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M Ueda

Publications and source records attributed to M Ueda.

At least 73 records · Page 4Linked to original sources
PubMed2003

Mild hypothermia enhances the neuroprotective effects of a selective thrombin inhibitor following transient focal ischemia in rats.

The aim of this study is to determine whether a selective thrombin inhibitor, Argatroban, would prevent neuronal cell death and whether extra-mild hypothermia (35 degrees C) would enhance the neuroprotective effect of a selective thrombin inhibitor following transient focal ischemia in rats. Sprague-Dawley rats were subjected to MCAo using an intraluminal suture technique for 2 hrs. The rats were reperfused for 24 h and decapitated for infarct and edema analysis. Argatroban-treated animals received a continuous injection of argatroban (3.0 mg/kg) for 24 hrs after onset of ischemia, while vehicle-treated groups received same dose of vehicle. During ischemia, temporal muscle and rectal temperatures were monitored and maintained at 37 degrees C in the normothermic animals and at 35 degrees C in the hypothermic animals. Argatroban ameliorated the cortical ischemic damage significantly (p < 0.05). Moreover, argatroban with mild hypothermia decreased the cortical infarct or edema volume significantly compared with those of groups I and III (p < 0.05). Argatroban improved neurological symptoms significantly and also improved survival rate. These results demonstrate that extra-mild hypothermia (35 degrees C) enhances neuroprotective effects of a selective thrombin inhibitor, argatroban, suggesting that this combined therapy may be a new therapeutic strategy for the treatment of acute stroke.

Animals↗
PubMed2003

Diurnal T2 value changes in the lumbar intervertebral discs.

AIM: To investigate if there is any in vivo diurnal T2 value changes in the nucleus pulposus in normal and degenerated lumbar intervertebral discs. MATERIALS AND METHODS: Eighteen volunteers (16 men, two women) with no symptoms related to lumbar disease were imaged in the morning before beginning daily work and in the evening after finishing work. Sagittal fast spin-echo T2-weighted images were obtained, following spin-echo transverse imaging for T2 analysis. RESULTS: The normal disc group (n=71) showed statistically significant diurnal T2 value changes (p<0.001), whilst the degenerating disc group (n=19) showed no significant diurnal changes. The normal disc group up to age 34 years showed statistically significant diurnal T2 value changes. However no significant changes were demonstrated after the age 35 years. CONCLUSION: Statistically significant diurnal T2 value changes in the normal lumbar intervertebral discs were demonstrated. Disappearance of the diurnal T2 value changes in the normal discs after the age 35 years was revealed for the first time and thought to be an aspect of aging, not caused by degeneration.

Adult↗
PubMed2003

Monosegmental living donor liver transplantation.

BACKGROUND: Living donor liver transplant (LDLT) program has been started from 1990 in Japan, and is still major form of liver transplantation because of the scarcity of cadaveric donor organs. In small infants, implantation of left lateral segment grafts can be a problem because of a large-for-size graft. Until November 2002, we performed 867 transplants for 828 patients (561 children and 306 adults), and 14 cases received monosegment grafts from living donors. METHODS: Fifteen patients, median age 211 days, median weights 5.95 kg, received monosegmental LDLT. The indication for using this technique was infants with an estimated graft-to-recipient weight ratio of over 4.0%. RESULTS: Graft and patient survival is 85.7%. There were no differences in donor operation time and blood loss between monosegmentectomy and left lateral segmentectomy. Segment III grafts were indicated in 13 cases. Two vascular complications were observed (one hepatic artery thrombosis and one portal vein thrombosis). CONCLUSIONS: Monosegental living donor liver transplantation is a feasible option with satisfactory graft survival in small babies with liver failure.

Body Weight↗
PubMed2003

Rat costochondral cell characteristics on poly (L-lactide-co-epsilon-caprolactone) scaffolds.

This study was designed to examine the adhesion, proliferation, and morphology of chondrocytes on new scaffolds; and to examine these cells histologically for the ability of the chondrocytes to maintain chondrogenic properties after subcutaneous implantation into nude mice. Both 75:25 poly (L-lactide-co-epsilon-caprolactone) (75PLC) and 50:50 poly (L-lactide-co-epsilon-capro-lactone) scaffold (50PLC) were tested as a scaffold for rat costochondral resting zone chondrocytes in comparison with a type I collagen sponge scaffold (collagen scaffold). Both of the poly (L-lactide-co-epsilon-caprolactone) scaffolds (75PLC and 50PLC) were coated with type I collagen solution and the effects of the collagen coat (hybrid-PLC) were also examined. The hybrid-75PLC bound the same number of cells as the collagen scaffold, whereas the 75PLC and the 50PLC bound 60% and 50% fewer cells than the collagen scaffold, respectively. The cell growth on the scaffolds progressed with culture time in all scaffolds. Cell morphology was assessed by scanning electron microscopy for differences in the structure of cellular interaction. Chondrocytes on every scaffold maintained a spherical shape. The hybrid-PLCs were superior to the PLCs with respect to the number of cells attached. The PLCs had an advantageous degradation characteristic in that they retained their original shape better than the collagen scaffold. Additionally, in the PLCs seeded, the cells retained their integrity 4 weeks after implantation, although the volume of collagen scaffold decreased by 50%.

Animals↗
PubMed2003

Identification of a bisegmented double-stranded RNA virus (picobirnavirus) in calf faeces.

To determine the incidence of rotavirus infection among dairy herds in the State of São Paulo, Brazil, 576 faecal samples obtained from calves aged 1-45 days with and without diarrhoea, reared on 63 dairy cattle farms, were analyzed. Polyacrylamide gel electrophoresis (PAGE) identified 28 samples positive for group A rotavirus, while four samples, two diarrhoeic and two non-diarrhoeic, showed a bisegmented genome with a typical picobirnavirus pattern. Electron microscopy revealed spherical virus particles with a diameter of 37 nm and without a defined surface structure. The present study is the first report of a bisegmented virus identified in cattle in Brazil.

Animals↗
PubMed2003

Involvement of EGF receptor activation in the induction of cyclooxygenase-2 in HaCaT keratinocytes after UVB.

Because selective inhibition of cyclooxygenase-2 (COX-2) suppressed the induction of skin tumors in mice by UV and as UV has been shown to induce expression of COX-2 in skin and cells, COX-2 may be crucial for photocarcinogenesis of the skin. We studied the mechanism of UVB-induced expression of COX-2 focusing on the signal transduction pathway involved. Hydrogen peroxide (H2O2) treatment of HaCaT cells induced expression of COX-2 and pretreatment with the antioxidant N-acetylcysteine (NAC) partly inhibited the UVB-induced expression of COX-2 protein in HaCaT cells, suggesting that oxidative stress contributes to COX-2 induction. To examine the signaling pathways involved in the UVB-induced expression of COX-2 in HaCaT cells, we analysed the expression of COX-2 protein after treatment with various inhibitors of signaling molecules. Inhibition of EGFR by a specific inhibitor and by a neutralizing antibody suppressed the induction of COX-2 expression by UV. Although a neutralizing antibody to transforming growth factor-alpha (TGF-alpha) suppressed COX-2 expression induced by TGF-alpha, it did not suppress COX-2 expression by UV, indicating that a direct activation of EGFR is involved. Treatment of cells at low temperature (4 degrees C) inhibited UVB-induced JNK activation, but it did not inhibit COX-2 expression by UV. Inhibitors of MEK, p38 MAP kinase and PI3-kinase, suppressed the induction of COX-2 expression by UV. In contrast, an erbB-2 inhibitor augmented the UVB-induced increase of COX-2 protein. These data indicate that oxidative stress in association with activation of EGFR, ERK, p38 MAP kinase, and PI3-kinase plays crucial roles in the UVB induction of expression of COX-2.

Base Sequence↗
PubMed2003

Enhancement of cyclosporin A-induced autologous graft-versus-host disease after peripheral blood stem cell transplantation by utilizing selected CD34(+) cells.

Although autologous graft-versus-host disease (GVHD) can be induced by administration of cyclosporin A (CsA) after peripheral blood stem cell transplantation (PBSCT), the incidence appears to be remarkably lower compared to the incidence after bone marrow transplantation. The reduced incidence of autologous GVHD after PBSCT may be attributed to peripheral regulatory cells that are transferred with the stem cell inoculum. To determine whether transplantation of CD34-selected peripheral blood stem cells (PBSCs) leads to potentiation of autologous GVHD, five patients with malignant lymphoma were transplanted with CD34-selected PBSCs, followed by administration of CsA and interferon (IFN)-gamma. Inducibility of autologous GVHD and autocytotoxic activities of peripheral blood mononuclear cells (PBMCs) after transplantation were assessed. All patients demonstrated prompt hematologic recovery. Cytotoxic activity of PBMCs against autologous lymphocytes was detectable in four of four patients analyzed during a limited period from days 14 to 34 post-transplant. An erythematous rash compatible with GVHD, confirmed by skin biopsy, developed in three of five patients. One of the three patients developed not only skin, but also gut and liver GVHD. Transplantation of the CD34-selected stem cell graft that does not accompany transfusion of regulatory cells may potentiate the inducibility of autologous GVHD by the administration of CsA and IFN-gamma.

Antigens, CD34↗
PubMed2003

DNA microarray analysis of hematopoietic stem cell-like fractions from individuals with the M2 subtype of acute myeloid leukemia.

Acute myeloid leukemia (AML) may develop de novo or secondarily to myelodysplastic syndrome (MDS). Although the clinical outcome of MDS-related AML is worse than that of de novo AML, it is not easy to differentiate between these two clinical courses without a record of prior MDS. Large-scale profiling of gene expression by DNA microarray analysis is a promising approach with which to identify molecular markers specific to de novo or MDS-related AML. This approach has now been adopted with AC133-positive hematopoietic stem cell-like fractions purified from 10 individuals, each with either de novo or MDS-related AML of the M2 subtype. Sets of genes whose activity was associated with either disease course were identified. Furthermore, on the basis of the expression profiles of these genes, it was possible to predict correctly the clinical diagnosis for 17 (85%) of the 20 cases in a cross-validation trial. Similarly, different sets of genes were identified whose expression level was associated with clinical outcome after induction chemotherapy. These data suggest that, at least in terms of gene expression profiles, de novo AML and MDS-related AML are distinct clinical entities.

Antigens, CD↗
PubMed2003

Mast cell chymase expression in Helicobacter pylori-associated gastritis.

AIMS: To study the role of mast cell chymase in the inflammatory processes of human chronic gastritis. Experimental studies have shown that mast cell chymase stimulates inflammatory cell accumulation, and contributes to angiotensin II formation. METHODS AND RESULTS: Tissue sections from human stomachs with Helicobacter pylori-associated gastritis (surgery/autopsy n = 20; biopsy n = 16) and normal stomachs (n = 10) were studied using immunohistochemical single and double labelling techniques. Monoclonal antibodies used were directed against mast cell chymase, tryptase, neutrophils (CD66b, elastase, and myeloperoxidase), macrophages, T-lymphocytes, and interleukin (IL)-4. The expression of angiotensin-converting enzyme and angiotensin II type 1 receptor was investigated using immunohistochemical analysis and the reverse transcription-polymerase chain reaction. The number of chymase-positive mast cells was significantly higher (P < 0.0001) in H. pylori-associated gastritis than in normal stomachs. Increased expression of chymase in inflamed mucosa was closely related to an increase in the accumulation of neutrophils, macrophages, T-lymphocytes, and IL-4-positive cells. The expression of angiotensin-converting enzyme and angiotensin II type 1 receptor was not altered in gastritis specimens. CONCLUSIONS: These observations suggest that mast cell chymase may be an important mediator in the inflammatory processes of human H. pylori-associated gastritis.

Chronic Disease↗
PubMed2003

Hepatitis C virus genotype testing in paraffin wax embedded liver biopsies for specimen identification.

Despite advances in medical technology, careful specimen identification is still a fundamental principle of laboratory testing. If pathological samples are mixed up, especially in the case of extremely small biopsy samples, large amounts of time and energy may be wasted in correctly identifying the specimens. Recently, two liver biopsy specimens were mixed up in this department, and a new pathological technology was used to resolve the issue. Liver biopsy was performed on two patients with hepatitis C virus (HCV) infection. During sample transfer or tissue processing, the biopsy specimens were mixed up. Because the ABO blood group of the two patients was identical (type AB), the specimens were subsequently identified by analysing the HCV genotypes. RNA extracted from the paraffin wax embedded liver specimens was examined by a polymerase chain reaction based HCV genotype assay. This enabled the correct identification of the specimens, and each patient received the appropriate treatment on the basis of the accurate diagnosis.

Adult↗
PubMed2003

Curvature analysis of the mandibular condyle.

OBJECTIVE: To determine whether curvature analysis on high resolution CT images can be used as a tool for evaluation of mandibular condyle morphology. METHODS: Curvature analysis was performed on reconstructed oblique coronal CT images of 634 normal condyles from 317 patients (144 men and 173 women; age range 4-89 years) with inner or middle ear disease. The condyles were scanned with 1 mm collimation using helical CT. The CT images were analysed manually on a personal computer. RESULTS: The condyle CT images could be categorized into five curvature profile patterns: (1) bi-peak; (2) no peak; (3) tri-peak; (4) bi-peak with an intervening bottom above the base line (bi-peak with a col); and (5) bi-peak with an intervening negative phase. A separate evaluation using computer graphic condyle models indicated that these curvature patterns corresponded to flat (bi-peak), round (no peak), convex (bi-peak with a col), concave (bi-peak with a negative phase) and angled (tri-peak) contours of the condyle's superior surface. The curvature profiles were identical between bilateral condyles in 40% (126/317) of the patients. Gender-related differences in the incidence of the curvature profiles were also found, the bi-peak with a col profile being more frequently observed in women and the bi-peak with a negative phase profile being observed more frequently in men. CONCLUSION: Curvature analysis on CT images depicts condyle morphology effectively and may be an adjunctive tool for condyle morphometry.

Adolescent↗
PubMed2002

Long anchor using Flo1 protein enhances reactivity of cell surface-displayed glucoamylase to polymer substrates.

We investigated the influence of anchor length on the reactivity to polymer substrate of enzyme displayed on yeast cell surfaces. Using various lengths [42, 102, 146, 318, 428, and 1,326 amino acids (aa)] of the C-terminal region of the Saccharomyces cerevisiae Flo1 protein (Flo1p), which plays a major role in yeast flocculation, six display systems with various anchor lengths were constructed. In these systems, the target protein was displayed on the yeast cell surface under the control of the 5'-upstream region of the isocitrate lyase gene of Candida tropicalis ( UPR-ICL). Cell-surface display of Rhizopus oryzae glucoamylase by these systems was induced and confirmed in all systems by immunofluorescence microscopy and immunoblotting. Flow-cytometer measurement of the fluorescence intensity of immunofluorescence-labeled yeast cells displaying glucoamylase indicated that glucoamylase displayed with longer anchors, especially those of 428 and 1,326 aa in length, had higher reactivity to antibodies. The reactivity of starch to displayed glucoamylase, which was evaluated by plate assay, increased with anchor length, as did the cell growth-rate in starch-containing medium. These results indicate that cell-surface display systems using 428- and 1,326-aa length anchors of Flo1p are effective for the display of enzymes on the outer surface of yeast cells.

Cloning, Molecular↗
PubMed2002

An arming yeast with the ability to entrap fluorescent 17beta-estradiol on the cell surface.

We constructed a novel surface-engineered yeast displaying the ligand-binding domain of the rat estrogen receptor (ERLBD). ERLBD, display of which on the yeast cell surface was confirmed by immunofluorescence, possessed strong binding activity to fluorescent 17beta-estradiol - an analogue of the natural ligand of the estrogen receptor - that was comparable to the activity of the native receptor. Environmental homeostasis has recently been disturbed by endocrine disruptors, which cause confusion in the hormone secretion system. It is therefore very important to identify chemical compounds with hormone-like activity and remove them from the environment. The present results demonstrate that the new arming yeast displaying ERLBD on its cell surface will be capable of screening, entrapping, and removing estradiol-like compounds from the environment.

Animals↗
PubMed2002

Cell surface-engineered yeast with ability to bind, and self-aggregate in response to, copper ion.

In order to construct a cell surface-engineered yeast Saccharomyces cerevisiae that facilitates adsorption and recovery of heavy metal ions, we endowed it with the ability to self-aggregate in response to binding and accumulation of copper ion. A fusion gene for the expression of GTS1, which encodes a putative zinc-finger transcription factor related to occurrence of cell-aggregation, was constructed under the control of the copper ion-inducible CUP1 promoter from the yeast metallothionein gene. The multicopy plasmid carrying the fusion gene was introduced into a cell surface-engineered yeast displaying histidine hexa-peptide, which can chelate copper ion. This transformant strain aggregated in medium only in the presence of copper ion, with aggregation induced by as little as 1 mM copper ion. The copper ion-induced aggregation did not interfere with the copper ion-adsorbing function of the cell surface-engineered yeast, indicating that this transformant strain has the twin features of enhanced cell surface adsorption of copper ion and self-aggregation in response to environmental copper ion.

Adsorption↗
PubMed2002

Screening of a molecule endowing Saccharomyces cerevisiae with n-nonane-tolerance from a combinatorial random protein library.

A combinatorial random protein library was constructed from random DNA fragments generated by "DNA random priming", an improved method of "random-priming recombination" using random-sequence primers and template cDNA from the yeast Saccharomyces cerevisiae. In order to express this library on the yeast cell surface, a yeast multicopy cassette vector was constructed, in which the random-protein-encoding DNA fragments were fused to a gene encoding the C-terminal 320 amino acids of alpha-agglutinin. Fluorescent labeling of the immuno-reaction of RGS(His)(6) epitope confirmed the surface display of random proteins. The surface display of heterologous random proteins on yeast cells will have a wide application. As an example, an n-nonane-tolerant yeast strain that could grow very well in nonane-overlaid culture medium was screened out from transformants displaying this combinatorial library. n-Nonane tolerance was dependent on the transformed plasmid, and the related protein was confirmed to localize on the cell surface by papain treatment and immunofluorescent labeling. Analysis of this displayed protein was also carried out. This strain is the first one to have been endowed artificially with organic solvent tolerance. This is a good example of creating cells exhibiting new phenotypes using a combinatorial protein library.

Adaptation, Physiological↗
PubMed2002

High-level ethanol production from starch by a flocculent Saccharomyces cerevisiae strain displaying cell-surface glucoamylase.

A Strain of host yeast YF207, which is a tryptophan auxotroph and shows strong flocculation ability, was obtained from SaccharomYces diastaticus ATCC60712 and S. cerevisiae W303-1B by tetrad analysis. The plasmid pGA11, which is a multicopy plasmid for cell-surface expression of the Rhyzopus oryzae glucoamylase/alpha-agglutinin fusion protein, was then introduced into this flocculent yeast strain (YF207/pGA11). Yeast YF207/pGA11 grew rapidly under aerobic condition (dissolved oxygen 2.0 ppm), using soluble starch. The harvested cells were used for batch fermentation of soluble starch to ethanol under anaerobic condition and showed high ethanol production rates (0.71 g h(-1) l(-1)) without a time lag, because glucoamylase was immobilized on the yeast cell surface. During repeated utilization of cells for fermentation, YF207/pGA11 maintained high ethanol production rates over 300 h. Moreover, in fed-batch fermentation with YF207/pGA11 for approximately 120 h, the ethanol concentration reached up to 50 g l(-1). In conclusion, flocculent yeast cells displaying cell-surface glucoamylase are considered to be very effective for the direct fermentation of soluble starch to ethanol.

Aerobiosis↗