After the recent publication in the Journal of Biophysical Chemistry entitled “Retracted HIV Study Provides New Information about the Status of the in Vitro Inhibition of DNA Replication by Back-bone Methylation”, i...After the recent publication in the Journal of Biophysical Chemistry entitled “Retracted HIV Study Provides New Information about the Status of the in Vitro Inhibition of DNA Replication by Back-bone Methylation”, it is of importance to review the results of Buck’s group on the synthesis and conformation analyses of phosphate-methylated RNAs in order to afford information on the absence of a further investigation with regard to this de facto acceptable approach. In fact these compounds belong to the very first group of RNAs with a modified neutral backbone by phosphatemethylation. In contrast to the corresponding phosphate-methylated DNAs with a frozen B-conformation, the phosphate-methylated RNAs show an A-conformation. The latter is a prerequisite for duplex formation with (complementary) (natural) RNA. A number of experiments support this fundamental statement. After the HIV study was retracted, the overall results concerning the phosphate-methylated RNAs were published without mentioning Buck’s initial proof of concept and his contributions. Generally, the (modified) dimer RNAs and DNAs possess a number of specific biophysical properties. A novel explanation is given for conflicting structural determinations.展开更多
Benzo(a)pyrene metabolism in human placental microsomes fromsmokers was studied.Benzo(a)pyrene metabolites were separatedusing high pressure liquid chromatographic technique. Reactionof benzo(a)pyrene with microsomal ...Benzo(a)pyrene metabolism in human placental microsomes fromsmokers was studied.Benzo(a)pyrene metabolites were separatedusing high pressure liquid chromatographic technique. Reactionof benzo(a)pyrene with microsomal fraction of placenta fromindividuals who smoke cigarette during pregnency yields 7。展开更多
目的运用meta分析方法系统评价补肾方剂治疗男性不育症患者精子DNA损伤(SDF)的有效性和安全性。方法从中国知网、维普、万方、PubMed、Cochrane Library、Embase、Web of Science数据库中检索补肾方剂改善SDF的随机对照试验(RCT)研究,...目的运用meta分析方法系统评价补肾方剂治疗男性不育症患者精子DNA损伤(SDF)的有效性和安全性。方法从中国知网、维普、万方、PubMed、Cochrane Library、Embase、Web of Science数据库中检索补肾方剂改善SDF的随机对照试验(RCT)研究,对文献进行方法学质量评价,运用RevMan5.3.5软件进行meta分析,并对结局指标进行GRADE质量分级。结果共纳入17项RCT研究,涉及2164例男性患者。与西医常规治疗相比,补肾方剂能够显著改善男性不育症患者DNA碎片指数(DFI)(MD=-6.50,95%CI:-7.88~-5.11,P<0.01),提高配偶妊娠率(RR=2.11,95%CI:1.12~4.00,P=0.87)、精子总活率(MD=5.56,95%CI:4.39~6.74,P<0.01)、前向运动精子百分率(MD=6.82,95%CI:5.62~8.03,P<0.01)、精子浓度(MD=6.51,95%CI:3.81~9.21,P<0.01)和正常形态精子百分率(MD=1.26,95%CI:0.45~2.06,P<0.01),且补肾方剂不会增加不良反应的发生。结论低到中等质量证据表明,与西医常规治疗相比,补肾方剂在改善男性不育症患者DFI、精液参数、配偶妊娠率等方面具有一定优势,且安全性较好。展开更多
文摘After the recent publication in the Journal of Biophysical Chemistry entitled “Retracted HIV Study Provides New Information about the Status of the in Vitro Inhibition of DNA Replication by Back-bone Methylation”, it is of importance to review the results of Buck’s group on the synthesis and conformation analyses of phosphate-methylated RNAs in order to afford information on the absence of a further investigation with regard to this de facto acceptable approach. In fact these compounds belong to the very first group of RNAs with a modified neutral backbone by phosphatemethylation. In contrast to the corresponding phosphate-methylated DNAs with a frozen B-conformation, the phosphate-methylated RNAs show an A-conformation. The latter is a prerequisite for duplex formation with (complementary) (natural) RNA. A number of experiments support this fundamental statement. After the HIV study was retracted, the overall results concerning the phosphate-methylated RNAs were published without mentioning Buck’s initial proof of concept and his contributions. Generally, the (modified) dimer RNAs and DNAs possess a number of specific biophysical properties. A novel explanation is given for conflicting structural determinations.
文摘Benzo(a)pyrene metabolism in human placental microsomes fromsmokers was studied.Benzo(a)pyrene metabolites were separatedusing high pressure liquid chromatographic technique. Reactionof benzo(a)pyrene with microsomal fraction of placenta fromindividuals who smoke cigarette during pregnency yields 7。
文摘目的运用meta分析方法系统评价补肾方剂治疗男性不育症患者精子DNA损伤(SDF)的有效性和安全性。方法从中国知网、维普、万方、PubMed、Cochrane Library、Embase、Web of Science数据库中检索补肾方剂改善SDF的随机对照试验(RCT)研究,对文献进行方法学质量评价,运用RevMan5.3.5软件进行meta分析,并对结局指标进行GRADE质量分级。结果共纳入17项RCT研究,涉及2164例男性患者。与西医常规治疗相比,补肾方剂能够显著改善男性不育症患者DNA碎片指数(DFI)(MD=-6.50,95%CI:-7.88~-5.11,P<0.01),提高配偶妊娠率(RR=2.11,95%CI:1.12~4.00,P=0.87)、精子总活率(MD=5.56,95%CI:4.39~6.74,P<0.01)、前向运动精子百分率(MD=6.82,95%CI:5.62~8.03,P<0.01)、精子浓度(MD=6.51,95%CI:3.81~9.21,P<0.01)和正常形态精子百分率(MD=1.26,95%CI:0.45~2.06,P<0.01),且补肾方剂不会增加不良反应的发生。结论低到中等质量证据表明,与西医常规治疗相比,补肾方剂在改善男性不育症患者DFI、精液参数、配偶妊娠率等方面具有一定优势,且安全性较好。
