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M Fujita

Publications and source records attributed to M Fujita.

At least 91 records · Page 5Linked to original sources
PubMed2001

Up-regulation of the ectodermal-neural cortex 1 (ENC1) gene, a downstream target of the beta-catenin/T-cell factor complex, in colorectal carcinomas.

To clarify the molecular mechanisms of human carcinogenesis associated with abnormal Wnt/wingless signaling, we searched for genes the expression of which was significantly altered by introduction of wild-type AXIN1 into LoVo colon cancer cells. By means of a cDNA microarray, we compared expression profiles of LoVo cells infected with either adenoviruses expressing wild-type AXIN1 (Ad-Axin) or those expressing a control gene (Ad-LacZ). Among the genes showing altered expression, the ectodermal-neural cortex 1 (ENC1) gene was down-regulated in response to Ad-Axin. The promoter activity of ENC1 was elevated approximately 3-fold by transfection of an activated form of beta-catenin together with wild-type T-cell factor (Tcf)4 in HeLa cells. Semiquantitative reverse transcription-PCR experiments revealed that expression of ENC1 was increased in more than two-thirds of 24 primary colon cancer tissues that we examined compared with corresponding noncancerous mucosae. Introduction of exogenous ENC1 increased the growth rate of HCT116 colon cancer cells in serum-depleted medium. In other experiments, overexpression of ENC1 in HT-29 colon cancer cells suppressed the usual increase of two differentiation markers, in response to treatment with sodium butyrate, a differentiation-inducible agent. These data suggest that ENC1 is regulated by the beta-catenin/Tcf pathway and that its altered expression may contribute to colorectal carcinogenesis by suppressing differentiation of colonic cells.

Axin Protein↗
PubMed2001

Cavity-directed synthesis of labile silanol oligomers within self-assembled coordination cages.

This paper introduces a concept that is referred to as cavity-directed synthesis by showing the selective oligomerization of trialkoxysilanes, RSi(OMe)3 (7), in self-assembled hollow compounds. Pd(II)-linked coordination hosts (cage, bowl, or tube) are found to strictly control the oligomerization of 7 (R = 2-naphthyl) in such a way that their optimal guests are produced in their cavities. Thus, within coordination tube 1, one molecule of 7 is accommodated and subsequently hydrolyzed to give silanetriol RSi(OH)3 (4). Under ordinary aqueous conditions, this reactive compound undergoes rapid polycondensation (so-called sol-gel condensation) leading to Si-O networks. Within the cavity of 1, however, 4 remains very stable and the polycondensation is completely suppressed. On the other hand, coordination bowl 2 and cage 3 give its dimers RSi(OH)2OSi(OH)2R (5) and cyclic trimers [RSi(OH)O]3 (6), respectively. X-ray crystallographic studies clearly show that the cavity size and the shape of 1, 2, and 3 nicely fit with those of 4, 5, and 6, respectively, demonstrating that the cavities strictly direct the oligomerizaion reaction of 7.

Journal Article↗
PubMed2001

DOSY study on dynamic catenation: self-assembly of a [3]catenane as a meta-stable compound from twelve simple components.

Synthesis of [2]catenane 6 has been successfully achieved by the combination of Pd complex 1 and pyridines 2 and 3 at a molar ratio of 2:1:1 in D20. A mixture of square molecule 4 (prepared from 1 and 2) and macrocycle 5 (obtained from 1 and 3), in which the final ratio of 1, 2, and 3 was kept 2:1:1 reorganizes in D2O/CD3OD (1:1) to form 6 within one day. However, the same mixture in D2O shows the formation of novel [3]catenane 7 along with the [2]catenane. In order to make 7, the theoretical ratio of components 1, 2, and 3 should be 3:1:2. Thus, deliberately maintaining such ratio of the above-mentioned molecules, a higher proportion of the [3]catenane is observed in D2O as found from 1H NMR spectra of the system. Reorganization of the twelve components to form [3]catenane is supported by studies with the DOSY method. This method is a first attempt to separate, from a mixture, either catenanes or any other supramolecular self-assembly structures. CSI-MS studies further support the assigned catenane super structures 6 and 7. All the results indicate that the [2]catenane is thermodynamically the most stable structure, while the [3]catenane is a meta-stable self-assembly.

DNA↗
PubMed2001

The trimannosyl cores of N-glycans are important for the procoagulant protease-inhibitory activity of urinary protein C inhibitor.

We investigated the relationship between the procoagulant protease-inhibitory activity and the N-glycan structures in urinary protein C inhibitor (uPCI) by sequential exoglycosidase digestions based on the N-glycan structures elucidated in this report. uPCI was glycosylated on the three potential N-glycosylation sites, asparagines 230, 243 and 319 (N230, N243 and N319) in the molecule and had four biantennary complex type sugar chains. The inhibitory activities of uPCI toward thrombin and plasma kallikrein were little changed by the sequential removal of N-acetylneuraminic acid and galactose residues from the termini and N-acetylglucosamine residues from the branches of the N-glycans. However, the inhibitory activities were markedly decreased by further removing alpha-mannose residues from the trimannosyl cores of the N-glycans. These results suggest that the trimannosyl cores of N-glycans are important for uPCI to inhibit the procoagulant protease.

Amino Acid Sequence↗
PubMed2001

Gelatin sheet incorporating basic fibroblast growth factor enhances healing of devascularized sternum in diabetic rats.

BACKGROUND: Poor healing of the sternum often limits the use of bilateral internal thoracic arteries (BITAs) after coronary bypass surgery in diabetic patients. We have reported that a gelatin sheet that incorporates basic fibroblast growth factor (bFGF) accelerates sternal healing after BITA removal in normal rats. This study evaluated the effects of the above method for sternal healing in diabetic animals. METHODS AND RESULTS: Diabetic Wistar rats with blood glucose levels >400 mg/dL and body-weight loss >20 g were established by a single intravenous injection of streptozotocin (55 mg/kg). After median sternotomy and BITA removal, 16 diabetic rats received either a gelatin sheet that incorporated bFGF (100 microg/sheet) on the posterior table of the sternum (FGF group, n=9) or no gelatin sheet (control, n=7). Peristernal blood flow, as measured by a noncontact laser Doppler 4 weeks after surgery in the FGF group, recovered to the preoperative level (106+/-10% versus 82+/-9%, P<0.01), and marked angiogenesis was also observed around the sternum in the FGF group (30.5+/-3.2 versus 15.8+/-2.7 vessels/unit area, P<0.01). Deep sternal wound complications developed in 5 control rats but only in 1 rat in the FGF group (P<0.05). In the FGF group, histological examination showed improved sternal healing (excellent in 6 rats and slow/poor healing in 3). Bone mineral content as assessed by dual-energy x-ray absorptometry was greater in the FGF group (75.9+/-18.1 versus 48.9+/-10.7 mg, P<0.05). Bone mineral density of the sternum was similar between the 2 groups. CONCLUSIONS: A gelatin sheet that incorporates bFGF may offset sternal ischemia and accelerate sternal bone regeneration and healing, even in diabetic patients.

Administration, Topical↗
PubMed2001

Sex differences in [123I]beta-CIT SPECT measures of dopamine and serotonin transporter availability in healthy smokers and nonsmokers.

Nicotine and other constituents of tobacco smoke elevate dopamine (DA) and serotonin (5-HT) levels in brain and may cause homeostatic adaptations in DA and 5-HT transporters. Since sex steroids alter DA and 5-HT transporter expression, the effects of smoking on DA and 5-HT transporter availability may differ between sexes. In the present study, DA and 5-HT transporter availabilities were quantitated using single photon emission computed tomography (SPECT) imaging approximately 22 h after bolus administration of [123I]beta-CIT, an analog of cocaine which labels DA and 5-HT transporters. Forty-two subjects including 21 pairs of age-, race-, and gender-matched healthy smokers and nonsmokers (12 female and 9 male pairs) were imaged. Regional uptake was assessed by the outcome measures, V3", which is the ratio of specific (i.e., ROI-cerebellar activity) to nondisplaceable (cerebellar) activity, and V3, the ratio of specific to free plasma parent. Overall, striatal and diencephalic [123I]beta-CIT uptake was not altered by smoking, whereas brainstem [123I]beta-CIT uptake was modestly higher (10%) in smokers vs. nonsmokers. When subgrouped by sex, regardless of smoking status, [123I]beta-CIT uptake was higher in the striatum (10%), diencephalon (15%), and brainstem (15%) in females vs. males. The sex*smoking interaction was not significant in the striatum, diencephalon, or brainstem, despite the observation of 20% higher brainstem [123I]beta-CIT uptake in male smokers vs. nonsmokers and less than a 5% difference between female smokers and nonsmokers. The results demonstrate higher DA and 5-HT transporter availability in females vs. males and no overall effect of smoking with the exception of a modest elevation in brainstem 5-HT transporters in male smokers. Although these findings are preliminary and need validation with a more selective 5-HT transporter radiotracer, the results suggest that brainstem 5-HT transporters may be regulated by smoking in a sex-specific manner.

Adult↗
PubMed2001

A novel disaccharide substrate having 1,2-oxazoline moiety for detection of transglycosylating activity of endoglycosidases.

A disaccharide substrate of Manbeta1-4GlcNAc-oxazoline 2 was designed and synthesized as a novel probe for detection of the transglycosylating activity of endoglycosidases. A regio- and stereoselective transglycosylation reaction of 2 to GlcNAcbeta1-O-pNP or Dns-Asn(GlcNAc)-OH catalyzed by endo-beta-N-acetylglucosaminidase from Mucor hiemalis (Endo-M) and endo-beta-N-acetylglucosaminidase from Arthrobacter protophormiae (Endo-A) has been demonstrated for the first time, resulting in the core trisaccharide derivative Manbeta1-4GlcNAcbeta1-4GlcNAcbeta1-O-pNP 8 (or -(Dns)Asn-OH). Interestingly, the transglycosylation proceeds irreversibly; the resulting trisaccharide 8 was not hydrolyzed by Endo-M and Endo-A. Based on these results, a new mechanism including an oxazolinium ion intermediate has been proposed for the endoglycosidase-catalyzed hydrolysis or transglycosylation.

Carbohydrate Sequence↗
PubMed2001

Identification of AF17 as a downstream gene of the beta-catenin/T-cell factor pathway and its involvement in colorectal carcinogenesis.

To elucidate the molecular mechanism of colorectal carcinogenesis, we have been attempting to isolate genes involved in the beta-catenin/T-cell factor pathway. In the experiments reported here, analysis by cDNA microarray indicated that AF17, a fusion partner of the MLL gene in acute leukemias with t(11;17)(q23;q21), was transactivated according to accumulation of beta-catenin. Expression of AF17 was significantly enhanced in 8 of the 12 colorectal cancer tissues examined. Introduction of a plasmid designed to express AF17 stimulated growth of NIH3T3 cells, and fluorescence-activated cell sorter analysis indicated that the AF17 regulation of cell-cycle progression was occurring mainly at the G(2)-M transition. Our results suggest that the AF17 gene product is likely to be involved in the beta-catenin-T-cell factor/lymphoid enhancer factor signaling pathway and to function as a growth-promoting, oncogenic protein. These findings should aid development of new strategies for diagnosis, treatment, and prevention of colon cancers and acute leukemias by clarifying the pathogenesis of these conditions.

3T3 Cells↗
PubMed2001

Impaired FHIT expression characterizes serous ovarian carcinoma.

The FHIT (fragile histidine triad) gene on chromosome 3p14.2 is a candidate tumour suppressor gene. To define the role of the FHIT gene in the development of ovarian cancer, we have examined 33 ovarian carcinomas, 2 borderline tumours and 10 benign adenomas for the presence of FHIT gene alterations. FHIT transcripts were analysed by RT-PCR and sequencing. Aberrant FHIT transcripts were observed in 5/33 carcinomas (15%) and in 1 of 2 borderline tumours. Loss of normal FHIT transcript was observed in 5/33 carcinomas (15%) but not in 2 borderline tumours or 10 benign adenomas. Allelic losses at D3S1300 and D3S4103, both located within intron 5 of FHIT, were detected in 5/24 (21%) and 5/25 (20%) informative ovarian carcinomas, respectively. Expression of Fhit protein was analysed by immunohistochemistry in 44 carcinomas, 19 borderline tumours and 16 benign adenomas. Loss or significantly reduced expression of Fhit protein was observed in 6/44 (14%) ovarian carcinomas but not in any of 19 borderline tumours or 16 benign adenomas. The impaired Fhit protein expression was significantly correlated with the loss of normal FHIT transcription. Most notably, loss of normal FHIT transcript and impaired expression of Fhit protein occurred only in serous adenocarcinomas of grade 2 and 3 (5/15; 33% and 6/19; 32%, respectively). The present data suggest that inactivation of the FHIT gene by loss of expression is one of the important molecular events associated with the genesis of ovarian carcinoma, especially of high-grade serous carcinoma.

Acid Anhydride Hydrolases↗
PubMed2001

Production of a recombinant hybrid molecule of cholera toxin-B-subunit and proteolipid-protein-peptide for the treatment of experimental encephalomyelitis.

Mucosal administration of experimental autoimmune encephalomyelitis (EAE)-specific autoantigens can reduce the onset of disease. To examine whether cholera toxin-B-subunit (CTB)-conjugated EAE-specific T-cell epitope can reduce development of the autoimmune disease in mice, we produced a recombinant hybrid molecule of CTB fusion protein linked with proteolipid-protein (PLP)-peptide139-151(C140S) at levels up to 0.1 gram per liter culture media in Bacillus brevis as a secretion-expression system. Amino acid sequencing and GM1-receptor binding assay showed that this expression system produced a uniformed recombinant hybrid protein. EAE was induced in SJL/J mice by systemic administration with the PLP-peptide. When nasally immunized 5 times with 70 microg rCTB PLP-peptide hybrid protein, mice showed a significantly suppressed development of ongoing EAE and an inhibition of both the PLP-peptide-specific delayed-type hypersensitivity (DTH) responses and leukocyte infiltration into the spinal cord. In contrast, all mice given the PLP-peptide alone or the PLP-peptide with the free form of CTB did not suppress the development of EAE and DTH responses. These results suggest that nasal treatment with the recombinant B. brevis-derived hybrid protein of CTB and autoantigen peptide could prove useful in the control of multiple sclerosis.

Administration, Intranasal↗
PubMed2001

Effects of posture on cardiac autonomic nervous activity in patients with congestive heart failure.

OBJECTIVES: We aimed to clarify which recumbent position is preferred by patients with congestive heart failure (CHF) and to evaluate whether cardiac autonomic nervous activity is different among three recumbent positions (supine, left lateral decubitus, right lateral decubitus) in patients with CHF. BACKGROUND: It remains unclear whether cardiac autonomic nervous activity is different among three recumbent positions in patients with CHF. METHODS: We studied 17 male CHF patients (66+/-7 years) and 17 age- and gender-matched healthy subjects (66+/-7 years). Each subject underwent 24-h ambulatory electrocardiographic monitoring. A channel was used to record the CM5 lead, and another to record the signal of the patient's posture with use of a newly developed small-sized detector (3.2 cm x 3.2 cm). By using spectral analysis of heart rate variability, frequency-domain measures were calculated and compared among the three recumbent positions. Normalized high-frequency (HF: 0.15 to 0.40 Hz) power was used as an index of vagal activity and the low frequency (0.04 to 0.15 Hz)/HF power ratio was used as an index of sympathovagal balance. RESULTS: In patients with CHF, the time for the right lateral decubitus position was two-fold longer than that for the supine and left lateral decubitus positions. The increased cardiac sympathetic activity and decreased vagal tone in CHF patients were normalized in the right lateral decubitus position. CONCLUSIONS: The right lateral decubitus position in patients with CHF may be a self-protecting mechanism of attenuating the imbalance of cardiac autonomic nervous activity.

Aged↗
PubMed2001

Characterization of encapsulating supramolecules by using CSI-MS with ionization-promoting reagents.

Guanidine nitrate, DMF, DMA, and DMSO are proven to be efficient ionization-promoting reagents in coldspray ionization mass spectrometry (CSI-MS) for the self-assembled cage Pt compound 1 in aqueous solution. These reagents made it possible to characterize the structures of encapsulated guest molecules in the cage. Detailed structure determinations of the cage compound encapsulating various kinds of guest molecules by using positive CSI-MS with ionization-promoting reagents are described.

Journal Article↗
PubMed2001

Alterations in the expression of the AQP family in cultured rat astrocytes during hypoxia and reoxygenation.

Aquaporins (AQPs) are a family of water-selective transporting proteins with homology to the major intrinsic protein (MIP) of lens [Cell 39 (1984) 49], that increase plasma membrane water permeability in secretory and absorptive cells. In the central nervous system (CNS), we detected the transcripts of AQP3, 5 and 8 in addition to the previously reported transcripts of AQP4 and 9 in astrocytes, of AQP3, 5 and 8 in neurons, of AQP8 in oligodendrocytes, and none of them in microglia using RNase protection assay and the reverse transcription-polymerase chain reaction (RT-PCR). Hypoxia evoked a marked decrease in the expression levels of AQP4, 5 and 9, but not of AQP3 and 8 mRNAs, and in astrocytes in vitro subsequent reoxygenation elicited the restoration of the expression of AQP4 and 9 to their basal levels. Interestingly, AQP5 showed a transient up-regulation (about 3-fold) and subsequent down-regulation of its expression within 20 h of reoxygenation after hypoxia. The changes in the profiles of AQP expression during hypoxia and reoxygenation were also observed by Western blot analysis. These results suggest that AQP5 may be one of the candidates for inducing the intracranial edema in the CNS after ischemia injury.

Animals↗
PubMed2001

Protective effect of agiotensin II type I receptor antagonist, CV-11974, on ischemia and reperfusion injury of the liver.

BACKGROUND: Microcirculatory disturbance has been shown to play a critical role in hepatic ischemia and reperfusion (I/R) injury. Angiotensin II (AngII) is one of the most potent endogenous vasoconstrictors. Angiotensin II type I (AT1) receptor antagonist has been reported to have protective effects on I/R injury of the heart and kidney. However, effect on hepatic I/R injury has not been determined. In this study, we investigate our hypothesis that AT1 receptor antagonist, CV-11974, attenuates hepatic I/R injury. METHODS: Twelve beagle dogs underwent a 2-hr total hepatic vascular exclusion with veno-venous bypass. CV-11974 was given to animals at a dose of 0.002 mg/ kg/min for 5 min followed by 0.001 mg/kg/min for 25 min via portal vein before ischemia (group II, n=6). Nontreated animals were used as the control (group I, n=6). Animal survival, hemodynamics, hepatic tissue blood flow (HTBF), liver function, platelet count, renin activity, and AngII concentration of hepatic vein, energy metabolism, and histopathology were analyzed. RESULTS: Two-week survival was 33% in group I, in contrast, 100% in group II. Mean arterial blood pressure during early reperfusion was maintained, and HTBF after reperfusion was significantly higher in group II. Treatment attenuated liver enzyme release and decrease of platelet count, increased renin and AngII, suppressed ATP degradation during ischemia and enhanced ATP resynthesis after reperfusion. Neutrophil infiltration and histopathological damages were lessened in group II. CONCLUSIONS: Our data demonstrated that the local renin-angiotensin system might play a role in hepatic microcirculation. AT1 receptor blockade with CV-11974 attenuated hepatic microcirculatory disturbance and ameliorated I/R injury.

Angiotensin II↗
PubMed2001

Attenuation of ischemia and reperfusion injury of canine livers by inhibition of type II phospholipase A2 with LY329722.

BACKGROUND: Membrane phospholipid breakdown, caused by ischemia and reperfusion (I/R) of the liver, releases free fatty acids including arachidonic acids and lysophospholipids, which serve as precursors of various inflammatory lipid derivatives. Phospholipase A2 (PLA2) is a key enzyme that initiates this reaction. In this study, we tested our hypothesis that a type II PLA2 inhibitor, LY329722, could attenuate hepatic I/R injury caused by a 2-hr total hepatic vascular exclusion (THVE) in dogs. METHODS: Eighteen beagle dogs, subjected to a 2-hr THVE, were divided into three groups. Group 1 (n=6) was untreated and served as a control group. LY329722 was administered to animals in group 2 (n=6) intravenously (0.2 mg x kg(-1) x hr(-1)) for 60 min before ischemia, and to animals in group 3 (n=6) for 60 min starting 15 min before reperfusion (0.2 mg x kg(-1) x hr(-1)). Animal survival, systemic and splanchnic hemodynamics, hepatic tissue blood flow, liver functions, energy metabolism, hepatic venous thromboxane B2 and endothelin-1 levels, phospholipid levels and tumor necrosis factor-a mRNA expression in liver tissue, and histopathologic findings were evaluated. RESULTS: Two-week animal survival was 33% (two of six) in group 1, and 100% (six of six) in groups 2 and 3. LY329722 improved systemic and splanchnic hemodynamics, hepatic tissue blood flow, and energy metabolism, reduced liver enzyme, thromboxane B2, and endothelin-1 release, prevented hepatic phospholipid degradation and tumor necrosis factor-alpha mRNA expression, and lessened histopathologic damage and the number of neutrophil infiltrating into the liver tissue. CONCLUSION: The present study demonstrated that a type II PLA2 inhibitor, LY329722, attenuated hepatic I/R injury caused by a 2-hr THVE model in dogs.

Acetates↗