A chromatographic method was employed to study the kinetics of human serum albumin (HSA) adsorbed on immobilized monoclonal antibodies. The antibodies of various specificities were covalently bound to a high-performance liquid chromatography (HPLC) silica support. For very low desorption rates, successive amounts of the reacting protein were injected until column saturation. The analysis of the increase of the non-retained fraction calculated from peak area measurements gives the capacity of the support and the rate of the biospecific adsorption process. The model is based on a second-order Langmuir kinetic law and assumes a global mass transfer for the adsorption process. The use of a silica support of small pore size permits the reduction of the contribution for mass transfer in the stagnant fluid and the decrease in the column capacity: due to its large size, the reacting molecule is adsorbed on the external surface of the particle. The adsorption rate constants of HSA on five monoclonal anti-HSA antibodies of different specificities were determined. For all the immuno-adsorbents studied, the adsorption rate constant is significantly lower than that found on immobilized polyclonal antibodies. Measurements at different flow rates reveal that the mass transfer due to the transport to the adsorbent surface is small and can be estimated.

Adsorption↗

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[Value of vitrectomy in intermediate uveitis and Behçet's disease with hyalitis. A study of 400 cases].

Can vitrectomy help to understand the vitreous role in intermediate uveitis and Behçet's disease with vitritis without retinal detachment? 400 vitrectomies were decided because of vitreous changes but, over all, if macular changes were seen clinically or on the angiogram in 58 Behçet's disease and 342 intermediate uveitis including 59 children cases. Visual acuity, clinical, angiographical and visual field controls, recurrences, reduction of the medical treatment and growth were followed during 1 to 9 years. The vitrectomy products were compared to those of other inflammatory origin vitreous, the both representing 149 cases. Vitrectomy at the early stage of only posterior interface changes prevent the macular edema but this one is irreversible. The preexisting angiographical lesions have not regressed but they are generally quiet. The RD incidence is lower even if it is possible after vitrectomy, in 1.2% of the cases (1% in late vitrectomies). Recurrences and further medical treatment are reduced. This psychological point of view is important. Thus, vitrectomy at alone posterior interface change stage avoid ocular complications. Its pathogenic role in intermediate uveitis is not demonstrated; it seems more a secondary than a primary process.

Adult↗

PubMedDate not supplied