UVA-Induced Immune Suppression Through an Oxidative Pathway

Although ultraviolet B (UVB) irradiation induces local immune or systemic immune suppression, depending on the dose, the immune suppression by ultraviolet A (UVA) has not been fully investigated. In this study, we investigated the effect of UVA on the immune response in vitro and in vivo. The effect of UVA on the antigen-presenting function of epidermal cells was measured in terms of antigen-specific T cell proliferation. A murine epidermal cell suspension was exposed to UVA in vitro, pulsed with trinitrobenzenesulfonic acid, and cultured with T cells prepared from syngeneic mice previously sensitized with trinitrochlorobenzene. UVA (5–20 J per cm2) suppressed the antigenpresenting function of epidermal cells in a dose-dependent manner, accompanied with suppression of the expression of costimulatory molecules on Langerhans cells. In order to investigate the effect of an antioxidant on the immune suppression, an epidermal cell suspension was irradiated with UVA in the presence or absence of glutathione. The suppressions of antigen-presenting function and ICAM-1 expression were significantly prevented by glutathione in a dose-dependent manner. Further, the effect of UVA on the immune response at the induction phase of contact hypersensitivity was evaluated in terms of lymph node cell proliferation ex vivo. UVA irradiation suppressed the endogenous proliferation of lymph node cells in trinitrochlorobenzene-painted mice, and this suppression was significantly reversed by the application of glutathione to the skin during irradiation. These results suggest that UVA-induced immune suppression may be mediated by reactive oxygen species, at least in part

Ganglion Cell Differentiation and Intermediate Filaments in the Cervical Dorsal Root Ganglion of the Chick Embryo

To examine the differentiation processes of cervical dorsal root ganglionic cells, vimentin, nestin and neurofilament-H protein were immunohistochemically detected in chick embryos from stages 15 through 43. During stages 15-17, migrating neural crest cells exclusively expressed vimentin. At stage 20, there was a marked decrease in vimentin, and appearance of nestin in most cells of the ganglionic primordia. However, a few Schwann precursor cells containing only vimentin were also observed. During stages 24-26, spindle-shaped precursors of pseudounipolar neurons containing neurofilament-H protein increased in number in the primordia of the ganglia. During stages 28-30, large round immature neurons containing neurofilament-H protein in both their perikaryon and neurites were recognized. At stage 36, the neurons contained neurofilament-H protein and transiently vimentin. In addition, the precursors of satellite cells, containing neither vimentin, nestin, nor neurofilament-H protein, could be observed around the neurons. At stage 43, three mature cell types could be distinguished; pseudounipolar neurons containing neurofilament-H protein, Schwann cells containing vimentin, and satellite cells containing neither vimentin, nestin, nor neurofilament-H protein. These results clearly demonstrate that differentiation of neural crest cells into neurons, Schwann cells and satellite cells, is reflected by the intermediate filament composition

What explains the recent fluctuations in Japan's output? A structural factor analysis of Japan's industrial production

Since the mid-2000s, Japan's industrial production (IP) has been characterized by increasing volatility. To examine the background to this, we apply the structural factor analysis developed by Foerster, Sarte, and Watson (2011) and decompose variations in Japan's IP into aggregate and sectoral shocks taking input-output relationships between sectors into account. We find that aggregate shocks explain most of the fluctuations in Japan's IP and are highly correlated with variations in overseas economic growth, especially since the early 2000s. However, we find a large increase in the relative importance of sectoral shocks when focusing on the more recent increase in the volatility of IP. Specifically, our analysis suggests that the intersectoral spillovers brought about by the disruptions of supply chain network in the wake of Great East Japan Earthquake and the declines of domestic production (or production capacity) in some sectors as a result of a deterioration in global competitiveness or the shift to overseas production have contributed to the recent fluctuations of Japan's IP

What explains the recent fluctuations in Japan's output? A structural factor analysis of Japan's industrial production

Since the mid-2000s, Japan's industrial production (IP) has been characterized by increasing volatility. To examine the background to this, we apply the structural factor analysis developed by Foerster, Sarte, and Watson (2011) and decompose variations in Japan's IP into aggregate and sectoral shocks taking input-output relationships between sectors into account. We find that aggregate shocks explain most of the fluctuations in Japan's IP and are highly correlated with variations in overseas economic growth, especially since the early 2000s. However, we find a large increase in the relative importance of sectoral shocks when focusing on the more recent increase in the volatility of IP. Specifically, our analysis suggests that the intersectoral spillovers brought about by the disruptions of supply chain network in the wake of Great East Japan Earthquake and the declines of domestic production (or production capacity) in some sectors as a result of a deterioration in global competitiveness or the shift to overseas production have contributed to the recent fluctuations of Japan's IP