Robust, 3-Dimensional Visualization of Human Colon Enteric Nervous System Without Tissue Sectioning.

Background & Aims: Small, 2-dimensional sections routinely used for human pathology analysis provide limited information about bowel innervation. We developed a technique to image human enteric nervous system (ENS) and other intramural cells in 3 dimensions.

Methods: Using mouse and human colon tissues, we developed a method that combines tissue clearing, immunohistochemistry, confocal microscopy, and quantitative analysis of full-thickness bowel without sectioning to quantify ENS and other intramural cells in 3 dimensions.

The Impact of Imaging on Negative Appendectomies for Early Appendicitis in Children.

Objectives: The rate of negative appendectomy in children is 7%. The value of imaging depends on the institution. In addition, imaging errors can lead to an appendectomy in children who do not have appendicitis.

Pediatric laryngotracheal reconstruction with tissue-engineered cartilage in a rabbit model.

Objectives/hypothesis: To develop an effective rabbit model of in vitro- and in vivo-derived tissue-engineered cartilage for laryngotracheal reconstruction (LTR).

Study Design: 1) Determination of the optimal scaffold 1% hyaluronic acid (HA), 2% HA, and polyglycolic acid (PGA) and in vitro culture time course using a pilot study of 4 by 4-mm in vitro-derived constructs analyzed on a static culture versus zero-gravity bioreactor for 4, 8, and 12 weeks, with determination of compressive modulus and histology as outcome measures. 2) Three-stage survival rabbit experiment utilizing autologous auricular chondrocytes seeded in scaffolds, either 1% HA or PGA.

Single-stage versus multi-stage pull-through for Hirschsprung's disease: practice trends and outcomes in infants.

Purpose: The aim of this study was to evaluate surgical treatments and outcomes in a multi-institutional cohort of neonates with Hirschsprung's disease (HD).

Methods: Using the Pediatric Health Information System (PHIS) from 1999 to 2009, neonates diagnosed with HD were identified and classified as having a single stage pull-through (SSPT) or multi-stage pull-through (MSPT). Diagnosis and classification algorithms and clinical variables and outcomes were validated by multi-institutional chart review.

Rotary bioreactor culture can discern specific behavior phenotypes in Trk-null and Trk-expressing neuroblastoma cell lines.

Neuroblastoma is characterized by biological and genetic heterogeneity that leads to diverse, often unpredictable, clinical behavior. Differential expression of the Trk family of neurotrophin receptors strongly correlates with clinical behavior; TrkA expression is associated with favorable outcome, whereas TrkB with unfavorable outcome. Neuroblastoma cells cultured in a microgravity rotary bioreactor spontaneously aggregate into tumor-like structures, called organoids.

Microgravity assay of neuroblastoma: in vitro aggregation kinetics and organoid morphology correlate with MYCN expression.

Neuroblastoma, the most common and deadly solid pediatric tumor, features genetic and biologic heterogeneity that defies simple risk assessments, drives diverse clinical behavior, and demands more extensive characterization. This research served to investigate the utility of a microgravity assay-rotary bioreactor culture-to evaluate and characterize the cell-specific, in vitro behavior of neuroblastoma cell lines: aggregation kinetics of single cells and the morphology of the formed structures, called organoids. Specifically, we examined the effect of amplification of the oncogene MYCN, a genetic factor that is strongly associated with poor clinical outcome.

Hepaticoduodenostomy vs hepaticojejunostomy for reconstruction after resection of choledochal cyst.

Purpose: Roux-en-Y hepaticojejunostomy (HJ) is currently the favored reconstructive procedure after resection of choledochal cysts. Hepaticoduodenostomy (HD) has been argued to be more physiologically and technically easier but is feared to have associated complications. Here we compare outcomes of the 2 procedures.

Treatment of diabetic wounds with fetal murine mesenchymal stromal cells enhances wound closure.

Diabetes impairs multiple aspects of the wound-healing response. Delayed wound healing continues to be a significant healthcare problem for which effective therapies are lacking. We have hypothesized that local delivery of mesenchymal stromal cells (MSC) at a wound might correct many of the wound-healing impairments seen in diabetic lesions.

Structural and functional characterization of bladder smooth muscle in fetal rats with retinoic acid-induced myelomeningocele.

Myelomeningocele (MMC) is the most common cause of neurogenic bladder dysfunction (NBD). We recently developed a novel retinoic acid (RA)-induced MMC model in fetal rats. The objective of this study was to use this model to assess functional and structural characteristics of the detrusor muscle in MMC-associated NBD.

Complementary roles of microtubules and microfilaments in the lung fibroblast-mediated contraction of collagen gels: Dynamics and the influence of cell density.

Fibroblasts are important cellular components in wound healing, scar formation, and fibrotic disorders; and the fibroblast-populated collagen-gel (FPCG) model allows examination of fibroblast behavior in an in vitro three-dimensional environment similar to that in vivo. Contraction of free-floating FPCGs depends on an active and dynamic cytoskeleton, and the contraction dynamics are highly influenced by cell density. We investigated mechanistic differences between high- and low-cell density FPCG contraction by evaluating contraction dynamics in detail, using specific cytoskeletal disruptors.

Collagen crosslinking and cell density have distinct effects on fibroblast-mediated contraction of collagen gels.

Background/purpose: Fibroblasts are actively and dynamically involved in wound healing (dermal regeneration, wound contraction, and scar contracture) and fibrosis. Fibroblast-seeded collagen gels provide an in vitro model for these processes. Over time, fibroblasts will contract the gels, but the mechanisms are not completely understood.

Real-time, high-definition, three-dimensional microscopy for evaluating problematic cervical Papanicolaou smears classified as atypical squamous cells of undetermined significance.

Background: The perceived inadequacies of the cervical Papanicolaou (Pap) smear have been attributed to sampling, screening, or interpretive errors. Within this type of cytologic preparation, there are thick cell clusters in which the cells are obscured. It may not possible to evaluate these areas by conventional microscopy.

Engineering a composite neotrachea with surgical adhesives.

Background/purpose: Reconstructive surgery often is limited by the availability of normal tissue. Tissue engineering provides promise in the development of "artificial tissues." The purpose of this study was to test the efficacy and viability of the use of a biologic surgical adhesive TISSEEL in combining engineered bronchial epithelium with engineered cartilage.