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K Ito, Y Fukabori, Y Shibata, K Suzuki, M Mieda, K Gotanda, S Honma and H Yamanaka

OBJECTIVE: It has been known for many years that human benign prostatic hyperplasia (BPH) is composed predominantly of hyperplastic stromal cells rather than epithelial cells. In the present study the effects of a new steroidal aromatase inhibitor on hormone-induced and spontaneous canine BPH were investigated. METHODS: (1) Effects of TZA-2237 on hormone-induced canine BPH. Ten castrated beagles were administered testosterone and androstenedione 6 days/week for 8 months, and divided randomly into three groups after 2 months of treatment as follows. Group I served as controls, Group II was given 0.5 and Group III was given 2.5 mg/kg/day TZA-2237 5 days/week for 6 months. (2) Effects of TZA-2237 on spontaneous canine BPH. Twenty aged beagles with BPH were divided into five groups, Group IV was untreated, Group V was treated with 1 and Group VI with 5mg/kg/day TZA-2237 5 days/week for 31 weeks. Group VII was treated with 5mg/kg/day Atamestane and Group VIII was treated with 0.3 mg/kg/day chlormadinone acetate (CMA) 5 days/week. (3) Effects of TZA-2237 combined with CMA on spontaneous canine BPH. Three aged beagles with BPH were treated with 1mg/kg/day TZA-2237 and 0.03 mg/kg/day CMA 5 days/week for 20 weeks (Group IX) and a further three aged beagles with BPH were treated with 0.3 mg/kg/day CMA alone 5 days/week (Group X). RESULTS: Hormone-induced prostatic growth was significantly suppressed in group III compared with that in other groups. In Group III, the intraprostatic aromatase activity, estradiol level and androgen receptor content decreased significantly in comparison with the values in Group I. The prostatic weights in Groups V, VI and VII increased significantly in comparison with the weight in Group IV. Serum LH and testosterone levels in Groups V, VI, and VII increased significantly in comparison with the level in Group IV. The prostatic weight in Group IX was decreased only slightly, but the smooth muscle component was decreased significantly. CONCLUSIONS: TZA-2237 is a new, unique and effective aromatase inhibitor that causes inhibition of both epithelial and stromal compartments in hormone-induced canine BPH. Dual inhibition of androgen and estrogen resulted in inhibition of smooth muscle growth, and should prove effective as a new method of treatment given the atrophic effects on not only the epithelium but also the stroma in human BPH.

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R Takeda, T Yamazaki, Y Ito, H Koshida, T Morise, I Miyamori, T Hashimoto and S Morimoto

A case of primary aldosteronism treated with spironolactone therapy has been followed up for 24 years. This is probably the longest case of spironolactone therapy for primary aldosteronism that has ever been reported. Long-term treatment with spironolactone controlled the hypertension and prevented hypokalemic alkalosis in this patient, without any deleterious effects on steroid biosynthesis. Based on data obtained during dose reduction and subsequent withdrawal of spironolactone, it is suggested that the suppressed plasma renin activity associated with adenoma-induced aldosteronism develops prior to hypokalemia and hypertension.

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J Tani, K Mori, S Hoshikawa, T Nakazawa, J Satoh, Y Nakagawa, S Ito and K Yoshida

OBJECTIVE: Interferon regulatory factor-1 (IRF-1) is a critical regulator of interferon-gamma(IFNgamma)-mediated immune responses. To determine whether IRF-1 is involved in the pathogenesis of thyroiditis in animal models, we evaluated the incidence of iodide-induced lymphocytic thyroiditis (LT) in non-obese diabetic (NOD) mice lacking IRF-1 as well as IRF-1 +/+ and +/- mice. DESIGN: IRF-1 +/+, +/- and -/- NOD mice at 6 weeks of age were fed water (group 1) or iodide water (group 2) for 8 weeks. METHODS: Thyroids were examined histopathologically and intrathyroidal lymphocytic infiltration was arbitrarily graded. Serum thyroxine (T(4)) and anti-mouse thyroglobulin antibody (anti-mTgAb) levels were measured. Spleen cell population was analyzed by flow cytometry, and IFNgamma and interleukin-10 produced by splenocytes were measured by enzyme-linked immunosorbent assay. RESULTS: In group 1, only 4.3% of NOD mice developed LT. In contrast, 67.6% of mice in group 2 developed the disease. Iodide treatment induced LT in more than 80% of IRF-1 +/+ and +/- mice. However, no IRF-1 -/- mice in group 2 developed LT. There was no difference in both serum anti-mTgAb and T(4) levels among the three IRF-1 genotypes of NOD mice. Numbers of splenic CD8(+) T cells and IFNgamma production by Concanavalin A-stimulated splenocytes were markedly decreased in IRF-1-deficient NOD mice. CONCLUSIONS: IRF-1 is involved in the development of iodide-induced LT in NOD mice.

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H Tokuda, M Niwa, H Ito, Y Oiso, K Kato and O Kozawa

OBJECTIVE: We have reported that endothelin-1 (ET-1) activates p38 mitogen-activated protein (MAP) kinase through protein kinase C in osteoblast-like MC3T3-E1 cells, and that p38 MAP kinase plays a role in the ET-1-induced heat shock protein 27 (HSP27). Recently, we found that stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) is activated by ET-1 in these cells. In the present study, we have investigated the involvement of SAPK/JNK in ET-1-induced HSP27 in MC3T3-E1 cells. METHODS: The concentration of HSP27 in soluble extracts of the cells, the expression of mRNA for HSP27, and the phosphorylation of SAPK/JNK were determined by an enzyme immunoassay, Northern blot analysis, and Western blot analysis respectively. RESULTS: SP600125, a specific inhibitor of SAPK/JNK, markedly reduced ET-1-stimulated HSP27 accumulation. The inhibitory effect of SP600125 was dose dependent in the range between 1 and 50 microM. SP600125 reduced the ET-1-increased level of HSP27 mRNA. Calphostin C and Go 6976, inhibitors of protein kinase C, reduced the ET-1-induced phosphorylation of SAPK/JNK. 12-O-Tetradecanoylphorbol-13-acetate, a direct activator of protein kinase C, induced SAPK/JNK phosphorylation, which was suppressed by SP600125. A combination of SP600125 and p38 MAP kinase inhibitor such as SB203580 and PD169316 additively reduced the ET-1-stimulated accumulation of HSP27. CONCLUSIONS: These results strongly suggest that JNK plays a part in ET-1-induced HSP27 in addition to p38 MAP kinase in osteoblasts.

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A. Kawakami, K. Eguchi, M. Matsunaga, H. Tezuka, Y. Ueki, C. Shimomura, T. Otsubo, H. Nakao, K. Migita, N. Ishikawa, K. Ito and S. Nagataki


Previously, we used dual immunofluorescent analysis and showed that the thyroid gland from patients with Graves' disease had a reduced number of CD4+CD45RA+ cells, but an increased number of complementary CD4+CDw29+ cells. An immunohistochemical study, however, produced opposite results; interstitial lymphocytes predominantly expressed the CD45RA+ rather than the CDw29+ phenotype. Because the difference in findings may be due to differences in the techniques used, we did the following experiments: Mononuclear cells were treated with various amounts of collagenase (50-1000 mg/l) which had no effect on the cell surface antigens CD3, CD4 and CD45RA. A dual immunofluoresent study showed that the numbers of CD4+CD45RA+ and CD8+CD45RA+ cell population among CD45RA+ cell population were markedly decreased in the thyroid tissue, and that the CD45RA antigen on the intrathyroidal mononuclear cells was mainly expressed on the CD20+ cells. As the thyroid section had been fixed with acetone before immunohistochemical staining, CD45RA cells were treated with acetone and stained with anti-CD45RA monoclonal antibody using an avidin-biotin peroxidase complex method. The results of this experiment suggest that there are cell surface molecules which react with anti-CD45RA monoclonal antibody after treatment with acetone in CD45RA cells. The above findings confirm our previous results which showed that the thyroid glands of patients with Graves' disease have decreased numbers of suppressor-inducer T cells. Also, several problems exist in the detection of CD45RA+ cells when using an immunohistochemical method.