No abstract

Oral squamous cell carcinoma (OSCC) is the fifth common cause of cancer mortality in Taiwan with high incidence and recurrence and needs new therapeutic strategies. In this study, ursolic acid (UA), a triterpenoid, was examined the antitumor potency in OSCC cells. Our results showed that UA inhibited the proliferation of OSCC cells in a dose‐ and time‐dependent manner in both Ca922 and SCC2095 oral cancer cells. UA induced caspase‐dependent apoptosis accompanied with the modulation of various biological biomarkers including downregulating Akt/mTOR/NF‐κB signaling, ERK, and p38. In addition, UA inhibited angiogenesis as evidenced by abrogation of migration/invasion and blocking MMP‐2 secretion in Ca922 cells. Interestingly, UA induced autophagy in OSCC cells, as manifested by LC3B‐II conversion and increased p62 expression and accumulation of autophagosomes. Inhibition by autophagy inhibitor enhanced UA‐mediated apoptosis in Ca922 cells. The experiment provides a rationale for using triterpenoid in the treatment of OSCC.

We have extracted ten phthalate esters (C1 to C8) using six different micro-scale methods for extraction, and then separated them by capillary liquid chromatography coupled to UV detection. The methods included liquid-liquid extraction, ultrasonic-assisted extraction, microwave-assisted extraction, dispersive liquid-liquidmicroextraction, dispersive liquid-liquid microextraction solidification of floating organic droplets, and cloud point extraction. The linear range of the analytes is from 0.5 to 50 μg mL −1 , and the detection limits range from 0.02 to~0.17 μg mL −1 . The precision and accuracy of all intra-and inter-day analyses are <5.5%. We find that dispersive liquid-liquid microextraction solidification of floating organic droplet (DLLME-SFO) is the best method for quantification of most phthalate esters in water samples and cosmetics because of its low limit of detection and high extraction efficiencies.

A simple and sensitive liquid chromatographic method is described for the determination of amikacin in human plasma. The amikacin is derivatized with 1-naphthyl isothiocyanate (NITC) at 70 ~ derivatization, a methylamine acetonitrile solution is added to the reaction mixture to eliminate excess derivatizing agent. The resulting derivative was analysed by HPLC on a LiChroCART RP-Cls column with water-acetonitrile (57:43, v/v) mobile phase and detection at 230 nm. Parameters affecting derivatization of amikacin, including reaction temperature, reaction time and amount of derivatizing agent, were investigated. The linear range for the determination of amikacin in spiked plasma was over 10-52 nmol mL 1; the detection limit (signal-to-noise ratio = 3; injection volume, IOI~L) was ca. 1 nmol mL 1. The relative standard deviation was < 2.37% for intra-day assay (n = 6), 5.80% for inter-day assay (n = 6) and relative recoverywas > 91%.

No abstract