Reduction of unnecessary antibiotic days in a level IV neonatal intensive care unit.

Objective: Antibiotics are widely prescribed in the neonatal intensive care unit (NICU) and duration of prescription is varied. We sought to decrease unnecessary antibiotic days for the most common indications in our outborn level IV NICU by 20% within 1 year. Design and interventions: A retrospective chart review was completed to determine the most common indications and treatment duration for antibiotic therapy in our 39-bed level IV NICU. A multidisciplinary team was convened to develop an antibiotic stewardship quality improvement initiative with new consensus guidelines for antibiotic duration for these common indications. To optimize compliance, prospective audit was completed to ensure antibiotic stop dates were utilized and provider justification for treatment duration was documented. Multiple rounds of educational sessions were conducted with neonatology providers. Results: In total, 262 patients were prescribed antibiotics (139 in baseline period and 123 after the intervention). The percentage of unnecessary antibiotic days (UAD) was defined as days beyond the consensus guidelines. As a balancing measure, reinitiation of antibiotics within 2 weeks was tracked. After sequential interventions, the percentage of UAD decreased from 42% to 12%, which exceeded our goal of a 20% decrease. Compliance with antibiotic stop dates increased from 32% to 76%, and no antibiotics were reinitiated within 2 weeks. Conclusions: A multidisciplinary antibiotic stewardship team coupled with a consensus for antibiotic therapy duration, prescriber justification of antibiotic necessity and use of antibiotic stop dates can effectively reduce unnecessary antibiotic exposure in the NICU.

Standardized Scoring Tool and Weaning Guideline to Reduce Opioids in Critically Ill Neonates.

Introduction: Pain impacts brain development for neonates, causing deleterious neurodevelopmental outcomes. Prescription opioids for analgesia or sedation are common; however, prolonged opioid exposure in neonates is associated with neurodevelopmental impairment. Balancing the impact of inadequate pain control against prolonged opioid exposure in neonates is a clinical paradox. Therefore, we sought to decrease the average days of opioids used for analgesia or sedation in critically ill neonates at a level IV Neonatal Intensive Care Unit by 10% within 1 year. Methods: A multidisciplinary quality improvement team used the model for improvement, beginning with a Pareto analysis, and identified a lack of consistent approach to weaning opioids as a primary driver for prolonged exposure. The team utilized 2 main interventions: (1) a standardized withdrawal assessment tool-1 and (2) a risk-stratified opioid weaning guideline. Results: We demonstrated a reduction in mean opioid duration from 34.3 to 14.1 days, an increase in nursing withdrawal assessment tool-1 documentation from 20% to 90%, and an increase in the documented rationale for daily opioid dose in provider notes from 20% to 70%. Benzodiazepine use did not change. Conclusion: Standardized withdrawal assessments combined with risk-stratified weaning guidelines can decrease opioid use in critically ill neonates.

High-throughput microscopy reveals the impact of multifactorial environmental perturbations on colorectal cancer cell growth.

BACKGROUND: Colorectal cancer (CRC) mortality is principally due to metastatic disease, with the most frequent organ of metastasis being the liver. Biochemical and mechanical factors residing in the tumor microenvironment are considered to play a pivotal role in metastatic growth and response to therapy. However, it is difficult to study the tumor microenvironment systematically owing to a lack of fully controlled model systems that can be investigated in rigorous detail. RESULTS: We present a quantitative imaging dataset of CRC cell growth dynamics influenced by in vivo-mimicking conditions. They consist of tumor cells grown in various biochemical and biomechanical microenvironmental contexts. These contexts include varying oxygen and drug concentrations, and growth on conventional stiff plastic, softer matrices, and bioengineered acellular liver extracellular matrix. Growth rate analyses under these conditions were performed via the cell phenotype digitizer (CellPD). CONCLUSIONS: Our data indicate that the growth of highly aggressive HCT116 cells is affected by oxygen, substrate stiffness, and liver extracellular matrix. In addition, hypoxia has a protective effect against oxaliplatin-induced cytotoxicity on plastic and liver extracellular matrix. This expansive dataset of CRC cell growth measurements under in situ relevant environmental perturbations provides insights into critical tumor microenvironment features contributing to metastatic seeding and tumor growth. Such insights are essential to dynamical modeling and understanding the multicellular tumor-stroma dynamics that contribute to metastatic colonization. It also establishes a benchmark dataset for training and testing data-driven dynamical models of cancer cell lines and therapeutic response in a variety of microenvironmental conditions.

Evaluating Interaction of Cord Blood Hematopoietic Stem/Progenitor Cells with Functionally Integrated Three-Dimensional Microenvironments.

Despite advances in ex vivo expansion of cord blood-derived hematopoietic stem/progenitor cells (CB-HSPC), challenges still remain regarding the ability to obtain, from a single unit, sufficient numbers of cells to treat an adolescent or adult patient. We and others have shown that CB-HSPC can be expanded ex vivo in two-dimensional (2D) cultures, but the absolute percentage of the more primitive stem cells decreases with time. During development, the fetal liver is the main site of HSPC expansion. Therefore, here we investigated, in vitro, the outcome of interactions of primitive HSPC with surrogate fetal liver environments. We compared bioengineered liver constructs made from a natural three-dimensional-liver-extracellular-matrix (3D-ECM) seeded with hepatoblasts, fetal liver-derived (LvSt), or bone marrow-derived stromal cells, to their respective 2D culture counterparts. We showed that the inclusion of cellular components within the 3D-ECM scaffolds was necessary for maintenance of HSPC viability in culture, and that irrespective of the microenvironment used, the 3D-ECM structures led to the maintenance of a more primitive subpopulation of HSPC, as determined by flow cytometry and colony forming assays. In addition, we showed that the timing and extent of expansion depends upon the biological component used, with LvSt providing the optimal balance between preservation of primitive CB HSPC and cellular differentiation. Stem Cells Translational Medicine 2018;7:271-282.

Self-assembled liver organoids recapitulate hepatobiliary organogenesis in vitro.

Several three-dimensional cell culture systems are currently available to create liver organoids. In gneral, these systems display better physiologic and metabolic aspects of intact liver tissue compared with two-dimensional culture systems. However, none reliably mimic human liver development, including parallel formation of hepatocyte and cholangiocyte anatomical structures. Here, we show that human fetal liver progenitor cells self-assembled inside acellular liver extracellular matrix scaffolds to form three-dimensional liver organoids that recapitulated several aspects of hepatobiliary organogenesis and resulted in concomitant formation of progressively more differentiated hepatocytes and bile duct structures. The duct morphogenesis process was interrupted by inhibiting Notch signaling, in an attempt to create a liver developmental disease model with a similar phenotype to Alagille syndrome. Conclusion: In the current study, we created an in vitro model of human liver development and disease, physiology, and metabolism, supported by liver extracellular matrix substrata; we envision that it will be used in the future to study mechanisms of hepatic and biliary development and for disease modeling and drug screening. (Hepatology 2018;67:750-761).

Fluid Flow Regulation of Revascularization and Cellular Organization in a Bioengineered Liver Platform.

OBJECTIVE: Modeling of human liver development, especially cellular organization and the mechanisms underlying it, is fundamental for studying liver organogenesis and congenital diseases, yet there are no reliable models that mimic these processes ex vivo. DESIGN: Using an organ engineering approach and relevant cell lines, we designed a perfusion system that delivers discrete mechanical forces inside an acellular liver extracellular matrix scaffold to study the effects of mechanical stimulation in hepatic tissue organization. RESULTS: We observed a fluid flow rate-dependent response in cell distribution within the liver scaffold. Next, we determined the role of nitric oxide (NO) as a mediator of fluid flow effects on endothelial cells. We observed impairment of both neovascularization and liver tissue organization in the presence of selective inhibition of endothelial NO synthase. Similar results were observed in bioengineered livers grown under static conditions. CONCLUSION: Overall, we were able to unveil the potential central role of discrete mechanical stimulation through the NO pathway in the revascularization and cellular organization of a bioengineered liver. Last, we propose that this organ bioengineering platform can contribute significantly to the identification of physiological mechanisms of liver organogenesis and regeneration and improve our ability to bioengineer livers for transplantation.

Whole-organ bioengineering: current tales of modern alchemy.

End-stage organ disease affects millions of people around the world, to whom organ transplantation is the only definitive cure available. However, persistent organ shortage and the resulting widespread transplant backlog are part of a disturbing reality and a common burden felt by thousands of patients on waiting lists in almost every country where organ transplants are performed. Several alternatives and potential solutions to this problem have been sought in past decades, but one seems particularly promising now: whole-organ bioengineering. This review describes briefly the evolution of organ transplantation and the development of decellularized organ scaffolds and their application to organ bioengineering. This modern alchemy of generating whole-organ scaffolds and recellularizing them with multiple cell types in perfusion bioreactors is paving the way for a new revolution in transplantation medicine. Furthermore, although the first generation of bioengineered organs still lacks true clinical value, it has created a number of novel tissue and organ model platforms with direct application in other areas of science (eg, developmental biology and stem cell biology, drug discovery, physiology and metabolism). In this review, we describe the current status and numerous applications of whole-organ bioengineering, focusing also on the multiple challenges that researchers have to overcome to translate these novel technologies fully into transplantation medicine.

Human liver bioengineering using a whole liver decellularized bioscaffold.

As a result of significant progress made in the last years in developing methods of whole organ decellularization techniques, organ bioengineering may now look more feasible than ever before. In this chapter, we describe in detail the necessary steps in human liver bioengineering. These include ferret liver decellularization by detergent perfusion, human liver progenitor and endothelial cell isolation, and finally, liver bioscaffold recellularization in a perfusion bioreactor.