Impact of Deletions in the Prognosis of Childhood Acute Lymphoblastic Leukemia in Argentina.

An association of deletions in the IKZF1 gene (IKZF1del) with poor prognosis in acute lymphoblastic leukemia (ALL) has been demonstrated. Additional deletions in other genes (IKZF1plus) define different IKZF1del subsets. We analyzed the influence of IKZF1del and/or IKZF1plus in the survival of children with ALL.

A small fraction of dermatan sulfate with significantly increased anticoagulant activity was selected by interaction with the first complement protein.

Dermatan sulfate (DS) is a member of the family of structurally complex, sulfated, linear heteropolysaccharides called glycosaminoglycans (GAGs). It has a similar structure to heparin and heparan sulfate (HS), but with acetylgalactosamine replacing glucosamine, and the uronic acid moiety, mainly iduronic, joined 1-->3 to the hexosamine. We are studying the relationships between structure and activities of dermatan sulfate, in particular those associated with the thrombin inhibition mediated by heparin cofactor II (HCII).

Antithrombin and first complement protein recognize the same active heparin fraction.

Antithrombin (AT) high affinity of unfractionated heparin (UFH) resides in a specific pentasaccharide sequence. Heparin also regulates complement activity on the classical and the alternative pathways. Most experimental pieces of evidence accumulated show that these important activities reside in different segments of the heparin molecule.

An active fraction of unfractionated heparin from a natural source is recognized by the first component of the complement system.

Heparin is a natural glycosaminoglycan with chains consisting of alternating 1-4 linked residues of sulphated uronic acids (L-iduronic in great proportion) and D- glucosamine attached to a serine-glycine linear protein core. In our previous experiments with a low molecular weight heparin (Mr = 4.000 to 6.

Platelet endothelial cell adhesion molecule-1 expression during mouse postimplantation development.

With the aim to analyze the ontogeny of the mouse endothelium, monoclonal antibody (mAb) MEC 13.3 was used for the immunohistochemical staining of frozen sections of different stages of mouse embryo development. This mAb specifically recognizes membrane reinforcement of endothelial cells (EC) from mouse blood vessels, indicating the expression of a molecule related to the murine form of PECAM-1/CD31.