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Biomedical subjects

S Takayasu

Publications and source records attributed to S Takayasu.

At least 37 records · Page 2Linked to original sources
PubMed1999

Heterogeneity in expression of cytokine mRNA in freshly isolated peripheral blood eosinophils of patients with cutaneous-disease-associated eosinophilia.

BACKGROUND: It is thought that there are subpopulations of eosinophils concerning cytokine production: some of them predominantly produce Th1 cytokines, while others produce Th2. METHODS: By semiquantitative RT-PCR, the in vivo levels of the cytokine mRNA were measured in freshly isolated eosinophils and peripheral blood mononuclear cells (PBMCs) of 19 patients with eosinophilia, including 6 with atopic dermatitis, 4 with drug eruption, 1 with chronic dermatitis, 2 with erythroderma, 3 with bullous pemphigoid, 1 each with urticaria, adult T cell lymphoma, and hypereosinophilic syndrome, and 7 healthy individuals. Eosinophils and PBMCs were isolated by centrifugation over Ficoll-Paque and magnetic cell separation using anti-CD16 antibody. RESULTS: The IL-4/IFN-gamma ratio in eosinophils as well as PBMCs was increased and correlated well with IgE levels in atopic dermatitis. In other cytokines, such as IL-8, TNF-alpha and TGF-beta1, the levels of mRNA expression were variable among each sample. CONCLUSION: Not only helper T lymphocytes but also eosinophils may take part in the pathogenesis of cutaneous diseases by virtue of heterogeneity of Th1 and Th2 cytokine production.

Adult↗
PubMed1998

Growth stimulation of normal melanocytes and nevocellular nevus cells by gastrin releasing peptide (GRP).

In order to know the possible effects of gastrin releasing peptide (GRP) on nevus cells and melanocytes, we studied the effect of GRP on the proliferation of cultured human nevus cells and normal melanocytes. MTS assay showed that GRP stimulated the growth of viable melanocytes at 1000 ng/ml. GRP also stimulated the growth of nevus cells in a dose dependent manner and maximum stimulation was obtained at 100 ng/ml of GRP. GRP was less effective for growth stimulation of normal melanocytes than nevus cells. The cytoplasm of nevus cells were positively stained by polyclonal anti-GRP antibody. We also detected the expression of GRP and GRP receptor mRNAs in these cells by RT-PCR. These results suggest that GRP acts as an autocrine growth factor for nevus cells and normal melanocytes.

Cell Division↗
PubMed1998

Predominance of type I 5alpha-reductase in apocrine sweat glands of patients with excessive or abnormal odour derived from apocrine sweat (osmidrosis).

High levels of 5alpha-reductase activity have been detected in human apocrine glands, and the concentration of dihydrotestosterone has been found to be higher than that of testosterone in the nuclear fraction of the skin of patients who suffer from excessive or abnormal odour derived from apocrine sweat (osmidrosis). Although these results suggest that 5alpha-reductase may play a central role in the action of androgens in the apocrine gland, the isozyme responsible is not known. We therefore assayed 5alpha-reductase type I and type II activity and mRNA expression in isolated apocrine glands from four patients with osmidrosis. When we incubated gland homogenates with [3H]testosterone, we found that the biochemical properties of the apocrine gland enzyme were consistent with those of type I 5alpha-reductase: at substrate concentrations of both 50 nmol/L and 1 micromol/L, the optimum pH was in the range 6.0-7.5, and the apparent Km was 21.1 micromol/L. The apocrine gland enzyme was inhibited by MK386, a specific inhibitor of type I 5alpha-reductase, in a dose-dependent manner, but it was hardly affected by finasteride, a specific inhibitor of type II isozyme, in that a nanomolar concentration of finasteride produced only a slight inhibition. Reverse transcriptase-polymerase chain reaction showed that the apocrine gland expressed type I 5alpha-reductase mRNA exclusively, except for a faint band of type II isozyme in a few preparations. These data indicate that the type I isozyme is the predominant form of 5alpha-reductase in the apocrine gland and may play a central role in the anabolic activity of androgens, as reported for the sebaceous gland. In addition, a small amount of type II isozyme may be expressed by mesenchymal cells that surround the apocrine glands and also contribute to their development.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1998

Merkel cell carcinoma: report of three cases.

Three cases of Merkel cell carcinoma are reported: Case 1 on the upper eyelid with regional lymph node metastasis, Case 2 with spontaneous regression after repeated biopsies, and Case 3 presumably developing on the lesion of pre-existing Bowen's disease. In Case 2, the biopsy specimen was characterized by numerous apoptotic cells in the periphery of the tumor nests surrounded by lymphocytic infiltration. In Case 3, the tumor developed after injury to the pre-existing lesion of Bowen's disease.

Aged↗
PubMed1998

A case of rudimentary meningocele.

A 2-year-old girl had an alopecic, atrophied macule on the midline of the occipital area. X-ray and CT scan of the scalp revealed no underlying bone defect. Histologically, the whole dermis and subcutis showed dense, hyalinized collagen bundles intermingled with cuboidal, epithelioid cells that surrounded pseudovascular spaces or gathered in clusters. These flattened or cuboidal cells were positive for anti-vimentin antibody; some of them were also positive for an anti-epithelial membrane antigen antibody, but negative for antifactor VIII-related antigen and Ulex europaeus I lectin.

Child, Preschool↗
PubMed1997

Increased levels of IL-13 mRNA, but not IL-4 mRNA, are found in vivo in peripheral blood mononuclear cells (PBMC) of patients with atopic dermatitis (AD).

Previous studies using in vitro systems with various stimuli have shown that PBMC from patients with AD show increased levels of IL-4 but decreased levels of interferon-gamma (IFN-gamma) compared with PBMC from normal controls. However, in vitro conditions do not always mimic the in vivo condition. We therefore believe that it is important to quantify the expression of these cytokines in freshly isolated PBMC. This study examines the expression of IFN-gamma, IL-4 and IL- 13 mRNA in freshly isolated PBMC from adult patients with AD, from patients with psoriasis vulgaris and from healthy adults, using the semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) method. Levels of IFN-gamma mRNA were significantly lower in PBMC of patients with AD than in controls. IL-4 mRNA levels did not differ significantly between groups. Conversely, levels of mRNA for IL-13 were significantly greater in PBMC of patients with AD than in controls. An increase in IL-13 expression may regulate the in vivo synthesis of IgE in patients with AD.

Adolescent↗
PubMed1997

Human genital melanocytes as androgen target cells.

As some parts of human skin - such as genital and areolar skin - become pigmented after puberty, melanocytes in these regions are thought to be sex hormone target cells. We immunohistochemically localized androgen receptors in the nuclei of cultured human genital melanocytes by monoclonal and polyclonal antibodies. When these cells were incubated with [1,2-3H]-testosterone, the major metabolite in the medium was dihydrotestosterone and 5alpha-reduction predominated over 17beta-oxidation. Androgen receptor and type I 5alpha-reductase mRNAs could be detected in genital melanocytes by reverse transcriptase polymerase chain reaction. The tyrosinase activity was stimulated by the addition of androgen. This stimulation was antagonized by cyproterone acetate, whereas tyrosinase mRNA expression was not affected by androgen. These results indicate that human genital melanocytes are androgen target cells, and that androgen plays a role for pigmentation in the specific regional skin after puberty.

17-Hydroxysteroid Dehydrogenases↗
PubMed1997

Dermatomyositis associated with primary intramuscular B cell lymphoma.

A rare case of dermatomyositis associated with primary intramuscular malignant lymphoma is described. A 40-year-old Japanese woman noticed swelling of the right thigh during the treatment of dermatomyositis with prednisolone, azathioprine and cyclophosphamide. A biopsy specimen taken from the right quadriceps muscle revealed infiltration of lymphoma cells which were positive for CD20. We reviewed 12 cases of dermatomyositis associated with malignant lymphoma reported in Japanese literature between 1984 and 1996.

Adult↗
PubMed1997

Perineural and neural involvement in skin cancers.

BACKGROUND: Malignant skin tumors rarely spread along nerves. Complete resection of involved nerves is often unsuccessful. OBJECTIVE: In the treatment of tumors with perineural invasion, surgeons should accurately estimate the extent of distant spread. METHODS: We report six cases of skin cancers, including two basal cell carcinomas, two squamous cell carcinomas, and two neurotropic malignant melanomas, that invaded nerve or perineural spaces. RESULTS: In three of the cases, the tumors developed on the face and involved the infraorbital nerves or its branches. Two patients suffered from tumors on old burn scars of lower legs. Branches of posttibal nerves were involved in both cases. In the last case, tumor invasion of a branch of the greater occipital nerve was detected. CONCLUSION: The extent of surgical excision should include the area of skin supplied by the affected nerve, which must be resected in continuity.

Adult↗
PubMed1997

In vivo expression of IL-4, IL-5, IL-13 and IFN-gamma mRNAs in peripheral blood mononuclear cells and effect of cyclosporin A in a patient with Kimura's disease.

Semiquantitative reverse transcription-polymerase chain reaction was used to analyse the expression of cytokine mRNAs in freshly isolated peripheral blood mononuclear cells obtained from a patient with Kimura's disease. The patient was treated with cyclosporin A (CsA) after incomplete tumour resection and irradiation of lesions. Levels of interleukin (IL)-4, IL-5 and IL-13 mRNA were elevated and the level of interferon (IFN)-gamma mRNA was within normal limits before treatment. The levels of IL-4, IL-5 and IL-13 mRNA, the number of eosinophils, and the serum level of IgE decreased markedly after surgery and radiation therapy. CsA treatment suppressed these values in a dose-dependent manner, but had a minimal effect on the level of IFN-gamma mRNA. The number of peripheral eosinophils decreased in association with decreases in the levels of IL-4, IL-5 and IL-13 mRNAs during CsA therapy; the serum level of IgE remained low during therapy and did not fluctuate in association with changes in cytokine levels. These results suggest the Th2 cytokines play a part in the development of Kimura's disease and that CsA suppresses the activity of this disease.

Aged↗