Clifton K. Fagerquist

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OBJECTIVE To compare the effects of isocaloric, isonitrogenous carbohydrate nutrition vs. lipid-based total parenteral nutrition on respiratory gas exchange and intermediary metabolism in critically ill patients. DESIGN Prospective, clinical trial. SETTING Surgical intensive care unit in a major university hospital in Switzerland. PATIENTS Sixteen(More)
Six protein biomarkers from two strains of Escherichia coli O157:H7 and one non-O157:H7, nonpathogenic strain of E. coli have been identified by matrix-assisted laser desorption ionization time-of-flight-time-of-flight tandem mass spectrometry (MALDI-TOF-TOF-MS/MS) and top-down proteomics. Proteins were extracted from bacterial cell lysates, ionized by(More)
The periplasmic chaperones HdeA and HdeB are known to be important for cell survival at low pH (pH < 3) in Escherichia coli and Shigella spp. Here we investigated the roles of HdeA and HdeB in the survival of various enterohemorrhagic E. coli (EHEC) following exposure to pH 2.0. Similar to K-12 strains, the acid protections conferred by HdeA and HdeB in(More)
Curli are adhesive fimbriae of Enterobactericaeae and are involved in surface attachment, cell aggregation, and biofilm formation. We reported previously that curli-producing (C(+)) variants of E. coli O157:H7 (EcO157) were much more acid sensitive than their corresponding curli-deficient (C(-)) variants; however, this difference was not linked to the curli(More)
An acylglycerol (AG) containing four acyl chains, (12-ricinoleoylricinoleoyl)diricinoleoylglycerol (RRRR), was positively identified for the first time in a natural source in castor oil using electrospray ionization tandem mass spectrometry (ESI-MS/MS). HPLC-purified RRRR from castor oil was subjected to ion trap and high-resolution ESI-MS/MS. The precursor(More)
We have identified several protein biomarkers of three Campylobacter jejuni strains (RM1221, RM1859, and RM3782) by proteomic techniques. The protein biomarkers identified are prominently observed in the time-of-flight mass spectra (TOF MS) of bacterial cell lysate supernatants ionized by matrix-assisted laser desorption/ionization (MALDI). The protein(More)
We have developed web-based software for the rapid identification of protein biomarkers of bacterial microorganisms. Proteins from bacterial cell lysates were ionized by matrix-assisted laser desorption ionization (MALDI), mass isolated, and fragmented using a tandem time of flight (TOF-TOF) mass spectrometer. The sequence-specific fragment ions generated(More)
A simple, rapid, rugged, sensitive, and specific method for the confirmation and quantitation of 10 beta-lactam antibiotics in fortified and incurred bovine kidney tissue has been developed. The method uses a simple solvent extraction, dispersive solid-phase extraction (dispersive-SPE) cleanup, and liquid chromatography-tandem mass spectrometry (LC/MS/MS)(More)
We report covalent attachment via a thiol ester linkage of 3,5-dimethoxy-4-hydroxycinnamic acid (sinapinic acid or SA) to cysteine-containing protein biomarkers from bacterial cell lysates of E. coli analyzed by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry when using SA as the matrix. Evidence to support this conclusion is the(More)
Eleven beta-lactam antibiotics were analyzed in fortified and incurred beef kidney tissue using high-performance liquid chromatography/electrospray ionization/selective reaction monitoring-ion trap tandem mass spectrometry (LC/ESI-SRM-MS(n)). The analytes included: deacetylcephapirin, amoxicillin, cephapirin, desfuroylceftiofur cysteine disulfide (DCCD, a(More)