Does a poor-quality embryo have an adverse impact on a good-quality embryo when transferred together?

Abstract Background In some in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles, we may consider transferring one poor-quality embryo with one good-quality embryo. Previous studies have indicated that the poor-quality embryo transferred with a good-quality embryo does not negatively affect the clinical pregnancy rate or live birth rate. The purpose of this study was to evaluate pregnancy outcomes and neonatal outcomes in this context. Methods This was a retrospective study that included 1646 cycles from our centre. Patients were divided into two groups (group A: one good-quality embryo was transferred with one poor-quality embryo; group B: two good-quality embryos were transferred). The primary outcomes were the clinical pregnancy rate and live birth rate. Additionally, we investigated the implantation rate, ectopic pregnancy rate, abortion rate, multiple pregnancy rate, birthweight and gestational age. Results We found that there were no differences in the clinical pregnancy rate and live birth rate between group A and group B. However, the implantation rate and multiple pregnancy rate were higher in group B than in group A. Conclusions The poor-quality embryo does not have a significant influence on the good-quality embryo when transferred together

A comprehensive synthetic library of poly-N-acetyl glucosamines enabled vaccine against lethal challenges of Staphylococcus aureus

Abstract Poly-β-(1–6)-N-acetylglucosamine (PNAG) is an important vaccine target, expressed on many pathogens. A critical hurdle in developing PNAG based vaccine is that the impacts of the number and the position of free amine vs N-acetylation on its antigenicity are not well understood. In this work, a divergent strategy is developed to synthesize a comprehensive library of 32 PNAG pentasaccharides. This library enables the identification of PNAG sequences with specific patterns of free amines as epitopes for vaccines against Staphylococcus aureus (S. aureus), an important human pathogen. Active vaccination with the conjugate of discovered PNAG epitope with mutant bacteriophage Qβ as a vaccine carrier as well as passive vaccination with diluted rabbit antisera provides mice with near complete protection against infections by S. aureus including methicillin-resistant S. aureus (MRSA). Thus, the comprehensive PNAG pentasaccharide library is an exciting tool to empower the design of next generation vaccines