A PLURIPOTENT STEM CELL PLATFORM FOR IN VITRO SYSTEMS GENETICS STUDIES OF MOUSE DEVELOPMENT.

The directed differentiation of pluripotent stem cells (PSCs) from panels of genetically diverse individuals is emerging as a powerful experimental system for characterizing the impact of natural genetic variation on developing cell types and tissues. Here, we establish new PSC lines and experimental approaches for modeling embryonic development in a genetically diverse, outbred mouse stock (Diversity Outbred mice). We show that a range of inbred and outbred PSC lines can be stably maintained in the primed pluripotent state (epiblast stem cells -- EpiSCs) and establish the contribution of genetic variation to phenotypic differences in gene regulation and directed differentiation. Using pooled in vitro fertilization, we generate and characterize a genetic reference panel of Diversity Outbred PSCs (n = 230). Finally, we demonstrate the feasibility of pooled culture of Diversity Outbred EpiSCs as "cell villages", which can facilitate the differentiation of large numbers of EpiSC lines for forward genetic screens. These data can complement and inform similar efforts within the stem cell biology and human genetics communities to model the impact of natural genetic variation on phenotypic variation and disease-risk.

Engineering Programmable Material-To-Cell Pathways Via Synthetic Notch Receptors To Spatially Control Cellular Phenotypes In Multi-Cellular Constructs.

Synthetic Notch (synNotch) receptors are modular synthetic components that are genetically engineered into mammalian cells to detect signals presented by neighboring cells and respond by activating prescribed transcriptional programs. To date, synNotch has been used to program therapeutic cells and pattern morphogenesis in multicellular systems. However, cell-presented ligands have limited versatility for applications that require spatial precision, such as tissue engineering. To address this, we developed a suite of materials to activate synNotch receptors and serve as generalizable platforms for generating user-defined material-to-cell signaling pathways. First, we demonstrate that synNotch ligands, such as GFP, can be conjugated to cell- generated ECM proteins via genetic engineering of fibronectin produced by fibroblasts. We then used enzymatic or click chemistry to covalently link synNotch ligands to gelatin polymers to activate synNotch receptors in cells grown on or within a hydrogel. To achieve microscale control over synNotch activation in cell monolayers, we microcontact printed synNotch ligands onto a surface. We also patterned tissues comprising cells with up to three distinct phenotypes by engineering cells with two distinct synthetic pathways and culturing them on surfaces microfluidically patterned with two synNotch ligands. We showcase this technology by co-transdifferentiating fibroblasts into skeletal muscle or endothelial cell precursors in user-defined spatial patterns towards the engineering of muscle tissue with prescribed vascular networks. Collectively, this suite of approaches extends the synNotch toolkit and provides novel avenues for spatially controlling cellular phenotypes in mammalian multicellular systems, with many broad applications in developmental biology, synthetic morphogenesis, human tissue modeling, and regenerative medicine.

The Veterans Precision Oncology Data Commons: Transforming VA data into a national resource for research in precision oncology.

The Department of Veterans Affairs (VA) has a strong track record providing high-quality, evidence-based care to cancer patients. In order to accelerate discoveries that will further improve care for Veterans with cancer, the VA has partnered with the Center for Translational Data Science at the University of Chicago and the Open Commons Consortium to establish a data sharing platform, the Veterans Precision Oncology Data Commons (VPODC). The VPODC makes clinical, genomic, and imaging data from the VA available to the research community at large. In this paper, we detail our motivation for data sharing, describe the VPODC, and outline our collaboration model. By transforming VA data into a national resource for research in precision oncology, the VPODC seeks to foster innovation through collaboration and resource sharing that will ultimately lead to improved care for Veterans with cancer.

Feasibility and Acceptability in a Community-Partnered Implementation of CenteringParenting for Group Well-Child Care.

BACKGROUND: In a community-academic partnership, we implemented a group-based model for well-child care (WCC) (CenteringParenting) and conducted a pilot test for feasibility and acceptability among families at a federally qualified health center (FQHC). METHODS: The FQHC implemented CenteringParenting for all WCC visits in the first year of life, starting at the 2-week visit. Over a 14-month time period, parents from each new CenteringParenting group were enrolled into the study. Baseline data were collected at enrollment (infant age < 31 days) and again at a 6-month follow-up survey. Main outcomes were feasibility and acceptability of CenteringParenting; we also collected exploratory measures (parent experiences of care, utilization, self-efficacy, and social support). RESULTS: Of the 40 parent-infant dyads enrolled in the pilot, 28 CenteringParenting participants completed the 6-month follow-up assessment. The majority of infants were Latino, black, or "other" race/ethnicity; over 90% were Medicaid insured. Of the 28 CenteringParenting participants who completed the 6-month follow-up, 25 completed all visits between ages 2 weeks and 6 months in the CenteringParenting group. Of the CenteringParenting participants, 97% to 100% reported having adequate time with their provider and sufficient patient education and having their needs met at visits; most reported feeling comfortable at the group visit, and all reported wanting to continue CenteringParenting for their WCC. CenteringParenting participants' mean scores on exploratory measures demonstrated positive experiences of care, overall satisfaction of care, confidence in parenting, and parental social support. CONCLUSIONS: A community-academic partnership implemented CenteringParenting; the intervention was acceptable and feasible for a minority, low-income population. We highlight key challenges of implementation.

Valproic Acid and topiramate induced hyperammonemic encephalopathy in a patient with normal serum carnitine.

A 17-year-old female developed hyperammonemic encephalopathy 2 weeks after valproic acid (VPA), 500 mg twice a day, was added to her regimen of topiramate (TPM), 200 mg twice a day. She presented to the emergency department (ED) with altered mental status, hypotension, bradycardia, and lethargy. Laboratory analysis showed mild non-anion gap hyperchloremic acidosis, serum VPA concentration of 86 mg/L, and urine drug screen result that was positive for marijuana. She was admitted to the pediatric intensive care unit for persistent symptoms, prolonged QTc, and medical history. Blood ammonia concentrations were obtained because of her persistent altered mental status, initially 94 µmol/L and a peak of 252 µmol/L. A serum carnitine profile was obtained at the time of hyperammonemia and was found to be normal (results were available postdischarge). VPA and TPM were discontinued on day 1 and day 2, respectively, as the patient's blood ammonia concentration remained elevated. On day 3, her mental status had returned to baseline, and blood ammonia concentrations trended downward; by day 4 her blood ammonia concentration was 23 µmol/L. VPA has been associated with numerous side effects including hyperammonemia and encephalopathy. Recently, drug interactions with TPM and VPA have been reported; however, serum carnitine concentrations have not been available. We discuss the possible mechanisms that VPA and TPM may affect serum ammonia and carnitine concentrations and the use of levocarnitine for patients or treating toxicity.