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Biomedical subjects

H Grunfeld

Publications and source records attributed to H Grunfeld.

4 recordsLinked to original sources
PubMed1997

Reduction of bovine immunoglobulin contamination from monoclonal antibodies by SOURCE 15PHE chromatography.

The presence of bovine immunoglobulin in cell culture media, and its nature as a polyclonal antibody, imposes increasing difficulties in resolution from the MAb intended for in vivo human applications. Particular difficulties are encountered when murine MAbs are the target antibody. This study presents model cases to simulate this problem, and suggests an efficient method for reduction of bovine IgG (BGG) from MAb preparations. Utilizing the new small particle size hydrophobic interaction chromatography resin, SOURCE 15PHE, up to complete resolution was achieved with a chimeric MAb. A 17-fold reduction of BGG was achieved with a murine MAb. In both cases, high recoveries of the MAb were obtained. The general applicability of the method is suggested.

Animals↗
PubMed1992

Effector-assisted refolding of recombinant tissue-plasminogen activator produced in Escherichia coli.

Recombinant tissue-plasminogen activator (r-tPA), expressed in Escherichia coli cells in an aggregated form, was solubilized with a strong chaotrope in the absence of any reducing agent. The solubilized molecule was reactivated by a procedure that was developed to mimic the physiological conditions optimal for the functional folding and activity of the native protein. The use of partially purified fibrinogen, as a source of fibrin (the effector), is shown to facilitate the reactivation process and increase its yield by at least a factor of two. The yield of the process is also shown to be particularly dependent on the recombinant protein concentration. At a concentration level of 3-3.7 mg r-tPA/L in the reactivation mixture, up to a 90% yield of activity was obtained. Purification of the activated form of r-tPA was achieved with a two-step column-chromatography scheme. This included a gel filtration step on a Sephadex G-50 column followed by an affinity chromatography step on a lysine-sepharose column. The product was composed of roughly equal amounts of one-chain and two-chain t-PA. The feasibility of using a two water-soluble polymeric phase system, with a centrifugal partition chromatography (CPC), in scaling up the reactivation process or the purification step was also evaluated.

Chromatography, Affinity↗
PubMed1986

Enzyme-based hemoperfusion and blood treatment.

Enzyme-based artificial organs are being developed as metabolic assist devices. These are required when normal metabolism is impaired, or when the body is overloaded by undesired metabolites or toxins. The implementations of this approach for treating a genetic disease, and for metabolic support in liver failure are envisaged. The kinetic aspects and mass transfer characteristics of bioreactors for these systems are considered in detail.

Blood↗