PubMed Health⌕ Search

Biomedical subjects

R Otsuka

Publications and source records attributed to R Otsuka.

At least 37 records · Page 2Linked to original sources
PubMed1994

Application of hydroxyapatite-sol as drug carrier.

The application of hydroxyapatite-sol as a drug carrier is being developed. Hydroxyapatite-sol which is a suspension consisting of hydroxyapatite nano-crystals, was synthesized using an ultrasonic homogenizer. The size of the crystals was 40 x 15 x 10 mm3 on average and their specific surface area was 100 m2/g. An amount of a glycoside antibiotics adsorbed onto hydroxyapatite nano-crystals was measured. The drug adsorbed 0.2 mg per 1 mg of hydroxyapatite. The affect of the drug adsorbed onto the hydroxyapatite was investigated using cancer cells. The drug, adsorbed onto the hydroxyapatite nano-crystals, inhibited cancer cell growth.

Adsorption↗
PubMed1989

[Usefulness of dual-energy digital radiography in detecting atlas and axis].

Cranial dual-energy digital radiography was applied to three patients. The anatomy of the atlas and axis was clearly recognized without utilizing the open-mouth view. We consider it a very effective technique when applied to the patient who experiences difficulty in opening the mouth, like severe traumatic or infantile patients. In addition, it is a useful examination for patients with suspected anomalies of cranio-vertebral junction.

Axis, Cervical Vertebra↗
PubMed1988

Provocation of a paradoxical growth hormone response to corticotropin-releasing hormone by pretreatment with metoclopramide in patients with acromegaly and normal subjects.

Two of 7 patients with acromegaly and one of 7 normal subjects exhibited a paradoxical rise in growth hormone (GH) to human corticotropin-releasing hormone (CRH) when pretreated with metoclopramide, although CRH alone did not induce an increase in GH. In one of these two patients with acromegaly, the GH increase to metoclopramide alone also reached the criteria of a paradoxical response. These two acromegalic patients showed a GH increase to metoclopramide pretreatment before and up to two months after surgery. In another acromegalic patient, whose GH level remained high 5 months after surgery, metoclopramide induced an increase in GH level, while in a patient who had an above-normal GH level 18 months after surgery, the resumption of physiological GH secretion after surgery was evidenced by a postoperative absence of a GH response to metoclopramide. It is suggested from these results that the GH response to metoclopramide and the metoclopramide-provoked GH response to CRH in patients with acromegaly result from the secretion of GH from nonadenomatous cells of the pituitary.

Acromegaly↗
PubMed1987

Pituitary-adrenocortical response to metoclopramide in patients with acromegaly and prolactinoma: a clinical evaluation of catecholamine-mediated adrenocorticotropin secretion.

We have demonstrated that metoclopramide stimulates cortisol secretion at least in part by a stress-mediated effect in normal men. To examine further the effect of the drug on the hypothalamo-pituitary adrenal system, we studied the cortisol response to 20 mg metoclopramide in patients with acromegaly, prolactinomas, and functional hyperprolactinemia and compared the results with the responses to insulin-induced hypoglycemia. In some patients, the effects of metoclopramide on CRH-induced ACTH and cortisol increase were studied to determine whether a change in dopaminergic (catecholaminergic) activity altered CRH stimulation of pituitary-adrenal function. No cortisol response to 20 mg metoclopramide occurred in 13 tests on 8 of 9 patients with prolactinoma or acromegaly with hyperprolactinemia, whereas both acromegalic patients without hyperprolactinemia had a response. All of the patients had a normal cortisol response to insulin-induced hypoglycemia. Pretreatment with metoclopramide enhanced the CRH-induced cortisol increase from 30-120 min after CRH in normal men, but only at 15 and 30 min in 5 agromegalic patients. The results suggest that metoclopramide acts in the hypothalamus to release ACTH through a dopamine antagonist-mediated (catecholaminergic) mechanism, and that metoclopramide may act additively with CRH to stimulate ACTH secretion in normal men. The absence of a metoclopramide-induced cortisol response in patients with acromegaly or prolactinomas and the absence of a normal cortisol response to metoclopramide-CRH in acromegalic patients could be due to endogenous catecholamine deficiency in these patients.

Acromegaly↗
PubMed1987

[Clinical significance of beta 2-microglobulin and carcinoembryonic antigen in intracranial tumors].

Beta 2-microglobulin (beta 2-MG) levels were determined in serum, cerebrospinal fluid (CSF), and tumor cyst fluid obtained from patients with a variety of intracranial tumors. In addition, a simultaneous determination of the carcinoembryonic antigen (CEA) was carried out in some patients. The beta 2-MG levels were elevated in 11/101 intracranial tumors, including glioma (4/34), non-glial tumors (1/18), malignant lymphoma (2/18), and metastatic brain tumors (4/31). There were no significant differences in the beta 2-MG levels of serum among the different patient groups. On the other hand, the beta 2-MG levels in CSF were significantly higher in patients with malignant lymphoma and metastatic brain tumors than in those with glioma and non-glial tumors. Fifteen (83.3%) of 18 patients with malignant lymphoma and 6(25.0%) of 24 patients with metastatic brain tumors showed increased the levels of beta 2-MG in CSF. The beta 2-MG levels in the tumor cyst fluid of 11 intracranial tumors exceeded normal serum levels in all but two patients. When the CEA levels in the serum and CSF were measured simultaneously, meaningful differences between malignant lymphoma and metastatic brain tumors were clearly observed. The highest incidence and highest levels of the CEA in serum and CSF were only noted in patients with metastatic brain tumors. Conversely, the serum CEA was slightly raised in 11.8% of malignant lymphoma and the levels of CEA in CSF were within normal range in all these patients. Serial determination of CSF beta 2-MG in patients with malignant lymphoma correlated well with their clinical findings.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Neoplasms↗