rhBMP-2-Conjugated Three-Dimensional-Printed Poly(L-lactide) Scaffold is an Effective Bone Substitute

BACKGROUND@#Bone growth factors, particularly bone morphogenic protein-2 (BMP-2), are required for effective treatment of significant bone loss. Despite the extensive development of bone substitutes, much remains to be desired for wider application in clinical settings. The currently available bone substitutes cannot sustain prolonged BMP-2 release and are inconvenient to use. In this study, we developed a ready-to-use bone substitute by sequential conjugation of BMP to a three-dimensional (3D) poly(L-lactide) (PLLA) scaffold using novel molecular adhesive materials that reduced the operation time and sustained prolonged BMP release. @*METHODS@#A 3D PLLA scaffold was printed and BMP-2 was conjugated with alginate-catechol and collagen. PLLA scaffolds were conjugated with different concentrations of BMP-2 and evaluated for bone regeneration in vitro and in vivo using a mouse calvarial model. The BMP-2 release kinetics were analyzed using ELISA. Histological analysis and microCT image analysis were performed to evaluate new bone formation. @*RESULTS@#The 3D structure of the PLLA scaffold had a pore size of 400 lm and grid thickness of 187–230 lm. BMP-2 was released in an initial burst, followed by a sustained release for 14 days. Released BMP-2 maintained osteoinductivity in vitro and in vivo. Micro-computed tomography and histological findings demonstrate that the PLLA scaffold conjugated with 2 lg/ml of BMP-2 induced optimal bone regeneration. @*CONCLUSION@#The 3D-printed PLLA scaffold conjugated with BMP-2 enhanced bone regeneration, demonstrating its potential as a novel bone substitute.

Fatty Acid Increases cAMP-dependent Lactate and MAO-B-dependent GABA Production in Mouse Astrocytes by Activating a G(αs) Protein-coupled Receptor

Medium-chain fatty acids (MCFAs) are mostly generated from dietary triglycerides and can penetrate the blood-brain barrier. Astrocytes in the brain use MCFAs as an alternative energy source. In addition, MCFAs have various regulatory and signaling functions in astrocytes. However, it is unclear how astrocytes sense and take up MCFAs. This study demonstrates that decanoic acid (DA; C10), a saturated MCFA and a ligand of G(αs) protein-coupled receptors (G(αs)-GPCRs), is a signaling molecule in energy metabolism in primary astrocytes. cAMP synthesis and lactate release were increased via a putative G(αs)-GPCR and transmembrane adenylyl cyclase upon short-term treatment with DA. By contrast, monoamine oxidase B-dependent gamma-aminobutyric acid (GABA) synthesis was increased in primary cortical and hypothalamic astrocytes upon long-term treatment with DA. Thus, astrocytes respond to DA by synthesizing cAMP and releasing lactate upon short-term treatment, and by synthesizing and releasing GABA upon long-term treatment, similar to reactive astrocytes. Our data suggest that astrocytes in the brain play crucial roles in lipid-sensing via GPCRs and modulate neuronal metabolism or activity by releasing lactate via astrocyte-neuron lactate shuttle or GABA to influence neighboring neurons.

Experience of Verbal Abuse, Emotional Response, and Ways to Deal with Verbal Abuse against Nurses in Hospital / 산업간호학회지

PURPOSE: This study tries to identify experience of verbal abuse, emotional response, and ways to deal with verbal abuse against nurses in hospitals. METHODS: This study was a descriptive research and conducted from April to July 2011. One hundred and seventeen nurses with over one-year experience in general wards were selected and evaluated. The data were analyzed using descriptive analysis, independent t-tests, and one-way ANOVA. RESULTS: The nurses' experience rate of verbal abuse during the entire period of work in hospitals was 98.3%. The majority of the nurses were verbally abused by patients (70.9%), followed by patients' relatives (65.8%), physicians (61.5%), and coworkers (58.1%). Overall negative emotional response score of nurses after verbal abuse was 38.82+/-8.28. Ways to deal with verbal abuse were as follows: suppression was 74.4%, complaining of an injustice to close people, 67.5%, and ignoring, 43.6%. CONCLUSION: Nurses have significantly been exposed to verbal abuse while working in hospitals. Therefore, hospital managers and nurse managers are required to inform other staff and visitors in hospitals the real condition of verbal abuse against nurses and provide a safe work environment by developing the report and disposal system of verbal abuse.