Chinese stomatology education mode is different from foreign oral education mode,with its own characteristics and some deficiencies.By comparing to the mature oral ( dental ) medical education system,we can learn from the successful experience from American modern oral medical education mode while preserving their advantages to carry forward the Chinese stomatology education.For this purpose,we analyze the academic structure,curriculum,teaching methods,continuing education,basic training,clinical practice,career prospects between Sino-US oral medical education system.Some suggestions on educative reform were also made.

Objective To investigate the application value of the ultrasonic elastic tissue dispersion quantitative analysis technique in different stages of subacute thyroiditis (SAT).Methods One hundred and forty-four SAT lesions detected from 81 patients were enrolled in the patient group.They were further divided into three subgroups,including acute group (group Ⅰ),medium group (group Ⅱ) and recovery group (group Ⅲ).Another 59 healthy volunteers were collected as control group.All the participants accepted conventional ultrasound and elastographic examinations.Eleven parameters were obtained by the tissue dispersion quantitative analysis software.These parameters were compared between groups and among subgroups by ANOVA.The correlation between all the parameters and the course of SAT were analyzed by Spearman and Multiple linear regression methods.Results Between groups and among subgroups,the complexity (COMP) and correlation (CORR) were not statistically different(all P ＞0.05).Differences of kurtosis (KURT) and angular secon moment (ASM) among the three subgroups were not significant (all P ＞0.05).Differences between groups and among subgroups were significantly different among the value of all the other seven indexes (all P ＜0.01).Moreover,they were all correlated with the clinical staging,with the highest coefficient in area ration of low-strain region (％ AREA)(r =-0.881).Regression model was constructed and only ％ AREA was selected into the regression equation.ROC curves were constructed to estimate the clinic value of ％ AREA in staging patients of SAT,the areas under ROC curves were0.986(group Ⅰ vs group Ⅱ-Ⅲ) and 0.988 (group Ⅰ-Ⅱ vs group Ⅲ[) for ％AREA,respectively.Conclusions The tissue dispersion quantitative analysis technique is helpful in estimating the stiffness of thyroid in patients with SAT.

Objective:To investigate the differences regarding expression of apoptosis related factors among tumor tissue ,adja‐cent normal bowel tissue ,and distal normal bowel tissue of nude mice with transplanted human colorectal cancer .Methods:Or‐thotopic tumor models of transplanted human colorectal cancer were established in 12 BALB/C nude mice ,and the mice were killed eight weeks after transplantation .The expression levels of apoptosis related factors such as signal transducer and activa‐tor of transcription 3(STAT3) ,Bcl‐2 ,Survivin ,caspase‐9 ,caspase‐8 and caspase‐3 ,in tumor tissues ,adjacent (1 cm distance from tumor tissue) normal bowel tissues ,and distal (>5 cm distance from tumor tissue) normal bowel tissues ,were assessed by RT‐PCR and immunohistochemistry assay .Results:The mRNA expression of STAT3 and Survivin ,as well as the protein expression of STAT3 ,Bcl‐2 and Survivin in tumor tissue were higher than those in adjacent normal bowel tissue and distal nor‐mal bowel tissue ,as results of RT‐PCR and immunohistochemistry assay showed ,while the protein expression of caspase‐8 , caspase‐9 and caspase‐3 in tumor tissue were lower than those in adjacent normal bowel tissue and distal normal bowel tissue . And all the differences were statistically significant(all P<0 .05) .The protein expression of STAT3 and the mRNA expression of Bcl‐2 in adjacent normal bowel tissue were higher than those in distal normal bowel tissue .Both the differences were statisti‐cally significant(both P<0 .05) .The other genes showed no statistically significant difference between adjacent normal bowel tissue and distal normal bowel tissue regarding expression level .There was no statistically significant difference regarding Bcl‐2 expression between tumor tissue and adjacent normal bowel tissue .Conclusions:The apoptosis status in tissue of transplanted human colorectal cancer was significantly different from that in normal tissue .The expression levels of STAT3 and Bcl‐2 in ad‐jacent normal bowel tissue were higher than those in distal normal bowel tissue .This may be one of the reasons for tumor re‐currence and metastasis .However ,further researches are needed for confirmation .

Regenerative therapy holds great promise in the development of cures of some untreatable diseases such as cardiovascular diseases, and pluripotent stem cells (PSCs) including induced PSCs (iPSCs) are the most important regenerative seed cells. Recently, differentiation of human PSCs into functional tissues and cells in vitro has been widely reported. However, although porcine reports are rare they are quite essential, as the pig is an important animal model for the in vitro generation of human organs. In this study, we reprogramed porcine embryonic fibroblasts into porcine iPSCs (piPSCs), and differentiated them into cluster of differentiation 31 (CD31)-positive endothelial cells (ECs) (piPSC-derived ECs, piPS-ECs) using an optimized single-layer culture method. During differentiation, we observed that a combination of GSK3β inhibitor (CHIR99021) and bone morphogenetic protein 4 (BMP4) promoted mesodermal differentiation, resulting in higher proportions of CD31-positive cells than those from separate CHIR99021 or BMP4 treatment. Importantly, the piPS-ECs showed comparable morphological and functional properties to immortalized porcine aortic ECs, which are capable of taking up low-density lipoprotein and forming network structures on Matrigel. Our study, which is the first trial on a species other than human and mouse, has provided an optimized single-layer culture method for obtaining ECs from porcine PSCs. Our approach can be beneficial when evaluating autologous EC transplantation in pig models.

Regenerative therapy holds great promise in the development of cures of some untreatable diseases such as cardiovascular diseases, and pluripotent stem cells (PSCs) including induced PSCs (iPSCs) are the most important regenerative seed cells. Recently, differentiation of human PSCs into functional tissues and cells in vitro has been widely reported. However, although porcine reports are rare they are quite essential, as the pig is an important animal model for the in vitro generation of human organs. In this study, we reprogramed porcine embryonic fibroblasts into porcine iPSCs (piPSCs), and differentiated them into cluster of differentiation 31 (CD31)-positive endothelial cells (ECs) (piPSC-derived ECs, piPS-ECs) using an optimized single-layer culture method. During differentiation, we observed that a combination of GSK3β inhibitor (CHIR99021) and bone morphogenetic protein 4 (BMP4) promoted mesodermal differentiation, resulting in higher proportions of CD31-positive cells than those from separate CHIR99021 or BMP4 treatment. Importantly, the piPS-ECs showed comparable morphological and functional properties to immortalized porcine aortic ECs, which are capable of taking up low-density lipoprotein and forming network structures on Matrigel. Our study, which is the first trial on a species other than human and mouse, has provided an optimized single-layer culture method for obtaining ECs from porcine PSCs. Our approach can be beneficial when evaluating autologous EC transplantation in pig models.

Animals ; Bone Morphogenetic Protein 4 ; Cardiovascular Diseases ; Endothelial Cells ; Fibroblasts ; Humans ; In Vitro Techniques ; Induced Pluripotent Stem Cells ; Lipoproteins ; Mesoderm ; Methods ; Mice ; Models, Animal ; Pluripotent Stem Cells ; Swine

The clustered regularly interspaced short palindrome repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system is a versatile genome editing tool with high efficiency. A guide sequence of 20 nucleotides (nt) is commonly used in application of CRISPR/Cas9; however, the relationship between the length of the guide sequence and the efficiency of CRISPR/Cas9 in porcine cells is still not clear. To illustrate this issue, guide RNAs of different lengths targeting the EGFP gene were designed. Specifically, guide RNAs of 17 nt or longer were sufficient to direct the Cas9 protein to cleave target DNA sequences, while 15 nt or shorter guide RNAs had loss-of-function. Full-length guide RNAs complemented with mismatches also showed loss-of-function. When the shortened guide RNA and target DNA heteroduplex (gRNA:DNA heteroduplex) was blocked by mismatch, the CRISPR/Cas9 would be interfered with. These results suggested the length of the gRNA:DNA heteroduplex was a key factor for maintaining high efficiency of the CRISPR/Cas9 system rather than weak bonding between shortened guide RNA and Cas9 in porcine cells.
Base Sequence ; Complement System Proteins ; CRISPR-Cas Systems ; DNA ; Genome ; Nucleotides ; RNA, Guide ; Swine

Objective : To investigate the correlation between the expression level of YTHDF1 in oral squamous cell carcinoma ( OSCC) and clinicopathologic features and its potential prognostic value． Methods : The expression of YTHDF1 in 132 OSCC tissues and 66 paracancerous tissues was detected by immunohistochemistry (IHC) ，and the expression of YTHDF1 protein in OSCC cell lines was detected by Western blot．The correlation between YTHDF1 and clinicopathological features was analyzed by chi-square test．Kaplan-Meier and Cox factors were used to analyze the factors affecting the survival time of the patients and draw the survival curves of the YTHDF1 gene to evaluate its potential clinical significance. Results : The expression of YTHDF1 in OSCC tissues was higher than that in para- cancerous tissues (P＜0. 001) ，and the expression of YTHDF1 protein increased in OSCC cell lines compared with normal oral epithelial keratinocytes (P ＜0. 001) ．The expression of YTHDF1 was correlated with the TNM stage and T stage of patients with OSCC (P＜0. 05) ，and the patients with high expression of YTHDF1 had a shorter sur- vival time compared with those with low expression (P ＜0. 001) ． Conclusion High expression of YTHDF1 may be associated with poor patient prognosis and YTHDF1 may be able to serve as a target for OSCC treatment.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.