bluuebunny/crossref_metadata_2025 huggingface dataset:
Positron emission tomography demonstrates dopamine D2 receptor supersensitivity in the striatum of patients with early Parkinson's disease
Authors: Rinne U. K. , Laihinen A. , Rinne J. O. , Naågren K. , Bergman J. , Ruotsalainen U.
Published: January 2005

Striatal dopamine D2 receptor binding was studied in vivo with positron emission tomography in seven patients with early Parkinson's disease using [11C]–raclopride. The patients had unilateral symptoms and none of them had received levodopa treatment. The accumulation of [11C]–raclopride in the striatum was rapid and reached a steady state at approximately 40 min after injection. The binding of [11C]–raclopride was measured in the striatum and cerebellum: The total striatal radioactivity in both hemispheres was counted and the respective striatum/cerebellum ratios were calculated. The striatum/cerebellum ratio of [11C]–raclopride binding was significantly (p < 0.01) increased in the hemisphere contralateral to the parkinsonian symptoms as compared with the opposite hemisphere. Thus, this study demonstrates that there is denervation supersensitivity in dopamine D2 receptor binding in early Parkinson's disease.
Tremor and idiopathic dystonia
Authors: Jedynak C. P. , Bonnet A. M. , Agid Y.
Published: January 2005

The clinical and electromyographic characteristics of tremor were studied in 45 patients presenting with various forms of idiopathic dystonia. Dystonic tremor was shown to be postural, localized, and irregular in amplitude and periodicity, absent during muscle relaxation, exacerbated by smooth muscle contraction, and associated frequently with myoclonus. Although it resembles essential tremor, dystonic tremor seems to be a distinct entity: it is more irregular witha broader range of frequecies; it is asymmetric and remains localized; myoclonus is sometimes associated. This type of tremor is most often seen in the presence of dystonia, but may be observed without evident dystonic symptoms.
Parkinsonism and extraocular motor abnormalities with unusual neuropathological findings
Authors: Calabrese Vincent P. , Hadfield M. Gary
Published: January 2005

Parkinsonian patients with ocular motility abnormalities are usually considered to have progressive supranuclear palsy. However, a number of other conditions have been noted to have the combination of parkinsonism and ocular problems. We report a case of rigid akinetic parkinsonism, oculomotor palsy, and eyelid apraxia with postmortem examination. Our findings are unusual in that there was marked gliosis of the substantia nigra with a large amount of free extracellular neuromelanin despite a 3‐year clinical course. Only rare hyaline inclusion bodies and no neurofibrillary tangles were seen in the brainstem. Excessive calcification of the vessels of the globus pallidus were also noted. This case represents another example of the diversity of conditions producing parkinsonism with extraocular motor abnormalities.
Treatment outcomes in cervical dystonia: A clinimetric study
Authors: Lindeboom R. , de Haan R. J. , Aramideh M. , Brans J. W. M. , Speelman J. D.
Published: January 2005

We reviewed 21 studies (8 blinded and 13 open) on the treatment of botulinum toxin type A for cervical dystonia, directed to the health aspects used to evaluate the patients' response to treatment (Medline search 1985–1993, English language literature). The prerequisite for comparing the treatment results was that studies had to evaluate similar aspects of disease. The ICIDH model, outlined by the World Health Organization in 1980, orders the different health outcomes into distinct classes of disease consequences. Our aim was to order the health outcomes according to the model and, thus, to study the comparability of treatment outcomes. Three differences could be identified between the objective and the subjective instruments. (a) The aspects measured by the subjective instruments varied substantially; of the 22 different subjective instruments identified in 18 studies, 8 measured impairments, 5 disability, and 9 could not be classified according to the ICIDH model. The objective instruments measured impairments. (b) All objective instruments were multiitem, whereas only 2 of 22 subjective instruments could be identified as multiitem. (c) The subjective instruments were generally poorly documented with regard to the number of items, score range, or grading. We conclude that the treatment outcomes can only be compared on the objective level of assessment and with regard to the patients with painful dystonia. The subjective instruments, particularly those focusing on disease‐specific disability, deserve further research. The ICIDH model offers a useful framework for selection, improvement, and development of outcome instruments. Because the model clearly demarcates the different consequences of disease, adoption will enhance the comparability of outcomes in cervical dystonia intervention trials.
Brainstem myoclonus in a patient with non‐dopa‐responsive parkinsonism
Authors: Clouston P. D. , Lim C. L. , Fung V. , Yiannikas C. , Morris J. G. L.
Published: January 2005

In the few reports where electrophysiologic techniques have been used to characterise stimulus sensitive myoclonus in the setting of a parkinsonian syndrome, the origin of the myoclonus has usually been found to be cortical. We describe a patient with parkinsonism unresponsive to levodopa who had myoclonus that was both spontaneous and induced by somatosensory stimuli. In addition, autonomic symptoms and a marked sleep disturbance were present early in his illness. Results of electrophysiologic investigations including electromyography (EMG) studies, routine electroencephalography (EEG) recording, jerked locked back‐averaging of EEG, and somatosensory evoked potentials were consistent with a brainstem origin for the myoclonic jerks. Following ipsilateral digital and supraorbital electrical stimulation, the earliest muscle activation occurred in the trapezius. An all night sleep study showed frequent myoclonic jerks during sleep and markedly abnormal sleep architecture. We believe that this patient's myoclonus was related to pathologic changes in brainstem reticular nuclei that occurred as part of his disease process. To our knowledge, brainstem myoclonus has not been described as a feature of parkinsonian syndromes.
Subacute skeletal myopathy induced by 2,4‐dichlorophenoxyacetate in rats and guinea pigs
Authors: Danon Jak M. , Karpati George , Carpenter Stirling
Published: January 2005

Rats and guinea pigs were injected with 2,4‐dichlorophenoxyacetate (2,4‐D) in amounts sufficient to keep them myotonic for over 12 hr daily. The biceps brachii muscles were studied by histochemistry, epoxy resin histology, and electron microscopy after one to five days. Changes observed include proliferation of the longitudinal component of the sarcoplasmic reticulum, production of new myofilaments on the periphery of cells and in nuclei, activation of satellite cells, accumulation of lipid droplets, myofibrillar damage with Z‐disc streaming, necrosis, and regeneration. The action mechanisms of 2,4‐D are not well understood. Some of the phenomena observed could be classified as proliferative and may be analogous to the auxin action of 2,4‐D in plants. The production of intranuclear filaments is probably related to the diffusion of newly formed cytoplasmic proteins into nuclei.
Sensory (1a) and F‐wave conduction velocity in the proximal segment of the tibial nerve
Authors: Panayiotopoulos Chrysostomos P. , Scarpalezos Spiros , Nastas P. E.
Published: January 2005

The F‐wave was used to estimate the fastest motor nerve conduction velocity (MNCV) along the proximal segment (spinal cord to knee) of the axons of the tibial nerve in 65 control subjects, 8 patients with diabetic polyneuropathy, and 4 patients with Charcot‐Marie‐Tooth disease. Terminal latencies and MNCV along the distal segment (knee to ankle) of the nerve were also estimated with the conventional M‐response technique. This article describes another method for estimating sensory nerve conduction velocity (SNCV) along 1a fibers of the tibial nerve for the spinal cord‐to‐knee segment. Proximal and distal MNCV showed moderate slowing in patients with diabetic polyneuropathy and severe slowing in those with Charcot‐Marie‐Tooth disease. In 17 control subjects, proximal MNCV for the axons supplying the abductor hallucis muscle was compared to that estimated for the axons to the gastrocnemius muscle. MNCV for the proximal is faster than that for the distal small muscle. In 2 patients, M‐ and F‐responses were not obtained from the abductor hallucis; in these patients, effective estimation of the proximal MNCV was made from the gastrocnemius muscle and showed marked reduction.
Amino acid transport by a muscle cell line
Authors: Logan William J.
Published: January 2005

An established rat muscle cell culture, L‐6, was employed for the evaluation of muscle amino acid transport. The initial influx of 16 radiolabeled amino acids into these cells was determined, and an overall uptake profile was constructed. L‐6 cells accumulate amino acids progressively with time by saturable, temperature‐dependent processes. As found in other preparations, several amino acids have sodium‐dependent uptake systems. There is a wide range in the rate of transport of the different amino acids. The overall profile of uptake is fairly reproducible and may be characteristic of muscle tissue; it does not resemble that previously found in other cell types. The profile of amino acid uptake into these cells compares favorably with the pattern of amino acid transfer from bloodstream to muscle found in intact rats. It is concluded that muscle cell transport is basically similar to that of other cell types. L‐6 muscle cells have an amino acid uptake profile which resembles that of intact muscle; they should thus prove useful in the further delineation of muscle amino acid transport mechanisms.
Monomelic muscle hypertrophy following transient ischemic attacks: A case report
Authors: Isaacs Edward R. , Larson Paul
Published: January 2005

A 39‐year‐old right‐handed male suffered several episodes of transient right‐sided weakness, sensory loss, and Broca's aphasia at age 31. Diagnostic studies failed to demonstrate any cause for these events. Following a complete recovery, he noted the onset of stiffness and increasing muscle bulk in his right arm, which gradually restricted its use. Simultaneous recordings from contracting biceps and triceps muscles in both arms suggested that the hypertrophy was physiologically induced by an abnormal mechanism providing resistance during phasing activity.
Electrodiagnostic findings in acute porphyric neuropathy
Authors: Albers James W. , Robertson William C. , Daube Jasper R.
Published: January 2005

Of 115 patients with acute intermittent porphyria seen during a 20‐year period, 11 had experienced an acute episode of quadriparesis. Nerve conduction studies performed on 8 of these 11 patients showed lowamplitude compound action potentials and normal velocity measurements. Needle electromyography demonstrated prominent fibrillation potentials, especially in proximal muscles. The changes in these findings with time confirm that this disorder is an acute axonal neuropathy.
Histology and ultrastructure of alterations in neuropathy
Authors: Behse Friedrich , Carlsen Frits
Published: January 2005

Histologic findings are described in nerves from men exposed to lead, from patients with discrete clinical signs of peripheral neuropathy, and from controls. Every nerve from control subjects showed an abnormality (paranodal remyelination, segmental remyelination, or regeneration) in teased fibers. The only histologic alteration in eight lead‐exposed males without signs or symptoms of neuropathy was a slightly increased incidence of paranodal remyelination. Sixteen patients with discrete neurologic symptoms and signs had a loss of large myelinated fibers and an increased incidence of regenerated fibers among teased fibers. Electron microscopy of unmyelinated fibers showed an increased occurrence of Schwann‐cell processes, of fibers undergoing degeneration, and of Schwann‐cell subunits with many profiles as the earliest signs of abnormality. Clinically mild neuropathies may exhibit advanced regeneration in the case of unmyelinated fibers. The earliest sign of degeneration in myelinated fibers was a diminution in the number of axonal organelles.
Preservation of bulk and strength in muscles affected by neurogenic lesions
Authors: Willison Robin G.
Published: January 2005

Mechanisms involved in maintaining bulk and strength in partially denervated muscles of patients with neurogenic lesions are discussed. Estimation of muscle fiber hypertrophy by electrophysiological examination is possible, but it depends on the construction of sampling electrodes with precise geometry. The arrangement of muscle fibers of motor units within the muscle is discussed by analogy with the four‐color map problem. An experiment to measure the twitch tensions of individual motor units in man is devised; it requires the use of microprocessor control of the stimulus and recurrent measurements of the twitch forces.
Pattern of electrical activity in normal and diseased muscle
Authors: Fuglsang‐Frederiksen A.
Published: January 2005

Examination of the number of spikes (turns) per 5 sec and the mean amplitude of electrical activity, measured both at a force adjusted relative to maximum force (Po) and at a standard force, made it possible to distinguish between (1) a decrease in force arising from loss or inactivity of motor units, and (2) loss of muscle fibers or diminution in their cross‐sectional area. The initial decrease in force of disused quadriceps muscle (following immobilization of the knee joint) resulted mainly from inactivity of motor units. In patients with motoneuron disease or a lesion of the brachial plexus, the number of turns at a force adjusted relative to Po was diminished because of increased potential duration and loss of motor units. Turns at a standard force of 2 kg were normal. In myopathy, the ratio of turns to amplitude was increased in two‐thirds of the patients.
Myosin changes in experimental 2,4‐dichlorophenoxyacetate myopathy
Authors: Muhlrad Andras , Friedman Margalit
Published: January 2005

Young rats treated with 10 to 14 daily injections of 2,4‐dichlorophenoxyacetate (2,4‐D) developed a myopathy mainly involving fast muscles. Myosin isolated from the gastrocnemius muscles of treated and normal control animals differed in several respects. The Ca2+− and Mg2+ ‐mediated ATPases were higher in myopathic muscle myosin than in normals. Alkylation of thiols by N‐ethylmaleimide (NEM) induced an increase of Ca2+ ‐activated ATPase that was higher in normal than in myopathic myosin. Trinitrophenylation of reactive amino groups by 2,4,6‐trinitrobenzene sulfonate (TBS) induced an increase in Mg2+ ‐mediated ATPase in both preparations, but the increase was higher in normals. Although the heavy‐ and light‐chain pattern was identical in normal and myopathic myosin, during storage at 0°C the relative amount of myopathic L2 light chain decreased. Myosins fragmented either by limited proteolysis with trypsin and chymotrypsin or by specific cleavage at tryptophanyl and cysteinyl peptide bonds showed differences on sodium dodecylsulfate (SDS)‐polyacrylamide‐gel electrophoresis. The results indicate that there is a change in the heavy chains of myosin isolated from the gastrocnemius muscle in 2,4‐D‐induced rat myopathy.
Myosin autoantibodies reacting with selective muscle fiber types
Authors: McDonald Brian L. , Dawkins Roger L. , Robinson Jennifer
Published: January 2005

Myosin in striated muscle exists in at least two immunologically distinct forms. Human autoantibodies specific for either form show selective muscle fiber reactivity. One group of antibodies reacts with type 2b (white) muscle fibers, the other with type 2a (red) and type 1 (intermediate) fibers. All of these antibodies react with the A band of glycerinated myofibrils. Both groups of antibodies react with cardiac muscle. Muscle‐fiber‐specific antibodies are detected in approximately 1% of sera submitted for diagnostic screening. Sera from eight patients were studied further. The two patients with antibodies against type 2b (white) muscle myosin had rheumatoid arthritis. The six patients with antibodies against type 2a (red) and type 1 (intermediate) myosin had clinical features which included various autoimmune and infectious disorders.
Lack of benefit of allopurinol in duchenne dystrophy
Authors: Mendell Jerry R. , Wiechers David O.
Published: January 2005

A double‐blind, controlled study was conducted to assess the effects of allopurinol on Duchenne muscular dystrophy. Six patients—three treated with allopurinol and three given a placebo—were followed up for one year and were evaluated by functional and manual muscle testing as well as by determination of serum creatine kinase (CK) levels. Patients in both the allopurinol‐treated group and the placebo group deteriorated at varying rates without evidence of therapeutic benefit. To exclude the possibility of error attributable to small sample size, all six patients were treated with allopurinol for an additional eight‐week period. Muscle strength continued to deteriorate during this phase of the study.
Delayed functional disability in dystrophic chickens receiving chemotherapy
Authors: Hudecki Michael S. , Pollina Catherine M. , Bhargava Arvind K. , Hudecki Rajmohini S. , Heffner Reid R.
Published: January 2005

Line 413 early‐onset, genetically homozygous dystrophic chickens were given twice‐daily intraperitoneal injections of the antiserotoninergic drug cinanserin, alone or in combination with methysergide. Other trials consisted of penicillamine treatment in combination with either methysergide or cyproheptadine. Chemotherapy significantly prolonged the righting ability of treated dystrophic chickens, as measured by a periodic standardized fliptest procedure. Plasma creatine kinase activities were not affected by any of the various drug treatments. However, the blood serotonin levels of the dystrophic chickens (grand mean 1.47 μg serotonin/ml blood) were found to be significantly higher (p<0.001) than those in the corresponding normal chickens (0.99 μg/ml). This finding may partially account for the antiserotoninergic drug enhancement in righting ability that was demonstrated in the drug‐treated dystrophic chickens.
Electrophysiologic properties of intercostal muscle fibers in human neuromuscular diseases
Authors: Gruener Raphael , Stern Lawrence Z. , Markovitz David , Gerdes Clarence
Published: January 2005

Electrophysiologic properties of biopsied normal and diseased intercostal muscle fibers were examined using intracellular microelectrode techniques. The resting potentials of all diseased muscle fibers were found to be depolarized. Those from Duchenne dystrophy patients showed the largest depolarization, followed by those from patients with myotonic muscular dystrophy, myotonia congenita, and motor neuron disease. All of the diseased fibers except those from myotonia congenita patients demonstrated an impaired ability to generate action potentials. In the latter fibers, the higher‐than‐normal membrane resistance was associated with hyperexcitability. When the membrane was hyperpolarized to the normal range, however, action potential characteristics in all fibers were near normal, except in motor neuron disease. All action potentials were blocked by tetrodotoxin. These findings—i.e., that all fibers were capable of generating action potentials when hyperpolarized, and that all action potentials were blocked by tetrodotoxin—suggest the relative intactness, in the disease studied here, of the regenerative sodium conductance mechanism.
Antigenic modulation and receptor loss in experimental autoimmune myasthenia gravis
Authors: Lindstrom Jon , Einarson Brett
Published: January 2005

Immunization of groups of rats with 0.1–100 μg of acetylcholine receptor (AChR) purified from the electric organ of Torpedo californica resulted in dose‐dependent (1) loss of acetylcholine receptor from the rats' muscles, (2) binding of antibodies to many of the receptors remaining in muscle, and (3) production of antibodies in serum capable of cross‐reacting with receptor solubilized from rat muscle. Addition of antibodies from rats immunized with electric organ acetylcholine receptors to muscle cells in culture caused loss of receptor by accelerating the rate of receptor degradation. Monovalent antibody fragments did not accelerate degradation unless antiantibody was added to cross‐link the monovalent antibody fragments bound to receptors. This indicates that cross‐linking of receptors by antibody molecules triggers accelerated receptor degradation, leading to receptor loss. The rate of increase in receptor destruction due to antigenic modulation observed in vitro appears sufficient to account for the extent of receptor loss observed in vivo. Endocytosis of antibody cross‐linked receptors may be a rate‐limiting step common to antigenic modulation in vitro and in vivo.
Penicillamine‐induced myasthenic responses in the guinea pig
Authors: Burres Steven A. , Richman David P. , Crayton John W. , Arnason Barry G. W.
Published: January 2005

To study the basis for the myasthenic illness that develops in some patients receiving D‐penicillamine (D‐P), we measured neuromuscular transmission in D‐P‐treated guinea pigs. Treated animals manifested edrophonium chloride–repairable decremental responses to 30‐Hz nerve stimulation (8.5% ± 1.5%—mean ± SEM; N = 16) compared with the response in saline‐treated control animals (−0.3% ± 0.85%, N = 10, p <0.005). Posttetanic phenomena were studied in 5 treated animals; 3 revealed posttetanic exhaustion. Miniature endplate potential (MEPP) amplitudes were significantly reduced in 11 treated animals (0.612 ± 0.016 mV) compared with 6 controls (0.713 ± 0.024 mV, p <0.01). The MEPP frequency appeared reduced in treated animals. Both MEPP amplitude and MEPP frequency correlated with the decrement.
Weakness from magnesium‐containing cathartics: Electrophysiologic studies
Authors: Swift Thomas R.
Published: January 2005

The case history of a patient with severe muscular weakness resulting from magnesium intoxication following oral and rectal administration of magnesium citrate cathartics is reported. The findings of the electrophysiologic studies were characteristic of the neuromuscular blockade seen in this disorder, including marked reduction in evoked muscle action potential amplitude which progressively declined on nerve stimulation at low rates, and a striking degree of facilitation of evoked muscle action potential after exercise or on high‐frequency stimulation. When the hypermagnesemia was corrected, strength returned to normal.
Red cell membrane protein phosphorylation in hemolytic anemias and muscular dystrophies
Authors: Tsung Pi‐Kwang , Palek Jiri
Published: January 2005

We review our current understanding of membrane phosphorylation in normal and abnormal erythrocytes. The major phosphoproteins in red blood cell (RBC) membranes are spectrin (band 2), bands 3, 2.1, and 4.5, and glycophorin A. At least two protein kinases can be distinguished on the basis of their stimulation by cyclic AMP and salt; they are present both in the membrane and in the cytosol. Analysis of the conflicting data on endogenous membrane‐protein phosphorylation in abnormal RBCs indicates a considerable variability of phosphorylation rates which largely depends on the manner of preparation of ghosts and enzyme assay conditions. This variability reflects differences in the partitioning of protein kinases between the membrane and cytosol, the specificity and accessibility of membrane‐protein substrates, and reaction kinetics. We select examples of data from several hemolytic anemias to illustrate that precautions are needed to interpret abnormalities of membrane‐protein phosphorylation properly; we discuss possible new methodological approaches.
Tubular aggregates in murine dystrophy heterozygotes
Authors: Craig I. D. , Allen Ingrid V.
Published: January 2005

Heterozygous dystrophic mice (strain 129 ReJ dy/+) were studied to determine the morphological changes that are characteristic of the heterozygote state. The morphology of the muscle in 35 heterozygotes (+/?) was compared with that of 35 homozygotes (dy/dy) and 20 normal controls (+/+). Muscle was examined with light microscopy, standard histochemical techniques, and electron microscopy. Few abnormalities were detected with light microscopy or with histochemistry. With electron microscopy, some slight nonspecific evidence of muscle damage in the form of focal myofibrillar degeneration was seen in all of the heterozygotes. The striking abnormality, however, was the presence of tubular aggregates in type 2 fibers in 60% of the heterozygotes. Tubular aggregates were not found in homozygous dystrophic mice or in normal controls. The significance of this finding is discussed and it is suggested that tubular aggregates may represent lateral sac dilatation and infolding.
Isolated mechanical lesions of the sural nerve
Authors: Gross John A. , Hamilton William J. , Swift Thomas R.
Published: January 2005

One case of compression on neuropathy and one case of iatrogenic stretch injury to the sural nerve were demonstrated with electrophysiologic (EP) testing. Isolated mechanical injuries to the sural nerve may occur more frequently than is generally realized, and EP studies can greatly aid in the diagnosis of these injuries, thus avoiding the necessity for neuroradiologic investigations.
Measurement of local skeletal muscle blood flow in animals by the hydrogen electrode technique
Authors: Mishra Shri K. , Haining Joseph L.
Published: January 2005

The hydrogen (H2) electrode technique has been applied to the measurement of local skeletal muscle blood flow (LSMBF) in experimental animals (rats, rabbits, and monkeys). LSMBF was measured during resting and postexercise states, following epinephrine injections and during CO2 inhalation. Among the limited sites studied and/or measurements obtained, significant differences in LSMBF were found in only a few instances. During hypercapnia, LSMBF was found to be increased in some muscles in rats and monkeys. The present study demonstrates that the H2 electrode technique is a simple and reliable method for measuring resting and postexercise LSMBF in anesthetized animals. This method provides measurements at discrete loci, is easily reproducible, and causes little trauma.
Measurement of local skeletal muscle blood flow in normal humans by hydrogen clearance
Authors: Mishra Shri K. , Haining Joseph L.
Published: January 2005

The hydrogen (H2) electrode technique was adapted to the measurement of local skeletal muscle blood flow (LSMBF) in humans. Thirty‐five normal volunteers were utilized to study the biceps, deltoid, gastrocnemius, and quadriceps muscles at rest and following exercise. Results indicated statistically significant increases (P < 0.05) in postexercise compared with resting blood flows within the muscles. The highest mean value for LSMBF was found in deltoid muscle and the lowest in biceps. This study demonstrates the potential superiority of the H2 electrode technique over previous techniques for measuring absolute muscle blood flow at individual sites. It is suggested that measurements by means of the H2 electrode technique represent the most definitive values for skeletal muscle blood flow at this time, and its application could be especially important in various neuromuscular disorders in which some question remains concerning the role of abnormalities of the skeletal muscle vasculature.
Critical reexamination of the thymus immunization model of myasthenia gravis
Authors: Murphy Anne , Drachman Daniel B. , Satya‐Murti S. , Pestronk Alan , Eggleston Joseph C.
Published: January 2005

Previous studies have described an experimental model of myasthenia gravis (MG) produced by immunizing animals with thymus extracts. In view of the hypothesis that the autoimmune process in MG may be initiated within the thymus itself, we have reexamined this model using presently available methods to evaluate its resemblance to MG. We immunized Lewis rats with extracts of rat thymus in Freund's adjuvant, as originally described by G. Goldstein. Five procedures were used to test for myasthenic characteristics: (1) repetitive nerve stimulation; (2) recording of miniature endplate potentials; (3) assays of anti‐ACh receptor antibodies in serum; (4) determination of ACh receptors at neuromuscular junctions by [125|] α‐bungarotoxin binding; and (5) evaluation of the histology of the thymus gland. Our results showed that the thymus‐immunized animals did not demonstrate abnormalitities in any of these parameters. We conclude that immunization of rats with thymus extracts, as described, failed to produce a myasthenia‐like condition.
Carnitine levels in normal children and adults and in patients with diseased muscle
Authors: Carrier Henri N. , Berthillier Gisèle
Published: January 2005

An assay for evaluating carnitine levels in normal children and adults is described. After a 12‐hour period of fasting, individual variations in 24‐hour urinary excretion of carnitine were observed in adults. In children, there was a significant decrease in excretion from the 10th month to the third year, and then an increase until the 10th year. There was no significant difference between children and adults in the serum and skeletal muscle levels. Muscle carnitine levels were also studied in 12 cases of lipid‐storage myopathy and in cases of other muscle diseases, including Duchenne muscular dystrophy in children.
Tibial nerve H‐reflex and F‐wave studies in patients with uremic neuropathy
Authors: Panayiotopoulos C. P. , Lagos G.
Published: January 2005

The nerve conduction velocity along the whole length (knee to the spinal cord) of the 1a sensory and motor fibers of the tibial nerve, innervating the gastrocnemius and soleus muscles, of 29 control subjects and 32 patients with chronic renal failure was estimated with recently introduced electrophysiologic F‐wave and H‐reflex methods. In control subjects and in uremic patients, the proximal sensory (1a) nerve conduction velocity (SNCV) was faster than the proximal motor nerve conduction velocity (MNCV), a finding which is attributed to the larger diameter and therefore faster conduction properties of 1a fibers. In uremic patients, the proximal 1a SNCV and MNCV were significantly slowed in comparison with the values in control subjects, while the terminal M‐response latency was not significantly prolonged.
Plasmapheresis therapy in myasthenia gravis
Authors: Dau Peter C.
Published: January 2005

Plasmapheresis in the treatment of myasthenia gravis has led to disparate results when applied by different investigators because of considerable differences in the volume, number, and tempo of plasmaphereses and in the type and amount of concomitant immunosuppressive drug therapy. Used as short‐term crisis intervention, plasmapheresis produces temporary clinical improvement and reduction in titer of antibody to acetylcholine receptor, even without accompanying drug therapy. When applied as long‐term primary therapy under optimal conditions, plasmapheresis is capable of generating stable improvement in most patients. This response appears to result from a synergistic action with immunosuppressive drugs, since it is characterized by a sustained reduction in titer of antibody to acetylcholine receptor. Where clinical circumstances warrant cytotoxic immunosuppression in patients with myasthenia gravis, consideration should be given to the simultaneous employment of plasmapheresis, in order to maximize benefit to the patient from a given exposure to drug therapy.
Polymyositis—an immunofluorescence study on the distribution of collagen types
Authors: Duance Victor C. , Black Carol M. , Dubowitz Victor , Hughes Graham R. V. , Bailey Allen J.
Published: January 2005

Type‐specific antibodies to the polymorphic types of collagen have been used to study their distribution in polymyositis. Dramatic increases were observed in the staining with antibodies to Type III collagen and, to a lesser extent, with antibodies to Types I, IV, and V. The changes in capillary and endomysial basement membrane collagens (Types IV and V) as well as the proliferation of perimysial Type III collagen are discussed in relation to the muscle atrophy observed during the disease.
A clinicopathologic study of acrodystrophic neuropathies
Authors: Said Gerard
Published: January 2005

Sixteen patients presenting with trophic changes associated with a peripheral neuropathy were investigated. Muscle power was normal in all patients, but neurogenic muscle atrophy was demonstrated in 4 of the 7 patients who had a muscle biopsy. Alcoholism was responsible for the neuropathy in 11 patients. In the other patients, one had primary hemochromatosis without diabetes and another a dominantly inherited primary hypertrophic neuropathy. Qualitative and quantitative light and electron microscopic studies, including teased nerve fiber preparations, showed axonal loss as the most salient feature. In the alcoholic patients, the large myelinated fibers were primarily involved, followed by small myelinated and unmyelinated fibers. The lesions were predominant distally as shown in patients who had a sural nerve biopsy at both calf and ankle levels. A mechanism of dying‐back degeneration of the longest sensory fibers is the most plausible explanation for neurological and pathological abnormalities. In alcoholic neuropathy with trophic changes, loss of sensory fibers is more important than in alcoholic neuropathy without trophic changes. In familial and sporadic cases, axonal loss is more severe and unmyelinated fibers are more severely affected than in alcoholic acrodystrophic neuropathy. Patients with peripheral neuropathies who present with loss of pain sensation but have preserved muscle power are especially exposed to the development of trophic changes induced by usual trauma in insensitive tissues.
Early ultrastructural changes in aging rat gastrocnemius muscle: A stereologic study
Authors: de Coster W. , de Reuck J. , Sieben G. , Eecken H. Vander
Published: January 2005

Normal gastrocnemius muscle of Wistar rats at various ages to 2 1/2 years was studied. No light microscopic or qualitative electron microscopic changes were seen. However, stereologic determinations revealed significant reductions in volume and surface densities of sarcoplasmic reticulum, t‐tubular system, and glycogen content. These alterations were considered to be the morphologic expression of the very early age‐related changes in gastrocnemius muscle.
Respiratory function in the muscular dystrophies
Authors: Rideau Y. , Jankowski L. W. , Grellet J.
Published: January 2005

The purpose of this investigation was to compare the respiratory function of patients with different clinical types of muscular dystrophy (MD). A total of 190 patients representing facioscapulohumeral MD (n = 20), limb‐girdle MD (n = 50), Becker MD (n = 20), Duchenne MD (n = 90), and the “intermediate” type of MD (n = 10) were studied using simple spirometric respiratory function tests. The respiratory modifications observed in the 3 adult forms indicate that pulmonary function was almost normal. Respiratory function in Duchenne muscular dystrophy (DMD) was always characterized by a restrictive syndrome which severely impaired pulmonary function. The vital capacity (VC) underwent ascending, plateau, and descending phases during the course of the disease. The VC at the plateau stage may be used as an estimate of life span. The most interesting finding was the high degree of variability in the restrictive syndrome associated with DMD. In the DMD group 30% presented a severe restrictive respiratory syndrome associated with a life span of less than 20 years (Type 1), 40% had a serious restrictive syndrome and variable mortality (Type 2), and the remaining 30% had a moderate restrictive respiratory syndrome (Type 3).
Experimental rapid sarcomere loss with concomitant hypoextensibility
Authors: Tabary Jean‐Claude , Tardieu Catherine , Tardieu G. , Tabary C.
Published: January 2005

Slow soleus muscle in guinea pigs was actively shortened by constant electrical stimulation of the sciatic nerve for 12 hours. At the end of this period, hypoextensibility and a 25% decrease in the numbers of sarcomeres were observed. When a 36‐ or 48‐hour period was allowed to elapse after the end of stimulation, some recovery occurred, and the sarcomere numbers were then found to be diminished by only 5%. If the stimulation was performed when the muscle was prevented from shortening (by ankle fixation in dorsiflexion), there was no decrease in sarcomere numbers and no hypoextensibility. In relation to humans, these findings may be of pathophysiological and therapeutic importance in cases of muscle hypoextensibility after neuroaxis lesions, when abnormal contractions maintain lasting shortening of the muscle.
Skeletal muscle regeneration
Authors: Allbrook David
Published: January 2005

The historical and current research literature is reviewed with special attention to the role of the satellite cell in the reconstitution of skeletal muscle following damage. Implications for the clinical management of trauma patients are stressed in the light of this new knowledge.
Abnormal RNA metabolism in spinal motor neurons in the wobbler mouse
Authors: Murakami T. , Mastaglia F. L. , Mann D. M. A. , Bradley W. G.
Published: January 2005

RNA metabolism was studied in anterior horn neurons in wobbler mice. In the wobbler mice, RNA content was reduced in histologically normal neurons but not consistently reduced in vaculated neurons, as compared with normal littermates. Nuclear and nucleolar incorporation of [5–3H]uridine was reduced both in vacuolated and in histologically normal neurons of wobbler mice, while cytoplasmic counts were higher in histologically normal neurons of wobbler mice than in vacuolated neurons or the neurons of normal littermates. These findings point to an abnormality of RNA synthesis which precedes the earliest morphological changes seen in nerve cells with the light microscope. Nuclear [5–3H]uridine uptake was reduced both in small and in large neurons, a finding suggesting that the metabolic abnormality is probably not confined to α‐motoneurons.
Serum creatine kinase in the detection of duchenne muscular dystrophy carriers: Effects of season and multiple testing
Authors: Percy Maire E. , Andrews David F. , Thompson Margaret W.
Published: January 2005

The usefulness of serum creatine kinase (CK) activity in the detection of Duchenne muscular dystrophy (DMD) carriers is dependent upon a reliable control distribution. In controls there is a small but reproducible seasonal variation in CK activity, with a statistically significant variation in the upper 95th percentile (78 IU/liter in May, 53 IU/liter in November, as compared with 67 IU/liter for the whole calendar year). Because CK values in DMD heterozygotes are higher in November than in May, the carrier detection rate may be highest in November. Failure to consider this seasonal variation in controls may cause misclassification of too many normal subjects. If tests are conducted throughout the year, however, the seasonal influence can be reduced by serial testing at intervals of several months. In this case, use of the highest of the results obtained in 3 tests compared with the normal range of single measurements misclassifies too many normal subjects. Use of the mean of 3 determinations provides more accurate classification.
Energetics of isometric contraction in dystrophic fast and slow muscles
Authors: Nwoye L. O. , Goldspink G.
Published: January 2005

The amount of phosphoryl creatine (PC) hydrolysed during a ten‐second isometric contraction was measured in the biceps brachii (fast) and soleus (slow) muscles of adult normal and dystrophic mice (Re 129 strain) following inhibition of glycolysis and oxidative phosphorylation. The dystrophic muscles were found to have a lower isometric economy (tension‐time integral per μmol PC) than the normal muscles. This was particularly so in the case of the fast biceps brachii muscle which is affected by dystrophy to a greater extent than the slow soleus muscle. The isometric economy of the dystrophic muscles was lower even when the results were based on a total creatine rather than on a weight basis. This suggests there may be some defect in the contractile proteins of dystrophic muscle. The normal soleus muscle was found to be approximately three times more economical in maintaining tension than the normal biceps brachii muscle. This indicates the adaptation of slow muscles such as the soleus are used for maintenance of posture.
Branched‐chain ketoacids reduce muscle protein degradation in duchenne muscular dystrophy
Authors: Stewart Peter M. , Walser Mackenzie , Drachman Daniel B.
Published: January 2005

In order to determine whether branched‐chain ketoacids can reduce the excessive rate of muscle protein degradation that characterizes Duchenne muscular dystrophy, nine boys affected with the disease were studied in a metabolic ward while receiving meat‐free diets. After a three‐day equilibration period, excretion rates of 3‐methylhistidine and creatinine were measured in two consecutive four‐day periods. In the second period, a supplement containing a mixture of ornithine α‐ketoisocaproate, α‐ketoisovalerate, and α‐keto‐β‐methylvalerate in a proportion of 4 : 1 : 1 was administered orally at a dosage of 0.45 gm/kg/day. During treatment with the ketoacids, 3‐methylhistidine excretion fell by a small (mean: 14%) but highly significant (P < 0.01) extent, whether expressed in absolute terms or in relation to creatinine excretion. No adverse effects were noted. We conclude that this mixture of ketoacids acutely reduces muscle protein degradation in patients with Duchenne muscular dystrophy.
Signs of reinnervation in myasthenia gravis
Authors: Hilton‐Brown Per , Stålberg Erik V. , Osterman Per Olof
Published: January 2005

In a study of 71 patients with myasthenia gravis, the local fiber density of muscle fibers within motor units was estimated with single fiber electromyography (SFEMG). The fiber density was increased significantly in the patient group, compared to normal controls. This increase was not correlated to disease severity or duration, but was significantly higher in patients treated with cholinesterase inhibitors as compared to untreated patients. The study indicates a slight reorganization of the motor unit in untreated patients with myasthenia gravis and more pronounced changes in patients treated with cholinesterase inhibitors.
Myosin light chain components in single muscle fibers of duchenne muscular dystrophy
Authors: Takagi Akio , Ishiura Shoichi , Nonaka Ikuya , Sugita Hideo
Published: January 2005

Single muscle fibers were prepared from biopsy specimens of Duchenne muscular dystrophy (DMD), normal, and neuromuscular disease controls. Single muscle cells were classified as type 1, type 2, or intermediate by the skinned fiber method. The intermediate fiber was most abundant in DMD, comprising 29% of fibers examined. The fiber type of single muscle fibers was contrasted to the composition of myosin light chain (MLC) components, which was analyzed by micro two‐dimensional gel electrophoresis. In DMD, each of the components exhibited the same electrophoretic mobility as those in the controls. Type 1 fibers of DMD were more diverse in the composition of MLC than those of controls; 55% of type 1 fibers of DMD contained distinct fast‐type MLC 3. Some intermediate fibers contained all five MLC components, but in others the composition was not different from usual type 1 or type 2 fibers. The diversity of MLC composition in DMD muscle cells might reflect the abundance of young muscle fibers in the tissue due to active muscle regeneration andsol;or retardation of maturation.
Abnormal distribution of proteins in the soleus and extensor digitorum longus of dystrophic mice
Authors: Jasch Laura G. , Bressler Bernard H. , Ovalle William K. , Slonecker Charles E.
Published: January 2005

Proteins of the whole muscle homogenates of the slow‐twitch soleus (SOL) and fast‐twitch extensor digitorum longus (EDL) of normal and dystrophic C57BL/6J mice at 4, 8, 12, and 32 weeks of age were resolved on polyacrylamide isoelectric focusing gels. Gels of the normal SOL proteins at all ages contained two bands specific to SOL and not represented in EDL. Gels of normal EDL contained three bands highly amplified in EDL but barely detectable in SOL. The distribution of proteins in dystrophic SOL was abnormal at all age groups studied due, in part, to a decrease in the proportion of SOL‐specific proteins relative to other proteins in the muscle. The distribution of proteins in dystrophic EDL appeared abnormal first at 12 weeks due to a decrease in the relative proportion of EDL‐amplified proteins. Due to these and other changes, at 32 weeks the dystrophic SOL and EDL were almost indistinguishable on the basis of their proteins' distributions.
Congenital nemaline myopathy. I. Defective organization of α‐actinin is restricted to muscle
Authors: Jennekens Frans G. I. , Roord John J. , Veldman Henk , Willemse Jacobus , Jockusch Brigitte M.
Published: January 2005

This investigation was undertaken to find out whether the structural and biochemical changes seen in skeletal muscles in congenital nemaline myopathy (CNM) occurred also in nonmuscle cells. It was confirmed that nemaline bodies contain α‐actinin. The distribution of actin and α‐actinin in the examined nonmuscle cells was considered normal. The motility of the leucocytes and the fibroblasts was indistinguishable from that of those in normal controls. Slight changes in the peripheral nerve fibers of one patient were found, but these were not seen in another patient. The results indicate that congenital nemaline myopathy is not a generalized disorder but is restricted to skeletal muscle.
Autosomal recessive generalized myotonia
Authors: Sun Sallie F. , Streib Erich W.
Published: January 2005

Two siblings and a first degree cousin of a consanguinous marriage were afflicted with recessive generalized myotonia (RGMy). All had muscle weakness which was particularly prominent after rest, thinning of the forearms, weakness of anterior compartment muscles, and muscular contractures. The first degree cousin was the most severely afflicted with congenital myotonia. Muscle biopsy and electromyography were consistent with a myopathy. Exercise after rest demonstrated a marked reduction in muscle membrane excitability in all patients.
Schwann cell changes and demyelination in chronic galactose neuropathy
Authors: Powell H. C. , Myers R. R.
Published: January 2005

Dystrophic changes of Schwann cells and demyelination occurred in rats with chronic nerve edema induced by feeding a galactose‐rich diet for two years. The mechanism for edema is the sorbitol pathway which generates osmotically active polyols from galactose or glucose. The blood‐nerve barrier impedes diffusion of macromolecules from peripheral nerves, and endoneurial fluid pressure (EFP) becomes elevated. After 24–26 months of feeding with 40% galactose diet, myelinated nerve fibers showed segmental demyelination with bubbly disintegration of myelin sheaths, axonal degeneration, and remyelination. These pathologic changes were significantly more common than similar abnormalities in age‐matched controls. Massive glycogen accumulation in Schwann cells, a unique morphologic finding, appeared only in experimental rats. Since edema and increased EFP are the earliest pathologic changes and are present for months before demonstrable nerve fiber injury, we suggest that they are responsible for the changes of myelinated fibers in chronic galactose neuropathy.