A new method is presented for quantifying proteomic and metabolomic profile data by liquid chromatography−mass spectrometry (LC−MS) with electrospray ionization. This biotechnology provides differential expression measurements and enables the discovery of biological markers (biomarkers). Work presented here uses human serum but is applicable to any fluid or tissue. The approach relies on linearity of signal versus molecular concentration and reproducibility of sample processing. There is no use of isotopic labeling or chemically similar standard materials. Linear standard curves are reported for a variety of compounds introduced into human serum. As a measure of analytical reproducibility for proteome and metabolome sampling, median coefficients of variation of 25.7 and 23.8%, respectively, were determined for ∼3400 molecular ions (not counting their numerous isotopes) from 25 independently processed human serum samples, corresponding to a total of 85 000 individual molecular ion measurements.

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Quantification of proteins and metabolites by mass spectrometry without isotopic labeling or spiked standards

An improved procedure for the methylation analysis of oligosaccharides and polysaccharides

Using Cellosolve as a solubilizing additive, up to 5.84 ml of aqueous bicarbonate solutions and essentially equivalent amounts of urine and plasma containing carbon-14- sodium carbonate can be assayed by liquid scintillation counting techniques. Of particular significance is the realization of determining carbon-14 activity with relatively high efficiency in the important biological fluids. (auth)

Determination of carbon-14 in aqueous bicarbonate solutions by liquid scintillation counting techniques. application to biological fluids

The suitability of urethane anesthesia for physiopharmacological investigations is reviewed. Total dose administered and route of administration are recognized as factors having a great influence on both resting parameters and biological responses to drugs. A peculiar characteristic of urethane is represented by its ability to induce a surgical plane of anesthesia without affecting neurotransmission in various subcortical areas and the peripheral nervous system. This makes urethane a suitable general anesthetic for studying neural function in both central and peripheral nervous systems and accounts for the preservation of a number of reflex responses in urethane-anesthetized animals.

Suitability of urethane anesthesia for physiopharmacological investigations in various systems. Part 1: General considerations.

(1980). Chlorinated Phenols: Occurrence, Toxicity, Metabolism, And Environmental Impact. CRC Critical Reviews in Toxicology: Vol. 7, No. 1, pp. 1-35.

Chlorinated Phenols: Occurrence, Toxicity, Metabolism, And Environmental Impact

A Comparative Study of Iodine and Potassium Perchlorate Metabolism in the Laying Hen 1. Incorporation of I-131 in Chicken Ova

A series of experiments designed to determine the distribution of N15 in the tissues and excretions of the rat following the intraperitoneal administration of nitrogen-labeled urethan is described and the results are reported. The concentration of N15 was generally higher in the bone marrow than in other tissues. The liver, gastrointestinal, spleen, and kidney proteins were found to contain greater concentrations than the brain, heart, lung, testes, skin, and muscle proteins. The amide nitrogen is excreted by way of the urine and feces. It is excreted in the urine partly as urea and partly as ammonium ion nitrogen.

The distribution of N15 in Rat Tissues Following the Intraperitoneal Administration of Nitrogen-Labeled Urethan

A method is presented for the quantitative determination of sulfonamides based on the differences in their distribution coefficients. It appears to be suitable for the assay of sulfonamides and their derivatives in pure form as well as in pharmaceutical preparations. The procedure consists essentially in the adsorption of the sulfonamides from an aqueous acidic solution on a column of ion-exchange resin. Finally, the individual sulfonamides are chromatographically eluted and measured quantitatively using the isotope dilution technique.

John E. Christian

Papers

A Comparative Study of Iodine and Potassium Perchlorate Metabolism in the Laying Hen 1. Incorporation of I-131 in Chicken Ova

The distribution of N15 in Rat Tissues Following the Intraperitoneal Administration of Nitrogen-Labeled Urethan

Sulfonamide separations based on ion‐exchange chromatography in combination with radioactive techniques

Metabolism of the Plant Growth Regulator 2,3,5-Triiodobenzoic Acid in Soybeans

Nuclear In Vitro Method of Continuously Measuring Dissolution Rates