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Dive into the research topics where Osamu Muraishi is active.

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Featured researches published by Osamu Muraishi.


The Journal of Urology | 2002

THE CORRELATION OF SERUM CARBOHYDRATE ANTIGEN 19-9 WITH BENIGN HYDRONEPHROSIS

Kazumi Suzuki; Osamu Muraishi; Akihiko Tokue

PURPOSE High serum carbohydrate antigen 19-9 in patients with hydronephrosis but without malignant disease is reportedly rare but to our knowledge the clinical features of hydronephrosis that affect this level have not yet been clarified. We examined the correlation of serum carbohydrate antigen 19-9 with hydronephrosis status in patients with benign hydronephrosis. MATERIALS AND METHODS We used 123 serum samples from 68 patients with and 55 without hydronephrosis. All patients enrolled in this study had no malignant disease. Serum carbohydrate antigen 19-9 was measured by immunoradiometric assay and that level was correlated with clinical factors. RESULTS Serum carbohydrate antigen 19-9 in patients with hydronephrosis was significantly higher than in those without hydronephrosis (p <0.0001). The serum level was elevated to greater than 37 units per ml. in 25% of the patients with but in only 1.8% of those without hydronephrosis. In the hydronephrosis group the clinical features that significantly correlated with the increased serum level were bilateral hydronephrosis, urinary tract infection, proteinuria, increased serum blood urea nitrogen, severe urinary tract occlusion and high grade hydronephrosis. CONCLUSIONS Serum carbohydrate antigen 19-9 was significantly elevated in patients with benign hydronephrosis. Hydronephrosis causes false-positive results when screening for malignant disease by serum carbohydrate antigen 19-9 measurement.


Urology | 2010

Anteroposterior Dissection HoLEP: A Modification to Prevent Transient Stress Urinary Incontinence

Fumiyasu Endo; Yoshiyuki Shiga; S. Minagawa; T. Iwabuchi; Akiko Fujisaki; Masahiro Yashi; Kazunori Hattori; Osamu Muraishi

OBJECTIVES The prevalence of transient stress urinary incontinence (SUI) after HoLEP has been reported to be as high as 44%. Anteroposterior dissection HoLEP was newly developed to protect the urethral sphincter and therefore lower the incidence rate of SUI. This study was conducted to determine the SUI incidence rate after anteroposterior dissection HoLEP. METHODS Sixty-eight consecutive patients with benign prostatic hyperplasia underwent HoLEP from January to December 2008. The first 31 cases (Surgery 1) underwent HoLEP according to Gillings method. The next 37 cases (Surgery 2) underwent anteroposterior dissection HoLEP, where adenoma was dissected antegradely. This antegrade movement of the cystoscope allows the apical gland to be removed from the sphincter without causing damage. Surgical quality indexes (hemoglobin change, operating time, resected prostate volume) between the 2 groups were compared. All patients were assessed at 2 weeks postoperatively for clinical SUI, international prostate symptom score (IPSS), quality of life (QoL), and peak flow rates (Q(max)). RESULTS Patient characteristics and surgical quality indexes did not differ between the 2 groups. Clinical SUI was found in 25.2% of cases in the Surgery 1 group, but only 2.7% in the Surgery 2 group. IPSS, QoL and Q(max.) were significantly improved postoperatively in both groups. At 2 weeks, the QoL of the Surgery 2 group was significantly improved compared with that observed for Surgery 1 (1.5 ± 1.1 vs 2.4 ± 1.0, P = .02). The Q(max.) of Surgery 2 was significantly higher compared with Surgery 1 (19.8 ± 8.4 vs 13.0 ± 4.7 ml/s, P = .02). CONCLUSIONS These results indicate that our anteroposterior dissection HoLEP is a promising procedure to avoid postoperative SUI and also to substantially improve QoL.


Urology | 2010

Relationship Between Prostate-specific Antigen and Hematocrit: Does Hemodilution Lead to Lower PSA Concentrations in Men With a Higher Body Mass Index?

Kazuhiro Ohwaki; Fumiyasu Endo; Osamu Muraishi; Sonoe Hiramatsu; Eiji Yano

OBJECTIVES To examine whether a lower hematocrit was associated with a lower prostate-specific antigen (PSA), when stratifying by body mass index (BMI) in healthy men. PSA test is widely used in screening for prostate cancer. Many studies have found that PSA levels inversely correlate with BMI. It remains unclear whether hemodilution causes this inverse relationship. METHODS We investigated 19,367 men who visited a hospital for a routine health checkup in 2007. We obtained information on age, BMI, PSA, hematocrit, and smoking status. BMI was categorized as < 18.5, 18.5-22.0, 22.0-25.0, 25.0-30.0, and > or = 30.0 kg/m(2). RESULTS In all subjects, older age and lower BMI were weakly correlated with a higher PSA (r = 0.20, P <.001 and r = -0.05, P <.001, respectively). A multiple regression model for predicting PSA was constructed using age, current smoking status, and hematocrit for each BMI category. After controlling for age and smoking, PSA increased significantly with increasing hematocrit in participants with BMIs of 18.5-30 kg/m(2) (all P <.001). For example, in men with a BMI of 22-25 kg/m(2), slight increases (1.4% increase; 95% confidence interval, 1.0%-1.9%) were observed in PSA with a 1-unit increase in hematocrit. CONCLUSIONS In healthy men with a BMI of 18.5-30 kg/m(2), a lower hematocrit was significantly associated with a lower PSA. Hemodilution may explain the lower PSA levels observed in men with a higher BMI, resulting in an inverse relationship between BMI and PSA.


The Journal of Urology | 1999

DISTRIBUTION OF DOXORUBICIN IN THE BLADDER WALL AND REGIONAL LYMPH NODES AFTER BLADDER SUBMUCOSAL INJECTION OF LIPOSOMAL DOXORUBICIN IN THE DOG

Hideo Kiyokawa; Yasuhiko Igawa; Osamu Muraishi; Yoshihiko Katsuyama; Keiji Iizuka; Osamu Nishizawa

PURPOSE Liposome-encapsulated doxorubicin (Lip-Dox) has increased therapeutic efficacy and reduced toxicity compared to free doxorubicin (Dox). To assess the utility of Lip-Dox for local control of bladder cancer, we examined the distribution of Dox in the bladder wall and the regional lymph nodes of dogs after bladder submucosal injection of Lip-Dox. MATERIALS AND METHODS In 8 dogs (group SM), Lip-Dox (2 mg.:1 ml.) was injected into the submucosal layer of each lateral bladder wall by using a flexible cystoscope. The other 8 dogs (group IV) underwent intravenous injection of free Dox (4 mg.). Both groups of animals were sacrificed at 1, 3, 5 or 7 days after the injections. The concentration of Dox was measured in both the mucosal and muscle layers of 5 bladder wall sites and also in the external iliac lymph nodes bilaterally. RESULTS The Dox-concentration in the lymph nodes of group SM was significantly higher (about 15-100 times) than that of group IV throughout the whole follow-up period. The Dox-concentration in the bladder wall for group SM was significantly higher than that in group IV (about 70-930 times at the lateral walls and 2-830 times at the other sites). CONCLUSION The present results demonstrate that Lip-Dox injected into the bladder submucosally distributes well, both in the whole bladder wall and in regional lymph nodes and remains at a high concentration in these tissues for at least one week after injection.


The Journal of Urology | 1992

Gastrocystoplasty in dogs : an ulcerating effect of acid urine

Osamu Muraishi; Shinsuke Ikado; Toshio Yamashita; Kenji Yamaguchi; Akimi Ogawa

Six dogs underwent bladder augmentation using an isolated flap of the body of the stomach after a supratrigonal cystectomy. Each dog was followed for six months with periodic determinations of urine pH, blood chemistry, cystometry and cystography. Postoperatively, urine pH decreased markedly after a meal in most dogs. No persistent hypergastrinemia was found. Autopsy showed that histological erosions developed in the bladder remnant in five dogs, and an ulcer in the bladder remnant in one dog. These results indicate that when an isolated, vagally denervated gastric segment is incorporated into the bladder, acid secretion from the segment may ulcerate the bladder.


The Journal of Urology | 2001

IMPROVEMENT OF URETEROILEAL ANASTOMOSIS IN ORTHOTOPIC ILEAL NEOBLADDER WITH MODIFIED LE DUC PROCEDURE: SHORT SUBMUCOSAL TUNNEL TECHNIQUE

Osamu Muraishi; Toshio Yamashita; Shinya Ishikawa; Yosuke Hara; Akihiko Tokue

PURPOSE A modified Le Duc procedure with a short submucosal tunnel was applied for ureteroileal implantation in ileal orthotopic neobladder and bladder augmentation with the ileum. We assessed the rate of stenosis and ureteral reflux at the ureteroileal anastomosis after this procedure. MATERIALS AND METHODS Two women and 22 men underwent radical cystectomy and creation of a Hautmann ileal neobladder for invasive bladder cancer. Another woman underwent ileal bladder augmentation with bilateral ureteral reimplantation into the ileal segment. Ureteroileal anastomosis was performed using the modified Le Duc technique in 48 renoureteral units. Followup in all patients included retrograde cystography done before discharge home and excretory urography, renal ultrasonography or abdominal computerized tomography every 4 to 6 months. Followup was 11 to 39 months in 23 of the 25 cases. RESULTS Retrograde cystography before discharge home revealed no urinary reflux in any reimplanted ureter. There was no ureteral stenosis or reflux in 20 male and 3 female patients (44 renoureteral units) who voided successfully without catheterization. A unilateral ureteral stricture at the ureteroileal anastomotic site in 1 man who voided successfully was treated with endoscopic surgery. Bilateral slight upper urinary tract dilatation caused by ureteral reflux was present in another man who did not void successfully. CONCLUSIONS The modified Le Duc technique is simple and safe for forming an ureteroileal anastomosis in ileal orthotopic neobladder creation. It appears to have a low ureteral stenosis and reflux complication rate in patients who successfully void postoperatively.


Urologia Internationalis | 2001

Segmental multicystic dysplastic kidney in an adult woman.

Kazumi Suzuki; Shinsuke Kurokawa; Osamu Muraishi; Akihiko Tokue

We report a case of unilateral segmental multicystic dysplastic kidney (SMCDK) in an adult woman. A 42-year-old woman presented with abdominal distension and gross hematuria. The preoperative diagnosis was cystic renal cell carcinoma, and a radical nephrectomy was performed. Histopathologically, the resected kidney was SMCDK with severe hydronephrosis.


Urologia Internationalis | 2000

Leiomyoma of the Ureter

Masahiro Yashi; Shinichi Hashimoto; Osamu Muraishi; Kazuhiko Tozuka; Akihiko Tokue

We report a case of leiomyoma of the ureter, and the patient underwent partial ureteral resection. This is the 8th case reported after 1955, and the clinical features of ureteral leiomyomas of these 8 cases are discussed.


The Journal of Urology | 1996

Total Replacement of Urethral Mucosa with Oral Mucosa in Dogs

Keiji Iizuka; Osamu Muraishi; Toshitaka Maejima; Yoshihiro Kitami; Yue-Min Xu; Kenji Watanabe; Akimi Ogawa

PURPOSE If the urethral mucosa is replaced by another mucosa, urethral recurrence might decrease in patients who undergo neobladder construction for bladder cancer. We determined whether such replacement is possible. MATERIALS AND METHODS Six dogs underwent an operation consisting of a longitudinal urethral incision at its full length and immediate closure. In 6 other dogs, after the urethral mucosa was totally removed, a tubularized sublingual mucosa was closely set inside the urethral lumen. Postoperatively, the urinary stream and external meatus were observed every day. To measure urine leakage, a 10-minute pad test was performed once a month. All dogs were sacrificed 3 to 12 weeks after the operation for histological examination of the urethra. The excised urethras were examined with a 12F catheter for urethral patency. RESULTS All dogs were continent postoperatively. The results of the 10-minute pad test showed no significant difference in the weight increase of the pad among the control, sham-operated and mucosa-replaced dogs. Urethral stricture developed in 1 mucosa-replaced dog. Histological examination revealed that all of the grafted oral mucosa survived in the urethra. CONCLUSION These results indicate that the urethral mucosa can be replaced by oral mucosa without damaging the continence mechanism in female dogs.


The Journal of Urology | 2001

A TECHNIQUE FOR RESECTION OF SMALL BLADDER TUMORS USING A FLEXIBLE CYSTOSCOPE ON AN OUTPATIENT BASIS: BLADDER TUMOR RESECTION WITH NEWLY DESIGNED HOT CUP FORCEPS

Osamu Muraishi; Sumitaka Mitsu; Kazumi Suzuki; Takeshi Koshimizu; Akihiko Tokue

PURPOSE We describe a technique for resecting small papillary superficial bladder tumors using a new device and flexible cystoscope. MATERIALS AND METHODS In a 79-year-old man 3 small recurrent papillary bladder tumors were resected transurethrally on an outpatient basis. The procedure was performed using a flexible cystoscope and a newly designed type of cup forceps with the patient under topical anesthesia. No urethral catheter remained indwelling after surgery and the patient was discharged home the same day. RESULTS Bladder tumor resection using this technique was tolerable to the patient and postoperative bladder hemorrhage was not noted. Resected specimens were adequate for pathological tumor evaluation, which revealed grade 1 stage Ta superficial transitional cell carcinoma of the bladder. CONCLUSIONS This easy technique seems to be tolerated well by the patient. Resected specimens should be adequate for evaluating the pathological grade and depth of stage Ta or T1 superficial bladder cancer. This technique may be an alternative to standard transurethral resection for removing small recurrent bladder lesions in select patients who prefer outpatient management of bladder tumors.

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Masahiro Yashi

Dokkyo Medical University

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Kazumi Suzuki

Jichi Medical University

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