Endoscopic Treatment of Vesicoureteral Reflux with Autologous Chondrocytes: Postoperative Sonographic Features

Transport of Live Cells Under Sterile Conditions Using a Chemotactic Droplet

1-Decanol droplets, formed in an aqueous medium containing decanoate at high pH, become chemotactic when a chemical gradient is placed in the external aqueous environment. We investigated if such droplets can be used as transporters for living cells. We developed a partially hydrophobic alginate capsule as a protective unit that can be precisely placed in a droplet and transported along chemical gradients. Once the droplets with cargo reached a defined final destination, the association of the alginate capsule and decanol droplet was disrupted and cargo deposited. Both Escherichia coli and Bacillus subtilis cells survived and proliferated after transport even though transport occurred under harsh and sterile conditions.

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.

Endoscopic treatment of vesicoureteral reflux using dextranomer/hyaluronic acid copolymer in children: results of postoperative follow-up with real-time 3D sonography

OBJECTIVES

We evaluated whether real-time 3D ultrasound (4D-US) together with clinical evaluation is an alternative to voiding cystourethrography (VCUG) after endoscopic treatment of vesicoureteral reflux (VUR) in children at postoperative follow-up.

MATERIAL AND METHODS

We reviewed 178 children who underwent endoscopic therapy with dextranomer/hyaluronic acid copolymer in grade II or III VUR between 2002 and 2005. 4D-US was performed in all patients 1 day and 3, 9 and 18 months after endoscopic therapy. Only children with postoperative urinary tract infections (UTIs) and/or nonorthotopic position of the bulking agent were referred for VCUG.

RESULTS

In 93% of the ureteral units, the depot could be detected in the orthotopic position after 3, 9 and 18 months. None of these children developed UTIs in the postoperative follow-up. Twelve children demonstrated a shifting of the depot, indicating a possible therapy failure. Eight of these 12 patients (66.7%) presented a positive VCUG, and 50% of them sustained UTIs.

CONCLUSIONS

4D-US seems to be a sufficient protocol in the follow-up of children after endoscopic treatment of low-grade VUR. VCUG should be performed in cases of a shifted position of the depot; invasive investigations are unnecessary in asymptomatic children with orthotopic bulk.

Cavernous nerve regeneration using acellular nerve grafts

INTRODUCTION

The restoration of erectile function following complete transection of nerve tissue during surgery remains challenging. Recently, graft procedures using sural nerve grafts during radical prostatectomy have had favorable outcomes, and this has rekindled interest in the applications of neural repair in a urologic setting. Although nerve repair using autologous donor graft is the gold standard of treatment currently, donor nerve availability and the associated donor site morbidity remain a problem. In this study, we investigated whether an "off-the-shelf" acellular nerve graft would serve as a viable substitute. We examined the capacity of acellular nerve scaffolds to facilitate the regeneration of cavernous nerve in a rodent model.

MATERIALS AND METHODS

Acellular nerve matrices, processed from donor rat corporal nerves, were interposed across nerve gaps. A total of 80 adult male Sprague-Dawley rats were divided into four groups. A 0.5-cm segment of cavernosal nerve was excised bilaterally in three of the four groups. In the first group, acellular nerve segments were inserted bilaterally at the defect site. The second group underwent autologous genitofemoral nerve grafts at the same site, and the third group had no repair. The fourth group underwent a sham procedure. Serial cavernosal nerve function assessment was performed using electromyography (EMG) at 1 and 3 months following initial surgery. Histological and immunocytochemical analyses were performed to identify the extent of nerve regeneration.

RESULTS

Animals implanted with acellular nerve grafts demonstrated a significant recovery in erectile function when compared with the group that received no repair, both at 1 and 3 months. EMG of the acellular nerve grafts demonstrated adequate intracavernosal pressures by 3 months (87.6% of the normal non-injured nerves). Histologically, the retrieved regenerated nerve grafts demonstrated the presence of host cell infiltration within the nerve sheaths. Immunohistochemically, antibodies specific to axons and Schwann cells demonstrated an increase in nerve regeneration across the grafts over time. No organized nerve regeneration was observed when the cavernous nerve was not repaired.

CONCLUSION

These findings show that the use of nerve guidance channel systems allow for accelerated and precise cavernosal nerve regeneration. Acellular nerve grafts represent a viable alternative to fresh autologous grafts in a rodent model of erectile dysfunction.

Successful myoblast transplantation in rat tongue reconstruction

BACKGROUND

Controversy exists regarding the success of myoblast transplantation. The purpose of this study was to determine the survival of transplanted myoblasts in a rat tongue reconstruction model by using fluorescently labeled myoblasts and surgical stains to mark the location of the pocket into which transplanted cells were delivered. We evaluated tongue histology after myoblast transplantation under the hypothesis that myoblast transplantation will promote muscle regeneration and result in minimal scar tissue formation.

METHODS

Sterile solutions of 1:10 India ink, 1% methylene blue, and 1% crystal violet were applied to the inner lining of a left-sided mucosa-sparing hemiglossectomy pocket. After air-drying, the hemiglossectomy defect was filled with collagen gel and closed. The tongues were evaluated histologically at 6 weeks. Next, myoblasts were cultured and labeled with three commercially available fluorescent dyes, 5-chloromethyl-fluorescein diacetate (CMFDA), chloromethylbenzamido (CM-DiI), and fluorescently labeled microspheres (FLMs), to determine which would optimally label myoblasts in a tongue reconstruction model. Next, Lewis rats underwent left hemiglossectomy, and the created pockets were coated with 1:10 India ink. Control animals received collagen gel alone, whereas experimental animals received labeled myoblast/collagen constructs into the tongue defect. Tongues were harvested at intervals to determine the presence of labeled fluorescent cells, the relative numbers of viable myoblasts, and the degree of scarring.

RESULTS

India ink coating of the hemiglossectomy pocket caused minimal inflammation and lasted longer than the other tested dyes. CMFDA and FLMs both successfully label myoblasts for transplantation. In vivo, donor cells were observed in all specimens at week 0 with increasing numbers of cells and muscle formation, determined by desmin immunofluorescence, after 6 weeks. There was less scar tissue contracture in the experimental group and a significant increase in the amount of desmin-stained muscle in the surgical defect.

CONCLUSIONS

India ink is an appropriate vehicle for intra-operative marking of a hemiglossectomy cavity. The introduction of myoblast/collagen constructs into the rat hemiglossectomy defect increases the amount of regenerated muscle, results in less scar contracture, and may increase meaningful tongue function.

Sphincter incontinence: is regenerative medicine the best alternative to restore urinary or anal sphincter function?

Incontinence is a major public health concern in aging societies. It is caused by age-dependent spontaneous apoptosis of muscle cells in the urinary and fecal sphincters, and is aggravated in women due to birth trauma. Compared to other currently employed invasive surgical management techniques associated with morbidity and recurrence, replacement or regeneration of dysfunctional sphincter through stem cell therapy and tissue engineering techniques hold great promise. This review focuses on the pathophysiological analysis of urinary incontinence and the possible application of muscle-derived-stem cells, satellite cells, chondrocytes and adipose-derived-stem cells in restoring sphincter functions.

[Ultrasound role in assessment of vesicoureteral reflux endoscopic treatment results]

INTRODUCTION

Since the beginning of the application of the RVU treatment, the use of the ultrasound was used taking into account two main indications/symptoms: a) identification of the complications; b) assessment of the result (visualization of the implanted material and the presence of the "uretheral jet" by means or through/of ecodoppler-color).

OBJECTIVE

To determine the value of the ultrasound in the assessment of the result of the endoscopic treatment of the RVU and in the detection of its complications.

MATERIAL AND METHOD

From 2001-2002 we have carried out the endoscopic treatment to an overall of 261 ureteral units of all degree and etiology. 246 were assessed post-operation with an ultrasound per month and all of them were evaluated with a cistography after 3 months. In a random sample of 92 units, the result of the isotopic cistography has been compared with the visualization of the implanted material in the bladder; and in a random sample of 56 units, the result of the isotopic cistography has been compared with the presence of ureteral jet in the study with ecodoppler-color after moisturizing of the patient. In order to do, we have done two corresponding comparative charts 2 x 2 and we have calculated the Sensibility and Specificity of the tests, as well as their predictive positive and negative values, the degree of similarity of both tests with the Kappa index, and the degree of statistical relevance with Chi squared.

RESULTS

The ultrasound did not show significant changes if compared to previous studies in 213 units (86,58 %) although in 5 patients an ectasia has been identified as attributed to the treatment. 3 of this patients have developed renoureteral pain, and in 2 pain has spontaneously disappeared as shown in later tests. The S and the E of the presence of implanted material is 94% and 10%respectively and its VPP and VPN of 80% and 10% and estadistical. The S and E of the jet visualization is 82% and 30%, with a VPP of 84% and a VPN of 27%, a level of statistical relevance of 0.836 and a degree of correlation of 0.121.

CONCLUSIONS

Ultrasound is not a useful technique in the assessment of the result of the endoscopic treatment of the RVU. The role it plays in the assessment of complications is a small one and its use is only indicated to confirm the suspicion of ectasia in those patients that present renoureteral pain.

The Chondrocyte: Biology and Clinical Application

Chondrocyte is a unique cell type in articular cartilage tissue and is essential for cartilage formation and functionality. It arises from mesenchymal stem cells (MSCs) and is regulated by a series of cytokine and transcription factor interactions, including the transforming growth factor-beta super family, fibroblast growth factors, and insulin-like growth factor-1. To understand the biomechanisms of the chondrocyte differentiation process, various cellular model systems have been employed, such as primary chondrocyte culture, clonal normal cell lines (HCS-2/8, Ch-1, ATDC5, CFK-2, and RCJ3.1C5.18), and transformed clonal cell lines (T/C-28a2, T/C-28a4, C-28/I2, tsT/AC62, and HPV-16 E6/E7). Additionally, cell culture methods, including conventional monolayer culture, three-dimensional scaffold culture, bioreactor culture, pellet culture, and organ culture, have been established to create stable environments for the expansion, phenotypic maintenance, and subsequent biological study of chondrocytes for clinical application. Knowledge gained through these study systems has allowed for the use of chondrocytes in orthopedics for the treatment of cartilage injury and epiphyseal growth plate defects using tissue-engineering approaches. Furthermore, the potential of chondrocyte implantation for facial reconstruction, the treatment of long segmental tracheal defects, and urinary incontinence and vesicoureteral reflux are being investigated. This review summarizes the present study of chondrocyte biology and the potential uses of this cell in orthopedics and other disciplines.