A direct comparison of the antigen-specific antibody profiles of intravenous immunoglobulins derived from US and UK donor plasma.

BACKGROUND AND OBJECTIVES: Intravenous immunoglobulin (IVIG) is used in a range of immunodeficiency states that require a broad spectrum of protective antibodies to a range of common pathogens. A comparison of the antigen-specific antibody profile of preparations of an IVIG (Vigam) derived from US and UK sourced plasma was performed, and these preparations were also compared with three other IVIG products from different manufacturers. MATERIALS AND METHODS: Antibodies against a range of bacterial and viral pathogens were measured by immunoassay. RESULTS: Similar profiles were found for Vigam made from UK and US source plasma and also for the other three IVIGs tested, but some specific differences were observed. CONCLUSIONS: IVIG preparations have a similar therapeutic spectrum of antibodies when prepared from plasma sourced either from the UK or the US.

Clinical experience with a new solvent detergent-treated intravenous immunoglobulin free of hypotensive effects.

OBJECTIVE: To see if modifications to the processing of intravenous immunoglobulin to include a virus inactivation stage alter immunoglobulin G (IgG) resulting in hypotension in patients. METHODS: Clinical trials were done involving extensive patient monitoring during infusion: in vitro - testing for markers of hypotension, and in vivo - an animal model which closely simulates clinical use. RESULTS: No hypotensive response was seen in the animal model or clinical trial. CONCLUSIONS: The production process used does not damage IgG or create vaso-active kinins as the preparation was free of hypotensive effects.

A thermodynamic approach to hormone-receptor interaction; application to insulin binding to adipocytes, adipocyte plasma membranes and liposomes incorporating adipocyte insulin receptors.

The binding of insulin to its receptor in rat adipocyte and isolated plasma membranes has been measured. The adipocyte insulin receptor has been reconstituted in lecithin liposomes and the binding of insulin investigated. A method of interpreting binding data presented as binding vs. the logarithm of free insulin concentration (binding isotherms) in terms of the binding potential concept of Wyman (1965) is described, and the results are compared with the commonly used Scatchard analysis of binding. The binding potential approach enables binding constants and Gibbs energies of formation of the insulin-receptor complex to be determined as a function of insulin bound. The limiting Gibbs energies of binding at 15 degrees C to intact cells, membranes and liposomes were found to be -55, -52 and -49 kJ mol-1 respectively. The affinity of the receptor for insulin decreases smoothly with increase in binding in all three systems. For intact adipocytes the number of insulin receptors per cell is found to be approximately 43,000.

The effect of membrane composition and alcohols on the insulin-sensitive reconstituted monosaccharide-transport system of rat adipocyte plasma membranes.

The monosaccharide transporter from the plasma membranes of rat adipocytes and insulin-stimulated adipocytes has been reconstituted in sonicated liposomes. The stereospecific D-glucose uptake by liposomes made from a range of phospholipids and incorporating fatty acids has been investigated. D-Glucose uptake is correlated with an increase in lipid fluidity as a consequence of the addition of fluidizing fatty acids, changes in phospholipid acyl chain length and temperature. Benzyl alcohol and ethyl alcohol, which are generally considered to increase bilayer fluidity, decrease stereo-specific D-glucose uptake in both whole adipocytes and reconstituted liposomes. It is suggested that, although these alcohols may affect D-glucose transport by lipid-mediated fluidity changes, they also interact directly with the transporter resulting in inhibition of transport.