BACKGROUND:Bone marrow mesenchymal stem cells (BMSCs) can be induced to differentiate into neuron-like cells directional y. Accordingly, BMSCs can be used as seed cells theoretical y in constructing tissue-engineered peripheral nerves.
OBJECTIVE:Using combination of two cytokines to induce BMSCs differentiating into neuron-like cells directional y, and further to discusse its application in peripheral nerve injury.
METHODS:BMSCs were isolated and purificated from the bone marrow of Wistar rats by using the differential adherence method. Basic fibroblast growth factor and epidermal growth factor were used to induce the BMSCs differentiating into neuron-like cells. The morphological change was observed and the neuronal specific markers were detected by immunohistochemistry technique. The morphological and immunohistological changes were also studied after the induce agent were removed.
RESULTS AND CONCLUSION:With presence of morphological and immunohistochemical features of nerve cells induced by neurotrophic factors, BMSCs exhibited two or more processes that were interconnected as a meshwork;cellnucleus and nucleus could be observed with strong light refraction of cytoplasm. After immunohistochemical staining, neuroln specific enolase, neurofilament protein and synaptophysin protein positive cells were detected. A great amount of cells reversed to their original fibroblast-like morphology, and the expression of the three above-mentioned proteins decreased as the induce agent withdrawn. Our study showed that BMSCs can be induced to differentiate into neuron-like cells, but the transdifferentiation is a short-time reversible phenomenon.

Objective:To study the masseter motor evoked potential(MEP)in patients with sleep bruxism(SB)and in healthy con-trols.Methods:30 subjects with SB and 30 healthy controls were included.MEPs were obtained by transcranial magnetic stimulation (TMS).Tests were done during daytime when the subjects were awake.The data were statistically analysed.Results:In the patients AMT was 55(52,55)%,latency of c-MEP (6.7 ±1.3)ms,the amplitude of c-MEP 0.19(0.15,0.29)mV,latency of r-MEP (2.3 ±0.4)ms,the central conduction time(CCT)4.4(3.3,5.2)ms.In the control subjects AMT was 52(52,55)%,latency of c-MEP (6.4 ±0.7)ms,the amplitude of c-MEP 0.23(0.17,0.28)mV,latency of r-MEP (2.4 ±0.4)ms,CCT 4.0 (3.4,4.4) ms.No significant difference was found between the 2 groups in the measurements evoked by TMS.Conclusion:The MEP after TMS in patients with SB is similar to that of healthy subjects,indicating that the excitability of the cortical motor system is not changed in bruxism subjects,at least when evaluated by TMS.

Tort Liability Law set tougher requirements on the validity and authenticity of medical records,featuring explicit protection of patient rights of informed consent.Based on the changes in the law since its enforcement,the authors studied existing deficiencies of electronic medical records and came up with the following suggestions.Establish sound legal accreditation system for electronic medical records; perfect related laws and regulations to ensure standard application of the electronic medical records; and work out regulations to make medical staff aware of their legal responsibilities when applying electronic medical records.These recommendations will enable electronic medical records better fit the current legal environment onto the track of healthier development.

Objective:To study the influence of all-trans retinoic acid (atRA)on craniomaxillofacial development of C57 mice. Methods:Pregnant C57BL mice were divided into 4 groups(n =5)at gestation day (GD)1 0.Mice in three atRA-induction groups were given atRA of 60,80 and 1 00 mg/kg,respectively.The mice in control group were given the equivalent volume of corn oil.All pregnant mice were sacrificed at GD1 9 and the embryos were collected.Stereo microscope was used to observe the craniomaxillofacial morphology.Standardized radiographs were taken and cephalometric analysis was performed.Results:The embryonic body length and body mass of control group surpassed those of 80 and 1 00 mg/kg atRA groups(P <0.05,P <0.01 ).atRA induced craniomaxillofacial malformations and maldevelopment.The mice induced by atRA exhibited a shorter mandibular body and more retrusive position of max-illary and mandibular(∠NAK and ∠NBD)when compared with their norm(P <0.01 ).Significant decrease in craniofacial length (Op-Rh)was observed in all atRA-induced groups(P <0.01 ).Decreases in cranial vault height(Fp-Os)and cranial vault length(Pa-Na)dimensions were observed in 80 and 1 00 mg/kg atRA groups(P <0.05,P <0.01 ).Conclusion:Exogenous atRA dose-depend-ently induces retardation of craniomaxillofacial morphology in embryo of C57BL mice by inhibition of the sagital and vertical dimension development of the bone.

OBJECTIVETo investigate the effects of all-trans retinoic acid (atRA) on the function of bone morphogenetic protein receptor 2 (BMPR2) expression in embryonic palate.

METHODSCleft palate mice model was established by atRA. On gestation day (GD) 15 and GD 17, the pregnant mice were killed to obtain the embryos from the uteri. The embryonic palates were stained with hematoxylin-eosin, and the remaining sections were used for the immunohistochemistry of BMPR2 detection. Reverse transcription-polymerase chain reaction was performed to detect the expression levels of Bmpr2 mRNA.

RESULTSIn the atRA-treated group, short extensions and failure to fuse with each other were observed. The positive expression of BMPR2 was detected in developing palatal process from GD 15 to GD 17 in the control group. Compared with those of the control group, BMPR2 protein and Bmpr2 mRNA decreased in the atRA-treated group (P<0.05).

CONCLUSIONThe treatment of pregnant mice with retinoic acid produces small palatal shelves in their fetuses and down-regulates BMPR2 expressions.

Animals ; Bone Morphogenetic Protein 2 ; Cleft Palate ; Disease Models, Animal ; Down-Regulation ; Female ; Mice ; Pregnancy ; RNA, Messenger ; Tretinoin

OBJECTIVE To investigate the effect and related mechanism of all￣trans retinoic acid (atRA) exposure on osteogenic differentiation of mouse embryonic palate masenchymal cells MEPM. METHODS MEPM were cultured in osteogenic medium (OM) with atRA 0.1 and 1.0 μmol??L-1 for 1, 3,5, 7 and 9 d. MTT assay was performed to measure the cell viability. The alkaline phosphatase (ALP) activity was measured by chemical colorimetry. The cells were stained using the Von￣Kossa technique to detect the formation of mineralization nodules after 21 d of culture. RT￣PCR was performed to determine expression Runx2, osteopontin, bone morphogenetic protein receptor ( Bmpr) 1b, Bmpr2 and Smad5 mRNA. RESULTS The result of MTT on 9 d showed that, compared with normal control group, the cell viability of OM, OM+atRA 0.1 and 1.0 μmol??L-1 groups decreased significantly(P<0.01). Compared with normal control group, ALP activity of OM group increased significantly(P<0.05), while the ALP activity of OM+atRA 0.1 and 1.0 μmol??L-1 groups was lower than OM group(P<0.05). On 21 d, the Von￣Kossa stai￣ning results showed that the percentage of mineralization nodules formation of OM+atRA 1.0 μmol??L-1 group was (3.65±1.24)%, which was significantly lower than that of OM group(10.33±2.29)%(P<0. 05). On 9 d, the relative Run expression of OM group was the highest one in the four groups, while at￣RA 1.0 μmol??L-1 treatment negatively regulated 20% in comparsion with OM group(P<0.05). Compared with normal control group, the mRNA expression of osteopontin of OM, OM+atRA 0.1 and 1.0 μmol??L-1 groups increased significantly(P<0.05); BDNF mRNA expression of OM group was 2.6￣fold to normal control group, while that of OM+atRA 1.0 μmol??L-1 group was 33% to OM group(P<0.05) . The level of Smad5 mRNA of OM+atRA 1.0 μmol??L-1 group was significantly lower than that of OM group(P<0.05). CONCLUSION atRA Might inhibit osteogenic differentiation of MEPM by down￣regulated the expression of Bmpr1b.

This research was designed to illuminate the change in biomechanical parameters of soft tissue for bite marks on porker limb. The authors used a prefabricate nob to press perpendicularly on porket limb and so to establish bite mark under three forces: 100 N, 200 N and 300 N. After the procedure of biting, the stress-strain relationship and changes in extension of soft tissue were recorded. Meanwhile, the elasticity was measured with a press meter at nine time-points. When bite mark was formed, with the development of stress, the strain of soft tissue increased. But the speed of increment slowed down when stress exceeded some extent. After bite mark was formed, the extension and elasticity of soft tissue decreased with the increase of pressure.
Animals ; Animals, Newborn ; Biomechanical Phenomena ; Bite Force ; Bites, Human ; physiopathology ; Elasticity ; Extremities ; Humans ; Soft Tissue Injuries ; physiopathology ; Stress, Mechanical ; Swine

Objective To explore the clinical efficacy of PRGD composite nerve conduit in the treatment of human large-diameter,critical peripheral nerve defect in upper extremity.Methods From December,2011 to August,2014,19 patients with large-diameter,critical peripheral nerve defect in upper extremity were treated with PRGD composite nerve conduit.The patients were followeded-up periodically.The sensory and motor function recovery,high frequency ultrasound,and EMG were employed to assess the efficacy.Results The patients were followed up for an average time of 12-32 months(mean 21.75 ± 6.86 months),sensory and motor function recovered excellent in 7 patients,satisfactory in 7 patients,tolerable in 3 patients and no improvement in 2 patients were obtained according to the peripheral nerve function assessment standard built by British medical research council,the rate excellent and satisfactory results was 73.7％.Conclusion It is clinically promising to use PRGD composite nerve conduit to repair large-diameter,critical peripheral nerve defect in upper extremity,thus laying a foundation for its further application in clinical practice.

In the field of dental aesthetics,digital aesthetic design plays a crucial role in helping dentists to predict treatment outcomes vis-ually,as well as in enhancing the consistency of knowledge and understanding of aesthetic goals between dentists and patients.It serves as the foundation for achieving ideal aesthetic effects.However,there is no clear standard for this digital process currently in China and abroad.Many dentists lack of systematic understanding of how to carry out digital aesthetic design for treatment.To establish standardized processes for dental aesthetic design and to improve the homogeneity of treatment outcomes,Chinese Society of Digital Dental Industry(CSD-DI)convened domestic experts in related field to compile this consensus.This article elaborates on the key aspects of digital aesthetic data collection,integration steps,and the digital aesthetic design process.It also formulates a decision tree for dental aesthetics at macro level and outlines corresponding workflows for various clinical scenarios,serving as a reference for clinicians.