A reliable enzyme-linked immunosorbent assay for the determining of sesame proteins in raw food ingredients and in processed foods.

Sesame is a frequent cause of adverse food reactions in allergic patients. We developed a novel sandwich enzyme-linked immunosorbent assay (ELISA) using two monoclonal antibodies and a unique extraction buffer for the detection and quantification of sesame proteins in processed foods and in raw food ingredients to clarify the validity of sesame labeling and for precautionary allergen labeling. The developed sandwich ELISA method is highly specific for sesame proteins. The limit of detection (LOD) and limit of quantification (LOQ) are 0.013 µg/g and 0.025 µg/g, respectively. The recoveries for incurred food samples, such as dressing, breads, sauce and pudding, ranged from 67 % to 81 %, while the repeatability and reproducibility coefficients of variation were less than 4.7 % and 4.5 %, respectively. The developed method has applicability for food products and is a reliable tool for the detection of hidden sesame proteins in raw food ingredients and in processed foods.

Balance of antiperitoneal adhesion, hemostasis, and operability of compressed bilayer ultrapure alginate sponges.

In surgery, both antiperitoneal adhesion barriers and hemostats with high efficiency and excellent handling are necessary. However, antiadhesion and hemostasis have been examined separately. In this study, six different ultrapure alginate bilayer sponges with thicknesses of 10, 50, 100, 200, 300, and 500 µm were fabricated via lyophilization and subsequent mechanical compression. Compression significantly enhanced mechanical strength and improved handling. Furthermore, it had a complex effect on dissolution time and contact angle. Therefore, the 100 µm compressed sponge showed the highest hemostatic activity in the liver bleeding model in mice, whereas the 200 µm sponge demonstrated the highest antiadhesion efficacy among the compressed sponges in a Pean crush hepatectomy-induced adhesion model in rats. For the first time, we systematically evaluated the effect of sponge compression on foldability, fluid absorption, mechanical strength, hemostatic effect, and antiadhesion properties. The optimum thickness of an alginate bilayer sponge by compression balances antiperitoneal adhesion and hemostasis simultaneously.

Effect of 2-Weeks Ischemic Preconditioning on Exercise Performance: A Pilot Study.

An acute bout of ischemic preconditioning (IPC) has been reported to increase exercise performance. Nevertheless, the ineffectiveness of acute IPC on exercise performance has also been reported. Similarly, the effect of a shot-term intervention of IPC on exercise performance remains controversial in previous studies. In this study, we examined the effects of short-term IPC intervention on whole and local exercise performances and its-related parameters. Ten healthy young males undertook a 2-weeks IPC intervention (6 days/weeks). The IPC applied to both legs with three episodes of a 5-min ischemia and 5-min reperfusion cycle. Whole-body exercise performance was assessed by peak O2 consumption (VO2: VO2 peak) during a ramp-incremental cycling test. Local exercise performance was assessed by time to task failure during a knee extensor sustained endurance test. A repeated moderate-intensity cycling test was performed to evaluate dynamics of pulmonary VO2 and muscle deoxygenation. The knee extensor maximal voluntary contraction and quadriceps femoris cross-sectional area measurements were performed to explore the potentiality for strength gain and muscle hypertrophy. The whole-body exercise performance (i.e., VO2 peak) did not change before and after the intervention (P = 0.147, Power = 0.09, Effect size = 0.21, 95% confidence interval: -0.67, 1.09). Moreover, the local exercise performance (i.e., time to task failure) did not change before and after the intervention (P = 0.923, Power = 0.05, Effect size = 0.02, 95% confidence interval: -0.86, 0.89). Furthermore, no such changes were observed for all parameters measured using a repeated moderate-intensity cycling test and knee extensor strength and quadriceps femoris size measurements. These findings suggest that a 2-weeks IPC intervention cannot increase whole-body and local exercise performances, corresponding with ineffectiveness on its-related parameters in healthy young adults. However, the statistical analyses of changes in the measured parameters in this study showed insufficient statistical power and sensitivity, due to the small sample size. Additionally, this study did not include control group(s) with placebo and/or nocebo. Therefore, further studies with a larger sample size and control group are required to clarify the present findings.

Construction and characterization of a functional chimeric laccase from metagenomes suitable as a biocatalyst.

Screening of gene-specific amplicons from metagenomes (S-GAM) is an efficient technique for the isolation of homologous genes from metagenomes. Using the S-GAM approach, we targeted multi-copper oxidase (MCO) genes including laccase and bilirubin oxidase (BOX) in soil and compost metagenomes, and successfully isolated novel MCO core regions. These core enzyme genes shared approximately 70% identity with that of the putative MCO from Micromonospora sp. MP36. According to the principle of S-GAM, the N- and C-terminal regions of the deduced products of the mature gene come from the known parent gene, which should be homologous and compatible with the target gene. We constructed two different MCO hybrid genes using Bacillus subtilis BOX and Micromonospora sp. MP36 MCO, to give Bs-mg-mco and Mic-mg-mco, respectively. The constructed chimeric MCO genes were fused with the maltose-binding protein (MBP) gene at the N-terminus for expression in Escherichia coli cells. We found that MBP-Mic-mg-MCO/Mic-mg-MCO possessed the characteristic properties of laccase, although MBP-Bs-mg-MCO had no activity. This novel laccase (Mic-mg-MCO) demonstrated unique substrate specificity, sufficient activity at neutral pH, and high thermal stability, which are suitable properties for its use as a laccase biocatalyst.

Overcoming thickened pathological skin in psoriasis via iontophoresis combined with tight junction-opening peptide AT1002 for intradermal delivery of NF-κB decoy oligodeoxynucleotide.

Transdermal delivery of nucleic acid therapeutics has been demonstrated to be effective for psoriasis treatment. We previously reported the utility of iontophoresis (IP) using weak electric current (0.3-0.5 mA/cm2) for intradermal delivery of nucleic acid therapeutics via weak electricity-mediated intercellular junction cleavage, and subsequent exertion of nucleic acid function. However, the thickened pathological skin in psoriasis hampers permeation of IP-administered macromolecules. Thus, approaches are needed to more strongly cleave intercellular spaces and overcome the psoriatic skin barrier. Herein, we applied a combination of tight junction-opening peptide AT1002 with IP, as synergistic effects of weak electricity-mediated intercellular junction cleavage and the tight junction-opening ability of AT1002 may help overcome thickened psoriatic skin and facilitate macromolecule delivery. Pretreatment with IP of an AT1002 analog exhibiting positively-charged moieties before fluorescence-labeled oligodeoxynucleotide IP resulted in the oligodeoxynucleotide permeation into psoriatic skin, whereas IP of the oligodeoxynucleotide alone did not. Moreover, psoriasis-induced upregulation of inflammatory cytokine mRNA levels was significantly suppressed by NF-κB decoy oligodeoxynucleotide IP combined with the AT1002 analog, resulting in amelioration of epidermis hyperplasia. These results suggest that synergistic effects of IP and an AT1002 analog can overcome thickened psoriatic skin and enable intradermal delivery of NF-κB decoy oligodeoxynucleotide for psoriasis treatment.

Laser vaporization of the cervix is associated with an increased risk of preterm birth and rapid labor progression in subsequent pregnancies.

PURPOSE: Laser vaporization of the cervix is an established method of treating cervical intra-epithelial neoplasia, but its effect on subsequent pregnancies remains controversial. The aim of this study was to investigate pregnancy outcomes after laser vaporization. METHODS: We conducted a retrospective study involving women who delivered live singletons between 2012 and 2019 in a tertiary hospital. The risks of adverse pregnancy outcomes after laser vaporization of the cervix were assessed using a multivariate regression model. The primary outcome was the adjusted odds ratio for preterm births. We also evaluated the course of labor progression, duration of labor, risk of emergency cesarean deliveries, and the risk of cervical laceration as secondary outcomes. RESULTS: In total, 3359 women were analyzed in this study. The risk of preterm birth was significantly higher in pregnancies after laser vaporization of the cervix (adjusted odds ratio [AOR] 1.84, 95% confidence interval [95% CI] 1.06-3.20; p = 0.030). The duration of the first stage of labor was significantly shorter in the post-treatment group (median 255 min vs. 355 min; p = 0.0049). We did not observe significant differences in the duration of the second stage of labor (median 21 min vs 20 min; p = 0.507) or the rates of other obstetric events, including emergency cesarean deliveries (AOR 0.736; 95% CI 0.36-1.50; p = 0.400) and cervical laceration (AOR 0.717; 95% CI 0.22-2.35; p = 0.582). CONCLUSION: Laser vaporization of the cervix is associated with an increased risk of preterm births and a shorter duration of the first stage of labor in subsequent pregnancies. Careful consideration is necessary when selecting a method of treatment for the uterine cervix of patients wishing future pregnancies.

Post-translational suppression of the high affinity IgE receptor expression on mast cells by an intestinal bacterium.

Mast cells, which express the high-affinity IgE receptor (FcεRI) on their surface, play a crucial role in inducing allergic inflammation. Since mast cells are activated by crosslinking of FcεRI with IgE and allergens, the cell surface expression level of FcεRI is an important factor in determining the sensitivity to allergens. Recently, the involvement of gut microbiota in the prevalence and regulation of allergy has attracted attention but the precise underlying mechanisms are not fully understood. In this study, the effect of intestinal bacteria on cell surface expression of FcεRI was examined. Bacteroides acidifaciens type A 43 specifically suppressed cell surface expression of FcεRI on mouse bone marrow-derived mast cells (BMMCs) without reduction in FcεRI α and ß-chain mRNA and total protein expression. The suppressive effect required sustained exposure to this bacterium, with a corresponding reduction in Erk activation. Inhibition of Erk decreased cell surface distribution of FcεRI in BMMCs, at least in part, through facilitated endocytosis of FcεRI. These results indicate that B. acidifaciens type A 43 suppresses cell surface expression of FcεRI on mast cells in a post-translational manner via inhibition of Erk. The suppression of FcεRI expression on mast cells by specific bacteria might be the underlying mechanism involved in the regulation of allergy by gut microbiota.

Retention and diffusion characteristics of oligonucleotides in a solid phase with polymer grafted anion-exchanger.

In the chromatographic separation process of oligonucleotides (ONs), mechanistic understanding of their binding and diffusion processes is of significant importance to determine operating conditions in a fast and robust way. In this work, we determined the number of binding sites and the diffusivities of ONs in a polymer grafted anion exchange chromatography through linear gradient experiments (LGE) being carried out at selected four to five gradient slopes. Synthetic poly (T)s with length ranging from 3 to 90-mer were employed as a model of an antisense oligonucleotide with typical lengths of 10 - 30 bases. Comparison of the retention was also conducted between the grafted anion exchanger with a conventional ligand and an anion monolith disk. For the ONs up to 50 bases, the number of binding sites determined can be correlated with the length of ONs, and the grafted resin showed a better diffusion and narrower peak width compared to the nongrafted one. The retention behavior became similar for porous media when the longer ONs (> 50mer) were applied. The results obtained suggest that antisense ONs can be separated with grafted ligands without sacrificing mass transfer properties.

Work volume is an important variable in determining the degree of inhibitory control improvements following resistance exercise.

We previously determined that improvement in cognitive inhibitory control (IC) immediately after localized resistance exercise was greater for high-intensity resistance exercise (HRE) than for low-intensity resistance exercise (LRE). However, our previous study used the same total repetitions (i.e., same repetitions per set) between HRE and LRE; therefore, the difference in postexercise IC improvement might be due to a difference in work volume (i.e., intensity × total repetitions). In this study, we compared the effect of high-volume (HV)-LRE to that of volume-matched HRE on postexercise IC improvements. Twenty-two healthy, young males performed both HV-LRE and HRE in a crossover design. Exercise loads for HV-LRE and HRE were set at 35% and 70% of one-repetition maximum, respectively. The bilateral knee extension exercises for HV-LRE and HRE were programmed for six sets with 20 and 10 repetitions, respectively, per set. IC was measured using the color-word Stroop task (CWST) at six time points; baseline, pre-exercise, immediate postexercise, and every 10 min during the 30-min postexercise recovery period. The reverse-Stroop interference score decreased significantly immediately after HV-LRE and HRE compared with that before each exercise (decreasing rate >34 and >38%, respectively, vs. baseline and pre-exercise; all ps < .05), and the decreased score remained significant until 20 min after both protocols (decreasing rate >40 and >38%, respectively, vs. baseline and pre-exercise; all ps < .05). The degree of the postexercise IC improvements did not differ significantly between the two protocols. These findings suggest that HV-LRE improves IC in a similar manner to volume-matched HRE.

Non-invasive delivery of biological macromolecular drugs into the skin by iontophoresis and its application to psoriasis treatment.

Biological macromolecular drugs, such as antibodies and fusion protein drugs, have been widely employed for the treatment of various diseases. Administration routes are typically via invasive intravenous or subcutaneous injection with needles; the latter is challenging for applications involving inflamed skin (e.g., psoriasis) due to concerns of expansion of inflammation. As a method of non-invasive transdermal drug delivery, we previously demonstrated that iontophoresis (IP) using weak electric current (0.3-0.5 mA/cm2) enables transdermal permeation of hydrophilic macromolecules, such as small interfering RNA and nanoparticles into the skin, and subsequent exertion of their functions. The underlying mechanism was revealed to be via intercellular junction cleavage by cellular signaling activation initiated by Ca2+ influx. Based on these findings, in the present study, we hypothesized that non-invasive intradermal delivery of biological macromolecular drugs could be efficiently achieved via IP. Fluorescence of FITC-labeled IgG antibody was broadly observed in the skin after IP administration (0.4 mA/cm2 for 1 h) and extended from the epidermis to the dermis layer of hairless rats; passive antibody diffusion was not observed. In imiquimod-induced psoriasis model rats, antibodies were also delivered via IP into inflamed skin tissue. Additionally, upregulation of interleukin-6 mRNA levels, which is related to pathological progression of psoriasis, was significantly inhibited by IP of the anti-tumor necrosis factor-α drug etanercept, but not by its subcutaneous injection. Importantly, IP administration of etanercept significantly ameliorated epidermis hyperplasia, a symptom of psoriasis. Taken together, the present study is the first to demonstrate that IP can be applied as a non-invasive and efficient intradermal drug delivery technology for biological macromolecular drugs.

Self-selected music-induced reduction of perceived exertion during moderate-intensity exercise does not interfere with post-exercise improvements in inhibitory control.

Acute aerobic exercise improves inhibitory control (IC). This improvement is often associated with increases in perceived exertion during exercise. However, listening to music during aerobic exercise mitigates an exercise-induced increase in perceived exertion. Thus, it is hypothesized that such effects of music may interfere with exercise-induced improvements in IC. To test this hypothesis, we examined the effect of music on post-exercise IC improvements that were induced by moderate-intensity exercise. Fifteen healthy young men performed cycle ergometer exercise with music or non-music. The exercise was performed using a moderate-intensity of 60% of VO2 peak for 30 min. The music condition was performed while listening to self-selected music. The non-music condition involved no music. To evaluate IC, the Stroop task was administered before exercise, immediately after exercise, and during the 30-min post-exercise recovery period. The rate of perceived exertion immediately before moderate-intensity exercise completed was significantly lower in music condition than in non-music condition. The IC significantly improved immediately after exercise and during the post-exercise recovery period compared to before exercise in both music and non-music conditions. The post-exercise IC improvements did not significantly differ between the two conditions. These findings indicate that self-selected music-induced mitigation of the increase in perceived exertion during moderate-intensity exercise dose not interfere with exercise-induced improvements in IC. Therefore, we suggest that listening to music may be a beneficial strategy in mitigating the increase in perceived exertion during aerobic exercise without decreasing the positive effects on IC.

Flavanol-rich cocoa consumption enhances exercise-induced executive function improvements in humans.

OBJECTIVE: Aerobic exercise is known to acutely improve cognitive functions, such as executive function (EF) and memory function (MF). Additionally, consumption of flavanol-rich cocoa has been reported to acutely improve cognitive function. The aim of this study was to determine whether high cocoa flavanol (CF; HCF) consumption would enhance exercise-induced improvement in cognitive function. To test this hypothesis, we examined the combined effects of HCF consumption and moderate-intensity exercise on EF and MF during postexercise recovery. METHODS: Ten healthy young men received either an HCF (563 mg of CF) or energy-matched low CF (LCF; 38 mg of CF) beverage 70 min before exercise in a single-blind counterbalanced manner. The men then performed moderate-intensity cycling exercise at 60% of peak oxygen uptake for 30 min. The participants performed a color-word Stroop task and face-name matching task to evaluate EF and MF, respectively, during six time periods throughout the experimental session. RESULTS: EF significantly improved immediately after exercise compared with before exercise in both conditions. However, EF was higher after HCF consumption than after LCF consumption during all time periods because HCF consumption improved EF before exercise. In contrast, HCF consumption and moderate-intensity exercise did not improve MF throughout the experiment. CONCLUSION: The present findings demonstrated that HCF consumption before moderate-intensity exercise could enhance exercise-induced improvement in EF, but not in MF. Therefore, we suggest that the combination of HCF consumption and aerobic exercise may be beneficial for improving EF.

An acute bout of localized resistance exercise can rapidly improve inhibitory control.

The positive effect of acute resistance exercise on executive function, such as inhibitory control (IC), is poorly understood. Several previous studies have demonstrated this effect using whole-body resistance exercise. However, it remains unclear whether localized resistance exercise performed using only limited muscle groups could also acutely improve IC. Thus, the present study examined the effect of an acute bout of localized resistance exercise on IC. Twelve healthy men performed a color-word Stroop task (CWST) before and immediately after the experimental conditions, which consisted of 2 resistance exercises and a resting control (CON). Bilateral knee extension was used to create 2 resistance exercise conditions: light-intensity resistance exercise (LRE) and high-intensity resistance exercise (HRE) conditions, which were 40% and 80% of one-repetition maximum, respectively. The resistance exercise session was programmed for 6 sets with 10 repetitions per set. The CWST-measured IC was significantly improved immediately after both LRE and HRE, but it did not improve immediately after CON. However, the improved IC was significantly greater in HRE than in LRE. The present findings showed that IC could be rapidly improved by an acute bout of localized resistance exercise, especially with high-intensity. Therefore, we suggest that in addition to whole-body resistance exercise, localized resistance exercise performed using limited muscle groups may be sufficient for improving IC.

Applicability of ultrasonography for evaluating trunk muscles size in athletes: a study focused on baseball batters.

[Purpose] Recently, we demonstrated that the thicknesses of trunk muscles measured using ultrasonography were correlated strongly with the cross-sectional areas measured using magnetic resonance imaging in untrained subjects. To further explore the applicability of ultrasonography in the clinical setting, the present study examined the correlation between ultrasonography-measured thicknesses and magnetic resonance imaging-measured cross-sectional areas of trunk muscles in athletes with trained trunk muscles. [Subjects and Methods] The thicknesses and cross-sectional areas at total 10 sites of the bilateral sides of the upper, central, and lower parts of the rectus abdominis, abdominal wall, and multifidus lumborum in 30 male baseball batters were measured. [Results] Overall thicknesses and cross-sectional areas of the trunk muscles in baseball batters were higher than those in untrained subjects who participated in our previous study. The ultrasonography-measured thicknesses at all 10 sites of the trunk muscles correlated highly with the magnetic resonance imaging-measured cross-sectional areas in baseball batters. [Conclusion] These results suggest that the thicknesses of the trunk muscles measured using ultrasonography can be used as a surrogate marker for the cross-sectional area measured using magnetic resonance imaging, in athletes who have larger trunk muscles than that of untrained subjects.

Applicability of ultrasonography for evaluating trunk muscle size: a pilot study.

[Purpose] Ultrasonography (US) is widely applied to measure the muscle size in the limbs, as it has relatively high portability and is associated with low costs compared with large clinical devices such as magnetic resonance imaging (MRI). However, the applicability of US for evaluating trunk muscle size is poorly understood. This study aimed to examine whether US-measured muscle thickness (MT) in the trunk abdominal and back muscles correlated with MT and muscle cross-sectional area (MCSA) measured by MRI. [Subjects and Methods] Twenty-four healthy young males participated in this study. The MT and MCSA in the subjects were measured by US and MRI in a total of 10 sites, including the bilateral sides of the rectus abdominis (upper, central, and lower parts), abdominal wall, and multifidus lumborum. [Results] The interclass correlation coefficients of US-measured MT on the total 10 sites showed excellent values (n=12, 0.919 to 0.970). The US-measured MT significantly correlated with the MRI-measured MT (r=0.753 to 0.963) and MCSA (r=0.634 to 0.821). [Conclusion] US-measured MT could represent a surrogate for muscle size measured by MRI. The application of US for evaluating trunk muscle size may be a useful tool in the clinical setting.

Relationships between Bat Swing Speed and Muscle Thickness and Asymmetry in Collegiate Baseball Players.

The purpose of the present study was to examine the relationships between bat swing speed (BSS), muscle thickness, and muscle thickness asymmetry in collegiate baseball players. Twenty-four collegiate baseball players participated in this study. Maximum BSS in hitting a teed ball was measured using a motion capture system. The muscle thicknesses of the trunk (upper abdominal rectus, central abdominal rectus, lower abdominal rectus, abdominal wall, and multifidus lumborum), upper limb, and lower limb were measured using a B-mode ultrasonography. Lateral asymmetry between each pair of muscles was determined as the ratio of the thickness of the dominant side to that of the non-dominant side. Statistically significant positive correlations were observed between BSS and muscle thicknesses of the abdominal wall and multifidus lumborum on the dominant side (r = 0.426 and 0.431, respectively; p < 0.05), whereas only trends against this significance were observed between BSS and muscle thicknesses on the non-dominant side. No statistical correlations were found between BSS and the lateral asymmetry of any muscles. These findings indicate the importance of the trunk muscles for bat swing, and the lack of association between BSS and lateral asymmetry of muscle size.

Impact of Exercise Intensity and Duration on Postexercise Executive Function.

PURPOSE: The effect of exercise volume represented by exercise intensity and duration on postexercise executive function (EF) improvement remains unclear. In the present study, involving two volume-controlled evaluations, we aimed to compare acute exercise protocols with differing intensities and durations to establish an effective exercise protocol for improving EF. METHODS: In study 1, 12 healthy male subjects performed cycle ergometer exercise, based on a low-intensity (LI) protocol for 20 min (LI20), moderate-intensity (MI) protocol for 20 min (MI20), and MI20 volume-matched LI protocol for 40 min (LI40). The exercise intensities for the LI and MI were set at 30% and 60% of peak oxygen consumption, respectively. In study 2, 15 healthy male subjects performed MI exercise for 10 min (MI10), MI20, and 40 min (MI40). To evaluate the EF, the color-word Stroop task was administrated before exercise, immediately after exercise, and during the 30-min postexercise recovery. RESULTS: In study 1, postexercise EF improvement was sustained for a longer duration after MI20 than after LI40 and was sustained for a longer duration after LI40 than after LI20. In study 2, although there was no significant difference in post-MI exercise EF improvement, the magnitude of difference in the EF between preexercise and 30-min postexercise recovery period was moderately larger in MI40, but not in MI10 and MI20, indicating that the EF improvement during postexercise recovery could be sustained after MI40. CONCLUSION: The present findings showed that postexercise EF improvement could be prolonged after MI exercise with a moderate duration compared with volume-matched LI exercise with a longer duration. In addition, MI exercise with a relatively long duration may slightly prolong the postexercise EF improvement.

Repeated high-intensity interval exercise shortens the positive effect on executive function during post-exercise recovery in healthy young males.

A single bout of aerobic exercise improves executive function (EF), but only for a short period. Compared with a single bout of aerobic exercise, we recently found that high-intensity interval exercise (HIIE) could maintain a longer improvement in EF. However, the mechanism underlying the effect of different exercise modes on the modifications of EF remains unclear. The purpose of the current investigation was to test our hypothesis that the amount of exercise-induced lactate production and its accumulation affects human brain function during and after exercise, thereby affecting post-exercise EF. Ten healthy male subjects performed cycle ergometer exercise. The HIIE protocol consisted of four 4-min bouts at 90% peak VO2 with a 3-min active recovery period at 60% peak VO2. The amount of lactate produced during exercise was manipulated by repeating the HIIE twice with a resting period of 60min between the 1st HIIE and 2nd HIIE. To evaluate EF, a color-word Stroop task was performed, and reverse-Stroop interference scores were obtained. EF immediately after the 1st HIIE was significantly improved compared to that before exercise, and the improved EF was sustained during 40min of the post-exercise recovery. However, for the 2nd HIIE, the improved EF was sustained for only 10min of the post-exercise recovery period, despite the performance of the same exercise. In addition, during and following HIIE, the glucose and lactate accumulation induced by the 2nd HIIE was significantly lower than that induced by the 1st HIIE. Furthermore, there was an inverse relationship between lactate and EF by plotting the changes in lactate levels against changes in EF from pre-exercise during the late phase of post-exercise recovery. These findings suggested the possibility that repeated bouts of HIIE, which decreases lactate accumulation, may dampen the positive effect of exercise on EF during the post-exercise recovery.

Greater impact of acute high-intensity interval exercise on post-exercise executive function compared to moderate-intensity continuous exercise.

Aerobic moderate-intensity continuous exercise (MCE) can improve executive function (EF) acutely, potentially through the activation of both physiological and psychological factors. Recently, high-intensity interval exercise (HIIE) has been reported to be more beneficial for physical adaptation than MCE. Factors for EF improvement can potentially be more enhanced by HIIE than by MCE; but the effects of HIIE on EF remain unknown. Therefore, we aimed to examine to what extent HIIE impacts post-exercise EF immediately after exercise and during post-exercise recovery, compared with traditional MCE. Twelve healthy male subjects performed cycle ergometer exercise based on either HIIE or MCE protocols in a randomized and counterbalanced order. The HIIE protocol consisted of four 4-min bouts at 90% of peak VO2 with 3-min active recovery at 60% of peak VO2. A volume-matched MCE protocol was applied at 60% of peak VO2. To evaluate EF, a color-words Stroop task was performed pre- and post-exercise. Improvement in EF immediately after exercise was the same for the HIIE and MCE protocols. However, the improvement of EF by HIIE was sustained during 30 min of post-exercise recovery, during which MCE returned to the pre-exercise level. The EF response in the post-exercise recovery was associated with changes in physiological and psychological responses. The present findings showed that HIIE and MCE were capable of improving EF. Moreover, HIIE could prolong improvement in EF during post-exercise recovery. For the first time, we suggest that HIIE may be more effective strategy than MCE for improving EF.

Ischemic preconditioning accelerates muscle deoxygenation dynamics and enhances exercise endurance during the work-to-work test.

Ischemic preconditioning (IPC) improves maximal exercise performance. However, the potential mechanism(s) underlying the beneficial effects of IPC remain unknown. The dynamics of pulmonary oxygen uptake (VO2) and muscle deoxygenation during exercise is frequently used for assessing O2 supply and extraction. Thus, this study examined the effects of IPC on systemic and local O2 dynamics during the incremental step transitions from low- to moderate- and from moderate- to severe-intensity exercise. Fifteen healthy, male subjects were instructed to perform the work-to-work cycling exercise test, which was preceded by the control (no occlusion) or IPC (3 × 5 min, bilateral leg occlusion at >300 mmHg) treatments. The work-to-work test was performed by gradually increasing the exercise intensity as follows: low intensity at 30 W for 3 min, moderate intensity at 90% of the gas exchange threshold (GET) for 4 min, and severe intensity at 70% of the difference between the GET and VO2 peak until exhaustion. During the exercise test, the breath-by-breath pulmonary VO2 and near-infrared spectroscopy-derived muscle deoxygenation were continuously recorded. Exercise endurance during severe-intensity exercise was significantly enhanced by IPC. There were no significant differences in pulmonary VO2 dynamics between treatments. In contrast, muscle deoxygenation dynamics in the step transition from low- to moderate-intensity was significantly faster in IPC than in CON (27.2 ± 2.9 vs. 19.8 ± 0.9 sec, P < 0.05). The present findings showed that IPC accelerated muscle deoxygenation dynamics in moderate-intensity exercise and enhanced severe-intensity exercise endurance during work-to-work test. The IPC-induced effects may result from mitochondrial activation in skeletal muscle, as indicated by the accelerated O2 extraction.