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Kayoko Saito

Publications and source records attributed to Kayoko Saito.

27 records · Page 2Linked to original sources
PubMed2003

Continuous culture of novel mitochondrial cells lacking nuclei.

We isolated stable cell lines, designated as mitochondrial cells, from cybrids obtained by fusing mitochondria-less HeLa cells with platelets from patients with Leigh syndrome, a subtype of mitochondrial encephalomyopathy. The cells contain a pathogenic point mutation, T9176C, in the mitochondrial DNA. Hematoxylin-eosin staining, confocal fluorescent microscopy and flow cytometry in fixed or living cells showed that the majority of these mitochondrial cells lack nuclear DNA and nuclei, but contain active mitochondria. Despite the absence of nuclear DNA, these cells can be continuously generated in culture. Therefore, it is likely that they arise from the minority of cells which possess a nucleus.

Journal Article↗
PubMed2003

Aberrant neuronal migration in the brainstem of fukuyama-type congenital muscular dystrophy.

We examined the brainstem of 10 patients with Fukuyama-type congenital muscular dystrophy (FCMD). In the midbrain we noted leptomeningeal glioneuronal heterotopia (LGH) (n = 9) and intramural "micropolygyria" (n = 1) in the tectum, as well as tyrosine hydroxylase-positive ectopic neurons/fibers ventral to the cerebral peduncle (n = 3). In the pontomedullary region, glial fibrillary acidic protein-positive subpial tissue intermingled with neurons and myelinated fibers was present in the ventrolateral pontine surface in all cases and extended over the lateral surface of the upper medulla oblongata. This subpial gliotic band was often contiguous with the extra-pial LGH tissues. The gliotic band protruded from the ventrolateral pontine surface in 3 cases and appeared to include ectopic neurons of the pontine nucleus. Disarrangement of the arcuate nuclei (n = 3) was also noted in the medulla oblongata. We hypothesize that both the radial and tangential neuronal migration systems are disrupted in the FCMD brainstem in addition to altered neuronal migration in the cerebral and cerebellar cortex. Fukutin protein may play a part in the morphogenesis of certain neuronal structures in the brainstem and the dysplastic structure termed "aberrant pyramidal tract" in previous reports may essentially result from an ectopic migration of pontine nucleus neurons.

Adolescent↗
PubMed2003

[Nation-wide survey on muscle glycogen storage disease (MGSDs) and comparison with our experiences in diagnosis of MGSDs].

To clarify the actual frequency of each type of muscle glycogen storage diseases (MGSDs) in Japan, we performed nation-wide survey in 2001. We compared the results with our diagnostic experiences at Hamamatu City Medical Center for Developmental Medicine. The majority (approximately 80%) of the MGSDs consisted of type II, V and III in Japan. In our experiences, most of the patients were diagnosed by the assays of glycolytic enzyme activities using biopsied skeletal muscles. However, the biochemical diagnoses of MGSDs type II, III, IV, and IX can be made using blood samples. Additionally, common genetic mutation (708/709 delTTC) of myophosphorylase gene has been found approximately in 50% of the Japanese patients with MGSDs type V. Therefore, approximately 70% of the MGSDs may be diagnosed by biochemical and genetic analysis using blood samples. Additional survey on McArdle's disease showed that the onset of muscle symptoms in McArdle's disease were variable, however, fixed muscular symptoms such as muscle weakness and muscle atrophy were present in 45% of patients.

Adolescent↗
PubMed2002

Fukutin expression in glial cells and neurons: implication in the brain lesions of Fukuyama congenital muscular dystrophy.

Expression and localization of fukutin, a gene responsible for Fukuyama congenital muscular dystrophy (FCMD), was studied in the central nervous system by in situ hybridization and immunohistochemistry. In control cases, glial cells expressed fukutin and the expression continued from fetuses to adults. Double immunostaining revealed that some of these cells were astrocytes. The glia limitans was stained by immunohistochemistry. In contrast, neuronal expression was decreased with neuronal maturation. The glia limitans formed by endfeet of astrocytes is abnormal in the brain of fetal to adult FCMD cases. These findings suggest an important role of astrocytes for the genesis of FCMD brain, although immature neurons expressed fukutin. In FCMD cases, expression of fukutin looked decreased. In the brain of fetal FCMD cases, decreased expression of fukutin is considered to provoke the disruption of glia limitans. In post-natal FCMD cases, prominent superficial gliosis is observed in the cerebral surface, where fukutin was weakly positive. Reactive increase of astrocytes may be required to maintain the glia limitans for compensating the decrease of fukutin expression in individual astrocytes. In the cerebellum, Bergmann glia, which did not express fukutin in control cases, elongated their cytoplasmic processes to the surface to form glia limitans even in the polymicrogyric area.

Adolescent↗
PubMed2002

A review of functional and structural components of the respiratory center involved in the arousal response.

State-dependent changes influencing both the central chemoreceptor and vagal inputs to respiratory neurons may provide useful markers to assess some intrinsic factors of the respiratory center. In this paper we discuss the following topics from our recent experiences, and their relevance to the assessment of sleep-related phenomena. (1) 'Post-sigh' apnea appears predominantly during non-REM sleep in control subjects, and is a potential marker of respiratory dysfunction during this stage of sleep. (2) The disarranged configuration of the arcuate nucleus in Fukuyama-type congenital muscular dystrophy may represent a disturbance in the tangential migration pathway in the brainstem, and may be related to the sudden death that is common in this disorder. The maldevelopment of the arcuate nucleus in the victims of sudden infant death syndrome (SIDS) may also be related to some abnormality in the differentiation and migration of this neuronal population. (3) The onset of hypoglossal nerve activity precedes inspiratory activity of the phrenic nerve, possibly representing a latent drive from the respiratory rhythm generator. These issues are not only related to respiratory rhythmogenesis itself, but are also important in understanding the pathological conditions of arousal responses.

Journal Article↗
PubMed2002

Hyperzincemia with systemic inflammation: a heritable disorder of calprotectin metabolism with rheumatic manifestations?

A boy had infantile-onset systemic inflammation, growth failure, hepatosplenomegaly, anemia, leukocytopenia, progressive muscular dystrophy, and hypercalprotectinemia, resulting in marked hyperzincemia. His mother had a history of chronic arthritis since childhood and also showed hypercalprotectinemia/hyperzincemia. We postulate an inherent defect in calprotectin metabolism.

Adolescent↗
PubMed2002

Oxidative stress in the brain of Fukuyama type congenital muscular dystrophy: immunohistochemical study on astrocytes.

Astrocytes in the cerebrum and medulla oblongata of cases of Fukuyama type congenital muscular dystrophy were examined by immunohistochemistry of oxidative modification products and free-radical scavenging enzymes because abnormal glia limitans formed by astrocytic end feet is considered to be involved in the genesis of brain lesions of Fukuywama type congenital muscular dystrophy. The study was performed on two fetal cases of Fukuyama type congenital muscular dystrophy of 18 and 20 weeks' gestation and seven patients with Fukuyama type congenital muscular dystrophy ranging in age from 2 to 27 years. Eight age-matched control cases were used. Polymerase chain reaction (PCR) was performed to ascertain the gene phenotype of two child cases, in which prenatal gene analysis was not performed. Astrocytes, especially layer I astrocytes, of postnatal cases of Fukuyama type congenital muscular dystrophy were weakly positivefor Nepsilon-(carboxymethyl)lysine and argpyrimidine, suggesting that they were sensitive to oxidative stress, and the accumulation may be related to the abnormal glia limitans. Secondary increase of manganese (Mn) superoxide dismutase against the increase of free radicals was considered in patients with Fukuyama type congenital muscular dystrophy more than 14 years old considered to be homozygous for founder haplotype: homozygosity was suggested by PCR in two cases. In contrast, expression of Mn superoxide dismutase was decreased in 2- and 6-year-old children with Fukuyama type congenital muscular dystrophy that were heterozygous. Moreover, accumulation of argpyrimidine was exclusively found in astrocytes of the 2-year-old child that exhibited severe brain lesions. Function of astrocytes might be impaired or immature in severe or heterozygous cases. These results may confirm that astrocytes play an important role in the etiology of the brain lesion.

Adolescent↗