Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where J. Kumazawa is active.

Publication


Featured researches published by J. Kumazawa.


European Urology | 1994

Laparoscopic adrenalectomy: comparison with open adrenalectomy.

Seiji Naito; Jiro Uozumi; Hitoshi Ichimiya; Masao Tanaka; Kimoto K; Koichi Takahashi; Ohta J; J. Kumazawa

The results of the first 6 cases of laparoscopic adrenalectomy were compared with the most recent 11 consecutive cases of traditional open adrenalectomy for the treatment of benign adrenal tumor. In both groups, all the tumors were less than 4 cm in diameter and were removed successfully with no significant complications. The weight of the resected specimen and estimated blood loss were not significantly different in the two groups, and none of the patients needed a blood transfusion. Although laparoscopic adrenalectomy required a significantly longer operation time (median 230 min vs. 165 min for an open operation), the postoperative recovery estimated by the duration of restricted oral intake or walking was shorter, and the incidence of patients requiring postoperative parenteral analgesics was also significantly lower in laparoscopic adrenalectomy. Although the number of patients treated with the laparoscopic procedure is still small, these results suggest that laparoscopic adrenalectomy is a minimally invasive alternative to open adrenalectomy and, with further improvement of the operative technique and equipment, may become a more reliable and standard procedure for the treatment of benign adrenal tumor.


Dermatology | 1997

Prevention of Catheter-Associated Urinary Tract Infection by Meatal Disinfection

Tetsuro Matsumoto; Misao Sakumoto; Koichi Takahashi; J. Kumazawa

The incidence of catheter-associated urinary tract infections (UTIs) becomes higher with prolongation of the indwelling period of a catheter. As to the entry of bacteria, ascending UTIs have now attracted attention. In the present study. the metal area was examined bacteriologically and the possibility to use antiseptics for blocking the route of developing infections was investigated. The subjects included 72 patients with an indwelling, urethral catheter inserted post-operatively. These patients were divided into three groups treated with once or twice daily application of povidone-iodine or once daily application of povidone-iodine cream. In these groups, the relation between changes in isolation of bacteria from the meatal area and the incidence of UTI was evaluated. It was found that reduction in bacterial count by antisepsis is effective to prevent ascending UTIs. Moreover, once daily application of povidone-iodine was proven to be effective in male patients. The effective antisepsis in females was twice daily application of povidone-iodine.


European Urology | 1992

Bellini duct carcinoma of the kidney.

Koikawa Y; Naotaka Sakamoto; Seiji Naito; Masao Tanaka; Toyofumi Ueda; J. Kumazawa

Human epithelial cells of the kidney present a wide spectrum of cytological and histological variation. The normal epithelium of the kidneys also includes a number of morphologically and functionally different cell types which are arranged along the nephrons and collecting ducts. Although renal carcinoma can involve any type of renal cell, the most common is renal cell carcinoma of the proximal tubuli. Here, we present the case of a 65-year-old Japanese patient with a renal cell carcinoma arising from Bellini duct epithelial cells. State-of-the-art techniques were used to establish the diagnosis and histogenesis of this renal cell carcinoma.


International Urology and Nephrology | 1994

Clinical study of asymptomatic microscopic haematuria

Tetsuo Yasumasu; Yasuhiro Koikawa; Jiro Uozumi; Toyofumi Ueda; J. Kumazawa

A clinical statistical survey was performed on 355 patients with asymptomatic microscopic haematuria. Urologic lesions were detected in 19.4% of the patients. Urologic lesions requiring surgical treament were found in only two patients with bladder carcinoma and with renal calculus. With the exception of glomerulonephritis, the proportion of those over 40 years who had urologic lesions was higher. It is suggested that an initial evaluation based on excretory urography, cystoscopy and ultrasonography is more important for patients over 40 years.


European Urology | 1988

Endotoxemia in patients who underwent ultrasonic lithotripsy and extracorporeal shock wave lithotripsy.

Masao Tanaka; Tetsuro Matsumoto; Kitada S; J. Kumazawa; Hara S; Akito Yamaguchi

The authors conducted limulus tests of assay blood endotoxin in order to study the fever which often develops after ultrasonic lithotripsy (USL) and extracorporeal shock wave lithotripsy (ESWL). Assays of endotoxin were also conducted after transurethral resection (TUR) and other operations as a basis for comparison. Endotoxemia was observed in 18 among 28 patients (64.3%) who underwent USL, in 8 among 34 patients (23.5%) who underwent ESWL, in 1 among 14 patients (7.1%) who underwent TUR and in 1 among 11 patients (9.1%) who underwent other operations. The incidence of endotoxemia was significantly higher (p less than 0.01 by chi 2 test) in patients who had undergone USL than in those who had undergone ESWL, TUR or other operations.


Cancer Chemotherapy and Pharmacology | 1995

Treatment of advanced hormone-refractory prostate carcinoma with a combination of etoposide, pirarubicin and cisplatin

Seiji Naito; Toyofumi Ueda; Shuji Kotoh; J. Kumazawa; K. Itoh; Kazuyuki Sagiyama; Tetsuo Omoto; S. Andoh; Y. Hasegawa; Y. Fujisawa

A total of 20 patients with hormone-refractory prostate carcinoma entered a pilot study of combination chemotherapy based on the EAP (etoposide, Adriamycin and cisplatin) regimen, in which Adriamycin was replaced by pirarubicin, a less cardiotoxic derivative of Adriamycin. The response was assessed by criteria modified from those of the National Prostatic Cancer Project: prostate-specific antigen was employed instead of acid phosphatase. Of 18 evaluable patients, 6 achieved a partial response, 5 had stable disease, and in 7 the disease had progressed during therapy; thus, the overall response rate was 33.3% [95% confidence interval (CI) 11.5–55.1%]. Significant pain alleviation and performance status improvement were obtained in 5 of 12 patients (41.7%; CI 13.8–69.6%) and 3 of 13 patients (23.1%; CI 0.2–46.0%), respectively. Although myelosuppression was moderate to severe, no chemotherapy-related deaths or bacteriologically documented sepsis occurred; nor was there any clinical cardiotoxicity. All the responding patients received maintenance chemotherapy with etoposide thereafter. At present, the median duration of response is 33 weeks (range: 23–91 weeks) and the median survival period for all patients is 42 weeks (range: 27+ −136 weeks), with 12 deaths. In spite of the small number of patients treated, these results suggest that this chemotherapy regimen is active in advanced hormone-refractory prostate carcinoma.


Cancer Chemotherapy and Pharmacology | 1995

Phase II study of a new combined primary chemotherapy regimen, intravenous methotrexate and vincristine and intraarterial Adriamycin and cisplatin, for locally advanced urinary bladder cancer: preliminary results

Toshiro Kuroiwa; Seiji Naito; Kanehiro Hasuo; Takashi Kishikawa; Kouji Masuda; J. Kumazawa

A phase II study of a new combination therapy was performed using intraarterial (i.a.) cisplatin and Adriamycin in combination with i.v. methotrexate and vincristine for 27 patients with invasive urinary bladder carcinoma of stages T2-3NOMO, and the therapeutic effects were assessed. Methotrexate (20 mg/ m2) was given i.v. on days 1,15, and 22, and vincristine (0.7 mg/m2) was injected i.v. on day 2 before i.a. infusion therapy and on days 15 and 22. The i.a. chemotherapy was performed after both superior gluteal arteries had been embolized using 3- or 5-mm stainless-steel coils. A mixture of cisplatin (50–70 mg/m2) and Adriamycin (20 mg/m2) was infused i.a. via both internal iliac arteries over a period of 20–30 min. Angiotensin II (mean dose, 21 μg) was simultaneously infused i.a. in 15 of 27 patients. In 24 of the 27 patients, at least 2 cycles of full-dose chemotherapy were completed. The dose was decreased in the remaining 3 patients because of their poor health status and advanced age. Among the 27 patients, 9 and 14 had complete (CR) and partial responses (PR), respectively; 3 manifested no change (NC), and 1 had progressive disease (PD). The objective response rate (CR + PR) was 85.2%. Among the 27 patients staged T2-3 NOMO, 6 (CR, 1; PR, 5) underwent total cystectomies and 18 (CR, 8; PR, 8; NC, 2) had transurethral resection of a bladder tumor (TUR-Bt) or partial resections following chemotherapy. The remaining 3 diminished-dose patients had no surgery. Of the 27 patients, 22 were alive after a median follow-up period of 21 + (range, 7–48 +) months. No significant side effect was observed except for lower extremity paresthesias in 5 patients (18.5%). These results point to the effectiveness of this therapy and to the possibility of urinary bladder preservation in patients with invasive, advanced urinary bladder cancers.


International Urology and Nephrology | 1992

Calcium blockers enhance cisplatin-induced nephrotoxicity in rats

Jiro Uozumi; Toyofumi Ueda; Tetsuo Yasumasu; Yasuhiro Koikawa; J. Kumazawa

To examine the effects of calcium blockers on nephrotoxicity caused by cisplatin, the renal function and renal accumulation of Pt in Sprague-Dawley rats given 6.5 mg/kg i.v. cisplatin simultaneously with several doses of verapamil or nicardipine were evaluated. BUN, serum creatinine and kidney Pt concentrations in rats given more than 5.0 mg/kg of verapamil were significantly higher than those of the control animals injected with 6.5 mg/kg i.v. cisplatin alone, and the increase of each value was dependent upon the dose of verapamil. BUN, creatinine and kidney Pt in rats injected with more than 0.5 mg/kg i. p. nicardipine were also significantly higher than those of the controls. Calcium blockers enhanced the renal accumulation of Pt and the nephrotoxicity of cisplatin.


International Urology and Nephrology | 1992

Cytologic findings of fine needle aspirates in chronic prostatitis.

Takuya Matsumoto; T. Soejima; Masao Tanaka; Seiji Naito; J. Kumazawa

Cytologic studies in patients with prostatic infection, primarily those with chronic prostatitis, were conducted on samples obtained by the fine needle aspiration method. Infiltration of inflammatory cells such as polymorphonuclear leukocytes and macrophages was observed to a greater extent in patients with chronic bacterial prostatitis as compared to those with chronic nonbacterial prostatitis or prostatodynia. The pathogen was isolated in only one out of 28 patients with chronic bacterial prostatitis. We concluded that fine needle biopsy is useful for assessing patients with prostatic inflammation, but not for detecting microorganisms because of focal colonization of the organisms in the glands.


Urologia Internationalis | 1991

Endopyelotomy for Treatment of Ureteropelvic Junction Obstruction

Seiji Naito; Akito Yamaguchi; Masao Tanaka; Koichi Kimiya; Tetsuro Matsumoto; J. Kumazawa; S. Hara

A total of 14 patients underwent endopyelotomy at our institution for treating ureteropelvic junction (UPJ) obstruction (12 primary and 2 secondary obstructions) between March 1986 and July 1989. Radiographic evaluation of the patients with a minimum follow-up of 6 months demonstrated improvement in 11, while the remaining 3 were stable. These 3 were cases with primary obstruction and 2 of them had had an associated large redundant renal pelvis. No patients exhibited evidence of increased hydronephrosis or decreased renal function. Twelve of the 14 patients had had preoperative symptoms. Complete and partial remission of the symptoms was obtained in 11 and in 1 who was radiographically stable, respectively. Thus, our success rate for endopyelotomy was 75% in primary obstruction. Successful results were obtained in all the 2 cases with secondary obstruction. There was 1 patient with an intraoperative complication (extravasation) and a late complication related to the stent. However, the problems were minor and easily corrected. Our results suggest that careful selection of cases may lead to a high success rate in endopyelotomy for treating primary UPJ obstruction.

Collaboration


Dive into the J. Kumazawa's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge