Keiichi Hiramoto

Learn More
Phthalate esters have been used extensively as plasticizers of synthetic polymers. Recent studies have revealed that these esters induce atrophy of the testis, although its pathogenesis remains unknown. The present study describes the possible involvement of oxidative stress in the pathogenesis of atrophy of the rat testis induced by(More)
BACKGROUND The risk of skin cancer is lower in females than in males, and photoimmunosuppression caused by ultraviolet (UV) radiation is thought to be involved in the progression of skin cancer. OBJECTIVES. To determine the effect of 17beta-estradiol on immunosuppression and contact hypersensitivity (CHS) caused by ultraviolet B (UVB) irradiation. METHODS(More)
We previously reported that superoxide generated in the ovary induces apoptosis of granulosa cells to break down follicular walls, thereby supporting ovulation in rodents, and suggested that oxidative stress underlies the mechanism of ovarian aging. To test this hypothesis, we successfully induced ovulation repeatedly in mice by sequentially administrating(More)
To elucidate the possible involvement of nitric oxide (NO) derived from inducible NO synthase (iNOS) in the pathogenesis of patients with allergic rhinitis, we used an animal model of atopic dermatitis (AD) induced by epicutaneous sensitization and analysed the differences in ear thickness, the frequency of scratching and plasma levels of ovalbumin-specific(More)
Ultraviolet B radiation increases DOPA-positive melanocytes in the skin specifically at the site of exposure. We found unexpectedly that ultraviolet B irradiation of the eye increased the concentration of alpha-melanocyte-stimulating hormone in plasma and systemically stimulated epidermal melanocytes in mice. To test the possible involvement of(More)
Reactive oxygen species (ROS) are the major factors that induce oxidative modification of DNA and gene mutation. ROS can elicit oxidative stress and affect a wide variety of physiological and pathological processes including embryonal development, maturation and aging.
We have previously reported that impaired skin barrier function was induced by small intestinal injury in mice. Therefore, we postulated that other intestinal diseases might also influence skin barrier function. In this study, we evaluated the skin barrier function of hairless mice with colon carcinoma that was induced by azoxymethane (AOM) and dextran(More)
We previously observed that female mice survived significantly longer than male mice under fasting conditions. To elucidate the mechanism underlying the sex different effect of fasting, we analyzed various events induced in male and female mice. Kinetic analysis revealed that fasting elicited hypothermia and decreased muscle weight more apparently in male(More)
BACKGROUND Ketoprofen, suprofen and tiaprofenic acid are arylpropionic anti-inflammatories. Their chemical structures share the same elements as the benzoyl radical and the tiophene ring. We experienced nine cases of ketoprofen photoallergy, seven cases of suprofen photoallergy and three cases of tiaprofenic photoallergy. PURPOSE To find the key structure(More)
Dietary nitrate is reduced to nitrite by some oral bacteria and the resulting nitrite is converted to nitric oxide (NO) in acidic gastric juice. The aim of this study is to elucidate the pathophysiological role of dietary nitrate in the stomach. Intragastric administration of nitrate rapidly increased nitrate and NO in plasma and the gastric headspace,(More)