bluuebunny/crossref_metadata_2025_split huggingface dataset:
Red cell membrane protein phosphorylation in hemolytic anemias and muscular dystrophies
Authors: Tsung Pi‐Kwang , Palek Jiri 
Published: January 2005

AbstractWe review our current understanding of membrane phosphorylation in normal and abnormal erythrocytes. The major phosphoproteins in red blood cell (RBC) membranes are spectrin (band 2), bands 3, 2.1, and 4.5, and glycophorin A. At least two protein kinases can be distinguished on the basis of their stimulation by cyclic AMP and salt; they are present both in the membrane and in the cytosol. Analysis of the conflicting data on endogenous membrane‐protein phosphorylation in abnormal RBCs indicates a considerable variability of phosphorylation rates which largely depends on the manner of preparation of ghosts and enzyme assay conditions. This variability reflects differences in the partitioning of protein kinases between the membrane and cytosol, the specificity and accessibility of membrane‐protein substrates, and reaction kinetics. We select examples of data from several hemolytic anemias to illustrate that precautions are needed to interpret abnormalities of membrane‐protein phosphorylation properly; we discuss possible new methodological approaches.
Tubular aggregates in murine dystrophy heterozygotes
Authors: Craig I. D. , Allen Ingrid V. 
Published: January 2005

AbstractHeterozygous dystrophic mice (strain 129 ReJ dy/+) were studied to determine the morphological changes that are characteristic of the heterozygote state. The morphology of the muscle in 35 heterozygotes (+/?) was compared with that of 35 homozygotes (dy/dy) and 20 normal controls (+/+). Muscle was examined with light microscopy, standard histochemical techniques, and electron microscopy. Few abnormalities were detected with light microscopy or with histochemistry. With electron microscopy, some slight nonspecific evidence of muscle damage in the form of focal myofibrillar degeneration was seen in all of the heterozygotes. The striking abnormality, however, was the presence of tubular aggregates in type 2 fibers in 60% of the heterozygotes. Tubular aggregates were not found in homozygous dystrophic mice or in normal controls. The significance of this finding is discussed and it is suggested that tubular aggregates may represent lateral sac dilatation and infolding.
Isolated mechanical lesions of the sural nerve
Authors: Gross John A. , Hamilton William J. , Swift Thomas R. 
Published: January 2005

AbstractOne case of compression on neuropathy and one case of iatrogenic stretch injury to the sural nerve were demonstrated with electrophysiologic (EP) testing. Isolated mechanical injuries to the sural nerve may occur more frequently than is generally realized, and EP studies can greatly aid in the diagnosis of these injuries, thus avoiding the necessity for neuroradiologic investigations.
Measurement of local skeletal muscle blood flow in animals by the hydrogen electrode technique
Authors: Mishra Shri K. , Haining Joseph L. 
Published: January 2005

AbstractThe hydrogen (H2) electrode technique has been applied to the measurement of local skeletal muscle blood flow (LSMBF) in experimental animals (rats, rabbits, and monkeys). LSMBF was measured during resting and postexercise states, following epinephrine injections and during CO2 inhalation. Among the limited sites studied and/or measurements obtained, significant differences in LSMBF were found in only a few instances. During hypercapnia, LSMBF was found to be increased in some muscles in rats and monkeys. The present study demonstrates that the H2 electrode technique is a simple and reliable method for measuring resting and postexercise LSMBF in anesthetized animals. This method provides measurements at discrete loci, is easily reproducible, and causes little trauma.
Measurement of local skeletal muscle blood flow in normal humans by hydrogen clearance
Authors: Mishra Shri K. , Haining Joseph L. 
Published: January 2005

AbstractThe hydrogen (H2) electrode technique was adapted to the measurement of local skeletal muscle blood flow (LSMBF) in humans. Thirty‐five normal volunteers were utilized to study the biceps, deltoid, gastrocnemius, and quadriceps muscles at rest and following exercise. Results indicated statistically significant increases (P < 0.05) in postexercise compared with resting blood flows within the muscles. The highest mean value for LSMBF was found in deltoid muscle and the lowest in biceps. This study demonstrates the potential superiority of the H2 electrode technique over previous techniques for measuring absolute muscle blood flow at individual sites. It is suggested that measurements by means of the H2 electrode technique represent the most definitive values for skeletal muscle blood flow at this time, and its application could be especially important in various neuromuscular disorders in which some question remains concerning the role of abnormalities of the skeletal muscle vasculature.
Critical reexamination of the thymus immunization model of myasthenia gravis
Authors: Murphy Anne , Drachman Daniel B. , Satya‐Murti S. , Pestronk Alan , Eggleston Joseph C. 
Published: January 2005

AbstractPrevious studies have described an experimental model of myasthenia gravis (MG) produced by immunizing animals with thymus extracts. In view of the hypothesis that the autoimmune process in MG may be initiated within the thymus itself, we have reexamined this model using presently available methods to evaluate its resemblance to MG. We immunized Lewis rats with extracts of rat thymus in Freund's adjuvant, as originally described by G. Goldstein. Five procedures were used to test for myasthenic characteristics: (1) repetitive nerve stimulation; (2) recording of miniature endplate potentials; (3) assays of anti‐ACh receptor antibodies in serum; (4) determination of ACh receptors at neuromuscular junctions by [125|] α‐bungarotoxin binding; and (5) evaluation of the histology of the thymus gland. Our results showed that the thymus‐immunized animals did not demonstrate abnormalitities in any of these parameters. We conclude that immunization of rats with thymus extracts, as described, failed to produce a myasthenia‐like condition.
Carnitine levels in normal children and adults and in patients with diseased muscle
Authors: Carrier Henri N. , Berthillier Gisèle 
Published: January 2005

AbstractAn assay for evaluating carnitine levels in normal children and adults is described. After a 12‐hour period of fasting, individual variations in 24‐hour urinary excretion of carnitine were observed in adults. In children, there was a significant decrease in excretion from the 10th month to the third year, and then an increase until the 10th year. There was no significant difference between children and adults in the serum and skeletal muscle levels. Muscle carnitine levels were also studied in 12 cases of lipid‐storage myopathy and in cases of other muscle diseases, including Duchenne muscular dystrophy in children.
Tibial nerve H‐reflex and F‐wave studies in patients with uremic neuropathy
Authors: Panayiotopoulos C. P. , Lagos G. 
Published: January 2005

AbstractThe nerve conduction velocity along the whole length (knee to the spinal cord) of the 1a sensory and motor fibers of the tibial nerve, innervating the gastrocnemius and soleus muscles, of 29 control subjects and 32 patients with chronic renal failure was estimated with recently introduced electrophysiologic F‐wave and H‐reflex methods. In control subjects and in uremic patients, the proximal sensory (1a) nerve conduction velocity (SNCV) was faster than the proximal motor nerve conduction velocity (MNCV), a finding which is attributed to the larger diameter and therefore faster conduction properties of 1a fibers. In uremic patients, the proximal 1a SNCV and MNCV were significantly slowed in comparison with the values in control subjects, while the terminal M‐response latency was not significantly prolonged.
Plasmapheresis therapy in myasthenia gravis
Authors: Dau Peter C. 
Published: January 2005

AbstractPlasmapheresis in the treatment of myasthenia gravis has led to disparate results when applied by different investigators because of considerable differences in the volume, number, and tempo of plasmaphereses and in the type and amount of concomitant immunosuppressive drug therapy. Used as short‐term crisis intervention, plasmapheresis produces temporary clinical improvement and reduction in titer of antibody to acetylcholine receptor, even without accompanying drug therapy. When applied as long‐term primary therapy under optimal conditions, plasmapheresis is capable of generating stable improvement in most patients. This response appears to result from a synergistic action with immunosuppressive drugs, since it is characterized by a sustained reduction in titer of antibody to acetylcholine receptor. Where clinical circumstances warrant cytotoxic immunosuppression in patients with myasthenia gravis, consideration should be given to the simultaneous employment of plasmapheresis, in order to maximize benefit to the patient from a given exposure to drug therapy.
Polymyositis—an immunofluorescence study on the distribution of collagen types
Authors: Duance Victor C. , Black Carol M. , Dubowitz Victor , Hughes Graham R. V. , Bailey Allen J. 
Published: January 2005

AbstractType‐specific antibodies to the polymorphic types of collagen have been used to study their distribution in polymyositis. Dramatic increases were observed in the staining with antibodies to Type III collagen and, to a lesser extent, with antibodies to Types I, IV, and V. The changes in capillary and endomysial basement membrane collagens (Types IV and V) as well as the proliferation of perimysial Type III collagen are discussed in relation to the muscle atrophy observed during the disease.
A clinicopathologic study of acrodystrophic neuropathies
Authors: Said Gerard 
Published: January 2005

AbstractSixteen patients presenting with trophic changes associated with a peripheral neuropathy were investigated. Muscle power was normal in all patients, but neurogenic muscle atrophy was demonstrated in 4 of the 7 patients who had a muscle biopsy. Alcoholism was responsible for the neuropathy in 11 patients. In the other patients, one had primary hemochromatosis without diabetes and another a dominantly inherited primary hypertrophic neuropathy. Qualitative and quantitative light and electron microscopic studies, including teased nerve fiber preparations, showed axonal loss as the most salient feature. In the alcoholic patients, the large myelinated fibers were primarily involved, followed by small myelinated and unmyelinated fibers. The lesions were predominant distally as shown in patients who had a sural nerve biopsy at both calf and ankle levels. A mechanism of dying‐back degeneration of the longest sensory fibers is the most plausible explanation for neurological and pathological abnormalities. In alcoholic neuropathy with trophic changes, loss of sensory fibers is more important than in alcoholic neuropathy without trophic changes. In familial and sporadic cases, axonal loss is more severe and unmyelinated fibers are more severely affected than in alcoholic acrodystrophic neuropathy. Patients with peripheral neuropathies who present with loss of pain sensation but have preserved muscle power are especially exposed to the development of trophic changes induced by usual trauma in insensitive tissues.
Early ultrastructural changes in aging rat gastrocnemius muscle: A stereologic study
Authors: de Coster W. , de Reuck J. , Sieben G. , Eecken H. Vander 
Published: January 2005

AbstractNormal gastrocnemius muscle of Wistar rats at various ages to 2 1/2 years was studied. No light microscopic or qualitative electron microscopic changes were seen. However, stereologic determinations revealed significant reductions in volume and surface densities of sarcoplasmic reticulum, t‐tubular system, and glycogen content. These alterations were considered to be the morphologic expression of the very early age‐related changes in gastrocnemius muscle.
Respiratory function in the muscular dystrophies
Authors: Rideau Y. , Jankowski L. W. , Grellet J. 
Published: January 2005

AbstractThe purpose of this investigation was to compare the respiratory function of patients with different clinical types of muscular dystrophy (MD). A total of 190 patients representing facioscapulohumeral MD (n = 20), limb‐girdle MD (n = 50), Becker MD (n = 20), Duchenne MD (n = 90), and the “intermediate” type of MD (n = 10) were studied using simple spirometric respiratory function tests. The respiratory modifications observed in the 3 adult forms indicate that pulmonary function was almost normal. Respiratory function in Duchenne muscular dystrophy (DMD) was always characterized by a restrictive syndrome which severely impaired pulmonary function. The vital capacity (VC) underwent ascending, plateau, and descending phases during the course of the disease. The VC at the plateau stage may be used as an estimate of life span. The most interesting finding was the high degree of variability in the restrictive syndrome associated with DMD. In the DMD group 30% presented a severe restrictive respiratory syndrome associated with a life span of less than 20 years (Type 1), 40% had a serious restrictive syndrome and variable mortality (Type 2), and the remaining 30% had a moderate restrictive respiratory syndrome (Type 3).
Experimental rapid sarcomere loss with concomitant hypoextensibility
Authors: Tabary Jean‐Claude , Tardieu Catherine , Tardieu G. , Tabary C. 
Published: January 2005

AbstractSlow soleus muscle in guinea pigs was actively shortened by constant electrical stimulation of the sciatic nerve for 12 hours. At the end of this period, hypoextensibility and a 25% decrease in the numbers of sarcomeres were observed. When a 36‐ or 48‐hour period was allowed to elapse after the end of stimulation, some recovery occurred, and the sarcomere numbers were then found to be diminished by only 5%. If the stimulation was performed when the muscle was prevented from shortening (by ankle fixation in dorsiflexion), there was no decrease in sarcomere numbers and no hypoextensibility. In relation to humans, these findings may be of pathophysiological and therapeutic importance in cases of muscle hypoextensibility after neuroaxis lesions, when abnormal contractions maintain lasting shortening of the muscle.
Abnormal RNA metabolism in spinal motor neurons in the wobbler mouse
Authors: Murakami T. , Mastaglia F. L. , Mann D. M. A. , Bradley W. G. 
Published: January 2005

AbstractRNA metabolism was studied in anterior horn neurons in wobbler mice. In the wobbler mice, RNA content was reduced in histologically normal neurons but not consistently reduced in vaculated neurons, as compared with normal littermates. Nuclear and nucleolar incorporation of [5–3H]uridine was reduced both in vacuolated and in histologically normal neurons of wobbler mice, while cytoplasmic counts were higher in histologically normal neurons of wobbler mice than in vacuolated neurons or the neurons of normal littermates. These findings point to an abnormality of RNA synthesis which precedes the earliest morphological changes seen in nerve cells with the light microscope. Nuclear [5–3H]uridine uptake was reduced both in small and in large neurons, a finding suggesting that the metabolic abnormality is probably not confined to α‐motoneurons.
Serum creatine kinase in the detection of duchenne muscular dystrophy carriers: Effects of season and multiple testing
Authors: Percy Maire E. , Andrews David F. , Thompson Margaret W. 
Published: January 2005

AbstractThe usefulness of serum creatine kinase (CK) activity in the detection of Duchenne muscular dystrophy (DMD) carriers is dependent upon a reliable control distribution. In controls there is a small but reproducible seasonal variation in CK activity, with a statistically significant variation in the upper 95th percentile (78 IU/liter in May, 53 IU/liter in November, as compared with 67 IU/liter for the whole calendar year). Because CK values in DMD heterozygotes are higher in November than in May, the carrier detection rate may be highest in November. Failure to consider this seasonal variation in controls may cause misclassification of too many normal subjects. If tests are conducted throughout the year, however, the seasonal influence can be reduced by serial testing at intervals of several months. In this case, use of the highest of the results obtained in 3 tests compared with the normal range of single measurements misclassifies too many normal subjects. Use of the mean of 3 determinations provides more accurate classification.
Energetics of isometric contraction in dystrophic fast and slow muscles
Authors: Nwoye L. O. , Goldspink G. 
Published: January 2005

AbstractThe amount of phosphoryl creatine (PC) hydrolysed during a ten‐second isometric contraction was measured in the biceps brachii (fast) and soleus (slow) muscles of adult normal and dystrophic mice (Re 129 strain) following inhibition of glycolysis and oxidative phosphorylation. The dystrophic muscles were found to have a lower isometric economy (tension‐time integral per μmol PC) than the normal muscles. This was particularly so in the case of the fast biceps brachii muscle which is affected by dystrophy to a greater extent than the slow soleus muscle. The isometric economy of the dystrophic muscles was lower even when the results were based on a total creatine rather than on a weight basis. This suggests there may be some defect in the contractile proteins of dystrophic muscle. The normal soleus muscle was found to be approximately three times more economical in maintaining tension than the normal biceps brachii muscle. This indicates the adaptation of slow muscles such as the soleus are used for maintenance of posture.
Branched‐chain ketoacids reduce muscle protein degradation in duchenne muscular dystrophy
Authors: Stewart Peter M. , Walser Mackenzie , Drachman Daniel B. 
Published: January 2005

AbstractIn order to determine whether branched‐chain ketoacids can reduce the excessive rate of muscle protein degradation that characterizes Duchenne muscular dystrophy, nine boys affected with the disease were studied in a metabolic ward while receiving meat‐free diets. After a three‐day equilibration period, excretion rates of 3‐methylhistidine and creatinine were measured in two consecutive four‐day periods. In the second period, a supplement containing a mixture of ornithine α‐ketoisocaproate, α‐ketoisovalerate, and α‐keto‐β‐methylvalerate in a proportion of 4 : 1 : 1 was administered orally at a dosage of 0.45 gm/kg/day. During treatment with the ketoacids, 3‐methylhistidine excretion fell by a small (mean: 14%) but highly significant (P < 0.01) extent, whether expressed in absolute terms or in relation to creatinine excretion. No adverse effects were noted. We conclude that this mixture of ketoacids acutely reduces muscle protein degradation in patients with Duchenne muscular dystrophy.
Signs of reinnervation in myasthenia gravis
Authors: Hilton‐Brown Per , Stålberg Erik V. , Osterman Per Olof 
Published: January 2005

AbstractIn a study of 71 patients with myasthenia gravis, the local fiber density of muscle fibers within motor units was estimated with single fiber electromyography (SFEMG). The fiber density was increased significantly in the patient group, compared to normal controls. This increase was not correlated to disease severity or duration, but was significantly higher in patients treated with cholinesterase inhibitors as compared to untreated patients. The study indicates a slight reorganization of the motor unit in untreated patients with myasthenia gravis and more pronounced changes in patients treated with cholinesterase inhibitors.
Myosin light chain components in single muscle fibers of duchenne muscular dystrophy
Authors: Takagi Akio , Ishiura Shoichi , Nonaka Ikuya , Sugita Hideo 
Published: January 2005

AbstractSingle muscle fibers were prepared from biopsy specimens of Duchenne muscular dystrophy (DMD), normal, and neuromuscular disease controls. Single muscle cells were classified as type 1, type 2, or intermediate by the skinned fiber method. The intermediate fiber was most abundant in DMD, comprising 29% of fibers examined. The fiber type of single muscle fibers was contrasted to the composition of myosin light chain (MLC) components, which was analyzed by micro two‐dimensional gel electrophoresis. In DMD, each of the components exhibited the same electrophoretic mobility as those in the controls. Type 1 fibers of DMD were more diverse in the composition of MLC than those of controls; 55% of type 1 fibers of DMD contained distinct fast‐type MLC 3. Some intermediate fibers contained all five MLC components, but in others the composition was not different from usual type 1 or type 2 fibers. The diversity of MLC composition in DMD muscle cells might reflect the abundance of young muscle fibers in the tissue due to active muscle regeneration andsol;or retardation of maturation.
Abnormal distribution of proteins in the soleus and extensor digitorum longus of dystrophic mice
Authors: Jasch Laura G. , Bressler Bernard H. , Ovalle William K. , Slonecker Charles E. 
Published: January 2005

AbstractProteins of the whole muscle homogenates of the slow‐twitch soleus (SOL) and fast‐twitch extensor digitorum longus (EDL) of normal and dystrophic C57BL/6J mice at 4, 8, 12, and 32 weeks of age were resolved on polyacrylamide isoelectric focusing gels. Gels of the normal SOL proteins at all ages contained two bands specific to SOL and not represented in EDL. Gels of normal EDL contained three bands highly amplified in EDL but barely detectable in SOL. The distribution of proteins in dystrophic SOL was abnormal at all age groups studied due, in part, to a decrease in the proportion of SOL‐specific proteins relative to other proteins in the muscle. The distribution of proteins in dystrophic EDL appeared abnormal first at 12 weeks due to a decrease in the relative proportion of EDL‐amplified proteins. Due to these and other changes, at 32 weeks the dystrophic SOL and EDL were almost indistinguishable on the basis of their proteins' distributions.
Congenital nemaline myopathy. I. Defective organization of α‐actinin is restricted to muscle
Authors: Jennekens Frans G. I. , Roord John J. , Veldman Henk , Willemse Jacobus , Jockusch Brigitte M. 
Published: January 2005

AbstractThis investigation was undertaken to find out whether the structural and biochemical changes seen in skeletal muscles in congenital nemaline myopathy (CNM) occurred also in nonmuscle cells. It was confirmed that nemaline bodies contain α‐actinin. The distribution of actin and α‐actinin in the examined nonmuscle cells was considered normal. The motility of the leucocytes and the fibroblasts was indistinguishable from that of those in normal controls. Slight changes in the peripheral nerve fibers of one patient were found, but these were not seen in another patient. The results indicate that congenital nemaline myopathy is not a generalized disorder but is restricted to skeletal muscle.
Autosomal recessive generalized myotonia
Authors: Sun Sallie F. , Streib Erich W. 
Published: January 2005

AbstractTwo siblings and a first degree cousin of a consanguinous marriage were afflicted with recessive generalized myotonia (RGMy). All had muscle weakness which was particularly prominent after rest, thinning of the forearms, weakness of anterior compartment muscles, and muscular contractures. The first degree cousin was the most severely afflicted with congenital myotonia. Muscle biopsy and electromyography were consistent with a myopathy. Exercise after rest demonstrated a marked reduction in muscle membrane excitability in all patients.