Clear aligners for maxillary anterior en masse retraction: a 3D finite element study.

To evaluate tooth behaviours under various maxillary incisor retraction protocols for clear aligner therapy. A three-dimensional finite element model of maxillary dentition was constructed for first premolar extraction. A loading method was developed to mimic the mode of action of clear aligners for incisor en masse retraction. Three protocols with different amounts of retraction and intrusion on incisors were designed. Initial tooth displacements and stresses on periodontal ligaments were analysed with ANSYS software. The central (U1) and lateral (U2) incisors exhibited uncontrolled lingual tipping and extrusion upon 0.25 mm retraction. U1 exhibited translation movement, while U2 underwent less tipping during 0.2 mm retraction and 0.15 mm intrusion. Labial tipping and intrusion of U1 and bodily intrusion of U2 were observed during 0.1 mm of retraction and 0.23 mm of intrusion. With the additional intrusion on incisors, canine showed extrusion movement, and higher stresses on periodontal ligaments were shifted from U2 to canines. Incisors also exhibited different mesial-distal angulation in the three simulations, while posterior teeth all suffered mesial inclination. Incorporating intrusion displacement in clear aligners led to a tendency of lingual root movement during incisor retraction. The complexity of tooth movement should be recognized regarding clear aligner therapy.

Zearalenone exposure elevated the expression of tumorigenesis genes in mouse ovarian granulosa cells.

Zearalenone (ZEA) is one of mycotoxins which are from corn, sorghum and wheat. As an estrogenic compound, ZEA mainly affects animal growth and reproduction with causing abnormal reproduction capability. Previous studies have shown that ZEA poses adverse effects on follicular development, but the mechanism of genetic toxicity of ZEA is not understood. The purpose of this study was to explore the effects of ZEA exposure on granulosa cells which play vital roles during follicular development. Mouse granulosa cells were exposed to 10 µM or 30 µM ZEA for 72 h in vitro, and the differences in gene expression patterns between control and ZEA exposures were analyzed by RNA-seq. The data demonstrated that 30 µM ZEA had a significant effect on the gene expression, especially ZEA exposure increased the expression of many genes related to different kinds of cancers and cancer related pathways like Hippo signaling pathway and the related genes, such as Ccnd1, Smad3, Tead3, Yap1 and Wwtr1. Furthermore, immunohistochemistry confirmed the increase in the protein levels of YAP1, WWTR1 and CCND1 in 30 µM ZEA exposure group. Collectively, this investigation indicated that ZEA exposure promoted the expression of tumorigenesis genes in mouse granulosa cells to.

Starvation during pregnancy impairs fetal oogenesis and folliculogenesis in offspring in the mouse.

Although it is becoming increasingly evident that maternal starvation during pregnancy can have permanent effects on a range of physiological processes in the offspring, scant information is available about the consequence of such condition for oogenesis and hence for lifetime reproductive success of progeny in mammals. In the present study, we address this topic by starving pregnant mice at the time of ovarian differentiation (12.5 days post coitum (dpc)) for three consecutive days and analyzed the consequence first on the survival of the fetal oocytes and their capability to progress throughout the stages of meiotic prophase I (MPI) and then on the postnatal folliculogenesis of the offspring. The results showed that maternal starvation increased apoptosis in the fetal ovaries, resulting in reduction of the oocyte number. Moreover, MPI progression was slowed down in the surviving oocytes and the expression of DNA repair players in the starved ovaries increased. Transcriptome analysis identified 61 differentially expressed genes between control and starved ovaries, the most part of these being involved in metabolic processes. A significant decrease in the percentage of oocytes enclosed in primordial follicles and the expression of oocyte genes critically involved in folliculogenesis such as Nobox, Lhx8 and Sohlh2 in the 3 days post partum (dpp) starved ovaries were found. Finally, at the time of juvenile period (21 dpp), the number of oocytes and antral follicles resulted significantly lower in the ovaries of the offspring from starved mothers in comparison to controls. Our findings support the notion that maternal starvation can affect ovary development in the offspring that could adversely affect their reproductive success in the adult life.

Mycotoxin zearalenone exposure impairs genomic stability of swine follicular granulosa cells in vitro.

Zearalenone (ZEA), a metabolite of Fusarium fungi, is commonly found on moldy grains. Because it can competitively combine to estrogen receptor to disrupt estrogenic signaling, it has been reported to have serious adverse effects on animal reproduction systems. In order to explore the genotoxic effects of ZEA exposure on ovarian somatic cells, porcine granulosa cells were exposed to 10 µM and 30 µM ZEA for 24 or 72 h in vitro. The results showed that ZEA exposure for 24 h remarkably reduced the proliferation of porcine granulosa cells in a dose-dependent manner as determined by MTT analysis and flow cytometry. Furthermore, exposure to ZEA for 72 h induced apoptosis, and RNA sequence analysis also revealed that the expression of apoptosis related genes were altered. RT-qPCR, immunofluorescence and western blot analysis further confirmed the expression of DNA damage and repair related genes (γ-H2AX, BRCA1, RAD51 and PRKDC) were increased in ZEA exposed granulosa cells. When the estrogen antagonist, tamoxifen, was added with ZEA in the culture medium, the DNA damage and repairment by ZEA returned to normal level. Collectively, these results illustrate that ZEA disrupts genome stability and inhibits growth of porcine granulosa cells via the estrogen receptors which may promote granulosa cell apoptosis when the DNA repair system is not enough to rescue this serious damage.

Ochratoxin A exposure decreased sperm motility via the AMPK and PTEN signaling pathways.

Ochratoxin A (OTA), a common mycotoxin found in nature, has been implicated as effecting the function of male reproductive systems. OTA exposure has been shown to decrease sperm production and quality, however, the underlying mechanisms remain unknown. In the current investigation boar sperm exposed to 10 and 100µM OTA in vitro for 24h resulted in significantly decreased motility, in the 100µM OTA treatment group when compared with the control group. The level of reactive oxygen species (ROS) was significantly increased in both of the OTA treatment groups. The increase in ROS activated phosphatase and the tensin homolog deleted on chromosome ten (PTEN) and inhibited the activation of protein kinase B (PKB, AKT), activated adenosine 5'-monophosphate (AMP), and activated protein kinase (AMPK) in the exposed sperm. Furthermore, activation of AMPK was enhanced by a decrease in ATPase. These changes culminated in a decline in boar sperm motility. PTEN/AMPK inhibitors significantly inhibited the expression of the two proteins in the OTA treatment group. In addition, there was increased expression of apoptosis markers in the OTA exposed sperm. In conclusion, these data suggest that OTA exposure affects the sperm motility via the AMPK and PTEN signaling pathways.

Impact of antiovarian antibodies (AOA) on ovarian responsiveness in vitro fertilization and embryo transfer.

OBJECTIVE: This study was to investigate the effects of antiovarian antibodies (AOA) on ovarian responsiveness in vitro fertilization and embryo transfer (IVF/ET). METHODS: 233 infertility women younger than 36 years undergone IVF/ET because of single salpingemphraxis were attended in the study, whose fast blood was taken to detect serum AOA by ELISA. Among them there were 35 women with serum AOA positive composed the study group and the other with serum AOA negative composed the control. Ovarian volume, antral follicle number, basal FSH, gonadotropin dosage and recollected oocytes were compared between the 2 groups. RESULT(S): There's no difference in ovarian volume between serum AOA positive group with negative group, P>0.05. The number of antral follicles was less and basal FSH was higher in AOA positive group than in control, P<0.05; what's more, the ampoules of gonadotrophin consumed in AOA positive group exceed significantly in control, and less recollected oocytes in AOA positive group than in control, P<0.01. Of the 233 infertility women, the serum AOA positive rate was 73.08% in the women who got less than 5 recollected oocytes, significantly higher than the other women in the study, P<0.01. CONCLUSION(S): The existing of anti-ovarian antibodies had suppressive effects on the ovarian responsiveness in ovarian stimulation in IVF/ET cycle and on ovarian function. AOA should be detected before IVF/ET to evaluate ovarian responsiveness and further treatment seems necessary.

[Autoimmune disorders affect the in vitro fertilization outcome in infertile women].

OBJECTIVE: To analyze the effect of autoimmune disorders on the outcome of in vitro fertilization and embryo transfer (IVF-ET) in infertile women. METHODS: A total of 236 infertile women underwent IVF-ET, including 34 with antiphospholipid antibody (APA) positive, 33 anti-trophoblast antibody (ATA) positive, 35 anti-hCG antibody (hCGAb) positive, 32 anti-endometrium antibody (EmAb) positive, and 102 with antibodies negative that comprised the control group. Those with two or more antibodies positive were excluded in this study. Comparisons were made in the rates of embryo implantation, clinical pregnancy, miscarriage and biochemical pregnancy between the positive groups and the negative controls. RESULTS: There were no significant differences in the rates of embryo implantation and clinical pregnancy between the positive and negative groups (P > 0.05). The rate of biochemical pregnancy was higher in the APA, ATA and hCGAb positive than in the EmAb positive and the control group (P < 0.05). The miscarriage rate was higher while the ongoing pregnancy rate was lower in the positive groups than in the negative control (P < 0.05). CONCLUSION: Such autoantibodies as APA, ATA, HCG-Ab and EmAb may cause miscarriage in infertile women undergoing IVF and consequently reduce the rate of ongoing pregnancy, which necessitates the determination of these antibodies in these patients.

Crystal structure of Enterococcus faecalis SlyA-like transcriptional factor.

The crystal structure of a SlyA transcriptional regulator at 1.6 A resolution is presented, and structural relationships between members of the MarR/SlyA family are discussed. The SlyA family, which includes SlyA, Rap, Hor, and RovA proteins, is widely distributed in bacterial and archaeal genomes. Current evidence suggests that SlyA-like factors act as repressors, activators, and modulators of gene transcription. These proteins have been shown to up-regulate the expression of molecular chaperones, acid-resistance proteins, and cytolysin, and down-regulate several biosynthetic enzymes. The structure of SlyA from Enterococcus faecalis, determined as a part of an ongoing structural genomics initiative (www.mcsg.anl.gov), revealed the same winged helix DNA-binding motif that was recently found in the MarR repressor from Escherichia coli and the MexR repressor from Pseudomonas aeruginosa, a sequence homologue of MarR. Phylogenetic analysis of the MarR/SlyA family suggests that Sly is placed between the SlyA and MarR subfamilies and shows significant sequence similarity to members of both subfamilies.