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Y Oda

Publications and source records attributed to Y Oda.

At least 325 records · Page 18Linked to original sources
PubMed1996

[A pediatric case of cerebral infarction following minor head injury presenting interesting neuroradiological findings].

We reported a case of juvenile cerebral infarction following minor head injury. The patient, a 12-year-old girl, developed right hemiparesis and aphasia almost immediately after having fallen from about 1 meter height during the exercise class at school. CT and MRI study showed lacunar lesions bilaterally and almost symmetrically in the paraventricular deep white matter on both sides. A new stroke area, responsible for the symptoms, was recognized about 24 hours later on CT scan just next to the lacuna of the left side. Although angiography revealed a rare anomaly of the right side aortic arch, associated with subclavian steal phenomenon, presumably of congenital in nature, no abnormality was found in the intracranial vessels. She made a rapid recovery during her hospital stay and showed no more than a slight motor weakness in her right upper extremity on discharge. The literature was reviewed on the embryology of the aortic arch and brachiocephalic arteries. We speculate that the lacunar lesions found bilaterally are dilated large normal Virchow-Robin space, and the pathogenesis of the stroke in this patient was discussed.

Cerebral Infarction↗
PubMed1996

Intraoperative continuous epidural lidocaine for early postoperative analgesia.

We determined the early postoperative analgesia using intraoperative continuous epidural infusion of lidocaine during general anesthesia in patients undergoing upper abdominal surgery in a prospective double-blind manner. After insertion of an epidural catheter at the T10-T11 interspace, general anesthesia was induced. Thirty patients were randomly allocated to receive continuous epidural infusion of either 0.5% (n = 15) or 1% (n = 15) plain lidocaine at 10 ml/hr. The infusion was continued from 10 to 15 minutes before surgery until the end of surgery. Visual analog pain scale (0-10) within 30 minutes after the end of surgery was significantly lower in the 1% lidocaine group (5.6 +/- 0.9, mean +/-SE) than in the 0.5% lidocaine group (8.2 +/- 0.8), however, it was unsatisfactory in both groups. Plasma concentrations of lidocaine and its principal metabolite, monoethylglycinexylidide, gradually increased through epidural infusion, but remained below the toxic range in both groups. We conclude that continuous epidural lidocaine during general anesthesia offered limited analgesia in the early postoperative period.

Aged↗
PubMed1996

Surface reaction between titanium castings and investments.

The selection of investments suitable for titanium castings is critical because the surface-reacted layer greatly affects their mechanical properties. This study analyzed the interfacial zone of titanium castings obtained from various commercial investments and examined the relationship between the surface-reacted layer and the hardness. CP titanium disks (20 mm diameter, 1 mm thick, n = 5) were cast using eight commercial casting systems and investments for titanium casting: two alumina-based investments (T-invest, CD-titan investment), two spinel-based investments (Titanmold, Titavest MZ), three zirconia-based investments (Asahivest-D, Titaniumvest EX, Tycast investment TM), and a magnesia-based investment (Selevest CB). The Vickers hardness of cast disks in cross-section was tested at 50 microns intervals from the surface to 0.5 mm in depth. The cross-section was observed metallurgically, and an elemental mapping measurement of the reacted layer was conducted under the EPMA. The Vickers hardnesses at 50 microns from the surface of the specimens ranged 312 to 624 and were significantly different among the investments (p < 0.01). The thickness of the reacted layer, rich in O, Si, Al, Zr, Mg, and P, ranged from 10 to 60 microns. No correlation was seen between the thickness of reacted layer and the hardness (p > 0.05). However, the specimens cast with alumina-based and zirconia-based investments were harder than the spinel-based and magnesia-based investments at 500 microns. Although the free energies of metal oxide formation of alumina and zirconia were lower than titania, these data suggest that silica, alumina and zirconia were reduced by contact with molten titanium. Accordingly, silicon, aluminum and zirconium diffused to the interior of the titanium castings and changed their mechanical properties.

Aluminum Oxide↗
PubMed1995

Quantitation of platelet-activating factor in biological samples using liquid chromatography/mass spectrometry with column-switching technique.

A procedure is described for the fully automated quantitative determination of platelet-activating factor (PAF) using liquid chromatography/fast atom bombardment mass spectrometry (LC/FAB-MS) with two types of column-switching techniques. Various parameters in LC/FAB-MS were optimized, and the use of a microbore column allowed highly selective detection of PAF. A column-switching system was incorporated to minimize band broadening and to increase the permissible injection volume. Analysis of authentic PAF indicated that the limit of quantitation was at the low picogram level (about 50 pg/ml). Another system using both a strong cation-exchange column and an ODS column in tandem was developed for the analysis of PAF in blood samples. These methods were validated with standard samples and applied to the determination of PAF in human polymorphonuclear neutrophils stimulated by addition of a calcium ionophore and in human blood.

Chromatography, Liquid↗
PubMed1995

Direct determination of E2020 enantiomers in plasma by liquid chromatography-mass spectrometry and column-switching techniques.

High-performance liquid chromatography with column switching and mass spectrometry (MS) was applied to the on-line determination and resolution of the enantiomers of E2020 (acetylcholinesterase inhibitor) in plasma. This system employs two avidin columns and fast atom bombardment (FAB)-MS. A plasma sample was injected directly into an avidin trapping column (10 mm x 4.0 mm I.D.). The plasma protein was washed out from the trapping column immediately while E2020 was retained. After the column-switching procedure, E2020 was separated enantioselectivity in an avidin analytical column. The separated E2020 enantiomers were specifically detected by FAB-MS without interference from metabolites of E2020 and plasma constituents. The limit of quantification for each enantiomer of E2020 in plasma was 1.0 ng/ml and the intra- and inter-assay relative standard deviations for the method were less than 5.2%. The assay was validated for enantioselective pharmacokinetic studies in the dog.

Animals↗
PubMed1995

Immunohistochemical detection of p53 in cervical epithelial lesions with or without infection of human papillomavirus types 16 and 18.

Using formalin-fixed and paraffin-embedded cervical tissues, we examined infection with human papillomavirus (HPV) types 16 and 18 by Southern blot analysis following polymerase chain reaction (PCR), and the accumulation of p53 protein by immunohistochemistry in 30 cases of normal or metaplastic cervix, 17 cases of cervical intraepithelial neoplasia grade I (CIN I), 20 cases of CIN II, 37 cases of CIN III and 23 cases of invasive squamous cell carcinoma (ISCC). In addition, we examined the ratio of HPV-infected cells by in situ hybridization (ISH) and the alteration of p53 gene using PCR followed by single-strand conformation polymorphism (PCR-SSCP) in 2 cases of CIN III and 12 cases of ISCC, in which overexpression of p53 was immunohistochemically detected. HPV DNA was detected in 5 cases (16.7%) of normal or metaplastic cervix, 5 cases (29.4%) of CIN I, 9 cases (45.0%) of CIN II, 26 cases (70.3%) of CIN III and 15 cases (65.2%) of ISCC. Positivity for HPV in the groups of CIN III and ISCC was significantly higher than in the normal or metaplastic cervix (P < 0.05). The accumulation of p53 was not detected in the normal or metaplastic cervix, CIN I and CIN II. High-level p53 accumulation was identified in basal and suprabasal atypical cells in 27.0% (10/37) of CIN III and in carcinoma cells in 43.5% (10/23) of ISCC cases, and low-level accumulation was identified in atypical cells of 35.1% (13/37) of CIN III and in carcinoma cells in 30.4% (7/23) of ISCC cases. The accumulation of p53 was found to coexist with infection by HPV in 17 (46.0%) of 37 CIN III cases and 12 (52.2%) of 23 ISCC cases, and high-level p53 accumulation was more frequently detected in HPV-positive ISCC cases. Either HPV infection or accumulation of p53 was found in 16.7% (5/30) of the cases of normal or metaplastic cervix, 29.4% (5/17) of CIN I, 45.0% (9/20) of CIN II, 86.5% (32/37) of CIN III and 87.0% (20/23) of ISCC cases. These results suggest that the inactivation of p53 function by HPV infection or alteration of p53 protein itself precedes the development of tumours with a fully malignant and invasive phenotype and plays an important role in tumorigenesis in the uterine cervix. ISH study provided no correlation between the degree of immunohistochemical positivity for p53 and the ratio of HPV-positive cells in the same lesions.(ABSTRACT TRUNCATED AT 400 WORDS)

Base Sequence↗
PubMed1995

Molecular genetic properties of the yeast Torulaspora pretoriensis: characterization of chromosomal DNA and genetic transformation by Saccharomyces cerevisiae-based plasmids.

Chromosomal DNA banding patterns were obtained for three strains of Torulaspora pretoriensis by contour-clamped homogeneous-electric-field gel electrophoresis. Chromosomes were resolved into six or seven bands in the range of 800 to 2000 kb, and a polymorphism of these lengths was observed. By Southern-blot analysis, the three strains were shown to lack the DNA sequences homologous to the URA3, LEU2, TRP1, and HO genes of Saccharomyces cerevisiae. A uracil auxotrophic mutant derived from T. pretoriensis was transformed with three plasmids (YEp24, YRpHI, and YCp50) carrying the URA3 gene of S. cerevisiae by the lithium acetate method.

Blotting, Southern↗
PubMed1995

Immunohistochemical analysis of nm23 protein expression in malignant bone tumors.

Expression levels of nm23 protein in 72 malignant bone tumors comprising 41 osteosarcomas, 22 chondrosarcomas, 6 Ewing's sarcomas, and 2 malignant fibrous histiocytomas were examined immunohistochemically, using anti-nm23 protein polyclonal antibody, and compared with 51 cases of benign bone tumors or tumor-like lesions. Malignant bone tumors showed significantly higher nm23 protein expression than benign bone tumors or tumor-like lesions (P < 0.0001). In chondrosarcoma, nm23 expression increased in high-grade tumors (grade I versus grade II and III: P = 0.0229). In the cases of osteosarcoma, however, grade IV osteosarcomas showed decreased expression of nm23 compared with grade III tumors (P = 0.0122). There was no significant relationship between nm23 expression and histological type. nm23 expression had no correlation with metastatic potential in osteosarcoma, although the therapy was not uniform in our cases. Furthermore, in 6 cases of osteosarcoma and 1 case of Ewing's sarcoma, there was no clear tendency for a decrease of nm23 in the metastatic sites compared with primary sites, as reported in breast cancer. These results showed that, in contrast to reports on breast cancer and experimental models, nm23 protein expression in human bone tumors may be associated with malignant potentiality, except in cases of osteosarcoma.

Adolescent↗
PubMed1995

Effect of selenium on malignant tumor cells of brain.

Some reports have demonstrated that selenium can inhibit tumorigenesis in some tissues of animal. However, little is known about the inhibitory effect on malignant tumor cells of brain. The purpose of our study was to determine the biological effect of selenium on growth of rat glioma and human glioblastoma cell lines. Cell lines C6 and A172 were obtained from Japanese Cancer Research Resources Bank, Tokyo, Japan (JCRB). Cells were cultured in Dulbecco's Modified Eagle's Medium (DMEM) supplemented with 10% fetal calf serum at 37 degrees C in a humidified atmosphere of air and 5% CO2. Antiproliferative effects of selenium were evaluated using growth rate assay quantifying cell number by MTT assay. An antiproliferative effect of selenium was found in two cell lines, which was more effective on human A172 glioblastoma and less effective on rat C6 glioma.

Animals↗
PubMed1995

Effects of propranolol and atenolol on immobilization stress-induced hypertension and down-regulation of central beta-adrenoceptors in rats.

Effects of chronic treatment with propranolol or atenolol on stress-induced changes in blood pressure, body weight, and cerebral beta-adrenoceptors in rats were examined and compared with the effects of chronic treatment with prazosin. Immobilization stress (2 h daily for 2 weeks) induced a moderate elevation of blood pressure, loss of body weight gain, and downregulation of cerebral beta-adrenoceptors, but produced no changes in the cerebral alpha 1-adrenoceptors. Chronic administration of propranolol (5 or 50 mg.kg-1), atenolol (5 or 50 mg.kg-1) or prazosin (2 or 20 mg.kg-1) inhibited stress-induced hypertension but did not affect loss of body weight gain. Propranolol increased the density of cerebral beta-adrenoceptors by 77% and reduced the downregulation induced by stress. Atenolol also increased the density of cerebral beta-adrenoceptors by 34% and abolished the stress-induced downregulation in cerebral beta-adrenoceptor density. In contrast, prazosin had no effect on the cerebral beta-adrenoceptors in nonstressed or stressed rats. These results suggest that the antihypertensive action of propranolol and atenolol may be partly associated with the inhibition of stress-activated central beta-adrenoceptor transmission.

Adrenergic beta-Antagonists↗
PubMed1995

Development of high sensitive umu test system: rapid detection of genotoxicity of promutagenic aromatic amines by Salmonella typhimurium strain NM2009 possessing high O-acetyltransferase activity.

A highly sensitive umu test system for the detection of carcinogenic/mutagenic aromatic amines has been developed utilizing a new tester strain, Salmonella typhimurium NM2009, possessing an elevated O-acetyltransferase (O-AT) level. NM2009 was constructed by subcloning the bacterial O-AT gene into a plasmid vector pACYC184 and introducing the plasmid into the original strain S. typhimurium TA1535/pSK1002 harboring an umuC'-'lacZ fusion gene. The system is based on the ability of DNA-damaging agents (genotoxins) to induce umuC gene expression and monitored by measuring the cellular beta-galactosidase activity evoked by the fusion gene. Twenty-two aromatic amine compounds including arylamines, aminoazo dyes, and heterocyclic aromatic amines were tested for inducibility of DNA damage after metabolic activation by rat liver S9 in strain NM2009 and the sensitivity was compared with those of the parent strain TA1535/pSK1002 and the O-AT-defective strain NM2000. NM2009 had about 400 times higher O-AT activity than the parent strain. It was found that NM2009 was much more sensitive to aromatic amines than other strains to induce umuC gene expression after metabolic activation; the chemicals which were extremely sensitive in strain NM2009 include 2-aminoanthracene, 2-aminofluorene, 2-acetylaminofluorene, benzidine, 6-aminochrysene, 2,4-diaminotoluene, 2,6-diaminotoluene, 1-naphthylamine, o-tolidine, 3-MeO-AAB, o-aminoazotoluene, Glu-P-1, Trp-P-1, MeA alpha C, A alpha C, MeIQ, MeIQx, and IQ. In contrast, Trp-P-2 and PhIP showed almost similar sensitivities in three tester strains used in this study. These results suggest that strain NM2009 with high O-acetyltransferase activity is very useful to detect the genotoxic activities of potential mutagenic aromatic amine compounds, which require metabolic activation via the cytochrome P-450/acetyltransferase system.

Acetyltransferases↗
PubMed1995

Inhibitory effect of curcumin on SOS functions induced by UV irradiation.

The antigenotoxic effects of curcumin, including the inhibition of SOS induction and mutagenesis by UV light, were investigated in Salmonella typhimurium TA1535/pSK1002 and Escherichia coli K-12 strains. Induction of the SOS gene (umuC) expression was assayed by measuring accumulated beta-galactosidase activity. We found that curcumin blocked umuC induction promoted by UV irradiation in a dose-dependent manner. Also, with another SOS response, Weigle reactivation, we observed that curcumin effectively inhibited phage reactivation by UV irradiation. Furthermore, we tested the effect of curcumin on UV mutagenesis. We showed that mutagenesis induced by UV irradiation was suppressed by the addition of curcumin. Together these results indicate that curcumin acts as an inhibitor of SOS functions including UV mutagenesis.

Antimutagenic Agents↗
PubMed1995

Peptides inhibit selectin-mediated cell adhesion in vitro, and neutrophil influx into inflammatory sites in vivo.

The selectins are cell adhesion molecules whose carbohydrate-binding domain (C-type lectin) is thought to be involved in leukocyte adhesion to activated vascular endothelium in the inflammatory process. A series of peptides, based on a conserved region (48YYWIGIRK55-NH2) of the lectin domain of E-, L- and P-selectins, were analysed for their ability to block selectin-mediated cell adhesion in vitro, and neutrophil infiltration into sites of inflammation in vivo. The peptides inhibited the adhesion of myeloid cells to recombinant forms of E- and P-selectin. The adhesion of myeloid cells to human endothelial cells, stimulated to express E-selectin, was also inhibited by the peptides. Finally, the peptides blocked the adhesion of lymphocytes, expressing L-selectin, to high endothelial venules in lymph nodes which contain the ligand for L-selectin. A clear structure-activity relationship was established when peptides of different amino acid chain lengths were tested in these assays. Peptides lacking tyrosine residues (e.g. WIGIR-NH2) at their amino terminus were poor inhibitors of selectin-mediated cell adhesion in vitro. The peptides that were found to be inhibitors of cell adhesion in vitro were also found to inhibit (up to 70%) neutrophil infiltration into sites of inflammation in a thioglycollate-induced peritonitis mouse model system. They also significantly reduced (> 50%) the migration of neutrophils into cytokine-treated skin. These results strongly suggest that compounds based on these tyrosine-containing, selectin-derived peptides could be used as anti-inflammatory therapeutic agents.

Amino Acid Sequence↗
PubMed1995

Metabolism of a new local anesthetic, ropivacaine, by human hepatic cytochrome P450.

BACKGROUND: Ropivacaine is a local anesthetic with a long duration of action. Although it is less toxic than bupivacaine, local anesthetic toxicity is possible when the plasma concentration is increased. Because ropivacaine is an amide-type local anesthetic, it is metabolized by cytochrome P450 (P450) in the liver, and its elimination and plasma concentration can be dependent on the level of P450. The purpose of this investigation was to elucidate the metabolism of ropivacaine by human hepatic P450. METHODS: The metabolism of ropivacaine was compared using recombinant human and purified rat hepatic P450 isozymes. An inhibition study using antibodies against rat P450 was performed using hepatic microsomes from human and rat to identify which P450s are involved in ropivacaine metabolism. RESULTS: Ropivacaine was metabolized to 2',6'-pipecoloxylidide (PPX), 3'-hydroxyropivacaine (3'-OH Rop), and 4'-hydroxyropivacaine (4'-OH Rop) by hepatic microsomes from human and rat. PPX was a major metabolite of both human and rat hepatic microsomes. In a reconstituted system with rat P450. PPX was produced by CYP2C11 and 3A2, 4'-OH Rop by CYP1A2, and 3'-OH Rop by CYP1A2 and 2D1. Formation of PPX in rat hepatic microsomes was inhibited by anti CYP3A2, but not by CYP2C11 antibody, and formation of 3'-OH Rop was inhibited by CYP1A2 and 2D1 antibodies. Anti CYP3A2 and 1A2 antibodies inhibited the formation of PPX and 3'-OH Rop in human hepatic microsomes, respectively. Recombinant human P450s expressed in lymphoblast cells were used for further study. CYP3A4 and 1A2 formed the most PPX and 3'-OH Rop, respectively. Ropivacaine N-dealkylation and 3'-hydroxylation activities correlated well with the level of CYP3A4 and 1A2 in human hepatic microsomes, respectively. CONCLUSIONS: Ropivacaine was metabolized to PPX, 3'-OH Rop, and 4'-OH Rop by hepatic P450. PPX was a major metabolite in human hepatic microsomes. CYP3A4 was involved in producing PPX. CYP1A2 was involved in the formation of 3'-OH Rop in human hepatic microsomes.

Amides↗
PubMed1995

The monoethylglycinexylidide test is more useful for evaluating liver function than indocyanine green test: case of a patient with remarkably decreased indocyanine green half-life.

Lidocaine was used for evaluation of hepatic function in a patient undergoing hepatic resection. Preoperatively, half-life of indocyanine green (ICG) was 33 min after intravenous administration. Plasma concentration of the N-dealkylated metabolite of lidocaine, monoethylglycinexylidide (MEGX), was quantitatively determined to evaluate hepatic function. The patient's rate of formation of MEGX at 15 min after administration of lidocaine was within normal limits, at 56 micrograms/L. These findings suggest that in this patient, hepatic cytochrome P-450IIIA activity was not impaired, but selective impairment of uptake of ICG into hepatocytes or excretion into the bile ducts was present. The rate of formation of MEGX was decreased, and plasma concentration of bilirubin was elevated postsurgically; this could have been the result of decreased cytochrome P-450IIIA activity or decreased hepatic blood flow after hepatic resection. We conclude that the rate of formation of MEGX is a better index of hepatic function than is ICG half-life.

Humans↗
PubMed1995

Expression of integrin alpha 3 in gastric and colorectal cancers: its relation to wall contraction and mode of invasion.

We macroscopically classified 25 gastric and 23 colorectal advanced cancers into "contracted" and "uncontracted" types, and found immunohistochemically that integrin subunit alpha 3 was more frequently expressed in the extracellular matrix (ECM) in the former than in the latter (75%:9/12 vs. 38%: 5/13 in gastric and 86%:6/7 vs. 25%:4/16 in colorectal cancers, respectively). Integrin subunit alpha 3 was also expressed more frequently in cancers producing transforming growth factor-beta (TGF-beta), which is related to ECM deposition, integrin expression and cell mobility, than in those which did not produce TGF-beta (67%:10/15 vs. 40%:4/10 in gastric and 57%:4/7 vs. 38%:6/16 in colorectal cancers, respectively). In addition, integrin subunit alpha 3 was not expressed in 2 benign gastric ulcers combined with gastric cancer elsewhere in the stomach. On the other hand, a retrospective analysis of 107 cases of rectal cancer which recurred after a curative operation revealed that local recurrence was more frequent in "contracted" than "uncontracted" types (44%:11/25 vs. 26%:21/82). These results may suggest that the abundant interstitial fibrosis which leads to remarkable gastric or colorectal wall contraction is a result of the interaction between cancer cells and ECM, along with the expression of integrin and/or the production of TGF-beta. This fibrosis may also be closely related to the mode of gastric and colorectal cancer invasion.

Antigens, CD↗