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Y Oki

Publications and source records attributed to Y Oki.

At least 73 records · Page 4Linked to original sources
PubMed1997

Adrenal adenoma with bilateral adrenocortical nodular change in a patient with Cushing's syndrome.

We report a 57-year-old male patient with adrenocorticotrophin (ACTH)-independent Cushing's syndrome and long-standing hypertension. Both abdominal computed tomographic scan and magnetic resonance imaging revealed bilateral adrenal enlargement with the presence of a tumour in the left adrenal. Marked uptake of 131I-6 beta-iodomethyl-19-norcholesterol was observed only in the left adrenal gland. Left adrenalectomy and biopsy of the right adrenal gland were subsequently performed. Histological examination revealed the presence of an adrenocortical adenoma in the left adrenal with multiple adrenocortical nodules in both left and right non-neoplastic adrenals. Peri- and intraadrenal arteries and arterioles demonstrated marked arteriosclerotic vascular changes. Immunoreactivity for several steroidogenic enzymes was present in the tumour and markedly diminished in the non-neoplastic adrenals. This patient with Cushing's adenoma is considered to have developed adrenocortical nodules in the nonneoplastic adrenal possibly as a result of localized compensatory overgrowth of adrenocortical cells in response to ischaemic changes due to arteriopathy. When examining patients with Cushing's syndrome and bilateral adrenal enlargement, the possibility of concomitant adenoma and adrenocortical nodule formation should also be considered in the differential diagnosis

3-Hydroxysteroid Dehydrogenases↗
PubMed1997

Urocortin expression in human pituitary gland and pituitary adenoma.

Urocortin is a recently identified neuropeptide of the CRF family in the mammalian brain, but its expression in human tissue has been little studied. In this study, we examined urocortin expression in human anterior pituitary gland and pituitary adenomas by RIA, high performance liquid chromatography, immunohistochemistry, messenger ribonucleic acid (mRNA) in situ hybridization, and reverse transcriptase-PCR. Immunoreactive urocortin concentrations in normal pituitary tissue extract were 103.25 +/- 39.05 ng/g wet wt (mean +/- SEM; n = 4), and their levels were all significantly higher than those in other portions of central nervous system of the same subjects. High performance liquid chromatography analysis of human pituitary extract demonstrated a single peak corresponding to that of the expected chromatographic mobility of synthetic human urocortin-(1-40). Urocortin-immunoreactive cells were detected in the anterior pituitary gland. Neither urocortin-immunoreactive nerve fibers nor cells were detected in the posterior lobe. Immunostaining in serial mirror tissue sections revealed that 76.55 +/- 3.06% of urocortin-immunoreactive cells expressed GH immunoreactivity, whereas 22.25 +/- 3.02% and less than 1% of urocortin-immunoreactive cells expressed PRL and ACTH, respectively. mRNA hybridization signals of urocortin were also detected in urocortin-immunopositive pituitary cells. The reverse transcriptase-PCR analysis demonstrated a 145-bp RNA band corresponding to that of the expected length of urocortin in all cases of normal pituitary glands examined (n = 3). We also immunostained urocortin in 52 cases of human anterior pituitary adenomas, including GH-producing adenomas (n = 14), ACTH-producing adenomas (n = 13), PRL-producing adenomas (n = 11), and nonfunctioning hormonally inactive adenomas (n = 14). No urocortin immunoreactivity was detected in these adenoma cells, except for one case of GH-producing adenoma and one case of nonfunctioning adenoma. We also performed mRNA in situ hybridization in 27 adenomas. No hybridization signals were detected in these adenomas, except in two cases. The results described above indicated that urocortin is synthesized in human anterior pituitary cells and may play an important role in biological features of normal pituitary gland, possibly as an autocrine or a paracrine regulator

Adenoma↗
PubMed1997

DNA topoisomerase II alpha and Ki-67 in human adrenocortical neoplasms: a possible marker of differentiation between adenomas and carcinomas.

Cell kinetic information is valuable in evaluating the diagnosis and/or biologic behavior of various human neoplasms. Monoclonal antibody Ki-67 recognizes the cells other than G0 of the cell cycle. A cell cycle-related intranuclear protein, topoisomerase II alpha (topoII alpha), separates chromosomes at the end of mitosis. Its expression is mostly limited to the S to G2/M phases of the cell cycle. We studied cell proliferative activity in adrenocortical adenomas (n = 28), carcinomas (n = 17), and normal adrenal glands (n = 6) by immunohistochemical analysis of Ki-67 and topoII alpha to evaluate their value in the diagnosis of adrenocortical malignancy. We detected Ki-67 and topoII alpha immunohistoreactivity in the nuclei of each case we examined. There was a significant positive correlation (r = 0.927) between the Ki-67 and topoII alpha labeling indexes (LIs), the percentage of positive cells. In normal adrenal cortex and adenoma, the LIs for Ki-67 and topoII alpha were 0.48 +/- 0.16 and 0.44 +/- 0.15 for normal and 0.64 +/- 0.11 and 0.72 +/- 0.12 for adenoma, respectively, with no significant differences in the LIs of adenomas and normal adrenals. The Ki-67 and topoII alpha LIs in the carcinomas were 5.84 +/- 1.33 and 6.13 +/0 1.65, respectively; these LIs were significantly higher than the LIs of adenomas. Eleven of 17 carcinomas demonstrated topoII alpha and Ki-67 LIs of more than 2.5, whereas none of the adenomas did. The topoII alpha and Ki-67 LIs in carcinomas with metastasis (11.21 +/- 3.15 and 9.75 +/- 2.31 respectively; n = 7) were significantly higher than in those without metastasis (2.58 +/- 0.61 and 3.12 +/- 0.90, respectively; n = 10). This indicates that immunohistochemical analysis of Ki-67 and topoII alpha could help to differentiate carcinoma from adenoma in resected adrenocortical neoplasms and might predict aggressive biologic behavior in carcinomas.

Adenoma↗
PubMed1996

A rare case of ectopic antidiuretic hormone-producing pancreatic adenocarcinoma: new diagnostic approach.

We describe a 73-year old man with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) due to an ectopic ADH-producing pancreatic adenocarcinoma. His laboratory findings showed marked hyponatremia, and the water load test showed uncontrolled ADH secretion. The imaging studies revealed pancreatic body cancer. Histological examination revealed an adenocarcinoma of the pancreas, which was positive for ADH immuno-staining. The ADH in the tumor extract was 53.3 pg/g wet weight. In attempt to diagnose ADH-production from the tumor, the ADH in his pancreatic juice was measured and found to be 2.1 pg/ml. We conclude that it is valid to measure the ADH in pancreatic juice to diagnose ectopic ADH production by tumors.

Adenocarcinoma↗
PubMed1996

[Prognostic factors of nasopharyngeal carcinoma treated by radiotherapy].

This study was a retrospective analysis of 82 patients with histologically confirmed nasopharyngeal carcinoma, who were treated at Keio University Hospital from March 1983 to March 1993. We studied all cases(62% of them were stage IV) with regard to their prognostic factors and chronic side effects induced by radiation. All patients were received extended-field radiotherapy from the base of the skull to the supraclavicular lymph node area. The five- and ten-year overall survival rates for the entire group were 59% and 49%, respectively. Three stage I patients were alive without recurrence or metastases for more than 5 years. The ten-year survival rate stage II-III for patients (23 patients) was 78%, and for stage IV (56 patients) 37%. The five-year survival rate of patients in T2-3 group without lymph node metastasis was 88%, while it was reduced to 55% for patients with metastasis. The prognosis of T4 patients was very poor: their five-year survival rate was 37% with lymph node metastasis, and 35%, without lymph node metastasis. Patients under 46 years old showed an increased survival rate compared with patients over 46 years old. Patients who completed less than 52 days of radiation therapy found to have a better prognosis than those receiving radiation for a longer period. Our multivariate analysis indicated that age, radiation period and N-factor were statistically significant in influencing prognosis. Hearing loss occurred relatively high with 20% of cumulative incidence in our study, probably because they received radiation therapy with the extended field including bilateral middle and inner ear. Extended-field radiotherapy for patients with nasopharyngeal carcinoma might contribute to improving their cure-rate, and precise radiation planning is warranted to avoid the late complications such as hearing loss.

Adenocarcinoma↗
PubMed1995

Clinical significance of no-reflow phenomenon observed on angiography after successful treatment of acute myocardial infarction with percutaneous transluminal coronary angioplasty.

The clinical significance of the angiographic no-reflow phenomenon was evaluated in 93 patients with acute myocardial infarction treated by percutaneous transluminal coronary angioplasty (PTCA). On the basis of the post-PTCA angiograms, patients were divided into three groups: normal angiogram (group 1, n = 65), slight no-reflow (group 2, n = 13), and severe no-reflow (group 3, n = 15). Regional wall motion in the chronic phase was depressed in groups 2 and 3 compared with group 1. The proportion of the area of the transmural infarction to that of the total infarction determined by scintigraphy was higher in groups 2 and 3 than in group 1. A significantly higher incidence of myocardial rupture and of death resulting from cardiac causes was observed in group 3 compared with group 1. The severity of this phenomenon immediately after an emergency PTCA correlated well with the severity of myocardial damage, with patients having severe no-reflow showing the poorest prognosis.

Adult↗
PubMed1995

The role of sodium in mediating adrenocorticotropin secretion by perifused rat anterior pituitary cells.

We studied the role of sodium ions in mediating basal and stimulated ACTH release from perifused rat anterior pituitary cells by exposing the cells to the sodium channel opener veratridine or the Na+/K(+)-adenosine triphosphatase inhibitor ouabain to increase the intracellular Na+ concentration or, conversely, by omitting Na+ from the perifusion medium or blocking Na+ entry into the cell with tetrodotoxin, a voltage-dependent sodium channel blocker, to decrease the intracellular Na+ concentration. Neither tetrodotoxin nor Na(+)-free medium had a significant effect on 100 nM arginine vasopressin (AVP) or 10 nM ovine corticotropin-releasing hormone (CRH)-induced ACTH secretion. Veratridine increased basal ACTH secretion by 122% (41.3 +/- 2.9 vs. 18.6 +/- 0.4 pg/min; P < 0.001), the initial spike phase of the response to AVP by 65% (0.28 +/- 0.01 vs. 0.17 +/- 0.03 ng/3 min; P < 0.005), the subsequent sustained phase to AVP by 129% (0.16 +/- 0.01 vs. 0.07 +/- 0.01 ng/7 min; P < 0.005), and the total response to CRH by 70% (0.39 +/- 0.01 vs. 0.23 +/- 0.04 ng/10 min; P < 0.05). Ouabain increased basal ACTH secretion by 39% (45.7 +/- 2.8 vs. 32.9 +/- 2.1 pg/min; P < 0.05), the initial spike phase of the response to AVP by 88% (0.32 +/- 0.02 vs. 0.17 +/- 0.01 ng/3 min; P < 0.005), the sustained phase response to AVP by 67% (0.10 +/- 0.01 vs. 0.06 +/- 0.01 ng/7 min; P < 0.05), and the total integrated response to CRH by 49% (0.88 +/- 0.09 vs. 0.59 +/- 0.03 ng/10 min; P < 0.05). However, the effects of both veratridine and ouabain on basal ACTH secretion were significantly attenuated in Ca(2+)-free EGTA-containing medium, suggesting that this effect was indirect, due to membrane depolarization and consequent influx of extracellular Ca2+. Dexamethasone (100 nM) had no effect on the ACTH response to either veratridine or ouabain. We conclude that changes in the intracellular Na+ concentration and sodium channel activity are not directly involved in AVP- or CRH-induced ACTH secretion.

Adrenocorticotropic Hormone↗
PubMed1995

[Progesterone].

Explore the source record for details and available documents.

Female↗
PubMed1994

Rare case with metastatic involvement of hypothalamo-pituitary and pineal body presenting as hypopituitarism and diabetes insipidus.

An unusual case with metastatic spread of a small oat cell lung carcinoma to the hypothalamo-pituitary region and pineal body presenting as pituitary insufficiency is reported. Computed tomographic scan revealed an isodense mass in the hypothalamo-pituitary region and pineal body that was strongly enhanced by contrast medium. Magnetic resonance imaging demonstrated a downward displacement of the posterior lobe of the pituitary by the hypothalamo-pituitary mass. Dynamic assessment of hypothalamo-pituitary function showed hypopituitarism and diabetes insipidus; partial recovery was observed with the improvement in the carcinoma by chemotherapy. The brain was subsequently irradiated. The patient survived 10 months.

Aged↗
PubMed1993

Alteration of hepatic enzyme activities in obese KK mice treated with monosodium aspartate.

Changes in body weight, concentrations of urine glucose, blood glucose, plasma insulin and FFA and hepatic enzyme activities were investigated in KK and C57BL mice treated with monosodium-L-aspartate (MSA). MSA was administered subcutaneously to neonates at a dose of 4 mg/g body weight. The MSA-treated KK and C57BL mice were remarkably obese at 10 weeks of age. The average plasma insulin concentration in the control KK mice was 73.6 microU/ml, over 4 times higher than in the control C57BL mice. In the control KK mice, hepatic glucokinase (GK) activity was quite low, and fructose-1,6-bisphosphatase (FBP) and acetyl-CoA carboxylase (CBX) activity was much higher than in the control C57BL mice. In the MSA-treated KK and C57BL mice, the plasma insulin concentration increased to 2 to 3 times higher than in the controls. The MSA-treated C57BL mice showed an increase in GK and CBX activity and acceleration of obesity. In the MSA-treated KK mice, GK activity did not change and CBX activity decreased, and only FBP activity increased significantly. Glycosuria was induced and blood glucose and plasma FFA increased remarkably in all MSA-treated KK mice.

Acetyl-CoA Carboxylase↗
PubMed1993

Testosterone normalizes plasma vasopressin response to osmotic stimuli in men with hypogonadism.

We studied plasma vasopressin concentrations during hypertonic saline infusions in 5 men with hypogonadism and 10 normal men to investigate the effect of gonadal steroid on hypothalamo-neurohypophyseal function. All the subjects received the infusion of 5% saline, and plasma vasopressin concentrations were determined by radioimmunoassay (RIA). Three of the 5 men were patients with isolated hypogonadotropic hypogonadism (IHH) and the other two were patients with Klinefelter's syndrome. None of them had any symptoms of diabetes insipidus. Although there was no difference between basal plasma osmolality in the patients and the normal subjects (287.2 +/- 2.1 vs. 285.3 +/- 1.8 mmol/kg), the basal level of plasma vasopressin in the patients was lower than that in the normal subjects (0.62 +/- 0.17 vs. 1.36 +/- 0.15 pg/ml, P < 0.05). Hypertonic saline infusion revealed varying degrees of subnormal vasopressin responses in the patients except one patient with Klinefelter's syndrome. The mean vasopressin response to osmotic stimuli (delta plasma vasopressin/delta plasma osmolality) in the 5 patients was lower than in the normal subjects (0.04 +/- 0.01 vs. 0.16 +/- 0.02, P < 0.05). Three patients with IHH and one patient with Klinefelter's syndrome were re-examined after pulsatile gonadotropin-releasing hormone (GnRH) infusion or testosterone enanthate i.m. injection. After the treatment with testosterone or GnRH, the response of plasma vasopressin to hypertonic saline infusion was normalized in three patients who had subnormal vasopressin response before treatment (delta plasma vasopressin/delta plasma osmolality: 0.04 +/- 0.01 vs. 0.09 +/- 0.01, P < 0.05). These results suggest that testosterone improves the subnormal vasopressin response to osmotic stimuli in men with hypogonadism.

Adolescent↗
PubMed1993

[Medical management after pituitary surgery].

Although the majority of patients with pituitary tumor, undergoing transsphenoidal microsurgery, have a low incidence of hormonal deficiency after surgery, the endocrinological evaluations should be carefully done before and after surgery. Glucocorticoid replacement is necessary in patients with Cushing's disease during and after surgery as well as those with adrenal insufficiency. Repeated CRF test is useful to assess the secondary adrenal insufficiency of Cushing's disease after surgery. Patients with impaired secretion of both ACTH and TSH should receive glucocorticoid replacement before thyroid hormone replacement in order to avoid adrenal crisis. A combination of CRF, GRF, TRH and GnRH is a safer and more reliable test to evaluate pituitary function than the conventional triple test consisting of insulin, TRH and GnRH, especially in patients predicted to have pituitary-adrenal insufficiency. Diabetes insipidus(DI), immediately after pituitary surgery, should be treated with subcutaneous injection of Pitressin. Even if patients seem to have recovered from DI several days after surgery, they must be monitored closely because of the incidence of triphasic DI. Less attention has been given to replacement for GH deficiency in adults. Recent reports revealed that GH replacement in adults with GH deficiency decreases visceral fat tissue and increases plasma calcium, phosphorus, osteocalcin and procollagen III levels. GH replacement will become more popular even in adults. Many options and technological advantages in the diagnosis and treatment of pituitary tumors have developed in a decade. In the near future, post-operative patients with pituitary tumors must be cared for in view of the "quality of life".

Adenoma↗