RESUMO
In anoxia-sensitive mammals, hypoxia inducible factor (HIF) promotes cellular survival in hypoxia, but also tumorigenesis. By comparison, anoxia-tolerant vertebrates likely need to circumvent a prolonged upregulation of HIF to survive long-term anoxia, making them attractive biomedical models for investigating HIF regulation. To lend insight into the role of HIF in anoxic Trachemys scripta ventricle and telencephalon, 21 °C- and 5 °C-acclimated turtles were exposed to normoxia, anoxia (24 h at 21 °C; 24 h or 14 d at 5 °C) or anoxia + reoxygenation and the gene expression of HIF-1α (hif1a) and HIF-2α (hif2a), two regulators of HIF, and eleven putative downstream targets of HIF quantified by qPCR. Changes in gene expression with anoxia at 21 °C differentially aligned with a circumvention of HIF activity. Whereas hif1a and hif2a expression was unaffected in ventricle and telencephalon, and BCL2 interacting protein 3 gene expression reduced by 30% in telencephalon, gene expression of vascular endothelial growth factor-A increased in ventricle (4.5-fold) and telencephalon (1.5-fold), and hexokinase 1 (2-fold) and hexokinase 2 (3-fold) gene expression increased in ventricle. At 5 °C, the pattern of gene expression in ventricle or telencephalon was unaltered with oxygenation state. However, cold acclimation in normoxia induced downregulation of HIF-1α, HIF-2α, and HIF target gene expression in telencephalon. Overall, the findings lend support to the postulation that prolonged activation of HIF is counterproductive for long-term anoxia survival. Nevertheless, quantification of the effect of anoxia and acclimation temperature on HIF binding activity and regulation at the protein level are needed to provide a strong scientific framework whereby new strategies for oxygen related pathologies can be developed.
Assuntos
Tartarugas , Aclimatação , Animais , Expressão Gênica , Hipóxia/genética , Hipóxia/metabolismo , Mamíferos/metabolismo , Telencéfalo/metabolismo , Tartarugas/fisiologia , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
BACKGROUND/OBJECTIVE: The positive relationship between health benefits or the wellbeing of individuals and their engagement in physical activity is well-documented. Nevertheless, many Americans show no interest or perceive that "exercise is boring" as one of the reasons for not exercising. For these reasons, it is important to promote fun and enjoyment aspects of the activity to motivate people to participate in physical activity. The purpose of this study was to examine the physiological responses and the perception of enjoyment between the Trikke and the bicycle ergometer. METHODS: Thirty college students (15 males and 15 females) aged 18-45 years old voluntarily participated in the study and showed up on three occasions. The first session involved a 5-minute instructional video and practice on the Trikke. Participants were then randomized into sessions which involved either riding the Trikke or the bicycle ergometer. Participants of each group performed a 20-minute ride at 75-80% of maximal predicted heart rate. RESULTS: Results of mixed design analysis of variance (ANOVAs) indicated that VO2, energy expenditure, and rate of perceived exertion (RPE) of the participants were significantly (p < 0.001) higher when using the bicycle ergometer than the Trikke, and female participants were able to manipulate the Trikke more efficiently than their male counterparts. CONCLUSION: Participants were more efficient in using the Trikke than the bicycle ergometer. The Trikke may be an enjoyable alternative for those individuals, particularly women, who have lost interest in traditional forms of exercise.
RESUMO
This study examined postactivation potentiation (PAP) and its effect on performance during sprint swimming. After maximal muscular contraction, the muscles are in both a potentiated and fatigued state. However, fatigue dissipates faster than potentiation, creating a window of opportunity for possible performance enhancement. We observed 30 collegiate swimmers (15 men and 15 women) performing 2 swim trials in a randomized order. The control trial involved a standard swim warm-up, followed by a 6-minute rest and by a maximal 100-m freestyle swim effort. The PAP trial involved the same protocol; however, a PAP loading protocol involved the subjects completing 4 maximal 10-m swims at a 1-minute interval while attached to a resistive power rack and was completed before the 6-minute rest. Fifty-meter splits and blood lactates were also analyzed. There was a significant improvement in 100-m freestyle swim time (0.54 seconds) for the PAP trial vs. the control trial (p = 0.029). Both men and women improved during the PAP trial compared with the control trial, and there was no significant gender interaction. We conclude that PAP substantially enhances 100-m freestyle performance in collegiate swimmers and presents a valid technique for competitive performance enhancement.
Assuntos
Desempenho Atlético/fisiologia , Músculo Esquelético/fisiologia , Natação/fisiologia , Exercício de Aquecimento/fisiologia , Feminino , Humanos , Ácido Láctico/sangue , Masculino , Contração Muscular , Descanso , Fatores de Tempo , Adulto JovemRESUMO
Movement behavior is an important aspect of animal ecology but is challenging to study in species that are unobservable for some portion of their lives, such as those inhabiting subterranean environments. Using four years of robust-design capture-recapture data, we examined the probability of movement into subterranean habitat by a population of endangered Barton Springs salamanders (Eurycea sosorum), a species that inhabits both surface and subterranean groundwater habitats. We tested the effects of environmental variables and body size on survival and temporary emigration, using the latter as a measure of subterranean habitat use. Based on 2,046 observations of 1,578 individuals, we found that temporary emigration was higher for larger salamanders, 79% of which temporarily emigrated into subterranean habitat between primary sampling intervals, on average. Body size was a better predictor of temporary emigration and survival compared to environmental covariates, although coefficients from lower ranked models suggested turbidity and dissolved oxygen may influence salamander movement between the surface and subsurface. Surface population dynamics are partly driven by movement below ground and therefore surface abundance estimates represent a fraction of the superpopulation. As such, while surface habitat management remains an important conservation strategy for this species, periodic declines in apparent surface abundance do not necessarily indicate declines of the superpopulation associated with the spring habitat.
RESUMO
The purpose of this study was to observe the effectiveness of intermittent pneumatic compression (IPC) on reducing C-reactive protein (CRP) and DOMS after long distance running. Ten distance runners, five males and five females, ages 20-53 years performed two 20-mile runs at 70% VO2 max. Each run was followed by either no treatment (control) or IPC treatment for five consecutive days. For the IPC run, participants were treated for one hour immediately following the run and daily for five more days thereafter. On control runs, participants did not receive any treatment. Serum CRP was measured pre- and post-run, and daily thereafter for five days for both trials. Results indicated no significant difference (p > 0.05) between control and treatment runs in CRP levels. Subjective pain ratings indicated no significant difference in pain between control and treatment runs. In conclusion, there appear to be no substantial benefits of IPC in promoting recovery.
RESUMO
OBJECTIVE: This randomized controlled pilot study examined the feasibility and efficacy of a SystemCHANGE™ (SC) weight management intervention in adults with either multiple sclerosis or stroke. METHODS: Participants (n = 61) were randomized into two interventions: SC, which taught skills to modify personal environments, or active-control (AC), which taught health behavior guidelines. Sessions were held weekly for 12 weeks. Feasibility measures included recruitment and attrition rates. The primary outcome of body weight and secondary outcomes of emotional well-being and healthy behaviors were measured before and after the interventions. RESULTS: Average recruitment rate was 3.6 participants per month. Attrition rate was 14.8%. On average, 9.1 sessions were completed for SC and 10.7 for AC. Differences in weight loss were non-significant between interventions (P = 0.182), but significantly declined across both interventions (P = 0.011). Physical activity (P = 0.002), depression (P < 0.001), anxiety (P = 0.023), and self-efficacy (P = 0.022) all significantly improved for SC compared to AC. CONCLUSIONS: SC was feasible to implement and efficacious in improving secondary outcomes of emotional well-being and healthy behaviors, but was not efficacious in improving the primary outcome of weight loss. More research is needed to optimize SC. PRACTICE IMPLICATIONS: SC might be an alternative approach to cognitive-behavioral therapy for promoting emotional well-being and healthy behaviors.
Assuntos
Terapia Cognitivo-Comportamental , Exercício Físico , Adulto , Ansiedade , Peso Corporal , Humanos , Projetos PilotoRESUMO
We describe the use of telehealth technology in the rehabilitation of a college student with bronchopulmonary dysplasia. The present telerehabilitation application was necessitated by the absence of a formal university-based pulmonary rehabilitation program at Texas State University-San Marcos. Patient referral, evaluation, and rehabilitation were accomplished via interdisciplinary efforts of 3 separate university entities. Initial referral was obtained from the student health center, with pulmonary evaluation provided by the respiratory care department. Commercially available telerehabilitation equipment was then utilized to resolve exercise supervision and physiologic data-acquisition concerns. Forty-five individualized exercise sessions were administered by physical therapists via telerehabilitation distance voice and vision technology. Results reveal no substantive changes in pulmonary function test results, but there was improvement in functional aerobic capacity. Given the reduced life expectancy associated with bronchopulmonary dysplasia, investigators were afforded a unique opportunity to study an adult patient with this condition. Further, it appears the combined application of telerehabilitation technology and interdisciplinary cooperation among university departments is efficacious in the identification, evaluation, and rehabilitation of students with selected pulmonary disorders.
Assuntos
Displasia Broncopulmonar/reabilitação , Terapia por Exercício/métodos , Telemedicina , Adolescente , Displasia Broncopulmonar/fisiopatologia , Terapia por Exercício/instrumentação , Humanos , Recém-Nascido , Masculino , Equipe de Assistência ao Paciente , Testes de Função Respiratória , SobreviventesRESUMO
The authors tested the hypothesis that there is a correlation between hemispheric cognitive style and ear temperature. A sample of 100 participants completed a measure of hemispheric cognitive style, the Hemispheric Consensus Prediction Profile. Ear temperatures were taken in 2 sessions, 2 times for each ear at each session. Average left ear temperature was subtracted from average right ear temperature as an index of dominant temperature. Only 56 of the participants showed a stable dominant ear temperature. For these 56 participants, there was a statistically significant positive correlation between scores on the Hemispheric Consensus Prediction Profile and tympanic member temperature (Spearman's ρ =.29, 95% CI [.04,.51]). Individuals with a left hemispheric cognitive style tended to have a warmer left tympanic membrane temperature while those with a right hemispheric cognitive style tended to have a warmer right tympanic membrane temperature. Tympanic membrane temperatures are easily obtained using inexpensive and noninvasive technology. The relationship suggested by these findings may open new opportunities for the study of cerebral asymmetry.
Assuntos
Temperatura Corporal/fisiologia , Cérebro/fisiologia , Cognição/fisiologia , Membrana Timpânica/fisiologia , Adulto , Feminino , Humanos , Masculino , Termometria/economia , Termometria/métodos , Adulto JovemRESUMO
Traditional computer videogames are sedentary, whereas new computer videogames, such as the Nintendo(®) (Redmond, WA) "Wii™ Sports" games, allow users to physically interact while playing the sport. Energy expenditure (EE), heart rate (HR), and rating of perceived exertion (RPE) during heavy bag boxing versus the Nintendo "Wii Boxing" game were compared. Fifteen males and 14 females (mean age, 25.6 years; height, 171.3 cm; weight, 71.8 kg) randomly selected (by a coin toss) heavy bag boxing or "Wii Boxing" for their first test session and completed the other protocol at their second session at least 2 days later. Each session lasted for a total duration of 30 minutes and consisted of 10 3-minute exercise bouts with measurements of HR, RPE, and EE obtained from indirect calorimetry. A paired-samples t test was used to analyze the results. Significant differences were found for HR (bag, 156 beats per minute; Wii, 138 beats per minute; P=0.001) and RPE (bag, 13.8; Wii, 11.4; P=0.0001) but not for EE (bag, 8.0 kcal/minute; Wii, 7.1 kcal/minute; bag, 241 total kcal; Wii, 213 total kcal; P=0.078). The results suggest that computer active videogames, such as the Nintendo Wii, have the potential to provide similar EE as their traditional forms of exercise and may be a sufficient replacement for traditional target HR zone activities, especially in less fit individuals. Further research is needed to compare EE for different "Wii Sports" games with those for their traditional forms of exercise.