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Biomedical subjects

A Kuwayama

Publications and source records attributed to A Kuwayama.

At least 19 recordsLinked to original sources
PubMed1992

Endocrinological evaluation of ACTH-secreting pituitary microadenomas: their location and alpha-melanocyte stimulating hormone immunoreactivity.

It has been hypothesized by Lamberts and coworkers in their analysis of 15 cases that adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas may be derived from either the anterior lobe or the intermediate lobe. The intermediate lobe type of Cushing's disease is thought to be controlled through a hypothalamic pathway and is characterized by hyperprolactinemia; suppressibility of cortisol with bromocriptine, and lower sensitivity to dexamethasone. The authors investigated the validity of this hypothesis in 125 cases of ACTH-secreting pituitary microadenomas by analyzing the endocrine findings, the locations of the microadenomas, and alpha-melanocyte stimulating hormone (alpha-MSH) immunoreactivity in the adenoma cells. No significant differences in the basal hormone levels, cortisol suppressibility with bromocriptine, sensitivity to dexamethasone, and recurrence rate were observed between patients with the microadenoma adjacent to the posterior lobe (considered typical of the intermediate lobe-derived tumor) or those with the microadenoma located in the anterior lobe. The locations of the microadenoma were not correlated with alpha-MSH immunoreactivity in the adenoma cells. No significant differences in endocrine findings were noticed between adenomas positive or negative for alpha-MSH. Thus, Cushing's disease cannot be simply divided into either the anterior lobe type or the intermediate lobe type by endocrinological evaluation as described by Lamberts, et al.

Adenoma↗
PubMed1991

[Non-Hodgkin's lymphoma of the nasal cavity and paranasal sinuses: clinicopathologic study of ten cases].

Ten patients with non-Hodgkin's lymphoma originated in the nasal cavity (four patients) and in the paranasal sinuses (six patients) were treated mainly with irradiation and combination chemotherapy including adriamycin. According to the TNM AJC staging system, four patients were in stage T1-T2, and six patients were in stage T3-T4. Nine patients, other than one with stage IV (Ann Arbor) disease, achieved complete remission. Death due to lymphoma occurred in four patients, 4 to 39 months following diagnosis. Three of these patients developed systemic extranodal dissemination, and died in a short time after relapse. Death due to second malignancies occurred in two patients. One died of acute myelogenous leukemia, and the other died of colon cancer, 26 and 53 months after diagnosis, respectively. Four patients were alive and disease-free, from 23 to 68 months following diagnosis (median 40 months). Out of four patients who died of disease, three were in stage T3-T4, and one was in stage T1. Two patients with stage T1 originated in the nasal cavity were both alive and disease-free. Except for lymphomas with stage T1 originated in the nasal cavity, more intensive chemotherapy should be instituted in an attempt to achieve better disease-free survival.

Adult↗
PubMed1990

Pro-opiomelanocortin gene expression in silent corticotroph-cell adenoma and Cushing's disease.

The silent corticotroph-cell adenoma (SCCA) is characterized by the presence of immunoreactive adrenocorticotropic hormone (ACTH) in the tumor tissue in patients without symptoms of Cushing's disease. To elucidate the pathophysiology of SCCA, the expression of pro-opiomelanocortin (a ACTH precursor) genes was studied in a patient with SCCA and in three patients with Cushing's disease. Pro-opiomelanocortin messenger ribonucleic acid (mRNA) was found in the SCCA tissue to a greater degree than in the adenomas of the patients with Cushing's disease. Northern blot analysis revealed that the size of pro-opiomelanocortin mRNA present in the SCCA tissue was indistinguishable from that in the adenomas associated with Cushing's disease. A ribonuclease mapping study indicated that there were no point mutations in the coding sequence of pro-opiomelanocortin mRNA present in the SCCA tissue. Because of the presence of pro-opiomelanocortin mRNA and immunoreactive ACTH in the adenoma tissue, it is proposed that translation of the mRNA and subsequent accumulation of ACTH precursor occurred in the SCCA. Thus, the absence of Cushing's disease symptoms in this SCCA could not be caused by abnormality in the coding sequence of the pro-opiomelanocortin gene or in ribonucleic acid processing. The occurrence of abnormality at or after the translational steps was strongly suggested.

Adenoma↗
PubMed1990

Prolactin gene expression in human growth hormone-secreting pituitary adenomas.

To elucidate the mechanism of hyperprolactinemia often observed in patients with growth hormone (GH)-secreting pituitary adenomas, the presence of immunoreactive prolactin (ir-PRL) and prolactin (PRL) messenger ribonucleic acid (mRNA) in the tumor tissue was examined by immunohistochemistry and cytoplasmic dot hybridization. Hyperprolactinemia was observed in three of 18 patients with GH-secreting adenoma. The tumor tissue was demonstrated to contain ir-PRL in nine patients and PRL mRNA in 13. The presence of ir-PRL in the tumor tissue was always associated with positive PRL mRNA, indicating production of PRL in GH-secreting tumors. Among the three patients with hyperprolactinemia, both ir-PRL and PRL mRNA was revealed in the tumor tissue of one, PRL mRNA but not ir-PRL was detected in the adenoma tissue of another, and neither PRL mRNA nor ir-PRL was found in the tumor tissue of the third. The association of hyperprolactinemia with the presence of both ir-PRL and PRL mRNA or PRL mRNA alone is indicative of PRL production and secretion. However, the absence of ir-PRL and PRL mRNA in the tumor tissue may indicate that hyperprolactinemia is caused by the suppression of PRL inhibitory factor due to hypothalamic dysfunction by the tumor mass. Thus, the study of PRL gene expression and immunohistochemistry in GH-secreting adenomas is valuable to understanding the pathophysiology of pituitary tumors.

Adenoma↗
PubMed1989

Elevation of plasma atrial natriuretic peptide in a neurosurgical patient with the syndrome of inappropriate secretion of antidiuretic hormone--case report.

The authors describe a case of subarachnoid hemorrhage with hyponatremia accompanied by elevation of plasma atrial natriuretic peptide (ANP). The early phase of hyponatremia was classified as the syndrome of inappropriate secretion of antidiuretic hormone (ADH) due to subarachnoid hemorrhage. However, in the later phase, hyponatremia and natriuresis were accompanied by suppression of ADH while plasma ANP remained elevated. The patient was effectively treated with demeclocycline and hypertonic saline. The significance of ANP in the pathophysiology of increased natriuresis is discussed.

Aged↗
PubMed1989

[Chronic T-cell lymphoproliferative disorder associated with pure red cell aplasia].

A 42-year-old woman was admitted to our hospital because of easy fatigability in Jan. 1976. Laboratory examination revealed severe macrocytic anemia and slight lymphocytosis. She was diagnosed as having pure red cell aplasia (PRCA). She went into hematological remission 6 weeks following 40 mg/day treatment with prednisolone, but the anemia relapsed frequently when the dosage was lessened. She was then treated with 50 mg/day of cyclophosphamide, 50 mg/day of azathioprine, splenectomy, and methylprednisolone pulse therapy, but the recovery from anemia was temporary after each treatment. Since 1984, peripheral lymphocyte counts were 1-30,000/microliters, and reticulocyte counts were 0. She died of sepsis of Listeria in Sep. 1986. Peripheral lymphocytes had large azurophilic granules and an immunophenotype of OKT3+8+11+Ia1+Leu7+.

Adult↗
PubMed1988

[Changes of growth hormone-releasing factor (GRF) in rat peripheral blood--effect of hypophysectomy].

Accumulating evidence has emerged indicating that growth hormone-releasing factor (GRF) is present not only in the hypothalamus but in other tissues as well. Using highly specific and sensitive radioimmunoassays and immunoaffinity chromatography, we found low but clearly measurable GRF-like immunoreactivity (GRF-LI) levels in rat peripheral plasma. In order to verify the immunological findings, the peripheral plasma GRF-LI was characterized using fast protein liquid chromatography. The immunological peak was eluted at the position of synthetic rat GRF standard. These findings demonstrate that rat peripheral plasma GRF is immunologically and chromatographically indistinguishable from authentic rat GRF. Moreover, we performed studies with hypophysectomy to assess whether peripheral plasma GRF-LI changes in physiological status. At 4 weeks after hypophysectomy, there was a significant (p less than 0.05) increment in the rat plasma GRF-LI [12.4 +/- 0.5 (+/- SEM) pg/ml in hypophysectomized rats as opposed to 5.8 +/- 0.4 pg/ml in sham-operated control rars]. On the other hand, hypothalamic GRF-LI fell significantly as compared that of controls (36.1 +/- 1.0 vs. 78.3 +/- 3.0 pg/mg wet weight tissue). A similar pattern of changes in GRF-LI at 10 weeks after hypophysectomy was also revealed. The source of rat peripheral plasma GRF has not yet been elucidated. Our results, however, may suggest that GRF levels are modulated by negative feedback at the level of the hypothalamus by a pituitary factor, presumably growth hormone (GH) and that hypothalamic GRF release exceeds its synthesis in hypophysectomized rats.

Animals↗
PubMed1988

Disseminated intravascular coagulation accompanying thoracic and abdominal aortic aneurysm; report of three cases.

We reported three patients who developed disseminated intravascular coagulation (DIC) accompanying thoracic and abdominal aortic aneurysm. The first case, a 26-year-old man with dissecting aortic aneurysm developed DIC with clinical bleeding after operating on glaucoma. The administration of fibrinogen concentrates and antifibrinolytic agent made his DIC improve. The second case, a 70-year-old man with abdominal aortic aneurysm developed DIC showing large ecchymosis after angiography. His DIC disappeared after operation on aneurysm. The third case, a 73-year-old woman with thoracic and abdominal aneurysm developed laboratory-DIC without severe hemorrhagic diathesis. During antifibrinolytic therapy, platelet count, fibrinogen and fibrinogen degradation product (FDP) level improved. Since the treatment of the coagulopathy might be varied in the situation of the cause and clinical course, it is noted that anti-fibrinolytic therapy was effective in our two cases.

Adult↗
PubMed1988

Detection of mRNA of prolactin and ACTH in clinically nonfunctioning pituitary adenomas.

Clinically nonfunctioning pituitary adenomas have been thought to synthesize some pituitary hormones as shown by studies involving cell culture, immunocytochemistry, or measurement of hormone levels in tumor homogenates. Nevertheless, they are not associated with hypersecretion of pituitary hormones. To further clarify hormone synthesis in such pituitary adenomas, the presence of messenger ribonucleic acid (mRNA) of prolactin (PRL) growth hormone, and adrenocorticotropic hormone (ACTH) in the cytoplasm of 16 nonfunctioning adenomas was determined by means of a hybridization technique, and compared to the immunocytochemical findings. In three adenomas (19%) PRL mRNA was detected and in one case (6%) ACTH mRNA was detected. The hybridization technique appears to be more sensitive than immunohistochemistry for detection of specific mRNA's in assigning the hormone synthesis potential to clinically nonfunctioning tumors. The results suggest that PRL and ACTH are synthesized in some cases of clinically nonfunctioning pituitary adenomas and that hybridization techniques are useful to investigate hormone synthesis in pituitary adenomas. The ability to demonstrate PRL mRNA in tumor tissues allowed differentiation between hyperprolactinemia caused by synthesis of PRL in the tumor and that due to hypersecretion from the adjacent normal pituitary.

Adenoma↗
PubMed1987

[Inhibitory effect of ergot alkaloids on nucleosides transport in cultured bovine anterior pituitary cells].

Effect of ergot alkaloids on (3H)-nucleosides uptake by dispersed cells from fresh female bovine anterior pituitary glands was examined, because we had interested in the mechanism of pituitary tumor regression following bromocriptine treatment and considered nucleic acid synthesis as an important process in the metabolism of these cells. The anterior pituitary cells were implanted on culture tubes using D-valine minimal essential medium with serum to suppress the overgrowth of fibroblasts and then maintained in L-valine Dulbecco's modified Eagle medium. (3H)-Uridine uptake by these cells was suppressed by bromocriptine, at-ergocriptine or ergotamine at a concentration varing from 10(-6) M to 10(-5) M, but not 10(-5) M of lergotrile. Among these alkaloids, bromocriptine had most strong inhibitory effect and suppressed the uptake to below 25% of control value at the concentration of 10(-5) M. Bromocriptine also inhibited the uptake of (3H)-thymidine, (3H)-cytidine, (3H)-adenosine or (3H)-guanosine in the same manner as (3H)-uridine. But neither (3H)-uracil, the base of uridine, nor (3H)-galactose uptake by cells was affected by bromocriptine. The incorporation of (3H)-uridine or (3H)-thymidine into TCA-insoluble fraction of the cells was also inhibited by bromocriptine as that in the total cells. It was suspected that bromocriptine acted on distinct transport site of both ribonucleoside and deoxyribonucleoside, because a high concentration (3.3 X 10(-5) M) of radio-inactive thymidine did not modify (3H)-uridine uptake by these cells as well as inhibitory effect of bromocriptine on it. These effect of bromocriptine were not blocked by haloperidol, known as dopamine antagonist, at the same concentration as bromocriptine, and dopamine had no effect on (3H)-uridine uptake by the cells. In addition, by adding 5 X 10(-4) M of dibutyryl cyclic AMP into the medium, the effect of bromocriptine was also not affected. These data suggest that the effect of bromocriptine on nucleoside transport in anterior pituitary cells may be dependent on the other binding site than D-2 dopamine receptor in the anterior pituitary cell membrane.

Animals↗
PubMed1987

Long term results of transsphenoidal adenomectomy in patients with Cushing's disease.

As part of an ongoing series, 100 patients with Cushing's disease underwent transsphenoidal operations. Pituitary adenomas were confirmed in 93 patients, and initial remission was achieved in 86 (92%) of them. Hypercortisolemia was not corrected in 7 patients, and in 4 this was due to invasive adenomas. These patients were subjected to irradiation, medical treatment, or both after operation. Only 7 of the 100 patients had no pituitary adenoma found at operation, and they obtained no clinical remission even after partial or subtotal hypophysectomy. Follow-up review, with an emphasis on endocrinological studies, was performed on these patients for a mean period of 38 months. Seventy-eight patients were in long term remission after operation and had restoration of noncorticotropic hormone secretion as well as pituitary-adrenal function. Recurrence was noted in 8 patients after 19 to 82 months in remission. In all of these patients, pituitary adenomas were verified by reoperation and no case of corticotrophic cell hyperplasia was noted. We conclude that late recurrence of Cushing's disease may occur after adenoma removal and is due to the regrowth of adenoma cells left behind in the peritumoral tissue at the first operation. In view of the overall remission rate, transsphenoidal adenomectomy is considered a highly effective treatment for Cushing's disease.

Adenoma↗
PubMed1987

[Hyponatremia with high plasma ANP level--report of two cases with emphasis on the pathophysiology of cerebral salt wasting].

Two cases of hyponatremia with intracranial lesions are reported with emphasis on diagnostic value of measurement of antidiuretic hormone (ADH) and atrial natriuretic polypeptide (ANP). Case 1. A 77-year-old female was transferred to our hospital for further care of vegetative state after subarachnoid bleeding on May 23, 1986. She was operated by neck clipping of rt-IC bifurcation aneurysm and lt-internal carotid-posterior communicating aneurysm at another hospital. On admission, computed tomography showed diffuse low density at bilateral thalamus and centrum semiovale. Biochemical analysis revealed hyponatremia (120 mEq/t) with increased natriuresis. Endocrinological date revealed normal plasma ADH and high plasma ANP levels. Patient was treated with infusion of 1% NaCl. Case 2. A 65-year-old male was admitted to our department because of gradual impairment of consciousness and generalized convulsion. Computed tomography showed small low density area at rt-thalamus and lt-cerebellar hemisphere. Biochemical date revealed severe hyponatremia (91 mEq/t) with normal plasma level of ADH and high plasma ANP. He was treated with infusion of 3% NaCl and hyponatremia was improved. The hyponatremia is frequently associated with intracranial disorders such as brain tumor, subarachnoid hemorrhage and head injury. Originally, hyponatremia with natriuresis was thought to be caused by salt wasting. This syndrome was defined as the inability to prevent salt loss in the urine due to undefined natriuretic factor in the brain. However, since 1957, because of introduction of concept of SIADH, it has generally become accepted that patients with natriuresis had SIADH. (ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1986

[Histological changes and operative findings of pituitary adenomas after bromocriptine treatment].

Twenty-eight patients with various types of pituitary adenomas were studied endocrinologically and neuroradiologically. We observed the changes of tumor size during bromocriptine treatment. After various periods of bromocriptine therapy, we operated on these tumors and examined then histologically. One of 5 patients with nonfunctioning adenomas improved remarkably in his visual field and acuity after 7-month bromocriptine therapy. The pathological findings disclosed remarkable changes in tumors composed of shrunken island-like cell nests and acellular spaces. These shrunken island-like cell nests were composed of tumor cells whose cytoplasmic volume decreased and whose nuclear chromatin clumped. In acellular spaces, there were irreversibly destructed tumor cells, hyaline substances, tumor cell debris and collagen fibrils. One of 8 cases of acromegalies showed a remarkably reduced tumor on CT with clinical improvement after treatment with bromocriptine for 10 months. This patient's serum growth hormone titer was raised by an abnormal response to intravenously injected TRH (thyrotropin releasing hormone), and his serum prolactin was abnormally high. Therefore, this tumor was thought to be a mixed adenoma with growth hormone secreting and/or prolactin secreting cells. Histological examinations disclosed cell shrinkage of tumor cells. Interestingly, there were scanty fibrotic changes in this tumor in spite of the long term bromocriptine therapy. In 15 cases of prolactinomas, the larger the tumor size and the longer the period of the bromocriptine therapy, the more fibrosis was seen. Under a period of bromocriptine therapy longer than 3 months, the fibrotic changes of tumor progressed, and this made more difficulty in selective adenomectomy even in the case of intrasellar adenomas. Therefore we thought that transsphenoidal surgery could successfully be done within 3 months during continuation of bromocriptine therapy.

Acromegaly↗
PubMed1986

Effect of estrogen on prolactin mRNA in the rat pituitary. Analysis by in situ hybridization and immunohistochemistry.

The effect of estrogen on prolactin (PRL) synthesis at a single-cell level was studied by in situ hybridization and immunohistochemistry. Long-term estrogen treatment increased PRL-containing cells from 10-20% of total cell population to 80-90%, as revealed by immunohistochemistry. PRL mRNA containing cells also increased in a similar fashion. Moreover, cytoplasmic PRL mRNA expressed as the number of silver grains per cell increased 4- to 5-fold by estrogen. These results suggest that long-term estrogen treatment causes not only PRL cell proliferation but also an increase in PRL mRNA in a single cell.

Animals↗
PubMed1985

Diagnosis, treatment and postoperative results of Cushing's disease.

One hundred patients with Cushing's disease were operated on in Nagoya University Hospital between January 1977 and January 1984. Pituitary adenomas were found and resected in 93 cases and complete clinical remissions were observed in 89 treated by operation alone and in two additional cases by operation followed with radiotherapy. The clinical features, pre-operative endocrine data, radiological findings including high resolution CT with coronal and sagittal reconstructions, data of selective venous sampling, operative findings, tumour pathology, postoperative clinical course, postoperative endocrine results and follow-up findings are presented and discussed.

Adenoma, Basophil↗