Glomerular metabolic changes in compensatory renal hypertrophy.

In compensatory hypertrophy, 7 days after unilateral nephrectomy, an increase in respiration and glucose-6-P dehydrogenase activity are observed in the glomeruli of the hypertrophied kidney. It is suggested that is is related to the clearing of an increased amount of filtration residues by the glomerular cells.     

Fast tracer efflux from membrane vesicles; investigation by controlled elution

A method has been developed to study tracer efflux from membrane vesicles. Vesicles are trapped on filters, but in contrast to conventional filtration techniques tracer efflux is measured as such. A functional integration of a commercial fraction collector, a pulse generator, and a programmable repetitive pipet with a simple electronic circuit allows monitoring of complete efflux kinetics from seconds onward. The automatic control of discrete elution steps guarantees reproducible results and makes possible a correction for background release of tracer from the filter. The dependence of efflux data on selected combinations of filters is demonstrated. These experiments also shed some light on problems intrinsic to conventional filtration procedures. The performance of the controlled elution technique is shown with ²²Na efflux from Na channel-rich membrane vesicles.     

GMP Production of Liposomes—A New Industrial Approach

A new scalable liposome production system is presented, which is based on the ethanol injection technique. The system permits liposome manufacture regardless of production scale, as scale is determined only by free disposable vessel volumes. Once the parameters are defined, an easy scale up can be performed by just changing the process vessels. These vessels are fully sterilizeable and all raw materials are transferred into the sanitized and sterilized system via 0.2 μm filters to guarantee an aseptic production.

Liposome size can be controlled by the local lipid concentration at the injection point depending on process parameters like injection pressure, lipid concentration and injection rate. These defined process parameters are furthermore responsible for highly reproducible results with respect to vesicle diameters and encapsulation rates Compared to other technologies like the film method which is normally followed by size reduction through high pressure homogenization, ultrasonication or extrusion, no mechanical forces are needed to generate homogeneous and narrow distributed liposomes.

Another important advantage of this method is the suitability for the entrapment of many different drug substances such as large hydrophilic proteins by passive encapsulation, small amphiphilic drugs by a one step remote loading technique or membrane association of antigens for vaccination approaches