PubMed Health⌕ Search

Biomedical subjects

M Taniguchi

Publications and source records attributed to M Taniguchi.

At least 37 records · Page 2Linked to original sources
PubMed2005

Involvement of eicosanoids and surfactant protein D in extrinsic allergic alveolitis.

The pathophysiology of extrinsic allergic alveolitis (EAA) involves oxidative lung damage as well as interstitial and alveolar inflammation. Macrophages and mast cells are inflammatory components of EAA that produce both leukotrienes (LTs) and prostaglandin D2 (PGD2). In addition, PGD2 is also produced by the free-radical-catalysed peroxidation of arachidonic acid during oxidative stress. Urinary 8-iso prostaglandin F2alpha (8-isoPGF2alpha) and serum surfactant protein D (SP-D) are considered appropriate biomarkers of oxidative stress and interstitial lung disease activity, respectively. The present study aimed to assess the association of these biomarkers with the pathophysiology of EAA. Two cases of acute EAA caused by the inhalation of fungi spores were reported. Eight asthmatic patients and six healthy control subjects were also enrolled in the current study. The serum SP-D and urinary eicosanoid (LTE4, PGD2 metabolite (9alpha,11betaPGF2), 8-isoPGF2alpha) concentrations markedly increased during the acute exacerbation phase. These concentrations decreased following corticosteroid therapy in the EAA patients. There was a significant correlation between serum SP-D and urinary 9alpha,11betaPGF2 concentrations in the EAA patients. In conclusion, although the present study proposes that serum surfactant protein-D and urinary eicosanoids are new biomarkers involved in the various immunological responses in extrinsic allergic alveolitis, further large-scale studies are needed to investigate the role of these compounds, not just as biomarkers, but also as biological potentiators of extrinsic allergic alveolitis.

Adult↗
PubMed2005

Interferon-beta induction/interferon-alpha2b plus ribavirin therapy in patients with chronic hepatitis C.

Treatment of chronic hepatitis C virus (HCV) infection with interferon (IFN) and ribavirin improves the rate of eradication of the virus by less than 20% in patients with genotype 1b and a high viral load. In this study we assessed whether IFN-beta induction/IFN-alpha2b plus ribavirin enhances the efficacy of the therapy in patients with chronic hepatitis C. The efficacy of IFN-beta induction/IFN-alpha2b plus ribavirin therapy (group A, n=7) was compared with that of IFN-alpha2b plus ribavirin (group B, n=7) in 14 patients with high levels of HCV-RNA (> 100 K/U/ml). No significant differences were observed in the clearance of HCV-RNA between the two groups (A and B, respectively) 2 weeks after the start of the treatment (0% and 14.3%), at the end of the treatment (71.4% and 100%) and 6 months after the end of the treatment (28.6% and 14.3%). Recovery was complete in 28.6% and 14.3%, transient in 42.9% and 85.7% and absent in 28.6% and 0% in groups A and B, respectively. Early log changes in the viral load from the baseline after 2 weeks of treatment were 2.41 +/- 0.91 and 2.77 +/- 0.20 in groups A and B, respectively, with no significant difference between the two groups. In the present study, we were not able to demonstrate that IFN-beta induction/IFN-alpha2b plus ribavirin therapy was superior to IFN-alpha2b plus ribavirin therapy in patients with genotype 1b and high viral loads.

Adult↗
PubMed2005

Fukutin and alpha-dystroglycanopathies.

Fukuyama-type congenital muscular dystrophy (FCMD), Walker-Warburg syndrome (WWS), and muscle-eye-brain (MEB) disease are clinically similar autosomal recessive disorders characterized by congenital muscular dystrophy, lissencephaly, and eye anomalies. We identified the gene for FCMD and MEB, which encodes the fukutin protein and the protein O-linked mannose beta1, 2-N-acetylglucosaminyltransferase (POMGnT1), respectively. Recent studies have revealed that posttranslational modification of alpha-dystroglycan is associated with these congenital muscular dystrophies with brain malformations. All are characterized by hypoglycosylated alpha-dystroglycan. Fukutin's function and the relation with other alpha-dystroglycanopathies are discussed.

Animals↗
PubMed2004

Determination of the orbital polarization in YTiO3 by using soft X-ray linear dichroism.

We report measurements of linear dichroism in x-ray absorption at Ti L(2,3) edges of a Mott-insulating ferromagnet YTiO3, where orbital ordering occurs in the triply degenerate Ti 3d t(2g) states. Dichroic spectra and their integrated intensities are obtained for the incident electric field with polarizations parallel to a, b, and c axes. The comparison of the spectra with atomic multiplet calculations removes the ambiguity about the orbital polarization, i.e., the relative weights of |xy>, |yz>, and |zx> orbits, which are crucial for the origin of ferromagnetism. The result is consistent with the previous analysis of nuclear magnetic resonance in the Mizokawa-Fujimori scheme.

Journal Article↗
PubMed2004

Nature of the well screened state in hard X-ray Mn 2p core-level photoemission measurements of La1-xSrxMnO3 films.

Using hard x-ray (HX; hnu=5.95 keV) synchrotron photoemission spectroscopy (PES), we study the intrinsic electronic structure of La(1-x)Sr(x)MnO(3) (LSMO) thin films. Comparison of Mn 2p core-levels with soft x-ray (SX; hnu approximately 1000 eV) PES shows a clear additional well-screened feature only in HX PES. Takeoff-angle dependent data indicate its bulk (> or =20 A) character. The doping and temperature dependence track the ferromagnetism and metallicity of the LSMO series. Cluster model calculations including charge transfer from doping-induced states show good agreement, confirming this picture of bulk properties reflected in Mn 2p core-levels using HX PES.

Journal Article↗
PubMed2004

Kink in the dispersion of layered strontium ruthenates.

We present detailed energy dispersions near the Fermi level along the high symmetry line GammaX on the monolayer and bilayer strontium ruthenates Sr2RuO4 and Sr3Ru2O7, determined by high-resolution angle-resolved photoemission spectroscopy. A kink in the dispersion is clearly shown for the both ruthenates. The energy position of the kink and the slope in the low-energy part near the Fermi level are almost identical between them, whereas the dispersion in the high-energy part varies, like the behavior of the kink for the cuprate superconductors.

Journal Article↗
PubMed2004

Electronic structure of bases in DNA duplexes characterized by resonant photoemission spectroscopy near the Fermi level.

The electronic structure of bases in DNA duplexes was investigated by resonant photoemission spectroscopy near the Fermi level, in order to specify charge migration mechanisms. We observed a kinetic energy shift of N-KLL Auger electrons and an intensity enhancement of valence electrons on the resonant photoemission spectra for both poly(dG).poly(dC) and poly(dA).poly(dT) DNAs. These directly show the localized unoccupied states of the bases. We conclude that the charge hopping model is pertinent for electric conduction in a DNA duplex, when electrons pass through the unoccupied states.

Biophysics↗
PubMed2004

Production of L-lactic acid from a mixture of xylose and glucose by co-cultivation of lactic acid bacteria.

The production of optically pure lactic acid in a high yield from xylose or a mixture of xylose and glucose, which is a model hydrolysate of lignocellulose, is described. In a single cultivation, Enterococcus casseliflavus produced 38 g/l of lactic acid with an optical purity of 96% enantiomeric excess (ee) and 6.4 g/l of acetic acid from 50 g/l of xylose when MRS medium was used. When a mixture of 50 g/l of xylose and 100 g/l of glucose was used as the carbon source in a cultivation of E. casseliflavus alone, glucose was converted to lactic acid in the early phase of the cultivation but xylose was hardly consumed. In a co-cultivation where E. casseliflavus and Lactobacillus casei specific for glucose were simultaneously inoculated, little or no lactic acid was produced after the glucose was almost consumed. A co-cultivation with two-stage inoculation (in which E. casseliflavus was added at a cultivation time of 40 h after L. casei cells were inoculated) resulted in complete consumption of 50 g/l of xylose and 100 g/l of glucose. In the co-cultivation, 95 g/l of lactic acid with a high optical purity of 96% ee was obtained at 192 h. Such a co-cultivation using two microorganisms specific for each sugar is considered to be one promising cultivation technique for the efficient production of lactic acid from a sugar mixture derived from lignocellulose.

Coculture Techniques↗
PubMed2004

Molecular paramagnetic semiconductor: crystal structures and magnetic and conducting properties of the Ni(dmit)(2) salts of 6-oxoverdazyl radical cations (dmit = 1,3-dithiol-2-thione-4,5-dithiolate).

Four kinds of 1:1 and 1:3 salts of 3-[4-(trimethylammonio)phenyl]-1,5-diphenyl-6-oxoverdazyl radical cation ([1](+)) and its mono- and dimethyl derivatives ([2](+) and [3](+)) with Ni(dmit)(2) anions (dmit = 1,3-dithiol-2-thione-4,5-dithiolate) ([1](+)[Ni(dmit)(2)](-) (4), [2](+)[Ni(dmit)(2)](-) (5), [3](+)[Ni(dmit)(2)](-) (6), and [1](+)[Ni(dmit)(2)](3)(-) (7)) have been prepared, and the magnetic susceptibilities (chi(M)) have been measured between 1.8 and 300 K. The chi(M) values of salts 5 and 7 can be well reproduced by the sum of the contributions from (i). a Curie-Weiss system with a Curie constant of 0.376 (K emu)/mol and negative Weiss constants (THETAV;) of -0.4 and -1.7 K and (ii). a dimer system with strong negative exchange interactions of 2J/k(B) = -354 and -258 K, respectively. The dimer formations in Ni(dmit)(2) anions have been ascertained by the crystal structure analyses of salts 4-6. In salts 4 and 6, Ni(dmit)(2) dimer molecules are sandwiched between two verdazyl cations, indicating the formation of a linear tetramer in 4 and 6. The magnetic susceptibility data for salts 4 and 6 have been fitted to a linear tetramer model using an end exchange interaction of 2J(1)/k(B) = -600 K and a central interaction of 2J(2)/k(B) = -280 K for 4 and 2J(1)/k(B) = -30 K and 2J(2)/k(B) = -580 K for 6, respectively. The results of the temperature dependence of the g(T) value in salts 4-6 obtained by ESR measurement also support the above analyses. The 1:1 salts 4-6 are insulators. On the other hand, the conductivity of the 1:3 salt 7 at 20 degrees C was sigma = 0.10 S cm(-)(1) with an activation energy E(A) = 0.099 eV, showing the semiconductor property. Salt 7 is a new molecular paramagnetic semiconductor.

Journal Article↗
PubMed2004

Chronic inhalation toxicity and carcinogenicity study on potassium octatitanate fibers (TISMO) in rats.

A chronic inhalation toxicity/carcinogenicity study of potassium octatitanate fibers (TISMO) was conducted in male Fischer 344 rats. Groups of 135 rats were exposed via whole-body inhalation to 0, 20, 60, or 200 WHO fibers/cc of TISMO, 6 h/day, 5 days/w for 24 mo. Six of 30 subgroup rats were killed after 3, 6, 12, 18, and 24 mo of exposure for lung burden evaluations. Another 30 subgroup rats were removed from the exposure chambers after 6 mo of exposure, placed in clean air, and from this group 6 rats were killed at 3, 6, 9, 12, and 18 mo later to study lung clearance. The remaining 75 rats in each group were subjected to 24 mo of exposure for chronic toxicity and carcinogenicity study. Rats exposed to HEPA-filtered air (chamber control) were used as a negative control in each study. The lung burden results indicated that a time point of equilibrium between lung burden and lung clearance at 20 WHO fibers/cc exposure was attained after approximately 18 mo of exposure. There was no difference in the number of WHO fiber from the lungs between 18 and 24 mo at 20 WHO fibers/cc exposure. But disproportional rapid increase in lung burden at 200 WHO fibers/cc exposure appeared to be saturation of lung clearance mechanism resulting from lung overloading. At 200 WHO fibers/cc exposure, approximately 22.9 and 70.5 million WHO fibers were retained in the lung after 3 and 6 mo of exposure, respectively, but lungs revealed normal in appearance. However, alveolar walls enclosing aggregated TISMO-laden alveolar macrophages (AMs) showed fibrotic thickening and approximately 197.3 million WHO fibers were retained in the lungs after 18 mo of exposure. Inhaled fibers were rapidly cleared during 3- and 6-mo recovery periods, and thereafter gradually progressive fiber reduction was observed throughout 18 mo of recovery. The number of WHO fibers decreased by approximately 72%, 74%, and 79% in the 200, 60, and 20 WHO fibers/cc groups, respectively, at the end of the 18-mo recovery period following 6 mo of exposure. Although inhaled TISMO fibers in the 20 WHO fibers/cc exposure group were phagocytized by alveolar macrophages (AMs) the lung morphology appeared normal throughout 24 mo of exposure. At 60 WHO fibers/cc exposure, a slight dose- and time-dependent increase in TISMO-laden AMs was observed throughout 3, 6, and 12 mo of exposure and some alveoli containing aggregated TISMO-laden AMs showed alveolar wall thickening at 18 mo of exposure and minimal alveolar fibrosis at 24 mo of exposure. The exposure concentration is interpreted as a borderline effect level. At 200 WHO fibers/cc exposure, lungs preserved normal architecture at 3 and 6 mo of exposure. Some alveolar walls enclosing aggregates of TISMO-laden AMs were slightly thickened after 12 mo of exposure and revealed slight alveolar fibrosis after 18 and 24 mo of exposure. Neither exposure related-pulmonary neoplasm nor mesothelioma was observed in 24 mo of exposure. The 20 WHO fibers/cc exposure concentration is considered to be a no-observable-adverse-effect level (NOAEL). TISMO exposure limits of 1 WHO fiber/cc would not impose a significant health hazard to humans in the workplace based on the animal experiments and medical surveys on workers.

Administration, Inhalation↗
PubMed2004

Urinary 3-bromotyrosine and 3-chlorotyrosine concentrations in asthmatic patients: lack of increase in 3-bromotyrosine concentration in urine and plasma proteins in aspirin-induced asthma after intravenous aspirin challenge.

BACKGROUND: Eosinophil peroxidase and myeloperoxidase halogenate tyrosine residues in plasma proteins and generate 3-bromotyrosine (BY) and 3-chlorotyrosine (CY), respectively. OBJECTIVES: (1) To estimate urinary concentrations of BY and CY in asthmatic patients. (2) To investigate BY concentration in relation to urinary leukotriene E4 (LTE4) concentration in order to evaluate the activation of eosinophils in patients with aspirin-induced asthma (AIA). METHODS: BY and CY were quantified with a gas chromatograph-mass spectrometer using (13)C-labelled compounds as internal standards. RESULTS: (1) Activation of eosinophils and neutrophils by immobilized IgG1 induced preferential formation of BY and CY, respectively. (2) A significantly higher concentration of BY was observed in the urine from asthmatic patients than in that from healthy control subjects (45+/-21.7 vs. 22.6+/-10.8 ng/mg-creatinine, P<0.01). CY concentration was also elevated in the urine from asthmatic patients (4.4+/-3.2 vs. 1.5+/-1.0 ng/mg-creatinine, P<0.01). (3) After intravenous aspirin challenge of aspirin-induced asthmatic patients, the concentration of BY in urine did not significantly change. No significant change was also observed in the ratio of BY concentration to total tyrosine concentration in plasma proteins. In contrast, the concentration of urinary LTE4 significantly increased after the intravenous aspirin challenge. CONCLUSION: Determination of BY and CY concentrations may be useful for monitoring the activation of eosinophils and neutrophils in asthmatic patients, respectively. After aspirin challenge of AIA patients, the increased concentration of urinary LTE4 did not accompany changes in BY concentration in both urine and plasma proteins. These results may preclude the activation of eosinophils after aspirin challenge in patients with AIA.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2004

Increase in urinary leukotriene B4 glucuronide concentration in patients with aspirin-intolerant asthma after intravenous aspirin challenge.

BACKGROUND: Aspirin challenge of aspirin-intolerant asthma (AIA) patients causes a significant increase in leukotriene E4 (LTE4) concentration in urine. However, knowledge on leukotriene B4 (LTB4) generation in patients with AIA is insufficient. Recent research has demonstrated that exogenously administered LTB4 is excreted as glucuronide into the urine in human healthy subjects. OBJECTIVE: The purpose of this study is to estimate urinary LTB4 glucuronide (LTBG) concentration in the clinically stable condition in healthy subjects and asthmatic patients and to investigate changes in urinary LTBG concentration in patients with AIA after aspirin challenge. METHODS: A provocation test was performed by intravenous aspirin challenge. After urine was hydrolysed by beta-glucuronidase, the fraction containing LTB4 was purified by high-performance liquid chromatography and LTB4 concentration was quantified by enzyme immunoassay. Urinary LTBG concentration was calculated as the difference between the concentration obtained with hydrolysis and that without hydrolysis. RESULTS: (1) After hydrolysis, the presence of urinary LTB4 was verified by gas chromatography-mass spectrometry-selected ion monitoring. (2) The urinary LTBG concentration was significantly higher in the asthmatic patients than in the healthy subjects (median, 5.37 pg/mg creatinine [range 1.2-13] vs. 3.32 pg/mg creatinine [range, 0.14-10.5], P = 0.0159). (3) The patients with AIA (n = 7), but not those with aspirin-tolerant asthma (n = 6), showed significant increases in LTBG and LTE4 excretions after aspirin challenge. (4) When the concentrations after aspirin challenge were analysed simultaneously, a significant linear correlation was observed between urinary LTBG concentration and urinary LTE4 concentration in patients with AIA (Spearman's rank correlation test, r = 0.817, P = 0.0003). CONCLUSION: LTBG is present in human urine, albeit at a concentration lower than urinary LTE4. In addition to a marked increase in cysteinyl-leukotriene production, aspirin challenge induced LTB4 production in AIA patients.

Adult↗
PubMed2004

Cerebral motor control in patients with gliomas around the central sulcus studied with spatially filtered magnetoencephalography.

OBJECTIVE: Application of spatially filtered magnetoencephalography (MEG) to investigate changes in the mechanism of cerebral motor control in patients with tumours around the central sulcus. METHODS: MEG records were made during a repetitive hand grasping task in six patients with gliomas around the central sulcus and in four control subjects. Power decreases in the alpha (8-13 Hz), beta (13-30 Hz), and low gamma bands (30-50 Hz) during the motor tasks (event related desynchronisation, ERD) were analysed statistically with synthetic aperture magnetometry. The tomography of ERD was superimposed on the individual's magnetic resonance image. RESULTS: beta ERD was consistently localised to the contralateral primary sensorimotor cortex (MI/SI) in control subjects, whereas the alpha and low gamma ERD showed considerable intersubject variability. beta ERD in patients during non-affected side hand movement was also localised to the contralateral MI/SI, but exclusively to the ipsilateral hemisphere during affected side hand movement. CONCLUSIONS: The altered pattern of ERD in the patient group during affected side hand movement suggests recruitment of diverse motor areas, especially the ipsilateral MI/SI, which may be required for the effective movement of the affected hand.

Adult↗
PubMed2003

Src family kinase inhibitor PP1 improves motor function by reducing edema after spinal cord contusion in rats.

Following spinal cord injury vascular permeability increases around the area of injury, which possibly leads to secondary tissue damage. Vascular endothelial growth factor (VEGF) and Src which exists downstream of VEGF may contribute to edema formation. We here report that the Src family kinase inhibitor PPI could reduce edema and the inflammatory response after spinal cord injury. In this study we have examined the effect of PPI on motor function after mild spinal cord compression injury. We utilized a mild spinal cord compression model in rats. PPI or vehicle only was administered intraperitoneally after cord compression. The motor function of the hind limbs after injury was categorized into 7 grades. At 1, 3, 7 and 14 days after injury, the spinal cord was removed and the extent of edema formation and inflammation were examined using immunohistochemistry with an anti-IgG and anti-ED-1 antibody. The immunohistochemical analysis revealed that the area of edema formation and inflammation was remarkably reduced in animals with PPI. The muscle function was flaccid in both groups immediately after injury. However, at 3 and 8 days after injury, a significant improvement was observed in the PPI group. These results suggest that PPI is a strong candidate for drug treatment of spinal cord injury.

Animals↗
PubMed2003

Nasal blockage and urinary leukotriene E4 concentration in patients with seasonal allergic rhinitis.

BACKGROUND: Cysteinyl-leukotrienes have been reported to have a primary role in the induction of nasal blockage of allergic rhinitis. However, there has been little experimental evidence that substantiates the relationship between nasal blockage severity and urinary leukotriene E4 (U-LTE4) concentration in patients with seasonal allergic rhinitis (SAR). METHODS: The concentrations of urinary mediators in 20 SAR patients were measured using an enzyme immunoassay to determine the relationship between nasal blockage severity and U-LTE4 concentration in patients with SAR. RESULTS: The basal U-LTE4 concentration was significantly higher in SAR patients with severe nasal blockage than in those with mild nasal blockage and in healthy control subjects. Although U-LTE4 concentrationwas significantly higher in patients with both asthma and SAR than in SAR patients with mild nasal blockage, no significant difference in the U-LTE4 concentration between patients with both asthma and SAR and SAR patients with severe nasal blockage was found. There was a significant correlation between U-LTE4 and urinary 9alpha11beta-prostoglandin F2 (9alpha11betaPGF2) concentrations (rs = 0.51, P = 0.02) in SAR patients. CONCLUSIONS: Although specific sites and cells of cysteinyl-leukotriene biosynthesis could not be determined in this study, severe nasal blockage is associated with the increased excretion level of U-LTE4.

Adolescent↗
PubMed2003

Adenovirus-mediated overexpression of a gene prevents hearing loss and progressive inner hair cell loss after transient cochlear ischemia in gerbils.

The use of adenoviral vectors has recently provided a novel strategy for direct gene transfer into the cochlea. In this study, we assessed the utility of an adenoviral vector expressing glial-cell-derived neurotrophic factor (GDNF) in ischemia-reperfusion injury of the gerbil cochlea. The vector was injected through the round window 4 days before ischemic insult. The distribution of a reporter transgene was confirmed throughout the cochlea from the basal to the apical turn and Western blot analysis indicated significant upregulation of GDNF protein 11 days following virus inoculation. Hearing ability was assessed by sequentially recording compound action potentials (CAP), and the degree of hair cell loss in the organ of Corti was evaluated in specimens stained with rhodamine-phalloidin and Hoechst 33342. On the seventh day of ischemia, the CAP threshold shift and inner hair cell loss were remarkably suppressed in the Ad-GDNF group compared with the control group. These results suggest that adenovirus-mediated overexpression of GDNF is useful for protection against hair cell damage, which otherwise eventually occurs after transient ischemia of the cochlea.

Adenoviridae↗
PubMed2003

Disrupted-In-Schizophrenia 1, a candidate gene for schizophrenia, participates in neurite outgrowth.

Disrupted-In-Schizophrenia 1 (DISC1) was identified as a novel gene disrupted by a (1;11)(q42.1;q14.3) translocation that segregated with schizophrenia in a Scottish family. Predicted DISC1 product has no significant homology to other known proteins. Here, we demonstrated the existence of DISC1 protein and identified fasciculation and elongation protein zeta-1 (FEZ1) as an interacting partner of DISC1 by a yeast two-hybrid study. FEZ1 and its nematode homolog are reported to represent a new protein family involved in axonal outgrowth and fasciculation. In cultured hippocampal neurons, DISC1 and FEZ1 colocalized in growth cones. Interactions of these proteins were associated with F-actin. In the course of neuronal differentiation of PC12 cells, upregulation of DISC1/FEZ1 interaction was observed as along with enhanced extension of neurites by overexpression of DISC1. The present study shows that DISC1 participates in neurite outgrowth through its interaction with FEZ1. Recent studies have provided reliable evidence that schizophrenia is a neurodevelopmental disorder. As there is a high level of DISC1 expression in developing rat brain, dysfunction of DISC1 may confer susceptibility to psychiatric illnesses through abnormal development of the nervous system.

Actins↗