{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T09:13:23Z","timestamp":1790154803748,"version":"4.0.1"},"reference-count":49,"publisher":"Wiley","issue":"7","license":[{"start":{"date-parts":[[2007,9,28]],"date-time":"2007-09-28T00:00:00Z","timestamp":1190937600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Arthritis &amp; Rheumatism"],"published-print":{"date-parts":[[2007,10,15]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Objective<\/jats:title><jats:p>To compare muscle fiber type composition and muscle fiber area in patients with chronic polymyositis or dermatomyositis and healthy controls, and to determine whether physical training for 12 weeks could alter these muscle characteristics.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Muscle fiber type composition and muscle fiber area were investigated by biochemical and immunohistochemistry techniques in repeated muscle biopsy samples obtained from 9 patients with chronic myositis before and after a 12\u2010week exercise program and in healthy controls. Muscle performance was evaluated by the Functional Index (FI) in myositis and by the Short Form 36 (SF\u201036) quality of life instrument.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Before exercise, the proportion of type I fibers was lower (mean \u00b1 SD 32% \u00b1 10%) and the proportion of type IIC fibers was higher (3% \u00b1 3%) in patients compared with healthy controls. After exercise, percentage of type I fiber increased to 42% \u00b1 13% (<jats:italic>P<\/jats:italic> &lt; 0.05), and type IIC decreased to 1% \u00b1 1%. An exercise\u2010induced 20% increase of the mean fiber area was also observed. The functional capacity measured by the FI in myositis and the physical functioning subscale of the SF\u201036 increased significantly. Improved physical functioning was positively correlated with the proportion of type I fibers (r = 0.88, <jats:italic>P<\/jats:italic> &lt; 0.01) and type II muscle fiber area (r = 0.70, <jats:italic>P<\/jats:italic> &lt; 0.05).<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>Low muscle endurance in chronic polymyositis or dermatomyositis may be related to a low proportion of oxidative, slow\u2010twitch type I fibers. Change in fiber type composition and increased muscle fiber area may contribute to improved muscle endurance and decreased muscle fatigue after a moderate physical training program.<\/jats:p><\/jats:sec>","DOI":"10.1002\/art.22996","type":"journal-article","created":{"date-parts":[[2007,9,28]],"date-time":"2007-09-28T22:21:05Z","timestamp":1191018065000},"page":"1303-1310","source":"Crossref","is-referenced-by-count":72,"title":["Effect of physical training on the proportion of slow\u2010twitch type I muscle fibers, a novel nonimmune\u2010mediated mechanism for muscle impairment in polymyositis or dermatomyositis"],"prefix":"10.1002","volume":"57","author":[{"given":"Maryam","family":"Dastmalchi","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Helene","family":"Alexanderson","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ingela","family":"Loell","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marcus","family":"St\u00e5hlberg","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kristian","family":"Borg","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ingrid E.","family":"Lundberg","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mona","family":"EsbJ\u00f6rnsson","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2007,9,28]]},"reference":[{"key":"e_1_2_7_2_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM197502202920807"},{"key":"e_1_2_7_3_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM197502132920706"},{"key":"e_1_2_7_4_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199111213252107"},{"key":"e_1_2_7_5_2","doi-asserted-by":"publisher","DOI":"10.7326\/0003-4819-111-2-143"},{"key":"e_1_2_7_6_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1600-0404.1982.tb03087.x"},{"key":"e_1_2_7_7_2","doi-asserted-by":"publisher","DOI":"10.1093\/rheumatology\/41.1.22"},{"key":"e_1_2_7_8_2","doi-asserted-by":"publisher","DOI":"10.1097\/00002281-200311000-00002"},{"key":"e_1_2_7_9_2","doi-asserted-by":"publisher","DOI":"10.1085\/jgp.50.6.197"},{"key":"e_1_2_7_10_2","doi-asserted-by":"publisher","DOI":"10.1001\/archneur.1970.00480280083010"},{"key":"e_1_2_7_11_2","doi-asserted-by":"publisher","DOI":"10.1038\/368113a0"},{"key":"e_1_2_7_12_2","doi-asserted-by":"publisher","DOI":"10.1177\/18.9.670"},{"key":"e_1_2_7_13_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1748-1716.1975.tb10038.x"},{"key":"e_1_2_7_14_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF00493174"},{"key":"e_1_2_7_15_2","doi-asserted-by":"publisher","DOI":"10.1177\/32.6.6202737"},{"key":"e_1_2_7_16_2","doi-asserted-by":"publisher","DOI":"10.1007\/BF00266756"},{"key":"e_1_2_7_17_2","doi-asserted-by":"publisher","DOI":"10.1139\/h97-020"},{"key":"e_1_2_7_18_2","doi-asserted-by":"publisher","DOI":"10.1097\/01.bor.0000152665.41493.49"},{"key":"e_1_2_7_19_2","doi-asserted-by":"publisher","DOI":"10.1093\/rheumatology\/38.7.608"},{"key":"e_1_2_7_20_2","doi-asserted-by":"publisher","DOI":"10.1080\/030097400447679"},{"key":"e_1_2_7_21_2","doi-asserted-by":"publisher","DOI":"10.1093\/rheumatology\/37.12.1338"},{"key":"e_1_2_7_22_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0003-9993(00)90212-0"},{"key":"e_1_2_7_23_2","doi-asserted-by":"publisher","DOI":"10.1002\/ana.410380504"},{"key":"e_1_2_7_24_2","first-page":"1380","article-title":"A functional index in myositis","volume":"23","author":"Josefson A","year":"1996","journal-title":"J Rheumatol"},{"key":"e_1_2_7_25_2","doi-asserted-by":"publisher","DOI":"10.1016\/0277-9536(95)00125-Q"},{"key":"e_1_2_7_26_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1600-0404.1979.tb02942.x"},{"key":"e_1_2_7_27_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1748-1716.1983.tb07200.x"},{"key":"e_1_2_7_28_2","doi-asserted-by":"publisher","DOI":"10.1083\/jcb.9.1.47"},{"key":"e_1_2_7_29_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.86.1.307"},{"key":"e_1_2_7_30_2","doi-asserted-by":"publisher","DOI":"10.1002\/mus.880150104"},{"key":"e_1_2_7_31_2","doi-asserted-by":"publisher","DOI":"10.1042\/bj1930229"},{"key":"e_1_2_7_32_2","doi-asserted-by":"publisher","DOI":"10.1016\/0022-510X(84)90146-1"},{"key":"e_1_2_7_33_2","doi-asserted-by":"publisher","DOI":"10.1136\/ard.54.8.654"},{"key":"e_1_2_7_34_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1748-1716.1982.tb07163.x"},{"key":"e_1_2_7_35_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-7793.2000.00243.x"},{"key":"e_1_2_7_36_2","doi-asserted-by":"publisher","DOI":"10.1139\/y85-005"},{"key":"e_1_2_7_37_2","doi-asserted-by":"publisher","DOI":"10.1002\/mus.10373"},{"key":"e_1_2_7_38_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0735-1097(02)01740-0"},{"key":"e_1_2_7_39_2","first-page":"66","article-title":"Steroid myopathy: a study of the evolution of the muscle lesion in rabbits","volume":"124","author":"Afifi AK","year":"1969","journal-title":"Johns Hopkins Med J"},{"key":"e_1_2_7_40_2","doi-asserted-by":"publisher","DOI":"10.1042\/cs0710693"},{"key":"e_1_2_7_41_2","doi-asserted-by":"publisher","DOI":"10.3109\/03009747409097142"},{"key":"e_1_2_7_42_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2265.1983.tb00030.x"},{"key":"e_1_2_7_43_2","first-page":"297","volume-title":"Biochemistry of exercise IX","author":"Jansson E","year":"1996"},{"key":"e_1_2_7_44_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM198602063140601"},{"key":"e_1_2_7_45_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1748-1716.1991.tb09102.x"},{"key":"e_1_2_7_46_2","doi-asserted-by":"publisher","DOI":"10.1007\/s11926-001-0038-x"},{"key":"e_1_2_7_47_2","doi-asserted-by":"publisher","DOI":"10.1002\/art.1780370519"},{"key":"e_1_2_7_48_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1748-1716.1990.tb09010.x"},{"key":"e_1_2_7_49_2","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-201X.2003.01158.x"},{"key":"e_1_2_7_50_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0735-1097(03)00848-9"}],"container-title":["Arthritis Care &amp; Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fart.22996","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/art.22996","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,11,15]],"date-time":"2023-11-15T01:24:06Z","timestamp":1700011446000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/art.22996"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2007,9,28]]},"references-count":49,"journal-issue":{"issue":"7","published-print":{"date-parts":[[2007,10,15]]}},"alternative-id":["10.1002\/art.22996"],"URL":"https:\/\/doi.org\/10.1002\/art.22996","archive":["Portico"],"relation":{},"ISSN":["0893-7524","1529-0123"],"issn-type":[{"value":"0893-7524","type":"print"},{"value":"1529-0123","type":"electronic"}],"subject":[],"published":{"date-parts":[[2007,9,28]]}}}