Cost-Consequences Analysis of Increased Utilization of Triple-Chamber-Bag Parenteral Nutrition in Preterm Neonates in Seven European Countries.

The safety of parenteral nutrition (PN) remains a concern in preterm neonates, impacting clinical outcomes and health-care-resource use and costs. This cost-consequence analysis assessed national-level impacts of a 10-percentage point increase in use of industry-prepared three-chamber bags (3CBs) on clinical outcomes, healthcare resources, and hospital budgets across seven European countries. A ten-percentage-point 3CB use-increase model was developed for Belgium, France, Germany, Italy, Portugal, Spain, and the UK. The cost-consequence analysis estimated the impact on compounding error harm and bloodstream infection (BSI) rates, staff time, and annual hospital budget. Of 265,000 (52%) preterm neonates, 133,000 (52%) were estimated to require PN. Baseline compounding methods were estimated as 43% pharmacy manual, 16% pharmacy automated, 22% ward, 9% outsourced, 3% industry provided non-3CBs, and 7% 3CBs. A modeled increased 3CB use would change these values to 39%, 15%, 18%, 9%, 3%, and 17%, respectively. Modeled consequences included -11.6% for harm due to compounding errors and -2.7% for BSIs. Labor time saved would equate to 41 specialized nurses, 29 senior pharmacists, 26 pharmacy assistants, and 22 senior pediatricians working full time. Budget impact would be a €8,960,601 (3.4%) fall from €260,329,814 to €251,369,212. Even a small increase in the use of 3CBs in preterm neonates could substantially improve neonatal clinical outcomes, and provide notable resource and cost savings to hospitals.

The calcium sensor Copine-6 regulates spine structural plasticity and learning and memory.

Hippocampal long-term potentiation (LTP) represents the cellular response of excitatory synapses to specific patterns of high neuronal activity and is required for learning and memory. Here we identify a mechanism that requires the calcium-binding protein Copine-6 to translate the initial calcium signals into changes in spine structure. We show that Copine-6 is recruited from the cytosol of dendrites to postsynaptic spine membranes by calcium transients that precede LTP. Cpne6 knockout mice are deficient in hippocampal LTP, learning and memory. Hippocampal neurons from Cpne6 knockouts lack spine structural plasticity as do wild-type neurons that express a Copine-6 calcium mutant. The function of Copine-6 is based on its binding, activating and recruiting the Rho GTPase Rac1 to cell membranes. Consistent with this function, the LTP deficit of Cpne6 knockout mice is rescued by the actin stabilizer jasplakinolide. These data show that Copine-6 links activity-triggered calcium signals to spine structural plasticity necessary for learning and memory.

Sec24- and ARFGAP1-dependent trafficking of GABA transporter-1 is a prerequisite for correct axonal targeting.

The GABA transporter-1 (GAT1) is a prototypical protein of the synaptic specialization. Export of GAT1 from the endoplasmic reticulum (ER) is contingent on its interaction with the COPII (coatomer protein-II) coat subunit Sec24D. Here we show that silencing all four Sec24 isoforms strongly inhibits transport of GAT1 to the cell surface. In contrast, transport of GAT1-RL/AS, a mutant that is deficient in Sec24D recruitment, was not inhibited, suggesting a nonconventional, COPII-independent pathway. However, ARFGAP1 bound directly to the C terminus of both GAT1-RL/AS and wild-type GAT1. Surface expression of GAT1-RL/AS involved ARFGAP1. GAT1-RL/AS appeared to bypass the ER-Golgi-intermediate compartment, but its pathway to the plasma membrane still involved passage through the Golgi. Thus, the GAT1-RL/AS mutant allowed to test whether COPII-dependent ER-export is required for correct sorting of GAT1 to the axon terminal in neuronal cells. In contrast to wild-type GAT1, GAT1-RL/AS failed to be specifically enriched at the tip of neurite extensions of CAD.a cells (a neuroblastoma cell line that can be differentiated into a neuron-like phenotype) and in the axon terminals of hippocampal neurons. These findings indicate that correct sorting to the axon is contingent on ER export via the COPII machinery and passage through the ER-Golgi-intermediate compartment.

Signal-dependent export of GABA transporter 1 from the ER-Golgi intermediate compartment is specified by a C-terminal motif.

The C-terminus of GABA transporter 1 (GAT1, SLC6A1) is required for trafficking of the protein through the secretory pathway to reach its final destination, i.e. the rim of the synaptic specialization. We identified a motif of three hydrophobic residues (569VMI571) that was required for export of GAT1 from the ER-Golgi intermediate compartment (ERGIC). This conclusion was based on the following observations: (i) GAT1-SSS, the mutant in which 569VMI571 was replaced by serine residues, was exported from the ER in a COPII-dependent manner but accumulated in punctate structures and failed to reach the Golgi; (ii) under appropriate conditions (imposing a block at 15 degrees C, disruption of COPI), these structures also contained ERGIC53; (iii) the punctae were part of a dynamic compartment, because it was accessible to a second anterograde cargo [the temperature-sensitive variant of vesicular stomatitis virus G protein (VSV-G)] and because GAT1-SSS could be retrieved from the punctate structures by addition of a KKxx-based retrieval motif, which supported retrograde transport to the ER. To the best of our knowledge, the VMI-motif of GAT1 provides the first example of a cargo-based motif that specifies export from the ERGIC.