Search PubMed⌕ Search

Biomedical subjects

Hiroshi Fujita

Publications and source records attributed to Hiroshi Fujita.

At least 19 recordsLinked to original sources
PubMed2007

The relationship between Helicobacter pylori infection and promoter polymorphism of the Nrf2 gene in chronic gastritis.

The transcription factor Nrf2 regulates the expression of detoxifying and antioxidant genes. Three polymorphisms of the Nrf2 gene have been reported. We attempted to clarify the relationship between Nrf2 gene polymorphism and chronic gastritis in a Japanese population. The study was performed in 159 patients with no evidence of gastric malignancy on upper gastrointestinal endoscopy (mean age, 62.03 years; male:female ratio, 102:57; peptic ulcer diseases in 69 patients, and Helicobacter pylori (H. pylori) positivity in 73.0%). We employed the PCR-SSCP method to detect gene polymorphisms using DNA extracted from peripheral blood cells or from antral biopsy specimens obtained by endoscopy. The severity of the histological chronic gastritis in antral biopsy specimens was classified according to the updated Sydney system. Although the frequencies of the SNP(-686) and SNP(-650) A alleles were decreased in subjects with peptic ulcers or severe mucosal atrophy, no significant differences were seen. However, the number of -686 G alleles was correlated with both neutrophil activity and mononuclear cell infiltration (p=0.036 and p=0.010, respectively), while the -650 C/C genotype was an independent risk factor for mononuclear cell infiltration (p=0.021 by ANOVA). In addition, both the number of -686 G alleles and the -650 C/C genotype showed an interaction with H. pylori infection to promote the infiltration of mononuclear cells (p=0.037 by ANCOVA and p=0.041 by ANOVA, respectively). Nrf2 promoter polymorphisms are significantly associated with the development of gastric mucosal inflammation, either independently or by interacting with H. pylori infection.

Chronic Disease↗
PubMed2006

Association of coronary plaque composition and arterial remodelling: a virtual histology analysis by intravascular ultrasound.

BACKGROUND: Conflicting data have been reported about the correlation between plaque composition assessed by virtual histology (VH) and remodelling index (RI). AIM: To evaluate, in a larger patient population, the relationship between plaque morphology obtained by VH and arterial remodelling. METHODS AND RESULTS: VH intravascular ultrasound was performed on 95 non-bifurcation native significant lesions (>75% stenosis) in 85 patients. Positive remodelling (defined as RI > or =1.05) was present in 28 lesions, whereas intermediate/negative remodelling (RI <1.05) was present in 67 lesions. Compared with intermediate/negative remodelling, positive remodelling was associated with an increased frequency of patients with acute coronary syndrome (n = 13 (52%) vs n = 15 (25%); p = 0.017), and with a greater plaque burden (mean (SD) 78.3 (6.3)% vs 73.2 (6.8)%, p = 0.001). At the minimal lumen site, necrotic core was significantly smaller in lesions with positive remodelling (median (interquartile range) 5.0% (2.2-11.0%)) than in lesions with intermediate/negative remodelling (median (interquartile range) 9.0% (4.0-16.0%); p = 0.048). No differences were observed in the rate of thin-cap fibroatheroma or in the presence of multiple necrotic core layers, and there were no statistical differences for fibrous, fibro fatty and dense calcium percent plaque area at the minimum lumen diameter (MLD), or for the entire lesion length between both groups. CONCLUSIONS: In vivo VH analysis shows that lesions with positive remodelling have statistically less necrotic core percent area at the MLD site compared with intermediate/negative remodelling lesions.

Aged↗
PubMed2006

Coronary plaque composition of culprit/target lesions according to the clinical presentation: a virtual histology intravascular ultrasound analysis.

AIMS: To evaluate the plaque composition obtained by virtual histology (VH) IVUS according to the clinical presentation and to compare those data to previously published histopathology data. METHODS AND RESULTS: VH was performed on 95 de novo significant lesions (>75% stenosis) in 85 patients [28 acute coronary syndrome (ACS) patients, 30 lesions; 57 stable angina pectoris (SAP) patients, 65 lesions]. There were a higher prevalence of positive remodelling (47 vs. 22%, P=0.013), thrombus (20 vs. 1.5%, P=0.0037), and echo-lucent area (23.3 vs. 7.7%, P=0.047) in ACS patients. At the minimal lumen site, fibrous plaque area was significantly larger in ACS lesions than in SAP lesions (66.0+/-10.7 vs. 61.4+/-8.9%, P=0.034), whereas necrotic core and dense calcium plaque area were smaller in ACS lesions (Necrotic core: 6.8+/-6.0 vs. 11.0+/-8.3%, P=0.02; Dense calcium: 2.6+/-3.0 vs. 4.9+/-5.8%, P=0.03). No differences in rate of thin cap fibroatheroma, thick fibrotheroma, or for the presence of multiple necrotic core layers were observed between both groups. CONCLUSION: Plaque composition obtained by VH-IVUS shows less necrotic core and more fibrous tissue in ACS compared to SAP lesions, which is in contradiction with previously published histopathologic data.

Calcinosis↗
PubMed2006

HILIC mode separation of polar compounds by monolithic silica capillary columns coated with polyacrylamide.

HILIC mode columns were prepared by an on-column polymerization of acrylamide on a monolithic silica capillary column modified with N-(3-trimethoxysilylpropyl)methacrylamide as the anchor group. The products showed HILIC mode retention characteristics with three times greater permeability and slightly higher column efficiency compared to a commercially available amide-type HILIC column packed with 5-mum particles. The selectivity of the monolithic silica-based column was similar to that of the particulate column for each group of solutes towards nucleosides, nucleic bases and carbohydrate derivatives, although a considerable difference was observed in the selectivity for the solute groups. Although the retention of solutes based on the polar functionality was much smaller with the monolithic silica columns, which had a smaller phase ratio, than with the particle-packed column, the former can achieve better separation utilizing the high permeability and higher column efficiencies of a longer column.

Journal Article↗
PubMed2006

Automatic segmentation and recognition of anatomical lung structures from high-resolution chest CT images.

This paper describes a fully automated segmentation and recognition scheme, which is designed to recognize lung anatomical structures in the human chest by segmenting the different chest internal organ and tissue regions sequentially from high-resolution chest CT images. A sequential region-splitting process is used to segment lungs, airway of bronchus, lung lobes and fissures based on the anatomical structures and statistical intensity distributions in CT images. The performance of our scheme is evaluated by segmenting lung structures from high-resolution multi-slice chest CT images from 44 patients; the validity of our method was proved by preliminary experimental results.

Humans↗
PubMed2006

[Performance evaluation of computed tomography with equivalent resolution images].

A method of evaluating the performance of computed tomography (CT) with equivalent resolution images was investigated. Generally, in performance evaluations of CT, the resolution property is measured by the wire method, and the noise property is measured from noise images of a cylindrical water phantom. The signal-to-noise ratio (SNR) is then calculated for the integrated evaluation. Our proposed method enabled perceptual integrated evaluation by using equivalent resolution images created with frequency processing. The frequency-processing factor was calculated from the ratio of the modulation transfer factors of two models of CT, and the image of one of the two was processed by the factor. Because these processed images have resolution equivalent to images of the other CT, the perceptual evaluation with noise images becomes effective. In this investigation, images of a water phantom and a middle contrast resolution phantom were employed. Perceptual comparison of the amount of noise with equivalent resolution images could be performed easily, and effective performance evaluation was achieved. Therefore, our proposed method is useful for noise property and performance evaluation of CT.

Evaluation Studies as Topic↗
PubMed2006

Is omeprazole or misoprostol superior for improving indomethacin-induced delayed maturation of granulation tissue in rat gastric ulcers?

BACKGROUND AND AIMS: Proton pump inhibitors (PPI) and prostaglandin (PG) preparations are believed to both prevent NSAID-induced gastric ulcers and promote the delayed healing of gastric ulcers by NSAIDs, but it remains unclear which of these drugs is superior. The aim of this study was to clarify which achieved better healing of NSAID-induced gastric ulcers, not only with respect to epithelialization but also repair of the submucosal tissues. METHODS: We used acetic acid to induce gastric ulcers in rats, and compared the changes between a control group, NSAID group, NSAID + PPI group and NSAID + PG group. After removing the stomach of each animal, an ulcer index was calculated and the collagen content and type III collagen content of granulation tissue were measured. We also studied fibroblast dynamics, including proliferation, collagen synthesis, differentiation into myofibroblasts, and apoptosis. RESULTS: Indomethacin prevented re-epithelialization of the ulcers, interfered with fibroblast function, and also delayed the replacement of type III collagen. Omeprazole promoted epithelialization, but could not fully reverse the influence of indomethacin on granulation tissue maturation. A concomitant dose with misoprostolreversed it completely. CONCLUSIONS: From our point of view in this study in the use of experimental ulcers, it was thought that compensation of PG should have priority to gastric acid inhibition in terms of healing of NSAID-induced gastric ulcer.

Analysis of Variance↗
PubMed2006

Assessment of vulnerable plaques causing acute coronary syndrome using integrated backscatter intravascular ultrasound.

OBJECTIVES: This study aims to define tissue characteristics of vulnerable plaques before acute coronary syndrome (ACS) by use of integrated backscatter intravascular ultrasound (IB-IVUS). BACKGROUND: Tissue characterization of coronary plaques is possible with the use of IB-IVUS. METHODS: The subjects were 140 patients with angina pectoris, and we selected 160 coronary lesions without significant stenosis for evaluation. Ultrasound signals were obtained by an IVUS system using a 40-MHz catheter. RESULTS: At the follow-up (30 +/- 7 months), 12 plaques caused ACS after the initial IVUS examination. Ten of the 12 plaques had IVUS parameters recorded at baseline. These 10 plaques were classified as vulnerable plaques (VP), and the other plaques were classified as stable plaques (SP; n = 143). There was no significant difference of vessel area, lumen area, and plaque area between VP and SP. However, plaque burden (60 +/- 9% vs. 52 +/- 9%; p = 0.014), eccentricity (0.70 +/- 0.10 vs. 0.55 +/- 0.17; p = 0.013), remodeling index (1.30 +/- 0.08 vs. 1.16 +/- 0.16; p = 0.006) and percentage lipid area (72 +/- 10% vs. 50 +/- 16%; p < 0.0001) were greater in VP than in SP. Percentage fibrous area (23 +/- 6% vs. 47 +/- 14%; p < 0.0001) was smaller in VP than in SP. The sensitivities, specificities, and positive predictive values of percentage fibrous area (90%, 96%, and 69%, respectively) and percentage lipid area (80%, 90%, and 42%, respectively) for classifying VP were evaluated. CONCLUSIONS: Tissue characteristics of VP before ACS were different from those of SP. This suggests that VP and SP as classified by IB-IVUS are useful in predicting ACS.

Aged↗
PubMed2006

Association of the circulating adiponectin concentration with coronary in-stent restenosis in haemodialysis patients.

BACKGROUND: Success of coronary stenting is limited by in-stent restenosis. We aimed to determine whether circulating levels of the cytokines, which have anti-inflammatory properties such as adiponectin or interleukin-10, could be associated with the occurrence of coronary in-stent restenosis in patients with end-stage renal disease (ESRD). METHODS: We enrolled 71 consecutive ESRD patients undergoing haemodialysis (mean age: 64.9+/-8.9 years; 19 women, 52 men; mean haemodialysis duration: 78.2+/-87.5 months), who received stenting for a single coronary lesion. Plasma concentrations of adiponectin and IL-10 were measured within one week before coronary stenting. RESULTS: Of the 71 patients who had received stenting, in-stent restenosis occurred in 37 patients (52.1%) within 6 months after stenting. In univariate logistic analysis, the homeostasis model assessment index of insulin resistance, blood haemoglobin, serum concentrations of high density lipoprotein-cholesterol or triglycerides and plasma concentrations of insulin or adiponectin were significantly associated with coronary in-stent restenosis. In a multiple logistic regression analysis among these variables, however, only the plasma adiponectin concentration was associated with the coronary in-stent restenosis: the odds ratio of the increase in 1 microg/ml of plasma adiponectin concentration for having restenosis was 0.651 (P = 0.001, 95% confidence interval: 0.506-0.839). Patients with restenosis had lower plasma adiponectin concentrations than those without [6.2+/-2.2 microg/ml (2.1-10.4 microg/ml; n = 37) vs 27.2+/-10.8 microg/ml (17.9-79.8 microg/ml; n = 34); P = 0.0001]. CONCLUSIONS: Circulating adiponectin concentrations may be associated with the occurrence of coronary in-stent restenosis in ESRD patients undergoing maintenance haemodialysis.

Adiponectin↗
PubMed2006

Measuring mouse sperm parameters using a particle counter and sperm quality analyzer: a simple and inexpensive method.

This study examined a method for analyzing the count, motility, and morphology of mouse epididymal sperm, optimizing the diluent, incubation time, sample concentration, and temperature, using a particle counter (CDA-500) to count and size sperm and a sperm quality analyzer (SQA-IIC) to measure sperm motility, quantified as the sperm motility index (SMI). The optimal conditions consisted of a 30-min incubation in D-MEM (Dulbecco's modified Eagle's medium; considering cost and availability) at 37 degrees C, with 5 x 10(6)cells mL(-1) in the original solution. Furthermore, the influence of formalin fixation, and the correlation between the automated counter and a manual method were investigated. The sample fixation had no marked effect on the sperm count or morphology assessment. A linear correlation was observed between the manual and automated methods (y=0.920x +0.276; r(2)=0.571; p<0.001; range: (3-6) x 10(6)). The suitability of the proposed method was confirmed using spermatozoa prepared from mice treated with the reproductive toxin diethylstilbestrol (DES). Using sperm from the cauda epididymidis on one side per mouse, we confirmed that measurement of these sperm parameters using the two devices was simple, rapid, inexpensive, and reproducible.

Animals↗
PubMed2006

Effects of sucralfate, cimetidine and rabeprazole on mucosal hydroxyproline content in healing of ethanol-hcl-induced gastric lesions.

1. No general consensus has been reached on the treatment of acute gastric lesions. The aims of the present study were to clarify the effects of sucralfate, cimetidine and rabeprazole monotherapies and combination therapies on acute gastric lesions from the viewpoint of connective tissue regeneration. 2. Gastric lesions were experimentally created by the oral administration of 50% ethanol-0.15 mol/L HCl to rats. After 30 min, the anti-ulcer agents sucralfate (100 mg/kg), cimetidine (20 mg/kg) and rabeprazole (2 mg/kg) were administered separately or in combination and the stomach was excised at different times to measure the level of hydroxyproline in the gastric mucosa and determine lesion index. Immunostaining against prolylhydroxylase was performed on some specimens. 3. In the control group, lesion index decreased linearly from 30 min after ethanol-HCl administration and the level of mucosal hydroxyproline peaked between 2 and 4 h later. Although sucralfate significantly promoted lesion healing, it had no effect on mucosal hydroxyproline level. Cimetidine suppressed increases in mucosal hydroxyproline and prolonged lesion healing, but these findings were reversed by combining cimetidine and sucralfate. Rabeprazole had no significant effect on lesion healing, but promoted lesion healing in combination with sucralfate. Immunohistochemical analysis showed that prolylhydroxylase was expressed in spindle cells that lined the glandular cells in a boundary area between normal and injured tissues. 4. Under conditions in which the effects of intragastric pH are minimal, sucralfate is superior to antisecretory agents in promoting the healing of acute gastric lesions.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2006

Long-term follow-up study of bioactive bone cement in canine total hip arthroplasty.

We report a long-term study of bioactive bone cement (BABC) in a canine total hip arthroplasty (THA) at follow-up of 8 years. Previous studies have shown excellent biomechanical and histological results at follow-up of 6, 12, and 24 months. In the present study, THA was performed in a beagle dog using BABC consisting of an apatite- and wollastonite-containing glass ceramic (AW-GC) powder and SiO2 powder as the filler and a bisphenol-a-glycidyl methacrylate (Bis-GMA) based resin as the organic matrix. Histological examination showed direct bonding between BABC and bone without any intervening soft tissue layer at the BABC-bone interface. A reactive layer, through which BABC bonded to the bone, was observed thicker at 8 years than it was at 24 weeks. No adverse effects of BABC were observed. BABC maintained the high bioactivity and direct bonding to bone in a canine THA at follow-up of 8 years.

Animals↗
PubMed2006

[Sudden death due to pulmonary tumor embolism from testicular tumor: a case report].

A 40-year-old man undergoing treatment for testicular tumor with para-aortic lymph node metastasis was transferred to our department because of pulmonary embolism. Thrombolysis therapy improved his respiratory state and deep venous thrombi disappeared. However, cardiopulmonary arrest occurred suddenly. Autopsy showed tumor cell invasion into the intima of the pulmonary artery and dissection with thrombosis. Thrombi had fresh components above organizing components. Sudden death due to pulmonary tumor embolism from testicular tumor is rare. In this case, the sudden death resulted from thrombosis in the pulmonary artery, not from emboli from the deep vein.

Adult↗
PubMed2005

Identification and functions of chondroitin sulfate in the milieu of neural stem cells.

The behavior of cells is generally considered to be regulated by environmental factors, but the molecules in the milieu of neural stem cells have been little studied. We found by immunohistochemistry that chondroitin sulfate (CS) existed in the surroundings of nestin-positive cells or neural stem/progenitor cells in the rat ventricular zone of the telencephalon at embryonic day 14. Brain-specific chondroitin sulfate proteoglycans (CSPGs), including neurocan, phosphacan/receptor-type protein-tyrosine phosphatase beta, and neuroglycan C, were detected in the ventricular zone. Neurospheres formed by cells from the fetal telencephalon also expressed these CSPGs and NG2 proteoglycan. To examine the structural features and functions of CS polysaccharides in the milieu of neural stem cells, we isolated and purified CS from embryonic day 14 telencephalons. The CS preparation consisted of two fractions differing in size and extent of sulfation: small CS polysaccharides with low sulfation and large CS polysaccharides with high sulfation. Interestingly, both CS polysaccharides and commercial preparations of dermatan sulfate CS-B and an E-type of highly sulfated CS promoted the fibroblast growth factor-2-mediated proliferation of neural stem/progenitor cells. None of these CS preparations promoted the epidermal growth factor-mediated neural stem cell proliferation. These results suggest that these CSPGs are involved in the proliferation of neural stem cells as a group of cell microenvironmental factors.

Animals↗
PubMed2005

Volumetric quantitative analysis of tissue characteristics of coronary plaques after statin therapy using three-dimensional integrated backscatter intravascular ultrasound.

OBJECTIVES: The purpose of the present study was twofold: 1) to evaluate the usefulness of three-dimensional (3D) integrated backscatter (IB) intravascular ultrasound (IVUS) for quantitative tissue characterization of coronary plaques; and 2) to use this imaging technique to determine if six months of statin therapy alters the tissue characteristics of coronary plaques. BACKGROUND: Three-dimensional IVUS techniques for quantitative tissue characterization of plaque composition have not been developed. METHODS: Radiofrequency (RF) signals were obtained using an IVUS system with a 40-MHz catheter. The IB values of the RF signal were calculated and color-coded. The 3D reconstruction of the color-coded map was performed by computer software. A total of 18 IB IVUS images were captured at an interval of 1 mm in each plaque. A total of 52 patients with hyperlipidemia were randomized to treatment with pravastatin (20 mg/day, n = 17), atorvastatin (20 mg/day, n = 18), or diet (n = 17) for six months. The tissue characteristics of arterial plaque in each patient (one arterial segment per patient) were analyzed with 3D IB IVUS before and after treatment. RESULTS: Significant increases of fibrous volume (pravastatin: 25.4 +/- 6.5% to 28.1 +/- 6.1%; atorvastatin: 26.2 +/- 5.7% to 30.1 +/- 5.5%) and mixed lesion volume (atorvastatin: 25.5 +/- 6.6% to 28.7 +/- 5.1%) and a reduction of lipid volume (pravastatin: 25.5 +/- 5.7% to 21.9 +/- 5.3%; atorvastatin: 26.5 +/- 5.2% to 19.9 +/- 5.5%) were observed after statin therapy. CONCLUSIONS: Statin therapy reduced the lipid component in patients with stable angina without reducing the degree of stenosis. Three-dimensional IB IVUS offers the potential for quantitative volumetric tissue characterization of coronary atherosclerosis.

Aged↗
PubMed2005

Close association of Chlamydia pneumoniae IgA seropositivity by ELISA with the presence of coronary artery stenosis in haemodialysis patients.

BACKGROUND: Traditional risk factors of cardiovascular disease do not fully explain the accelerated atherosclerosis present in patients with end-stage renal disease (ESRD). The goal of this study was to identify the association of clinical and laboratory factors including seropositivity for Chlamydia pneumoniae determined by a specific enzyme-linked immunosorbent assay (ELISA) with the presence of coronary artery disease identified by coronary angiography in ESRD patients. METHODS: We prospectively enrolled 161 consecutive ESRD patients undergoing haemodialysis for >6 months (106 men, 55 women; mean age 63.1+/-10.2 years; mean dialysis duration 91.3+/-90.1 months). All patients underwent coronary angiography within 1 week after blood sampling. The associations of coronary artery disease with clinical parameters including C. pneumoniae IgA and IgG seropositivity were analysed using multiple logistic regression models. RESULTS: Coronary stenosis >50% was found in 102 of 161 haemodialysis patients (63.4%). Of the 102 patients, 75.5% were asymptomatic. Seropositivity for C. pneumoniae IgA was found in patients with coronary stenosis (77 out of 102, 75.5%) more frequently (P<0.001) than in patients without coronary stenosis (10 out of 59, 16.9%). Seropositivity for C. pneumoniae IgA but not IgG was strongly associated with the presence of coronary stenosis in multiple logistic regression analysis (odds ratio, 18.440; 95% confidence interval, 7.500-45.337), independently of the Framingham coronary risk factors, factors peculiar to ESRD or serum C-reactive protein levels. CONCLUSIONS: C. pneumoniae IgA seropositivity determined by ELISA is an independent laboratory factor indicating the presence of coronary artery stenosis in ESRD patients undergoing maintenance haemodialysis.

Aged↗
PubMed2005

Cellular basis for the automorphic curvature of rice coleoptiles on a three-dimensional clinostat: possible involvement of reorientation of cortical microtubules.

Coleoptiles of rice (Oryza sativa L.) show a spontaneous (automorphic) curvature toward the caryopsis under microgravity conditions. The possible involvement of the reorientation of cortical microtubules in automorphic curvature was studied in rice coleoptiles grown on a three-dimensional clinostat. When rice seedlings that had been grown in the normal gravitational field were transferred to the clinostat in the dark, cortical microtubules of epidermal cells in the dorsal side of the coleoptiles oriented more transversely than the ventral side within 0.5 h. The rotation on the clinostat also increased the cell wall extensibility in the dorsal side and decreased the extensibility in the ventral side, and induced automorphic curvature. The reorientation of cortical microtubules preceded the changes in the cell wall extensibility and the curvature. The irradiation of rice seedlings with white light from above inhibited microtubule reorientation and changes in the cell wall extensibility, as well as curvature of coleoptiles. Also, colchicine, applied to the bending region of coleoptiles, partially inhibited the automorphic curvature. These results suggest that reorientation of cortical microtubules is involved in causing automorphic curvature in rice coleoptiles on the clinostat.

Cell Wall↗