Continuous rods of macroporous polymer as high-performance liquid chromatography separation media

The mammalian gut microbiota interact extensively with the host through metabolic exchange and co-metabolism of substrates. Such metabolome-metabolome interactions are poorly understood, but might be implicated in the aetiology of many human diseases. In this paper, we assess the importance of the gut microbiota in influencing the disposition, fate and toxicity of drugs in the host, and conclude that appropriate consideration of individual human gut microbial activities will be a necessary part of future personalized health-care paradigms.

Gut microorganisms, mammalian metabolism and personalized health care

Continuous porous silica rods consisting of a mesoporous (pore size, 14 or 25 nm) silica skeleton of ∼1 μm size and through-pores of ∼1.7 μm were prepared and derivatized to C18 phase by on-column reaction with octadecyldimethyl-(N,N-diethylamino)silane. The C18 silica rods gave plate heights of 10−20 μm for aromatic hydrocarbons in 80% methanol and 20−40 μm for insulin in acetonitrile−water mixtures in the presence of trifluoroacetic acid. The performance of the silica rods was much better at a high flow rate than that of conventional columns packed with 5 μm C18 silica particles having 12 and 30 nm pores, especially for high molecular weight species.

Octadecylsilylated Porous Silica Rods as Separation Media for Reversed-Phase Liquid Chromatography

Ecosystem stewardship is an action-oriented framework intended to foster the social-ecological sustainability of a rapidly changing planet. Recent developments identify three strategies that make optimal use of current understanding in an environment of inevitable uncertainty and abrupt change: reducing the magnitude of, and exposure and sensitivity to, known stresses; focusing on proactive policies that shape change; and avoiding or escaping unsustainable social-ecological traps. As we discuss here, all social-ecological systems are vulnerable to recent and projected changes but have sources of adaptive capacity and resilience that can sustain ecosystem services and human well-being through active ecosystem stewardship.

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Ecosystem stewardship: sustainability strategies for a rapidly changing planet

Monolithic columns in high-performance liquid chromatography.

Flow-through particles for the high-performance liquid chromatographic separation of biomolecules: perfusion chromatography.

Perfusion chromatography packing materials for proteins and peptides

Integrative (or systems biology) is a new approach to analyzing biological entities as integrated systems of genetic, genomic, protein, metabolite, cellular, and pathway events that are in flux and interdependent. Here, we demonstrate the application of intregrative biological analysis to a mammalian disease model, the apolipoprotein E3-Leiden (APO*E3) transgenic mouse. Mice selected for the study were fed a normal chow diet and sacrificed at 9 weeks of age-conditions under which they develop only mild type I and II atherosclerotic lesions. Hepatic mRNA expression analysis showed a 25% decrease in APO A1 and a 43% increase in liver fatty acid binding protein expression between transgenic and wild type control mice, while there was no change in PPAR-alpha expression. On-line high performance liquid chromatography-mass spectrometry quantitative profiling of tryptic digests of soluble liver proteins and liver lipids, coupled with principle component analysis, enabled rapid identification of early protein and metabolite markers of disease pathology. These included a 44% increase in L-FABP in transgenic animals compared to controls, as well as an increase in triglycerides and select bioactive lysophosphatidylcholine species. A correlation analysis of identified genes, proteins, and lipids was used to construct an interaction network. Taken together, these results indicate that integrative biology is a powerful tool for rapid identification of early markers and key components of pathophysiologic processes, and constitute the first application of this approach to a mammalian system.

Integrative biological analysis of the APOE*3-leiden transgenic mouse.

A competitive immunoassay for cortisol based on capillary electrophoresis (CE) and laser-induced fluorescence is described. The work involved the production of assay reagents and the development of separation conditions allowing for routine analysis of serum samples. Fluorescein-labeled cortisol was synthesized and purified. Fab fragments were produced from mouse monoclonal anticortisol antibody and purified using a POROS cation exchange chromatography column. After incubation of these reagents with serum, free and bound labeled antigen were separated by CE with high reproducibility. No prior sample cleanup of the serum samples was necessary. Serum calibration curves were established and used for the quantitation of cortisol in serum. The results demonstrate feasibility for a cortisol assay based on CE operating directly on serum samples.

Noubar B. Afeyan

Papers

Flow-through particles for the high-performance liquid chromatographic separation of biomolecules: perfusion chromatography.

Perfusion chromatography packing materials for proteins and peptides

Integrative biological analysis of the APOE*3-leiden transgenic mouse.

Capillary Electrophoresis-Based Immunoassay for Cortisol in Serum

Perfusion chromatography : an approach to purifying biomolecules