Biomedical subjects

Y Oda

Publications and source records attributed to Y Oda.

At least 19 recordsLinked to original sources

PubMed2007

Sequential regulation of keratinocyte differentiation by 1,25(OH)2D3, VDR, and its coregulators.

Keratinocyte differentiation requires the sequential regulation of gene expression. We have explored the role of 1,25(OH)(2)D(3) and its receptor (VDR) in this process. VDR sequentially binds to coactivator complexes such as Vitamin D receptor interacting protein (DRIP) and steroid receptor coactivator (SRC) during differentiation. Different genes respond differently to the VDR/coactivator complexes as determined by knockdown studies. The binding of DRIP205 and SRC to VDR is ligand (i.e. 1,25(OH)(2)D(3)) dependent. LXXLL motifs in these coactivators are critical for this binding; however, the affinity for VDR of the different LXXLL motifs in these coactivators varies. Hairless is an inhibitor of 1,25(OH)(2)D(3) dependent gene transcription. A phiXXphiphi motif in hairless is crucial for hairless binding to VDR, and its binding is ligand independent. 1,25(OH)(2)D(3) displaces hairless and recruits the coactivators to VDREs. Hsp90 and p23 are chaperone proteins recruited to the DRIP/VDR complex, where they block the binding of the complex to VDREs and block 1,25(OH)(2)D(3) stimulated transcription. Thus four mechanisms explain the ability of 1,25(OH)(2)D(3) to sequentially regulate gene transcription during differentiation: changes in coregulator levels, their differential binding to VDR, differential gene responsiveness to the VDR/coregulator complexes, and chaperone proteins facilitating the cycling of VDR/coregulator complexes on and off the VDREs.

Cell Differentiation↗

PubMed2007

Selection of lactic yeast producing glucosylceramide from cheese whey.

From 2150 isolates from raw milk and milk products, yeast strains were surveyed to produce glucosylceramide from cheese whey. Most of the 54 strains that had accumulated a detectable amount of glucosylceramide were identified as Kluyveromyces lactis var. lactis. The cells of K. lactis var. lactis strain M-11 derived from domestic raw milk accumulated glucosylceramide 2.5-fold higher than K. lactis var. lactis NBRC 1267, the reference strain selected from the culture collections. Strain M-16 of K. lactis var. lactis derived from the same origin was found to synthesize a considerable amount of steryl glucoside in addition to glucosylceramide. Sequence analysis of ribosomal DNA intergenic spacer two regions revealed that strains M-11 and M-16 were diverged from a type strain of K. lactis var. lactis in the same species.

Cheese↗

PubMed2006

Akt-dependent nuclear localization of Y-box-binding protein 1 in acquisition of malignant characteristics by human ovarian cancer cells.

Y-box-binding protein 1 (YB-1), which is a member of the DNA-binding protein family containing a cold-shock domain, has pleiotropic functions in response to various environmental stimuli. As we previously showed that YB-1 is a global marker of multidrug resistance in ovarian cancer and other tumor types. To identify YB-1-regulated genes in ovarian cancers, we investigated the expression profile of YB-1 small-interfering RNA (siRNA)-transfected ovarian cancer cells using a high-density oligonucleotide array. YB-1 knockdown by siRNA upregulated 344 genes, including MDR1, thymidylate synthetase, S100 calcium binding protein and cyclin B, and downregulated 534 genes, including CXCR4, N-myc downstream regulated gene 1, E-cadherin and phospholipase C. Exogenous serum addition stimulated YB-1 translocation from the cytoplasm to the nucleus, and treatment with Akt inhibitors as well as Akt siRNA and integrin-linked kinase (ILK) siRNA specifically blocked YB-1 nuclear localization. Inhibition of Akt activation downregulated CXCR4 and upregulated MDR1 (ABCB1) gene expression. Administration of Akt inhibitor resulted in decrease in nuclear YB-1-positive cancer cells in a xenograft animal model. Akt activation thus regulates the nuclear translocation of YB-1, affecting the expression of drug-resistance genes and other genes associated with the malignant characteristics in ovarian cancer cells. Therefore, the Akt pathway could be a novel target of disrupting the nuclear translocation of YB-1 that has important implications for further development of therapeutic strategy against ovarian cancers.

Animals↗

PubMed2006

A case of an inflammatory myofibroblastic tumor in the lung which expressed TPM3-ALK gene fusion.

We herein describe a 4-year-old boy who after being treated for pneumonia showed an abnormal shadow at the hilus of the right lung on chest X-rays with continued inflammatory findings in his laboratory data. CT and MR investigations suggested the existence of a neoplasm at that site. An open biopsy was thus performed for a definite diagnosis. The histological findings and the expression of TPM3-ALK fusion gene confirmed a diagnosis of an inflammatory myofibroblastic tumor. A right upper and middle lobectomy including the tumor was thus performed for a complete resection. In addition to the histological diagnosis, the detection of the tumor specific fusion gene provided objective evidence in making a diagnosis.

Anaplastic Lymphoma Kinase↗

PubMed2006

Influence of ascorbic acid on bonding of peroxide-affected dentin and 4-META/MMA-TBB resin.

The purpose of this study was to evaluate the tensile bond strength (TBS) to peroxide-exposed dentin. Furthermore, the effect of ascorbic acid (AA) on the bond strength of peroxide-exposed dentin was investigated. Extracted bovine dentin was exposed to 10% carbamide peroxide, 30% hydrogen peroxide, or distilled water for 30 min, then treated with 10% AA (0, 30, 90, and 180 min), and conditioned with 10% citric acid/3% ferric chloride. The polymethyl-methacrylate (PMMA) rod was bonded to the treated bovine dentin with 4-META/MMA-TBB resin. A minidumbbell-shaped bonded specimen was prepared from these bonded assemblies and the TBS was tested. The fractured surfaces were also observed with a scanning electron microscope. Exposure to peroxide before bonding significantly reduced bond strength. The application of AA to the peroxide-exposed dentin increased bond strength. On the other hand, an adverse effect of AA was found in distilled water-affected dentin. Extended resin fibers were partially seen in the peroxide-exposed dentin. In conclusion, peroxide reduced the bond strength, and the stronger the oxidation, the weaker the obtained bond. Antioxidation with AA recovered the bond strength, and this effect increased the longer the AA was applied.

Animals↗

PubMed2006

Simultaneous production of sphingolipids and ethanol by Kluyveromyces thermotolerans.

Kluyveromyces thermotolerans strain NBRC 1674 was selected for the simultaneous production of sphingolipids and ethanol from beet molasses. The strain gradually synthesized ethanol with fermentation periods and attained a level slightly higher than that of the strain of Saccharomyces cerevisiae usually used for ethanol production. The sphingolipids accumulated in the cells were composed of almost equal amounts of free ceramides and glucosylceramides. The sphingoid bases and fatty acids of the two sphingolipids differed from each other and changed under aerobic and anaerobic growth conditions. Oxygen limitation may cause accumulation of sphinganine by inhibiting sphingolipid desaturases and enhance its proportion in both the sphingolipids.

Anaerobiosis↗

PubMed2006

Transthoracic direct current shock facilitates intramyocardial transfection of naked plasmid DNA infused via coronary vessels in canines.

Catheter-mediated, percutaneous, transluminal delivery of naked plasmid DNA (pDNA) into myocardium may offer a valuable strategy to heart diseases. Here, we examined whether clinically available transthoracic direct current (DC) shock improves intracoronary naked DNA transfection into myocardium. Plasmid vector encoding the GL3 luciferase was infused retrogradely into the coronary veins of beagle dogs, whereas another pDNA solution was infused into the left coronary artery. During and after these procedures, the coronary venous sinus was occluded by balloon, and transthoracic DC shock of 200 J was applied immediately after the infusions. Without DC shock, no remarkable increase in luciferase activity was demonstrated in any part of the left ventricular myocardium. In the presence of DC pulsation, significant luciferase expression was detected in the regions that were supplied by left anterior descending coronary artery (LAD), whereas the gene expression in the right coronary artery (RCA) regions was much less drastic. X-gal (5-bromo-4-chloro-3-indolyl-beta-D-galactoside) staining of cardiac cross-sections also revealed regional expression of beta-galactosidase. Immunohistochemical examinations of heart cryosections revealed that cardiomyocytes in LAD regions successfully expressed transgene product. The present system may enable a new strategy for myocardial gene therapy, without any special device or technique other than cardiac catheterization and DC cardioversion that are generally performed in ordinary hospitals.

Animals↗

PubMed2005

Agonist and antagonist dual effect of the cross-linked S19 ribosomal protein dimer in the C5a receptor-mediated respiratory burst reaction of phagocytic leukocytes.

OBJECTIVE: To examine the behavior of the crosslinked dimer of S19 ribosomal protein (RP S19), a natural C5a receptor ligand, in the C5a receptor-mediated respiratory burst reaction of monocytes and neutrophils. METHODS: The respiratory burst reaction of leukocytes was quantitatively observed by continuous spectrophotometric measurement of the reduction of a water-soluble tetrazolium salt, WST-1. RESULTS: The RP S19 dimer induced the respiratory burst of monocytes, but not of neutrophils. Furthermore, in neutrophils, the RP S19 dimer inhibited the reaction induced by C5a, but did not affect the formyl-Met-Leu-Phe-induced reaction. The dimer of a deletion mutant at the C-terminal portion of the RP S19 induced a respiratory burst reaction similar to the one induced by C5a, both in monocytes and neutrophils. Inversely, a chimeric fusion protein between C5a and RPS19, consisting of the addition of the 12 C-terminal amino acid residues of RP S19 after the C-terminal Arg74 of the C5a molecule, behaved similarly to the RP S19 dimer. CONCLUSIONS: The RP S19 dimer works as an agonist and antagonist of the C5a receptor in the monocyte and the neutrophil respiratory burst reactions, respectively. The switch moiety between the antagonist and agonist of the RP S19 dimer for the C5a receptor in the induction of respiratory burst of phagocytes localizes at the C-terminal region of RP S19.

Cross-Linking Reagents↗

PubMed2004

Determination of glucosylceramide contents in crop tissues and by-products from their processing.

Glucosylceramides were surveyed in crop tissues and by-products from their processing. Apple pulp contained the highest amount (0.94 mg g(-1)) of glucosylceramide and relatively less sterylglucoside, which is the major contaminant of partially purified glucosylceramide. Glucosylceramide from apple pulp was principally composed of 2-hydroxypalmitic acid as the fatty acid, 4-hydroxy-cis-8-sphingenine as the sphingoid base, and glucose as the hexose, similar to those of commercial preparations isolated from rice bran or wheat germ. Apple pulp may be an alternative source for the commercial production of glucosylceramides.

Agriculture↗

PubMed2004

The dioxin TCDD protects against aflatoxin-induced mutation in female rats, but not in male rats.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental contaminant and a potent carcinogen in laboratory rodents. When combined with other environmental toxins, it has been shown to increase the (geno)toxicity of some compounds. In this study, the effect of TCDD on the mutagenicity of aflatoxin-B1 (AFB1) was examined in the rat liver using a lacI transgenic rodent mutation assay. AFB1 induces GC-->TA transversions. Since TCDD is known to have a differential effect in male and female rodents, both sexes were studied. The data showed that a 6-week pre-exposure to TCDD had no significant effect on the frequency of aflatoxin-induced mutation in the liver of male rats. However, the TCDD treatment completely prevented the aflatoxin-induced transversion mutations in female animals.

Aflatoxin B1↗

PubMed2004

Analysis of diversity among 3-chlorobenzoate-degrading strains of Rhodopseudomonas palustris.

The phenotypic and genetic characteristics of 14 strains of the purple nonsulfur bacterium Rhodopseudomonas palustris were studied to assess diversity within this species. While all strains had certain phenotypic characteristics in common, including the ability to metabolize benzoate and degrade 2- and 3-chlorobenzoate, there were also significant differences among the strains such as the rate of growth in media containing benzoate as a carbon source. Genetic characterization of the strains revealed there were three divergent lineages in the species. Based on 16S rRNA gene sequences, the 14 strains could be grouped into three distinct clusters (A, B, and C), and this clustering was congruent with that based on gene sequences of form II ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO). Although BOX-PCR genomic DNA fingerprints of all 14 strains exhibited differences, analysis of the fingerprint images and UPGMA/product-moment analysis of similarities showed there were three groupings that were entirely consistent with clusters based on other characteristics of the strains. Thus, regardless of the method of analysis used, strains in groups A and B consistently clustered together and were separate from those of group C. These results suggest that strains in groups A-B and C represent phylogenetically related clones that have diverged from one another. This indicates that at least three lineages of Rhodopseudomonas palustris exist among the strains included in this study, and that each may be particularly well adapted to a distinct ecological niche.

Base Sequence↗

PubMed2004

Calcium and 1,25(OH)2D: interacting drivers of epidermal differentiation.

Both calcium and 1,25(OH)(2)D promote the differentiation of keratinocytes in vitro. The autocrine or paracrine production of 1,25(OH)(2)D by keratinocytes combined with the critical role of the epidermal calcium gradient in regulating keratinocyte differentiation in vivo suggest the physiologic importance of this interaction. The interactions occur at a number of levels. Calcium and 1,25(OH)(2)D synergistically induce involucrin, a protein critical for cornified envelope formation. The involucrin promoter contains an AP-1 site essential for calcium and 1,25(OH)(2)D induction and an adjacent VDRE essential for 1,25(OH)(2)D but not calcium induction. Calcium regulates coactivator complexes that bind to the Vitamin D receptor (VDR). Nuclear extracts from cells grown in low calcium contain an abundance of DRIP(205), whereas calcium induced differentiation leads to reduced DRIP(205) and increased SRC 3 which replaces DRIP in its binding to the VDR. In vivo models support the importance of 1,25(OH)(2)D-calcium interactions in epidermal differentiation. The epidermis of 1alphaOHase null mice fails to form a normal calcium gradient, has reduced expression of proteins critical for barrier function, and shows little recovery of the permeability barrier when disrupted. Thus in vivo and in vitro, calcium and 1,25(OH)(2)D interact at multiple levels to regulate epidermal differentiation.

Calcium↗

PubMed2004

Comparative study of gene expression of cholinergic system-related molecules in the human spinal cord and term placenta.

By reverse transcription-polymerase chain reaction, Southern blot analysis, direct sequencing, and immunohistochemistry, we studied the expression of cholinergic neuronal markers (choline acetyltransferase [ChAT], vesicular acetylcholine transporter [VAChT], and a high-affinity choline transporter [CHT1]), and gene regulatory molecules (repressor element-1 silencing transcription factor/neuron-restrictive silencer factor [REST/NRSF] and CoREST) in the human spinal cord and term placenta, both of which are well known to contain cells synthesizing acetylcholine. H-type, M-type, N2-type, and R-type ChAT mRNAs, VAChT mRNA, and CHT1 mRNA were detected in the spinal cord, but only H-type, M-type, and N2-type ChAT mRNAs, in the term placenta. REST/NRSF and CoREST were detected in the spinal cord and the placenta, but the amounts of both mRNAs were greater in the placenta than in the spinal cord. Further microdissection analyses revealed that the placental trophoblastic cells contained more REST/NRSF and CoREST transcripts than the spinal large motor neurons. Large motor neurons in the anterior horn of the spinal cord were immunohistochemically stained for ChAT and VAChT. In the placenta, stromal fibroblasts, endothelial cells, and trophoblastic cells of the chorionic villi were positively stained with anti-ChAT antibody but not with anti-VAChT antibody. These findings suggest that transcriptions of the R-type ChAT and VAChT mRNAs are coordinately suppressed in the human term placenta, which might be regulated in part by a REST/NRSF complex that binds to a consensus sequence of repressor element 1/neuron-restrictive silencer element (RE1/NRSE) in the 5' region upstream from exon R, whereas transcriptions of the H-type, M-type, and N2-type ChAT mRNAs might be independent of control by RE1/NRSE. It is possible that at least two separate regulatory mechanisms of gene expression are present for the human cholinergic gene locus, which might be selected by different combinations of DNA motifs and binding proteins to function in neuronal and non-neuronal cells.

Acetylcholine↗

PubMed2004

Low-grade fibromyxoid sarcoma versus low-grade myxofibrosarcoma in the extremities and trunk. A comparison of clinicopathological and immunohistochemical features.

AIMS: Low-grade fibromyxoid sarcoma (LGFMS) is a distinctive variant of fibrosarcoma and has been reported to have metastatic potential despite its low-grade histological findings. Low-grade myxofibrosarcoma (MFS) is an important differential diagnosis of LGMFS, because it shows different biological behaviour. Of 75 MFSs in the extremities and trunk, we defined 22 grade 1 tumours as low-grade MFS according to the French Federation of Cancer Centres grading system and compared the clinicopathological factors and immunohistochemical expression of cell cycle regulators with those of 11 LGFMSs. METHODS AND RESULTS: The two entities could be distinguished on histological grounds. Low-grade MFS was characterized by the presence of prominent elongated, curvilinear capillaries and pseudolipoblasts, accompanied by an abundant myxoid matrix. It had no extensive solid areas. LGFMS was composed of bland spindle cells arranged in a whorled pattern with alternating myxoid and fibrous stroma. Curvilinear capillaries were not prominent and cytological atypia was absent. No tumour necrosis was observed in any of the 11 LGFMSs, whereas only one case showed tumour necrosis in less than 50% of the tumour in 22 low-grade MFSs. The patients with low-grade MFS were significantly older than those with LGFMS (low-grade MFS average, 60.1 years; LGFMS average, 31.5 years; P < 0.0001) and low-grade MFS occurred more frequently in a superficial location (low-grade MFS 14/20; LGFMS 2/11; P = 0.0077). As for cell cycle regulator expression, the MIB-1 labelling index (LI) (14.76 on average) and cyclin E LI (11.55 on average) in low-grade MFS were significantly higher than those (MIB-1 LI, 4.68 on average; cyclin E LI, 3.38 on average) of LGFMS, while p21 LI (25.53 on average) and p27 LI (42.68 on average) in low-grade MFS were significantly lower than those (p21 LI, 42.74 on average; p27 LI, 57.28 on average) of LGFMS. CONCLUSIONS: We conclude that low-grade MFS and LGFMS are distinctly different clinicopathological entities and the assessment of the immunohistochemical expression of MIB-1, cyclin E, p21 and p27 as well as conventional clinicopathological features may be helpful to distinguish low-grade MFS from LGFMS.

Adolescent↗

PubMed2004

Mechanical properties of cast Ti-6Al-4V-XCu alloys.

The mechanical properties of Ti-6Al-4V-XCu (1, 4 and 10 wt% Cu) alloys were examined. The castings for each alloy were made in a centrifugal titanium casting machine. Two shapes of specimens were used: a dumbbell (20 mm gauge length x 2.8 mm diameter) for mechanical property studies, and a flat slab (2 mm x 10 mm x 10 mm) for metallography, microhardness determination and X-ray diffractometry. Tensile strength, yield strength, modulus of elasticity, elongation and microhardness were evaluated. After tensile testing, the fracture surfaces were observed using scanning electron microscopy. The tensile strengths of the quaternary alloys decreased from 1016 MPa for the 1% Cu alloy to 387 MPa for the 10% Cu alloy. Elongation decreased with an increase in the copper content. The 1% Cu alloy exhibited elongation similar to Ti-6Al-4V without copper (3.0%). The results also indicated that the copper additions increased the bulk hardness of the quaternary alloy. In particular, the 10% Cu alloy had the highest hardness and underwent the most brittle fracture. The mechanical properties of cast Ti-6Al-4V alloy with 1 and 4% Cu were well within the values for existing dental casting non-precious alloys.

Alloys↗

PubMed2003

Role of the pectinolytic enzyme in the lactic acid fermentation of potato pulp by Rhizopus oryzae.

Rhizopus oryzae strain NBRC 4707 produced lactic acid and ethanol more efficiently than strain NRRL 395 in potato pulp, an agricultural by-product of the starch industry. The two strains developed comparable activities of xylanase, cellulase, alpha-amylase, and glucoamylase, while the polygalacturonase activity of strain NBRC 4707 was double that of strain NRRL 395. The addition of commercial pectinase enhanced the formation of metabolites, suggesting that the degradation of pectic substances determines the fermentation of potato pulp by R. oryzae. Orange and apple peel were more effective in the induction of polygalacturonase activity than potato pulp, sugarbeet pulp, or wheat bran when used as a principal carbon source for fungal growth in a solid-state culture. The fungal cells in both types of fruit peel stimulated the fermentation of potato pulp and increased the quantity of lactic acid and ethanol to higher levels than those in other agricultural by-products.

Citrus sinensis↗

PubMed2003

Effects of multigrooved surfaces on fibroblast behavior.

Microgrooves have been investigated as substrates for the control of cell alignment. However, they are relatively too narrow and shallow for controlling the orientation of extracellular matrices (ECM) such as collagen. Multigrooves, a combination of microgrooves and macrogrooves, are expected to be able to control the orientation of both cells and ECM. This study investigated a method for fabricating multigrooves and evaluated fibroblast behavior on these novel surfaces. Multigrooved patterns were fabricated on a gold-alloy metal die, in which 90-degree V-shaped microgrooves with a 2-microm pitch were cut on trapezoidal macrogrooves. The macrogrooves had a 50- microm ridge width, a 50-microm wall width, a 50-microm bottom width, and a 25-microm depth. The grooves were made by an ultraprecision micromachine using a single crystal diamond. This metal die served as a template for making surface replicas from polystyrene. Microgrooved and smooth polystyrene replicas also were prepared as comparative substrates. Mouse fibroblast L929 cells were cultured in each type of replica substrate for 7 to 21 days. After these periods, the cells were fixed with 2.5% glutaraldehyde, treated with conventional methods, and, finally, observed by SEM. Confocal laser scanning microscopy was performed to investigate ECM formation. The multigrooved metal die exhibited the desired sharp configuration without defects. The dimensional values of the multigrooves on the polystyrene replicas were almost the same as the designed values. The fibroblasts on the multigrooved and microgrooved substrates were aligned parallel to the surface grooves after 7 days of incubation. In contrast to the microgrooved and flat surfaces, a dense extracellular matrix was produced along the multigrooves after 21 days of incubation. These results suggest that multigrooves can control the orientation of ECM as well as cells and thus enhance the production of ECM.

Animals↗

PubMed2003

Sporadic Creutzfeldt-Jakob disease with MM1-type prion protein and plaques.

The authors report a 75-year-old woman with atypical sporadic Creutzfeldt-Jakob disease (CJD) characterized by MM1-type prion protein (PrP) (methionine homozygosity at codon 129 in the PrP gene and type-1 protease-resistant PrP) and PrP plaques. This patient is the first case of sporadic CJD with plaque-forming MM1-type PrP, suggesting either a shared prion strain with the plaque-forming subset of dural graft-associated CJD or shared host genetic factors that are unrelated to the PrP genotype.

Aged↗