PubMed Health⌕ Search

Biomedical subjects

M Toriumi

Publications and source records attributed to M Toriumi.

12 recordsLinked to original sources
PubMed1997

Enantioseparation of beta-blockers labelled with a chiral fluorescent reagent, R (-)-DBD-PyNCS, by reversed-phase liquid chromatography.

A fluorescent chiral tagging reagent, 4-(3-isothiocyanatopyrrolidin-1-yl)-7-(N,N-dimethylaminosulfony l)-2,1, 3-benzoxadiazole [R(-)-DBD-PyNCS], has been used for the liquid chromatographic resolution of racemic pairs of beta-blockers. The reagents reacts with beta-blockers at 65 degrees C for 90 min in aqueous acetonitrile containing 0.05% triethylamine to produce the corresponding pair of diastereomers. No racemization occurs during the tagging reaction under these conditions. From results of the time-course study of oxprenolol the reactivities of the enantiomers of beta-blockers with R(-)-DBD-PyNCS are comparable. The optimum excitation and emission wavelengths of the resulting derivatives were ca. 460 and 550 nm, respectively. The derivatives of beta-blockers were efficiently resolved by a reversed-phase column with water-acetonitrile containing 0.1% trifluoroacetic acid as the eluent. The resolution (Rs) values of the diastereomers derived from 10 beta-blockers were in the range of 1.54-4.80. The Rs value for timolol was 0.643. The detection limits (signal-to-noise ratio of 2) were one or two orders of magnitude lower with beta-blockers having the iso-propylamino structure (15-300 fmol) than with those having the tert-butylamino structure (1.25-8.00 pmol). The proposed procedure was applied to the determination of R(+)- and S(-)-propranolol in rat plasma and saliva after oral administration of R(+)-propranolol hydrochloride or S(-)-propranolol hydrochloride.

Administration, Oral↗
PubMed1997

[CRH-test].

Explore the source record for details and available documents.

ACTH Syndrome, Ectopic↗
PubMed1997

[ACTH test].

Explore the source record for details and available documents.

Addison Disease↗
PubMed1997

[Metyrapone test].

Explore the source record for details and available documents.

ACTH Syndrome, Ectopic↗
PubMed1997

[Disorders of gonadal function in hypothalamic-pituitary diseases].

Hypothalmic-pituitary-gonadal hormones are regulated by number of factors including GnRH, LH and FSH, and gonadal hormones. They are regulated also by pituitary prolactin, activin and inhibin. Hypogonadism is divided into primary and secondary hypogonadism. Secondary hypogonadism is caused by various lesions involving either the hypothalmus or the pituitary. In this paper, etiology, diagnosis and treatment of the secondary hypogonadism are described. The most frequent causes of hypothamic hypogonadism are hypothalamic tumors, such as germinoma. As the pituitary hypogonadism, pituitary tumors, and Sheehan's syndrome are most common disorders. Diagnosis of the secondary hypogonadism is made based on the diagnostic criteria established by The Research Group of the Japanese Ministry of Health and Welfare. The criteria includes signs and symptoms in addition to laboratory examinations such as measurement of serum gonadotropin, sex steroid and LH-RH test. First choice of the treatment of hyothalmic hypogondism is continuous pulsatile injection of synthetic LH-RH. In the pituitary hypogonadism, hCG, hMG, estrogen and testosterone or the combination of these are applied depending upon the age and other factors of the patients.

Adolescent↗
PubMed1996

Grain Growth Rates of MgSiO3 Perovskite and Periclase Under Lower Mantle Conditions

The grain growth rates of MgSiO3 perovskite and periclase in aggregates have been determined at 25 gigapascals and 1573 to 2173 kelvin. The average grain size (G) was fitted to the rate equation, and the grain growth rates of perovskite and periclase were G10.6 = 1 x 10(-57.4) t exp(-320.8/RT) and G10.8 = 1 x 10(-62.3) t exp(-247.0/RT), respectively, where t is the time, R is the gas constant, and T is the absolute temperature. These growth rates provide insight into the mechanism for grain growth in minerals relevant to the Earth's lower mantle that will ultimately help define the rheology of the lower mantle.

Journal Article↗
PubMed1996

[Endocrine disorders associated with impaired glucose tolerance].

Endocrine disorders associated with diabetes mellitus are described. When blood glucose control deteriorates, observed endocrine abnormalities are as follows. 1) Blood GH levels increase. This elevation is small but enough to disturb insulin secretion and glucose metabolism. Plama insulin-like growth factor-1 levels decrease in spite of their strong relation with diabetic retinopathy. 2) Blood thyroid hormones show the similarity with low T3 syndrome. 3) Hyporeninemic hypoaldosteronism occurs especially with patients who have hypertension or moderate diabetic complications. 4) Plasma pancreatic glucagon levels are elevated. Amino acids induce hypersecretion but hypoglycemia fails to response normally. Glucose administration shows impaired inhibition or paradoxical hypersecretion. 5) Other plasma levels of pancreatic hormones such as gastrin, secretin, motilin and somatostatin are usually elevated.

Diabetes Complications↗