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Biomedical subjects

H Tsuchiya

Publications and source records attributed to H Tsuchiya.

At least 289 records · Page 16Linked to original sources

Sensitive high-performance liquid chromatographic method for prostaglandins using a fluorescence reagent, 4-bromomethyl-7-acetoxycoumarin.

High-performance liquid chromatography of prostaglandins is developed in which a fluorescence reagent, 4-bromomethyl-7-acetoxycoumarin is used to perform the high-sensitivity detection. The reagent reacts with prostaglandins and related compounds to form the ester derivatives, which are separated using a reversed-phase system. Each labeled compound eluted from the column is successively hydrolyzed to the fluorescent coumarin derivative, and this fluorophore is introduced into a flow-through fluorometer. Prostaglandins can be determined in the range of at least 1 nmol to 5 pmol, and the detection limit is about 10 fmol. This system is applied to the analysis of prostaglandins in human seminal fluid.

Chromatography, High Pressure Liquid↗

[Anti-allergic actions of traditional oriental medicine--actions against types I and IV hypersensitivity reactions].

A study was carried out to examine the effects of 23 kinds of crude drugs and 3 kinds of blended Chinese traditional medicines on Type I and Type IV allergic reactions. Forty eight-hr homologous PCA in rats as a typical model of the Type I reaction using anti-dinitrophenylated ascaris . IgE serum was significantly inhibited by the oral administration of the following drugs: Aqueous extracts: Aurantii F.i., Bupleuri R., Schizandrae F., Scutellariae R., Zizyphi F., and Shohsaiko-to and Methanolic extracts: Asiasari R., Aurantii F.i., Bupleuri R., Ginseng R., Glycyrrhizae R., Magnoliae C., Schizandrae F. and Trichosanthis S., Contact dermatitis in mice as a model of the Type IV reaction caused by picryl chloride was significantly inhibited by the oral application of aqueous extracts of Ginseng R. and Magnoliae C. as well as the powder of Hoelen. The aqueous extract of Saiboku-to also showed an inhibition of the contact dermatitis, and it significantly potentiated the inhibition of contact dermatitis by prednisolone.

Animals↗

Three-dimensional structure of Tomes' processes and enamel prism formation in the kitten.

The Tomes' processes of ameloblasts in the kitten were examined with both transmission and scanning electron microscopes and their three-dimensional structure demonstrated. In general, Tomes' process can be envisaged as the upper part of a diagonally cut column. It was established that the flat crescent face of the process which is slanted cervically, it is the secretory surface (S-face) and the curved crescent surface which is cuspally directed, is the nonsecretory surface (N-face). The cervical border of the S-face is confluent with the free apical surfaces of cervically adjacent ameloblasts. Only the S-face and the adjoining small part of the next ameloblasts produce enamel and arrange crystallites into prisms as evidenced by the perpendicular orientation of crystallites to the S-face of Tomes' process and the free ameloblast surface. Crystallite arrangement within prisms and prism arrangement within enamel are determined by the three-dimensional morphology of the Tomes' processes. The processes are schematically represented and their relationship to other ultrastructural features as seen in sections is discussed.

Ameloblasts↗

Preparation and biological activities of 10-decarbamoyloxy-9-dehydromitomycin B and its analogs.

A new naturally occurring mitomycin, 10-decarbamoyloxy-9-dehydromitomycin B (1), was prepared by treating mitomycin B with sodium hydride. Its analogs having an exo-cyclic double bond in their structure were also synthesized. These compounds showed antibacterial and cytotoxic activities. Among them, 7-amino-10-decarbamoyloxy-9-dehydro-7-demethoxymitomycin B (2) was the most potent growth inhibitor of KB cells in vitro and, accordingly, it appears to be a potential antitumor agent.

Antibiotics, Antineoplastic↗

Rapid determination of glycine- and taurine-conjugated bile acids in human bile by high-performance liquid chromatography.

With use of an anion-exchange packing, TSK Gel IEX 540 DEAE, for high-performance liquid column chromatography, glycine- and taurine-conjugated bile acids were separated in 10 min and detected with a differential refractometer. Human bile could be analyzed after a simple pretreatment. The purity of the peaks of glycine- and taurine-conjugated bile acids in human bile was confirmed by enzymatic determinations using 3 alpha-hydroxysteroid:NAD oxidoreductase. The molar ratios of the two forms of the conjugates (glycine/taurine ratios) in bile from normal subjects and from patients suffering from various hepatobiliary diseases were measured.

Bile↗

Acute right-sided hemorrhagic colitis associated with oral administration of ampicillin.

Among 56 cases who presented to Kanto-Teishin Hospital complaining of bloody diarrhea or considerable hematochezia of acute onset, 8 cases (14.3%) were considered due to colitis associated with oral ampicillin therapy. The bloody diarrhea, often with abdominal cramps, began 2-7 days after starting the treatment. The dosage of ampicillin taken ranged from 2.0 to 4.5 g. Early total colonoscopy and biopsy revealed marked mucosal hemorrhage with minimal or no inflammatory changes mainly in the right colon. Rectum and sigmoid colon are completely normal except in one case. Symptoms rapidly resolved after the endoscopy. At follow-up colonoscopy, performed 4-12 days later, the mucosal changes had cleared completely. There was no evidence to support a hypersensitivity reaction of the colonic mucosa to ampicillin. We believe that right-sided hemorrhagic colitis is one of the common forms of colitis associated with ampicillin. Its differentiation from other kinds of acute colitis and the importance of early total colonoscopy are discussed.

Administration, Oral↗

Effects of estrogen on the lymphoid regeneration and immune response in irradiated and marrow-reconstituted mice.

Various doses of estriol (E3) were given to mice intraperitoneally, immediately after lethal irradiation and marrow reconstitution. The assessment of the plaque-forming cell (PFC) response to sheep erythrocytes in the spleen and the histological assessment of lymphoid tissues were carried out 30 days later. The effects appeared to be dose-dependent and resulted in a marked suppression of the PFC response. The depletion of lymphocytes was dramatic and dose-dependent in the thymus, and in the thymus-dependent and in the thymus independent areas of the peripheral lymphoid tissues. These results suggest that E3 acts on the differentiation of stem or precursor cells toweard both the populations of T and B lymphocytes. Although E3, given on day 7 after irradiation and marrow reconstitution, suppressed the lymphoid regeneration and PFC response markedly, E3 given on day 14 had no effect. On day 7 the majority of regenerating lymphoid tissues were large pyroninophilic cells and on day 14, small lymphocytes. These results suggest that the precursor or immature lymphocytes are sensitive to E3, while mature lymphocytes are resistant. Lymphoid regeneration and PFC response were retarded in mice irradiated and reconstituted with bone marrow cells from donors pretreated with E3. These results suggest that E3 acts on the stem or precursor cells capable to differentiate in the direction of lymphoid populations and reduce their number in the bone marrow.

Animals↗