bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unimpaired energy metabolism in experimental neuropathy induced by p‐bromophenylacetylurea
Authors: Brimijoin Stephen , Mintz Keith P. 
Published: January 2005

AbstractThe contribution of defective energy metabolism to the induction of neuronal pathology by p‐bromophenylacetylurea (BPAU) was examined in several ways. It was found that a saturated aqueous solution of BPAU had no effect on the activity of crystalline glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) or phosphofructokinase (PFK). In rats with total hindlimb paralysis from treatment with BPAU (400 mg/kg), the endogenous GAPDH and PFK of sciatic nerve showed normal activity. Endogenous enolase and nerve‐specific enolase activities were likewise unaffected. Consequently, it appeared improbable that BPAU neuropathy involves impaired glycolysis. This conclusion was supported by the failure to prevent hindlimb weakness by feeding pyruvate, a substrate for the Krebs cycle. To test for interference with glycolysis at other steps, or for an impairment in oxidative phosphorylation, adenosine triphosphate (ATP) and creatine phosphate were measured. The amounts of high energy phosphates in nerves of paralyzed animals were found to be the same as in nerves of untreated and vehicle‐treated controls. A similar observation was made in nerves regenerating from a crush injury. To test turnover, ATP and creatine phosphate were measured in nerves exposed to an N2 atmosphere in vitro. Since the high energy phosphates disappeared at the same rates in all groups, it was concluded that BPAU neuropathy does not alter energy utilization. In our view, BPAU neuropathy arises by a mechanism that does not depend on altered energy metabolism.
Use of mononuclear precursor cells to insert allogeneic genes into growing mouse muscles
Authors: Watt Diana J. , Morgan Bsc Jennifer E. , Partridge Terence A. 
Published: January 2005

AbstractOur long‐term aim is to use allografts of normal muscle precursor cells to insert donor myonuclei, containing a normal genome, into the growing defective muscle fibers of young animals with inherited myopathies. In the present article, we have used isoenzyme variants of glucose‐6‐phosphate isomerase (GPI) as genetic markers of host and donor genomes in the mouse. We show that mononucleated cells, prepared by enzymatic disaggregation of neonatal donor muscle,39 can be used to introduce donor GPI genes into muscle fibers of growing muscles of young hosts. The expression of both donor and host GPI genes in the resulting mosaic muscle fibers leads to the formation of a “hybrid” GPI isoenzyme dimer. Such hybrid GPI was found in 10 of 102 host muscles examined. Our results indicate that grafts of muscles precursor cells can be used to alter the genetic constitution of both normal and mildly myopathic muscle.
Potassium depletion myopathy: A clinical and morphological study of six cases
Authors: Comi G. , Testa D. , Cornelio F. , Comola M. , Canal N. 
Published: January 2005

AbstractAcute myopathy in conditions associated with endogenous or druginduced potassium loss has been reported. We describe six patients with potassium depletion myopathy (P‐DM). The clinical picture included flaccid muscle weakness without sensory loss, myalgia, polyuria, and polydipsia. All the cases had markedly increased serum creatine kinase (CK) levels. The most consistent pathological characteristics were phagocytosis of degenerating muscle fibers plus fiber regeneration. Atrophy of type 2 fibers was observed. Vacuoles and vesicular elements originating from T‐tubules were also encountered. The clinical manifestations and morphological changes had reversed after potassium repletion. Both constriction of vascular smooth muscle and cellular energy failure may be pathogenetic factors in P‐DM.
Clinical investigation in Duchenne Dystrophy: V. Use of creatine kinase and pyruvate kinase in carrier detection
Authors: Griggs Robert C. , Mendell Jerry R. , Brooke Michael H. , Fenichel Gerald M. , Miller J. Phillip , Province Michael , Moxley Richard T. , Huntzinger Donna , Vaughn Arthur , Cohen Melinda , Conneally P. Michael , Bach Phillip ,   CIDD Group
Published: January 2005

AbstractWe have determined the value of creatine and pyruvate kinase (CK and PK) in carrier detection by evaluating 811 females in 73 families participating in the Collaborative Investigation of Duchenne Dystrophy. Thirty‐nine obligate carriers, 244 normal controls (paternal females), as well as 76 possible carriers and 351 carrier suspects had three CK and PK specimens analyzed at a central laboratory. The CK and PK values varied with age in normals: both fell with age early in life, and CK rose after the fifth decade. Discriminant analysis indicated that the combination of mean CK and PK corrected for age yielded the best data for calculation of carrier probability. Using the best model, only 45% of obligate carriers could be identified at a false‐positive rate of 2.5%. Daughters of obligate carriers have a disproportionate decline in CK and PK with age as compared to noncarrier females, suggesting that the rate of carrier detection will be higher in the first two decades. Our low rate of carrier detection, as compared to other studies, may reflect both the age of our obligate carrier population and the use of a control group that is more representative of the carrier population.
Basic polyaminoacids and protamine stimulate enzyme release from frog muscles
Authors: Suarez‐Kurtz Guilherme 
Published: January 2005

AbstractPolylysines, polyornithine, and protamine increased the release of creatine kinase (CK) and lactate dehydrogenase (LDH) from frog muscles. With 5 m̈g/ml (50 nM) of a polylysine of molecular weight 100,000, enzyme release reached peak values (ten‐fold above control) within 30 minutes; subsequent removal of the polylysine did not reduce significantly the release rates. The effectiveness of the polycations increased with the degree of polymerization. Their effects were prevented by pretreatment of the muscles with polyanions (heparin or polyglutamic acids) and were reversed when heparin was applied within 30 minutes of exposure to polylysine. The initial stimulation of enzyme release by polylysine was attenuated by Ca‐free solutions and by low temperature (4°C). It is suggested that, while fiber damage can explain the increased loss of sarcoplasmic enzymes after prolonged treatment of frog muscles with polycations, other mechanisms (perhaps exocytosis) are involved in the stimulation of CK and LDH release during brief exposures to nanomolar concentrations of polylysines or polyornithine.
The effects of inspiratory resistive training on respiratory muscle function in patients with muscular dystrophy
Authors: DiMarco Anthony F. , Kelling James S. , DiMarco Marianne Sajovic , Jacobs Irwin , Shields Robert , Altose Murray D. 
Published: January 2005

AbstractThe effects of inspiratory resistive training on respiratory muscle function was evaluated in 11 patients with Duchenne, limb‐girdle, and facioscapulo‐humeral (FSH) type muscular dystrophy. Muscle training consisted of breathing against an inspiratory resistance for two 15‐minute sessions each day while at home. Following 6 weeks of training, there were significant increases in the maximum resistance that could be tolerated for at least 5 minutes (P < 0.01) and also in the maximum duration that ventilations equal to 30%, 50%, 70%, and 90% of the maximum voluntary ventilation could be sustained (P < 0.05). In six patients who trained for an additional 6‐week period, respiratory muscle endurance increased even further. The degree of improvement in respiratory muscle endurance was positively correlated with baseline vital capacity (r = 0.84, P < 0.05) and maximal inspiratory pressure (r = 0.76, P < 0.05). Spirometry, functional residual capacity, and maximal inspiratory and expiratory pressures were not affected by training. We conclude that inspiratory resistive training improves respiratory muscle endurance in muscular dystrophy patients. Improvement in respiratory muscle function may serve to delay the onset of respiratory complications in patients with muscular dystrophy.
Intracellular ionized calcium concentration in muscles from humans with malignant hyperthermia
Authors: López José R. , Alamo Lorenzo , Caputo Carlo , Wikinski Jaime , Ledezma David 
Published: January 2005

AbstractCa2+ selective microlectrodes have been used to determine the free myoplasmic [Ca2+] in human skeletal muscle obtained from patients who had developed early signs associated with malignant hyperthermia (MH) during anesthesia. Intercostal muscle biopsies were performed under local anesthesia in four MH patients 15 days to 4 months after developing the MH crisis and in three control subjects. We used only microelectrodes that showed a Nernstian response between pCa3 and pCa7 (30.5 mV per decade at 37°C). Membrane resting potential (Vm) and calcium potential (VCa) were obtained from superficial fibers. The free cytosolic [Ca2+] was 0.39 ± 0.1 m̈M (mean ± SEM, n = 18) in muscle fibers obtained from malignant hyperthermic patients, whereas in control subjects it was 0.11 ± 0.02 m̈M (n = 10). These results suggest that this syndrome might be related to an abnormally high myoplasmic free resting calcium concentration, probably due to a defective function of the plasma membrane or the sarcoplasmic reticulum.
Computed tomography of the skeletal musculature in Becker‐type muscular dystrophy and benign infantile spinal muscular atrophy
Authors: De Visser Marianne , Verbeeten Bernard 
Published: January 2005

AbstractResults of computed tomographic (CT) examination of the skeletal musculature in 26 patients with Becker‐type muscular dystrophy (BMD) and 12 patients with benign infantile spinal muscular atrophy (BISMA) are presented. Both disorders reveled strikingly different changes that may have important clinical significance. First, in BMD, CT abnormalities consisted of areas of decreased densities, at first appearing in part of the muscle, and then gradually spreading until the whole muscle was replaced by low‐density tissue. In BISMA, however, low‐density lesions were scattered throughout the muscle. Second, in BMD, some muscles were preferentially affected in an early stage of the disease and others were relatively spared, whereas in BISMA, the muscles were involved more or less simultaneously. Third, an enlargement in size (hypertrophy) was frequently observed in BMD in various muscles of the legs, whereas in BISMA, this phenomenon can sometimes be noted only in the gastrocnemius muscles.
Electrophysiology of the facial nerve in hemifacial spasm: Ectopic/ephaptic excitation
Authors: Nielsen Viggo Kamp 
Published: January 2005

AbstractPathologic and pathophysiologic findings in hemifacial spasm are reviewed in connection with recent theoretical and experimental studies of ectopic/ephaptic excitation. The intracranial segment of the normal facial nerve is ensheathed by an arachnoid membrane only and shows no fascicular organization. In hemifacial spasm, this segment shows signs of demyelination. Several electrical phenomena relating to ectopic excitation, ephaptic transmission between facial nerve fibers, and autoexcitation can be reproduced in clinical electrophysiologic studies of hemifacial spasm. These abnormalities gradually disappear after facial nerve decompression in the cerebellopontine recess. It is concluded that (1) the normal facial nerve is vulnerable to minor compression, (2) the primary pathophysiologic mechanism in hemifacial spasm is ectopic/ephaptic excitation due to compression and demyelination of the intracranial segment of the facial nerve, and (3) the facial nerve in hemifacial spasm is a useful model for the study of ephaptic transmission, which has provided new information about the resolution of abnormal electrical events after decompression.
Diagnostic advantage of needle muscle biopsy and ultrasound imaging in the detection of focal pathology in a girl with limb girdle dystrophy
Authors: Heckmatt J. Z. , Dubowitz V. 
Published: January 2005

AbstractUltrasound imaging of the thigh in a 6‐year‐old girl with limb girdle muscular dystrophy showed striking focal involvment of the vastus intermedius and vastus lateralis muscles, with sparing and hypertrophy of the rectus femoris muscle. This was confirmed on needle muscle biopsy, using the Bergstrom needle, which showed normal histology in the rectus femoris and severe dystrophic change in the vastus intermedius. In neuromuscular disease, it is important to be aware of the possibility of focal muscle involvement, which can be screened for by ultrasound imaging and more effectively investigated by needle than by open muscle biopsy.
Endogenous lectins in normal and dystrophic muscle development
Authors: Ceri Howard , Roberts Delia 
Published: January 2005

AbstractTwo endogenous lectin activities, one specific for b̃‐D‐galactose (b̃‐D‐Gal) residues and purified on asialofetuin‐Sepharose and the second specific for iduronic acid containing glycosaminoglycans and purified on heparin‐Sepharose, have been studied during myogenesis in both normal and dystrophic chickens. The Storrs strain, homozygous for muscular dystrophy, and the dystrophic strain 413 from the University of California at Davis were both used in this study. Strain 412 and local hatchery chickens were used as controls. The lectins derived from all sources appeared to be identical based on physical properties and carbohydrate specificity. Both normal and dystrophic adult chickens possessed similar lectin levels in lung, spleen, kidney, heart, and muscle tissue. No differences were noted in the temporal appearance of the heparin‐binding lectin; however, the b̃‐D‐Gal‐binding lectin appeared earlier in the Storrs dystrophic strain than it did in the 413, 412, or hatchery embryos.
Reversible esophageal motor dysfunction in botulism
Authors: Nix Wilfred A. , Eckardt Volker F. , Krämer Günther 
Published: January 2005

AbstractTwo cases of botulism with autonomic and neuromuscular system involvment are presented. In both patients, dryness of the mouth and difficulties in swallowing were predominant symptoms. Esophageal manometry revealed a marked decrease in peristaltic amplitude, which was most pronounced in the upper third of the esophagus. These functional abnormalities returned to normal following recovery from the acute disease.
The temperature dependence of halothane‐induced contractures of skeletal muscle
Authors: Suarez‐Kurtz Guilherme , Sudo Roberto T. 
Published: January 2005

AbstractFrog muscles bathed in solutions equilibrated with 0.5%–2.0% halothane develop large contractures when cooled to 2–4°C. These halothane‐cooling contractures (HCC) are dose dependent and reproducible; they are potentiated by lidocaine (5 mM), abolished by procaine (5‐mM), and partially inhibited by procainamide (5 mM) or sodium salicylate (2 mM). The HCC provides a simple model system for investigating the effects of low halothane concentrations on Ca homeostasis and contractility in skeletal muscle.
The amino acid sequence of human cardiac troponin‐C
Authors: Roher Alex , Lieska Norman , Spitz Werner 
Published: January 2005

AbstractThe amino acid sequence of human cardiac troponin‐C (TN‐C) has been rabbit cardiac TN‐C. These results show that troponin‐C is one of the Edman degradation. The sequence, which consists of 161 amino acid residues is identical to that of the ox heart and as such is capable of binding three calcium ions. It differs at only one position from that of rabbit cardiac TN‐C. These results show that troponin C is one of the most highly conserved proteins known.
Electrophysiologic assessment of a median nerve injury in the palm
Authors: Busis Neil A. , Logigian Eric L. , Shahani Bhagwan T. 
Published: January 2005

AbstractIn median nerve lesions of the hand, electrophysiologic evaluation of the second lumbrical muscle can help to differentiate between lesions of the common digital nerves and the proper digital nerves, as illustrated by this case report. Median nerve conduction studies to the second lumbrical muscle can be performed by placing an active recording electrode just radial to the midpoint of the third metacarpal and stimulating the median nerve at the wrist or elbow.
The contribution of median—ulnar communications in diagnosis of mild carpal tunnel syndrome
Authors: Gutmann Ludwig , Gutierrez Alvaro , Riggs Jack E. 
Published: January 2005

AbstractIn six patients with characteristic symptoms of carpal tunnel syndrome, electrophysiologic studies were normal, except for an initial positive deflection of the thenar muscle action potential with median nerve stimulation at the elbow but not at the wrist. This phenomenon is only seen with coexistent carpal tunnel syndrome and median to ulnar nerve communication and suggests carpal tunnel syndrome is present in these patients. As normal electrophysiologic studies occur in carpal tunnel syndrome (up to 8%) and median to ulnar communications are common (15%–31%), this observed finding is of practical clinical importance in the diagnosis of mild carpal tunnel syndrome despite otherwise normal electrophysiologic studies.
Transient focal conduction block following experimental occlusion of the vasa nervorum
Authors: Parry Gareth J. , Linn Diana J. 
Published: January 2005

AbstractInjection of low‐dose arachidonic acid into the rat femoral artery occludes the vasa nervorum of the tibial nerve and produces focal and generalized ischemia with transient effects on nerve conduction. Across a severely ischemic segment of the proximal tibial nerve there is a marked fall in amplitude of the compound muscle action potential (CMAP), indicating focal conduction block. There is also significant slowing of maximal motor conduction velocity (MCV) through this nerve segment, but no dispersion of the proximally elicited response. Distally, in a region of less severe ischemia, there is mild slowing of MCV, but no further decrement in the CMAP amplitude. The conduction block begins 5–15 minutes after injection, reaches a nadir at 30 minutes, and persists in more severe cases for at least 2 hours. Despite these prolonged electrophysiologic abnormalities, there is no evidence of axonal degeneration or segmental demyelination.
Distribution of muscle changes in experimental ischemic myopathy
Authors: Maki Toshiyuki , Korthals Jan K. , Prockop Leon D. 
Published: January 2005

AbstractThe distribution of ischemic changes was examined in the medial gastrocnemius muscle of the cat, following transient simultaneous clamping of the aorta and femoral artery. Initial changes occurred in the middle portion of the muscle, in the areas corresponding to watershed zones of the primary arteries of the muscle. The superficial layers of the muscle, the regions close to the main stem of the primary arteries, and the entire distal portion of the muscle were the most resistant to ischemic damage. These studies demonstrate that in the feline medial gastrocnemius muscle, the vascular pattern is the primary factor in determining the distribution of ischemic changes. The role of differential muscle fiber vulnerability is only secondary.
IMP response: An indicator of metabolic stress in working muscle
Authors: Heller Scott L. , Choksi Rati , Brooke Michael H. 
Published: January 2005

AbstractAn in vitro system for the combined biochemical and physiologic analysis of striated muscle has been developed. It is hoped that its eventual application will be to the evaluation of human muscle disease. To test the method's usefulness in evaluating metabolic defects, we used iodoacetate to induce a glycolytic defect in animal muscle. This produced the expected effects of precipitous fatigue on repetitive stimulation, increased inosine monophosphate (IMP) and decreased adenosine triphosphate (ATP) and phosphocreatine; in addition, the severity of the glycolytic block was directly related to the amount of IMP produced per gram twitch tension.
Muscle morphology, enzymatic activity, and muscle strength in elderly men: A follow‐up study
Authors: Aniansson Amelie , Hedberg Marita , Henning Gull‐Britt , Grimby Gunnar 
Published: January 2005

AbstractA follow‐up study of muscle strength, muscle morphology, and enzymatic activity in 23 men, 73–83 years of age, was performed 7 years after the first investigation. With the exception of two men treated for congestive heart failure and four treated for hypertension, all were apparently clinically healthy and none had functional locomotor disturbances. Body weight was reduced by 2% and body cell mass by 6%, whereas the quadriceps muscle strength decreased 10%–22% over the 7‐year period. Fiber composition in the vastus lateralis did not change significantly, and there was no significant difference between the biopsies from the biceps brachii and vastus lateralis. In the vastus lateralis, there was a reduction in fast‐twitch fiber areas, which were smaller than in the biceps brachii (not studied at the previous investigation). There were also more histopathologic changes in the vastus lateralis than in the biceps brachii. The enzymatic activities of lactate dehydrogenase and myokinase, which were studied on both occasions in the vastus lateralis, did not change, and the activities of the other measured enzymes indicated a maintained metabolic capacity at high age. Oxidative enzymatic activities were higher in the vastus lateralis, and glycolytic enzymatic activities were higher in the biceps brachii, which could partly be explained by differences in relative fiber areas.
A double‐blind, placebo‐controlled, crossover study of verapamil in exertional muscle pain
Authors: Lane Russell J. M. , Turnbull Douglass M. , Welch John L. , Walton John 
Published: January 2005

AbstractEleven patients, comprising three cases of McArdle's disease and eight with an exertional muscle pain syndrome (EMPS) of unknown cause, entered a double‐blind crossover study of verapamil and placebo. None of the patients with McArdle's disease responded to verapamil, but two patients with unclassified EMPS experienced a striking improvement in symptoms and two others showed a partial response. No patient responded to placebo. Six of the eight cases with unclassified EMPS, including the four patients who responded to verapamil, had symptoms that indicated possible abnormalities of muscle metabolism, and four showed nonspecific biochemical, electromyographic, and muscle biopsy abnormalities. The two other EMPS patients had symptoms that suggested that a primary muscle disease was unlikely. They showed no laboratory evidence of muscle disorder, but had abnormal profiles on personality (MMPI) testing. Calcium antagonists, such as verapamil, may be useful in the treatment of some patients with benign exertional myalgia, but the mechanism of action of the drug in such cases is unclear.
Classification of peripheral neuropathy: The long and the short of it
Authors: Sabin Thomas D. 
Published: January 2005

AbstractInsights into how the nervous system functions have often sprung from knowledge of the localization of nervous system diseases. Indeed, the recent rebirth of behavioral neurology has been sparked by new insights into the topography of higher cortical functions. Yet, the localization of disease affecting the‐peripheral nervous system is simply assumed to be a by‐product of the beginning course in gross anatomy! Indeed, the anatomic sophistication laid out by Sunderland29 and reflected in the daily practice of electromyography might cause doubt as to the need for further inquiry into the problem of localization of disease within peripheral nervous system. There are, however, numerous problems in clinical practice that do not yield to the traditional root‐plexus‐nerve analysis of localization.