Biomedical subjects
Publications and source records attributed to H Okochi.
Two cases of sclerotic fibromas directly related to the tendon sheath are presented. Fibroma in these 2 cases consisted of hypocellular, homogeneous collagen bundles that were closely related to the subjacent tendon sheath, and were described by the term 'sclerotic fibroma of tendon sheath'. It is possible that the sclerotic fibroma may arise from fibroma of tendon sheath and that common pathomechanisms exist between these two types of fibroma.
Tetra-spans transmembrane family (TSTF) members (CD9, CD37, CD53, CD63, CD81 and CD82) have potent effects on cell growth, motility and adhesion in various cells. However, little is known about their expression in human skin. Using immunohistological techniques, we have studied the localization of all six members of TSTF in normal and carcinomatous human keratinocytes. CD9, CD81 and CD82 were expressed in the entire living layers of the epidermis. Their staining pattern was quite similar, and was mainly intercellular with occasional intracellular immunoreactivity. CD53 expression was confined to the intercellular spaces of the upper spinous or granular layer in the normal epidermis. No clear-cut expression of CD63 could be detected in the epidermis. CD37 was not detected at all. Cultured human keratinocytes also expressed CD9, CD81 and CD82 at the surface membrane of cell-cell boundaries. Expression of CD37 and CD53 was negative in cultured keratinocytes, while CD63 was clearly localized in the cytoplasmic lysosomes. An immunoprecipitation assay revealed that alpha 3 beta 1 integrin is molecularly associated with CD9. The expression of CD9, CD81 and CD82 was markedly down-regulated in basal cell carcinoma but not in Bowen's disease. The abundant and differential expression of TSTF molecules and the selective association of CD9 with alpha 3 beta 1 integrin suggest that the TSTF molecules may be involved in the regulation of epidermal differentiation and integrity in vivo.
We reported previously that transforming growth factor beta (TGF-beta) selectively induced high levels of connective tissue growth factor (CTGF) mRNA and protein in human skin fibroblasts. In this study, we investigated the molecular mechanism for TGF-beta regulation of CTGF gene expression. Northern blot and run-on transcription assays indicate that TGF-beta directly activates transcription of the CTGF gene. Fragments of the 5'flanking region of the human CTGF gene were linked to luciferase reporter constructs. TGF-beta induced a 25-30 fold increase in luciferase activity in NIH/3T3 fibroblasts that had been transfected with this construct compared with nontreated cells after 24 h incubation. Other growth factors, such as platelet derived growth factor or fibroblast growth factor, caused only a 2-3-fold induction. This response to TGF-beta occurred only in human skin fibroblasts, fetal bovine aortic smooth muscle cells, and NIH/3T3 fibroblasts but not in the epithelial cell lines tested. Analysis of deletion mutants indicated that an important TGF-beta regulatory element is located between positions -162 and -128 of the CTGF promoter sequence. A fragment of the promoter containing this region conferred TGF-beta induction to a SV40 enhanceriess promoter. Methylation interference and competition gel shift assays mapped a unique 13-nucleotide sequence delineating a novel TGF-beta cis-regulatory element. Point mutations in this region result in a complete loss of the TGF-beta induction, identifying this sequence as a new TGF-beta response element.
Despite a number of studies, the etiology of keloids remains unknown. We have investigated the response of fibroblasts derived from keloid tissue and normal adult skin to platelet-derived growth factor (PDGF), epidermal growth factor (EGF), and fibroblast growth factor (FGF). Keloid fibroblasts were more responsive in both chemotactic and mitogenic assays to all three isoforms of PDGF than fibroblasts from normal skin. No enhanced response of the cells to either EGF or FGF was detected. The enhanced PDGF response of keloid fibroblasts appears to be mediated by elevated levels of PDGF alpha receptors, which are 4-5 times higher than those in normal human skin fibroblasts.
Connective tissue growth factor (CTGF) is a cysteine-rich peptide that exhibits platelet-derived growth factor (PDGF)-like biological and immunological activities. CTGF is a member of a family of peptides that include serum-induced immediate early gene products, a v-src-induced peptide, and a putative avian transforming gene, nov. In the present study, we demonstrate that human foreskin fibroblasts produce high levels of CTGF mRNA and protein after activation with transforming growth factor beta (TGF-beta) but not other growth factors including PDGF, epidermal growth factor, and basic fibroblast growth factor. Because of the high level selective induction of CTGF by TGF-beta, it appears that CTGF is a major autocrine growth factor produced by TGF-beta-treated human skin fibroblasts. Cycloheximide did not block the large TGF-beta stimulation of CTGF gene expression, indicating that it is directly regulated by TGF-beta. Similar regulatory mechanisms appear to function in vivo during wound repair where there is a coordinate expression of TGF-beta 1 before CTGF in regenerating tissue, suggesting a cascade process for control of tissue regeneration and repair.
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A Japanese woman with lichen planus pemphigoides is reported. Immunologic characteristics of lichen planus pemphigoides antigen in the patient were investigated by indirect immunofluorescence and compared with those of bullous pemphigoid antigen or epidermolysis bullosa acquisita antigen. Ultrastructural localization of lichen planus pemphigoides antigen was studied with the use of immunoelectron microscopic techniques. Lichen planus pemphigoides antigen showed localization similar to that of bullous pemphigoid antigen but different from that of epidermolysis bullosa acquisita antigen. The antigenic stability of lichen planus pemphigoides antigen was different from that of bullous pemphigoid antigen or epidermolysis bullosa acquisita antigen. Thus this study demonstrates that lichen planus pemphigoides antigen is different from bullous pemphigoid antigen.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Water-in-oil-in-water (w/o/w) emulsions encapsulating tryptophan or theophylline were prepared where these compounds are regarded as model drugs. The effects of sodium chloride on the drug entrapment into the w/o/w emulsions and on the separation of aqueous phases were studied. The degree of encapsulation of tryptophan in the w/o/w emulsion increased with the concentration of sodium chloride added in the inner aqueous phase, while it decreased with that in the outer aqueous phase. As for theophylline, although the degree increased with a concentration of sodium chloride in the inner phase, the effect was smaller than that on tryptophan. The difference in the effects between on tryptophan and on theophylline was attributed to their partition coefficients. Theophylline was easily leaked out from the inner phase to the outer aqueous phase after its dissolution and diffusion in the oil phase due to a higher partition coefficient. More than 55% of the aqueous phase was separated from the w/o/w emulsion within 24 h, when sodium chloride was not added in the inner aqueous phase. However, the separation was not observed when more than 0.2M sodium chloride was added. To the contrary, sodium chloride added in the outer aqueous phase accelerated the separation. It was, therefore, concluded that sodium chloride in the inner aqueous phase plays an important role in suppression of the separation and in encapsulation of the drug which does not penetrate into the oil membrane.
The hair reconstitution assay is a useful system for studying cell-cell and epithelial-mesenchymal interaction. The current method consists of transplantation of both epidermal and dermal cells, using a silicone chamber placed on an athymic nude mouse. However, because of leakage and tilting of the grafted cells, the rate and area of hair growth vary depending on the chamber. We modified this method by using a collagen sponge as a scaffold and compared two types of collagen sponges, each having different tensile strengths. A conventional collagen sponge disturbed normal hair follicle formation; in contrast, a collagen sponge containing polyglycolic acid (PGA) fiber supported proper restructuring of skin and hair follicles. These data suggested the usefulness of PGA fiber-containing collagen sponges for hair reconstitution in research and clinical applications.