bluuebunny/crossref_metadata_2025_split huggingface dataset:
Posterior interosseous syndrome revisited
Authors: Carfi Joseph , Ma Dong M. 
Published: January 2005

AbstractThe question of how the supinator syndrome and the posterior interosseous syndrome are (or are not) related has not been well discussed in the literature. The anatomy of the radial nerve and its innervations is quite variable, as are the etiology, presentation, and clinical findings in the lesions of the posterior interosseous nerve. The present study was based on a retrospective review of the electrodiagnostic records of 12 patients with involvement of the deep radial nerve (posterior interosseous nerve) diagnosed at the EMG lab of New York University Medical Center from 1975 to 1983. Two‐thirds of these patients had electrophys iologic abnormalities of the supinator muscle, and in the remainder, the supinator was not involved. All superficial radial nerves had normal evoked mode action potential amplitudes and latencies. We propose that the supinator syndrome is a special case of the posterior interosseous syndrome.
Cultured rat spinal cord neurons: Interaction with motor neuron disease immunoglobulins
Authors: Digby John , Harrison Roger , Jehanli Ahmed , Lunt George G. , Clifford‐Rose F. 
Published: January 2005

AbstractConditions have been developed for the culture of rat spinal cord neurons in serum‐free media supplemented with hormones and growth factors. Neurons were identified by immunofluorescence‐labeled antineurofilament antibody, and their growth was monitored by assay of choline acetyltransferase and cholinesterase activities. Activities of these enzymes were considerably higher than those of comparable cultures in serum supplemented media in which there were visibly many more nonneuronal cells. Serum immunoglobulins from patients with motor neuron disease showed enhanced binding to rat spinal cord cells maintained in both serum‐supplemented and serum‐free media, as compared with those from normal healthy individuals. Enhanced binding was more marked with the latter cells, presumably because of the higher proportion of neuronal cells in these cultures. Serum immunoglobulins from patients with other neurologic disorders showed a similar binding to that of the normal controls. The results demonstrate the presence of an immune response to spinal cord cell membrane components in patients with motor neuron disease, although whether the response is primary or secondary in the disease process remains unclear.
Neonatal spinal muscular atrophy presenting as respiratory distress: A clinical variant
Authors: Schapira D. , Swash M. 
Published: January 2005

AbstractRespiratory distress from diaphragmatic and intercostal muscular weakness was the presenting feature of two neonates with progressive spinal muscular atrophy, leading to death in the first 2 months of life. This atypical feature provides evidence of heterogeneity within the commonly used clarification of type 1 spinal muscular atrophy.
Morphometric studies of normal sural nerves in children
Authors: Ferriere Gerard , Denef Jean‐François , Rodriguez Jorge , Guzzetta Francesco 
Published: January 2005

AbstractQuantitative histologic studies of biopsies of normal sural nerves were performed on nine children aged 4 days to 17 years. Stereologic computerized procedures were used to determine total endoneurial area, size distribution and number of myelinated, unmyelinated fibers and Schwann cell nuclei per nerve and per square millimeter, and the ratio of myelin thickness to axonal diameter. There was an inverse linear relationship between the number of myelinated fibers per square millimeter and increasing age. A stronger correlation was found between the number of Schwann cell nuclei per nerve (P < 0.01) and per square millimeter (P < 0.001) and the logarithm of age. The slope of myelin thickness/axon diameter regression lines (P < 0.001) changed with age in linear relationship (correlation coefficient: P < 0.001). There were no age‐dependent changes in the number and density of unmyelinated fibers, but the number of unmyelinated axons per Schwann cell subunit decreased with age. Size distribution histograms for myelinated fibers showed a unimodal profile in the newborn. A second peak at 6–7 m̈m appeared at age 3 months, shifting progressively to 9–11 m̈m at 14 years. The distribution of unmyelinated fibers was unimodal, with a peak around 0.8 m̈m, irrespective of age. There were marked individual variations in endoneurial area.
Familial amyloid polyneuropathy
Authors: Koeppen Arnulf H. , Mitzen Edward J. , Hans Mary B. , Peng Shi‐Kaung , Bailey Ronald O. 
Published: January 2005

AbstractAmyloid fibrils were isolated from the myocardium of two patients with familial amyloid polyneuropathy. The solubilized amyloid fibril whole protein shared immunologic determinants with normal human serum prealbumin (transthyretin), but revealed subtle differences on immunoelectrophoresis and radial immunodiffusion. On sodium dodecyl sulfate‐polyacrylamide gel electrophoresis, amyloid fibril whole protein was resolved into numerous bands that reacted with antitransthyretin on immunoblots. The whole protein also contained peptide fragments of fibronectin, but was devoid of amyloid P protein. An antiserum raised against the whole protein was suitable for immunocytochemistry of amyloid in paraffin sections. In contrast, commercial antitransthyretin, raised against the intact tetrameric protein failed to react with tissue amyloid. Immunochemical and immunocytochemical results support the concept that familial amyloid polyneuropathy with cardiomyopathy is due to infiltration of susceptible tissues by an anomalous transthyretin.
Simultaneous measurement of muscle conduction velocity and emg power spectrum changes during fatigue
Authors: Eberstein Arthur , Beattie Bradley 
Published: January 2005

AbstractMuscle conduction velocity and mean frequency of the electromyogram (EMG) spectrum were measured simultaneously in the biceps brachii muscles of nine healthy subjects during sustained isometric contraction. Recordings were made at 60% and 70% of the maximum voluntary contraction In all subjects, both conduction velocity and mean frequency decreased during the time period of the fatiguing contractions. Also, the muscle conduction velocity was found to vary linearly with the mean frequency. This demonstrates that the EMG spectral shifts observed during muscle fatigue are due to slowing of the conduction velocity.
Plasma creatine kinase changes after eccentric and concentric contractions
Authors: Newham D. J. , Jones D. A. , Edwards R. H. T. 
Published: January 2005

AbstractThis study was undertaken to determine whether the large delayed creatine kinase (CK) rise, previously only reported in normal subjects after stepping exercise, was caused by the eccentric or concentric contractions. On separate occasions, five normal subjects performed the same amount of total work by walking either up (mainly concentric contractions) or down (mainly eccentric contractions) a treadmill inclined at 13°. After uphill walking, peak plasma CK values of 60–200 IU/liter occurred 24 hours after exercise. Downhill walking resulted in peak values of 700–1500 IU/liter 4–7 days later. It is concluded that it is the eccentric contractions that are responsible for the large enzyme efflux.
Noninvasive measurement of spinal cord conduction: Review of presently available methods
Authors: Eisen Andrew A. 
Published: January 2005

AbstractThe ability to measure spinal cord conduction velocity noninvasively is limited by available methodology. Surface recording of small spinal potentials, although feasible in infants and young children, is problematical in adults, especially when recording over the cervical spine. On the other hand, indirect methods designed to improve the signal‐to‐noise ratio, which include recording of somatosensory cortical evoked potentials, F‐waves, or other muscle responses, are limited by the unproven assumptions necessary in calculating spinal conduction. Additionally, each method has its own particular limitations. The majority of presently available noninvasive methods take a restricted, or no, account of conduction through the motor pathways. Despite these often serious limitations, each of the reviewed methods does play a useful clinical role in the electrophysiologic investigation of cord disease that is not visible radiologically. Knowledge of them allows for sufficient diversity to tackle most relevant problems until an ideal physiologic method is developed.
Effect of exercise on the motor unit
Authors: Edström Lars , Grimby Lennart 
Published: January 2005

AbstractThe motoneuron part of this review deals with the changes in recruitment and firing rates of the motor unit types upon changes from a physically inactive life to endurance or strength training. The muscle fibers react to prolonged exercise by adaptation to a higher level of performance. A matter of discussion is the prerequisites for a transformation between the basic muscle fiber types, slow twitch and fast twitch, during voluntary (transsynaptic) activity, which is demonstrated after artificial nerve stimulation. The review includes current knowledge of muscle fiber transformation as an adaptive response to increased usage either by electrical stimulation or by transsynaptic neuronal activity. The metabolic adaptation related to increased endurance is reviewed with special reference to effects on muscle fibers. The increase in strength as a result of high resistance training is mainly the result of increased muscle cross‐section. Whether this is solely the result of an increase in size of individual fibers or an increased fiber number is a controversial matter.
Effects of stretch and starvation on glucose uptake of rat soleus and extensor digitorum longus muscles
Authors: Shoji Shin'ichi 
Published: January 2005

AbstractTo examine the effects of stretch and starvation on muscle carbohydrate metabolism, glucose uptake was measured using [3H]3‐O‐methylglucose. Glucose uptake was higher in the stretched condition, and more so in soleus muscle than in extensor digitorum longus. After 4 days of starvation, glucose uptake decreased significantly in soleus muscle, but in extensor digitorum longus muscle, glucose uptake per noncollagen protein increased.
[3H]Nitrendipine receptors as markers of a class of putative voltage‐sensitive Ca2+ channels in normal human skeletal muscle and in muscle from duchenne muscular dystrophy patients
Authors: Desnuelle Claude , Renaud Jean‐François , Delpont Eric , Serratrice Georges , Lazdunski Renaud Delpont , Lazdunski Michel 
Published: January 2005

AbstractProperties of nitrendipine receptors have been analyzed in skeletal muscle from normal young boys and boys with Duchenne muscular dystrophy (DMD). The dissociation constant (Kd) of the complex formed by nitrendipine with its specific receptors was 0.5 ± 0.1 nM in dystrophic muscle and 0.4 ± 0.1 nM in normal muscle. Maximum binding capacities Bmax were 403 ± 80 and 460 ± 60 fmol/mg protein in DMD and normal muscle, respectively. These results suggest that nitrendipine binding sites on nitrendipine‐sensitive Ca2+ channel binding sites are not altered in Duchenne muscular dystrophy.
Selective synthesis and degradation of slow skeletal myosin heavy chains in developing muscle fibers
Authors: Dhoot Gurtej K. 
Published: January 2005

AbstractDuring fetal development of fast skeletal muscles in the rat, three types of cells could be identified using a monoclonal antibody to slow skeletal muscle myosin heavy chain. Presumptive type I cells stained positive for slow forms of skeletal myosin heavy chain and a previously described protein5 of an apparent molecular weight of 100 KD, whereas presumptive type 2B cells did not stain for either of these peptides. Presumptive type 2A cells, on the other hand, did not stain for slow isoform of 100‐K protein, but did stain positive for slow skeletal myosin heavy chain. There was a progressive suppression or degradation of slow skeletal myosin heavy chain in presumptive type 2A cells during subsequent fetal development, so that it was almost undetectable in most animals at birth. Soleus, a slow muscle, however, did not show clear differentiation into presumptive type I and type 2 cells until 4 days after birth.
Porcine malignant hyperthermia: Cell injury enhances halothane sensitivity of biopsies
Authors: Gallant Esther M. , Fletcher Thomas F. , Goettl Virginia M. , Rempel William E. 
Published: January 2005

AbstractA possible relationship between muscle cell injury or deterioration and enhanced halothane sensitivity was studied by monitoring mechanical responses of skeletal muscles from normal pigs and pigs susceptible to malignant hyperthermia (MH). Increased time postbiopsy and decreased maximum control tetanic tension both correlated significently with enhanced sensitivity to halothane. In both normal and MHsusceptible (MHS) muscles, greater halothane sensitivity was observed in cut cell than in intact cell bundles and in low tetanic tension as compared to high tension preparations. Subsequent to halothane exposure, twitches of high tension (≥ 1.75 kg · cm −2) intact bundles of both normal and MHS muscles were potentiated. Tetani of normal intact bundles were not altered, whereas those of MHS bundles were depressed after halothane exposure. Control twitch‐to‐tetanus ratios (twitch ratios) were higher in MHS (0.23) than in normal (0.12) intact bundles. According to discriminant analysis, the best distinction between normal and MHS muscles, either cut or intact, was obtained by comparing halothane‐induced changes in tetanic tension and control twitch ratios.
Targeting of lysosomal enzymes: N‐Acetylglucosamine‐1‐Phosphotransferase during muscle development
Authors: Den Halina , Shanske Sara , Dimauro Salvatore 
Published: January 2005

AbstractIt has been previously shown by morphological techniques and measurements of lysosomal enzyme levels that the I cell mutation is expressed in myoblasts but not in myotubes or mature muscle fibers. These findings suggested the possibility of developmental regulation of the affected enzyme, UDP‐N‐acetylglucosamine: lysosomal enzyme N‐acetylglucosamine‐phosphotransferase. In this article, we examine this possibility by measuring the phosphotransferase activity at various stages of muscle differentiation in three different animal species (human, chick, rat). Although activity of the enzyme is consistently higher in myoblasts than in myotubes or mature muscle, the difference in the levels of activity at these three states of muscle differentiation varies widely in the three species examined. We further found that the phosphotransferase activity was absent in the muscle of an I cell patient, in spite of normal muscle morphology. This indicates the presence of a mannose‐6‐phosphate‐independent mechanism for lysosomal enzyme targeting in muscle and other unaffected tissues. The existence of such a pathway cannot be explained by lack of the necessary enzyme, as the phosphotransferase is present at a comparable level in normal muscle of three different species (human, chick, rat).
Disturbances of neural conduction in isolated frog nerves following exposure to strong electric fields
Authors: Eickhorn Roland , Haverkampf Klaus , Antoni Hermann 
Published: January 2005

AbstractFrog sciatic nerves were isolated and the middle portion of each exposed to condenser discharges (field strength up to 1000 V/cm; time constants 0.2–8.0 ms) through the bathing fluid. The ability of the nerve to propagate action potentials (AP) was examined by stimulating the proximal end and recording the AP from the distal end of the exposed section. The fraction of the nerve fibers remaining propagative was estimated from the amplitude (or the area) of the compound AP. Strong discharges brought about a total block of propagation lasting for up to 30 minutes, followed by slow, but almost complete, restitution. The restitution was exponential against time and depended on the field strength and duration of the discharge. Discharges equal in energy but different in their voltage—condenser combinations had markedly different actions, with stronger effects being found at higher voltages and vice versa. Hence, the described effects are unlikely to be caused by dissipation of thermal energy only. Other mechanisms (ionic imbalance, dielectric breakdown, punch through) are discussed.
Developmental study of α‐glucosidases in japanese quails with acid maltase deficiency
Authors: Usuki Fusako , Ishiura Shoichi , Sugita Hideo 
Published: January 2005

AbstractIn Japanese quails with late‐onset acid maltase deficiency (AMD), the activity of acid α‐glucosidase was severely reduced to approximately 16% of the normal level from an embryonic age. The kinetic characteristics and inhibition by Zn indicated that the residual activity was responsible for the intrinsic activity of acid α‐glucosidase. However, in affected embryos, the glycogen content and other lysosomal enzyme activities were normal, despite the low acid α‐glucosidase activity. In a separate study, we found the existence of two age‐dependent neutral α‐glucosidases— “embryonic” and “adult” α‐glucosidases. In affected quails, the transition from the embryonic neutral α‐glucosidase to the adult type was not influenced by the disease. The activity toward maltose and glycogen of the embryonic neutral α‐glucosidase may explain the normal glycogen content in the affected embryos.
Clinical investigation in duchenne dystrophy. VI. Double‐blind controlled trial of nifedipine
Authors: Moxley Richard T. , Brooke Michael H. , Fenichel Gerald M. , Mendell Jerry R. , Griggs Robert C. , Miller J. Philip , Province Michael A. , Patterson Victor ,   CIDD Group
Published: January 2005

AbstractExcessive accumulation of intracellular calcium in Duchenne muscular dystrophy (DMD) may be a necessary step in the process that causes muscle damage in this disease. Because of this possibility, a controlled trial of the calcium channel blocking agent nifedipine was undertaken. One hundred and five patients were randomized and treated in a double‐blind manner for 18 months. Muscle strength, contractures, functional ability, cardiopulmonary changes, and laboratory data were monitored. The dose of nifedipine was 0.75‐1 mg/kg/day in the first 6 months and 1.5‐2 mg/kg/day for the next 12 months. Satisfactory blood levels of nifedipine were attained. The study had a power greter than 0.99 to detect a slowing of the illness to 25% of its original rate of progression. No significant improvement was demonstrated in the treated group. One or more of the frequent mild side effects of flushing, dizziness, and leg edema, often associated with the use of nifedipine in adults, occurred transiently in approximately one‐half of the patients in the nifedipine group and in 21% of the placebo group. Four patients died, two on nifedipine and two on placebo. This study demonstrates that nifedipine is safe to administer in children, but that it is without beneficial effect on the course of DMD.
Neuralgic amyotrophy: An increasingly diverse entity
Authors: England John D. , Sumner Austin J. 
Published: January 2005

AbstractWe describe nine cases of neuralgic amyotrophy whose clinical and electrophysiologic findings suggest lesions of individual peripheral nerves or peripheral nerve branches occurring singly (mononeuropathy) or in various combinations (mononeuropathy multiplex). There were four occurrences of isolated denervation of the pronator teres muscle; four occurrences of anterior interosseous nerve lesions; three occurrences of lateral antebrachial cutaneous nerve lesions; two occurrences of long thoracic nerve lesions; and one occurrence each of a median nerve trunk lesion, a median palmar cutaneous branch lesion, a suprascapular nerve lesion, and an axillary nerve lesion. “Neuralgic” pain was a prominent feature in all cases, and the location of the pain correlated with the location of the nerve lesions. We hypothesize that the specific course of certain nerves (especially their location across joints) selectively exposes them to mild focal trauma that increases their susceptibility to this disease. Whatever the etiology, this entity is considerably more diverse than generally appreciated.
Dantrolene sodium is able to reduce the resting ionic [Ca2+]i In muscle from humans with malignant hyperthermia
Authors: López José R. , Medina Pablo , Alamo Lorenzo 
Published: January 2005

AbstractMalignant hyperthermia (MH) is a hereditary myopathy, triggered when susceptible patients are exposed to a depolarizing muscle relaxant and/or potent volatile anesthetics. We have studied the effects of dantrolene on the free [Ca2+]i of intercostal muscle biopsies obtained from two MH‐susceptible patients before and after administration of dantrolene orally (2.5 mg/kg for 3 days) and intravenously (1.0 mg/kg 2 hours before the biopsy). The free [Ca2+]i was measured by Ca2+‐selective microelectrodes. The mean resting free [Ca2+]i in the MH‐susceptible muscle before dantrolene treatment was 0.42 ± 0.01 μM (mean ± SEM, n = 12). The administration of dantrolene reduced this value to 0.27 ± 0.01 μM (n = 14). There was no detectable difference in the resting membrane potential after dantrolene. These results represent the first direct demonstration that dantrolene is able to reduc the resting free [Ca2+]i in skeletal muscle of MH‐susceptible patients.
Demyelination in vivo by Guillain‐Barré Syndrome and other human serum
Authors: Brown Mark J. , Rosen Janet L. , Lisak Robert P. 
Published: January 2005

AbstractSerum from patients with acute inflammatory polyneuropathy (the Guillain‐Barré syndrome, GBS) demyelinates peripheral nerves in vivo more intensely than control human serum. To clarify the processes leading to demyelination we injected rat sciatic nerves with serum from GBS and control subjects in the presence of complement and examined the sequential morphologic changes over 7 days. One day after injection, five of six GBS sera but none of seven control sera caused vesicular demyelination; 3–5 days after injection both GBS and control sera produced macrophage‐mediated demyelination. These observations suggest that GBS serum can initiate acute myelin injury through a humoral mechanism that is disease associated. This response appears to be distinct from delayed cell‐mediated serum‐induced demyelination that is not disease specific.
The neurophysiologic investigation of small fiber neuropathies
Authors: Jamal Goran A. , Hansen Stig , Weir Andrew I. , Ballantyne John P. 
Published: January 2005

AbstractWe have applied our technique for the measurement of thermal thresholds to 25 patients referred with symptoms and signs of small fiber peripheral neuropathy in whom conventional electrophysiological indices were individually within the range of normal values for our laboratory. Vibration threshold determinations were also within normal range. Significant abnormalities of thermal thresholds were noted in all patients.The results indicate that the technique provides an accurate, easily performed and reproducible index of function in small Aδ and C groups of nerve fibers.
Prostaglandin E2 and the regulation of protein degradation in skeletal muscle
Authors: Barnett J. G. , Ellis S. 
Published: January 2005

AbstractWe tested the influence of PGE2 on protein degradation in isolated mouse and rat muscles. PGE2 had no influence on protein degradation rate in mouse muscles under several different incubation conditions and over a dose range of 28 nM to 28 μM. Furthermore, neither PGE2 (2.8 μM) nor arachidonic acid (5 μM) influenced protein degradation in rat muscles under incubation conditions identical to those previously reported. The biological activity of our PGE2 was confirmed with the rat stomach fundic strip preparation. We question the contention that PGE2 regulates protein degradation in skeletal muscle.