Yukitaka Miyachi

Regional distribution of sultopride and sulpiride in rat brain measured by radioimmunoassay

Sensitive and specific radioimmunoassays for both sultopride and sulpiride were developed. Using these radioimmunoassays, the regional distributions of sultopride and sulpiride in rat brain after intraperitoneal administration were investigated. Although relatively small amounts of both drugs were detected in the brain, sultopride appears to pass the blood-brain barrier more easily than sulpiride. Relatively high concentrations of sultopride were seen in hypothalamus, striatum, the mesolimbic area and hippocampus, while sulpiride accumulated mainly in brain areas such as hypothalamus, medulla oblongata and cerebellum, where the blood-brain barrier is less effective. Both drugs seem to be concentrated by the pituitary and pineal body. These differences between sultopride and sulpiride in penetration to the brain may depend on their different lipid solubilities, since sultopride has a higher lipid solubility compared with sulpiride.

Human ACTH hypersensitivity syndrome associated with abnormalities of the ACTH receptor gene

Activating mutations of the ACTH receptor have not been previously described. We investigated a 69‐year‐old woman with normal blood cortisol but undetectable blood ACTH concentrations. The aim of this study was to evaluate her hypothalamo–pituitary–adrenal axis by measuring circadian variation in blood ACTH and cortisol, and by performing CRH and ACTH stimulation and dexamethasone suppression tests. We also examined biological activity of her circulating blood ACTH using bovine adrenocortical cell suspensions and ACTH receptor gene structure by Northern blotting analysis.

Epidermal growth factor (EGF) in seminal plasma and prostatic gland: a radioreceptor assay.

The binding ability of five different cells in culture to mouse epidermal growth factor (mEGF) was studied. A simple radioreceptor assay (RRA) using normal rat kidney cell (NRK-52E) as a source of EGF receptor was established. Maximal binding capacity and apparent dissociation constant of NRK-52E cell were 3.36 femtomoles of mEGF bound per 10(6) cells and 2.85 x 10(-11) M, respectively. EGF-like activity (EGF-LA) in seminal plasma and in cytosols of prostatic gland and seminal vesicle was 39.6 +/- 9.9 ng/ml, 0.67 +/- 0.10 ng/mg protein (mean +/- SE) and less than 0.2 ng/mg protein, respectively. The EGF-LA in seminal plasma was considered to be derived mainly from prostatic gland because the EGF-LA in cytosol of prostatic gland was higher than that of seminal vesicle.

Effect of Zinc Ion on Human Chorionic Gonadotropin-Stimulated in Vitro Production of Cyclic AMP and Testosterone by Rat Testis

Summary: This study explores the effects of several divalent metal ions on the in vitro production of cyclic AMP, cyclic GMP, and testosterone by rat testicular tissue and on the amount of binding of [125I]human chorionic gonadotropin (hCG) in the testis. Zn2+ at concentrations of 10-6 to 10-4 M enhanced the hCG-stimulated production of cyclic AMP and testosterone, but only in the presence of Ca2+. [125I]hCG binding to rat testicular tissue was not affected by Zn2+. Cu2+, Ni2+, Co2+, and Mn2+ did not increase cyclic AMP or testosterone production in concentrations of 10-7 to 10-3 M and even inhibited them at a high concentration (10-2 M). Cyclic GMP production was not affected by these divalent ions. These results suggest that Zn2+ may play an important role in rat testicular steroidogenesis.

Monoclonal antibodies to human chorionic gonadotropin and their application to two-site sandwich radioimmunoassay.

Monoclonal antibodies were prepared against human chorionic gonadotropin (HCG). One monoclonal antibody recognized a conformational determinant expressed only on native HCG molecule and another monoclonal antibody had the specificity for the epitopes located on the beta-subunit of HCG. Monoclonal antibodies reacting with different antigenic determinants on the HCG molecule were used to develop a simplified 2-site sandwich radioimmunoassay in which one monoclonal antibody was immobilized and another labeled with 125iodine. This assay was highly specific for HCG and there was no cross-reactivity with alpha, beta-subunit of HCG, luteinizing hormone and follicle stimulating hormone.

Radioimmunodetection of cancer of gastrointestinal tract and liver metastasis with I-131 anti-CEA and I-131 anti-CA19-9 monoclonal antibody cocktail (IMACIS-1)

We evaluated the intravenous infusion of a cocktail of I-131 anti-CEA and anti-C A19-9 monoclonal antibody F(ab’)2 (IMACIS-1) in patients with gastrointestinal neoplasm and liver metastases in order to assess its efficacy in detecting the presence of cancer. Seven patients with primary or recurrent gastrointestinal cancer in whom liver metastases were also detected were studied. Accumulation of radioactivity in the primary tumor was seen in only one patient. Visualization of the liver metastases was achieved in all patients. Thus detection of liver metastasis was better than in primary or recurrent tumors. While tumor visualization was most often seen in the 3 day image, optimal visualization of the tumor was seen at 5–7 days. There was no correlation between the serum concentration of CEA or CA19-9 and the visualization of tumors. Serum kinetics of I-131IMACIS-1 showed biexponential components with a 1st phase T1/2 of 5.0 hours and 2nd phase T1/2 of 34.7 hours. The mean whole body (I-131) half-life determined from the whole-body scans was 1.95 days. The mean urinary excretion of I-131 in 7 days was 85%. This value agreed closely with total radioactivity retention detected by scanning. This series of studies demonstrated the potential utility of a cocktail of antibodies consisting of an anti-CEA and an anti-CA19-9 monoclonal F(ab’)2.

Radioimmunoassay of Diethylstilbestrol in Plasma of Patients with Prostatic Carcinoma

A method for the radioimmunoassay of diethylstilbestrol (DES) was established and it was used to measure the plasma concentration of DES in patients with prostatic carcinoma receiving intravenous drip infusion of 500 mg of diethylstilbestrol diphosphate (DES-DP). The sensitivity of this assay system was 40 pg per tube, with a recovery of 98%. The cross reactivity of the anti-DES antibody with estradiol, testosterone, and ethynylestradiol was less than 0.01% of DES, and that with DES-DP was 0.7%. In patients with prostatic carcinoma, plasma DES concentration at 6 and 24 hr after was declined to 10.2% and 4.4% of the level at the termination of intravenous administration of DES-DP, respectively; however, the concentration in patients with renal dysfunction was higher than that in ones with normal renal function.

Radioimmunoassay for dexamethasone 17,21-dipropionate and its metabolites in plasma and urine after topical application.

A sensitive radioimmunoassay for dexamethasone 17,21-dipropionate and its four metabolites in human plasma and urine has been developed using single anti-dexamethasone antiserum. The antiserum was obtained by immunizing rabbits with dexamethasone-3-oxime-bovine serum albumin conjugate. All of the endogenous steroids tested cross-reacted less than 0.07%. Before radioimmunoassay, dexamethasone 17,21-dipropionate and dexamethasone 17-propionate were hydrolyzed to dexamethasone, and 6 beta-OH-dexamethasone 17-propionate was hydrolyzed to 6 beta-OH-dexamethasone in 3% ammonia/methanol at 5 C for 16 h. A standard curve was established with a useful range between 0.005 and 2 ng in the case of dexamethasone, between 0.05 and 5 ng in the case of 6 beta-OH-dexamethasone. Measurement of plasma concentrations and percent urinary excretion of the metabolites in healthy men was performed following occlusive dressing of dexamethasone 17,21-dipropionate cream and ointment. The main metabolites in plasma were dexamethasone 17-propionate and dexamethasone, which increased gradually and reached maximum levels (160-200 pg/mL) at 24-32 h after application. The major metabolites observed in urine were 6 beta-OH-dexamethasone 17-propionate and 6 beta-OH-dexamethasone. Total percentage of their urinary excretions within 72 h after application amounted to 0.28-0.50% of the dose administered.

Neurotensin-like immunoreactivity (NTLI) concentration in the cerebrospinal fluid of children and its alteration in a febrile aseptic meningitis

Neurotensin-like immunoreactivity (NTLI) concentrations in the cerebrospinal fluid (CSF) of normal children and patients with febrile aseptic meningitis, aged 7 months to 15 years, were studied. The NTLI concentrations in CSF of 27 children with normal CSF findings were 160.1 +/- 54.6 pg/ml (mean +/- S.D.). The NTLI concentration in CSF of 26 patients in an acute phase of aseptic meningitis was 110.6 +/- 51.1 pg/ml which was significantly (P less than 0.01) lower than the controls. These patients had a mean temperature of 101.4 +/- 1.5 degrees F which remained elevated for an average of 3.5 days. The NTLI concentrations in CSF of 23 patients in a recovery phase (after blood and CSF findings became normal with no fever) were 166.5 +/- 57.8 pg/ml, which did not differ significantly from the normal. There were no statistical correlations between the NTLI concentration in CSF and the protein concentration or total cell count in CSF. These results suggest that NTLI concentration changes during a febrile aseptic meningitis and that it may be associated with thermoregulation.

Immunohistochemical Localization of Testosterone-Estradiol-Binding Globulin in a Clinically Hormone-Independent Prostatic Carcinoma

The localization of the testosterone-estradiol-binding globulin (TeBG) in prostate, liver and metastatic lymph node cells of a patient with hormone-independent prostatic carcinoma was studied by the t