Effects of a Cycling versus Running HIIT Program on Fat Mass Loss and Gut Microbiota Composition in Men with Overweight/Obesity

PURPOSE

High-intensity interval training (HIIT) can efficiently decrease total and (intra-)abdominal fat mass (FM); however, the effects of running versus cycling HIIT programs on FM reduction have not been compared yet. In addition, the link between HIIT-induced FM reduction and gut microbiota must be better investigated. The aim of this study was to compare the effects of two 12-wk HIIT isoenergetic programs (cycling vs running) on body composition and fecal microbiota composition in nondieting men with overweight or obesity.

METHODS

Sixteen men (age, 54.2 ± 9.6 yr; body mass index, 29.9 ± 2.3 kg·m -2 ) were randomly assigned to the HIIT-BIKE (10 × 45 s at 80%-85% of maximal heart rate, 90-s active recovery) or HIIT-RUN (9 × 45 s at 80%-85% of maximal heart rate, 90-s active recovery) group (3 times per week). Dual-energy x-ray absorptiometry was used to determine body composition. Preintervention and postintervention fecal microbiota composition was analyzed by 16S rRNA gene sequencing, and diet was controlled.

RESULTS

Overall, body weight, and abdominal and visceral FM decreased over time ( P < 0.05). No difference was observed for weight, total body FM, and visceral FM between groups (% change). Conversely, abdominal FM loss was greater in the HIIT-RUN group (-16.1% vs -8.3%; P = 0.050). The α-diversity of gut microbiota did not vary between baseline and intervention end and between groups, but was associated with abdominal FM change ( r = -0.6; P = 0.02). The baseline microbiota profile and composition changes were correlated with total and abdominal/visceral FM losses.

CONCLUSIONS

Both cycling and running isoenergetic HIIT programs improved body composition in men with overweight/obesity. Baseline intestinal microbiota composition and its postintervention variations were correlated with FM reduction, strengthening the possible link between these parameters. The mechanisms underlying the greater abdominal FM loss in the HIIT-RUN group require additional investigations.

Neuromuscular and Metabolic Responses during Repeated Bouts of Loaded Downhill Walking

INTRODUCTION

The aim of this study was to compare vastus lateralis (VL) and rectus femoris (RF) muscles for their nervous and mechanical adaptations during two bouts of downhill walking (DW) with load carriage performed 2 wk apart. Moreover, we investigated cardiometabolic and perceived exertion responses during both DW bouts.

METHODS

Seventeen participants performed two 45-min sessions of loaded DW (30% of body mass; slope, -25%; speed, 4.5 km·h -1 ) separated by 2 wk. Rating of perceived exertion, cost of walking, heart rate, and EMG activity of thigh muscles were assessed during the DW. Muscle shear elastic modulus ( μ ) of RF and VL were assessed before each exercise bout. Maximal voluntary contraction torque was assessed before (PRE), immediately after (POST), and 24 and 48 h after the two exercise bouts.

RESULTS

Maximal voluntary contraction torque decreased from POST (-23.7% ± 9.2%) to 48 h (-19.2% ± 11.9%) after the first exercise (Ex1), whereas it was significantly reduced only at POST (-14.6% ± 11.0%) after the second exercise (Ex2; P < 0.001). Rating of perceived exertion (Ex1: 12.3 ± 1.9; Ex2: 10.8 ± 2.0), heart rate (Ex1: 156 ± 23 bpm; Ex2: 145 ± 25 bpm), cost of walking (Ex1: 4.5 ± 0.9 J·m -1 ·kg -1 ; Ex2: 4.1 ± 0.7 J·m -1 ·kg -1 ), and RF EMG activity (Ex1: 0.071 ± 0.028 mV; Ex2: 0.041 ± 0.014 mV) were significantly decreased during Ex2 compared with Ex1 ( P < 0.01). RF μ was significantly greater in Ex2 (0.44 ± 0.18) compared with Ex1 (0.56 ± 0.27; P < 0.001).

CONCLUSIONS

The RF muscle displayed specific mechanical and nervous adaptations to repeated DW bouts as compared with VL. Moreover, the muscle adaptations conferred by the first bout of DW could have induced greater exercise efficiency, inducing lesser perceived exertion and cardiometabolic demand when the same exercise was repeated 2 wk later.

Fe-Ni-based alloys as highly active and low-cost oxygen evolution reaction catalyst in alkaline media

NiFe-based oxo-hydroxides are highly active for the oxygen evolution reaction but require complex synthesis and are poorly durable when deposited on foreign supports. Herein we demonstrate that easily processable, Earth-abundant and cheap Fe-Ni alloys spontaneously develop a highly active NiFe oxo-hydroxide surface, exsolved upon electrochemical activation. While the manufacturing process and the initial surface state of the alloys do not impact the oxygen evolution reaction performance, the growth/composition of the NiFe oxo-hydroxide surface layer depends on the alloying elements and initial atomic Fe/Ni ratio, hence driving oxygen evolution reaction activity. Whatever the initial Fe/Ni ratio of the Fe-Ni alloy (varying between 0.004 and 7.4), the best oxygen evolution reaction performance (beyond that of commercial IrO2) and durability was obtained for a surface Fe/Ni ratio between 0.2 and 0.4 and includes numerous active sites (high NiIII/NiII capacitive response) and high efficiency (high Fe/Ni ratio). This knowledge paves the way to active and durable Fe-Ni alloy oxygen-evolving electrodes for alkaline water electrolysers.

Is Physical Activity an Efficient Strategy to Control the Adverse Effects of Persistent Organic Pollutants in the Context of Obesity? A Narrative Review

Obesity affects nearly 660 million adults worldwide and is known for its many comorbidities. Although the phenomenon of obesity is not fully understood, science regularly reveals new determinants of this pathology. Among them, persistent organic pollutants (POPs) have been recently highlighted. Mainly lipophilic, POPs are normally stored in adipose tissue and can lead to adverse metabolic effects when released into the bloodstream. The main objective of this narrative review is to discuss the different pathways by which physical activity may counteract POPs' adverse effects. The research that we carried out seems to indicate that physical activity could positively influence several pathways negatively influenced by POPs, such as insulin resistance, inflammation, lipid accumulation, adipogenesis, and gut microbiota dysbiosis, that are associated with the development of obesity. This review also indicates how, through the controlled mobilization of POPs, physical activity could be a valuable approach to reduce the concentration of POPs in the bloodstream. These findings suggest that physical activity should be used to counteract the adverse effects of POPs. However, future studies should accurately assess its impact in specific situations such as bariatric surgery, where weight loss promotes POPs' blood release.

Combined Endurance and Strength or Only Endurance Training? Effects of Training Mode on Neuromuscular Characteristics and Functional Abilities in Obese Adolescent Girls Enrolled in a Weight-Reduction Program

The aim of the present study was to examine whether combining strength and endurance training would promote better improvements in neuromuscular characteristics and functional abilities than endurance training alone in obese adolescent girls enrolled in a weight-reduction program. Twenty-four obese adolescent girls (12-15 years) volunteered to participate in a 9-month training program. Participants were allocated into two groups following either (i) combined training (endurance + strength; E+ST) or (ii) endurance training (ET) program. Absolute and specific maximal torque, muscle size, and maximal voluntary activation level (VA) of the knee extensor (KE) and plantar flexor (PF) muscles were assessed. Moreover, functional abilities such as balance and fatigability during a maximal isometric intermittent contraction test of the KE muscles were measured before and after the intervention. The force of the adductor pollicis (AP) muscles was used as a control to account for any effect of growth or mechanical unloading on neuromuscular properties and muscle size. While absolute and specific torque of the KE (+14.7 ± 12.1% and +14.4 ± 15.5%; p < 0.05) and PF (+19.2 ± 16.7% and +18.3 ± 17.5%; p < 0.001) muscles increased in the E+ST group, PF torque decreased, and KE torque did not change in the ET group (-22.6 ± 10.5% and -15.0 ± 17.2%; p < 0.001). Moreover, the VA of the KE muscles increased for the E+ST (+6.1 ± 5.6%; p < 0.01) group and decreased for the ET group (-5.4 ± 5.4%; p < 0.05). In contrast, VA remained similar in the PF muscles for both groups. The number of repetitions during the fatigability test increased in the ET group (38.4 ± 22.3 vs. 84.1 ± 33.3; p = 0.032) and was unchanged in the E+ST group (50.8 ± 14.1 vs. 54.2 ± 37.8), but it was associated with a higher force level. Moreover, balance improved in the E+ST group, but not in the ET group. To conclude, physical training combining strength and endurance training promoted larger improvement in neuromuscular characteristics and functional abilities than endurance training alone in obese adolescent girls. Greater neuromuscular adaptations resulting from the E+ST training may be beneficial for preserving or even increasing functional abilities and possibly induce greater engagement in the active lifestyle of obese adolescents. However, the endurance component seems necessary in training programs to reduce fatigability during daily living activities.

Sex-Related Neuromuscular Adaptations to Youth Obesity: Force, Muscle Mass, and Neural Issues

Young obese are generally stronger than their typically developing counterparts. Strength differences could be partly ascribed to nervous adaptations, due to the loading effect of carrying overweight. We hypothesized that central adaptations of the muscles highly involved in weight bearing, i.e., plantar flexors (PF) and knee extensors (KE) could be greater in girls than boys due to their reduced potential for muscle hypertrophy. Furthermore, it is possible that neuromuscular adaptations in weight-bearing muscles will be greater compared to the unloaded muscles such as the adductor pollicis (AP).Twenty-four non-obese and 21 obese (body mass index: 33 ± 4 kg·m-2) adolescent girls and boys (12-15 years) performed maximal voluntary isometric contractions (MVC) of the PF and KE muscles. Voluntary activation (VA), assessed with the twitch interpolation technique, the antagonist co-activation (Co-Act) level, and the normalized root-mean-square value (RMS) of the agonist muscles were measured to account for central adaptations.The results revealed a weight status effect (p < 0.001) on the absolute MVC torque and VA of both KE and PF muscles. Moreover, these differences were also related to the sex of the participants (p < 0.05) for the PF muscles. While the VA, absolute, and specific MVC torque were greater in obese compared with non-obese girls, no difference was found between boys. A similar Co-Act level was observed between groups, whatever the sex and muscle group considered. Finally, no significant differences were found for the AP regarding peripheral and neural factors.This study highlighted a favorable effect of obesity on the central mechanisms (i.e., VA) responsible for force production within the lower limb muscles. However, obesity-related central adaptation was only observed in girls for the PF muscles. Thus, the excess of body mass supported by the muscles involved in weight-bearing could act as a chronic training stimulus responsible for these adaptations in obese adolescents but mostly in girls.

Exploring Serum Biomarkers for Neuropathic Pain in Rat Models of Chemotherapy-Induced Peripheral Neuropathy: A Comparative Pilot Study with Oxaliplatin, Paclitaxel, Bortezomib, and Vincristine

Blood biomarkers, including neurofilament light chain (NfL), have garnered attention as potential indicators for chemotherapy-induced peripheral neuropathy (CIPN), a dose-limiting adverse effect of neurotoxic anticancer drugs. However, no blood biomarker has been established for routine application or translational research. This pilot study aimed to evaluate a limited panel of blood biomarkers in rat models of CIPN and their correlations with neuropathic pain. CIPN models were induced through repeated injections of oxaliplatin, paclitaxel, bortezomib, and vincristine. Electronic von Frey testing was used to assess tactile allodynia. Post anticancer injections, serum concentrations of 31 proteins were measured. Allodynia thresholds decreased in anticancer-treated animals compared to controls. No consistent modifications were observed in the biomarkers across CIPN models. The most noteworthy biomarkers with increased concentrations in at least two CIPN models were NfL (paclitaxel, vincristine), MCP-1, and RANTES (oxaliplatin, vincristine). Vincristine-treated animals exhibited strong correlations between LIX, MCP-1, NfL, and VEGF concentrations and tactile allodynia thresholds. No single biomarker can be recommended as a unique indicator of CIPN-related pain. Because of the study limitations (single dose of each anticancer drug, young animals, and single time measurement of biomarkers), further investigations are necessary to define the kinetics, specificities, and sensitivities of MCP-1, RANTES, and NfL.

[Characteristics of radiotherapy for adolescents and young adults]

Radiotherapy for adolescents and young adults is complex in several aspects. The population is very heterogeneous and has characteristics derived from both paediatric and adult populations both in terms of pathology (anatomical pathology, response to treatment) and the patient's physical, biological and psychological characteristics. This article reviews the characteristics to be taken into account in adolescent and young adult patients radiotherapy and more particularly in some of the most common diseases.

Incidence, characteristics, management and outcome of patients with follicular lymphoma with tumor epidural compression, a study on 22 cases

PURPOSE

Follicular lymphoma (FL) is one of the most common lymphoma. Occasionally, FL is associated with tumoral epidural compression and management of these patients remain poorly codified. This study aims to report incidence, clinical characteristics, management and outcomes of patients with FL and tumoral epidural compression.

MATERIAL AND METHODS

Observational, retrospective cohort study of adult patients with FL and epidural tumor compression, treated in a French Institute over the last 20 years (2000-2021).

RESULTS

Between 2000 and 2021, 1382 patients with FL were followed by the haematological department. Of them, 22 (1.6%) patients (16 men and 6 women) had follicular lymphoma with epidural tumor compression. At epidural tumor compression occurrence, 8/22 (36%) patients had a neurological clinical deficit (motor, sensory or sphincter function) and 14/22 (64%) had tumor pain. All patients were treated with immuno-chemotherapy; the main regimen being used was R-CHOP plus high dose IV methotrexate in 16/22 (73%) patients. Radiotherapy for tumor epidural compression was performed in 19/22 (86%) patients. With a median follow-up of 60 months (range=[1-216]), 5 year local tumor relapse free survival was achieved in 65% (95% CI 47-90%) of patients. The median PFS was of 36 months (95% CI 24-NA) and 5 years OS estimate was 79% (95% CI 62-100%). Two patients developed a relapse at a second epidural site.

CONCLUSION

FL with tumoral epidural compression reached 1.6% of all FL patients. Management based on immuno-chemotherapy with radiotherapy appeared to produce comparable outcomes with the general FL population.

Quantification of Extramyocellular Lipids and Intramuscular Fat from Muscle Echo Intensity in Lower Limb Muscles: A Comparison of Four Ultrasound Devices against Magnetic Resonance Spectroscopy

This study aimed to compare different ultrasound devices with magnetic resonance spectroscopy (MRS) to quantify muscle lipid content from echo intensity (EI). Four different ultrasound devices were used to measure muscle EI and subcutaneous fat thickness in four lower-limb muscles. Intramuscular fat (IMF), intramyocellular (IMCL) and extramyocellular lipids (EMCL) were measured using MRS. Linear regression was used to compare raw and subcutaneous fat thickness-corrected EI values to IMCL, EMCL and IMF. IMCL had a poor correlation with muscle EI (r = 0.17-0.32, NS), while EMCL (r = 0.41-0.84, p < 0.05-p < 0.001) and IMF (r = 0.49-0.84, p < 0.01-p < 0.001) had moderate to strong correlation with raw EI. All relationships were improved when considering the effect of subcutaneous fat thickness on muscle EI measurements. The slopes of the relationships were similar across devices, but there were some differences in the y-intercepts when raw EI values were used. These differences disappeared when subcutaneous fat thickness-corrected EI values were considered, allowing for the creation of generic prediction equations (r = 0.41-0.68, p < 0.001). These equations can be used to quantify IMF and EMCL within lower limb muscles from corrected-EI values in non-obese subjects, regardless of the ultrasound device used.

Contractile properties are less affected at long than short muscle length after eccentric exercise

PURPOSE

The aim of the present study was to investigate whether the electrically evoked muscle responses are differently affected over time by the knee joint angle after an exercise-induced muscle damage (EIMD). We hypothesized that low-frequency-evoked responses would be less affected at long than short muscle length, and that mechanisms located within the muscle and tendinous tissues would be involved.

METHODS

Fifteen males performed 45 min loaded downhill walking (DW) exercise. Maximal voluntary contraction torque (MVC), optimal angle for torque production, voluntary activation level (VAL), twitch, doublet at 10 and 100 Hz (Db10 and Db100, respectively), rate of torque development (RTD), post-activation potentiation (PAP), muscle shear elastic modulus (µ) and aponeurosis stiffness were assessed before, after, and 4, 24, 48, 72 and 168 h after the exercise at a knee angle of 40°, 90° and 120° (0°: full extension).

RESULTS

MVC, VAL and Db100 were similarly decreased across joint angles after the DW and optimal angle was not affected. Twitch, Db10, Db10/Db100, PAP and RTD were less affected and muscle µ more increased at long than short muscle lengths (p < 0.05), especially during the first 24 h after the DW exercise.

CONCLUSION

Low-frequency-evoked responses were more preserved at long than short muscle length the first 24 h after the DW exercise, suggesting that joint angle should be taken into account to assess muscular alterations after EIMD. This length-dependence could be associated to the higher sensitivity to Ca²⁺ and the higher increase in muscle stiffness at long than short muscle length.

Circulating microRNA levels after exercise-induced muscle damage and the repeated bout effect

The neuromuscular system can quickly adapt to exercise-induced muscle damage (EIMD), such that it is less affected by subsequent damaging exercise, a phenomenon known as the repeated bout effect (RBE). Circulating muscle-specific microRNAs (myomiRs) may be able to potentially predict the long-lasting maximal voluntary contraction (MVC) torque deficit (>24 h), an indicator of EIMD. We aimed to investigate: 1) how plasma myomiR levels are modified by the RBE and 2) whether plasma myomiRs can predict the long-lasting MVC torque deficit. Nineteen participants performed two identical bouts of loaded downhill walking separated by 2 wk. MVC torque, creatine kinase (CK) activity, myoglobin (Mb) concentration, and myomiR levels were measured before and up to 48 h after exercise. Correlation and multiple regression analyses were performed to assess the ability of these markers to predict the largest MVC torque loss beyond 24 h postexercise. Similar to MVC torque, CK activity, and the Mb concentration, the relative abundance of certain myomiRs (hsa-miR-1-3p, and hsa-miR-133a-3p) was less affected after the second bout of exercise relative to the first bout. The CK activity, Mb concentration, and level of several myomiRs (hsa-miR-1-3p, hsa-miR-133a-3p, and hsa-miR-206) correlated with long-lasting MVC torque loss. Multiple regression showed that the best combination of markers to predict the long-lasting deficit of MVC torque included several myomiRs, Mb, and CK. Certain myomiR levels increased less after exercise bout 2 than after exercise bout 1, indicating the presence of the RBE. The measurement of myomiR levels in combination with Mb concentrations and CK activity could improve the prediction of the long-lasting MVC torque deficit.NEW & NOTEWORTHY The present study is the first to show that plasma muscle-specific microRNA (myomiR) levels can be modified by the repeated bout effect, as their levels increased less after the second exercise bout relative to the first. This study is also the first to suggest that myomiR levels could be used to partially predict maximal voluntary contraction torque loss at 24 h postexercise (i.e., the magnitude of exercise-induced muscle damage). Interestingly, the combined measurement of certain myomiR levels with those of myoglobin and creatine kinase improved the predictive value.

Differences in time to task failure and fatigability between children and young adults: A systematic review and meta-analysis

The transition from childhood to adulthood is characterized by many physiological processes impacting exercise performance. Performance fatigability and time to task failure are commonly used to capture exercise performance. This review aimed to determine the differences in fatigability and TTF between youth (including both children and adolescents) and young adults, and to evaluate the influence of exercise modalities (i.e., exercise duration and type of exercise) on these differences. Medline, SPORTDiscus and Cochrane Library were searched. Thirty-four studies were included. The meta-analyses revealed that both children (SMD −1.15; p &lt; 0.001) and adolescents (SMD −1.26; p = 0.022) were less fatigable than adults. Additional analysis revealed that children were less fatigable during dynamic exercises (SMD −1.58; p &lt; 0.001) with no differences during isometric ones (SMD –0.46; p = 0.22). Children (SMD 0.89; p = 0.018) but not adolescents (SMD 0.75; p = 0.090) had longer TTF than adults. Additional analyses revealed 1) that children had longer TTF for isometric (SMD 1.25; p &lt; 0.001) but not dynamic exercises (SMD −0.27; p = 0.83), and 2) that TTF differences between children and adults were larger for short- (SMD 1.46; p = 0.028) than long-duration exercises (SMD 0.20; p = 0.64). Children have higher endurance and are less fatigable than adults. These differences are influenced by the exercise modality, suggesting distinct physiological functioning during exercise between children and adults. The low number of studies comparing these outcomes between adolescents versus children and adults prevents robust conclusions and warrants further investigations in adolescent individuals.

Eptinezumab for migraine prevention in patients 50 years or older

OBJECTIVE

To evaluate the efficacy and safety of eptinezumab versus placebo in patients ≥50 years old with episodic (EM) or chronic migraine (CM).

MATERIALS AND METHODS

This post hoc analysis included data from two phase 3, parallel-group, randomized, double-blind, placebo-controlled studies in adults with EM (PROMISE-1) or CM (PROMISE-2). Patients ≥50 years at baseline treated with eptinezumab 100 mg, 300 mg, or placebo were pooled from both studies to evaluate efficacy and safety.

RESULTS

A total of 385/1960 (19.6%) EM and CM patients who were ≥50 years old at baseline (range, 50-71 and 50-65 years, respectively) received eptinezumab 100 mg (n = 132), 300 mg (n = 127), or placebo (n = 126) over Weeks 1-12. Reductions in mean monthly migraine days (MMDs) in ≥50-year-old EM patients were -3.8 (100 mg) and -4.4 (300 mg) with eptinezumab versus -2.6 with placebo. In ≥50-year-old CM patients, mean changes in MMDs were -7.7 (100 mg) and -8.6 (300 mg) with eptinezumab versus -6.0 with placebo. Changes in MMDs were comparable to total study results. A ≥50% MMD reduction over Weeks 1-12 was achieved by 57.9% of eptinezumab-treated versus 35.7% of patients who received placebo, and a ≥75% reduction by 30.5% versus 13.5%, respectively. The incidence of treatment-emergent adverse events (TEAEs) in EM and CM patients ≥50 years old was similar across treatment groups, with ≥96% of TEAEs mild or moderate in severity.

CONCLUSIONS

Treatment with eptinezumab was efficacious, tolerable, and safe in patients ≥50 years with EM or CM, congruent with results from the overall study population.

Evaluation of Recombinant Botulinum Neurotoxin Type A1 Efficacy in Peripheral Inflammatory Pain in Mice

Well-established efficacy of botulinum neurotoxin type A (BoNT/A) in aesthetic dermatology and neuromuscular hyperactivity disorders relies on canonical interruption of acetylcholine neurotransmission at the neuromuscular junction at the site of the injection. The mechanisms and the site of activity of BoNT/A in pain, on the other hand, remain elusive. Here, we explored analgesic activity of recombinant BoNT/A1 (rBoNT/A1; IPN10260) in a mouse model of inflammatory pain to investigate the potential role of peripheral sensory afferents in this activity. After confirming analgesic efficacy of rBoNT/A1 on CFA-induced mechanical hypersensitivity in C57Bl6J mice, we used GCaMP6s to perform in vivo calcium imaging in the ipsilateral dorsal root ganglion (DRG) neurons in rBoNT/A1 vs. vehicle-treated mice at baseline and following administration of a range of mechanical and thermal stimuli. Additionally, immunohisochemical studies were performed to detect cleaved SNAP25 in the skin, DRGs and the spinal cord. Injection of CFA resulted in reduced mechanical sensitivity threshold and increased calcium fluctuations in the DRG neurons. While rBoNT/A1 reduced mechanical hypersensitivity, calcium fluctuations in the DRG of rBoNT/A1- and vehicle-treated animals were similar. Cleaved SNAP25 was largely absent in the skin and the DRG but present in the lumbar spinal cord of rBoNT/A1-treated animals. Taken together, rBoNT/A1 ameliorates mechanical hypersensitivity related to inflammation, while the signal transmission from the peripheral sensory afferents to the DRG remained unchanged. This strengthens the possibility that spinal, rather than peripheral, mechanisms play a role in the mediation of analgesic efficacy of BoNT/A in inflammatory pain.

Muscle Shear Elastic Modulus Provides an Indication of the Protection Conferred by the Repeated Bout Effect

Background: The neuromuscular system is able to quickly adapt to exercise-induced muscle damage (EIMD), such that it is less affected by subsequent damaging exercise, a phenomenon known as the repeated bout effect (RBE). The objective was to determine whether the mechanical properties of the quadriceps, as evaluated by shear wave elastography (SWE), were less affected when a second bout of eccentric-biased exercise was performed 2 weeks later. It was hypothesized that the first bout would confer protection against extensive muscle damage through an adaptation of the muscle stiffness before the second bout (i.e., higher muscle stiffness).

Methods: Sixteen males performed two identical bouts of downhill walking separated by 2 weeks (45 min at 4.5 km.h−1; gradient: 25%; load: 30% of the body mass). Rectus femoris (RF) and vastus lateralis (VL) resting shear elastic modulus (µ) and EIMD symptoms were measured before and up to 7 days following the exercise bouts. Changes in neuromuscular function was evaluated by maximal voluntary contraction torque, voluntary activation level, evoked mechanical response to single and double (10 and 100 Hz doublets) electrical stimulation. An index of protection (IP) was calculated for EIMD symptoms to assess magnitude the RBE.

Results: EIMD symptoms were less affected after the second than the first exercise bout. RF and VL-µ increased (p &lt; 0.001) only after the first exercise. RF µ was elevated up to 2 weeks after the end of the first exercise (p &lt; 0.001) whereas VL µ was only increased up to 24 h. The increase in µ observed 2 weeks after the end of the first exercise was correlated with the IP; i.e., attenuation of alterations in muscle µ, 10 Hz-doublet amplitude and rate of torque development after the second exercise bout (p &lt; 0.05).

Conclusion: We showed that muscle µ assessed by SWE was sensitive to the RBE, with a differential effect between VL and RF. The persistent increase in µ was associated with the attenuation of neuromuscular impairments observed after the second bout, suggesting that the increased muscle stiffness could be a “protective” adaptation making muscles more resistant to the mechanical strain associated to eccentric contractions.

Determination of exercise intensity domains during upright versus supine cycling: a methodological study

Background

There is a growing interest among the research community and clinical practitioners to investigate cardiopulmonary exercise test (CPET) procedures and protocols utilized in supine cycling.

Materials and Methods

The current study investigated the effects of posture on indicators of exercise intensity including gas exchange threshold (GET), respiratory compensation point (RCP), and the rate of peak oxygen uptake (V̇O₂ peak), as well as the role of V̇O₂ mean response time (MRT) in determining exercise intensity domains in nineteen healthy men (age: 22 ± 3 years). Two moderate-intensity step-transitions from 20 to 100 Watt (W) were completed, followed by a maximal CPET. After completing the ramp test, participants performed a constant-load at 90% of their attained peak power output (PPO).

Results

No differences were observed in the V̇O₂ MRT between the two positions, although the phase II-time constant (τV̇O_2p) was 7 s slower in supine position compared to upright (p = 0.001). The rate of O₂ uptake in the supine position at GET and RCP were lower compared to the upright position (208 ± 200 mL·min^-1 (p = 0.007) and 265 ± 235 mL·min^-1 (p = 0.012) respectively). Besides, V̇O₂ peak was significantly decreased (by 6%, p = 0.002) during supine position. These findings were confirmed by the wide limits of agreement between the measures of V̇O₂ in different postures (V̇O₂ peak: -341 to 859; constant-load test: -528 to 783; GET: -375 to 789; RCP: -520 to 1021 all in mL·min^-1).

Conclusion

Since an accurate identification of an appropriate power output (PO) from a single-visit CPET remains a matter of debate, especially for supine cycling, we propose that moderate-intensity step-transitions preceding a ramp CPET could be a viable addition to ensure appropriate exercise-intensity domain determination, in particular upon GET-based prescription.

Low cost 3D printing of metals using filled polymer pellets

Nowadays, additive manufacturing of metallic materials is most often carried out using expensive and complex tools that leave the user with limited control and no possibility of modification. In order to make the printing of metal parts more accessible to small structures but also better suited for academic research, the use of a mixture of thermoplastic polymer and metal powder is a good solution as many granular feedstocks already exist for Metal Injection Molding applications. To perform the shaping process, the Fused Granular Fabrication 3D printing technology is set up by diverting the use of a feedstock in the form of pellets that are directly inserted into the print head. This solution, which is less costly, is implemented here by modifying a mid-range printer, the Tool Changer from E3D, and by making the hardware and software adaptations to mount a compact granulates extruder on it, which is also available on the market. The polymer portion present in the green part can then be removed in order to perform the heat treatments that will densify the powder by sintering and give a fully metallic dense object.

Alterations of the endocannabinoid system and circulating and peripheral tissue levels of endocannabinoids in sarcopenic rats

BACKGROUND

Activation of the endocannabinoid system (ECS) is associated with the development of obesity and insulin resistance, and with perturbed skeletal muscle development. Age-related sarcopenia is a progressive and generalized skeletal muscle disorder involving an accelerated loss of muscle mass and function, with changes in skeletal muscle protein homeostasis due to lipid accumulation and anabolic resistance. Hence, both obesity and sarcopenia share a common set of pathophysiological alterations leading to skeletal muscle impairment. The aim of this study was to characterize how sarcopenia impacts the ECS and if these modifications were related to the loss of muscle mass and function associated with aging in rats.

METHODS

Six-month-old and 24-month-old male rats were used to measure the contractile properties of the plantarflexors (isometric torque-frequency relationship & concentric power-velocity relationship) and to evaluate locomotor activity, motor coordination, and voluntary gait by open field, rotarod, and catwalk tests, respectively. Levels of endocannabinoids (AEA & 2-AG) and endocannabinoid-like molecules (OEA & PEA) were measured by LCF-MS/MS in plasma, skeletal muscle, and adipose tissue, while the expression of genes coding for the ECS were investigated by quantitative reverse transcription PCR (RT-qPCR).

RESULTS

Sarcopenia in old rats was exemplified by a 49% decrease in hindlimb muscle mass (P < 0.01), which was associated with severe impairment of isometric torque, power, voluntary locomotor activity, motor coordination, and gait quality. Sarcopenia was associated with (1) increased 2-AG (+32%, P = 0.07) and reduced PEA and OEA levels in the plasma (-25% and -40%, respectively, P < 0.01); (2) an increased content of AEA, PEA, and OEA in subcutaneous adipose tissue (P < 0.01); and (3) a four-fold increase of 2-AG content in the soleus (P < 0.01) and a reduced OEA content in EDL (-80%, P < 0.01). These alterations were associated with profound modifications in the expression of the ECS genes in the adipose tissue and skeletal muscle.

CONCLUSIONS

Taken together, these findings demonstrate that circulating and peripheral tissue endocannabinoid tone are altered in sarcopenia. They also demonstrate that OEA plasma levels are associated with skeletal muscle function and loss of locomotor activity in rats, suggesting OEA could be used as a circulating biomarker for sarcopenia.

Deleterious Effect of High-Fat Diet on Skeletal Muscle Performance Is Prevented by High-Protein Intake in Adult Rats but Not in Old Rats

The phenotype of sarcopenic obesity is frequently associated with impaired muscle strength and performance. Ectopic lipid deposition may interfere with muscle anabolic response especially during aging. Evidence is scarce concerning the potential interplay among aging and nutrient imbalance on skeletal muscle functionality. The objective of the present study was to investigate the impact of protein intake in the context of an obesogenic diet on skeletal muscle functional properties and intramuscular lipid infiltration. Two groups of forty-two adult and thirty-seven old male Wistar rats were randomly divided into four groups: isocaloric standard diet (12% protein, 14% lipid, as ST12); isocaloric standard (high-protein) diet (25% protein, 14% lipid, ST25); hypercaloric high-fat (normal-protein) diet (12% protein, 45% lipid, HF12); and hypercaloric high-fat (high-protein) diet (25% protein, 45% lipid, HF25). The nutritional intervention lasted 10 weeks. Total body composition was measured through Echo-MRI. Lipids were extracted from tibialis anterior muscle and analyzed by gas-liquid chromatography. The functional properties of the plantarflexor muscles were evaluated in vivo on an isokinetic dynamometer. Maximal torque was assessed from the torque-frequency relationship in isometric condition and maximal power was evaluated from the torque-velocity relationship in concentric condition. In adult rats high-protein intake combined with high-fat diet determined a lower decrease in relative isometric torque, normalized to either FFM or body weight, compared with adult rats fed a high-fat normal-protein diet. High-fat diet was also detrimental to relative muscle power, as normalized to body weight, that decreased to a larger extent in adult rats fed a high-fat normal-protein diet than their counterparts fed a normal-fat, high-protein diet. The effect of high-fat diet observed in adults, with the enhanced protein intake (25%) conferring some kind of protection against the negative effects of HFD, may be linked to the reduced intramuscular fat in this group, which may have contributed to preserve, at least partly, the contractile properties. A potential role for high-protein diet in preventing ectopic lipid deposition needs to be explored in future research. Detrimental effects of high- fat diet on skeletal muscle performance are mitigated by high- protein intake in adult rats but not in old rats.

Guide for paediatric radiotherapy procedures

A third of children with cancer receive radiotherapy as part of their initial treatment, which represents 800 paediatric irradiations per year in France carried out in 15 specialized centres approved on the recommendations of the French national cancer institute in decreasing order of frequency, the types of cancer that require irradiation are: brain tumours, neuroblastomas, Ewing's sarcomas, Hodgkin's lymphomas, soft tissue sarcomas including rhabdomyosarcomas, and nephroblastomas. The treatment guidelines follow the recommendations of the French society for childhood cancers (SFCE) or the French and European prospective protocols. The therapeutic indications, the technical and/and ballistic choices of complex cases are frequently discussed during bimonthly paediatric radiotherapy technical web-conferences. All cancers combined, overall survival being 80%, long-term toxicity logically becomes an important concern, making the preparation of treatments complex. The irradiation methods include all the techniques currently available: 3D conformational irradiation, intensity modulation radiation therapy, irradiation under normal or hypofractionated stereotaxic conditions, brachytherapy and proton therapy. We present the update of the recommendations of the French society for radiation oncology on the indications, the technical methods of realization and the organisation and the specificities of paediatric radiation oncology.

Sex Differences in Neuromuscular Fatigue and Changes in Cost of Running after Mountain Trail Races of Various Distances

INTRODUCTION

Women have been shown to experience less neuromuscular fatigue than men in knee extensors (KE) and less peripheral fatigue in plantar flexors (PF) after ultratrail running, but it is unknown if these differences exist for shorter trail running races and whether this may impact running economy. The purpose of this study was to characterize sex differences in fatigability over a range of running distances and to examine possible differences in the postrace alteration of the cost of running (Cr).

METHODS

Eighteen pairs of men and women were matched by performance after completing different races ranging from 40 to 171 km, divided into SHORT versus LONG races (<60 and >100 km, respectively). Neuromuscular function and Cr were tested before and after each race. Neuromuscular function was evaluated on both KE and PF with voluntary and evoked contractions using electrical nerve (KE and PF) and transcranial magnetic (KE) stimulation. Oxygen uptake, respiratory exchange ratio, and ventilation were measured on a treadmill and used to calculate Cr.

RESULTS

Compared with men, women displayed a smaller decrease in maximal strength in KE (-36% vs -27%, respectively, P < 0.01), independent of race distance. In SHORT only, women displayed less peripheral fatigue in PF compared with men (Δ peak twitch: -10% vs -24%, respectively, P < 0.05). Cr increased similarly in men and women.

CONCLUSIONS

Women experience less neuromuscular fatigue than men after both "classic" and "extreme" prolonged running exercises but this does not impact the degradation of the energy Cr.

Impact of Concurrent Training on Body Composition and Gut Microbiota in Postmenopausal Women with Overweight or Obesity

PURPOSE

Menopause tends to be associated with an increased risk of obesity and abdominal fat mass (FM) and is associated with lower intestinal species diversity. The aim of this study was to determine the effects of a high-intensity interval training and resistance training (HIIT + RT) program on body composition and intestinal microbiota composition in overweight or obese postmenopausal women.

METHODS

Participants (n = 17) were randomized in two groups: HIIT + RT group (3 × / week, 12 weeks) and control group without any training. Dual-energy X-ray absorptiometry was used to measure whole-body and abdominal/visceral FM and fat-free mass. Intestinal microbiota composition was determined by 16S rRNA gene sequencing at baseline and at the study end, and the diet controlled.

RESULTS

Compared with sedentary controls, physical fitness (Maximal Oxygen Consumption, Peak Power Output) increased, total abdominal and visceral FM decreased, and segmental muscle mass increased in the training group. Although the HIIT + RT protocol did not modify α-diversity and taxonomy, it significantly influenced microbiota composition. Moreover, various intestinal microbiota members were correlated with HIIT + RT-induced body composition changes, and baseline microbiota composition predicted the response to the HIIT + RT program.

CONCLUSIONS

HIIT + RT is an effective modality to reduce abdominal/visceral FM and improve physical capacity in non-dieting overweight or obese postmenopausal women. Training modified intestinal microbiota composition and the response to training seems to depend on the initial microbiota profile. More studies are needed to determine whether microbiota composition could predict the individual training response.

Recombinant botulinum neurotoxin serotype A1 in vivo characterization

Clinically used botulinum neurotoxins (BoNTs) are natural products of Clostridium botulinum. A novel, recombinant BoNT type A1 (rBoNT/A1; IPN10260) has been synthesized using the native amino acid sequence expressed in Escherichia coli and has previously been characterized in vitro and ex vivo. Here, we aimed to characterize rBoNT/A1 in vivo and evaluate its effects on skeletal muscle. The properties of rBoNT/A1 following single, intramuscular administration were evaluated in the mouse and rat digit abduction score (DAS) assays and compared with those of natural BoNT/A1 (nBoNT/A1). rBoNT/A1-injected tibialis anterior was assessed in the in situ muscle force test in rats. rBoNT/A1-injected gastrocnemius lateralis (GL) muscle was assessed in the compound muscle action potential (CMAP) test in rats. The rBoNT/A1-injected GL muscle was evaluated for muscle weight, volume, myofiber composition and immunohistochemical detection of cleaved SNAP25 (c-SNAP25). Results showed that rBoNT/A1 and nBoNT/A1 were equipotent and had similar onset and duration of action in both mouse and rat DAS assays. rBoNT/A1 caused a dose-dependent inhibition of muscle force and a rapid long-lasting reduction in CMAP amplitude that lasted for at least 30 days. Dose-dependent reductions in GL weight and volume and increases in myofiber atrophy were accompanied by immunohistochemical detection of c-SNAP25. Overall, rBoNT/A1 and nBoNT/A1 exhibited similar properties following intramuscular administration. rBoNT/A1 inhibited motoneurons neurotransmitter release, which was robust, long-lasting, and accompanied by cleavage of SNAP25. rBoNT/A1 is a useful tool molecule for comparison with current natural and future modified recombinant neurotoxins products.

P–670 Urine estrone–3-glucuronide (E3G) assay: is there any place during ovarian stimulation for IVF cycles?

Study question

Could the urine estrone–3-glucuronide (E3G) assay be used efficiently to monitor a controlled ovarian hyperstimulation (COH) cycle, in comparison to a serum estradiol (E2) assay?

Summary answer

E3G testing provides an alternative to serum E2 assessment and a new “patient friendly” approach for COH monitoring.

What is known already

In many IVF clinics basic monitoring tools for controlled ovarian stimulation during IVF procedure are ultrasound measurements of follicle growth and hormone assessment of serum E2 levels. The monitoring can occur 4–6 times during stimulation, but repeated blood sampling causes patient stress. In contrast, E3G sampling, one of principal metabolites of estradiol in urine, is non-invasive and can be performed by the patients themselves and measured by fluorescent immunoassay. A correlation has been shown between concentrations of E2 present in plasma and concentrations of E3G in different phases of menstruation cycle.

Study design, size, duration

This is a pilot, prospective study, in a single IVF clinic. Twenty female participants were recruited November 2020 -January 2021, aged 25–43 years and BMI: 18–28kg/m2. Dynamic change of serum E2 and urine E3G at ovarian stimulation monitoring are being analyzed.

Participants/materials, setting, methods

Concurrent urine E3G and serum E2 values were collected from patients who provided between 2 and 4 samples on different days of their COH IVF cycle. Serum E2 values were assessed routinely, while E3G values were measured and validated using a fluorescent immunoassay Mira Fertility Plus® analyzer.Main results and the role of chance: The urine E3G of assay was validated for intra- and inter-assay variability with a coefficient of variation of &lt; 20%. It was also validated for analytical and functional sensitivity and sample stability. Linear regression of serum E2 and E3G values of 56 early morning urine samples who had evaluated between Days 4 and 13 of menstruation cycle provided an R = 0,81. Urine E3G values also correlated to follicle growth. Patient survey results showed that urine sampling was the preferred method of analysis.

Limitations, reasons for caution

We have provided proof of principle that urine E3G measurement can be accurately carried out using fluorescent immunoassay technology during routine COH for IVF cycles. The patients’ study group has to be expanded in order to enable us to find the appropriate place of urine E3G assay in COH protocol.

Wider implications of the findings: Urine E3G testing correlates well to serum E2 assessment in COH. Urine E3G assay provides an alternative to serum-based assessment. The ease of urine sampling allows a reduction in patient discomfort during venopuncture, costs, time, and infection risks in epidemics/pandemics, like COViD–19, and offers a patient-friendly approach to ovarian stimulation.

Trial registration number

NA

Effect of race distance on performance fatigability in male trail and ultra-trail runners

The etiology of changes in lower-limb neuromuscular function, especially to the central nervous system, may be affected by exercise duration. Direct evidence is lacking as few studies have directly compared different race distances. This study aimed to investigate the etiology of deficits in neuromuscular function following short versus long trail-running races. Thirty-two male trail runners completed one of five trail-running races as LONG (>100 km) or SHORT (<60 km). Pre- and post-race, maximal voluntary contraction (MVC) torque and evoked responses to electrical nerve stimulation during MVCs and at rest were used to assess voluntary activation and muscle contractile properties of knee-extensor (KE) and plantar-flexor (PF) muscles. Transcranial magnetic stimulation (TMS) was used to assess evoked responses and corticospinal excitability in maximal and submaximal KE contractions. Race distance correlated with KE MVC (ρ = -0.556) and twitch (ρ = -0.521) torque decreases (p ≤ .003). KE twitch torque decreased more in LONG (-28 ± 14%) than SHORT (-14 ± 10%, p = .005); however, KE MVC time × distance interaction was not significant (p = .073). No differences between LONG and SHORT for PF MVC or twitch torque were observed. Maximal voluntary activation decreased similarly in LONG and SHORT in both muscle groups (p ≥ .637). TMS-elicited silent period decreased in LONG (p = .021) but not SHORT (p = .912). Greater muscle contractile property impairment in longer races, not central perturbations, contributed to the correlation between KE MVC loss and race distance. Conversely, PF fatigability was unaffected by race distance.

Liver resection and ablation for squamous cell carcinoma liver metastases

Background

Limited evidence exists to guide the management of patients with liver metastases from squamous cell carcinoma (SCC). The aim of this retrospective multicentre cohort study was to describe patterns of disease recurrence after liver resection/ablation for SCC liver metastases and factors associated with recurrence-free survival (RFS) and overall survival (OS).

Method

Members of the European–African Hepato-Pancreato-Biliary Association were invited to include all consecutive patients undergoing liver resection/ablation for SCC liver metastases between 2002 and 2019. Patient, tumour and perioperative characteristics were analysed with regard to RFS and OS.

Results

Among the 102 patients included from 24 European centres, 56 patients had anal cancer, and 46 patients had SCC from other origin. RFS in patients with anal cancer and non-anal cancer was 16 and 9 months, respectively (P = 0.134). A positive resection margin significantly influenced RFS for both anal cancer and non-anal cancer liver metastases (hazard ratio 6.82, 95 per cent c.i. 2.40 to 19.35, for the entire cohort). Median survival duration and 5-year OS rate among patients with anal cancer and non-anal cancer were 50 months and 45 per cent and 21 months and 25 per cent, respectively. For the entire cohort, only non-radical resection was associated with worse overall survival (hazard ratio 3.21, 95 per cent c.i. 1.24 to 8.30).

Conclusion

Liver resection/ablation of liver metastases from SCC can result in long-term survival. Survival was superior in treated patients with liver metastases from anal versus non-anal cancer. A negative resection margin is paramount for acceptable outcome.

Fiber Optic Measurements of Soil Moisture in a Waste Rock Pile

The design and construction of a waste rock pile influences water infiltration and may promote the production of contaminated mine drainage. The objective of this project is to evaluate the use of an active fiber optic distributed temperature sensing (aFO-DTS) protocol to measure infiltration and soil moisture within a flow control layer capping an experimental waste rock pile. Five hundred meters of fiber optic cable were installed in a waste rock pile that is 70 m long, 10 m wide, and was covered with 0.60 m of fine compacted sand and 0.25 m of non-reactive crushed waste rock. Volumetric water content was assessed by heating the fiber optic cable with 15-min heat pulses at 15 W/m every 30 min. To test the aFO-DTS system 14 mm of recharge was applied to the top surface of the waste rock pile over 4 h, simulating a major rain event. The average volumetric water content in the FCL increased from 0.10 to 0.24 over the duration of the test. The volumetric water content measured with aFO-DTS in the FCL and waste rock was within ±0.06 and ±0.03, respectively, compared with values measured using 96 dielectric soil moisture probes over the same time period. Additional results illustrate how water can be confined within the FCL and monitored through an aFO-DTS protocol serving as a practical means to measure soil moisture at an industrial capacity.

Circulating microRNAs after a 24-h ultramarathon run in relation to muscle damage markers in elite athletes

Ultra-endurance sports are growing in popularity but can be associated with adverse health effects, such as exercise-induced muscle damage (EIMD), which can lead to exertional rhabdomyolysis. Circulating microRNAs (miRNAs) may be useful to approach the degree of EIMD. We aimed to (1) investigate the relevance of circulating miRNAs as biomarkers of muscle damage and (2) examine the acute response of skeletal/cardiac muscle and kidney biomarkers to a 24-h run in elite athletes. Eleven elite athletes participated in the 24-h run World Championships. Counter-movement jump (CMJ), creatine kinase (CK), myoglobin (Mb), creatinine (Cr), high-sensitive cardiac troponin T (hs-cTnT), and muscle-specific miRNA (myomiR) levels were measured before, immediately after, and 24 and 48h after the race. CMJ height was reduced immediately after the race (-84.0 ± 25.2%, p < 0.001) and remained low at 24 h (-43.6 ± 20.4%, p = 0.002). We observed high CK activity (53 239 ± 63 608 U/L, p < 0.001) immediately after the race, and it remained elevated 24h after (p < 0.01). Circulating myomiR levels (miR-1-3p, miR-133a-3p, miR-133b, miR-208a-3p, miR-208b-3p, and miR-499a-5p) were elevated immediately after the 24-h run (fold changes: 18-124,723, p<0.001) and significantly (p < 0.05) correlated or tended to significantly (p < 0.07) correlate with the reduction in CMJ height at 24 h. We found no significant correlation between CMJ height loss at 24 h and CK (p = 0.23) or Mb (p = 0.41) values. All elite ultramarathon runners included in our study were diagnosed with exertional rhabdomyolysis after the 24-h ultramarathon race. MyomiR levels may be useful to approach the degree of muscle damage.

M-wave and H-reflex recruitment curves in boys and men

The aim of the present study was to check whether the M-wave and H-reflex recruitment curves differ between prepubertal boys and men. Eleven boys (9-11 yr) and eleven men (18-35 yr) were magnetically stimulated at the tibial nerve in a prone position. M-wave and H-reflex maximal amplitudes (H_max; M_max ; H_max /M_max ), thresholds, regression slopes (H_slp ; M_slp ; H_slp /M_slp ) were extracted from M-wave and H-reflex recruitment curves and compared between the two age groups. Overall, no significant difference in M-wave and H-reflex recruitment curve parameters was found between the two populations. Nevertheless, the size of the M-wave associated with maximal H-reflex amplitude was lower in boys as compared to men when expressed relative to maximal M-wave amplitude (M_Hmax /M_max : 0.18 ± 0.06 vs. 0.31 ± 0.13; p < .05). This result suggests that the development of peripheral nerve was completed in 9 to 11-year-old boys and did not affect the M-wave and H-reflex recruitment curves parameters. In neuromuscular function studies, it implies that H_max /M_max and H_slp /M_slp could be used indifferently to compare spinal motoneuron excitability between 9-11-year-old boys and men. Conversely, evoking H-reflexes at a given percentage of M_max may bias the comparison between boys and men.

Greening the synthesis of peptide therapeutics: an industrial perspective

Solid-phase peptide synthesis (SPPS) is generally the method of choice for the chemical synthesis of peptides, allowing routine synthesis of virtually any type of peptide sequence, including complex or cyclic peptide products. Importantly, SPPS can be automated and is scalable, which has led to its widespread adoption in the pharmaceutical industry, and a variety of marketed peptide-based drugs are now manufactured using this approach. However, SPPS-based synthetic strategies suffer from a negative environmental footprint mainly due to extensive solvent use. Moreover, most of the solvents used in peptide chemistry are classified as problematic by environmental agencies around the world and will soon need to be replaced, which in recent years has spurred a movement in academia and industry to make peptide synthesis greener. These efforts have been centred around solvent substitution, recycling and reduction, as well as exploring alternative synthetic methods. In this review, we focus on methods pertaining to solvent substitution and reduction with large-scale industrial production in mind, and further outline emerging technologies for peptide synthesis. Specifically, the technical requirements for large-scale manufacturing of peptide therapeutics are addressed.

Managing the combined consequences of COVID-19 infection and lock-down policies on athletes: narrative review and guidelines proposal for a safe return to sport

COVID-19 pandemic is a global health matter. The disease spread rapidly across the globe and brought the world of sports to an unprecedented stoppage. Usual symptoms of the disease are fever, cough, myalgia, fatigue, slight dyspnoea, sore throat and headache. In more severe cases, dyspnoea, hypoxaemia, respiratory failure, shock and multiorgan failure occur. This appears to be a self-limiting phenomenon related to individuals with coexisting medical conditions, such as hypertension, diabetes and cardiovascular disorders. Nevertheless, cases have been reported in professional soccer players in extremely good fitness condition, demonstrating that athletes are not spared by the disease. Despite COVID-19 clinical manifestations are mainly respiratory, major cardiac complications are being reported, leading to acute myocarditis. One difficulty is that symptoms of COVID-19 vary among individuals, with athletes being affected with no apparent sign of the disease. This could be a real danger for amateur or professional athletes when returning to their usual training and thus to play. Another threat is that the lock-down policies did not allow most athletes to follow their usual training routines. There is thus a need for a careful approach by the sports medicine community to ensure safety of all athletes before they return to sport. Here, we propose evaluation guidelines of fitness and health of athletes to (1) reduce any lethal risk of practice, especially myocarditis and sudden cardiac death; (2) evaluate the combined consequences of the disease and detraining on the physical abilities and biological profile of athletes; and (3) monitor postinfection fatigue symptoms.

Key role of the 5-HT1A receptor addressing protein Yif1B in serotonin neurotransmission and SSRI treatment

BACKGROUND

Altered function of serotonin receptor 1A (5-HT1AR) has been consistently implicated in anxiety, major depressive disorder and resistance to antidepressants. Mechanisms by which the function of 5-HT1AR (expressed as an autoreceptor in serotonergic raphe neurons and as a heteroreceptor in serotonin [5-HT] projection areas) is altered include regulation of its expression, but 5-HT1AR trafficking may also be involved.

METHODS

We investigated the consequences of the lack of Yif1B (the 5-HT1AR trafficking protein) on 5-HT neurotransmission in mice, and whether Yif1B expression might be affected under conditions known to alter 5-HT neurotransmission, such as anxious or depressive states or following treatment with fluoxetine (a selective serotonin reuptake inhibitor) in humans, monkeys and mice.

RESULTS

Compared with wild-type mice, Yif1B-knockout mice showed a significant decrease in the forebrain density of 5-HT projection fibres and a hypofunctionality of 5-HT1A autoreceptors expressed on raphe 5-HT neurons. In addition, social interaction was less in Yif1B-knockout mice, which did not respond to the antidepressant-like effect of acute fluoxetine injection. In wild-type mice, social defeat was associated with downregulated Yif1B mRNA in the prefrontal cortex, and chronic fluoxetine treatment increased Yif1B expression. The expression of Yif1B was also downregulated in the postmortem prefrontal cortex of people with major depressive disorder and upregulated after chronic treatment with a selective serotonin reuptake inhibitor in monkeys.

LIMITATIONS

We found sex differences in Yif1B expression in humans and monkeys, but not in mice under the tested conditions.

CONCLUSION

These data support the concept that Yif1B plays a critical role in 5-HT1AR functioning and brain 5-HT homeostasis. The opposite changes in its expression observed in anxious or depressive states and after therapeutic fluoxetine treatment suggest that Yif1B might be involved in vulnerability to anxiety and depression, and fluoxetine efficacy.

The current state of acute treatment for migraine in adults in the United States

Migraine is a common and disabling disorder with substantial personal, social, and economic burden that affects 37 million people in the United States. Risk factors for migraine include age, sex, and genetics. The goal of acute treatment of migraine attacks is to stop the pain and associated symptoms of the migraine attack and return the patient to normal function. The acute treatment landscape for migraine has recently expanded beyond the standard nonsteroidal anti-inflammatory drugs, analgesics, triptans, ergotamines, and combination therapies, to include neuromodulation devices, and recently approved calcitonin gene-related peptide receptor antagonists and a serotonin (5-HT_1F) receptor agonist. Unmet acute treatment needs still exist due to lack of efficacy, unwanted side effects, or contraindication to treatment. Effective treatment of migraine requires the clinician to assess the patient, make an accurate diagnosis, and then offer appropriate therapy based on the patient's medical history, comorbidities, and preferences, as well as published clinical evidence. The objective of this narrative review is to familiarize primary care clinicians with the variety of acute treatment options available in the United States today based on clinical trial findings, meta-analyses, evidence-based guidelines, and professional society consensus statements.

Efficacy and Safety of Galcanezumab for the Preventive Treatment of Migraine: A Narrative Review

Migraine is a debilitating neurologic disease. People who experience migraine can have substantial disability, impaired functioning and a decreased quality of life (QoL). Expert recommendations suggest that people with frequent migraine attacks or severe impairment related to attacks may benefit from preventive treatment. Despite these recommendations and the existence of evidence-based guidelines for the use of preventive medication, many people who are candidates for preventive therapies do not receive them. Thus, there is still a substantial unmet need for preventive migraine treatment. Calcitonin gene-related peptide (CGRP) has a demonstrated role in the pathophysiology of migraine. Galcanezumab-gnlm (galcanezumab) is a humanized monoclonal antibody that binds to the CGRP ligand and prevents binding to its receptor. It is administered as a once-monthly subcutaneous injection. The aim of this review is to present a comprehensive overview of the existing short- and long-term efficacy and safety data for galcanezumab in patients with migraine. Data from the phase 3, randomized, double-blind, placebo-controlled EVOLVE-1, EVOLVE-2 and REGAIN studies show that galcanezumab treatment for 3 or 6 months results in overall reduction in mean monthly migraine headache days in patients with episodic (EVOLVE-1 and EVOLVE-2) and chronic (REGAIN) migraine. Greater proportions of patients with episodic migraine receiving galcanezumab versus placebo demonstrated a ≥ 50%, ≥ 75% and 100% response to therapy and reported a lower level of disability and an improvement in functioning and QoL. Similarly, when compared with placebo, greater proportions of patients with chronic migraine treated with galcanezumab demonstrated a ≥ 50% and ≥ 75% response and reported improved functioning. A 12-month open-label study demonstrated the continued efficacy of galcanezumab for up to 12 months. In all studies galcanezumab was well tolerated. In conclusion, data from pivotal studies show that galcanezumab may fulfill an unmet need in the treatment of patients with migraine who require preventive therapy.

Migraine is a significant contributor to the global burden of disease. Migraine symptoms can lead to substantial disability and can significantly impact an individual’s ability to perform everyday tasks and their overall quality of life. While individuals with infrequent migraine attacks might have success with acute treatments alone, those with more frequent attacks or who have severe migraine-related impairment may require preventive treatment. Although recommendations on the use of preventive treatment exist, only about one-third of individuals who qualify for preventive therapy actually receive it, resulting in a substantial unmet need. Calcitonin gene-related peptide (CGRP) has a demonstrated role in migraine. Galcanezumab is a humanized monoclonal antibody that binds to the CGRP ligand and prevents receptor binding. In clinical trials of patients with ≥ 4 migraine headache days per month, treatment with galcanezumab was associated with a reduction in the average number of migraine headache days per month. The majority of galcanezumab groups had greater responder rates compared with the placebo groups, and levels of disability and daily functioning were generally improved. Galcanezumab was well tolerated, with the most common adverse events being injection site reactions. The results from the clinical trials of galcanezumab suggest that this drug may fulfill an unmet need in the treatment of individuals with migraine who require preventive therapy.

Effect of Muscle-Tendon Unit Length on Child-Adult Difference in Neuromuscular Fatigue

PURPOSE

The purpose of this study was to compare the development and etiology of neuromuscular fatigue of the knee extensor muscles at different muscle-tendon unit (MTU) lengths during repeated maximal voluntary isometric contractions (MVIC) between boys and men.

METHODS

Twenty-two prepubertal boys (9-11 yr) and 22 men (18-30 yr) performed three knee extensor fatigue protocols at short (SHORT), optimal (OPT), and long (LONG) MTU lengths, consisting of repeating 5-s MVIC interspersed with 5-s passive recovery periods until torque reached 60% of the initial MVIC torque. The etiology of neuromuscular fatigue was identified using noninvasive methods such as surface electromyography, near-infrared spectroscopy, magnetic nerve stimulation and twitch interpolation technique.

RESULTS

The number of repetitions was significantly lower in men at OPT (14.8 ± 3.2) and LONG (15.8 ± 5.8) than boys (39.7 ± 18.4 and 29.5 ± 10.2, respectively; P < 0.001), whereas no difference was found at SHORT between both age groups (boys, 33.7 ± 15.4; men, 40.9 ± 14.2). At OPT and LONG boys showed a lower reduction in the single potentiated twitch (Qtwpot) and a greater decrease in the voluntary activation level than men. At SHORT, both populations displayed a moderate Qtwpot decrement and a significant voluntary activation reduction (P < 0.001). The differences in maximal torque between boys and men were almost twice greater at OPT (223.9 N·m) than at SHORT (123.3 N·m) and LONG (136.5 N·m).

CONCLUSIONS

The differences in neuromuscular fatigue between children and adults are dependent on MTU length. Differences in maximal torque could underpin differences in neuromuscular fatigue between children and adults at OPT and SHORT. However, at LONG these differences do not seem to be explained by differences in maximal torque. The origins of this specific effect of MTU length remain to be determined.