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- Gross, M, et al.
(författare)
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Beta-alanine supplementation improves jumping power and affects severe-intensity performance in professional alpine skiers
- 2014
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Ingår i: International journal of sport nutrition and exercise metabolism. - : Human Kinetics. - 1543-2742 .- 1526-484X. ; 24:6, s. 665-673
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Tidskriftsartikel (refereegranskat)abstract
- Supplementation with beta-alanine may have positive effects on severe-intensity, intermittent, and isometric strength-endurance performance. These could be advantageous for competitive alpine skiers, whose races last 45 to 150 s, require metabolic power above the aerobic maximum, and involve isometric muscle work. Further, beta-alanine supplementation affects the muscle force-frequency relationship, which could influence explosiveness. We explored the effects of beta-alanine on explosive jump performance, severe exercise energy metabolism, and severe-intensity ski-like performance.Methods:Nine male elite alpine skiers consumed 4.8 g/d beta-alanine or placebo for 5 weeks in a double-blind fashion. Before and after, they performed countermovement jumps (CMJ), a 90-s cycling bout at 110% VO2max (CLT), and a maximal 90-s box jump test (BJ90).Results:Beta-alanine improved maximal (+7 ± 3%, d = 0.9) and mean CMJ power (+7 ± 2%, d = 0.7), tended to reduce oxygen deficit (-3 ± 8%, p = .06) and lactate accumulation (-12 ± 31%) and enhance aerobic energy contribution (+1.3 ± 2.9%, p = .07) in the CLT, and improved performance in the last third of BJ90 (+7 ± 4%, p = .02). These effects were not observed with placebo.Conclusions:Beta-alanine supplementation improved explosive and repeated jump performance in elite alpine skiers. Enhanced muscle contractility could possibly explain improved explosive and repeated jump performance. Increased aerobic energy production could possibly help explain repeated jump performance as well.
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| 4. |
- Mitteldorf, C., et al.
(författare)
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Expression of programmed death-1 (CD279) in primary cutaneous B-cell lymphomas with correlation to lymphoma entities and biological behaviour
- 2013
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Ingår i: British Journal of Dermatology. - : Blackwell Publishing Ltd. - 0007-0963 .- 1365-2133. ; 169:6, s. 1212-1218
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Tidskriftsartikel (refereegranskat)abstract
- Background Programmed death-1 (PD-1/CD279) is a cell-surface protein expressed in activated T cells and a subset of T lymphocytes including follicular helper T cells (TFH). The interaction between PD-1 and its ligands plays a role in immune response and evasion of malignancies. In nodal follicular lymphoma, the number of intratumoral PD-1-positive lymphocytes is associated with overall survival. Objectives To investigate 28 cases of primary cutaneous B-cell lymphoma, including the subtypes PCFCL (n = 10), PCMZL (n = 10) and DLBCL-LT (n = 8) for the number and density of PD-1-positive cells. Methods Immunohistochemical staining and a computerized morphometric analysis for evaluation were applied. The results were correlated with the clinical outcome. To distinguish between activated T cells and TFH we performed PD-1/bcl-6 double staining and compared these results with CXCL-13 staining. Double staining for PD-1 and PAX-5 was used to investigate whether tumour cells were positive for PD-1. Results The PD-1-positive cells represented tumour-infiltrating T cells (TILs). Only a minor subset was represented by TFH. Patients with DLBCL-LT had a significantly lower number of PD-1-positive TILs than those with PCMZL (P = 0·012) and PCFCL (P = 0·002) or both (P = 0·001). The difference between PCMZL and PCFCL did not reach significance (P = 0·074). The tumour cells were negative for PD-1. Conclusions A higher number of PD-1-expressing cells was found in indolent PCMZL and PCFCL than in high-malignant DLBCL-LT. The PD-1-positive cells represented not only TFH, but also other activated T cells as a part of the tumour microenvironment. The tumour cells in all investigated types of PCBCL did not show aberrant PD-1 expression. What’s already known about this topic? In nodal follicular lymphoma, the number of intratumoral programmed death (PD)-1-positive lymphocytes is associated with overall survival. No data exist for primary cutaneous B-cell lymphoma (PCBCL). What does this study add? A higher number of PD-1-expressing cells was found in indolent primary cutaneous marginal zone lymphoma and primary cutaneous follicle centre lymphoma, in contrast to the more aggressive diffuse large B-cell lymphoma, leg type. PD-1-positive cells do not represent only follicular helper T cells. The tumour cells in all investigated types of PCBCL did not show aberrant PD-1 expression. © 2013 British Association of Dermatologists.
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