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Biomedical subjects

C Spence

Publications and source records attributed to C Spence.

60 records · Page 4Linked to original sources

Reliability of goniometric measurements.

This study determined the intratester and intertester variability and reliability of goniometric measurements taken by four physical therapists on upper and lower extremity motions of normal male subjects. The same subjects were measured once weekly for four weeks by testers with varied experience in goniometry. Data were analyzed by analyses of variance with repeated measures. Intratester variation for all measurements was less than intertester variation. Further, intertester variation was less for the three upper extremity motions than for those of the lower extremity. These findings indicate the necessity for using the same tester when effects of treatment are evaluated. When the same tester measures the same movement, increases in joint motion of at least three to four degrees determine improvement for either the upper or lower extremity. When more than one tester, however, measures the same movement, increases in joint motion should exceed five degrees for the upper extremity and six degrees for the lower extremity to determine improvement.

Adult↗

Fluidized-bed receptor-affinity chromatography.

A multipurpose fluidized-bed receptor-affinity purification system based upon the biological recognition between an immobilized receptor and its soluble protein ligands is described. The fluidized affinity sorbent consists of a soluble form of interleukin-2 receptor chemically bonded to an aldehyde derivative of controlled pore glass beads, which have a pore diameter of 1000 A and a particle density of 1.2-1.3 g/mL. The fluidized-bed separation device used in this study consists of a specially designed column fitted at the inlet end with a perforated distributor plate covered with a screen and the top outlet with an adjustable piston. The fluidized-bed consisting of a loose gel matrix permits the unimpeded passage of cell debris and particulate matter, while the target protein is captured by the affinity beads. Purification of the humanized-anti-Tac monoclonal antibody is used as a model system to determine the operational parameters. Also, fluidized-bed receptor-affinity chromatography has been successfully employed in the purification of recombinant interleukin-2 and single chain anti-Tac(Fv)-Pseudomonas exotoxin immunotoxin from unclarified inclusion body extracts. Overall, fluidized-bed receptor-affinity chromatography is found to be a productive affinity method suitable for the purification of recombinant human interleukin-2 and related molecules.

ADP Ribose Transferases↗

Affinity purification and characterization of anti-Tac(Fv)-C3-PE38KDEL: A highly potent cytotoxic agent specific to cells bearing IL-2 receptors.

A chimeric, single chain antibody fused immunotoxin, denoted anti-Tac(Fv)-C3-PE38KDEL, was engineered and expressed in Escherichia coli. The microbially expressed anti-Tac(Fv)-C3-PE38KDEL was solubilized from inclusion bodies using guanidine hydrochloride, and subsequently refolded in a redox buffer via thiol/disulfide exchange. The recombinant immunotoxin from the crude extract was purified employing receptor-affinity chromatography, which is based upon biological function and involved the immobilized p55 subunit of human IL-2 receptor. The cytotoxic activity of this immunotoxin was measured by the IL-2 dependent phytohemagglutinin (PHA) blast proliferation inhibition and HUT-102 protein synthesis inhibition assays, in which the IC50 values were 41.5 and 0.8 pM, respectively. The biochemical homogeneity and authenticity of the purified material were determined by gel permeation chromatography, amino acid composition and N-terminal sequence analyses, SDS-PAGE, isoelectric focusing, and Western blotting. The receptor-affinity-purified immunotoxin was shown to be highly effective in specifically killing cells bearing IL-2 receptors. Anti-Tac(Fv)-C3-PE38KDEL is a powerful immunosuppressant which may be a potentially useful therapeutic agent in the prevention of allograft rejection and in the treatment of autoimmune diseases. Another anticipated application of this fusion protein is as a chemotoxin in the treatment of some forms of cancer.

ADP Ribose Transferases↗