Nitrite soaking pretreatment induced initial denitrifying nitrite accumulation.

Partial denitrification (PD) could be another method for obtaining nitrite. However, PD startup takes a long time limiting its investigation and application. This study proposed nitrite soaking as a pretreatment method for starting PD. Results showed that denitrifying nitrite accumulation (4.20 mg/L) emerged after previously soaking by 10 mg/L nitrite for 9 h. When the duration was 6 h, comparing different soaked nitrite concentrations, the highest denitrifying nitrite accumulation amount (4.92 mg/L) was obtained in the 20 mg/L group. Nevertheless, high pH of 9 and frequent feeding could further advantage denitrifying nitrite accumulation. Pretreatment as a disturbance would impel the microbial community to change from complete denitrification towards PD.

Modification of a plant-scale semi-centralized wastewater treatment system to enhance nitrogen and phosphorus removal from black water.

Owing to the low ratio of chemical oxygen demand to total nitrogen (SCOD/TN), effective removal of nutrient pollutants from black water is difficult. In this study, to enhance nitrogen and phosphorus removal from such wastewater, a series of operational modification strategies was investigated and applied to a plant-scale semi-centralized system used for black water treatment. The results showed that 21 mg Fe3+/L was the optimal dosage for the chemical-enhanced pretreatment process, achieving average removal efficiencies of 51.1 and 74.1% for organics and phosphorus, respectively, with a slight enhancement in nitrogen removal by 2.3%. However, nitrogen and phosphorus removal could be further enhanced to 88 and 96%, by the addition of carbon sources in the post-anoxic zone of the reversed anaerobic-anoxic-aerobic process. Contrastingly, neither the addition of carbon sources in the pre-anoxic zone nor the prolongation of the time for pre-denitrification could significantly improve the nitrogen and phosphorus removal efficiencies. Furthermore, reducing the aeration intensity promoted simultaneous nitrification and denitrification in aerobic reactors, thereby making it a potential energy-saving method for system operation.

Impacts of vitrification on the transcriptome of human ovarian tissue in patients with gynecological cancer.

Objective: This study investigated the effects of a vitrification/warming procedure on the mRNA transcriptome of human ovarian tissues. Design: Human ovarian tissues were collected and processed through vitrification (T-group) and then subjected to RNA sequencing (RNA-seq) analysis, HE, TdT-mediated dUTP nick-end labeling (TUNEL), and real-time quantitative PCR, and the results were compared to those of the fresh group (CK). Results: A total of 12 patients, aged 15-36 years old, with a mean anti-Müllerian hormone level of 4.57 ± 3.31 ng/mL were enrolled in this study. According to the HE and TUNEL results, vitrification effectively preserved human ovarian tissue. A total of 452 significantly dysregulated genes (|log2FoldChange| > 1 and p < 0.05) were identified between the CK and T groups. Among these, 329 were upregulated and 123 were downregulated. A total of 372 genes were highly enriched for 43 pathways (p < 0.05), which were mainly related to systemic lupus erythematous, cytokine-cytokine receptor interaction, the TNF signaling pathway, and the MAPK signaling pathway. IL10, AQP7, CCL2, FSTL3, and IRF7 were significantly upregulated (p < 0.01), while IL1RN, FCGBP, VEGFA, ACTA2, and ASPN were significantly downregulated in the T-group (p < 0.05) compared to the CK group, which agreed with the results of the RNA-seq analysis. Conclusion: These results showed (for the first time to the authors' knowledge) that vitrification can induce changes in mRNA expression in human ovarian tissues. Further molecular studies on human ovarian tissues are required to determine whether altered gene expression could result in any downstream consequences.

Elucidating performance failure in the use of an Anaerobic-Oxic-Anoxic (AOA) plug-flow system for biological nutrient removal.

The Anaerobic-oxic-anoxic (AOA) process is a carbon-saving and high-efficiency way to treat municipal wastewater and gets more attention. Recent reports suggest that in the AOA process, well-performed endogenous denitrification (ED), conducted by glycogen accumulating organisms (GAOs), is crucial to advanced nutrient removal. However, the consensuses about starting up and optimizing AOA, and in-situ enriching GAOs, are still lacking. Hence, this study tried to verify whether AOA could be established in an ongoing anaerobic-oxic (AO) system. For this aim, a lab-scale plug-flow reactor (working volume of 40 L) previously operated under AO mode for 150 days, during that 97.87 % of ammonium was oxidized to nitrate and 44.4 % of orthophosphate was absorbed. Contrary to expectations, under AOA mode, little nitrate reduction (only 6.3 mg/L within 5.33 h) indicated the failure of ED. According to high-throughput sequencing analysis, GAOs (Candidatus_Competibacter and Defluviicoccus) were enriched within the AO period (14.27 % and 3 %) and then still dominated during the AOA period (13.9 % and 10.07 %) but contributed little to ED. Although apparent alternate orthophosphate variations existed in this reactor, no typical phosphorus accumulating organisms were abundant (< 2 %). More than that, within the long-term AOA operation (109 days), the nitrification weakened (merely 40.11 % of ammonium been oxidized) since the dual effects of low dissolved oxygen and long unaerated duration. This work reveals the necessity of developing practical strategies for starting and optimizing AOA, and then three aspects in future studying are pointed out.

Towards low carbon demand and highly efficient nutrient removal: Establishing denitrifying phosphorus removal in a biofilm-based system.

The combined denitrifying phosphorus removal (DPR) and Anammox process is expected to achieve advanced nutrient removal with low carbon consumption. However, exchanging ammonia/nitrate between them is one limitation. This study investigated the feasibility of conducting DPR in a biofilm reactor to solve that problem. After 46-day anaerobic/aerobic operation, high phosphorus removal efficiency (PRE, 83.15 %) was obtained in the activated sludge (AS) and biofilm co-existed system, in which the AS performed better. Phosphate-accumulating organisms might quickly adapt to the anoxic introduced nitrate, but the following aerobic stage ensured a low effluent orthophosphate (<1.03 mg/L). Because of waste sludge discharging and AS transforming to biofilm, the suspended solids dropped below 60 mg/L on Day 100, resulting in PRE decline (17.17 %) and effluent orthophosphate rise (4.23 mg/L). Metagenomes analysis revealed that Pseudomonas and Thiothrix had genes for denitrification and encoding Pit phosphate transporter, and Candidatus_Competibacter was necessary for biofilm formation.

The mechanism of acentrosomal spindle assembly in human oocytes.

Meiotic spindle assembly ensures proper chromosome segregation in oocytes. However, the mechanisms behind spindle assembly in human oocytes remain largely unknown. We used three-dimensional high-resolution imaging of more than 2000 human oocytes to identify a structure that we named the human oocyte microtubule organizing center (huoMTOC). The proteins TACC3, CCP110, CKAP5, and DISC1 were found to be essential components of the huoMTOC. The huoMTOC arises beneath the oocyte cortex and migrates adjacent to the nuclear envelope before nuclear envelope breakdown (NEBD). After NEBD, the huoMTOC fragments and relocates on the kinetochores to initiate microtubule nucleation and spindle assembly. Disrupting the huoMTOC led to spindle assembly defects and oocyte maturation arrest. These results reveal a physiological mechanism of huoMTOC-regulated spindle assembly in human oocytes.

Can the combination of time-lapse parameters and clinical features predict embryonic ploidy status or implantation?

RESEARCH QUESTION: Can models based on artificial intelligence predict embryonic ploidy status or implantation potential of euploid transferred embryos? Can the addition of clinical features into time-lapse monitoring (TLM) parameters as input data improve their predictive performance? DESIGN: A single academic fertility centre, retrospective cohort study. A total of 773 high-grade euploid and aneuploid blastocysts from 212 patients undergoing preimplantation genetic testing (PGT) between July 2016 and July 2021 were studied for ploidy prediction. Among them, 170 euploid embryos were single-transferred and included for implantation analysis. Five machine learning models and two types of deep learning networks were used to develop the predictive algorithms. The predictive performance was measured using the area under the receiver operating characteristic curve (AUC), in addition to accuracy, precision, recall and F1 score. RESULTS: The most predictive model for ploidy prediction had an AUC, accuracy, precision, recall and F1 score of 0.70, 0.64, 0.64, 0.50 and 0.56, respectively. The DNN-LSTM model showed the best predictive performance with an AUC of 0.78, accuracy of 0.77, precision of 0.79, recall of 0.86 and F1 score of 0.83. The predictive power was improved after the addition of clinical features for the algorithms in ploidy prediction and implantation prediction. CONCLUSION: Our findings emphasize that clinical features can largely improve embryo prediction performance, and their combination with TLM parameters is robust to predict high-grade euploid blastocysts. The models for ploidy prediction, however, were not highly predictive, suggesting they cannot replace preimplantation genetic testing currently.

Complete androgen insensitivity syndrome caused by a novel mutation in the androgen receptor gene and its mechanism.

Androgen insensitivity syndrome (AIS) is an X-linked recessive genetic disease characterized by disorders of sex development, commonly caused by mutations of the androgen receptor (AR) gene. Herein, we identified a novel hemizygous mutation (c.2118T > A, p. Asn706Lys) of AR resulting in complete androgen insensitivity syndrome (CAIS) in twins. This missense mutation contributed to significantly decreased mRNA transcription and protein expression. In addition, structure model analysis showed that Asn706Lys resulted in loss of hydrogen bond with Asp891 and reduced protein stability. Furthermore, the mutant AR failed to bind to ligand due to the loss of hydrogen bond with dihydrotestosterone (DHT). This disrupted the translocation of AR protein from cytoplasm to nucleus after hormone stimulation. Our findings firstly demonstrated the novel mutation of c.2118T > A in AR directly caused CAIS. This contributed to expanding the AR mutational spectrum and revealed the pathogenic mechanism of AIS, as well as facilitating precise diagnosis and genetic counseling.

Hypoxia and its possible relationship with endometrial receptivity in adenomyosis: a preliminary study.

BACKGROUND: Adenomyosis (AM) is an important cause of female infertility. However, the underlying mechanism remains unclear. This report describes a preliminary study of hypoxia and its possible association with endometrial receptivity in AM. METHODS: The study was divided into in vitro and in vivo experiments. In vitro, expression levels of the endometrial receptivity markers HOXA10 and HOXA11 in the implantation period were examined using real-time PCR and western blotting. Endometrial expression of hypoxia-inducible factor (HIF)-1α, HIF-2α, and HIF-3α was determined using immunohistochemistry. In vivo, using an AM mouse model established by oral administration of tamoxifen, we inhibited expression of HIF-2α using an HIF-2α antagonist (PT2399; 30 mg/kg body weight, twice daily by oral gavage for 2 days) and then examined expression levels of Hoxa10 and Hoxa11 using real-time PCR and western blotting. RESULTS: Endometrial mRNA and protein expression levels of HOXA10 and HOXA11 were significantly lower in patients with AM than in control patients. Expression of HIF-2α was significantly higher in the AM group than in the control group, whereas that of HIF-1α and HIF-3α was equivalent in both groups. In vivo analysis showed that administration of the HIF-2α antagonist resulted in increased expression of Hoxa10 and Hoxa11 at both the mRNA and protein levels in AM model mice. CONCLUSIONS: HIF-2α overexpression may be one reason for decreased endometrial receptivity in AM. The current findings provide insight into HIF-2α-mediated AM-related infertility and suggest that PT2399 has potential as a treatment for AM. TRIAL REGISTRATION: This trial was retrospectively registered.

MicroRNA-451 is downregulated in the follicular fluid of women with endometriosis and influences mouse and human embryonic potential.

BACKGROUND: Previous work demonstrated that there are numerous miRNAs in human follicular fluids, some of which are associated with reproductive diseases. In the current study, we sought to determine whether microRNAs (miRNAs) in the follicular fluid (FF) are differentially expressed between women with and without endometriosis and to uncover the association of miRNAs with the oocyte and embryonic development potential. METHODS: FF was harvested from 30 women with endometriosis and 30 women without who underwent in vitro fertilization treatment at the University Hospital between February and December 2016. The FF samples were subjected to miRNA profiling and validation via quantitative reverse transcription polymerase chain reaction analysis. Mouse/human metaphase-I (MI) oocytes were harvested and micro-injected with an miR-451 inhibitor, and the effects of miR-451 knockdown on Wnt/WNT signalling genes were investigated. RESULTS: Oocyte number, fertilization rate, and number of available embryos were decreased significantly in women with endometriosis relative to those without endometriosis. Hsa-miR-451 in FF was downregulated in endometriosis patients relative to control subjects (P < 0.01). Moreover, the proportions of mouse/human MI oocytes that developed into 2-pronuclei (2PN), 2-cell, 8-10-cell and blastocyst-stage embryos were affected by miR-451 knockdown in mouse/human oocytes. Components of the Wnt signalling pathway were aberrantly expressed in the mouse/human oocytes and embryos in the miR-451 inhibitor-injected group. CONCLUSIONS: miR-451 was downregulated in FF samples from endometriosis patients and was modestly effective in distinguishing endometriosis patients from non-endometriosis patients. miR-451 downregulation in mouse and human oocytes affected pre-implantation embryogenesis by suppressing the Wnt signalling pathway. This miRNA might serve as a novel biomarker of oocyte and embryo quality in assisted reproductive treatment.

Preincubation with glutathione ethyl ester improves the developmental competence of vitrified mouse oocytes.

PURPOSE: Oocyte vitrification is currently used for human fertility preservation. However, vitrification damage is a problem caused by decreasing ooplasmic levels of glutathione (GSH). The GSH donor glutathione ethyl ester (GSH-OEt) can significantly increase the GSH content in oocytes. However, it is difficult to obtain oocyte from woman. To overcome this, we used mouse oocytes to replace human oocytes as a model of study. METHODS: Oocytes from B6D2F1 mice were preincubated for 30 min with 2.5 mmol/L GSH-OEt (GSH-OEt group), without GSH-OEt preincubation before vitrification (control vitrification group) or in nonvitrified oocytes (fresh group). After thawing, oocytes were fertilized for evaluating the developmental competence of embryos in vitro and in vivo. Immunofluorescence, Polscope equipment and quantitative reverse transcription polymerase chain reaction (RT-qPCR) were used to analyze damage, including mitochondrial distribution, reactive oxygen species (ROS) levels, spindle morphology, and gene expression levels (Bcl-2, BAX, and MnSOD). RESULTS: The rates of fertilization, 3-4 cell, blastocyst formation and expanded blastocysts were significantly higher (p < 0.05) in the GSH-OEt group (90.4%; 91.1%; 88.9% and 63.0%) than in the control (80.0%; 81.4%; 77.7% and 50.5%). Provided embryos overcame the 2-cell block and developed to the blastocyst stage, birth rates of all groups were similar. Vitrification altered mitochondrial distribution, increased ROS levels, and caused abnormal spindle morphology; GSH-OEt preincubation could improve such damage. RT-qPCR showed that the expression of Bcl-2 was lower in the control group compared with the GSH-OEt group; BAX and MnSoD expression levels were higher in the control group than in the GSH-OEt group (p < 0.05). CONCLUSIONS: The beneficial effect of GSH-OEt preincubation occurred before the 2-cell stage.

Screening of miRNAs in human follicular fluid reveals an inverse relationship between microRNA-663b expression and blastocyst formation.

RESEARCH QUESTION: Are miRNAs found in follicular fluid related to blastocyst formation from the corresponding oocytes? DESIGN: In this study, 91 individual follicular fluid samples from single follicles containing mature oocytes from 91 women were collected and classified into group 1 (n = 38) with viable blastocysts, and group 2 (n = 53) with no blastocyst. TaqMan human miRNA cards and quantitative reverse transcription polymerase chain reaction were used to identify differently expressed follicular fluid miRNAs between the two groups. RESULTS: We found MIR-663B to be significantly differentially expressed in follicular fluid of oocytes that yielded viable blastocysts versus those that did not develop into blastocysts (14.16 ± 7.00 versus 23.68 ± 17.02; P = 0.019), as well as for those which develop into blastocysts with good morphology versus those with poor morphology (11.69 ± 3.49 versus 20.16 ± 9.33; P = 0.003). CONCLUSIONS: MIR-663B expression levels in human follicular fluid samples were significantly negatively related to viable blastocyst formation and may become an objective evaluation criterion for embryo development potential after IVF.

Transcriptome analysis of endometrial tissues following GnRH agonist treatment in a mouse adenomyosis model.

PURPOSE: Adenomyosis is a common, benign gynecological condition of the female reproductive tract characterized by heavy menstrual bleeding and dysmenorrhea. Gonadotropin-releasing hormone (GnRH) agonists are one of the medications used in adenomyosis treatment; however, their underlying mechanisms are poorly understood. Moreover, it is difficult to obtain endometrial samples from women undergoing such treatment. To overcome this, we generated an adenomyosis mouse model, which we treated with an GnRH agonist to determine its effect on pregnancy outcomes. We also analyzed endometrial gene expression following GnRH agonist treatment to determine the mechanisms that may affect pregnancy outcome in individuals with adenomyosis. METHODS: Neonatal female mice were divided into a control group, an untreated adenomyosis group, and an adenomyosis group treated with a GnRH agonist (n=6 each). The pregnancy outcome was observed and compared among the groups. Then, three randomly chosen transcriptomes from endometrial tissues from day 4 of pregnancy were analyzed between the adenomyosis group and the GnRH agonist treatment group by RNA sequencing and quantitative reverse transcription polymerase chain reaction (PCR). RESULTS: The litter size was significantly smaller in the adenomyosis group than in the control group (7±0.28 vs 11±0.26; P<0.05). However, the average live litter size was increased (10±0.28 vs 7±0.28; P<0.05) after GnRH agonist treatment. Three hundred and fifty-nine genes were differentially expressed in the GnRH agonist-treated group compared with the untreated group (218 were downregulated and 141 were upregulated). Differentially expressed genes were related to diverse biological processes, including estrogen metabolism, cell cycle, and metabolite biosynthesis. CONCLUSION: GnRH agonist treatment appears to improve the pregnancy outcome of adenomyosis in a mouse model. Besides pituitary down-regulation, other possible mechanisms such as the regulation of cell proliferation may play a role in this. These new insights into GnRH agonist mechanisms will be useful for future adenomyosis treatment.

Improved cryotolerance and developmental competence of human oocytes matured in vitro by transient hydrostatic pressure treatment prior to vitrification.

BACKGROUND: At present, the metaphase II (MII) oocytes have a very special structure that leads to complex difficulties associated with its vitrification, and their efficacy still needs a large amount of study to observe. The present study was to investigate whether transient hydrostatic pressure (THP), which was utilized for oocytes before vitrification, had positive effect on the oocytes' developmental ability and reactive oxygen species, and had no damage on meiotic spindle, zona pellucida, and DNA copy number. METHODS: All the immature oocytes used in this research were collected between February 2015 and December 2015 in Shanghai Ji Ai Genetics & IVF Institute. The MII oocytes, which were originated from metaphase I (MI) oocytes, were randomly distributed into three groups: A) fresh oocytes; B) vitrification; and C) vitrification after THP treatment. The embryo developmental outcome was evaluated after intracytoplasmic sperm injection and embryo culture. Furthermore, the meiotic spindle behavior, reactive oxygen species (ROS), zona pellucida (ZP), and DNA copy number variation were evaluated and compared among the three groups. RESULTS: A total of 568 MII oocytes were included in the study. Embryos from group B had fewer cells on day 3 compared with group A and C (5.01 ± 2.11 for group A, 3.89 ± 2.21 for group B, and 4.69 ± 2.05 for group C). The developmental feature of blastocyst in groups A and C were superior to those of group B. The MII oocytes were manipulated with THP before vitrification, and the equilibration time was significantly shorter in the vitrification procedure (244.9 ± 30.1 vs. 181.5 ± 10.1). The ROS, ZP of vitrified/warmed oocytes in group C were improved with THP before vitrification. THP had no influence on the meiotic spindle and DNA copy number variation of vitrified/warmed oocytes. CONCLUSIONS: The results of the study indicated that sublethal THP treatment before vitrification increased the developmental competence of human in vitro matured oocytes, reduced vitrification-related changes in the ROS, which occurred during oocyte vitrification, and did not damage the meiotic spindle, ZP and DNA copy number variation.

Vitrification of in vitro matured oocytes diminishes embryo development potential before but not after embryo genomic activation.

PURPOSE: The aim of this study is to evaluate the impact of oocyte vitrification on embryo development potential and to assess the chromosome abnormalities of blastocysts derived from fresh/vitrified-warmed oocytes to assure the safety of the oocyte cryopreservation technique. METHODS: In vitro matured oocytes derived from immature oocytes were retrieved from small follicles during IVF/intracytoplasmic sperm injection (ICSI) cycles were randomly divided into a fresh and vitrified-warmed groups. After intracytoplasmic sperm injection, the fertilization rate, embryo quality, and developmental status were compared between the two groups. Blastocysts derived from both groups were analyzed using the copy number variation (CNV)-seq technique to evaluate DNA abnormalities. RESULTS: The fertilization rate with ICSI and the cleavage rate were similar between the two groups. Among the vitrified-warmed group, there was a lower incidence of usable embryos on day 3 (16.42 vs. 28.57 %; P < 0.05) and a lower incidence of blastocysts (7.46 vs. 17.86 %; P < 0.05). However, the proportions of embryos that developed to blastocysts from the day 3 available embryos were similar between the two groups (62.5 vs. 45.45 %; P > 0.05). In the day 3 embryos, the proportion of >5 cell embryos in the fresh group was markedly higher than in the vitrified-warmed group (41.67 vs. 21.64 %; P < 0.05), and the proportion of embryos with ≧50 % fragments was not significantly different between the two groups (39.29 vs. 43.28 %; P > 0.05). The result of CNV-seq demonstrated that there was no difference in chromosomal abnormalities between the two groups (20 vs. 20 %). CONCLUSIONS: Oocyte vitrification and the warming procedure diminished the embryo development potential before day 3, when embryo genomic activation started. The day 3 usable embryos derived from vitrified-warmed oocytes had the same potential for developing into blastocysts. Vitrification and the warming procedure did not increase the chromosome abnormalities of the blastocysts. Oocyte vitrification is a safe technique for those patients who have no other options, although the oocyte efficiency may be diminished after the vitrified-warmed procedure.

Associations between insulin resistance, free fatty acids, and oocyte quality in polycystic ovary syndrome during in vitro fertilization.

CONTEXT: Both polycystic ovary syndrome (PCOS) and obesity are associated with specific reproductive health complications, including lower oocyte quality and clinical pregnancy rates in assisted conception cycles, which may be a result of metabolism-induced changes in the oocyte through the microenvironment of follicular fluid. Free fatty acids (FFAs) are important biomedical indicators of abnormal lipid metabolism and have pronounced effects on cells, leading to changes in metabolism, cell growth, and differentiation. OBJECTIVE: Our objective was to determine the effect of FFA metabolism in plasma and follicular fluid on oocyte quality in the women with PCOS undergoing in vitro fertilization. DESIGN AND SETTING: Ninety-three women undergoing in vitro fertilization treatment, including 55 with PCOS and 38 age-matched controls, were recruited. PCOS patients were divided into obese and nonobese subgroups on the basis of their body mass index. MAIN OUTCOME MEASURES: Embryo quality was morphologically assessed, and serum sex hormone and insulin levels were measured. FFAs in plasma and follicular fluid were measured using gas chromatography-mass spectrometry. RESULTS: PCOS was found to be associated with significantly higher LH/FSH, total T, free androgen index (FAI), and lower SHBG levels, independent of obesity(P < .05). Obese women with PCOS had a significantly higher total T level, FAI, fasting insulin, insulin resistance index as determined by homeostasis model assessment for insulin resistance, and lower SHBG levels than the nonobese women with PCOS (P < .05). The embryo fragmentation score was significantly positively correlated with the oleic acid concentration in all PCOS patients (r = 0.22, P = .04, for nonobese patients and r = 0.25, P = .03, for obese patients). CONCLUSIONS: Our findings clearly demonstrated that PCOS is associated with significantly higher FAI and insulin resistance levels and decreased plasma SHBG levels, independent of body mass index. Obese PCOS patients had higher palmitoleic acid and oleic acid levels in both the plasma and follicular fluid than did the control subject and nonobese PCOS patients. Our results indicated that developmental competence is associated with oleic and stearic acid concentrations, which may contribute to the poor pregnancy outcomes in patients with PCOS.

[Application of human oocyte morphometric parameters in assessment of fertilization and embryo development].

OBJECTIVE: To investigate the correlation of human oocyte morphometric parameters with fertilization and embryo development in the intracytoplasmic sperm injection (ICSI) cycles. METHODS: The morphometric parameters of oocytes collected and submitted to evaluation using OCTAX Eye-ware software just before ICSI. Oocyte diameter (OD), perivitelline space width (PSW), zonapellucida thickness (ZPT) and the shape of first polar body (FPB) (intact or fragmented) were analyzed. A stepwise multivariate Logistic regression was used to test the association between the morphometric parameters and fertilization and embryo development. RESULTS: In the study, 436 oocytes were measured and 370 were fertilized (84.9%), 225 fertilized oocytes were developed to high-quality embryos (60.8%). ZPT and PSW were associated with fertilization. The oocytes fertilized had thicker ZPT [(18.0±2.3) µm vs. (16.9±2.7) µm] and wider PSW [(14.4±3.3) µm vs. (13.2±3.9) µm]. The OD and shape of FPB were associated with embryos development. The oocytes developed to high-quality embryos had larger OD [(116.6±3.7) µm vs. (114.7±3.6) µm] and more intact FPB (86.2% vs. 66.7%). CONCLUSION: The morphometric parameters of oocytes can indicate fertilization and embryo development.

Dynamic changes of histone H3 trimethylated at positions K4 and K27 in human oocytes and preimplantation embryos.

OBJECTIVE: To investigate the distribution patterns of H3K4me3 and H3K27me3 in human oocytes and preimplantation embryos. DESIGN: Experimental study. SETTING: University reproductive medical center. PATIENT(S): Patients undergoing IVF cycles. INTERVENTION(S): Oocytes and embryos were collected from patients undergoing IVF cycles. MAIN OUTCOME MEASURE(S): The distribution patterns of H3K4me3 and H3K27me3 in oocytes and embryos were analyzed by indirect immunofluorescent staining and scanning confocal microscopy. RESULT(S): H3K4me3 and H3K27me3 signals were detectable at each stage of oocyte and embryonic development. However, only one of the pronuclei showed signal for H3K27me3 in each of the zygotes, whereas H3K4me3 staining was always uniform in all zygotes. The level of H3K4me3 decreased steadily from germinal vesicle to metaphase II stage, obviously increased from zygote stage to four-cell stage, and reached the lowest at eight-cell stage. A sharp increase was then observed at blastocyst stage. The level of H3K27me3 slightly changed from germinal vesicle stage to zygote stage, then decreased steadily and reached the lowest at eight-cell stage, followed by a significant increase at blastocyst stage. CONCLUSION(S): The levels of H3K4me3 and H3K27me3 show dynamic changes during human oocyte maturation and preimplantation embryonic development. Asymmetric distribution of H3K27me3 exists in human zygote pronuclei, whereas H3K4me3 is always uniform in all of the pronuclei.

Frozen-thawed embryo transfer cycles in China: clinical outcomes of two and three multicellular embryos transfers.

PURPOSE: To analyze the clinical outcomes of frozen embryo transfer (FET) cycles when two or three multicellular embryos were transferred in Chinese women. METHODS: A retrospective study was conducted to analyze 980 FET cycles performed between January 2007 and October 2010. Two (785 cycles) or three (195 cycles) multicellular embryos were transferred. RESULTS: Both in patients under 35 years (n = 776) and those aged 35 to 39 years (n = 169), the transfer of two versus three multicellular embryos results in similar clinical pregnancy rates (CPR), implantation rates (IR) and live birth rates (LBR). In both age groups, the multiple pregnancy rate (MPR) was significantly higher in the three-embryo groups. Among women over 40 years of age (n = 35), there were no differences in the CPR, IR, MBR or LBR between the two groups CONCLUSIONS: Transferring two instead of three multicellular embryos in patients under 40 years old significantly decreases the risk of MPR without compromising PR, IR and LBR. In the age group above 40, transferring two instead of three multicellular embryos did not decrease PR, IR, MBR or LBR. Transferring more embryos when a patient had more unsuccessful cycles was not warranted in all patients.