The distribution of the prostaglandin E receptor type 2 (EP2) in the detrusor of the guinea pig.

OBJECTIVE: To explore the distribution of prostaglandin E receptor type 2 (EP2) in the bladder muscle layers and its spatial relationship to cyclo-oxygenase type 1 (COX I). MATERIALS AND METHODS: Twelve male guinea pigs were killed by cervical dislocation, the bladders removed and fixed in 4% paraformaldehyde in PBS. Frozen sections of 10 µm were cut and stained with antibodies to EP2, COX I and vimentin. RESULTS: EP2 receptor immunoreactivity is located on the smooth muscle cells as well as on vimentin positive surface muscle and intramuscular interstitial cells. EP2 expression on interstitial cells is highly localized. Discrete regions of intense staining were observed on the interstitial cell processes. COX I is expressed in the muscle interstitial cells and was found to be located on discrete regions of the cell and cell processes. Double staining with EP2 and COX I suggests that the regions of a cell expressing EP2 are different from those expressing COX I. CONCLUSIONS: The presence of COX I, prostaglandin E receptor type 2 (EP2) immune-reactivity in the network of interstitial cells suggests a role of this network in the propagation of signals. Due to a cAMP coupling of the EP2 receptor in many other tissues and a lower dissociation constant of EP2, it is suggested that a rise in PG levels may gradually push the balance from a relaxant EP2 effect towards a contractile effect. Hence, PG could have a modulatory role on the non-voiding bladder contractions by changing the threshold level for excitability of the interstitial cell network.

Nonvoiding activity of the guinea pig bladder.

PURPOSE: Detrusor nonvoiding contractions occur in up to 70% of healthy individuals. These contractions increase in those with pathological detrusor function and may be associated with afferent activity. We examined nonvoiding contractions in the urethane anesthetized guinea pig bladder and studied the effect of filling rate and intravesical volume. MATERIALS AND METHODS: A total of 14 guinea pigs were anesthetized and underwent bladder catheterization at the dome. In 6 guinea pigs bladder infusion was continuous and 2 physiological filling rates were used, including 25 (0.75 HD) and 50 µl per minute (1.5 HD). In another 8 guinea pigs isovolumetric cystometry was done by filling the bladder incrementally and recording at low, medium and high intravesical volume. RESULTS: Nonvoiding contractions were apparent in all animals. Contractions increased in frequency and amplitude as the bladder filled. Different phases were identified. Immediately after a void no nonvoiding contractions were observed, followed by continuous activity, first with small contractions, and later with small and large contractions. Small nonvoiding contractions showed a phasic pattern in frequency while the frequency of large nonvoiding contractions slowly increased or remained stable. The frequency and amplitude of nonvoiding contractions were higher at a faster filling rate and a higher intravesical volume. CONCLUSIONS: Nonvoiding contractions are present in the anesthetized guinea pig. Under normal physiological conditions they increase in amplitude and frequency with the increase in the filling rate and in intravesical volume. Small and large nonvoiding contractions differ in frequency pattern and occur at different bladder filling periods. This may illustrate different afferents functioning during bladder filling, which could be important for understanding bladder pathology.

Scrotal approach to both palpable and impalpable undescended testes: should it become our first choice?

OBJECTIVES: To determine the advantages of scrotal incision in the treatment of undescended testis. Undescended testis is a common pediatric condition and is conventionally managed surgically by orchidopexy. A single scrotal incision orchidopexy has become accepted as a valid approach for patients with palpable undescended testicles. Because this approach also allows easy detection of atrophic testes or testicular remnants, it recently has also emerged as an alternative initial surgical approach to impalpable undescended testicles. METHODS: All orchidopexies performed between 2004 and 2008 at our university hospital were prospectively included in this study. A total of 194 scrotal orchidopexies were performed in 154 patients (mean age, 71 months; range, 4-229 months). In all cases a scrotal approach was chosen irrespective of the initial position or presence of an open processus vaginalis. Testicular position was examined at follow-up after a mean period of 10 months (3-22 months). RESULTS: Overall, 36 of the 46 impalpable testicles (78%) could be diagnosed and treated accordingly, using only a scrotal incision. Conversion to laparoscopy was needed in 4 cases. A limited number of postoperative complications were seen. In all cases, the testes were palpable and remained in the scrotum on follow-up. CONCLUSIONS: Initial single scrotal incision can be recommended for orchidopexy, even in the more difficult cases of impalpable undescended testes. Advantages seem to include shorter operative time, a cosmetically appealing single incision, and possibly less pain. The scrotal incision technique significantly reduces the need for laparoscopy in impalpable testes. Surprisingly, it even allows successful orchidopexy of abdominal testes, provided an open processus is present.

Decongestant effects of nasal xylometazoline and mometasone furoate in persistent allergic rhinitis.

Thirty-six persistent allergic rhinitis (PAR) sufferers were studied, to both compare and correlate 15 minute response to nasal xylometazoline (XYLO) with 28 day response to nasal mometasone furoate (MF). 0.1% XYLO (1 spray each nostril) response was measured on two occasions, then a randomised double blind cross-over comparison of MF (200 mcg daily) to placebo conducted. Outcomes were peak nasal inspiratoly flow (PNIF), nasal forced inspiratory volume in one second (nFIV1) and nasal blockage score (NBS) improvements. Thirty-one participants completed per protocol. Within subject standard deviation for percentage improvement to XYLO was 26.0 for PNIF and 25.2 for nFIV1. Median % improvement (95%CI) in PNIF for XYLO vs. MF was 20.0 (11.4 to 31.0) vs. 9.6 (3.2 to 15.8) and in nFIV1 was 17.8 (10.0 to 28.1) vs. 3.3 (-4.3 to 19.1). XYLO effects were greater than MF (p<0.05) for PNIF, nFIV1 and NBS. There was no significant correlation of MF to XYLO improvements in PNIF, nFIV1 or NBS. In conclusion, acute reversibility to XYLO showed poor repeatability and XYLO reversibility is not predictive of decongestant response to nasal corticosteroid. XYLO was a stronger decongestant than MF but rhinitis medicamentosa still precludes any preference for long term XYLO therapy at this time.