[Effects of mineral trioxide aggregate and ethanolic extracts of Shandong propolis on the biological properties of human dental pulp fibroblasts].

OBJECTIVE: To evaluate the effect of mineral trioxide aggregate (MTA) and propolis from Shangdong province on the cell viability, mineralization and migration and anti-inflammatory ability of dental pulp fibroblasts. METHODS: The human dental pulp fibroblasts were cultured and subjected to 10 mg/L of propolis and 1:8 dilution of MTA extraction. The cell viability was evaluated with cell counting kit-8 (CCK-8) after 1, 5, 7 and 9 days. The cells in the upper inserts and the test culture media on the bottoms of 24-well plates interacted for 15 hours. Then the numbers of cells migrated through the permeable membranes were compared. The cells seeded in the 24-well plates were incubated in osteogenic medium with different materials for 21 days and stained with alizarin red S, then photographed. To evaluate the deposition of calcified matrix, the wells were destained with 100 mmol/L cetylpyridinium chloride. Finally, the cells were exposed to 1 mg/L lipopolysaccharide (LPS) to induce an inflammatory response, in the presence of propolis, MTA extraction. The cells were collected after 3 h, and the expressions of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) were determined using real-time polymerase chain reaction (real-time PCR). Statistical analysis was performed by one-way ANOVA and nonparametric tests (P<0.05). RESULTS: The cell viability of propolis group was significantly lower than those of MTA and control groups on days 5, 7 and 9, while MTA significantly increased the numbers of the viable cells on days 7 and 9. The migration cells of propolis group (26.67±2.52) were fewer than control group (61.33±4.93), and the cells of MTA group (80.00±2.65) were statistically more than those of the other two groups. The propolis group significantly induced more calcified matrix deposition than MTA group after 21 days of culture. Propolis significantly suppressed the expressions of IL-1ß and IL-6 after LPS exposure compared with MTA and control groups. CONCLUSION: The propolis from Shandong compared with MTA showed a certain degree of cytotoxicity, and had no significant effect on cell migration. On the other hand, propolis exhibited significant anti-inflammatory and mineralization promotion effect, suggesting that the active ingredients of propolis could be introduced as a supplement of pulp capping materials, or used as an irrigant or intracanal medicament due to its excellent anti-inflammatory effect. Propolis may have potential in vital pulp treatment of young permanent tooth suffering pulp inflammation.

Effect of propolis on preserving human periodontal ligament cells and regulating pro-inflammatory cytokines.

BACKGROUND/AIM: Propolis has been suggested as a storage medium for avulsed teeth. The aim of this study was to compare the effectiveness of Brazilian propolis with Hank's balanced salt solution and milk in maintaining the viability of human periodontal ligament cells, their osteogenic differentiation potential, and pro-inflammatory cytokine expression. MATERIAL AND METHODS: Cell Counting Kit 8 assays were performed to test human periodontal ligament cell viability in different storage media. The preservative effect on osteogenic differentiation was evaluated using alkaline phosphatase staining and activity assays, Alizarin Red S staining, and western blotting. Quantification of pro-inflammatory cytokines was performed using real-time PCR and enzyme-linked immunosorbent assays. RESULTS: Brazilian propolis at 10 µg/ml was not cytotoxic toward human periodontal ligament cells. The milk group showed the highest cell viability. Brazilian propolis and Hank's balanced salt solution groups showed similar cell viabilities. Alkaline phosphatase staining and activity were similar in all groups. Calcium deposition and mineralization nodule formation were similar in the Brazilian propolis and Hank's balanced salt solution groups, but were higher in the milk group. Osteogenic marker gene and protein levels were similar in all groups. The genes and protein expression levels of IL1ß, IL6, and IL8 decreased significantly after treatment with Brazilian propolis. TNFα mRNA expression showed no significant difference among the experimental groups. Pro-inflammatory cytokine levels in the milk group were higher than in the Brazilian propolis and Hank's balanced salt solution groups. CONCLUSIONS: Brazilian propolis, Hank's balanced salt solution, and milk maintained the viability of human periodontal ligament cells and preserved their osteogenic differentiation ability similarly. However, Brazilian propolis showed a better anti-inflammatory effect. This article is protected by copyright. All rights reserved.

HLA-B*13:01 and the dapsone hypersensitivity syndrome.

BACKGROUND: Dapsone is used in the treatment of infections and inflammatory diseases. The dapsone hypersensitivity syndrome, which is associated with a reported mortality of 9.9%, develops in about 0.5 to 3.6% of persons treated with the drug. Currently, no tests are available to predict the risk of the dapsone hypersensitivity syndrome. METHODS: We performed a genomewide association study involving 872 participants who had received dapsone as part of multidrug therapy for leprosy (39 participants with the dapsone hypersensitivity syndrome and 833 controls), using log-additive tests of single-nucleotide polymorphisms (SNPs) and imputed HLA molecules. For a replication analysis, we genotyped 24 SNPs in an additional 31 participants with the dapsone hypersensitivity syndrome and 1089 controls and performed next-generation sequencing for HLA-B and HLA-C typing at four-digit resolution in an independent series of 37 participants with the dapsone hypersensitivity syndrome and 201 controls. RESULTS: Genomewide association analysis showed that SNP rs2844573, located between the HLA-B and MICA loci, was significantly associated with the dapsone hypersensitivity syndrome among patients with leprosy (odds ratio, 6.18; P=3.84×10(-13)). HLA-B*13:01 was confirmed to be a risk factor for the dapsone hypersensitivity syndrome (odds ratio, 20.53; P=6.84×10(-25)). The presence of HLA-B*13:01 had a sensitivity of 85.5% and a specificity of 85.7% as a predictor of the dapsone hypersensitivity syndrome, and its absence was associated with a reduction in risk by a factor of 7 (from 1.4% to 0.2%). HLA-B*13:01 is present in about 2 to 20% of Chinese persons, 1.5% of Japanese persons, 1 to 12% of Indians, and 2 to 4% of Southeast Asians but is largely absent in Europeans and Africans. CONCLUSIONS: HLA-B*13:01 was associated with the development of the dapsone hypersensitivity syndrome among patients with leprosy. (Funded by the National Natural Science Foundation of China and others.).

[Phylogenetic analysis of Echinococcus granulosus genotypes based on the GenBank database].

OBJECTIVE: To analyze the sequences of the cytochrome C oxidase subunit I (Cox1) gene of various Echinococcus granulosus genotypes that are currently recorded in the GenBank database, so as to investigate the genetic variation and differentiation of the E. granulosus genotypes across the world. METHODS: The sequences of the Cox1 gene of various E. granulosus genotypes that are currently recorded in the GenBank database were collected, and the same sequences of the Cox1 gene identified from a region were excluded. The mutation sites among the Cox1 gene sequences were identified and a phylogenetic tree was created based on the Cox1 gene. RESULTS: Transversion mutation was the predominant type of mutation in the Cox1 gene of E. granulosus. The same Cox1 gene sequence was found in E. granulosus G1, G6 and G7 genotypes isolated from various geographical locations across the world, with the corresponding GenBank accession numbers of KY766891, MH300971 and MH301007, respectively. Phylogenetic analysis revealed that E. granulosus G10 genotype had a remarkable geographical aggregation. CONCLUSIONS: E. granulosus G1, G6 and G7 genotypes have primitive Cox1 gene sequences. There is a geographical aggregation of the E. granulosus G10 genotype in the phylogenetic tree, which has a tendency towards reproductive isolation.

Evolution of dendritic patterns during alloy solidification: onset of the initial instability.

The evolution of a dendritic pattern from a planar solid-liquid interface during directional solidification of a binary alloy was investigated experimentally. The model alloy used was the transparent organic crystal succinonitrile doped with the laser dye coumarin 152. The buildup of solute ahead of the initially stable planar interface and the subsequent instability of the planar front were measured in detail and compared with recent theoretical calculations by Warren and Langer [Warren, J. A. & Langer, J. S. (1993) Phys. Rev. E 47, 2702- 2712]. The fluorescence of coumarin 152 was used for direct observations of the evolution of the solute concentration profile ahead of the initially planar solid-liquid interface. UV absorption was used to produce thermal perturbations of the sample that generated spatially periodic modulations of the planar interface. This technique allows for measurement of both positive and negative linear growth coefficients (determined from the growth or decay rate of the modulation after the perturbation is switched off) for a large range of wave vectors. Measurements of the evolution of the concentration profile and the linear growth coefficients, and the occurrence of the initial instability, were in good agreement with the Warren-Langer predictions.

Evolution of dendritic patterns during alloy solidification: From the initial instability to the steady state.

The evolution of the crystal-melt interface was investigated during directional solidification of a dilute binary alloy, starting at the marginal stability time t(i) at which the planar interface first becomes unstable. The time delay between t(i) and the crossover time t(0) at which the interface modulation becomes observable was determined experimentally. The interface morphology was analyzed as the cellular pattern appeared, and it was followed through the coarsening phase to the final steady-state dendritic pattern. The relevance of the initial instability for steady-state pattern selection was verified experimentally, and some aspects of the coarsening dynamics were measured and compared with theoretical predictions of Warren and Langer [Warren, J. A. & Langer, J. S. (1990) Phys. Rev. A 42, 3518-3525; Warren, J. A. & Langer, J. S. (1993) Phys. Rev. E 47, 2702-2712].

Two-step isolation of bacterial ribonucleic acid without using a chaotropic agent or cesium chloride centrifugation.

A simple RNA isolation method was developed to purify bacterial RNAs from a large number of samples simultaneously in an hour. The method is based on boiling the cells in the presence of Triton X-100 and lysozyme, and then preferential RNA precipitation with ammonium acetate. There is no CsCl centrifugation required. For the nitrogen-fixing bacterium Klebsiella pneumoniae, the depression condition can be maintained during the cell-harvesting process. The intact isolated RNAs appeared to be free of protein, with a yield of 100 micrograms RNA from a 4-ml cell culture of 100 Klett units (10(9) cells/ml). Any DNA present was in a form that did not react with a nifH probe following Northern blotting to nitrocellulose (i.e., was not single-stranded).