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Biomedical subjects

Toshifumi Hibi

Publications and source records attributed to Toshifumi Hibi.

At least 37 records · Page 2Linked to original sources
PubMed2006

An inverse association between serum gamma glutamyl transpeptidase activity and Breslow's Lifestyle Index; its practical application for screening of subjects with unhealthy lifestyles.

We examined whether serum gammaGTP activity (gammaGTP) is associated with Breslow's lifestyle index and whether it could be used as a tool to detect subjects with unhealthy lifestyles. To that effect, 724 male Japanese workers excluding patients suffering from hepatitis virus infection, autoimmune liver diseases and apparently active bile duct diseases were cross-sectionally examined. gammaGTP was inversely associated with the total score of Breslow's index for all subjects (lambda=30.643) and in subjects aged 40 or more (lambda=37.073). The association was consistent even after adjustments of subjects' ages and levels of triglycerides, total cholesterol and uric acid (p=0.0001). Among the seven lifestyle factors comprising Breslow's index, improper habits of drinking (p<0.0001), smoking (p=0.0204), exercise (p=0.0189) and body weight control (p<0.0001), were associated with increased gammaGTP. Even in a survey in which subjects who had proper habits of drinking and body weight control were selectively examined, improper habits of smoking and exercise still tended to be associated with increased gammaGTP. Receiver operating characteristic curves indicated that gammaGTP was beneficial for detecting subjects who scored two or less on Breslow's index, at least in subjects aged 40 or more. gammaGTP was associated with insulin resistance level estimated by the homeostasis model assessment (p<0.0001), which was inversely associated with Breslow's index (p=0.0040). gammaGTP could be used as an objective substitute of Breslow's index, allowing us to identify subjects with low scores on Breslow's index, at least after sorting subjects properly. Such screening would enable interventions to correct subjects' unhealthy lifestyles, helping to solve lifestyle-related disease issues.

Adult↗
PubMed2006

Induction therapy with twice-daily interferon-beta does not improve the therapeutic efficacy of consensus interferon monotherapy for chronic hepatitis C.

We examined therapeutic superiority of induction therapy with twice-daily IFN-beta (3X2=6 million units/day) onto 6-months consensus interferon monotherapy for chronic hepatitis C. Patients were randomly assigned to monotherapy without (group I, n=16) and with induction therapy (group II, n=12). The mean age of group II was older than that of group I, and other baseline condition was not statistically significant. Sustained virological response (SVR) rates of group I and II were 81.3% (13/16) and 58.3% (7/12), respectively (p=0.365). SVR rates in patients with genotype 1b were 66.7% (4/6) and 0% (0/2, because of drop-out), and those with high viral load were 70% (7/10) and 75% (6/8) in group I and II, respectively (p=1.000). Drop-out rates during therapy were 6.3% (1/16) and 33.3% (4/12) in group I and II, respectively (p=0.176). Age less than 50 years was the only independent factor that was shown by multivariate logistic model analysis to be associated with a sustained virological response. Although randomization failed to produce and equal age distribution in the two groups in this study, our results suggest that induction therapy with twice-daily IFN-beta has no beneficial effect on the efficacy of monotherapy with consensus interferon, probably because of the higher drop-out rates and incidence of adverse reactions with induction therapy.

Female↗
PubMed2006

Analysis of Toll-like receptor 2, 4, 6 and 9 genome DNA mutations in patients with tractable and intractable gastric mucosal diseases.

The possible involvement of Toll-like receptor (TLR) genome DNA in the prolongation and relapse of inflammatory intestinal diseases and alcoholic hepatic diseases has been reported. In this study, we examined the relationship of mutations of the TLR 2, 4, 6 and 9 genomic DNA to recurrent or intractable gastritis or gastric ulcers. The subjects were 32 patients, including 6 with H. pylori (Hp)-positive gastritis, 4 with Hp-negative gastritis, 10 with Hp-positive tractable gastric ulcer, 5 with Hp-positive recurrent gastric ulcer after Hp eradication, and 7 with Hp-negative easily recurrent gastric ulcer after Hp eradication. Gastric mucosal tissue and peripheral blood specimens were collected from each of the patients. DNA was extracted from the tissue and blood specimens and subjected to electrophoresis by the PCR method, using the oligonucleotide primers of TLR 2, 4, 6 and 9. The gastric mucosal tissue specimens were collected endoscopically from the sites of the lesions. Subsequently, the presence or absence of genomic DNA mutations in the blood and tissue specimens was examined using a DNA sequencer. TLR 2, 4, 6 or 9 DNA mutations were not observed in any of the gastric mucosal or peripheral blood specimens obtained from patients with tractable gastritis or gastric ulcer, or from those with intractable gastric ulcer who were Hp-positive or Hp-negative or had become Hp-negative after eradication therapy. These data suggest that mutations of the TLR 2, 4, 6 and 9 genome DNA may not be involved in the recurrence, delayed healing or intractability of gastritis and gastric ulcers.

Base Sequence↗
PubMed2006

Attenuating effect of Myakuryu on mesenteric microcirculatory disorders induced by ischemia and reperfusion.

Myakuryu (MR) is a newly developed herbal medicine composing Crataegue oinnatifida bge (COB), Panax notoginseng (PN) and Ginkyo biloba (GB). To examine the effectiveness of MR, we investigated its effects on rat mesenteric microcirculatory injury induced by ischemia/reperfusion (I/R). The mesenteric microcirculation of ileocecal portion of a male Wistar rat was observed through an inverted-type intravital microscope assisted with a charge-coupled devise (CCD) camera. Mesenteric I/R was conducted by a ligation of the mesenteric artery and vein (10 min) and subsequent release of the occlusion. We measured venular diameter, the number of adherent leukocytes, dihydrorhodamine 123 (DHR) fluorescence as an indicator of oxidative stress and mast cell degranulation, with or without MR extract (0.4 g/kg b.w.) via an orogastric tube 1 hr before I/R. The diameters of the observed mesenteric venules were not changed after the mesenteric I/R. MR had no effect on venular diameter. The leukocytes adhering to the post-capillary venular walls started just after reperfusion, and increased thereafter. The increased number of adherent leukocytes was significantly reduced by treatment with MR. DHR fluorescence ratio was significantly increased along the venular wall. MR attenuated the increased oxidation. The mesenteric I/R induced mast cell degranulation. The increase in mast cell degranulation was inhibited by MR. In conclusion, oral administration of MR attenuates I/R-induced microvascular damages in rat mesentery. MR has a therapeutic potential for prevention of I/R-related microvascular injury.

Animals↗
PubMed2006

[Drug therapy for non-alcoholic steatohepatitis].

Nonalcoholic steatohepatitis (NASH) once considered a benign process is now known to lead to progressive fibrosis and cirrhosis. NASH is frequently associated with the metabolic syndrome. Gradual weight reduction and increased physical activity are always recommended in overweight patients, but not always effective in reversing NASH. Promising pharmacological treatments have been demonstrated with antioxidants, insulin sensitizers, hepatoprotectants, lipid-lowering agents, and antihypertensive drugs. The similar histological features and natural histories of alcoholic steatohepatitis (ASH) and NASH suggest that common pathogenic mechanisms might be involved in these two conditions. Therapeutic strategies targeting the common mechanisms may also have promising potential. A larger randomized-controlled trial is needed to definitively determine the efficacy of pharmacological treatments for NASH.

Antihypertensive Agents↗
PubMed2006

Heterozygous Thr 135 Ala polymorphism at leucine-rich repeat (LRR) in genomic DNA of toll-like receptor 4 in patients with poorly-differentiated gastric adenocarcinomas.

The genomic DNA of toll-like receptor (TLR) 2, TLR4, radioprotective 105, TLR6, and TLR9 were examined for mutations in 48 patients with gastric cancer. Of these, 22 had well-differentiated and 20 had poorly-differentiated adenocarcinomas, the latter group including 10 with signet ring cell carcinomas. The remaining 6 had gastric adenomas. Ten healthy volunteers with no family history of malignant diseases served as controls. DNA was extracted from peripheral blood and subjected to electrophoresis using PCR oligonucleotide primers. The resultant gel was analyzed with a DNA sequencer. None of the healthy volunteers, patients with gastric adenomas or those with well-differentiated gastric adenocarcinomas showed mutations. However, 8 of the 20 with poorly-differentiated gastric adenocarcinoma showed heterozygosity at the 135th position of the amino acid sequence of TLR4, and a mutation from threonine to alanine was found at this site. Analysis of the entire available amino acid sequence of TLR4 revealed that this mutation occurred at a leucine-rich repeat corresponding to one of its extracellular components. This suggests a disturbance in the protein phosphorylation reaction of TLR4, and that this disturbance is related to the development of poorly-differentiated gastric adenocarcinomas.

Adenocarcinoma↗
PubMed2006

Cyclooxygenase-2 inhibitor and interferon-beta synergistically induce apoptosis in human hepatoma cells in vitro and in vivo.

Recent clinical trials have shown that interferon (IFN) is effective for chemoprevention against hepatocellular carcinoma (HCC). However, it remains controversial as to whether IFN exerts direct cytotoxicity against HCC. Cyclooxygenase (COX)-2 also plays a role in hepatocarcinogenesis and may mediate resistance to apoptosis in HCC. Therefore, we aimed to elucidate the combined effect of COX-2 inhibitor, NS-398, and IFN on in vitro growth suppression of HCC using 3 hepatoma cell lines (HepG2, PLC/PRF/5, and Huh7) and in vivo nude mouse xenotransplantation model using Huh7 cells. Only minimal growth inhibition was observed after treatment with IFN-beta alone in the 3 hepatoma cell lines. In contrast, treatment with NS-398 and IFN-beta synergistically inhibited cell proliferation in dose- and time-dependent manner. Apoptosis was identified by 4',6-diamidino-2-phenylindole dihydrochloride and fluorescent staining. IFN-beta up-regulated the expression of TRAIL, while NS-398 increased the expression of TRAIL receptors (especially of death receptor 5). Subsequently, activation of caspase-8 and caspase-3 was observed following the treatment with NS-398 and IFN-beta. Blockade of TRAIL with a specific antibody attenuated this apoptosis. Furthermore, we found that IFN-beta up-regulated COX-2 expression in Huh7 cells, and NS-398 might suppress the up-regulated COX-2 activity downstream of IFN signaling. In vivo experiment showed the combined regimen with NS-398 and IFN-beta reduced the growth of xenotransplated HCCs in nude mice. In conclusion, NS-398 is sufficient to overcome IFN resistance in hepatoma cells through the TRAIL/TRAIL receptor pathway, therefore, the combination would appear to be a new therapeutic regimen for HCC.

Animals↗
PubMed2006

[Ghrelin - a novel appetite-stimulating hormone which also affects gastrointestinal functions].

Ghrelin, a novel gastrointestinal peptide with 28 amino acids, is secreted from the A-like cells of the gastric fundus. This peptide hormone does not only promote the release of growth hormone, but also stimulates food intake, gastric motility and cardiac output. Increased plasma ghrelin level has been reported in patients with upper gastrointestinal (GI) disease or in their disease animal model, suggesting its important role in the pathogenesis of upper GI disease.

Appetite↗
PubMed2006

Analysis of the differences in structural chromosomal aberrations of the gastric mucosa between H. pylori positive and negative gastric cancer patients: involvement of H. pylori in the onset of gastric cancer and examination of the mechanism in gastric carcinogenesis following H. pylori eradication.

Gene mutations are essential to carcinogenesis. If an evident difference is observed in gastric mucosal chromosomal structure aberrations between H. pylori (Hp)-negative and Hp-positive gastric cancer patients, it may be interpreted as suggesting the involvement of Hp in gene mutations. This study was undertaken to compare chromosomal structural aberrations between Hp-negative and Hp-positive gastric cancer patients and to evaluate the effects of Hp eradication on chromosomal structures in clinical cases. The subjects of this study were 40 patients with gastric cancer divided into four groups: Group A was composed of 12 patients with Hp-negative gastric cancer (well-differentiated gastric cancer in 5 cases and poorly-differentiated in 7 cases), Group B of 8 patients with Hp-negative gastric cancer following Hp eradication (well-differentiated in 4 case and poorly-differentiated in 4 cases), Group C of 13 patients with Hp-positive gastric cancer (well-differentiated in 7 cases and poorly-differentiated in 6 cases) and Group D of 7 patients with gastric cancer (well-differentiated in 5 cases and poorly-differentiated in 2 cases) undergoing Hp eradication at subtotal gastrectomy. In each of the groups A, B and C, the structural chromosomal aberration such as loss of heterozygosity (LOH) and microsatellite instability (MSI) was analyzed. In Group D, changes in structural chromosomal aberrations after Hp eradication as compared to the pre-eradication structures were also analyzed. LOH and MSI were examined by PCR, using DNA extracted from the cancer-affected and intact gastric mucosal tissue specimens from each patient. In A, B and C groups, structural chromosomal aberrations were noted, and these aberrations tended to be more marked in cases of poorly-differentiated gastric cancer in each group. In terms of structural chromosomal aberrations, there was no marked difference between Group A and either Group B or C. Hp eradication resulted in no change in chromosomal structure as compared to the pre-eradication structure in Group D. These results suggest the possibility that Hp eradication does not affect chromosomal structures and Hp is involved in gastric carcinogenesis as an additive environmental factor rather than as a factor acting at the gene level.

Anti-Bacterial Agents↗
PubMed2006

[A case of intrahepatic cholangiocarcinoma effectively treated by hepatic arterial infusion chemotherapy].

The patient was a 50-year-old woman who suffered from gastric discomfort. She was first diagnosed as intrahepatic cholangiocarcinoma with hepatic, paraaortic lymphnodal and bone metastasis. Initial systemic chemotherapy using gemcitabine (GEM) and 5-FU failed to control the disease activity. Then she was given GEM and cisplatin (CDDP) combination chemotherapy. The response was assessed as stable disease (SD), but grade 4 leukopenia was seen. Then systemic therapy using GEM, and hepatic arterial infusion therapy with CDDP, l-leucovorin and 5-FU were continued biweekly. Partial response (PR) was achieved six months later, and her disease status was maintained as SD. This hepatic arterial infusion chemotherapy would be safe and feasible as therapy for inoperable intrahepatic cholangiocarcinoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2006

[Alcoholic liver diseases and hepatitis virus C in Japan].

Recently incidence of alcoholic liver disease (ALD) has been increasing in Japan associated with an increase in alcoholic beverage consumption. There have been a large number of reports about the relationship between alcohol and hepatocarcinogenesis, but it remains controversial. In the present study, we addressed the recent trend in incidence of ALD including liver cirrhosis (LC), and hepatocellular carcinoma (HCC) in heavy drinkers in Japan. We carried out nation-wide survey by asking for the hospitals that are approved by the Japanese Society of Gastroenterology for recent aspects of in-patients with ALD. Except for HCC, percentage of ALD without viral hepatitis is more than 70%, which is increased when compared to the national survey carried out in 1992. In alcoholic LC patients, those who did not have viral hepatitis were 81%. However, the percentage of HCC without viral hepatitis was 34% of all of the heavy drinkers with HCC. Regarding the case in our university hospital, 138 cases (32%) of 432 patients with HCC were heavy drinkers. However, regarding in our general hospital, 15 cases of 23 patients with HCC (61%) were heavy drinkers. In conclusion, since the consumption of alcohol is increasing in Japan, the frequency and number of cases of alcoholic liver cirrhosis are increasing. Viral hepatitis infection, however, still plays an important role in hepatocarcinogenesis in heavy drinkers.

Alcohol Drinking↗
PubMed2005

Expression of Musashi-1 in the rat stomach and changes during mucosal injury and restitution.

Musashi-1 is involved in maintenance of neural stem cells. In the rat stomach, we found some cells in the luminal compartment of the mucosa that stained positively for Musashi-1. These cells were distinct from other cells of epithelial lineage, except for parietal cells, and coexpressed HES5. The Musashi-1-positive cells exfoliated after damage, while Musashi-1 expression in neck cells were upregulated, and proliferating cells diminished before reappearing and increasing in number thereafter. We conclude that a subpopulation of parietal cells acts as a source of Musashi-1, which contributes to rapid re-epithelization by restoration of stem cells and regulation of cell differentiation.

Animals↗
PubMed2005

Abnormally differentiated subsets of intestinal macrophage play a key role in Th1-dominant chronic colitis through excess production of IL-12 and IL-23 in response to bacteria.

Disorders in enteric bacteria recognition by intestinal macrophages (Mphi) are strongly correlated with the pathogenesis of chronic colitis; however the precise mechanisms remain unclear. The aim of the current study was to elucidate the roles of Mphi in intestinal inflammation by using an IL-10-deficient (IL-10-/-) mouse colitis model. GM-CSF-induced bone marrow-derived Mphi (GM-Mphi) and M-CSF-induced bone marrow-derived Mphi (M-Mphi) were generated from bone marrow CD11b+ cells. M-Mphi from IL-10-/- mice produced abnormally large amounts of IL-12 and IL-23 upon stimulation with heat-killed whole bacteria Ags, whereas M-Mphi from wild-type (WT) mice produced large amounts of IL-10 but not IL-12 or IL-23. In contrast, IL-12 production by GM-Mphi was not significantly different between WT and IL-10-/- mice. In ex vivo experiments, cytokine production ability of colonic lamina propria Mphi (CLPMphi) but not splenic Mphi from WT mice was similar to that of M-Mphi, and CLPMphi but not splenic Mphi from IL-10-/- mice also showed abnormal IL-12p70 hyperproduction upon stimulation with bacteria. Surprisingly, the abnormal IL-12p70 hyperproduction from M-Mphi from IL-10-/- mice was improved by IL-10 supplementation during the differentiation process. These results suggest that CLPMphi and M-Mphi act as anti-inflammatory Mphi and suppress excess inflammation induced by bacteria in WT mice. In IL-10-/- mice, however, such Mphi subsets differentiated into an abnormal phenotype under an IL-10-deficient environment, and bacteria recognition by abnormally differentiated subsets of intestinal Mphi may lead to Th1-dominant colitis via IL-12 and IL-23 hyperproduction. Our data provide new insights into the intestinal Mphi to gut flora relationship in the development of colitis in IL-10-/- mice.

Animals↗
PubMed2005

Colonic blood flow responses in experimental colitis: time course and underlying mechanisms.

Human inflammatory bowel diseases (IBD) are associated with significant alterations in intestinal blood flow, the direction and magnitude of which change with disease progression. The objectives of this study were to determine the time course of changes in colonic blood perfusion that occur during the development of dextran-sodium-sulfate (DSS)-induced colonic inflammation and to address the mechanisms that may underlie these changes in blood flow. Intravital microscopy was used to quantify blood flow (from measurements of vessel diameter and red blood cell velocity) in different-sized submucosal arterioles of control and inflamed colons in wild-type (WT) mice. A significant (18-30%) reduction in blood flow was noted in the smallest arterioles (<40 microm diameter) on days 4-6 of DSS colitis. The arteriolar responses to bradykinin in control and DSS-treated WT mice revealed an impaired endothelium-dependent, but not endothelium-independent, vasodilation in the inflamed colon. However, this impaired vasodilatory response to bradykinin after DSS treatment was not evident in mutant mice that overexpress Cu,Zn-superoxide dismutase. Rescue of the bradykinin-induced vasodilation during DSS colitis was also observed in mice that are genetically deficient in the NAD(P)H oxidase subunit gp91(phox). These findings indicate that the decline in blood flow during experimental colitis may result from a diminished capacity of colonic arterioles to respond to endogenous endothelium-dependent vasodilators like bradykinin and that NAD(P)H oxidase-derived superoxide plays a major role in the induction of the inflammation-induced endothelium-dependent arteriolar dysfunction.

Animals↗
PubMed2005

Expression of adhesion molecules on mature cholangiocytes in canal of Hering and bile ductules in wedge biopsy samples of primary biliary cirrhosis.

AIM: To examine the expression of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) expression on canals of Hering (CoH) and bile ductules associated with the autoimmune process of bile duct destruction in primary biliary cirrhosis (PBC). METHODS: Ten wedged liver biopsies of PBC (five cases each of stages 2 and 3) were studied. The liver specimens were processed for transmission electron microscopy. Immunohistochemistry was performed using anti-ICAM-1 and anti-LFA-1 mouse mAbs. In situ hybridization was done to examine the messenger RNA expression of ICAM-1 in formalin-fixed, paraffin-embedded sections using peptide nucleic acid probes and the catalyzed signal amplification (CSA) technique. Immunogold-silver staining for electron microscopy was performed using anti-ICAM and anti-LFA-1 mouse mAbs. The immunogold particles on epithelial cells of bile ductules and cholangiocytes of CoH cells were counted and analyzed semi-quantitatively. Western blotting was performed to confirm ICAM-1 protein expression. RESULTS: In liver tissues of PBC patients, immunohistochemistry showed aberrant ICAM-1 expression on the plasma membrane of epithelial cells lining bile ductules, and also on mature cholangiocytes but not on hepatocytes in CoH. LFA-1-positive lymphocytes were closely associated with epithelial cells in bile ductules. ICAM-1 expression at protein level was confirmed by Western blot. In situ hybridization demonstrated ICAM-1 mRNA expression in bile ductules and LFA-1 mRNA in lymphocytes infiltrating the bile ductules. By immunoelectron microscopy, ICAM-1 was demonstrated on the basal surface of epithelial cells in bile ductules and on the luminal surfaces of cholangiocytes in damaged CoH. Cells with intermediate morphology resembling progenitor cells in CoH were not labeled with ICAM-1 and LFA-1. CONCLUSION: De novo expression of ICAM-1 both on mature cholangiocytes in CoH and epithelial cells in bile ductules in PBC implies that lymphocyte-induced destruction through adhesion by ICAM-1 and binding of LFA-1-expressing activated lymphocytes takes place not only in bile ductules but also in the CoH.

Aged↗
PubMed2005

Enhanced plasma ghrelin levels in Helicobacter pylori-colonized, interleukin-1-receptor type 1-homozygous knockout (IL-1R1-/-) mice.

AIM: Ghrelin is an endogenous ligand for the growth hormone secretagogue receptor, and it plays a role in stimulating the growth hormone secretion, food intake, body weight gain and gastric motility. Eradication of Helicobacter pylori (H pylori) was shown to be associated with increase of the body weight. On the other hand, H pylori infection evokes the release of gastric IL-1beta. The present study was designed to investigate the involvement of the gastric IL-1 signal in the ghrelin dynamics in H pylori-colonized mice. METHODS: Twelve-week-old female IL-1-receptor type 1-homozygous-knockout mice (IL-1R1(-/-)) and their wild-type littermates (WT) were orally inoculated with H pylori (Hp group), while other cohorts received oral inoculation of culture medium (Cont group). Thirteen weeks after the inoculation, the mice were examined. The plasma and stomach ghrelin levels and the gastric preproghrelin mRNA were measured. RESULTS: Although the WT mice with H pylori infection showed a significantly decreased body weight as compared with that of the animals without H pylori infection, H pylori infection did not influence the body weight of the IL-1R1-knockout (IL-1R1(-/-)) mice. In the H pylori-infected IL-1R1(-/-) mice, the total and active ghrelin levels in the plasma were significantly increased, and the gastric ghrelin level was decreased. No significant differences were noted in the gastric preproghrelin mRNA expression. CONCLUSION: Ghrelin secretion triggered by H pylori infection might be suppressed by IL-1beta, the release of which is also induced by the infection, resulting in the body weight loss of mice with H pylori infection.

Animals↗