Multi epitope-targeting immunoprecipitation using F(ab') fragments with high affinity and specificity for the enhanced detection of a peptide with matrix-assisted laser desorption ionization-time-of-flight mass spectrometry.

Human plasma has been frequently studied using mass spectrometry for new biomarker discovery, although detection of low-abundance biological molecules can be challenging due to sample complexity and dynamic protein concentration ranges of plasma proteins. While immunoprecipitation coupled with mass spectrometric analysis is an essential method for overcoming this difficulty, its sensitivity can be insufficient to detect clinically relevant circulating biomarkers because of limited antibody affinity or specificity. To increase antibody affinity, we developed a strategy using a F(ab') fragment coupled to polyethylene glycol.

Flexible antibodies with nonprotein hinges.

There is a significant need for antibodies that can bind targets with greater affinity. Here we describe a novel strategy employing chemical semisynthesis to produce symmetroadhesins: antibody-like molecules having nonprotein hinge regions that are more flexible and extendible and are capable of two-handed binding. Native chemical ligation was carried out under mild, non-denaturing conditions to join a ligand binding domain (Aβ peptide) to an IgG1 Fc dimer via discrete oxyethylene oligomers of various lengths.

A novel phenotypic drug susceptibility assay for human immunodeficiency virus type 1.

Although combination antiretroviral therapy has resulted in a considerable improvement in the treatment of human immunodeficiency virus (HIV) type 1 (HIV-1) infection, the emergence of resistant virus is a significant obstacle to the effective management of HIV infection and AIDS. We have developed a novel phenotypic drug susceptibility assay that may be useful in guiding therapy and improving long-term suppression of HIV replication. Susceptibility to protease (PR) and reverse transcriptase (RT) inhibitors is measured by using resistance test vectors (RTVs) that contain a luciferase indicator gene and PR and RT sequences derived from HIV-1 in patient plasma.

The influence of CYP2D6 polymorphism and quinidine on the disposition and antitussive effect of dextromethorphan in humans.

Objectives: We studied the disposition of dextromethorphan in extensive and poor metabolizer subjects, as well as the effect of this polymorphism on the antitussive action of dextromethorphan.

Methods: Six extensive metabolizers were studied on four occasions: (1) after 30 mg dextromethorphan, (2) after 30 mg dextromethorphan 1 hour before 50 mg quinidine, (3) after placebo, and (4) after 50 mg quinidine. Six poor metabolizers were studied on two occasions: (1) after 30 mg dextromethorphan and (2) after placebo.

Production of antigen-specific human antibodies from mice engineered with human heavy and light chain YACs.

Our paper describes the introduction of large fragments of both the human heavy and light chain Ig genes into the mouse germline to create a mouse strain capable of producing a broad repertoire of antigen-specific, fully human antibodies. The human immunoglobulin gene sequences were functional in the context of the mouse machinery for antibody recombination and expression, either in the presence or absence of functional endogenous genes. This was demonstrated by their ability to undergo diverse rearrangement, to be expressed at significant levels, and to exclude expression of mouse immunoglobulins irrespective of their copy number or site of integration.