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Biomedical subjects

A Teramoto

Publications and source records attributed to A Teramoto.

At least 109 records · Page 6Linked to original sources
PubMed1998

Emergence of immunoreactivities for phosphorylated tau and amyloid-beta protein in chronic stage of fluid percussion injury in rat brain.

Head injury is one of the potential environmental factors in Alzheimer's disease (AD). To study the chronic stage of concussive brain injury, histological analyses were performed 2-6 months after right lateral fluid percussion (FP) brain injury (3.6-4.8 atm) in rats. Six months after injury, numerous normal-looking neurons in the telencephalon and brain stem were immunoreactive with either antibody to phosphorylated tau or with four antibodies to beta-amyloid protein. Neuronal counts in the cortices were gradually decreased after injury, up to 42% loss at 6 months after injury. These neuropathological changes suggest that this animal model could serve as a good animal model of neurodegenerative diseases such as AD.

Amyloid beta-Peptides↗
PubMed1998

Effects of polyelectrolyte complex (PEC) on human periodontal ligament fibroblast (HPLF) function. I. Three-dimensional structure of HPLF cultured on PEC.

Human periodontal ligament fibroblast (HPLF) cultured on tissue culture dishes (TCD), irrespective of the presence of serum, showed only a spreading form. In contrast, using polyelectrolyte complex (PEC) as a matrix, HPLF showed spreading, round, and aggregate forms. Cells of the inner part of the aggregate contacted with each other to form a three-dimensional structure, and this condition corresponded to typical tissues in vivo. These seemed to be related to the interrelation between growth and morphology; that is, the HPLF of the spreading form was considered to belong to a proliferation phase, and the HPLF of the round and aggregate forms, with a little growth, seemed to belong to a functional phase of the cell cycle, indicating that PEC is able to control such cell functions as proliferation, morphology, and differentiation. The cell aggregate was observed only on PEC with carboxymethyl residues and was stained by alizarin red (AR), which suggested mineralization. The spreading cells on PEC containing sulfate residues were not stained by AR. Therefore, it was found that there was a certain relationship between cell growth and morphology, and that PEC affected the cell cycle and promoted proliferation and differentiation of HPLF.

Biocompatible Materials↗
PubMed1998

Effects of polyelectrolyte complex (PEC) on human periodontal ligament fibroblast (HPLF) function. II. Enhancement of HPLF differentiation and aggregation on PEC by L-ascorbic acid and dexamethasone.

In addition to many types of extra cellular matrix (ECM) in vivo, cells are stimulated by many types of vitamins, hormones, growth factors, etc. In this paper the effects of L-ascorbic acid 2-phosphate (Asc-2P) and dexamethasone (Dex) on proliferation and differentiation of human periodontal ligament fibroblast (HPLF) using polyelectrolyte complex (PEC) as a matrix in vitro will be discussed. The PEC was composed of chitosan as a polycation, with carboxymethyl (CPEC) or sulfated chitin (SPEC). Asc-2P (0.2 mM) inhibited the growth of HPLF on CPEC, but promoted the growth on SPEC. Moreover, the aggregation of HPLF on CPEC was inhibited by Asc-2P, but that on SPEC was induced in the presence of Asc-2P and Dex. Although Asc-2P reduced an increase in alkaline phosphatase (ALPase) activity of HPLF on CPEC as well, it induced a twofold increase in ALPase activities on SPEC and TCD. Furthermore, in the medium containing Asc-2P and 100 mM of Dex, cell growth was inhibited, but ALPase activity was promoted on both SPEC and TCD to form many aggregates on SPEC. ALPase activity increased by twofold over that of HPLF cultured in the medium containing only Asc-2P. Therefore, it is suggested that the cell functions of HPLF are controlled by the combination of PEC and additives.

Alkaline Phosphatase↗
PubMed1998

Three-dimensional CT angiography of intracranial vasospasm following subarachnoid haemorrhage.

We evaluated the usefulness of three-dimensional CT angiography (3D-CTA) in the diagnosis of intracranial vasospasm following subarachnoid haemorrhage (SAH) in 13 patients suspected of having vasospasm on clinical grounds. The intracranial vessels were clearly shown by 3D-CTA in 12 patients. 3D-CTA revealed spasm in the vessels of nine patients. Catheter angiography performed in seven of these patients immediately after 3D-CTA confirmed vasospasm. A low-attenuation area was seen on CT in the other two patients, representing an ischaemic lesion due to the spasm. In nine patients, a second 3D-CTA was performed using the same technique 1 week after the first, showing no vasospasm. Initial 3D-CTA revealed no vasospasm change in three patients. Following 3D-CTA, one of these had conventional angiography, which also demonstrated no spasm.

Adult↗
PubMed1998

Hypertrophic cranial pachymeningitis in a patient with aplastic anemia.

We report on a 13-year old girl with severe aplastic anemia and hypertrophic cranial pachymeningitis. She was admitted to our hospital with severe headache and vomiting. A computerized tomographic (CT) scan of the brain on the third day of symptoms showed a hyperdense area in the tentorial region. Magnetic resonance imaging (MRI) showed iso-intensity in the same tentorial region in T1- and T2-weighted images, and gadolinium enhancement of this region suggested a thickened dura mater. Initially, a diagnosis of subdural or subarachnoid hemorrhage was made. Since her platelet count was low (3000/microl) making the patient a poor-risk candidate for surgery, and the area was limited to the dura mater, conservative therapy, including glycerol administration and platelet transfusion, was carried out. Despite clinical improvement 10 days after admission without specific therapy, the iso-intense region on the left side of the tentorial region remained unchanged on MRI. On the other hand, the iso-intense area on the right side of the tentorial region became hyperdense on T1-weighted MRI images and was also enhanced by gadolinium. Cerebrospinal fluid findings were normal except for slightly elevated protein at 62 mg/dl. A diagnosis of hypertrophic cranial pachymeningitis of the tentorial dura mater with hemorrhage on the right side was made. Although hypertrophic cranial pachymeningitis is a rare disease, it must be considered in the differential diagnosis of severe headache in a case of aplastic anemia.

Anemia, Aplastic↗
PubMed1998

Suppression of matrix metalloproteinase-2-mediated cell invasion in U87MG, human glioma cells by anti-microtubule agent: in vitro study.

Because microtubules are important components of cell motility and intracellular transport, it is reasonable to propose that the depolymerizing effect of an antimicrotubule agent, estramustine, on glioma microtubules would modulate cell invasiveness. To determine whether matrix metalloproteinases, key factors in cell invasion, are affected by exposure to estramustine, a cell proliferation assay, a zymogram, a collagenolysis assay and a haptoinvasion assay were used in this study. The zymogram revealed that an activated (62 kDa) form of matrix metalloproteinase-2 diminished with increasing estramustine concentrations. The collagenolysis assay demonstrated approximately 2.5- to 21-fold lower rates of enzymatic activity suppressed by estramustine in a dose-dependent manner at estramustine concentrations of 1, 5, and 10 microM, compared with the control group. On the haptoinvasion assay, no statistically significant difference was seen in the 0.5 microM estramustine group, whereas 1-10 microM estramustine groups revealed significant suppression of invasion from 6 to 24 h in a dose-dependent manner. The results suggest that estramustine suppresses the invasion of U87MG cells in vitro using the decreasing available matrix metalloproteinase-2, an effect caused by the disassembly of microtubules. Suppression of the infiltrative capacity of malignant glioma cells could be of significant value in the treatment of this disease.

Antineoplastic Agents, Alkylating↗
PubMed1998

Expression of Pit-1 mRNA and activin/inhibin subunits in clinically nonfunctioning pituitary adenomas. In situ hybridization and immunohistochemical analysis.

The pituitary-specific transcriptional factor Pit-1 is known to play a role in the development and differentiation of pituitary cells. Recent investigations have suggested a role for this transcriptional factor in pituitary adenomas, especially growth hormone (GH)- and prolactin (PRL)-secreting pituitary adenomas. In this study we analyzed the expression of Pit-1 mRNA and its protein in 24 clinically nonfunctioning pituitary adenomas in comparison with normal pituitary glands using in situ hybridization (ISH) and immunohistochemistry (IHC). The interaction between inhibin/activin, a member of the transforming growth factor-beta family, and Pit-1 was also studied. Immunohistochemically, Pit-1 protein was detected in 9 of 24 adenomas (37.5 %), and 8 of these 9 were also positive for the alpha subunit of glycoprotein (alphaSU). The expression of Pit-1 mRNA was detected in 14 of 24 (58.3%) clinically nonfunctioning adenomas, and it was found in all cases which expressed the Pit-1 protein. By the combined ISH and IHC method, Pit-1 mRNA was frequently observed in alphaSU-immunopositive cells in adenomas. The inhibin/activin alpha subunit was detected in all 24 adenomas and the betaA subunit was detected in 13 of 24 adenomas. The inhibin/activin betaA subunit was detected frequently with Pit-1 mRNA. From our observations, the inhibin/activin betaA subunit in nonfunctioning adenomas may have related the expression of Pit- mRNA in these adenomas.

Activins↗
PubMed1998

Effect of polyelectrolyte complex (PEC) on human periodontal ligament fibroblast (HPLF) functions in the presence of glucocorticoids.

Cell functions in vivo are stimulated by extracellular matrices, vitamins, growth factors, and hormones. In this paper, the effects of glucocorticoids, dexamethasone (Dex), and Cortexrone (Cor) on the growth and differentiation of human periodontal ligament fibroblast (HPLF) were discussed in relation to a polyelectrolyte complex (PEC) consisting of polysaccharides (chitin, cellulose derivatives, and chitosan) as a tissue-culture material. A Dex-treatment at a concentration of 10(-)-10(-7) M inhibited one-half of HPLF growth in comparison with 10(-9) M Dex-treatment and no additive medium and produced aggregates on the chitosan-sulfated chitin PEC (SPECs) with regard to the degree of sulfate substitution. On the chitosan-sulfated cellulose PEC, 10(-7)-10(-9) M Dex-treatment promoted HPLF growth and inhibited the production of aggregates. On the other hand, a Cor-treatment, a mineral corticoid, which inhibits the interaction between Dex and its receptor, increased HPLF growth on SPEC141, but the HPLF did not construct aggregates. A Dex and Cor mixture-treatment inhibited one-third HPLF growth in comparison with 10(-5) M Dex-treatment and produced aggregates on PEC. The cooperative effect of both the culture material and hormones was found to control HPLF growth and morphology. The alkaline phosphatase (ALPase) activities of HPLF increased with an increase in the Dex and Cor concentration. The value of Dex-treated HPLF ALPase activity demonstrated a two-fold increase from that with Cor-treatment. The ALPase activity of Dex and Cor mixture-treated HPLF on PEC decreased with an increase in the Cor concentration, because Cor increased HPLF growth on PEC. In using carboxymethylated chitin derivatives as the polyanion, HPLF decreased in cell growth and produced aggregates in the absence of the additives, suggesting that PEC induces HPLF differentiation using only the stimulation of the material surface.

Alkaline Phosphatase↗
PubMed1998

Treatment of posterior skull base tumors.

Surgery for posterior skull base tumors may be associated with high morbidity and mortality because of the complex anatomy, irregular bony topography, and vital neurovascular structures in this region. We experienced three benign posterior skull base tumors. These were petroclival and foramen magnum meningiomas and a jugular formen neurinoma. Three dimensional computed tomography (3 D-CT) in addition to the conventional CT, magnetic resonance imaging (MRI), and cerebral angiography were performed preoperatively. Preoperative embolizations for the tumors were also done, and intraoperative neurophysiological monitorings were performed. The tumors could be subtotally removed with no damage to the brainstem, cranial nerves, and vessels. No newly developed postoperative neurological symptoms were observed. As to the remaining tumors, gamma knife (gamma-knife) therapy was planned. 3 D-CT was very useful in the preoperative evaluation of the surgical approach, and the intraoperative neurophysiological monitoring was considered to be necessary to prevent permanent damage. gamma-knife after direct approach was recommended for the benign posterior skull base tumors.

Adult↗
PubMed1998

Malignant fibrous histiocytoma in the parietal bone.

Malignant fibrous histiocytomas (MFHs) are mesenchymal tumors, usually arising in soft tissue of the extremities and are remarkably resistant to radiation and chemotherapy. A 45-year-old female presented with a rare case of MFH originating in the cranial bone manifesting as a lump in the left parietal region with no neurological abnormality. Neuroimaging revealed the presence of an osteolytic tumor in the left parietal bone invading into muscle and subdural region, penetrating through the dura. Selective external carotid angiography disclosed a marked tumor stain. Examination of the whole body excluded neoplastic disease elsewhere. The patient was treated by surgical excision, radiation, and two courses of multi-drug chemotherapy using cyclophosphamide, doxorubicin, vincristine, and prednisolone. Since there is no established treatment against this malignancy, a longer follow-up is necessary to determine whether cure has been achieved.

Combined Modality Therapy↗
PubMed1998

Magnetic resonance imaging-documented extravasation as an indicator of acute hypertensive intracerebral hemorrhage.

OBJECT: The aim of this study was to determine the usefulness of magnetic resonance (MR) imaging-documented extravasation as an indicator of continued hemorrhage in patients with acute hypertensive intracerebral hemorrhage (ICH). METHODS: The authors studied 108 patients with acute hyperintensive ICH. Imaging modalities included noncontrast-enhanced computerized tomography (CT) scanning, gadolinium-enhanced MR imaging, and conventional cerebral angiography obtained within 6 hours after the onset of hemorrhage. A repeated CT scan was obtained within 48 hours to evaluate enlargement of the hematoma. Findings on MR imaging indicating extravasation, including any high-intensity signals on T1-weighted postcontrast images, were observed in 39 patients, and 17 of these also showed evidence of extravasation on cerebral angiography. The presence of extravasation on MR imaging was closely correlated with evidence of hematoma enlargement on follow-up CT scans (p < 0.001). CONCLUSIONS: Evidence of extravasation documented on MR imaging indicates persistent hemorrhage and correlates with enlargement of the hematoma.

Acute Disease↗
PubMed1998

Cavernous sinus sampling in patients with adrenocorticotrophic hormone-dependent Cushing's syndrome with emphasis on inter- and intracavernous adrenocorticotrophic hormone gradients.

OBJECT: As an alternative method to inferior petrosal sinus sampling with administration of corticotropin-releasing hormone (CRH), the authors have developed a method of selective venous sampling directly from the cavernous sinus, which is performed using a superselective catheterization technique. The goal of this study is to assess this method. METHODS: Catheterization to the cavernous sinus was performed in 44 patients with clinical and biochemical features of Cushing's syndrome. Forty of these patients in whom there was a definite clinical and/or histological diagnosis were evaluated. In 35 patients, a pituitary microadenoma was detected on magnetic resonance imaging and/or during surgery. Ectopic lesions were suspected in five patients, who later developed nonpituitary tumors. The central/peripheral (C/P) ratios of adrenocorticotrophic hormone (ACTH) without CRH administration ranged from 5.2 to 448.1 (mean+/-standard deviation, 66.7+/-91.2) in cavernous sinuses and from 1.1 to 52 (mean+/-standard deviation, 8.5+/-9.9) in the inferior petrosal sinuses. The petrosal sinus sampling contained false negative results in eight patients (23%) based on a cutoff point of 2. On the contrary, patients with ectopic lesions did not show any increase in ACTH levels in either sampling portion. The intercavernous gradients of ACTH, ranging from 1.2 to 506.4, indicated the correct lateralization of microadenoma in the lateral wing in all 30 patients. The interpetrosal gradients, ranging from 1 to 31.4, did not give a sufficient value (> or = 1.4) in four patients (13%) with a lateral lesion. In five cases of midline tumors, the intercavernous and interpetrosal gradients indicated false laterality in three and four cases, respectively. The intracavernous (posterior-anterior) gradients, ranging from 1.04 to 60.7 (mean 14.9), showed a higher concentration of ACTH in the posterior portion of the sinus in all patients. CONCLUSIONS: These results suggest that 1) cavernous sinus sampling without CRH administration can demonstrate hypersecretion of ACTH from the pituitary gland with a high diagnostic accuracy; 2) intercavernous gradients will indicate the correct lateralization in laterally localized microadenomas; and 3) sampling should be performed from the posterior portion of the cavernous sinus.

Adolescent↗
PubMed1998

Localization of prohormone convertases 1/3 and 2 in the human pituitary gland and pituitary adenomas: analysis by immunohistochemistry, immunoelectron microscopy, and laser scanning microscopy.

Prohormone convertase (PC) 1/3 and PC2 are involved in post-translational processing of endocrine tissues, including the pancreatic islets and pituitary glands. Our immunohistochemical studies disclosed the presence of PC1/3 and PC2 in non-neoplastic pituitary glands, especially in corticotrophs, gonadotrophs, and thyrotrophs. Among 58 pituitary adenomas obtained by trans-sphenoidal surgery, adrenocorticotropin (ACTH)-secreting adenomas showed a high incidence of the presence of PC1/3 and PC2, i.e., nine of nine cases were positive for ACTH. Five of nine cases showed consistency between PC2 localization and alpha-melanocyte stimulating hormone immunoreactivity, which suggests the functional correlation between PC2 and the processing of ACTH. In four cases, we observed inconsistency in immunolocalization, which suggested the possibility of inactive PC2 and abnormal processing of alpha-melanocyte stimulating hormone. The high incidence of PC1/3 and PC2 in nonfunctioning adenomas might be related to the processing of chromogranin A.

Adenoma↗
PubMed1998

[Changes of arterial ketone body ratio (AKBR) in patients with intracerebral hemorrhage].

The arterial ketone body ratio (AKBR) is considered to be an accurate index of the functional reserve of the liver, and the validity of this idea has been confirmed in the field of abdominal surgery. We found low AKBR value intracerebral hemorrhage patients and discussed the clinical significance of this finding in this paper. Twenty-five patients with intracerebral hemorrhage treated at our institution were included in this study. Their ages ranged from 42 to 86 years old (average 68.5 years). There were 13 cases of putaminal hemorrhage and 12 cases of thalamic hemorrhage. Evacuation of the hematoma or ventricle drainage was performed in 20 of these cases within 3 days after symptoms of intracerebral hemorrhage appeared. There were 12 cases with intraventricular hemorrhage. The outcome of these patients was as follows; 17 cases survived, eight cases died. We collected blood samples on days 1, 2, 3, 7 and 10 after the onset of symptoms (day 0) and measured the following: 1, beta-hydroxybutyrate; 2, acetoacetate; 3, epinephrine; 4, norepinephrine. On day 0 total ketone body levels were higher (246.3 +/- 231.7 mumol/l), AKBR values (0.60 +/- 0.18) were significantly lower than in the control group (2.05 +/- 1.35) (p < 0.001). However, both epinephrine and norepinephrine levels were significantly higher, 638.4 +/- 229.0 pg/ml and 1036.5 +/- 288.2 pg/ml, respectively. The AKBR value was 0.76 +/- 0.19 on day 1, 1.04 +/- 0.30 on day 2, and increased thereafter. In addition, the relation between sequential changes of AKBR in patients with intraventricular hemorrhage and outcome were also discussed. AKBR values are known to decrease not only in cases of hepatic failure, but in cases in which the liver energy charge is reduced, such as shock and hypoxemia, but no investigations have ever been performed to determine whether AKBR is altered in cerebrovascular disease. In this study, we found that AKBR values were lower in intracerebral hemorrhage, presumably due to reduced hepatic blood flow causes by increased levels of epinephrine and norepinephrine. In addition, our findings suggest that the fluctuations in AKBR values correlated with the outcome of intracerebral hemorrhage patients.

Adult↗
PubMed1998

[Inhibition of fibroblast growth factor receptor 1 expression in human glioblastoma cell contributes to the cell growth suppression].

Although normal human astrocytes rarely express fibroblast growth factor receptor 1 (FGFR 1) mRNA, expression of FGFR 1 mRNA in astrocytomas increases as malignancy progresses. This result suggests that FGFR 1 can be one of important factors for glioblastoma cell growth. In our study, specific antisense oligonucleotides for FGFR 1 mRNA inhibited cell growth of SNB 19, human glioblastoma cell line, while sense oligonucleotides showed no cell reduction. And Southern blot analysis demonstrated decreased expression of FGFR 1 mRNA in only antisense group. Furthermore, cross-linking analysis revealed decreased number of FGFR 1 in antisense-treated SNB 19 in protein level. These results conclude that cell growth inhibition was caused by suppression of both transcription and translation of FGFR 1 mRNA. Interestingly, alpha-specific antisense also inhibited expression of beta-, and gamma-type of FGFR 1 mRNA which had no binding sites for the oligonucleotides. This fact indicates that antisense oligonucleotides binds to premature mRNA, which is previous form of mature mRNA before splicing, in nucleus. It is previously reported that basic fibroblast growth factor (bFGF), major ligand to FGFR 1, was overly expressed in human malignant astrocytomas. Thus, increased number of FGFR 1 may contribute to the acceleration of bFGF autocrine or paracrine mechanism in glioblastoma.

Brain Neoplasms↗