[Expression and its significance of Cyclin D1 in oral squamous cell carcinoma].

OBJECTIVE: To investigate the expression and significance of Cyclin D1 in oral squamous cell ma (OSCC). METHODS: A immunohistochemistry method, Envosion, was employed to test the manifesting Cyclin D1 in pathological slices of 50 OSCC cases and 10 normal cases, and the results was treated with statistical lysis. RESULTS: In 50 OSCC cases, Cyclin D1 mainly manifested in karyon, and a little in cytoplasm. manifesting rates of Cyclin D1 in the samples was 80.0%, which was significantly higher than the manifesting of 20.0% in normal oral mucous membrane (P < 0.01). The manifestation of Cyclin D1 was correlated with rent pathological grades, clinical phases and lymph node metastasis (P < 0.05). CONCLUSION: The abnormal tation of Cyclin D1 is closely related with the occurrence and development of OSCC. Therefore, it can subsidiary index for OSCC treatment and prognosis.

High-throughput chiral analysis of albuterol enantiomers in dog plasma using on-line sample extraction/polar organic mode chiral liquid chromatography with tandem mass spectrometric detection.

An automated chiral chromatography/tandem mass spectrometry bioanalytical method for the determination of albuterol in dog plasma was developed. The method employed on-line sample extraction using turbulent flow chromatography coupled to a Chirobiotic T column for chiral separation using a polar organic mobile phase consisting of methanol, 0.02% formic acid, and 0.1% ammonium formate. The analytes were detected by a tandem mass spectrometer operated in positive ion mode. The (S)- and (R)-isomers were resolved chromatographically with retention times of 5.1 and 5.6 min, respectively. The analytical run time was 8 min. The enantiomers did not interconvert either in mobile phase or in dog plasma at room temperature over the course of at least 2 h. The assay has a linear dynamic range from 2.5-2500 nM for both enantiomers. The lower limit of quantitation (LLOQ) was 2.5 nM for both enantiomers using 50 microL of plasma. The accuracy and precision of intraday validation were determined at five concentration levels of six replicates. The accuracy of the method for the (R)-isomer ranged from 94-103% of nominal concentrations, and the precision (%CV) ranged from 3.6-12%. The accuracy of the method for the (S)-isomer ranged from 94.5-108% of nominal concentrations, and the precision ranged from 3.2-9.3%. Interday accuracy and precision were evaluated for three days at five concentrations for one replicate. The accuracy of the method for the (R)-isomer ranged from 98-110% of nominal concentrations, and the precision ranged from 1.5-10.6%. The accuracy of the method for the (S)-isomer ranged from 96-104% of nominal concentrations, and the precision ranged from 1.5-8.7%. The combination of turbulent flow on-line sample extraction with polar organic mode chiral chromatography provided a specific, rugged, and high-throughput method for the chiral analysis of albuterol in biological fluids.

Liquid chromatographic analysis of nucleosides and their mono-, di- and triphosphates using porous graphitic carbon stationary phase coupled with electrospray mass spectrometry.

Analysis of nucleosides and nucleotides is desirable in many biological studies, but the task is analytically challenging due to the high polarity of the analytes. In this study, resolution of mixtures containing nucleosides and their mono-, di- and triphosphates was achieved using a porous graphitic carbon (PGC) stationary phase, Hypercarb, under conditions suitable for liquid chromatography/mass spectrometry (LC/MS). Different organic mobile phases and modifiers were evaluated and the separation of 16 nucleosides and nucleotides was optimized using gradient elution with a water/acetonitrile mobile phase containing ammonium acetate and diethylamine as modifiers. The ammonium acetate concentration proved to be critical for retention and diethylamine was found to improve the peak shapes of di- and triphosphates for mass spectrometric detection. A variety of silica-based columns designed for polar compound separation were also tested using optimized LC conditions and compared with results obtained with the Hypercarb column. Only the Hypercarb column provided separations suitable for accurate quantitation of mixed nucleosides and their phosphates.