Biomedical subjects

S Tsubokura

Publications and source records attributed to S Tsubokura.

4 recordsLinked to original sources

PubMed1991

Localization of prostaglandin endoperoxide synthase in neurons and glia in monkey brain.

The localization of prostaglandin endoperoxide synthase in monkey brain was investigated by the immunoperoxidase method using the monoclonal antibody (PES-7) raised against the enzyme purified from bovine seminal vesicle. The frozen sections with 30-microns thickness were employed after the brain was fixed with perfusion of 2% paraformaldehyde in phosphate-buffered saline. The immunoreactivity was most intense in the neurons of cerebral cortex and hippocampus, and was moderate in the neurons of caudate nucleus, putamen, globus pallidus and amygdala, while it was relatively weak in glial cells in the whole brain regions including the white matter. The majority of neurons showed the immunoreactivity in the somata and proximal dendrites, but exceptionally in the pyramidal cells of the hippocampus, positive staining was also observed in the apical dendrites. In the cerebellum, the immunoreactivity in both neurons and glia was rather faint as compared with that in other regions. Positive staining was not significantly observed in the vasculatures and arachnoid membranes. These findings indicate that most of neuronal and glial cells in monkey brain contain the enzyme of the rate-limiting and initial step of the biosynthesis of prostaglandins which regulate a variety of neural functions.

Animals↗

PubMed1988

Decrease in tetrahydrobiopterin content and neurotransmitter amine biosynthesis in rat brain by an inhibitor of guanosine triphosphate cyclohydrolase.

To investigate the regulatory role of tetrahydrobiopterin in neurotransmitter amine biosynthesis, 2,4-diamino-6-hydroxypyrimidine, a potent inhibitor of guanosine triphosphate cyclohydrolase which is a rate-limiting enzyme of tetrahydrobiopterin biosynthesis, was administered intraperitoneally to weanling rats. Four h after 4 injections at 4-h intervals, the biopterin contents in plasma and liver were reduced to the level of 9 and 3.5%, respectively, of those in the control group injected with saline; while the contents in the whole brain, neocortex + striatum, diencephalon, and brainstem were 34, 50, 33 and 28%, respectively, of the control level. When in vivo tyrosine and tryptophan hydroxylase activities were measured over a 30-min period after the inhibition of aromatic amino acid decarboxylase, the accumulation of dihydroxyphenylalanine was reduced to 74, 77, 67 and 69% of the control in the whole brain, neocortex + striatum, diencephalon, and brainstem, respectively; and the accumulation of 5-hydroxytryptophan, to 71, 74, 66 and 65% of the control, respectively. On the other hand, 5-hydroxytryptamine and 5-hydroxyindole acetic acid contents were not altered in any brain regions, although norepinephrine and dopamine contents were reduced to approximately 70% of the control in the brainstem and the contents of dopamine metabolites were significantly decreased in the diencephalon and brainstem. Plasma phenylalanine level was significantly elevated, while the plasma tyrosine level was reduced, compared with the control level of these amino acids. These results indicate that the drug-treated rats could be an animal model for tetrahydrobiopterin-deficient disease involving neurological disorder.

5-Hydroxytryptophan↗

PubMed1987

[Hypergonadotropic ovarian failure in three patients with pituitary hyperplasia].

Three patients with ovulatory disturbances associated with increased production of gonadotropins and normal excretion of estrogen were endocrinologically examined. Patient A was 25 years old and had irregular menstruation of 13 years' duration. Patients B and C were 32 and 36 years old, the former with secondary amenorrhea of 19 years' duration and the latter with one of 2 months. Endocrinological analyses revealed a markedly increased plasma concentration of both LH (greater than 117 mIU/ml) and FSH (greater than 113 mIU/ml) in all three patients. The plasma concentration of estradiol was over 56 pg/ml in A and C before medication, and in the other patient (case B) the plasma estradiol level rose to 53 pg/ml after the administration of clomiphene. There was excessive LH and FSH response in the LH-RH stimulation test. Episodic gonadotropin secretions were observed and two weeks' administration of estrogen plasma concentrations of LH and FSH were suppressed. Computerized tomography revealed a high density area about 9-11 mm in diameter in the sella turcica of all three patients. Patient A underwent surgery via the transsphenoidal approach. Histology shows pituitary hyperplasia. After operation, the elevated LH and FSH concentration decreased to below 30 mIU/ml and the plasma concentration of estradiol and progesterone was increased to 260 pg/ml and 2 ng/ml, respectively.

Adult↗

PubMed1982

[Clinical evaluation of piperacillin in the field of obstetrics and gynecology].

We administered piperacillin (PIPC), a semisynthetic penicillin antibiotic, to 11 patients with obstetrical and gynecological infections and obtained the following results. 1. PIPC was administered at a dose of 1 or 2 g by intravenous bolus injection or dripping infusion 1 or 2 times a day for a period of 3 approximately 8 days. The clinical effect was excellent in 5 cases and good in 6 cases and all the cases showed good effectiveness. These included good in 1 case of adnexitis, excellent in 3 cases and good in 1 case of intrauterine infections, excellent in 2 cases and good in 2 cases of pelvic inflammatory diseases and good in 2 cases of bartholinitis. Bacteriological findings indicated that S. faecalis, Staphylococcus, E. coli, K. pneumoniae, P. magnus, etc. isolated in 6 cases were eradicated after the administration of this drug. 2. Neither side effects nor abnormalities in laboratory findings caused by this drug were observed. 3. Based on these results PIPC should be considered a very safe and useful drug for treating obstetrical and gynecological infections.

Adult↗