Axon regeneration in the CNS is largely unsuccessful due to excess inhibitory extrinsic factors within lesion sites together with an intrinsic inability of neurons to regrow following injury. Recent work demonstrates ...Axon regeneration in the CNS is largely unsuccessful due to excess inhibitory extrinsic factors within lesion sites together with an intrinsic inability of neurons to regrow following injury. Recent work demonstrates that forced expression of certain neuronal transmembrane receptors can recapitulate neuronal growth resulting in successful growth within and through inhibitory lesion environments. More specifically, neuronal expression of integrin receptors such as alpha9beta1 integrin which binds the extracellular matrix glycoprotein tenascin-C, trk receptors such as trk B which binds the neurotrophic factor BDNF, and receptor PTPσ which binds chondroitin sulphate proteoglycans, have all been show to significantly enhance regeneration of injured axons. We discuss how reintroduction of these receptors in damaged neurons facilitates signalling from the internal environment of the cell with the external environment of the lesion milieu, effectively resulting in growth and repair following injury. In summary, we suggest an appropriate balance of intrinsic and extrinsic factors are required to obtain substantial axon regeneration.展开更多
Batifiban, a synthetic cyclic peptide, is a potent platelet glycoprotein GPⅡb/Ⅲa antagonist which may be useful in the treatment and prevention of acute coronary syndromes. The pharmacokinetics and pharmacodymanic ...Batifiban, a synthetic cyclic peptide, is a potent platelet glycoprotein GPⅡb/Ⅲa antagonist which may be useful in the treatment and prevention of acute coronary syndromes. The pharmacokinetics and pharmacodymanic （inhibition of platelet aggregation） effects, and tolerability of batifiban were investigated in healthy subjects following single bolus injection with doses of 55, 110, or 220 μg/kg, or multiple doses of an bolus followed intravenous infusion for 24 h （180 μg/kg plus 2.0 μg/minokg, and 220 μg/kg plus 2.5μg/minokg） in this phase I clinical trial. Plasma levels of batifiban and areas under the curve were found to be proportional to doses. Batifiban was rapidly eliminated with a half-life of approximately 2.5 h. Significant differences were noted for plasma levels of batifiban and areas under the curve between males and females. No significant differences in the terminal half-life were found between males and females. Batifiban reversibly inhibited ex vivo platelet aggregation in a dose- and concentration-dependent manner, consistent with its mechanism as a GPⅡ b/Ⅲa antagonist. Single and multiple intravenous doses of batifiban were found to be safe and well tolerated in healthy subjects. These results support a bolus injection plus intravenous infusion regimen of batifiban for the treatment and prevention of acute coronary syndromes.展开更多
文摘Axon regeneration in the CNS is largely unsuccessful due to excess inhibitory extrinsic factors within lesion sites together with an intrinsic inability of neurons to regrow following injury. Recent work demonstrates that forced expression of certain neuronal transmembrane receptors can recapitulate neuronal growth resulting in successful growth within and through inhibitory lesion environments. More specifically, neuronal expression of integrin receptors such as alpha9beta1 integrin which binds the extracellular matrix glycoprotein tenascin-C, trk receptors such as trk B which binds the neurotrophic factor BDNF, and receptor PTPσ which binds chondroitin sulphate proteoglycans, have all been show to significantly enhance regeneration of injured axons. We discuss how reintroduction of these receptors in damaged neurons facilitates signalling from the internal environment of the cell with the external environment of the lesion milieu, effectively resulting in growth and repair following injury. In summary, we suggest an appropriate balance of intrinsic and extrinsic factors are required to obtain substantial axon regeneration.
文摘Batifiban, a synthetic cyclic peptide, is a potent platelet glycoprotein GPⅡb/Ⅲa antagonist which may be useful in the treatment and prevention of acute coronary syndromes. The pharmacokinetics and pharmacodymanic （inhibition of platelet aggregation） effects, and tolerability of batifiban were investigated in healthy subjects following single bolus injection with doses of 55, 110, or 220 μg/kg, or multiple doses of an bolus followed intravenous infusion for 24 h （180 μg/kg plus 2.0 μg/minokg, and 220 μg/kg plus 2.5μg/minokg） in this phase I clinical trial. Plasma levels of batifiban and areas under the curve were found to be proportional to doses. Batifiban was rapidly eliminated with a half-life of approximately 2.5 h. Significant differences were noted for plasma levels of batifiban and areas under the curve between males and females. No significant differences in the terminal half-life were found between males and females. Batifiban reversibly inhibited ex vivo platelet aggregation in a dose- and concentration-dependent manner, consistent with its mechanism as a GPⅡ b/Ⅲa antagonist. Single and multiple intravenous doses of batifiban were found to be safe and well tolerated in healthy subjects. These results support a bolus injection plus intravenous infusion regimen of batifiban for the treatment and prevention of acute coronary syndromes.
