Objective:To preliminarily explore the priority order of transfer of frozen low-quality blastocyst and high-quality cleavage embryos in the recovery frozen-thawed embryo transfer (FET) cycle of frozen embryos.Methods:In this retrospective study, 3677 in vitro fertilization-embryo transfer (IVF-ET) cycles were reviewed in Reproductive Medicine Center of the Third Affiliated Hospital of Zhengzhou University from November 2015 to May 2018. According to the stage of embryo development, quality and number of embryos transferred, the embryos were divided into five groups: single-non-high-quality blastocyst group (group A), single-high-quality blastocyst group (group B), day 3 (D3) double-high-quality embryo group (group C), D3 high-quality plus non-high-quality embryo group (group D) and D3 double-non-high-quality embryo group (group E). According to the age of the patients, they were divided into three subgroups, <35 years old, 35-37 years old and >37 years old. The main observation indicator was live birth rate, and the secondary observation indicators were clinical pregnancy rate, implantation rate, and multiple birth rate. Results:The implantation rates of double D3 embryos transfer groups (groups C-E) were significantly lower than those of single blastocyst groups (groups A and B)(all P<0.05), while the multiple pregnancy rates were significantly higher than those of single blastocyst groups (all P<0.01). There was no significant difference in clinical pregnancy rate between group C and group A ( P>0.05). Live birth rate increased significantly when patients were younger than 35 years old ( P=0.003), but there was no significant difference when patients were older than 35 years old. There was no significant difference in clinical pregnancy rate and live birth rate between group D and group A when patients were younger than 38 years old. When the patient was over 37 years old, the clinical pregnancy rate of group D was lower significantly ( P=0.018), but there was no significant difference in the live birth rate ( P>0.05). The clinical pregnancy rate and the live birth rate of group E were lower than those of group A. The difference was significant when the age of the patients was less than 35 years and more than 37 years (all P<0.01). There was no significant difference when the age of the patients was 35-37 years ( P>0.05). Age and the type of embryos transferred were independent factors affecting live birth. After adjusting the effect of age on live birth, compared with group A, the effects of group B ( OR=1.311, 95% CI=1.083-1.586, P=0.005), group C ( OR=1.322, 95% CI=1.092-1.601, P=0.004), group E ( OR=0.616, 95% CI=0.468-0.809, P=0.001) on the live birth rate were significantly different, while the effects of group D ( OR=1.139, 95% CI=0.914-1.420, P=0.247) on the live birth rate was not significantly different from those of group A. Conclusion:Considering multiple pregnancies and live births, the optimal transplantation sequence of frozen embryo transfer cycle may be single-high-quality blastocyst, single-non-high-quality blastocyst, D3 double-high-quality embryo, D3 high-quality plus non-high-quality embryo and D3 double-non-high-quality embryo.

Objective:To preliminarily explore the priority order of transfer of frozen low-quality blastocyst and high-quality cleavage embryos in the recovery frozen-thawed embryo transfer (FET) cycle of frozen embryos.Methods:In this retrospective study, 3677 in vitro fertilization-embryo transfer (IVF-ET) cycles were reviewed in Reproductive Medicine Center of the Third Affiliated Hospital of Zhengzhou University from November 2015 to May 2018. According to the stage of embryo development, quality and number of embryos transferred, the embryos were divided into five groups: single-non-high-quality blastocyst group (group A), single-high-quality blastocyst group (group B), day 3 (D3) double-high-quality embryo group (group C), D3 high-quality plus non-high-quality embryo group (group D) and D3 double-non-high-quality embryo group (group E). According to the age of the patients, they were divided into three subgroups, <35 years old, 35-37 years old and >37 years old. The main observation indicator was live birth rate, and the secondary observation indicators were clinical pregnancy rate, implantation rate, and multiple birth rate. Results:The implantation rates of double D3 embryos transfer groups (groups C-E) were significantly lower than those of single blastocyst groups (groups A and B)(all P<0.05), while the multiple pregnancy rates were significantly higher than those of single blastocyst groups (all P<0.01). There was no significant difference in clinical pregnancy rate between group C and group A ( P>0.05). Live birth rate increased significantly when patients were younger than 35 years old ( P=0.003), but there was no significant difference when patients were older than 35 years old. There was no significant difference in clinical pregnancy rate and live birth rate between group D and group A when patients were younger than 38 years old. When the patient was over 37 years old, the clinical pregnancy rate of group D was lower significantly ( P=0.018), but there was no significant difference in the live birth rate ( P>0.05). The clinical pregnancy rate and the live birth rate of group E were lower than those of group A. The difference was significant when the age of the patients was less than 35 years and more than 37 years (all P<0.01). There was no significant difference when the age of the patients was 35-37 years ( P>0.05). Age and the type of embryos transferred were independent factors affecting live birth. After adjusting the effect of age on live birth, compared with group A, the effects of group B ( OR=1.311, 95% CI=1.083-1.586, P=0.005), group C ( OR=1.322, 95% CI=1.092-1.601, P=0.004), group E ( OR=0.616, 95% CI=0.468-0.809, P=0.001) on the live birth rate were significantly different, while the effects of group D ( OR=1.139, 95% CI=0.914-1.420, P=0.247) on the live birth rate was not significantly different from those of group A. Conclusion:Considering multiple pregnancies and live births, the optimal transplantation sequence of frozen embryo transfer cycle may be single-high-quality blastocyst, single-non-high-quality blastocyst, D3 double-high-quality embryo, D3 high-quality plus non-high-quality embryo and D3 double-non-high-quality embryo.

Objective: To investigate the molecular evolution characteristics of human coronavirus (HCoV) subtypes in patients with fever and respiratory tract infection in Guangzhou from 2010 to 2012. Methods: Partial fragments of NP, RdRp and S genes of HCoV-OC43, HCoV-229E and HCoV-NL63 positive samples were amplified by RT-PCR and sequencing. Bioinformatics software, including Bio-edit, Mega4.0 and Clustal1.83 were used for comparison and analysis of NP, RDRp and S gene sequences. Molecular evolutionary tree of different gene regions of HCoV-OC43, HCoV-229E and HCoV-NL63 were built. Results: No remarkable variation or recombinant strain of HCoV-OC43, HCoV-229E and HCoV-NL63 was found in Guangzhou during 2010—2012. The HCoV-OC43 substrains were genetically closest to the strains found in Belgium and Hong Kong (GenBank accession number JN129834 and AY903460). HCoV-229E substrains were genetically closest to those found in Amsterdam (GenBank accession number JX503060) and HCoV-NL63 most genetically close to those in Amsterdam and Beijing (GenBank accession number JX104161 and DQ445911). The NP and RDRp genes of all subtypes were highly conserved, while S gene was more variable. Conclusions There were at least 3 substrains of HCoV-OC43, HCoV-229E and HCoV-NL63 epidemic in Guangzhou during 2010—2012, and no remarkable variation or recombinant viral strain was found. The NP and RDRp genes of all subtypes were highly conserved and can be used in virus detection, while S gene was more variable and suitable for phylogenetic and variation study.

AIM: To evaluate the effect of inhibiting ubiquitin-specific protease 14 (USPl4) activity on oxidative stress induced by H2O2 of H9c2 cells.METHODS: The H9c2 cells were incubated with H2O2 at 25 μmol/L for 2 h to establish the oxidative stress injury model.The cells were divided into control group, H2O2 group, IU1 group (25 μmol/L or 50 μmol/L) and IU1+ H2O2 group.The H9c2 cells activity was measured by MTS assay.The level of intracellular reactive oxygen species (ROS) and cell survival rate were analyzed by flow cytometry assay.The changes of the mitogen-activated protein kinase (MAPK) family related proteins were detected by Western blot.RESULTS: Compared with control group, the cell activity and the viability rate in H2O2 group were decreased (P<0.05), while the intracellular ROS, the protein levels of Bax/Bcl-2, P53, p-ERK1/2, p-JNK and p-P38 were increased (P<0.05).Compared with H2O2 group, the cell activity and the viability rate of the H9c2 cells in IU1+H2O2 group were increased (P<0.05), while the intracellular ROS, the protein levels of Bax/Bcl-2, P53, p-ERK1/2, p-JNK and p-P38 were decreased (P<0.05).CONCLUSION: Inhibition of USPl4 activity reduces the oxidative stress injury of the H9c2 cells.The mechanism may be related to inhibition of the MAPK signaling and down-regulation of apoptosis related proteins.