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BACKGROUND: In atrophic posterior mandibular areas, where the bone height superior to the inferior alveolar nerve (IAN) is less than 6 mm, short implants are not applicable. Conventional alternatives such as IAN transposition and various alveolar bone augmentation approaches are technically demanding and prone to complications. CASE SUMMARY: Computer-guided dynamic navigation implantation improves the accuracy, predictability, and safety of implant placement. This case report presents a dynamic navigation system-guided trans-IAN implant placement technique, which can successfully treat a posterior mandibular dentition defect when the bone height is only 4.5 mm. The implant was inserted into the buccal side of the IAN and was 1.7 mm away from the IAN. The implantation deviations were controlled within a satisfying range, and the long-term restoration outcome was stable. CONCLUSION: Dynamic navigation system-guided trans-IAN implant placement might be a recommended technique for patients with extremely insufficient residual bone height and sufficient bone width in the posterior mandibular area.

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This study aimed to investigate how 6-bromoindirubin-3'-oxime (BIO) increases the osteogenic differentiation of canine bone mesenchymal stem cells (BMSCs) and the role of the Wnt/ß-catenin signaling pathway in this process. We mimicked the effect of Wnt by adding BIO to the culture medium of BMSCs and examined whether canonical Wnt signaling positively affects the differentiation of these cells into osteoblasts. Canine BMSCs were cultured with 0.5 and 1.0 µM BIO under osteogenic conditions and then differentiation markers were investigated. It was found that BIO significantly increased the activity of alkaline phosphatase (ALP), the number of ALP-positive cells, the mineralization level and calcium deposits. Moreover, cells cultured with 0.5 and 1.0 µM BIO exhibited detectable ß-catenin expression in their nuclei, and showed upregulated ß-catenin and glycogen synthase kinase 3 beta(GSK3ß) phosphorylation compared to untreated cells. In addition, BIO enhanced the mRNA expression of osteoblast differentiation markers such as ALP, runt-related transcription factor 2, collagen I, osteocalcin, and osteonectin. In conclusion, BIO upregulated GSK3ß phosphorylation and inhibited its activity, thereby activating the Wnt/ß-catenin signaling pathway and promoting the osteogenic differentiation of canine BMSCs. The effect of 1.0 µM BIO on BMSCs differentiation was stronger than that of 0.5 µM BIO.

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Bone marrow mesenchymal stem cells (BMSCs) can transdifferentiate into different types of cells and may serve as a cell source for tissue engineering. Resveratrol has been shown to possess many benefits, including activation of osteogenesis. Furthermore, Wnt/ß-catenin signaling has been known to promote osteogenic differentiation in many cells. In this study, we investigated the role of resveratrol in osteoblastic differentiation of canine BMSCs. Resveratrol treatment of canine BMSCs remarkably increased alkaline phosphatase activity and calcium nodules, inhibited the function of glycogen synthase kinase 3ß, led to an increase in stabilization and nuclear accumulation of ß-catenin, and upregulated expression of osteoblast-related marker gene expression. In addition, resveratrol caused rapid activation of ERK1/2. Collectively, our results indicate that resveratrol promotes osteoblastic differentiation of canine BMSCs by activating the Wnt/ß-catenin; ERK/MAPK signaling pathways are also involved in osteogenic differentiation of canine BMSCs.

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This study compares superovulation efficiency during different stages of the estrus cycle in mice by investigating the pudendum appearance, vaginal epithelial cell type, and the follicular development dynamics, in relation to the estrus cycle. We determined the stages of the estrus cycle by observing the pudendum and making vaginal smears of the Kunming mouse, and ascertaining the follicular development by making paraffin sections. Based on the observation, mice in stages of proestrus, oestrus, metoestrus and dioestrus were superovulated respectively, and their follicular developments and embryo collection results were tracked to ascertain the appropriate estrus cycle stage for superovulation. Our data showed that pudendum appearance and vaginal smears could effectively distinguish different stages of the estrus cycle and that ovarian tissue observation showed that follicular development, corpus luteum formation and luteolysis were regular during the estrus cycle. Likewise, during the estrus cycle of the Kunming mouse, pudendum appearance, vaginal epithelial cell type and follicular development were relational to one another. Superovulating mice in different stages of the estrus cycle showed marked differences both in pregnancy rate and average number of embryos collected. Proestrus was significantly better than metoestrus and dioestrus (P<0.05), and better than oestrus, but the difference between them was not significant (P>0.05). We suggest that pudendum appearance and vaginal smears can be used to distinguish estrus cycle stages and that proestrus is the optimal stage of the estrus cycle for superovulation.

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The aims of this study were (i) to determine whether NSCs (neural stem cells) could be isolated from the brain of porcine fetuses at intermediate and late gestational age and (ii) to determine if these stem cells could be differentiated in vitro into osteogenic and neurogenic lineages following transfection with a reporter gene, EGFP (enhanced green fluorescence protein). The NSCs were isolated from the brains of porcine fetuses at intermediate and late gestational age and transfected with EGFP gene using lipofection. The transfected NSCs cells were induced to differentiate into cells of osteogenic and neurogenic lineages. Markers associated with NSCs and their osteogenic and neurogenic derivatives were tested by PCR. The results demonstrated that NSCs could be isolated from the brain of porcine fetus at intermediate and late gestational age and that transfected NSCs expressed EGFP and could be induced to differentiate in vitro. NSCs expressed CD-90, Hes1, Oct4, Sox2 and Nestin, while following differentiation cells expressed markers for osteogenic (osteocalcin and osteonectin) and neurogenic cells such as astrocyte [GFAP (glial fibrillary acidic protein)], oligodendrocyte [GALC (galactosylceramide)] and neuron [NF (neurofilament), ENO2 (enolase 2) and MAP (microtubule-associated protein)].

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The aim of this study was to transfect and express the enhanced green fluorescence protein (EGFP) gene into porcine neural stem cells (NSCs) to determine whether EGFP can be used as a marker to monitor NSCs. NSCs were isolated from embryonic day 30 fetal pig brain and transfected with EGFP gene using lipofection. Transfected and wild-type NSCs were induced to differentiate into cells of neuronal and myogenic lineages. Markers of passage three NSCs and their differentiated cells were tested by reverse transcription polymerase chain reaction. The results showed that EGFP could be expressed in NSCs and the differentiated cells. NSCs expressed Nestin, NogoA, DCX, Hes1, Oct4, CD-90 and Sox2. NSCs could differentiated into astrocyte (GFAP(+)), oligodendrocyte (GalC(+)), neuron (NF(+), NSE(+) and MAP2(+)) and myocyte (myf-6(+) and myoD(+)). We concluded that EGFP can be used as a marker in monitoring NSCs.

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We assessed the developmental ability of embryos cloned from porcine neural stem (NS) cells, amniotic fluid-derived stem (AFS) cells, fetal fibroblast cells, adult fibroblast, and mammary gland epithelial cells. The five cell lines were transfected with enhanced green fluorescence protein gene respectively using lipofection. NS and AFS cells were induced to differentiate in vitro. Stem cells and their differentiated cells were harvested for analysis of the markers using RT-PCR. The five cell lines were used for nuclear transfer. The two-cell stage-cloned embryos derived from each cell line were transferred into the oviducts of surrogate mothers. The results showed that both NS and AFS cells expressed POU5F1, THY1 and SOX2, and they were both induced to differentiate into astrocyte (GFAP+), oligodendrocyte (GalC+), neuron (NF+, ENO2+, and MAP2+), adipocyte (LPL+ and PPARG-D+), osteoblast (osteonectin+ and osteocalcin+), myocyte (MYF6+ and MYOD+), and endothelium (PECAM1+, CD34+, CDH5+, and NOS3+) respectively. Seven cloned fetuses (28 days and 32 days) derived from stem cells were obtained. The in vitro developmental ability (morula-blastocyst rate was 28.26-30.07%) and in vivo developmental ability (pregnancy rate were 1.67-2.17%) of the embryos cloned from stem cells were higher (P<0.05) than that of the embryos cloned from somatic cells (morula-blastocyst rate was 16.27-19.28% and pregnancy rate was 0.00%), which suggests that the undifferentiated state of the donor cells increases cloning efficiency.

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In order to research developmental competence of transgenic somatic cell by serial nuclear transplantation, goat cloned embryos were compared with recloned embryos in ability of in vitro development. Fetal fibroblasts including human finger-domain lacking t-PA gene was microinjected into cytoplasm of the MII oocytes. Goat embryos (G0) were cloned by this procedure. A single blastomere from 16 - 64-cell goat cloned embryos (G0) was microinjected into Intracytoplasm of the MII oocytes. Goat embryos (G) were cloned by this procedure. Goat embryos (G2, G3) were recloned by using 16 - 64-cell recloned embryos. The developmental time of donor embryo affected the developmental rate of recloned embryos (G1, G2). The results show: the cleavage rate of cloned embryos (G0) (76.45% +/- 1.17%) was no difference significantly with recloned embryos (G1 G2 G3) (72.18% +/- 1.97%, 76.05% +/- 2.38%, 75.99% +/- 2.84%); the developmental rate of morulae and blastocysts of cloned embryos (47.20% +/- 2.93%, 11.00% +/- 1.42%) were higher than these of recloned embryos(34.99% +/- 2.66%, 28.23% +/- 2.00%, 23.34% +/- 1.99%) (3.87% +/- 0.67%, 2.08% +/- 1.66%, 0); the morulae rate(29.57% +/- 1.53%, 24.43% +/- 1.87%) and blastocysts rate(1.96% +/- 1.31%, 2.01% +/- 1.34%) of recloned embryos (G1 G2) from 16-cell recloned embryos were lower than those(34.32% +/- 1.31%, 29.76% +/- 1.66% and 3.86% +/- 1.03%, 3.48% +/- 0.34% )from 32 - 64-cell recloned embryos (P > 0.05). In conclusion, nuclear transfer embryos should not were recloned mostly; and the embryos recloned by using 32 - 64-cell embryos achieved higher developmental ability compared with using 16-cell embryos.

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