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Background Sumo is a sport that requires wrestlers to develop their physique from childhood for athletic advantage. However, the energy expenditure and energy balance required for the growth of junior Sumo wrestlers remain unclear. This study aimed to determine the energy balance of junior Sumo wrestlers over six months using doubly labeled water (DLW) and bioelectrical impedance analysis (BIA). Methodology A total of 12 male Sumo wrestlers were affiliated with a local Sumo club (average age = 15 ± 1 years). The total energy expenditure (TEE) was measured using DLW, whereas body composition was evaluated using BIA. Daily physical activity was quantified using a tri-accelerometer (Active style Pro HJA-750C). Results The TEE was 4,194 ± 734 kcal/day, while daily physical activity without training was 786 ± 50 minutes. Within six months, the body weight increased by 2.0 ± 3.2 kg, fat-free mass (FFM) was augmented by 2.1 kg, while fat mass did not change significantly. The surplus energy accumulated was 5.6 ± 213 kcal/day. Conclusions The excess energy of junior Sumo wrestlers predominantly increases their FFM. To increase their physical prowess, wrestlers adhere to a lifestyle characterized by high-intensity training and attenuated daily physical activity., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Institutional Review Board of the University of Tsukuba, Institutes of Health and Sports Sciences issued approval Ref.Tai 019-156. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: This work was supported by Research Fellowships from JSPS KAKENHI awarded to HS (18K17882 and 23H03279) and KW (23K10738), as well as the Tanuma Green House Foundation awarded to HS. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Ogawa et al.)

The study explores the relationship between phase angle (PhA), an indicator of cellular health, and metabolic health parameters among junior sumo wrestlers in Japan. Given the demanding lifestyle and high-energy diets of sumo wrestlers that predispose them to metabolic syndrome post-retirement, this study focuses on a younger cohort. The primary aim is to evaluate if PhA could serve as an early indicator of metabolic health issues within this unique demographic. A total of 14 sumo wrestlers aged 9-17 years were assessed to determine the relationship between PhA and various metabolic markers, including glycated hemoglobin (HbA1c), using a TANITA MC-780A-N body composition analyzer and standard blood tests. Bivariate regression analysis and Pearson's correlation revealed a negative relationship between PhA and HbA1c even after adjusting for age and weight (ß = -0.496, r 2  = 0.776, r = -0.756, p = 0.004). The results indicate a significant negative relationship between PhA and HbA1c levels, suggesting that lower PhA values, which indicate poorer cellular integrity, are associated with higher HbA1c levels, signifying impaired glycemic control. These findings underscore the potential of PhA as a valuable biomarker for monitoring metabolic health in young sumo wrestlers, with implications for early intervention and management strategies., (© 2024 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

The medial preoptic area (MPOA) is a sexually dimorphic region of the brain that regulates social behaviors. The sexually dimorphic nucleus (SDN) of the MPOA has been studied to understand sexual dimorphism, although the anatomy and physiology of the SDN is not fully understood. Here, we characterized SDN neurons that contribute to sexual dimorphism and investigated the mechanisms underlying the emergence of such neurons and their roles in social behaviors. A target-specific neuroanatomical study using transgenic mice expressing Cre recombinase under the control of Calb1 , a gene expressed abundantly in the SDN, revealed that SDN neurons are divided into two subpopulations, GABA neurons projecting to the ventral tegmental area (VTA), where they link to the dopamine system (Calb VTA neurons), and GABA neurons that extend axons in the MPOA or project to neighboring regions (Calb nonVTA neurons). Calb VTA neurons were abundant in males, but were scarce or absent in females. There was no difference in the number of Calb nonVTA neurons between sexes. Additionally, we found that emergence of Calb VTA neurons requires two testicular androgen actions that occur first in the postnatal period and second in the peripubertal period. Chemogenetic analyses of Calb VTA neurons indicated a role in modulating sexual motivation in males. Knockdown of Calb1 in the MPOA reduced the intromission required for males to complete copulation. These findings provide strong evidence that a male-specific neural pathway from the MPOA to the VTA is organized by the two-step actions of testicular androgens for the modulation of sexually motivated behavior. SIGNIFICANCE STATEMENT The MPOA is a sexually dimorphic region of the brain that regulates social behaviors, although its sexual dimorphism is not fully understood. Here, we describe a population of MPOA neurons that contribute to the sexual dimorphism. These neurons only exist in masculinized brains, and they project their axons to the ventral tegmental area, where they link to the dopamine system. Emergence of such neurons requires two testicular androgen actions that occur first in the postnatal period and second in the peripubertal period. These MPOA neurons endow masculinized brains with a neural pathway from the MPOA to the ventral tegmental area and modulate sexually motivated behavior in males., (Copyright © 2023 the authors.)

Background: People began to wear face masks during physical activities due to spread of COVID-19. There are no previous studies about the need for wearing masks while running., Methods: Assuming a citizen runner who runs full marathon in 4 hours, we verified the path and the amount of droplet dispersal, setting a humanoid mannequin with a mask in simulated running environment (Experiment 1). We also had six adults exercise in the same environment to examine droplet behaviors when not wearing a face mask (Experiment 2). Average droplet size was determined, and repeated measures ANOVA was carried out to examine statistical significance. To evaluate observed droplet behaviors, theoretical solutions of the downfall motion of large droplets were then derived, taking air resistance into consideration., Results: Experiment 1: wearing a face mask caused more droplets to adhere to the face; Experiment 2: droplets were emitted in conversation, coughing or sneezing, and they fell within social distancing. Average droplet size was not sensitive to the wind velocity. It could vary with a significant difference for time and wind velocity. Observed velocity and path of droplet can be expressed by the theoretical solutions., Conclusions: Velocity and path of large droplets can be expressed by the theoretical solution of particles in downfall motion under air resistance. We therefore conclude that wearing a mask while running gives adverse effects in preventing infection. Possibility of droplet transmission while running is considered low even when not wearing a face mask, as long as social distancing is ensured.

Introduction: Few studies have examined the influence of different water depths on the airway impedance measured by forced oscillation technique in healthy adults., Methods: Eleven healthy men (23.2 ± 1.5 years old) participated in this study. We measured the respiratory impedance assessed with the resistance at frequency of 5 Hz and 20 Hz, the reactance at frequency of 5 Hz, and frequency of resonance. To compare the influence of water depths, we carried out one dryland (DL) and two water level conditions: clavicle level (CL) and xiphoid appendix level (XA)., Results: The respiratory resistance at frequency of 5 Hz was higher in CL and XA than DL, and at 20 Hz was significantly higher in CL than DL. The respiratory reactance at 5 Hz was lower in CL and XA than DL, and frequency of resonance was higher in CL and XA than DL., Conclusion: These results suggested that water immersion above xiphoid appendix level increase airway resistance., (Copyright © 2021 Elsevier B.V. All rights reserved.)

This study aimed to investigate the difference in the prevalence, severity, and risk factors of dysmenorrhea between Japanese female athletes and non-athletes in universities. The participants were 18 to 30 years old with no history of a previous pregnancy and/or childbirth. After application of the exclusion criteria, the cohort comprised 605 athletes and 295 non-athletes. An anonymous questionnaire, which included self-reported information on age, height, weight, age at menarche, menstrual cycle days, menstrual duration, dysmenorrhea severity, sleeping hours, dietary habits, exercise habits, training hours, and competition level was administered. Compared with athletes, non-athletes had a higher prevalence of dysmenorrhea (85.6% in athletes, 90.5% in non-athletes, p < 0.05); non-athletes also demonstrated increased severity (none/mild 27.8%, moderate 19.3%, and severe 52.9% in athletes; none/mild 21.2%, moderate 17.2%, and severe 61.6% in non-athletes; p < 0.05). Factors related to severe dysmenorrhea in athletes included long training hours, early menarche, and prolonged menstrual periods. In non-athletes, short menstrual cycle days and extended menstrual periods were related to severe dysmenorrhea. The prevalence and severity of dysmenorrhea were higher among non-athletes than among athletes; different factors were related to severe dysmenorrhea in these two groups. Thus, different strategies are necessary to manage dysmenorrhea for athletes and non-athletes in universities.

Purpose: Exercise is a key factor in preventing obesity and metabolic syndrome. Sumo wrestlers increase their body size from childhood for athletic advantage; however, the risk of metabolic syndrome in junior sumo wrestlers is undetermined. Preventive measures against pediatric obesity should be initiated during childhood to prevent obesity in adulthood, considering its high global incidence. We comparatively evaluated the risk factors for metabolic syndrome in junior sumo wrestlers and children with obesity., Methods: We enrolled 70 male children (age 9-17 years [sumo group, n = 14] and 9-14 years [other sports and non-exercise groups, n = 28 each]) and evaluated their anthropometric parameters (height, weight, body mass index z-score, obesity rate, waist circumference, waist to height ratio) and hematological parameters (total, low-density, high-density, and non-high-density lipoprotein-cholesterol; triglycerides; plasma glucose, and glycated hemoglobin levels)., Results: The BMI z-score, obesity rate, waist circumference (p < 0.05, along with the non-exercise group), and systolic blood pressure were significantly higher and the high-density cholesterol level was lower in the sumo group than in the other sports group (p < 0.05). The waist to height ratio was significantly higher in the non-exercise group than in the other sports group (p < 0.05). No significant difference was found in other blood lipid, plasma glucose (significantly lower level than the reference range in the sumo group, p < 0.05), and glycated hemoglobin (within the reference range in all groups) levels among the three groups., Conclusion: Junior sumo wrestlers had a larger body size and higher blood pressure than children with obesity who exercised regularly. This provides direction for future research into targeted preventive interventions against metabolic syndrome for junior sumo wrestlers with large body size.

Introduction: Atypical femoral fractures (AFFs) have been correlated with long-term use of bisphosphonates (BPs), glucocorticoids (GCs), and femoral geometry. We investigated the incidence and characteristics of subtrochanteric (ST) and diaphyseal (DP) AFFs in all institutes in a super-aging prefectural area., Materials and Methods: We performed a blinded analysis of radiographic data in 87 patients with 98 AFFs in all institutes in Yamagata prefectural area from 2009 to 2014. Among the 98 AFFs, 57 AFFs comprising 11 ST fractures in 9 patients and 46 DP fractures in 41 patients with adequate medical records and X-rays were surveyed for time to bone healing and geometry., Results: Of the 87 patients, 67 received BPs/denosumab (77%) and 10 received GCs (11%). Surgery was performed in 94 AFFs. Among 4 AFFs with conservative therapy, 3 required additional surgery. In univariate regression analyses for ST group versus DP group, male-to-female ratio was 2/7 versus 1/40, mean age at fracture was 58.2 (37-75) versus 78 (60-89) years, rheumatic diseases affected 55.5% (5/9) versus 4.9% (2/41), femoral lateral bowing angle was 1.7 (0-6) versus 11.8 (0.8-24)°, GC usage was 67% (6/9) versus 4.9% (2/41), and bone healing time was 12.1 (6-20) versus 8.1 (3-38) months (p < 0.05). In multivariate analyses, higher male-to-female ratio, younger age, greater proportion affected by rheumatic diseases, and higher GC usage remained significant (p < 0.05)., Conclusions: The incidence of AFFs in our prefectural area was 1.43 cases/100,000 persons/year. This study suggests that the onset of ST AFFs have greater correlation with the worse bone quality, vice versa, the onset of DP AFFs correlated with the bone geometry. The developmental mechanisms of AFFs may differ significantly between ST and DP fractures.

Prosthetic joint surgeries, total hip arthroplasty (THA) or bipolar hemiarthroplasty (BHA) and joint preservation surgeries can be performed for avascular osteonecrosis of femoral head (ONFH) with collapse. Although excellent surgical results have been reported, long-term survivorship and postoperative complications are a great concern. The purpose of this study was to report a case of bilateral disassembly of bipolar heads within 10 years after BHA for ONFH. A 61-year-old man, whose occupation was carpenter, underwent bilateral BHA for ONFH at another hospital when he was 57 years old. He had acute right hip pain during working and visited our institute. Radiographs revealed intra-articular (outer and inner head) disassembly of the right bipolar head, and conversion to THA was performed. Five years later, he had contralateral (left) hip pain. Radiographs revealed disassembly of bipolar head, as had occurred with the right hip, and similar conversion surgery was performed for the left hip. Marked wear and detachment of the polyethylene bearings of the outer head and failure of the locking mechanism between a skirted 22-mm-diameter inner head and polyethylene insert were observed in both hips at each revision surgery. Degeneration of the acetabulum were also observed in both hips. The failure of the self-centering mechanism because of degenerative change of the acetabulum, impingement of the outer head and neck, and high activity seemed to be the causes of disassembly of the bilateral bipolar heads. Therefore, it is important to select the type of prostheses depending on the age, activity and occupation of each patient.

Background: Hexuronic acids such as D-galacturonic acid and D-glucuronic acid can be utilized via different pathways within the metabolism of microorganisms. One representative, the oxidative pathway, generates α-keto-glutarate as the direct link entering towards the citric acid cycle. The penultimate enzyme, keto-deoxy glucarate dehydratase/decarboxylase, catalyses the dehydration and decarboxylation of keto-deoxy glucarate to α-keto-glutarate semialdehyde. This enzymatic reaction can be tracked continuously by applying a pH-shift assay., Results: Two new keto-deoxy glucarate dehydratases/decarboxylases (EC 4.2.1.41) from Comamonas testosteroni KF-1 and Polaromonas naphthalenivorans CJ2 were identified and expressed in an active form using Escherichia coli ArcticExpress(DE3). Subsequent characterization concerning K m , k cat and thermal stability was conducted in comparison with the known keto-deoxy glucarate dehydratase/decarboxylase from Acinetobacter baylyi ADP1. The kinetic constants determined for A. baylyi were K m 1.0 mM, k cat 4.5 s -1 , for C. testosteroni K m 1.1 mM, k cat 3.1 s -1 , and for P. naphthalenivorans K m 1.1 mM, k cat 1.7 s -1 . The two new enzymes had a slightly lower catalytic activity (increased K m and a decreased k cat ) but showed a higher thermal stability than that of A. baylyi. The developed pH-shift assay, using potassium phosphate and bromothymol blue as the pH indicator, enables a direct measurement. The use of crude extracts did not interfere with the assay and was tested for wild-type landscapes for all three enzymes., Conclusions: By establishing a pH-shift assay, an easy measurement method for keto-deoxy glucarate dehydratase/decarboxylase could be developed. It can be used for measurements of the purified enzymes or using crude extracts. Therefore, it is especially suitable as the method of choice within an engineering approach for further optimization of these enzymes.