[Relationship between eruption status of mandibular third molars and thickness of the lingual bone].

PURPOSE: To estimate the relationship between the eruption status of the mandibular third molars and the thickness of the lingual bone. METHODS: Cone-beam CT (CBCT) data of 187 patients who underwent mandibular third molar extraction from Jan 2016 to Dec 2018 were selected. Lingual bone thickness at the levels of mid-root and root-apex of the third molars were measured using GALIEOS Viewer software, and the relationship between the eruption status of the mandibular third molars and the thickness of the lingual bone was estimated. SPSS 22.0 software package was used for Wilcoxon test, univariate and multivariate logistic regression analysis. RESULTS: The mean thickness of the lingual bone at the mid-root of the third molars was significantly less than that at the root apex (P<0.01). There was a significant correlation between the thickness of the lingual bone at the mid root and the mesiodistal angulations of the third molars. The thickness of the lingual bone at the mid root of mesioangularly and horizontally impacted third molars were significantly thinner (P<0.01). There was a significant correlation between the thickness of the lingual bone at the root apex and the impaction depth of the third molars. The thickness of the lingual bone at the root apex of medium and low positioned third molars were significantly thinner (P<0.05). CONCLUSIONS: The thickness of the lingual bone is associated with the eruption status of the mandibular third molars. Mesially angulated and lower positioned third molars are considered as the risk factors for the thinner lingual bone, so that lingual plate fracture should be prevented during tooth extraction.

[Forebrain NMDA receptor 2B subunit over-expression has no influence on anxiety behaviors of mice.].

It has been known that the glutamate transmission system and N-methyl-D-aspartate receptor (NMDA-R) were possibly related to anxiety processes. Although anxiety symptom can be relieved by NMDA-R antagonists and partial agonists treatment, the functions of NMDA-R and its subunits in anxiety behaviors remain unclear. We used forebrain specific NR2B over-expression mice to examine whether the increase of NR2B subunit level would induce anxiety behaviors. The results indicated that the juvenile (3-5 months old), middle-aged (8-10 months old) and old (19-22 months old ) NR2B transgenic mice showed no significant difference in open field test and elevated plus maze test as compared with the control mice. Capillary electrophoresis of monoamine neurotransmitter in subregions of forebrain revealed no significant difference between transgenic and control mice of 16-18 months age. These results suggest that the increase of NR2B expression and followed NR1 and NR2A expression augmentations in the forebrain have no significant effect on anxiety-related behaviors in mice.

[Transcription of cytoskeleton protein genes in differentiation of neurons from mouse embryonic stem cells induced by small molecules].

OBJECTIVE: To investigate the transcription of cytoskeleton protein genes in differentiation of neurons from mouse embryonic stem (ES) cells induced by all-trans retinoic acid (RA), and to explore the possibility of setting up a method to screen small molecules with promoting or inhibiting effect. METHODS: The hanging drop method was employed for embryonic body formation to mimic embryo development in vivo. Reverse transcriptase PCR (RT-PCR) was performed to investigate mRNA expression of the neuron-specific cytoskeleton proteins including Mtap2, Nefm and beta-tubulin III which were regarded as the inducing effect indexes of RA. Morphological evaluation and immunocytochemistry staining were conducted to identify the neural derivatives. Moreover, the inducing effects of six synthetic molecules were further evaluated. RESULT: RA up-regulated the mRNA expression of Mtap2 and Nefm, especially Mtap2 increased by 1.27 times, which was consistent with the morphological alteration. However, there was no significant changes of beta-tubulin III expression. With addition of the six synthetic molecules, the transcription of Mtap2 was inhibited, while the Nefm mRNA expression was up-regulated in some degree, especially for molecule 1 and 3 that was increased by 1.4 and 1.2 times, which, however, was not parallel to the morphological changes. CONCLUSION: The transcriptional levels of Mtap2 and Nefm are both up-regulated in the RA-induced differentiation of ES cells towards neurons. The up-regulation of Mtap2 is consistent with the morphological alteration, which might be the key landmark in the RA-induced differentiation of ES cells into neurons.

A Flavonoid Compound Promotes Neuronal Differentiation of Embryonic Stem Cells via PPAR-ß Modulating Mitochondrial Energy Metabolism.

Relatively little is known regarding mitochondrial metabolism in neuronal differentiation of embryonic stem (ES) cells. By using a small molecule, present research has investigated the pattern of cellular energy metabolism in neural progenitor cells derived from mouse ES cells. Flavonoid compound 4a faithfully facilitated ES cells to differentiate into neurons morphologically and functionally. The expression and localization of peroxisome proliferator-activated receptors (PPARs) were examined in neural progenitor cells. PPAR-ß expression showed robust upregulation compared to solvent control. Treatment with PPAR-ß agonist L165041 alone or together with compound 4a significantly promoted neuronal differentiation, while antagonist GSK0660 blocked the neurogenesis-promoting effect of compound 4a. Consistently, knockdown of PPAR-ß in ES cells abolished compound 4a-induced neuronal differentiation. Interestingly, we found that mitochondrial fusion protein Mfn2 was also abolished by sh-PPAR-ß, resulting in abnormal mitochondrial Ca2+ ([Ca2+]M) transients as well as impaired mitochondrial bioenergetics. In conclusion, we demonstrated that by modulating mitochondrial energy metabolism through Mfn2 and mitochondrial Ca2+, PPAR-ß took an important role in neuronal differentiation induced by flavonoid compound 4a.

Preparation of Unilamellar Immunoliposomes by Passing Reversed Micelles through Oil-water Interface.

A novel method for the preparation of unilamellar immunoliposomes is introduced. In this method, the aqueous phase is first encapsulated into reverse micelles passing through the oil-water interface, where the monolayer of lecithin embedded with antibody has been formed to self-assemble into immunoliposomes. The main advantages of this method are that the procedure of preparation is simple with high encapsulation yield and it is favorable for large scale production. As shown by negative staining electronic micrograph, the immunoliposomes are unilamellar and 100-500 nm in size. The UV spectra of immunoliposomes solution and lysis assay show that sheep anti-human IgG has been coated on liposomes.