Genetic variation and exercise-induced muscle damage: implications for athletic performance, injury and ageing.

Prolonged unaccustomed exercise involving muscle lengthening (eccentric) actions can result in ultrastructural muscle disruption, impaired excitation-contraction coupling, inflammation and muscle protein degradation. This process is associated with delayed onset muscle soreness and is referred to as exercise-induced muscle damage. Although a certain amount of muscle damage may be necessary for adaptation to occur, excessive damage or inadequate recovery from exercise-induced muscle damage can increase injury risk, particularly in older individuals, who experience more damage and require longer to recover from muscle damaging exercise than younger adults. Furthermore, it is apparent that inter-individual variation exists in the response to exercise-induced muscle damage, and there is evidence that genetic variability may play a key role. Although this area of research is in its infancy, certain gene variations, or polymorphisms have been associated with exercise-induced muscle damage (i.e. individuals with certain genotypes experience greater muscle damage, and require longer recovery, following strenuous exercise). These polymorphisms include ACTN3 (R577X, rs1815739), TNF (-308 G>A, rs1800629), IL6 (-174 G>C, rs1800795), and IGF2 (ApaI, 17200 G>A, rs680). Knowing how someone is likely to respond to a particular type of exercise could help coaches/practitioners individualise the exercise training of their athletes/patients, thus maximising recovery and adaptation, while reducing overload-associated injury risk. The purpose of this review is to provide a critical analysis of the literature concerning gene polymorphisms associated with exercise-induced muscle damage, both in young and older individuals, and to highlight the potential mechanisms underpinning these associations, thus providing a better understanding of exercise-induced muscle damage

Socio-emotional behaviour following acquired brain injury

Introduction: Socio-emotional behaviour difficulties following acquired brain injury (ABI) have been shown to have a persisting negative effect on quality of life. A systematic review was carried out to look at the efficacy and clinical effectiveness of available psychological treatments for socio-emotional behaviour difficulties following ABI. Research was carried out to further understand socio-emotional behaviour by exploring the possible underlying cognitive aspects (specifically social cognition) in a traumatic brain injury (TBI) population. The study investigated the relationship between social cognition and socio-emotional behaviour post-TBI. Method: A systematic search of articles published between January 2008 and November 2013 was carried out following the Cochrane (2008) guidelines. Papers were quality assessed to identify strengths and weaknesses. In the research study, forty TBI participants were asked to complete tasks of emotion recognition, theory of mind, cognitive flexibility, processing speed, attention and working memory. Selfrated and proxy-rated behaviour questionnaires were also administered. Results: The systematic review revealed seven studies for inclusion; three papers looked at a Comprehensive Holistic Approach, two papers on Cognitive Behavioural Therapy, and two on Cognitive Rehabilitation Therapy. The findings suggested that CHA showed the best efficacy and generalization. However, there were also positive results within the CBT studies. The research paper found that the TBI group performed significantly poorer than the control group on measures of emotion recognition and three out of the four ToM tasks. The TBI group also performed significantly poorer on measures of processing speed and working memory (executive function). There was no association found between performance on any of the cognitive tests and socio-emotional behaviour. Conclusions: This is an area of limited research, likely due to the challenges of carrying out research in an ABI population. The systematic review highlighted the limited research available which has implications in clinical practice due to a lack of evidence base for potentially effective interventions. The research study results suggest that there is still a lack of understanding of socio-emotional behaviour and its underlying cognitive functioning. Further research would improve understanding and could also focus appropriate post-ABI interventions for socio-emotional behaviour problems

Comparison of the recurrence rate of gastric dilatation with or without volvulus in dogs after circumcostal gastropexy versus gastrocolopexy

Objective - To compare the recurrence rate of acute gastric dilatation with or without volvulus (GDV) after circumcostal gastropexy (CCGP) or gastrocolopexy (GCP) in dogs. Study Design - A prospective, double-blind, multicenter, randomized, controlled, clinical trial with two groups (A and B). Animals - Fifty-four client-owned dogs presented for treatment of GDV. Methods - Dogs with acute GDV that had not previously had a gastropexy performed were included. The preoperative treatment before gastropexy was standardized. A CCGP was performed on dogs in group A, and a GCP was performed on dogs in group B. Postoperative treatment was standardized, but deviation did occur according to the special needs of particular patients. A minimal follow-up time of 180 days was required for dogs not excluded from the study. The median follow-up time in group A was 700 days; in group B, it was 400 days. The occurrence of abdominal pain and gastrointestinal problems after surgery were recorded by the owners. Results - There was no significant difference in the recurrence rate of GDV between the two groups. At the end of the study, the recurrence rate was 9% and 20% in group A and in group B, respectively. Conclusions - Both surgical techniques are effective in preventing recurrence of GDV.</p

Design of coiled-coil protein-origami cages that self-assemble in vitro and in vivo

Polypeptides and polynucleotides are natural programmable biopolymers that can self-assemble into complex tertiary structures. We describe a system analogous to designed DNA nanostructures in which protein coiled-coil (CC) dimers serve as building blocks for modular de novo design of polyhedral protein cages that efficiently self-assemble in vitro and in vivo. We produced and characterized gt 20 single-chain protein cages in three shapes-tetrahedron, four-sided pyramid, and triangular prism-with the largest containing gt 700 amino-acid residues and measuring 11 nm in diameter. Their stability and folding kinetics were similar to those of natural proteins. Solution small-angle X-ray scattering (SAXS), electron microscopy (EM), and biophysical analysis confirmed agreement of the expressed structures with the designs. We also demonstrated self-assembly of a tetrahedral structure in bacteria, mammalian cells, and mice without evidence of inflammation. A semi-automated computational design platform and a toolbox of CC building modules are provided to enable the design of protein cages in any polyhedral shape.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3212