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Biomedical subjects

R Tsuboi

Publications and source records attributed to R Tsuboi.

At least 19 recordsLinked to original sources
PubMed1996

Immunolocalization of epimorphin in skin.

Epimorphin was originally identified as a mesenchymal cell surface-associated protein that modulates epithelial morphogenesis in embryonic skin and lung epithelia. A previous report which utilized embryonic mouse skin, showed that epimorphin was localized non-homogeneously in a region adjacent to the epidermis and in a mesenchymal cell condensation located in front of growing hair follicles. We report herein a further detailed localization of this protein in adult mouse skin using immunoelectron microscopy. Epimorphin was found to be localized on the undersurface of basal cells, in the cytoplasm of cell processes of fibroblasts, as well as on the plasma membrane of fibroblasts, endothelial cells, pericytes, perineurium and endomysium. Our present finding indicated that epimorphin is one of the factors involved in multiple biological functions in a variety of structures derived from various origins and that it is not a specific epithelial morphogenetic factor.

Animals↗
PubMed1996

Giant mixed tumor of the face.

A 35-year-old Japanese man consulted our clinic with an eight year history of a 6 cm diameter subcutaneous tumor on the left cheek. Hematoxylin and eosin staining of the resected section showed histology corresponding to a benign chondroid syringoma. Keratin was positive in most of the constituent cells, and S-100 protein was positive in the cells distant from the lumens and in myxomatous cells. A benign chondroid syringoma of this size has only been very rarely reported in the literature.

Adenoma, Pleomorphic↗
PubMed1996

Induction of an extracellular esterase from Candida albicans and some of its properties.

An extracellular esterase from Candida albicans A-714 was found to be induced in a medium containing 0.7% yeast nitrogen base and 2.5% Tween 80 (polyoxyethylenesorbitan compounds). Enzyme activity, which exists predominantly in the extracellular space, was measured by a colorimetric method using alpha-naphthyl palmitate as a substrate. The induction level of the esterase activity was found to be well correlated with fungal growth and was dependent on the Tween 80 concentration. Such esterase activity was observed only in medium containing Tween 80 or other Tweens as the sole carbon source and therefore was not observed in either peptone-glucose medium or peptone-glucose medium supplemented with Tween 80. The induced esterase was heat labile and had maximum activity at pH 5.5. Enzyme activity was stimulated by the addition of sodium taurocholate, an activator of lipase. Thin-layer chromatography revealed that this enzyme does not hydrolyze triolein and L-alpha-lecithin, suggesting that it is a monoester hydrolase (not a lipase in the strict sense of the word). Esterase activity was examined in 85 clinical isolates of Candida species; C. albicans, C. tropicalis, and C. parapsilosis tended to have higher enzyme activities than C. kefyr, C. krusei, C. glabrata, and C. guilliermondii. Although the physiological properties of this esterase are not clear at present, it was found to be crucial for fungal growth under specific conditions.

Candida albicans↗
PubMed1996

Combination of insulin-like growth factor (IGF)-I and IGF-binding protein-1 promotes fibroblast-embedded collagen gel contraction.

Wound contraction is an important event that minimizes the wound defect during the healing process. Involvement of insulin-like growth factor (IGF)-I and IGF-binding protein (IGFBP)-1 in wound contraction was studied using an in vitro model. Human dermal fibroblasts (1 x 10(5) cells/ml) were incorporated into a porcine type I collagen (0.21% final) in serum-free medium. The fibroblast-embedded collagen gels in a 12-well plate were floated from the well, and various reagents were then added to the assay medium. The surface area of the gel was calculated by measuring the diameters of the collagen gel. IGF-I at high doses (30 and 100 ng/ml) revealed 6.8% (P < 0.01) and 7.7% (P < 0.001) gel contraction, respectively, and des (1-3) IGF-I at 10 ng/ml produced a 4.5% gel contraction (P < 0.01). Meanwhile, IGFBP-I did not induce any significant contraction throughout the tested concentrations (0.1-100 ng/ml). A combination of IGF-I and IGFBP-1 at 1 ng/ml of each reagent, a concentration at which gel contraction was not observed when each of the reagents was tested individually, produced a 14% gel contraction (P < 0.001), whereas combinations of des (1-3) IGF-I with IGFBP-1 at the same concentrations did not promote gel contraction. The increased IGFBP-I doses in combination with 1 ng/ml IGF-I tended to enhance the gel contraction. IGF-I- and IGFBP-1-induced gel contraction was prominent during the initial 12-h incubation period. When anti-IGF-I, anti-IGFBP-1, or anti-IGF-I receptor antibody was added to the assay medium before the addition of IGF-I and IGFBP-1, the IGF-I- and IGFBP-1-induced gel contraction was significantly suppressed (P < 0.001). Endothelin-1, a vasoconstrictor peptide that is known to promote fibroblast-embedded collagen gel contraction, appeared to be partially involved in the IGF-I- and IGFBP-1-induced gel contraction, because the addition of an endothelin receptor antagonist (Bosentan or BE-18257B at 1 microg/ml) moderately suppressed the IGF-I- and IGFBP-1-induced gel contraction (P < 0.01). On the other hand, when IGF-I and IGFBP-1 were applied with endothelin-1 (1 nM), an enhanced gel contraction (29.4%) was observed that was significantly greater than that induced by either individually (P < 0.001). These results clearly indicate that the combination of IGF-I and IGFBP-1 promotes fibroblast contraction in collagen gel, and that this phenomenon is caused by IGFBP-1's strong potentiation of the IGF-I-induced gel contraction.

Antibodies↗
PubMed1995

Ultraviolet B irradiation increases endothelin-1 and endothelin receptor expression in cultured human keratinocytes.

The effect of ultraviolet B (UVB) irradiation on endothelin-1 (ET-1) and ET receptor expression was examined using cultured normal human keratinocytes. Keratinocytes secreted ET-1 in the medium at a level of 2.1 pg/day/10(5) cells. UVB irradiation up to 10 mJ/cm2 increased ET-1 secretion 3-fold, and potentiated expression of mRNA for ET-1. Both ETA and ETB receptor mRNAs were detected in keratinocytes, and their expression was up-regulated by 5 mJ/cm2 UVB irradiation.

Base Sequence↗
PubMed1995

Hepatocyte growth factor/scatter factor expressed in follicular papilla cells stimulates human hair growth in vitro.

Hepatocyte growth factor/scatter factor (HGF/SF) is a multifunctional polypeptide which acts as mitogen, motogen, or morphogen. In this study, we examined the effect of HGF/SF on human hair growth using organ and cell culture systems. HGF/SF was found to stimulate hair length and DNA synthesis in hair follicles at increasing concentrations up to 10 ng/ml (P < 0.05 and P < 0.01, respectively). HGF/SF stimulated [3H]thymidine incorporation by hair bulb-derived keratinocytes with the strongest response at 30 ng/ml of HGF/SF (P < 0.05). Cultured follicular papilla cells secreted HGF/SF, measured by an enzyme-linked immunoassay, in response to interleukin 1-alpha (IL1-alpha, 10 ng/ml), tumor necrosis factor-alpha (TNF-alpha, 10 ng/ml), or tetradecanoylphorbolacetate (100 nM) at levels ranging from 0.2 to 0.3 ng/mg protein/48 h. HGF/SF mRNA expressions, measured by the reverse transcription-polymerase chain reaction, were detected in follicular papilla cells, and were also stimulated by the three reagents. Transforming growth factor-beta (10 ng/ml) suppressed both protein and mRNA levels. These results suggest that hair follicle elongation induced by HGF/SF in organ culture occurs partly due to the mitogenic activity of HGF/SF expressed in follicular papilla cells on hair bulb-derived keratinocytes.

Base Sequence↗
PubMed1995

The effect of hepatocyte growth factor/scatter factor on human hair follicle growth.

The effect of hepatocyte growth factor/scatter factor (HGF/SF) on human hair follicle growth was examined using a serum-free organ culture system. The DNA synthesis in human hair follicles and elongation of the hair shaft were measured subsequent to the follicle isolation and culture at 31 degrees C in 95% O2-5% CO2 for 72 h. Results showed that HGF/SF significantly increased 3H-thymidine (P < 0.001) incorporation and hair follicle length (P < 0.05). The effect of HGF/SF was dose-dependent with a maximal stimulation at 10 ng/ml.

Adolescent↗
PubMed1995

Comparative study of hepatocyte growth factor/scatter factor and keratinocyte growth factor effects on human keratinocytes.

Hepatocyte growth factor/scatter factor (HGF/SF) and keratinocyte growth factor (KGF, also designated FGF-7) are paracrine growth factors secreted by mesenchymal cells and active on a variety of epithelial cell types. In this study, the biologic responses of keratinocytes to these paracrine growth factors were compared. Stimulation of mitogenesis, migration, plasminogen activator (PA) activity, and fibronectin production were examined using human foreskin keratinocytes cultured in serum-free MCDB 153 medium. Although the two factors stimulated a similar level of proliferation when cells were maintained for 5 d in 1.8 mM Ca++, the peak effect of KGF, observed at 10 ng/ml, was approximately threefold higher than that of HGF/SF when cells were in medium containing 0.15 mM Ca++. Both agents promoted the migration of cells in low-calcium medium (0.08 mM Ca++). However, the magnitude of the response was approximately twofold greater for HGF/SF at 10 ng/ml than KGF at the same concentration. None of the matrix proteins such as type I collagen, type IV collagen, laminin, or fibronectin either stimulated or suppressed HGF/SF- or KGF-stimulated keratinocyte migration. Both factors stimulated PA activity of the cell extracts, especially urokinase-type, with similar potencies. Promoted PA activity was maximal with the addition of 10 ng/ml of either factor. Neither factor increased the production of fibronectin under conditions in which transforming growth factor-beta 1 was active. These results indicate that HGF/SF and KGF, both recognized as paracrine growth factors, elicit distinctive patterns of response by keratinocytes, implying that they have different roles in epidermal physiology.

Cell Movement↗
PubMed1995

Co-administration of insulin-like growth factor (IGF)-I and IGF-binding protein-1 stimulates wound healing in animal models.

The stimulatory effect of recombinant human insulin-like growth factor-I (rhIGF-I) and recombinant human insulin-like growth-factor-binding protein-1 (rhIGFBP-1) on wound healing was assessed using diabetic db/db mice and normal rabbits. Full-thickness wounds of 6 mm diameter were prepared on the backs of diabetic C57BL/KsJ db/db mice and on the inner sides of normal rabbit ears. Various concentrations of rhIGF-I and/or rhIGFBP-1 were applied locally to the open wounds of db/db mice once daily for 5 d and to the covered wounds of normal rabbits once after wounding. Sections of the wounds were evaluated histologically on the seventh or eighth day by measuring re-epithelialization (%), area of granulation tissue (mm2), and capillary numbers. Wound repair was accelerated by each of the treatments in descending order of rhIGF-I plus rhIGFBP-1, rhIGF-I, rhIGFBP-1, and vehicle alone. In db/db mice, the combination of 50 micrograms rhIGF-I and 165 micrograms rhIGFBP-1 (equimolar ratio) significantly stimulated granulation tissue formation (p < 0.01) and capillary numbers (p < 0.05). Doses of rhIGFBP-1 greater than 16.5 micrograms were required for significant acceleration of the healing stimulated by 50 micrograms of rhIGF-I. In normal rabbits, co-administration of 10 micrograms rhIGF-I and 33 micrograms rhIGFBP-1 (equimolar ratio) significantly stimulated all three wound-healing parameters (p < 0.01), with such stimulation being much greater than that induced by rhIGF-I alone. Interestingly, rhIGFBP-1 alone showed a mild stimulatory activity on wound healing in both models despite its lack of mitogenic activity in vitro. These results demonstrate that rhIGFBP-1 enhances the stimulatory activity of rhIGF-I on wound healing and suggest the clinical utility of the co-administration of rhIGF-I and rhIGFBP-1 for wound repair.

Animals↗
PubMed1995

A case of Behçet's disease aggravated by gingival infection with methicillin-resistant Staphylococcus aureus.

We report a case of Behçet's disease aggravated by gingivitis and carious teeth infected with methicillin-resistant Staphylococcus aureus. Recurrent severe ulcers in the mouth, and on the genitalia and legs were closely linked with the infection, and dramatically improved after extraction of the carious teeth and administration of systemic vancomycin hydrochloride.

Anti-Bacterial Agents↗
PubMed1995

A case of angiocentric T-cell lymphoma presenting as lethal midline granuloma.

A case of angiocentric T-cell lymphoma with glabellar skin being the only affected site was reported. A 43-year-old woman had a several months' history of glabellar swelling followed by progressive and destructive ulceration of the region. Histopathology of the biopsied specimen showed panniculitis with atypical lymphocytes and degenerative vessels filled with atypical cells. Most of the infiltrated lymphocytes were positive for CD2, CD3, CD4 and CD5. Antibodies to Epstein-Barr virus were detected in the patient serum. Intensive chemotherapy using a protocol of the L17M regimen was partially effective for clinical manifestations. Angiocentric T-cell lymphoma presenting as lethal midline granuloma is a rare but distinct entity with an acute fatal course.

Adult↗
PubMed1994

Endothelin-1 acts as an autocrine growth factor for normal human keratinocytes.

Endothelin-1 (ET-1) is an endothelium-derived 21 amino acid vasoconstrictor peptide possessing two intrachain disulfide bridges. Recently it has become evident that isoforms of ET (ET-1, -2, and -3) have a wide range of pharmacological effects in various tissues and act as autocrine/paracrine factors. We demonstrate here that ET-1 is secreted from normal human keratinocytes and may work as an autocrine growth factor through a specific receptor. In this study, human foreskin keratinocytes were cultured in serum-free MCDB 153 medium. Cell growth and [3H] thymidine incorporation in low and high Ca++ concentration media was stimulated by ET-1, -2, and -3 with similar potencies. The strongest response was observed at 10 nM ETs, whereas stimulatory activity was reduced at 100 nM. ETs suppressed keratinocyte differentiation as measured by reactivity with involucrin antibody. Plasminogen activator activity (mainly urokinase) in the medium was also stimulated by the addition of 10 nM ETs. ET-1-like immunoreactivity measured by radioimmunoassay was 1.4 fmol/day/10(6) cells in non-treated condition medium. Among the various cytokines, tumor necrosis factor-alpha (TNF-alpha), interleukin-1 alpha, and transforming growth factor-beta stimulated ET-1 secretion in a dose-dependent manner. The strongest response (ten-fold) was observed upon the addition of 10 ng/ml TNF-alpha. Scatchard plot analysis of [125I] ET-1 binding to keratinocytes revealed the presence of a single class of high affinity receptors (KD 50 pM, 9 x 10(3) sites/cell). Binding was competitively inhibited by the addition of unlabeled ET-1 and -2 with similar affinities and by ET-3 with weaker affinity. ET-1 mRNA expression in keratinocytes was detected by reverse transcription-polymerase chain reaction and was increased by treatment with 10 ng/ml TNF-alpha. These results suggest that ET-1 acts as an autocrine growth factor for keratinocytes through a specific receptor.

Base Sequence↗
PubMed1994

The effect of various cytokines on hair growth of mouse vibrissae in organ culture.

Hepatocyte growth factor/scatter factor (HGF) is a multifunctional polypeptide which acts as a mitogen, motogen or morphogen depending on the biological context. In this study, we examined the effect of HGF on hair growth using a serum-free organ culture system. Vibrissal hair follicles isolated from newborn mice were cultured at 31 degrees C in 95% O2-5%CO2 for 72 h in the presence of various cytokines or growth factors. DNA, protein synthesis and elongation of the hair shaft in the hair follicles were measured. Among the agents tested, only HGF significantly increased hair follicle length (P < 0.001) and 3H-thymidine (P < 0.001) incorporation. The effect of HGF was dose-dependent, with maximal stimulation obtained at 10 ng/ml. The increase in hair follicle length and thymidine incorporation were specifically inhibited by a neutralizing antibody against HGF. These results indicate that HGF is able to promote hair growth and may have clinical utility in this regard.

Animals↗
PubMed1994

Hepatocyte growth factor/scatter factor stimulates hair growth of mouse vibrissae in organ culture.

Hepatocyte growth factor/scatter factor (HGF/SF) is a multifunctional polypeptide that acts as a mitogen, motogen, or morphogen, depending on the biologic context. In this study, we examined the effect of HGF/SF on hair growth using a serum-free organ culture system. Vibrissal hair follicles isolated from newborn mice were cultured at 31 degrees C in 95% O2/5% CO2 for 72 h in the presence of various cytokines or growth factors, and elongation of hair shaft, DNA, and protein synthesis in hair follicles were measured. Among the agents tested, only HGF/SF significantly increased hair follicle length (p < 0.001), 3H-thymidine (p < 0.001), and 35S-cysteine (p < 0.05) incorporation. The effect of HGF/SF was dose dependent, with maximal stimulation obtained at 10 ng/ml. The increase in hair follicle length and thymidine incorporation were specifically inhibited by a neutralizing antibody against HGF/SF. These results indicate that HGF/SF can promote hair growth and may have clinical utility in this regard.

Animals↗