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Journal of applied physiology 30건

  1. [해외논문]   Resistance training with instability is more effective than resistance training in improving spinal inhibitory mechanisms in Parkinson's disease   SCI SCIE

    Silva-Batista, Carla (<sup>1</sup>Laboratory of Adaptations to Strength Training, School of Physical Education and Sport, University of Séúáããão Paulo at Séúáãããão Paulo, Séúáããããão Paulo, Brazil) , Mattos, Eugenia Casella Tavares (<sup>1</sup>Laboratory of Adaptations to Strength Training, School of Physical Education and Sport, University of Séúáããão Paulo at Séúáãããão Paulo, Séúáããããão Paulo, Brazil) , Corcos, Daniel M. (<sup>2</sup>Department of Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, Illinois) , Wilson, Jessica M. (<sup>2</sup>Department of Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, Illinois) , Heckman, Charles J. (<sup>2</sup>Department of Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, Illinois;) , Kanegusuku, Hé , lcio , Piemonte, Maria Elisa Pimentel , Té , ú , lio de Mello, Marco , Forjaz, Clé , ú , á , udia , Roschel, Hamilton , Tricoli, Valmor , Ugrinowitsch, Carlos
    Journal of applied physiology v.122 no.1 ,pp. 1 - 10 , 2017 , 8750-7587 ,

    초록

    Patients with Parkinson’s disease (PD) have motor dysfunction. Spinal inhibitory mechanisms are important for modulating both supraspinal motor commands and sensory feedback at the spinal level. Resistance training with instability was more effective than resistance training in increasing the levels of presynaptic inhibition and disynaptic reciprocal inhibition of lower limb at rest of the patients with PD, reaching the average values of the healthy controls. This study assessed 1 ) the effects of 12 wk of resistance training (RT) and resistance training with instability (RTI) on presynaptic inhibition (PSI) and disynaptic reciprocal inhibition (DRI) of patients with Parkinson’s disease (PD); 2 ) the effectiveness of RT and RTI in moving PSI and DRI values of patients toward values of age-matched healthy controls (HC; Z-score analysis); and 3 ) associations between PSI and DRI changes and clinical outcomes changes previously published. Thirteen patients in RT group, 13 in RTI group, and 11 in a nonexercising control group completed the trial. While RT and RTI groups performed resistance exercises twice a week for 12 wk, only the RTI group used unstable devices. The soleus H reflex was used to evaluate resting PSI and DRI before and after the experimental protocol. The HC ( n = 31) was assessed at pretest only. There were significant group × time interactions for PSI ( P < 0.0001) and DRI ( P < 0.0001). RTI was more effective than RT in increasing the levels of PSI ( P = 0.0154) and DRI ( P < 0.0001) at posttraining and in moving PSI [confidence interval (CI) 0.1–0.5] and DRI (CI 0.6–1.1) levels to those observed in HC. There was association between DRI and quality of life changes ( r = −0.69, P = 0.008) and a strong trend toward association between PSI and postural instability changes ( r = 0.60, P = 0.051) after RTI. RTI increased PSI and DRI levels more than RT, reaching the average values of the HC. Thus RTI may cause plastic changes in PSI and DRI pathways that are associated with some PD clinical outcomes. NEW & NOTEWORTHY Patients with Parkinson’s disease (PD) have motor dysfunction. Spinal inhibitory mechanisms are important for modulating both supraspinal motor commands and sensory feedback at the spinal level. Resistance training with instability was more effective than resistance training in increasing the levels of presynaptic inhibition and disynaptic reciprocal inhibition of lower limb at rest of the patients with PD, reaching the average values of the healthy controls.

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  2. [해외논문]   Habitual aerobic exercise does not protect against micro- or macrovascular endothelial dysfunction in healthy estrogen-deficient postmenopausal women   SCI SCIE

    Santos-Parker, Jessica R. (<sup>1</sup>Integrative Physiology, University of Colorado Boulder, Boulder, Colorado) , Strahler, Talia R. (and ) , Vorwald, Victoria M. (<sup>1</sup>Integrative Physiology, University of Colorado Boulder, Boulder, Colorado) , Pierce, Gary L. (and ) , Seals, Douglas R. (<sup>1</sup>Integrative Physiology, University of Colorado Boulder, Boulder, Colorado)
    Journal of applied physiology v.122 no.1 ,pp. 11 - 19 , 2017 , 8750-7587 ,

    초록

    This is the first study to demonstrate that habitual aerobic exercise may not protect against age/menopause-related whole forearm microvascular endothelial dysfunction in healthy nonobese estrogen-deficient postmenopausal women, consistent with recent findings regarding macrovascular endothelial function. This is in contrast to what is observed in healthy middle-aged and older aerobic exercise-trained men. Aging causes micro- and macrovascular endothelial dysfunction, as assessed by endothelium-dependent dilation (EDD), which can be prevented and reversed by habitual aerobic exercise (AE) in men. However, in estrogen-deficient postmenopausal women, whole forearm microvascular EDD has not been studied, and a beneficial effect of AE on macrovascular EDD has not been consistently shown. We assessed forearm blood flow in response to brachial artery infusions of acetylcholine (FBF ACh ), a measure of whole forearm microvascular EDD, and brachial artery flow-mediated dilation (FMD), a measure of macrovascular EDD, in 12 premenopausal sedentary women (Pre-S; 24 ± 1 yr; V̇ O 2max = 37 37.5 ± 1.6 ml·kg −1 ·min −1 ), 25 estrogen-deficient postmenopausal sedentary women (Post-S; 62 ± 1 yr; V̇V̇ O 2max = 24 24.7 ± 0.9 ml·kg −1 ·min −1 ), and 16 estrogen-deficient postmenopausal AE-trained women (Post-AE; 59 ± 1 yr; V̇V̇V̇ O 2max = 40 40.4 ± 1.4 ml·kg −1 ·min −1 ). FBF ACh was lower in Post-S and Post-AE compared with Pre-S women (135 ± 9 and 116 ± 17 vs. 193 ± 21 AUC, respectively, both P < 0.008), whereas Post-S and Post-AE women were not different ( P = 0.3). Brachial artery FMD was 34% (5.73 ± 0.67%) and 45% (4.79 ± 0.57%) lower in Post-S and Post-AE, respectively, vs. Pre-S women (8.69 ± 0.95%, both P ≤ 0.01), but not different between Post-S and Post-AE women ( P = 0.3). Post-AE women had lower circulating C-reactive protein and oxidized low-density lipoprotein compared with Post-S women (0.5 ± 0.1 vs. 1.1 ± 0.2 mg/l and 40 ± 4 vs. 55 ± 3 U/l, respectively, both P = 0.01), but these markers were not correlated to FBF ACh ( P = 0.3) or brachial artery FMD ( P = 0.8). These findings are consistent with the idea that habitual AE does not protect against age/menopause-related whole forearm micro- and macrovascular endothelial dysfunction in healthy nonobese estrogen-deficient postmenopausal women, despite being associated with lower systemic markers of inflammation and oxidative stress. NEW & NOTEWORTHY This is the first study to demonstrate that habitual aerobic exercise may not protect against age/menopause-related whole forearm microvascular endothelial dysfunction in healthy nonobese estrogen-deficient postmenopausal women, consistent with recent findings regarding macrovascular endothelial function. This is in contrast to what is observed in healthy middle-aged and older aerobic exercise-trained men.

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    NDSL에서는 해당 원문을 복사서비스하고 있습니다. 아래의 원문복사신청 또는 장바구니담기를 통하여 원문복사서비스 이용이 가능합니다.

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  3. [해외논문]   Neuromuscular electrical stimulation prior to presleep protein feeding stimulates the use of protein-derived amino acids for overnight muscle protein synthesis   SCI SCIE

    Dirks, Marlou L. , Groen, Bart B. L. , Franssen, Rinske , van Kranenburg, Janneau , van Loon, Luc J. C.
    Journal of applied physiology v.122 no.1 ,pp. 20 - 27 , 2017 , 8750-7587 ,

    초록

    Neuromuscular electrical stimulation (NMES) as well as presleep dietary protein ingestion represent effective strategies to stimulate muscle protein synthesis rates. Here we demonstrate that in older men after a day of bed rest, the application of NMES prior to presleep protein feeding stimulates the use of dietary protein-derived amino acids for overnight muscle protein synthesis by 18% compared with presleep protein feeding only. Short periods of muscle disuse result in substantial skeletal muscle atrophy. Recently, we showed that both neuromuscular electrical stimulation (NMES) as well as presleep dietary protein ingestion represent effective strategies to stimulate muscle protein synthesis rates. In this study, we test our hypothesis that NMES can augment the use of presleep protein-derived amino acids for overnight muscle protein synthesis in older men. Twenty healthy, older [69 ± 1 (SE) yr] men were subjected to 24 h of bed rest, starting at 8:00 AM. In the evening, volunteers were subjected to 70-min 1-legged NMES, while the other leg served as nonstimulated control (CON). Immediately following NMES, 40 g of intrinsically L -[1- 13 C]-phenylalanine labeled protein was ingested prior to sleep. Blood samples were taken throughout the night, and muscle biopsies were obtained from both legs in the evening and the following morning (8 h after protein ingestion) to assess dietary protein-derived L -[1- 13 C]-phenylalanine enrichments in myofibrillar protein. Plasma phenylalanine concentrations and plasma L -[1- 13 C]-phenylalanine enrichments increased significantly following protein ingestion and remained elevated for up to 6 h after protein ingestion ( P < 0.05). During overnight sleep, myofibrillar protein-bound L -[1- 13 C]-phenylalanine enrichments (MPE) increased to a greater extent in the stimulated compared with the control leg (0.0344 ± 0.0019 vs. 0.0297 ± 0.0016 MPE, respectively; P < 0.01), representing 18 ± 6% greater incorporation of presleep protein-derived amino acids in the NMES compared with CON leg. In conclusion, application of NMES prior to presleep protein feeding stimulates the use of dietary protein-derived amino acids for overnight muscle protein synthesis in older men. NEW & NOTEWORTHY Neuromuscular electrical stimulation (NMES) as well as presleep dietary protein ingestion represent effective strategies to stimulate muscle protein synthesis rates. Here we demonstrate that in older men after a day of bed rest, the application of NMES prior to presleep protein feeding stimulates the use of dietary protein-derived amino acids for overnight muscle protein synthesis by 18% compared with presleep protein feeding only.

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  4. [해외논문]   Single passive leg movement-induced hyperemia: a simple vascular function assessment without a chronotropic response   SCI SCIE

    Venturelli, Massimo (<sup>1</sup>Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, Utah) , Layec, Gwenael (<sup>1</sup>Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, Utah) , Trinity, Joel (<sup>1</sup>Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, Utah) , Hart, Corey R. (<sup>4</sup>Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah ) , Broxterman, Ryan M. (<sup>4</sup>Department of Exercise and Sport Science, University of Utah, Salt Lake City, Utah ) , Richardson, Russell S. (<sup>1</sup>Department of Internal Medicine, Division of Geriatrics, University of Utah, Salt Lake City, Utah;)
    Journal of applied physiology v.122 no.1 ,pp. 28 - 37 , 2017 , 8750-7587 ,

    초록

    Using the single passive leg movement (PLM) technique, a variant of the vascular function assessment PLM, we have identified a novel peripheral vascular assessment method that is more easily performed than PLM, which, by not evoking potentially confounding central hemodynamic responses, may be more useful clinically. Passive leg movement (PLM)-induced hyperemia is a novel approach to assess vascular function, with a potential clinical role. However, in some instances, the varying chronotropic response induced by PLM has been proposed to be a potentially confounding factor. Therefore, we simplified and modified the PLM model to require just a single PLM (sPLM), an approach that may evoke a peripheral hemodynamic response, allowing a vascular function assessment, but at the same time minimizing central responses. To both characterize and assess the utility of sPLM, in 12 healthy subjects, we measured heart rate (HR), stroke volume, cardiac output (CO), mean arterial pressure (MAP), leg blood flow (LBF), and calculated leg vascular conductance (LVC) during both standard PLM, consisting of passive knee flexion and extension performed at 1 Hz for 60 s, and sPLM, consisting of only a single passive knee flexion and extension over 1 s. During PLM, MAP transiently decreased (5 ± 1 mmHg), whereas both HR and CO increased from baseline (6.0 ± 1.1 beats/min, and 0.8 ± 0.01 l/min, respectively). Following sPLM, MAP fell similarly (5 ± 2 mmHg; P = 0.8), but neither HR nor CO responses were identifiable. The peak LBF and LVC response was similar for PLM (993 ± 189 ml/min; 11.9 ± 1.5 ml·min −1 ·mmHg −1 , respectively) and sPLM (878 ± 119 ml/min; 10.9 ± 1.6 ml·min −1 ·mmHg −1 , respectively). Thus sPLM represents a variant of the PLM approach to assess vascular function that is more easily performed and evokes a peripheral stimulus that induces a significant hyperemia, but does not generate a potentially confounding, chronotropic response, which may make sPLM more useful clinically. NEW & NOTEWORTHY Using the single passive leg movement (PLM) technique, a variant of the vascular function assessment PLM, we have identified a novel peripheral vascular assessment method that is more easily performed than PLM, which, by not evoking potentially confounding central hemodynamic responses, may be more useful clinically.

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    회원님의 원문열람 권한에 따라 열람이 불가능 할 수 있으며 권한이 없는 경우 해당 사이트의 정책에 따라 회원가입 및 유료구매가 필요할 수 있습니다.이동하는 사이트에서의 모든 정보이용은 NDSL과 무관합니다.

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  5. [해외논문]   Obesity, type 2 diabetes, and impaired insulin-stimulated blood flow: role of skeletal muscle NO synthase and endothelin-1   SCI SCIE

    Reynolds, Leryn J. (<sup>1</sup>Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri) , Credeur, Daniel P. (<sup>2</sup>Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri) , Manrique, Camila (<sup>3</sup>Department of Medicine-Division of Endocrinology, University of Missouri, Columbia, Missouri) , Padilla, Jaume (<sup>1</sup>Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri) , Fadel, Paul J. (<sup>2</sup>Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri) , Thyfault, John P. (<sup>1</sup>Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri;)
    Journal of applied physiology v.122 no.1 ,pp. 38 - 47 , 2017 , 8750-7587 ,

    초록

    Although impairments in endothelial signaling are hypothesized to reduce insulin-stimulated blood flow in type 2 diabetes (T2D), human studies examining these links are limited. We provide the first measures of nitric oxide synthase and endothelin-1 expression from skeletal muscle tissue containing native microvessels in individuals with and without T2D before and during insulin stimulation. Higher basal skeletal muscle expression of endothelin-1 and reduced endothelial nitric oxide phosphorylation (peNOS)/eNOS may contribute to reduced insulin-stimulated blood flow in obese T2D patients. Increased endothelin-1 (ET-1) and reduced endothelial nitric oxide phosphorylation (peNOS) are hypothesized to reduce insulin-stimulated blood flow in type 2 diabetes (T2D), but studies examining these links in humans are limited. We sought to assess basal and insulin-stimulated endothelial signaling proteins (ET-1 and peNOS) in skeletal muscle from T2D patients. Ten obese T2D [glucose disposal rate (GDR): 6.6 ± 1.6 mg·kg lean body mass (LBM) −1 ·min −1 ] and 11 lean insulin-sensitive subjects (Lean GDR: 12.9 ± 1.2 mg·kg LBM −1 ·min −1 ) underwent a hyperinsulinemic-euglycemic clamp with vastus lateralis biopsies taken before and 60 min into the clamp. Basal biopsies were also taken in 11 medication-naive, obese, non-T2D subjects. ET-1, peNOS (Ser1177), and eNOS protein and mRNA were measured from skeletal muscle samples containing native microvessels. Femoral artery blood flow was assessed by duplex Doppler ultrasound. Insulin-stimulated blood flow was reduced in obese T2D (Lean: +50.7 ± 6.5% baseline, T2D: +20.8 ± 5.2% baseline, P < 0.05). peNOS/eNOS content was higher in Lean under basal conditions and, although not increased by insulin, remained higher in Lean during the insulin clamp than in obese T2D ( P < 0.05). ET-1 mRNA and peptide were 2.25 ± 0.50- and 1.52 ± 0.11-fold higher in obese T2D compared with Lean at baseline, and ET-1 peptide remained 2.02 ± 1.9-fold elevated in obese T2D after insulin infusion ( P < 0.05) but did not increase with insulin in either group ( P > 0.05). Obese non-T2D subjects tended to also display elevated basal ET-1 ( P = 0.06). In summary, higher basal skeletal muscle expression of ET-1 and reduced peNOS/eNOS may contribute to a reduced insulin-stimulated leg blood flow response in obese T2D patients. NEW & NOTEWORTHY Although impairments in endothelial signaling are hypothesized to reduce insulin-stimulated blood flow in type 2 diabetes (T2D), human studies examining these links are limited. We provide the first measures of nitric oxide synthase and endothelin-1 expression from skeletal muscle tissue containing native microvessels in individuals with and without T2D before and during insulin stimulation. Higher basal skeletal muscle expression of endothelin-1 and reduced endothelial nitric oxide phosphorylation (peNOS)/eNOS may contribute to reduced insulin-stimulated blood flow in obese T2D patients.

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    회원님의 원문열람 권한에 따라 열람이 불가능 할 수 있으며 권한이 없는 경우 해당 사이트의 정책에 따라 회원가입 및 유료구매가 필요할 수 있습니다.이동하는 사이트에서의 모든 정보이용은 NDSL과 무관합니다.

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  6. [해외논문]   Effect of increased and maintained frequency of speed endurance training on performance and muscle adaptations in runners   SCI SCIE

    Skovgaard, Casper (<sup>1</sup>Department of Nutrition, Exercise and Sports, Section of Integrated Physiology, University of Copenhagen, Copenhagen, Denmark) , Almquist, Nicki Winfield (and ) , Bangsbo, Jens (<sup>1</sup>Department of Nutrition, Exercise and Sports, Section of Integrated Physiology, University of Copenhagen, Copenhagen, Denmark)
    Journal of applied physiology v.122 no.1 ,pp. 48 - 59 , 2017 , 8750-7587 ,

    초록

    Ten speed endurance training (SET) sessions improved short-term exercise capacity and 10-km performance, which was followed by further improved short-term exercise capacity, but unchanged 10-km performance after 20 SET sessions performed with either high frequency (4 per 8 days) or continued low frequency (2 per 8 days) in trained runners. The further gain in short-term exercise capacity was associated with changes in muscle expression of proteins of importance for the development of fatigue. The aim of the study was, in runners accustomed to speed endurance training (SET), to examine the effect of increased and maintained frequency of SET on performance and muscular adaptations. After familiarization (FAM) to SET, 18 male ( n = 14) and female ( n = 4) runners (V̇ O 2max : 57.3 ± 3.4 ml/min; means ± SD) completed 20 sessions of maintained low-frequency (LF; every fourth day; n = 7) or high-frequency (HF; every second day; n = 11) SET. Before FAM as well as before and after an intervention period (INT), subjects completed a series of running tests and a biopsy from m. vastus lateralis was collected. Ten-kilometer performance improved ( P < 0.05) ~3.5% during FAM with no further change during INT. Time to exhaustion at 90% vV̇V̇ O 2max was 15 and 22% longer ( P < 0.05) during FAM and a further 12 and 16% longer ( P < 0.05) during INT in HF and LF, respectively. During FAM, muscle expression of NHE1 and maximal activity of citrate synthase (CS) and phosphofructokinase (PFK) increased ( P < 0.05), running economy (RE) improved ( P < 0.05), and V̇V̇V̇ O 2max was unchanged. During INT, both HF and LF increased ( P < 0.05) muscle expression of NKAβ1, whereas maximal activity of CS and PFK, RE, and V̇V̇V̇V̇ O 2max were unchanged. Furthermore, during INT, muscle expression of FXYD1 and SERCA1, and FXYD1 activity increased ( P < 0.05) in HF, while muscle expression of SERCA2 decreased ( P < 0.05) in LF. Thus increased or maintained frequency of SET leads to further improvements in short-term exercise capacity, but not in 10-km running performance. The better short-term exercise capacity may be associated with elevated expression of muscle proteins related to Na + /K + transportation and Ca 2+ reuptake. NEW & NOTEWORTHY Ten speed endurance training (SET) sessions improved short-term exercise capacity and 10-km performance, which was followed by further improved short-term exercise capacity, but unchanged 10-km performance after 20 SET sessions performed with either high frequency (4 per 8 days) or continued low frequency (2 per 8 days) in trained runners. The further gain in short-term exercise capacity was associated with changes in muscle expression of proteins of importance for the development of fatigue.

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    NDSL에서는 해당 원문을 복사서비스하고 있습니다. 아래의 원문복사신청 또는 장바구니담기를 통하여 원문복사서비스 이용이 가능합니다.

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  7. [해외논문]   Flow velocity is relatively uniform in the coronary sinusal venous tree: structure-function relation   SCI SCIE

    Wu, Hao (<sup>1</sup>Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing, People's Republic of China) , Kassab, Ghassan S. (<sup>3</sup>California Medical Innovations Institute, San Diego, California) , Tan, Wenchang (<sup>1</sup>Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing, People's Republic of China) , Huo, Yunlong (<sup>1</sup>Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing, People's Republic of China;)
    Journal of applied physiology v.122 no.1 ,pp. 60 - 67 , 2017 , 8750-7587 ,

    초록

    A hemodynamic model is developed in the entire coronary sinusal venous tree of the swine heart. A key finding is that the coronary sinusal venous system complies with the area preservation rule for efficient venous return while the coronary arterial tree obeys the minimum energy hypothesis. This model can also serve as a physiological reference state to test various therapeutic rationales through the venous route. The structure and function of coronary venous vessels are different from those of coronary arteries and are much less understood despite the therapeutic significance of coronary sinus interventions. Here we aimed to perform a hemodynamic analysis in the entire coronary sinusal venous tree, which enhances the understanding of coronary venous circulation. A hemodynamic model was developed in the entire coronary sinusal venous tree reconstructed from casts and histological data of five swine hearts. Various morphometric and hemodynamic parameters were determined in each vessel and analyzed in the diameter-defined Strahler system. The findings demonstrate an area preservation between the branches of the coronary venous system that leads to relatively uniform flow velocity in different orders of the venous tree. Pressure and circumferential and wall shear stresses decreased abruptly from the smallest venules toward vessels of order −5 (80.4 ± 39.1 µm) but showed a more modest change toward the coronary sinus. The results suggest that vessels of order −5 denote a hemodynamic transition from the venular bed to the transmural subnetwork. In contrast with the coronary arterial tree, which obeys the minimum energy hypothesis, the coronary sinusal venous system complies with the area-preserving rule for efficient venous return, i.e., da Vinci’s rule. The morphometric and hemodynamic model serves as a physiological reference state to test various therapeutic rationales through the venous route. NEW & NOTEWORTHY A hemodynamic model is developed in the entire coronary sinusal venous tree of the swine heart. A key finding is that the coronary sinusal venous system complies with the area preservation rule for efficient venous return while the coronary arterial tree obeys the minimum energy hypothesis. This model can also serve as a physiological reference state to test various therapeutic rationales through the venous route.

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  8. [해외논문]   A pilot study examining the impact of exercise training on skeletal muscle genes related to the TLR signaling pathway in older adults following hip fracture recovery   SCI SCIE

    McKenzie, Alec I. (<sup>1</sup>Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, Utah) , Briggs, Robert A. (<sup>1</sup>Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, Utah) , Barrows, Katherine M. (<sup>1</sup>Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, Utah) , Nelson, Daniel S. (<sup>2</sup>Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah) , Kwon, Oh Sung (<sup>1</sup>Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, Utah) , Hopkins, Paul N. (<sup>4</sup>Division of Cardiovascular Medicine, University of Utah, Salt Lake City, Utah) , Higgins, Thomas F. (and ) , Marcus, Robin L. (<sup>3</sup>Department of Orthopaedics, University of Utah, Salt Lake City, Utah) , Drummond, Micah J. (<sup>1</sup>Department of Physical Therapy and Athletic Training, University of Utah, Salt Lake City, Utah)
    Journal of applied physiology v.122 no.1 ,pp. 68 - 75 , 2017 , 8750-7587 ,

    초록

    These pilot data demonstrate that 3 mo of exercise training in older adults recovering from hip fracture surgery was able to mitigate skeletal muscle gene expression related to inflammation and ceramide metabolism while also improving surgical limb lean tissue, strength, and physical function. Older adults after hip fracture surgery experience progressive muscle atrophy and weakness, limiting full recovery. Further understanding of the molecular mechanisms in muscle with adaptation to exercise training in this vulnerable population is necessary. Therefore, we conducted a pilot study to investigate the skeletal muscle inflammatory and ceramide biosynthesis gene expression levels associated with the toll-like receptor (TLR) pathway before (Pre) and following a 3-mo multicomponent exercise training program in older adults (3M, 4F; 78.4 ± 13.3 yr; 25.5 ± 2.3 kg/m 2 ) ~4 mo after repair from hip fracture (HipFx). Vastus lateralis biopsies from the surgical limb were obtained before (Pre) and after training. Molecular end points and muscle function data were also compared with matched nonexercise healthy controls (CON). As a follow-up analysis, we evaluated specific sphingolipid pools in HipFx and CON muscle. Following training, quadriceps cross-sectional area, strength, and 6-min walk (6MW) increased in the surgical limb ( P < 0.05). Additionally, MYD88, TAK1, NFKB1, IL6, SPT2, and CERS1 gene expression decreased after training ( P ≤ 0.05), but some remained elevated above CON levels. Interestingly, MYD88 mRNA was inversely correlated to quadriceps CSA, strength, and 6MW. Finally, muscle dihydroceramides and phosphoceramides in HipFx were lower than CON at Pre ( P ≤ 0.05), but after training differences from CON were removed. Together, our pilot data support that exercise training alters skeletal muscle inflammation and ceramide metabolism associated with TLR signaling in older adults recovering from hip fracture surgery and may be related to improvements in muscle function recovery. NEW & NOTEWORTHY These pilot data demonstrate that 3 mo of exercise training in older adults recovering from hip fracture surgery was able to mitigate skeletal muscle gene expression related to inflammation and ceramide metabolism while also improving surgical limb lean tissue, strength, and physical function.

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  9. [해외논문]   Intermittent parathyroid hormone administration attenuates endothelial dysfunction in old rats   SCI SCIE

    Guers, John J. (Department of Kinesiology & Applied Physiology, University of Delaware, Newark, Delaware ) , Prisby, Rhonda D. (Department of Kinesiology & Applied Physiology, University of Delaware, Newark, Delaware ) , Edwards, David G. (Department of Kinesiology & Applied Physiology, University of Delaware, Newark, Delaware ) , Lennon-Edwards, Shannon (Department of Kinesiology & Applied Physiology, University of Delaware, Newark, Delaware)
    Journal of applied physiology v.122 no.1 ,pp. 76 - 81 , 2017 , 8750-7587 ,

    초록

    We have demonstrated that intermittent parathyroid hormone administration can rescue age-related vascular dysfunction by improving endothelial-dependent dilation in the aorta of older rodents. This demonstrates a novel potential benefit of parathyroid hormone administration in aging. Aging is an independent risk factor for cardiovascular disease and is characterized by a decline in endothelial function. Parathyroid hormone (PTH) administration has been shown to increase endothelial nitric oxide synthase (eNOS) expression. The purpose of this investigation was to determine the effect of intermittent PTH administration on aortic endothelial function in old rodents. We hypothesized that intermittent PTH administration would improve endothelial function in older rodents. Old (24-mo-old) and young (4-mo-old) Fischer-344 rats were given 10 injections of PTH 1–34 (43 μg·kg −1 ·day −1 ) or phosphate-buffered saline (100 μl/day) over 15 days. Endothelium-dependent relaxation of aortic rings in response to acetylcholine (10 −9 to 10 −5 M) was significantly impaired in old control (OC) compared with young control (YC) as indicated by a reduced area under the curve (AUC, 100 ± 6.28 vs. 54.08 ± 8.3%; P < 0.05) and impaired maximal relaxation (E max , 70.1 ± 4.48 vs. 92.9 ± 4.38%; P < 0.05). E max was improved in old animals treated with PTH (OPTH) (OC, 70.1 ± 4.48 vs. OPTH, 85 ± 7.48%; P < 0.05) as well as AUC (OC, 54.08 ± 8.3 vs. OPTH, 82.5 ± 5.7%; P < 0.05) while logEC 50 was not different. Endothelial-independent relaxation in response to sodium nitroprusside was not different among groups. Aortic eNOS protein expression was significantly decreased in OC compared with YC ( P < 0.05). PTH treatment restored eNOS expression in OPTH animals ( P < 0.05). These data suggest that PTH may play a role in attenuating age-related impairments in aortic endothelial function. NEW & NOTEWORTHY We have demonstrated that intermittent parathyroid hormone administration can rescue age-related vascular dysfunction by improving endothelial-dependent dilation in the aorta of older rodents. This demonstrates a novel potential benefit of parathyroid hormone administration in aging.

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  10. [해외논문]   Nasal high-flow therapy reduces work of breathing compared with oxygen during sleep in COPD and smoking controls: a prospective observational study   SCI SCIE

    Biselli, Paolo J. C. (<sup>1</sup>Johns Hopkins Sleep Disorder Center, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland) , Kirkness, Jason P. (<sup>1</sup>Johns Hopkins Sleep Disorder Center, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland) , Grote, Ludger (<sup>3</sup>Center of Sleep and Vigilance Disorders, Department of Internal Medicine and Clinical Nutrition, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden ) , Fricke, Kathrin (<sup>1</sup>Johns Hopkins Sleep Disorder Center, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland) , Schwartz, Alan R. (<sup>1</sup>Johns Hopkins Sleep Disorder Center, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland) , Smith, Philip (<sup>1</sup>Johns Hopkins Sleep Disorder Center, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland) , Schneider, Hartmut (<sup>1</sup>Johns Hopkins Sleep Disorder Center, Division of Pulmonary and Critical)
    Journal of applied physiology v.122 no.1 ,pp. 82 - 88 , 2017 , 8750-7587 ,

    초록

    Nasal high-flow (NHF) therapy can support ventilation in patients with chronic obstructive pulmonary disease during sleep by decreasing the work of breathing and improving CO 2 levels. On the other hand, oxygen supplementation corrects hypoxemia, but it produces only a minimal reduction in work of breathing and is associated with increased CO 2 levels. Therefore, NHF can be a useful method to assist ventilation in patients with increased respiratory mechanical loads. Patients with chronic obstructive pulmonary disease (COPD) endure excessive resistive and elastic loads leading to chronic respiratory failure. Oxygen supplementation corrects hypoxemia but is not expected to reduce mechanical loads. Nasal high-flow (NHF) therapy supports breathing by reducing dead space, but it is unclear how it affects mechanical loads of patients with COPD. The objective of this study was to compare the effects of low-flow oxygen and NHF therapy on ventilation and work of breathing (WOB) in patients with COPD and controls during sleep. Patients with COPD ( n = 12) and controls ( n = 6) were recruited and submitted to polysomnography to measure sleep parameters and ventilation in response to administration of oxygen and NHF. A subset of six patients also had an esophageal catheter inserted for the purpose of measuring WOB. Patients with COPD had similar minute ventilation (ããV̇ E ) but lower tidal volumes than matched controls. With oxygen, [Formula]was increased and ããV̇V̇ E was reduced in both controls and patients with COPD, but there was an increase in transcutaneous CO 2 levels. NHF produced a greater reduction in ããV̇V̇V̇ E and was associated with a reduction in CO 2 levels. Although NHF halved WOB, oxygen produced only a minor reduction in this parameter. We conclude that oxygen produced little change in WOB, which was associated with CO 2 elevations. On the other hand, NHF produced a large reduction in ããV̇V̇V̇V̇ E and WOB with a concomitant decrease in CO 2 levels. Our data indicate that NHF improves alveolar ventilation during sleep compared with oxygen and room air in patients with COPD and therefore can decrease their cost of breathing. NEW & NOTEWORTHY Nasal high-flow (NHF) therapy can support ventilation in patients with chronic obstructive pulmonary disease during sleep by decreasing the work of breathing and improving CO 2 levels. On the other hand, oxygen supplementation corrects hypoxemia, but it produces only a minimal reduction in work of breathing and is associated with increased CO 2 levels. Therefore, NHF can be a useful method to assist ventilation in patients with increased respiratory mechanical loads.

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