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Biomedical subjects

I Nonaka

Publications and source records attributed to I Nonaka.

At least 91 records · Page 5Linked to original sources
PubMed2000

Necrotizing myopathy in a patient with chronic hepatitis C virus infection: a case report and a review of the literature.

We describe a 61-year-old man presenting with necrotizing myopathy associated with chronic active hepatitis due to hepatitis C virus (HCV) infection. Thirteen patients with HCV-associated myopathy have been reported previously. In most of these cases, varying degrees of inflammatory changes were observed in the muscle tissue. In 2 patients, myopathy developed after initiation of interferon therapy for chronic HCV hepatitis. Our case was unusual due to long-standing elevation of creatine kinase values which improved following interferon therapy and the non-inflammatory features of the muscle tissue where the HCV RNA minus strand, a marker for replicative intermediates of the virus, was undetectable. The association of myopathy with HCV infection might represent a unique clinical entity, although the underlying pathological mechanisms remain unknown.

Biopsy↗
PubMed2000

Histochemical responses of human soleus muscle fibers to long-term bedrest with or without countermeasures.

Effects of 2- or 4-month bedrest in -6 degrees head-down tilt position with or without countermeasures on the histochemical properties of fiber phenotype and cross-sectional area (CSA) were studied in human soleus. The CSAs in slow fibers decreased approximately 32% during 4-month bedrest. This reduction was normalized after 1-month recovery. Although the reduction of percent slow fibers was not significant statistically, the percent intermediate fibers was significantly elevated 4 months after bedrest. Such shift in fiber type was not normalized following 1-month recovery. Effects of wearing an anti-g Penguin suit which has a modest, but continuous resistance at the knee and ankle (Penguin-1) or with knee resistance without loading on the ankle (Penguin-2) for 10 consecutive hours daily were also investigated during approximately 2 months of bedrest. The subjects performed knee extension and flexion for the last 15 min of each hour while in a supine position in bed. Bedrest-induced fiber atrophy was prevented in the Penguin-1 group but not the Penguin-2 group. Transformation of fiber type was not prevented in either Penguin suit group. It is suggested that long-term bedrest causes an atrophy and a shift of fiber phenotype toward fast-twitch type in human soleus. Data also indicated that loading on the muscle is an effective countermeasure for prevention of fiber atrophy but not fiber-type transformation.

Adult↗
PubMed2000

[A case of riboflavin-responsive multiple acyl-CoA dehydrogenase deficiency (glutaric aciduria type II)].

We reported a male infant with multiple acyl CoA dehydrogenase deficiency, probably due to electron transfer flavoprotein dehydrogenase deficiency. He was noted to have severe muscle weakness, a high serum creatine kinase (CK) level up to 6920 IU/L, lipid storage myopathy and fatty liver at 6 months of age. A GC/MS analysis of urinary organic acids showed excess excretion of dicarboxylic acids, including glutaric, 2-hydroxyglutaric, adipic, suberic, sebacic, malonic, ethylmalonic and methylsuccinic acids. On a urinary acylglycine analysis, hexanoylglycine and suberylglycine were increased, but not isovalerylglycine, in amount. No ketosis was noted. The muscle pathology showed increased oil-red O positive lipid droplets of various sizes indicative of lipid storage myopathy. There was diffuse decrease in the activity of cytochrome c oxidase. No ragged-red fibers were noted. His clinical symptoms improved remarkably after the administration of riboflavin (100 mg/day) and L-carnitine (1000 mg/day). He was then diagnosed as having probable riboflavin-responsive multiple acyl-CoA dehydrogenase deficiency. The glutaryl CoA dehydrogenase activity in lymphocytes was normal, as were the alpha- and beta-subunits of electron transfer flavoprotein. These findings led us to suspect electron transfer flavoprotein dehydrogenation deficiency. Although he had several episodes of short-term deterioration in clinical and laboratory findings, he developed normally with normal intelligent till 10 years of age.

Acyl-CoA Dehydrogenases↗
PubMed2000

A novel congenital myopathy with apoptotic changes.

We report on a female child with congenital myopathy with delayed developmental milestones and mental retardation. The most striking pathological finding was the presence of many condensed to fragmented myonuclei. DNA fragmentation was confirmed by the TUNEL method and supported by the ultrastructural characteristics of apoptotic nuclear changes. We also demonstrated immunohistochemically the activation of caspase-3 and caspase-9. This appears to be the first reported case of congenital myopathy with apoptotic process.

Apoptosis↗
PubMed2000

[Preliminary report: first identification of known mutation in the ryanodine receptor gene in a Japanese malignant hyperthermia pedigree].

In Japan, the rate of Ca-induced Ca release (CICR) using skinned fibers of skeletal muscle has been employed as a diagnostic test for malignant hyperthermia (MH) susceptibility, since most of the typical fulminant MH patients showed an enhancement of CICR rate. Recently the Ca releasing channel responsible for the CICR was reported to be mainly the ryanodine binding Ca protein which was identified as the causative site of MH muscle according to recent genetic studies. Among patients with enhanced CICR rate, one point mutation for Arg 2434 His was recognized in a family. Although this site is related to the central core disease (CCD), this pathological change could not be observed in this patient. This is the first report describing a gene mutation in a MH family identified in Japan.

Asian People↗
PubMed2000

Mitochondrial neurogastrointestinal encephalomyopathy: an autosomal recessive disorder due to thymidine phosphorylase mutations.

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an autosomal recessive disorder defined clinically by severe gastrointestinal dysmotility; cachexia; ptosis, ophthalmoparesis, or both; peripheral neuropathy; leukoencephalopathy; and mitochondrial abnormalities. The disease is caused by mutations in the thymidine phosphorylase (TP) gene. TP protein catalyzes phosphorolysis of thymidine to thymine and deoxyribose 1-phosphate. We identified 21 probands (35 patients) who fulfilled our clinical criteria for MNGIE. MNGIE has clinically homogeneous features but varies in age at onset and rate of progression. Gastrointestinal dysmotility is the most prominent manifestation, with recurrent diarrhea, borborygmi, and intestinal pseudo-obstruction. Patients usually die in early adulthood (mean, 37.6 years; range, 26-58 years). Cerebral leukodystrophy is characteristic. Mitochondrial DNA (mtDNA) has depletion, multiple deletions, or both. We have identified 16 TP mutations. Homozygous or compound heterozygous mutations were present in all patients tested. Leukocyte TP activity was reduced drastically in all patients tested, 0.009 +/- 0.021 micromol/hr/mg (mean +/- SD; n = 16), compared with controls, 0.67 +/- 0.21 micromol/hr/mg (n = 19). MNGIE is a recognizable clinical syndrome caused by mutations in thymidine phosphorylase. Severe reduction of TP activity in leukocytes is diagnostic. Altered mitochondrial nucleoside and nucleotide pools may impair mtDNA replication, repair, or both.

Adult↗
PubMed2000

[Lysosomal glycogen storage disease with normal acid maltase (Danon) without apparent cardiomyopathy and mental retardation].

A 29-year-old male who had a past history of mild ECG abnormality of arrhythmia at the age of 14 years, was referred to our hospital because of elevated serum creatine kinase (CK) level. He had never been aware of muscular weakness nor cardiac symptoms. Neurological examination revealed normal muscle strength of all extremities except marked back muscle weakness. He had normal intelligence. On laboratory examination, serum AST, ALT, LDH, aldolase, CK and myoglobin levels were elevated. Both lactate and pyruvate levels were normally responded after an ischemic exercises test. Acid maltase activity was normal in white blood cells. A muscle biopsy obtained from rectus femoris muscle revealed vacuolar myopathy with mildly increased PAS positive material. On electron microscopy, there were autophagic vacuoles scavenging glycogen particles and cytoplasmic debris, and sarcolemmal indentation, compatible with the findings of lysosomal glycogen storage disease with normal acid maltase. This patient had unusual clinical features of absent mental retardation and no apparent cardiomyopathy. Accordingly, mental retardation is probably not necessary to see later onset of cardiac muscle involvement.

Adult↗
PubMed2000

[Two sibling patients with non-Fukuyama type congenital muscular dystrophy with low serum selenium levels--therapeutic effects of oral selenium administration].

We report a pair of siblings with non-Fukuyama type, merosin-positive congenital muscular dystrophy, born to unrelated parents. Patient 1 was a 16-year-old girl with myopathy, cardiomyopathy, severe mental retardation and epilepsy. Patient 2 was a younger brother of patient 1, a 10-year-old boy with myopathy, severe mental retardation and epilepsy. Their serum selenium levels were decreased to 25 micrograms/l and 55 micrograms/l, respectively (normal 97-147 micrograms/l). Their muscle biopsy findings were similar to those seen in selenium deficient myopathy, showing abnormal mitochondrial distribution and giant mitochondria. After oral administration of selenium for 3 months, their gait disturbance apparently improved, which was confirmed by a gait analysis system. Why their gait improved remain unclear, but a defect in selenium metabolism may play a role in the development of congenital muscular dystrophy and mental retardation.

Administration, Oral↗
PubMed2000

[Congenital nemaline myopathy with mitochondrial abnormalities. An adult case report].

We report a 42-year-old male suffering from congenital nemaline myopathy accompanied with mitochondrial abnormalities in his muscle biopsy. He had a dysmorphic face with a high-arched and narrow palate and slowly progressive generalized muscle weakness. He was still able to walk with a cane. CT showed symmetrical muscle atrophy and low densities in the thigh muscles, especially in the posterior compartment, and in the soleus muscles. Preferential posterior thigh involvement was unusual in congenital nemaline myopathy. The lumbar quadrate and paravertebral muscles were relatively well preserved; these muscles were reported to be severely involved in adult-onset nemaline myopathy patients. Muscle biopsy findings were consistent with nemaline myopathy; nemaline rods in approximately 10% of fibers, type 1 fiber atrophy, and type 2B fiber deficiency. In addition, ragged-red fibers were scattered and focal cytochrome c oxidase (CCO) deficiency was present. Formazan granules were large on succinate dehydrogenase stain. Many fibers with nemaline rods showed focal CCO deficiency. On electron microscopy, large (megaconial) mitochondria were lined regularly between Z lines. PCR and Southern blot analysis of muscle mitochondrial DNA revealed multiple deletions. It remains to be clarified whether mitochondrial abnormalities are primarily related to nemaline myopathy or secondarily induced phenomenon after a long-standing disease process.

Adult↗
PubMed2000

[A patient of infantile polymyositis triggered by respiratory syncytium virus infection].

An 11-month-old boy developed acute polymyositis about 1 week after respiratory syncytium virus (RSV) pneumonia. He was admitted to our hospital because of interstitial pneumonia. RSV infection was confirmed by the presence of its antigen in his nasal discharge. Two weeks later, his chest X-ray findings improved and RSV antigen became negative, but severe generalized muscle weakness developed, causing respiratory failure. Muscle biopsy demonstrated inflammatory cellular infiltration with occasional fiber necrosis. Intravenous steroid pulse therapy was remarkably effective resulting in complete recovery of his muscle power. In this patient polymyositis was preceded with RSV infection, suggesting a close relationship between polymyositis and RSV infection. Although many patients of viral myositis have been reported to be associated with coxsackie B, HCV and HTLV-1 viruses, our patient is the first infantile polymyositis secondary to RSV infection.

Acute Disease↗
PubMed2000

[Myositis and rhabdomyolysis with influenza infection].

Myositis and rhabdomyolysis with influenza are rare, but sometimes serious complications. Patients with myositis more commonly have influenza B infection than influenza A. On the other hand, rhabdomyolysis are more frequently recognized in patients with influenza A infection than those with influenza B. Upper respiratory symptoms usually precede myositis, while rhabdomyolysis occurs simultaneously or shortly after the respiratory symptoms. Creatine kinase levels are elevated in myositis mildly and in rhabdomyolysis markedly. Influenza myositis improve spontaneously within 6 weeks, but influenza rhabdomyolysis sometimes induce renal failure with fatal outcome. Although the true incidence of myositis and rhabdomyolysis in the influenza infection remains unknown, careful medical care is necessary when patients have muscle pain and weakness.

Adolescent↗
PubMed2000

[Muscle involvement of Stormorken's syndrome].

We described two patients, a mother and daughter, of Stormorken's syndrome. The syndrome is characterized clinically by autosomal dominant inheritance, congenital miosis, thrombocytopenia, asplenia and muscle weakness. Both patients had bleeding tendency, ichthyosis of arms, and muscle weakness. The daughter additionally had short stature (146 cm), low body weight (32 kg) and muscle cramp. Neurological findings of the patients included migraine-like headache, cognitive dysfunction, limitation of upward and lateral gaze, and amydriasis. Femoral muscle MRI of the daughter demonstrated decreased volume with patchy high intensity areas in the hamstrings. A muscle biopsy from the daughter showed myogenic changes with muscle fiber necrosis and regeneration, variation in fiber size, tubular aggregates in approximately 5% of fibers, and fibrous tissue proliferation. Dystrophin, dystrophin-associated proteins and dysferlin were normally expressed. Although both patients had elevated creatine kinase levels and generalized muscle wasting, muscle weakness was mild with slow progression. A certain membrane defect in the platelet and muscle fiber might be responsible for the pathogenesis of this syndrome.

Adult↗
PubMed2000

[Overloading to neck extensor muscles is an aggravating factor to induce further neck drop in isolated neck extensor myopathy (Katz). A case report].

A 78-year-old woman was hospitalized because of progressive anterior neck drop over 4 months prior to admission. She was normal except for mild weakness of her neck, trapezius and biceps brachii muscles. EMG revealed mild myopathic changes in the neck extensors, trapezius, deltoid and sternocleidomastoid muscles. Bilateral splenius capitis muscles had high intensities on T2-weighted and STIR pulse-sequenced MRI. However, there were no inflammatory changes in the right splenius muscle biopsy. Accordingly, the abnormal MRI finding seems not to result from an inflammatory process but from an physiological increase of intracellular water content due to sustained muscle contraction. Because apparent neuromuscular diseases responsible for neck drop were excluded, her clinical features met the criteria of isolated neck extensor myopathy (INEM, Katz). After strict bed-rest for one month, her neck drop improved dramatically. When she returned to the previous life style after discharge, her symptoms of the neck drop reappeared. Although the cause of INEM remains unclear, the present case indicates that the condition is reversible at least in the early stage of the disease, and the overloading to the neck extensor muscles is an aggravating factor of the neck drop in INEM.

Aged↗
PubMed2000

Muscle mitochondrial changes by experimental immobility and hindlimb suspension.

It is one of the key themata to investigate the circulatory, muscular, nervous and nutritional systems when humans stay for long time in the space environment in order to improve the safety and efficiency in manned space flight. It is well known that immobility and microgravity [correction of microgravidity] induce selective skeletal muscle atrophy. Previous experiments indicated red soleus muscle was selectively involved and the most striking finding was myofibrillar degeneration without necrosis or phagocytosis. This study is focused on the mitochondrial function in this degenerative process because red soleus muscle contains much mitochondria than white muscles, and mitochondrial changes may be closely associated with the core structure observed as the myofibrillar disorganization.

Animals↗
PubMed2000

Dependence of normal development of skeletal muscle in neonatal rats on load bearing.

Antigravity function plays an important role in determining the morphological and physiological properties of the neuromuscular system. Inhibition of the normal development of the neuromuscular system is induced by hindlimb unloading during the neonatal period in rats. However, the role of gravitational loading on the development of skeletal muscle in rats is not well understood. It could be hypothesized that during the early postnatal period, i.e. when minimal weight-supporting activity occurs, the activity imposed by gravity would be of little consequence in directing the normal development of the skeletal musculature. We have addressed this issue by limiting the amount of postnatal weight-support activity of the hindlimbs of rats during the lactation period. We have focused on the development of three characteristics of the muscle fibers, i.e. size, myonuclear number and myosin heavy chain expression.

Animals↗
PubMed1999

Mutations of calpain 3 gene in patients with sporadic limb-girdle muscular dystrophy in Japan.

Mutations of the calpain 3 gene, an intracellular calcium-activated neutral protease, is one of the causes of limb-girdle muscular dystrophy (LGMD). We examined 14 Japanese patients with sporadic LGMD for calpain 3 mutations, and found four mutations in five patients. Three (R461C, D707G and R147P) were novel missense mutations, and one was a splice-site mutation (801+1g-->a) resulting in skipping of exons 4 and 5. Of the five patients, three patients with homozygous missense mutations showed later onset and slower progression than the other two patients with an exon skipping or mRNA loss of unknown cause. It would appear that the occurrence of calpain 3 gene mutations in sporadic LGMD in Japan may be quite high since all five patients with mutations in this gene were among the 14 patients without apparent family history, an incidence of 36%. These findings also suggest that calpain 3 deficiency occurs in both sporadic and familial LGMD and that direct analysis of the calpain 3 gene may be useful in the definitive diagnosis not only of the 15q-linked familial but also of sporadic cases of LGMD.

Adolescent↗
PubMed1999

A case of McLeod syndrome with unusually severe myopathy.

A 51-year-old man developed weakness and muscle atrophy in the legs at the age of 41, later followed by choreiform involuntary movements. Neurological and laboratory examinations revealed severe muscle weakness and atrophy, and areflexia in all the extremities, acanthocytosis and an elevated serum creatine kinase level. Together with these findings, the weak expression of Kell blood group antigens and the absence of the Kx antigen led to a definite diagnosis of McLeod syndrome for his condition. Brain magnetic resonance imaging revealed marked atrophy of the head of the caudate nuclei. Although immunocytochemical analysis of dystrophin in muscle specimens from our patient revealed normal staining, we found prominent fiber size variability, central nuclei, and connective tissue proliferation as well as necrotic and regenerating fibers, which are as a whole compatible with the myopathology of muscular dystrophy. Moreover, muscle computerized tomography of the lower extremities revealed the 'selectivity pattern' characteristically reported in muscular dystrophies including Duchenne type muscular dystrophy. The muscular symptoms and pathology in McLeod syndrome have been reported to be mild, but the present case clearly shows that the muscular features in this condition may be much more severe than previously thought.

Acanthocytes↗