Publications by authors named "Masahito Hagio"

In this study, we developed an analytical method for simultaneous determination of 14 quinolones and 4 tetracyclines in livestock and fishery products using LC-MS/MS. The analytes were extracted from food samples with citrate buffer (containing EDTA)-methanol-acetonitrile (3 : 1 : 1, v/v/v) in the presence of n-hexane, and the extract was purified with an Oasis PRiME HLB cartridge column. It was suggested that this analytical method can also extract analytes from solid samples containing fat by using n-hexane.

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Background/aim: Οverweight and obesity are risk factors for chronic diseases. Dietary calcium has been reported to exert anti-obesity effects. However, the complex modulating effects of calcium intake on obese mice have not been clarified.

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There is an increasing need to explore the mechanism of the progression of non-alcoholic fatty liver disease. Steroid metabolism is closely linked to hepatic steatosis and steroids are excreted as bile acids (BAs). Here, we demonstrated that feeding WKAH/HkmSlc inbred rats a diet supplemented with cholic acid (CA) at 0.

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Background: Previously, we found a significant relationship in a rat study between energy intake and bile acid (BA) metabolism especially 12α-hydroxylated (12αOH) BAs. The present study was designed to reveal relationships among BA metabolism, glucose tolerance, and cecal organic acids in rats fed a high-fat and high-sucrose diet (HFS) by using multivariate and multiple regression analyses in two types of glucose tolerance tests (GTTs).

Methods: Male WKAH/HkmSlc rats were fed with a control or a HFS for 13 weeks.

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We developed new gossypol (Gos)-based glycoconjugates through dehydration condensation of native Gos and chemically modified glycosides having aminooxy groups. The resultant glycoconjugates (glycoGos) were resistant to hydrolysis, although they were light-sensitive and slowly decomposed even under indoor lighting. The glycoGos also exhibited improved water solubility compared with native Gos, but their saturated concentrations in water were still low (6.

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Understanding the dynamics of secondary bile acid (SBA) formation in the gut by SBA-producing bacteria is important for host health, as SBAs have been shown to affect host pathophysiology and gut microbiota composition. However, our knowledge of SBA producers is limited in light of the diversity of gut microbes. Here, we isolated six novel SBA-producing bacteria from rat cecal contents, all of which were members of known species of gut microbes.

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The signal molecule, 3-oxo-C12-homoserine lactone (3-oxo-C12-HSL), is similar to a mammalian hormone in bacteria. Although most studies have examined the effects of high 3-oxo-C12-HSL concentrations (>200 μM) on mammalian cellular functions because ~600 μM 3-oxo-C12-HSL can be secreted in biofilms of Pseudomonas aeruginosa grown in vitro, we previously showed that a low 3-oxo-C12-HSL concentration (30 μM) induces the apoptosis of undifferentiated Caco-2 cells through suppressing Akt activity. Here, we found that a low concentration of 3-oxo-C12-HSL-activated ERK1/2 in undifferentiated Caco-2 cells.

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Nestin, a class VI intermediate filament, was first described as a neuronal stem/progenitor cell marker. We previously reported that knockdown of nestin expression in human glioblastoma cells suppresses cell proliferation, migration, and invasion. In the present study, we examined the effect of nestin on stemness, and identified molecules involved in modulating nestin function in glioblastoma cells.

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Consumption of a high-fat diet increases some secondary bile acids (BAs) such as deoxycholic acid (DCA) in feces. DCA is derived from cholic acid (CA), a primary BA. We evaluated intestinal epithelial proliferation and BA metabolism in response to oral administration of cholic acid (CA) in rats to determine the influence of a CA diet on the responses of gut epithelia to γ-rays.

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To evaluate the effects of lutein-fortified milk administration on running exercise, a voluntary wheel-running model was performed in rats. Four-week-old F344 rats were administered test milk (10 mL/kg) daily following a 4-h fasting period, and their running distances were measured each day for a 9-week period. Total weekly running distance significantly increased from the sixth week until the end of the test period in lutein-supplemented rats (lutein-fortified milk administered) compared with control rats (vehicle administered).

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Obesity is increasingly becoming associated with increased risk of atherosclerosis. Serum levels of the bile acid deoxycholic acid (DCA) are elevated in mice with obesity induced by a high-fat (HF) diet. Therefore, we investigated the influence of DCA on the functions of vascular smooth muscle cells (VSMCs) because the initiation and progression of atherosclerosis are associated with VSMC proliferation and migration.

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Dipeptidyl peptidase IV (DPPIV) degrades some peptide hormones and cytokines, resulting in homeostatic modulation. However, the role of DPPIV in inflammatory bowel diseases remains controversial. To determine the role of DPPIV in colitis, we used F344/DuCrlCrlj (F344/Du) rats as a DPPIV-deficient model.

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Abnormal vasculature, termed tumor vessels, is a hallmark of solid tumors. The degree of angiogenesis is associated with tumor aggressiveness and clinical outcome. Therefore, exact quantification of tumor vessels is useful to evaluate prognosis.

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The annual incidence of pancreatic carcinoma has been increasing worldwide, and the overall 5-year survival rate has remained at approximately 5%. We re-evaluated 30 autopsy cases histologically diagnosed as pancreatic carcinoma from 1994 through 2010 at Nippon Medical School Hospital. The mean patient age was 69.

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Nestin, a class VI intermediate filament, is a neuronal stem/progenitor cell marker that is also expressed by various types of cancer, including pancreatic ductal adenocarcinoma (PDAC). We previously detected nestin expression in approximately 30% of PDAC cases, and found that nestin promotes the migration, invasion and metastasis of cells. Findings of recent studies have shown that epithelial mesenchymal transition (EMT) is important in the invasion and migration of cancer.

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Recently, we discovered that bile acid, a main component of bile, is a host factor that regulates the composition of the cecal microbiota in rats. Because bile secretion increases on a high-fat diet and bile acids generally have strong antimicrobial activity, we speculated that bile acids would be a determinant of the gut microbiota in response to a high-fat diet. The observed changes in the rat cecal microbiota triggered by cholic acid (the most abundant bile acid in human biliary bile) administration resemble those found in animals fed high-fat diets.

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Cancer stem cells (CSCs) play pivotal roles in cancer growth, invasion, metastasis and recurrence. Several proteins have been reported as CSC markers for pancreatic ductal adenocarcinoma (PDAC). In the present study, we examined the correlation between pancreatic intraepithelial neoplasias (PanINs) and CSC markers including CD24, CD44, CD133, CXCR4, ESA and nestin using immunohistochemical analysis.

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Bile acids (BAs) are considered to be promotive factors in colorectal carcinogenesis. We investigated whether BAs in the cellular environment influence proliferation of intestinal epithelial cell lines. Some BAs induced proliferation in several epithelial cell lines.

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A high percentage of colorectal carcinomas overexpress a lot of growth factors and their receptors, including fibroblast growth factor (FGF) and FGF receptor (FGFR). We previously reported that FGFR2 overexpression was associated with distant metastasis and that FGFR2 inhibition suppressed cell growth, migration, and invasion. The FGFR2 splicing isoform FGFR2IIIb is associated with well-differentiated histologic type, tumor angiogenesis, and adhesion to extracellular matrices.

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Background & Aims: Alterations in the gastrointestinal microbiota have been associated with metabolic diseases. However, little is known about host factors that induce changes in gastrointestinal bacterial populations. We investigated the role of bile acids in this process because of their strong antimicrobial activities, specifically the effects of cholic acid administration on the composition of the gut microbiota in a rat model.

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Fibroblast growth factor receptor 2 (FGFR2) is considered a novel therapeutic target for various cancer. We used a silencing strategy to clarify the effect of reduced FGFR2 expression in human colorectal cancer (CRC) cells. The invasive front of cancer cells exhibited stronger FGFR2 expression than the surface area of the cancers.

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In recent years, bile acids (BAs) have received much attention as signaling molecules as well as biosurfactants for lipophilic nutrients. To understand exact BA behavior, the precise distribution of BAs in vivo must be determined. However, to date, it has been difficult to know the precise roles of BA due to variations in BA molecules including conjugated forms.

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According to epidemiologic studies, a negative correlation exists between exercise amount and subsequent cancer development risk in the large intestine. The proportion of secondary bile acids (SBA) in the large intestine is related to subsequent risk for colorectal carcinogenesis. The aim of this study was to investigate the effects of voluntary wheel running exercise and dietary intervention on bile acid (BA) metabolism in the large intestine.

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Background: Fucoxanthin isolated from edible seaweeds and its metabolite fucoxanthinol have been recently found to have anti-obesity effects, but the mechanism is not fully understood.

Aim Of Study: We investigated the effects of these carotenoids on the absorption of triglycerides in conscious rats implanted with cannulae into a lymph duct and the portal or jugular vein.

Methods: A duodenal infusion of 1 ml of test oil emulsion with or without 2 mg of fucoxanthin or fucoxanthinol was administered in the lymph duct and the portal (Experiment 1) or the jugular vein (Experiment 2) cannulated rats.

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