Fundamentals of glycogen metabolism for coaches and athletes

The ability of athletes to train day after day depends in large part on adequate restoration of muscle glycogen stores, a process that requires the consumption of sufficient dietary carbohydrates and ample time. Providing effective guidance to athletes and others wishing to enhance training adaptations and improve performance requires an understanding of the normal variations in muscle glycogen content in response to training and diet; the time required for adequate restoration of glycogen stores; the influence of the amount, type, and timing of carbohydrate intake on glycogen resynthesis; and the impact of other nutrients on glycogenesis. This review highlights the practical implications of the latest research related to glycogen metabolism in physically active individuals to help sports dietitians, coaches, personal trainers, and other sports health professionals gain a fundamental understanding of glycogen metabolism, as well as related practical applications for enhancing training adaptations and preparing for competition.

Three dimensional rotational angiography imaging of double aortic arch vascular ring

BACKGROUND

Three dimensional (3D) rotational angiography is a technique used increasingly for imaging in congenital heart disease.

RESULTS

We describe the use of this technique for imaging of double aortic arch vascular ring and discuss the advantages of this modality.

CONCLUSIONS

3D rotational angiography is an excellent tool for imaging of various vascular anomalies. It provides high quality accurate images through a quick and safe procedure.

What Can We Learn About Diet and Physical Activity From Master Athletes?

Only 13% of those 65 years and older engage in vigorous physical activity 3 or more days a week and obesity rates are increasing by 45% in adults over the age of 60. Physical activity helps prevent chronic disease and improves quality of life, yet few adults of any age are active. One exception is master athletes who participate in competitive sports during the middle and later years. The aerobic fitness of master athletes, as measured by maximal oxygen consumption, shows some decline, but not nearly as much as in sedentary controls. Master athletes have lipid profiles similar to those of young adults, which decreases their risk of heart disease. Master athletes also have better glucose tolerance and lower waist-to-hip ratios than sedentary adults, decreasing their risk for metabolic syndrome and type 2 diabetes. In the few dietary studies that have been conducted, master athletes consume more food energy while maintaining lower body weights than sedentary adults. Learning what motivates master athletes to stay highly active may help health professionals develop strategies to encourage exercise in the sedentary population of older adults.

Additional mutations in argininosuccinate synthetase causing citrullinemia

Deficiency of argininosuccinate synthetase causes arginine auxotrophy in lower organisms and causes citrullinemia in humans and cattle. Previously, seven missense mutations, four mutations associated with an absence of an exon in mRNA, and one splicing mutation have been identified in human neonatal citrullinemia. Reverse transcription of mRNA, amplification of cDNA and sequencing of cDNA clones were used to identify two additional missense mutations causing citrullinemia. One mutation involves substitution of leucine for serine at position 18 (S18L) and the other a substitution of cysteine for arginine at position 86 (R86C). Both of these mutations represent C----T transitions in CpG dinucleotides, and eight of nine missense mutations causing human citrullinemia involve similar transitions in CpG dinucleotides. The nucleotide coding sequence and deduced amino acid analysis are available for four mammalian species, yeast and three bacterial species. Six of nine missense mutations in humans occur in amino acid positions that are completely conserved in these organisms. Mutations causing human citrullinemia are extremely heterogeneous, and all non-consanguineous individuals studied to date are compound heterozygotes.

Additional polymorphism for D7S8 linked to cystic fibrosis including detection by DNA amplification

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