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Dive into the research topics where Takahisa Nakamoto is active.

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Featured researches published by Takahisa Nakamoto.


International Journal of Urology | 2001

The prevalence of renal cell carcinoma: A nation‐wide survey in Japan in 1997

Ken Marumo; Yoshiaki Satomi; Noriomi Miyao; Michihiko Hasegawa; Yoshihiko Tomita; Tatsuo Igarashi; Tetsuro Onishi; Hayakazu Nakazawa; Momokuni Fukuda; Seiichiro Ozono; Toshiro Terachi; Tomoyasu Tsushima; Takahisa Nakamoto; Kawamura J

Abstract Background: The present study was conducted to investigate the incidence of renal cell carcinoma by sex, age group and different regions in Japan.


The Journal of Urology | 2002

THREE-DIMENSIONAL NAVIGATOR FOR RETROPERITONEAL LAPAROSCOPIC NEPHRECTOMY USING MULTIDETECTOR ROW COMPUTERIZED TOMOGRAPHY

Kazushi Marukawa; Jun Horiguchi; Masanobu Shigeta; Takahisa Nakamoto; Tsuguru Usui; Katsuhide Ito

PURPOSE We evaluated the efficacy of a 3-dimensional (D) navigator for retroperitoneal laparoscopic nephrectomy. MATERIALS AND METHODS A total of 21 patients with malignant localized renal (16) or ureteral (5) neoplasms underwent multi-detector row computerized tomography. The 3-D navigator was created using volume rendering technique. These findings were compared with videos obtained during laparoscopy. RESULTS The 3-D navigator depicted all renal arteries (100% sensitivity) and 24 of the 25 renal veins (96% sensitivity). Hilar anatomy, including the tumor, major vessels and adrenal gland, and their relationships were visualized as in laparoscopic views. CONCLUSIONS The 3-D navigator has a potentially important role in retroperitoneal laparoscopic nephrectomy. It is able to guide surgeons and aid in avoiding operative risks and possible complications.


The Journal of Urology | 2002

LOCALIZATION AND EXPRESSION OF TISSUE INHIBITOR OF METALLOPROTEINASE-1 IN HUMAN UROTHELIAL CANCER

Akira Yano; Takahisa Nakamoto; Kunihiro Hashimoto; Tsuguru Usui

PURPOSE We evaluated the role of tissue inhibitor of metalloproteinase-1 (TIMP-1) in the invasion and metastasis of human urothelial cancer. MATERIALS AND METHODS The expression level of TIMP-1 messenger (m)RNA was determined in 33 urothelial carcinomas, including upper urothelial cancer in 15 cases and bladder cancer in 18, by Northern blot analysis. Localization of TIMP-1 mRNA was analyzed by in situ hybridization. These data were compared with clinicopathological features. We also determined the growth activity of tumor cells using immunohistochemical staining for Ki-67 and compared it with the expression levels of TIMP-1 mRNA. These data were also compared with clinicopathological features. RESULTS The expression level of TIMP-1 mRNA significantly correlated with pathological stage and histological differentiation. In situ hybridization showed that TIMP-1 mRNA was expressed in the cytoplasm of urothelial cancer cells. The Ki-67 labeling index significantly correlated with the expression level of TIMP-1 mRNA in urothelial cancer. Patients with high expression of TIMP-1 mRNA had a poorer prognosis than those with low expression. CONCLUSIONS TIMP-1 mRNA is expressed in the cytoplasm of cancer cells and high expression indicates more malignant potential in cases of urothelial cancer.


Biochemical and Biophysical Research Communications | 1988

Analysis of growth factors in renal cell carcinoma.

Takahisa Nakamoto; Akihiro Usui; Kenji Oshima; Hideaki Ikemoto; Shinji Mitani; Tsuguru Usui

Tissue extracts prepared from human renal tissue, renal cell carcinoma and serum-free conditioned media of ACHN cells and A498 cells, cell line originated from human renal cell carcinoma, stimulated DNA synthesis of BALB/c 3T3 cells. The activity (growth factor activity) was significantly higher in renal cell carcinoma than in normal tissues. Radioreceptor assay revealed that the contents of epidermal growth factor and type alpha transforming growth factor in the tissue extracts from renal cell carcinoma and conditioned media from renal cell carcinoma cell lines were below detectable level. Most of growth factor activity of the tissue extracts and conditioned media showed high affinity for heparin-Ultrogel, indicating that the major growth factor activity was due to heparin-binding growth factor(s). In addition, renal cell carcinoma contained growth factor activity for ACHN cells, which did not show specific affinity for heparin-Ultrogel.


International Journal of Urology | 1997

Inhalation of lnterleukin-2 Combined with Subcutaneous Administration of Interferon for the Treatment of Pulmonary Metastases from Renal Cell Carcinoma

Takahisa Nakamoto; Yoshinobu Kasaoka; Shinji Mitani; Tsuguru Usui

Background: lnterleukin‐2 is the most promising antitumor agent for advanced renal cell carcinoma, but systemic immunotherapy with interleukin‐2 might be limited because of inadequate efficacy and severe adverse effects. In this study, we treated 7 patients with lung metastases from renal cell carcinoma with topical application of interleukin‐2 by inhalation.


The Journal of Urology | 1994

Metastatic Renal Cell Carcinoma Arising in a Native Kidney of a Renal Transplant Recipient

Takahisa Nakamoto; Mikio Igawa; Shinji Mitani; Mitsutaka Ueda; Akihiro Usui; Tsuguru Usui

We report a case of metastatic renal cell carcinoma arising in the native kidney of a renal transplant recipient. A 39-year-old man, who had undergone living renal transplantation from his mother at age 32, presented with complaints of paraplegia of the leg caused by a pathological fracture of the 3rd lumbar vertebra. The bone tumor was extirpated and pathological examination revealed metastatic adenocarcinoma. Abdominal computerized tomography showed a tumor in the right native kidney. Right nephrectomy and resection of the right 7th rib tumor were performed. Pathological evaluation demonstrated renal cell carcinoma of the right native kidney (pT2bpN0pV0M1, mixed cell type, grade 2). Postoperatively, cyclosporine was discontinued and natural interferon-alpha was given. The remaining bone metastasis had completely resolved with no significant sign of rejection 1 year after surgery.


The Journal of Urology | 2000

ENDOSCOPIC SUBURETERAL GLUTARALDEHYDE CROSS-LINKED COLLAGEN INJECTION FOR THE TREATMENT OF SECONDARY VESICOURETERAL REFLUX: COMPARISON WITH PRIMARY VESICOURETERAL REFLUX IN ADULTS

Katsumi Inoue; Takahisa Nakamoto; Akihiro Usui; Tsuguru Usui

PURPOSE We assessed the effectiveness of endoscopic subureteral glutaraldehyde cross-linked collagen injection for treating vesicoureteral reflux in patients with vesicoureteral disorders. MATERIALS AND METHODS All 51 ureters studied had grade II or greater vesicoureteral reflux. We treated 18 patients (24 refluxing ureters) with secondary and 17 adults (27 refluxing ureters) with primary vesicoureteral reflux. The primary group served as controls to establish normal urination. A total of 14 patients with secondary vesicoureteral reflux had a low compliant autonomous bladder, including 11 with myelodysplasia and 3 after pelvic surgery and radiotherapy. One patient had an unstable bladder due to cerebral palsy and 3 had anatomical abnormalities of the urinary tract. We evaluated the estimated reflux-free rate in the secondary and adult primary vesicoureteral reflux groups. RESULTS Repeat injection was required in 24 ureters because of recurrent reflux. Average injected volume in the secondary and primary groups was 2.72 and 2.88 ml. per refluxing unit, respectively. The estimated reflux-free rate after the initial injection decreased gradually to about 35% in each group, while 12 and 24 months after the last injection it remained constant at 70% in the secondary group but decreased from 84.7% to 62.1% in the primary group. The percent of late recurrence was higher in the primary group. CONCLUSIONS Long-term efficacy of the endoscopic correction of vesicoureteral reflux in the secondary group was similar to that in the primary group. Thus, endoscopic subureteral glutaraldehyde cross-linked collagen injection is useful for treating complicated secondary vesicoureteral reflux as a minimally invasive procedure. It is considered optional treatment of primary vesicoureteral reflux to avoid long-term prophylactic treatment.


Surgery Today | 2011

Retroperitoneoscopic treatment of ureteral invagination caused by a long fibroepithelial polyp protruding into the bladder: report of a case.

Yasuhisa Hasegawa; Koji Mita; Tetsuhiro Ueki; Yoshiki Ishida; Shuntaro Koda; Yasuyuki Seno; Takahisa Nakamoto; Akio Matsubara

We describe how we performed retroperitoneoscopic surgery for a 15.5-cm fibroepithelial polyp, which originated in the lowest portion of the right upper ureter, protruded intermittently into the bladder, and caused ureteral invagination. To our knowledge, this is the first report of the retroperitoneoscopic management of ureteral invagination caused by a long fibroepithelial polyp.


International Journal of Urology | 1997

HORSESHOE KIDNEY WITH RETROCAVAL URETER AND URETEROPELVIC JUNCTION OBSTRUCTION : A CASE REPORT

Masanobu Shigeta; Takahisa Nakamoto; Mitsuru Nakahara; Nobuhiko Hiromoto; Tsuguru Usui

We report a rare disorder, horseshoe kidney accompanied by retrocaval ureter and ureteropelvic junction obstruction, in a 42‐year‐old man. This is the third case in the world literature.


The Journal of Urology | 2001

EVALUATION OF ANTIBODY CLASS IN RESPONSE TO ENDOSCOPIC SUBURETERAL COLLAGEN INJECTION IN PATIENTS WITH VESICOURETERAL REFLUX

Katsumi Inoue; Takahisa Nakamoto; Akihiro Usui; Tsuguru Usui

PURPOSE Clinical problems after glutaraldehyde cross-linked collagen injection for vesicoureteral reflux are the appearance of anticollagen antibodies and a decrease in collagen with time. We evaluated whether antibody production affects reflux recurrence and implanted collagen absorption. MATERIALS AND METHODS We treated 27 patients (39 ureters) who had vesicoureteral reflux with endoscopic subureteral glutaraldehyde cross-linked collagen injection. The maximum diameter of the elevated ureteral orifice was measured 3-dimensionally and the numerical value calculated by multiplying each diameter by approximately pi/6 was used as the ultrasound estimate of injected collagen volume. The 1-to-6-month collagen volume ratio was used as an index of the decrease in implant collagen volume. The antibody class against bovine collagen was characterized by indirect enzyme-linked immunosorbent assay. RESULTS Seroconversion in 6 patients was noted a mean 6.8 months after the first injection. In these patients the antibody class was IgG dominant and IgA or IgM was not detected. There was no significant difference in the total injected collagen volume, total number of injections or collagen volume ratio in the seropositive and seronegative groups. Reflux recurred in 4 patients and the curve of the reflux-free rate was similar regardless of antibody appearance. CONCLUSIONS The immune response to bovine collagen injection for vesicoureteral reflux does not depend on injected collagen volume or an increased number of treatments. Antibody production had no effects on absorption of the implanted collagen or reflux recurrence.

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