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Dive into the research topics where Akihiko Iwasawa is active.

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Featured researches published by Akihiko Iwasawa.


Obstetrics & Gynecology | 1997

Human papillomavirus in squamous cell carcinoma of the vulva by polymerase chain reaction

Akihiko Iwasawa; Pekka Nieminen; Matti Lehtinen; Jorma Paavonen

Objective To investigate the prevalence of human papillomavirus (HPV) DNA in squamous cell carcinoma of the vulva by polymerase chain reaction (PCR). Methods Archival diagnostic phase biopsies from 74 patients with squamous cell carcinoma of the vulva were investigated for HPV DNA by PCR. We used both consensus primers located in the open reading frame L1 and type-specific primers for HPV 6 (open reading frame E5), HPV 11 (open reading frame L1), HPV 16, HPV 18, and HPV 33 (open reading frame E6). Results HPV DNA was detected in 27 (36%) of the 74 patients, of whom 19 had HPV 16, nine had HPV 18, one had HPV 33, and one had unclassified HPV DNA. No case of HPV type 6 or 11 was detected. Two squamous cell carcinomas were positive for both HPV 16 and 18, and one was positive for both HPV types 16 and 33. Three squamous cell carcinomas positive for E6 gene using type-specific primers were negative using L1 consensus primers. Conclusion Our PCR methods using both consensus open reading frame L1-derived primers and type-specific open reading frame E6-derived primers of HPV types 16, 18, and 33 seemed to be an appropriate combination for the detection of HPV DNA in archival tissues of vulvar carcinoma. Both HPV types 16 and 18 were associated with squamous cell carcinoma of the vulva, although the prevalence of HPV 16 was considerably lower than in cervical carcinoma. It appears that vulvar and cervical carcinomas are not identical etiologically and that factors other than HPV are important in vulvar carcinogenesis.


The Journal of Urology | 2015

A Randomized Controlled Study of the Efficacy of Tamsulosin Monotherapy and its Combination with Mirabegron for Overactive Bladder Induced by Benign Prostatic Obstruction

Koji Ichihara; Naoya Masumori; Fumimasa Fukuta; Taiji Tsukamoto; Akihiko Iwasawa; Yoshinori Tanaka

PURPOSE We evaluated the efficacy and safety of add-on treatment with a β3-adrenoceptor agonist (mirabegron) for overactive bladder symptoms remaining after α1-blocker (tamsulosin) treatment in men with benign prostatic obstruction. MATERIALS AND METHODS Patients with benign prostatic obstruction with urinary urgency at least once per week and a total OABSS of 3 or more points after 8 or more weeks of treatment with tamsulosin were enrolled in the study. They were randomly allocated to receive 0.2 mg tamsulosin daily or 0.2 mg tamsulosin and 50 mg mirabegron daily for 8 weeks. The primary end point was change in total OABSS. Safety assessments included change in post-void residual urine volume and adverse events. RESULTS From January 2012 through September 2013 a total of 94 patients were randomized. Of these patients 76 completed the protocol treatment. In the full analysis set the change in total OABSS during the treatment period was significantly greater in the combination group than in the monotherapy group (-2.21 vs -0.87, p=0.012). The changes in scores for urinary urgency, daytime frequency, International Prostate Symptom Score storage symptom subscore and quality of life index at 8 weeks were significantly greater in the combination group. The change in post-void residual urine volume was significantly greater in the combination group. Although 6 patients experienced adverse events in the combination group, urinary retention was observed in only 1 patient. CONCLUSIONS Combined tamsulosin and mirabegron treatment is effective and safe for patients with benign prostatic obstruction who have overactive bladder symptoms after tamsulosin monotherapy.


Sexually Transmitted Diseases | 2003

Detection of human Papillomavirus DNA on the external genitalia of healthy men and male patients with urethritis

Satoshi Takahashi; Toshiaki Shimizu; Kou Takeyama; Yasuharu Kunishima; Hiroshi Hotta; Mikio Koroku; Hitoshi Tanda; Saka T; Masahiro Nishimura; Akihiko Iwasawa; Ryoji Furuya; Takaoki Hirose; Intetsu Kobayashi; Yoshiaki Kumamoto; Taiji Tsukamoto

Background Only a few studies have been done involving detection of human papillomavirus (HPV) DNA on the external genitalia of men without genital warts, although many have been done for women. We conducted HPV DNA detection among healthy male volunteers and men with urethritis, both having no visible lesions on their external genitalia. Goal The goal of the study was to determine the detection rate of HPV DNA in volunteers and patients with urethritis and to determine risk factor(s) for positive DNA. Study Design This was a prospective clinical study. Results HPV DNA was found in 1.3% of 75 volunteers and in 18.5% of 130 patients with urethritis. DNA of a high-intermediate oncogenic risk was more predominant than the low-risk type. Among various risk factors, only a history of STD was a significant factor for the positive detection of HPV DNA in multiple regression analysis. Conclusion HPV DNA was found in patients with urethritis more frequently than in volunteers, probably because the former had higher sexual activity.


Urologia Internationalis | 2009

Ejaculatory Disorders Caused by Alpha-1 Blockers for Patients with Lower Urinary Tract Symptoms Suggestive of Benign Prostatic Hyperplasia: Comparison of Naftopidil and Tamsulosin in a Randomized Multicenter Study

Naoya Masumori; Taiji Tsukamoto; Akihiko Iwasawa; Ryoji Furuya; Tomoko Sonoda; Mitsuru Mori

Introduction: To investigate the incidence of ejaculatory disorders caused by naftopidil and tamsulosin in patients with lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH). Materials and Methods: Ninety-five patients with LUTS/BPH who had International Prostate Symptom Scores (IPSS) of 8 or more were randomly assigned to receive naftopidil (50 mg/day, n = 48) or tamsulosin (0.2 mg/day, n = 47). Before and 12 weeks after treatment, a questionnaire was used to evaluate ejaculation. Results: Among men who had sexual activity during the 12 weeks, the proportion who reported an abnormal feeling on ejaculation was higher in the tamsulosin group (16.7%) than in the naftopidil group (7.4%), although the difference was not significant (p = 0.402). The proportion of men who reported reduced ejaculatory volume after treatment was significantly higher in the tamsulosin group (96.0%) than in the naftopidil group (73.1%, p = 0.0496). On the other hand, the improvements in IPSS and the quality of life index were significantly higher in the tamsulosin group than in the naftopidil group. Conclusions: Tamsulosin may cause a higher incidence of ejaculatory disorders than naftopidil, although the efficacy of 0.2 mg tamsulosin may be better than that of 50 mg naftopidil.


Journal of Infection and Chemotherapy | 2008

Clinical efficacy of azithromycin for male nongonococcal urethritis

Satoshi Takahashi; Masanori Matsukawa; Yuichiro Kurimura; Koh Takeyama; Yasuharu Kunishima; Akihiko Iwasawa; Mikio Koroku; Hitoshi Tanda; Nobukazu Suzuki; Yoshio Takagi; Takaoki Hirose; Masahiro Nishimura; Taiji Tsukamoto

The aim of this study was to confirm the clinical efficacy of a single-dose azithromycin (AZM) regimen (1000 mg) for patients with nongonococcal urethritis in real-life practice. The study finally evaluated 55 patients, 42 who were symptomatic and 13 who were asymptomatic, after excluding 40 who visited clinics only once. Sixteen of the symptomatic patients were diagnosed as having nongonococcal chlamydial urethritis, 7 as having nongonococcal nonchlamydial urethritis, and 19 as having urethritis without any microbial detection. Chlamydia trachomatis was detected in 11 asymptomatic patients, Mycoplasma genitalium in 1, and Ureaplasma urealyticum in 1. Of the patients who were microbiologically evaluated before and after single-dose AZM, microbiological cure was achieved in 87% (20/23) of those with symptomatic nongonococcal urethritis and in 100% (13/13) of those with asymptomatic nongonococcal urethritis. The clinical cure rate was 86% for the 42 symptomatic patients with detectable and undetectable pathogens. There were adverse events in 5 (9%) patients but they were commonly mild and self-limited. In conclusion, the single-dose AZM regimen was well tolerated and eradicated the estimated and potential pathogens of nongonococcal urethritis.


Sexually Transmitted Diseases | 1997

Human papillomavirus DNA in urine specimens of men with condyloma acuminatum

Akihiko Iwasawa; Eija Hiltunen-Back; T. Reunala; Pekka Nieminen; Jorma Paavonen

Background and Objectives: Because warts are often found in the male urethra, human papillomavirus (HPV) may well be present in urine of patients with urethral condylomata. Goal: To detect HPV DNA in urine specimens of men with condylomata acuminata using polymerase chain reaction. Study Design: Forty‐seven urine specimens and 25 paraffin‐embedded tissues of condylomata acuminata were obtained from men. Of the 47 urine specimens, 29 were from patients with urethral condylomata, 3 from patients with penile condylomata only, and 15 from control subjects without condylomata. Both L1 consensus primers and type‐specific primers for HPV 6, 11, 16, 18, and 33 were used. Results: HPV DNA was detected in 22 of the 29 (76%) urine specimens from patients with urethral condylomata, in none of the 3 urine specimens from patients with penile condylomata, and in none of the 15 controls. Paraffin‐embedded tissues of all 25 condylomas were positive for HPV DNA. The HPV types detected in urine were identical to those detected in urethral condylomas. Conclusions: HPV DNA is present in urine of patients with urethral condylomata. Urine may be used for noninvasive screening of asymptomatic HPV infections of the male genital tract. Detection of HPV DNA in urine may be useful for monitoring the response to treatment of urethral condylomata.


Urologia Internationalis | 1992

Presence of Human Papillomavirus 6/11 DNA in Condyloma acuminatum of the Urinary Bladder

Akihiko Iwasawa; Yoshiaki Kumamoto; Hiroshi Maruta; Michio Fukushima; Taiji Tsukamoto; Kei Fujinaga; Yasunori Fujisawa; Naohiko Kodama

A Japanese woman with condyloma acuminatum of the urinary bladder is presented. The condyloma acuminatum lesion was resected endoscopically and human papillomavirus 6/11 DNA was detected. After treatment, there has been no recurrence of the disease.


Advances in Urology | 2011

The Efficacy and Safety of Propiverine Hydrochloride in Patients with Overactive Bladder Symptoms Who Poorly Responded to Previous Anticholinergic Agents

Naoya Masumori; Shintaro Miyamoto; Taiji Tsukamoto; Seiji Furuya; Akihiko Iwasawa; Takashi Sato; Naoki Itoh; Akihiko Shibuya; Toshiro Oda

Objectives. To prospectively examine the efficacy and safety of propiverine hydrochloride in patients with overactive bladder (OAB) symptoms who poorly responded to previous treatment with solifenacin, tolterodine or imidafenacin. Methods. Patients aged ≥20 with persisting OAB symptoms (≥6 in OAB symptom score (OABSS)) even after at least 4-week treatment using solifenacin, tolterodine or imidafenacin were enrolled. Propiverine 20 mg/day was administered for 12 weeks to 70 patients who desired the further improvement of OAB symptoms and 3 who had intolerable adverse events of previous drugs. The OABSS and postvoid residual urine volume (PVR) were determined before and at 4 and 12 weeks of treatment. Results. Of 73 patients enrolled (29 males and 44 females, median age 71 years), 52 completed the protocol treatment. The OABSS was significantly improved by propiverine treatment (9.0 at baseline, 6.2 at 4 weeks, 6.3 at 12 weeks (P < 0.001)). The scores of OAB symptoms (nighttime frequency, urgency and urge incontinence) except daytime frequency also improved significantly. No increase in PVR was observed. The most frequent adverse event was dry mouth (13.7%), followed by constipation (6.8%). Conclusions. Propiverine is useful to improve OAB for patients who poorly respond to solifenacin, tolterodine or imidafenacin.


European Urology | 1991

Transitional cell carcinoma of the bladder or renal pelvis in children.

Masahiro Yanase; Taiji Tsukamoto; Yoshiaki Kumamoto; Yoshio Takagi; Naoto Mikuma; Akihiko Iwasawa; Nobuo Kondo

Transitional cell carcinoma (TCC) of the bladder or renal pelvis is rare in children. We report 2 children with TCC of the bladder and 1 with TCC of the renal pelvis. One of the two children with bladder carcinoma experienced frequent intravesical recurrences, which is in contrast to the usual clinical course of bladder carcinoma in children. In the 3rd child, renal pelvic carcinoma was found incidentally in a renal pelvis specimen removed during pyeloplasty.


Journal of Infection and Chemotherapy | 2008

Gatifloxacin treatment for chronic prostatitis: a prospective multicenter clinical trial

Yasuharu Kunishima; Koh Takeyama; Satoshi Takahashi; Masanori Matsukawa; Mikio Koroku; Hitoshi Tanda; Toshiaki Tanaka; Takaoki Hirose; Akihiko Iwasawa; Masahiro Nishimura; Kouichi Takeda; Nobukazu Suzuki; Hiroki Horita; Akifumi Yokoo; Taiji Tsukamoto

Antimicrobial treatment is usually used for chronic prostatitis. However, the efficacy of such treatment has not been fully evaluated. We conducted a study to evaluate the efficacy of gatifloxacin for patients with chronic prostatitis using the Japanese version of the National Institutes of Health Chronic Prostatitis Symptom Index (JPN-NIH CPSI). The study included 46 patients for final analysis. Patients who were younger than 65 years of age were treated with 200 mg gatifloxacin twice daily, and those who were 65 years and older were treated with 100 mg gatifloxacin twice daily, for 4–8 weeks. The study consisted of 10 patients in category II, 13 in category IIIA, 11 in category IIIB, and 12 who were unclassified. The gatifloxacin treatment resulted in significant reductions in the scores on the JPN-NIH CPSI. Of the total number of patients, 58.1% and 27.9% were 25% and 50% responders, respectively, 4 weeks after treatment, and these figures improved to 66.7% and 33.3%, respectively, 8 weeks after treatment. No significant difference was found in the changes in symptom scores between Category II and Category IIIA/IIIB groups. In conclusion, gatifloxacin treatment improved the symptoms in patients with chronic bacterial and nonbacterial prostatitis. This study is the first in this country to evaluate the efficacy of antimicrobial treatment for chronic prostatitis by using the NIH CPSI.

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Taiji Tsukamoto

Sapporo Medical University

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Naoya Masumori

Sapporo Medical University

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Takaoki Hirose

Sapporo Medical University

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Nobukazu Suzuki

Sapporo Medical University

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Yoshiaki Kumamoto

Sapporo Medical University

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Jiro Hashimoto

Sapporo Medical University

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Koji Ichihara

Sapporo Medical University

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