Arsenic speciation and valence / 中国中药杂志

As arsenic widely exists in nature and has been used in the pharmaceutical preparations, the traditional Chinese medicine(TCM) with arsenic include realgar(As_2S_2 or As_4S_4), orpiment(As_2S_3), and white arsenic(As_2O_3). Among the above representative medicine, the TCM compound formulas with realgar are utilized extensively. Just in Chinese Pharmacopoeia(2020 edition), there are 37 Chinese patent medicines including realgar. The traditional element analysis focuses on the detection of the total amount of elements, which neglects the study on the speciation and valence of elements. The activity, toxicity, bioavailability, and metabolic pathways of arsenic in vivo are closely related to the existence of its form, and different forms of arsenic have different effects on organisms. Therefore, the study on the speciation and valence of arsenic is of great importance for arsenic-containing TCMs and their compound formulas. This paper reviewed four aspects of the speciation and valence of arsenic, including property, absorption and metabolism, toxicity, and analytical assay.

Changing scanning angles on improving finish line trueness of the full crown preparation / 中华口腔医学杂志

Objective: To explore the effect of scanning methods on finish line trueness of the full crown preparation. Methods: The standard full crown preparation model of the right maxillary first molars was prepared by using the maxillary standard resin dentition model. The standard preparation was scanned by imetric scanner and data were used as the true value. CEREC Omnicam and 3Shape TRIOS were used to scan the standard preparation. According to the scanning methods, they were divided into parallel scanning group, occlusal wave scanning group and buccolingual wave scanning group. Each group was scanned repeatedly 6 times. The data were imported into Geomagic Studio 2013 software, and the local finish line image data of the mesial, distal, buccal and lingual regions of the full crown preparation were extracted respectively. Three-dimensional deviation analysis was performed with the reference true value, and the root- mean-square error (RMSE) was the evaluation index of scanning trueness. The statistical method was one-way ANOVA. Results: Parallel scanning group: in general, the RMSE value of complete finish lines of scanner B [(35±6) μm] was significantly lower than that of scanner A [(44±7) μm](P<0.05). After scanner A occlusal wave scanning, the RMSE values of the mesial and distal finish lines [(33±5) and (50±12) μm] were significantly lower than those of parallel scanning group (P<0.05). After buccal and lingual wave scanning, the RMSE values of local finish lines in the mesial, distal, buccal and lingual regions [(37±3), (50±6), (28±6) and (29±8) μm] were significantly lower than those in parallel scanning group [(45±9), (63±7), (38±3) and (40±3) μm] (P<0.05). No significant difference was found in the RMSE values of the mesial, distal, buccal and lingual regions of scanner B between parallel scanning group, occlusal wave scanning group and buccolingual scanning group (P>0.05). Conclusions: The scanning trueness of the full crown preparation finish line obtained by the active triangulation scanning equipment can be improved by changing the scanning method to wave scanning.

The role of the national oral health program in the development of oral health service and related thinkings / 中华口腔医学杂志

Conception of public health was firstly put forward by American professor Winslow. Ensuring and promoting the health of general population is the key connotation for the definition of public health. Oral disease has become a public health problem. Caries which preventable and curable is the most common oral disease and the etiology is also clear. Oral health comprehensive intervention program for children in central and western regions was set up in 2008 by Chinese government. The program included sealing on the first permanent molar and oral health education towards primary school children covering mid-west area. This was the first oral health program invested by government and managed by Chinese Stomatological Association. Six years later, the program was popularized to the whole nation, and renamed as national oral health comprehensive intervention program for children in China. The program had made deep impact on development of oral health service in China. The study tries to analyze the challenges of oral health service through reviewing the background, content, organization and effectiveness of the program, aiming to provide suggestions on policy, financing, system, ability and technology for the future development.

Radicular invaginatus caused by the developmental abnormalities of epithelial root sheath / 中华口腔医学杂志

Epithelial root sheath plays a key role in guiding the development of tooth root. Any problems during its growth can lead to various forms of defects or abnormalities in the development of tooth root. Radicular invaginatus may occur when the epithelial root sheath excessively proliferates and infolds into the dental papilla. In terms of tissue origin and occurrence mechanism, the radicular dens invaginatus is similar to the coronal invaginatus which is led by the proliferation and infolding of enamel organ. However, there had been no consensus on the term and classification of this type of developmental abnormality as well as the relationships among the dens invaginatus, the radicular invaginatus and the palatogingival groove. From the role of epithelial root sheath during root development, the manifestations of root developmental defects and abnormalities will be analyzed. The pathogeny, classification, clinical characteristics of the radicular invaginatus, the relationship with the dens invaginatus and the impact on treatment were specially focused on.

Biological basis and clinical exploration of regenerative endodontic therapy / 中华口腔医学杂志

Regenerative endodontic therapy is a tissue engineering based approach of treatment for endodontic disease. Its purpose is to achieve the regeneration of the pulp-dentin complex, thus to promote root development of the immature permanent tooth with necrotic pulp. Like other treatments based on tissue engineering techniques, the success of regenerative pulp therapy depends on such three elements as seed cells, scaffold materials and growth factors. Since its inception 20 years ago, there have been various terminologies in the literature, with similarities and differences in connotation. The present article summarizes and analyzes the term evolution, biological basis, clinical considerations and future scientific research directions of regenerative endodontics, in order to find out the unsolved scientific problems and to promote the development and standardization of this technique in clinical practice.

Expert consensus on dental caries management / 国际口腔科学杂志·英文版

Dental Caries is a kind of chronic oral disease that greatly threaten human being's health. Though dentists and researchers struggled for decades to combat this oral disease, the incidence and prevalence of dental caries remain quite high. Therefore, improving the disease management is a key issue for the whole population and life cycle management of dental caries. So clinical difficulty assessment system of caries prevention and management is established based on dental caries diagnosis and classification. Dentists should perform oral examination and establish dental records at each visit. When treatment plan is made on the base of caries risk assessment and carious lesion activity, we need to work out patient‑centered and personalized treatment planning to regain oral microecological balance, to control caries progression and to restore the structure and function of the carious teeth. And the follow-up visits are made based on personalized caries management. This expert consensus mainly discusses caries risk assessment, caries treatment difficulty assessment and dental caries treatment plan, which are the most important parts of caries management in the whole life cycle.

Evolution and development: engine-driven endodontic rotary nickel-titanium instruments / 国际口腔科学杂志·英文版

Various engine-driven NiTi endodontic files have been indispensable and efficient tools in cleaning and shaping of root canals for practitioners. In this review, we introduce the relative terms and conceptions of NiTi file, including crystal phase composition, the design of the cutting part, types of separation. This review also analysis the main improvement and evolution of different generations of engine-driven nickel-titanium instruments in the past 20 years in the geometric design, manufacturing surface treatment such as electropolishing, thermal treatment, metallurgy. And the variety of motion modes of NiTi files to improve resistance to torsional failure were also discussed. Continuous advancements by the designers, provide better balance between shaping efficiency and resistance to of NiTi systems. In clinical practice an appropriate system should be selected based on the anatomy of the root canal, instrument characteristics, and operators' experience.

Effects of viscosity and head position on the surface electromyography of the suprahyoid muscles during swallowing / 中华物理医学与康复杂志

Objective:To explore the effect of swallowing fluids of different viscosities in different head positions on the surface electromyography (sEMG) of the suprahyoid muscles.Methods:Twenty healthy adults were asked to swallow 5ml of liquids with 5 different viscosities in 3 different head positions. sEMG signals were recorded from their suprahyoid muscles in real time. The interactions between viscosity, head position and suprahyoid muscle activation were determined using simple effect analysis.Results:Significant head position and viscosity effects were observed. In the head-turning-right or the right head-flexion position, the net amplitude values of the left suprahyoid muscles were significantly higher than those from the right side when swallowing fluid of the same viscosity. Meanwhile, the net amplitude values of the left suprahyoid muscles increased gradually and significantly from the neutral position to the head-turning-right and the right head-flexion positions. When swallowing fluid with a viscosity of 0 to 3, the net amplitude values of the right suprahyoid muscles in the right head-flexion position were significantly lower than in the neutral and right head-flexion positions. With a viscosity of 4 the values of the former were significantly higher than the latter. The net amplitude of the left superhyoid muscle group when swallowing zero-viscosity food in a head-turning-right position was significantly lower than that when swallowing food of viscosity 1 to 4. In the right head-flexion position, the net amplitude of the left superhyoid muscle group when swallowing zero-viscosity food was significantly lower than that when swallowing food of viscosity 2 to 4. When swallowing fluid of viscosity 1 it was also significantly lower than that when swallowing food of viscosity 3 to 4. In the same position, the net amplitude of the right suprhyoid muscle group when swallowing fluid of viscosity 4 was significantly higher than that with a viscosity of 0 to 1. At viscosity 3 it was significantly higher than with a viscosity of 1.Conclusion:Swallowing fluids of different viscosities in different head positions can affect the contraction of the suprahyoid muscles to different degrees.

A case of long-term retention of capsule endoscopy in small intestine / 中国综合临床

Capsule endoscopy is an important method for the diagnosis of small intestinal diseases, and that capsule endoscope retention in the small intestine is the most important and serious complication in the process of this technique.It often occurs in the diseases of intestinal stenosis caused by Crohn′s disease, small intestinal tumor, intestinal tuberculosis and after abdominal surgery.Once capsule endoscope retention occurs, it is necessary to observe the symptoms of intestinal obstruction, to treat the primary disease actively, and it is very important to remove the foreign body by the enteroscopy or surgical intervention timely.

Influence of trueness for local finish lines of a full crown preparation on that of complete finish line / 北京大学学报(医学版)

OBJECTIVE@#To investigate the factors affecting the trueness of finish lines of full crown preparations in digital impressions.@*METHODS@#A full crown preparation of the right maxillary molar was prepared on the standard resin dentition model, the trueness of the finish lines, the full crown preparation in the whole dentition and the isolated full crown preparation were measured respectively. Detection of scanning trueness of the finish lines of the full crown preparation in the whole dentition: (1) Using Imetric scanner to scan the full crown preparation, obtaining STL (Stereo lithographic) format data as the reference true value; (2) Using CEREC Omnicam oral scanner and 3Shape TRIOS oral scanner to scan the full crown preparation, obtaining all the STL format data, import Geomagic Studio 2013 software, extraction of images and data of the complete finish lines or local finish lines (mesial, distal, buccal, lingual) of the full crown preparation, then using the data to 3D Compare Analysis with the reference true value, outputting RMS (root mean square) values which could evaluate the scanning trueness, the lower RMS value was, the lower the trueness was. The detection of scanning trueness of the finish lines of the isolated full crown preparation: (1) the anterior and posterior adjacent teeth of the preparation were removed to establish the model of the isolated full crown preparation; (2) CEREC Omnicam oral scanner and 3Shape TRIOS oral scanner were used to scan the isolated preparations, and each group was repeated 6 times. Data collection and analysis were the same as the first part, that is, detection of scanning trueness of finish lines of the full crown preparation in the whole dentition.@*RESULTS@#In the whole dentition, (1) the RMS value [(44±7) μm] of CEREC Omnicam oral scanner scanning complete finish lines was greater than that of 3Shape TRIOS oral scanner [(35±6) μm](P < 0.05). (2) the RMS values of the mesial [(45±9) μm], buccal [(38±3) μm] and lingual [(40±3) μm] finish lines in CEREC Omnicam oral scanner scanning were all lower than that in distal [(63±7) μm](P < 0.05), and the RMS values in mesial were higher than that in buccal and lingual (P>0.05). The RMS values of 3Shape TRIOS oral scanner scanning mesial and distal finish lines were significantly higher than those of the buccal and lingual side (P>0.05), in which:(45±8) μm in mesial, (50±10) μm in the distal, (33±8) μm in the buccal and (33±6) μm in the lingual side. The RMS value of CEREC Omnicam oral scanner scanning distal finish line was greater than that of 3Shape TRIOS oral scanner (P < 0.05). Without adjacent teeth, (1) the RMS values of the complete finish lines of CEREC Omnicam oral scanner and 3 Shape TRIOS oral scanner were significantly reduced (P < 0.05), including CEREC Omnicam oral scanner (34±3) μm and 3 Shape TRIOS oral scanner (26±4) μm; (2) the RMS values of the buccal and lingual finish lines of CEREC Omnicam oral scanner and 3Shape TRIOS oral scanner showed no significant changes (P>0.05), among which, CEREC Omnicam oral scanner buccal (44±7) μm, lingual (43±3) μm, 3Shape TRIOS oral scanner buccal (29±5) μm, lingual (40±7) μm. The RMS values of CEREC Omnicam oral scanner and 3Shape TRIOS oral scanner were significantly reduced and there was no significant difference between them (P>0.05). CEREC Omnicam oral scanner (32±8) μm and 3Shape TRIOS oral scanner (32±6) μm. The RMS values of the distal finish lines of CEREC Omnicam oral scanner and 3 Shape TRIOS oral scanner also decreased significantly (P < 0.05), and CEREC Omnicam oral scanner (38±3) μm decreased more significantly, similar to 3Shape TRIOS oral scanner (36±1) μm, P>0.05.@*CONCLUSION@#When adjacent teeth exist in the full crown preparation, the mesial and distal parts of the finish line will be blocked by adjacent teeth, which will affect the trueness of the local finish line, and ultimately reduce the trueness of the complete finish line.

Curing method affecting the formation of oxygen inhibition layer on the surface of resin cement / 北京大学学报(医学版)

OBJECTIVE@#To explore the conversion of resin monomer, the change of inorganic component and the influencing factors on the oxygen inhibition layer formed on the cured surface of resin cement.@*METHODS@#Three kinds of resin cement were divided into three groups: (1) light-cured group: RelyX Veneer, NX3 (light-cured), Variolink N; (2) dual-cured group: RelyX U200 Automix, NX3 (dual-cured), Multilink Speed; (3) chemically-cured group, and the above 3 types of dual-cured resin cement cured without illumination could be used as chemically-cured resin cement. Each sample was provided with and without oxygen exposure of two matching surfaces, cured respectively, and the variables of light intensity and illumination time were set in the light-cured group and the dual-cured group. Scanning electron microscopy was used to observe the samples' surface morphology. Energy dispersive spectrometer was used to analyze the samples' composition of surface elements. Confocal Raman spectroscopy was used to measure the monomer conversion of resin cement and to obtain the thickness of the oxygen inhibition layer.@*RESULTS@#(1) On the surface of cured resin cement, the weight percentage of oxygen element in the aerobic side was higher than that in the anaerobic side (P < 0.05), and the weight percentage of inorganic element was lower than that in the anaerobic side (P < 0.05). (2) The surface monomer conversion of the cured resin cement on the aerobic surface was significantly lower than that on the anaerobic surface (P < 0.05), and the surface monomer conversion on the aerobic surface and the anaerobic surface was the lowest in the chemically-cured group (P < 0.05), the dual-cured group was the highest (P < 0.05), and the light-cured group was between them. With the increase of light intensity or illumination time, the surface monomer conversion increased (P < 0.05). (3) The thickness of the oxygen inhibition layer was the thickest in the chemically-cured group [(40.27±2.81) μm](P < 0.05), the thinnest in the dual-cured group [(21.87±5.42) μm](P < 0.05) and light-cured group [(23.73±3.84) μm] was between them. With the increase of light intensity or illumination time, the thickness of the oxygen inhibition layer of resin cement decreased (P < 0.05).@*CONCLUSION@#When resin cement is exposed to oxygen, it will form an oxygen inhibition layer, its surface's inorganic filler is less, the surface monomer conversion is lower. The surface monomer conversion and the thickness of oxygen inhibition layer are affected by curing mode and illumination factors.

Droplets and aerosols in dental clinics and prevention and control measures of infection / 中华口腔医学杂志

Spraying during dental practices can generate quantity of droplets, which transform into droplet nuclei and suspend in the air of clinic in the form of aerosol. Either droplets or aerosols may carry microorganisms and cause air contamination in the hospital, posing potential threat to the health of clinical healthcare staff and patients. The present article summarizes some basic concepts involved in bio-aerosol research and reviews literatures on intervention measures of dental clinic droplet/aerosols to clarify whether there is experimental evidence of aerosol-carrying bacteria in the existing literatures. The aim of this article is to provide evidence for the formulation of guidelines for infection control in dental healthcare practices during the epidemic period of infectious diseases, as well as to provide reference and scientific basis for the management and implementation of infection control measures in daily dental clinical work.

Evaluation of four final irrigation protocols for cleaning root canal walls / 国际口腔科学杂志·英文版

The aim of this study was to compare the efficiency of four final irrigation protocols in smear layer removal and bacterial inhibition in root canal systems. Thirty roots inoculated with Enterococcus faecalis were prepared with ProTaper Universal files. The teeth were disinfected by conventional needle irrigation, sonic agitation using the EndoActivator device, passive ultrasonic irrigation, or an M3 Max file. Teeth with no root canal preparation served as blank controls for the establishment of the infection baseline. Teeth with preparation but no final irrigation served as a post-instrumentation baseline. After the final irrigation, the teeth were sectioned in half. One half of each tooth was examined by scanning electron microscopy (SEM) to assess smear layer removal using a five-point scale. The other half was examined by confocal laser scanning microscopy (CLSM) using the LIVE/DEAD BackLight bacterial viability kit to evaluate the depth of bacterial survival in dentinal tubules. SEM analysis revealed no significant difference in smear layer removal throughout the whole canal among the EA, PUI, and M3 Max groups (P > 0.05). CLSM revealed that PUI achieved the greatest bacterial inhibition depth in the coronal ((174.27 ± 31.63) μm), middle ((160.94 ± 37.77) μm), and apical ((119.53 ± 28.49) μm) thirds of the canal (all P < 0.05 vs. other groups). According to this comprehensive SEM and CLSM evaluation, PUI appears to have the best infection control ability in root canal systems.

Mediated pathways of exosomes uptake by stem cells of apical papilla / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the uptake of exosomes by stem cells from apical papilla (SCAP), thus to provide experimental basis for mechanism of the exosomes endocytosis by SCAP.@*METHODS@#(1) Exosomes of dental pulp stem cells (DPSCs) were isolated by hypercentrifugation combined with ultrafiltration method. The exosomes were identified by transmission electron microscopy, nanoparticle tracking analysis and western blot. (2) PKH-26 membrane labeling technology was used to mark the DPSCs derived exosomes. The labeled exosomes were co-cultured with SCAP at 37 °C as positive control group, and co-cultured with SCAP at 4 °C as the low-temperature treatment group, while the negative control group was set up. (3) Using clathrin-mediated endocytosis inhibitor chlorpromazine (CPZ, 10 μmol /L) as CPZ group, caveolae-mediated endocytosis Genistein (200 μmol/L) as Genistein group, and macropinocytosis inhibitor LY294002 (50 μmol/L) as LY294002 group to treat the SCAP respectively. Solvent control group (DMSO group) was set. Immunofluorescence staining was used to detect the red fluorescence SCAP and flow cytometry was used to analyze the proportion of SCAP labeled with red fluorescence.@*RESULTS@#(1) The bilayer membrane and cup-shaped appearance of representative exosomes were observed. The peak of the size of DPSCs-derived exosomes was at 144 nm. The exosomes expressed exosomal marker proteins TSG101 and CD63, but not GAPDH which was the cellular internal control protein. (2) Immunofluorescence staining showed that after being co-cultured at 37 °C for 6 hours, red fluorescence could be detected in SCAP but it could not be detected after being co-cultured at 4 °C for 6 hours. After endocytosis inhibition, the red fluorescence in SCAP was reduced. Flow cytometry showed that the proportion of SCAP labeled with red fluorescence in positive group was 35.0%, in negative control group was 0.5%, and in solvent control group was 29.7%, in CPZ group, Genistein group and Genistein group were reduced to 13.7%, 16.6%, and 20.9%, respectively.@*CONCLUSION@#SCAP could uptake the DPSCs derived exosomes, and low temperature could inhibit this process. The exosomes uptake of SCAP was mediated by the clathrin endocytosis pathway, caveolae-mediated endocytosis and macropinocytosis pathway.

A discussion on three-dimensional digital imaging technology: application of cone-beam CT in endodontics / 中华口腔医学杂志

Cone-beam CT (CBCT) is a relatively novel digital imaging technology to provide undistorted, three-dimensional information of teeth and surrounding tissues for aiding the diagnosis procedure and improving clinical decision-making. The use of CBCT in endodontics is widely and rapidly increasing. The aim of this review article is to introduce not only the current endodontic applications but also the limitations of CBCT such as artefacts and concerns on radiation dose. Furthermore, the evidenced-based guidelines on the reasonable application of CBCT in endodontics is also presented and re-considered. Clinicians should be more conscious neither to take CBCT as a substitute for two-dimensional radiography nor as a routine examination. With the continuous improvement of equipment and technology, it is urgent to establish and update guidelines in clinical practice. Endodontists should strengthen training, update knowledge, familiarize with CBCT technology and cooperate with radiologists to fulfill their diagnostic responsibilities.

Role of endocytosis in cell surface CXC chemokine receptor 4 expression of stem cells from apical papilla / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the change of cell surface CXC chemokine receptor 4 (CXCR4) expression of stem cells from apical papilla (SCAP) after the inhibition of endocytotic pathway, thus to provide experimental basis for the mechanism of SCAP migration.@*METHODS@#The immunofluorescence analysis was conducted to examine the co-expression of CXCR4 and endocytotic compartments, including early endosomes, recycling endosomes and lysosomes in SCAP. Several Rab proteins were applied as markers of organelles in the endocytotic pathway, including Rab5 for early endosomes, Rab11A for recycling endosomes, and Lamp1 for lysosomes. The co-localization of CXCR4 with these endodontic compartments was further observed by proximity ligation assay (PLA). SCAP was treated with two kinds of endocytotic inhibitors, Blebbistatin and Dynasore, at a concentration of 80 μmol/L, respectively. The conditioning time was 1 hour. Flow cytometry was carried out to evaluate the proportion of SCAP that expressed CXCR4 on cell surface. The data were analysed by analysis of variance (ANOVA).@*RESULTS@#The red staining of CXCR4 on immunofluorescence confocal microscopy predominantly overlapped with the green staining of Rab5 and Rab11A, and partly overlapped with Lamp1. It indicated that most CXCR4 molecules were located in early endosomes and recycling endosomes, and some were located in lysosomes. The PLA results revealed that the co-localizaiton of CXCR4 with endocytotic compartments could be observed in early endosomes, recycling endosomes and lysosomes. According to the results of flow cytometry, the proportion of SCAP that expressed CXCR4 on cell surface was as low as 0.13%±0.10%. After the inhibition of endocytosis by pretreating the cells with the following two inhibitors, Blebbistatin and Dynasore, the percentage of SCAP that positively expressed CXCR4 on cell surface was significantly increased to 13.34%±1.31% in Blebbistatin group and 4.03%±0.92% in Dynasore group (F=16.721, P<0.001). Moreover, the number of SCAP that expressed CXCR4 on cell surface in Blebbistatin group was significantly higher than that in Dynasore group (P<0.001).@*CONCLUSION@#The inhibition of endocytotic pathway could increase the number of SCAP that expressed CXCR4 on cell surface, and provide potency for the migration of SCAP.

Correspondence between advances of dental composites and adhesives and clinical guidelines for direct restorations / 中华口腔医学杂志

The longevity of direct adhesive restoration is related to the restorative materials, the patient and the professional. On one hand, dental composites/adhesives have been modified and developed to fulfill the criteria for clinical application. On the other hand, the clinical guidelines for adhesive restorations have been released and updated accordingly, which would prolong the longevity of restorations. In this commentary, the removal of carious tissues, interface preparation for bonding and application of adhesives are emphasized. The administrative measures for registration and clinical evaluation criteria for adhesive restorative material are also introduced.

Effect of silane coupling agent on composite-composite bond strength: an in vitro study / 中华口腔医学杂志

Objective@#To investigate the effect of silane coupling agent on composite-composite bond strength, and to provide experimental basis for improving composite-composite bond strength clinically.@*Methods@#Self-etching adhesive Clearfil SE Bond (CSE) and silane-containing universal adhesive Single Bond Universal (SBU) were used as adhesives. A silane coupling agent (RelyX ceramic primer) was tested. P60 resin composite blocks were prepared and divided into 4 groups according to whether silane coupling agent was applied or the type of the adhesives: CSE group, in which CSE was applied as an adhesive; Silane + CSE group, in which the surface was treated with silane coupling agent followed by CSE; SBU group, in which SBU was applied as an adhesive; Silane+ SBU group, in which the surface was treated with silane coupling agent followed by SBU, then filling a new composite. All the composite blocks were cut into about twenty 1 mm×1 mm×14 mm samples to detect the micro-tensile bond strength. Fractographic analysis were performed under a three-dimensional laser scanning microscope. The micro-tensile bond strength data were analyzed statistically by one-way ANOVA and the failure pattern data were analyzed statistically by Chi-square test.@*Results@#Silane + SBU group [(69.6 ± 3.3) MPa] showed a significantly higher micro-tensile bond strength than the other groups (P<0.05). Silane+CSE group showed a significantly higher micro-tensile bond strength [(63.9±3.7) MPa] than CSE group [(55.7±4.2) MPa] and SBU group [(55.4±4.0) MPa] (P<0.05); There was no significant difference in micro-tensile bond strength between the SBU group and the CSE group (P>0.05). Failure patterns in the 4 groups were adhesive failure, cohesive failure and mixed failure. There was no significant difference in the proportion of adhesive failure between the Silane+CSE group and the Silane+SBU group, and the proportion of adhesive failure in these two groups were significantly less than that in the CSE and the SBU group (P<0.05).@*Conclusions@#Silane coupling agent pretreatment could improve composite-composite bond strength, however, the bond strength could not be higher when silane was mixed with adhesives in one bottle.

The effects of the inter-stimulus interval in magnetic stimulation on astrocyte migration and its mechanism / 中华物理医学与康复杂志

Objective To examine the effect of the inter-stimulus interval (ISI) in magnetic stimulation (MS) on astrocyte migration and its related mechanism.Methods Cultured astrocytes were treated with intermittent MS with intervals of 1,5 and 10 seconds.The PEA-15 inhibitor BisI (10 μmol/ml) and the ERK1/2 inhibitor U0126 (10 μmol/ml) were administered and cell migration assays evaluated the astrocytes' migration.The expression of phosphorylated ERK1/2 and PEA-15 was detected using Western blotting.Results The 1 second interval significantly facilitated astrocyte migration,the phosphorylation of PEA-15 and ERK1/2,and the expression of MMP-9 (browse matrix metalloproteinase-9).The addition of Bis I significantly reduced the production of phosphorylated ERK1/2 and MMP-9,as well as astrocyte migration induced by MS.In addition,pretreatment with U0126 also significantly decreased the astrocyte migration induced by MS.Conclusion 1s-ISI MS can induce PEA-15 activation and subsequently lead to ERK1/2 phosphorylation and upregulation of MMP-9,which may contribute to the migration of astrocytes.

Mechanism of microRNA-106a promoting invasion of breast cancer MDA-MB-231 cells / 中国病理生理杂志

AIM:To investigate the possible mechanism of microRNA-106a promoting the invasion of human breast cancer MDA-MB-231 cells. METHODS:The efficiencies of transfection with microRNA-106a inhibitor and mi-croRNA-106a mimic by liposome were detected by qPCR. The mRNA and protein expression levels of tissue inhibitor of metalloproteinase 2 (TIMP-2), matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9) in the MDA-MB-231 cells transfected with microRNA-106a mimic were detected by qPCR and Western blot. The effect of microRNA-106a on the invasion ability of MDA-MB-231 cells was measured by Transwell assay. The luciferase reporter assay was used to detect the regulatory effect of microRNA-106a on the TIMP-2 pathway. RESULTS:In the MDA-MB-231 cells, the ex-pression level of microRNA-106a decreased at 48 h after transfection with microRNA-106a inhibitor (P<0.05), and the expression level of microRNA-106a increased at 48 h after transfection with microRNA-106a mimic (P<0.05). The mi-croRNA-106a inhibitor decreased the invasion ability of MDA-MB-231 cells in vitro (P<0.05). The microRNA-106a mim-ic down-regulated the expression of TIMP-2 and up-regulated the expression of MMP2 and MMP9 (P<0.05) in the MDA-MB-231 cells. The microRNA-106a inhibitor enhanced the luciferase activity of the reporter plasmids containing the 3'-un-translated region of TIMP-2 gene (P<0.05), while the microRNA-106a mimic decreased the luciferase activity of the re-porter plasmid (P<0.05). CONCLUSION:High expression of microRNA-106a promotes the invasion ability of breast cancer MDA-MB-231 cells in vitro, which may be related to the inhibition of TIMP-2 pathway. MicroRNA-106a plays an important role in the invasion of breast cancer MDA-MB-231 cells.