Jun Nishiguchi

Extracorporeal magnetic innervation treatment for urinary incontinence

Abstract  Background:  Extracorporeal magnetic innervation (ExMI) is a new technology used for pelvic muscle strengthening for the treatment of stress urinary incontinence. We explored whether this new technology is effective for patients with urge incontinence, as well as those with stress urinary incontinence.

Effects of isolectin B4‐conjugated saporin, a targeting cytotoxin, on bladder overactivity induced by bladder irritation

In order to clarify the functional role of the isolectin B4 (IB4)‐binding afferent pathway in the micturition reflex, we investigated the effects on bladder activity of intrathecal application of the IB4–saporin conjugate, a targeting cytotoxin that destroys neurons binding IB4. In rats, IB4–saporin (2.5 µm) or vehicle was administered through an intrathecal catheter implanted at the level of the L6–S1 spinal cord. Three weeks after IB4–saporin administration, cystometry in conscious animals revealed a reduction in bladder overactive responses induced by intravesical capsaicin or ATP infusion without affecting normal voiding function. In histochemical studies, double staining for IB4 and saporin was detected in L6 dorsal root ganglia (DRG) neurons 2 days after the treatment. Three weeks after the treatment, the area in lamina II of the L6 spinal cord stained with IB4 was significantly reduced compared with the area stained in control rats. The staining in the L1 spinal cord was not affected. The percentage of neurons in the L6 DRG intensely labeled with IB4 was also reduced in IB4–saporin‐treated rats. These results indicate that intrathecal treatment with the IB4–saporin conjugate at the level of L6–S1 spinal cord, which reduces IB4 afferent nerve terminal staining in lamina II of the L6 spinal cord as well as the number of IB4‐binding neurons in L6 DRG, suppressed bladder overactivity induced by bladder irritation without affecting normal micturition. Thus targeting IB4‐binding, non‐peptidergic afferent pathways sensitive to capsaicin and adenosine 5′‐triphosphate may be an effective treatment for overactivity and/or pain responses in the bladder.

Change in Parameters before and after Alpha-1-Blocker Therapy for Men with Lower Urinary Tract Symptoms Using Color Doppler Ultrasound Urodynamics: Possible Application for Prediction of Clinical Outcome

Introduction: We previously developed a noninvasive video urodynamic study using color Doppler ultrasonography. We sought the best flow velocity-related parameter which would allow prediction of an improvement in lower urinary tract symptoms (LUTS) after α₁-blocker treatment. Methods: Twenty-two men with benign prostatic hyperplasia who were treated with a nonselective α₁-blocker (urapidil) were included. Subjective symptoms were evaluated using the International Prostate Symptom Score (IPSS) before and after α₁-blocker treatment. We measured the flow velocities using a transperineal ultrasound technique in the distal prostatic urethra just proximal to the external urethral sphincter (V₁) and in the sphincteric urethra (V₂), and used them to obtain the velocity ratio (VR = V₁/V₂). The corresponding functional cross-sectional areas of the urethra at these two sites (A₁ and A₂) were calculated as Q_max/V. All these parameters obtained by the velocity-flow urodynamics were compared before treatment and after 4 weeks. Results: After treatment, V₁ and VR were decreased, and A₁ was increased. V₂ correlated best with the change in IPSS before and after α₁-blocker therapy, with Spearman’s rho of 0.584. All men with V₂ exceeding 50 cm/s did not show an improvement in the LUTS. Conclusions: The maximum flow velocity at the sphincteric urethra (V₂) can predict the subjective outcome of α₁-blocker treatment. The velocity-flow parameters changed after α₁-blocker treatment. We confirmed that the transperineal ultrasound urodynamic study is not only noninvasive but also informative.