Whole-genome DNA methylomes of Tree shrew brains reveal conserved and divergent roles of DNA methylation on sex chromosome regulation.

The tree shrew (Tupaia belangeri) is a promising emerging model organism in biomedical studies, notably due to their evolutionary proximity to primates. To enhance our understanding of how DNA methylation is implicated in regulation of gene expression and the X chromosome inactivation (XCI) in tree shrew brains, here we present their first genome-wide, single-base-resolution methylomes integrated with transcriptomes from prefrontal cortices. We discovered both divergent and conserved features of tree shrew DNA methylation compared to that of other mammals. DNA methylation levels of promoter and gene body regions are negatively correlated with gene expression, consistent with patterns in other mammalian brains studied. Comparing DNA methylation patterns of the female and male X chromosomes, we observed a clear and significant global reduction (hypomethylation) of DNA methylation across the entire X chromosome in females. Our data suggests that the female X hypomethylation does not directly contribute to the gene silencing of the inactivated X chromosome nor does it significantly drive sex-specific gene expression of tree shrews. However, we identified a putative regulatory region in the 5' end of the X inactive specific transcript (Xist) gene, a key gene for XCI, whose pattern of differential DNA methylation strongly relate to its differential expression between male and female tree shrews. We show that differential methylation of this region is conserved across different species. Moreover, we provide evidence suggesting that the observed difference between human and tree shrew X-linked promoter methylation is associated with the difference in genomic CpG contents. Our study offers novel information on genomic DNA methylation of tree shrews, as well as insights into the evolution of X chromosome regulation in mammals.

Hybrid molecularly imprinted polymers for targeted separation and enrichment of 10-hydroxycamptothecin in Camptotheca acuminata Decne.

The molecularly imprinted polymer was synthesized using 3-aminopropylthiosilane-methacrylic acid monomer (APTES-MAA) as the functional monomer and 10-hydroxycamptothecin (HCPT) as the template, based on computer simulation. The hybrid molecularly imprinted polymers (HMIPs) were characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, particle size measurement, scanning electron microscopy and energy dispersive X-ray spectroscopy. It has been shown that HMIPs are irregularly shaped and porous, with particle sizes ranging mainly from 130 to 211 nm. At 298 K, the HMIPs exhibit a maximum adsorption capacity of 8.35 mg·g-1 for HCPT and demonstrate good adsorption specificity (α = 5.38). The pseudo-second-order reaction mechanism suggests that the equilibrium adsorption capacity of HCPT on HMIPs is 8.11 mg·g-1. Finally, HCPT was successfully separated and enriched from the extract of Camptotheca acuminata Decne. seeds using HMIPs.

[MiR-99a inhibits proliferation of oral squamous cell carcinoma by targeting mTOR pathway].

PURPOSE: To investigate miR-99a expression and its effect on proliferation of oral squamous cell carcinoma (OSCC). METHODS: miRNA microarrays associated with OSCC were identified in GEO database. The expression levels of miR-99a were detected in 63 OSCC tissues and adjacent normal tissues and cell lines. The relationship between clinicopathological parameters and miR-99a expression was analyzed by using ANOVA analysis. The ability of cell growth and clone formation were examined in SCC9 and SCC25 cells transfected with miR-99a mimics. The target genes of miR-99a were predicted by Targetscan software. There resulting data were analyzed using SPSS 19.0 software package. RESULTS: The differently expressed miRNAs were analyzed based on GSE103931 microarray. miR-99a was significantly downregulated in OSCC tissues and cell lines. miR-99a expression was significantly associated with T stage, pathological grading and patients' prognosis. miR-99a overexpression inhibited OSCC cell proliferation and clone formation, while miR-99a inhibition contributed to decreased proliferation and clone formation ability. In addition, miR-99a combined with mTOR gene's 3'UTR was negatively correlated with mTOR expression in OSCC tissues. CONCLUSIONS: miR-99a functions as a tumor suppressor in OSCC and inhibits OSCC cell proliferation by targeting mTOR.

Retrospective analysis of the treatment of mandibular condylar sagittal fracture with Kirschner wire in 13 cases / 口腔疾病防治

Objective@#To evaluate the value of Kirschner wire internal fixation in the treatment of sagittal mandibular condylar fractures.@*.Methods @#From January 2019 to January 2020, 13 patients (19 sides) with mandibular condylar sagittal fracture treated by Kirschner wire internal fixation at the Stomatological Medical Center, Foshan Hospital of Traditional Chinese Medicine were retrospectively analyzed. After conventional surgical incision and exposure and reduction of the mandibular condyle, 2-4 Kirschner wires were used for fixation, and other maxillofacial fractures were treated simultaneously. The reduction accuracy and stability of the free mandibular condyle were evaluated by CBCT one week after the operation, and the occlusion relationship, opening degree and opening type were evaluated by clinical examination.@*Results@#All patients had good fracture alignment and no twisting, breaking or loosening of the Kirschner wire. The occlusion relationship, opening degree and opening shape recovered well after the operation.@*Conclusion@# Kirschner wire is effective in treating sagittal fractures of mandibular condyles.

Clinical analysis of 5 cases of odontogenic maxillofacial-neck-mediastinal infection treated with negative pressure sealing drainage / 口腔疾病防治

Objective @#To explore the effect of negative pressure sealing drainage on the treatment of maxillofacial-neck-mediastinal infection in multiple spaces.@*Methods@# Vacuum sealing drainage (VSD) was applied in five patients with maxillofacial-neck-mediastinal infection caused by odontogenic infection accompanied by diabetes or renal failure and other systemic diseases. After extensive debridement, a negative pressure drainage sponge was placed in the pus cavity and then the wound was closed. Continuous negative pressure drainage was continued after the operation. At the same time, multidisciplinary consultation was applied to control basic diseases and, strengthen anti-inflammatory responses, and nutrition and other systemic treatments were applied.@*Results@#Four patients underwent continuous negative pressure drainage and successful removal of the negative pressure sponge after inflammatory symptoms subsided. One patient′s inflammatory symptoms became more serious after the operation, and we performed another operation to change the placement of the negative pressure sponge. All 5 patients underwent VSD with negative pressure sponge replacement ranging from 1 to 3 times during treatment. After multidisciplinary consultation, they were all cured and discharged from the hospital.@*Conclusion@#For infection of the mediastinum, maxillofacial region and neck, local treatment and systemic treatment are emphasized, as well as the treatment of infected lesions and basic diseases. Negative pressure closure and drainage technology promotes the alleviation of inflammation, and multidisciplinary combined treatment is beneficial for the control of basic diseases.

Clinical effect of mouth floor approach intubation in jaw fracture combined with brain injury / 口腔疾病防治

Objective @#To explore the effects of mouth floor approach intubation in the treatment of jaw fracture combined with skull base injury.@*Methods @#From Jan. 2014 to Oct. 2015, 7 cases of jaw fracture combined with skull base injury were selected from Medical center of Stomatology, Foshan Hospital of Traditional Chinese Medicine (FSTCM). All cases were treated with mouth floor approach intubation, because they were not suitable to be given the oral or nasal intubation anesthesia. @*Results @#All the patients healed well after operation, and there was no tube accident or other complications.@*Conclusions@# For patients of jaw fracture combined with skull base injury, the mouth floor approach intubation could be recommended as a supplementary choice for traditional intubation methods.

Water and nitrogen availability co-control ecosystem CO2 exchange in a semiarid temperate steppe.

Both water and nitrogen (N) availability have significant effects on ecosystem CO2 exchange (ECE), which includes net ecosystem productivity (NEP), ecosystem respiration (ER) and gross ecosystem photosynthesis (GEP). How water and N availability influence ECE in arid and semiarid grasslands is still uncertain. A manipulative experiment with additions of rainfall, snow and N was conducted to test their effects on ECE in a semiarid temperate steppe of northern China for three consecutive years with contrasting natural precipitation. ECE increased with annual precipitation but approached peak values at different precipitation amount. Water addition, especially summer water addition, had significantly positive effects on ECE in years when the natural precipitation was normal or below normal, but showed trivial effect on GEP when the natural precipitation was above normal as effects on ER and NEP offset one another. Nitrogen addition exerted non-significant or negative effects on ECE when precipitation was low but switched to a positive effect when precipitation was high, indicating N effect triggered by water availability. Our results indicate that both water and N availability control ECE and the effects of future precipitation changes and increasing N deposition will depend on how they can change collaboratively in this semiarid steppe ecosystem.