ABSTRACT
Objective: In order to correctly identify the different germplasm resources of Gastrodia elata and gain the excellent germplasm resources, SRAP molecular marker was used to analyze the genetic diversity of G. elata. Methods: G. elata was collected from seven different areas, which included 24 smaples of G. elata f. elata, G. elata f. g1auca and G. elata f. viridis, the DNA figerprint of G. elata was constructed with SRAP molecular marker, and the genetic diversity was analyzed. Results: Six huandred Thirty-seven belts were amplified by 33 primers pairs, and the polymorphic percentage was 73.16%. The range of genetic similarity coefficient was 0.404 0-0.908 0, the genetic similarity coefficient among G. elata f. elata was in the range of 0.906 6-0.996 4, and those of G. elata f. g1auca, G. elata f. viridis, and hybrid was in the range of 0.410 4-0.999 6, 0.541 0-0.950 4 and 0.578 2, respectively. They showed small genetic differences. The analysis of molecular variance showed higher percentages of genetic variation within population than those among populations in all species. Populations showed higher genetic structure (FST = 0.33, P < 0.05). In addition, artificial cultivation had influence to the genetic differentiation, but not significantly. So in terms of different cultivation conditions so far had no significant impact on the genetic differentiation of G. elata. Mantel's test has been used to detect the correlation between genetic distance and geographic distance of all sorts of germplasm resources, the result had no significant correlation, and due to the limited number of samples, the result is not representative. Conclusion: SRAP molecular marker method can more effectively reflect the genetic polymorphisms of G. elata. Compared with other two phenotypes, G. elata f. elata is more conservative and has lower genetic diversity. The other two variants have higher genetic diversity.
ABSTRACT
Torsade de pointes is a life-threatening, polymorphic ventricular tachycardia associated with prolongation of the QTc interval. Although torsade de pointes is found in many clinical settings, it is mostly drug induced. Similar problems have been described with nonsedating H1-selective antihistamines like terfenadine and astemizole. The increased risks of both H1-antihistamines were associated with exposure to supratherapeutic doses or concomitant exposure to the cytochrome P-450 inhibitors, ketoconazole, erythromycin and cimetidine. We report a 51-year-old woman with torsade de pointes and a long QTc interval caused by the combined use of terfenadine and itraconazole. After discontinuation of these drugs and treatments with electrical cardioversion and magnesium sulfate, torsade de pointes and prolonged QTc interval were no longer observed and she was discharged in good condition with a normal ECG. In conclusion, physicians should be aware that terfenadine and astemizole can cause torsade de pointes in rare cases.