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T Yoshida

Publications and source records attributed to T Yoshida.

At least 109 records · Page 6Linked to original sources
PubMed2002

Observation of structures of chain vortices inside anisotropic high- Tc superconductors.

In order to elucidate the formation mechanism of unconventional arrangements of vortices in high- Tc superconducting thin films at an inclined magnetic field to the layer plane, we investigated the structures of vortex lines inside the films by Lorentz microscopy using our 1-MV field-emission electron microscope. Our observation results concluded that vortex lines are tilted to form linear chains in YBaCu3O(7,8). Vortex lines in the chain-lattice state in Bi2Sr2CaCu2O(8+delta), on the other hand, are all perpendicular to the layer plane, and therefore only vortices lined up along Josephson vortices form chains.

Journal Article↗
PubMed2002

Effects of carbon dioxide pneumoperitoneum on hemodynamics in cirrhotic rats.

BACKGROUND: The aim of our study was to investigate the effect of carbon dioxide pneumoperitoneum on systemic and splanchnic hemodynamics in cirrhotic rats. METHODS: Sprague-Dawley rats (n = 80) were used in this study. Liver cirrhosis was induced by thioacetamide administration intraperitoneally (200 mg/kg body weight, twice a week for 16 weeks). The radioactive microsphere method was used to measure systemic and regional hemodynamic parameters before, 1 h after the start, and 1 h after the release of pneumoperitoneum. RESULTS: Splanchnic blood flow and cardiac index were significantly depressed during pneumoperitoneum in liver cirrhosis and control groups, but no significant differences were seen between the two groups. In both groups, portal venous inflow decreased and hepatic arterial blood flow increased significantly during pneumoperitoneum. However, during pneumoperitoneum, total hepatic blood flow as a percentage of its value before pneumoperitoneum was lower in cirrhotic rats (71.0%) than in control rats (91.9%) (p <0.05, Mann-Whitney U-test). CONCLUSIONS: Carbon dioxide pneumoperitoneum markedly decreases total hepatic blood flow in cirrhotic rats due to the impaired hepatic arterial buffer response. Liver function should be carefully controlled in cirrhotic patients after laparoscopic surgery with pneumoperitoneum.

Animals↗
PubMed2002

The acceleration of cosmic-ray protons in the supernova remnant RX J1713.7-3946.

Protons with energies up to approximately 10(15) eV are the main component of cosmic rays, but evidence for the specific locations where they could have been accelerated to these energies has been lacking. Electrons are known to be accelerated to cosmic-ray energies in supernova remnants, and the shock waves associated with such remnants, when they hit the surrounding interstellar medium, could also provide the energy to accelerate protons. The signature of such a process would be the decay of pions (pi(0)), which are generated when the protons collide with atoms and molecules in an interstellar cloud: pion decay results in gamma-rays with a particular spectral-energy distribution. Here we report the observation of cascade showers of optical photons resulting from gamma-rays at energies of approximately 10(12) eV hitting Earth's upper atmosphere, in the direction of the supernova remnant RX J1713.7-3946. The spectrum is a good match to that predicted by pion decay, and cannot be explained by other mechanisms.

Journal Article↗
PubMed2002

Measurements of cosmic-ray low-energy antiproton and proton spectra in a transient period of solar field reversal.

The energy spectra of cosmic-ray low-energy antiprotons ( *p's) and protons ( p's) have been measured by BESS in 1999 and 2000, during a period covering reversal at the solar magnetic field. Based on these measurements, a sudden increase of the *p/p flux ratio following the solar magnetic field reversal was observed, and it generally agrees with a drift model of the solar modulation.

Journal Article↗
PubMed2002

Urinary 2,5-dichlorophenol as biological index for p-dichlorobenzene exposure in the general population.

The relationship between exposure to p-dichlorobenzene (p-DCB) and urinary excretion of 2,5-dichlorophenol (2,5-DCP), the major metabolite of p-DCB, was examined to evaluate the usefulness of the metabolite as a biological index for low-level exposure of p-DCB in the general population. Personal exposure concentrations of p-DCB and concentrations of 2,5-DCP excreted in the urine of 119 adults living in Osaka were determined. Airborne p-DCB was collected for 24 h by passive gas sampling tubes packed with charcoal. The tubes were exchanged every 12 h. The sampling was started immediately after the subject woke up in the morning (7 A.M.). The collected p-DCB was desorbed with toluene and measured using a gas chromatograph with an electron capture detector (GC-ECD). On the other hand, the first morning urine samples were collected at the endpoint of airborne p-DCB sampling (7 A.M. the next morning). The urine samples were hydrolyzed with concentrated sulfuric acid. 2,5-DCP in the hydrolysates was extracted with n-hexane and measured by GC-ECD. Both p-DCB and 2,5-DCP were detected in more than 99% of the air and urine samples, respectively, from the participants. The median of p-DCB exposure concentrations for 24 h was 2.5 ppb, with a maximum concentration of 33.3 ppb. The median of urinary 2,5-DCP concentrations was 0.39 mg/g creatinine, with the maximum concentration of 3.32 mg/g creatinine. The regression line between the urinary 2,5-DCP concentration (y) and the p-DCB exposure concentration (x) was y = 0.080 x + 0.181, with the Pearson correlation coefficient of 0.81 (p < 0.001), demonstrating a strong association between these measurements. Consequently, urinary 2,5-DCP should be suitable as an index for monitoring low-level exposure of p-DCB in the general population.

Adult↗
PubMed2002

Molecular detection and diversity of polycyclic aromatic hydrocarbon-degrading bacteria isolated from geographically diverse sites.

Nineteen polycyclic aromatic hydrocarbon (PAH)-degrading bacteria were isolated from environmental samples in Kuwait, Indonesia, Thailand, and Japan by enrichment with either naphthalene or phenanthrene as a sole carbon source. Sequence analyses of the 16-S rRNA gene indicated that at least seven genera (Ralstonia, Sphingomonas, Burkholderia, Pseudomonas, Comamonas, Flavobacterium, and Bacillus) were present in this collection. Determination of the ability of the isolates to use PAH and its presumed catabolic intermediates suggests that the isolates showed multiple phenotypes in terms of utilization and degradation pathways. The large subunit of the terminal oxygenase gene (phnAc) from Burkholderia sp. strain RP007 hybridized to 32% (6/19) of the isolates, whilst gene probing using the large subunit of terminal oxygenase gene (pahAc) from Pseudomonas putida strain OUS82 revealed no pahAc-like genes amongst the isolates. Using three degenerated primer sets (pPAH-F/NR700, AJ025/26, and RieskeF/R), targeting a conserved region with the genes encoding the large subunit of terminal oxygenase successfully amplified material from 6 additional PAH-degrading isolates. Sequence analyses showed that the large subunit of terminal oxygenase in 4 isolates was highly homologous to the large subunit of naphthalene dioxygenase gene from Ralstonia sp. strain U2. However, we could not obtain any information on the oxygenase system involved in the naphthalene and/or phenathrene degradation by 7 other strains. These results suggest that PAH-degrading bacteria are diverse, and that there are still many unidentified PAH-degrading bacteria.

Asia↗
PubMed2002

Induction and mechanism of apoptotic cell death by propofol in HL-60 cells.

BACKGROUND: Apoptosis (programmed cell death) occurs in various physiological and pathological conditions, exhibits a characteristic mechanism of intracellular sequential reaction and may be involved in determining clinical outcome. The antioxidant activity of propofol (2,6-diisopropylphenol) together with the stimulating effect of protein kinase C suggests that propofol might have the potential to modulate apoptosis. Thus, it is of both clinical interest and biomedical importance to investigate and clarify the effect and mechanism of propofol upon the intracellular reactions underlying apoptotic cell death. METHODS: The effect of propofol on apoptosis was investigated using cultured human promyelocytic leukemia HL-60 cells. This well-characterized cell line is useful for the study of apoptosis because the various biochemical steps occurring during apoptosis have been well documented. RESULTS: Treatment of HL-60 cells with propofol resulted in growth inhibition with the formation of apoptotic bodies in a concentration-dependent manner. DNA fragmentation and ladder formation was also observed in a concentration-dependent manner. Propofol treatment resulted in activation of caspase-3, -6, -8 and -9, thereby suggesting that cell surface death receptor activation of the caspase cascade mediates propofol-induced apoptosis with consequent formation of the cleaved product of Bid (a pro-apoptotic Bcl-2 family member protein) and activation of the mitochondrial pathway with cytosolic release of cytochrome c. CONCLUSION: Propofol may induce apoptosis, which is dependent on the mechanism that activates both the cell surface death receptor pathway and the mitochondrial pathway.

Anesthetics, Intravenous↗
PubMed2002

The expression of tenascin mRNA in human temporomandibular joint specimens.

The expression of mRNA of tenascin in the temporomandibular joint (TMJ) disc and synovial membrane was examined in 20 human TMJ samples from patients with internal derangement of the TMJ and 10 control specimens by in situ hybridization technique using paraffine-embedded tissue, and antisense and sense cRNA probes. In control specimens, tenascin mRNA was not expressed. However, we were able to find tenascin mRNA expression in the surgical specimens. In 15 of 20 samples, ranging numbers of synovial cells expressed tenascin mRNA in the hypertrophic synovial membranes. Also, in 6 of 20 samples, tenascin mRNA was identified in fibroblasts. In four specimens, vascular endothelial cells were positive for the mRNA. In internal derangement cases, histopathological findings are often found such as synovitis, new capillary growth and fibrosis. The present study demonstrates that tenascin is produced specifically in synovial cells, vascular endothelial cells and fibroblasts affected in the portion of TMJ with internal derangement.

Adult↗
PubMed2002

Increased rectal wall thickness may predict relapse in ulcerative colitis: a pilot follow-up study by ultrasonographic colonoscopy.

BACKGROUND AND STUDY AIMS: Ulcerative colitis is a chronic inflammatory bowel disease with repeated remission and relapse, although the occurrence of relapse is difficult to predict. We performed a prospective study to determine whether there is a relationship in ulcerative colitis between the inflammatory changes identified by endoscopic ultrasonography (EUS) and relapse. PATIENTS AND METHODS: Participants were 23 ulcerative colitis patients who had not suffered a relapse for 1 month, with a Seo activity index less-than-or-equal 150 and Baron grade 1 at colonoscopy. The thickness of the first to the third layer of the rectal wall in these patients was measured by EUS at the start of the study. They were subsequently followed up for 1 year to record any relapses, defined as having a Seo activity index > 150 and Baron grade greater-than-or-equal 2 at colonoscopy. RESULTS: Relapse occurred in eight patients. The mean activity index of the relapsed patients was 187.3 (95 % confidence interval (CI), 166.4 - 208.2) at the end of the study. The thickness of the first to the third layer of the rectal wall, as evaluated by EUS at the beginning of the study, was significantly larger in the relapse group (mean 2.73 mm, 95 % CI 2.13 - 3.33 mm) than in the non-relapse group (1.79 mm; 1.56 - 1.99 mm; P = 0.0001). CONCLUSIONS: Catheter probe-assisted endoluminal ultrasonography may predict the occurrence of relapse of ulcerative colitis.

Adult↗
PubMed2002

Expression of tenascin in bile duct cancer of hamster liver by combined treatment of dimethylnitrosamine with Opisthorchis viverrini infections.

Tenascin is an extracellular matrix glycoprotein known to be an essential factor for the modulation of reciprocal interactions between the epithelium and mesenchyme during embryogenesis and tumourigenesis. The interactions between the expression of tenascin in the liver of Syrian golden hamster and the development of bile duct cancer in an Opisthorchis viverrini-associated cholangiocarcinoma model were investigated. The tenascin was expressed in connective tissues surrounding the dilated ducts, ductal rims and the stroma of cancers, and strongly in the stroma flame of necrotic cancer nodules. The mRNA signal for tenascin was also recognized in the stroma cells. The potential roles of tenascin as prognostic tumour markers are discussed.

Animals↗
PubMed2002

3D culture of murine hematopoietic cells with spatial development of stromal cells in nonwoven fabrics.

BACKGROUND: The in vivo hematopoietic microenvironment is composed of stromal cells and extracellular matrix in a 3D configuration. We have created a 3D microenvironment in vitro, employing spatial development of stromal cells in a nonwoven fabric porous carrier, Fibra-cel (FC). We compared its performance with that of a 2D microenvironment. METHODS: Primary murine BM cells were inoculated on the layers of stromal cells prepared in FC (3D) or on a dish (2D) and cultured for 7-21 days. The hematopoietic cells harvested from the cultures were evaluated by colony-forming unit (CFU) assay and transplantation to sub lethally irradiated mice. RESULTS: The maximum stromal cell concentration in the 2D culture was higher than that in the 3D culture. However, the hematopoietic cell concentration in the 3D culture was kept at a higher level than that in the 2D culture. The number of CFU-mix increased five times during 3D cultivation, but decreased in the 2D culture. The engraftment percentage of 3D cultured cells was comparable with that of fresh cells, and markedly higher than that of 2D cultured cells. DISCUSSION: The 3D culture constructed with FC and stromal cells was clearly superior to 2D culture because hematopoietic progenitor cells were expanded without the addition of cytokines and the content of hematopoietic stem cells was maintained.

Animals↗
PubMed2002

Beneficial effect of JTV-803, a new synthetic inhibitor of activated factor X, against both lipopolysaccharide-induced and tissue factor-induced disseminated intravascular coagulation in rat models.

We examined whether JTV-803, a specific activated factor X inhibitor independent of antithrombin III (ATIII), is effective against disseminated intravascular coagulation (DIC) in rat models induced by tissue factor (TF) or lipopolysaccharides (LPS). In male Wistar rats, DIC was induced by a 4 h infusion of thromboplastin (3.75 U/kg) or LPS (50 mg/kg). The rats were given JTV-803 (0.3 or 3 mg/kg, bolus intravenously) (JTV-803 groups) or low molecular weight heparin (LMWH groups) (200 U/kg, bolus intravenously) prior to an injection of TF or LPS. The results showed that JTV-803 was dose-dependently effective against DIC in both TF-induced and LPS-induced rat models. This anti-DIC effect of JTV-803 at higher doses was almost equivalent to that of LMWH in both types of DIC. Plasma ATIII activity was more prominent in the group treated with JTV-803 than in that treated with LMWH. None of rats died in the TF-induced DIC model with or without drug administration. On the contrary, seven of 22 rats died (mortality rate, 31.8%) in the LPS-induced DIC model without drug administration. Although the mortality rate of rats induced with LPS and treated with LMWH was quite high (6/16, 37.5%), none of the LPS-induced rats treated with JTV-803 died. These findings suggested that JTV-803 can treat both TF-induced and LPS-induced DIC models, and that this drug has greater potential in preserving ATIII and in improving the prognosis of DIC.

Animals↗
PubMed2002

Distribution and partial characterisation of IgG Fc binding protein in various mucin producing cells and body fluids.

BACKGROUND AND AIMS: Mucus released from goblet cells is important in intestinal mucosal defence, and mucin glycoproteins are thought to be major components of mucus. Recently, we identified and cloned another component of human colonic mucus, IgG Fc binding protein (Fc gamma BP). Fc gamma BP is immunologically distinct from known Fc gamma receptors and its structure contains repeated cysteine rich unit sequences resembling those present in mucins. In this work, we assessed the tissue distribution of Fc gamma BP, its binding activity in various body fluids, and its ability to inhibit complement mediated haemolysis. METHODS: Immunohistochemical localisation of Fc gamma BP, using monoclonal antibodies against Fc gamma BP (K9 or K17) and labelled IgG, was conducted in various mucin producing tissues: colon, small intestine, stomach, gall bladder, cystic duct, choledochus, bronchus, submandibular gland, conjunctiva, and cervix uteri. The binding activity of Fc gamma BP in mucus extracted from colon, gastric juice, bile, nasal discharges, saliva, sputum, and tears was also examined by immunodotblot and immunoprecipitation using these monoclonal antibodies. Inhibition of complement mediated haemolysis by Fc gamma BP was investigated using sheep red blood cells (SRBC) and anti-SRBC IgG. RESULTS: The immunohistochemical study revealed that mucin secreting cells in the colon, small intestine, gall bladder, cystic duct, choledochus, bronchus, submandibular gland, and cervix uteri contained Fc gamma BP, and immunodotblot and immunoprecipitation analysis using IgG and monoclonal antibodies demonstrated that the fluids secreted by these cells were capable of binding IgG. Mucin producing cells of the conjunctiva did not express Fc gamma BP molecules or bind to IgG. The surface mucus cells in the stomach were variably positive for Fc gamma BP. Perhaps because of proteolytic degradation, Fc gamma BP in gut lavage fluid did not have IgG binding activity, although this activity was present in the mucus covering the colon. Fc gamma BP suppressed complement mediated haemolysis of SRBC. CONCLUSIONS: Fc gamma BP is widely expressed on mucosal surfaces and in external secretions. It is functionally intact in several fluids. These findings lend support to the concept that Fc gamma BP is an important component of mucosal immunological defences.

Animals↗
PubMed2002

Correcting for signal saturation errors in the analysis of microarray data.

A variety of technical errors have arisen in data analysis when using cDNA or oligonucleotide microarrays. One of the most insidious problems is the saturation of the hybridization signal of high-abundant transcripts. This problem arises from the truncation of the laser fluorescence signal. When the hybridization signal on the microarray is very strong, this truncation can result in serious consequences that may not be readily apparent to the user. As an illustration of this problem, two subclasses of normal human tissue samples (six liver and six lung samples) were analyzed with GeneChip probe arrays to evaluate the patterns of expression for approximately 7000 human genes. Five of these data sets were found to suffer from signal truncation. This caused several tissues to be incorrectly classified using hierarchical clustering. To rectify this problem so that the gene expression data could be properly compared and clustered, we developed a "filtering" procedure that identifies a subset of genes least affected by the signal saturation. This filtering procedure can be obtained at www.hugeindex.org.

Aged↗
PubMed2002

Bacterium-based heavy metal biosorbents: enhanced uptake of cadmium by E. coli expressing a metallothionein fused to beta-galactosidase.

We investigated the potential utility of a recombinant E. coli that expresses the human metallothionein II gene as a fusion protein with beta-galactosidase as a heavy metal biosorbent. E. coli cells expressing the metallothionein fusion demonstrated enhanced binding of Cd2+ compared to cells that lack the metallothionein. It was shown that the metallothionein fusion was capable of efficiently removing Cd2+ from solutions. Approximately 40% of the Cd2+ accumulated by the recombinant cells free in suspension was associated with the outer cell membrane, and 60% of that was present in the cytoplasm.

Biodegradation, Environmental↗
PubMed2002

[A review of Japanese literatures concerning surgery for lung cancer with idiopathic interstitial pneumonia].

OBJECTIVE: The aim of the present study is to investigate the perioperative management of acute exacerbation of idiopathic interstitial pneumonia (IIP) after pulmonary resection for lung cancer. METHODS: We reviewed 5 Japanese literatures published from 1992 through 1998. The present study included 50 lung cancer patients with IIP, of which 3 were our cases and 47 were reported cases. RESULTS: Within 30 days after operation, acute exacerbation of IIP occurred in 12 cases (24.0%). Preoperative profiles (gender, age, smoking status, respiratory function, pathologic stage) of the exacerbated cases did not differ from those of non-exacerbated cases. The mean intraoperative PaO2 of the exacerbated cases was significantly higher than that of non-exacerbated cases (224 +/- 45.6 Torr vs 120 +/- 41.2 Torr, p = 0.005). The rate of acute exacerbation increased with the extent of resection, that is 42.8% in pneumonectomy, 24.3% in lobectomy, and 0% in wedge resection although the difference was not significant. After acute exacerbation of IIP, all 12 cases were given high doses of steroids. However, 11 cases died due to the disease progression (mortality rate = 91.7%). CONCLUSION: In order to establish the perioperative management for prevention of acute exacerbation of IIP, multi-institutional study is warranted on the basis of the present results (intraoperative FiO2, administration schedule of steroids etc).

Aged↗