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Biomedical subjects

K Yoshida

Publications and source records attributed to K Yoshida.

At least 19 recordsLinked to original sources
PubMed2007

Surgical resection of solitary adrenal metastasis from esophageal carcinoma following esophagectomy.

The prognosis of esophageal carcinoma following esophagectomy is poor due to a high frequency of metastasis to periesophageal lymph nodes and distant organs. However, we experienced a case with good prognosis following resection of a solitary adrenal metastatic tumor. The patient was a 70-year-old man diagnosed with type 2 esophageal cancer (Lt-Ae, T2N1M0, Stage IIB) who was treated with esophagectomy. Eight months following surgery, solitary adrenal metastasis was detected by CT, and was resected. At 42 months follow-up he has had a good quality of life in the community without evidence of recurrence. To the best of our knowledge, only five cases with resected solitary adrenal metastases including our case, have been reported, and show a greater than 1-year survival. Consequently, we suggest that resection of solitary organ metastases is a good alternative, even following esophagectomy.

Adrenal Gland Neoplasms↗
PubMed2006

NF-kappaB regulates the stability and activity of p73 by inducing its proteolytic degradation through a ubiquitin-dependent proteasome pathway.

Nuclear factor kappa B (NF-kappaB), which exists as heterodimeric complexes composed of p50 and p65, has been shown to play an important role in cell survival processes. In the present study, we found for the first time that NF-kappaB has an ability to induce the ubiquitin-dependent proteasomal degradation of proapoptotic p73alpha. The activation of NF-kappaB in tumor necrosis factor alpha (TNF-alpha)-stimulated H1299 cells resulted in a significant reduction in the amounts of the endogenous p73alpha. Consistent with these results, TNF-alpha-mediated downregulation of p73alpha was observed in wild-type (WT) mouse embryonic fibroblasts (MEFs) but not in p65-deficient MEFs. Ectopic expression of NF-kappaB decreased a half-life of p73alpha by increasing its ubiquitination levels, and thereby inhibiting the transcriptional activity as well as proapoptotic function of p73alpha, whereas NF-kappaB had undetectable effects on p53. Immunoprecipitation experiments demonstrated that, under our experimental conditions, NF-kappaB does not bind to p73alpha in mammalian cultured cells. In contrast to WT p65, the COOH-terminal deletion mutant of p65 (p65DeltaC) failed to reduce the expression levels of p73alpha, suggesting that NF-kappaB-mediated proteolytic degradation of p73alpha requires the transcriptional activity of NF-kappaB. Taken together, our present results imply that NF-kappaB-mediated degradation of proapoptotic p73 is a novel inhibitory mechanism of p73 that regulates cell survival and death.

Animals↗
PubMed2006

Touchdown of the Hayabusa spacecraft at the Muses Sea on Itokawa.

After global observations of asteroid 25143 Itokawa by the Hayabusa spacecraft, we selected the smooth terrain of the Muses Sea for two touchdowns carried out on 19 and 25 November 2005 UTC for the first asteroid sample collection with an impact sampling mechanism. Here, we report initial findings about geological features, surface condition, regolith grain size, compositional variation, and constraints on the physical properties of this site by using both scientific and housekeeping data during the descent sequence of the first touchdown. Close-up images revealed the first touchdown site as a regolith field densely filled with size-sorted, millimeter- to centimeter-sized grains.

Journal Article↗
PubMed2006

Improved photocatalytic activity of zeolite- and silica-incorporated TiO2 film.

Porous TiO2 film was prepared by sol-gel method from TiO2 sol containing polyvinylpyrolidone (PVP). Photocatalytic activity of the film was evaluated by the elimination rate of ethylene. Several adsorbents including zeolite and silica powders were incorporated into the TiO2 film. All the adsorbents enhanced the activity. The optimum adsorbent content was 0.005-0.01 g/ml of the coating sol solution. Silica provided better activity than zeolite. At high humidity and in dry air the activity decreased.

Catalysis↗
PubMed2006

Systematic search for gastric cancer-specific genes based on SAGE data: melanoma inhibitory activity and matrix metalloproteinase-10 are novel prognostic factors in patients with gastric cancer.

Gastric cancer (GC) is one of the most common malignancies worldwide. Genes expressed only in cancer tissue will be useful molecular markers for diagnosis and may also be good therapeutic targets. However, little is known about cancer-specific genes, at least in GC. In this study, we searched for GC-specific genes by serial analysis of gene expression (SAGE) data analysis and quantitative reverse transcription (RT)-PCR. Comparing GC SAGE libraries with those of various normal tissues in the SAGEmap database, we identified 54 candidate GC-specific genes. Quantitative RT-PCR analysis of these candidates revealed that APin protein (APIN), taxol resistance-associated gene 3 (TRAG3), cytochrome P450, family 2, subfamily W, polypeptide 1 (CYP2W1), melanoma inhibitory activity (MIA), matrix metalloproteinase-10 (MMP-10), dickkopf homolog 4 (DKK4), GW112, regenerating islet-derived family, member 4 (REGIV), and HORMA domain-containing 1 (HORMAD1) were expressed much more highly in GC than in 14 kinds of normal tissues. Immunohistochemical staining for MIA, MMP-10, and DKK4 was found in 47 (31.1%), 68 (45.0%), and two (1.3%) of 151 GCs, respectively, and staining for both MIA and MMP-10 was correlated with poor prognosis in advanced GC (P=0.0001 and 0.0141, respectively). Moreover, enzyme-linked immunosorbent assay showed high levels of MMP-10 (65/69, 94.2%) in serum samples from patients with GC. Levels of MIA were raised in a small proportion of serum samples from patients with GC (4/69, 5.8%). In Boyden chamber invasion assays, MIA-transfected GC cells were up to three times more invasive than cells transfected with empty vector. Taken together, these results suggest that MMP-10 is a good marker for the detection of GC and that MIA and MMP-10 are prognostic factors for GC. As expression of MIA and MMP-10 is narrowly restricted in cancer, these two molecules may be good therapeutic targets for GC.

Adult↗
PubMed2006

A practical tool to assess the incidence of nosocomial infection in Japanese intensive care units: the Japanese Nosocomial Infection Surveillance System.

SUMMARY: Infection control professionals have the means to calculate infection rates in their hospitals but not to assess them. They require a practical tool that enables them to compare observed infection rates with external standards. Based on the data obtained from the intensive care unit (ICU) component of the Japanese Nosocomial Infection Surveillance (JANIS) system, a spreadsheet was developed to calculate a standardized infection ratio (SIR) as a risk-adjusted indicator. Out of the factors associated with the development of nosocomial infections in a multi-variate analysis, the following three factors were selected for stratification: APACHE II score (0-10, 11-20, 21+), operation (yes, no) and ventilator use (user, non-user). Infection rates in 2001 were determined (per 1000 patient-days), stratified by the three factors, as a benchmark. The spreadsheet was designed to calculate SIRs on the basis of the Japanese benchmark infection rates using Microsoft Excel software. The user of the spreadsheet should input the number of observed nosocomial infections and patient-days by APACHE II score, operation and ventilator use. When applied to eight Japanese ICUs, the spreadsheet revealed relative differences and temporal changes in the incidence of nosocomial infections within these ICUs.

Adolescent↗
PubMed2006

Polyamines in renal failure.

The levels of polyamines (putrescine, spermidine and spermine) and polyamine oxidase in plasma of patients with chronic renal failure were determined. The level of putrescine was increased but the level of spermine was decreased in the plasma of these patients. The patients also had increased plasma polyamine oxidase activity leading to increased degradation of spermine. As acrolein was a major toxic compound produced from spermine by polyamine oxidase, the levels of free and protein-conjugated acrolein in plasma were also measured. Acrolein levels were enhanced in plasma of patients with chronic renal failure. The accumulated acrolein found as protein conjugates was equivalent to 170 microM, which was about 5-fold higher than in plasma of normal subjects. It was found that acrolein is mainly produced by spermine oxidase in plasma. An increase in putrescine, spermine oxidase and acrolein in plasma was observed in all cases such as diabetic nephropathy, chronic glomerulonephritis and nephrosclerosis. After patients with chronic renal failure had undergone hemodialysis, their levels of plasma polyamines, spermine oxidase and acrolein returned towards normal. It is likely that acrolein produced from spermine accumulates in the blood due to decreased excretion into urine and may function as a uremic "toxin".

Acrolein↗
PubMed2006

Multicentre prospective study of perinatal depression in Japan: incidence and correlates of antenatal and postnatal depression.

A multicentre study on the epidemiology of perinatal depression was conducted among Japanese women expecting the first baby (N = 290). The incidence rate of the onset of the DSM-III-R Major Depressive Episode during pregnancy (antenatal depression) and within 3 months after delivery (postnatal depression) were 5.6% and 5.0%, respectively. Women with antenatal depression were characterised by young age and negative attitude towards the current pregnancy, whereas women with postnatal depression were characterised by poor accommodation, dissatisfaction with sex of the newborn baby and with the emotional undermining. Antenatal depression was a major risk factor for postnatal depression.

Adult↗
PubMed2006

Requirement of STAT3 activation for maximal collagenase-1 (MMP-1) induction by epidermal growth factor and malignant characteristics in T24 bladder cancer cells.

Signal transducers and activators of transcription (STATs) are latent transcription factors that mediate cytokine- and growth factor-induced transcription. Constitutive activation of STAT3 has been shown in human cancers and transformed cell lines. We report that STAT3, but not STAT1 and STAT5, becomes phosphorylated in response to epidermal growth factor (EGF) and achieves maximal induction of collagenase-1 (MMP-1) transcription by interacting with c-JUN. Phosphorylation of STAT3 protein is biphasic: the first peak within 30 min and the second peak between 4 and 8 h. Association of STAT3 with c-JUN is detected and its constituting STAT3 is increasingly phosphorylated. The STAT and AP-1 elements are necessary for effective induction of MMP-1 promoter by EGF. Mutation of AP-1 element closely located at the STAT site abolishes the binding not only of c-JUN but also of STAT3 to MMP-1 promoter, resulting in the loss of the responsiveness to EGF. By blocking STAT3 activity with the dominant-negative form, we show the requirement of STAT3 for EGF induction of MMP-1 and MMP-10 (stromelysin-2). Furthermore, expression of the dominant-negative STAT3 is sufficient to inhibit the constitutive and EGF-inducible cell migration and invasion and the tumor formation in nude mice. These results demonstrate that STAT3 phosphorylation and its possible interaction with c-JUN are required for the strong responsiveness of MMP-1 to EGF, and STAT3 activation is crucial for exhibition of malignant characteristics in T24 bladder cancer cells.

Animals↗
PubMed2006

Experimental study of aortic anastomosis using a circular stapling device in the porcine model.

OBJECTIVES: The aim of this study was to assess the strength (pressure resistance) and histological findings of aortic anastomoses performed using a circular stapling device. MATERIALS AND METHODS: A circular stapling device was used for anastomosing a porcine aorta and a Dacron graft. The maximum pressure resistance of the anastomotic site of a porcine aortic specimen and a Dacron graft was examined (n=10). A porcine aorta with Dacron graft was anastomosed to a beating heart, and pressure overload was induced by adrenaline (n=5). Specimens of the anastomotic sites were harvested after 14 days and examined histologically. RESULTS: The maximum pressure resistance of the anastomotic site was 427.3+/-34.4 (375-511) mmHg. No anastomotic sites leaked as a result of pressure overloading at 227.6+/-21.1 (201-260) mmHg. Histologically, good incorporation and cell coverage were observed, and the inner surfaces of the anastomotic sites were smooth and without stenoses. CONCLUSIONS: Aortic anastomosis using a circular stapling device is feasible and worthy of further investigation.

Anastomosis, Surgical↗
PubMed2006

Tissue Doppler-derived index of left ventricular filling pressure, E/E', predicts survival of patients with non-valvular atrial fibrillation.

OBJECTIVES: To investigate whether the ratio of early transmitral flow velocity (E) to early diastolic mitral annular velocity (E') predict prognosis in patients with non-valvular atrial fibrillation. METHODS: 230 patients with non-valvular atrial fibrillation were enrolled and studied. According to E/E' value, patients were divided into groups with lower (group A with E/E' 15) E/E'. RESULTS: During follow up (average 245 days), 21 (9.1%) deaths were documented. All cause death (15/90 (16.7%) v 6/140 (4.3%)), cardiac death (10 (11.1%) v 2 (1.4%)) and congestive heart failure (16 (17.8%) v 8 (5.7%)) were more common in group B than in group A (all p < 0.01). A Kaplan-Meier survival curve showed that the cumulative survival rate was significantly lower in group B than in group A (log rank p = 0.0013). By multivariate logistic regression analysis, E/E' (chi(2) = 4.47, odds ratio (OR) 1.05, 95% confidence interval (CI) 1.01 to 1.11, p = 0.03) and age (chi(2) = 6.45, OR 1.06, 95% CI 1.01 to 1.11, p = 0.02) were independent predictors of mortality. CONCLUSION: The Doppler-derived index of left ventricular filling pressure, E/E', is a powerful predictor of the clinical outcome of patients with non-valvular atrial fibrillation.

Aged↗
PubMed2006

Down-regulation of the claudin-18 gene, identified through serial analysis of gene expression data analysis, in gastric cancer with an intestinal phenotype.

Gastric cancer (GC) is one of the most common malignancies worldwide. Genes whose expression is down-regulated in GC may be tumour suppressor genes. In the present study, genes with decreased expression in GC were screened for by serial analysis of gene expression (SAGE) data analysis and reverse transcription (RT)-polymerase chain reaction (PCR), and CLDN18 (encoding claudin-18) was identified. Quantitative RT-PCR revealed that expression of CLDN18 was down-regulated in 13 (56.5%) of 23 GCs. Immunostaining showed that normal gastric mucosa and Paneth cells of the duodenum expressed claudin-18 on cell membranes. Expression of claudin-18 was reduced in several intestinal metaplasias of the stomach. Of 20 samples of gastric adenoma, 18 (90.0%) showed decreased claudin-18 expression. Down-regulation of claudin-18 was observed in 84 of 146 GCs (57.5%) and correlated with poor survival in 65 advanced GCs (p = 0.0346). In addition, expression of the gastric and intestinal phenotypes of GC was examined by immunostaining for MUC5AC, MUC6, MUC2, and CD10. Of 38 GCs showing only the intestinal phenotype, down-regulation of claudin-18 was observed in 28 (73.7%), whereas in the remaining 108 GC cases, down-regulation of claudin-18 was observed in 56 (51.9%) (p = 0.0224). These results indicate that claudin-18 is a good marker of poor survival in GC. Down-regulation of claudin-18 may be involved in GCs with an intestinal phenotype, and may be an early event in gastric carcinogenesis.

Adenocarcinoma↗
PubMed2006

Dominant-negative c-Jun inhibits rat cardiac hypertrophy induced by angiotensin II and hypertension.

Cardiac activator protein-1 (AP-1), composed of c-Jun, is significantly activated by hypertension or angiotensin II (AngII). This study was undertaken to elucidate whether c-Jun could be the potential target for treatment of cardiac hypertrophy. We constructed recombinant adenovirus carrying dominant-negative mutant of c-Jun (Ad.DN-c-Jun). Using catheter-based technique of adenoviral gene transfer, we achieved global myocardial transduction of DN-c-Jun in rats, to specifically inhibit cardiac AP-1. (1) AngII (200 ng/kg/min) infusion in rats caused cardiac hypertrophy, increased cardiac p70S6 kinase activity by 1.3-fold (P<0.05) and enhanced the gene expression of cardiac hypertrophic markers. Ad.DN-c-Jun, which was transferred to the heart 2 days before AngII infusion, prevented cardiac hypertrophy (P<0.01), decreased p70S6 kinase phosphorylation (P<0.05), and suppressed cardiac gene expression of brain natriuretic peptide, collagen I, III, and IV, monocyte chemoattractant protein-1 (MCP-1) and plasminogen activator inhibitor-1 (PAI-1) (P<0.01). (2) In genetically hypertensive rats with cardiac hypertrophy, cardiac gene transfer of Ad.DN-c-Jun, without affecting hypertension, regressed cardiac hypertrophy (P<0.05), and suppressed p70S6 kinase phosphorylation by 20% (P<0.05) and suppressed the enhanced expression of collagen I, III, and IV, MCP-1 and PAI-1. These results provided the first evidence that in vivo blockade of cardiac c-Jun inhibits pathologic cardiac hypertrophy.

Adenoviridae↗
PubMed2006

Feasibility of using collagen as the base of the antifungal drug, miconazole.

The feasibility of using collagen as the base of miconazole was investigated. The addition of 33% collagen to a miconazole solution did not affect the minimal inhibitory concentration (MIC80) of the miconazole solution for Candida albicans. When 1 microg mL(-1) of miconazole in 33% collagen solution was plated on resin discs and dried to yield a thin membrane, the growth of C. albicans on the resin discs was nearly completely inhibited. In addition, we compared the antifungal effect of this collagen solution that contained 1 microg mL(-1) miconazole, with the antifungal effect of miconazole gel that had been diluted with glycerol (the main component of miconazole gel) to yield a final concentration of 1 microg mL(-1) of miconazole; as a result, we found that the collagen solution containing 1 microg mL(-1) miconazole had a stronger antifungal effect. In conclusion, our results demonstrated that it may be feasible to use collagen as the base of miconazole instead of glycerol, and suggest that a collagen-based miconazole solution would have a stronger antifungal effect than commercially available miconazole gel. Collagen-based miconazole solution may be useful for the treatment of Candida-associated denture stomatitis.

Antifungal Agents↗
PubMed2006

Iron overload and antioxidative role of perivascular astrocytes in aceruloplasminemia.

Aceruloplasminemia (ACP) is an inherited disorder of iron metabolism caused by the lack of ceruloplasmin activity; the neuropathological hallmarks are excessive iron deposition, neuronal loss, bizarrely deformed astrocytes, and numerous 'grumose or foamy spheroid bodies (GFSBs)'. We histopathologically examined two autopsied ACP brains, and observed for the first time that GFSBs form in clusters at the ends of perivascular astrocytic foot processes. Both the deformed astrocytes and the GFSBs contained ferric iron and were intensely immunolabelled with antibodies against the antioxidant proteins ferritin and manganese superoxide dismutase (Mn SOD). Ceruloplasmin is largely produced by perivascular astrocytes in the central nervous system and exhibits a ferroxidase activity that inhibits iron-associated lipid peroxidation and hydroxyl radical formation; therefore, the lack of ceruloplasmin causes direct oxidative stress on astrocytes. The intense immunolabelling of ferritin and Mn SOD most likely reflects a defensive response to iron-mediated oxidative stress. This study suggests that astrocytes play key roles in iron trafficking and the detoxification of iron-mediated free radicals at the blood-brain barrier and in the parenchyma in ACP brain. The antioxidative ability of astrocytes is one of their essential neuroprotective effects, and the decompensation of this ability may lead to secondary neuronal cell death in ACP.

Antioxidants↗
PubMed2006

Impact of body mass index on cholesterol of Japanese adults.

There have been few studies that examine the relation between body mass index (BMI) and cholesterol in consideration of potential interactions between age, sex, BMI and cholesterol. We determined age-, sex- and BMI-specific cholesterol levels of Japanese adults using the 2001 health examination data (337,690 men and 293,918 women). Both total cholesterol (T-C) and low-density lipoprotein cholesterol (LDL-C) levels increased with age until 50 years of age in men and until 60 years of age in women. Linear regression analysis showed significant BMI-dependent increases of T-C and LDL-C in all age groups, but the regression coefficients of BMI in relation to T-C and LDL-C became lower in older age groups until 60 years of age, with the highest value at ages 20-29 years in men and at ages 30-39 years in women. This result was consistent with the result of multiple logistic regression analysis regarding the risk of having hypercholesterolaemia. Weight reduction should be more strongly recommended to younger people, especially men aged under 40 years and women aged under 50 years, to prevent developing hypercholesterolaemia.

Adult↗
PubMed2006

Esophageal carcinosarcoma with intramural metastasis.

A case of esophageal carcinosarcoma is described herein. A 58-year-old man presented with dysphagia and was admitted to our hospital. Imaging studies revealed a type 3 tumor in the upper intrathoracic esophagus with direct invasion to the left main bronchus. Analysis of a biopsy specimen revealed carcinosarcoma. The patient underwent esophageal bypass and chemoradiotherapy. Eight months after surgery, he died of esophago-bronchial fistula. Autopsy examination revealed liver metastasis, peritoneal dissemination and intramural metastasis. The sarcomatous component was predominant in the intramural and liver metastatic lesions.

Biopsy↗