| 1. |
- Wåhlin-Larsson, Britta, 1959-, et al.
(författare)
-
Mechanistic Links Underlying the Impact of C-Reactive Protein on Muscle Mass in Elderly
- 2017
-
Ingår i: Cellular Physiology and Biochemistry. - : Karger. - 1015-8987 .- 1421-9778. ; 44:1, s. 267-278
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/AIMS: Mechanisms underlying the relationship between systemic inflammation and age-related decline in muscle mass are poorly defined. The purpose of this work was to investigate the relationship between the systemic inflammatory marker CRP and muscle mass in elderly and to identify mechanisms by which CRP mediates its effects on skeletal muscle, in-vitro.METHODS: Muscle mass and serum CRP level were determined in a cohort of 118 older women (67±1.7 years). Human muscle cells were differentiated into myotubes and were exposed to CRP. The size of myotubes was determined after immunofluorescent staining using troponin. Muscle protein synthesis was assessed using stable isotope tracers and key signalling pathways controlling protein synthesis were determined using western-blotting.RESULTS: We observed an inverse relationship between circulating CRP level and muscle mass (β= -0.646 (95% CI: -0.888, -0.405) p<0.05) and demonstrated a reduction (p < 0.05) in the size of human myotubes exposed to CRP for 72 h. We next showed that this morphological change was accompanied by a CRP-mediated reduction (p < 0.05) in muscle protein fractional synthetic rate of human myotubes exposed to CRP for 24 h. We also identified a CRP-mediated increased phosphorylation (p<0.05) of regulators of cellular energy stress including AMPK and downstream targets, raptor and ACC-β, together with decreased phosphorylation of Akt and rpS6, which are important factors controlling protein synthesis.CONCLUSION: This work established for the first time mechanistic links by which chronic elevation of CRP can contribute to age-related decline in muscle function.
|
|
| 2. |
- Tilling, Kate, et al.
(författare)
-
Development of a new method for monitoring prostate-specific antigen changes in men with localised prostate cancer : a comparison of observational cohorts
- 2010
-
Ingår i: European Urology. - : Elsevier BV. - 0302-2838 .- 1873-7560. ; 57:3, s. 446-452
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Prostate-specific antigen (PSA) measurements are increasingly used to monitor men with localised prostate cancer (PCa), but there is little consensus about the method to use. OBJECTIVE: To apply age-specific predictions of PSA level (developed in men without cancer) to one cohort of men with clinically identified PCa and one cohort of men with PSA-detected PCa. We hypothesise that among men with clinically identified cancer, the annual increase in PSA level would be steeper than in men with PSA-detected cancer. DESIGN, SETTING, AND PARTICIPANTS: The Scandinavian Prostate Cancer Group 4 (SPCG-4) cohort consisted of 321 men assigned to the watchful waiting arm of the SPCG-4 trial. The UK cohort consisted of 320 men with PSA-detected PCa in the Prostate testing for cancer and Treatment (ProtecT) study who opted for monitoring. Multilevel models describing changes in PSA level were fitted to the two cohorts, and average PSA level at age 50, change in PSA level with age, and predicted PSA values were derived. MEASUREMENTS: PSA level. RESULTS AND LIMITATIONS: In the SPCG-4 cohort, mean PSA at age 50 was similar to the cancer-free cohort but with a steeper yearly increase in PSA level (16.4% vs 4.0%). In the UK cohort, mean PSA level was higher than that in the cancer-free cohort (due to a PSA biopsy threshold of 3.0 ng/ml) but with a similar yearly increase in PSA level (4.1%). Predictions were less accurate for the SPCG-4 cohort (median difference between observed and predicted PSA level: -2.0 ng/ml; interquartile range [IQR]: -7.6-0.7 ng/ml) than for the UK cohort (median difference between observed and predicted PSA level: -0.8 ng/ml; IQR: -2.1-0.1 ng/ml). CONCLUSIONS: In PSA-detected men, yearly change in PSA was similar to that in cancer-free men, whereas in men with symptomatic PCa, the yearly change in PSA level was considerably higher. Our method needs further evaluation but has promise for refining active monitoring protocols.
|
|
