In vitro evaluation of the impact of a bioceramic root canal sealer on the mechanical properties of tooth roots.

Bacground/purpose: Endodontically treated teeth are more prone to vertical root fracture with the mechanical property changes to some extent during root canal treatment. This study aimed to investigate the effects of a bioceramic sealer on the mechanical properties of tooth roots. Materials and methods: Dentin discs were dried by two different methods (ethanol drying and paper points drying) and then filled with a BC sealer named iRoot SP. SEM and EDS were used to analyze the newly formed minerals in dentin tubules. Elastic modulus and hardness of the secondary dentin in areas proximal to the primary dentin (PD-SD) and areas proximal to canal or iRoot SP (SD-C/SD-iRoot SP) were measured using nanoindentation technique. The compressive strength of roots filled with iRoot SP were tested by compressive loading test. Results: (1) Penetration and mineralization: Paper points drying was more conducive to iRoot SP adhesion, spreading and penetration into the dentin tubules than 95% ethanol drying. (2) Micromechanical properties: After filling root canal with iRoot SP, the elastic modulus and hardness of SD-iRoot SP were higher than those of PD-SD (P = 0.001 and P = 0.000). (3) Fracture resistance: The compressive strength of the roots filled with iRoot SP was not significantly different from that of the roots unprepared and unfilled (P = 0.957), but was higher than that of the roots prepared and unfilled (P = 0.009). Conclusion: Excessive drying (95% ethanol drying method) is not conducive to the penetration and mineralization of the BC sealer iRoot SP into dentin tubules. The good bioactivity of iRoot SP was responsible for increasing the elastic modulus and hardness of dentin, which strengthened the prepared roots.

[Growth ability of human dental pulp cells on three bioactive scaffolds].

OBJECTIVE: To investigate the proliferation and differentiation of the human dental pulp cells (hDPCs) on the bioactive scaffolds. METHODS: Primary HDPCs were harvested from impacted third molars of healthy adult individuals (18-25 years of age) by enzyme digestion, expanded and cultured. The cells used for this investigation were the 4 th passage. Immunohistochemical methods were used to verify that the cells were dental pulp cells. The expression of stromal precursor antigen-1 (STRO-1) was determined by flow cytometry. Three different types of scaffolds were used: collagen (COL), collagen / bioglass (COL-BG) and collagen / bioglass / polycaprolactone (COL-BG-PCL). Cell proliferation on the scaffolds was determined using a MTT assay at hour 6, on days 1, 3, 5, 7, 14 and 21. On day 14, the scaffolds were stained with the alkaline phosphatase (ALP) staining kit. RESULTS: The tested cells had STRO-1 positive cells. The proliferation of HDPCs was significantly higher on the COL-BG scaffold and COL-BG-PCL scaffold as compared with COL scaffold (P<0.05). Especially on days 14 and 21, the optical density value of bioglass composite scaffold were 5 times that of the COL scaffold. The ALP positive staining area was observed more extensively on the COL-BG scaffold and COL-BG-PCL scaffold than on the COL scaffold. CONCLUSION: As comparison with the COL scaffold, HDPCs' proliferation and differentiation present more activity on the COL-BG and COL-BG-PCL scaffolds.

Effect of a bioactive glass-based root canal sealer on root fracture resistance ability.

Background/purpose: The root fracture resistance of endodontically treated teeth is decreased significantly, and it is more likely to fracture. This study aimed to evaluate the effect of a novel root canal sealer based on bioactive glass (BG) on root fracture resistance and explore its mechanism. Materials and methods: The BG-based root canal sealer (BG Sealer) was prepared by mixing a kind of bioactive glass (10.8% P2O5, 54.2% SiO2, 35% CaO, mol.%, named PSC), zirconia (ZrO2) powder, sodium alginate (SA) and phosphate solution (PS). A pH meter was used to measure the pH of simulated body fluid (SBF) after immersion with BG Sealer at different time. After preparing the samples of BG sealer with a diameter of 4 mm and a height of 6 mm, the compressive strength was tested by a universal testing machine. The scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used to detect and analyze the mineral status of root canal systems filled with BG Sealer. The push out test was used to measure the push out bond strength of BG Sealer. The fracture resistance of root canals filled with BG Sealer was detected by the compressive loading test. Bioceramic root canal sealer iRoot SP was set as the control group. Results: (1) Physicochemical properties: The pH value of SBF immersed with BG Sealer increased slightly up to 7.68, while the pH of SBF immersed with iRoot SP increased to 12.08. The compressive strength of the novel BG Sealer was 4.62 ± 1.70 MPa, which was lower than that of iRoot SP (P < 0.05). (2) Mineralization: The hydroxyapatite layers were observed on the surface of BG Sealer and iRoot SP after being immersed in SBF for 4 weeks. BG Sealer and iRoot SP were both able to penetrate into the dentin tubules, duplicate the morphology of root canals well, and form a layer of hydroxyapatite. (3) Adhesion to dentin: There was no significant difference between the push out bond strength of the novel BG Sealer and iRoot SP (P > 0.05). (4) Fracture resistance: After immersion in SBF for 4 weeks, the fracture resistance of roots filled with BG Sealer and iRoot SP was 454.16 ± 155.39 N and 445.50 ± 164.73 N, respectively, both of which were not statistically different from that of the roots unprepared and unfilled (394.07 ± 62.12 N) (P > 0.05), whereas higher than that of the roots prepared and unfilled (235.36 ± 83.80 N) (P < 0.05). Conclusion: The novel BG Sealer has good adhesion to the root dentin, can penetrate into the dentin tubules to generate minerals, and meanwhile can improve the fracture resistance of the roots after root canal treatment. It is expected to be a bioactive root canal sealer with good clinical application prospects.

Glyphosate based-herbicide disrupts energy metabolism and activates inflammatory response through oxidative stress in mice liver.

Glyphosate, the most widely used herbicide worldwide, has been reported to cause hepatotoxicity. However, these systematic mechanisms remain poorly understood. Here, we investigated the effects of glyphosate-based herbicides (GBH) on liver toxicity in mice exposed to 0, 50, 250, and 500 mg/kg/day GBH for 30 d. Pathological and ultrastructural changes, serum biochemical indicators, oxidative stress state, and transcriptome and key protein alterations were performed to describe the hepatic responses to GBH. GBH induced hepatocytes structural alterations, vacuolation, and inflammatory, mitochondrial swelling and vacuolization; damaged liver function and aggravated oxidative stress; blocked the respiratory chain, promoted gluconeogenesis, fatty acid synthesis and elongation, and activated complement and coagulation cascades system (CCCS) in the liver. Moreover, SOD, H2O2, and MDA were negatively correlated with the CxI and CxIV genes, but positively correlated with the genes in glucolipid metabolism and CCCS pathways; however, the opposite results were observed for CAT, GSH-Px, and T-AOC. Overall, this study revealed the systematic mechanism underlying hepatotoxicity caused by GBH, providing new insights into understanding the hepatotoxicity of organophosphorus pesticide.

[Effects of ionic-dissolution of sol-gel bioactive glasses on human dental pulp cells].

OBJECTIVE: To evaluate the effects of ionic-dissolution of sol-gel bioactive glasses (BG) on proliferation and alkaline phosphatase (ALP) activity of human dental pulp cells (HDPCs) . METHODS: The primary HDPCs were isolated from intact premolar and third molars and were cultured in DMEM. Then the 4 th generation of HDPCs were cultured in DMEM, which contained 1 g/L of one of 58S, Nano-58S, and 45S5 ionic-dissolution products. Meanwhile HDPCs were cultured in DMEM without BG as control group. Proliferation of the cells was evaluated by MTT assay on days 1,3,5 and 7. ALP activity was measured on day 14 using ALP Assay Kit. RESULTS: Compared with the control group, HDPCs' proliferation in the Nano-58S group increased significantly. HDPCs cultured in Nano-58S and the 58S groups showed higher ALP activity (P<0.01); but in 45S5 group showed an inhibition on the HDPCs' proliferation (P<0.01) and lower ALP activity (P<0.05). CONCLUSION: Present work has shown that Nano-58S and 58S sol-gel BG can promote the proliferation and ALP activity of HDPCs.

A novel bioactive glass-based root canal sealer in endodontics.

BACKGROUND/PURPOSE: Bioactive glass (BG), one type of bioceramics, shows similar or better characteristics to calcium silicate which has been regarded as a promising root filling material in endodontics. This study aimed to develop a novel BG-based root canal sealer for endodontics. MATERIALS AND METHODS: The novel BG-based root canal sealer was composed of phytic acid derived bioactive calcium phosphosilicate glass named PSC mixed with zirconium oxide (ZrO2) as powder, and phosphate solution (PS) dissolved with sodium alginate (SA) named PS-SA as liquid. Moreover, the physicochemical properties, mineralization, sealing ability and biocompatibility of the novel BG-based root canal sealer were evaluated. RESULTS: This study developed a novel BG-based sealer named BGS-SA-Zr which contained the powder of PSC and ZrO2 and the liquid of PS-SA. Results indicated that the flow, film thickness and radiopacity of BGS-SA-Zr conformed to ISO 6876:2012. The setting time and solubility of BGS-SA-Zr were 53.7 ±â€¯1.5 min and 21.46 ±â€¯0.54%, respectively. The pH value of the simulated body fluid (SBF) immersed with BGS-SA-Zr raised slightly up to 7.70. The CCK-8 assay indicated that BGS-SA-Zr had no cytotoxic effects on MG-63 cells. After immersion in SBF for 4 weeks, dense hydroxyapatite crystals were observed on the surface of BGS-SA-Zr. Furthermore, there was no difference in the sealing ability between BGS-SA-Zr and the bioceramic sealer iRoot SP whether setting at 1 day or immersed in SBF for 4 weeks (P > 0.05). CONCLUSION: Our results suggest that the novel BG-based sealer may be a promising sealer for endodontic treatment.

[Effects of light-curing modes on the polymerization shrinkage and surface hardness of composite resins].

OBJECTIVE: To investigate the effects of light-curing modes on the polymerization shrinkage and surface hardness of resins and to explore the related clinical relevance. METHODS: Resins with filler content of 76%(mass fraction) were light-cured by high intensity, low intensity and soft start curing modes for 10 s and 20 s, respectively. Specimens for detecting volumetric shrinkage and surface hardness were prepared. Volumetric shrinkage was measured with Acuvol (n=7) and surface hardness were tested with an indenter (n=5). RESULTS: The volumetric shrinkage of composites cured by high intensity, low intensity and soft-start curing mode was: 2.95% ± 0.08%/3.06% ± 0.03% (10 s/20 s), 2.98% ± 0.12%/3.05% ± 0.13% (10 s/20 s), and 3.03% ± 0.05%/3.11% ± 0.07% (10 s/20 s), respectively. No significant difference existed among polymerization shrinkage of composites cured by the three light-curing modes (P>0.05). The hardness of composites cured by high intensity, low intensity and soft-start curing mode was: (36.82 ± 4.45) MPa/(47.58 ± 3.16) MPa (10 s/20 s), (32.30 ± 1.33) MPa/(41.60 ± 1.83) MPa (10 s/20 s), and (34.56 ± 1.38) MPa/(44.62 ± 2.13) MPa (10 s/20 s), respectively. There existed significant difference among hardness of composites cured by the three light-curing modes (P<0.05). Polymerization shrinkage was correlated with energy density (r=-0.363,P=0.018). Surface hardness was also correlated with energy density (r=-0.890,P<0.001). CONCLUSION: It would be better to use high intensity curing mode to improve the physical properties of restorations. In order to keep the physical properties of composites, it is necessary to prolong the curing time using soft-start/low intensity curing modes to increase the energy density.

The effect of topical application of meloxicam on inflamed dental pulp.

BACKGROUND/PURPOSE: Effective regulation of the inflammatory process is essential for pulp repair and regeneration. Meloxicam has anti-inflammatory activity in systemic administration. The purpose of this study is to observe effects of topically applied meloxicam on inflamed pulp and to explore its potential value in the treatment of pulpitis. MATERIALS AND METHODS: The coronal pulp tissues of rat molars were stimulated with 10 mg/mL lipopolysaccharide (LPS group) and then treated with 500 µmol/L meloxicam (meloxicam group). The untreated pulp tissues were used as the control group. After 3 h of incubation in vitro, the gene expression of interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) in each group was detected by real-time RT-PCR. The pulp tissues of each group were randomly subcutaneously implanted into nude mice, and 500 µmol/L meloxicam was injected into the subcutaneous pocket of the meloxicam group. Haematoxylin eosin staining, Masson staining and immunohistochemical staining were performed on samples after 3 days and 4 weeks retrieval, respectively. RESULTS: Compared with the LPS group, the mRNA expression levels of TNF-α and IL-6 of the meloxicam group were significantly reduced in vitro. The inflammatory response and cyclooxygenase-2 expression of the meloxicam group were decreased, and osteodentin-like tissue was generated in the pulp cross section of the meloxicam group in vivo. CONCLUSION: The topical application of meloxicam inhibits the inflammatory response of inflamed pulp and further promotes the formation of osteodentin-like tissues but fails to induce the formation of the pulp-dentin complex. Topically applied meloxicam has the potential to regulate pulp inflammation.

[Effect of filler content of composite resins on polymerization shrinkage measured by a video imaging apparatus (Acuvol)].

OBJECTIVE: To investigate the effect of filler content on the polymerization shrinkage of resins and to evaluate whether Acuvol is a simple and easy method in volumetric shrinkage measurement. METHODS: Six experimental resins with filler contents of 80%, 78%, 76%, 70%, 60%, and 50% were made. Three commercial resins were Syn D6 with 80% filler content, Syn Compact Nano with 74% filler content and Syn Flow with 55% filler content(using the mass fraction to express the filler content). Small semi-sphere samples of these composites were manually formed and light cured for 40 s using a quartz tungsten halogen unit at 650 mW/cm2 (n=10). The volumetric shrinkage was measured in both SVVR and MVVR modes using Acuvol. RESULTS: The volumetric shrinkage of the three commercial resins were: Syn Flow > Syn Compact Nano > Syn D6. The shrinkage values of the six experimental resins with different filler contents were: 50% > 60% > 70% > 76% > 78% > 80%. The negative correlation between filler content and volumetric shrinkage of commercial and experimental resins were strongly (-0.982 and -0.968 respectively, P<0.001). No significant difference between SVVR and MVVR modes (t=0.385, P>0.05). CONCLUSION: The present results support the view that filler content is one of the most important factors influencing polymerization shrinkage of composites. Acuvol provides an easy method for measuring polymerization shrinkage of composites. Both SVVR and MVVR modes of Acuvol give reproducible results.

Multiple genome pattern analysis and signature gene identification for the Caucasian lung adenocarcinoma patients with different tobacco exposure patterns.

BACKGROUND: When considering therapies for lung adenocarcinoma (LUAD) patients, the carcinogenic mechanisms of smokers are believed to differ from those who have never smoked. The rising trend in the proportion of nonsmokers in LUAD urgently requires the understanding of such differences at a molecular level for the development of precision medicine. METHODS: Three independent LUAD tumor sample sets-TCGA, SPORE and EDRN-were used. Genome patterns of expression (GE), copy number variation (CNV) and methylation (ME) were reviewed to discover the differences between them for both smokers and nonsmokers. Tobacco-related signature genes distinguishing these two groups of LUAD were identified using the GE, ME and CNV values of the whole genome. To do this, a novel iterative multi-step selection method based on the partial least squares (PLS) algorithm was proposed to overcome the high variable dimension and high noise inherent in the data. This method can thoroughly evaluate the importance of genes according to their statistical differences, biological functions and contributions to the tobacco exposure classification model. The kernel partial least squares (KPLS) method was used to further optimize the accuracies of the classification models. RESULTS: Forty-three, forty-eight and seventy-five genes were identified as GE, ME and CNV signatures, respectively, to distinguish smokers from nonsmokers. Using only the gene expression values of these 43 GE signature genes, ME values of the 48 ME signature genes or copy numbers of the 75 CNV signature genes, the accuracies of TCGA training and SPORE/EDRN independent validation datasets all exceed 76%. More importantly, the focal amplicon in Telomerase Reverse Transcriptase in nonsmokers, the broad deletion in ChrY in male nonsmokers and the greater amplification of MDM2 in female nonsmokers may explain why nonsmokers of both genders tend to suffer LUAD. These pattern analysis results may have clear biological interpretation in the molecular mechanism of tumorigenesis. Meanwhile, the identified signature genes may serve as potential drug targets for the precision medicine of LUAD.

Epigenome-Wide Tobacco-Related Methylation Signature Identification and Their Multilevel Regulatory Network Inference for Lung Adenocarcinoma.

Tobacco exposure is one of the major risks for the initiation and progress of lung cancer. The exact corresponding mechanisms, however, are mainly unknown. Recently, a growing body of evidence has been collected supporting the involvement of DNA methylation in the regulation of gene expression in cancer cells. The identification of tobacco-related signature methylation probes and the analysis of their regulatory networks at different molecular levels may be of a great help for understanding tobacco-related tumorigenesis. Three independent lung adenocarcinoma (LUAD) datasets were used to train and validate the tobacco exposure pattern classification model. A deep selecting method was proposed and used to identify methylation signature probes from hundreds of thousands of the whole epigenome probes. Then, BIMC (biweight midcorrelation coefficient) algorithm, SRC (Spearman's rank correlation) analysis, and shortest path tracing method were explored to identify associated genes at gene regulation level and protein-protein interaction level, respectively. Afterwards, the KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis and GO (Gene Ontology) enrichment analysis were used to analyze their molecular functions and associated pathways. 105 probes were identified as tobacco-related DNA methylation signatures. They belong to 95 genes which are involved in hsa04512, hsa04151, and other important pathways. At gene regulation level, 33 genes are uncovered to be highly related to signature probes by both BIMC and SRC methods. Among them, FARSB and other eight genes were uncovered as Hub genes in the gene regulatory network. Meanwhile, the PPI network about these 33 genes showed that MAGOH, FYN, and other five genes were the most connected core genes among them. These analysis results may provide clues for a clear biological interpretation in the molecular mechanism of tumorigenesis. Moreover, the identified signature probes may serve as potential drug targets for the precision medicine of LUAD.

[Effects of maternal high protein diet on uncoupling protein and carnitine palmityl transferase 1 in offspring of rats].

OBJECTIVE: To investigate the effects of maternal nutritional manipulation on fetal mRNA abundance of uncoupling protein UCP2, UCP3 and carnitine palmityl transferase 1 (CPT1), and find out an optimal maternal diet and targets for pharmacological prevention and treatment of obesity. METHODS: Wistar pregnant rats were assigned to two groups which received a standard diet (SD) and a high protein diet (HPD) during pregnancy, respectively. After delivery, the male offspring were assigned to control group (CON) and high protein group (HP) according to their maternal diet, which were suckled by dams that received SD during pregnancy. Offspring were fed with SD from weaning (week 3) to week 8. Then CON were allocated to two groups: CON (SD during the whole experiment); HFCON (high fat control). HFCON and HP group rats were fed with high-fat diet (HFD) for 6 wk to induce obesity. At 0, 3, 8 and 14 wk of age, blood and tissue were collected for analyzing blood fat and abundance of UCP2, 3 and CPT1 mRNA. RESULTS: In HP body weight and TG were decreased after weaning (F = 4.589, P = 0.039; F = 27.001, P = 0.000) and HFD (F = 16.076, P = 0.00; F = 71.518, P = 0.000). Obesity rates were significantly decreased in HP after HFD (chi2 = 8.076, P = 0.004). The abundance of UCP3 and CPT1 mRNA was persistently higher in HP than in CON or HFCON, and the abundance of UCP2 mRNA was also persistently higher than in CON or HFCON after weaning. Moreover the abundance of CPT1 mRNA was significantly increased after weaning and HFD compared with that after SD, the abundance of UCP2, UCP3 mRNA was also increased after HFD compared with that after SD. CONCLUSIONS: Increasing protein intake during pregnancy might prevent offspring from HFD-induced obesity in adult, moreover might increase offspring the expression of UCP2, UCP3 and CPT1 mRNA. UCP2, UCP3 and CPT1 might participate in prevention and treatment of obesity by mediating fatty acid oxidation.

Protection of a novel epitope-RNA VLP double-effective VLP vaccine for foot-and-mouth disease.

Foot and mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals. Previously, we found that the epitope peptide EP141-160 displayed on virus-like particles (VLP) for use as a vaccine showed high immunoreactivity and conferred partially effective protection to animals. In this study, we first combined antisense RNA with VLP as a vaccine against the foot-and-mouth disease virus (FMDV) by using a prokaryotic co-expression system. The antisense RNA against the 3D genes of FMDV was packaged into VLP with EP141-160 presented on the surface. ELISA and Western blotting proved that the epitope-RNA VLP eliciting an immune response to FMDV in mice. Furthermore, the potency of the vaccine was tested in mice and guinea pigs. The results indicated that the epitope-RNA VLP vaccine protected 40% of suckling mice and 85% (17/20) of guinea pigs from FMDV. Based on the experimental data, the epitope-RNA VLP vaccine should have value in exploring and developing vaccines against FMDV in the future.

Promising MS2 mediated virus-like particle vaccine against foot-and-mouth disease.

Foot-and-mouth disease (FMD) has caused severe economic losses to millions of farmers worldwide. In this work, the coding genes of 141-160 epitope peptide (EP141-160) of VP1 were inserted into the coat protein (CP) genes of MS2 in prokaryotic expression vector, and the recombinant protein self-assembled into virus-like particles (VLP). Results showed that the CP-EP141-160 VLP had a strong immunoreaction with the FMD virus (FMDV) antigen in vitro, and also had an effective immune response in mice. Further virus challenge tests were carried out on guinea pigs and swine, high-titer neutralizing antibodies were produced and the CP-EP141-160 VLP vaccine could protect most of the animals against FMDV.

Plaque minerals in the prediction of caries activity.

BACKGROUND/AIMS: Attempts to identify subjects who will develop caries lesions in future years have been only moderately successful, suggesting that one or more important risk factors are being overlooked. The aim of this study was to validate the use of plaque calcium, phosphate and fluoride concentrations as significant risk factors in caries. METHODS: DMFS and DMFT rates were measured three times over 2 years in a group of rural Chinese schoolchildren initially aged 12 years and not living in a high-fluoride area. At the baseline and year 1 examinations, dental plaque was accumulated for 3 days and, after collection, was analysed for Ca, P and F. Plaque scores, dental health behaviour and parents' occupation data were also recorded. RESULTS: The mean DMFS increment over 2 years was 1.14 with a range of -2 to +9. Regression analysis taking all factors into account identified only plaque Ca concentration, baseline DMFS score and toothbrushing frequency as significant factors in identifying high-risk individuals. Plaque Ca also showed predictive ability on its own. For example, when high caries was defined as 3+ new DMFS and a Ca cut-off value of 200 nmol/mg dry wt was selected, sensitivity was 0.84 and specificity 0.38. However, with this cut-off value the percentage predicted to have high caries risk was unrealistically high at 66%. As in several other studies, baseline caries score was a useful predictor of future caries. CONCLUSION: Low plaque Ca concentration showed a modest ability to predict future caries, and since it is implicated directly in the chain of events leading to caries, its use in caries prediction should be considered further. Plaque P and F showed no predictive ability in this study.

[Effect of bioactive glasses on angiogenic growth factors of human dental pulp cells].

OBJECTIVE: To investigate the effects of bioactive glasses (BG) including 45S5 and nano-58S on proliferation, angiogenic markers vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) secretion and gene expression of human dental pulp cells (HDPC). METHODS: HDPC of 4th passage were cultured in Dulbecco's modified Eagle's medium (DMEM) which contained 0.1 g/L 45S5 or nano-58S ionic dissolution products. Meanwhile HDPC were cultured in DMEM without BG as control group. Proliferation of the cells was evaluated with methyl thiazolyl tetrazolium (MTT) assay on day 1, 2, 3. Quantitative real-time PCR and quantitative sandwich enzyme immunoassays were used to test VEGF and bFGF gene expression and protein secretion of HDPC on day 1, 2, 3. RESULTS: The relative growth rate (RGR) of 45S5 and nano-58S groups were (134.5 ± 5.0)% and (146.3 ± 19.8)%, which was significantly different from that of control group (P < 0.05). The quantity of VEGF secretion of two experimental groups were (189.29 ± 4.64) and (216.18 ± 14.67) ng/L, respectively, significantly higher than that of the control group [(159.03 ± 11.69) ng/L] (P < 0.05). Furthermore, the nano-58S group secreted much more VEGF than 45S5 group (P < 0.05).bFGF secretion of HDPC was also enhanced by both 45S5 and nano-58S bioactive glasses. The VEGF gene expression of 45S5 and nano-58S on day 1 were (1.70 ± 0.19) and (1.63 ± 0.42), while the bFGF gene expressin on day 3 were (1.49 ± 0.02) and (2.30 ± 0.04), all significantly higher than that of control group (P < 0.05). CONCLUSIONS: Bioactive glasses can enhance the proliferation, VEGF and bFGF secretion and gene expression of human dental pulp cells. Compared with 45S5, nano-58S showed a higher activation.

Nano-sized 58S bioactive glass enhances proliferation and osteogenic genes expression of osteoblast-like cells.

OBJECTIVE: To observe the effects of ionic dissolution products on nano-sized 58S bioactive glass (nano-58S) on proliferation and specific osteogenic genes expression in MG-63 cells. METHODS: Ionic dissolution products were prepared by incubating nano-58S or sol-gel bioactive glass 58S (58S) particulates in Dulbecco's modified Eagle's medium (DMEM) at 1% w/v for 24 hr and filtrated through 0.22 µm filters to remove the particulates. MG-63 cells were cultured in the nano-58S extraction, 58S extraction, and DMEM, respectively, for different time periods to assay the proliferation, mRNA expression of alkaline phosphatase (ALP), Cbfa1, Collagen type I (Col-I) and osteocalcin (OCN), as well as ALP staining, activity and matrix mineralisation. RESULTS: In the nano-58S group, cell proliferation and mRNA expression of ALP, Cbfa1 and OCN were significantly enhanced in a time-dependent manner compared with the control group. mRNA expression of Cbfa1 on day 4 and OCN on day 7 was significantly higher than that in the 58S group. Moreover, there was significantly more ALP protein expression and mineralisation in the nano-58S group than in the 58S group. CONCLUSION: The nano-58S enhanced proliferation, osteogenic markers expression in MG-63 cells and induced stronger mineralization than 58S.

High dietary intake of medium-chain fatty acids during pregnancy in rats prevents later-life obesity in their offspring.

We investigated the effects of dietary fatty acids of different chain lengths during pregnancy in the rat on the susceptibility of offspring to later-life obesity and the underlying mechanisms. Pregnant rats were fed three different diets: standard (STD), high medium-chain fatty acids (MCFA); and high long-chain fatty acids (LCFA). The male offspring were assigned to three groups: STD control, MCFA and LCFA according to the maternal diets and suckled by dams fed with STD during pregnancy and lactation. After weaning, the offspring were fed with STD from 3 to 8 weeks of age. At the age of 8 weeks, rats in three groups: high-fat diet (HFD) control, MCFA and LCFA were fed with HFD until 14 weeks of age in an attempt to induce obesity, and rats in the HFD control group were selected randomly from the STD control group. Body weight and body fat content were decreased in the MCFA group accompanied by down-regulated mRNA expression of fatty acid synthase and acetyl-coA carboxylase 1, and increased mRNA and protein expression of adenosine monophosphate (AMP)-activated protein kinase (AMPK), carnitine palmitoyltransferase 1 and uncoupling protein 3 compared with the corresponding controls at 3, 8 and 14 weeks of age. The results suggested that the MCFA diet during pregnancy prevented later-life obesity in the offspring when they were exposed to HFD in later life, which might be related to programming of the expression of genes involved in fatty acid metabolism.

[Evaluation of adaptation of root canal filled with three obturation techniques in vitro].

OBJECTIVE: To evaluate the adaptation of root canal filled with three obturation techniques in vitro. METHODS: Fifty-seven cleaned and shaped premolars were divided into three groups, each group including 10 single root canal premolars and 9 double root canal premolars, and filled respectively with following techniques: GuttaFlow paste with single master cone (GF group), cold lateral compaction technique with AH plus sealer (LC group), warm vertical compaction technique with AH plus sealer (VC group). The roots were invested and sectioned at 1 mm interval from crown to apex using a microtome saw under water cooling. Both surfaces of the sections were digitally photographed and measured using a stereomicroscope. The number of sections with voids and the area of voids were measured and analyzed. RESULTS: The frequency of sections with voids: VC group (21.4%, 76/355) was significantly lower than GF group (47.7%, 173/363) and LC group (52.6%, 190/361), P < 0.0167. There was no significant difference between GF and LC group (P > 0.0167). The percentage of voids area (AV%): GF group was significantly higher than LC and VC group (P = 0.000, P = 0.008). The median of GF group was 2.67, LC group was 1.55, VC group was 1.01. No significant difference between VC and LC group (P = 0.076). The filling quality of isthmus: 86% (85/99) isthmus were well filled in VC, significantly higher than GF group (55%, 43/78) and LC group (58%, 49/84), P < 0.0167. There was no significant difference between GF and LC group (P > 0.0167). CONCLUSIONS: The adaptation of root canal filled with warm vertical compaction technique was superior to cold lateral compaction technique and GuttaFlow technique.

Effects of supplementation with multivitamin and mineral on blood pressure and C-reactive protein in obese Chinese women with increased cardiovascular disease risk.

OBJECTIVE: To investigate the effect of supplementation with multivitamin and mineral on blood pressure and C-reactive protein (CRP) in obese women with increased cardiovascular disease risk as having hypertension, hyperglycemia or hyperlipemia. SUBJECTS AND METHODS: 128 obese Chinese women aged 18-55 years with increased cardiovascular disease risk participated in a 26-week randomized, double-blind, placebo-controlled trial. Subjects were randomized to four groups, and received either one tablet of high-dose multivitamin and mineral supplement (MMS), or one tablet of low-dose MMS (Low MMS), or calcium 162 mg (Calcium) or identical placebo (Placebo) daily during the study. Diastolic blood pressure (DBP), systolic blood pressure (SBP) and serum concentrations of CRP were measured at baseline and end-trial. RESULTS: At baseline, the subjects had an average age of 42.0+/-7.1 years and BMI of 30.9+/-2.8 kg/m2. There were no significant differences between the four groups in baseline characteristics. One hundred and seventeen subjects completed the study. After 26-week supplementation, both SBP and DBP were significantly lower in the MMS group compared to the placebo group (p < 0.05). There was also a non-significant trend of lower DBP at 26-week in the MMS and calcium groups compared to baseline (p < 0.08). At 26-week, the MMS group also had significantly lower serum concentrations of CRP compared with that of baseline and the placebo group (p < 0.05). CONCLUSIONS: Our results showed that supplementation with adequate multivitamin and mineral supplement could reduce blood pressure and serum CRP in obese women with increased cardiovascular disease risk.