A rapid and simple high-performance liquid chromatography-ultraviolet method was developed for the separation and quantification of 15 sulfonamides (SAs) in foods of animal origin without the need of clean-up procedure. A mixture of acetonitrile-formic acid-ammonium acetate-water was used as the mobile phase to separate 15 SAs on a C18 column with gradient. The selected SAs were separated completely from the matrix mixture based on different retention behaviors at different concentration of acetonitrile. The effects of the additive of formic acid and ammonium acetate in mobile phases on the separation of SAs were also investigated. The additive can greatly improve the resolution between SAs and impurities, so that the SAs can be quantified directly under the optimized chromatographic condition the sample preparation which does not need extra sample clean-up procedure. Complete baseline separation of 15 SAs was achieved in <40 min, the linear range is 0.01-130 μg/mL with a correlation coefficient R2-value > 0.999. Excellent method reproducibility was found by intra- and inter-day precisions with the relative standard deviation <9.5%. The detection limit was <11.0 ng/mL and it can be used for routine screening of the SA residues in foods of animal origin.
A Tempol compound with an amine group (4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl, NH-Tempol) was cross-linked to hemoglobin in a one-step polymerization reaction to produce a novel hemoglobin-based oxygen carrier (HBOC) designated PolyHb-Tempol. The reaction parameters, including the reaction time, pH, temperature, and ratio of reactants, were optimized, and the physiochemical properties of the resulting product were characterized. PolyHb-Tempol didn't show any toxicity towards endothelial cells. Furthermore, from observations of cell morphology and viability, PolyHb-Tempol showed a significant ability to inhibit or eliminate oxidative stress induced by superoxide free radicals. These results suggest that PolyHb-Tempol may potentially be suitable as an HBOC.
The effects of polymerized porcine hemoglobin (pPolyHb) on hemodynamic stability and maintenance of mesenteric microvascular function were explored in a rat model of hemorrhagic shock (HS). Following controlled hemorrhage, rats were infused with equal volumes of either pPolyHb, hetastarch (HES), or red blood cell (RBC). The results showed that pPolyHb was superior to HES and RBC in restoring hemodynamic stability and reversing anaerobic metabolism. We observed a reduction in the diameter of mesenteric microvasculature after HS. Resuscitation with pPolyHb and RBC was able to restore the diameters of the venules and arterioles, whereas HES failed to restore the diameters during the observation period.
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