bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lipid storage myopathy, ichthyosis, and steatorrhea
Authors: Miranda A. , DiMauro S. , Eastwood A. , Hays A. , Johnson W. G. , Olarte M. , Whitlock R. , Mayeux R. , Rowland L. P. 
Published: January 2005

AbstractA 41‐year‐old man had ichthyosis, ectropion, steatorrhea, and slowly progressive proximal limb weakness. Biopsies showed abnormal lipid accumulation in muscle, liver, skin, leukocytes, and gastric mucosa. Lipid storage was particularly marked in cultures of skin and muscle, and it increased in subsequent cell generations. By electron microscopy, the lipid globules showed no limiting membranes. The stored lipid was identified by thin‐layer chromatography as triglyceride; there was no excess of cholesterol or cholesteryl esters. Muscle carnitine concentration and activities of carnitine palmityltransferase and acid lipase were normal; 14CO2 production from labeled palmitate in leukocytes was not impaired. The excessive accumulation of triglyceride in different tissues and in the progeny of cells in tissue culture suggests a genetic error of lipid metabolism.
Spontaneous electrical muscle fiber activity in polymyositis and dermatomyositis
Authors: Streib Erich W. , Wilbourn Asa J. , Mitsumoto Hiroshi 
Published: January 2005

AbstractForty patients with polymyositis or dermatomyositis underwent detailed electromyographic evaluation. The paraspinal muscles of all patients were examined, as were several extremity muscles. The distribution of fibrillation potentials (FPs) in different muscles is discussed. FPs were most frequent in paraspinal muscles. We conclude that, for any patient suspected of having a myopathy, electromyographic examination should include the paraspinal muscles.
Subclinical entrapment of the lateral femoral cutaneous nerve: An autopsy study
Authors: Jefferson D. , Eames Rosemary A. 
Published: January 2005

AbstractFive out of 12 lateral femoral cutaneous nerves, removed at routine autopsies, showed pathologic changes in myelinated nerve fibers in the vicinity of the inguinal ligament. These changes included both local demyelination and Wallerian degeneration, particularly affecting the fibers with the largest diameters. The presence of polarized internodal swellings on single nerve fibers from two specimens suggested that mechanical factors were involved in pathogenesis. Endoneurial vascular thickening confined to the region of the inguinal ligament was also seen and may be implicated in the production of some of the symptoms of meralgia paresthetica (MP).
Effects of D‐penicillamine on neuromuscular transmission in rats
Authors: Aldrich Michael S. , Kim Yong I. , Sanders Donald B. 
Published: January 2005

AbstractTreatment of patients with D‐penicillamine (D‐P) has been associated with a syndrome similar to myasthenia gravis (MG). To explore this association, we examined the effects of D‐P on neuromuscular transmission in rat muscle. In the first experiment, bath‐applied D‐P had no significant effect on either miniature endplate potential (MEPP) amplitude or action potential (AP) amplitude. Endplate potential (EPP) amplitude and spontaneous MEPP frequency decreased significantly at concentrations approximately 40 times the maximum human therapeutic level. In the second experiment, rats receiving D‐P by daily injections for 33 to 37 days did not differ from controls in any of the measured electrophysiologic characteristics. Electron microscopy of muscle endplates from rats treated with D‐P showed no evidence of degeneration or simplification. In all cases, thymus histology by light microscopy was normal, and no antireceptor antibodies were found. Thus, D‐P has a mild direct presynaptic effect on neuromuscular transmission at high concentrations, but this effect is too small to account for the weakness seen in the myasthenia‐like syndrome in humans.
Polyaxonal myelination in developing dystrophic and normal mouse nerves
Authors: Brown Mark J. , Radich Sandra J. 
Published: January 2005

AbstractMyelin‐forming Schwann cells in the peripheral nervous system characteristically surround and myelinate only single axons. Polyaxonal myelination is an anomaly of this one‐to‐one relationship whereby one normal‐appearing Schwann cell myelinates multiple axons. We examined the ventral roots and the proximal sciatic and posterior tibial nerves of developing normal mice and of dy2J/dy2J dystrophic mice with proximal failure of myelination. Polyaxonal myelination was a rare feature in normal nerves. Examples of polyaxonal myelination were observed six times more often in dystrophic than in normal mice and were most abundant in proximal sciatic nerves. Polyaxonal myelination could result from either an axonal or a Schwann‐cell abnormality, or it may be the nonspecific response of uncommitted Schwann cells to an early failure of myelination.
Congenital muscular dystrophy: Case reports and reappraisal
Authors: Lazaro Reynaldo P. , Fenichel Gerald M. , Kilroy Anthony W. 
Published: January 2005

AbstractWe report four cases of congenital muscular dystrophy; all demonstrated hypotonia and multiple contractures at birth. Strength remained stationary or improved, but the tendency for contracture formation persisted. Brief small amplitude polyphasic potentials were recorded on electromyography, and muscle biopsy revealed extensive fat and/or collagen replacement, which was out of proportion to fiber necrosis or patient strength. The consistent clinical and pathologic features of these patients and others described in the literature justify considering this disorder to be a specific nosologic entity.
Fatty acid biosynthesis in wallerian degeneration of rat sciatic nerve
Authors: Koeppen Arnulf H. , Papandrea John D. , Mitzen Edward J. 
Published: January 2005

AbstractIn‐vitro fatty acid biosynthesis was studied in normal rat sciatic nerve and during wallerian degeneration. Normal nerve incorporated 1,3‐C14‐malonyl‐CoA and 1‐C14‐acetyl‐CoA into fatty acids by a de‐novo biosynthetic pathway. The reaction product with highest radioactivity was palmitic acid, and the free fatty acids of nerve contained 90% of the total fatty acid label. During wallerian degeneration, there was a rapid increase of fatty acid biosynthesis that reached a peak between 16 and 24 days after nerve section. Values declined to normal levels at approximately 50 days.
Biochemistry of muscle membranes in Duchenne muscular dystrophy
Authors: Rowland Lewis P. 
Published: January 2005

AbstractIn Duchenne muscular dystrophy, as in other genetic diseases, there must be a biochemical abnormality. This fundamental genetic fault has not been identified, but several indirect lines of evidence suggest that the surface membranes of skeletal muscle are affected. The biochemical evidence implies abnormal egress of soluble enzymes and other proteins from muscle, abnormal permeability, and altered properties of membrane‐bound enzymes. As a result of the presumed genetic abnormality, functional properties are altered, and impaired regulation of intracellular calcium content could be responsible for the hallmarks of the disease—progressive weakness and degeneration of muscle. The evidence is by no means conclusive, however, and some of it is contradictory. Technical advances must be made before isolated membranes can be characterized biochemically. Other theories are also being evaluated.
Application of the freeze fracture technique to the study of human neuromuscular disease
Authors: Schotland Donald L. , Bonilla Eduardo , Yoshihiro Wakayama  
Published: January 2005

AbstractThis is a review of the application of the freeze fracture technique to the study of human neuromuscular disease. The advantages and limitations of the method are discussed, and the application of the technique is illustrated by a study of skeletal muscle plasma membrane in Duchenne muscular dystrophy.
Facilitatory effects of 4‐aminopyridine on normal neuromuscular transmission
Authors: Kim Yong I. , Goldner Marcia M. , Sanders Donald B. 
Published: January 2005

AbstractThe effects of 4‐aminopyridine (4‐AP) on neuromuscular transmission were studied in vitro in the rat flexor digitorum longus muscles. 4‐AP produced dose‐dependent increases in endplate potential (EPP) amplitude, in rise time to peak, and in the average number of acetylcholine quanta released by presynaptic nerve impulses. The neuromuscular blocking effects of d‐tubocurarine or low Ca2+/high Mg2+ concentrations could be completely reversed by 4‐AP, and EPPs developed into muscle action potentials (APs). The drug had minimal effects on the amplitude or frequency of spontaneous miniature endplate potentials, but increased the duration of indirectly elicited muscle APs. The action of 4‐AP required the presence of extracellular Ca2+; thus, its effect may be to promote Ca2+ entry into the motor nerve terminal, and thereby increase the neurally evoked transmitter release. 4‐AP is effective in overcoming both presynaptic and postsynaptic blockade of neuromuscular transmission, suggesting a potential role for this drug in the treatment of neuromuscular diseases.
“Snapping bottom”: Subluxation of the tendon of the long head of the biceps femoris muscle
Authors: Rask Michael R. 
Published: January 2005

AbstractSubluxation of the tendon of origin of the long head of the biceps femoris muscle (or snapping bottom) is a rare, previously unreported degeneration of the tendinous attachment of the muscle at the ischial tuberosity. It occurs in a patient who wears out this attachment through a lifetime of hyperflexion hip movements, such as are required in bending to reach the floor. The snapping of the tendon across its point of origin causes pain and swelling in the buttock. In the older nonathlete, if conservative measures fail, the treatment of choice is simple tenotomy. The condition should not be confused with weaver's bottom (ischiogluteal bursitis), even though it may be a cause for that bursitis.
Superior gluteal nerve entrapment syndrome
Authors: Rask Michael R. 
Published: January 2005

AbstractEntrapment of the superior gluteal nerve can occur as a result of compression by anterior‐superior tendinous fibers of the piriformis muscle and cause aching claudication‐type buttock pain, weakness of abduction of the affected hip with a waddling gait, and tenderness to palpation in the area of the buttock superolateral to the greater sciatic notch. Instilling anesthetic into the point of entrapment may relieve the pain completely, but superior gluteal neurolysis may be required to effect a permanent cure.
Measurement of acetylcholine receptor and anti‐receptor antibodies by ELISA
Authors: Norcross N. L. , Griffith I. J. , Lettieri J. A. 
Published: January 2005

AbstractBoth acetylcholine receptor (AChR) and antibodies capable of binding to the AChR can be measured using the recently developed enzymelinked immunosorbent assay (ELISA). The assay is very sensitive and reproducible. Because of the relative simplicity of the ELISA in comparison to radioimmunoassay procedures currently used to measure anti‐AChR antibodies, the ELISA may prove valuable as a clinical diagnostic tool for the human disease myasthenia gravis.
Changes in sarcomere length following tenotomy in the rat
Authors: Baker James H. , Hall‐Craggs E. C. B. 
Published: January 2005

AbstractThe medical belly of the gastrocnemius and the extensor digitorum longus muscles of rats were tenotomized. One day following tenotomy, the mean sarcomere length of the fast medial gastrocnemius was 1.8 μm, a value comparable to that of tenotomized slow soleus. The mean sarcomere length of the tenotomized extensor digitorum longus, however, was 2.0 μm, a figure which differed significantly from the values obtained for both the soleus and the gastrocnemius. Histological preparations showed the presence of central core degeneration in slow fatigue‐resistant fibers of the tenotomized gastrocnemius comparable to that seen in the soleus. No changes were found in the fibers of the tenotomized extensor digitorum longus. The fact that central core lesions were produced in the fibers of soleus and medial gastrocnemius but not in the extensor digitorum longus may be related to the lesser reduction in sarcomere length following tenotomy of the latter muscle.
Muscle phosphofructokinase deficiency: Two cases with unusual polysaccharide accumulation and immunologically active enzyme protein
Authors: Agamanolis Dimitris P. , Askari Ali D. , Di Mauro Salvatore , Hays Arthur , Kumar Kusum , Lipton Mark , Raynor Andrew 
Published: January 2005

AbstractTwo patients with phosphofructokinase (PFK) deficiency had exercise intolerance and increased serum activity of creatine kinase; one presented with hemolytic anemia, hyperuricemia, and gouty arthritis. The glycogen concentration in the muscle of these patients was about twice normal. PFK activity was virtually absent in muscle, but antibodies against the M subunits of the normal human PFK showed cross‐reacting material in muscle from both patients. The PFK level in red blood cells, studied in one case, was lower than normal in the patient and both parents. Morphologically, there was extensive deposition of normal glycogen underneath the sarcolemma and in the intermyofibrillar space. In addition, 2% to 3% of the myofibers contained hyaline, PAS‐positive, diastase‐resistant inclusions that had a filamentous fine structure; histochemical reactions suggested an insoluble form of glycogen. Similar inclusions have not been described previously in PFK deficiency. Accumulation of an abnormal polysaccharide in muscle may be due to a second undiscovered enzymatic defect or may be a metabolic consequence of PFK deficiency.
Dominantly inherited peroneal muscular atrophy (hereditary motor and sensory neuropathy type I) in infancy and childhood
Authors: Vanasse M. , Dubowitz V. 
Published: January 2005

AbstractA detailed clinical and electrodiagnostic study has been undertaken of demyelinating polyneuropathy in 14 children (9 male, 5 female) from 11 sibships and their parents. The onset of symptoms was before the age of 2 years in 12 of the 14 children, and the condition in all cases was nonprogressive or very slowly progressive. In each case one of the parents had a slow motor nerve conduction velocity. Five of the 11 affected parents were completely asymptomatic. Electrodiagnostic studies in both parents of all children with demyelinating peripheral neuropathy are thus important to identify the dominantly inherited form of the disease.
Congenital cervical spinal atrophy
Authors: Darwish Husam , Sarnat Harvey , Archer Carol , Brownell Keith , Kotagal Suresh 
Published: January 2005

AbstractThree children presented at birth with axial hypotonia and symmetrical flaccid paresis limited to the upper extremities, and involving proximal and distal muscle groups. At birth, palmar flexion creases were poorly developed, and the hand muscles were atrophic. These clinical features, the muscle biopsy findings, and the nonprogressive course, suggest a vascular insult to the cervical spinal cord during gestation. The term, congenital cervical spinal atrophy seems most descriptive of these features.
Inherited canine giant axonal neuropathy
Authors: Duncan Ian D. , Griffiths Ian R. , Carmichael Stewart , Henderson Susan 
Published: January 2005

AbstractTo date, a single case of canine giant axonal neuropathy (GAN) has been recorded. The present report describes the disease in 3 more dogs from the second litter produced by the parents of the original case. Regular clinical and electrophysiological examinations were carried out on all 11 dogs of the second litter. At 14–16 months of age, 3 dogs developed slight posterior ataxia which progressed to a severe lower motor neuron disturbance involving only the hind legs. During this period, each dog began to regurgitate food as a result of megaesophagus. From 12 months of age, there was a progressive reduction in the amplitude of the evoked muscle action potential. Biopsy of the tibial fascicular nerve at 16 months of age confirmed that all 3 dogs had GAN, with numerous swollen unmyelinated fibers and less frequent enlarged myelinated fibers containing accumulated neurofilaments.
Hemiplegic atrophy: Electrophysiological and morphological studies
Authors: Segura Roberto P. , Sahgal Vinod 
Published: January 2005

AbstractA patient with hemiplegic atrophy following stroke is described. Electrophysiological studies confirmed the absence of root or peripheral nerve involvement. Findings of severe muscle membrane dysfunction and the morphological evidence of lower motor neuron pathology point to a central nervous system process as the origin of the observed changes.
Cross‐reactivity of anti‐acetylcholine receptor autoantibodies
Authors: Garlepp Michael J. H. , Kay Peter H. , Dawkins Roger L. , Bucknall Roger C. , Kemp Andrew 
Published: January 2005

AbstractThe heterogeneity of the specificities of anti‐acetylcholine receptor (anti‐AChR) antibodies of myasthenia gravis (MG) patients has been demonstrated by comparing reactions against a panel of xenogeneic AChR. For each patient there was a more or less unique cross‐reactivity profile. Such heterogeneity emphasizes the need to use human AChR for the routine detection of anti‐AChR. In vitro cross‐reactivity was important in predicting the effect of anti‐AChR after passive transfer to rats. Specificity may influence the outcome in human neonates receiving maternal anti‐AChR via the placenta. In contrast to the extreme heterogeneity seen in spontaneous MG, the antibodies associated with D‐penicillamine–induced MG were more homogeneous.
Clinical study of paramyotonia congenita with and without myotonia in a warm environment
Authors: Haass Anton , Ricker Kenneth , Rüdel Reinhardt , Lehmann‐Horn Frank , Böhlen Reinhard , Dengler Reinhard , Mertens Hans Georg 
Published: January 2005

AbstractFourteen patients with paramyotonia congenita were examined clinically. Patients of 3 farnilies had no myotonia in a warm environment while in a cold environment they developed paradoxical myotonia (myotonia aggravated by repeated muscle contraction). Patients of a 4th family had myotonia associated with after‐activity in a warm environment which was not paradoxical. This myotonia was aggravated by cooling. In a warm environment the resting muscles of all patients showed no spontaneous electromyographic activity except for occasional myotonic runs. On cooling, spontaneous fibrillations developed. This was most intense at 32°C–28°C (muscle temperature). On deeper cooling it ceased. In contrast, 5 patients with myotonia congenita did not show such activity during cooling. In all paramyotonic patients cooling (30°C–25°C) produced muscle paralysis, which outlasted rewarming by several hours. At 32°C–30°C muscle relaxation was slowed. Recording of electromyographic activity and isometric contractions of the long finger flexors during cooling revealed that the slowing of muscle relaxation in paramyotonia is not as closely linked to after–activity as is the slowing of muscle relaxation in myotonia congenita.
Membrane defects in paramyotonia congenita with and without myotonia in a warm environment
Authors: Lehmann‐Horn Frank , Rüdel Reinhardt , Dengler Reinhard , Lorković Hrvoje , Haass Anton , Ricker Kenneth 
Published: January 2005

AbstractThree patients with paramyotonia congenita and 3 control persons were biopsied for an in vitro investigation of the sarcolemmal membrane parameters and of contractile properties of paramyotonic muscle. At 37°C, paramyotonic muscle fibers had normal resting potentials, but on cooling to 27°C they depolarized. Depolarization to –60 mV caused spontaneous activity, and further depolarization to –40 mV caused inexcitability. Depolarization could be prevented by the application of tetrodotoxin, a finding suggesting a defect in the Na channels. Analysis of the membrane current densities using voltage clamps with 3 microelectrodes revealed that in paramyotonic patients at 37°C all component conductances were normal, except for a decreased CI conductance in the patient who had myotonia in a warm environment. At 27°C, the Na and CI conductances were abnormally high. The K conductance was always normal. The results explain the clinical symptoms of weakness and paralysis. Potassium‐ and caffeine‐contracture experiments gave normal results. The clinical symptom of paramyotonic stiffness, therefore, has not been explained by these studies.
Acetylcholine receptor antibodies in myasthenia gravis
Authors: Kornfeld Peter , Nall James , Smith Harry , Mittag Thomas W. , Bender Adam N. , Ambinder Edward P. , Horowitz Steven H. , Papatestas Angelos E. , Gross Harvey , Genkins Gabriel 
Published: January 2005

AbstractA multivariate statistical analysis of levels of serum acetylcholine receptor antibody (AChR Ab) obtained from 197 patients with various clinical forms of myasthenia gravis (MG) was performed. Elevated AChR Ab levels are specific for MG, but normal AChR Ab levels do not rule out MG. Patients in remission or with purely ocular MG had the lowest incidence of elevation of serum AChR Ab levels, while patients with generalized, severe MG, particularly in the presence of thymoma, tended to have the greatest antibody elevations. Corticosteroids depressed AChR Ab levels, but thymectomy did not exert a consistent effect on antibody levels within a 24‐ to 30‐month postoperative period. The relatively low 55% positivity of antibody elevations in all 197 patients probably reflects the use of heterologous (rat) AChR.
Effect of corticosteroids on the thymus in myasthenia gravis
Authors: Craven Catherine , Reddy P. Krishna , Ringel Steven P. , Rutherford Robert B. 
Published: January 2005

AbstractThe weight and histological appearance of the thymus from patients with myasthenia gravis were studied. Nine patients treated with corticosteroids were compared with 10 patients not treated with corticosteroids before thymectomy. The thymuses of corticosteroid‐treated patients were found to have significantly increased fat and connective tissue, decreased germinal centers, and poorer corticomedullary differentiation than those of untreated patients. The glandular weight and degree of myoepithelial stroma were the same in both groups. The changes following corticosteroid treatment mimic those following aging or acute stress, with retention of the myoepithelial stroma but depletion of thymic lymphoid elements. In myasthenic patients not undergoing thymectomy, the possibility remains that persistent myoepithelial tissue can adversely affect the prognosis.
Surface recording of the H‐reflex of the flexor carpi radialis
Authors: Jabre Joe F. 
Published: January 2005

AbstractAlthough the H‐reflex of the triceps surae is used routinely in nerve conduction studies of the lower extremities, doubt still exists concerning the H‐reflex in the upper extremities. The H‐reflex of the flexor carpi radialis is easily obtainable and can be recorded by a simple nerve conduction technique detailed in this communication.
Dynamic aspects of structural proteins in vertebrate skeletal muscle
Authors: Obinata T. , Maruyama K. , Sugita H. , Kohama K. , Ebashi S. 
Published: January 2005

AbstractIn this review, our current knowledge on the structural proteins of vertebrate skeletal muscle is briefly outlined. Structural proteins include the contractile proteins (actin and myosin), the major regulatory proteins (troponin and tropomyosin), the minor regulatory proteins (M‐protein, C‐protein, F‐protein, l‐protein, and actinins), and the scaffold proteins (connectin, desmin, and Z‐protein). In addition, the relative turnover rates of the muscle proteins (M‐protein < troponin > soluble protein as a whole > tropomyosin = α‐actinin > myosin > 10S‐actinin > actin) are discussed. The changes in the turnover of muscle proteins are compared in denervated and dystrophic muscles. The properties of the various proteases in muscle, including alkaline protease, calcium‐activated neutral protease (CANP), and acidic protease (cathepsins), and the structural alterations of myofibrils by these proteases are also described. Finally, the role of proteases and their inhibitors in diseased muscle is summarized, with focus on CANP and its inhibitors, leupeptin and E‐64.