Analysis of dipalmitoyl phosphatidylcholine in amniotic fluid by high-performance liquid chromatography

A novel method for the determination of dipalmitoyl phosphatidylcholine (DPPC) in amniotic fluid by high-performance liquid chromatography (HPLC) is described. Aliquots of 50 μl of amniotic fluid were hydrolyzed with phospholipase C from Bacillus cereus and the resulting dipalmitoylglycerol analyzed by HPLC. Run-to-run and day-to-day precision for DPPC analysis were 4.2 and 6.1%, respectively, and analysis time was 10 min. Recoveries for DPPC ranged between 92 and 98%. In summarizing, this method provides a high precision and fast turnaround time means for the analysis of DPPC in amniotic fluid.     

4-Quinolone antibiotics: positive genotoxic screening tests despite an apparent lack of mutation induction

The effects of different 4-quinolone antibiotic derivatives (4-Qs) in a number of short-term tests commonly employed for the evaluation of genetic toxicity were studied. Incorporation of [3H]thymidine into mitogen-stimulated peripheral blood lymphocytes was strongly enhanced at a low concentration (1.56 micrograms/ml) for most of the tested 4-Qs, whereas DNA strand breakage in lymphoblastoid cells was evident only for ciprofloxacin (10 micrograms/ml and upwards), ofloxacin (80 micrograms/ml) and norfloxacin (160 micrograms/ml). Ciprofloxacin induced a significant amount of unscheduled DNA synthesis, but was found to be negative in a shuttle vector plasmid mutation test. Ciprofloxacin (80 micrograms/ml) did not inhibit enzymes involved in the early steps of pyrimidine biosynthesis. Cell growth was slightly depressed at a concentration of 20 micrograms/ml, becoming marked at 80 micrograms/ml. In conclusion, this study seeks to contribute to an improved evaluation of genotoxic screening test data, by focusing attention on the conflicting effects imposed by the 4-Qs on a battery of such tests.