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Biomedical subjects

A Teramoto

Publications and source records attributed to A Teramoto.

At least 55 records · Page 3Linked to original sources
PubMed2001

[EDAS (encephalo-duro-arterio-synangiosis) for occlusive/stenotic cerebrovascular disease].

The efficacy of encephalo-duro-arterio-synangiosis (EDAS) using superficial temporal artery was evaluated for the treatment of the occlusive/stenotic cerebrovascular disease. Nine patients with the occlusive/stenotic cerebrovascular disease underwent EDAS in our hospital. The mean follow-up period was 6.6 months. Postoperative angiography showed no collateral formation via EDAS in any of the nine patients. We analyzed the following points: 1) operative procedure, 2) follow up period after surgery, 3) preoperative cerebral blood flow, and 4) age of the patients. Results showed that EDAS as a treatment of occlusive/stenotic cerebrovascular disease was not effective. This study failed to reinforce the suggestion that indirect extracranial/intracranial bypass surgery is effective as the treatment of occlusive/stenotic cerebrovascular disease.

Adult↗
PubMed2001

[Usefulness of multiphase helical CT in the diagnosis of pituitary microadenoma].

The purpose of this study was to determine the value of multiphase helical CT (MHCT) in the diagnosis of pituitary microadenoma. Twenty-two patients with clinically suspected microadenoma were examined. Coronal pre-contrast CT was initially carried out. Three series of helical scanning using 1-mm collimation, 1-mm/s table speed, and 1-mm interval reconstruction covering the entire pituitary gland were performed with an intravenous injection of contrast medium. Immediately after MHCT, delayed CECT was performed. Twenty microadenomas (3-10 mm, mean: 5.5 mm) were surgically confirmed. MHCT could depict all 20 tumors, while pre-contrast CT and delayed CECT showed 4 and 12 of 20 tumors, respectively. MHCT was useful in the diagnosis of pituitary microadenoma owing to its high spatial resolution and extensive coverage.

Adenoma↗
PubMed2001

[A case of iatrogenic carotid artery dissection treated with radial artery graft].

A case of iatrogenic intracranial artery dissection is reported. A 52-year-old female developed severe headache and nausea. Brain CT showed diffuse subarachnoid hemorrhage. On admission, carotid angiography revealed an aneurysm in the right middle cerebral artery and the intact right internal carotid artery. The aneurysm was clipped successfully. Carotid angiography on day 7 revealed dissection in the right internal carotid artery. Repeated angiograms at 10 and 31 days showed progression of the carotid artery dissection. Findings of ECD-SPECT on day 31 (Balloon occlusion test) suggested low perfusion of the right internal carotid artery territory. The patient underwent surgical reconstruction of the right internal carotid artery using a radial artery. She presented with right abducens nerve palsy three days after the radial artery graft. The patency of the radial artery graft was proved by the post-operative angiography. Internal carotid artery dissection may occur spontaneously or as a result of trauma. An iatrogenic dissection is an uncommon complication of cerebral angiography. There are no evidence-based guidelines for the treatment although anticoagulation therapy is most commonly used. The present case emphasizes the usefulness of radial artery graft for traumatic carotid artery dissection.

Carotid Artery, Internal↗
PubMed2001

[Dissecting aneurysm of the posterior inferior cerebellar artery--studied by serial angiography].

We report the case of a 34-year-old male with cerebellar hemorrhagic infarction caused by a dissecting aneurysm of the left posterior inferior cerebellar artery (PICA). The patient suffered from a headache and vomiting for two days and was transferred to our hospital with sudden deterioration of consciousness. On admission, he was semicomatose. A CT scan revealed hemorrhagic infarction in the left cerebellum and upward herniation. The emergency operation for posterior fossa decompression was performed. Postoperatively, his consciousness level improved promptly and he had no neurological deficits except for slight gait disturbance. The first vertebral angiography was performed on Day 27. It showed a sausage-like dissecting aneurysm of the left distal PICA. We planned conservative therapy with careful observation because of there being no indication for an operation. Serial angiography was performed and demonstrated the regression of the dissecting aneurysm on Day 258. Dissecting aneurysms of the distal PICA are rare and their natural history is not well understood. Conservative therapy for vertebrobasilar dissecting aneurysms has often been reported. We suggest that conservative therapy with serial angiography is the treatment of choice especially for ischemic-type dissecting aneurysms. We review 17 cases of dissecting aneurysm of the distal PICA in this study.

Adult↗
PubMed2000

Usefulness of niravoline, an arginine vasopressin inhibitor, on tumour-origin brain oedema.

Niravoline is a selective agonist of kappa-opioid receptors having potent aquaretic activity which may peripherally be mediated in animals. This effect of niravoline is thought to be due to inhibition of arginine vasopressin secretion. Niravoline does not cause an overt excretion of electrolytes that is seen with conventional diuretics, and it is anticipated that niravoline may prove useful in the treatment of oedema. In this study, effect of niravoline on tumour-origin brain oedema was investigated in a brain tumour model created by implantation of C6 glioma cells into the brains of Wistar rats. Five weeks after the tumour cell implantation, niravoline was administered i.v. at 1 mg/kg a total of four times at one-hour intervals. In the control group (i.e., saline or vehicle-treated rats), this brain tumour model was found to result in a statistically significant increase in the water content in selected brain regions remote from the tumour. Administration of niravoline inhibited the increase in the water content in such selected brain regions. Niravoline might be useful on tumour-origin brain oedema clinically.

Animals↗
PubMed2000

Multiple pituitary hormone gradients from cavernous sinus sampling in patients with Cushing's disease.

OBJECTIVE: Cavernous sinus sampling in patients with adreno-corticotropic-hormone (ACTH) secreting pituitary adenomas has been used to identify directly ACTH hypersecretion from the pituitary and to predict the lateralization of a microadenoma. In our previous series, cavernous sinus sampling provided a sufficient central/peripheral (c/p) ratio of ACTH and the correct laterality of the pituitary lesion in all microadenomas situated in the lateral wing. To clarify the diagnostic value of other anterior pituitary hormones in relation to ACTH gradients, we evaluated multiple pituitary hormone gradients between a cavernous sinus and a peripheral vein and between both cavernous sinuses in patients with Cushing's disease. METHODS: Cavernous sinus sampling was done in 11 patients with clinical and biochemical features of ACTH-dependent Cushing's syndrome. In 9, pituitary adenoma was detected during trans-sphenoidal surgery and histologically confirmed, while 2 others were suspected of having ectopic lesions. Serum ACTH, prolactin (PRL), thyroid stimulating hormone (TSH), growth hormone (GH), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) from catheters in both cavernous sinuses and from a peripheral vein were measured. The c/p ratios of each hormone and the intercavernous gradients were evaluated. RESULTS: The c/p ratio of ACTH indicated the presense of pituitary lesions in all 9 patients with ACTH-secreting microadenomas. In addition, the intercavernous gradients of ACTH indicated the correct localization of microadenomas in all 6 patients with lateralized lesions. As for other hormones, the c/p ratios of GH, PRL, TSH and LH were significantly high in number 7, 6, 6 and 3 patients, respectively. In contrast, the significant step up of FSH was observed only in one patient. The intercavernous gradients of GH and PRL were significantly high in number 5 and 4 patients, respectively. CONCLUSIONS: The intercavernous gradients of GH and PRL tend to indicate the lateralization of a microadenoma. The measurement of GH and PRL during cavernous sinus sampling may provide additional information, in the lateralization of ACTH-secreting microadenomas.

Adenoma↗
PubMed2000

A family with hydrocephalus as a complication of cerebellar hemangioblastoma: identification of Pro157Leu mutation in the VHL gene.

Various mutations in the VHL gene on chromosome 3p25-26 are responsible for von Hippel-Lindau (VHL) syndrome. We report on a Japanese VHL family in which two of the three affected members developed acute occlusive hydrocephalus that necessitated emergency surgery for ventricular shunt or drainage. Direct sequencing and restriction fragment length polymorphism analysis identified a germline missense mutation, Proline-to-Leucine, caused by a C-to-T transition at the second nucleotide of codon 157.

Acute Disease↗
PubMed2000

Microcapsulated parathyroid tissue in vitro.

Ideally, microcapsules will make it possible to transplant parathyroid tissue for allo- and xenotransplantation in hypoparathyroid patients. In this study, parathyroid tissues capsulated by polyelectrolyte complex were evaluated in vitro. Hormone secretion ability was significantly (P < 0.001) greater in sediment than in supernatant. There was no difference in hormone secretion ability between the parathyroid tissue thawed at room temperature and the tissue thawed in a bath at 37 degrees C. Both non-capsulated and capsulated parathyroid tissues were incubated for three weeks. The ability of capsulated parathyroid to secrete hormones in vitro was reduced gradually and disappeared within three weeks. There are still several problems to be solved before the clinical application of parathyroid allotransplantation using microcapsulation.

Cryopreservation↗
PubMed2000

Drug-induced apoptosis by anti-microtubule agent, estramustine phosphate on human malignant glioma cell line, U87MG; in vitro study.

The drug effect of estramustine phosphate (EMP), an anti-microtubule agent on human glioma cells has been studied with the focus being mainly its cytotoxity or its targeting of organelles. However, the pharmacological knowledge of estramustine with respect to its cytotoxity and mechanism is limited. To acquire such knowledge, the present study investigates the ability of EMP to induce apoptosis in a human malignant glioma cell line. Transmission electron microscope (TEM) images were examined to monitor periodic changes. Agarose gel electrophoresis was also examined. Cellular DNA fragmentation ELISA was performed to investigate the DNA fragmentation rates and an MTT assay was studied to evaluate the ID50. A TEM study revealed condensing and fragmentation of the chromatin. Laddering of the bands was observed in all EMP exposure groups in agarose gel electrophoresis. DNA fragmentation in all EMP groups began at 0.5 h following an exposure with EMP and increased in a dose- and time-dependent manner as revealed by DNA ELISA fragmentation. ID50 at 24 h was 5.0 microM according to the MTT assay, a value close to 4.8 microM of ID50 was revealed by the DNA fragmentation assay. None of the above mentioned changes was observed in the control group. These results indicated that EMP caused a drug-induced apoptosis in the human malignant glioma cell line, U87MG.

Antineoplastic Agents, Alkylating↗
PubMed2000

Suppression of cell invasion on human malignant glioma cell lines by a novel matrix-metalloproteinase inhibitor SI-27: in vitro study.

Matrix metalloproteinase (MMP) has come to be highlighted by its close relation to the cell invasion of gliomas. Suppression of MMP activity in malignant glioma cells would be meriting to local delivery of genes or chemotherapeutic agents. In this study, we employed a novel MMP inhibitor, SI-27 to investigate inhibition of cell invasiveness in human malignant glioma cell lines, U87MG, U251MG, and U373MG. We evaluated with zymogram, reverse zymogram, and cell invasion assay after exposure of SI-27 for 24 h followed by preliminary MTT assay to find non-cytotoxic dose range, 5, 10, 50, 100 microg/ml compared with non-treatment group as the control. Common to three glioma cell lines, zymogram disclosed that expressions of MMP-2 and -9 were suppressed in a dose-dependent fashion, meanwhile those of tissue inhibitor of MMP (TIMMP) in reverse zymogram were not. The numbers of invading cells through Boyden chamber were significantly reduced in a dose-dependent manner, while those with 5 microg/ml were not diminished common to those three lines. In conclusion, dose concentration ranging 10-100 microg/ml of SI-27 inhibited MMP-2 and -9 mediated cell invasiveness in malignant glioma cell lines. This is the first report for chemotherapeutic effect of SI-27 on glioma cells.

Brain Neoplasms↗
PubMed2000

Intracranial malignant meningioma with abdominal metastases associated with hypoglycemic shock: a case report.

A thirty-year-old male with an intracranial malignant meningioma, first diagnosed 9 years ago, with three recurrences was admitted with a hypoglycemic shock. The blood glucose level was 17 mg/dl, requiring treatment with high doses of intravenous and oral dextrose for improvement. A large metastatic tumor in the liver was noted. All hormones and peptides influencing blood glucose levels were in their normal levels. Chemo-embolization and injection of anti-cancer drugs was employed in the management of the metastatic tumor. Positron emission tomography was performed to measure the glucose metabolism of the abdominal tumor and it indicated that glucose consumption within the tumor was much elevated than the surrounding abdominal organs. Hypoglycemia secondary to primary hepatoma or islet-cell cancer has been frequently described, but a complication of metastatic meningioma is an exceedingly rare event. Elevated glucose consumption within the tumor might be addressed as one of the reasons for hypoglycemia, not due to the elevated serum levels of insulin or IGF, but due to the closely related blood glucose level.

Abdominal Neoplasms↗
PubMed2000

Expression of pituitary homeo box 1 (Ptx1) in human non-neoplastic pituitaries and pituitary adenomas.

We investigated the localization of pituitary homeo box 1 (Ptx1) protein in five human non-neoplastic pituitaries and 73 of all types of pituitary adenomas using immunohistochemistry, and the expression of Ptx1 messenger RNA (mRNA) in 18 representative pituitary adenomas using the reverse transcriptase polymerase chain reaction (RT-PCR) technique. By immunohistochemical analysis, Ptx1 protein was extensively detected in the nuclei of normal human pituitary cells. Ptx1 was detected in 10/14 (71.4%) of growth hormone (GH)-secreting adenomas, 12/12 (100%) of prolactin (PRL)-secreting adenomas, 18/20 (90%) of adrenocorticotropic hormone (ACTH)-secreting adenomas, 6/7 (85.7%) of thyroid-stimulating hormone (TSH)-secreting adenomas, and 17/20 (85%) of clinically non-functioning adenomas, including 9/10 (90%) of gonadotropin-subunit-positive adenomas. Thus, there was no relationship between Ptx1 expression and a particular type of pituitary adenomas. By RT-PCR analysis, Ptx1 mRNA was expressed in all 18 cases of pituitary adenomas, including two cases negative for Ptx1 protein by immunohistochemistry. These results suggested that Ptx1 may be an universal transcription factor in both neoplastic and non-neoplastic conditions in human pituitaries. The synergistic action with other transcription factors may be speculated to determine the specific production of the anterior pituitary hormones.

Adenoma↗
PubMed2000

Growth hormone-releasing hormone expression in pituitary somatotroph adenomas, studied by immunohistochemistry and in situ hybridization using catalyzed signal amplification system.

Growth hormone-releasing hormone (GHRH) is a well-known hypothalamic hormone that stimulates the synthesis and release of growth hormone (GH) as well as the proliferation of GH-producing cells in the anterior pituitary gland. Recent reports have shown GHRH synthesis in pituitary somatotroph adenomas, but GHRH immunoreactivity has not been shown in previous studies. To confirm the role of locally generated GHRH for the progression of somatotroph adenomas, we investigated the expression of GHRH in 25 pituitary somatotroph adenomas immunohistochemically, through the use of both conventional avidin-biotin-complex (ABC) method and novel catalyzed signal amplified (CSA) system. In addition, we investigated the expression of GHRH mRNA and GHRH receptor mRNA with in situ hybridization (ISH) using the CSA system. The weak immunopositivity of GHRH was observed in only 2 adenomas (8.0%) of 25 somatotroph adenomas using the ABC method. In contrast, 15 adenomas (60.0%) of 25 somatotroph adenomas were immunopositive for GHRH, as shown by CSA system. Very few of nonsomatotroph adenomas were immunopositive for GHRH using the CSA system. The expression of GHRH mRNA was confirmed, using the CSA-ISH system in 13 adenomas (72.2%) of 18 somatotroph adenomas. In 11 adenomas (61.1%) of 18 somatotrophic adenomas, the expression of GHRH receptor mRNA was demonstrated using the CSA-ISH system. This is a first report that clarified histopathologically GHRH production in pituitary somatotrophic adenomas. The demonstration of GHRH and its receptor expression is meaningful in clarifying the autocrine or paracrine regulation of GHRH in GH production and progression of pituitary somatotroph adenomas.

Adenoma↗
PubMed2000

Contributions of immunohistochemistry and in situ hybridization to the functional analysis of pituitary adenomas.

Immunohistochemistry (IHC) and recently in situ hybridization (ISH) have elucidated various aspects of human pituitary adenomas, i.e., functional differentiation and classification, transcription factors and mechanism of hormone production, regulation of hormone secretion, and processing of prohormones. Recently, the use of tyramide (catalyzed signal amplification; TSA or CSA) and RT-PCR has been effective for detection of trivial amount of proteins (peptides) and mRNA, respectively. Immunomolecular histochemistry is expected to further clarify the function and biology of human pituitary adenomas.

Adenoma↗
PubMed2000

Pituitary insufficiency after penetrating injury to the sella turcica.

We report a 28-year-old male patient with a pituitary insufficiency after a simple fracture of the sella turcica. He was injured by a long nail that punctured the lower jaw. No fracture other than that of the sella turcica was detected. An endocrinological examination revealed both anterior and pituitary dysfunction and diabetes insipidus that continued for about two months.

Adult↗
PubMed2000

Serum concentrations of 20K human growth hormone in normal adults and patients with various endocrine disorders. Study Group of 20K hGH.

The 20K hGH isoform is produced by alternative splicing of GH mRNA, and comprises approximately 10% of all GH in the pituitary. The physiological role of 20K hGH remains to be determined partly because of the lack of a simple and specific assay. We have established sensitive enzyme-linked immunoadsorbent assays (ELISAs) specific to 20K and 22K hGH. The serum levels of 20K hGH after overnight fasting was 118 +/- 178 pg/mL (N=282) in normal women, significantly higher than in normal men (64 +/- 170 pg/mL, N=226). However, there was no difference in the proportion of 20K hGH to 20K plus 22K hGH between men (6.3 +/- 2.6%, N=176) and women (6.3 +/- 2.1%, N = 263). No correlation was detected between the ratio of 20K hGH and age, body height, body weight or body fat mass in normal subjects. The proportion of 20K hGH was significantly (P < 0.001) higher in patients with active acromegaly (9.2 +/- 2.2%, N=33) and in patients with anorexia nervosa (9.0 +/- 1.9, N=8), both of which are characterized by chronic elevation of circulating GH levels. The proportion of the 20K hGH in successfully treated acromegalic patients did not differ from that in normal subjects, suggesting that GH-producing pituitary tumors secrete a higher proportion of 20K hGH, or chronic excess of 22K hGH altering the metabolic clearance rate of 20K hGH. The values in patients with adult growth hormone deficiency (GHD), hyperthyroidism, primary hypothyroidism, or GH-independent short stature did not differ from those in normal subjects. The 20K ratio did not change after acute GH provocative tests such as insulin tolerance test and GRH test. These results suggest that secretion of 20K hGH from the pituitary is under the same control as that of 22K hGH.

Acromegaly↗