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Biomedical subjects

Y Okamura

Publications and source records attributed to Y Okamura.

At least 217 records · Page 12Linked to original sources
PubMed1985

Echographic findings and histological feature of the thyroid: a reverse relationship between the level of echo-amplitude and lymphocytic infiltration.

In 43 patients with Graves' disease, 5 patients with painless thyroiditis and 30 patients with Hashimoto-thyroiditis ultrasonographical observations and histological examinations by needle biopsy of the thyroid were carried out simultaneously. In all cases the level of echo-amplitude was well correlated with the rate of lymphocytic infiltrations and fibrosis. In cases which exhibited marked lymphocytic infiltrations in the thyroidal biopsy specimen, no apparent echoes or very low amplitude echoes were observed in the whole thyroid and in cases in which replacement with lymphocytic infiltration was observed in almost a half part of the thyroid, several sonolucent regions were observed in the thyroid and in cases in which lymphocytic infiltration or fibrosis was observed sporadically, low-amplitude and uniform echoes were observed in the whole or several regions of the thyroid. In cases with no lymphocytic infiltration in the histological specimen, diffuse high-amplitude and uniform echoes were observed throughout the whole lobe of the thyroid. In patients with painless thyroiditis, the amplitude of echo was low when the level of lymphocytic infiltration was high and the echo-amplitude showed a tendency to increase along with the decrease in the rate of lymphocytic infiltration. From these observations it is concluded that echo-amplitude is well correlated with lymphocytic infiltration and fibrosis in patients with Hashimoto-thyroiditis, Hashitoxicosis and painless thyroiditis.

Graves Disease↗
PubMed1984

Synaptic regulation of hypothalamic neurons containing ACTH by substance P.

Synaptic connections between substance P (SP)- and ACTH-containing neurons in the rat arcuate nucleus were studied by a technique of combined pre- and postembedding immunohistochemical staining. The results showed that immunoreactive (ir) SP fiber terminals form synapses with ir ACTH cell bodies. This strongly suggests that the activity of ACTH neurons is under neuronal regulation by SP neurons.

Adrenocorticotropic Hormone↗
PubMed1984

Hypothalamic substance P-containing neurons. Sex-dependent topographical differences and ultrastructural transformations associated with stages of the estrous cycle.

Immunoreactive substance P (ir SP)-containing neurons were examined in rat hypothalamus. In untreated males, few if any ir perikarya were found in the arcuate nucleus, but after intraventricular colchicine administration, many appeared not only in the arcuate nucleus but also in the premammillary region, posterior hypothalamic, ventromedial, dorsomedial, subthalamic and paraventricular nuclei, and zona incerta. This was also the case in females treated with colchicine on the second day of diestrus. In untreated females, perikarya were seen only in the arcuate nucleus, varying in number and ultrastructure during the estrous cycle and being maximal in number in proestrus and estrus. The perikarya possessed well-developed Golgi bodies and lamellar bodies composed of many closely apposed cisternae of endoplasmic reticulum in proestrus, and showed stacks of two or three cisternae of endoplasmic reticulum as well as lysosomes in estrus. In diestrus, the perikarya had only a few granulated vesicles and fragmental cisternae of endoplasmic reticulum. In the perikarya of colchicine-treated males, many granulated vesicles and lysosomal bodies were noted. These findings suggest that, among the widely distributed SP neurons in the hypothalamus, some in the arcuate nucleus are involved in the hypothalamic-hypophysial-gonadal axis.

Animals↗
PubMed1984

Immunohistochemical study on the development of CRF-containing neurons in the hypothalamus of the rat.

Appearance of immunoreactive corticotropin-releasing factor (CRF)-containing neurons was studied in developing hypothalamus of the rat by use of antisera against rat- and ovine CRF. These neurons were first recognized in the lateral and paraventricular nuclei on days 15.5 and 16.5 of gestation, respectively, when antiserum against rat CRF was employed. Antiserum against ovine CRF revealed the cells two days later exclusively in the latter nucleus. In both nuclei, the neurons increased in number with development. The neurons in the paraventricular nucleus appeared to project their immunoreactive processes to the median eminence via the periventricular and lateral pathways. In the median eminence, the immunoreaction with antiserum to rat CRF was first recognized in its anterior portion in the form of dots on day 16.5 of gestation but as beaded fibers in the external layer on day 17.5; these structures increased in amount with development in rostro-caudal direction. Although antiserum to ovine CRF was less potent in immunostainability than antiserum to rat CRF, it also revealed the beaded fibers in the median eminence on day 17.5 of gestation. Since evidence is available that the paraventricular nucleus is involved in corticotropin release, it is concluded that, in rats, the hypothalamic regulatory mechanism controlling the release of corticotropin initially appears on days 16.5-17.5 of gestation.

Animals↗
PubMed1984

[Ultrasound-guided renal cyst puncture and 95% ethanol instillation. Part 2: Morphological and functional alterations].

Ultrasound-guided renal cyst puncture was performed on 22 cysts which were then 95% ethanol instilled to prevent recurrence of cystic fluid. Cystic lesions disappeared on the ultrasonogram in the follow-up period of 3 to 28 months. On CT, cystic lesions became smaller size but did not disappear. Average CT numbers of the cyst were 8.75 +/- 3.83 before and 12.96 +/- 3.27 after ethanol instillation. The cystic wall became thicker. Caliceal distortion and/or pelvis compression by cystic lesions improved on IVP 2 to 3 days after ethanol instillation. The renal image on Tc-99m-DMSA scintigram showed morphological improvement and DMSA renal uptake rate increased slightly but significantly 2 to 4 weeks after ethanol instillation. There were no major complications with this procedure except for one case in which the tip of the catheter became stuck in the cyst and broke off when the catheter was removed. A slight local irritable pain was noticed in all cases. Half of the patients had hot flushes and/or somewhat drunken sense but these symptoms were only temporary. Antabuse phenomenon appeared in one case with concomitant use of a cephem antibiotics after ethanol instillation. This method of therapy is a safe non-surgical approach to treat renal cysts. 95% ethanol instillation in the cyst seems to prevent recurrence of cystic fluid.

Adult↗
PubMed1983

[Side effects of antithyroid drugs].

In order to investigate the incidence of side effects of antithyroid drugs and to study if there were any factors related to the onset of the side effects, clinical and laboratory findings were examined in 71 untreated Graves' patients. The overall incidence was 28.2% among 71 cases who were initially administered methimazole or propylthiouracil. The incidences were 23.2% (13 of 56 cases) for methimazole and 46.7% (7 of 15 cases) for propylthiouracil, respectively, which were significantly higher than those previously reported. Seventeen of 20 cases with side effects under the drug of first choice were administered the another antithyroid drug. Four of 17 (23.5%) cases successively had side effects. The side effects were observed within 1.5 months of administration of less than 150 tablets in total in most of the cases. The serum concentration of Ig-E and peripheral eosinophils(/mm3) at the onset of the side effects were significantly higher than those before treatment. These results suggest that allergic mechanism rather than accumulating may concern the onset of side effects. Since in cases without the side effects the peripheral eosinophils at 3 to 4 weeks after administration were significantly higher than those before treatment and 19 of 51 (38.0%) cases without side effects had a high concentration of Ig-E of more than 500 u/ml, it is suggested that allergic mechanism may be triggered in most of Graves' patients who were administered methimazole or propylthiouracil. Thus, immunological disturbances in Graves' disease seems to be the cause of the side effects of antithyroid drugs, although there was no correlation between antithyroid autoantibodies and development of the side effects.

Adolescent↗
PubMed1983

A new therapeutic method for climacteric disorders.

At the present time the administration of an exogeneous estrogen for the treatment of climacteric disorders is generally accepted both in Japan and foreign countries. However, there have been several reports to show that estrogen will promote carcinogenecity. With special attention to this point, the author performed the endocrinological treatment without estrogen for climacteric disorders. The author would like to propose the reactivation method on functionally declining ovary by the approach of induction of ovulation. In this paper the author describes a successful case treated by the new method of hormone therapy.

Administration, Oral↗
PubMed1983

Ontogenetic studies on the topographical heterogeneity of somatostatin-containing neurons in rat hypothalamus.

The ontogeny of the somatostatin-containing neuron system was investigated by light-microscopic immunohistochemistry. During development, immunoreactive somatostatin-containing neurons arise from three discrete regions of the neuroepithelium of the third ventricle and show a chronological difference. The neurons are first evident within the third ventricle floor on day 12.5 of gestation; they move thereafter to the arcuate nucleus. The second generation occurs in the dorsal region of the arcuate nucleus during days 17.5-19.5; these neurons migrate sequentially into the arcuate-ventromedial nuclear region. The third generation is recognized in the neuroepithelial cell layer of the rostral hypothalamus on day 17.5 of gestation; these cells move to the periventricular area. This latter generation is most prominent during days 3-6 after birth, and some of the cells are seen sporadically even up to day 20. The first two generations give rise to the somatostatin neuron system in the arcuate-ventromedial nuclear region, while the latter gives rise to that in the rostral periventricular region in the adult rat hypothalamus.

Animals↗
PubMed1983

Ontogenesis of hypothalamic immunoreactive ACTH cells in vivo and in vitro: role of Rathke's pouch.

The ontogenesis of immunoreactive (ir) ACTH cells and ir alpha-MSH cells in rat hypothalamus was studied in vivo and in vitro. Ir ACTH cells first appeared in the neuroepithelial cell layer lining the floor of the third ventricle on Day 13.5 of gestation, whereas ir alpha-MSH first appeared in the cytoplasm of several ir ACTH cells in the basal part of the arcuate nucleus of the hypothalamus on Day 19.5. When the medial-basal hypothalamus of 12.5-day embryos was cultured alone, a few ir ACTH cells were found after culture for 10 days, but not 3 days, and no ir alpha-MSH cells were observed in the cultures. When the hypothalamus was cultured with Rathke's pouch (intact or without the intermediate lobe anlage), ir ACTH cells appeared within 3 days. In these cultures on Days 6 and 10, long beaded fibers were seen projecting from cells in the neuronal tissue, and some cells showed immunolabeling for alpha-MSH. When the hypothalamus was cocultured with oral epithelium instead of Rathke's pouch, the appearance of neuronal ir ACTH cells was like that in cultures of hypothalamus alone. These in vitro findings suggest that stimulus from the anterior lobe anlage of the pituitary is necessary for normal development of ir ACTH/alpha-MSH cells in the hypothalamus.

Adrenocorticotropic Hormone↗