Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 41
Filter
1.
Aliment Pharmacol Ther ; 55(12): 1569-1580, 2022 06.
Article in English | MEDLINE | ID: mdl-35274323

ABSTRACT

BACKGROUND: The increasing incidence of older-onset ulcerative colitis (UC), which has a higher risk of surgery, is a global health issue. However, data regarding intravenous steroid treatment, one of the important treatment options to avoid surgery, for older-onset UC is lacking. AIMS: To evaluate the association between onset age and effectiveness of intravenous steroids in UC. METHODS: This retrospective multicentre (27 facilities) cohort study included moderate-to-severe hospitalised UC patients who underwent their first intravenous steroids between April 2014 and July 2019. The primary outcome was clinical remission at day 30, using two-item patient-reported outcome scoring. The key secondary outcomes were risks of surgery and adverse events (death, infection and venous thrombosis) within 90 days. A modified Poisson regression model was used for analysis. RESULTS: Overall, 467 UC patients (384 younger-onset and 83 older-onset) were enrolled. Clinical remission at day 30 was observed in 252 (65.6%) among younger-onset patients and 43 (51.8%) among older-onset patients (adjusted risk difference, -21.7% [95% CI, -36.1% to -7.2%]; adjusted risk ratio [ARR], 0.74 [95% CI, 0.59 to 0.93]). The risks of surgery and adverse events were higher in older-onset UC (20.5% vs. 3.1%; ARR, 8.92 [95% CI, 4.13 to 19.27], 25.3% vs. 9.1%; ARR, 2.19 [95% CI, 1.22 to 3.92], respectively). Four deaths occurred, all involving older-onset UC. The risks of infection and venous thrombosis were also higher in older-onset UC (18.1% vs. 8.6%, 7.2% vs. 0.5%, respectively). CONCLUSIONS: Older-onset was associated with a lower effectiveness of intravenous steroids with higher risks of surgery and adverse events in UC.


Subject(s)
Colitis, Ulcerative , Administration, Intravenous , Aged , Cohort Studies , Colitis, Ulcerative/surgery , Humans , Retrospective Studies , Steroids/therapeutic use
2.
Anal Chem ; 92(22): 14939-14946, 2020 11 17.
Article in English | MEDLINE | ID: mdl-33112611

ABSTRACT

The development of a versatile sensing strategy for the damage-free characterization of cultured cells is of great importance for both fundamental biological research and industrial applications. Here, we present a pattern-recognition-based cell-sensing approach using a multichannel surface plasmon resonance (SPR) chip. The chip, in which five cysteine derivatives with different structures are immobilized on Au films, is capable of generating five unique SPR sensorgrams for the cell-secreted molecules that are contained in cell culture media. An automatic statistical program was built to acquire kinetic parameters from the SPR sensorgrams and to select optimal parameters as "pattern information" for subsequent multivariate analysis. Our system rapidly (∼10 min) provides the complex information by merely depositing a small amount of cell culture media (∼25 µL) onto the chip, and the amount of information obtained is comparable to that furnished by a combination of conventional laborious biochemical assays. This noninvasive pattern-recognition-based cell-sensing approach could potentially be employed as a versatile tool for characterizing cells.


Subject(s)
Lab-On-A-Chip Devices , Surface Plasmon Resonance/instrumentation , Cell Line, Tumor , Cysteine/chemistry , Gold/chemistry , Humans , Kinetics , Oligonucleotide Array Sequence Analysis
3.
Anal Chem ; 90(12): 7578-7582, 2018 06 19.
Article in English | MEDLINE | ID: mdl-29846061

ABSTRACT

We propose a sequence-selective assay of N6-methyl-adenosine (m6A) in RNA without PCR or reverse transcription, by employing a hybridization assay with a DNA probe designed to form a bulge loop at the position of a target modified nucleotide. The m6A in the bulge in the RNA-DNA hybrid was assumed to be sufficiently mobile to be selectively recognized by an anti-m6A antibody with a high affinity. By employing a surface-plasmon-resonance measurement or using a microtiter-plate immunoassay method, a specific m6A in the Escherichia coli 23S rRNA sequence could be detected at the nanomolar level when synthesized and purified oligo-RNA fragments were used for measurement. We have successfully achieved the first selective detection of m6A2030 specifically in 23S rRNA from real samples of E. coli total RNA by using our immunochemical approach.


Subject(s)
Adenosine/analogs & derivatives , DNA, Bacterial/chemistry , Escherichia coli/chemistry , RNA, Bacterial/chemistry , RNA, Ribosomal, 23S/chemistry , Adenosine/analysis , Molecular Structure , Surface Plasmon Resonance
4.
Carbohydr Res ; 434: 121-131, 2016 Nov 03.
Article in English | MEDLINE | ID: mdl-27639338

ABSTRACT

A regio- and stereo-controlled, rhodium(II)-catalyzed amidoglycosylation of alcohols has been developed using O-acetylated glycals, trichloroethoxysulfonamide, and iodosobenzene. This one-pot amidoglycosylation was applied to a variety of primary and secondary alcohols to afford the ß-O-glycosides with acceptable yields up to 84%. The reaction would proceed via stereoselective intermolecular aziridination of the glycal from the α-face followed by SN2 reaction with alcohol at C-1 from the ß-face to give 1,2:2,3-di-trans-substituted isomer only.


Subject(s)
Alcohols/chemical synthesis , Amides/chemistry , Sulfonamides/chemistry , Alcohols/chemistry , Glycosylation , Iodobenzenes/chemistry , Molecular Structure , Rhodium/chemistry , Stereoisomerism
5.
Anal Chem ; 87(22): 11581-6, 2015 Nov 17.
Article in English | MEDLINE | ID: mdl-26482842

ABSTRACT

This paper reports a sequence-specific immunoassay chip for DNA methylation assessment by microfluidic-based surface plasmon resonance (SPR) detection. This was achieved by utilizing an affinity measurement involving the target, (methyl)cytosine, in a single-base bulge region and an anti-methylcytosine antibody in a microchannel, following hybridization with a biotinylated bulge-inducing DNA probe. The probe alters the target cytosine in a looped-out state because of the π-π stacking between flanking bases of the target. The probe design is simple and consists of the elimination of guanine paired with the target cytosine from a fragmented full-match sequence. We obtained the single methylation status in 6 amol (48 fg) of synthesized oligo DNA in 45 min, which is the fastest DNA methylation assessment yet reported, without employing a conventional bisulfite reaction, PCR, or sequencing. We also succeeded in discrimination of the methylation status of single cytosine in genomic λ DNA and HCT116 human colon cancer cells. The advantages of the proposed method are its small equipment, simple microfluidics design, ease of handling (two injections of DNA and antibody), lack of need for a methylation-sensitive enzyme, and neutral buffer conditions.


Subject(s)
Cytosine/metabolism , DNA Methylation , DNA/metabolism , Epigenomics/methods , Immunoassay , Microfluidic Analytical Techniques , Surface Plasmon Resonance/instrumentation , Bacteriophage lambda/genetics , Cytosine/chemistry , DNA/chemical synthesis , DNA/chemistry , DNA/genetics , DNA Probes/chemistry , HCT116 Cells , Humans , Immunoassay/instrumentation , Microfluidic Analytical Techniques/instrumentation , Polymerase Chain Reaction/instrumentation
6.
Anal Sci ; 31(7): 635-41, 2015.
Article in English | MEDLINE | ID: mdl-26165286

ABSTRACT

The effect of the sp(2)/sp(3) ratio in an unbalanced magnetron sputtered nanocarbon film electrode was studied for determining Cd(2+) and Pb(2+) by anodic stripping voltammetry (ASV). The signal-to-noise ratio in the ASV measurement improved as the sp(3) concentration in the carbon film increased because the noise current decreased with the increasing sp(3) concentration. The detection limits with a carbon film containing 50% sp(3) were 0.25 and 1.0 µg L(-1) for Cd(2+) and Pb(2+) with high repeatability (Cd: 4.6% and Pb: 6.4%, n = 3). For a real sample measurement, a pretreatment system combining a photooxidation reactor and a cation exchange column was used to eliminate the interference from EDTA and Cu(2+), which forms a stable complex or alloy with Cd(2+) and Pb(2+). More than 99% of the interference was eliminated, and accurate signal currents for Cd(2+) and Pb(2+) were successfully obtained with the pretreatment system.


Subject(s)
Carbon/chemistry , Electrochemistry/instrumentation , Magnetic Phenomena , Nanostructures/chemistry , Cadmium/analysis , Cadmium/chemistry , Calibration , Copper/chemistry , Edetic Acid/chemistry , Electrodes , Ion Exchange , Lead/analysis , Lead/chemistry , Limit of Detection , Oxidation-Reduction , Photochemical Processes
7.
Biosens Bioelectron ; 70: 366-71, 2015 Aug 15.
Article in English | MEDLINE | ID: mdl-25845328

ABSTRACT

We report the sequence-selective immunochemical discrimination of methylcytosine from genomic DNA that we achieved by utilizing selective antibody binding to a looped-out methylcytosine in a bulge region and without using bisulfite treatment, a methylation-sensitive restriction enzyme, or PCR. First, we investigated the affinity of an anti-methylcytosine antibody for methylcytosine in full match, bulge, mismatch and abasic sites using surface plasmon resonance measurement and a microtiter plate to explore the differences as regards antibody binding to the target methylcytosine. The highest affinity, which was comparable to that in a single strand of DNA, was observed in the bulge region. In particular, no affinity was observed in a full match site. This is because there is no interaction such as hydrogen bond or π-π stacking for the bulged methylcytosine, thus enabling only the target in the bulge to be looped out. Methylated and unmethylated genomic DNA were blended to form a model DNA with which to assess the methylation ratio at a specific site. Fragmented DNA was hybridized with a biotinylated probe DNA, which has a sequence capable of forming a single base bulge at the target. The probe design is simple because it consists solely of the elimination of guanine paired with the target cytosine from a full match sequence. As a result, we successfully obtained a linear relationship (r(2)=0.9962) between the immunoassay signal and the methylation ratio of a specific site within 4 h.


Subject(s)
Chromosome Mapping/methods , Cytosine/analysis , Cytosine/chemistry , DNA/chemistry , DNA/immunology , Immunoassay/methods , DNA/genetics , DNA Methylation , Genome/genetics , Genome/immunology , Humans , Nucleic Acid Conformation , Reproducibility of Results , Sensitivity and Specificity
8.
Anal Chem ; 85(21): 9996-9, 2013 Nov 05.
Article in English | MEDLINE | ID: mdl-24117377

ABSTRACT

The development of a biocatalytic electrode consisting of cytochrome P450 (CYP) proteins would be a key technology with which to establish simple drug metabolizing biosensors or screening devices for drug inhibitors. We have successfully detected the direct electron transfer (DET) from a human CYP layer or a CYP microsome adsorbed on a bare indium tin oxide (ITO) film electrode without any modification layers and applied it to drug metabolism evaluation. We compared the electrocatalytic properties of the two ITO films with different surface nanostructures (polycrystalline or amorphous). CYP on polycrystalline ITO film enhanced the electron transfer rate of oxygen reduction about fifteen times more than with amorphous film. The polycrystalline ITO film was a suitable electrode for the adsorption of CYP proteins while maintaining efficient DET and enzymatic activity, probably because of its larger surface area and negatively charged surface. The oxygen reduction current at the polycrystalline ITO film electrodes had increased 3- to 4-fold, specifically coupled with the oxidation of drugs (testosterone and quinidine) by the monooxygenase activity of CYP. In contrast, the oxygen reduction current completely disappeared in the presence of the CYP inhibitor (ketoconazole). Similar results could be obtained from the CYP microsome with sufficiently clear responses. These results indicate that the CYP modified polycrystalline ITO electrode offers the potential for electrochemically evaluating CYP activity for drug metabolism with a simple configuration.


Subject(s)
Biosensing Techniques , Cytochrome P-450 Enzyme System/chemistry , Electrochemistry/methods , Enzymes, Immobilized/chemistry , Tin Compounds/chemistry , Crystallization
9.
Langmuir ; 29(42): 13111-20, 2013 Oct 22.
Article in English | MEDLINE | ID: mdl-24063697

ABSTRACT

In order to develop a biosensing system with waveguide-mode sensor, fabrication of a biosensing interface on the silica surface of the sensing chip was carried out using triethoxysilane derivatives with anti-leptin antibody. Triethoxysilane derivatives bearing succinimide ester and oligoethylene glycol moieties were synthesized to immobilize the antibody and to suppress nonspecific adsorption of proteins, respectively. The chip modified with triethoxysilane derivatives bearing oligoethylene glycol moiety suppressed nonspecific adsorption of proteins derived from human serum effectively by rinse with PBS containing surfactant (0.05% Tween 20). On the other hand, it was confirmed that antibody was immobilized on the chip by immersion into antibody solution to show response of antigen-antibody reaction, where the chip was modified with triethoxysilane derivatives bearing succinimide ester moiety. When the interface was fabricated with antibody and a mixture of triethoxysilane derivatives bearing succinimide ester and oligoethylene glycol moieties, the response of antigen-antibody reaction depended on composition of the mixture and enhanced with the increase of ratio for triethoxysilane derivatives bearing succinimide ester moiety reflecting the antibody concentration immobilized on the chip. While introduction of excess triethoxysilane derivatives bearing succinimide ester moiety induced nonspecific adsorption of proteins derived from human serum, the immobilized antibody on the chip kept its activity after 1-month storage in a refrigerator. Taking into consideration those factors, the biosensing interface was fabricated using triethoxysilane derivatives with anti-leptin antibody to examine performance of the waveguide-mode sensor. It was found that the detection limits for human leptin were 50 ng/mL in PBS and 100 ng/mL in human serum. The results demonstrate that the waveguide-mode sensor powered by the biosensing interface fabricated with those triethoxysilane derivatives and antibody has potential to detect several tens of nanograms per milliliter of biomarkers in human serum with an unlabeled detection method.


Subject(s)
Antibodies/chemistry , Biosensing Techniques , Leptin/analysis , Silanes/chemical synthesis , Adsorption , Animals , Antigen-Antibody Reactions , Biosensing Techniques/instrumentation , Cattle , Ethylene Glycol/chemistry , Humans , Recombinant Proteins/analysis , Silanes/chemistry , Silicon Dioxide/chemistry , Succinimides/chemistry , Surface Properties
10.
Langmuir ; 28(3): 1846-51, 2012 Jan 24.
Article in English | MEDLINE | ID: mdl-22176741

ABSTRACT

A hybrid functional biomolecular interface designed at a molecular size level is very effective at capturing an analyte with high sensitivity even if the interaction is very weak, as when detecting proteins with carbohydrate. We designed and processed a protein (lectin) recognition molecular interface taking the following points into consideration: (1) the height (molecular length) difference between the capturing and spacer molecules; (2) the ratio of capturing molecules in the recognition interface. When the height difference between the maltoside part (Concanavalin A (Con A) recognition group) and the OH group terminated spacer molecules exceeded (>(CH(2))(6)), the association rate constant (k(a)) became larger (k(a)(1/Ms): ∼2.6 times) and the dissociation constant (K(D)) became much smaller (K(D)(M): 1.0 × 10(-6): ∼0.17 times) compared with the similar heights (lengths) of both molecular interfaces. With regard to maltoside density, a 100% maltoside monolayer was unsuitable for detecting Con A. We constructed a nanostructured recognition site with a maltoside part of 10%, which was the most suitable ratio for Con A detection. The binding interaction between Con A and the maltoside group was changed from monovalent binding to bivalent binding when the maltoside part was diluted in the recognition interface. From electrochemical measurements, even though there was a small amount of maltoside component on the suitable recognition monolayer, quality similar to that of 100% maltoside was observed.


Subject(s)
Concanavalin A/chemistry , Electrochemistry/methods , Glucosides/chemistry , Lectins/chemistry , Nanostructures/chemistry , Sulfhydryl Compounds/chemistry , Adsorption , Concanavalin A/metabolism , Kinetics , Lectins/metabolism , Surface Properties
11.
Biosci Biotechnol Biochem ; 75(6): 1135-9, 2011.
Article in English | MEDLINE | ID: mdl-21670529

ABSTRACT

To measure the interactions of diacylglycerol acyltransferase (DGAT) by surface plasmon resonance (SPR), we immobilized Saccharomyces cerevisiae DGAT2 encoded by DGA1 on a BIACORE sensor chip surface. We used N-terminally truncated Dga1p with a FLAG tag at the C-terminus, which was purified to apparent homogeneity, maintaining significant DGAT activity (Kamisaka et al., Appl. Microbiol. Biotechnol., 88, 105-115 (2010)). Truncated Dga1p with a FLAG tag was immobilized with an anti-FLAG antibody that had been coupled with an L1 chip surface consisting of a carboxymethyl dextran matrix with additional hydrophobic alkane groups. The Dga1p-immobilized chip surface was analyzed for interactions of Dga1p with oleoyl-CoA, its substrate, and anti-Dga1p IgG, its interacting protein, by SPR. The binding of these analytes with the Dga1p-immobilized chip surface was specific, because butyryl-CoA, which cannot be used as a substrate for DGAT, and anti-glyceraldehyde-3-phosphate dehydrogenase IgG, did not induce any signals on SPR. Furthermore, injection of organic compounds such as xanthohumol, a DGAT inhibitor, into the Dga1p-immobilized chip surface induced significant SPR signals, probably due to interaction with DGAT. Another DGAT inhibitor, piperine, did not induce SPR signals on application, but induced them due to piperine on application together with oleoyl-CoA, in which piperine can be incorporated into the micelles of oleoyl-CoA. The results indicate that the Dga1p-immobilized L1 chip surface recognized DGAT inhibitors. Taking all this together, SPR measurement using the Dga1p-immobilized L1 chip surface provided a useful system to elucidate the structure-function relationships of DGAT and screen DGAT inhibitors.


Subject(s)
Acyl Coenzyme A/metabolism , Diacylglycerol O-Acyltransferase/metabolism , Enzymes, Immobilized/metabolism , High-Throughput Screening Assays , Lab-On-A-Chip Devices , Saccharomyces cerevisiae/enzymology , Surface Plasmon Resonance/methods , Alkaloids/pharmacology , Alkanes/chemistry , Antibodies/metabolism , Benzodioxoles/pharmacology , Dextrans/chemistry , Diacylglycerol O-Acyltransferase/antagonists & inhibitors , Diacylglycerol O-Acyltransferase/chemistry , Enzyme Inhibitors/pharmacology , Enzymes, Immobilized/antagonists & inhibitors , Enzymes, Immobilized/chemistry , Flavonoids/pharmacology , Oligopeptides , Peptides/metabolism , Piperidines/pharmacology , Polyunsaturated Alkamides/pharmacology , Propiophenones/pharmacology , Protein Binding , Saccharomyces cerevisiae/chemistry , Structure-Activity Relationship , Substrate Specificity
12.
Sci Signal ; 4(157): ra3, 2011 Jan 25.
Article in English | MEDLINE | ID: mdl-21266714

ABSTRACT

The development of obesity involves multiple mechanisms. Here, we identify adipocyte signaling through the guanosine triphosphatase Rho and its effector Rho-kinase as one such mechanism. Mice fed a high-fat diet (HFD) showed increased Rho-kinase activity in adipose tissue compared to mice fed a low-fat diet. Treatment with the Rho-kinase inhibitor fasudil attenuated weight gain and insulin resistance in mice on a HFD. Transgenic mice overexpressing an adipocyte-specific, dominant-negative form of RhoA (DN-RhoA TG mice) showed decreased Rho-kinase activity in adipocytes, decreased HFD-induced weight gain, and improved glucose metabolism compared to wild-type littermates. Furthermore, compared to HFD-fed wild-type littermates, DN-RhoA TG mice on a HFD showed decreased adipocyte hypertrophy, reduced macrophage recruitment to adipose tissue, and lower expression of mRNAs encoding various adipocytokines. Lipid accumulation in cultured adipocytes was associated with increased Rho-kinase activity and increased abundance of adipocytokine transcripts, which was reversed by a Rho-kinase inhibitor. Direct application of mechanical stretch to mature adipocytes increased Rho-kinase activity and stress fiber formation. Stress fiber formation, which was also observed in adipocytes from HFD-fed mice, was prevented by Rho-kinase inhibition and in DN-RhoA TG mice. Our findings indicate that lipid accumulation in adipocytes activates Rho to Rho-kinase (Rho-Rho-kinase) signaling at least in part through mechanical stretch and implicate Rho-Rho-kinase signaling in inflammatory changes in adipose tissue in obesity. Thus, inhibition of Rho-Rho-kinase signaling may provide a therapeutic strategy for disrupting a vicious cycle of adipocyte stretch, Rho-Rho-kinase signaling, and inflammation of adipose tissue that contributes to and aggravates obesity.


Subject(s)
Adipocytes/metabolism , Diet, Fat-Restricted , Obesity/metabolism , Phenotype , Signal Transduction/physiology , rho GTP-Binding Proteins/metabolism , rho-Associated Kinases/metabolism , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/analogs & derivatives , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/pharmacology , Animals , Insulin Resistance/physiology , Mechanical Phenomena , Mice , Mice, Transgenic , Obesity/physiopathology , Weight Gain/physiology , rho-Associated Kinases/antagonists & inhibitors
13.
Bioorg Med Chem Lett ; 21(4): 1265-9, 2011 Feb 15.
Article in English | MEDLINE | ID: mdl-21237642

ABSTRACT

Mercaptododecyl glycosides containing a terminal ß-galactosyl group were prepared from D-galactose or from D-lactose via hexa-O-acetyl-lactal (10) as a key intermediate. Interactions of these glycolipids (5 kinds) and galectins (ß-galactoside binding lectins, 6 species) were evaluated by surface plasmon resonance (SPR) method. High binding responses were observed for the lactoside, 2-deoxy-lactoside, and lactosaminide with some galectins (Gal-3, -4, -8), whereas the galactoside and 2,3-dideoxy-lactoside showed low binding activities.


Subject(s)
Galactose/chemistry , Galectins/chemistry , Glycosides/chemistry , Sulfhydryl Compounds/chemistry , Glycosides/chemical synthesis , Kinetics , Protein Binding , Surface Plasmon Resonance
14.
Langmuir ; 27(1): 170-8, 2011 Jan 04.
Article in English | MEDLINE | ID: mdl-21117684

ABSTRACT

Surface modification of glassy carbon (GC) and highly oriented pyrolytic graphite (HOPG) was carried out with diazonium, amine, azide, and olefin derivatives bearing ferrocene as an electroactive moiety. Features of the modified surfaces were evaluated by surface concentrations of immobilized molecule, blocking effect of the modified surface against redox reaction, and surface observation using cyclic voltammetry and electrochemical scanning tunneling microscope (EC-STM). The measurement of surface concentrations of immobilized molecule revealed the following three aspects: (i) Diazonium and olefin derivatives could modify substrates with the dense-monolayer concentration. (ii) The surface concentration of immobilized amine derivative did not reach to the dense-monolayer concentration reflecting their low reactivity. (iii) The surface modification with the dense-monolayer concentration was also possible with azide derivative, but the modified surface contained some oligomers produced by the photoreaction of azides. Besides, the blocking effect against redox reaction was observed for GC modified with diazonium derivative and for HOPG modified with diazonium and azide derivatives, suggesting fabrication of a densely modified surface. Finally, the surface observation for HOPG modified with diazonium derivative by EC-STM showed a typical monolayer structure, in which the ferrocene moieties were packed densely at random. On the basis of those results, it was demonstrated that surface modification of carbon substrates with diazonium could afford a dense monolayer similar to the self-assembled monolayer (SAM) formation.


Subject(s)
Alkenes/chemistry , Amines/chemistry , Azides/chemistry , Carbon/chemistry , Diazonium Compounds/chemistry , Glass/chemistry , Graphite/chemistry , Electrochemistry , Ferrous Compounds/chemistry , Metallocenes , Microscopy, Scanning Tunneling , Oxidation-Reduction , Surface Properties
15.
J Biol Chem ; 285(17): 13045-56, 2010 Apr 23.
Article in English | MEDLINE | ID: mdl-20139070

ABSTRACT

Sirt1, a NAD-dependent protein deacetylase, is reported to regulate intracellular metabolism and attenuate reactive oxidative species (ROS)-induced apoptosis leading to longevity and acute stress resistance. We created transgenic (TG) mice with kidney-specific overexpression of Sirt1 using the promoter sodium-phosphate cotransporter IIa (Npt2) driven specifically in proximal tubules and investigated the kidney-specific role of Sirt1 in the protection against acute kidney injury (AKI). We also elucidated the role of number or function of peroxisome and mitochondria in mediating the mechanisms for renal protective effects of Sirt1 in AKI. Cisplatin-induced AKI decreased the number and function of peroxisomes as well as mitochondria and led to increased local levels of ROS production and renal tubular apoptotic cells. TG mice treated with cisplatin mitigated AKI, local ROS, and renal tubular apoptotic tubular cells. Consistent with these results, TG mice treated with cisplatin also exhibited recovery of peroxisome number and function, as well as rescued mitochondrial function; however, mitochondrial number was not recovered. Immunoelectron microscopic findings consistently demonstrated that the decrease in peroxisome number by cisplatin in wild type mice was restored in transgenic mice. In HK-2 cells, a cultured proximal tubule cell line, overexpression of Sirt1 rescued the cisplatin-induced cell apoptosis through the restoration of peroxisome number, although the mitochondria number was not restored. These results indicate that Sirt1 overexpression in proximal tubules rescues cisplatin-induced AKI by maintaining peroxisomes number and function, concomitant up-regulation of catalase, and elimination of renal ROS levels. Renal Sirt1 can be a potential therapeutic target for the treatment of AKI.


Subject(s)
Kidney Diseases/metabolism , Kidney Tubules, Proximal/injuries , Kidney Tubules, Proximal/metabolism , Peroxisomes/metabolism , Sirtuin 1/biosynthesis , Acute Disease , Animals , Antineoplastic Agents/adverse effects , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Apoptosis/genetics , Catalase/biosynthesis , Catalase/genetics , Cell Line , Cisplatin/adverse effects , Cisplatin/pharmacology , Kidney Diseases/chemically induced , Kidney Diseases/genetics , Kidney Diseases/therapy , Kidney Tubules, Proximal/pathology , Longevity/drug effects , Longevity/genetics , Male , Mice , Mice, Transgenic , Mitochondria/genetics , Mitochondria/metabolism , Organ Specificity , Peroxisomes/genetics , Reactive Oxygen Species/metabolism , Sirtuin 1/genetics , Sodium-Phosphate Cotransporter Proteins, Type IIa/biosynthesis , Sodium-Phosphate Cotransporter Proteins, Type IIa/genetics , Up-Regulation/drug effects , Up-Regulation/genetics
16.
Anal Sci ; 26(1): 33-7, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20065584

ABSTRACT

Tri(ethylene glycol) terminated short alkylchain thiols (TEGCnSHs) offer good potential for constructing ultra-thin protein-resistant monolayers because they have an alkylchain for forming a densely packed monolayer and a flexible-hydrophilic oligo ethylene glycol arm for avoiding non-specific adsorption. Hybrid monolayers consisting of TEGCnSH and a maltoside ligand (MalC12SH, for capturing lectin) were effective in detecting concanavalin A (Con A). This hybrid monolayer was more suitable for Con A detection than that modified with 100% ligands in terms of the detection limit and time. The anti-fouling properties, packing densities, interaction and homogeneity of TEGCnSH monolayers were confirmed in detail by surface plasmon resonance (SPR) measurements and electrochemical methods. SPR measurements revealed their excellent repellency to proteins and peptides of various sizes (M(W) 400-104000). The electrochemical results indicated that the lower defects in the TEGCnSH monolayers suppressed the permeation of small peptides. The stability, homogeneity and packing density of the TEGCnSH monolayers were gradually improved as their alkylchain length increased.


Subject(s)
Ethylene Glycols/chemistry , Sulfhydryl Compounds/chemistry , Adsorption , Alkanes/chemistry , Concanavalin A/chemistry , Electrochemistry , Membranes, Artificial , Molecular Weight , Peptides/chemistry , Proteins/chemistry
17.
Anal Chem ; 82(4): 1175-8, 2010 Feb 15.
Article in English | MEDLINE | ID: mdl-20092278

ABSTRACT

Galectins, or beta-galactoside binding lectins, are detected deep in tumor tissue and are recognized as diagnostic and prognostic markers of cancer and other serious diseases. There is a need to develop a faster, easier, and simpler method for detecting galectins. We have succeeded in forming a mixed self-assembled monolayer (SAM) interface consisting of beta-galactoside terminated alkanethiol (lactoside protuberant dodecanethiol) and tri(ethylene glycol) (TEG) terminated short alkanethiol, which proved to be a superior protein resistant material, to enable us to develop a label-free, one-step, and highly sensitive system for detecting the expected biomarker, galectin. We successfully detected nanomolar level (~ 1 nM) galectin-4 and -8 on a 4% lactoside protrusive surface, even though the affinity between the galectins and lactoside was very weak (KD = 1 x 10(-3)~1 x 10(-6)). The combination of the suppression of background noise by filling with TEG terminated short alkanethiol and control of the ligand ratio in the interface contributed to the highly sensitive detection of galectin. We also detected galectin-4 at subten nanomolar levels even in a solution containing much higher concentrations of serum proteins (1800 times larger than the galectin concentration) without using molecule labeling or an immunological method.


Subject(s)
Galectins/analysis , Glycosides/chemistry , Galectins/chemistry , Gold/chemistry , Polyethylene Glycols/chemistry , Substrate Specificity , Sulfhydryl Compounds/chemistry , Surface Plasmon Resonance , Surface Properties
18.
Clin J Gastroenterol ; 3(6): 285-8, 2010 Dec.
Article in English | MEDLINE | ID: mdl-26190485

ABSTRACT

We describe a case with rectal bleeding from a rectal ulcer after endoscopic mucosal resection (EMR), successfully treated with an ecabet sodium (ES) enema. A 44-year-old woman with a laterally spreading rectal tumor of a granular type, 60 mm in diameter, underwent piecemeal EMR. After the EMR, she suffered from rectal bleeding on several occasions over a period of 1 month. Although she was repeatedly treated with thermocoagulation by a heater probe to stop the bleeding, a rectal ulcer with visible vessels still remained at the resected site. Because the rectal ulcer was considered to be intractable, an ES enema was used twice a day (1.5 g) for 2 weeks, which improved rectal bleeding. Colonoscopic findings revealed that the ulcer improved with mucosal healing after the ES enema treatment. This represents the first report of an ES enema treatment in a patient with a rectal ulcer after EMR. Further studies are needed to determine the effectiveness and safety of using an ES enema in patients with EMR-related refractory colorectal ulcers.

19.
Ther Apher Dial ; 13(3): 193-8, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19527465

ABSTRACT

Patients undergoing hemodialysis are immunocompromised and can suffer from pneumonia with various pathogens in nosocomial conditions. We investigated the fundamental information on the characteristics of hemodialysis inpatients and nosocomial pneumonia. We surveyed 1803 hemodialysis patients admitted to our university hospital between 2001 and 2007. The mean patient age was 64.8 years and the average period of hospitalization was 28.1 days, which was considerably longer than the average stay in our hospital (14.2 days). Patients were admitted to many different departments and for various reasons. We isolated 391 microorganisms from the sputum of 120 pneumonia patients undergoing hemodialysis, including Candida albicans, methicillin-resistant Staphylococcus aureus, and Staphylococcus epidermidis, which were the leading three isolates. From these 120 patients, a total of 199 pathogens were identified as being responsible for the pneumonia. Multi-drug resistant Stenotrophomonas maltophilia was found to be susceptible to a new fluoroquinolone, but is resistant to older generation quinolones. Out of the 120 patients with pneumonia, 12 out of 18 patients infected with S. maltophilia died, indicating the highest fatality rate for this pathogen. In this survey, we found that hemodialysis patients were hospitalized for long periods, and for various reasons in many departments. They suffered from nosocomial pneumonia caused by multi-drug resistant pathogens, including S. maltophilia. For pneumonia due to S. maltophilia, new generation fluoroquinolones can be the treatment of choice, although S. maltophilia-related pneumonia should be treated very carefully because of its high fatality rate.


Subject(s)
Gram-Negative Bacterial Infections/mortality , Pneumonia, Bacterial/mortality , Renal Dialysis , Stenotrophomonas maltophilia/isolation & purification , Aged , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Cross Infection/drug therapy , Cross Infection/microbiology , Cross Infection/mortality , Drug Resistance, Multiple, Bacterial , Female , Gram-Negative Bacterial Infections/drug therapy , Gram-Negative Bacterial Infections/microbiology , Hospitals, University/statistics & numerical data , Humans , Japan/epidemiology , Kidney Failure, Chronic/complications , Kidney Failure, Chronic/therapy , Length of Stay , Male , Middle Aged , Opportunistic Infections/drug therapy , Opportunistic Infections/microbiology , Opportunistic Infections/mortality , Pneumonia, Bacterial/drug therapy , Pneumonia, Bacterial/microbiology , Renal Dialysis/mortality , Stenotrophomonas maltophilia/drug effects
20.
Clin J Gastroenterol ; 2(3): 190-193, 2009 Jun.
Article in English | MEDLINE | ID: mdl-26192294

ABSTRACT

Cheilitis granulomatosa (CG) is a rare disease, which presents usually as a persistent swelling of the soft tissues in the orofacial region and is characterized histologically by a granulomatous inflammation. We report the case of a 19-year-old man who suffered from anal fistula. The patient had a 6-year history of asymptomatic and persistent swelling of the lower lip. Examinations for gastrointestinal lesions containing double-balloon total enteroscopy revealed erosions located longitudinally throughout the small intestine and the patient was diagnosed Crohn's disease (CD). Biopsy of the lower lip showed non-caseating granuloma and confirmed the diagnosis of CG. Despite an elemental diet and mesalazine therapy, the lip swelling persisted. The CG can be the first presenting symptom of CD. CG as a complication of CD is discussed.

SELECTION OF CITATIONS
SEARCH DETAIL
...