Publications by authors named "A S Weiskopf"

Newborns are able to neurally discriminate between speech and nonspeech right after birth. To date it remains unknown whether this early speech discrimination and the underlying neural language network is associated with later language development. Preterm-born children are an interesting cohort to investigate this relationship, as previous studies have shown that preterm-born neonates exhibit alterations of speech processing and have a greater risk of later language deficits.

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Analogs of 1α,25-dihydroxyvitamin D (S1) with 20-epi modification (20-epi analogs) possess unique biological properties. We previously reported that 1α,25-dihydroxy-20-epi-vitamin D (S2), the basic 20-epi analog is metabolized into less polar metabolites (LPMs) in rat osteosarcoma cells (UMR-106) but not in a perfused rat kidney. Furthermore, we also noted that only selective 20-epi analogs are metabolized into LPMs.

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Hydrogen deuterium exchange coupled to mass spectrometry (HDX-MS) has become an established method for analysis of protein higher order structure. Here, we use HDX-MS methodology based on manual solid-phase extraction (SPE) to allow fast and simplified conformational analysis of proteins under pharmaceutically relevant formulation conditions. Of significant practical utility, the methodology allows global HDX-MS analyses to be performed without refrigeration or external cooling of the setup.

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When highly concentrated, an antibody solution can exhibit unusual behaviors, which can lead to unwanted properties, such as increased levels of protein aggregation and unusually high viscosity. Molecular modeling, along with many indirect biophysical measurements, has suggested that the cause for these phenomena can be due to short range electrostatic and/or hydrophobic protein-protein interactions. Hydrogen/deuterium exchange mass spectrometry (HDX-MS) is a useful tool for investigating protein conformation, dynamics, and interactions.

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Measurement and characterization of subvisible particles (including proteinaceous and non-proteinaceous particulate matter) is an important aspect of the pharmaceutical development process for biotherapeutics. Health authorities have increased expectations for subvisible particle data beyond criteria specified in the pharmacopeia and covering a wider size range. In addition, subvisible particle data is being requested for samples exposed to various stress conditions and to support process/product changes.

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