bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of ATPase in sarcoplasmic reticulum from two strains of dystrophic mice
Authors: Neymark Michael A. , Kopacz Stephan J. , Lee Chaun‐Pu 
Published: January 2005

AbstractThe ATPase activities and phosphoenzyme levels have been determined in sarcoplasmic reticulum (SR) membranes prepared from two animal models of muscular dystrophy, myodystrophic (myd/myd) and strain 129 dystrophic (129 dy/dy) mice. In both myd/myd and 129 dy/dy SR membranes, the basal ATPase activities are elevated above control levels, while the Ca‐dependent ATPase activities are normal. The addition of 0.1% Triton X‐100 not only lowers the basal ATPase activity of myodystrophic control SR membranes by 60%, but also lowers the elevated basal ATPase activity of myd/myd SR membranes to a similar level. The Ca‐dependent ATPase activities of myodystrophic control and myd/myd SR membranes are increased approximately threefold by the addition of Triton. The addition of 0.1% Triton X‐100 lowers the basal ATPase activities of 129 control and 129 dy/dy SR membranes to similar levels, but stimulates the Ca‐dependent ATPase activity of 129 dy/dy SR membranes to a level that is only 60% of that of 129 control SR membranes. The level of phosphoenzyme intermediate is decreased approximately 15% in myd/myd SR membranes and approximately 30% in 129 dy/dy SR membranes.
Ca‐activated neutral protease and its inhibitors: In vitro effect on intact myofibrils
Authors: Sugita Hideo , Ishiura Shoichi , Suzuki Koichi , Imahori Kazutomo 
Published: January 2005

AbstractSDS gel electrophoresis of troponin and myosin extracted from chicken myofibrils pretreated with Ca‐activated neutral protease showed a pattern similar to that observed in the muscles of patients with Duchenne muscular dystrophy, that is, a decrease in troponin‐l and troponin‐C with relative preservation of troponin‐T and degradation of the heavy chain of myosin. Also, α‐actinin and troponin‐C were released from myofibrils. Two inhibitors of Ca‐activated neutral protease, leupeptin and E‐64, inhibited the degradative action of Ca‐activated neutral protease on intact myofibrils in vitro.
Peripheral neuropathy in spinocerebellar degenerations
Authors: McLeod J. G. , Evans W. A. 
Published: January 2005

AbstractNerve conduction studies have been performed in 19 subjects with hereditary spinocerebellar degenerations other than Friedreich ataxia. Clinically, they may be classified as olivopontocerebellar atrophy or cerebello‐olivary degeneration. In 9 patients, sensory conduction was abnormal, and in the whole group there was a significant impariment of sensory conduction and mild slowing of motor conduction in the lateral popliteal nerve. Sural nerve biopsies were performed on 5 patients. In 3 cases there was a mild to moderate reduction of myelinated fibers of all diameters; unmyelinated fibers were normal. In 1 patient from a kindred with a spinocerebellar degeneration in which the inheritance was autosomal dominant, neuropathological findings at autopsy confirmed the clinical diagnosis of the Menzel type of olivopontocerebellar atrophy; thee was degeneration of dorsal root ganglion and anterior horn cells as well as of myelinated fibers of all diameters in the sural nerve.
Increased rates of myofibrillar protein breakdown in muscle‐wasting diseases
Authors: Warnes Deidre M. , Thomas Frank M. , Ballard F. John 
Published: January 2005

AbstractThe excretion of endogenous creatinine and 3‐methylhistidine by subjects with muscle diseases has been measured in order to assess muscle mass and fractional rates of myofibrillar protein degradation. Increases in the rates of myofibrillar protein breakdown were observed in all subjects with Duchenne, Becker, autosomal recessive Duchenne‐like, and limb‐girdle muscular dystrophy; dystrophia myotonica; myotonia congenita; peroneal muscular atrophy; myasthenia gravis; and central core disease; in some cases of spinal muscular atrophy; but in no cases of facioscapulohumeral muscular dystrophy or dystonia musculorum deformans. All increases in myofibrillar protein breakdown were associated with reductions in muscle proportion below the normal. Muscle‐wasting diseases may respond to therapy directed towards an inhibition of muscle protease activity; the efficacy of such therapy can be monitored by the 3‐methylhistidine–to–creatinine excretion ratio.
Computed tomography of muscle
Authors: Bulcke Jan A. , Crolla Dominique , Termote Jean‐Luc , Baert Albert , Palmers Yvan , van den Bergh Raymond 
Published: January 2005

AbstractComputed tomography (CT) scans of skeletal muscles of 3 patients with pseudohypertrophic muscular dystrophy are presented. Different patterns of muscle alterations and particualrly of pseudohypertrophy are described. The significance of the radiological findings for clinical examination, electromyography, and needle biopsy is discussed.
The adaptive response of skeletal muscle to increased use
Authors: Salmons S. , Henriksson J. 
Published: January 2005

AbstractSkeletal muscle undergoes profound changes in morphological, physiological, and biochemical character when subjected to prolonged periods of increased use. Although increased use may be brought about in a variety of ways, the results show consistent features. In particular, endurance exercise and chronic stimulation differ only in degree: the properties which change in response to exercise are also those which change at an early stage of stimulation; the properties which are resistant to change under exercise conditions change only after prolonged stimulation. There is therefore a hierarchy of stability in the properties of skeletal muscle which is revealed in its response to changing functional demands. The adaptive potential of muscle provedes a logical framework for understanding neural influences on the emergence of fiber types during muscle development. It is also relevant to the study of pathological conditions which may involve a sustained departure from normal postural and locomotor patterns of activity.
Penicillamine‐induced myositis in rheumatoid arthritis
Authors: Morgan G. James , McGuire James L. , Ochoa José 
Published: January 2005

AbstractA patient with rheumatoid arthritis who developed multiple mononeuropathies multiplex was shown to have vasculitis in nerve biopsy, but no evidence of inflammatory muscle disease in muscle biopsy. Treatment with penicillamine caused the rare complication of polymyositis, documented clinically, electrophysiologically, and by light and electron microscopy in a second muscle biopsy. The evidence presented supports the concept that penicillamine may induce polymyositis or aggravate a preexisting low‐grade myositis.
Clinical trial in duchenne dystrophy. I. The design of the protocol
Authors: Brooke Michael H. , Griggs Robert C. , Mendell Jerry R. , Fenichel Gerald M. , Shumate Jack B. , Pellegrino Richard J. 
Published: January 2005

AbstractTherapeutic trials in muscular dystrophy have often been inconclusive. A protocol has been designed which selects patients with Duchenne muscular dystrophy and permits accurate measurement of their status. An integral part of the protocol is a system for checking on the consistency of the data obtained using a computer program.
Muscle fiber necrosis in murine dystrophy
Authors: Ontell Marcia 
Published: January 2005

AbstractA sampling technique based on spaced serial ultrathin sections was used to examine the ultrastructure and cytoarchitecture of myofibers, which were necrotic throughout their length, in the dytrophic mutant mouse (C57BI6J/dy2J). Regional variations along the length of the myofibers were described. The necrotic fibers extended the full length of the muscle fascicle and did not branch. In necrotic fibers which were free of invasive cells, the only nuclei found under the basal lamina were peripherally placed, euchromatic myonuclei, or nuclear membrane remnants. In these fibers, the nuclear population was ∼ 14% of the nuclear population of “healthy” fibers from the same animals. No myosatellite cells were observed to be associated with these necrotic fibers. In necrotic fibers, which had undergone foreign cell invasion, the existence of a pleomorphic population of mononucleated invasive cells, many of which had not begun to express phagocytic characteristics, caused considerable confusion, because their appearance tended to mimic that of myonuclei or satellite cells. No heterochromatic nuclei or true myosatellite cells were found associated with necrotic fibers displaying macrophage invasion.
Isometric contractions of normal and spastic human skeletal muscle
Authors: Ismail H. M. , Ranatunga K. W. 
Published: January 2005

AbstractIsometric contractile properties of human elbow flexor muscles were examined in 27 normal subjects (7 females and 20 males). Contractions of elbow flexors were elicited by application of electrical pulses to the biceps motor points. The tension development was recorded at the wrist with the elbow angle fixed at 90°–100°. The data for the time to peak and time to half relaxation of the twitch, the twitch tension‐to‐tetanus tension ratio, and the posttetanic twitch potentiation are reported. The contractile properties of spastic elbow flexor muscles from 7 subjects who had been hemiparetic for periods ranging from 4 months to 60 months were found to be similar to those of muscles in normal subjects and unaffected muscles in hemiparetic subjects.
An autopsy study of a familial oculopharyngeal muscular dystrophy (OPMD) with distal spread and neurogenic involvement
Authors: Schmitt Horst P. , Krause K.‐H. 
Published: January 2005

AbstractAn 81‐year‐old man from a family with a history of oculopharyngeal muscular dystrophy (OPMD) involving 6 members over 4 generations is described. The patient first noted drooping of his eyelids at the age of 65. Dysphagia and dysarthria occurred soon thereafter. At age 78, impairment of gait developed and progressive wasting occurred in the limbs with an initial distal distribution. Electromyography of several limb muscles displayed a mixed myopathic and neurogenic pattern with giant potentials. Examination at autopsy revealed slight loss of neurons in the anterior horns of the spinal cord, with scanty ghost cells, neuronophagia, and central chromatolysis. By light microscopy the limb muscles showed moderate small‐group atrophy with severe myopathy and target fibers. The viscerocranial muscles, including the ocular, vocal, and tongue muscles, demonstrated only myopathic change with the typical features of progressive muscular dystrophy. Advanced replacement by fibrous connective tissue and fat had occurred in both the viscerocranial and the lower limb muscles. The significance of neurogenic involvement in OPMD is discussed.
Canine muscle fiber types and susceptibility of masticatory muscles to myositis
Authors: Orvis Julia Stephens , Cardinet George H. 
Published: January 2005

AbstractThe myofiber type composition was studied in 42 different muscles of the dog to determine if there are unique features that might explain the preferential involvement of the muscles of mastication by inflammatory myopathies. The principal myofiber types for most muscles studied were type 1 and type 2A and, to a lesser extent, type 2C, wherease the dorsal group of muscles innervated by the mandibular nerve (Mm. temporalis, masseter, pterygoideus lateralis, pterygoideus medialis, tensor tympani, and tensor veli palatini) was composed only of type 2C myofibers and a variant of the type 1 myofiber whose staining intensity was not fully reversed after preincubation in acid media. The distribution of this myofiber type composition was associated with the innervation and embryologic development of the dorsal muscles innervated by the mandibular nerve. This unique myofiber type composition could provide the basis for the preferential susceptibility of these muscles to agents (e.g., immune and/or infectious) that produce myositis; however, further studies are required to assess that possiblity.
A possible role for glucocorticoids in denervation atrophy
Authors: DuBois Debra C. , Almon Richard R. 
Published: January 2005

AbstractSkeletal muscle atrophies after denervation. Glucocorticoids also cause skeletal muscle to atrophy. The data presented in this report demonstrate that after denervation there is a significant increase in the number of glucocorticoid receptors in the cytosol of skeletal muscle of rats. The results are consistent with the hypothesis that a skeletal muscle atrophies after denervation because it becomes hypersensitive to glucocorticoids.
Changes in the forms of the components of the troponin complex during regeneration of injured skeletal muscle
Authors: Dhoot Gurtej K. , Perry S. Victor 
Published: January 2005

AbstractUsing the immunoperoxidase technique, antibodies to the fast components of the troponin complex stained all regenerating cells after localized alcohol injury to rat skeletal muscle. Antibodies to slow troponin components stained only some of these cells. About 6 weeks after injury with the nerve intact, the fast and slow forms of the troponin components were located in different cells. During the later stages of regeneration, staining for myosin ATPase correlated with the staining with antibodies to fast and slow troponin components. A similar staining pattern was also observed in the early stages of regeneration of muscle denervated at the time of injury. In this case, antibodies to fast skeletal muscle troponin components continued to stain all the cells 10 weeks after injury. Injured denervated muscle cells stained equally dark by myosin ATPase after preincubation at pH 9.4 over this period. None of the regenerating myotubes in denervated muscle stained for myosin ATPase after preincubation at pH 4.3.
D‐penicillamine‐associated myasthenia gravis: Immunological and electrophysiological studies
Authors: Fawcett Peter R. W. , McLachlan Sandra M. , Nicholson Louise V. B. , Argov Zohar , Mastaglia Frank L. 
Published: January 2005

AbstractImmunological and electrophysiological features were investigated in a patient with rheumatoid arthritis who developed myasthenic symptoms after 10 months of treatment with D‐penicillamine (D‐pen). After an initial rise, acetylcholine receptor (AChR) antibodies gradually fell from 24.4 nmole α‐bungarotoxin bound/liter to 1.8 nmole/liter following withdrawal of the drug, and this was associated with clinical and electrophysiological improvement. Immunoglobulin synthesis by peripheral blood lymphocytes cultured with pokeweed mitogen and D‐pen was significantly increased at D‐pen concentrations of 10–100 μg/ml in 2 patients with D‐pen associated myasthenia gravis and 1 out of 3 normal individuals. Furthermore, lymphocytes from 1 myasthenic patient synthesized detactable AChR antibodies in vitro, and the amount of receptor antibody produced was increased in the presence of the drug. This effect was most marked at a concentration of 10 μg/ml which is thought to approximate the concentration in vivo. Our results confirm the in vivo findings of others that D‐pen may have different effects on immunoglobulin production in different individuals and may also enhance the synthesis of at least 1 autoantibody, the AChR antibody.
Dual type of facilitation at the neuromuscular junction of the frog
Authors: Hort‐Legrand Claudine , Metral Stéphane 
Published: January 2005

AbstractEnd‐plate potentials were recorded intracellularly at the frog neuromuscular junction. Facilitation produced by conditioning shocks applied to the motor nerve was studied in two different ways: using either low‐frequency trains in Mg‐blocked preparations or using brief high‐frequency trains followed by a test shock of variable latency in D‐tubocurarine‐blocked preparations. In both cases, two distinctly different types of motor end‐plates were observed. The first type showed a low quantum content and a marked facilitation without depression, while the second type showed a high quantum content, a poor facilitation, and a marked depression. The physiological significance of these findings is discussed.
Fragmentation analysis of normal and dystrophic avian muscle
Authors: Feit Howard , Stauver Marguerite , Domke Robert , Shay Jerry W. 
Published: January 2005

AbstractA difference between normal and dystrophic avian muscle was demonstrated by comparing the patterns of fragmentation of muscle during homogenization. Fragmentation was monitored by morphological methods and by viscometry. This method of fragmentation analysis depends on the principle that the viscosity of a suspension is an exponential function of the partial volume fraction occupied by the suspended particles; the more a tissue is fragmented into smaller pieces, the greater the viscosity of the resulting homogenate. Increasing the duration of homogenization of either fresh muscle in buffer or glycerinated muscle in relaxing solution gradually increased the viscosity of the homogenate of normal muscle, whereas the viscosity of the homogenate of dystrophic muscle remained approximately constant. This difference in viscosity indicated that dystrophic muscle was sheared into larger pieces which were resistant to further fragmentation. Electron microscopic examination showed that the homogenate of dystrophic muscle contained rows of sarcomeres, whereas normal muscle was sheared into amorphous masses of myofilaments.
Myotonic electromyographic activity in complexus muscles of normal and dystrophic chicks
Authors: Entrikin Richard K , Randall William R. , Wilson Barry W. 
Published: January 2005

AbstractMyotonic‐like, “dive‐bomber” discharges were recorded from complexus (“hatching”) muscles of both normal and dystrophic chicks at 5 days exovo and were recordable from dystrophic, but not from normal, pectoralis major muscles at 28 days ex ovo. The complexus muscle, therefore, provides the opportunity to study in young, normal animals, a from of electrophysiological activity previously considered a sign of neuromuscular abnormality.
Reduced axonal transport of 10S acetylcholinesterase in dystrophic mice
Authors: Brimijoin Stephen , Schreiber Patricia A. 
Published: January 2005

AbstractExtracts of extensor digitorum longus muscle, atria, brain, and sciatic nerve from phenotypically normal and dystrophic ReJ/129 mice were subjected to sucrose density gradient ultracentrifugation, and the amounts of acetylcholinesterase (AChE) activity associated with each major enzyme form were determined. Normal muscle showed approximately equivalent amounts of the 4S, 10S, and 16S forms of AChE, while dystrophic muscle was relatively deficient in 10S AChE and relatively oversupplied with 4S AChE. This abnormality was not present in the other tissues examined. However, as measured by the 24‐hour accumulation of enzye activity proximal to a ligature on the sciatic nerve, the axonal transport of 10S AChE was only about one third as great in dystrophic as in normal nerve. This result is consistent with the view that the reduction in the amount of this enzyme form in dystrophic muscle could be related to disturbances in a transport‐dependent trophic interaction between nerve and muscle.
Beneficial effects of transplanting normal limb‐bud mesenchyme into dystrophic mouse muscles
Authors: Law Peter K. 
Published: January 2005

AbstractA new technique is being developed to remedy muscle weakness of hereditary myopathies. Mesenchymal cells dissected from limb‐buds of day‐12 normal mouse embryos were transplanted into the right solei of 20‐day‐old normal or dystrophic C56BL/6J‐dy2J mice. Host and donors were immunocompatible. Unoperated left solei served as controls. Sham control solei receiving similar surgical treatment but no mesenchyme transplant did not differ from contralateral, unoperated solei. Six to seven months postoperatively the test solei (8 normal and 15 dystrophic) exhibited greater cross‐sectional area, total fiber number, and twitch and tetanus tensions than their contralateral controls. Test dystrophic solei contained more normal‐appearing and less abnormal‐appearing fibers than their controls. Their mean fiber resting potential was intermediate between those of normal and dystrophic controls. There is no difference in twitch time course between test and control solei. The results indicate that such transplantation improves the structure and function of the dystrophic muscles.
Autophagic degradation in human skeletal muscle target fibers
Authors: Mrak Robert E. , Saito Akitsugu , Evans Owen B. , Fleischer Sidney 
Published: January 2005

AbstractTarget fibers are a reliable histological sign of denervating processes in human skeletal muscle biopsies, although their pathogenesis remains obscure. We describe here autophagic multivesicular bodies at the center of target fibers. In addition, mitochondrial swelling and disintegration was observed in the intermediate zone surrounding the target center, which corresponds to the zone of dark staining with oxidative histochemical techniques seen with light microscopy. Honeycomb figures were present at the target center and at the fiber surface. These findings suggest that target fibers are a catabolic or involutional response to muscle denervation.
Segmental necrosis in tenotomized muscle fibers
Authors: Baker James H. 
Published: January 2005

AbstractA study of the soleus muscle of the rat along its entire length during the first week following tenotomy was undertaken. Within the first few days the affected fibers of the soleus underwent a complete morphological reorganization. Portions of fibers near the tendons were Invaded by and replaced with a large population of phagocytes. Previous studies have implied that the number of sarcomeres in series is reduced, but it has not been demonstrated from what portion of the fiber the sarcomeres are revoved. Sections of fibers taken from the mid‐belly region demonstrated a progressive degenerative process over the first few days. Myofibrils across the entire width of the affected fibers underwent dissolution and degeneration. Fibers with central core lesions could be found by the seventh day after tenotomy, however, at this stage the peripheral myofibrils were new, and the fibers had begun the regenerative process which continued until normal fiber histology was restored.
Mallory body‐like inclusions in a hereditary congenital neuromuscular disease
Authors: Fidzianska Anna , Goebel Hans H. , Osborn Mary , Lenard Hans G. , Osse Günter , Langenbeck Ulrich 
Published: January 2005

AbstractSubsequent to an earlier report on clinical and light microscopic data, peculiar Mallory body‐like inclusions are described in muscle fibers of three genetically linked children. These Mallory body‐like inclusions were unlike other well‐defined intramuscular inclusions, such as nemaline, cytoplasmic, fingerprint, or sarcoplasmic bodies, but morphologically quite similar to hepatic Mallory bodies, because they were composed of three components: granular material and two types of filaments. Evidence is presented that these inclusions may contain desmin, the intermediate filament type characteristic of muscle. The exclusive appearance of these Mallory body‐like inclusions in muscle biopsy specimens from theree genetically related children of a large kinship emphasizes the uniqueness of these Mallory body‐like inclusions in these muscle fibers as well as the special form of this congenital neuromuscular disorder.