Effect of insulin-like growth factor-1 and insulin-like growth factor binding protein-3 complex in cavernous nerve cryoablation.

The purpose of this work was to study the effect of insulin-like growth factor 1 (IGF-1) and its binding protein (IGFBP-3) on the recovery of erectile function in a rat model for neurogenic impotence. In all, 28 male Sprague-Dawley rats were divided into four groups: seven underwent a sham operation; seven underwent bilateral cavernous nerve freezing (control group); seven underwent bilateral cavernous nerve freezing followed by intraperitoneal injection of IGF-1; and seven underwent bilateral cavernous nerve freezing followed by intraperitoneal injection of IGFBP-3. Erectile response was assessed by cavernous nerve electrostimulation at 3 months, and samples of penile tissue were evaluated histochemically for nitric oxide synthase (NOS)-containing fibers. In the sham and IGF-1 group, there were significantly higher maximal intracavernous pressures compared to the IGFBP-3 complex and the control group. Correspondingly in the cavernosum, there were significantly more NOS-containing nerve fibers in the sham and IGF-1 groups. In conclusion, administration of IGF-1 can facilitate the regeneration of NOS-containing nerve fibers in penile tissue and enhance the recovery of erectile function after bilateral cavernous nerve cryoablation. The reverse effect was noted with the IGFBP-3 complex injection.

The treatment of priapism--when and how?

Priapism is a condition first described by Tripe in 1845. It has been defined as a pathological condition of penile erection that persists beyond or is unrelated to sexual stimulation. Two variants of priapism have been well described. The ischemic priapism (also known as low-flow priapism) and nonischemic priapism (or high flow priapism) have unique and distinct causes. It is important to distinguish these two conditions as the treatment for each is different. This review will focus on the two types of priapism and the appropriate diagnostic work-up for each. As well, the medical and surgical treatment options for these two conditions will be described in detail. A third entity known as stuttering priapism will also be discussed as will its unique treatment alternatives.

The effect of vascular endothelial growth factor and brain-derived neurotrophic factor on cavernosal nerve regeneration in a nerve-crush rat model.

OBJECTIVE: To test the hypothesis that an intracavernosal injection with brain-derived neurotrophin factor (BDNF) and vascular endothelial growth factor (VEGF) can facilitate nerve regeneration and recovery of erectile function after cavernosal nerve injury. MATERIALS AND METHODS: The study included 25 Sprague-Dawley rats; four had a sham operation, seven bilateral nerve crushing with no further intervention, and 14 bilateral nerve crushing with either an immediate (seven) or delayed for 1 month (seven) intracavernosal injection with BDNF+VEGF. Erectile function was assessed by cavernosal nerve electrostimulation at 3 months, and neural regeneration by NADPH-diaphorase staining and tyrosine hydroxylase (TH) staining of penile tissue and major pelvic ganglia (MPG). RESULTS: After nerve crushing, the functional evaluation at 3 months showed a lower mean (SD) intracavernosal pressure (ICP) with cavernosal nerve stimulation, at 33.9 (15.3) cmH2O, than in the sham group, at 107.8 (18.1) cmH2O. With an immediate injection with BDNF+VEGF the ICP was significantly higher than in the controls, at 67.8 (38.5) cmH2O. Even delayed injection with BDNF+VEGF improved the ICP, to 78.0 (21.8) cmH2O. Histological analysis of specimens stained for NADPH and TH showed a significant change in the morphology of terminal branches of the cavernosal and dorsal nerves, and the staining quality of the neurones in the MPG. The number of positively stained nerve fibres tended to revert to normal after treatment with BDNF+VEGF. CONCLUSION: An intracavernosal injection with BDNF+VEGF appears to both prevent degeneration and facilitate regeneration of neurones containing neuronal nitric oxide synthase in the MPG, dorsal nerve and intracavernosal tissue. Therefore it might have therapeutic potential for enhancing the recovery of erectile function after radical pelvic surgery.

Modern pharmacotherapy for erectile dysfunction: evolving concepts with central and peripheral acting agents.

Pharmacotherapy for men experiencing erectile dysfunction has undergone dramatic advances over the past 5 years with the introduction of an effective oral agent. Sildenafil has increased the pool of couples seeking treatment for this important health issue as well as expanding the numbers of physicians treating it. Research into the growing field of erectile dysfunction is expanding at a rapid pace. Independent investigators worldwide now regularly contribute to our body of scientific knowledge. Novel oral therapies targeted at specific points along the erectile cascade are undergoing pre-clinical and early phase registration trials with the promise of rapid action, extended duration of responsiveness and an improved side effect profile. In this review, we have highlighted recent information on the next generation of phosphodiesterase inhibitors and summarized the evolving research into centrally acting agents, which may lead to effective combination therapy.

Simulation for localized prostate cancer: a comparison of urethrography techniques.

Forty-five patients having conventional fluoroscopic, or CT scan simulation of the prostate gland from January 1999 to June 1999 were studied. Patients were consecutively assigned (not randomized) in groups of 15 to 3 different urethrography techniques: air contrast alone (group 1), hypaque contrast alone (group 2), and xylocaine jelly and hypaque contrast (group 3). Outcome measures were pain scores, visualization of the apex (indicated by urethrogram tip), and frequency of corrections necessary on the basis of verification port films. Group 3 patients had the lowest mean pain score and required fewer lateral setup corrections at the time of portal imaging on the first day of treatment. A comparison of radiographs also revealed that group 2 and 3 patients (hypaque contrast) had better delineation of the prostatic anatomy than group 1 patients (air contrast). We found that of the 3 techniques tested, urethrography utilizing xylocaine jelly and hypaque was associated with the least amount of pain, least amount of corrective shifts, and best quality in defining the prostatic anatomy.