PubMed Health⌕ Search

Biomedical subjects

F Y Shiau

Publications and source records attributed to F Y Shiau.

3 recordsLinked to original sources

Variant antibody identification by peptide mapping.

During development of CGP56901, a monoclonal antibody (MAb) specific for a unique epitope on human IgE, the protein A-purified IgG from one of the candidate production cell lines, showed an additional minor heavy chain (H-chain) band with a molecular weight slightly lower than that of the principal H-chain band on SDS-PAGE. The N-terminal amino acid sequence of this minor H-chain species indicated that at least the first 30 amino acids were identical to those of the antibody light-chain (L-chain) variable domain. More detailed studies using peptide mapping and amino acid sequencing analysis confirmed a crossover event between the V genes of the antibody. The position is between Arg108 of the L chain and Ala124 of the H chain. This crossover resulted in a variant H chain, which had 16 fewer amino acid residues than the normal CGP56901 H chain. These results show that peptide mapping is a useful "first-line" analytical tool in the characterization of the quality of the monoclonal antibody.

Amino Acid Sequence↗

Photosensitization with bacteriochlorins.

Biophysical and photobiological properties of a group of bacteriochlorins were compared with efficacy of these products for photodynamic therapy of murine tumors. Predictive factors for selective photosensitization in vivo include affinity binding to lipoproteins greater than albumin, extinction coefficient at the wavelength of irradiation and tumor/skin distribution. Efficacy was correlated with circulating plasma levels of the different sensitizers but not with the photodynamic therapy response in cell culture.

Animals↗

In vitro characterization of monoaspartyl chlorin e6 and diaspartyl chlorin e6 for photodynamic therapy.

The characteristics of two new chlorin photosensitizers were studied in cell culture by determining phototoxicity, subcellular localization, and photophysical properties. Monoaspartyl chlorin e6 (MACE) and diaspartyl chlorin e6 (DACE) are new photosensitizers that show promise for use in photodynamic therapy. These chlorins are pure, monomeric compounds as determined by high-pressure liquid chromatography. Both compounds absorb substantially at a longer wavelength (664 nm) than does dihematoporphyrin ether-ester (DHE). Tumor diagnosis with the use of fluorescence should be facilitated due to the purity of the compounds and the single fluorescence emission peak. Phototoxicity dose-response curves of the sensitizers were completed using a standard clonogenic assay to determine cell viability. The chlorins showed good sensitizing capabilities with light. In addition, subcellular localization of MACE, DACE, and DHE was studied using fluorescence microscopy. Whereas DHE was located throughout the cytoplasm, the primary site of localization of the chlorins appeared to be in the lysosome. The results demonstrate that MACE and DACE are effective photosensitizing agents in vitro and compare favorably to DHE.

Cell Line↗