Objective: Children are particularly vulnerable to heat-related illnesses due to their unique physiological and behavioral characteristics. Understanding the epidemiology and clinical features of heat-related illnesses in children is crucial for guiding targeted preventive measures and management strategies. This descriptive study aims to investigate the characteristics of pediatric patients with heat-related illness who were transferred to emergency departments in Japan. Methods: This study was a secondary analysis of the Heatstroke Study, led by the Heatstroke and Hypothermia Surveillance Committee of the Japanese Association for Acute Medicine. This study included pediatric patients (<18 years) with heat-related illness transferred to emergency departments in the summer from 2017 to 2021. We summarized the circumstances of onset, clinical characteristics, and outcomes. Results: Of the 3,154 registered patients, 146 children were included. Of them, 60% were male, with a median age of 15 years (interquartile range, 13–16 years). The most cases occurred in August (47%), and most (80%) were associated with sports activities and with outdoor settings (70%). Cases with a body temperature above 40 °C were rare (3%). Most cases were admitted to hospitals (75% to the general ward and 16% to the intensive care unit), and patients admitted to intensive care unit had altered consciousness with increased serum creatinine. There were two cases of mortality, both of which were out-of-hospital cardiac arrest. Conclusion Most pediatric cases with heat-related illness were middle or high school students, occurred in August, and were related to outdoor sports activity. Patients admitted to hospitals suffered altered consciousness, dehydration, and acute kidney injury.

We conducted a large-scale survey of sports injuries in college athletes. This study aimed to investigate trends in sports injuries and disabilities among college athletes by gender, discipline, individual and team competition, contact and noncontact competition, and other competition characteristics. A total of 1,137 college athletes (786 men and 351 women) were surveyed. A questionnaire survey was conducted to determine the club, regularity, and history of sports injuries and disorders (presence/absence, severity, time of injury, site of injury, diagnosis, and recurrence). The prevalence of sports injuries among college athletes was 59.7%. The prevalence was 74.7% in team and contact sports, with ankle and knee ligament injuries accounting for most injuries. The second highest prevalence rate was 66.7% for individual/contact sports, where martial arts-type sports are common. Elbow injuries were common due to the characteristics of martial arts-type sports. Chronic sports injuries of the ankle were common in noncontact/individual sports, and shoulder joint disorders were common in noncontact/team sports. Different trends in sports injuries and disabilities were found depending on the sport characteristics. Considering the characteristics of the sports is necessary to prevent sports injuries and disabilities.

Since students who would like to study Kampo medicine more have no opportunity to communicate each other in Northern Japanese Universities, we newly started joint study conferences held by medical students in 2013. The objectives of this paper are to report on these annually held student-based Kampo study conferences in the Hokkaido and Tohoku areas, and the ways each university studies Kampo medicine. In the conference, the students reported on their club activities. Then they studied the history of Kampo medicine and simulation of abdominal diagnosis, and performed group work on case reports together. The number of student participants in these conferences has tripled over 3 years from 18 to 58 (for a total of 111 participants). All members were satisfied with the content. And this reflects medical students' need for a wider perception of Kampo medicine, rather than a limited one gained in their university club activities. We hope this conference will play a major role in other nationwide student-based Kampo study conferences in the years to come.

The representative endoscopic features of primary intestinal follicular lymphoma are well known as small whitish polypoid nodules, but a magnified view has only been described in a few case reports. Herein, we report a case with intestinal follicular lymphoma in which magnifying endoscopy with narrow band imaging was helpful for prompt diagnosis. A 57-year-old Japanese woman underwent surveillance esophagogastroduodenoscopy. The endoscopic examination revealed confluent whitish granules in the duodenum, distinct from the nodules or polyps that are typical findings of intestinal follicular lymphoma. Magnifying endoscopy visualized whitish enlarged villi, and narrow band imaging emphasized an elongated and coiled vascular pattern. Based on these features, intestinal follicular lymphoma was highly suspected, and subsequent histological study confirmed the diagnosis. This case demonstrates that magnifying endoscopy with narrow band imaging was useful for the detection and prompt diagnosis of intestinal follicular lymphoma. The pathological features of intestinal follicular lymphoma are also discussed.
Asian Continental Ancestry Group ; Duodenal Neoplasms ; Duodenum ; Endoscopes, Gastrointestinal ; Endoscopy ; Endoscopy, Digestive System ; Female ; Humans ; Lymphoma, Follicular ; Narrow Band Imaging ; Polyps

The interval between undergraduate medical education and graduate medical education causes residents to become disorganized when they start their first-year residency programs.This disorganized transition may be stressful for residents and preceptors and may cause resident to make medical errors.We performed a pilot study to examine the degree to which program directors agree about the abilities required for the start of the first of year residency.
1) We asked the residency directors at university hospitals and residency hospitals nationwide (343 institutions) to indicate what abilities residents were expected to have at various stages of the residency program.The data received were then analyzed.
2) A total of 134 residency directors (39%) returned the questionnaire.We calculated the percentage (expectation rate) of institutions that reported expected prerequisites at the start of the first year of residency and calculated the accumulated values (cumulative rate) of the percentages.
3) Only 43 (30%) of 141 abilities upon the completion of residency-preparatory programs had a cumulative rate of more than 50%.
4) Domains for which the expectation rate was more than 50% at the start of residency were medicine and related knowledge and practical skills for obtaining physical measurements.
5) Physical examination and practical skills for which the cumulative rate was less than 50% on completion of residency-preparatory programs were those for the reproductive and urinary systems and pediatrics and the insertion and maintenance of intravenous lines and indwelling urinary catheters.
6) Disparities are likely between the abilities of residents and the tasks expected of them upon entry into a residency program.This problem must be urgently addressed through medical education and graduate medical education.

The purpose of this study was to noninvasively extract information about the size and muscle fiber density of muscular units through the inverse analysis of surface electromyograms. Surface motor unit action potentials (MUAPs) were recorded with a multi-channel electrode array arranged along the circumference direction of the biceps brachii. The depth and intensity of equivalent current dipoles were estimated through the inverse analysis of surface MUAPs. The simulation of inverse analysis of surface potentials generated by the muscular unit models showed that the relationship between the depth and the intensity depends on the muscular unit size and muscle fiber density.
In the simulation, we systematically varied the model parameters including distance from the skin, radius, and fiber density and used the inverse analysis to estimate the depth and intensity of current dipoles. And, our method to estimate the radius and fiber density of muscular units using estimated depth and intensity is demonstrated. Mean values (± SD) estimated from the surface MUAPs were 3.0±1.8mm for depth and 13.8±32.0nAm for intensity. The estimated distance ranged from slightly less than 1 mm to slightly more than 2 mm. The estimated radius ranged from 1.8 to 4.6 mm and fiber density from 0.7 to 5.4 fibers/mm².

We have developed a method for estimating the depth and intensity of muscular unit represented as equivalent current dipoles by the inverse analysis of surface electromyograms (EMGs) . In this study, the validity of the locations of current dipoles estimated through the inverse analysis was verified by animal experiments. Surface motor unit action potentials (MUAPs) were recorded from the gastrocnemius muscle activated by electrical stimulation at the ventral root of lumbar spinal cord (L4 or L5) of rats. After recording the surface MUAPs for the inverse analysis and glycogen depletion of active muscle fibers by repeated electrical stimulation, periodic acid-Schiff (PAS) staining was used to determine the position of muscle fibers belonging to an active single motor unit. In the results of the inverse analysis, the values of ‘goodness of fit’ between measured and calculated MUAP were 71%, 79% and 85%. Estimated depths of current dipoles ranged from 1.8 mm to 5.9 mm. The locations estimated through the inverse analysis were more medial and shallower than the actual distribution of active muscle fibers determined by PAS staining. These errors were probably caused by the effects of the boundary in the model, the relationship between the measurement area and the location of an active motor unit, and the artifacts such as deformation of the muscle during dissection and freezing.

We studied the mechanism for slowing surface electromyography (EMG) during fatiguing contraction using superimposed M-wave analysis. Seven healthy male subjects exerted 60% maximum voluntary contraction of isometric abductions in the left first dorsal interosseous muscle (FDI) until exhaustion. Simultaneously with voluntary contractions, the ulnar nerve was electrically stimulated at supramaximal intensity, and volitional EMG and superimposed M-waves were obtained. We examined the behavior of muscle fiber conduction velocity (MFCV) and median frequency (MDF) for both EMG, with the following results:
1) MFCV calculated from volitional EMG of FDI was about 6 m/s during 60% MVC.
2) The waveform of voluntary EMG detected from FDI slowed in all subjects during fatiguing contraction at 60% MVC, indicating fatigue had developed in the muscle.
3) As fatigue progressed, the waveform of the superimposed M-wave tended to decrease in amplitude and increase in duration.
4) As fatigue progressed, MDF and MFCV in volitional EMG decreased significantly (p<0.04) . The rate of change was larger in MDF than in MFCV (p<0.01) .
5) As fatigue progressed, MDF and MFCV in the superimposed M-wave decreased significantly (p<0.01) . The rate of change was larger in NIDF than in MFCV (p<0.05) .
These results suggested that MFCV and other peripheral factors affected the slowing of volitional EMG. Elongation of the depolarization zone in muscle fiber is proposed as a peripheral factor.

The purpose of this study was to examine the effects of short-term immobilization on the maximum voluntary contraction (MVC) force. The first dorsal interosseus (FDI) of 10 healthy male adults was immobilized for 1 week using casting tape. Atrophy of the muscle was estimated from a cross sectional view of magnetic resonance images (MRI) . To clarify the factors of a peripheral neuromuscular system contributing to the change in the MVC force, twitch force at rest was measured. The contribution of central factors was estimated from a voluntary activation (VA) index, which was obtained by the twitch interpolation method.
The MRI showed no significant changes in the cross sectional area. The MVC force declined after immobilization (p<0.01), and recovered after 1 week from the termination of immobilization (p<0.01) . Both the twitch force at rest and the VA at MVC declined after immobilization (p<0.01), and recovered after 1 week (p<0.05) .
The results indicate that the temporary decline of the MVC force was not accompanied by atrophy of the muscle. Furthermore the decline of the MVC was caused both by the deterioration of peripheral and central functions in the neuromuscular system. Possible factors in the peripheral and central neuromuscular systems affected by the immobilization were discussed.

We evaluated motor unit (MU) fatigue in the first dorsal interosseous muscle (FDI) using the collision principle. Eight healthy men exerted 70% (short-duration fatigue task: SDF task) and 30% (long-duration fatigue task: LDF task) maximum voluntary contraction of isometric abductions in the left FDI until exhausted. Before and after voluntary contractions, the ulnar nerve was stimulated at the wrist and elbow with supramaximal intensity, and a pair of M-waves was obtained. Fatiguerelated changes were studied in mean power frequency (MPF), averaged rectified value (ARV) calculated from surface EMG, and motor nerve conduction velocity (MCV) and distribution of motor nerve conduction velocity (DMCV) calculated from M-waves. The MPF of voluntary EMG decreased, whereas ARV increased significantly during SDF and LDF tasks, indicating fatigue had developed in the FDI. Endurance was significantly shorter in the SDF task than in the LDF task (p<0.01), whereas differences between tasks were not seen in MPF and ARV changes. Tasks did not affect MCV, but lower components in DMCV increased for both tasks. Increased lower components were larger in the LDF task than in the SDF task. The shift in DMCV indicated that fatigued MUs stopped activity and enduring MUs, which had lower axon conduction velocity, were activated selectively. These results suggest that the collision principle is applicable in evaluating motor unit fatigability.