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H Onuma

Publications and source records attributed to H Onuma.

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

Enhanced expression of SCF in the dermis is a prognostic factor for the regression of urticaria pigmentosa.

Urticaria pigmentosa (UP) is a disorder of mast cell proliferation that occurs in cutaneous tissue. Most patients whose skin manifestations appear in infancy or childhood, experience a resolution of the disease by adolescence. In order to elucidate the relationship between mast cell character and UP prognosis, we used an immunohistochemical approach to examine the expression of stem cell factor (SCF) and c-Kit in the skin of patients with UP. The results revealed intercellular SCF expression throughout the dermis in improving cases. On the other hand, in cases with a tendency to worsen, dermal SCF was recognized only partially or not at all. Regardless of the clinical course, intracellular SCF immunoreactivity of the entire epidermis increased in cases of child onset UP. The c-Kit expression of mast cells in all UP patients showed no relation to clinical features. These findings suggest that SCF in the dermis promotes the differentiation of mast cells infiltrating in UP, and might be an attractive candidate to induce the remission of UP.

Adolescent↗
PubMed1998

Mitogen-activated protein kinase and p70 ribosomal protein S6 kinase are not involved in the insulin-dependent stimulation of cAMP phosphodiesterase kinase in rat adipocytes.

To elucidate the mechanism of anti-lipolytic action of insulin in rat epididymal adipocytes, we explored the potential mechanism that might be involved in the hormone-dependent stimulation of cAMP phosphodiesterase (PDE) kinase. PDE kinase was assayed in a cell-free system. Both wortmannin and LY294002, highly specific inhibitors of phosphatidylinositol 3-kinase, almost completely blocked the hormonal effect not only on PDE kinase but also on mitogen-activated protein (MAP) kinase. Neither PD98059, a specific inhibitor of MAP kinase, nor rapamycin, a potent inhibitor of insulin-dependent stimulation of p70 ribosomal protein S6 kinase (p70S6K), had inhibitory effect on that of PDE kinase. These results are consistent with the view that (i) insulin-activated PDE kinase as well as MAP kinase and p70S6K are localized downstream of phosphatidylinositol 3-kinase, (ii) PDE kinase is distinct from either MAP kinase or p70S6K and (iii) PDE kinase does not exist downstream of either MAP kinase or p70S6K. It is suggested that PDE kinase and MAP kinase or p70S6K may be localized in separate branches of the cascade of insulin action. The branching point of the cascade could be either at or below the level of phosphatidylinositol 3-kinase.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1998

A calcineurin inhibitor, FK506, blocks voltage-gated calcium channel-dependent LTP in the hippocampus.

The effects of FK506, an immunosuppressant and protein phosphatase 2B (calcineurin) inhibitor, on the voltage-gated calcium channel (VGCC)-dependent long-term potentiation (LTP) were investigated in the CA1 region of mice hippocampal slices. VGCC-dependent LTP was induced either by a brief application of a potassium channel blocker tetraethyleneanmonium (TEA), or by a strong tetanic stimulation under the blockade of NMDA-receptors. FK506 (1-50 microM) produced dose-dependent inhibition on TEA-induced LTP. Cyclosporin A (CysA 50 microM), another calcineurin inhibitor, showed a similar inhibitory effect on TEA-induced LTP. FK506 (10 microM) also blocked the strong tetanus-induced LTP, but had no effect on the post-tetanic potentiation. By using a subthreshold weak tetanic stimulation protocol, we also found that low concentration of FK506 (1 microM) produced neither inhibition nor potentiation on VGCC-dependent LTP. These results showed FK506 and CysA exerted inhibitory effects on VGCC-dependent LTP, and suggest that calcineurin is involved in the processes of this kind of synaptic plasticity.

Animals↗
PubMed1997

Effects of vasopressin and involvement of receptor subtypes in the rat central amygdaloid nucleus in vitro.

Effects of arginine-vasopressin (AVP) on neurons in the central amygdaloid nucleus (ACe) were investigated with rat brain slice preparations using extracellular recording methods. Of 160 ACe neurons tested, 70 cells (44%) were excited and 9 cells (6%) were inhibited by bath application of AVP at 3 x 10(-7) M. The excitatory effects of AVP were dose-dependent and the threshold concentration was approximately 10(-10) to 10(-9) M. The excitatory effects of AVP persisted under blockade of synaptic transmission by perfusing with Ca2+-free and high-Mg2+ medium, whereas the inhibitory effects were abolished by synaptic blockade. AVP-induced effects were mimicked by a V1-receptor agonist and completely blocked by a selective V1-antagonist. V2-agonist produced no effects on ACe neurons and V2-antagonist had no effect on AVP-induced excitation. These results showed that the excitatory effect of AVP on ACe neurons was produced by a direct action through the V1-receptors, whereas the inhibitory response of ACe neurons to AVP seemed to be produced by an indirect action. The results of this study suggest that AVP is involved in the amygdala-relevant functions as a neurotransmitter or a neuromodulator.

Amygdala↗
PubMed1994

Association of HLA-DPB1*0501 with early-onset Graves' disease in Japanese.

To investigate the association between HLA antigens and Graves' disease among Japanese, serologic typing and DPB1 genotyping using the PCR-RFLP method have been performed. HLA alleles of 106 patients with Graves' disease were determined, and the frequency of HLA-B46 was found to be significantly increased. Furthermore, the frequencies of HLA antigens were compared between two age groups: early-onset and late-onset patients (under and over 20 years, respectively). It was found that the frequency of DPB1*0501 (88.9%) was significantly increased (pc < 0.004) in the early-onset group as compared with the healthy controls (55.0%) but not in the late-onset group (60.7%). On the other hand, a significant increase of HLA-B46 was observed in the late-onset patients (pc < 0.0004). These results suggest that the genetic background of Japanese patients with early-onset Graves' disease is different from late-onset patients. Namely, the HLA-DP allele (DPB1*0501) and the HLA-B allele (B46) are primarily involved in the pathogenesis of early-onset and late-onset Graves' disease in Japanese, respectively.

Adolescent↗
PubMed1994

Significance of values of thyrotropin binding inhibitor immunoglobulins and appearance of intrathyroidal lymphocytes at subtotal thyroidectomy for Graves' disease.

This study was undertaken to investigate whether thyrotropin binding inhibitor immunoglobulins (TBII) values at and after subtotal thyroidectomy correlated with the outcome or the histologic grade applied to the appearance of intrathyroidal lymphocytes at the time of surgical treatment. In addition, the main reason for the study was to determine whether or not it was possible to predict the outcome after the operation by the data obtained. There was no relation between the TBII results and the grade of the appearance of intrathyroidal lymphocytes at the time of operation or the TBII postoperative results (whether positive or negative) and the final outcome. However, it was of interest that patients with a recurrence of hyperthyroidism had the TBII values of more than 50 percent at the time of surgical treatment, and also manifested continuously positive TBII values after the operation. They also had moderate grades of lymphocytic infiltration and lymph follicle formation in the surgical specimen. It seemed impossible to predict the outcome of each instance in accordance with TBII values and the grade of the appearance of intrathyroidal lymphocytes at the time of the operation. However, it might be possible to predict at least the recurrence of hyperthyroidism by the consideration of changes of TBII values postoperatively.

Adolescent↗
PubMed1993

Development of hypothyroidism with thyroid stimulation blocking antibody long after treatment with antithyroid drugs in a patient with hyperthyroid Graves' disease: a case report.

We observed a patient manifesting spontaneous hypothyroidism with thyroid stimulation blocking antibody (TSBAb) long after treatment with antithyroid drugs (ATDs) for hyperthyroid Graves' disease. A 19-year-old female with Graves' disease was treated with ATDs for approximately 2 years; after cessation of ATDs, hyperthyroidism did not recur. Nine years later, she was again seen in our hospital because of symptoms indicative of hypothyroidism. Thyroid hormone replacement was commenced after laboratory confirmation of hypothyroidism. TSH-binding inhibitor immunoglobulin and TSBAb were both positive, while thyroid stimulating antibody (TSAb) was negative, at the time of diagnosis of hypothyroidism. These results indicated that the alterations in thyroid function in this patient appeared to relate to the presumed decline in the activity of TSAb and the appearance of TSBAb years after ATDs administration had been discontinued.

Adult↗
PubMed1993

AS-183, a novel inhibitor of acyl-CoA: cholesterol acyltransferase produced by Scedosporium sp. SPC-15549.

A novel compound, AS-183, which inhibits acyl-CoA: cholesterol acyltransferase (ACAT), was isolated from the culture broth of a fungus, Scedosporium sp. SPC-15549. AS-183 inhibited ACAT activity in an enzyme assay system using rabbit liver microsomes with an IC50 value of 0.94 microM. AS-183 also inhibited cholesterol ester formation in HepG2, CaCo2, and THP-1 cells with IC50 values of 18.1, 25.5, and 34.5 microM, respectively.

Animals↗
PubMed1993

Clinical evaluation of upper mediastinal dissection for differentiated thyroid carcinoma.

BACKGROUND: An extensive upper mediastinal dissection in advanced differentiated thyroid carcinoma is occasionally required. This investigation was undertaken to clarify the indications for mediastinal lymph node dissection and the route of upper mediastinal metastases. METHODS: Twenty-one patients with differentiated thyroid cancer, who underwent their first radical operations with mediastinal dissection through a partial midline sternotomy, were enrolled in this study. Of 21 patients, 10 (48%) were found to have mediastinal lymph node metastases. RESULTS: The tumor size in the group with metastatic disease was much bigger than that in the group without metastatic disease. Histologic type and age were similar between the two groups. The extent of cervical lymph node metastases was more significant in the group with metastatic disease; in particular, all 10 patients showed more than two metastatic nodes along the internal jugular vein of the tumor-free side. CONCLUSIONS: This study indicates that metastases to the internal jugular chain on the side contralateral to the primary tumor would be an extremely important factor for indication of extensive upper mediastinal lymph node dissection after median partial sternotomy in patients with differentiated thyroid carcinoma.

Adolescent↗
PubMed1989

Luteal hypoplasia and in vitro granulosa cells proliferation in cows.

Two groups of cows were set up. In one group ovulation was induced, leading to luteal hypoplasia (FSH non-injection group or group 1). In the other group ovulation was induced and FSH injected simultaneously to improve luteinization (FSH injection group or group 2). Granulosa cells were collected from the ovarian follicles of the cows of the two groups immediately before ovulation. Their ability to proliferate and secrete progesterone in vitro was compared between the two groups. Granulosa cells proliferated in vitro more rapidly in group 2 than in group 1. Therefore, FSH injection was proved to be very effective for the proliferation of these cells. Cultured granulosa cells showed the same morphology, regardless of the FSH injection. They presented changes from fibroblast-like cells to epithelioid cells after adhering to a coverslip. They were transformed to epithelioid cells, however, earlier in group 2 than in group 1. Their ability to secrete progesterone in vitro was essentially the same between the two groups. Progesterone secretion decreased gradually in amount in both groups with the advance in culture. Therefore, it was considered that luteal hypoplasia might have been caused by a low ability of granulosa cells, which would be transformed to lutein cell, to proliferate.

Animals↗
PubMed1989

[A case of tubular adenoma of the breast preoperatively suspected to be an advanced cancer].

A very rare case of a tubular adenoma of the breast is reported. The patient, 59-year-old woman, was admitted to hospital because of a large, left breast tumor. The tumor, 11 cm in diameter, was adhered to the surface skin. Because a malignancy was suspected, an incisional biopsy was first carried out. A pathologic examination revealed it to be a tubular adenoma, and a simple mastectomy was chosen as the operative procedure because a latent malignancy was not ruled out. The removed tumor was grossly cystic and a histological examination supported the finding that it was a non-malignant tubular adenoma.

Adenoma↗
PubMed1982

Xanthic variant of non-ossifying fibroma (so-called xanthofibroma) of the mandible. An ultrastructural study.

An unusual case of a 37-year-old female with xanthomatous bone tumor of the right molar area of the mandible was presented. The tumor was asymptomatic and found to be a well-demarcated intraosseous radiolucent lesion on radiographic examination. Histologically the tumor consisted of two cell types, fibroblastic and xanthomatous cells. There was no osteoid, bone or cartilage formation. However, numerous psammomatous calcified bodies were seen in the fibrous area. Ultrastructural study showed fibroblastic cells in different stages of proliferation as the basis of the tumor which transform itself into xanthomatous cells. From the clinicopathologic findings, our case was thought to be a xanthic variant of non-ossifying fibroma (so-called xanthofibroma) of the mandible.

Adult↗