Glycated hemoglobin (HbA1c) is independently associated with the bioelectrical impedance phase angle in junior sumo wrestlers: A pilot study.

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, r2 = 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.

Metabolome analyses of skin dialysate: Insights into skin interstitial fluid biomarkers.

BACKGROUND: Metabolites in biofluids can serve as biomarkers for diagnosing diseases and monitoring body conditions. Among the available biofluids, interstitial fluid (ISF) in the skin has garnered considerable attention owing to its advantages, which include inability to clot, easy access to the skin, and possibility of incorporating wearable devices. However, the scientific understanding of skin ISF composition is limited. OBJECTIVE: In this study, we aimed to compare metabolites between skin dialysate containing metabolites from the skin ISF and venous blood (plasma) samples, both collected under resting states. METHODS: We collected forearm skin dialysate using intradermal microdialysis alongside venous blood (plasma) samples from 12 healthy young adults. We analyzed these samples using capillary electrophoresis-fourier transform mass spectrometry-based metabolomics (CE-FTMS). RESULTS: Significant positive correlations were observed in 39 metabolites between the skin dialysate and plasma, including creatine (a mitochondrial disease biomarker), 1-methyladenosine (an early detection of cancer biomarker), and trimethylamine N-oxide (a posterior predictor of heart failure biomarker). Based on the Human Metabolome Technologies database, we identified 12 metabolites unique to forearm skin dialysate including nucleic acids, benzoate acids, fatty acids, amino acids, ascorbic acid, 3-methoxy-4-hydroxyphenylethyleneglycol (an Alzheimer's disease biomarker), and cysteic acid (an acute myocardial infarction biomarker). CONCLUSION: We show that some venous blood biomarkers may be predicted from skin dialysate or skin ISF, and that these fluids may serve as diagnostic and monitoring tools for health and clinical conditions.

Anatomical study of the modified direct posterior gluteal splitting approach for acetabular fractures.

BACKGROUND: In this study, we investigated the area that can be addressed with an approach in which the skin incision is made directly above the dorsal column with Thiel cadaveric specimens. METHODS: Six Thiel cadaveric specimens were prepared. A skin incision was made directly above the dorsal column. The accessible proximal end from the proximal part of the greater sciatic notch to the gluteal ridge and the accessible distal end of the ischium were marked with a flat chisel. A molded 8-hole reconstruction plate was placed from the base of the ischium toward the gluteal ridge and fixed with 3 screws proximally and 2 screws distally. The length of the skin incision and the distance from each reference point on the bone to the reachable markings were assessed after the muscles were removed. RESULTS: Mean skin incision length was 9.3 ± 0.7 (range, 8.0-10.0) cm. In 3 of 6 cases, proximal screws were inserted through different spaces between muscle fibers. In all cases, we were able to reach at least the greater sciatic notch, the gluteal ridge at the level of superior border of the acetabulum, and the base of the ischial tuberosity. In all cases, an 8-hole plate could be placed from the gluteal ridge to the base of the ischium. There were no superior gluteal artery or sciatic nerve injuries in any of the cases. CONCLUSION: We anatomically investigated the area that can be addressed with an approach in which the skin incision was made directly above the dorsal column. In all cases, we were able to access the areas needed to reduce the fracture and place the plates necessary to stabilize the fracture through a 9.3 ± 0.7 cm skin incision. This approach can be a useful minimally invasive posterior approach for acetabular fractures.

Evolution of the term "epicondyle of the femur": Revisiting the anatomical and surgical literature.

The femoral epicondyle is an anatomical bony landmark essential for surgeons and anatomists, but there are discrepancies between the two fields when using this term. In current orthopedic surgery, it commonly denotes the small bony prominence of the femoral condyle. Given the derivation, "epicondyle" should be a region projecting laterally from the articular surface rather than a point. These discrepancies in usage are found not only between the fields but also in the literature. This article reviews the narrative definition of "epicondyle of the femur" in surgery and the evolution of the term in anatomy. The outcomes of the review suggest a relationship between the differing perceptions of the epicondyle and the evolution of the term. In reports of studies related to the epicondyle, it is strongly recommended that the definition of the word is clearly stated, with an understanding of its evolution.

GH and IGF-1 in skin interstitial fluid and blood are associated with heat loss responses in exercising young adults.

PURPOSE: Sweat glands and cutaneous vessels possess growth hormone (GH) and insulin-like growth factor 1 (IGF-1) receptors. Here, we assessed if exercise increases GH and IGF-1 in skin interstitial fluid, and whether baseline and exercise-induced increases in GH and IGF-1 concentrations in skin interstitial fluid/blood are associated with heat loss responses of sweating and cutaneous vasodilation. METHODS: Sixteen young adults (7 women) performed a 50-min moderate-intensity exercise bout (50% VO2peak) during which skin dialysate and blood samples were collected. In a sub-study (n = 7, 4 women), we administered varying concentrations of GH (0.025-4000 ng/mL) and IGF-1 (0.000256-100 µg/mL) into skin interstitial fluid via intradermal microdialysis. Sweat rate (ventilated capsule) and cutaneous vascular conductance (CVC) were measured continuously for both studies. RESULTS: Exercise increased sweating and CVC (both P < 0.001), paralleled by increases of serum GH and skin dialysate GH and IGF-1 (all P ≤ 0.041) without changes in serum IGF-1. Sweating was positively correlated with baseline dialysate and serum GH levels, as well as exercise-induced increases in serum GH and IGF-1 (all P ≤ 0.044). Increases in CVC were not correlated with any GH and IGF-1 variables. Exogenous administration of GH and IGF-1 did not modulate resting sweat rate and CVC. CONCLUSION: (1) Exercise increases GH and IGF-1 levels in the skin interstitial fluid, (2) exercise-induced sweating is associated with baseline GH in skin interstitial fluid and blood, as well as exercise-induced increases in blood GH and IGF-1, and (3) cutaneous vasodilation during exercise is not associated with GH and IGF-1 in skin interstitial fluid and blood.

Nutritional and Training Strategies for Actual Competition in World-Class Japanese Female Wrestler: A Case Report.

Wrestlers have a risk of relative energy deficiency in sports because they believe that they can gain an advantage over their opponents by temporarily adopting weight-making strategies even women. However, precise methods of making weight and the effect of manipulating body mass (BM) on health and performance in female wrestlers have not been reported. Our study aimed to report a case of weight making in a world-class female wrestler, who won the world competition seven times in 5-y and had oligomenorrhea. We obtained the BM, blood, urine, and saliva samples, hand grip strength, subjective condition a month before the match (baseline), and 3-d before the match (day-3), and food and physical activity records during baseline and 10 d before the competition. The wrestler lost 4.7% of BM from baseline to day-3 and 7.6% of BM to the match by method to reduce energy intake and enhance dehydration. Hand grip strength did not change by weight loss. After weigh-in, the wrestler took the recovery food containing 4.9 g/kg BM of carbohydrate. Although these weight strategies may at least contribute to the success of wrestlers, the impact on health needs to be clarified in future studies.

A new injection method for identifying the subpopliteal recess of the knee.

The posterolateral region of the knee has a complex and diverse anatomy. Hydrarthrosis of the knee can potentially communicate with other parts of the joint space. The joint fluid distribution reflects anatomical communications between synovial spaces. To observe the continuity between the knee joint cavity and the surrounding bursa, we devised a dissection method with a new injection agent, an eosin-containing congealed liquid that spreads uniformly over the entire space. The purpose of this study was to perform a detailed examination of the subpopliteal recess (SPR) where a bursa connects to the knee joint capsule. We also reported the advantages of this new injection agent compared with conventional materials (latex and epoxy resin). Twenty-two formalin-fixed cadavers (34 knees), two N-vinyl-pyrrolidone (NVP)-fixed cadavers (4 knees), and two cadavers (3 knees) fixed by Thiel's method were used. After filling the knee joint space and SPR with eosin congealed liquid, the specimens were dissected to investigate the morphology of the SPR. In addition, three different types of injection agents were assessed. The SPR extended distally along the popliteus tendon. The SPR length was 22.64 ± 11.38 mm from the upper end of the lateral tibial condyle to the lower end of the depression. The existence of a fabellofibular ligament made the SPR significantly longer, but abrasion of the femoral articular cartilage did not affect the SPR. Furthermore, the relationship between the popliteus muscle and the SPR was classified into three types (types 1-3). Types 2 and 3 in which the SPR extended to the proximal tibiofibular joint may cause instability of the knee joint. The eosin congealed liquid was highly useful in many aspects, such as fluidity and injection workability. The new dissection method with eosin congealed liquid provides insights into the anatomy of the posterior lateral knee, which are useful for radiological diagnoses and clinical treatments.

A histological study of the adult ligamentum arteriosum: Novel findings with application to a patent ductus arteriosus.

The ligamentum arteriosum (LA) is the vestigial fibrous remnant of the ductus arteriosus (DA), a fetal vessel arising from the left dorsal segment of the sixth aortic arch that connects the left pulmonary artery to the aortic arch. Incomplete obliteration of the DA results in a patent ductus arteriosus (PDA), causing the shunting of oxygen-rich blood to recirculate to the lungs, which can lead to pulmonary hypertension. The current study aims to further elucidate the structural characteristics of the LA via histological analysis with data gathered from adult cadaveric specimens. The LA was harvested and histologically observed with Hematoxylin and Eosin, van Gieson, and Masson's trichrome staining. Fibrous and muscle tissues were observed in all 25 specimens. The LA was categorized into three types based on the morphological features of the LA. Type I (vessel-like structure), type II (fibrotic tissue with duct-like structure), and type III (no duct-like structure) were found in 4.0%, 80.0%, and 16.0%, respectively. Finally, the remnant of a valve in the LA was also observed at the junction between the AA and LA. We suggest that this valve be called the "pulmonary-aortic valve." In the majority of the adult LAs, a duct-like structure was still present. These data could better elucidate our understanding of the pathology and etiology of a PDA.

Effects of heat-killed Lactiplantibacillus plantarum TWK10 on exercise performance, fatigue, and muscle growth in healthy male adults.

Consumption of Lactiplantibacillus plantarum TWK10 (TWK10) has beneficial probiotic effects, improves exercise endurance performance, regulates body composition, and mitigates aging-related problems in mice and humans. Here, we investigated the effects of heat-killed TWK10 on exercise endurance performance, muscle weight and strength, fatigue, and body composition in a double-blind, placebo-controlled clinical trial. Thirty healthy males aged 20-40 years were assigned to the Control group or heat-killed TWK10 group (TWK10-HK) in a balanced order according to each individual's initial maximal oxygen uptake. After 6-week administration, the exercise endurance time in the TWK10-HK was significantly increased (p = 0.0028) compared with that in the Control group. The grip strength on the right and left hands of the subjects was significantly increased (p = 0.0002 and p = 0.0140, respectively) in the TWK10-HK compared with that in the Control group. Administration of heat-killed TWK10 resulted in a significant increase (p = 0.0275) in muscle weight. After 6-week administration, serum lactate, and ammonia levels were significantly lower in the TWK10-HK group than in the Control group during the exercise and recovery periods. These findings demonstrate that heat-killed TWK10 has significant potential to be used as a postbiotic for humans.

Community-Based Trial Educational Heat Disorder Program in Local Salons for Older Adults.

We investigated whether a combined program for heat disorder prevention can improve the behaviors and knowledge of heat disorder prevention in older adults participating in salons. This non-randomized parallel-group comparison study includes 59 participants from two salons. The intervention group met on alternate weeks on a salon day to watch an educational DVD and conduct hands-on education (Wet-Bulb Globe Temperature (WBGT) measurements inside and outside the meeting place). The intervention group conducted calls every other week except salon week to prevent action for heat disorder prevention information based on a leaflet and monitored WBGT in their bedrooms daily at bedtime. We assessed changes in recognition of heat disorders and prevention behavior between baseline, one and a half months after intervention, and post-season (approximately two months after baseline), using the Wilcoxon signed rank test. Recognition of heat disorder scores and preventive behavior improved from pre- to post-season in the intervention group. It was suggested that the approach toward older adults participating in salons could improve their recognition and behavior in preventing heat disorders.

Effects of acute resistance exercise on exhaled nitric oxide levels in non-asthmatic male.

Fractional nitric oxide (FeNO) is an index of eosinophilic airway inflammation. However, the effect of acute resistance exercise on FeNO is not completely known, in non-asthmatics. In this study, we aimed to assess the effects of acute resistance exercise on FeNO levels in non-asthmatics. Ten participants completed both exercise and control sessions. The resistance exercise routine consisted of three sets of 10 repetitions, each at 75 % of the one-repetition maximum, including vertical chest press, lateral pull-down, leg press, leg extension, and abdominal exercises. Additionally, FeNO levels and respiratory impedance were measured, and blood samples were collected from each participant at baseline, immediately after exercise (post), and 30 min after exercise (post 30). At baseline, post, and post 30, the FeNO levels did not significantly differ between the exercise and control sessions (17.1 ± 4.7 vs. 18.5 ± 3.8 vs. 16.9 ± 3.8 ppb, respectively) and exercise sessions (16.6 ± 3.4 vs. 19.3 ± 7.6 vs. 18.3 ± 5.6 ppb, respectively). Therefore, acute resistance exercise lasting approximately 30 min did not exert an impact on FeNO levels.

Galanin receptors modulate cutaneous vasodilation elicited by whole-body and local heating but not thermal sweating in young adults.

Galanin receptor subtypes GAL1, GAL2, and GAL3 are involved in several biological functions. We hypothesized that 1) GAL3 receptor activation contributes to sweating but limits cutaneous vasodilation induced by whole-body and local heating without a contribution of GAL2; and 2) GAL1 receptor activation attenuates both sweating and cutaneous vasodilation during whole-body heating. Young adults underwent whole-body (n = 12, 6 females) and local (n = 10, 4 females) heating. Forearm sweat rate (ventilated capsule) and cutaneous vascular conductance (CVC; ratio of laser-Doppler blood flow to mean arterial pressure) were assessed during whole-body heating (water-perfusion suit circulated with warm (35 °C) water), while CVC was also assessed by local forearm heating (from 33 °C to 39 °C and elevated to 42 °C thereafter; each level of heating maintained for ∼30 min). Sweat rate and CVC were evaluated at four intradermal microdialysis forearm sites treated with either 1) 5% dimethyl sulfoxide (control), 2) M40, a non-selective GAL1 and GAL2 receptor antagonist, 3) M871 to selectively antagonize GAL2 receptor, or 4) SNAP398299 to selectively antagonize GAL3 receptor. Sweating was not modulated by any GAL receptor antagonist (P > 0.169), whereas only M40 reduced CVC (P ≤ 0.003) relative to control during whole-body heating. Relative to control, SNAP398299 augmented the initial and sustained increase in CVC during local heating to 39 °C, and the transient increase at 42 °C (P ≤ 0.028). We confirmed that while none of the galanin receptors modulate sweating during whole-body heating, GAL1 receptors mediate cutaneous vasodilation. Further, GAL3 receptors blunt cutaneous vasodilation during local heating.

Consideration on size, velocity and path of droplets emitted during running.

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.

Double Inferior Vena Cava with Major Predominance of the Left Inferior Vena Cava: A Cadaver Case Report.

We encountered a case of a double inferior vena cava with major predominance of the left inferior vena cava during an anatomical dissection course for medical students in 2015. The right inferior vena cava (normal inferior vena cava) was 2.0 mm wide, and the left inferior vena cava was 23.2 mm wide. The fine right inferior vena cava began at the right common iliac vein, ascended along the right side of the abdominal aorta, and then joined the left inferior vena cava at the level of the lower margin of the first lumbar vertebra. The dominant left inferior vena cava started from the left common iliac vein and ascended along the left side of the abdominal aorta. Most patients with a double inferior vena cava are asymptomatic, and these variants are incidentally detected by computed tomography or magnetic resonance imaging. Their presence may have significant implications for surgery, particularly abdominal surgery in patients with paraaortic lymphadenopathy and in those undergoing laparoscopic radical nephrectomy or inferior vena cava filter placement. We herein discuss the embryology of a double inferior vena cava based on detailed anatomical data of the variations of a double inferior vena cava, including those that require clinical attention.

Enzymatically modified isoquercitrin in soy protein temporarily enhanced the plasma amino-acid concentrations, antioxidant index, and plasma hormone levels: a randomized, double-blind cross-over trial.

This study investigated the effects of a dietary protein supplement containing enzymatically modified isoquercitrin (EMIQ) on plasma amino-acid levels in healthy people. A randomized double-blind cross-over trial (UMIN000044791) was conducted with a sample of nine healthy individuals. These participants ingested soy protein with or without 42 mg EMIQ for 7 days after performing mild exercise. Plasma amino-acid levels were measured before ingestion and at 15, 30, 45, 60, 90, 120, 180, and 240 min after ingestion on the last day. The concentrations of total amino acids at 0 and 120 min and easily oxidized amino acids at 120 min were significantly higher in the plasma of individuals who consumed 42 mg EMIQ. Oxidative stress levels were lower and plasma testosterone levels were higher in participants who ingested soy protein with 42 mg EMIQ than in those who did not. These results suggest that daily ingestion of soy protein with 42 mg EMIQ can be useful for effective protein absorption.

Serum, interstitial and sweat ATP in humans exposed to heat stress: Insights into roles of ATP in the heat loss responses.

Hyperthermia increases intravascular adenosine triphosphate (ATP) and is associated with greater hyperthermia-induced cutaneous vasodilation. Hyperthermia may also increase skin interstitial fluid ATP thereby activating cutaneous vascular smooth muscle cells and sweat glands. We evaluated the hypothesis that whole-body heating would increase skin interstitial fluid ATP, and this response would be associated with an increase in cutaneous vasodilation and sweating. Nineteen (8 females) young adults underwent whole-body heating using a water-perfusion suit to increase core temperature by ~1°C during which time cutaneous vascular conductance (CVC, ratio of laser-Doppler blood flow to mean arterial pressure) and sweat rate (ventilated capsule technique) were measured at four forearm skin sites to minimize between-site variations. Dialysate from the skin sites were collected via intradermal microdialysis. Heating increased serum ATP, CVC, and sweat rate (all p ≤ 0.031). However, heating did not modulate dialysate ATP (median, baseline vs. end-heating: 2.38 vs. 2.70 nmol/ml) (p = 0.068), though the effect size was moderate (Cohen's d = 0.566). While the heating-induced increase in CVC was not correlated with changes in serum ATP (r = 0.439, p = 0.060), we observed a negative correlation (rs = -0.555, p = 0.017) between dialysate ATP and CVC. We did not observe a significant correlation between the heating-induced sweating and serum, dialysate, or sweat ATP (rs = 0.091 to -0.322, all p ≥ 0.222). Altogether, we showed that passive heating increases ATP in blood and possibly skin interstitial fluid, with the latter potentially blunting cutaneous vasodilation. However, ATP does not appear to modulate sweating.

The Key Structure of the Facial Soft Tissue: The Superficial Musculoaponeurotic System.

The superficial musculoaponeurotic system (SMAS) was advocated by Mitz and Peyronie in 1976. The concept of this superficial fascia was established by surgical findings of facelift surgery and is familiar to plastic surgeons and anatomists. However, detailed characteristics of this fascia are still not widely known among head and neck surgeons. Moreover, the SMAS is generally located at the parotid and cheek regions and divides facial fat into superficial and deep layers. The SMAS connects to the superficial temporal fascia cranially and to the platysma caudally. The frontal muscle and the peripheral part of the orbicularis oculi are also in the same plane. The exact expanse of the SMAS in the face is controversial. Some authors claimed that the SMAS exists in the upper lip, whereas others denied the continuity of the SMAS to the superficial temporal fascia in a histological study. There are various other opinions regarding SMAS aside from those mentioned above. The concept of the SMAS is very important for facial soft tissue surgeries because the SMAS is a good surgical landmark to avoid facial nerve injuries. Therefore, this article summarized SMAS from an anatomical point of view.

Dietary nitrate supplementation increases nitrate and nitrite concentrations in human skin interstitial fluid.

Acute dietary nitrate (NO3-) supplementation can increase [NO3-], but not nitrite ([NO2-]), in human skeletal muscle, though its effect on [NO3-] and [NO2-] in skin remains unknown. In an independent group design, 11 young adults ingested 140 mL of NO3--rich beetroot juice (BR; 9.6 mmol NO3-), and 6 young adults ingested 140 mL of a NO3--depleted placebo (PL). Skin dialysate, acquired through intradermal microdialysis, and venous blood samples were collected at baseline and every hour post-ingestion up to 4 h to assess dialysate and plasma [NO3-] and [NO2-]. The relative recovery rate of NO3- and NO2- through the microdialysis probe (73.1% and 62.8%), determined in a separate experiment, was used to estimate skin interstitial [NO3-] and [NO2-]. Baseline [NO3-] was lower, whereas baseline [NO2-] was higher in the skin interstitial fluid relative to plasma (both P < 0.001). Acute BR ingestion increased [NO3-] and [NO2-] in the skin interstitial fluid and plasma (all P < 0.001), with the magnitude being smaller in the skin interstitial fluid (e.g., 183 ± 54 vs. 491 ± 62 µM for Δ[NO3-] from baseline and 155 ± 190 vs. 217 ± 204 nM for Δ[NO2-] from baseline at 3 h post BR ingestion, both P ≤ 0.037). However, due to the aforementioned baseline differences, skin interstitial fluid [NO2-] post BR ingestion was higher, whereas [NO3-] was lower relative to plasma (all P < 0.001). These findings extend our understanding of NO3- and NO2- distribution at rest and indicate that acute BR supplementation increases [NO3-] and [NO2-] in human skin interstitial fluid.

A case of vasoactive intestinal peptide-secreting tumor (VIPoma) arising from MEN1 inactivation which recurred 15 years after the initial resection.

Vasoactive intestinal peptide-secreting tumors (VIPomas) are extremely rare functional pancreatic neuroendocrine neoplasms (p-NENs) characterized by watery diarrhea, hypokalemia, and achlorhydria. Here, we report the case of a 51-year-old female patient with VIPoma that recurred after a long-term disease-free interval. This patient had been asymptomatic for approximately 15 years after the initial curative surgery for pancreatic VIPoma, with no metastasis. The patient underwent a second curative surgery for the locally recurrent VIPoma. Whole-exome sequencing of the resected tumor revealed a somatic mutation in MEN1, which is reportedly responsible not only for multiple endocrine neoplasia type 1 (MEN1) syndrome but also sporadic p-NENs. Symptoms were controlled with lanreotide before and after surgery. The patient is alive with no relapse following 14 months after surgery. This case demonstrates the importance of long-term observation of patients with VIPoma.

Differences in the prefrontal cortex responses of healthy young men performing either water-based or land-based exercise at light to moderate intensity.

Cerebral blood flow increases more during water-based exercise than land-based exercise owing to the effects of end-tidal CO2 (PETCO2) and mean arterial pressure (MAP) changes due to water immersion. However, it is unclear whether oxygenated hemoglobin (oxy-Hb) concentrations in the prefrontal cortex (PFC) are increased more by water-based or land-based exercise. We hypothesized that oxy-Hb concentrations in the PFC are higher during water-based exercise than land-based exercise when the exercise intensity is matched. To test this hypothesis, 10 healthy participants (age: 24.2 ± 1.7 years; height: 1.75 ± 0.04 m; weight: 69.5 ± 5.2 kg) performed light- to moderate-intensity cycling exercise in water (water-based cycling (WC); chest-high water at 30 °C) and on land (LC). Stroke volume, cardio output, heart rate, MAP, respiratory rate, PETCO2, and oxy-Hb in the PFC were assessed during 15 min of exercise, with exercise intensity increased every 5 min. Both WC and LC significantly increased oxy-Hb concentrations in the PFC as exercise intensity was increased (intensity effect: p < 0.001). There was no significant difference in oxy-Hb concentrations during WC and LC in most prefrontal areas, although significant differences were found in areas corresponding to the left dorsolateral PFC (exercise effect: p < 0.001). Thus, WC and LC increase oxy-Hb concentrations in the PFC in a similar manner with increasing exercise intensity, but part of the PFC exhibits enhanced oxy-Hb levels during WC. The neural response of the PFC may differ during water-based and land-based exercise owing to differences in external information associated with water immersion.