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F Ueda

Publications and source records attributed to F Ueda.

At least 19 recordsLinked to original sources
PubMed2003

Contrast-enhanced MRA for investigation of cerebral arteriovenous malformations.

We evaluated contrast-enhanced MRA (enhanced 3-D fast gradient-echo [efgre3d] with spectral inversion recovery) for identification of 15 intracranial arteriovenous malformations (AVMs) in 14 patients. Demonstration of the feeding arteries was classified as good for 16 examinations on maximum-intensity projections and multiprojection volume reconstruction images. The nidus was seen well in all patients. Definition of the draining veins was good or fair except for one poor result. Therapeutic effects were clearly demonstrated in three follow-up series. Contrast-enhanced MRA using efgre3d is useful for delineation of AVMs and for follow-up after treatment.

Adult↗
PubMed2002

Contrast-enhanced MR angiography (enhanced 3-D fast gradient echo) for diagnosis of cerebral aneurysms.

We evaluated contrast-enhanced MRA (enhanced 3-D fast gradient echo, EFGRE3D, with spectral IR) for the identification of unruptured cerebral aneurysms. We examined 22 aneurysms from 15 patients. In its ability to identify aneurysms, contrast-enhanced MRA was superior to 3-D-time of flight (3D-TOF) MRA in 4 instances, equal in 17, and inferior in 1. Contrast-enhanced MRA demonstrated thrombus formation more clearly and accurately than did 3D-TOF MRA. Contrast-enhanced MRA was performed in less than 1 min, and was found to be a useful method for the identification of intracranial aneurysms.

Aged↗
PubMed2002

Swift and definite serotyping for isolated Listeria monocytogenes strains.

The serotype is most important for molecular epidemiological analysis of Listeria monocytogenes (L.m.) contaminating marketed meats. An improvement on the traditional method was thus attempted in the present study because of the requirement of swift and definite serotyping. In the determination of O-antigen, definite judgement was allowed by an immediate cooling at 80 degrees C after autoclaving the bacteria. In the determination of H-antigen, use of a culture plate without Craigie's tube yielded the active bacteria only by single culture. The stable and clear agglutination in many samples was also obtained with a microplate using less antiserum. The availability was confirmed with 123 strains and the serovar 1/2b was dominant in the Japanese strains.

Humans↗
PubMed2000

Irsogladine upregulates expressions of connexin32 and connexin26 in the rat liver.

A gap junction is the channel for cell-to-cell communication and plays an important role in the maintenance of tissue homeostasis, control of cell growth and differentiation, and prevention of experimental hepatocarcino-genesis. Irsogladine, an antiulcer drug, augments gap junctional intercellular communication in gastric mucosa, but the effect of irsogladine on the liver remains uncertain. In this study the effects of irsogladine on the liver were investigated from the viewpoints of gap junctional protein connexin (Cx)32 and Cx26 in rats. Twelve rats were divided into a control group (n=6) and the irsogladine group (n=6) in which irsogladine (20 mg/kg per day) was administered orally for 3 days before sample collection, and the two groups were compared in regard to liver enzymes (serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH)), serum- and tissue-calcium concentrations, immunohistochemical expressions of Cx32 and Cx26, and RT-PCR analysis. In immunohistochemistry, analyzed using an image processor for analytical pathology (IPAP), the number of Cx32-positive spots was higher and the area of Cx26-positive spots were larger in the irsogladine group than those in the control group (P=0.036 and P=0.00032, respectively). In RT-PCR analysis, the mRNA of Cx32 or Cx26 in the irsogladine group showed a tendency to be higher than in the control group, but not significantly (Cx32, P=0.70; Cx26, P=0.07). Another 30 rats were used for measurements of cyclic-adenosine monophosphate (c-AMP) of the liver. c-AMP concentration was increased 1 h after the administration of irsogladine, which partially explained how the Cxs were upregulated. These findings may suggest that irsogladine upregulates Cx32 and Cx26 expressions in the liver of rats.

Journal Article↗
PubMed2000

Effect of alpha-2 adrenoceptor antagonists on colonic function in rats.

We studied the effect of alpha-2 adrenoceptor antagonists on colonic function stimulated by water-avoidance stress, 5-hydroxytryptamine (5-HT), bethanechol and castor oil by comparison with the effects of atropine and a 5-hydroxytryptamine 3 (5-HT3) receptor antagonist, ondansetron. Yohimbine, idazoxan and atropine, but not ondansetron, significantly inhibited water-avoidance stress-stimulated faecal excretion. Yohimbine and idazoxan inhibited neither 5-HT- nor bethanechol-stimulated faecal excretion. In contrast, atropine inhibited both 5-HT- and bethanechol-stimulated faecal excretion and ondansetron inhibited 5-HT-stimulated faecal excretion. Yohimbine did not inhibit the incidence of diarrhoea induced by castor oil, but idazoxan significantly inhibited diarrhoea observed during a 1-h period after the administration of castor oil. Both atropine and ondansetron inhibited diarrhoea during a 2-h period after the administration of castor oil. These findings suggest that alpha-2 adrenoceptor antagonists specifically inhibit colonic motor function stimulated by stress in rats.

Adrenergic alpha-2 Receptor Antagonists↗
PubMed2000

Importance of gap junction in gastric mucosal restitution from acid-induced injury.

Evidence is accumulating that gap junctional intercellular communication (GJIC) plays an important role in the gastric mucosal defense system. This study was conducted to determine whether GJIC mediates a restitution process in gastric mucosa. Male Sprague-Dawley rats were fasted and anesthetized. Gastric injury was induced by luminal perfusion with 0.2N HCl for 10 minutes. Mucosal integrity was continuously monitored by measuring the clearance of chromium 51-labeled ethylenediaminetetraacetic acid, which was used for analysis of recovery from the injury. Perfusion with 0.25% octanol (OCT; inhibitor of GJIC) was started after acid injury to assess its effect on restitution. The effect of irsogladine (IG; activator of GJIC) was also tested. Gastric mucosal GJIC was immunohistochemically evaluated with monoclonal antibody gap junction protein (connexin 32). Recovery from acid-induced mucosal injury occurred rapidly when acid perfusion was discontinued (within about 60 minutes). OCT, which didn't cause any injury to normal gastric mucosa, significantly inhibited the restitution. IG reversed this inhibition in a dose-dependent manner. In an immunohistochemical study, OCT-induced damage of gap junction was demonstrated, but not after IG pre-treatment. These findings suggest that GJIC may play a critical role in restitution in rat gastric mucosa and that gap junction function may be one of the important factors for the mucosal defense system.

Animals↗
PubMed2000

Relationship between vanadate induced relaxation and vanadium content in guinea pig taenia coli.

Abstract: Vanadate has been known to induce a transient increase in high K+ induced contraction, and also gradually relax the high K+ contraction itself in guinea pig taenia coli. The relationship between the rate of relaxation and ion content of Na+, K+, and V ion at the cellular level was investigated when vanadate was applied to contracted muscle. Tissue Na+ and V ion content increased linearly, depending on the time after vanadate treatment, reaching maximum levels of approximately 50 mM x kg(-1) and 0.25 mM x kg(-1) wet weight, respectively. There was a positive correlation between the V ion and Na+ contents, while there was a negative correlation between both ions and the relaxed rate of the high K+ induced contraction. The uptake of V ion was affected by the external K+ concentration, and the maximum rate of V ion uptake decreased to 40% in the presence of 90 mM external K+. These results suggest that a small amount of V ion was enough to inhibit the Na+ pump activity and muscle contraction in the high K+ solution.

Animals↗
PubMed2000

Characterization of iap gene in Listeria monocytogenes strains isolated in Japan.

Variation of the iap gene region (407bp) encoding an invasion-associated protein p60 was studied on 12 strains of Listeria monocytogenes of different origin in Japan. These 12 strains are known to have 2 types of serotype (1/2a and 4b) and have a diversity among the strains (Saito et al., 1998). The dye-primer cycle sequencing method was employed to determine the genomic structure, and the nucleotide sequences obtained were compared with those of reference strain SV 1/2a EGD. Differences found in the nucleotides were as follows; point mutations of 33 variations in 32 places; an insertion and 3 deletions of 3 bases; AAT position (po.) 1282-1283, and GCA po. 1307-1309, ACA po. 1412-1414, AAT po. 1439-1444, respectively. Different repeating numbers by 6 base unit, ACA AAT, were also found in the tandem repeat region (po. 1394-1423). Classification of 12 strains was attempted, then 8, 4 and 5 types were obtained from the point mutations, the insertions and deletions, and the repeating numbers, respectively. Consequently, 8 patterns were profiled regardless of each serotype. From these results, genomic structures were partially clarified in the iap gene 407bp of L. monocytogenes isolated in Japan. Then, the possibility of detailed epidemiology for L. monocytogenes infection using a combination of serotype and genome structure was suggested because of the previous polymorphism thought to be due to the nucleotide differences in the region.

Bacterial Proteins↗
PubMed1999

Olivary degeneration after intracranial haemorrhage or trauma: follow-up MRI.

We studied serial MRI appearances of transneuronal degeneration in the inferior olives, retrospectively analysing follow-up images of five patients, three with head injury and two with brain stem haemorrhage. We performed 13 MRI studies 4 days to 2 years 7 months after the accident. All but one of the patients exhibited bilateral olivary high signal on T2-weighted images. The interval between causal event and appearance of olivary changes was 2-4 months, images 4 days to 1.5 months after the accidents revealing no changes. Olivary enlargement was observed in four patients 2-4 months after ictus.

Adolescent↗
PubMed1999

Vanadium contamination and the relation between vanadium and other elements in wild birds.

There is little information on vanadium (V) contamination in wildlife. In the present study, the mean V contents in liver and kidney from 41 wild Japanese water birds were less than 3.69 and 8.11 microg/g dry wt, respectively. The V contents in the liver and kidney of the spotbill duck were more than two times higher than those of other species in Japan. Spotbill ducks obtained in a residential district had a strong correlation between the V contents in the kidneys and those in the livers (R=0.924), and also between V and Ti, Cd, and Li contents in the liver (R>0.8). These results suggest that V accumulation in wild birds reflects the degree of environmental contamination.

Journal Article↗
PubMed1999

In vivo anatomical analysis of arterial contact with trigeminal nerve: detection with three-dimensional spoiled grass imaging.

The purpose of this study was to review the normal in vivo neurovascular relationship between the trigeminal nerve and surrounding arteries without the use of volunteers. 290 nerves in 145 cases were reviewed during a 1-year period. Axial source images and multiplanar reconstructed (MPR) images were used to determine the neurovascular contact and direction of contact. Multiplanar volume reformation (MPVR) was used to identify the contact vessels and to demonstrate the relationship between the nerve and arteries. Vascular contact was found in 29% of the 290 nerves (83 nerves). The arteries involved were the superior cerebellar artery (SCA) or the anterior inferior cerebellar artery (AICA). Vascular contact with two arteries was found in 3%. Of the 286 asymptomatic nerves, the nerve was located between the two vessels in 3% and compression was seen in 1%. Three points of vascular contact by the two arteries were identified in one asymptomatic nerve. The direction of contact between the SCA and the nerve was superior (38%), superomedial (32%) or medial (15%) in most cases. The direction of contact between the AICA and the nerve was inferior, inferolateral or lateral in all cases. Vascular contact at the root entry zone (REZ) was noted in 90%. Four nerves were affected by trigeminal neuralgia, one of which touched an artery and two were compressed. It was concluded that arterial contact can be assessed without difficulty but evaluation of vascular compression is not easy.

Adolescent↗
PubMed1998

Irsogladine maleate inhibits angiogenesis in wild-type and plasminogen activator-deficient mice.

BACKGROUND: The activation of the zymogen plasminogen to the serine protease plasmin by urokinase-type (uPA) and tissue-type (tPA) plasminogen activators (PA) is an important event in a variety of physiologic and pathophysiologic processes in mammals. Enhanced PA activity occurs during angiogenesis and has been correlated in vitro and in vivo with increased tumor aggressiveness and is an indicator of poor prognosis in a variety of tumors in humans. Preliminary studies suggest that the antiulcer drug irsogladine maleate (IM) diminishes PA activity in vitro and may inhibit angiogenesis in vivo. To define the precise mechanism of angiogenesis inhibition by IM in vivo, we tested the ability of IM to blunt angiogenesis in a mouse cornea neovascularization model performed in wild-type and PA-knockout mice. METHODS: Three days prior to pellet implantation, groups of C57Bl/6 wild-type, uPA-deficient (upA-/-), and tPA-deficient (tPA-/-) mice received IM (300 mg/kg), IM (500 mg/kg), or vehicle (0.5% carboxymethylcellulose) via oral gavage. After 3 days of treatment, hydron polymer-coated pellets of sucrose aluminum sulfate containing 100 ng of basic fibroblast growth factor (bFGF) were inserted into surgically created pockets in the cornea of each mouse. On postoperative day 6, the neovascularization of each cornea was evaluated by a blinded observer using slit lamp microscopy and photographed. Angiogenesis was quantified by calculating vascular area (mm2) +/- SEM using a modified formula for a half ellipse that incorporates calibrated vessel measurements [Vessel length (mm) x Clock hours x pi x 0.2]. RESULTS: IM treatment (300 and 500 mg/kg/day) resulted in a dose-dependent reduction of angiogenesis in wild-type mice by 21 and 45.3% (P < 0.02, P < 0.001), in tPA-deficient mice by 42.6 and 46% (P < 0.001, P < 0.001), and in uPA-deficient mice by 27.2 and 46% (P < 0.05, p < 0.001), respectively. No quantitative differences in neovascularization were observed in either treatment group between transgenic mouse strains. No toxicity was noted in any group. CONCLUSION: IM inhibits bFGF-induced angiogenesis in wild-type, tPA-knockout, and uPA-knockout mice. The observation that IM significantly diminishes angiogenesis in both PA-deficient mice and wild-type mice suggests that the mechanism of action of IM may be independent of plasminogen activation.

Animals↗
PubMed1998

Inhibition of stress-stimulated colonic propulsion by alpha 2-adrenoceptor antagonists in rats.

Alpha2-adrenoceptor antagonists have been reported to stimulate colonic motor activity, but the effect on colonic motor dysfunction is unclear. We have investigated the effect of alpha 2-adrenoceptor antagonists on wrap-restraint stress-stimulated and normal colonic propulsion in rats. Colonic propulsion was evaluated by the transit of a charcoal marker along the colon. Faecal pellets output was also measured. A 30-min exposure to wrap-restraint stress starting 120 min after infusion of the charcoal marker significantly stimulated colonic transit with a concomitant increase in faecal pellets. Yohimbine and idazoxan, alpha 2-adrenoceptor antagonists, clonidine, an alpha 2-adrenoceptor agonist, and atropine suppressed wrap-restraint stress-stimulated colonic transit and faecal excretion in a dose-dependent manner. Ondansetron and YM060, 5-hydroxytryptamine3 (5-HT3) receptor antagonists, potently inhibited wrap-restraint stress-stimulated colonic transit, but only weakly inhibited faecal excretion. Neither alpha 2-adrenoceptor antagonists nor atropine had any significant effect on normal colonic transit, whereas clonidine and the 5-HT3 receptor antagonists inhibited it. alpha 2-Adrenoceptor antagonists as well as clonidine, atropine and 5-HT3 receptor antagonists inhibit the stress-induced colonic motor dysfunction in rats.

Adrenergic alpha-Agonists↗
PubMed1998

Suppressive effect of irsogladine maleate on diethylnitrosamine-initiated and phenobarbital-promoted hepatocarcinogenesis in male F344 rats.

Modifying effects of irsogladine maleate (IRG) on diethylnitrosamine (DEN)-induced hepatocarcinogenesis were examined in male F344 rats. Six-week-old rats were divided into 8 groups. Groups 1 through 4 were given a single i.p. injection of DEN (200 mg/kg body weight) at the start of the experiment, whereas groups 5 through 8 received a single i.p. injection of saline as the vehicle treatment. Groups 1 and 8 were kept on the basal diet and distilled water throughout the experiment (36 weeks). Groups 2 and 7 were exposed to 500 ppm phenobarbital (PB) in the drinking water, starting one week after the carcinogen or vehicle treatment. Groups 3 and 5 were fed the diet mixed with 125 ppm IRG from one week after DEN or vehicle treatment. Groups 4 and 6 were given 125 ppm IRG-containing diet and drinking water with 500 ppm PB after the carcinogen or vehicle treatment. Liver neoplasms developed in groups 1 (1/15 rats, 7%) and 2 (14/14 rats, 100%). However, no liver tumors were found in rats of groups 3 through 8. Incidence and average number of liver neoplasms in group 4 (0/14 rats, 0%) were less than those in group 2 (P < 0.0001). The number of glutathione S-transferase placental form (GST-P)-positive liver cell foci in group 3 or 4 was significantly smaller than that in the appropriate control (P < 0.01, P < 0.001, respectively). The average and unit areas of these foci in group 4 were also significantly smaller than those in group 2 (P < 0.001, P < 0.05, respectively). These results suggest that IRG could be a chemopreventive agent for rat liver carcinogenesis.

Animals↗
PubMed1998

Role of gap junctions in inhibiting ischemia-reperfusion injury of rat gastric mucosa.

Gap junctional intercellular communication (GJIC) is known to be important in the maintenance of tissue homeostasis. However, the role of GJIC in gastric mucosa has not been well investigated. We tested the hypothesis that maintenance of GJIC protects rat gastric mucosa against ischemia-reperfusion (I/R) stress by using irsogladine, an activator of GJIC, and octanol, an inhibitor of GJIC. Intragastric perfusion with octanol before ischemia resulted in a significant increase in 51Cr-EDTA clearance after reperfusion. Intraduodenal pretreatment with irsogladine attenuated the increase in 51Cr-EDTA clearance produced by octanol in a dose-dependent manner. Epithelial gap junctions reacted with anticonnexin-32 monoclonal antibodies were not changed after I/R stress alone. Intragastric perfusion with octanol caused a significant reduction in immunoreactive connexin-32 spots, which was completely reversed by irsogladine. These results indicate that inhibition of GJIC weakens the barrier function of gastric mucosa and subsequently causes damage of the barrier function in combination with I/R. Facilitation of GJIC and maintenance of gap junctions protect gastric mucosal barrier functions by potentiating cellular integrity.

Animals↗
PubMed1998

High glucose induces alteration of gap junction permeability and phosphorylation of connexin-43 in cultured aortic smooth muscle cells.

Gap junction is thought to have a crucial role in maintaining tissue homeostasis. We examined the effect of a high glucose level on gap junctional intercellular communication (GJIC) activity in cultured vascular smooth muscle cells (VSMCs) using the fluorescent dye transfer method. After a 48-h incubation with 22 mmol/l glucose (high glucose level), GJIC activity of VSMCs was significantly reduced compared with incubation with 5.5 mmol/l glucose (normal glucose level) (P < 0.05). Treatment of the cells with 12-O-tetradecanoylphorbol-13-acetate (TPA; 5 x 10(-8) mol/l), a protein kinase C (PKC) activator, for 1 h also reduced GJIC activity (P < 0.01). In addition, treatment of the cells with calphostin C, a specific PKC inhibitor, for 3 h completely restored the GJIC activity inhibited by the high glucose level. Western blot analysis showed that connexin 43 (Cx43), which is the major functional protein of gap junction, is present in multiphosphorylated forms: a nonphosphorylated form (P0) and phosphorylated forms (P1, P2, and P3). Incubation of VSMCs with a high glucose level significantly increased the density ratio of P3/P0 compared with a normal glucose level (P < 0.05). Similarly, treatment of the cells with TPA significantly increased the P3/P0 ratio compared with controls (P < 0.01). In addition, the increase in the P3/P0 density ratio induced by a high glucose level was restored to the control level by both staurosporine and calphostin C. These results suggest that the high glucose level induced the inhibition of GJIC activity in cultured VSMCs through excessive phosphorylation of Cx43, mediated by PKC activation. This may contribute to the development of the macroangiopathy associated with diabetes.

Animals↗
PubMed1998

Classification of Listeria monocytogenes by PCR-restriction enzyme analysis in the two genes of hlyA and iap.

PCR-restriction enzyme analysis in the two virulence-associated genes was performed. The hlyA gene cording for listeriolysin O and the iap gene cording for an invasion associated factor were amplified with primers SH2 or SI3. The PCR products obtained were cleaved with 32 restriction enzymes, and restriction profiles from 12 strains, 6 each of serotypes 1/2a and 4b, were compared. We obtained two profiles for the hlyA using 4 restriction enzymes and eight profiles for the iap by using AluI, and the results of the profiles did not correlate with the serotypes. The polymorphism in the iap region was of a higher degree than that in the hlyA region, and the PCR-restriction enzyme analysis of the iap gene with primers SI3 and AluI was confirmed as one of the useful epidemiological analysis methods for listerosis outbreaks.

Bacterial Proteins↗