Dynamic coating capillary electrophoresis for separation of humic acid using mixture solution of non-ionic polymers both as coating agent and separation medium.

A simple, rapid, and precise dynamic coating capillary electrophoretic separation method for water-soluble humic substances is proposed. An aqueous solution containing hydroxyethyl cellulose (HEC), polyethylene glycol (PEG), and pH buffer component was employed for both the dynamic coating agent and the separation medium. The procedure for the coating of the capillary inner wall was simply filling the buffered polymer mixture solution into the capillary that had been treated with 1 M aqueous HCl solution. The solution for the capillary coating was directly used as the electrophoretic buffer solution for CE separation. Excellent performance for the separation of humic acid was obtained using the solution containing 0.5% (w/v) HEC, 1.0% (w/v) PEG 10000, and 0.1% (w/v) PEG 8000000. Excellent reproducibility and durability were obtained even at slightly alkaline conditions at pH levels above 8. The separation of 0.1 - 2 kbp of DNA ladder by the proposed method showed was also achieved.

Capillary electrophoretic separation of humic substances using hydroxyethyl cellulose as a buffer additive and its application to characterization of humic substances in a river water sample.

We have developed a concise tool for the investigation of the transition of humic substances in environmental water. The separation of water-soluble humic substances was achieved rapidly and effectively by capillary electrophoresis using a polyacrylamide-coated capillary and a phosphate electrophoretic buffer solution (pH 7.0) containing hydroxyethyl cellulose. The separation mechanism was assessed using the ultrafiltration technique. The effect of the complexation of humic substances with metal ions was studied by using the proposed method. When Fe(III) ions or EDTA was added to the sample solution of fulvic acid, a distinct change in the electropherogram pattern based on the conformational change of fulvic acid was observed. The successful application of the proposed method to the characterization of humic substances in a river water sample was also demonstrated.

Comparison of pharmacodynamics between carvedilol and metoprolol in rats with isoproterenol-induced cardiac hypertrophy: effects of carvedilol enantiomers.

A recent clinical study has shown that carvedilol has a significantly more favorable effect than metoprolol on survival rate in patients with heart failure. This may be due to actions of carvedilol such as beta(2)-adrenoceptor blockade, alpha-adrenergic receptor blockade and other properties such as anti-oxidant effects that are not yet fully understood. We compared the effects of racemic carvedilol, metoprolol and carvedilol enantiomers on cardiac hypertrophy at similar heart rate in rats with isoproterenol-induced cardiac hypertrophy. Continuous administration of isoproterenol for 2 weeks produced heart failure, which is characterized by an increased heart rate, cardiac hypertrophy and downregulation of beta-adrenoceptors. The doses of racemic carvedilol and metoprolol were adjusted to obtain a similar heart rate in rats with isoproterenol-induced cardiac hypertrophy. The reduction of left ventricular weight and improvement of cAMP production induced by carvedilol were superior to those induced by metoprolol. Although heart rate, blood pressure and cAMP production were not affected by R-carvedilol, left ventricular weight was significantly reduced as a result of alpha-adrenoceptor blockade. The improvement of cAMP production by S-carvedilol was significantly higher than that induced by coadministration of R-carvedilol and metoprolol, suggesting that beta(2)-adrenoceptor blockade partly contributed to the improvement of signal transduction in rats with isoproterenol-induced cardiac hypertrophy. This study has demonstrated that the effects of carvedilol on cAMP production and cardiac hypertrophy in rats with isoproterenol-induced cardiac hypertrophy are superior to those induced by metoprolol at a similar heart rate.