Comparison of the secretory related molecules expression in stem cells from the pulp of human exfoliated deciduous teeth and dental pulp stem cells / 中华口腔医学杂志

Objective@#To compare the general biological characteristics and the expressions of proteins involved in secretion in stem cells from the pulp of human exfoliated deciduous teeth (SHED) and dental pulp stem cells (DPSC).@*Methods@#SHED and DPSC were cultured and collected at passage 4 (P4) and P7. The submandibular gland epithelial and interstitial cells were cultured with tissue culture method. The cell morphology was observed using a phase contrast microscope. Flow cytometry was used to detect stem cell surface markers. Cell counting kit-8 (CCK-8) and IncuCyte ZOOM were used to evaluate cell proliferation. Quantitative real-time PCR (qPCR) was performed to examine the mRNA expressions of proteins involved in fluid and protein secretion.@*Results@#P4 and P7 SHED and DPSC were spindle-shaped. There was no difference in cell morphology among the 4 group cells. P4 and P7 SHED and DPSC expressed CD29, CD44, CD73, and CD90, the mesenchymal stem cell markers, while, CD49f and CD117, the epithelium markers were undetected. There was no difference in cell proliferation among the 4 group cells. Compared with P4 SHED, the expressions of muscarinic cholinergic receptor 1 (MR1), MR3, aquaporin 5 (AQP5), β1-adrenoceptor (β1-AR), α-amylase, and mucin 5B in SHED were not different, while β2-AR expression was decreased (P<0.05). Compared with P4 DPSC, the expressions of MR3, β2-AR, and α-amylase in P7 DPSC were not different, while, the expressions of MR1, AQP5, β1-AR, and mucin 5B were decreased (P<0.05). Compared with primary cultured submandibular gland epithelial cells and gland tissues from a child, the expressions of proteins involved in secretion were all decreased. Compared with submandibular epithelial cells from adults, the expression of AQP5 in P4 DPSC was decreased (P<0.05), while other proteins were not different. The expressions of AQP5, β1-AR, α-amylase and mucin 5B in P7 DPSC were increased (P<0.05), while other proteins were not different. In P4 and P7 DPSC, all the protein expression levels were decreased, compared with those in submandibular gland tissues (P<0.01).@*Conclusions@#Compared with DPSC, SHED have stable growth and the expressions of protein involved fluid and protein secretion are low. Based on its extensive sources and easy separation, SHED can be used as the ideal seed cell for salivary gland tissue engineering and the treatment of salivary gland hypofunction, and the P4 to P7 SHED can be used for experimental study.

Development of human embryonic stem cell platforms for human health-safety evaluation / 北京大学学报(医学版)

SUMMARY Thehumanembryonicstemcells(hESCs)serveasaself-renewable,genetically-healthy, pluripotent and single source of all body cells,tissues and organs.Therefore,it is considered as the good standard for all human stem cells by US,Europe and international authorities.In this study,the standard and healthy human mesenchymal progenitors,ligament tissues,cardiomyocytes,keratinocytes,primary neurons,fibroblasts,and salivary serous cells were differentiated from hESCs.The human cellular health-safety of NaF,retinoic acid,5-fluorouracil,dexamethasone,penicillin G,adriamycin,lead ace-tate PbAc,bisphenol A-biglycidyl methacrylate (Bis-GMA)were evaluated selectively on the standar-dized platforms of hESCs,hESCs-derived cardiomyocytes,keratinocytes,primary neurons,and fibro-blasts.The evaluations were compared with those on the currently most adopted cellular platforms.Parti-cularly,the sensitivity difference of PM2.5 toxicity on standardized and healthy hESCs derived fibroblasts, currently adopted immortalized human bronchial epithelial cells Beas-2B and human umbilical vein endo-thelial cells (HUVECs)were evaluated.The results showed that the standardized hESCs cellular plat-forms provided more sensitivity and accuracy for human cellular health-safety evaluation.

Expression characteristics of epithelial markers in human embryonic stem cells differentiating into keratinocytes / 北京大学学报(医学版)

Objective:To differentiate human embryonic stem cells ( hESCs ) into keratinocytes ( K-hESCs) and analyse the expression characteristics of biomarkers of K-hESCs.Methods: The hESCs of line H9 were seeded on matrigel in mTeSR1 medium.The hESCs were directly differentiated into kerati-nocytes in epithelial differentiation medium with bone morphogenetic protein 4, retinoic acid and N2 sup-plement.The karyotype of K-hESCs was analyzed, comparing the gene expression differences of K-hESCs with human gingival epithelial cells (HGECs), human immortalized oral epithelial cells (HIOECs) and HaCaT by Real-time PCR.Molecular characteristics of the cell differentiation were observed throughout the process by immunocytochemical techniques.Results:H9-hESCs were successfully differentiated into the cells that exhibited characteristics of keratinocytes in epithelial differentiation medium.The karyotype of K-hESCs was 46, XX; and the keratinocyte gene p63 expression in K-hESCs was significantly lower than that in HaCaT ( P0.05 ) .Conclusion: H9-hESCs could be directly differentiated into K-hESCs.The gene expression of K-hESCs was similar to that of epithelial cells in the early stage of monolayer cells differentiation with high proliferative activity.

Effects of mineral trioxide aggregate on the proliferation and differentiation of human pulp cells from primary and permanent teeth / 华西口腔医学杂志

<p><b>OBJECTIVE</b>This study aims to investigate the effects of mineral trioxide aggregate (MTA) and calcium hydroxide on proliferation and differentiation of human pulp cells from primary and permanent teeth.</p><p><b>METHODS</b>Cell proliferation was detected by methyl thiazolyl tetrazolium (MTT) assay. The mRNA expression levels of dentinogenesis-related factors, including alkaline phosphatase (ALP) and dentin sialophosphoprotein (DSPP), and odontoclastogenesis-related factors, such as osteo- protegerin (OPG) and receptor activator of NF-κB ligand (RANKL), were determined by real time polymerase chain reac- tion (PCR).</p><p><b>RESULTS</b>Primary and permanent pulp cells treated with calcium hydroxide exhibited significantly lower proli- feration rates than the control cells (P<0.01). By contrast, the MTA-treated group showed significantly higher proliferation rates than the control group (P<0.01). Real time PCR results showed that calcium hydroxide-treated primary pulp cells exhi- bited significantly decreased ALP, DSPP, and OPG expression compared with the control group (P<0.01). Conversely, the MTA-treated group displayed significantly increased ALP, DSPP, and OPG expression (P<0.01). Calcium hydroxide-treated primary pulp cells also exhibited significantly upregulated RANKL expression (P < 0.01); by contrast, MTA-treated cells did not show any change in RANKL expression (P>0.05). Likewise, MTA-treated permanent pulp cells showed significantly upregulated ALP and DSPP expression (P < 0.01). However, the calcium hydroxide-treated group remained almost the same as the control group (P > 0.05). Neither MTA nor calcium hydroxide affected OPG and RANKL expression in per- manent pulp cells (P > 0.05).</p><p><b>CONCLUSION</b>MTA is more suitable as a pulp-capping agent, particularly in primary teeth, than calcium hydroxide.</p>

Overview of the vascular interventional surgery robot / 中国医疗器械杂志

In vascular invasive surgery procedures, because doctors suffered from a large number of X-ray radiation, and it is difficult to manipulate catheter, so vascular interventional robot has been rapidly developed. On the basis of analysis of vascular surgical intervention process, key technologies of vascular interventional surgical robots are provided. The image navigation system, the mechanical structure, control systems and force feedback are also analyzed.

Design and experiment of guide wire tele-manipulation system based on laser mouse sensor / 中国医疗器械杂志

In order to realize the guide wire tele-manipulation in intervention operation, a method for guide wire motion detection with laser mouse sensor is proposed and experiments are carried out. On that basis, a guide wire tele-manipulation system which consists of guide wire detection appliance, guide wire manipulation appliance, and master slave type software is designed. Experiments are conducted on the system and acquired needed data, so that relationships between operating time and the distance from guide wire tip to destination and the angle are analyzed. The results validate the feasibility of the system and provide good foundation for future research.

Human gingival epithelial cells cultured by a combined method of serum containing medium and serum free medium / 北京大学学报(医学版)

Objective: To search for a simple and rapid cell culture method for human gingival epithelial cells with a high success rate. Methods:Culture medium containing serum has been proved to have the ability of accelerating the early adhesion of human gingival tissue blocks, and the migration of gingival epithelial cells from the rim of the blocks. By means of this, we introduced the serum containing DMEM to the cell culture medium within the first 7-10 days, and changed with serum free cell culture medium to accelerate the mitosis, proliferation, and migration of the gingival epithelial cells, which had moved out from the tissue blocks. Using the combined method, cells were identified by the method of morphology, immunohistochemistry and analysis of the cell growth curve, as well as SEM. Compared study of the effects on the cell growth between combined method and serum containing DMEM or serum free EpiLife culture method was conducted. Results: Cells were harvested within 17-22 days. Primary culture success rate was 90.6%. Cultured cells were slabstone shaped. Immunohistochemistry analysis of keratin antibody showed a positive result. The cells had stronger ability of migration and proliferation in the serum free cell culture medium compared with that in the serum medium. Conclusion: This method can culture the gingival epithelium cells conveniently with accelerated speed.

Effects of estradiol on proliferation and metabolism of rabbit mandibular condylar cartilage cells in vitro / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the effects in vitro of 17 beta-estradiol (E2) on the proliferation and metabolism of rabbit mandibular condylar cartilage cells.</p><p><b>METHODS</b>Chondrocytes were derived from neonatal rabbit mandibular condylar cartilage using a modified enzyme method. 17 beta-estradiol was added to the culture medium in a variety of concentrations. Cell growth and DNA, collagen, and proteoglycan synthesis were used as indicators of proliferation and differentiation of condylar chondrocytes. These were measured by cell number, 3H-proline and 35S-incorporation, respectively.</p><p><b>RESULTS</b>E2 increased cell number and 3H-thymidine incorporation at 10(-8) to 10(-10) mol/L, and 10(-8) to 10(-11) mol/L in a dose-dependent manner, peaking at 10(-8) mol/L and 10(-9) mol/L, respectively. However, further increase in the concentration of estradiol caused inhibition of both cell number and 3H-thymidine incorporation, and this was significant at 10(-6) mol/L. The effect of E2 on proteoglycan synthesis was similar; the maximum stimulating effect was at 10(-8) mol/L, and inhibition was significant at 10(-6) mol/L. There was no obvious stimulatory effect of E2 on 3H-thymidine incorporation observed.</p><p><b>CONCLUSIONS</b>Estradiol affects condylar chondrocyte cell growth, DNA, and proteoglycan synthesis in a biphasic manner depending on its concentration. This indicates that estrogen may be important in the proliferation and differentiation of mandibular condylar chondrocytes, and could be relevant to some aspects of certain temporomandibular joint diseases by modulating the function of the chondrocytes.</p>

An antimetastatic study of Arg-Asp (RD) on salivary adenoid cystic carcinoma in vivo / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To test the antimetastatic effects of Arg-Asp (RD) on salivary adenoid cystic carcinoma (SACC-LM) in vivo.</p><p><b>METHODS</b>RD was administered orally to experimental metastasized nude mice. The pulmonary metastatic foci number and survival were determined to assay the antimetastatic effects of RD.</p><p><b>RESULTS</b>30 mg/kg, 120 mg/kg of RD demonstrated an inhibitory effect on the pulmonary metastatic foci formation. All of the tested dosages (7.5 mg/kg, 30 mg/kg, 120 mg/kg) of RD prolonged the survival.</p><p><b>CONCLUSIONS</b>Oral administration of RD has a antimetastatic effect on SACC-LM. RD is low toxicity.</p>

An in vitro study of trophic activity on facial motoneuron by soluble substances derived from Schwann cells of rats / 北京大学学报(医学版)

Objective: To compare trophic effects of soluble substances derived from Schwann cells (SC) of neonatal and Wallerian degenerating segments of rats on facial motoneuron (FMN) cultures. Methods: Serum-free conditioned media of Schwann cell cultures (SC-CM) from facial and sciatic nerves of neonatal and Wallerian degenerating segments in adult rats were individually collected and concentrated by ultra-filtration with molecular weight cut-off at 30 000 and 10 000. The growth activities of FMNs in vitro were determined by means of MTT assay under the condition of serum-free medium added with different components of concentrated SC-CMs (SC-CMCs). The absorbance values were then statistically analyzed. Results: Survival and growth rate of FMN cultures in four kinds of SC-CMCs were significantly higher than that in media both with serum and non-serum and the difference between SC-CMCs was not statistically significant (P>0.05). Neurotrophic molecules were predominantly protein or peptide components with relative molecular weight larger than 30 000 and their trophic activity was positively related to total protein concentration in SC-CMCs. Conclusion: There were soluble trophic molecules with relative molecular weight larger than 30 000 for survival and neurite growth of FMN cultures in media with SC-CMCs derived from facial and sciatic nerves of neonatal rats and with SC-CMCs derived from Wallerian degenerating facial and sciatic nerves of adult rats. It might be reasonable to choose SC from sciatic nerves of rats on account of the findings from SC cultures on facial motoneurons.