加替沙星微生物限度检查方法的建立

目的:完善加替沙星微生物限度检查方法。方法:采用薄膜过滤并在培养基中加入中和剂(0.1 mol·L~(-1)的硫酸锰溶液)的方法,去除加替沙星的抗菌活性。结果:本方法满足中国药典2005版验证试验的基本要求。5株验证菌株中枯草芽孢杆菌对加替沙星最敏感,可作为加替沙星微生物限度检查方法的质控菌株。结论:该方法可作为加替沙星口服制剂的常规微生物限度检查方法。     

Determination of adhesion force between single cell pairs generated by activated GpIIb-IIIa receptors

A biophysical approach was used to directly determine the avidity of the junction between two Chinese hamster ovary (CHO) cells bearing recombinant GpIIb-IIIa in the presence and absence of fibrinogen. Micromanipulation was used to induce conjugation of the cell pairs with or without activating the GpIIb-IIIa molecules with monoclonal antibody (MoAb) 62. Activation of GpIIb-IIIa caused an increase in the force required to separate the conjugates. The molecular bonding force between cells bearing activated GpIIb-IIIa and fibrinogen molecules was found to be 2.1 x 10(-7) dyne, which is 3.7 times higher than that between nonactivated GpIIb-IIIa and fibrinogen (5.7 x 10(-8) dyne). The results provide a quantitative assessment of the molecular bonding force between fibrinogen and the GpIIb-IIIa expressed on cell surface. The findings indicate that the activation of GpIIb-IIIa leads to an increase in the adhesive force in CHO cell aggregation by increasing the strength of the GpIIb-IIIa-fibrinogen bonds rather than the number of these bonds.