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T Tamada

Publications and source records attributed to T Tamada.

At least 163 records · Page 9Linked to original sources
PubMed1987

[Ultracytochemical localization of Ca++ATPase activity in human term amniotic epithelial cell].

In the human amniotic epithelial cell, intracellular Ca++ is known to play an important role in the initiation of parturition. Ca++ATPase is estimated to act on the regulation of the intracellular Ca++ concentration in amniotic epithelial cell. Therefore, to understand the Ca++ metabolism in human term amniotic epithelial cell, ultracytochemical localization of Ca++ATPase activity was investigated. At the same time, the ultracytochemical localization of Ca++ATPase was also compared with other phosphatases to confirm the specificity. Ca++ATPase activity was found to be positive on lateral plasma membrane of amniotic epithelial cell. The activity was strong at a 10mM Ca++ concentration. The activity was also found to be positive on the plasma membrane when 10mM Mg++ was used instead of Ca++. Acid phosphatase activity was positive on the lysosome of the amniotic epithelial cell. The other phosphatase activities appeared negative. These observations suggest that in the amniotic epithelial cell, Ca++ metabolism is active and the Ca++, entering into the cytoplasm, may flow out through the lateral membrane of the amniotic epithelial cell.

Amnion↗
PubMed1987

[Cytochemical study of the electronmicroscopical localization of Ca++ATPase activity in the human trophoblast].

Ca++ATPase is one of the most important regulatory systems that maintain the intracellular Ca++ concentration, which is essential to many cellular functions. The presence of Ca++ATPase in the human placenta has been speculated on biochemical grounds, but direct histochemical evidence has been lacking. Therefore, ultracytochemical localization of Ca++ATPase on trophoblastic cells of the human placenta was investigated by using the lead citrate method. Strong Ca++ATPase activity on the microvillous membrane and weak activity on the basal plasma membrane of the syncytiotrophoblast were observed. This distribution of Ca++ATPase was in good agreement with biochemical speculations. These results suggested that the syncytiotrophoblast might play an important role in the Ca++ metabolism in the human placenta.

Calcium↗
PubMed1987

[Experimental studies on the antitumor effect of oral antitumor agents on gynecological malignant tumors].

In order to evaluate the antitumor effect of oral antitumor agents on gynecological malignant tumors, experimental studies were carried out using nude mice which had received implants of human endometrial carcinoma. The agents used for the study were tegafur (T) and UFT, and their effects on inhibiting tumor growth, and on preventing tumors from implanting or recurring were investigated in mice in continuous long-term administrations. The results were as follows: As to the inhibitory effect on the tumor growth, while both T and UFT had no inhibitory effect on large to medium tumors, both were mildly effective on small tumors having a diameter of 2-3 mm (Inhibition Rate (IR): T-60.0%, UFT-71.0%), however, the no effect great enough to reduce the tumor size was recognized with either agent. The implantation rates of tumor under the administration of T and UFT were 80.0% and 70.0% respectively, indicating no significant differences from the control (90.0%) and either agent, however, UFT was judged to have the effect of preventing tumors from implanting to a certain extent. The recurrence rates for tumor under the administration of T and UFT were 30.0% (6/20) in both cases, which was significantly lower than the control (70.0%) (p less than 0.05). Both agents were evaluated as useful for preventing tumors from recurring. These findings, indicated that while the maintenance therapy of an oral antitumor agent has no effect on macroscopic tumors, a fairly good effect is expected on microscopic tumors, especially on the prevention of tumor recurrence.

Adenocarcinoma↗
PubMed1987

[Indication and effect of bromocriptine in euprolactinemic amenorrhea--comparison with clomiphene].

Effect of bromocriptine on induction of ovulation and occurrence of pregnancy was examined in patients with normoprolactinemic ovulatory disturbances. The patients under study (53 in number) were divided into two groups, A and B, depending on the effect clomiphene had on the ovulatory responses and the occurrence of pregnancy. Of the group A, patients (21 in number), who had failed to show any ovulatory response to clomiphene, 8 patients ovulated on bromocriptine alone. Three out of 13 patients who complained of sterility became pregnant. Three out of 8 patients who had not ovulated on bromocriptine therapy alone ovulated on a combination of bromocriptine and clomiphene, and 2 out of these 3 cases became pregnant. Of the group B patients (31 in number), who had failed to become pregnant in spite of ovulatory responses to previous clomiphene therapies, 7 out of 23 became pregnant, who complained of sterility when on bromocriptine alone. Out of 12 cases who had failed to get pregnant on the bromocriptine alone, 2 patients became pregnant on the combination of bromocriptine and clomiphene. These data may indicate that the bromocriptine or the combined therapy of bromocriptine and clomiphene is useful for the treatment of patients with ovulatory disturbances or sterility who do not respond to the clomiphene therapy.

Adult↗
PubMed1987

Hemodynamic analysis of postsplenectomy portal thrombosis using ultrasonic Doppler duplex system.

Using an ultrasonic Doppler duplex system, we investigated the portal hemodynamics of two patients with portal thrombosis after splenectomy and esophageal transection for portal hypertension accompanied by liver cirrhosis. In both cases, the preoperative blood flow volumes of the splenic and portal veins were especially high, but were markedly lower--even than normal--after the operation. However, the results of pre- and postoperative peripheral platelet counts and coagulation function tests did not differ remarkably. The dramatic change in portal hemodynamics caused by the splenectomy was thought to be the main factor in the formation of the portal thrombi.

Follow-Up Studies↗
PubMed1987

Plasma prostaglandin levels in patients with gynecologic malignancies and its fluctuations during chemotherapeutically-induced gastrointestinal toxicity.

Peripheral plasma prostaglandins (PGs) were assayed in 10 cases of gynecologic malignancies. In addition, fluctuations of PG levels during chemotherapeutically-induced gastrointestinal toxicity as well as those caused by a bolus infusion of steroid hormone were investigated. As a result, the level of PGE2 in most cases of gynecologic malignancies was seen above or around the upper limit of that in healthy women. During chemotherapy, the levels of PGF2 alpha and thromboxane B2 (TxB2) increased significantly compared to baseline levels (P less than 0.05). A bolus infusion of steroid hormone did not bring about any noticeable change in any of the levels of PGF2 alpha, TxB2, PGE2 or 6K. It may be inferred from these findings that PGs are synthesized in tumor tissue itself and released into plasma. Also, the finding that the levels of peripheral plasma PGs increased during chemotherapy suggested that such an increase in PG release could be one of the factors causing gastrointestinal toxicity. Based on the fact that there were no changes in levels of peripheral plasma PGs due to the administration of steroid hormone, however, we failed to support the proposal that steroid hormone suppresses the release of PG.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

Central signals of gallstones in magnetic resonance imaging.

The magnetic resonance imaging of gallstones was studied in 34 patients. Diagnosis of the gallstones using magnetic resonance imaging was possible in 29 patients (85%). The gallstones showed as no-signal areas in all cases, with relatively strong signals being detected from the center of the stones in six cases. Postoperative studies showed the stones with the central signals to be of the so-called mixed stone type, in which the central area consists of cholesterol with a radiating structure. The central signal was thought to originate in water that accumulates in the central cavity of the stone, the cavity not being isolated from the exterior of the stone and there being a passage of fluids. The central signal is a characteristic indication of the stone's structure.

Cholelithiasis↗
PubMed1986

Morphological and endocrinological studies on follicular development during the human menstrual cycle.

In order to clarify the morphological dynamics of follicular development and its correlation with ovarian endocrine activity, the present studies were performed in 45 regularly menstruating women who underwent gynecological surgery. Ovarian venous blood was collected from 35 women during the follicular phase. Thirteen of these 35 women were ovariectomized. In addition, 11 pairs of ovaries were obtained from women during the luteal phase. The ovaries were sectioned serially at 2.5 micron and every 13th stained slice was examined to assess the sizes and numbers of atretic and nonatretic follicles. The follicles were divided into five stages: 0.4 less than or equal to approximately less than 1.0 mm, 1.0 less than or equal to approximately less than 2.0 mm, 2.0 less than or equal to approximately less than 4.0 mm, 4.0 less than or equal to approximately less than 6.0 mm, and 6.0 mm less than or equal to approximately in follicular diameter. Estradiol concentrations in ovarian venous plasma were low on both sides on days 1 and 3 of the cycle, whereas a clear asymmetry was found on day 5 before morphological recognition of the dominant follicle. Thereafter, estradiol increased proportionally to the growth of the dominant follicle, followed by a sudden drop when ovulation was imminent. An asymmetrical rise of progesterone occurred on day 10 and later which was sustained up to ovulation. A dominant follicle was recognized in 8 of 11 women between days 6 and 14. All dominant follicles were invariably associated with higher estradiol concentrations in the ipsilateral ovarian blood. Seven of 8 dominant follicles were on the side contralateral to the preceding corpus luteum. The mean diameters of the largest nonatretic follicles were 5.4 +/- 0.3 (SE) mm during the luteal phase as a whole and 4.7 +/- 0.7 mm during the late luteal phase. The mean diameters of the largest nonatretic follicles were not significantly different between the groups with or without the corpus luteum in the luteal phase. In terms of number and atretic rate, follicles of less than 4.0 mm in diameter did not change throughout the cycle in the presence or absence of the corpus luteum. In contrast, cyclic changes of growth and atresia occurred in the larger antral follicles.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1986

Aromatization by skeletal muscle.

Because peripheral aromatization is the major source of circulating estrogens in men and postmenopausal women, we studied the aromatase activity in muscle tissue from both men and postmenopausal women. To do so, the in vitro conversion of tritiated androstenedione to estrogen in homogenates of skeletal muscles obtained at autopsy was studied. Samples from lower limb muscles of both men and postmenopausal women produced estrogen, ranging from 8.5-39.8 pg/g wet wt. The conversion was almost the same as that reported for human adipose tissue, suggesting that the contributions of muscle and fat to the extraglandular production of estrogens in these subjects might be similar. This is the first direct confirmation of muscle aromatase activity and indicates the possible importance of muscle as an extragonadal source of estrogen in both men and postmenopausal women.

Aged↗
PubMed1986

Reevaluation of immunoreactive gonadotropin-releasing hormone (GnRH) levels in general circulation in women: changes in levels and episodic patterns before, during and after gonadotropin surges.

In order to reevaluate the earlier varying data regarding circulatory gonadotropin-releasing hormone (GnRH), we assayed extracted GnRH from the plasma frequently collected at mid-cycle in 11 women. For the analysis of episodic GnRH patterns and basal levels, blood samples were obtained at 6 h intervals for 72 h and at 15 min intervals for 2 h every 12 h throughout the experimental period. All blood samples were assayed for GnRH and selected samples for LH, FSH, estradiol and progesterone. For GnRH assay, 5 or 6 ml of blood was mixed with 60 mg of ethylenediaminetetraacetic acid, disodium salt, and 3 mg of phenylmethylsulfonyl floride immediately after blood collection. These enzyme inhibitors prevented the destruction of GnRH in the blood at room temperature for at least 4 h. Plasma GnRH was extracted through several steps including florisil absorption, acidic extraction and washing with organic solvent. Nonspecific immunoreactivity in the plasma was markedly decreased through this extraction process. Our assay values (approximate range, 0.1-2.0 pg/ml) of plasma GnRH in normal women corresponded to the low range of those obtained by others who used the alcohol extraction method. The basal levels of GnRH did not change significantly throughout 3 different periods, i.e., before, during and after the LH surges, and fluctuated between a small range of 0.11 and 1.44 pg/ml. Although the peak levels of GnRH observed in its episodic patterns did not change between the periods before and during the LH surges, they decreased significantly after the LH surge compared with those seen during the LH surges (0.93 +/- 0.07 vs 1.17 +/- 0.09 pg/ml, p less than 0.05). The present data demonstrate that immunoreactive GnRH in the extracted peripheral plasma does not change significantly in its mean, basal and peak levels during the periovulatory period except for a minor but significant decrease in the peak levels shortly after an LH surge.

Adult↗
PubMed1986

Evaluation of GnRH administration on the prolactin response to thyrotrophin-releasing hormone in normal women.

To determine whether GnRH modifies prolactin (PRL) secretion in response to thyrotrophin-releasing hormone (TRH) in normal women, a group of eleven normal women, 23 to 40 years of age, was studied in the mid-follicular phase of the menstrual cycle. The PRL response to TRH was evaluated in serum under control conditions and after GnRH infusion. GnRH administration augmented basal PRL release and amplified TRH-induced PRL release. These results suggest that GnRH may be involved in PRL release, partly by increasing the sensitivity of the lactotrophs to TRH.

Adult↗