Muscle size and strength : debunking the “completely separate phenomena” suggestion

This is a post-peer-review, pre-copyedit version of an article published in European Journal of Applied Physiology. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00421-017-3616-

Tendinous tissue properties after short and long-term functional overload: Differences between controls, 12 weeks and 4 years of resistance training.

AIM: The potential for tendinous tissues to adapt to functional overload, especially after several years of exposure to heavy resistance training is largely unexplored. This study compared the morphological and mechanical characteristics of the patellar tendon and knee-extensor tendon-aponeurosis complex between young men exposed to long-term (4 years; n=16), short-term (12 weeks; n=15) and no (untrained controls; n=39) functional overload in the form of heavy resistance training. METHODS: Patellar tendon cross-sectional area, vastus-lateralis aponeurosis area and quadriceps femoris volume, plus patellar tendon stiffness and Young's modulus, and tendon-aponeurosis complex stiffness, were quantified with MRI, dynamometry and ultrasonography. RESULTS: As expected long-term trained had greater muscle strength and volume (+58% and +56% vs untrained, both P<0.001), as well as a greater aponeurosis area (+17% vs untrained, P<0.01), but tendon cross-sectional area (mean and regional) was not different between groups. Only long-term trained had reduced patellar tendon elongation/strain over the whole force/stress range, whilst both short-term and long-term overload groups had similarly greater stiffness/Young's modulus at high force/stress (short-term +25/22%, and long-term +17/23% vs untrained; all P<0.05). Tendon-aponeurosis complex stiffness was not different between groups (ANOVA, P = 0.149). CONCLUSION: Despite large differences in muscle strength and size, years of resistance training did not induce tendon hypertrophy. Both short-term and long-term overload, demonstrated similar increases in high force mechanical and material stiffness, but reduced elongation/strain over the whole force/stress range occurred only after years of overload, indicating a force/strain specific time-course to these adaptations. This article is protected by copyright. All rights reserved

Tendinous tissue adaptation to explosive- vs. sustained-contraction strength training

© 2018 Massey, Balshaw, Maden-Wilkinson, Tillin and Folland. The effect of different strength training regimes, and in particular training utilizing brief explosive contractions, on tendinous tissue properties is poorly understood. This study compared the efficacy of 12 weeks of knee extensor explosive-contraction (ECT; n = 14) vs. sustained-contraction (SCT; n = 15) strength training vs. a non-training control (n = 13) to induce changes in patellar tendon and knee extensor tendon-aponeurosis stiffness and size (patellar tendon, vastus-lateralis aponeurosis, quadriceps femoris muscle) in healthy young men. Training involved 40 isometric knee extension contractions (three times/week): gradually increasing to 75% of maximum voluntary torque (MVT) before holding for 3 s (SCT), or briefly contracting as fast as possible to ~80% MVT (ECT). Changes in patellar tendon stiffness and Young's modulus, tendon-aponeurosis complex stiffness, as well as quadriceps femoris muscle volume, vastus-lateralis aponeurosis area and patellar tendon cross-sectional area were quantified with ultrasonography, dynamometry, and magnetic resonance imaging. ECT and SCT similarly increased patellar tendon stiffness (20% vs. 16%, both p < 0.05 vs. control) and Young's modulus (22% vs. 16%, both p < 0.05 vs. control). Tendon-aponeurosis complex high-force stiffness increased only after SCT (21%; p < 0.02), while ECT resulted in greater overall elongation of the tendon-aponeurosis complex. Quadriceps muscle volume only increased after sustained-contraction training (8%; p = 0.001), with unclear effects of strength training on aponeurosis area. The changes in patellar tendon cross-sectional area after strength training were not appreciably different to control. Our results suggest brief high force muscle contractions can induce increased free tendon stiffness, though SCT is needed to increase tendon-aponeurosis complex stiffness and muscle hypertrophy

White Blood Cell Differentials Enrich Whole Blood Expression Data in the Context of Acute Cardiac Allograft Rejection

Acute cardiac allograft rejection is a serious complication of heart transplantation. Investigating molecular processes in whole blood via microarrays is a promising avenue of research in transplantation, particularly due to the non-invasive nature of blood sampling. However, whole blood is a complex tissue and the consequent heterogeneity in composition amongst samples is ignored in traditional microarray analysis. This complicates the biological interpretation of microarray data. Here we have applied a statistical deconvolution approach, cell-specific significance analysis of microarrays (csSAM), to whole blood samples from subjects either undergoing acute heart allograft rejection (AR) or not (NR). We identified eight differentially expressed probe-sets significantly correlated to monocytes (mapping to 6 genes, all down-regulated in ARs versus NRs) at a false discovery rate (FDR) ≤ 15%. None of the genes identified are present in a biomarker panel of acute heart rejection previously published by our group and discovered in the same data***

Calmodulin Binding and Inhibition of Cardiac Muscle Calcium Release Channel (Ryanodine Receptor)

Metabolically (35)S-labeled calmodulin (CaM) was used to determine the CaM binding properties of the cardiac ryanodine receptor (RyR2) and to identify potential channel domains for CaM binding. In addition, regulation of RyR2 by CaM was assessed in [(3)H]ryanodine binding and single-channel measurements. Cardiac sarcoplasmic reticulum vesicles bound approximately four CaM molecules per RyR2 tetramer in the absence of Ca(2+); in the presence of 100 microm Ca(2+), the vesicles bound 7.5 CaM molecules per tetramer. Purified RyR2 bound approximately four [(35)S]CaM molecules per RyR tetramer, both in the presence and absence of Ca(2+). At least four CaM binding domains were identified in [(35)S]CaM overlays of fusion proteins spanning the full-length RyR2. The affinity (but not the stoichiometry) of CaM binding was altered by redox state as controlled by the presence of either GSH or GSSG. Inhibition of RyR2 activity by CaM was influenced by Ca(2+) concentration, redox state, and other channel modulators. Parallel experiments with the skeletal muscle isoform showed major differences in the CaM binding properties and regulation by CaM of the skeletal and cardiac ryanodine receptors

What makes long-term resistance-trained individuals so strong? A comparison of skeletal muscle morphology, architecture, and joint mechanics.

The greater muscular strength of long-term resistance-trained (LTT) individuals is often attributed to hypertrophy but the role of other factors, notably maximum voluntary specific tension (ST), muscle architecture and any differences in joint mechanics (moment arm) have not been documented. The aim of the present study was to examine the musculoskeletal factors that might explain the greater Quadriceps strength and size of LTT vs untrained (UT) individuals. LTT (n = 16, age 21.6 ± 2.0 years) had 4.0 ± 0.8 years of systematic knee extensor heavy-resistance training experience, whereas UT (n = 52; age 25.1 ± 2.3 years) had no lower-body resistance training experience for > 18 months. Knee extension dynamometry, T1-weighted magnetic resonance images of the thigh and knee and ultrasonography of the Quadriceps muscle group at 10 locations were used to determine Quadriceps: isometric maximal voluntary torque (MVT), muscle volume (QVOL), patella tendon moment arm (PTMA), pennation angle (QΘP) and fascicle length (QFL), physiological cross-sectional area (QPCSA) and ST. LTT had substantially greater MVT (+60% vs UT, P<0.001) and QVOL (+56%, P<0.001) and QPCSA (+41%, P<0.001) but smaller differences in ST (+9%, P<0.05) and moment arm (+4%, P<0.05), and thus muscle size was the primary explanation for the greater strength of LTT. The greater muscle size (volume) of LTT was primarily attributable to the greater QPCSA (+41%; indicating more sarcomeres in parallel) rather than the more modest difference in FL (+11%; indicating more sarcomeres in series). There was no evidence for regional hypertrophy after LTT

Changes in agonist neural drive, hypertrophy and pre-training strength all contribute to the individual strength gains after resistance training

© 2017 The Author(s)Purpose: Whilst neural and morphological adaptations following resistance training (RT) have been investigated extensively at a group level, relatively little is known about the contribution of specific physiological mechanisms, or pre-training strength, to the individual changes in strength following training. This study investigated the contribution of multiple underpinning neural [agonist EMG (QEMGMVT), antagonist EMG (HEMGANTAG)] and morphological variables [total quadriceps volume (QUADSVOL), and muscle fascicle pennation angle (QUADSθp)], as well as pre-training strength, to the individual changes in strength after 12 weeks of knee extensor RT. Methods: Twenty-eight healthy young men completed 12 weeks of isometric knee extensor RT (3/week). Isometric maximum voluntary torque (MVT) was assessed pre- and post-RT, as were simultaneous neural drive to the agonist (QEMGMVT) and antagonist (HEMGANTAG). In addition QUADSVOL was determined with MRI and QUADSθp with B-mode ultrasound. Results: Percentage changes (∆) in MVT were correlated to ∆QEMGMVT (r = 0.576, P = 0.001), ∆QUADSVOL (r = 0.461, P = 0.014), and pre-training MVT (r = −0.429, P = 0.023), but not ∆HEMGANTAG (r = 0.298, P = 0.123) or ∆QUADSθp (r = −0.207, P = 0.291). Multiple regression analysis revealed 59.9% of the total variance in ∆MVT after RT to be explained by ∆QEMGMVT (30.6%), ∆QUADSVOL (18.7%), and pre-training MVT (10.6%). Conclusions: Changes in agonist neural drive, quadriceps muscle volume and pre-training strength combined to explain the majority of the variance in strength changes after knee extensor RT (~60%) and adaptations in agonist neural drive were the most important single predictor during this short-term intervention

Integrating Western and non-Western cultural expressions to further cultural and creative tourism: a case study

The term cultural industries was coined more than half a century ago, but at the beginning of the twenty-first century, the broader concept of creative industries, covering a wide range of cultural, design and digital activity, captured the imagination of public policymakers at national and city levels. Paralleling these developments has been the recognition of the phenomenon of cultural tourism and, more recently, the emergence of the idea of creative tourism, that is, tourism programmes designed to engage tourists actively in cultural activity. This paper presents a case study of a creative tourism event which took place in 2012 in the City of Manchester in the UK. The festival, which celebrated West African culture, utilised existing cultural institutions of the city and drew on the talents of local and visiting members of West African community to engage not only tourists but also indigenous and Black and Minority Ethnic (BME) residents of Manchester in a variety of cultural activities. It thus used the focus of creative tourism to seek to foster community and cultural development as well as tourism

Randomized Controlled Ferret Study to Assess the Direct Impact of 2008–09 Trivalent Inactivated Influenza Vaccine on A(H1N1)pdm09 Disease Risk

During spring-summer 2009, several observational studies from Canada showed increased risk of medically-attended, laboratory-confirmed A(H1N1)pdm09 illness among prior recipients of 2008–09 trivalent inactivated influenza vaccine (TIV). Explanatory hypotheses included direct and indirect vaccine effects. In a randomized placebo-controlled ferret study, we tested whether prior receipt of 2008–09 TIV may have directly influenced A(H1N1)pdm09 illness. Thirty-two ferrets (16/group) received 0.5 mL intra-muscular injections of the Canadian-manufactured, commercially-available, non-adjuvanted, split 2008–09 Fluviral or PBS placebo on days 0 and 28. On day 49 all animals were challenged (Ch0) with A(H1N1)pdm09. Four ferrets per group were randomly selected for sacrifice at day 5 post-challenge (Ch+5) and the rest followed until Ch+14. Sera were tested for antibody to vaccine antigens and A(H1N1)pdm09 by hemagglutination inhibition (HI), microneutralization (MN), nucleoprotein-based ELISA and HA1-based microarray assays. Clinical characteristics and nasal virus titers were recorded pre-challenge then post-challenge until sacrifice when lung virus titers, cytokines and inflammatory scores were determined. Baseline characteristics were similar between the two groups of influenza-naïve animals. Antibody rise to vaccine antigens was evident by ELISA and HA1-based microarray but not by HI or MN assays; virus challenge raised antibody to A(H1N1)pdm09 by all assays in both groups. Beginning at Ch+2, vaccinated animals experienced greater loss of appetite and weight than placebo animals, reaching the greatest between-group difference in weight loss relative to baseline at Ch+5 (7.4% vs. 5.2%; p = 0.01). At Ch+5 vaccinated animals had higher lung virus titers (log-mean 4.96 vs. 4.23pfu/mL, respectively; p = 0.01), lung inflammatory scores (5.8 vs. 2.1, respectively; p = 0.051) and cytokine levels (p&gt;0.05). At Ch+14, both groups had recovered. Findings in influenza-naïve, systematically-infected ferrets may not replicate the human experience. While they cannot be considered conclusive to explain human observations, these ferret findings are consistent with direct, adverse effect of prior 2008–09 TIV receipt on A(H1N1)pdm09 illness. As such, they warrant further in-depth investigation and search for possible mechanistic explanations