Can autologous myoblasts be used as a potential bulking agent?

Vesicoureteral reflux: From prophylaxis to surgery

Vesicoureteral reflux (VUR) is one of the most common pathologies encountered in pediatric urology. Better understanding of the evolution of VUR and new endoscopic surgical techniques in the last decades have led to major changes in the management of this pathology. However, the treatment algorithm remains complex and is composed of a wide variety of options, from active surveillance to surgical treatment. Herein, we propose to review treatment options for VUR in order to help clinicians make the right treatment decision for the right patient.

Transplantation of mature adipocyte-derived dedifferentiated fat cells for the treatment of vesicoureteral reflux in a rat model

PURPOSE

Autologous cells potentially provide an ideal injectable substance for management in vesicoureteral reflux (VUR). The aim of this study is to examine the effects of mature adipocyte-derived dedifferentiated fat (DFAT) cell transplantation on VUR in a rat bladder pressurization-induced VUR model.

METHODS

To create VUR, Sprague-Dawley rats underwent urethral clamping and placement of cystostomy followed by intravesical pressurization. Rat DFAT cells (1 × 10⁶ cells, DFAT group, n = 5) or saline (control group, n = 5) was then injected into the bilateral vesicoureteral junctions. Two weeks later, VUR grade was evaluated on cystography. The number of apoptotic cells in the renal pelvic urothelium, the ureteral inner/outer diameter ratio and the area of connective tissue in the posterior bladder wall were measured.

RESULTS

The reflux grade in the DFAT group was significantly lower than that in the control group. The number of apoptotic cells in the renal pelvic urothelium, ureteral inner/outer diameter ratio and connective tissue area in DFAT group were significantly lower in comparison with the control group.

CONCLUSIONS

DFAT cell transplantation improved VUR and exerted nephroprotective effects in a rat VUR model.

Functional outcome after anal sphincter injury and treatment with mesenchymal stem cells

This research demonstrates the regenerative effects of mesenchymal stem cells (MSCs) on the injured anal sphincter by comparing anal sphincter pressures following intramuscular and serial intravascular MSC infusion in a rat model of anal sphincter injury. Fifty rats were divided into injury (n = 35) and no injury (NI; n = 15) groups. Each group was further divided into i.m., serial i.v., or no-treatment (n = 5) groups and followed for 5 weeks. The injury consisted of an excision of 25% of the anal sphincter complex. Twenty-four hours after injury, 5 × 10(5) green fluorescent protein-labeled MSCs in 0.2 ml of phosphate-buffered saline (PBS) or PBS alone (sham) were injected into the anal sphincter for i.m. treatment; i.v. and sham i.v. treatments were delivered daily for 6 consecutive days via the tail vein. Anal pressures were recorded before injury and 10 days and 5 weeks after treatment. Ten days after i.m. MSC treatment, resting and peak pressures were significantly increased compared with those in sham i.m. treatment (p < .001). When compared with the NI group, the injury groups had anal pressures that were not significantly different 5 weeks after i.m./i.v. treatment. Both resting and peak pressures were also significantly increased after i.m./i.v. MSC treatment compared with treatment with PBS (p < .001), suggesting recovery. Statistical analysis was done using paired t test with Bonferroni correction. Marked decrease in fibrosis and scar tissue was seen in both MSC-treated groups. Both i.m. and i.v. MSC treatment after injury caused an increase in anal pressures sustained at 5 weeks, although fewer cells were injected i.m. The MSC-treated groups showed less scarring than the PBS-treated groups, with the i.v. infusion group showing the least scarring.

Autologous fibroblast transplantation at the vesico-ureteral junction as potential reconstructive cell replacement in an animal model

PURPOSE

To evaluate the cellular survival of donor fibroblasts after transplantation at the vesico-ureteral junction (VUJ) and to analyse their potential for reconstructive cell replacement in an animal model as autologous fibroblasts have been used as soft tissue augmentation material for scared and damaged tissue.

METHODS

Muscles biopsies were procured from the lower limb muscles of 4 pigs; cytoplasm of fibroblasts was labelled with nano-sized iron oxide particles. Six weeks after taking of the muscle biopsies, fibroblast transplantation was performed, 3 × 10(6) cells suspended in transplantation medium (in 1-ml syringes) were injected at the VUJ using the modified STING technique. Animals were killed 8 weeks later; seeded fibroblasts were identified using prussian blue staining protocol; histological evaluation and morphological analysis were performed by light microscopy (Mayer's haematoxylin-eosin staining); and bladders were scanned by MRI for visualization and localization of the iron-labelled donor cells.

RESULTS

Donor fibroblast cell colonization and cellular viability at the VUJ was demonstrated by MRI and histochemically indicating cellular uptake of iron particles at the VUJ. It was also evident that transplanted fibroblasts integrate into the extracellular matrix of the distal ureter augmenting ureteral host tissue.

CONCLUSIONS

Labelled implanted autologous fibroblasts were visualized by staining procedure as well as MRI scan demonstrating persistence at the VUJ, suggesting that in vitro expanded fibroblasts survived in vivo after transplantation.

Urethral bulking agents: techniques and outcomes

Stress urinary incontinence is a common health problem affecting women and interfering with their quality of life. The use of bulking agents for urethral augmentation seems to be a beneficial way of restoring continence in these patients while avoiding the risk of surgical intervention. Many agents are available for injection, but the ideal choice should be durable, nonmigratory, and hypoallergenic, while evoking healing with minimal scarring. We reviewed the literature to provide an update on the best techniques of bulking agent injection, to describe the different available injectable agents, and to give their outcome and possible complications.