Toshikazu Shimane

Influence of a macrolide antibiotic, roxithromycin, on mast cell growth and activation in vitro

BACKGROUND: Long-term administration of macrolide antibiotics is recognized to be able to favorably modify the clinical condition of inflammatory diseases, such as diffuse panbronchiolitis and cystic fibrosis. However, the precise mechanisms by which macrolide antibiotics could improve clinical conditions of the patients are not well understood. AIM: The present study was designed to examine the influence of macrolide antibiotics on effector cell functions responsible for inflammation through the choice of roxithromycin (RXM) and mast cell. METHODS: Mast cells were induced by long-term culture of splenocytes from BALB/c mice. RXM was added to the cultures at seeding and then every 4-5 days, when the culture medium was replaced with a fresh one. The influence of RXM on mast cell growth was evaluated by counting the number of cells grown on the 16th day. We also examined the influence of RXM on mast cell activation by examining histamine release and inflammatory cytokine secretion. RESULTS AND CONCLUSION: RXM could not inhibit mast cell growth, even when splenocytes were exposed to 100 microg/ml of RXM throughout the entire culture periods. RXM also could not suppress histamine release from cultured mast cells in response to non-immunological and immunological stimulations. However, RXM could suppress inflammatory cytokine, interleukin-1beta, interleukin-6, granulocyte macrophage-colony stimulating factor and tumor necrosis factor-alpha, secretions induced by concanavalin A stimulation at a concentration of as little as 0.5 microg/ml. These results may suggest that RXM modulated the ability of mast cells to secrete inflammatory cytokines and results in improvement of clinical condition of chronic inflammatory diseases.

Suppression of co-stimulatory molecule expressions on splenic B lymphocytes by a macrolide antibiotic, roxithromycin in vitro.

The influence of a macrolide antibiotic, roxithromycin (RXM), on co-stimulatory molecule expression was examined using in vitro cell culture technique. Spleen cells obtained from BALB/c mice 10 days after immunization with 8.0 micrograms of haemocyanin absorbed to 4.0 mg aluminum hydroxide were cultured in the presence of 100.0 micrograms/ml haemocyanin and various concentrations of RXM for 72 h. Low concentrations (1.0 and 2.5 micrograms/ml) of RXM did not influence cell activation induced by antigenic stimulation, whereas RXM showed a suppressive effect on blastic activity of the cells when the agent was added to the cultures at more than 5.0 micrograms/ml. RXM did not affect blastic activity of splenic T cells by anti-CD3 monoclonal antibody stimulation even when the cells were cultured in the presence of 10.0 micrograms/ml RXM. Addition of anti-CD80 and anti-CD86 monoclonal antibody to cell cultures caused significant suppression of cell activation by antigenic stimulation. We next examined the influence of RXM on co-stimulatory molecule expressions on splenic B cells in response to antigenic stimulation. Addition of RXM at a concentration of 5.0 micrograms/ml into cell cultures remarkably suppressed co-stimulatory molecule, CD40, CD80 and CD86, expressions, which enhanced by antigenic stimulation in vitro.

The inhibitory effect of anti-allergic agent suplatast tosilate (IPD–1151T) on methacholine- and allergen-induced bronchoconstriction in sensitized mice

The influence of an anti-allergic agent, suplatast tosilate (IPD-1151T; (+/-)-[2-[4-(3-ethoxy-2-hydroxypropoxy)phenyl-carbamoyl]-ethyl] dimethylsulfonium p-toluenesulfonate) on allergic bronchoconstriction induced by allergen and methacholine (MCh) were examined in mice. BALB/c mice were sensitized by intraperitoneal injection of dinitrophenylated-keyhole limpet hemocyanin (DNP-KLH) mixed with A1(OH)3 (DNP-KLH). IPD-1151T was administered orally once a day for either 5 or 14 days in doses of 10, 30 or 100 mg/kg. Bronchoconstriction was measured 24h after the final drug administration. IPD-1151T inhibited both antigen- and MCh-mediated bronchoconstriction in actively sensitized mice. The inhibition induced was closely related to the dose and frequency of oral administration of the agent. We also examined the effect of IPD-1151T on IgE production in response to DNP-KLH immunization. IPD-1151T inhibited dose-dependently both total and specific IgE concentrations in serum prepared from mice 15 days after immunization. These results strongly indicate that IPD-1151T inhibits IgE production in vivo and results in attenuating effect on bronchoconstriction.

Enhancement of endogenous corticosterone levels by a macrolide antibiotic, roxithromycin in mice.

The influence of roxithromycin (RXM), a macrolide antibiotic, on endogenous corticosterone (CS) levels was examined in BALB/c mice. Mice were sensitized intraperitoneally with two doses of Keyhole Limpet Hemocyanin at 1 week intervals. Mice were given orally 2.5 mg/kg RXM once a day for 14 days starting 7 days after the first sensitization. RXM administration caused markedly increase in endogenous plasma CS levels which was peaked at 60 min after the administration. However, josamycin did not influence on endogenous CS levels in plasma. Injection of dexamethasone inhibits the plasma CS hyperproduction induced by RXM treatment.

Clinicopathological implications of vascular endothelial growth factor 165b expression in oral squamous cell carcinoma stroma

Vascular endothelial growth factor (VEGF) is one of the most important angiogenic factors. VEGF165b was recently isolated as the anti-angiogenic VEGF splice variant. In the present study, we examined the association between VEGF165b expression and clinicopathological characteristics in order to determine how VEGF165b produced from oral squamous cell carcinoma (OSCC) affects the stromal cell biological activity. We examined the relationships between the expressions of both VEGF isoforms in normal human dermal fibroblasts (NHDFs) and OSCC cell lines (HSC2, 3, 4 and SAS). Our analyses indicated that both the mRNA and protein expression levels of VEGF165b in the HSC2 and SAS cells were higher than those in the NHDFs. VEGF165b did not promote cell growth or invasive capabilities, but it induced the cell adhesive capabilities to ECM. Although strong expression of the VEGF165 isoforms in tumor cells of OSCC tissues was observed, there was no significant difference in the VEGF165b expression level among the various degrees of malignancy. OSCC cells secrete VEGF165b into the stroma, and this factor may contribute to the process of anti-angiogenesis by inhibiting gelatinase-expressing cells and activating cell adhesive capabilities to ECM, such as that of fibroblasts surrounding tumor cells.

Tumor Proteins D52 and D54 Have Opposite Effects on the Terminal Differentiation of Chondrocytes

The tumor protein D (TPD) family consists of four members, TPD52, TPD53, TPD54, and TPD55. The physiological roles of these genes in normal tissues, including epidermal and mesenchymal tissues, have rarely been reported. Herein, we examined the expression of TPD52 and TPD54 genes in cartilage in vivo and in vitro and investigated their involvement in the proliferation and differentiation of chondrocytes in vitro. TPD52 and TPD54 were uniformly expressed in articular cartilage and trabecular bone and were scarcely expressed in the epiphyseal growth plate. In MC3T3E-1 cells, the expressions of TPD52 and TPD54 were increased in a differentiation-dependent manner. In contrast, their expressions were decreased in ATDC5 cells. In ATDC5 cells, overexpression of TPD52 decreased alkaline phosphatase (ALPase) activity, while knock-down of TPD52 showed little effect. In contrast, overexpression of TPD54 enhanced ALPase activity, Ca2+ deposition, and the expressions of type X collagen and ALPase genes, while knock-down of TPD54 reduced them. The results revealed that TPD52 inhibits and that TPD54 promotes the terminal differentiation of a chondrocyte cell line. As such, we report for the first time the important roles of TPD52 and TPD54, which work oppositely, in the terminal differentiation of chondrocytes during endochondral ossification.

A case of metastasis to the thyroid gland from lung carcinoma

A case of metastasis to the thyroid gland from lung carcinoma: Toshimitsu Komatsuzaki1), Shunya Egawa1), Ken-ichiro Ikeda1,2), Yukiomi Kushihashi1,2), Yoichi Ikenoya1), Taisuke Hamasaki1), Suguru Furukawa1), Tomomi Mizuyoshi1), Masayo Asano1), Hitome Kobayashi1) and Toshikazu Shimane2,3). 1)Department of Otorhinolaryngology, School of Medicine, Showa University, 2) Head and Neck Oncology Center, School of Medicine, Showa University, 3)Department of Oral Surgery, School of Dentistry, Showa University

Conservative medical treatment of salivary fistulas of post-surgical parotid tumors

対象は，2004年4月から2009年8月までに当科で耳下腺腫瘍の手術を行った178例のうち術後合併症として唾液瘻を併発した8例である。方法は，まず皮下に貯留している唾液を圧迫し手術時の皮膚切開線から排泄させる。唾液の排泄される部位にトレチノイントコフェリル軟膏をすり込むように塗布する。また創部は毎日シャワーにて洗浄し，同軟膏を塗布する。結果として手術から唾液瘻発生までの期間は，6～27日であり，平均12.6日であった。唾液瘻を確認し，本治療法にて治療を開始してから治癒までの期間は，14～31日であり平均17.8日であった。本治療法は，患者のQOLの向上，医療者側の負担を減らすことができると考えられ，今後耳下腺腫瘍手術後の唾液瘻治療の選択肢の一つになると考えられた。