Kazuo Ogawa

Analysis of Trichophyton antigen-induced contact hypersensitivity in mouse

BACKGROUND Trichophyton-induced superficial skin mycosis is a common infectious human disease, but the immunological mechanism against Trichophyton infection is unclear with regard to many points. Since Trichophyton cannot colonize mice, guinea pigs were used in previous experiments on Trichophyton infection. However, it is difficult to perform immunological and genetic analyses in guinea pigs. OBJECTIVE The objective of this study was to establish a mouse Trichophytin-associated inflammation model of superficial skin mycosis in which immunological and genetic analyses can be performed. METHODS We established a mouse Trichophyton-induced contact hypersensitivity model by applying Trichophytin, the Trichophyton antigen, extracted from Trichophyton mentagrophytes, to mice. Using a Th1-dominant strain, C57BL/6, and a Th2-dominant strain, BALB/c, we investigated the expression of inflammatory cytokines and receptors of the innate immune system for fungi, TLR4, TLR2, and dectin-1, and their influences on responses of the acquired immune system. RESULTS In C57BL/6 mice, expressions of IFN-γ and IL-17 A in regional lymph nodes and IL-1β, IFN-γ, IL-6, and IL-23 in the inflammatory auricular skin were enhanced by Trichophytin challenge, suggesting that not only Th1 cells but also Th17 cells were induced. In BALB/c mice, expressions of IL-4 in regional lymph nodes, and TSLP and IL-4 in the auricular skin were enhanced by Trichophytin challenge. Interestingly, dectin-1-neutralizing antibody inhibited the promotion of IFN-γ production in C57BL/6 mice, and dectin-1-expressing immune cells had crucial actions in Trichophyton-induced IFN-γ production. CONCLUSION These results suggest that inflammatory mediators differently regulate Trichophytin-induced contact hypersensitivity on the basis of the status of host immunity.

Glycyrrhetinic acid inhibits contact hypersensitivity induced by trichophytin via dectin-1

Trichophyton infection is highly prevalent and tends to be recurrent. Therefore, it is important to develop new therapeutic agents. Previously, we established a mouse model of Trichophyton‐induced contact hypersensitivity (CHS) and demonstrated that dectin‐1 was involved in inflammation induced by trichophytin, the Trichophyton antigen. Here, we used that model to investigate glycyrrhetinic acid (GA) from plants of the genus Glycyrrhiza as a potential anti‐inflammatory agent against superficial mycoses. GA suppressed swelling and the expression of inflammatory cytokines, including macrophage inflammatory protein (MIP)‐2, interleukin (IL)‐6, tumor necrosis factor (TNF)‐α and interferon (IFN)‐γ mRNA. Anti‐MIP‐2 antibody suppressed trichophytin‐induced inflammation, and antidectin‐1 antibody suppressed zymosan‐induced MIP‐2 production in keratinocyte cells. These results suggest that MIP‐2 is produced by dectin‐1 activation and is involved in inflammation associated with CHS to trichophytin. GA also suppressed zymosan‐induced MIP‐2 and interleukin (IL)‐8, production in mouse and human macrophages and keratinocytes. Furthermore, GA suppressed the phosphorylation of spleen tyrosine kinase (Syk) and inhibitor of nuclear factor‐kappa B (IκBα) and the degradation of IκBα in zymosan‐simulated RAW264.7 cells. The results of this study suggest that GA suppresses inflammation induced by trichophytin, partly by the downregulation of Syk phosphorylation.

Synthesis of 3,9-dialkylguanines and their conversion into 3-alkylwyes, models for the fluorescent nucleosides from phenylalanine transfer ribonucleic acids

Abstract Synthesis of 3,9-dialkylguanines 5 has been accomplished by N-cyanation of 1-alkyl-5-(alkylamino)imidazole-4- carboxamides 3 followed by base-catalysed cyclisation. Cyclocondensation of 9-alkyl-3-methylguanines 5a, d, f with MeCOCH2Br gave 3-alkylwyes 6, model compounds of the most probable structure for wyosine from Torulopsis utilis tRNAPhe.

Syntheses of the 7-N-Oxides of 6-Mercaptopurine and 6-Methylthiopurine

6-Mercaptopurine 7-N-oxide (6) has been synthesized for the first time from 4,6-dichloro-5-nitropyrimidine (12) by following a «phenacylamine route» through the intermediates (8) and (9). Methylation of (9) and removal of the p-methoxybenzyl group provided 6-methylthiopurine 7-N- oxide (7)

Thermophile-fermented compost extract as a possible feed additive to enhance fecundity in the laying hen and pig: Modulation of gut metabolism.

Recently, we reported that the oral administration of an extract of compost fermented with marine animal resources and thermophilic Bacillus species should confer health benefits in fish, pigs and rodents. Herein, the relations between fecundity and gut metabolites in laying hens and pigs on farms after oral exposure to compost were investigated. On the hen farms, the egg production of hens continuously administered the extract was maintained at significantly higher levels compared with the hens not administered the extract. On the swine farms, after the compost treatment, the shipping dates of fattening pigs were shortened, with an improvement in the death rate of the pigs. When the levels of fecal organic acids, such as short-chain fatty acids, lactate, and ammonium, as indicators of gut metabolism and energy sources for peripheral tissues, were examined, the levels of the acetate, propionate, and butyrate in the feces of the hens and pigs in the compost-treated group were not always different from those in the untreated control group. However, the levels of lactate were consistently low in the feces of both animals after the compost treatment. The fecal ammonium concentrations in old hens (age 597-672 days) and 2-month-old piglets from the compost-fed mother sows were low when compared with the untreated groups. The concentrations of free organic acids and their related compounds in the animal products (eggs and pig loins) were nearly equal to those in the untreated control products. Thus, the oral administration of the thermophile-fermented compost should improve the fecundity of hens and pigs by modifying their gut metabolism.

Syntheses of the N(1)- and N(3)-oxides of 7-benzyladenine

Oxidation of 7-benzyladenine (9) with m-chloroperoxy-benzoic acid in MeOH has been found to yield 7-benzyladenine 1-oxide (11) as the main product. Alternatively, the same N-oxide (11) has been synthesized in 81% yield from 1-benzyl-4-(ethoxymethyleneamino)imidazole-5-carbonitrile (12) and hydroxylamine. Treatment of 1-benzyl-4-(hydroxyamino)imida- zole-5-carbonitrile (17), prepared in 63% yield from the corresponding 4-nitro derivative (13) by catalytic reduction (Pt/H 2 ), with formamidine acetate in boiling EtOH gave 7-benzyladenine 3-oxide (16) in 83% yield

Synthesis of adenine 7-oxide from adenine: utilization of a benzyl group as a control synthon at the 3-position

The first unequivocal synthetic route to adenine 7-oxide (7) has been established. The route started with peroxycarboxylic acid oxidation of 3-benzyladenine (5), readily obtainable from adenine (2) by benzylation, and proceeded through nonreductive debenzylation of the resulting 3-benzyladenine 7-oxide (6)