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Biomedical subjects

N Hirose

Publications and source records attributed to N Hirose.

At least 109 records · Page 6Linked to original sources
PubMed1984

Plasma growth hormone (GH) response to GH-releasing factor in normal children with short stature and patients with pituitary dwarfism.

Synthetic human pancreatic GRF (hpGRF-44) was administered as an iv bolus to 28 normal children with short stature and 27 patients with GH deficiency. After a dose of 1 or 2 micrograms hpGRF-44/kg BW, mean plasma GH levels peaked at 15 and 30 min, respectively, with corresponding values of 30.1 +/- 4.7 and 33.2 +/- 3.7 ( +/- SE) ng/ml in normal but short children. The overall plasma GH response was greater than that of other GH stimulation tests such as insulin-induced hypoglycemia, glucagon-propranolol or L-dopa administration. Plasma LH, FSH, TSH, PRL, and cortisol levels were not altered by hpGRF-44 injection. Sixteen of 27 patients with GH deficiency did not respond to a 2 micrograms/kg BW hpGRF-44. However, plasma GH increases to greater than 5 ng/ml occurred in the remaining 11 patients. Their GH levels reached peaks between 15 and 90 min, with values ranging between 5.8 and 17.8 ng/ml. Two of these responding patients were infused iv with hpGRF-44 at 2.5 micrograms/min for 90 min after receiving an iv bolus injection of 2 micrograms/kg BW. Their plasma GH levels increased and remained near peak values throughout the infusion period. However, no increase in plasma GH levels occurred after a second bolus injection of hpGRF-44 given at the end of the infusion. These results suggest that hpGRF-44 is useful for the diagnosis of GH deficiency in individuals with short stature and that some patients with GH deficiency, diagnosed on the basis of established tests, have GH responses to hpGRF-44.

Adolescent↗
PubMed1984

Plasma growth hormone secretion during constant growth hormone-releasing factor infusion.

Synthetic human pancreatic growth hormone-releasing factor (hpGRF-44) was infused intravenously at a constant rate of 2.5 micrograms/min for 180 minutes in 3 normal boys of short stature. Plasma GH levels reached a peak at 60-120 min with a mean value (+/- SEM) of 69.1 +/- 14.3 ng/ml, and then, declined gradually in spite of continuous hpGRF-44 infusion up to 180 minutes. Similarly, constant infusion of hpGRF-44 at a rate of 2.5 micrograms/min in 5 normal but short boys for 90 minutes, together with an iv bolus injection of hpGRF-44 (2 micrograms/kg) administered at 0 and 90 minutes, elicited a prompt rise in plasma GH 15-30 minutes after the first bolus but no significant elevation of GH was observed after the second bolus. In contrast, when two iv bolus injections of hpGRF-44 (2 micrograms/kg) were given in 4 normal boys with short stature at 0 and 90 minutes, respectively, significant elevation of plasma GH was found after each bolus. These results suggest that under constant infusion of GRF the pituitary experiences a down-regulation after the initial peak of GH response, possibly due to desensitization to GRF.

Adolescent↗
PubMed1984

Plasma growth hormone responses to repetitive administrations of growth hormone releasing factor in patients with pituitary dwarfism.

Plasma growth hormone (GH) responses to the repetitive administrations of synthetic human pancreatic growth hormone releasing factor (hpGRF-44) were studied in 15 patients with GH deficiency (11 diagnosed as idiopathic and 4 diagnosed as secondary to hypothalamo-pituitary tumor). hpGRF-44 was administered by single iv bolus (2 micrograms/kg), repetitive im (100 micrograms, twice a day), and/or repetitive iv infusion (2.5 micrograms/min for 90 min, once a day) for three to six consecutive days. Three of the eleven idiopathic GH deficient patients had plasma GH responses to both single iv bolus injection and repetitive administrations by im, or iv infusion of hpGRF. In four of the remaining eight, who had not had peak plasma GH levels above 5 ng/ml to a single iv bolus of the peptide, repetitive administrations of hpGRF-44 by im injection and/or iv infusion induced GH responses to the peptide. In the four patients with secondary GH deficiency, three had plasma GH response to hpGRF administration but one patient, who had indications of pituitary disorder, did not show any plasma GH response to either single iv injection or repetitive administrations of hpGRF-44. These data show that repetitive administrations of hpGRF-44 can induce plasma GH responses in some GH deficient patients who do not respond to a single iv bolus of the peptide.

Adolescent↗
PubMed1983

The occurrence of three different proteoglycan species in chick embryo cartilage. Isolation and characterization of a second proteoglycan (PG-Lb) and its precursor form.

Three different molecular species of proteoglycan (designated PG-H, PG-Lb, and PG-Lt) have been isolated from chick embryo epiphyseal cartilage. PG-H is a major proteoglycan of the tissue and identical, or nearly identical, with so-called cartilage-characteristic proteoglycan previously described in mammalian and avian cartilages. The third proteoglycan, PG-Lt, differs from the other two in containing disulfide-bonded collagenous polypeptides (Noro, A., Kimata, K., Oike, Y., Shinomura, T., Maeda, N., Yano, S., Takahashi, N., and Suzuki, S. (1983) J. Biol. Chem. 258, 9323-9331). The second proteoglycan, PG-Lb, consists of a core protein with Mr congruent to 52,000 dermatan sulfate copolymer chains with glucuronic acid/iduronic acid residues. Upon chondroitinase ABC digestion, the proteoglycan yields a protein-enriched core fraction of Mr congruent to 43,000. Its amino acid composition, tryptic peptide profile, and immunochemical properties indicate that PG-Lb is distinctly different from PG-H and PG-Lt in core protein structure. PG-Lb shows no specific binding with hyaluronic acid. Pulse-chase experiments with [3H]serine indicate that PG-Lb is first synthesized as a precursor form (pro-PG-Lb) that can be distinguished from PG-Lb by the production of a core molecule of Mr congruent to 52,000 after chondroitinase ABC digestion. This core molecule is labeled when [2-3H]mannose is used as a precursor, suggesting that it contains a glycoprotein type oligosaccharide. Since the core molecule from pro-PG-Lb is significantly larger in molecular weight than that from PG-Lb, the conversion of pro-PG-Lb to PG-Lb should involve scission of the polypeptide or possibly removal of mannose-containing oligosaccharide chain.

Amino Acids↗
PubMed1981

Serum lipid and lipoprotein profiles in patients with xanthomas: a correlative study on xanthoma and atherosclerosis (I).

In an attempt to correlate xanthomas with atherosclerosis, the characteristics of serum lipid and lipoprotein profiles are explored in xanthoma patients. Xanthomas are classified into 5 subtypes: xanthelasma, planar xanthoma, papulo-eruptive xanthoma, tuberous xanthoma and tendon xanthoma. The clinical characteristics of xanthoma patients are summarized in the following. 1) Xanthelasma in 2 different types: one normolipemic and the other hyperlipidemic; of 30 xanthelasma patients, 5 were normolipemic, one of them had low HDL-cholesterol. 2) Tuberous and tendon xanthomas were all hypercholesterolemic, with serum cholesterol above 300 mg/dl and LDL-cholesterol above 255 mg/dl, while HDL-cholesterol was within normal range. 3) The xanthoma patients were generally not obese. 4) Their laboratory findings often showed such abnormalities as elevated levels in serum fibrinogen, LDH, CPK and uric acid. The resemblance of the clinical characteristics between xanthomas and atherosclerotic vascular disease, e.g., myocardial infarction, was striking. If the causation of their common tissue alterations by lipid accumulation is pathologically and biochemically defined, the correlation between those 2 kinds of disease can be established.

Adult↗
PubMed1981

Pharmacokinetic and biopharmaceutical studies on azelastine hydrochloride in beagle dogs by quantitative selected-ion monitoring.

A quantitative selected-ion monitoring method for the determination of plasma concentrations of the new potent antiallergic agent, 4-(p-chlorobenzyl)-2-(hexahydro-1-methyl-1H-azepin-4-yl)-1-(2H)-phthalazinone hydrochloride (azelastine hydrochloride, A 5610), using N-methyl deuterium labelled azelastine as the internal standard, has been developed. This specific method has a lower limit of sensitivity of about 0.5 ng/ml plasma. The utility of this method was demonstrated by pharmacokinetic studies in the beagle dog after a single oral 20 mg dose as aqueous solution or as sugar-coated tablets, and after a single 10 mg i.v. dose. Plasma concentration-time curves following i.v. dose were satisfactorily described by a bi-exponential equation, and the mean values of half-lives (t 1/2) for the distribution and elimination phases were 17.5 +/- 5.0 min and 160 +/- 14 min, respectively. From the comparison of the areas under the curves after the p.o. dose of aqueous solution and tablet to that after i.v. dose, the absolute availabilities were estimated to be 16.6 +/- 2.5% and 19.6 +/- 0.4%, respectively. These low availabilities could be explained on the basis of a first-pass effect. From the analysis according to the Loo-Riegelman method, the absorption rate was revealed to be described by a first-order process. The absorption half-lives were 48.1 +/- 10.2 min for the solution and 58.4 +/- 21.8 min for the tablet. The lag times before onset of absorption were 18.2 +/- 2.1 min and 40.9 +/- 10.8 min, respectively. This seemed to be due to the difference in gastric emptying time or disintegration time of the tablets in the gastro-intestinal tract.

Animals↗
PubMed1979

New bronchodilators. Synthesis and bronchodilating activity of some 3-(alkoxymethyl)-alpha-(N-substituted aminomethyl)-4-hydroxybenzyl alcohols.

A series of 3-(alkoxymethyl)-alpha-(N-substituted aminomethyl)-4-hydroxybenzyl alcohols was synthesized as potential bronchodilators. The ability to prevent effects against histamine-induced bronchoconstriction in guinea pigs was studied to determine their bronchodilating activity. Introduction of a methoxymethyl group in place of the m-hydroxyl group of beta-adrenergic catecholamines afforded compounds especially effective in delaying histamine-induced bronchoconstriction in guinea pigs. Appropriate N-substitution also enhanced the potency of these catecholamine analogues. 4-Hydroxy-3-(methoxymethyl)-alpha-[N-[4-(methoxymethyl)-alpha-methylphenyl]aminoethyl]benzyl alcohol hemifumarate (3r) was the most potent compound in this series.

Airway Resistance↗
PubMed1977

Polygraphic study of periodic breathing and hypersomnolence in a patient with severe hypothyroidism.

A 67-year-old woman with primary hypothyroidism, who had Pickwickian syndrome as well, was studied electrophysiologically. A polygraphic study with simultaneous recordings of electroencephalography, actograms of the abdominal walls, the mentum and the anterior neck, and electromyogram of the intercostal muscles revealed a cyclic appearance of apnea in the sleep phase and gasping preceding arousal, which, together with macroglossia and sleep in the sitting position, suggested a cyclic obstruction of the upper airway. The obstruction appeared responsible for both alveolar hypoventilation and disturbance of consciousness.

Aged↗