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Biomedical subjects

A Kuwayama

Publications and source records attributed to A Kuwayama.

At least 55 records · Page 3Linked to original sources
PubMed1985

[ACTH dependent Cushing's syndrome with an empty sella turcica: report of three cases with emphasis on diagnostic value of selective venous sampling].

Three cases of ACTH dependent Cushing's syndrome are reported with emphasis on diagnostic value of selective venous sampling. Case 1. A 44-year-old female was admitted to our hospital with clinical diagnosis of Cushing's disease. Endocrinological examination revealed typical data of Cushing's disease. High resolution CT scan showed an empty sella turcica, and a chest film showed multi-cystic lesion in the left lower lung field. In the first trial of selective venous sampling, central to peripheral ACTH ratio (C/P ratio) was high at the superior vena cava. So, an ectopic ACTH producing lung tumor was strongly suspected. Further examinations for lung tumor were performed, and finally showed lung cryptococcosis. Therefore, selective venous sampling was performed again, and pituitary ACTH dependency was diagnosed. An eccentric pituitary microadenoma was successfully removed by transsphenoidal surgery. Case 2. A 54-year-old female was admitted to our hospital with clinical diagnosis of Cushing's disease. In the endocrinological examinations plasma ACTH was not respond to provocation of LVP or CRF. In selective venous sampling, C/P ratios of ACTH were not greater than 2.0 at any sampling site. Further examinations showed lung tumor in the lower lobe of left lung. This tumor was surgically proved to be an ectopic ACTH producing lung carcinoid. Case 3. A 24-year-old female was admitted to our hospital for the purpose of further examination of Cushing's disease. Three years previously exploratory transsphenoidal surgery demonstrated an empty sella without adenoma. She received postoperative radiation therapy with a dose of 5000 rad. Endocrinological examination showed typical data due to Cushing's disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1984

[Corticotropin-releasing factor concentrations in cerebrospinal fluid and its diurnal rhythm in patients with Cushing's disease].

Since Vale et al isolated and sequenced a 41 amino acid peptide with corticotropin-releasing factor (CRF) activity from ovine hypothalami, intensive works have been done about its physiological activity and intracerebral distribution. However, little has been done yet about CRF metabolism in human cerebrospinal fluid (CSF). Using a specific ovine CRF radioimmunoassay (RIA), we measured the levels of CRF in CSF from 16 patients with Cushing's disease (group I), 8 patients with Acromegaly (group II), 5 patients with Prolactinoma (group III) and 10 patients without endocrine abnormalities (group IV). Moreover diurnal changes of CRF in CSF from 2 patients with Acromegaly and 2 patients with Cushing's disease were examined. Dilution curves of CRF in CSF were parallel to that of synthetic ovine CRF standard. The intraassay coefficient of variation was 9.2% and the interassay coefficient of variation 12.6%. The concentrations of CRF in CSF of groups I, II, III and IV were 38.83 +/- 9.02 pg/ml (mean +/- SD), 44.24 +/- 4.71, 47.62 +/- 8.05 and 49.45 +/- 12.86, respectively. Group I was significantly lower than group IV (p less than 0.05). On the other hand, group II or III was not significantly different from group IV. A diurnal rhythm of CRF in CSF was observed in 2 patients with Acromegaly. However, there was almost no change in the 2 patients with Cushing's disease. In considering rich amount of CRF in hypothalamus and CRF-positive fibers surrounding the third ventricle, CRF content in CSF seems to reflect mainly its metabolic activity in hypothalamus.(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly↗
PubMed1984

[Surgery in endocrine disorders. 1. Pituitary tumors].

Microsurgical refinement of classical transsphenoidal pituitary surgery facilitated selective adenomectomy with preservation of normal residual pituitary, thus becoming the first choice in the management of functioning pituitary adenomas. However, lack of tumor capsule and invasive nature of the adenoma make its total removal still difficult. Peritumoral wedge resection is most recommended from our experiences. Surgical results of acromegaly have become quite satisfactory and normal postoperative serum GH levels have been obtained in nearly 100% of the cases with micro or enclosed-adenoma. Pituitary irradiation and/or bromocriptine therapy are, however, yet necessary in half of the cases with marked suprasellar extension or invasion into the surrounding tissues. In the management of macroprolactinoma, surgical excision should precede bromocriptine therapy, because fibrous changes of the adenoma caused by the drug make surgical intervention much difficult. Microprolactinoma can be treated satisfactorily either by surgery or by bromocriptine. Just follow-up observation may be indicated to the cases having no hope for baby. All impaired pituitary functions in Cushing's disease can be converted normal by selective adenomectomy. However, highly qualified microsurgical technique and systematical survey for microadenoma are mandatory, otherwise it is often elusive.

Acromegaly↗
PubMed1984

[Size reduction of a nonfunctioning pituitary adenoma after bromocriptine therapy: case report].

Bromocriptine therapy may cause regression of prolactinomas and GH producing adenomas, but there is only few reports about the effect of bromocriptine against nonfunctioning pituitary adenomas and there is no reports about its histopathological changes. We report a nonfunctioning pituitary adenoma, which remarkably regressed during and following bromocriptine therapy. A 47-year-old man developed blurred vision on January 20, 1981. He was pointed out of bitemporal hemianopsia and of his left palor optic fundus. His endocrinological condition was panhypopituitarism and no hypersecreting hormones were found. Cranial computerized axial tomography showed huge dumbbell shaped high density mass extending from the enlarged intrasellar area to the floor of the third ventricle. On treatment with bromocriptine, 5 mg daily for 3 days, his visual acuity and field was remarkably improved. Treatment was continued with gradually increased doses of bromocriptine to 15 mg and so, remarkable shrinkage of tumor size about 50% was seen by computerized axial tomography by a month. In addition, by eight months, the tumor reduced to 22%. Transsphenoidal surgery revealed centrally necrotic tumor mass surrounded by peripheral fibrous one. Because of fibrous and hemorrhagic tumour, we could not remove it totally. The pathological specimen was examined by light and transmission electron microscopy. The tumor was diffuse-type chromophobe adenoma partially intersected by hypertrophied fibrous interstitial materials. Some tumor cells were stained faintly eosinophilic. The cytoplasms were shrunken and the tumor cells were clumped. The immunostaining of tumor was negative to all anterior pituitary hormones. The intracytoplasmic organellae, for example, rough endoplasmic reticulum, Golgi apparatus, were scanty but prominant deformed mitochondria and small secretary granules (the size of about 90-150 nm) were found by transmission electron microscope. We think that the tumor cells had various responsiveness to this drug and the one extreme was destruction of the nucleus, the irreversible change, and the other extreme was some cytoplasmic reduction, the reversible change. The histopathological changes were almost the same as those of prolactinomas treated with bromocriptine. In conclusion, the mechanism of shrinkage of nonfunctioning pituitary adenomas treated with bromocriptine is unclear but it is worth while treating inoperable or recurrent large nonfunctioning pituitary adenomas with bromocriptine.

Adenoma↗
PubMed1983

Pituitary adenomas that caused Cushing's disease or Nelson's syndrome are not responsive to ovine corticotropin-releasing factor in vitro.

The response of pituitary adenomas obtained surgically from patients with Cushing's disease of Nelson's syndrome to synthetic ovine corticotropin-releasing factor (CRF), vasopressins, somatostatin-28, dexamethasone, 3-isobutylmethylxanthine or high [K+] was examined in vitro by measuring the amount of pro-opiomelanocortin (POMC)-derived peptides secreted into the culture medium. CRF did not stimulate the secretion of adrenocorticotropin-, beta-endorphin-, or gamma 3-melanotropin-like peptides from the pituitary adenomas at concentrations ranging from 1 x 10(-13) M to 1 x 10(-7) M whereas vasopressins, 3-isobutyrl-methylxanthine and high [K+] increased, while somatostatin-28 and dexamethasone suppressed, the secretion of these POMC-derived peptides. These findings suggest that either the pituitary ACTH-producing tumors have lost their receptors to CRF or their post-receptor mechanism to CRF is not functional.

Adenoma↗
PubMed1983

Pituitary adenomas in acromegalic patients: an immunohistochemical and endocrinological study with special reference to prolactin-secreting adenoma.

To establish a functional classification of purification of pituitary adenomas in acromegalic patients, we used immunoperoxidase-staining techniques specific for GH and PRL. Surgical specimens from 55 acromegalic patients were studied. GH was demonstrated in all adenomas and PRL was found in 25 of them (45.5%). Immunohistologically, GH- and PRL-containing adenomas could be divided into 3 types. In type 1 (11 patients), immunoreactive PRL was present in single cells surrounded by immunoreactive GH cells. In type 2 (6 patients), immunoreactive PRL cells formed clusters. In Type 3 (8 patients), immunoreactive PRL and GH cells demonstrated a mosaic pattern, and it was difficult to determine which were in the majority. A double immunostaining method revealed 15 adenomas in which individual cells contained both GH and PRL. Hyperprolactinemia was present in 21 patients, 15 of these had immunoreactive PRL cells (type 1, 4 patients; type 2, 3 patients; type 3, 8 patients). There was no correlation between the size of the adenoma and its type. Endocrinologically, all patients with type 2 and 3 adenomas had an abnormal serum GH response to TRH administration; all type 3 patients had a substantial serum PRL response to TRH administration. Type 3 is considered to be an actively PRL-secreting adenoma, resulting in hyperprolactinemia.

Acromegaly↗
PubMed1983

Distribution, biosynthesis, and physiological role of corticotropin-releasing factor in the human: an overview.

Our findings to date indicate that: A peptide resembling oCRF is present in human and mammalian hypothalamus. oCRF is present in human lumbar cerebrospinal fluid. oCRF concentrations do not differ in CSF from normal individuals and from patients with Cushing's syndrome. oCRF appears to be synthesized via a large oligopeptide precursor. An oCRF-like molecule (oCRF-LI) is present in hypothalamic brain tissue. We have also observed more tentative evidence of low levels of oCRF-LI outside of the brain. oCRF is likely to be a central mediator of stress in its multiple forms. We believe that oCRF is clearly of major physiological importance, but that many critical unanswered questions remain. Probably, the most fascinating of these, which we are only beginning to comprehend, concerns the functions of CRF in extrahypothalamic brain as well as the CRF which appears to be present outside the brain.

Animals↗
PubMed1983

Successful pregnancies in patients with hyperprolactinemia--clinical and endocrinological studies on mothers and babies.

To study the effect of pregnancy and lactation on the clinical course of patients with pituitary adenoma and the influence of maternal hyperprolactinemia and bromocriptine treatment on fetal and neonatal development, prolactin levels were serially determined and abnormalities of newborn babies were examined. Ninety-nine patients with hyperprolactinemic amenorrhea were treated by surgery, bromocriptine therapy, and a combination of them; thus 34 patients conceived and gave birth to 43 babies. Almost all patients progressed uneventfully except for 2 cases who manifested diabetes insipidus and acute visual impairment. After the end of lactation, prolactin levels declined to lower values than before attempting pregnancy, except in 3 patients. Furthermore, those diagnosed as functional hyperprolactinemia before pregnancy were not found to have developed microadenoma. These results suggest that there is little influence on growth and activity of tumor throughout pregnancy and lactation. All of the newborns were normal and their growth up to 2 years after birth showed no special abnormalities. It was therefore concluded that maternal hyperprolactinemia or bromocriptine therapy in early pregnancy do not cause any deleterious effect on fetal and neonatal development.

Adenoma↗