ISSN:0148-639X    

DOI:10.1002/mus.880040102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractThe neutral lipid content of skeletal muscle fibers was determined by computing the lipid accumulation index (LAI) on transverse cryostat sections stained with Oil Red O. The LAI was defined as: (total area of neutral lipid droplets in a fiber) × 100/(total cross‐sectional area of a fiber). The biceps, diaphragm, and soleus muscles were studied in 3 groups of guinea pigs: normal animals, animals fasted for 48 hours, and animals subjected to muscle denervation and then fasted for 48 hours. and animals, subjected to muscle denervation and then fasted for 48 hours. In normal animals, the highest mean LAI was found in the diaphragm (4.93) in comparison with lower values in the biceps (2.25) and soleus (2.09). After fasting, these values were markedly increased; there was also a concomitant increase in plasma free fatty acid (FFA) concentration. Prior denervation further increased the LAI in biceps and soleus but reduced it in the diaphragm. Type 2A fibers tended to show high lipid accumulation when the plasma FFA concentration was high. Type 2B fibers never accumulated much lipid under any circumstances. Type 1 fibers varied in their response in the different muscl

ISSN:0148-639X    

DOI:10.1002/mus.880040103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractSingle skinned fibers were prepared from muscle biopsies of patients with Duchenne muscular dystrophy (DMD) and other neuromuscular diseases. The activation of the contractile system by calcium or strontium ion and the function of the sarcoplasmic reticulum were studied. In many fibers of the biopsy specimens from patients with DMD, activation by strontium revealed a pattern intermediate between those shown by the usual type 1 and type 2 fibers. These fibers were generally of smaller diameter and produced less maximal tension than type 1 and 2 fibers. The study of muscle of newborn animals suggests that this unusual pattern of activation might reflect either arrested development or incomplete regeneration after muscle necrosis in the disease.

ISSN:0148-639X    

DOI:10.1002/mus.880040104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractSera of patients with myasthenia gravis (MG) contain anti‐acetylcholine receptor (AChR) lgG antibodies (Ab) which have different antigenic specificities. Three Ab types were detected: (1) MG‐I, which forms immune complexes with AChR; (2) MG‐C, which decreases binding of AChR to concanavalin A; and MG‐B, which blocks α‐bungarotoxin binding to AChR. Sera from 152 MG patients were screened for the Ab types. Sixty‐one percent contained MG‐I, 26% contained MG‐C, 10% contained MG‐B, and 5% contained both MG‐C and MG‐B. The latter Ab types were associated with more severe forms of MG but showed no other clinical correlations. IgG antibodies of defined type were purified, and their interaction with unlabeled and toxin‐prelabeled AChR from denervated rat muscle was studied in detail. Receptors are homogeneous with respect to determinants recognized by MG‐I, but heterogeneous with respect to determinants recognized by MG‐C (3 subpopulations, 22%, 28%, and 50% of AChR) and by MG‐B (2 subpopulations, 30% and 70% of AChR). The stoichiometry of AChR interaction with the antibodies indicates that for each toxin‐binding site, the receptor is divalent as an antigen for MG‐I and MG‐C but is tetravalent for MG‐B. Denervated muscle AChR appears to be a mixture of at least 3 molecular forms of AChR, each of which has distinct immunological features as well as components com

ISSN:0148-639X    

DOI:10.1002/mus.880040105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

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.

ISSN:0148-639X    

DOI:10.1002/mus.880040106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractIn recent years, the following ideas have been expressed: (a) that all cases of a discrete, inherited neuromuscular syndrome should prove to be due to a single biochemical defect, (b) that any single biochemical defect should give rise only to one syndrome, and (c) that an enzymatic defect cannot give rise to a disease unless there is virtual absence of activity, that is, less than 5% or 10% of the normal value. We review evidence from research in neuromuscular, neurological, and other genetic diseases of humans that suggests the contrary. There are now examples of single clinical syndromes related to each of several defects, of defects of one biochemical reaction related to two or more distinct clinical syndromes, and of partial defects associated with disease in a way that suggests a causal relationship.

ISSN:0148-639X    

DOI:10.1002/mus.880040107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractRed blood cell and plasma cholinesterases were evaluated in control subjects and patients with the major forms of adult, sporadic motor neuron disease. For the purposes of this communication, the patients were considered as having amyotrophic lateral sclerosis (ALS) or its subtypes. Cholinesterase and acetylcholinesterase activities were evaluated and separated by dose response to their respective inhibitors. No kinetic differences were observed comparing red blood cell or plasma enzyme activities using either inhibitor. As found in previous studies, acetylcholinesterase accounted for more than 90% of acetylcholine hydrolysis in red blood cells. The plasma data were more complicated to evaluate, but at least 20% of total activity could be attributed to acetylcholinesterase. When red blood cell acetylcholinesterase activities of patients and controls were compared, no statistically significant difference was found. However, when plasma acetylchlinesterase activity was compared between the 2 groups, a statistically significant increase, almost twice the control value, was found in the ALS patients. These data may ultimately be important in the prognosis of this disease and, conceivably, could aid in understanding its pathogenesis.

ISSN:0148-639X    

DOI:10.1002/mus.880040108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractThe acute effect of intraperitoneal injection of phenytoin on rat peripheral nerve was studied. Conduction velocities in the ventral caudal nerve were measured hourly and phenytoin blood levels were obtained 4 to 5 hours after injection. Conduction velocity decreased by 23% in the 25 phenytoin‐treated animals from a control value of 30.0 ± 1.3 m/sec (mean ± SEM) to a 4‐hour value of 23.0 ± 1.3 m/sec (P<0.001). The phenytoin blood level 4 hours after injection was 45.0 ± 1.3 μg/ml. Amplitudes of evoked muscle action potentials in the treated group decreased by 37% from control values. High levels of phenytoin induce prompt slowing of nerve conduction velocity within hours, which may be mediated by mechanisms similar to those responsible for toxic central

ISSN:0148-639X    

DOI:10.1002/mus.880040109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractNerve conduction studies have been performed in 19 subjects with hereditary spinocerebellar degenerations other than Friedreich ataxia. Clinically, they may be classified as olivopontocerebellar atrophy or cerebello‐olivary degeneration. In 9 patients, sensory conduction was abnormal, and in the whole group there was a significant impariment of sensory conduction and mild slowing of motor conduction in the lateral popliteal nerve. Sural nerve biopsies were performed on 5 patients. In 3 cases there was a mild to moderate reduction of myelinated fibers of all diameters; unmyelinated fibers were normal. In 1 patient from a kindred with a spinocerebellar degeneration in which the inheritance was autosomal dominant, neuropathological findings at autopsy confirmed the clinical diagnosis of the Menzel type of olivopontocerebellar atrophy; thee was degeneration of dorsal root ganglion and anterior horn cells as well as of myelinated fibers of all diameters in the sural nerv

ISSN:0148-639X    

DOI:10.1002/mus.880040110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY

摘要:

AbstractThe excretion of endogenous creatinine and 3‐methylhistidine by subjects with muscle diseases has been measured in order to assess muscle mass and fractional rates of myofibrillar protein degradation. Increases in the rates of myofibrillar protein breakdown were observed in all subjects with Duchenne, Becker, autosomal recessive Duchenne‐like, and limb‐girdle muscular dystrophy; dystrophia myotonica; myotonia congenita; peroneal muscular atrophy; myasthenia gravis; and central core disease; in some cases of spinal muscular atrophy; but in no cases of facioscapulohumeral muscular dystrophy or dystonia musculorum deformans. All increases in myofibrillar protein breakdown were associated with reductions in muscle proportion below the normal. Muscle‐wasting diseases may respond to therapy directed towards an inhibition of muscle protease activity; the efficacy of such therapy can be monitored by the 3‐methylhistidine–to–creatinine ex

ISSN:0148-639X    

DOI:10.1002/mus.880040111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1981

数据来源: WILEY