In vitro toxicity of various classes of test agents using the neutral red assay on a human three-dimensional physiologic skin model.

A new three-dimensional human skin model consisting of several layers of actively dividing and metabolically active human neonatal foreskin-derived fibroblasts and epidermal keratinocytes grown on nylon mesh has been used to assess the in vitro toxicity of test agents from various classes. Utilizing a slight modification of the published neutral red viability assay for endpoint determination, we have assayed and obtained dose-dependent toxicity curves for test agents from the following classes: detergents (n = 15), alcohols (n = 5), metal chlorides (n = 10), perfumes and colognes (n = 5), shampoos (n = 4), conditioners (n = 3), moisturizers (n = 3), pesticides (n = 3), and antimicrobial preservatives (n = 4). Limited comparisons to in vivo ocular irritancy data with alcohols and detergents are encouraging.

Analysis and quantitation of the beta-amyloid precursor protein in the cerebrospinal fluid of Alzheimer's disease patients with a monoclonal antibody-based immunoassay.

One of the major clinical findings in Alzheimer's disease (AD) is the formation of deposits of beta-amyloid protein in amyloid plaques, derived from the beta-amyloid precursor protein (beta-APP). To determine the possible use of beta-APP as a diagnostic marker for AD in CSF, a monoclonal antibody-based immunoassay specific for this protein was developed. The assay does not differentiate between beta-APP695 and beta-APP751 forms but does preferentially recognize beta-APP751 complexed with a protease.