ZccE, a P-type ATPase contributing to biofilm formation and competitiveness in Streptococcus mutans.

Most living organisms require zinc for survival; however, excessive amounts of this trace element can be toxic. Therefore, the frequent fluctuations of salivary zinc, caused by the low physiological level and the frequent introduction of exogenous zinc ions, present a serious challenge for bacteria colonizing the oral cavity. Streptococcus mutans is considered one of the main bacterial pathobiont in dental caries. Here, we verified the role of a P-type ATPase ZccE as the main zinc-exporting transporter in S. mutans and delineated the effects of zinc toxification caused by zccE deletion in the physiology of this bacterium. The deletion of the gene zccE severely impaired the ability of S. mutans to grow under high zinc stress conditions. Intracellular metal quantification using inductively coupled plasma optical emission spectrometer revealed that the zccE mutant exhibited approximately two times higher zinc accumulation than the wild type when grown in the presence of a subinhibitory zinc concentration. Biofilm formation analysis revealed less single-strain biofilm formation and competitive weakness in the dual-species biofilm formed with Streptococcus sanguinis for zccE mutant under high zinc stress. The quantitive reverse transcription polymerase chain reaction test revealed decreased expressions of gtfB, gtfC, and nlmC in the mutant strain under excessive zinc treatment. Collectively, these findings suggest that ZccE plays an important role in the zinc detoxification of S. mutans and that zinc is a growth-limiting factor for S. mutans within the dental biofilm.

Risk factors associated with early childhood caries among Wenzhou preschool children in China: a prospective, observational cohort study.

OBJECTIVES: Early childhood caries (ECC) is a serious health public problem that affects a large proportion of children in China. This study aimed to assess risk factors for the incidence of ECC among Wenzhou (China) preschoolers. DESIGN: Prospective, observational cohort study. SETTING: Kindergartens (n=6) in Wenzhou, China. PARTICIPANTS: 606 children who were 3-4 years of age and newly arrived in the kindergartens in September 2011. METHODS: This was a longitudinal observational study with a 2-year follow-up of preschoolers of 3-4 years of age in Wenzhou (Southeast China). Oral health data were collected annually after the baseline survey. The risk factors associated with visible caries and increment of decayed, missing and filled teeth (dmft) were analysed through univariable and multivariable regression using generalised estimating equations. RESULTS: The prevalence of ECC was increasing during the follow-up period (59.8% at enrolment, 71.8% at first year, and 76.4% at second year). Older age (b=0.07; 95% CI: 0.05 to 0.09; p<0.001), caregivers (relatives or nannies) (b=-1.20; 95% CI: -2.23 to -0.16; p=0.023), lower annual family income (¥10 000-¥20 000: b=2.04; 95% CI: 1.04 to 3.04; p<0.001; <¥10 000: b=1.78; 95% CI: 0.65 to 2.92; p=0.002) and more frequent consumption of sugary snacks/drinks at night (sometimes: b=0.88; 95% CI: 0.20 to 1.56; p=0.011; always: b=1.19; 95% CI: 0.13 to 2.25; p=0.028) were independently associated with the increments of dmft. Older age (OR=1.04, 95% CI: 1.03 to 1.05, p<0.001) and more frequent consumption of sweet snacks (OR=1.86, 95% CI: 1.06 to 3.27; p=0.030) were independently associated with a higher risk of visible caries. CONCLUSIONS: The occurrence and severity of ECC were associated with older age, caregivers (relatives or nannies), lower annual family income and more frequent consumption of sweet snacks. It is imperative to strengthen oral health education for parents and limit sugary foods/snacks.

Kill-Resist-Renew Trinity: Hyperbranched Polymer with Self-Regenerating Attack and Defense for Antifouling Coatings.

Traditional antifouling coatings are generally based on a single antifouling mechanism, which can hardly meet the needs of different occasions. Here, a single "kill-resist-renew trinity" polymeric coating integrating fouling killing, resistance, and releasing functions is reported. To achieve the design, a novel monomer-tertiary carboxybetaine ester acrylate with the antifouling group N-(2,4,6-trichlorophenyl)maleimide (TCB-TCPM) is synthesized and copolymerized with methacrylic anhydride via reversible addition-fragmentation chain transfer polymerization yielding a degradable hyperbranched polymer. Such a polymer at the surface/seawater is able to hydrolyze and degrade to short segments forming a dynamic surface (releasing). The hydrolysis of TCB-TCPM generates the antifouling groups TCPM (killing) and zwitterionic groups (resistance). Such a polymeric coating exhibits a controllable degradation rate, which increases with the degrees of branching. The antibacterial assay demonstrates that the antifouling ability arise from the synergistic effect of "attacking" and "defending". This study provides a new strategy to solve the challenging problem of marine biofouling.

Surface-fragmenting hyperbranched copolymers with hydrolysis-generating zwitterions for antifouling coatings.

Zwitterionic polymers have attracted increasing attention due to their excellent fouling resistance ability and eco-friendliness. Yet, their non-degradability and hydrophilic nature limit their applications. In this study, we have prepared a novel surface-fragmenting hyperbranched copolymer with tertiary carboxybetaine ester (TCB) primary chains and poly(ε-caprolactone) (PCL) bridged chains, where the former and the latter can hydrolyze and degrade in marine environments, continuously generating zwitterions, so the polymer coating has a fouling resistant and renewable surface. Our study demonstrates that the degradation rate of the polymer is well controlled by the content of PCL bridges. Protein resistance and antibacterial assays show that the coating can inhibit the adhesion of protein and marine bacteria (Pseudomonas sp.). This new surface-fragmenting, self-regenerating hyperbranched zwitterionic copolymer has multiple applications in antifouling coatings.

A longitudinal study of early childhood caries incidence in Wenzhou preschool children.

BACKGROUND: Early childhood caries (ECC) is a serious public health problem in China. Few studies, however, have described the incidence of ECC in China. The purpose of this study was to assess the prevalence and incidence of ECC among preschool children in Wenzhou China. METHODS: Preschool children aged 3-4 years old were surveyed and followed up when they reached 5-6 years of age in the city of Wenzhou in southeast China. The rates of dental caries were determined with prevalence, and incidence density for risk of caries of a person (IDp) and of a tooth surface (IDs). RESULTS: The prevalence and decayed, missing, and filled primary teeth (dmft) score of 3-4, 4-5, and 5-6 years old children were 59.8% and 2.9, 71.8% and 4.2, and 76.4% and 4.6, respectively. The IDp was 29.7 and 14.8 persons/100 person-year during the first and second year. The IDs was 5.9 and 2.7 newly affected surfaces/100 surface-year, respectively. The percentage of molars with caries experience increased obviously; the percentage of maxillary central incisors and mandibular incisors with caries experience increased during the first follow-up, whereas it declined during the second follow-up; the others increased gradually. CONCLUSIONS: The prevalence and incidence of dental caries in Wenzhou preschool children were very high with most of the carious teeth left untreated. The molars were the most affected teeth during the observation period.

Clinical and Radiographic Outcomes in Immature Permanent Necrotic Evaginated Teeth Treated with Regenerative Endodontic Procedures.

INTRODUCTION: Regenerative endodontics is a promising alternative treatment for immature permanent teeth with necrotic dental pulp. The present study assessed the time to resolution of clinical symptoms and radiographic changes in root dimensions in immature permanent necrotic teeth with dens evaginatus. METHODS: In this prospective study, clinical and radiographic data were collected for 20 teeth with dens evaginatus treated with a revascularization protocol for 1 year. Tooth survival and success rate were analyzed, and radiographic changes in the radiographic root area, apical diameter, and root length were quantified. RESULTS: All 20 treated teeth (100%) survived and met the clinical criteria for success throughout the study period. The within-case percent change in radiographic root area was 28.14% at 3 months and had increased to 97.58% at 12 months. The within-case percent change in apical diameter after 3 months was 21.40% and had increased to 72.90% by 12 months, with 40% (8 of 20) showing complete apical closure at 12 months. The within-case percent change in root length was 2.65% at 3 months and had increased to 23.37% at 12 months. CONCLUSIONS: In this study, revascularization allowed the continued development of roots in teeth with necrotic pulp as well as excellent overall survival and success rates.

Loss of TRADD attenuates pressure overload-induced cardiac hypertrophy through regulating TAK1/P38 MAPK signalling in mice.

We investigated the role of tumour necrosis factor receptor (TNFR)-associated death domain (TRADD) on pressure overload-induced cardiac hypertrophy and the underlying molecular mechanisms by using a TRADD deficiency mice model. 6-8 weeks wild-type and TRADD knockout mice were performed to transverse aorta constriction (TAC) or sham operation (6-8 mice for each group). 14 days after TAC, cardiac function was measured by echocardiography, as well as by pathological and molecular analyses of heart samples. The expressions of cardiac hypertrophic and fibrotic markers were detected by qPCR. Phosphorylated and total TAK1, Akt, and p38 MAPK levels were examined by Western blotting. The ratios of lung or heart/body weight, wall thickness/chamber diameter of left ventricular and cross area of cardiomyocyte were significantly reduced in TRADD knockout (KO) mice than those of wild-type mice after TAC. Moreover, cardiac hypertrophic and fibrotic markers were downregulated in TRADD knockout mice than those of wild-type mice following TAC. Protein expression analysis showed phosphorylated TAK1, p38 MAPK and AKT were upregulated after TAC in both wild-type and TRADD KO mice, phosphorylation of TAK1 and p38 MAPK was reduced more remarkably after TRADD deficiency, while phosphorylated AKT expression was similar between TRADD KO and wild-type mice following TAC. Our data suggest that TRADD KO blunts pressure overload-induced cardiac hypertrophy through mediating TAK1/p38 MAPK but not AKT phosphorylation in mice.

MD2 mediates angiotensin II-induced cardiac inflammation and remodeling via directly binding to Ang II and activating TLR4/NF-κB signaling pathway.

Angiotensin II (Ang II) induces cardiac inflammation and remodeling. Emerging evidence indicates that Ang II may utilize the Toll-like receptor 4 (TLR4) signaling pathway in mediating pro-inflammatory and pro-fibrotic activities. However, the precise mechanism is poorly understood. Myeloid differentiation 2 (MD2), a molecule that physically binds to TLR4, confers lipopolysaccharide responsiveness and may also be involved in mediating the actions of Ang II. We hypothesize that MD2 plays an essential role in cardiac inflammation and remodeling induced by local Ang II, and inhibition of MD2 can attenuate Ang II-induced cardiac dysfunction. Using a specific small molecule MD2 blocker L6H21 and the MD2 knockout mice, we show that MD2 deficiency significantly reduces cardiac inflammation and subsequent fibrosis, hypertrophy, and dysfunction in mice challenged with subcutaneous injection of Ang II. In rat cardiomyocyte-like H9c2 cells as well as rat primary cardiomyocytes, inhibition of MD2 by L6H21 or siRNA knockdown suppressed the Ang II-induced TLR4 signaling pathway activation including MyD88 recruitment, and reduced cardiomyocyte hypertrophy and matrix protein expression. These pro-inflammatory activities of Ang II were independent of the AT1 receptor. Finally, we demonstrated the direct interaction between Ang II and MD2 protein via hydrogen bonds on Arg-90, Glu-92, and Asp-100. Ang II produces an inflammatory response and cardiac remodeling by directly binding to MD2, activating MD2/TLR4 complex, and recruiting MyD88. MD2 may be a new therapeutic target for Ang II-mediated cardiac inflammation and remodeling.

Targeting myeloid differentiation protein 2 by the new chalcone L2H21 protects LPS-induced acute lung injury.

Acute inflammatory diseases are the leading causes of mortality in intensive care units. Myeloid differentiation 2 (MD-2) is required for recognizing lipopolysaccharide (LPS) by toll-like receptor 4 (TLR4), and represents an attractive therapeutic target for LPS-induced inflammatory diseases. In this study, we report a chalcone derivative, L2H21, as a new MD2 inhibitor, which could inhibit LPS-induced inflammation both in vitro and in vivo. We identify that L2H21 as a direct inhibitor of MD-2 by binding to Arg90 and Tyr102 residues in MD-2 hydrophobic pocket using a series of biochemical experiments, including surface plasmon response, molecular docking and amino acid mutation. L2H21 dose dependently inhibited LPS-induced inflammatory cytokine expression in primary macrophages. In mice with LPS intratracheal instillation, L2H21 significantly decreased LPS-induced pulmonary oedema, pathological changes in lung tissue, protein concentration increase in bronchoalveolar lavage fluid, inflammatory cells infiltration and inflammatory gene expression, accompanied with the decrease in pulmonary TLR4/MD-2 complex. Meanwhile, administration with L2H21 protects mice from LPS-induced mortality at a degree of 100%. Taken together, this study identifies a new MD2 inhibitor L2H21 as a promising candidate for the treatment of acute lung injury (ALI) and sepsis, and validates that inhibition of MD-2 is a potential therapeutic strategy for ALI.

Effect of application time of maleic acid on smear layer removal and mechanical properties of root canal dentin.

OBJECTIVES: To evaluate the effect of maleic acid (MA) on the cleaning efficacy and mechanical properties of root canal dentine with respect to different time exposure. MATERIALS AND METHODS: One hundred and eighty single-canal premolars were instrumented with rotary-files and then randomly assigned to test groups receiving 7% MA for 30 s, 45 s, 1 min, or 3 min or to control groups treated with 0.9% saline or 17% ethylenediaminetetraacetic acid for 45 s. The micro-hardness, nano-hardness and elastic modules were measured before and after treatment, while the amount of smear and erosion in the coronal, middle and apical thirds in root canal were evaluated by scanning electron microscopy, finally, the fracture strength was assessed by vertical root fracture testing. RESULTS: The efficacy of smear layer removal increased with increasing MA application time. The largest effect was observed at 45 s, even in the apical third, whereas the treatment for 1 min resulted in irreversible erosion of the dentine surface. The micro-hardness and nano-indentation testing confirmed that the micro- and nano-scale mechanical properties were significantly decreased after MA application for 1 min. Furthermore, the specimens treated with MA for 3 min presented the lowest fracture resistance among all groups. In contrast, the 45 s treatment appeared to increase the fracture resistance of the tooth. CONCLUSIONS: The cleaning efficacy and mechanical properties of root canal dentine varied with MA exposure time. The application of MA for 45 s was found to be the most promising for clinical use.

Olmesartan ameliorates pressure overload-induced cardiac remodeling through inhibition of TAK1/p38 signaling in mice.

AIMS: Many studies have demonstrated the potent effects of ARB administration on heart failure. However, the mechanism of the potent effects of ARB on cardiac remodeling is less well understood. We investigated the role of Olmesartan on the fibrosis and hypertrophy in mouse heart. MATERIALS AND METHODS: We employed TAC surgery, a mouse model of chronic cardiac failure. All the mice were separated into three groups: the sham group, TAC group and TAC plus Olmesartan group (given Olmesartan treatment after TAC). We analyzed left ventricle remodeling, and function by echocardiography or pathology. We further detected the level of marker genes involved in fibrosis and hypertrophy and in cultured neonatal rat cardiac fibroblasts and myocytes infected by constitutively active TAK1 and p38MAPK. After TAC, all the mice developed hypertrophy, worse cardiac function and malignant remodeling in left ventricle. KEY FINDINGS: Olmesartan improved heart remodeling and function without changing pressure of blood. Moreover, Olmesartan reduced the level of transforming growth factor ß activated kinase-1 (TAK1) and phospho-p38MAPK. In neonatal rat cardiac fibroblast cells and cardiomyocytes, Olmesartan also decreased TAK1 and p38MAPK activation triggered by TGFß1 or AngII. The inhibitory effect of Olmesartan was abrogated by overexpression of constitutively active TAK1 and p38MAPK by adenovirus system. SIGNIFICANCE: Our results suggest Olmesartan improves heart remodeling and function induced by pressure overload. P38MAPK inactivation attenuated by olmesartan via inhibition of TAK1 pathway plays an important role in the process.

Increased cardiac remodeling in cardiac-specific Flt-1 receptor knockout mice with pressure overload.

Vascular endothelial growth factor (VEGF) inhibition has previously been shown to have damaging effects on the heart. Because the role of Flt-1 (a phosphotyrosine kinase receptor for VEGF) in cardiac function and hypertrophy is unclear, we generated mice lacking Flt-1 only in their cardiomyocytes (Flt-1 KO). The hearts from 8- to 10-week-old mice were measured by using echocardiography and histology. No significant differences were seen in fraction shortening, cross-sectional area of cardiomyocytes, and interstitial collagen fraction between littermate controls and KO mice at baseline. To test the hypothesis that Flt-1 is involved in cardiac remodeling, we performed transverse aorta constriction (TAC) by ligating the transverse ascending aorta. Four weeks after TAC, echocardiography of the mice was performed, and the hearts were excised for pathological analysis and Western blotting. No difference in mortality was found between Flt-1 KO mice and controls; however, KO mice showed a greater cardiomyocyte cross-sectional area and interstitial collagen fraction than controls. Western blotting indicated that AKT was activated less in Flt-1 KO hearts after TAC compared with that in control hearts. Thus, Flt-1 deletion in cardiomyocytes increased hypertrophy, fibrosis, and regression of AKT phosphorylation. Our study suggests that Flt-1 plays a critical role in cardiac hypertrophy induced by pressure overload via the activation of AKT, which seems to be cardioprotective.

Preparation, characterization and evaluation of chitosan macroporous for potential application in skin tissue engineering.

In this paper, chitosan macroporous membrane was developed by a selective dissolution technology using silica particles (SiO(2)) as the porogen agent. Regarding of the weight ratio of silica particle/chitosan (1:2, 1:1 and 2:1; w/w), a series of chitosan membranes were developed. The initial SiO(2) content in the formulation was greatly influenced on the morphology of chitosan membrane. As the initial SiO(2)/chitosan weight ratio was lower than 1:2, the developed chitosan membrane was dense absence of any porous structure. Meanwhile, the developed chitosan membranes were characterized by scanning electron microscopy (SEM), porosity, mechanical property, water adsorption as well as in vitro degradation. In vitro cytotoxicity study showed that the extractions of all developed chitosan membranes were non-cytotoxic against L-929 cells after 24 h of culturing. L-929 cells cultured with chitosan macroporous membrane (S3) revealed that the cells were flattened with effective spreading after 24 h and 48 h of culturing. All these results indicated that the developed chitosan macroporous membrane might have potential application in skin tissue engineering.

[Analysis of the reliability and validity of the simplified Chinese version of the early childhood oral health impact scale].

PURPOSE: To evaluate the reliability and validity of the Chinese version of The Early Childhood Oral Health Impact Scale. METHODS: Using translation,back -translation, quality evaluation,cross-cultural adaptation and pre-assessment, a Chinese draft scale of the ECOHIS was obtained, then applied to two groups of children. One group was 200 pre-school children which were randomly selected from 2 kindergartens of Chengdu city; the other group was 100 patients aged 3-5 years old from the paediatric dentistry of West China College of Stomatology,Sichuan University. After their guardians accomplished the questionnaires, the collected data was analyzed to evaluate the reliability and validity of the scale. RESULTS: The Chinese version of the ECOHIS showed the following psychometric properties from 97.3% valid questionnaires. The Cronbach's alpha ,split-half reliability and correlation of the scale was 0.899,0.799 and 0.666,respectively. By factor analysis of construct validity,the 13 items were classified into 3 domains, the cumulative proportion was 63.87%.The scale had certain logical relation between the items in the same domain. Each item of the scale was sensitive to discriminate the Oral Health-Related Quality of Life (OHRQoL)between general population and patients(P<0.01). CONCLUSIONS: The Chinese version of ECOHIS had a good reliability and validity by rigorous psychometric properties.It can be widely used to test the OHRQoL of pre-school children.

Is ethanol consumption beneficial for oral lichen planus?

Oral lichen planus (OLP), one of the most common oral mucosa diseases, is an auto-immune disease characterized histologically by basal keratinocyte damage and interface lymphocyte reaction. Previous studies have proved ethanol consumption can suppress immune system in many aspects, including inhibiting lymphocytes proliferation and their function, modifying antigen-presentation, etc. Pathogenesis of the OLP mainly comprises of antigen-presentation, lymphocytes activation and keratinocyte apoptosis, all of which may be inhibited by ethanol consumption. Thus, we put forth our hypothesis that chronic ethanol consumption may decrease OLP incidence and OLP treatment except the erosive type may benefit from ethanol consumption. In the discussion, we also talk about the extent of ethanol consumption. Still ethanol abuse is not commended, for it may increase incidence of many other diseases, and moderate ethanol consumption may be potentially beneficial for other auto-immune diseases.