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Biomedical subjects

Akira Sudo

Publications and source records attributed to Akira Sudo.

12 recordsLinked to original sources
PubMed2005

Cochlear damage due to germanium-induced mitochondrial dysfunction in guinea pigs.

This investigation addressed the effect of germanium dioxide (GeO(2))-induced mitochondrial dysfunction on hearing acuity. Guinea pigs were fed chow that contained 0%, 0.15%, or 0.5% GeO(2). The animals that were fed 0.5% GeO(2) for 2 months developed hearing impairment chiefly due to degeneration of stria vascularis and cochlear supporting cells, which exhibited electron-dense mitochondrial inclusions. Cytochrome c oxidase activity was decreased in the skeletal muscles and kidney, which also exhibited electron-dense mitochondrial inclusions. No apparent pathological changes were observed in the utricle, semicircular canal, or among the vestibular nerve fibers, or in the liver or heart. The untreated animals and those treated with 0.15% GeO(2) did not exhibit hearing impairment or pathological changes in any organs. These findings suggest that administration of 0.5% GeO(2) induces mitochondrial dysfunction in the stria vascularis and supporting cells in the cochlea, as in the skeletal muscles and kidney, thereby causing hearing impairment in the guinea pigs.

Animals↗
PubMed2005

An infantile-juvenile form of Alexander disease caused by a R79H mutation in GFAP.

Alexander disease is a degenerative white matter disorder due to mutations in the glial fibrillary acidic protein (GFAP) gene. It has been classified into three forms based on the age of onset and severity: an infantile, a juvenile, and an adult form. In a 6-year-old patient with a relatively mild form of Alexander disease, we detected a common R79H mutation in GFAP, previously only described in the infantile form. These results suggest the need for further studies of the genotype-phenotype correlation.

Age of Onset↗
PubMed2005

Uniparental disomy and imprinting defects in Japanese patients with Angelman syndrome.

We examined 54 patients with deletion-negative Angelman syndrome (AS) using DNA methylation testing and microsatellite polymorphism analysis, and identified three patients with paternal uniparental disomy (UPD) and seven patients with imprinting defects (ID). The three patients with UPD were shown to have paternal isodisomy 15, which we hypothesized to have arisen from duplication of chromosome 15. Two of the patients with ID were siblings and carried microdeletions of the imprinting center (IC), while the remaining five patients had no evidence of deletions and represented sporadic cases. Two of the three patients with UPD and two of the seven patients with ID had not developed seizures. The only patients displaying microcephaly were those with ID who had microdeletions at the IC. These data support the previous findings that indicate that patients with UPD and ID may have a milder phenotype of AS.

Angelman Syndrome↗
PubMed2005

Dynamic statistical parametric mapping for analyzing the magnetoencephalographic epileptiform activity in patients with epilepsy.

Our current purpose is to evaluate the applicability of dynamic statistical parametric mapping, a novel method for localizing epileptiform activity recorded with magnetoencephalography in patients with epilepsy. We report four pediatric patients with focal epilepsies. Magnetoencephalographic data were collected with a 306-channel whole-head helmet-shaped sensor array. We calculated equivalent current dipoles and dynamic statistical parametric mapping movies of the interictal epileptiform discharges that were based in the minimum-L2 norm estimate, minimizing the square sum of the dipole element amplitudes. The dynamic statistical parametric mapping analysis of interictal epileptiform discharges can demonstrate the rapid change and propagation of interical epileptiform discharges. According to these findings, specific epileptogenic lesion-focal cortical dysplasia could be found and patients could be operated on successfully. The presurgical analysis of interictal epileptiform discharges using dynamic statistical parametric mapping seems to be promising in patients with a possible underlying focal cortical dysplasia and might help to guide the placement of invasive electrodes.

Adolescent↗
PubMed2004

Leigh syndrome caused by mitochondrial DNA G13513A mutation: frequency and clinical features in Japan.

The mitochondrial DNA (mtDNA) G13513A mutation in the ND5 subunit gene has been recently reported as a common cause of some phenotypes of mitochondrial myopathy. Until now, the prevalence and characteristics of this mutation in Leigh syndrome (LS) has not been determined. We screened 84 patients with Leigh syndrome (LS) and found the mutation in six (7%) of them. The proportions of mutant mtDNA in muscles were relatively low (42-70%). The onset of symptoms for patients with this mutation was from 9 months to 5 years. It should be noted that five patients had cardiac conduction abnormalities, particularly Wolff-Parkinson-White (WPW) syndrome (three patients). This study suggests that G13513A mutation is a frequent cause of LS and that patients with this mutation may have a characteristic clinical course.

Body Constitution↗
PubMed2003

Congenital monomelic neurogenic disorder with calf muscle hypertrophy.

An 8-year-old girl had hypertrophy of the right calf muscle since birth, with progressive ankle contracture and mild muscle weakness. Her right leg was 3 cm shorter than her left. Electromyography and biopsy of the affected muscle showed neurogenic changes. She also had neurogenic bladder and spina bifida occulta at the S1 level. We believe that the spina bifida was responsible for the neurogenic changes in her right calf, but could not find definite evidence for this association. Although cases with neurogenic muscle hypertrophy, especially calf muscle hypertrophy, have been reported, none of them was congenital or associated with spina bifida occulta.

Child↗
PubMed2003

Cerebellar and brainstem involvement in familial juvenile nephronophthisis type I.

We report on an 11-year-old boy with familial juvenile nephronophthisis type I associated with cerebellar ataxia and nystagmus, but not with ocular motor apraxia. An MRI revealed hypoplasia of the brainstem and vermis, and an enlargement of the fourth ventricle. A molecular genetic analysis demonstrated a homozygous deletion including the NPHP1 gene. These findings suggest that NPHP1 may play an important role in the normal development of the brainstem and the cerebellum as well as renal tissue.

Brain Stem↗
PubMed2003

High uptake on 11C-methionine positron emission tomographic scan of basal ganglia germinoma with cerebral hemiatrophy.

We herein describe a 12-year-old male patient with a germinoma of the basal ganglia who presented with progressive hemiparesis. MR imaging showed ipsilateral cerebral hemiatrophy predominantly in the left basal ganglia, whereas no mass or enhancement was depicted. Single photon emission CT revealed no significant uptake of thallium, whereas (11)C-methionine positron emission tomography showed clearly discernible uptake in the left putamen. Stereotactic biopsy, referencing the results of (11)C-methionine positron emission tomography, was performed, allowing histologic verification of germinoma to be established. (11)C-methionine positron emission tomography was the only technique that indicated the precise localization of the tumor in our patient and enabled biopsy-based final diagnosis of the basal ganglia germinoma without any overt mass formation.

Atrophy↗
PubMed2002

Germline mosaicism of a novel mutation in lysosome-associated membrane protein-2 deficiency (Danon disease).

We identified a family with lysosome-associated membrane protein-2 deficiency (Danon disease) associated with a novel 883 ins-T mutation in the lysosome-associated membrane protein-2 gene located at Xq24. Although the affected son and daughter carried the same mutation, it was not detected in their mother's peripheral blood or buccal cells; this indicated germline mosaicism. This is the first molecular evidence for germline mosaicism in Danon disease and has important implications for genetic counseling.

Adult↗
PubMed2002

[Overlap syndrome of systemic lupus erythematosus and dermatomyositis presented a large demyelinating subcortical lesion mimicking brain tumor and high level of CSF antineuronal and serum anti-ribosomal P antibodies].

We reported a 50-year-old man with an overlap syndrome of dermatomyositis and SLE, whose magnetic resonance image of the brain showed a rapidly increasing large tumor-like focal lesion unequally enhanced by Gd-DTPA in the left frontal lobe. Its pathological finding by the brain biopsy was fibrinoid necrosis, inflammatory cell aggregation around blood vessels and many myelin-laden macrophages with central necrosis. Although many cases of blood vessel injury are reported in CNS lupus, in this case the brain lesion partly took reversible course and neural symptoms such as paresis were slight and the lesion well responded to steroid. Moreover we considered that the measurement of serum anti-ribosomal P and CSF antineuronal antibodies are useful to diagnose cases as CNS lupus.

Autoantibodies↗