BACKGROUNDThe rocking and instability of a loaded complete denture (CD) during lateral excursion reduce the bearing area under the denture base, causing localized high stress concentrations. This can lead to mucosal tenderness, ulceration, and alveolar bone resorption, and the linear occlusion design was to decrease the lateral force exerted on the denture and to ensure denture stability. But it is not known how the bearing areas of linear occlusal CDs (LOCDs) and anatomic occlusal CDs (AOCDs) differ. The purpose of this study was to analyze and compare the distributions of the high and low vertical stress-bearing areas in the mandibular alveolar mucosa under LOCDs and AOCDs at lateral excursion.

METHODSComputerized tomography (CT) and finite element analysis were used to establish three-dimensional models of an edentulous maxilla and mandible with severe residual ridge resorption. These models were composed of maxillary and mandibular bone structure, mucosa, and the LOCD or AOCD. Lateral excursion movements of the mandible were simulated and the vertical stress-bearing areas in the mucosa under both mandibular CDs were analyzed using ANSYS 7.0.

RESULTSOn the working side, the high stress-bearing (-0.07 to -0.1 MPa) area under the LOCD during lateral excursion was smaller than that under the AOCD, while the medium stress-bearing (-0.03 to -0.07 MPa) area under the LOCD was 1.33-fold that under the AOCD. The medium stress-bearing area on the non-working side under the LOCD was 2.4-fold that under the AOCD. Therefore, the overall medium vertical stress-bearing area under the LOCD was 20% larger than that under the AOCD.

CONCLUSIONSDuring lateral excursion, the medium vertical stress-bearing area under a mandibular LOCD was larger and the high vertical stress-bearing area was smaller than that under an AOCD. Thus, the vertical stress under the LOCD was distributed more evenly and over a wider area than that under the AOCD, thereby improving denture stability.

Aged ; Computer Simulation ; Dental Occlusion ; Dental Stress Analysis ; Denture, Complete ; Female ; Finite Element Analysis ; Humans ; Mandible ; physiology ; Stress, Mechanical

OBJECTIVEThe purpose of this article is to examine the effect of curcumin on the proliferation and metastasis of human tongue squamous cell carcinoma and analyze its mechanism.

METHODSSCC-4 were treated with curcumin of 0, 5, 10, 20, 30, 60, 100 micromol x L(-1) in 24 h. MTT assay, Matrigel invasion assay, flow cytometry and fluorescence microscopy were used to examine the effect of curcumin on the growth and metastasis of SCC-4. cDNA microarray and RT-PCR were employed to analyze the expression of genes treated by curcumin.

RESULTSThe results showed that curcumin could concentration-dependently inhibit SCC-4 cell proliferation at the concentration range from 20 to 100 micromol x L(-1). Furthermore, Matrigel invasion assay indicated that curcumin can reduce SCC-4 cell invasion under the dosage of 20, 30, 60 micromol x L(-1). Flow cytometry also showed that curcumin can influence the distribution of cell cycle of SCC-4 cell with the dosage of 20, 30, 60 micromol x L(-1). And the dosage of 30 micromol x L(-1) curcumin could lead to the recruitment of alpha-tubulin. cDNA microarray showed that 87 genes were activated and 198 genes were inhibited with the effect of curcumin. These results were validated by the real time quantitative RT-PCR.

CONCLUSIONAccording to the results, it suggests that curcumin has the potential as the leading compound for anti-cancer proliferation and invasion in oral cancer treatment, and cdc27, EGFR substrate 15, PPAR-alpha and H2A histone may play an important role among this multiple anticancer-targeting ability.

Cell Line, Tumor ; Cell Proliferation ; Curcumin ; Humans ; Mouth Neoplasms

Objective: To distinguish Rhizoma curcuma of different origins using headspace-gas chromatography/mass spectrometry (HS-GC/MS) combined with principal components analysis (PCA) and hierarchical cluster analysis (HCA), so as to help the quality control of Rhzzoma curcuma. Methods: HP-5 capillary column (30 m×0. 32 mm, 0. 25 μm) was used under the following condition; inlet temperature; 250°C, initial column temperature; 50°C maintained for 3 min, then increasing to 150°C at 20°C/min and to 200°C at 2°C/min, maintained for 10 min, with the split ratio being 10 : 1. The carrier gas was helium, with flow rate being 1. 0 mL/min, had space vials regional temperature being 90°C, vials heating equilibration time being 30 min, and injection volume being 1. 5 mL. The effect of extract separation conditions, temperature of the vial and equilibrium time on the extraction volatile components of RMzoma curcuma were observed. Results: PCA could distinguish 18 common peaks of 15 batches of Rhizoma curcuma from Sichuan, Guangxi and Yunnan, and it was confirmed that (3-elemene, camphene, 13-pinene, p-menth-l-en-8-ol, eucalyptol, and cycloisolongifolene, 8, 9-dehydro-9-formyl were the main components to cause differences in RMzoma curcuma of different origins. Conclusion: We have established a method combining HS-GC/MS with PCA and HCA to distinguish RMzoma curcuma of different origins, and we have also identified the major characteristic components of Rhizoma curcuma of different origins.

To identify the active constituents in vitro and blood-absorbed ingredients in vivo from Yin Chen Hao decoction provides scientific evidence for probing its prevention and treatment mechanism on acute liver injury. An ultrahigh performance liquid chromatography quadrupole-time of flight-mass spectrometry (UPLC-QTOF/MS) method was applied for analysis of Yin Chen Hao decoction and the serum samples of mice with con-A induced acute liver injury after preventive oral administration for 14 days (the use of all laboratory animals in this study was approved by the Ethics Committee of the Naval Medical University, 19YF1459400). A total of 90 chemical constituents were identified from Yin Chen Hao decoction, mainly were flavonoids, terpenoids, tannins, quinones. 5 prototype compounds were identified in the serum, including chrysophanol, deoxyrhapontin-8-O-gallate, mussaenosidic acid, herniarin, emodin. The established UPLC-QTOF/MS method could efficiently and sensitively identify the constituents in vitro and blood-absorbed ingredients of Yin Chen Hao decoction, primarily clarify the material basis of its hepatoprotective effect, and provided a scientific basis for the quality marker selection and the pharmacodynamic material basis research on the decoction.

In this study, the effect of benzo[α]pyrene (BaP) on chaperone-mediated autophagy (CMA) in a simulated hypoxia environment was observed and the relationship to heat shock protein 90 (HSP90) was clarified. With HSP90 inhibitor geldanamycin (GA) and HSP90α silenced, the mRNA and protein expression of hypoxia-inducible factor-1α (HIF-1α), HSP90, heat shock cognate protein 70 (HSC70), and lysosomal associated protein 2A (LAMP-2A) of A549 cells on hypoxic environment by BaP were tested. Alkaline comet experiment, immunofluorescence γ-H2AX focus experiment, quantitative real-time PCR (qPCR), and Western blot analyses were used to clarify the relationship between the DNA damage of different concentrations of BaP in A549 cells and the mRNA and protein expression of CMA-related factors. The results show that hypoxia can promote the expression of mRNA and protein of CMA-related factors in A549 cells. This study found that BaP has an inhibitory effect on CMA under the hypoxic environment. The inhibition or silencing of HSP90 will enhance the inhibitory effect of BaP on CMA. In a normoxic environment, BaP causes DNA damage and promotes CMA.