Tetuo Mikami
Toho University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Tetuo Mikami.
Cardiovascular Pathology | 2014
Toshio Kinoshita; Yukio Ishikawa; Michitsune Arita; Yuri Akishima-Fukasawa; Kazuko Fujita; Naomi Inomata; Takeya Suzuki; Atsushi Namiki; Tetuo Mikami; Takanori Ikeda; Junichi Yamazaki; Toshiharu Ishii; Yoshikiyo Akasaka
BACKGROUNDnCardiac fibroblasts (CFs) play a pivotal role in the development of myocardial fibrosis. We previously demonstrated that direct injection of basic fibroblast growth factor (bFGF) into the hypertensive Dahl salt-sensitive (DS) rat heart prevented systolic dysfunction and left ventricular dilation effectively. However, the precise role played by bFGF in fibrotic response of CFs remains unclear. We suggested potential effects of bFGF on the fibrotic response of CFs in vitro.nnnMETHODS AND RESULTSnHistopathologic assessment of cardiac fibrosis demonstrated a marked decline in the extent of perivascular and interstitial fibrosis in bFGF-injected hypertensive DS rat hearts. CFs harvested from the hearts of noninjected DS rats demonstrated a significantly increased messenger RNA (mRNA) expression of matrix metalloproteinase (MMP)-2, MMP-9, and both collagen I and III. In contrast, bFGF treatment in the CFs induced a marked increase in tissue inhibitor of MMP (TIMP)-1 expression and a marked decline in MMP-9 activation. bFGF also induced a decline in α-smooth muscle actin and collagen I and III mRNA expression in the CFs accompanied by inhibited differentiation of CFs into myofibroblasts. Small interfering RNA targeting FGF receptor 1 confirmed a specific interference of the mRNA expression changes elicited by bFGF. In vivo examination confirmed many TIMP-1-positive CFs in perivascular spaces of bFGF-injected hearts.nnnCONCLUSIONSnUp-regulated TIMP-1 expression and down-regulated MMP-9 activation by bFGF in CFs could prevent excessive ECM degradation and collagen deposition in perivascular spaces effectively, leading to prevention of cardiac fibrosis during hypertensive heart failure.nnnSUMMARYnCardiac fibroblasts (CFs) play a pivotal role in myocardial fibrosis. The precise role of CFs in fibrotic response played by growth factors remains unclear. Our results indicates that basic fibroblast growth factor could up-regulate TIMP-1 expression and down-regulate MMP-9 activation in CFs in perivascular spaces, leading to inhibited progression of cardiac fibrosis during hypertensive heart failure.
American Journal of Pathology | 2016
Miho Nakamichi; Yuri Akishima-Fukasawa; Chie Fujisawa; Tetuo Mikami; Kiyoshi Onishi; Yoshikiyo Akasaka
The role of fibrocytes in wound angiogenesis remains unclear. We therefore demonstrated the specific changes in fibrocyte accumulation for angiogesis in basic fibroblast growth factor (bFGF)-treated wounds. bFGF-treated wounds exhibited marked formation of arterioles and inhibition of podoplanin+xa0lymph vessels that were lacking in vascular endothelial growth factor-A-treated wounds. Real-time PCR in bFGF-treated wounds manifested enhanced expression of CD34, CD31, and bFGF mRNA and reduced expression of podoplanin and collagen type I, III, and IV mRNA. Double immunofluorescence staining focusing on fibrocyte detection in bFGF-treated wounds showed increased formation of capillary-like structures composed of CD34+/procollagen I+ fibrocytes, with a lack of capillary-like structures formed by CD45+/procollagen I+ or CD11b+/procollagen I+ fibrocytes. However, vascular endothelial growth factor-A-treated wounds lacked capillary-like structures composed of CD34+/procollagen I+ fibrocytes, with increased numbers of CD34+/fetal liver kinase-1+ endothelial progenitor cells. Furthermore, fibroblast growth factor receptor 1 siRNA injection into wounds, followed by bFGF, inhibited the formation of capillary-like structures composed of CD34+/procollagen I+ fibrocytes, together with inhibited mRNA expression of CD34 and CD31 and enhanced mRNA expression of collagen type I, indicating the requirements of bFGF/fibroblast growth factor receptor 1 system for capillary structure formation. This study highlights the angiogenic properties of CD34+/procollagen I+ fibrocytes specifically induced by bFGF, providing new insight into the active contribution of fibrocytes for vascular formation during wound healing.
Gastric Cancer | 2015
Ippeita Araki; Kei Hosoda; Keishi Yamashita; Natsuya Katada; Shinichi Sakuramoto; Hiromitsu Moriya; Hiroaki Mieno; Akira Ema; Shiro Kikuchi; Tetuo Mikami; Masahiko Watanabe
BackgroundLittle is known about risk factors for recurrence in stage IB gastric cancer without lymph node metastasis. The aims of this study were to determine prognostic factors associated with long-term survival and to clarify patterns of recurrence.MethodsWe retrospectively reviewed the medical records of 130 patients with primary gastric cancer who underwent gastrectomy at Kitasato University East Hospital from 2001 through 2010 and analyzed clinicopathological characteristics associated with survival and patterns of recurrence.ResultsOf the 130 patients, 12 (9.2xa0%) had recurrence, among whom 10 (83xa0%) patients died. Four patients (3.1xa0%) died of other diseases. The 5-year overall survival rate was 89xa0%. Of the 12 patients with recurrence, 7 (58xa0%) had liver metastasis, 3 (25xa0%) had distant lymph-node metastasis, 2 (17xa0%) had peritoneal dissemination, and 1 (8.3xa0%) had locoregional recurrence. Patients with tumors more than 5xa0cm in diameter tended to have recurrence within 1xa0year. Patients who had recurrence more than 2xa0years after surgery tended to survive for longer than 5xa0years after recurrence. Moderate or marked venous invasion (v2 or v3) and age >65xa0years were significantly associated with relapse-free and overall survival on univariate analysis. On multivariate analysis, the only independent prognostic factor for relapse-free and overall survival was venous invasion.ConclusionsModerate or marked venous invasion (v2 or v3) is an independent predictor of relapse-free and overall survival in stage IB node-negative gastric cancer. Postoperative adjuvant chemotherapy, currently not given to this subgroup of patients, may improve the outcomes of patients with stage IB node-negative gastric cancer, particularly when accompanied by venous invasion.
The Annals of Thoracic Surgery | 2016
Takashi Makino; Tetuo Mikami; Yoshinobu Hata; Hajime Otsuka; Satoshi Koezuka; Kazutoshi Isobe; Naobumi Tochigi; Kazutoshi Shibuya; Sakae Homma; Akira Iyoda
BACKGROUNDnThe prognosis for patients with large cell neuroendocrine carcinoma (LCNEC) of the lung is extremely poor, and optimal treatment strategies have not yet been established. To improve prognoses in patients with LCNEC, this study analyzed immunohistochemical expression and gene mutations of several known molecular targets in LCNECs and compared the expression levels of these targets with those in lung adenocarcinomas.nnnMETHODSnTwenty-six patients with primary LCNEC and 40 patients with adenocarcinoma were analyzed. Excision repair cross-complementation group 1 (ERCC1), class III β-tubulin, topoisomerase I, topoisomerase II, epidermal growth factor receptor (EGFR)-L858R, and somatostatin receptor expression were evaluated by immunohistochemistry, and EGFR mutations were evaluated using direct DNA sequencing and the Scorpion-amplified refractory mutation system.nnnRESULTSnIn patients with LCNEC and adenocarcinoma, positive rates of topoisomerase I, topoisomerase II, ERCC1, class III β-tubulin, EGFR-L858R, and somatostatin were 100.0% and 100.0%, 65.4% and 15.0% (pxa0<xa00.0001), 42.3% and 17.5% (pxa0= 0.0462), 46.2% and 62.5%, 0.0% and 20.0% (pxa0= 0.0182), and 50.0% and 5.0% (p < 0.0001), respectively. The frequencies of EGFR mutations were 0.0% and 37.5% in LCNEC and adenocarcinoma (pxa0= 0.0002), respectively. Five-year overall survival rates were 64% in LCNEC and 91% in adenocarcinoma in stage I (pxa0= 0.0132). Multivariate analysis showed that LCNEC histologic type was an independent prognostic factor in stage I.nnnCONCLUSIONSnLCNEC showed overexpression of topoisomerase II, somatostatin, and ERCC1. These findings suggested that it was possible to have good response to treatment with etoposide and octreotide and that LCNEC may be resistant to platinum-based therapy compared with adenocarcinoma. EGFR mutations were not observed in LCNEC. These results may indicate a favorable response to adjuvant treatments that are not typically prescribed for non-small cell lung cancer.
Pathology Research and Practice | 2015
Masaaki Ichinoe; Nobuyuki Yanagisawa; Tetuo Mikami; Kiyomi Hana; Norihiro Nakada; Hitoshi Endou; Isao Okayasu; Yoshiki Murakumo
L-Type amino acid transporter 1 (LAT1) is one of the major amino acid transporters. High levels of LAT1 expression have been reported in various tumors, which can act as a novel prognostic marker. Previously, we demonstrated that LAT1 is highly expressed in advanced gastric carcinoma with lymph node metastasis, and proposed that LAT1 is an independent prognostic factor in non-scirrhous gastric carcinoma. The aim of the present study was to investigate the relationship between LAT1 expression and the size of lymph node metastatic lesions in gastric carcinoma. LAT1 and Ki-67 expression was immunohistochemically analyzed in 64 cases of advanced gastric carcinoma with lymph node metastasis. LAT1 expression in the metastatic lymph nodes was correlated with that in the primary lesions. The high LAT1 expression group showed a larger size of metastatic lesion and a higher Ki-67 labeling index than the low LAT1 expression group. LAT1 expression had a weak association with Ki-67 labeling index and tumor diameter of lymph nodes. These results suggest that LAT1 expression is associated with disease progression in gastric carcinoma. We proposed that LAT1 could be a potential therapeutic target for gastric carcinoma cases with large lymph node metastasis.
Scientific Reports | 2017
Naoko Honma; Shigehira Saji; Tetuo Mikami; Noriko Yoshimura; Seijiro Mori; Yuko Saito; Shigeo Murayama; Nobuhiro Harada
Estrogens play a physiologically important role in the brain, but controversies exist regarding the association between Alzheimer’s disease (AD) and estrogens. Estrogen-related factors were comprehensively examined in frontal lobe tissues from autopsied AD patients, and compared with controls. Concentrations of estrogens, expression of estrogen receptors (ERs), and estrogen-metabolizing enzymes (EMEs) which are important for determining the peripheral estrogen concentrations, were examined using liquid chromatography tandem mass spectrometry, immunohistochemistry, and quantitative real-time PCR, respectively. Body mass index (BMI), known to correlate with the serum estrogen concentrations, was also taken into consideration. There were no significant differences in estrogen concentrations or each EME level between the two groups in both the cortex and white matter, whereas glial nuclear ER-β expression was significantly lower in white matter from the AD group than the control group (Allred score, 3.2u2009±u20090.3 and 6.5u2009±u20090.3, respectively. Pu2009<u20090.0001). Estrogen concentrations were found to closely correlate with BMI, particularly in controls. ER-β loss in the white matter from the AD group suggests the necessity of studying the effects of estrogens on glias as well as neurons in the etiology of AD. The correlation between BMI and estrogen concentrations in the frontal lobe suggests the importance of non-brain sources of estrogens.
Journal of Immunology | 2017
Yuriko Tanaka; Takehiko Sotome; Akiko Inoue; Takanori Mukozu; Taku Kuwabara; Tetuo Mikami; Terumi Kowhi-Shigematsu; Motonari Kondo
Sjögren’s syndrome (SS) is an autoimmune disease in which exocrine tissues are affected by cellular and humoral immunity. As a result, the salivary and lacrimal glands of patients with SS are damaged, leading to xerostomia (dry mouth) and keratoconjunctivitis sicca (dry eyes). Because experimental approaches to investigate SS pathogenesis in human patients are limited, development of a mouse model is indispensable for understanding the disease. In this study, we show that special AT-rich sequence binding protein-1 conditional knockout (SATB1cKO) mice, in which the SATB1 gene is specifically deleted from hematopoietic cells, develop SS by 4 wk of age, soon after weaning. Female mice presented an earlier onset of the disease than males, suggesting that female SATB1cKO mice are more susceptible to SS. T cell–dominant immune cell infiltration was observed in the salivary glands of 4 wk old SATB1cKO mice, and the frequency of B cells gradually increased as the mice aged. Consistently, levels of anti-SSA and anti-SSB Abs were increased around 8 wk of age, after salivary production reached its lowest level in SATB1cKO mice. These results suggest that SATB1cKO mice can be a novel SS model, in which the progression and characteristics of the disease resemble those of human SS.
Human Pathology | 2017
Sachie Kanada; Akira Sugita; Tetuo Mikami; Kenichi Ohashi; Hiroyuki Hayashi
Some case reports of neuroendocrine tumors and neuroendocrine carcinoma associated with ulcerative colitis (UC) have been published. Most neuroendocrine tumor cases are small lesions corresponding to microcarcinoids (MCs). However, published case reports have presented findings of MCs as single-case reports. Thus, the frequency of MCs is still unclear. In this study, we described the clinical and morphological features of 14 cases of UC-associated MCs and estimated the frequency of MCs. Consecutive patients with UC who underwent complete removal of the large intestine were assessed, and 135 patients were selected. Of the 135 cases, 14 cases (10.4%) in which MC lesions were observed histologically were classified as the MC group, and the remaining 121 cases were classified as the control group. Seven cases in the MC group (50%) exhibited colitic cancer. No cases in either group had distinct carcinoid tumors. All MC lesions were located in the rectum, and the sizes ranged from 0.1 to 5.5 mm. Eight cases (57%) had multiple MC lesions. The frequency of MCs in UC was estimated to be 10.4%. Most cases of MC were quite unlikely to develop into clinically distinct carcinoid tumors. Thus, when MC lesions remain microscopic, they may not represent true neoplasms, which require immediate surgical resection. Because MC often arose in cases with UC complicated by dysplasia or cancer, patients with UC whose rectal biopsies reveal MC may be at high risk of colitic cancer.
Oncology Reports | 2018
Kazutoshi Isobe; Atsushi Kakimoto; Tetuo Mikami; Kyohei Kaburaki; Hiroshi Kobayashi; Takahiro Yoshizawa; Yuta Nakano; Takashi Makino; Hajime Otsuka; Go Sano; Keishi Sugino; Susumu Sakamoto; Yujiro Takai; Naobumi Tochigi; Akira Iyoda; Sakae Homma
Molecular mechanisms of programmed death-ligand 1 (PD-L1) mRNA expression and roles of apoptosis and biomarkers are poorly understood in epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma patients. Thirty-three patients with recurrent postoperative EGFR-mutant lung adenocarcinoma (exonxa019 deletion in 16, L858R in 15, G719C in 2 patients) treated with gefitinib were studied. PD-L1 mRNA expression of formalin-fixed paraffin-embedded paratumoral and intratumoral tissues was quantified by PCR. Correlations of PD-L1 mRNA expression with BIM, p53 upregulated modular of apoptosis (PUMA), human epidermal growth factor receptor 2 (HER2), mesenchymal-epithelial transition (MET), EGFR, and vascular endothelial growth factor A (VEGFA) were determined. Eleven of the 33 patients (33.3%) and 14/33 patients (42.4%) expressed intratumoral and paratumoral PD-L1 mRNA, respectively. Patients with intratumoral PD-L1 mRNA expression had significantly higher BIM and lower VEGFA expression compared with paratumoral PD-L1 mRNA patients (P=0.049, P=0.009). PD-L1 mRNA expression was not associated with the expression of PUMA, HER2, EGFR and MET but was positively correlated with BIM expression (r=0.41, P=0.017) and inversely correlated with VEGFA expression (r=-0.33, P=0.043). Patients with intratumoral PD-L1 mRNA expression had significantly shorter median progression-free survival (PFS) after gefitinib therapy compared with no PD-L1 expression (255 vs. 732 days, respectively; P=0.032). Thus, PD-L1 mRNA expression in EGFR-mutant lung adenocarcinoma was associated with BIM and VEGFA mRNA expression and with shorter PFS after gefitinib therapy.
Nephrology | 2018
Hideyo Oguchi; Ken Sakai; Yutaka Yamaguchi; Tetuo Mikami; Tetsuo Nemoto; Yasushi Ohashi; Takeshi Kawamura; Masaki Muramatsu; Yoshihiro Itabashi; Kazunobu Shinoda; Yoji Hyodo; Yusuke Takahashi; Yuki Kawaguchi; Hiroka Onishi; Yuko Hamasaki; Kazutoshi Shibuya; Seiichiro Shishido
The present study was performed to examine the clinicopathological significance of hyaline deposits in the smooth muscle of the interlobular artery (interlobular hyaline arteriopathy [IHA]) in renal allografts.