Relationship between human development and disappearance of unusually large von Willebrand factor multimers from plasma.

摘要: von Willebrand factor (vWF) multimers were examined in fetal, umbilical cord, and neonatal platelet-poor plasma (PPP) specimens. Sixty-five of 65 (100%) fetal PPP samples aged less than 35 weeks seven ten (70%) greater had unusually large vWF (ULvWF) multimers. Thirty 46 (65%) cord from neonates ranging gestational age 34 to 41 ULvWF. There was no significant relationship between either at time delivery or birth weight likelihood finding ULvWF samples. No maternal sample contained Serial heelstick 16 preterm term analyzed for 8 weeks. disappeared the during this time. The four patterns similar those normal adult throughout sampling period. multimeric forms constitutively released endothelial cells. They not as slowly migrating a very porous 0.5% agarose gel system Weibel-Palade bodies response calcium ionophore A23187. A protomer present 97% samples, 83% blood specimens, 11% but found any sample. These results indicate that control mechanisms operative older children adults prevent circulation protomeric are normally acquired late uterine life multimers, which components most some may contribute utero postnatal hemostasis.