Computer-Aided Designing and Manufacturing of Lingual Fixed Orthodontic Appliance Using 2D/3D Registration Software and Rapid Prototyping

The availability of 3D dental model scanning technology, combined with the ability to register CBCT data with digital models, has enabled the fabrication of orthognathic surgical CAD/CAM designed splints, customized brackets, and indirect bonding systems. In this study, custom lingual orthodontic appliances were virtually designed by merging 3D model images with lateral and posterior-anterior cephalograms. By exporting design information to 3D CAD software, we have produced a stereolithographic prototype and converted it into a cobalt-chrome alloy appliance as a way of combining traditional prosthetic investment and cast techniques. While the bonding procedure of the appliance could be reinforced, CAD technology simplified the fabrication process by eliminating the soldering phase. This report describes CAD/CAM fabrication of the complex anteroposterior lingual bonded retraction appliance for intrusive retraction of the maxillary anterior dentition. Furthermore, the CAD/CAM method eliminates the extra step of determining the lever arm on the lateral cephalograms and subsequent design modifications on the study model

Suppression of STAT3 and HIF-1 Alpha Mediates Anti-Angiogenic Activity of Betulinic Acid in Hypoxic PC-3 Prostate Cancer Cells

Background: Signal transducer and activator of transcription 3 (STAT3) is a transcription factor that regulates various cellular processes such as cell survival, angiogenesis and proliferation. In the present study, we examined that betulinic acid (BA), a triterpene from the bark of white birch, had the inhibitory effects on hypoxia-mediated activation of STAT3 in androgen independent human prostate cancer PC-3 cells. Methodology/Principal Findings: BA inhibited the protein expression and the transcriptional activities of hypoxia-inducible factor-1a (HIF-1a) under hypoxic condition. Consistently, BA blocked hypoxia-induced phosphorylation, DNA binding activity and nuclear accumulation of STAT3. In addition, BA significantly reduced cellular and secreted levels of vascular endothelial growth factor (VEGF), a critical angiogenic factor and a target gene of STAT3 induced under hypoxia. Furthermore, BA prevented in vitro capillary tube formation in human umbilical vein endothelial cells (HUVECs) maintained in conditioned medium of hypoxic PC-3 cells, implying anti-angiogenic activity of BA under hypoxic condition. Of note, chromatin immunoprecipitation (ChiP) assay revealed that BA inhibited binding of HIF-1a and STAT3 to VEGF promoter. Furthermore, silencing STAT3 using siRNA transfection effectively enhanced the reduced VEGF production induced by BA treatment under hypoxia. Conclusions/Significance: Taken together, our results suggest that BA has anti-angiogenic activity by disturbing th

Analysis of surface roughness and surface free energy characteristics of various orthodontic materials

The purpose of this study was to analyze the differences in surface characteristics of various orthodontic materials; this might provide valuable information on bacterial adhesion to orthodontic materials. Methods Surface roughness (SR) and surface free energy (SFE) characteristics of 5 orthodontic adhesives (2 composites resins, 2 resin-modified glass ionomer cements, and 1 compomer), 5 bracket materials (2 stainless steel, 1 monocrystalline sapphire, 1 polycrystalline alumina, and 1 plastic) and bovine incisors were investigated by using confocal laser scanning microscopy and the sessile drop method. Results There were significant differences in SR and SFE characteristics among orthodontic materials. Bovine incisors showed the roughest surface, and monocrystalline sapphire showed the smoothest surface. However, there were only small variations in SR (less than 0.3 μm) among the materials, except for bovine incisors. In contrast to SR, there were big differences in SFE characteristics among materials. Generally, bracket materials showed lower SFE—specifically, dispersive and polar components on their surfaces—than orthodontic adhesives. Resin-modified glass ionomer cements had the highest SFE, dispersive component, and polarity; these conditions are more favorable for bacterial adhesion. Conclusions This study suggests that SFE characteristics can influence bacterial adhesion to orthodontic materials more than SR, and bracket materials might have less favorable SFE characteristics for bacterial adhesion than orthodontic adhesives.Supported by a grant of the Korea Healthcare Technology R&D Project, Ministry for Health, Welfare and Family Affairs, Republic of Korea (A091074)

Assessment of safety and efficacy against Bordetella pertussis of a new tetanus-reduced dose diphtheria-acellular pertussis vaccine in a murine model

Abstract Background Tetanus-reduced dose diphtheria-acellular pertussis (Tdap) vaccination during adolescence was introduced in response to the resurgence of pertussis in various countries. A new Tdap vaccine was manufactured in Korea as a countermeasure against a predicted Tdap vaccine shortage. This study was performed to evaluate the immunogenicity, safety, and protection efficacy against Bordetella pertussis of the new Tdap vaccine in a murine model. Methods Four-week-old BABL/c mice were used for assessment of immunogenicity and protection efficacy. A single dose of primary diphtheria-tetanus-acellular pertussis (DTaP) vaccine was administered, followed by a single dose of Tdap booster vaccine after a 12-week interval. Anti-pertussis toxin (PT), anti-filamentous hemagglutinin (FHA), and anti-pertactin (PRN) IgG titers were measured before primary vaccination, and before and after booster vaccination. An intranasal challenge test was performed after booster vaccination to determine protection efficacy. To assess safety, mouse weight gain test and leukocytosis promotion test were performed using 4-week-old ddY female mice. Results Anti-PT and anti-FHA IgG titers after booster vaccination were significantly higher than those before booster vaccination with either the new vaccine or a commercially available Tdap vaccine (P = 0.01 for all occasions). After booster vaccination, no significant difference was observed between the two vaccines in antibody titers against pertussis antigens (P = 0.53 for anti-PT IgG, P = 0.91 for anti-FHA IgG, P = 0.39 for anti-PRN IgG). In the intranasal challenge test, inoculated B. pertussis was eradicated 7 days after infection. On days 4 and 7 after infection, colony counts of B. pertussis were not significantly different between the new and positive control vaccine groups (P = 1.00). Mean body weight changes and leukocyte counts of the new vaccine, positive control, and negative control groups were not significantly different 7 days after vaccination (P = 0.87 and P = 0.37, respectively). All leukocyte counts in the new vaccine group were within a mean ± 3 standard deviations range. Conclusions A murine model involving a single dose primary DTaP vaccination followed by a single dose Tdap booster vaccination can be used for non-clinical studies of Tdap vaccines. The new Tdap vaccine manufactured in Korea exhibited comparable immunogenicity, protection efficacy, and safety with a commercially available Tdap vaccine

Chemical structure of betulinic acid (BA).

<p>Molecular weight  =  456.</p

Effect of betulinic acid (BA) on hypoxia-induced STAT3 activation in PC-3 cells.

<p>PC-3 cells were treated with or without BA (5 or 10 µM) under normoxic or hypoxic condition for 4 h. (A) Cell lysates were prepared and subjected to Western blotting for phospho-STAT3 and STAT3. (B) Nuclear extracts were prepared and applied to EMSA to analyze the STAT3-DNA binding activity. (C) Cells were treated with or without BA (10 µM) under hypoxia. Immunocytochemistry was performed for STAT3. DAB (brown) and hematoxylin-eosin was used as a substrate and a counterstaining, respectively.</p

Effect of betulinic acid (BA) on STAT3 binding on the VEGF promoter in hypoxic PC-3 cells.

<p>(A) PC-3 cells were treated with or without BA (10 µM) under normoxia or hypoxia for 4 h. The immunoprecipitated DNA with rabbit normal IgG, HIF-1α or STAT3 antibody was amplified by PCR analysis for VEGF promoter. (B) Cells were transiently transfected with siRNA for scramble or STAT3 for 24 h and treated with or without BA (10 µM) for 18 h under hypoxia. VEGF levels in the culture supernatants were measured by using a Quantikine VEGF ELISA kit. Data represent means ± S.D. ^#, p<0.05 <i>vs</i> control, and ^*, p<0.05 <i>vs</i> control siRNA. Cell lysates were subjected to Western blotting for phospho-STAT3, STAT3 and HIF-1α.</p

Effect of betulinic acid (BA) on hypoxia-induced HIF-1α activation in PC-3 cells.

<p>(A) PC-3 cells were treated with various concentrations of BA (0, 12.5, 25, 50 or 100 µM) for 24 h. Cell viability was analyzed by MTT assay. (B) Cells were exposed to normoxia or hypoxia for 0.5, 2, 4, 6, 8, 12 or 24 h. Cell lysates were prepared and subjected to Western blotting to determine the expression of HIF-1α. (C) Cells were treated with or without BA (5 or 10 µM) under normoxic or hypoxic condition for 4 h. Cell lysates were prepared and subjected to Western blotting to determine the expression of HIF-1α. (D) Nuclear extract was prepared from the cells treated with BA (0, 10, 20 or 40 µM) under normoxia or hypoxia for 4 h. HIF-1α transcription activity was measured by using TransAM HIF-1 transcription factor assay kit. Data represent means ± S.D. ^##, p<0.01 <i>vs</i> normoxia control, and ^*, p<0.05 and ^** < 0.01 <i>vs</i> hypoxia control.</p

Effect of betulinic acid (BA) on hypoxia-induced angiogenesis.

<p>(A and B) PC-3 cells were treated with 0, 5 or 10 µM BA for 24 h. (A) VEGF levels in the culture supernatants were measured by using a Quantikine VEGF ELISA kit. (B) Cell lysates were prepared and subjected to Western blotting to determine VEGF expression. Graphs represent relative band intensities of VEGF/β-actin. Data represent means ± S.D. ^##, p<0.01 <i>vs</i> normoxia control, and ^*, p<0.05 and ^** <0.01 <i>vs</i> hypoxia control. (C) HUVECs were treated with VEGF (20 ng/ml) as positive control or the culture supernatant from PC-3 cells treated with or without BA (10 µM) under normoxia or hypoxia. Tube formation assay was performed using growth factor reduced Matrigel. Cells were fixed with Diff-Quick solution, photographed randomly under an Axiovert S 100 light microscope at ×100 magnification and counted.</p