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bioRxiv2020

Optimizing athlete assessment of maximal force and rate of development A comparison of the isometric squat and mid-thigh pull

This study compared force-time characteristics and muscle activity between the isometric squat (ISQ) and mid-thigh pull (IMTP) in both bilateral (ISQBI and IMTPBI) and unilateral (ISQUNI and IMTPUNI) stance. Peak force (PF), rate-of-force (RFD) (e.g. 0-300ms) and EMG of the multifidus, erector spinae (ES), gluteus maximus (GM), biceps femoris (BF), semitendinosus (ST), vastus medialis (VM), vastus lateralis (VL) and soleus were recorded in ten recreationally trained males. PF was significantly greater during the ISQBI vs. IMTPBI (p=0.016, ES=1.08) but not in the unilateral test mode although effects remained moderate (ES=0.62). A trend indicated heightened RFD300ms (p = 0.083; ES=0.81) during the IMTPBI vs. the ISQBI, but these effects were smaller in the unilateral test (ES = 0.51). Greater (p<0.0001) EMG for VL (ES=1.00-1.13) and VM were recorded during the ISQ compared to IMTP modes in both modes (ES = 0.97 - 1.18). Greater BF EMG (p = 0.030, ES = 0.31) was shown in IMTPBI vs. ISQBI and these effects were stronger in the unilateral modes (p = < 0.05; ES = 0.81 - 0.83). Significantly greater ST activation was shown in both IMTPUNI (p < 0.05; ES = 0.69-0.76) and IMTPBI (p < 0.001; ES = 1.08). These findings indicate that ISQ results in elevated PF, whereas, RFD is heightened during the IMTP and these differences are more pronounced in bilateral modes. Greater activation of the quadriceps and hamstring muscles are expected in ISQ and IMPT respectively.

physiology↗

bioRxiv2019

Deaminase associated single nucleotide variants in blood and saliva-derived exomes from healthy subjects

BackgroundDeaminases play an important role in shaping inherited and somatic variants. Disease related SNVs are associated with deaminase mutagenesis and genome instability. Here, we investigate the reproducibility and variance of whole exome SNV calls in blood and saliva of healthy subjects and analyze variants associated with AID, ADAR, APOBEC3G and APOBEC3B deaminase sequence motifs.\n\nMethodsSamples from twenty-four healthy Caucasian volunteers, allocated into two groups, underwent whole exome sequencing. Group 1 (n=12) analysis involved one blood and four saliva replicates. A single saliva sample was sequenced for Group 2 subjects (n=12). Overall, a total of 72 whole exome datasets were analyzed. Biological (Group 1 & 2) and technical (Group 1) variance of SNV calls and deaminase metrics were calculated and analyzed using intraclass correlation coefficients. Candidate somatic SNVs were identified and evaluated.\n\nResultsWe report high blood-saliva concordance in germline SNVs from whole exome sequencing. Concordant SNVs, found in all subject replicates, accounted for 97% of SNVs located within the protein coding sequence of genes. Discordant SNVs have a 30% overlap with variants that fail gnomAD quality filters and are less likely to be found in dbSNP. SNV calls and deaminase-associated metrics were found to be reproducible and robust (intraclass correlation coefficients >0.95). No somatic SNVs were conclusively identified when comparing blood and saliva samples.\n\nConclusionsSaliva and blood both provide high quality sources of DNA for whole exome sequencing, with no difference in ability to resolve SNVs and deaminase-associated metrics. We did not identify somatic SNVs when comparing blood and saliva of healthy individuals, and we conclude that more specialized investigative methods are required to comprehensively assess the impact of deaminase activity on genome stability in healthy individuals.

genomics↗