Protein:DNA interactions at yeast replication origins in vivo

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Associations between duration and volume of muscle-strengthening exercise and clinically assessed hypertension among 10 519 UK adults: a cross-sectional study

BACKGROUND: Clinical evidence shows that muscle-strengthening exercise (MSE) is important for the treatment and management of hypertension. However, the links between MSE and hypertension in epidemiological research are currently poorly understood. This study examines the association between MSE duration and volume with clinically assessed hypertension. METHODS: Cross-sectional data (n = 10519, adults ≥ 16 years) were pooled from the Health Survey for England (2012, 2016). Self-reported MSE mode (own bodyweight; gym-based), duration, and volume were tested for associations with sphygmomanometer measured hypertension (SBP ≥ 130 mmHg or DBP ≥ 80 mmHg). Poisson regressions with robust error variance were used to calculate the prevalence ratios of hypertension (outcome variable) across MSE (exposure variables: duration (minutes [0 (reference); 10-20; 21 -59; ≥60/session]); and volume [0 (reference); low <mean; high ≥mean/week]) for each mode and the modes combined. RESULTS: Most adults (81.1%) did no MSE. However, in those who did (n = 1984), undertaking any MSE, regardless of mode, duration, or volume, was associated with a reduced likelihood of hypertension (adjusted prevalence ratios 0.61-0.90). When compared with the reference groups (no MSE), some modes had more favourable associations (e.g. ≥60 min/session of own bodyweight MSE; ≥mean min/week of gym-based MSE). CONCLUSION: Irrespective of duration or volume, MSE was associated with a lower prevalence of clinically assessed hypertension. Public-health campaigns and other interventions that successfully promote small-to-moderate increases in MSE participation may reduce the prevalence of hypertension

Associations between muscle-strengthening exercise and prevalent chronic health conditions in 16,301 adults: Do session duration and weekly volume matter?

Objectives: Muscle-strengthening exercise (MSE) has multiple health benefits and is part of the global physical activity guidelines. However, with epidemiological research largely focussing on participation frequency (times/week), little is known about the health associations of other parameters. Hence, this study aimed to determine if MSE duration and volume are associated with prevalent chronic health conditions. Design: Cross-sectional. Methods: Cross-sectional data (n = 16,301 adults ≥16 years) were pooled from the Health Survey for England (2012, 2016). Respondents self-reported MSE mode (own-bodyweight, gym-based), duration and volume, and the prevalence of five chronic conditions (diabetes, anxiety/depression, heart, respiratory, or musculoskeletal condition). Poisson regressions with robust error variance were used to calculate the prevalence ratios (PR) of each chronic condition (outcome variable) across MSE parameters [exposure variables: duration (0 [reference]; 10–20; 21–59; ≥60 min/session); and volume (0 [reference]; low <mean; high ≥mean minutes/week)] for each mode and the modes combined. Results: Most adults (81.5%) did no MSE. Undertaking any MSE regardless of mode, duration or volume was associated with a reduced likelihood of diabetes (APRs 0.25–0.39), heart (APRs 0.32–0.60), respiratory (APRs 0.49–0.67), and musculoskeletal conditions (APRs 0.43–0.63), and anxiety/depression (APRs 0.46–0.68). Associations remained after adjustment for potential socio-demographic and behavioural confounders. Conclusions: While participation in own-bodyweight or gym-based-strength MSE is low, irrespective of mode, duration or volume, MSE was associated with a lower prevalence of chronic health conditions. Studies with longitudinal study designs are needed to confirm these cross-sectional findings

Regulation of CDC6, Geminin, and CDT1 in Human Cells that Undergo Polyploidization

Endomitosis is the process by which mammalian megakaryocytes become polyploid during terminal differentiation. As in other endoreplicating cells, cyclin-cdk complexes are distinctly regulated, probably to overcome the strict mechanisms that prevent rereplication in most somatic cells. We have asked whether key factors involved in the assembly and licensing of replication origins are equally regulated during endomitosis. Cdc6, cdt1, and geminin expression was analyzed during differentiation of two human megakaryoblastic cell lines, HEL and K562, which respectively do and do not establish endoreplication cycles. Geminin was downregulated, whereas cdt1 levels were maintained upon differentiation of both cell lines, independently of whether cells entered extra S-phases. In contrast, cdc6 was present and remained nuclear only in differentiated endoreplicating cells. Interestingly, cdc6 protein expression was reestablished in K562 cells that underwent endomitosis after transient or stable cyclin E overexpression. The high levels of cyclin E reached in these cells appeared to influence the stabilization of cdc6 protein rather than its RNA transcription rate. Finally, cdc6 overexpression drove HEL cells into endoreplication cycles in the absence of differentiation stimuli. Our results show that both cdt1 and cdc6 are differentially regulated during megakaryocytic differentiation and suggest an active role of cdc6 in endomitosis