Yasuhiro Nishiyama

Publications (3)6.6 Total impact

• Article: Effects of purified newly developed botulinum neurotoxin type A in rat prostate.

  Yasuhiro Nishiyama, Teruhiko Yokoyama, Kazuhito Tomizawa, Kikuo Okamura, Yumiko Yamamoto, Hideki Matsui, Keiji Oguma, Atsushi Nagai, Hiromi Kumon
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  ABSTRACT: To investigate the efficacy of a newly purified neurotoxin (NTX) in male rat prostates. Several reports have suggested that intraprostatic injection of botulinum toxin type A has demonstrated efficacy against symptomatic benign prostatic hyperplasia. NTXs associate with nontoxic components and form large complexes designated "progenitor toxins." In general, progenitor toxins are used, because they are easily obtained and are more stable than NTXs. However, they have side effects for some patients in whom anti-progenitor toxins, including anti-NTX antibodies, are produced after several injections. We purified NTXs without their nontoxic components using a simple procedure. Adult male Sprague-Dawley rats were injected with 5 U of NTX or saline into their prostates, which were harvested and weighed after 1 or 4 weeks. The effects of the NTX on the prostate were histologically and immunohistochemically studied using hematoxylin-eosin, synaptophysin, and terminal deoxynucleotidyl-mediated deoxyuridine triphosphate nick end labeling staining. In the NTX-treated rats, the prostate weight was reduced and atrophy and diffuse apoptosis were observed. Moreover, synaptophysin-positive cells in the epithelium were decreased after NTX injection. Intraprostatic NTX injection induces prostate apoptosis and atrophic change in the rat prostate. These results suggest that NTX injection might be a promising material for treatment of patients with benign prostatic hyperplasia.
  Urology 05/2009; 74(2):436-9. · 2.43 Impact Factor
• Article: Tolerability and morbidity of urodynamic testing: a questionnaire-based study.

  Teruhiko Yokoyama, Kunihiro Nozaki, Hiroyuki Nose, Miyabi Inoue, Yasuhiro Nishiyama, Hiromi Kumon
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  ABSTRACT: To determine the tolerability and morbidity rate of multichannel urodynamics (UDS). A total of 154 consecutive patients were included in the present study; 87 men and 67 women underwent UDS and completed a questionnaire. All patients undergoing UDS were given a two-part questionnaire. The first part, given immediately after UDS, contained four questions regarding pain, embarrassment, and physical burden (assessed with a visual analogue scale on which 0 = not at all, 10 = unbearable), as well as willingness to undergo UDS again. The second part, given within 2 weeks after UDS, contained five questions regarding micturition pain, gross hematuria, dysuria, cloudy urine, and fever episodes after UDS. Urine specimens were also analyzed. The mean (+/-SD) degrees of pain, embarrassment, and physical burden were 2.27 +/- 2.53, 2.59 +/- 2.69, and 1.76 +/- 2.43, respectively, and 73.6% of men and 80.6% of women were willing to repeat UDS. The most common complaint after UDS was micturition pain. Two men and 1 woman had fever after UDS; there was no relationship between fever and urinary tract infections. Urinalysis showed that 4.6% of men and 7.5% of women had leukocyturia after the investigation. The complication rates of UDS were relatively low. For most patients, UDS were tolerable and acceptable. Proper informed consent is necessary.
  Urology 08/2005; 66(1):74-6. · 2.43 Impact Factor
• Article: Varicocele rupture due to sexual intercourse.

  Yasuhiro Nishiyama, Atsushi Nagai, Yasutomo Nasu, Masami Watanabe, Norihiro Kusumi, Koichi Monden, Hiromi Kumon
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  ABSTRACT: Varicocele rupture was diagnosed in a 23-year-old man who presented with swelling and pain in the left scrotum after sexual intercourse. Color Doppler ultrasonography revealed blood flowing into the space surrounding the left testis, a hematoma and reflux of blood in the left spermatic vein. Varicocele rupture is a very rare condition and there have been only five reported cases.
  International Journal of Urology 07/2005; 12(6):585-7. · 1.75 Impact Factor