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Aim: The Bleeding Control Basic (BCon) course was developed by the American College of Surgeons to teach laypeople and health-care providers (HCPs) how to stop life-threatening bleeding. The first BCon course in Japan was held for HCPs in July 2018. Our study aimed to evaluate the utility of the course, the satisfaction and confidence level of the HCPs that participated, and their experience with using vascular tourniquets., Method: The BCon participants were asked to complete a survey after the BCon courses from December 2018 to December 2019. These participants included different types of HCPs (physicians, nurses, and emergency medical technicians). After the course, the participants were asked to evaluate: (i) the perceived utility of the course, (ii) their satisfaction with the course, (iii) their confidence in the techniques that they learned in the course, (iv) their experience of using tourniquets in eight specific areas using a 10-point Likert scale., Results: A total of 163 HCPs, including 108 physicians, 27 nurses, and 28 emergency medical technicians completed the BCon course. The respondents rated the course highly, showing an average value of approximately 9 for each item for perceived utility, satisfaction, confidence, and experience in using tourniquets. In particular, nurses rated the overall activity more highly than physicians ( P  < 0.05)., Conclusion: The BCon course and tourniquets were well-received by all types of HCPs in Japan., Competing Interests: Approval of the research protocol: The Institutional Review Board at Tokyo Medical and Dental University provided approval (M2019‐096). Informed consent: Based on the opt‐out approach, we disclosed information about this study and excluded data when the patient declined to participate directly or via proxy. Registry and registration no. of the study/trial: N/A. Animal studies: N/A. Conflict of interest: The authors declare no conflict of interest., (© 2021 The Authors. Acute Medicine & Surgery published by John Wiley & Sons Australia, Ltd on behalf of Japanese Association for Acute Medicine.)

Repair of DNA double-strand breaks (DSBs) protects cells and organisms, as well as their genome integrity. Since DSB repair occurs in the context of chromatin, chromatin must be modified to prevent it from inhibiting DSB repair. Evidence supports the role of histone modifications and ATP-dependent chromatin remodeling in repair and signaling of chromosome DSBs. The key questions are, then, what the nature of chromatin altered by DSBs is and how remodeling of chromatin facilitates DSB repair. Here we report a chromatin alteration caused by a single HO endonuclease-generated DSB at the Saccharomyces cerevisiae MAT locus. The break induces rapid nucleosome migration to form histone-free DNA of a few hundred base pairs immediately adjacent to the break. The DSB-induced nucleosome repositioning appears independent of end processing, since it still occurs when the 5'-to-3' degradation of the DNA end is markedly reduced. The tetracycline-controlled depletion of Sth1, the ATPase of RSC, or deletion of RSC2 severely reduces chromatin remodeling and loading of Mre11 and Yku proteins at the DSB. Depletion of Sth1 also reduces phosphorylation of H2A, processing, and joining of DSBs. We propose that RSC-mediated chromatin remodeling at the DSB prepares chromatin to allow repair machinery to access the break and is vital for efficient DSB repair.

Repair of chromosome double-strand breaks (DSBs) is central to cell survival and genome integrity. Nonhomologous end joining (NHEJ) is the major cellular repair pathway that eliminates chromosome DSBs. Here we report our genetic screen that identified Rsc8 and Rsc30, subunits of the Saccharomyces cerevisiae chromatin remodeling complex RSC, as novel NHEJ factors. Deletion of RSC30 gene or the C-terminal truncation of RSC8 impairs NHEJ of a chromosome DSB created by HO endonuclease in vivo. rsc30Delta maintains a robust level of homologous recombination and the damage-induced cell cycle checkpoints. By chromatin immunoprecipitation, we show recruitment of RSC to a chromosome DSB with kinetics congruent with its involvement in NHEJ. Recruitment of RSC to a DSB depends on Mre11, Rsc30, and yKu70 proteins. Rsc1p and Rsc2p, two other RSC subunits, physically interact with yKu80p and Mre11p. The interaction of Rsc1p with Mre11p appears to be vital for survival from genotoxic stress. These results suggest that chromatin remodeling by RSC is important for NHEJ.