Inhibition of the activity of restriction endonucleases by spermidine and spermine

AbstractPhysiological concentrations (0.5–2.0 mM) of spermidine and spermine were observed to inhibit the digestion in vitro of plasmid pJDB 207 by the restriction endonucleases BamHI (EC 3.1.23.6), EcoRI (EC 3.2.23.13), HindIII (EC 3.1.23.20), HpaI (EC 3.1.23.23) and PstI (EC 3.1.23.31). The polyamines protected all the tested restriction sequences of DNA, since the activity of all endonucleases used was strongly inhibited. These results show the need for caution when using polyamines as experimental tools for recombinant DNA chemistry

Time points and risk factors for RhD immunizations after the implementation of targeted routine antenatal anti-D prophylaxis:a retrospective nationwide cohort study

Abstract Background: Targeted routine antenatal anti-D prophylaxis was introduced to the national prophylaxis program in Finland in late 2013. The aim of this study was to assess the incidence, time-points, and risk factors for Rhesus D immunization after the implementation of routine antenatal anti-D prophylaxis, in all women in Finland with antenatal anti-D antibodies detected in 2014–2017. Material and methods: In a nationwide population-based retrospective cohort study, the incidence, time-points, and risk factors of anti-D immunizations were analyzed. Information on antenatal screening was obtained from the Finnish Red Cross Blood Service database, and obstetric data from hospital records and the Finnish Medical Birth Register. Results: The study included a total of 228 women (197 with complete data for all pregnancies). After the implementation of routine antenatal anti-D prophylaxis, the prevalence of pregnancies with anti-D antibodies decreased from 1.52% in 2014 to 0.88% in 2017, and the corresponding incidence of new immunizations decreased from 0.33% to 0.10%. Time-points for detection of new anti-D antibodies before and after 2014 were the first screening sample at 8–12 weeks of gestation in 52% vs 19%, the second sample at 24–26 weeks in 20% vs 50%, and the third screening at 36 weeks in 28% vs 32%. Conclusions: The incidence of new anti-D immunizations decreased as expected after the implementation of routine antenatal anti-D prophylaxis. True failures are rare and they mainly occur when the prophylaxis is not given appropriately, suggesting a need for constant education of healthcare professionals on the subject