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N Abe

Publications and source records attributed to N Abe.

At least 145 records · Page 8Linked to original sources
PubMed1988

[Studies on pulsatile secretion of thyrotropin and prolactin in hypogonadal women].

Studies of normal human subjects have shown that prolactin (PRL) as well as thyrotropin (TSH) are secreted in pulsatile fashion. This study was designed to investigate whether or not these two hormones are secreted synchronously. Ten postmenopausal women who had had amenorrhea for at least 3 years and 2 women who had been ovariectomized 3 and 5 years before and were between 35 approximately 60 yr of age were studied. Blood samples were obtained between 1500 approximately 2000 h at 15 min intervals. Distinct pulsatile fluctuation of plasma TSH concentration was present in all subjects. However, only 31% of these pulses were observed to coincide with PRL pulses. The mean (+/- SD) increment of TSH (nadir to peak) was 1.2 +/- 0.5 mu u/ml. The mean interval between pulses of TSH was 73 min. In contrast, regular episodic fluctuation of plasma PRL concentration were present in only 5 out of 12 women, and 48% of these pulses were observed to coincide with TSH pulses. These results indicate that pulses of TSH and PRL are generated independently. Since thyrotropin-releasing hormone (TRH) may be a direct generator of TSH pulse and a potent stimulator of PRL secretion, our results may suggest that physiological concentration of TRH in portal blood which is sufficient to elicit TSH pulse may be too low to elicit PRL pulse.

Adult↗
PubMed1988

[Characterization of thyroglobulin and thyroid peroxidase activity in patients with functioning thyroid benign tumors].

The content and chemical and immunological properties of thyroglobulin (Tg) and the activity of thyroid peroxidase (TPO) were studied in nodular and extranodular (periphery) thyroid tissue from patients with functioning thyroid tumors (hot nodules). From the present observations, the tumor extracts contained fairly large amounts of Tg, similar to that in the periphery tissue, while the content of Tg was markedly decreased in non-functioning thyroid tumors (cold nodules). The iodine content of Tg was significantly higher in nodular tissue compared with periphery tissue. These observations were in contrast to the results seen in the cold nodules in which hormone synthesis was defective. On the nature of carbohydrate moiety as compared with normal tissue, oligosaccharides of Tg from the periphery tissues changed in a manner similar to that of tumor oligosaccharides. That is, high-mannose type oligosaccharides were markedly decreased whereas multiantennary and unidentified oligosaccharides were increased. These observations were similar to those of non-functioning tumors. The content of sialic acid decreased markedly both in the tumor and periphery tissues. Immunologically, Tg preparations of the tumor and periphery tissue did not show the same affinity to the antibodies, depending on the content of iodine. Therefore, it seems that the contribution of the iodine content and iodo-amino acid has little or no significance in the heterogeneous nature of Tg-immunogenecity. Benign tumors and the periphery tissue were subjected to assay for thyroid peroxidase activity by the method employing guaiacol as the second substrate. The specific activities of the tumors were generally higher than those of periphery tissues, both in functioning and non-functioning benign tumors. In non-functioning carcinoma, on the other hand, TPO activities were lower in tumor portions than in periphery portions. This indicates that non-functioning thyroid carcinomas have a different characteristic.

Adenoma↗
PubMed1988

Serum luteinizing hormone profile during the menstrual cycle in polycystic ovarian syndrome.

Thirty-three patients with PCO were studied, focusing on the serum LH profile appearing during their menstrual cycles. The elevated LH level declined gradually after ovulation to the normal or near-normal range at the end of the luteal phase and the early follicular phase. The once declined LH level gradually elevated again with the increasing days from the beginning of menstrual flow and remained at a high level until the next ovulation. The LH response to LH-RH increased with the elevating basal LH level. These results may suggest that the timing of hormonal analysis is important for correct diagnosis of PCO.

Adolescent↗
PubMed1988

Purification and properties of 5-hydroxytryptamine UDP-glucuronyltransferase from rat liver microsomes.

5-Hydroxytryptamine UDP-glucuronyltransferase was highly purified from untreated rat liver microsomes. The specific activity towards 5-hydroxytryptamine was increased 178-fold over the starting solubilized microsomes with a final yield of 3%. The final preparation contained two major and one minor Coomassie brilliant blue staining polypeptide bands visible after SDS-polyacrylamide gel electrophoresis. One of the major bands was identified as 3-methylcholanthrene-inducible UDP-glucuronyltransferase, so the other (molecular weight of 55,500) appeared to be 5-hydroxytryptamine UDP-glucuronyltransferase. Concanavalin A reacted with the 55,500-dalton polypeptide. Phospholipid was indispensable for the enzyme activity. The enzyme activity in the final preparation was activated by divalent cations. Simple Michaelis-Menten kinetics were followed with respect to 5-hydroxytryptamine, but deviations from this kinetics were observed with respect to UDP-glucuronic acid and Mg2+. As regards Mg2+ stimulation, further experiments indicated that the added Mg2+ was non-competitive with 5-hydroxytryptamine, but at low concentrations of Mg2+ it was competitive with UDP-glucuronic acid and at high concentrations of Mg2+ it was non-competitive with UDP-glucuronic acid. The final preparation showed high substrate specificity towards 5-hydroxytryptamine among endogenous substrates tested. From these results, it was concluded that the enzyme described here is a new form of UDP-glucuronyltransferase isozyme, and its activity showed a peculiar dependence on Mg2+.

Animals↗
PubMed1988

Cryopreservation of Leucocytozoon caulleryi sporozoites.

Leucocytozoon caulleryi sporozoites that had been stored at -196 degrees C or -80 degrees C for 6 or 12 months in Eagle's minimum essential medium or Medium 199 supplemented with 5% glycerol and 10% chicken serum showed infectivity to chickens. Glycerol at a concentration of 10% and dimethyl sulfoxide at 10% and 5% were found to be ineffective cryoprotective agents for the low temperature preservation of sporozoites. Sporozoites isolated from the intact females of Culicoides arakawae, which had been stored at -80 degrees C for 6 or 12 months without cryoprotective agents, retained their infectivity. No differences were observed in the prepatent period, duration of parasitemia, and presence of serum-soluble antigens between chickens infected with frozen sporozoites and those infected with fresh sporozoites.

Animals↗
PubMed1988

Prolactin release in polycystic ovarian syndrome.

To evaluate the prevalence of hyperprolactinemia in patients with polycystic ovarian syndrome (PCO), 72 patients with oligo- or anovulation were studied. All of the patients had persisting elevated LH (greater than 25 mIU/ml), normal FSH, high LH/FSH ratio (greater than 2.5), and exaggerated LH responses to LHRH. Mean testosterone and androstenedione concentrations were appreciably increased in these patients. Out of 171 samples for prolactin (PRL) determination from these 72 patients, only 5 patients had a PRL value above 30 ng/ml during the first sampling. The next sampling from these same 5 women disclosed that they were transiently hyperprolactinemic because the next samples showed a normal PRL value. To further investigate the PRL secretory capacity 500 micrograms of TRH and 10 mg of metoclopramide (MCP) were administered to these 72 and 44 patients, respectively. The PRL response to MCP was significantly blunted in these patients compared to normal women while the PRL response to TRH in these patients was not indistinguishable from that in normal women. These results indicate that the true prevalence rate of hyperprolactinemia in PCO may be low rather than high and the association of hyperprolactinemia with PCO may be coincidental rather than a pathogenically related phenomenon.

Adolescent↗
PubMed1988

Deficiency of cardiac beta-adrenergic receptor in streptozocin-induced diabetic rats.

The number of beta-adrenergic receptors in cardiac myocytes isolated from rats made diabetic with streptozocin (STZ) for 10 wk was measured by use of a hydrophilic nonselective antagonist [3H]CGP 12177 and was found to decrease to 59% of the number in control rats (P less than .05), without any change in affinity. Similarly, using [125I]iodocyanopindolol as a ligand, we found a decrease in the beta-adrenergic-receptor number on cardiac plasma membrane isolated from the diabetic rats [29% decrease (P less than .05) at 1 wk, 50% (P less than .01) at 3 wk, and 49% (P less than .01) at 10 wk compared with control rats]. However, the serum triiodothyronine level that had been known to modulate the beta-adrenergic-receptor-adenylate cyclase system was decreased in the 1-wk-diabetic rats but not in the 10-wk-diabetic rats compared with each control group. Furthermore, there was no difference in urinary catecholamine excretion between diabetic and control groups. In the 10-wk-diabetic rats, the response of adenylate cyclase to isoproterenol was significantly defective (56% decrease compared with control rats; P less than .05), although both the basal and the forskolin-stimulated maximum adenylate cyclase activities and a half-maximum concentration of isoproterenol for the stimulation of adenylate cyclase were similar in control and diabetic rats. On the other hand, both cholera toxin-dependent and islet-activating protein-dependent [32P]NAD incorporations into cardiac plasma membrane were markedly increased in the diabetic rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylyl Cyclases↗
PubMed1987

Inhibitory effect of progesterone in the postcastration gonadotrophin rise in women.

This study was designed to investigate the effects of progesterone on the gonadotrophin rise after bilateral salpingo-oophorectomy (BSO). Twenty-eight regularly menstruating women underwent hysterectomy and BSO during the follicular phase of the menstrual cycle. They were divided into 5 groups depending on the treatment after BSO. Plasma LH and FSH were studied serially for 14 days after BSO and the patterns of LH and FSH rises were contrasted to those observed in the control group which received neither progesterone nor estrogen. LH and FSH levels in the group which were given low dose progesterone only, rose consistently after BSO and these patterns were similar to those seen in the control group. However, the addition of estrogen reduced gonadotrophin rises significantly more than estrogen did alone. Further, the luteal phase level of progesterone solely has a suppressive effect on the gonadotrophin rises after BSO. Our observations suggest that synergism of progesterone with estrogen may exist in suppressing gonadotrophin secretion in the normal luteal phase and should help in understanding why gonadotrophin levels in the luteal phase are lower than those in the follicular phase of the menstrual cycle.

17 alpha-Hydroxyprogesterone Caproate↗
PubMed1986

[Serum thyroglobulin levels in patients with thyroid tumor].

Serum thyroglobulin (Tg) levels were measured in 15 normal volunteers, 69 patients with differentiated thyroid carcinoma, 22 with adenoma, 45 with adenomatous goiter, 5 with functioning adenoma and 24 with Graves' disease, utilizing a double antibody radioimmunoassay technique. Serum Tg levels in the normal volunteers were found to be less than 30 ng/ml as determined from their mean value, i.e., 16.9 +/- 13.4 ng/ml (mean + 2SD), whereas serum Tg in the patients with various thyroid disorders showed significantly elevated (P less than 0.01). Serum Tg of patients with differentiated thyroid carcinoma without distant metastasis was 71 +/- 7 ng/ml (mean +/- SE), that in adenoma 124 +/- 22 ng/ml, that in adenomatous goiter 147 +/- 19 ng/ml, that in functioning adenoma 120 +/- 41 ng/ml, and that in Basedow disease 122 +/- 22 ng/ml. Furthermore, it appears that Tg concentration in serum is correlated with the size of the nodules in differentiated thyroid carcinoma (P less than 0.01) and benign nodules (P less than 0.05). Present results suggest that thyroid tumor also release Tg into serum in addition to Tg stored in the normal tissue. Furthermore, the level of circulating Tg in patient is not correlated to the level of serum TSH. In treated differentiated thyroid carcinoma, serum Tg levels were markedly reduced (21 +/- 2 ng/ml) in patients with no evidence of either recurrences or metastases, but significantly elevated in those with recurrences and/or metastases (257 +/- 109 ng/ml). Therefore, serum Tg measurements in the follow-up of patients treated for differentiated thyroid carcinoma are useful in the search for recurrences or metastases.

Adenoma↗
PubMed1986

[General pharmacology of T-2588, a new oral cephem antibiotic].

A new oral cephem antibiotic, T-2588, the pivaloyloxymethyl ester of (+)-(6R, 7R)-7-[(Z)-2-(2-amino-4-thiazolyl)-2-methoxyiminoacetamido]-3- [(5-methyl-2H-tetrazol-2-yl)methyl]-8-oxo-5-thia-1-azabicyclo[4.2. 0]oct-2-ene-2-carboxylic acid (T-2525), is mainly absorbed from the intestinal tract and biotransformed to T-2525 thereafter. General pharmacological activities of T-2588 were studied and following results were obtained. On the central nervous system, T-2588 did not show any effects at oral doses of 500-2,000 mg/kg and T-2525 produced only a slight elevation of body temperature in rabbits without any other effects at an intravenous dose of 500 mg/kg. On the respiratory and cardiovascular systems, T-2525 caused a slight hypotension and increased both respiratory rate and femoral blood flow, but no changes were observed in heart rate and electrocardiogram in dogs at an intravenous dose of 500 mg/kg. The T-2525 exerted no significant influence on blood pressure response to isoproterenol, acetylcholine or histamine, but showed a slight tendency to decrease pressor response to adrenaline in dogs at intravenous doses of 100-500 mg/kg. For the renal function in rats, T-2588 had no effects on urine volume, electrolytes and PSP excretion at oral doses of 500-2,000 mg/kg. Intravenous administration of T-2525 caused an increase of sodium excretion at 500 mg/kg and dose-dependent increases of PSP excretion at 20-500 mg/kg. Hematological studies revealed that both T-2588 at oral doses of 500-2,000 mg/kg and T-2525 at intravenous doses of 100-500 mg/kg had no effects on bleeding time in mice, blood coagulation and platelet aggregation in rats. The T-2588 exerted no effect on the gastrointestinal system in rats or mice and had no antiinflammatory activity in rats at oral doses of 500-2,000 mg/kg. The T-2525 scarcely affected the motilities of isolated smooth muscle preparations in experimental animals including stomach, ileum, colon, uterus, vas deferens and trachea at a concentration as high as 10(-3) g/ml. The T-2525 increased bile secretion in rats at intravenous doses of 100-500 mg/kg. The T-2525 slightly decreased the twitch tension of musculus gastrocnemius induced by electrical stimulation in rats at an intravenous dose of 500 mg/kg. These results indicate that T-2588 is a pharmacologically inactive antibiotic.

Animals↗
PubMed1986

[Antiemetic efficacy of high-dose hydrocortisone in patients receiving cisplatin therapy].

The effect of high-dose hydrocortisone on the emesis of patients treated with cisplatin was examined by controlled trial on 37 patients and 52 courses of chemotherapy with cisplatin combined with other cytotoxic drugs. Patients received either high-dose hydrocortisone or standard-dose of conventional antiemetics 30 minutes before chemotherapy, 4 hours after chemotherapy, and an additional dose was followed 8 hours after chemotherapy in some instances. Hydrocortisone in a dosage of 900-1,800 mg reduced cisplatin-induced nausea, vomiting and anorexia significantly when the dose of cisplatin was less than 20 mg/m2. At the dose of 1,500-2,400 mg, hydrocortisone had no efficacy for the gastro-intestinal toxicity when 30-40 mg/m2 of cisplatin was administered. After the high-dose hydrocortisone treatment for five days successively, the serum immunoglobulin level was lowered significantly. This study showed that high-dose hydrocortisone treatment was effective as an antiemetic in patients given a relatively low dose of cisplatin. However, prolonged use of high-dose steroids should be avoided. Other effective antiemetics such as metoclopramide with concomitant use of hydrocortisone would be helpful.

Adolescent↗
PubMed1985

[Comparative studies on immunological property of thyroglobulins obtained from the thyroid tumor and the adjacent tissue].

The immunological properties of thyroglobulins (Tg) of individual patients, obtained from a thyroid tumor and its adjacent tissue were compared, using conventional or monoclonal antibodies against human Tg. The thyroid tumors studied were non-functioning thyroid carcinomas and functioning thyroid adenomas. In contrast to non-functioning tumors, Tg from the functioning tumors was generally iodinated at a level close to that of normal tissue, and Tg from the tissue adjacent to the tumors had a very low iodine content. The conventional antiserum and monoclonal antibodies, B2F, seemed to recognize the conformation of Tg, while C6G showed a high affinity to Tg even when unfolded or denatured. In most cases, Tg isolated from the tissue adjacent to a tumor showed a higher affinity to antibodies than Tgs of the tumor tissue, as determined by the inhibitional effect of these Tgs against the binding of standard Tg and antibody. Furthermore, the Tg of the adjacent tissue was immunologically different in nature from the standard Tg obtained from a normal thyroid gland. From these results, Tgs of tumor and the adjacent tissue in individual patients were heterogeneous in immunological property, regardless of iodine content.

Adenocarcinoma↗
PubMed1985

Reduction in pituitary desensitization and prolongation of gonadotropin release by estrogen during continuous administration of gonadotropin-releasing hormone in women: its antagonism by progesterone.

The present study was designed to elucidate gonadal steroid influences on gonadotropin release and subsequent pituitary desensitization to GnRH. Sixteen women, 10 of whom were normal and 6 of whom had hypogonadism, were infused with GnRH at rates ranging from 0.313-10 micrograms/h via an indwelling iv catheter for 66 h. Blood samples obtained throughout the GnRH infusion were analyzed for LH, FSH, estradiol, and progesterone. A prompt and substantial release of gonadotropin occurred in women with ovarian failure or during the luteal phase in normal women compared with that during the follicular phase of the menstrual cycle. Thereafter, a gradual decrease in gonadotropin secretion occurred due to pituitary desensitization, which was slower in the follicular phase than in other groups. A dose-related increase in integrated LH release occurred during GnRH infusion, but this response tapered off with administration of large doses of GnRH to women with ovarian failure or during the luteal phase. In contrast, it increased linearly up to the maximum dose of GnRH in the follicular phase. These data suggest that 1) basal levels of estrogen suppress the early rapid release of gonadotropin in response to GnRH and reduce subsequent pituitary desensitization, resulting in the prolonged release of LH; 2) estrogen widens the range of dose-related increases in gonadotropin in response to GnRH; and 3) these effects of estrogen are antagonized by progesterone.

Adult↗