bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prejunctional regulatory actions of androgens on a hormone sensitive muscle
Authors: Yamamoto Lücia Akie , Lapa Antonio José , Souccar Caden 
Published: January 2005

AbstractThe influence of androgens and time course of effects induced by hormone deprivation were examined on the spontaneous transmitter re‐ lease in the levator ani (LA) muscle of 30–180‐day‐old male rats. The resting membrane potential (RMP) and miniature endplate potentials (mepps) were recorded intracellularly from LA muscle fibers of intact animals or gonadectomized at different ages. In intact animals, the frequency of mepps increased proportionately to the muscle fiber growth up to 60 days, stabilizing thereafter. Gonadectomy at any age did not affect the RMP, but increased the frequency of mepps by 65% to 140%. The effect was detected after 15 days and was unrelated to the degree of muscle atrophy. Independently of the age of gonadectomy control values of mepp frequency were restored after 90 days, while the accompanying postjunctional changes persisted. These results indicate that androgens exert a prejunctional inhibitory influence on the spontaneous transmitter release in the rat LA muscle. The transient nature of the prejunctional effect induced by hormone deprivation indicates an adjustment of nerve terminals to persistent postjunctional alterations. © 1994 John Wiley & Sons, Inc.
Ekbom's syndrome: Lipomas, ataxia, and neuropathy with MERRF
Authors: Calabresi Peter A. , Silvestri Gabriella , DiMauro Salvatore , Griggs Robert C. 
Published: January 2005

AbstractA 66‐year‐old woman with hereditary deafness and multiple symmetric lipomas presented with ataxia, slight myopathy, and neuropathy. Molecular genetic analysis of mitochondrial DNA revealed the adenine to guanine transition at position 8344 in the tRNA gene for lysine that has been associated with the myoclonic epilepsy and ragged red fiber (MERRF) syndrome. The deafness was transmitted by the patien's father and may have been an unrelated autosomal defect rather than a paternally transmitted mitochondrial point mutation. © 1994 John Wiley & Sons, Inc.
Intestinal pseudo‐obstruction in adult spinal muscular atrophy
Authors: Ionasescu Victor , Christensen James , Hart Michael 
Published: January 2005

AbstractA 42‐Year‐old woman sith negative family history had the insidious onset of weakness in her lower extremities 8 years before, in 1983. The disorder slowly progressed to include cramps and muscle twitches. The diagnosis of adult spinal muscular atrophy (SMA) was made when electromyography showed large rapidly firing motor unit potentials, positive waves, and fibrillation potentials, and when muscle biopsy of the quadriceps revealed severe alterations consistent with neurogenic atrophy. The patient also had severe chronic constipation for many years. More recently she had developed unremitting diarrhea. Gastrointestinal studies showed no evidence of peristaltic contractions in the rectum, delayed gastric emptying, and abnormal jejunal manometry with altered propagation of the migrating myoelectrical complex. © 1994 John Wiley & Sons, Inc.
Repetitive nerve stimulation studies in the Lambert–Eaton myasthenic syndrome
Authors: Tim Richard W. , Sanders Donald B. 
Published: January 2005

AbstractWe compared changes in amplitude and area of surface recorded compound motor action potentials (CMAPs) during 20‐Hz repetitive nerve stimulation and after maximum voluntary contraction in patients with the Lambert–Eaton myasthenic syndrome (LEMS), myasthenia gravis (MG), and normal controls. There was greater potentiation of CMAP amplitude after voluntary contraction than during 20‐Hz stimulation in 10 of 14 LEMS patients; CMAP area increased more after exercise than during 20‐Hz stimulation in all LEMS patients. Although abnormal potentiation of CMAP area and amplitude was seen in equal numbers of LEMS patients, more LEMS patients demonstrated a greater than 100% potentiation of CMAP area than of CMAP amplitude. We conclude that maximum voluntary contraction is preferable to brief 20‐Hz RNS to demonstrate potentiation in LEMS because it is at least as sensitive and is less painful. Measurement of CMAP area in LEMS patients is not better than measuring the change in CMAP amplitude in demonstrating abnormal potentiation. Testing of a single hand muscle for potentiation in LEMS does not demonstrate abnormal potentiation in all LEMS patients. © 1994 John Wiley & Sons, Inc.
Ion channels in a skeletal muscle cell line from a Duchenne muscular dystrophy patient
Authors: Caviedes Raul , Caviedes Pablo , Liberona Jose L. , Jaimovich Enrique 
Published: January 2005

AbstractA cell Iine (RCDMD), derived from a muscle biopsy taken from a 7‐yearold patient with Duchenne muscular dystrophy (DMD), was established in vitro using conditioned media from the UCHT1 thyroid cell line as described elsewhere (Biochim Biophys Acta 1992;1134:247–255). Unlike other cell lines established by the same procedure, RCDMD cells were highly refractory to transformation and the resulting cell line grew slowly with a doubling time of approximately 72 h. Further, cells continue to grow after more than 20 doublings and 15 passages. Some of the characteristics of the cell line include lack of reaction with antidystrophin antibodies and the presence of receptors for the dihydropyridine PN200‐110 (Kd) = 0.3 ± 0.05 nmol/L and Bmax = 1.06 ± 0.03 pmol/mg protein and for α‐bungarotoxin (Kd = 1.02 ± 0.17 nmol/L and Bmax = 4.2 ± 0.37 pmol/mg protein). Patch clamped cells in the voltage clamp configuration lack ion currents when growing in complete medium with high serum, but they can be induced to differentiate by serum deprivation and addition of hormones and trace elements. After 5 days in differentiating medium, noninactivating, delayed rectifier potassium currents are seen. At day 12, A‐type, inactivating potassium currents as well as transient inward currents are seen. In conditions in which sodium and potassium currents are absent, a very fast activating and fast inactivating calcium current was evident. The cell line offers the possibility of studying cellular mechanisms in the pathophysoplogy of DMD. © 1994 John Wiley & Sons, Inc.
Influence of recording site on CMAP amplitude and on its variation over a length of nerve
Authors: van Dijk J. Gert , van der Kamp Wim , van Hilten Bob J. , van Someren Paul 
Published: January 2005

AbstractThe distinctions between blocking, abnormal temporal dispersion, and normal conduction require delineation of the normal change in amplitude of the compound muscle action potential (CMAP) over a length of nerve. Effects of the recording site on CMAP amplitude and on its variation were studied in median and ulnar nerves of 13 healthy subjects. CMAPs were recorded from three sites: halfway along the muscles and 1 cm distal and proximal. Elbow–wrist amplitude percentages (CMAP%) were calculated. CMAP amplitudes varied considerably between sites and subjects. Amplitudes were maximal at the middle site in only 16 of 26 nerves. The site of maximal amplitude could not be identified on the basis of thumb anatomy. CMAP% was not related to CMAP amplitude, and differed by up to 32% between adjacent sites. CMAP formation involves spatial factors (electrode site, limb position, and limb anatomy), temporal factors (dispersion), and their interaction, explaining why CMAP% can exceed 100%. The site of the recording electrode affects CMAP amplitude and CMAP% to clinically relevant degrees. Standardisation of the recording site may improve reliability of CMAP% studies. © 1994 John Wiley & Sons, Inc.
The biphasic morphology of voluntary and spontaneous single muscle fiber action potentials
Authors: Dumitru Daniel , King John C. , van der Rijt William , Stegeman Dick F. 
Published: January 2005

AbstractThe extracellular morphology of single muscle fiber action potentials (SMFAPs) is anticipated by volume conductor theory to be triphasic. Single muscle fiber action potentials recorded during single muscle fiber studies (500 Hz to 20 kHz) usually appear triphasic; however, when recorded with an open bandwidth (1 Hz to 20 kHz) they are found to be biphasic. Fibrillation potentials recorded with a single fiber electrode and open bandwidth have identical biphasic morphologies as volitional SMFAPs. Computer simulations suggest that the intracellular action potential models currently used to derive simulated extracellularly recorded SMFAPs must have the repolarization phase considerably prolonged to yield the clinically recorded potentials. This implies that either the models presently used require significant modification, or there is some distortion of the transmembrane source current induced in needle recording studies such that biphasic and not triphasic potentials are detected. © 1994 John Wiley & Sons, Inc.
Putative effects of nerve extract on carbonic anhydrase III expression in rat muscles
Authors: Milot Julie , CǒTé Claude H. , Tremblay Roland R. 
Published: January 2005

AbstractCarbonic anhydrase III (CA III), the predominant CA isoform in skeletal muscle is very sensitive to neuronal influences. We aimed to determine whether CA III expression could be influenced by neurotrophic factor(s) present in sciatic nerve extract (SNE). Intact muscles were thus compared with denervated soleus (SOL), extensor digitorum longus (EDL), and tibialis anterior (TA) muscles injected daily for 7 days with saline solution (SS) or with SNE. CA III activity was significantly increased in SS‐treated EDL and TA muscles compared to control (CTR), while SNE injections partially prevented this increase. There was no significant difference for CA III activity in the SOL between CTR, SS, and SNE groups. The CA III mRNA increase observed in response to denervation was reduced by 40% in SNE‐treated EDL and TA muscles. While SOL CA III mRNA level was not affected by denervation, a 52% decrease was observed with SNE. We concluded that neuronal modulation of CA III expression in type II fibers may involve a neurotrophic component. © 1994 John Wiley & Sons, Inc.
The all ulnar motor hand without forearm anastomosis
Authors: Sachs George M. , Raynor Elizabeth M. , Shefner Jeremy M. 
Published: January 2005

AbstractAnomalous ulnar innervation of intrinsic hand muscles, inferred in a number of clinical series, has been documented only rarely in electrophysiological studies. Using near‐nerve and standard conduction studies we evaluated 2 cases with nearly exclusive ulnar innervation of hand muscles. There was no evidence of anomalous communication in the forearm. Digital sensory fibers were normally distributed in median and ulnar nerves. The anomalous motor innervation most likely results from palmar communication between ulnar and median branches (Riche‐Cannieu anastomoses). The normal distribution of digital afferents suggests that such anastomoses are formed primarily by motor axons.© 1995 John Wiley &Sons, Inc.
Electrodiagnostic evaluation of fecal incontinence
Authors: Cheong Denis M. O. , Vaccaro Carlos A. , Waxner Steven D. , Salanga Virgilio D. , Phillips Reginald C. , Hanson Maurice R. 
Published: January 2005

AbstractThe aim of this study was to assess the utility of electrodiagnostic testing (EDT) for the evaluation of fecal incontinence (FI). Over a 5‐year period, 225 patients (174 females) with FI were prospectively studied with anal manometry, anal ultrasonography, anal electromyography (AEMG), and pudendal nerve terminal motor latency (PNTML) assessment. The mean age was 60 (range 12–94) years. Causes of FI identified by clinical evaluation were obstetric injuries (45), rectal prolapse (43), iatrogenic or other trauma (42), neurologic disease (23), and idiopathic (72). EDT revealed abnormalities in 76% of patients. The incidence of pudendal neuropathy (PN) was 36% (bilateral 21%, unilateral 15%). Patients with PN were older than were those with normal PNTML (mean 71 vs. 63 years; P < 0.002). No relationship between squeeze pressure and PN could be demonstrated (P = 0.9). Reduced motor unit potential (MUP) recruitment on AEMG was present in 60% and was associated with decreased squeeze pressure (P < 0.001) and increased MUP polyphasia (P < 0.001). Concurrence of AEMG and anal ultrasonographic findings was observed in 35 of 41 patients (84%). Defects were overlooked in one study but identified by the other on three occasions, each. Moreover, 8 of 22 patients with demonstrated sphincter defects had unsuspected PN or extensive sphincter injury on AEMG that precluded sphincter repair. In conclusion, EDT proved to be a valuable tool in the evaluation and subsequent treatment of patients with FI. © 1995 John Wiley & Sons, Inc.
Neurological multisystem manifestation in multiple symmetric lipomatosis: A clinical and electrophysiological study
Authors: Naumann Markus , Schalke Bertold , Klopstock Thomas , Reichmann Heinz , Lange Klaus W. , Wiesbeck Gerhard , Toyka Klaus Viktor , Reiners Karlheinz 
Published: January 2005

AbstractMultiple symmetric lipomatosis (MSL) is characterized by a typical neck and shoulder distribution of subcutaneous lipomata and is often associated with polyneuropathy. Occasionally, the central nervous system (CNS) can be involved. Twelve of 14 patients in this retrospective study had clinical or electrophysiological evidence of a predominantly axonal polyneuropathy. Among those were 10 with alcohol abuse, but 2 patients without alcohol abuse also showed clinical or electrophysiological polyneuropathy. Clinical CNS involvement was present in 4 patients. CNS dysfunction was documented by evoked potentials in 8 subjects [prolonged latency or low amplitude of the motor response following cortical magnetic stimulation (4 patients), abnormal visually evoked potentials (4 patients) or somatosensory evoked potentials (SEP) (4 patients)]. These findings were compared to 10 chronic alcoholics without clinical signs of MSL. Five of these showed mild sensory neuropathy. Additionally, 2 also had delayed SEP latencies. Motor evoked potentials were normal in all controls. We propose that the multisystem involvement in MSL demonstrated here cannot be attributed to alcohol abuse alone. Biochemical studies have suggested mitochondrial dysfunction as the basis of the widespread neurological pathology in MSL. © 1995 John Wiley & Sons, Inc.
Myophosphorylase deficiency associated with rhabdomyolysis and exercise intolerance in 6 related charolais cattle
Authors: Angelos S. , Valberg S. J. , Smith B. P. , McQuarrie P. S. , Shanske S. , Tsujino S. , DiMauro S. , Cardinet G. H. 
Published: January 2005

AbstractA Charolais calf presented to the Veterinary Medical Teaching Hospital with a history of recumbency following forced exercise. The calf was unable to stand, and had severe rhabdomyolysis, dehydration, and electrolyte imbalance. Blood selenium concentrations were within normal limits. A complete absence of histochemical staining for phosphorylase was apparent in muscle biopsies. Five other animals in the herd also had exercise intolerance and had a complete absence of phosphorylase staining in muscle biopsies. Biochemical analyses confirmed a deficiency of myophosphorylase (range 0–0.3 μmol/g per minute: normals 15–27) with normal to slightly elevated muscle glycogen concentrations. Pedigrees from all affected animals showed a common ancestor on the sire's and dam's side of each phosphorylase‐deficient animal, suggesting an autosmal recessive transmission. Although myophosphorylase deficiency was described in humans (McArdle's disease) over 40 years ago, these cattle represent the first animal model for this disease. © 1995 John Wiley & Sons, Inc.
A quantitative study of the pancuronium antagonism at the motor endplate in human organophosphorus intoxication
Authors: Besser Roland , Gutmann Ludwig 
Published: January 2005

AbstractNine patients with organophosphorus (OP) intoxication developing neuromuscular transmission defects were given pancuronium 1, 2, or 4 mg intravenously (IV). Thirteen patient controls with hypoxic encephalopathy received similar dosages. The responses were monitored electrophysiologically using single and repetitive nerve stimulation (20 and 50 Hz). In OP patients, pancuronium did not alter the amplitude of the single CMAP, whereas its repetitive discharges were reduced. Severe neuromuscular blocks were reversed only partially by pancuronium 4 mg. In less severe blocks, 1 and 2 mg resulted in marked improvement. In the patient controls, pancuronium 4 mg induced a severe neuromuscular block but not with 1 and 2 mg. Pancuronium dosages necessary to reverse severe OP‐induced neuromuscular blockade produce a neuromuscular block when AChE activity is normal. Low dosages have little effect on normal neuromuscular transmission, but improve the block to a mild degree and may be useful as part of treatment in OP intoxications. © 1995 John Wiley & Sons, Inc.
A fractal characterization of the type II fiber distribution in the extensor digitorum longus and soleus muscles of the adult rat
Authors: Arsos George A. , Dimitriu Petros P. 
Published: January 2005

AbstractA method is proposed for the quantitative characterization of fiber type spatial distribution by means of the (correlation) fractal dimension. The method is applied to type II fiber distributions of the soleus and extensor digitorum longus muscles of the adult rat. The results obtained suggest that these distributions have fractal properties with a strong tendency for spreading, more pronounced in soleus muscle. The density of muscle fibers or the age do not seem to alter the features of the distribution. Computer‐generated random patterns have virtually the same fractal dimension as the extensor digitorum longus distributions but fail to approximate those of the soleus muscle. This fractal method could find application as an alternative in the quantitative assessment of the fiber type grouping. © 1995 John Wiley & Sons, Inc.
A new approach to motor unit estimation with surface EMG triggered averaging technique
Authors: Shahani Bhagwan T. , Fang Jianjun , Dhand Upinder K. 
Published: January 2005

AbstractA new method for estimating the number of motor units using a surface EMG triggered averaging technique is described. This method provides an estimation of mean motor unit potential (MUP) amplitude at different leveles of contraction, which can be utilized to estimate the number of motor units in a given muscle. Motor unit count estimated in abductor pollicis brevis (APB) muscle of 11 normal healthy subjects ranged from 131 to 371 with a mean of 246 ± 68. In our preliminary study of patients with lower motor neuron lesions, there was a significant reduction in the number of motor units. We believe our new noninvasive method of motor unit counting is a relatively simple and reproducible physiological technique.© 1995 John Wiley &Sons, Inc.
Sources of error in the spike‐triggered averaging method of motor unit number estimation (MUNE)
Authors: Bromberg Mark B. , Abrams Judith L. 
Published: January 2005

AbstractMotor unit number estimation (MUNE) is an electrophysical technique to estimate the number of motor units innervating a muscle or muscle group. MUNE may be useful as a measure of progression of lower motor neuron loss in amyotrophic lateral sclerosis (ALS). Several methods of MUNE have been developed. The spike‐triggered averaging method can be readily performed on EMG machines with signal averaging capabilities and is suitable for estimating the number of motor neurons innervating proximal muscles. We have used MUNE as a measure of disease state in a drug efficacy trial for ALS. From our experience with this method we have identified sources of error which can affect MUNE accuracy. We have investigated these sources and report their effect on MUNE.© 1995 John Wiley & Sons, Inc.
Decreased heart rate variability in amyotrophic lateral sclerosis
Authors: Pisano Fabrizio , Miscio Giacinta , Mazzuero Giorgio , Lanfranchi Paola , Colombo Roberto , Pinelli Paolo 
Published: January 2005

AbstractAutoregressive spectral analysis of heart rate variability (HRV) was performed in 29 patients with amyotrophic lateral sclerosis (ALS) and 33 age‐matched healthy subjects to evaluate the involvement of the autonomic nervous system. HRV analysis provides a means to recognize low (LF) and high (HF) frequency components, respectively mediated by sympathetic and parasympathetic heart control. An increase in the mean heart rate at rest (P< 0.001), a decrease in standard deviation of R‐R interval as well as in PNN50 (P< 0.001), and an increase in the LF/HF component ratio (P< 0.01) were found in the ALS patients, indicating a vagal–sympathetic imbalance. These alterations were not related to the clinical features and to the duration of the disease. Our results suggest a subclinical involvement of the autonomic nervous system in ALS, particularly affecting parasympathetic cardiovascular control. © John Wiley & Sons, Inc.
Comparison of contractile properties between developing and regenerating soleus muscle: Influence of external calcium concentration upon the contractility
Authors: Louboutin Jean‐Pierre , Fichter‐Gagnepain Valerie , Noireaud Jacques 
Published: January 2005

AbstractIn newborn rat skeletal extensor digitorum longus (EDL) muscle, it has been found that an influx of calcium from the extracellular medium is necessary for contraction, in contrast to the situation observed in adult EDL muscle. The aim of the present study was to determine the influence of the extracellular calcium concentration ([Ca]o) upon the contractile responses elicited in developing as well as in regenerating (notexin‐injected) soleus (SOL) muscle. A morphological study was performed to follow the steps of postnatal development and regeneration in SOL muscle. In nominally calcium‐free solution, the amplitudes of the twitch and tetanic tensions were greatly reduced in 1–14‐day‐old developing SOL muscles, as well as in notexin‐injected SOL muscles. With longer times after birth, twitch and tetanic tensions of SOL muscle were less affected by the absence of calcium. This contrasts with notexin‐injected SOL muscle in which the amplitudes of the contractions remained strongly dependent on [Ca]o. The present finding suggests that some functional characteristics are different in regenerating muscle fibers and may be of interest in the evaluation of the contractile properties of muscles in which injections of genetically engineered or not autologous myoblasts or viral vector have been performed. © John Wiley & Sons, Inc.
Correlates of mototr unit size, recritment threshold, and h‐refles jitter
Authors: Jabre Joe F. , Rainville James , Salzsieder Byron , Smuts Johnnes , Limke Janet 
Published: January 2005

AbstractThe aim of this research was to study the neurophysiology of the anterior horn cell (AHC) using single‐fiber EMG (SFEMG) study of the flexor carpi radialis (FCR) H‐reflex. Twelve men and 7 women, ages 20–80 years, were studied. The mean H‐jitter was 138 ± 59 μs. H‐jitter increased with age (while the M‐jitter did not) and was greater in men than in women. There was a direct correlation between the H‐jitter and H‐latency which was used as an indirect measure of the AHC's size. Given that small AHCs have a higher input resistance than large ones, the H‐jitter can be used as an indirect indicator of the AHC's input resistance and therefore its size. When subjects fell asleep, the H‐jitter increased over tenfold the baseline value, reising the possibility of an alternative, oligosynaptic pathway. H‐reflex jitter studies provide a useful clinical neurophysiological tool for the study of AHC physiology. © John Wiley & Sons, Inc.