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Y Miyachi

Publications and source records attributed to Y Miyachi.

At least 91 records · Page 5Linked to original sources
PubMed1999

Cord-blood-derived human cultured mast cells produce interleukin 13 in the presence of stem cell factor.

BACKGROUND: Mast cells have been regarded as a potential source of cytokines. Although the human mast cell line HMC-1 and human lung mast cells have been shown to produce interleukin (IL) 13, it still remains uncertain whether cord-blood-derived human cultured mast cells produce IL-13. METHODS: Human cultured mast cells were raised from cord blood cells in the presence of stem cell factor (SCF) and IL-6. Levels of IL-13 mRNA were examined by a semiquantitative reverse transcriptase-polymerase chain reaction. IL-13 levels in the supernatants were measured with an enzyme-linked immunosorbent assay. RESULTS: When the IgE-sensitized cultured mast cells were activated with anti-IgE, mRNA for IL-13 was amplified with a peak at 3 h after the stimulation. IL-13 was not detected in the supernatants of the activated mast cells in the absence of SCF, whereas the mast cells secreted significant amounts of IL-13 after the stimulation in the presence of SCF. Calcium ionophore A23187 also stimulated the mast cells to release IL-13 into the supernatant in the presence of SCF. CONCLUSIONS: These observations suggest that human mast cells can produce IL-13 under the condition with SCF. The cord-blood-derived human cultured mast cells will help in studying the functional properties of human mast cells in allergic diseases.

Calcimycin↗
PubMed1999

Serum concentration of 20K human growth hormone (20K hGH) measured by a specific enzyme-linked immunosorbent assay. Study Group of 20K hGH.

Several GH isoforms have been identified in pituitary and serum, the most abundant of which is the 22K human GH (hGH) isoform. The 20K hGH isoform is produced by alternative splicing of GH messenger ribonucleic acid and comprises approximately 10% of all GH in the pituitary. The physiological role of 20K hGH remains to be determined, partly because of the lack of a simple and specific assay. We have established sensitive enzyme-linked immunosorbent assays (ELISAs) specific to 20K and 22K hGH. To determine whether regulation of 20K hGH secretion is the same as that for 22K hGH, we measured serum concentrations of both species of hGH in normal subjects and patients with a variety of endocrine disorders. The serum levels of 20K hGH after overnight fasting was 118 +/- 178 pg/mL (n = 282) in normal women, significantly higher than that in normal men (64 +/- 170 pg/mL; n = 226). However, there was no difference in the proportion of 20K hGH to 20K plus 22K hGH between men (6.3 +/- 2.6%, mean +/- SD; n = 176) and women (6.3 +/- 2.1%; n = 263). No correlation was detected between the ratio of 20K hGH and age, body height, body weight, or body fat mass in normal subjects. The proportion of 20K hGH was significantly (P < 0.001) higher in patients with active acromegaly (9.2 +/- 2.2%; n = 33) and patients with anorexia nervosa (9.0 +/- 1.9; n = 8), both of which are characterized by chronic elevation of circulating GH levels. The proportion of 20K hGH in successfully treated acromegalic patients did not differ from that in normal subjects, suggesting that GH-producing pituitary tumors secrete a higher proportion of 20K hGH, or that a chronic excess of 22K hGH alters the MCR of 20K hGH. The values in patients with adult GH deficiency, hyperthyroidism, primary hypothyroidism, or GH-independent short stature did not differ from those in normal subjects. The 20K ratio did not change after acute GH provocative tests, such as the insulin tolerance test and the GHRH test. These results suggest that secretion of 20K hGH from the pituitary is under the same control as that of 22K hGH. This new assay may provide a tool for understanding the physiological or pathophysiological role of the 20K hGH isoform.

Acromegaly↗
PubMed1999

Osteo-anabolic effects of human growth hormone with 22K- and 20K Daltons on human osteoblast-like cells.

Human growth hormone with 22,000 Dal (22K-hGH) stimulates proliferation and differentiation of osteoblasts as well as production of interleukin-6 in vitro and bone formation and remodeling in vivo. To investigate whether hGH isoform with 20Kd (20K-hGH), which accounts for 10% of circulating hGH, elicits similar metabolic effects on skeletal tissues, we studied the biological effects of 20K-hGH in cultured human osteoblast-like cells (HOB). HOB were obtained from trabecular bone explants and cultured in alpha-MEM supplemented with 10% FCS. In subconfluent cultures, 22K- and 20K-hGH stimulated [3H]thymidine incorporation by 62 +/- 27% and 63 +/- 23%, respectively (mean +/- SD, n=8, P>0.1). In confluent cultures, 22K- and 20K-hGH increased alkaline phosphatase activity by 38 +/- 23% and 41 +/- 23% (P>0.1), respectively, and increased the osteocalcin concentration in the presence of 10(-9) M 1,25-(OH)2D3 by 50% and 47% (P>0.1), respectively. Furthermore, both hGHs doubled the interleukin-6 (IL-6) concentration in the conditioned medium. RT-PCR analysis revealed that 22K- and 20K- hGH increased IL-6 gene expression 2.2 +/- 0.6 and 2.4 +/- 0.7 -fold, respectively. In summary, we have demonstrated that 20K-hGH elicits equipotent anabolic effects on HOB and stimulates to the same extent the production of IL-6, a cytokine which initiates osteoclastogenesis. These in vitro findings suggest that 22K- and 20K-hGH may equipotently stimulate bone remodeling and elicit anabolic effects on skeletal tissue when administered in vivo.

Bone Development↗
PubMed1999

Papular elastolytic giant cell granuloma: a clinical variant of annular elastolytic giant cell granuloma or generalized granuloma annulare?

A 71-year-old man with asymptomatic red papules on the trunk and upper arms was reported as a case of papular elastolytic giant cell granuloma. A skin biopsy specimen from a papule on the back showed similar findings to those of annular elastolytic giant cell granuloma. However, centrifugal annular lesions were not clinically observed. He was successfully treated with tranilast and topical steroids.

Aged↗
PubMed1999

[Secretin].

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Humans↗
PubMed1998

Prostaglandin E1 suppresses tumor necrosis factor-alpha and interleukin-10 production by lipopolysaccharides-stimulated mononuclear cells.

Prostaglandin E1 has been clinically used in a variety of vascular occlusive diseases. We investigated the in vitro effect of prostaglandin E1 on the synthesis of tumor necrosis factor-alpha, interleukin-1, interleukin-6, interleukin-10 and transforming growth factor beta by human peripheral blood mononuclear cells stimulated with lipopolysaccharides. Prostaglandin E1 significantly suppressed both the mRNA expression and the production of tumor necrosis factor-alpha and interleukin-10 by lipopolysaccharides-stimulated peripheral blood mononuclear cells in a dose-dependent manner (1 x 10(-6)-1 x 10(-8) M). Since tumor necrosis factor-alpha is a potent proinflammatory cytokine involved in certain inflammatory diseases, our findings suggest the possibility to expand the clinical application of prostaglandin E1.

Adult↗
PubMed1998

Differential effect of etretinate on proliferation and extracellular matrix metabolism of human dermal fibroblasts from elderly and young individuals in a novel three-dimensional culture.

The effect of etretinate on proliferation and biosynthesis of collagens and glycosaminoglycans (GAGs) were investigated using human dermal fibroblasts in a novel three-dimensional culture supplemented with L-ascorbic acid 2-phosphate. Fibroblasts from two young and two elderly individuals were studied at different concentrations of etretinate, 0.25, 1.0 and 2.5 microg/ml. Collagens (hydroxyproline) and GAGs (disaccharide units) extracted from the cell layer were analyzed and quantified biochemically by high-performance liquid chromatography (HPLC). Etretinate showed no significant effect on fibroblast proliferation either in the monolayer or the three-dimensional culture. Etretinate increased the collagen or GAGs content in the cell layer, which was prominent at etretinate concentrations of 1.0 and 2.5 or 0.25 microg/ml, respectively in fibroblasts from the elderly (P < 0.05). This effect was not seen in dermal fibroblast from the young. These results suggest that etretinate may have the differential effect on collagen and GAG metabolisms depending on the donor age of the cultured fibroblasts.

Aged↗
PubMed1998

Immunohistochemical distribution of epimorphin in human and mouse tissues.

A novel protein epimorphin has been identified as a mesenchymal signal factor. We reported previously ubiquitous expression of epimorphin in normal skin and a significant increased expression in diseased human skin. The present immunofluorescence study was conducted to determine systematically the distribution of epimorphin in adult human organs with an anti-epimorphin monoclonal antibody. Epimorphin was found to be widely distributed in all human organs examined. It was present in the connective tissue adjacent to or around various epithelial tissues, muscles and vessels. In particular, strong staining was present on the endomysium of muscles, the adventitia of blood vessels, along the sinusoidal lining of hepatocytes and connective tissue around epithelial cells, exocrine and endocrine glands. The results suggest that epimorphin may play a key role in maintaining normal tissue structure and interaction between mesenchymal tissue and epithelial tissue in vivo.

Animals↗
PubMed1998

Opposite effects of tumour necrosis factor-alpha on type I and III collagen gene expression by human dermal fibroblasts in monolayer and three-dimensional cultures.

We have recently established a novel fibroblast culture system supplemented with L-ascorbic acid 2-phosphate. The addition of L-ascorbic acid 2-phosphate enables human dermal fibroblasts to organize a three-dimensional dermis-like structure by accumulating collagens and extracellular matrices. The purpose of this study was to examine the effects of tumour necrosis factor-alpha (TNF-alpha) on collagen gene expression by human dermal fibroblasts in this culture system in comparison with monolayer culture. TNF-alpha suppressed the expression of pro alpha 1 (I) and pro alpha 1 (III) collagen mRNA in monolayer culture. In contrast, their expression was elevated in the three-dimensional culture system. TNF-alpha increased the mRNA expression of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 both in monolayer and three-dimensional culture. These data suggest that responses of human dermal fibroblasts to TNF-alpha are distinct under the different culture conditions. Extracellular matrices may modulate the responsiveness of fibroblasts to TNF-alpha.

Adult↗
PubMed1998

Dermal mast cells in scleroderma: their skin density, tryptase/chymase phenotypes and degranulation.

To determine the distribution, tryptase/chymase phenotypes and degranulation of mast cells (MCs) in the dermis of patients with scleroderma, we examined MC density in the skin of 22 patients with systemic sclerosis (SSc) and 11 with localized scleroderma (LSc). We used antitryptase and antichymase antibodies after Carnoy's fixation. Detailed reports of two representative patients with SSc and LSc are included. In the scleroedematous stage (grade 1) showing oedema in both papillary and reticular dermis with variable homogenization of collagen bundles in the reticular dermis, MC skin density was variable in each specimen although MC skin density, as a whole, was significantly increased as compared with normal skin (P < 0.05). In the sclerotic stage (grade 2) characterized by homogenization of collagen bundles in the entire dermis, MC skin density was significantly decreased as compared with normal skin (P < 0.005). LSc showed changes similar to those in SSc. The ratio of MCTC cells (both tryptase- and chymase-positive MC) to MCT cells (tryptase-positive but chymase-negative MC) was variable in SSc and LSc. MCT cells were exclusively dominant in three patients with SSc and two with LSc. In a patient with SSc (patient 1) showing remarkable perivascular and interstitial oedema in the upper dermis, MC skin density was increased in the oedematous portion and tryptase-positive granules were distributed in extracellular locations. In another patient with LSc (patient 2), tryptase positivity increased and chymase positivity decreased in both number and intensity as the skin sclerosis progressed. MCs must have variable interactions with the lesional skin in SSc and LSc. The present study suggests that MCs are involved in the development of interstitial oedema.

Adult↗