Megaprepuce: presentation of a modified surgical technique with excellent cosmetic and functional results.

OBJECTIVE: Congenital megaprepuce is a malformation consisting of a great redundancy of the inner preputial skin over a penis with normal shaft and glans and is combined with a severe phimosis. Patients suffer from difficulties in voiding because the urine is trapped in the large dome-shaped megaprepuce. We describe a modification of the surgical technique of reconstructing a megaprepuce initially presented by Leao et al. PATIENTS AND METHODS: We retrospectively reviewed 7 patients aged 6-53 months (mean age 17 months, 6 were younger than 18 months) who underwent congenital megaprepuce repair between 02/2014 and 05/2018 in our institution. All these otherwise healthy children suffering from difficulties in voiding and reporting genital ballooning during micturition and urinary retention were referred to our hospital. In all cases, parents needed to express the trapped urine. Four of these patients additionally showed a glanular hypospadias, another one a distal penile hypospadias. In addition to the repair of the megaprepuce, six patients needed correction of a penile curvature, five of whom needed correction of the chordee and one a corporoplasty (Schröder-Essed). The patient showing the distal penile hypospadias additionally underwent hypospadias repair. During the follow-up, we evaluated the cosmetic result and complications such as secondary concealed penis, difficulties in voiding, urinary retention, and urinary infections. RESULTS: Mean follow-up was 18 months. All patients following surgery showed normal voiding without urinary retention or urinary infections and good cosmetic results resembling a circumcised penis in appearance without reconcealment. No intraoperative complications occurred. One patient had a scrotal hematoma postoperatively. Mild transient edema of the penis was seen in all patients, which disappeared spontaneously within one week after surgery. CONCLUSION: Our surgical approach is a safe and relatively simple procedure with a low rate of complications, good cosmetic results, and functional outcome. Whether the hypospadias associated with ventral curvature was a coincidence or part of the disease pattern remains unclear but will probably be the object of further investigations.

Mechanosensitive ion channels in putative aortic baroreceptor neurons.

Cell-attached patch-clamp experiments were performed on dissociated neurons from nodose ganglia of adult rats. Putative aortic baroreceptor neurons were identified by labeling nerve endings in the adventitia of the aortic arch with the carbocyanine dye DiI. Whereas previous experiments demonstrated the presence of mechanosensitive (MS) whole cell currents, these experiments studied single MS ion channels and examined the influence of culture conditions on their expression. Single MS channels were activated by applying negative pressure through the recording pipette. Channel openings became more frequent as the negative pressure was increased, with open probability increasing significantly above 30 mmHg. MS channels had a slope conductance of 114 pS and a reversal potential of approximately 0 mV, consistent with a nonspecific cation conductance. Channels were not affected by antagonists of voltage-gated conductances but were blocked by 20 microM gadolinium, a known blocker of MS ion channels. When nodose neurons were cocultured with aortic endothelial cells, but not aortic smooth muscle cells, the percentage of patches exhibiting MS ion channels increased significantly, suggesting that aortic endothelial cells secrete a diffusible factor that increases channel expression.

Sodium channels in cultured neuroblastoma cells grown in high glucose or L-fucose.

Patch clamp techniques were used to record whole cell and single channel Na+ currents from NB41A3 neuroblastoma cells grown in culture. Cells were grown for two weeks in control medium or medium supplemented with 30 mM D-glucose of 30 mM L-fucose. Cells exposed to glucose or L-fucose had smaller whole cell Na+ currents than cells grown in unsupplemented medium, consistent with earlier studies (Yorek, Stefani & Wachtel, 1994). Whole cell macroscopic currents showed no change in activation or inactivation kinetics. Single channel current properties and opening probability were also unchanged. The number of [3H]saxitoxin binding sites, and therefore the total number of Na+ channels, was not reduced in cells grown in glucose or L-fucose (Yorek et al., 1994). Therefore, we conclude that some of the channels must have been rendered nonfunctional by the conditioning media. The finding that single channel properties are not altered suggests that channels become nonfunctional in an all-or-none manner.