Kazuyoshi Iijima

Mechanosensitive primary bladder afferent activity in rats with and without spinal cord transection.

PURPOSE Spinal cord injury induces functional and morphological changes in bladder afferent pathways. However, direct evidence for changes in the excitability of afferent nerve activity primarily originating from the bladder has not been clearly demonstrated. Thus, we determined the characteristics of peripheral mechanosensitive bladder afferents in the pelvic nerve and possible afferent changes in Adelta and C fibers after spinal cord injury. MATERIALS AND METHODS Adult female rats were divided into 2 groups, including spinal cord injured and neurologically intact animals. In the spinal cord injury group the spinal cord was transected at Th9 at 4 weeks before functional experiments. For single unit afferent activity monitoring fine filaments were dissected from the L6 dorsal root and bladder afferent fibers were identified. Single unit afferent activity was studied during constant filling with saline. RESULTS Two afferent patterns were linked to small phasic increases in intravesical pressure during bladder filling, including accelerated and nonaccelerated types. The incidence of the accelerated type was significantly higher in the spinal cord injury group than in the neurologically intact group regarding Adelta and C fibers. However, we found no relationship between conduction velocity and the functional properties of bladder mechanosensitive afferent fibers in neurologically intact or spinal cord injured rats. CONCLUSIONS Results indicate that mechanosensitive bladder afferent activity has several patterns and is facilitated after spinal cord injury, especially in concert with small bladder contractions (micromotions). The functional properties of these individual afferent fibers are not related in an obvious manner to their conduction velocity and, thus, probably the afferent fiber type.

Effects of intravesical instillation of ATP on rat bladder primary afferent activity and its relationship with capsaicin-sensitivity.

Previous studies have suggested that ATP has a role in mechano‐afferent transduction, at least partly mediated by nerves other than capsaicin (Cap)‐sensitive nerves. We investigated the direct effect of ATP on single fiber activity (SFA) of the primary bladder afferent nerves and its relationship with Cap‐sensitivity.

Comparison of the effects of oestrogen deficiency and old age on primary bladder afferent activity and voiding behaviour in the ageing female rat

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Importance of Transition Zone Biopsies in Patients Undergoing Ultrasound-Guided Prostate Systemic Biopsies for the First Time

Introduction: We analyze the efficacy of routine transition zone biopsies in patients undergoing ultrasound-guided systemic prostate biopsies for the first time because of a suspicious digital rectal examination or an elevated serum prostate-specific antigen (PSA) level. Patients and Methods: During systemic prostate biopsy two or four additional transition zone biopsies were performed in 192 consecutive patients: in 182 because of a serum PSA concentration >4.1 ng/ml and in 10 because of a suspicious digital rectal examination and a serum PSA level <4.0 ng/ml. Results: The overall prostate cancer detection rate was 37.5% (72/192). In 24 patients (33.3%), cancer was only detected in the peripheral zone, in 3 (4.2%) only in the transition zone, and in 45 (62.5%) in both zones. Conclusion: Transition zone biopsies performed at the first time of systemic prostate biopsy seem to have a low efficacy.

Analysis of the Pressure-Flow Study in Weak Detrusor Patients with Benign Prostatic Hypertrophy

Objective: Pressure‐flow study is a method used to evaluate the degree of bladder outlet obstruction and the strength of detrusor contractility during voiding. However, whether or not the operation for benign prostate hyperplasia should be avoided in detrusor underactivity patients remains controversial. To address this, we performed a retrospective analysis of our pressure‐flow study data for benign prostate hyperplasia patients. We especially focused on the backgrounds of patients with weak detrusor contractility.