Kazuto Komatsu

Diagnostic value of intravesical lidocaine for overactive bladder

PURPOSEnTo determine the diagnostic use of intravesical lidocaine, we evaluated its effects on the overactive bladder in patients with brain lesions, spinal lesions, benign prostatic hyperplasia (BPH) and idiopathic overactive bladder.nnnMATERIALS AND METHODSnCystometry was performed before and 15 minutes after intravesical instillation of 20 ml. 4% lidocaine in 57 patients with an overactive detrusor in the storage phase.nnnRESULTSnThe percentage increase in bladder capacity for patients with spinal lesions was 136%, compared to 56%, 29% and 41% for patients with brain lesions, BPH and idiopathic bladder overactivity, respectively (significant difference p <0.01 to 0.05). Of the patients with an increase of 50% or more 55% had brain lesions, 80% spinal lesions, 23% BPH and 31% idiopathic bladder overactivity. The incidence of the disappearance of detrusor contractions in patients with spinal lesions was greater than that in the others.nnnCONCLUSIONSnThese results suggest that intravesical instillation of 4% lidocaine is useful for identification of overactive bladder attributable to spinal or other lesions.

CHANGE IN BLADDER CONTRACTILITY ASSOCIATED WITH BLADDER OVERACTIVITY IN RATS WITH CEREBRAL INFARCTION

PURPOSEnTo evaluate the contractile properties of overactive bladder from rats in the chronic stage of experimental cerebral infarction.nnnMATERIALS AND METHODSnCystometry was performed in conscious male S-D rats after inducing occlusion of the left middle cerebral artery. Bladder muscle strips were evaluated for force development in response to field stimulation, acetylcholine and KCl. By measuring the contractile response to field stimulation after adding atropine and alpha,beta-methylene-ATP, contributions of cholinergic and purinergic transmission were determined.nnnRESULTSnBladder capacity of cerebral-infarcted rats was <50% of the capacity of sham-operated rats and significantly less than that of sham-operated rats even 4 months after surgery. There was no significant difference in bladder weight between sham-operated rats and cerebral-infarcted rats. No differences in the contractile response of detrusor strips to field stimulation and acetylcholine, or in the relative contribution of cholinergic and purinergic transmission to the contractile response, were observed over time or between strips from sham-operated rats and cerebral-infarcted rats. KCl induced significantly less contraction in strips from 4 month infarcted rats than in strips from 4 month sham-operated rats, 2 week infarcted rats and 2 month infarcted rats.nnnCONCLUSIONSnThis animal model will be useful for chronic studies on the mechanism of detrusor hyperactivity (DH).

A causative factor of copulatory disorder in rats following social stress

PURPOSEnWe investigated the causative role of testosterone in copulatory disorder and the expression of c-fos messenger (m)RNA in the medial preoptic area in rats after social stress.nnnMATERIALS AND METHODSnTo generate copulatory disorder rats in the experimental defeated group were attacked by residents for 10 minutes daily for 7 consecutive days (social stress). We then investigated the effect of repeat defeat on the frequency of mounting behavior and plasma testosterone levels. The effects of testosterone replacement and/or apomorphine (100 microg./kg. subcutaneously), a dopamine receptor agonist, on the frequency of mounting behavior were also studied. After experiencing social stress the brain area within the medial preoptic area was removed for analysis of c-fos and androgen receptor mRNA expression. Real-time reverse transcription-polymerase chain reaction was done to analyze gene expression.nnnRESULTSnRats in the defeated group showed a reduced frequency of mounting behavior and a decrease in plasma testosterone levels compared with values in control rats (p <0.01). After testosterone replacement the frequency of mounting behavior became significantly higher than that of socially stressed rat (p <0.05) but did not achieve control levels. The frequency of mounting behavior by socially stressed rats after apomorphine treatment was significantly higher than that of vehicle treated rats (p <0.05) but the frequency produced by the combination of testosterone replacement and apomorphine injection did not achieve control levels. After the social stress experience c-fos mRNA expression was significantly increased compared with that in control rats (p <0.05). The expression of androgen receptor mRNA was not affected by social stress. Testosterone replacement significantly reduced the expression of c-fos mRNA in the medial preoptic area (p <0.05).nnnCONCLUSIONSnOur results indicate that a reduction in plasma testosterone may have a causative role in copulatory disorder induced by social stress. Changes in c-fos mRNA expression in the medial preoptic area correlated with copulatory disorder and, thus, they are suitable for monitoring that disorder.

EFFECTS OF MK-801 ON BLADDER OVERACTIVITY IN RATS WITH CEREBRAL INFARCTION

PURPOSEnOur objective was to evaluate the underlying mechanisms of neurogenic voiding dysfunction following cerebral infarction.nnnMATERIALS AND METHODSnThe left middle cerebral artery (MCA) was occluded using 4-0 monofilament nylon thread in male S-D rats. Cystometric examination was performed in unanesthetized and urethane-anesthetized rats through a catheter chronically implanted in the dome of the bladder.nnnRESULTSnBladder capacity of unanesthetized or urethane anesthetized rats was significantly reduced just after occlusion of the left MCA; 2 weeks after the occlusion, the capacity was less than half that in sham-operated rats. Intravenous administration of N-methyl-d-aspartate (NMDA) receptor antagonist MK-801 to the unanesthetized sham-operated rats led to a marked dose-dependent decrease in bladder capacity. Its administration to unanesthetized rats with cerebral infarction resulted in a slight decrease in bladder capacity. In the urethane-anesthetized state, the bladder capacity of the rats with cerebral infarction was significantly increased by MK-801, 0.1 mg./kg., without inhibiting the contraction pressure or increasing the amount of residual urine. A high dose (1 mg./kg.) of MK-801 was required to increase the bladder capacity of sham-operated rats. This led to an inhibition of contraction pressure and an increase in residual urine.nnnCONCLUSIONnResults in urethane anesthetized rats indicate that NMDA glutamatergic transmission is important in the overactivity of the bladder following a cerebral infarction. This model is useful in studying the neurogenic voiding dysfunction observed in patients with cerebrovascular disease.

Free-to-total prostate-specific antigen (PSA) ratio contributes to an increased rate of prostate cancer detection in a Japanese population screened using a PSA level of 2.1–10.0 ng/ml as a criterion

BackgroundAlthough the free-to-total prostate-specific antigen (PSA) ratio (f/t ratio) is low in prostate cancer, its usefulness in mass screening remains unclear. We examined the clinical usefulness of the f/t ratio for screening in a Japanese population.MethodsSince 2000, we have performed PSA screening in Japanese men aged 55–69 years. From 2000 to 2002, patients with total PSA (tPSA) levels over 2.1 ng/ml were referred to the urological clinic for secondary screening, regardless of the f/t ratio. We analyzed both the tPSA level and the f/t ratio in prostate cancer patients, and since 2003, subjects with tPSA levels ranging from 2.1–10.0ng/ml and f/t ratios higher than 0.22 have not been referred for secondary screening. Here, we report the results of tPSA screening, comparing findings in the two periods (2000–2002 and 2003–2005).ResultsBetween 2000 and 2005, we performed the tPSA screening test in 27 730 men, and detected 214 cases of prostate cancer. Sixty patients (28.0%) showed tPSA levels between 2.1 and 4.0ng/ml. There were no differences in cancer detection rates between the two periods in the populations referred for an initial screening. However, the percentage of individuals referred for secondary screening decreased from 17.0% to 13.0% during the later period (P < 0.001). The cancer detection rate in all patients with biopsies rose from 13.5% in the earlier period to 22.7% in the later period for the group with tPSA between 2.1 and 10.0ng/ml (P < 0.001).ConclusionThe f/t ratio may be a useful additional screening parameter for patients showing tPSA levels between 2.1 and 10.0ng/ml on their initial screening examination.

Integral Laser Photodynamic Treatment of Refractory Multifocal Bladder Tumors

Integral photodynamic therapy with hematoporphyrin derivative was performed on 35 patients who had resistant transitional cell carcinoma of the bladder, mainly carcinoma in situ. The light source was an argon ion pumped dye laser (wavelength 630 nm.) using rhodamine B. Two types of laser light scattering diffuser developed at our department were used: a motor driven laser light scattering diffuser with computer regulation, and an endoscope modified light scattering diffuser tipped with a small quartz bulb containing a lipid nutritious solution as the scattering medium. The total energy density used was 10 to 30 J./cm.2. Of the 35 patients 24 (68.6%) achieved a complete response and 5 (14.3%) a partial response at 3 months. In 10 of the 24 patients there was no recurrence with an average tumor-free interval of 20.9 +/- 16.7 months, ranging from 5 to 60 months. Bladder capacity was decreased to approximately 150 ml. for 3 months after the integral photodynamic therapy without any evidence of hydronephrosis on excretory urograms, except for 2 patients who had a contracted bladder before photodynamic therapy. Integral photodynamic therapy may prove to be useful for the treatment of carcinoma in situ of the bladder.

CONTRIBUTION OF CEREBRAL NITRIC OXIDE TO BLADDER OVERACTIVITY AFTER CEREBRAL INFARCTION IN RATS

PURPOSEnWe investigated the contribution of cerebral nitric oxide to neurogenic voiding dysfunction after cerebral infarction.nnnMATERIALS AND METHODSnThe left mid cerebral artery in female Sprague-Dawley rats was occluded with 4-zero monofilament nylon thread. Bladder activity was monitored during infusion cystometrography. Time or dose dependent effects of intracerebral ventricular administration of the nonselective nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME), were investigated in conscious, sham operated and cerebral infarcted rats. The selective neuronal nitric oxide synthase inhibitor 1-(2-trifluoromethylphenyl) imidazole was also administered to determine the participation of nitric oxide synthase subtypes. Cross-sectional infarct area was measured and infarct volume was calculated 12 hours after mid cerebral artery occlusion.nnnRESULTSnBladder capacity was reduced by 54% 30 minutes after mid cerebral artery occlusion. L-NAME significantly increased bladder capacity in a dose and time dependent manner in cerebral infarcted rats but had no effect on sham operated rats. L-NAME (50 microg./kg.) administered 3 or 5 hours after occlusion significantly increased bladder capacity. This effect of L-NAME was reversed by injecting 250 microg. L-arginine per rat, which alone did not produce any significant change in bladder capacity in cerebral infarcted rats. Administration of 1-(2-trifluoromethylphenyl) imidazole also significantly increased bladder capacity in these rats. On the other hand, 5 microg. of the nitric oxide donor FK-409 per rat reduced bladder capacity for 10 to 15 minutes. None of the drugs affected infarct volume.nnnCONCLUSIONSnThese results indicate that supraspinal nitric oxide has an important role in bladder overactivity after cerebral infarction but it does not affect normal micturition in rats. This finding suggests a central mechanism sensitive to nitric oxide for bladder overactivity after cerebral infarction.

Forebrain muscarinic control of micturition reflex in rats

Functional contribution of the cholinergic pathway between the frontal cortex and basal nucleus of Meynert to micturition reflex was investigated. Male Wistar rats were subjected to bilateral lesion of the basal forebrain by ibotenic acid (IA) injection (7.5 microg/rat on each side) (BF rats). Phosphate buffered saline (PBS) was injected into control rats (sham operated rats; SO rats). Cystometrograms were obtained from conscious BF and SO rats 7-10 days after IA/PBS injection. Bladder capacity (BC) of BF rats was significantly smaller than that of SO rats (approximately 43.7%) and was accompanied by decrease in choline-acetyltransferase activity in the frontal cortices. Oxotremorine M, a muscarinic receptor agonist, increased BC in BF rats, while pirenzepine, an M1 muscarinic receptor antagonist, counteracted the effect of the oxotremorine M-induced increase in BC. Injection of oxotremorine M into the dorsal pontine tegmentum (DPT) reduced BC in BF and SO rats, while injection of pirenzepine had no effect on cystometrograms. These findings indicate that the M1 muscarinic receptor plays a part in the forebrain inhibitory mechanisms involved in the micturition reflex and that muscarinic receptor in the DPT contributes to excitatory control of micturition reflex.

Pathological effects of neoadjuvant hormonal therapy help predict progression of prostate cancer after radical prostatectomy.

Background: It is not clear whether pathological changes following neoadjuvant hormonal therapy (NHT) prior to radical prostatectomy have any value as predictors of progression in prostate cancer.

Expression of neural plasticity related gene in the pontine tegmental area of rats with overactive bladder after cerebral infarction.

PURPOSEnWe investigated the expression of the neural plasticity related genes c-fos, zif268, c-jun, brain-derived neurotrophic factor and tissue plasminogen activator in the pontine tegmental area in rats with overactive bladder induced by cerebral infarction.nnnMATERIALS AND METHODSnCerebral infarction was induced by left middle cerebral artery occlusion in female Sprague-Dawley rats. Bladder activity was monitored by continuous infusion cystometrography in awake rats. Specimens were obtained from the pontine tegmental area 1, 3, 5, 12 and 24 hours after cerebral infarction or sham operation. The effect of 0.1 mg./kg. intravenously of the N-methyl-d-aspartate glutamatergic receptor antagonist MK-801 on bladder activity, and c-fos and zif268 expression after middle cerebral artery occlusion were studied. Real-time reverse transcriptase-polymerase chain reaction was performed with the LightCycler system (Roche Diagnostics, Mannheim, Germany) to evaluate cerebral infarction influences on gene expression in the pontine tegmental area.nnnRESULTSnBladder capacity in cerebral infarcted rats was significantly reduced 1 to 24 hours after middle cerebral artery occlusion compared with that of sham operated rats (p <0.05 to 0.01). One hour after occlusion mean c-fos messenger (m)RNA expression plus or minus standard error had significantly increased to 18.9 +/- 4.0 in terms of its density relative to the outer control in a sample obtained immediately after occlusion compared with that in sham operated rats (p <0.05). It returned to the control level within 3 hours after occlusion. Mean zif268 mRNA expression significantly increased to a relative density of 3.2 +/- 1.4 3 hours after middle cerebral artery occlusion (p <0.01) and returned to the control level within 5 hours after occlusion. The expressions of c-jun, brain-derived neurotrophic factor and tissue plasminogen activator was not influenced by occlusion. Pretreatment with MK-801 inhibited bladder overactivity and significantly reduced the expression of c-fos and zif268 mRNA in the pontine tegmental area.nnnCONCLUSIONSnThese results indicate that the development of bladder overactivity after middle cerebral artery occlusion is mediated by activation of an N-methyl-d-aspartate receptor and accompanied by an increase in c-fos and zif268 mRNA expression in the pontine tegmental area.