Complex I-Associated Hydrogen Peroxide Production Is Decreased and Electron Transport Chain Enzyme Activities Are Altered in n-3 Enriched fat-1 Mice

The polyunsaturated nature of n-3 fatty acids makes them prone to oxidative damage. However, it is not clear if n-3 fatty acids are simply a passive site for oxidative attack or if they also modulate mitochondrial reactive oxygen species (ROS) production. The present study used fat-1 transgenic mice, that are capable of synthesizing n-3 fatty acids, to investigate the influence of increases in n-3 fatty acids and resultant decreases in the n-6∶n-3 ratio on liver mitochondrial H2O2 production and electron transport chain (ETC) activity. There was an increase in n-3 fatty acids and a decrease in the n-6∶n-3 ratio in liver mitochondria from the fat-1 compared to control mice. This change was largely due to alterations in the fatty acid composition of phosphatidylcholine and phosphatidylethanolamine, with only a small percentage of fatty acids in cardiolipin being altered in the fat-1 animals. The lipid changes in the fat-1 mice were associated with a decrease (p<0.05) in the activity of ETC complex I and increases (p<0.05) in the activities of complexes III and IV. Mitochondrial H2O2 production with either succinate or succinate/glutamate/malate substrates was also decreased (p<0.05) in the fat-1 mice. This change in H2O2 production was due to a decrease in ROS production from ETC complex I in the fat-1 animals. These results indicate that the fatty acid changes in fat-1 liver mitochondria may at least partially oppose oxidative stress by limiting ROS production from ETC complex I

Examining colorectal cancer survivors’ surveillance patterns and experiences of care: a SEER-CAHPS study

PurposeWe examined associations between experiences of care and adherence to surveillance guidelines among Medicare Fee-For-Service beneficiaries with colorectal cancer (CRC).MethodsUsing linked data from the National Cancer Institute's Surveillance, Epidemiology, and End results (SEER) cancer registry program and the Medicare Consumer Assessment of Healthcare Providers and Systems (CAHPS®) patient experience surveys (SEER-CAHPS), we identified local/regional CRC survivors diagnosed in 1999-2009 aged 65+, who underwent surgical resection and completed a CAHPS survey &lt;36 months of diagnosis. Adherence for a 3-year observation period was defined as receiving a colonoscopy; ≥2 carcinoembryonic antigen (CEA) tests; and each year had ≥2 office visits and ≥1 computerized tomography test.ResultsMany of the 314 participants reported ratings of a 9 or 10 out of 10 for overall care (55.4%), personal doctor (58.6%), health plan (59.6%), and specialist doctor (47.0%). Adherence to post-resection surveillance was 76.1% for office visits, 36.9% for CEA testing, 48.1% for colonoscopy, and 10.3% for CT Imaging. Overall, 37.9% of the sample were categorized as non-adherent (adhering to ≤1 surveillance guideline). In multivariable models, ratings of personal doctor and specialist doctor were positively associated with adherence to office visits, and ratings of personal doctor were associated with adherence overall.ConclusionsFindings point to the potentially important role of patient-provider relationships in adherence to office visits for CRC surveillance. As adherence may increase survival among CRC survivors, further investigation is needed to identify specific components of this relationship that impact office visit adherence, and other potentially modifiable drivers of surveillance guidelines