Biomedical subjects
Publications and source records attributed to Y Nihei.
Lagunamycin, a novel 5-lipoxygenase inhibitor, was isolated from the culture broth of Streptomyces sp. AA0310. This compound showed potent rat 5-lipoxygenase inhibitory activity (IC50 6.08 microM) without lipid peroxidation.
The origin of Merkel cells is uncertain, although current evidence by immunohistochemical keratin marker studies favors an epidermal derivation. We studied the expression of keratin species in Merkel cells of human fetus and adult using 19 anti-keratin antibodies. Epidermal and dermal Merkel cells contained not only simple epithelium-type but also some stratified epithelium-type keratins. Interestingly, expression of some keratins was different between epidermal and dermal Merkel cells, for example, AN3 (50, 58 kD) and CKB1 (50 kD) recognized epidermal Merkel cells, but not dermal Merkel cells. These results suggest that surrounding keratinocytes influence the expression of cytokeratins in Merkel cells or that dermal Merkel cells undergo a modification from keratin-producing epidermal Merkel cells to a more neural cell type by the association with nerve endings in the upper dermis. On the other hand, certain cytokeratin polypeptides recognizable with Ks19.1 (40 kD), CK5 (45 kD), and CAM5.2 (52.5 kD) were expressed in both epidermal and dermal Merkel cells. The expression of simple epithelium-type keratins in Merkel cells remained even after the epidermal basal cells gradually lost their expression.
We detected epidermal Merkel cells in 12-week fetuses with monoclonal antibodies (MAb) against simple epithelium keratin and epithelial membrane antigen. In 15-week fetuses these Merkel cells began to descend into the dermis and expressed nerve growth factor receptors (NGF-R). At approximately the same time, cutaneous nerves, as detected with an MAb against neurofilaments, extended from the subcutaneous trunk and branched to form the subepidermal nerve plexus. The expression of NGF-R on dermal Merkel cells preceded their connection with immunoreactive small nerves. Initially, most of these fine nerve endings were directed towards dermal Merkel cells. In 23-week fetuses the subepidermal nerve plexus was well developed and immunoreactive dermal Merkel cells began to disappear. At all stage of fetal development the epidermal Merkel cells did not strongly express NGF-R. We postulate that dermal Merkel cells play an inductive and a promotional role in development of the cutaneous nerve plexus in the upper dermis.
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POEMS syndrome is a multi-system disorder characterized by polyneuropathy, organomegaly, endocrinopathy, the presence of monoclonal protein and skin changes. We describe a case with scleroderma and angiomatous vascular proliferation as skin alterations which may be involved in this syndrome.
Three children with classical Ehlers-Danlos syndrome were studied. Electron microscopic observation of the skin demonstrated a hyaluronic acid-dominant glycosaminoglycan structure in the intercellular matrix. Biochemical analysis showed a significant increase in hyaluronic acid content, as compared with the skin of sex- and age-matched children, including a non-affected brother of a patient. In addition, enhanced hyaluronic acid synthesis was demonstrated in vitro, using a patient's dermal fibroblasts. Analysis of the collagen showed no apparent abnormalities.
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A simple circular odor chart is proposed for the explanation of the relationship between sensory responses (to odor quality and intensity) to odors and chemical analysis data of the odorants responsible for each odor discharged from thirteen odor sources. The odorants were classified into eight odorant groups and were analyzed by a systematic gas chromatographic (GC) technique. The characterization of the trace amounts of the odorants was carried out by using the values of a new proposed unit (pOU) based on the ratio of detected concentration to recognition threshold value. The calculated pOU values of the eight groups were plotted in circular charts. It was found that the shape and size of each circular odor chart represent the quality and the intensity of each odor.
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Topical application of 1alpha,25-dihydroxyvitamin D3 (VD3) is thought to be beneficial in psoriasis because of its action in regulating keratinocyte proliferation and inflammation mediated by various cytokines. We assessed the effect of VD3 on the production levels of interferon (IFN)-alpha, interleukin (IL)-6, IL-8 and tumor necrosis factor (TNF)-alpha in mitogen-stimulated peripheral blood mononuclear cells (PBMC) of psoriatic patients. The results demonstrated that VD3 significantly inhibited IFN- , IL-6, and IL-8 levels produced by concanavalin A (Con A)-stimulated PBMC of psoriatic patients in a dose-dependent manner, and reduced mRNA expression for IFN- and IL-8. These findings suggest that in addition to the direct anti-proliferation effect on keratinocytes, VD3 may down-regulate the inflammatory cytokine production by infiltrating cells in psoriatic lesions.