BACKGROUND: Physical inactivity impairs insulin sensitivity, which is exacerbated with aging. We examined the impact of 2 wk of acute inactivity and recovery on glycemic control, and integrated rates of muscle protein synthesis in older men and women.
METHODS: Twenty-two overweight, prediabetic older adults (12 men, 10 women, 69 ± 4 y) undertook 7 d of habitual activity (baseline; BL), step reduction (SR; <1,000 steps.d-1 for 14 d), followed by 14 d of recovery (RC). An oral glucose tolerance test was used to assess glycemic control and deuterated water ingestion to measure integrated rates of muscle protein synthesis.
RESULTS: Daily step count was reduced (all p < .05) from BL at SR (7362 ± 3294 to 991 ± 97) and returned to BL levels at RC (7117 ± 3819). Homeostasis model assessment-insulin resistance increased from BL to SR and Matsuda insulin sensitivity index decreased and did not return to BL in RC. Glucose and insulin area under the curve were elevated from BL to SR and did not recover in RC. Integrated muscle protein synthesis was reduced during SR and did not return to BL in RC.
CONCLUSIONS: Our findings demonstrate that 2 wk of SR leads to lowered rates of muscle protein synthesis and a worsening of glycemic control that unlike younger adults is not recovered during return to normal activity in overweight, prediabetic elderly humans.
- Alcock, B., A.R. Raphenya, A.N. Sharma, K.K. Tsang, T.T.Y. Lau, A. Hernandez-Koutoucheva, & A.G. McArthur. 2018. Data and curation in the Comprehensive Antibiotic Resistance Database. Poster presentation at the Canadian Society of Microbiologists Annual Meeting, Winnipeg, Manitoba.
- Lau, T.T.Y., A.R. Raphenya, B. Alcock, & A.G. McArthur. 2018. Optimizing antimicrobial resistance surveillance tools through biological data organization and taxonomic identification of resistance genes. Poster presentation at the Canadian Society of Microbiologists Annual Meeting, Winnipeg, Manitoba.
- Maguire, F., A.R. Raphenya, B. Alcock, A.G. McArthur, F.S. Brinkman, & R.G. Beiko. 2018. The cost of speed: evaluating systematic failures in metagenomic AMR profiling. Poster presentation at the Canadian Society of Microbiologists Annual Meeting, Winnipeg, Manitoba.
- Raphenya, A.R., B. Alcock, K.K. Tsang, A.N. Sharma, T.T.Y. Lau, A. Hernandez-Koutoucheva, & A.G. McArthur. 2018. The Comprehensive Antibiotic Resistance Database and the Resistance Gene Identifier – Prediction of antimicrobial resistance genes and mutations for genomic and metagenomic sequencing data. Oral presentation at the Canadian Society of Microbiologists Annual Meeting, Winnipeg, Manitoba.
- Tsang, K.K., H. Zubyk, S. Chou, G.D. Wright, & A.G. McArthur. Decoding bad bags: Predicting antibiotic resistance phenotypes from genotype. Oral presentation at the Canadian Society of Microbiologists Annual Meeting, Winnipeg, Manitoba.
Kara Tsang passed her graduate transfer exam today, officially moving from the McMaster Biochemistry & Biomedical Sciences Masters program to the Ph.D. program. Kara’s work focusses on the intersection of biocuration, bioinformatics, machine learning, mutant screening, and phenotypic testing for prediction antimicrobial resistance phenotype from genotype. Well done Kara!
Update: Hot on the heels of becoming a Ph.D. student, Kara has won a 2018/2019 Department of Biochemistry & Biomedical Sciences’s Fred and Helen Knight Enrichment Award!
Round whitefish (Prosopium cylindraceum) have a broad, disjunct range across northern North America and Eurasia, and little is known about their genetic population structure. We performed genetic analyses of round whitefish from 17 sites across its range using nine microsatellites, two mitochondrial DNA (mtDNA) loci, and 4918 to 8835 single-nucleotide polymorphism (SNP) loci. Our analyses identified deep phylogenetic division between eastern and western portions of the range, likely indicative of origins from at least two separate Pleistocene glacial refugia. Regionally, microsatellites and SNPs identified congruent patterns in subdivision, and population structure was consistent with expectations based on hydrologic connectivity. Within the Laurentian Great Lakes, Lake Huron and Lake Ontario were identified as key areas of interest. Lake Huron appears to be a contemporary source population for several other Great Lakes, and Lake Ontario contains a genetically discrete group of round whitefish. In all cases, multiple genetic markers yielded similar patterns, but SNPs offered substantially enhanced resolution. We conclude that round whitefish have population subdivision on several scales important for understanding their evolutionary history and conservation planning.
Tammy Lau has been awarded a prestigious Michael G. DeGroote Institute for Infectious Disease Research (IIDR) Summer Student Fellowship for her work on development of k-mer approaches to predicting pathogen-of-origin for metagenomics antimicrobial resistance gene sequences. More details here.
The McArthur lab welcomes Pardeep Gill, who will be performing a Biochem 3R06 project on the phylogenetic origins of AraC and NeuB proteins in collaboration with the Knodler lab at Washington State University and the Berti lab of McMaster’s Chemistry & Chemical Biology department, respectively.
Tammy Lau is continuing her k-mer algorithm development for AMR gene pathogen-of-origin prediction thesis work as a summer student (as part of the IRIDA consortium) and Bhavya Singh and Alexandra Florescu will be volunteering part-time on ontology development (as part of the GenEpiO consortium).
Dr. McArthur has been busy doing some Government outreach. In early 2018 he was a Panellist on Artificial Intelligence in Healthcare at Norwegian Health Ministry & Government of Canada Round Table hosted by Hamilton Health Sciences and then in May 2018 represented McMaster University at Research Canada’s Health Research Caucus – Reshaping Health Research and Innovation: Artificial Intelligence and Machine Learning at Parliament Hill, Ottawa.
The Comprehensive Antibiotic Resistance Database has been updated, http://card.mcmaster.ca
CARD Curation: Addition of HERA, TRU, & ACI beta-lactamases, sul4, and new quinolone efflux pumps.
Antibiotic Resistance Ontology: Expanded to include an entirely new branch describing AMR phenotypic testing methods. ARO additionally now officially available at the OBO Foundry, allowing formal integration with other ontological resources, most notably the Genomic Epidemiology Application Ontology (GenEpiO), https://github.com/genepio/genepio.
Resistance Gene Identifier: Resistome prediction for low quality or low coverage assemblies, merged metagenomics reads, and small plasmids or assembly contigs. Includes prediction of partial AMR genes. Support added for Docker operating-system-level virtualization (i.e. containerization).
Prevalence, Resistomes, & Variants: Expanded to 67 important pathogens, with a focus on ESKAPEs, WHO Priority Pathogens, and agents of sepsis.