Publications by authors named "Ryoji Hirose"

We investigated the structure-activity relationship between various ISP-I (myriocin, thermozymocidin) analogous which has sphingosine-like structure and serine palmitoyltransferase (SPT) in Chinese hamster ovary (CHO) cells utilizing sphingolipid production as a marker. Our data suggest that the double bond and/or ketone group within the alkyl chain as well as the alkyl chain are necessary for ISP-I to inhibit SPT. In addition, a serine structure is necessary for SPT inhibitory activity, which confirms previous findings.

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The key intermediate, diethyl 2-acetylamino-2-(2-(4-octanoylphenyl)ethyl)propane-1,3-dioate (13), for the immunomodulatory agent FTY720 (2: fingolimod) was synthesized via Michael addition of diethyl(acetylamino)malonate (6) to 4-octanoylstyrene (12).

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FTY720 (1) is a novel immunosuppressant (immunomodulator), derived from ISP-I (2: myriocin and thermozymocidin). To clarify the pharmacokinetic properties of 1, antibodies against 1 were prepared and a competitive enzyme immunoassay (EIA) was developed. Two kinds of haptens, 3 and 4, for 1 were synthesized and coupled to ovalbumin (OVA).

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Although many studies have been reported on the repair of ultraviolet light (UV)-induced cyclobutane-type pyrimidine dimers (CPDs) in DNA, the effects of aging on the removal of UV-induced CPDs from the human skin epidermis in vivo remains uncertain. Therefore, we employed immunoblotting and immunohistochemical methods using monoclonal antibodies (TDM-2) to CPDs to study age-related differences in the time required for the in vivo removal of UVB-induced CPDs. The flexure surfaces of the upper arms of five young men were exposed to UVB light at a fluence of 35 and 700 mJ/cm2, and four older men were also irradiated with the same doses of UVB mentioned above.

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We report a 66-year-old woman with localized argyria caused by embedding of acupuncture needles. Ten years after she had received acupuncture, she noticed two asymptomatic bluish macules on her right arm. A biopsied specimen from the macule revealed many brownish-black granules mainly located around the sweat glands and the blood vessels in the dermis.

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