Integrated overlapping ventriculoplasty combined with papillary muscle plication for severely dilated heart failure.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to Yuji Naito.
Explore the source record for details and available documents.
The overproduction of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) may contribute to the pathophysiology of intestinal injury induced by ischemia-reperfusion. The aim of the present study was to examine the effect of selective iNOS inhibition by a cyclic amidine analogue, ONO-1714, on reperfusion-induced small intestinal injury and inflammation in rats. Intestinal damage was induced in male Sprague-Dawley rats by clamping both the superior mesenteric artery and the celiac trunk for 30 min, followed by reperfusion. The luminal nitrite concentration in the small intestine was measured by Griess reaction and the iNOS mRNA expression by RT-PCR. The severity of the intestinal mucosal injury and inflammation were evaluated by several biochemical markers and by the histological findings. The rats which were killed after ischemia-reperfusion had increased luminal concentrations of nitrite and iNOS mRNA expression, in addition to severe intestinal inflammation characterized by significant increases in myeloperoxidase activity, a marker of neutrophil infiltration, and by the mucosal content of CINC-1 cytokine, a neutrophil chemotactic cytokine. Administration with ONO-1714 significantly inhibited the luminal NO production. Reperfusion after 30-min ischemia resulted in an increase in luminal protein and hemoglobin concentrations, with levels reaching a maximum after 60 min of reperfusion. In contrast, pre-treatment with ONO-1714 2h before the ischemia inhibited the increases in luminal protein and hemoglobin concentration in a dose-dependent manner (0.001-0.1mg/kg). The contents of the thiobarbituric acid-reactive substances (a marker of oxidative lipid peroxidation) were significantly increased by ischemia-reperfusion, and this increase was reduced by ONO-1714. After reperfusion, the increase in tissue-associated myeloperoxidase activity, an index of neutrophil infiltration, was significantly inhibited by pre-treatment with ONO-1714. ONO-1714 also inhibited increases in intestinal CINC-1 protein and mRNA expression, as determined by ELISA and RT-PCR, respectively. In conclusion, the improvement of reperfusion-induced intestinal injury by ONO-1714 suggested that an excess of NO, produced by iNOS, may have contributed to the initiation/amplification of intestinal inflammatory injury by various mechanisms, including nitrosative and oxidative damage as well as the enhancement of inflammatory cytokine release.
We report a very rare case of acute aortic dissection of the ascending aorta, which ruptured to the left pleural cavity through the left-side congenital pericardial defect. A preoperative computed tomographic scan and a roentgenogram showed localized dissection of the ascending aorta and severely deteriorating left hemothorax, which required emergency operation. Intraoperative findings revealed the ruptured aortic dissection of the ascending aorta and the defect at the left-side pericardium, and a graft replacement of the ascending aorta was performed. It was considered that congenital pericardial defect complicates the diagnosis in a case of catastrophic intrapericardial hemorrhage.
1. Various chemokines, such as keratinocyte chemoattractant (KC), macrophage inflammatory protein (MIP)-1alpha and macrophage chemoattractant protein (MCP)-1, are involved in the pathogenesis of acute lung injury induced by bacterial endotoxin (lipopolysaccharide; LPS). Oxidative stress is an important regulator of the expression of these chemokines, whereas vitamin E protects against LPS-induced insults. In the present study, we determined the effects of 2-(alpha-D-glucopyranosyl) methyl-2,5,7,8-tetramethylchroman-6-ol (TMG), a novel water-soluble vitamin E derivative with excellent anti-oxidant activity, on acute lung injury induced by intratracheal instillation of LPS (125 micro g/kg) in mice. 2. When TMG was administered intratracheally and intravenously (0.1, 1.0 or 10 mg/kg), it dose-dependently decreased the infiltration of neutrophils into bronchoalveolar lavage fluid after LPS challenge. 3. Histological examination showed that treatment with TMG ameliorated the LPS-induced infiltration of neutrophils into the lungs. Furthermore, TMG attenuated the LPS-induced increase in pulmonary expression of KC, MIP-1alpha and MCP-1 at both the transcriptional and translational levels. 4. These results indicate that TMG is a possible treatment for acute lung injury, especially that caused by Gram-negative bacteria. The therapeutic effect of TMG may be mediated, at least in part, by suppression of the local expression of chemokines, possibly through its strong anti-oxidant activity.
The present study investigated whether Helicobacter pylori water extract induces the upregulation of intercellular adhesion molecule-1, vascular cell adhesion molecule-1 and E-selectin on human umbilical vein endothelial cells, using an ELISA. The nature of the substances mediating this upregulation was also analyzed. H pylori water extract derived from type strain (NCTC 11637) significantly upregulated intercellular adhesion molecule-1, vascular cell adhesion molecule-1 and E-selectin to the same extent as interleukin-1. Treatments with extracts from clinical strains showed no significant increases in expression of these adhesion molecules. In a fractionation study, approximately 7 kDa fraction showed peak activity. This activity was tolerant to heating and trypsin digestion. These results indicate that H pylori water extract contains water-soluble, low-molecular, nonprotein substances which induce upregulation of adhesion molecules on human umbilical vein endothelial cells, suggesting that products of H pylori may elicit gastric mucosal inflammation by promoting expression of endothelial adhesion molecules.
UNLABELLED: Although the gene expression patterns during the development of diabetic nephropathy have been studied in both rodent models and humans, only a small portion of the mRNAs expressed in the mesangium or in glomerular cells has been characterized. In the present study we report larger groups of transcripts displaying significant expression modulation in glomerular cells obtained from the early phase of diabetic nephropathy. METHODS: We used 12-week-old female db/db mice, a rodent model of type 2 diabetes, and their non-diabetic db/m litter-mates. Glomerular cells were obtained from the kidneys of mice by laser capture microdissection. Preparation of cRNA and target hybridization were performed according to the Affymetrix GeneChip Eukaryotic Small Sample Target Labeling Assay Protocol (Version II). The gene expression profile was determined by the mouse Expression Set 430A GeneChip. RESULTS: By comparison between db/m and db/db mice, 649 probes that increased in expression with the induction of diabetes and 340 probes that decreased in diabetic kidneys were identified. Although some of these genes have previously been shown to play an important role in diabetic nephropathy, the large majority of them have never been demonstrated to be regulated during the development of nephropathy. CONCLUSIONS: Although the precise involvement of these genes in diabetic nephropathy remains to be clarified, the data presented here will aid in the identification of genes that play a significant role in this pathological condition.
In ischemia-reperfusion (I/R)-induced tissue injury, oxygen radicals can be generated by several mechanisms. One of the important sources of oxygen radicals is thought to be mitochondrial respiration. The aim of this study was to investigate the antioxidative defense effect of the mitochondrial electron transport inhibitor, rotenone using the I/R-induced rat intestinal mucosal injury model in vivo. Intestinal ischemia was induced for 30 min by applying a small clamp to the superior mesenteric artery in rats. Rotenone at a dose of 100 mg/kg was given to rats orally 2 h before the ischemia. Intraluminal hemoglobin and protein levels, the mucosal content of thiobarbituric acid-reactive substances (TBARS), the mucosal myeloperoxidase activity, and the content of inflammatory cytokines (CINC-1, TNF-alpha) were all significantly increased from mean basal levels after 60 min of reperfusion. These increases after I/R were inhibited by treatment with rotenone at a dose of 100 mg/kg. Co-administration with succinate (100 mg/kg), a substrate of the mitochondrial electron transport system, cancelled significant reduction of intraluminal hemoglobin and mucosal TBARS treated with rotenone alone. The results of the present study indicate that rotenone inhibited lipid peroxidation and reduced development of the intestinal mucosal inflammation induced by I/R in rats. This investigation suggests that rotenone has potential as a new therapeutic agent for reperfusion injury.
Singlet oxygen is regarded as contributing to the pathogenesis of various diseases including light-induced skin disorders and inflammatory response. In this study, the correlation between singlet oxygen quenching activity (SOQA) of human serum and blood biochemistry or life-style was evaluated. Healthy volunteers were recruited and carried out a measurement of SOQA by using electron paramagnetic resonance (EPR) and a questionnaire survey about a smoking. It was demonstrated that major quenchers of singlet oxygen in serum are proteins, and small molecular anti-oxidants relatively play a minor role. SOQA of whole sera showed no correlation with protein concentration, but positively correlated with SOQA of small molecular fraction. In vitro studies demonstrated that the decrease of sulfhydryl groups by NO or superoxide significantly attenuated SOQA of albumin. Together, these results may imply that the underlying oxidative condition in each individual influences both small molecular antioxidant states and the sulfhydryl content of serum proteins. SOQA of sera from women with a smoking history was significantly lower compared to non-smoking women, suggesting that the smoking habit impaired the defense mechanism against singlet oxygen.
Recent investigations have demonstrated that the signaling of hypoxia-re-oxygenation is a major contributing pathway leading to gastric mucosal injury induced by stress, non-steroidal anti-inflammatory drugs, and Helicobacter pylori. The aim of the present study was to perform a gene expression analysis on the gastric mucosal cellular response to hypoxia-reoxygenation using a high-density oligonucleotide array. Cells were subjected to hypoxia with 95% N(2) and 5% CO(2) at 37 degrees C for 2 h. Reoxygenation was initiated by placing the cells in an environment of normoxia for 2 h. Total RNA was extracted, and differences in gene expression profiles between the normoxia and hypoxia-reoxygenation groups were investigated using a GeneChip of Rat Toxicology U34 array (Affymetrix). Hypoxia-reoxygenation up-regulated the stress-related genes (heat shock protein-70 [HSP-70], catalase). The enhanced expression of HSP-70 was confirmed by Western blot analysis. In conclusion, these results suggest that up-regulation of the HSP-70 gene after reoxygenation may play a role in maintaining cell survival and supporting cell function as a molecular chaperone.
The objectives were to determine the effects of alacepril, an angiotensin-converting enzyme inhibitor, on the expression of adhesion molecules and monocyte adherence to endothelial cells induced by 7-ketocholesterol (7-KC) and tumor necrosis factor (TNF)-alpha. We used human aortic endothelial cells (HAECs) and U937 monocytic cells. Surface expression and mRNA levels of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) were determined by EIA and RT-PCR. Adherence of U937 to HAECs was assessed by adhesion assay. Incubation of HAEC with 7-KC increased the surface expression of protein and mRNA levels of ICAM-1 and VCAM-1 on HAECs and the production of reactive oxygen species (ROS) in HAECs. Pretreatment with alacepril reduced the enhanced expression of these molecules in a dose-dependent manner. The inhibitory effect of alacepril against 7-KC or TNF-alpha-induced CAMs expression was stronger than that of captopril or enalapril. Alacepril inhibited the production of ROS in HAECs stimulated by 7-KC or TNF-alpha. These results suggest that alacepril works as anti-atherogenic agent through inhibiting endothelial-dependent adhesive interactions with monocytes induced by 7-KC and TNF-alpha.
Hypoxia--reoxygenation (H/R) occurs in both inflammatory spots and tumor tissues, sites in which damage is amplified either acutely or chronically through the infiltration of inflammatory cells. Interleukin-8 (IL-8) is a cytokine with chemotactic and angiogenic properties. This study was designed to investigate the effects of H/R on IL-8 production in the U937 human monocytic cell line. Two hours of hypoxia followed by 4 h of reoxygenation induced a significant increase in IL-8 protein production and IL-8 mRNA expression in U937 cells. Pretreatment with proteasome inhibitor (PSI), a peptide aldehyde known to inhibit the chymotrypsin-like activity of the 26S proteasome specifically, suppressed IL-8 protein production and IL-8 mRNA expression induced by H/R. The production of IL-8 protein induced by H/R was decreased by pioglitazone and 15-deoxy-Delta(12,14)-PGJ(2) (15d-PGJ(2)), which have been identified as peroxisome proliferator-activated receptorgamma (PPAR-gamma) ligands. Moreover, transfection of U937 cells with a dominant negative IkappaBalphaexpression vector (IkappaBalphaM) decreased IL-8 protein production induced by H/R. These results suggest that NF-kappaB and PPAR-gamma regulate H/R-stimulated IL-8 production in U937 cells.
The aim of the present study was to assess the expression of intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), monocytic adhesion of human aortic endothelial cells (HAECs), and the production of intracellular reactive oxygen species (ROS), when HAECs were stimulated by 7-ketocholesterol. 7-ketocholesterol enhances surface expression of ICAM-1 and VCAM-1 as determined by EIA, induces their mRNA expression by RT-PCR, and stimulates adhesiveness of HAECs to U937 monocytic cells. We confirmed up-regulation of ROS production of HAECs treated with 7-ketocholesterol. Although the surface expression of ICAM-1 and VCAM-1 on HAECs treated with 7-ketocholesterol increased in a time-dependent manner, alpha-tocopherol inhibited this increase of the surface expression of ICAM-1 and VCAM-1. In the monocytic adhesion assay, adhesion of U937 to HAECs treated with 7-ketocholesterol was enhanced, but monoclonal anti-ICAM-1 and VCAM-1 antibodies reduced the endothelial adhesiveness. In conclusion, this study suggests that the endothelial adhesiveness to monocytic cells that was increased by 7-ketocholesterol was associated with enhanced expression of ICAM-1 and VCAM-1 mediated by ROS production.
INTRODUCTION: Recent studies have demonstrated the anti-inflammatory action of 15-deoxy-Delta12,14-prostaglandin J(2) (15d-PGJ(2)), a derivative of the PGD(2) metabolic pathway. Acute inflammation, including neutrophil activation, plays a critical role in the pathogenesis of ischemia-reperfusion (I/R). The aim of the present study was to determine the effect of 15d-PGJ(2) on I/R-induced gastric mucosal injury in rats. METHODS: Gastric mucosal damage was induced in male Wistar rats by clamping the celiac artery for 30 min followed by reperfusion. 15d-PGJ(2) (0.01-1.0 mg/kg) was given to the rats intraperitoneally 1 h before the vascular clamping. The area of gastric mucosal erosions (erosion index) was measured. Thiobarbituric acid reactive substances (TBARS) and tissue-associated myeloperoxidase (MPO) activity were measured in the gastric mucosa as indices of lipid peroxidation and neutrophil infiltration. The expression of tumor necrosis factor-alpha (TNF-alpha) in gastric mucosa was measured by ELISA. In addition, to elucidate whether the protective effects of 15d-PGJ(2) are related to the activation of the PPAR-gamma receptor, we also investigated the effects of a PPAR-gamma antagonist, GW9662. RESULTS: After 60 min of reperfusion, the area of gastric erosion index had significantly increased from the mean basal levels. The increase in the erosion index was significantly inhibited by pretreatment with 15d-PGJ(2) in a dose-dependent manner. On the other hand, GW9662 reversed the protective effect of 15d-PGJ(2). The concentration of TBARS and MPO activity in the gastric mucosa were both significantly increased after I/R, and pretreatment with 15d-PGJ(2) significantly reduced these increases. The TNF-alpha content was significantly higher in the I/R group than in the sham-operated group. However, the increase in TNF-alpha was significantly inhibited by pretreatment with 15d-PGJ(2). CONCLUSIONS: 15d-PGJ(2) significantly inhibited the severity of acute gastric mucosal injury induced by I/R in rats through PPAR-gamma-dependent mechanisms. This effect may be due, in part, to a reduction in the infiltration of neutrophils into the gastric mucosa, possibly via the inhibition of inflammatory cytokine.
Synthetic peroxisome proliferator-activated receptor gamma (PPAR-gamma) ligands shown to induce adipocyte differentiation and increase insulin sensitivity, thiazolidinediones have recently been implicated as regulators of cellular inflammatory and ischemic responses. Thiazolidinediones inhibit the activity of a number of transcriptional factors, including nuclear factor-gammaB, activating protein 1, signal transducers and activated T cells, and early response gene 1 by either PPAR-gamma-dependent or -independent mechanisms. Recent experimental studies demonstrated a dramatic protection by thiazolidinediones against cardiac, gastrointestinal and lung injury after ischemia-reperfusion, in addition to a significant reduction in infiltrating neutrophils. These reports have hypothesized that the inhibition of neutrophil-mediated inflammation by thiazolidinediones is involved in the reduction of ischemia-reperfusion-induced tissue injury. Altogether, recent findings suggest that thiazolidinediones could represent a novel therapeutic approach to reducing or preventing reperfusion injury.
Red wine polyphenolic compounds have been demonstrated to possess antioxidant properties, and several studies have suggested that they might constitute a relevant dietary factor in the protection from coronary heart disease. The aim of the present study is to examine whether red wine extracts (RWE) can ameliorate oxysterol-induced endothelial response, and whether inhibition of adhesion molecule expression is involved in monocyte adhesion to endothelial cells. Surface expression and mRNA levels of adhesion molecules (intercellular adhesion molecule 1 and vascular cell adhesion molecule 1) were determined by ELISA and RT-PCR performed on human aortic endothelial cells (HAEC) monolayers stimulated with 7beta-hydroxycholesterol or 25-hydroxycholesterol. Incubation of HAEC with oxysterols (10 microM) increased expression of adhesion molecules in a time-dependent manner. Pretreatment of HAEC with RWE at final concentrations of 1, 10, and 100 ng/ml significantly inhibited the increase of surface protein expression and mRNA levels. Adherence of monocytes to oxysterol-stimulated HAEC was increased compared to that of unstimulated cells. Treatment of HAEC with RWE significantly inhibited adherence of monocytes. These results suggest that RWE works as an anti-atherogenic agent through the inhibition of endothelial-dependent adhesive interactions with monocytes induced by oxysterols.
Although edaravone (3-methyl-1-phenyl-pyrazolin-5-one), a newly developed radical scavenging agent, has been widely used for protection against ischemia-reperfusion (I-R) injury in patients with cerebral infarction, its effects on gastrointestinal I-R injury have not been evaluated. In the present study, we examined the effects of edaravone on experimental intestinal I-R damage in rats. In male Wistar rats with and without edaravone treatment, intestinal damage was induced by clamping the superior mesenteric artery for 30 min, followed by reperfusion. Edaravone was administered via intravenous infusion at 5 min before reperfusion was achieved by removal of the clamp. The rats were sacrificed after 60 min of reperfusion. Luminal protein and hemoglobin concentrations were measured as an index of mucosal injury and histological examination of hematoxylin and eosin-stained sections was performed. Thiobarbituric acid (TBA)-reactive substances and tissue-associated myeloperoxidase (MPO) activity were measured in the mucosa as indicators of lipid peroxidation and neutrophil infiltration, respectively. The mucosal concentration of cytokine-induced neutrophil chemoattractant (CINC)-1 (a member of the IL-8 family) was determined by enzyme-linked immunosorbent assay (ELISA). Additionally, CINC-1 messenger RNA (mRNA) was measured by the reverse-transcription polymerase chain reaction (RT-PCR). As a result, the levels of luminal protein and hemoglobin, TBA-reactive substances, and MPO activity were all increased significantly by I-R injury, and these increases were significantly inhibited by treatment with edaravone. Multiple erosions and bleeding were observed macroscopically after the small intestine was exposed to I-R injury, and these changes were inhibited by administration of edaravone. Microscopic I-R damage was also reduced by treatment with edaravone. CINC-1 protein and CINC-1 mRNA were both increased by I-R injury, while edaravone markedly reduced the levels of both protein and mRNA. In summary, these results suggest that edaravone can protect the small intestine against I-R injury by scavenging oxygen-derived free radicals.
Explore the source record for details and available documents.
Interleukin-6 (IL-6) is a multifunctional cytokine secreted by various cells, and is involved in the acute phase response and the immune response through T and B cell activation. To further define the role of IL-6 in intestinal inflammation, we studied the effects of dextran sulfate sodium (DSS) administration in mice with targeted deletions of the IL-6 gene. Acute colitis was induced in female IL-6-/- and IL-6+/+ mice by giving 4.5% DSS orally in drinking water for 8 days. The colonic mucosal injury and inflammation was evaluated based on survival rate, body-weight changes, total colon length and histological findings. Colonic mRNA expression for tumor necrosis factor (TNF)-alpha, IL-6, IL-10 and inducible nitric oxide synthase (iNOS) was measured by RT-PCR. Colonic IL-6 mRNA levels of wild-type mice continued to increase throughout the study period. At each assessment, colonic injury was significantly attenuated in DSS-treated IL-6-/- mice compared with DSS-treated IL-6+/+ mice. Histological study also showed a reduced infiltration of inflammatory cells, especially neutrophils, and mucosal cell disruption in DSS-treated IL-6-/- mice compared with DSS-treated IL-6+/+ mice. In the colons of DSS-treated IL-6-/- mice, the expression of both TNF-alpha mRNA and iNOS mRNA was reduced on day 5. In contrast, IL-10 mRNA expression was enhanced compared with DSS-treated IL-6+/+ mice. In conclusion, DSS-induced inflammation appears to be significantly inhibited in IL-6-/- mice compared to wild-type mice. These data suggest that persistent and marked blockade of IL-6 bioactivity provides some beneficial effects on intestinal inflammation.