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Featured researches published by Sakamoto W.


European Urology | 1990

Effects of high energy shock wave exposure on renal function during extracorporeal shock wave lithotripsy for kidney stones

Taketoshi Kishimoto; Senju M; Toshikado Sugimoto; Keisuke Yamamoto; Sakamoto W; Iimori M; Kanasawa T; Seiji Wada; Masanobu Maekawa

In order to study the effects of high energy shock wave exposure on the kidney in extracorporeal shock wave lithotripsy (ESWL) using Dornier HM3, renal hemodynamics and renal function before and after ESWL were analyzed by 99mTc-DTPA renoscintigraphy. Various urinary enzyme activities (LDH, GOT, GPT, NAG, gamma-GTP) and low molecular protein concentrations (alpha 1-microglobulin, beta 2-microglobulin) before and after ESWL were also compared. In the early phase of the renoscinitgram obtained in the 1st min after injection of 99mTc-DTPA, the time required to reach maximum radioactivity was significantly prolonged after ESWL in both the affected and contralateral kidney. This indicated that renal blood flow decreased in both the affected and contralateral kidney immediately after ESWL. An analysis of the 30-min renoscintigram showed that urinary clearance was delayed in the affected kidney in spite of no overt obstruction due to stone fragments. As for urinary enzyme activities and low molecular protein concentrations, they were standardized by urinary creatinine concentration measured at the same time. Urinary LDH, GOT, GPT and NAG activities remarkably increased on the day of ESWL followed by a decrease close to pretreatment levels on the 4th day, though these levels were still significantly higher than pretreatment levels. Urinary gamma-GPT activity was significantly higher than the pretreatment level only on the day of ESWL. Urinary alpha 1-microglobulin and beta 2-microglobulin concentrations significantly increased on the day of ESWL and were still high on the 4th day.(ABSTRACT TRUNCATED AT 250 WORDS)


Nephron | 1991

Examination of Aggravating Factors of Urinary Excretion of N-Acetyl-Beta-D-Glucosaminidase after Extracorporeal Shock Wave Lithotripsy

Sakamoto W; Taketoshi Kishimoto; T. Nakatani; Yasushi Ameno; Akira Ohyama; Masato Kamizuru; Yasumoto R; Masanobu Maekawa

We measured urinary N-acetyl-beta-D-glucosaminidase (NAG) excretion before and after extracorporeal shock wave lithotripsy (ESWL) with a view to study the underlying factors which aggravate renal impairment immediately after ESWL. The factors associated with the significant elevation of urinary NAG after ESWL included female sex, a previous history of ESWL, and urinary tract infection (UTI). By studying the backgrounds of these factors, we found that both the female group and the group with a previous history of ESWL contained significantly more patients with UTI. These findings indicate that UTI may be one of the risk factors which aggravate renal damage immediately after ESWL, and that careful management is necessary in the ESWL treatment of urinary tract stones with UTI.


International Journal of Urology | 2003

Extraperitoneal laparoscopic Lich–Gregoir antireflux plasty for primary vesicoureteral reflux

Sakamoto W; Tatsuya Nakatani; Tamio Sakakura; Yoshinori Takegaki; Keiichi Ishi; Sadanori Kamikawa; Toshikado Sugimoto

Abstract We performed laparoscopic Lich–Gregoir antireflux plasty on 4 patients with primary vesicoureteral reflux. All procedures were conducted using the extraperitoneal approach. The average surgical time was 230 min. There were no complications. After surgery, voiding cysturethrograms showed no reflux in all patients.


European Urology | 1991

Stone fragility-measurement of stone mineral content by dual photon absorptiometry

Sakamoto W; Taketoshi Kishimoto; Yosinori Takegaki; Toshikado Sugimoto; Seiji Wada; Keisuke Yamamoto; Masanobu Maekawa; Hironori Ochi

We measured the mineral content of urinary tract stones by dual photon absorptiometry, which is widely used for the analysis of bone mineral content, and compared the values of the stones by dual photon absorptiometry (DPA values) with the results of an in vitro fracture study as well as those of an in vivo extracorporeal shock wave lithotripsy treatment study. The results of a preliminary experiment showed that the DPA values of 20 urinary tract stones reflected actual stone mineral content. As a result of the in vitro fracture study, the DPA value calculated by volume of a struvite stone, which was the most easily disintegrated, was the lowest (0.53 g/cm3). The DPA values of calcium oxalate monohydrate and apatite stones, which poorly disintegrated, were the highest (0.98, 1.01 g/cm3). The DPA value of calcium oxalate dihydrate, which moderately disintegrated, was 0.86 g/cm3. By the in vivo extracorporeal shock wave lithotripsy treatment study, the total DPA values of stones measured before extracorporeal shock wave lithotripsy treatment in 12 patients were 0.73 +/- 0.34 g in successful cases and 1.92 +/- 0.43 g in unsuccessful cases with a significant difference between the two (p less than 0.05). These results showed that the measurement of stone mineral content by dual photon absorptiometry was useful in predicting the fragility of stones against shock waves before performing extracorporeal shock wave lithotripsy treatment for patients with urinary tract stones.


Urologia Internationalis | 1988

Granulocytic sarcoma of testis preceding acute myelocytic leukemia.

Hidenori Kawashima; Sakamoto W; Nishijima T; Masato Hanada; Katsushi Mori; Masanobu Maekawa

A unique case of granulocytic sarcoma of the testis as a first manifestation of acute myelocytic leukemia preceding hematologic pathology is reported. The testicular specimen was identified by immunoperoxidase staining to be composed of immature granulocytes. Acute myelocytic leukemia of which the first manifestation is a primary testicular tumor is extremely rare, and the related literature is reviewed.


Nephron | 1989

Cardiac Output, Renal Blood Flow and Hepatic Blood Flow in Rats with Glycerol-Induced Acute Renal Failure

Taketoshi Kishimoto; Sakamoto W; T. Nakatani; T. Ito; K. Iwai; Taku Kim; Y. Abe

Cardiac output (CO), renal blood flow (RBF) and hepatic blood flow (HBF) were measured by the microsphere method before (control) and at 4 and 10 h after the induction of acute renal failure by intramuscular injection of glycerol in water-drinking, long-term saline-drinking and long-term captopril (converting enzyme inhibitor)-drinking rats. At 4 h after glycerol injection, CO, RBF and HBF significantly decreased in all three groups. At 10 h after glycerol injection, CO, RBF and HBF recovered to 88% of the respective control levels in only the saline-drinking rats, whereas CO, RBF and HBF further decreased to 53, 38 and 58% of the control levels, respectively in the captopril-drinking rats. At this time, not only acute renal failure but also hepatic disorder developed in the water-drinking and captopril-drinking rats as indicated by elevations of serum creatinine, urea nitrogen, alanine aminotransferase and other blood chemistry levels. The development of acute renal failure was not suppressed by captopril, but by long-term saline load. Thus, we conclude that the decrease in CO is an important variable of the early decrease in renal and hepatic perfusion in glycerol-induced acute renal failure, and that the early recovery of HBF as well as RBF may play an important role in preventing the development of acute renal failure.


International Journal of Urology | 2011

Combination of a liquid fibrin sealant with sheet-type hemostatic agents: Experimental evaluation in partial nephrectomy animal model

Keiichi Ishii; Hidenori Kawashima; Takuma Hayama; Tosihiro Asai; Sadanori Kamikawa; Sakamoto W; Sumika Miyabashira; Shiro Oka; Toshikado Sugimoto

Liquid fibrin sealants, together with sheet‐type hemostatic agents, have been used during partial nephrectomies to secure effective hemostasis at the suture site. Using animal kidneys, we investigated which hemostatic agent might adhere most effectively to the renal tissue and serve best as a bolster. Liquid fibrin sealant alone, or in combination with a sheet‐type hemostat, such as collagen, gelatin or oxidized‐cellulose hemostat, was applied to the cut surface of the kidney of anesthetized rabbits, and the differences in the degree of adherence to the kidney and resultant hemostatic efficacy were evaluated. Histological analyses were also carried out to compare the degree of adherence of each of the aforementioned hemostats to the kidney tissue. Fibrin sealant plus the collagen or gelatin hemostat was found to have a stronger hemostatic effect than fibrin sealant applied alone or fibrin sealant plus oxidized‐cellulose hemostat. The histological investigation showed that the fibrin sealant adhered well to kidney tissue when it was applied with the collagen or gelatin hemostat, showing the advantage of combining these two materials for achieving effective hemostasis. Fibrin sealant used in combination with the collagen or gelatin hemostat was the most suitable for obtaining a reinforced hemostatic effect at the suture site in a partial nephrectomy animal model.


International Journal of Urology | 1998

ROLE OF THE TRANSITION ZONE FOR ELEVATING SERUM PROSTATE-SPECIFIC ANTIGEN IN BENIGN PROSTATIC HYPERPLASIA

Sakamoto W; Hironori Iwata; Sadanori Kamikawa; Kiyoshi Tsurusaki; Toshikado Sugimoto; Tatsuya Nakatani; Kazunobu Sugimura; Keisuke Yamamoto; Taketoshi Kishimoto

Background:


Nephron | 1992

Effect of ciclosporin on cardiac output and regional blood flow in rats : ciclosporin-induced nephropathy and its prevention with calcium channel blocker

Taketoshi Kishimoto; Takashi Tsujino; T. Nakatani; Taku Kim; Akira Ohyama; Sakamoto W; Rikio Yoshimura; T. Maekawa; Masanobu Maekawa

The effect of ciclosporin (CS) on cardiac output (CO) and regional blood flow was studied using the microsphere method in heminephrectomized rats with and without renal arterial clamping prior to the administration of CS. The effect of a calcium (Ca) channel blocker, verapamil, was also examined on CS-induced nephropathy. CS at a dose of 40 mg/kg per day was given orally using a gastric tube for 7 days. Verapamil was given in the drinking water for 7 days. Significant increases in blood urea nitrogen (BUN) and serum creatinine (sCr) with a significant decrease in renal inulin clearance (CIn) were noted after 7 days of CS administration in both intact and ischemic-kidney groups, indicating the development of CS-induced nephropathy. The ischemic-kidney group showed a significantly severe nephropathy as compared with the intact-kidney group. As for change in CO and regional blood flow, CS caused a significant decrease in CO, renal blood flow (RBF) and brain blood flow, while hepatic arterial blood flow and muscular blood flow significantly increased. The renal outer cortical blood flow decreased markedly while the inner cortical blood flow remained unchanged. Although verapamil slightly but significantly decreased mean arterial blood pressure in CS-treated rats, CO and its distribution did not change. BUN and sCr were not significantly ameliorated in the intact-kidney group. However, in the ischemic-kidney group, verapamil caused a significant improvement in RBF, ameliorating CS-induced elevation of BUN and sCr, and a decrease in CIn.(ABSTRACT TRUNCATED AT 250 WORDS)


Urologia Internationalis | 1991

Combined Therapy of Interleukin 2 with Cyclophosphamide or Bacillus Calmette-Guérin against Implanted Bladder Cancer Cells in Mice

Seiji Wada; Shinichi Ikemoto; Takahisa Terada; Hiroshi Tanaka; Masato Kamizuru; Sakamoto W; Taketoshi Kishimoto; Masanobu Maekawa

1 x 10(5) cells of FAMFT-induced bladder cancer cell line (MBT-2) were injected into the right leg of the C3H/He mice. 10 days later, these animals with the same tumor size were divided into four groups. Group 1 is the control with no treatment. Group 2 underwent interleukin 2 (IL-2) treatment for 10 days since the 11th day after tumor inoculation. Group 3 received just one CPM injection on the 10th day. Group 4 had a combination therapy of CPM, followed by IL-2. Group 1 and 2 exhibited enlargement of tumor size, resulting in the death of all animals. Administration of CPM led to temporary disappearance of tumor, followed by local tumor recurrence in all cases. However, combined therapy with IL-2 showed complete remission of the tumors. Natural killer cell activity measured by the 51Cr release assay of the spleen cells using Yac-1 cells as target cells 20 days after tumor inoculation was found to be significantly higher in group 2 and 4, while lymphokine-activated killer cell activity of the spleen cells against P-815 cells showed no significant difference between the four groups.

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Asakawa M

Osaka City University

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Nishio S

Osaka City University

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