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Biomedical subjects

I Nonaka

Publications and source records attributed to I Nonaka.

At least 433 records · Page 24Linked to original sources

Fetal muscle characteristics in nemaline myopathy.

In addition to the intracytoplasmic rods in approximately 1/4 muscle fibers, there were a large number of fibers with fetal muscle characteristics in a female infant who had severe muscle weakness and hypotonia, and failure to thrive since birth. A histochemical examination disclosed abnormal distribution in muscle fiber types including remarkable type 1 fiber predominance and increased number of type 2 C fibers (11.4%). Scattered throughout were fibers consisting of multiple myocytes enclosed in a single basement membrane, and small-calibered fibers containing abundant intermediate (skeleton) filaments and dispersed microtubules. Both were histologically identical to premature fibers found in the fetal muscle. The existence of an increased number of satellite cells as compared with age-matched controls was also suggestive of delayed or arrested muscle fiber maturation. A certain impaired neural influence upon the developing muscle is probably responsible for producing abnormal fiber type distribution and immature small-calibered fibers which account for small muscle bulk and muscle weakness in nemaline myopathy.

Asphyxia Neonatorum↗

Congenital myopathy without specific features (minimal change myopathy).

Three patients including a father and his daughter as well as a sporadic case who had a history of delayed developmental milestones showed symptoms of generalized muscle weakness predominantly in the neck flexors, high-arched palate, slender stature, myopathic face and nasal tone vocalisation. Histological and histochemical examinations on the biopsied muscles demonstrated minimal nonspecific changes; mild variation in fiber size, slight abnormality in fiber type distribution and an increased number of undifferentiated type 2C fibers. The abnormal muscle pathology was assumed to have resulted from delayed muscle fiber growth and differentiation due to a probable defective neural influence upon the developing muscles.

Adult↗

Immunocytochemical localization of cathepsin B in degenerating rat skeletal muscle induced by a local anesthetic, bupivacaine.

Experimental acute degenerative changes in skeletal muscle accompanied by a drastic increase in cathepsins B&L were induced in rats by intramuscular injection of a local anesthetic, bupivacaine. Cathepsins B&L have been implicated in the rapid disappearance of muscle fibers. Degenerating muscle showed a spotty fluorescence when stained with antibodies against cathepsin B, indicating that the increased cathepsin B did not originate from the muscle itself, but from invading phagocytes. We report here results showing that cathepsin B of nonmuscle cell origin is involved in the breakdown of myofibrillar proteins in acute bupivacaine-induced muscle degeneration.

Animals↗

Effect of cycloheximide administration on bupivacaine-induced acute muscle degradation.

We have examined the effect of cycloheximide on bupivacaine-induced, macrophage-mediated muscle degeneration in rats and obtained the following results. Direct intramuscular injection of bupivacaine into soleus muscle caused uniform muscle degeneration (Ishiura, S. et al. (1983) J. Biochem. 94, 311-314). The degeneration was most prominent 48 h after injection, with many infiltrating macrophages. Intraperitoneal administration of cycloheximide prevented the bupivacaine-induced macrophage invasion and decrease of structural proteins 48 h after injection. Cycloheximide inhibited the increase in lysosomal enzymes in bupivacaine-treated muscle. The peritoneal macrophages increased in number immediately after bupivacaine injection, while cycloheximide inhibited their accumulation. These results indicated that cycloheximide inhibited muscle degradation by preventing macrophage proliferation.

Animals↗

Muscle histochemistry in congenital muscular dystrophy with central nervous system involvement.

Muscles from 13 patients with clinical characteristics of congenital muscular dystrophy and central nervous system involvement (Fukuyama type) (FCMD) were examined using morphometric and fiber type analysis. The muscles from patients aged 5 months to 3 years demonstrated small-calibered fibers with increased variation in fiber size, connective tissue proliferation, and scattered necrotic and regenerating fibers. Groups of atrophic fibers were absent. Both type 1 and type 2 fibers were affected, though type 1 fibers predominated and type 2B fibers decreased as the disease progressed. The muscle changes were apparently progressive, affecting not only the limbs but also the intercostal, diaphragm, and cardiac muscles. Although there was no qualitative difference in the muscle histochemistry between FCMD and Duchenne muscular dystrophy (DMD), there was a greater proportion of type 2C fibers and fibrosis was present at the early infantile stage of FCMD.

Adenosine Triphosphatases↗

Therapeutic trial with protease inhibitor (leupeptin) in chicken muscular dystrophy. A histologic and histochemical study.

For the purpose of observing the therapeutic benefit of protease inhibitors for progressive muscular dystrophy, a large quantity of doses of leupeptin of 10 mg/kg/day and 50 mg/kg/day were administered i.p. to male chickens afflicted with hereditary muscular dystrophy (line 413) for 4 months starting on the 7th day ex ovo. No clinical improvement was identified in physical ability as a result of the examination by flip test, and creatine kinase (CK) values. The number of necrotic fibers in the pectoralis superficialis (PS) muscle which is known to be preferentially damaged in dystrophic chicken, did not decrease significantly in the birds treated with 10 mg leupeptin/kg/day (number of necrotic fibers; 47.7/mm2) and 50 mg/kg/day (46.4/mm2) as compared to that of the untreated ones (43.2/mm2). A morphometric analysis of fiber diameter distribution also showed no statistical difference between the treated and untreated birds. In the second group, 10 mg leupeptin/kg and a combination of leupeptin and bestatin of 10 mg/kg each were injected directly into the left lower half of the PS muscle three times a week for 4 months. Necrotic fibers were still present in the injected site, remote area of the left upper PS muscle treated with leupeptin (52.7/mm2), leupeptin and bestatin (52.2/mm2), and contralateral right upper PS muscle (41.6 and 53.5/mm2, respectively). The number of necrotic fibers in treated muscles was again not significantly different from that in untreated dystrophic ones (39.6/mm2). In fiber diameter analysis, no statistical difference was recognized between the treated and untreated dystrophic muscles.

Aminopeptidases↗

Basilar artery occlusion in a case of Duchenne muscular dystrophy.

This is a report of a case of Duchenne muscular dystrophy (DMD), with multiple infarcts in the territories of the basilar artery. He developed abrupt vomiting and transient left hemiparesis at the age of 4 years. The episodes were seen 3 times between 4-year-1-month to 5-year-1-month old. Transaxial computerized tomography (CT) revealed multiple, well-defined but irregularly marginated areas of low density centered in the mid- and upper pons, right cerebral peduncle and thalamus. A right vertebral angiogram illustrated the narrowed basilar artery. The rectus femoris muscle was biopsied at the age of 4-year-1-month which showed marked variation in fiber size, myonecrosis with phagocytosis, central nuclei, and adipose and connective tissue proliferation, which were consistent with those seen in DMD. It remains unknown whether the basilar artery occlusion was an incidental event in this particular case or closely related to the disease process of DMD.

Biopsy↗

Vacuolar myopathy with type 2 A fiber atrophy and type 2 B fiber deficiency. A case of childhood form acid alpha-1,4-glucosidase deficiency.

This report describes a female patient with childhood form of acid maltase deficiency who survived till fifteen years old. Although acid alpha-1,4-glucosidase was deficient in the liver, kidney, skeletal and cardiac muscles, neutral alpha-1,4-glucosidase was present in normal concentrations in those organs. On light microscopic examination, numerous intracytoplasmic vacuoles containing acid phosphatase positive granules and PAS positive materials were present in both type 1 and 2 A fibers, predominantly in the latter. The striking finding in the present case was a selective type 2 fiber atrophy with type 2 B fiber deficiency believed to result from type 2 motor neuron dysfunction in the spinal cord. Electron microscopic study revealed extensive glycogen particle accumulation, autophagic vacuoles and myelin figures in the muscle fibers.

Adolescent↗

Involvement of the Onuf nucleus in Werdnig-Hoffmann disease.

Contrary to contention that Onuf nucleus is spared in Werdnig-Hoffmann disease (WHD) as it is in ALS, we found central chromatolysis in the Onuf neurons of the sacral cord from all five WHD patients. They were less depopulated but the central chromatolysis appeared more frequently than in anterior motor neurons. In contrast, the sacral autonomic neurons were not affected in any of the five cases. This argues against the view that the Onuf nucleus is autonomic and is spared with other autonomic neurons.

Anterior Horn Cells↗

Adult form acid maltase deficiency -- a case report.

The case of a 26 year old man with acute respiratory difficulty was reported. Morphological and biochemical analysis of biopsied gastrocnemius muscle indicated a diagnosis of adult form acid maltase deficiency. Clinically, the most interesting point of our case was the presence of a thickening of the posterior papillary muscles and chordae without any functional disturbance, which was detected by echocardiogram. Another interesting point of our case was the existence of a sibling who died of progressive muscular dystrophy at the age of 31 years. This may raise the possibility that we are dealing with a familial type of adult form acid maltase deficiency.

Adult↗

Intracytoplasmic vacuoles in alpha W fibers of dystrophic chicken muscle--probable early pathologic event initiates massive fiber necrosis.

An electron-microscopic study on dystrophic chicken white muscle, posterior latissimus dorsi (PLD), was performed with histochemical identification of three fiber types of beta R (red), alpha R and alpha W (white) fibers to evaluate the pathophysiology in fiber necrosis. As seen in histochemically stained sections, vacuolar formation in the cytoplasm, an outstanding pathologic feature in chicken dystrophy, was recognized in the alpha W fibers by electron microscopy. The vacuole was membrane-bound and thought to originate from coalescence or dilatation of extensively proliferated sarcotubular system. There was evidence of a delay in fiber type transformation from alpha R to alpha W in dystrophic white muscle, while the initial pathologic event of sarcotubular system proliferation might be expressed only after muscle fibers had attained histochemical characteristics of alpha W fibers. Localized myofibrillar degeneration was encountered in the vicinity of the vacuole with focal membrane defect. An influx of extracellular fluid through the vacuolated sarcotubular system into the sarcoplasm may activate certain proteases, such as calcium-dependent protease because the extracellular fluid contains high concentration of calcium ion. The activated protease then degrades structural protein, especially Z-line protein, followed by fiber necrosis with phagocytosis.

Animals↗

Familial distal myopathy with rimmed vacuole and lamellar (myeloid) body formation.

Three cases from 2 families had muscle weakness with predilection for distal extremities, predominantly affecting the tibialis anterior muscles, and onset in early adulthood. The disorder seemed to be inherited through an autosomal recessive trait. The EMG demonstrated a myopathic pattern and CPK was mildly elevated. The striking finding in their muscle biopsies was the presence of "rimmed" vacuoles which had acid phosphatase-positive autophagic activity and which contained numerous concentric lamellar bodies in various forms (myeloid and cabbage bodies). Despite rapid clinical progression, not only necrotic fibers with phagocytosis, as seen in Duchenne dystrophy, but also evidence of regeneration were virtually absent. Continuous destruction of myofibrils by activation of certain lysosomal proteolytic enzymes might be responsible for the production of atrophic fibers.

Adult↗

Alexander disease: clinical, electrodiagnostic and radiographic studies.

A 10-month-old boy with Alexander disease is described. He was clinically characterized by early onset of megalencephaly, psychomotor retardation, spasticity and recurrent seizure attacks. Pathological examination of the biopsied cerebrum revealed a large number of Rosenthal fibers in the white matter and beneath the pia in association with advanced demyelination. The motor nerve conduction velocity was remarkably delayed, suggesting a possible change of the peripheral nerve. The computerized tomography demonstrated megalencephaly and bilateral symmetrical low density areas in the cerebral white matter, particularly in the frontal region. The preferential involvement of frontal lobes was also confirmed by electroencephalogram and brain scan. The preferential damage of the frontal region in the early stage of the disease may be an important clue to a diagnosis of Alexander disease by computerized tomography, brain scan and electroencephalogram.

Brain↗