Search PubMed⌕ Search

Biomedical subjects

H Okada

Publications and source records attributed to H Okada.

At least 973 records · Page 54Linked to original sources
PubMed1987

Serum and urinary estrone sulfate during the menstrual cycle, measured by a direct radioimmunoassay, and fate of exogenously injected estrone sulfate.

Serum and early-morning urinary levels of estrone sulfate during the menstrual cycle were measured by a direct radioimmunoassay without hydrolysis. These levels were high and showed prominent peaks [serum, 2.67 +/- 0.37 ng/ml (mean +/- SE); urine, 5.82 +/- 2.3 micrograms/l] around the day of the preovulatory estradiol-17 beta peak, and increased again during the luteal phase. Following intravenous injection of estrone sulfate, serum estrone sulfate, estrone and estradiol-17 beta were measured. The conversion of estrone sulfate to estrone and/or estradiol-17 beta was very small during their transit in the general circulation.

Adolescent↗
PubMed1987

The role of thyroid hormone as a biological amplifier of the actions of follicle-stimulating hormone in the functional differentiation of cultured porcine granulosa cells.

To characterize thyroid hormone action on the ovary, the direct effects of T4 or T3 were investigated in vitro using a monolayer culture system of porcine granulosa cells. Monolayer cultures were maintained for 6 days in 4% serum-supplemented medium in the absence or presence of porcine FSH (20 ng/ml), with or without graded doses of T4 or T3. Combined treatment with FSH and T4 (10(-7) M) induced morphological alternation resembling epithelioid cells, while FSH alone or T4 alone failed to bring about the epithelioid morphology. Concomitant treatment with FSH and T4 (10(-7) M) markedly increased FSH-stimulated induction of [125I]iodo-human CG binding to cultured granulosa cells obtained from small follicles. The combined treatment with FSH and T4 (10(-7) M) also resulted in a significant increase in progesterone and estrogen secretion by the cultured cells relative to treatment with FSH alone. Increases in progesterone, 17 beta-estradiol, and estrone secretion caused by the combined treatment with FSH and T4 (10(-7) M) were further augmented in response to the addition of exogenously provided substrate pregnenolone, testosterone, and androstenedione, respectively. Furthermore, aromatase activity assessed by the release of [3H]water from [1 beta-3H, 4-14C]androstenedione was significantly higher in cells treated concomitantly with FSH and T4 (10(-7) M) than that in cells treated with FSH alone. All the stimulatory effects of T4 (10(-7) M) on the morphological and functional differentiation of cultured granulosa cells were also found in combined treatment with FSH and T3 (10(-9) M). Either treatment with higher or lower concentrations of T4 or T3 gave attenuated effects, and T4 or T3 alone without FSH was incapable of exhibiting these stimulatory effects. These findings suggest that thyroid hormones synergize with FSH to exert direct stimulatory effects on granulosa cell functions, including morphological differentiation, LH/human CG receptor formation and steroidogenic enzyme (3 beta-hydroxysteroid dehydrogenase and aromatase) induction. Hence, decreases in ovarian functions during the states of hypo- or hyperthyroidism may account for diminished responsiveness of the granulosa cells to FSH.

Animals↗
PubMed1987

Reflex responses of neurons in the inferior mesenteric ganglion to mechanical stimulation of the colon, rectum, anal canal, and urinary bladder in the dog.

Unitary discharges were recorded from the inferior mesenteric ganglion of decerebrate dogs. Eighty-one units were identified as sympathetic postganglionic neurons innervating the colon and rectum by collision test performed by stimulation of the lumbar colonic nerve. Discharges of four units were enhanced simultaneously with an increased outflow of the renal nerve by pinching a toe. Thus, those units were regarded as vasoconstrictors of colonic blood vessels. Sixty-five units whose discharges were depressed or not affected by the pinching were regarded as neurons innervating colonic smooth muscle or mucosa (colonic units). Discharges were enhanced in the majority of the colonic units by colonic, rectal, and vesical distension, and mechanical stimulation of the anal canal, while discharges were depressed in a few units by rectal and vesical distension, and the anal canal stimulation. The number and percentage of the depressed units increased not only after cutting the hypogastric nerves and descending branches of the lumbar colonic nerve but also after transection of the caudal pons. The reflex depressions disappeared after transection at the bulbospinal junction, but the reflex enhancements remained. These results indicate that the colonic units are enhanced through a spinal reflex by the inflows from the distal colon, rectum, anal canal, and urinary bladder through the lumbar colonic, hypogastric, pelvic, and pudendal nerves, while a few are inhibited through a supraspinal reflex by inflows through the pelvic and pudendal nerves.

Action Potentials↗
PubMed1987

Effects of antral distension on pancreatic exocrine secretion in dogs: evidence for a short reflex.

In chloralose anesthetized dogs and decerebrated dogs whose pyloric sphincter was submucosally ligated, the pancreatic exocrine secretory response to antral distension was studied. Distensions of the antral pouch with Tyrode's solution and 0.1 N HCl caused graded rises in pancreatic flow and protein and bicarbonate outputs. The serum gastrin concentration gradually rose after the distention with Tyrode's solution, while no rise in serum gastrin was elicited by acid distension. After cervical vagotomy, a reduced pancreatic response persisted but no rise in the serum gastrin was seen. After splanchnicectomy following vagotomy, the pancreatic response became greater than before splanchnicectomy. This pancreatic response was observed even after caeliac and superior mesenteric ganglionectomies, but was completely abolished by an external tight ligature around the pyloric sphincter, or by administration of hexamethonium or atropine sulfate. The results suggest the existence of an antropancreatic short reflex in addition to a long route vago-vagal reflex.

Animals↗
PubMed1987

The structure of inducing factors for virginiamycin production in Streptomyces virginiae.

Virginiamycin inducing factors (inducing material or inducing factor) of Streptomyces virginiae were isolated from the culture broth of this microbe and separated into three closely related compounds. They were named virginiae butanolides A, B and C and their structures were determined as 2-(1'-hydroxy-5'-methylhexyl)-3-(hydroxymethyl)butanolide (6), 2-(1'-hydroxy-4'-methylhexyl)-3-(hydroxymethyl)butanolide (7) and 2-(1'-hydroxyhexyl)-3-(hydroxymethyl)butanolide (8), respectively. Part of their stereochemistry was also determined. Racemic virginiae butanolide C was synthesized to confirm their structures.

4-Butyrolactone↗
PubMed1987

[Hormone dependency and progestogen therapy in the treatment of endometrial cancer].

The anti-tumor activities of steroid compounds on endometrical cancer (Ishikawa cell line) were examined in vitro by human tumor clonogenic assay (HT CA). Clinically effective progestational compounds including medroxyprogesterone acetate (MAP), and 17 alpha hydroxy-progesterone caproate were effective. Norethindrone (ENT), which is also a potent progestational compound, and RU486, which is known to be a progesterone antagonist were ineffective in this in vitro system, neither having any influence on the effect of MAP. These results indicated that the anti-tumor activity of MAP did not proceed via the so-called progesterone receptor system. Morphological changes induced by MAP in undifferentiated endometrial cancer, the effectiveness of tamoxifen, hormonochemotherapy, and the use of MAP for adjuvant therapy and prophylaxis were also discussed.

17 alpha-Hydroxyprogesterone Caproate↗
PubMed1987

[Clinical studies of BRL 28500 (clavulanic acid/ticarcillin) in the treatment of pelvioperitonitis and Douglas' abscess].

Clinical studies were conducted on BRL 28500 (a formulation containing 15 parts ticarcillin plus 1 part clavulanic acid). BRL 28500 was administered at doses of 1.6 g or 3.2 g b.i.d., generally for 10 days by drip infusion to patients with pelvioperitonitis or Douglas' abscess. The results obtained were summarized as follows. 1. Clinical efficacy was evaluated in 18 patients (pelvioperitonitis 14, Douglas' abscess 4), but 8 patients out of a total of 26 patients were excluded. 2. In the evaluation of clinical improvement by doctors in charge, clinical improvement rates were 44.4% on day 3, 88.2% on day 5. 3. On the basis of committee judgement, the clinical efficacy rate was 100%. 4. The bacteriological eradication rate of causative organisms was 100% in 11 patients (15 strains). Five strains out of a total of 15 strains produced beta-lactamase. 5. As a side effect, nausea was observed in 1 case. In laboratory examination, liver function abnormalities were observed in 1 case. 6. Regarding usefulness as judged by doctors in charge, the satisfactory rate was 83.3%. From the above results, it has been concluded that BRL 28500 is very useful in the treatment of pelvioperitonitis and Douglas' abscess.

Abscess↗
PubMed1987

[Antimicrobial effect of human endometrial peroxidase on Escherichia coli and Staphylococcus aureus].

Human endometrium had potent peroxidase activity and an antimicrobial effect. Relationships which existed between the human endometrial peroxidase and antimicrobial effect were studied. Human endometrial peroxidase activity was measured by the modified method of Himmelhoch. In the normal menstrual cycle, the peroxidase activity in the secretory phase was higher than in the proliferative phase. The peroxidase activity in endometrial carcinoma was remarkably higher than in the normal menstrual cycle. The organisms (E.coli, S.aureus) and peroxidase extract were incubated for 60 min at 37 degrees C. Bacterial viability was determined by the plate culture method. The viable cell count was decreased. Endometrial peroxidase had an antimicrobial effect on E.coli and S.aureus. But the antimicrobial effect on clinically isolated S.aureus exerted by the peroxidase was not effective. Although the peroxidase activity in the endometrial carcinoma was higher than in the normal endometrium, there was no detectable antimicrobial effect. Peroxidase of endometrial carcinoma was suspected of having some different characteristics from normal endometrium.

Endometrium↗
PubMed1987

[Male infertility with chromosomal abnormalities. II. XX-male syndrome].

We report two cases of the XX-male syndrome, and review the literature. The first case was a 31-year-old married man, a welder, complaining of infertility. His height was 158 cm, weight 82 kg and distance of extended hand 155 cm. The external genitalia showed a normal male type, but bilateral small testes and gynecomastia were noticed. The second case was a 32-year-old married man, a shopkeeper, complaining of infertility. His height was 165 cm, weight 60 kg and distance of extended hand 167 cm. No gynecomastia was noted. The external genitalia showed a normal male type, but bilateral small testes were noticed. In each case, azoospermia was identified in semen analysis. Urethrography revealed the prostatic utricle in the second case. The testicular biopsy specimens revealed hyalinization of seminiferous tubules and proliferation of Leydig cells. X chromatin was positive in buccal smears, and Y chromatin negative in cultured lymphocytes. Chromosomal analysis showed 46, XX karyotype in the first case and 46, XXp+ in the second case. H-Y antigen was positive in each case. Basal serum levels of LH and FSH were moderately elevated and the serum testosterone level was low. Serum levels of PRL, TSH, estradiol, GH, T3 and T4 were normal. An impaired response by testicular Leydig cells to hCG was observed. The LH and FSH responses to LH-RH were almost normal. Clomiphene citrate administration resulted in a decrease in the serum testosterone and gonadotropins levels. These results indicate hypergonadotropic hypogonadism secondary to testicular failure in both XX-males. Twenty-six cases of the XX-male syndrome have been cited in the Japanese literature. The clinical features and etiology of this syndrome are discussed.

Adult↗
PubMed1987

Suicide inactivation of androstenedione aromatase in human placenta by fluoroethindrone (10 beta-fluoro-17 alpha-ethynyl-19-nortestosterone).

The inhibitory effects of androstenedione aromatase activity in human placenta using fluoroethindrone (10 beta-fluoro-17 alpha-ethynyl-19-nortestosterone), which is a derivative of norethindrone (17 alpha-ethynyl-19-nortestosterone, ENT) and, unlike ENT, is considered to be refractory to aromatization, was investigated in this study. When fluoroethindrone was added to the placental microsomes in the presence of NADPH, androstenedione aromatase activity in the placental microsomes was decreased time dependently and dose-dependently by fluoroethindrone compared with the samples without NADPH. This finding suggests that fluoroethindrone acts as a suicide substrate for androstenedione aromatase in human placenta.

Aromatase Inhibitors↗