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1.
Cereb Circ Cogn Behav ; 7: 100363, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39252851

RESUMEN

The aim was to examine the effects of modalities of acute resistance exercise (RE) on cognition and hemodynamics including internal carotid artery (ICA) blood flow (BF). Twenty adults completed familiarization and experimental visits. One-repetition maximum (1RM) for bilateral leg extension was quantified, and baseline executive functioning was determined from three run-in visits. Subsequent visits included three randomized, volume-equated, acute exercise bouts of 30 %1RM+blood flow restriction (BFR), 30 %1RM, and 70 %1RM. Both 30 %1RM trials completed four sets of exercise (1 × 30, 3 × 15), and the 70 %1RM condition completed four sets of 8 repetitions. BFR was induced with 40 % of the pressure to occlude the femoral arteries. 11 min following each exercise, participants completed the Stroop and Shifting Attention Tests. Baseline and post-exercise values were used to calculate change scores. The resulting mean change scores were evaluated with mixed factorial ANOVAs. A p≤0.05 was considered significant. All measured outcome variables increased in response to exercise. The ANOVAs for cognitive scores indicated no significant (p>0.05) interactions. For cognitive flexibility and executive function index, there were main effects of Sex. Change scores of the females were significantly greater than the males for cognitive flexibility (7.6 ± 5.9 vs. -2.6 ± 8.4 au; p=0.007) and executive function index (7.4 ± 4.6 vs. -2.5 ± 6.5 au; p=0.001). For ICA BF, there was no significant interaction or any main effect. The females exhibited a smaller exercise-induced increase in blood pressure compared to the males (17.7 ± 5.9 vs. 11.0 ± 4.1 mmHg; p=0.010). Each RE modality yielded acute improvements in cognition, but only for females. There were no cognitive improvements related to BFR such that each RE bout yielded similar results.

2.
Res Q Exerc Sport ; : 1-11, 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39231592

RESUMEN

Purpose: There is conflicting evidence related to the prevalence and magnitude of exercise-induced muscle damage (EIMD) following four sets to volitional failure with BFR (BFR-F) or 75 total repetitions with BFR (1 × 30, 3 × 15, BFR-75). The purpose of this investigation was to examine muscle swelling, peak torque, and neuromuscular responses following BFR-75 and BFR-F. Methods: Thirteen untrained women completed unilateral isokinetic (120°s-1) leg extensions concentric-eccentric at 30% of their maximal voluntary isometric contraction (MVIC) using BFR-75 and BFR-F protocols, separated by 15 minutes. Ultrasound was used to assess muscle thickness, cross sectional area, and echo intensity of the rectus femoris and vastus lateralis before, 0-, 24-, 48-, 72-, and 96-hours post-exercise. Peak torque and surface electromyography (sEMG) were recorded during MVICs before, 24-, 48-, 72-, and 96-hours post-exercise to determine sEMG amplitude, frequency, and neuromuscular efficiency. Results: There were no differences between conditions. Collapsed across conditions, muscle thickness and cross-sectional area increased at 0-hours for the rectus femoris (2.5 ± 0.4, 2.8 ± 0.4 cm, 10.6 ± 1.8, 12.1 ± 1.8 cm2, respectively) and vastus lateralis (2.1 ± 0.5, 2.5 ± 0.7 cm; 22.2 ± 3.9, 25.1 ± 4.5 cm2, respectively), but returned to baseline at 24-hours. There were no changes in echo intensity, sEMG amplitude, sEMG frequency, or neuromuscular efficiency. MVIC peak torque increased relative to pre-exercise at 24-, 48-, 72-, and 96-hours (159.9 ± 34.9, 171.4 ± 30.1-179.1 ± 35.6 Nm). Conclusion: These results suggest that BFR-75 and BFR-F did not cause EIMD but caused an acute increase in muscle swelling that returned to baseline 24-hours post-exercise.

3.
J Strength Cond Res ; 2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-39178106

RESUMEN

ABSTRACT: Lubiak, SM, Lawson, JE, Gonzalez Rojas, DH, Proppe, CE, Rivera, PM, Hammer, SM, Trevino, MA, Dinyer-McNeely, TK, Montgomery, TR, Olmos, AA, Sears, KN, Bergstrom, HC, Succi, PJ, Keller, JL, and Hill, EC. A moderate blood flow restriction pressure does not affect maximal strength or neuromuscular responses. J Strength Cond Res XX(X): 000-000, 2024-The purpose of this study was to examine the acute effects of blood flow restriction (BFR) applied at 60% of total arterial occlusion pressure (AOP) on maximal strength. Eleven college-aged female subjects completed two testing sessions of maximal unilateral concentric, isometric, and eccentric leg extension muscle actions performed with and without BFR. Separate 3 (mode [isometric, concentric, eccentric]) × 2 (condition [BFR, no BFR]) × 2 (visit [2, 3]) repeated-measures analysis of variances were used to examine mean differences in maximal strength, neuromuscular function, rating of perceived exertion (RPE), and pain. For maximal strength (collapsed across condition and visit), isometric (128.5 ± 22.7 Nm) and eccentric (114.5 ± 35.4 Nm) strength were greater than concentric maximal strength (89.3 ± 22.3 Nm) (p < 0.001-0.041). Muscle excitation relative (%) to isometric non-BFR was greater during the concentric (108.6 ± 31.5%) than during the eccentric (86.7 ± 29.2%) (p = 0.045) assessments but not different than isometric (93.4 ± 17.9%) (p = 0.109) assessments, collapsed across condition and visit. For RPE, there was an interaction such that RPE was greater during non-BFR (4.3 ± 1.7) than during BFR (3.7 ± 1.7) (p = 0.031) during the maximal concentric strength assessments. Furthermore, during maximal strength assessments performed with BFR, isometric RPE (5.8 ± 1.9) was greater than concentric (3.7 ± 1.7) (p = 0.005) and eccentric (4.6 ± 1.9) (p = 0.009) RPE. Finally, pain was greater during the isometric (2.8 ± 2.1 au) than during the concentric (1.8 ± 1.5 au) (p = 0.016), but not eccentric, maximal strength assessments (2.1 ± 1.6 au) (p = 0.126), collapsed across condition and visit. The application of BFR at 60% AOP did not affect concentric, isometric, or eccentric maximal strength or neuromuscular function. Trainers, clinicians, and researchers can prescribe exercise interventions relative to a restricted (when using a moderate AOP) or nonrestricted assessment of maximal strength.

4.
Eur J Appl Physiol ; 2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39162881

RESUMEN

PURPOSE: Resistance exercise can attenuate muscular impairments associated with multiple sclerosis (MS), and blood flow restriction (BFR) may provide a viable alternative to prescribing heavy training loads. The purpose of this investigation was to examine the progression of upper and lower body low-load (30% of one-repetition maximum [1RM]) resistance training (RT) with BFR applied intermittently during the exercise intervals (RT + BFR) versus volume-matched heavy-load (65% of 1RM) RT. METHODS: Men and women with MS (n = 16) were randomly assigned to low-load RT + BFR (applied intermittently) or heavy-load RT and completed 12 weeks (2 × /week) of RT that consisted of bilateral chest press, seated row, shoulder press, leg press, leg extension, and leg curl exercises. Exercise load, tonnage, and rating of perceived exertion were assessed at baseline and every 6 weeks. RESULTS: Training load increased to a greater extent and sometimes earlier for RT + BFR (57.7-106.3%) than heavy-load RT (42.3-54.3%) during chest press, seated row, and leg curl exercises, while there were similar increases (63.5-101.1%) for shoulder press, leg extension, and leg press exercises. Exercise tonnage was greater across all exercises for RT + BFR than heavy-load RT, although tonnage only increased during the chest press (70.7-80.0%) and leg extension (89.1%) exercises. Perceptions of exertion (4.8-7.2 au) and compliance (97.9-99.0%) were similar for both interventions. CONCLUSION: The training-induced increases in load, high compliance, and moderate levels of exertion suggested that RT + BFR and heavy-load RT are viable interventions among people with MS. RT + BFR may be a preferred modality if heavy loads are not well tolerated and/or to promote early-phase training responses.

5.
J Strength Cond Res ; 38(7): e349-e358, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38900183

RESUMEN

ABSTRACT: Montgomery, TR Jr, Olmos, A, Sears, KN, Succi, PJ, Hammer, SM, Bergstrom, HC, Hill, EC, Trevino, MA, and Dinyer-McNeely, TK. Influence of blood flow restriction on neuromuscular function and fatigue during forearm flexion in men. J Strength Cond Res 38(7): e349-e358, 2024-To determine the effects of blood flow restriction (BFR) on the mean firing rate (MFR) and motor unit action potential amplitude (MUAPAMP) vs. recruitment threshold (RT) relationships during fatiguing isometric elbow flexions. Ten men (24.5 ± 4.0 years) performed isometric trapezoidal contractions at 50% maximum voluntary contraction to task failure with or without BFR, on 2 separate days. For BFR, a cuff was inflated to 60% of the pressure required for full brachial artery occlusion at rest. During both visits, surface electromyography was recorded from the biceps brachii of the dominant limb and the signal was decomposed. A paired-samples t test was used to determine the number of repetitions completed between BFR and CON. ANOVAs (repetition [first, last] × condition [BFR, CON]) were used to determine differences in MFR vs. RT and MUAPAMP vs. RT relationships. Subjects completed more repetitions during CON (12 ± 4) than BFR (9 ± 2; p = 0.012). There was no significant interaction (p > 0.05) between the slopes and y-intercepts during the repetition × condition interaction for MUAPAMP vs. MFR. However, there was a main effect of repetition for the slopes of the MUAPAMP vs. RT (p = 0.041) but not the y-intercept (p = 0.964). Post hoc analysis (collapsed across condition) indicated that the slopes of the MUAPAMP vs. RT during the first repetition was less than the last repetition (first: 0.022 ± 0.003 mv/%MVC; last: 0.028 ± 0.004 mv/%MVC; p = 0.041). Blood flow restriction resulted in the same amount of higher threshold MU recruitment in approximately 75% of the repetitions. Furthermore, there was no change in MFR for either condition, even when taken to task failure. Thus, BFR training may create similar MU responses with less total work completed than training without BFR.


Asunto(s)
Electromiografía , Antebrazo , Contracción Isométrica , Fatiga Muscular , Músculo Esquelético , Flujo Sanguíneo Regional , Humanos , Masculino , Fatiga Muscular/fisiología , Adulto , Contracción Isométrica/fisiología , Antebrazo/irrigación sanguínea , Antebrazo/fisiología , Adulto Joven , Músculo Esquelético/fisiología , Músculo Esquelético/irrigación sanguínea , Flujo Sanguíneo Regional/fisiología , Terapia de Restricción del Flujo Sanguíneo
6.
J Sports Med Phys Fitness ; 64(9): 880-888, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38863419

RESUMEN

BACKGROUND: There is conflicting evidence regarding the presence and magnitude of exercise-induced muscle damage (EIMD) following low-load resistance training with blood flow restriction (LL+BFR), which may be related to the protocol implemented or exercise volume. Therefore, the purpose of this investigation was to examine the effects of a 75 repetition (BFR-75) (1×30, 3×15) and four sets to volitional failure (BFR-4x) protocols on indices of EIMD among untrained men. METHODS: Twelve males with no history of lower-body resistance training during the previous six months volunteered for this investigation. One leg was randomly assigned to BFR-75, and the other to BFR-4x. Participants performed isokinetic, unilateral, concentric-eccentric, leg extension muscle actions at 30% of maximal strength with BFR. Indices of EIMD (limb circumference, perceived muscle soreness, pain pressure threshold [PPT], passive range of motion, and maximal strength [MVIC]) were recorded before exercise and 0, 24, 48, 72, and 96-hours post-exercise for each protocol. RESULTS: There were no significant changes (P>0.05) in limb circumference, PPT, passive range of motion, or MVIC. For both BFR-75 and BFR-4x, perceived muscle soreness increased (P<0.001) similarly 24- (2.5±1.7 AU) and 48-hours (1.9±1.7 AU) post-exercise. CONCLUSIONS: There was an increase in muscle soreness 24-48 hours post-exercise for both conditions, which may be due to metabolic stress, but this did not affect the force-generating capacity of the muscle (MVIC), suggesting minimal EIMD. The conflicting evidence of EIMD following LL+BFR may be related to differences in restriction time or overall exercise time.


Asunto(s)
Fuerza Muscular , Músculo Esquelético , Mialgia , Entrenamiento de Fuerza , Humanos , Masculino , Entrenamiento de Fuerza/métodos , Músculo Esquelético/irrigación sanguínea , Mialgia/fisiopatología , Mialgia/etiología , Fuerza Muscular/fisiología , Adulto Joven , Adulto , Rango del Movimiento Articular/fisiología , Flujo Sanguíneo Regional/fisiología
7.
J Immunother Cancer ; 12(5)2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38702146

RESUMEN

BACKGROUND: T cell checkpoint receptors are expressed when T cells are activated, and modulation of the expression or signaling of these receptors can alter the function of T cells and their antitumor efficacy. We previously found that T cells activated with cognate antigen had increases in the expression of PD-1, and this was attenuated in the presence of multiple toll-like receptor (TLR) agonists, notably TLR3 plus TLR9. In the current report, we sought to investigate whether combining TLR agonists with immune checkpoint blockade can further augment vaccine-mediated T cell antitumor immunity in murine tumor models. METHODS: TLR agonists (TLR3 plus TLR9) and immune checkpoint inhibitors (antibodies targeting PD-1, CTLA-4, LAG-3, TIM-3 or VISTA) were combined and delivered with vaccines or vaccine-activated CD8+T cells to E.G7-OVA or MyC-CaP tumor-bearing mice. Tumors were assessed for growth and then collected and analyzed by flow cytometry. RESULTS: Immunization of E.G7-OVA tumor-bearing mice with SIINFEKL peptide vaccine, coadministered with TLR agonists and αCTLA-4, demonstrated greater antitumor efficacy than immunization with TLR agonists or αCTLA-4 alone. Conversely, the antitumor efficacy was abrogated when vaccine and TLR agonists were combined with αPD-1. TLR agonists suppressed PD-1 expression on regulatory T cells (Tregs) and activated this population. Depletion of Tregs in tumor-bearing mice led to greater antitumor efficacy of this combination therapy, even in the presence of αPD-1. Combining vaccination with TLR agonists and αCTLA-4 or αLAG-3 showed greater antitumor than with combinations with αTIM-3 or αVISTA. CONCLUSION: The combination of TLR agonists and αCTLA-4 or αLAG-3 can further improve the efficacy of a cancer vaccine, an effect not observed using αPD-1 due to activation of Tregs when αPD-1 was combined with TLR3 and TLR9 agonists. These data suggest that optimal combinations of TLR agonists and immune checkpoint blockade may improve the efficacy of human anticancer vaccines.


Asunto(s)
Vacunas contra el Cáncer , Inhibidores de Puntos de Control Inmunológico , Agonistas de los Receptores Toll-Like , Animales , Femenino , Humanos , Ratones , Vacunas contra el Cáncer/inmunología , Vacunas contra el Cáncer/uso terapéutico , Línea Celular Tumoral , Inhibidores de Puntos de Control Inmunológico/farmacología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico
8.
J Biosoc Sci ; : 1-22, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38618934

RESUMEN

RESULTS.: Hispanic children have higher odds of growth stunting than non-Hispanic White children. Native American children die younger and have higher odds of respiratory diseases and porous lesions than Hispanic and non-Hispanic Whites. Rural/urban location does not significantly impact age at death, but housing type does. Individuals who lived in trailers/mobile homes had earlier ages at death. When intersections between housing type and housing location are considered, children who were poor and from impoverished areas lived longer than those who were poor from relatively well-off areas. CONCLUSIONS.: Children's health is shaped by factors outside their control. The children included in this study embodied experiences of social and ELS and did not survive to adulthood. They provide the most sobering example of the harm that social factors (structural racism/discrimination, socioeconomic, and political structures) can inflict.

9.
Physiol Meas ; 45(4)2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38507792

RESUMEN

Objective. Surface mechanomyography (sMMG) can measure oscillations of the activated muscle fibers in three axes (i.e.X,Y, andZ-axes) and has been used to describe motor unit activation patterns (X-axis). The application of blood flow restriction (BFR) is common in exercise studies, but the cuff may restrict muscle fiber oscillations. Therefore, the purpose of this investigation was to examine the acute effects of submaximal, fatiguing exercise with and without BFR on sMMG amplitude in theX,Y, andZ-axes among female participants.Approach. Sixteen females (21 ± 1 years) performed two separate exercise bouts to volitional exhaustion that consisted of unilateral, submaximal (50% maximal voluntary isometric contraction [MVIC]) intermittent, isometric, leg extensions with and without BFR. sMMG was recorded and examined across percent time to exhaustion (%TTE) in 20% increments. Separate 2-way repeated measures ANOVA models were constructed: (condition [BFR, non-BFR]) × (time [20, 40, 60, 80, and 100% TTE]) to examine absolute (m·s-2) and normalized (% of pretest MVIC) sMMG amplitude in theX-(sMMG-X),Y-(sMMG-Y), andZ-(sMMG-Z) axes.Main results. The absolute sMMG-X amplitude responses were attenuated with the application of BFR (mean ± SD = 0.236 ± 0.138 m·s-2) relative to non-BFR (0.366 ± 0.199 m·s-2, collapsed across time) and for sMMG-Y amplitude at 60%-100% of TTE (BFR range = 0.213-0.232 m·s-2versus non-BFR = 0.313-0.445 m·s-2). Normalizing sMMG to pretest MVIC removed most, but not all the attenuation which was still evident for sMMG-Y amplitude at 100% of TTE between BFR (72.9 ± 47.2%) and non-BFR (98.9 ± 53.1%). Interestingly, sMMG-Z amplitude was not affected by the application of BFR and progressively decreased across %TTE (0.332 ± 0.167 m·s-2to 0.219 ± 0.104 m·s-2, collapsed across condition.)Significance. The application of BFR attenuated sMMG-X and sMMG-Y amplitude, although normalizing sMMG removed most of this attenuation. Unlike theXandY-axes, sMMG-Z amplitude was not affected by BFR and progressively decreased across each exercise bout potentially tracking the development of muscle fatigue.


Asunto(s)
Fatiga Muscular , Entrenamiento de Fuerza , Humanos , Femenino , Fatiga Muscular/fisiología , Ejercicio Físico/fisiología , Contracción Isométrica/fisiología , Flujo Sanguíneo Regional , Modalidades de Fisioterapia , Músculo Esquelético/fisiología , Electromiografía , Entrenamiento de Fuerza/métodos
10.
J Musculoskelet Neuronal Interact ; 24(1): 38-46, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38427367

RESUMEN

BFR) applied during sprint interval training (SIT) on performance and neuromuscular function. METHODS: Fifteen men completed a randomized bout of SIT with CBFR, IBFR, and without BFR (No-BFR), consisting of 2, 30-s maximal sprints on a cycle ergometer with a resistance of 7.5% of body mass. Concentric peak torque (CPT), maximal voluntary isometric contraction (MVIC) torque, and muscle thickness (MT) were measured before and after SIT, including surface electromyography (sEMG) recorded during the strength assessments. Peak and mean revolutions per minute (RPM) were measured during SIT and power output was examined relative to physical working capacity at the fatigue threshold (PWCFT). RESULTS: CPT and MVIC torque decreased from pre-SIT (220.3±47.6 Nm and 355.1±72.5 Nm, respectively) to post-SIT (147.9±27.7 Nm and 252.2±45.5 Nm, respectively, all P<0.05), while MT increased (1.77±0.31 cm to 1.96±0.30 cm). sEMG mean power frequency decreased during CPT (-12.8±10.5%) and MVIC (-8.7±10.2%) muscle actions. %PWCFT was greater during No-BFR (414.2±121.9%) than CBFR (375.9±121.9%). CONCLUSION: SIT with or without BFR induced comparable alterations in neuromuscular fatigue and sprint performance across all conditions, without affecting neuromuscular function.


Asunto(s)
Entrenamiento de Intervalos de Alta Intensidad , Músculo Esquelético , Humanos , Masculino , Electromiografía , Contracción Isométrica/fisiología , Fatiga Muscular , Músculo Esquelético/fisiología , Flujo Sanguíneo Regional/fisiología , Torque
11.
Int J Sports Med ; 45(9): 659-671, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38198822

RESUMEN

Skeletal muscle is the largest organ system in the human body and plays critical roles in athletic performance, mobility, and disease pathogenesis. Despite growing recognition of its importance by major health organizations, significant knowledge gaps remain regarding skeletal muscle health and its crosstalk with nearly every physiological system. Relevant public health challenges like pain, injury, obesity, and sarcopenia underscore the need to accurately assess skeletal muscle health and function. Feasible, non-invasive techniques that reliably evaluate metrics including muscle pain, dynamic structure, contractility, circulatory function, body composition, and emerging biomarkers are imperative to unraveling the complexities of skeletal muscle. Our concise review highlights innovative or overlooked approaches for comprehensively assessing skeletal muscle in vivo. We summarize recent advances in leveraging dynamic ultrasound imaging, muscle echogenicity, tensiomyography, blood flow restriction protocols, molecular techniques, body composition, and pain assessments to gain novel insight into muscle physiology from cellular to whole-body perspectives. Continued development of precise, non-invasive tools to investigate skeletal muscle are critical in informing impactful discoveries in exercise and rehabilitation science.


Asunto(s)
Composición Corporal , Músculo Esquelético , Ultrasonografía , Humanos , Músculo Esquelético/fisiología , Biomarcadores , Contracción Muscular/fisiología , Mialgia/fisiopatología
12.
Microbiol Resour Announc ; 13(2): e0108823, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38179906

RESUMEN

We report genomes of nine phages isolated from Actinobacteria Rhodococcus equi NRRL B-16538. Six of these phages belong to actinobacteriophage cluster CR, which otherwise contains Gordonia phages; two form the CF cluster; and one is a singleton. Genome lengths are 62,017-80,980 bp with 63.9%-67.3% GC content.

13.
Eur J Appl Physiol ; 124(6): 1807-1820, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38236301

RESUMEN

PURPOSE: To investigate the effects of blood flow restriction (BFR) on electromyographic amplitude (EMGRMS)-force relationships of the biceps brachii (BB) during a single high-load muscle action. METHODS: Twelve recreationally active males and eleven recreationally active females performed maximal voluntary contractions (MVCs), followed by an isometric trapezoidal muscle action of the elbow flexors at 70% MVC. Surface EMG was recorded from the BB during BFR and control (CON) visits. For BFR, cuff pressure was 60% of the pressure required to completely occlude blood at rest. Individual b (slope) and a terms (gain) were calculated from the log-transformed EMGRMS-force relationships during the linearly increasing and decreasing segments of the trapezoid. EMGRMS during the steady force segment was normalized to MVC EMGRMS. RESULTS: For BFR, the b terms were greater during the linearly increasing segment than the linearly decreasing segment (p < 0.001), and compared to the linearly increasing segment for CON (p < 0.001). The a terms for BFR were greater during the linearly decreasing than linearly increasing segment (p = 0.028). Steady force N-EMGRMS was greater for BFR than CON collapsed across sex (p = 0.041). CONCLUSION: BFR likely elicited additional recruitment of higher threshold motor units during the linearly increasing- and steady force-segment. The differences between activation and deactivation strategies were only observed with BFR, such as the b terms decreased and the a terms increased for the linearly decreasing segment in comparison to the increasing segment. However, EMGRMS-force relationships during the linearly increasing- and decreasing-segments were not different between sexes during BFR and CON.


Asunto(s)
Codo , Contracción Isométrica , Músculo Esquelético , Humanos , Masculino , Femenino , Músculo Esquelético/fisiología , Músculo Esquelético/irrigación sanguínea , Codo/fisiología , Adulto , Contracción Isométrica/fisiología , Flujo Sanguíneo Regional/fisiología , Electromiografía/métodos , Adulto Joven , Contracción Muscular/fisiología
14.
Eur J Appl Physiol ; 124(4): 1121-1129, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37889287

RESUMEN

PURPOSE: To determined sex differences in absolute- and %-reductions in blood flow during intermittent muscular contractions as well as relationships between blood flow reductions and time to task failure (TTF). METHODS: Thirteen males (25 ± 4 years) and 13 females (22 ± 5 years) completed intermittent isometric trapezoidal forearm flexion at 50% maximal voluntary contraction until task failure. Doppler ultrasound was used to measure brachial artery blood flow (BABF) during the 12-s plateau phase and 12-s relaxation phase. RESULTS: Target torque was less in females than males (24 ± 5 vs. 42 ± 7 Nm; p < 0.001); however, TTF was not different between sexes (F: 425 ± 187 vs. M: 401 ± 158 s; p = 0.72). Relaxation-phase BABF at end-exercise was less in females than males (435 ± 161 vs. 937 ± 281 mL/min; p < 0.001) but contraction-phase BABF was not different (127 ± 46 vs. 190 ± 99 mL/min; p = 0.42). Absolute- and %-reductions in BABF by contraction were less in females than males (309 ± 146 vs. 747 ± 210 mL/min and 69 ± 10 vs. 80% ± 6%, respectively; both p < 0.01) and were associated with target torque independent of sex (r = 0.78 and 0.56, respectively; both p < 0.01). Absolute BABF reduction per target torque (mL/min/Nm) and TTF were positively associated in males (r = 0.60; p = 0.031) but negatively associated in females (r = - 0.61; p = 0.029). CONCLUSIONS: This study provides evidence that females incur less proportional reduction in limb blood flow from muscular contraction than males at a matched relative intensity suggesting females may maintain higher levels of muscle oxygen delivery and metabolite removal than males across the contraction-relaxation cycle of intermittent exercise.


Asunto(s)
Fatiga Muscular , Músculo Esquelético , Humanos , Masculino , Femenino , Músculo Esquelético/fisiología , Fatiga Muscular/fisiología , Caracteres Sexuales , Contracción Isométrica/fisiología , Contracción Muscular/fisiología , Extremidad Superior , Torque
15.
Hum Vaccin Immunother ; 20(1): 2297453, 2024 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-38155525

RESUMEN

Cancer immunotherapy has emerged as a promising strategy to treat cancer patients. Among the wide range of immunological approaches, cancer vaccines have been investigated to activate and expand tumor-reactive T cells. However, most cancer vaccines have not shown significant clinical benefit as monotherapies. This is likely due to the antigen targets of vaccines, "self" proteins to which there is tolerance, as well as to the immunosuppressive tumor microenvironment. To help circumvent immune tolerance and generate effective immune responses, adjuvants for cancer vaccines are necessary. One representative adjuvant family is Toll-Like receptor (TLR) agonists, synthetic molecules that stimulate TLRs. TLRs are the largest family of pattern recognition receptors (PRRs) that serve as the sensors of pathogens or cellular damage. They recognize conserved foreign molecules from pathogens or internal molecules from cellular damage and propel innate immune responses. When used with vaccines, activation of TLRs signals an innate damage response that can facilitate the development of a strong adaptive immune response against the target antigen. The ability of TLR agonists to modulate innate immune responses has positioned them to serve as adjuvants for vaccines targeting infectious diseases and cancers. This review provides a summary of various TLRs, including their expression patterns, their functions in the immune system, as well as their ligands and synthetic molecules developed as TLR agonists. In addition, it presents a comprehensive overview of recent strategies employing different TLR agonists as adjuvants in cancer vaccine development, both in pre-clinical models and ongoing clinical trials.


Asunto(s)
Vacunas contra el Cáncer , Neoplasias , Humanos , Adyuvantes de Vacunas , Agonistas de los Receptores Toll-Like , Vacunas contra el Cáncer/uso terapéutico , Adyuvantes Inmunológicos , Antígenos , Neoplasias/tratamiento farmacológico , Microambiente Tumoral
16.
Astrobiology ; 23(12): 1348-1367, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-38079228

RESUMEN

Democratizing genomic data science, including bioinformatics, can diversify the STEM workforce and may, in turn, bring new perspectives into the space sciences. In this respect, the development of education and research programs that bridge genome science with "place" and world-views specific to a given region are valuable for Indigenous students and educators. Through a multi-institutional collaboration, we developed an ongoing education program and model that includes Illumina and Oxford Nanopore sequencing, free bioinformatic platforms, and teacher training workshops to address our research and education goals through a place-based science education lens. High school students and researchers cultivated, sequenced, assembled, and annotated the genomes of 13 bacteria from Mars analog sites with cultural relevance, 10 of which were novel species. Students, teachers, and community members assisted with the discovery of new, potentially chemolithotrophic bacteria relevant to astrobiology. This joint education-research program also led to the discovery of species from Mars analog sites capable of producing N-acyl homoserine lactones, which are quorum-sensing molecules used in bacterial communication. Whole genome sequencing was completed in high school classrooms, and connected students to funded space research, increased research output, and provided culturally relevant, place-based science education, with participants naming three novel species described here. Students at St. Andrew's School (Honolulu, Hawai'i) proposed the name Bradyrhizobium prioritasuperba for the type strain, BL16AT, of the new species (DSM 112479T = NCTC 14602T). The nonprofit organization Kauluakalana proposed the name Brenneria ulupoensis for the type strain, K61T, of the new species (DSM 116657T = LMG = 33184T), and Hawai'i Baptist Academy students proposed the name Paraflavitalea speifideiaquila for the type strain, BL16ET, of the new species (DSM 112478T = NCTC 14603T).


Asunto(s)
Exobiología , Instituciones Académicas , Humanos , Hawaii , Genómica , Bacterias
17.
J Strength Cond Res ; 37(12): 2467-2476, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-38015736

RESUMEN

ABSTRACT: Boffey, D, DiPrima, JA, Kendall, KL, Hill, EC, Stout, JR, and Fukuda, DH. Influence of body composition, load-velocity profiles, and sex-related differences on army combat fitness test performance. J Strength Cond Res 37(12): 2467-2476, 2023-The Army Combat Fitness Test (ACFT) became the U.S. Army's mandatory physical fitness test in April of 2022. The purpose of this study was to determine the relationship between ACFT performance and both body composition and velocity profiles and to determine sex differences for these variables. Data were collected at 2 timepoints 4 months apart, from male (n = 55) and female (n = 17) Army Reserve Officers' Training Corps (ROTC) cadets. Body composition was assessed with a bioelectrical impedance spectroscopy device, and cadets completed a hex bar deadlift load-velocity profile (LVP) and ACFT on separate days. Stepwise multiple regressions were used to explain the amount of variance in ACFT total score and individual event performance. Significance for statistical tests was defined as an alpha level of p ≤ 0.05. Muscle mass and body fat percentage accounted for 49% of shared variance of total ACFT score, and deadlift maximal power and maximal velocity accounted for 67% of shared variance of total ACFT score. The 3 repetition maximum deadlift, standing power throw, hand-release push-up, and sprint-drag-carry events favored cadets with more muscle mass, whereas the leg tuck was influenced by the body fat percentage and the 2-mile run was affected by fat mass. Sex had greater predictive capability for the 2-mile run than body composition. Men outperformed women on all individual events, with the greatest differences on standing power throw and sprint-drag-carry. It is recommended that Army ROTC cadets taking the ACFT maximize lower-body power production and increase muscle mass.


Asunto(s)
Prueba de Esfuerzo , Personal Militar , Humanos , Masculino , Femenino , Prueba de Esfuerzo/métodos , Caracteres Sexuales , Aptitud Física/fisiología , Ejercicio Físico , Composición Corporal
18.
Autism ; : 13623613231200679, 2023 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-37837362

RESUMEN

LAY ABSTRACT: Existing research has identified an increased risk of depression among autistic adults, which can negatively impact their adaptive functioning abilities and socioeconomic outcomes. Mobile app-based meditation is a feasible, accessible, and effective self-care solution for depression among neurotypical adults, but there is limited evidence for the long-term benefits of app-based meditation among autistic adults. Habits are a key behavioral strategy for maintaining behavior change, and anchoring is one effective habit formation intervention that has yet to be tested among autistic adults. This study demonstrates that it is both feasible and effective to integrate the anchoring habit formation strategy into an app-based meditation intervention for establishing meditation habits among autistic adults. In addition, the study shows that app-based meditation habits were successful at maintaining reductions in depressive symptoms over 6 months. These results demonstrate the power of anchoring-based habit formation interventions for establishing healthy habits among autistic adults, which offers a promising behavioral intervention technique for establishing other healthy habits among autistic adults. The study also shows that app-based meditation habits are an effective long-term self-care solution for managing depressive symptoms among autistic adults that should be used by mental health providers and policymakers. Future research should test this combined anchoring and app-based meditation intervention technique among larger samples of autistic adults and over longer durations to better understand the mechanisms underlying the success of this intervention.

19.
J Strength Cond Res ; 37(10): 2002-2007, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37729513

RESUMEN

ABSTRACT: Renziehausen, JM, Bergquist, AM, Park, J-H, Hill, EC, Wells, AJ, Stout, JR, and Fukuda, DH. Time of day effects on anaerobic performance using a nonmotorized treadmill. J Strength Cond Res 37(10): 2002-2007, 2023-The purpose of this study was to determine the effects of time of day on performance during a maximal effort sprinting assessment (30nmt) and determine potential differences based on chronotype and sex. Twenty-six recreationally active men (n = 12) and women (n = 14) between the ages of 18 and 35 years old (21.5 ± 2.4 years) completed the 30nmt at 9:00 am, 2:00 pm, and 7:00 pm in a randomized order over a 24-hour period. Resting heart rate and temperature assessments were taken at each visit. A dietary recall and the Morningness-Eveningness Questionnaire were used to assess kilocalories (kcals) and chronotype, respectively. Two-way (time x sex) repeated measures analyses of variance were conducted to determine differences in peak/mean power, peak/mean velocity, distance, resting heart rate, temperature, and kcals at each time point. Paired sample t tests were used to assess peak and nadir of each performance variable. A significance level was set at p < 0.05. There was a significant main effect for temperature (p < 0.001), resting heart rate (p = 0.007), and pre-exercise caloric intake (p = 0.021) throughout the day. No significant main effects for time were found for peak power (p = 0.766), mean power (p = 0.094), peak velocity (p = 0.497), mean velocity (p = 0.193), or distance (p = 0.262). There were no significant time × sex interactions for any dependent performance variables (p > 0.05). Significant differences were shown between the peak and nadir of each performance variable (p < 0.001). There were no significant differences in performance during maximal effort anaerobic assessments shown throughout the day; however, peak/nadir of performance times may be individualized and differ between morning types and intermediate types.


Asunto(s)
Cronotipo , Ingestión de Energía , Masculino , Humanos , Femenino , Adolescente , Adulto Joven , Adulto , Anaerobiosis , Recuerdo Mental , Temperatura
20.
Integr Org Biol ; 5(1): obad028, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37670952

RESUMEN

Studies of the Papuan region have provided fundamental insights into the evolutionary processes generating its exceptional biodiversity, but the influence of geological processes merits further study. Lying at the junction of five tectonic plates, this region has experienced a turbulent geological history that has not only produced towering mountains allowing elevational specialization and island archipelagos with varying degrees of isolation promoting vicariance, but also active margins where land masses have collided and been subsequently rifted apart creating a mosaic of intermixed terranes with vastly different geological histories. Asterophryine frogs are a hyperdiverse clade representing half the world's microhylid diversity (over 360 species) centered on New Guinea and its satellite islands. We show that vicariance facilitated by geological history explains this far and wide distribution of a clade that should have poor dispersal abilities. We recovered a mainland tectonic unit, the East Papua Composite Terrane (EPCT), as the center of origin for Asterophryinae and no fewer than 71 instances of what appear to be long-distance dispersal events, 29 of which are between mainland regions, with 42 from the mainland to the islands, some presently as far as 200 km away from source populations over open ocean. Furthermore, we find strong support for a "Slow and Steady" hypothesis for the formation of the northern margin of New Guinea by many separate accretion events during the Miocene, over other major geological alternatives, consistent with the 20 M year age of the clade and arrival via the EPCT. In addition, the historical biogeography of our frogs strongly supports an affiliation of the Louisiade Archipelago and Woodlark Island with the Owen Stanley Range on the EPCT, and the recent proximity of the large New Britain Island. Our results show that Asterophryinae did not have to repeatedly and independently disperse across large ocean barriers to the offshore islands, against the predictions of island biogeography theory, but that the current distribution can be explained through vicariance and short-distance oceanic dispersal as historical land connections disappeared and islands slowly became separated from each other. We show that islands have a life history, changing in distance from other land masses, with consequent opportunities for dispersal, isolation, and cladogenesis of their biotas. More broadly, we can begin to see how the geological history of the Papuan region can result in the rapid accumulation and staggering number of extant species.

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