Aging impairs mouse skeletal muscle macrophage polarization and muscle-specific abundance during recovery from disuse.

Impaired recovery of aged muscle following a disuse event is an unresolved issue facing the older adult population. Although investigations in young animals have suggested that rapid regrowth of skeletal muscle following a disuse event entails a coordinated involvement of skeletal muscle macrophages, this phenomenon has not yet been thoroughly tested as an explanation for impaired muscle recovery in aging. To examine this hypothesis, young (4-5 mo) and old (24-26 mo) male mice were examined as controls following 2 wk of hindlimb unloading (HU) and following 4 (RL4) and 7 (RL7) days of reloading after HU. Muscles were harvested to assess muscle weight, myofiber-specifc cross-sectional area, and skeletal muscle macrophages via immunofluorescence. Flow cytometry was used on gastrocnemius and soleus muscle (at RL4) single-cell suspensions to immunophenotype skeletal muscle macrophages. Our data demonstrated impaired muscle regrowth in aged compared with young mice following disuse, which was characterized by divergent muscle macrophage polarization patterns and muscle-specifc macrophage abundance. During reloading, young mice exhibited the classical increase in M1-like (MHC II+CD206-) macrophages that preceeded the increase in percentage of M2-like macrophages (MHC II-CD206+); however, old mice did not demonstrate this pattern. Also, at RL4, the soleus demonstrated reduced macrophage abundance with aging. Together, these data suggest that dysregulated macrophage phenotype patterns in aged muscle during recovery from disuse may be related to impaired muscle growth. Further investigation is needed to determine whether the dysregulated macrophage response in the old during regrowth from disuse is related to a reduced ability to recruit or activate specific immune cells.

Evaluation of a systematic methodology to detect in near real-time performance changes during electronic health record system implementations: a longitudinal study.

Introduction. Although Electronic Health Record (EHR) adoption has increased in the U.S., our understanding of how it affects health care organizations is still limited. Current literature has produced mixed-results due to the use of simple, non-standardized measurements and poor research designs. Methods. We propose the use of a systematic methodology that combines measures of quality, productivity and safety processes, tracked over time using an interrupted time-series design with multiple control sites. Results. Our methodology successfully detected performance changes during an EHR implementation on 17 (77%) outcomes, including a significant increase in Emergency Department length of stay immediately after go live by 0.19 hours [95%CI (0.12, 0.27), p<0.001], and an improvement in time to complete radiology tests, which significantly decreased per month by 0.19 minutes [95%CI (-0.26, -0.12), p<0.001]. Conclusion. The proposed methodology was able to detect several changes immediately after an EHR implementation and over time. The method is a promising and robust approach to assessing the impact of EHR implementations on a wide range of health care quality, productivity, and safety care processes.