Determination of free N-acetyl neuraminic acid by ultrafiltration and liquid chromatography in the serum of normal and cancer patients

1995 ◽  
Vol 306 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Aldo Laganà ◽  
Aldo Marino ◽  
Giovanna Fago ◽  
Beatriz Pardo Martinez
1987 ◽  
Vol 73 (3) ◽  
pp. 289-294 ◽  
Author(s):  
Marco Lorenzi ◽  
Daniela Vannoni ◽  
Roberto Leoncini ◽  
Ranieri Caldarone ◽  
Enrico Marinello

Plasma levels and urinary excretion of oxypurines – hypoxanthine and xanthine – were evaluated by reverse-phase high-pressure liquid chromatography in 13 patients affected by gastric tumors and in 19 colorectal tumor-bearing patients. Preliminary results indicate higher values of urinary xanthine and an increase in the xanthine/hypoxanthine ratio in cancer patients. The increase was not generalized to all subjects, and did not appear related either to the stage of the disease or to CEA values. The limits within which the determination of urinary oxypurines can be employed as a tumor marker are discussed.


1999 ◽  
Vol 266 (2) ◽  
pp. 216-221 ◽  
Author(s):  
Peter de Bruijn ◽  
Jaap Verweij ◽  
Walter J. Loos ◽  
Herman J. Kolker ◽  
André S.T. Planting ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Shouhong Gao ◽  
Zhengbo Tao ◽  
Jingya Zhou ◽  
Zhipeng Wang ◽  
Yunlei Yun ◽  
...  

Therapeutic drug monitoring for anticancer drugs could timely reflect in vivo drug exposure, and it was a powerful tool for adjusting and maintaining drug concentration into a reasonable range, so that an enhanced efficacy and declined adverse reactions could be achieved. A liquid chromatography-tandem mass spectrometry method had been developed and fully validated for simultaneous determination of paclitaxel, docetaxel, vinblastine, vinorelbine, pemetrexed, carboplatin, etoposide, cyclophosphamide, ifosfamide, gemcitabine, irinotecan, and SN-38 (an active metabolite of irinotecan) in human plasma from cancer patients after intravenous drip of chemotherapy drugs. One-step solid-phase extraction was successfully applied using an Ostro sample preparation 96-well plate for plasma samples pretreated with acetonitrile containing 0.1% formic acid. Chromatographic separation was achieved on an Atlantis T3-C18 column (2.1 × 100 mm, 3.0 μm) with gradient elution using a mobile phase consisting of acetonitrile and 10 mM ammonium acetate plus 0.1% formic acid in water, and the flow rate was 0.25 mL/min. The Agilent G6410A triple quadrupole liquid chromatography-mass spectrometry system was operated under the multiple reaction monitoring mode with an electrospray ionization in the positive mode. Linear range was 25.0–2500.0 ng for paclitaxel, 10.0–1000.0 ng for docetaxel and SN-38, 100.0–10000.0 ng for vinorelbine and pemetrexed, 10.0–10000.0 ng for vinblastine and irinotecan, 1.0–1000.0 ng for cyclophosphamide and ifosfamide, 50.0–5000.0 ng for carboplatin, etoposide, and gemcitabine. Linearity coefficients of correlation were >0.99 for all analytes. The intraday and interday accuracy and precision of the method were within ±15.0% and less than 15%. The mean recovery and matrix effect as well as stability of all the analytes ranged from 56.2% to 98.9% and 85.2% to 101.3% as well as within ±15.0%. This robust and efficient method was successfully applied to implement therapeutic drug monitoring for cancer patients in clinical application.


Author(s):  
Hong Ngoc Nguyen Thi ◽  
Thanh Hoa Mac Thi ◽  
Mai Hoa Duong Thi ◽  
Son Tran Hung ◽  
Khanh Cao Cong ◽  
...  

Simultaneous determination of sialic acids (N-acetyl neuraminic acid - NANA and N-glycolyl neuraminic acid - NGNA) in dietary supplement matrices by liquid chromatography tandem-mass spectrometry (LC-MS/MS) had been developed. Sialic acids were separated by using a C18 column (75 mm x 3.9 mm, 2.5 µm) and isocratic mobile phase of acid formic 0.1 %: acetonitrile (80:20, v/v). Sialic acids were totally hydrolyzed by formic acid 1M at 80oC in 2 hours before being analyzed by LC-MS/MS. It was proved that the method with the linearity range of 0.04 - 4.25 µg/ml had highly specificity, selectivity, repeatability, and recovery rate, that well satisfied AOAC requirements. The method has been applied to detect sialic acids in commercial dietary supplements.


Sign in / Sign up

Export Citation Format

Share Document