[1] NIAMSD, Muscle Dis Unit, Lab Muscle Stem Cells & Gene Regulat, NIH, Bethesda, MD 20892 USA
[2] Johns Hopkins Univ, Sch Med, Dept Neurol, Baltimore, MD 21205 USA
[3] Univ Oberta Catalunya, Fac Hlth Sci, Barcelona, Spain
[4] Univ Oberta Catalunya, Fac Comp Sci Multimedia & Telecommun, Barcelona, Spain
[5] NIEHS, Enivironmental Autoimmun Grp, NIH, Bethesda, MD USA
[6] Hosp Clin Barcelona, Internal Med, Barcelona, Catalunya, Spain
[7] Univ Autonoma Barcelona, Vall dHebron Gen Hosp, Internal Med, Barcelona, Spain
[8] Johns Hopkins Univ, Sch Med, Dept Med, Div Rheumatol, Baltimore, MD 21205 USA