Residual Force Enhancement Is Attenuated in a Shortening Magnitude-dependent Manner

Introduction The isometric force attained after active stretch is greater than that attained in a purely isometric contraction. This property is referred to as residual force enhancement (RFE). Although RFE is thought to contribute to the enhanced force and power in stretch-shortening cycles (SSCs), it is unclear whether shortening that occurs after active stretch eliminates the RFE induced by active stretch. Therefore, we evaluated the influence of shortening on RFE. Methods Skinned rabbit soleus fibers (N = 43) were used for all tests. Residual force enhancement was compared between the stretch-only condition and the SSC condition. In the SSC conditions, shortening magnitudes were either 1% or 12.5% of fiber length. The final muscle length where RFE was evaluated was 3 μm for all trials. In the SSCs with 12.5% shortening, the isometric force before and after the SSC was also compared. Results Residual force enhancement was similar between the stretch only (7.9% ± 2.7%) and the SSC with 1% shortening condition (7.1% ± 2.9%) (P = 0.316), whereas RFE was smaller in the SSC with 12.5% shortening (3.5% ± 2.4%) than the stretch-only condition (8.4% ± 2.5%) (P

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Moderate Exercise Enhances Endothelial Progenitor Cell Exosomes Release and Function

Purpose Exercise has cardiovascular benefits which might be related to endothelial progenitor cells (EPC). Meanwhile, there is evidence suggesting that EPC-derived exosomes (EPC-EX) promote vascular repair and angiogenesis through their carried microRNA (miR)-126. In this study, we investigated whether exercise could increase the levels of circulating EPC-EX and their miR-126 cargo, and by which promote the protective function of EPC-EX on endothelial cells (EC). Methods Plasma EPC-EX from sedentary, low, or moderate exercise mice, respectively, denoted as EPC-EXS, EPC-EXL, and EPC-EXM, were isolated using microbead-based sorting techniques and characterized by nanoparticle tracking analysis, Western blot, and quantitative real-time polymerase chain reaction assessments of biomarkers and miR-126. High glucose (25 mM) with hypoxia (1% O2) was used for inducing an EC injury model. The injured EC were treated by coculturing with vehicle, EPC-EXS, EPC-EXL, EPC-EXM, or EPC-EXM + anti–miR-126. After that, EC were used for flow cytometry analysis of apoptosis, assessments of tube formation and migration, and measurements of miR-126 level and its downstream sprouty-related protein-1 (SPRED1) and vascular endothelial growth factor (VEGF). Results 1) Isolated EPC-EX positively expressed exosomal markers (CD63 and Tsg101) and EPC markers (CD34 and VEGFR2). 2) Exercise intensity dependently elevated plasma level of EPC, EPC-EX/EPC ratio, and miR-126 expression in EPC and EPC-EX. 3) Injured EC displayed apoptosis increment, angiogenic dysfunction and miR-126 reduction. 4) EPC-EXM had better effects than EPC-EXS and EPC-EXL on alleviating those changes of injured EC, accompanied with SPRED1 downregulation and VEGF upregulation. 5) The effects of EPC-EXM were abolished by miR-126 knockdown. Conclusions Our data demonstrate that exercise can increase EPC-EX release and miR-126 level and enhance the effects of EPC-EX on protecting EC against injury through the SPRED1/VEGF pathway.

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Physical Activity Levels Predict Exercise-induced Hypoalgesia in Older Adults

Prior research indicates that older adults exhibit a deficient capacity to activate multiple pain inhibitory mechanisms, including pain inhibition after acute exercise termed exercise-induced hypoalgesia (EIH). The influence of physical activity levels and psychological processes on EIH in older adults remains unclear. Purpose This study examined potential psychological and physical activity predictors of the magnitude of EIH after submaximal isometric exercise in healthy older adult men and women. Methods Fifty-two healthy older adults completed a test of EIH, the Pain Catastrophizing Scale, the Tampa Scale of Kinesiophobia, and wore an accelerometer on the hip for 1 wk to assess physical activity levels. For the test of EIH, participants complete a 3-min isometric handgrip at 25% of maximum voluntary contraction. Pressure pain thresholds (PPT) and a 30-s continuous heat pain test were completed before and immediately after the exercise. Results Mixed-model ANOVA revealed that older adults demonstrated significantly decreased PPT after isometric exercise (P = 0.030), and no changes on the heat pain trials from pretest to posttest (P > 0.05). A multiple regression revealed that accumulated moderate to vigorous physical activity (MVPA) per week significantly predicted the change in PPT after exercise (β = 0.35, P = 0.012). Participants who averaged greater MVPA experienced a greater increase in PPT after exercise. No relationships were found with EIH and the psychological variables. Conclusions Older adults did not exhibit EIH after submaximal isometric exercise. However, those who did more MVPA per week experienced a greater magnitude of pain inhibition after acute exercise.

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Nivolumab induced encephalopathy in a man with metastatic renal cell cancer: a case report

Great progress has recently been made in the treatment of metastatic renal cell carcinoma, including the introduction of nivolumab, an immune checkpoint inhibitor. Despite promising results, this treatment bri...

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Auch Melanompatienten mit Hirnmetastasen profitieren von neuen Behandlungsmethoden

Moderne Therapeutika haben das Leben von Melanompatienten verlängert. Ob und in welchem Ausmaß das auch für Patienten mit Hirnmetastasen zutrifft, wurde nun anhand von Beobachtungsdaten analysiert.

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Biopsie der Sentinellymphknoten: prognostischer Wert bei Melanomen fraglich

Eine Biopsie der Sentinellymphknoten ist neben der Beurteilung der Tumordicke nach Breslow eine zweite gängige Methode, bei Melanomen Informationen zu Stadium und Prognose zu sammeln. Ob der Befund tatsächlich zusätzliche prognostische Informationen liefert, wurde nunin einer retrospektiven Studie untersucht.

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