BACKGROUND: Nitric oxide synthase (NOS) is known to mediate ultraviolet B (UVB)-induced skin inflammation However, there is still ambiguity as to which NOS isotype mediates the process in vivo. Furthermore, contradictory results have been reported on which cell types respond to UVB irradiation in vitro. OBJECTIVE: This study was performed to evaluate the change of inducible NOS (iNOS) expression in vivo as a result of UVB radiation on the skin of a rat. METHOD: To examine the time-course change in iNOS expression in the rat skin, the rats were exposed to 400 ml/cm2 of UVB radiation, and skin samples were taken at various time intervals up to 48 h. iNOS expression on the skin of a rat was evaluated by both Western blot analysis and immunohistochemical staining. RESULTS: From Western blot analysis, UVB irradiation induced inducible NOS (iNOS) expression in the epidermis at 12-48 h postirradiation with a peak expression at 24 h. Immunohistochemical staining revealed that UVB-induced iNOS expression was localized to the epidermis and infiltrating inflammatory cells in the upper dermis of the rat. CONCLUSION: iNOS was induced by UVB irradiation on the skin of a rat, mainly in the epidermis. Therefore, iNOS is supposed to be one of the major mediators with regard to inducing an inflammatory response in UVB-irradiated rat skin in vivo.
Animals ; Blotting, Western ; Dermis ; Epidermis ; Inflammation ; Nitric Oxide Synthase ; Nitric Oxide Synthase Type II* ; Rats* ; Skin*

Hypereosinophilic syndrome (HES) is characterized by a sustained eosinophilia of 1,500/mm3 or more in the absence of any known causes or the signs and symptoms of organ involvement. We report a 64-year-old man with HES initially presenting with involvement of the liver and bone marrow. Despite controlling the eosinophilia by corticosteroid, he developed a cerebral infarction and later progressive interstitial pneumonia. Brain angiography revealed a severe stenosis of the proximal right internal carotid artery (ICA) and a complete obstruction of the intracranial ICA. An open lung biopsy revealed fibrosis and lymphoplasma cell infiltration without eosinophils, which were consistent with nonspecific interstitial pneumonia.
Angiography ; Biopsy ; Bone Marrow ; Brain ; Carotid Artery, Internal ; Cerebral Infarction ; Constriction, Pathologic ; Eosinophilia ; Eosinophils ; Fibrosis ; Humans ; Hypereosinophilic Syndrome* ; Liver ; Lung Diseases, Interstitial ; Lung* ; Middle Aged