The processing of amyloid precursor protein (APP) to A␤ is an important event in the pathogenesis of Alzheimer's disease, but the physiological function of APP is not well understood. Our previous work has shown that APP processing and A␤ production are regulated by the extracellular matrix protein Reelin. In the present study, we examined whether Reelin interacts with APP, and the functional consequences of that interaction in vitro. Using coimmunoprecipitation, we found that Reelin interacted with APP through the central domain of Reelin (repeats 3-6) and the E1 extracellular domain of APP. Reelin increased cell surface levels of APP and decreased endocytosis of APP in hippocampal neurons in vitro. In vivo, Reelin levels were increased in brains of APP knock-out mice and decreased in APP-overexpressing mice. RNA interference knockdown of APP decreased neurite outgrowth in vitro and prevented Reelin from increasing neurite outgrowth. Knock-out of APP or Reelin decreased dendritic arborization in cortical neurons in vivo, and APP overexpression increased dendritic arborization. APP and Reelin have previously been shown to promote neurite outgrowth through interactions with integrins. We confirmed that APP interacted with ␣3␤1 integrin, and ␣3␤1 integrin altered APP trafficking and processing. Addition of an ␣3␤1 integrin antibody prevented APP and Reelin-induced neurite outgrowth. These findings demonstrate that Reelin interacts with APP, potentially having important effects on neurite development.

Aim:To examine the relationships among nurse staffing, nurses prioritization of nursing activities, missed care, quality of nursing care, and nurse outcomes.Background: Inadequate staffing is associated with increased missed care, which threatens the quality of care and nurse outcomes. Methods:The study sample included 2114 staff nurses from 156 medical or surgical units of 49 general hospitals who had participated in a cross-sectional survey conducted in 2015. Nurse staffing was measured using the patient-to-nurse ratio and perceived staffing adequacy. The Missed Nursing Care Survey was used to measure how frequently nurses had missed each of 24 activities. Multilevel regression analyses were employed to examine the relationships among variables. Results:The prevalence of missed care differed by nursing activity. Poorer staffing was associated with an increased number of missed activities. A higher number of missed activities and poorer staffing were associated with poorer patient safety, quality of nursing care and job satisfaction, and a higher intent to leave. Nurses gave the highest priority to focused patient reassessments, timely medications, and patient teaching, under hypothetical conditions of improved staffing. Conclusion:Adequate staffing is required to reduce missed care and to improve quality of care and nurse outcomes. K E Y W O R D SJob satisfaction, missed nursing care, nurse staffing, quality, safety SUMMARY STATEMENTWhat is already known about this topic?• Low nurse staffing is associated with a high prevalence of missed care, which has negative effects on patient and nurse outcomes.• Nurses are known to prioritize their nursing tasks in the face of time scarcity. However, insufficient studies have investigated how nurses prioritize nursing care and, further, how their prioritization would be modified if nurse staffing were to improve.What is already known about this topic?• Poorer perceptions of staffing adequacy and the patient-to-RN ratio had a significant association with a higher number of missed nursing activities.

Purpose: Array comparative genomic hybridization is rapidly becoming an integral part of cytogenetic diagnostics. We report the design, validation, and clinical utility of an oligonucleotide array which combines genome-wide coverage with targeted enhancement at known clinically relevant regions. Methods: Probes were placed every 75 kb across the entire euchromatic genome to establish a chromosomal "backbone" with a resolution of ϳ500 kb, which is increased to ϳ50 kb in targeted regions. Results: For validation, 30 samples showed 100% concordance with previous G-banding and/or fluorescence in situ hybridization results. Prospective array analysis of 211 clinical samples identified 33 (15.6%) cases with clinically significant abnormalities. Of these, 23 (10.9%) were detected by the "targeted" coverage and 10 (4.7%) by the genome-wide coverage (average size of 3.7 Mb). All abnormalities were verified by fluorescence in situ hybridization, using commercially available or homebrew probes using the 32K bacterial artificial chromosome set. Four

We hypothesized that plasma-based EGFR mutation analysis for NSCLC may be feasible for monitoring treatment response to EGFR TKIs and also predict drug resistance. Clinically relevant mutations including exon 19 deletion (ex19del), L858R and T790M were analyzed using droplet digital PCR (ddPCR) in longitudinally collected plasma samples (n = 367) from 81 NSCLC patients treated with EGFR TKI. Of a total 58 baseline cell-free DNA (cfDNA) samples available for ddPCR analysis, 43 (74.1%) had the same mutation in the matched tumors (clinical sensitivity: 70.8% [17/24] for L858R and 76.5% [26/34] for ex19del). The concordance rates of plasma with tissue-based results of EGFR mutations were 87.9% for L858R and 86.2% for ex19del. All 40 patients who were detected EGFR mutations at baseline showed a dramatic decrease of mutant copies (>50%) in plasma during the first two months after treatment. Median progression-free survival (PFS) was 10.1 months for patients with undetectable EGFR v 6.3 months for detectable EGFR mutations in blood after two-month treatment (HR 3.88, 95% CI 1.48-10.19, P = 0.006). We observed emerging resistance with early detection of T790M as a secondary mutation in 14 (28.6%) of 49 patients. Plasma-based EGFR mutation analysis using ddPCR can monitor treatment response to EGFR TKIs and can lead to early detection of EGFR TKIs resistance. Further studies confirming clinical implications of EGFR mutation in plasma are warranted to guide optimal therapeutic strategies upon knowledge of treatment response and resistance.

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Summary Ras and Rap small GTPases are important for synaptic plasticity and memory. However, their roles in homeostatic plasticity are unknown. Here, we report that polo-like kinase 2 (Plk2), a homeostatic suppressor of overexcitation, governs the activity of Ras and Rap via coordination of their regulatory proteins. Plk2 directs elimination of Ras activator RasGRF1 and Rap inhibitor SPAR via phosphorylation-dependent ubiquitin-proteasome degradation. Conversely, Plk2 phosphorylation stimulates Ras inhibitor SynGAP and Rap activator PDZGEF1. These Ras/Rap regulators perform complementary functions to downregulate dendritic spines and AMPA receptors following elevated activity, and their collective regulation by Plk2 profoundly stimulates Rap and suppresses Ras. Furthermore, perturbation of Plk2 disrupts Ras and Rap signaling, prevents homeostatic shrinkage and loss of dendritic spines, and impairs proper memory formation. Our study demonstrates a critical role of Plk2 in the synchronized tuning of Ras and Rap, and underscores the functional importance of this regulation in homeostatic synaptic plasticity.

The amyloid precursor protein (APP) is cleaved to produce the Alzheimer disease-associated peptide A␤, but the normal functions of uncleaved APP in the brain are unknown. We found that APP was present in the postsynaptic density of central excitatory synapses and coimmunoprecipitated with N-methyl-Daspartate receptors (NMDARs). The presence of APP in the postsynaptic density was supported by the observation that NMDARs regulated trafficking and processing of APP; overexpression of the NR1 subunit increased surface levels of APP, whereas activation of NMDARs decreased surface APP and promoted production of A␤. We transfected APP or APP RNA interference into primary neurons and used electrophysiological techniques to explore the effects of APP on postsynaptic function. Reduction of APP decreased (and overexpression of APP increased) NMDAR whole cell current density and peak amplitude of spontaneous miniature excitatory postsynaptic currents. The increase in NMDAR current by APP was due to specific recruitment of additional NR2B-containing receptors. Consistent with these findings, immunohistochemical experiments demonstrated that APP increased the surface levels and decreased internalization of NR2B subunits. These results demonstrate a novel physiological role of postsynaptic APP in enhancing NMDAR function.Alzheimer disease (AD) 5 is an age-related neurodegenerative disease characterized by the progressive loss of synapses and neurons and by the formation of amyloid plaques and neurofibrillary tangles. Amyloid plaques are composed predominantly of the A␤ peptide, a 40-or 42-amino acid cleavage product of amyloid precursor protein (APP). APP is a transmembrane protein of unknown function that undergoes extracellular cleavage by one of two activities, ␣-or ␤-secretase, resulting in the formation of large N-terminal extracellular fragments of secreted APP and smaller, membrane-bound C-terminal fragments. If the initial cleavage event occurs via ␤-secretase, then subsequent cleavage of the C-terminal fragment by ␥-secretase results in the production of A␤ (1).Clues to APP function may be gleaned from studies of its different cleavage products or isoforms. Soluble forms of APP have been found to be neurotrophic, and some splice variants have proteinase inhibitor activity (2). The APP intracellular domain may alter gene transcription in conjunction with cytoplasmic proteins (3). In addition, the A␤ peptide has been shown to inhibit glutamate receptor activity (4, 5). However, the function of full-length APP is undefined, and it is likely that full-length APP performs distinct roles from any its cleavage products. One recent study showed that mice lacking APP have impaired development of neuromuscular junctions (6), suggesting an important role for APP in maintaining active synapses. Understanding APP function in central neurons may provide valuable information in generating interventions against the generation of A␤ and thus AD pathogenesis and its accompanying memory loss.Further evidence for a synaptic function of A...

Glucocorticoids are among the most commonly used anti-inflammatory agents. Despite the enormous efforts in elucidating the glucocorticoid-mediated anti-inflammatory actions, how glucocorticoids tightly control overactive inflammatory response is not fully understood. Here we show that glucocorticoids suppress bacteria-induced inflammation by enhancing IRAK-M, a central negative regulator of Toll-like receptor signalling. The ability of glucocorticoids to suppress pulmonary inflammation induced by non-typeable Haemophilus influenzae is significantly attenuated in IRAK-M-deficient mice. Glucocorticoids improve the survival rate after a lethal non-typeable Haemophilus influenzae infection in wild-type mice, but not in IRAK-M-deficient mice. Moreover, we show that glucocorticoids and non-typeable Haemophilus influenzae synergistically upregulate IRAK-M expression via mutually and synergistically enhancing p65 and glucocorticoid receptor binding to the IRAK-M promoter. Together, our studies unveil a mechanism by which glucocorticoids tightly control the inflammatory response and host defense via the induction of IRAK-M and may lead to further development of anti-inflammatory therapeutic strategies.