Nicotine inhibits osteogenic differentiation of human periodontal ligament cells under cyclic tensile stress through canonical Wnt pathway and α7 nicotinic acetylcholine receptor

BACKGROUND AND OBJECTIVES

Nicotine, the main psychoactive component of tobacco, affects cell metabolism, proliferation, adhesion and, importantly, the osteogenic differentiation of fibroblasts. Approximately 15% of all orthodontic patients are adults among who one-fifth are smokers. Hence, it is necessary to have insight into the effects of nicotine on the osteogenic differentiation of hPDLCs during orthodontic tooth movement. This study aimed to investigate the effects and mechanisms of nicotine on the osteogenic differentiation of human periodontal ligament cells (hPDLCs) under the application of cyclic tensile stress.

MATERIAL AND METHODS

hPDLCs were obtained from donor third molars. The hPDLCs were treated with nicotine and/or cyclic tensile stress that was applied with a cell stress plus unit. The effect of nicotine on cell viability was analyzed using the MTT assay. The osteogenic differentiation of hPDLCs was detected by alkaline phosphatase staining, Alizarin Red S staining, quantitative real-time polymerase chain reaction and western blotting.

RESULTS

In combination with cyclic tensile stress, nicotine prevented the tensile stress-induced increase in alkaline phosphatase activity, formation of mineralization nodules and the upregulation of mRNA and protein expression of Runt-related transcription factor 2, transcription factor Sp7 and collagen type I; however, canonical Wnt pathway was activated. Furthermore, the addition of Dickkopf-related protein 1 and α-bungarotoxin counteracted the negative effect of nicotine and rescued the osteogenic differentiation of hPDLCs, respectively.

CONCLUSION

These results indicate that nicotine prevents the increased osteogenic potential of hPDLCs induced by cyclic tensile stress by binding to an α7 nicotinic acetylcholine receptor and activating the canonical Wnt pathway.

Nanoscale beam splitters based on gradient metasurfaces

Beam splitters are essential components in various optical and photonic applications, for example, interferometers, multiplexers, and so on. Present beam splitters based on cubes or plates are normally bulky. Realizing beam splitters in nanoscales is useful to reduce the total size of photonic devices. We demonstrate here a beam splitter with nanoscale thickness based on a gradient metasurface comprising lithium niobate cylinder arrays. Since one unit cell of metasurface comprising two cylinder rows shows two opposite phase gradients, the incident light is split into different directions according to the generalized Snell's law. The split ratio is proven to be effectively tunable.

Influence of exercise intervention on gestational diabetes mellitus: a systematic review and meta-analysis

AIMS

Exercise intervention might be a promising approach to prevent gestational diabetes mellitus. However, the results remained controversial. We conducted a systematic review and meta-analysis to explore the effect of exercise intervention on gestational diabetes mellitus.

METHODS

PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases were systematically searched. Randomized controlled trials (RCTs) assessing the effect of exercise intervention on gestational diabetes mellitus were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. The primary outcome was the incidence of gestational diabetes mellitus, preterm birth, and gestational age at birth. Meta-analysis was performed using random-effect model.

RESULTS

Five RCTs involving 1872 patients were included in the meta-analysis. Overall, compared with control intervention, exercise intervention was found to significantly reduce the risk of gestational diabetes mellitus (std. mean difference 0.62; 95% CI 0.43-0.89; P = 0.01), but demonstrated no influence on preterm birth (OR 0.93; 95% CI 0.44-1.99; P = 0.86), gestational age at birth (std. mean difference -0.03; 95% CI -0.12 to 0.07; P = 0.60), glucose 2-h post-OGTT (std. mean difference -1.02; 95% CI -2.75 to 0.71; P = 0.25), birth weight (std. mean difference -0.10; 95% CI -0.25 to 0.04; P = 0.16), Apgar score less than 7 (OR 0.78; 95% CI 0.21-2.91; P = 0.71), and preeclampsia (OR 1.05; 95% CI 0.53-2.07; P = 0.88).

CONCLUSIONS

Compared to control intervention, exercise intervention was found to significantly reduce the incidence of gestational diabetes mellitus, but had no significant influence on preterm birth, gestational age at birth, glucose 2-h post-OGTT, birth weight, Apgar score less than 7, and preeclampsia.

Dynamic spontaneous emission control of an optical emitter coupled to plasmons in strained graphene

Spontaneous emission control of an optical emitter is critical for many applications, such as in the fields of sensing, integrated photonics and quantum optics. Integrating optical emitters with a mechanical system can provide an avenue for strain sensors as well. Here, the dynamic spontaneous emission modification of an emitter coupled to graphene by uniaxial strain is demonstrated. Our results show that the emission rate can be controlled by tuning the strain of graphene, which depends on the polarized orientation of the emitter. More specifically, the decay rate can be enhanced for several times if the emitter is polarized perpendicular to graphene under strain. Azimuthal angle dependent oscillation of decay rate exists for the emitter polarized parallel to the graphene. Moreover, the controllable decay of the emitter comes from the anisotropic plasmons excitation in strained graphene, which is verified by the corresponding isofrequency contours of plasmons. The strain engineering provides a new platform for dynamic spontaneous emission modulation of emitters coupled with graphene, which opens up intriguing possibilities for the design of strain sensors and quantum devices.

[Utility and evaluation of immunohistochemical detection of BRAF V600E mutation in melanoma]

Objective: To evaluate the sensitivity, specificity and clinical value of anti-BRAF V600E antibody (clone VE1) in detection of the BRAF V600E mutant in formalin-fixed and paraffin-embedded (FFPE) melanoma specimens by immunohistochemical (IHC) methods. Methods: A total of 50 melanoma samples collected between 2008 and 2016 from 40 patients were analyzed for BRAF mutation (exon 15) by DNA sequencing using FFPE. These tissues were immunostained with VE1 antibody, and the results were analyzed and compared with those by DNA sequencing. Results: By DNA sequencing, 36 cases showed BRAF mutation while others were BRAF wild type. Among the 36 cases with BRAF mutation, 32 harbored BRAF V600E, two harbored BRAF V600K, one had BRAF K601E and one had BRAF D594N, respectively. IHC staining showed 30 specimens were VE1 positive, while 19 were negative. The determination of IHC result for one case was obscured by heavy pigments. Of the BRAF-mutated specimens, four specimens with BRAF mutation other than V600E were all negative for VE1. The sensitivity and specificity of the VE1 immunostaining was 96.8% and 100.0% respectively.Concordance of BRAF V600E detection between immunostaining and DNA sequencing was 98.0%(48/49). Conclusions: High sensitivity and specificity for VE1 immunostaining in detecting BRAF V600E in melanomas are demonstrated. It is a rapid and cost-effective method for detecting BRAF V600E mutations in melanoma patients. Hence, VE1 immunostaining can be used as an important screening method for BRAF mutation in laboratories.

In-Plane Electrical Connectivity and Near-Field Concentration of Isolated Graphene Resonators Realized by Ion Beams

Graphene plasmons provide great opportunities in light-matter interactions benefiting from the extreme confinement and electrical tunability. Structured graphene cavities possess enhanced confinements in 3D and steerable plasmon resonances, potential in applications for sensing and emission control at the nanoscale. Besides graphene boundaries obtained by mask lithography, graphene defects engineered by ion beams have shown efficient plasmon reflections. In this paper, near-field responses of structured graphene achieved by ion beam direct-writing are investigated. Graphene nanoresonators are fabricated easily and precisely with a spatial resolution better than 30 nm. Breathing modes are observed in graphene disks. The amorphous carbons around weaken the response of edge modes in the resonators, but meanwhile render the isolated resonators in-plane electrical connections, where near-fields are proved gate-tunable. The realization of gate-tunable near-fields of graphene 2D resonators opens up tunable near-field couplings with matters. Moreover, graphene nonconcentric rings with engineered near-field confinement distributions are demonstrated, where the quadrupole plasmon modes are excited. Near-field mappings reveal concentrations at the scale of 3.8×10-4λ02 within certain zones which can be engineered. The realization of electrically tunable graphene nanoresonators by ion beam direct-writing is promising for active manipulation of emission and sensing at the nanoscale.

[Effects of overexpression of human tissue inhibitor of metalloproteinase-1 on the inflammatory response in rats with myocardial infarction and related mechanisms]

Objective: To observe the effects of recombinant adenovirus with human tissue inhibitor of metalloproteinase-1(Ad-hTIMP-1) on the inflammatory response in rats with myocardial infarction (MI) and explore the related mechanisms. Methods: The male Wistar rats were randomly divided into sham-operated group, saline group, Ad-Track group and Ad-hTIMP-1 group according to the random number table (n=8 each group). MI was induced by ligation of the left anterior descending coronary artery and MI rats were injected with saline, Ad-Track and Ad-hTIMP-1, respectively. Sham-operated rats received similar surgical procedure without ligation of the left anterior descending coronary artery. After 4 weeks, the cardiac function was measured by echocardiography, then rats were sacrificed and hearts were removed for morphological and biological analysis. The morphology of myocardial tissue in each group was detected by HE staining and Masson staining. The mRNA expressions of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-10 and C-reactive protein(CRP) were detected by real-time PCR. Immune histochemical staining was performed to observe the protein expression levels of IL-6 and CRP. Results: (1) Left ventricular end systolic dimension derived from echocardiography was increased in saline group ((5.10±0.72) mm) and Ad-Track group ((4.88±0.64) mm) compared to sham-operated group ((4.25±0.46) mm), which was reduced in Ad-hTIMP-1 group ((4.13±0.35) mm, all P<0.05). The left ventricular ejection fraction was (72.46±5.74)%, (64.27±8.52)%, (64.65±3.90)%, and (71.55±6.95)%, the fractional shortening was (36.90±4.97)%, (29.03±3.40)%, (30.95±2.51)%, and (36.31±5.68)% in sham-operated group, saline group, Ad-Track group and Ad-hTIMP-1 group, respectively. The left ventricular ejection fraction and fractional shortening in saline group and Ad-Track group were lower than those in sham-operated group and Ad-hTIMP-1 group (all P<0.05). (2) Necrosis of myocardial cells was not found and a small amount of immune cell infiltration and interstitial fibrosis were observed on HE and Masson stained myocardial sections of Ad-hTIMP-1 group. (3) Real-time PCR showed that mRNA expressions of TNF-α, IL-6, IL-10 and CRP were lower in Ad-hTIMP-1 group than in saline group. mRNA expressions of TNF-α, IL-10 and CRP were lower in Ad-hTIMP-1 group than in Ad-Track group (all P<0.05). (4) Immune histochemical staining showed that protein expressions of IL-6 and CRP were higher in saline group and Ad-Track group than those in Ad-hTIMP-1 group (all P<0.05). Conclusion: Recombinant adenovirus Ad-hTIMP-1 can improve cardiac function in rats with myocardial infarction via inhibiting the inflammatory response and downregulating the expression of TNF-α, IL-6 and CRP.

Characterization and development of 56 EST-SSR markers derived from the transcriptome of Odontobutis potamophila

Expressed sequence tags (ETSs) are the sources of microsatellite development. In this study, we isolated and characterized microsatellite markers for Odontobutis potamophila by using Illumina RNA-sequencing. We sequenced a large number of ESTs and screened 200 potential microsatellites. Consequently, a total of 56 novel polymorphic microsatellite repeat markers were identified in thirty-two individuals from a wild population area (Jiande, Zhejiang Province, China). The number of alleles per locus varied from two to eight, the observed heterozygosity (H_O) ranged from 0.03571 to 0.9375, and the expected heterozygosity (H_E) ranged from 0.14326 to 0.81549. The average number of alleles, H_O, and H_E were 5.0, 0.4467, and 0.5518, respectively. By the calculation, the range of polymorphism information content (PIC) was 0.1177-0.8492. Most of the loci showed moderate or high polymorphism. These newly developed EST-simple sequence repeat (EST-SSR) markers would serve as an efficient tool for analyzing population connectivity and provide sufficient information for genetic diversity research, parentage, and molecular breeding of O. potamophila and other fishes with similar genetic relationship.

Unveiling quasi-dark surface plasmon modes in Au nanoring cavities by cathodoluminescence

Spectral resolving and imaging surface plasmon modes in noble metal nanostructures are important for applications in nanophotonics. Here, we use cathodoluminescence (CL) spectroscopy to excite and probe quasi-dark plasmon modes of Au nanoring cavities. Numerical simulations of both the spectra and the electromagnetic field distribution are carried out by using boundary element method. Good agreement between the experimental and simulated results is obtained. Particularly, CL is shown as an efficient method to probe quadrupole modes, which is difficult for traditional optical means. Moreover, a high Purcell factor in excess of 100 is obtained for the dark quadrupole modes in gold ring cavities. Our work provides an efficient way to explore the initial nature of surface plasmon modes in metal nanostructures.

An autonomous lab on a chip for space flight calibration of gravity-induced transcellular calcium polarization in single-cell fern spores

This report describes the development of lab-on-a-chip device designed to measure changes in cellular ion gradients that are induced by changes in gravitational (g) forces. The bioCD presented here detects differential calcium ion concentrations outside of individual cells. The device includes sufficient replicates for statistical analysis of the gradients around multiple single cells and around control wells that are empty or include dead cells. In the data presented, the degree of the cellular response correlates with the magnitude of the g-force applied via rotation of the bioCD. The experiments recorded the longest continuous observation of a cellular response to hypergravity made to date, and they demonstrate the potential utility of this device for assaying the threshold of cells' g-force responses in spaceflight conditions.

Unidirectional excitation of graphene plasmons in Au-graphene composite structures by a linearly polarized light beam

Controllable manipulation of propagating surface plasmon polaritons is critical in plasmonics and important for nanophotonic applications. Here, we demonstrate theoretically that graphene plasmons (GPs) can be unidirectionally excited in an Au-graphene composite structure by a linearly polarized optical wave at the wavelength of 10.2 µm. The unidirectional ratio can reach as large as 900 with the incidence angle at 37.7° off normal, which is obtained by the angular spectrum of GPs. Moreover, the physical mechanism behind the unidirectional excitation is revealed to be the interference between anti-symmetric and symmetric amplitude distributions of GPs, which are induced by the gold rod antenna under the normal and grazing illuminations, respectively.

Shock-transformation of whitlockite to merrillite and the implications for meteoritic phosphate

Meteorites represent the only samples available for study on Earth of a number of planetary bodies. The minerals within meteorites therefore hold the key to addressing numerous questions about our solar system. Of particular interest is the Ca-phosphate mineral merrillite, the anhydrous end-member of the merrillite–whitlockite solid solution series. For example, the anhydrous nature of merrillite in Martian meteorites has been interpreted as evidence of water-limited late-stage Martian melts. However, recent research on apatite in the same meteorites suggests higher water content in melts. One complication of using meteorites rather than direct samples is the shock compression all meteorites have experienced, which can alter meteorite mineralogy. Here we show whitlockite transformation into merrillite by shock-compression levels relevant to meteorites, including Martian meteorites. The results open the possibility that at least part of meteoritic merrillite may have originally been H⁺-bearing whitlockite with implications for interpreting meteorites and the need for future sample return.

Quantifying the amount of water in meteorites remains challenging, with minerals the key to understanding water contents. Here, Adcock et al. perform shock experiments on H⁺-bearing whitlockite demonstrating that it may transform into anhydrous merrillite, which is commonly found in Martian meteorites.

Dielectric-Like Behavior of Graphene in Au Plasmon Resonator

Graphene has proven to be a promising conductive layer in fabricating optical plasmon resonators on insulator substrate using electron beam lithography and has the potential to construct electrically controlled active plasmon resonators. In this study, we investigate the effect of graphene on plasmon resonance using graphene and Au plasmon resonator system as a model at visible and near-infrared wavelength. Our experiment data show that the presence of graphene does not weaken and annihilate the plasmon resonance peaks, instead it predominantly makes the peaks redshift, which is similar to the behavior of depositing SiO₂ film on Au plasmon resonators. This fact indicates that graphene predominantly exhibits dielectric-like behavior at visible and near-infrared wavelength, which can be attributed to the low carrier density in graphene compared with metals.

Ex vivo expansion of antigen-specific CD4+CD25+ regulatory T cells from autologous naïve CD4+ T cells of multiple sclerosis patients as a potential therapeutic approach

OBJECTIVE

CD4+CD25+ regulatory T cells (Tregs) have been found to have a decreased effector function in patients with multiple sclerosis (MS). In this study, we co-cultured naïve CD4+ T cells of MS patients with myelin basic protein (MBP)85-99 peptide as specific antigen and allogenic B cells as antigen-presenting cells, in an attempt to generate adequate antigen-specific CD4+CD25+ Tregs with normal or improved immune function.

PATIENTS AND METHODS

Naïve CD4+ T cells were isolated from peripheral blood mononuclear cells (PBMCs) from patients with MS (n=5) and healthy controls (HC, n=5). Furthermore, these purified naive CD4+ T cells were co-cultured with the CD40-activated B cells and MBP85-99 peptide to induce MBP-reactive CD4+CD25highCD127low Tregs. After harvesting these Tregs via a flow sorter, real-time PCR and mixed lymphocyte reaction (MLR) assay were performed to characterize cellular immune function. Supernatant interleukin (IL)-10 and transforming growth factor (TGF)-β1 protein levels were detected by an enzyme-linked immunosorbent assay (ELISA).

RESULTS

With this method, the frequency of CD4+CD25highCD127low Tregs in CD4+ T cells was 3.5%-6%. In both MS and HC groups, there were relatively lower proliferation indices (PI) of MLR assay but higher supernatant IL-10 and TGF-β1 levels in the presence of MBP than those in the presence of other control antigens, where no significant differences were found.

CONCLUSIONS

Via the ex vivo culture, adequate MBP-reactive CD4+CD25+ Tregsderived from autologous naïve CD4+ T cells of MS patients, were obtained and returned to normal without immune defects, and even upregulated their immunosuppressive function mostly through the elevated release of IL-10 and TGF-β1.

Flexible modulation of plasmon-induced transparency in a strongly coupled graphene grating-sheet system

General actively tunable near-field plasmon-induced transparency (PIT) systems based on couplings between localized plasmon resonances of graphene nanostructures not only suffer from interantenna separations of smaller than 20 nm, but also lack switchable effect about the transparency window. Here, the performance of an active PIT system based on graphene grating-sheet with near-field coupling distance of more than 100 nm is investigated in mid-infrared. The transparency window in spectrum is analyzed objectively and proved to be more likely stemmed from Aulter-Townes splitting. The proposed system exhibits flexible tunability in slow-light and electro-optical switches, promising for practical active photonic devices.

Branched-chain Amino Acids are Beneficial to Maintain Growth Performance and Intestinal Immune-related Function in Weaned Piglets Fed Protein Restricted Diet

As a novel approach for disease control and prevention, nutritional modulation of the intestinal health has been proved. However, It is still unknown whether branched-chain amino acid (BCAA) is needed to maintain intestinal immune-related function. The objective of this study was to determine whether BCAA supplementation in protein restricted diet affects growth performance, intestinal barrier function and modulates post-weaning gut disorders. One hundred and eight weaned piglets (7.96±0.26 kg) were randomly fed one of the three diets including a control diet (21% crude protein [CP], CON), a protein restricted diet (17% CP, PR) and a BCAA diet (BCAA supplementation in the PR diet) for 14 d. The growth performance, plasma amino acid concentrations, small intestinal morphology and intestinal immunoglobulins were tested. First, average daily gain (ADG) (p<0.05) and average daily feed intake (ADFI) (p<0.05) of weaned pigs in PR group were lower, while gain:feed ratio was lower than the CON group (p<0.05). Compared with PR group, BCAA group improved ADG (p<0.05), ADFI (p<0.05) and feed:gain ratio (p<0.05) of piglets. The growth performance data between CON and BCAA groups was not different (p>0.05). The PR and BCAA treatments had a higher (p<0.05) plasma concentration of methionine and threonine than the CON treatment. The level of some essential and functional amino acids (such as arginine, phenylalanine, histidine, glutamine etc.) in plasma of the PR group was lower (p<0.05) than that of the CON group. Compared with CON group, BCAA supplementation significantly increased BCAA concentrations (p<0.01) and decreased urea concentration (p<0.01) in pig plasma indicating that the efficiency of dietary nitrogen utilization was increased. Compared with CON group, the small intestine of piglets fed PR diet showed villous atrophy, increasing of intra-epithelial lymphocytes (IELs) number (p<0.05) and declining of the immunoglobulin concentration, including jejunal immunoglobulin A (IgA) (p = 0.04), secreted IgA (sIgA) (p = 0.03) and immunoglobulin M (p = 0.08), and ileal IgA (p = 0.01) and immunoglobulin G (p = 0.08). The BCAA supplementation increased villous height in the duodenum (p<0.01), reversed the trend of an increasing IELs number. Notably, BCAA supplementation increased levels of jejunal and ileal immunoglobulin mentioned above. In conclusion, BCAA supplementation to protein restricted diet improved intestinal immune defense function by protecting villous morphology and by increasing levels of intestinal immunoglobulins in weaned piglets. Our finding has the important implication that BCAA may be used to reduce the negative effects of a protein restricted diet on growth performance and intestinal immunity in weaned piglets.

Inflammatory dentigerous cyst of mandibular first premolar associated with endodontically treated primary first molar: a rare case report

AIM

Inflammatory dentigerous cysts usually occur in the mixed dentition. It has been reported that inflammatory lesions from the root area of a deciduous tooth bring about the development of dentigerous cysts around the unerupted permanent tooth bud. Endodontic treatment is a common and successful procedure for periapical inflammation in children. An inflammatory dentigerous cyst can occur in conjunction with endodontically treated primary tooth.

CASE REPORT

This article reports a case of 6 years and 6 months old boy, with a single, well-defined, unilocular, radiolucent area enclosing the first right unerupted mandibular premolar, accidentally discovered on the panoramic radiograph. The first right primary molar had received a root canal treatment 18 months prior. Clinical findings combined with radiographic and microscopic examinations confirmed the diagnosis of inflammatory dentigerous cyst. As treatment, enucleation of the cyst with removal of the involved permanent tooth was chosen and a removable partial denture was supplied to the patient after surgery. The 5-year follow-up revealed good healing of the bony lesion and displaced teeth.

CONCLUSION

This case presented a severe and rare complication of endodontically treated primary tooth, and the recommendation includes: (1) early diagnosis of dentigerous cysts, which is essential to prevent extensive treatment; (2) more information on the adverse side effects of an endodontic treatment should be given to patients and parents; (3) patients should be informed about the importance of follow-ups and radiographic follow-up should be routinised.