49.3 μm, fiber input resistance Rin = 795 KΩ, specific membrane capacitance Cm = 4.7 μF/cm2, and specific membrane resistance Rm = 5970 Ω·cm2. The specific membrane conductance was gm = 168 m̈S/cm2, 76% of it being chloride conductance, 24% being potassium conductance. The dependence of the membrane parameters on the extracellular potassium concentration followed the predictions by the constant field theory. There was no indication of active chloride transport. The resting membrane conductance decreased with temperature with a Q10 of 1.3. Excitability parameters were nearly independent of temperature between 37 and 27°C.
Drugs in muscular dystrophy of the chicken: Corticosterone ‐21‐acetate
Authors: Entrikin Richard K. , Patterson Gary T. , Wilson Barry W. 
Published: January 2005

AbstractIn a previous series of 22‐day evaluations of 31 compounds, only corticosterone‐21‐acetate (C‐21‐A) increased righting ability of genetically dystrophic chickens to a greater extent than the standard of comparison, methysergide maleate. In the present study, C‐21‐A was subjected to longer‐term trials of up to 48 days, and additional signs of the myopathy were examined. The highest doses of C‐21‐A increased righting ability for the duration of the trials, decreased the typically elevated plasma levels of creatine kinase (CK) activity by more than 80%, and improved morphology of the dystrophic pectoralis major muscle at the light microscopic level. The major adverse effect of C‐21‐A, reduction of body weight, was consistently observed at the relatively high doses needed to increase righting ability. That alone, however, could not account for increased righting ability, and plasma CK activity was decreased even at doses that did not reduce body weight. The results show that C‐21‐A is the most effective compound yet tested in this system and, perhaps more significantly, provides the first evidence that it is possible to identify compounds that improve muscle morphology in a hereditary myopathy using a short‐term, step‐wise system.
Isomyosin distribution in skeletal muscles of normal and myotonic goats
Authors: Martin Anne F. , Bryant Shirley H. , Mandel Frederic 
Published: January 2005

AbstractIsoforms of myosin were examined in hindleg muscles isolated from normal and myotonic goats. The muscles studied were the soleus, gastrocnemius, gluteus accessorius, semitendinosus, semimembranosus, and adductor. The isomyosins were analyzed by pyrophosphate polyacrylamide gel electrophoresis. The relative proportions of slow and fast myosin isoforms present were determined by densitometric scanning of Coomassie Blue‐stained gels. All muscles contained three fast myosin isoforms and either one or two slow myosin isoforms. In normal goat, the soleus and gastrocnemius, containing 70%–75% slow isomyosins, were representative of slow muscle. The semimembranosus, the semitendinosus, and the adductor, with more than 50% fast myosin, represented a predominantly fast muscle group. The gluteus accessorius, with approximately 45% fast myosin isoforms, was intermediate between the other two groups. In the myotonic goat, a consistent and significant increase in the proportion of fast isomyosins was observed for all the muscles studied. The largest change occurred in the gastrocnemius where the incremental increase in the percentage of fast isomyosins was over 30%. All the other muscles examined had incremental increases in fast isomyosin content which ranged from 16.1% to 22.0%. These results suggest that the abnormal action potential pattern of myotonia leads to a redistribution of the myosin isoforms.
Changes in terminal sprout formation in rat sternocostalis muscle during chronic intoxication with 2,5 hexanedione
Authors: Simonati Alessandro , Cavanagh John B. 
Published: January 2005

AbstractQualitative and quantitative morphological studies of the sternocostalis muscle innervation were made on rats chronically intoxicated with 2,5 hexanedione (2,5 HD) using the zinc iodide‐osmium (ZIO) technique. Two distinct phases were seen in the events at the motor endplate. First, the number of motor endplates forming spontaneous terminal sprouts was found to increase linearly with time and, from the third week onward, the sprouts appeared to become progressively elongated. This latter change was associated with the appearance of swollen axons wihtin intramuscular nerve bundles. Second, from the sixth week onward, wallerian degeneration of nerve fibers was seen and terminal sprouts began to make new arborizations on muscle fibers. By the eighth week, this occurred in as many as 66% of the rats, and collateral sprouting was also observed at this time. The occurrence of increased spontaneous terminal sprouting due to altered neuromuscular function is discussed in the light of axonal changes resulting from nerofilament accumulation following 2,5 HD intoxication.
Acetylcholine sensitivity in replicating satellite cells
Authors: Eusebi Fabrizio , Molinaro Mario 
Published: January 2005

AbstractMononucleate myogenic cells lying within skeletal muscle fiber endomysium, the so‐called satellite cells (SC), isolated from adult leg muscle of normal or dystrophic mice were studied by electrophysiological techniques. Normal SC responded to iontophoretic acetylcholine (ACh) by depolarization even during the replicative phase. Acetylcholine sensitivity increased after cell fusion. Replicating SC from dystrophic muscle did not exhibit and sensitivity to ACh, and neither did embryonic myoblasts.
An electron microscopical study of the T‐system in biopsied muscles from fukuyama type congenital muscular dystrophy
Authors: Miike Teruhisa , Ohtani Yoshinobu , Tamari Hideo , Ishitsu Takateru , Nonaka Ikuya 
Published: January 2005

AbstractThe behavior of the tubular system in muscles from six patients with Fukuyama type congenital muscular dystrophy (FCMD) was examined by electron microscopy using a lanthanum nitrate stain for a comparison with that in Duchenne muscular dystrophy (DMD). In FCMD, many fibers showed morphological changes of the T‐system as follows: aggregated tubular components forming honeycomb‐like structures, focal dilatation of T‐tubules with tangle formation, and numerous longitudinally projecting tubules, which were quite similar to those found in cases with DMD. The fibers with abnormal T‐systems occasionally showed ultrastructural characteristics of regenerating fibers, including excessive ribosome particles, immaturely organized myofibrils, and an increased number of internal nuclei and satellite cells. The present results suggested that there was no qualitative difference in the behavior of the T‐system between FCMD and DMD, and the morphological changes of the T‐system in dystrophic muscles were not primary lesions initiating myonecrosis but reflected the behavior of sarcotubular formation in the process of muscle regeneration.
Myoglobin in rat hind limb muscles after denervation and during reinnervation
Authors: Askmark Håkan , Carlson Marie , Roxin Lars‐Eric 
Published: January 2005

AbstractRadioimmunoassay of myoglobin (Mb) was performed in rat hind limb muscles after surgical denervation and during reinnervation following cryolesion of the sciatic nerve. Muscles of the contralateral leg served as controls. After resection of the sciatic nerve, decreased Mb concentrations were noted on the fourth day in the tibialis anterior, peroneus longus, and extensor digitorum longus (EDL) muscles. Thereafter, the levels increased up to the last observation on day 32. The increases in Mb levels in the tibialis anterior and EDL muscles were considerably more pronounced (305% and 324%, respectively) than in the peroneus longus and soleus muscles (148% and 137%, respectively). After cryolesion of the sciatic nerve, the Mb concentrations in the tibialis anterior, peroneus longus, and EDL muscles increased, reaching maximal values on days 16–21. The levels then decreased and normal values were observed 2 months postoperatively. The normalization of the Mb levels during reinnervation corresponded fairly well in time with the clinical recovery and neurophysiological findings observed in a previous study.
The development of central cores in both fiber types in tenotomized muscle
Authors: Baker James H. 
Published: January 2005

AbstractUsing the histochemical reaction for myosin adenosine triphosphatase (ATPase), a study of the rat soleus muscle following tenotomy was undertaken. It was demonstrated that both type 2A and 2C fibers undergo degenerative changes following tenotomy. All previous studies have stated that only type 1 fibers were affected and developed central core lesions and that type 2 fibers were somehow protected from the degenerative process. The results of this experiment illustrate that central core lesions will develop in all three fiber types (types 1, 2A, and 2C) of the soleus following tenotomy.
Treatment of refractory chronic demyelinating polyneuropathy with lymphoid irradiation
Authors: Rosenberg Neil L. , Lacy Joseph R. , Kennaugh Ralph C. , Holers V. Michael , Neville Hans E. , Kotzin Brian L. 
Published: January 2005

AbstractFour patients with refractory or poorly responsive chronic progressive demyelinating polyneuropathy (CPDP) were treated with total lymphoid irradiation (total dose, 2000 rad) in an uncontrolled feasibility study. All patients had previously failed conventional therapy for CPDP, as well as other unconventional treatments. During a follow‐up period of 7 to 12 months after total lymphoid irradiation, there was a profound and sustained suppression of the absolute lymphocyte count and in vitro lymphocyte function, as well as an increase in the ratio of Leu‐2 (suppressor/cytotoxic subset) to Leu‐3 (helper/inducer subset) T cells in the blood. Three of the four patients demonstrated improvement in distal muscle strength, and this was associated with increased functional capabilities in two patients. In contrast, no clinical improvement in sensation was noted in any patient. Nerve conduction studies showed patchy improvement in three patients. The results of this preliminary uncontrolled study indicate that radiotherapy deserves further study in the treatment of CPDP.
Polymyositis: Reduction of acetylcholine receptors in skeletal muscle
Authors: Pestronk Alan , Drachman Daniel B. 
Published: January 2005

AbstractIn polymyositis (PM), neither the precise target nor the mechanism of the attack against skeletal muscle have yet been defined. In this study, we report evidence of a pathologic process involving a membrane component of muscle, acetylcholine receptors (AChRs). Our results show that PM patients have significantly reduced AChRs at neuromuscular junctions, averaging 55% below control values (P < 0.001). Incubation of cultured mammalian muscle cells with sera from PM patients significantly reduced (P < 0.005) the number of surface AChRs and increased their rate of degradation in 7/8 cases (P < 0.005). Similar effects were produced by purified lgG from PM patients. These results demonstrate the presence in PM patients of circulating lgG with functional effects on a component of the surface membrane of skeletal muscle. They suggest that PM and myasthenia gravis may have important features in common.
Tubular aggregates: Sarcoplasmic reticulum origin, calcium storage ability, and functional implications
Authors: Salviati Giovanni , Pierobon‐Bormioli Sandra , Betto Romeo , Damiani Ernesto , Angelini Corrado , Ringel Steven P. , Salvatori Sergio , Margreth Alfredo 
Published: January 2005

AbstractMuscle biopsy specimens from three patients with an autosomal dominant myopathy and tubular aggregates in both type 1 and type 2 fibers16 were investigated for immunofluorescent staining with antibodies to sarcoplasmic reticulum (SR) Ca‐pump protein and calsequestrin and for Ca2+ loading ability. The results show that type 1 and type 2 fibers are differentially reactive to anti–ca‐pump protein lgG and similarly reactive with affinity‐purified antibody to calsequestrin, which is in agreement with earlier observations in rat skeletal muscle.8 Tubular aggregates, which are shown to be highly reactive with either kind of antibody, appear to be sites of calcium accumulation for oxalatefacilitated adenosine triphosphate (ATP) dependent Ca uptake by chemically skinned fibers and thereby increase markedly the Ca loading capacity of the affected fibers.
PC12 cells stimulate slow‐myosin light chain 2 synthesis in chick breast muscle culture
Authors: Glass Charles A. , Walker Charles , Strohman Richard C. 
Published: January 2005

AbstractSkeletal muscle fibers developing in vitro synthesize predominantly fast‐myosin light chains, with a small contribution (less than 10%) from slow‐myosin light chain 2. Muscle fibers can be cocultured with a rat adrenal pheochromocytoma‐derived nerve cell line (PC12) known to display properties similar to sympathetic neurons. PC12 cells cultured alone synthesize catecholamines and respond to nerve growth factor by synthesizing acetylcholine and extending neurite structures. They also synthesize significant amounts of acetylcholine in the presence of nonneuronal cell types, including muscle. When cocultures of skeletal muscle fibers and PC12 cells are established, the muscle cells respond with an increased level of slow light chain 2 synthesis. Myosin light chains were identified by two‐dimensional gel electrophoresis and immunoblotting with an antiserum specific to slow light chain 2.
Contractile properties of standard and nerve‐intact muscle grafts in the rat
Authors: Faulkner John A. , Carlson Bruce M. 
Published: January 2005

AbstractThe contractile properties of standard and nerve‐intact grafts of extensor digitorum longus muscles of rats were compared in vitro. Fourteen days after grafting, the time to peak tension and the half‐relaxation times of nerve‐intact grafts were shorter than those of standard grafts, but both were longer than control values. By 60 days, these variables attained normal values. At every sample period, the tetanic tensions of nerve‐intact grafts were higher than those of standard grafts. Even at the early sampling periods, the twitch‐tetanic tension ratios of nerve‐intact grafts were close to normal values, whereas those of standard grafts were higher than normal. Stabilized nerve‐intact grafts had a larger mass and greater maximum tetanic tension development than standard grafts, but were more fatigable. Compared with control EDL muscles, stable nerve‐intact grafts show no differences except for lessened fatigability, whereas standard grafts demonstrate significant functional deficits.
HLA‐DR expression, T lymphocyte phenotypes, OKM1 and OKT9 reactive cells in inflammatory myopathy
Authors: Olsson Tomas , Henriksson Karl G. , Klareskog Lars , Forsum Urban 
Published: January 2005

AbstractFrozen muscle biopsy sections from 13 patients with inflammatory myopathy and from four healthy volunteers were characterized with a double immunohistochemical staining technique, utilizing a panel of antisera to cell surface antigens. The technique enables simultaneous visualization of HLA‐DR reactive cells and other cell types, i.e., T lymphocytes. In inflammatory myopathy, large numbers of HLA‐DR reactive “macrophage/dendritic” cells were shown. Almost all other inflammatory cells and endothelial cells also expressed HLA‐DR, as did the sarcolemma in the vicinity of inflammatory foci. Large numbers of T lymphocytes were detected by αLeu‐1 antibodies. In most instances, Leu‐3a reactive T “helper” lymphocytes dominated over αLeu‐2a reactive T “suppressor/cytotoxic” lymphocytes. Many T lymphocytes of both phenotypes appeared in close contact with HLA‐DR expressing non‐T cells. OKM1 and OKT9 antibodies, labeling macrophages and “proliferating” cells, respectively, were common among inflammatory cells. The findings provides basic data that are important for the understanding of inflammatory myopathy.