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Biomedical subjects

T Fujita

Publications and source records attributed to T Fujita.

At least 55 records · Page 3Linked to original sources
PubMed2005

Involvement of retinoic acid-inducible gene-I in the IFN-{gamma}/STAT1 signalling pathway in BEAS-2B cells.

Bronchial epithelial cells play an important role in airway host defence, and interferon (IFN)-gamma controls immune reactions by regulating the expression of various genes in bronchial epithelial cells. Signal transducer and activator of transcription 1 (STAT1) is the key transcriptional factor in IFN-gamma signalling. Retinoic acid-inducible gene-I (RIG-I) is a member of the DExH box family of proteins and designated a putative RNA helicase. RNA helicases play diverse roles in regulation of gene expression and cellular functions, and RIG-I is implicated in antiviral responses. The aim of the present study was to investigate the effect of IFN-gamma on RIG-I expression in a cell line derived from human bronchial epithelial cells, BEAS-2B. Induction of RIG-I in response to IFN-gamma was found in BEAS-2B cells. Induction of RIG-I by IFN-gamma was also demonstrated in another pulmonary epithelial cell line, NCI-H292. Transfection of BEAS-2B cells with RIG-I complementary DNA resulted in the upregulation of STAT1. Induction of IFN-gamma-inducible protein 10 by IFN-gamma was enhanced in the cells overexpressing RIG-I. It is concluded that retinoic acid-inducible gene-I may play an important role in the regulation of immunological reactions in bronchial epithelial cells elicited by interferon-gamma.

Cells, Cultured↗
PubMed2004

Oxidative stress induces insulin resistance by activating the nuclear factor-kappa B pathway and disrupting normal subcellular distribution of phosphatidylinositol 3-kinase.

AIMS/HYPOTHESIS: Oxidative stress is associated with diabetes, hypertension and atherosclerosis. Insulin resistance is implicated in the development of these disorders. We tested the hypothesis that oxidative stress induces insulin resistance in rats, and endeavoured to identify mechanisms linking the two. METHODS: Buthionine sulfoximine (BSO), an inhibitor of glutathione synthase, was administered to Sprague-Dawley rats and 3T3-L1 adipocytes. Glucose metabolism and insulin signalling both in vivo and in 3T3-L1 adipocytes were examined. In 3T3-L1 adipocytes, the effects of overexpression of a dominant negative mutant of inhibitory kappa B (I kappa B), one role of which is to block oxidative-stress-induced nuclear factor (NF)-kappa B activation, were investigated. RESULTS: In rats given BSO for 2 weeks, the plasma lipid hydroperoxide level doubled, indicating increased oxidative stress. A hyperinsulinaemic-euglycaemic clamp study and a glucose transport assay using isolated muscle and adipocytes revealed insulin resistance in BSO-treated rats. BSO treatment also impaired insulin-induced glucose uptake and GLUT4 translocation in 3T3-L1 adipocytes. In BSO-treated rat muscle, adipose tissue and 3T3-L1 adipocytes, insulin-induced IRS-1 phosphorylation in the low-density microsome (LDM) fraction was specifically decreased, while that in whole cell lysates was not altered, and subsequent translocation of phosphatidylinositol (PI) 3-kinase from the cytosol and the LDM fraction was disrupted. BSO-induced impairments of insulin action and insulin signalling were reversed by overexpressing the dominant negative mutant of I kappa B, thereby suppressing NF-kappa B activation. CONCLUSIONS/INTERPRETATION: Oxidative stress induces insulin resistance by impairing IRS-1 phosphorylation and PI 3-kinase activation in the LDM fraction, and NF-kappa B activation is likely to be involved in this process.

3T3 Cells↗
PubMed2004

Formation of advanced tokamak plasmas without the use of an ohmic-heating solenoid.

A new operational scenario of advanced tokamak formation was demonstrated in the JT-60U tokamak. This was accomplished by electron cyclotron and lower hybrid waves, neutral beam injection, and the loop voltage supplied by the vertical field and shaping coils. The Ohmic heating (OH) solenoid was not used but a small inboard coil (part of the shaping coil), providing less than 20% of total poloidal flux, was used. The plasma thus obtained had both internal and edge transport barriers, with an energy confinement time of 1.6 times H-mode scaling, a poloidal beta of 3.6, and a normalized beta of 1.6, and a large bootstrap current fraction (>90%). This result opens up a possibility to reduce, and eventually eliminate, the OH solenoid from a tokamak reactor, which will greatly improve its economic competitiveness.

Journal Article↗
PubMed2004

Effect of dietary protein intake on plasma leucine flux, protein synthesis, and degradation in sheep.

Combined experiments of an isotope dilution method of [1-(13)C]leucine with open circuit calorimetry and a nitrogen (N) balance test were applied to determine the effect of dietary crude protein (CP) intake on plasma leucine flux and protein synthesis and degradation in four sheep. The experiment was conducted in a 3 x 4 Latin rectangle design of three 3-week periods. Dietary CP intake was 5.6, 7.7, and 10.8 g/(kg(0.75) x d). Metabolizable energy intake was 120% of requirement for all dietary treatments. [1-(13)C]Leucine was intravenously infused for 8 h and blood and breath samples were collected during the latter 2-h period of infusion. Isotopic enrichments of plasma [1-(13)C]leucine, alpha-[1-(13)C]ketoisocaproic acid, and exhaled (13)CO(2) were determined. For the N balance test, N digestibility, N excretion in urine, and protein balance (N x 6.25) increased with increasing dietary CP intake. Rates of plasma leucine turnover, protein synthesis, and degradation changed toward reduction with increased dietary CP intake. It is likely that in sheep, high CP intake enhances protein deposition with reduced protein degradation rather than increased protein synthesis.

Animals↗
PubMed2004

Modulation by adenosine of Adelta and C primary-afferent glutamatergic transmission in adult rat substantia gelatinosa neurons.

The present study examined the actions of adenosine on monosynaptic Adelta and C primary-afferent excitatory postsynaptic currents (EPSCs) recorded from substantia gelatinosa (SG) neurons of an adult rat spinal cord slice. In 67% of the neurons examined, adenosine reversibly decreased the amplitude of the Adelta-fiber EPSC, while in 13% of the neurons the amplitude was reduced or unaffected, which was followed by its increase persisting for several minutes after adenosine washout. The remaining neurons did not exhibit a change in the amplitude. The reduction in Adelta-fiber EPSC amplitude by adenosine was dose-dependent with an effective concentration for half-inhibition (EC50) value of 217 microM. When examined by using a paired-pulse stimulus, a ratio of the second to first Adelta-fiber EPSC amplitude under the reduction was larger than that of EPSC amplitude in the control, suggesting a presynaptic action of adenosine. In 69% of the neurons tested, the C-fiber EPSC was reversibly decreased in amplitude by adenosine (100 microM) by an extent comparable to that of Adelta-fiber EPSC; the remaining neurons were without adenosine actions. Similar inhibitory actions of adenosine were also seen in neurons where both Adelta-fiber and C-fiber EPSCs were elicited. Similar reduction in the Adelta-fiber or C-fiber EPSC amplitude was induced by an A1 adenosine-receptor agonist, N6-cyclopentyladenosine (1 microM), and the adenosine-induced reduction was not observed in the presence of an A1 antagonist, 8-cyclopentyl-1,3-dipropylxanthine (1 microM). An A2a agonist, CGS 21680 (1 microM), did not significantly affect the Adelta-fiber EPSC amplitude. It is concluded that adenosine presynaptically inhibits monosynaptic Adelta-fiber and C-fiber transmission by a similar extent through the activation of the A1 receptor in many but not all SG neurons; this could contribute to at least a part of antinociception by intrathecally administered adenosine analogues and probably by endogenous adenosine.

Adenosine↗
PubMed2004

Influence of microcatheter length on flow rates of disposable infusion kits.

BACKGROUND AND OBJECTIVE: Continuous spinal analgesia (CSA) offers considerable pain relief, and has been used in various procedures such as for surgery and cancer pain control. In Japan, portable and disposable infusion kits are increasingly employed for continuous epidural analgesia and CSA. In CSA, the use of a microcatheter is expected to reduce the incidence of spinal headache previously encountered with larger catheters. However, the flow rate of disposable infusion kits is reduced when used in conjunction with a microcatheter. METHODS: This study aimed to investigate the influence of catheter length on the flow rate of two different devices: 20- or 91-cm 28-G microcatheters connected to balloon- or syringe-type infusion pumps were examined (50 mL, 1 mL h(-1)). There were four groups each of 10 experiments: Group A: balloon-type infuser, 91 cm catheter; Group B: balloon-type infuser, 20 cm catheter; Group C: syringe-type infuser, 91 cm catheter; Group D: syringe-type infuser, 20 cm catheter. RESULTS: The mean flow rate in Group A was significantly less than that in Group B and the mean flow rate in Group C was significantly less than Group D (P < 0.05). CONCLUSION: These results indicated that the use of a shorter microcatheter achieves a better flow rate during CSA.

Analgesia, Epidural↗
PubMed2004

Monitoring of the generation of non-mutagenic benzoic acid compounds during the manufacture of erythrosine.

The generation of 2-(2',4'-dihydroxybenzoyl) benzoic acid (DHBBA) and 2-(2',4'-dihydroxy-3',5'-diiodobenzoyl) benzoic acid (DHDIBBA) during the manufacture of erythrosine (Food Red No. 3) was examined. DHBBA is formed as an intermediate during the synthesis of fluorescein, and as fluorescein is produced, it is gradually consumed. However, under inappropriate reaction conditions, it remains in the resulting fluorescein at the termination of synthesis. DHDIBBA is easily obtained by the iodination of DHBBA. These compounds are also found when erythrosine is heated in excessive alkali. The results of the Ames test using DHBBA and DHDIBBA showed they did not possess mutagenic activity. The results clearly demonstrated that establishment of an upper limit for DHBBA and DHDIBBA is important in the quality control of fluorescein and erythrosine.

Benzoic Acid↗
PubMed2004

The effect of solar irradiation on the fading of nylon and polyester fabrics dyed with selected disperse dyestuffs on radiant energy basis.

Solar total, UVA and UVB irradiances were measured separately using three kinds of wavelength band detectors in Tokyo, Japan in November 1999. Characteristics of diurnal variations were examined: Total irradiance reached a maximum value of about 600 W m(-2) at around noon. The variation pattern of UVA irradiance was observed to be similar to the total irradiance. The energy level was about 4.65% of total irradiance. Diurnal variation of UVB was in the form of a steeper bell curve due to the absorption in the air mass. UVB energy to solar total irradiance was about 0.07%. Photodegradation characteristics of two disperse dyestuffs were investigated on the basis of solar radiant energy. A UVA fluorescent lamp was applied to examine the fading characteristics to find the wavelength dependency. As a result, nylon dyeings were less lightfast by a factor of about 6 and 13 for C I Disperse Blue 27 and C I Disperse Blue 165, respectively, compared with polyester on the radiant energy basis. Visible light, as well as UVA, radiation contribute to fading of C I Disperse Blue 165 whereas UVA mostly cause the fading of C I Disperse Blue 27.

Coloring Agents↗
PubMed2004

Crystallographic orientation contrast associated with Ga+ ion channelling for Fe and Cu in focused ion beam method.

In this study, Cu and Fe single crystals are used to examine the change in secondary electron intensity associated with Ga(+) ion channelling in a focused ion beam (FIB) system. The single crystals having three different orientations are tilted with respect to the beam incidence and the resulting variation in the secondary electron intensity is measured through the variation in brightness of the crystals. It is shown that intensity minima appear at the beam directions normal to the lower indices of the crystal orientations. The appearance of the intensity minima including the magnitude of the minima is consistent with the prediction based on the event of ion channelling in the crystal and is affected by the crystal structure. The effect of background on the intensity minima is discussed in this study. It is suggested that the presence of the intensity minima may be used to identify a crystal orientation including a crystal structure.

Copper↗
PubMed2004

Effects of sex hormone disturbances on craniofacial growth in newborn mice.

It is well-known that sex hormones influence bone metabolism. However, it remains unclear as to how sex hormones affect bone growth in newborn mice. In this study, we performed orchiectomy (ORX) and ovariectomy (OVX) on newborn mice, and examined the effects on craniofacial growth morphometrically. ORX and OVX were performed on five-day-old C57BL/6J mice. Four weeks after surgery, lateral cephalograms were taken of all of the mice, with the use of a rat and mouse cephalometer. Cephalometric analysis of the craniofacial skeleton was performed by means of a personal computer. Inhibition of craniofacial growth was found in the experimental groups but not in the sham-operated groups. In the nasomaxillary bone and mandible, the amount of growth was significantly reduced. These results suggest that craniofacial growth is inhibited by sex hormone disturbances not only in puberty but also immediately after birth.

Age Factors↗
PubMed2004

Severity dependent up-regulations of LOX-1 and MCP-1 in early sclerotic changes of common carotid arteries in spontaneously hypertensive rats.

Lectin-like oxidized low-density lipoprotein receptor (LOX-1) and monocyte chemoattractant protein-1 (MCP-1) are molecules involving in the initiation and progression of atherosclerosis. In order to examine a possible difference in LOX-1 and MCP-1 expressions depending on the severity of early stage of atherosclerosis, we investigated atherosclerotic changes by exposure to hypertension and hyperlipidemia in common carotid arteries (CCAs) of stroke-prone spontaneously hypertensive rat (SHR-SP). Three rat model groups such as control [Wistar Kyoto rat (WKY) group], hypertension (SHR-SP group) and hypertension + hyperlipidemia [SHR-SP + high fat and cholesterol (HFC) group] were used. Body weights, brain weights, systolic blood pressures and serum levels of total cholesterol, low-density lipoprotein and triglyceride were measured at 0, 5, 10 and 15 days after appropriate diet. Immunohistochemistry showed that the positive area and the strength of LOX-1 and MCP-1 were larger in the SHR-SP + HFC group than in the SHR-SP group, while no immunoreactivities were found in the WKY group. Conventional RT-PCR and real-time PCR analyses showed that mRNAs of those in the SHR-SP group were higher with greater up-regulation in the SHR-SP + HFC group. LOX-1 and MCP-1 expressions were coordinately up-regulated at mRNA and protein levels in an early stage of sclerosis depending on the severity of atherosclerotic stress. Activations of LOX-1 and MCP-1 are collectively involved in the early stage of atherosclerosis.

Animals↗
PubMed2004

Active Absorbable Algal Calcium (AAA Ca): new Japanese technology for osteoporosis and calcium paradox disease.

Active Absorbable Algal Calcium (AAA Ca) is made by submaximally (800 degrees C) heating cleaned oyster shell under reduced pressure and mix it with similarly heated seaweed (Cystophyllum fusiforme). AAA Ca, best absorbed from the intestine among available calcium compounds, consequently most efficiently suppresses parathyroid hormone secretion, increases bone mineral density and decreases vertebral fracture. Aging is associated with calcium deficiency, mostly because of the decreased biosynthesis of 1,25 (OH)2 vitamin D in the kidney. Parathyroid hormone consequently increases, contributing to various diseases associated with aging such as osteoporosis or decrease of calcium in the bone, as well as hypertension, arteriosclerosis, Alzheimer's disease and osteoarthritis due to paradoxical increase of calcium in vascular walls, brain, cartilage and intracellular compartment of many kinds of cells. Mild calcium deficiency is hard to detect despite these serious consequences because of the remarkable constancy of blood calcium concentration maintained by elaborate homeostatic control. Only by successfully counteracting calcium deficiency by AAA Ca with outstanding absorbability, the phenomenon of calcium paradox becomes a recognizable reality within our reach.

Animals↗
PubMed2003

Dynamics of microbial populations and strong selection for Cycloclasticus pugetii following the Nakhodka oil spill.

Microbial population changes were monitored immediately after the Nakhodka oil spill accident in January 1997 at the heavily oil-contaminated Mikuni coast along the Sea of Japan. The total cell number was almost stable for one year at 2-5 x 10(5) cells mL(-1), while the relative occurrence of culturable heterotrophs and degraders of oil components such as C-heavy oil, kerosene, and n-tetradecane varied, showing a maximum (>50% of the total) immediately following the accident. Gene amplification and phylogenetic analysis of a dilution culture using C-heavy oil as the sole carbon and energy source revealed that one of the predominant oil degraders at the oil-contaminated coast in 2 weeks after the accident closely resembled the aromatic hydrocarbon decomposer Cycloclasticus pugetii. Microbial community composition in oil-contaminated seawater was estimated at the molecular level using newly developed oligonucleotide probes, probe wash-off curve estimation, and quantitative fluorescence dot-blot hybridization techniques. At two different oil-polluted sites, harbor and intertidal regions, the C. pugetii group was estimated to make up 23-25% of the total Bacteria population, followed by the aliphatic hydrocarbon decomposer Alcanivorax borkumensis, which formed 4-7% of the Bacteria. In incubation experiments using floated oil slick and indigenous microbes collected at the harbor, oil degradation activities were enhanced by the addition of both organic and inorganic nutrients. Significant decreases were found in aromatic and aliphatic hydrocarbon fractions: 54-60% and 22-24% in 2 weeks to 68-77% and 23-32% in 2 months, respectively.

Base Sequence↗
PubMed2003

Pressure-induced superconductor-insulator transition in the spinel compound CuRh2S4.

We performed resistivity measurements in CuRh2S4 under quasihydrostatic pressure of up to 8.0 GPa, and found a pressure-induced superconductor-insulator transition. Initially, with increasing pressure, the superconducting transition temperature T(c) increases from 4.7 K at ambient pressure to 6.4 K at 4.0 GPa, but decreases at higher pressures. With further compression, superconductivity in CuRh2S4 disappears abruptly at a critical pressure P(SI) between 5.0 and 5.6 GPa, when it becomes an insulator.

Journal Article↗
PubMed2003

Association between RCAS1 expression and clinical outcome in uterine endometrial cancer.

RCAS1, which acts as a ligand for a putative receptor on immune cells such as peripheral lymphocytes and natural killer cells, is strongly expressed in human cancers. RCAS1 can induce these cells to undergo apoptotic cell death, which suggests that RCAS1 expression may prohibit the stromal reaction occurring in a tumour. To clarify the clinical significance of RCAS1 expression in uterine endometrial cancer, we analysed the association between RCAS1 expression and clinicopathologic variables by statistical methods. With the use of immunohistochemical techniques, we performed a retrospective study of RCAS1 expression in resected tumour tissue from 147 patients with uterine endometrial cancer. We evaluated the statistical correlation between RCAS1 expression and clinicopathologic variables. RCAS1 was expressed in 106 of 147 patients with uterine endometrial cancer; 30 of these 147 patients showed RCAS1 overexpression. Overexpression of RCAS1 was significantly correlated with age at surgery, stage, extent of myometrial invasion, and positive peritoneal cytologic results. Multivariate analysis revealed that RCAS1 expression and metastasis were clinically significant prognostic factors for the overall survival. These findings indicated that analysis for RCAS1 expression can provide crucial information about the clinical behaviour of uterine endometrial cancer, which may be valuable for the management of patients with this disease.

Adult↗
PubMed2003

Phase diagram of La2-xSrxCuO4 probed in the infared: imprints of charge stripe excitations.

While there is increasing evidence for antiferromagnetic (AF) ordering in the Cu-O planes of high-T(c) superconductors, either static or fluctuating, there is no direct evidence so far for the charge stripes that should separate the AF domains. By investigating the optical response of La2-xSrxCuO4 for 0<or=x<or=0.26 and 30<or=T<or=295 K, we identify strong far infrared peaks whose energy, width, and intensity are consistent with a scenario of charge stripe dynamics in the Cu-O planes.

Journal Article↗
PubMed2003

Measurement of positron production efficiency from a tungsten monocrystalline target using 4- and 8-GeV electrons.

Intense positron sources are being widely investigated for the next-generation linear colliders and B factories. A new method utilizing an axially oriented crystal as a positron-production target is one of the bright schemes, since it provides a powerful photon source through channeling and coherent bremsstrahlung processes when high-energy electrons penetrate the target. A series of positron-production experiments with tungsten crystals hit by 4- and 8-GeV single-bunch electron beams were carried out at the KEKB 8-GeV injector linac. Three tungsten crystals with different thicknesses (2.2, 5.3, and 9.0 mm) and those combined with amorphous tungsten plates were tested on a precise goniometer. The positron-production yields were measured with a magnetic spectrometer in the positron momentum (P(e(+))) range from 5 to 20 MeV/c. The angle of the <111> crystal axis with respect to the electron-beam direction was controlled by measuring the relative intensities of the produced positrons as a function of the rotational angle of the goniometer. The results show that the enhancements of the positron yield from crystal targets compared to amorphous targets of the same thickness at P(e(+))=20 MeV/c are from 1.5 to 3.7 and from 1.8 to 5.1, depending upon the target thickness for 4- and 8-GeV electrons, respectively.

Journal Article↗