Biomedical subjects

Nobuko Watanabe

Publications and source records attributed to Nobuko Watanabe.

8 recordsLinked to original sources

PubMed2006

Entomogenous fungi that produce 2,6-pyridine dicarboxylic acid (dipicolinic acid).

An inhibitor of the prophenoloxidase activation using extract from a silkworm pupa was isolated from a culture filtrate of Cordyceps militaris and identified as dipicolinic acid (DPA). The production of DPA in Clavicipitaceae fungi was examined. Entomogenous fungi that produce DPA were integrated into one group by a phylogenetic analysis based on 18S rDNA. It is suggested that the group acquired an ability to produce DPA during its evolution from plant pathogenic fungi to entomogenous fungi.

Animals↗

PubMed2004

Chemiluminescence in molecular recognition: base-induced decomposition of optically active dioxetanes bearing a bisnaphthol moiety with a complex of optically active crown ether-potassium tert-butoxide.

Four optically pure isomers of dioxetane (1) were decomposed by the action of the complex of an optically active crown ether with potassium tert-butoxide to afford light with lambda(max)CL and gave four different spectrum shapes.

Butanols↗

PubMed2004

Reversible 1,4-cycloaddition of singlet oxygen to N-substituted 2-pyridones: 1,4-endoperoxide as a versatile chemical source of singlet oxygen.

N-substituted pyridones (1) easily undergo singlet oxygenation to give exclusively the corresponding endoperoxides (2), which decompose to give pyridones again while liberating 1O2 in high yield.

Journal Article↗

PubMed2003

Fluoride-induced chemiluminescent decomposition of 1,2-dioxetanes bearing a phenyl moiety substituted with a methyl having an electron-withdrawing group.

A new type of dioxetane bearing a 3-(cyanomethyl)phenyl (1a), 3-(methoxycarbonylmethyl)phenyl (1b), 3-(benzoylmethyl)phenyl (1c), or 3-[cyano(methoxycarbonyl)methyl]phenyl group (1d) decomposed through an intermediary dioxetane bearing a benzylic carbanion to afford crimson to yellow light on treatment with TBAF in DMSO.

Journal Article↗

PubMed2003

[Quantification of urinary hemoglobin by an immunological method].

The quantification method of urinary hemoglobin has not been established. We examined whether a reagent (Eiken, Tokyo) used to immunologically assay fecal hemoglobin could be utilized to quantify urinary hemoglobin. The coefficients of variation were 2.2-3.0% in the reproducibility of one-run assays using urine and 4.3-5.7% in that of multiple-run assays using the standard sample of hemoglobin. Urinary hemoglobin was unstable and decreased in a time- and temperature-dependent manner. However, addition of the hemoglobin stabilization buffer (50 mM phosphate buffer, pH 6.4) (Eiken) to urine made urinary hemoglobin stable. Urinary hemoglobin levels did not change significantly when stored at 4 degrees C for 7 days or at -80 degrees C for 30 days. The hemoglobin concentration (mean +/- SD) of urine showing 1+, 2+ and 3+ with a test strip was 385 +/- 165(n = 30), 1070 +/- 499(n = 40) and 4130 +/- 2770 ng/ml (n = 20), respectively. Urinary hemoglobin did not correlate with urinary albumin, transferrin, immunoglobulin G, N-acetyl-beta-D-glucosaminidase nor alpha 1 microglobulin. These results suggest that this immunological method using the hemoglobin stabilization buffer can be utilized for quantification of urinary hemoglobin, which may provide clinically important information.

Biomarkers↗

PubMed2002

Measurement of lateral loads exerted on the maxillofacial region by habitual postures.

Lateral loads exerted on the maxillofacial region by habitual postures and habits may cause lateral shift or deformity of the mandible. These loads were measured with a desktop dynamic-strain gauge (DPM-600, Kyowa Co.) connected to a small, highly sensitive pressure sensor (PSL-A type, Kyowa Co.), and recorded with an oscillographic recorder (RDM-100A, Kyowa Co.). Measurements were taken with a pressure sensor embedded in silicone impression material placed in a vinyl chloride resin bag, on which pressures were applied. A preliminary study was conducted to obtain a proportional constant and a conversion formula for load calculation. The subsequent main study included 20 healthy male volunteers for load measurement in 12 positions. The mean load exerted on the mandible was 43.7 N when the subjects lay face down and approximately 20 N when they sat resting the lateral part of the chin on the hand, indicating that these loads are greater than regular orthodontic forces.

Adult↗

PubMedDate not supplied

Synthesis of 5-tert-butyl-1-(3-tert-butyldimethylsiloxy)phenyl-4,4-dimethyl-2,6,7-trioxabicyclo[3.2.0]heptanes and their fluoride-induced chemiluminescent decomposition: effect of a phenolic electron donor on the CIEEL decay rate in aprotic polar solvent.

Four bicyclic dioxetanes bearing a phenolic substituent, 3-tert-butyldimethylsiloxy-4-chlorophenyl (3a), 5-tert-butyldimethylsiloxy-4-chloro-2-ethylphenyl (3b), 5-tert-butyldimethylsiloxy-2-ethylphenyl (3c), and 3-tert-butyldimethylsiloxy-4-ethylphenyl (3d), were synthesized. All dioxetanes 3a-3d gave intense blue light on treatment with tetrabutylammonium fluoride (TBAF) in DMSO or acetonitrile. Kinetic study on the fluoride-induced CIEEL decay of these dioxetanes 3a-3d and the parent dioxetane 2b revealed that the para-substitution with chlorine on the phenolic moiety of dioxetane increases free energy of activation (DeltaG++), while the para-substitution with ethyl on the aryl decreases DeltaG++. On the other hand, substitution with an ethyl at the ortho-position instead of the para-position was found to increase DeltaG++ and to suppress the CIEEL decay. This fact is attributed to the steric factor of the ortho-ethyl group which would prevent the aromatic ring from rotating freely around the axis joined to the peroxide ring, and supports the suggestion for a CIEEL-active dioxetane bearing a phenolic moiety that an intramolecular electron transfer occurs preferentially from the phenolic donor to O-O of the dioxetane ring, when the aromatic ring lies in a certain conformation(s).

Electrons↗

PubMedDate not supplied

Bicyclic dioxetanes bearing an inden-2-yl or a benzo(b)thiazol-2-yl moiety as a CIEEL-active chemiluminescent substrate emitting red light.

Bicyclic dioxetanes bearing 5-(t-butyldimethylsiloxy)inden-2-yl, 3, or 5-(t-butyldimethylsiloxy)benzo(b)thiazol-2-yl, 4, were synthesized. On treatment with large excess of tetrabutylammonium fluoride in DMSO, dioxetane, 3, decomposed rapidly with accompanying emission of red (vermilion) light (lambda(max) (CL) = 637 nm). Comparing the chemiluminescent properties for 3 with those for related dioxetane, 1, in which pi-conjugation system is not fixed in plane, both CIEEL-decay rate and chemiluminescent efficiency were found to be improved for 3. Chemiluminescent decomposition of dioxetane, 4, was similarly induced to emit crimson light (lambda(max) (CL) = 725 nm), though the chemiluminescent efficiency was low.

Benzothiazoles↗