Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Plant J ; 88(6): 936-946, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27460657

RESUMO

The sexine layer of pollen grain is mainly composed of sporopollenins. The sporophytic secretory tapetum is required for the biosynthesis of sporopollenin. Although several enzymes involved in sporopollenin biosynthesis have been reported, the regulatory mechanism of these enzymes in tapetal layer remains elusive. ABORTED MICROSPORES (AMS) and MALE STERILE 188/MYB103/MYB80 (MS188/MYB103/MYB80) are two tapetal cell-specific transcription factors required for pollen wall formation. AMS functions upstream of MS188. Here we report that AMS and MS188 target the CYP703A2 gene, which is involved in sporopollenin biosynthesis. We found that AMS and MS188 were localized in tapetum while CYP703A2 was localized in both tapetum and locule. Chromatin immunoprecipitation (ChIP) showed that MS188 directly bound to the promoter of CYP703A2 and luciferase-inducible assay showed that MS188 activated the expression of CYP703A2. Yeast two-hybrid and electrophoretic mobility shift assays (EMSAs) further demonstrated that MS188 complexed with AMS. The expression of CYP703A2 could be partially restored by the elevated levels of MS188 in the ams mutant. Therefore, our data reveal that MS188 coordinates with AMS to activate CYP703A2 in sporopollenin biosynthesis of plant tapetum.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Biopolímeros/biossíntese , Carotenoides/biossíntese , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Pólen/genética , Pólen/metabolismo , Fatores de Transcrição/genética
2.
Water Sci Technol ; 2017(1): 300-309, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29698244

RESUMO

This study prepared a carboxylate-functionalized sugarcane bagasse (CF-SCB) from sugarcane bagasse (SCB) via a simple and low-toxicity chemical modification to enhance its capacity for adsorbing methylene blue (MB) from aqueous solutions. The success of chemical modification was confirmed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), the pore area and porosity, and zeta potential measurement analysis. The adsorption capacity of CF-SCB was investigated at different pHs, ionic strengths, temperatures, contact times and initial dye concentrations. Equilibrium data were best described by the Langmuir isotherm model, and the maximum monolayer adsorption capacity of CF-SCB (296.74 mg g-1) was greatly improved compared with SCB (77.16 mg g-1) at 30 °C. The thermodynamic study indicated that MB adsorption onto CF-SCB was a spontaneous, endothermic and entropy increased process. Adsorption kinetics followed a pseudo-second-order mode, and the adsorption mechanism was based on electrostatic interactions. The reusability study showed that CF-SCB had reasonably good reuse potential. All the results suggested that CF-SCB has high potential to be used as an effective and renewable adsorbent for MB removal from wastewater.


Assuntos
Celulose/química , Azul de Metileno/química , Saccharum/química , Poluentes Químicos da Água/química , Adsorção , Cinética , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Tiazinas , Águas Residuárias , Purificação da Água
3.
Clin Orthop Relat Res ; 472(1): 162-8, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23884803

RESUMO

BACKGROUND: There is considerable debate about whether antibiotic-loaded bone cement should be used for fixation of TKAs. While antibiotics offer the theoretical benefit of lowering early revision due to infection, they may weaken the cement and thus increase the likelihood of aseptic loosening, perhaps resulting in a higher revision rate. QUESTIONS/PURPOSES: We (1) compared the frequency of early knee revision arthroplasty in patients treated with antibiotic-loaded or non-antibiotic-loaded cement for initial fixation, (2) determined effects of age, sex, comorbidities, and surgeons' antibiotic-loaded cement usage patterns on revision rate, and (3) compared causes of revision (aseptic or septic) between groups. METHODS: Our study sample was taken from the Canadian Joint Replacement Registry and Canada's Hospital Morbidity Database and included cemented TKAs performed between April 1, 2003, and March 31, 2008, including 20,016 TKAs inserted with non-antibiotic-loaded cement and 16,665 inserted with antibiotic-loaded cement. Chi-square test was used to compare the frequency of early revisions between groups. Cox regression modeling was used to determine whether revision rate would change by age, sex, comorbidities, or use of antibiotic-loaded cement. Similar Cox regression modeling was used to compare cause of revision between groups. RESULTS: Two-year revision rates were similar between the groups treated with non-antibiotic-loaded cement and antibiotic-loaded cement (1.40% versus 1.51%, p = 0.41). When controlling for age, sex, comorbidities, diabetes, and surgeons' antibiotic-loaded cement usage patterns, the revision risk likewise was similar between groups. Revision rates for infection were similar between groups; however, there were more revisions for aseptic loosening in the group treated with non-antibiotic-loaded cement (p = 0.02). CONCLUSIONS: The use of antibiotic-loaded cement in TKAs performed for osteoarthritis has no clinically significant effect on reducing revision within 2 years in patients who received perioperative antibiotics. Longer followup and confirmation of these findings with other national registries are warranted.


Assuntos
Antibacterianos/uso terapêutico , Artroplastia do Joelho/métodos , Cimentos Ósseos , Articulação do Joelho/cirurgia , Osteoartrite do Joelho/cirurgia , Infecções Relacionadas à Prótese/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infecções Relacionadas à Prótese/tratamento farmacológico , Sistema de Registros , Reoperação , Estudos Retrospectivos , Resultado do Tratamento
4.
PLoS Negl Trop Dis ; 18(7): e0012008, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38949988

RESUMO

BACKGROUND: Hand, foot, and mouth disease (HFMD) is a major public health issue in China while temperature and humidity are well-documented predictors. However, evidence on the combined effect of temperature and humidity is still limited. It also remains unclear whether such an effect could be modified by the enterovirus 71 (EV71) vaccination. METHODS: Based on 320,042 reported HFMD cases during the summer months between 2012 and 2019, we conducted a study utilizing Distributed Lag Non-Linear Models (DLNM) and time-varying DLNM to examine how China's HFMD EV71 vaccine strategy would affect the correlation between meteorological conditions and HFMD risk. RESULTS: The incidence of HFMD changed with the Discomfort Index in an arm-shaped form. The 14-day cumulative risk of HFMD exhibited a statistically significant increase during the period of 2017-2019 (following the implementation of the EV71 vaccine policy) compared to 2012-2016 (prior to the vaccine implementation). For the total population, the range of relative risk (RR) values for HFMD at the 75th, 90th, and 99th percentiles increased from 1.082-1.303 in 2012-2016 to 1.836-2.022 in 2017-2019. In the stratified analyses, Han Chinese areas show stronger relative growth, with RR values at the 75th, 90th, and 99th percentiles increased by 14.3%, 39.1%, and 134.4% post-vaccination, compared to increases of 22.7%, 41.6%, and 38.8% in minority areas. Similarly, boys showed greater increases (24.4%, 47.7%, 121.5%) compared to girls (8.1%, 28.1%, 58.3%). Additionally, the central Guizhou urban agglomeration displayed a tendency for stronger relative growth compared to other counties. CONCLUSIONS: Although the EV71 vaccine policy has been implemented, it hasn't effectively controlled the overall risk of HFMD. There's been a shift in the main viral subtypes, potentially altering population susceptibility and influencing HFMD occurrences. The modulating effects of vaccine intervention may also be influenced by factors such as race, sex, and economic level.


Assuntos
Enterovirus Humano A , Doença de Mão, Pé e Boca , Vacinação , Doença de Mão, Pé e Boca/epidemiologia , Doença de Mão, Pé e Boca/prevenção & controle , Humanos , China/epidemiologia , Masculino , Feminino , Vacinação/estatística & dados numéricos , Lactente , Pré-Escolar , Enterovirus Humano A/imunologia , Incidência , Vacinas Virais/administração & dosagem , Umidade , Temperatura , Criança
5.
BMC Infect Dis ; 13: 134, 2013 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-23497074

RESUMO

BACKGROUND: Over the last decade, major outbreaks of hand, foot, and mouth disease (HFMD) have been reported in Asian countries, resulting in thousands of deaths among children. However, less is known regarding the effect of meteorological variables on the incidence of HFMD in children. This study aims at quantifying the relationship between meteorological variables and the incidence of HFMD among children in Guangzhou, China. METHODS: The association between weekly HFMD cases in children aged <15 years and meteorological variables in Guangzhou from 2008 to 2011 were analyzed using the generalized additive model (GAM) and time-series method, after controlling for long-term trend and seasonality, holiday effects, influenza period and delayed effects. RESULTS: Temperature and relative humidity with one week lag were significantly associated with HFMD infection among children. We found that a 1°C increase in temperature led to an increase of 1.86% (95% CI: 0.92, 2.81%) in the weekly number of cases in the 0-14 years age group. A one percent increase in relative humidity may lead to an increase of 1.42% (95% CI: 0.97, 1.87%) in the weekly number of cases in the 0-14 years age group. CONCLUSIONS: This study provides quantitative evidence that the incidence of HFMD in children was associated with high average temperature and high relative humidity. The one-week delay in the effects of temperature and relative humidity on HFMD is consistent with the enterovirus incubation period and the potential time lag between onset of children's sickness and parental awareness and response.


Assuntos
Clima , Doença de Mão, Pé e Boca/epidemiologia , Adolescente , Criança , Pré-Escolar , China/epidemiologia , Feminino , Humanos , Umidade , Incidência , Lactente , Recém-Nascido , Masculino , Estações do Ano , Temperatura
6.
Artigo em Inglês | MEDLINE | ID: mdl-36901058

RESUMO

The transformation of waste plastics into fuels via energy-efficient and low-cost pyrolysis could incentivize better waste plastic management. Here, we report pressure-induced phase transitions in polyethylene, which continue to heat up without additional heat sources, prompting the thermal cracking of plastics into premium fuel products. When the nitrogen initial pressure is increased from 2 to 21 bar, a monotonically increasing peak temperature is observed (from 428.1 °C to 476.7 °C). At 21 bar pressure under different atmosphere conditions, the temperature change driven by high-pressure helium is lower than that driven by nitrogen or argon, indicating that phase transition is related to the interaction between long-chain hydrocarbons and intercalated high-pressure medium layers. In view of the high cost of high-pressure inert gases, the promotion or inhibition effect of low-boiling hydrocarbons (transitioning into the gaseous state with increasing temperature) on phase transition is explored, and a series of light components are used as phase transition initiators to replace high-pressure inert gases to experiment. The reason that the quantitative conversion of polyethylene to high-quality fuel products is realized through the addition of 1-hexene at a set temperature of 340 °C and the initial atmospheric pressure. This discovery provides a method for recycling plastics by low energy pyrolysis. In addition, we envisage recovering some of the light components after plastic pyrolysis as phase change initiators for the next batch of the process. This method is able to reduce the cost of light hydrocarbons or high-pressure gas insertion, reduce heat input, and improve material and energy utilization.


Assuntos
Óleos Combustíveis , Polietileno , Eliminação de Resíduos , Pressão Atmosférica , Hidrocarbonetos , Nitrogênio , Plásticos , Temperatura , Eliminação de Resíduos/métodos , Reciclagem/métodos
7.
Waste Manag ; 135: 140-149, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34507185

RESUMO

In the present research, a series of metal oxides were employed to investigate the role of varied acid-base site on kinetics and mechanism for catalytic fast pyrolysis of cellulose using TG-MS and Py-GC/MS. The results showed that the modulation of acidity-to-basicity value via altering metal oxides constituents significantly affected the transformation pathway for cellulose pyrolysis. Higher acidity-to-basicity ratios accelerated the proceeding of deoxygenation process, wherein 39.4% aromatics and 34.7% aliphatic hydrocarbons were achieved using Al2O3 (acidity-to-basicity value of 1.38) at 750 °C with a catalyst/cellulose mass ratio of 15:1. In comparison, lowering acidity-to-basicity ratios mainly facilitated the ketonization and aldol condensation, therefore over 70% ketones was attained in the case of CaO catalysis. The kinetic studies further verified the promotional role of acid-base sites on cellulose pyrolysis with apparent activation energy as low as 33.72 kJ/mol, in comparison with that of cellulose pyrolysis without adding catalysts. From another aspect, the composite metal oxides with better porous structures contributed to deoxygenation conversion for the production of aromatics and aliphatic hydrocarbons. Moreover, plausible reaction pathway for cellulose pyrolysis over metal oxides was proposed. This work would provide a good reference for the realization of product regulation from cellulose pyrolysis via adjusting acid-base sites in metal oxides.


Assuntos
Celulose , Pirólise , Biomassa , Catálise , Temperatura Alta , Cinética , Óxidos
8.
Waste Manag ; 121: 255-264, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33388648

RESUMO

Potassium is an inorganic mineral element in biomass and has a significant catalytic effect on biomass pyrolysis. In this work, the effect of potassium on the pyrolysis of biomass components (cellulose, xylan and lignin) was investigated with the help of thermogravimetric analyzer coupled to fourier transform infrared spectrometer (TG-FTIR) and pyrolysis-gas chromatography coupled to mass spectrometry (Py-GC/MS). The results showed that potassium accelerated the start of the main pyrolysis stage of the biomass components, reduced the weight loss rate for cellulose and lignin, and increased the weight loss rate for xylan. On the other hand, potassium presented a promotion effect on the formation of char for cellulose but a suppression effect for lignin. In addition, an increasing potassium content promoted the release of volatile products for xylan. Product distribution analysis found that potassium promoted the scission of glycosidic bonds and the decomposition of glucose units, resulting in a sharp yield decrease of carbohydrates and a yield increase of furans, aldehydes and ketones. In addition, an increased production of CO2 was obtained, indicating that potassium favors the cleavage and reforming of carboxyl (COOH) and carbonyl (CO) groups. Furthermore, the effect of potassium on the pyrolysis of cellulose and xylan was stronger than that on lignin pyrolysis. The effect on the pyrolysis reaction also resulted in a higher activation energy for the decomposition of biomass components, especially at high temperature intervals. Moreover, the higher the content of potassium added, the greater the increase was in the activation energy.


Assuntos
Potássio , Pirólise , Biomassa , Celulose , Temperatura Alta , Lignina , Termogravimetria
9.
Gels ; 7(3)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34449604

RESUMO

Tooth loss has been found to adversely affect not just masticatory and speech functions, but also psychological health and quality of life. Currently, teeth replacement options include dentures, bridges, and implants. However, these artificial replacement options remain inferior to biological replacements due to their reduced efficiency, the need for replacements, and the risk of immunological rejection. To this end, there has been a heightened interest in the bioengineering of teeth in recent years. While there have been reports of successfully regenerated teeth, controlling the size and shape of bioengineered teeth remains a challenge. In this study, methacrylated hyaluronic acid (MeHA) was synthesized and microstructured in a hydrogel microwell array using soft lithography. The resulting MeHA hydrogel microwell scaffold resembles the shape of a naturally developing human tooth germ. To facilitate the epithelial-mesenchymal interactions, human adult low calcium high temperature (HaCaT) cells were seeded on the surface of the hydrogels and dental pulp stem cells (DPSCs) were encapsulated inside the hydrogels. It was found that hydrogel scaffolds were able to preserve the viability of both types of cells and they appeared to favor signaling between epithelial and mesenchymal cells, which is necessary in the promotion of cell proliferation. As such, the hydrogel scaffolds offer a promising system for the bioengineering of human tooth germs in vitro.

10.
Nanoscale ; 12(22): 12083-12097, 2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-32478361

RESUMO

Highly effective and safe delivery of therapeutic enzymes is pivotal to the success of antitumor therapy. Herein, we report on a targeted enzyme delivery system based on cytomembrane-mimicking nanocarriers (CmN) and a supramolecular technique (SmT). Specifically, each CmN had a scaffold that mainly consisted of a CD44-targeted endogenous component conjugated with polyethylene glycol 2000 (HA-g-PEG) that self-assembled with α-cyclodextrin (ACD). The CmN acted as a microbioreactor with an inner hollow space with the capacity to confine the large molecule asparaginase (Asp) in an Asp/ACD-supramolecular complex conjugated to the inner region. The supramolecular Asp loaded into the CmN (A-S-CmN) exhibited superior stability, kinetic properties, catalytic activity and antitumor effects compared to free Asp due to the dual protection of the supramolecular complex and the nanovesicle, the CD44 targeting-homing ability, the prolonged effects of HA-g-PEG, and the favorable inner microenvironment of the constructed supramolecular CmN. The A-S-CmN also showed a decrease in in vivo toxicity and immunogenicity. CmN combined with SmT therapeutics are easy to implement and extend for use in the delivery of various enzymes and for many types of cancer treatment.


Assuntos
Asparaginase , Polietilenoglicóis , Ácido Hialurônico
11.
ACS Appl Mater Interfaces ; 12(28): 31112-31123, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32544316

RESUMO

Platforms for enzyme delivery must simultaneously have plasma stability, high catalytic activity, and low/no immunogenicity of the enzyme. Here, we designed a novel biomimetic membrane-structured nanovesicle (BNV) to efficiently carry supramolecular enzymes to meet the above requirements. We complexed l-asparaginase (Aase) with hydroxypropyl-ß-cyclodextrin (HPCD) to form a supramolecular amphiphile (AS) by self-assembly via noncovalent reversible interactions. We then used the first synthesized polyethylene glycol (PEG 2 kDa)-decorated hyaluronan (12 kDa) and HPCD to self-assemble a semipermeable biomimetic membrane-structured nanovesicle (BNV) together with AS loading. As compared to native Aase, AS@BNV exhibited superior catalytic activity preservation, improved catalytic activity, better pharmacokinetics in rats, enhanced cytotoxic effects, increased antitumor efficacy, and decreased side effects. The underlying mechanisms, such as the autophagy inhibition action against tumor cells, protein-protein docking of the interaction between Aase-serum albumin, and decreased hepatic enzymatic activity, were investigated. This approach paves the way for new types of powerful biomimetic-, supramolecular-, and nanocarrier-based enzymatic therapies.


Assuntos
Biomimética/métodos , beta-Ciclodextrinas/química , Animais , Antineoplásicos/química , Asparaginase/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Concentração de Íons de Hidrogênio , Neoplasias Pulmonares/enzimologia , Polietilenoglicóis/química , Ratos
12.
Int J Bioprint ; 5(2.1): 203, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32596543

RESUMO

Topical anesthetics are widely used in dental procedures. However, most commercially available medications are in the form of liquid or semisolid, which cannot provide prolonged effect intraorally. To address this issue, we proposed the use of three-dimensional printing (3DP) to fabricate a customizable dental anesthetic patch loaded with lidocaine that can be fitted perfectly onto the affected tooth. It has been shown that that patch can adhere on the tooth for more than 1 h, while releasing lidocaine from the patch made of hydrogels. In addition, the results illustrated the possibility of controlling the drug release profile by altering the shape of the patch, as well the use of a 3DP tooth model as the drug testing platform. Taken together, these data further reinforce the vast potential of the application of 3DP technology in personalized medicine.

13.
Biosens Bioelectron ; 87: 858-864, 2017 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-27657848

RESUMO

Core-shell structural adenosine-imprinted microspheres were prepared via a two-step procedure. Polystyrene core particles (CP) were firstly prepared via a reversible addition-fragmentation chain transfer (RAFT) polymerization leaving the iniferter on the surface of the cores, then a molecularly imprinted polymer (MIP) shell was synthesized on the surface of the cores by using acrylamide (AAm) as the functional monomer and ethylene glycol dimethacrylate (EGDMA) as the cross-linker. The formation and growth of the MIP layer were seen dependent on the initiator (AIBN), AAm and the polymerization time used within the polymerization. SEM/TEM images showed that the dimensions of the cores and shells were 2µM and 44nm, respectively. The MIP microspheres exhibited a fast rebinding rate within 2h and a maximum adsorption capacity of 177µg per gram for adenosine. The adsorption fitted a Langmuir-Freundlich (LF) isotherm model with a KLF value of 41mL/µg and a qm value of 177µg/g for the MIP microspheres. The values were larger than those for a non-molecularly imprinted polymer (NIP) particles (5mL/µg and 88µg/g) indicating a better adsorption ability towards adenosine. The MIP microspheres showed a good selectivity for adenosine with a higher adsorption (683nmol/g) for adenosine than that (91nmol/g, 24nmol/g and 54nmol/g) for guanosine, cytidine and uridine respectively. Further experiment proved that the adenosine-imprinted polymer microspheres also had a good selectivity for ADP-ribosylated proteins that the MIP could extract the ADP-ribosylated proteins from the cell extract samples.


Assuntos
Difosfato de Adenosina/análise , Adenosina/análise , Impressão Molecular/métodos , Polímeros/química , Proteínas/química , Adenosina/isolamento & purificação , Difosfato de Adenosina/isolamento & purificação , Animais , Técnicas Biossensoriais , Bovinos , Gliceraldeído-3-Fosfato Desidrogenase (Fosforiladora)/química , Microesferas , Polimerização , Poliestirenos/química , Soroalbumina Bovina/química
14.
J Endod ; 43(11): 1821-1827, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28864219

RESUMO

INTRODUCTION: The aim of the study was to compare the outcomes of regenerative endodontic treatment (RET) and apexification on immature permanent teeth with pulp necrosis and apical periodontitis. METHODS: A total of 118 patients (118 teeth) were recruited and randomly assigned to either RET or apexification treatment. Each treatment group was divided into 2 subgroups according to the etiology: dens evaginatus or trauma. Clinical symptoms and complications were recorded, and cone-beam computed tomographic imaging with a limited field of view was used to measure the change of root length, root thickness, and apical foramen size at the 12-month follow-up. The t test/rank sum test and Fisher exact test were applied to compare the change of root morphology between RET and apexification. RESULTS: One hundred three of 118 cases were completed at the 12-month follow-up. The survival rate was 100% for both treatment groups. All cases were asymptomatic with apical healing. The RET group showed a significant increase in root length and root thickness compared with the apexification group (P < .05). In the RET group, the cases caused by dens evaginatus achieved increased root length and root thickness compared with those caused by trauma (P < .05). CONCLUSIONS: RET and apexification achieved a comparable outcome in regard to the resolution of symptoms and apical healing. RET showed a better outcome than apexification regarding increased root thickness and root length. The etiology had an impact on the outcome of RET. Dens evaginatus cases showed better prognoses than trauma cases after RET.


Assuntos
Apexificação , Polpa Dentária/fisiologia , Periodontite Periapical/cirurgia , Engenharia Tecidual/métodos , Adolescente , Apexificação/métodos , Criança , Necrose da Polpa Dentária/cirurgia , Humanos , Estudos Prospectivos , Regeneração
15.
Exp Mol Med ; 48: e223, 2016 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-27012709

RESUMO

Periodontitis is a common chronic inflammatory disease. Recent studies have shown that chronic stress (CS) might modulate periodontal disease, but there are few models of CS-induced periodontitis, and the underlying mechanisms are unclear. The present study established a rat model of periodontitis associated with CS induced by nylon thread ligatures. The severity of periodontitis was evaluated in this model by radiographic and pathological examination. The inflammatory reaction indicated by the elevated serum levels of interleukin (IL)-1ß, IL-6 and IL-8 was assessed by enzyme-linked immunosorbent assay. Toll-like receptor-4 (TLR4) and glucocorticoid receptor-α (GR-α) expressions were detected by reverse transcriptase-PCR and western blotting. Open-field tests and serum corticosterone were used to evaluate CS. The results showed that CS induced behavioral changes and increased corticosterone levels of the animals with periodontitis. CS stimulation markedly increased alveolar bone loss, periodontal pocket depth and the number of plaques. It also enhanced the inflammatory reaction. These results suggest that CS accelerated the ligature-induced pathological changes associated with periodontitis. Further analysis of the mechanisms involved showed that GR-α expression was significantly downregulated in periodontal tissues of the animals undergoing CS. Blocking GR-α signaling in lipopolysaccharide and corticosteroid-treated human periodontal ligament fibroblast cells in vitro significantly upregulated the expression of p-Akt (protein kinase B) and TLR4, promoted nuclear factor-κB activity and increased levels of IL-1ß, IL-6 and IL-8. This research suggests that CS might accelerate the pathological progression of periodontitis by a GR-α signaling-mediated inflammatory response and that this may be a potential therapeutic target for the treatment of periodontal disease, particularly in patients with CS.


Assuntos
Periodontite/etiologia , Periodontite/metabolismo , Receptores de Glucocorticoides/metabolismo , Estresse Fisiológico , Estresse Psicológico , Animais , Modelos Animais de Doenças , Progressão da Doença , Expressão Gênica , Lipopolissacarídeos/imunologia , Masculino , NF-kappa B/metabolismo , Periodontite/patologia , Ratos , Receptores de Glucocorticoides/genética
16.
Exp Mol Med ; 46: e118, 2014 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-25323788

RESUMO

This study assessed the roles of chronic stress (CS) in the stimulation of the sympathetic nervous system and explored the underlying mechanisms of periodontitis. Using an animal model of periodontitis and CS, the expression of tyrosine hydroxylase (TH) and the protein levels of the α1-adrenergic receptor (α1-AR) and ß2-adrenergic receptor (ß2-AR) were assessed. Furthermore, human periodontal ligament fibroblasts (HPDLFs) were stimulated with lipopolysaccharide (LPS) to mimic the process of inflammation. The proliferation of the HPDLFs and the expression of α1-AR and ß2-AR were assessed. The inflammatory-related cytokines interleukin (IL)-1ß, IL-6 and IL-8 were detected after pretreatment with the α1/ß2-AR blockers phentolamine/propranolol, both in vitro and in vivo. Results show that periodontitis under CS conditions enhanced the expression of TH, α1-AR and ß2-AR. Phentolamine significantly reduced the inflammatory cytokine levels. Furthermore, we observed a marked decrease in HPDLF proliferation and the increased expression of α1-ARfollowing LPS pretreatment. Pretreatment with phentolamine dramatically ameliorated LPS-inhibited cell proliferation. In addition, the blocking of α1-ARsignaling also hindered the upregulation of the inflammatory-related cytokines IL-1ß, IL-6 and IL-8. These results suggest that CS can significantly enhance the pathological progression of periodontitis by an α1-adrenergic signaling-mediated inflammatory response. We have identified a potential therapeutic target for the treatment of periodontal disease, particularly in those patients suffering from concurrent CS.


Assuntos
Antagonistas de Receptores Adrenérgicos alfa 1/uso terapêutico , Periodontite/tratamento farmacológico , Periodontite/etiologia , Fentolamina/uso terapêutico , Receptores Adrenérgicos alfa 1/imunologia , Estresse Fisiológico , Animais , Células Cultivadas , Citocinas/imunologia , Fibroblastos/imunologia , Fibroblastos/patologia , Humanos , Lipopolissacarídeos/administração & dosagem , Lipopolissacarídeos/imunologia , Masculino , Ligamento Periodontal/citologia , Ligamento Periodontal/imunologia , Ligamento Periodontal/patologia , Periodontite/imunologia , Periodontite/patologia , Ratos , Ratos Wistar , Receptores Adrenérgicos alfa 1/análise , Transdução de Sinais/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , Tirosina 3-Mono-Oxigenase/análise , Tirosina 3-Mono-Oxigenase/imunologia
17.
PLoS One ; 8(2): e56943, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23437278

RESUMO

OBJECTIVE: Hand, foot, and mouth disease (HFMD) has posed a great threat to the health of children and become a public health priority in China. This study aims to investigate the epidemiological characteristics, spatial-temporal patterns, and risk factors of HFMD in Guangdong Province, China, and to provide scientific information for public health responses and interventions. METHODS: HFMD surveillance data from May 2008 to December 2011were provided by the Chinese Center for Disease Control and Prevention. We firstly conducted a descriptive analysis to evaluate the epidemic characteristics of HFMD. Then, Kulldorff scan statistic based on a discrete Poisson model was used to detect spatial-temporal clusters. Finally, a spatial paneled model was applied to identify the risk factors. RESULTS: A total of 641,318 HFMD cases were reported in Guangdong Province during the study period (total population incidence: 17.51 per 10,000). Male incidence was higher than female incidence for all age groups, and approximately 90% of the cases were children [Formula: see text] years old. Spatial-temporal cluster analysis detected four most likely clusters and several secondary clusters (P<0.001) with the maximum cluster size 50% and 20% respectively during 2008-2011. Monthly average temperature, relative humidity, the proportion of population [Formula: see text] years, male-to-female ratio, and total sunshine were demonstrated to be the risk factors for HFMD. CONCLUSION: Children [Formula: see text] years old, especially boys, were more susceptible to HFMD and we should take care of their vulnerability. Provincial capital city Guangzhou and the Pearl River Delta regions had always been the spatial-temporal clusters and future public health planning and resource allocation should be focused on these areas. Furthermore, our findings showed a strong association between HFMD and meteorological factors, which may assist in predicting HFMD incidence.


Assuntos
Doença de Mão, Pé e Boca/epidemiologia , Análise Espaço-Temporal , Criança , Pré-Escolar , China/epidemiologia , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Vigilância em Saúde Pública , Fatores de Risco , Estações do Ano , Topografia Médica
18.
Shanghai Kou Qiang Yi Xue ; 19(3): 225-7, 2010 Jun.
Artigo em Zh | MEDLINE | ID: mdl-20635027

RESUMO

PURPOSE: To evaluate the effect of periodontal initial therapy on clinical parameters and subgingival periodontal pathogen in patients with chronic periodontitis. METHODS: One hundred and twenty patients with chronic periodontitis were included. Probing depth (PD), attachment loss (AL), plaque index (PLI) and gingival index (GI) were evaluated at baseline and after-initial therapy. P.g and A.a in subgingival plaque were investigated by real-time PCR. Data was statistically analyzed by SAS6.12 software for Student's t test. RESULTS: The PD, AL, PLI and GI were significantly decreased after periodontal initial therapy (P<0.01), and meanwhile the ratio of P.g versus total bacteria was significantly decreased after-initial therapy (P<0.05). However, the change of ratio of A.a versus total bacteria was not significant (P>0.05). CONCLUSION: Periodontal initial therapy could effectively control the inflammation of chronic periodontitis, and decrease the ratio of P.g in subgingival plaque.


Assuntos
Periodontite Crônica , Perda da Inserção Periodontal , Placa Dentária , Índice de Placa Dentária , Humanos , Índice Periodontal , Bolsa Periodontal , Periodontite
19.
Shanghai Kou Qiang Yi Xue ; 15(6): 585-90, 2006 Dec.
Artigo em Zh | MEDLINE | ID: mdl-17533708

RESUMO

PURPOSE: To investigate and analyze the state of periodontal health of 400 adults at their post and risk factors in Shanghai. METHODS: 400 subjects (249 male, 151 female), aged from 25 to 59, were requested to fill a questionnaire. The probing depth (PD), clinical attachment level (CAL), tooth mobility (TM) and bleeding on probing(BOP) on 6 sites of each indicated tooth were measured and recorded. SAS 6.12 software package was used for statistical analysis. RESULTS: OHI-S of Shanghai adults at their post was 2.16 +/- 0.99 and GI = 1.2227, indicating moderate gingivitis. The difference of periodontal disease among the adults at varied occupations in Shanghai municipality was significant. Periodontal destruction of the clerk group was the lightest The difference of periodontal disease among the adults at varied age groups in Shanghai municipality was also significant. Periodontal destruction of the elder group was heavier than of the lower age group. 146 subjects suffered from initial to moderate periodontitis. 140 subjects suffered from advanced periodontitis. 79, 317 and 4 subjects had received college education, high school education and postgraduate school education respectively. There was no relationship between the severity of periodontitis and educational level. 330 out of 400 (82.5%) subjects had never been treated, 70 out of 400 (12.5%) had scaling,and only 3.25% of subjects had received regular periodontal treatment. CONCLUSION: It is very important to develop an education program on oral health for people in Shanghai. Supported by National "Tenth Five-Year" Key Project (Grant No.2004BA720A26), Research Fund of the Science and Technology Committee of Shanghai Municipality (Grant No.0352nm126) and Shanghai Leading Academic Discipline Project(Grant No.94-III-008).


Assuntos
Higiene Bucal/estatística & dados numéricos , Doenças Periodontais/epidemiologia , Periodontite/epidemiologia , Adulto , China/epidemiologia , Feminino , Gengivite , Humanos , Masculino , Pessoa de Meia-Idade , Higiene Bucal/educação , Perda da Inserção Periodontal , Fatores de Risco , Estudos de Amostragem , Fatores Socioeconômicos , Inquéritos e Questionários , População Urbana
20.
Shanghai Kou Qiang Yi Xue ; 14(5): 449-51, 2005 Oct.
Artigo em Zh | MEDLINE | ID: mdl-16288318

RESUMO

PURPOSE: To evaluate the relationship between the calcaneus density and the degree of inflammation in patients with generalized aggressive periodontitis. METHODS: Thirty one volunteers with healthy periodontium (as control group) and 38 patients with generalized aggressive periodontitis (as experimental group) were involved in this study. The average ages of the two groups were 27 and 23 years respectively. The clinical periodontal indexes and panoramic films were measured first. And the broadband ultrasonic attenuation(BUA) and T-score of the calcaneus were then determined using ultrasonic bone densitometer. SAS6.12 software package was used to analyse the data obtained. RESULTS: The BUA values of the two groups were 62.76+/-4.61 and 70.47+/-4.41 respectively, the BUA value of the experimental group was significantly lower than that of the control group (P<0.001). Moreover, T-score was different between the two groups and the score in the experimental group was significantly lower than that in the control (P<0.001). CONCLUSIONS: The BUA and T-score in patients with generalized aggressive periodontitis were significantly lower than that in the controls with healthy periodontium, which indicated that patients with generalized aggressive periodontitis had overall bone density decrease.


Assuntos
Periodontite Agressiva , Densidade Óssea , Absorciometria de Fóton , Calcâneo , Humanos , Inflamação , Periodonto
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA