Polyacrylamide Bead Sensors for in vivo Quantification of Cell-Scale Stress in Zebrafish Development.

Mechanical stress exerted and experienced by cells during tissue morphogenesis and organ formation plays an important role in embryonic development. While techniques to quantify mechanical stresses in vitro are available, few methods exist for studying stresses in living organisms. Here, we describe and characterize cell-like polyacrylamide (PAAm) bead sensors with well-defined elastic properties and size for in vivo quantification of cell-scale stresses. The beads were injected into developing zebrafish embryos and their deformations were computationally analyzed to delineate spatio-temporal local acting stresses. With this computational analysis-based cell-scale stress sensing (COMPAX) we are able to detect pulsatile pressure propagation in the developing neural rod potentially originating from polarized midline cell divisions and continuous tissue flow. COMPAX is expected to provide novel spatio-temporal insight into developmental processes at the local tissue level and to facilitate quantitative investigation and a better understanding of morphogenetic processes.

Soft and flexible poly(ethylene glycol) nanotubes for local drug delivery.

Nanotubes are emerging as promising materials for healthcare applications but the selection of clinically relevant starting materials for their synthesis remains largely unexplored. Here we present, for the first time, the synthesis of poly(ethylene glycol) (PEG) based nanotubes via the photopolymerization of poly(ethylene glycol) diacrylate and other diacrylate derivatives within the pores of anodized aluminum oxide templates. Template-assisted synthesis allowed the manufacture of a diverse set of polymeric nanotubes with tunable physical characteristics including diameter (∼200-400 nm) and stiffness (405-902 kPa). PEG nanotubes were subjected to cytotoxicty assessment in cell lines and primary stem cells and showed excellent cytocompatability (IC50 > 120 µg ml-1). Nanotubes were readily drug loaded but released the majority of the drug over 5 days. Direct administration of drug loaded nanotubes to human orthotopic breast tumors substantially reduced tumor growth and metastasis and outperformed i.v. administration at the equivalent dose. Overall, this nanotube templating platform is emerging as a facile route for the manufacture of poly(ethylene glycol) nanotubes.

It all comes down to degrees. The QI process between two units.

Cold stress is potentially life-threatening to a 600-g neonate. The risk of cold stress is increased during the admission process, when a neonate is transferred from a labor and delivery suite to a patient care unit. At one perinatal center, staff nurses devised a quality improvement plan to assess and reduce the risk of cold stress to patients admitted to the neonatal intensive care unit.

Where does it hurt? An interdisciplinary approach to improving the quality of pain assessment and management in the neonatal intensive care unit.

Identifying a premature infant's response to noxious stimuli and knowing when it is appropriate to intervene are major issues for the caregiver. After completing a pilot study, the staff of a 42-bed neonatal intensive care unit targeted improved pain assessment and management for further analysis. Using a series of Plan, Do, Check, and Act cycles they designed a stepwise set of interventions that resulted in the improved assessment and management of the neonate in pain.

Increased cell-mediated cytotoxicity against beta-cells in streptozotocin-treated offspring of mother animals with gestational hyperglycaemia.

The offspring of mother animals with mild gestational hyperglycaemia exhibited basal hyperinsulinism, decreased glucose tolerance and increased susceptibility to streptozotocin diabetes. Following low-dose successive streptozotocin treatment a significantly increased spleen cell cytotoxicity against beta-cells was found in these animals as compared to the offspring of gestational normoglycaemic control mothers. Such increased cell-mediated cytotoxicity, considered as enhanced autoimmune reactivity, was positively correlated to blood glucose levels and negatively correlated to pancreatic insulin contents. Thus, hyperinsulinism, occurring during pre- and neonatal brain organization and produced by gestational hyperglycaemia, is a predisposing teratogenetic risk factor not only for the development of type II, but also of type I diabetes. Thus, it is comprehensible that the prevalence of type I diabetes in children could be decisively reduced by preventing gestational hyperglycaemia in their mothers (Dörner et al., 1985).