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Biomedical subjects

M Momoi

Publications and source records attributed to M Momoi.

At least 37 records · Page 2Linked to original sources

Role of ADF/TRX and its inhibitor on the release of major basic protein from human eosinophils.

Adult T cell leukemia-derived factor (ADF)/Thioredoxin (TRX), originally defined as an IL-2 receptor alpha-chain/p55 inducer, has many cytokine-like activities. We reported that the release of major basic protein (MBP) from mature eosinophils stimulated with cytochalasin B and C5a were augmented after preincubation with recombinant ADF/TRX. The addition of a TRX specific inhibitor, BE40644, suppressed the augmentation of MBP release from mature eosinophils. It is suggested that BE40644 is applicable in allergic diseases associated with eosinophils.

Benzoquinones↗

Hepatocyte growth factor specifically expressed in microglia activated Ras in the neurons, similar to the action of neurotrophic factors.

Hepatocyte growth factor (HGF) mRNA and its receptor (c-Met) mRNA were detected in the fetal and adult rat brain. Expression of c-Met mRNA was increased after birth. HGF mRNA was preferentially expressed in the microglia of the rat brain, while c-Met mRNA was expressed in neurons as well as astrocytes and microglia. Most of the neurons were c-Met positive, and HGF stimulated tyrosine phosphorylation of c-Met (140-kDa) in the neurons. HGF as well as bFGF also activated Ras in the neurons. These results suggest that HGF plays a biological role as one of the neurotrophic factors in the brain.

Animals↗

c-jun inhibited the alternative splicing of neuron-specific amyloid precursor protein, but stimulated the non-neuron type one in P19 EC cells.

Three alternative splicing products of amyloid precursor protein (APP), APP770, 751 and 695, were detected in mouse embryonal carcinoma (EC) P19 cells by reverse transcriptase RNA polymerase chain reaction (RT-PCR). Alternative splicing of APP pre-mRNA in P19EC cells was remarkably changed by c-jun transformation. The relative ratio of APP770 encoding exons 7 and 8, non-neuron type, was increased by c-jun transformation, while that of APP 695 not encoding exons 7 and 8, neuron-specific one, was decreased. These results suggested that skipping of exons 7 and 8 was specifically blocked in c-jun transformed cells. APP 695, which increases in P19 EC cells under the culture conditions that induce the neuronal differentiation, did not increase in C2C5 cells under the same conditions, suggesting that c-jun transformed cells were not in the neuronal cell lineage and lost the ability to differentiate into neurons.

Alternative Splicing↗

Retinoic acid ambivalently regulates the expression of MyoD1 in the myogenic cells in the limb buds of the early developmental stages.

The expression of MyoD1 in myogenic cells located in the muscle prospective region of the limb bud at stage 20-22 was highly sensitive to retinoic acid. Unlike RAR-beta, the expression of MyoD1 mRNA in the muscle precursor cells was significantly increased by retinoic acid at lower concentrations (0.1-10 nM), but inhibited by it at higher concentrations (0.1-1 microM). The ambivalent modulation of MyoD1 expression suggested that MyoD1 expression is regulated by not only the retinoic acid receptor and its response element, but also by other factors. Retinoic acid may be involved in the differentiation of the myogenic cells during early development.

Animals↗

Activin synergistically increased c-jun mRNA in P19 embryonal carcinoma cells in the presence of retinoic acid.

Activin and retinoids, which are involved in the induction and regulation of the early differentiation process in vertebrate embryogenesis, synergistically increased the amount of c-jun mRNA in P19 embryonal carcinoma cells, but activin alone had no effect. Among the retinoids, all-trans-retinoic acid most effectively increased c-jun mRNA. Activin (lng/ml) was sufficient to induce the synergistic increase of c-jun mRNA in P19 EC cells with all-trans-retinoic acid. The synergistic increase of the amount of c-jun mRNA by their cooperative action may be important in vertebrate development.

Activins↗

[A case of generalized komuragaeri disease (Satoyoshi disease) treated with glucocorticoid].

Generalized komuragaeri disease (Satoyoshi disease) is a rare disorder of unknown etiology, characterized by painful muscle spasms, alopecia, diarrhea and various endocrine disorders. We administered glucocorticoid to a girl with this disease, resulting in a marked improvement of all clinical features. The patient was a 15-year-old girl. Since the age of 13 years, she had had intermittent painful muscle spasms, which affected any skeletal muscles 5 to 15 times a day at exercise and at rest and lasted for a few minutes. At the age of 14 years, she had idiopathic thrombocytopenic purpura which responded to the glucocorticoid treatment. Amenorrhea and orthostatic hypotension developed at the age of 14 years. Then the loss of body and head hair was noticed and progressed slowly. She had not experienced severe diarrhea. On admission, her physical and neurological examinations showed no abnormalities except for the thin hair and frequent muscle spasms. Laboratory examinations showed elevated levels of serum creatine kinase and aldolase, positive antinuclear antibody of speckled pattern and a mild disturbance in carbohydrate absorption. Endocrinological tests suggested the dysfunction of hypothalamus as a cause of amenorrhea. Electromyogram showed large action potentials on spasms. She was treated with glucocorticoid, 2 mg/kg on alternate days. The muscle spasms decreased gradually in frequency and duration in 1 month of treatment, and disappeared in 4 months. The growth of her hair was noticed and orthostatic hypotension disappeared in 4 months. Menstruation became regular in 7 months. The muscle spasms worsened when the dosage of glucocorticoid was reduced, and they improved on the increased dosage. She was free of symptoms at 6 months after the successful diminution of glucocorticoid. The etiology of this disease has not been revealed. The association of autoimmune disorders and the responsiveness of all clinical features to glucocorticoid suggest that an autoimmune process is involved in the pathogenesis of generalized komuragaeri disease.

Adolescent↗

Expression of cellular retinoic acid binding protein in the developing nervous system of mouse embryo.

The expression of cellular retinoic acid binding protein, CRABP, in developing mouse embryos was immunohistochemically analyzed. Differentiating young neurons and neuronal fibers in the myelencephalon, metencephalon, mesencephalon and spinal cord in 10.5- and 12.5-day embryos showed intense expression of CRABP, but undifferentiated cells in the neural tube did not. Neural tissue in 16.5-day embryos expressed less amount of binding protein than the tissues of the younger stages. These expressions of CRABP suggest that retinoic acid participates in neurogenesis at early developmental stages via expression of cellular retinoic acid binding protein.

Animals↗

Spatial and temporal expression of cellular retinoic acid binding protein (CRABP) along the anteroposterior axis in the central nervous system of mouse embryos.

In the central nervous system of 11.5-day mouse embryos, the expression of CRABP was spatially restricted to the anteroposterior axis. CRABP was most strongly expressed in the rhombencephalon and the anterior part of the neural tube. In 14-day mouse embryo, CRABP drastically decreased in the brain and the anterior part of the neural tube. The transient expression and spatial distribution of CRABP in the central nervous system strongly suggest that retinoic acid is involved in the neurogenesis during development.

Animals↗

Retinoic acid receptor in the chick limb buds in the early developmental stages.

Two retinoic acid-binding proteins, a high molecular weight one (90-100 kDa) (peak A) and CRABP (peak B), were obtained on gel filtration column chromatography of extracts of limb buds of chick embryos. The presence of a retinoic acid receptor (RAR) (45 kDa) and the absence of chick-CRABP type II (16.2 kDa) in the peak A fractions suggested that the 45 kDa RAR forms a homo- or hetero-dimeric structure (90-100 kDa) with other RARs or other nuclear proteins, but not with chick-CRABP type II, in the limb buds of chick embryos. We also demonstrated that there were no significant differences in the amount of RAR in the anterior, middle and posterior parts of limb buds (stages 23-25).

Animals↗

Multi-institutional survey of the Rett syndrome in Japan.

The results of the first multi-institutional survey of the Rett syndrome in Japan are reported. The survey was performed during 1985 and 1986. Eighty-nine cases were collected, of which 54 cases were confirmed to have the Rett syndrome. The ages of the patients ranged between 1 and 26 years. The clinical onsets occurred after 18 months of age in 28 cases, and before the age of one year in 26. No familial cases nor consanguinity was found. The incidence of perinatal abnormalities among the patients was not significantly higher than in other diseases in which no perinatal factors are involved.

Adult↗

Multi-institutional survey of the Aicardi syndrome in Japan.

The first multi-institutional survey of the Aicardi syndrome in Japan was performed during 1985 and 1986. Among the 20 collected cases, 9 fulfilled the typical clinical triad; infantile spasms, agenesis of the corpus callosum and chorioretinal lacuna. Three cases had agenesis of corpus callosum and chorioretinal lacuna. Five cases had agenesis of the corpus callosum and infantile spasms. We classified 12 cases with both agenesis of the corpus callosum and a lacuna as typical cases, and the remaining 8 cases as atypical cases. No familial cases were found among either the typical or atypical cases. The presence of the vertebral anomalies or other anomalies in the atypical cases, which were frequently observed in the typical cases, suggested that unknown common processes were affected in both the typical and atypical groups.

Agenesis of Corpus Callosum↗

Expression of cellular retinoic acid binding protein II (chick-CRABP II) in the chick embryo.

We previously demonstrated the presence of cellular retinoic acid binding protein II, chick-CRABP II, in chick embryos. In the present study, we investigated the distribution of chick-CRABP II in 14-day chick embryos by means of immunoblot analysis. Chick-CRABP II was expressed in skin, muscle, bone with tendon of the embryos, but not expressed in the nervous system. In adult chick tissues, chick-CRABP II was not detected on immunoblotting; Chick-CRABP II in adults amounts to less than 10 ng/mg soluble protein. These observations suggest that chick- CRABP II is an embryonic protein involved in the development of specific tissues, such as bone, muscle and skin.

Animals↗

The presence of a novel cellular retinoic acid-binding protein in chick embryos: purification and partial characterization.

Two cellular retinoic acid binding proteins, CRABP I and II, which behaved differently on a DEAE-cellulose column, were purified from 14-day chick embryos. Their molecular weights were 15.8 kDa and 16.2 kDa, respectively. NH2-terminal 36 amino acid sequence of CRABP I was identical to that of bovine CRABP, which was reported previously. CRABP II was a novel cellular retinoic acid binding protein, in which the amino acids at 6 positions of the NH2 terminal sequence are different from those in CRABP I. The homology between CRABP I and II was more than 83%.

Amino Acid Sequence↗