Evaluation of surgical educational videos available for third year medical students.

Objectives: In this study we evaluated 40, top recommended, laparoscopic appendectomy and laparoscopic cholecystectomy videos located on public domain websites using eight criteria created by a panel of third year medical students and general surgeons. We hypothesized that there is a lack of quality, thorough educational laparoscopic surgical videos appropriate for third year medical students to review in preparation for the Surgery rotation.Methods: Utilizing a panel, which included four third year medical students and two general surgeons, we created an 'ideal medical student educational video checklist.' This checklist included 8 vital criteria. We selected 40, top recommended, videos available on YouTube and Google Video search engines, using 'laparoscopic cholecystectomy' and 'laparoscopic appendectomy' as key terms. Each video was evaluated by four third year medical students individually, using a binary system 'meets' or 'does not meet' each criterion. Individual scores were averaged, producing a single score for each video.Results: 0/40 (0%) of the videos met all eight of the criteria. 26/40 (65%) of the videos did not meet half of the criteria. The top performing videos 7/40 (17%) only met 5/8 criteria. Conclusions: We identified a lack of quality and thorough educational surgical videos appropriate for third year medical students and a need for improved online video based instruction. Our checklist can be utilized as a guide for anyone creating surgical videos for medical student education in the future.

Temporal integration of mitochondrial stress signals by the PINK1:Parkin pathway.

BACKGROUND: The PINK1:Parkin pathway regulates the autophagic removal of damaged and dysfunctional mitochondria. While the response of this pathway to complete loss of ΔΨm, as caused by high concentrations of mitochondrial ionophores, has been well characterized, it remains unclear how the pathway makes coherent decisions about whether to keep or purge mitochondria in situations where ΔΨm is only partially lost or exhibits fluctuations, as has been observed in response to certain types of cellular stress. RESULTS: To investigate the responses of the PINK1:Parkin pathway to mitochondrial insults of different magnitude and duration, controlled titration of the mitochondrial protonophore, CCCP, was used to manipulate ΔΨm in live cells, and the dynamics of PINK1 and Parkin recruitment was measured by fluorescence microscopy. In contrast to the stable accumulation of PINK1 and Parkin seen at completely depolarized mitochondria, partial depolarization produced a transient pulse of PINK1 stabilization and rapid loss, which was driven by small fluctuations in ΔΨm. As the rate of Parkin dissociation from the mitochondria and phospho-polyubiquitin chain removal was comparatively slow, repetitive pulses of PINK1 were able to drive a slow step-wise accumulation of Parkin and phospho-polyubiquitin leading to deferred mitophagy. CONCLUSION: These data suggest that the PINK1:Parkin mitophagy pathway is able to exhibit distinct dynamic responses to complete and partial mitochondrial depolarization. In this way, the pathway is able to differentiate between irretrievably damaged mitochondria and those showing signs of dysfunction, promoting either rapid or delayed autophagy, respectively.