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The circadian glucocorticoid rhythm provides important information on the functioning of the hypothalamic-pituitary-adrenal axis in individuals. Frequent repeated blood sampling can limit the kinds of studies conducted on this rhythm, particularly in small laboratory rodents that have limited blood volumes and are easily stressed by handling. We developed an extraction and assay protocol to measure fecal corticosterone metabolites in repeated samples collected from undisturbed male and female adult Sprague–Dawley rats. This fecal measure provides a non-invasive method to assess changes in corticosterone within a single animal over time, with sufficient temporal acuity to quantify several characteristics of the circadian rhythm: e.g. the nadir, acrophase, and asymmetry (saw-tooth) of the rhythm. Males excreted more immunoreactive fecal corticoids than did females. Across the estrous cycle, females produced more fecal corticoids on proestrus (the day of the preovulatory luteinizing hormone surge) than during estrus or metestrus. These results establish a baseline from which to study environmental, psychological, and physiological disturbances of the circadian corticosterone rhythm within individual rats.

A simple microadsorption technique is described to remove detergent additives from oligosaccharide samples before their mass spectrometric analysis. The described methodology has been validated with submicrogram quantities of contaminated glycoproteins. This procedure is applicable to investigating minute quantities of glycans in both the positive‐ and negative‐ion mode of matrix‐assisted laser desorption/ionization mass spectrometry. Copyright © 2000 John Wiley & Sons, Ltd.

A simple microadsorption technique is described to remove detergent additives from oligosaccharide samples before their mass spectrometric analysis. The described methodology has been validated with submicrogram quantities of contaminated glycoproteins. This procedure is applicable to investigating minute quantities of glycans in both the positive- and negative-ion mode of matrix-assisted laser desorption/ionization mass spectrometry. Copyright © 2000 John Wiley & Sons, Ltd.

A minor component of the major urinary protein complex of the house mouse was chromatographically isolated and ascertained to be a previously suspected glycoprotein. Using highly sensitive mass-spectrometric techniques for sequencing and linkage analysis, the N-linked oligosaccharides of this glycoprotein were characterized. They were determined to be of the complex type with a wide heterogeneity. The heterogeneity was due to both the degree of sialylation and the presence of galactose residues in either beta(1-3) or beta(1-4) linkages. The biantennary structures were the most pronounced glycans, while tri- and tetraantennary entities were minor.

The detailed structures of N- glycans derived from bile salt-stimulated lipase (BSSL) found in human milk were determined by combining exoglycosidase digestion with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The N- glycan structures were conclusively determined in terms of complexity and degree of fucosylation. Ion-exchange chromatography with pulsed amperometric detection, together with mass-spectral analysis of the esterified N- glycans, indicated the presence of monosialylated structures. The molecular mass profile of esterified N- glycans present in BSSL further permitted the more detailed studies through collision-induced dissociation (CID) and sequential exoglycosidase cleavages. The N- glycan structures were elucidated to be complex/dibranched, fucosylated/complex/dibranched, monosialylated/complex/dibranched, and monosialylated/fucosylated/dibranched entities.

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