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Dive into the research topics where Kazuyasu Nakao is active.

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Featured researches published by Kazuyasu Nakao.


Breast Cancer Research and Treatment | 2005

Lymph vessel density correlates with nodal status, VEGF-C expression, and prognosis in breast cancer.

Yasushi Nakamura; Hironao Yasuoka; Masahiko Tsujimoto; Shigeru Imabun; Masaaki Nakahara; Kazuyasu Nakao; Misa Nakamura; Ichiro Mori; Kennichi Kakudo

Metastasis to the regional lymph nodes through the lymphatic vessels is a common step in the progression of cancer and an important prognostic factor in many types of cancer. Recent evidence suggests that VEGF-C promotes lymphangiogenesis, and that tumor lymphangiogenesis in turn promotes lymphatic metastasis. We have studied the role of LVD in breast cancer, and examined whether LVD is associated with lymph node metastasis, VEGF-C expression, or prognosis. In addition, we examined whether VEGF-C mRNA transcript levels were associated with lymph node metastasis and LVD. We began by investigating the lymphatics in primary human breast carcinoma with long-term follow-up (113 cases of invasive ductal and other breast cancers) by quantitative immunohistochemical staining for podoplanin. We then analyzed the relationship between LVD and lymph node status as well as VEGF-C immunoreactivity and other established clinicopathological parameters. The relationship between LVD and prognosis was also studied. VEGF-C mRNA transcript levels were examined by quantitative real-time RT-PCR, in 55 invasive ductal breast carcinomas. This was followed by an analysis of the relationship between VEGF-C mRNA transcript levels and lymph node metastasis as well as LVD. Mean LVD of ‘hot spots’ was 10.2 ± 7.4/each case. LVD was significantly correlated with lymph node metastasis (p < 0.0001), VEGF-C immunoreactivity (p = 0.0084), and podoplanin positive lymphatic invasion (p < 0.0001). Survival curves determined by the Kaplan–Meier method and univariate analysis demonstrated that high LVD was associated with both worse disease free survival (p = 0.0033) and overall survival (p = 0.0391). VEGF-C mRNA transcript levels were also correlated with lymph node metastasis (p = 0.0074) and LVD (p = 0.0409). Increased LVD was correlated with lymph node metastasis and VEGF-C expression. High LVD may be a significant unfavorable prognostic factor for long-term survival in breast cancer.


Transplantation | 1985

Correlation between cellular ATP level and bile excretion in the rat liver

Wataru Kamiike; Masaaki Nakahara; Kazuyasu Nakao; Masato Koseki; Toshirou Nishida; Yasunaru Kawashima; Fusao Watanabe; Kunio Tagawa

The influence of the cellular level of adenosine triphosphate (ATP) in the liver on bile excretion was studied in rats. In ischemia, the cellular ATP level decreased rapidly--and, concomitantly, bile flow stopped within 5 min. Administration of L-ethionine i.p. to rats reduced the bile flow rate with decrease in the cellular ATP level. The correlation between the bile flow rate and the cellular ATP level was confirmed in a liver perfusion system. On anoxic perfusion, the ATP level and bile flow rate changed in the same manner as in ischemia. The recovery rates of both on reoxygenation decreased with increase in the anoxic perfusion period. During perfusion under oxygenated conditions, decrease in cellular ATP to various levels by infusion of various concentrations of potassium cyanide, an inhibitor of respiration, resulted in corresponding and concomitant suppression of bile excretion. Kinetic analysis of the bile flow rate revealed a Michaelis-Menten-type curve for the cellular ATP level. The apparent Kms for ATP of bile flow rate in L-ethionine-treated rat liver and liver perfused with potassium cyanide were 1.0 and 1.6 mM, and their Vmax values were 4.1 and 2.5 microliter/min/g liver, respectively. The concentrations of main bile components, such as phospholipids, cholesterol, and taurocholate increased, but their total outputs decreased with decrease in the ATP level, and returned to the normal range with recovery of the ATP level. Thus, it was shown experimentally that the extent of hepatic injury can be assessed simply by monitoring the bile flow rate, which reflects the cellular level of ATP.


Clinical Cancer Research | 2006

Nitric oxide in breast cancer: induction of vascular endothelial growth factor-C and correlation with metastasis and poor prognosis.

Yasushi Nakamura; Hironao Yasuoka; Masahiko Tsujimoto; Katsuhide Yoshidome; Masaaki Nakahara; Kazuyasu Nakao; Misa Nakamura; Kennichi Kakudo

PURPOSE: Metastasis to regional lymph nodes through the lymphatic vessels is a common step in the progression of cancer. Recent evidence suggests that tumor production of vascular endothelial growth factor-C (VEGF-C) promotes lymphagiogenesis, which in turn promotes lymphatic metastasis. Nitric oxide (NO) may also increase metastatic ability in human cancers. EXPERIMENTAL DESIGN: Nitrite/nitrate levels and VEGF-C production were assessed in MDA-MB-231 breast cancer cells after induction and/or inhibition of NO synthesis. Formation of nitrotyrosine, a biomarker for peroxynitrate formation from NO in vivo, was analyzed in primary human breast carcinoma with long-term follow-up. The relationship between nitrotyrosine levels and lymph node status, VEGF-C immunoreactivity, and other established clinicopathologic variables, as well as prognosis, was analyzed. RESULTS: Production of nitrite/nitrate and VEGF-C in MDA-MB-231 cells was increased by treatment with the NO donor DETA NONOate. The NO synthase inhibitor N(G)-nitro-l-arginine methyl ester eliminated this increase. High-grade nitrotyrosine staining was observed in 57.5% (65 of 113) of the invasive breast carcinomas. Nitrotyrosine levels were significantly correlated with VEGF-C immunoreactivity and lymph node metastasis. Survival curves determined by the Kaplan-Meier method showed that high nitrotyrosine levels were associated with reduced disease-free and overall survival. In multivariate analysis, high nitrotyrosine levels emerged as a significant independent predictor for overall survival. CONCLUSIONS: Our data showed a role for NO in stimulating VEGF-C expression in vitro. Formation of its biomarker nitrotyrosine was also correlated with VEGF-C expression and lymph node metastasis. Furthermore, high nitrotyrosine levels may serve as a significant prognostic factor for long-term survival in breast cancer.


Modern Pathology | 2002

Heparanase: a key enzyme in invasion and metastasis of gastric carcinoma.

Weihua Tang; Yasushi Nakamura; Masahiko Tsujimoto; Misako Sato; Xiaojuan Wang; Kazushi Kurozumi; Masaaki Nakahara; Kazuyasu Nakao; Misa Nakamura; Ichiro Mori; Kennichi Kakudo

Previous reports have shown that the biochemical activity of heparanase is significantly correlated with the invasion and metastasis of malignant cells in vitro. Recently, it was found that the human heparanase gene was cloned and highly expressed in malignant cell lines and human solid malignant tumors. In the present study, we investigated the heparanase mRNA expression by using in situ hybridization in 116 paraffin-embedded tissues of primary gastric carcinomas. To explore its clinicopathologic significance, it was detected in the various steps of tumor progression and then compared with prognostic indicators. As a result, the heparanase expression was more prevalent in late-stage rather than early-stage carcinomas (P < .0001) and was more frequent in tumors of large size (P = .0212). Expression also correlated with lymphatic (P = .0086) and venous (P = .0171) invasion and with negative prognostic factors such as lymph nodal (P < .0001) and distant (P = .0221) metastases. However, in a multivariate analysis, messenger RNA expression of heparanase was not an independent prognostic factor. It was concluded that heparanase might play an important role in the development of invasion and metastasis of the gastric cancer. It was indicated that patients with heparanase-positive gastric carcinoma would have a greater chance of metastasis with a poor prognosis.


The Journal of Thoracic and Cardiovascular Surgery | 1997

Differentiated thyroid carcinoma with airway invasion: Indication for tracheal resection based on the extent of cancer invasion☆☆☆★

Toshirou Nishida; Kazuyasu Nakao; Masayasu Hamaji

OBJECTIVE Although aggressive approaches to locally invasive differentiated thyroid carcinoma are reported to improve the prognosis, few investigations have provided an indication for airway resection. The present study was undertaken to determine the best indication for airway resection for differentiated thyroid carcinoma invading the trachea. METHODS One hundred seventeen patients with differentiated thyroid carcinoma invading surrounding structures were retrospectively studied for local failures and prognosis and were divided into five groups mainly on the basis of macroscopic findings: Group 1 consisted of 40 patients who underwent tracheal resection for deep tracheal invasion; group 2 consisted of 14 patients with deep tracheal invasion and no airway resection; group 3 consisted of 13 patients with superficial tracheal invasion and no airway resection; group 4 comprised 48 patients with extrathyroidal invasion other than laryngotracheal structures; and group 5 consisted of two patients who underwent tracheal resection for superficial invasion. RESULTS Resectional management of the airway for patients with deep tracheal invasion decreased local recurrence and improved postoperative prognosis compared with nonresectional management for the tumor, or shaving off tumor from the trachea for patients with superficial invasion, did not increase postoperative local failures or mortality (group 3 vs groups 4, 5, and 1). CONCLUSION These results implied that differentiated thyroid carcinomas with superficially limited invasion could be treated successfully by nonresectional management of the trachea and that those with deep invasion should be treated by resection of the invaded trachea.


Modern Pathology | 2003

Clinicopathological Significance of Vascular Endothelial Growth Factor-C in Breast Carcinoma with Long-Term Follow-Up

Yasushi Nakamura; Hironao Yasuoka; Masahiko Tsujimoto; Qifeng Yang; Ayumi Tsukiyama; Shigeru Imabun; Masaaki Nakahara; Kazuyasu Nakao; Misa Nakamura; Ichiro Mori; Kennichi Kakudo

Expression of angiogenic and lymphangiogenic factors by tumors may influence the route of metastatic spread. The angiogenic factor vascular growth factor-C (VEGF-C) is implicated in the development of lymphatic vessels and promotion of lymphatic metastasis. The purpose of this study was to determine whether VEGF-C correlates with lymph node metastasis or prognosis. We assessed VEGF-C expression using immunohistochemistry in 123 invasive breast carcinomas with long-term follow-up. The relationship between VEGF-C expression and lymph node status and other established clinicopathological parameters was assessed. Whether VEGF-C expression plays a prognostic role in breast cancer was also investigated. VEGF-C expression was identified in 103 cases (83.7%). Positive VEGF-C was significantly correlated with lymph node metastasis (P = 0.0131). Survival curves determined by the Kaplan-Meier method and univariate analysis demonstrated that positive VEGF-C was associated with both disease-free survival (P = 0.0165) and overall survival (P = 0.0175). On the basis of our findings, VEGF-C plays a crucial role in lymph node metastasis and may be a significant prognostic factor for long-term survival in breast cancer.


Annals of Surgery | 1997

Preservation of recurrent laryngeal nerve invaded by differentiated thyroid cancer.

Toshirou Nishida; Kazuyasu Nakao; Masayasu Hamaji; Wataru Kamiike; Kazushi Kurozumi; Hikaru Matsuda

OBJECTIVE This study was undertaken to determine whether the recurrent laryngeal nerve involved in differentiated thyroid carcinoma could be preserved. SUMMARY BACKGROUND DATA Few investigations have provided definitive results concerning preservation of the recurrent laryngeal nerve involved in thyroid cancer. Complete excision with resection of the recurrent laryngeal nerve reportedly did not improve survival over incomplete excision in differentiated thyroid carcinoma. METHODS A retrospective study was performed with the medical records of 50 patients with differentiated carcinoma and preoperative normal vocal cord function to investigate outcomes of recurrent laryngeal nerve preservation including local recurrence, prognosis, and postoperative vocal cord function. The recurrent laryngeal nerves on 1 or both sides were preserved in 23 patients (the preserved group), whereas the involved recurrent laryngeal nerve of the other 27 patients was resected (the resected group). RESULTS Backgrounds of patients were similar between the resected and preserved groups. The number of patients with recurrences in each group was similar, and incidence of local, regional, and distant metastatic recurrences were not different between the groups. Postoperative overall survival of the preserved group was similar to that of the resected group (p = 0.1208). More than 60% of patients or of nerve at risk in the preserved group restored normal vocal cord function within 6 months. Some functional vocal cord movement was recognized in 80% of patients or of nerve at risk. All patients in the resected group including patients with nerve anastomosis showed permanent paralysis of the ipsilateral vocal cord. CONCLUSIONS These results suggested that the recurrent laryngeal nerve, even if infiltrated by differentiated thyroid cancer, is worthwhile to preserve for maintenance of postoperative vocal cord function without affecting the incidence of local recurrence or prognosis.


British Journal of Cancer | 2000

The status of Fas and Fas ligand expression can predict recurrence of hepatocellular carcinoma

Yasuhiro Ito; Morito Monden; Tsutomu Takeda; Hidetoshi Eguchi; Umeshita K; Hiroaki Nagano; Shoji Nakamori; Keizo Dono; Masato Sakon; M Nakamura; Masahiko Tsujimoto; Masaaki Nakahara; Kazuyasu Nakao; Yasuyuki Yokosaki; Nariaki Matsuura

The status of Fas and Fas ligand (Fas L) expression was investigated in this study for 103 hepatocellular carcinomas (HCC). We studied the expression of the following three factors, Fas and Fas L expression in carcinoma cells and Fas L expression in stromal mononuclear cells (defined as stromal Fas L index). Fas expression in HCC cells was significantly decreased in cases with poor differentiation (P< 0.0001) and of larger size (P = 0.0058). Fas L expression in carcinoma cells was observed exclusively in moderately or poorly differentiated cases. Furthermore, each factor had prognostic significance for disease-free survival (DFS) (P< 0.0001, P = 0.0222 and 0.0027 respectively). We then scored the results of each factor and defined the total score as ‘Fas-Fas L risk score’. The P -value of the score for DFS was even lower than that of the clinical stage by multivariate analysis. These results suggest that the evaluation of Fas and Fas ligand expression potentially has a significant prognostic value for DFS of HCC patients, in addition to the clinical stage, and can be regarded as a new prognostic marker.


Cancer | 1985

Clinicopathologic study of thyroid carcinoma infiltrating the trachea

Takao Tsumori; Kazuyasu Nakao; Masahiko Miyata; Masaaki Izukura; Monden Y; Masami Sakurai; Yasunaru Kawashima; Kazuya Nakahara

Eighteen patients (10 women and 8 men), ranging in age from 37 to 80 years, with thyroid carcinoma infiltrating the trachea comprised this series. Eleven had primary and 7 had recurrent cases. Total laryngectomy was performed in 4 patients, and tracheal resection was carried out followed by end‐to‐end anastomosis in 13 patients. In one patient, reconstruction was done with Navilles artificial trachea after tracheal resection. Eleven patients were alive after 1 year and 8 months to 6 years and 7 months after the operation. This result was significantly better than that of a group of ten patients without resection of the infiltrated trachea (seven patients died within 6 months). Thus, combined resection of the upper airway improved the prognosis of advanced thyroid carcinoma with tracheal infiltration. Histologic examination of surgical specimens demonstrated well‐differentiated carcinoma in seven patients, poorly differentiated carcinoma in seven patients, undifferentiated carcinoma in three patients, and squamous cell carcinoma in one patient. The result showed a higher frequency of poorly differentiated carcinoma than in the control group of 70 patients without tracheal infiltration.


British Journal of Cancer | 1999

Both cell proliferation and apoptosis significantly predict shortened disease-free survival in hepatocellular carcinoma

Yasuhiro Ito; Nariaki Matsuura; Masato Sakon; Tsutomu Takeda; Umeshita K; Hiroaki Nagano; Shoji Nakamori; Keizo Dono; Masahiko Tsujimoto; Masaaki Nakahara; Kazuyasu Nakao; Morito Monden

In this study, we investigated the proliferating cell index by the percentage of Ki-67 expressing cells (Ki-67 LI) and the apoptotic index (AI) by the number of morphologically apoptotic cells per 1000 carcinoma cells in haematoxylin and eosin sections of 76 hepatocellular carcinomas (HCC). Both indices showed excellent correlation with each other (P < 0.0001) and were significantly higher in cases of poor differentiation, of advanced stages, with portal invasion and with intrahepatic metastasis. Furthermore, cases with higher Ki-67 LI or higher AI displayed poor outcomes for disease-free survival (P = 0.0001 and P = 0.0005) by univariate analysis. By multivariate analysis, both indices could be regarded as independent prognostic factors. These results strongly suggest that Ki-67 LI and AI have very similar clinical significance, reflecting the existence of biologically aggressive phenotypes and poor disease-free survival rate in HCC.

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Masaaki Nakahara

Wakayama Medical University

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