von Willebrand factor contained in a high purity FVIII concentrate (Fanhdi) binds to platelet glycoproteins and supports platelet adhesion to subendothelium under flow conditions.

Background And Objective: There is evidence suggesting that von Willebrand factor (VWF) from high purity factor VIII concentrates could be of clinical use in the management of patients suffering from VWD. We analyzed structural and functional characteristics of VWF present in a high purity factor VIII concentrate VWFHPC (Fanhdi). The multimeric structure, the ability to bind to platelet GP Ib/IX or GP IIb/IIIa, and the capacity of VWFHPC to promote platelet adhesion on injured vessels were investigated and compared with that present in standard plasma cryoprecipitates [VWFCRYO].

[Functionality of von Willebrand factor present in Fanhdi: adhesion to the vascular subendothelium in vitro].

Purpose: To study the ability of VWF present in a plasma derived high purity factor VIII concentrate (> or = 100 UI FVIII/mg of protein, Fanhdi) to promote deposition and platelet adhesion on the injured vessel wall, as an indicator of the functionality of said VWF.

Material And Methods: An in vitro perfusion system was employed. Adequate proportions of platelets and red cells were suspended in a human albumin solution.

An El Jobo Mastodon Kill at Taima-taima, Venezuela.

Excavation at Taima-taima in 1976 recovered artifacts of the El Jobo complex in direct association with the butchered remains of a juvenile mastodon. Radiocarbon dates on associated wood twigs indicate a minimum age of 13,000 years before the present for the mastodon kill, a dating significantly older than that of the Clovis complex in North America. The El Jobo complex must have evolved independently in northern South America.