HALO CleanSpace PAPR evaluation: Communication, respiratory protection, and usability.

OBJECTIVE: To evaluate a relatively new half-face-piece powered air-purifying respirator (PAPR) device called the HALO (CleanSpace). We assessed its communication performance, its degree of respiratory protection, and its usability and comfort level. DESIGN AND SETTING: This simulation study was conducted at the simulation center of the Royal Melbourne Hospital. PARTICIPANTS: In total, 8 voluntary healthcare workers participated in the study: 4 women and 4 men comprising 3 nursing staff and 5 medical staff. METHODS: We performed the modified rhyme test, outlined by the National Institute for Occupational Safety and Health (NIOSH), for the communication assessment. We conducted quantitative fit test and simulated workplace protection factor studies to assess the degree of respiratory protection for participants at rest, during, and immediately after performing chest compression. We also invited the participants to complete a usability and comfort survey. RESULTS: The HALO PAPR met the NIOSH minimum standard for speech intelligibility, which was significantly improved with the addition of wireless communication headsets. The HALO provided consistent and adequate level of respiratory protection at rest, during and after chest compression regardless of the device power mode. It was rated favorably for its usability and comfort. However, participants criticized doffing difficulty and perceived communication interference. CONCLUSIONS: The HALO device can be considered as an alternative to a filtering face-piece respirator. Thorough doffing training and mitigation planning to improve the device communication performance are recommended. Further research is required to examine its clinical outcomes and barriers that may potentially affect patient or healthcare worker safety.

Enhancing production of herpes simplex virus type 1 in oral epithelial cells by co-infection with Aggregatibacter actinomycetemcomitans.

BACKGROUND/PURPOSE: The association between herpetic/bacterial co-infection and periodontal diseases has been reported. However, how interactions between herpesviruses and periodontal bacteria dampen periodontal inflammation is still unclear. This study determined effects of co-infection with oral bacteria, including Streptococcus sanguinis, Fusobacterium nucleatum or Aggregatibacter actinomycetemcomitans, in herpes simplex virus type 1 (HSV-1)-infected oral epithelial cells. METHODS: Cell viability was determined by detection the activity of mitochondrial dehydrogenase. Viral production was measured using the plaque assay. Levels of bacterial and viral DNA were determined by real-time polymerase chain reaction. Secretion of interleukin (IL)-6 and IL-8 was measured using the enzyme-linked immunosorbent assay. RESULTS: Viability was not further reduced by bacterial co-infection in HSV-1-infected cells. Co-infection with HSV-1 and S. sanguinis or F. nucleatum reduced the viral yield whereas co-infection with HSV-1 and A. actinomycetemcomitans significantly enhanced the viral yield in oral epithelial cells. The enhancing effect of A. actinomycetemcomitans was not affected by bacterial heat-inactivation. Co-infection with HSV-1/A. actinomycetemcomitans increased intracellular levels of both viral and bacterial DNA. Secretion of IL-6 and IL-8 stimulated by A. actinomycetemcomitans infection was partly reduced by co-infection with HSV-1 in oral epithelial cells. CONCLUSION: In contrast to S. sanguinis and F. nucleatum, A. actinomycetemcomitans enhanced the yield of HSV-1. Either HSV-1 or A. actinomycetemcomitans may be benefited from co-infection, in aspects of increases in production of viral and bacterial DNA as well as reductions in cytokine secretion. These findings echoed with previous clinical studies showing co-infection of HSV and A. actinomycetemcomitans in patients with aggressive periodontitis.

Modulation of proinflammatory mediators by viruses-bacteria synergism in human osteoblasts-an in vitro study.

BACKGROUND/PURPOSE: Viruses-bacteria synergistic interaction is associated with destructive periodontal diseases. However, the underlying mechanism for tissue destruction is not fully elucidated. In this study, lipopolysaccharide from Porphyromonas gingivalis (Pg-LPS) and polyinosinic-polycytidylic acid (poly I:C) were used to simulate bacteria and viruses, respectively. The possible combined effects of both molecular patterns on secretion of interleukin (IL)-6 and prostaglandin E2 (PGE2) from osteoblasts were determined. The effects of povidone-iodine (PVP-I) on the secretion of IL-6 and PGE2 were also examined. METHODS: Viability of treated osteoblastic cells (MG63) was examined by detection the mitochondrial dehydrogenase activity. Secretion of IL-6 and PGE2 was detected using the enzyme-linked immunosorbent assay (ELISA). Mitogen-activated protein kinases (MAPKs) and cyclooxygenase-2 (COX-2) were determined using the Western blotting analysis. RESULTS: Pg-LPS or poly I:C significantly enhanced the production of IL-6 and PGE2 in MG63 cells. The additive/synergistic effects of Pg-LPS/poly I:C on production of IL-6 and PGE2 were evident. The levels of phosphorylation of p38 MAPK and c-Jun N-terminal kinase (JNK) and expression of COX-2 protein were enhanced by Pg-LPS and/or poly I:C. On the other hand, the level of phosphorylation of extracellular signal-regulated kinase (ERK) was reduced by Pg-LPS and/or poly I:C. The stimulatory secretion of PGE2 by poly I:C was significantly reduced by PVP-I. CONCLUSION: Concomitant infection of viruses and bacteria may be potentially harmful to the tooth supporting tissues by production of proinflammatory mediators. The results suggest the potential anti-inflammatory effect of PVP-I on bacterial or viral infection.

The role of fibroblasts in the modulation of dental pulp inflammation.

BACKGROUND/PURPOSE: Dental pulp fibroblasts can protect dental pulp from microbial invasion. However, little is known about the interaction between pulp fibroblasts and the immune cells. In this study, the production of proinflammatory cytokines related to inflammatory cell recruitment was evaluated in tumor necrosis factor (TNF)-α-stimulated human dental pulp fibroblasts (HDPFs). The role of TNF-α-stimulated HDPFs in the cell fusion under inflammatory process was determined with the cell co-culture with peripheral blood mononuclear cells (PBMCs). METHODS: HDPFs were stimulated with various concentrations of TNF-α, and the secretion of interleukin (IL)-6, IL-8 and monocyte chemoattractant protein (MCP)-1 was analyzed by the enzyme-linked immunosorbent assay. The mRNA expression levels of intercellular adhesion molecule-1 (ICAM-1), macrophage colony-stimulating factor (M-CSF), receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG) were determined by real-time quantitative polymerase chain reaction. TNF-α-treated HDPFs were co-cultured with PBMCs for 21 days, and characteristics of cell differentiation were assessed. RESULTS: TNF-α induced IL-6, IL-8 and MCP-1 production in HDPFs. Moreover, mRNA expression levels of ICAM-1, M-CSF and OPG were significantly increased in TNF-α-treated HDPFs. Co-culture of TNF-α-treated HDPFs and PBMCs stimulated formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells, and the F-actin rings were observed in these multinucleated cells. CONCLUSION: Our results indicate that under the stimulation of TNF-α, HDPFs may amplify inflammatory response by cytokines production, which in turn can modulate the differentiation of immune cells.

Flexural Behavior of Ultra-High-Performance Fiber-Reinforced Concrete Beams after Exposure to High Temperatures.

Due to the dense structure of ultra-high-performance concrete (UHPC), it is prone to explosive spalling at high temperatures. In this paper, flexural testing of UHPC and high-strength concrete (HSC) beams was carried out at room temperature and after being subjected to different levels of thermal exposure (300-500 °C). The cross-section of the beam specimen was 150 (width) × 200 (depth) mm, and its length was 1500 mm. The flexural and shear design of the beam specimens were carried out in accordance with the ACI 318M-14 code. All of the beams were singly reinforced with two #4 rebars (minimum reinforcement ratio) as a longitudinal tensile reinforcement at the bottom of the specimen and at an effective depth of 165 mm. The flexural load was applied using the three-point load method. The results show that, at room temperature and after being subjected to different thermal exposures, compared with the HSC specimens, the stiffness of the UHPC specimens in the post-cracking stage was relatively larger and the deflection under a given load was smaller. Moreover, whether at room temperature or after exposure to different thermal exposures, the ductility of the UHPC specimens was better than that of the HSC specimens.

Effects of epigallocatechin-3-gallate and acyclovir on herpes simplex virus type 1 infection in oral epithelial cells.

BACKGROUND/PURPOSE: Herpes simplex virus type 1 (HSV-1) is the pathogenic agent of human diseases, including gingivostomatitis and herpes labialis. The anti-viral activities of the tea polyphenol, epigallocatechin-3-gallate (EGCG), have been demonstrated. This study examined the combined effects of EGCG and the antiviral drug, acyclovir (ACV), on infection of HSV-1 in oral epithelial cells. METHODS: Cell viability was examined using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide. Viral yields were determined using the plaque assay. Viral proteins were detected using Western blotting analysis or confocal laser scanning microscopy. Viral DNA was detected using the real-time polymerase chain reaction. RESULTS: Cytotoxic effects of HSV-1 on the viability of oral epithelial cells were evidently reduced in the presence of EGCG (25 µg/ml) or/and ACV (50 µg/ml). Viral yields were also significantly reduced by treatment of cells with EGCG or/and ACV. Expression of viral immediate early protein, infected cell protein 0 (ICP0), was greatly inhibited when cells were treated with EGCG. Combined effects of EGCG and ACV were more evident for the expression of viral thymidine kinase, ICP5 and glycoprotein D. EGCG, but not ACV, significantly reduced the levels of viral particles and viral DNA during viral entry phase. However, at 20 h post infection, the intracellular viral DNA was evidently reduced in HSV-1 infected cells treated with EGCG and ACV. Moreover, the stimulatory effects of HSV-1 on phosphorylation of c-Jun N-terminal kinase could be reduced by ACV. CONCLUSION: The results demonstrated the additive effects of EGCG and ACV on HSV-1 infection in oral epithelial cells.

Stimulatory effects of Porphyromonas gingivalis GroEL protein on interleukin-6 and interleukin-8 in human osteoblasts.

BACKGROUND/PURPOSE: Porphyromonas gingivalis is an oral pathogen associated with periodontal diseases. P. gingivalis GroEL protein is a stimulator of inflammatory cytokines in macrophages. This study inspected effects of P. gingivalis GroEL protein on production of interleukin (IL)-6 and IL-8 by human osteoblasts. METHODS: Viability of GroEL-treated osteoblasts was analyzed with 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide. Secretion of IL-6 and IL-8 was analyzed using the enzyme-linked immunosorbent assay. Levels of mRNA were analyzed using the reverse transcription and real-time polymerase chain reaction. The antioxidant (curcumin), the p38 mitogen-activated protein kinase (MAPK) inhibitor (SB203580) and the c-Jun N-terminal kinase (JNK) inhibitor (SP600125) were employed to elucidate possible signaling pathways involved. RESULTS: Treatment with GroEL did not affect morphology and viability of osteoblasts. GroEL significantly induced the secretion of IL-6 and IL-8 by osteoblasts in a concentration-dependent pattern. Moreover, the mRNA levels of IL-6 and IL-8 were stimulated by GroEL. The application of SP600125 (10 µM) significantly suppressed the induction of IL-6 and IL-8 by GroEL-treated cells. However, curcumin (20 µM) and SB203580 (20 µM) only down-regulated the stimulatory effects of GroEL on IL-6. CONCLUSION: GroEL protein stimulated the inflammatory reaction of osteoblasts, probably through the activation of p38 MAPK or JNK pathway. The findings suggest that P. gingivalis GroEL may influence the immune functions of osteoblasts and endanger the periodontal health.

Citronellol Induces Necroptosis of Human Lung Cancer Cells via TNF-α Pathway and Reactive Oxygen Species Accumulation.

BACKGROUND/AIM: Our current study aimed to determine the molecular mechanisms of citronellol-induced cell death and ROS accumulation in non-small cell lung cancer (NCI-H1299 cells) and also compare the anticancer effects of citronellol and EOPC. MATERIALS AND METHODS: ROS measurement and western blotting were performed to detect whether citronellol can induce necroptosis in vitro. Besides, we performed an in vivo analysis of tumourigenesis inhibition by citronellol treatment in BALB/c (nu/nu) nude mice. RESULTS: Necroptosis occured by up-regulating TNF-α, RIP1/RIP3 activities, and down-regulating caspase-3/caspase-8 activities after citronellol treatment in NCI-H1299 cells. Citronellol also resulted in a biphasic increase in ROS production at 1 h and at 12 h in NCI-H1299 cells. Xenograft model experiments showed that citronellol could effectively inhibit subcutaneous tumours produced 4 weeks after intraperitoneal injection of NCI-H1299 in BALB/c nude mice. CONCLUSION: Citronellol induced necroptosis of NCI-H1299 cells via TNF-α pathway and ROS accumulation.

Inhibition of Streptococcus mutans by a commercial yogurt drink.

BACKGROUND/PURPOSE: Studies have been focused on using probiotics to prevent caries. The lactobacillus probiotic bacteria in Yakult® (LcY) has been shown to inhibit the growth or biofilm formation of Streptococcus mutans. However, sucrose in Yakult® raised concerns. The purpose of this study was to determine effects of Yakult® on the growth and adhesion of S. mutans. MATERIALS AND METHODS: S. mutans was grown in serial diluted Yakult®, filtered Yakult® or 20% heated Yakult®. S. mutans was co-cultured with LcY in media with or without diluted filtered Yakult®, or in LcY grown in media with or without sugars. Colony forming units and pH values of bacterial cultures were determined. SYTO 9-stained adhered bacteria were observed. RESULTS: Yakult® inhibited the growth of S. mutans. Filtering or heating Yakult® reduced its inhibitory ability against S. mutans. The inhibitory effect of LcY against S. mutans was enhanced when cultured in the presence of 20% filtered Yakult®. LcY cultured in sucrose media for 24 h inhibited the growth of S. mutans, but this effect was less evident when LcY was grown for 48 h. LcY grown in glucose or lactose media similarly reduced S. mutans growth. Culturing S. mutans with LcY grown in sucrose or glucose media reduced bacterial adhesion. However, co-culturing S. mutans with LcY grown in the lactose media did not decrease bacterial adhesion. CONCLUSION: Yakult® and its probiotic content may inhibit S. mutans growth and the effect may be moderated by the type of sugar added for LcY cultivation.

Inhibitory effects of tea catechin epigallocatechin-3-gallate against biofilms formed from Streptococcus mutans and a probiotic lactobacillus strain.

OBJECTIVE: Effects of tea catechin epigallocatechin-3-gallate (EGCG) against biofilm formation by Streptococcus mutans and probiotic Lactobacillus casei in Yakult® (LcY) were examined. DESIGN: Biofilms were formed by S. mutans alone (Sm) and co-culture of S. mutans and LcY (Sm + LcY) in the absence or presence of EGCG. The biomass of biofilms, which were sonicated or not, was measured by the crystal violet assay. Biofilm morphology was observed by scanning electron microscopy. Bacterial viability and extracellular polysaccharides were determined by SYTO9/propidium iodide and dextran-conjugated fluorescein staining, respectively, and confocal microscopy. Gene expression of glucosyltransferase was determined by quantitative polymerase chain reaction. RESULTS: While 250 µg/ml EGCG significantly decreased the biomass and acid production of Sm biofilms, 500 µg/ml EGCG was required to inhibit Sm + LcY biofilm formation and acid production. EGCG decreased the amount of live bacteria present in both Sm and Sm + LcY biofilms. The level of dead bacteria in Sm + LcY biofilms was higher than in Sm biofilms when formed in the presence of 250 µg/ml EGCG. EGCG decreased levels of extracellular polysaccharides in Sm and Sm + LcY biofilms. The extent of biofilm removal by sonication was not different between Sm and Sm+LcY biofilms formed in the absence or presence of 62.5 or 125 µg/ml EGCG. The level of Sm gtfB and gtfD expression in Sm + LcY biofilms was higher than those in the Sm biofilms when formed in the presence of EGCG at 250 µg/ml. CONCLUSION: The results indicated that LcY might interfere the inhibitory effects of EGCG against biofilm formation by S. mutans.

Association between monocyte chemoattractant protein-1 -2518 A/G gene polymorphism and the outcome of the nonsurgical periodontal treatment.

BACKGROUND/PURPOSE: Elevated monocyte chemoattractant protein-1 (MCP-1) is related to severe periodontal destruction. Furthermore, MCP-1 -2518 A/G gene polymorphism affects MCP-1 after inflammatory stimuli. This study analyzed the association between MCP-1 -2518 gene polymorphism and the outcome of nonsurgical periodontal treatment. METHODS: Forty periodontal patients were recruited and MCP-1 -2518 A/G gene polymorphisms were analyzed using polymerase chain reaction-restriction fragment length polymorphism assay. The clinical periodontal parameters, including probing depth (PD), clinical attachment level (CAL), gingival index (GI), bleeding index (BI) and plaque index (PI), were recorded before and six weeks after nonsurgical periodontal therapy. Patients were divided into chronic periodontitis (CP) or aggressive periodontitis (AP). Multiple linear regression analysis was performed to investigate certain predictors of the therapy outcome. RESULTS: The frequency of MCP-1 -2518 genotype-positive (carrying allele G) was 42.5%. Poor treatment outcome in PD, GI and BI improvement could be predicted with MCP-1 -2518 A/G genotype and aggressive periodontitis status as the predictor variables. In contrast, MCP-1 -2518 A/A genotype and aggressive periodontitis status could predict better treatment response in PD and BI improvement. However, MCP-1 -2518 genotype did not affect the treatment outcome in patients with chronic periodontitis. CONCLUSION: MCP-1 -2518 A/G genotype might be useful in predicting less favorable nonsurgical treatment outcome in patients with aggressive periodontitis. However, MCP-1 -2518 gene polymorphism may not play a role in patients with chronic periodontitis. This study suggests that MCP-1 -2518 genotype may influence the outcome of nonsurgical periodontal treatment in aggressive periodontitis patients.

Levels of high-mobility group box-1 in gingival crevicular fluid in nonsmokers and smokers with chronic periodontitis.

BACKGROUND/PURPOSE: High-mobility group box-1 (HMGB1), a proinflammatory cytokine, plays a role in inflammatory disorders. Smoking is a well-established risk factor for periodontal disease. The aim of this study was to compare the levels of HMGB1 in the gingival crevicular fluid from periodontally healthy nonsmokers, chronic periodontitis nonsmokers, and chronic periodontitis smokers. Furthermore, the relationship between levels of HMGB1 and periodontal parameters was examined. METHODS: Periodontal parameters of 17 nonsmokers with chronic periodontitis, nine smokers with chronic periodontitis, and nine periodontally healthy nonsmokers were examined. Gingival crevicular fluid samples were collected, and the levels of HMGB1 were analyzed using the enzyme-linked immunosorbent assay. RESULTS: The median level of HMGB1 was statistically significantly higher in chronic periodontitis nonsmokers (37.5 ng/mL) than in chronic periodontitis smokers (9.5 ng/mL) and periodontally healthy nonsmokers (3.7 ng/mL). There was no significant difference in the levels of HMGB1 between chronic periodontitis smokers and periodontally healthy nonsmokers. Levels of HMGB1 were positively correlated with plaque index, gingival index, probing depth, and clinical attachment level of nonsmokers. However, no significant correlations were found between levels of HMGB1 and all periodontal parameters examined in chronic periodontitis smokers. CONCLUSION: Chronic periodontitis nonsmokers had elevated levels of HMGB1 in gingival crevicular fluid. Moreover, the levels of HMGB1 were correlated with severity of periodontitis. Chronic periodontitis smokers exhibited lower levels of HMGB1 than chronic periodontitis nonsmokers. Further research is needed for understanding the role of HMGB1 in smoking and pathogenesis of periodontitis.

Smartphone-based ecological momentary assessment for Chinese patients with depression: An exploratory study in Taiwan.

Mobile mental health has a potential to improve the recognition and management of Chinese patients with depression. Currently, evidence regarding ecological momentary assessment (EMA) for depressive disorder mostly originates from Western studies. Herein, we examined the validity of smartphone-based EMA for depression in Chinese patients and explored the determinants of use. A smartphone application, iHOPE, was used to perform daily EMA of depression, anxiety, sleep and cognitive performance. Outpatients with depressive disorder were recruited to use iHOPE for 8 weeks. Clinical characteristics and smartphone use patterns were assessed at baseline. We enrolled 59 Chinese patients with depression. In 8 weeks, participants interacted with iHOPE for an average of 10.8 (SD=12.3) days; a trend of decreased frequency of use (p=0.03) was observed. Scores of HAM-D at baseline was associated with, of the first 2 weeks, scores of PHQ-9 (p=0.005), EMA of depression (p=0.003) and anxiety (p<0.001), and poorer sleep quality (p=0.023). Among the demographic, clinical and smartphone-use variables examined, only limited internet package for smartphone (<500M per month) predicted higher use of iHOPE (p=0.04). The present study provides initial evidence for the feasibility of smartphone-based EMA in Chinese patients with depression. Level of engagement needs to be improved before determining its clinical usefulness.

Electrically adjustable location of a projected image in augmented reality via a liquid-crystal lens.

An augmented reality (AR) system involving the electrically tunable location of a projected image is implemented using a liquid-crystal (LC) lens. The projected image is either real or virtual. By effectively doubling the LC lens power following light reflection, the position of a projected virtual image can be made to vary from 42 to 360 cm, while the tunable range for a projected real image is from 27 to 52 cm on the opposite side. The optical principle of the AR system is introduced and could be further developed for other tunable focusing lenses, even those with a lower lens power. The benefits of this study could be extended to head-mounted display systems for vision correction or vision compensation. We believe that tunable focusing LC optical elements are promising developments in the thriving field of AR applications.

Electrically tunable microlens arrays based on polarization-independent optical phase of nano liquid crystal droplets dispersed in polymer matrix.

Electrically tunable focusing microlens arrays based on polarization independent optical phase of nano liquid crystal droplets dispersed in polymer matrix are demonstrated. Such an optical medium is optically isotropic which is so-called an optically isotropic liquid crystals (OILC). We not only discuss the optical theory of OILC, but also demonstrate polarization independent optical phase modulation based on the OILC. The experimental results and analytical discussion show that the optical phase of OILC microlens arrays results from mainly orientational birefringence which is much larger than the electric-field-induced birefringence (or Kerr effect). The response time of OILC microlens arrays is fast~5.3ms and the tunable focal length ranges from 3.4 mm to 3.8 mm. The potential applications are light field imaging systems, 3D integrating imaging systems and devices for augment reality.

Extended depth-of-focus 3D micro integral imaging display using a bifocal liquid crystal lens.

We present a three dimensional (3D) micro integral imaging display system with extended depth of focus by using a polarized bifocal liquid crystal lens. This lens and other optical components are combined as the relay optical element. The focal length of the relay optical element can be controlled to project an elemental image array in multiple positions with various lenslet image planes, by applying different voltages to the liquid crystal lens. The depth of focus of the proposed system can therefore be extended. The feasibility of our proposed system is experimentally demonstrated. In our experiments, the depth of focus of the display system is extended from 3.82 to 109.43 mm.

Bacterial adhesion to antibiotic-loaded guided tissue regeneration membranes - a scanning electron microscopy study.

BACKGROUND/PURPOSE: Bacterial contamination of sites undergoing guided tissue regeneration (GTR) therapy may reduce the efficiency of periodontal regeneration. This study compared bacterial adhesion onto various GTR membranes incorporated with antibiotics. METHODS: Three barrier membranes, including expanded polytetrafluoroethylene (ePTFE) membrane, collagen membrane, and glycolide fiber membrane, were loaded with tetracycline or amoxicillin. The adhesion of Streptococcus mutans and Aggregatibacter actinomycetemcomitans onto the GTR membranes with or without antibiotics was analyzed using the scanning electron microscopy (SEM) analysis. RESULTS: The SEM analysis showed no apparent alteration in the physical structure of the membranes loaded with antibiotics. Both S. mutans and A. actinomycetemcomitans attached best on the collagen membranes, followed by the ePTFE membranes, and then the glycolide fiber membranes without antibiotics. Moreover, higher numbers of bacteria were observed on the fibril areas than on the laminar areas of the ePTFE membranes. The amounts of attached bacteria on the GTR membranes increased after longer incubation. Incorporation of tetracycline or amoxicillin greatly reduced the adhesion of S. mutans and A. actinomycetemcomitans onto all of the GTR membranes examined. CONCLUSION: Incorporation of tetracycline or amoxicillin greatly reduced adhesion of S. mutans or A. actinomycetemcomitans on the ePTFE, glycolide fiber, or collagen membranes. This finding indicates that it is valuable and effective to use the antibiotic-loaded GTR membranes for periodontal regeneration therapy.

Porphyromonas gingivalis GroEL induces osteoclastogenesis of periodontal ligament cells and enhances alveolar bone resorption in rats.

Porphyromonas gingivalis is a major periodontal pathogen that contains a variety of virulence factors. The antibody titer to P. gingivalis GroEL, a homologue of HSP60, is significantly higher in periodontitis patients than in healthy control subjects, suggesting that P. gingivalis GroEL is a potential stimulator of periodontal disease. However, the specific role of GroEL in periodontal disease remains unclear. Here, we investigated the effect of P. gingivalis GroEL on human periodontal ligament (PDL) cells in vitro, as well as its effect on alveolar bone resorption in rats in vivo. First, we found that stimulation of PDL cells with recombinant GroEL increased the secretion of the bone resorption-associated cytokines interleukin (IL)-6 and IL-8, potentially via NF-κB activation. Furthermore, GroEL could effectively stimulate PDL cell migration, possibly through activation of integrin α1 and α2 mRNA expression as well as cytoskeletal reorganization. Additionally, GroEL may be involved in osteoclastogenesis via receptor activator of nuclear factor κ-B ligand (RANKL) activation and alkaline phosphatase (ALP) mRNA inhibition in PDL cells. Finally, we inoculated GroEL into rat gingiva, and the results of microcomputed tomography (micro-CT) and histomorphometric assays indicated that the administration of GroEL significantly increased inflammation and bone loss. In conclusion, P. gingivalis GroEL may act as a potent virulence factor, contributing to osteoclastogenesis of PDL cells and resulting in periodontal disease with alveolar bone resorption.

A large bistable negative lens by integrating a polarization switch with a passively anisotropic focusing element.

A bistable negative lens with a large aperture size (~10mm) by integrating a polarization switch of ferroelectric liquid crystals (FLCs) with a passively anisotropic focusing element is demonstrated. The proposed lens not only exhibits electrically tunable bistability but also fast response time of sub-milliseconds. The tunable lens power is from 0 to -1.74 Diopters. The electro-optical properties and imaging performances are demonstrated. The impact of this study is to provide a solution of electrically bistable liquid crystal lenses for the applications of portable devices, wearable devices and colored ophthalmic lenses.