Exercise provides protection against myocardial ischemia-reperfusion (IR) injury. Understanding the mechanisms of this protection may lead to new interventions for the prevention and/or treatment of heart disease. Although presently these mechanisms are not well understood, reports suggest that manganese superoxide dismutase (MnSOD) and calpain may be critical mediators of this protection. We hypothesized that an exercise-induced increase in MnSOD would provide cardioprotection by attenuating IR-induced oxidative modification to critical Ca(2+)-handling proteins, thereby decreasing calpain-mediated cleavage of these and other proteins attenuating cardiomyocyte death. After IR, myocardial apoptosis and infarct size were significantly reduced in hearts of exercised animals compared with sedentary controls. In addition, exercise prevented IR-induced calpain activation as well as the oxidative modification and calpain-mediated degradation of myocardial Ca(2+)-handling proteins (L-type Ca(2+) channels, phospholamban, and sarcoplasmic/endoplasmic reticulum calcium ATPase). Further, IR-induced activation of proapoptotic proteins was attenuated in exercised animals. Importantly, prevention of the exercise-induced increase in MnSOD activity via antisense oligonucleotides greatly attenuated the cardioprotection conferred by exercise. These results suggest that MnSOD provides cardioprotection by attenuating IR-induced oxidation and calpain-mediated degradation of myocardial Ca(2+)-handling proteins, thereby preventing myocardial apoptosis and necrosis.
Study Objectives We compared resident physician work hours and sleep in a multicenter clustered-randomized crossover clinical trial that randomized resident physicians to an Extended Duration Work Roster (EDWR) with extended-duration (≥24 hr) shifts or a Rapidly Cycling Work Roster (RCWR), in which scheduled shift lengths were limited to 16 or fewer consecutive hours. Methods Three hundred two resident physicians were enrolled and completed 370 1 month pediatric intensive care unit rotations in six US academic medical centers. Sleep was objectively estimated with wrist-worn actigraphs. Work hours and subjective sleep data were collected via daily electronic diary. Results Resident physicians worked fewer total hours per week during the RCWR compared with the EDWR (61.9 ± 4.8 versus 68.4 ± 7.4, respectively; p < 0.0001). During the RCWR, 73% of work hours occurred within shifts of ≤16 consecutive hours. In contrast, during the EDWR, 38% of work hours occurred on shifts of ≤16 consecutive hours. Resident physicians obtained significantly more sleep per week on the RCWR (52.9 ± 6.0 hr) compared with the EDWR (49.1 ± 5.8 hr, p < 0.0001). The percentage of 24 hr intervals with less than 4 hr of actigraphically measured sleep was 9% on the RCWR and 25% on the EDWR (p < 0.0001). Conclusions RCWRs were effective in reducing weekly work hours and the occurrence of >16 consecutive hour shifts, and improving sleep duration of resident physicians. Although inclusion of the six operational healthcare sites increases the generalizability of these findings, there was heterogeneity in schedule implementation. Additional research is needed to optimize scheduling practices allowing for sufficient sleep prior to all work shifts. Clinical Trial: Multicenter Clinical Trial of Limiting Resident Work Hours on ICU Patient Safety (ROSTERS), https://clinicaltrials.gov/ct2/show/NCT02134847
Objectives Juvenile onset recurrent respiratory papillomatosis (JORRP) can cause severe or disseminated disease. Surgical treatment may be inadequate. Systemic bevacizumab has shown initial success for severe JORRP. The objective of this systematic review was to assess usage, effectiveness, and safety of this treatment. Methods We searched PubMed, Embase, and Web of Science for studies of humans with JORRP treated with systemic bevacizumab. Two researchers independently reviewed the studies to determine inclusion and aggregate data on patient characteristics, dosing protocols, treatment response, adverse events, and level of evidence. Results Of 80 identified articles, 12 studies were included detailing 20 distinct cases. At a mean age of 12.8 years (range = 1–43 years) patients received initial dosing of 5 to 10 mg/kg of bevacizumab followed by ongoing doses at a mean 3‐week intervals (range = 2–5 weeks). All patients had clinically significant disease reduction with reduced need for surgery. Six patients (30%) had complete response in at least one involved anatomic site. Eleven (55%) required no surgery after initiating treatment. There was recurrence in all four patients whose treatment was stopped, but had rapid improvement with treatment resumption. Six (30%) experienced mild or moderate adverse events. Conclusions Marked improvement in severe JORRP has been reported from systemic bevacizumab. Treatment protocols vary, and treatment discontinuation was not feasible in any reported patient. Based on currently available data, systemic bevacizumab can be considered for severe JORRP as it appears to be well tolerated and effective. A clinical trial could enhance the understanding of its safety and efficacy for this indication. Laryngoscope, 131:1138–1146, 2021
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