{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T15:48:09Z","timestamp":1781106489777,"version":"3.54.1"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"3","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1972,3]]},"abstract":"<jats:p>\n                    Relatively low concentrations of methylxanthines increase spontaneous twitching in cultured muscle fibers; they also cause a second activity, escalation, which is the initiation and undiminished propagation of visible waves. The effect on twitching is abolished by depolarizing concentrations of K\n                    <jats:sup>+<\/jats:sup>\n                    or by tetrodotoxin; the effect on escalation is not. Escalation is prevented by removal of external Ca\n                    <jats:sup>++<\/jats:sup>\n                    or by the addition of tetracaine.\n                  <\/jats:p>","DOI":"10.1073\/pnas.69.3.613","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T02:33:44Z","timestamp":1149042824000},"page":"613-616","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":5,"title":["Methylxanthine-Induced Escalation: A Propagated Wave Phenomenon Observed in Skeletal Muscle Developing in Culture"],"prefix":"10.1073","volume":"69","author":[{"given":"Annette W.","family":"Coleman","sequence":"first","affiliation":[{"name":"Division of Biological and Medical Sciences, Brown University, Rhode Island 02912"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John R.","family":"Coleman","sequence":"additional","affiliation":[{"name":"Division of Biological and Medical Sciences, Brown University, Rhode Island 02912"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"James D.","family":"Griffin","sequence":"additional","affiliation":[{"name":"Division of Biological and Medical Sciences, Brown University, Rhode Island 02912"},{"name":"Department of Medicine, the Miriam Hospital, Providence, Rhode Island 02912"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joel K.","family":"Weltman","sequence":"additional","affiliation":[{"name":"Division of Biological and Medical Sciences, Brown University, Rhode Island 02912"},{"name":"Department of Medicine, the Miriam Hospital, Providence, Rhode Island 02912"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K. M.","family":"Chapman","sequence":"additional","affiliation":[{"name":"Division of Biological and Medical Sciences, Brown University, Rhode Island 02912"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1972,3]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.69.3.613","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T10:37:42Z","timestamp":1649846262000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.69.3.613"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1972,3]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1972,3]]}},"alternative-id":["10.1073\/pnas.69.3.613"],"URL":"https:\/\/doi.org\/10.1073\/pnas.69.3.613","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1972,3]]},"assertion":[{"value":"1972-03-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}