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Y Ida

Publications and source records attributed to Y Ida.

At least 19 recordsLinked to original sources
PubMed2001

Human cystine/glutamate transporter: cDNA cloning and upregulation by oxidative stress in glioma cells.

A human cDNA for amino acid transport system x(C)(-) was isolated from diethyl maleate-treated human glioma U87 cells. U87 cells expressed two variants of system x(C)(-) transporters hxCTa and hxCTb with altered C-terminus regions probably generated by the alternative splicing at 3'-ends. Both hxCTa and hxCTb messages were also detected in spinal cord, brain and pancreas, although the level of hxCTb expression appears to be lower than that of hxCTa in these tissues. When expressed in Xenopus oocytes, hxCTb required the heavy chain of 4F2 cell surface antigen (4F2hc) and exhibited the Na(+)-independent transport of L-cystine and L-glutamate, consistent with the properties of system x(C)(-). In agreement with this, 137 kDa band was detected by either anti-xCT or anti-4F2hc antibodies in the non-reducing condition in western blots, whereas it shifted to 50 kDa or 90 kDa bands in the reducing condition, indicating the association of two proteins via disulfide bands. We found that the expression of xCT was rapidly induced in U87 cells upon oxidative stress by diethyl maleate treatment, which was accompanied by the increase in the L-cystine uptake by U87 cells. Because of this highly regulated nature, xCT in glial cells would fulfill the task to protect neurons against oxidative stress by providing suitable amount of cystine to produce glutathione.

Alternative Splicing↗
PubMed2001

Construction of a computed tomographic phantom for a Japanese male adult and dose calculation system.

Computational human phantoms have been widely used to estimate organ doses and other dosimetric quantities related to the human body where direct measurements are difficult to perform. In recent years, voxel phantoms (voxel = volume element) based on computed tomographic (CT) data of real persons have been constructed which provide a realistic description of the human anatomy. A CT phantom of a Japanese male adult with an average body size was developed as the first Asian voxel phantom. The segmented phantom consists of more than 100 regions enabling the calculation of doses for various parts of the body. The bone marrow distribution was precisely modelled according to the CT values. The EGS4 Monte Carlo transport code was combined with the phantom to calculate organ doses for external exposure due to photons and electrons up to 1 TeV. The calculated organ doses were compared with respective data using MIRD-type mathematical phantoms. In some cases, significant discrepancies in doses were observed, demonstrating the necessity of sophisticated models for accurate dose calculations.

Adult↗
PubMed2000

[A case of high flow CCF with congestive hemorrhage].

The authors report a case of high flow CCF with intracerebral hemorrhage during treatment with endovascular coil embolization. A 52-year-old woman had been in good health until a sudden onset of orbital bruit and left orbital tinnitus occurred. Conjunctival chemosis and diplopia caused by left abducens palsy gradually progressed. Left internal carotid arteriography revealed a carotid-cavernous sinus fistula with direct high-flow shunt. The fistula drained into the superior orbital vein, inferior petrosal sinus, intercavernous sinus and sphenoparietal sinus with significant cortical reflux. The attempt at transarterial balloon occlusion failed. Then transvenous coil embolization was performed. During the course of endovascular treatment, follow up CT depicted intracerebral hemorrhage. Intracerebral hemorrhage was asymptomatic and thought to be caused by venous hypertension from cortical reflux. The patient underwent direct occlusion of the left sphenoparietal sinus for prevention of further hemorrhage via craniotomy. Lastly, the cavernous sinus was completely occluded by transvenous coil embolization. The signs and symptoms resolved 3 months after the procedures.

Carotid-Cavernous Sinus Fistula↗
PubMed1999

Triterpenoid saponins of Acanthopanax nipponicus leaves.

Five new triterpenoid saponins, nipponosides A-E (1, 3-6), were isolated from Acanthopanax nipponicus leaves, along with a known saponin, kalopanaxsaponin G (2). Nipponosides A-E were characterized as the 28-O-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)-beta -D-glucopyranosyl ester of 3-oxohederagenin, oleanolic acid 3-O-beta-D-glucopyranoside, gypsogenin 3-O-beta-D-glucopyranoside, 3beta,23,29-trihydroxyolean-12-en-28-oic acid, and 3beta,20alpha, 23-trihydroxy-30-nor-olean-12-en-28-oic acid, respectively. The structures of these new compounds were based on chemical and spectral methods.

Carbohydrate Sequence↗
PubMed1999

beta-hydroxyisovalerylshikonin inhibits the cell growth of various cancer cell lines and induces apoptosis in leukemia HL-60 cells through a mechanism different from those of Fas and etoposide.

beta-Hydroxyisovalerylshikonin (beta-HIVS), which was isolated from the plant, Lithospermium radix, inhibited the growth of various lines of cancer cells derived from human solid tumors at low concentrations between 10(-8) and 10(-6) M. When HL-60 cells were treated with 10(-6) M beta-HIVS for 3 h, characteristic features of apoptosis, such as DNA fragmentation, nuclear fragmentation, and activation of caspase-3-like activity, were observed. The most characteristic features of the effect of beta-HIVS were the remarkable morphological changes induced upon treatment of HL-60 cells with beta-HIVS, as visualized on the staining of actin filaments with phalloidin labeled with tetramethylrhodamine B isothiocyanate. Moreover, activation of MAP kinases, such as ERK2, JNK and p38, was detected after treatment with 10(-6) M beta-HIVS preceding the appearance of the characteristics of apoptosis, and the features of the activation of these MAP kinases were quite different from those of Fas and anticancer drug-induced apoptosis. The activation of JNK by beta-HIVS was not inhibited by inhibitors of caspases, suggesting that JNK is located either upstream or independent of the caspase signaling pathway. beta-HIVS did not inhibit the activity of topoisomerase II. These results indicate that beta-HIVS induces apoptosis in HL-60 cells through a mechanism unlike those reported for anti-Fas antibodies and etoposide.

Antineoplastic Agents↗
PubMed1999

[Brain surface clear cell ependymoma: case report].

We report a case of brain surface clear cell ependymoma. A 13-year-old boy presented with complaints of right hypesthesia. Computed tomography and magnetic resonance image showed a left fronto-parietal cystic, calcified mass lesion. He underwent total resection of the tumor including cyst wall. The tumor located on the surface of the parietal lobe was sharply demarcated from the surrounding brain tissue and there was no continuity with the ventricular wall. Histological examination of the surgical specimens showed oligodendroglioma-like cells that had round unclei, clear cytoplasm which formed perivascular pseudorosettes, and immunoreactivity for glial fibrillary acidic protein (GFAP). Electromicroscopically, microvilli were seen. The findings were compatible with clear cell ependymoma. The cyst wall was lined with a layer of single cuboidal cells and, immunohistochemically, had no basal membrane. The inner surface of the cyst was positive for EMA, and the cuboidal cells were positive for GFAP. We discuss possible mechanisms for tumor growth in our case and the histogenesis of its cyst.

Adolescent↗
PubMed1998

Two novel oleanolic acid saponins having a sialyl Lewis X mimetic structure from Achyranthes fauriei root.

Two novel triterpene glycosides, achyranthosides E and F, were isolated as methyl esters from the root of Achyranthes fauriei, an antiinflammatory medicinal plant. Their structures were characterized as oleanolic acid glucuronides having unique substituents composed of C6H9O5 and C9H15O7, respectively, at the C-3 position of glucuronic acid. These compounds are active components which can inhibit the excess recruiting of neutrophiles to injured tissues 1,000 times more potently than sialyl Lewis X.

Magnetic Resonance Spectroscopy↗
PubMed1998

Interaction between sodium ascorbate and dopamine.

The interaction between sodium ascorbate and dopamine was investigated by three different parameters: radical intensity, prooxidant action, and cytotoxicity induction. Sodium ascorbate and dopamine produced the doublet and quartet ESR signals under alkaline conditions (pH 8.0-9.5), respectively. Addition of increasing concentrations of sodium ascorbate completely scavenged the dopamine radical and replaced the latter with its own radical. Similarly, dopamine slightly, but significantly reduced the radical intensity of sodium ascorbate. These two compounds stimulated the methionine oxidation and hydrogen peroxide generation in culture medium, but in combination, their stimulation activities were weakened. Both of these two compounds dose-dependently reduced the viable cell number of human oral squamous carcinoma HSC-4 cells, and their cytotoxic activity was significantly reduced by catalase. When these two compounds were mixed together before adding to HSC-4 cells, both of their cytotoxic activities were diminished. The present study demonstrates the interaction between sodium ascorbate and dopamine, which might modify their biological activities and generation of nerve disorders such as Parkinson's disease.

Amino Acids↗
PubMed1998

Synthetic sialylphosphatidylethanolamine derivatives bind to human influenza A viruses and inhibit viral infection.

We synthesized the sialylphosphatidylethanolamine (sialyl PE) derivatives Neu5Ac-PE, (Neu5Ac)2-PE, Neu5Ac-PE (amide) and Neu5Ac-PE (methyl). We examined the anti-viral effects of the derivatives on human influenza A virus infection by ELISA/virus-binding, hemagglutination inhibition, hemolysis inhibition and neutralization assays. The sialyl PE derivatives that we examined bound to A/Aichi/2/68, A/Singapore/1/57 and A/Memphis/1/71 strains of H3N2 subtype, but not to A/PR/8/34 strain of H1N1 subtype. The derivatives inhibited viral hemagglutination and hemolysis of human erythrocytes with A/Aichi/2/68 and A/Singapore/1/57 (H3N2), but not with A/PR/8/34 (H1N1). The inhibitory activity of the (Neu5Ac)2-PE derivative was the strongest of all sialyl PE derivatives (IC50, 35 microM to 40 microM). Sialyl PE derivatives also inhibited the infection of A/Aichi/2/68 in MDCK cells. Complete inhibition was observed at a concentration between 0.3 to 1.3 mM. IC50 of (Neu5Ac)2-PE was 15 microM in A/Aichi/2/68 strain. Taken together, the synthetic sialyl PE derivatives may be effective reagents against infection of some types of influenza A viruses.

Antibodies, Viral↗
PubMed1998

Dual associations between hand preference and visual asymmetry in perception of faces.

A hand preference questionnaire and a face-matching task were administered to 83 female college students. Although the first and the second factor scores of hand preference correlated with a leftward perceptual bias on the face-matching task, the first factor correlated positively and the second negatively. Consistently, all of hand-preference items loading on the first factor correlated positively, and most items loading on the second factor negatively. Further, the bias for right-hand use of each hand-preference item correlated with the leftward perceptual bias. Hand preference may have independent dual associations with perceptual asymmetries, and factors of hand preference and bias for the right hand use may distinguish between the associations.

Adolescent↗
PubMed1998

[Bilateral aplasia of the internal carotid artery: a case report].

We report a case of bilateral aplasia of the internal carotid arteries. A 59-year-old man was admitted with generalized convulsions. Computed tomography and magnetic resonance imaging of the head showed normal findings. Three-dimensional computed tomography, angiography, and intra-arterial digital subtraction angiograms showed bilateral aplasia of the internal carotid arteries. The bilateral ophthalmic arteries were filled from the hypoplastic carotid arteries, and the anterior and middle cerebral arteries were filled from the basilar artery via the posterior communicating arteries. Associated with this bilateral aplasia of the internal carotid arteries, intracranial aneurysms and megadolicho-basilar anomaly were reported. Angiography is to be recommended if IC aplasia is suspected.

Carotid Artery, Internal↗
PubMed1997

Stimulative effects of saponin from kikyo-to, a Japanese herbal medicine, on pancreatic exocrine secretion of conscious rats.

Our previous report stated that kikyo-to, a Japanese herbal medicine, consisting of the roots of Platycodon grandiflorum and Glycyrrhiza sp., stimulates the pancreatic exocrine secretion of conscious rats. The present study focused on the effective components of kikyo-to and the mechanism of stimuli to pancreatic secretion of rats. When 10 to 100 mg of platycodin D, a saponin from the root of Platycodon grandiflorum, was intragastrically administered, the pancreatic secretion of rats was stimulated. At the same time, the plasma CCK concentration increased. On the other hand, the stimulative effects of glycyrrhizin, a saponin from the root of Glycyrrhiza sp. were weak compared to platycodin D. The effects of 10 mg/kg of platycodin D on pancreatic secretion were inhibited by loxiglumide (50 mg/kg, i.g.), a CCK receptor antagonist. In contrast, the suppressive effect of atropine (300 micrograms/kg/h, i.v.) on pancreatic secretion was reduced by administering 10 mg/kg of platycodin D. In addition, up to 1 mM of platycodin D did not inhibit the trypsin activities in vitro. In conclusion, kikyo-to serves to stimulate pancreatic exocrine secretion mainly because platycodin D causes gastrointestinal hormones, particularly, CCK to be released from the duodenum.

Animals↗
PubMed1996

Guidance with real-time CT fluoroscopy: early clinical experience.

A recently developed real-time computed tomography (CT) fluoroscopy system, which provides effective real-time reconstruction and display of CT images, was used to monitor nonvascular interventional procedures performed in 57 patients. Biopsy of thoracic lesions (n = 38), biopsy or drainage of pelvic lesions (n = 6), drainage or aspiration of intracranial hematomas (n = 9), and other procedures (n = 4) were performed. CT fluoroscopy successfully depicted the entire procedure in all patients. In thoracic lesions, a mean 1.3 passes was necessary to gain access to the lesion. Sufficient cytologic samples were obtained in 32 of 33 pulmonary lesions with a mean diameter of 26 mm.

Adult↗
PubMed1996

Radiation dosimetry at CT fluoroscopy: physician's hand dose and development of needle holders.

The radiation dose to physicians' hands without and with use of needle holders was determined at 10 computed tomography (CT) fluoroscopy-guided transthoracic needle biopsies. As measured with ionization chambers (tube voltage, 80 kVp; tube current, 30 mA), the mean absorbed dose rate without and with holders was 1.14 mGy/sec +/- 0.02 (standard deviation) and 0.019 mGy/sec +/- 0.001, respectively. The mean duration of CT fluoroscopy was 59 seconds in 10 biopsies performed with a holder and 82 seconds in 10 biopsies performed without a holder (difference not statistically significant). The needle holders did not cause any artifacts that interfered with the biopsy procedure.

Biopsy, Needle↗
PubMed1995

Trigeminal neuralgia associated with venous angioma--case report.

A 35-year-old male presented with trigeminal neuralgia associated with venous angioma at the root entry zone. Magnetic resonance imaging and angiography demonstrated a venous angioma with a dilated petrosal draining vein, and displacement of the anterior inferior cerebellar artery (AICA). The AICA and dilated petrosal vein were both decompressed, resulting in complete relief from symptoms of trigeminal neuralgia for 30 months. Microvascular decompression rather than resection of venous angioma is recommended for treatment of such cases. The possibility of a venous anomaly should be considered in younger patients with trigeminal neuralgia.

Adult↗