Search results for "Tissue"
showing 10 items of 4413 documents
Master runners dominate 24-h ultramarathons worldwide—a retrospective data analysis from 1998 to 2011
2013
Abstract Background The aims of the present study were to examine (a) participation and performance trends and (b) the age of peak running performance in master athletes competing in 24-h ultra-marathons held worldwide between 1998 and 2011. Methods Changes in both running speed and the age of peak running speed in 24-h master ultra-marathoners (39,664 finishers, including 8,013 women and 31,651 men) were analyzed. Results The number of 24-h ultra-marathoners increased for both women and men across years (P < 0.01). The age of the annual fastest woman decreased from 48 years in 1998 to 35 years in 2011. The age of peaking running speed remained unchanged across time at 42.5 ± 5.2 years f…
Age-related changes in ultra-triathlon performances
2012
International audience; BackgroundThe age-related decline in performance has been investigated in swimmers, runners and triathletes. No study has investigated the age-related performance decline in ultra-triathletes. The purpose of this study was to analyse the age-related declines in swimming, cycling, running and overall race time for both Triple Iron ultra-triathlon (11.4-km swimming, 540-km cycling and 126.6-km running) and Deca Iron ultra-triathlon (38-km swimming, 1,800-km cycling and 420-km running).MethodsThe age and performances of 423 male Triple Iron ultra-triathletes and 119 male Deca Iron ultra-triathletes were analysed from 1992 to 2010 using regression analyses and ANOVA.Resu…
Analysis of swimming performance in FINA World Cup long-distance open water races
2014
International audience; BACKGROUND: Age and peak performance in ultra-endurance athletes have been mainly investigated in long-distance runners and triathletes, but not for long-distance swimmers. The present study investigated the age and swimming performance of elite ultra-distance swimmers competing in the 5-, 10- and 25-km Fédération Internationale de Natation (FINA) World Cup swimming events. METHODS: The associations of age and swimming speed in elite male and female swimmers competing in World Cup events of 5-, 10- and 25-km events from 2000 to 2012 were analysed using single and multi-level regression analyses. RESULTS: During the studied period, the swimming speed of the annual top…
Changes in transition times in ‘Ironman Hawaii’ between 1998 and 2013
2014
International audience; BackgroundRecent findings showed that elite Ironman triathletes competing in ‘Ironman Hawaii’ improved both split and overall race times. The present study investigated whether elite athletes also improved in transition time (i.e. time needed between disciplines for changing clothes and equipment).MethodsChanges in split times, overall race times and transition times (i.e. expressed in absolute and relative terms) in the annual fastest competing in ‘Ironman Hawaii’ were investigated using linear, non-linear and multi-level regression analyses. To detect a potential difference in transition times between different race distances, we compared transition times in ‘Ironm…
Nicotinamide riboside improves muscle mitochondrial biogenesis, satellite cell differentiation, and gut microbiota in a twin study
2023
Nicotinamide adenine dinucleotide (NAD + ) precursor nicotinamide riboside (NR) has emerged as a promising compound to improve obesity-associated mitochondrial dysfunction and metabolic syndrome in mice. However, most short-term clinical trials conducted so far have not reported positive outcomes. Therefore, we aimed to determine whether long-term NR supplementation boosts mitochondrial biogenesis and metabolic health in humans. Twenty body mass index (BMI)–discordant monozygotic twin pairs were supplemented with an escalating dose of NR (250 to 1000 mg/day) for 5 months. NR improved systemic NAD + metabolism, muscle mitochondrial number, myoblast differentiation, and gut microbiota compos…
Increased physical activity decreases hepatic free fatty acid uptake: a study in human monozygotic twins
2006
Exercise is considered to be beneficial for free fatty acid (FFA) metabolism, although reports of the effects of increased physical activity on FFA uptake and oxidation in different tissues in vivo in humans have been inconsistent. To investigate the heredity-independent effects of physical activity and fitness on FFA uptake in skeletal muscle, the myocardium, and liver we used positron emission tomography (PET) in nine healthy young male monozygotic twin pairs discordant for physical activity and fitness. The cotwins with higher physical activity constituting the more active group had a similar body mass index but less body fat and 18 +/- 10% higher (P < 0.001) compared to the less active …
COVID-19 and molecular mimicry: The Columbus’ egg?
2020
Highlights • Recently, this Journal published a report about Guillain-Barré syndrome associated with COVID-19 infection. • Guillain-Barré syndrome can be due to molecular mimicry phenomena. • Molecular mimicry had already been described in another SARS. • It could explain the autoimmune signs and symptoms that some patients affected by SARS-CoV-2 can experience.
Kawasaki disease epidemic: pitfalls
2020
AbstractRecent reports have described in the pediatric population a new type of hyperinflammatory response manifested following contact with SARS-CoV-2, with some of the clinical features attributable to Kawasaki disease (KD). The purpose of this commentary is to remark on a possible recent association between SARS-CoV-2 and KD. Although today little is known about the etiology of KD, the most accepted hypothesis is that of a probable viral etiology, therefore, even the SARS-CoV-2 virus could trigger, in genetically predisposed subjects, an exaggerated inflammatory response that is clinically evident like the one described in KD.
Spray dried hyaluronic acid microparticles for adhesion controlled aggregation and potential stimulation of stem cells
2017
Spray-dried microparticles of a derivative of hyaluronic acid (HA) have been engineered to obtain a controlled aggregation with Human Mesenchymal Stem Cells (hMSCs) into 3D constructs. We demonstrated the utility of chemical functionalization of a native constituent of the extracellular matrix to improve processing performances and to control on stem cell adhesion and differentiation. Native hyaluronic acid (HA), cell adhesive peptides (RGD), transforming growth factor β3, dexamethasone are biological agents potentially suitable for chondrogenic stimulation of hMSCS. However unmodified HA suffers of drawbacks in terms of stability and versatility of processing. Functionalization strategies…
Double Flow Bioreactor for In Vitro Test of Drug Delivery.
2015
In this work, double-structured polymeric scaffolds were produced, and a double flow bioreactor was designed and set up in order to create a novel system to carry out advanced in vitro drug delivery tests. The scaffolds, consisting of a cylindrical porous matrix, are able to host cells, thus mimicking a three-dimensional tumor mass: moreover, a âpseudo-vascularâ structure was embedded into the matrix, with the aim of allowing a flow circulation. The structure that emulates a blood vessel is a porous tubular-shaped scaffold prepared by Diffusion Induced Phase Separation (DIPS), with an internal lumen of 2 mm and a wall thickness of 200 micrometers. The as-prepared vessel was incorporated…