Effect of cavity disinfection protocols on microtensile bond strength of universal adhesive to dentin / Efecto de los protocolos de desinfección de cavidades en la fuerza de adhesión microtensil del adhesivo universal a la dentina

Abstract The purpose of this study was to compare the effect of different disinfection protocols of dentin on bond strength of an MDP-containing universal adhesive. Twelve extracted mandibular third molars were separated horizontally at the mid-coronal of crown to get smooth and sound dentin surfaces using low-speed diamond saw. The teeth were randomly fallen into four groups: chlorhexidine (CHX), ozone, Er,Cr:YSGG laser irradiation (LASER) and no treatment (control). After cavity disinfection application, a universal adhesive (G-Premio Bond) was applied to the surface of dentin according to self-etch mode as instructed by the manufacturer. After incremental built-up of composite resin (Charisma Smart), the specimens were immersed in distilled water at 37°C for 24h. Dentin/composite beams with 1 mm² cross sectional area were produced and micro-tensile bond strength (µTBS) was applied on these beams (n=20). Failure mods were determined under a stereomicroscope at ×40. The resin penetration of samples stained with Rhodamine B fluorochrome dye was examined with a confocal laser scanning microscope. Statistical analysis was performed with SPSS-22. Test results were analyzed using One-way Anova and Tukey HSD Post-Hoc tests (p0.5). All applications of cavity disinfection procedures decreased the µTBS of the resin-dentin interface.

Resumen El propósito de este estudio fue comparar el efecto de diferentes protocolos de desinfección de la dentina sobre la fuerza de unión de un adhesivo universal que contiene MDP. Doce terceros molares mandibulares extraídos se quebraron horizontalmente en la mitad de la corona para obtener superficies de dentina lisas y sólidas utilizando una sierra de diamante de baja velocidad. Los dientes se dividieron aleatoriamente en cuatro grupos: clorhexidina (CHX), ozono, irradiación con láser Er,Cr:YSGG (LASER) y ningún tratamiento (control). Después de la aplicación de la desinfección de la cavidad, se aplicó un adhesivo universal (G-Premio Bond) a la superficie de la dentina según el modo de autograbado indicado por el fabricante. Después de la obturación con resina compuesta (Charisma Smart), las muestras se sumergieron en agua destilada a 37°C durante 24h. Se produjeron porciones de dentina/resina con un área de sección transversal de 1 mm² y se aplicó una fuerza de adhesión microtensile (µTBS) (n=20). Los modos de falla se determinaron bajo un microscopio estereoscópico a ×40. La penetración de la resina de las muestras teñidas con colorante fluorocromo rodamina B se examinó con un microscopio de barrido láser confocal. El análisis estadístico se realizó con SPSS-22. Los resultados de las pruebas se analizaron utilizando las pruebas post-hoc Anova unidireccional y Tukey HSD (p0.5). Todas las aplicaciones de procedimientos de desinfección de cavidades redujeron el µTBS de la interfaz resina-dentina.

Uptake and trafficking of different sized PLGA nanoparticles by dendritic cells in imiquimod-induced psoriasis-like mice model

Psoriasis is an autoimmune inflammatory disease, where dendritic cells (DCs) play an important role in its pathogenesis. In our previous work, we have demonstrated that topical delivery of curcumin-loaded poly (lactic-

Layered dissolving microneedles as a need-based delivery system to simultaneously alleviate skin and joint lesions in psoriatic arthritis

Psoriatic arthritis (PsA) is a complicated psoriasis comorbidity with manifestations of psoriatic skin and arthritic joints, and tailoring specific treatment strategies for simultaneously delivering different drugs to different action sites in PsA remains challenging. We developed a need-based layered dissolving microneedle (MN) system loading immunosuppressant tacrolimus (TAC) and anti-inflammatory diclofenac (DIC) in different layers of MNs,

Comparison of the interdiffusion of four self-etching adhesives in resin-aged glass-fiber-reinforced composites / 口腔疾病防治

Objective@#To observe the permeability of four kinds of self-etching adhesives in aged glass-fiber-reinforced composite (GFRC).@*Methods@#After light polymerization following the manufacturers’ instructions, a total of 80 pieces of bisphenol-A-glycodal-methacrylate (Bis-GMA)+ polymethyl methacrylate (PMMA) based GFRC were randomly divided into two main groups: test group and control group, each group was then divided into four subgroups with 10 samples for each subgroup. While the test group was conducted to be aged through thermocycling at 5 ℃/55 ℃, the control group remained fresh. After the addition of a fluorescent dye (rhodamine-B-isothiocyanate), four self-etching adhesives AdperEasy One (AEO), S 3 BOND (S 3B), Tetric N-Bond Self-Etch (TNB), G-Bond (GB) were correspondently applied to the test and control groups and were light polymerized. Specimens were sectioned using hard tissue cutting and grinding system. Slices from each subgroup were observed under a confocal laser scanning microscope, the depth of dye permeation (DDP) under the surface of GFRC in each group was measured and the Results were statistically analyzed.@*Results@#The DDP of AEO was the deepest (32.58 ± 6.06) μm, and that of TNB was the shallowest (6.19 ± 1.38)μm among the four self-etching adhesive subgroups in the control group. The order of each group was AEO > GB > S 3B > TNB. The DDP of the four subgroups in the test group was significantly shallower than that in the control group (P < 0.05). The change in GB was the greatest (9.05 ± 2.35)μm/(28.93 ± 5.32)μm. In the test group, the DDP in AEO was the deepest (28.42 ± 5.32)μm, and the DDP in TNB was shallowest (1.93 ± 0.22)μm again. The order of each group was AEO > S 3B > GB > TNB. In the test group, while the layer of fluorescent dye of AEO and S 3 B could still be seen distinctly, that of TNB and GB was hard to recognize. @*The DDP of AEO was the deepest (32.58 ± 6.06) μm, and that of TNB was the shallowest (6.19 ± 1.38)μm among the four self-etching adhesive subgroups in the control group. The order of each group was AEO > GB > S 3B > TNB. The DDP of the four subgroups in the test group was significantly shallower than that in the control group (P < 0.05). The change in GB was the greatest (9.05 ± 2.35)μm/(28.93 ± 5.32)μm. In the test group, the DDP in AEO was the deepest (28.42 ± 5.32)μm, and the DDP in TNB was shallowest (1.93 ± 0.22)μm again. The order of each group was AEO > S 3B > GB > TNB. In the test group, while the layer of fluorescent dye of AEO and S 3 B could still be seen distinctly, that of TNB and GB was hard to recognize. @#The self-etching adhesives of AEO and S 3 B still have good permeation effect in this kind of aged GFRC, which can help to establish a good bond between these aged GFRC and the subsequent repair of composite resin.

Effects of Serum and its components on the biofim formation of Pseudomonas aeruginosa / 临床检验杂志

Objective@#To study the effects of serum and its components on biofilm formation of Pseudomonas aeruginosa. @*Methods@#96 well microplates combined with crystal violet staining was used to detect the effects of serum, albumin and transferrin on biofilm formation of Pseudomonas aeruginosa. And confocal laser scanning microscope was used to observe the morphology of the biofilm. @*Results@#The biofilm of PAO1 was significantly enhanced from 2.26±0.42 to 3.42±0.08（t=4.71, p<0.01）with horse serum and but reduced to 0.807±0.10（t=4.71,p<0.01） by human serum; And the total biofilm biomass was significantly increased and clump-changed with horse serum, but decreased and scattered in distribution by human serum. Besides, horse serum could also enhance the biofilm formation of part of the clinical isolates of Pseudomonas aeruginosa, however, human serum could inhibit the biofilm formation of all of the clinical isolates. And 2.5g/L albumin could significantly enhance the biofilm of PAO1 from 1.96±0.22 to 2.54±0.18（t=3.55，p<0.05）, but 5 g/L could reduce the biofilm of PAO1 from 1.85±0.36 to 0.84±0.24（t=4.03，p<0.05）.@*Conclusion@#Horse serum and albumin could significantly promote the biofilm formation of Pseudomonas aeruginosa, but human serum and transferrin could decrease its biofilm formation.

Feasibility of confocal laser scanning microscopy with slit-lamp microscope in the diagnosis of filamentous fungal corneal infection with culture negative patients / 中华实验眼科杂志

Objective To investigate the imaging manifestations of different filamentous fungal strains under the confocal laser scanning microscope and slit-lamp microscope,and evaluate the feasibility of rapid diagnosis and therapeutic efficacy judgment for fungal culture negative patients.Methods A diagnosis trail was performed.Nine hundred and ninety-three patients with fungal keratitis (FK) which were varified by fungal culture were included in Henan Eye Hospital from September 2013 to January 2014.Distribution of fungi strains and positive rate of fungal strains by fungal culture and corneal confocal laser scanning microscopy were compared.The imaging characteristics of different filamentous fungi and different stages of one filamentous fungi under the slit-lamp microscope and confocal laser scanning microscopy were summarized.Results In the 993 FK patients,the diagnostic positive rate of fungal culture and confocal laser scanning microscopy was 43.20％ and 82.07％,respectively,showing a significant difference between them (x2 =45.323,P =0.000).In 429 culture-positive patients,the diagnostic positive rate of confocal laser scanning microscopy was 92.31％;while in 564 culture-negative patients,the diagnostic positive rate of confocal laser scanning microscopy was 74.29％.In 429 culture-positive patients,Aspergillus was the most common genus,accounting for 50.12％,and followed by Fusarium sp.and Altemaria sp.(18.18％ and 10.49％).There were no significant differences in fungal species distributions between fungal culture and confocal laser scanning microscopy examination in 429 cases (all at P＞0.05).The imaging characteristics under the slit-lamp microscope and confocal laser scanning microscope were different in different fungi stains.Aspergillus infection showed a plume-like corneal ulcer,and the Aspergillus sp.hyphae were thin and line-shaped with high reflective light and less branched under the confocal laser scanning microscope.Toothpaste-like corneal infiltration was seen in Fusarium sp.-infectious lesions under the slit lamp microscope,and mycelium showed a high-reflective long rod-like image with less branch in the image of confocal laser scanning microscope.Alternaria alternate sp.corneal infection showed nevus lesions,and hyphae characterized by high-reflective long rod or string beads in shape with less branches in the image of confocal laser scanning microscope.The mycelium was ruptured,shorter,thinner with weak reflective light following drug therapy.The differential diagnosis could be easily obtained between hyphae and corneal nerve fibers by confocal laser scanning microscope.Hyphae intertwined,or had branches with diffuse distribution,which surrounded by highreflective inflammatory cells and destructed matrix fiber and were located in stroma.The corneal nerve fibers located between epithelium layer and stroma layer,surrounded by normal epithelium or stroma structure.The diameter of the thicker nerve fibers in the stroma layer was obviously thicker than that of the hyphae.Conclusions The diagnosis rate of confocal laser scanning microscope combined with slit-lamp microscope for filamentous fungi-infectious FK is higher than that of fungal culture.The combination procedure of confocal laser scanning microscope and slit lamp microscope examination provides a rapid evaluation for fungi strains and therapeutic efficacy in the FK patients with negative results by fungal culture.

Effect of three different irrigation solutions applied by passive ultrasonic irrigation

OBJECTIVES: This study evaluated the maximum depth and percentage of irrigant penetration into dentinal tubules by passive ultrasonic irrigation (PUI). MATERIALS AND METHODS: Thirty extracted human teeth were instrumented and divided into three groups. According to final irrigation regimen, 5.25% sodium hypochlorite (Group A, NaOCl), 2% chlorhexidine (Group B, CHX) and saline solution (Group C, control group) were applied with Irrisafe 20 tips (Acteon) and PUI. Irrigant was mixed with 0.1% rhodamine B. Sections at 2 mm, 5 mm, and 8 mm from the apex were examined with confocal laser scanning microscopy (CLSM). The percentage and maximum depth of irrigant penetration were measured. Kruskal-Wallis test and Mann-Whitney test were performed for overall comparison between groups at each level and for pairwise comparison, respectively. Within a group, Wilcoxon test was performed among different levels. p values less than 0.05 were considered significant. RESULTS: In all groups, highest penetration depth and percentage of penetration were observed at the 8 mm level. At 2 mm level, Groups A and B had significantly greater depths and percentages in penetration than Group C (p < 0.05), but there were no significant differences between Groups A and B. At 5 mm level, penetration depths and percentage of penetration was not significantly different among the groups. CONCLUSIONS: NaOCl and CHX applied by PUI showed similar depth and percentage of penetration at all evaluated levels.

Effect of three different irrigation solutions applied by passive ultrasonic irrigation

OBJECTIVES: This study evaluated the maximum depth and percentage of irrigant penetration into dentinal tubules by passive ultrasonic irrigation (PUI). MATERIALS AND METHODS: Thirty extracted human teeth were instrumented and divided into three groups. According to final irrigation regimen, 5.25% sodium hypochlorite (Group A, NaOCl), 2% chlorhexidine (Group B, CHX) and saline solution (Group C, control group) were applied with Irrisafe 20 tips (Acteon) and PUI. Irrigant was mixed with 0.1% rhodamine B. Sections at 2 mm, 5 mm, and 8 mm from the apex were examined with confocal laser scanning microscopy (CLSM). The percentage and maximum depth of irrigant penetration were measured. Kruskal-Wallis test and Mann-Whitney test were performed for overall comparison between groups at each level and for pairwise comparison, respectively. Within a group, Wilcoxon test was performed among different levels. p values less than 0.05 were considered significant. RESULTS: In all groups, highest penetration depth and percentage of penetration were observed at the 8 mm level. At 2 mm level, Groups A and B had significantly greater depths and percentages in penetration than Group C (p < 0.05), but there were no significant differences between Groups A and B. At 5 mm level, penetration depths and percentage of penetration was not significantly different among the groups. CONCLUSIONS: NaOCl and CHX applied by PUI showed similar depth and percentage of penetration at all evaluated levels.

Influence of the accuracy of abutment tooth preparation on the marginal adaptation of Co-Cr alloy copings fabricated with a selective laser sintering technology / 대한치과보철학회지

PURPOSE: The purpose of present study is to examine the correlation between the accuracy of abutment preparation and the marginal adaptation of metal coping. With this view, this study compared the correlations regard to the three different manufacturing methods of selective laser sintering technique, milling and casting. MATERIALS AND METHODS: Two master models were made in a different way. First model with deep chamfer margin was prepared directly by a general clinician and the second model was designed by 3-D designing software program with the same abutment preparation principle and produced by computer aided manufacturing. 12 Co-Cr alloy copings were produced respectively with three different method; SLS system, CAD/CAM milling and conventional lost wax technique from each master model. The total 72 copings fully sit on the master model were stereoscopically evaluated at 40 points along the entire circumferential margin. RESULTS: Significant differences in the absolute marginal discrepancies of Co-Cr copings from SLS system (P=.0231) and casting method (P<.0001) were shown between hand preparation model and computer designed model. However, no significant difference was found between the two model groups from milling method (P=.9962). CONCLUSION: Within the limitation of this study, the effect of the accuracy of abutment preparation on the marginal adaptation of Co-Cr coping is statistically significant in SLS system and casting group. The copings produced by SLS system exhibited the lowest marginal discrepancies among all groups, and the marginal gap of this method group was influenced by the accuracy of the abutment preparation.

The relationship between Streptococcus pneumoniae biofilm formation and antibiotic resistance / 医学研究生学报

Objective Streptococcus pneumoniae can form biofilms .The aim of this study was to investigate the biofilm forma-tion of Streptococcus pneumoniae and the relationship with antibiotic resistance of penicillin etc . Methods A total of 147 clinical iso-lates of Streptococcus pneumoniae were collected from 7 teaching hospitals in Nanjing from 2010 to 2012.Minimal inhibitory concentration (MIC) of penicillin, erythromycin, cefuroxime and ceftriaxone were determined by agar dilution method .Streptococcus pneumoniae with various penicillin MIC was selected randomly as follow:MIC≤0.065μg/mL, 0.5μg/mL, 2μg/mL and≥4μg/mL, which was incuba-ted to form biofilms in 96-well plates and 24-well plates for 24 hours.The A values at 570 nm was measured and the biofilm was observed through confocal laser scanning microscope ( CLSM) . Results The biofilm semi-quantitative detection and CLSM both displayed that all strains formed biofilms.The A value of the group which penicillin MIC was ≤0.065μg/mL (0.228 ±0.063) was higher than the 0.5μg/mL group (0.200 ±0.061) and the≥4μg/mL group (0.186 ±0.050) (P0.05).The A value of the group which erythromycin MIC was ≤0.5μg/mL (0.211 ±0.068) was higher than the ≥4μg/mL group (0.201 ±0.052) (P>0.05).The A value of the group sensitive to cefuroxime (0.216 ±0.062) was higher than the group resistant to cefuroxime (0.196 ±0.054) (P<0.05). Conclusion Streptococcus pneumoniae can form biofilms .Streptococcus pneumoniae with high antibiotics MIC has a trend of weakened biofilm formation .

An experimental study of cutting efficiency of air-driven diamond burs on human tooth / 대한치과보철학회지

PURPOSE: The purpose of this study was to investigate the cutting efficiency of coarse grit diamond burs with air-turbine handpiece on natural tooth. MATERIALS AND METHODS: Four groups of coarse grit diamond bur were selected: Komet (A), Shofu (B), Premier (C), and Mani (D). The extracted maxillary central incisors were used, and ten cuts were made on each specimen, using the rotary diamond burs. The surface of each bur was measured at the upper, middle, and bottom of the bur with confocal laser scanning microscope and imaged with SEM. The data were analyzed with one-way ANOVA and t-test at the significance level of 0.05. RESULTS: The surface roughness was measured. At the A diamond bur, the Sa values were 52.93 microm, 48.32 microm, 46.79 microm, 45.06 microm, and 43.43 microm for control, test 1, 2, 3, and 4 respectively. The Sa values were 50.68 microm, 45.62 microm, 44.41 microm, 44.10 microm, and 42.46 microm for B diamond bur, 58.02 microm, 55.53 microm, 52.22 microm, 48.26 microm, and 45.36 microm for C diamond bur, and 50.11 microm, 46.73 microm, 45.46 microm, 42.58 microm, and 41.80 microm for D diamond bur. Surface roughness after each bur use showed significant changes, but no significant difference was found in surface roughness change between bur systems. CONCLUSIONS: Surface roughness in the same bur system showed significant differences after each tooth preparation. However no statistically significant differences were found in surface roughness between bur systems. The SEM images between control and test 4 showed the abraded particles.

The effect of gold electroforming procedure on gold-silver-palladium alloy / 대한치과보철학회지

STATEMENT OF PROBLEM: The effect of gold electroforming on gold alloy was not studied. PURPOSE: This in vitro study investigate the effect of gold electroforming on gold-silver-palladium alloy. MATERIAL AND METHODS: Three pieces of gold strips had undergone the electroforming procedures on one side and then half of the side again electroformed. The set mode for this study was program 1 (200 micrometer). And the processing time was 15min (1/20 time to form 200 micrometer coping). The confocal laser scanning microscope (PASCAL 5, Carl Zeiss, Bernried, Germany) was used to measure the thickness of the pure gold layer electroformed on the gold strips. Half of the gold strip was coated two times with electroformed gold, and the other half one time. The data from the cone focal laser system was processed to get the vertical profile of the strips and the difference of the vertical height between the double coated and single coated layer was regarded as the thickness of the gold coating. The layer thickness value to built 3D image of the cone-focal laser was set 0.5 micrometer. Next to the measurement of the thickness of the coating, the Vicker's hardness test was done. It was performed on the double coated surface, single coated surface and non-coated surface (back side) three times each. RESULTS: The mean thickness value gained from gold electroforming technique was measured to be 22 micrometer for sample 1, 23 micrometer for sample 2, 21 micrometer for sample 3. In the same condition of time, power and the amount of electrolyte, the data showed no difference between samples. According to the results of variance analysis, the differences among the variations in number of coating were statistically insignificant (p>0.05), meaning that the two times of gold electroforming coating did not change the hardness of gold-silver-palladium alloy. CONCLUSION: The test of thickness of gold coating proved the coherency of the gold electroforming procedure, in other words, when the power, the exposed surface area, processing time and the amount of electrolytes were set same, the same thickness of gold would be coated on. The hardness test showed that the electroformed gold coating did not change the hardness of the gold-silver-palladium alloy when it is coated not more than 45 micrometer.

Preliminary study on the effect of inflamed TMJ synovial fluid on the intracellular calcium concentration and differential expression of iNOS and COX-2 in human immortalized chondrocyte C28/I2

OBJECTIVE: The objective of this study was to examine the hypothesis that inflammatory synovial fluid from TMJ internal derangement initiates a transient increase in intracellular calcium concentration ([Ca2+]i) in chondrocytes and the induced Ca2+ signaling affects iNOS/COX-2 gene expression patterns following exposure to inflamed synovial fluid. MATERIALS AND METHODS: Two female adult patients with symptoms of TMD who agreed to participate in the study were selected for this study. Immortalized human juvenile costal chondrocyte C-28/I2 was grown to 80% confluency and synovial fluids from two patients were added respectively to culture media for 24 hours at the concentration of 100ng/10ml. Confocal laser scanning microscope (CLSM) was used to examine changes of intracellular calcium concentration ([Ca2+]i). RT-PCR was performed to identify the expression profile of IL-1alpha, iNOS, COX-2. RESULTS: Increased [Ca2+]i was observed in chondrocytes subjected to inflamed synovial fluid compared to control cultures and in respective cultures exposed to inflamed synovial fluids from each patient, IL-1beta, COX-2 mRNA were detected. However, in neither case iNOS mRNA was expressed. IL-1alpha, COX-2, and iNOS mRNA were expressed in control culture. CONCLUSION: Our results show that immortalized chondrocytes cultured with inflamed synovial fluids from patients diagnosed as disc displacement without reduction and limitation in mouth opening showed increased calcium concentration and expression of COX-2 while inhibiting the production of iNOS, which in turn could adversely affect the chondrocytes in at least short term by hindering physiologic role of NO against inflammatory cascades. These findings suggest that inflamed synovial fluid may differentially regulate the transcriptomes of relevant inflammatory mediators, especially iNOS/COX-2 axis in chondrocytes through adjusting calcium transients.

Changes of Apoptosis After X-irradiation During the Hindlimb Development in the Rat Fetus / 체질인류학회지

Ionizing radiation exerts harmful effect during the limb development, but the exact mechanism is still largely unknown. In this study, 2 Gy of X-ray irradiated to the rat fetuses on gestation day of 13.7 when the hindlimb buds appear, and sacrificed at GD 14.7, GD 15.7 and GD 16.7, respectively. To reveal the changes of apoptotic figures between control and experimental groups, TUNEL immunohistochemistry and confocal laser scanning microscopy were carried. Mean body weight of fetuses of irradiated groups were decreased significantly compared to the control group. Numerical digit anomalies and asymmetries between right and left sides were increased significantly in the irradiated group compared to control group. Some digit anomalies were increased significantly in the right side. Radiation-induced decrement of the density of apoptotic figures on GD 14.7 was presumed to be related with foot and digit anomalies.

The effect of multiple application on microtensile bond strength of all-in-one dentin adhesive systems / 대한치과보존학회지

The purpose of this study was to evaluate the effect of multiple application of all-in-one dentin adhesive system on microtensile bond strength using confocal laser scanning microscope and microtensile bond strength test. Flat occlusal dentin surfaces were prepared using low-speed diamond saw. In group I, Scotchbond Multipurpose (SM) was applied by manufacturer's recommendation. In group II, after Adper Prompt L-Pop was applied for 15s and light cured for 10s, the second coat was re-applied and light-cured. In group III, after light-curing the second layer, the third coat was re-applied and light-cured. Specimens bonded with a resin-composite were sectioned into resin-dentin stick for measuring the adhesive layer thickness by confocal laser scanning microscope and evaluating micro-tensile bond strength. The adhesive layers of three-step dentin adhesive system, 3 coats of Adper Prompt L-Pop had significantly thicker than SM, 2 coats of Adper Prompt L-Pop (p 0.05). And SM, 3 coats of Adper Prompt L-Pop had significantly higher than 2 coats of Adper Prompt L-Pop in bond strengths (p < 0.05).

The effect of hybrid layer thickness on microtensile bond strength of three-step and self-etching dentin adhesive systems / 대한치과보존학회지

The purpose of this study was to evaluate the correlation between hybrid layer thickness and bond strength using confocal laser scanning microscope and microtensile bond strength test of two adhesive systems. The dentin surface of human molars, sectioned to remove the enamel from the occlusal surface. Either Scotchbond Multi-Purpose(3M Dental Product, St. Paul, MN, U.S.A) or Clearfil SE Bond(Kuraray, Osaka, Japan) was bonded to the surface, and covered with resin-composite. The resin-bonded teeth were serially sliced perpendicular to the adhesive interface to measure the hybrid layer thickness by confocal laser scanning microscope. The specimen were trimmed to give a bonded cross-sectional surface area of 1mm2, then the micro-tensile bone test was performed at a crosshead speed of 1.0 mm/min. All fractured surfaces were also observed by stereomicroscope. There was no significant differences in bond strengths the materials(p>0.05). However, the hybrid layers of three-step dentin adhesive system, SM, had significantly thicker than self-etching adhesive system, CS(p0.05). Bond strengths of dentin adhesive systems were not dependent on the thickness of hybrid layer.

Relationship of chronic central pain and substance P in spinal dorsal horn after spinal cord injury / 中国康复理论与实践

@#Objective To approach the neurobiochemical mechanism of chronic central pain (CCP) after spinal cord injury (SCI). Methods 28 SD rats were divided into four groups, the normal group (group A), the pseudosurgery group (group B), and groups with CCP (group C) and without CCP (group D) after L1 spinal cord section injured with WADE method. T13 and L2 segments of rats' spinal cord were took and concentration changes of substance P (SP) in the spinal dorsal horn between two sections were examined by immunofluorescence histochemistry staining combined with confocal laser scanning microscope. Results Concentration of SP in the group D was decreased significantly compared with groups C,A and B (P<0.05-0.01), that of the group C was less than that of group A and B (P<0.05). Conclusion The rat model established by WADE method is proper to study CCP after SCI. SP in dorsal horn of spinal cord may inhibit the CCP after SCI in some degrees.

Effect of Puerarin on calcium overload in cultured human umbilical vascular endothelial cells / 中国药理学通报

Aim To examine the effect of Puerarin on calcium overload in human umbilical vascular endothelial cells(HUVECs).Methods The HUVECs were incubated with Puerarin,then were exposed to H_2O_2,ATP and high K~+.The changes of intracellular free calcium([Ca~(2+)]i) in HUVECs were determined using fluorescent Ca~(2+)-indicator fluo-3/AM with confocal laser scanning microscope.Results Puerarin inhibited the elevation of [Ca~(2+)]i induced by H_2O_2,ATP and high K~+,and the inhibition ratio were 72.2%,56.5% and 78.2% respectively.The effect of Puerarin inhibiting the elevation of [Ca~(2+)]i induced by high K~+ was similar to that of verapamil.Conclusion The mechanism of puerarin reducing the overload of calcium in HUVECs may be related with blocking both voltage-dependent calcium channels and the release of calcium pool in endoplasm.

Animal Experiment of Several Kinds of Podophyllotoxin Liposome for Topical Application on Skin / 中国药房

OBJECTIVE: To observe the release mode and the amount of retention in skin of podophyllotoxin liposomes in topical application. METHODS: Two kinds of podophyllotoxin liposome suspension (DPPC liposome and bean lecithin liposome) and podophyllotoxin tincture in same concentration were topically applied on the skin of porkets and the amounts of retention of drug in skin of different preparations were detected with confocal laser scanning microscope.RESULTS: The quantity of retention of podophyllotoxin DPPC liposome in epidermis and superficial layer of dermis was larger than those of other two preparations and the drug concentration in applying DPPC liposome kept higher for 48 hours.CONCLUSION:Podophyllotoxin liposome coated by DPPC is much more targetable to skin and is a fairly good topical preparation for applying on skin.

Effect of Liposome Suspension on Distribution of Fluorescein Sodium in Rat Skin / 中国药房

OBJECTIVE:To study effect of liposome suspension on distribution of fluorescein sodium in the rat skin.METHODS:Using0.125%fluorescein sodium(NaFl)solution as control,the distribution of NaFl in epidermis and dermis at different time periods was observed under confocal laser scanning microscope in0.125%NaFl liposome suspension group(trial group).RESULTS:The fluorescent intensity peaks in epidermis and dermis of trial group were higher than those in skin layers of control group(P