Low production of mitochondrial reactive oxygen species after anoxia and reoxygenation in turtle hearts.

Extremely anoxia-tolerant animals, such as freshwater turtles, survive anoxia and reoxygenation without sustaining tissue damage to their hearts. In contrast, for mammals, the ischemia-reperfusion (IR) injury that leads to tissue damage during a heart attack is initiated by a burst of superoxide (O2·-) production from the mitochondrial respiratory chain upon reperfusion of ischemic tissue. Whether turtles avoid oxidative tissue damage because of an absence of mitochondrial superoxide production upon reoxygenation, or because the turtle heart is particularly protected against this damage, is unclear. Here, we investigated whether there was an increase in mitochondrial O2·- production upon the reoxygenation of anoxic red-eared slider turtle hearts in vivo and in vitro. This was done by measuring the production of H2O2, the dismutation product of O2·-, using the mitochondria-targeted mass-spectrometric probe in vivo MitoB, while in parallel assessing changes in the metabolites driving mitochondrial O2·- production, succinate, ATP and ADP levels during anoxia, and H2O2 consumption and production rates of isolated heart mitochondria. We found that there was no excess production of in vivo H2O2 during 1 h of reoxygenation in turtles after 3 h anoxia at room temperature, suggesting that turtle hearts most likely do not suffer oxidative injury after anoxia because their mitochondria produce no excess O2·- upon reoxygenation. Instead, our data support the conclusion that both the low levels of succinate accumulation and the maintenance of ADP levels in the anoxic turtle heart are key factors in preventing the surge of O2·- production upon reoxygenation.

A quality improvement initiative to increase adult ECMO decision-making abilities in a perfusion education program: The use of 3D ECMO simulation.

INTRODUCTION: Adult and pediatric ECMO procedures have been increasingly established as conventional life-saving modalities in critical care services across the world. Since 2017, a multidisciplinary team of program advisors for our perfusion education program have aimed to increase cardiovascular perfusion (CVP) student ECMO exposure and improve clinical decision-making. In this QI intervention, the use of 3D computer-based simulation was assessed in establishing a standardized process to improve the diagnosis and treatment of adult ECMO complications among first year CVP students. METHODS: The Califia 3D Patient Simulator was incorporated into the curriculum for first year CVP students (n = 26) along with traditional lecture for the adult ECMO complication laboratory session. Pre-class knowledge assessments using de-identified polling software were compared to post-class assessments following the first assigned learning activity. Assessments from students that received simulation before lecture (SIM, n = 15) were compared to students receiving lecture before simulation (LEC, n = 11). User experience questionnaires (UEQ) consisting of 26 questions for six scales of simulation instruction were administered to measure the comprehensive impression of the student experience. RESULTS: Overall median [IQR] pre- and -post knowledge assessment scores were 74% [11] and 84% [11], respectively (p = 0.01). There were no significant differences in pre-class assessment scores between the SIM and LEC groups (74.0% and 74.0%, respectively, p = 0.959). The LEC group achieved higher median post-assessment scores than the SIM group (84% vs 79%, p = 0.032). Among the 26 UEQ survey scales, 23 were positively evaluated (>0.8), and three were a neutral evaluation (-0.8 to 0.8). Cronbach Alpha-Coefficients of >0.78 were measured for attractiveness, perspicuity, efficacy, and stimulation. The coefficient for dependability was 0.37. 25 (96.2%) students indicated that 3D simulation was beneficial to improving ECMO clinical decision-making. CONCLUSIONS: In this QI intervention, the implementation of computer-based 3D simulation following lecture was perceived by learners to help improve the diagnosis and treatment of ECMO-related complications.

What are we measuring? Comparison of household food security indicators in the Eastern Cape Province, South Africa.

The development of national food security information systems is constrained by a lack of guidance on which indicators to use. This paper compares food security indicators across two seasons (summer and winter) in one of the most deprived areas of the Eastern Cape province of South Africa. The results show that only anthropometric indicators are sensitive enough to differentiate levels of food insecurity. The lack of consistent classification across indicators means that surveys must use a combination of food consumption and experience of hunger measures backed up by anthropometric measures. Targeting interventions is difficult if the measures cannot be relied on. Further investigation is needed to identify a suite of appropriate indicators for a national information and surveillance system.