PubMed Health⌕ Search

Biomedical subjects

T Yasuhara

Publications and source records attributed to T Yasuhara.

At least 19 recordsLinked to original sources
PubMed1979

Amino acid composition and sequence of crinia-angiotensin, an angiotensin II-like endecapeptide from the skin of the Australian frog Crinia georgiana.

Methanol extracts of the skin of the Australian amphibian Crinia georgiana contain large amounts of crinia-angiotensin II, a new angiotensin II-like peptide. This differs sharply from the conventional octapeptide angiotensins II in having attached the tripeptide Ala-Pro-Gly- to the N-terminus, and having an Ile residue substituted for the Val residue at position 6 from the C-terminus. Small amounts of angiotensin-like peptides have been traced, by radioimmunoassay, in skin extracts of some other Crinia species.

Amino Acid Sequence↗
PubMed1979

Studies on circulating soluble immune complexes of the liver disease. 1. Inhibition assay of polyclonal rheumatoid factor binding to IgG-sepharose.

Polyclonal rheumatoid factor (pRF) was isolated from sera seropositive for RF and it was radioiodinated with lactoperoxidase method. Using the 125I-pRF and IgG-p-azobenzamidoethyl Sepharose 6B, a competitive inhibition radioassay for detecting immune complexes is described. The assay can be performed in 90 min utilizing 10 microliter of serum with good reproducibility and endogenous RF in test serum did not interfere the reaction. The test can detect complexes nearly to 8s and as low as 0.1 microgram/ml of aggregated human IgG. Decomplementation by heating test sera is unnecessary. The assay was performed at 4 degrees C but less inhibition activity was obtained when it was carried out at 24 degrees C.

Antigen-Antibody Complex↗
PubMed1979

Studies on circulating soluble immune complexes of the liver disease. 2. Serum inhibitory activity of polyclonal rheumatoid factor binding to IgG-sepharose.

Circulating immune complexes were tested in the liver disease by measuring polyclonal rheumatoid factor (pRF) inhibition activity. The test is based on the inhibition of 125I-pRF binding to IgG-p-azobenzamidoethyl Sepharose 6B. Normal levels of the test were less than 23%. The inhibition activity in sera with liver disease was found to correlate with severity of the disease, as defined by histological criteria. There were correlations of the activity with serum gamma-globulin concentration, seropositivities for rheumatoid factor and hepatitis B antigen.

Antigen-Antibody Complex↗
PubMed1976

[In vitro assay for ACTH-releasing activity using ACTH radioimmunoassay: ACTH releasing activities by various drugs (author's transl)].

Several procedures have been reported for the assay of corticotrophine-releasing factor (CRF), each having its advantages and disadvantages. This report deals with an in vitro assay of ACTH releasing activity utilizing pituitary incubation combined with ACTH radioimmunoassay. Rat half pituitary was preincubated in 2 ml Krebs Ringer bicarbonate buffer containing 0.2% glucose and 0.25 % BSA (KRBG-BSA) for 1.5 hr (45 min X 2). The medium was replaced by 1 ml KRBG-BSA and incubated for 30 min. Then the medium was again replaced by 1 ml KRBG-BSA or KRBG-BSA containing test materials and incubated for another 30 min. The amount of ACTH assayed by radioimmunoassay in the 2nd 30 min incubation was compared with in the 1st 30 min incubation and expressed as percentage. In ACTH radioimmunoassay, anti-ACTH serum was diluted to 1 : 1,500-3,000. The 125I-alpha 1-24ACTH-antibody system was not affected by lysine-vasopressin (LVP), arginine-vasopressin (AVP), rat's pituitary LH, GH and prolactin. Human 1-39ACTH was used as ACTH standard, and the dilution curve of incubation medium was paralleled with the standard curve. Repeatability of immunoassayable ACTH within-assay was 174 +/- 5.0 pg/tube (CV = 2.9%). A log dose-relationship was observed between the amounts of stalk median eminence extracts (SME ; NIAMDD) added to the incubation medium and its ACTH releasing activities. The sensitivity of this assay method was at least 0.1 SME or 10 mU of LVP and AVP. Using this method, it found that LVP, AVP, norepinephrine (100 ng/ml200 ng/ml) and 5-hydroxytryptophane (1 mug/ml) had ACTH releasing activities but LH-RH, TRH, glucagon, dopamine, phentolamine, propranolol, haloperidol, prostaglandin E1 and indomethacin did not affect the release of ACTH.

5-Hydroxytryptophan↗
PubMed1976

[Hypothalamic-hypophyseal-adrenocortical dysfunction in patients with anorexia nervosa (author's transl)].

Hypothalamic-pituitary-adrenocortical function was investigated in 14 patients with anorexia nervosa. Impaired suppression of plasma cortisol by dexamethasone was revealed. In 14 patients with anorexia nervosa, circadian rhythm of plasma cortisol, insulin tolerance test, rapid ACTH test and overnight dexamethasone suppression test were examined. Levels of plasma cortisol were higher than those in control subjects throughout the day, and normal circadian rhythm of plasma cortisol was not observed. Basal levels of plasma ACTH were within normal range. tthe response of plasma cortisol to insulin-induced hypoglycemia was lower than that in control subjects, while the response of plasma cortisol in rapid Acth test was normal. In overnight suppression tests, in which one mg dexamethasone was administered orally, 11 of 14 patients showed no suppression of plasma cortisol and 3 other patients showed incomplete suppression. Elevated levels of plasma cortisol and the absence of normal circadian rhythm in patients with anorexia nervosa and malnutrition have already been reported by other investigators, and these abnormalities were ascribed to the delayed half life of plasma cortisol due to impaired cortisol metabolism. However, according to our investigation, it is difficult to explain the failure of dexamethasone to suppress cortisol only by the delayed half life of plasma cortisol, and it is supposed that some kind of abnormal hypothalamic control is also involved.

17-Ketosteroids↗