Microbial diversity and iron oxidation at Okuoku-hachikurou Onsen, a Japanese hot spring analog of Precambrian iron formations.

Banded iron formations (BIFs) are rock deposits common in the Archean and Paleoproterozoic (and regionally Neoproterozoic) sedimentary successions. Multiple hypotheses for their deposition exist, principally invoking the precipitation of iron via the metabolic activities of oxygenic, photoferrotrophic, and/or aerobic iron-oxidizing bacteria. Some isolated environments support chemistry and mineralogy analogous to processes involved in BIF deposition, and their study can aid in untangling the factors that lead to iron precipitation. One such process analog system occurs at Okuoku-hachikurou (OHK) Onsen in Akita Prefecture, Japan. OHK is an iron- and CO2 -rich, circumneutral hot spring that produces a range of precipitated mineral textures containing fine laminae of aragonite and iron oxides that resemble BIF fabrics. Here, we have performed 16S rRNA gene amplicon sequencing of microbial communities across the range of microenvironments in OHK to describe the microbial diversity present and to gain insight into the cycling of iron, oxygen, and carbon in this ecosystem. These analyses suggest that productivity at OHK is based on aerobic iron-oxidizing Gallionellaceae. In contrast to other BIF analog sites, Cyanobacteria, anoxygenic phototrophs, and iron-reducing micro-organisms are present at only low abundances. These observations support a hypothesis where low growth yields and the high stoichiometry of iron oxidized per carbon fixed by aerobic iron-oxidizing chemoautotrophs like Gallionellaceae result in accumulation of iron oxide phases without stoichiometric buildup of organic matter. This system supports little dissimilatory iron reduction, further setting OHK apart from other process analog sites where iron oxidation is primarily driven by phototrophic organisms. This positions OHK as a study area where the controls on primary productivity in iron-rich environments can be further elucidated. When compared with geological data, the metabolisms and mineralogy at OHK are most similar to specific BIF occurrences deposited after the Great Oxygenation Event, and generally discordant with those that accumulated before it.

Pachyonychia congenita associated with steatocystoma multiplex.

We present an unique case of pachyonychia congenita associated with steatocystoma multiplex. A 33-year-old Japanese man had thickening and gray-brown dicoloration of all nails and a large number of nodules or tumors over his entire skin. No palmar and plantar hyperkeratosis, leukokeratosis of the mucous membranes, or follicular keratosis were observed. Histology of these tumors revealed the typical features of steatocystoma multiplex.

An important role of tumor necrosis factor-alpha in the induction of adhesion molecules in psoriasis.

Recent studies have suggested that cell adhesion plays an important role in the development and regulation of inflammation. To elucidate the mechanisms of regulation of adhesion molecule expression by cytokines in psoriatic lesions, we compared the expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, and P-selectin immunohistochemically in involved and uninvolved psoriatic skin with the expression of these molecules in normal skin, and measured the amounts of tumor necrosis factor-alpha, interferon-gamma, interleukin-1alpha, and interleukin-1beta in the supernatant of freeze-thawed skin specimens using an enzyme-linked immunosorbent assay. There was strong staining for P-selectin on endothelial cells from involved skin. There was also strong staining for intercellular adhesion molecule-1 on keratinocytes, dermal infiltrates, and endothelial cells from involved skin and on endothelial cells from uninvolved skin, and strong staining for vascular cell adhesion molecule-1 on dermal dendritic cells and fibroblasts and for E-selectin on endothelial cells from involved skin. Large amounts of tumor necrosis factor-alpha were detected in six out of ten specimens of involved skin, but not in uninvolved or normal skin, although interferon-gamma was detected in both involved and uninvolved skin to the same extent. Neither interleukin-1alpha nor interleukin-1beta was detected in involved skin. There was strong staining for tumor necrosis factor-alpha on keratinocytes and endothelial cells from involved skin. These findings suggest that tumor necrosis factor-alpha might play an important role in the induction of vascular adhesion molecules in psoriatic lesions.

Detection of inflammatory cytokines in psoriatic skin.

Recent investigations have revealed the involvement of cytokines in the pathogenesis of psoriasis. This study examined the amount of inflammatory cytokines--interleukin-1 (IL-1), interleukin-6 (IL-6) and granulocyte macrophage colony-stimulating factor (GM-CSF)--released into the supernatants of organ cultures of involved and uninvolved skin from psoriatic patients and normal skin from healthy individuals. Bioassays were employed to detect the activities of IL-1 and IL-6. Enzyme-linked immunosorbent assay (ELISA) methods were used to quantitate immunoreactive IL-1 alpha, IL-1 beta, IL-6 and GM-CSF. The activity of IL-1 in uninvolved psoriatic skin was found to be increased relative to that in involved and normal skin, while immunoreactive IL-1 beta was found only in involved skin. A neutralization experiment showed that bioactive IL-1 was mostly attributable to IL-1 alpha. Uninvolved psoriatic skin also secreted higher amounts of both bioactive and immunoreactive IL-6 compared with involved skin. Immunoreactive GM-CSF was detected in uninvolved skin only. These cytokines detected in uninvolved skin may have been released from epidermal or mesenchymal cells, since uninvolved skin contained fewer inflammatory infiltrates. Our results offer additional evidence that increased amounts of inflammatory cytokines in uninvolved skin may provide a preliminary condition and play important roles in the initial events in the evolution of psoriatic lesions.

The coexistence of psoriasis vulgaris, Sjögren's syndrome, and Hashimoto's thyroiditis.

A 52-year-old woman presented with psoriasis vulgaris, Sjögren's syndrome, and Hashimoto's thyroiditis with a 5-year history. She had a number of immunological abnormalities and typical psoriatic plaques over her entire body. The relationship between psoriasis, Sjögren's syndrome, and Hashimoto's thyroiditis is discussed from the viewpoint of immunology, and similar cases in the literature are reviewed. This is the first report of a coexistence of psoriasis vulgaris, Sjögren's syndrome, and Hashimoto's thyroiditis.