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Biomedical subjects

Y Shindo

Publications and source records attributed to Y Shindo.

At least 19 recordsLinked to original sources
PubMed2003

Covered expandable metallic stent placement for hemostasis of colonic bleeding caused by invasion of gallbladder carcinoma.

A 72-year-old Japanese man was admitted to our hospital complaining of right upper-quadrant abdominal pain, blood in his stool, and symptoms of anemia. On physical examination a hard mass, about 6 cm in diameter, was palpable in the right upper quadrant of the abdomen. Computed tomography revealed a gallbladder carcinoma which had invaded the transverse colon, with liver metastasis. We diagnosed gallbladder carcinoma, stage IVB. Colonoscopy was performed for persistent blood in the stools. This revealed an elevated lesion which appeared to be an invasion of gallbladder carcinoma, with diffuse bleeding from the right-side of the transverse colon. It proved difficult to stop this bleeding by ordinary therapeutic endoscopy. In order to achieve hemostasis we therefore inserted a covered Ultraflex metallic stent to compress the tumor. After stent placement, blood was no longer seen in the patient's stools, he became able to eat soft food and was discharged. This treatment was uninvasive and effective. Covered stent placement appears to be a new and useful method in the management of bleeding from malignant gastrointestinal tumors.

Aged↗
PubMed2003

Start-up of full-scale anaerobic digesters treating municipal solid waste.

Raising organic loading rate, and the behavior of dissolved CODcr (D-CODcr), VFA and specific methanogen activity, were investigated through a laboratory experiment for the start-up of a sludge recycling center. Moreover, application for MPN-PCR methods using a gene as a direct technique to measure the quantity of methanogen was attempted. It was recognized that specific methanogen activity depends on the quantity of methanogen, and that gas production does not reflect the condition of methane fermentation. The methane fermentation condition was checked through the specific methanogen activity and analysis of D-CODcr. The target organic loading rate was reached in the short period of about 30 days, and rapid start-up was successfully attained for a full-scale anaerobic digester.

Bacteria, Anaerobic↗
PubMed2001

Concise synthesis of ciguatoxin ABC-ring fragments and surface plasmon resonance study of the interaction of their BSA conjugates with monoclonal antibodies.

Monoclonal antibodies (mAbs), 4H2 and 6H7, were prepared previously using a protein conjugate of a 1:1 epimeric mixture of the synthetic ABC-ring fragments of ciguatoxin (CTX), 3 and 4. Here, the interactions of these mAbs with the fragments of CTX and CTX3C, 3 and 5, were investigated by surface plasmon resonance (SPR) spectroscopy in an attempt to clarify an antigenic determinant. Compared with the previous synthesis, the fragment 3 possessing the 2S configuration was synthesized from tri-O-acetyl-D-glucal much more effectively. The mAb 4H2 was already known to show a dose-dependent binding to the bovine serum albumin (BSA) conjugate of 3, but not to that of 5. The present SPR study of 4H2 demonstrates that the A-ring side chain of 3 plays a decisive role as an epitope. Therefore, SPR can effectively replace the ELISA method for the analysis of mAbs.

Antibodies, Monoclonal↗
PubMed2001

A novel [2 + 2] photodimerization of N-[(E)-3,4-methylenedioxycinnamoyl]dopamine in the solid state.

[reaction: see text] To give photoreactivity to catecholamines, N-cinnamoyl-substituted dopamines (E)-5a-5c and O,O'-dimethyldopamines (E)-3a-3c were prepared under solvent-free conditions. A particularly interesting observed photoreactivity was that of N-[(E)-3,4-methylenedioxycinnamoyl]dopamine ((E)-5c), which underwent a novel type of [2 + 2] photodimerization in the solid state, giving exclusively a tricyclic product 8. This reaction is the first example of solid-state photoaddition of an alkene to the benzene ring.

Cinnamates↗
PubMed2000

Photoinduced graft polymerization of 2-methacryloyloxyethyl phosphorylcholine on polyethylene membrane surface for obtaining blood cell adhesion resistance.

Phospholipid polymer, poly[2-methacryloyloxyethyl phosphorylcholine (MPC)], was grafted with polyethylene (PE) membrane using photoinduced polymerization technique to make the membrane resistant to cell adhesion. The water contact angle on the PE membrane grafted with poly(MPC) decreased with an increase in the photopolymerization time. This decrease corresponded to the increase in the amount of poly(MPC) grafted on the PE surface. The same graft polymerization procedure was applied using other hydrophilic monomers, such as acrylamide (AAm), N-vinylpyrrolidone (VPy) and methacryloyl poly(ethylene glycol) (MPEG). These monomers were also polymerized to form grafted chains on the PE membrane, and the grafting was confirmed with X-ray photoelectron spectroscopy. Analysis of amount and distribution of plasma proteins at the plasma-contacting surface of the original and the modified PE membranes were analyzed using immunogold assay. The grafting of poly(MPC) and poly(VPy) on PE membrane reduced the plasma protein adsorption significantly compared with that on the original PE membrane. However, the PE membranes grafted with poly(AAm) or poly(MPEG) did not show any effects on protein adsorption. Platelet adhesion on the original and modified PE membranes from platelet-rich plasma was also examined. A large number of platelets adhered and activated on the original PE membrane. Grafting with poly(AAm) did not suppress platelet adhesion, but grafting with poly(MPC) or poly(VPy) on the PE membrane was effective in preventing platelet adhesion. It is concluded that the introduction of the phosphorylcholine group on the surface could decrease the cell adhesion to substrate polymer.

Journal Article↗
PubMed1999

Stimulation of hyaluronan synthesis by tumor necrosis factor-alpha is mediated by the p50/p65 NF-kappa B complex in MRC-5 myofibroblasts.

The lesions of fibrocontractive diseases result from an excessive myofibroproliferative response to numerous forms of inflammatory stimuli, which elicit the net deposition of extracellular matrix (ECM) in the interstitium of the affected tissue. Hyaluronan (HA), reported to be a key player supporting cellular migration and adherence, is a major component of ECM that undergoes dynamic regulation during inflammation. The molecular regulation of HA biosynthesis by inflammatory cytokines on myofibroblasts is not yet completely understood. Here we report the biochemical characteristics of the lung myofibroblast cell line MRC-5, and we demonstrate that the production of HA by this cell line is inducible by the proinflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha), at the message level of HA synthase (HAS). In TNF-alpha-stimulated MRC-5 cells, DNA-binding and competition experiments indicated that the predominant NF-kappa B binding activity detected with nuclear extract-stimulated cells is mediated by the p50/p65 complex. Using antisense oligonucleotides, we confirmed that the TNF-alpha-stimulation of HA synthesis by MRC-5 cells is dependent on the activation of the p50/p65 NF-kappa B complex. These findings indicate that TNF-alpha production within inflamed tissues may enhance the HA synthesis via the transcriptional induction of HAS on myofibroblasts, thereby providing a provisional matrix for supporting cellular migration and adhesion, and that the p50/p65 NF-kappa B complex that plays an important role in the regulation of HA production by TNF-alpha might be an appropriate target for therapeutic compounds to treat tissue fibrosis accompanied by inflammation.

Actins↗
PubMed1998

Ultraviolet B-induced cell death in four cutaneous cell lines exhibiting different enzymatic antioxidant defences: involvement of apoptosis.

Reactive oxygen species (ROS) play a role in the modulation of apoptosis. Antioxidant defence mechanisms against cell death involving apoptosis due to UVB irradiation were studied on three established cell lines (SCC derived from human skin squamous cell carcinoma, F-SV and F-ST derived from human skin fibroblasts) which were susceptible to cell death by UVB irradiation (12.5-250 mJ/cm2), and one cell line (N-F) derived from primary cultured human skin fibroblasts which was resistant to cell death. We compared antioxidant defences between the three established cell lines and N-F, measuring four antioxidant enzymes (superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px) and glutathione reductase (GR) and a non-enzymatic antioxidant glutathione. The greatest difference was that Cu, Zn-SOD activity in N-F was 3-4-times the three other cell lines. Though SCC had much larger amounts of glutathione and higher antioxidant enzyme activities except for Cu, Zn-SOD than N-F, SCC was very susceptible to cell death. After UVB irradiation (at 16 h after 12.5 mJ/cm2), in all cell lines, SOD activity increased 1.1-1.3-times that of non-irradiated cells, while other enzyme activities remained constant. This presumably represents a protective response against ROS generated during UVB irradiation. N-F which was resistant to UVB-induced cell death had higher Cu, Zn-SOD activity before UVB irradiation, and a larger increase of SOD (mainly Mn-SOD) after UVB exposure than the other cell lines which were susceptible to cell death. Therefore, we conclude that the most important enzymatic antioxidant to protect cells from UVB damage is SOD.

Antimetabolites↗
PubMed1998

Antisense sequences of the nbl gene induce apoptosis in the human promyelocytic leukemia cell line HL-60.

Apoptosis is induced by the transcriptional inhibitor actinomycin D (Act D) in various cell types, particularly many leukemic cell lines such as HL-60. A common feature of these cell lines is their high constitutive expression level of the nbl gene, which was originally isolated by virtue of its abundance in a Namalwa Burkitt lymphoma cDNA library. In contrast, cell lines which constitutively express nbl at low levels appear not to undergo typical apoptotic death in response to Act D. Apoptotic induction by Act D in cells which normally express nbl at high levels was found in this study to be closely associated with a decline in nbl mRNA levels, raising the possibility that apoptosis could be induced by lowering nbl expression levels in such cells. Transient expression of nbl antisense sequences in HL-60 cells decreased cell viability, and induced typical apoptotic morphology such as cell shrinkage, chromatin condensation and nuclear fragmentation. Incubation with nbl antisense oligomers also induced similar features in HL-60 cells and in another high nb-expressing cell line, Jurkat, but had little effect in HepG2 cells which constitutively express nbl at low levels. These findings suggest that lowering constitutively high levels of nbl expression can induce apoptosis.

Antineoplastic Agents, Hormonal↗
PubMed1998

Topical application of alpha-tocopherol modulates the antioxidant network and diminishes ultraviolet-induced oxidative damage in murine skin.

The aim of this study was to investigate the effects of topical alpha-tocopherol application on epidermal and dermal antioxidants and its ability to prevent ultraviolet (UV)-induced oxidative damage. Hairless mice received topical applications of alpha-tocopherol 24 h before a single, acute UV irradiation (10 x minimal erythemal dose). The four major antioxidant enzymes (catalase, superoxide dismutase, glutathione reductase and glutathione peroxidase), hydrophilic and lipophilic antioxidants, and lipid hydroperoxides, markers of oxidative damage, were assayed in both epidermis and dermis of hairless mice. Topical alpha-tocopherol treatment increased dermal superoxide dismutase activity by 30% (P < 0.01) and protected epidermal glutathione peroxidase and superoxide dismutase from depletion after UV irradiation. Total and reduced glutathione levels in the epidermis increased by 50% after the topical treatment (P < 0.05), as did dermal ascorbate levels (by 40%: P < 0.01). The topical treatment increased alpha-tocopherol levels both in the epidermis (62-fold) and the dermis (22-fold: P < 0.001 in each layer). Furthermore, alpha-tocopherol treatment significantly reduced the formation of epidermal lipid hydroperoxides after UV irradiation (P < 0.05). These results demonstrate that topical administration of alpha-tocopherol protects cutaneous tissues against oxidative damage induced by UV irradiation in vivo, and suggest that the underlying mechanism of this effect involves the up-regulation of a network of enzymatic and non-enzymatic antioxidants.

Administration, Cutaneous↗
PubMed1998

Difference in hepatic tissue oxygenation between total vascular exclusion and inflow occlusion of the liver and the possible role of hepatic venous blood under liver ischemia.

The difference between total vascular exclusion (TVE) and inflow occlusion (IO) of the liver was assessed by the extent of DNA injury in rats and by hepatic tissue oxygen saturation (SahtO2) in pigs. Moreover, the role of hepatic venous blood under liver ischemia was discussed. Seventy percent of the rat livers were exposed to complete IO (hepatic artery + portal vein) or to TVE (IO + hepatic vein) for 30 or 60 min. DNA strand breaks following blood flow interception were measured using the in situ nick translation technique as an indicator of liver damage. IO/TVE were performed on pigs as well under portosystemic bypass, and the oxygen saturation of the hepatic venous blood (SahvO2) was altered by changing the fraction of inspiratory oxygen or by oxygenating the inferior caval blood using an extracorporeal membrane oxygenator. The changes in SahtO2 were measured sequentially using near-infrared spectroscopy. The results were as follows: (1) DNA injury occurred more severely under TVE than under IO of the rat liver at the end of ischemia, as well as 30 min after revascularization. (2) SahtO2 during TVE was significantly lower than that during IO. (3) The increase in SahvO2 by oxygenation of the inferior caval blood resulted in the elevation of SahtO2 under IO. In conclusion, TVE could cause greater damage to the liver than IO due to the lack of the hepatic venous blood. Hepatic venous blood might play an important role in hepatic tissue oxygenation in the case of hepatic blood flow interception.

Animals↗
PubMed1998

Molecular analysis of suppression of interleukin-8 production by rebamipide in Helicobacter pylori-stimulated gastric cancer cell lines.

Interleukin-8 (IL-8) may play an important role in Helicobacter pylori infection-associated chronic active gastritis and peptic ulcer disease in human. We have recently reported that a gastric cancer cell line, MKN45, produced a massive amount of IL-8 upon coculture with live H. pylori. Moreover, H. pylori induced the activation of NF-kappaB as well as AP-1, leading to IL-8 gene transcription. In this study, we evaluated the effect of rebamipide, an antigastritis and antiulcer agent, on H. pylori-induced IL-8 production. Rebamipide inhibited the production of IL-8 in several gastric cancer cell lines infected with H. pylori. In addition, rebamipide suppressed H. pylori-induced IL-8 gene expression at the transcriptional level as revealed by northern blotting analysis and luciferase activity in cells that were transfected with a luciferase expression vector linked with a 5'-flanking region of the IL-8 gene (bp -133 to +44). Furthermore, rebamipide significantly suppressed the NF-kappaB activation by H. pylori infection. These results suggest that rebamipide may protect against the mucosal inflammation associated with H. pylori infection through inhibition of a proinflammatory cytokine, IL-8.

Alanine↗
PubMed1997

Calorimetric observation of a GroEL-protein binding reaction with little contribution of hydrophobic interaction.

Binding of Escherichia coli chaperonin, GroEL, to substrate proteins with non-native structure, reduced alpha-lactalbumin (rLA) and denatured pepsin, were analyzed by isothermal titration calorimetry at various temperatures in the presence of salt (0.2 M KCl). Both proteins bound to GroEL with 1:1 stoichiometry and micromolar affinity at all temperatures tested. However, thermodynamic properties of their binding to GroEL are remarkably different from each other. While heat capacity changes (DeltaCp) of rLA-GroEL binding showed large negative values, -4.19 kJ mol-1 K-1, that of denatured pepsin-GroEL binding was only -0.2 kJ mol-1 K-1. These values strongly indicate that the hydrophobic interaction is a major force of rLA-GroEL binding but not so for denatured pepsin-GroEL binding. When salt was omitted from the solution, the affinity and DeltaCp of the rLA-GroEL binding reaction were not significantly changed whereas denatured pepsin lost affinity to GroEL. Thus, in the non-native protein-GroEL binding reaction, thermodynamic properties, as well as the effect of salt, differ from protein to protein and hydrophobic interaction may not always be a major driving force.

Calorimetry↗
PubMed1997

Comparison of tracheal aspiration with other tests for diagnosis of Rhodococcus equi pneumonia in foals.

The diagnostic value of tracheal aspiration was evaluated through comparison with other diagnostic methods using an experimental model of Rhodococcus equi (R. equi) pneumonia in foals. Pneumonia was induced by spraying of the virulent R. equi strain ATCC 33701 into the trachea of foals. All foals developed fever from 11 to 16 days after bacterial inoculation. One foal was euthanized on day 26 due to its poor prognosis, and other foals euthanized on day 43. During the experiment, some tests for diagnosis of Rhodococcus equi pneumonia such as tracheal aspiration, radiography, serodiagnosis and fecal culture were carried out. R. equi was continually isolated from tracheal aspirates collected via a silicone catheter inserted transnasally on day 8 to day 32 after bacterial inoculation. On the other hand, radiography, serodiagnosis and fecal culture were demonstrated to be valuable diagnostic methods, but to be limited compared with tracheal aspiration. Indirect fluorescent antibody technique (IFA) using a monoclonal antibody against the 15- to 17-kDa virulence-associated antigens (VapA) of R. equi and PCR targeting the structural gene of VapA detected bacteria in tracheal aspirates less sensitively than the isolation technique although they were more rapid. Therefore, we conclude that a combination of tracheal aspiration and bacterial isolation was the most valuable method for routine diagnosis of R. equi pneumonia in foals.

Actinomycetales Infections↗
PubMed1997

Needle crystals of vitamin B2 induce polyploidy in Chinese hamster lung (CHL/IU) cells.

Induction of polyploidy by vitamin B2 (VB2) was investigated in cultured Chinese hamster lung (CHL/IU) cells. We report that VB2 in the form of needle crystals induces polyploidy via the formation of CHL/IU cells with more than one nucleus. The incidence of polyploid cells depended on the amount of needle crystals. No induction of polyploidy was observed when VB2 was used in solution. Electron-microscopic examination revealed that needle crystals adhered to the cell surface, and were enclosed by viscous cellular materials. These results indicate that needle crystals of VB2 have the ability to induce polyploidy in cultured CHL/IU cells, probably by physically fixing the shape of the cells and by this preventing normal mitosis.

Animals↗
PubMed1997

Time course of changes in antioxidant enzymes in human skin fibroblasts after UVA irradiation.

Examining damage (inactivation) of antioxidant enzymes in the cells and the pattern of recovery after a single UV exposure might be a useful method for analyzing the mechanisms of chronic UV irradiation, because chronic UV irradiation means repeated single exposures. We irradiated human skin fibroblasts with a single exposure to UVA (1, 6 or 12 J/cm2) and examined the time course of changes in antioxidant enzymes over several days. Only catalase activity was inactivated at the end of the irradiation (66% for 6 J/cm2, 53% for 12 J/cm2), recovering by day 5. Superoxide dismutase (SOD) activity decreased on day 3 (63% for 6 J/cm2, 72% for 12 J/cm2), and recovered on day 5, although it was not changed at the end of exposure. The activities of glutathione peroxidase (GSH-Px) and glutathione reductase (GR) were nearly unchanged by irradiation. If repeated UV exposures occur before the inactivated enzyme activities recover, cellular damage will be significant due to the lowered antioxidant defense system. We examined the rates of synthesis and degradation of catalase in response to UVA irradiation. Both synthesis and degradation rates were changed by irradiation. These data indicate that catalase activity was still low on day 2 due to the existence of inactivated catalase produced at the end of UV irradiation, and catalase activities recovered by day 5 due to a significant increase in the synthesis rate. To elucidate the role of bound NADPH in catalase in response to UV irradiation, we measured the NADPH released from catalase after UVA irradiation using bovine liver catalase. UVA irradiation caused a release of NADPH from catalase (25% for 12 J/cm2), but this was not directly related to the inactivation of catalase.

Catalase↗
PubMed1997

Immunogenetic study of sympathetic ophthalmia.

Sympathetic ophthalmia (SO) is very rare but it remains one of the most intractable eye diseases. In clinical manifestations and histopathologic features SO is known to resemble closely Vogt-Koyanagi-Harada's disease (VKH disease). We had reported that VKH disease was significantly associated with HLA-DRB1*04 and -DQB1*04 in Japanese patients. In this study, to investigate an HLA association with SO we performed HLA serological and PCR-based DNA typing in 16 patients and 50 healthy controls. Our study revealed that HLA-DRB1*04 (0405; Pc < 5 x 10(-4)), DQA1*03 (Pc < 5 x 10(-3)), and DQB1*04 (0401; Pc < 5 x 10(-4)) were significantly associated with SO as compared to the healthy controls but there was no significant difference in the frequencies of any DPB1 alleles between the patients and healthy controls. It can be postulated that not only the clinical manifestations but also the genetic predisposition of SO are very similar to those of VKH disease.

Female↗
PubMed1997

A strong association between HLA-B*5101 and Behçet's disease in Greek patients.

Behçet's disease is known to be associated with HLA-B51, one of the split antigens of HLA-B5, among many different ethnic groups. In a Greek population, an increased incidence of HLA-B5 in the patient group has also been reported. Because the B51 antigen has been recently identified to comprise seven alleles, B*5101-B*5107, we performed HLA-B51 allele genotyping by the PCR-SSP method as well as serological HLA-A and -B typing among 31 Greek patients with Behçet's disease to investigate whether there is any correlation between one particular B51-associated allele and Behçet's disease. The frequency of B51 was remarkably high (80.6%) in the patient group as compared to the ethnically matched control group (26.7%). In addition, HLA-A26 was also increased in the patients (29.0%) as compared with the healthy controls (3.3%). B51 allele genotyping revealed that all these B51-positive patients carried B*5101. This study revealed a strong association of Behçet's disease in Greeks with one of the B51 subantigens, providing insight into the molecular mechanism underlying an HLA association with Behçet's disease.

Behcet Syndrome↗