68Ga-NODAGA-Exendin-4 PET/CT Improves the Detection of Focal Congenital Hyperinsulinism.

Surgery with curative intent can be offered to congenital hyperinsulinism (CHI) patients, provided that the lesion is focal. Radiolabeled exendin-4 specifically binds the glucagonlike peptide 1 receptor on pancreatic ß-cells. In this study, we compared the performance of 18F-DOPA PET/CT, the current standard imaging method for CHI, and PET/CT with the new tracer 68Ga-NODAGA-exendin-4 in the preoperative detection of focal CHI. Methods: Nineteen CHI patients underwent both 18F-DOPA PET/CT and 68Ga-NODAGA-exendin-4 PET/CT before surgery. The images were evaluated in 3 settings: a standard clinical reading, a masked expert reading, and a joint reading. The target (lesion)-to-nontarget (normal pancreas) ratio was determined using SUVmax Image quality was rated by pediatric surgeons in a questionnaire. Results: Fourteen of 19 patients having focal lesions underwent surgery. On the basis of clinical readings, the sensitivity of 68Ga-NODAGA-exendin-4 PET/CT (100%; 95% CI, 77%-100%) was higher than that of 18F-DOPA PET/CT (71%; 95% CI, 42%-92%). Interobserver agreement between readings was higher for 68Ga-NODAGA-exendin-4 than for 18F-DOPA PET/CT (Fleiss κ = 0.91 vs. 0.56). 68Ga-NODAGA-exendin-4 PET/CT provided significantly (P = 0.021) higher target-to-nontarget ratios (2.02 ± 0.65) than did 18F-DOPA PET/CT (1.40 ± 0.40). On a 5-point scale, pediatric surgeons rated 68Ga-NODAGA-exendin-4 PET/CT as superior to 18F-DOPA PET/CT. Conclusion: For the detection of focal CHI, 68Ga-NODAGA-exendin-4 PET/CT has higher clinical sensitivity and better interobserver correlation than 18F-DOPA PET/CT. Better contrast and image quality make 68Ga-NODAGA-exendin-4 PET/CT superior to 18F-DOPA PET/CT in surgeons' intraoperative quest for lesion localization.

Aortopexy for the treatment of tracheo - broncho - malacia in children.

Aortopexy has been demonstrated to be an effective procedure for the treatment of tracheo(broncho)malacia in children. Several operative approaches have been proposed in the literature, including left anterior thoracotomy, right thoracotomy, full median sternotomy, or a thoracoscopic approach. In this video tutorial we present our technique for anterior aortopexy using a limited upper sternotomy.

Airway tissue engineering for congenital laryngotracheal disease.

Regenerative medicine offers hope of a sustainable solution for severe airway disease by the creation of functional, immunocompatible organ replacements. When considering fetuses and newborns, there is a specific spectrum of airway pathologies that could benefit from cell therapy and tissue engineering applications. While hypoplastic lungs associated with congenital diaphragmatic hernia (CDH) could benefit from cellular based treatments aimed at ameliorating lung function, patients with upper airway obstruction could take advantage from a de novo tissue engineering approach. Moreover, the international acceptance of the EXIT procedure as a means of securing the precarious neonatal airway, together with the advent of fetal surgery as a method of heading off postnatal co-morbidities, offers the revolutionary possibility of extending the clinical indication for tissue-engineered airway transplantation to infants affected by diverse severe congenital laryngotracheal malformations. This article outlines the necessary basic components for regenerative medicine solutions in this potential clinical niche.

Pdx1 and controlled culture conditions induced differentiation of human amniotic fluid-derived stem cells to insulin-producing clusters.

This study investigated the differentiation of human amniotic fluid-derived stem cells (hAFSCs) into insulin-producing clusters in vitro. Adenovirally-delivered mouse Pdx1 (Ad-Pdx1) induced human Pdx1 expression in hAFSCs and enhanced the coordinated expression of downstream ß-cell markers. When Ad-Pdx1-transduced hAFSCs were sequentially treated with activin A, bFGF and nicotinamide and the culture plate surface coated with poly-l-ornithine, the expression of islet-associated human mRNAs for Pdx1, Pax6, Ngn3 and insulin was increased. C-peptide ELISA confirmed that Ad-Pdx1-transduced hAFSCs processed and secreted insulin in a manner consistent with that pathway in pancreatic ß-cells. To sustain the ß-cell-like phenotype and investigate the effect of three-dimensional (3D) conformation on the differentiation of hAFSCs, Pdx1-transduced cells were encapsulated in alginate and cultured long-term under serum-free conditions. Over 2 weeks, partially differentiated hAFSC clusters increased in size and increased insulin secretion. Taken together, these data demonstrate that ectopic Pdx1 expression initiates pancreatic differentiation in hAFSCs and that a ß-cell-like phenotype can be augmented by culture conditions that mimic the stromal components and 3D geometry associated with pancreatic islets.

Routine isolation and expansion late mid trimester amniotic fluid derived mesenchymal stem cells in a cohort of fetuses with congenital diaphragmatic hernia.

OBJECTIVE: To assess the feasibility of routine isolation and expansion of amniotic fluid derived mesenchymal stem cells (AF-MSC) in fetuses diagnosed with isolated congenital diaphragmatic hernia (CDH). STUDY DESIGN: Redundant AF samples of fetuses with CDH and normal fetuses were obtained. Cell colonies were mechanically selected for each sample. Proliferation capacity was expressed as population doubling time (PDT). Cell lines were further characterized with flow cytometry, differentiation assays and qRT-PCR (OCT4 and NANOG). After cell labeling with LacZ in vivo tracking was performed after fetal tracheal injection in rabbits. RESULTS: Fourteen consecutive CDH samples (median gestational age (GA) of 32.9 weeks; IQR: 27.8-34.3 weeks) and seven control samples (30 weeks; IQR: 28.9-34.4 weeks) were obtained. PDT was similar in both groups (45.4h±1.9 vs. 52.3h±3.4;NS). AF-MSCs expressed a typical mesenchymal CD marker profile. Clones could be differentiated in osteogenic, adipogenic and chrondrogenic lineages. Expression of multipotency markers was low in all cell lines. We confirmed the presence of injected cells inside the fetal lung three days after intratracheal injection. CONCLUSION: Routine isolation and expansion of AF-MSCs in CDH is feasible and cell lines generated were comparable to those of control samples. AF-MSCs from affected fetuses could potentially be used in future stem cell therapy.

In utero therapy for congenital disorders using amniotic fluid stem cells.

Congenital diseases are responsible for over a third of all pediatric hospital admissions. Advances in prenatal screening and molecular diagnosis have allowed the detection of many life-threatening genetic diseases early in gestation. In utero transplantation (IUT) with stem cells could cure affected fetuses but so far in humans, successful IUT using allogeneic hematopoietic stem cells (HSCs), has been limited to fetuses with severe immunologic defects and more recently IUT with allogeneic mesenchymal stem cell transplantation, has improved phenotype in osteogenesis imperfecta. The options of preemptive treatment of congenital diseases in utero by stem cell or gene therapy changes the perspective of congenital diseases since it may avoid the need for postnatal treatment and reduce future costs. Amniotic fluid stem (AFS) cells have been isolated and characterized in human, mice, rodents, rabbit, and sheep and are a potential source of cells for therapeutic applications in disorders for treatment prenatally or postnatally. Gene transfer to the cells with long-term transgenic protein expression is feasible. Recently, pre-clinical autologous transplantation of transduced cells has been achieved in fetal sheep using minimally invasive ultrasound guided injection techniques. Clinically relevant levels of transgenic protein were expressed in the blood of transplanted lambs for at least 6 months. The cells have also demonstrated the potential of repair in a range of pre-clinical disease models such as neurological disorders, tracheal repair, bladder injury, and diaphragmatic hernia repair in neonates or adults. These results have been encouraging, and bring personalized tissue engineering for prenatal treatment of genetic disorders closer to the clinic.

Gastrostomy insertion in children: percutaneous endoscopic or percutaneous image-guided?

BACKGROUND/PURPOSE: Gastrostomy insertion in children can be performed in many ways, but which is the best technique remains uncertain. This study evaluates the outcome of percutaneous endoscopic gastrostomy (PEG) and image-guided gastrostomy (IG). METHODS: We reviewed children who had either PEG (n = 136) inserted by pediatric surgeons or IG (n = 195) inserted by interventional radiologists in our hospital between May 2004 and July 2008. Gastrostomy-related complications were given scores ranging from 20 for major complications (eg, peritonitis, gastrointestinal bleed, and visceral injury) to 1 for minor (eg, site infection and tube migration), and total score per month of follow-up was calculated per patient. RESULTS: Conversion to laparoscopic or open gastrostomy was more frequent in PEG versus IG (P = .001). Fewer PEG patients (28%) had complications than did IG (47%) (P = .001). One PEG patient developed a gastrocolic fistula. In the IG group, 2 patients had transverse colon puncture, 1 had intraperitoneal tube detachment, and 1 had upper gastrointestinal bleeding. When scored and adjusted by length of follow-up, PEG had lower scores compared with IG, indicating a better outcome (P = .03). These findings were supported by zero-inflated Poisson regression analysis. CONCLUSION: Major complications were rare and observed more frequently after IG. Minor complications were observed in both procedures but were significantly less common in PEG.

Principals of neovascularization for tissue engineering.

The goals in tissue engineering include the replacement of damaged, injured or missing body tissues with biological compatible substitutes such as bioengineered tissues. However, due to an initial mass loss after implantation, improved vascularization of the regenerated tissue is essential. Recent advances in understanding the process of blood vessel growth has offered significant tools for therapeutic neovascularization. Several angiogenic growth factors including vascular endothelial cell growth factor (VEGF) and basic fibroblast growth factor (bFGF) were used for vascularization of ischemic tissues. Three approaches have been used for vascularization of bioengineered tissue: incorporation of angiogenic factors in the bioengineered tissue, seeding endothelial cells with other cell types and prevascularization of matrices prior to cell seeding. This paper reviews the process of blood vessel growth and tissue vascularization, and discuss strategies for efficient vascularization of engineered tissues.