Pediatric penile reconstruction using autologous split-thickness skin graft.

This video provides a case report of penis entrapment secondary to excessive skin removal during circumcision. It highlights the technical aspects of pediatric penile reconstruction using autologous split-thickness skin graft (STSG). Key points include: 1. Infection prevention is paramount and antibiotic prophylaxis is routine. 2. The usual harvest site for the STSG is the lateral thigh because of its source of glabrous skin and convenient proximity to the penis. The lateral thigh is also outside of the diapered area, which helps lessen postoperative pain and infectious risks. 3. A dermatome is used to harvest the STSG. Skin thickness for penis coverage at this age is usually 10-12/1000 of an inch. 4. Direct contact of the graft and wound bed is essential for graft uptake. Hemostasis of the wound bed is critical to prevent hematoma formation. Elimination of redundant tissue is also important to ensure maximal contact between the graft and underlying wound bed. 5. A pressure dressing or bolster is used to prevent shear, and provide contact between the graft and wound bed for at least the first 5 days. 6. A semi-occlusive dressing, Tegaderm, was used on the donor site and it is believed that it provides a moist environment conducive for epithelial and dermal healing. 7. Lymphedema can result if excess distal penile skin is not excised. It is prudent to limit the amount of mucosal collar or consider direct anastomosis to the glans.

Carbon dioxide laser for detrusor tunnel creation in robot-assisted laparoscopic extravesical ureteral reimplant.

OBJECTIVE: Demonstrate and report initial results using a carbon dioxide (CO2) laser for detrusor tunnel creation in robot-assisted laparoscopic extravesical ureteral reimplant (RALUR). METHODS: Retrospective chart review was performed for cases of RALUR from 2011 to 2014. Patients undergoing complex reconstruction (ureteral tailoring, dismembered reimplant, concomitant ureteroureterostomy), and those who had incomplete follow-up were excluded. Variables, including use of the CO2 laser, were collected and correlated with outcomes. RESULTS: 23 patients representing 40 ureteral units were included for analysis. A CO2 laser was used in 9/23 (39%) patients and 16/40 (40%) ureteral units. Intraoperative mucosotomy was reported in 3/14 (21%) patients for the electrocautery group and 1/9 (11%) patients for the CO2 laser group. Resolution of VUR was observed in 11/14 (79%), and 9/9 (100%) of patients for the electrocautery group and the CO2 laser group, respectively. Two complications were identified in the electrocautery group of patients: ileus (Clavien 2), and transient bilateral ureteral obstruction requiring placement of ureteral stents (Clavien 3B). There were no complications in the CO2 laser group. CONCLUSIONS: Creation of the detrusor tunnel with a CO2 laser is safe and effective, and is associated with a lower rate of failure and complication in this cohort.

Single-file diffusion in periodic energy landscapes: the role of hydrodynamic interactions.

We report on the dynamical properties of interacting colloids confined to one dimension and subjected to external periodic energy landscapes. We particularly focus on the influence of hydrodynamic interactions on the mean-square displacement. Using Brownian dynamics simulations, we study colloidal systems with two types of repulsive interparticle interactions, namely, Yukawa and superparamagnetic potentials. We find that in the homogeneous case, hydrodynamic interactions lead to an enhancement of the particle mobility and the mean-square displacement at long times scales as t(α), with α=1/2+ε and ε being a small correction. This correction, however, becomes much more important in the presence of an external field, which breaks the homogeneity of the particle distribution along the line and, therefore, promotes a richer dynamical scenario due to the hydrodynamical coupling among particles. We provide here the complete dynamical scenario in terms of the external potential parameters: amplitude and commensurability.

Ribosomal DNA internal transcribed spacers to estimate the proportion of Pisolithus tinctorius and Eucalyptus RNAs in ectomycorrhiza.

Ectomycorrhiza is a complex association of several types of plant and fungal cells. Differentiation of symbiotic structures is correlated with large changes in mRNA synthesis, leading to novel protein patterns. Quantification of up- and down-regulated specific transcripts is complicated by the intermingling of root and hyphal components. Determination of steady-state levels of symbiosis-regulated mRNA requires a normalization to the housekeeping RNA content of each partner. In this study, the usefulness of the internal transcribed spacer (ITS)-5.8S ribosomal DNAs (rDNAs) as molecular markers of the root colonization by fungal mycelium was assayed. The rDNA ITSs of Pisolithus tinctorius and Eucalyptus globulus were cloned by PCR amplification, and their sequences were determined. They contained the 5.8S rDNAs, and these two probes did not cross-hybridize. Steady-state levels of the ITS-5.8S rRNAs in the vegetative mycelium, in the noninfected root, and in ectomycorrhizas of E. globulus-P. tinctorius 441 were estimated at different stages of development. Colonization of roots by the mycelium provoked a large decrease in the proportion of root rRNAs. At the end of mycorrhiza formation, about 80% of the ectomycorrhizal RNA belonged to the mycobiont. The ITS-5.8S can be used as a specific probe for the estimation of fungal or plant rRNA in the symbiotic tissues and to determine whether an mRNA is down- or up-regulated in ectomycorrhiza.

Eucalypt alpha-tubulin: cDNA cloning and increased level of transcripts in ectomycorrhizal root system.

Because symbionts are experiencing major morphological changes during ectomycorrhiza development, the expression of genes encoding cytoskeletal proteins is likely altered. To test this contention, we have cloned and characterized in a alpha-tubulin cDNA (EgTubA1) from Eucalyptus globulus. A poorly-aggressive isolate (No. 270) of the ectomycorrhizal basidiomycete Pisolithus tinctorius caused no changes in root transcript levels of EgTubA1, whereas a drastic up-regulation in its expression was observed between 3 to 4 days after contact with the aggressive isolate 441. This enhanced alpha-tubulin expression coincided with the increase lateral root formation induced by fungal colonisation. The changes in alpha-tubulin expression support a role for cytoskeleton components in ectomycorrhiza development.