bluuebunny/crossref_metadata_2025_split huggingface dataset:
Normal and dystrophic hamster myoblast and fibroblast growth in culture
Authors: Klamut Henry J. , Lin Chao‐Hsiung , Strickland Kenneth P. 
Published: January 2005

AbstractNormal and dystrophic hamster myoblasts and fibroblasts were compared for characteristic indicators of growth and differentiation. Clonal analysis of myoblast cultures indicated that 80% of colonies judged to be fusion‐competent had differentiated. Dystrophic myoblasts were identical to normal in terms of their morphology, fusion potential (81.4%), and myokinase activity (59.6–49.1 mU/mg at 2–7 days), but displayed a significantly higher plating efficiency (normal: 52.6%; dystrophic: 82.1%), a longer doubling time (normal: 21.7 hours; dystrophic: 33.3 hours), and a lower day‐7 creatine kinase activity (normal: 60.7 mU/mg; dystrophic: 41.3 mU/mg). Dystrophic fibroblasts were indistinguishable from normal ones in terms of their morphology, plating efficiency (90.4%), and doubling time (32.5 hours), but displayed a significantly lower day‐2 creatine kinase activity (normal 58.3 mU/mg; dystrophic: 35.8 mU/mg) and day‐7 myokinase activity (normal: 52.7 mU/mg; dystrophic: 39.9 mU/mg). The results are suggestive of an early and differential expression of the primary defect in dystrophic hamster myoblasts and fibroblasts in culture.
Improved motor response due to chronic electrical stimulation of denervated tibialis anterior muscle in humans
Authors: Valenčič V. , Vodovnik L. , Štefančič M. , Jelnikar T. 
Published: January 2005

AbstractNine patients with complete denervation of the tibialis anterior were admitted to a stimulation program in order to restore dorsiflexion of the foot. Best results were obtained with pulses of 20‐msec pulse width and 20‐msec interval. After 3 weeks of training for 2 × 20 min/day, dorsiflexion due to stimulation was increased in all patients. In some of them, gait could be improved during the swing phase using electrical stimulation. The applied training program thus reversed the course of disuse atrophy and proved the feasibility of functional electrical stimulation for patients with denervated muscles.
Compressive neuropathy in childhood: A report of 14 cases
Authors: Jones H. Royden 
Published: January 2005

AbstractDuring a 6‐year period, 14 of 898 patients examined at a pediatric electromyographic laboratory had a compressive mononeuropathy. These included five injuries to the peroneal nerve, four to the sciatic nerve, two to the distal radial nerve, and one each to the deep palmar branch of the ulnar nerve, the musculocutaneous nerve, and the long thoracic nerve. A potentially preventable mechanism was identified in 9 of the 14 patients, including prolonged posture in three of the four sciatic and two of the peroneal neuropathies. Four other mononeuropathies were secondary to pressure from an orthopedic appliance or procedure (one injury to the musculocutaneous nerve, one to the long thoracic nerve, two to the peroneal nerve).
Improvement of screening in exertional myalgia with a standardized ischemic forearm test
Authors: Sinkeler Sietze P. , Wevers Ron A. , Joosten Ed M. , Binkhorst Rob A. , Oei Lian T. , van'thof Martin A. , de Haan Anton F. 
Published: January 2005

AbstractAn ischemic forearm test with simultaneous measurement of both lactate and ammonia can be used as a screening method for myoadenlyate deaminase deficiency (MADD) and for various glyco(geno)lytic defects. A standardized and a nonstandardized test have been compared in a group of 186 patients with exertional myalgia. Standardization of the ischemic forearm test has led to greater yields of both lactate and ammonia in venous return blood of patients and controls. The sensitivity of the proposed test procedure in detecting MADD patients was 100%, whereas the specificity amounted to 98.8% among exertional myalgia patients.
Sodium channel kinetics in normal and denervated rabbit muscle membrane
Authors: Kirsch G. E. , Anderson M. F. 
Published: January 2005

AbstractThe effects of chornic denervation on sodium (Na) channels in rabbit muscle membrane were determined using intracellular microelectrodes and Vaseline gap voltage clamp techniques. The Hodgkin‐Huxley13 model was used to describe the kinetic and steady‐state parameters of channel activation and fast inactivation. Chronic (7–10 days) denervation was found to cause a decreased resting potential, lowered action potential peak, and fibrillation potentials in rabbit extensor digitorum longus (EDL) muscles. Under voltage clamp conditions, no differences were observed between denervated and normal fibers in the voltage dependence of the steady‐state Na channel activation and fast inactivation curves, or in the time course of development of fast inactivation. However, in denervated fibers, the time course of recovery from fast inactivation was approximately half that measured in normal fibers. Also, whereas depolarizing holding potentials induced a longterm inactivation to varying degrees in normal EDL fibers, denervated EDL fibers and normal soleus fibers were uniformly resistant to prolonged depolarization. These results suggest that the denervation‐induced development of spontaneous activity may be due in part to changes in the mechnisms that control the refractoriness of Na channels.
An examination of some factors influencing creatine kinase in the blood of patients with muscular dystrophy
Authors: Jackson M. J. , Round J. M. , Newham D. J. , Edwards R. H. T. 
Published: January 2005

AbstractThe natural variability of plasma creatine kinase activity has been examined in patients suffering from muscular dystrophy and in normal subjects. The coefficient of variation of the plasma creatine kinase activities was found to be large (approximately 35%) in both patients with Duchenne muscular dystrophy and normal control subjects. A comparison of the plasma activities of creatine kinase with other muscle‐derived enzymes suggests that the cause of this variability is changes in the release of enzymes from muscle. Data obtained concerning the effect of physical activity on plasma creatine kinase activity are contradictory, but several young patients with Duchenne muscular dystrophy and a very high creatine kinase activity (greater than 5000 IU/liter) showed a decreased activity following admission to hospital. An estimate of the rate of efflux of certain kinase from muscle has been made, indicating that young ambulant patients with Duchenne muscular dystrophy have a grossly elevated muscle creatine kinase efflux (495.0 ± 61.3 IU/kg muscle/hr) compared to control subjects (1.4 ± 0.5 IU/kg muscle/hr).
Calcium‐activated protease in hamster cardiomyopathy
Authors: Spalla Milena , Kuo Tuan H. , Wiener Joseph 
Published: January 2005

AbstractA high calcium‐requiring protease was purified from the hearts of myopathic hamsters. The biochemical properties of the enzyme were studied with [3H]acetylcasein as substrate. Comparison of the enzyme from hamster and rat hearts indicated no species specificity. Increased levels of the enzyme were associated with the development of cardiac lesions in myopathic hamsters.
Calmodulin levels in developing muscle tissues and primary cultures of normal and dystrophic (UM‐X7.1) Hamsters
Authors: Klamut Henry J. , Kotarba Jan A. , Strickland Kenneth P. 
Published: January 2005

AbstractCalmodulin levels have been assessed in whole muscle and primary culture extracts in order to examine the relationship between calmodulin and the accumulation of calcium in dystrophic hamster muscle tissues. Significant decreases in both normal and dystrophic skeletal muscle, tongue, and heart calmodulin levels were observed between 2 and 12 weeks of age. Dystrophic values, however, tended to be somewhat higher than normal, especially in 12‐week‐old skeletal muscle total and soluble extracts (normal 29.7 and 0.6 and dystrophic 117.0 and 3.1 μg/g wet weight, respectively). No significant differences were observed in dystrophic myoblast (total 2.22‐2.78, soluble 2.85‐3.26 μg/mg protein) or fibroblast (total 2.64‐2.94, soluble 2.54‐3.60 μg/mg protein) calmodulin levels, except for a significant decrease in dystrophic fibroblast levels (total 1.97, soluble 2.18 μg/mg protein) at 7 days in culture. Elevated calmodulin levels in dystrophic muscle are discussed in terms of increases in intracellular Ca2+ concentrations and immature regenerating fibers.
AAEE minimonograph #26: The electrodiagnosis of carpal tunnel syndrome
Authors: Stevens J. Clarke 
Published: January 2005

AbstractThe electrodiagnosis of carpal tunnel syndrome is reviewed, including discussions of old and new techniques of motor and sensory nerve conduction, anomalous innervation, needle electrode examination, and one method of examining a patient with suspected carpal tunnel syndrome. The results of electromyographic testing of 505 patients with carpal tunnel synddrome in Rochester, Minnesota, from 1961 to 1980 are compared with result from previous studies. In the appendixes, a method of performing median motor and sensory nerve conduction studies and Mayo Clinic normal values are provided.
Paramyotonia congenita: Successful treatment with tocainide. Clinical and electrophysiologic findings in seven patients
Authors: Streib Erich W. 
Published: January 2005

AbstractSeven patients with paramyotonia congenita (PC) from two families were studied. Voluntary exercise of the hand muscles was performed at different hand temperatures, both before and after treatment with tocainide. All patients developed stiffness, prolonged weakness, and small compound muscle action potentials (CMAPs) following exercise; the temperature at which this occurred was individually different. Two patients with PC and associated episodes of generalized weakness underwent potassium loading. A prolonged exercise test was performed both immediately before and 90 minutes after K‐loading. Exercise‐induced weakness and CMAP‐decline occurred only with high serum K levels. Thiazide treatment in these two patients was ineffective. All seven patients responded well to tocainide. Treatment response and side effects were dose‐dependent. Good clinical improvement has been maintained in all patients for more than 6 months, with relatively small doses of tocainide (400–1200 mg/day).
Electrocardiographic, biochemical, and morphologic abnormalities in dystrophic hamsters with cardiomyopathy
Authors: Bhattacharya Syamal K. , Crawford Alice J. , Pate James W. 
Published: January 2005

AbstractElectrocardiographic (EKG) changes were investigated in 7‐month‐old dystrophic hamsters (DH) with cardiomyopathy and were correlated with biochemical and histologic aberrations. Abnormally tall R‐I and R‐aVL amplitudes, deep S‐III and S‐aVR waves, and elongated PR‐I, QT‐I, and QRS‐I intervals (all at P <0.0001) were noted in DH compared with normal hamsters. These EKG changes are similar to those seen in Duchenne muscular dystrophy (DMD) and support cardiac hypertrophy (P < 0.001) in DH. Excessive intracellular calcium accumulation in the heart (P < 0.0001), diaphragm (P < 0.001), and rectus femoris (P < 0.05), and elevated plasma creatine kinase concentrations (P < 0.001) were also noted in DH. Histopathology in the cardiac and skeletal muscles of DH included fatty infiltration, centronucleation, and sporadic necrosis with calcium deposition. Observed EKG abnormalities, biochemical alterations, and histological aberrations in the cardiac and skeletal muscles of DH are strikingly similar to those reported in DMD and thus substantiate the relevance of DH as a suitable model for the study of muscular dystrophy and cardiac hypertrophy.
The time course of creatine kinase elevation following concentric needle EMG
Authors: Levin Randy , Pascuzzi Robert M. , Bruns David E. , Boyd James C. , Toly Travis M. , Phillips Lawrence H. 
Published: January 2005

AbstractThe electromyographic (EMG) exam and creatine kinase (CK) are commonly used to evaluate patients with neuromuscular diseases. Prior studies have demonstrated minimal elevation of CK following monopolar needle examination, indicating that a false positive elevation does not occur in normal individuals. We studied the magnitude and time course of CK change resulting from concentric (CNEMG) and monopolar (MNEMG) needle EMG examination on healthy volunteers.CK increased in all subjects following CNEMG and MNEMG. Statistically significant mean CK elevations over baseline were observed at 4, 8, 12, and 24 hours for CNEMG and at 12 and 24 hours for both MNEMG. Maximum elevation occurred at 12 and 24 hours for both CNEMG (mean, 178% of baseline) and MNEMG (mean, 134% of baseline). CK returned to baseline by 48 to 72 hours. In 25–30% of subjects CK elevation significantly exceeded the normal range.The magnitude of CK elevation is greater and the time course more prolonged than previously reported. CK measurements should be avoided 4 to 48 hours following CNEMG because of the potential for false positive results. Measurements immediately after and at 72 hours are not affected by the CNEMG or MNEMG. The time course for CK change following MNEMG is similar to CNEMG, but the magnitude is less.
High serum levels of creatine kinase: Asymptomatic prelude to distal myopathy
Authors: Galassi Giuliana , Rowland Lewis P. , Hays Arthur P. , Dimauro Salvatore , Hopkins Linton C. 
Published: January 2005

AbstractTwo brothers and an unrelated man had serum creatine kinase values of 3000–8000 units when they were asymptomatic, and there was no weakness on examination. EMG and muscle biopsy showed changes indicative of myopathy. Years later, all three developed weakness that was limited to the gastrocnemius. Because siblings were affected, the disorder can be regarded as a form of muscular dystrophy. The distribution of weakness, serum enzyme changes, and histologic changes resembled an autosomal recessive distal myopathy first described by Miyoshi and differed from many other reported cases of distal myopathy. Our cases also indicate that myopathy may be asymptomatic.
Serum creatine kinase isoenzymes in duchenne muscular dystrophy determined by sensitive enzyme immunoassay methods
Authors: Mokuno Kenji , Riku Shigeo , Sugimura Kimiya , Takahashi Akira , Kato Kanefusa , Osugi Shigeki 
Published: January 2005

AbstractSerum levels of creatine kinase (CK) isoenzymes (MM, MB, and BB) were measured by sensitive enzyme immunoassay (EIA) methods in 50 patients with Duchenne muscular dystrophy (DMD) and in 39 controls. MM, MB, and BB levels in DMD patients were higher than in controls, and these three levels decreased with advancing age of DMD patients. Serum MB levels showed a good correlation with serum levels of carbonic anhydrase III (CA‐III), but correlated poorly with electrocardiographic findings, suggesting that the main origin of serum MB in DMD is skeletal muscle rather than cardiac muscle.
Aminoglycosides and 3, 4‐diaminopyridine on neuromuscular block caused by botulinum type a toxin
Authors: Molgó Jordi , Lemeignan Madeleine , Thesleff Stephen 
Published: January 2005

AbstractImpulse‐evoked transmitter release was greatly reduced at frog neuromuscular junctions 3–20 days after botulinum type A toxin (BoTx) poisoning. The reduction in transmitter release was accompanied by an increased variability in the latency between the presynaptic spike and the release of transmitter. The aminoglycoside antibiotics amikacin, gentamycin, and bekanamycin, when applied at concentrations within their therapeutic levels, markedly enhanced the blockade of transmitter release in BoTx‐poisoned junctions. 3,4‐diaminopyridine strongly antagonized the effects of BoTx at early stages of poisoning, and the combined presynaptic effects of BoTx and aminoglycoside antibiotics provided that transmitter release was not completely blocked by the toxin. The antagonism was apparent at all frequencies of stimulation. Since the aminoglycoside antibiotics enhanced the neuromuscular block caused by BoTx, these drugs should be avoided in patients suspected of poisoning by this toxin.
Electrophysiologic evidence of severe distal nerve segment pathology in the guillain–barré syndrome
Authors: Miller Robert G. , Peterson Christina , Rosenberg Neil L. 
Published: January 2005

AbstractWe report the clinical and electrophysiologic findings in 4 patients with Guillain–Barré syndrome (GBS) who, within 48 hours of onset, progressed to flaccid quadriplegia. Evoked muscle action potentials were absent or prolonged in latency and markedly reduced in amplitude within 48 hours of onset of weakness at a time when sensory nerve studies were almost normal. We conclude that pathophysiologic abnormalities may be distal and severe in some patients with GBS and that there is a predilection for motor axons in GBS.
Increased skeletal muscle acetylcholinesterase activity in porcine malignant hyperthermia
Authors: Mickelson James R. , Thatte Hemant S. , Beaudry Terrrence M. , Gallant Esther M. , Louis Charles F. 
Published: January 2005

AbstractThe content and distribution of acetylcholinesterase (AChE) activity in the skeletal muscle disorder malignant hyperthermia (MH) was examined. The AChE activity of sarcolemma membranes isolated from MH‐susceptible (MHS) swine was increased twofold when compared with normal sarcolemma. The total AChE activity of muscle extracts was also doubled in MHS tissue; however, the relative distribution between low‐salt extractable (globular forms) and high‐salt extractable (asymmetric forms) AChE activities were similar in MHS and normal muscle. Our results suggest that, for as yet unexplained reasons, both the sarcolemmal and total AChE activity of skeletal muscle is increased in porcine MH.
Changes in contractile speed of cat motor units during activity
Authors: Dubose Laniel , Schelhorn Teresa B. , Clamann H. Peter 
Published: January 2005

AbstractExperiments were conducted to measure the extent of contractile changes during phasic activity of different motor units. Motor units of cat medial gastrocnemius were isolated and classified by their mechanical properties as fast and fatigable (FF), fast and fatigue resistant (FR), or slow (S). Single stimuli interpolated between stimulus trains of the fatigue test produced twitches whose shapes were measured at different times during this test. After 30 seconds of fatigue testing, twitch contraction times of 33% of FF units fell into the slow range, i.e., 5 of 17 units had become slower than the fastest slow units. Mean twitch contraction time of FF units increased by 11.8 msec, whereas that of S units decreased by 16.2 msec. We conclude that the mechanical properties of rested motor units change markedly with use and are a poor index for determining the contractile speed of active muscles.
A computer model of denervation‐reinnervation in skeletal muscle
Authors: Cohen Michael H. , Lester James M. , Bradley Walter G. , Brenner John F. , Hirsch Robert P. , Silber Dennis I. , Ziegelmiller Daniel 
Published: January 2005

AbstractA computer model of the process of denervation and complete reinnervation of skeletal muscle has been developed for the purpose of exploring underlying mechanisms and for use in the development of new clinical and research tools for evaluating neuromuscular disease. Progressive motor neuron death and reinnervation in this model reproduces the fiber‐type grouping, increased fiber density, and minimal increase of motor unit size seen in human chronic denervating diseases. Studies using the model suggest that (1) preferential involvement of motor units of one type could account for the abnormal fiber‐type proportions observed in some diseases, (2) reinnervation by axons innervating adjacent fibers is compatible with single fiber multielectrode studey results in that it does not produce a large increase in motor unit area, and (3) such reinnervation is sufficient to account for the increases in motor unit density that have been observed. The model has also been used in the development and testing of the Codispersion Index a measure of the codistribution of two fiber types, which is useful in detecting fiber‐type grouping.
Detection, characterization, and staging of polyneuropathy: Assessed in diabetics
Authors: Dyck Peter James 
Published: January 2005

AbstractThe reported prevalence of diabetic polyneuropathy varies from 5 to 80%. This unsatisfactory state may relate to evaluation of different patient groups, different minimal criteria for the diagnosis of neuropathy, and different degrees of surveillance. To made matters worse, patients with polyneuropathy tend to be equated ignoring differences in severity. To remedy this situation, four recommendations are made: (1) population‐based patients should be studied, (2) nerve conduction should be used to set minimal criteria for neuropathy because the test is objective, sensitive, and repeatable, (3) validated tests of symptoms and deficits should also be used because clinical manifestations of neuropathy cannot be accurately inferred from electrophysiologic measurements, and (4) approaches to staging severity of neuropathy should be developed and used in expressing abnormality. To this end minimal criteria for the diagnosis of diabetic polyneuropathy have been proposed, and validated tests to assess neuropathic symptoms and sensory deficits have been developed. In this report we also propose a staging approach utilizing nerve conduction and neurologic history and examination and validated tests of neuropathic symptoms and deficits.
Intraoperative electroneurography: Management of ulnar neuropathy at the elbow
Authors: Campbell William W. , Sahni Singh K. , Pridgeon Rhonda M. , Riaz Ghazala , Leshner Robert T. 
Published: January 2005

AbstractAt the elbow the ulnar nerve may be compressed either in the retrocondylar groove or at the cubital tunnel. Optimal surgical therapy should be directed at the specific site of involvement. Intraoperative electroneurography performed in conjunction with 19 ulnar nerve explorations helped localize the precise site of compression. Of the primary procedures, abnormality was at the retrocondylar groove in 9, cubital tunnel in 4, both locations in 3, and at an unusual distal point in 1; 12 anterior subcutaneous transpositions, 4 cubital tunnel releases, and 1 distal decompression resulted. Intraoperative studies helped identify residual compression in two patients undergoing reexploration. Although routine electrodiagnosis may localize an ulnar neuropathy to the elbow, reliably separating retrocondylar from cubital tunnel compression is more difficult. Preoperatively, percutaneous serial short increment studies were more accurate than simple “inching” in predicting the site of compression.
Protron spin‐lattice relaxation time of duchenne dystrophy skeletal muscle by magnetic resonance imaging
Authors: Matsumura Kiichiro , Nakano Imaharu , Fukuda Nobuo , Ikehira Hiroo , Tateno Yukio , Aoki Yoshiro 
Published: January 2005

AbstractBy means of proton MRI, the spin‐lattice relaxation times (T1 values) of pelvic and leg muscles were measured in Duchenne muscular dystrophy (DMD) patients and normal controls. The bound water fraction (BWF) was calculated from the T1 value obtained. In normal children, the T1 value decreased, and BWF increased with age. In DMD, the T1 value rapidly decreased, from an abnormally high value in the early stages, with the progress of the disease. This reduction of the T1 value in DMD was not the same for all muscles; it was most prominent in the gluteus maximus and least prominent in the sartorius and gracilis muscles. BWF was below normal in the early stages of DMD. It is suggested that both regenerating and degenerating muscle fibers, together with the increased muscle water content, cause the high T1 value and low BWF in the early stages of DMD, whereas replacement of muscle by fat causes the decreased T1 value in the advanced stages.