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1.
Nat Commun ; 11(1): 5459, 2020 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-33122649

RESUMO

Biocontainment systems are needed to neutralize genetically modified organisms (GMOs) that pose ecological threats outside of controlled environments. In contrast, benign selection markers complement GMOs with reduced fitness. Benign selection agents serve as alternatives to antibiotics, which are costly and risk spread of antibiotic resistance. Here, we present a yeast biocontainment strategy leveraging engineered fluoride sensitivity and DNA vectors enabling use of fluoride as a selection agent. The biocontainment system addresses the scarcity of platforms available for yeast despite their prevalent use in industry and academia. In the absence of fluoride, the biocontainment strain exhibits phenotypes nearly identical to those of the wildtype strain. Low fluoride concentrations severely inhibit biocontainment strain growth, which is restored upon introduction of fluoride-based vectors. The biocontainment strategy is stringent, easily implemented, and applicable to several eukaryotes. Further, the DNA vectors enable genetic engineering at reduced costs and eliminate risks of propagating antibiotic resistance.


Assuntos
Fluoretos , Proteínas de Membrana/genética , Organismos Geneticamente Modificados/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Seleção Genética , Fluoretos/metabolismo , Fluoretos/farmacologia , Engenharia Genética , Marcadores Genéticos , Saccharomyces cerevisiae/efeitos dos fármacos , Biologia Sintética/métodos
2.
Chemosphere ; 260: 127565, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32758781

RESUMO

The effects of fluoride on endocrine tissues has not been sufficiently explored to date. The current body of knowledge suggest significant effects of that mineral on reducing sex hormone levels, which may consequently impair fertility and disrupt puberty. The majority of studies confirm that sodium fluoride increases TSH levels and decreases the concentrations of T3 and T4 produced by the thyroid. Moreover, a correlation was observed between NaF and increased secretion of PTH by the parathyroid glands, without a significant impact on body calcium levels. Probably, fluoride may exert adverse effects on insulin levels, impairing pancreatic function and resulting in abnormal glucose tolerance. Observations also include decreased levels of cortisol secreted by the adrenal glands. In light of the few existing studies, the mechanism of fluoride toxicity on the endocrine system has been described.


Assuntos
Sistema Endócrino/efeitos dos fármacos , Fluoretos/farmacologia , Glândulas Suprarrenais/metabolismo , Animais , Fluoretos/efeitos adversos , Fluoretos/toxicidade , Humanos , Hidrocortisona/metabolismo , Insulina/análise , Glândulas Paratireoides/efeitos dos fármacos , Glândulas Paratireoides/metabolismo , Fluoreto de Sódio/farmacologia , Fluoreto de Sódio/toxicidade , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/metabolismo , Hormônios Tireóideos/metabolismo
3.
Int J Nanomedicine ; 15: 2829-2839, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32368057

RESUMO

Objective: To investigate the remineralizing and staining effects of sodium fluoride (NaF) solution with polyethylene glycol-coated silver nanoparticles (PEG-AgNPs) on artificial dentine caries. Materials and Methods: Demineralized human dentine blocks were allocated to three groups. The blocks in group 1 underwent a topical application of a 12% silver diamine fluoride (SDF, 14,150 ppm fluoride) solution. The blocks in group 2 received a topical application of a 2.5% NaF (11,310 ppm fluoride) with PEG-AgNPs (400 ppm silver). The blocks in group 3 received deionized water. All blocks were subjected to pH cycling for 8 days. The surface morphology and cross-sectional features were investigated using scanning electron microscopy (SEM). The color parameters, crystal characteristics, lesion depth, and collagen degradation of the blocks were assessed using digital spectrophotometry, X-ray diffraction (XRD), micro-computed tomography, and spectrophotometry with a hydroxyproline assay, respectively. Results: The SEM showed that dentine collagen was exposed in group 3 but not in groups 1 and 2. The mean lesion depths in groups 1 to 3 were 118±7 µm, 121±14 µm, and 339±20 µm, respectively (groups1,2<3; p<0.001). The data indicated that fluoridated PEG-AgNPs introduced no significant color effect on dentine, but SDF caused distinct discoloration. The XRD indicated that silver chloride was formed in group 1, and fluorapatite was detected in groups 1 and 2. The concentration of hydroxyproline liberated from collagen was significantly less in groups 1 and 2 than in group 3. Conclusion: The use of NaF solution with PEG-AgNPs can remineralize artificial dentine caries and inhibit collagen degradation without causing significant tooth staining.


Assuntos
Cárie Dentária/tratamento farmacológico , Dentina/efeitos dos fármacos , Nanopartículas Metálicas/uso terapêutico , Fluoreto de Sódio/farmacologia , Remineralização Dentária/métodos , Colágeno , Cor , Dentina/metabolismo , Dentina/patologia , Fluoretos/farmacologia , Fluoretos Tópicos/química , Fluoretos Tópicos/farmacologia , Humanos , Hidroxiprolina/metabolismo , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Microscopia Eletrônica de Varredura , Dente Serotino/efeitos dos fármacos , Dente Serotino/patologia , Dente Serotino/ultraestrutura , Polietilenoglicóis/química , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/farmacologia , Prata , Compostos de Prata/química , Compostos de Prata/farmacologia , Fluoreto de Sódio/administração & dosagem , Difração de Raios X , Microtomografia por Raio-X
4.
Chemosphere ; 243: 125451, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31995892

RESUMO

Excessive and inadequate intake of fluoride may cause adverse effects in children, such as dental caries and dental fluorosis. This study reports the results of monitoring fluoride concentrations in drinking water from an endemic fluorosis region during the ten-year period (2008 through 2017). The fluoride concentration had a range of 0.03-9.42 mg L-1 (mean = 0.55 ± 0.01 mg L-1). Approximately 10%, 1.3% and 0.06% children are at risk for dental decay, dental fluorosis and skeletal fluorosis, respectively. Probabilistic risks for children were assessed and the fluoride endemic areas were marked by GIS mapping system. On several water consumption points, the hazard quotient (HQ) values for children were higher than 1, indicating potential non-cancer health risks due to fluoride exposure. The results of this study will help governmental agencies to develop better policies for protecting children from exposure to fluoride.


Assuntos
Água Potável/normas , Fluoretos/farmacologia , Fluorose Dentária/etiologia , Abastecimento de Água/normas , Criança , China/epidemiologia , Cárie Dentária/prevenção & controle , Água Potável/efeitos adversos , Fluoretos/análise , Fluorose Dentária/epidemiologia , Humanos , Minerais , Prevalência
5.
Environ Toxicol ; 35(2): 242-253, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31710167

RESUMO

Fluoride is an environmental contaminant that is ubiquitously present in air, water, and soil. It is commonly added in minute quantity to drinking water, toothpaste, and mouth rinses to prevent tooth decay. Epidemiological findings have demonstrated that exposure to fluoride induced neurodevelopmental toxicity, developmental neurotoxicity, and motor disorders. The neuroprotective effect of clofibrate, a peroxisome proliferator-activated receptor alpha agonist, was investigated in the present study. Forty male Wistar rats were used for this study and randomly grouped into 10 rats per group as control, sodium fluoride (NaF) alone (300 ppm), NaF plus clofibrate (250 mg/kg), and NaF plus lisinopril (10 mg/kg), respectively, for 7 days. NaF was administered in drinking water while clofibrate and lisinopril were administered by oral gavage. Markers of neuronal inflammation and oxidative stress, acetylcholinesterase activity, and neurobehavioral (hanging wire and open field) tests were performed. Immunohistochemistry was performed on brain tissues, and they were probed with glial fibrillary acidic protein, ionized calcium-binding adaptor molecule 1, and cerebellar Ca2+ -binding protein calbindin-D28k. The results showed that NaF significantly increased of oxidative stress and neuroinflammation and inhibited AChE activity. Immunostaining showed reactive astrocytes, microgliosis, loss of dendritic spines, and arborization in Purkinje cells in rats administered only NaF. Neurobehavioral results showed that cotreatment of NaF with clofibrate improved muscular strength and locomotion, reduced anxiety, and significantly reduced astrocytic count. Overall, cotreatment of NaF with either clofibrate or lisinopril showed neuroprotective effects by mitigating neuronal inflammation and oxidative and motor incoordination. Hence, clofibrate could be seen as a novel drug candidate against neurodegeneration and motor disorders.


Assuntos
Ataxia/prevenção & controle , Calbindinas/antagonistas & inibidores , Proteínas de Ligação ao Cálcio/metabolismo , Clofibrato/farmacologia , Proteína Glial Fibrilar Ácida/metabolismo , Proteínas dos Microfilamentos/metabolismo , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , PPAR alfa/agonistas , Fluoreto de Sódio/toxicidade , Animais , Ataxia/imunologia , Biomarcadores/metabolismo , Fluoretos/farmacologia , Inflamação , Masculino , Distribuição Aleatória , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos
6.
Nanotechnology ; 31(14): 145101, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-31846954

RESUMO

Recently, the wide application of upconversion nanoparticles (UCNPs) in the field of bioimaging has raised the requirement of biocompatibility. Current cytocompatibility studies on UCNPs mainly focus on cancer cells; however, their potential effects on normal cells are rarely addressed. Herein, the cellular effects of a trace amount of ligand-free NaYF4:Yb/Er nanocrystals on the differentiation of rat bone mesenchymal stem cells (rBMSCs) were investigated. First, due to their excellent upconversion fluorescent properties, the cellular uptake of ligand-free NaYF4:Yb/Er nanocrystals was confirmed by confocal laser scanning microscopy, and a homogeneous cytoplasmic distribution was imaged. Second, the viability of the rBMSCs cultured with a series of concentrations of nanoparticles (0, 30, 300, and 3000 ng ml-1) was evaluated, and a dose threshold was determined. Third, the effects of ligand-free NaYF4:Yb/Er nanocrystals on the osteogenesis of the rBMSCs were intensively characterized. The alkaline phosphatase activity assay, quantitative real time polymerase chain reaction for related osteogenic genes, and immunofluorescence staining of specific biomarkers and mineral deposits demonstrated that the ligand-free NaYF4:Yb/Er nanocrystals at a proper concentration can enhance osteogenic differentiation. Finally, intracytoplasmic lipid detection showed that the adipogenic differentiation of rBMSCs might be inhibited in the presence of ligand-free NaYF4:Yb/Er nanocrystals. Meanwhile, these results showed that the effects of ligand-free NaYF4:Yb/Er nanocrystals on rBMSCs were concentration-dependent and reciprocal between osteogenic and adipogenic differentiation. This work provides new insights into the exploring the biocompatibility of UCNPs and will benefit the research community engaged in nanotechnology and biomedicine.


Assuntos
Adipogenia/efeitos dos fármacos , Érbio/química , Fluoretos/farmacologia , Células-Tronco Mesenquimais/citologia , Osteogênese/efeitos dos fármacos , Itérbio/química , Ítrio/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Fluoretos/química , Células HeLa , Humanos , Ligantes , Células-Tronco Mesenquimais/efeitos dos fármacos , Microscopia Confocal , Nanopartículas , Ratos , Coloração e Rotulagem , Ítrio/química
7.
Environ Monit Assess ; 191(12): 781, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31786659

RESUMO

Prolonged consumption of fluoride-contaminated water poses health problems like dental and skeletal fluorosis in many parts of the world including India. In regions with acute water scarcity, it demands immediate intervention like de-fluoridation of water before consumption. In the current study, fluoride-resistant bacteria were isolated from fluoride-contaminated groundwater and soil samples collected from Dungarpur district, India, for their potential use in defluoridation. Out of a total of 53 bacterial isolates that were recovered and screened for fluoride resistance, three highly fluoride-resistant isolates DWC1, DWC2 and DWB5, resistant to up to 9200 mg L-1, 7200 mg L-1 and 5200 mg L-1 fluoride respectively, were characterized and identified as Aeromonas sp., Brevibacterium sp. and Paenibacillus sp. respectively. The fluoride removal capacity of isolates DWC1, DWC2, DWB5 and a consortium of all the three isolates was found to be 68.7%, 73.4%, 76.7 % and 70.1% respectively on nutrient broth supplemented with NaF (2000 mg L-1) after 8 days of incubation. Defluoridation conditions for the strain showing the best result (Paenibacillus sp.) were optimized for real fluoride-rich water collected from Ajmer District, India, using the Taguchi design of experiment. A defluoridation of up to 73.3% was observed at 40 °C temperature and pH 8 with inoculum: water ratio of 2:1 after 8 days of incubation. To the best of our knowledge, the defluoridation capacity of Paenibacillus sp. is the highest reported in literature to date for real water samples and could be investigated in further detail for commercial application.


Assuntos
Bactérias , Fluoretos , Água Doce , Purificação da Água , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Farmacorresistência Bacteriana , Fluoretos/análise , Fluoretos/metabolismo , Fluoretos/farmacologia , Água Doce/química , Água Doce/microbiologia , Índia , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo , Poluição da Água , Purificação da Água/métodos
8.
Chem Pharm Bull (Tokyo) ; 67(12): 1278-1283, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31787654

RESUMO

The progesterone receptor (PR) plays an important role in various physiological processes, especially in the female reproductive system, and abnormalities of PR function are associated with several diseases, including some types of cancer. Non-steroidal PR ligands are of interest as candidate drugs for treatment of PR-related diseases without the serious adverse effects that may be caused by steroidal ligands. For the development of non-steroidal PR ligands, both a hydrophobic backbone and a polar functional group corresponding to the 3-carbonyl group of progesterone, which interacts with Gln725 and Arg766 of the PR-ligand binding domain, are critically important. We previously showed that carborane is a useful hydrophobic pharmacophore for PR antagonists, and in this work, we introduced the pentafluorosulfanyl (SF5) group as a novel polar functional group of carborane-based non-steroidal PR antagonists. All the synthesized SF5-containing carborane derivatives exhibited PR-antagonistic activity at micromolar or submicromolar concentration. Among them, compounds 11 are potent progesterone antagonists with submicromolar IC50 values.


Assuntos
Boro/farmacologia , Fluoretos/farmacologia , Receptores de Progesterona/antagonistas & inibidores , Compostos de Enxofre/farmacologia , Boro/química , Fluoretos/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Estrutura Molecular , Relação Estrutura-Atividade , Compostos de Enxofre/química
9.
Sci Rep ; 9(1): 19550, 2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-31863074

RESUMO

We incorporated zwitterionic materials into light-curable fluoride varnish (LCFV) in order to inhibit biofilm accumulation and prevent dental caries, and the properties of LCFV with three different zwitterionic materials, namely, 2-methacryloyloxyethyl phosphorylcholine (MPC), carboxybetaine methacrylate (CBMA), and sulfobetaine methacrylate (SBMA) polymers (each at a weight percentage of 3%), were compared; unmodified LCFV without any zwitterionic material was used as a control. Material properties including film thickness and degree of conversion (DC) of each type of LCFV were evaluated. In addition, protein-repellent effects and inhibitory effects on Streptococcus mutans adhesion and saliva-derived biofilm accumulation of LCFV were estimated. Finally, the preventive effect of LCFV on enamel demineralization was assessed in vitro on extracted human teeth specimens stored in S. mutans-containing medium. The film thickness of LCFV significantly decreased with the incorporation of zwitterionic materials compared to the control LCFV, whereas there were no significant differences in the DC among all of the LCFV groups. Furthermore, the amount of adsorbed protein, adherent S. mutans colony-forming unit (CFU) counts, and saliva-derived biofilm thickness and biomass were all significantly lower for LCFV with incorporated zwitterionic materials compared with the control. All LCFV groups including the control showed certain preventive effects against enamel demineralization during a 14-day immersion in the medium with S. mutans and sucrose, and the depth of demineralization was significantly lower in LCFV with zwitterionic materials than in the control. Thus, the incorporation of zwitterionic materials such as MPC, CBMA, and SBMA appears to confer superior antifouling effects to LCFV.


Assuntos
Cárie Dentária/microbiologia , Fluoretos/química , Fluoretos/farmacologia , Biofilmes/efeitos dos fármacos , Metacrilatos/química , Fosforilcolina/análogos & derivados , Fosforilcolina/química , Streptococcus mutans/efeitos dos fármacos
10.
J Water Health ; 17(6): 845-862, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31850893

RESUMO

The relationship between naturally fluoridated groundwater and dental fluorosis has received large attention from researchers around the world. Despite recognition that several factors influence this relationship, there is a lack of systematic studies analyzing the heterogeneity of these results. To fill such a gap, this study performs a systematic review and meta-analysis to understand which factors influence this relationship and how. Selected studies were sampled between 2007 and 2017 from Web of Science, PubMed, Google Scholar and Scopus using keywords and Boolean operators. Results of the systematic review show that dental fluorosis affects individuals of all ages, with the highest prevalence below 11, while the impact of other factors (gender, environmental conditions, diet and dental caries) was inconclusive. Meta-regression analysis, based on information collected through systematic review, indicates that both fluoride in drinking water and temperature influence dental fluorosis significantly and that these studies might be affected by publication bias. Findings show that fluoride negatively affects people's health in less developed countries. The conclusions discuss policy tools and technological innovations that could reduce fluoride levels below that of the World Health Organization (WHO) (<1.5 mg/L).


Assuntos
Cárie Dentária/prevenção & controle , Água Potável/química , Fluoretos/farmacologia , Fluorose Dentária , Fluoretos/efeitos adversos , Água Subterrânea , Humanos , Prevalência
11.
Niger J Clin Pract ; 22(11): 1546-1552, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31719276

RESUMO

Objectives: The aim of this in vitro study was to evaluate the effects of casein phosphopeptides (CPP)-ACPF, NovaMin+ fluoride-containing toothpaste and Xylitol+ fluoride containing cream on demineralized areas on the enamel surface. Materials and Methods: A total of 100 enamel slab samples was prepared to investigate in the laboratory experiments. For this purpose, a total of 50 freshly extracted third molar teeth which completed root formation split into two portions in the mesiodistal direction. Enamel surfaces were immersed in a pH cycling protocol as described in the literature to simulate oral conditions for 9 days in order to evaluate the effect of test materials on the artificial enamel lesions. Then the remineralization agents were applied on the enamel surfaces, and we analyzed their effects. Results: We used Vickers Microhardness with the purpose of calculating the amount of lost or acquisition of minerals on the enamel surface qualitatively; inductively coupled plasma atomic emission spectroscopy (ICP-AES) to define the calcium and phosphorus ions that dissolved in acid. One-way ANOVA and Tukey's T Post-Hoc tests were performed to distinguish significant differences among groups (P < 0.05). Conclusions: Remineralization was provided in all treated groups, according to the data obtained from all tests. NovaMin was more effective in increasing acid resistance. It was also found that all three experimental groups were effective in increasing the surface hardness, but CPP-ACPF and NovaMin are more effective than Xylitol. However, there was no statistically significant difference between the experimental groups.


Assuntos
Esmalte Dentário/efeitos dos fármacos , Fluoretos Tópicos/uso terapêutico , Fluoretos/uso terapêutico , Vidro , Desmineralização do Dente/tratamento farmacológico , Remineralização Dentária/métodos , Cremes Dentais , Xilitol/uso terapêutico , Cálcio , Caseínas/uso terapêutico , Fluoretos/farmacologia , Dureza , Humanos , Cremes Dentais/farmacologia , Xilitol/administração & dosagem , Xilitol/farmacologia
12.
Mater Sci Eng C Mater Biol Appl ; 104: 109924, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31499991

RESUMO

We report the first experimental evidence for the mitogenic action of cerium(IV) oxide and cerium(III) fluoride nanoparticles (CONs and CFNs) on the regeneration of a whole organism - freshwater flatworms Schmidtea mediterranea (planarian). Both types of cerium-containing nanoparticles are shown to be a highly potent mitogen for planaria. Both CONs and CFNs, in micro- and nanomolar concentrations, markedly accelerate planarian blastema growth, due to the enhancement of cellular proliferation, causing an increase in the mitotic index and in the quantity of blastema cells in regenerating planaria. CONs provided maximum activity at concentrations which were two orders of magnitude lower than those for CeF3. The valence state of cerium in cerium-containing nanoparticles plays a significant role in the planarian regeneration mechanism: CeO2 nanoparticles containing predominantly Ce4+ species presumably scavenge wound induced reactive oxygen species and moderately activate gene expression processes, while the regenerative action of CeF3 nanoparticles containing only Ce3+ species is manifested in the pronounced expression of the genes involved in cell division, differentiation and migration. This is the first report on the effect of cerium-containing nanoparticles on tissue regeneration in vivo, further revealing the mechanisms of their biological action, which enhances the possibility of their use in cellular technologies.


Assuntos
Cério/farmacologia , Fluoretos/farmacologia , Compostos Inorgânicos/farmacologia , Mitógenos/farmacologia , Nanopartículas/química , Planárias/citologia , Planárias/fisiologia , Regeneração/efeitos dos fármacos , Animais , Morte Celular/efeitos dos fármacos , DNA/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Instabilidade Genômica , Cabeça , Mitose/efeitos dos fármacos , Mutagênicos/toxicidade , Planárias/efeitos dos fármacos , Planárias/genética , Testes de Toxicidade
13.
Braz Oral Res ; 33: e037, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31508726

RESUMO

Iontophoresis is a noninvasive technique, based on the application of a constant low-intensity electric current to facilitate the release of a variety of drugs, whether ionized or not, through biological membranes. The objective of this research was to evaluate the effect of iontophoresis using different electric current intensities on the uptake of fluoride in dental enamel with artificial caries lesions. In this in vitro operator-blind experiment, bovine enamel blocks (n = 10/group) with caries-like lesions and predetermined surface hardness were randomized into 6 groups: placebo gel without fluoride applied with a current of 0.8 mA (negative control), 2% NaF gel without application of any current, and 2% NaF gel applied with currents of 0.1, 0.2, 0.4 and 0.8 mA. Cathodic iontophoresis was applied for 4 min. The concentration of loosely bound fluoride (calcium fluoride) and firmly bound fluoride (fluorapatite) was determined. The results were analyzed by the nonparametric Kruskal-Wallis and Dunn tests. Iontophoresis at 0.8 mA, combined with the application of fluoridated gel (2% NaF), increased fluoride uptake in enamel with caries-like lesions, as either calcium fluoride or fluorapatite.


Assuntos
Cariostáticos/farmacologia , Cárie Dentária , Esmalte Dentário/efeitos dos fármacos , Fluoretos/farmacologia , Iontoforese/métodos , Animais , Apatitas/análise , Fluoreto de Cálcio/análise , Bovinos , Modelos Animais de Doenças , Eletricidade , Dureza/efeitos dos fármacos , Distribuição Aleatória , Propriedades de Superfície/efeitos dos fármacos , Resultado do Tratamento
14.
Med Sci Monit ; 25: 6397-6404, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31447481

RESUMO

BACKGROUND This study aimed to assess the awareness of dentists and non-dental doctors regarding the benefits and risks of using fluoridated toothpaste. MATERIAL AND METHODS A self-administered questionnaire was used to collect information in this study. Multistage cluster sampling method was used to enroll doctors in 5 districts or counties in Chongqing, China. A total of 403 doctors (160 dentists and 243 non-dental doctors) completed the questionnaire. RESULTS The awareness of the anti-caries efficacy and the usage of fluoridated toothpaste in dentists was significantly higher than those of non-dental doctors (P<0.001). Most (about 60%) dentists and non-dental doctors had concerns about fluoridated toothpaste. Only 31.3% of dentists and 25.9% of non-dental doctors had a good understanding of the benefits and risks of use of fluoridated toothpaste in children under 3 years of age to 49.4% of dentists and 73.3% of non-dental doctors did not understand the benefits and risks in children 3~6 years old, and 40.0% of dentists and 67.5% of non-dental doctors did not understand the risks and benefits in individuals living in high-fluoride areas. Most dentists (76.3%) and non-dental doctors (87.3%) did not understand the benefits and risks in pregnant women. CONCLUSIONS Dentists and non-dental doctors were concerned about the potential risks of use of fluoridated toothpaste, and they lacked adequate knowledge about the benefits and risks of use of fluoridated toothpaste. Health education is needed to improve doctors' knowledge about use of fluoridated toothpaste.


Assuntos
Atitude do Pessoal de Saúde/etnologia , Fluoretação/efeitos adversos , Adulto , Idoso , Conscientização , China , Cárie Dentária/terapia , Feminino , Fluoretos/efeitos adversos , Fluoretos/farmacologia , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Médicos , Medição de Risco , Inquéritos e Questionários , Cremes Dentais/efeitos adversos , Cremes Dentais/uso terapêutico
15.
Environ Int ; 132: 105012, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31402058

RESUMO

BACKGROUND: Hepato- and nephrotoxicity of fluoride have been demonstrated in animals, but few studies have examined potential effects in humans. This population-based study examines the relationship between chronic low-level fluoride exposure and kidney and liver function among United States (U.S.) adolescents. This study aimed to evaluate whether greater fluoride exposure is associated with altered kidney and liver parameters among U.S. youth. METHODS: This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (2013-2016). We analyzed data from 1983 and 1742 adolescents who had plasma and water fluoride measures respectively and did not have kidney disease. Fluoride was measured in plasma and household tap water. Kidney parameters included estimated glomerular filtration rate (calculated by the original Schwartz formula), serum uric acid, and the urinary albumin to creatinine ratio. Liver parameters were assessed in serum and included alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, blood urea nitrogen, gamma-glutamyl transferase, and albumin. Survey-weighted linear regression examined relationships between fluoride exposure and kidney and liver parameters after covariate adjustment. A Holm-Bonferroni correction accounted for multiple comparisons. RESULTS: The average age of adolescents was 15.4 years. Median water and plasma fluoride concentrations were 0.48 mg/L and 0.33 µmol/L respectively. A 1 µmol/L increase in plasma fluoride was associated with a 10.36 mL/min/1.73 m2 lower estimated glomerular filtration rate (95% CI: -17.50, -3.22; p = 0.05), a 0.29 mg/dL higher serum uric acid concentration (95% CI: 0.09, 0.50; p = 0.05), and a 1.29 mg/dL lower blood urea nitrogen concentration (95%CI: -1.87, -0.70; p < 0.001). A 1 mg/L increase in water fluoride was associated with a 0.93 mg/dL lower blood urea nitrogen concentration (95% CI: -1.44, -0.42; p = 0.007). CONCLUSIONS: Fluoride exposure may contribute to complex changes in kidney and liver related parameters among U.S. adolescents. As the study is cross-sectional, reverse causality cannot be ruled out; therefore, altered kidney and/or liver function may impact bodily fluoride absorption and metabolic processes.


Assuntos
Fluoretos/farmacologia , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Adolescente , Aspartato Aminotransferases/metabolismo , Criança , Pré-Escolar , Estudos Transversais , Feminino , Fluoretos/metabolismo , Taxa de Filtração Glomerular , Humanos , Lactente , Recém-Nascido , Rim/metabolismo , Testes de Função Renal , Modelos Lineares , Fígado/metabolismo , Masculino , Minerais , Inquéritos Nutricionais , Estados Unidos , Ácido Úrico/sangue , Adulto Jovem , gama-Glutamiltransferase/metabolismo
16.
Colloids Surf B Biointerfaces ; 182: 110359, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31352253

RESUMO

Multiple ions codoping may effectively modulate physicochemical and biological properties of hydroxyapatite (HA) for diverse biomedical applications. This study synthesized strontium (Sr)-, fluorine (F)- doped, and Sr/F-codoped HA nanoparticles by a hydrothermal method, and investigated the effect of ion doping on characteristics of HA, including crystallinity, crystal size, lattice parameters, and substitution sites by experiments and simulation with density functional theory (DFT) methods. It was found that, Sr doping increased the lattice parameters of HA whereas F doping decreased these parameters. Additionally, F doping enhanced the structural stability of the Sr-doped HA. F doping created excellent antibacterial properties to effectively inhibit growth of Streptococcus mutans. An appropriate Sr doping level endowed HA with optimum osteogenic ability to promote osteoblastic differentiation of bone marrow stem cells. These suggest that, Sr/F codoping is an effective approach to synthesizing HA-based materials with both antibacterial and osteogenic properties. More broadly, HA nanomaterials with specific characteristics may be designed for meeting diverse requirements from biomedical applications.


Assuntos
Antibacterianos/síntese química , Durapatita/química , Fluoretos/química , Células-Tronco Mesenquimais/efeitos dos fármacos , Nanopartículas/química , Osteoblastos/efeitos dos fármacos , Estrôncio/química , Antibacterianos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Cristalização , Durapatita/farmacologia , Fluoretos/farmacologia , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/fisiologia , Testes de Sensibilidade Microbiana , Estrutura Molecular , Osteoblastos/citologia , Osteoblastos/fisiologia , Osteogênese/efeitos dos fármacos , Teoria Quântica , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/crescimento & desenvolvimento , Estrôncio/farmacologia , Engenharia Tecidual
17.
Int J Radiat Biol ; 95(11): 1581-1587, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31329504

RESUMO

Background: The combined effect of exposure to a static magnetic field (SMF) and potentially toxic agents is a crucial research area, mainly due to occupational and environmental exposure to these factors. The aim of this study was to evaluate the effect of the simultaneous exposure of human fibroblasts to fluoride and a SMF.Materials and methods: Control fibroblasts and fibroblasts that had been treated with fluoride were subjected to an SMF at a moderate induction (0.45, 0.55 and 0.65 T). The intracellular reactive oxygen species production, the concentration of malondialdehyde and the activities of superoxide dismutase and glutathione peroxidase were measured.Results: Our investigations revealed that a moderate SMF does not enhance the action of fluoride in inducing oxidative stress by generating free radicalsConclusions: A moderate SMF may be a factor that weakens the toxic action of fluoride, which is important for the health of individuals that are co-exposed to an SMF and fluoride ions (F-) from occupational and environmental sources.


Assuntos
Fibroblastos/efeitos dos fármacos , Fibroblastos/efeitos da radiação , Fluoretos/farmacologia , Campos Magnéticos , Antioxidantes/metabolismo , Linhagem Celular , Sobrevivência Celular , Exposição Ambiental , Glutationa Peroxidase/metabolismo , Humanos , Peroxidação de Lipídeos , Malondialdeído/metabolismo , Exposição Ocupacional , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo
18.
BMC Oral Health ; 19(1): 121, 2019 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-31217005

RESUMO

BACKGROUND: This study aimed to assess the efficacy of a 980-nm diode and 10.6-µm CO2 laser accompanied by tricalcium phosphate-5% sodium fluoride (fTCP) and casein phosphopeptide amorphous calcium phosphate (CPP-ACP) for the remineralization of primary teeth. METHODS: In total, 117 extracted primary anterior teeth were randomly divided into eight experimental and one control group: (I) control (polished enamel), (II) fTCP varnish, (III) fTCP + diode laser, (IV) fTCP + CO2 laser, (V) CPP-ACP, (VI) CPP-ACP + diode laser, (VII) CPP-ACP + CO2 laser, (VIII) diode laser, and (IX) CO2 laser. The microhardness of 12 samples in each group and the enamel porosity of one sample in each group were assessed before and after demineralization and 28 days after remineralization. Data were analysed using two-way ANOVA. RESULTS: Significant differences existed in microhardness (P = 0.004) and percentage of remineralization (P < 0.001) after remineralization among the material groups such that the highest mean was noted in the CPP-ACP group. No significant difference was noted in microhardness (P = 0.052) or percentage of remineralization (P = 0.981) after remineralization among the laser groups. In all groups, porosities increased after demineralization and slightly decreased after remineralization; the greatest reduction in porosity of the material groups was noted in the fTCP group, and the CO2 group among the laser groups. The interaction effect of materials and lasers was not significant (P > 0.05). CONCLUSION: The highest microhardness was achieved after remineralization with CPP-ACP. The efficacy of the diode and CO2 lasers was the same. No synergistic effect was found between materials and lasers. TRIAL REGISTRATION: This is not a human subject research.


Assuntos
Cariostáticos/farmacologia , Caseínas/farmacologia , Esmalte Dentário/efeitos dos fármacos , Fluoretos/farmacologia , Lasers de Gás , Lasers Semicondutores , Remineralização Dentária/métodos , Dente Decíduo/efeitos dos fármacos , Criança , Pré-Escolar , Feminino , Humanos , Técnicas In Vitro , Masculino , Propriedades de Superfície/efeitos dos fármacos
19.
Chemosphere ; 235: 1-11, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31254776

RESUMO

The first systematic study on high fluoride contaminated fractured rock aquifer in South Africa using geochemical and chemometric approach is presented. Groundwater samples were collected from 49 boreholes and analysed for EC, pH, major and minor ions. The groundwater with high fluoride is associated with NaCl water types. The groundwater chemistry is governed by mineral weathering, evaporation and wastewater infiltration. PHREEQC modelling indicates that carbonate mineral saturation is decreasing with increasing salinity due to evaporation whereas fluorite saturation increases with increasing F being one of the prime controlling factors. Silicate minerals namely chalcedony, quartz and talc express saturation and over-saturation while chrysotile and sepiolite are undersaturated in most of the samples. PCA provided four factors and justified the role of mineral weathering, evaporation, ion exchange, longer residence time and anthropogenic impacts on water chemistry. R-mode and Q-mode cluster analysis resulted in four clusters. In cluster 1, (29%) of groundwater is less mineralized due to recent recharge. In cluster 2 (45%), groundwater chemistry is governed by weathering of silicates and fluorite minerals. Cluster 3 (20%) reveals the impact of anthropogenic activities and induced mineral weathering. Cluster 4 shows high EC, TDS, major ions, F and low HCO3 implying that groundwater is affected by evaporation and longer residence time promoting mineral-water interaction and precipitation of carbonate minerals. More than 50% of the study area is degraded due to fluoride contamination which requires proper remedial actions and further investigations on human health risk due to impact of fluoride contamination in groundwater is recommended.


Assuntos
Monitoramento Ambiental/métodos , Fluoretos/análise , Água Subterrânea/química , Poluentes Químicos da Água/análise , Análise por Conglomerados , Fluoretos/farmacologia , Troca Iônica , Minerais/análise , Análise de Componente Principal , Salinidade , África do Sul , Tempo (Meteorologia)
20.
Chemosphere ; 234: 409-418, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31228844

RESUMO

Intestinal microflora play an important role in maintaining the homeostasis of the intestinal microenvironment, but fluoride-induced changes in intestinal mechanical barrier and intestinal microflora have not been well studied. Given this paucity of information, this study aims to determine the effects of high fluoride level on intestinal mechanical barrier and intestinal microflora in the cecum of mice. Seventy-two female 21-day-old Kunming mice were randomly assigned to three groups and raised for 70 days. Changes in intestinal pathomorphology and intestinal epithelial cell proliferation were observed by haematoxylin and eosin-staining and Brdu measurement, respectively. The distribution of goblet cells, glycoproteins and mast cells was analysed through Alcian blue and periodic acid-Schiff (AB-PAS) staining, Periodic Acid-Schiff (PAS) staining, and toluidine blue staining. Results showed that excessive fluoride damaged the structure of the cecal tissues, inhibited epithelial cell proliferation and decreased the relative distribution of goblet cells, glycoproteins and mast cells that are involved in defense responses. Intestinal microflora sequencing analysis revealed that the composition of the diversity and composition of intestinal microflora was altered by excessive fluoride based on 16S rRNA amplicon sequencing. The relative abundance of Firmicutes (P = 0.03174), Bacteroidetes (P = 0.04462), Actinobacteria (P = 0.01085) and Spirochacteria (P = 0.04084) was significantly changed in the fluoride group as compared with the control group. In conclusion, excessive fluoride intake induced intestinal barrier damage, leading to changes in cecal composition, epithelium secretion and intestinal microflora.


Assuntos
Ceco/efeitos dos fármacos , Epitélio/patologia , Fluoretos/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Intestinos/patologia , Animais , Bactérias/genética , Bactérias/isolamento & purificação , Ceco/microbiologia , Ceco/patologia , Epitélio/efeitos dos fármacos , Feminino , Intestinos/microbiologia , Camundongos , RNA Ribossômico 16S/genética
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