Roadmap to functional cure of chronic hepatitis B: An expert consensus.

Hepatitis B virus (HBV) infection continues to be a major public health issue worldwide. HBsAg loss is associated with functional remission and improved long-term outcome, and is considered to be a 'functional cure' (also referred to as clinical or immunologic cure) for chronic hepatitis B. This ideal goal of therapy can be achieved using optimized combination regimens with direct-acting antivirals [eg nucleos(t)ide analogues (NAs)] and immunomodulators [eg pegylated interferon alpha2a (Peg-IFN)] in selected patients with chronic hepatitis B. Among different combination therapies currently available, those with NA lead-in followed by Peg-IFN in virally suppressed patients has been demonstrated to be effective. This review provides an updated overview of the evidence supporting the use of combination therapies and summarizes expert consensus on the roadmap to attain functional cure for chronic hepatitis B patients.

Exposure of patient and dental staff to fine and ultrafine particles from scanning spray.

OBJECTIVES: Sprays containing fine and ultrafine particles are commonly used for optical scanning. The aim of this study was to measure the particle exposure of patient and dentist during application of scanning spray and to evaluate measures for its reduction. MATERIALS AND METHODS: A lower molar in a dental simulator was powdered with scanning spray. Patient's particle exposure was measured by a condensation particle counter in the nasal region of the simulator without (P) and with rubber dam (PC). Dentist's exposure (D) was measured behind a surgical mask. Particle concentrations were determined 5-fold without suction (NS), using conventional dental suction (CDS), or high volume evacuation (HVE). RESULTS: Mean background air particle concentrations for the patient were 3.3 × 10(3) and 1.3 × 10(3) pt/cm(3) for the dentist. Particle concentrations increased after spraying; mean cumulated additional particle exposures for the patient were the following: P-NS 7.2 × 10(6), P-CDS 4.6 × 10(6), P-HVE 2.4 × 10(4); using rubber dam: PC-NS 3.6 × 10(6), PC-CDS 3.3 × 10(5), PC-HVE 2.2 × 10(5). The particle exposures of the dentist were the following: D-NS 9.7 × 10(5), D-CDS 1.8 × 10(5), D-HVE 1.6 × 10(4). CONCLUSIONS: The use of HVE is recommended to reduce exposure of patients and dental staff to fine and ultrafine particles when using scanning sprays. CLINICAL RELEVANCE: Effective protection is available for staff and patient by means of high volume evacuation. In patients suffering from obstructive lung diseases, the use of scanning sprays should be avoided altogether.

[Comparison of biological characteristics of human gingival junctional epithelial cells and oral epithelial cells].

OBJECTIVE: To isolate P-cadherin positive and negative oral gingival epithelial cells, and to compare the biological characteristics with junctional epithelial cells. METHODS: Human oral gingival epithelial cells and junctional epithelial cells were cultured. P-cadherin positive and negative cells were isolated from oral gingival epithelial cells. The cellular adhesion, proliferation and migration were measured and compared. RESULTS: The P-cadherin positive cells accounted for 20% of oral gingival epithelial cells. Compared with juctional epithelial cells, P-cadherin positive oral gingival epithelial cells showed similar properties of adhesion and migration, and stronger proliferation ability (0.72 ± 0.06 vs. 0.60 ± 0.05, P<0.05). P-cadherin negative oral gingival epithelial cells showed weaker ability of adhesion (48% ± 6% vs. 87% ± 11%, P<0.05), proliferation (0.36 ± 0.04 vs. 0.60 ± 0.05, P<0.05) and migration (10.3 ± 2.7 vs. 23.4 ± 4.8, P<0.05). CONCLUSION: P-cadherin positive oral gingival epithelial cells showed some similar but different biological characteristics, compared with juctional epithelial cells, which suggested that during the process of transforming oral gingival epithelial cells into juctional epithelial cells, complex gene and protein changes were involved instead of simply cellular migration.

Case report: A novel variant (H49N) in Myelin Protein Zero gene is responsible for a patient with Charcot-Marie-Tooth disease.

This report presents a case of Charcot-Marie-Tooth dominant intermediate D (CMTDID), a rare subtype of Charcot-Marie-Tooth disease, in a 52 years-old male patient. The patient exhibited mobility impairment, foot abnormalities (pes cavus), and calf muscle atrophy. Whole exome sequencing and Sanger sequencing suggested that a novel variant (NM_000530.8, c.145C>A/p.His49Asn) of MPZ may be the genetic lesion in the patient. The bioinformatic program predicted that the new variant (p.His49Asn), located at an evolutionarily conserved site of MPZ, was neutral. Our study expands the variant spectrum of MPZ and the number of identified CMTDID patients, contributing to a better understanding of the relationship between MPZ and CMTDID.

Separation of microplastic from soil by centrifugation and its application to agricultural soil.

The increasing contamination of the environment with microplastic requires efficient methods for the separation and detection of these plastic particles. In this work, we present a protocol that uses Fenton oxidation to remove biological material, centrifugation to separate microplastics from soil, and Nile Red staining, fluorescence microscopy, and image processing to detect and quantify of microplastic. The main component of this work was the separation process using centrifugation. All the main polymers used in this work, polyethylene, polypropylene, polystyrene, poly (vinyl chloride), and poly (ethylene terephthalate), were efficiently recovered at more than 94 wt% from heat-altered soil using CaCl2 solution with a density of 1.4 g ml-1. The hydrophilicity of the polymer had a greater effect on the recovery than density. The protocol was then tested on agricultural soil sampled near a contaminated site. The number of microplastic particles was quantified, and the weight of microplastic in the soil was estimated. The highest contamination was observed near the hotspot at a distance of 1 m with 75✕103 particles kg-1, corresponding to a weight between 20 and 6 mg kg-1. The number of particles decreased logarithmically to 30✕103 particles kg-1 or 5 to 2 mg kg-1.

The variation in crown-root morphology of anterior teeth assessed with cone-beam computed tomography.

OBJECTIVE: To determine the discrepancy of crown-root morphology of anterior teeth, using cone-beam computed tomography (CBCT), and to provide a guidance for proper torque expression. METHODS: A total of eligible 200 CBCT were imported into Invivo v. 5.4 software, to obtain the middle labio-lingual sections of anterior teeth. AutoCAD 2007 software was applied to measure the crown-root angulation (Collum angle) and the angle formed by a tangent to the center of the labial surface and the long axis of the crown (labial surface angle). SPSS 18.0 was used for statistical comparisons of the two measurements, at the level of p< 0.05, and the Pearson correlation analysis was applied to investigate the association between the two measurements. RESULTS: The value of Collum angle in maxillary central incisor was close to 0°. Significantly negative Collum angle in lateral incisors and maxillary canine, and positive value in mandibular canine were detected (p < 0.001). The labial surface angle in canine was significantly greater than the intra-arch incisors (p< 0.001), and no significant difference was detected between the central and lateral incisors (p > 0.05). Notably, there was also a significant positive correlation between the two measurements. CONCLUSIONS: The crown-root angulations were greatly different among anterior teeth. Accompanying the obvious crown-root angulations, the canines both in maxillary and mandibular arches presented considerable labial surface curvatures. Hence, equivalent deviation during bracket bonding might cause greater torque expression error and increase the risk of alveolar fenestration and dehiscence.

[Improved mechanical strength and cell occlusivity of electrospun L-polylactic acid aligned nanofibrous membranes by post heat treatment].

Electrospun nanofibrous materials are considered as ideal scaffolds for tissue engineering because their fibrous structure is quite similar to the morphology of natural extracellular matrix, and they can offer biomimetic microenvironment for cell growth. However, the highly porous scaffolds are too weak to meet the mechanical requirement of guided tissue regeneration (GTR). In the present investigation, electrospun L-polylactic acid (PLLA) nanofibrous membranes were collected with high speed rolling method, and then hot stretched and annealed to improve the tensile strength and cell occlusivity. The membrane with the maximum tensile strength (strength 103MPa and modulus 1.83GPa) was obtained by hot-stretching for twice at 100 degrees C and further annealed for 10min at the same temperature. Cytotoxicity test showed that the heat treated membrane supported well the attachment and growth of human periodontal ligament cells, but inhibited the cell proliferation. The cell occlusivity of the membrane was also significantly improved as the porosity decreased after heat treatment. It could be used as the enhancement interlayer of barrier materials for GTR.

Nuclear factor 1 and T-cell factor/LEF recognition elements regulate Pitx2 transcription in pituitary development.

Pitx2, a paired-related homeobox gene that is mutated in Rieger syndrome I, is the earliest known marker of oral ectoderm. Pitx2 was previously shown to be required for tooth, palate, and pituitary development in mice; however, the mechanisms regulating Pitx2 transcription in the oral ectoderm are poorly understood. Here we used an in vivo transgenic approach to investigate the mechanisms regulating Pitx2 transcription. We identified a 7-kb fragment that directs LacZ expression in oral ectoderm and in many of its derivatives. Deletion analysis of transgenic embryos reduced this fragment to a 520-bp region that directed LacZ activity to Rathke's pouch. A comparison of the mouse and human sequences revealed a conserved nuclear factor 1 (NF-1) recognition element near a consensus T-cell factor (TCF)/LEF binding site. The mutation of either site individually abolished LacZ activity in transgenic embryos, identifying Pitx2 as a direct target of Wnt signaling in pituitary development. These findings uncover a requirement for NF-1 and TCF factors in Pitx2 transcriptional regulation in the pituitary and provide insight into the mechanisms controlling region-specific transcription in the oral ectoderm and its derivatives.

A simple and efficient method for generating Nurr1-positive neuronal stem cells from human wisdom teeth (tNSC) and the potential of tNSC for stroke therapy.

BACKGROUND AIMS: We have isolated human neuronal stem cells from exfoliated third molars (wisdom teeth) using a simple and efficient method. The cultured neuronal stem cells (designated tNSC) expressed embryonic and adult stem cell markers, markers for chemotatic factor and its corresponding ligand, as well as neuron proteins. The tNSC expressed genes of Nurr1, NF-M and nestin. They were used to treat middle cerebral artery occlusion (MCAO) surgery-inflicted Sprague-Dawley (SD) rats to assess their therapeutic potential for stroke therapy. METHODS: For each tNSC cell line, a normal human impacted wisdom tooth was collected from a donor with consent. The tooth was cleaned thoroughly with normal saline. The molar was vigorously shaken or vortexed for 30 min in a 50-mL conical tube with 15-20mL normal saline. The mixture of dental pulp was collected by centrifugation and cultured in a 25-cm(2) tissue culture flask with 4-5mL Medium 199 supplemented with 5-10% fetal calf serum. The tNSC harvested from tissue culture, at a concentration of 1-2x10(5), were suspended in 3 microL saline solution and injected into the right dorsolateral striatum of experimental animals inflicted with MCAO. RESULTS: Behavioral measurements of the tNSC-treated SD rats showed a significant recovery from neurologic dysfunction after MCAO treatment. In contrast, a sham group of SD rats failed to recover from the surgery. Immunohistochemistry analysis of brain sections of the tNSC-treated SD rats showed survival of the transplanted cells. CONCLUSIONS: These results suggest that adult neuronal stem cells may be procured from third molars, and tNSC thus cultivated have potential for treatment of stroke-inflicted rats.

[Study on DNA methylation profiles in non-syndromic cleft lip/palate based on bioinformatics].

PURPOSE: To study DNA methylation patterns of non-syndromic cleft lip/palate(NSCL/P) using bioinformatic methods, including methylated positions and regions. METHODS: Whole blood DNA methylation data of NSCL/P samples was download from Gene Expression Omnibus(GEO) database, including 67 NSCL/P cases and 59 controls without birth defects. Data analysis included ①data cleaning, such as probes filtering, quality control and normalization; ②differential methylation analysis, including methylated positions and regions; ③Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis on differential methylated genes. R 3.4.3 software was used for data cleaning, differential methylated positions and regions analysis. DAVID6.8 tool was used for GO and KEGG analysis. RESULTS: 814 differential methylated positions were detected (adjusted P＜0.001，|Δß|＞0.125）, of which 178 were hypermethylated in NSCL/P patients, and 636 were hypomethylated. In addition, 386 differential methylated regions were identified (P＜0.05), of which 204 were hypermethylation regions and 182 were hypomethylation regions. GO analysis showed that 38 differential methylated genes were involved in 7 kinds of biological processes, 163 differential methylated genes were involved in 3 kinds of molecular functions, and 114 differential methylated genes were involved in 3 kinds of cellular components (P＜0.01). KEGG analysis showed that 59 differential methylated genes were involved in 9 kinds of signal pathways. CONCLUSIONS: Abnormal DNA methylation patterns of NSCL/P might be an important epigenetic mechanism affecting the development of NSCL/P. This study might contribute to the identification of identification of biomarkers and targeted interventions of NSCL/P.

Improved biological characteristics of poly(L-lactic acid) electrospun membrane by incorporation of multiwalled carbon nanotubes/hydroxyapatite nanoparticles.

Significant effort has been devoted to fabricating various biomaterials to satisfy specific clinical requirements. In this study, we developed a new type of guided tissue regeneration (GTR) membrane by electrospinning a suspension consisting of poly( l-lactic acid), multiwalled carbon nanotubes, and hydroxyapatite (PLLA/MWNTs/HA). MWNTs/HA nanoparticles were uniformly dispersed in the membranes, and the degradation characteristics were far improved. Cytologic research revealed that the PLLA/MWNTs/HA membrane enhanced the adhesion and proliferation of periodontal ligament cells (PDLCs) by 30% and inhibited the adhesion and proliferation of gingival epithelial cells by 30% also, compared with the control group. After PDLCs were seeded into the PLLA/MWNTs/HA membrane, cell/membrane composites were implanted into the leg muscle pouches of immunodeficient mice. Histologic examinations showed that PDLCs attached on the membranes functioned well in vivo. This new type of membrane shows excellent dual biological functions and satisfied the requirement of the GTR technique successfully in spite of a monolayer structure. Compared with other GTR membranes on sale or in research, the membrane can simplify the manufacturing process, reduce the fabrication cost, and avoid possible mistakes in clinical application. Moreover, it does not need to be taken out after surgery. PLLA/MWNTs/HA membranes have shown great potential for GTR and tissue engineering.

Poly-L-lactic acid/hydroxyapatite hybrid membrane for bone tissue regeneration.

Poly-L-lactic acid (PLLA)/hydroxyapatite (HA) hybrid membranes were fabricated via electrospinning of the PLLA/HA dispersion for use in bone tissue regeneration. The structural properties and morphologies of PLLA and PLLA/HA hybrid membrane were investigated by measuring the Brunauer-Emmett-Teller specific surface area, observations of SEM, and TEM. The dispersion and integrating of HA nanoparticles in the hybrid membrane were studied by energy dispersion X-ray analysis and FTIR. The mechanical properties of PLLA/HA membrane were also measured by tensile tests. For exploring biological behaviors of the hybrid membrane, in vitro degradation tests were carried out. The osteoblast cell (MG-63) was cultured in PLLA/HA hybrid membrane extract containing medium; the cell adhesion and growth capability were investigated by SEM observation and MTT assay. HA nanoparticles were not only dispersed in the PLLA but also reacted with the functional group of PLLA, resulting in strong surface bonding and high tensile strength of hybrid membrane. The cell adhesion and growth on the PLLA/HA hybrid membrane were far better than those on the pure PLLA membrane, which proves that the PLLA/HA hybrid membrane can be one of the promising biomaterials for bone tissue regeneration.

[Construction of 3D complex of porous beta-tricalcium phosphate/collagen scaffolds and dog periodontal ligament cells].

OBJECTIVE: To investigate the construction of 3D complex of porous beta-tricalcium phosphate/collagen scaffolds (beta-TCP/col) and dog periodontal ligament cells (PDLCs). METHODS: Dog PDLCs were isolated, cultured and identified. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate the cytotoxicity of beta-TCP/col on the proliferation of PDLCs. The cells were seeded onto porous beta-TCP/col scaffolds. The cellular capability of adhesion and growth on porous beta-TCP/col surface was investigated visually by scanning electron microscopy (SEM). RESULTS: The cytotoxicity assay indicated that there was no significant difference between beta-TCP/col and the control during the 7 days (P>0.05). SEM showed cells successfully adhered to porous beta-TCP/col scaffolds and spread extensively. Matrix secretions were found on the cell surface. CONCLUSION: Porous beta-tricalcium phosphate/collagen scaffolds were of good biocompatibility to the dog periodontal ligament cells, and were potential ideal candidates for periodontal tissue engineering.

The evaluation of trustworthiness to identify health insurance fraud in dentistry.

OBJECTIVE: According to the investigations of the U.S. Government Accountability Office (GAO), health insurance fraud has caused an enormous pecuniary loss in the U.S. In Taiwan, in dentistry the problem is getting worse if dentists (authorized entities) file fraudulent claims. Several methods have been developed to solve health insurance fraud; however, these methods are like a rule-based mechanism. Without exploring the behavior patterns, these methods are time-consuming and ineffective; in addition, they are inadequate for managing the fraudulent dentists. METHODS: Based on social network theory, we develop an evaluation approach to solve the problem of cross-dentist fraud. The trustworthiness score of a dentist is calculated based upon the amount and type of dental operations performed on the same patient and the same tooth by that dentist and other dentists. RESULTS: The simulation provides the following evidence. (1) This specific type of fraud can be identified effectively using our evaluation approach. (2) A retrospective study for the claims is also performed. (3) The proposed method is effective in identifying the fraudulent dentists. CONCLUSIONS: We provide a new direction for investigating the genuineness of claims data. If the insurer can detect fraudulent dentists using the traditional method and the proposed method simultaneously, the detection will be more transparent and ultimately reduce the losses caused by fraudulent claims.

The variation in crown-root morphology of anterior teeth assessed with cone-beam computed tomography

ABSTRACT Objective: To determine the discrepancy of crown-root morphology of anterior teeth, using cone-beam computed tomography (CBCT), and to provide a guidance for proper torque expression. Methods: A total of eligible 200 CBCT were imported into Invivo v. 5.4 software, to obtain the middle labio-lingual sections of anterior teeth. AutoCAD 2007 software was applied to measure the crown-root angulation (Collum angle) and the angle formed by a tangent to the center of the labial surface and the long axis of the crown (labial surface angle). SPSS 18.0 was used for statistical comparisons of the two measurements, at the level of p< 0.05, and the Pearson correlation analysis was applied to investigate the association between the two measurements. Results: The value of Collum angle in maxillary central incisor was close to 0°. Significantly negative Collum angle in lateral incisors and maxillary canine, and positive value in mandibular canine were detected (p < 0.001). The labial surface angle in canine was significantly greater than the intra-arch incisors (p< 0.001), and no significant difference was detected between the central and lateral incisors (p > 0.05). Notably, there was also a significant positive correlation between the two measurements. Conclusions: The crown-root angulations were greatly different among anterior teeth. Accompanying the obvious crown-root angulations, the canines both in maxillary and mandibular arches presented considerable labial surface curvatures. Hence, equivalent deviation during bracket bonding might cause greater torque expression error and increase the risk of alveolar fenestration and dehiscence.

RESUMO Objetivo: Determinar a discrepância na morfologia coroa-raiz de dentes anteriores, utilizando tomografia computadorizada de feixe cônico (TCFC), e fornecer parâmetros para a expressão apropriada do torque. Método: No total, 200 tomografias elegíveis foram importadas para o software Invivo 5.4 para obtenção das secções médias vestibulolinguais dos dentes anteriores. Osoftware AutoCAD 2007 foi usado para medir a angulação coroa-raiz (ângulo Collum) e o ângulo formado por uma tangente ao centro da superfície vestibular da coroa e o longo eixo da coroa (ângulo da superfície vestibular). O software SPSS 18.0 foi utilizado para as comparações estatísticas das duas medições, com nível de significância de p< 0,05, e a análise de correlação de Pearson foi aplicada para investigar a associação entre as duas medições. Resultados: O valor do ângulo Collum do incisivo central superior foi próximo a 0°. Foram detectados valores significativamente negativos para o ângulo Collum nos incisivos laterais e caninos superiores, mas valores positivos nos caninos inferiores (p< 0,001). O ângulo da superfície vestibular no canino foi significativamente maior do que nos incisivos intra-arcada (p< 0,001), e nenhuma diferença significativa foi detectada entre incisivos centrais e laterais (p> 0,05). Também foi observada uma correlação positiva significativa entre as duas medições. Conclusões: As angulações coroa-raiz foram muito diferentes entre os dentes anteriores. Os caninos superiores e inferiores apresentaram considerável curvatura na superfície vestibular, associada a uma evidente angulação coroa-raiz. Consequentemente, desvios durante a colagem de braquetes podem desencadear maior erro na expressão de torque e aumentar o risco de fenestração alveolar e deiscência, sendo necessária uma avaliação antes da colagem.

Bio-inspired virus imprinted polymer for prevention of viral infections.

A novel virus-imprinted polymer for prevention of viral infection was prepared by anchoring molecularly imprinted polymer (MIP) on the surface of poly-dopamine (PDA)-coated silica particles. The imprinting reaction was carried out via self-polymerization of dopamine in the presence of a virus template. Plaque forming assay indicated that the MIP exhibited selective anti-viral infection properties for the template virus in complex media containing different interfering substances, and even other types of viruses. Remarkable dose-dependent and time-dependent inhibition of virus infection was observed due to the MIP's selective binding to the template virus. When the MIP was incubated with the virus and host cells together, rapid and selective adsorption of template viruses by the MIP prevented the viruses to infect the host cells in a period of 12h. The MIP was biocompatible and non-toxic, and had excellent stability and reusability. Furthermore, the MIPs prepared using different viruses as templates showed similar anti-viral infection properties. The MIP synthesized using dopamine as monomer and crude virus as template provided an attractive possibility for clinical applications in the field of antiviral therapy. STATEMENT OF SIGNIFICANCE: This is the first report to prepare artificial antibody (molecularly imprinted polymer, MIP) that can selectively prevent virus infection using dopamine self-polymerization system. Only MIP anchoring on the surface of poly-dopamine coated silica particles and polymerized using ammonium persulfate as radical initiator showed dose-dependent and time-dependent inhibition of template virus infection in complex media containing interferences and even other viruses. Viruses bond to MIP lost infectious capability. When incubated with virus and host cells, MIP rebond viruses rapidly and selectively to prevent viruses infecting host cells for 12h. The achieved MIPs were biocompatibility, non-toxicity with excellent stability and reusability, and can be used to different viruses. The bio-mimic MIPs provided an attractive prospect for clinical applications in antiviral therapy.

Depolymerization of microcrystalline cellulose by the combination of ultrasound and Fenton reagent.

In this study, the combined use of Fenton reagent and ultrasound to the pretreatment of microcrystalline cellulose (MCC) for subsequent enzyme hydrolysis was investigated. The morphological analysis showed that the aspect ratio of MCC was greatly reduced after pretreatment. The X-ray diffraction (XRD) and degree of polymerization (DP) analyses showed that Fenton reagent was more efficient in decreasing the crystallinity of MCC while ultrasound was more efficient in decreasing the DP of MCC. The combination of Fenton reaction and ultrasound, which produced the lowest crystallinity (84.8 ± 0.2%) and DP (124.7 ± 0.6) of MCC and the highest yield of reducing sugar (22.9 ± 0.3 g/100 g), provides a promising pretreatment process for MCC depolymerization.

Side-chain charge effects and conductance determinants in the pore of ClC-0 chloride channels.

The charge on the side chain of the internal pore residue lysine 519 (K519) of the Torpedo ClC-0 chloride (Cl-) channel affects channel conductance. Experiments that replace wild-type (WT) lysine with neutral or negatively charged residues or that modify the K519C mutant with various methane thiosulfonate (MTS) reagents show that the conductance of the channel decreases when the charge at position 519 is made more negative. This charge effect on the channel conductance diminishes in the presence of a high intracellular Cl- concentration ([Cl-]i). However, the application of high concentrations of nonpermeant ions, such as glutamate or sulfate (SO42-), does not change the conductance, suggesting that the electrostatic effects created by the charge at position 519 are unlikely due to a surface charge mechanism. Another pore residue, glutamate 127 (E127), plays an even more critical role in controlling channel conductance. This negatively charged residue, based on the structures of the homologous bacterial ClC channels, lies 4-5 A from K519. Altering the charge of this residue can influence the apparent Cl- affinity as well as the saturated pore conductance in the conductance-Cl- activity curve. Amino acid residues at the selectivity filter also control the pore conductance but mutating these residues mainly affects the maximal pore conductance. These results suggest at least two different conductance determinants in the pore of ClC-0, consistent with the most recent crystal structure of the bacterial ClC channel solved to 2.5 A, in which multiple Cl--binding sites were identified in the pore. Thus, we suggest that the occupancy of the internal Cl--binding site is directly controlled by the charged residues located at the inner pore mouth. On the other hand, the Cl--binding site at the selectivity filter controls the exit rate of Cl- and therefore determines the maximal channel conductance.

Enhanced osteogenic differentiation of mesenchymal stem cells on poly(L-lactide) nanofibrous scaffolds containing carbon nanomaterials.

Carbon nanomaterials (CNMs), such as carbon nanotube (CNT) and graphene, are highlighted in bone regeneration because of their osteoinductive properties. Their combinations with nanofibrous polymeric scaffolds, which mimic the morphology of natural extracellular matrix of bone, arouse keen interest in bone tissue engineering. To this end, CNM were incorporated into nanofibrous poly(L-lactic acid) scaffolds by thermal-induced phase separation. The CNM-containing composite nanofibrous scaffolds were biologically evaluated by both in vitro co-culture of bone mesenchymal stem cells (BMSCs) and in vivo implantation. The nanofibrous structure itself demonstrated significant enhancement in cell adhesion, proliferation and oseogenic differentiation of BMSCs, and with the incorporation of CNM, the composite nanofibrous scaffolds further promoted osteogenic differentiation of BMSCs significantly. Between the two CNMs, graphene showed stronger effect in promoting osteogenic differentiation of BMSCs than CNT. The results of in vivo experiments revealed that the composite nanofibrous scaffolds had both good biocompatibility and strong ability in inducing osteogenesis. CNMs could remarkably enhance the expression of osteogenesis-related proteins as well as the formation of type I collagen. Similarly, the graphene-containing composite nanofibrous scaffolds demonstrated the strongest effect on inducing osteogenesis in vivo. These findings demonstrated that CNM-containing composite nanofibrous scaffolds were obviously more efficient in promoting osteogenesis than pure polymeric scaffolds.

[Oxidative stress and susceptibility of periodontal disease].

PURPOSE: To investigate the relationship between dietary antioxidant status and susceptibility of periodontal disease in humans. METHODS: Fifty patients with moderate-to-sever periodontal disease and 50 subjects without periodontal disease were enrolled in this study. Food frequency questionnaire and 72-hour diet recall were conducted to study the dietary pattern and antioxidant nutrients intake in patients and healthy subjects. Nutritional status including vitamins, mineral substance, and antioxidant enzymes in these 2 groups were analyzed in serum and saliva samples by liquid chromatography-mass spectrometry (LC-MS). SPSS 19.0 software package was used for paired t test. RESULTS: Compared with the control group, the chronic periodontal group had lower levels of potatoes, aquatic product, milk, soy, fresh vegetables, fruit and vitamin supplements intake(P<0.05). Through food components analysis we found that the intake of vitamin A, C, B2, E, calcium, magnesium, copper, selenium was significantly lower in the chronic periodontal disease group than that in the control group (P<0.05). Biochemical analysis demonstrated that antioxidant nutrient levels including antioxidant enzyme SOD in serum and saliva together with magnesium, calcium, manganese, zinc in saliva were significantly lower in disease periodontal group than in the control group (P<0.05). CONCLUSIONS: Oxidative stress plays an essential role in the occurrence and development of periodontal disease. The antioxidant nutrients may help to protect paradentium. Supported by Research Fund from Shanghai Municipal Health Bureau (20114103).