Active state properties of denervated and immobilized muscle: comparison with dystrophic muscle.

Possible roles of neurotrophic mechanisms and muscle activity in the contractile abnormalities of muscular dystrophy were studied by comparing human dystrophic muscle to denervated and immobilized muscle. As evident in denervated muscle from the decreased acceleration of twitch development (decreased active state intensity of shortening), and isoproterenol-induced decrease of twitch with shortened decay of the active state, part of the abnormality in the subcellular calcium transport system in dystrophic muscle seems to be influenced by disordered neural regulation. Other active state abnormalities relating to activation processes and contractile proteins in dystrophic muscle were also demonstrated in both denervated and immobilized muscle, with some being more marked in immobilized muscle. The findings indicate that a neurogenic hypothesis cannot entirely explain the pathogenesis of progressive muscular dystrophy.

Muscular dystrophy in six young girls.

Clinical and genetic studies were made on progressive muscular dystrophy in six young girls. No chromosome abnormality was observed in these patients. The pedigree of one case implied a sex-linked recessive trait, and clinical features were identical with Duchenne dystrophy. The clinical manifestations of two sisters in another family were less severe than in their brother with Duchenne dystrophy. The clinical differences among these three cases are well explained by the Lyon hypothesis. Three other cases were compatible with childhood muscular dystrophy of autosomal recessive inheritance.

Ultrastructural localization of acetylcholine receptor at the motor endplate: myasthenia gravis and other neuromuscular diseases.

Peroxidase-conjugated alpha-bungarotoxin (P-BGT) was used for the ultrastructural localization of the acetylcholine receptor in motor endplates. Brachial biceps muscle specimens were obtained from six patients with myasthenia gravis (MG) (two ocular and four generalized), five other patients with neuromuscular diseases (limb-girdle dystrophy, polymyositis, and amyotrophic lateral sclerosis) and two controls. In all patients with generalized MG, most of the endplates showed a marked decrease in P-BGT binding. In one of two patients with ocular MG, the amount and distribution of P-BGT binding appeared normal, whereas the other patient showed a slight decrease in P-BGT binding. There was a loose correlation between clinical severity of MG and acetylcholine receptor index or antiacetylcholine receptor antibodies. On the other hand, the amount and distribution of acetylcholine receptor in other neuromuscular diseases was well preserved, even at the endplates denuded of their nerve terminals in amyotrophic lateral sclerosis (ALS) cases.

Limb muscle endplates in ocular myasthenia gravis: quantitative ultrastructural study.

Motor endplate ultrastructure in the biceps brachii was quantitatively analyzed in five patients with ocular myasthenia gravis (56 endplates), six patients with generalized myasthenia gravis (83 endplates), and five controls (64 endplates). Ultrastructural changes of the motor endplates were observed in nonweak limb muscles of patients with ocular myasthenia gravis as well as in generalized myasthenia; these changes were mostly restricted to the postsynaptic region. Decrease of the mean presynaptic and postsynaptic membrane length, and postsynaptic membrane density, were more remarkable in generalized myasthenia than in ocular myasthenia. Widening of the primary and secondary synaptic clefts was also observed more frequently in generalized myasthenia. There was no correlation between ultrastructural alterations and the duration of symptoms or treatment, severity of disease, or titers of antiacetylcholine receptor antibody.

Effects of long-term administration of ambenonium chloride on motor end-plate fine structure and acetylcholine receptor in rat.

Ambenonium chloride was administered orally in a dosage of 6 mg/kg/day to rats for 14-360 days. Motor end-plate fine structure and junctional AChR were quantitatively analyzed and red (soleus) and white (EDL) muscle fibers. In treated animals, degeneration and simplification of postsynaptic folds and widening of synaptic clefts were often observed in soleus end-plates, but infrequently in EDL end-plates. On the other hand, the postsynaptic AChR was reduced markedly in both soleus and EDL end-plates. No presynaptic changes were observed. These results show that long-term administration of Anti-ChE agents in myasthenia gravis may have an adverse effect on neuromuscular transmission.

[The Tolosa-Hunt syndrome: report of a case with recurrent (9 times) painful ophthalmoplegia (author's transl)].

A 48-year-old woman was referred to the First Dept. of Int. Med., Nagasaki Univ. Sch. Med., in August, 1979, with a six-month history of recurrent episodes of right-sided painful ophthalmoplegia and diplopia. An epidode affected the right eye, lasted one to two weeks, and relapsed every month. On examination she had a complete ptosis on the right side and pain on the right eye. All extraocular muscle supplied by the 3rd nerve were paralysed. The pupils were equal in size both sides, reacting to light completely. Visual acuity was normal except myopia. All the other cranial nerves and the remainder of central nervous system was normal. Results of thyroid function tests and of lumbar puncture were normal. The glucose tolerance test showed a mild diabetic pattern. Blood and CSF cultures for bacteria, fungi, and acid-fast bacillus were negative. The skull, brain CT scan, and carotid angiogram were within normal limits. A tentative diagnosis of Tolosa-Hunt syndrome was made after an unproductive search for a cause for this woman's painful ophthalmoplegia and unsuccessful treatment of ophthalmoplegia with antibiotics or diet therapy for mild hyperglycemia. The patient was given prednisolone 30 mg daily orally when she had the 9th attack of painful ophthalmoplegia Pain, ptosis, and diplopia disappeared in 5 days and she did not show any recurrence of symptoms over the next 7 months.

[A family of von Recklinghausen's neurofibromatosis complicated by mononeuritis multiplex, bilateral acoustic neurinomas, and falx and spinal meningiomas].

A family of von Recklinghausen's disease complicated by multiple diverse primary brain tumors was reported. Case 1. The proband, born in 1923, was admitted to the Nagasaki University Hospital on March 11, 1974, for evaluation of headache and hearing loss. Neurological examination disclosed: decreased visual acuity on the right: bilateral choked discs; anisocoria, right pupil wider than left; right blepharoptosis; artificially fixed right eye; right facial palsy; markedly impaired hearing with negative vestibular responses to caloric test; paralysis of the right soft palate and vocal cord; atrophy of the right side of the tongue; right claw hand with positive Froment's sign; left drop foot; loss of deep reflexes on the left arm and legs; positive Babinski on the right. Nerve conduction studies revealed failure to evoke muscle action potential in response to electric nerve stimulation on the left ulnar and right superficial peroneal nerves. Needle electromyography showed no motor unit potentials in the left first dorsal interosseus and right anterior tibial muscles. Sensory nerve action potentials could not be evoked on any nerves tested. X-ray films showed enlargement of the internal auditory passages, falx tumor on brain scan and carotid angiography, and spinal tumor on myelography. At craniotomy, a 7 X 5.5 X 4 cm falx meningioma was removed. At suboccipital craniotomy performed five weeks later, right acoustic neurinoma measuring 1.5 cm in diameter was removed. Case 2. This relative, born in 1945, was the son of the proband. A spinal meningioma at C 7-T 1 was removed in 1957. However, he could not walk after operation and died of pneumonia two years later.(ABSTRACT TRUNCATED AT 250 WORDS)

PP094. A comparison of gestational changes in urinary excretion of magnesium with those of calcium.

INTRODUCTION: Magnesium is one of the essential minerals required in various cellular functions. Some investigators have postulated that some aspects of pathophysiology in preeclampsia could be associated with alteration in regulatory mechanisms of the mineral. However, gestational changes in absorption, excretion and blood concentration of magnesium have remained less elucidated compared with those of calcium, which is another important mineral forming a divalent cation. OBJECTIVES: The purpose of this study was to clarify if urinary excretion of magnesium during pregnancy might be altered compared with those of calcium. METHODS: Sixty specimens of 24h urine and 586 samples of spot urine were collected from healthy pregnant women who gave consent. Determination of the minerals were according to Orthocresol-phthalein complexone method for calcium, and xylidyl blue method for magnesium. Urinary creatinine was determined by Jaffe Method. RESULTS: Daily excretions of magnesium determined with 24h samples were 60, 70, 81, 65, and 102mg in 1st, 2nd, and early 3rd trimesters, term, and postpartum 4weeks, respectively. There were no statistical differences among the values. Those of calcium were 174, 186, 139, 52, and 40mg, respectively. The values in term and in postpartum were significantly lower than those in 1st through early 3rd trimesters. The Mg/Cr ratios (mg/mg Cr) determined with spot urine samples were 0.064, 0.071, 0.066, 0.067, and 0.086, in 1st, 2nd, and early 3rd trimesters, term, and postpartum 4weeks, respectively. The value of Mg/Cr in postpartum was significantly higher than the values in pregnant period. The Ca/Cr ratios (mg/mg Cr) were 0.164, 0.163, 0.135, 0.118, and 0.090, respectively. There was a trend of decreasing pattern in changes of Ca/Cr from 2nd trimester to postpartum. CONCLUSION: It is suggested that there is a mechanism of preservation of calcium in the late phase of pregnancy or puerperal period by reducing urinary excretion of the mineral. However, human pregnancy does not seem to show such a function controlling magnesium metabolism.