H. Masuda

Intravesical instillation of human urine after oral administration of trospium, tolterodine and oxybutynin in a rat model of detrusor overactivity

To study the effects of antimuscarinics excreted into human urine on normal bladder in a rat model of detrusor overactivity.

Roles of Peripheral and Central Nicotinic Receptors in the Micturition Reflex in Rats

PURPOSEnWe investigated the effects of nicotinic acetylcholine receptor activation in the bladder and central nervous system on the micturition reflex in urethane anesthetized rats.nnnMATERIALS AND METHODSnThe effects of nicotinic acetylcholine receptor activation on bladder activity were examined during continuous infusion cystometrogram. Nicotine with or without the nicotinic acetylcholine receptor antagonist mecamylamine (Sigma Chemical Co., St. Louis, Missouri) was administered intravesically, intrathecally or intracerebroventricularly in normal or capsaicin pretreated rats. We also examined nicotine induced responses in dissociated bladder afferent neurons from L6 to S1 dorsal root ganglia that were sensitive to capsaicin using whole cell patch clamp recordings.nnnRESULTSnIntravesical nicotine (1 to 10 mM) significantly decreased intercontraction intervals in dose dependent fashion. This excitatory effect was abolished by co-application of mecamylamine (3 mM) as well as by capsaicin pretreatment. On patch clamp recordings 300 muM nicotine evoked rapid inward currents that were antagonized by mecamylamine in capsaicin sensitive bladder afferent neurons. Intrathecal and intracerebroventricular administration of nicotine (10 mug) decreased and increase intercontraction intervals, respectively. Each effect was antagonized by mecamylamine (50 mug) administered intrathecally and intracerebroventricularly. The spinal excitatory effect was significantly inhibited by the N-methyl-D-aspartate receptor antagonist (+)-MK-801 hydrogen maleate (20 mug) given intrathecally or by capsaicin pretreatment, although the effects of capsaicin pretreatment were significantly smaller than those of (+)-MK-801 hydrogen maleate.nnnCONCLUSIONSnThese results indicate that nicotinic acetylcholine receptor activation in capsaicin sensitive C-fiber afferents in the bladder can induce detrusor overactivity. In the central nervous system nicotinic acetylcholine receptor activation in the spinal cord and brain has an excitatory and an inhibitory effect on the micturition reflex, respectively. In addition, the nicotine induced spinal excitatory effect may be mediated by the activation of glutamatergic mechanisms.

Muscarinic receptor activation in the lumbosacral spinal cord ameliorates bladder irritation in rat cystitis models

To investigate whether activation of spinal cholinergic pathways affects bladder activity in rats with chemical cystitis induced by acetic acid (AA) and cyclophosphamide (CYP).

Effects of intrathecal injection of a hyperpolarization-activated channel (Ih) inhibitor ZD7288 on bladder function in urethane-anesthetized rats†

The role of Ih channels at the spinal level in the control of bladder function was examined in urethane anesthetized female rats.

Gasless Single Port Surgery for Renal Cell Carcinoma: Minimum Incision Endoscopic Surgery

Advances in minimally invasive urologic surgery have accumulated rapidly in recent years with the advent of laparoscopic and robot-assisted surgeries (Clayman, 1991; Guillonneau, 1999; Dasgupta, 2009; Lee, 2009). The procedures for renal cell carcinoma (RCC), radical nephrectomy and partial nephrectomy are among those that have benefited from such innovation. Both laparoscopic surgery and robot-assisted surgery have markedly reduced the invasiveness of surgeries compared to conventional open procedures; laparoscopic surgery is characterized by the use of endoscopy, insufflation with carbon dioxide (CO2) gas, and insertion of instruments from several trocar ports, while robot-assisted surgery also incorporates stereovision and state-of-the-art movable instruments.

Renal Cell Carcinoma in Dialysis Patients with End Stage Renal Disease: Focus on Surgery and Pathology

In 1977, Dunnill et al. from Oxford at first reported that 14 of 30 dialysis patients with end stage renal disease (ESRD) examined at autopsy had acquired cystic disease of the kidney (ACDK) and that six of these 14 patients had renal cell carcinoma (RCC), including one with distant RCC metastatsis.1 It is now well established that patients with ESRD are more prone to RCCs with an incidence of approximately 3 to 5 %.2-5 These studies may misrepresent the true incidence RCC because they primarily relay upon screening radiology, particularly ultrasonography (US), for detection. Better estimate was provided by a single-center study in which most renal transplant patients undergo ipsilateral native nephrectomy at surgery. Based upon strict pathologic criteria reported by Denton et al., prevalence of ACDK, renal adenoma and RCC and oncocytoma were found in 33%, 14%, 4.2% and 0.6% of 260 patients6, which may be lower than the true incidence given that only one kidney was removed. Chen et al. found higher incidence of RCCs vs. the general population, with a standardized incidence ratio of RCC in dialysis patients of 24.1 (p <.01)7. Ishikawa et al. were able to demonstrate that time spent on haemodialysis was the most important risk factor for ACDK and also for the development of RCC. This important observation did highlight the key features of ACDK developing on haemodialysis and apparently increasing the likelihood of RCC2,8,9. Hughson’s work suggested that during this time there was a progression of cystic lesions from simple to complex or hyperplastic cysts and on to renal tumor formation10. A recent nation-wide survey in Japan revealed a 15-fold increase in the number of dialysis patients with RCC in the last 2 decades8. Reasons for this rapid increase can be postulated as follows: the increasing number of dialysis patients: the increasing duration of dialysis in these patients: and the prevalence of tumor screening in dialysis patients by imaging studies. The prevalence of ACDK in the haemodialysis population in Japan appears to be higher than that in the USA or Europe and patient survival on dialysis in Japan is significantly longer. These are probably because of different patterns of primary renal disease and reduced cardiovascular comorbidity compared with Western populations11. The presence of RCCs also appears to vary within different populations. Kojima’s study of 2624