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Biomedical subjects

I Oshima

Publications and source records attributed to I Oshima.

82 records · Page 5Linked to original sources
PubMed1975

Radioimmunoassay for luteinizing hormone releasing hormone in plasma.

A sensitive and specific double antibody radioimmunoassay has been developed capable of measuring LH-RH in extracted human plasma. Thyrotropin releasing hormone, lysine vasopressin and most of LH-RH analogues did not appear to affect the assay. Hypothalamic extract and some of the LH-RH analogues produced displacement curves which were parallel to that obtained with the synthetic LH-RH. Sensitivity of the radioimmunoassay was about 3 pg per assay tube. The coefficient of variation of intraassay was 6.4%, while that of interassay was 9.6%. Exogenous LH-RH could be quantitatively extracted by acidic ethanol when varying amounts of synthetic LH-RH were added to plasma. Immunoreactivity of LH-RH was preserved in plasma until 2 hr in the cold and gradually reduced thereafter. The plasma levels in LH-RH were 20 pg/ml or less in normal adults and not detectable in children. The aged males over 60 yr and postmenopausal women showed a tendency to have higher levels of plasma LH-RH. Plasma LH-RH level was significantly higher in midcycle than in follicular and luteal stages. The disappearance rate of LH-RH from the circulation after intravenous injection could be represented as half times of 4-6 min. Between 0.2-0.4% of the injected dose was excreted into urine within 1 hr. These results indicate that the determination of LH-RH might be a useful tool for elucidating hypothalamic-pituitary-gonad interactions.

Adolescent↗
PubMed1975

Radioimmunoassay of thyrotropin releasing hormone in plasma and urine.

A sensitive and specific radioimmunoassay has been developed capable of measuring thyrotropin releasing hormone (TRH) in extracted human plasma and urine. All of three TRH analogues tested had little cross-reactivity to antibody. Luteinizing hormone releasing hormone, lysine vasopressin, rat growth hormone and bovine albumin were without effect, but rat hypothalamic extract produced a displacement curve which was parallel to that obtained with the synthetic TRH. Sensitivity of the radioimmunoassay was 4 pg per tube with intraassay coefficient of variation of 6.2-9.7%. Synthetic TRH could be quantitatively extracted by methanol when added to human plasma in concentration of 25, 50 and 100 pg/ml. TRH immunoreactivity was rapidly reduced in plasma at 20 degrees C than at 0 degrees C, but addition of peptidase inhibitors, FOY-007 and BAL, prevented the inactivation of TRH for 3 hr at 0 degrees C. The TRH in urine was more stable at 0 degrees C than 20 degrees C, and recovered 75 +/- 4.6% hr after being added. The plasma levels of TRH were 19 pg/ml or less in normal adults and no sex difference was observed. The rate of disappearance of TRH administered i.v. from the blood could be represented as half-times of 4-12 min. Between 5.3-12.3% of the injected dose was excreted into urine within 1 hr as an immunoreactive TRH. These results indicate the usefulness of TRH radioimmunoassay for clinical investigation.

Adolescent↗
PubMedDate not supplied

No relationship between schizophrenic birth and influenza epidemics in Japan.

The finding that influenza epidemics are associated with an increased risk of adult schizophrenia has been controversial. Data was obtained from Japan's governmental statistics, the Patient Survey. Index years were defined as 1957/1958, 1962, and 1965, and comparison years were defined 2 years before and 2 years after the index year. Subjects were patients with schizophrenia who were born in the index years of influenza epidemics. Periods 5 months after the influenza epidemics were defined as exposed months. Proportions of patients born during the exposed period in the index years were compared with those of patients born in the corresponding months in the comparison years. The proportions of patients born in the exposed months in the index years were not significantly different from those born in the corresponding months in the comparison years, with odds ratios around 1 in the whole country, the Kanto area, and the Shikoku/Kyushu area where a remarkable influenza epidemic was observed in 1957. No difference was observed in analyses stratified by sex. In Japan, there was no relationship between influenza epidemics and schizophrenic birth.

Adult↗
PubMedDate not supplied

Effect of poly(ADP-ribose) synthetase inhibitor administration to streptozotocin-induced diabetic rats on insulin and glucagon contents in their pancreas.

This study was conducted in order to clarify whether the poly(ADP-ribose) synthetase inhibitors, nicotinamide and 3-aminobenzamide, have any influence upon the content and physicochemical properties of insulin and glucagon in streptozotocin (STZ)-treated rat pancreas. STZ-treated rats received intraperitoneal injection of 350 mg/kg nicotinamide or 50 mg/kg 3-aminobenzamide 15 min before and 180 min after the administration of STZ and once a day thereafter for 23 weeks. The blood glucose levels and body weight of nicotinamide- and 3-aminobenzamide-treated rats did not differ from those of the control rats at the end of the experiment. The insulin content in poly(ADP-ribose) synthetase inhibitor-treated rat pancreas was restored partially and reached approximately 60% of the control level, while the glucagon content did not differ from that in the normal rats. Treatment with poly(ADP-ribose) synthetase inhibitor resulted in no alteration in the physicochemical properties of extracted insulin and glucagon. Immunohistological examination of the pancreas revealed that insulin- and glucagon-containing cells in the islets in the poly(ADP-ribose) synthetase inhibitor-treated rat appeared to be normalized. These results suggest that poly(ADP-ribose) synthetase inhibitor normalizes the function but not the insulin content of B cells and that it does not act on A cells in STZ-treated rat pancreas. Restoration of the insulin content would be large enough to keep the function of B cells normal.

Animals↗