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Biomedical subjects

T Yanase

Publications and source records attributed to T Yanase.

At least 163 records · Page 9Linked to original sources
PubMed1985

Mechanism of dissociation of cortisol and adrenal androgen secretion after removal of adrenocortical adenoma in patients with Cushing's syndrome.

We investigated the mechanism of dissociation of cortisol and dehydroepiandrosterone sulfate (DHEA-S) secretion by the adrenal glands after the removal of an adrenal gland containing an adrenocortical adenoma in a patient with Cushing's syndrome. After removal of the adrenocortical adenoma, the serum cortisol rapidly decreased from 24.6 +/- 6.4 micrograms/dl (mean +/- SD, n = 6) to 0.7 +/- 0.5 micrograms/dl. Serum DHEA-S levels were 15 +/- 14 micrograms/dl and 6 +/- 9 micrograms/dl before and after surgery, respectively, and significantly lower than the control values. Serum cortisol levels reverted to normal levels 1.5 to 3 years after the surgery. On the other hand, DHEA-S levels reverted to normal 5 to 7 years after the serum cortisol levels had normalized. Monolayer cultures of normal human adrenal cells obtained at adrenalectomy in patients with advanced breast cancer and atrophic adrenal cells adjacent to the adrenocortical adenoma in patients with Cushing's syndrome were used to study the mechanism of the dissociation of cortisol and DHEA-S secretion. ACTH caused significant increases in the productions of pregnenolone (P5), progesterone (P4), 17-hydroxypregnenolone (17-OH-P5), 17-hydroxyprogesterone (17-OH-P4), DHEA, DHEA-S, androstenedione (delta 4-A), and cortisol. The amounts of 17-OH-P5 and 17-OH-P4 produced by ACTH in atrophic adrenal cells were significantly greater than those in normal adrenal cells. The amounts of DHEA, DHEA-S and delta 4-A produced by ACTH in atrophic adrenal cells were significantly smaller than those of normal adrenal cells. The conversion rate of 17-OH-[3H]P5 to 17-OH-[3H]P4 and 11-deoxy-[3H] cortisol was higher in atrophic adrenal cells than in normal adrenal cells, but the conversion rate to [3H]DHEA, [3H]DHEA-S and [3H]delta 4-A was significantly lower in atrophic adrenal cells than in normal adrenal cells. These results suggest that the dissociation of cortisol from DHEA-S after the removal of adrenocortical adenoma is a probably due to diminished C17,20-lyase activity in the remaining atrophic adrenal gland.

Adenoma↗
PubMed1985

Probable ACTH-secreting pituitary tumour in association with Addison's disease.

A 61 year old Japanese man with a diagnosis of Addison's disease was admitted to Kyushu University Hospital for further investigation of high ACTH levels and hyperpigmentation which 37.5 mg of cortisone acetate failed to alleviate. The basal level of plasma ACTH was 700-1000 pg/ml, and following 25-37.5 mg cortisone acetate or 1 mg dexamethasone the levels were 300-600 pg/ml. The general pigmentation showed little improvement with such medication. Radiographic studies revealed a double floor of the sella turcica and cisternal herniation. These observations suggested the existence of a pituitary ACTH-secreting tumour. Plasma ACTH showed a circadian rhythm ranging from 440 to 1570 pg/ml and it was not suppressed to a normal range by oral administration of dexamethasone, 8 mg/day or by continuous infusion of dexamethasone, 1.25 mg/h for 2 h. Plasma ACTH responses of 80% above basal level to lysine-vasopressin (LVP), and 12% above basal to synthetic ovine corticotrophin releasing factor (CRF) were observed. FK 33-824, a methionine-enkephalin analogue, suppressed plasma ACTH to 85% of basal level, while bromocriptine (CB-154) caused no significant change. These findings led to a diagnosis of pituitary ACTH-secreting adenoma (corticotropinoma) in association with Addison's disease. The persistent circadian rhythm of plasma ACTH suggested that this adenoma may not be completely free from regulation by the central nervous system. This case may be clinically significant for investigation of the pathogenesis of pituitary adenoma, particularly in Nelson's syndrome.

Addison Disease↗
PubMed1984

Dexamethasone increases both catecholamines and methionine-enkephalin in cultured bovine adrenal chromaffin cells and human extramedullary pheochromocytoma cells.

The effect of dexamethasone on dispersed cells in primary monolayer culture from bovine adrenal medulla and human extramedullary pheochromocytoma was examined by estimating the level of catecholamines (CAs) and Methionine-enkephalin (Met-enk) in the medium and cells. In cultured bovine adrenal chromaffin cells, dexamethasone caused significant increase in Met-enk levels 18 hours after administration. There was no release of Met-enk and CAs in the medium 10 min after administration, although nicotine did cause a significant release of Met-enk and CAs. A dose response increase in the level of CAs and Met-enk in bovine adrenal chromaffin cells was obtained with doses varying between 0 and 10(-6)M dexamethasone 18 hours after administration. In cultured human extramedullary pheochromocytoma cells, dexamethasone significantly increased the levels of norepinephrine and Met-enk in a dose dependent manner 24 hours after administration. These results suggest that dexamethasone does not act as a secretagogue but may be related to the synthesis of Met-enk and CAs.

Adrenal Medulla↗
PubMed1984

Selective IgA deficiency: analysis of Ig production in vitro.

The cellular basis of the pathogenesis of selective IgA deficiency (SIgAD) was investigated by examining surface immunoglobulin (SmIg) and in vitro pokeweed mitogen (PWM)-stimulated immunoglobulin (Ig) synthesis and by assaying in combination the counterpart lymphocytes from individuals with SIgAD and healthy donors. Peripheral blood lymphocytes (PBL) from 14 individuals with SIgAD synthesized normal amounts of IgG and IgM but did not synthesize normal amounts of IgA. Functional defects of lymphocytes for IgA synthesis were classified into four types: (i) B-lymphocyte dysfunction, (ii) increased function of suppressor T lymphocytes (Ts), (iii) decreased function of helper T lymphocytes (Th), and (iv) B-lymphocyte dysfunction and increased Ts function. The cells bearing SmIgG, SmIgM, and SmIgD were demonstrated at normal percentage ratios in all cases by immunofluorescent staining. The cells bearing SmIgA were at normal percentage ratios in the cases of T-lymphocyte dysfunction, while in the cases of B-lymphocyte defect SmIgA-bearing cells were reduced.

Adult↗
PubMed1984

Distribution of alpha 2-macroglobulin in normal, inflammatory, and tumor tissues in rats.

Distribution of uptake and catabolism of intravenously administered 125I-labeled rat alpha 2-macroglobulin(125I-alpha 2MG) were examined in normal, inflammatory, and tumor tissues of rats. Clearance of intravenously administered [125I]alpha 2MG from the circulation was rapid. Accumulation of this compound into inflammatory tissue was 2-3 times more extensive than in normal tissues. The accumulation into sarcoma tissue was much less. Radioactivity in TCA-PTA precipitates remained fairly constant for the first 12 h in inflammatory tissue and for the first 24 h in sarcoma. These patterns of accumulation were never observed in the normal tissues. As the kidney preferentially accumulated large amounts of [125I]alpha 2MG in the nondegraded form and its degradation products, the tissue may play a special role in the metabolism of alpha 2MG. Rapid clearance from the circulation and relatively small amounts of accumulation in tissues suggest that alpha 2MG may function as a protease inhibitor, mainly in the circulation rather than in the tissues.

Animals↗
PubMed1984

Effect of angiotensin II on secretion of adrenal androgens.

To assess the effect of angiotensin II (A II) on the secretion of human adrenal androgens (AA), plasma dehydroepiandrosterone (DHEA), DHEA sulfate (DS) and delta 4-androstenedione (delta 4-A) were measured in eight normal men 60 and 120 min after stimulation of endogenous A II by a bolus injection of 40 mg frusemide, and the direct effect of A II on the secretion of adrenal androgens was examined in cultured human adrenocortical cells in the presence of a low concentration of ACTH. The administration of frusemide led to a significant increase in the plasma DHEA and DS concentration as well as plasma renin activity (PRA) and aldosterone concentration (PAC), but did not change plasma cortisol and delta 4-A. In the culture of human adrenocortical cells, 10(-9)-10(-5) M A II or 10(-13) M ACTH alone did not stimulate the secretion of DHEA, DS and delta 4-A, while 10(-7) and 10(-5) M A II in the presence of 10(-13) M ACTH caused a significant increase in DHEA and DS secretion with no change in delta 4-A. These results suggest that the activated renin-angiotensin system stimulates the secretion of adrenal androgens by a direct effect of A II on adrenal cortical cells.

Adrenal Cortex↗
PubMed1984

Hereditary spherocytosis associated with a variant of band 3 protein in the erythrocyte membrane.

A 17-year-old woman with hereditary spherocytosis was found to be heterozygous for an unusual variant of the band 3 protein in erythrocyte membranes. The variant had a molecular weight of 95,000 daltons which was larger by about 3,000 daltons than the 92,000 m.w. normal band 3, and was phosphorylated less efficiently when intact cells were incubated with 32P-inorganic phosphate. It is discussed that this variant may affect the integrity of the membrane skeletons.

Adolescent↗
PubMed1984

Erythroid colony forming cells in systemic lupus erythematosus.

The incidence of erythroid progenitor cells in the bone marrow was studied in 9 patients with systemic lupus erythematosis (SLE) in the absence of corticosteroid or immunosuppressive therapy. The incidence of late erythropoietic precursors (CFU-E) was diminished in SLE. The colony formation of marrow CFU-E was inhibited by the addition of allogeneic and autologous T lymphocytes from SLE patients before the prescription of corticosteroid. These results suggest that the T cell mediated suppression of erythroid progenitor cells may play an important role in a pathogenesis of erythropoietic failure in SLE.

Adult↗