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Biomedical subjects

K Seki

Publications and source records attributed to K Seki.

At least 415 records · Page 23Linked to original sources
PubMed1985

Effects of diltiazem and nitroglycerin on prostaglandin F2 alpha-induced periodic contractions of isolated human coronary arteries.

This study characterizes the inhibiting effect of diltiazem and nitroglycerin on periodic contractions of isolated human coronary arteries. Isometric force of coronary ring segments from sixty-nine cadavers was recorded in a muscle bath. To quantify the experimental results, we used 3 X 10(-6) M prostaglandin F2 alpha to induce the periodic contractions of a certain force. When diltiazem was added during the periodic contractions, the amplitude of oscillations gradually decreased until eventually oscillations ceased completely. The process prior to the cessation of the oscillations was characterized mainly by the inhibition of the contraction phase. The inhibition rate at the time of the complete cessation of oscillations was 49.3 +/- 6.3% at 5 X 10(-7) M. The time required for complete disappearance of oscillations was dependent on the diltiazem concentration. When nitroglycerin was added during periodic contractions, the oscillations did not disappear. Compared to the contraction phase, the relaxation phase was appreciably inhibited. With only 10(-7) M diltiazem, the rate of inhibition of the contraction phase was 22.0 +/- 7.7%, whereas the preliminary treatment with 5 X 10(-8) M nitroglycerin led to a complete cessation of the oscillations, and suppression of the level of the contractions to a significantly greater extent, viz. 58.7 +/- 5.8% (p less than 0.001). Therefore, it is considered more effective in the treatment and prevention of coronary spasm to use diltiazem and nitroglycerin simultaneously rather than individually.

Benzazepines↗
PubMed1985

Role of atherosclerosis in spontaneous periodic contractions of isolated postmortem human coronary arteries.

The role of atherosclerosis in coronary artery spasm was studied by morphometrical examinations of isolated postmortem human coronary arteries that were used for the observation of spontaneous periodic contractions. Isometric tension of coronary ring segments from seventy-six cadavers was recorded in a bath containing physiological saline solution. According to the degree of atherosclerosis, the segments were classified into three groups: minimum intimal lesion (Group I), moderate intimal lesion (Group II) and severe atherosclerotic lesion (Group III). Results were analyzed by a chi-square test. The incidence of the spontaneous periodic contractions was 45% in the proximal portion. Of the segments in which the contractions occurred, 83% were in Group II. There were significant differences in the incidence between Group I and II (33% vs 80%; p less than 0.02) and Group II and III (80% vs 25%; p less than 0.001), respectively. According to the characteristics of the atherosclerosis, there were significant differences in incidence of the contractions between circumferential thickening and eccentric thickening in Group II (63% vs 28%; p less than 0.001). In conclusion, the spontaneous periodic contractions occur most frequently in the segments in which (1) the degree of atherosclerosis is moderate rather than minimum or severe and (2) the characteristics of atherosclerosis is circumferential thickening instead of eccentric thickening.

Adolescent↗
PubMed1985

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

In order to determine whether endogenous dopaminergic tone has any role in the diurnal variation in TSH secretion, the 24-h secretory pattern of TSH and the TSH response to a dopamine antagonist, metoclopramide (MCP), were evaluated in normal women (n = 4) and in hyperprolactinemic-amenorrheic women with pituitary microadenoma (n = 6). TSH concentrations expressed as percent deviation from the 24-h mean significantly differed with respect to time of day in normal women and hyperprolactinemic women. They were significantly higher during the night (2000-0700 h) than during the daytime (0800-1900 h). Whereas MCP administration induced no significant changes in serum TSH levels in normal women, it significantly increased serum TSH levels in hyperprolactinemic women. Thus, the diurnal variation in TSH secretion was demonstrated in hyperprolactinemic women with pituitary microadenoma in the face of an increased dopaminergic inhibition of TSH secretion. The present study did not provide evidence that the diurnal pattern of TSH secretion is related to the endogenous dopaminergic tone.

Adenoma↗
PubMed1985

The secretory patterns of relaxin and human chorionic gonadotropin in human pregnancy.

Relaxin and human chorionic gonadotropin (hCG) were simultaneously determined in the same serum samples obtained from pregnant women. Although the secretory pattern of relaxin, in general, appeared to parallel that of hCG during human pregnancy, several discrepancies were discerned in the secretory patterns of the two hormones. The mean hCG concentration significantly differed between weeks 4-7 and 8-11 of pregnancy, but the mean relaxin concentration did not. The mean relaxin concentration began to decrease at weeks 16-19 whereas that of hCG did so at weeks 12-15. The mean relaxin concentration at weeks 4-7 was significantly higher than that at weeks 24-27, though there was no significant difference between the mean hCG concentrations in the two periods. These differences in the secretory pattern of relaxin from that of hCG indicate that relaxin secretion in pregnancy is not determined only by the circulating level of hCG. The responsiveness of the corpus luteum of pregnancy to hCG stimulation of relaxin secretion may vary as a function of the age of the corpus luteum, and this may partially account for the differences between the secretory pattern of relaxin and that of hCG observed in the present study.

Animals↗
PubMed1985

Correlation between urinary oestrogen levels determined by haemagglutination inhibition reaction and serum oestradiol levels determined by radioimmunoassay.

Measurement of urinary or blood oestrogen is essential for a precise monitoring of follicular development in gonadotrophin therapy. Blood oestradiol levels are considered most accurately to reflect follicular maturation. Although radioimmunoassays (RIA) for oestradiol yielding rapid results are now available, they require qualified technicians and equipment for RIA. Recently, a simple, rapid method for determining urinary total oestrogen has been developed by Mochida Pharmaceutical Co. Ltd., Japan. To determine whether this kit may be applicable to monitoring gonadotrophin therapy, urinary total oestrogen concentrations measured by the kit were compared with serum oestradiol levels determined by RIA in patients who were treated with gonadotrophin. Urinary total oestrogen concentrations in samples obtained either at 07.00 h (first morning urine specimen) or at 09.00 h significantly correlated with serum oestradiol levels. Thus, urinary total oestrogen concentrations determined by the kit appear to reflect follicular development accurately, and are considered applicable to monitoring gonadotrophin therapy. Correction of the urinary total oestrogen concentrations by the creatinine level significantly improved the correlation between urinary total oestrogen values and serum oestradiol levels. Therefore, the primary total oestrogen values should be corrected by the creatinine level.

Chorionic Gonadotropin↗
PubMed1985

[Clinical experience on aztreonam].

Aztreonam (AZT), a new monobactam antibiotic, was studied for clinical efficacy in the field of gynecologic infection. AZT was administered at a daily dose of 2 g in 2 divided doses by single shot intravenous injection. The subjects were patients with the following infections: adnexitis (6), pelvic peritonitis (5), endometritis (1) and wound abscess (1). Good response was seen in 10 patients out of 13. The overall efficacy rate of 76.9% was obtained. Slight increase in GOT, GPT and Al-P was seen in 1 case. It was normalized on 6th day after completion of the therapy. No notable side effects were observed.

Adult↗
PubMed1985

Effect of increased systemic venous pressure on thoracic duct and peripheral lymph flow in dogs.

In congestive heart failure, lymph flow from the cannulated thoracic duct is greatly increased. However, there has been scant data on lymph flow in the intact lymphatic system with systemic circulatory congestion. In the present study, thoracic duct and peripheral lymph flow were qualitatively determined using heated cross-thermocouples in seven mongrel dogs. Central venous pressure was raised artificially by infusing large volumes of crystalloid solution equivalent to a maximum of 30% of body weight. Although both thoracic duct and peripheral lymph flow increased with an intact (closed) lymphatic system, the increase was notably less than with a transected (opened) cervical thoracic duct. With systemic circulatory congestion, cannulated thoracic duct lymph flow circumvents a major lymph impediment to lymph flow (i.e. high central venous pressure) and therefore considerably overestimates in vivo central lymph flow in this condition.

Animals↗
PubMed1985

Establishment and characterization of a new human cultured cell line from a prolactin-secreting pituitary adenoma.

A new human cell line was established from a prolactin (PRL) secreting pituitary adenoma. This cell line, designated as HPA, initially produced and secreted PRL, but the ability was decreased with increasing passage number. After about 30 passages in vitro, these cells had a short doubling time (14 h) and a low plating efficiency (9%). When a minimum of 10(5) cells was injected per mouse, virtually all athymic nude mice developed a slow growing, nonmetastasizing tumor at the injection site about 30 days after injection. PRL production by the HPA cells after Day 150 was demonstrated by immunocytochemistry as well as radioimmunoassay. In addition, cimetidine (10(-4) M) had a significant stimulatory effect on PRL secretion by 4-day-cultured HPA cells. When the HPA cells were incubated in the presence of 5.0 and 10.0 nM bromocriptine, the proliferation rate was inhibited to 53.4 and 25.1% of untreated controls, respectively. On the other hand, the same concentrations of bromocriptine did not affect the proliferation rate of YK cells derived from human immature teratoma of the ovary. In addition, bromocriptine inhibited significantly the growth rate of xenotransplanted HPA but not YK cells. These results suggest that bromocriptine inhibits specifically the proliferation of HPA cells.

Adenoma↗
PubMed1984

Effect of high doses of synthetic estrogen on lipid metabolism in castrated male rats.

The mechanism by which high doses of estrogen influences lipid metabolism was studied with a microtubular blocking agent. Castrated male rats received oral injection daily for 14 days of 3 mg hexestrol in olive oil, or oil alone as controls. About half of the animals in each group were injected intraperitoneally with 4 mg/100 g body weight colchicine 3 hr before they were killed. Hexestrol treatment caused an accumulation of esterified cholesterol in the liver while it decreased those in serum. Triglyceride concentrations slightly decreased in the liver but were unaffected in serum. On polyacrylamide-gel disc electrophoresis, the peaks of high density lipoproteins (HDL) and low density lipoproteins (LDL) were decreased remarkably. Electron microscopic examination of hepatocytes revealed electron-lucent lipid droplets in the cytoplasm. After a colchicine treatment of the control animals, concentrations of esterified cholesterol and triglycerides markedly increased in the liver, while those in serum decreased. Electron microscopic examination of hepatocytes revealed numerous secretory vesicles filled with nascent VLDL. In hexestrol-treated animals, the colchicine treatment was associated with marked decreases in serum-esterified cholesterol and triglyceride as seen in the controls. However, there were no further increases of esterified cholesterol in the liver, and the increase of triglycerides was slight. Electron microscopic examination showed less secretory droplets than in the controls. These data suggest that very low density lipoproteins (VLDL) synthesis in the liver of hexestrol treated rats was inhibited. An accumulation of esterified cholesterol with a marked decrease in serum could not be accounted for by the inhibition of lipoproteins secretion, but rather by their enhanced entry into the liver.

Animals↗