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Biomedical subjects

Hajime Izumiyama

Publications and source records attributed to Hajime Izumiyama.

9 recordsLinked to original sources
PubMed2006

Subclinical Cushings disease with amelioration of metabolic comorbidities after removal of pituitary tumor.

A 49-year-old woman with hypertension, obesity and impaired glucose tolerance (IGT) was admitted for evaluation of pituitary incidentaloma. Although she presented no Cushingoid feature, endocrine examination of hypothalamo-pituitary-adrenal (HPA) axis showed elevated basal plasma ACTH and cortisol levels, their lack of circadian rhythm, non-suppressibility to low-dose (1 mg) dexamethasone, and responsiveness to CRH, suggesting autonomous ACTH secretion from a pituitary tumor. She underwent transsphenoidal surgery, and was diagnosed as chromophobe adenoma with positive ACTH immunoreactivity. Postoperatively, her abnormal HPA axis was resolved, along with improvement of hypertension, obesity and IGT. Thus, her metabolic comorbidities are likely due to subclinical Cushings disease.

Female↗
PubMed2006

A Case of acromegaly associated with subclinical Cushing's disease.

A 54-year-old man with type 2 diabetes was referred to our hospital for endocrine evaluation of acromegaly. Physical examination showed typical acromegalic features without Cushingoid features. Magnetic resonance imaging of the brain revealed the presence of a pituitary macroadenoma. Basal plasma levels of GH and insulin-like growth factor-I under fasting hyperglycemia (202 mg/dl) were markedly elevated. Plasma GH levels paradoxically increased after stimulation with TRH and LH-RH, and decreased after bromocriptine and octreotide administration. Endocrine examination of the hypothalamo-pituitary-adrenal (HPA) axis showed a lack of circadian rhythm of ACTH and cortisol, non-suppressibility to low-dose (1 mg), but suppressibility to high-dose (8 mg) dexamethasone, and normal response to CRH stimulation. The tumor resected by transsphenoidal surgery was histopathologically consistent with the diagnosis of eosinophilic adenoma: positive immunoreactivities of GH, PRL and ACTH were demonstrated, but negative immunoreactivities of prohormone convertase (PC) 1/3 by immunohistochemical method. After surgery, plasma GH and IGF-I levels decreased along with normalization of HPA axis. Metabolic co-morbidities such as diabetes and hypertension disappeared after removal of the pituitary tumor. This is a very rare case of GH-producing pituitary adenoma causing typical acromegaly with concomitant production of ACTH causing subclinical Cushing's disease.

Acromegaly↗
PubMed2006

A case of factitious adrenal insufficiency after vascular graft surgery caused by spurious immunometric assays.

A 70-year-old man with abdominal aortic aneurysm underwent surgical repair with Hemashield vascular graft. Postoperatively, he was found to have very low plasma cortisol levels, which failed to increase after stimulation with ACTH. A tentative diagnosis of adrenal insufficiency was made despite the lack of its clinical manifestations and a replacement therapy with hydrocortisone was started. He had also elevated plasma levels of TSH, thyroid hormones and estrogen without any clinical manifestations. Such abnormal hormone levels were spontaneously normalized three months after operation, which was later proven to be factitious by different immunometric assays (IMA). Since the vascular graft coated with bovine type I collagen has been reported to induce a transient immune response in some patients after surgery, we speculated that certain antibodies generated against heterologous collagen and/or yet-unknown components derived from the graft may have caused such factitious data; exogenous addition of bovine type I collagen and albumin to patient's serum, however, failed to affect the assay results. Whatever the cause, caution must be paid that some patients with surgical repair using heterologous materials may have such factitious hormone data by IMAs.

Adrenal Insufficiency↗
PubMed2006

Glucose-responsive and octreotide-sensitive insulinoma.

Insulinoma is the most common cause of fasting hypoglycemia resulting from autonomous insulin hypersecretion. We describe herein a unique case with paradoxical hypoglycemic episodes induced by hyperglycemia. A 55-year-old female had repeated hypoglycemic episodes after meal or during increased physical activity. Although fasting (10 hr) failed to provoke hypoglycemia, oral glucose tolerance test (GTT) caused an exaggerated insulin response (885 microU/ml) at 30 min, followed by hypoglycemia (36 mg/dl) after 90 min. Moreover, intravenous GTT also induced an exaggerated insulin response (>2900 microU/ml) at 10 min, followed by hypoglycemia (34 mg/dl) after 40 min. Although MRI and CT scan of the abdomen failed to detect any mass lesions in the pancreas, Octreoscan revealed increased radioactive uptake around the pancreatic head region. Treatment with a daily injection of octreotide (100 microg) alleviated her hypoglycemic episodes. At surgery, two islet cell adenomas were identified in the pancreas and resected. Postoperatively, she was free from hypoglycemic episodes after meal. Postoperative oral and intravenous GTT did not induce hypoglycemia. Thus, this is a very rare case of glucose-responsive and octreotide-sensitive insulinoma in whom GTT and octreotide proved to be a useful provocation and treatment for hypoglycemic episodes.

Antineoplastic Agents, Hormonal↗
PubMed2006

[Salusin].

Explore the source record for details and available documents.

Adenosine Triphosphatases↗
PubMed2005

Synthetic salusins as cardiac depressors in rat.

Using bioinformatic analyses of full-length, enriched human cDNA libraries, we recently identified salusins, multifunctional related peptides ubiquitously expressed in major human tissues. Salusins cause transient and profound hypotension when injected intravenously to rats, the hypotensive effect of salusin-beta being especially striking. However, the mechanisms of this hypotensive action remain elusive. To determine whether salusins modulate cardiac function in rats, we studied serial changes of systemic hemodynamics and functions of isolated perfused working and nonworking hearts before and after salusin administration. Intravenous salusin-beta administration to intact anesthetized rats caused a temporary rapid, profound decrease in aortic blood flow concomitantly with hypotension and bradycardia without affecting systemic vascular resistance. Salusin-beta-induced hypotension and bradycardia were completely blocked by pretreatment with atropine, a muscarinic receptor antagonist, but not by propranolol. In isolated perfused working rat hearts, salusin-beta significantly decreased cardiac output, aortic flow, and stroke work. However, it did not affect coronary flow in isolated working and nonworking hearts. Our results indicate that salusins induce potent hypotension via negative inotropic and chronotropic actions. Salusin-beta promotes its actions by facilitating vagal outflows to the heart, whereas the negative inotropism of salusin-beta is also mediated via a direct myotropic effect.

Adenosine Triphosphatases↗
PubMed2005

Malignant gastric carcinoid causing ectopic ACTH syndrome: discrepancy of plasma ACTH levels measured by different immunoradiometric assays.

Discrepancy of plasma ACTH levels measured by different immunoradiometric assays (IRMA) in a case with malignant gastric carcinoid causing ectopic ACTH syndrome was examined by gel chromatography and immunohistochemical analysis. A 49-year-old male was found to have a large gastric tumor, with muscle wasting, hypertension, diabetes and hypokalemia caused by hypercortisolemia. His plasma ACTH levels, although initially elevated, were found to be almost in normal ranges. The discrepancy of plasma ACTH levels was proven to be due to different IRMA kits used; the initial assay was performed by a kit that could recognize high-molecular weight (HMW) form as well as ACTH(1-39), but the later assay by another kit that could recognize only ACTH(1-39). Pathological examination of the gastric tumor was consistent with the diagnosis of malignant carcinoid. Immunohistochemical study revealed that immunoreactivity of proopiomelanocortin (POMC) was positive within the tumor cells, whereas those of ACTH and prohormone convertase 1/3 were negative. Molecular sieving analysis of patient's plasma by gel chromatography coupled with ACTH radioimmunoassay which could recognize HMW form and ACTH(1-39) and two different IRMAs revealed that the predominant form of ACTH was HMW form with a minor peak of ACTH(1-39). This is a rare case of ectopic ACTH syndrome caused by malignant gastric carcinoid with preferential production of HMW form of ACTH, possibly due to unprocessed POMC.

ACTH Syndrome, Ectopic↗
PubMed2005

Type 1 diabetes mellitus and drug-resistant epilepsy: presence of high titer of anti-glutamic acid decarboxylase autoantibodies in serum and cerebrospinal fluid.

A 55-year-old man who was diagnosed as having type 1 diabetes mellitus (DM) at the age of 50 years was started on insulin therapy. At 54 years old of age, he suddenly developed complex partial seizures, which frequently occurred despite intensive anti-epileptic drug therapy. Neurological examination on admission revealed hyporeflexia in bilateral upper and lower extremities without any muscle rigidity, painful spasm or cerebellar ataxia. Laboratory examination showed poor glycemic control with increased glycated hemoglobin levels. Positive anti-thyroglobulin antibodies and anti-thyroid peroxidase (TPO) antibodies and slight elevation of TSH levels are consistent with subclinical hypothyroidism due to Hashimoto's thyroiditis. A high titer of anti-glutamic acid decarboxylase (GAD) antibodies was detected in the patient's serum and cerebrospinal fluid (CSF). Electroencephalography showed temporal spikes, consistent with complex partial seizure. This is a very rare case presenting with concomitant type 1 diabetes and drug-resistant epilepsy associated with high titers of circulating and CSF anti-GAD antibodies.

Anticonvulsants↗