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Biomedical subjects

I Nonaka

Publications and source records attributed to I Nonaka.

At least 415 records · Page 23Linked to original sources
PubMed1984

Childhood acid maltase deficiency. A clinical, biochemical, and morphologic study of three patients.

Three children, including two siblings and a patient with sporadic glycogenosis type II (childhood form of acid maltase deficiency [AMD] ), were studied clinically, biochemically, and morphologically. In addition to a delay in developmental milestones and mild generalized muscle weakness, nasal vocalization and an electromyographic finding of abnormal insertion voltage, followed by pseudomyotonic discharge, were assumed to be characteristic diagnostic findings for the childhood form of AMD. Since the neutral maltase activity was highest in the muscle biopsy specimen from the patient with the least severe weakness, the enzyme may play a role in reducing muscle involvement. Selective type 2A fiber atrophy and type 2B fiber deficiency in the affected muscles were the common histochemical findings in this particular form of AMD.

Adult↗
PubMed1984

A genetic variant of Emery-Dreifuss disease. Muscular dystrophy with humeropelvic distribution, early joint contracture, and permanent atrial paralysis.

A 38-year-old woman, a product of consanguineous parents, had been observed to have limited neck flexion and elbow joints contracture since early childhood. In addition, she experienced humeropelvic muscular weakness and atrophy, so that she was unable to walk by age 27. At 34 years of age, she required a permanent pacemaker to treat complete atrioventricular block with ventricular bradycardia. A myocardial biopsy confirmed cardiomyopathy. The clinical features of the present case are similar to those of the Emery-Dreifuss syndrome; however, this case may be inherited through an autosomal recessive trait.

Adult↗
PubMed1984

Regenerative capability of skeletal muscle in chicken muscular dystrophy.

To examine the morphological sequence of regenerating fibers after myonecrosis in dystrophic muscles, 0.5 ml of 0.5% bupivacaine hydrochloride (BPVC) (Marcaine) solution, a local anesthetic with a cytotoxic effect on the muscle fibers, was injected directly into the dystrophic (line 413) and nondystrophic (line 412) posterior latissimus dorsi (PLD) muscles of young and adult chickens. Although the dystrophic muscles after BPVC injection showed a rapid recovery with a similar tempo to that of nondystrophic ones, they showed different morphological behavior in the early phase of regeneration, including marked variability in the size of fibers and in the intracytoplasmic enzyme activities of nicotinamide adenine dinucleotide, reduced-tetrazolium reductase (NADH-TR), acetylcholinesterase (AChE), and nonspecific esterase (NSE).

Age Factors↗
PubMed1984

An electron microscopical study of the T-system in biopsied muscles from Fukuyama type congenital muscular dystrophy.

The behavior of the tubular system in muscles from six patients with Fukuyama type congenital muscular dystrophy (FCMD) was examined by electron microscopy using a lanthanum nitrate stain for a comparison with that in Duchenne muscular dystrophy (DMD). In FCMD, many fibers showed morphological changes of the T-system as follows: aggregated tubular components forming honeycomb-like structures, focal dilatation of T-tubules with tangle formation, and numerous longitudinally projecting tubules, which were quite similar to those found in cases with DMD. The fibers with abnormal T-systems occasionally showed ultrastructural characteristics of regenerating fibers, including excessive ribosome particles, immaturely organized myofibrils, and an increased number of internal nuclei and satellite cells. The present results suggested that there was no qualitative difference in the behavior of the T-system between FCMD and DMD, and the morphological changes of the T-system in dystrophic muscles were not primary lesions initiating myonecrosis but reflected the behavior of sarcotubular formation in the process of muscle regeneration.

Animals↗
PubMed1984

Muscle fiber type differentiation and satellite cell populations in normally grown and neonatally denervated muscles in the rat.

To examine the neural influence upon fiber type differentiation in developing muscles, newborn rats were subjected to sciatic nerve dissection, and the denervated extensor digitorum longus (EDL) (white) and soleus (red) muscles were examined in chronologic sequence by means of histochemistry and electron microscopy. The skeletal muscles in the newborn rats were undifferentiated (type 2C fibers seen on ATPase staining) and contained numerous myotubes. In the controls, the type 2C fibers started to differentiate at around 5 days and had almost completed type differentiation by 30 days in EDL and by 90 days in soleus muscles. On the other hand, none of the fibers in the neonatally denervated muscles developed into well differentiated type 1 and 2 A fibers, but both the EDL and soleus showed long-lasting type 2C and 2B populations. The satellite cells in the denervated EDL and soleus muscles decreased in number at the same rate as in the control muscles with maturation. The absence of a neural supply in the developing muscles induced a delay in muscle fiber type differentiation but did not influence the satellite cell populations in either EDL or soleus muscles.

Animals↗
PubMed1984

Clonal heterogeneity of thymic muscle-cell precursors.

Three myoid-cell clones were established from the thymuses of two Wistar rats; one thymus yielded two clones, R615A and R615B2, and the other yielded one clone, R613Ad. The three clones were divided into two subtypes. Both subtypes were able to form myofibrils, expressed AChR on their cell-surface membrane, and contained myofibrillar ATPase characteristic of undifferentiated type-2C fibers, but they differed from each other in morphology, expression of Thy 1 antigen, spontaneous contractility, and qualitative accumulation of AChR. Immunolocalization studies using antisera against the respective cell subtypes also indicated regional differences in their cellular origin. These results show that the thymus contains heterogenous myoid-cell precursors.

Animals↗
PubMed1984

Muscular abnormalities in experimental hypothyroidism of rats with special reference to the mounding phenomenon.

The mounding phenomenon was examined in vitro on the excised extensor digitorum longus or soleus muscle of hypothyroid rats. The mounding phenomenon was more prominent and lasted longer in hypothyroid muscles than in controls. In single skinned muscle fibers of both type 1 and type 2 from hypothyroid animals, the maximum tension produced by Ca ion was reduced and activity of Ca uptake by the sarcoplasmic reticulum was also decreased, judging from the response to caffeine. Decreased Ca uptake might retard the relaxation of contracture, thereby rendering the mounding more prominent. Morphological studies of both extensor digitorum longus and soleus muscles showed an increase of type 1 muscle fiber population as well as mild changes in arrangement of the internal membrane system. However, there was no muscle necrosis or other derangements. These results supported the idea that functional abnormality of the sarcoplasmic reticulum could be the basis of the exaggeration of the mounding phenomenon in hypothyroidism.

Animals↗
PubMed1984

Behavior of sarcotubular system formation in experimentally induced regeneration of muscle fibers.

To examine the behavior of transverse (T)-tubule formation in experimentally-induced regenerating fibers, a local anesthetic, bupivacaine hydrochloride, was injected directly into the rat soleus muscle to cause myonecrosis. The regenerating fibers following necrosis were then examined by electron microscopy using lanthanum nitrate which clearly demonstrated the sarcotubular system. In the early stage of regeneration within 7 days after muscle necrosis, the T-tubules seemed to be composed of markedly proliferated subsarcolemmal caveolae with occasional honeycomb structure formation. Around 10 days, the T-tubules in regenerating fibers were tortuously and irregularly arranged with focal dilatation in diameter, and extended longitudinally along the axis of well organized myofibrils. As the regenerating fibers matured, the sarcotubular system, irregular in course and in shape, gradually became organized into a regular transverse position against the myofibrils, along with a marked decrease in longitudinally arranged tubular components. These morphological findings of the early T-tubule formation seen in the present study were similar to those found in early myogenesis, and in biopsied muscles from cases of polymyositis and progressive muscular dystrophy.

Animals↗
PubMed1984

Fatal lipid storage disorder.

A 12-week-old female infant died from acute encephalopathy mimicking Reye syndrome. Because of positive serum hepatitis B surface antigen (HBs Ag) and perivascular inflammatory cell infiltration in the liver, she was diagnosed as having acute hepatitis. The most striking finding in the present case was extremely excessive lipid accumulation in the striated muscles including biceps brachii, tongue and cardiac muscles. The levels of serum, liver and muscle carnitine were within normal limits, though liver carnitine palmityl transferase (CPT) was markedly decreased in activity. Although the primary metabolic defect has yet to be elucidated, it is assumed that the fulminant hepatic failure induced lipid accumulation in the skeletal muscle by a certain abnormal lipid metabolism.

Carnitine O-Palmitoyltransferase↗
PubMed1984

6-Aminonicotinamide-induced hydrocephalus in suckling mice.

Following a single intraperitoneal injection of 6-aminonicotinamide (6-AN, 50 mg/kg of body weight) into newborn mice of the Institute of Cancer Research strain, hydrocephalus consistently developed nine days after injection, with rapid progression. All of these mice died before reaching adulthood. The most striking early histologic change in these mice was cytoplasmic vacuolation of ependymal cells, which was observed as early as 24 hours after injection. Vacuolation of subependymal astrocytes appeared during the next few days. After day seven, the aqueduct was obliterated by swollen vacuolated ependymal cells and subependymal astrocytes. The aqueduct remained obliterated even after the vacuolation of the ependymal cells subsided after day nine, when vacuolation of subependymal astrocytes was still pronounced. These morphological observations reveal that, in newborn mice, the ependymal cells are the most sensitive to the toxic action of 6-AN and suggest that the pathogenesis of 6-AN-induced hydrocephalus is likely to be due to the combination of ependymal cell damage and compression of the lumen by the edematous periaqueductal gray matter. This is a highly reproducible animal model of drug-induced hydrocephalus.

6-Aminonicotinamide↗
PubMed1984

Idiopathic hyperCKemia.

In three adult men, serum creatine kinase activity was constantly raised for at least 4 years. They had been normal in other neuromuscular functions and did not have any established disease. Quantitative morphologic and pharmacologic studies were performed on biopsied muscle. The biceps brachii of patient 1 contained 0.3% necrotic fibers. In patient 2, only slight variation of muscle fiber diameter was noted. Muscle of patient 3 contained a few small angular fibers, and 11% of fibers exhibited internal nuclei. Sensitivity to caffeine in vitro was increased in patients 2 and 3, as seen in survivors of malignant hyperthermia; patients in hyperCKemia may be susceptible to malignant hyperthermia.

Adult↗
PubMed1983

Malignant hyperthermia and related neuromuscular diseases: caffeine contracture of the skinned muscle fibers.

Using the skinned fiber preparation, the response to caffeine was studied on the skeletal muscle of malignant hyperthermia or other neuromuscular diseases. The sensitivity to caffeine was increased in the muscle of malignant hyperthermia. The sensitivity also was increased in Duchenne muscular dystrophy or asymptomatic patients with raised serum creatine kinase activity. Judging from the interaction between caffeine and the contractile system, the abnormal response originated from the sarcoplasmic reticulum in malignant hyperthermia. In Duchenne muscular dystrophy, the contractile system also might be involved in the increased sensitivity. Since the disease spectrum presenting abnormal responses is broad, it is suggested that muscle fibers become sensitive to caffeine when they are degenerating or regenerating.

Adolescent↗
PubMed1983

Pathophysiology of muscle fiber necrosis induced by bupivacaine hydrochloride (Marcaine).

A single direct injection of a local anesthetic, 0.5% bupivacaine hydrochloride (BPVC) (Marcaine), into rat soleus and extensor digitorum longus (EDL) muscles produced massive fiber necrosis with extensive phagocytosis followed by rapid regeneration, predominantly in the soleus. Since the sarcoplasmic reticulum (SR) was functionally disturbed by BPVC administration as confirmed by an in vitro study, the sarcolemmal lysis seen in the early phase of degeneration was not assumed to simply result from direct damage to the plasma membrane caused by BPVC. The extracellular fluid containing a high concentration of calcium (Ca) ions then permeated into the sarcoplasm through the defective membrane resulting in hyper-contracted myofibrils. Selective damage to the Z-line, an early sign of muscle degeneration, was shown by electron microscopy and SDS gel electrophoresis (preferential loss of alpha-actinin). Administration of leupeptin, a thiol protease inhibitor, proved to be ineffective in inhibiting the necrotic process, because the BPVC induced muscle fiber breakdown was probably too acute and fulminant to demonstrate the inhibitory effect upon the degenerative process. Well preserved satellite cells, peripheral nerves, and acetylcholinesterase activity, and the absence of fibrous tissue proliferation in this system may be responsible for the extremely rapid regeneration with complete muscle fiber type differentiation. Since the sequence of fiber breakdown induced by BPVC administration was similar to that of progressive muscular dystrophy, this chemical will be one of the most useful tools for studying the pathophysiology of fiber necrosis and regeneration in diseased muscle.

Animals↗