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Dive into the research topics where Satoshi Tamada is active.

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Featured researches published by Satoshi Tamada.


Transplantation | 2002

Magnesium supplementation prevents experimental chronic cyclosporine a nephrotoxicity via renin-angiotensin system independent mechanism.

Toshihiro Asai; Tatsuya Nakatani; Shinya Yamanaka; Satoshi Tamada; Taketoshi Kishimoto; Koichiro Tashiro; Takafumi Nakao; Mikio Okamura; Shokei Kim; Hiroshi Iwao; Katsuyuki Miura

Background. We have previously shown that correction of hypomagnesemia by magnesium (Mg) supplementation ameliorates chronic cyclosporine A (CsA) nephropathy via inhibiting gene expression of fibrogenic molecules. Experiments were conducted to further elucidate upstream mechanism of the beneficial effects upon CsA nephrotoxicity. Methods. CsA (15 mg/kg/day, subcutaneous [SC]) was administered daily to rats maintained on low sodium diet for 7, 14, and 28 days. Because blockade of renin-angiotensin system improves chronic CsA nephropathy, the effects of Mg supplementation and those of angiotensin-converting enzyme inhibitor (ACEI) were compared on renal function, renal histology, mononuclear cell infiltration, and gene expression profile. Results. CsA induced a decline in glomerular filtration and developed characteristic striped fibrosis that were mostly evident at day 28. Mg attenuated CsA-induced impaired renal function, whereas ACEI did not. Interstitial inflammation as evidenced by monocyte/macrophage infiltration preceded the renal fibrosis and increased progressively with the CsA treatment period. Concomitantly, CsA markedly up-regulated expression of chemoattractant proteins, osteopontin, and monocyte chemoattractant protein-1. These changes were abolished by Mg but were only partially affected with ACEI. CsA promoted renal mRNA expression of fibrogenic molecules and extracellular matrices that were almost completely abolished by Mg but partially suppressed by ACEI. Similarly, CsA-induced chronic fibrotic lesion was markedly attenuated by Mg supplementation but was partially attenuated by ACEI. Conclusion. Mg supplementation abolished CsA-induced precedent interstitial inflammation possibly via inhibition of chemoattractants expression and consequently attenuated tubulointerstitial fibrosis. In this protective mechanism, factors independent of the renin-angiotensin system appears to be mainly involved.


Transplantation | 2002

Role of hypomagnesemia in chronic cyclosporine nephropathy

Katsuyuki Miura; Tatsuya Nakatani; Toshihiro Asai; Shinya Yamanaka; Satoshi Tamada; Koichiro Tashiro; Shokei Kim; Mikio Okamura; Hiroshi Iwao

BACKGROUND Hypomagnesemia is a common finding of cyclosporine (CsA)-treated patients and has been proposed as both a cause and a consequence of CsA-induced nephrotoxicity. This experiment was conducted to elucidate the role of hypomagnesemia in the pathogenesis of chronic CsA nephropathy. METHODS CsA (15 mg/kg/day subcutaneously) was administered to rats maintained on a low-sodium diet for 1, 2, and 4 weeks, and the effects of magnesium (Mg) supplementation on renal function, renal histology, and renal gene expression profile of fibrogenic molecules and vasoconstrictors was examined. RESULTS CsA elicited hypomagnesemia and induced a progressive decline in glomerular filtration. At 28 day, renal tubular atrophy and cortical striped interstitial fibrosis were evident with CsA treatment. Dietary supplementation of Mg ameliorated CsA-induced hypomagnesemia and almost completely abolished CsA-induced chronic fibrotic lesions. Neither CsA nor Mg supplementation affected blood pressure. Renal cortical mRNA of transforming growth factor beta, plasminogen activator inhibitor (PAI)-1, and extracellular matrix started to increase at 14 days and elevated further at 28 days. In contrast, the increase in mRNA of tissue inhibitor of matrix metalloproteinase-1 and renin was evident early at 7 days and reached peak at 14 days. These mRNA increases, except that of renin, were almost abolished when hypomagnesemia was corrected. Magnesium supplementation also improved glomerular dysfunction, at least in part, through inhibition of up-regulated mRNA of endothelin-1. CONCLUSION CsA-induced hypomagnesemia contributes to chronic renal fibrotic lesions seen during CsA treatment through up-regulation of fibrogenic molecules, most notably early activation of tissue inhibitor of matrix metalloproteinase-1 expression.


Transplantation | 2003

Activation of transcription factors AP-1 and NF-κB in chronic cyclosporine a nephrotoxicity: Role in beneficial effects of magnesium supplementation

Toshihiro Asai; Tatsuya Nakatani; Satoshi Tamada; Nobuyuki Kuwabara; Shinya Yamanaka; Koichiro Tashiro; Takafumi Nakao; Toshiyuki Komiya; Mikio Okamura; Shokei Kim; Hiroshi Iwao; Katsuyuki Miura

Background. It has been shown that the transcription factors activator protein (AP)-1 and nuclear factor (NF)-&kgr;B play a pivotal role in various renal diseases. We aimed to study their activations in chronic cyclosporine A (CsA) nephrotoxicity and evaluate the effect of magnesium (Mg) supplementation and blockade of the renin-angiotensin system (RAS), which are known to ameliorate CsA nephrotoxicity, on these transcription factors. Methods. CsA (15 mg/kg/day) was administered subcutaneously daily to rats maintained on a low-sodium diet for 7, 14, and 28 days. DNA-binding activities of AP-1 and NF-&kgr;B in renal cortex were determined by electrophoretic mobility shift assay. Results. DNA-binding activity of AP-1 and NF-&kgr;B started to increase at day 14 and further elevated at day 28 by CsA treatment. These activations were markedly attenuated when rats were maintained on a high-Mg diet. In contrast, angiotensin-converting enzyme inhibitor (ACEI) had no effect on CsA-induced AP-1 activation. CsA-induced activation of NF-&kgr;B was suppressed by ACEI at day 14, whereas such effect could not be observed at day 28. Conclusions. Renal cortical AP-1 and NF-&kgr;B DNA binding were activated in chronic CsA nephrotoxicity. These activations were induced largely by means of RAS-independent mechanisms. It is suggested that prevention of CsA-induced DNA-binding activation of these transcription factors is at least in part responsible for the beneficial effects of Mg supplementation on CsA nephrotoxicity.


BMC Urology | 2011

Hyperbaric oxygen therapy for painful bladder syndrome/interstitial cystitis resistant to conventional treatments: long-term results of a case series in Japan

Tomoaki Tanaka; Yujiro Nitta; Kazuya Morimoto; Noriaki Nishikawa; Chikako Nishihara; Satoshi Tamada; Hidenori Kawashima; Tatsuya Nakatani

BackgroundThere is no confirmed strategy for treating painful bladder syndrome/interstitial cystitis (PBS/IC) with unclear etiology. Therefore, a pilot study was carried out to evaluate the efficacy and safety of hyperbaric oxygen (HBO) therapy in treatment-resistant PBS/IC patients.MethodsHBO treatment (2.0 ATA for 60 minutes/day × 5 days/week for 2 or 4 weeks) was performed on 11 patients with severe symptoms that had not been improved by previous therapy regimens between December 2004 and July 2009.ResultsSeven of the 11 patients demonstrated persistent improvement in symptoms during the 12 months after HBO treatment. These responders demonstrated a decrease in the pelvic pain scale and urgency scale from 7.7 ± 1.0 and, 6.6 ± 0.9 to 3.4 ± 2.5 and 4.3 ± 2.4 after 12 months, respectively (p < 0.05). The total score of the interstitial cystitis symptom index and 24-hour urinary frequency demonstrated a significant sustained decrease from the baseline. Two responders, who received an additional course of HBO 12 and 13 months after initial treatment, respectively, did not suffer impairment for more than two years. There was one case of transient eustachian tube dysfunction and three cases of reversible exudative otitis media as a consequence of HBO treatment.ConclusionsHBO is a potent treatment for PBS/IC patients resistant to conventional therapy. It was well tolerated and provided maintained amelioration of pain, urgency and urinary frequency for at least 12 months.


Cancer Science | 2012

DDX39 acts as a suppressor of invasion for bladder cancer

Minoru Kato; Min Wei; Shotaro Yamano; Anna Kakehashi; Satoshi Tamada; Tatsuya Nakatani; Hideki Wanibuchi

The object of the present study was to identify markers for predicting urinary bladder cancer progression by comparative proteome analysis of bladder cancers and paired normal mucosas. We found that DDX39 was overexpressed in four of six bladder cancers examined compared with respective control tissues. Immunohistochemical analysis using 303 bladder cancer specimens revealed that DDX39 was inversely correlated to pT stage and histological grade progression. The incidence of DDX39high tumors (positive cells ≥50%) was 68.6%, 43.5%, 20.0%, and 5.3% in pTa, pT1, pTis, and ≥pT2 tumors, respectively, and 65.2%, 60.7%, and 19.6% in G1, G2, and G3 tumors, respectively. The incidence of DDX39high tumors was significantly lower in pT1 and ≥pT2 compared to pTa tumors, and also significantly lower in G3 compared to G1 and G2 tumors. Follow‐up analysis (n = 105) revealed that DDX39low tumors (positive cells <50%) were associated with disease progression (hazard ratio 7.485; P = 0.0083). Furthermore, DDX39‐knockdown bladder cancer cells increased their invasion ability compared to negative control cells. These results suggest that DDX39 is a suppressor of invasion and loss of its function predicts disease progression in bladder cancers. (Cancer Sci 2012; 103: 1363–1369)


Urology | 2008

Cobalt Protoporphyrin Attenuates Rat Obstructive Nephropathy: Role of Cellular Infiltration

Tomoaki Iwai; Kouichirou Kitamoto; Kae Teramoto; Yuichi Machida; Satoshi Tamada; Tokihito Yukimura; Hiroshi Iwao; Tatsuya Nakatani; Katsuyuki Miura

OBJECTIVES Renal interstitial inflammation is closely related to the progressive renal fibrosis. It has been reported that heme oxygenase-1 (HO-1) induction attenuated renal fibrosis in obstructive nephropathy. To elucidate the antifibrogenic mechanisms of HO-1, we examined the effect of HO-1 induction on renal interstitial inflammation. METHODS Adult male rats underwent unilateral ureteral obstruction (UUO). The rats were pretreated with cobalt protoporphyrin (CoPP, a potent HO-1 inducer; 15 or 50 mg/kg) subcutaneously on the day -6 and -1 before UUO. Sham-operated rats served as controls. Renal interstitial fibrosis, macrophage and T cell infiltration were immunohistochemically assessed on the day 5 after UUO. Gene expressions of HO-1 and profibrogenic molecules were determined by real-time reverse transcriptase-polymerase chain reaction. RESULTS CoPP dose-dependently induced HO-1 activity, protein, and messenger RNA (mRNA) expression in the renal cortices. CoPP significantly attenuated the renal fibrosis in a dose-dependent manner. Gene expressions of transforming growth factor-beta and extracellular matrix proteins were upregulated in UUO and were attenuated by CoPP. CoPP markedly inhibited T cell infiltration. Unexpectedly, it enhanced macrophage influx dose dependently. Double immunostaining of macrophage and HO-1 showed that CoPP elicited HO-1 overexpression in infiltrating macrophages, whereas UUO alone did not. CONCLUSIONS HO-1 induction protected against the renal interstitial fibrosis in rat obstructive nephropathy. It is suggested that inhibition of T cell influx is, at least in part, involved in the protection. Increased macrophages that overexpress HO-1 may play an important role in attenuating renal fibrosis.


Cancer Science | 2016

Anti-PD-L1 treatment enhances antitumor effect of everolimus in a mouse model of renal cell carcinoma.

Yukiyoshi Hirayama; Min Gi; Shotaro Yamano; Hirokazu Tachibana; Takahiro Okuno; Satoshi Tamada; Tatsuya Nakatani; Hideki Wanibuchi

Immunotherapy based on blockade of the programmed death‐1 (PD‐1)/programmed death‐ligand 1 (PD‐L1) axis has shown promising clinical activity for renal cell carcinoma (RCC) patients; however, the most effective use of these agents in combination with conventional targeted therapy remains to be resolved. Here we evaluated the therapeutic efficacy of the combination of the mTOR inhibitor everolimus (EVE) and anti‐PD‐L1 using an immunocompetent mouse model of RCC. We first assessed the in vitro effect of EVE on PD‐L1 expression in the human 786‐O and mouse RENCA RCC cell lines and found that EVE upregulated PD‐L1 expression in these RCC cell lines. We then treated RENCA tumor‐bearing mice with EVE and found that PD‐L1 expression was also increased in tumor cells after EVE treatment. To determine the antitumor effects of EVE alone, anti‐PD‐L1 alone, and EVE in combination with anti‐PD‐L1, we evaluated their antitumor effects on RENCA tumor‐bearing mice. A significant decrease in the tumor burden was observed in the EVE alone but not in the anti‐PD‐L1 alone treatment group compared with the control group. Importantly, the combination of EVE with anti‐PD‐L1 significantly reduced tumor burden compared with the EVE alone treatment, increasing tumor infiltrating lymphocytes (TILs) and the ratio of cytotoxic CD8+ T cells to TILs. The results of the present study demonstrated that anti‐PD‐L1 treatment enhanced the antitumor effect of EVE in a mouse model, supporting a direct translation of this combination strategy to the clinic for the treatment of RCC.


PLOS ONE | 2015

Association of MnSOD AA Genotype with the Progression of Prostate Cancer.

Taro Iguchi; Ching Y. Wang; Nicolas Barry Delongchamps; Minoru Kato; Satoshi Tamada; Takeshi Yamasaki; Gustavo de la Roza; Tatsuya Nakatani; Gabriel P. Haas

Purpose To investigate whether manganese superoxide dismutase (MnSOD) genetic polymorphism is associated with the clinical significance of prostate cancer. Materials and Methods Prostates were obtained from 194 deceased men 45 years or older who did not have a history of prostate cancer. Serial sections and histological examinations of the prostate were performed. The MnSOD genotypes of the specimens were determined by polymerase chain reaction restriction fragment length polymorphism analysis. Results Of the 194 men, 31 and 26 had clinically insignificant and significant prostate cancer. Clinically significant cancer comprised 29% and 58% of the cancers in men <70 and >70 years old, respectively. The age-specific proportion of significant cancer significantly increased with the advance of age (p<0.001). MnSOD AA, as compared with the other genotypes (VA and VV together), was associated with significant prostate cancer across all ages, odds ratio (OR) 2.34, 95% confidence interval (CI) 0.99-5.49, and in men older than 69 years (OR 4.89, 95% CI 1.51-15.8), but not in men younger than 70 years. The genotype was not associated with clinically insignificant cancer regardless of age. The comparison between significant and insignificant cancer, the OR (95% CI) for MnSOD AA was 5.04 (1.05-24.2) (sensitivity 0.57, specificity 0.78, positive predictive value 0.78) in men older than 69 years. Conclusions MnSOD polymorphism is strongly associated with the clinical significance of prostate cancer in men older than 69 years, but not in men younger than 70 years suggesting that oxidative stress may be involved in the progression of the disease. MnSOD may be a clinically useful marker to predict the potential of progression of prostate cancer.


International Journal of Urology | 2015

Efficacy of naftopidil for nocturia in male patients with lower urinary tract symptoms: comparison of morning and evening dosing.

Tomoaki Tanaka; Katsuyuki Kuratsukuri; Rikio Yoshimura; Takahisa Adachi; Tetsuo Yamaguchi; Tetsuji Ohmachi; Shinji Yamamoto; Takahiro J. Nakamura; Satoshi Tamada; Tatsuya Nakatani

To examine the difference in improvement of lower urinary tract symptoms between morning and evening dosing of α1‐blocker naftopidil.


Urology case reports | 2015

A Case of Metastatic Urachal Carcinoma Treated With FOLFIRI (irinotecan and 5-Fluorouracil/leucovorin) Plus Bevacizumab

Tomohiro Kanamaru; Taro Iguchi; Nao Yukimatsu; Yasuomi Shimizu; Yuki Kohyama; Hirokazu Tachibana; Minoru Kato; Takeshi Yamasaki; Satoshi Tamada; Tatsuya Nakatani

A 68-year-old man was introduced to our hospital for the treatment of lung and mediastinum lymph node metastases that originated from an urachal carcinoma 4 years after a partial cystectomy. First-line chemotherapy with an S-1 and cisplatin combination was ineffective. The patient received FOLFIRI plus bevacizumab chemotherapy as salvage chemotherapy. Stability was achieved after eight cycles of FOLFIRI plus bevacizumab therapy. We conducted a biopsy of the metastatic tumor, and the pathology of the biopsy tissue was partially necrotic. To our knowledge, this case represents the first report of a metastatic urachal carcinoma treated with FOLFIRI plus bevacizumab.

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Katsuyuki Miura

Shiga University of Medical Science

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