Stephane Bolduc | Université Laval (original) (raw)
Papers by Stephane Bolduc
Purpose of the review: Vesicoureteral reflux (VUR) is a common pathology encountered in pediatric... more Purpose of the review: Vesicoureteral reflux (VUR) is a common pathology encountered in pediatric urology. If left untreated, this condition can lead to infectious complications, hypertension and loss of renal function by scars. There is a trend for minimally invasive procedures to minimise treatment-related complications. Endoscopic subureteral injection of bulking agent in the treatment of VUR is an example of minimally invasive options. Several bulking agents have been studied and the perfect agent has not yet been discovered. Polyacrylamide hydrogel is a relatively new agent used to treat VUR and its use will be reviewed. Recent findings: Three modern studies from a Canadian group have evaluated the use of polyacrylamide hydrogel for endoscopic injection to treat VUR. The first study reported a cure rate of 81.2% without major complication. In the second study, injection of polyacrylamide hydrogel was compared to dextranomer hyaluronic acid and no significant difference was obse...
Repair or replacement of the male anterior urethra remains a challenge in 2019 especially in the ... more Repair or replacement of the male anterior urethra remains a challenge in 2019 especially in the case of patients presenting severe defects due to the paucity of tissues available for reconstructive surgeries. Nowadays, surgeons mainly use buccal mucosa, which can come with complications not only at the donor site but also at the graft site. This option is sometimes invasive in the case of long defects when large pieces of tissue are needed. Tissue engineering is an emerging field in regenerative medicine and offers promising avenue. It allows reconstruction of large amount of autologous tissues using small biopsies. Several strategies of tissue engineering use biomaterials, which can cause adverse effects. A new option appears with the use of the "self-assembly" protocol to reconstruct tissues using only the cells of the patients and avoiding the use of biomaterials. Human-derived tubular structures were produced by this technique and present mechanical and functional properties compatible with grafting. Moreover, these tissues can be endothelialized to prevent graft ischemia. New challenges in tissue engineering is to differentiate the cells needed for the reconstruction from induced pluripotent stem cells derived from patient blood cells, and to avoid the use of animal serum for cell culture.
The literature on undescended testis (UDT) mainly concentrates on the increased risks of infertil... more The literature on undescended testis (UDT) mainly concentrates on the increased risks of infertility and development of germ cell tumours.1 Contemporary articles on pediatric testicular problems often poorly address this issue and sometimes neglect it. Not unexpectedly, there is not enough awareness among physicians or parents on this urological emergency; unfortunately in most cases, the diagnosis is deferred. Undescended testis also appears to be at higher risk for torsion compared to the normally descended testis; this issue is relatively poorly addressed. Gharbi and colleagues present an important review of this poorly appreciated topic,2 especially if the risk of torsion is 10 times higher for UDT.3 The risk of torsion in an UDT clearly needs to be made more evident to pediatric urologists and pediatricians, as approximately 2% of all males have UDT. The poor testis salvage rate in this series (40%) and in others (10%)4-5 reflects the late diagnosis resulting from lack of aware...
Bioengineering
Heat inactivation of bovine sera is routinely performed in cell culture laboratories. Nevertheles... more Heat inactivation of bovine sera is routinely performed in cell culture laboratories. Nevertheless, it remains debatable whether it is still necessary due to the improvement of the production process of bovine sera. Do the benefits balance the loss of many proteins, such as hormones and growth factors, that are very useful for cell culture? This is even truer in the case of tissue engineering, the processes of which is often very demanding. This balance is examined here, from nine populations of fibroblasts originating from three different organs, by comparing the capacity of adhesion and proliferation of cells, their metabolism, and the capacity to produce the stroma; their histological appearance, thickness, and mechanical properties were also evaluated. Overall, serum inactivation does not appear to provide a significant benefit.
Bioengineering
Tissue engineering is an emerging field of research that initially aimed to produce 3D tissues to... more Tissue engineering is an emerging field of research that initially aimed to produce 3D tissues to bypass the lack of adequate tissues for the repair or replacement of deficient organs. The basis of tissue engineering protocols is to create scaffolds, which can have a synthetic or natural origin, seeded or not with cells. At the same time, more and more studies have indicated the low clinic translation rate of research realised using standard cell culture conditions, i.e., cells on plastic surfaces or using animal models that are too different from humans. New models are needed to mimic the 3D organisation of tissue and the cells themselves and the interaction between cells and the extracellular matrix. In this regard, urology and gynaecology fields are of particular interest. The urethra and vagina can be sites suffering from many pathologies without currently adequate treatment options. Due to the specific organisation of the human urethral/bladder and vaginal epithelium, current r...
Composition and Function of the Extracellular Matrix in the Human Body
Tissue engineering results from the use of cells and scaffolds to reproduce structural and spatia... more Tissue engineering results from the use of cells and scaffolds to reproduce structural and spatial organization or function of a tissue. The Production of an ideal engineered tissue depends on its designed purpose. For clinical applications, the main concerns are biocompatibility and the generation of a tissue able to mimic most of its original biological functions. Moreover, the viability of an implanted tissue is associated with its stability to support vascular networks. This chapter summarizes the theory of the self-assembly approach for tissue engineering. Adjustments and modifications in stromal thickness and extracellular matrix composition for various self-assembled tissues are discussed. Methods developed to generate tissue closely mimicking the native morphology and structure, to incorporate capillary-like networks, and to reduce production time and costs are also reviewed. The self-assembly technique leads to the production of a stroma free of exogenous material and can be adapted to generate fastest, inexpensive, and near-tonative tissue bioengineering for medical and fundamental research applications.
Cancers
Bisphenol A (BPA) is an endocrine-disrupting molecule used in plastics. Through its release in fo... more Bisphenol A (BPA) is an endocrine-disrupting molecule used in plastics. Through its release in food and the environment, BPA can be found in humans and is mostly excreted in urine. The bladder is therefore continuously exposed to this compound. BPA can bind to multiple cell receptors involved in proliferation, migration and invasion pathways, and exposure to BPA is associated with cancer progression. Considering the physiological concentrations of BPA in urine, we tested the effect of nanomolar concentrations of BPA on the metabolism of bladder fibroblasts and cancer-associated fibroblasts (CAFs). Our results show that BPA led to a decreased metabolism in fibroblasts, which could alter the extracellular matrix. Furthermore, CAF induction triggered a metabolic switch, similar to the Warburg effect described in cancer cells. Additionally, we demonstrated that nanomolar concentrations of BPA could exacerbate this metabolic switch observed in CAFs via an increased glycolytic metabolism,...
World Journal of Stem Cells
Bioengineering
Animal testing has long been used in science to study complex biological phenomena that cannot be... more Animal testing has long been used in science to study complex biological phenomena that cannot be investigated using two-dimensional cell cultures in plastic dishes. With time, it appeared that more differences could exist between animal models and even more when translated to human patients. Innovative models became essential to develop more accurate knowledge. Tissue engineering provides some of those models, but it mostly relies on the use of prefabricated scaffolds on which cells are seeded. The self-assembly protocol has recently produced organ-specific human-derived three-dimensional models without the need for exogenous material. This strategy will help to achieve the 3R principles.
Scientific Reports
Tissue engineering is an emerging and promising concept to replace or cure failing organs, but it... more Tissue engineering is an emerging and promising concept to replace or cure failing organs, but its clinical translation currently encounters issues due to the inability to quickly produce inexpensive thick tissues, which are necessary for many applications. To circumvent this problem, we postulate that cells secrete the optimal cocktail required to promote angiogenesis when they are placed in physiological conditions where their oxygen supply is reduced. Thus, dermal fibroblasts were cultivated under hypoxia (2% O2) to condition their cell culture medium. The potential of this conditioned medium was tested for human umbilical vein endothelial cell proliferation and for their ability to form capillary-like networks into fibrin gels. The medium conditioned by dermal fibroblasts under hypoxic conditions (DF-Hx) induced a more significant proliferation of endothelial cells compared to medium conditioned by dermal fibroblasts under normoxic conditions (DF-Nx). In essence, doubling time f...
BioMed Research International
Cancer research has considerably progressed with the improvement of in vitro study models, helpin... more Cancer research has considerably progressed with the improvement of in vitro study models, helping to understand the key role of the tumor microenvironment in cancer development and progression. Over the last few years, complex 3D human cell culture systems have gained much popularity over in vivo models, as they accurately mimic the tumor microenvironment and allow high-throughput drug screening. Of particular interest, in vitrohuman 3D tissue constructs, produced by the self-assembly method of tissue engineering, have been successfully used to model the tumor microenvironment and now represent a very promising approach to further develop diverse cancer models. In this review, we describe the importance of the tumor microenvironment and present the existing in vitro cancer models generated through the self-assembly method of tissue engineering. Lastly, we highlight the relevance of this approach to mimic various and complex tumors, including basal cell carcinoma, cutaneous neurofib...
Materials
The use of ureteral stents to relieve urinary tract obstruction is still challenged by the proble... more The use of ureteral stents to relieve urinary tract obstruction is still challenged by the problems of infection, encrustation, and compression, leading to the need for early removal procedures. Biodegradable ureteral stents, commonly made of polymers, have been proposed to overcome these problems. Recently, absorbable metals have been considered as potential materials offering both biodegradation and strength. This work proposed zinc-based absorbable metals by firstly evaluating their cytocompatibility toward normal primary human urothelial cells using 2D and 3D assays. In the 2D assay, the cells were exposed to different concentrations of metal extracts (i.e., 10 mg/mL of Zn–1Mg and 8.75 mg/mL of Zn–0.5Al) for up to 3 days and found that their cytoskeletal networks were affected but were recovered at day 3, as observed by immunofluorescence. In the 3D ureteral wall tissue construct, the cells formed a multilayered urothelium, as found in native tissue, with the presence of tight j...
BioMed research international, 2018
Twenty years ago, Dr. François A. Auger, the founder of the Laboratory of Experimental Organogene... more Twenty years ago, Dr. François A. Auger, the founder of the Laboratory of Experimental Organogenesis (LOEX), introduced the self-assembly technique. This innovative technique relies on the ability of dermal fibroblasts to produce and assemble their own extracellular matrix, differing from all other tissue-engineering techniques that use preformed synthetic scaffolds. Nevertheless, the use of the self-assembly technique was limited for a long time due to its main drawbacks: time and cost. Recent scientific breakthroughs have addressed these limitations. New protocol modifications that aim at increasing the rate of extracellular matrix formation have been proposed to reduce the production costs and laboratory handling time of engineered tissues. Moreover, the introduction of vascularization strategies permits the formation of capillary-like networks within reconstructed tissues. These optimization strategies enable the large-scale production of inexpensive native-like substitutes usin...
Canadian Urological Association Journal
Canadian Urological Association Journal
Introduction: Dimercaptosuccinic acid (DMSA) scintigraphy is the gold standard in the evaluation ... more Introduction: Dimercaptosuccinic acid (DMSA) scintigraphy is the gold standard in the evaluation of renal parenchymal defects and is widely used in the pediatric population. As more recent ultrasound equipment was purchased at our tertiary pediatric centre, our objective was to evaluate if renal ultrasound (US) results are equivalent or sufficient when compared to DMSA scintigraphy in the assessment of renal anomalies.Methods: The charts of all 463 patients who underwent DMSA scintigraphy between January 2009 and May 2014 at our pediatric tertiary centre were reviewed. The objective was to look for correlation between US and DMSA scan results for renal scars/dysplasia. A hundred and sixty pediatric patients followed with US and DMSA scan for a total of 285 renal units remained for evaluation after exclusions. Timing of the exams, urinary tract infection (UTI), and indication for imaging were reviewed. Results with older (105 patients) and newer (55 patients) US equipment were compar...
Paediatrics & Child Health
Objectives: Adherence to antimuscarinics for the treatment of overactive bladder is known to be l... more Objectives: Adherence to antimuscarinics for the treatment of overactive bladder is known to be low in adults but there is scarce data on adherence in paediatric patients. Our objectives were to evaluate the adherence of children to antimuscarinics and to identify influencing factors. Methods: Children aged 5 to 18 years and treated with an antimuscarinic agent for at least 6 months were recruited at a routine visit and had to fill out a questionnaire. Their pharmacists were then contacted to inquire about prescription renewals since the beginning of treatment. The medication possession ratio was calculated and grouped by time blocks of 1, 3, 6 and 12 months. The pharmacists were contacted again 6 months after the recruitment visit. A medication possession ratio ≥ 80% was considered as good adherence. Results: Seventy-two patients were recruited with a mean age of 10.1 years. The self-reported adherence was 93%. Prior to the questionnaire, the medication possession ratio was ≥ 80% in 36%, 57%, 64% and 74% of cases in blocks of 1, 3, 6 and 12 months, respectively. After the questionnaire, the medication possession ratio improved to 53%, 65% and 71% for blocks of 1, 3 and 6 months, respectively. No influencing factors were identified. Conclusions: Measured adherence to antimuscarinics in children with overactive bladder is higher than in adults but significantly lower than the self-reported adherence. Good self-reported adherence must be questioned to avoid unnecessary dose escalation or change of medication. Strategies to increase medication adherence are required to improve treatment efficacy.
Journal of tissue engineering and regenerative medicine, Jan 3, 2017
Cells obtained from a patient's biopsy have to be expanded after extraction to produce autolo... more Cells obtained from a patient's biopsy have to be expanded after extraction to produce autologous tissues, but standard cell culture conditions often limit their growth or lifespan and could induce early and inadequate cell differentiation. Moreover, it has previously been reported that the air-liquid interface, that induces maturation of the urothelium, stimulated inadequate differentiation associated with aberrant keratin-14 expression. The aim of this study was to test the benefits of hypoxia during expansion of urothelial cells and maturation of the bladder epithelium in the context of tissue engineering. Bladder mucosa substitutes were reconstructed using the self-assembly method with urothelial cells (UCs) expanded in normoxia or hypoxia. Hypoxia improved UCs expansion until passage P7, whereas normoxic conditions limited the use of UCs to passage P4. Maturation of the urothelium was also compared in normoxic vs. hypoxic conditions. Using laminin V, p63, Ki-67, keratin-5 a...
Canadian Urological Association Journal, 2017
Vesicoureteral reflux (VUR) is one of the most common pathologies encountered in pediatric urolog... more 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.
Scientifica, 2016
Despite the emergence of serum-free media for cell culture, the use of serum to supplement the cu... more Despite the emergence of serum-free media for cell culture, the use of serum to supplement the culture media is still essential in order to produce engineered urologic tissues using the self-assembly approach, not only for the stromal compartment but also for the uroepithelium. Effects of sera on thickness of these two compartments were measured and quality of the epithelial differentiation was evaluated. For bladder mucosa substitute reconstruction, the use of postnatal sera failed to produce an adequate uroepithelium whereas the fetal sera supplementation did. Postnatal sera also provided thinner stromal compartments than the one obtained using fetal sera, no matter if the fibroblasts from healthy or psoriatic donors were used to reconstruct human skin substitutes.
Purpose of the review: Vesicoureteral reflux (VUR) is a common pathology encountered in pediatric... more Purpose of the review: Vesicoureteral reflux (VUR) is a common pathology encountered in pediatric urology. If left untreated, this condition can lead to infectious complications, hypertension and loss of renal function by scars. There is a trend for minimally invasive procedures to minimise treatment-related complications. Endoscopic subureteral injection of bulking agent in the treatment of VUR is an example of minimally invasive options. Several bulking agents have been studied and the perfect agent has not yet been discovered. Polyacrylamide hydrogel is a relatively new agent used to treat VUR and its use will be reviewed. Recent findings: Three modern studies from a Canadian group have evaluated the use of polyacrylamide hydrogel for endoscopic injection to treat VUR. The first study reported a cure rate of 81.2% without major complication. In the second study, injection of polyacrylamide hydrogel was compared to dextranomer hyaluronic acid and no significant difference was obse...
Repair or replacement of the male anterior urethra remains a challenge in 2019 especially in the ... more Repair or replacement of the male anterior urethra remains a challenge in 2019 especially in the case of patients presenting severe defects due to the paucity of tissues available for reconstructive surgeries. Nowadays, surgeons mainly use buccal mucosa, which can come with complications not only at the donor site but also at the graft site. This option is sometimes invasive in the case of long defects when large pieces of tissue are needed. Tissue engineering is an emerging field in regenerative medicine and offers promising avenue. It allows reconstruction of large amount of autologous tissues using small biopsies. Several strategies of tissue engineering use biomaterials, which can cause adverse effects. A new option appears with the use of the "self-assembly" protocol to reconstruct tissues using only the cells of the patients and avoiding the use of biomaterials. Human-derived tubular structures were produced by this technique and present mechanical and functional properties compatible with grafting. Moreover, these tissues can be endothelialized to prevent graft ischemia. New challenges in tissue engineering is to differentiate the cells needed for the reconstruction from induced pluripotent stem cells derived from patient blood cells, and to avoid the use of animal serum for cell culture.
The literature on undescended testis (UDT) mainly concentrates on the increased risks of infertil... more The literature on undescended testis (UDT) mainly concentrates on the increased risks of infertility and development of germ cell tumours.1 Contemporary articles on pediatric testicular problems often poorly address this issue and sometimes neglect it. Not unexpectedly, there is not enough awareness among physicians or parents on this urological emergency; unfortunately in most cases, the diagnosis is deferred. Undescended testis also appears to be at higher risk for torsion compared to the normally descended testis; this issue is relatively poorly addressed. Gharbi and colleagues present an important review of this poorly appreciated topic,2 especially if the risk of torsion is 10 times higher for UDT.3 The risk of torsion in an UDT clearly needs to be made more evident to pediatric urologists and pediatricians, as approximately 2% of all males have UDT. The poor testis salvage rate in this series (40%) and in others (10%)4-5 reflects the late diagnosis resulting from lack of aware...
Bioengineering
Heat inactivation of bovine sera is routinely performed in cell culture laboratories. Nevertheles... more Heat inactivation of bovine sera is routinely performed in cell culture laboratories. Nevertheless, it remains debatable whether it is still necessary due to the improvement of the production process of bovine sera. Do the benefits balance the loss of many proteins, such as hormones and growth factors, that are very useful for cell culture? This is even truer in the case of tissue engineering, the processes of which is often very demanding. This balance is examined here, from nine populations of fibroblasts originating from three different organs, by comparing the capacity of adhesion and proliferation of cells, their metabolism, and the capacity to produce the stroma; their histological appearance, thickness, and mechanical properties were also evaluated. Overall, serum inactivation does not appear to provide a significant benefit.
Bioengineering
Tissue engineering is an emerging field of research that initially aimed to produce 3D tissues to... more Tissue engineering is an emerging field of research that initially aimed to produce 3D tissues to bypass the lack of adequate tissues for the repair or replacement of deficient organs. The basis of tissue engineering protocols is to create scaffolds, which can have a synthetic or natural origin, seeded or not with cells. At the same time, more and more studies have indicated the low clinic translation rate of research realised using standard cell culture conditions, i.e., cells on plastic surfaces or using animal models that are too different from humans. New models are needed to mimic the 3D organisation of tissue and the cells themselves and the interaction between cells and the extracellular matrix. In this regard, urology and gynaecology fields are of particular interest. The urethra and vagina can be sites suffering from many pathologies without currently adequate treatment options. Due to the specific organisation of the human urethral/bladder and vaginal epithelium, current r...
Composition and Function of the Extracellular Matrix in the Human Body
Tissue engineering results from the use of cells and scaffolds to reproduce structural and spatia... more Tissue engineering results from the use of cells and scaffolds to reproduce structural and spatial organization or function of a tissue. The Production of an ideal engineered tissue depends on its designed purpose. For clinical applications, the main concerns are biocompatibility and the generation of a tissue able to mimic most of its original biological functions. Moreover, the viability of an implanted tissue is associated with its stability to support vascular networks. This chapter summarizes the theory of the self-assembly approach for tissue engineering. Adjustments and modifications in stromal thickness and extracellular matrix composition for various self-assembled tissues are discussed. Methods developed to generate tissue closely mimicking the native morphology and structure, to incorporate capillary-like networks, and to reduce production time and costs are also reviewed. The self-assembly technique leads to the production of a stroma free of exogenous material and can be adapted to generate fastest, inexpensive, and near-tonative tissue bioengineering for medical and fundamental research applications.
Cancers
Bisphenol A (BPA) is an endocrine-disrupting molecule used in plastics. Through its release in fo... more Bisphenol A (BPA) is an endocrine-disrupting molecule used in plastics. Through its release in food and the environment, BPA can be found in humans and is mostly excreted in urine. The bladder is therefore continuously exposed to this compound. BPA can bind to multiple cell receptors involved in proliferation, migration and invasion pathways, and exposure to BPA is associated with cancer progression. Considering the physiological concentrations of BPA in urine, we tested the effect of nanomolar concentrations of BPA on the metabolism of bladder fibroblasts and cancer-associated fibroblasts (CAFs). Our results show that BPA led to a decreased metabolism in fibroblasts, which could alter the extracellular matrix. Furthermore, CAF induction triggered a metabolic switch, similar to the Warburg effect described in cancer cells. Additionally, we demonstrated that nanomolar concentrations of BPA could exacerbate this metabolic switch observed in CAFs via an increased glycolytic metabolism,...
World Journal of Stem Cells
Bioengineering
Animal testing has long been used in science to study complex biological phenomena that cannot be... more Animal testing has long been used in science to study complex biological phenomena that cannot be investigated using two-dimensional cell cultures in plastic dishes. With time, it appeared that more differences could exist between animal models and even more when translated to human patients. Innovative models became essential to develop more accurate knowledge. Tissue engineering provides some of those models, but it mostly relies on the use of prefabricated scaffolds on which cells are seeded. The self-assembly protocol has recently produced organ-specific human-derived three-dimensional models without the need for exogenous material. This strategy will help to achieve the 3R principles.
Scientific Reports
Tissue engineering is an emerging and promising concept to replace or cure failing organs, but it... more Tissue engineering is an emerging and promising concept to replace or cure failing organs, but its clinical translation currently encounters issues due to the inability to quickly produce inexpensive thick tissues, which are necessary for many applications. To circumvent this problem, we postulate that cells secrete the optimal cocktail required to promote angiogenesis when they are placed in physiological conditions where their oxygen supply is reduced. Thus, dermal fibroblasts were cultivated under hypoxia (2% O2) to condition their cell culture medium. The potential of this conditioned medium was tested for human umbilical vein endothelial cell proliferation and for their ability to form capillary-like networks into fibrin gels. The medium conditioned by dermal fibroblasts under hypoxic conditions (DF-Hx) induced a more significant proliferation of endothelial cells compared to medium conditioned by dermal fibroblasts under normoxic conditions (DF-Nx). In essence, doubling time f...
BioMed Research International
Cancer research has considerably progressed with the improvement of in vitro study models, helpin... more Cancer research has considerably progressed with the improvement of in vitro study models, helping to understand the key role of the tumor microenvironment in cancer development and progression. Over the last few years, complex 3D human cell culture systems have gained much popularity over in vivo models, as they accurately mimic the tumor microenvironment and allow high-throughput drug screening. Of particular interest, in vitrohuman 3D tissue constructs, produced by the self-assembly method of tissue engineering, have been successfully used to model the tumor microenvironment and now represent a very promising approach to further develop diverse cancer models. In this review, we describe the importance of the tumor microenvironment and present the existing in vitro cancer models generated through the self-assembly method of tissue engineering. Lastly, we highlight the relevance of this approach to mimic various and complex tumors, including basal cell carcinoma, cutaneous neurofib...
Materials
The use of ureteral stents to relieve urinary tract obstruction is still challenged by the proble... more The use of ureteral stents to relieve urinary tract obstruction is still challenged by the problems of infection, encrustation, and compression, leading to the need for early removal procedures. Biodegradable ureteral stents, commonly made of polymers, have been proposed to overcome these problems. Recently, absorbable metals have been considered as potential materials offering both biodegradation and strength. This work proposed zinc-based absorbable metals by firstly evaluating their cytocompatibility toward normal primary human urothelial cells using 2D and 3D assays. In the 2D assay, the cells were exposed to different concentrations of metal extracts (i.e., 10 mg/mL of Zn–1Mg and 8.75 mg/mL of Zn–0.5Al) for up to 3 days and found that their cytoskeletal networks were affected but were recovered at day 3, as observed by immunofluorescence. In the 3D ureteral wall tissue construct, the cells formed a multilayered urothelium, as found in native tissue, with the presence of tight j...
BioMed research international, 2018
Twenty years ago, Dr. François A. Auger, the founder of the Laboratory of Experimental Organogene... more Twenty years ago, Dr. François A. Auger, the founder of the Laboratory of Experimental Organogenesis (LOEX), introduced the self-assembly technique. This innovative technique relies on the ability of dermal fibroblasts to produce and assemble their own extracellular matrix, differing from all other tissue-engineering techniques that use preformed synthetic scaffolds. Nevertheless, the use of the self-assembly technique was limited for a long time due to its main drawbacks: time and cost. Recent scientific breakthroughs have addressed these limitations. New protocol modifications that aim at increasing the rate of extracellular matrix formation have been proposed to reduce the production costs and laboratory handling time of engineered tissues. Moreover, the introduction of vascularization strategies permits the formation of capillary-like networks within reconstructed tissues. These optimization strategies enable the large-scale production of inexpensive native-like substitutes usin...
Canadian Urological Association Journal
Canadian Urological Association Journal
Introduction: Dimercaptosuccinic acid (DMSA) scintigraphy is the gold standard in the evaluation ... more Introduction: Dimercaptosuccinic acid (DMSA) scintigraphy is the gold standard in the evaluation of renal parenchymal defects and is widely used in the pediatric population. As more recent ultrasound equipment was purchased at our tertiary pediatric centre, our objective was to evaluate if renal ultrasound (US) results are equivalent or sufficient when compared to DMSA scintigraphy in the assessment of renal anomalies.Methods: The charts of all 463 patients who underwent DMSA scintigraphy between January 2009 and May 2014 at our pediatric tertiary centre were reviewed. The objective was to look for correlation between US and DMSA scan results for renal scars/dysplasia. A hundred and sixty pediatric patients followed with US and DMSA scan for a total of 285 renal units remained for evaluation after exclusions. Timing of the exams, urinary tract infection (UTI), and indication for imaging were reviewed. Results with older (105 patients) and newer (55 patients) US equipment were compar...
Paediatrics & Child Health
Objectives: Adherence to antimuscarinics for the treatment of overactive bladder is known to be l... more Objectives: Adherence to antimuscarinics for the treatment of overactive bladder is known to be low in adults but there is scarce data on adherence in paediatric patients. Our objectives were to evaluate the adherence of children to antimuscarinics and to identify influencing factors. Methods: Children aged 5 to 18 years and treated with an antimuscarinic agent for at least 6 months were recruited at a routine visit and had to fill out a questionnaire. Their pharmacists were then contacted to inquire about prescription renewals since the beginning of treatment. The medication possession ratio was calculated and grouped by time blocks of 1, 3, 6 and 12 months. The pharmacists were contacted again 6 months after the recruitment visit. A medication possession ratio ≥ 80% was considered as good adherence. Results: Seventy-two patients were recruited with a mean age of 10.1 years. The self-reported adherence was 93%. Prior to the questionnaire, the medication possession ratio was ≥ 80% in 36%, 57%, 64% and 74% of cases in blocks of 1, 3, 6 and 12 months, respectively. After the questionnaire, the medication possession ratio improved to 53%, 65% and 71% for blocks of 1, 3 and 6 months, respectively. No influencing factors were identified. Conclusions: Measured adherence to antimuscarinics in children with overactive bladder is higher than in adults but significantly lower than the self-reported adherence. Good self-reported adherence must be questioned to avoid unnecessary dose escalation or change of medication. Strategies to increase medication adherence are required to improve treatment efficacy.
Journal of tissue engineering and regenerative medicine, Jan 3, 2017
Cells obtained from a patient's biopsy have to be expanded after extraction to produce autolo... more Cells obtained from a patient's biopsy have to be expanded after extraction to produce autologous tissues, but standard cell culture conditions often limit their growth or lifespan and could induce early and inadequate cell differentiation. Moreover, it has previously been reported that the air-liquid interface, that induces maturation of the urothelium, stimulated inadequate differentiation associated with aberrant keratin-14 expression. The aim of this study was to test the benefits of hypoxia during expansion of urothelial cells and maturation of the bladder epithelium in the context of tissue engineering. Bladder mucosa substitutes were reconstructed using the self-assembly method with urothelial cells (UCs) expanded in normoxia or hypoxia. Hypoxia improved UCs expansion until passage P7, whereas normoxic conditions limited the use of UCs to passage P4. Maturation of the urothelium was also compared in normoxic vs. hypoxic conditions. Using laminin V, p63, Ki-67, keratin-5 a...
Canadian Urological Association Journal, 2017
Vesicoureteral reflux (VUR) is one of the most common pathologies encountered in pediatric urolog... more 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.
Scientifica, 2016
Despite the emergence of serum-free media for cell culture, the use of serum to supplement the cu... more Despite the emergence of serum-free media for cell culture, the use of serum to supplement the culture media is still essential in order to produce engineered urologic tissues using the self-assembly approach, not only for the stromal compartment but also for the uroepithelium. Effects of sera on thickness of these two compartments were measured and quality of the epithelial differentiation was evaluated. For bladder mucosa substitute reconstruction, the use of postnatal sera failed to produce an adequate uroepithelium whereas the fetal sera supplementation did. Postnatal sera also provided thinner stromal compartments than the one obtained using fetal sera, no matter if the fibroblasts from healthy or psoriatic donors were used to reconstruct human skin substitutes.