bluuebunny/crossref_metadata_2025_split huggingface dataset:
Invited review: Neural control of phenotypic expression in mammalian muscle fibers
Authors: Pette Dirk , Vrbová Gerta 
Published: January 2005

AbstractIn this review, the present knowledge about the mechanisms involved in the control of the phenotypic expression of mammalian muscle fibers is summarized. There is a discussion as to how the activity imposed on the muscle fibers by the motoneuron finally induces in the muscle cells the expression of those genes that define its particular phenotype. The functional and molecular heterogeneity of skeletal muscle is thus defined by the existence of motor units with varied function, while the homogeneity of muscle fibers belonging to the same motor unit is yet another indication of the importance of activity in the control of gene expression of the mammalian muscle fiber.
F‐waves in neurogenic atrophy
Authors: Petajan Jack H. 
Published: January 2005

AbstractF‐waves were determined in the peroneal nerves of 17 normal subjects, 11 amyotrophic lateral sclerosis (ALS) patients, and 13 patients with other disorders causing neurogenic atrophy (NA) in extensor digitorum brevis muscle. F‐waves were examined with regard to latency and waveform. Latency was increased above normal for both ALS and NA patients (P < 0.024 and P < 0.003, respectively). In normal subjects, the mean number of repeated responses (same latency and waveform) was 1.9 (r = 1.0–5.0), where 1.0 corresponds to no repeated response. In ALS patients, repeated responses were 2.9 (r = 1.2–7.8), which is not significantly different from normal (P < 0.099). In NA patients, repeated responses were 6.5 (r = 1.6–23), which is significantly above normal (P < 0.041). A dominant waveform occurred in 21.5% (mean) of responses in normal subjects (r = 4%–58%). In ALS and NA, corresponding values were 40.3% (r = 10%–88%) and 44.1% (r = 17%–100%), both of which were significantly above normal (P < 0.014 and P < 0.012, respectively). The distribution of F‐wave latencies is often nonrandom in normal, ALS, and NA subjects. The dominant F‐wave that was present in normal subjects and significantly increased in ALS and NA subjects may result from decreased numbers of motoneurons capable of contributing to the F‐response and would seem to be a useful additional measure of abnormality.
Screening for duchenne muscular dystrophy: An improved screening test for creatine kinase and its application in an infant screening program
Authors: Scheuerbrandt Günter , Lundin Arne , Lövgren Timo , Mortier Wilhelm 
Published: January 2005

AbstractA kinetic bioluminescence assay with optimized reagent conditions has been developed for application as a screening test for increased creatine kinase (CK) activities in dried blood spots. This test is used for the early detection of Duchenne muscular dystrophy (DMD) in a voluntary CK screening program in West Germany of the 176,600 boys tested up to December 31, 1984, 48 who were less than 6 months old had certain or probable DMD (frequency 1: 3679). In 1983 and 1984, the rate of false positive results was 0.016% for a cut‐off activity 300 U/liter and 0.061% for a cut‐off activity 180 U/liter. Long‐term counseling is offered to families of newly detected DMD patients in order to facilitate the aims of the screening program, namely, avoidance of secondary cases in affected families, early professional care for the sick child, and the early opportunity to make the appropriate decisions for a life with an handicapped child. Two types of a benign hereditary blood anomaly were also detected by CK screening (CK‐BB inside erythrocytes or thrombocytes).
Electromyographic findings in different forms of infantile and juvenile proximal spinal muscular atrophy
Authors: Hausmanowa‐Petrusewicz Irena , Karwańska Anna 
Published: January 2005

AbstractQuantitative electromyography (EMG) was performed in 223 infantile and juvenile cases of spinal muscular atrophy (SMA), which were classified into 3 groups: (A) form la, Werdnig‐Hoffmann disease; (B) forms lb and II, intermediate forms; and (C) form III, Kugelberg‐Welander disease. The groups differed in the occurrence of spontaneous activity; only groups A and B showed spontaneous rhythmic firing of motor units, whereas in long‐standing cases, pseudomyotonic volleys appeared. The parameters of individual motor unit potentials (MUPs) differed in the different forms of the disease. Group A showed, in addition to long potentials of high amplitude, some short and low amplitude potentials, and the histograms of amplitudes and durations were bimodal. In the long‐standing cases, the values of these parameters were shifted to longer durations and higher amplitudes of motor unit potentials. However, in long‐standing cases of the benign group C, the short, low potentials appeared as well as socalled linked potentials. In the very early stage of the disease, the children who were found to be suffering from chronic forms of SMA—both malignant (form lb and II or benign group C)—had an EMG record that was slightly different from that of acute form la. Their EMG record shows more so‐called “spinal” signs, particularly in the benign group C (Kugelberg‐Welander disease). These increasing features of chronic anterior horn cell involvement followed a pattern of reinnervation and hypertrophy of muscle fibers. These phenomena were particularly seen in the benign group C. These findings indicate that in the early stage of SMA, the EMG not only has diagnostic, but also prognostic, value.
Congenital myasthenia: Further evidence of disease heterogeneity
Authors: Lecky B. R. F. , Morgan‐Hughes J. A. , Murray N. M. F. , Landon D. N. , Wray D. , Prior C. 
Published: January 2005

AbstractThe findings in two cases of congenital myasthenia investigated by intercostal muscle biopsy are presented. The first case, a 16‐year‐old boy, showed reduced miniature endplate potential amplitude and normal 125l‐α‐bungarotoxin binding to postsynaptic acetylcholine receptors. Muscle biopsy and endplate ultrastructure were normal. Tubocurarine affinity, ion channel properties, and passive membrane properties were normal. Limited data showed reduced effectiveness of applied acetylcholine in opening ion channels. The second case was an 18‐year‐old girl with consanguineous parents. Type 2 muscle fiber atrophy was seen in both limb and intercostal muscle. Intercostal endplates were elongated, although ultrastructure was normal. Negligible postsynaptic α‐bungarotoxin binding suggested an abnormality of the acetylcholine receptor macromolecule.
Muscle stiffness and electrical activity in paramyotonia congenita
Authors: Ricker Kenneth , Rüdel Reinhardt , Lehmann‐Horn Frank , Küther Gerald 
Published: January 2005

AbstractTo investigate the pathomechanism of paramyotonic stiffness, the mechanogram of isometric finger force and the electromyogram of the flexor digitorum muscle were simultaneously recorded in five unrelated paramyotonia congenita patients. Cooling of the forearm provoked “spontaneous” electrical activity, but the accompanying force was <5% of the maximal voluntary isometric contraction amplitude. The relaxation of maximal voluntary contractions executed in the cold had a normal first phase and a very slow second phase. The force amplitude at the beginning of the slow phase was up to 80% of the maximal contraction amplitude; the duration of the slow phase was up to several minutes. It was concluded that the slowed muscle relaxation is more important as a factor contributing to paramyotonic stiffness than spontaneous force generation. Involuntary electrical activity recorded during the slow relaxation phase was too low to account for the force. Intercostal muscle biopsies obtained from four patients showed similar phases of slow relaxation when stimulated to give isometric twitches or tetani in the cold. Extracellular recording with electrodes designed to pick up all activity from the small bundles clearly showed that the slow relaxation phase was not caused by spontaneous action potentials. One possible explanation for the slowed relaxation is a long‐lasting depolarization‐induced contracture of the muscle fibers following activation in the cold.
Correlation of 1A afferent conduction with the ataxia of fisher syndrome
Authors: Weiss Jacquelyn A. , White James C. 
Published: January 2005

AbstractThe pathophysiology of the ataxia in Fisher syndrome (the syndrome of acute ophthalmoplegia, ataxia, and areflexia) has been attributed to both peripheral nervous system pathology and cerebellar system dysfunction. Pathologic studies have demonstrated no consistent central nervous system abnormalities. We present a case in which abnormalities of 1a sensory conduction were found to correlate directly with the degree of ataxia, without impairment of motor or cutaneous sensory conduction. We propose that the ataxia seen in typical Fisher syndrome may be due to demyelination of 1a afferent fibers.
Simulation and analysis of the electromyographic interference pattern in normal muscle. Part II: Activity, upper centile amplitude, and number of small segments
Authors: Nandedkar Sanjeev D. , Sanders Donald B. , Stålberg Erik V. 
Published: January 2005

AbstractWe have defined three new features of the electromyographic (EMG) interference pattern (IP): activity, upper centile amplitude (UCA), and number of small segments (NSS). These parameters were measured in simulated IPs constructed by adding together motor unit action potentials (MUAPs) recorded with a concentric needle EMG electrode. The activity increases linearly with the number of MUAP discharges to approximately 80% of its theoretical maximum value. The UCA correlates strongly with the peak‐to‐peak amplitude of the largest MUAP in the IP and the mean segment amplitude and does not depend on the discharge rate of the largest MUAPs. We infer that the UCA defines the upper limit of the peak‐to‐peak amplitude of the MUAPs contained in the IP. The NSS increases with the number of MUAP discharges, but reaches a constant value at higher MUAP discharge rates, probably because small amplitude MUAPs are masked by the large amplitude MUAPs. The potential value of these parameters in automated IP analysis is discussed.
Quantitative freeze—fracture studies of membrane changes in chicken muscular dystrophy
Authors: McLean Barbara , Mazen‐Lynch Laila , Shotton David M. , McLean Gregor A. 
Published: January 2005

AbstractMuscular dystrophy induces extensive changes in the patterning of sarcolemmal caveolae of fast‐twitch fibers from the chicken posterior latissimus dorsi (PLD) muscle, which in healthy fibers are arranged in striking bands over the myofibrillar I‐bands. In dystrophic fibers the caveolae lack this patterned arrangement, and instead are dispersed over the entire sarcolemma, are irregular in shape, and are more numerous in older birds. Quantitative analysis of these differences provides three independent numerical indices of the dystrophic state and suggests that constraints responsible for normal patterning are lost in diseased fibers. These observations support theories that defects of the muscle plasma membrane are important for dystrophic pathogenesis in contrast, the sarcolemma of slow tonic fibers from anterior latissimus dorsi (ALD) and metapatagialis latissimus dorsi (MLD) muscles have randomly dispersed caveolae whose appearance and distribution are unaffected by the disease.
Passively transferred lambert‐eaton syndrome in mice receiving purified IgG
Authors: Kim Yong I. 
Published: January 2005

AbstractPurified IgG antibodies were prepared by ion‐exchange chromatography from the plasma of a patient with nonneoplastic form of the Lambert‐Eaton myasthenic syndrome (LES). The antibodies were injected into mice with daily doses of 0.15–10 mg for 20–22 days, following which the integrity of neuromuscular transmission was assessed in vitro in phrenic nerve‐diaphragm muscle preparations. The injected animals manifested electrophysiologic features of human LES, which were characterized by: (1) dose‐dependent reduction in the quantal content of nerve‐evoked endplate potentials, (2) an abnormally small increase in the frequency of spontaneous miniature endplate potentials (MEPPs) with elevated [K+]0, and (3) normal MEPP amplitude with no evidence of postjunctional deficiency. Crude immunoglobulins (Igs) from the same patient and two LES patients with associated malignancy similarly transferred the defects in quantal transmitter release. In contrast, animals receiving Igs from control subjects or from a patient with small‐cell carcinoma of the lung manifested no functional impairment of neuromuscular transmission. Instead, the evoked release in these animals was significantly enhanced relative to that found in normal untreated mice. These results suggest that an IgG antibody produces the presynaptic impairment that is characteristic of LES and support the concept that LES with and without cancer has an autoimmune pathogenesis.
Diabetic thoracic radiculopathy: Electrodiagnostic study
Authors: Streib Erich W. , Sun Sallie F. , Paustian Frederick F. , Gallagher Thomas F. , Shipp Joseph C. , Ecklund Robert E. 
Published: January 2005

AbstractWe investigated the diagnostic value of electromyographic (EMG) examination of the anterior abdominal wall muscles (AWMS) in thoracic radiculopathy and compared it with examination of thoracic paraspinal muscles (TPSM). Technically, examination of AWMS was much easier compared to TPSM. In eight patients with thoracic diabetic radiculopathy at the level of T7‐T12, AWMS was abnormal in all and was considered to be diagnostic whereas AWMS was normal in diabetic lumbar radiculopathy, patients with diabetes mellitus without radiculopathy, patients with unspecified gastrointestinal pain, and patients with musculoskeletal‐type back pain. We conclude that EMG evaluation for possible thoracic radiculopathy should include examination of AWMS, and if abnormal, would be of great diagnostic help in patients with unspecified gastrointestinal symptoms.
Surgery for thoracic outlet syndrome may be hazardous to your health
Authors: Cherington Michael , Happer Ian , Machanic Bennett , Parry Lynn 
Published: January 2005

AbstractWe are reporting five patients who suffered serious injuries from surgery for thoracic outlet syndrome, which has been a controversial subject from many aspects. Many argue that it is much overdiagnosed and overtreated. The term „disputed thoracic outlet syndrome”︁ has recently been applied to the majority of cases in which there are little or no clinical findings. The much more rare true neurogenic thoracic outlet syndrome does have associated neurologic and electrical findings. Recently, the use and misuse of electrodiagnostic studies in the diagnosis of disputed thoracic outlet syndrome has been discussed in the literature. The cases that we are reporting are especially tragic because the elective surgeries were performed in patients who had little or no clinical abnormalities on examination prior to the surgery.
Ionic channels: II. Voltage‐ and agonist‐gated and agonist‐modified channel properties and structure
Authors: Ruff Robert L. 
Published: January 2005

AbstractThis article reviews the different forms of ionic channels: voltage‐gated, agonist‐gated, and agonist‐ and second messenger‐modified channels. The recent advances in our knowledge of the amino acid sequence of the sodium channel and the nicotinic acetylcholine receptor and the relationship of the primary structure to the channels' quarternary structure and function are discussed.
Thalidomide neuropathy: An electrophysiologic study
Authors: Lagueny Alain , Rommel Antoine , Vignolly Bernard , Taieb Alain , Vendeaud ‐busquet Marie , Doutre Marie S. , Julien Jean 
Published: January 2005

AbstractThalidomide is effective in the treatment of such disabling dermatologic diseases as aphthosis, discoid lupus erythematosus, and prurigo nodularis, in which other drugs fail. However, its use can induce neuropathy necessitating caution in its administration. It was found in this electrophysiologic study of 13 patients that the data best revealing neuropathy, even when clinical abnormalities were not apparent, were reduction of sensory nerve action potential amplitude on the sural nerve, increase of somatosensory evoked potential latency following sural nerve stimulation, and reduction of sensory action potential amplitude on stimulating the median nerve at the wrist. In two patients, electrophysiologic abnormalities had increased after withdrawal, suggesting a prolonged action of thalidomide. Timely reduction of dosage, after detection of changes indicating the onset of side effects, could reduce the risk of the sometimes rapid emergence of clinical symptoms.
Studies on the pathogenesis of vincristine‐induced neuropathy
Authors: Sahenk Zarife , Brady Scott T. , Mendell Jerry R. 
Published: January 2005

AbstractThe pathogenesis of the peripheral neuropathy induced by vincristine is poorly understood, but interference of vinca alkaloids with microtubule assembly suggests that microtubule changes could be important. This possibility was studied by directly exposing the rat sciatic nerve to graded concentrations of vincristine sulfate. Microtubule length histograms prepared from randomly selected axons showed a unimodal distribution in vincristine and control axons. In vincristine‐exposed axons, however, there was a shift to shorter length microtubules, and the mean measured length of microtubules (0.42 ± 0.37 μm) was significantly (P < 0.001) shorter than controls (0.67 ± 0.55 μm). On cross‐sections, the vincristine‐exposed axons showed a decrease in the number of microtubules per square micrometer of axonal area compared to controls. These findings fit best with a loss of portion(s) of each microtubule and support the possibility that microtubules consist of both stable and labile segments. The microtubule changes were associated with malorientation of microtubules and neurofilaments, accompanied by free vesicle accumulation and fragmentation of the smooth endoplasmic reticulum. These structural alterations would account for the previously observed abnormalities in axoplasmic transport and would also provide insight into the commonly observed peripheral neuropathy induced by vincristine treatment.
Slow‐type C‐protein in dystrophic chicken fast pectoralis muscle
Authors: Obinata Takashi , Shinbo Kazuhiko 
Published: January 2005

AbstractC‐protein isoform expression in hereditary dystrophic chicken skeletal muscle was compared with that in normal chicken muscle during postnatal development by immunocytochemical and immunoblot methods. In the pectoralis muscle (PM) of both normal and dystrophic chicken, slow‐ and fast‐type C‐proteins were coexpressed in the vast majority of myofibers at neonatal age, but the slow C‐protein disappeared, leaving continued expression of only the fast‐type C‐protein as muscle development progressed up to 2 weeks posthatch. In the dystrophic chicken PM, however, myofibers containing slow‐type C‐protein reappeared about 1 month posthatch and increased in number with the progression of muscular dystrophy. We conclude that C‐protein isoform expression in dystrophic myofibers resembles that in neonatal myofibers and that the expression of slow‐type C‐protein can be seen as a marker for chicken muscular dystrophy.
Recent views on amyotrophic lateral sclerosis with emphasis on electrophysiological studies
Authors: Bradley Walter G. 
Published: January 2005

AbstractPeripheral electrophysiological studies are of particular value for elucidating the anatomy and pathophysiology of neuromuscular diseases, but they can also help in providing clues to the etiology of the disease. Recent studies of the motor units in chronic denervating conditions including amyotrophic lateral sclerosis (ALS) are reviewed. These indicate that reinnervation is a relatively active process which compensates for the progressive loss of motoneurons in ALS until more than 50% of the motoneurons have died. There seems to be no predilection for death of motoneurons of any particular size in ALS. Fasciculations may arise both proximally and distally. The dying‐back change is not a major feature of ALS. These and other data cast doubt on the etiological theories that ALS arises from premature aging of motoneurons, deficiency of motoneuron trophic factors, or an inhibitor of a motoneuronal sprouting factor, and point to the need to study metabolic changes intrinsic to the motoneuron in ALS.
Hormonal control of muscle growth
Authors: Florini James R. 
Published: January 2005

AbstractIn muscle of whole animals, pituitary growth hormone, the thyroid hormones, and insulin are major growth‐promoting hormones, and the glucocorticoids have significant catabolic actions. At the cellular level the primary anabolic hormones for cultured myoblasts are the somatomedins (insulin‐like growth factors) and fibroblast growth factor. In these cells physiological concentrations of growth hormone, thyroid hormones, and insulin have no growth‐promoting effect; some of the reported actions of insulin probably result from cross‐reaction with the somatomedin receptor. Results with purified proteins do not support the view that mitogens block myoblast differentiation; transforming growth factor‐beta and interferon are nonmitogenic proteins that inhibit differentiation, insulin‐like growth factors are mitogens that stimulate differentiation, and fibroblast growth factor is the only purified mitogen that inhibits differentiation. At least six serum‐free media have now been devised for the growth of various kinds of muscle cells under closely defined conditions.
Pedictors of patients' expreience of pain in EMG
Authors: Khoshbin Shahram , Hallett Mark , Lunbeck Robert 
Published: January 2005

AbstractThe important features that predict the amount of pain experienced by patients with low back pain who undergo needle electromyography were the patients' assessment of their own pain, their trait‐anxiety levels, and female sex. Although it does not influence EMG pain, information about the test will decrease the anxiety of patients coming for testing.
Sympathetic skin response in diabetic neuropathy
Authors: Soliven Betty , Maselli Ricardo , Jaspan Jonathan , Green Andrew , Graziano Hank , Petersen Michele , Spire Jean‐Paul 
Published: January 2005

AbstractThe sympathetic skin response (SSR) was studied in 47 diabetic patients selected for the presence of symptoms and clinical signs of peripheral neuropathy and in 24 normal control subjects. The SSR was present in all controls but was absent at the foot in 66% and at the hand in 27.7% of the diabetic patients. Absence of the SSR failed to correlate with other electrophysiologic parameters on routine nerve conduction and electromyographic studies. Although absent SSR was more often found in patients with symptoms of autonomic dysfunction (P < 0.05), there was no correlation with any specific symptoms of autonomic involvement. The SSR was frequently absent, at least in the foot, in those patients with abnormal cardiac beat‐to‐beat variability (expiratory: inspiratory, E:I, ratio) and pupil cycle time (PCT). In addition there was a good correlation between the amplitude of the SSR and the value of the E:I ratio (r = 0.81,P < 0.001). The SSR may be a valuable adjunct in the assessment of autonomic involvement in diabetic neuropathy, but its sensitivity requires further evaluation.