Clinical pathology testing of rodents is often challenging due to insufficient sample volume. One solution in clinical veterinary and exploratory research environments is dilution of samples prior to analysis. However, published information on the impact of preanalytical sample dilution on rodent biochemical data is incomplete. The objective of this study was to evaluate the effects of preanaly...

We developed an isotope dilution mass spectrometric cholesterol method with [25,26,27-13C]cholesterol as internal standard and a benchtop gas chromatograph/mass spectrometer (GC/MS) that is much easier and less time consuming than previously described Reference and Definitive Methods for cholesterol. The internal standard, cholesterol standards, and unknown specimen are delivered volumetrically...

As the limiting substrate is altered, a microorganism’s internal structure is also altered by invoking different metabolic pathways for the utilization of the limiting substrate. Transitions between pathways are moderated by the processes of metabolic regulation and are observed under steady-state and transient conditions. Under nitrogen-limited steady-state conditions, the effects of overflow ...

In most species, once formed in the testis, spermatozoa are bathed in a fluid where they remained immobile and with a very low level of metabolism. This immotile status is understandable in view of the need to preserve the sperm energy reserve and to decrease the risk of alteration to membranes, internal structures and biochemical compounds by endogenous oxidizing agents produced by mitochondri...

BACKGROUND Isotope dilution LC-MS/MS methods used in the clinical laboratory typically involve multi-point external calibration in each analytical series. Our aim was to test the hypothesis that determination of target analyte concentrations directly derived from the relation of the target analyte peak area to the peak area of a corresponding stable isotope labelled internal standard compound [...

Many proteins (more than one third) contain metal ions either within their own structures or bound to some of their active sites. These metals are involved in numerous biological processes and therefore, the quantification of metalloproteins that can serve as clinical biomarkers is of great interest. With this aim, the development of analytical strategies that permit individual (targeted) prote...

Until now, limited observational data have suggested that the juxtaposition of trees with respect to place where a GPS position fix is collected may affect static horizontal position accuracy of that determined position. Our goal was to assess GPS accuracy with respect to the spatial arrangement of nearby trees, and determine whether correlations existed or whether trends were evident. Therefor...