No substitute for β3 integrin

Affinity Modulation of Platelet Integrin αIIbβ3 by β3-Endonexin, a Selective Binding Partner of the β3 Integrin Cytoplasmic Tail

Platelet agonists increase the affinity state of integrin alphaIIbbeta3, a prerequisite for fibrinogen binding and platelet aggregation. This process may be triggered by a regulatory molecule(s) that binds to the integrin cytoplasmic tails, causing a structural change in the receptor. beta3-Endonexin is a novel 111-amino acid protein that binds selectively to the beta3 tail. Since beta3-endonex...

'Nosodes' are no substitute for vaccines.

A growing antivaccine movement in Canada and elsewhere is hearing more about an unproven homeopathic therapy, 'nosodes', as an alternative to routine vaccines. The present statement defines nosodes and describes limitations for their use in children. There is scant evidence in the medical literature for either the efficacy or safety of nosodes, which have not been well studied for the preventio...

No substitute for the clinician-teacher.

Exposure of ligand-binding sites on platelet integrin αIIB/β3 by phosphorylation of the β3 subunit

The exposure of ligand-binding sites for adhesive proteins on platelet integrin α IIB }β $ (glycoprotein IIB}IIIA) by plateletactivating factor (PAF) is transient, whereas sites exposed by αthrombin remain accessible. The same difference is seen in the phosphorylation of the β $ subunit. Inhibition of protein kinases (1 μM staurosporine) and protein kinase C (10 μM bisindolylmaleimide) closes b...

Decreased stability of erythroblastic islands in integrin β3-deficient mice

Erythroblasts proliferate and differentiate in hematopoietic organs within erythroblastic islands (EI) composed of erythropoietic progenitor cells attached to a central macrophage. This cellular interaction crucially involves the erythroid intercellular adhesion molecule-4 (ICAM-4) and αv integrin. Because integrins are biologically active as α/β heterodimers, we asked whether β3 could be a het...