SAPS 3 is not superior to SAPS 2 in cardiac surgery patients

Objectives. Cardiac surgery patients are excluded from SAPS2 but included in SAPS3. Neither score is evaluated for this exclusive population; however, they are used daily. We hypothesized that SAPS3 may be superior to SAPS2 in outcome prediction in cardiac surgery patients. Design. All consecutive patients undergoing cardiac surgery between January 2007 and December 2010 were included in our prospective study. Both models were tested with calibration and discrimination statistics. We compared the AUC of the ROC curves by DeLong's method and calculated OCC values. Results. A total of 5207 patients with mean age of 67.2 ± 10.9 years were admitted to the ICU. The mean length of ICU stay was 4.6 ± 7.0 days and the ICU mortality was 5.9%. The two tested models had acceptable discriminatory power (AUC: SAPS2: 0.777–0.875; SAPS3: 0.757–893). SAPS3 had a low AUC and poor calibration on admission day. SAPS2 had poor calibration on Days 1–6 and 8. Conclusions. Despite including cardiac surgery patients, SAPS3 was not superior to SAPS2 in our analysis. In this large cohort of ICU cardiac surgery patients, performance of both SAPS models was generally poor. In this subset of patients, neither scoring system is recommended.     

Catalase has a key role in protecting cells from the genotoxic effects of monomethylarsonous acid: A highly active metabolite of arsenic

Although it is widely known that arsenic‐contaminated drinking water causes many diseases, arsenic's exact mode of action (MOA) is not fully understood. Induction of oxidative stress has been proposed as an important key event in the toxic MOA of arsenic. The authors' studies are centered on identifying a reactive species involved in the genotoxicity of arsenic using a catalase (CAT) knockout mouse model that is impaired in its ability to breakdown hydrogen peroxide (H₂O₂). The authors assessed the induction of DNA damage using the Comet assay following exposure of mouse Cat^+/+ and Cat^?/? primary splenic lymphocytes to monomethylarsonous acid (MMA^III) to identify the potential role of H₂O₂ in mediating cellular effects of this metalloid. The results showed that the Cat^?/? lymphocytes are more susceptible to MMA^III than the Cat^+/+ lymphocytes by a small (1.5‐fold) but statistically significant difference. CAT activity assays demonstrated that liver tissue has approximately three times more CAT activity than lymphocytes. Therefore, Comet assays were performed on primary Cat^+/+, Cat^+/?, and Cat^?/? hepatocytes to determine if the Cat^?/? cells were more susceptible to MMA^III than lymphocytes. The results showed that the Cat^?/? hepatocytes exhibit higher levels of DNA strand breakage than the Cat^+/+ (approximately fivefold) and Cat^+/? (approximately twofold) hepatocytes exposed to MMA^III. Electron spin resonance using 5,5‐dimethyl‐1‐pyrroline‐N‐oxide as the spin‐trap agent detected the generation of ·OH via MMA^III when H₂O₂ was present. These experiments suggest that CAT is involved in protecting cells against the genotoxic effects of the ·OH generated by MMA^III. Environ. Mol. Mutagen. 54:317–326, 2013. © 2013 Wiley Periodicals, Inc.     

Retromode imaging: Review and perspectives

Retromode imaging with infrared lasers is a novel imaging method which has been made possible by the newly introduced confocal scanning laser ophthalmoscope. Retromode imaging uses a laterally deviated confocal aperture with a central stop, which creates a shadow and allows deep retinal and retinal pigment epithelium changes to be visualized as pseudo-3-dimensional images. Its clinical value coupled with its simple, rapid, and noninvasive nature is increasingly appreciated. The combination of retromode imaging with conventional imaging methods such as fundus photography, fluorescein angiography, and optical coherence tomography can help to precisely and comprehensively evaluate pathophysiologic features of retinal disorders. This review summarizes basic principles of imaging and retromode findings in various retinal disorders and is expected to guide future investigations of retromode imaging.