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Biomedical subjects

N Matsuo

Publications and source records attributed to N Matsuo.

At least 217 records · Page 12Linked to original sources
PubMed1992

Expression pattern of the activin receptor type IIA gene during differentiation of chick neural tissues, muscle and skin.

To elucidate target cells of activins during embryogenesis we isolated cDNAs of chick activin receptor type II (cActR-II) and studied expression patterns of the cActR-II gene by in situ hybridization. Transcripts of cActR-II were observed in neuroectoderm developing to spinal cord, brain and eyes, in surface ectoderm differentiating to epidermis, and in myotomes differentiating to muscles. The expression patterns of cActR-II suggest that activin and its receptor are involved in differentiation of chick neural tissues, muscle and skin after inducing the dorsal mesoderm.

Activin Receptors↗
PubMed1992

A rapid and simple assay method for UDP-glucose:ceramide glucosyltransferase.

We have developed a simple rapid method for measuring UDP-glucose:ceramide glucosyltransferase; the method utilizes ceramide immobilized on the surface of silica gel and [14C]UDP-glucose as substrate. The reaction product, [14C]glucosylceramide, formed on the surface of the silica gel was easily separated from free [14C]UDP-glucose, either by centrifugation or by filtration. The reliability of this solid phase method was evaluated by using rat brain membrane fraction as an enzyme source. This enzyme had an optimal pH of 6.4-6.5 and required Mn2+, Mg2+ in the presence of 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS). Apparent Km values of 8.7 microM for UDP-glucose and 292 microM for ceramide were determined using the new method. Under the optimal conditions, the solid phase method yielded 2-5-times more product than did the method using micellar system. Moreover, the reaction was highly quantitative in its enzyme dose-activity relationship.

Animals↗
PubMed1992

Changes in brain ECF amino acids in rats with experimentally induced hyperammonemia.

Using microdialysis, we studied brain extracellular fluid (ECF) amino acid metabolism in rats with experimentally induced hyperammonemia and regional elevation of brain ECF ammonia levels. The total brain ECF amino acid level was increased by an elevation of the blood ammonia level. Hyperammonemia elevated brain ECF aromatic amino acids and reduced arterial blood branched chain amino acids. When rats with hyperammonemia were intravenously administered norleucine, the brain ECF norleucine level rose markedly, suggesting increased permeability of the blood-brain barrier. When rats with hyperammonemia were infused with a branched chain amino acid-rich preparation, the elevated brain ECF aromatic amino acids level was not suppressed. Following local intracerebral ammonia infusion, only glutamate levels showed a marked elevation. These results suggest that impairment of the blood-brain barrier related to hyperammonemia increases the inflow of low molecular weight substances including amino acids. Furthermore, the ammonia-induced increase of glutamate in the cerebral ECF suggests that high ammonia levels may increase the excitability of the brain. Thus, ammonia may serve as a key factor in the onset of hepatic encephalopathy.

Amino Acids↗
PubMed1992

Fructose and glucagon loading in siblings with fructose-1,6-diphosphatase deficiency in fed state.

Hypoglycaemia induced by fructose administration is one of the diagnostic clues to fructose-1,6-diphosphatase (FDPase) deficiency (McKusick 229700). However, the pathological mechanism of this reactive hypoglycaemia is not fully known. This paper describes two siblings with FDPase deficiency, diagnosed enzymatically in leukocytes, who failed to correct reactive hypoglycaemia after glucagon administration even in the fed state, supporting a possibility that disturbed hepatic phosphorylase activity may be a main cause of reactive hypoglycaemia.

Blood Glucose↗
PubMed1992

The association of hypopituitarism with small pituitary, invisible pituitary stalk, type 1 Arnold-Chiari malformation, and syringomyelia in seven patients born in breech position: a further proof of birth injury theory on the pathogenesis of "idiopathic hypopituitarism".

We report seven cases of hypopituitarism all having a history of breech delivery, asphyxia at birth, and syringomyelia. A small pituitary gland was found on MRI or CT in six cases, invisible pituitary stalk on MRI in five cases, and type 1 Arnold-Chiari malformation in six cases. A constellation of these abnormalities are best explained by traction of brain and spinal cord of the subjects exerted during breech delivery and further support the primary role of birth trauma in the genesis of "idiopathic hypopituitarism".

Adolescent↗
PubMed1992

Detection of human papillomavirus genome and analysis of expression of c-myc and Ha-ras oncogenes in invasive cervical carcinomas.

Invasive carcinomas of the uterine cervix of 38 patients were examined for the presence of human papillomavirus (HPV) genomes and for the state of the c-myc and Ha-ras oncogenes. A combination of Southern blot hybridization and polymerase chain reaction revealed the presence of the genome of HPV type 16 in 17 tumors (45%), that of HPV type 18 in 3 tumors (8%), and that of unknown types in 16 others (42%), while no viral DNA sequences were detected in 2 tumors. Of the 38 tumors, c-myc amplification was found in only 1 tumor, while there was no Ha-ras amplification. Overexpression of the c-myc gene was observed in 15 (44%) of the 34 tumors analyzed, while there was no overexpression of Ha-ras. Of the 23 squamous cell carcinomas analyzed, relapse-free rates at 24 months were 55% in tumors with c-myc overexpression and 100% in case of tumors with no c-myc overexpression, respectively. The results suggest the possibility that activation of the c-myc oncogene is involved in tumor progression.

Base Sequence↗
PubMed1992

Treatment of Kawasaki disease using the intravenous aspirin anti-inflammatory effect of salicylate.

Serum salicylate concentrations were measured in 60 patients with acute phase Kawasaki disease (KD), who were treated with intravenous aspirin (IVASP), to evaluate its anti-inflammatory effect in the treatment of KD. Patients with serum salicylate concentrations > or = 150 micrograms/ml showed shorter durations of fever (7.1 +/- 2.0 vs 10.4 +/- 6.6 days; P < 0.05), shorter durations of positive serum C-reactive protein (14.6 +/- 4.5 vs 22.3 +/- 10.6 days; P < 0.01) and lower incidences of coronary arterial involvements (0/10 vs 6/24; P < 0.05) than did patients with serum salicylate concentrations < 150 micrograms/ml. Significant linear correlations were recognized between daily IVASP dosage and serum salicylate concentrations (r = 0.73; P < 0.01), and between serum salicylate concentrations and serum free salicylate concentrations (r = 0.82; P < 0.01). These correlations did not differ between the presence and absence of coronary arterial involvements. Based on these findings we concluded that a beneficial anti-inflammatory effect in the treatment of KD is achieved when the serum salicylate concentration is > or = 150 micrograms/ml, and that such concentrations could be achieved by increasing the daily IVASP dosage to 100 mg/kg per day or more.

Acute Disease↗
PubMed1992

Sex reversal in a child with a 46,X,Yp+ karyotype: support for the existence of a gene(s), located in distal Xp, involved in testis formation.

We report on a sex reversed Japanese child with a 46,X,Yp+ karyotype, minor dysmorphic features, and no testicular development. The Yp+ chromosome was derived by translocation of an Xp fragment (Xp21-Xp22.3) to Yp11.3. This has resulted in deletion of distal part of the Y chromosome pseudoautosomal region (DXYS15-telomere) and duplication of the X specific region (DXS84-PABX) and proximal part of the pseudoautosomal region (MIC2-DXYS17). No deletion of the Y specific region was detected nor was any mutation found in SRY. Cytogenetic analysis suggests that the proximal part of the Xp fragment is the most distal part of the short arm of the Yp+ chromosome (Xp21----Xp 22.3::Yp11.3----Yqter). No chromosomal mosaicism was detected. These results are similar to previous reports of sex reversal in four subjects with a 46,Y,Xp+ karyotype. We conclude that the sex reversal is a direct, or indirect, consequence of having two active copies of the distal part of Xp and may indicate the presence of a gene(s) which acts in the testis determination or differentiation pathway.

Base Sequence↗
PubMed1992

Comparison of adult height between patients with XX and XY gonadal dysgenesis: support for a Y specific growth gene(s).

Adult height was compared between published cases of patients with XX gonadal dysgenesis (XXGD) and those with XY gonadal dysgenesis (XYGD). The mean adult height of XYGD patients (171.0 cm (SD 7.8), n = 27) was significantly greater than that of XXGD patients (164.4 cm (7.7), n = 27) (p less than 0.01). This finding supports the existence of a Y specific growth gene(s) which promotes statural growth independently of the effects of gonadal sex steroids.

Adult↗
PubMed1992

Chromosomal localisation of a pseudoautosomal growth gene(s).

Although recent molecular studies in patients with sex chromosome aberrations are consistent with a growth gene(s) being present in the pseudoautosomal region (PAR), the precise location has not been determined. In this report, we describe a Japanese boy and his mother with an interstitial deletion in Xp22.3 and review the correlation between genotype and stature in six cases of partial monosomy of the PAR. The results indicate that the region from DXYS20 to DXYS15 is the critical region for the putative growth gene(s).

Abnormalities, Multiple↗
PubMed1992

An acute mercuric mercury poisoning: chemical speciation of hair mercury shows a peak of inorganic mercury value.

A woman ingested a dose of sublimate (approximately 0.9 g) in an attempted suicide. She survived and recovered in response to a combination of therapies including chelate (BAL) therapy, plasma exchange, haemodialysis and peritoneal dialysis. Serum inorganic mercury concentration, urinary inorganic mercury excretion and hair inorganic and organic mercury and selenium concentrations, along the length from the scalp to the distal part, were measured. Longitudinal analysis of hair, revealed a peak in inorganic mercury corresponding to the time of mercury ingestion. Organic mercury and selenium in the hair had different patterns of longitudinal variation from that of inorganic mercury. The biological half-life (23.5 d) of serum inorganic mercury levels was in good agreement with values previously reported in the literature.

Adult↗
PubMed1992

'Hit and run' oncogenesis by human papillomavirus type 18 DNA.

Transfection of an immortalized cell line (AE), derived from Syrian hamster embryo cells, with human papillomavirus type 18 (HPV 18) DNA induced morphological transformation and these transformed cells were tumorigenic in nude mice. Southern blot analysis revealed that the transfected viral DNA was retained in all the cell lines tested, however, all these transformed cells contained only less than one copy per cell of viral genome. Eleven cloned cell lines were established from a tumor cell line obtained after explantation of a tumor into a nude mouse. Two lines revealed no viral sequences by both Southern blot hybridization and polymerase chain reaction, whereas the nine others contained the remaining viral sequences. These results are highly suggestive of a 'hit and run' oncogenesis by this virus.

Animals↗
PubMed1992

[Usefulness of segmental Lp-TAE using lipiodol mixed with anticancer agent for inoperable hepatocellular carcinoma].

To determine the effect of appraising subsegmental or segmental transarterial embolization with Lipiodol mixed with anticancer drugs followed by gelatin particles (Segmental Lp-TAE) on inoperable hepatocellular carcinoma, we examined CT patterns and therapeutic results in 57 patients after Segmental Lp-TAE. Fifty-six tumors including 47 tumors less than 5 cm in size were the nodular type and 1 tumor was the massive type. The mean tumor size was 3.6 cm and the mean amount of Lipiodol was 4.4 ml. Portal veins in the embolized segment were highly visualized by injected Lipiodol on plain film immediately after Segmental Lp-TAE. On the follow-up CT, the size of the tumor with dense Lipiodol accumulation were reduced in all cases, and atrophy of the embolized segment was recognized. Forty-four of the 57 patients are alive, with the longest surviving patient still alive at 4 years and 5 months. Seventeen patients have survived for more than 2 years (direct crude survival rate: 65.0%), with the cumulative survival rates 93.2% at 1 year, 71.6% at 2 years. No recurrence was recognized in 33 of the 41 patients (80.0%) that were followed up for more than 1 year after Segmental Lp-TAE is a useful therapeutic method for hepatocellular carcinoma.

Aged↗
PubMed1992

[A caruncular oxyphilic adenoma with an appearance of apocrine type secretion].

The histopathological and cytological findings of a caruncular oxyphilic adenoma (oncocytoma) in a 85 year-old male is described. The columnar or polygonal tumor cells contained numerous eosinophilic fine granules (mitochondria). They showed papillary proliferation and cyst formation. Electron microscopically, some tumor cells contained amorphous cytoplasm and small numbers of mitochondria in their apical snout, and secreted the contents in the extracellular spaces. It seemed that the tumor cells originated from the ductal epithelia in the caruncle and microscopically some cells simulated apocrine type secretion.

Adenoma↗
PubMed1992

Short stature in a girl with a terminal Xp deletion distal to DXYS15: localisation of a growth gene(s) in the pseudoautosomal region.

This report describes a Japanese girl with short stature and a rearranged X chromosome. Her height remained below the 3rd centile growth curve for Japanese girls, and her predicted adult height (148.5 cm) was below her target height (163 cm) and target range (155 to 171 cm). Cytogenetic studies showed that the rearranged X chromosome was formed by a breakage at q26 and a transfer of the Xq fragment onto the tip of Xp. The abnormal X was always late replicating. No mosaicism was detected. Molecular analysis showed an Xp terminal deletion distal to DXYS15. Biochemical and radiological studies for short stature disclosed no abnormality. On the basis of height analysis of previous reports and a genotype-phenotype correlation of this patient, we propose that a growth gene(s) is present in the distal part of the pseudoautosomal region.

Blotting, Southern↗
PubMed1991

Molecular study of the Prader-Willi syndrome: deletion, RFLP, and phenotype analyses of 50 patients.

Deletion and RFLP studies with 5 cloned DNA markers localized at 15q11.2 were performed in 50 patients with the Prader-Willi syndrome (PWS). A one-copy density (deletion) for at least one of 4 loci, D15S9, D15S11, D15S10, D15S12, was detected in 32 (64%) of the 50 patients; deletions of each of the 4 loci were found in 29, 30, 29, and 28 patients, respectively. Three patients showed 4 or more copy density for D15S12 locus, in addition to deletions. The remaining 18 patients showed two-copy densities for each of the 4 loci. A common site of rearrangements among our 32 patients as well as the reported patients seemed to be confined to a segment between D15S9 and D15S11, suggesting the putative PWS gene locus in this segment. Of 6 patients who have cytologic deletions but did not show any molecular deletions, 3 have normal size of hands and feet, and 4 have normally pigmented skin and hair. The normal pigmentation was also observed in 3 patients who had small molecular deletions in the examined 5-locus segment. These observations may support the conception of contiguous gene syndrome. RFLP analysis demonstrated maternal uniparental isodisomy of chromosomes 15 in both a patient with 45,t(15q;15q) and a karyotypically normal patient. Based on the results of the present study, a new model is proposed to explain the occurrence of PWS with a variety of chromosome abnormalities, including partial monosomy, disomy, trisomy, and/or tetrasomy for 15q11.2. The normal development may require an even or more "number ratio" of paternally derived allele(s) to maternally derived allele(s) of the gene(s) localized at 15q11.2, and a disturbance of the ratio would lead to the PWS phenotype.

Adolescent↗