[Show abstract][Hide abstract] ABSTRACT: Objectives:
Mesenchymal stem cells derived from human amniotic fluid (hAFSCs) are a promising source for cellular therapy, especially for renal disorders, as a subpopulation is derived from the fetal urinary tract. The purpose of this study was to evaluate if hAFSCs with a renal progenitor phenotype demonstrate a nephroprotective effect in acute ischemia reperfusion (I/R) model and prevent late stage fibrosis.
A total of 45 male 12-wk-old Wistar rats were divided into three equal groups;: rats subjected to I/R injury and treated with Chang Medium, rats subjected to I/R injury and treated with hAFSCs and sham-operated animals. In the first part of this study, hAFSCs that highly expressed CD24, CD117, SIX2 and PAX2 were isolated and characterized. In the second part, renal I/R injury was induced in male rats and cellular treatment was performed 6 hours later via arterial injection. Functional and histological analyses were performed 24 hours, 48 hours and 2 months after treatment using serum creatinine, urine protein to creatinine ratio, inflammatory and regeneration markers and histomorphometric analysis of the kidney. Statistical analysis was performed by analysis of variance followed by the Tukey's test for multiple comparisons or by nonparametric Kruskal-Wallis followed by Dunn. Statistical significance level was defined as p <0.05.
hAFSCs treatment resulted in significantly reduced serum creatinine level at 24 hours, less tubular necrosis, less hyaline cast formation, higher proliferation index, less inflammatory cell infiltration and less myofibroblasts at 48h. The treated group had less fibrosis and proteinuria at 2 months after injury.
hAFSCs contain a renal progenitor cell subpopulation that has a nephroprotective effect when delivered intra-arterially in rats with renal I/R injury, and reduces interstitial fibrosis on long term follow-up.
PLoS ONE 09/2015; 10(8). DOI:10.1371/journal.pone.0136145 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Lung hypoplasia in congenital diaphragmatic hernia (CDH) is a life-threatening birth defect. Severe cases can be offered tracheal occlusion to boost prenatal lung development, though defining those to benefit remains challenging. Metabonomics of 1H NMR spectra collected from amniotic fluid (AF) can identify general changes in diseased versus healthy fetuses. AF contains lung secretions, hence, might reflect pulmonary characteristics among general markers of disease in CDH fetuses. AF from 81 healthy and 22 CDH fetuses was collected. NMR spectroscopy was performed at 400 MHz to compare AF from fetuses with CDH against controls. Several advanced feature extraction methods based on statistical tests which explore spectral variability, similarity and dissimilarity were applied and compared. This resulted in the identification of 30 spectral regions, which accounted for 80% variability between CDH and controls. Combination with automated classification discriminates AF from CDH versus healthy fetuses with 86% accuracy. Within the identified spectral regions isoleucine, leucine, valine, pyruvate, GABA, glutamate, glutamine, citrate, creatine, creatinine, taurine and glucose were the most concentrated metabolites. As the metabolite pattern of AF changes with fetal development, we have excluded metabolites with a high age-related variability and repeated the analysis with twelve spectral regions, which has resulted in similar classification accuracy. From this analysis, it was possible to distinguish between AF from fetuses with CDH from healthy controls independent of gestational age dependent metabolic changes.
Journal of Proteome Research 09/2015; DOI:10.1021/acs.jproteome.5b00131 · 4.25 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The neonatal management of preterm born infants often results in damage to the developing lung and subsequent morbidity, referred to as bronchopulmonary dysplasia (BPD). Animal models may help in understanding the molecular processes involved in this condition and define therapeutic targets. Our goal was to identify molecular pathways using the earlier described preterm rabbit model of hyperoxia induced lung-injury. Transcriptome analysis by mRNA-sequencing was performed on lungs from preterm rabbit pups born at day 28 of gestation (term: 31 days) and kept in hyperoxia (95% O2) for 7 days. Controls were preterm pups kept in normoxia. Transcriptomic data were analyzed using Array Studio and Ingenuity Pathway Analysis (IPA), in order to identify the central molecules responsible for the observed transcriptional changes. We detected 2217 significantly dysregulated transcripts following hyperoxia, of which 90% could be identified. Major pathophysiological dysregulations were found in inflammation, lung development, vascular development and reactive oxygen species (ROS) metabolism. To conclude, amongst the many dysregulated transcripts, major changes were found in the inflammatory, oxidative stress and lung developmental pathways. This information may be used for the generation of new treatment hypotheses for hyperoxia-induced lung injury and BPD.
PLoS ONE 08/2015; 10(8):e0136569. DOI:10.1371/journal.pone.0136569 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Fetoscopic laser surgery for twin-twin transfusion syndrome is a procedure for which no objective tools exist to assess technical skills. To ensure that future fetal surgeons reach competence prior to performing the procedure unsupervised, we developed a performance assessment tool. The aim of this study was to validate this assessment tool for reliability and construct validity.
A procedure-specific evaluation instrument containing all essential steps of the fetoscopic laser procedure was created using Delphi methodology. Eleven experts and 13 novices from three Fetal Medicine centers performed the procedure on the same simulator. Two independent observers assessed each surgery using the instrument (maximum score: 52). Inter-observer reliability was assessed using Spearman correlation. We compared performance of novices and experts to assess construct validity.
Inter-observer reliability was high (r=0.974, p<0.001). Checklist scores for experts and novices were significantly different: median score for novices was 28/52 (54%) while for experts 42/52 (81%) (p<0.001). Procedure time and fetoscopy time were significantly shorter (p<0.001) for experts. Residual anastomoses were found in 1/11 (9%) procedures performed by experts and in 9/14 (64%) performed by novices (p=0.006). Multivariate analysis showed that the checklist score independently from age and gender predicted competence.
The procedure-specific assessment tool for fetoscopic laser surgery shows a good inter-observer reliability and discriminates experts from novices. This instrument may therefore be a useful tool in the training curriculum for starting fetal surgeons. Further intervention studies with reassessment before and after training may increase the construct validity of the tool.
This article is protected by copyright. All rights reserved.
Ultrasound in Obstetrics and Gynecology 08/2015; DOI:10.1002/uog.15734 · 3.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Fetal surgery has become a clinical reality, with interventions for twin-to-twin transfusion syndrome (TTTS) and spina bifida demonstrated to improve outcome. Fetal imaging is evolving, with the use of 3D ultrasound and fetal MRI becoming more common in clinical practise. Medical imaging analysis is also changing, with technology being developed to assist surgeons by creating 3D virtual models that improve understanding of complex anatomy, and prove powerful tools in surgical planning and intraoperative guidance. We introduce the concept of computer-assisted surgical planning, and present the results of a systematic review of image reconstruction for fetal surgical planning that identified six articles using such technology. Indications from other specialities suggest a benefit of surgical planning and guidance to improve outcomes. There is therefore an urgent need to develop fetal-specific technology in order to improve fetal surgical outcome.
This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Neonates with congenital diaphragmatic hernia and large defects often require patch closure. Acellular collagen matrices (ACM) have been suggested as an alternative to synthetic durable patches as they are remodeled by the host or could also be used for tissue engineering purposes.
2.0x1.0 cm diaphragmatic defects were created in 6-weeks old New-Zealand white rabbits. We compared reconstruction with a purpose-designed cross-linked ACM (Matricel) to 4-layer non-cross-linked small intestinal submucosa (SIS) and a 1-layer synthetic Dual Mesh (Gore-Tex). Unoperated animals or animals undergoing primary closure (4/0 polyglecaprone) served as age-matched controls. 60 (n = 25) resp. 90 (n = 17) days later, animals underwent chest x-ray and obduction for gross examination of explants, scoring of adhesion and inflammatory response. Also, uniaxial tensiometry was done, comparing explants to contralateral native diaphragmatic tissue.
Overall weight nearly doubled from 1,554±242 g at surgery to 2,837±265 g at obduction (+84%). X-rays did show rare elevation of the left diaphragm (SIS = 1, Gore-Tex = 1, unoperated control = 1), but no herniation of abdominal organs. 56% of SIS and 10% of Matricel patches degraded with visceral bulging in four (SIS = 3, Matricel = 1). Adhesion scores were limited: 0.5 (Matricel) to 1 (SIS, Gore-Tex) to the left lung (p = 0.008) and 2.5 (Gore-Tex), 3 (SIS) and 4 (Matricel) to the liver (p<0.0001). Tensiometry revealed a reduced bursting strength but normal compliance for SIS. Compliance was reduced in Matricel and Gore-Tex (p<0.01). Inflammatory response was characterized by a more polymorphonuclear cell (SIS) resp. macrophage (Matricel) type of infiltrate (p<0.05). Fibrosis was similar for all groups, except there was less mature collagen deposited to Gore-Tex implants (p<0.05).
Matricel induced a macrophage-dominated inflammatory response, more adhesions, had appropriate strength but a lesser compliance compared to native tissue. The herein investigated ACM is not a viable option for CDH repair.
PLoS ONE 07/2015; 10(7):e0132021. DOI:10.1371/journal.pone.0132021 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To assess in vivo changes in lung and liver volume in fetuses with isolated congenital diaphragmatic hernia (CDH), either expectantly managed or treated in utero.
This is a secondary analysis of prospectively collected data at 2 fetal therapy centers. We used archived magnetic resonance (MR) images of fetuses taken ≥7 days apart, creating paired observations in 20 expectantly managed cases, 41 with a second MR prior to balloon reversal and 64 after balloon removal. We measured observed to expected total fetal lung volume (O/E TFLV) and liver-to-thoracic volume ratio (LiTR). We calculated changes in volume as compared to the initial measurement and its rate as a function of gestational age (GA) at occlusion.
The LiTR did not change in either group. In expectantly managed fetuses, O/E TFLV did not increase with gestation. In fetuses undergoing tracheal occlusion (TO) the measured increase in volume was 2.6-times larger with balloon in place as compared to after its removal. GA at TO was an independent predictor of the O/E TFLV. The net rate seems to initially increase and plateau at a maximum of 1.5%/week by 35-45 days after occlusion.
TO induces a net increase in volume, its magnitude essentially dependent on the GA at occlusion. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: To evaluate the effect of a newly developed training curriculum on performance of fetoscopic laser surgery for twin-twin transfusion syndrome (TTTS) using an advanced high-fidelity simulator model.
Ten novices were randomized to receive verbal instructions and skills training using the simulator (study group, n = 5) or no training (control group, n = 5). Both groups were evaluated with a pre-training test and post-training test. Assessment was performed by two independent observers and compromised a 52-item checklist for surgical performance (SP score), measurement of procedure time and number of anastomoses missed. Face validity and educational value of the simulator were assessed using a questionnaire. Eleven experts set the benchmark level of performance.
Both groups showed an improvement in SP score compared to the pre-training test. The simulator-trained group significantly outperformed the control group with a median SP score of 28 (54%) in the pre-test and 46 (88%) in the post-test versus 25 (48%) and 36 (69%) (p = 0.008). Procedure time decreased 11 min in the study group versus 1 min in the control group; to 32 min versus 38 min, respectively (p = 0.69). The number of missed anastomoses was not different between groups (1 versus none). Feedback provided by the participants indicated that training on the simulator was perceived as a useful educational activity.
Proficiency-based simulator training improves performance on surgical performance score for fetoscopic laser therapy. Despite the small sample size of this study practice on a simulator is recommended before trainees carry out laser therapy for TTTS in pregnant women.
This article is protected by copyright. All rights reserved.
Ultrasound in Obstetrics and Gynecology 06/2015; 46(3). DOI:10.1002/uog.14916 · 3.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study aims to compare the mechanical behavior of synthetic meshes used for pelvic organ prolapse (POP) and hernia repair. The analysis is based on a comprehensive experimental protocol, which included uniaxial and biaxial tension, cyclic loading and testing of meshes in dry conditions and embedded into an elastomer matrix. Implants are grouped as POP or hernia meshes, as indicated by the manufacturer, and their stiffness in different loading configurations, area density and porosity are compared. Hernia meshes might be expected to be stiffer, since they are implanted into a stiffer tissue (abdominal wall) than POP meshes (vaginal wall). Contrary to this, hernia meshes have a generally lower secant stiffness than POP meshes. For example, DynaMesh PRS, a POP mesh, is up to two orders of magnitude stiffer in all tested configurations than DynaMesh ENDOLAP, a hernia mesh. Additionally, lighter, large pore implants might be expected to be more compliant, which was shown to be generally not true. In particular, Restorelle, the lightest mesh with the largest pores, is less compliant in the tested configurations than Surgipro, the heaviest, small-pore implant. Our study raises the question of defining a meaningful design target for meshes in terms of mechanical biocompatibility.
[Show abstract][Hide abstract] ABSTRACT: The properties of meshes used in reconstructive surgery affect the host response and biomechanical characteristics of the grafted tissue. Whereas durable synthetics induce a chronic inflammation, biological grafts are usually considered as more biocompatible. The location of implantation is another determinant of the host response: the vagina is a different environment with specific function and anatomy. Herein, we evaluated a cross-linked acellular collagen matrix (ACM), pretreated by the anti-calcification procedure ADAPT® in a sheep model for vaginal surgery. Ten sheep were implanted with a cross-linked ACM, and six controls were implanted with a polypropylene (PP; 56 g/m2) control. One implant was inserted in the lower rectovaginal septum, and one was used for abdominal wall defect reconstruction. Grafts were removed after 180 days; all graft-related complications were recorded, and explants underwent bi-axial tensiometry and contractility testing. Half of ACM-implanted animals had palpable induration in the vaginal implantation area, two of these also on the abdominal implant. One animal had a vaginal exposure. Vaginal ACMs were 63 % less stiff compared to abdominal ACM explants (p = 0.01) but comparable to vaginal PP explants. Seven anterior vaginal ACM explants showed areas of graft degradation on histology. There was no overall difference in vaginal contractility. Considering histologic degradation in the anterior vaginal implant as representative for the host, posterior ACM explants of animals with degradation had a 60 % reduced contractility as compared to PP (p = 0.048). Three abdominal implants showed histologic degradation; those were more compliant than non-degraded implants. Vaginal implantation with ACM was associated with graft-related complications (GRCs) and biomechanical properties comparable to PP. Partially degraded ACM had a decreased vaginal contractility.
Gynecological Surgery 05/2015; 12(2). DOI:10.1007/s10397-015-0883-7
[Show abstract][Hide abstract] ABSTRACT: Our primary objective was to develop relevant algorithms for quantification of mesh position and 3D shape in magnetic resonance (MR) images.
In this proof-of-principle study, one patient with severe anterior vaginal wall prolapse was implanted with an MR-visible mesh. High-resolution MR images of the pelvis were acquired 6 weeks and 8 months postsurgery. 3D models were created using semiautomatic segmentation techniques. Conformational changes were recorded quantitatively using part-comparison analysis. An ellipticity measure is proposed to record longitudinal conformational changes in the mesh arms. The surface that is the effective reinforcement provided by the mesh is calculated using a novel methodology. The area of this surface is the effective support area (ESA).
MR-visible mesh was clearly outlined in the images, which allowed us to longitudinally quantify mesh configuration between 6 weeks and 8 months after implantation. No significant changes were found in mesh position, effective support area, conformation of the mesh's main body, and arm length during the period of observation. Ellipticity profiles show longitudinal conformational changes in posterior arms.
This paper proposes novel methodologies for a systematic 3D assessment of the position and morphology of MR-visible meshes. A novel semiautomatic tool was developed to calculate the effective area of support provided by the mesh, a potentially clinically important parameter.
International Urogynecology Journal 03/2015; DOI:10.1007/s00192-015-2681-1 · 1.96 Impact Factor