Long-Distance Axon Regeneration Promotes Recovery of Diaphragmatic Respiratory Function after Spinal Cord Injury.

Compromise in inspiratory breathing following cervical spinal cord injury (SCI) is caused by damage to descending bulbospinal axons originating in the rostral ventral respiratory group (rVRG) and consequent denervation and silencing of phrenic motor neurons (PhMNs) that directly control diaphragm activation. In a rat model of high-cervical hemisection SCI, we performed systemic administration of an antagonist peptide directed against phosphatase and tensin homolog (PTEN), a central inhibitor of neuron-intrinsic axon growth potential. PTEN antagonist peptide (PAP4) robustly restored diaphragm function, as determined with electromyography (EMG) recordings in living SCI animals. PAP4 promoted substantial, long-distance regeneration of injured rVRG axons through the lesion and back toward PhMNs located throughout the C3-C5 spinal cord. These regrowing rVRG axons also formed putative excitatory synaptic connections with PhMNs, demonstrating reconnection of rVRG-PhMN-diaphragm circuitry. Lastly, re-lesion through the hemisection site completely ablated functional recovery induced by PAP4. Collectively, our findings demonstrate that axon regeneration in response to systemic PAP4 administration promoted recovery of diaphragmatic respiratory function after cervical SCI.

Colonoscopy utilization in rural areas by general surgeons: An analysis of the National Ambulatory Medical Care Survey.

BACKGROUND: One in three adults above 50 years old have not been screened for colorectal cancer as of 2013.1 Rural areas have even lower screening and have more general surgeons compared to gastroenterologists,2 offering surgeons as a reservoir for necessary services. METHODS: Public data from the 2006-2015 CDC National Ambulatory Medical Care Survey was analyzed using SAS. Number of colonoscopies performed by rural general surgeons, family medicine practitioners, and other specialties were compared to their urban counterparts. RESULTS: 21.91% of rural colonoscopies were performed by general surgeons, whereas 32.87% were performed by family medicine practitioners and 45.22% by other specialties including gastroenterologists. Rural general surgeons performed a greater percentage of annual rural colonoscopies than urban general surgeons (p < 0.05). CONCLUSION: General surgeons are fulfilling the need for colonoscopy in rural areas. Improvements to current colonoscopy training guidelines are imperative, especially for physicians who practice in rural areas.