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Biomedical subjects

K Seki

Publications and source records attributed to K Seki.

At least 379 records · Page 21Linked to original sources
PubMed1987

Twenty-four hour secretory pattern of growth hormone in hyperprolactinemic women with pituitary microadenoma.

The 24-h secretory pattern of GH was evaluated in normal women (n = 4) and hyperprolactinemic-amenorrheic women with pituitary microadenoma (n=6). Serum GH concentrations significantly differed according to the time of day, and there were nocturnal rises in normal women and hyperprolactinemic women. However, episodic fluctuations in serum GH levels were almost absent during the day time in hyperprolactinemic women, and the mean 24-h GH concentration was significantly lower in these women than in normal women. Thus, GH secretion was diminished in hyperprolactinemic women with pituitary microadenoma, though a nocturnal increase in GH secretion continued.

Adenoma↗
PubMed1987

Decrease in serum prolactin during bromocriptine-induced pregnancy and subsequent restoration of reproductive function in some hyperprolactinemic women.

Twenty-two women with hyperprolactinemia and amenorrhea were followed up for at least 18 months after 22 bromocriptine-induced full term pregnancies. Return of menstruation occurred in 9 of the 22 patients after pregnancy. Five of them conceived subsequently without any treatment. The prolactin (PRL) concentration before or during bromocriptine treatment was not significantly different between the patients who conceived spontaneously and those who did not. However, the PRL concentration after weaning was significantly lower in the patients who conceived spontaneously than in those who did not. Serum PRL levels were normal or only slightly elevated in the patients who conceived spontaneously. In 11 of the 22 patients, PRL levels were serially determined during bromocriptine-induced pregnancies. In 7 of the 11 patients, serum PRL levels fell during the second or third trimester. Spontaneous pregnancy occurred in 3 of the 7 patients who showed a decrease in PRL values during pregnancy, but in none of the 4 patients who did not. Furthermore, PRL levels after weaning correlated with PRL levels during the third trimester in these 11 women. Consequently, a decrease in PRL values during pregnancy may result in a fall in PRL levels after pregnancy, which in turn leads to the restoration of reproductive function in some subjects.

Adult↗
PubMed1987

Serum immunoreactive relaxin in women during a 24-h period.

Serum relaxin concentrations were measured every 30 min during a 24-h period in nonpregnant and pregnant women. Relaxin was undetectable in all serum samples obtained from 3 nonpregnant women. Relaxin was detectable in all serum samples obtained from 2 pregnant women. However, neither episodic secretion of relaxin nor a 24-h rhythm in relaxin secretion was discernible in these women.

Adult↗
PubMed1987

Evidence for the luteal source of circulating relaxin in molar pregnancy.

Serum levels of relaxin rapidly decreased in patients with hydatidiform mole who underwent hysterectomy and bilateral salpingo-oophorectomy. However, the disappearance pattern of relaxin in patients with hydatidiform mole who underwent hysterectomy only was delayed and similar to that after evacuation of mole. The findings constitute evidence of the luteal source of circulating relaxin in molar pregnancy.

Fallopian Tubes↗
PubMed1987

Effect of nicorandil on exercise performance in patients with effort angina: a multicenter trial using a treadmill exercise test.

The effects of a single oral dose (20 mg) of a new vasodilator, nicorandil, on exercise performance were assessed in 29 patients with stable effort angina using a symptom-limited treadmill exercise test. A single-blind, placebo-controlled, randomized, crossover design was employed. Compared with placebo, 20 mg of nicorandil significantly increased maximal exercise duration and time to 1 mm of ST-segment depression at 1, 3, and 6 h after administration. Systolic blood pressure was reduced both at rest and during exercise. Heart rate increase during exercise did not differ significantly compared with control, though resting heart rate was increased. The maximal pressure-rate product at peak exercise was increased in association with increased exercise time in about half of the patients, while it was unchanged or decreased in the others. It was suggested that nicorandil may act by either reducing myocardial oxygen demand and/or increasing myocardial oxygen supply.

Adult↗
PubMed1987

Induction of tumors in the liver, urinary bladder, esophagus and forestomach by short-term treatment with different doses of N,N'-dibutylnitrosamine in rats.

The multipotential carcinogen N,N'-dibutylnitrosamine (DBN) was given to F344 male rats for 2 weeks at three dose levels to study the concentration dependence of its organ specificity. Groups of 20 rats were given water containing 0.25, 0.125 or 0.063% DBN for 2 weeks and then tap water only to drink until they were killed 52 weeks after the start of the experiment. DBN induced preneoplastic lesions in the liver, esophagus, forestomach and urinary bladder. Carcinoma was found only in the liver. Induction of preneoplastic focal hepatocyte lesions positive for the P-form of glutathione S-transferase (GST-P) was quantitatively dependent on the dose of DBN. In the urinary bladder, the incidences of papillary or nodular hyperplasia (PNH) and papilloma of transitional cells tended to increase at higher doses. The incidence and number per unit length of basal cell-type hyperplasias of the esophageal epithelium were significantly higher in all DBN groups than in the control group, through the increase did not show a clear dose-dependency. The incidence of epithelial basal cell hyperplasia of the forestomach was significantly increased at all doses and the increase was apparently dose-related. These results indicate that even in a short-term experiment, DBN exerted multipotential carcinogenic effects. Thus, this system could be used for assay of the modifying effects of compounds administered subsequently on carcinogenesis in different organs.

Animals↗
PubMed1987

[Oily chemoembolization of hepatoma].

Since 1983 we have performed transcatheter oily chemoembolization (TOCE) using adriamycin (40-100 mg), Lipiodol (5-20 ml) and Gelfoam in the treatment of 100 cases with unresectable hepatocellular carcinoma. Adriamycin was dissolved in a fluid equal in specific gravity to Lipiodol and the adriamycin solution was mixed with 3 volumes of Lipiodol, making an adriamycin-in-oil emulsion (AOE). After TOCE, the blood concentration of adriamycin was obviously lower than that after one-shot injection because of the slow release of adriamycin from the AOE. Also, in cases of hepatic resection after TOCE, there was a clear difference in the adriamycin concentration between the tumor and the normal hepatic tissue. The cumulative survival rates for the 100 patients treated by TOCE were: 6 months 81.9%, 1 year 53.8% and 2 years 36.5%. Thus, improvement was found in comparison with the cumulative survival rates for 104 patients who underwent hepatic embolization without Lipiodol, which were 6 months 67.4%, 1 year 45.2% and 2 years 16.3%. AOE retained in the tumor as microemboli brings about the slow-releasing effect of adriamycin. Furthermore, by adding the effect of Gelfoam embolization, TOCE has a strong antitumor effect.

Carcinoma, Hepatocellular↗
PubMed1987

[Chemoembolization].

Chemoembolization is a technique by which the blood flow in the artery feeding a tumor is arrested and, at the same time, an antitumor agent is delivered in a high concentration to the target site in anticipation of a synergistic antitumor effect. Usually, this is a transcatheter technique. The embolic materials used to arrest the blood flow include gelatin sponge, Lipiodol, microcapsule, albumin microsphere, degradable starch microsphere and the like. Since the gelatin sponge and Lipiodol are available on the market, transcatheter oily chemoembolization (TOCE) using these two materials was performed in cases of hepatic tumor. In many cases of TOCE, adriamycin was used as an adriamycin solution Lipiodol mixture (adriamycin-in-oil emulsion). The cumulative survival rates for 100 patients with unresectable hepatoma treated by TOCE were 53.8% for one year and 36.5% for two years. Thus, improvement was observed in comparison with the cumulative survival rates of 104 patients who underwent hepatic embolization without Lipiodol (1 year, 45.2%, 2 years, 16.3%). Adriamycin-in-oil emulsion retained in the tumor as microemboli brings about the slow-releasing effect of adriamycin. The effect was demonstrated in the blood and tissue concentrations of adriamycin following TOCE.

Aged↗
PubMed1987

Changes in plasma oxytocin, prostaglandin E1, and 13,14-dihydro-15-keto-prostaglandin F2 alpha during labor induced by prostaglandin E2 or F2 alpha and spontaneous labor.

To observe the changes in endogenous oxytocics during spontaneous and induced labor, the plasma concentrations of oxytocin, prostaglandin E1 (PGE1) and 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) were measured during labor in 9 cases of spontaneous labor (group 1), 10 of PGE2-induced labor (group 2), and 7 of PGF2 alpha-induced labor (group 3). Unextracted samples were used for radioimmunoassay of oxytocin. PGE and PGF were extracted and separated for radioimmunoassays of PGE1 and PGFM. Although oxytocin levels in groups 1 and 3 did not change during labor or slightly increased toward delivery, those in group 2 decreased as labor progressed. The mean oxytocin in group 2 was significantly lower at the times of established labor (15.3 +/- 3.2 microU/ml, mean +/- SE) and crowing of the fetal head (10.8 +/- 2.0 microU/ml) than before labor (52.7 +/- 14.8 microU/ml). Plasma PGE1 levels in groups 1 and 3 were low and did not change during labor. Plasma PGFM levels in groups 1 and 2 gradually rose toward delivery. These results suggest that exogenous PGE2 suppresses oxytocin secretion during labor and stimulates endogenous PGF2 alpha production, that endogenous PGE1 may not play an important role in the progress of spontaneous and PGF2 alpha-induced labor, and that endogenous PGF2 alpha may participate in the promotion of all kinds of labor.

Alprostadil↗
PubMed1986

Monitoring by alpha-hydroxybutyrate dehydrogenase of human ovarian carcinoma grown in nude mice.

In order to establish that the tumor burden in nude mice bearing a xenografted human ovarian tumor can be assessed by measuring plasma levels of alpha-hydroxybutyrate dehydrogenase (HBD) (E.C. 1.1.1.30), the plasma HBD and the tumor volume were measured every week after inoculation of a human ovarian carcinoma cell line designated HR. About 3 weeks after tumor inoculation, all nude mice had a palpable tumor while elevated levels of HBD were observed in a half of the mice at that time. Thereafter the HBD levels rose with increasing tumor volume. There was a quantitative linear relationship between the tumor weight and HBD activity per mouse. When 40 micrograms of cisplatin (about 2 mg/kg) was administered i.p. every week for 5 weeks 2 weeks after inoculation, plasma levels of HBD were significantly decreased on day 27 compared to those in untreated nude mice. Decreases in the HBD levels during treatment with cisplatin occurred 7 days prior to changes in tumor volumes. Further, removal of local tumor mass resulted in a marked decrease in HBD levels on day 1 after surgery and the HBD levels in nude mice which had no recurrent tumor fell into the normal range 8 days after surgery.

Animals↗
PubMed1986

Circadian, sleep and brain temperature rhythms in cats under sustained daily light-dark cycles and constant darkness.

In adult cats, sleep-wake states and brain temperatures were determined under experimental LD cycles and prolonged DD. Convincing rhythms had not previously been well-established for this animal. The present results demonstrated daily fluctuation in total sleep time (TST) and in brain temperature (Tb). These comprise predominantly nocturnal wakefulness and high temperatures but include a bi-modal component marking dawn and dusk peaks. In addition there are ultradian variations with a period of 2-4 hour superimposed on the circadian rhythm. The latter continued at the beginning of prolonged DD, but gradually diminished and disappeared after about ten days. The TST circadian rhythm diminished more quickly than the Tb rhythm. This result suggests that the former is coupled more strongly to the circadian oscillator than the latter, and that the brain temperature rhythm could not depend on the circadian rhythm of sleep-wakefulness. These results encourage use of cats in further chronobiological studies of sleep and other physiological rhythms.

Activity Cycles↗
PubMed1986

Ovulatory disturbances. Causative factors among Japanese student nurses in a dormitory.

The incidence of ovulatory disturbances in student nurses living in a restricted circumstance was evaluated by observing a basal body temperature (BBT) chart recorded for three to nine months by all of the student nurses in our medical college. The students were 18-21 years of age and were all living in a school dormitory. One hundred of the 154 students (64.9%) were anovulators during the school term. However, 40 of the anovulators showed ovulatory cycles with biphasic BBT patterns during their spring and/or summer holidays. The subjects' living conditions were investigated by questionnaire. Age of menarche, sport activity, self-perceived physical and mental work load, and native region did not appear to be related to their ovulatory disturbances. Weight-height-derived indices indicated that the anovulators had a tendency to corpulence as compared to the regular ovulators. Serum luteinizing hormone, follicle stimulating hormone, and prolactin levels of the anovulators were not significantly different from the regular ovulators.

Adolescent↗
PubMed1986

Absence of growth hormone response to L-dopa and bromocriptine in hyperprolactinemic women with pituitary microadenoma.

The administration of an amino acid precursor of both dopamine and norepinephrine, L-dopa, or of a dopamine agonist, bromocriptine, did not alter basal GH secretion in hyperprolactinemic women with pituitary microadenoma, whereas both significantly increased serum GH levels in normal women. The findings cannot be accounted for by decreased pituitary GH reserve, since in hyperprolactinemic women, insulin elicited an increase in GH levels similar to its action in normal women. Thus, the mechanism by which L-dopa or bromocriptine stimulates GH secretion appears to be different from that of insulin.

Adenoma↗