Sports Science and Efforts towards Sub-Two Hour Marathon Performance

Performance in different athletic activities has continued to improve over time, with some athletes from diverse parts of the world registering new world records from time to time. With stiff competition from athletes from different parts of the world, constant upgrading of sports science based approaches to training and competition are employed to achieve more success. However, some approaches used to improve sports performance may pose ethical concerns and may challenge sports as a concept of celebrating natural human abilities. This book chapter interrogates the factors associated with efforts towards improvement of performance in endurance sports events, with a specific focus on marathon races, and the future implications for training, competition, and the nature of sports. While the interplay between nature and nurture determines the unique psychophysiological responses to training and competition, technological exploits leading to advanced sports products coupled with favourable natural and/or manipulated internal (body) and external environmental conditions will ensure continued improvement in performance. However, there is a need to censor commercial interest as well as safeguard safety and the nature of sports as a medium to celebrate natural human abilities

Exome sequencing of senescence-accelerated mice (SAM) reveals deleterious mutations in degenerative disease-causing genes

Background: Senescence-accelerated mice (SAM) are a series of mouse strains originally derived from unexpected crosses between AKR/J and unknown mice, from which phenotypically distinct senescence-prone (SAMP) and -resistant (SAMR) inbred strains were subsequently established. Although SAMP strains have been widely used for aging research focusing on their short life spans and various age-related phenotypes, such as immune dysfunction, osteoporosis, and brain atrophy, the responsible gene mutations have not yet been fully elucidated. Results: To identify mutations specific to SAMP strains, we performed whole exome sequencing of 6 SAMP and 3 SAMR strains. This analysis revealed 32,019 to 38,925 single-nucleotide variants in the coding region of each SAM strain. We detected Ogg1 p.R304W and Mbd4 p.D129N deleterious mutations in all 6 of the SAMP strains but not in the SAMR or AKR/J strains. Moreover, we extracted 31 SAMP-specific novel deleterious mutations. In all SAMP strains except SAMP8, we detected a p.R473W missense mutation in the Ldb3 gene, which has been associated with myofibrillar myopathy. In 3 SAMP strains (SAMP3, SAMP10, and SAMP11), we identified a p.R167C missense mutation in the Prx gene, in which mutations causing hereditary motor and sensory neuropathy (Dejerine-Sottas syndrome) have been identified. In SAMP6 we detected a p.S540fs frame-shift mutation in the Il4ra gene, a mutation potentially causative of ulcerative colitis and osteoporosis. Conclusions: Our data indicate that different combinations of mutations in disease-causing genes may be responsible for the various phenotypes of SAMP strains.ArticleBMC GENOMICS. 14:248 (2013)journal articl

Severe Aortic Stenosis in Dialysis Patients

Background: Characteristics and prognosis of hemodialysis patients with severe aortic stenosis have not yet been well defined. Methods and Results: The CURRENT AS (contemporary outcomes after surgery and medical treatment in patients with severe aortic stenosis) registry, a Japanese multicenter registry, enrolled 3815 consecutive patients with severe aortic stenosis. There were 405 hemodialysis patients (initial aortic valve replacement [AVR] group: N=135 [33.3%], and conservative group: N=270) and 3410 nonhemodialysis patients (initial AVR group: N=1062 [31.1%], and conservative group: N=2348). The median follow‐up duration after the index echocardiography was 1361 days, with 90% follow‐up rate at 2 years. The cumulative 5‐year incidence of all‐cause death was significantly higher in hemodialysis patients than in nonhemodialysis patients in both the entire cohort (71% versus 40%, P<0.001) and in the initial AVR group (63.2% versus 17.9%, P<0.001). Among hemodialysis patients, the initial AVR group as compared with the conservative group was associated with significantly lower cumulative 5‐year incidences of all‐cause death (60.6% versus 75.5%, P<0.001) and sudden death (10.2% versus 31.7%, P<0.001). Nevertheless, the rate of aortic valve procedure–related death, which predominantly occurred within 6 months of the AVR procedure, was markedly higher in the hemodialysis patients than in the nonhemodialysis patients (21.2% and 2.3%, P<0.001). Conclusions: Among hemodialysis patients with severe aortic stenosis, the initial AVR strategy as compared with the conservative strategy was associated with significantly lower long‐term mortality risk, particularly the risk for sudden death, although the effect size for the survival benefit of the initial AVR strategy was smaller than that in the nonhemodialysis patients