Injuries and illness of athletes at the Tokyo 2020 Olympic and Paralympic summer games visiting outside facilities.

This study aimed to identify the reasons for transferring athletes to local medical facilities during the Olympic and Paralympic Games. Data on 567 injuries and other illnesses of athletes treated at the on-site clinics were collected from the Tokyo 2020 Organizing Committee. Of these, 84 athletes who required outpatient care during the Games were registered for this survey. During the Olympic and Paralympic Games, 66 (8.3/1 000) and 18 (7.2/1 000) athletes, respectively, consulted external medical facilities. In the Olympic Games, the reasons for these visits included 48 cases (72.7%) of injuries, 13 (19.7%) cases of illnesses, and 5 (7.6%) cases of heat stroke illness (HSI). Of these patients, 56 (84.9%) were treated as outpatients and 10 (15.1%) were hospitalized, while three of these patients required hospitalization for > 7 days. On the other hand, in the Paralympics Games, there were 7 (38.8%) cases of injuries, 9 (50.0%) other illnesses, 1 (5.6%) case of HSI, and 1 (5.6%) other cases, of which 11 (61.1%) were treated as outpatients and 7 (38.9%) were hospitalized, but none was hospitalized for > 7 days. Injuries accounted for 70% of the total cases at the 2021 Olympic Games, but only three (0.05%) were severe cases that required hospitalization for more than 1 week. In contrast, in the Paralympic Games, other illnesses accounted for approximately half of the total cases. This study provides details on the extent of injuries and other illnesses that were transferred to outside facilities, which has not been documented in previous games.

Incidence and factor analysis for the heat-related illness on the Tokyo 2020 Olympic and Paralympic Games.

Introduction: Among the 43 venues of Tokyo 2020 Olympic Games (OG) and 33 venues of Paralympic Games (PG) were held, the heat island effect was highly expected to cause heat-related illnesses in the outdoor venues with maximum temperatures exceeding 35°C. However, the actual number of heat-related illness cases during the competition was lower than that was initially expected, and it was unclear under what conditions or environment-related heat illnesses occurred among athletes. Object: To clarify the cause and factors contributing to the occurrence of heat-related illness among athletes participating in the Tokyo 2020 Olympic and Paralympic Games. Method: This retrospective descriptive study included 15 820 athletes from 206 countries. From 21 July 2021 to 8 August 2021 for the Olympics, and from 24 August 2021 to 5 September 2021 for the Paralympics. The number of heat-related illness cases at each venue, the incidence rate for each event, gender, home continent, as well as the type of competition, environmental factors (such as venue, time, location and wet-bulb globe temperature (WBGT)), treatment factor and the type of competition were analysed. Results: More number of heat-related illnesses among athletes occurred at the OG (n=110, 76.3%) than at the PG (n=36, 23.7%). A total of 100 cases (100%) at the OG and 31 cases (86.1%) at the PG occurred at the outdoors venues. In the OG, a total of 50 cases (57.9%) occurred during the competition of marathon running and race walking at Sapporo Odori Park. Six of those, were diagnosed with exertional heat illness and treated with cold water immersion (CWI) at OG and one case at PG. Another 20 cases occurred in athletics (track and field) competitions at Tokyo National Olympic Stadium. In total, 10 cases (10.0%) were diagnosed with severe heat illness in the OG and 3 cases (8.3%) in the PG. Ten cases were transferred to outside medical facilities for further treatment, but no case has been hospitalised due to severe condition. In the factor analysis, venue zone, outdoor game, high WBGT (<28°C) and endurance sports have been found to have a higher risk of moderate and severe heat-related illness (p<0.05). The incidence rate and severity could be attenuated by proper heat-related illness treatment (CWI, ice towel, cold IV transfusion and oral hydration) reduced the severity of the illness, providing summer hot environment sports. Conclusion: The Tokyo 2020 Olympic and Paralympic summer games were held. Contrary to expectations, we calculated that about 1 in 100 Olympic athletes suffered heat-related illness. We believe this was due to the risk reduction of heat-related illness, such as adequate prevention and proper treatment. Our experience in avoiding heat-related illness will provide valuable data for future Olympic summer Games.

Acute in-competition medical care at the Tokyo 2020 Olympics: a retrospective analysis.

OBJECTIVE: To analyse injuries and illnesses during the 2020 Tokyo Olympic Summer Games. METHODS: This retrospective descriptive study included 11 420 athletes from 206 National Olympic Committees and 312 883 non-athletes. Incidences of injuries and illnesses during the competition period from 21 July to 8 August 2021 were analysed. RESULTS: A total of 567 athletes (416 injuries, 51 non-heat-related illnesses and 100 heat-related illnesses) and 541 non-athletes (255 injuries, 161 non-heat-related illnesses and 125 heat-related illnesses) were treated at the competition venue clinic. Patient presentation and hospital transportation rates per 1000 athletes were 50 and 5.8, respectively. Marathons and race walking had the highest incidence of injury and illness overall (17.9%; n=66). The highest incidence of injury (per participant) was noted in boxing (13.8%; n=40), sport climbing (12.5%; n=5) and skateboarding (11.3%; n=9), excluding golf, with the highest incidence of minor injuries. Fewer infectious illnesses than previous Summer Olympics were reported among the participants. Of the 100 heat-related illnesses in athletes, 50 occurred in the marathon and race walking events. Only six individuals were transported to a hospital due to heat-related illness, and none required hospital admission. CONCLUSION: Injuries and heat-related illnesses were lower than expected at the 2020 Tokyo Olympic Summer Games. No catastrophic events occurred. Appropriate preparation including illness prevention protocols, and treatment and transport decisions at each venue by participating medical personnel may have contributed to these positive results.

Differences in the Awareness and Knowledge of Radiological and Nuclear Events Among Medical Workers in Japan.

Background: Previous research revealed a lack of comfort and knowledge regarding nuclear and radiological events among medical staff. We investigated the awareness and knowledge of radiological and nuclear events among the Japanese medical staff by comparing differences by occupation (doctors, nurses, and other medical specialists). Methods: We conducted a cross-sectional questionnaire survey among trainees undergoing Japanese disaster medical training courses between July 2014 and February 2016. The differences by occupation were evaluated for all questions on awareness and knowledge concerning disasters or radiological and nuclear events and demographics. Results: Among the occupations, there were significant differences in the willingness to work onsite based on the types of disaster, familiarity with the national disaster medical response system, the accuracy rate of some knowledge about medical practice and the risk, and demographic characteristics such as practical experience and educational degree. The accuracy rates of responses to some questions on knowledge were very low in all occupations. Conclusion: There were significant differences in awareness and knowledge of radiological and nuclear events by occupation. We believe that the results can be used to develop and modify the content of training courses on radiological and nuclear events to make such courses beneficial for each healthcare worker.

Evaluation of bleeding control course for health-care providers in Japan.

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.

Prospective evaluation of the "Stop the Bleed" program in Japanese participants.

BACKGROUND: The Stop the Bleed (STB) program was developed to bring military bleeding control techniques into wider use among American civilians. It was introduced in Japan in case of mass casualty events during the Tokyo Olympic/Paralympic Games in 2021, and its effectiveness was prospectively evaluated. METHODS: Japanese physicians certified as STB instructors held bleeding control basic training courses from April to July 2019. Participants' knowledge was assessed using pre-training and post-training tests comprising five questions. One point was awarded for each correct answer, giving a maximum total score of 5. (Q1) What is the most common preventable trauma death?; (Q2) Which actions should be prioritized for bleeding victims?; (Q3) Which patients should be transferred to hospital first?; (Q4) How should a tourniquet be applied?; (Q5) How should pain associated with a tourniquet be managed? RESULTS: The study involved 157 participants (20 physicians/nurses, 82 medical students, 33 emergency services personnel, 22 police officers/security personnel). The mean±SD scores were 2.1±1.1 before training and 3.2±1.0 after training (p<0.01). The respective percentages of correct answers before and after training were 58% and 75% for Q1, 10% and 13% for Q2, 38% and 55% for Q3, 73% and 89% for Q4, and 33% and 91% for Q5. Q2 had the lowest percentage of correct answers and the poorest improvement. DISCUSSION: The STB program improved tourniquet knowledge. However, it was less effective in improving knowledge about which actions to prioritize for bleeding victims. This may be because the participants were well trained in basic life support and therefore expected to immediately commence cardiopulmonary resuscitation for patients in shock. The STB program is valuable in preparing Japanese people for mass casualty events during the Tokyo Olympic/Paralympic Games in 2021. LEVEL OF EVIDENCE: IV. STUDY TYPE: Therapeutic.

Endoplasmic Reticulum Associated Degradation of Spinocerebellar Ataxia-Related CD10 Cysteine Mutant.

Spinocerebellar ataxia (SCA) is one of the most severe neurodegenerative diseases and is often associated with misfolded protein aggregates derived from the genetic mutation of related genes. Recently, mutations in CD10 such as C143Y have been identified as SCA type 43. CD10, also known as neprilysin or neuroendopeptidase, digests functional neuropeptides, such as amyloid beta, in the extracellular region. In this study, we explored the cellular behavior of CD10 C143Y to gain an insight into the functional relationship of the mutation and SCA pathology. We found that wild-type CD10 is expressed on the plasma membrane and exhibits endopeptidase activity in a cultured cell line. CD10 C143Y, however, forms a disulfide bond-mediated oligomer that does not appear by the wild-type CD10. Furthermore, the CD10 C143Y mutant was retained in the endoplasmic reticulum (ER) by the molecular chaperone BiP and was degraded through the ER-associated degradation (ERAD) process, in which representative ERAD factors including EDEM1, SEL1L, and Hrd1 participate in the degradation. Suppression of CD10 C143Y ERAD recovers intracellular transport but not enzymatic activity. Our results indicate that the C143Y mutation in CD10 negatively affects protein maturation and results in ER retention and following ERAD. These findings provide beneficial insight into SCA type 43 pathology.

Analysis of chromosome translocation frequency after a single CT scan in adults.

We recently reported an increase in dicentric chromosome (DIC) formation after a single computed tomography (CT) scan (5.78-60.27 mSv: mean 24.24 mSv) and we recommended analysis of 2000 metaphase cells stained with Giemsa and centromere-FISH for dicentric chromosome assay (DCA) in cases of low-dose radiation exposure. In the present study, we analyzed the frequency of chromosome translocations using stored Carnoy's-fixed lymphocyte specimens from the previous study; these specimens were from 12 patients who were subject to chromosome painting of Chromosomes 1, 2 and 4. Chromosomes 1, 2 and 4 were analyzed in ∼5000 cells, which is equivalent to the whole-genome analysis of almost 2000 cells. The frequency of chromosome translocation was higher than the number of DICs formed, both before and after CT scanning. The frequency of chromosome translocations tended to be higher, but not significantly higher, in patients with a treatment history compared with patients without such a history. However, in contrast to the results for DIC formation, the frequency of translocations detected before and after the CT scan did not differ significantly. Therefore, analysis of chromosome translocation may not be a suitable assay for detecting chromosome aberrations in cases of low-dose radiation exposure from a CT scan. A significant increase in the frequency of chromosome translocations was not likely to be detected due to the high baseline before the CT scan; the high and variable frequency of translocations was probably due to multiple confounding factors in adults.

Increase in dicentric chromosome formation after a single CT scan in adults.

Excess risk of leukemia and brain tumors after CT scans in children has been reported. We performed dicentric chromosome assay (DCAs) before and after CT scan to assess effects of low-dose ionizing radiation on chromosomes. Peripheral blood (PB) lymphocytes were collected from 10 patients before and after a CT scan. DCA was performed by analyzing either 1,000 or 2,000 metaphases using both Giemsa staining and centromere-fluorescence in situ hybridization (Centromere-FISH). The increment of DIC formation was compared with effective radiation dose calculated using the computational dosimetry system, WAZA-ARI and dose length product (DLP) in a CT scan. Dicentric chromosome (DIC) formation increased significantly after a single CT scan, and increased DIC formation was found in all patients. A good correlation between the increment of DIC formation determined by analysis of 2,000 metaphases using Giemsa staining and those by 2,000 metaphases using Centromere-FISH was observed. However, no correlation was observed between the increment of DIC formation and the effective radiation dose. Therefore, these results suggest that chromosome cleavage may be induced by one CT scan, and we recommend 2,000 or more metaphases be analyzed in Giemsa staining or Centromere-FISH for DCAs in cases of low-dose radiation exposure.

Mammalian 5-formyluracil-DNA glycosylase. 1. Identification and characterization of a novel activity that releases 5-formyluracil from DNA.

5-Formyluracil (fU) is a major oxidative thymine lesion produced by reactive oxygen species and exhibits genotoxic and cytotoxic effects via several mechanisms. In the present study, we have searched for and characterized mammalian fU-DNA glycosylase (FDG) using two approaches. In the first approach, the FDG activity was examined using purified base excision repair enzymes. Human and mouse endonuclease III homologues (NTH1) showed a very weak FDG activity, but the parameter analysis and NaBH(4) trapping assays of the Schiff base intermediate revealed that NTH1 was kinetically incompetent for repair of fU. In the second approach, FDG was partially purified (160-fold) from rat liver. The enzyme was a monofunctional DNA glycosylase and recognized fU in single-stranded (ss) and double-stranded (ds) DNA. The most purified FDG fraction also exhibited monofunctional DNA glycosylase activities for uracil (U), 5-hydroxyuracil (hoU), and 5-hydroxymethyluracil (hmU) in ssDNA and dsDNA. The fU-excising activity of FDG was competitively inhibited by dsDNA containing U.G, hoU.G, and hmU.A but not by intact dsDNA containing T.A. Furthermore, the activities of FDG for fU, hmU, hoU, and U in ssDNA and dsDNA were neutralized by the antibody raised against SMUG1 uracil-DNA glycosylase, showing that FDG is a rat homologue of SMUG1.