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Biomedical subjects

K Seki

Publications and source records attributed to K Seki.

At least 361 records · Page 20Linked to original sources
PubMed1988

Luteinizing hormone response to domperidone in hyperprolactinaemic women with pituitary microadenomas.

Administration of a dopamine (DA) antagonist, domperidone, increased circulating levels of LH in hyperprolactinaemic-amenorrhoeic women with pituitary microadenomas but not in normal women in the early follicular phase of the menstrual cycle. This drug does not readily cross the blood-brain barrier and therefore the site of action of domperidone could be the pituitary gland or the median eminence. As the simultaneous administration of GnRH and domperidone did not increase the GnRH-induced LH release in hyperprolactinaemic women, the site of action of domperidone is likely to be the median eminence.

Adenoma↗
PubMed1988

Influence of 5-tridecylpyrazole-3-carboxylic acid, a new hypolipidaemic agent, on cholesteryl ester formation in rabbit intestinal mucosa.

The comparative effects of 5-tridecylpyrazole-3-carboxylic acid (TDPC), beta-sitosterol and melinamide on the esterification of cholesterol (CH) have been investigated in rabbit intestinal microsomes and cytosol in-vitro. The three agents did not show an effect on cholesteryl ester formation by cholesterol esterase (CEase). TDPC and beta-sitosterol did not affect cholesteryl oleate formation from oleoyl CoA by microsomal acyl CoA:cholesterol acyltransferase (ACAT), whereas melinamide significantly inhibited cholesteryl oleate formation. TDPC significantly inhibited the incorporation of oleic acid into cholesteryl oleate, which is associated with acyl CoA synthetase (ACS) plus ACAT in mucosal microsomes, at a concentration of 20-100 microM. On the other hand, 5-tridecylpyrazole-3-carbinol (TDPC-OH) a congener of TDPC, and beta-sitosterol did not show any effect. From these results, it is demonstrated that carboxylic moiety of TDPC is necessary to inhibit ACS in-vitro. According to the kinetic analytical results, it is suggested that TDPC acts as a competitive inhibitor of ACS. These results suggest that the inhibitory effect of TDPC on cholesteryl ester formation may be mediated by an inhibition of ACS activity. It is apparent from the data presented that there are substantial differences between TDPC, beta-sitosterol and melinamide with respect to their action on cholesteryl ester formation in rabbit intestinal mucosa.

Animals↗
PubMed1988

Changes in plasma cyclic AMP and cyclic GMP during spontaneous labor and labor induced by oxytocin, prostaglandin F2 alpha and prostaglandin E2.

To investigate the response of cyclic nucleotides to the oxytocic agents administered for induction of labor, plasma concentrations of cyclic AMP (cAMP) and cyclic GMP (cGMP) were determined by radioimmunoassay during spontaneous labor and labor induced by oxytocin (OT), prostaglandin F2 alpha (PGF2 alpha), or PGE2 (PGE2). Subjects were 7 Japanese women in each labor group. Plasma cAMP levels significantly rose at the time of crowning of the fetal head in all 4 groups. They did not increase until that time in the 3 labor groups (spontaneous, OT-induced, and PGF2 alpha-induced labor groups). In the PGE2-induced labor group, plasma cAMP levels were significantly higher at labor onset (mean +/- SEM = 16.5 +/- 1.3 pg/ml) when compared to the pretreatment values (13.7 +/- 1.0 pg/ml), and increased thereafter gradually toward the time of crowning of the head (26.3 +/- 2.0 pg/ml). Plasma cGMP levels in the OT-induced group significantly rose after the onset of labor and remained at a high level until expulsion of the fetus. Plasma cGMP levels in the other groups did not change significantly throughout labor. These results suggest that cAMP may be involved in the labor process induced by PGE2, and that cGMP may be in that induced by OT.

Cyclic AMP↗
PubMed1988

Serum relaxin and steroid hormones in spontaneous abortions.

To assess the capacity of the corpus luteum to secrete steroid hormones and relaxin during spontaneous abortion, human chorionic gonadotropin (hCG), progesterone, 17 alpha-hydroxyprogesterone (17-OHP) and relaxin concentrations were determined in serum samples obtained from 16 spontaneously aborting first-trimester patients and 5 asymptomatic, apparently normal women who subsequently aborted. hCG and P were subnormal in more than half of aborting patients, and 17-OHP in half of them. However, relaxin was normal in most of them. No patient with subnormal relaxin levels had hCG values in the normal range. Such a relationship was not found between hCG and 17-OHP values. Hence, decreases in placental activity seem to precede a decrease in luteal ability to secrete relaxin but not to secrete steroid hormones. Some aborting patients with subnormal 17-OHP levels had normal relaxin values. All but 1 woman who aborted subsequently had subnormal 17-OHP values at a time when relaxin levels were normal. Therefore, in some aborting patients, the ability of the corpus luteum to secrete steroid hormones is impaired at a time when its capacity to secrete relaxin is preserved.

17-alpha-Hydroxyprogesterone↗
PubMed1988

Changes in the concentrations of prostaglandins E and F in the utero-placental tissues of late pregnant rabbit after the administration of oxytocin or prostaglandin F2 alpha.

We have investigated the effects of exogenous oxytocin and prostaglandin F2 alpha (PGF2 alpha) on the concentrations of prostaglandins E and F (PGE and PGF) in the utero-placental tissues in late pregnant rabbit. The subjects were 5 rabbits each on days 26, 27 and 30 of pregnancy. After one side of the uterine horn was excised as the control, 3,000 micrograms of PGF2 alpha, 10 microU of oxytocin or 1 ml of saline was administered to 2,2 and 1 rabbits as an iv bolus dose. After 10 minutes, the remaining side of the uterine horn was excised. The myometrium, fetal and maternal cotyledon, decidua and amnion were separated. The concentrations of PGE and PGE in each tissue were measured by radioimmunoassay after extraction. The highest concentration of PGE was observed in the fetal cotyledon and that of PGF in the decidua. The amniotic PGE concentration significantly decreased after the administration of both oxytocin and PGF2 alpha. The myometrial PGF concentration increased significantly after the administration of PGF2 alpha, and the degree of the increase in PGF became greater as pregnancy advanced. However, the myometrial PGF concentration did not increase after the administration of oxytocin.

Animals↗
PubMed1988

[The development of a new operating hysteroscopic fiberscope and its clinical application].

A new operating hysteroscopic fiberscope consisting of soft and rigid parts (4.8mm outer diameter) was developed with the support of Fuji Photo Optical Company. The working part of the scope can be divided into three sections: A flexible soft front section, a rotary rigid middle section and a flexible self retained semirigid rear section. With these functional parts the intrauterine target can be approached directly to perform the following operations. 1. Directed intrauterine biopsy. Thirty-five patients diagnosed as having endometrial polyp (13), submucous myoma (8), endometrial hyperplasia (4), endocervical polyp (3), endometrial carcinoma (2) and others (5) underwent direct biopsy with hysteroscopic control. No cervical dilatation or anesthesia was necessary. 2. Transcervical recanalization. In six cases of proximal tubal occlusion, a ureteral catheter or a percutaneous coronary balloon angiocatheter was introduced into the tubal ostium of the obstructed side to resolve the occlusion successfully with concomitant laparoscopy. 3. Hysteroscopic chorionic villus sampling. Chorionic villus sampling was performed with a ureteral catheter under direct hysteroscopic control and ultrasound guidance in eighteen pregnant women at from seven to fourteen gestational weeks. In fifteen cases, the samplings were performed satisfactory. 4. Removal of a lost IUD. Three cases of lost IUD underwent hysteroscopic removal without difficulty. Our results have proved that this scope is a very useful tool for intrauterine operations.

Adult↗
PubMed1987

Histochemical demonstration of colonic type mucin in glandular metaplasia and adenocarcinoma of the human urinary bladder.

Mucin in normal, metaplastic and neoplastic tissue specimens of the human urinary bladder was examined histochemically by the periodic acid-borohydride/potassium hydroxide/periodic acid-Schiff (PB/KOH/PAS) reaction and paradoxical concanavalin A (Con A) staining, both of which have been reported to detect mucins that are specific for the lower gastrointestinal tract. Normal mucosa, Brunn's nest, squamous metaplasia, transitional cell carcinoma, and squamous cell carcinoma produced only small amount of mucin and were negative for both PB/KOH/PAS and labile class III by Con A staining. However, several sections of mucin-producing metaplastic bladder lesions and many samples of adenocarcinoma arising from vesical mucosa and urachus contained PB/KOH/PAS-positive and/or labile class III mucin. Thus the colonic type mucin appeared in some materials of both benign and malignant mucin-producing lesions of the urinary bladder. The findings would be related to the embryogenesis of this organ.

Adenocarcinoma↗
PubMed1987

Influence of the new antihypertensive drug, SM-2470 (a quinazoline derivative), on cholesterol metabolism in rats.

The influence of SM-2470 (4-amino-2-(4-[bicyclo(2,2,2)oct-2-ene-5-carbonyl]-1-piperazinyl)- 6,7-dimethoxyquinazoline), a new antihypertensive agent, on cholesterol metabolism was investigated in hypercholesterolaemic rats, using the dual isotope method (cholesterol absorption) and the intestinal ligated loop method (cholesterol uptake). In the hypercholesterolaemic model, 1-30 mg kg-1 doses of SM-2470 significantly inhibited the elevation of the total serum cholesterol and very low and low density lipoproteins (VLDL + LDL)-cholesterol, without causing any change in the hepatic cholesterol level. In a dual isotope model experiment, SM-2470 (10, 30 mg kg-1) inhibited the intestinal absorption of cholesterol, but did not affect biliary excretion of sterol and/or bile acids, nor did it affect cholesterol movement from the liver to blood. In the intestinal ligated loop method, SM-2470 remarkably inhibited the mucosal uptake of cholesterol in a dose-dependent manner in 0.5-2.0 mg mL-1 of micellar solution. In addition, SM-2470 inhibited micellar formation in-vitro, which increased the distribution of large sized micelles as well as cholesterol absorption inhibitors. From these results, it can be assumed that a possible mechanism behind the hypocholesterolaemic effect of SM-2470 is the inhibition of cholesterol absorption related to the reduction of cholesterol solubilization, occurring in the gut micelles, similar to the action of plant sterol.

Adrenergic alpha-Antagonists↗
PubMed1987

Effects of some hypolipidemic agents on biochemical values and hepatic peroxisomal enzymes in rats: comparison of probucol, CGA, KCD-232, MLM-160, AL-369 and clinofibrate with clofibrate.

The effect of some hypolipidemic agents, which are commercially available and those being developed, on certain biochemical values and on hepatic peroxisomal enzyme activities of rats were examined. Clofibrate (0.25% (w/w) in the diet), p-chlorophenoxy-isobutyryl-glycinamide (CGA) (0.25%), clinofibrate (0.1%), KCD-232 (0.1%) and MLM-160 (0.1%) increased the activities of peroxisomal fatty acyl-CoA oxidizing system, carnitine acetyltransferase, and mitochondrial carnitine palmitoyltransferase. Of peroxisomal enzymes, catalase activity was increased by the above agents, whereas the activities of D-amino acid oxidase and urate oxidase were decreased by clofibrate and CGA, and but were increased by KCD-232 and MLM-160 which are structurally unrelated to clofibrate. No influence on these enzyme activities by AL-369 and probucol treatments were observed. Hepatomegaly was induced by clofibrate, CGA, KCD-232 and MLM-160. Concerning serum lipid levels, clofibrate, CGA, clinofibrate, KCD-232 and MLM-160 decreased both cholesterol and triglyceride levels, whereas probucol decreased only cholesterol level. AL-369 had no influence on serum lipid levels under this condition using normolipemic rat. From these results, it was concluded that differing clofibrate and CGA, clinofibrate, MLM-160 and KCD-232 might not induce peroxisome proliferation in hepatic cells, although these have an influence on the enzyme composition of hepatic peroxisomes.

Animals↗