Keiichi Hiramoto

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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)
The conditions which existed on the earth in its first billions of years contained little or no free molecular oxygen. It slowly appeared during a long period of biological evolution predominantly by the photosynthetic mechanism, and it rapidly increased after the Cambrian period. The Cambrian period is characterized by the occurrence of explosive gene(More)
To elucidate the roles of enteric bacteria and immunological interactions among liver, spleen and intestine in the pathogenesis of liver injury during obstructive jaundice, we studied the effects of antibiotics and splenectomy on bile-duct-ligated C57BL mice. When animals were subjected to bile-duct-ligation (BDL), plasma levels of bilirubin, alanine(More)
OBJECTIVE Although psychological and/or physiological stress has been well documented to influence immune responses, the precise mechanism for immunomodulation remains to be elucidated. The present work describes the role of the hypothalamic-pituitary-adrenal (HPA) axis in the mechanism of stress-mediated enhanced-resistance to lethality after(More)
We previously reported that the plasma level of endotoxin and colonic expression of IgA in the mouse increased with obstructive jaundice induced by bile duct ligation (BDL). To elucidate the mechanism of the BDL-induced increase, we analyzed the effect of BDL on intestinal flora in wild type and inducible nitric oxide synthase (iNOS)-deficient mice(More)
The immunological properties and hormonal metabolism in rodents are affected by physical and psychological stress more strongly in males than in females. To elucidate the mechanism and physiological significance of the sex difference in the susceptibility of animal to stresses, changes in the immunological system in plasma and intestine and hormonal status(More)
BACKGROUND A mild restraint stressor suppressed an increase in the levels of Th2-dependent cytokines and IgE, thereby reducing the symptoms of pollinosis. In the present study, to clarify the mechanism of action of adrenocorticotropic hormone (ACTH) in improving the symptoms of pollinosis, we studied the effects of ACTH on the plasma level of histamine,(More)
This study investigated the mechanism by which the strength and weakness of exercise stress affects the skin symptoms of atopic dermatitis (AD). Specific pathogen-free (SPF) and conventional NC/Nga mice were used. Conventional mice, but not the SPF, spontaneously develop dermal symptoms similar to that of patients with AD. There were two types of stress,(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 analyzed changes in the frequency of sneezing, plasma levels of NO metabolites, α-melanocyte-stimulating hormone (MSH) and immunoglobulin E and tracheal expression of IgA and mast cell tryptase in(More)
Seirogan, a wood creosote, has been used as an antidiarrhetic drug in Asian countries including Japan for many years. This antidiarrhetic has recently been used as a sugar-coated pill because Seirogan has a strong smell. The strong smell of the uncoated form of Seirogan may modulate the defense systems of animals because the sense of smell is important for(More)