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1.
Eur J Appl Physiol ; 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38578446

RESUMO

PURPOSE: Walking net V ˙ O2 tends to increase with advancing age; however, factors contributing to this relationship have not been widely described. The implications of such findings could inform targeted strategies to promote independent mobility in older adults. Herein, we evaluated the relationship between net V ˙ O2 and age at two submaximal workloads while exploring potential moderators of this relationship. METHODS: Secondary analyses were performed on 35 older (65 ± 3 years) women who completed a battery of physical assessments including fixed-speed, non-graded and graded (+ 2.5%) treadmill walking with indirect calorimetry to determine net V ˙ O2. Maximal oxygen uptake ( V ˙ O2max), knee extensor maximal isometric voluntary contraction (MVC), peak rate of torque development (RTD), and plantar flexor range-of-motion (PFROM) were also measured. RESULTS: Bivariate correlations showed non-graded (r = 0.403, p = 0.017) and graded (r = 0.413, p = 0.014) net V ˙ O2 were positively related to age. Notably, these relationships strengthened after adjusting for V ˙ O2max. Regression modeling showed age, RTD:MVC ratio (composite of muscle performance), and PFROM together explained 49% and 34% of the variance in non-graded and graded net V ˙ O2, respectively. Further analyses suggested knee extensor MVC moderates the relationship between non-graded net V ˙ O2 and age, accounting for 9% of the variance [ΔR2 = 0.090, F (1,31) = 4.13, p = 0.05]. CONCLUSION: These data support the premise that, in older women, walking net V ˙ O2 rises with advancing age, and additionally, the RTD:MVC ratio and PFROM are independent correlates of non-graded net V ˙ O2. Exercise interventions with a high degree of training specificity including explosive, velocity-based elements may promote independent mobility in older women.

2.
J Hum Kinet ; 87: 11-21, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37229413

RESUMO

Our cross-sectional study aimed to investigate joint specificity of concentric muscle torque enhancement after a maximum eccentric contraction for the knee versus ankle joints across two different movement velocities (120°/s and 180°/s). After a familiarization session, 22 healthy young adults randomly performed concentric (CONC) and maximum eccentric preloaded concentric (EccCONC) muscle strength tests of the knee extensors and ankle plantar flexors of the non-dominant leg on an isokinetic strength testing device. We calculated the ratio between EccCONC and CONC (EccCONC/CONC) for all the conditions as the marker of concentric muscle torque enhancement. Separate two-way (joints x velocity) within repeated measures ANOVAs were used to determine joint-specific torque differences at 120°/s and 180°/s. CONC and EccCONC were greater for the knee extensors versus ankle plantar flexors at 120°/s and 180°/s (32.86%-102%; p < 0.001 for both); however, EccCONC/CONC was greater for the ankle plantar flexors than knee extensors at 120°/s (52.4%; p < 0.001) and 180°/s (41.9%; p < 0.001). There was a trend of greater EccCONC/CONC for the knee extensors at 180°/s than 120°/s (6.6%; p = 0.07). Our results show that greater concentric muscle torque enhancement after a maximal eccentric contraction occurs for the ankle plantar flexors versus knee extensors. Whether the joint- specificity of concentric muscle torque enhancement after a maximal eccentric contraction differentially affects sports performance is unknown. Our data provide a reference framework to investigate joint-specific concentric muscle torque enhancement for general and clinical athletic populations.

3.
Obesity (Silver Spring) ; 31 Suppl 1: 96-107, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36518092

RESUMO

OBJECTIVE: Data are mixed on whether intermittent fasting improves weight loss and cardiometabolic health. Here, the effects of time-restricted eating (TRE) in participants who consistently adhered ≥5 d/wk every week were analyzed. METHODS: Ninety patients aged 25 to 75 years old with obesity were randomized to early TRE (eTRE; 8-hour eating window from 07:00 to 15:00) or a control schedule (≥12-hour window) for 14 weeks. A per-protocol analysis of weight loss, body composition, cardiometabolic health, and other end points was performed. RESULTS: Participants who adhered to eTRE ≥5 d/wk every week had greater improvements in body weight (-3.7 ± 1.2 kg; p = 0.003), body fat (-2.8 ± 1.3 kg; p = 0.04), heart rate (-7 ± 3 beats/min; p = 0.02), insulin resistance (-2.80 ± 1.36; p = 0.047), and glucose (-9 ± 5 mg/dL; p = 0.047) relative to adherers in the control group. They also experienced greater improvements in mood, including fatigue and anger; however, they self-reported sleeping less and taking longer to fall asleep. CONCLUSIONS: For those who can consistently adhere at least 5 d/wk, eTRE is a valuable approach for improving body weight, body fat, cardiometabolic health, and mood. Further research is needed to determine whether eTRE's effects of shortening sleep but reducing fatigue are healthful or not.


Assuntos
Doenças Cardiovasculares , Obesidade , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Obesidade/metabolismo , Composição Corporal , Redução de Peso , Sono , Jejum , Ingestão de Alimentos
4.
Obesity (Silver Spring) ; 31 Suppl 1: 127-138, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36575143

RESUMO

OBJECTIVE: Time-restricted eating (TRE) can reduce body weight, but it is unclear how it influences dietary patterns and behavior. Therefore, this study assessed the effects of TRE on diet quality, appetite, and several eating behaviors. METHODS: Adults with obesity were randomized to early TRE plus energy restriction (eTRE + ER; 8-hour eating window from 7:00 a.m. to 3:00 p.m.) or a control eating schedule plus energy restriction (CON + ER; ≥12-hour window) for 14 weeks. Food intake was assessed via the Remote Food Photography Method, while eating patterns, appetite, and eating behaviors were assessed via questionnaires. RESULTS: A total of 59 participants completed the trial, of whom 45 had valid food records. eTRE + ER did not affect eating frequency, eating restraint, emotional eating, or the consistency of mealtimes relative to CON + ER. eTRE + ER also did not affect overall diet quality. The intensity and frequency of hunger and fullness were similar between groups, although the eTRE + ER group was hungrier while fasting. CONCLUSIONS: When combined with a weight-loss program, eTRE does not affect diet quality, meal frequency, eating restraint, emotional eating, or other eating behaviors relative to eating over more than a 12-hour window. Rather, participants implement eTRE as a simple timing rule by condensing their normal eating patterns into a smaller eating window.


Assuntos
Apetite , Ingestão de Energia , Adulto , Humanos , Comportamento Alimentar/psicologia , Dieta , Refeições , Ingestão de Alimentos
5.
Aging Clin Exp Res ; 34(10): 2541-2545, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35932401

RESUMO

Aging is accompanied by a low-grade proinflammatory status that plays a role in age-related vascular alterations. Syndecan-4 (SDC4) is a key component of the endothelial glycocalyx, and its extracellular domain can be shed by matrix metalloproteinase-9 (MMP-9). In vitro studies demonstrated that MMP-9-mediated shedding of SDC4 is induced by tumor necrosis factor-α (TNF- α) in human endothelial cells. However, the relationship between circulating shed SDC4, systemic inflammation, and age-related vascular alterations remains unknown. Here, we used linear regression models to examine the associations of serum SDC4 levels with cardiovascular hemodynamic phenotypes, serum MMP-9, and serum TNF-α and inteleukin-6 in healthy older women (n = 74). Serum SDC4 was not associated with proinflammatory cytokines or arterial elasticity. Nevertheless, we found significant correlations of SDC4 with MMP-9, heart rate, left ventricular ejection time, systemic vascular resistance, and blood pressure. Our preliminary evidence suggests that systemic inflammation might not induce SDC4 shedding in healthy aging.


Assuntos
Fenômenos Fisiológicos Cardiovasculares , Sindecana-4 , Idoso , Feminino , Humanos , Pressão Sanguínea , Células Endoteliais , Inflamação , Metaloproteinase 9 da Matriz/sangue , Sindecana-4/sangue , Fator de Necrose Tumoral alfa/sangue , Frequência Cardíaca , Função Ventricular Esquerda
6.
JAMA Intern Med ; 182(9): 953-962, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35939311

RESUMO

Importance: It is unclear how effective intermittent fasting is for losing weight and body fat, and the effects may depend on the timing of the eating window. This randomized trial compared time-restricted eating (TRE) with eating over a period of 12 or more hours while matching weight-loss counseling across groups. Objective: To determine whether practicing TRE by eating early in the day (eTRE) is more effective for weight loss, fat loss, and cardiometabolic health than eating over a period of 12 or more hours. Design, Setting, and Participants: The study was a 14-week, parallel-arm, randomized clinical trial conducted between August 2018 and April 2020. Participants were adults aged 25 to 75 years with obesity and who received weight-loss treatment through the Weight Loss Medicine Clinic at the University of Alabama at Birmingham Hospital. Interventions: All participants received weight-loss treatment (energy restriction [ER]) and were randomized to eTRE plus ER (8-hour eating window from 7:00 to 15:00) or control eating (CON) plus ER (≥12-hour window). Main Outcomes and Measures: The co-primary outcomes were weight loss and fat loss. Secondary outcomes included blood pressure, heart rate, glucose levels, insulin levels, and plasma lipid levels. Results: Ninety participants were enrolled (mean [SD] body mass index, 39.6 [6.7]; age, 43 [11] years; 72 [80%] female). The eTRE+ER group adhered 6.0 (0.8) days per week. The eTRE+ER intervention was more effective for losing weight (-2.3 kg; 95% CI, -3.7 to -0.9 kg; P = .002) but did not affect body fat (-1.4 kg; 95% CI, -2.9 to 0.2 kg; P = .09) or the ratio of fat loss to weight loss (-4.2%; 95% CI, -14.9 to 6.5%; P = .43). The effects of eTRE+ER were equivalent to reducing calorie intake by an additional 214 kcal/d. The eTRE+ER intervention also improved diastolic blood pressure (-4 mm Hg; 95% CI, -8 to 0 mm Hg; P = .04) and mood disturbances, including fatigue-inertia, vigor-activity, and depression-dejection. All other cardiometabolic risk factors, food intake, physical activity, and sleep outcomes were similar between groups. In a secondary analysis of 59 completers, eTRE+ER was also more effective for losing body fat and trunk fat than CON+ER. Conclusions and Relevance: In this randomized clinical trial, eTRE was more effective for losing weight and improving diastolic blood pressure and mood than eating over a window of 12 or more hours at 14 weeks. Trial Registration: ClinicalTrials.gov Identifier: NCT03459703.


Assuntos
Doenças Cardiovasculares , Redução de Peso , Tecido Adiposo , Adulto , Doenças Cardiovasculares/prevenção & controle , Jejum , Feminino , Humanos , Masculino , Obesidade/terapia , Redução de Peso/fisiologia
7.
J Acoust Soc Am ; 150(3): 2030, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34598640

RESUMO

Both the scarcity and environmental impact of disposable face masks, as in the COVID-19 pandemic, have instigated the recent development of reusable masks. Such face masks reduce transmission of infectious agents and particulates, but often impact a user's ability to be understood when materials, such as silicone or hard polymers, are used. In this work, we present a numerical optimisation approach to optimise waveguide topology, where a waveguide is used to transmit and direct sound from the interior of the mask volume to the outside air. This approach allows acoustic energy to be maximised according to specific frequency bands, including those most relevant to human speech. We employ this method to convert a resuscitator mask, made of silicone, into respiration personal protective equipment (PPE) that maximises the speech intelligibility index (SII). We validate this approach experimentally as well, showing improved SII when using the fabricated device. Together, this design represents a unique and effective approach to utilize and adapt available apparatus to filter air while improving the ability to communicate effectively, including in healthcare settings.


Assuntos
COVID-19 , Inteligibilidade da Fala , Humanos , Máscaras , Pandemias , Respiração , SARS-CoV-2
8.
Biomolecules ; 11(3)2021 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-33668381

RESUMO

Syndecans (SDCs) are transmembrane proteins that are present on most cell types where they play a role in multiple physiological processes, including cell-matrix adhesion and inflammation. Growing evidence suggests that elevated levels of both shed SDC1 and SDC4 are associated with hypertension and cardiovascular diseases, but their relationships with cardiovascular risk factors in healthy individuals are unknown. The primary objective of this study was to investigate whether serum levels of SDC4 and SDC1 were associated with body composition, hemodynamic parameters, pro-inflammatory cytokine concentrations, and urinary noradrenaline and dopamine levels in healthy women (17 African American and 20 European American) between the ages of 20 and 40 years old. Univariate analyses revealed only a significant (p < 0.05) inverse correlation between serum SDC1 and body fat percentage. On the other hand, serum SDC4 was positively correlated with systolic blood pressure, diastolic blood pressure, and urinary levels of noradrenaline and dopamine. Serum SDC4 was also a significant predictor of systolic blood pressure in a multivariate regression model that included fat-free mass and urinary dopamine levels as significant independent variables. The result did not change even adjusting for race. Our findings indicate that SDC4 has an important role in the physiological regulation of blood pressure.


Assuntos
Proteoglicanas de Heparan Sulfato/sangue , Hipertensão/sangue , Adulto , Composição Corporal/fisiologia , Catecolaminas/sangue , Dopamina/sangue , Feminino , Humanos , Norepinefrina/sangue , Pré-Menopausa , Sindecana-4/sangue , Adulto Jovem
9.
PLoS One ; 15(6): e0235119, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32574179

RESUMO

BACKGROUND: Colombia has officially adopted the parasite density levels of severe malaria established by the WHO (>50,000 parasites/µl). These values have been inferred from areas of high transmission in Africa and are not consistent with the dynamics of low and unstable transmission in Colombia. The objective of this study was therefore to determine the parasite density values observed in patients with severe malaria and their distribution in the different ecoepidemiological regions of Colombia. METHODS: A retrospective and descriptive study of confirmed cases of severe malaria was conducted in endemic areas of malaria in Colombia over the period 2014-2017. Data were collected from secondary sources of the Subnational Programs of Malaria Prevention and Control. Person, place, and time variables were selected. The official definition of severe malaria was adopted, and compliance with these criteria was determined. Univariate and bivariate analyses were conducted with absolute and relative frequency measures, and the relevant statistical tests were applied. RESULTS: The overall parasite density values in Colombia showed a geometric mean of 5,919 parasites/µl (95% CI: 5,608-6,248). By parasite species, the values were 6,151 (95% CI: 5,631-6,718) for Plasmodium falciparum and 5,815 (95% CI: 5,428-6,230) for Plasmodium vivax. The highest parasite density values were recorded in the Amazon ecoepidemiological region (8,177; 95% CI: 6,015-11,116), and the lowest values were recorded in the Andean region (5,026; 95% CI: 2,409-10,480). CONCLUSIONS: In endemic areas of low and unstable malaria transmission in the Colombian territory, the parasite density levels observed in populations with severe malaria are lower than the officially established values. The parasite density criterion is not really a relevant criterion for the definition of severe cases in Colombia and it certainly not be used to make a clinical decision about the severity of the disease.


Assuntos
Malária Falciparum/epidemiologia , Malária Vivax/epidemiologia , Plasmodium falciparum/crescimento & desenvolvimento , Plasmodium vivax/crescimento & desenvolvimento , Densidade Demográfica , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Colômbia/epidemiologia , Doenças Endêmicas/prevenção & controle , Feminino , Geografia , Humanos , Lactente , Malária Falciparum/parasitologia , Malária Falciparum/transmissão , Malária Vivax/parasitologia , Malária Vivax/transmissão , Masculino , Pessoa de Meia-Idade , Plasmodium falciparum/fisiologia , Plasmodium vivax/fisiologia , Prevalência , Estudos Retrospectivos , Índice de Gravidade de Doença , Adulto Jovem
10.
Front Physiol ; 10: 1472, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31849716

RESUMO

PURPOSE: Secondary analyses were performed to test whether combined aerobic and resistance training altered walking economy (i.e., net oxygen uptake) and/or stretch-shortening cycle potentiation (SSCP). A further objective was to determine if walking economy and SSCP were related before or after training. METHODS: Ninety-two postmenopausal women were enrolled wherein 76 completed 16 weeks of supervised aerobic and resistance training. Participants were randomized to one of three training groups based on frequencies: (a) 1 d⋅wk-1 (n = 23); (b) 2 d⋅wk-1 (n = 30) or; (c) 3 d⋅wk-1 (n = 23). Following assessments were performed at baseline and post-training. Indirect calorimetry was used to measure maximal oxygen uptake () and walking economy (submaximal - resting = net ) during a graded exercise test and steady-state treadmill task, respectively. SSCP was determined by measuring the difference between a concentric (CO) and counter-movement (CM) leg press throw. RESULTS: , walking economy, CO and CM velocity were significantly improved (p < 0.05) for all training groups, however; no time by group interactions were observed. Paired t-tests revealed participants exercise training 2 d⋅wk-1 exhibited a significant time effect for SSCP (+0.04 ± 0.09 ms-1; p = 0.03). At baseline, multiple linear regression showed a negative relationship between walking net and SSCP (r = -0.22; p < 0.04) adjusted for relative proportion of . No such relationship was found post-training. CONCLUSION: Among older postmenopausal women, our results indicate that irrespective of frequency of training, 16 weeks of combined aerobic and resistance exercise training increased ease of walking and economy. Additionally, only participants exercising 2 d⋅wk-1 exhibited significant improvement in SSCP.

11.
J Obes ; 2019: 8031705, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30956817

RESUMO

Sarcopenia not only affects the ability to lead an active lifestyle but also contributes to increased obesity, reduced quality of life, osteoporosis, and metabolic health, in part due to reduced locomotion economy and ease. On the other hand, increased obesity, decreased quality of life, and reduced metabolic health also contribute to sarcopenia. The purpose of this mini-review is to discuss the implications sarcopenia has for the development of obesity and comorbidities that occur with aging.


Assuntos
Inflamação/fisiopatologia , Obesidade/fisiopatologia , Sarcopenia/fisiopatologia , Envelhecimento/fisiologia , Composição Corporal , Comorbidade , Humanos , Inflamação/complicações , Inflamação/psicologia , Obesidade/complicações , Obesidade/psicologia , Qualidade de Vida , Sarcopenia/complicações , Sarcopenia/psicologia
12.
Eur J Clin Nutr ; 73(7): 1063-1068, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30250134

RESUMO

BACKGROUND/OBJECTIVES: To test the effects of weight loss with and without exercise training (aerobic or resistance) on intra-abdominal adipose tissue (IAAT) and risk factors for cardiovascular disease (CVD). Additionally, CVD risk factors was evaluated before and after weight loss using previously established IAAT cut-points. SUBJECTS/METHODS: One hundred twenty-two overweight premenopausal women were randomly assigned to one of three groups: (1) diet only (Diet); (2) diet and aerobic training (Diet + AT); or (3) diet and resistance training (Diet + RT); until a BMI of < 25 kg/m2 was reached. Computerized tomography was used to measure IAAT and blood lipids were measured by assay. Evaluations were made before and after weight loss. RESULTS: Though no group-by-time effects were found after weight loss, we observed significant time effects for: IAAT (-38.0%, P < 0.001), total cholesterol (TC) (-2.2%, P = 0.008), low-density lipoprotein cholesterol (LDL-C) (-4.8%, P < 0.001), high-density lipoprotein cholesterol (HDL-C) (+20.2%, P < 0.001), triglycerides (-18.7%, P < 0.001), TC/HDL-C (-16.3%, P < 0.001), and LDL-C/HDL-C (-18.0%, P < 0.001). Following weight loss, 40.2% of all participants reduced IAAT to < 40 cm2 (IAAT associated with low CVD risk). Furthermore, only 2.5% of participants had an IAAT > 110 cm2 (IAAT associated with high CVD risk) after weight loss. We also observed that decreases of IAAT were associated with decreased CVD risk factors after weight loss independent of race, changes in %fat mass and changes in maximal oxygen uptake. CONCLUSIONS: Caloric restriction leading to significant weight loss with or without exercise training appears to be equally effective for reducing IAAT and CVD risk factors.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Dieta Redutora , Exercício Físico , Absorciometria de Fóton , Adulto , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/complicações , Feminino , Humanos , Gordura Intra-Abdominal/diagnóstico por imagem , Lipídeos/sangue , Sobrepeso/complicações , Fatores de Risco , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Adulto Jovem
13.
PeerJ ; 6: e5700, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30324014

RESUMO

About nine years ago (circa 2009), Indo-Pacific lionfishes (Pterois volitans and P. miles) invaded the south Florida coral reef ecosystem. During the intervening period of time, there has been substantial research on their biology, life history, demography, and habitat preferences; however, little is known concerning their regional population status and trends in the region. Here, we use a large-scale fisheries independent reef fish visual survey to investigate lionfish population status among three south Florida regions: Dry Tortugas, Florida Keys, and southeast Florida. Density estimates (ind ha-1) have been relatively stable since 2012, and are lower than other areas reported in the western Atlantic and Caribbean Sea. Low, stable population densities in south Florida suggest there may be a natural mechanism for lionfish population control. In the Dry Tortugas, lionfish density in 2016 was significantly lower (0.6 ind ha-1 ± 0.15 SE) than the two other south Florida regions. The Dry Tortugas region has the highest percentage of marine protected areas, the lowest level of exploitation, and thus the highest densities of potential lionfish predators and competitors. In the Florida Keys and southeast Florida in 2016, lionfish densities were greater (5.4 ind ha-1 ± 1.0 SE and 9.0 ± 2.7 SE, respectively) than the Dry Tortugas. Fishing pressure on lionfish was higher in these two regions, but densities of several potential predators and competitors were substantially lower. Despite relatively low regional lionfish densities that can be attributed to some combination of fishing mortality and natural biocontrol, lionfish are still well established in the south Florida coral reef ecosystem, warranting continued concern.

14.
J Strength Cond Res ; 32(11): 3004-3010, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30239453

RESUMO

Hunter, GR, Fisher, G, Bryan, DR, Borges, JH, and Carter, SJ. Divergent blood pressure response after high-intensity interval exercise: a signal of delayed recovery? J Strength Cond Res 32(11): 3004-3010, 2018-The objective of this commentary is to highlight potential factors influential to the adaptation of high-intensity exercise. Herein, we present a rationale supporting the contention that elevated systolic blood pressure, after a bout of high-intensity exercise, may be indicative of delayed/incomplete recovery. Relative to type I skeletal muscle fibers, the unique cellular/vascular characteristics of type II muscle fibers may necessitate longer recovery periods, especially when exposed to repeated high-intensity efforts (i.e., intervals). In addition to the noted race disparities in cardiometabolic disease risk, including higher mean blood pressures, African Americans may have a larger percentage of type II muscle fibers, thus possibly contributing to noted differences in recovery after high-intensity exercise. Given that optimal recovery is needed to maximize physiological adaptation, high-intensity training programs should be individually-tailored and consistent with recovery profile(s). In most instances, even among those susceptible, the risk to nonfunctional overreaching can be largely mitigated if sufficient recovery is integrated into training paradigms.


Assuntos
Adaptação Fisiológica , Pressão Sanguínea , Exercício Físico/fisiologia , Treinamento Intervalado de Alta Intensidade , Negro ou Afro-Americano , Humanos , Masculino , Músculo Esquelético/fisiologia
15.
Neural Regen Res ; 13(7): 1253-1262, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30028335

RESUMO

While the peripheral nervous system has regenerative ability, restoration of sufficient function remains a challenge. Vimentin has been shown to be localized in axonal growth fronts and associated with nerve regeneration, including myelination, neuroplasticity, kinase signaling in nerve axoplasm, and cell migration; however, the mechanisms regulating its expression within Schwann cell (SC) remain unexplored. The aim of this study was to profile the spatial and temporal expression profile of microRNA (miRNA) in a regenerating rat sciatic nerve after transection, and explore the potential role of miR-138-5p targeting vimentin in SC proliferation and migration. A rat sciatic nerve transection model, utilizing a polyethylene nerve guide, was used to investigate miRNA expression at 7, 14, 30, 60, and 90 days during nerve regeneration. Relative levels of miRNA expression were determined using microarray analysis and subsequently validated with quantitative real-time polymerase chain reaction. In vitro assays were conducted with cultured Schwann cells transfected with miRNA mimics and assessed for migratory and proliferative potential. The top seven dysregulated miRNAs reported in this study have been implicated in cell migration elsewhere, and GO and KEGG analyses predicted activities essential to wound healing. Transfection of one of these, miRNA-138-5p, into SCs reduced cell migration and proliferation. miR-138-5p has been shown to directly target vimentin in cancer cells, and the luciferase assay performed here in rat Schwann cells confirmed it. These results detail a role of miR-138-5p in rat peripheral nerve regeneration and expand on reports of it as an important regulator in the peripheral nervous system.

16.
Obesity (Silver Spring) ; 26(8): 1255-1260, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29957829

RESUMO

OBJECTIVE: It is unclear whether there are race-specific differences in the maintenance of skeletal muscle during energy restriction. Changes in relative skeletal muscle index (RSMI; limb lean tissue divided by height squared) were compared following (1) diet alone, (2) diet + aerobic training, or (3) diet + resistance training. METHODS: Overweight, sedentary African American (AA; n = 72) and European American (EA; n = 68) women were provided an 800-kcal/d diet to reduce BMI < 25 kg/m2 . Regional fat-free mass was measured with dual-energy x-ray absorptiometry. Steady-state VO2 and heart rate responses during walking were measured. RESULTS: AA women had greater RSMI and preserved RSMI during diet alone, while RSMI was significantly reduced among EA women (EA women -3.6% vs. AA women + 1.1%; P < 0.05). Diet + resistance training subjects retained RSMI (EA women + 0.2% vs. AA women + 1.4%; P = 50.05), whereas diet + aerobic training subjects decreased RSMI (EA women -1.4% vs. AA women -1.5%; P < 0.05). Maintenance of RSMI was related to delta walking ease and economy. CONCLUSIONS: Compared with AA women, EA women are less muscular and lose more muscle during weight loss without resistance training. During diet-induced weight loss, resistance training preserves skeletal muscle, especially among premenopausal EA women. Maintenance of muscle during weight loss associates with better ease and economy of walking.


Assuntos
Dieta Redutora/efeitos adversos , Terapia por Exercício , Músculo Esquelético/patologia , Obesidade/dietoterapia , Obesidade/reabilitação , Sarcopenia , Redução de Peso/etnologia , Absorciometria de Fóton , Adulto , Negro ou Afro-Americano/estatística & dados numéricos , Peso Corporal/etnologia , Exercício Físico/fisiologia , Terapia por Exercício/métodos , Feminino , Humanos , Músculo Esquelético/metabolismo , Obesidade/etnologia , Obesidade/patologia , Tamanho do Órgão , Sobrepeso/dietoterapia , Sobrepeso/etnologia , Sobrepeso/patologia , Sobrepeso/reabilitação , Grupos Raciais/estatística & dados numéricos , Treinamento Resistido , Sarcopenia/etnologia , Sarcopenia/etiologia , Sarcopenia/prevenção & controle , Redução de Peso/fisiologia , População Branca/estatística & dados numéricos , Adulto Jovem
17.
Int J Exerc Sci ; 11(2): 42-54, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29795723

RESUMO

The functional implications of serum tumor necrosis factor-alpha (TNF-α), a marker of oxidative stress, on hemodynamic parameters at rest and during physical exertion are unclear. The aims of this investigation were to examine the independent associations of TNF-α on myocardial oxygen demand at rest and during submaximal exercise, while also evaluating the association of TNF-α on exercise tolerance. Forty, postmenopausal women, provided blood samples and completed a modified-Balke protocol to measure maximal oxygen uptake (VO2max). Large artery compliance was measured by pulse contour analyses while rate-pressure product (RPP), an index of myocardial oxygen demand, was measured at rest and during two submaximal workloads (i.e., ≈55% and ≈75% VO2max). RPP was calculated by dividing the product of heart rate and systolic blood pressure (via auscultation) by 100. Exercise tolerance corresponded with the cessation of the graded exercise test. During higher-intensity exertion, ≈75% VO2max, multiple linear regression revealed a positive association (r = 0.43; p = 0.015) between TNF-α and RPP while adjusting for maximal heart rate, VO2max, large artery compliance, and percent body fat. Path analyses revealed a significant indirect effect of large artery compliance on exercise tolerance through TNF-α, ß = 0.13, CI [0.03, 0.35], indicating greater levels of TNF-α associated with poorer exercise tolerance. These data suggest TNF-α independently associates with myocardial oxygen demand during physical exertion, thus highlighting the utility of higher-intensity efforts to expose important phenomena not apparent at rest. TNF-α also appears to be indirectly associated with the link between large artery compliance and exercise tolerance.

18.
Prim Care ; 44(3): 511-518, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28797376

RESUMO

This article describes how to perform advance care planning in the outpatient geriatric medicine setting. The article defines advance care planning and discusses components of advance care planning, such as advance directives, do-not-resuscitate orders, and Physician Orders for Life-Sustaining Treatment. The article describes how to document advance care planning discussions in the clinic and bill Medicare and ways for clinicians to improve their skill at leading these conversations.


Assuntos
Planejamento Antecipado de Cuidados , Assistência Ambulatorial , Serviços de Saúde para Idosos , Diretivas Antecipadas , Idoso , Humanos , Medicare , Ordens quanto à Conduta (Ética Médica) , Estados Unidos
19.
Artigo em Inglês | MEDLINE | ID: mdl-29546247

RESUMO

BACKGROUND: Obesity and weight gain after the diagnosis of prostate cancer are associated with an increased risk of prostate cancer recurrence and mortality; individualized plans to help prostate cancer survivors maintain or lose weight may be beneficial for recurrence risk reduction. Herein, we explore whether gains in cardiovascular fitness predict successful weight loss in men participating in a weight loss trial (NCT01886677). METHODS: Forty men were randomized to receive twice-weekly in-person and telephone-based guidance on calorie-restricted diets and aerobic exercise to promote ~0.91 kg/week weight loss, or wait-list control. Thirty-two men completed submaximal VO2 Treadmill Tests (TT), anthropometric measures and two 24-hour dietary recalls at baseline and follow-up. For this secondary analysis, study arms were combined and associations between baseline and longitudinal changes in physiological effort (PE, measured by heart rate during TT), predicted VO2max, caloric intake and weight loss were analyzed. RESULTS: Men lost 3.4 kg in 50 ± 23 days on the study. Multivariate linear regression indicated weight change was associated with change in PE at stage 2TT (Partial R = 0.635, p < 0.001), days on study (Partial R = -0.589, p = 0.002) and change in caloric intake (Partial R = 0.457, p = 0.019). CONCLUSIONS: Untrained men experiencing elevated heart rates during stage 2TT at baseline were able to achieve greater weight loss over the study period; this association was strengthened by a decrease in PE at the same level from baseline to follow-up concomitant with reduced caloric intake. Therefore, for these middle-aged and older men with lower aerobic fitness, exercise appears to be a key factor in achieving higher degrees of weight loss.

20.
J Gerontol A Biol Sci Med Sci ; 73(1): 73-80, 2017 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-28003374

RESUMO

BACKGROUND: We lack a comprehensive assessment of the risks and benefits of calorie restriction in older adults at high risk for cardiometabolic disease. Calorie restriction may reduce visceral adipose tissue (VAT) but also have negative effects on lean mass and quality of life. METHODS: We conducted a 52-week, randomized controlled trial involving 164 older adults with obesity taking at least one medication for hyperlipidemia, hypertension, or diabetes. Interventions included an exercise intervention alone (Exercise), or with diet modification and body weight maintenance (Maintenance), or with diet modification and energy restriction (Weight Loss). The primary outcome was change in VAT at 12 months. Secondary outcomes included cardiometabolic risk factors, functional status, and quality of life. RESULTS: A total of 148 participants had measured weight at 12 months. Despite loss of -1.6% ± 0.3% body fat and 4.1% ± 0.7% initial body weight, Weight Loss did not have statistically greater loss of VAT (-192.6 ± 185.2 cm3) or lean mass (-0.4 ± 0.3 kg) compared with Exercise (VAT = -21.9 ± 173.7 cm3; lean mass = 0.3 ± 0.3 kg). Quality of life improved in all groups with no differences between groups. No significant changes in physical function were observed. Weight Loss had significantly greater improvements in blood glucose (-8.3 ± 3.6 mg/dL, p < .05) and HDL-cholesterol (5.3 ± 1.9, p < .01) compared with Exercise. There were no group differences in the frequency of adverse events. CONCLUSIONS: While moderate calorie restriction did not significantly decrease VAT in older adults at high risk for cardiometabolic disease, it did reduce total body fat and cardiometabolic risk factors without significantly more adverse events and lean mass loss.


Assuntos
Restrição Calórica/métodos , Obesidade/dietoterapia , Qualidade de Vida , Redução de Peso/fisiologia , Idoso , Índice de Massa Corporal , Feminino , Seguimentos , Humanos , Masculino , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
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