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1.
Caries Res ; 52(5): 347-358, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29510413

RESUMO

Streptococcus mutans is an important factor in the etiology and pathogenesis of dental caries, largely owing to its ability to form a stable biofilm. Previous animal studies have indicated that rnc could decrease the amount of sulcal caries, and that the downregulation of cariogenicity might be due to its capacity to disrupt biofilm formation. However, the biofunctions by which rnc is involved in biofilm formation remain to be elucidated. In this study, we further investigate the role of rnc based on the study of mature biofilm. Scanning electron microscopy and the crystal violet assay were used to detect the biofilm forming ability. The production and distribution of exopolysaccharides within biofilm was analyzed by exopolysaccharide staining. Gel permeation chromatography was used to perform molecular weight assessment. Its adhesion force was measured by atomic force microscopy. The expression of biofilm formation-associated genes was analyzed at the mRNA level by qPCR. Here, we found that rnc could occur and function in biofilm formation by assembling well-structured, exopolysaccharide-encased, stable biofilms in S. mutans. The weakened biofilm forming ability of rnc-deficient strains was associated with the reduction of exopolysaccharide production and bacterial adhesion. Over all, these data illustrate an interesting situation in which an unappreciated regulatory gene acquired for virulence, rnc, most likely has been coopted as a potential regulator of biofilm formation in S. mutans. Further characterization of rnc may lead to the identification of a possible pathogenic biofilm-specific treatment for dental caries.


Assuntos
Biofilmes/crescimento & desenvolvimento , Genes Bacterianos/fisiologia , Streptococcus mutans/genética , Cromatografia em Gel , Genes Bacterianos/genética , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Reação em Cadeia da Polimerase em Tempo Real , Streptococcus mutans/crescimento & desenvolvimento
2.
BMC Pediatr ; 14: 256, 2014 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-25286833

RESUMO

BACKGROUND: Mandibuloacral dysplasia type A (MADA) is a rare autosomal recessive disorder, characterized by growth retardation, skeletal abnormality with progressive osteolysis of the distal phalanges and clavicles, craniofacial anomalies with mandibular hypoplasia, lipodystrophy and mottled cutaneous pigmentation. Some patients may show progeroid features. MADA with partial lipodystrophy, more marked acral, can be caused by homozygous or compound heterozygous mutation in the gene encoding lamin A and lamin C (LMNA). MADA and Hutchinson-Gilford progeria syndrome are caused by the same gene and may represent a single disorder with varying degrees of severity. MAD patients characterized by generalized lipodystrophy (type B) affecting the face as well as extremities and severe progressive glomerulopathy present heterozygous compound mutations in the ZMPSTE24 gene. CASES PRESENTATIONS: We described a rare pedigree from Southern China, among them all three children presented with phenotypes of MADA associated progeria. The two elder sisters had developed severe mandibular hypoplasia associated progeria since the age of 1 year. The eldest sister showed a progressive osteolysis. The youngest son of 10 months showed severer lesions than those of his sisters at the same age, and presented possible muscle damage, and his symptoms progressed gradually. Three genes mutations including LMNA, ZMPSTE24 and BANF1 were tested in the family. LMNA gene sequencing revealed a homozygous missense mutation, c.1579C > T, p.R527C for all three siblings, and heterozygous mutations for their parents, whereas no mutations of ZMPSTE24 and BANF1 genes was detected among them. CONCLUSIONS: The same homozygous mutation of c.1579C > T of LMNA gene led to MADA associated progeria for the present family. The course of osteolysis for MADA is progressive.


Assuntos
Acro-Osteólise/genética , Homozigoto , Lamina Tipo A/genética , Lipodistrofia/genética , Mandíbula/anormalidades , Mutação , Progéria/genética , Povo Asiático/genética , Criança , Pré-Escolar , China , Feminino , Humanos , Lactente , Masculino , Osteólise/genética , Linhagem , Doenças Raras/genética , Irmãos
3.
Am J Dent ; 26(5): 239-43, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24479273

RESUMO

PURPOSE: To investigate the effects of exogenous dextranase and sodium fluoride on a S. mutans monospecies biofilm. METHODS: S. mutans 25175 was grown in tryptone soya broth medium, and biofilm was formed on glass slides with 1.0% sucrose. Exogenous dextranase and sodium fluoride were added alone or together. The biofilm morphology was analyzed by confocal laser scanning microscopy. The effects of the drug on the adhesion and exopolysaccharide production by the biofilms were evaluated by scintillation counting and the anthrone method, respectively. RESULTS: In this study, we found that the structure of initial biofilm and mature biofilm were partly altered by dextranase and high concentrations of sodium fluoride separately. However, dextranase combined with a low concentration of sodium fluoride could clearly destroy the typical tree-like structure of the biofilm, and led to less bacterial adhesion than when the dextranase or fluoride were used alone (P < 0.05). The amounts of soluble and insoluble exopolysaccharide were significantly reduced by combining dextranase with a low concentration of sodium fluoride, much more than when they were used alone (P < 0.05). These data indicate that dextranase and a low concentration of sodium fluoride may have synergistic effects against S. mutans biofilm and suggest the application of a low concentration of sodium fluoride in anticaries treatment.


Assuntos
Biofilmes/efeitos dos fármacos , Cariostáticos/farmacologia , Dextranase/farmacologia , Fluoreto de Sódio/farmacologia , Streptococcus mutans/efeitos dos fármacos , Aderência Bacteriana/efeitos dos fármacos , Técnicas Bacteriológicas , Combinação de Medicamentos , Sinergismo Farmacológico , Humanos , Microscopia Confocal , Polissacarídeos Bacterianos/metabolismo , Solubilidade/efeitos dos fármacos , Streptococcus mutans/fisiologia , Sacarose/farmacologia
4.
ChemSusChem ; 16(11): e202300170, 2023 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-36828776

RESUMO

Industrial waste gas is one of the major sources of atmospheric CO2 , yet the direct conversion of the low concentrations of CO2 in waste gases into high value-added chemicals have been a great challenge. Herein, a copper-based N-heterocyclic carbene porous polymer catalyst (Cu@NHC-1) for the direct conversion of low concentration CO2 into oxazolidinones was successfully fabricated via a facile copolymerization process followed by the complexation with Cu(OAc)2 . A continuous flow device was designed to deliver a continuous and stable carbon source for the reaction. Due to the triple synergistic effect of its porous structure, nitrogen activation sites and catalytic Cu center, Cu@NHC-1 shows highly efficient and selective adsorption, activation, and conversion of the low concentration CO2 (30 vol%). Its practical application potential is demonstrated by the ability to successfully convert the CO2 in lime kiln waste gas into oxazolidinones in satisfactory yields under mild conditions.


Assuntos
Dióxido de Carbono , Oxazolidinonas , Dióxido de Carbono/química , Cobre/química , Polímeros/química , Porosidade , Gases , Catálise
5.
Bioorg Med Chem Lett ; 21(11): 3268-72, 2011 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-21524910

RESUMO

Prothrombin is a vitamin K-dependent serine protease and plays pivotal roles in both procoagulant and anticoagulant pathway of hemostasis. In this study, prothrombin purified from porcine plasma was modified through PEGylation at N-terminal residue using 40 kDa PEG-phenyl-isothiocyanate (PIT-PEG40K). The monoPEGylated prothrombin enhanced biostability and remarkably prolonged circulating half-life in mice as compared with that of the nonmodified prothrombin. Moreover, the immunogenicity of PEGylated prothrombin in mice is significantly decreased compared to nonmodified prothrombin. These studies demonstrated the feasibility of PEGylating prothrombin as a promising way for the development of new prothrombin drugs.


Assuntos
Polietilenoglicóis , Protrombina/química , Animais , Estabilidade de Medicamentos , Fenômenos Imunogenéticos/efeitos dos fármacos , Camundongos , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Protrombina/farmacologia , Suínos
6.
Oral Health Prev Dent ; 19(1): 279-285, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-34057337

RESUMO

PURPOSE: To explore potential caries risk indicators in 3- to 5-year-old children, and develop a simple risk-score model to screen the children at high risk of caries with decayed, filled, and missing teeth (dmft) > 2. MATERIALS AND METHODS: A cross-sectional study involving 2746 children 3 to 5 years of age was conducted in Sichuan province. Children were examined for dmft index, and sociodemographic and behavioural factors were acquried through a questionnaire completed by their caregivers. A prediction model was developed by backward multivariate logistic regression, and its overfitting degree was examined with 5-fold cross-validation. A simple risk-score model was derived to screen the children with dmft > 2 at high risk of caries with the ß regression coefficient obtained from the multivariate regression model. RESULTS: A child's oral health status was identified as the highest risk indicator with a ß regression coefficient of 1.093. The mean area under curve (AUC) from the 5-fold cross-validation was 0.7408 (95% CI: 72.21%, 75.95%), with a bias of only ca 1%. This result allowed us to eliminate substantial overfitting of the prediction model. The AUC of the risk scoring system was 0.7455 (95% CI: 72.70%, 76.40%), which indicated good screenability. CONCLUSIONS: This risk score model has the advantages of simplicity, low cost and relatively high accuracy, and is suitable for use in developing countries, especially for primary screening for high risk of caries. It shows that certain child behaviours and parental attitude play an important role in dental caries among preschool children.


Assuntos
Cárie Dentária , Pré-Escolar , Estudos Transversais , Cárie Dentária/epidemiologia , Suscetibilidade à Cárie Dentária , Humanos , Fatores de Risco , Inquéritos e Questionários
7.
ACS Appl Mater Interfaces ; 11(7): 7459-7471, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30676017

RESUMO

Ceramifiable polyolefin materials have an excellent application prospect in high-temperature-resistant wires and cables because of their excellent fire safety performance via a ceramization process under fire conditions. During the ceramization process, the control of the crystalline phase plays a vital role in determining the final fire resistance and ceramifiable properties. In this work, ammonium polyphosphate/zinc borate (APP/ZB) was developed to achieve the highly efficient flame retardance and ceramization of the ethylene-vinyl acetate/mica powder/organo-modified montmorillonite (EVA/MP/OMMT) composite. In the combustion test, the EVA/MP/OMMT/APP/ZB system displayed obvious flame retardance feature, showing much lower total heat release and total smoke production than neat EVA. After treating at high temperatures, rigid ceramic products were formed for EVA/MP/OMMT/APP/ZB. The ceramic that was formed at 900 °C had a flexural strength of 10.3 MPa for EVA/MP/OMMT/APP/ZB containing 23 wt % of APP/ZB (9.9:13.1), increased by 2475.0, 635.7, and 586.7% compared to the corresponding values of EVA/MP/OMMT, EVA/MP/OMMT/ZB, and EVA/MP/OMMT/APP. For the latter two systems, the content of ZB or APP was 23 wt %. APP/ZB showed a remarkable fluxing effect on the ceramization of the MP-based EVA composite. The fluxing mechanism of APP/ZB was revealed by different measurements. Both APP and ZB led to the formation of a glass melt containing α-Zn3(PO4)2 and orthophosphate by increasing the temperature. Successively, the melt crystalline structure cohered the OMMT and MP together, accompanied by the gradual disappearance of the mica phase and the generation of eutectic phenomenon. Finally, a ceramic with high flexural strength was formed, leading to the improved flame retardance and ceramifiable properties of EVA-based composites.


Assuntos
Bentonita/química , Retardadores de Chama , Temperatura Alta , Polifosfatos/química , Polivinil/química , Compostos de Vinila/química
8.
J Ethnopharmacol ; 240: 111870, 2019 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-30980892

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Pudilan is a famous traditional Chinese medicine compound which contains several Chinese herbal ingredients, and has been wildly used to treat a variety of inflammatory diseases in China. Recently, it was reported that Pudilan extract had been used in the oral field, especially in the treatment of minor oral ulcers for its anti-inflammatory, pain relieving, antibacterial, clearing heat, and detoxifying effects. AIM OF THE STUDY: To evaluate the effectiveness and safety of Pudilan extract-containing toothpaste in controlling plaques and reducing chronic gingivitis. MATERIALS AND METHODS: A total of 120 patients with chronic gingivitis were randomized into an experiment group and a control group (n = 60 patients per group) based on a double-blinded method. Patients in the experiment group used a Pudilan extract-containing toothpaste, whereas patients in the control group used a Pudilan toothpaste simulator, which were identical as the toothpaste used by the experiment group, except for not containing the Pudilan extract. The Plaque Index (PI), Gingival Index (GI), Bleeding Index (BI), and Bleeding On Probing proportion (BOP%) were recorded at baseline, 4 weeks, 8 weeks and 12 weeks after using the toothpaste. RESULTS: After using the toothpaste for 8 and 12 weeks, PI, BI, GI, and BOP% of the experiment group were significantly lower when compared to the control group (both p < 0.001). Moreover, after using the toothpaste for 4, 8, and 12 weeks, the decline of the PI and GI in the experiment group were significantly higher than the control group (p < 0.001, except 4weeks PI p = 0.011). After 12 weeks, the PI of the experiment group decreased 35.73% (p < 0.001) whereas the GI decreased 29.04% (p < 0.001). BI and BOP decline rates were statistically significant when compared to those of the control group at 8 and 12 weeks (both p < 0.001). Moreover, at 12 weeks, the BI of the experiment group decreased 34.33% (p < 0.001) and BOP% decreased 54.71% (p < 0.001). CONCLUSION: Toothpaste with Pudilan extract demonstrated good effect on relieving symptoms of chronic gingivitis by inhibiting plaque formation, reducing gingival inflammation and the degree of bleeding, and the bleeding rate. Toothpaste containing Pudilan extract has prospective application potentials in the prevention and treatment of chronic gingivitis.


Assuntos
Anti-Inflamatórios/uso terapêutico , Medicamentos de Ervas Chinesas/uso terapêutico , Gengivite/tratamento farmacológico , Hemorragia/tratamento farmacológico , Cremes Dentais/uso terapêutico , Adulto , Doença Crônica , Índice de Placa Dentária , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice Periodontal , Adulto Jovem
9.
Chin J Dent Res ; 21(3): 213-220, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30255172

RESUMO

OBJECTIVE: To investigate the dental caries status and related factors in Chinese elderly people, using data from the 4th National Oral Health Survey of China. METHODS: In this cross-sectional study, a multistage, cluster strategy was used to recruit 4,431participants (2,222 male and 2,209 female) aged 65 to 74 years from all 31 provinces, autonomous regions and municipalities of the mainland of China. The survey was performed according to the diagnostic standard proposed by the World Health Organization (WHO). Socio-demographic information was collected with a closed questionnaire. RESULTS: The caries prevalence in 65 to 74-year-olds was rather high; the report shows it was 98.0% (DMFT ≥ 1) among elderly people in China. The mean DMFT, DT, MT and FT was 13.33 ± 9.32, 3.33 ± 4.17, 9.50 ± 8.66 and 0.49 ± 1.41, respectively. The filling rate was very low, assessed as 12.8%. The number of DMFT related to gender, residential district type, educational level, level of annual household income, toothbrushing frequency, consumption frequency of desserts, attitudes to oral health and oral health-related knowledge. CONCLUSION: The prevalence of dental caries in Chinese elderly people is rather high and a lot of decayed teeth still need to be filled and suitable prevention and treatment for this group is urgently needed.


Assuntos
Cárie Dentária/epidemiologia , Escolaridade , Conhecimentos, Atitudes e Prática em Saúde , Refeições , Escovação Dentária/estatística & dados numéricos , Idoso , China/epidemiologia , Estudos Transversais , Índice CPO , Inquéritos de Saúde Bucal , Feminino , Humanos , Masculino , Prevalência , População Rural/estatística & dados numéricos , Distribuição por Sexo , Inquéritos e Questionários , População Urbana/estatística & dados numéricos
10.
Chin J Dent Res ; 21(3): 221-229, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30255173

RESUMO

OBJECTIVE: To investigate the differences in distribution of root caries and related factors between middle-aged and elderly people in China. METHODS: In this cross-sectional study, a multistage, cluster strategy was used to recruit 4,410 participants (2,197 males and 2,213 females) aged 35 to 44 years and 4,431 participants (2,222 males and 2,209 females) aged 65 to 74 years from all 31 provinces, autonomous regions and municipalities of the mainland of China. The survey was conducted according to the basic methods proposed by the World Health Organization (WHO). Sociodemographic information, oral health behaviour, attitude and knowledge, history of dental prophylaxis and general health condition were collected with a closed questionnaire. RESULTS: A great increase in the occurrence of root caries in Chinese adults from 35 to 44-year-old to 65 to 74-year-olds, with the prevalence (DFR ≥ 1) from 25.4% to 61.9% and with the mean DFR score from 0.54 ± 1.34 to 2.63 ± 3.75. Filling rates were also very low, only 1.8% and 3.0%, respectively. Females and residents of rural areas were more likely to suffer from root caries. In both the middle-aged group and the elderly group, root caries related to gender, education level, sweet food/drinks consumption, oral health knowledge and status of root surface explosion. In 35 to 44 year olds, toothbrushing is a significant protection factor (OR = 0.88, 95%CI 0.81 ~ 0.96), while using toothpicks is a risk factor (OR = 1.06, 95%CI 1.02 ~ 1.10). In 65 to 74 year olds, not having dental had scaling in the past 12 months is a risk factor (OR = 1.66, 95%CI 1.09 ~ 2.53). CONCLUSION: Root caries among middle-aged people and elderly people in China have different risk factors and need more attention in future research to develop proper prevention.


Assuntos
Raspagem Dentária/estatística & dados numéricos , Conhecimentos, Atitudes e Prática em Saúde , Cárie Radicular/epidemiologia , Escovação Dentária/estatística & dados numéricos , Adulto , Distribuição por Idade , Idoso , China , Inquéritos de Saúde Bucal , Sacarose Alimentar , Escolaridade , Feminino , Humanos , Masculino , Prevalência , Fatores de Risco , População Rural/estatística & dados numéricos , Distribuição por Sexo , População Urbana/estatística & dados numéricos
11.
Int J Oral Sci ; 9(2): 110-116, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28644431

RESUMO

To compare the efficacy of various irrigants (citric acid, ethylenediaminetetraacetic acid (EDTA) and NaOCl) and techniques in removing Ca(OH)2 in two types of curved root canal systems, simulated root canals with specific curvatures were used to investigate the effects of different irrigants and instruments on Ca(OH)2 removal. The optimal methods were verified on extracted human teeth. Simulated root canals were assigned to one of two groups based on the irrigation solution: 10% citric acid or 2.5% NaOCl. Each group was divided into four subgroups according to the technique used to remove Ca(OH)2. The percentage of Ca(OH)2 removal in different sections of root canals was calculated. On the basis of the results obtained for the simulated canals, 10% citric acid and 17% EDTA were applied to remove Ca(OH)2 from the extracted human teeth with curved root canal systems. The teeth were scanned by micro computed tomography to calculate the percentage of Ca(OH)2 removal in the canals. In simulated root canals, we found that 10% citric acid removed more Ca(OH)2 than 2.5% NaOCl in the 0-1 mm group from the apex level (P<0.05). Ultrasonic and EndoActivator activation significantly removed more Ca(OH)2 than a size 30 K file in the apical third (P<0.05). However, there were no significant differences in any sections of the canals for 10% citric acid or 17% EDTA in removing Ca(OH)2 in extracted human teeth. We concluded that it was effective to remove residual Ca(OH)2 using the decalcifying solution with EndoActivator or Passive Ultrasonic Irrigation in a curved root canal system. A protocol for Ca(OH)2 removal was provided based on the conclusions of this study and the methods recommended in previous studies.


Assuntos
Hidróxido de Cálcio/química , Instrumentos Odontológicos , Cavidade Pulpar/ultraestrutura , Irrigantes do Canal Radicular/química , Preparo de Canal Radicular/instrumentação , Ácido Cítrico/química , Ácido Edético/química , Humanos , Técnicas In Vitro , Hipoclorito de Sódio/química , Propriedades de Superfície , Ultrassom
12.
Int J Oral Sci ; 9(1): 10-15, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28358035

RESUMO

To investigate oral health status in the residents of Sichuan Province, southwest China, a cross-sectional study was performed using the latest Oral Health Survey Basic Methods recommended by the World Health Organization. A multistage stratified random cluster-sampling method was used to enroll participants from the following three groups: children aged 3-5 years, adolescents aged 12 years, and people aged 65-74 years. In these three groups, the mean numbers of teeth that were affected by caries were 3.28, 0.86 and 5.13, respectively, resulting in a prevalence of 63.47%, 37.20% and 83.20%, respectively. Relative to the high rate of decayed teeth, the prevalence of fillings was very low in all age groups (0.97%, 7.24% and 5.43%, respectively). In the 12-year-old adolescent group, only 3.61% had good pit and fissure sealing. In addition, the rate of dental fluorosis was 24.80%, and the Community Fluorosis Index value was 0.39. In the elder group, the community periodontal index was 2.92. The prevalence in the elderly of having lost at least one tooth was 75.54%. Additionally, 4.44% of these participants were edentulous. The incidence of dental prosthesis was 51.75%, the proportion with a removable partial denture, a fixed denture, full dentures, dental implants and an informal fixed bridge was 21.59%, 11.45%, 4.64%, 0 and 16.67%, respectively. In this study, 8.2% of the elderly participants were affected by different types of oral mucosal lesions. Among such lesions, recurrent aphthous ulcers were most prevalent (2.69%) and oral lichen planuses were second (1.6%). The conclusion presented in this survey is that oral diseases, especially dental caries and periodontal disease, are frequent and common in Sichuan province, China. Moreover, the treatment rate is very low, and primary prevention and treatment options are therefore urgently needed in this population.


Assuntos
Inquéritos de Saúde Bucal , Indicadores Básicos de Saúde , Doenças da Boca/epidemiologia , Saúde Bucal , Idoso , Criança , Pré-Escolar , China/epidemiologia , Estudos Transversais , Índice CPO , Feminino , Humanos , Masculino , Prevalência
13.
Sci Rep ; 6: 19212, 2016 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-26759029

RESUMO

The construction of synthetic straightforward, biocompatible and biodegradable targeted drug delivery system with fluorescent tracking abilities, high anticancer activities and low side effects is still a challenge in the field of biochemistry and material chemistry. In this work, we constructed targeted paclitaxel (Taxol) delivery nanoparticles composed of permethyl-ß-cyclodextrin modified hyaluronic acid (HApCD) and porphyrin modified paclitaxel prodrug (PorTaxol), through host-guest and amphiphilic interactions. The obtained nanoparticles (HATXP) were biocompatible and enzymatic biodegradable due to their hydrophilic hyaluronic acid (HA) shell and hydrophobic Taxol core, and exhibited specific targeting internalization into cancer cells via HA receptor mediated endocytosis effects. The cytotoxicity experiments showed that the HATXP exhibited similar anticancer activities to, but much lower side effects than commercial anticancer drug Taxol. The present work would provide a platform for targeted paclitaxel drug delivery and a general protocol for the design of advanced multifunctional nanoscale biomaterials for targeted drug/gene delivery.


Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Paclitaxel/administração & dosagem , Polissacarídeos/química , Animais , Materiais Biocompatíveis/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Teste de Materiais , Camundongos , Células NIH 3T3 , Nanopartículas/química , Nanopartículas/ultraestrutura , beta-Ciclodextrinas/química
14.
Front Microbiol ; 7: 687, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27242713

RESUMO

Dental caries is a biofilm-dependent disease that largely relies on the ability of Streptococcus mutans to synthesize exopolysaccharides. Although the rnc gene is suggested to be involved in virulence mechanisms in many other bacteria, the information regarding it in S. mutans is very limited. Here, using deletion or overexpression mutant assay, we demonstrated that rnc in S. mutans significantly positively regulated exopolysaccharide synthesis and further altered biofilm formation. Meanwhile, the cariogenecity of S. mutans was decreased by deletion of rnc in a specific pathogen-free (SPF) rat model. Interestingly, analyzing the expression at mRNA level, we found the downstream vic locus was repressed by rnc in S. mutans. Using deep sequencing and bioinformatics analysis, for the first time, three putative microRNA-size small RNAs (msRNAs) targeting vicRKX were predicted in S. mutans. The expression levels of these msRNAs were negatively correlated with vicRKX but positively correlated with rnc, indicating rnc probably repressed vicRKX expression through msRNAs at the post-transcriptional level. In all, the results present that rnc has a potential role in the regulation of exopolysaccharide synthesis and can affect vicRKX expressions via post-transcriptional repression in S. mutans. This study provides an alternative avenue for further research aimed at preventing caries.

15.
Biomed Res Int ; 2016: 4793146, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27525269

RESUMO

Root canal calcification is considered a great challenge during root canal treatment. Although the application of ultrasonic instruments and dental operating microscope (DOM) has advantages, dealing with calcified root canals still suffers a great risk of failure because of limited information about the location, length, and direction of obliteration on periapical radiographs. In this work, a cone-beam computed tomography- (CBCT-) aided method aimed at solving complicated calcified root canals in which conventional approaches could not work was proposed. Thirteen teeth with sixteen calcified canals (12 calcified in the upper third, 4 calcified in the middle third), which cannot be negotiated with conventional methods, were treated with the aid of CBCT. The location of calcification and depth of instrumentation and operating direction were calculated and assessed in three dimensions with ultrasonic instruments under DOM. In all thirteen teeth, canals with upper and middle thirds calcification were treated successfully. Finally, a guideline was proposed to help achieve consistent apical patency in calcified canals.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Calcificações da Polpa Dentária/diagnóstico por imagem , Calcificações da Polpa Dentária/terapia , Tratamento do Canal Radicular/métodos , Terapia por Ultrassom , Feminino , Humanos , Masculino
16.
Sci Rep ; 4: 7471, 2014 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-25503268

RESUMO

Constructing safe and effective gene delivery carriers is becoming highly desirable for gene therapy. Herein, a series of supramolecular crosslinking system were prepared through host-guest binding of adamantyl-modified low molecular weight of polyethyleneimine with L-cystine-bridged bis(ß-cyclodextrin)s and characterized by (1)H NMR titration, electron microscopy, zeta potential, dynamic light-scattering, gel electrophoresis, flow cytometry and confocal fluorescence microscopy. The results showed that these nanometersized supramolecular crosslinking systems exhibited higher DNA transfection efficiencies and lower cytotoxicity than the commercial DNA carrier gold standard (25 kDa bPEI) for both normal cells and cancer cells, giving a very high DNA transfection efficiency up to 54% for 293T cells. Significantly, this type of supramolecular crosslinking system possesses a number of enzyme-responsive disulfide bonds, which can be cleaved by reductive enzyme to promote the DNA release but recovered by oxidative enzyme to make the carrier renewable. These results demonstrate that these supramolecular crosslinking systems can be used as promising gene carriers.


Assuntos
Proliferação de Células , Cistina/química , DNA/administração & dosagem , Técnicas de Transferência de Genes , Terapia Genética , Polietilenoimina/química , beta-Ciclodextrinas/química , DNA/genética , Sistemas de Liberação de Medicamentos , Fluorescência , Células HEK293 , Células HeLa , Humanos , Microscopia Confocal , Reciclagem , Transfecção
17.
Nat Commun ; 5: 3329, 2014 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-24569383

RESUMO

Means for high-density multiparametric physiological mapping and stimulation are critically important in both basic and clinical cardiology. Current conformal electronic systems are essentially 2D sheets, which cannot cover the full epicardial surface or maintain reliable contact for chronic use without sutures or adhesives. Here we create 3D elastic membranes shaped precisely to match the epicardium of the heart via the use of 3D printing, as a platform for deformable arrays of multifunctional sensors, electronic and optoelectronic components. Such integumentary devices completely envelop the heart, in a form-fitting manner, and possess inherent elasticity, providing a mechanically stable biotic/abiotic interface during normal cardiac cycles. Component examples range from actuators for electrical, thermal and optical stimulation, to sensors for pH, temperature and mechanical strain. The semiconductor materials include silicon, gallium arsenide and gallium nitride, co-integrated with metals, metal oxides and polymers, to provide these and other operational capabilities. Ex vivo physiological experiments demonstrate various functions and methodological possibilities for cardiac research and therapy.


Assuntos
Algoritmos , Coração/fisiologia , Membranas Artificiais , Modelos Cardiovasculares , Pericárdio/fisiologia , Animais , Elastômeros/química , Eletrocardiografia/instrumentação , Eletrocardiografia/métodos , Eletrodos , Técnicas Eletrofisiológicas Cardíacas/instrumentação , Técnicas Eletrofisiológicas Cardíacas/métodos , Mapeamento Epicárdico/instrumentação , Mapeamento Epicárdico/métodos , Coração/anatomia & histologia , Sistema de Condução Cardíaco/fisiologia , Concentração de Íons de Hidrogênio , Imageamento Tridimensional , Técnicas In Vitro , Pericárdio/anatomia & histologia , Coelhos , Reprodutibilidade dos Testes , Semicondutores , Silicones/química , Temperatura
18.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 47(5): 277-80, 2012 May.
Artigo em Zh | MEDLINE | ID: mdl-22883822

RESUMO

OBJECTIVE: To analyze the stress distribution in temporomandibular joint (TMJ) with different depth of curve of Spee (CS) by three-dimensional finite element model (3D-FEM). METHODS: FEM with different depth of CS were established. The depth was 2.50, 0 and 4.50 mm (model 0, 1, 2). The stress distribution were analyzed by software Abaqus. The change of stress were analyzed by paried t test. RESULTS: The stress distribution patterns in TMJ with different depth of CS were similar. The Von Mises on the anterior surface of condyle and the Von Mises on the intermedial zone of the disc was higher. The S. Max. Principal of the condyle was mainly tensile stress. The S. Min. Principal of the condyle was mainly compressive stress. The S. Max. Principal of the disc was mainly tensile stress. The S.Min. Principal of the disc was mainly compressive stress.In model 0, the eviations of the Von Mises, the S.Max. Principal and the S.Min. Principal on the anterior surface of condyle were 0.1057 - 0.2298 MPa, -0.2243 - -0.3738 MPa and -0.3494 - -0.1165 MPa. The eviations of the Von Mises, the S.Max. Principal and the S. Min. Principal on the intermedial zone of the disc were 0.1099 - 0.6880 MPa, -0.3217 - 0 MPa and -1.2000 - -0.1000 MPa. The D-values of of Von Mises of condyle and disk between different models were extremely significant (P < 0.01). CONCLUSIONS: With the same plane of occlusion, the stress distribution patterns of TMJ with different depth of CS is similar to that of normal occlusion. The final results also validate the anterior surface of condyle and intermediate zone of articular disc are the weight-bearing areas in TMJ. The changes of depth of CS change the value of the stress.


Assuntos
Côndilo Mandibular/fisiologia , Disco da Articulação Temporomandibular/fisiologia , Articulação Temporomandibular/fisiologia , Cefalometria , Oclusão Dentária , Análise do Estresse Dentário/métodos , Análise de Elementos Finitos , Humanos , Imageamento Tridimensional/métodos , Estresse Mecânico
19.
J Mol Biol ; 418(1-2): 90-102, 2012 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-22343047

RESUMO

Recently, the anticancer activity of human α-lactalbumin made lethal to tumor cells (HAMLET) has been linked to its increased membrane affinity in vitro, at neutral pH, and ability to cause leakage relative to the inactive native bovine α-lactalbumin (BLA) protein. In this study, atomic force microscopy resolved membrane distortions and annular oligomers (AOs) produced by HAMLET when deposited at neutral pH on mica together with a negatively charged lipid monolayer. BLA, BAMLET (HAMLET's bovine counterpart) and membrane-binding Peptide C, corresponding to BLA residues 75-100, also form AO-like structures under these conditions but at higher subphase concentrations than HAMLET. The N-terminal Peptide A, which binds to membranes at acidic but not at neutral pH, did not form AOs. This suggests a correlation between the capacity of the proteins/peptides to integrate into the membrane at neutral pH-as observed by liposome content leakage and circular dichroism experiments-and the formation of AOs, albeit at higher concentrations. Formation of AOs, which might be important to HAMLET's tumor toxic action, appears related to the increased tendency of the protein to populate intermediately folded states compared to the native protein, the formation of which is promoted by, but not uniquely dependent on, the oleic acid molecules associated with HAMLET.


Assuntos
Lactalbumina/química , Ácidos Oleicos/química , Fosfolipídeos/química , Polímeros/química , Lipossomas Unilamelares/química , Animais , Bovinos , Dicroísmo Circular , Humanos , Concentração de Íons de Hidrogênio , Microscopia de Força Atômica , Ácido Oleico/química , Dobramento de Proteína
20.
Chin Med J (Engl) ; 124(11): 1747-50, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21740791

RESUMO

Liquid injectable silicone has been used for soft tissue augmentation for five decades. Many complications following liquid silicone injection have been reported. To diagnose and manage silicone granuloma remains difficult. Silicone granuloma must be diagnosed with the history of liquid silicone injection and the histology of tissue biopsy. We presented a case of granulomatous reaction after the injection of liquid silicone for chin augmentation forty years ago, causing total facial swelling, which mimicking angioedema initially. We administered methylprednisolone to the patient. Initial response to methylprednisolone was favorable.


Assuntos
Angioedema/diagnóstico , Queixo/patologia , Técnicas Cosméticas/efeitos adversos , Granuloma/diagnóstico , Silicones/efeitos adversos , Idoso , Feminino , Humanos , Injeções Subcutâneas
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