[Study of using shattering extraction with solvent to extract ingredient of three kinds of traditional Chinese medicine].

OBJECTIVE: To prove if it is possible for using the shattering extraction with solvent to extract ingredients of traditional Chinese medicine. METHOD: The shattering extraction with solvent, the refluxing extraction and the ultrasonic extraction were used to extract paeoniflorin from Radix Paeoniae rubra, and to extract baicalein from Radix Scutellariae, and to extract chlorogenic acid from Flos lonicerae japonicae respectively, using ingredient content and extract yield as the measuring indexes. RESULT: The content of each every ingredient obviously higher by using shattering extraction with solvent than using refluxing extraction or the ultrasonic extraction. CONCLUSION: The shattering extraction with solvent is a high efficiency, simple and quick extraction. It may be used to extract the ingredient of three kinds of traditional Chinese medicine.

New aspects of HERG K⁺ channel function depending upon cardiac spatial heterogeneity.

HERG K(+) channel, the genetic counterpart of rapid delayed rectifier K(+) current in cardiac cells, is responsible for many cases of inherited and drug-induced long QT syndromes. HERG has unusual biophysical properties distinct from those of other K(+) channels. While the conventional pulse protocols in patch-clamp studies have helped us elucidate these properties, their limitations in assessing HERG function have also been progressively noticed. We employed AP-clamp techniques using physiological action potential waveforms recorded from various regions of canine heart to study HERG function in HEK293 cells and identified several novel aspects of HERG function. We showed that under AP-clamp IHERG increased gradually with membrane repolarization, peaked at potentials around 20-30 mV more negative than revealed by pulse protocols and at action potential duration (APD) to 60%-70% full repolarization, and fell rapidly at the terminal phase of repolarization. We found that the rising phase of IHERG was conferred by removal of inactivation and the decaying phase resulted from a fall in driving force, which were all determined by the rate of membrane repolarization. We identified regional heterogeneity and transmural gradient of IHERG when quantified with the area covered by IHERG trace. In addition, we observed regional and transmural differences of IHERG in response to dofetilide blockade. Finally, we characterized the influence of HERG function by selective inhibition of other ion currents. Based on our results, we conclude that the distinct biophysical properties of HERG reported by AP-clamp confer its unique function in cardiac repolarization thereby in antiarrhythmia and arrhythmogenesis.

MicroRNA expression in the embryonic mouse inner ear.

Although microRNA (miRNA) is expressed extensively in the postnatal mouse inner ear, its expression in the sensory epithelium during embryogenesis has not been well characterized. We investigated miRNA expression at E13.5 and E16.5 by microarray analysis, quantitative real-time-PCR, and in-situ hybridization. MiRNA-182, miRNA-140, miRNA-200c, and others showed distinct temporal and spatial expression patterns. MiRNA-194, whose expression in zebrafish seems to play an important role in the differentiation of the intestinal epithelium, was also expressed in the spiral ganglia of the mouse inner ear, where it may play a similar role in neuronal differentiation. Our results indicate that miRNAs are widely expressed in the developing inner ear, with more species recruited as hair cells differentiate, suggesting an important developmental role.