Novel Neonatal Umbilical Catheter Protection and Stabilization Device in In vitro Model of Catheterized Human Umbilical Cords: Effect of Material and Venting on Bacterial Colonization.
American journal of perinatology
OBJECTIVE: Umbilical central lines deliver life-saving medications and nutrition for neonates; however, complications associated with umbilical catheters (UCs) occur more frequently than in adults with central lines (i.e., line migration, systemic infection). We have developed a device for neonatal UC protection and stabilization to reduce catheter exposure to bacteria compared with the standard of care: "goal post" tape configuration. This study analyzes the effect of device venting and material on bacterial load of human umbilical cords in vitro.STUDY DESIGN: Catheters were inserted into human umbilical cord segments in vitro, secured with plastic or silicone vented prototype versus tape, and levels of bacterial colonization were compared between groups after 7 days of incubation.RESULTS: Nonvented plastic prototype showed increased bacterial load compared with goal post (p=0.04). Colonization was comparable between the goal post and all vented plastic prototypes (p≥0.30) and when compared with the vented silicone device (p=1).CONCLUSION: A novel silicone device does not increase external bacterial colonization compared with the current standard of care for line securement, and may provide a safe, convenient alternative to standard adhesive tape for UC stabilization. Future studies are anticipated to establish safety in vivo, alongside benefits such as migration and infection reduction.
View details for DOI 10.1055/s-0039-1700542
View details for PubMedID 31739365
Seven-Year Experience with Laparoscopic Pedicled Omental Flap for Cerebral Revascularization in Patients with Moyamoya Disease
ELSEVIER SCIENCE INC. 2019: E126–E127
View details for Web of Science ID 000492749600297
Growth of Small Intestinal Layers Proximal and Distal to the Intestine Undergoing Distraction Enterogenesis
ELSEVIER SCIENCE INC. 2019: S204
View details for Web of Science ID 000492740900390
Biomechanical signaling and collagen fiber reorientation during distraction enterogenesis.
Journal of the mechanical behavior of biomedical materials
2019; 101: 103425
Distraction enterogenesis has been extensively studied as a potential treatment for short bowel syndrome, which is the most common subset of intestinal failure. Spring distraction uses an intraluminal axial mechanical force to stimulate the growth and elongation of the small intestine. The tissue close to the distracted intestinal segment may also experience signaling to grow. In this study we examined the effects of distraction enterogenesis at different post-operative days on the thickness of small intestinal layers in the intestine proximal and distal to the distracted segment, as well as how the submucosal collagen fibers were reoriented. It was observed that not only different layers of intestine wall in distracted segment showed thickening due to the applied mechanical force but also adjacent tissues in both distal and proximal directions were impacted significantly where they showed thickening as well. The orientation of collagen fibers in submucosa layer was also significantly impacted due to the mechanical force in both distracted and adjacent tissue. The effect of the applied mechanical force on the main distracted tissue and the radial growth of the adjacent tissue strongly suggest actions of paracrine signaling.
View details for DOI 10.1016/j.jmbbm.2019.103425
View details for PubMedID 31541857
Biomechanics of small intestine during distraction enterogenesis with an intraluminal spring.
Journal of the mechanical behavior of biomedical materials
2019; 101: 103413
During recent years, distraction enterogenesis has been extensively studied as a treatment for short bowel syndrome, which is the most common cause of intestinal failure. Although different strategies such as parenteral nutrition and surgical lengthening have been used to manage the difficulties that patients with SBS deal with, these treatments are associated with high complication rates. Distraction enterogenesis uses mechanical force to increase the length and stimulate growth of the small intestine. In this study we combine in vivo experiments with computational modeling to explore the biomechanics of spring dependent distraction enterogenesis. We hypothesize that the self-expanding spring provides mechanical force for elastic tissue lengthening and triggers cellular proliferation. The additional growth of the intestine suggests signaling between mechanical stress and tissue response. We developed a computational modeling platform to test the correlation of applied mechanical force and tissue growth. We further validated our computational models with experimental measurements using spring-mediated distraction enterogenesis in a porcine model. This modeling platform can incorporate patient biometrics to estimate an individual's tissue response to spring mediated distraction enterogenesis.
View details for DOI 10.1016/j.jmbbm.2019.103413
View details for PubMedID 31518947
Pathological confirmation of pre-chemotherapy biopsied and tattooed axillary lymph nodes
SPRINGER. 2018: 426–27
View details for Web of Science ID 000433587300141
Methotrexate Chemotherapy Induces Persistent Tri-glial Dysregulation that Underlies Chemotherapy-Related Cognitive Impairment.
Chemotherapy results in a frequent yet poorly understood syndrome of long-term neurological deficits. Neural precursor cell dysfunction and white matter dysfunction are thought to contribute to this debilitating syndrome. Here, we demonstrate persistent depletion of oligodendrocyte lineage cells in humans who received chemotherapy. Developing a mouse model of methotrexate chemotherapy-induced neurological dysfunction, we find a similar depletion of white matter OPCs, increased but incomplete OPC differentiation, and a persistent deficit in myelination. OPCs from chemotherapy-naive mice similarly exhibit increased differentiation when transplanted into the microenvironment of previously methotrexate-exposed brains, indicating an underlying microenvironmental perturbation. Methotrexate results in persistent activation of microglia and subsequent astrocyte activation that is dependent on inflammatory microglia. Microglial depletion normalizes oligodendroglial lineage dynamics, myelin microstructure, and cognitive behavior after methotrexate chemotherapy. These findings indicate that methotrexate chemotherapy exposure is associated with persistent tri-glial dysregulation and identify inflammatory microglia as a therapeutic target to abrogate chemotherapy-related cognitive impairment.
View details for PubMedID 30528430
An in vitro bacterial surface migration assay underneath sterile barrier material commonly found in a hospital setting
Journal of Perinatology
2017; 27 (7): 848-852
View details for DOI 10.1038/jp.2017.28
Recurrent Pyogenic Cholangitis: Got Stones?
Digestive diseases and sciences
2016; 61 (11): 3147-3150
View details for PubMedID 26602913
Endoscopic Division of Duodenal Web Causing Near Obstruction in 2-Year-Old with Trisomy 21
JOURNAL OF LAPAROENDOSCOPIC & ADVANCED SURGICAL TECHNIQUES
2016; 26 (5): 413-417
Surgical intervention for duodenal atresia most commonly entails duodenoduodenostomy in the neonatal period. Occasionally, type I duodenal atresia with incomplete obstruction may go undiagnosed until later in life. Endoscopic approach to dividing intestinal webs has been reported as successful in patients as young as 7 days of age, and can be a useful modality particularly in patients with comorbidities who may not tolerate open or laparoscopic surgery.A 2-year-old female with a history of trisomy 21 and tetralogy of Fallot underwent laparoscopic and endoscopic exploration of intestinal obstruction as seen on upper gastrointestinal series for symptoms of recurrent emesis and weight loss. After laparoscopy confirmed a duodenal web as the cause of intestinal obstruction, endoscopic division of the membrane was carried out with a triangle tip electrocautery knife and 15 mm radially dilating balloon.The patient tolerated the procedure well, and also tolerated full age-appropriate diet by time of discharge on postoperative day 2. She remains asymptomatic as of 6 months postoperatively.This report describes a successful endoscopic approach for definitive treatment of a duodenal web in a 2-year-old girl with trisomy 21, and laparoscopy confirmed no intraabdominal obstructive process or complication from endoscopy. Endoscopy enables minimal recovery time and suggests an improved method of duodenal web division over pure surgical intervention.
View details for DOI 10.1089/lap.2015.0462
View details for Web of Science ID 000376469600014
View details for PubMedID 26913816
- Double Rarities, Double Challenges: Extra-Mammary Paget's Disease and Anal Adenocarcinoma DIGESTIVE DISEASES AND SCIENCES 2016; 61 (4): 996-999
Neuronal Activity Promotes Oligodendrogenesis and Adaptive Myelination in the Mammalian Brain
2014; 344 (6183): 487-?
Myelination of the central nervous system requires the generation of functionally mature oligodendrocytes from oligodendrocyte precursor cells (OPCs). Electrically active neurons may influence OPC function and selectively instruct myelination of an active neural circuit. In this work, we use optogenetic stimulation of the premotor cortex in awake, behaving mice to demonstrate that neuronal activity elicits a mitogenic response of neural progenitor cells and OPCs, promotes oligodendrogenesis, and increases myelination within the deep layers of the premotor cortex and subcortical white matter. We further show that this neuronal activity-regulated oligodendrogenesis and myelination is associated with improved motor function of the corresponding limb. Oligodendrogenesis and myelination appear necessary for the observed functional improvement, as epigenetic blockade of oligodendrocyte differentiation and myelin changes prevents the activity-regulated behavioral improvement.
View details for DOI 10.1126/science.1252304
View details for Web of Science ID 000335157700034
View details for PubMedCentralID PMC4096908
Effects of stress and motivation on performing a spatial task
NEUROBIOLOGY OF LEARNING AND MEMORY
2011; 95 (3): 277-285
Learning is ubiquitous in the animal kingdom but has been studied extensively in only a handful of species. Moreover, learning studied under laboratory conditions is typically unrelated to the animal's natural environment or life history. Here, we designed a task relevant to the natural behavior of male African cichlid fish (Astatotilapia burtoni), to determine if they could be trained on a spatial task to gain access to females and shelter. We measured both how successfully animals completed this task over time and whether and how immediate early gene and hormone expression profiles were related to success. While training fish in a maze, we measured time to task completion, circulating levels of three key hormones (cortisol, 11-ketotestosterone, and testosterone) and mRNA abundance of seven target genes including three immediate early genes (that served proxies for brain activity) in nine brain regions. Data from our subjects fell naturally into three phenotypes: fish that could be trained (learners), fish that could not be trained (non-learners) and fish that never attempted the task (non-attempters). Learners and non-learners had lower levels of circulating cortisol compared to fish that never attempted the task. Learners had the highest immediate early gene mRNA levels in the homologue of the hippocampus (dorsolateral telencephalon; Dl), lower cortisol (stress) levels and were more motivated to accomplish the task as measured by behavioral observations. Fish that never attempted the task showed the lowest activity within the Dl, high stress levels and little to no apparent motivation. Data from non-learners fell between these two extremes in behavior, stress, and motivation.
View details for DOI 10.1016/j.nlm.2010.12.002
View details for Web of Science ID 000288774300007
View details for PubMedID 21145980
View details for PubMedCentralID PMC3060970