Biomedical subjects

Sabine Arnold

Publications and source records attributed to Sabine Arnold.

3 recordsLinked to original sources

PubMed2005

High-throughput lipophilicity measurement with immobilized artificial membranes.

We report on a new, high-throughput assay designed to measure octanol/water partition coefficients in early drug discovery. The assay is carried out in 96-well microtiterplates and measures the diffusion of compounds between two aqueous compartments separated by a thin octanol liquid layer. Octanol/water partition coefficients are derived from the apparent permeability (P(a)) values using a calibration curve. The assay can measure partition coefficients within the range -2 to + 8; thus, a dynamic range of 10 log units can be covered in one single run. Unlike chromatographic methods, the technology is not restricted to neutral and weakly basic compounds, and, as no stationary phase is involved, the data can be strictly compared with values obtained from traditional methods such as shake-flask/HPLC or dual-phase potentiometric titration.

1-Octanol↗

PubMed2005

Model-based inference of gene expression dynamics from sequence information.

A dynamic model of prokaryotic gene expression is developed that makes considerable use of gene sequence information. The main contribution arises from the fact that the combined gene expression model allows us to access the impact of altering a nucleotide sequence on the dynamics of gene expression rates mechanistically. The high level of detail of the mathematical model is considered as an important step towards bringing together the tremendous amount of biological in-depth knowledge that has been accumulated at the molecular level, using a systems level analysis (in the sense of a bottom-up, inductive approach). This enables to the model to provide highly detailed insights into the various steps of the protein expression process and it allows us to access possible targets for model-based design. Taken as a whole, the mathematical gene expression model presented in this study provides a comprehensive framework for a thorough analysis of sequence-related effects on the stages of mRNA synthesis, mRNA degradation and ribosomal translation, as well as their nonlinear interconnectedness. Therefore, it may be useful in the rational design of recombinant bacterial protein synthesis systems, the modulation of enzyme activities in pathway design, in vitro protein biosynthesis, and RNA-based vaccination.

Base Sequence↗

PubMed2004

Banning antimicrobial growth promoters in feedstuffs does not result in increased therapeutic use of antibiotics in medicated feed in pig farming.

OBJECTIVE: We analysed prescription patterns for medicated feedstuffs to find out whether the ban on nutritive antimicrobial growth promotion introduced in Switzerland in 1999 had caused an increase in the therapeutic use of antimicrobial agents given orally to piglets and fattening pigs. METHODS: From 1996 to 2001, a total of 6427 prescriptions were evaluated for medicated pig feed delivered to pig farms in the Swiss canton of St Gall. Prescribed daily doses (PDD) were derived for 14 active ingredients. The overall amount and the potency of antimicrobial agents were measured in relation to the size of the pig population (PDD/population). RESULTS: The use of antimicrobial agents decreased between 1996 (1200 kg) and 1999 (708 kg) and increased thereafter from 779 kg in 2000 to 936 kg in 2001. The PDD/population (6.1 in 1996 and 3.6 in 1999) remained low (3.3 in 2000 and 3.4 in 2001). The difference between the two parameters can be explained by changes in prescribing patterns, namely a reduction in antimicrobial therapy of respiratory diseases in fattening pigs and a shift to antimicrobial treatment of gastrointestinal-tract infections in piglets using drugs with a high PDD.

Animal Feed↗