Biomedical subjects

T Momoi

Publications and source records attributed to T Momoi.

At least 109 records · Page 6Linked to original sources

PubMed1990

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↗

PubMed1990

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↗

PubMed1990

The syndrome of Möbius sequence, peripheral neuropathy, and hypogonadotropic hypogonadism.

We report on a 17-year-old Japanese boy with Möbius sequence, peripheral neuropathy, and hypogonadotropic hypogonadism, the fourth such case known to us. The association of peripheral neuropathy and hypogonadotropic hypogonadism in Möbius sequence seems to be more than coincidence. Pulsatile gonadotropin-releasing hormone administration for 3 months showed the effectiveness of this treatment for this patient.

Adolescent↗

PubMed1990

Neurohypophyseal function of an ectopic posterior lobe in patients with growth hormone deficiency.

We studied the neurohypophyseal function of 20 patients with complete GH deficiency owing to pituitary stalk transection by means of the water deprivation and the hypertonic saline infusion test. In T1-weighted magnetic resonance images, high-signal intensity of the posterior lobe of the hypophysis was missing in all the patients. An ectopic posterior lobe was observed at the proximal stump of the transected stalk in 17 patients, whereas the 3 patients without ectopic posterior lobe had overt diabetes insipidus or intractable nocturnal enuresis. After water deprivation, 3 patients with large ectopic posterior lobes (length along the pituitary stalk axis exceeding 5 mm) showed urinary osmolality and plasma AVP levels as high as those of 13 patients with partial GH deficiency in whom magnetic resonance images revealed no abnormalities. On the other hand, 14 patients with small ectopic posterior lobes (length less than 5 mm) showed significantly lower urinary osmolality and plasma AVP levels than the patients with large ectopic posterior lobes (p less than 0.01 and p less than 0.01, respectively) and the patients with partial GH deficiency (p less than 0.01 and p less than 0.01, respectively). Urinary osmolality in the patients with small ectopic posterior lobes, however, was higher than that in 3 patients without ectopic posterior lobes (p less than 0.01). During the hypertonic saline infusion test, peak plasma AVP levels in the patients with small ectopic posterior lobes were significantly lower than those in the patients with partial GH deficiency (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1989

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↗

PubMed1989

Cytochrome c oxidase--deficient myogenic cell lines in mitochondrial myopathy.

In a patient with mitochondrial myopathy, the defect of cytochrome c oxidase activity was restricted to some muscle fibers. To isolate cell lines with or without oxidase activity from a single muscle sample, primary cultured cells were transformed by replication origin-defective simian virus 40, and then cloned. The clones were examined by cytochemical staining for cytochrome c oxidase activity. Eight myogenic clones were completely devoid of activity, while the other myogenic and nonmyogenic clones were not. Deficiency of cytochrome c oxidase was stable in culture for at least a year after serial passaging. The amount of mitochondrial DNA in cytochrome c oxidase-deficient cells was the same as in control cells, and no deletion in the mitochondrial DNA was detected. Protein synthesis in mitochondria of the subunits of cytochrome c oxidase and subunit 6 of the ATP synthase complex was markedly decreased, whereas synthesis of the other subunits encoded by mitochondrial DNA was normal. These cloned cell lines provide an excellent system for clarifying the cause of mitochondrial myopathy and for investigating nuclear-mitochondrial genetic interaction.

Adolescent↗

PubMed1989

Wilms tumour in a patient with growth hormone replacement therapy.

Wilms tumour was found in a Japanese boy aged 5 years 9 months with isolated growth hormone (GH) deficiency and some congenital anomalies. He had received pituitary GH replacement therapy from the age of 2 years 1 month to 4 years 7 months and after a 1 year interval he received biosynthetic GH for 2 months until the tumour became clinically apparent. This was the sixth known patient with GH deficiency to develop a malignant neoplasm during or after GH replacement therapy and the first with a solid tumour in Japan since 1975, when treatment with pituitary GH for patients with GH deficiency was introduced.

Child, Preschool↗

PubMed1989

Developmental changes of plasma ganglioside concentration during the neonatal period.

We investigated the developmental changes of plasma ganglioside concentration during the neonatal period. The mean plasma ganglioside concentration at birth was 8.22 +/- 3.70 nmol lipid-bound sialic acid (LBSA)/ml, significantly lower than the value in adults (12.05 +/- 1.36 nmol LBSA/ml, P less than 0.02). However, it increased rapidly early in the neonatal period and reached its maximum level at 14 days of age (16.25 +/- 6.04 nmol LBSA/ml), which was higher than that of adults (P less than 0.05); then it decreased slowly to the adult level at one month of age. The mean plasma ganglioside concentration in preterm infants (gestational age less than 37 weeks) was 6.65 +/- 3.35 nmol LBSA/ml, somewhat lower than that of fullterm infants (gestational age greater than or equal to 37 weeks, 9.90 +/- 3.39 nmol LBSA/ml, P less than 0.02) at birth. After birth, it increased much more rapidly in preterm infants and there was no significant difference between these two groups at 5 days of age. Plasma ganglioside concentration at birth increased gradually in correlation with gestational age. Our investigations show that plasma ganglioside concentration may reflect the development and maturation of the central nervous system to some degree, at least early in the neonatal period.

Adult↗

PubMed1989

Leukocyte and plasma N-laurylsphingosine deacylase (ceramidase) in Farber disease.

Severe deficiency of acid ceramidase activity (4-5% of normal) was demonstrated in cultured skin fibroblasts, leukocytes and plasma from a 1-year-old boy who was diagnosed as being affected with Farber disease. Determination of ceramidase activity in plasma was achieved by a highly sensitive assay employing a ceramide substrate containing radiolabeled C12 N-acyl moiety (N-lauryl). The enzyme activity in the parents' leukocytes and plasma was found to be reduced to 18-47% of the respective normal values, and that determined in a plasma specimen from a patient with I-cell disease was about 4 times elevated above the normal level.

Acid Ceramidase↗

PubMed1989

Y chromosome specific DNA probe in the diagnosis of a patient with mos 45,X/46,XYnf.

In a patient with mos 45,X/46,XYnf, the diagnosis was confirmed with a Y chromosome-specific DNA probe, Y-190. The patient was a phenotypic female without Turner syndrome stigmata other than short stature. She showed some evidence of virilization and high serum testosterone. Her peripheral blood karyotype was mos 45,X/46X, +mar. Although this marker chromosome resembled a Y chromosome, there was no quinacrine bright region on its long arm. Southern blot analysis of her peripheral blood mononuclear cell DNA with Y-190 as a probe showed strong hybridization with this probe. Gonadectomy was performed, and bilateral gonadoblastomas were found.

Adolescent↗

PubMed1988

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↗

PubMed1988

Temporal and spatial expression of a position specific antigen, AV-1, in chick limb buds.

In a previous study, we demonstrated the presence of a position-specific antigen (AV-1) in chick limb buds at an early developmental stage. Here, we reported the temporal and spatial expressions and the biochemical characterization of the AV-1 antigen. Indirect immunofluorescence staining and immunoblot analysis clearly showed that the AV-1 antigen is a glycoprotein that is localized on the plasma membrane and that it is expressed from stage 19 and highly expressed at stages 22-26 in some middle-distal to anterior-distal region of limb buds. In the wing bud, at stage 28, the AV-1 antigen was faintly detected in the restricted space between the precartilaginous regions of the radius and the ulna, and those of the metacarpals 2 and 3, but not those of the metacarpals 3 and 4. Such stage-specific and "position-specific" expressions of the AV-1 antigen in limb buds strongly suggest that the AV-1 antigen or cells containing it are involved in determination of the limb pattern formation.

Age Factors↗

PubMed1988

Generation of human myogenic cell lines by the transformation of primary culture with origin-defective SV40 DNA.

The gene transfection technique was applied to establish clonal human skeletal muscle cell lines. DNA of a replication origin-defective mutant of SV40 was transfected into a primary culture of human skeletal muscle by the DNA-calcium phosphate co-precipitation method, and myoblast-derived cells were selected from among the transformed cells and cloned. The myogenic clonal cells exhibited an enhanced growth rate and an unlimited life span, which indicated that a stable supply of a large quantity of cultured human myogenic cells without contaminating fibroblasts was possible. In addition, despite the transformation, the transformed clones retained a certain differentiation ability, that is, they could form multinucleated cells or express a muscle-specific isomer of creatine kinase. These characteristics of transformed myogenic cells should be of great value in studies on the molecular pathologies of various myopathies.

Cell Differentiation↗

PubMed1988

Transient neonatal hyperthyroidism and maternal thyroid stimulating immunoglobulins.

Serum thyroid stimulating hormone binding inhibitor immunoglobulins (TBII) and thyroid stimulating antibody (TSAb) concentrations were measured in three pregnant women with hyperthyroidism and then in their infants. The results suggested that TBII concentrations in infants in the neonatal period or from mothers during the third trimester of pregnancy showed a good correlation with the development of neonatal hyperthyroidism.

Adult↗

PubMed1988

Hypothalamic-pituitary function in growth hormone-deficient patients with pituitary stalk transection.

We compared 1.5 T magnetic resonance (MR) image findings with hypothalamic-pituitary function in 11 patients with idiopathic pituitary dwarfism, each of whom had a history of perinatal abnormalities, and 1 patient with posttraumatic pituitary dwarfism. MR imaging revealed transection of the pituitary stalk in all patients and the formation of an ectopic posterior lobe at the proximal stump in 9 patients, none of whom had polydipsia or polyuria. Three patients without an ectopic posterior lobe had diabetes insipidus. The 5 patients who had small pituitary glands (less than 2 mm in height) had hypothyroidism with low serum TSH concentrations and low serum cortisol responses to insulin-induced hypoglycemia; however, 7 patients with normal-sized pituitary glands had normal thyroid and adrenal function. The serum GH response to GHRH did not correlate with the size of the pituitary gland. The patients with small pituitary glands had delayed or prolonged serum TSH responses to TRH and impaired serum LH and FSH responses to GnRH; 4 of the patients with normal-sized pituitary glands had normal serum TSH, LH, and FSH responses. Only 2 patients had high basal serum PRL concentrations. The endocrinological data suggest that reestablishment of the hypothalamo-hypophyseal portal circulation, which cannot be seen by MR imaging, may occur. We suggest that the primary cause of idiopathic pituitary dwarfism in many patients is injury to the pituitary stalk at birth.

Adolescent↗

PubMed1988

Nocturnal urinary growth hormone excretion in children with short stature.

Nocturnal urinary growth hormone levels in children with short and normal stature were measured by a sensitive enzyme immunoassay. Urinary GH excretion during sleep correlated positively with peak plasma GH values during pharmacological (r = 0.74, P less than 0.001) and sleep (r = 0.85, P less than 0.001) tests. The amounts of urinary GH excretion during sleep differed significantly from each other in the following groups: complete GH deficiency (mean +/- SEM: 0.1 +/- 0.1 ng/m2 of body surface area; range: less than 0.1-0.4), partial GH deficiency (1.6 +/- 0.3 ng/m2; 0.2-3.1), and short stature without GH deficiency (3.7 +/- 0.6 ng/m2; 0.7-11.5). No significant difference was found between short stature without GH deficiency and normal stature (5.0 +/- 0.5 ng/m2; 2.1-10.5). Measurement of nocturnal urinary GH excretion is a simple method for screening of GH excretion and may be helpful in the differentiation of the various etiologies of short stature in children.

Adolescent↗

PubMed1987

Single central maxillary incisor and holoprosencephaly.

A holoprosencephalic child was born to a mother with a single central maxillary incisor. The infant had a median cleft lip, a flat nose with a single nostril, hypotelorism, and normal chromosomes. The head was brachycephalic and small, and computed tomography (CT) of the brain showed semilobar holoprosencephaly. The mother had mild hypotelorism but no anosmia, and her brain CT was normal. She was of normal intelligence and stature. Other relatives did not have single central maxillary incisors, hypotelorism, or oral clefts. Whether the mother's anomaly was a new mutation or had been inherited is unknown. We show the significance of a single central maxillary incisor as an indicator or potential holoprosencephaly in the next generation, even if other relatives are apparently normal.

Abnormalities, Multiple↗

PubMed1987

Clinical trial with authentic recombinant somatropin in Japan.

Recombinant somatropin, produced by recombinant DNA technology, was administered by injection in daily doses of 8 IU to six healthy young volunteers. Daily injection for 4 days did not cause any significant change in the results of physical examination, blood count or urinalysis. Non-esterified fatty acid levels increased significantly from 0.45 +/- 0.16 to 1.08 +/- 0.12 mEq/litre (mean +/- SEM) at 4 hours after the first injection (p less than 0.001). Plasma IGF-1 levels increased from 0.80 +/- 0.14 units/ml to 1.72 +/- 0.50, 3.22 +/- 1.02, 3.17 +/- 1.20 and 3.63 +/- 0.78 units/ml at 24 hours after each daily injection for 4 days (p less than 0.001). Plasma hGH reached peak levels at 3 hours after intramuscular injection of recombinant somatropin, 4 IU, and this peak value was 57.3 +/- 2.8 ng/ml. A total of 21 patients with pituitary dwarfism were also treated with recombinant somatropin for 6 months at a dose of 0.5 IU/kg/week. Their heights increased by 2.2-5.0 cm during the 6 months of treatment, which was calculated to be equivalent to 4.4-10.0 cm/year with a mean growth rate of 7.4 +/- 0.4 cm/year. Anti-hGH antibody with a titre of 10 was observed in two patients at the end of 6 months of treatment.

Adolescent↗