{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T22:41:19Z","timestamp":1789598479058,"version":"build-2803163510"},"reference-count":0,"publisher":"Georg Thieme Verlag KG","issue":"05","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Thromb Haemost"],"published-print":{"date-parts":[[2010]]},"abstract":"<jats:title>Summary<\/jats:title><jats:p>Previous studies investigating continuous unfractionated heparin (UFH) therapy report age-related differences in UFH response in children, as measured by APTT and anti-Xa assay. This study determined the age-related response following administration of a single UFH bolus of 75\u2013100 IU\/kg in children. Venous blood samples were collected from children (n=56) at 15, 30, 45 and 120 minutes post-UFH. Anti-Xa, anti-IIa, APTT, TCT and protamine titration were performed on all samples. Age-dependent differences in the effect and concentration of UFH were identified for the anti-Xa, anti-IIa and protamine titration as-says, respectively. In addition, a trend suggesting a proportional increase in anti-Xa and anti-IIa-mediated UFH effect with age was evident. Logistic regression demonstrated an increase in protamine titration of 0.6 IU\/ml for every year of age in samples collected 15 minutes post-UFH. UFH-mediated anti-IIa activity was reduced compared to anti-Xa activity across childhood, with a two-fold increase in anti-Xa to anti-IIa ratio in infants less than one year of age compared to teenagers in the setting of high UFH concentrations. This study demonstrates that the previously reported age-dependent response to UFH occurs in the context of an age-dependent serum concentration of UFH. The trend toward increased UFH serum concentration and anticoagulant activity with age may be related to short-term differences in UFH binding to coagulant and competitive plasma proteins in vivo.<\/jats:p>","DOI":"10.1160\/th09-09-0624","type":"journal-article","created":{"date-parts":[[2010,2,19]],"date-time":"2010-02-19T13:04:59Z","timestamp":1266584699000},"page":"1085-1090","source":"Crossref","is-referenced-by-count":45,"title":["Age is a determinant factor for measures of concentration and effect in children requiring unfractionated heparin"],"prefix":"10.1160","volume":"103","author":[{"given":"Vera","family":"Ignjatovic","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Linda","family":"Johnston","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Robyn","family":"Summerhayes","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Geoff","family":"Lane","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Noel","family":"Cranswick","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paul","family":"Monagle","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fiona","family":"Newall","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"194","published-online":{"date-parts":[[2017,11,22]]},"container-title":["Thrombosis and Haemostasis"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/www.thieme-connect.de\/products\/ejournals\/pdf\/10.1160\/TH09-09-0624.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2018,3,20]],"date-time":"2018-03-20T10:44:33Z","timestamp":1521542673000},"score":1,"resource":{"primary":{"URL":"http:\/\/www.thieme-connect.de\/DOI\/DOI?10.1160\/TH09-09-0624"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2010]]},"references-count":0,"journal-issue":{"issue":"05","published-online":{"date-parts":[[2017,11,22]]},"published-print":{"date-parts":[[2010]]}},"URL":"https:\/\/doi.org\/10.1160\/th09-09-0624","relation":{},"ISSN":["0340-6245","2567-689X"],"issn-type":[{"value":"0340-6245","type":"print"},{"value":"2567-689X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2010]]}}}