Reference Values, Determinants and Regression Equation for the Timed-Up and Go Test (TUG) in Healthy Asian Population Aged 21 to 85 Years.

The "Timed-Up-and-Go" test (TUG) is a standard assessment tool for functional mobility as it assesses several functional components, including balance, gait, and lower-extremity strength. It has good reliability and validity and is cost-effective and safe, making it an ideal screening tool for falls in various populations, such as older adults or various conditions. However, TUG interpretation relies on comparisons against local normative reference values (NRV), which few studies established for the Asian or younger population. Hence, this study aims to: (1) establish the normative reference values NRV for the population aged 21 to 85 years; (2) determine demographic and anthropometric variables that influence the TUG results; and (3) establish the regression equation of the TUG. A prospective, convenience sampling cross-sectional study recruited subjects aged 21-85 from the community to complete two TUG trials in various parts of Singapore. Variables collected include gender, age, height (meters, m), weight (kilograms, kg), and hand grip strength (HGS) (kg). The intraclass correlation coefficient (ICC) and 95% confidence interval (95% CI) determined test-retest, intra- and inter-rater reliabilities. TUG and variables were analyzed with descriptive statistics and multiple linear regression. p < 0.05 was accepted as statistical significance. Further, 838 subjects (542 females, 296 males) completed the data collection. The mean TUG time was 9.16 s (95% CI 9.01-9.3). Slower TUG was observed with advanced age and female gender. Multiple linear regression analysis demonstrated that age, height, and weight were the best variables to predict TUG scores. The regression formula presented as: TUG (second) = 9.11 + 0.063 (Age, years)-3.19 (Height, meters) + 0.026 (Weight, Kilograms) (R2 = 0.374, p < 0.001). This study provided the TUG NRV and regression formula for healthy Asian adults aged 21 to 85. The information may provide a quick reference for the physical function to interpret assessment findings and guide decision-making in various health and healthcare settings.

Systematic evaluation of CRISPR-Cas systems reveals design principles for genome editing in human cells.

BACKGROUND: While CRISPR-Cas systems hold tremendous potential for engineering the human genome, it is unclear how well each system performs against one another in both non-homologous end joining (NHEJ)-mediated and homology-directed repair (HDR)-mediated genome editing. RESULTS: We systematically compare five different CRISPR-Cas systems in human cells by targeting 90 sites in genes with varying expression levels. For a fair comparison, we select sites that are either perfectly matched or have overlapping seed regions for Cas9 and Cpf1. Besides observing a trade-off between cleavage efficiency and target specificity for these natural endonucleases, we find that the editing activities of the smaller Cas9 enzymes from Staphylococcus aureus (SaCas9) and Neisseria meningitidis (NmCas9) are less affected by gene expression than the other larger Cas proteins. Notably, the Cpf1 nucleases from Acidaminococcus sp. BV3L6 and Lachnospiraceae bacterium ND2006 (AsCpf1 and LbCpf1, respectively) are able to perform precise gene targeting efficiently across multiple genomic loci using single-stranded oligodeoxynucleotide (ssODN) donor templates with homology arms as short as 17 nucleotides. Strikingly, the two Cpf1 nucleases exhibit a preference for ssODNs of the non-target strand sequence, while the popular Cas9 enzyme from Streptococcus pyogenes (SpCas9) exhibits a preference for ssODNs of the target strand sequence instead. Additionally, we find that the HDR efficiencies of Cpf1 and SpCas9 can be further improved by using asymmetric donors with longer arms 5' of the desired DNA changes. CONCLUSIONS: Our work delineates design parameters for each CRISPR-Cas system and will serve as a useful reference for future genome engineering studies.