Detection of strand breaks of DNA in human early chorionic villus cells induced by diagnostic ultrasound using 32P-labeled Alu hybridization / 西安交通大学学报·英文版

ABSTRACT

Objective: To explore if strand breaks of DNA in human early chorionic villus cells in uterus were induced by diagnostic ultrasound and to evaluate the method used for detection of single-stranded breaks and double-stranded breaks in human DNA. Methods: 60 Normal pregnant women aged 20-30, who underwent artificial abortion during 6-8 weeks of gestation, were randomly divided into 2 experimental groups All 30 cases were exposed to diagnostic ultrasound in uterus for 10 minutes, and 24 hours later chorionic villi were extracted; the other 30 cases were taken as the control group. Single-stranded DNA and double-stranded DNA in villus cells in all cases were isolated by the alkaline unwinding combined with hydroxylapatite chromatography, and were quantitatively detected using32 P-labeled Alu probe for dot-blotting hybridization. Results: There was no significant difference in quantity and percentage in single-stranded DNA and double-stranded DNA between 2 groups (P>0. 05). 32P-Alu probe could only hybridize with human DNA, and could detect DNA isolated from as few as 2.5 × 103 chorionic villus cells and 0.45 ng DNA in human leukocytes. Conclusion: The results suggested that there were no DNA strand damages in human chorionic villus cells when the uterus was exposed to diagnostic ultrasound for 10 minutes. The method, 32P-Alu probe for dot-blotting hybridization, was even more specific, sensitive and accurate than conventional approaches.